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   21677篇
  免费   2491篇
  国内免费   50篇
耳鼻咽喉   208篇
儿科学   788篇
妇产科学   546篇
基础医学   3237篇
口腔科学   585篇
临床医学   2524篇
内科学   3670篇
皮肤病学   350篇
神经病学   1581篇
特种医学   912篇
外国民族医学   3篇
外科学   2836篇
综合类   443篇
一般理论   25篇
预防医学   2586篇
眼科学   377篇
药学   1769篇
中国医学   93篇
肿瘤学   1685篇
  2021年   228篇
  2020年   177篇
  2019年   259篇
  2018年   375篇
  2017年   228篇
  2016年   258篇
  2015年   324篇
  2014年   432篇
  2013年   627篇
  2012年   905篇
  2011年   936篇
  2010年   557篇
  2009年   519篇
  2008年   832篇
  2007年   902篇
  2006年   963篇
  2005年   948篇
  2004年   881篇
  2003年   842篇
  2002年   841篇
  2001年   819篇
  2000年   826篇
  1999年   742篇
  1998年   340篇
  1997年   301篇
  1996年   326篇
  1995年   289篇
  1994年   267篇
  1993年   237篇
  1992年   590篇
  1991年   509篇
  1990年   502篇
  1989年   461篇
  1988年   463篇
  1987年   448篇
  1986年   432篇
  1985年   407篇
  1984年   310篇
  1983年   245篇
  1982年   200篇
  1981年   187篇
  1980年   176篇
  1979年   284篇
  1978年   217篇
  1977年   179篇
  1976年   171篇
  1975年   168篇
  1974年   195篇
  1973年   187篇
  1972年   191篇
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
11.
Thirteen cases of primary appendicular adenocarcinoma are reported. This rare tumour usually presents as acute appendicitis. The correct diagnosis is rarely entertained before or during surgery. The main treatment choice lies between appendicectomy alone and appendicectomy followed by right hemicolectomy. There are anatomical reasons for advising the latter and survival figures from the literature tend to support this preference. The cases reported here indicate that in the period 1972-1984, in the North West Region, there was a slight preference for appendicectomy alone. The additional procedure of right hemicolectomy did not confer any clear-cut survival advantage.  相似文献   
12.
Ten oxacillin-sensitive Staphylococcus aureus strains were grown on agar containing four times their ciprofloxacin MIC to determine if exposure to ciprofloxacin would increase their resistance to oxacillin. All strains grew on the ciprofloxacin-containing agar and subsequently grew on oxacillin-salt agar. The geometric mean MICs for oxacillin increased one- to sixteen-fold and remained elevated after ten passages on antibiotic-free agar. The mecA gene was not detected in any strain. There was no increase in oxacillin MICs when the bacteria were passaged on agar containing four times their MIC of piperacillin/tazobactam. Exposure of oxacillin-sensitive strains of Staphylococcus aureus to ciprofloxacin may increase their MICs to oxacillin. Electronic Publication  相似文献   
13.
These researchers investigated the effects of a progressive resistive, cycle ergometric exercise program on cardio-vascular endurance in one rheumatoid arthritic. The 46 yr. old, male subject exercised three days/week for 14 weeks. Workouts included interval-type training using 5 minute intervals for a total of 20-30 minutes (work rate set at 50-75 watts for each interval), not including 3-minute warm-up and cool-down periods (work rate set at zero resistance). Maximal exercise stress testing on the cycle ergometer was completed and blood samples collected before and after the exercise program. Also, psychological and physical health and lifestyle data were gathered before, during and after completion of the program. The conditioning program produced a training effect (greater than 75% of the HR max after the second exercise session) and blood values improved (10-28%) from the beginning to the end of the program. Finally, the program appeared to have a positive influence on various physical and psychological parameters as perceived by the subject and his wife.  相似文献   
14.
15.
The interaction of the monoamine oxidase inhibitor pargyline with cultured hepatocytes has been studied. [Phenyl-3, benzyl-3H] pargyline (38 nM) rapidly enters the cells and a plateau of incorporation into a trichloroacetic acid insoluble form (monoamine oxidase) is reached after 2 hr. The level of labelling is lower in freshly isolated cells than in those in later culture. The maximum incorporation accounts for only 6% of the added radioactivity and produces a 9% inhibition of monoamine oxidase activity. The remaining [3H] pargyline is metabolized and quickly accumulates in the cell culture medium in a form which cannot label exogenous mitochondria. The metabolism of pargyline varies both qualitatively and quantitatively with culture age. In 0 hr and 20 hr-cultured cells one metabolite preferentially appears whilst in 140 hr cultured hepatocytes at least three metabolites are formed. The metabolism of [3H] pargyline in early culture is consistent with a cytochrome P-450 involvement. The use of [3H] pargyline to label monoamine oxidase in cultured hepatocytes offers several attractive features for studying the turnover of this enzyme. These include speed of interaction, non-reutilization, application to normal cells, controlled inhibition of monoamine oxidase and metabolism of non-specific label.  相似文献   
16.
A two-week elective to introduce first- and second-year medical students to primary care internal medicine was developed and evaluated. Course time is divided between conference sessions (25 percent) provided by full-time clinical faculty members and office experience (75 percent) provided by volunteer clinical faculty members (general internists in private practice and in prepaid health plans). Evaluations by the students (n = 58) who took the elective consisted of a questionnaire assessment of the conference session topics, the student's ability to carry out course objectives, and the preceptor's teaching activities. The conference topics were highly rated, with a mean score of 4.1 on a rating scale ranging from 1 (unfavorable) to 5 (favorable). The course objectives and teaching activities were also well rated, with a mean score of 4.1 and 3.9, respectively, on a rating scale ranging from 1 (none) to 5 (outstanding).  相似文献   
17.
Esophageal pH monitoring is the accepted standard for the investigation of gastroesophageal reflux (GER) in adults. A postal questionnaire was sent to 912 United Kingdom paediatric physicians & surgeons. Five hundred forty-seven (61%) replied, with 124 (22.7%) currently using the technique, mostly in conjunction with barium swallow and/or esophagoscopy. The use of pH monitoring to quantify GER was also accepted in principal as being the best determinant of reflux by a further 186 (34%), but as yet was unavailable in their hospitals. Pediatricians were also questioned as to their management of children with GER. The majority were treated medically with a variety of antireflux medication, with only 237 (42%) referring cases for surgery.  相似文献   
18.
Clinical pharmacokinetics-pharmacodynamics of anticancer drugs   总被引:3,自引:0,他引:3  
  相似文献   
19.
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