Search

In this study, we investigate the influence of crude and surface-treated graphite by diazonium salt on the thermoelectric (TE) properties of six different mixtures of polypyrrole (PPy)-based ternary composites, which also contain poly(3,4- ethylenedioxythiophene) (PEDOT) or PEDOT:PSS and are prepared either by direct mixing procedure or copolymerization route according to an optimized formulation (Polymer I-Charges-Polymer II). The surface treatment, by 4-carboxybenzenediazonium tetrafluoroborate (DS-COOH), of reduced graphene oxide (FrGO) has been found to significantly improve TE properties of composites, wherein the higher obtained value of figure of merit (zT) has been greatened by a magnitude of 240 times comparatively to PPy alone. Moreover, composites obtained by the direct mixing process of component has exhibited more than twice the value of zT than that of composites obtained by the copolymerization method. Hence, surface treatment of FrGO by diazonium salt refines its seeked role in improving TE properties of polymeric composites and makes it a promising element when incorporated within organic composites to reach higher TE features., In this study, we investigate the influence of crude and surface-treated graphite by diazonium salt on the thermoelectric (TE) properties of six different mixtures of polypyrrole (PPy)-based ternary composites, which also contain poly(3,4-ethylenedioxythiophene) (PEDOT) or PEDOT:PSS and are prepared either by direct mixing procedure or copolymerization route according to an optimized formulation (Polymer I-Charges-Polymer II). The surface treatment, by 4-carboxybenzenediazonium tetrafluoroborate (DS-COOH), of reduced graphene oxide (FrGO) has been found to significantly improve TE properties of composites, wherein the higher obtained value of figure of merit (zT) has been greatened by a magnitude of 240 times comparatively to PPy alone. Moreover, composites obtained by the direct mixing process of component has exhibited more than twice the value of zT than that of composites obtained by the copolymerization method. Hence, surface treatment of FrGO by diazonium salt refines its seeked role in improving TE properties of polymeric composites and makes it a promising element when incorporated within organic composites to reach higher TE features.

We focus on the maximum number of minimal transversals in 3-partite 3-uniform hypergraphs on n vertices. Those hypergraphs (and their minimal transversals) are commonly found in database applications. In this paper we prove that this number grows at least like 1.4977^n and at most like 1.5012^n.

Cyclic triimidazole (C9H6N6, L), with C3h molecular symmetry and three nitrogen atoms available for coordination, is here successfully employed for the first time in the synthesis of coordination compounds. In particular, by varying the reaction conditions (e.g., solvent, temperature, template), seven Cu(I)-halide coordinat on polymers of different dimensionality are obtained: two 1D polymers, [CuIL]n (1) and {[CuIL]·(I2)0.5}n (2), three 2D nets, [CuXL]n (X = I, Br) (3-5), and two 3D networks, [CuClL]n (6) and {[Cu3L4]I3}n (7). Single crystal X-ray diffraction analysis reveals that the structural versatility of both the ligand and the CuX moiety allows isolating 1D double-stranded stairs in which L is monodentate, 2D layers containing either Cu2(?-X)2 or Cu2(?-X) moieties and bidentate L ligands, 3D frameworks built up by tridentate L linkers and either monodentate or noncoordinating halogen atoms. The 3D frameworks show nets of srs and bor topologies. The SHG efficiency of powders of 7 (the only noncentrosymmetric derivative of the series) is 10 times higher than that of sucrose. Phosphorescent emission of XLCT character is observed for 1 and 6.

348-348 В статье построены (3,3)-однородные квантовые логики с произвольным четным чис- лом атомов, начиная с 18. Для этих логик описаны их группы автоморфизмов. This paper describes a (3,3)-homogeneous quantum logics with an arbitrary even numbers of atoms beginning from 18. For this logics we find their automorphism groups.

An algorithm to compute the curve skeleton of 3D objects in voxel images is presented. The skeleton is stable under isometric transformations of the object, since the algorithm is based on the use of the (3, 4, 5) weighted distance transform, which is a good approximation of the Euclidean distance transform. The (3, 4, 5) weighted distance transform is used both to identify suitable anchor points, and to efficiently check object voxels according to their distance to the background. The curve skeleton is symmetrically placed within the object, is topologically equivalent to the object, is unit-wide and provides a satisfactory representation of the object. Though the size of the object reconstructed from the curve skeleton via the reverse distance transformation is not as thick as that of the input, shape information is mostly retained by the skeleton, since all regions perceived as significant in the input can still be found in the reconstructed object.

The Constitutive Androstane Receptor (CAR) belongs to the subfamily of nuclear receptors NR1. Initially described as an orphan receptor, CAR is activated by a large number of exogenous molecules and acts as a xenosensor. The activation of CAR by these ligands stimulates transcription of phase I, II and III enzymes required for the detoxification and elimination of xenobiotics. Furthermore CAR is also involved in the metabolism of endogenous molecules such as bile acids, bilirubin or thyroid hormones. CAR has recently been the subject of numerous independent studies that have highlighted his involvement in major metabolic pathways including gluconeogenesis, lipogenesis and lipoprotein metabolism, making CAR as well as others NR1 nuclear receptors potential targets for the study and the treatment of metabolic syndrome and cardiovascular diseases. The goal of our work was to determine the impact of a chronic CAR activation on reverse cholesterol transport, lipoprotein metabolism and susceptibility to atherosclerosis in a context of dietary cholesterol overload. In dyslipidemic mice deficient for the low density lipoprotein receptor (Ldlr-/-) or for apolipoprotein E (ApoE-/-), pharmalogical activation of CAR by its specific agonist TCPOBOP (3,3',5,5'-Tetrachloro-1, 4-bis (pyridyloxy) benzene) 1) reduces lipogenesis through the induction of Insig1 and the repression of the transcription factor Srebp1c (meaning..) and its target genes. This results in a decrease in plasma triglyceride levels associated with a reduced hepatic triglycerides concentration and a decreased secretion of triglyceride-rich lipoproteins, 2) stimulates the conversion and fecal cholesterol elimination as bile acids and consequently the last step of reverse cholesterol transport, 3) in Ldlr-/- mice, CAR activation decreases LDL-cholesterol probably through the stimulation of hepatic expression of very low density lipoprotein receptor.Reduction in the atherogenicity of the lipoprotein profile and increase of reverse cholesterol transport lead to a reduction in the size of atherosclerotic lesions in heart valves and aorta in Ldlr-/- mice. Reduction of aortic lesions in aortic arches only was also observed in apoE-/- mice. The present work as well as recent studies suggests that CAR is as central player in lipid metabolism. CAR appears therefore to be a new potential target for the study and the treatment of metabolic disorders like diabetes, obesity, fatty liver and atherosclerosis, Le récepteur CAR, Constitutive Androstane Receptor, appartient à la-famille NR1 des récepteurs nucléaires. Initialement décrit comme un récepteur orphelin, CAR est en fait activé par un grand nombre de molécules exogènes et une des fonctions principales de CAR est celle de xénosenseur. L’activation CAR par ses différents ligands stimule la transcription des enzymes de phase I, II et III nécessaires à la détoxification et à l’élimination des xénobiotiques. Parallèlement, CAR a fait l’objet de nombreux travaux indépendants qui ont démontré son implication dans le métabolisme de molécules endogènes comme les acides biliaires, la bilirubine et les hormones thyroïdiennes. Plus récemment un impact de CAR sur des voies métaboliques fondamentales comme la néoglucogenèse, la lipogenèse et le métabolisme des lipoprotéines a été mis en évidence faisant de CAR au même titre que les récepteurs du groupe NR1 (LXR et FXR) une cible potentielle pour l’étude et le traitement du syndrome métabolique et des maladies cardio-vasculaires. Dans le cadre de ce mémoire nous avons étudié l’impact d’une stimulation chronique de CAR par un agoniste spécifique le TCPOBOP sur le transport reverse du cholestérol, le métabolisme des lipoprotéines et la susceptibilité à l’athérosclérose dans un contexte de surcharge alimentaire en cholestérol. Chez les souris dyslipidémiques déficientes pour le gène du récepteur aux lipoprotéines de faible densité (Ldlr-/-) ou bien déficientes pour l’apoprotéine E l’activation spécifique de CAR par l’agoniste TCPOBOP (3,3’,5,5’-Tétrachloro-1,4-bis (pyridyloxy )benzene), 1) diminue la lipogenèse via l’induction du facteur Insig1 et la répression du facteur de transcription Srebp1c et de ses gènes cibles. Cela se traduit par une diminution de la triglycéridémie plasmatique associée à une diminution du contenu hépatique en triglycérides et une diminution de la sécrétion de lipoprotéines riches en triglycérides, 2) stimule la conversion et l’élimination fécale du cholestérol sous forme d’acides biliaires ce qui se traduit par une élimination accrue du cholestérol dérivé des HDL dans les fèces, dernière étape du transport reverse du cholestérol, 3) diminue le taux de cholestérol associé aux LDL chez les souris Ldlr-/- probablement par stimulation de l’expression hépatique du récepteur aux lipoprotéines de très basse densité. La diminution de l’athérogénicité du profil lipoprotéique et la stimulation du transport reverse du cholestérol sont associées à une réduction des lésions athéromateuses au niveau des valves et de la crosse aortique chez les souris Ldlr-/-. Une diminution des lésions athéromateuses uniquement au niveau de la crosse aortique est également observée chez les souris ApoE-/- L’ensemble des travaux présentés et les récentes études publiées suggèrent que CAR peut être considéré comme un acteur central du métabolisme lipidique et font de ce récepteur nucléaire une nouvelle cible potentielle pour l’étude et le traitement des désordres métaboliques comme le diabète, l’obésité, la stéatose hépatique et l’athérosclérose

Schiff bases are used as substrates in the preparation of a large of bioactive and industrial compounds via ring closure, cycloaddition, replacement reactions, etc [1].[...]