458 research outputs found

    Wo3 and ionic liquids: A synergic pair for pollutant gas sensing and desulfurization

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    This review deals with the notable results obtained by the synergy between ionic liquids (ILs) and WO3 in the field of pollutant gas sensing and sulfur removal pretreatment of fuels. Starting from the known characteristics of tungsten trioxide as catalytic material, many authors have proposed the use of ionic liquids in order to both direct WO3 production towards controllable nanostructures (nanorods, nanospheres, etc.) and to modify the metal oxide structure (incorporating ILs) in order to increase the gas adsorption ability and, thus, the catalytic efficiency. Moreover, ionic liquids are able to highly disperse WO3 in composites, thus enhancing the contact surface and the catalytic ability of WO3 in both hydrodesulfurization (HDS) and oxidative desulfurization (ODS) of liquid fuels. In particular, the use of ILs in composite synthesis can direct the hydrogenation process (HDS) towards sulfur compounds rather than towards olefins, thus preserving the octane number of the fuel while highly reducing the sulfur content and, thus, the possibility of air pollution with sulfur oxides. A similar performance enhancement was obtained in ODS, where the high dispersion of WO3 (due to the use of ILs during the synthesis) allows for noteworthy results at very low temperatures (50â—¦ C)

    DBS-Based Eutectogels: Organized Vessels to Perform the Michael Addition Reaction**

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    Supramolecular eutectogels were obtained from the gelation of 1,3 : 2,4-dibenzylidene-D-sorbitol (DBS) in cholinium chloride-based deep eutectic solvents (DES), differing for the nature of the hydrogen bond donor. Ethylene glycol, diethylene glycol, triethylene glycol, glycerol and urea were tested. Soft materials were fully characterized, determining critical gelation concentration, gel-sol transition temperatures and mechanical properties. Furthermore, to have information about the organization of the gelator in the tridimensional network, resonance light scattering, circular dichroism and microscopy investigations were performed. Eutectogels were used as organized “vessels” to perform the L-proline catalyzed Michael addition reaction. The probe reaction was carried out in gel phase and in DES solution. Data collected shed light on the effect that gel microenvironment exerts on the outcome of the reaction. In general, gel phases allowed having comparable or even better results than the ones collected in DES solution, with better results obtained in soft materials with the highest organization, as accounted for by the presence of larger aggregates and the occurrence of stronger intermolecular interactions. In turn, this accounts also for the effect of substrates structure that indicates that better yields could be obtained in the presence of more flexible nucleophile and dienones, having more extended π-surface

    Aspetti dell'alimentazione di alcune specie di selaci del Canale di Sicilia

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    I Selaci occupano gli ultimi livelli delle reti trofiche marine: si tratta infatti di carnivori che, spesso, predano risorse utili anche all'uomo. Numerose specie demersali (squali, razze e torpedini) si alimentano, infatti, con organismi di interesse commerciale come Aristeidi, Peneidi, Cefalopodi e Pesci ossei. Le abitudini alimentari dei Selaci demersali del Canale di Sicilia sono quasi completamente sc onosciute; esistono in letteratura i lavori di Capapé relativi alle acque tunisine, che si limitano ad una descrizione puramente qualitativa delle diete ma che hanno tuttavia evidenziato preferenze verso Crostacei Decapodi, Cefalopodi e Teleostei. Lo studio dei contenuti stomacali dei Selaci può fornire dunque elementi utili alla comprensione delle reti trofiche demersali, all'indagine sull'esistenza di competizione tra le diverse specie e allo studio dell'interferenza con prede di valore commerciale

    A Behavior-Based Intrusion Detection System Using Ensemble Learning Techniques

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    Intrusion Detection Systems (IDSs) play a key role in modern ICT security. Attacks detected and reported by IDSs are often analyzed by administrators who are tasked with countering the attack and minimizing its damage. Consequently, it is important that the alerts generated by the IDS are as detailed as possible. In this paper, we present a multi-layered behavior-based IDS using ensemble learning techniques for the classification of network attacks. Three widely adopted and appreciated models, i.e., Decision Trees, Random Forests, and Artificial Neural Networks, have been chosen to build the ensemble. To reduce the system response time, our solution is designed to immediately filter out traffic detected as benign without further analysis, while suspicious events are investigated to achieve a more fine-grained classification. Experimental evaluation performed on the CIC-IDS2017 public dataset shows that the system is able to detect nine categories of attacks with high performances, according to all the considered metrics

    Insights about the ability of folate based supramolecular gels to act as targeted therapeutic agents

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    With the aim to obtain targeted chemotherapeutic agents, imidazolium and ammonium-based folate salts were synthesized. Their photophysical behavior was investigated both in buffer and buffer/DMSO solution as well as in solid phase, performing UV-vis and fluorescence investigations. Properties of the aggregates were also analyzed by dynamic light scattering. Gelation ability of the salts was analyzed in biocompatible solvents, and gel phases obtained were characterized by determining critical gelation concentrations and gel-solution transition temperatures. Insights about gelator interactions in the tridimensional network were also gained performing ATR-FTIR investigation. Properties of soft materials were further analyzed performing rheology measurements, scanning electron microscopy, fluorescence and resonance light scattering investigations. Antiproliferative activity of organic salts was tested towards two breast cancer cell lines, expressing different levels of folate receptor, namely MDA-MB-231 and MCF-7, and a normal epithelial cell line, like h-TER T-RPE-1, by using MTT assay. Dichlodihydrofluorescein acetate test was performed to verify the role of oxidative stress in cell death. Finally, antiproliferative activity was also evaluated in gel phase, to verify if salts were able to retain biological activity also after the entrapment in the gelatinous network. Results collected evidence that folate based organic salts were able to behave as targeted chemotherapeutic agents both in solution and gel phase, showing uptake mechanism and selectivity indexes that depend on both cancer cell line nature and salt structure

    Hybrid supramolecular gels of Fmoc-F/halloysite nanotubes: systems for sustained release of camptothecin

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    Supramolecular gel hybrids obtained by self-assembly of Fmoc-L-phenylalanine (Fmoc-F) in the presence of functionalized halloysite nanotubes (f-HNT) were obtained in biocompatible solvents and employed as carriers for the delivery of camptothecin (CPT) molecules. The synthesis of the new f-HNT material as well as its characterization are described. The properties of the hybrid hydrogels and organogels were analyzed by several techniques. The presence of small amounts of f-HNT allows good dispersion of the tubes and the subsequent formation of homogeneous gels. The experimental results show that f-HNT functions only as an additive in the hybrid gels and does not demonstrate gelator behavior. The in vitro kinetic release from both f-HNT/CPT and Fmoc-F/f-HNT/CPT was studied in media that imitates physiological conditions, and the factors controlling the release process were determined and discussed. Furthermore, the antiproliferative in vitro activities of the gels were evaluated towards human cervical cancer HeLa cells. A comparison of data collected in both systems shows the synergistic action of f-HNT and the gel matrix in controlling the release of CPT in the media and maintaining the drug in its active form. Finally, a comparison with pristine HNT is also reported. This study suggests a suitable strategy to obtain two-component gel hybrids based on nanocarriers with controlled drug carrier capacity for biomedical applications

    Left ventricular (LV) pacing in newborns and infants. Echo assessment of LV systolic function and synchrony at 5-year follow-up

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    Background: Small retrospective studies reported that left ventricular (LV) pacing is likely to preserve LV function in children with isolated congenital complete atrioventricular block (CCAVB). The aim of this study was to prospectively evaluate LV contractility and synchrony in a cohort of neonates/infants at pacemaker implantation and follow-up. Methods: Patients with CCAVB who underwent LV pacing were evaluated with electrocardiogram and echocardiogram in a single-center, prospective study. Data were collected at implantation, at 1-month and every year of follow-up, up to 5 years. LV ventricular dimensions (diameters and volumes), systolic function (ejection fraction [EF] and global longitudinal strain [GLS]), and synchrony were evaluated. Data are reported as median (25th-75th centiles). Results: Twenty consecutive patients with CCAVB underwent pacemaker implantation (12 single-chamber pacemaker [VVIR] and eight dual-chamber pacemaker [DDD]) with epicardial leads: 17 on the LV apex and three on the free wall. Age at implantation was 0.3 months (1 day-4.5 months). Patients showed good clinical status, normal LV dimensions, preserved systolic function, and synchrony at 60 (30-60) months follow-up. EF increased to normal values in patients with preimplantation EF <50%. Presence of antibodies and pacing mode (DDD vs VVIR) had no impact on the outcome. Conclusions: LV pacing preserved LV systolic function and synchrony in neonates and infants with CCAVB at 5-year follow-up. LV EF improved in patients with low preimplantation EF. Pacing mode or the presence of autoantibodies did not demonstrated an impact on LV contractility and synchrony

    Microplastics impair the feeding performance of a Mediterranean habitat-forming coral

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    none9siThe impact of plastic debris, and in particular of microplastics (here referred as particles smaller than 5 mm) on aquatic environments has now become a topic of raising concern. Microplastics are particularly abundant in the Mediterranean Sea, potentially exerting substantial pressures on marine organisms at different levels of organization. Ingestion of microplastics has been observed in a large number of marine species. The aim of this work is to test if microplastics produce a feeding impairment in Astroides calycularis, a shallow water, habitat-forming coral endemic to the Mediterranean Sea. Our findings suggest a lack of any avoidance mechanism allowing the polyps to discern between food items and microplastics when occurring simultaneously. Moreover, polyps spend a considerable amount of time on handling microplastic particles. As a consequence, microplastics impair the feeding efficiency in A. calycularis, since polyps may not be fully able to profit from the drifting plankton aggregations. Therefore, we suggest that microplastics can cause a reduction of fitness in A. calycularis, and presumably also in other species characterized by suspension feeding strategy.embargoed_20220123Savinelli B.; Vega Fernandez T.; Galasso N.M.; D'Anna G.; Pipitone C.; Prada F.; Zenone A.; Badalamenti F.; Musco L.Savinelli, B.; Vega Fernandez, T.; Galasso, N. M.; D'Anna, G.; Pipitone, C.; Prada, F.; Zenone, A.; Badalamenti, F.; Musco, L

    Evaluation of frameworks of analysis employed in studies of exclusion zones

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    The purpose of this Work Package is to examine the various approaches to analysing fishery exclusion zones (FEZs) and to identify the circumstances in which one approach might be preferred to another. Our concern here is not so much with answering questions about exclusion zones - these being dealt with in later Work Packages - as with articulating the questions themselves and in understanding how in principle they could be addressed. An important theme is the precision with which questions need to be answered, since this will determine the type of information collected and how such information is analysed. The question ' is an exclusion zone likely to improve the condition of this fishery ?' is less precise and less demanding of data than the question ' by how much will an exclusion zone improve this fishery ?' since it could in principle be answered by expert judgement rather than quantitative analysis. In practice fisheries managers may be confronted with situations where decisions have to be made quickly, and qualitative answers may be the only thing possible in circumstances where data cannot be obtained in the available time. The Work Package will look at FEZs from a number of different perspectives, but its dominant concern is with the information – principally in the form of socio-economic and biological indicators - needed by fisheries managers in order to evaluate the effectiveness of FEZs. To contextualise the discussion we start by outlining a paradigm for understanding the linkages between human activities and the environment, showing how it can be applied to fisheries and marine resources. The Work Package then considers the substantive information requirements of fisheries managers, commencing with socio-economic assessment and moving on to a review of biological assessment and the progress which has been made in the development of mathematical models of FEZs. Bio-economic modelling, which is essentially a specialised type of socio-economic assessment in which explicit account is taken of the interaction between the biological and economic components of the fishing system, is dealt with in the final section
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