Confecção e caracterização físico-química de filmes compósitos autossustentáveis NaAlg-TiO2-WO3

A new self-sustainable film was prepared through the sol-gel modified method, previously employed in our research group; sodium alginate was used as the polymer matrix, along with plasticizer glycerol, doped with titanium dioxide (TiO2) and tungsten trioxide (WO3). By varying WO3 concentration (0,8, 1,6, 2,4 and 3,2 μmol) and keeping TiO2 concentration constant (059 mmol), it was possible to study the contribution of these oxides on the obtained films morphological and electrical properties. Self-sustainable films have analyzed by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XDR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and Electrochemical Impedance Spectroscopy (EIS). By the IR specters, it was possible identify the TiO2, and posteriorly WO3, addition has provided dislocation of alginate characteristics bands to smaller vibrations frequencies indicating an electrostatic interaction between the oxides and the polymer matrix. Diffractograms show predominance of the amorphous phase in the films. SEM, along with EDX, analysis revealed self-sustainable films showed surface with no cracks and relative dispersion of the oxides throughout the polymer matrix. From Impedance analysis, it was observe increasing WO3 concentration to 2,4 μmol provided a reduction of films resistive properties and consequent improvement of conductive properties

Commissural nucleus of the solitary tract is important for cardiovascular responses to caudal pressor area activation

The nucleus of the solitary tract (NTS) is the site of the first synapse of cardiovascular afferent fibers in the central nervous system. Important mechanisms for cardiovascular regulation are also present in the caudal pressor area (CPA) localized at the caudal end of the ventrolateral medulla. In the present study we sought to investigate the role of the commissural subnucleus of the NTS (commNTS) on pressor and tachycardic responses induced by L-glutamate injected into the CPA. Male Holtzman rats (n=8 rats/group) anesthetized with urethane (1.2 g/kg of body weight, iv) received injections of the GABAA receptor agonist muscimol into the commNTS. Unilateral injection of L-glutamate (10 nmol/ 100 nL) into the CPA increased mean arterial pressure (MAP, 31 4 mm Hg, vs. saline: 3 +/- 2 mm Hg) and heart rate (HR, 44 8 bpm, vs. saline: 10 7 bpm). inhibition of commNTS neurons with muscimol (120 pmol/60 nL) abolished the increase in MAP (9 4 mm Hg) and HR (17 7 bpm) produced by L-glutamate into the CPA. The present results suggest that the pressor and tachycardic responses to CPA activation are dependent on commNTS mechanisms.

Ablation of NK1 receptor bearing neurons in the nucleus of the solitary tract blunts cardiovascular reflexes in awake rats

The nucleus of the solitary tract (NTS) receives primary afferents involved in cardiovascular regulation. We investigated the role of NK1-receptor bearing neurons in the NTS on cardiovascular reflexes in awake rats fitted with chronic venous and arterial cannulae. These neurons were lesioned selectively with saporin conjugated with substance P (SP-SAP, 2 mu M, bilateral injections of 20 nL in the subpostremal NTS, or 200 nL in both the subpostremal and the commissural NTS). Before, and 7 and 14 days after injection of SP-SAP, we measured changes in blood pressure and heart rate induced by i.v. injection of phenylephrine and nitroprusside (baroreceptor reflex), cyanide (arterial chemoreceptor reflex), and phenylbiguanide (Bezold-Jarisch reflex). The smaller injections with SP-SAP completely abolished NK1 receptor staining in the subpostremal NTS. The larger injections abolished NK1 receptor immunoreactivity in an area that extended from the commissural NTS to the rostral end of the subpostremal NTS. The lesions seemed to affect only a limited number of neurons, since neutral red stained sections did not show any obvious reduction in cell number. The smaller lesions reduced the gain of baroreflex bradycardia and the hypotension induced by phenylbiguanide. The larger lesions completely abolished the response to phenylbiguanide, blocked the baroreflex bradycardia induced by phenylephrine, severely blunted the baroreflex tachycardia, and blocked the bradycardia and reduced the hypertension induced by cyanide. Thus, these responses depend critically on NK1-receptor bearing neurons in the NTS. (c) 2006 Elsevier B.V. All rights reserved.

Validation of ACB in vitro and in vivo as a biomagnetic method for measuring stomach contraction

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Role of enthalpy and entropy in moisture sorption behavior of pineapple pulp powder produced by different drying methods

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

Search for a heavy neutral gauge boson in the dielectron channel with 5.4 fb(-1) of p(p)over-bar collisions at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for heavy, top-like quark pair production in the dilepton final state in pp collisions at. root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Synthesis of KNbO3 nanostructures by a microwave assisted hydrothermal method

One-dimensional nanostructures of KNbO3 have attracted a great interest in the scientific community, mainly because of their promising application as nanoelectromechanical systems (NEMS). However, the synthesis of KNbO3 structures becomes complex due to the natural tendency to form non-stoichiometric potassium niobates. In this context, we report on the crystallization of one-dimensional KNbO3 nanostructures through the reaction between Nb2O5 and KOH under microwave-assisted hydrothermal synthesis (M-H). The use of this synthesis method made possible a very fast synthesis of singlecrystalline powders. Based on SEM, TEM and XRD characterizations, the influence of the synthesis time and the reactants concentration in the structure and morphology of the resultant KNbO3 was established. The conditions that favor the crystallization of nanofingers were determined to be small amounts of Nb2O5 and short reaction times. (C) 2008 Elsevier B.V. All rights reserved.

Effect of oxidizing atmosphere on ferroelectric and piezoelectric response of CaBi2Nb2O9 thin films

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

Expression of p53, Ki-67, and CD31 in the vaginal margins of radical hysterectomy in patients with stage IB carcinoma of the cervix

Objectives. This study was undertaken to evaluate the expression of p53, Ki-67, and CD31 both in the tumor and in the vaginal margins of radical hysterectomy in patients with stage IB squamous cell carcinoma of the cervix, as an attempt to use these proteins as possible markers for residual tumor in cervical cancer.Methods. Thirty patients with stage IB squamous cell carcinoma of the cervix were submitted to radical hysterectomy (study group), and thirty patients with uterine myoma were submitted to vaginal hysterectomy (control group) and were prospectively studied from November 2001 to September 2002. Tissue samples were taken from the tumor or cervix, anterior vaginal margin (AVM), and posterior vaginal margin (PVM) and were immunohistochemically evaluated by monoclonal antibodies for p53, Ki-67, and CD31. Vaginal samples in which the histological examination showed tumor involvement were excluded from the study.Results. Patient's mean age was 48.7 +/- 10.4 years (27-73 years). The clinical stage was IB1 in 22 patients (73.3%) and IB2 in eight patients (26.7%). The expressions of p53, Ki-67, and CD31 were significantly higher in the tumor than in the benign cervix (P < 0.001). Higher expressions of these markers were noted in the vaginal margins of radical hysterectomy in patients with cervical carcinoma compared to the vaginal margins of control patients. This association was demonstrated for p53 in the AVM proximal (P = 0.045), for Ki-67 in AVM proximal (P < 0.001), AVM distal (P < 0.001), PVM proximal (P = 0.009), and PVM distal (P < 0.001), and for CD31 in AVM proximal (P = 0.003) and AVM distal (P = 0.018). There was no difference in p53, Ki-67, and CD31 expression between the proximal and distal regions of the vaginal margins in patients with carcinoma of the cervix.Conclusion. The expressions of p53, Ki-67, and CD31 were significantly higher in both the histologically positive (cervical tumor) and negative (vaginal margins) tissues of patients who had undergone radical hysterectomy for cervical cancer compared to the benign control tissues. (C) 2004 Elsevier B.V. All rights reserved.

Interface morphology snapshots of vertically segregated thin films of semiconducting polymer/polystyrene blends

We present atomic force microscopic images of the interphase morphology of vertically segregated thin films spin coated from two-component mixtures of poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylene-vinylene] (MEH-PPV) and polystyrene (PS). We investigate the mechanism leading to the formation of wetting layers and lateral structures during spin coating using different PS molecular weights, solvents and blend compositions. Spinodal decomposition competes with the formation of surface enrichment layers. The spinodal wavelength as a function of PS molecular weight follows a power-law similar to bulk-like spinodal decomposition. Our experimental results indicate that length scales of interface topographical features can be adjusted from the nanometer to micrometer range. The importance of controlled arrangement of semiconducting polymers in thin film geometries for organic optoelectronic device applications is discussed. (c) 2007 Elsevier Ltd. All rights reserved.

Risk factors for amenorrhea in juvenile systemic lupus erythematosus (JSLE): a Brazilian multicentre cohort study

We evaluated the prevalence and clinical associations of amenorrhea in 298 female juvenile systemic lupus erythematosus (JSLE) patients (ACR criteria) followed in 12 Brazilian Paediatric Rheumatology centres. Amenorrhea was observed in 35 patients (11.7%) with a mean duration of 7.2 +/- 3.6 months. The hormones were performed in 32/35 patients and none of them had FSH and LH levels above and estradiol below the normal range according to pubertal changes. JSLE patients with amenorrhea were younger (15.04 +/- 2.5 versus 17.8 +/- 3.1 years; P = 0.001), and had a shorter period of time between menarche and current age (3.4 +/- 2.9 versus 6.7 +/- 5.4 years; P = 0.001). Interestingly, the frequency, cumulative dose, number of pulses and duration of intravenous cyclophosphamide treatment were alike in patients with and without amenorrhea (P > 0.05). In contrast, patients with amenorrhea had significantly higher SLEDAI (P = 0.01) and SLICC/ACR-DI (P = 0.024) scores compared to those without this condition. Independent risk factors identified by multivariate analysis were higher SLEDAI (OR=1.059; CI=1.004-1.116; P=0.034) and SLICC/ACR-DI (OR=2.125; IC = 1.373-3.291; P = 0.001) scores. Our data suggest that in spite of imummosuppressive therapy, JSLE patients have an adequate ovarian follicular reserve and amenorrhea is particularly associated with disease activity and damage.

Strong violet-blue light photoluminescence emission at room temperature in SrZrO3: Joint experimental and theoretical study

Ultrafine ordered and disordered SrZrO3 powders were prepared by the polymeric precursor method. The structural evolution from structural disorder to order was monitored by X-ray diffraction and X-ray absorption near-edge spectroscopy. Complex cluster vacancies [ZrO5 center dot V-O(Z)] and [SrOII center dot V-O(Z)] (where V-O(Z) = V-O(X), V-O(center dot) and V-O(center dot center dot)) were proposed for disordered powders. The intense violet-blue light photoluminescence emission measured at room temperature in the disordered powders was attributed to complex cluster vacancies. High-level quantum mechanical calculations within the density functional theory framework were used to interpret the experimental results. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

LC-DAD Determination of Fleroxacin in Bulk and Pharmaceutical Dosage Forms

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)