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   6449篇
  免费   567篇
  国内免费   33篇
耳鼻咽喉   24篇
儿科学   246篇
妇产科学   106篇
基础医学   980篇
口腔科学   77篇
临床医学   697篇
内科学   1540篇
皮肤病学   226篇
神经病学   528篇
特种医学   557篇
外科学   570篇
综合类   100篇
一般理论   2篇
预防医学   649篇
眼科学   57篇
药学   372篇
中国医学   6篇
肿瘤学   312篇
  2021年   69篇
  2020年   63篇
  2019年   70篇
  2018年   104篇
  2017年   80篇
  2016年   116篇
  2015年   123篇
  2014年   142篇
  2013年   228篇
  2012年   324篇
  2011年   343篇
  2010年   210篇
  2009年   178篇
  2008年   296篇
  2007年   262篇
  2006年   260篇
  2005年   242篇
  2004年   246篇
  2003年   213篇
  2002年   231篇
  2001年   204篇
  2000年   165篇
  1999年   181篇
  1998年   211篇
  1997年   154篇
  1996年   171篇
  1995年   142篇
  1994年   118篇
  1993年   114篇
  1992年   111篇
  1991年   95篇
  1990年   87篇
  1989年   150篇
  1988年   117篇
  1987年   119篇
  1986年   110篇
  1985年   103篇
  1984年   66篇
  1983年   71篇
  1982年   57篇
  1981年   39篇
  1980年   51篇
  1979年   59篇
  1978年   42篇
  1977年   44篇
  1976年   50篇
  1975年   48篇
  1973年   35篇
  1972年   31篇
  1971年   39篇
排序方式: 共有7049条查询结果,搜索用时 15 毫秒
1.
2.
The bulk of research into drug driving in Australia has been undertaken from a road safety orientation where drug driving is viewed within the broader context of road safety and driver behaviour. Such a specific focus precludes the broader behavioural, contextual and cultural issues associated with substance use. This study aimed to address this issue by focusing on drug driving behaviour within the context of illicit substance use. A series of focused interviews were conducted with 211 illicit drug users from urban and regional centres. A consistent theme identified in the interviews was that drug driving was not necessarily viewed as risky behaviour but rather as an outcome of illicit substance use. Further, some interviewees saw their drug use as enhancing their driving skills and frequently the motor vehicle was viewed as a safe place to use. Overall there was agreement among interviewees that the likelihood of being apprehended for drug driving by police was minimal; this perception was reinforced by past experience. The lack of concern for detection of drug driving behaviour suggests that research should continue into the development and implementation of enforcement programs and roadside detection.  相似文献   
3.
BACKGROUND: Our aims in the present study were to estimate the influences of pain and urinary symptoms on quality of life, and to determine which of these two variables has the most predictive power with respect to quality of life in young men with chronic prostatitis-like symptoms. METHODS: Chronic prostatitis-like symptoms were measured by the National Institutes of Health-Chronic Prostatitis Symptom Index. Of the 28,841 men aged 20 years who lived in the study community, 18,495 men (a response rate 64.1%) agreed to participate in the study. A total of 1057 men who complained of symptoms indicative of chronic prostatitis were included in the study. The influences of pain and urinary symptoms on quality of life were determined using logistic regression analysis. The receiver operating characteristic (ROC) curve was used to estimate the predictive ability of each of these variables with respect to quality of life. RESULTS: Results from multivariate analysis showed that both pain and urinary symptoms were associated with an increased likelihood of impaired quality of life, although pain contributed more to a reduced quality of life than urinary symptoms. Relative to men who experienced mild pain, men who experienced moderate pain had a 3.9-fold risk of poor quality of life (odds ratio [OR], 3.87; 95% confidence interval [CI], 2.86-5.23; P < 0.001) and those who experienced severe pain had a 15.7-fold risk of reduced quality of life (OR, 15.68; 95% CI, 6.59-37.35; P < 0.001). Moderate urinary symptoms were associated with a 1.4-fold risk of bother (OR, 1.41; 95% CI, 1.01-1.99; P < 0.001) and severe urinary symptoms were associated with 2.4-fold risk (OR, 2.39; 95% CI, 1.37-4.12; P < 0.001), relative to mild urinary symptoms. Comparison of the effects of pain and urinary symptoms showed that pain severity had the most predictive power for bother, quality of life, and quality-of-life impact. The areas under the ROC curves for bother, quality of life, and quality-of-life impact were 71.3%, 69.3% and 72.5%, respectively. CONCLUSION: Urinary symptoms and pain might be associated with an increased likelihood of impaired quality of life in young men with chronic prostatitis-like symptoms. In addition, our findings suggest that pain severity is the most influential variable for determining quality of life in this population.  相似文献   
4.
Fifty patients with suspected intra-abdominal abscess were investigated prospectively with ultrasound and with 99mTc-hexamethylpropylene-amine oxime (HMPAO) isotope labelled mixed leucocytes, using 111-In tropolonate granulocyte scanning as the reference standard. Twenty five patients had inflammatory bowel disease (three were postoperative): 21 of these had Crohn's disease and four had ulcerative colitis. The remainder comprised nine with postoperative fever and 16 with fever and abdominal pain. An abscess was diagnosed when focal activity on serial 111-In tropolonate and 99m-Tc-HMPOA images at one, three, and 24 hours resulted in activity at least equal to liver activity at 24 hours. Thirteen abscesses were diagnosed using each type of white cell scanning, resulting in 100% sensitivity for 99m-Tc-HMPAO compared with 111-In tropolonate. Bowel inflammation was easily distinguished from abscess on serial images. Eight of these 13 abscesses were detected by ultrasound. Altogether 17 abscesses were found. Ultrasound detected 12, including four liver abscesses which were not purulent and had not been detected by white cell scanning. Ultrasound had a sensitivity of 71% (12 of 17) and a specificity of 87% (33 of 38) using all confirmed abscesses as the reference standard. White cell scanning showed a sensitivity of 76% (13 of 17: as a result of the four non-purulent liver abscesses) and a specificity of 100%. 99m-Tc-HMPAO scanning is as accurate as 111-In tropolonate scanning, and has several advantages including simplicity, availability, superior image quality, and reduced radiation dose. Both methods are more sensitive and specific than ultrasound for intra-abdominal abscess detection but ultrasound is advisable if a neutrophil infiltrate is not suspected.  相似文献   
5.
6.
Summary: A number of new antiepileptic drugs (AEDs), including topiramate (TPM), felbamate (FBM), and gabapentin (GBP), are approved or believed to be close to approval for marketing in the United States. Key efficacy findings for these AEDs in refractory partial epilepsy were reviewed. Large and significant drug-placebo differences were observed with TPM in two large dose-finding trials conducted in the United States. The minimal effective dose of TPM in the population studied was determined to be approximately 200 mg/day, and doses above 600 mg/day produced good efficacy but little incremental benefit versus the lower dosages for the overall study population. FBM is active in partial epilepsy, although seizure reduction is less marked and drug interactions complicate the findings. GBP is also active in this population, but only the 1,800 mg/day dosage was significantly better than placebo with respect to percent re-sponders. It may be useful to explore higher dosage ranges for both FBM and GBP if they can be well tolerated.  相似文献   
7.
8.
Evaluation of an on-line patient exposure meter in neuroradiology   总被引:1,自引:0,他引:1  
  相似文献   
9.
Pediatric knee MR imaging: pattern of injuries in the immature skeleton   总被引:3,自引:0,他引:3  
  相似文献   
10.
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