Characterization of castor oil based polyurethane films prepared with N-methyl-2-pyrrolidinone as a solvent

Molecular mobility in castor oil based polyurethane was investigated with thermally stimulated depolarization current (TSDC) measurements and alternating-current (ac) dielectric relaxation spectroscopy. Three peaks could be observed in TSDC thermograms from 173 to 373 K. The relaxation located at 213 K could be attributed to the change in the molecular chain due to the interaction between the isocyanate and the solvent, and it was well fitted with the Vogel-Fulcher-Tammann equation. The other two peaks were located at 274 and 365 K and could be attributed to interfacial polarization and space charge, respectively. (c) 2005 Wiley Periodicals, Inc.

In situ solid state oxidation reaction for La1-xSrxMnO3 (x=0, 0.1, 0.2 and 0.3) formation

In situ solid state oxidation reaction for an alternative La1-xSrxMnO3 (x = 0, 0.1, 0.2 and 0.3) formation is reported. Samples have been obtained by using strontium peroxide, lanthanum and manganese (III) oxide reagents. Strontium peroxide has induced the oxidation of Mn+3 to Mn+4. Lanthanum strontium-doped manganite was obtained without secondary phase formation. La0.825Sr0.175MnO3 showed two structural transitions. The first from 88 to 373 K and the second at 1073 K. which are explained by Jahn-Teller effect at low temperature and cation displacement at high temperature. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Structural and functional characterization of myotoxin I, a Lys49 phospholipase A(2) homologue from Bothrops moojeni (Caissaca) snake venom

Myotoxin-I (MjTX-I) was purified to homogeneity from the venom of Bothrops moojeni by ion-exchange chromatography on CM-Sepharose. Its molecular weight, estimated by SDS-PAGE, was 13,400 (reduced) or 26,000 (unreduced). The extinction coefficient (E-1.0 cm(1.0 mg/ml)) of MjTX-I was 1.145 at lambda = 278 nm, pH 7.0, and its isoelectric point was 8.2 at ionic strength mu = 0.1. When lyophilized and stored at 4 degrees C, dimeric, trimeric, and pentameric forms of the protein were identified by SDS-PAGE. This heterogeneous sample could be separated into three fractions by gel filtration on Sephadex 6-50. The fractions were analyzed by isoelectric focusing, immunoelectrophoresis, and amino acid composition, which indicated that heterogeneity was the result of different levels of self-association. Protein sequencing indicated that MjTX-I is a Lys49 myotoxin and consists of 121 amino acids (M-r = 13,669), containing a high proportion of basic and hydrophobic residues. It shares a high degree of sequence identity with other Lys49 PLA(2)-like myotoxins, but shows a significantly lower identity with catalytically active Asp49 PLA(2)s. The three-dimensional structure of MjTX-I was modeled based on the crystal structures of three highly homologous Lys49 PLA(2)-like myotoxins. This model showed that the amino acid substitutions are conservative, and mainly the beta-wing region, and the C-terminal extended random coil. MjTX-I displays local myotoxic and edema-inducing activities in mice, and is lethal by intraperitoneal injection, with an LD50 value of 8.5 +/- 0.8 mg/kg, In addition, it is cytotoxic to myoblasts/ myotubes in culture, and disrupts negatively charged liposomes. In comparison with the freshly prepared dimeric sample, the more aggregated forms showed significantly reduced myotoxic activity. However, the edema-inducing activity of MjTX-I was independent of molecular association. Phospholipase A(2) activity on egg yolk, as well as anticoagulant activity, were undetectable both in the native and in the more associated forms. His, Tyr, and Trp residues of the toxin were chemically modified by specific reagents. Although the myotoxic and lethal activities of the modified toxins were reduced by these treatments, neither its edema-inducing or Liposome-disrupting activities were significantly altered. Rabbit antibodies to native MjTX-I cross-reacted with the chemically modified forms, and both the native and modified MjTX-I preparations were recognized by antibodies against the C-terminal region 115-129 of myotoxin II from B. asper, a highly Lys49 PLA(2)-homologue with high sequencial similarity. (C) 2000 Academic Press.

Fluoride intake from regular and low fluoride dentifrices by 2-3-year-old children: Influence of the dentifrice flavor

This study evaluated the fluoride intake from dentifrices with different fluoride concentrations ([F]) by children aged 24-36 months, as well as the influence of the dentifrice flavor in the amount of fluoride ingested during toothbrushing. Thirty-three children were randomly divided into 3 groups, according to the [F] in the dentifrices: G-A (523 μgF/g), G-B (1,062 μgF/g) and G-C (1,373 μgF/g). Dentifrices A and B are marketed for children, while dentifrice C is a regular product. The amount of F ingested was indirectly obtained, subtracting the amount expelled and the amount left on the toothbrush from the amount initially loaded onto the brush. The results were analyzed by ANOVA, Tukey's test and linear regression analysis (p < 0.05). Children ingested around 60% of the dentifrice loaded onto the brush, but no significant differences were seen among the groups (p > 0.05). Mean daily fluoride intake from dentifrice for G-A, G-B and G-C was 0.022 a, 0.032 a and 0.061 b mg F/kg body weight, respectively (p < 0.01). There was a strong positive correlation (r = 0.86, p < 0.0001) between the amount of dentifrice used and the amount of fluoride ingested during toothbrushing. The results indicate the need for instructing children's parents and care givers to use a small amount of dentifrice (< 0.3 g) to avoid excessive ingestion of fluoride. The use of low-[F] dentifrices by children younger than 6 years also seems to be a good alternative to minimize fluoride intake. Dentifrice flavor did not influence the percentage of fluoride intake.

Prevalência de Streptococcus suis sorotipo 2: discussão da literatura brasileira

Streptococcus suis is considered worldwide as one of the pathogens of biggest health and economic impact in the swine industry. Among the serotypes described as zoonotic, serotype 2 is the most frequently isolated from diseased animals and humans in most countries. The study of the epidemiology of S. suis infections in Brazil is important and may help in the development of effective control measures. The aim of this study was to conduct a critical review of Brazilian literature, with support of the world literature, addressing the diagnosis of the agent and its prevalence in clinically ill animals and healthy carriers, especially regarding to the prevalence of the serotype 2 in the country.

Study of K beta X-ray emission spectroscopy applied to Mn((2-x))V((1+x))O4 (x=0 and 1/3) oxyspinel and comparison with XANES

Oxidation state and coordination of transition metal cations seems to be hard to assess when considering multiple cations, each one with different possible oxidation states. In fact, this is the case of the spineltype double oxides family. High resolution K beta X-ray fluorescence spectra were measured in Mn(2-x)V(1+4)O4 (x=0 and 1/3) spinels-type double oxides in order to determine the oxidation state and coordination of V and Mn cations. The relative intensity of radiative Auger effect KM2,3M4,5 to the total intensity and the integral absolute difference value were used as reference parameters for the characterization of Mn oxidation states. The coordination of Mn ions was inferred by the intensity of the K beta(5) line. In the case of V compounds, it was used as the intensity of the line K beta' relative to the total area of K beta region. The obtained results were further compared with X-ray absorption spectra analysis, showing good agreements regarding the oxidation state characterization. However, there were found some discrepancies in coordination, due to customary oversimplifications in the K beta(5) line origin. The obtained results might represent valuable and useful data for chemical scopes of characterizing spineltype oxides family. (C) 2013 Elsevier Ltd. All rights reserved.

Effects of P-MAPA immunomodulator on Toll-like receptor 2, ROS, nitric oxide, MAPKp38 and IKK in PBMC and macrophages from dogs with visceral leishmaniasis

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

Estudo normativo do R-2: teste não verbal de inteligência para crianças

This study presents the standardization of the R-2 Non Verbal Intelligence Test for Children conducted at the city of Assis – SP, Brazil, and compares it with the São Paulo city standardization. The sample was composed by 559 children, between 5 and 11 years old, half of each sex, students from Assis city, randomly selected according to their proportion in private and public schools. Results indicate differences between ages and school types, but not between sexes. Percentile norms were established for the total sample at each age. The comparison of Assis and São Paulo city children reveals significant differences and Assis' results slightly higher. The conclusion is that R-2 Test is appropriate to cognitive assessment of Assis children, suggesting the use of new norms for this region.