Isomers on the [H, S(2), Cl] potential energy surface: A high level investigation

This study reports a systematic state-of-the-art characterization of new sulfur-chlorine species on the [H, S(2), Cl] potential energy surface. Coupled cluster theory singles and doubles with perturbative contributions of connected triples, using the series of correlation consistent basis sets with extrapolations to the complete basis set limit (CBS), were employed to quantify the energetic quantities involved in the isomerization processes on this surface. The structures and vibrational frequencies are unique for some species and represent the most accurate investigation to date. These molecules are potentially a new route of coupling the sulfur and chlorine chemistries in the atmosphere, and conditions of high concentration of H(2)S (HS) like in volcanic eruptions might contribute to their formation. Also an assessment of the MP2/CBS approach relative to CCSD(T)/CBS provides insights on the expected performance of MP2/CBS on the characterization of polysulfides, and also of more complex systems containing disulfide bridges. (C) 2009 Elsevier B.V. All rights reserved.

Preparation and characterization of colloidal Ni(OH)(2)/bentonite composites

A conductive and electrochemically active composite material has been prepared by the combination of bentonite and nickel hydroxide precursor sol. This material exhibits the characteristic intercalation properties of the clay component and the electrochemical and optical properties of nickel hydroxide. The clay particles seem to induce the aggregation of nickel hydroxide, leading to the formation of a layer of alpha-Ni(OH)(2) exhibiting needle like morphology. The composite forms stable films and has been conveniently used for the preparation of modified electrodes exhibiting intercalation and electrochemical properties, thus providing an interesting material for the development of amperometric sensors. (C) 2008 Elsevier Ltd. All rights reserved.

Modulation of trans-to-cis photoisomerization and photoluminescence of 1,2-bis(4-pyridyl)ethylene or 4-styrylpyridine coordinated to fac-tricarbonyl(5-chloro-1,10-phenathroline)rhenium(I)

Photochemical and photophysical properties of fac-[Re(CO)(3)(Clphen)(trans-L)](+) complexes, Clphen = 5-chloro-1,10-phenathroline and L = 1,2-bis(4-pyridyl)ethylene, bpe, or 4-styrylpyridine, stpy, were investigated to complement the understanding of intramolecular energy transfer process in tricarbonyl rhenium(I) complexes having an electron withdrawing group attached to polypyridyl ligands. These new compounds were synthesized, characterized and the photoisomerization quantum yields were accurately determined by (1)H NMR spectroscopy. The true quantum yields for fac-[Re(CO)(3)(Clphen) (trans-bpe)](+) were constant (Phi = 0.55) at all investigated irradiation wavelengths. However, for fac-[Re(CO)(3)(Clphen)(trans-stpy)](+), similar true quantum yields were observed only at higher energy irradiation (Phi(313 nm) = 0.53 and Phi(365 nm) = 0.57), but it decreased significantly at 404 nm (Phi = 0.41). These results indicated different deactivation pathways for the trans-stpy complex photoisomerization. Quantum yields decreased as the (3)IL(trans-L) and (3)MLCT(Re -> NN) excited states become closer and the behavior was discussed in terms of the excited state energy gaps. Additionally, luminescence properties of photoproducts, fac-[Re(CO)(3)(Clphen)(cis-L)](+), were also investigated in different environments to analyze the relative energy of the (3)MLCT(Re -> Clphen) excited state for each compound. (C) 2011 Elsevier B.V. All rights reserved.

Polyaniline/layered zirconium phosphate nanocomposites: Secondary-like doped polyaniline obtained by the layer-by-layer technique

In the present work, nanocomposites of polyaniline (PANI) and layered alpha-Zr(HPO4)(2).H2O (alpha-ZrP) were prepared using two different approaches: (i) the in situ aniline polymerization in the presence of the layered inorganic material and (ii) the layer-by-layer (LBL) assembly using an aqueous solution of the polycation emeraldine salt (ES-PANI) and a dispersion of exfoliated negative slabs of alpha-ZrP. These materials were characterized spectroscopically using mainly resonance Raman scattering at four exciting radiations and electronic absorption in the UV-VIS-NIR region. Structural and textural characterizations were carried out using powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The polymer obtained by the in situ aniline polymerization is located primarily in the external surface of the inorganic material although aniline monomers were intercalated between alpha-ZrP interlayer regions before oxidative polymerization. Through resonance Raman spectroscopy, it was observed that the formed polymer has semiquinone units (ES-PANI) and also azo bonds (-N = N-), showing that this method results in a polymer with a different structure from the usual ""head-to-tail"" ES-PANI. The LBL assembly of pre-formed ES-PANI and exfoliated alpha-ZrP particles produces homogeneous films with reproducible deposition from layer to layer, up to 20 bilayers. Resonance Raman (lambda(0) = 632.8 nm) spectrum of PANI/ZrP LBL film shows an enhancement in the intensity of the polaronic band at 1333 cm(-1) (nu C-N center dot+) and the decrease of the band intensity at 1485 cm(-1) compared to bulk ES-PANI. Its UV-VIS-NIR spectrum presents an absorption tail in the NIR region assigned to delocalized free charge carrier. These spectroscopic features are characteristic of highly conductive secondary doped PANI suggesting that polymeric chains in PANI/ZrP LBL film have a more extended conformation than in bulk ES-PANI.

Electrostatic layer-by-layer deposition and electrochemical characterization of thin films composed of MnO(2) nanoparticles in a room-temperature ionic liquid

Thin films of MnO(2) nanoparticles were grown using the layer-by-layer method with poly (diallyldimetylammonium) as the intercalated layer. The film growth was followed by UV-vis, electrochemical quartz crystal microbalance (EQCM), and atomic force microscopy. Linear growth due to electrostatic immobilization of layers was observed up to 30 bilayers, but electrical connectivity was maintained only for 12 MnO(2)/PPDA bilayers. The electrochemical characterization of this film in 1-butyl-2,3-dimethyl-imidazolium (BMMI) bis(trifluoromethanesulfonyl)imide (TFSI) (BMMITFSI) with and without addition of a lithium salt indicated a higher electrochemical response of the nanostructured electrode in the lithium-containing electrolyte. On the basis of EQCM experiments, it was possible to confirm that the charge compensation process is achieved mainly by the TFSI anion at short times (<2 s) and by BMMI and lithium cations at longer times. The fact that large ions like TFSI and BMMI participate in the electroneutrality is attributed to the redox reaction that occurs at the superficial sites and to the high concentration of these species compared to that of lithium cations.

Human endogenous RNAs: Implications for the immunomodulation of Toll-like receptor 3

Toll-like receptors (TLRs), a family of mammalian receptors, are able to recognize nucleic acids. TLR3 recognizes double-stranded (ds)RNA, a product of the replication of certain viruses. Polyinosinic-polycytidylic acid, referred to as poly(I:C), an analog of viral dsRNA, interacts with TLR3 thereby eliciting immunoinflammatory responses characteristic of viral infection or down-regulating the expression of chemokine receptor CXCR4. It is known that dsRNA also directly activates interferon (IFN)-induced enzymes, such as the RNA-dependent protein kinase (PKR). In the present study, the mRNA expression of TLR3, CXCR4, IFN gamma and PKR was investigated in a culture of peripheral blood mononuclear cells (PBMCs) stimulated with poly(I:C) and endogenous RNA from human PBMCs. No cytotoxic effect on the cells or on the proliferation of CD3(+), CD4(+) and CD8(+) cells was observed. TLR3 expression in the PBMCs in the presence of poly(I:C) was up-regulated 9.5-fold, and TLR3 expression in the PBMCs treated with endogenous RNA was down-regulated 1.8-fold (p=0.002). The same trend was observed for IFN gamma where in the presence of poly(I:C) an 8.7-fold increase was noted and in the presence of endogenous RNA a 3.1-fold decrease was observed. In the culture activated with poly(1:C), mRNA expression of CXCR4 increased 8.0-fold and expression of PKR increased 33.0-fold. Expression of these genes decreased in the culture treated with endogenous RNA when compared to the culture without stimulus. Thus, high expression of mRNA for TLR3, IFN gamma, CXCR4 and PKR was observed in the presence of poly(I:C) and low expression was observed in the cells cultured with endogenous RNA. In conclusion, TLR3 may play major physiological roles that are not in the context of viral infection. It is possible that RNA released from cells could contain enough double-stranded structures to regulate cell activation. The involvement of endogenous RNA in endogenous gene expression and its implications in the regulation thereof, are still being studied, and will have significant implications in the future.

(1)H NMR spectroscopy as a tool to determine accurate photoisomerization quantum yields of stilbene-like ligands coordinated to rhenium(I) polypyridyl complexes

In this work, the use of proton nuclear magnetic resonance, (1)H NMR, was fully described as a powerful tool to follow a photoreaction and to determine accurate quantum yields, so called true quantum yields (Phi(true)), when a reactant and photoproduct absorption overlap. For this, Phi(true) for the trans-cis photoisomerization process were determined for rhenium(I) polypyridyl complexes, fac-[Re(CO)(3)(NN)(trans-L)](+) (NN = 1,10-phenanthroline, phen, or 4,7-diphenyl-1,10-phenanthroline, ph(2)phen, and L = 1,2-bis(4-pyridyl) ethylene, bpe, or 4-styrylpyridine, stpy). The true values determined at 365 nm irradiation (e. g. Phi(NMR) = 0.80 for fac-[Re(CO)(3)(phen)(trans-bpe)](+)) were much higher than those determined by absorption spectral changes (Phi(UV-Vis) = 0.39 for fac-[Re(CO)(3)(phen)(trans-bpe)](+)). Phi(NMR) are more accurate in these cases due to the distinct proton signals of trans and cis-isomers, which allow the actual determination of each component concentration under given irradiation time. Nevertheless when the photoproduct or reactant contribution at the probe wavelength is negligible, one can determine Phi(true) by regular absorption spectral changes. For instance, Phi(313) nm for free ligand photoisomerization determined both by absorption and (1)H NMR variation are equal within the experimental error (bpe: Phi(UV-Vis) = 0.27, Phi(NMR) = 0.26; stpy: Phi(UV-Vis) = 0.49, Phi(NMR) = 0.49). Moreover, (1)H NMR data combined with electronic spectra allowed molar absorptivity determination of difficult to isolate cis-complexes. (C) 2009 Elsevier B. V. All rights reserved.

New Molecular Species of Potential Interest to Atmospheric Chemistry: Isomers on the [H, S(2), Br] Potential Energy Surface

This work reports a state-of-the-art theoretical characterization of four new sulfur-bromine species and five transition states on the [H, S(2), Br] potential energy surface. Our highest level theoretical approach employed the method coupled cluster singles and doubles with perturbative contributions of connected triples, CCSD(T), along with the series of correlation-consistent basis sets and with extrapolation to the complete basis set (CBS) limit in the optimization of the geometrical parameters and to quantify the energetic quantities. The structural and vibrational frequencies here reported are unique and represent the most accurate investigation to date of these species. The global minimum corresponds to a skewed structure HSSBr with a disulfide bond; this is followed by a pyramidal-like structure, SSHBr, 18.85 kcal/mol above the minimum. Much higher in energy, we found another skewed structure, HSBrS (50.29 kcal/mol), with one S-Br dative-type bond, and another pyramidal-like one, HBrSS (109.80 kcal/mol), with two S-Br dative-type bonds. The interconversion of HSSBr into SSHBr can occur via a transfer of either the hydrogen or the bromine atom but involves a very high barrier of about 43 kcal/mol. These molecules are potentially a new route of coupling the sulfur and bromine chemistry in the atmosphere, and conditions of high concentration of H(2)S like in volcanic eruptions might contribute to their formation. We note that HSSBr can act as a reservoir molecule for the reaction between the radicals HSS and Br. Also, an assessment of the methods DFT/B3LYP/CBS and MP2/CBS relative to CCSD(T)/CBS provides insights on the expected performance of these methods on the characterization of polysulfides and also of more complex systems containing disulfide bridges.

Oxovanadium(IV) and (V) complexes of acetylpyridine-derived semicarbazones exhibit insulin-like activity

Reaction of 2-acetylpyridine semicarbazone (H2APS), 3-acetylpyridine semicarbazone (H3APS) and 4-acetylpyridine semicarbazone (H4APS) with [VO(acac)(2)] (acac = acetylacetonate) gave [VO(H2APS)(acac)(2)] (1), (VO(H3APS)(acac)(2)] (2) and [VO(4APS)(acac) (H2O)] center dot 1/2H(2)O (3). Oxidation of complex 1 in acetonitrile gave [VO2(2APS)] (4). The crystal structures of complexes 1 and 4 have been determined. Complexes 1-3 were able to enhance glucose uptake and to inhibit glycerol release from adipocytes, which indicate their potential to act as insulin-mimics. (C) 2008 Elsevier Ltd. All rights reserved.

Elevers uppfattningar av vad man bör uppnå efter avslutad kurs i Idrott och Hälsa A : En studie av två gymnasieskolor i årskurs 2 – ett elevperspektiv

The purpose of this work is to see if the students, on two separate high schools, understand what skills you should achieve after completing the course in physical education and health A 100 points. The entire study is based on a student perspective. In order to best answer the purpose, the questionnaire used in the "available groups" in schools. The questions for the work are: To what extent and how students perceive what they should achieve after completing the course in Sport and Health A?, Which is the goal, based on the curriculum in Physical Education, that students feel are important to achieve? and how do a comparison like between these two schools on the basis of what students perceive that they must achieve in Sport and Health A?The result shows that the main goal that finds support in the course objectives is an assertion; Has knowledge of what to eat to maintain or improve health, which over 90% of students had checked in. The least important goal was the claim 14; Know woods and fields and carry out outdoor activities, as 30% of students had checked in. The most important goal that does not find support in the course objectives is claim 10; to be reversed to the lessons, which was 88% in response rate among students. Here was the least important goal, claim 6; to be skilled in various ball games, which received 17% of student responses. The findings revealed that there is a clear health perspective in physical education in the studied groups at the two schools, one can also see that there is an uneven distribution of the elements included in the curriculum of Sport and Health A, and the outdoor life and dance is rare in the teaching of the groups studied at the two schools. Finally, it appeared that the lesson content and teaching are likely to have a significant role in student perceptions of course goals.

A avaliação de estagio no ensino de 2. grau

O presente trabalho, requisito complementar para a obtenção do grau de Mestre em Educação, visa sugerir formas adicionais de controle do trabalho escolar, no ensino de 2o grau profissionalizante. Apoia-se na legislação vigente para a análise de incoerencias que estariam a frustar os objetivos daquele nível de ensino e identifica o Estágio Orientado na Empresa como a etapa onde deveria se processar uma mais efetiva reavaliaçao do trabalho escolar. Como contribuição à solução da questao, propoe um modelo de avaliação para esse tipo de estágio, destinado ao seu acompanhamento e controle, de forma a fazer do mesmo, um efetivo instrumento de integração Escola-Empresa em prol da educação profissionalizante. O estudo está estruturado em duas partes. A primeira compõe-se de dois capítulos: o Capítulo I introduz o tema, ressalta os seus objetivos e justifica a sua escolha, acrescentando, ainda, algumas definições destinadas a imprimir maior clareza contextual ao desenvolvimento do trabalho; o Capítulo 2 trata de melhor delimitar o estudo, quando apresenta algumas considerações sobre as Funções da Escola, o Trabalho Escolar e o Estágio Orientado na Empresa. A segunda parte, tambem com dois capítulos (3 e 4), trata, no Capítulo 3, da caracterização das Escolas Técnicas Federais: discorre sobre algumas disfunções ali praticadas; inicia um estudo exemplificativo destinado à Introdução do referido modelo de avaliação, e situa a posiçao alcançada por aquelas escolas no tocante à implantaçao do denominado Serviço de Integração Escola-Empresa. O Capítulo 4 é a proposta propriamente dita de avaliação e controle do trabalho escolar através de Estágio Orientado na Empresa. São apresentados os fatores e os parâmetros da avaliação pretendida para, entao, discorrer sobre a metodologia de aplicação, com detalhamentos que vao desde a classificação das atividades e tarefas dos estágios, até a sua análise final com os conceitos e os·pareceres. Como parte complementar desta proposta, é sugerida a estruturação de um organismo funcional, à semelhança de um BANCO DE DADOS, destinado à metodização de aproveitamento dos registros do processo de avaliação para o proveito da açao pedagógica. Como referência justificadora desta proposta de alteraçao dos dispositivos de avaliação do estágio, -e apresentado um levantamento-pesquisa preliminar, em forma de diagnóstico, desenvolvido na escola que serviu de fonte para o referido estudo exemplificativo. Trata-se de uma amostra da situação encontrada e, bastante, para justificar as alterações propostas, além de fornecer subsidios orientadores à sua elaboração. Os anexos, em número de 5, contem os modelos propostos para os principais instrumentos de avaliação do Estágio, bem como as instruções adicionais destinadas ao aluno. A Bibliografia consultada apoia-se basicamente na legislação em vigor para o ensino de 2o grau.

3-Hydroxy-4, 5-dimethyl-2 (5 H)-furanone levels in fortified Madeira wines: Relationship to sugar content

The maturation of Madeira wines usually involves exposure to relatively high temperatures and humidity levels >70%, which affect the aroma and flavor composition and lead to the formation of the typical and characteristic bouquet of these wines. To estimate the levels of sotolon [3-hydroxy4,5-dimethyl-2(5 H )-furanone] and their behavior over time, 86 aged Madeira wines samples (1-25 years old), with different sugar concentrations, respectively, 90 g L-1 for Boal, 110 g L-1 for Malvazia, 25 g L -1 for Sercial, and 65 g L-1 for Verdelho varieties, were analyzed. Isolation was performed by liquid-liquid extraction with dichloromethane followed by chromatographic analysis by GC-MS. The reproducibility of the method was found to be 4.9%. The detection and quantification limits were 1.2 and 2.0 µgL-1, respectively. The levels of sotolon found ranged from not detected to 2000 µgL-1 for wines between 1 and 25 years old. It was observed that during aging, the concentration of sotolon increased with time in a linear fashion ( r ) 0.917). The highest concentration of sotolon was found in wines with the highest residual sugar contents, considering the same time of storage. The results show that there is a strong correlation between sotolon and sugar derivatives: furfural, 5-methylfurfural, 5-hydroxymethylfurfural, and 5-ethoxymethylfurfural. These compounds are also well correlated with wine aging. These findings indicate that the kinetics of sotolon formation is closely related with residual sugar contents, suggesting that this molecule may come from a component like sugar.

Biochemical and functional properties of a thrombin-like enzyme isolated from Bothrops pauloensis snake venom

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

Effect of insulin-like growth factor-1 during in vitro oocyte maturation and in vitro culture of bovine embryos

Avaliaram-se o efeito do IGF-I na maturação in vitro (MIV) (experimento I) e no desenvolvimento embrionário (DE) (experimento II) de oócitos bovinos fecundados in vitro, quanto às taxas de clivagem (TC), de blastocistos (TB) e de eclosão (TE). Para MIV, complexos cumulus-oócitos imaturos foram cultivados em meio TCM-199 suplementado com HEPES, bicarbonato e piruvato de sódio, aditivos, soro fetal bovino (meio B-199) e gonadotrofinas 14U/ml de PMSG e 7U/ml de hCG). Para o desenvolvimento embrionário, os oócitos/zigotos foram cultivados em meio B-199 com células epiteliais do oviduto bovino em suspensão sob óleo de silicone. As condições de cultivo in vitro para ambos os experimentos seguiram os tratamentos: 1- meio B-199 + 200 ng/ml IGF-I; 2- B-199 + 100 ng/ml IGF-I; 3- B-199 + 50 ng/ml IGF-I; 4- B-199 + 10 ng/ml IGF-I; 5- B-199 + 0 ng/ml IGF-I. Todas as culturas foram realizadas a 38,5° C em atmosfera com 5% de CO2 e os dados foram analisados pelo teste do qui-quadrado. No experimento I, não houve diferença (P>0,05) entre os tratamentos quanto às TC, TB e TE, quando o meio de MIV foi suplementado com IGF-I. No experimento II, a adição de IGF-I ao meio de DE resultou em aumento na TC (P<0,05) mas não influenciou a TB e a TE. A adição de 200 ng/ml de IGF-I ao meio DE melhorou a TC (71,1%) quando comparada com a TC dos grupos de 100 ng/ml de IGF-I (57,6%) ou controle (56,7%), entretanto não houve diferença quando comparada com a dos grupos de 50 ng/ml (69,4%) ou 10 ng/ml (73,1%) de IGF-I. Não houve efeito benéfico na adição de 10 a 200 ng/ml de IGF-I nos meios de MIV e de DE com relação ao desenvolvimento de embriões produzidos a partir de oócitos maturados e fecundados in vitro.

Mapeamento robótico 2,5-D com representação em grade de ocupação-elevação

This work introduces a new method for environment mapping with three-dimensional information from visual information for robotic accurate navigation. Many approaches of 3D mapping using occupancy grid typically requires high computacional effort to both build and store the map. We introduce an 2.5-D occupancy-elevation grid mapping, which is a discrete mapping approach, where each cell stores the occupancy probability, the height of the terrain at current place in the environment and the variance of this height. This 2.5-dimensional representation allows that a mobile robot to know whether a place in the environment is occupied by an obstacle and the height of this obstacle, thus, it can decide if is possible to traverse the obstacle. Sensorial informations necessary to construct the map is provided by a stereo vision system, which has been modeled with a robust probabilistic approach, considering the noise present in the stereo processing. The resulting maps favors the execution of tasks like decision making in the autonomous navigation, exploration, localization and path planning. Experiments carried out with a real mobile robots demonstrates that this proposed approach yields useful maps for robot autonomous navigation