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   1426867篇
  免费   97314篇
  国内免费   1580篇
耳鼻咽喉   17414篇
儿科学   47339篇
妇产科学   37875篇
基础医学   204824篇
口腔科学   36260篇
临床医学   129206篇
内科学   276534篇
皮肤病学   27897篇
神经病学   117110篇
特种医学   55184篇
外国民族医学   265篇
外科学   205956篇
综合类   28029篇
现状与发展   3篇
一般理论   568篇
预防医学   121261篇
眼科学   30692篇
药学   101425篇
  6篇
中国医学   2651篇
肿瘤学   85262篇
  2018年   34070篇
  2017年   26663篇
  2016年   29661篇
  2015年   13909篇
  2014年   18755篇
  2013年   28181篇
  2012年   44170篇
  2011年   59715篇
  2010年   40572篇
  2009年   33112篇
  2008年   56047篇
  2007年   60689篇
  2006年   40472篇
  2005年   41105篇
  2004年   40737篇
  2003年   40118篇
  2002年   37223篇
  2001年   56280篇
  2000年   57419篇
  1999年   48242篇
  1998年   13583篇
  1997年   12425篇
  1996年   12720篇
  1995年   12016篇
  1994年   11195篇
  1993年   10451篇
  1992年   38224篇
  1991年   37751篇
  1990年   36559篇
  1989年   35332篇
  1988年   32733篇
  1987年   32057篇
  1986年   30545篇
  1985年   28816篇
  1984年   21963篇
  1983年   19211篇
  1982年   11391篇
  1981年   10326篇
  1979年   20952篇
  1978年   15407篇
  1977年   12796篇
  1976年   11853篇
  1975年   12818篇
  1974年   15605篇
  1973年   15364篇
  1972年   14513篇
  1971年   13555篇
  1970年   12803篇
  1969年   12084篇
  1968年   11247篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Twenty two patients (age range: 1 month to 11 years) were treated for congenital diaphragmatic defects (excluding hiatus hernia) in the six year period 1983-8. Presenting features were failure to thrive (n = 7), abdominal pain and vomiting (n = 4), chronic respiratory symptoms (n = 3), and inability to wean from ventilatory support (n = 3). The defect was an incidental finding in five patients. Operative repair was performed with no mortality or serious postoperative morbidity. Dramatic improvement occurred in 15 of the 17 symptomatic patients. Awareness of the differential diagnosis should avoid delay in diagnosis or inappropriate treatment. Surgical correction is strongly recommended in all cases.  相似文献   
993.
994.
Five cases of unilateral vocal cord paralysis/paresis were diagnosed following extracorporeal membrane oxygenation for newborn respiratory failure. All were right sided and transient in nature. None of the five patients had other findings commonly associated with vocal cord palsy. The extracorporeal membrane oxygenation procedure requires surgical dissection in the carotid sheath on the right side of the neck, an area immediately adjacent to both the vagus and recurrent laryngeal nerve. It is speculated that vocal cord paralysis in these infants was acquired as a result of the extracorporeal membrane oxygenation cannulation. Although the vocal cord paralysis resolved in all cases, two patients had difficult courses after extracorporeal membrane oxygenation. Therefore, laryngoscopic examination should be considered for patients after extracorporeal membrane oxygenation.  相似文献   
995.
996.
997.
Usher syndrome: clinical findings and gene localization studies   总被引:3,自引:0,他引:3  
The issue of genetic heterogeneity is a critical problem in the localization of the gene(s) for Usher syndrome. Based on the data obtained on families studied to date, the differences between type I and type II Usher syndrome appear quite distinct with regard to auditory and vestibular function. Although the majority of families can be confidently diagnosed as typical type I or type II, clinical investigations revealed four families with findings that did not fit into either of the two more common subtypes. These findings emphasize the critical importance of an in-depth clinical analysis concomitant with the linkage investigation to assure accurate subtyping of Usher syndrome. Based on an analysis of only those families with definite type I or type II Usher syndrome, approximately 17% of the genome can be excluded as a potential site of the gene for type I, and 14% can be excluded as the site for the type II gene. This study will continue until the Usher gene(s) is successfully localized.  相似文献   
998.
This paper reports the results of an experimental study modeled after a study conducted by Kaplan et al. The hypothesis tested was: Adolescents who receive a social learning intervention (SLI) will show greater improvement in metabolic control of their diabetes than will adolescents who receive only traditional diabetes instruction. Thirty-four adolescents between the ages of 12 and 16 who attended a midwestern camp were randomly divided into two groups. Both groups attended a daily 1-hour teaching session about diabetes. Later each day, the experimental group received an SLI consisting of role modeling to help the subjects circumvent peer pressure. To determine metabolic control, HbA1 values were determined before and 3 1/2 months after the intervention. The control group showed no significant difference in HbA1 values, while the experimental group showed a decrease in metabolic control.  相似文献   
999.
D R Holmes  R E Vlietstra 《JAMA》1989,261(14):2109-2115
Percutaneous transluminal coronary angioplasty has grown exponentially since its introduction. Currently, selection criteria include single-vessel and multivessel disease, stable and unstable angina, and acute infarction. The outcome depends on specific patient and angiographic characteristics. In ideal lesions, success rates should be greater than 90%, with low morbidity and mortality. With more severe and diffuse multivessel disease, success rates are lower and complication rates are higher. In these cases, percutaneous transluminal coronary angioplasty still offers a reasonable option, provided complete revascularization can be achieved or the angina-producing lesion dilated. Numerous issues remain unresolved, including (1) the role of percutaneous transluminal coronary angioplasty vs coronary surgery (currently being tested), (2) restenosis, which occurs in approximately 30% of treated lesions, and (3) organizational adjustments such as training and certification to maintain high standards of care.  相似文献   
1000.
Dietary factors in the risk of bladder cancer   总被引:2,自引:0,他引:2  
The relationship between selected dietary factors and the risk of bladder cancer was investigated in a case-control study conducted in northern Italy. The study included 163 cases and 181 controls who were hospitalized for acute, nonneoplastic or urinary tract diseases. The frequency of consumption of green vegetables and carrots was lower in the cases; thus, the estimated relative risks for the upper vs. the lower tertiles were 0.6 for green vegetables and 0.5 for carrots. Significant inverse trends in risk emerged with estimated carotenoid (as well as retinoid) intake. The apparent protection conveyed by vitamin A was stronger in current smokers. The risk of bladder cancer was not related to scores of fat and measures of alcohol consumption; the risk was elevated in coffee drinkers (although there was no tendency to rise with higher consumption), but it was reduced in tea drinkers. These findings were not explainable in terms of selection, information, or confounding bias. Thus, although available information is too uncertain for any precise definition of specific (micro)nutrients related to bladder cancer risk, the confirmation that several aspects of a less-affluent diet adversely affect the risk is still of interest in terms of a better understanding of bladder carcinogenesis.  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