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31.
Ratios for major organ weights compared with bodyweights of 1023 stillborn and liveborn babies who lived less than 72 h are presented. The ratios were calculated for 2 week increments of gestational age from 20 to 43 weeks and clearly depict the relative growth of fetal organs during the last half of pregnancy. The ratios for heart and for kidneys were virtually constant for the whole period of gestation examined. The ratios for thymus and spleen increased between 20 and 30 weeks gestation and then became constant, although the ratio for the spleen dropped slightly during the last 6 weeks. The ratios for liver, lungs and adrenals decreased between 20 and 30 weeks gestation, and then steadied. The ratio for brain declined very slowly throughout the period examined. An observation of practical importance was that all organ weight/bodyweight ratios were virtually constant after 30 weeks gestation. Approximate mean organ weight/bodyweight ratios between 30 and 43 weeks gestation were: heart 0.007, lungs 0.02, spleen 0.003, liver 0.04, kidneys 0.01, adrenals 0.003, thymus 0.004 and brain 0.13. By multiplying the mean ratio by the total bodyweight, the approximate mean weight for a particular fetal organ can be calculated in situations where charts of normal organ weights are not at hand.  相似文献   
32.
温度和体重对蚂蟥人工繁殖影响的研究   总被引:4,自引:4,他引:4  
史红专  刘飞  郭巧生 《中国中药杂志》2006,31(24):2030-2032
目的:确定蚂蟥的最佳产卵温度、体重以及孵化的最适温度。方法:在不同温度、体重条件下观察蚂蟥产卵和孵化。结果与结论:蚂蟥产卵和孵化的最适温度是25 ℃,产卵的最佳体重为20 g左右;温度能影响蚂蟥产卵前后的体重,而体重对其的影响不明显;当卵重在0.1~2.0 g时与孵出量成正比,当卵重大于2.0 g时孵出量反而有所下降。  相似文献   
33.

Objectives

We wanted to verify if the “learning to learn” effect observed in the learning of visuomotor tasks is also present when learning a balance task, i.e., whether the learning rate of a balance task is improved by prior practice of similar balance tasks.

Design

Single centre, parallel group, controlled training study.

Methods

32 young healthy participants were divided into a control and a training group. The training group’s practice consisted of 90 trials of three balance tasks. Forty-eight hours after the training, we recorded performance during the acquisition (90 trials) of a novel balance task in both groups, and 24 h thereafter we measured its retention (10 trials).

Results

Mixed models statistical analysis showed that the learning rate of both the acquisition and the retention phase was not influenced by the 90 prior practice trials performed by the training group. However, participants with high lower limb power had a higher balance performance than participants with low power, which can be partly explained by the higher learning rate observed during the acquisition phase for participants with high power.

Conclusions

Contrary to visuomotor or perceptual tasks, we did not find a “learning to learn” effect for balance tasks. The correlation between learning rate and lower limb power suggests that motor learning of dynamic balance tasks may depend on the physical capability to execute the correct movement. Thus, a prior strength and conditioning program with emphasis on lower limb power should be considered when designing a balance training, especially in fall prevention.  相似文献   
34.
Snacking, or the habit of eating little and often, has been postulated to have a range of health benefits in relation to appetite control, bodyweight management and improved blood glucose control in diabetics and pre‐diabetics. However, there is widespread agreement that our current obesogenic environment is encouraging overeating in response to increased food portion sizes, palatability and/or energy‐density of foods, alongside the many social and psychological cues to eat. In this context, and as findings on the health effects of snacking are conflicting, the question remains as to whether more frequent eating and snacking can be of benefit to health. Snacks, if added to habitual meal intake, with no compensation for snack energy contribution, are likely over time to lead to positive energy balance. Hence, snacking might be a contributing factor to the obesity epidemic, in addition to more established factors, such as food choice and physical activity. This paper explores the existing evidence concerning the impact of snacking on bodyweight and the behavioural and metabolic response to snacking. The impact of snacking on cognitive function is also discussed. The review highlights the need for further research as, despite many years of scientific interest in snacking, the lack of consistency in study design and snacking definitions and the array of potential confounding factors (e.g. physical activity levels) makes interpretation of findings difficult and has led to little consensus about the optimum number and composition of meals and/or snacks for bodyweight control, health and wellbeing on a population‐wide basis.  相似文献   
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Clinical features associated with improvement of fatty liver disease   总被引:1,自引:0,他引:1  
BACKGROUND: We presumed that identification of the factors associated with improvement of fatty livers disease (FLD) would support the therapeutic options for FLD. The goal of this study was to clarify what clinical characteristics are associated with biochemical and sonographic improvements in the non-alcoholic population with fatty livers. METHODS: A total of 615 non-alcoholic men had elevated alanine aminotransferase (ALT) (> or = 40 IU/L) levels and sonographic evidence of a fatty liver, and their clinical characteristics were assessed at the beginning of the study and after 1 year of follow up. The improvement was defined as combination of normal ALT level and negative sonography for hepatic fat after 1 year. Programmed intervention or medications were not applied in this study population. RESULTS: The overall rate of improvement of FLD after a 1-year follow up was 37/615 (6.0%). The improvement was strongly associated with decrement of changes in bodyweight, body mass index, waist circumference, gamma-glutamyltransferase, fasting blood sugar, total cholesterol, triglycerides, low-density lipoprotein cholesterol, total cholesterol/high-density lipoprotein cholesterol ratio and homeostasis model assessment. Multivariate analysis showed that decrement of changes in bodyweight (odds ratio (OR) = 1.56; 95% confidence interval (95%CI): 1.27-1.92) per 1 kg, body mass index (OR = 2.42; 95%CI: 1.58-3.71) per 1 SD (0.8 kg/m2), waist circumference (OR = 2.13; 95%CI: 1.02-4.54) per 1 cm, and low-density lipoprotein cholesterol (OR = 1.64; 95%CI: 1.05-2.56) per 1 SD (22 mg/dL) were all independent predictors for improvement of FLD. CONCLUSIONS: These results suggest that the reduction of bodyweight is a major key point for the improvement of FLD.  相似文献   
38.
1. Inbreeding and optimization of environmental conditions for laboratory rats may have led to the survival of mutants with metabolic aberrations but without evident disease phenotype. Therefore, in the present study, we compared metabolic traits between so-called disease-resistant inbred rat strains Dark Agouti (DA), Brown Norway (BN), Lewis (LEW), Wistar-Kyoto (WKY), Fischer 344 (F344) and wild rats (Rattus norvegicus). 2. Twelve males of each strain at 12, 13 and 14 weeks of age were studied for bodyweight, body mass index (BMI), blood glucose, serum triglycerides, total cholesterol, insulin and leptin. 3. In comparison with wild rats, the cholesterol values were significantly increased in all inbred rats studied. Except for DA rats, all rats were also significantly heavier than wild rats. 4. There were also significant differences between the different disease-resistant strains and WKY rats were the biggest animals with the highest bodyweight, BMI and cholesterol values. 5. The strains could be separated into groups with either very high (F344, LEW, WKY) or low values (DA, BN) of serum insulin and leptin levels. 6. Because all rats were studied under the same conditions, the findings suggest a substantial strain dependence in feeding behaviour and energy balance caused by the different genotypes.  相似文献   
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40.
Home-based resistance exercise (RE) has become increasingly prevalent, but its effects on protein metabolism are understudied. We tested the effect of an essential amino acid formulation (EAA+: 9 g EAAs, 3 g leucine) and branched-chain amino acids (BCAAs: 6 g BCAAs, 3 g leucine), relative to a carbohydrate (CHO) placebo, on exogenous leucine retention and myofibrillar protein breakdown following dynamic bodyweight RE in a home-based setting. Twelve recreationally active adults (nine male, three female) participated in a double-blind, placebo-controlled, crossover study with four trial conditions: (i) RE and EAA+ (EX-EAA+); (ii) RE and BCAAs (EX-BCAA); (iii) RE and CHO placebo (EX-CHO); and (iv) rest and CHO placebo (REST-CHO). Total exogenous leucine oxidation and retention (estimates of whole-body anabolism) and urinary 3-methylhistidine:creatinine ratio (3MH:Cr; estimate of muscle catabolism) were assessed over 5 h post-supplement. Total exogenous leucine oxidation and retention in EX-EAA+ and EX-BCAA did not significantly differ (p = 0.116) but were greater than EX-CHO (p < 0.01). There was a main effect of condition on urinary 3MH:Cr (p = 0.034), with post hoc analysis revealing a trend (p = 0.096) for reduced urinary 3MH:Cr with EX-EAA+ (32%) compared to EX-CHO. By direct comparison, urinary 3MH:Cr was significantly lower (23%) in EX-EAA+ than EX-BCAA (p = 0.026). In summary, the ingestion of EAA+ or BCAA provided leucine that was ~60% retained for protein synthesis following home-based bodyweight RE, but EAA+ most effectively attenuated myofibrillar protein breakdown.  相似文献   
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