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Diselenide
Kinds of Diselenide Selected AbstractsDiselenide- and Disulfide-Mediated Synthesis of IsocoumarinsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2010Sohail A. Shahzad Abstract Cyclizations of stilbenecarboxylic acids to the corresponding isocoumarin derivatives using diselenide or disulfide reagents have been developed. By employing bis(triflouroacetoxy)iodobenzene as oxidant for the 6- endo - trig cyclizations a variety of dihydroisocoumarins have been prepared in good yields. This method is capable of forming isocoumarins and dihydroisocoumarin derivatives by a cyclization,elimination route. [source] Diphenyl Diselenide and Ascorbic Acid Changes Deposition of Selenium and Ascorbic Acid in Liver and Brain of MiceBASIC AND CLINICAL PHARMACOLOGY & TOXICOLOGY, Issue 3 2001Maria Caroline Jacques-Silva These compounds have been reported to inhibit the cerebral and hepatic aminolevulinic acid dehydratase (ALA-D) in vitro, and now we show that ascorbic acid can reverse some alterations caused by in vivo selenium exposure, but not ALA-D inhibition. The effect of Na2SeO3 or (PhSe)2 and ascorbic acid on selenium distribution, total non-protein thiol, ascorbic acid content (liver and brain) and haemoglobin was also examined. Mice were exposed to 250 ,mol/kg (PhSe)2, or 18.75 ,mol/kg Na2SeO3 subcutaneously, and to ascorbic acid, twice a day, 1 mmol/kg intraperitonially, for 10 days. Hepatic ALA-D of mice treated with (PhSe)2 was inhibited about 58% and similar results were observed in the animals that received ascorbic acid supplementation (P<0.01, for (PhSe)2 -treated and (PhSe)2+ascorbic acid-treated mice). The haemoglobin content decreased after treatment with (PhSe)2 (P<0.01). However, the haemoglobin content of the (PhSe)2+ascorbic acid group was significantly higher than in the (PhSe)2 -treated mice (P<0.05), and similar to control (P>0.10). Ascorbic acid treatment decreased significantly the hepatic and cerebral deposition of Se in (PhSe)2 -exposed mice (P<0.01). Hepatic non-protein thiol content was not changed by treatment with (PhSe)2, ascorbic acid or (PhSe)2+ascorbic acid. Hepatic content of ascorbic acid was twice that in mice that received (PhSe)2, independent of ascorbic acid treatment (P<0.001). The results of this study suggest that vitamin C may have a protective role in organodiselenide intoxication. [source] ChemInform Abstract: Oxidation of Alkynes in Aqueous Media Catalyzed by Diphenyl Diselenide.CHEMINFORM, Issue 39 2010Stefano Santoro Abstract An unprecedented transformation is discovered under conditions A). [source] ChemInform Abstract: The Reaction of Mono-Aryl Substituted Methylenecyclobutanes with Diphenyl Diselenide in the Presence of Iodosobenzene Diacetate and H2O.CHEMINFORM, Issue 22 2009Min Jiang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Hydrothiolation of Terminal Alkynes with Diaryl Disulfides and Diphenyl Diselenide: Selective Synthesis of (Z)-1-Alkenyl Sulfides and Selenides.CHEMINFORM, Issue 12 2009Zhang-Lin Wang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Copper(II) Acetate Mediated Reactions of Methylenecyclopropane and Diphenyl Diselenide.CHEMINFORM, Issue 42 2007Lei Yu Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Ring-Opening Reactions of Methylenecyclopropanes with Diphenyl Diselenide upon Heating; Formation of 3-Phenylselenyl-2,5-dihydrofuran Derivatives.CHEMINFORM, Issue 18 2005Le-Ping Liu Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Oxidation of Diphenyl Diselenide with 2,3-Dichloro-5,6-dicyanobenzoquinone (DDQ).CHEMINFORM, Issue 10 2002A New Method for the Electrophilic Phenylselenenylation of Alkenes under Mild Conditions. Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Dielectric properties of thallium gallium diselenide layered crystal in the incommensurate phaseCRYSTAL RESEARCH AND TECHNOLOGY, Issue 9 2005entürk Abstract The dielectric measurements of the layered crystal were studied in temperature range of successive phase transitions. The measurements revealed that the phase transition occurred in 242 K is an incommensurate phase transition. When the sample is annealed at a stabilized temperature in the incommensurate phase, a remarkable memory effect has been observed on cooling run. The mechanism of the memory effect in the incommensurate phase of the semiconducting ferroelectric TlGaSe2 can be interpreted in the frame of the theory of defect density waves. This theory claims that the memory effect is the result of pinning of the incommensurate structure by the lattice inhomogeneities. With decreasing the annealing temperature the phase transition temperature shifts to lower temperatures gradually. Moreover, the peak intensities also increase gradually. In addition to these effects, the phase transition temperature shifts to lower temperatures with increasing annealing time. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Platinum Complexes of Aromatic SelenolatesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 25 2010Amy L. Fuller Abstract Several synthetic methods are used to prepare naphthalene-based aromatic 1,2-diselenoles. A new one-pot synthesis starting from naphthalene is used to produce theknown compound naphtho[1,8- c,d][1,2]diselenole (Se2naph).Friedel,Crafts alkylation is used on Se2naph to substitute either one tert -butyl group to form 2- tert -butylnaphtho[1,8- c,d][1,2]diselenole (mt-Se2naph) or two tert -butyl groups to form 2,7-di- tert -butylnaphtho[1,8- c,d][1,2]diselenole (dt-Se2naph). Bromination of mt-Se2naph results in dibromination of the naphthalene ring, rather than reaction at selenium, to give 4,7-dibromo-2- tert -butylnaphtho[1,8- c,d][1,2]diselenole (mt-Se2naphBr2). Reduction of the Se,Se bond in Se2naph, mt-Se2naph, dibenzo[c,e][1,2]diselenine (dibenzSe2), or diphenyl diselenide (Se2Ph2) with LiBEt3 H, followed by in-situ addition of [PtCl2{P(OPh)3}2] yields the four-coordinate mono- and dinuclear platinum(II) bis(phosphite) complexes [Pt(Se2naph){P(OPh)3}2] (1), [Pt(mt-Se2naph){P(OPh)3}2] (2), [Pt2(dibenzSe2)2{P(OPh)3}2] (3), cis -[Pt(SePh)2{P(OPh)3}2] (4), and trans -[Pt2(SePh)4{P(OPh)3}2] (5). [source] Complexes of Bidentate Phosphane Selenide Ligands with Mesitylenetellurenyl Iodide and with Tellurium Diiodide,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 6 2006Cristian G. Hrib Abstract Bis(diphenylphosphanyl)methane diselenide (dppmSe2, 1) and bis(diphenylphosphanyl)ethane diselenide (dppeSe2, 2) reacted with 2 equiv. Br2 or I2 to form the insoluble solid products, dppm(SeX2)2 (X = Br, 3; X = I, 4) and dppe(SeX2)2 (X = Br, 5; X = I, 6). However, using the iodine-like electrophile mesitylenetellurenyl iodide (MesTeI, 7), fairly soluble complexes, dppmSe2[Te(I)Mes]2 (8) and dppeSe2[Te(I)Mes]2 (9), were obtained. Complexes 8 and 9 contain two T-shaped (10-Te-3) Se,Te(Mes),I moieties bridged by dppm or dppe; solid 9 exhibits intermolecular soft,soft interactions between approximately linear Se,Te,I units. In a side reaction accompanying the crystallisation of complex 8, or by the reaction of 1 with Te and I2, a chelate complex dppmSe2TeI2 (10) was formed. Fortuitously, a crystal of the related compound dppeSe2TeI2 (11) was also obtained. In 10, a square planar cis -Se2TeI2 group is part of a six-membered ring, and 11 is a coordination polymer with trans -Se2TeI2 moieties bridged by dppe. Averaged 31P- and 77Se NMR signals including 77Se,31P couplings, together with broad 125Te NMR singlets indicate phosphane selenide ligand exchange in solution, that is, the kinetically labile behaviour of complexes 8 and 9. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Diselenide- and Disulfide-Mediated Synthesis of IsocoumarinsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2010Sohail A. Shahzad Abstract Cyclizations of stilbenecarboxylic acids to the corresponding isocoumarin derivatives using diselenide or disulfide reagents have been developed. By employing bis(triflouroacetoxy)iodobenzene as oxidant for the 6- endo - trig cyclizations a variety of dihydroisocoumarins have been prepared in good yields. This method is capable of forming isocoumarins and dihydroisocoumarin derivatives by a cyclization,elimination route. [source] Lanthanum(III) Oxide as a Recyclable Catalyst for the Synthesis of Diaryl Sulfides and Diaryl SelenidesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 34 2009Sabbavarapu Narayana Murthy Abstract La2O3 as a new and efficient recyclable catalyst in coupling various aryl halides with aromatic/alkyl thiols and diphenyl diselenide in combination with KOH as a base and DMEDA as a ligand in DMSO at 110 °C is reported. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Synthesis of the First Selenium-Containing Acyclic Nucleosides and Anomeric Spironucleosides from Carbohydrate PrecursorsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 30 2009Susana Maza Abstract We report the synthesis of acyclic and spiranic imidazole-derived C -selenonucleosides. 5-Hydroxy-4-tetrahydroxybutyl imidazolidine-2-selones, a novel class of acyclic selenonucleosides, were transformed into (tetrahydroxybutylimidazol-2-yl)diselenide, by acetylation and chemoselective N -deacetylation with methanolic imidazole. Furthermore, the synthesis of a new class of conformationally restricted arabino -configured spironucleosides containing an imidazolidine-2-selone unit around the glycosidic bond was achieved, starting from N -fructosamines, via 4-hydroxy-4-tetrahydoxybutyl-imidazolidine-2-selones as the key intermediates. Acetylation,deacetylation of these intermediates gave access to stable aromatic imidazoline-2-selones.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Preparation of the ,3 -Homoselenocysteine Derivatives Fmoc- ,3hSec(PMB)-OH and Boc- ,3hSec(PMB)-OH for Solution and Solid-Phase-Peptide Synthesis and SelenoligationHELVETICA CHIMICA ACTA, Issue 9 2007Oliver Flögel Abstract The title compounds, 4 and 7, have been prepared from the corresponding , -amino acid derivative selenocystine (1) by the following sequence of steps: cleavage of the SeSe bond with NaBH4, p -methoxybenzyl (PMB) protection of the SeH group, Fmoc or Boc protection at the N-atom and Arndt,Eistert homologation (Schemes,1 and 2). A ,3 -heptapeptide 8 with an N-terminal ,3 -hSec(PMB) residue was synthesized on Rink amide AM resin and deprotected (,in air') to give the corresponding diselenide 9, which, in turn, was coupled with a ,3 -tetrapeptide thiol ester 10 by a seleno-ligation. The product ,3 -undecapeptide was identified as its diselenide and its mixed selenosulfide with thiophenol (Scheme,3). The differences between , - and , -Sec derivatives are discussed. [source] Development of odorless organosulfur reagents and asymmetric reaction using odorless thiolsHETEROATOM CHEMISTRY, Issue 5 2007Manabu Node Odorless organosulfur reagents were developed by increasing their molecular weights to suppress volatility. 1-Dodecanethiol (4), dodecyl methyl sulfide (5), p -heptylphenylmethanethiol (6), p -dodecylbenzenethiol (7), p -heptylbenzenethiol (8), 2-dodecyl-1,3-propanedithiol (11), p -octyloxyphenyl-methanethiol (18b), and p -octyloxybenzenethiol (19) are typical examples of the odorless thiols and sulfides. 6-Morpholinohexyl thiol (15), methyl 6-morpholinohexyl sulfide (16), and methyl 6-morpholinohexyl sulfoxide (17) were also developed as separable reagents from reaction products by facile acid-base extraction. In addition, p -tetramethylsilylphenylmethanethiol (18) and p -tetramethylsilylbenzenethiol (14) were synthesized as the odorless synthetic substitutes of benzyl mercaptan and benzenethiol, respectively. In a similar way, silylated diphenyl disulfide (26) and diselenide (27) were prepared as odorless disulfide and diselenide. Moreover, 10-sulfanylisoborneol (1) was found to be an excellent chiral odorless substitute of hydrogen sulfide in Michael addition. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:572,583, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20348 [source] Hydrolysis of an isolable selenoseleninate under acidic and alkaline conditionsHETEROATOM CHEMISTRY, Issue 4 2001Akihiko Ishii Acid-catalyzed hydrolysis of a selenoseleninate [TripSe(O)SeTrip](Trip = 9-triptycyl) in 2 M HClO4 -1,4-dioxane at room temperature yielded the selenenic acid (TripSeOH). Alkaline hydrolysis of TripSe(O)SeTrip gave the diselenide (TripSeSeTrip) and the seleninic acid (TripSeO2H), where air oxidations of the resulting selenol (TripSeH) and TripSeOH occur at a considerable rate. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:198,203, 2001 [source] Mode-selective stereomutation tunneling as compared to parity violation in hydrogen diselenide isotopomers 1,2,3H280Se2ISRAEL JOURNAL OF CHEMISTRY, Issue 3-4 2003Michael Gottselig We present quantitative calculations of the mode-selective stereomutation tunneling in the chiral hydrogen diselenide isotopomers X2Se2 with X = H, D, and T. The torsional tunneling stereomutation dynamics were investigated with a quasi-adiabatic channel quasi-harmonic reaction path Hamiltonian approach, which treats the torsional motion anharmonically in detail and all remaining coordinates as harmonic (but anharmonically coupled to the reaction coordinate). We also investigated the influence of the excitation of fundamental modes on the stereomutation dynamics and predict which modes should be promoting or inhibiting. Our stereomutation dynamics results and the influence of parity violation on these are discussed in relation to our recent investigations for the analogous molecules H2O2, HSOH, H2S2, and Cl2S2. The electronic potential energy barrier heights for the torsional motion of hydrogen diselenide are similar to those of HSOH, whereas the torsional tunneling splittings are similar to the corresponding values of HSSH. The ground-state torsional tunneling splittings calculated here for D2Se2 are of the same order as the parity-violating energy difference reported by Laerdahl and Schwerdtfeger (Phys. Rev. A 1999, 60, 4439), whereas for T2Se2 the corresponding tunneling splitting is about three orders of magnitude smaller. [source] Diphenyl diselenide protects against glycerol-induced renal damage in ratsJOURNAL OF APPLIED TOXICOLOGY, Issue 7 2009Ricardo Brandão Abstract In this study we evaluated the effect of diphenyl diselenide (PhSe)2 on glycerol-induced acute renal failure in rats. Rats were pre-treated by gavage every day with (PhSe)2 (7.14 mg kg,1) for 7 days. On the eighth day, rats received an intramuscular injection of glycerol (8 mL kg,1). Twenty-four hours afterwards, rats were euthanized and the levels of urea and creatinine were measured in plasma. Catalase (CAT), glutathione peroxidase (GPx), glutathione S -transferase (GST), , -aminolevulinate dehydratase (, -ALA-D) and Na+, K+ -ATPase activities and ascorbic acid levels were evaluated in renal homogenates. Histopathological evaluations were also performed. The results demonstrated that (PhSe)2 was able to protect against the increase in urea and creatinine levels and histological alterations in kidney induced by glycerol. (PhSe)2 protected against the inhibition in , -ALA-D, CAT and GPx activities and the reduction in ascorbic acid levels induced by glycerol in kidneys of rats. In conclusion, the present results indicate that (PhSe)2 was effective in protecting against acute renal failure induced by glycerol. Copyright © 2009 John Wiley & Sons, Ltd. [source] Oral administration of diphenyl diselenide potentiates hepatotoxicity induced by carbon tetrachloride in ratsJOURNAL OF APPLIED TOXICOLOGY, Issue 2 2009Cristina W. Nogueira Abstract Carbon tetrachloride (CCl4) is a model for studying free radical-induced liver injury and screening hepato-protective drugs. Numerous studies have reported the involvement of oxidative stress in CCl4 -induced liver damage and the hepato-protective effects mediated by different antioxidants. The present study examined the effects of diphenyl diselenide, (PhSe)2, on hepatotoxicity induced by CCl4 in rats. To this end, male Wistar rats received (PhSe)2 by oral route at the dosage of 31.2 mg/kg for one or two days. After the second day of treatment, rats received CCl4 orally in a single dose. The liver and kidney were utilized for determination of histopathology, biochemical [aspartate (ALT) and alanine (AST) aminotransferases, alkaline phosphatase (ALP), total bilirrubin (TB) and gamaglutamyl transferase (GGT)] and toxicological parameters [thiobarbituric reactive species (TBARS) levels, catalase activity, ascorbic acid, nonprotein thiols (NPSH) and aminolevulinate dehydratase (, -ALA-D) activity]. Repeated administration of (PhSe)2 caused a marked potentiation of hepatotoxicity induced by CCl4 exposure, as manifested by an increase in biochemical parameters (AST, ALT, ALP, GGT and BT) and severe alteration in histopathology. This study also demonstrated a potentiation of TBARS levels and a consequent depletion of important antioxidant defenses including catalase and ascorbic acid. Pre-treatment with a single dose of (PhSe)2 prevented the effect of strychnine, a substrate for CYPs, abolishing lethality in mice. This result indicates that (PhSe)2 prevented animal death, suggesting an activator action of (PhSe)2 in CYPs. This study clearly indicates that (PhSe)2 potentiated acute hepatic damage induced by CCl4. Copyright © 2008 John Wiley & Sons, Ltd. [source] Diphenyl diselenide protects against hematological and immunological alterations induced by mercury in miceJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2008Ricardo Brandão Abstract Mercury is a heavy metal that can cause a variety of toxic effects on the organism, such as hematological and immunological alterations. In the present investigation, deleterious effects of mercury-intoxication in mice and a possible protective effect of diphenyl diselenide (PhSe)2 were studied. Male adult Swiss albino mice received daily a pretreatment with (PhSe)2 (15.6 mg/kg, orally) for 1 week. After this week, mice received daily mercuric chloride (1 mg/kg, subcutaneously) for 2 weeks. A number of hematological (erythrocytes, leukocytes, platelets, hemoglobin, hematocrit, reticulocytes, and leukocytes differential) and immunological (immunoglobulin G and M plasma concentration) parameters were evaluated. Another biomarker of tissue damage, lactate dehydrogenase (LDH), was also determined. The results demonstrated that mercury exposure caused a reduction in the erythrocyte, hematocrit, hemoglobin, leukocyte, and platelet counts and an increase in the reticulocyte percentages. (PhSe)2 was effective in protecting against the reduction in hematocrit, hemoglobin, and leukocyte levels. (PhSe)2 ameliorated reticulocyte percentages increased by mercury. However, (PhSe)2 was partially effective in preventing against the decrease in erythrocyte and platelet counts. Immunoglobulin G and M concentrations and LDH activity were increased by mercury exposure, and (PhSe)2 was effective in protecting against these effects. In conclusion, (PhSe)2 was effective in protecting against hematological and immunological alterations induced by mercury in mice. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:311,319, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20242 [source] Voltage-dependent ebselen and diorganochalcogenides inhibition of 45Ca2+ influx into brain synaptosomesJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 3 2003M. B. Moretto Abstract By mediating the Ca2+ influx, Ca2+ channels play a central role in neurotransmission. Chemical agents that potentially interfere with Ca2+ homeostasis are potential toxic agents. In the present investigation, changes in Ca2+ influx into synaptosomes by organic forms of selenium and tellurium were examined under nondepolarizing and depolarizing conditions induced by high KCl concentration (135 mM) or by 4-aminopyridine (4-AP). Under nondepolarizing conditions, ebselen (400 ,M) increased Ca2+ influx; diphenyl ditelluride (40,400 ,M) decreased Ca2+ in all concentrations tested; and diphenyl diselenide decreased Ca2+ influx at 40 and 100 ,M, but had no effect at 400 ,M. In the presence of KCl as depolarizing agent, ebselen and diphenyl ditelluride decreased Ca2+ influx in a linear fashion. In contrast, diphenyl diselenide did not modify Ca2+ influx into isolated nerve terminals. In the presence of 4-AP (3 mM) as depolarizing agent, ebselen (400 ,M) caused a significant increase, whereas diphenyl diselenide and diphenyl ditelluride inhibited Ca2+ influx into synaptosomes. The results can be explained by the fact that the mechanism through which 4-AP and high K+ induced elevation of intracellular Ca2+ is not exactly coincident. The mechanism by which diphenyl ditelluride and ebselen interact with Ca2+ channel is unknown, but may be related to reactivity with critical sulfhydryl groups in the protein complex. The results of the present study indicate that the effects of organochalcogenides were rather complex depending on the condition and the depolarizing agent used. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:154,160, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10073 [source] Bis-(3-hydroxyphenyl) diselenide inhibits LPS-stimulated iNOS and COX-2 expression in RAW 264.7 macrophage cells through the NF- kB inactivationJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2009Kyung-Min Shin Abstract Objectives Previously, we reported that diaryl diselenide compounds have strong inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophages. In this study, we investigated the molecular mechanisms underlying NO suppression and prostaglandin E2 (PGE2) production by diaryl diselenide compounds, bis-(2-hydroxyphenyl) diselenide (DSE-A), bis-(3-hydroxyphenyl) diselenide (DSE-B), bis-(4-hydroxyphenyl) diselenide (DSE-C), dipyridyl diselenide (DSE-D) and diphenyl diselenide (DSE-E). Methods The effect of these compounds on NO suppression and PGE2 production was investigated in RAW 264.7 macrophages. Key findings Our data indicate that of the above, DSE-B most potently inhibits NO and PGE2 production, and that it also significantly reduces the releases of tumour necrosis factor (TNF)-,, interleukin(IL)-1, and IL-6. Consistent with these observations, DSE-B also reduced the protein levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), and the mRNA levels of iNOS, COX-2, TNF-,, IL-1, and IL-6. Furthermore, DSE-B inhibited LPS-induced nuclear factor-,B (NF-,B) activation, which was associated with the prevention of the inhibitor ,B-, (I,B-,) degradation and a subsequent reduction in nuclear p65 protein levels. Conclusions Taken together, our data suggest that the anti-inflammatory properties of DSE-B are due to reduction in the expression of iNOS, COX-2, TNF-,, IL-1, and IL-6 through the down-regulation of NF-,B binding activity. [source] Mechanisms involved in the antinociceptive effect caused by diphenyl diselenide in the formalin testJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2008Lucielli Savegnago This study investigated the mechanisms involved in the antinociceptive action induced by diphenyl diselenide ((PhSe)2) in the formalin test. Mice were pre-treated with (PhSe)2 by the oral route (0.1,100 mg kg,1), 30 min before formalin injection. To address some of the mechanisms by which (PhSe)2 inhibits formalin-induced nociception mice were treated with different drugs. The antinociceptive effect of (PhSe)2 was shown in the first and second phases of the formalin test. The antinociceptive effect caused by (PhSe)2 (10 mg kg,1, p.o.) was prevented by intrathecal injection of K+ channel blockers such as apamin and charybdotoxin (small- and large-conductance Ca2+ -activated K+ channel inhibitors, respectively) and tetraethylammonium (TEA, a non-selective voltage-dependent K+ channel inhibitor), but not glib-enclamide (an ATP-sensitive K+ channel inhibitor). The antinociceptive action caused by (PhSe)2 (10 mg kg,1, p.o.) was also blocked by a nitric oxide (NO) synthase inhibitor (N, -nitro- l -arginine, L-NOARG) and the soluble guanylate cyclase inhibitors 1H -[1,2,4]oxadiazolo[4,3- a]quinoxalin-1-one (ODQ) and methylene blue. These results suggest the participation of NO/cyclic GMP/Ca2+ and K+ channel pathways in the antinociceptive effect caused by (PhSe)2. [source] Microwave-Assisted Solvothermal Synthesis of Copper Indium Diselenide PowdersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2010Chung-Han Lee Copper indium diselenide (CuInSe2) powders were successfully synthesized using the microwave-assisted solvothermal process at 200°C within a short time. The reaction time for preparing single-phased CuInSe2 was significantly shortened with the developed microwave treatment. The microwave field enhanced the mobility of the reactants, thereby resulting in an accelerated reaction rate. CuSe was the major intermediate product during these reactions and the CuInSe2 phase was gradually formed as the reaction temperature and time were increased. The prepared powders exhibited plate-like and spherical shapes, and the fraction of plate was increased with increasing reaction time. The solvothermal route combined with the microwave heating system was found to significantly promote the formation of plate-like particles. [source] Influence of the stacking order on structural features of the Cu-In-Ga-Se precursors for formation of Cu(In,Ga)Se2 thin films prepared by thermal reaction of InSe/Cu/GaSe alloys to elemental Se vapor and diethylselenide gasPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 8 2006F.B. Dejene Abstract A novel partway for the fabrication of copper-indium (gallium) diselenide has been developed. This two-stage process consists of the formation of Cu-In-(Ga)-Se precursors and subsequent selenization to form CuIn(Ga)Se2. In this work, we have investigated and compared the possible interactions in Cu-In-Ga-Se systems, using sequentially stacked precursors premixed with Se, in order to get a better understanding of the Cu(In,Ga)Se2 thin film formation. Comparison of these SEM micrographs clearly revealed that the surface morphologies and hence surface roughness of the resulting Cu(In,Ga)Se2 absorber films were significantly influenced by the structure of the precursor films prior to selenization. XRD analyses revealed the presence of a graded CuIn1-xGaxSe structure, irrespective of the stacking order during the precursor formation step for samples selenized using elemental Se vapor. It was established that distinct from the case of using Se vapor, a single-phase Cu(In,Ga)Se2 films were obtained by diethylselenide (DESe) selenization from Cu-In-Ga metal precursors premixed Se irrespective of the stacking order during the precursor formation step. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Preface: phys. stat. sol. (c) 1/9PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 9 2004Andrew Leitch The Conference on Photo-responsive Materials took place at the Kariega Game Reserve in the Eastern Cape, South Africa from 25,29 February 2004. More than 60 delegates from 12 different countries participated in the four-day event. The purpose of the conference was to bring together scientists working on various aspects of photo-responsive materials, so as to stimulate this important field of solid state physics in Southern Africa. As may be seen from the list of papers appearing in these proceedings, there was much interest in copper indium diselenide as a thin film material for photovoltaic applications. Also worth mentioning were the valuable contributions on ZnO, GaN and other materials that are currently attracting attention worldwide. The conference program allowed sufficient time for interaction and exchanging of views. Being in a game reserve in the heart of the beautiful Eastern Cape, delegates were also taken on game drives and had the opportunity of taking a river cruise up the Kariega River to view the majestic fish eagle. The members of the academic program committee were: Vivian Alberts (Rand Afrikaans University), Danie Auret (University of Pretoria), Darrell Comins (University of the Witwatersrand), and Reinhardt Botha and Andrew Leitch (University of Port Elizabeth). All papers appearing in these proceedings underwent a strict reviewing process separate from the conference. We express our appreciation to the referees for their diligence in this important task. The conference was organized by the Department of Physics at the University of Port Elizabeth, under the auspices of the Condensed Matter Physics and Materials Science (CMPMS) subgroup of the South African Institute of Physics. It was sponsored by EMF Limited (UK), Sensors Unlimited Inc. (USA), and Carl Zeiss (Pty) Ltd. Special thanks must go to Dr Eunete van Wyk for her professional assistance in the preparation of these proceedings. [source] High-efficiency copper indium gallium diselenide (CIGS) solar cells with indium sulfide buffer layers deposited by atomic layer chemical vapor deposition (ALCVD)PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 7 2003N. Naghavi Abstract This paper presents optimization studies on the formation of indium sulfide buffer layers for high-efficiency copper indium gallium diselenide (CIGS) thin-film solar cells with atomic layer chemical vapour deposition (ALCVD) from separate pulses of indium acetylacetonate and hydrogen sulfide. A parametric study of the effect of deposition temperature between 160° and 260°C and thickness (15,30,nm) shows an optimal value at about 220°C for a layer thickness of 30,nm, leading to an efficiency of 16·4%. Analysis of the device shows that indium sulfide layers are characterised by an improvement of the blue response of the cells compared with a standard CdS-processed cell, due to a high apparent band gap (2·7,2·8,eV), higher open-circuit voltages (up to 665,mV) and fill factor (78%). This denotes high interface quality. Atomic diffusion processes of sodium and copper in the buffer layer are demonstrated. Copyright © 2003 John Wiley & Sons, Ltd. [source] Third generation photovoltaics: Ultra-high conversion efficiency at low costPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 2 2001Martin A. GreenArticle first published online: 5 APR 200 Since the early days of terrestrial photovoltaics, a common perception has been that ,first generation' silicon wafer-based solar cells eventually would be replaced by a ,second generation' of lower cost thin-film technology, probably also involving a different semiconductor. Historically, cadmium sulphide, amorphous silicon, copper indium diselenide, cadmium telluride and now thin-film polycrystalline silicon have been regarded as key thin-film candidates. Any mature solar cell technology seems likely to evolve to the stage where costs are dominated by those of the constituent materials, be they silicon wafers or glass sheet. It is argued, therefore, that photovoltaics is likely to evolve, in its most mature form, to a ,third generation' of high-efficiency thin-film technology. By high efficiency, what is meant is energy conversion values double or triple the 15,20% range presently targeted, closer to the thermodynamic limit of 93%. Tandem cells are the best known of such high-efficiency approaches, where efficiency can be increased merely by adding more cells of different bandgap to a cell stack, at the expense of increased complexity and spectral sensitivity. However, a range of other more ,paralleled' approaches offer similar efficiency to an infinite stack of tandem cells. These options are reviewed together with possible approaches for practical implementation, likely to become more feasible with the evolution of materials technology over the next two decades. Copyright © 2001 John Wiley & Sons, Ltd. [source] Similarities and differences between bis[2-(bromomethyl)phenyl] diselenide, bis[2-(chloromethyl)phenyl] diselenide and bis[2-(hydroxymethyl)phenyl] diselenideACTA CRYSTALLOGRAPHICA SECTION C, Issue 8 2009Alberth Lari The title compounds, C14H12Br2Se2, (I), C14H12Cl2Se2, (II), and C14H14O2Se2, (III), feature a diselenide bridge between two o -benzyl bromide [in (I)], two o -benzyl chloride [in (II)] or two o -benzyl alcohol units [in (III)]. In the molecular structure of (I) and in both independent molecules of (II), close contacts are observed between the halogen centres and the diselenide unit. In the case of modification (IIIa), strong hydrogen bonds between the ,OH groups dominate, whereas the molecular structures of modification (IIIb) and bis{2-[(dimethylamino)methyl]phenyl} diselenide, C18H24N2Se2, (IV), are comparable with those of (I) and (II). A correlation between the strength of the contacts and the angle between the benzene planes and the Se,Se units is found. [source] | |||||||||||||||||||||||||||||||