0000000000048595
AUTHOR
Fabio Triolo
showing 23 related works from this author
Critical micellization density: A small-angle-scattering structural study of the monomer-aggregate transition of block copolymers in supercriticalCO2
2000
In this paper we report a small-angle neutron-scattering investigation of micelle formation by the fluorocarbon-hydrocarbon block copolymer, polyvinyl acetate-b-poly (1,1,2,2-tetrahydroperfluoro-octyl acrylate) in supercritical CO{sub 2} (scCO{sub 2}) at 313 K. At high pressure the copolymer is in a monomeric state with a random coil structure, while at low pressure the polymer forms spherical aggregates stable in a wide range of thermodynamic conditions. By profiling pressure, a sharp monomer-micelle transition is obtained due to the tuning of the solvating ability of scCO{sub 2}. We confirm the previous finding that this aggregate-monomer transition is driven by the gradual penetration of…
Modelling small angle neutron scattering data from polymers in supercritical fluids
2000
In this paper we report a SANS investigation of micelle formation by fluorocarbon-hydrocarbon block copolymers in supercritical CO2(scCO2) at 313K. A sharp unimer-micelle transition is obtained due to the tuning of the solvating ability of scCO2 by profiling pressure. At high pressure the copolymer is in a monomeric state with a random coil structure. By lowering the pressure aggregates are formed with the hydrocarbon segments forming the core and the fluorocarbon segments forming the corona of spherical aggregates. This aggregate-unimer transition is driven by the gradual penetration of CO2 molecules toward the core of the aggregate and is critically related to the density of the solvent, …
SAXS investigation on aggregation phenomena in supercritical CO2.
2004
Synchrotron Small-Angle X-Ray scattering (SAXS) measurements on aggregate formation of a Polyvinyl acetate- b-Perfluoro octyl acrylate (PVAc- b-PFOA) block copolymer in supercritical CO(2) are here reported. Experiments were carried out for a series of different thermodynamic conditions, changing the solvent density by profiling both the pressure at constant temperature and the temperature at constant pressure. This block copolymer and in general fluorocarbon-hydrocarbon di-blocks form aggregates depending on the value of CO(2) density. A sharp transition between monomers dissolved as random coils and micelles characterized by a solvophilic shell and a solvophobic core occurs when the CO(2)…
Organometallic complexes with biological molecules: XII. Solid-state and solution studies on dialkyltin(IV)- and trialkyltin(IV)-thiaminepyrophosphat…
1999
Dialkyltin(IV) and trialkyltin(IV) derivatives of the coenzyme thiaminepyrophosphate (H2TPP) have been synthesized with general formula R2Sn(HTPP)2·nH2O (Alk = Me, n = 2; Alk = Bu, n = 4) and R3SnHTPP·nH2O (R=Me, n = 2; R = Bu, n = 1), respectively. The solid-state structure of the complexes has been investigated through infrared and Mossbauer spectroscopy. The infrared data suggest the involvement of only phosphate oxygen atoms in the coordination of both dialkyl- and trialkyl-tin(IV) moieties, with phosphate anions behaving as monoanionic bidentate bridging or chelating groups, with the tin(IV) involved in six- and five-fold coordination geometries, respectively, in R2Sn(HTPP)2·nH2O (R = …
Industrial applications of the aggregation of block copolymers in supercritical CO 2 : a SANS study
2002
Industrial applications of supercritical carbon dioxide (scCO2) rely upon the rather selective and easily adjustable solvent ability of CO2. CO2 near the critical point is a poor solvent for high molecular weight (HMW) hydrocarbon polymers, while it is a very good solvent for amorphous fluorinated polymers. By increasing the pressure, CO2 becomes a good solvent even for HMW hydrogenated chains. Specially engineered amphiphilic di-block copolymers, with CO2-philic and CO2-phobic portions, are expected to undergo trough a monomer–aggregate transition when the solvent density of the scCO2 changes. Here small-angle neutron scattering (SANS) results are reported for a block copolymer dissolved i…
Biomarkers for vascular ageing in aorta tissues and blood samples.
2019
Abstract Objectives Functional and quantitative alterations and senescence of circulating and expanded endothelial progenitor cells (EPC), as well as systemic and tissue modifications of angiogenetic and inflammatory molecules, were evaluated for predicting age-related vessel wall remodeling, correlating them to intima media thickness (IMT) in the common carotid artery (CCA), a biomarker of early cardiovascular disease and aortic root dilation. Populations and methods A homogenous Caucasian population was included in the study, constituted by 160 healthy subjects (80 old subjects, mean age 72 ± 6.4, range 66–83 years; and 80 younger blood donors, mean age 26.2 ± 3.4, range 21–33 years), and…
Kinetics of block-copolymer aggregation in super critical CO2
2002
Small angle X-ray and neutron scattering (SAXS and SANS) are used to obtain structural information on the aggregation behavior of block-copolymers dissolved in supercritical CO2. The SANS technique is used to provide a detailed structural model for the micellar aggregates, which form below the critical micellization density (CMD), that we defined in our previous work. The SAXS technique (with a synchrotron source) is used to provide the first experimental information concerning the kinetic features of both formation and decomposition of such aggregates as soon as pressure jumps are applied to the solutions across the CMD. 2002 Elsevier Science B.V. All rights reserved.
Structure of diblock copolymers in supercritical carbon dioxide and critical micellization pressure
1999
This paper reports a small angle neutron scattering investigation of micelle formation by fluorocarbon-hydrocarbon block copolymers in supercritical ${\mathrm{CO}}_{2}{(\mathrm{s}\mathrm{c}\ensuremath{-}\mathrm{C}\mathrm{O}}_{2})$ at 65 \ifmmode^\circ\else\textdegree\fi{}C. A sharp unimer-micelle transition is obtained due to the tuning of the solvating ability of ${\mathrm{s}\mathrm{c}\ensuremath{-}\mathrm{C}\mathrm{O}}_{2}$ by profiling pressure, so that the block copolymer, in a semidilute solution, finds ${\mathrm{s}\mathrm{c}\ensuremath{-}\mathrm{C}\mathrm{O}}_{2}$ a good solvent at high pressure and a poor solvent at low pressure. At high pressure the copolymer is in a monomeric state…
Dilute and semi dilute solutions of block copolymers in water, near-critical and super-critical CO2: a small angle scattering study of the monomer–ag…
2002
Abstract Small angle neutron (SANS) and X-ray (SAXS) Scattering measurements on aggregate formation of block copolymers in water and in near-critical and supercritical CO2 are reported here. Time Resolved SAXS (TR-SAXS) has also been performed in the supercritical region. Experiments have been carried out for a series of different thermodynamic conditions, changing the solvent density by profiling the pressure at constant temperature. A sharp transition between monomers dissolved as random coils and micelles characterized by a solvo-philic shell and a solvo-phobic core occurs when the solvent density reaches the critical micellization value. This is easily shown in the case of scCO2.
Fractal approach in petrology: combining ultra small angle, small angle and intermediate angle neutron scattering
2000
Ultra small angle neutron scattering (USANS) instruments have recently covered the gap between the size resolution available with conventional intermediate angle neutron scattering and small angle neutron scattering (SANS) instruments on one side and optical microscopy on the other side. New fields of investigations are now open and important areas of material science (ceramics, glass fibers, natural materials) and fundamental physics (phase transition, phase separation and critical phenomena) can be studied in bulk samples with an accuracy previously unobtainable owing to a combination of favourable features of the neutron-matter interaction: high penetrability of neutrons, even cold neutr…
Toxic Effects of Organometallic Compounds towards Marine Biota
2002
Organometallic derivatives are compounds containing a direct σ or π carbon metal linkage. Furthermore, the concept of the metallic atom must be extended to all the elements that are less negative than the carbon atom. As a consequence, taking into account all elements that are less negative than carbon and the number of existing organic compounds, it is possible to synthesize millions of organometallic derivatives. Several of these are extensively used in organic syntheses; others may find application in agriculture and in many other fields as pesticides, fire retardants, wood preservatives, antifouling agents, etc. In general, the organic derivatives of the metals are more toxic than the p…
A Quality Risk Management Model Approach for Cell Therapy Manufacturing
2010
International regulatory authorities view risk management as an essential production need for the development of innovative, somatic cell-based therapies in regenerative medicine. The available risk management guidelines, however, provide little guidance on specific risk analysis approaches and procedures applicable in clinical cell therapy manufacturing. This raises a number of problems. Cell manufacturing is a poorly automated process, prone to operator-introduced variations, and affected by heterogeneity of the processed organs/tissues and lot-dependent variability of reagent (e.g., collagenase) efficiency. In this study, the principal challenges faced in a cell-based product manufacturi…
Small angle neutron scattering study of the quaternary structure of haemocyanin of Rapana thomasiana
1996
Abstract Small angle neutron scattering (SANS) experiments were performed on a series of solutions of haemocyanin (Hc) of Rapana thomasiana . In a first series of solutions, by changing the external contrast a model of the molecule that is apparently in disagreement with electron microscopy (EM) measurements was obtained. The apparent disagreement was resolved by performing experiments on a series of variable protein concentration solutions in D 2 O. The physical parameters of the model, extrapolated to zero concentration, are in excellent agreement with the EM results obtained on samples more dilute than those examined with SANS.
Echocardiographic Assessment of Ventricular Septal Rupture and Left Ventricular Aneurysm after Inferior and Posterior Myocardial Infarction
2018
We present a case of posterior ventricular septal rupture associated to left ventricular aneurysm manged, during peri-operative period, by transthoracic and transesophageal echocardiography. Three-dimensional transesophageal echocardiography findings add adjunctive and more accurate information regarding morphological details of the ventricular septal rupture rather than two-dimensional echocardiography, allowing, meanwhile, the detection of the outcome of the surgical repair.
Cardiovascular comorbidity in multiple sclerosis patients treated with mitoxantrone therapy: a cohort study
2017
Abstract Background Mitoxantrone (MX) has been used as second line therapy for aggressive multiple sclerosis (MS). Potential cardiotoxic effects of MX limit its use; a cumulative dose of up to 100 mg/m2, has been long considered relatively safe. We calculated the frequency of cardiac side effects in MS patients treated with MX. Methods We performed a cohort study including all MS patients treated with MX at the Neurological Department of the University Hospital of Palermo, Italy. Two hundred-sixty-four MS patients diagnosed according to validated criteria were included and followed-up until the end of September 2010. Patients were treated with MX as a second line therapy if they had no prev…
Critical Micelle Density for the Self-Assembly of Block Copolymer Surfactants in Supercritical Carbon Dioxide
1999
The parameters which influence the self-assembly of molecules in solution include the temperature and solvent quality, and this study illustrates the use of these variables to regulate the degree of association of block copolymer amphiphiles in highly compressible supercritical carbon dioxide. Small-angle neutron scattering (SANS) has been used to examine the association behavior of a block copolymer containing a CO2-phobic moiety, poly(vinyl acetate), and a CO2-philic block, poly(1,1-dihydroperfluoro-octylacrylate). By adjustment of the density of the medium through pressure and temperature profiling, the self-assembly can be reversibly controlled from unimers to core−shell spherical micel…
Dietary strategy for prevention and management of dyslipidemia: international guidelines
2012
Primary prevention of cardiovascular disease should begin with a detailed metabolic study of our patients who must follow a nutritional therapy. Recently, new guidelines ESC/EAS 2011 on the treatment of dyslipidemia have been drawn up, according to which it is possible to arrive at desirable values of cholesterol and triglycerides with a synergy between drug treatment and adequate diet therapy. At this time, Mediterranean diet has been undergoing a radical transformation: there is hyperalimentation of the Mediterranean diet in all its components. The effectiveness of the Mediterranean diet on the reduction of lipids has been demonstrated, and the problem is how to implement this diet in the…
Fractal approach in petrology: Combining ultra small angle (USANS), and small angle neutron scattering (SANS)
2000
Ultra small angle neutron scattering instruments have recently covered the gap between the size resolution available with conventional intermediate angle neutron scattering and small angle neutron scattering instruments on one side and optical microscopy on the other side. Rocks showing fractal behavior in over two decades of momentum transfer and seven orders of magnitude of intensity are examined and fractal parameters are extracted from the combined USANS and SANS curves.
Organometallic complexes with biological molecules. XIV. Biological activity of dialkyl and trialkyltin(IV) [meso-tetra(4-carboxy- phenyl)porphinate]…
2000
Molecules. XIV. Biological Activity of Dialkyl and Trialkyltin(IV) [Meso-tetra(4-carboxyphenyl)porphinate] Derivatives C. Mansueto, E. Puccia, F. Maggio, R. Di Stefano, T. Fiore, C. Pellerito, F. Triolo and L. Pellerito* Dipartimento di Biologia Animale, Universita di Palermo, Via Archirafi 18, 90123 Palermo, Italy Dipartimento di Chimica Inorganica, Universita di Palermo, Viale delle Scienze, Parco d’Orleans, 90128 Palermo, Italy
Critical micellisation density: a SAS structural study of the unimer–aggregate transition of block-copolymers in supercritical CO2
2000
In this paper we report a SANS investigation of micelle formation by fluorocarbon-hydrocarbon block copolymers in supercritical CO2 (scCO2) at 313K. A sharp unimer-micelle transition is obtained due to the tuning of the solvating ability of scCO2 by profiling pressure. At high pressure the copolymer is in a monomeric state with a random coil structure. By lowering the pressure aggregates are formed with the hydrocarbon segments forming the core and the fluorocarbon segments forming the corona of spherical aggregates. This aggregateunimer transition is driven by the gradual penetration of CO2 molecules toward the core of the aggregate and is critically related to the density of the solvent, …
Organometallic complexes with biological molecules: XIII. Organotin(IV)[meso-tetra (4-carboxyphenyl)porphinate]s and the cell cycle: a flow-cytometri…
1999
The cytotoxic derivatives diorganotin(IV) and triorganotin(IV) [meso-tetra(4-carboxyphenyl)porphinates, with stoichiometries [R2Sn]2TPPC and [R3Sn]4TPPC [R = Me, Bu, Ph; TPPC4−= meso-tetra(4-carboxyphenyl)porphinate4−], namely bis[dimethyltin(IV)], bis[dibutyltin(IV)], bis[diphenyltin(IV)], tetra[trimethyltin(IV)], tetra[tributyltin(IV)] and tetra[triphenyltin(IV)] [meso-tetra(4-carboxyphenyl)porphinate]s, have been used to investigate their effects on the cultured human kidney cell cycle in order to understand further the origin of cell-growth inhibition induced by the above-mentioned chemicals. The cell-cycle-dependent DNA content distribution of cultured cells exposed to these compounds…
Organometallic complexes with biological molecules. XV. Effects of tributyltin(IV)chloride on enzyme activity, Ca2+, and biomolecule and synthesis in…
2001
Considerable attention has been given in recent years to the possibility that xenobiotics in the environment may affect reproduction in animals. In this study, the relative impact of tributyltin(IV) (TBT) chloride, one of the most toxic environmental pollutants, was investigated using Ciona intestinalis ovary as a model system. The pleiotropic effects of TBT exposure are concentration dependent and include a decrease of ATP levels, lipid content and nucleic acid content and synthesis. In contrast, a marked increase in calcium (Ca2+) and glucose content is observed. Furthermore, TBT alters enzymatic activity, inhibiting creatine kinase and stimulating alkaline phosphatase and cholinesterase …
A combined small-angle neutron and X-ray scattering study of block copolymers micellisation in supercritical carbon dioxide
2003
Small angle neutron and X-ray scattering (SANS and SAXS) are used to investigate the monomer–aggregate transition of fluorocarbon–hydrocarbon diblock copolymers in supercritical carbon dioxide. SANS data are analyzed using a polydisperse sphere core–shell model. Synchrotron SAXS data have been collected by profiling the pressure at different temperatures, and critical micellization densities have been obtained for a series of diblock solutions. Finally pressure jump experiments, combined with synchrotron SAXS, have revealed two steps in the dynamics of the formation of the aggregates.