Estudo de tensões residuais em juntas soldadas utilizando o método dos elementos finitos

Pós-graduação em Engenharia Mecânica - FEG

Validation of cone-beam computed tomography and magnetic resonance imaging of the porcine spine: a comparative study with multidetector computed tomography and anatomical specimens

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

c ̂-Axis resistivity in graphite-AlCl3 as found by CESR measurements

We report the absolute values of the c ̂-axis resistivity obtained from conduction electron spin resonance (CESR) experiments at various temperatures for a graphite-AlCl3 stage 2 compound. The agreement with d.c. measurements is quite good. The temperature dependence of the c ̂-axis resistivity previously obtained from CESR for graphite-AlCl3 is revised. © 1990.

Qualidade estrutural em latossolos compactados cultivados com milho

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

O efeito da contração muscular de membros superiores sobre o sistema nervoso autonômico de pessoas com fatores de risco cardiovascular

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

O efeito da contração muscular de membros superiores sobre o sistema nervoso autonômico de pessoas com fatores de risco cardiovascular

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Diltiazem como alternativa ao betabloqueador na angiotomografia de artérias coronárias

FUNDAMENTO: A redução da frequência cardíaca (FC) na angiografia por tomografia das artérias coronarianas (ATCCor) é fundamental para a qualidade de imagem. A eficácia dos bloqueadores de cálcio como alternativas para pacientes com contraindicações aos betabloqueadores não foi definida. OBJETIVOS: Comparar a eficácia na redução da FC e variabilidade RR do metoprolol e diltiazem na ATCCor. MÉTODOS: Estudo prospectivo, randomizado, aberto, incluiu pacientes com indicação clínica de ATCCor, em ritmo sinusal, com FC>70bpm e sem uso de agentes que interferissem com a FC. Cinquenta pacientes foram randomizados para grupos: metoprolol IV 5-15 mg ou até FC≤60 bpm(M), e diltiazem IV 0,25-0,60mg/kg ou até FC≤60 bpm (D). Pressão arterial (PA) e FC foram aferidas na condição basal, 1min, 3min e 5min após agentes, na aquisição e após ATCCor. RESULTADOS: A redução da FC em valores absolutos foi maior no grupo M que no grupo D (1, 3, 5min, aquisição e pós-exame). A redução percentual da FC foi significativamente maior no grupo M apenas no 1 min e 3 min após início dos agentes. Não houve diferença no 5 min, durante a aquisição e após exame. A variabilidade RR percentual do grupo D foi estatisticamente menor do que a do grupo M durante a aquisição (variabilidade RR/ FC média da aquisição). Um único caso de BAV, 2:1 Mobitz I, revertido espontaneamente ocorreu (grupo D). CONCLUSÃO: Concluímos que o diltiazem é uma alternativa eficaz e segura aos betabloqueadores na redução da FC na realização de angiografia por tomografia computadorizada das artérias coronarianas. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0)

A new method to analyze the subjective visual vertical in patients with bilateral vestibular dysfunction

OBJECTIVE: The aim of this study was to assess the subjective visual vertical in patients with bilateral vestibular dysfunction and to propose a new method to analyze subjective visual vertical data in these patients. METHODS: Static subjective visual vertical tests were performed in 40 subjects split into two groups. Group A consisted of 20 healthy volunteers, and Group B consisted of 20 patients with bilateral vestibular dysfunction. Each patient performed six measurements of the subjective visual vertical test, and the mean values were calculated and analyzed. RESULTS: Analyses of the numerical values of subjective visual vertical deviations (the conventional method of analysis) showed that the mean deviation was 0.326 +/- 1.13 degrees in Group A and 0.301 +/- 1.87 degrees in Group B. However, by analyzing the absolute values of the subjective visual vertical (the new method of analysis proposed), the mean deviation became 1.35 +/- 0.48 degrees in Group A and 2.152 +/- 0.93 degrees in Group B. The difference in subjective visual vertical deviations between groups was statistically significant (p < 0.05) only when the absolute values and the range of deviations were considered. CONCLUSION: An analysis of the absolute values of the subjective visual vertical more accurately reflected the visual vertical misperception in patients with bilateral vestibular dysfunction.

Bioelectrical impedance vector analysis (BIVA) in stable preterm newborns

Objective: To observe the behavior of the plotted vectors on the RXc (R - resistance - and Xc - reactance corrected for body height/length) graph through bioelectrical impedance analysis (BIVA) and phase angle (PA) values in stable premature infants, considering the hypothesis that preterm infants present vector behavior on BIVA suggestive of less total body water and soft tissues, compared to reference data for term infants. Methods: Cross-sectional study, including preterm neonates of both genders, in-patients admitted to an intermediate care unit at a tertiary care hospital. Data on delivery, diet and bioelectrical impedance (800 mA, 50 kHz) were collected. The graphs and vector analysis were performed with the BIVA software. Results: A total of 108 preterm infants were studied, separated according to age (< 7 days and >= 7 days). Most of the premature babies were without the normal range (above the 95% tolerance intervals) existing in literature for term newborn infants and there was a tendency to dispersion of the points in the upper right quadrant, RXc plan. The PA was 4.92 degrees (+/- 2.18) for newborns < 7 days and 4.34 degrees (+/- 2.37) for newborns >= 7 days. Conclusion: Premature infants behave similarly in terms of BIVA and most of them have less absolute body water, presenting less fat free mass and fat mass in absolute values, compared to term newborn infants.

Effects of circuit-based exercise programs on the body composition of elderly obese women

Aim: The aim of this study was to investigate the impact of circuit-based exercise on the body composition in obese older women by focusing on physical exercise and body weight (BW) gain control in older people. Methods: Seventy older women (>60 years old) voluntarily took part in the study. Participants were randomized into six different groups according to body mass index (BMI): appropriate weight (AW) control (AWC) and trained (AWT) groups, overweight (OW) control (OWC) and trained (OWT) groups, and obesity (O) control (OC) and trained (OT) groups. The exercise program consisted of 50 minutes of exercise three times per week for 12 weeks. The exercises were alternated between upper and lower body using rest between sets for 40 seconds with intensity controlled by heart rate (70% of work). The contraction time established was 5 seconds to eccentric and concentric muscular action phase. The following anthropometric parameters were evaluated: height (m), body weight (BW, kg), body fat (BF, %), fat mass (FM, kg), lean mass (LM, kg), and BMI (kg/m(2)). Results: The values (mean +/- standard deviation [SD]) of relative changes to BW (-8.0% +/- 0.8%), BF (-21.4% +/- 2.1%), LM (3.0% +/- 0.3%), and FM (-31.2% +/- 3.0%) to the OT group were higher (P < .05) than in the AWT (BW: -2.0% +/- 1.1%; BF: -4.6% +/- 1.8%; FM: -7.0% +/- 2.8%; LM: 0.2% +/- 1.1%) and OWT (BW: -4.5% +/- 1.0%; BF: -11.0% +/- 2.2%; FM: -16.1% +/- 3.2%; LM: -0.2% +/- 1.0%) groups; additionally, no differences were found for C groups. While reduction (P < .03) in BMI according to absolute values was observed for all trained groups (AWT: 22 +/- 1 versus 21 +/- 1; OWT: 27 +/- 1 versus 25 +/- 1, OT: 34 +/- 1 versus 30 +/- 1) after training, no differences were found for C groups. Conclusion: In summary, circuit-based exercise is an effective method for promoting reduction in anthropometrics parameters in obese older women.

Forced Desynchronization of Activity Rhythms in a Model of Chronic Jet Lag in Mice

We studied locomotor activity rhythms of C57/Bl6 mice under a chronic jet lag (CJL) protocol (ChrA(6/2)), which consisted of 6-hour phase advances of the light-dark schedule (LD) every 2 days. Through periodogram analysis, we found 2 components of the activity rhythm: a short-period component (21.01 +/- 0.04 h) that was entrained by the LD schedule and a long-period component (24.68 +/- 0.26 h). We developed a mathematical model comprising 2 coupled circadian oscillators that was tested experimentally with different CJL schedules. Our simulations suggested that under CJL, the system behaves as if it were under a zeitgeber with a period determined by (24 -[phase shift size/days between shifts]). Desynchronization within the system arises according to whether this effective zeitgeber is inside or outside the range of entrainment of the oscillators. In this sense, ChrA(6/2) is interpreted as a (24 - 6/2 = 21 h) zeitgeber, and simulations predicted the behavior of mice under other CJL schedules with an effective 21-hour zeitgeber. Animals studied under an asymmetric T = 21 h zeitgeber (carried out by a 3-hour shortening of every dark phase) showed 2 activity components as observed under ChrA(6/2): an entrained short-period (21.01 +/- 0.03 h) and a long-period component (23.93 +/- 0.31 h). Internal desynchronization was lost when mice were subjected to 9-hour advances every 3 days, a possibility also contemplated by the simulations. Simulations also predicted that desynchronization should be less prevalent under delaying than under advancing CJL. Indeed, most mice subjected to 6-hour delay shifts every 2 days (an effective 27-hour zeitgeber) displayed a single entrained activity component (26.92 +/- 0.11 h). Our results demonstrate that the disruption provoked by CJL schedules is not dependent on the phase-shift magnitude or the frequency of the shifts separately but on the combination of both, through its ratio and additionally on their absolute values. In this study, we present a novel model of forced desynchronization in mice under a specific CJL schedule; in addition, our model provides theoretical tools for the evaluation of circadian disruption under CJL conditions that are currently used in circadian research.

Reliability in kimono grip strength tests and comparison between elite and non-elite Brazilian jiu-jitsu players

Background and Study Aim: The grip strength endurance is important for Brazilian Jiu-Jitsu (BJJ). Thus, the aims of this study were: a) to test the reliability of two kimono grip strength tests named maximum static lift (MSL) and maximum number of repetitions (MNR) and b) to examine differences between elite and non-elite BJJ players in these tests. Material/Methods: Thirty BJJ players participated into two phases: "A" to test reliability and "B" to compare elite and non-elite. In phase A, twenty participants performed the MSL and, 15 min later, the MNR in two occasions with 24-h interval. In phase B, ten other BJJ practitioners (non-elite) and ten athletes (elite) performed the same tests. The intraclass correlation coefficient (ICC) two way fixed model (3,1), Bland-Altman plot and the limits of agreement were used to test reliability, correlation between the tests were evaluated by Pearson correlations and independent T test (P<0.05) was utilized to compare elite vs. non-elite. Results: The ICC was high for repeated measurements on different days of phase A (MSL: r=0.99 and MNR: r=0.97). Limits of agreement for time of suspension were -6.9 to 2.4-s, with a mean difference of -2.3 s (CI: -3.3 to -1.2-s), while for number of repetitions the limits of agreement were -2.9 to 2.3-rep, with a mean difference of -0.3-rep (CI: -0.9 to 0.3-rep). In phase B, elite presented better performance for both tests (P<0.05) compared to non-elite (56 +/- 10-s vs. 37 +/- 11-s in MSL and 15 +/- 4-rep vs. 8 +/- 3-rep in MNR). Moderate correlation were found between MSL and MNR for absolute values during test (r=0.475; p=0.034), and retest phases (r=0.489; p=0.029), while moderate and high correlations in the test (r=0.615; p=0.004) and retest phases (r=0.716; p=0.001) were found for relative values, respectively. Conclusions: These proposed tests are reliable and both static and dynamic grip strength endurance tests seem to differentiate BJJ athletes from different levels.

Limitations of Neoseiulus baraki and Proctolaelaps bickleyi as control agents of Aceria guerreronis

Several predatory mites have been found in association with the coconut mite, Aceria guerreronis Keifer, in northeast Brazil. However, the latter still causes damage to coconut in that region. The objectives of this work were to compare the frequencies of occurrence of Neoseiulus (Phytoseiidae) and Proctolaelaps (Melicharidae) species on standing and aborted coconuts in coastal Pernambuco State, northeast Brazil and to analyze their possible limitations as control agents of the coconut mite, based on evaluations of the restrictions they may have to access the microhabitat inhabited by the pest and their functional and reproductive responses to increasing densities of the latter. Neoseiulus baraki (Athias-Henriot) was found mostly on standing coconuts whereas Proctolaelaps bickleyi (Bram) was found mostly on aborted coconuts. Measurements of the entrance to the microhabitat occupied by the coconut mite, between the bracts and the subjacent fruit surface, showed that this different pattern of predator prevalence could be related to predator sizes, although other environmental factors could not be disregarded. Progressively higher predation rate of N. baraki was observed up to an experimental density that corresponded to 1,200 coconut mites per fruit, which is close to the average number determined in northeast Brazil, reducing slightly afterwards. Predation rate of P. bickleyi reduced consistently but slightly with increasing prey densities, but in absolute values, rates were always much higher than determined for N. baraki. The excessively high killing capacity of P. bickleyi, probably related to its high feeding requirement, may be detrimental in terms of stability. In fact, such high requirement for food suggests that P. bickleyi might not have a strong relation with the coconut mite and that the latter may not be its main food source under natural conditions. It is concluded that body sizes of both predators and the exceedingly high feeding requirement of P. bickleyi may limit their performance as control agents of the coconut mite.

Application of the Z-scan technique to determine the optical Kerr coefficient and two-photon absorption coefficient of magnetite nanoparticles colloidal suspension

We investigate the occurrence of the optical Kerr effect and two-photon absorption when an oil-based magnetic Fe3O4 nanoparticles colloidal suspension is illuminated with high intensity femtosecond laser pulses. The frequency of the pulses is controlled and the Z-scan technique is employed in our measurements of the nonlinear optical Kerr coefficient (n(2)) and two-photon absorption coefficient (beta). From these values it was possible to calculate the real and imaginary parts of the third-order susceptibility. We observed that increasing the pulse frequency, additional physical processes take place, increasing artificially the absolute values of n(2) and beta. The experimental conditions are discussed to assure the obtention of reliable values of these nonlinear optical parameters, which may be useful in all-optical switching and optical power limiting applications. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4723829]

The consequences of growth hormone-releasing hormone receptor haploinsufficiency for bone quality and insulin resistance

Objective Growth hormone (GH)/insulin-like growth factor (IGF) axis and insulin are key determinants of bone remodelling. Homozygous mutations in the GH-releasing hormone receptor (GHRHR) gene (GHRHR) are a frequent cause of genetic isolated GH deficiency (IGHD). Heterozygosity for GHRHR mutation causes changes in body composition and possibly an increase in insulin sensitivity, but its effects on bone quality are still unknown. The objective of this study was to assess the bone quality and metabolism and its correlation with insulin sensitivity in subjects heterozygous for a null mutation in the GHRHR. Patients and methods A cross-sectional study was performed on 76 normal subjects (68.4% females) (N/N) and 64 individuals (64.1% females) heterozygous for a mutation in the GHRHR (MUT/N). Anthropometric features, quantitative ultrasound (QUS) of the heel, bone markers [osteocalcin (OC) and CrossLaps], IGF-I, glucose and insulin were measured, and homeostasis model assessment of insulin resistance (HOMAIR) was calculated. Results There were no differences in age or height between the two groups, but weight (P = 0.007) and BMI (P = 0.001) were lower in MUT/N. There were no differences in serum levels of IGF-I, glucose, T-score or absolute values of stiffness and OC, but insulin (P = 0.01), HOMAIR (P = 0.01) and CrossLaps (P = 0.01) were lower in MUT/N. There was no correlation between OC and glucose, OC and HOMAIR in the 140 individuals as a whole or in the separate MUT/N or N/N groups. Conclusions This study suggests that one allele mutation in the GHRHR gene has a greater impact on energy metabolism than on bone quality.