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   17542篇
  免费   1607篇
  国内免费   38篇
耳鼻咽喉   196篇
儿科学   577篇
妇产科学   430篇
基础医学   2574篇
口腔科学   450篇
临床医学   2016篇
内科学   3112篇
皮肤病学   349篇
神经病学   1495篇
特种医学   573篇
外科学   2088篇
综合类   293篇
一般理论   14篇
预防医学   1835篇
眼科学   351篇
药学   1113篇
中国医学   47篇
肿瘤学   1674篇
  2022年   130篇
  2021年   337篇
  2020年   246篇
  2019年   315篇
  2018年   334篇
  2017年   266篇
  2016年   324篇
  2015年   342篇
  2014年   488篇
  2013年   748篇
  2012年   1034篇
  2011年   1034篇
  2010年   606篇
  2009年   577篇
  2008年   909篇
  2007年   974篇
  2006年   901篇
  2005年   853篇
  2004年   878篇
  2003年   832篇
  2002年   753篇
  2001年   355篇
  2000年   357篇
  1999年   347篇
  1998年   210篇
  1997年   194篇
  1996年   145篇
  1995年   154篇
  1994年   138篇
  1993年   150篇
  1992年   309篇
  1991年   278篇
  1990年   242篇
  1989年   248篇
  1988年   182篇
  1987年   211篇
  1986年   199篇
  1985年   233篇
  1984年   158篇
  1983年   147篇
  1982年   122篇
  1981年   108篇
  1979年   142篇
  1978年   104篇
  1977年   100篇
  1976年   103篇
  1974年   97篇
  1973年   111篇
  1972年   111篇
  1971年   103篇
排序方式: 共有10000条查询结果,搜索用时 453 毫秒
11.
12.
13.
OBJECTIVE: To survey nurses around the world about current practices for peritoneal dialysis (PD) home training programs. DESIGN: Random sampling of nurses to complete a written survey from the International Society for Peritoneal Dialysis Nursing Liaison Committee. Settings: United States, Canada, South America (Brazil, Columbia), The Netherlands, Hong Kong. METHODS: Surveys and responses were sent by fax whenever possible, or by regular mail, or hand carried, or conducted by telephone. Results were stratified by geographic areas as well as by cumulative responses and were expressed as medians with ranges. Kruskal-Wallis was used to evaluate differences in responses. Associations between variables were tested with Pearson correlation. Univariate regression analysis was used to evaluate the impact of variables on peritonitis rates. Variables with p < 0.10 were included in a multivariate analysis. RESULTS: A total of 317 nurses responded: 88 in the United States, 46 in Canada, 58 in South America, 58 in Hong Kong, and 67 in The Netherlands. This represented 37% of all surveys distributed. Respondents had a median of 12 years' experience in nephrology (range 1-35 years), but only 31% had a formal background in adult education. Nearly half received their guidance to patient training from a nurse colleague, 11% were guided by a corporate colleague, and 8% were simply self-taught. Clinics responding had a median of 30 PD patients (range 1-400) and reported they trained a median of 8 patients per year (range 0-86). Reported peritonitis rates were a median 0.46 per year or 1 episode every 26 months. Peritonitis rates, however, were not known by 53% of respondents. Total training time per patient had a very wide range of hours, from 6 to 96. There was no correlation between training time and peritonitis rates among the study respondents (p = 0.38), nor with any other variables. CONCLUSIONS: There is wide variation in practices for PD patient training programs within countries and around the world. Training time did not appear to be related to peritonitis rates. Randomized trials of training practices are needed to determine which approaches produce the best outcomes for patients.  相似文献   
14.
15.
Objective. The safety and efficacy of intrathecal (IT) ziconotide was studied in a randomized, double‐blind, placebo‐controlled trial. Materials and Methods. Patients (169 ziconotide, 86 placebo) with severe chronic nonmalignant pain unresponsive to conventional therapy and a visual analog scale of pain intensity (VASPI score) ≥ 50 mm were treated over a 6‐day period in an inpatient hospital setting. Initial starting dose was 0.4 µg/hour and was titrated to analgesia or intolerance (maximum dose 7.0 µg/hour). The starting and maximum doses were reduced to 0.1 µg/hour and 2.4 µg/hour, respectively, due to adverse events (AEs). Results. The mean percent reduction in VASPI score from baseline was 31.2% and 6.0% for ziconotide‐ and placebo‐treated patients, respectively (p ≤ 0.001). During the initial titration phase, a significantly greater percentage of patients in the ziconotide group compared to the placebo group reported AEs, including abnormal gait, amblyopia, dizziness, nausea, nystagmus, pain, urinary retention, and vomiting. Conclusion. Ziconotide provided significant analgesia in patients for whom conventional therapy failed. However, there was a considerable incidence of ziconotide‐associated AEs due to the rapid titration and high doses administered.  相似文献   
16.
17.
18.
19.
PURPOSE: A role for estrogens in determining lung cancer risk and prognosis is suggested by reported sex differences in susceptibility and survival. Archival lung tissue was evaluated for the presence of nuclear estrogen receptor (ER)-alpha and ER-beta and the relationship between ER status, subject characteristics, and survival. EXPERIMENTAL DESIGN: Paraffin-embedded lung tumor samples were obtained from 214 women and 64 men from two population-based, case-control studies as were 10 normal lung autopsy samples from patients without cancer. Nuclear ER-alpha and ER-beta expression was determined by immunohistochemistry. Logistic regression was used to identify factors associated with ER positivity and Cox proportional hazards models were used to measure survival differences by ER status. RESULTS: Neither tumor (0 of 94) nor normal (0 of 10) lung tissue stained positive for ER-alpha. Nuclear ER-beta positivity was present in 61% of tumor tissue samples (170 of 278; 70.3% in men and 58.3% in women) and 20% of normal tissue samples (2 of 10; P = 0.01). In multivariate analyses, females were 46% less likely to have ER-beta-positive tumors than males (odds ratio, 0.54; 95% confidence interval, 0.27-1.08). This relationship was stronger and statistically significant in adenocarcinomas (odds ratio, 0.40; 95% confidence interval, 0.18-0.89). Women with ER-beta-positive tumors had a nonsignificant 73% (P = 0.1) increase in mortality, whereas men with ER-beta-positive tumors had a significant 55% (P = 0.04) reduction in mortality compared with those with ER-beta-negative tumors. CONCLUSIONS: This study suggests differential expression by sex and influence on survival in men of nuclear ER-beta in lung cancer, particularly in adenocarcinomas.  相似文献   
20.
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