Effect of aneurysm on the mechanical dissection properties of the human ascending thoracic aorta

2012

Objectives: The acute dissection of an ascending thoracic aortic aneurysm (ATAA) represents a devastating separation of elastic layers occurring when the hemodynamic loads on the diseased wall exceed the adhesive strength between layers. At present, the mechanics underlying aortic dissection are largely unclear, and the biomechanical delamination properties of the aneurysmal aorta are not defined. Individuals with bicuspid aortic valve (BAV) are particularly predisposed to ascending aortic aneurysm formation, with a marked risk of aortic dissection. The purpose of this study was to evaluate and compare the dissection properties of nonaneurysmal and aneurysmal human ascending thoracic aorta …

Fiber Micro-Architecture in the Longitudinal-Radial and Circumferential-Radial Planes of Ascending Thoracic Aortic Aneurysm Media.

2013

It was recently demonstrated by our group that the delamination strength of ascending thoracic aortic aneurysms (ATAA) was lower than that of control (CTRL, non-aneurysmal) ascending thoracic aorta (ATA), and the reduced strength was more pronounced among bicuspid (BAV) vs. tricuspid aortic valve (TAV) patients, suggesting a different risk of aortic dissection for BAV patients. We hypothesized that aortic valve morphologic phenotype predicts fiber micro-architectural anomalies in ATA. To test the hypothesis, we characterized the micro-architecture in the longitudinal-radial (Z-RAD) and circumferential-radial (Θ-RAD) planes of human ATA tissue that was artificially dissected medially. The ou…

On the Measurement and Prediction of the Out-of-Plane Displacement Surrounding Cold-Expanded Holes

2010

Experimental measurements of the out-of-plane displacement surrounding cold-expanded holes in a 6082-T6 aluminum alloy were made with a 3D optical scanner using the technique of the encoded light-pattern projection in white light. The measured surface profiles have shown the thickness discontinuity along the hole edge due to the effect of the split in the sleeve. An analytical–numerical solution of the out-of-plane displacement is presented based on existing analytical models. Thus, the results given by the analytical model were then compared with the experimental data and with a finite element (FE) model that simulates the cold-expansion process. The location of the elastic–plastic boundar…

On the prospect of serum exosomal miRNA profiling and protein biomarkers for the diagnosis of ascending aortic dilatation in patients with bicuspid a…

2018

Background: To determine the impact of circulating miRNA and protein activity on the severity of ascending aortic dilatation in patients with bicuspid (BAV) and tricuspid aortic valve (TAV). Methods: By reverse transcription polymerase chain reaction, exosomal circulating expression levels (versus healthy aorta) of miRNAs and absolute levels of transforming growth factor β (TGF-β), matrix metalloproteinases (MMP-2, -3 and -9), tissue inhibitors (TIMP-1, -2, -3 and -4), and soluble receptors for advanced glycation end products AGEs (sRAGE) were evaluated in ascending dilated aortas of 71 patients with different valve morphotype. Results: Less-dilated ascending aorta exhibited a specific miRN…

Predicting LVOT Obstruction in Transcatheter Mitral Valve Replacement for Failed Surgical Annuloplasty

2020

Pine stand density influences the regeneration of Acacia saligna (Labill.) H.L.Wendl. and native woody species in a mediterranean coastal pine planta…

2018

Mediterranean plantations are the most suitable areas to assess vegetation dynamics and competitive interactions between native and exotic woody species. Our research was carried out in a coastal pine plantation (Sicily) where renaturalization by native species (Pistacia lentiscus L. and Olea europaea var. sylvestris) and invasion by Acacia saligna (Labill.) H.L.Wendl. simultaneously occur. The regeneration pattern of woody species in the pine understory was evaluated in six experimental plots along a stand density gradient, from 200 to approximately 700 pines per hectare. Both pine stand density and regeneration by native species had a significant negative relationship with Acacia natural …

Three-dimensional parametric modeling of bicuspid aortopathy and comparison with computational flow predictions

2017

Bicuspid aortic valve (BAV)-associated ascending aneurysmal aortopathy (namely "bicuspid aortopathy") is a heterogeneous disease making surgeon predictions particularly challenging. Computational flow analysis can be used to evaluate the BAV-related hemodynamic disturbances, which likely lead to aneurysm enlargement and progression. However, the anatomic reconstruction process is time consuming so that predicting hemodynamic and structural evolution by computational modeling is unfeasible in routine clinical practice. The aim of the study was to design and develop a parametric program for three-dimensional (3D) representations of aneurysmal aorta and different BAV phenotypes starting from s…

Residual Stresses Induced by Cold Expansion of Adjacent and Cut-Out Holes

2012

Fatigue life of fastener holes can be enhanced via a cold-expansion process to introduce a compressive residual stress field around the hole edge and to reduce crack growth propagation. Considering that aerospace components contain multiple rows of holes, the present investigation focuses on the evaluation of the three-dimensional residual stress distribution in adjacent cold-expanded (CE) holes. The redistribution of residual stresses caused by a cut introduced between two adjacent holes was also investigated. Finite element (FE) analysis and experimental technique were used to assess the residual stress distribution in a 6082-T6 aluminum plate with two adjacent holes expanded sequentially…

Corrigendum to Patterns of ascending aortic dilatation and predictors of surgical replacement of the aorta: A comparison of bicuspid and tricuspid ao…

2020

The authors regret that the author name of Romano and Raffa are incorrect. The corrected author's name are Romano G and Raffa GM. The authors would like to apologise for any inconvenience caused.

Left Ventricle Biomechanics of Low-Flow, Low-Gradient Aortic Stenosis: A Patient-Specific Computational Model

2022

This study aimed to create an imaging-derived patient-specific computational model of low-flow, low-gradient (LFLG) aortic stenosis (AS) to obtain biomechanics data about the left ventricle. LFLG AS is now a commonly recognized sub-type of aortic stenosis. There remains much controversy over its management, and investigation into ventricular biomechanics may elucidate pathophysiology and better identify patients for valve replacement. ECG-gated cardiac computed tomography images from a patient with LFLG AS were obtained to provide patient-specific geometry for the computational model. Surfaces of the left atrium, left ventricle (LV), and outflow track were segmented. A previously validated …

Inversion of Left Atrial Appendage Will Cause Compressive Stresses in the Tissue: Simulation Study of Potential Therapy

2022

In atrial fibrillation (AF), thromboembolic events can result from the particular conformation of the left atrial appendage (LAA) bearing increased clot formation and accumulation. Current therapies to reduce the risk of adverse events rely on surgical exclusion or percutaneous occlusion, each of which has drawbacks limiting application and efficacy. We sought to quantify the hemodynamic and structural loads of a novel potential procedure to partially invert the “dead” LAA space to eliminate the auricle apex where clots develop. A realistic left atrial geometry was first achieved from the heart anatomy of the Living Heart Human Model (LHHM) and then the left atrial appendage inversion (LAAI…

Three-dimensional parametric modeling of bicuspid aortopathy and comparison with computational flow predictions

2016

Bicuspid aortic valve (BAV)-associated ascending aneurysmal aortopathy (namely “bicuspid aortopathy”) is a heterogeneous disease making surgeon predictions particularly challenging. Computational flow analysis can be used to evaluate the BAV-related hemodynamic disturbances, which likely lead to aneurysm enlargement and progression. However, the anatomic reconstruction process is time consuming so that predicting hemodynamic and structural evolution by computational modeling is unfeasible in routine clinical practice. The aim of the study was to design and develop a parametric program for three-dimensional (3D) representations of aneurysmal aorta and different BAV phenotypes starting fr…

The impact of Carpobrotus cfr. acinaciformis (L.) L. Bolus on soil nutrients, microbial communities structure and native plant communities in Mediter…

2016

Background and aims: Carpobrotus spp. are amongst the most impactful and widespread plant invaders of Mediterranean habitats. Despite the negative ecological impacts on soil and vegetation that have been documented, information is still limited about the effect by Carpobrotus on soil microbial communities. We aimed to assess the changes in the floristic, soil and microbial parameters following the invasion by Carpobrotus cfr. acinaciformis within an insular Mediterranean ecosystem. Methods: Within three study areas a paired-site approach, comparing an invaded vs. a non-invaded plot, was established. Within each plot biodiversity indexes, C and N soil content, pH and microbial biomass and st…

Assessing the biomass of shrubs typical of Mediterranean pre-forest communities

2012

One of the most outstanding issues of current environmental research is the need of reliable assessments of carbon stock (i.e. above-ground (a.g.) and below-ground biomass, deadwood, litter, and organic soil matter) within forest ecosystems. Although shrub vegetation plays an important role in accumulating carbon in many Mediterranean environments, there is still very little knowledge on the carbon they store. In this article, we analyze the a.g. carbon stock of several Mediterranean shrubby communities in Sicily (Italy), dominated by Pistacia lentiscus, Chamaerops humilis, Euphorbia dendroides and Spartium junceum. Plant samples for each species were selected, and morphometric attributes (…

Evaluation of Residual Stresses During Fatigue Test in an FSW Joint

2008

At present, friction stir welding (FSW) represents one of the most interesting techniques in the field of welding. The process is has been implemented in industrial practice for joining aluminium alloys, while the welding of the titanium alloy and the steels is still primarily in a developmental stage.

Structural analysis of woody species in Mediterranean old fields.

2008

The first part of this study provides an overview on Sicilian olive systems. Subsequently, the study describes the different typologies of cultivated agroforestry systems present in South-Eastern Sicily employing olive trees in association with other Mediterranean tree species, in particular for the production of firewood, coal and animal food (downy or pubescent oak, holm oak, cork oak), but also in association with forage or grazing species (oat, barley, vetch, etc.) or cereals. The study shows that Sicilian agroforestry systems are much more diversified than it was known so far. In the second part, the study describes the spontaneous colonization processes by plants, observed in abandone…

Residual stresses in friction stir welding: numerical simulation and experimental verification

2008

Patient-Specific Analysis of Ascending Thoracic Aortic Aneurysm with the Living Heart Human Model

2021

In ascending thoracic aortic aneurysms (ATAAs), aneurysm kinematics are driven by ventricular traction occurring every heartbeat, increasing the stress level of dilated aortic wall. Aortic elongation due to heart motion and aortic length are emerging as potential indicators of adverse events in ATAAs

Modelling cardiac mechanics of left ventricular noncompaction

2020

Left ventricular noncompaction (LVNC) can be defined as a cardiomyopathy characterised by a pattern of prominent trabecular structure and deep intertrabecular recesses, that is thought to be caused by an arrest of normal endomyocardial morphogenesis. Using patient-specific computational modelling, we assessed the cardiac mechanics of five patients with LVNC and compared myocardial stress and pump performance to those of healthy controls. Findings shown that patients with LVNC have impaired left ventricular (LV) function, making it possible that the lack of fibre shortening of noncompacted layer can determine poor heart function. Pronounced end-systolic wall stress on left ventricular wall o…

Biomechanical Determinants of Right Ventricular Failure in Pulmonary Hypertension.

2018

Pulmonary hypertension (PH) is a disease characterized by progressive adverse remodeling of the distal pulmonary arteries, resulting in elevated pulmonary vascular resistance and load pressure on the right ventricle (RV), ultimately leading to RV failure. Invasive hemodynamic testing is the gold standard for diagnosing PH and guiding patient therapy. We hypothesized that lumped-parameter and biventricular finite-element (FE) modeling may lead to noninvasive predictions of both PH-related hemodynamic and biomechanical parameters that induce PH. We created patient-specific biventricular FE models that characterize the biomechanical response of the heart and coupled them with a lumped-paramete…

Impact of Aortic Stenosis on Myofiber Stress: Translational Application of Left Ventricle-Aortic Coupling Simulation

2020

The severity of aortic stenosis (AS) has traditionally been graded by measuring hemodynamic parameters of transvalvular pressure gradient, ejection jet velocity, or estimating valve orifice area. Recent research has highlighted limitations of these criteria at effectively grading AS in presence of left ventricle (LV) dysfunction. We hypothesized that simulations coupling the aorta and LV could provide meaningful insight into myocardial biomechanical derangements that accompany AS. A realistic finite element model of the human heart with a coupled lumped-parameter circulatory system was used to simulate AS. Finite element analysis was performed with Abaqus FEA. An anisotropic hyperelastic mo…

Species–area relationship and small-island effect of vascular plant diversity in a young volcanic archipelago

2021

International audience; Aims: Aeolian islands form an active volcanic archipelago. By using updated vascular plant checklists for islands and islets, we tested four hypotheses: (i) Island speciesarea relationship (ISAR) of alien species has lower c-and higher z-values than native species, (ii) islands with active volcanoes have lower species richness than expected for native and alien species, (iii) ISAR of native species shows lower c-and higher z-values than ISARs of Mediterranean land bridge archipelagos and (iv) species richness of smaller islets is independent of area.Location: Aeolian Archipelago, Mediterranean Basin.Taxon: Vascular plants, identified and named according to the Flora …

From Clinical Imaging to Patient-Specific Computational Model: Rapid Adaptation of the Living Heart Human Model to a Case of Aortic Stenosis

2021

Aortic stenosis (AS) is the most common acquired heart valve disease in the developed world. Traditional methods of grading AS have relied on the measurement of aortic valve area and transvalvular pressure gradient. Recent research has highlighted the existence of AS variants that do not meet classic criteria for severe AS such as low-flow, low-gradient AS. With the development of sophisticated multi-scale computational models, investigation into the left ventricular (LV) biomechanics of AS offers new insights into the pathophysiology that may guide treatment decisions surrounding AS. Building upon our prior study entailing LV-aortic coupling where AS conditions were applied to the idealize…

The role of traditional Erica arborea L. management practices in maintaining northeastern Sicily’s cultural landscape

2007

The tree heath (Erica arborea L.), a small evergreen tree found in the Mediterranean region and parts of Eastern and Central Africa, produces lignotubers that are highly valued for making smoking pipes. The Peloritani Mountains of northeastern Sicily are historically one of the most important areas in Italy for the production of these high quality lignotubers, known as briar root wood. In the past, tree heath shrublands were also an important source of charcoal. Erica arborea utilisation has declined dramatically during the past century, mostly due to the decreasing demand for smoking pipes, as well as the increasing frequency of wildfires and large-scale afforestation activities in this re…

On the Finite Element Modeling of the Lumbar Spine: A Schematic Review

2023

Finite element modelling of the lumbar spine is a challenging problem. Lower back pain is among the most common pathologies in the global populations, owing to which the patient may need to undergo surgery. The latter may differ in nature and complexity because of spinal disease and patient contraindications (i.e., aging). Today, the understanding of spinal column biomechanics may lead to better comprehension of the disease progression as well as to the development of innovative therapeutic strategies. Better insight into the spine’s biomechanics would certainly guarantee an evolution of current device-based treatments. In this setting, the computational approach appears to be a remarkable …

Impact of pericardial effusion on cardiac mechanics in patients with dilated cardiomyopathy

2013

Dilated cardiomyopathy (CDM) is a degenerative disease of the myocardium accompanied by left ventricular (LV) remodeling, resulting in an impaired pump performance. Differently, pericardial effusion(PE) is a liquid accumulation in the pericardial cavity, which may inhibit blood filling of heart chambers. Clinical evidence show that PE may improve pump performance in patients with CDM. Therefore, this study aims to assess wall stress and global function of patients with CDM, PE as compared to healthy patient. These findings suggests that CDM has an important implication in the mechanical changes of LV and right ventricle by increasing wall stress and reducing pump function. Conversely, PE de…

Plant hunting: exploring the behaviour of amateur botanists in the field

2021

We asked what are the behavioural and logistic preferences of professional and amateur botanists when exploring flora in the field. We extracted temporal and spatial data on vas- cular plant species occurrences from three datasets of Sicilian flora: a subset of iNaturalist, a dataset collected by a Facebook group focused on the flora of Sicily and a subset of the professional database European Vegetation Archive. We used the time span of individual contributor’s activity as a proxy of their commitment to collecting information about the flora of Sicily. Climate and landscape data were used to better characterize the spatial and temporal activity of data contributors. Finally, we assessed wh…

Fatigue life of AA2024-T4 friction stir welded joints influence of process parameters and post-welding treatments

2006

Plantes vasculaires nouvelles ou rares pour la Tunisie présentes sur les îles (Galite, Zembra, Kuriat, Monastir, Kerkennah, Kneiss, Djerba)

2020

International audience; Vascular plants new or rare for Tunisia occurring on the islands (Galite, Zembra, Kuriat, Monastir, Kerkennah, Kneiss, Djerba).-This study concerns the indigenous vascular plants newly reported for Tunisia and discovered on the islands during some field trips performed since 2014. Five native taxa are new to Tunisia: Bellis perennis, Carthamus creticus, Moraea mediterranea, Asplenium balearicum and Galium minutulum, the latter two also being new to North Africa. Information on 24 rare or poorly known taxa, most often of great biogeographical interest, is given, too. Most of these were discovered on the islands of the eastern coast (Kuriat, Monastir, Kerkennah, Kneiss…

The cork oak in the Mountains of Palermo (Italy): ecological insights from the south-eastern edge of its distribution range

2020

Abstract: The uneven presence of the cork oak (Quercus suber L.) within its distribution range is not only determined by its climatic requirements but also by specific edaphic needs. Although most of the natural populations thrive in acidic soils deriving from metamorphic or volcanic rock outcrops, some cork oak populations are found growing in soils deriving from calcareous bedrock, which are considered less suitable. We carried out a multidisciplinary investigation at the south eastern edge of the Q. suber distribution range (Mountains of Palermo, NW Sicily), including soil, floristic, and vegetation surveys, aimed at: (i) assessing the native or introduced origin of some peculiar cork oa…

Previsione numerica delle tensioni residue indotte in fori espansi a freddo

2006

Dissection and 3D reconstruction of healthy and aneurysmal human ascending thoracic aorta

2010

Ascending thoracic aortic aneurysm (ATAA) is among the most devastating forms of cardiovascular disease, causing a significant mortality despite current medical and surgical treatments [1]. This form of disease is a predisposing factor for spontaneous aortic dissection which in general results in the initiation of an intimal flap and its propagation due to blood flow. Since aortic dissection fails by separation of the elastic layers [2], the delamination strength of ATAA tissues was investigated by designing and performing mechanical tests that simulate the in-vivo tearing condition of the aortic wall. Specifically, the delamination tests were carried out on nonaneurysmal and aneurysmal hum…

In Vivo Strain Analysis of Dilated Ascending Thoracic Aorta by ECG-Gated CT Angiographic Imaging

2017

Accurate assessment of aortic extensibility is a requisite first step for elucidating the pathophysiology of an ascending thoracic aortic aneurysm (ATAA). This study aimed to develop a framework for the in vivo evaluation of the full-field distribution of the aortic wall strain by imaging analysis of electrocardiographic- (ECG) gated thoracic data of 34 patients with ATAA. Seven healthy controls (i.e., non-aneurysmal aorta) from patients who underwent ECG-gated CT angiography for coronary artery diseases were included for comparison. To evaluate the systolic function, ECG-gated computed tomography (CT) angiography was used to generate patient-specific geometric meshes of the ascending aorta…

Carbon storage of Mediterranean grasslands

2016

Secondary grasslands are one of the most common vegetation types worldwide. In Europe, and in the Mediterranean basin, human activities have transformed many woodlands into secondary grasslands. Despite their recognized role in the global carbon cycle, very few data are available for estimating the biomass of Mediterranean grasslands. We developed linear regression models in order to predict the biomass of two native Mediterranean grasses (Ampelodesmos mauritanicus and Hyparrhenia hirta) and an invasive alien grass (Pennisetum setaceum). Ampelodesmos mauritanicus is very common throughout the Mediterranean basin, mostly on north-facing slopes, H. hirta characterizes thermo-xeric grasslands,…

The ongoing naturalisation of Eucalyptus spp. in the Mediterranean Basin: new threats to native species and habitats

2019

The genus Eucalyptus has been widely introduced into many regions of the world outside its native range and has become invasive in some Mediterranean biomes (e.g. in southern Africa and California). In the Mediterranean Basin and Europe, eucalypts were introduced at the end of the 18th century. However, natural regeneration events in these regions are recent in time and limited in terms of affected areas, except for the Iberian Peninsula. An updated overview about the natural spread of Eucalyptus species in Italy is still lacking. This paper aims to fill this knowledge gap, using both published data and unpublished field data regarding naturalisation events, with a specific focus on Sicily.…

A new association of relict maquis with Ptilostemon greuteri (Oleo-Ceratonion, Quercetea ilicis), located in a circumscribed area of north-western Si…

2022

This paper illustrates the results of a survey aimed at deepening available knowledge on the ecology of Ptilostemon greuteri (Asteraceae), a very rare palaeoendemic and relict nano-phanerophyte discovered about 15 years ago on Monte Inici, near Castellammare del Golfo (province of Trapani, north-western Sicily). Two plant communities characterised by P. greuteri are described in detail; they occur in the locus classicus and in a second, recently discovered stand, which is also very localised and threatened by fire. The field investigations revealed that the sites where the species grows are very similar from the ecological point of view; in fact, both of them are located on the steep slopes…

<i>Acacia cyclops</i> A. Cunn. ex G. Don (Leguminosae) in Italy: first cases of naturalization

2012

The first two cases of naturalization of <i>Acacia cyclops</i> are reported for Italy. Young trees were observed growing in the wild some 15 years ago on Linosa (Pelagie Islands, Strait of Sicily). A decade later, this alien plant should no longer be considered as a casual, since a very intensive process of self-sown regeneration has been observed in some plantations on Lampedusa, the major island of the same Archipelago. The available literature suggests the need for careful monitoring of the ongoing invasion process, as <i>A. cyclops</i> has already shown a very invasive behaviour elsewhere within Mediterranean-type biomes due to its ability to withstand high envir…

Statistical shape analysis of ascending thoracic aortic aneurysm: Correlation between shape and biomechanical descriptors

2020

An ascending thoracic aortic aneurysm (ATAA) is a heterogeneous disease showing different patterns of aortic dilatation and valve morphologies, each with distinct clinical course. This study aimed to explore the aortic morphology and the associations between shape and function in a population of ATAA, while further assessing novel risk models of aortic surgery not based on aortic size. Shape variability of n = 106 patients with ATAA and different valve morphologies (i.e., bicuspid versus tricuspid aortic valve) was estimated by statistical shape analysis (SSA) to compute a mean aortic shape and its deformation. Once the computational atlas was built, principal component analysis (PCA) allow…

Echocardiography to estimate high filling pressure in patients with heart failure and reduced ejection fraction

2020

Aims: Echocardiographic assessment of left ventricular filling pressures is performed using a multi-parametric algorithm. Unselected sample of patients with heart failure with reduced ejection fraction (HFrEF) patients may demonstrate an indeterminate status of diastolic indices making interpretation challenging. We sought to test improvement in the diagnostic accuracy of standard and strain echocardiography of the left ventricle and left atrium (LA) to estimate a pulmonary capillary wedge pressure (PCWP) > 15 mmHg in patients with HFrEF. Methods and results: Out of 82 consecutive patients, 78 patients were included in the final analysis and right heat catheterization, and echocardiogram…

From common and used to rare and forgotten: Past and present distribution of the archaeophyte Euphorbia lathyris L. (Euphorbiaceae) in southern Italy…

2019

Our study aimed at clarifying the current and previous occurrence, distribution and status (native vs. introduced) of Euphorbia lathyris L., the caper spurge, in S Italy and Sicily: most of the recent Italian floras and checklists, in fact, do not report this species for this area. To do this, a multi-disciplinary research was carried out taking into account not only botanical but also ethnobotanical and dialectological sources and a survey of the main herbaria of central and southern Italy. Our results point out that E. lathyris was much more frequent, well-known and commonly used in the whole southern Italy and in Sicily until 2-3 centuries ago, and that it probably experienced isolated c…

Steam sterilization processes affect the stability of clinical thermometers: Thermistor and prototypal FBG probe comparison

2020

Abstract Temperature is one of the most frequently measured physical quantities in clinical environment and a good biomarker of illness. The need for reusable probes, which have to be sterilized to prevent infections, requires the metrological qualification of thermometer probes in response to ageing effects induced by several sterilization processes. In this study, we investigated the effect of repeated sterilizations on both a commonly-used autoclavable thermistor probe and a prototypal Fiber Bragg Gratings (FBG) probe for temperature measurements. Findings highlighted a greater reliability of the proposed FBG probe than the commercial thermistor. Specifically, the FBG probe was able to w…

On the severity of aortic stenosis in ascending aortic aneurysm: A computational tool to examine ventricular-arterial interaction and aortic wall str…

2020

Abstract An ascending thoracic aortic aneurysm (ATAA) is a life-threatening cardiovascular consequence of vessel dilatation that portends adverse events and death. From a clinical perspective, ATAA should not be treated as an isolated disease, and surgery is often carried out in the presence of AS, aortic insufficiency or a calcified valve leaflet. Aortic stenosis (AS) is common in ATAAs and leads to both vessel rigidity and left ventricular (LV) impairment. In this study, lumped-parameter modeling and computational analysis were used to assess the change in the wall shear stress (WSS) and intramural wall stress of patient-specific ATAA models with different degrees of AS (i.e., mild to sev…

Modeling in cardiovascular biomechanics

2010

In this review, we briefly summarize some of Professor K.R. Rajagopal's contributions to the field of cardiovascular mechanics and highlight some applications that have employed his theories and have expanded the ability to model the complex behaviors that characterize biological tissues. His contributions, spawning directly from the classical nonlinear theories of mechanics, have had general impact in diverse fields of engineering. Within biomechanics per se, Rajagopal's efforts have provided state-of-the-art modeling tools not only to characterize tissues, such as blood vessels, cerebral aneurysms, or blood, but also to characterize their evolution, i.e. vessel growth and remodeling or bl…

The agricultural heritage of Lampedusa (Pelagie Archipelago, South Italy) and its key role for cultivar and wildlife conservation

2011

As occurred on many other little Mediterranean islands, agricultural activity at Lampedusa (Strait of Sicily) underwent a very strong decline in terms of surface area during the second half of the last century. In particular, cereal crops have ceased and horticulture is disappearing, while vineyards still occupy a reduced area but are quickly vanishing and currently survive thanks to a small number of old farmers. Here are presented the results of a research carried out by interviewing seven farmers in order to study not only the techniques and the germplasm used in local viticulture, but also the final use of grapes and an evaluation on the connection between traditional farming and agro-e…

Ascending Aorta Resection and End-to-End Anastomosis: Redistribution of Wall Shear Stress Induced by a Bioprosthetic Heart Valve

2020

Although aortic resection and end-to-end anastomosis are applied to repair ascending aortic aneurysm, there is a lack of information on the late risk of post-operative complications, such as aortic dissection and aneurysmal re-dilatation. It is recognized that altered hemodynamic forces exerted on an aortic wall play an important role on dissection and aneurysm formation. We present a case in which the hemodynamic forces were investigated prior and after repair of an ascending aorta treated by resection with end-to-end anastomosis and a bioprosthetic heart valve. Post-operative wall shear stress was redistributed uniformly along the vessel circumference, and this may suggest a reduced risk …

Fitting the Stocking Rate with Pastoral Resources to Manage and Preserve Mediterranean Forestlands: A Case Study

2015

Pasture practices have affected Mediterranean forest ecosystems for millennia, and they are still quite widespread in mountainous areas. Nevertheless, in the last decades, the stability of forest ecosystems has been jeopardized due to the abandonment of traditional agro-pastoral practices, so that the gradual reduction of open areas due to progressive succession processes has caused a high increase of grazing pressure by livestock and wild ungulates feeding on forest areas. This paper aims at showing a methodological approach for evaluating the effect of applying measures in order to improve the grazing value of grasslands and ecotonal patches and lower the grazing impact on native woodland…

Comparison of hemodynamic and structural indices of ascending thoracic aortic aneurysm as predicted by 2-way FSI, CFD rigid wall simulation and patie…

2018

Patient-specific computational modeling is increasingly being used to predict structural and hemodynamic parameters, especially when current clinical tools are not accessible. Indeed, pathophysiology of ascending thoracic aortic aneurysm (ATAA) has been simulated to quantify the risk of complications by novel prognostic parameters and thus to improve the clinical decision-making process related to the intervention of ATAAs. In this study, the relevance of aneurysmal wall elasticity in determining parameters of clinical importance, such as the wall shear stress (WSS), is discussed together with the significance of applying realistic boundary conditions to consider the aortic stretch and twis…

The alien vascular flora of Linosa (Pelagie Islands, Strait of Sicily): update and management proposals

2017

This paper provides an up-to-date overview of the naturalized alien plants of Linosa (Pelagie Archipelago, Sicily), which includes 83 taxa and accounts for 29 % of the total island's flora. Among these plants, 6 are invasive, 49 are naturalized and 28 are casual. With respect to previous available data, our field investigations resulted in the addition of 31 new xenophytes (21 casual and 10 fully naturalized). One of these species is new to the whole European territory (Kleinia anteuphorbia), 6 of them are new to Sicily and 11 are recorded for the first time on circum-Sicilian islets. For each alien plant, we indicate the habitat where the naturalization has been observed by using the codes…

Habitat type and island identity as drivers of community assembly in an archipelago

2020

Aim: Ecoinformatics offer new opportunity to test islands as biogeographic and eco- logical models. In this paper we predicted three hypotheses: (1) plot-based data issu- ing from vegetation surveys can be used to predict Island Species-Area Relationships (ISARs) or island similarity; (2) the habitat area is an independent predictor of species richness patterns within island; (3) species richness and composition are more de- pendent on habitat type than island identity in land-bridge islands. Area: Tuscan Archipelago, Italy. Methods: We assembled a database of all the vegetation plots available for the archi- pelago. For the first hypothesis we calculated ISARs, using Arrhenius model, and B…

Computational analysis to predict false-lumen perfusion and outcome of type B aortic dissection.

2014

We have attempted to identify potential predictors foracute and late aortic events starting from admission computed tomographic images.

Staying alive on an active volcano: 80 years population dynamics of Cytisus aeolicus (Fabaceae) from Stromboli (Aeolian Islands, Italy)

2020

Abstract Cytisus aeolicus is a narrow endemic species restricted to the Aeolian archipelago (SE Tyrrhenian Sea, Italy) and it is one of the most evolutionarily isolated plants in the Mediterranean flora. Historical and literature data suggest that both metapopulations and isolated individuals of C. aeolicus are gradually shrinking. Field investigations and drone images demonstrate that the C. aeolicus metapopulation from Stromboli experienced a strikingly fast increase during the last decades. As of 2019, more than 7000 ± 3000 mature individuals occur on Stromboli, i.e. 14 to 20 times more than those counted during the last census, 25 years ago. The diachronic analysis of aerial photos conc…

Simulation of left ventricular outflow tract (LVOT) obstruction in transcatheter mitral valve-in-ring replacement.

2020

Left ventricular outflow tract (LVOT) obstruction is a feared complication of transcatheter mitral valve replacement (TMVR). This procedure leads to an elongation of LVOT in the left ventricle (namely, the neoLVOT), ultimately portending hemodynamic impairment and death. This study sought to understand the biomechanical implications of LVOT obstruction in two patients who underwent TMVR as an "off-label" application of the Edwards SAPIEN 3 (S3) Ultra transcatheter heart valve (THV). A computational framework of TMVR was developed to assess the neoLVOT area and quantify the sub-aortic flow structure. We observed that the annuloplasty ring serves as the key anchor zone of S3 Ultra THV. A good…

Checklist of gypsophilous vascular flora in Italy

2018

Our understanding of the richness and uniqueness of the flora growing on gypsum substrates in Italy has grown significantly since the 19th century and, even today, new plant species are still being discovered. However, the plants and plant communities, growing on gypsum substrates in Italy, are still a relatively unknown subject. The main aim of this paper was to elaborate a checklist of the Italian gypsophilous flora, to increase knowledge about this peculiar flora and for which conservation efforts need to be addressed. Through a structured group communication process of experts (application of the Delphi technique), a remarkable number of experienced Italian botanists have joined togethe…

Reviving extinct Mediterranean forest communities may improve ecosystem potential in a warmer future

2015

The Mediterranean Basin is the region of Europe most vulnerable to negative climate-change impacts, including forest decline, increased wildfire, and biodiversity loss. Because humans have affected Mediterranean ecosystems for millennia, it is unclear whether the region's native ecosystems were more resilient to climate change than current ecosystems, and whether they would provide sustainable management options if restored. We simulated vegetation with the LandClim model, using present-day climate as well as future climate-change scenarios, in three representative areas that encompass a broad range of Mediterranean conditions and vegetation types. Sedimentary pollen records that document n…

MIsura del campo di spostamenti di un foro espanso a freddo mediante tecniche DSPI e DIC

2007

Last tesserae of a fading mosaic: floristic census and forest vegetation survey at Parche di Bilello (south-western Sicily, Italy), a site needing ur…

2021

This paper illustrates the botanic heritage of Parche di Bilello, a site located in the municipality of Castelvetrano. The study area hosts several woodland fragments dominated by Olea europaea var. sylvestris, Quercus suber and Quercus ilex, respectively. According to historical data, these nuclei represent the last remnants of an open forestland which covered a much wider coastal area between Mazara del Vallo and Sciacca until the end of Middle Age. Phytosociological relevés were focused on these forest nuclei, probably the most representative of south-western Sicily, which correspond to three habitats included in the 92/43 EEC Directive (9320, 9330 and 9340, respectively) and represent t…

On the Modeling of Transcatheter Therapies for the Aortic and Mitral Valves: A Review

2022

Transcatheter aortic valve replacement (TAVR) has become a milestone for the management of aortic stenosis in a growing number of patients who are unfavorable candidates for surgery. With the new generation of transcatheter heart valves (THV), the feasibility of transcatheter mitral valve replacement (TMVR) for degenerated mitral bioprostheses and failed annuloplasty rings has been demonstrated. In this setting, computational simulations are modernizing the preoperative planning of transcatheter heart valve interventions by predicting the outcome of the bioprosthesis interaction with the human host in a patient-specific fashion. However, computational modeling needs to carry out increasingl…

Atlas-Based Evaluation of Hemodynamic in Ascending Thoracic Aortic Aneurysms

2021

Atlas-based analyses of patients with cardiovascular diseases have recently been explored to understand the mechanistic link between shape and pathophysiology. The construction of probabilistic atlases is based on statistical shape modeling (SSM) to assess key anatomic features for a given patient population. Such an approach is relevant to study the complex nature of the ascending thoracic aortic aneurysm (ATAA) as characterized by different patterns of aortic shapes and valve phenotypes. This study was carried out to develop an SSM of the dilated aorta with both bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV), and then assess the computational hemodynamic of virtual models ob…

Hereditariness of Aortic Tissue: In-Vitro Time-Dependent Failure of Human and Porcine Specimens

2018

This study aims to investigate the time dependent failure of aortic tissues for pathological and healthy samples by biomechanical testing. The experimental campaign has involved human pathological tissue and healthy swine tissue as preliminary study towards the development of novel failure criteria.

AA6082-T6 Friction Stir Welded Joints Fatigue Resistance: Influence of Process Parameters

2006

In the paper the results of a wide range of experiments on friction stir welding (FSW) of aluminium alloys are reported. In particular, the AA6082-T6 butt joints fatigue resistance was investigated by varying the most relevant process parameters. In addition, a revolutionary pitch was utilized in order to investigate the effects of the tool rotating speed and the tool feed rate. Observations of the fracture insurgence were developed for different levels of applied load.

Afforestation and reforestation: the Sicilian case study

2014

In some regions of the world such as the Northern Hemisphere, the abandonment of agricultural land is one of the most widespread forms of land use change. In general, abandonment is followed by colonization by herbaceous and woody plants. Since the 1950s, wide areas of Southern Italy have been afforested for soil conservation improvement. In order to quantify the effects of agricultural abandonment and artificial afforestation on soil organic carbon (SOC), a dataset of 48 Sicilian sites has been analyzed. Because of their high environmental variability, these sites can be considered as representative of Southern Italy and in general of the Mediterranean basin. Soil samples were taken throug…

Studio numerico di sistemi di cementazione per inlay in composito.

2009

Nel lavoro è condotto uno studio numerico su diverse tipologie di cementazione per inlay in composito utilizzate in ambito odontoiatrico per il restauro dei denti anteriori e posteriori. Il comportamento meccanico dei diversi sistemi di cementazione è stato riprodotto numericamente mediante simulazioni FEM: infatti, la moderna tecnica odontoiatrica fa uso dei software agli elementi finiti per l’elevata versatilità ed economicità nello studio di soluzioni sempre diverse. Le simulazioni hanno permesso di prevedere lo stato tensionale e l’evoluzione di una delaminazione creata all’interfaccia bi-materiale.

Holocene environmental and climatic changes at Gorgo Basso, a coastal lake in southern Sicily, Italy

2009

Abstract We used a new sedimentary record to reconstruct the Holocene vegetation and fire history of Gorgo Basso, a coastal lake in south-western Sicily (Italy). Pollen and charcoal data suggest a fire-prone open grassland near the site until ca 10,000 cal yr BP (8050 cal BC), when Pistacia shrubland expanded and fire activity declined, probably in response to increased moisture availability. Evergreen Olea europaea woods expanded ca 8400 to decline abruptly at 8200 cal yr BP, when climatic conditions became drier at other sites in the Mediterranean region. Around 7000 cal yr BP evergreen broadleaved forests ( Quercus ilex , Quercus suber and O. europaea ) expanded at the cost of open commu…

A Population-Based 3D Atlas of the Pathological Lumbar Spine Segment

2022

The spine is the load-bearing structure of human beings and may present several disorders, with low back pain the most frequent problem during human life. Signs of a spine disorder or disease vary depending on the location and type of the spine condition. Therefore, we aim to develop a probabilistic atlas of the lumbar spine segment using statistical shape modeling (SSM) and then explore the variability of spine geometry using principal component analysis (PCA). Using computed tomography (CT), the human spine was reconstructed for 24 patients with spine disorders and then the mean shape was deformed upon specific boundaries (e.g., by ±3 or ±1.5 standard deviation). Results dem…

Nicodemia madagascariensis(Lam.) R. Parker (Family Scrophulariaceae), a casual alien plant new to Italy

2016

In this note the authors report the first case of naturalization of the Malagasy smoke bush within Italian territory. Along with a description of the abiotic and biotic characteristics of the invaded site, the current demographic and dynamic trends of the detected population by means of growth-ring analysis was also assessed. Moreover, an overview on the history of its introduction in Europe is provided, underlining the key role played by the Mediterranean cities with respect to the acclimatization and spread of alien tropical and subtropical plants. Due to its low frequency under cultivation, the Malagasy smoke bush should not behave as an invader in the future; on the other hand, its abil…

Conservation of Ptilostemon greuteri (Asteraceae), an endemic climate relict from Sicily (Italy): state of knowledge after the discovery of a second …

2022

Ptilostemon greuteri is one of the most endangered and poorly studied woody vascular plant species of the Mediterranean Basin, endemic to Sicily (Italy). Several peculiar traits confer to P. greuteri a character of uniqueness and an enigmatic attractiveness. In fact, at first glimpse the largest individuals of this species remind the most remarkable and peculiar cases of herbaceous genera (e.g., Echium, Senecio) turned woody on insular or insular-like mountain ecosystems. Following the discovery of a second population of this rare species, a project aiming at the study and conservation of P. greuteri was set up. We present here updated information on the distribution, conservation status, b…

Fractional Calculus as a New Perspective in the Viscoelastic Behaviour of the Intervertebral Disc

2022

The spinal column is the load-bearing structure of the human being along with its components, which together build a strong, resistant, and stable structure, but there are a few different pathologies from which it can suffer, such as herniated discs. The intervertebral disc acts as a shock absorber and ensures the spine’s great capacity to support high loads and different states of stress, thanks to its viscoelastic properties. Some studies have attempted to describe the viscoelastic behaviour of the intervertebral disc using classical rheological models, such as the Kelvin-Voigt, or multi-parameter models. Even if these models partially describe the viscoelastic response of disc, all visco…

Regional variation of wall shear stress in ascending thoracic aortic aneurysms.

2014

The development of an ascending thoracic aortic aneurysm is likely caused by excessive hemodynamic loads exerted on the aneurysmal wall. Computational fluid-dynamic analyses were performed on patient-specific ascending thoracic aortic aneurysms obtained from patients with either bicuspid aortic valve or tricuspid aortic valve to evaluate hemodynamic and wall shear parameters, imparting aneurysm enlargement. Results showed an accelerated flow along the outer aortic wall with helical flow in the aneurysm center for bicuspid aortic valve ascending thoracic aortic aneurysms. In a different way, tricuspid aortic valve ascending thoracic aortic aneurysms exhibited normal systolic flow without su…

Evaluation of ventricular wall stress and cardiac function in patients with dilated cardiomyopathy

2015

Dilated cardiomyopathy is a heart disease characterized by both left ventricular dilatation and left ventricular systolic dysfunction, leading to cardiac remodeling and ultimately heart failure. We aimed to investigate the effect of dilated cardiomyopathy on the pump performance and myocardial wall mechanics using patient-specific finite element analysis. Results evinced pronounced end-systolic wall stress on left ventricular wall of patients with dilated cardiomyopathy as compared to that of normal hearts. In dilated cardiomyopathy, both end-diastolic and end-systolic pressure–volume relationships of left ventricle and right ventricle were shifted to the right compared to controls, sugges…

Past and current distribution of Charaxes jasius jasius (Linnaeus, 1767) (Lepidoptera Nymphalidae) in Sicily in relation to its host plant, Arbutus u…

2022

The authors provide an updated overview of the past and present regional distribution of the two-tailed Pasha Charaxes jasius jasius (Linnaeus, 1767) (Lepidoptera Nymphalidae) and its host plant, the strawberry tree Arbutus unedo L. Most of the occurrence data reported in the entomological literature was confirmed, and several new populations have been recently dis- covered. The distribution pattern of the insect and its host plant overlap almost perfectly. C. jasius jasius is more abundant and forms large and stable populations on the Peloritani Mts. and in some areas of the Madonie Mountains. The high number of new records of C. jasius jasius suggests that the species is experiencing a sp…

Trying to link vegetation units with biomass data: the case study of Italian shrublands

2014

Although their carbon stock is relevant in assessing the baseline for the negotiation of future agreements with respect to carbon balance, there still are few available studies concerning the biomass and the net ecosystem exchange capacity of Mediterranean shrublands. In this chapter a preliminary overview on the biomass values concerning Italian shrubland communities and/or their dominant/ characteristic woody species is provided. Many useful data on above- and belowground biomass issued from investigations carried out in other Mediterranean countries and concerning plant communities, which share the same ecological, floristic and structural traits of Italian shrublands. A preliminary find…

A novel multi-wavelength procedure for blood pressure estimation using opto-physiological sensor at peripheral arteries and capillaries

2018

© 2018 SPIE. In this study, the Carelight multi-wavelength opto-electronic patch sensor (OEPS) was adopted to assess the effectiveness of a new approach for estimating the systolic blood pressure (SBP) through the changes in the morphology of the OEPS signal. Specifically, the SBP was estimated by changing the pressure exerted on an inflatable cuff placed around the left upper arm. Pressure acquisitions were performed both with gold standard (i.e. electronic sphygmomanometer), and Carelight sensor (experimental procedure), on subjects from a multiethnic cohort (aged 28 ± 7). The OEPS sensor was applied together with a manual inflatable cuff, going slightly above the level of the SBP with in…

Residual stresses in friction stir welded parts of complex geometry

2011

Residual stresses play a key role on the mechanics underlying the fatigue crack growth propagation of welded joints. Indeed, compressive residual stresses may induce a beneficial enhancement of the fatigue life under loading condition whereas tensile residual stresses may act to increase the stress distribution at crack tip, resulting in a life-threatening condition of the welded structure. In-process distortion and final geometry of welded joints are also affected by residual stresses. In this paper, the longitudinal residual stress distributions in friction stir welding (FSW) joints were investigated for butt and skin–stringer geometries, including lap and T configurations. To measure res…

Typification of the name Senecio pygmaeus (Asteraceae), with some additional taxonomic and phytogeographic remarks

2023

A thorough research on the scientific activity of Guglielmo Gasparrini, Giovanni Gussone and Augustin Pyramus De Candolle allowed the authors to adress a research in several European herbaria looking for the type of the name Senecio pygmaeus DC. The original specimen sent by Gussone and mentioned in the protologue by Candolle is still kept at G-DC and is designated as the lectotype, whilst three other herbarium sheets, preserved at NAP-GUSS, PAL and PAV herbaria respectively, in all probability belong to the same gathering, and are considered as isolectotypes. The authors provide an updated description of this taxon in order to better point out its diagnostic characters. However, further bi…

Residual Stress Effects on Fatigue Crack Growth in Ti-6-4 Friction Stir Welds

2006

More nature in the city

2020

According to projects and practices that the Italian botanists and ecologists are carrying out for bringing “more nature in the city”, new insights for a factual integration between ecological perspectives and more consolidated aesthetic and agronomic approaches to the sustainable planning and management of urban green areas are provided.

From glacial refugia to hydrological microrefugia: Factors and processes driving the persistence of the climate relict tree Zelkova sicula

2021

Abstract With only two tiny populations, the climate relict Zelkova sicula (Sicily, Italy) is one of the rarest trees in the world. It also represents the most marginal member of genus Zelkova that was widespread in the broadleaved forests thriving in warm–temperate climates throughout Eurasia until the Last Glacial Age. Occurring at the westernmost range of the genus under typical Mediterranean climate, the micro‐topographic settings have always appeared crucial for the survival of this relict. However, the factors and processes actually involved in its persistence in the current refugia, as well as the response of similar relict trees in arid environments, are poorly understood worldwide.…

Patterns of ascending aortic dilatation and predictors of surgical replacement of the aorta: A comparison of bicuspid and tricuspid aortic valve pati…

2019

Abstract Background Predictors of thoracic aorta growth and early cardiac surgery in patients with bicuspid aortic valve are undefined. Our aim was to identify predictors of ascending aorta dilatation and cardiac surgery in patients with bicuspid aortic valve (BAV). Methods Forty-one patients with BAV were compared with 165 patients with tricuspid aortic valve (TAV). All patients had LV EF > 50%, normal LV dimensions, and similar degree of aortic root or ascending aorta dilatation at enrollment. Patients with more than mild aortic stenosis or regurgitation were excluded. A CT-scan was available on 76% of the population, and an echocardiogram was repeated every year for a median time of 4 ye…

Computational fluid dynamics of the ascending aorta before the onset of type A aortic dissection.

2016

We performed a pre-dissection computational fluid analysis of an ascending aortic aneurysm associated with unicuspid aortic valve. The analysis showed an abnormal helical flow pattern inside the aneurysm and an increased wall stress on the right postero-lateral wall of the ascending aorta. These values were largely higher than the theoretical cut-off for aortic wall dissection, their topographic distribution followed the intimal tear site as subsequently diagnosed by computed tomography scan and confirmed during the operation for dissection repair.

Shear Stress and Aortic Strain Associations With Biomarkers of Ascending Thoracic Aortic Aneurysm

2019

This study aims to investigate the association of wall shear stress (WSS) and aortic strain with circulating biomarkers including matrix metalloproteinases (MMP), tissue inhibitors of metalloproteinase (TIMP), and exosomal level of microRNA (miRNA) in ascending aortic aneurysms of patients with bicuspid or tricuspid aortic valve.A total of 76 variables from 125 patients with ascending aortic aneurysms were collected from (1) blood plasma to measure plasma levels of miRNAs and protein activity; (2) computational flow analysis to estimate peak systolic WSS and time-average WSS (TAWSS); and (3) imaging analysis of computed tomography angiography to determine aortic wall strain. Principal compo…

Holocene vegetation and fire history of the mountains of Northern Sicily (Italy)

2016

Knowledge about vegetation and fire history of the mountains of Northern Sicily is scanty. We analysed five sites to fill this gap and used terrestrial plant macrofossils to establish robust radiocarbon chronologies. Palynological records from Gorgo Tondo, Gorgo Lungo, Marcato Cixé, Urgo Pietra Giordano and Gorgo Pollicino show that under natural or near natural conditions, deciduous forests (Quercus pubescens, Q. cerris, Fraxinus ornus, Ulmus), that included a substantial portion of evergreen broadleaved species (Q. suber, Q. ilex, Hedera helix), prevailed in the upper meso- mediterranean belt. Mesophilous deciduous and evergreen broadleaved trees (Fagus sylvatica, Ilex aquifolium) dominat…

DETERMINAZIONE DELLE TENSIONI RESIDUE IN GIUNTI FSW A T MEDIANTE METODO DEL CUT-COMPLIANCE

2009

In questo lavoro è stato applicato il metodo del cut-compliance (CC) per la determinzazione delle tensioni residue in giunti friction stir welding (FSW) saldati con una forma T. È riconosciuto che il metodo del CC fornisce ottimi risultati per i giunti di testa la cui geometria è simile al provino CT per prove di fatica. In letteratura, tuttavia, non è presente alcuna applicazione di questo metodo a forme differenti da quelle del giunto di testa poiché non sono note le funzioni di peso e di forma per differenti geometrie. Per tale motivo, sono state effettuate delle simulazioni agli elementi finiti per stimare le funzioni di forma e di peso considerando la geometria dei giunti FSW saldati a…

Surface Measurement by Digital Image Correlation Technique

2008

Early distal remodeling after elephant trunk repair of thoraco-abdominal aortic aneurysms

2016

Hemodynamic alterations occur when the elephant trunk (ET) technique is adopted to treat extensive aortic aneurysms. In planning the 2nd stage operation to complete ET repair, surgeons must weigh an adequate recovery time after initial surgery against the risk of postoperative ET-related complications. The purpose of this study was to understand the mechanistic link between the flow alteration caused by the ET graft and the development of premature aortic rupture before the 2nd stage operation. Specifically, fluid-structure interaction (FSI) analysis was performed using the CT imaging data of aorta at different stages of ET repair, and then computational variables were compared to those obs…

Fatigue resistance of AA2024-T4 friction stir welding joints: Influence of process parameters

2005

Numerical simulation of transcatheter mitral valve replacement: The dynamic implication of LVOT obstruction in the valve-in-ring case.

2022

Transcatheter mitral valve replacement (TMVR) has been used for “off-label” treatment when annuloplasty band ring for mitral repair fails. However, the complex anatomy and function of the mitral valve may lead to fatal complications as a result of the left ventricular outflow tract (LVOT) obstruction in TMVR. We report the structural and hemodynamic response of LVOT obstruction resulting from TMVR with the Edwards SAPIEN 3 Ultra (S3) device. We modified the original Living Heart Human Model (LHHM) to account for a failed mitral valve with an annuloplasty band ring and simulated the cardiac beating condition in the setting of S3 device implantation. Findings demonstrated a high dynamic behav…

Usefulness of regional right ventricular and right atrial strain for prediction of early and late right ventricular failure following a left ventricu…

2019

Background: Identifying candidates for left ventricular assist device surgery at risk of right ventricular failure remains difficult. The aim was to identify the most accurate predictors of right ventricular failure among clinical, biological, and imaging markers, assessed by agreement of different supervised machine learning algorithms. Methods: Seventy-four patients, referred to HeartWare left ventricular assist device since 2010 in two Italian centers, were recruited. Biomarkers, right ventricular standard, and strain echocardiography, as well as cath-lab measures, were compared among patients who did not develop right ventricular failure (N = 56), those with acute–right ventricular fail…

Identification of circumferential regional heterogeneity of ascending thoracic aneurysmal aorta by biaxial mechanical testing

2019

Abstract Ascending thoracic aortic aneurysm (ATAA) in patients with bicuspid aortic valve (BAV) can present an asymmetrical aortic dilatation compared with patients with tricuspid aortic valve (TAV). This pattern of aneurysm dilatation led us to hypothesize that biomechanical differences likely induced by regional heterogeneity of material properties can underlie the observed asymmetric enlargement discrepancies between BAV ATAA and TAV ATAA. This study aimed to characterize the mechanical properties and associated aortic tissue stiffness changes along the circumferential direction of aortic rings collected from surgically-repaired patients with ATAA. Biaxial material testing was performed …

DISSECTION PROPERTIES OF ANEURYSMAL AND NONANEURYSMAL HUMAN ASCENDING THORACIC AORTA: PRELIMINARY RESULTS

2010

Ascending thoracic aortic aneurysm (ATAA) is among the most devastating forms of cardiovascular disease, causing a significant mortality despite current medical and surgical treatments [1]. Moreover these therapies themselves are associated with great risk of mortality or morbidity, complicated by the advanced age of the typical patient, and high surgical costs. The mechanics of spontaneous aortic dissection is not fully understood. It is generally believed that aortic dissection initiates as an intimal tear in which a separation of wall layers produces the formation of a ‘false’ lumen. The dissection may propagate axially and/or circumferentially due to blood flow and pressure. Dissection …

Titanium Lattice Structures Produced via Additive Manufacturing for a Bone Scaffold: A Review

2023

The progress in additive manufacturing has remarkably increased the application of lattice materials in the biomedical field for the fabrication of scaffolds used as bone substitutes. Ti6Al4V alloy is widely adopted for bone implant application as it combines both biological and mechanical properties. Recent breakthroughs in biomaterials and tissue engineering have allowed the regeneration of massive bone defects, which require external intervention to be bridged. However, the repair of such critical bone defects remains a challenge. The present review collected the most significant findings in the literature of the last ten years on Ti6Al4V porous scaffolds to provide a comprehensive summa…

An Updated Checklist of the Sicilian Native Edible Plants: Preserving the Traditional Ecological Knowledge of Century-Old Agro-Pastoral Landscapes

2020

The traditional use of native wild food plants (NWFP) may represent a valuable supplementary food source for the present and future generations. In Sicily, the use of wild plants in the human diet dates back to very ancient times and still plays an important role in some rural communities. Moreover, in this regard, the natural and cultural inheritance of this island is wealthy and diversified for several reasons. First, Sicily hosts a rich vascular flora, with 3,000 native and 350 endemic plants. Second, due to its central position in the Mediterranean, the island has acted as a veritable melting pot for the ethnobotanical knowledge of the rural communities of the entire basin. We reviewed …

Association of Fiber Orientation and Dissection Properties of Ascending Thoracic Aortic Aneurysms With Aortic Valve Morphology

2011

Type A aortic dissection (AoD) of an ascending thoracic aortic aneurysm (ATAA) is a life-threatening cardiovascular emergency with a high potential for death. Despite improved surgical techniques, the morbidity risk for emergent surgery remains 24% worldwide according to data from the International Registry of Acute Aortic Dissection [1].Copyright © 2011 by ASME

Shear stress alterations in the celiac trunk of patients with a continuous-flow left ventricular assist device as shown by in-silico and in-vitro flo…

2017

Background The use of left ventricular assist devices (LVADs) to treat advanced cardiac heart failure is constantly increasing, although this device leads to high risk for gastrointestinal bleeding. Methods Using in-silico flow analysis, we quantified hemodynamic alterations due to continuous-flow LVAD (HeartWare, Inc., Framingham, MA) in the celiac trunk and major branches of the abdominal aorta, and then explored the relationship between wall shear stress (WSS) and celiac trunk orientation. To assess outflow from the aortic branch, a 3-dimensional-printed patient-specific model of the celiac trunk reconstructed from an LVAD-supported patient was used to estimate echocardiographic outflow …

Patients with bicuspid aortic valve are likely to receive an aortic valve prosthesis during prophylactic resection of their ascending aortic aneurysm.

2015

This study aims to evaluate whether thepresence or discovery of a BAV under ATAA repair would impactthe decision-making of the surgical procedure choice.

Grassland fire effect on soil organic carbon reservoirs in a semiarid environment

2013

Abstract. The aim of this work was to investigate the effect of an experimental fire used for grassland management on soil organic carbon (SOC) stocks. The study was carried out on Hyparrhenia hirta (L.) Stapf (Hh) grassland and Ampelodesmos mauritanicus (Desf.) T. Durand & Schinz (Am) grasslands located in the north of Sicily. Soil samples were collected at 0–5 cm before and after the experimental fire, and SOC was measured. During the grassland fire, soil surface temperature was monitored. Biomass of both grasses was analysed in order to determine dry weight and its chemical composition. The results showed that SOC varied significantly with vegetation type, while it is not affecte…

Propagation of Calendula maritima Guss. (Asteraceae) through Biotechnological Techniques for Possible Usage in Phytotherapy

2022

The genus Calendula (Asteraceae) includes several species that are renowned for their therapeutic properties and/or use as ingredients in the preparation of cosmetics. The rare and critically endangered sea marigold, Calendula maritima Guss., an endemic species from Western Sicily, has also been recognized as a potential “farm plant species” for several important compounds used in cosmetics. However, the few remnant populations of this species are currently threatened with extinction because of several factors, such as hybridization with the congeneric species Calendula suffruticosa subsp. fulgida (Raf.) Guadagno and anthropogenic disturbance of its habitat. Therefore, in order to preserve …

Haemodynamic predictors of a penetrating atherosclerotic ulcer rupture using fluid-structure interaction analysis

2013

We present preliminary data on the flow-induced haemodynamic and structural loads exerted on a penetrating atherosclerotic aortic ulcer (PAU). Specifically, one-way fluid-structure interaction analysis was performed on the aortic model reconstructed from a 66-year-old male patient with a PAU that evolved into an intramural haematoma and rupture of the thoracic aorta. The results show that elevated blood pressure (117 mmHg) and low flow velocity at the aortic wall (0.15 m/s(2)) occurred in the region of the PAU. We also found a low value of time-averaged wall shear stress (1.24 N/m(2)) and a high value of the temporal oscillation in the wall shear stress (oscillatory shear index = 0.13) in t…

Grasslands and Shrublands of the Mediterranean Region

2020

The Mediterranean Region extends to the 1.6% of the world’s land surface and more than the half of the Mediterranean-type ecosystems of the world. The remarkable species richness in the Mediterranean Region mainly originates from an exceptional habitat diversity and the presence of several natural barriers facilitating the segregation and differentiation of local taxa and biocoenoses. In this article, we deal with the habitats characterized by grasslands and shrublands that clearly show the adaptations to what could be called “the Mediterranean syndrome”, i.e., the intrazonal Mediterranean grasslands and shrublands (MG&S). The main driving forces of the adaptive radiation and high biodi…

Additional insights on the ecology of the relic tree Zelkova sicula di Pasquale, Garfì et Quézel (Ulmaceae) after the finding of a new population

2011

Abstract In early autumn 2009 a new population of Zelkova sicula, a very threatened tree species endemic to Sicily, has been found some 17 km east from the first and unique population previously known. The abiotic (slope, rock and stone outcrop cover, environmental stress, etc.) and biotic (plant species composition, vegetation mean height, total cover, etc.) features of 30 plots selected within the two populations were investigated in order to contribute at clarifying the actual and potential eco-geographic range of this species. Data analysis showed that the floristic differences among the sampled plots mostly relate to the rather high micro-habitat amplitude of the target species and the…

Patient-specific computational evaluation of stiffness distribution in ascending thoracic aortic aneurysm

2021

Quantifying local aortic stiffness properties in vivo is acknowledged as essential to assess the severity of an ascending thoracic aortic aneurysm (ATAA). Recently, the LESI (local extensional stiffness identification) methodology has been established to quantify non-invasively local stiffness properties of ATAAs using electrocardiographic-gated computed tomography (ECG-gated CT) scans. The aim of the current study was to determine the most sensitive markers of local ATAA stiffness estimation with the hypothesis that direct measures of local ATAA stiffness could better detect the high-risk patients. A cohort of 30 patients (12 BAV and 18 TAV) referred for aortic size evaluation by ECG-gated…

On the Left Ventricular Remodeling of Patients with Stenotic Aortic Valve: A Statistical Shape Analysis

2021

The left ventricle (LV) constantly changes its shape and function as a response to pathological conditions, and this process is known as remodeling. In the presence of aortic stenosis (AS), the degenerative process is not limited to the aortic valve but also involves the remodeling of LV. Statistical shape analysis (SSA) offers a powerful tool for the visualization and quantification of the geometrical and functional patterns of any anatomic changes. In this paper, a SSA method was developed to determine shape descriptors of the LV under different degrees of AS and thus to shed light on the mechanistic link between shape and function. A total of n=86 patients underwent computed tomography (…

Finite-element simulation of residual stress induced by split-sleeve cold-expansion process of holes

2008

A three-dimensional finite-element simulation was conducted for a split-sleeve cold-expansion process in order to determine the residual stress field around an expanded hole. The commercial FEA software DEFORM-3D™, a Lagrangian implicit code designed for metal forming processes, was used to model the cold-expansion process of a fastener hole. The results show a through-thickness residual stress field in good agreement with the analytical solution developed by Guo. Moreover, the simulation has highlighted the effect of the split sleeve and the plate thickness on the residual stress field. © 2007 Elsevier B.V. All rights reserved.

Resistenza a fatica di giunzioni saldate per attrito: influenza dei parametri di processo

2005

Peripheral Artery Disease and Continuous Flow Left Ventricle Assist Device: An Engaging Complement Analysis May Help to Guide Treatment

2018

Use of continuous flow left ventricle assist device (CF-LVAD) in advanced heart failure (HF) patients results in clinically relevant improvements in survival, functional capacity, and quality of life. Peripheral artery disease (PAD) can occur in patients with CF-LVAD due to the high rate of concomitance between risk factors for atherosclerosis and HF. Diagnosis of PAD can be difficult in the specific setting of a patient supported by this kind of device because of the marked alteration in waveform morphology and velocity created by the artificial physiology of an LVAD. We report the case of a 53-year-old man with HF secondary to ischemic cardiomyopathy supported by the HeartWare HVAD as bri…

Holocene vegetation and fire dynamics in the supra-mediterranean belt of the Nebrodi Mountains (Sicily, Italy)

2012

High-resolution pollen, macrofossil and charcoal data, combined with accelerator mass spectrometry 14C dating and multivariate analysis, were used to reconstruct Holocene vegetation and fire dynamics at Urio Quattrocchi, a small lake in the supra-mediterranean belt in the Nebrodi Mountains of Sicily (Italy). The data suggest that after 10 000 cal a BP increasing moisture availability supported closed forests with deciduous (Quercus cerris, Fagus sylvatica and Fraxinus spp.) and evergreen (Quercus ilex) species. Species-rich closed forest persisted until 6850 cal a BP, when Neolithic activities caused a forest decline and affected plant diversity. Secondary forest with abundant Ilex aquifoli…

Biomechanical implications of excessive endograft protrusion into the aortic arch after thoracic endovascular repair

2015

Endografts placed in the aorta for thoracic endovascular aortic repair (TEVAR) may determine malappositioning to the lesser curvature of the aortic wall, thus resulting in a devastating complication known as endograft collapse. This premature device failure commonly occurs in young individuals after TEVAR for traumatic aortic injuries as a result of applications outside the physical conditions for which the endograft was designed. In this study, an experimentally-calibrated fluid-structure interaction (FSI) model was developed to assess the hemodynamic and stress/strain distributions acting on the excessive protrusion extension (PE) of endografts deployed in four young patients underwent TE…

On the role of material properties in ascending thoracic aortic aneurysms

2019

One of the obstacles standing before the biomechanical analysis of an ascending thoracic aortic aneurysm (ATAA) is the difficulty in obtaining patient-specific material properties. This study aimed to evaluate differences on ATAA-related stress predictions resulting from the elastostatic analysis based on the optimization of arbitrary material properties versus the application of patient-specific material properties determined from ex-vivo biaxial testing. Specifically, the elastostatic analysis relies the on the fact that, if the aortic wall stress does not depend on material properties, the aorta has to be statistically determinate. Finite element analysis (FEA) was applied to a group of …

Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT

2014

Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (Delta P) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation Delta P. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of Delta P across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed Delta P was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coeffic…

The effects of post-pasture woody plant colonization on soil and aboveground litter carbon and nitrogen along a bioclimatic transect.

2013

Abstract: We investigated the effects of woody plant colonization of abandoned pastures on soil and litter organic carbon (C) stocks and nitrogen (N) content along a bioclimatic transect in a semi-arid environment (Sicily, Italy). Soil samples were taken in three successional stages (grazed pasture, shrubland, forest) within each of three bioclimates (supramediterranean - “supra”, mesomediterranean - “meso”, thermomediterranean - “thermo”). Organic C and N in litter and soil (0-10 cm and 10-30 cm depth) were determined, as well as soil bulk density. Especially at 0-10 cm depth, changes in C and N contents along successional stages differed among bioclimates. Soil organic carbon (SOC) stock …

Computational modeling of bicuspid aortopathy: Towards personalized risk strategies.

2019

This paper describes current advances on the application of in-silico for the understanding of bicuspid aortopathy and future perspectives of this technology on routine clinical care. This includes the impact that artificial intelligence can provide to develop computer-based clinical decision support system and that wearable sensors can offer to remotely monitor high-risk bicuspid aortic valve (BAV) patients. First, we discussed the benefit of computational modeling by providing tangible examples of in-silico software products based on computational fluid-dynamic (CFD) and finite-element method (FEM) that are currently transforming the way we diagnose and treat cardiovascular diseases. Then…

Mid- and late-Holocene vegetation and fire history at Biviere di Gela, a coastal lake in southern Sicily, Italy

2009

The vegetation and fire history of few coastal sites has been investigated in the Mediterranean region so far. We present the first paleoecological reconstruction from coastal Sicily, the largest island in the Mediterranean Sea. We analysed pollen and charcoal in the sediments of Biviere di Gela, a lake (lagoon) on the south coast of Sicily. Our data suggest that the area became afforested after a marine transgression at ca. 7200 cal b.p. (5250 b.c.). Build-up of forest and shrublands took ca. 200–300 years, mainly with the deciduous trees Quercus, Ostrya and Fraxinus. Juniperus expanded ca. 6900 cal b.p. (4950 b.c.), but declined again 6600 cal b.p. (4650 b.c.). Afterwards, evergreen trees…

Achievements, flaws, and future goals of scientific research on green roofs in mediterranean cities: first feedback from ongoing meta-analysis

2022

Current scientific research points out the low number of papers focused on the environmental patterns in Mediterranean urban areas, where green infrastructure is still strongly underrated by scientists as well as by politicians, planners and decision-makers. In this paper, the results of a simple meta-analysis on the topics treated in scientific literature about the Mediterranean green roofs (MGRs) are presented. Our review pointed out the strikingly higher attention paid to building materials, energy efficiency and hydraulics with respect to life sciences (including basic ecology, horticulture, soil, plant and animal sciences) in the target paper selection. In fact, despite the availabilit…

Criteria to identify old-growth forests in the Mediterranean: A case study from Sicily based on a literature review and some management proposals

2018

Old growth forests are increasingly considered and studied all around the world. However, the knowledge of such important forest systems is still limited in some bioclimatic regions, such as in the Mediterranean Basin. Starting from the knowledge acquired elsewhere, our research was carried out with the aim to select the most effective criteria to identify potential old-growth forests in Mediterranean ecosystems (Sicily, Italy). Four key proxy indicators were considered: deadwood amount, tree size, structural traits, and tree species richness. A preliminary classification of the local forest stands level in three classes of old-growthness (high, medium and low) has also been proposed. The m…

An In Vitro Phantom Study on the Role of the Bird-Beak Configuration in Endograft Infolding in the Aortic Arch.

2015

Purpose: To assess endograft infolding for excessive bird-beak configurations in the aortic arch in relation to hemodynamic variables by quantifying device displacement and rotation of oversized stent-grafts deployed in a phantom model. Methods: A patient-specific, compliant, phantom pulsatile flow model was reconstructed from a patient who presented with collapse of a Gore TAG thoracic endoprosthesis. Device infolding was measured under different flow and pressure conditions for 3 protrusion extensions (13, 19, and 24 mm) of the bird-beak configuration resulting from 2 TAG endografts with oversizing of 11% and 45%, respectively. Results: The bird-beak configuration with the greatest protr…

Comportamento a frattura di un composito particolato

2008

A mechanistic model on the role of “radially-running” collagen fibers on dissection properties of human ascending thoracic aorta.

2014

Aortic dissection (AoD) is a common condition that often leads to life-threatening cardiovascular emergency. From a biomechanics viewpoint, AoD involves failure of load-bearing microstructural components of the aortic wall, mainly elastin and collagen fibers. Delamination strength of the aortic wall depends on the load-bearing capacity and local micro-architecture of these fibers, which may vary with age, disease and aortic location. Therefore, quantifying the role of fiber micro-architecture on the delamination strength of the aortic wall may lead to improved understanding of AoD. We present an experimentally-driven modeling paradigm towards this goal. Specifically, we utilize collagen fib…

Fatigue crack propagation from a cold-worked hole

2007

Abstract The cold expansion process is widely used to enhance the fatigue life of structures with fastener holes. Various studies assert that the cold expansion improves the fatigue strength of fastener holes; however, the improvement of fatigue life is difficult to quantify. Therefore, the influence on fatigue life of cold-worked process was studied by numerical and experimental tests. Then, a parametric study on material hardening behavior and Bauschinger’s parameter was performed for several loading conditions in order to determine their effect on crack growth propagation. The results of the numerical tests have exhibited a good prediction of the fatigue life of the component.

Particle image velocimetry study of the celiac trunk hemodynamic induced by continuous-flow left ventricular assist device

2017

Abstract Whereas left ventricular assist device (LVAD) is the gold-standard therapy for patients with heart failure, gastrointestinal bleeding is one of the most common complications. LVAD implantation may remarkably impact aortic hemodynamics so that experimental and computational flow analyses can be used to study the disease mechanisms. Here we present an experimentally-calibrated computational model of the celiac trunk hemodynamic of a LVAD-supported patient who experienced bleeding after device implantation. Specifically, both particle image velocimetry (PIV) and echocardiography were used to measure and compare flow distributions in each branch of a phantom model of the patient abdomi…

Predicting Outcome of Aortic Dissection with Patent False Lumen by Computational Flow Analysis

2014

Although Type B aortic dissection (AoD) has better in-hospital survival than Type A AoD, the short- and long term outcome for patients remains challenging, with 50–80% deaths at 5-years. Dissection-related complications include rapid aortic expansion, impending rupture, and malperfusion syndromes. We aimed to assess hemodynamic implications of patients with patent false lumen (FL) of dissected aorta. Computational fluid dynamic analyses were performed on patient-specific aortic geometries reconstructed from computed tomography scans of 25 patients with AoDs, who were admitted in our hospital from 2007 to 2013. We used the development of acute complications and chronic aneurysmal evolution a…

Crack growth analysis at adhesive–adherent interface in bonded joints under mixed mode I/II

2008

The propagation of an interface crack subjected to mixed mode I/II was investigated for two 2024-T351 aluminum thin layers joined by means of DP760 epoxy adhesive produced by 3M©. On the basis of beam theory, an analytical expression for computing the energy release rate is presented for the mixed-mode end loaded split (MMELS) test. The analytical strain energy release rate was compared by finite element (FE) analysis using the virtual crack closure technique (VCCT). Several fatigue crack growth tests were carried out in a plane bending machine to compare the experimental energy release rates to those of the analytical and FE solutions. Experimental results showed the relationship between t…

Framework for Fluid-Structure Interaction Analysis of Aortic Coarctation Resulting From Proximal Protusion of Thoracic Aortic Stent Graft Into the Ar…

2011

Thoracic aortic stent grafts (TASG) are commonly used to repair aortic anomalies or diseases in a minimally-invasive fashion. One complication of TASG is collapse, whereby blood is unable to completely flow through the graft as intended. Most TASG collapses occur in the setting of endovascular repair of traumatic thoracic aortic transection, where a typically smaller diameter aorta of pediatric patients is repaired with a relatively larger diameter endograft designed to treat aneurysmal disease [1]. It is hypothesized that the poor apposition of the leading edge of the proximal stent graft to the lesser curvature of the aortic arch can result increased hemodynamic force at the leading side …

Simulation study of transcatheter heart valve implantation in patients with stenotic bicuspid aortic valve

2019

Bicuspid aortic valve (BAV) anatomy has routinely been considered an exclusion in the setting of transcatheter aortic valve implantation (TAVI) because of the large dimension of the aortic annulus having a more calcified, bulky, and irregular shape. The study aims to develop a patient-specific computational framework to virtually simulate TAVI in stenotic BAV patients using the Edwards SAPIEN 3 valve (S3) and its improved version SAPIEN 3 Ultra and quantify stent frame deformity as well as the severity of paravalvular leakage (PVL). Specifically, the aortic root anatomy of n.9 BAV patients who underwent TAVI was reconstructed from pre-operative CT imaging. Crimping and deployment of S3 fram…

Pre-Operative Modeling of Transcatheter Mitral Valve Replacement in a Surgical Heart Valve Bioprosthesis

2020

Obstruction of the left ventricular outflow tract (LVOT) is a common complication of transcatheter mitral valve replacement (TMVR). This procedure can determine an elongation of an LVOT (namely, the neo-LVOT), ultimately portending hemodynamic impairment and patient death. This study aimed to understand the biomechanical implications of LVOT obstruction in a patient who underwent TMVR using a transcatheter heart valve (THV) to repair a failed bioprosthetic heart valve. We first reconstructed the heart anatomy and the bioprosthetic heart valve to virtually implant a computer-aided-design (CAD) model of THV and evaluate the neo-LVOT area. A numerical simulation of THV deployment was then deve…

A new subspecies of Epipactis microphylla (Orchidaceae; Epidendroideae) from Pantelleria Island (Sicily)

2021

A new subspecies of Epipactis microphylla, proposed as subsp. cossyrensis is described and illustrated from Pantelleria, a volcanic island near Sicily. It differs from subsp. microphylla mainly in the shape and size of leaves and bracts and several floral traits. This taxon, previously attributed to E. pollinensis, a species currently treated as a synonym of E. purpurata, grows in the undergrowth of thermophilous woodlands occurring on the top of the island, where it numbers a few tens of individuals. The conservation status, phenology and taxonomic remarks are provided. Keys for the species belonging to the Epipactis atrorubens group (= subsect. Atrorubensae), including E. microphylla, are…

Transcatheter Heart Valve Implantation in Bicuspid Patients with Self-Expanding Device

2021

Bicuspid aortic valve (BAV) patients are conventionally not treated by transcathether aortic valve implantation (TAVI) because of anatomic constraint with unfavorable outcome. Patient-specific numerical simulation of TAVI in BAV may predict important clinical insights to assess the conformability of the transcathether heart valves (THV) implanted on the aortic root of members of this challenging patient population. We aimed to develop a computational approach and virtually simulate TAVI in a group of n.6 stenotic BAV patients using the self-expanding Evolut Pro THV. Specifically, the structural mechanics were evaluated by a finite-element model to estimate the deformed THV configuration in …

FIBER DISTRIBUTION OF ASCENDING THORACIC AORTIC ANEURYSMS ASSOCIATED WITH VALVE MORPHOLOGY

2012

Computer Modeling for the Prediction of Thoracic Aortic Stent Graft Collapse

2011

OBJECTIVE: To assess the biomechanical implications of excessive stent protrusion into the aortic arch in relation to thoracic aortic stent graft (TASG) collapse by simulating the structural load and quantifying the fluid dynamics on the TASG wall protrusion extended into a model arch. METHODS: One-way coupled fluid-solid interaction analyses were performed to investigate the flow-induced hemodynamic and structural loads exerted on the proximal protrusion of the TASG and aortic wall reconstructed from a patient who underwent traumatic thoracic aortic injury repair. Mechanical properties of a Gore TAG thoracic endoprosthesis (W. L. Gore and Assoc, Flagstaff, Ariz) were assessed via experimen…

On the Residual Stresses in Friction Stir-Welded Parts: Effect of the Geometry of the Joints

2010

Residual stress state is a fundamental aspect of welded joints, especially when complex geometries are considered. In this article, the residual longitudinal stresses in friction stir-welded joints were measured. In particular, different joint configurations were taken into account, namely butt joints, T, and lap ones, the latter being definitively interesting case studies with reference to applications in the transportation industries and, particularly in the aerospace industries.

Difference in hemodynamic and wall stress of ascending thoracic aortic aneurysms with bicuspid and tricuspid aortic valve.

2012

The aortic dissection (AoD) of an ascending thoracic aortic aneurysm (ATAA) initiates when the hemodynamic loads exerted on the aneurysmal wall overcome the adhesive forces holding the elastic layers together. Parallel coupled, two-way fluid–structure interaction (FSI) analyses were performed on patient-specific ATAAs obtained from patients with either bicuspid aortic valve (BAV) or tricuspid aortic valve (TAV) to evaluate hemodynamic predictors and wall stresses imparting aneurysm enlargement and AoD. Results showed a left-handed circumferential flow with slower-moving helical pattern in the aneurysm's center for BAV ATAAs whereas a slight deviation of the blood flow toward the anterolater…

IDPlanT: the Italian database of plant translocation

2021

IDPlanT is the Italian Database of Plant Translocation, an initiative of the Nature Conservation Working Group of the Italian Botanical Society. IDPlanT currently includes 185 plant translocations. The establishment of a national database on plant translocation is a key step forward in data sharing and techniques improvement in this field of plant conservation. Supplemental data for this article is available online at https://doi.org/10.1080/11263504.2021.1985004.

On the thermo-mechanical loads and the resultant residual stresses in friction stir processing operations

2008

In friction stir welding and processing both a thermal flux and a mechanical action are exerted on the material determining metallurgical evolutions, changes in the mechanical behaviour and a complex residual stress state. In the paper, the metallurgical changes are examined through numerical simulation and experiments to highlight and distinguish the effects of thermal and mechanical loadings. A particular focus is made on the residual stresses generated during the stir processing of AA7075-T6 aluminium blanks. The predictions of FE model are validated by experimental measurements. Lastly, this paper presents an in-process quenching of the processed blanks for improved mechanical propertie…

A Plant Sociological Procedure for the Ecological Design and Enhancement of Urban Green Infrastructure

2021

AbstractUrban green infrastructure could represent an important mean for environmental mitigation, if designed according to the principles of restoration ecology. Moreover, if suitably executed, managed and sized, they may be assimilated to meta-populations of natural habitats, deserving to be included in the biodiversity monitoring networks. In this chapter, we combined automatised and expert opinion-based procedures in order to select the vascular plant assemblages to populate different microhabitats (differing in terms of light and moisture) co-occurring on an existing green roof in Zurich (Switzerland). Our results lead to identify three main plant species groups, which prove to be the …

Biomechanics and Pathobiology of Aortic Aneurysms

2011

Biomechanical weakening of the aorta leads to aneurysm formation and/or dissection and total biomechanical failure results in rupture, which is often fatal. The most common aneurysm is the abdominal aortic aneurysm (AAA) whereas thoracic aortic aneurysms (TAA) involve the ascending or descending segments of the aorta. Biomechanical strength of the aorta is maintained in part via balance between the integrity of the aortic medial and adventitial extracellular matrix and the health of the mural cells. From a biomechanical perspective, aneurysms rupture or dissect when wall stresses locally exceed the wall strength. Pathobiologic mechanisms, pre-disposing disorders and variability of patient d…

Constitutive modeling of ascending thoracic aortic aneurysms using microstructural parameters.

2016

Ascending thoracic aortic aneurysm (ATAA) has been associated with diminished biomechanical strength and disruption in the collagen fiber microarchitecture. Additionally, the congenital bicuspid aortic valve (BAV) leads to a distinct extracellular matrix structure that may be related to ATAA development at an earlier age than degenerative aneurysms arising in patients with the morphological normal tricuspid aortic valve (TAV). The purpose of this study was to model the fiber-reinforced mechanical response of ATAA specimens from patients with either BAV or TAV. This was achieved by combining image-analysis derived parameters of collagen fiber dispersion and alignment with tensile testing dat…

A study on the effect of contact pressure during physical activity on photoplethysmographic heart rate measurements

2020

Heart rate (HR) as an important physiological indicator could properly describe global subject&rsquo

An analysis of carbon storage protected areas with relation to agroforestry management and biodiversity

2008

This work investigated the role of land cover and land use change (LUC) as a soil ability to store carbon and reduce carbon dioxide emission in a Mediterranean area. Using a paired site approach we estimated the effect of land cover change on the carbon stock from 1972 to 2008 in a natural reserve (Grotta di S. Ninfa) in the West of Sicily. Fifteen paired sites representative of five land use change were selected. We studied the effect of land use on soil organic carbon (SOC) content in bulk soil and 2000-1000 µm, 1000-500 µm, 500-250 µm, 250-63 µm, 63-25 µm and <25 µm size fractions. Furthermore, laboratory incubation of the soil samples was conducted to measure carbon dioxide evolution in…

A preliminary investigation of the effect of contact pressure on the accuracy of heart rate monitoring by wearable PPG wrist band

2019

The increase of safety and health monitor of workers has become a crucial objective to prevent excessive physical workloads, injuries, accidents and errors. Heart rate (HR) is a very important physiological indicator which could properly describe the workers’ physical status. Recently, wearable photoplethysmographic (PPG) wristband trackers have been utilized to measure HR without hindering normal gesture of workers. However, the quality of PPG signals is highly affected by human physical motions, resulting in a poor reliable HR estimation. Specifically, during different activities and gestures, PPG sensor contact pressures may have an impact on the quality of the heart rate signal. To appr…

Relationship between recruitment and mother plant vitality in the alien species Acacia cyclops A. Cunn. ex G. Don

2014

Acacia cyclops is a widespread invader in Mediterranean-climate regions. However, although its naturalization in the Mediterranean Basin dates back only a few years ago, and the invasion process has not been studied hitherto. We investigated seedlings recruitment strategy adopted by A. cyclops in a small island (Lampedusa, Italy) where its natural regeneration was strictly confined under mother plants canopy. Healthy plants (DCP), plants at incipient senescence (SCP) and dead plants (DP) were distinguished according to vitality and canopy status. Living plants were also characterized in relation to leaf C and N isotope composition. Regeneration pattern (seedlings and saplings abundance) was…

Relevant habitats neglected by the Directive 92/43 EEC: the contribution of Vegetation Science for their reappraisal in Sicily

2021

Field investigation carried out by the Sicilian botanists in the last 20 years enabled them to identify eight habitat types of high biogeographic and conservation interest, neglected by the Directive 92/43, which deservead hocconservation measures. For each of these habitats, a syntaxonomic interpretation of the corresponding plant communities, their main ecological, physiognomic and syndynamic traits and a list of diagnostic species are provided. Their classification into the macrotypes listed in the Annex I of the Directive 92/43 and the respective correspondence in EUNIS habitat classification are proposed. The habitats here described integrate those already proposed by the Italian Botan…

Comportamento a fatica di giunti a T friction stir wleded in lega di alluminio

2008

CAD Modeling for Evaluating LVOT Obstruction in Transcatheter Mitral Valve Replacement

2019

The current generation of transcatheter heart valves (THV), as the Edwards SAPIEN 3 Ultra (S3), is not specifically designed for mitral position implantation and has intrinsic design geometry that may make mitral implantation suboptimal. This study aimed to develop a computed-tomography (CT) based CAD workflow for the preoperative planning of transcatheter mitral valve replacement (TMVR) by evaluating the resulting obstruction in the left ventricular outflow tract (LVOT). Specifically, the computational framework to reconstruct heart anatomy and virtually deploy the THV into mitral valve annulus was developed and successively applied to the cases of two patients who experienced annuloplasty…

Urban Services to Ecosystems: An Introduction

2021

Green infrastructure is a structural system of naturally developed human societies, capable of preserving and ensuring as much space as possible to the local biodiversity. For this reason, green infrastructure shall be planned and designed so that the urban built environment is in harmony with the surrounding biotic communities. The challenge is to sustain nature-based solutions in order to improve citizens’ awareness towards natural and semi-natural ecosystems while providing our society with a more liveable, healthier, safer and fairer environment. This book puts an emphasis on the services the city can offer to nature, thanks to a multidisciplinary approach involving scientists and pract…

Studio numerico-sperimentale sulla resistenza a fatica di sistemi di cementazione per inlay in composito

2009

Nel lavoro è valutata la resistenza a fatica di tre diversi tipi di cementazione per inlay in composito utilizzati in ambito odontoiatrico per il restauro dei denti anteriori e posteriori. Il comportamento meccanico dei diversi sistemi di cementazione è stato ricavato sperimentalmente mediante prove di fatica in controllo di carico e riprodotto numericamente mediante simulazioni numeriche agli elementi finiti (FEM). Le diverse simulazioni hanno permesso di prevedere lo stato tensionale e l’evoluzione di una delaminazione all’interfaccia bi-materiale.

A multifaceted field sampling approach for the management of extremely narrow endemic vascular plant species

2022

Extremely narrow endemic plant species (ENEs) are generally connected with micro- refugia characterized by particular environmental conditions. In-depth knowledge of the ecological requirements of ENEs is fundamental to plan appropriate conservation measures. Using cross-cutting technology, this paper gives a multifaceted approach to collect on-site data on the ecology of ENEs, defines the protocols for a correct sampling design and describes the type of equipment, the time and expenditure needed. Our sampling approach is based on two orthogonal transects, long enough to extrapolate the whole ecological gradient across the area of occupancy of the target species. Microclimatic data are reco…

Acacia cyclops A. Cunn. ex G. Don (Leguminosae) in Italy: first cases of naturalization

2012

The first two cases of naturalization of Acacia cyclops are reported for Italy. Young trees were observed growing in the wild some 15 years ago on Linosa (Pelagie Islands, Strait of Sicily). A decade later, this alien plant should no longer be considered as a casual, since a very intensive process of self-sown regeneration has been observed in some plantations on Lampedusa, the major island of the same Archipelago. The available literature suggests the need for careful monitoring of the ongoing invasion process, as A. cyclops has already shown a very invasive behaviour elsewhere within Mediterranean-type biomes due to its ability to withstand high environmental stresses. As migrating birds …

Effect of residual stresses and their redistribution on the fatigue crack growth in cold-worked holes

2009

The cold-expansion process is widely used to enhance the fatigue life of structures with fastener holes. Various studies assert that the cold-expansion improves the fatigue strength of fastener holes; however, the improvement of fatigue life is difficult to quantify. The influence on fatigue life of cold-worked hole in a 6061-T6 alluminum allosy was studied by numerical and experimental tests. Fatigue crack growth tests were carried out to find the crack length and growth rates of crack propagating from hole edge. Thus, the cold-expansion process was modeled with a Lagrangian implicit code for metal forming to obtain the residual stress field. Progressive crack growth along the observed fat…

Propagazione di difetti all’interfaccia adesivo aderendo in giunti incollati

2006

In Vitro Measurement of Strain Localization Preceding Dissection of the Aortic Wall Subjected to Radial Tension

2020

AbstractBackgroundAortic dissection (AD) is a common pathology and challenging clinical problem. A better understanding of the biomechanical effects preceding its initiation is essential for predicting adverse events on a patient-specific basis. Moreover, the predictability of patient-specific biomechanics-based computational models is hampered by uncertainty about boundary conditions and material properties.ObjectivePredisposition of thoracic aortic aneurysms (TAA) to ADs can be related to the degradation of biomechanically important constituents in the aortic wall of TAAs. The goal of the present study is to develop a new methodology to measure strain fields in aortic tissues subjected to…

Deep learning approach for the segmentation of aneurysmal ascending aorta.

2020

Diagnosis of ascending thoracic aortic aneurysm (ATAA) is based on the measurement of the maximum aortic diameter, but size is not a good predictor of the risk of adverse events. There is growing interest in the development of novel image-derived risk strategies to improve patient risk management towards a highly individualized level. In this study, the feasibility and efficacy of deep learning for the automatic segmentation of ATAAs was investigated using UNet, ENet, and ERFNet techniques. Specifically, CT angiography done on 72 patients with ATAAs and different valve morphology (i.e., tricuspid aortic valve, TAV, and bicuspid aortic valve, BAV) were semi-automatically segmented with Mimic…

Modeling Right Ventricle Failure After Continuous Flow Left Ventricular Assist Device: A Biventricular Finite-Element and Lumped-Parameter Analysis

2017

The risk of right ventricle (RV) failure remains a major contraindication for continuous-flow left ventricular assist device (CF-LVAD) implantation in patients with heart failure. It is therefore critical to identify the patients who will benefit from early intervention to avoid adverse outcomes. We sought to advance the computational modeling description of the mechanisms underlying RV failure in LVAD-supported patients. RV failure was studied by computational modeling of hemodynamic and cardiac mechanics using lumped-parameter and biventricular finite element (FE) analysis. Findings were validated by comparison of bi-dimensional speckle-tracking echocardiographic strain assessment of the …

In Silico Shear and Intramural Stresses are Linked to Aortic Valve Morphology in Dilated Ascending Aorta

2017

Objective/Background: The development of ascending aortic dilatation in patients with bicuspid aortic valve (BAV) is highly variable, and this makes surgical decision strategies particularly challenging. The purpose of this study was to identify new predictors, other than the well established aortic size, that may help to stratify the risk of aortic dilatation in BAV patients.Methods: Using fluid-structure interaction analysis, both haemodynamic and structural parameters exerted on the ascending aortic wall of patients with either BAV ( n = 21) or tricuspid aortic valve (TAV; n = 13) with comparable age and aortic diameter (42.7 +/- 5.3 mm for BAV and 45.4 +/- 10.0 mm for TAV) were compared…

1200 years of decadal-scale variability of Mediterranean vegetation and climate at Pantelleria Island, Italy.

2013

A new sedimentary sequence from Lago di Venere on Pantelleria Island, located in the Strait of Sicily between Tunisia and Sicily was recovered. The lake is located in the coastal infra-Mediterranean vegetation belt at 2 m a.s.l. Pollen, charcoal and sedimentological analyses are used to explore linkages among vegetation, fire and climate at a decadal scale over the past 1200 years. A dry period from ad 800 to 1000 that corresponds to the 'Medieval Warm Period' (WMP) is inferred from sedimentological analysis. The high content of carbonate recorded in this period suggests a dry phase, when the ratio of evaporation/precipitation was high. During this period the island was dominated by thermop…

Fatigue crack growth in 2024-T351 Friction Stir Welded Joints: longitudinal residual stresses and microstructural effects

2009

Abstract The role of longitudinal residual stress on propagation of fatigue cracks was examined in friction stir welds produced in 2024-T351 aluminum alloy. Fatigue crack growth rate was obtained through constant Δ K Iapp tests for notches at different distances from the weld centerline. Subsequently, crack growth was correlated to weld residual stress measured by the cut-compliance method. It was found that residual stresses correspond to low crack growth rates outside the weld zone during fatigue loading. Once in the weld zone, the crack growth was affected by microstructural and hardness changes. Furthermore, weld residual stresses were mechanically relieved and effects on crack propagat…

TAVI imaging: over the echocardiography

2020

Aortic valve stenosis (AS) is a common valvular heart disease. Recently, transcatheter aortic valve implantation (TAVI) has changed the treatment of severe AS in elderly patients with contraindications to traditional surgical replacement. Echocardiography is conventionally used as the first imaging modality to assess the presence and severity of AS and to provide anatomical and functional information. Nowadays, imaging techniques play a crucial role in the planning of TAVI to define suitable candidates. Computed tomography (CT) is essential to display the anatomy of the aortic valve complex (including aortic annulus, Valsalva sinuses, coronary arteries ostia, sinotubular junction), thoracoa…

The past distribution of Abies nebrodensis (Lojac.) Mattei: results of a multidisciplinary study

2019

The present study provides a critical review of the available historical data on the distribution of Abies nebrodensis, a fir tree endemic to Sicily. The only (somewhat ambiguous) references to its occurrence on Mount Etna date back to the 1st century bc and refer back to the 3rd century bc. Although the botanical and forestry literature and the very few surviving herbarium specimens do not prove that A. nebrodensis grew outside the Madonie mountain range, several indications suggest its past occurrence on other Sicilian mountain ranges such as the Erei, Nebrodi, and probably also Sicani mountains. The results of the most recent pollen investigations (still ongoing) point to the disappearan…

Displacement measurement through DIC and DSPI techniques in cold-expanded holes

2008

In this paper, the displacement field induced by the split-sleeve cold expansion of holes was measured using both digital image correlation (DIC) and digital speckle pattern interferometry (DSPI) techniques. Thus, the experimental results, which were evaluated on the inlet surface of a 6082-T6 aluminium plate, were compared with those from theoretical prediction. DIC provided accurate measurements up to the elastic-plastic boundary, whereas the DSPI technique highlighted the changes of displacement in the elastic domain. Prediction of the displacement based on the existing analytical model agreed with the experimental results achieved with both techniques. Possible explanations for the diff…

A casual alien plant new to Mediterranean Europe: Ceiba speciosa (Malvaceae) in the suburban area of Palermo (NW Sicily, Italy)

2014

The abiotic and biotic characteristics of the first sites where floss silk tree behaves as a casual alien plant in the Mediterranean Europe are described. The species was probably first planted in botanical gardens of southern France few decades before mid XIX century. It was introduced in Palermo in 1896, a city which appears to match very well its climatic requirements. According to the available information on its biology and ecology in both its original and secondary range, the floss silk tree should not become an invasive alien plant in the Mediterranean. Nevertheless, several gaps need to be filled in order to increase our understanding of future trends of Ceiba speciosa in southern E…

Floristic and Vegetation Changes on a Small Mediterranean Island over the Last Century

2021

A synthetic and updated overview about the vascular flora and vegetation of the Island of Capo Passero (SE-Sicily) is provided. These data issue from two series of field surveys—the first carried out between 1997 and 2000, and the second between 2005 and 2019 and mostly focused on refining and implementing vegetation data. The current islet’s flora consists of 269 taxa, of which 149 (58%) are annual plants. The Mediterranean species are largely prevailing, 108 (40%) of which have a strictly Mediterranean biogeographical status. The comparison with a species list published in 1919 and updated in 1957 suggest that, despite the overall prevalence of anemochorous taxa, the vertebrate fauna repr…

Displacement Measurement Through Digital Image Correlation and Digital Speckle Pattern Interferometry Techniques in Cold-Expanded Holes

2010

:  In this paper, the displacement field induced by the split-sleeve cold expansion of holes was measured using both digital image correlation (DIC) and digital speckle pattern interferometry (DSPI) techniques. Thus, the experimental results, which were evaluated on the inlet surface of a 6082-T6 aluminium plate, were compared with those from theoretical prediction. DIC provided accurate measurements up to the elastic–plastic boundary, whereas the DSPI technique highlighted the changes of displacement in the elastic domain. Prediction of the displacement based on the existing analytical model agreed with the experimental results achieved with both techniques. Possible explanations for the d…

Fatigue crack growth through particulate clusters in polycarbonate material

2011

The interaction of a crack with a perfectly bonded inclusion or a cluster of inclusions in polycarbonate matrix was investigated through both numerical simulations and fatigue tests. Stress intensity factors (K(I)) were evaluated by boundary element method for several particle sizes, position and finally for inclusion cluster as a precursor study for the experiments. The numerical simulation has shown the crack tendency to circumvent the inclusions with consequential reduction of the growth rate. Fatigue crack growth tests were carried out on several particle-filled specimens at constant value of the applied stress intensity factor range (Delta K(Iapp)) highlighting the crack delay due to t…

Mechanics of pericardial effusion: A simulation study

2015

Pericardial effusion is a pathological accumulation of fluid within pericardial cavity, which may compress heart chambers with hemodynamic impairment. We sought to determine the mechanics underlying the physiology of the hemodynamic impairment due to pericardial effusion using patient-specific computational modeling. Computational models of left ventricle and right ventricle were based on magnetic resonance images obtained from patients with pericardial effusion and controls. Myocardial material parameters were adjusted, so that volumes of ventricular chambers and pericardial effusion agreed with magnetic resonance imaging data. End-diastolic and end-systolic pressure–volume relationships …

Combining ecological engineering and plant conservation on a Mediterranean islet

2012

This paper reports the results of a bioengineering intervention within the Mediterranean Basin carried out at Lampedusa Island (Strait of Sicily) on the “Spiaggia dei Conigli”, the only sand shore of all Sicilian territory where the sea turtle Caretta caretta lays its eggs every year. The erosion of the steep slope over the beach itself caused sensitive changes in the grain size of shore’s sediment and reduced the area of the beach with fine sand suitable for C. caretta oviposition. In order to reduce surface water flow and to stop erosion, several bioengineering options were adopted using only native plant species to preserve local botanical heritage and to prevent the local extinction of …

Residual stresses and FCP prediction in FSW through a continuous FE model

2009

Abstract Residual stresses prediction is definitively a relevant and open issue in welding processes. In the last years, different numerical models are proposed by many researchers to predict the residual stress field in FSW butt joint. However, most of these works are based on properly tuned analytical models and neglect the effect of the mechanical action due to the presence of the tool pin. In the present paper, a continuous 3D FE model, which was previously developed by some of the authors, was used to simulate the FSW process of butt joints with a single block approach, and predict the residual stress field by considering both thermal and mechanical actions. Then, the residual stress e…

Resistenza a fatica di tre diversi sistemi di cementazione per inlay in composito.

2007

Residual Stress Effects on Fatigue Crack Growth in Ti-6Al-4V Friction Stir Welds

2008

Recent studies have illustrated a predominant role of the residual stress on the fatigue crack growth in friction stir welded joints. In this study, the role of the residual stress on the propagation of fatigue cracks orthogonal to the weld direction in a friction stir welded Ti-6Al-4V joint was investigated. A numerical prediction of the fatigue crack growth rate in the presence of the residual stresses was carried out using AFGROW software; reasonable correspondence between the predictions and the experimental results were observed when the effects of residual stress were included in the simulation.

Special Issue on “Frontier Biomechanical Challenges in Cardiovascular Physiopathology”

2017

This special issue collects a number of original contributions, which were presented and discussed during the thematic Symposium organized by the Italian Chapter of the European Society of Biomechanics (ESB) in collaboration with the Mediterranean Institute for Transplantation and Advanced Specialized Therapies (ISMETT – IRCCS), the Fondazione RiMED and the University of Palermo. The Symposium focused on recent advances in cardiovascular biomechanics, and the promise they hold for clinical therapeutic strategies and future research.

The paradox of the alien plant Leucaena leucocephala subsp. glabrata (Rose) S. Zárate in Sicily: another threat for the native flora or a valuable re…

2020

With this contribution, an updated picture of the rapid expansion of Leucaena leucocephala subsp. glabrata in Sicily is provided. On the one hand, this is a quite worrying sign, as this woody species figures among the world’s worst invasive alien species. On the other hand, the species shows interesting potential for production purposes (for wood, biomass and for feeding livestock), also considering its nitrogen fixation ability. Consequently, the two opposite options to cope with this species, i.e. cultivation and control/eradication, should accurately take into account the possible uses as well as its invasive behaviou.

Effetti delle tensioni residue sulla propagazione di cricche in giunti FSW in lega di alluminio

2007

Development of a self-pumping extracorporeal blood oxygenation device characterized by a rotating shaft with embedded fiber packages.

2019

Introduction: To offer respiratory support for patients with lung disease, a novel technological solution for blood pumping and oxygenation is being developed. The pump–lung system was designed to integrate fiber membranes into six packages radially embedded in a rotating hollow shaft placed along the longitudinal axis of the device. Fiber packages are inclined with respect to the rotation axis so that the rotational motion of the rotating shaft allows a self-pumping system to be obtained. Method: Both hemodynamic and gas transfer performances were investigated using both in vitro experiments and in silico flow analyses. Results: The predicted flow velocity in the pump chamber was smooth an…

Supplementary material 1 from: Musarella CM, Mendoza-Fernández AJ, Mota JF, Alessandrini A, Bacchetta G, Brullo S, Caldarella O, Ciaschetti G, Conti …

2018

Plant species data :

IDPlanT: the Italian database of plant translocation

2021

IDPlanT is the Italian Database of Plant Translocation, an initiative of the Nature Conservation Working Group of the Italian Botanical Society. IDPlanT currently includes 185 plant translocations. The establishment of a national database on plant translocation is a key step forward in data sharing and techniques improvement in this field of plant conservation. Supplemental data for this article is available online at https://doi.org/10.1080/11263504.2021.1985004 .

Supplementary material 2 from: Musarella CM, Mendoza-Fernández AJ, Mota JF, Alessandrini A, Bacchetta G, Brullo S, Caldarella O, Ciaschetti G, Conti …

2018

ANOVA analysis by gypsophily level :

Urban Services to Ecosystems - Green Infrastructure Benefits from the Landscape to the Urban Scale

2021

The aim of this book is to bring together multidisciplinary research in the field of green infrastructure design, construction and ecology. The main core of the volume is constituted by contributions dealing with green infrastructure, vegetation science, nature-based solutions and sustainable urban development. The green infrastructure and its ecosystem services, indeed, are gaining space in both political agendas and academic research. However, the attention is focused on the services that nature is giving for free to and for human health and survival. What if we start to see things from another perspective? Our actions shall converge for instance to turn man-made environment like cities f…