887 resultados para interval regular
Resumo:
The hypothesis that prepulse inhibition of the blink reflex reflects a transient process that protects preattentive processing of the prepulse was investigated. Participants were presented with pairs of blink-eliciting noises, with some noises preceded by a prepulse, and were asked to rate the intensity of the second noise relative to the first. Inhibition of blink amplitude was greater for a 110 dB(A) noise than for a 95 dB(A) noise with a 120 ms lead interval, whereas there was no difference with a 30 ms lead interval. The reduction in perceived intensity was greater for the 110 dB(A) noise than for the 95 dB(A) noise with the 120 ms lead interval, but not with the 30 ms lead interval. The parallel results support an association between prepulse inhibition and perceived intensity. However, the prepulse did not reduce intensity ratings relative to control trials in some conditions, suggesting that prepulse inhibition is not always associated with an attenuation of the impact of the blink-eliciting stimulus.
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Exercise training has an important role in the prevention and treatment of hypertension, but its effects on the early metabolic and hemodynamic abnormalities observed in normotensive offspring of hypertensive parents (FH+) have not been studied. We compared high-intensity interval (aerobic interval training, AIT) and moderate-intensity continuous exercise training (CMT) with regard to hemodynamic, metabolic and hormonal variables in FH+ subjects. Forty-four healthy FH+ women (25.0+/-4.4 years) randomized to control (ConFH+) or to a three times per week equal-volume AIT (80-90% of VO(2MAX)) or CMT (50-60% of VO(2MAX)) regimen, and 15 healthy women with normotensive parents (ConFH-; 25.3+/-3.1 years) had their hemodynamic, metabolic and hormonal variables analyzed at baseline and after 16 weeks of follow-up. Ambulatorial blood pressure (ABP), glucose and cholesterol levels were similar among all groups, but the FH+ groups showed higher insulin, insulin sensitivity, carotid-femoral pulse wave velocity (PWV), norepinephrine and endothelin-1 (ET-1) levels and lower nitrite/ nitrate (NOx) levels than ConFH- subjects. AIT and CMT were equally effective in improving ABP (P<0.05), insulin and insulin sensitivity (P<0.001); however, AIT was superior in improving cardiorespiratory fitness (15 vs. 8%; P<0.05), PWV (P<0.01), and BP, norepinephrine, ET-1 and NOx response to exercise (P<0.05). Exercise intensity was an important factor in improving cardiorespiratory fitness and reversing hemodynamic, metabolic and hormonal alterations involved in the pathophysiology of hypertension. These findings may have important implications for the exercise training programs used for the prevention of inherited hypertensive disorder. Hypertension Research (2010) 33, 836-843; doi:10.1038/hr.2010.72; published online 7 May 2010
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Exercise is an effective intervention for treating hypertension and arterial stiffness, but little is known about which exercise modality is the most effective in reducing arterial stiffness and blood pressure in hypertensive subjects. Our purpose was to evaluate the effect of continuous vs. interval exercise training on arterial stiffness and blood pressure in hypertensive patients. Sixty-five patients with hypertension were randomized to 16 weeks of continuous exercise training (n=26), interval training (n=26) or a sedentary routine (n=13). The training was conducted in two 40-min sessions a week. Assessment of arterial stiffness by carotid-femoral pulse wave velocity (PWV) measurement and 24-h ambulatory blood pressure monitoring (ABPM) were performed before and after the 16 weeks of training. At the end of the study, ABPM blood pressure had declined significantly only in the subjects with higher basal values and was independent of training modality. PWV had declined significantly only after interval training from 9.44 +/- 0.91 to 8.90 +/- 0.96 m s(-1), P=0.009 (continuous from 10.15 +/- 1.66 to 9.98 +/- 1.81 m s(-1), P-ns; control from 10.23 +/- 1.82 to 10.53 +/- 1.97 m s(-1), P-ns). Continuous and interval exercise training were beneficial for blood pressure control, but only interval training reduced arterial stiffness in treated hypertensive subjects. Hypertension Research (2010) 33, 627-632; doi:10.1038/hr.2010.42; published online 9 April 2010
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Background: Despite antihypertensive therapy, it is difficult to maintain optimal systemic blood pressure (BP) values in hypertensive patients (HPT). Exercise may reduce BP in untreated HPT. However, evidence regarding its effect in long-term antihypertensive therapy is lacking. Our purpose was to evaluate the acute effects of 40-minute continuous (CE) or interval exercise (IE) using cycle ergometers on BP in long-term treated HPT. Methods: Fifty-two treated HPT were randomized to CE (n=26) or IE (n=26) protocols. CE was performed at 60% of reserve heart rate (HR). IE alternated consecutively 2 min at 50% reserve HR with 1 min at 80%. Two 24-h ambulatory BP monitoring were made after exercise (postexercise) or a nonexercise control period (control) in random order. Results: CE reduced mean 24-h systolic (S) BP (2.6 +/- 6.6 mm Hg, p-0.05) and diastolic (D) BP (2.3 +/- 4.6, p-0.01), and nighttime SBP (4.8 +/- 6.4, p < 0.001) and DBP (4.6 +/- 5.2 mm Hg, p-0.001). IE reduced 24-h SBP (2.8 +/- 6.5, p-0.03) and nighttime SBP (3.4 +/- 7.2, p-0.02), and tended to reduce nighttime DBP (p=0.06). Greater reductions occurred in higher BP levels. Percentage of normal ambulatory BP values increased after CE (24-h: 42% to 54%; daytime: 42% to 61%; nighttime: 61% to 69%) and IE (24-h: 31% to 46%; daytime: 54% to 61%; nighttime: 46% to 69%). Conclusion: CE and IE reduced ambulatory BP in treated HPT, increasing the number of patients reaching normal ambulatory BP values. These effects suggest that continuous and interval aerobic exercise may have a role in BP management in treated HPT. (c) 2008 Elsevier Ireland Ltd. All rights reserved.
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This study examined group and individual factors that facilitate changes in cooperation and learning outcomes in trained and untrained work groups of elementary school-age children. The study had two foci. The first was to determine if the cooperative behaviors and interactions of children in classroom groups who were trained in cooperative learning skins were different from those of children who were given no training, and the second was to investigate small group interactions and achievement in these groups over time. The results showed that there were observable differences between student interactions in the two conditions and these differences were maintained over time. Compared with children in the untrained groups, those in the trained groups were consistently more cooperative and helpful to each other; they actively tried to involve each other in the learning task by using language which was more inclusive (e.g., frequent use of ''we''), and they gave more explanations to assist each other as they worked together. It appeared that as the children worked together over time, they became more responsive to the learning needs of each other. Furthermore, the children in the trained groups performed significantly better on the learning outcomes questionnaire than those in the untrained groups. (C) 1997 Society for the Study of School Psychology. Published by Elsevier Science Ltd.
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Background: The optimal interval between neoadjuvant chemoradiation therapy (CRT) and surgery in the treatment of patients with distal rectal cancer is controversial. The purpose of this study is to evaluate whether this interval has an impact on survival. Methods and Materials: Patients who underwent surgery after CRT were retrospectively reviewed. Patients with a sustained complete clinical response (cCR) 1 year after CRT were excluded from this study. Clinical and pathologic characteristics and overall and disease-free survival were compared between patients undergoing surgery 12 weeks or less from CRT and patients undergoing surgery longer than 12 weeks from CRT completion and between patients with a surgery delay caused by a suspected cCR and those with a delay for other reasons. Results: Two hundred fifty patients underwent surgery, and 48.4% had CRT-to-surgery intervals of 12 weeks or less. There were no statistical differences in overall survival (86% vs. 81.6%) or disease-free survival rates (56.5% and 58.9%) between patients according to interval (<= 12 vs. >1 2 weeks). Patients with intervals of 12 weeks or less had significantly higher rates of Stage III disease (34% vs. 20%; p = 0.009). The delay in surgery was caused by a suspected cCR in 23 patients (interval, 48 +/- 10.3 weeks). Five-year overall and disease-free survival rates for this subset were 84.9% and 51.6%, not significantly different compared with the remaining group (84%; p = 0.96 and 57.8 %; p = 0.76, respectively). Conclusions: Delay in surgery for the evaluation of tumor response after neoadjuvant CRT is safe and does not negatively affect survival. These results support the hypothesis that shorter intervals may interrupt ongoing tumor necrosis. (C) 2008 Elsevier Inc.
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Deminice, R, Sicchieri, T, Mialich, MS, Milani, F, Ovidio, PP, and Jordao, AA. Oxidative stress biomarker responses to an acute session of hypertrophy-resistance traditional interval training and circuit training. J Strength Cond Res 25(3): 798-804, 2011-We have studied circuit resistance schemes with high loads as a time-effective alternative to hypertrophy-traditional resistance training. However, the oxidative stress biomarker responses to high-load circuit training are unknown. The aim of the present study was to compare oxidative stress biomarker response with an acute session of hypertrophy-resistance circuit training and traditional interval training. A week after the 1 repetition maximum (1RM) test, 11 healthy and well-trained male participants completed hypertrophy-resistance acute sessions of traditional interval training (3 x 10 repetitions at 75% of the 1RM, with 90-second passive rest) and circuit training (3 x 10 repetitions at 75% of the 1RM, in alternating performance of 2 exercises with different muscle groups) in a randomized and cross-over design. Venous blood samples were collected before (pre) and 10 minutes after (post) the resistance training sessions for oxidative stress biomarker assays. As expected, the time used to complete the circuit training (20.2 +/- 1.6) was half of that needed to complete the traditional interval training (40.3 +/- 1.8). Significant increases (p < 0.05) in thiobarbituric acid reactive substances (40%), creatine kinase (CK) (67%), glutathione (14%), and uric acid (25%) were detected posttraditional interval training session in relation to pre. In relation to circuit training, a significant increase in CK (33%) activity postsession in relation to pre was observed. Statistical analysis did not reveal any other change in the oxidative stress biomarker after circuit training. In conclusion, circuit resistance-hypertrophy training scheme proposed in the current study promoted lower oxidative stress biomarkers and antioxidant modulations compared with resistance traditional interval training.
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Previous studies have indicated that the use of low-fluoride dentifrices could lead to proportionally higher plaque fluoride levels when compared with conventional dentifrices. This double-blind, randomized, crossover study determined the effects of placebo, low-fluoride, and conventional dentifrices on plaque fluoride concentrations ([F]) in children living in communities with 0.04, 0.72, and 3.36 ppm F in the drinking water. Children used the toothpastes twice daily, for 1 wk. Samples were collected 1 and 12 hrs after the last use of dentifrices and were analyzed for fluoride and calcium. Similar increases were found 1 hr after the children brushed with low-fluoride (ca. 1.9 mmol F/kg) and conventional (ca. 2.4 mmol F/kg) dentifrices in the 0.04- and 0.72-ppm-F communities. Despite the fact that the increases were less pronounced in the 3.36-ppm-F community, our results indicate that the use of a low-fluoride dentifrice promotes a proportionally higher increase in plaque [F] when compared with that achieved with a conventional dentifrice, based on dose-response considerations.
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Objective: This in situ/ex vivo study assessed the erosive potential of a light cola drink when compared to a regular one. Methods: During 2 experimental 14-days crossover phases, eight volunteers wore palatal devices with 2 human enamel blocks. The groups under study were: group light, erosive challenge with light cola drink and group regular, erosive challenge with regular cola drink. During 14 days, erosive challenges were performed extraorally 3X/day. In each challenge, the device was immersed in 150 ml of light cola (group light) or regular cola (group regular) for 5 min. Erosion was analysed by surface profilometry (mu m) and surface microhardness change (%SMH). The data were statistically analyzed using paired t test (p<0.05). Results: Group light (0.6 +/- 0.2 mu m) showed significantly lesser wear than group regular (3.1 +/- 1.0 mu m). There was no significant difference between the groups for the %SMH (group light -63.9 +/- 13.9 and group regular -78.5 +/- 12.7). Conclusions: The data suggest that the light cola drink is less erosive than the regular one. (C) 2008 Elsevier Ltd. All rights reserved.
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Objective: To evaluate whether the type of cola drink (regular or diet) could influence the wear of enamel subjected to erosion followed by brushing abrasion, Method and !Materials: Ten volunteers wore intraoral devices that each had eight bovine enamel blocks divided into four groups; ER, erosion with regular cola; EAR, erosion with regular cola plus abrasion; EL, erosion with light cola; and EAL, erosion with light cola plus abrasion, Each day for 1 week, half of each device was immersed in regular cola for 5 minutes, Then, two blocks were brushed using a fluoridated toothpaste and electric toothbrush for 30 seconds four times daily, Immediately after, the other half of the device was subjected to the same procedure using a light cola, The pH, calcium, phosphorus, and fluoride concentrations of the colas were analyzed using standard procedures, Enamel alterations were measured by profilometry. Data were tested using two-way ANOVA and Bonferroni test (P < .05), Results: Regarding chemical characteristics, light cola presented pH 3.0, 13.7 mg Ca/L, 15.5 mg P/L, and 0.31 mg F/L, while regular cola had pH 2.6, 32.1 mg Ca/L, 1:8.1 mg P/L, and 0.26 mg F/L, The light cola promoted less enamel loss (EL, 0.36 pm; EAL, 0.39 pm) than its regular counterpart (ER, 0.72 pm; EAR, 0.95 pm) for both conditions, There was not a significant difference (P > .05) between erosion and erosion plus abrasion for light cola, However, for regular cola, erosion plus abrasion resulted in higher enamel loss than erosion alone,.nclusion: The data suggest that light cola promoted less enamel wear even when erosion was followed by brushing abrasion, (Quintessence Int 2011;42:xxx-xx)()