Zinc mediated azide-alkyne ligation to 1,5- and 1,4,5-substituted 1,2,3-triazoles

A mild method for regioselective formation of 1,5-substituted 1,2,3-triazoles is described. The zinc-mediated reaction works at room temperature and is successful across a wide range of azido/alkynyl substrates. Additionally, the triazole 4-position can be further functionalized through the intermediate aryl-zinc to accommodate a diverse three-component coupling strategy.

Bond-selective energy redistribution in the chemisorption of CH3D and CD3H on Pt{1 1 0}-(1 2): a first-principles molecular dynamics study

We have investigated the chemisorption of CH3D and CD3H on Pt{11 0}-(1 2) by performing first-principles molecular dynamics simulations of the recombinative desorption of CH3D (from adsorbed methyl and deuterium) and of CD3H (from adsorbed trideuteromethyl and hydrogen). Vibrational analysis of the symmetry adapted internal coordinates of the desorbing molecules shows that excitation of the single C– D (C–H) bond in the parent molecule is strongly correlated with energy excess in the reaction coordinate. The results of the molecular dynamics simulations are consistent with observed mode- and bond-specific reactivity measurements for chemisorption of methane and its isotopomers on platinum and nickel surfaces.

SHIMMER (1.0): a novel mathematical model for microbial and biogeochemical dynamics in glacier forefield ecosystems

SHIMMER (Soil biogeocHemIcal Model for Microbial Ecosystem Response) is a new numerical modelling framework designed to simulate microbial dynamics and biogeochemical cycling during initial ecosystem development in glacier forefield soils. However, it is also transferable to other extreme ecosystem types (such as desert soils or the surface of glaciers). The rationale for model development arises from decades of empirical observations in glacier forefields, and enables a quantitative and process focussed approach. Here, we provide a detailed description of SHIMMER, test its performance in two case study forefields: the Damma Glacier (Switzerland) and the Athabasca Glacier (Canada) and analyse sensitivity to identify the most sensitive and unconstrained model parameters. Results show that the accumulation of microbial biomass is highly dependent on variation in microbial growth and death rate constants, Q10 values, the active fraction of microbial biomass and the reactivity of organic matter. The model correctly predicts the rapid accumulation of microbial biomass observed during the initial stages of succession in the forefields of both the case study systems. Primary production is responsible for the initial build-up of labile substrate that subsequently supports heterotrophic growth. However, allochthonous contributions of organic matter, and nitrogen fixation, are important in sustaining this productivity. The development and application of SHIMMER also highlights aspects of these systems that require further empirical research: quantifying nutrient budgets and biogeochemical rates, exploring seasonality and microbial growth and cell death. This will lead to increased understanding of how glacier forefields contribute to global biogeochemical cycling and climate under future ice retreat.

Ionic Recognition by 7-Nitro-1,3,5-triaza Adamantane: First Thermodynamic Study

A thermodynamic study involving 7-nitro-1,3,5-triaza adamantane, 1, and its interaction with metal cations in nonaqueous media is first reported. Solubility data of 1 in various solvents were used to derive the standard Gibbs energies of solution, Delta G(s)degrees in these solvents. The effect of solvation in the different media was assessed from the Gibbs energy of transfer taking acetonitrile as a reference solvent. (1)H NMR studies of the interaction of 1 and metal cations were carried out in CD(3)CN and CD(3)OD and the data are reported. Conductance measurements revealed that this ligand forms lead(II) or zinc complexes of 1: 1 stoichiometry in acetonitrile. It also revealed a stoichiometry of two molecules of 1 per mercury(II) and two cadmiu (II) ions per molecule of 1. The addition of silver salt to 1 led to the precipitation of the silver-1 complex which was isolated and characterized by X-ray crystallography. At variance with conductance measurements in solution, in the solid state the X-ray structure show`s a 1:1 stoichiometry in the Hg(II) complex. The themiodynamics of complexation of 1 and these cations provide a quantitative assessment of the selective behavior of this ligand for ions of environmental relevance.

Reactions of 1,2.,5-thiadiazole 1,1-dioxide derivatives with nitrogen nucleophiles. Part IV. Addition of alpha-diamines

alpha-diamines, such as ethylendiamine and o-phenylendiamine, add to 3,4-aryl-disubstituted 1,2,5-thiadiazole 1,1-dioxides to give dihydropyrazines or quinoxalines, respectively and sulfamide. The new compound acenaphtho [5,6-b]-2,3-dihydropyrazine was synthesized and characterized. The addition of ethylendiamine to 3,4-diphenyl-1,2,5-thiadiazoline 1,1-dioxide gives 3,4-disubstituted thiadiazoildine 1,1-dioxide, dihydropyrazines, or pyrazines, depending on the reaction condition used. The reactions were followed by cyclic voltammetry and NMR spectroscopy which, in some cases, allowed the detection of the thiadiazolidine intermediate. Copyright (c) 2008 John Wiley & Sons, Ltd.

Perspective: LaGuardia Community College Newsletter Vol. 1, No. 5

A newsletter published periodically to keep the faculty, students, staff, and community informed about the activities taking place on the campus of LaGuardia Community College. Cover article: SONY SHIFT SCHEDULED SOON, SPOKESMAN SAYS. Other entries include: CUNY TEACHING EXCELLENCE AWARD TO PROFESSOR MILLER; CHILD CARE LEAVE ADOPTED BY BHE; NINETY SENIOR CITIZENS RECEIVE CERTIFICATES; COLLEGE COMMENCEMENT TO BE HELD AT QUEENS COLLEGE AUDITORIUM; DEAN PALMER TO SING AT SEPT. 16, COMMENCEMENT; FOUR MORE PARAPROFESSIONALS COMPLETE DEGREES.”

Avaliação da estabilidade fisico-química da solução de hipoclorito de sódio a 0,5% utilizada pela FarmaUSCS, e de sua eficácia bactericida sobre Staphylococcus aureus e Escherichia coli

A FarmaUSCS é um projeto de extensão do curso de Farmácia da Universidade Municipal de São Caetano do Sul, que tem por finalidade manipular e dispensar medicamentos para a comunidade, além de servir de campo de estágio e de desenvolvimento de projetos de pesquisa. O presente trabalho teve por objetivo avaliar a estabilidade físico-química da solução aquosa de hipoclorito de sódio a 0,5%, utilizada para a desinfecção de ambientes produtivos na FarmaUSCS, bem como sua eficácia como agente bactericida sobre Staphylococcus aureus e Escherichia coli. Para a estabilidade físico-química, amostras da solução foram submetidas a diferentes condições ambientais e determinado o teor de hipoclorito por iodometria. A eficácia do desinfetante foi realizada pela técnica da diluição em tubos. Em nenhuma das condições ambientais testadas, houve degradação do teor de hipoclorito de sódio. A solução aquosa de hipoclorito de sódio a 0,5% foi eficaz diante de S. aureus e E. coli, já a partir do tempo mínimo testado de 2,5 minutos de exposição.

Análise do padrão W3C / XForms 1.0

Internet. Desde a versão 2.0 do HTML, entretanto, pouco foi melhorado no modelo de formulários proposto. Ao mesmo tempo, as necessidades dos desenvolvedores e os requisitos dos usuários cresceram dramaticamente. O W3C apontou uma resposta para as necessidades levantadas, o padrão XForms. O padrão XForms visa substituir o modelo de formulários definido no HTML por um modelo que separa o propósito da apresentação, adicionando, desta forma, a característica de independência de plataforma. A proposta deste trabalho é analisar o padrão XForms em relação à utilização de formulários HTML tradicionais, e à outras soluções existentes para automação de formulários na Internet, utilizando para isto uma aplicação piloto que procure utilizar alguns dos principais recursos disponíveis no padrão. Os pontos fortes, pontos fracos, dificuldades e lições aprendidas capturadas durante o desenvolvimento da aplicação piloto formam uma base de conhecimento apresentada neste trabalho.

Web 2.0, dilemmas 1.0: essay on an evolving market

Today the Internet is entwined into our everyday society. From the beginning days in 1980 to today, the Internet has been evolving. The creator of the World Wide Web, Tim Berners-Lee, envisioned that the Internet would be a system with everything connected to everything. The web today is changing with new applications arriving from outside the previous channels of the megalithic software companies. Thousands of individual developers are creating micro-applications to enhance the earlier framework of the web. This revolution has been coined "Web 2.0". Many observers today are skeptical that Web 2.0 is really a revolution at all, but maybe is just a continuation of Berners-Lee's original concept. This paper examines, based on a critical literature review, the discussions taking place regarding Web 2.0.

Declínio da tecnologia WAP 1.0 no Brasil: o papel dos modelos de negócios

o surgimento dos telefones celulares foi uma grande revolução nas telecomunicações, pois as pessoas poderiam se comunicar de qualquer lugar, mesmo em movimento. No entanto, a grande demanda obrigou a criação de novos sistemas digitais de telefonia, com mais qualidade nas ligações, capacidade de transmissão de voz, dentre outros. Posteriormente, surgiu uma demanda que não queria apenas mais qualidade, mas também a disponibilização de serviços disponíveis a partir do celular. Isto originou o uso da tecnologia WAP. Focalizando o estudo no mercado brasileiro, a tecnologia WAP foi anunciada como a responsável por trazer a Internet utilizada nos computadores convencionais diretamente para o celular. Entretanto, diversos problemas relativos ao uso e custo desta tecnologia indicaram claras desvantagens da Internet no celular em comparação com a Internet convencional. Isto tomou a tecnologia W AP um fracasso de crítica no Brasil. Esta dissertação busca comprovar o fracasso da la versão da tecnologia W AP - W AP 1.0 - e a participação dos modelos de negócios utilizados na derrocada desta tecnologia no mercado brasileiro de telefonia celular.

7,7-dimetoxi-1,4,5,6-tetraclorobiciclo[2.2.1]heptan-5-en-2-endo-ol : um versátil reagente na síntese de 1,3-aminoálcoois e de ciclopentanóides quirais altamente funcionalizados

Este trabalho relata a síntese de uma série de novos ligantes quirais (+) e (-)-syn-1,3-aminoálcoois derivados do norbornano. Através da reação de transesterificação enzimática com a lípase da Candida rugosa em acetato de vinila do álcool racêmico 7,7-dimetoxi-1,4,5,6-tetraclorobiciclo[2.2.1]heptan-5-en-2-ol, (±)-3, foram obtidos os álcoois quirais (+)-3 e (-)-3 (Esquema 1). Através da reação de redução e descloração destes álcoois com Na0/NH3/etanol foram obtidos os respectivos álcoois (+)-4 e (-)-4 (Esquema 2). Os álcoois quirais (+)-4 e (-)-4 foram utilizados como produtos de partida para a síntese dos 1,3-aminoálcoois quirais (+)-9 e (-)-9 em 5 etapas. Deste modo, a partir destes aminoálcoois (9), foi possível sintetizar 12 novos compostos (Esquema 2), todos inétidos na literatura. Os 1,3-aminoálcoois 10, 11, 13, 14 e 15 foram empregados como catalisadores quirais na adição enantiosseletiva de ZnEt2 ao benzaldeído. Excelentes rendimentos e excessos enantioméricos (até 91%) foram obtidos. A relação entre a configuração absoluta do 1-fenilpropanol com a configuração do carbono ligado ao grupo hidroxila dos ligantes foi estudada e, de acordo, com a enantiosseletividade observada foi sugerido um mecanismo para a reação Os produtos com esqueleto ciclopentila são importantes compostos com potencial atividade biológica, fazendo parte da estrutura de prostaglandinas, agentes antitumorais e inibidores da glicosidase. Portanto, nós decidimos usar o acetato clorado quiral 2 para preparar ciclopentanóides quirais altamente funcionalizados. Para isso, o acetato clorado quiral 2 foi submetido à oxidação usando uma quantidade catalítica de RuCl3 anidro na presença de NaIO4 obtendo-se a dicetona 16 (Esquema 3). A dicetona 16 foi clivada com H2O2 em meio alcalino fornecendo os diácidos 17a e 17b, que foram esterificados in situ com excesso de CH2N2 para fornecer uma mistura do hidroxi e acetoxi diéster 18 e 19, respectivamente. A redução da mistura 18 e 19 ou da mistura 17a e 17b com BH3.THF fornece a lactona 20 com excelentes rendimentos.

Padronização de três ELISAs polivalentes com lipopolissacarídeos de cadeia longa dos sorotipos 1 e 5, 2, 3 e 7 ou 10 e 12 de Actinobacillus pleuropneumoniae

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

Oxidation of melatonin and its catabolites, N-1-acetyl-N (2)-formyl-5-methoxykynuramine and N-1-acetyl-5-methoxykynuramine, by activated leukocytes

N-1-acetyl-N-2-formyl-5-methoxykynuramine (AFMK) and N-1-acetyl-5-methoxykynuramine (AMK), two melatonin catabolites, have been described as potent antioxidants. We aimed to follow the kinetics of AFMK and AMK formation when melatonin is oxidized by phorbol myristate acetate (PMA) and lipopolysaccharide (LPS)-activated leukocytes. An HPLC-based method was used for AFMK and AMK determination in neutrophil and peripheral blood mononuclear cell cultures supernatants. Samples were separated isocratically on a C18 reverse-phase column using acetonitrile/H2O (25:75) as the mobile phase. AFMK was detected by fluorescence (excitation 340 nm and emission 460 nm) and AMK by UV-VIS absorbance (254 nm). Activation of neutrophils and mononuclear cells with PMA produces larger amounts of AFMK than activation with LPS, probably due to the lower levels of reactive oxygen species formation and myeloperoxidase (MPO) degranulation that occurs when cells are stimulated with LPS. The concentration of AMK found in the supernatant was about 5-10% (from 18-hr cultures) compared with AFMK. This result may reflect its reactivity. Indeed AMK, but not AFMK, is easily oxidized by activated neutrophils in a MPO and hydrogen peroxide-dependent reaction. In conclusion, we defined a simple procedure for the determination of AFMK and AMK in biological samples and demonstrated the capacity of leukocytes to oxidize melatonin and AMK.

Structural, electronic structure and magnetic studies of SmFe1-xNixO3 (x <= 0.5)

We present the structural, electronic structure and magnetic studies of Ni doped SmFeO3. The X-ray diffraction (XRD) studies confirm the single phase nature of the samples having orthorhombic Pbnm structure and the unit-cell volume is decreasing with the increase of Ni concentration. X-ray absorption spectroscopy (XAS) studies on O K. Fe L-3.2, Ni L-3.2 and Sm M-5.4 edges of SmFe1-xNixO3 (x <= 0.5) samples along with the reference compounds revealed the homo-valence state of Fe and Ni in these materials. From magnetization studies it has been observed the materials exhibit ferromagnetic and anti-ferromagnetic sub-lattices, which are strongly dependent on the thermo-magnetic state of the system. (C) 2010 Elsevier B.V. All rights reserved.