675 resultados para Cutoff wavenumbers


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PbO-BiO 1.5-GaO 1.5-based glasses are good candidates for optical applications, because of some of their interesting characteristics, such as high refraction indices and high transmission in the ultraviolet (UV), visible (VIS), and infrared (IR) regions. A limited stage in the processing of these glasses is the corrosion that is caused by the melt in all currently used conventional crucibles, such as noble metals (platinum or gold) and Al 2O 3. The absorption of crucible material by the glass composition may reduce the transmission level, the cutoff in the UV-VIS, and IR regions, and the thermal stability. In this study, a SnO 2 crucible has been tested for PbO-BiO 1.5-GaO 1.5 molten glass. Optical and thermal analyses show, in some cases, advantages over the use of platinum and Al 2O 3 crucibles. A visible cutoff value of 474 nm has been measured, and a longer melting time (850°C for 4 h) results in a significant reduction of the O-H absorption band at 3.2 μm.

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

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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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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OBJECTIVE: To evaluate the ability of orbital apex crowding volume measurements calculated with multidetector-computed tomography to detect dysthyroid optic neuropathy. METHODS: Ninety-three patients with Graves' orbitopathy were studied prospectively. All of the patients underwent a complete neuro-ophthalmic examination and computed tomography scanning. Volumetric measurements were calculated from axial and coronal contiguous sections using a dedicated workstation. Orbital fat and muscle volume were estimated on the basis of their attenuation values (in Hounsfield units) using measurements from the anterior orbital rim to the optic foramen. Two indexes of orbital muscle crowding were calculated: i) the volumetric crowding index, which is the ratio between soft tissue (mainly extraocular muscles) and orbital fat volume and is based on axial scans of the entire orbit; and ii) the volumetric orbital apex crowding index, which is the ratio between the extraocular muscles and orbital fat volume and is based on coronal scans of the orbital apex. Two groups of orbits (with and without dysthyroid optic neuropathy) were compared. RESULTS: One hundred and two orbits of 61 patients with Graves' orbitopathy met the inclusion criteria and were analyzed. Forty-one orbits were diagnosed with Graves' orbitopathy, and 61 orbits did not have optic neuropathy. The two groups of orbits differed significantly with regard to both of the volumetric indexes (p<0.001). Although both indexes had good discrimination ability, the volumetric orbital apex crowding index yielded the best results with 92% sensitivity, 86% specificity, 81%/94% positive/negative predictive value and 88% accuracy at a cutoff of 4.14. CONCLUSION: This study found that the orbital volumetric crowding index was a more effective predictor of dysthyroid optic neuropathy than previously described computed tomography indexes were.

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Background: Prevalence of individuals with a high cardiovascular risk is elevated in elderly populations. Although metabolic syndrome (MS) increases cardiovascular risk, information is scarce on the prevalence of MS in the elderly. In this study we assessed MS prevalence in a population of elderly Japanese-Brazilians using different MS definitions according to waist circumference cutoff values. Material/Methods: We studied 339 elderly subjects, 44.8% males, aged between 60 to 88 years (70.1 +/- 6.8). MS was defined according to criteria proposed by the Joint Interim Statement in 2009. As waist circumference cutoff point values remain controversial for Asian and Japanese populations, we employed 3 different cutoffs that are commonly used in Japanese epidemiological studies: 1) >90 cm for men and >80 cm for women; 2) >85 cm for men and >90 cm for women; 3) >85 cm for men and >80 cm for women. Results: MS prevalence ranged from 59.9% to 65.8% according to the different definitions. We observed 90% concordance and no statistical difference (p>0.05) in MS prevalence between the 3 definitions. MS diagnosis according to all 3 cutoff values was found in 55.8% of our population, while in only 34.2% was MS discarded by all cutoffs. The prevalence of altered MS components was as follows: arterial blood pressure 82%, fasting glycemia 65.8%, triglyceride 43.4%, and HDL-C levels 36.9%. Conclusions: Elderly Japanese-Brazilians present high metabolic syndrome prevalence independent of waist circumference cutoff values. Concordance between the 3 definitions is high, suggesting that all 3 cutoff values yield similar metabolic syndrome prevalence values in this population.

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CONTEXT AND OBJECTIVE: Brazil is undergoing a period of epidemiological transition associated with demographic and nutritional changes. The prevalence of obesity is also increasing in children and is causing numerous health problems that are becoming public health issues. The aim here was to evaluate the prevalence of overweight among children of two and three years of age. DESIGN AND SETTING: Cross-sectional study in municipal day care centers in Taubate, state of Sao Paulo, Brazil. METHODS: Weight and height measurements were made on 447 preschool children forming a probabilistic randomized sample. Their body mass index (BMI) was calculated. Their nutritional status was classified using the World Health Organization reference cutoff points (2006). Their mean weight, height and BMI were compared according to their age and sex. RESULTS: The mean values for the final sample (n = 447) were as follows: mean age: 38.6 months (+/- 3.5) and Z scores for: weight/height (W/H): 0.50 (+/- 1.22); height/age: -0.03 (+/- 1.07); weight/age (W/A): 0.51 (+/- 1.23); and BMI: 0.51(+/- 1.23). The prevalence of overweight children (BMI > 1 z) was 28.86%, while the prevalence of underweight children (BMI < -2 z) was 0.89%. There were no differences in mean BMI among the two and three-year age groups (P = 0.66). CONCLUSION: A high prevalence of overweight was observed in the sample of two and three-year-old children, with practically no malnutrition, thus showing that a significant nutritional transition may already be occurring, even in medium-sized cities of developing countries.

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Background and Purpose: Oropharyngeal dysphagia is a common manifestation in acute stroke. Aspiration resulting from difficulties in swallowing is a symptom that should be considered due to the frequent occurrence of aspiration pneumonia that could influence the patient's recovery as it causes clinical complications and could even lead to the patient's death. The early clinical evaluation of swallowing disorders can help define approaches and avoid oral feeding, which may be detrimental to the patient. This study aimed to create an algorithm to identify patients at risk of developing dysphagia following acute ischemic stroke in order to be able to decide on the safest way of feeding and minimize the complications of stroke using the National Institutes of Health Stroke Scale (NHISS). Methods: Clinical assessment of swallowing was performed in 50 patients admitted to the emergency unit of the University Hospital, Faculty of Medicine of Ribeirao Preto, Sao Paulo, Brazil, with a diagnosis of ischemic stroke, within 48 h after the beginning of symptoms. Patients, 25 females and 25 males with a mean age of 64.90 years (range 26-91 years), were evaluated consecutively. An anamnesis was taken before the patient's participation in the study in order to exclude a prior history of deglutition difficulties. For the functional assessment of swallowing, three food consistencies were used, i.e. pasty, liquid and solid. After clinical evaluation, we concluded whether there was dysphagia. For statistical analysis we used the Fisher exact test, verifying the association between the variables. To assess whether the NIHSS score characterizes a risk factor for dysphagia, a receiver operational characteristics curve was constructed to obtain characteristics for sensitivity and specificity. Results: Dysphagia was present in 32% of the patients. The clinical evaluation is a reliable method of detection of swallowing difficulties. However, the predictors of risk for the swallowing function must be balanced, and the level of consciousness and the presence of preexisting comorbidities should be considered. Gender, age and cerebral hemisphere involved were not significantly associated with the presence of dysphagia. NIHSS, Glasgow Coma Scale, and speech and language changes had a statistically significant predictive value for the presence of dysphagia. Conclusions: The NIHSS is highly sensitive (88%) and specific (85%) in detecting dysphagia; a score of 12 may be considered as the cutoff value. The creation of an algorithm to detect dysphagia in acute ischemic stroke appears to be useful in selecting the optimal feeding route while awaiting a specialized evaluation. Copyright (C) 2012 S. Karger AG, Basel

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Objective: to determine the ability of the reduced form of a screening instrument, the Patient Health Questionnaire-2 (PHQ-2), to assess the presence of depressive disorders in patients admitted to a general hospital. Method: A sample of 227 patients admitted to the clinical wards of a Brazilian general university hospital were assessed with Module A of the Diagnostic Structured Interview for the DSM-IV (SCID-IV) and filled out the PHQ-9 and PHQ-2. Results: The PHQ-2 demonstrated an area under the ROC curve of 0.89 (p < 0.0001), with a cutoff point of three or more being the one that best equilibrated the sensitivity (0.86) and specificity (0.75) values. The agreement index between the PHQ-2 and module A of SCID-W was 78.4% and the Kappa value was 0.51. Regarding reliability, the Cronbach alpha value obtained was 0.64 and the intraclass correlation coefficient was 0.52. Conclusion: PHQ-2 proved to be an instrument with good psychometric properties comparable to those of PHQ-9, being superior to the latter regarding the rate of false-positive results. In addition, it is a brief instrument that elicits little resistance on the part of the patient, being inexpensive and requiring little time, thus being of important help to the treatment teams for the detection of depressive disorder, being suitable for incorporation into hospital admission protocols and thus possibly favoring more immediate interventions. (Int'l J. Psychiatry in Medicine 2012;44:141-148)

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Using a first-principles theoretical model the adsorption of a methyl radical on different sized silver nanoparticles is compared to the adsorption of the same radical on model surfaces. Calculations of our structural, dynamical and electronic properties indicated that small changes in the local environment will lead to small changes in infrared (IR) wavenumbers, but in dramatic changes in the IR signal. Our calculations indicate the lower the adsorption site coordination, the higher is the signal strength, suggesting that small changes in the electronic charge distribution will result in bigger changes in the polarizability and hence in the spectroscopic signal intensity. This effect explains, among others, the signal magnification observed for nanoparticles in surface enhanced Raman spectroscopic (SERS) experiments.

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BACKGROUND: Brazilian blood centers ask candidate blood donors about the number of sexual partners in the past 12 months. Candidates who report a number over the limit are deferred. We studied the implications of this practice on blood safety. STUDY DESIGN AND METHODS: We analyzed demographic characteristics, number of heterosexual partners, and disease marker rates among 689,868 donations from three Brazilian centers between July 2007 and December 2009. Donors were grouped based on maximum number of partners allowed in the past 12 months for each center. Chi-square and logistic regression analysis were conducted to examine associations between demographic characteristics, number of sex partners, and individual and overall positive markers rates for human immunodeficiency virus (HIV), human T-lymphotropic virus Types 1 and 2, hepatitis B virus, hepatitis C virus, and syphilis. RESULTS: First-time, younger, and more educated donors were associated with a higher number of recent sexual partners, as was male sex in Sao Paulo and Recife (p < 0.001). Serologic markers for HIV and syphilis and overall were associated with multiple partners in Sao Paulo and Recife (p < 0.001), but not in Belo Horizonte (p = 0.05, p = 0.94, and p = 0.75, respectively). In logistic regression analysis, number of recent sexual partners was associated with positive serologic markers (adjusted odds ratio [AOR], 1.2-1.5), especially HIV (AOR, 1.9-4.4). CONCLUSIONS: Number of recent heterosexual partners was associated with HIV positivity and overall rates of serologic markers of sexually transmitted infections. The association was not consistent across centers, making it difficult to define the best cutoff value. These findings suggest the use of recent heterosexual contacts as a potentially important deferral criterion to improve blood safety in Brazil.

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Objectives: This study aimed to evaluate a panel of proinflammatory and antiinflammatory cytokines in noncomplicated and complicated parapneumonic pleural effusions and to correlate their levels with pleural fluid biochemical parameters. Methods: Serum and pleural effusion were collected from 60 patients with noncomplicated (n = 26) or complicated (n = 34) parapneumonic effusions and assayed for cytologic, biochemical, and proinflammatory and antiinflammatory cytokines. Student t test was used to compare serum and pleural fluid values, Spearman correlation to analyze the relationship between pleural fluid cytokines and biochemical parameters, and accuracy of pleural fluid cytokine levels to determine the optimal cutoff value for identification of complicated effusions. Corrections for multiple comparisons were applied and a P value < .05 was accepted as significant. Results: Serum and pleural fluid cytokine levels of IL-8, vascular endothelial growth factor (VEGF), IL-10, and tumor necrosis factor (TNF) soluble receptor (sR) II were similar between groups. In contrast, complicated effusions had higher levels of pleural fluid IL-1 beta, IL-1 receptor antagonist (ra), and TNF sRI. Negative correlations were found between pleural fluid glucose with IL-1 beta and TNF sRI and positive correlations between lactic dehydrogenate (LDH) with IL-1 beta, IL-8, and VEGF. Pleural fluid levels of IL-1 beta, IL-1ra, and TNF sRI were more accurate than IL-8, VEGF, IL-10, and TNF sRII in discriminating complicated effusions. Conclusions: Both proinflammatory and antiinflammatory cytokine levels in pleural fluid are elevated in complicated in comparison with noncomplicated parapneumonic pleural effusions, and they correlate with both pleural fluid glucose and LDH levels. IL-1 beta, IL-1ra, and TNF sRI had higher sensitivity and specificity than IL-8, VEGF, IL-10, and TNF sRII in discriminating complicated effusions. CHEST 2012; 141( 1):183-189