2,242 research outputs found

    A trans10-18:1 enriched fraction from beef fed a barley grain-based diet induces lipogenic gene expression and reduces viability of HepG2 cells.

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    Beef fat is a natural source of trans (t) fatty acids, and is typically enriched with either t10-18:1 or t11-18:1. Little is known about the bioactivity of individual t-18:1 isomers, and the present study compared the effects of t9-18:1, cis (c)9-18:1 and trans (t)-18:1 fractions isolated from beef fat enriched with either t10-18:1 (HT10) or t11-18:1 (HT11). All 18:1 isomers resulted in reduced human liver (HepG2) cell viability relative to control. Both c9-18:1 and HT11were the least toxic, t9-18:1had dose response increased toxicity, and HT10 had the greatest toxicity (P<0.05). Incorporation of t18:1 isomers was 1.8-2.5 fold greater in triacylglycerol (TG) than phospholipids (PL), whereas Δ9 desaturation products were selectively incorporated into PL. Culturing HepG2 cells with t9-18:1 and HT10 increased (P<0.05) the Δ9 desaturation index (c9-16:1/16:0) compared to other fatty acid treatments. HT10 and t9-18:1 also increased expression of lipogenic genes (FAS, SCD1, HMGCR and SREBP2) compared to control (P<0.05), whereas c9-18:1 and HT11 did not affect the expression of these genes. Our results suggest effects of HT11 and c9-18:1 were similar to BSA control, whereas HT10 and t-9 18:1 (i.e. the predominant trans fatty acid isomer found in partially hydrogenated vegetable oils) were more cytotoxic and led to greater expression of lipogenic genes

    Synthesis of recrystallized anatase TiO2 mesocrystals with Wulff shape assisted by oriented attachment

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)In this work, we describe a kinetically controlled crystallization process assisted by an oriented attachment (OA) mechanism based on a nonaqueous sol-gel synthetic method (specifically, the reaction of titanium(IV) chloride (TiCl4) with n-octanol) to prepare re-crystallized anatase TiO2 mesocrystals (single crystal). The kinetics study revealed a multi-step and hierarchical process controlled by OA, and a high resolution transmission electron microscopy (HRTEM) analysis clearly shows that the synthesized mesocrystal presents a truncated bipyramidal Wulff shape, indicating that its surface is dominated by {101} facets. This shape is developed during the recrystallization step. The material developed here displayed superior photocatalytic activity under visible light irradiation compared to TiO2-P25 as a benchmarking.3419101916Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FINEPConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [98/14324-0

    Antifouling Marine Coatings with a Potentially Safer and Sustainable Synthetic Polyphenolic Derivative

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    The development of harmless substances to replace biocide-based coatings used to prevent or manage marine biofouling and its unwanted consequences is urgent. The formation of biofilms on submerged marine surfaces is one of the first steps in the marine biofouling process, which facilitates the further settlement of macrofoulers. Anti-biofilm properties of a synthetic polyphenolic compound, with previously described anti-settlement activity against macrofoulers, were explored in this work. In solution this new compound was able to prevent biofilm formation and reduce a pre-formed biofilm produced by the marine bacterium, Pseudoalteromonas tunicata. Then, this compound was applied to a marine coating and the formation of P. tunicata biofilms was assessed under hydrodynamic conditions to mimic the marine environment. For this purpose, polyurethane (PU)-based coating formulations containing 1 and 2 wt.% of the compound were prepared based on a prior developed methodology. The most effective formulation in reducing the biofilm cell number, biovolume, and thickness was the PU-based coating containing an aziridine-based crosslinker and 2 wt.% of the compound. To assess the marine ecotoxicity impact of this compound, its potential to disrupt endocrine processes was evaluated through the modulation of two nuclear receptors (NRs), peroxisome proliferator-activated receptor gamma (PPAR gamma), and pregnane X receptor (PXR). Transcriptional activation of the selected NRs upon exposure to the polyphenolic compound (10 mu M) was not observed, thus highlighting the eco-friendliness towards the addressed NRs of this new dual-acting anti-macro- and anti-microfouling agent towards the addressed NRs

    Contribution des isotopes de l’environnement pour la comprehension du fonctionnement de l’aquifere mio-plioquaternaire du Haouz de Marrakech (Maroc)

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    The study area «Haouz plain» is Located at the center of Morocco, it extend on a surface of 2800 km2, limited by the Jbilet hills in the North, the High-Atlas range in the South, R' dat wadi in the East and the Essaouira-Chichaoua plateau in the West. The area climate is semi-arid, characterized by low precipitations varying between 160 mm/year and 250mm/year and important variation in temperature between the winter and the summer with respectively 5°C and 45°C. Its hydrographic network is represented by the Tensift system which receives all the affluents of central and Westem Haouz. These affluents are characterized by weak flows with important seasonal variations. The Haouz plain is a sedimentary basin, being along the northern edge of the high atlas, it presents a geologic succession going from the primary to the recent Quaternary. The mio-plioquatemary formations, stemming from the dismantling of the atlasic chain, refuge an important and generalized water table on al1 the plain. This water table shows very variable hydrodynarnic characteristics, reflecting the complexity of the deep structures of the plain, 1986) and also the lithological variability of the mio-plioquatemary formations. The Haouz plain includes also the deep resemoirs of the Jurassic, Cretaceous and Eocene which finish some meters at the north of the Atlas, thus having a very limited extension and thereafter a low productivity. Five representative samples of water taken on the haouz water table were analyzed by the ABHT, the projection of these contents on the potability diagram enabled us to show that water of the water table generally has a good quality to passable. In the east quality becomes poor related to the existence of a zone arranged for agriculture (piezometer 1903/44). The nastiest potability is obsemed on the piezometer 3828/44 located at north of Marrakech at elazouzia zone of spreading of wom water of this city. The representation of the percentages of anions and major cations shows the prevalence of ions Ca2+ and HCO; and makes it possible to show up the Bicarbonate calcic facies of the water table. During these last decades, the use of stable isotopes, such oxygen 18 and deuterium, became necessary for the study of subsoil waters, it makes possible the estimation of the surfaces of refills, the determination of water origin. The samples taken on water points well distributed in the area of study allowed us a better comprehension of the function of the plioquatemary water table. The relation oxygen 18, deuterium shows that water is aligned on a line of slope 8.09, slightly different from the world meteoric line, thus characterizing precipitations of oceanic origin which did not endure notable isotopic fractionation therefore not important evaporation. Using the isotopic measures for the sarnples taken in January 2002 on wells well distributed in the area of study, allows us to show a variation of the contents of 018 with the altitude of the zones of refill. Thus we could delimit the surfaces of refill between 1500 and 800meters height. The relation oxygen-18 deuterium (δ2H = 8,9032 δ18O + 14,214 (R2 = 0,7449 ) translated an Atlantic mode of precipitations without remarkable evaporation.Parmi les aquifères régionaux importants de très grande extension au Maroc, celui du Haouz qui s’étend sur une superficie de 6.000 km2, circule au niveau du remplissage mioplioquaternaire issue du démantèlement de la chaîne Atlasique. Ce dernier présente un faciès constitué de galets, graviers, argiles, marnes et calcaires, dont la puissance atteint les 100 mètres. Cet aquifère joue un rôle très important dans l’alimentation en eau potable des habitants de la plaine du Haouz d’une population de plus de 4 millions d’habitants, en sus d’un complément a l’irrigation de 80.000 ha. Le climat aride de type continental, qui y règne se caractérise par des amplitudes thermiques assez importantes entre l’hiver et l’été. La pluviométrie présente une moyenne de 250 mm par an. La piézométrie de la zone étudiée est caractérisée par un écoulement général du sud vers le nord ouest en direction de l’oued Tensift, également principal collecteur des eaux de surface de la région. Une campagne de mesures isotopiques de plus d’une vingtaine d’échantillons prélevés en janvier 2002 au niveau de puits bien répartis dans la zone d’étude, au pu montrer une variation des teneurs en O" avec l’altitude des zones de recharge. En outre, la relation oxygene-18 deutérium (δ2H = 8,9032 δ18O + 14,214 (R2 = 0,7449 traduit un régime atlantique des précipitations, sans évaporation, ce qui implique que la recharge se fait rapidement, probablement a travers les formations miocènes gréseuses largement fissurées a l’affleurement de l’aquifère mío-plioquatemaire. Un gradient altitudinal moyen de -0,26 ‰ par 100 mètres est déterminé pour la plaine du Haouz, très proche des autres valeurs trouvées pour d’autres régions au Maroc, confirmant la validité régionale de celui-ci. Les variations des teneurs en oxygene-18 peuvent être interprétées en termes de différence d’altitude entre les altitudes de recharge et d’émergence

    Leishmania amazonensis Arginase Compartmentalization in the Glycosome Is Important for Parasite Infectivity

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    In Leishmania, de novo polyamine synthesis is initiated by the cleavage of L-arginine to urea and L-ornithine by the action of arginase (ARG, E.C. 3.5.3.1). Previous studies in L. major and L. mexicana showed that ARG is essential for in vitro growth in the absence of polyamines and needed for full infectivity in animal infections. The ARG protein is normally found within the parasite glycosome, and here we examined whether this localization is required for survival and infectivity. First, the localization of L. amazonensis ARG in the glycosome was confirmed in both the promastigote and amastigote stages. As in other species, arg− L. amazonensis required putrescine for growth and presented an attenuated infectivity. Restoration of a wild type ARG to the arg− mutant restored ARG expression, growth and infectivity. In contrast, restoration of a cytosol-targeted ARG lacking the glycosomal SKL targeting sequence (argΔSKL) restored growth but failed to restore infectivity. Further study showed that the ARGΔSKL protein was found in the cytosol as expected, but at very low levels. Our results indicate that the proper compartmentalization of L. amazonensis arginase in the glycosome is important for enzyme activity and optimal infectivity. Our conjecture is that parasite arginase participates in a complex equilibrium that defines the fate of L-arginine and that its proper subcellular location may be essential for this physiological orchestration
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