首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   763篇
  免费   185篇
  国内免费   40篇
  2024年   12篇
  2023年   45篇
  2022年   53篇
  2021年   60篇
  2020年   39篇
  2019年   45篇
  2018年   37篇
  2017年   44篇
  2016年   34篇
  2015年   51篇
  2014年   52篇
  2013年   83篇
  2012年   38篇
  2011年   36篇
  2010年   24篇
  2009年   27篇
  2008年   28篇
  2007年   18篇
  2006年   24篇
  2005年   15篇
  2004年   19篇
  2003年   19篇
  2002年   13篇
  2001年   13篇
  2000年   10篇
  1999年   19篇
  1998年   13篇
  1997年   10篇
  1996年   3篇
  1995年   12篇
  1994年   10篇
  1993年   5篇
  1992年   22篇
  1991年   9篇
  1990年   8篇
  1989年   10篇
  1988年   9篇
  1987年   5篇
  1986年   4篇
  1985年   2篇
  1984年   4篇
  1982年   1篇
  1981年   1篇
  1976年   1篇
  1974年   1篇
排序方式: 共有988条查询结果,搜索用时 24 毫秒
81.
Morningness-eveningness, time of day, and physical exercises have been shown to influence mood states. This study aimed to test whether impact of physical exercise on mood depends on time of day and chronotype. Ninety-four participants (age 32 ± 6 years; 34% females; weekly training volume 4 ± 1 hours) filled the Composite Scale of Morningness and reported their current mood using the UWIST Mood Adjective Checklist before and after a 60-min long CrossFit training session which took part in the morning (beginning at 6:30 or 7:45) or in the evening (beginning at 19:30 or 20:45). In this quasi-experiment the measurements were taken by the occasion of the participants’ usual training, in their preferred hours. There were only a few evening-types in the studied sample, while morning and intermediate chronotypes were over-represented. Participation in CrossFit training resulted in mood improvement consisting of increase in energetic arousal (η2 = 0.29) and hedonic tone (η2 = 0.47) and reduction of tense arousal (η2 = 0.14), all significant at p = 0.001. Furthermore, CrossFit training during morning hours boosted mood in the intermediate/evening chronotype group to the levels observed in morning chronotypes (η2 = 0.29, p < 0.05, for the three-way interaction effect). We conclude that participation in intense physical exercise, such as CrossFit training, may allow compensation for the negative effects of non-optimal time of day on experienced moods, particularly in the case of neither/evening-types.  相似文献   
82.
Exercise training has been used for treatment/prevention of many cardiovascular diseases, but the mechanisms need to be clarified. Thus, our aim was to compare oxidative stress parameters between rats submitted to a swimming training and sedentary rats (control). Twelve male rats were divided into two groups: control and exercise training. The exercise training had daily 1 h swimming sessions for 8 weeks and a load (5% of its body mass) was placed in rat's tail. Thereafter the animals were killed, aorta and heart were surgically removed and blood was collected. Body mass gain, thiobarbituric acid reactive species (TBARS), carbonyl content, total reactive antioxidant potential (TRAP), total antioxidant reactivity (TAR), superoxide dismutase (SOD) activity and catalase (CAT) activity were evaluted. The trained rats showed a lower body mass gain and no modifications on heart. An increased SOD activity was observed on aorta after the training, but no changes were seen for CAT activity, which led to an increased SOD/CAT ratio. The arterial TBARS was also increased for trained rats. The decrease in TRAP in exercise training was the single modification on plasma. Our findings suggest that the increased SOD activity could play a role in vascular adaptations to exercise training. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
83.
Only few data are available on the effect of training on phospholipid metabolism in skeletal muscles. The aim of the present study was to examine the effect of 6 weeks of endurance training on the content of particular phospholipid fractions and on the incorporation of blood-borne [14C]-palmitic acid into the phospholipids in different skeletal muscles (white and red sections of the gastrocnemius, the soleus and the diaphragm) of the rat. Lipids were extracted from the muscles and separated using thin-layer chromatography into the following fractions: sphingomyelin, phosphatidylcholine, phosphatidylserine, phosphatidylinositol, phosphatidylethanolamine, cardiolipin and neutral lipids (this fraction being composed mostly of triacylglycerols). It was found that training did not affect the content of any phospholipid fraction in soleus muscle. It increased the content of sphingomyelin in white gastrocnemius muscle, cardiolipin and phosphatidylethanolamine in red gastrocnemius muscle and phosphatidylinositol in white gastrocnemius muscle and diaphragm. The total phospholipid content in red gastrocnemius muscle of the trained group was higher than in the control group. Training reduced the specific activity of sphingomyelin and cardiolipin in all muscles, phosphatidylcholine in soleus, red, and white gastrocnemius muscles, phosphatidylserine in all muscles, phosphatidylinositol in all except the soleus muscle, and phosphatidylethanolamine in hindleg muscles, but not in the diaphragm compared to the corresponding values in the sedentary group. It was concluded that endurance training affects skeletal muscle phospholipid content and the rate of incorporation of the blood-borne [14C]palmitic acid into the phospholipid moieties.  相似文献   
84.
This study assessed the effectiveness of operant conditioning in training three species of captive callitrichid primates (Leontopithecus rosalia, Callithrix geoffroyi, and Saguinus imperator) to urinate on demand. There were three goals to the study: 1) to develop a system for quantitatively assessing positive reinforcement training; 2) to ascertain whether or not positive reinforcement techniques can be used to train callitrichid monkeys to urinate on demand, and if so, how many training sessions are required; and 3) to determine the effect on urination behavior of the trainer entering the cage to collect a urine sample. Positive reinforcement with a continuous reinforcement schedule was used to capture a natural behavior: urination. Training sessions (30 min each) were conducted at dawn thrice weekly during five consecutive phases: habituation, control, training (animals were rewarded for urinating), maintenance (animals had reached a defined training criteria and continued to be rewarded for urinating), and collection (animals were rewarded for urinating, and the trainer entered the cage to collect the sample). The numbers of 30-min training sessions required to train the three monkey species (L. rosalia, C. geoffroyi, and S. imperator) were five, six, and eight, respectively. For the three species, the mean number of urinations per animal was significantly greater during the training, maintenance, and collection phases compared to the control phase. However, the three species differed significantly in the manner in which the rates of urination changed across the five phases. A higher proportion of subjects urinated during the training, maintenance, and collection phases compared to the control phase. Latency to first urination varied significantly across the five phases, with significantly reduced latencies to urinate during the training, maintenance, and collection phases compared to the control phase. The entry of the trainer into the cage to collect the urine sample did not appear to alter urination behavior. We demonstrate that operant conditioning techniques, which typically incur minimal cost, time investment, and disturbance, can be used to increase the quantity of urine samples collected for physiological analysis, the proportion of animals that urinate, and the speed of sample collection.  相似文献   
85.
It is not possible to accurately predict the perceptual response to odorants and odorant mixtures without understanding patterns of suppression and facilitation that result from interactions between the olfactory and trigeminal systems. The current study extends previous findings by exploring the effect of intensive training on the interaction between these systems and also by using a different mixed chemosensory stimulus to examine whether the principles established in earlier studies generalize to different odorants. Stimuli were chosen so as to selectively activate the olfactory (H2S) and trigeminal (CO2) nerves. In addition, linalool was included as a stimulus that activated both systems. Thirty-five participants (19 men, 16 women) rated the intensity of each stimulus when presented both alone and in binary mixtures (linalool + H2S, and linalool + CO2). Chemosensory event-related potentials were obtained from three recording positions. Analysis of intensity ratings showed that linalool was significantly less intense than the other stimuli when presented alone. In binary mixtures, H2S was strongly suppressed by linalool. One week of intensive odor training produced significant and specific reductions in the intensity of linalool and H2S, both alone and in their mixture. Training with a different odor (champignol) had no effect. Chemosensory event-related potential data confirmed previous findings showing changes in topographical distribution that reflected the degree of trigeminal activity. Binary mixtures generally produced larger amplitudes than single stimuli. Latencies clearly differentiated between the three single stimuli and the binary mixtures. Changes were observed in event-related potentials that reflected those obtained for intensity ratings in that they were observed for linalool and H2S in the linalool trained group only. The amplitude of the late 'endogenous' component (P3) was significantly decreased for these odors at frontal recording sites. In summary, strong and specific training effects were observed in intensity ratings for participants trained with the test odor (linalool), but not for those trained with a different odor. This was supported by a significant decrease of amplitudes of the event-related potentials at frontal recording sites following training with the test odor only  相似文献   
86.
This pilot study investigated whether group training, in which participants become role models and coaches, would reduce discomfort as compared to a nontreatment Control Group. Sixteen experimental participants participated in 6 weekly 2-hr group sessions of a Healthy Computing program whereas 12 control participants received no training. None of the participants reported symptoms to their supervisors nor were they receiving medical treatment for repetitive strain injury prior to the program. The program included training in ergonomic principles, psychophysiological awareness and control, sEMG practice at the workstation, and coaching coworkers. Using two-tailed t tests to analyze the data, the Experimental Group reported (1) a significant overall reduction in most body symptoms as compared to the Control Group and (2) a significant increase in positive work-style habits, such as taking breaks at the computer, as compared to the Control Group. This study suggests that employees could possibly improve health and work style patterns based on a holistic training program delivered in a group format followed by individual practice.  相似文献   
87.
The modification of posture in children using sEMG is a new area that offers much potential to aid disabled children regain function. This article describes a new protocol, the minimax procedure, to aid children regain motor function in sitting. The protocol uses selective reinforcement to encourage recruiting/relaxing target sites (gluteus medius/maximus) in a predetermined way so as to encourage good form in sitting. Children often are unaware how to make changes in posture, and when they do succeed the progress is so slow that sustaining motivation is a challenge. This paper describes a procedure that helps the child recognize when they have achieved the correct posture, immediately rewards them for doing so, and generates data using Boolean operations to numerically substantiate the clinically observed changes in posture.  相似文献   
88.
89.
Recent neuroscientific evidence has revealed that the adult brain is capable of substantial plastic change in areas such as the primary somatosensory cortex that were formerly thought to be modifiable only during early experience. We discuss research on phantom limb pain as well as chronic back pain that revealed functional reorganization in both the somatosensory and the motor system in these chronic pain states. In phantom limb pain patients, cortical reorganization is correlated with the amount of phantom limb pain; in low back pain patients the amount of reorganizational change increases with chronicity. We present a model of the development of chronic pain that assumes an important role of somatosensory pain memories. In phantom limb pain, we propose that those patients who experienced intense pain prior to the amputation will later likely develop enhanced cortical reorganization and phantom limb pain. We show that cortical plasticity related to chronic pain can be reduced by behavioral interventions that provide feedback to the brain areas that were altered by somatosensory pain memories.  相似文献   
90.
Autogenic training: a meta-analysis of clinical outcome studies   总被引:3,自引:0,他引:3  
Autogenic training (AT) is a self-relaxation procedure by which a psychophysiological determined relaxation response is elicited. A meta-analysis was performed to evaluate the clinical effectiveness of AT. Seventy-three controlled outcome studies were found (published 1952–99). Sixty studies (35 randomized controlled trials [RCT]) qualified for inclusion in the meta-analysis. Medium-to-large effect sizes (ES) occurred for pre–post comparisons of disease-specific AT-effects, with the RCTs showing larger ES. When AT was compared to real control conditions, medium ES were found. Comparisons of AT versus other psychological treatment mostly resulted in no effects or small negative ES. This pattern of results was stable at follow-up. Unspecific AT-effects (i.e., effects on mood, cognitive performance, quality of life, and physiological variables) tended to be even larger than main effects. Separate meta-analyses for different disorders revealed a significant reduction of the heterogeneity of ES. Positive effects (medium range) of AT and of AT versus control in the meta-analysis of at least 3 studies were found for tension headache/migraine, mild-to-moderate essential hypertension, coronary heart disease, asthma bronchiale, somatoform pain disorder (unspecified type), Raynaud's disease, anxiety disorders, mild-to-moderate depression/dysthymia, and functional sleep disorders.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号