Rare Earth Doped SnO(2) Nanoscaled Powders and Coatings: Enhanced Photoluminescence in Water and Waveguiding Properties

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

nor-Lignans from the leaves of Styrax ferrugineus (Styracaceae) with antibacterial and antifungal activity

Chemical examination of the leaves of Styrax ferrugineus yielded 5-[3'-(β-D-glucopyranosyloxy)propyl]-7-methoxy-2-(3',4'-dime-thoxyphenyl) benzofuran, along with the known nor-lignans 5-(3'-hydroxypropyl)-7-methoxy-2-(3',4'-methylenedioxyphenyl) benzofuran, 5-(3'-hydroxypropyl)-7-methoxy-2-(3',4'-dimethoxyphenyl)benzofuran, 5-[3'-(β-D-glucopyranosyloxy)propyl]-7-methoxy-2-(3', 4'-methylenedioxyphenyl)benzofuran and the lignan, dihydrodehydrodiconiferyl alcohol. All arylpropanoids isolated showed antibacterial and antifungal activities. The structures of the isolates were established by spectroscopic analysis. (C) 2000 Elsevier Science Ltd.

Sistemas para liberação colônica: Uma alternativa para a veiculação de fármacos para efeito local ou sistêmico

Problems related to the systemic administration of drugs, such as biodistribution, difficulty of targeting, necessity of high doses to achieve adequate levels of the drug in specific sites, toxicity, and undesirable side effects have lead to the development of systems able to direct the drug to specific sites in the body. Among the possible organs to the targeting of drugs, the colon can be used for local and systemic therapies. By developing such systems some models have been tested, using pH dependent release, release controlled by enzymatic degradation, time controlled release systems and pressure controlled release systems. This review presents an overview of the colonic release of drugs and the strategies used to achieve such targeting.

Effect of Bacillus circulans D1 thermostable xylanase on biobleaching of eucalyptus kraft pulp

The alkalophilic Bacillus circulans D1 was isolated from decayed wood. It produced high levels of extracellular cellulase-free xylanase. The enzyme was thermally stable up to 60°C, with an optimal hydrolysis temperature of 70°C. It was stable over a wide pH range (5.5-10.5), with an optimum pH at 5.5 and 80% of its activity at pH 9.0. This cellulase-free xylanase preparation was used to biobleach kraft pulp. Enzymatic treatment of kraft pulp decreased chlorine dioxide use by 23 and 37% to obtain the same kappa number (κ number) and brightness, respectively. Separation on Sephadex G-50 isolated three fractions with xylanase activity with distinct molecular weights.

Optimization of xylanase biosynthesis by Aspergillus japonicus isolated from a Caatinga area in the Brazilian state of Bahia

The objective of this research was to investigate the potential of xylanase production by Aspergillus japonicus and to determine the effects of cultivation conditions in the process, aiming toward optimization of enzyme production. The best temperature, as well as the best carbon source, for biomass production was determined through an automated turbidimetric method (Bioscreen-C). The enzyme activity of this fungus was separately evaluated in two solid substrates (wheat and soybean bran) and in Vogel medium, adding other carbon sources. Temperature effects, cultivation time, and spore concentrations were also tested. The best temperature for enzyme and biomass production was 25°C; however, the best carbon source for growth (determined by the Bioscreen C) did not turn out to be a good inducer of xylanase production. Maximum xylanase activity was achieved when the fungus was cultivated in wheat bran (without the addition of any other carbon source) using a spore concentration of 1 × 107 spores/mL (25°C, pH 5.0, 120 h). A. japonicus is a good xylanase producer under the conditions presented in these assays. © 2006 Academic Journals.

Cardiovascular remodeling induced by passive smoking

Coronary heart disease (CHD) is the most common cause of death in many developed countries. The major risk factors for CHD are smoking, high blood pressure, diabetes, high cholesterol levels, and lack of physical activity. Importantly, passive smoke also increases the risk for CHD. The mechanisms involved in the effects of passive smoke in CHD are complex and include endothelial dysfunction, lipoprotein modification, increased inflammation and platelet activation. Recently, several studies have shown that exposure to tobacco smoke can result in cardiac remodeling and compromised cardiac function. Potential mechanisms for these alterations are neurohumoral activation, oxidative stress, and MAPK activation. Although the vascular effects of cigarette smoke exposure are well known, the effects of tobacco smoking on the heart have received less attention. Therefore, this review will focus on the recent findings as to the effects of passive smoking in acute and chronic phases of vascular and cardiac remodeling. © 2009 Bentham Science Publishers Ltd.

Fontes de carbono de baixo custo para a produção de xilanase termoestável por aspergillus niger

A strain of the flamentous fungus Aspergillus niger was isolated and shown to possess extracellular xylanolytic activity. These enzymes have biotechnological potential and can be employed in various industries. This fungus produced its highest xylanase activity in a medium made up of 0.1% CaCO3, 0.5% NaCl, 0.1% NH4Cl, 0.5% corn steep liquor and 1% carbon source, at pH 8.0. A low-cost hemicellulose residue (powdered corncob) proved to be an excellent inducer of the A. niger xylanolytic complex. Filtration of the crude culture medium with suspended kaolin was ideal for to clarify the extract and led to partial purifcation of the xylanolytic activity. The apparent molecular mass of the xylanase was about 32.3 kDa. Maximum enzyme activity occurred at pH 5.0 and 55-60oC. Apparent Km was 10.41 ± 0.282 mg/mL and Vmax was 3.32 ± 0.053 U/mg protein, with birchwood xylan as the substrate. Activation energy was 4.55 kcal/mol and half-life of the crude enzyme at 60oC was 30 minutes. Addition of 2% glucose to the culture medium supplemented with xylan repressed xylanase production, but in the presence of xylose the enzyme production was not affected.

A new tropane alkaloid and other constituents of Erythroxylum rimosum (Erythroxylaceae)

A new tropane alkaloid, named the 7β-acetoxy-3β,6β- dibenzoyloxytropane (1), was isolated from a methanol extract of Erythroxylum rimosum O.E. Schulz leaves. Other known compounds were detected, including quercetin, kaempferol-3-O-α-l-arabinofuranoside, (+)-catechin, epicatechin, quercetin-3-O-α-arabinofuranoside, quercetin-3-O-α- arabinopyranoside, quercetin-3-O-β-arabinopyranoside, quercetin-3-β- glucopyranoside, kaempferol, quercetin-3-O-β-galactopyranoside, β-sitosterol, α-amyrin, β-amyrin, and the ester derivatives of these two amyrins. Compound 1 exhibited weak inhibition of acetylcholinesterase. Structural identification was performed using IR, ESIHRMS and one- and two-dimensional NMR data analyses and confirmed by comparison with literature data. © 2013 Phytochemical Society of Europe.

Production, purification, and characterization of a major penicillium glabrum xylanase using brewer's spent grain as substrate

In recent decades, xylanases have been used in many processing industries. This study describes the xylanase production by Penicillium glabrum using brewer's spent grain as substrate. Additionally, this is the first work that reports the purification and characterization of a xylanase using this agroindustrial waste. Optimal production was obtained when P. glabrum was grown in liquid medium in pH 5.5, at 25 °C, under stationary condition for six days. The xylanase from P. glabrum was purified to homogeneity by a rapid and inexpensive procedure, using ammonium sulfate fractionation and molecular exclusion chromatography. SDS-PAGE analysis revealed one band with estimated molecular mass of 18.36 kDa. The optimum activity was observed at 60 °C, in pH 3.0. The enzyme was very stable at 50 °C, and high pH stability was verified from pH 2.5 to 5.0. The ion Mn2+ and the reducing agents β-mercaptoethanol and DTT enhanced xylanase activity, while the ions Hg2+, Zn2+, and Cu2+ as well as the detergent SDS were strong inhibitors of the enzyme. The use of brewer's spent grain as substrate for xylanase production cannot only add value and decrease the amount of this waste but also reduce the xylanase production cost. © 2013 Adriana Knob et al.

Development and Biotechnological Application of a Novel Endoxylanase Family GH10 Identified from Sugarcane Soil Metagenome

Metagenomics has been widely employed for discovery of new enzymes and pathways to conversion of lignocellulosic biomass to fuels and chemicals. In this context, the present study reports the isolation, recombinant expression, biochemical and structural characterization of a novel endoxylanase family GH10 (SCXyl) identified from sugarcane soil metagenome. The recombinant SCXyl was highly active against xylan from beechwood and showed optimal enzyme activity at pH 6,0 and 45°C. The crystal structure was solved at 2.75 Å resolution, revealing the classical (β/α)8-barrel fold with a conserved active-site pocket and an inherent flexibility of the Trp281-Arg291 loop that can adopt distinct conformational states depending on substrate binding. The capillary electrophoresis analysis of degradation products evidenced that the enzyme displays unusual capacity to degrade small xylooligosaccharides, such as xylotriose, which is consistent to the hydrophobic contacts at the +1 subsite and low-binding energies of subsites that are distant from the site of hydrolysis. The main reaction products from xylan polymers and phosphoric acid-pretreated sugarcane bagasse (PASB) were xylooligosaccharides, but, after a longer incubation time, xylobiose and xylose were also formed. Moreover, the use of SCXyl as pre-treatment step of PASB, prior to the addition of commercial cellulolytic cocktail, significantly enhanced the saccharification process. All these characteristics demonstrate the advantageous application of this enzyme in several biotechnological processes in food and feed industry and also in the enzymatic pretreatment of biomass for feedstock and ethanol production. © 2013 Alvarez et al.

Desempenho, composição física das carcaças e qualidade da carne de tourinhos Nelore e Canchim terminados em confinamento

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo das interações entre proteína NS1 do hRSV e flavonóides utilizando métodos biofísicos

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

Evolution of the Metazoan Mitochondrial Replicase

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

The presence of the NOS3 gene polymorphism for intron 4 mitigates the beneficial effects of exercise training on ambulatory blood pressure monitoring in adults

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

Lipid biomarkers in surface sediments from an unusual coastal upwelling area from the SW Atlantic Ocean

The coastal upwelling off Cabo Frio (SE Brazilian coast, SEBC) represents an exception to the world`s oceans since the majority of the upwelling areas are located in eastern boundary current systems. Cabo Frio represents an interesting area for investigation due to its tight physical-biological interaction and the importance of the region as a major fishery area in the SEBC. We analyzed a suite of lipid biomarkers to apportion the main sources of organic matter in surface sediments of the continental shelf off Cabo Frio, comparing the area to non-upwelling regions off the SEBC (shelf break off Cabo Frio and continental shelf off Ubatuba). During spring and summer (the upwelling period), diatoms are probably the major sources of polyunsaturated fatty acids (PUFAs) and C-28 sterols in surface sediments from Cabo Frio continental shelf. Sediments sampled in winter showed, in contrast, lower relative abundance of PUFAs and higher stanol/stenol ratio values. In deeper regions off Cabo Frio, elevated concentrations of alkenones, 24-methylcholest-5,22E-dien-3 beta-ol and 24-ethylcholest-5-en-3 beta-ol during the spring may be produced by prymnesiophytes or cryptophytes and cyanobacteria, respectively. In Ubatuba, the C-27 and C-28 sterols are likely derived from omnivorous salps and nanoflagellates. At non-upwelling areas, despite the increase in biomarker concentrations during spring and summer, lower concentrations of PUFAs, phytol and algal sterols than in shelf areas off Cabo Frio suggest the importance of the upwelling system to the rapid transfer of organic carbon to surface sediments. Our results suggest that spatial and temporal variability in organic matter production and deposition merits consideration for constraining the carbon budgets in the coastal region off Cabo Frio. (C) 2008 Elsevier Ltd. All rights reserved.