346 research outputs found

    Novel monomers with N-methyl-D-glucamine segments and their application in structured porous materials for arsenic capture

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    The N-methyl-D-glucamine moieties exhibit high ability and selectivity toward arsenate ions in water by a complexation mechanism that involves their hydroxyl groups. In this work, the syntheses of two monomers containing N-methyl-D-glucamine, namely 4-vinylbenzyl-N-methyl-D-glucamine (VbNMDG), and N-methyl-D-glucamine methacrylamide (MNMDG) were studied. Different synthetic routes were considered in order to obtain liquid monomers able to polymerize and selectively capture arsenic. Furthermore, the incorporation of protective groups like trimethylsilyl moieties in the molecular structure was assessed to prevent transfer reactions during further polymerization. After polymerization, hydroxyl groups were deprotected using hydrofluoric acid. Following this methodology, structured microporous polymeric films based on colloidal crystal templates were prepared. NMR and FTIR techniques were used to follow the reactions and to determine the chemical structure of the obtained products. The morphology of materials was characterized by SEM. The performances of the developed polymeric films to selectively capture arsenic were determined. Films showed an improved and reproducible sensitivity to arsenic detection exhibiting high values of arsenic capturing capability (around 90%)

    Expression of carbohydrate-antigen sialyl-Lewis a on colon cancer cells promotes xenograft growth and angiogenesis in nude mice

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    We investigated the role of carbohydrate antigen sialyl-Lewis a (sLea), an E-selectin ligand and epitope of tumor marker CA19.9, in the development of xenografts in nude mice. To this end, animals were inoculated with the human colon cancer cell line HCT-15, expressing no Lewis antigens, or with a clone expressing sLea (HCT-15-T5). The size of HCT-15-T5 xenografts appeared larger than those of HCT-15 and their average weight was over twice bigger. In both xenografts the mitotic index was found elevated, as determined by Ki-67 assay, and no apoptosis was detected in the tumor cells by both caspase 8 or TUNEL assays. Some apoptotic signals were instead detected in the vessels. Conversely, microvessel density, determined through CD-31 immunohistochemistry, was found 3.2-folds bigger in HCT-15-T5 xenografts (p < 0.012). Only the membranes of HCT-15-T5 cells grown as xenografts reacted intensively with the anti CA19.9 antibody 1116-NS-19-9 by immunofluorescence, but not by immunohistochemistry. Unknown structures were instead stained by such technique in both xenografts, as were in mouse tissues not expressing the antigen and in human colon adenocarcinoma. We conclude that expression of sLea on the surface of colon cancer cells improves xenograft growth and is associated with enhanced angiogenesis, while immunohistochemistry with 1116-NS-19-9 antibody appears not suitable to determine CA19.9 expression

    Polylactic acid-lauryl functionalized nanocellulose nanocomposites: Microstructural, thermo-mechanical and gas transport properties

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    Thermo-mechanical and gas transport properties of polylactic acid (PLA) matrix containing various amounts (from 1 to 20 wt%) of nanocellulose esterified with lauryl chains (LNC) were investigated on solvent cast film of about 50 micron. Scanning electron microscopy indicated that, up to a filler content of 6.5 wt%, LNC was well dispersed or formed small, sub-micrometric clusters. At higher filler contents, oval aggregates in the micrometric range were detected. The addition of LNC did not change the matrix glass transition temperature and melting temperature. Concurrently, as LNC content increased, both elastic and storage moduli at room temperature exhibited a sharp decrease up to 5 wt% of filler, and a lower reduction for LCN concentration of 10\u201320 wt.%. Nanocomposites with 3 and 5 wt% of LNC showed the highest strain at break and a large amount of plastic deformation due to a strong interfacial adhesion between the PLA and filler particles. For higher LNC fractions the presence of aggregates weakened the nanocomposite leading to lower values of maximum stress and strain at break. With the addition of LNC particles, gas barrier properties of the PLA film versus deuterium, nitrogen and carbon dioxide were improved up to a critical LNC concentration of 6.5 wt%, where the gas permeability of the nanocomposite resulted to be 70% lower than that of the PLA matrix. At higher filler contents, large LNC aggregates increased the gas permeability of the nanocomposites

    The impact of televised sports on adult nonfiction sports publishing

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    Thyreostats can be used fraudulently to promote a rapid weight increase of breeding animals at low cost. Their severe toxicological effects impose the development of reliable analytical methods to be used in monitoring plans. This work describes an alternative approach to isolate residues of thiouracil, methyl-thiouracil, propyl-thiouracil, phenyl-thiouracil, tapazole and mercaptobenzimidazole from bovine muscle tissue. The developed procedure is based on three steps: i) matrix solid phase dispersion with C18 for the preliminary sample preparation; ii) subcritical water extraction (SWE) at 160°C and 100 bar; iii) clean-up on an Oasis HLB cartridge. The quantitative determination was performed by liquid chromatography-electrospray-tandem mass spectrometry (LC-MS/MS) in dual polarity ionization by using internal standardization. The SWE-LC-MS/MS method was validated according to the identification criteria of the Commission decision 2002/657/EC. The relative recoveries ranged from 72% to 97%; within-lab reproducibility was less than 18%. The decision limit and the detection capability of all analytes were below the recommended concentration, set at 10 µg kg−1, but the validation results demonstrated that this method could only be applied for screening of thiouracil and methyl-thiouracil. Besides the analytical advantages related to the use of water as solvent extraction, the procedure allowed significant removal of lipids, whose detrimental effects on instrumentation and MS sensitivity are well-known

    Inhibition of Sphingolipid Synthesis as a Phenotype-Modifying Therapy in Cystic Fibrosis

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    Cystic Fibrosis (CF) is an inherited disease associated with a variety of mutations affecting the CFTR gene. A deletion of phenylalanine 508 (F508) affects more than 70% of patients and results in unfolded proteins accumulation, originating a proteinopathy responsible for inflammation, impaired trafficking, altered metabolism, cholesterol and lipids accumulation, impaired autophagy at the cellular level. Lung inflammation has been extensively related to the accumulation of the lipotoxin ceramide. We recently proved that inhibition of ceramide synthesis by Myriocin reduces inflammation and ameliorates the defence response against pathogens infection, which is downregulated in CF. Here, we aim at demonstrating the mechanisms of Myriocin therapeutic effects in Cystic Fibrosis broncho-epithelial cells

    Sphingolipid synthesis inhibition by myriocin administration enhances lipid consumption and ameliorates lipid response to myocardial ischemia reperfusion injury

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    Myocardial infarct requires prompt thrombolytic therapy or primary percutaneous coronary intervention to limit the extent of necrosis, but reperfusion creates additional damage. Along with reperfusion, a maladaptive remodeling phase might occur and it is often associated with inflammation, oxidative stress, as well as a reduced ability to recover metabolism homeostasis. Infarcted individuals can exhibit reduced lipid turnover and their accumulation in cardiomyocytes, which is linked to a deregulation of peroxisome proliferator activated receptors (PPARs), controlling fatty acids metabolism, energy production, and the anti-inflammatory response. We previously demonstrated that Myriocin can be effectively used as post-conditioning therapeutic to limit ischemia/reperfusion-induced inflammation, oxidative stress, and infarct size, in a murine model. In this follow-up study, we demonstrate that Myriocin has a critical regulatory role in cardiac remodeling and energy production, by up-regulating the transcriptional factor EB, PPARs nuclear receptors and genes involved in fatty acids metabolism, such as VLDL receptor, Fatp1, CD36, Fabp3, Cpts, and mitochondrial FA dehydrogenases. The overall effects are represented by an increased \u3b2-oxidation, together with an improved electron transport chain and energy production. The potent immunomodulatory and metabolism regulatory effects of Myriocin elicit the molecule as a promising pharmacological tool for post-conditioning therapy of myocardial ischemia/reperfusion injury

    Phosphoryl-EZH-ion

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    Polycomb group (PcG) proteins regulate gene expression in embryonic and adult stem cells, but the mechanisms responsible for PcG gene targeting and regulation remain largely unknown. Recent evidence shows that EZH2, the enzymatic subunit of Polycomb Repressive Complex 2 (PRC2), is a nuclear phosphoprotein linking cell-cycle-intrinsic or extracellular signals to specific epigenetic signatures. © 2011 Elsevier Inc

    The right to food and food diversity in the Italian Constitution

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    Il contributo analizza la tutela apprestata dalla Costituzione italiana al diritto al cibo che, pur non essendo espressamente menzionato, viene ricavato attraverso l'analisi di principi ed azioni sottese alla nostra Carta che ne riconoscono il valore: il principio lavorista, la lotta alla povertà, la retribuzione del lavoratore...

    De novo ceramide synthesis is involved in acute inflammation during labor

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    Gestation is regulated by an inflammatory process that allows implantation and parturition. The comprehension of such inflammatory switches is important for the identification of therapeutic targets in pregnancy defects. Sphingolipids are a class of structural membrane components with important signaling functions. Among sphingolipids, ceramide is a well-known mediator of stress signals and pro-inflammatory responses. In this paper, we evaluated the association between ceramide increase and the inflammatory process of labor, comparing placentas from vaginal deliveries, including both spontaneous and induced labor, versus elective cesarean. We demonstrated that: (i) the inflammatory marker IL-6 is upregulated in labored placentas; (ii) IL-6 content inversely correlates with labor duration; (iii) ceramide content and expression of serine palmitoyl transferase (SPT, rate limiting enzyme for de novo ceramide synthesis) are increased in labored placentas; (iv) the expression of SPT directly correlates with inflammation and inversely with labor duration. These observations suggest that ceramide metabolism and signaling may be implicated in controlling important inflammatory mechanisms driving gestation: we hypothesize that ceramide can be a therapeutic target in inflammatory complications of parturition
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