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Background: The resting of the respiratory musculature after undergoing the spontaneous breathing trial (SBT) to prevent extubation failures in critically ill patients needs to be studied further.Research Question: Is the reconnection to mechanical ventilation (MV) for 1 h after a successful SBT able to reduce the risk of reintubation?Study Design and Methods: Randomized clinical trial conducted in four ICUs between August 2018 and July 2019. Candidates for tracheal extubation who met all screening criteria for weaning were included. After achieving success in the SBT using a T-tube, the patients were randomized to the following groups: direct extubation (DE) or extubation after reconnection to MV for 1 h (R1h). The primary outcome was reintubation within 48 h.Results: Among the 336 patients studied (women, 41.1%; median age, 59 years [interquartile range, 45-70 years]), 12.9% (22/171) in the R1h group required reintubation within 48 h vs 18.2% (30/165) in the DE group (risk difference, 5.3 [95% CI, -2.49 to 13.12]; P = .18). No differences were found in mortality, length of ICU or hospital stay, causes of reintubation, or signs of extubation failure. A prespecified exploratory analysis showed that among the 233 patients (69.3%) who were ventilated for more than 72 h, the incidence of reintubation was 12.7% (15/118) in the R1h group compared with 22.6% (26/115) observed in the DE group (P = .04).Interpretation: Reconnection to MV after a successful SBT, compared with DE, did not result in a statistically significant reduction in the risk of reintubation in mechanically ventilated patients. Subgroup exploratory findings suggest that the strategy may benefit patients who were ventilated for more than 72 h, which should be confirmed in further studies.Trial Registry: Brazilian Clinical Trials Registry; No.: RBR-3x8nxn; URL: www.ensaiosclinicos.gov.br. [ABSTRACT FROM AUTHOR]

Studies focusing on human rhythmicity show that human circadian rhythm suffers constant changes across lifespan. Changes in rest-activity patterns can be studied through nonparametric variables of actigraphy: L5 (an individual's least active 5 h), M10 (an individual's most active 10 h) and RA (relative amplitude of the rest-activity rhythm). The variable RA is the normalized difference between L5 and M10 - the higher the RA, the greater the difference between these two variables. This study used the data bank of the Human Chronobiology Laboratory of Federal University of Paraná (Brazil). It analyzed actimetric data of 93 children between 4 and 11 years of age in their naturalistic context in order to describe the development of nonparametric variables. Correlation between age and L5 was significantly negative (rho = - 0.29, p = 0.004), while correlation between age and RA was significantly positive (rho = 0.31, p = 0.003). The variables M10, sL5 (start of L5) and sM10 (start of M10) did not show significant correlation to age. Furthermore, there were no statistical differences between genders. The population of this study, healthy children, has been poorly assessed by similar literature. Through our results, we have demonstrated that, as children age, L5 significantly decreases, which reflects a smaller fragmentation of circadian rhythm. As an expected consequence, RA significantly increases. In other words, these nonparametric variables of actimetry successfully demonstrate that children tend to reduce nocturnal activity as they age, a phenomenon that reflects the ongoing consolidation of circadian rhythm.

The fractional amplitude of low-frequency fluctuations (fALFFs) of the BOLD signal have been successfully applied as exploratory tools in neuroimaging. This metric has been useful in mapping brain functional changes in many clinical populations. However, little is known about the neurophysiological correlates of fALFF. This study aimed at demonstrating that fALFF is related to local network centrality during childhood and adolescence. The establishment of this relationship is fundamental to provide a more meaningful explanation to previous clinical and neurodevelopmental studies based on fALFF. Our findings show a correlation of ∼0.5 between these two metrics at a group level, which is a finding replicated in four large independent samples. However, when considering the across-subject and intra-subject correlations between the two metrics, the correlation is much lower, probably due to the low signal-to-noise ratio. Moreover, we found that regions with high fALFF and degree centrality overlapped modestly, particularly the posterior cingulate/precuneus and lateral parietal cortices.

Despite the importance of hydration during exercise, the impact of ingesting water or isotonic solution during and after exercise on the regulation of autonomic modulation is unclear. The study aimed to compare the effect of ingesting water or isotonic solution (Gatorade®, Brazil) on cardiac autonomic modulation in young people after submaximal aerobic exercise. Thirty-one young men were subjected to a protocol consisting of 4 steps: 1) incremental test, 2) control protocol without hydration, 3) protocol with ingestion of water, and 4) protocol with ingestion of isotonic solution. The protocol consisted of 10 min of rest, 90 min of treadmill exercise at 60% VO2peak, and 60 min of recovery at rest. In the hydration protocols, hydration occurred during and after exercise, every 15 min beginning after the 15th minute of exercise, with the amount ingested proportional to body mass lost in the control protocol. Autonomic modulation was evaluated by heart rate variability. The hydration protocols promoted a more efficient recovery of autonomic modulation, and for the exercise performed, regardless of the hydration administered, the effect on autonomic modulation was similar.

Late preterm birth is increasingly recognized as a risk factor for cognitive and social deficits. The prefrontal cortex is particularly vulnerable to injury in late prematurity because of its protracted development and extensive cortical connections. Our study examined children born late preterm without access to advanced postnatal care to assess structural and functional connectivity related to the prefrontal cortex. Thirty-eight preadolescents [19 born late preterm (34-36 /7 weeks gestational age) and 19 at term] were recruited from a developing community in Brazil. Participants underwent neuropsychological testing. Individuals underwent three-dimensional T1-weighted, diffusion-weighted, and resting state functional MRI. Probabilistic tractography and functional connectivity analyses were carried out using unilateral seeds combining the medial prefrontal cortex and the anterior cingulate cortex. Late preterm children showed increased functional connectivity within regions of the default mode, salience, and central-executive networks from both right and left frontal cortex seeds. Decreased functional connectivity was observed within the right parahippocampal region from left frontal seeding. Probabilistic tractography showed a pattern of decreased streamlines in frontal white matter pathways and the corpus callosum, but also increased streamlines in the left orbitofrontal white matter and the right frontal white matter when seeded from the right. Late preterm children and term control children scored similarly on neuropsychological testing. Prefrontal cortical connectivity is altered in late prematurity, with hyperconnectivity observed in key resting state networks in the absence of neuropsychological deficits. Abnormal structural connectivity indicated by probabilistic tractography suggests subtle changes in white matter development, implying disruption of normal maturation during the late gestational period.

Background: Economic and technological improvements can help increase screen time use among adolescents, but evidence in developing countries is scarce. The aim of this study was to examine changes in TV watching and computer/video game use patterns on week and weekend days after a decade (2001 and 2011), among students in Santa Catarina, southern Brazil., Methods: A comparative analysis of two cross-sectional surveys that included 5 028 and 6 529 students in 2001 and 2011, respectively, aged 15-19 years. The screen time use indicators were self-reported. 95% Confidence intervals were used to compare the prevalence rates. All analyses were separated by gender., Results: After a decade, there was a significant increase in computer/video game use. Inversely, a significant reduction in TV watching was observed, with a similar magnitude to the change in computer/video game use. The worst trends were identified on weekend days., Conclusions: The decrease in TV watching after a decade appears to be compensated by the increase in computer/video game use, both in boys and girls. Interventions are needed to reduce the negative impact of technological improvements in the lifestyles of young people, especially on weekend days., (© The Author 2014. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The autonomic nervous system (ANS) has an important role in physical performance. However, the cardiac ANS activity in high-level track and field athletes has been poorly explored. Thus, we tested the hypothesis that endurance and power athletes would present a markedly different cardiac autonomic control at rest. We analyzed the cardiac ANS by means of time and frequency domains heart rate variability (HRV) analyses and by symbolic analysis. Endurance athletes showed higher pulse interval than power athletes (1,265±126 vs. 1,031±98 ms respectively; p<0.05). No differences were found in time and frequency domains between the groups. However, the LF%, HF% and LF/HF ratio presented high effect sizes (1.46, 1.46 and 1.30, respectively). The symbolic analysis revealed that endurance athletes had higher 2V parasympathetic modulation (36±6.5) than power athletes (24±9.3; p<0.05). A reduced 0V sympathetic modulation was observed in endurance athletes (21±9.9) compared to power athletes (33±11; p<0.05 and ES=1.30). Our results suggest greater parasympathetic modulation and less sympathetic modulation in endurance athletes compared to power athletes. Additionally, the type of HRV analysis needs to be chosen with well-defined criteria and caution because their use in assessing cardiac autonomic modulation can interfere with the interpretation of results. In practical terms, symbolic analysis appears to better discriminate between cardiac autonomic activities of athletes with different training backgrounds than frequency domain analysis., (© Georg Thieme Verlag KG Stuttgart · New York.)

Increased body size in Brachyteles has been regarded as an important evolutionary adaptation that allowed a greater reliance on leaves compared to other more frugivorous Atelidae, but its association with muriqui positional behavior and substrate use is still unknown. Here, we present original data on the feeding and resting postures of the northern muriqui (Brachyteles hypoxanthus) and evaluate predictions about the relationships between body size, postural behavior, and substrate use derived from previously published data for other atelids (e.g. Alouatta, Ateles, and Lagothrix). The study was undertaken from August 2002 to July 2003 on a large group of well-habituated muriquis inhabiting the Reserva Particular do Patrimônio Natural - Felíciano Miguel Abdala in Minas Gerais, Brazil. Consistent with our predictions, we found that B. hypoxanthus was highly suspensory during postural feeding (60.9%) and commonly used tail-hind limb suspension/horizontal tripod (38.0%) or tail-forelimb/hind limb suspension (21.4%). However, although tail-suspensory postures permitted the muriquis to use the terminal canopy and small-sized substrates, these areas were also accessed via tail-assisted above-branch postural behaviors involving multiple substrates. Unexpectedly, tail-suspensory postures were found to be frequently associated with large substrates, tree trunks, and the understory. We suggest that Brachyteles' ability to access food resources from all areas of a feeding tree and from tree crowns at different canopy levels may account for their ability to efficiently exploit food resources in seasonal disturbed forest fragments of the Brazilian Atlantic Forest today., (© 2012 Wiley Periodicals, Inc.)

In Brazil the sugar ethanol industry has had strong growth in the last 10 years, sometimes due to the growing sugar exportation, sometimes due to the alcohol production for automobile fuel and for exportation. Despite the growing mechanization of the raw material harvest (sugar cane), the manual work still persists. The development of this article was based in the application of the OCRA Method in the sugar cane harvesting process, to evaluate the risks to the upper limbs by repetitive movements and epidemiologically prove the ratio risk x harm to the heath of the workers, as well as the probability of developing improvements in the working conditions. The analysis process consists of studying the work organization, the risks to the health of the worker and the distribution of the recovery periods during the working day.

The present study descriptively compares the need for recovery (NFR) among 128 nursing professionals (nurses) and 223 call center operators according cutoff points in the literature (45 and 50) and by means of statistical tests, and verifies the association between NFR scores and the presence of musculoskeletal symptoms. NFR was evaluated with the Need for Recovery Scale and musculoskeletal symptoms were evaluated with the Nordic Musculoskeletal Questionnaire. At a 45 point cutoff, 22% of the call-center workers and 33% of the nurses were classified as fatigued; at a 50 point cutoff, 13% of the call center operators and 27% of the nurses were classified as fatigued. The nurses had higher fatigue levels than the call center workers (p=0.015). Significant correlations were found between NFR scores and musculoskeletal symptoms reported during the previous 12 months (r=0.299, p<0.001) and 7 days (r=0.314, p<0.001). Regarding cutoff points and statistical tests, the NFR scale identified higher fatigue levels among the nurses and was demonstrated to be a useful tool for evaluating worker well-being.

The aim of the present study was to determine the time structure and physiological responses during Songahm Taekwondo (TKD) competition and to compare these variables between winner and non-winner athletes. Fourteen men subjects were analyzed. Blood lactate concentration (LA) and heart rate (HR) were determined before and after the match. The match was filmed for the determination of the number of techniques used, the duration of effort and rest periods (RPs), and the interval between high-intensity movements (HM). Post-match LA was 7.5 +/- 3.8 mmol x L(-1), HR was 183 +/- 9 b.x min(-1), and HM was 31 +/- 16 seconds. The mean effort time (8 +/- 2 seconds) did not differ from mean interval time (8 +/- 3 seconds). Winners used a smaller total number of techniques, but post-match LA or HR did not differ from that of non-winners. In conclusion, the glycolytic metabolism was not the predominant energy source and the physiological responses did not differ between winners and non-winners. Coaches and sports scientists should prepare a technical or physical training session considering the low glycolytic contribution in this sport, hence the training protocol should involve high-intensity movements interspersed with longer RPs to provide the creatine phosphate recovery, with special attention given to the technical quality of TKD skills and not to higher technique volume during a simulation of matches.

Background: Images of myocardial perfusion taken during an episode of chest pain have been used for patients in the emergency department., Objective: To evaluate the operating characteristics of 99mTc-Tetrofosmin scintigraphy during an episode of chest pain to exclude the diagnosis of acute myocardial infarction., Methods: One hundred and eight patients admitted with chest pain, or up to four hours after the end of symptoms and nondiagnostic electrocardiogram, underwent resting scintigraphy and measurement of troponin I concentrations. Patients with a history of myocardial infarction (MI) were not excluded (24 patients). Troponin I concentrations were determined at admission and 6 hours later. Nuclear physicians performed a blind analysis of the images, and myocardial infarction was confirmed whenever troponin I level increase was three times that of the control., Results: Resting perfusion image was abnormal in all 6 patients with MI. Only 1 patient had a normal image and increased troponin levels. Fifty-five patients had positive images without MI, and 46 patients had normal images and troponin levels. The prevalence of the disease was 6.5%. The sensitivity and specificity of the resting images during an episode of chest pain to diagnose MI was 85.7% and 45.5%, respectively. The negative predictive value was 97.7%., Conclusion: Patients undergoing chest pain protocol with SPECT showed an excellent negative predictive value to exclude diagnosis of myocardial infarction. These results suggest that resting perfusion image is an important tool at the chest pain unit.

Objective: We compared the resting energy expenditure (REE) of clinically stable children and adolescents on hemodialysis with that of healthy individuals, to investigate whether the current energy recommendations from the National Kidney Foundation/Kidney Disease Outcomes Initiative (NKF/DOQI) are adequate., Patients and Methods: A cross-sectional study was conducted in 25 children and adolescents (15 male, SD 12.3 +/- 3.1 years old) undergoing hemodialysis (study group) under stable clinical conditions. Patients were pair-matched by sex and age with 25 healthy individuals (control group). The REE was measured by indirect calorimetry. Nutritional status was evaluated by body mass index Z-score, and growth deficit was evaluated by height-for-age Z-score. Body composition was assessed by dual-energy X-ray absorptiometry. The total energy expenditure (TEE) was estimated by multiplying the REE by the physical activity factor. The recommended dietary allowance (RDA) for daily energy intake was compared with the estimated TEE in the study group, considering children's age-specific height., Results: All anthropometric parameters were significantly lower in the study group. Malnutrition and stunting were found in up to 56% and 60%, respectively, of the children in the study group. The absolute REE was significantly lower in the study group than in the control group (1,067 +/- 191 kcal/day vs 1,372 +/- 290 kcal/day, respectively, P < .01). However, when the REE was adjusted for its main determinant, ie, lean body mass, no significant difference was observed between groups (P = .12). In the study group, the RDA for energy was above the TEE in all age groups, and the mean percentage of RDA/TEE was 124.2% +/- 14.2%., Conclusions: Children and adolescents on hemodialysis had an important deficit of energy and protein stores. The similar adjusted REE found between hemodialysis patients and their matched healthy pairs suggests that under stable clinical conditions, the REE of these subjects is normal. Moreover, the energy recommendation set by he NKF/DOQI is appropriate for this population.

The purpose of this study was to evaluate the effect of the resting period on hematological and copper-zinc-dependent antioxidant indices in Brazilian elite judo athletes (n = 7). Venous blood samples were collected after 24-h and 5-d periods of resting following a competition, with an interval of 30 d between collections. Two months prior to and during the study, each athlete received an individualized adequate diet. Body composition was determined at both study periods. The following were analyzed: in whole blood, hemoglobin, hematocrit, red cell count, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red cell distribution width, and white cell count; in plasma, zinc, copper, iron, ceruloplasmin, and total iron-binding capacity; in erythrocytes, metallothionein, copper/zinc superoxide dismutase, and osmotic fragility. Dietary intake and body composition did not affect the biochemical measurements. A significant reduction in ceruloplasmin and superoxide dismutase activity was found after 5 d compared to 24 h of resting. A significant correlation between erythrocyte metallothionein and red cell distribution width was observed after 24 h of resting (r = -0.83, p = 0.02), whereas positive correlations of metallothionein with hemoglobin, red cell count, and mean corpuscular hemoglobin concentration were observed after 5 d of resting (r >/= 0.76, p

Purpose: A cross-sectional study was carried out to characterize the alterations in the resting metabolic rate (RMR), and socioeconomic conditions of 15 stunted (DP= height/age < 95% and 110% (3) weight/height >90%) and 15 nonstunted (EU= height/age > 95% and 110% (3) weight/height >90%) school girls living in shantytowns of São Paulo., Methods: Resting metabolic rate was measured using indirect calorimetry. Socioeconomic data was collected during home visits by administration of a questionnaire., Results: The mildly stunted group had a higher RMR when expressed as Kcal/kg body weight (EU= 40,5 Kcal/kg/day; DP=44,4 Kcal/kg/day; p<0.05) and lean body mass (EU= 49, 2 Kcal/kg/day; DP=52,5 Kcal/kg/day; p<0.05). Stunting was associated with maternal illiteracy (EU= 13,3%; DP=57,1%; p<0.05), income per capita (EU=US$107,14; DP=US$54,40; p< 0.05), number of parasites per child (EU=0; DP=1; p<0.05), birth order (EU=2; DP=4; p< 0.05), and number of siblings (EU=4; DP=6; p<0.01). Stunting was best predicted by income per capita and maternal illiteracy by using multiple logistic regression., Conclusions: Although the two groups had normal weight/height, the group with mild stunting showed socioeconomic and metabolic alterations, typical of a malnourished condition.

Purpose: To evaluate the criteria used for the technique of blood pressure measurement in scientific articles published in Brazilian journals., Methods: Two hundred twenty three scientific articles from 18 medical journals, published between 1989 and 1994 were evaluated, in order to identify the type of sphygmomanometer used; the state of calibration; the cuff size; the position of the patient during the measurement; whether the blood pressure measurement was obtained after a resting period; the phase used to identify the systolic and diastolic pressures; and the number of readings taken., Results: There was no reference in the articles about the following data: the type of sphygmomanometer in 51%, the accuracy of calibration in 82%, the cuff size in 64%, the position of the patient in 25%, the rest period before measurement in 60%, the systolic and diastolic phases in 49%, and the number of measurements in 52%., Conclusion: Most of the papers analyzed did not follow or omitted important aspects cited in national and international recommendations for the correct blood pressure measurement.