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   1385957篇
  免费   99163篇
  国内免费   2240篇
耳鼻咽喉   19888篇
儿科学   45672篇
妇产科学   40253篇
基础医学   202059篇
口腔科学   39540篇
临床医学   115112篇
内科学   278459篇
皮肤病学   30203篇
神经病学   107995篇
特种医学   52485篇
外国民族医学   367篇
外科学   210858篇
综合类   27100篇
现状与发展   1篇
一般理论   336篇
预防医学   103551篇
眼科学   31612篇
药学   105382篇
  1篇
中国医学   3016篇
肿瘤学   73470篇
  2018年   16166篇
  2017年   11481篇
  2016年   12427篇
  2015年   14243篇
  2014年   19030篇
  2013年   28960篇
  2012年   41651篇
  2011年   44664篇
  2010年   25564篇
  2009年   23059篇
  2008年   41873篇
  2007年   45332篇
  2006年   45313篇
  2005年   44489篇
  2004年   42283篇
  2003年   40928篇
  2002年   40161篇
  2001年   61143篇
  2000年   63155篇
  1999年   53301篇
  1998年   14670篇
  1997年   13112篇
  1996年   13350篇
  1995年   12559篇
  1994年   11931篇
  1993年   11027篇
  1992年   42047篇
  1991年   41210篇
  1990年   40665篇
  1989年   39340篇
  1988年   36664篇
  1987年   35881篇
  1986年   34254篇
  1985年   32565篇
  1984年   24235篇
  1983年   21057篇
  1982年   12497篇
  1981年   11038篇
  1979年   22936篇
  1978年   16067篇
  1977年   13911篇
  1976年   13153篇
  1975年   14443篇
  1974年   16956篇
  1973年   16386篇
  1972年   15576篇
  1971年   14510篇
  1970年   13472篇
  1969年   13004篇
  1968年   12224篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
International Journal of Clinical Oncology - Immune-checkpoint inhibitors (ICIs) are standard treatments for metastatic non-small cell lung cancer (NSCLC). Patients with poor performance status...  相似文献   
3.
4.
5.
6.
Journal of Immigrant and Minority Health - COVID-19 has disproportionally affected underrepresented minorities (URM) and low-income immigrants in the United States. The aim of the study is to...  相似文献   
7.
Vaccination is a vital health care initiative to prevent individual and population infection. To increase vaccination rates the federal government implemented the ‘No Jab, No Pay’ policy, where eligibility for several government benefits required children to be fully vaccinated by removing ‘conscientious objections’ and expanding the age range of children whose families receive benefits. This study assesses the impact of this policy at a local area within a single medical practice community in NSW, Australia. A retrospective clinical audit was performed between 2012 and 2017 on a single general practice's vaccination records for children ≤19 years. Catch-up vaccinations were assessed based on age at vaccination. Incidence of catch-up vaccinations was assessed for each of four years before and two years after the implementation of the ‘No Jab, No Pay’ policy in January 2016, along with the age of children and vaccination(s) given. Catch-up vaccinations were assessed temporally either side of implementation of ‘No Jab, No Pay’. Comparing the average annual vaccination catch-up incidence rate of 6.2% pre-implementation (2012–2015), there was an increase to 9.2% in 2016 (p < .001) and 7.8% in 2017 (p = .027). Secondary outcome measurement of catch-up vaccination incidence rates before (2012–2015) and after (2016–2017) ‘No Jab, No Pay’ implementation showed statistically significant increases for children aged 8–11 years (3.2%–5.6%, p = .038), 12–15 years (7.5%–14.7%, p < .001) and 16–19 years (3.3%–10.2%, p < .001) along with a statistically significant reduction in children aged 1–3 years (11.4%–6.2%, p = .015). Also, catch-up rates for DTPa significantly increased after program implementation. This study demonstrates that the Australian federal government vaccination policy ‘No Jab, No Pay’ was coincident with an increase in catch-up vaccinations within a rural NSW community served by one medical practice, especially for older children.  相似文献   
8.
9.
10.
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   
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