675 research outputs found

    Photocatalytic degradation of methyl-red by immobilised nanoparticles of TiO2 and ZnO

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    none6noIn this work, we report on the degradation of methyl-red (2-(4-Dimethylamino-phenylazo)-benzoic acid - C.I. 13020) under UV irradiation in the presence of nanosized ZnO and TiO2. Oxide nanocrystals with controlled size were synthesised by using non-hydrolytic approaches and tested for the photocatalysed degradation. The performances of the immobilised nanoparticles were compared with their commercial counterparts after immobilization onto a solid support. The influence of some experimental conditions, namely pH and dye concentration, were investigated by monitoring the dye decoloration spectrophotometrically. Several intermediate by-products were identified by HPLC-MS, showing that two different mechanisms were operative during the photocatalytic oxidationsee at: http://www.iwaponline.com/wst/04904/wst049040183.htmopenR. COMPARELLI; P. D. COZZOLI; M. L. CURRI; A. AGOSTIANO; G. MASCOLO; G. LOVECCHIOR., Comparelli; Cozzoli, Pantaleo Davide; M. L., Curri; A., Agostiano; G., Mascolo; G., Lovecchi

    Exchange-coupled bimagnetic cobalt/iron oxide branched nanocrystal heterostructures.

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    A colloidal seeded-growth strategy, relying on time-programmed delivery of selected stabilizing surfactants, has been developed to synthesize bimagnetic hybrid nanocrystals (HNCs) that consist of a single-crystal tetrapod-shaped skeleton of ferrimagnetic (FiM) iron oxide functionalized with multiple polycrystalline spherical domains of ferromagnetic (FM) Co. Due to the direct bonding interfaces formed between the two materials at the relevant junction regions, the HNCs exhibit FiM-FM exchange coupling, which transcribes into a rich scenario of significantly modified properties (not otherwise achievable with any of the single components or with their physical mixtures), including higher saturation magnetization and coercitivity values, exchange biasing, and enhanced thermal stability due to induced extra anisotropy. The availability of these new types of HNCs suggests that development of appropriate synthetic tools for arranging distinct material domains in predetermined spatial arrangements could lead to ..

    Three-Dimensional Self-Assembly of Networked Branched TiO2 Nanocrystal Scaffolds for Efficient Room-Temperature Processed Depleted Bulk Heterojunction Solar Cells

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    In this work, we report on 4% power conversion efficiency (PCE) depleted bulk heterojunction (DBH) solar cells based on a high-quality electrode with a three-dimensional nanoscale architecture purposely designed so as to maximize light absorption and charge collection. The newly conceived architecture comprises a mesoporous electron-collecting film made of networked anisotropic metal-oxide nanostructures, which accommodates visible-to-infrared light harvesting quantum dots within the recessed regions of its volume. The three-dimensional electrodes were self-assembled by spin-coating a solution of colloidal branched anatase TiO2 NCs (BNC), followed by photocatalytic removal of the native organic capping from their surface by a mild UV-light treatment and filling with small PbS NCs via infiltration. The PCE = 4% of our TiO2 BNC/PbS QD DBH solar cell features an enhancement of 84% over the performance obtained for a planar device fabricated under the same conditions. Overall, the DBH device fabrication procedure is entirely carried out under mild processing conditions at room temperature, thus holding promise for low-cost and large-scale manufacturing

    Double In Situ Approach for the Preparation of Polymer Nanocomposite with Multi-functionality

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    A novel one-step synthetic route, the double in situ approach, is used to produce both TiO2nanoparticles and polymer (PET), and simultaneously forming a nanocomposite with multi-functionality. The method uses the release of water during esterification to hydrolyze titanium (IV) butoxide (Ti(OBu)4) forming nano-TiO2in the polymerization vessel. This new approach is of general significance in the preparation of polymer nanocomposites, and will lead to a new route in the synthesis of multi-functional polymer nanocomposites

    Genomic and personalized medicine approaches for substance use disorders (SUDs) looking at genome-wide association studies

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    Drug addiction, or substance use disorder (SUD), is a chronic, relapsing disorder in which compulsive drug-seeking and drug-taking behaviour persist despite serious negative consequences. Drug abuse represents a problem that deserves great attention from a social point of view, and focuses on the importance of genetic studies to help in understanding the genetic basis of addiction and its medical treatment. Despite the complexity of drug addiction disorders, and the high number of environmental variables playing a role in the onset, recurrence, and duration of the symptoms, several studies have highlighted the non-negligible role of genetics, as demonstrated by heritability and genome-wide association studies. A correlation between the relative risk of addiction to specific substances and heritability has been recently observed, suggesting that neurobiological mechanisms may be, at least in part, inherited. All these observations point towards a scenario where the core neurobiological factors of addiction, involving the reward system, impulsivity, compulsivity, stress, and anxiety response, are transmitted, and therefore, genes and mutations underlying their variation might be detected. In the last few years, the development of new and more efficient sequencing technologies has paved the way for large-scale studies in searching for genetic and epigenetic factors affecting drug addiction disorders and their treatments. These studies have been crucial to pinpoint single nucleotide polymorphisms (SNPs) in genes that affect the reaction to medical treatments. This is critically important to identify pharmacogenomic approaches for substance use disorder, such as OPRM1 SNPs and methadone required doses for maintenance treatment (MMT). Nevertheless, despite the promising results obtained by genome-wide association and pharmacogenomic studies, specific studies related to population genetics diversity are lacking, undermining the overall applicability of the preliminary findings, and thus potentially affecting the portability and the accuracy of the genetic studies. In this review, focusing on cannabis, cocaine and heroin use, we report the state-of-the-art genomics and pharmacogenomics of SUDs, and the possible future perspectives related to medical treatment response in people that ask for assistance in solving drug-related problems

    Responsive DNA G-quadruplex micelles

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    A novel and versatile design of DNA-lipid conjugates is presented. The assembly of the DNA headgroups into G-quadruplex structures is essential for the formation of micelles and their stability. By hybridization with a complementary oligonucleotide the micelles were destabilized, resulting in cargo release. In combination with a hairpin DNA aptamer as complementary strand, the release is obtained selectively by the presence of ATP

    Hindcasting Ecosystem Functioning Change in an Anthropogenized Estuary: Implications for an Era of Global Change

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    Understanding how altered hydrodynamics related to climate change and anthropogenic modifications affect ecosystem integrity of shallow coastal soft-sediment environments requires a sound integration of how species populations influence ecosystem functioning across heterogeneous spatial scales. Here, we hindcasted how intertidal habitat loss and altered hydrodynamic regimes between 1955 and 2010 associated with geomorphological change to accommodate expansion in anthropogenic activities in the Western Scheldt altered spatial patterns and basin-wide estimates of ecosystem functioning. To this end we combined an empirically derived metabolic model for the effect of the common ragworm Hediste diversicolor on sediment biogeochemistry (measured as sediment oxygen uptake) with a hydrodynamic and population biomass distribution model. Our integrative modeling approach predicted an overall decrease by 304 tons in ragworm biomass between 1955 and 2010, accounting for a reduction by 28% in stimulated sediment oxygen uptake at the landscape scale. Local gains or losses in habitat suitability and ecosystem functioning were primarily driven by changes in maximal current velocities and inundation regimes resulting from deepening, dredging and disposal practices. By looking into the past, we have demonstrated how hydro- and morphodynamic changes affect soft-sediment ecology and highlight the applicability of the integrative framework to upscale anticipated population effects on ecosystem functioning

    Evaluation of potential synergistic action of a combined treatment with alpha-methyl-prednisolone and taurine on the mdx mouse model of Duchenne muscular dystrophy

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    Aims: Glucocorticoids are the sole drugs clinically used in Duchenne muscular dystrophy, in spite of the relevant side effects. Combination of glucocorticoids with synergistic drugs may be one strategy to lower doses and control side effects, meanwhile providing wider control of the complex pathology. This study is a preclinical evaluation of the effect of a combined treatment of amethyl-prednisolone (PDN) with taurine, a safe aminoacid with positive effects on some pathology-related events. Methods: PDN (1 mg/kg/day i.p.) and taurine (1 g/kg/day orally) were administered either alone or in combination, for 4-8 weeks to male dystrophic mdx mice chronically exercised on a treadmill. Effects were assessed in vivo and ex vivo with a variety of methodological approaches. Results: In vivo, each treatment significantly increased fore limb strength, a marked synergistic effect being observed with the combination PDN + taurine. Ex vivo, PDN + taurine completely restored the mechanical threshold, an electrophysiological index of calcium homeostasis, of extensor digitorum longus myofibres and the benefit was greater than for PDN alone. In parallel, the overactivity of voltage-independent cation channels in dystrophic myofibres was reduced. No effects were observed on plasma levels of creatine kinase, while lactate dehydrogenase was decreased by taurine and, to a minor extent, by PDN + taurine. A similar histology profile was observed in PDN and PDN + taurine-treated muscles. PDN + taurine significantly increased taurine level in fast-twitch muscle and brain, by high-pressure liquid chromatography analysis. Conclusions: The combination PDN + taurine has additive actions on in vivo and ex vivo functional end points, with less evident advantages on histopathology and biochemical markers of the disease
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