Electrochemical and photochemical conversion of [Ru3Ir(mu(3)-H)(CO)(13)] into [Ru3Ir(mu-H)(3)(CO)(12)]

Electrochemical and photochemical properties of the tetrahedral cluster [Ru3Ir(mu(3)-H)(CO)(13)] were studied in order to prove whether the previously established thermal conversion of this cluster into the hydrogenated derivative [Ru3Ir(mu-H)(3)(CO)(12)] also occurs by means of redox or photochemical activation. Two-electron reduction of [Ru3Ir(mu(3)-H)(CO)(13)] results in the loss of CO and concomitant formation of the dianion [Ru3Ir(mu(3)-H)(CO)(12)](2-). The latter reduction product is stable in CH2Cl2 at low temperatures but becomes partly protonated above 283 K into the anion [Ru3Ir(mu-H)(2)(CO)(12)](-) by traces of water. The dianion [Ru3Ir(mu(3)-H)(CO)(12)](2-) is also the product of the electrochemical reduction of [Ru3Ir(mu-H)(3)(CO)(12)] accompanied by the loss of H-2. Stepwise deprotonation of [Ru3Ir(mu-H)(3)(CO)(12)] with Et4NOH yields [Ru3Ir(mu-H)(2)(CO)(12)](-) and [Ru3Ir(mu(3)-H)(CO)(12)](2-). Reverse protonation of the anionic clusters can be achieved, e. g., with trifluoromethylsulfonic acid. Thus, the electrochemical conversion of [Ru3Ir(mu(3)-H)(CO)(13)] into [Ru3Ir(mu-H)(3)(CO)(12)] is feasible, demanding separate two-electron reduction and protonation steps. Irradiation into the visible absorption band of [Ru3Ir(mu3-H)(CO)(13)] in hexane does not induce any significant photochemical conversion. Irradiation of this cluster in the presence of CO with lambda(irr) > 340 nm, however, triggers its efficient photofragmentation into reactive unsaturated ruthenium and iridium carbonyl fragments. These fragments are either stabilised by dissolved CO or undergo reclusterification to give homonuclear clusters. Most importantly, in H-2-saturated hexane, [Ru3Ir(mu(3)-H)(CO)(13)] converts selectively into the [Ru3Ir(mu-H)(3)(CO)(12)] photoproduct. This conversion is particularly efficient at lambda(irr) > 340 nm.

Configurational preferences of two 1,2-diamine adducts of bis(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)cobalt(II)

The preparation, the IR and ligand field spectra and the structures of the mixed-ligand addition compounds [(N,N-dimethyl-1,2-diaminoethane)bis(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)cobalt(II)], [Co(thtf)2me2en], and [(N,N,N′,N′-tetramethyl-1,2-diaminoethane)bis(1-(2-thienyl)-4,4,4-trifluoro-1,3-butanedionato)cobalt(II)], [Co(thtf)2me4en], are reported. The structures were determined by single crystal X-ray diffraction analysis (monoclinic, space group P21/c, Z=4 with a=10.708(6), b=19.531(6), c=13.352(6) Å, β=111.64(10)°, R1=0.0642 and wR2=0.1719 for [Co(thtf)2(me2en)] and a=12.033(6), b=15.565(6), c=15.339(6) Å, β=92.57(6)°, R1=0.0612 and wR2=0.1504 for [Co(thtf)2me4en]). The structures are distorted octahedral and the shortest cobalt–cobalt separation distances are 5.388(2) Å in [Co(thtf)2me2en] and 8.675(3) Å in [Co(thtf)2me4en]. In both compounds the diamine molecules attain the gauche conformation. The U(Z,Z) conformation of the β-dione leads to a semi-chair conformation of the β-dionato chelate rings. The relative orientation of the groups attached to the β-dionato moiety depends on the extent of stereoelectronic effects the N-substitution of the diamine entails. In [Co(thtf)2me2en] the intraligand distance separating the trifluoromethyl carbon atoms is 5.281(18) Å while in [Co(thtf)2me2en] it increases to 8.338(9) Å. The cobalt–cobalt separation distance, the orientation of the chelate rings and the extent of N-substitution seem to affect hydrogen bonding. While in [Co(thtf)2me2en] inter- and intraligand hydrogen bonding is implicated, it is totally absent in [Co(thtf)2me4en].

Augmentation of insulin secretion by leucine supplementation in malnourished rats: possible involvement of the phosphatidylinositol 3-phosphate kinase/mammalian target protein of rapamycin pathway

A regimen of low-protein diet induces a reduction of pancreatic islet function that is associated with development of metabolic disorders including diabetes and obesity afterward. In the present study, the influence of leucine supplementation on metabolic parameters, insulin secretion to glucose and to amino acids, as well as the levels of proteins that participate in the phosphatidylinositol 3-phosphate kinase (PI3K) pathway was investigated in malnourished rats. Four groups were fed with different diets for 12 weeks: a normal protein diet (17%) without (NP) or with leucine supplementation (NPL) or a low (6%)-protein diet without (LP) or with leucine supplementation (LPL). Leucine was given in the drinking water during the last 4 weeks. As indicated by the intraperitoneal glucose tolerance test, LPL rats exhibited increased glucose tolerance as compared with NPL group. Both NPL and LPL rats had higher circulating insulin levels than controls. The LPL rats also showed increased insulin secretion by pancreatic islets in response to glucose or arginine compared with those observed in islets from LP animals. Glucose oxidation was significantly reduced in NPL, LP, and LPL isolated islets as compared with NP; but no alteration was observed for leucine and glutamate oxidation among the 4 groups. Western blotting analysis demonstrated increased PI3K and mammalian target protein of rapamycin protein contents in LPL compared with LP islets. A significant increase in insulin-induced insulin receptor substrate I associated PI3K activation was also observed in LPL compared with LP islets. These findings indicate that leucine supplementation can augment islet function in malnourished rats and that activation of the PI3K/maminalian target protein of rapamycin pathway may play a role in this process. (C) 2010 Elsevier Inc. All rights reserved.

Thermal and structural investigation of Er:YAl(3)(BO(3))(4) nanocrystalline powders

Pure Er:YAB (Er:YAl(3)(BO(3))(4)) nanometer-sized crystalline powder was produced from low cost chemical route, the polymeric precursor method. The initial homogeneous solutions were heat treated from 200 to 700A degrees C under oxygen atmosphere and the unique crystalline phase was synthesized at around 1150A degrees C. The thermal treatments and the initial stoichiometry play a very important role on the Er:YAB preparation. The thermal events of amorphous precursor resins and the crystallization process up to phase formation were investigated.

Synthesis, molecular structure and physicochemical properties of bis(3 `-azido-3 `-deoxythymidin-5 `-yl) carbonate

3`-Azido-3`-deoxythymidine (zidovudine, AZT), a synthetic analog of natural nucleoside thymidine, has been used extensively in AIDS treatments. We report here the synthesis. X-ray crystal and molecular structure, NMR, IR and Raman spectra and the thermal behavior of a novel carbonate of AZT [(AZT-O)(2)C=O], prepared by the reaction of zidovudine with carbonyldiimidazole. The carbonate compound, C(21)H(24)N(10)O(9), crystallizes in the tetragonal space group P4(1)2(1)2 with a = b = 15.284(1), c = 21.695(1) angstrom, and Z = 8 molecules per unit cell. It consists of two AZT moieties of closely related conformations which are bridged by a carbonyl group to adopt a folded Z-like shape. (C) 2010 Elsevier B.V. All rights reserved.

Synthesis, characterization and biological analysis of the complex [VO(Hdhp)(2)] (H(2)dhp=2,3-dihydroxypyridine)

A new vanadium (IV) complex with the monoanion of 2,3-dihydroxypyridine (H(2)dhp), or 3-hydroxy-2(1H)-pyridone, was synthesized, characterized by physicochemical techniques and tested biologically. The EPR data for the [VO(Hdhp)(2)] complex in DMF are: g(x) = 1.9768, g(y) = 1.9768 and g(z) = 1.9390; A values (10(-4) cm(-1)): A(x), 59.4; A(y//), 59.4; A(z), 171.0. The vV=O band in the IR spectrum of the complex is at 986 cm(-1). The complex is paramagnetic, with mu(eff) = 1.65 BM (d(1), spin-only) at 25 degrees C. The irreversible oxidation process [V(V)/V(IV)] of the [VO(Hdhp)(2)] complex, as revealed in a cyclic voltammogram, occurs at 876 mV. The calculated molecular structure of [VO(Hdhp)(2)] shows the vanadium(IV) center in a distorted square pyramidal environment, with the oxo ligand in the apical position and the oxygen donor atoms of the Hdhp ligands in the basal positions. The ability of [VO(Hdhp)(2)] to mimic insulin, and its toxicity to hepato-biliary functions, were investigated in streptozotocin-induced diabetic rats and it was concluded that the length of treatment and the amount of [VO(Hdhp)(2)] administered were effective in reducing experimental diabetes.

Avaliação de um serviço de atenção primária à saúde: características do rastreamento do câncer de colo de útero em usuárias de 20 a 59 anos

o artigo descreve o programa de rastreamento de câncer de colo de útero em uma população de mulheres de 20-59 anos, usuárias de um serviço de Atenção Primária à Saúde (APS), em Porto Alegre. Esta coorte histórica de 5 anos foi constituída usando os registros de família de três unidades do Serviço de Saúde Comunitária do Grupo Hospitalar Conceição, em Porto Alegre, Brasil. O estudo caracteriza a associação entre a detecção de hipertensão, diabetes, depressão e ansiedade nestas mulheres, e as freqüências de sua captação e adesão ao programa de rastreamento do câncer de colo de útero. As mulheres com 50 anos ou mais tiveram um risco relativo de 1,70 (IC95%=1,40-2,06) de não serem captadas pelo programa de rastreamento, quando comparadas com as mais jovens. Os resultados sugerem a necessidade de intensificar o rastreamento de rotina às mulheres de 50 anos ou mais. A captação e a adesão de usuárias poderiam ser usadas como indicadores da qualidade do processo de trabalho. São necessários novos estudos para o estabelecimento de inferência causal e para definir a captação e a adesão como indicadores da qualidade do processo de trabalho em Atenção Primária à Saúde.

Áreas contaminadas (parte 3)

O primeiro case de corresponsabilidade jurídica foi protagonizado pelo banco Fleet Factors, que teve de arcar com prejuízos decorrentes da contaminação de uma tecelagem, conta Mario Monzoni, coordenador do FGVces

Personagem: Homem nobre 3

Dois arquivos, um no formato PNG e outro em formato SVG. Dimensão: 398x735px.

Relatório de estágio pedagógico na Escola Básica dos 2º e 3º Ciclos Dr. Horácio Bento de Gouveia

O propósito deste trabalho é relatar e analisar criticamente todas as atividades desenvolvidas ao longo do estágio pedagógico realizado na Escola Básica dos 2º e 3º Ciclos Dr. Horácio Bento de Gouveia, no ano letivo 2011/2012. A prática letiva implicou a gestão permanente do processo de ensino-aprendizagem durante as fases de pré-impacto, impacto e pós-impacto. A conveniente interação entre estas três fases permitiu uma otimização da intervenção pedagógica. A avaliação foi uma temática a atribuir especial enfoque, dado o seu papel regulador das práticas pedagógicas e a função que assume ao nível da certificação das aprendizagens realizadas e das competências desenvolvidas. As assistências às aulas permitiram-nos, ganhar competências no papel de observadores e de observados. A atividade de intervenção na comunidade escolar consubstanciou-se na “Eco-aula”. Articulámos a nossa intervenção com o projeto “Eco-escolas” e lecionámos uma aula para toda a comunidade envolvida no 3º ciclo, cujo tema nuclear foi a ecologia e a sua importância no mundo atual não desvirtuado as consequências que as ações de cada um de nós acarretam para o bom funcionamento do planeta. No que concerne ao capítulo das atividades de integração no meio, interviemos no âmbito da direção de turma que implicou a caracterização da turma e o estudo de caso a um aluno com necessidade educativas especiais. Dentro deste capítulo inclui-se também a ação de extensão curricular que designámos “O Acampamento - Planear, executar e controlar uma atividade”. As ações científico-pedagógicas (individual e coletiva) trataram do valor educativo dos Desportos de Adaptação ao Meio no seio escolar. Neste capítulo explorou-se a pertinência do modelo taxonómico das atividades desportivas proposto por Almada et al. (2008) no processo de seleção das matérias de ensino a serem abordadas.

Anti-Helicobacter pylori activity and oxidative burst inhibition by the naphthoquinone 5-methoxy-3,4-dehydroxanthomegnin from Paepalanthus latipes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ação da β-1,3 glucana no sistema imune de camundongos com sepse por Candida albicans

The frequency of disseminated candidiasis caused by yeast has enhancing in intensive care unit. Despite the availability of new antifungal drugs, C. albicans sepsis mortality causes can be as high as 30-40%. So, it has been needed to looking for a new therapeutic medicament that helps in treatment and prevention of this infection. Previous data that demonstrated that particulated β-glucan stimulates the immune system and experiments of this work were conducted to investigating if β-glucan extracted from Saccharomices cerevisiae, could modified the evolution of mouse model C. albicans systemic infection. Balb/c mice with sepsis and β-1,3 glucan treated or not were analyzed the influence of β-1,3 glucan in survival of the animals, in the fungal burdens in kidney, in the production of urea and TNF even in the histopathology of kidney. The experiments shown that the infected animals a nd glucan treated had great survival (p<0,05), less unit form colony in kidney and normal levels of urea. In the kidney histopathology of not glucan treated animals it has seen more lesions when compared with treated animals. So we conclude that β-1,3 glucan could stimulate the immune system against disseminated C. albicans

Synthesis, characterization and biological analysis of the complex [VO(Hdhp)(2)] (H(2)dhp=2,3-dihydroxypyridine)

A new vanadium (IV) complex with the monoanion of 2,3-dihydroxypyridine (H(2)dhp), or 3-hydroxy-2(1H)-pyridone, was synthesized, characterized by physicochemical techniques and tested biologically. The EPR data for the [VO(Hdhp)(2)] complex in DMF are: g(x) = 1.9768, g(y) = 1.9768 and g(z) = 1.9390; A values (10(-4) cm(-1)): A(x), 59.4; A(y//), 59.4; A(z), 171.0. The vV=O band in the IR spectrum of the complex is at 986 cm(-1). The complex is paramagnetic, with mu(eff) = 1.65 BM (d(1), spin-only) at 25 degrees C. The irreversible oxidation process [V(V)/V(IV)] of the [VO(Hdhp)(2)] complex, as revealed in a cyclic voltammogram, occurs at 876 mV. The calculated molecular structure of [VO(Hdhp)(2)] shows the vanadium(IV) center in a distorted square pyramidal environment, with the oxo ligand in the apical position and the oxygen donor atoms of the Hdhp ligands in the basal positions. The ability of [VO(Hdhp)(2)] to mimic insulin, and its toxicity to hepato-biliary functions, were investigated in streptozotocin-induced diabetic rats and it was concluded that the length of treatment and the amount of [VO(Hdhp)(2)] administered were effective in reducing experimental diabetes.