Dehydration of Fructose to 5-HMF over Acidic TiO2 Catalysts

Different solid sulfonic titania-based catalysts were investigated for the hydrothermal dehydration of fructose to 5-hydroxymethylfurfural (5-HMF). The catalytic behavior of the materials was evaluated in terms of fructose conversion and selectivity to 5-HMF. The surface and structural properties of the catalysts were investigated by means of X-ray diffraction (XRD), N2 adsorption isotherms, thermo-gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and acid capacity measurements. Special attention was focused on the reaction conditions, both in terms of 5-HMF selectivity and the sustainability of the process, choosing water as the solvent. Among the various process condition…

Polyaminocyclodextrin nanosponges: synthesis, characterization and pH-responsive sequestration abilities

New pH-responsive nanosponges were obtained by reacting four different polyaminocyclodextrins with heptakis-(6-bromo)-(6-deoxy)-β-cyclodextrin. The materials obtained were characterized by various techniques (FT-IR, potentiometric titration, differential scanning calorimetry (DSC), porosimetry (BET), 13C{1H} CP-MAS NMR). Their adsorption abilities at different pH values were verified towards a suitable set of model guests, and seem mainly controlled by electrostatic interactions, as a function of the protonation/charge status of the polymer matrix. By contrast, data positively point out a lesser importance assumed by the induced-fit effect, important in affecting the formation of host–guest…

Thyroid Cancer in the Pediatric Age in Sicily: Influence of the Volcanic Environment.

Background/Aim: Pediatric thyroid cancer (TC) is rare but its incidence is increasing. We analyzed incidence and characteristics of pediatric TC in Sicily and comparatively evaluated data from the volcanic and non-volcanic areas. Materials and Methods: All incident pediatric (0-19 years) TCs in Sicily between 2002-2009 were analyzed for the area of residence and compared to data for adults. Results: A total of 54 differentiated TCs (DTC) and nine medullary TCs were diagnosed in Sicily in children between 2002-2009. DTC age standardized rate for the world population (ASRw) was 0.8/105 in females and 0.2/105 in males, with a higher incidence in the volcanic area (ASRw=1.4/105 in females, 0.5/…

Pre- and post-modification of mixed cyclodextrin-calixarene co-polymers: A route towards tunability

Various pre-modified and post-modified cyclodextrin-calixarene hyper-reticulated co-polymers were synthesized, fully characterized by different techniques (FT-IR, 13C{1H} CP-MAS and LGFS solid-state NMR, thermogravimetry, porosimetry), and tested to assess their absorption abilities as nanosponges. The construction of the polymer network was accomplished exploiting the well-known CuAAC reaction between two different heptakis-6-azido-β-cyclodextrins and two different propargyloxy-calix[4]arenes. Post-modification was aimed to achieve the presence of ionizable (acidic or basic) groups on the polymer framework. Sequestration tests towards two model pollutant molecules surprisingly showed that …

Synthesis, characterization and antimicrobial activity of polyaminocyclodextrin-capped Ag Nanoparticles

Biocompatible Ag nanocomposites were prepared by photoreduction of ammoniacal silver acetate in the presence of a polyaminocyclodextrin, namely the poly-{6-[3-(2-(3-aminopropylamino)-ethylamino)-propylamino]}-(6-deoxy)-b-CD (amCD, figure 1). The obtained Ag-amCD systems, which possess an oniontype structure [1] with a metal core surrounded by several layers of the capping agent, were characterized by means of various complementary techniques. In particular, FT-IR spectroscopy confirmed the presence of the amCD scaffold in the composite, and evidenced a partial oxidative degradation of the polyamine branches,due to the fact that these groups function as sacrificial reducing agents in the pho…

Attivita’ sinergica di nanoparticelle di argento fotosintetizzate con antibatterici classici

Synergistic activity of photo-synthesized silver nanoparticles with classic antibacterials

Chronic headache and body mass index: a case-control study.

In recent years clinical research has focused on the possible role played by obesity as a risk factor for headache chronification.The aim of this case-control, hospital-based study was to evaluate: the prevalence of overweight and obesity in subjects with chronic migraine (CM) and chronic tension-type headache (CTTH); and the possible correlations between body mass index (BMI) and both headache types. Materials and methods: We studied 79 patients, 46 with CM and 33 with CTTH, consecutively referred to the Adult Headache Centre of the University of Palermo (A.H. Study) between 2007 and 2009, and 316 controls without headache (each patient was matched by sex and age to four controls).The head…

Effect of pH Variations on the Properties of Cyclodextrin‐Calixarene Nanosponges

The pH-responsive properties of cyclodextrin-calixarene nanosponge co-polymeric materials have been investigated. In particular, ISE-H+ potentiometric titrations were carried out in order to evaluate the acid-base properties and the actual amount of ionizable sites present in the materials. Moreover, the relevant pH-dependent adsorption abilities were evaluated towards a set of selected model organic pollutant molecules by means of adsorption tests and by studying the corresponding adsorption isotherms. The latter ones could be suitably described by means of the Freundlich model. The whole of the experimental results enabled us to clarify some general aspects of the microscopic behavior of …

Prevalence of tension-type headache in adult general population: the PACE study and review of the literature

The mean global prevalence of tension-type headache (TTH) in adult is 42 %. To date, there have been no Italian studies on TTH prevalence in the adult general population. Therefore, we conducted a cross-sectional study, called PACE (PArma CEfalea, or "Headache in Parma"), aimed at detecting the prevalence and clinical features of primary headaches in the city of Parma's adult general population. Crude past-year prevalence for definite TTH was 19.4 % (95 % CI 16.8-21.9), namely 9.0 % (95 % CI 7.1-10.8) for infrequent TTH, 9.8 % (95 % CI 7.9-11.8) for frequent TTH, and 0.6 % (95 % CI 0.1-1) for chronic TTH. Crude prevalence for probable TTH was 2.3 % (95 % CI 1.3-3.3). Our study results indic…

Synergistic Activity of Silver Nanoparticles and Polyaminocyclodextrins in Nanosponge Architectures

Four new composite materials, formed by silver nanoparticles embedded in polyamino-cyclodextrin nanosponge architectures, were designed exploiting the affinity of polyamino-cyclodextrins towards Ag+ ions. These materials were characterized by means of different techniques (thermogravimetry, FT-IR, solid state NMR, SEM, HR-TEM), and tested as catalysts for the reduction of nitroarenes and the oxidative coupling of anilines. The results obtained showed synergistic activity between the supramolecular binding abilities of the nanosponge matrix and the catalytic properties of the metal nanoparticle, and open the way towards the design of new composite smart nanomaterials with improved catalytic …

Polyaminoazide mixtures for the synthesis of pH-responsive calixarene nanosponges

Two mixtures of polyaminoazides were synthesized by a nucleophilic displacement strategy providing no separation of the components. The mixtures were adequately characterized by means of combined HR-ESIMS, FTIR and NMR techniques and, despite their complexity, they were successfully used to accomplish the subsequent preparation of pH-sensitive calixarene hyper-reticulated nanosponge materials. The desired responsivity to pH variations of the nanosponges obtained was verified by means of absorption tests on a set of organic pollutant model molecules.

Photosynthesized silver-polyaminocyclodextrin nanocomposites as promising antibacterial agents with improved activity

Ag nanocomposites were prepared by photoreduction of ammoniacal silver acetate in the presence of poly-{6-[3-(2-(3-aminopropylamino)ethylamino)propylamino]}-(6-deoxy)-β-CD (amCD). The obtained systems were characterized by means of various complementary techniques (UV-vis, FT-IR, TEM, SAED). In particular, FT-IR spectroscopy evidenced a partial oxidative degradation of the polyamine branches of the capping auxiliary, due to the fact that these groups function as a sacrificial reducing agent in the photoinduced formation of the Ag metal core. TEM and SAED micrographs showed that the Ag cores possess a relatively low polydispersity and a significantly crystalline character. The Ag–amCD system…

Catalytic properties of Ag-PolyaminoβCD NPs for reduction of nitroarenes

The reduction of nitroarenes is a key reaction involved in the synthesis of several compounds such as drugs, pesticides or dyes. During the last years Pd and Ag NPs have been used as catalysts to carry out this reaction with NaBH4. However several mechanistic aspects of the process are still unclear; in particular there is not agreement about the kinetic order of these reactions, whether 0-th or 1-st order in the substrate[1]. The aim of this work is to use a novel catalytic systems constituted by Ag-NPs coated with different polyamino-βCDs (Figure 1)[2], to carry out the reduction of some aromatic nitrocompounds using NaBH4 as the reducing agent, and to determine the kinetic features of th…

Age of onset of episodic and chronic cluster headache – a review of a large case series from a single headache centre

Background In the largest case series of cluster headache (CH) published in the literature, age of onset varies between 29.6 and 31.6 years. Differences in onset age based on gender and subtype diagnosis are reported, while there are only few data on patients with childhood and elderly onset. We therefore deemed it useful to review our own large case series of CH patients. Methods The age of onset of cluster headache was investigated in a consecutive case series of 808 patients (585 men and 223 women), including 686 (503 men and 183 women) with episodic cluster headache (ECH), 103 (66 men and 37 women) with chronic cluster headache (CCH), and 19 with an indeterminate form of CH (16 men and …

Increased thyroid cancer incidence in a basaltic volcanic area is associated with non-anthropogenic pollution and biocontamination

The increased thyroid cancer incidence in volcanic areas suggests an environmental effect of volcanic-originated carcinogens. To address this problem, we evaluated environmental pollution and biocontamination in a volcanic area of Sicily with increased thyroid cancer incidence. Thyroid cancer epidemiology was obtained from the Sicilian Regional Registry for Thyroid Cancer. Twenty-seven trace elements were measured by quadrupole mass spectrometry in the drinking water and lichens (to characterize environmental pollution) and in the urine of residents (to identify biocontamination) in the Mt. Etna volcanic area and in adjacent control areas. Thyroid cancer incidence was 18.5 and 9.6/10(5) inh…

Binding abilities of a chiral calix[4]resorcinarene: a polarimetric investigation on a complex case of study

Polarimetry was used to investigate the binding abilities of a chiral calix[4]resorcinarene derivative, bearing L-proline subunits, towards a set of suitably selected organic guests. The simultaneous formation of 1:1 and 2:1 host–guest inclusion complexes was observed in several cases, depending on both the charge status of the host and the structure of the guest. Thus, the use of the polarimetric method was thoroughly revisited, in order to keep into account the occurrence of multiple equilibria. Our data indicate that the stability of the host–guest complexes is affected by an interplay between Coulomb interactions, π–π interactions, desolvation effects and entropy-unfavorable conformatio…

Descriptive Epidemiology of Human Thyroid Cancer: Experience From a Regional Registry and The “Volcanic Factor”

Thyroid cancer (TC), the most common endocrine tumor, has steadily increased worldwide due to the increase of the papillary histotype. The reasons for this spread have not been established. In addition to more sensitive thyroid nodule screening, the effect of environmental factors cannot be excluded. Because high incidences of TC were found in volcanic areas (Hawaii and Iceland), a volcanic environment may play a role in the pathogenesis of TC.In January 2002, the Regional Register for Thyroid Cancer was instituted in Sicily. With a population of approximately 5 million inhabitants with similar genetic and lifestyle features, the coexistence in Sicily of rural, urban, industrial, moderate-t…

Formazione di complessi di inclusione della beta-ciclodestrina. Una dimostrazione colorimetrica

Mitotane Concentrations Influence Outcome in Patients With Advanced Adrenocortical Carcinoma

Mitotane is the main option of treatment for advanced adrenocortical carcinoma (ACC). However, limited evidence is available regarding the impact of plasma mitotane levels on patient outcome. To address this question, we retrospectively analyzed patients with advanced ACC treated with mitotane for &ge

Anxiety disorder, depression and chronic daily headache: a case-control study.

Chronic headache cause high disability in sufferers and high social cost. Data regarding possible comorbid diseases, manly depression and anxiety, are still few and conflicting.The aim of this case-control, hospital-based study was: to evaluate the prevalence of depression and anxiety in subjects with chronic migraine (CM) and chronic tension-type headache (CTTH); and to compare the results with those found in a control group without headache. Materials and methods We studied 79 patients, 46 with CM and 33 with CTTH, consecutively referred to the Adult Headache Centre of the University of Palermo (A.H. Study) between 2007 and 2009, and 316 controls without headache (each patient was matched…

Silver nanoparticles stabilized by a polyaminocyclodextrin as catalysts for the reduction of nitroaromatic compounds

Abstract Silver nanoparticles stabilized by means of poly -(6- N , N -dimethyl-propylenediamino)-(6-deoxy)-β-cyclodextrin were synthesized, characterized by different techniques (UV–vis spectroscopy, Dynamic Light Scattering, High Resolution Transmission Electron Microscopy, Fourier-transform IR Spectroscopy) and used as catalysts for the reduction of various nitrobenzene derivatives with sodium borohydride. The nanocomposites obtained appear to have an organized structure, with a metal core surrounded by a layer-structured coating shell. Kinetic data, rationalized in terms of a modified Langmuir–Hinshelwood model, evidenced a non-linear dependence of the reaction rate on the concentration …

Binding properties of polyaminocyclodextrin materials towards polyanions and p-nitroaniline derivatives

PROPERTIES AND APPLICATIONS OF POLYAMINOCYCLODEXTRIN DERIVATIVES

Nel presente lavoro sono state prese in esame le potenziali applicazioni delle poliamminociclodestrine. In particolare, diversi derivati poliamminociclodestrinici (amCD) sono stati ottenuti utilizzando un approccio sintetico diretto, tramite reazione di sostituzione nucleofila tra la heptakis-(6-deossi)-(6-bromo)-βCD (BrβCD) e poliammine lineari. Una volta effettuata l’opportuna caratterizzazione NMR, ESI-MS e potenziometrica, sono state investigate diverse possibili utilizzazioni di tali materiali. Anzitutto, sono state valutate le capacità di dare complessi di inclusione host-guest con diversi derivati organici sia delle amCD libere che di materiali costituiti da nanospugne a base di amCD…

Photochemical preparation of polyaminocyclodextrin-capped silver nanocomposites: mechanistic insights

Photoreduction of silver salts in the presence of three polyaminocyclodextrin derivatives (AmCD, Figure 1) constitutes a simple and straightforward route to obtain stable Ag nanoparticles. These systems have been suitably characterized (UV-vis, FT-IR, TEM, Figure 2) and tested for their antimicrobial activity.1 We observed that Ag photoreduction is effectively induced by irradiation with green light (513 nm); however, best performances are achieved with the use of a light source having at the same time a significant emission in the near-infrared (NIR) region. On the grounds of analytical and kinetic evidences, we hypothesized a multi-step mechanism for nanoparticle formation. In particular,…

Hyper-reticulated calixarene polymers: a new example of entirely synthetic nanosponge materials

New calixarene-based nanosponges (CaNSs), i.e., hyper-reticulated polymers constituted by calixarene monomer units joined by means of bis(1,2,3-trialzolyl)alkyl linkers, were synthesized, characterized and subjected to preliminary tests to assess their supramolecular absorption abilities towards a set of suitable organic guests, selected as pollutant models. The synthesis was accomplished by means of a CuAAC reaction between a tetrakis(propargyloxy)calix[4]arene and an alkyl diazide. The formation of the polymeric network was assessed by means of FTIR and 13C{1H} CP-MAS solid-state NMR techniques, whereas morphological characterization was provided by SEM microghaphy. The materials were pro…

Convenient Photochemical Synthesis of Silver-Polyaminocyclodextrin Nanocomposites: The Role of the Light Source from a Mechanistic Viewpoint

An investigation on the light-driven reduction of the [Ag(NH3)2]+complex in the presence of polyaminocyclodextrins was carried out, in order to clarify the mechanism of the process. The role of the organic auxiliary as both the sacrificial reductant and the capping agent was positively assessed. Moreover, particular attention was paid to the role of the irradiation source. Experimental results indicate that a complex mechanism is involved in the formation of the nanocomposite, with a primary photoinduced single-electron-transfer process promoted by irradiation with green light, followed by a secondary chemical reduction process activated by NIR. Representative composites were characterized …

The PACE study: past-year prevalence of tension-type headache and its subtypes in Parma's adult general population.

The mean global prevalence of tension-type headache (TTH) in adult is 42 %. To date, there have been no Italian studies on TTH prevalence in the adult general population. Therefore, we conducted a cross-sectional study, called PACE, aimed at detecting the prevalence of primary headaches in the city of Parma's adult general population. 904 subjects representative of Parma's adult general population were interviewed face to face by a physician of our Headache Centre. Crude past-year prevalence for definite TTH was 19.4 % (95 % CI 16.8-21.9; 18.4 %, 95 % CI 14.6-22.3 in men, and 20.1 %, 95 % CI 16.6-23.6 in women), namely, 9.0 % (95 % CI 7.1-10.8) for infrequent TTH, 9.8 % (95 % CI 7.9-11.8) f…

The PACE study: Past-year prevalence of migraine in Parma's adult general population

Background: In the literature there are few data about the prevalence of primary headaches, including migraine, in the Italian general population. The PACE study (PArma CEfalea, or ‘Headache in Parma’) is an observational study aimed at detecting the prevalence and clinical features of primary headaches in the city of Parma’s adult general population. Materials and methods: A total of 904 subjects representative of Parma’s adult general population were interviewed face-to-face by a physician from the Parma Headache Centre. They were given a specially designed and validated questionnaire for the diagnosis of primary headaches according to the ICHD-II criteria. Results: Past-year adjusted pr…

Binding abilities of polyaminocyclodextrins: polarimetric investigations and biological assays.

Three polyaminocyclodextrin materials, obtained by direct reaction between heptakis(6-deoxy-6-iodo)-β-cyclodextrin and the proper linear polyamines, were investigated for their binding properties, in order to assess their potential applications in biological systems, such as vectors for simultaneous drug and gene cellular uptake or alternatively for the protection of macromolecules. In particular, we exploited polarimetry to test their interaction with some model p-nitroaniline derivatives, chosen as probe guests. The data obtained indicate that binding inside the host cavity is mainly affected by interplay between Coulomb interactions and conformational restraints. Moreover, simultaneous i…

Nanoparticelle di Ag-poliamminoCD come catalizzatori per la riduzione di nitrocomposti aromatici

Sistemi nanoparticellari di Argento protetti con poliammino-beta-ciclodestrine sono stati preparati, caratterizzati, e impiegati come catalizzatori per la riduzione con boroidruro di sodio di una serie di nitrocomposti aromatici modello 1-8. Tale reazione costituisce una interessante alternativa rispetto ai metodi di riduzione più comuni (LiAlH4, Zn/HCl), che prevedono l’uso di condizioni di reazione piuttosto drastiche. La cinetica della reazione considerata è stata approfonditamente studiata al fine di chiarire il ruolo meccanicistico del catalizzatore. E’ stato trovato, infatti, che il processo risulta di ordine misto rispetto al substrato, e che le costanti cinetiche apparenti di reazio…

Scienza inForma. La Forma nella Scienza

SPAIS 2017 si propone di approfondire l’analisi dell’importanza della forma in vari campi del sapere scientifico: dalla forma delle molecole in relazione alle loro proprietà, gli aggregati supramolecolari e, via via su scale dimensionali sempre più grandi, alla forma degli organismi, della Terra e dell’Universo. Come sempre proporrà anche stimolanti “contaminazioni” fra Scienze, Storia, Filosofia e Arte.

I Modelli nelle Scienze

Il volume raccoglie i contributi presentati in occasione della XIII edizione della Scuola Permanente per l’Aggiornamento degli Insegnanti di Scienze Sperimentali - SPAIS, Agrigento, 22 – 27 Luglio 2019. Il tema riguardante i modelli scientifici è di particolare interesse in tutte le Scienze e particolare attenzione è stata rivolta ad argomenti di carattere interdisciplinare.