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   45715篇
  免费   5214篇
  国内免费   111篇
耳鼻咽喉   332篇
儿科学   1389篇
妇产科学   913篇
基础医学   6279篇
口腔科学   1258篇
临床医学   5712篇
内科学   9124篇
皮肤病学   720篇
神经病学   3625篇
特种医学   1993篇
外国民族医学   1篇
外科学   5991篇
综合类   1250篇
一般理论   26篇
预防医学   5309篇
眼科学   851篇
药学   3804篇
中国医学   80篇
肿瘤学   2383篇
  2021年   606篇
  2020年   376篇
  2019年   649篇
  2018年   748篇
  2017年   561篇
  2016年   630篇
  2015年   731篇
  2014年   997篇
  2013年   1427篇
  2012年   2008篇
  2011年   2011篇
  2010年   1174篇
  2009年   1154篇
  2008年   1921篇
  2007年   2056篇
  2006年   1991篇
  2005年   1896篇
  2004年   1751篇
  2003年   1661篇
  2002年   1622篇
  2001年   1563篇
  2000年   1479篇
  1999年   1475篇
  1998年   656篇
  1997年   519篇
  1996年   521篇
  1995年   525篇
  1994年   464篇
  1993年   507篇
  1992年   1216篇
  1991年   1129篇
  1990年   1087篇
  1989年   1059篇
  1988年   991篇
  1987年   975篇
  1986年   993篇
  1985年   911篇
  1984年   779篇
  1983年   645篇
  1982年   432篇
  1981年   352篇
  1979年   590篇
  1978年   490篇
  1977年   374篇
  1976年   392篇
  1974年   432篇
  1973年   400篇
  1972年   386篇
  1971年   349篇
  1969年   359篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
102.
Between 1 January and 31 March 1986, 2434 strains of Haemophilus influenzae collected from 23 laboratories in the United Kingdom were examined. With the same criteria as previous studies in 1977 and 1981 the prevalence of resistance was: ampicillin 7.8% (6.2% beta-lactamase producers and 1.6% non-producers), tetracycline 2.7%, chloramphenicol 1.7%, trimethoprim 4.2%, and sulphamethoxazole 3.5%. of the 87 capsulated strains, 15 produced beta-lactamase, nine were resistant to ampicillin but did not produce beta-lactamase, and two strains, one of which produced beta-lactamase, were resistant to chloramphenicol and tetracycline. Since 1977 the prevalence of resistance to ampicillin, chloramphenicol, and trimethoprim has increased significantly. During 1981-6 strains resistant to ampicillin but not producing beta-lactamase and strains resistant to trimethoprim have significantly increased.  相似文献   
103.
104.
105.
The first case report of systemic evenomation by the five-ringed brown snake, Pseudonaja modesta, is presented. The patient had mild general symptoms of envenomation only, with no coagulopathy or evidence of paralysis. Data on P. modesta venom is presented, which shows an absence of a coagulant component in this venom. The venom gives a positive reaction to brown snake venom in the CSL Venom Detection Kit.  相似文献   
106.
107.
外科医生和手术室人员经常接触手术设备产生的烟气,病人也会暴露于烟气中,特别是腹腔镜手术中产生的烟气滞留于腹腔内这一密闭空间并被吸收.这些烟气是一种与香烟烟气相似的毒性物质,然而对这种毒性物质的影响还未引起足够重视.应该采取必要措施尽可能减少手术中烟气的不良影响.  相似文献   
108.
109.
OBJECTIVE: To describe the dieting histories of bariatric surgery candidates. RESEARCH METHODS AND PROCEDURES: One hundred seventy-seven individuals with extreme obesity who sought bariatric surgery completed the Weight and Lifestyle Inventory, a self-report instrument that assesses several variables, including weight and dieting history. Patients' dieting histories were further explored with an aided recall during a preoperative behavioral/psychological evaluation performed by a mental health professional. RESULTS: Participants who completed the Weight and Lifestyle Inventory reported an average of 4.7 +/- 2.9 successful dieting attempts, defined as those that resulted in a loss of 10 lbs (4.5 kg) or more. These individuals reported a mean total lifetime weight loss of 61.1 +/- 41.3 kg. Despite these efforts, their weight increased from 89.4 +/- 27.4 kg at the time of their first diet (age 21.2 +/- 10.1 years) to 144.5 +/- 30.8 kg at the time they underwent their behavioral/psychological evaluation (age 43.0 +/- 11.0 years). Results of the aided recall revealed that participants had made numerous other efforts to lose weight that were unsuccessful. Self-directed diets and commercial programs were used more frequently. DISCUSSION: Individuals who sought bariatric surgery reported an extensive history of dieting, beginning in adolescence, that was not successful in halting progressive weight gain. Thus, the recommendation often made by insurance companies that patients delay surgery to attempt more conservative treatment options may be unwarranted, particularly in the presence of significant obesity-related comorbidities. Weight loss histories should be routinely examined during a behavioral evaluation to determine whether additional attempts at non-surgical weight loss are advisable. Future studies also are needed to explore the potential relationship between dieting history and postoperative outcome.  相似文献   
110.
The spread of the human immunodeficiency virus through the IV-drug-using population poses a serious public health threat. The tendency is to consider one IV drug user much the same as another. However, there are likely subtle differences in the behaviors of IV drug users depending on sexual, ethnic, and age differences. This study looks at the IV-drug-using behaviors of young adults 18 to 25 and adults over the age of 40. The drugs injected and rates of injection do differ for the two groups. This would suggest that HIV prevention should be tailored in response to the age differences of the targeted drug users.  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