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   1291篇
  免费   185篇
  国内免费   2篇
耳鼻咽喉   7篇
儿科学   23篇
妇产科学   60篇
基础医学   218篇
口腔科学   22篇
临床医学   354篇
内科学   278篇
皮肤病学   17篇
神经病学   48篇
特种医学   53篇
外科学   157篇
综合类   5篇
预防医学   95篇
眼科学   12篇
药学   42篇
中国医学   1篇
肿瘤学   86篇
  2023年   27篇
  2022年   20篇
  2021年   36篇
  2020年   29篇
  2019年   14篇
  2018年   49篇
  2017年   52篇
  2016年   52篇
  2015年   50篇
  2014年   58篇
  2013年   43篇
  2012年   52篇
  2011年   41篇
  2010年   40篇
  2009年   55篇
  2008年   35篇
  2007年   46篇
  2006年   53篇
  2005年   29篇
  2004年   44篇
  2003年   38篇
  2002年   34篇
  2001年   27篇
  2000年   26篇
  1999年   21篇
  1998年   21篇
  1997年   21篇
  1996年   19篇
  1994年   9篇
  1992年   22篇
  1991年   26篇
  1990年   28篇
  1989年   29篇
  1988年   25篇
  1987年   46篇
  1986年   32篇
  1985年   27篇
  1984年   18篇
  1983年   9篇
  1979年   17篇
  1978年   12篇
  1977年   8篇
  1976年   9篇
  1975年   12篇
  1974年   9篇
  1973年   12篇
  1972年   12篇
  1971年   11篇
  1969年   8篇
  1968年   10篇
排序方式: 共有1478条查询结果,搜索用时 15 毫秒
171.
172.
The level of uric acid (UA) was studied in the blood of healthy persons and CHD patients. A total of 428 males aged 40 to 59 were examined. The level of blood UA in CHD patients was much higher than in healthy persons of the same age. The frequency of hyperuricemia among CHD patients was 31%, in the control groups 10-15%. There was a direct correlation of UA levels with concentrations of triglycerides and total blood cholesterol. In CHD patients with atherogenic dyslipoproteinemia the UA concentration was higher than in patients without lipid metabolic derangements. The importance of a raised UA level in CHD development was discussed.  相似文献   
173.
174.
175.
The purpose of this study was to evaluate the self‐determined motivation predictors of exercise behaviour following pulmonary rehabilitation in COPD recipients. This cross‐sectional study was conducted with 135 COPD patients. A demographic questionnaire, clinical factors, behavioural regulations in exercise questionnaire, and leisure time exercise questionnaire were used to collect data. A logistic regression model was used to identify the predictors associated with demographics and self‐determined motivation types regarding physical activity. Education level, episodes of acute exacerbation within 2 years, and identified regulation were significant predictors of executing physical activities with high metabolic equivalents. The results of this study imply that healthcare providers need to be aware of the importance of exercise motivation among COPD patients.  相似文献   
176.
OBJECTIVES: In the European Project on Genes in Hypertension (EPOGH) standardized epidemiological methods were used to determine complex phenotypes consisting of blood pressure (BP) in combination with other traits. In this report, we present the quality control of one of the BP phenotypes. METHODS: In seven European countries eight different research groups recruited random samples of nuclear families. Trained observers measured the BP five times consecutively with the participants in the seated position at each of two separate home visits, 1 to 3 weeks apart, according to the guidelines of the British Hypertension Society. Quality assurance and quality control of this BP phenotype were implemented according to detailed instructions defined in the protocol of the EPOGH study. RESULTS: On 31 August 2001, BP measurements of 2476 subjects were available for analysis. Fewer BP readings than the five planned per visit occurred in one of the eight centres, but only in 0.4% of the home visits. Across centres the relative frequency of identical consecutive readings for systolic or diastolic blood pressure varied from 0 to 6%. The occurrence of odd readings ranged from 0 to 0.1%. Of the 49,488 systolic and diastolic BP readings, 24.0% ended on a zero (expected 20%). In most EPOGH centres there was a progressive decline in the BP from the first to the second home visit. Overall, these decreases averaged 2.36 mmHg [95% confidence interval (CI): 1.98-2.74, P < 0.001] for systolic BP and 1.74 mmHg (95% CI: 1.46-2.02, P < 0.001) for diastolic BP. CONCLUSIONS: Quality assurance and control should be planned at the design stage of a project involving BP measurement and implemented from its very beginnings until the end. The procedures of quality assurance set up in the EPOGH study for the BP measurements resulted in a well-defined BP phenotype, which was consistent across centres.  相似文献   
177.
Fessas  P; Anagnou  NP; Loukopoulos  D 《Blood》1980,55(4):564-569
L-alpha-Glycerol-3-phosphate dehydrogenase (EC 1.1.1.8) has been reported to be absent in the erythrocytes of normal adults, but can be found in those of cord blood and of thalassemia major. The aid of this study was to investigate whether there is any relation between GDH and gamma-chain synthesis. Erythrocyte GDH activity was determined on 118 different blood samples. It was undetectable in normal adult erythrocytes and definitely high in cord blood cells (23.6 UI/10(11) RBC). Considerable GDH activity was also noted in patients with thalassemia major (11.0 IU10(11) RBC) as well as in cases with pronounced reticulocytosis (11.4 IU/10(11) RBC). Red cells from beta- thalassemia heterozygotes exhibited moderate but distinct GDH activity (5.2 IU/10(11) RBC). After fractionation into young and old erythrocyte populations, clearly higher GDH activity was found in the younger cells; however, there was no significant correlation with the reticulocyte count. Presence of reticulocytes alone appears insufficient to explain the values obtained in cord blood and the thalassemias, especially heterozygous. Furthermore, no direct correlation between GDH and fetal hemoglobin (HbF) was obtained in cord and thalassemic erythrocytes.  相似文献   
178.
179.
180.
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