38 resultados para bandwidth 3.1 GHz to 10.6 GHz

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo (BDPI/USP)


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The aim of this study was to determine whether the presence of leprosy reactional episodes could be associated with chronic oral infection. Thirty-eight leprosy patients were selected and divided into 2 groups: group I - 19 leprosy patients with oral infections, and group II - 19 leprosy patients without oral infections. Ten patients without leprosy, but presenting oral infections, were assigned to the control group. Leprosy patients were classified according to Ridley and Jopling classification and reactional episodes of the erythema nodosum type or reversal reaction were identified by clinical and histopathological features associated with serum IL-1, TNF-α, IL-6, IFN-γ and IL-10 levels. These analyses were performed immediately before and 7 days after the oral infection elimination. Patients from group I presenting oral infections reported clinical improvement of the symptoms of reactional episodes after dental treatment. Serum IL-1, TNF-α, IL-6, IFN-γ and IL-10 levels did not differ significantly before and after dental treatment as determined by the Wilcoxon test (p>0.05). Comparison of the 2 groups showed statistically significant differences in IL-1 and IL-6 at baseline and in IL-1, IL-6 and IL-10 on the occasion of both collections 7 days after therapy. Serum IL-6 and IL-10 levels in group I differed significantly at baseline compared to control (Mann-Whitney test; p<0.05). These results suggest that oral infection could be involved as a maintenance factor in the pathogenesis of leprosy reactional episodes.

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Singlet molecular oxygen O(2)((1)Delta(g)) is a potent oxidant that can react with different biomolecules, including DNA, lipids and proteins. Many polycyclic aromatic hydrocarbons have been studied as O(2)((1)Delta(g)) chemical traps. Nevertheless, a suitable modification in the polycyclic aromatic ring must be made to increase the yield of O(2)((1)Delta(g)) chemical trapping. With this goal, an anthracene derivative, diethyl-3,3 '-(9,10-anthracenediyl)bisacrylate (DADB), was obtained from the reaction of 9,10-dibromoanthracene and ethyl acrylate through the Heck coupling reaction. The coupling of ethyl acrylate with the anthracene ring produced a new lipophilic, esterified, fluorescent probe reactive toward O(2)((1)Delta(g)). This compound reacts with O(2)((1)Delta(g)) at a rate of k(r) = 1.69 x 10(6) M(-1) s(-1) forming a stable endoperoxide (DADBO(2)), which was characterized by UV-Vis, fluorescence, HPLC/MS and (1)H and (13)C NMR techniques. The photophysical, photochemical and thermostability features of DADB were also evaluated. Furthermore, this compound has the potential for great application in biological systems because it is easily synthetized in large amount and generates specific endoperoxide (DADBO(2)), which can be easily detected by HPLC tandem mass spectrometry (HPLC/MS/MS).

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beta-1,3-1,4-Glucanases (E.C. 3.2.1.73) hydrolyze linked beta-D-glucans, such as lichenan and barley beta-glucan. Recombinant beta-1,3-1,4-glucanase from Bacillus subtilis expressed in Escherichia coil and purified by Ni-NTA chromatography exhibited optimum activity at 50 degrees C and pH 6.0. The catalytic half-life at 60 degrees C decreased from 90 to 5 min when the enzyme was incubated in the presence and absence of Ca(2+) respectively. The kinetic parameters of lichenan hydrolysis were 2695, 3.1 and 1220 for V(max) (mu mol/min/mg), K(m) (mg mL(-1)) and K(cat) (s(-1)), respectively. Analysis by DLS, AUC and SAXS demonstrated the enzyme is monomeric in solution. Chemical denaturation monitored by ITFE and far-UV CD yielded Delta G(H2O) values of 9.6 and 9.1 kcal/mol, respectively, showing that the enzyme has intermediate stability when compared with other Bacillus beta-1,3-1,4-glucanases. The crystal structure shows the anti-parallel jelly-roll beta-sheet conserved in all GH16 beta-1,3-1,4-glucanases, with the amino acid differences between Bacillus sp. enzymes that are likely determinants of stability being distributed throughout the protein. (C) 2011 Elsevier Ltd. All rights reserved.

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Although CO(2) laser irradiation can decrease enamel demineralisation, it has still not been clarified which laser wavelength and which irradiation conditions represent the optimum parameters for application as preventive treatment. The aim of the present explorative study was to find low-fluence CO(2) laser (lambda = 10.6 mu m) parameters resulting in a maximum caries-preventive effect with the least thermal damage. Different laser parameters were systematically evaluated in 3 steps. In the first experiment, 5 fluences of 0.1, 0.3, 0.4, 0.5 and 0.6 J/cm(2), combined with high repetition rates and 10 mu s pulse duration, were chosen for the experiments. In a second experiment, the influence of different pulse durations (5, 10, 20, 30 and 50 mu s) on the demineralisation of dental enamel was assessed. Finally, 3 different irradiation times (2, 5 and 9 s) were tested in a third experiment. In total, 276 bovine enamel blocks were used for the experiments. An 8-day pH-cycling regime was performed after the laser treatment. Demineralisation was assessed by lesion depth measurements with a polarised light microscope, and morphological changes were assessed with a scanning electron microscope. Irradiation with 0.3 J/cm(2), 5 mu s, 226 Hz for 9 s (2,036 overlapping pulses) increased caries resistance by up to 81% compared to the control and was even significantly better than fluoride application (25%, p < 0.0001). Scanning electron microscopy examination did not reveal any obvious damage caused by the laser irradiation. Copyright (C) 2009 S. Karger AG, Basel

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It is generally assumed that the magnetic fields of millisecond pulsars (MSPs) are similar to 10(8) G. We argue that this may not be true and the fields may be appreciably greater. We present six evidences for this: (1) The similar to 10(8)G field estimate is based on magnetic dipole emission losses which is shown to be questionable; (2) The MSPs in low mass X-ray binaries (LMXBs) are claimed to have < 10(11) G on the basis of a Rayleygh-Taylor instability accretion argument. We show that the accretion argument is questionable and the upper limit 10(11) G may be much higher; (3) Low magnetic field neutron stars have difficulty being produced in LMXBs; (4) MSPs may still be accreting indicating a much higher magnetic field; (5) The data that predict similar to 10(8) G for MSPs also predict ages on the order of, and greater than, ten billion years, which is much greater than normal pulsars. If the predicted ages are wrong, most likely the predicted similar to 10(8) G fields of MSPs are wrong; (6) When magnetic fields are measured directly with cyclotron lines in X-ray binaries, fields a parts per thousand << 10(8) G are indicated. Other scenarios should be investigated. One such scenario is the following. Over 85% of MSPs are confirmed members of a binary. It is possible that all MSPs are in large separation binaries having magnetic fields > 10(8) G with their magnetic dipole emission being balanced by low level accretion from their companions.

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There is recent evidence that galectin-3 participates in immunity to infections, mostly by tuning cytokine production. We studied the balance of Th1/Th2 responses to P. brasiliensis experimental infection in the absence of galectin-3. The intermediate resistance to the fungal infection presented by C57BL/6 mice, associated with the development of a mixed type of immunity, was replaced with susceptibility to infection and a Th2-polarized immune response, in galectin-3-deficient (gal3(-/-)) mice. Such a response was associated with defective inflammatory and delayed type hypersensitivity (DTH) reactions, high IL-4 and GATA-3 expression and low nitric oxide production in the organs of infected animals. Gal3(-/-) macrophages exhibited higher TLR2 transcript levels and IL-10 production compared to wild-type macrophages after stimulation with P. brasiliensis antigens. We hypothesize that, during an in vivo P. brasiliensis infection, galectin-3 exerts its tuning role on immunity by interfering with the generation of regulatory macrophages, thus hindering the consequent Th2-polarized type of response.

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Background: Several plasma membrane transporters have been shown to mediate the cellular influx and/or efflux of iodothyronines, including the sodium-independent organic anion co-transporting polypeptide 1 (OATP1), the sodium taurocholate co-transporting polypeptide (NTCP), the L-type amino acid transporter 1 (LAT1) and 2 (LAT2), and the monocarboxylate transporter 8 (MCT8). The aim of this study was to investigate if the mRNAs of these transporters were expressed and regulated by thyroid hormone (TH) in mouse calvaria-derived osteoblastic MC3T3-E1 cells and in the fetal and postnatal bones of mice. Methods: The mRNA expression of the iodothyronine transporters was investigated with real-time polymerase chain reaction analysis in euthyroid and hypothyroid fetuses and litters of mice and in MC3T3-E1 cells treated with increasing doses of triiodothyronine (T(3); 10(-10) to 10(-6) M) or with 10(-8) M T(3) for 1-9 days. Results: MCT8, LAT1, and LAT2 mRNAs were detected in fetal and postnatal femurs and in MC3T3-E1 cells, while OATP1 and NTCP mRNAs were not. LAT1 and LAT2 mRNAs were not affected by TH status in vivo or in vitro or by the stage of bone development or osteoblast maturation (analyzed by the expression of osteocalcin and alkaline phosphatase, which are key markers of osteoblastic differentiation). In contrast, the femoral mRNA expression of MCT8 decreased significantly during post-natal development, whereas MCT8 mRNA expression increased as MC3T3-E1 cells differentiated. We also showed that MCT8 mRNA was up-regulated in the femur of hypothyroid animals, and that it was down-regulated by treatment with T(3) in MC3T3-E1 cells. Conclusions: This is the first study to demonstrate the mRNA expression of LAT1, LAT2, and MCT8 in the bone tissue of mice and in osteoblast-like cells. In addition, the pattern of MCT8 expression observed in vivo and in vitro suggests that MCT8 may be important to modulate TH effects on osteoblast differentiation and on bone development and metabolism.

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The transition of plasmons from propagating to localized state was studied in disordered systems formed in GaAs/AlGaAs superlattices by impurities and by artificial random potential. Both the localization length and the linewidth of plasmons were measured by Raman scattering. The vanishing dependence of the plasmon linewidth on the disorder strength was shown to be a manifestation of the strong plasmon localization. The theoretical approach based on representation of the plasmon wave function in a Gaussian form well accounted for by the obtained experimental data.

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In the title compound, C(16)H(12)N(2)O(2)S, the carbonylthiourea group forms dihedral angles of 75.4 (1) and 13.1 (2)degrees, respectively, with the naphthalene ring system and furan ring. The molecule adopts a trans-cis configuration with respect to the positions of the furoyl and naphthyl groups relative to the S atom across the thiourea C-N bonds. This geometry is stabilized by an N-H center dot center dot center dot center dot O intramolecular hydrogen bond. In the crystal structure, molecules are linked by N-H center dot center dot center dot S hydrogen bonds, forming centrosymmetric dimers which are interlinked through C-H center dot center dot center dot pi interactions.

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A unidirectional fiber composite is considered here, the fibers of which are empty cylindrical holes periodically distributed in a transversely isotropic piezoelectric matrix, The empty-fiber cross-section is circular and the periodicity is the same in two directions at an angle pi/2 or pi/3. Closed-form formulae for all electromechanical effective properties of these 3-1 longitudinally periodic porous piezoelectric materials are presented. The derivation of such expressions is based on the asymptotic homogenization method as a limit of the effective properties of two-phase transversely isotropic parallel fiber-reinforced composites when the fibers properties tend to zero. The plane effective coefficients satisfy the corresponding Schulgasser-Benveniste-Dvorak universal type of relations, A new relation among the antiplane effective constants from the solutions of two antiplane strains and potential local problems is found. This relation is valid for arbitrary shapes of the empty-fiber cross-sections. Based on such a relation, and using recent numerical results for isotropic conductive composites, the antiplane effective properties are computed for different geometrical shapes of the empty-fiber cross-section. Comparisons with other analytical and numerical theories are presented. (c) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

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Chagas disease (American trypanosomiasis) is one of the most important parasitic diseases with serious social and economic impacts mainly on Latin America. This work reports the synthesis, in vitro trypanocidal evaluation, cytotoxicity assays, and molecular modeling and SAR/QSAR studies of a new series of N-phenylpyrazole benzylidene-carbohydrazides. The results pointed 6k (X = H, Y = p-NO(2), pIC(50) = 4.55 M) and 6l (X = F, Y = p-CN, pIC(50) = 4.27 M) as the most potent derivatives compared to crystal violet (pIC(50) = 3.77 M). The halogen-benzylidene-carbohydrazide presented the lowest potency whereas 6l showed the most promising pro. le with low toxicity (0% of cell death). The best equation from the 4D-QSAR analysis (Model 1) was able to explain 85% of the activity variability. The QSAR graphical representation revealed that bulky X-substituents decreased the potency whereas hydrophobic and hydrogen bond acceptor Y-substituents increased it. (C) 2008 Elsevier Ltd. All rights reserved.

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Introduction. Priapism is one of several symptoms observed in accidental bites by the spider Phoneutria nigriventer. The venom of this spider is comprised of many toxins, and the majority has been shown to affect excitable ion channels, mainly sodium (Na+) channels. It has been demonstrated that PnTx2-6, a peptide extracted from the venom of P. nigriventer, causes erection in anesthetized rats and mice. Aim. We investigated the mechanism by which PnTx2-6 evokes relaxation in rat corpus cavernosum. Main Outcome Measures. PnTx2-6 toxin potentiates nitric oxide (NO)-dependent cavernosal relaxation. Methods. Rat cavernosal strips were incubated with bretylium (3 x 10-5 M) and contracted with phenylephrine (PE; 10-5 M). Relaxation responses were evoked by electrical field stimulation (EFS) or sodium nitroprusside (SNP) before and after 4 minutes of incubation with PnTx2-6 (10-8 M). The effect of PnTx2-6 on relaxation induced by EFS was also tested in the presence of atropine (10-6 M), a muscarinic receptor antagonist, N-type Ca2+ channel blockers (omega-conotoxin GVIA, 10-6 M) and sildenafil (3 x 10-8 M). Technetium99m radiolabeled PnTx2-6 subcutaneous injection was administrated in the penis. Results. Whereas relaxation induced by SNP was not affected by PnTx2-6, EFS-induced relaxation was significantly potentiated by this toxin as well as PnTx2-6 plus SNP. This potentiating effect was further increased by sildenafil, not altered by atropine, however was completely blocked by the N-type Ca2+ channels. High concentrated levels of radiolabeled PnTx2-6 was specifically found in the cavernosum tissue, suggesting PnTx2-6 is an important toxin responsible for P. nigriventer spider accident-induced priapism. Conclusion. We show that PnTx2-6 slows Na+ channels inactivation in nitrergic neurons, allowing Ca2+ influx to facilitate NO/cGMP signalling, which promotes increased NO production. In addition, this relaxation effect is independent of phosphodiesterase enzyme type 5 inhibition. Our data displays PnTx2-6 as possible pharmacological tool to study alternative treatments for erectile dysfunction. Nunes KP, Cordeiro MN, Richardson M, Borges MN, Diniz SOF, Cardoso VN, Tostes R, De Lima ME, Webb RC, and Leite R. Nitric oxide-induced vasorelaxation in response to PnTx2-6 toxin from Phoneutria nigriventer spider in rat cavernosal tissue. J Sex Med 2010;7:3879-3888.

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Objective(s): We intend to verify if fetal volume and crown-rump length were different between singletons and twins in pregnancies aged from 7 to 10 weeks and to evaluate if fetal volume is more accurate to determine the gestational age than crown-rump length at this gestational age. Study design: From 52 days (7 weeks and 3 days) to 73 days (10 weeks and 3 days) weekly three-dimensional Ultrasonography was per-formed in 20 twin fetuses and 20 singletons. Crown-rump length and fetal volume using VOCAL were assessed in all examinations. The `true` gestational age was based on oocyte retrieval. Results: At the age of 52 days, the crown-rump length was 11.74 +/- 0.27 mm (mean +/- S.D.) and 11.48 +/- 0.22 mm (singletons and twins, respectively), while the fetal volume was 0.354 +/- 0.015 cm(3) and 0.324 +/- 0.012 cm(3). At the gestational age of 73 days, the crown-rump length was 36.19 +/- 0.90 mm and 35.87 +/- 0.54 mm and the fetal volume was 6.204 +/- 0.090 cm(3) and 6.083 +/- 0.081 cm(3). The total relative increase observed was much higher for fetal volume than for CRL: 1705 +/- 301% vs. 210 +/- 33% in singletons and 1827 +/- 305% vs. 214 +/- 25% in twins. The 95% limits of agreement (+/- 2.3 days vs. +/- 3.2 days, fetal volume vs. crown-rump length) and the intraclass correlation coefficients (0.989 vs. 0.978) between the ""true"" gestational age and that predicted by fetal volume were better than those predicted by crown-rump length. No significant difference was identified between singletons and twins for both fetal volume and crown-rump length. Conclusion(s): Twins and singletons had similar fetal volume and crown-rump length between the 7th and 10th week of gestational age. Additionally, fetal volume assessed by VOCAL was better than crown-rump length to estimate the gestational age at the evaluated period. However, the improvement was small and probably without clinical significance. Condensation: Fetal volume and crown-rump length were similar between singletons and twins. Fetal volume relative increase was higher and the predicted gestational age was better. (c) 2009 Elsevier Ireland Ltd. All rights reserved.

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Objective: The purpose of the study was to investigate whether dentine irradiation with a pulsed CO(2) laser (10.6 mu m) emitting pulses of 10 ms is capable of reducing dentine calcium and phosphorus losses in an artificial caries model. Design: The 90 dentine slabs obtained from bovine teeth were randomly divided into six groups (n = 15): negative control group (GC); positive control group, treated with fluoride 1.23% (GF); and laser groups irradiated with 8 J/cm(2) (L8); irradiated as in L8 + fluoride 1.23% (L8F); irradiated with 11j/cm(2) (L11); irradiated as in L11 + fluoride 1.23% (L11F). After laser irradiation the samples were submitted to a pH-cycling model for 9 days. The calcium and phosphorous contents in the de- and remineralization solutions were measured by means of inductively coupled plasma optical emission spectrometer - ICP-OES. Additionally intra-pulpal temperature measurements were performed. The obtained data were analysed by means of ANOVA and Tukey`s test (alpha = 0.05). Results: In the demineralization solutions the groups L11F and GF presented significantly lower means of calcium and phosphorous losses than the control group; and in L11F means were significantly lower than in the fluoride group. Both irradiation parameters tested caused intrapulpal temperature increase below 2 degrees C. Conclusion: It can be concluded that under the conditions of this study, CO(2) laser irradiation (10.6 mu m) with 11J/cm(2) (540 mJ and 10 Hz) of fluoride treated dentine surfaces decreases the loss of calcium and phosphorous in the demineralization process and does not cause excessive temperature increase inside the pulp chamber. (C) 2010 Elsevier Ltd. All rights reserved.

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Although the cariostatic effects of CO(2) laser on enamel have been shown, its effects on root surface demineralization remains uncertain. The objectives of this in vitro research was to establish safe parameters for a pulsed 10.6 mu m CO(2) laser and to evaluate its effect on morphological features of the root surface, as well as on the reduction of root demineralization. Ninety-five human root surfaces were randomly divided into five groups: G1-No treatment (control); G2-2.5 J/cm(2); G3-4.0 J/cm(2); G4-5.0 J/cm(2); and G5-6.0 J/cm(2). Intrapulpal temperature was evaluated during root surface irradiation by a thermocouple and morphological changes were evaluated by SEM. After the surface treatment, the specimens were submitted to a 7-day pH-cycling model. Subsequently, the cross-sectional Knoop microhardness values were measured. For all irradiated groups, intrapulpal temperature changes were less than 1.5 degrees C. Scanning electron microscopy images indicated that fluences as low as 4.0 J/cm(2) were sufficient to induce morphological changes in the root surface. Additionally, for fluences reaching or exceeding 4.0 J/cm(2), laser-induced inhibitory effects on root surface demineralization were observed. It was concluded that laser energy density in the range of 4.0 to 6.0 J/cm(2) could be applied to a dental root to reduce demineralization of this surface without compromising pulp vitality.