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   875164篇
  免费   71619篇
  国内免费   1887篇
耳鼻咽喉   12979篇
儿科学   24908篇
妇产科学   25292篇
基础医学   125788篇
口腔科学   25880篇
临床医学   76651篇
内科学   167570篇
皮肤病学   17152篇
神经病学   71138篇
特种医学   35764篇
外国民族医学   171篇
外科学   138014篇
综合类   24885篇
现状与发展   2篇
一般理论   278篇
预防医学   67915篇
眼科学   20971篇
药学   65600篇
中国医学   1623篇
肿瘤学   46089篇
  2018年   7515篇
  2015年   7944篇
  2014年   11451篇
  2013年   17375篇
  2012年   23409篇
  2011年   24581篇
  2010年   14272篇
  2009年   13463篇
  2008年   23304篇
  2007年   25476篇
  2006年   25377篇
  2005年   24974篇
  2004年   24575篇
  2003年   23653篇
  2002年   22741篇
  2001年   35935篇
  2000年   36542篇
  1999年   31036篇
  1998年   9419篇
  1997年   8726篇
  1996年   8632篇
  1995年   8179篇
  1994年   7846篇
  1992年   26740篇
  1991年   26181篇
  1990年   25704篇
  1989年   24761篇
  1988年   23305篇
  1987年   22954篇
  1986年   21819篇
  1985年   21199篇
  1984年   16530篇
  1983年   14126篇
  1982年   9043篇
  1981年   8382篇
  1980年   7812篇
  1979年   16816篇
  1978年   12212篇
  1977年   10301篇
  1976年   9448篇
  1975年   10254篇
  1974年   12708篇
  1973年   12221篇
  1972年   11599篇
  1971年   10727篇
  1970年   10266篇
  1969年   9953篇
  1968年   8933篇
  1967年   8265篇
  1966年   7679篇
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
81.
82.
To test the reported antipanic efficacy of clonazepam, the authors randomized 72 subjects with panic disorder to 6 weeks of treatment with either alprazolam, clonazepam, or placebo. Endpoint analysis demonstrated a significant beneficial effect of both active treatments, but not placebo treatment, on the frequency of panic attacks, overall phobia ratings, and the extent of disability. Comparison of the two active treatments revealed no significant differences and no consistent tendency for one agent to be favored over another, although power to detect small differences was limited. Sedation and ataxia were the most common side effects reported, but these effects were mild and transient and did not interfere with treatment outcome. The results of this double-blind, placebo-controlled trial are consistent with previous reports of clonazepam's antipanic efficacy.  相似文献   
83.
In 1981 a statewide program supplying free insulin to 3,720 patients of state health clinics was discontinued. We attempted to assess whether this action had an adverse effect medically and financially on those concerned. A computer randomized sample of 351 patients (9%) was studied by personal interview and questionnaire. Information obtained focused on certain events that occurred 18 months before and after the program ceased. Measurements used to determine medical impact were number of hospitalizations, emergency room and physician visits, changes in weight and glucose levels, and episodes of ketoacidosis. Financial impact was measured by cost of hospitalization and physician visits. Our results revealed no significant changes in any of the medical parameters studied except for fasting serum glucose levels above 300 mg/dl, which occurred less frequently after the free insulin program was discontinued. There were fewer hospitalizations, more visits to physicians, and no change in number of emergency room visits after discontinuance of the free program. The overall cost saving was estimated to be +883,558 for the 18-month study period, in addition to the +550,000 the plan had been costing the state.  相似文献   
84.
85.
The administration of prophylactic antibiotics in surgery is appropriate for many patients. Data have shown extending the duration of prophylaxis beyond 48 hours does not lower the rate of postoperative-infection. The purpose of this project was to concurrently assess the duration of prophylactic antibiotic use. A total of 95 patients were monitored over 3 weeks. Eighty patients (84.2%) received antimicrobial therapy. In 23 of these patients (28.75%) the duration of antibiotic administration was longer than 2 days without clinical or microbiological evidence of infection. In 5 other patients only postoperative antibiotics were prescribed. The cost difference between the actual duration of antibiotic administration and 2 days of the same regimen was +1,364.58. Extrapolating for one year, it can be estimated that antibiotic costs could be reduced about +23,600. Pharmacists can focus on the duration of antibiotic prophylaxis as a cost containment measure.  相似文献   
86.
The percentage uptake of [123I]metaiodobenzylguanidine (MIBG) by tumors of the paraganglion system is compared with the number of neurosecretory granules (assessed by both light and electron microscopy) in the subsequently resected tumors in six patients. Iodine-123 MIBG was injected intravenously; the tumor uptake of [123I]MIBG varied between 0.001% and 0.14% of the injected dose per gram of tumor tissue at 22 hr. The number of neurosecretory granules in tissue sections was scored on a scale of I-III. A direct proportional correlation was found between the percentage uptake of [123I]MIBG by the tumor and the number of neurosecretory granules in the tissue sections but not with plasma or urinary catecholamines. This technique for imaging reflects the storage status of the tumor better than plasma and urinary catecholamine measurements.  相似文献   
87.
88.
Abstract A high frequency of serum complement component C4A deficiency may explain the higher prevalence and greater severity of systemic lupus erythematosus reported in Australian Aborigines. Inherited deficiencies of serum complement components C4A, C4B, and C2 were examined in two Australian Aboriginal populations from Darwin and Alice Springs and compared with the prevalence of complement deficiencies in white Australian blood donors. The frequency of C4A deficiency alleles was 29% in Darwin Aborigines compared with 12% in Alice Springs and 17% in Canberra blood donors. Partial C4B deficiency was also higher in Darwin Aborigines than in the other populations. Inherited deficiency of serum complement component C2 was not observed.  相似文献   
89.
90.
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