Polymers are options as antimicrobials for skin protection, antifouling surfaces, and fabrics. Here we analyzed the interaction of polymers based on poly(methacrylate) (PMMA) and poly((dimethylamino ethyl) methacrylate) (PDMAEMA) with model membranes and bacteria. We used the homopolymers PMMA, PDMAEMA, and the diblock copolymer(s) prepared with different PMMAm:PDMAEMAn ratios (m/n). The interactions of PDMAEMA and PMMAm-b-PDMAEMAn with large unilamellar vesicles (LUVs) prepared with phosphatidylcholine and phosphatidylglycerol at different pHs, were analyzed by nuclear magnetic resonance (NMR), dynamic light scattering, and zeta potential. These polymers promoted LUVs leakage of a fluorescent probe (5,6-carboxyfluorescein) localized exclusively in the internal aqueous compartment. Interestingly, all copolymers exhibit a bell-shaped pH dependence for the polymer-induced LUVs leakage. The interaction of the positively charged polymers and the pH effect was also demonstrated using giant unilamellar vesicles. These copolymers inhibited bacterial growth in the micromolar range and can be used to prevent bacterial growth on surfaces. protection surfaces fabrics polymethacrylate poly methacrylate poly(methacrylate PMMA (PMMA polydimethylamino dimethylamino ethyl (PDMAEMA bacteria copolymer s copolymer(s PMMAmPDMAEMAn PMMAm PDMAEMAn m/n. mn m/n . m n (m/n) PMMAmbPDMAEMAn b (LUVs pHs NMR, NMR , (NMR) scattering potential 5,6carboxyfluorescein 56carboxyfluorescein carboxyfluorescein 5,6 5 6 (5,6-carboxyfluorescein compartment Interestingly bellshaped bell shaped polymerinduced polymer induced (m/n (NMR 6carboxyfluorescein 56 5,

RESUMO A Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp), do ponto de vista de quem chegou ao Brasil com bolsa e auxílio da Fapesp. Durante quinze anos, em posições funcionais, passa a conhecer a Fapesp por dentro. Descrevem-se as bases constitucionais, federais e estaduais, bem como os elementos infraconstitucionais que permitem à Fapesp ser uma das Agências de apoio à pesquisa mais distinguidas do mundo. O artigo descreve a mecânica de avaliação de projetos e programas. Os resultados dos investimentos da Fapesp em pesquisa científica produzem impactos intelectuais, econômicos e sociais em benefício do contribuinte paulista. Contudo, o patrimônio e o orçamento da fundação têm sido ameaçados repetidamente. Finalizando, o texto afirma que a manutenção da identidade da Fapesp requer o apoio de toda a sociedade paulista, pois a promoção da ciência e tecnologia traz benefícios que em muito excedem os seus investimentos.

ABSTRACT The Research Foundation of the State of São Paulo (Fapesp) as seen by a scientist who arrived in Brazil with a grant and a fellowship from the institution. For fifteen years, in functional positions, he got to know it from the inside. The constitutional bases, both at the federal and state levels, are described, as well as the infra-constitutional elements that allow Fapesp to be one of the world’s most distinguished research support agencies. This article describes the mechanics of evaluating projects and programs, and the results of Fapesp’s investments in scientific research in terms of the intellectual, economic, and social impacts for the benefit of São Paulo’s taxpayers. Harrowingly, however, the foundation’s assets and budget have been repeatedly threatened. Finally, the text states that maintaining Fapesp’s identity requires the support of the entire São Paulo society and the awareness that promoting science and technology generate benefits that far exceed the investments.

A reação em meio aquoso alcalino do dibrometo de 1,3-bis(4-cianopiridinium)propano, um composto constituído por dois anéis piridínicos conectados por uma ponte metilênica de três carbonos, gerou um novo composto, o 1-(4-ciano-2-oxo-1,2-diidro-1-piridil)-3-(4-ciano-1,2-diidro-1-piridil)propano. O resultado da reação é atribuído à proximidade do íon OH-, encapsulado entre os dois anéis piridínicos, fato este observado apenas em derivados bis-piridínicos conectados por pontes metilênicas de curta extensão, onde imperam efeitos de carga aliados à conformação.

The aqueous alkaline reaction of 1,3-bis(4-cyanopyridinium)propane dibromide, a reactant constituted of two pyridinium rings linked by a three-methylene bridge, generates a novel compound,1 -(4-cyano-2-oxo-1,2-dihydro-1-pyridyl)-3-(4-cyano-1,2-dihydro-1-pyridyl)propane. The reaction pathway is attributed to the proximity of the OH- ion inserted between two pyridinium moieties, which occurs only in bis(pyridinium) derivatives connected by short methylene spacers, where charge-conformational effects are important.

Hydrogels micro, sub-micro and nanoparticles are of great interest for drug encapsulation and delivery or as embolotherapic agents. In this work it is described the preparation of nano and sub-microparticles of pre-formed, high molecular weight and monomer free poly(N-vinyl-2-pyrrolidone) encapsulated inside the core of lecithin vesicles. The hydrogel particles are formed with a very narrow diameter distribution, of about 800 nm, and a moderate swelling ratio, of approximately 10.

The increasing demand for fatty acid-free lecithin required modifications in existing purification methods. In this technical note we describe a purification procedure with the following steps: a) homogenization and extraction of yolks obtained from fresh eggs with acetone, b) solubilization with ethanol and solvent elimination and c) repeated solubilization/precipitation with petroleum ether/acetone. This crude extract was chromatographed on neutral alumina, which was exhaustively washed with chloroform before elution with chloroform:methanol, allowing the sequential separation of fatty acids and lecithin. Chromatographic behavior and mass spectra of the product are presented. This fast procedure yields fatty acid-free lecithin at a competitive cost.

A Fortran77 program, SSPBE, designed to solve the spherically symmetric Poisson-Boltzmann equation using cell model for ionic macromolecular aggregates or macroions is presented. The program includes an adsorption model for ions at the aggregate surface. The working algorithm solves the Poisson-Boltzmann equation in the integral representation using the Picard iteration method. Input parameters are introduced via an ASCII file, sspbe.txt. Output files yield the radial distances versus mean field potentials and average molar ion concentrations, the molar concentration of ions at the cell boundary, the self-consistent degree of ion adsorption from the surface and other related data. Ion binding to ionic, zwitterionic and reverse micelles are presented as representative examples of the applications of the SSPBE program.