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   982246篇
  免费   70636篇
  国内免费   1933篇
耳鼻咽喉   13896篇
儿科学   24925篇
妇产科学   24007篇
基础医学   141965篇
口腔科学   29531篇
临床医学   85034篇
内科学   192782篇
皮肤病学   21033篇
神经病学   75826篇
特种医学   39594篇
外国民族医学   79篇
外科学   158959篇
综合类   18234篇
现状与发展   2篇
一般理论   250篇
预防医学   64135篇
眼科学   22459篇
药学   77279篇
  3篇
中国医学   2776篇
肿瘤学   62046篇
  2021年   7608篇
  2018年   10569篇
  2017年   8216篇
  2016年   9461篇
  2015年   11352篇
  2014年   14963篇
  2013年   20866篇
  2012年   29248篇
  2011年   29712篇
  2010年   17526篇
  2009年   16564篇
  2008年   27862篇
  2007年   28666篇
  2006年   28996篇
  2005年   27671篇
  2004年   26494篇
  2003年   25224篇
  2002年   24511篇
  2001年   55808篇
  2000年   57548篇
  1999年   47662篇
  1998年   11056篇
  1997年   9699篇
  1996年   9776篇
  1995年   9078篇
  1994年   8403篇
  1993年   7710篇
  1992年   35751篇
  1991年   34161篇
  1990年   32955篇
  1989年   32079篇
  1988年   29201篇
  1987年   28450篇
  1986年   26432篇
  1985年   25267篇
  1984年   17919篇
  1983年   15232篇
  1982年   7838篇
  1979年   15849篇
  1978年   10659篇
  1977年   9087篇
  1976年   7911篇
  1975年   8673篇
  1974年   10519篇
  1973年   9900篇
  1972年   9404篇
  1971年   8887篇
  1970年   8473篇
  1969年   7941篇
  1968年   7228篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Quality of Life Research - The COVID-19 pandemic might add to the stressors experienced by people living with rheumatic diseases. This study aimed to examine rheumatic patients’ functional...  相似文献   
3.
Social Psychiatry and Psychiatric Epidemiology - The negative effect of catastrophic financial loss on suicide risk is widely perceived but hardly studied in-depth because of various difficulties...  相似文献   
4.
5.
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   
6.
Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.

Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.

Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings.  相似文献   

7.
Moderate sedatives have been increasingly used to improve patient comfort during flexible bronchoscopy (FB). However, routine use of moderate sedation during FB is controversial because its efficacy and safety are not well established.This study aims to evaluate the efficacy and safety of moderate sedation during FB.A search was made of Medline, EMBASE, and the Cochrane Library to May 2014.Randomized controlled trials (RCTs) and quasi-RCTs were included.The main analysis was designed to examine the efficacy of moderate sedation during FB in sedation than no-sedation.The willingness to repeat FB was significantly more in sedation than no-sedation (odds ratio [OR] 2.30; 95% confidence interval [CI] 1.11–4.73; P = 0.02; I2 = 22.5). The duration of FB was shorter in sedation group than no-sedation group (standardized mean difference [SMD] −0.21; 95% CI −0.38 to −0.03; P = 0.02; I2 = 78.3%). Event of hypoxia was not significantly different between sedation and no-sedation groups (OR 0.86; 95% CI 0.42–1.73; P = 0.67; I2 = 0%). The SpO2 during procedure was not different between sedation and no-sedation groups (SMD −0.14; 95% CI −0.37 to 0.08; P = 0.21; I2 = 49.9%). However, in subgroup analysis without supplemental oxygen, the SpO2 was significantly lower in sedation than no-sedation group (SMD −0.45; 95% CI −0.78 to −0.11; P = 0.01; I2 = 0.0%).According to this meta-analysis, moderate sedation in FB would be useful in patients who will require repeated bronchoscopies as well as safe in respiratory depression. To our knowledge, although the various sedative drugs are already used in the real field, this analysis was the first attempt to quantify objective results. We anticipate more definite and studies designed to elucidate standardized outcomes for moderate sedation in FB.  相似文献   
8.
9.
10.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  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