203 resultados para titrage calorimétrique isotherme (ITC)
Resumo:
O autismo apresenta uma alta herdabilidade e uma etiologia heterogênea, com o provável envolvimento de vários genes. Estudos recentes sugerem que características presentes nos pais de crianças com autismo apresentam paralelo com as apresentações de traços associados nos filhos. Este estudo avaliou 15 famílias de autistas, de Porto Alegre e região metropolitana, e controles. Foram utilizados quatro instrumentos de avaliação no estudo: dois avaliando as características nos filhos (ADI-R e Protocolo de Bosa) e dois aplicados aos pais (ITC e EDS). Os resultados deste estudo apontaram para a confirmação da agregação familiar de características fenotípicas herdadas independentemente. Apesar de diferirem dos resultados dos controles (pais de crianças com desenvolvimento típico), não comprovou-se a existência de uma diferença significativa na severidade de apresentações fenotípicas em pais de crianças autistas. Foi possível estabelecer a presença de uma configuração de características fenotípicas ligadas a aspectos do autismo em pais e crianças com autismo. Esta pesquisa aponta pistas para a existência de um padrão de herança dentro das famílias autistas.
Resumo:
A crescente utilização de recursos de informática e comunicação nas empresas, visando modernização, agilidade, redução de custos e outros, tem trazido diversos benefícios, mas tem também se tornado um enorme problema para o planeta. A quantidade de lixo eletrônico (e-waste) gerada pelos equipamentos de informática e comunicação tem dobrado a cada cinco anos, se tornando um dos principais focos de atenção nos últimos anos. O volume de lixo eletrônico gerado pelo descarte de equipamentos de informática e comunicação (TIC), já ultrapassa a marca de 50 milhões de toneladas por ano, o que equivale a oito vezes a produção total de resíduos da cidade de São Paulo. O mercado brasileiro total de eletrônicos é considerado o quinto do mundo, depois da China, Estados Unidos, Japão e Rússia. A produção total de lixo eletrônico no Brasil em 2011 foi de um milhão de toneladas e a parte referente a equipamentos de TIC foi estimada em 98 mil toneladas. Frente a este contexto este estudo visa contribuir para a expansão do conhecimento na gestão verde da cadeia de suprimentos (GSCM) aplicado à realidade empresarial brasileira de TIC. Especificamente pretende-se identificar quais fatores influenciam o processo de adoção e aplicação da gestão verde de TIC, em grandes empresas usuárias de TIC no Brasil, a partir dos modelos propostos por Molla (2008) e Molla e Coopers (2008). Desta forma buscou-se responder ao seguinte problema de pesquisa: quais fatores influenciam grandes empresas usuárias de tecnologia da informação e comunicação (TIC) no Brasil na adoção de conceitos de gestão de verde? Para isto, foi realizado estudo de caso em seis grandes empresas, todas lideres em seus setores, representando grandes áreas de serviços e manufatura. Como resultado final, foi proposto um novo modelo analítico, que pareceu mais adequado ao setor de serviços. O estudo também identificou que na gestão verde de TIC empresas manufatureiras tem prioridades diferentes das de serviço. Muitas vezes seus desafios operacionais são mais críticos em relação à sustentabilidade, que a gestão verde de TIC em si. Por outro lado, o estudo dos serviços prestados pelo setor público apesar dos grandes orçamentos anuais, apontou restrições quanto aos aspectos legais e deficiência de qualificação e capacitação de seus colaboradores como fatores limitantes para a implantação de programas de gestão verde mais abrangentes.
Resumo:
A proteinaceous trypsin inhibitor was purified from Crotalaria pallida seeds by ammonium sulphate fractionation, affinity chromatography on immobilized Trypsin-Sepharose and TCA precipitation. The trypsin inhibitor, named ITC, had Mr of 32.5 kDa by SDS-PAGE and was composed by two subunits with 27.7 and 5.6 kDa linked by disulphide bridges, a typical characteristic of Kunitz-Inhibitor family. ITC was stable until 50°C, and at 100°C its residual activity was of about 60%. Also, ITC was stable at pHs 2 to 12. The inhibition of trypsin by ITC was non-competitive, with a Ki of 8,8 x 10-7M. ITC inhibits weakly other serine proteinases such as chymotrypsin and elastase. The inhibition of papain (44% of inhibition), a cysteine proteinase was an indicative of the bi-functionality of ITC. In vitro assays against digestive proteinases from several Lepdoptera, Diptera and Coleoptera pests were made. ITC inhibited in 100% digestive enzymes of Ceratitis capitata (fruit fly), Spodoptera frugiperda and Alabama argillacea, the last one being a cotton pest. It also inhibited in 74.4% Callosobruchus maculatus (bean weevil) digestive enzymes, a Coleoptera pest. ITC, when added in artificial diet models, affected weakly the development of C. capitata larvae and it had a WD50 of 2.65% to C. maculatus larvae
Resumo:
This research is an interpretative analysis of the type participatory research, developed in a qualitative and quantitative use of the blog as a support to a specific discipline, in order to identify the potential evident from its use. The report discusses the changes that have occurred in contemporary society, relating to the development of information technologies and communication (ITC s), presents a brief review of the historical background of the Internet and its use as an aid to education, emphasizing some environments inserted media the Internet, focusing on the main blog - its concept, origin and categorization, and analyzes the concepts of using the blog from the dialogues with teachers and students of pedagogy course at the Federal University of Rio Grande do Norte. Started from the assumption that the use of technological resources, such as blogging, with strictly educational purposes, can extend the knowledge beyond the walls of the classroom, thus creating a dialogic and interactive environment. Using data collected through interviews, questionnaires and observation, we seek to understand the object of study as a supportive environment for the teaching of a subject, raising some theoretical and methodological questions about its application to educational practice, and possible contributions to the construction of knowledge. The results indicate that there are several capabilities that make the blog a space conducive to teaching and learning process, and relates the concepts of the study participants about their use, highlighting the most important places to be solved, so that teachers and students to take ownership of knowledge necessary for capacity building required by the contemporary social context, due to the advancement of science and technology.
Resumo:
Induzidos por uma mudança estrutural na dinâmica da sociedade internacional, muitos municípios, por meio do exercício da chamada paradiplomacia ou diplomacia federativa, vêm elaborando instrumentos de gestão municipal para captar recursos via experiências de Cooperação Técnica Internacional (CTI). Nesse contexto, o objetivo deste artigo é mapear conceitualmente o fenômeno de CTI, visando a facilitar sua compreensão e suas consequências práticas para a sociedade brasileira.
Resumo:
At present, few data are available on the prevalence and antifungal susceptibility of Candida parapsilosis complex isolates from HIV-infected individuals. The C. parapsilosis complex comprises three species, C. parapsilosis sensu stricto, C. metapsilosis and C. orthopsilosis. Fifteen of 318 Candida isolates were identified as members of the C. parapsilosis complex by PCR and restriction fragment length polymorphism (RFLP). The prevalence of C. parapsilosis complex isolates was 4.7 %, 2.2 % being identified as C. parapsilosis sensu stricto and 2.5% as C. metapsilosis, while no C. orthopsilosis was isolated. This is believed to be the first study that has identified isolates of C. metapsilosis obtained from the oral cavity of HIV-infected individuals. Antifungal susceptibility tests indicated that all the isolates were susceptible to amphotericin B (AMB), fluconazole (FLC), ketoconazole (KTC), itraconazole (ITC), voriconazole (VRC) and caspofungin (CASPO). Although isolates of C. parapsilosis sensu stricto and C. metapsilosis were susceptible to FLC, isolates of C. metapsilosis showed a tendency for higher MICs (>= 1.0 mu g ml(-1)). Based upon the frequency of candidiasis and the fact that certain isolates of the C. parapsilosis complex respond differently to FLC therapy, our data may be of therapeutic relevance with respect to susceptibility and potential resistance to specific antifungal agents. Our data suggest that C. metapsilosis can be a human commensal; its importance as a pathogen has yet to be confirmed.
Resumo:
We used dynamic light scattering (DLS), a steady-state fluorescence, time resolved fluorescence quenching (TRFQ), tensiometry, conductimetry, and isothermal titration calorimetry (ITC) to investigate the self-assembly of the cationic surfactant cetyltrimethylammonium sulfate (CTAS) in aqueous solution, which has SO42- as divalent counterion. We obtained the critical micelled concentration (cmc), aggregation number (N-agg), area per monomer (a(0)), hydrodynamic radius (R-H), and degree of counterion dissociation (alpha) of CTAS micelles in the absence and presence of up to 1 M Na2SO4 and at temperatures of 25 and 40 degrees C. Between 0.01 and 0.3 M salt the hydrodynamic radius of CTAS micelle R-H approximate to 16 angstrom is roughly independent on Na2SO4 concentration; below and above this concentration range R-H increases steeply with the salt concentration, indicating micelle structure transition, from spherical to rod-like structures. R-H increases only slightly as temperature increases from 25 to 40 degrees C, and the cmc decreases initially very steeply with Na2SO4 concentration up to about 10 mM, and thereafter it is constant. The area per surfactant at the water/air interface, a(0), initially increases steeply with Na2SO4 concentration, and then decrases above ca. 10 mM. Conductimetry gives alpha = 0.18 for the degree of counterion dissociation, and N-agg obtained by fluorescence methods increases with surfactant concentration but it is roughly independent of up to 80 mM salt. The ITC data yield cmc of 0.22 mM in water, and the calculated enthalpy change of micelle formation, Delta H-mic = 3.8 kJ mol(-1), Gibbs free energy of micellization of surfactant molecules, Delta G(mic) = -38.0 kJ mol(-1) and entropy T Delta S-mic = 41.7 kJ mol(-1) indicate that the formation of CTAS micelles is entropy-driven. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
This study aimed at determining the effect of kappa number, lignin and hexenuronic acid contents on oxygen stage performance. Industrial brown pulps produced by the ITC and KobudoMARI cooking technologies, of kappa number and HexA's contents varying in the range of 10-21.7 and 23.2-56.7 mmol/kg, respectively, were collected in a period of 6 months and delignified with oxygen under fixed conditions. Kappa number was fractionated into lignin and hexenuronic acid and each fraction correlated with oxygen stage performance. It was concluded that O-stage efficiency, selectivity and yield does not correlate significantly with kappa number, lignin or hexenuronic acid contents for the ITC and KobudoMARI pulps at 5% of significance.
Resumo:
Tuberculosis remains as one of the main cause of mortality worldwide due to a single infectious agent, Mycobacterium tuberculosis. The aroK-encoded M. tuberculosis Shikimate Kinase (MtSK), shown to be essential for survival of bacilli, catalyzes the phosphoryl transfer from ATP to the carbon-3 hydroxyl group of shikimate (SKH), yielding shikimate-3-phosphate and ADP. Here we present purification to homogeneity, and oligomeric state determination of recombinant MtSK. Biochemical and biophysical data suggest that the chemical reaction catalyzed by monomeric MtSK follows a rapid-equilibrium random order of substrate binding, and ordered product release. Isothermal titration calorimetry (ITC) for binding of ligands to MtSK provided thermodynamic signatures of non-covalent interactions to each process. A comparison of steady-state kinetics parameters and equilibrium dissociation constant value determined by ITC showed that ATP binding does not increase the affinity of MtSK for SKH. We suggest that MtSK would more appropriately be described as an aroL-encoded type II shikimate kinase. Our manuscript also gives thermodynamic description of SKH binding to MtSK and data for the number of protons exchanged during this bimolecular interaction. The negative value for the change in constant pressure heat capacity (ΔCp) and molecular homology model building suggest a pronounced contribution of desolvation of non-polar groups upon binary complex formation. Thermodynamic parameters were deconvoluted into hydrophobic and vibrational contributions upon MtSK:SKH binary complex formation. Data for the number of protons exchanged during this bimolecular interaction are interpreted in light of a structural model to try to propose the likely amino acid side chains that are the proton donors to bulk solvent following MtSK:SKH complex formation. © 2013 Rosado et al.
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Pós-graduação em Biofísica Molecular - IBILCE
Resumo:
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Resumo:
Pós-graduação em Doenças Tropicais - FMB
Resumo:
Pós-graduação em Doenças Tropicais - FMB