995 resultados para Lower limits


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I ntroduction: The assessment of respiratory muscle strength is important in the diagnosis and monitoring of the respiratory muscles weakness of respiratory and neuromuscular diseases. However, there are still no studies that provide predictive equations and reference values for maximal respiratory pressures for children in our population. Aim: The purpose of this study was to propose predictive equations for maximal respiratory pressures in healthy school children. Method: This is an observational cross-sectional study. 144 healthy children were assessed. They were students from public and private schools in the city of Natal /RN (63 boys and 81 girls), subdivided in age groups of 7-8 and 9-11 years. The students presented the BMI, for age and sex, between 5 and 85 percentile. Maximal respiratory pressures were measured with the digital manometer MVD300 (Globalmed ®). The maximal inspiratory pressure (MIP) and maximal expiratory pressures (MEP) were measured from residual volume and total lung capacity, respectively. The data were analyzed using the SPSS Statistics 15.0 software (Statistical Package for Social Science) by assigning the significance level of 5%. Descriptive analysis was expressed as mean and standard deviation. T'Student test was used for unpaired comparison of averages of the variables. The comparison of measurements obtained with the predicted values in previous studies was performed using the paired t'Student test. The Pearson correlation test was used to verify the correlation of MRP's with the independent variables (age, sex, weight and height). For the equations analysis the stepwise linear regression was used. Results: By analyzing the data, we observed that in the age range studied MIP was significantly higher in boys. The MEP did not differ between boys and girls aged 7 to 8 years, the reverse occurred in the age between 9 and 11 years. The boys had a significant increase in respiratory muscle strength with advancing age. Regardless sex and age, MEP was always higher than the MIP. The reference values found in this study are similar to a sample of Spanish and Canadian children. The two models proposed in previous studies with children from other countries were not able to consistently predict the values observed in this studied population. The variables sex, age and weight correlated with MIP, whereas the MEP was also correlated with height. However, in the regression models proposed in this study, only gender and age were kept exerting influence on the variability of maximal inspiratory and expiratory pressures. Conclusion: This study provides reference values, lower limits of normality and proposes two models that allow predicting, through the independent variables, sex and age, the value of maximal static respiratory pressures in healthy children aged between 7 and 11 years old

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Introduction: The reference values and prediction equations for maximal respiratory pressures (MRP) differ significantly between the available studies. This large discrepancy can be attributed to the different methodologies proposed. Although the importance of MRP is widely recognized, there are no Brazilian studies that provide predictive equations and reference values for PRM adolescents. Objectives: The purpose of this study was to provide normal values and propose predictive equations for maximal static respiratory pressures of Brazilian adolescents. Methods: An observational cross-sectional study, which evaluated 182 adolescents of both sexes aged between 12 and 18 years, enrolled in schools of the state and private in the city of Natal / RN. The selection of schools and participants of the study was randomly through a lottery system. The spirometric evaluation was performed through the digital spirometer One Flow FVC prior to the assessment of respiratory muscle strength. The MICs were measured with MVD digital manometer 300. Statistical analysis was performed using the SPSS 17.0 software STATISTICS, assigning the significance level of 5%. The normality of data distribution was verified using the Kolmogorov-Smirnov (KS). The descriptive analysis was expressed as mean and standard deviation. We used one-way ANOVA test to verify the difference of the averages of MRPs between age and gender and comparing the averages of MRPs between levels of physical activity. The test t'Student unpaired compared the averages of MRPs being ages and sexes. The comparison of mean values obtained in this study PRM with the values predicted using the equations mentioned above was relizada by testing paired t'Student. To verify the correlation between the PRM and the independent variables (age, weight, height) was used Pearson correlation test. Levene's test evaluated the homogeneity of variance. To obtain predictive equations analysis was used stepwise multiple linear regression. Results: There was no significant difference in mean age between the PRM. The male adolescents, regardless of age, showed superiority in MRP values when compared to the opposite sex. Weight, height and sex correlated with the PRM. Regression analysis suggested in this study, pointed out that the weight and sex had an influence in MIP and MEP only in relation to sex influenced. The mean for each PRM adolescents classified as very active were superior to those observed in adolescents classified as irregularly active. Conclusion: This study provides reference values and two models of predictive equations for maximal inspiratory and expiratory pressures, and to establish the lower limits of normality that will serve as an indispensable condition for careful evaluation of respiratory muscle strength in Brazilian adolescents

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Introduction: The leukemias are the most common malignancy in children and adolescents. With the improvement in outcomes, there is a need to consider the morbidity to generate the protocols used in children under treatment. Aim: To evaluate pulmonary function in children with acute leukemia. Method: This study is an observational cross sectional. We evaluated 34 children distributed in groups A and B. Group A comprised 17 children with acute leukemia in the maintenance phase of chemotherapy treatment and group B with 17 healthy students from the public in the city of Natal / RN, matched for gender, age and height. The thoracic mobility was evaluated by thoracic expansion in the axillary and xiphoid levels. Spirometry was measured using a spirometer Microloop Viasys ® following the rules of the ATS and ERS. Maximal respiratory pressures were measured with digital manometer MVD300 (Globalmed ®). The maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were measured from residual volume and total lung capacity, respectively. The data were analyzed using the SPSS 17.0 software assigning the significance level of 5%. Descriptive analysis was expressed as mean and standard deviation. T'student test was used to compare unpaired values found in group A with group B values, as well as with the reference values used. To compare the respiratory coefficients in the axillary level with the xiphoid in each group, we used paired testing t student. Results: Group A was significantly decreased thoracic mobility and MIP compared to group B, and MIP compared to baseline. There was no significant difference between spirometric data from both groups and the values of group A with the reference values Mallozi (1995). There was no significant difference between the MIP and MEP values and lower limits of reference proposed by Borja (2011). Conclusion: Children with acute leukemia, myeloid or lymphoid, during maintenance phase of chemotherapy treatment have reduced thoracic mobility and MIP. However, to date, completion of clinical treatment, the spirometric variables and the strength of the expiratory muscles appear to remain preserved in children between five and ten years

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We report on a search for pair production of first-generation scalar leptoquarks (LQ) in p (p) over bar collisions at root s=1.96 TeV using an integrated luminosity of 252 pb(-1) collected at the Fermilab Tevatron collider by the D0 detector. We observe no evidence for LQ production in the topologies arising from LQ(LQ) over bar -> eqeq and LQ(LQ) over bar -> eq nu q, and derive 95% C.L. lower limits on the LQ mass as a function of beta, where beta is the branching fraction for LQ -> eq. The limits are 241 and 218 GeV/c(2) for beta=1 and 0.5, respectively. These results are combined with those obtained by D0 at root s=1.8 TeV, which increases these LQ mass limits to 256 and 234 GeV/c(2).

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We report on a search for the pair production of second generation scalar leptoquarks (LQ(2)) in p (p) over bar collisions at the center-of-mass energy, root s = 1.96 TeV, using data corresponding to an integrated luminosity of 294 19 pb(-1) recorded with the DO detector. No evidence for a leptoquark signal in the LQ(2)LQ(2) -> mu q mu q channel has been observed, and upper bounds on the product of cross section times branching fraction were set. This yields lower mass limits of m(LQ2) > 247 GeV/c(2) for beta = B(LQ(2) -> mu q) = 1 and m(LQ2) > 182 GeV/c(2) for beta = 1/2. Combining these limits with previous DO results, the lower limits on the mass of a second generation scalar leptoquark are m(LQ2) > 251 GeV/c(2) and m(LQ2) > 204 GeV/c(2) for beta = I and beta = 1/2, respectively. (c) 2006 Elsevier B.V. All rights reserved.

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We report the first direct search for the Kaluza-Klein (KK) modes of Randall-Sundrum gravitons using dielectron, dimuon, and diphoton events observed with the D0 detector operating at the Fermilab Tevatron p (p) over bar Collider at root s = 1: 96 TeV. No evidence for resonant production of gravitons has been found in the data corresponding to an integrated luminosity of approximate to 260 pb(-1). Lower limits on the mass of the first KK mode at the 95% C. L. have been set between 250 and 785 GeV, depending on its coupling to standard model particles.

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The results of a search for squarks and gluinos using data from p (p) over bar collisions recorded at a center-of-mass energy of 1.96 TeV by the DO detector at the Fermilab Tevatron Collider are reported. The topologies analyzed consist of acoplanar-jet and multijet events with large missing transverse energy. No evidence for the production of squarks or gluinos was found in a data sample of 310pb(-1). Lower limits of 325 and 241 GeV were derived at the 95% C.L. on the squark and gluino masses, respectively, within the framework of minimal supergravity with tan beta=3, A(0) = 0, and mu < 0. (c) 2006 Elsevier B.V. All rights reserved.

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lWe report on a search for second generation leptoquarks (LQ(2)) which decay into a muon plus quark in (p) over barp collisions at a center-of-mass energy of root s = 1.96 TeV in the DO detector using an integrated luminosity of about 300 pb(-1). No evidence for a leptoquark signal is observed and an upper bound on the product of the cross section for single leptoquark production times branching fraction into a quark and a muon was determined for second generation scalar leptoquaiks as a function of the leptoquark mass. This result has been combined with a previously published DO search for leptoquark pair production to obtain leptoquark mass limits as a function of the leptoquark-muon-quark coupling, lambda. Assuming lambda = 1, lower limits on the mass of a second generation scalar leptoquark coupling to a u quark and a muon are m(LQ2) > 274 GeV and m(LQ2) > 226 GeV for beta = 1 and beta = 1/2, respectively. (c) 2007 Elsevier B.V. All rights reserved.

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We present the results of a search for the effects of large extra spatial dimensions in p (p) over bar collisions at root s = 1: 96 TeV in events containing a pair of energetic muons. The data correspond to 246 pb(-1) of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider. Good agreement with the expected background was found, yielding no evidence for large extra dimensions. We set 95% C. L. lower limits on the fundamental Planck scale between 0.85 and 1.27 TeV within several formalisms. These are the most stringent limits achieved in the dimuon channel to date.

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We present the measurement of R = B(t -> Wb)/B(t -> Wq) in pp collisions at root s = 1.96 TeV, using 230 pb(-1) of data collected by the DO experiment at the Fermilab Tevatron Collider. We fit simultaneously R and the number (N-tt) of selected top quark pairs (tt), to the number of identified b-quark jets in events with one electron or one muon, three or more jets, and high transverse energy imbalance. To improve sensitivity, kinematical properties of events with no identified b-quark jets are included in the fit. We measure R = 1.03(-0.17)(0.19) (stat + syst), in good agreement with the standard model. We set lower limits of R > 0.61 and vertical bar V-tb vertical bar > 0.78 at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.

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We report the results of a search for supersymmetry (SUSY) with gauge-mediated breaking in the missing transverse energy distribution of inclusive diphoton events using 263 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2004. No excess is observed above the background expected from standard model processes, and lower limits on the masses of the lightest neutralino and chargino of about 108 and 195 GeV, respectively, are set at the 95% confidence level. These are the most stringent limits to date for models with gauge-mediated SUSY breaking with a short-lived neutralino as the next-to-lightest SUSY particle.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)