Preparation of Fe-Cr-P-Co amorphous alloys by electrodeposition

The effects of bath composition and electroplating conditions on structure, morphology, and composition of amorphous Fe-Cr-P-Co deposits on AISI 1020 steel substrate, priorly plated with a thin Cu deposit, were investigated. The increase of charge density activates the inclusion of Cr in the deposit. However, above specific values of the charge density, which depend on the deposition current density, the Cr content in the deposit decreases. This Cr content decreasing is probably due to the significant hydrogen evolution with the increasing of deposition cur-rent and charge density. The effect of charge density on the content of Fe and Co is not clear. However, there is a tendency of increasing of Fe content and decreasing of Co content with the raising of current density. The Co is more easily deposited than the P, and its presence results in a more intense inhibition effect on the Cr deposition than the inhibition effect caused by P presence. Scanning electron microscope (SEM) analysis showed that Co increasing in the Fe-Cr-P-Co alloys analyzed does not promote the susceptibility to microcracks, which led to a good quality deposit. The passive film of the Fe-Cr-P-Co alloy shows a high ability formation and high protective capacity, and the results obtained by current density of corrosion, j(cor), show that the deposit with addition of Co, Fe31Cr11P28Co30, presents a higher corrosion resistance than the deposit with addition of Ni, Fe54Cr21P20Ni5. (C) 2004 Published by Elsevier B.V.

AMS and grain shape fabric of the Late Palaeozoic diamictites of the Southeastern Paran Basin, Brazil

Diamictites interbedded with marine shales and turbidites onlap the eastern border of the Parana Basin (Southern Brazil). These poorly sorted sediments were deposited during the Permo-Carboniferous glaciation, and their matrix-supported clasts show no preferred orientation. These massive rocks have been studied using anisotropy of magnetic susceptibility (AMS) and grain shape fabric. Hysteresis loops and thermomagnetic measurements show that AMS depends mostly on the paramagnetic clays, but fine ferromagnetic particles also contribute to the anisotropy. The coarse silt to sand grain preferred orientation study supports the use of AMS in describing the diamictite fabric, at least regarding the orientation of the foliation. AMS and grain shape data reveal subhorizontal to weakly inclined magnetic and grain shape foliation parallel to the regional bedding. The magnetic lineations are normally scattered within the foliation plane in agreement with the oblate AMS ellipsoids found in these rocks. Both fabric patterns are consistent with deposition by subaqueous mudflows that were resedimented downslope, with elastic supply from continental sources. The off-vertical grain shape foliation poles suggest that the deposition of diamictites was controlled by the depocentre topography of the Rio do Sul sub-basin.

Ceramic Primer Heat-Treatment Effect on Resin Cement/Y-TZP Bond Strength

The purpose of this study was to evaluate the effect of different heat-treatment strategies for a ceramic primer on the shear bond strength of a 10-methacryloyloxydecyl-dihydrogen-phosphate (MDP)-based resin cement to a yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) ceramic. Specimens measuring 4.5 x 3.5 x 4.5 mm(3) were produced from Y-TZP presintered cubes and embedded in polymethyl methacrylate (PMMA). Following finishing, the specimens were cleaned using an ultrasound device and distilled water and randomly divided into 10 experimental groups (n=14) according to the heat treatment of the ceramic primer and aging condition. The strategies used for the experimental groups were: GC (control), without primer; G20, primer application at ambient temperature (20 degrees C); G45, primer application + heat treatment at 45 degrees C; G79, primer application + heat treatment at 79 degrees C; and G100, primer application + heat treatment at 100 degrees C. The specimens from the aging groups were submitted to thermal cycling (6000 cycles, 5 degrees C/55 degrees C, 30 seconds per bath) after 24 hours. A cylinder of MDP-based resin cement (2.4 mm in diameter) was constructed on the ceramic surface of the specimens of each experimental group and stored for 24 hours at 37 degrees C. The specimens were submitted to a shear bond strength test (n=14). Thermal gravimetric analysis was performed on the ceramic primer. The data obtained were statistically analyzed by two-way analysis of variance and the Tukey test (alpha=0.05). The experimental group G79 without aging (7.23 +/- 2.87 MPa) presented a significantly higher mean than the other experimental groups without aging (GC: 2.81 +/- 1.5 MPa; G20: 3.38 +/- 2.21 MPa; G100: 3.96 +/- 1.57 MPa), showing no difference from G45 only (G45: 6 +/- 3.63 MPa). All specimens of the aging groups debonded during thermocycling and were considered to present zero bond strength for the statistical analyses. In conclusion, heat treatment of the metal/zirconia primer improved bond strength under the initial condition but did not promote stable bonding under the aging condition.

Vascular effects and electrolyte homeostasis of the natriuretic peptide isolated from Crotalus oreganus abyssus (North American Grand Canyon rattlesnake) venom

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The influence of fermentation time and the presence of salts in the rheology of the fermentation broth of a polysaccharide-producing bacteria free of soil

Rheological studies were carried out in the fermentation broth of a polysaccharide-producing microorganism free of soil. This microorganism was designated 4B. The bacteria 4B was inoculated in the fermentation broth, which consisted of a carbon source and mineral salts, and it was incubated in a rotating agitator at 30 degreesC for 72 h at 210 rpm. A rheometer of concentric cylinders equipped with a thermostatic bath was used and the readings were taken at 25 degreesC. A study was made of the influence of the fermentation time and the readings were made after 24, 48 and 72 h of incubation, using, separately, sucrose and glucose as carbon sources. The influence of the salt concentrations was determined in each carbon source; the salts used were NaCl, KCl and CaCl2 in the concentrations of 0.4%, 1.0%, 2.0% and 3.0%. It was observed that the fermentation broth behaves as a non-Newtonian fluid and it presents pseudoplastic behaviour. Calculations were made of the flow behaviour index (n) and the consistency index (k) of the samples after 24, 48 and 72 h of fermentation, and it was observed that the 72 h sample presented higher k and consequently higher apparent viscosity. of the carbon sources used, the sucrose presented higher viscous broths after 24 and 48 h, and the glucose after 72 h of fermentation. With relation to the effect of the addition of salts, the CaCl2 presented a higher influence on the viscosity of the fermentation broths. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Mebendazole treatment against Anacanthoras penilabiatus (Monogenea, Dactylogyridae) gill parasite of cultivated Piaractus mesopotamicus (Osteichthyes, Characidae) in Brazil. Efficacy and hematology

The present work evaluated the efficacy of mebendazole (MBZ) treatment against infections with the monogenean helminths Anacanthorus penilabiatus, gill parasites of young cultivated pacu, Piaractus mesopotamicus. A short-term bath treatment using 100, 200 and 500 mg MBZ/l of water for 10 and 30 min and a long-term-bath using 1, 10 and 100 mg MBZ/l of water for 24 h were utilized. Seven days after, fish were sacrificed and parasites counted. Concentrations of 500 and 200 mg MBZ/l for 10 and 30 min showed reduced efficacy (0.0 and 0.7%) and (14.2 and 11.0%), respectively. Nevertheless, 100 mg MBZ/l (10 min) and 10 nag MBZ/l (24 h) showed better efficacy (79.6 and 8 1.4%, respectively). Treatments for 24 h provoked increases in hematocrit, hemoglobin concentration and leukocyte number when compared to those untreated fish. Mebendazole treatments also provoked alterations in the defense blood cells especially in lymphocyte and thrombocyte numbers, when the fishes were submitted to 10 and 30 min baths.

Cryopreservation of Agaricus blazei in liquid nitrogen using dmso as cryoprotectant

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

A Semi-Continuous Analyzer for the Fluorimetric Determination of Atmospheric Formaldehyde

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cryopreservation at-80A degrees C of Agaricus blazei on rice grains

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

Enamel Defects in Maxillary Central Incisors of Infants With Unilateral Cleft Lip

Objective: To evaluate the presence of enamel alterations in deciduous maxillary central incisors of infants with unilateral cleft lip and alveolar ridge, with or without cleft palate, and to compare the occurrence and location of these alterations between the central incisor adjacent to the cleft and the contralateral incisor.Design: Intraoral clinical examination was performed after tooth cleaning and drying by a single examiner with the aid of a dental mirror, dental probe, and artificial light, with the child positioned on a dental chair. The defects were recorded in a standardized manner according to the criteria of the Modified Developmental Defects of Enamel Index.Setting: Hospital for Rehabilitation of Craniofacial Anomalies (HRAC) at Bauru, São Paulo, Brazil.Patients: One hundred one infants were evaluated. All were white, of both genders, aged 12 to 36 months and had at least two thirds of the crowns of maxillary incisors erupted.Results: Demarcated opacity was the most common defect at both cleft and noncleft sides, followed by diffuse opacity. The occurrence of hypoplasia at the cleft side was 11.8%. Most defects affected less than one third of the crown.Conclusion: The occurrence of enamel defects in deciduous maxillary central incisors of patients with unilateral cleft lip was 42.6%, mainly affecting the cleft side as to both number and severity.

Análise não destrutiva de pigmentos fotossintéticos em folhas de gergelim

The study aimed to relate the photosynthetic pigments, which were extracted in a laboratory and the readings were obtained by the portable chlorophyll meter ClorofiLOG 1030, by using mathematical models in sesame leaves. This work was conducted in December 2010, at Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Cotton, where feaf discs were removed to measure chlorophyll indexes through the portable chlorophyll meter. The same leaf discs were subjected to extraction of photosynthetic pigments, by using 5 mL dimethyl sulfoxide (DMSO), and were kept in a water bath at 70 degrees C for 30 min. Afterwards, an aliquot of 3 mL was removed to be read in a spectrophotometer at wavelengths of 470, 646 and 663 nm. Based on analytical results, mathematical models were adjusted by using the chlorophyll index to predict the levels of chlorophyll a, b, and total, and of carotenoids and their relationships. The study concluded that the portable chlorophyll meter ClorofiLOG 1030 can be used to estimate the concentration of photosynthetic pigments in sesame leaves with high precision, besides saving resources and time.

Thyroid State and Tolerance of Mammalian Myocardium to Hypoxia

Thyroid hormone is known to affect myocardial glycogen stores and thereby possibly limit anaerobic performance of mammalian cardiac muscle. Thyroid hormone administration (3,5,T-triiodo-L-thyroxine, 300 mu g/kg/day, sc) for 10 days decreased left ventricle (LV) glycogen concentration relative to euthyroid animals (2.78 +/- 0.46 vs. 4.28 +/- 0.29 mg/g of LV (mean +/- SEM)) while increasing the percent of V(1) myosin isozyi-ne, contractile activity and cardiac mass. In contrast, thyroidectomy increased myocardial glycogen stores (8.50 +/- 0.56 mg/g of LV) and shifted the myosin isozyme toward V(3), prolonged contractile activity and decreased LV mass. Thyroxine administration for 3, 7 and 10 days to thyroidectomized animals progressively decreased contractile duration and increased LV mass. Thyroxine administration for 3 or 7 days to thyroidectomized rats did not reduce glycogen stores (7.75 +/- 1.02 and 9.62 +/- 1.16 mg/g of LV, respectively), whereas myocardial glycogen declined to 3.30 +/- 0.58 mg/g of LV after 10 days of treatment. During hypoxia, cardiac muscle from thyroidectomized rats maintained greater active force and developed less contracture relative to euthyroid and, to a greater extent, than hyperthyroid rats. Removal of glucose from the bath decreased anaerobic performance and impaired recovery; however, myocardium from thyroidectomized rats remained more tolerant to hypoxia than the euthyroid group. Overall, the intrinsic LV glycogen content was positively correlated to anaerobic performance. These data demonstrate that the thyroid state profoundly affects myocardial growth, contractility and anaerobic performance of rat myocardium. Although energy demand may affect function during hypoxia, anaerobic substrate reserve (cardiac glycogen concentration) appears to be the primary factor determining tolerance to hypoxic stress. J. Exp. Zool. 311A:399-407, 2009. (C) 2009 Wiley-Liss, Inc.

Urea-Based Synthesis of Zinc Oxide Nanostructures at Low Temperature

The preparation of nanometer-sized structures of zinc oxide (ZnO) from zinc acetate and urea as raw materials was performed using conventional water bath heating and a microwave hydrothermal (MH) method in an aqueous solution. The oxide formation is controlled by decomposition of the added urea in the sealed autoclave. The influence of urea and the synthesis method on the final product formation are discussed. Broadband photoluminescence (PL) behavior in visible-range spectra was observed with a maximum peak centered in the green region which was attributed to different defects and the structural changes involved with ZnO crystals which were produced during the nucleation process.

Guanidine Affects Differentially the Twitch Response of Diaphragm, Extensor Digitorum Longus and Soleus Nerve-Muscle Preparations of Mice

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Temperature and relativity

We investigate whether inertial thermometers moving in a thermal bath behave as being hotter or colder. This question is directly related with the classical controversy concerning how temperature transforms under Lorentz transformations. Rather than basing our arguments on thermodynamical hypotheses, we use plain relativistic quantum field theoretical methods. © 1995.