No description available.

No / We describe a series of experiments designed to investigate the conformational transition that highly-branched polymers with ligands undergo when interacting with bacteria, a process that may provide a new sensing mechanism for bacterial detection. Fluorescent highly-branched poly(N-isopropyl acrylamide)s (HB-PNIPAM) were prepared by sequential self-condensing radical copolymerizations, using anthrylmethyl methacrylate (AMMA) and fluorescein-O-acrylate (FA) as fluorescent comonomers and 4-vinylbenzyl pyrrole carbodithioate as a branch forming monomer. Differences in reactivity necessitated to first copolymerize AMMA then react with FA in a separate sequential monomer feed step. Modifications of the chain ends produced vancomycin-functional derivatives (HB-PNIPAM-Van). The AMMA and FA labels allow probing of the conformational behaviour of the polymers in solution via fluorescence non-radiative energy transfer experiments. It was shown that interaction of this polymer's end groups with Staphylococcus aureus induced a macromolecular collapse. The data thus provide conclusive evidence for a conformational transition that is driven by binding to a bacterium. / EPSRC

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Yes / Branched poly(N-isopropylacrylamide) was functionalized with Amphotericin B (AmB) at the chain ends to produce an antifungal material. The polymer showed antifungal properties against AmB-sensitive strains of Candida albicans, Fusarium keratoplasticum and Aspergillus flavus (minimal inhibitory concentration ranged from 5 to 500 µg ml−1) but was not effective against an AmB resistant strain of C. albicans nor against Candida tropicalis. The polymer end groups bound to the AmB target, ergosterol, and the fluorescence spectrum of a dye used as a solvatochromic probe, Nile red, was blue shifted indicating that segments of the polymer became desolvated on binding. The polymer was less toxic to corneal and renal epithelial cells and explanted corneal tissue than the free drug. Also, the polymer did not induce reactive oxygen species release from peripheral blood mononuclear cells, nor did it cause a substantial release of the proinflammatory cytokines, tumour necrosis factor-α and interleukin-1β (at 0.5 mg ml−1). / Welcome Trust DBT Alliance (0998800/B/12/Z) and MRC (UK) (grant no. 16038)

No description available.

Resumo: Em 1997 o Departamento de DST/AIS e Hepatites Virais estruturou em todo Brasil uma rede de laboratórios para realizar o exame de Carga Viral Plasmática do HIV (CV) denominada Rede Nacional de Carga Viral. O exame quantifica o RNA do HIV no plasma do paciente infectado utilizando a metodologia do branched-DNA, um ensaio de amplificação do sinal luminescente, o qual utiliza uma plataforma de detecção. Atualmente, esta rede é reconhecida internacionalmente e realiza 520.000 exames/ano. No entanto, vários fatores podem influenciar o resultado do exame como integridade do RNA, volume de amostra disponível, método e plataforma utilizados. Assim, o Departamento de DST/AIDS e Hepatites Virais implantou um protocolo pré-analítico para ser utilizado em todo o território nacional. Entretanto, as regiões brasileiras são muito diferentes e alguns laboratórios não conseguem seguir este protocolo. O objetivo deste estudo foi (a) avaliar as diferentes condições de transporte e armazenamento das amostras utilizadas no teste de CV, (b) validar a utilização de volumes iniciais de plasma inferiores ao preconizado, (c) comparar plataformas de detecção e (d) metodologias disponíveis para a execução do exame. Os resultados mostraram que as amostras podem ser processadas em até 8 h sem perda ou degradação do RNA, volumes iniciais inferiores ao preconizado podem ser utilizado com perda de sensibilidade e, as duas plataformas disponíveis no Brasil são equivalentes para a execução do teste. Apesar de existirem outras metodologias para a realização do teste, os resultados podem ser diferentes mostrando a necessidade da utilização da mesma metodologia em todo Brasil / Abstract: The Department of the DST/AIDS and Viral Hepatitis implemented since 1997 a laboratory network in all Brazil to perform the HIV plasma viral load (PVL) test named Viral Load National Network as part of the attendance to infected patient. This exam quantify the HIV plasma RNA in infected patient using Branched-DNA methodology, a signal amplification nucleic acid probe assay, which use a detection platform. Nowadays this network has international appreciation and to execute 520.000 tests/year. However, several factors can alter the result of the test as RNA integrity, available sample volume, used method and detection platform. Then an optimized pre-analytic protocol was implanted by Department of the DST/Aids to be used in all national territory. However the Brazil regions are many different and some laboratories don't get lead this protocol. The goal of this study was (a) to evaluate the different transport and storage conditions of the samples used to the PVL test, (b) to valid the use of the lower plasma initial input in the exam, (c) to compare the detection platforms and (d) methods available to execution of the test. The results showed blood sample can be process in until 8h after collection without RNA loss or degradation, lower initial input can be used with loss of sensibility and the two detection platforms available in Brazil are equivalent. In spite of others methods are available to execution of test, the results can be distinct showing the importance of the all laboratories in Brazil used the same method / Orientador: Maria Inês de Moura Campos Pardini / Coorientador: Rejane Maria Tommasini Grotto / Banca: Emílio Carlos Curcelli / Banca: Paulo Inácio da Costa / Mestre

<html> <head> <meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"> </head> Let &Sigma;<em>_g</em> be a closed Riemann surface of genus <em>g</em>. Generalizing Ivan Smith's construction, for each <em>g</em> &ge; 1 and <em>h</em> &ge; 0 we construct an infinite set of infinite families of homotopic but pairwise non-isotopic symplectic surfaces inside the product symplectic manifold &Sigma;<em>_g</em> ×&Sigma;<em>_h</em>. In particular, we achieve all positive genera from these families, providing first examples of infinite families of homotopic but pairwise non-isotopic symplectic surfaces of even genera inside &Sigma;<em>_g</em> ×&Sigma;<em>_h</em>.

<html> <head> <meta http-equiv="Content-Type" content="text/html;charset=iso-8859-1"> </head> Let &Sigma;<em>_g</em> be a closed Riemann surface of genus <em>g</em>. Generalizing Ivan Smith's construction, for each <em>g</em> &ge; 1 and <em>h</em> &ge; 0 we construct an infinite set of infinite families of homotopic but pairwise non-isotopic symplectic surfaces inside the product symplectic manifold &Sigma;<em>_g</em> ×&Sigma;<em>_h</em>. In particular, we achieve all positive genera from these families, providing first examples of infinite families of homotopic but pairwise non-isotopic symplectic surfaces of even genera inside &Sigma;<em>_g</em> ×&Sigma;<em>_h</em>.

Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Emily Haymes, Florida State University, College of Human Sciences, Dept. of Nutrition, Food, and Exercise Science. Title and description from dissertation home page (viewed Feb. 26, 2004). Includes bibliographical references.