819 resultados para Nature study


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

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This study aimed to investigate the phenomenology of obsessive compulsive disorder (OCD), addressing specific questions about the nature of obsessions and compulsions, and to contribute to the World Health Organization's (WHO) revision of OCD diagnostic guidelines. Data from 1001 patients from the Brazilian Research Consortium on Obsessive Compulsive Spectrum Disorders were used. Patients were evaluated by trained clinicians using validated instruments, including the Dimensional Yale Brown Obsessive Compulsive Scale, the University of Sao Paulo Sensory Phenomena Scale, and the Brown Assessment of Beliefs Scale. The aims were to compare the types of sensory phenomena (SP, subjective experiences that precede or accompany compulsions) in OCD patients with and without tic disorders and to determine the frequency of mental compulsions, the co-occurrence of obsessions and compulsions, and the range of insight. SP were common in the whole sample, but patients with tic disorders were more likely to have physical sensations and urges only. Mental compulsions occurred in the majority of OCD patients. It was extremely rare for OCD patients to have obsessions without compulsions. A wide range of insight into OCD beliefs was observed, with a small subset presenting no insight. The data generated from this large sample will help practicing clinicians appreciate the full range of OCD symptoms and confirm prior studies in smaller samples the degree to which insight varies. These findings also support specific revisions to the WHO's diagnostic guidelines for OCD, such as describing sensory phenomena, mental compulsions and level of insight, so that the world-wide recognition of this disabling disorder is increased. (C) 2014 Elsevier Ltd. All rights reserved.

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(Photo)electrochemical experiments on pyrite electrodes in acetic acid-acetate buffer (pH = 4.5) are conducted to clarify the main oxidation reactions and the nature of the products. Electrochemical reactions in the -0.40 to 1.25 V (SHE) potential range are studied, and the production of iron (III) polysulfide from anodically formed iron oxides and polysulfides is discussed. Charges experimentally obtained are considered for the estimation of the most likely stoichiometry of the metallic polysulfide. The photoselectivity of the pyrite corrosion process indicates that the oxidation reactions of Fe2+ and S-2(2-) an not consecutive. The changes in stoichiometry and/or annihilation of crystalline structure defects are responsible for the observed photosensitivity of pyrite. A description of light effects on the interfacial behaviour and stability of pyrite is presented in terms of conduction and valence band energies, and thermodynamic potentials. (C) 2001 Elsevier Science B.V. All rights reserved.

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Background and ObjectivesHypokalemia has been consistently associated with high mortality rate in peritoneal dialysis. However, studies investigating if hypokalemia is acting as a surrogate marker of comorbidities or has a direct effect in the risk for mortality have not been studied. Thus, the aim of this study was to analyze the effect of hypokalemia on overall and cause-specific mortality.Design, Setting, Participants and MeasurementsThis is an analysis of BRAZPD II, a nationwide prospective cohort study. All patients on PD for longer than 90 days with measured serum potassium levels were used to verify the association of hypokalemia with overall and cause-specific mortality using a propensity match score to reduce selection bias. In addition, competing risks were also taken into account for the analysis of cause-specific mortality.ResultsThere was a U-shaped relationship between time-averaged serum potassium and all-cause mortality of PD patients. Cardiovascular disease was the main cause of death in the normokalemic group with 133 events (41.8%) followed by PD-non related infections, n=105 (33.0%). Hypokalemia was associated with a 49% increased risk for CV mortality after adjustments for covariates and the presence of competing risks (SHR 1.49; CI95% 1.01-2.21). In contrast, in the group of patients with K < 3.5mEq/L, PD-non related infections were the main cause of death with 43 events (44.3%) followed by cardiovascular disease (n=36; 37.1%). For PD-non related infections the SHR was 2.19 (CI95% 1.52-3.14) while for peritonitis was SHR 1.09 (CI95% 0.47-2.49).ConclusionsHypokalemia had a significant impact on overall, cardiovascular and infectious mortality even after adjustments for competing risks. The causative nature of this association suggested by our study raises the need for intervention studies looking at the effect of potassium supplementation on clinical outcomes of PD patients.

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

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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Biocompatible inorganic nano- and microcarriers can be suitable candidates for protein delivery. This study demonstrates facile methods of functionalization by using nanoscale linker molecules to change the protein adsorption capacity of hydroxyapatite (HA) powder. The adsorption capacity of bovine serum albumin as a model protein has been studied with respect to the surface modifications. The selected linker molecules (lysine, arginine, and phosphoserine) can influence the adsorption capacity by changing the electrostatic nature of the HA surface. Qualitative and quantitative analyses of linker-molecule interactions with the HA surface have been performed by using NMR spectroscopy, zeta-potential measurements, X-ray photoelectron spectroscopy, and thermogravimetric analyses. Additionally, correlations to theoretical isotherm models have been calculated with respect to Langmuir and Freundlich isotherms. Lysine and arginine increased the protein adsorption, whereas phosphoserine reduced the protein adsorption. The results show that the adsorption capacity can be controlled with different functionalization, depending on the protein-carrier selections under consideration. The scientific knowledge acquired from this study can be applied in various biotechnological applications that involve biomolecule-inorganic material interfaces.

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Starch is one of the most important sources of reserve of carbohydrate in plants and the main source in the human diet due to its abundance in the nature. There no other food ingredient that can be compared with starch in terms of sheer versatility of application in the food industry. Unprocessed native starches are structurally too weak and functionally too restricted for application in today’s advanced food and industrial technologies. The main objective of this study was to compare the thermal behavior of native cassava starch and those treated with hydrogen peroxide, as well as those treated with hydrogen peroxide and ferrous sulfate. The cassava starch was extracted from cassava roots (Manihot esculenta, Crantz) and treated by standardized hydrogen peroxide (H2 O2 ) solutions at 1, 2 and 3% (with or without FeSO4 ). Investigated by using they are thermoanalytical techniques: thermogravimetry - TG, differential thermal analysis – DTA and differential scanning calorimetry - DSC, as well as optical microscopy and X-ray powder diffractometry. The results showed the steps of thermal decomposition, changes in temperatures and in gelatinization enthalpy and small changes in crystallinity of the granules.

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Corrosion research in steels is one of the areas in which Mossbauer spectroscopy has become a required analytical technique, since it is a powerful tool for both identifying and quantifying distinctive phases (which contain Fe) with accuracy. In this manuscript, this technique was used to the study of corrosion resistance of plasma nitrided AISI 316L samples in the presence of chloride anions. Plasma nitriding has been carried out using dc glow-discharge, nitriding treatments, in medium of 80 vol.% H-2 and 20 vol.% N-2, at 673 K, and at different time intervals: 2, 4, and 7 h. Treated samples were characterized by means of phase composition and morphological analysis, and electrochemical tests in NaCl aerated solution in order to investigate the influence of treatment time on the microstructure and the corrosion resistance, proved by conversion electron Mossbauer spectroscopy (CEMS), glancing angle X-ray diffraction (GAXRD), scanning electron microscopy (SEM) and potentiodynamic polarization. A modified layer of about 8 gin was observed for all the nitrided samples, independently of the nitriding time. A metastable phase, S phase or gamma(N), was produced. It seems to be correlated with gamma`-Fe-4 N phase. If the gamma(N) fraction decreases, the gamma` fraction increases. The gamma(N) magnetic nature was analyzed. When the nitriding time increases, the results indicate that there is a significant reduction in the relative fraction of the magnetic gamma(N) (in) phase. In contrast, the paramagnetic gamma(N) (p) phase increases. The GAXRD analysis confirms the Mossbauer results, and it also indicates CrN traces for the sample nitrided for 7 h. Corrosion results demonstrate that time in the plasma nitriding treatment plays an important role for the corrosion resistance. The sample treated for 4 h showed the best result of corrosion resistance. It seems that the epsilon/gamma` fraction ratio plays an important role in thin corrosion resistance since this sample shows the maximum value for this ratio. (c) 2008 Published by Elsevier B.V.

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Background: Functional neuroimaging studies have shown that specific brain areas are associated with alcohol craving including the dorsolateral prefrontal cortex (DLPFC). We tested whether modulation of DLPFC using transcranial direct current stimulation (tDCS) could alter alcohol craving in patients with alcohol dependence while being exposed to alcohol cues. Methods: We performed a randomized sham-controlled study in which 13 subjects received sham and active bilateral tDCS delivered to DLPFC (anodal left/cathodal right and anodal right/cathodal left). For sham stimulation, the electrodes were placed at the same positions as in active stimulation; however, the stimulator was turned off after 30 s of stimulation. Subjects were presented videos depicting alcohol consumption to increase alcohol craving. Results: Our results showed that both anodal left/cathodal right and anodal right/cathodal left significantly decreased alcohol craving compared to sham stimulation (p < 0.0001). In addition, we found that following treatment, craving could not be further increased by alcohol cues. Conclusions: Our findings showed that tDCS treatment to DLPFC can reduce alcohol craving. These findings extend the results of previous studies using noninvasive brain stimulation to reduce craving in humans. Given the relatively rapid suppressive effect of tDCS and the highly fluctuating nature of alcohol craving, this technique may prove to be a valuable treatment strategy within the clinical setting. (C) 2007 Elsevier Ireland Ltd. All rights reserved.

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This long-term extension of an 8-week randomized, naturalistic study in patients with panic disorder with or without agoraphobia compared the efficacy and safety of clonazepam (n = 47) and paroxetine (n = 37) over a 3-year total treatment duration. Target doses for all patients were 2 mg/d clonazepam and 40 mg/d paroxetine (both taken at bedtime). This study reports data from the long-term period (34 months), following the initial 8-week treatment phase. Thus, total treatment duration was 36 months. Patients with a good primary outcome during acute treatment continued monotherapy with clonazepam or paroxetine, but patients with partial primary treatment success were switched to the combination therapy. At initiation of the long-term study, the mean doses of clonazepam and paroxetine were 1.9 (SD, 0.30) and 38.4 (SD, 3.74) mg/d, respectively. These doses were maintained until month 36 (clonazepam 1.9 [ SD, 0.29] mg/d and paroxetine 38.2 [SD, 3.87] mg/d). Long-term treatment with clonazepam led to a small but significantly better Clinical Global Impression (CGI)-Improvement rating than treatment with paroxetine (mean difference: CGI-Severity scale -3.48 vs -3.24, respectively, P = 0.02; CGI-Improvement scale 1.06 vs 1.11, respectively, P = 0.04). Both treatments similarly reduced the number of panic attacks and severity of anxiety. Patients treated with clonazepam had significantly fewer adverse events than those treated with paroxetine (28.9% vs 70.6%, P < 0.001). The efficacy of clonazepam and paroxetine for the treatment of panic disorder was maintained over the long-term course. There was a significant advantage with clonazepam over paroxetine with respect to the frequency and nature of adverse events.

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The fading of persistent luminescence in Sr2MgSi2O7:Eu2+,R3+ (R: Y, La-Nd, Sm-Lu) was studied combining thermoluminescence (TL) and room temperature (persistent) luminescence measurements to gain more information on the mechanism of persistent luminescence. The TL glow curves showed the main trap signal at ca. 80 degrees C, corresponding to 0.6 eV as the trap depth, with every R co-dopant. The TL measurements carried out with different irradiation times revealed the general order nature of the TL bands. The results obtained from the deconvolutions of the glow curves allowed the prediction of the fading of persistent luminescence with good accuracy, though only when using the Becquerel decay law. (C) 2012 Optical Society of America

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Communication Studies currently undergoes a crisis of paradigms that requires an ontological review that must begin with a debate about the conditions of possibility of every communicational phenomena. In this article we argue that semiosis offers a conceptual framework that allows for the study of communication as qualitative action. Semiosis, or the action of the sign, is here defined as a fundamental process based on perception that models the world of species, creating cognition and culture. At the core of semiosis are dynamic structures that the authors have defined as 'ontological diagrams'. The first purpose of Semiotics of Communication is to understand how these modeling systems evolve ontologically and phylogenically, producing, in the case of human culture, means of communication ever more varied and technologically advanced.

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Diffuse large B-cell lymphoma can be subclassified into at least two molecular subgroups by gene expression profiling: germinal center B-cell like and activated B-cell like diffuse large B-cell lymphoma. Several immunohistological algorithms have been proposed as surrogates to gene expression profiling at the level of protein expression, but their reliability has been an issue of controversy. Furthermore, the proportion of misclassified cases of germinal center B-cell subgroup by immunohistochemistry, in all reported algorithms, is higher compared with germinal center B-cell cases defined by gene expression profiling. We analyzed 424 cases of nodal diffuse large B-cell lymphoma with the panel of markers included in the three previously described algorithms: Hans, Choi, and Tally. To test whether the sensitivity of detecting germinal center B-cell cases could be improved, the germinal center B-cell marker HGAL/GCET2 was also added to all three algorithms. Our results show that the inclusion of HGAL/GCET2 significantly increased the detection of germinal center B-cell cases in all three algorithms (P<0.001). The proportions of germinal center B-cell cases in the original algorithms were 27%, 34%, and 19% for Hans, Choi, and Tally, respectively. In the modified algorithms, with the inclusion of HGAL/GCET2, the frequencies of germinal center B-cell cases were increased to 38%, 48%, and 35%, respectively. Therefore, HGAL/GCET2 protein expression may function as a marker for germinal center B-cell type diffuse large B-cell lymphoma. Consideration should be given to the inclusion of HGAL/GCET2 analysis in algorithms to better predict the cell of origin. These findings bear further validation, from comparison to gene expression profiles and from clinical/therapeutic data. Modern Pathology (2012) 25, 1439-1445; doi: 10.1038/modpathol.2012.119; published online 29 June 2012