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   1493985篇
  免费   132130篇
  国内免费   6431篇
耳鼻咽喉   21585篇
儿科学   49065篇
妇产科学   38815篇
基础医学   204343篇
口腔科学   37782篇
临床医学   156890篇
内科学   305047篇
皮肤病学   33683篇
神经病学   127313篇
特种医学   55065篇
外国民族医学   366篇
外科学   225253篇
综合类   29416篇
现状与发展   73篇
一般理论   501篇
预防医学   122427篇
眼科学   32659篇
药学   101542篇
  6篇
中国医学   3192篇
肿瘤学   87523篇
  2021年   14191篇
  2020年   12479篇
  2019年   14048篇
  2018年   23479篇
  2017年   19267篇
  2016年   21099篇
  2015年   23107篇
  2014年   35565篇
  2013年   47189篇
  2012年   51266篇
  2011年   54057篇
  2010年   37620篇
  2009年   38716篇
  2008年   49769篇
  2007年   50749篇
  2006年   53013篇
  2005年   48890篇
  2004年   46109篇
  2003年   42939篇
  2002年   41769篇
  2001年   64579篇
  2000年   65459篇
  1999年   55447篇
  1998年   18142篇
  1997年   16556篇
  1996年   16261篇
  1995年   15519篇
  1994年   13520篇
  1993年   12440篇
  1992年   42897篇
  1991年   42171篇
  1990年   40482篇
  1989年   38468篇
  1988年   35588篇
  1987年   34553篇
  1986年   33051篇
  1985年   31371篇
  1984年   23630篇
  1983年   20142篇
  1982年   12324篇
  1979年   21126篇
  1978年   15158篇
  1977年   12456篇
  1976年   12117篇
  1975年   12397篇
  1974年   15044篇
  1973年   14707篇
  1972年   13653篇
  1971年   12639篇
  1970年   11723篇
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
41.
Maternal and Child Health Journal - Early life exposures can have an impact on a child’s developmental trajectory and children born late preterm (34–36 weeks gestational age)...  相似文献   
42.
43.
44.
Gold nanoparticles (Au NPs) hold great promise in food, industrial and biomedical applications due to their unique physicochemical properties. However, influences of the gastrointestinal tract (GIT), a likely route for Au NPs administration, on the physicochemical properties of Au NPs has been rarely evaluated. Here, we investigated the influence of GIT fluids on the physicochemical properties of Au NPs (5, 50, and 100?nm) and their implications on intestinal epithelial permeability in vitro. Au NPs aggregated in fasted gastric fluids and generated hydroxyl radicals in the presence of H2O2. Cell studies showed that GIT fluids incubation of Au NPs affected the cellular uptake of Au NPs but did not induce cytotoxicity or disturb the intestinal epithelial permeability.  相似文献   
45.
46.
47.
48.

Objectives

To determine: (i) the behaviour change techniques used by a sample of Australian physiotherapists to promote non-treatment physical activity; and (ii) whether those behaviour change techniques are different to the techniques used to encourage adherence to rehabilitation exercises.

Design

Cross-sectional survey.

Method

An online self-report survey was advertised to private practice and outpatient physiotherapists treating patients with musculoskeletal conditions. The use of 50 behaviour change techniques were measured using five-point Likert-type scale questions.

Results

Four-hundred and eighty-six physiotherapists responded to the survey, with 216 surveys fully completed. Most respondents (85.1%) promoted non-treatment physical activity often or all of the time. Respondents frequently used 29 behaviour change techniques to promote non-treatment physical activity or encourage adherence to rehabilitation exercises. A similar number of behaviour change techniques was frequently used to encourage adherence to rehabilitation exercises (n = 28) and promote non-treatment physical activity (n = 26). Half of the behaviour change techniques included in the survey were frequently used for both promoting non-treatment physical activity and encouraging adherence to rehabilitation exercises (n = 25). Graded tasks was the most, and punishment was the least, frequently reported technique used to promote non-treatment physical activity and encourage adherence to rehabilitation exercises.

Conclusions

Respondents reported using similar behaviour change techniques to promote non-treatment physical activity and encourage adherence to rehabilitation exercises. The variability in behaviour change technique use suggests the behaviour the physiotherapist is promoting influences their behaviour change technique choice. Including the frequently-used behaviour change techniques in non-treatment physical activity promotion interventions might improve their efficacy.  相似文献   
49.
G. Berlin  M. Hammar  L. Tapper 《Platelets》2019,30(4):473-479
Platelets are needed to prevent or arrest bleeding and aggregate at the site of injury upon vascular damage. Platelets express receptors for estrogens which might affect the function of the platelets and their hemostatic ability. The aim was to identify possible differences in platelet function related to age, gender, and phases of the menstrual cycle by use of impedance aggregometry with Multiplate. In the first part of the study, platelet function was assessed in 60 healthy individuals (30 men and 30 women) in each of three age groups (20–25, 40–45, and 60–65 years). In the second part of the study, the platelet function was analyzed on four occasions during the menstrual cycle in women without oral contraceptives (OCs) (n = 17) and compared to 19 women on OCs and 18 men of similar age (20–40 years). For the women on OCs, aggregation was analyzed once during the tablet-free week and once late during the period with OCs. The men were sampled once. Women of younger age (<45 years) had significantly higher agonist-induced aggregation response than both men and post-menopausal women (60–65 years). The agonist-induced aggregation response did not differ between phases of the menstrual cycle or OC use. The results suggest that estradiol and/or progesterone affect spontaneous aggregation since it was found to be lowest in the mid-luteal phase. Spontaneous aggregation was significantly lower in women on OCs than in both men and women without OCs. Our findings indicate that fertile age is associated with higher aggregation response capacity of the platelets, possibly to prevent excessive bleeding during menstruation, but this response capacity is not altered during the menstrual cycle or by use of OCs.  相似文献   
50.
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