Potential tuberculostatic agents: Micelle-forming copolymer poly(ethylene glycol)-poly(aspartic acid) prodrug with isoniazid

With the objective of obtaining slow-acting isoniazid derivatives, of potential use as chemoprophylactics or chemotherapeutics in tuberculosis, the micelle-forming copolymer of poly(ethylene glycol)-poly(aspartic acid) prodrug with isoniazid was synthesized. The derivative obtained was found to be active in Mycobacterium Il(tuberculosis culture, with a minimal inhibitory concentration (MIC) 5.6 times lower than that of the tuberculostatic drug.

Potential tuberculostatic agent: Micelle-forming pyrazinamide prodrug

Pyrazinamide was condensed with the poly(ethylene glycol)-poly(aspartic acid) copolymer (PEG-PASP), a micelle-forming derivative was obtained that was characterized in terms of its critical micelle concentration (CMC) and micelle diameter. The CMC was found by observing the solubility of Sudan III in Poly(ethylene glycol)-poly(pyrazinamidomethyl aspartate) copolymer (PEG-PASP-PZA) solutions. The mean diameter of PEG-PASP-PZA micelles, obtained by analyzing the dynamic light-scattering data, was 78.2 nm. The PEG-PASP-PZA derivative, when assayed for anti-Mycobacterium activity, exhibited stronger activity than the simple drug.

O enigmático problema das gigantes ricas em Lítio e as perspectivas com o satélite Kepler

Lithium (Li) is a chemical element with atomic number 3 and it is among the lightest known elements in the universe. In general, the Lithium is found in the nature under the form of two stable isotopes, the 6Li and 7Li. This last one is the most dominant and responds for about 93% of the Li found in the Universe. Due to its fragileness this element is largely used in the astrophysics, especially in what refers to the understanding of the physical process that has occurred since the Big Bang going through the evolution of the galaxies and stars. In the primordial nucleosynthesis in the Big Bang moment (BBN), the theoretical calculation forecasts a Li production along with all the light elements such as Deuterium and Beryllium. To the Li the BNB theory reviews a primordial abundance of Log log ǫ(Li) =2.72 dex in a logarithmic scale related to the H. The abundance of Li found on the poor metal stars, or pop II stars type, is called as being the abundance of Li primordial and is the measure as being log ǫ(Li) =2.27 dex. In the ISM (Interstellar medium), that reflects the current value, the abundance of Lithium is log ǫ(Li) = 3.2 dex. This value has great importance for our comprehension on the chemical evolution of the galaxy. The process responsible for the increasing of the primordial value present in the Li is not clearly understood until nowadays. In fact there is a real contribution of Li from the giant stars of little mass and this contribution needs to be well streamed if we want to understand our galaxy. The main objection in this logical sequence is the appearing of some giant stars with little mass of G and K spectral types which atmosphere is highly enriched with Li. Such elevated values are exactly the opposite of what could happen with the typical abundance of giant low mass stars, where convective envelops pass through a mass deepening in which all the Li should be diluted and present abundances around log ǫ(Li) ∼1.4 dex following the model of stellar evolution. In the Literature three suggestions are found that try to reconcile the values of the abundance of Li theoretical and observed in these rich in Li giants, but any of them bring conclusive answers. In the present work, we propose a qualitative study of the evolutionary state of the rich in Li stars in the literature along with the recent discovery of the first star rich in Li observed by the Kepler Satellite. The main objective of this work is to promote a solid discussion about the evolutionary state based on the characteristic obtained from the seismic analysis of the object observed by Kepler. We used evolutionary traces and simulation done with the population synthesis code TRILEGAL intending to evaluate as precisely as possible the evolutionary state of the internal structure of these groups of stars. The results indicate a very short characteristic time when compared to the evolutionary scale related to the enrichment of these stars

Influence of glass forming histories on the structural and thermal properties of tellurite glasses

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effects of glass-forming histories on the crystallization kinetic of the 20Li(2)O-80TeO(2) glass

In the present work, tellurite 20Li(2)O-80TeO(2) glasses were prepared with identical nominal composition under different glass-forming histories to produce a stressed and stress-free samples. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) techniques were used to study the effects of the glass-forming histories on the thermal and structural properties of these glasses. The gamma-TeO2 (metastable), alpha-TeO2 and alpha-Li2Te2O5 phases were identified during the controlled devitrification in these glasses. The mestastable character of the gamma-TeO2 phase was clearly observed in the glass under stress but this effect is not so clear in the stress-free glass. The gamma-TeO2 and alpha-TeO2 phases crystallizes during the initial stages of crystallization in both studied glasses while the alpha-Li2Te2O5 phase crystallize in the final stages of the crystallization. The activation energies and Avrami exponent were calculated for both studied glasses with different particle size leading to E-3 > E-2 > E-1 for stressed glass and E-3 > E-2 approximate to E-1 for stress-free glass, where E-1, E-2 and E-3 were associated to the gamma-TeO2, alpha-TeO2 and alpha-Li2Te2O5 phases, respectively. The observed distinct (n) over bar (1) < <(n)over bar>(2) < <(n)over bar>(3) in both glasses is an indicative that nucleation and growth takes place by more than one mechanism in the early stages of the crystallization. (C) 2011 Elsevier B.V. All rights reserved.

Lack of influence of the Schneiderian membrane in forming new bone apical to implants simultaneously installed with sinus floor elevation: an experimental study in monkeys

Aim: To describe the early healing processes around the implants installed after elevation of the sinus mucosa applying the lateral access technique without the use of grafting material.Material and methods: Immediately after the elevation of the maxillary sinus Schneiderian membrane by the lateral approach in eight monkeys, implants were installed without the use of grafting material. The healing of the tissue around the implants was evaluated after 4, 10, 20 and 30 days. Ground sections were prepared and analyzed histologically.Results: After 4 days of healing, the formation of coagulum and provisional matrix was documented within the elevated area. At 10-day interval, sprouts of woven bone were in continuity with the parent bone, and partly in contact with the implant surface at the base of the augmented area. While bone-to-implant contact increased after 20 and 30 days, the area underneath the Schneiderian membrane appeared reduced in volume and condensed toward the apex of the implants. The sinus mucosa was to some extent collapsed onto the implant surface and on the newly formed bone.Conclusions: The void initially occupied by the coagulum after sinus membrane elevation shrank substantially during the observation period. A lack of influence of the Schneiderian membrane in bone formation apical to implants was documented in the early phase of healing.

Psychotria hoffmansegiana (Willd ex Roem. & Schult.) Mull. Arg. and Palicourea marcagravii st. Hil. (Rubiaceae): potential for forming soil seed banks in a brazilian Cerrado

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oral Candida albicans isolates from HIV-positive individuals have similar in vitro biofilm-forming ability and pathogenicity as invasive Candida isolates

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

Effects of vacuum structure on neutron star

We study the equation of state for neutron matter using the Walecka model including quantum corrections for baryons and sigma mesons through a realignment of the vacuum. We next use this equation of state to calculate the radius, mass and other properties of rotating neutron star.

On the HBO mechanism of X-ray neutron star

We ascribe the 15-60 Hz Quasi Periodic Oscillation (QPO) to the periastron precession frequency of the orbiting accreted matter at the boundary of magnetosphere-disk of Xray neutron star (NS). Considering the relativistic motion mechanism for the kHz QPO, that the radii of the inner disk and magnetosphere-disk of NS are correlated with each other by a factor is assumed. The obtained conclusions include: all QPO frequencies increase with increasing the accretion rate. The theoretical relations between 15-60 Hz QPO (HBO) frequency and the twin kHz QPOs are similar to the measured empirical formula. Further, the better fitted NS mass by the proposed model is about 1.9 solar masses for the detected LMXBs.

Validation of a mutant of the pore-forming toxin sticholysin-I for the construction of proteinase-activated immunotoxins

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

The membranotropic activity of N-terminal peptides from the pore-forming proteins sticholysin I and II is modulated by hydrophobic and electrostatic interactions as well as lipid composition

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Armazenagem em atmosfera modificada passiva de carambola azeda (Averrhoa carambola L.) cv. 'Golden Star'

Este trabalho avaliou o efeito das embalagens de polietileno de baixa densidade (PEBD), em diferentes espessuras, no prolongamento da vida útil pós-colheita de carambolas cv. 'Golden Star'. Os frutos foram colhidos fisiologicamente maturos, sendo selecionados pela ausência de defeitos e acondicionados nas embalagens de PEBD, constituindo os seguintes tratamentos: T1 - controle (sem embalagem); T2 - PEBD de 6 mim; T3 - PEBD de 10 mim; T4 - PEBD de 15 mim. Os frutos foram armazenados a 12 +/- 0,5 ºC e 95 +/- 5% de UR, por 45 dias, e mais 5 dias a 22 +/- 3ºC e 72 +/- 5% de UR. Vinte e quatro horas após a colheita e a cada nove dias, amostras eram retiradas do armazenamento refrigerado (AR), mantidas por 12 horas em condições ambiente (22 +/- 3ºC e 72 +/- 5% UR) e analisadas quanto à firmeza de polpa (FP), à perda de massa fresca, à coloração da epiderme, aos sólidos solúveis totais (SST), à acidez total titulável (ATT) e à ocorrência de distúrbios fisiológicos. Realizou-se também uma análise sensorial ao final do experimento. A maior firmeza de polpa e acidez total titulável, o melhor padrão de coloração, o menor conteúdo de sólidos solúveis totais, a ausência de manchas e podridões, e a melhor aceitabilidade pelos julgadores foram obtidos com os frutos acondicionados em embalagens de 10 mim.

Qualidade de carambolas azedas cv. 'Golden Star' tratadas com CaCl2 por imersão e armazenadas sob refrigeração

No presente trabalho, avaliou-se o efeito de diferentes concentrações de CaCl2 aplicadas na pós-colheita de carambolas cv. 'Golden Star, durante o armazenamento refrigerado (AR). Os frutos colhidos fisiologicamente maturos foram selecionados pela ausência de defeitos e imersos em soluções de CaCl2, em diferentes concentrações, em temperatura ambiente (22 °C) por 20 minutos. Após aplicação dos tratamentos T1 - controle (0% de CaCl2); T2 - CaCl2 a 1%; T3 - CaCl2 a 2%; T4 - CaCl2 a 3%, e T5 - CaCl2 a 4%, os frutos foram colocados em câmara frigorífica, por 35 dias, a 12 ± 0,5ºC e 95 ± 3%, e mais 3 dias a 22 ± 3°C e 72 ± 5% de umidade relativa (UR). 24 horas após a colheita e a cada sete dias, amostras foram retiradas da AR, mantidas por 12 horas em condições ambiente (22 ± 3°C e 72 ± 5% UR) e analisadas quanto ao teor de cálcio na polpa, perda de massa fresca, coloração da epiderme, firmeza de polpa (FP), sólidos solúveis totais (SST), acidez total titulável (ATT) e a ocorrência de distúrbios fisiológicos. Ao final do experimento, foi feita uma análise sensorial. Observou-se que os frutos imersos em solução de CaCl2 a 2% apresentaram menor perda de massa fresca e maior firmeza de polpa. As carambolas deste tratamento também não apresentaram manchas e podridões e foram preferidas pelos julgadores no teste de preferência. Os sólidos solúveis totais, a acidez total titulável e a coloração não apresentaram diferença estatística entre os tratamentos. Na análise de teores de cálcio adsorvido pelos frutos, determinou-se que quanto, maior a concentração da solução de CaCl2 aplicada, maior a concentração de cálcio presente na polpa.