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   15693篇
  免费   1256篇
  国内免费   36篇
耳鼻咽喉   187篇
儿科学   528篇
妇产科学   373篇
基础医学   2471篇
口腔科学   397篇
临床医学   1687篇
内科学   3268篇
皮肤病学   300篇
神经病学   1170篇
特种医学   488篇
外国民族医学   1篇
外科学   2069篇
综合类   103篇
一般理论   10篇
预防医学   1321篇
眼科学   337篇
药学   1215篇
中国医学   33篇
肿瘤学   1027篇
  2023年   88篇
  2022年   125篇
  2021年   256篇
  2020年   209篇
  2019年   278篇
  2018年   295篇
  2017年   307篇
  2016年   338篇
  2015年   318篇
  2014年   446篇
  2013年   639篇
  2012年   831篇
  2011年   760篇
  2010年   456篇
  2009年   419篇
  2008年   655篇
  2007年   684篇
  2006年   638篇
  2005年   617篇
  2004年   681篇
  2003年   554篇
  2002年   539篇
  2001年   430篇
  2000年   465篇
  1999年   415篇
  1998年   201篇
  1997年   146篇
  1996年   166篇
  1995年   158篇
  1994年   144篇
  1993年   141篇
  1992年   311篇
  1991年   336篇
  1990年   333篇
  1989年   343篇
  1988年   269篇
  1987年   277篇
  1986年   239篇
  1985年   292篇
  1984年   193篇
  1983年   164篇
  1982年   129篇
  1981年   106篇
  1980年   91篇
  1979年   173篇
  1978年   126篇
  1977年   107篇
  1975年   98篇
  1974年   117篇
  1973年   105篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
Clinical versus ultrasonographic evaluation of scrotal disorders   总被引:1,自引:0,他引:1  
Clinical and ultrasonographic examinations of scrotal disorders were compared in 166 patients in order to determine their ability to distinguish between those diseases requiring surgery and those requiring clinical follow-up only. Ultrasound examinations were efficient in discriminating between normal and pathological findings. Extra-testicular lesions were readily differentiated from testicular ones. Although both clinical and ultrasonographic examinations had high sensitivity (90%) in detecting testicular cancer, the number of false positive findings was smaller after ultrasound examination. This gave a predictive value of a positive test of 53% after ultrasound examination but only 33% after clinical examination. Ultrasound examination may, therefore, reduce the number of surgical explorations in the scrotum and should be performed in patients with suspected testicular pathology based on history and palpatory findings.  相似文献   
3.
4.
5.
This study estimated the effects of changing multiple levels and combinations of nutrition information format, load, expression, and order on consumers' perceptions of label usefulness in purchase decisions using adaptive conjoint analysis. A shopping mall intercept survey, which was administered by a marketing research firm, assessed consumer preferences for 12 label alternatives produced on Campbell's soup cans to portray nutrition information realistically; 252 of 258 respondents completed the computer interactive interview. Consumers significantly preferred the bar graph format to the bar graph/nutrient density and traditional label formats. Consumers considered the bar graph/nutrient density format to be as useful as the traditional label format. There was a highly significant difference among the three levels of information load; the most information load was preferred regardless of nutrient importance. Consumers significantly preferred nutrition information stated in absolute numbers and percentages vs in absolute numbers only in traditional, or in percentages only expressions. There was a significant difference between consumer preferences for the two types of information order. The findings indicate that consumers clearly preferred the nutrition label that displayed all nutrient values using a bar graph format, offered the most information load, and expressed nutrient values using both absolute numbers and percentages. Consumers also preferred nutrition information rearranged in an order that grouped nutrients that should be consumed in adequate amounts on the top, calories in the middle, and nutrients that should be consumed in lesser amounts on the bottom of the label.  相似文献   
6.
7.
The Monk Duopleet femoral interlocking uncemented two-component endoprosthesis consists of a polyethylene cup covered by a metal cap and an Austin-Moore type stem. Seventy-two patients (average age, 71 years) were treated by this arthroplasty: 27 for subcapital femoral neck fracture, 36 for osteoarthritis, and nine as an exchange operation. Three patients died following operation. After a mean follow-up time of 50 months, 47 patients were reexamined clinically and radiographically. Because of loosening, four patients had the prosthesis removed. Twenty-six patients were classified as excellent, 12 as good, six as fair, and three as poor. There were no cases of acetabular intrusion. The Monk Duopleet prosthesis may solve the problem of the loosening that had been associated with femoral component alone. The long-term results are promising and appear to be better than the results of the standard Moore prosthesis. The Monk Duopleet prosthesis is an alternative to other two-component endoprostheses for the treatment of subcapital hip fractures and in the group of patients suffering from osteoarthritis, where an arthroplasty with a cemented prosthesis may be considered hazardous because of age or general disease.  相似文献   
8.
9.

Background  

Sleep problems are common effects of shift work. The aim of the present study was to evaluate how different types of shift affect sleep and sleepiness, and to relate sleepiness to urinary 6-sulfatoxymelatonin.  相似文献   
10.
OBJECTIVE: Based on recent safety and efficacy data, combined with the known pharmacokinetic parameters of aminoglycosides in the newborn, once-daily gentamicin should be preferable to the many other dosing regimens currently in use. Although there are growing data to support its use in term newborns, experience with preterm infants is more limited. In our Neonatal Intensive Care Unit, we experienced difficulties regarding complicated dosing regimens, actual dosing errors, and the tendency to check trough and peak levels around the third dose for infants receiving only a 48 hour course. Therefore, we conducted a quality improvement initiative in which we developed and tested a clinical practice guideline for the use of once-daily gentamicin for preterm and term infants that we hoped would yield trough and peak levels in our target range. METHODS: We combined a review of the published English language literature with pharmacokinetic analysis of our own data prior to initiation of this new regimen to design the following dosing regimen: <35 weeks gestation: 3 mg/kg q 24 hours, > or =35 weeks gestation: 4 mg/kg q 24 hours. Our goal serum levels were a trough < or =2 microg/ml and a peak between 6 and 12 microg/ml. We collected and analyzed trough and peak levels from all infants receiving this dosing regimen in the first week of life for at least 72 hours between 3/1/99 and 12/31/00. RESULTS: In total, 214 babies met our inclusion criteria, 75 of whom were <35 weeks gestation. 100% of babies of all gestational ages had a nontoxic trough level. For infants <35 weeks gestation, 79% had a therapeutic peak level, with a mean value of 6.8 microg/ml. For infants of at least 35 weeks gestation, 93% had a therapeutic peak level, with a mean value of 8.4 microg/ml. 92% of nontherapeutic peaks were too low. CONCLUSION: This study of once-daily gentamicin represents the largest sample size of pre-term infants published to date. The proposed regimen is simple and yields a high proportion of desirable levels. We recommend it for use in preterm and term newborns.  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