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   1404602篇
  免费   115985篇
  国内免费   3782篇
耳鼻咽喉   18372篇
儿科学   46510篇
妇产科学   41070篇
基础医学   199566篇
口腔科学   37704篇
临床医学   125843篇
内科学   282542篇
皮肤病学   33387篇
神经病学   116272篇
特种医学   53991篇
外国民族医学   474篇
外科学   210402篇
综合类   33708篇
现状与发展   5篇
一般理论   487篇
预防医学   109421篇
眼科学   31512篇
药学   98747篇
  3篇
中国医学   3557篇
肿瘤学   80796篇
  2021年   10199篇
  2019年   11833篇
  2018年   16741篇
  2017年   12820篇
  2016年   14405篇
  2015年   16238篇
  2014年   22851篇
  2013年   33605篇
  2012年   45779篇
  2011年   48302篇
  2010年   28399篇
  2009年   27228篇
  2008年   44565篇
  2007年   47061篇
  2006年   47663篇
  2005年   46093篇
  2004年   43942篇
  2003年   41841篇
  2002年   40268篇
  2001年   73027篇
  2000年   74482篇
  1999年   61281篇
  1998年   16095篇
  1997年   14447篇
  1996年   14592篇
  1995年   14744篇
  1994年   13385篇
  1993年   12543篇
  1992年   45816篇
  1991年   43507篇
  1990年   41486篇
  1989年   39550篇
  1988年   36156篇
  1987年   35343篇
  1986年   32843篇
  1985年   31265篇
  1984年   23784篇
  1983年   19969篇
  1982年   12163篇
  1981年   10727篇
  1979年   20658篇
  1978年   14546篇
  1977年   12034篇
  1976年   11313篇
  1975年   11583篇
  1974年   13965篇
  1973年   13512篇
  1972年   12622篇
  1971年   11459篇
  1970年   10894篇
排序方式: 共有10000条查询结果,搜索用时 656 毫秒
1.
Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia.  相似文献   
2.
3.
Pancreatic cancer (PC) is a cancer of the digestive system, and pancreatic ductal adenocarcinoma (PDAC) accounts for approximately 90% of all PC cases. Exosomes derived from PDAC (PDAC-exosomes) promote PDAC development and metastasis. Exosomes are nanoscale vesicles secreted by most cells, which can carry biologically active molecules and mediate communication and cargo transportation among cells. Recent studies have focused on transforming exosomes into good drug delivery systems (DDSs) to improve the clinical treatment of PDAC. This review considers PDAC as the main research object to introduce the role of PDAC-exosomes in PDAC development and metastasis. This review focuses on the following two themes: (a) the great potential of PDAC-exosomes as new diagnostic markers for PDAC, and (b) the transformation of exosomes into potential DDSs.  相似文献   
4.
5.
6.
7.
Journal of Molecular Medicine - Chronic exposure to high levels of particulate matter (PM) is correlated to a higher prevalence of cardio-metabolic disturbances. Adipose tissue represents a pivotal...  相似文献   
8.
9.
10.
Postbariatric loss of muscle tissue could negatively affect long-term health due to its role in various bodily processes, such as metabolism and functional capacity. This meta-analysis aimed to unravel time-dependent changes in the magnitude and progress of lean body mass (LBM), fat-free mass (FFM), and skeletal muscle mass (SMM) loss following bariatric surgery. A systematic literature search was conducted in Pubmed, Embase, and Web of Science. Fifty-nine studies assessed LBM (n = 37), FFM (n = 20), or SMM (n = 3) preoperatively and ≥1 time points postsurgery. Random-effects meta-analyses were performed to determine pooled loss per outcome parameter and follow-up time point. At 12-month postsurgery, pooled LBM loss was ?8.13 kg [95%CI ?9.01; ?7.26]. FFM loss and SMM loss were ?8.23 kg [95%CI ?10.74; ?5.73] and ?3.18 kg [95%CI ?5.64; ?0.71], respectively. About 55% of 12-month LBM loss occurred within 3-month postsurgery, followed by a more gradual decrease up to 12 months. Similar patterns were seen for FFM and SMM. In conclusion, >8 kg of LBM and FFM loss was observed within 1-year postsurgery. LBM, FFM, and SMM were predominantly lost within 3-month postsurgery, highlighting that interventions to mitigate such losses should be implemented perioperatively.  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