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   3374713篇
  免费   268366篇
  国内免费   6046篇
耳鼻咽喉   48535篇
儿科学   107596篇
妇产科学   93099篇
基础医学   475185篇
口腔科学   99606篇
临床医学   306836篇
内科学   653300篇
皮肤病学   70366篇
神经病学   280915篇
特种医学   134362篇
外国民族医学   1247篇
外科学   507174篇
综合类   82974篇
现状与发展   4篇
一般理论   1426篇
预防医学   272358篇
眼科学   79816篇
药学   252442篇
  7篇
中国医学   6252篇
肿瘤学   175625篇
  2018年   33646篇
  2016年   28931篇
  2015年   33063篇
  2014年   46954篇
  2013年   71797篇
  2012年   96522篇
  2011年   102072篇
  2010年   60310篇
  2009年   57576篇
  2008年   97187篇
  2007年   102956篇
  2006年   104108篇
  2005年   101236篇
  2004年   98267篇
  2003年   94573篇
  2002年   93378篇
  2001年   153555篇
  2000年   159020篇
  1999年   135005篇
  1998年   39165篇
  1997年   35507篇
  1996年   35005篇
  1995年   33943篇
  1994年   31942篇
  1993年   29875篇
  1992年   109712篇
  1991年   106084篇
  1990年   102974篇
  1989年   99488篇
  1988年   92474篇
  1987年   91234篇
  1986年   86639篇
  1985年   83063篇
  1984年   63014篇
  1983年   54083篇
  1982年   32672篇
  1981年   29182篇
  1980年   27499篇
  1979年   59844篇
  1978年   42101篇
  1977年   35531篇
  1976年   33319篇
  1975年   35270篇
  1974年   43500篇
  1973年   41551篇
  1972年   38714篇
  1971年   36031篇
  1970年   33652篇
  1969年   31426篇
  1968年   28662篇
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
991.
992.
Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m2 as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m2×2 doses of ara-C and 50 mg/m2 of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182  相似文献   
993.
Rat brain hippocampal slices were incubated with or without the convulsant 4-aminopyridine (4-AP). From these slices a crude mitochondrial/synaptosomal membrane fraction was prepared and analyzed for endogenous protein phosphorylation. 4-AP (10(-5) M) stimulated the phosphorylation of a 50 kDa protein by 86%. The phosphorylation of this 50 kDa protein is Ca2+/calmodulin-dependent and we suggest that this protein is the lower molecular weight subunit of Ca2+/calmodulin-dependent protein kinase II (CaMK II).  相似文献   
994.
Platelet antibodies in systemic lupus erythematosus   总被引:2,自引:0,他引:2  
In systemic lupus erythematosus (SLE), the precise cause of the thrombocytopenia is unknown. Since platelet associated IgG is increased in many patients, it has been suggested that the destruction of platelets might be dependent on specific antibodies. In nine patients with SLE, platelet associated immunoglobulins were found together with free serum antibody which bound to platelets from all normal subjects. Using an immunoblotting technique with membrane proteins from normal platelets incubated with patient sera, target antigens were localized on a band of mol wt 108,000 in two cases (B. and N.) and on a band of mol wt 66,000 in a third (M.). When the same technique was applied to autologous platelets of patient N., autoantibody binding to the protein of mol wt 108,000 was demonstrated. The antigenic determinants were not removed from the platelets by enzyme treatment or by disulphide bond reduction, and were localized in the cytoplasmic fraction of the platelets.  相似文献   
995.
996.
997.
998.
Prognosis of epilepsy   总被引:1,自引:0,他引:1  
It has been a widely accepted view that epilepsy is usually a chronic condition in which the prognosis is generally poor and any remissions that do occur are usually temporary. In this article recent studies challenging this view will be considered, other aspects of the long-term prognosis for seizure control in epilepsy reviewed, and the mortality rates and causes of premature death in epilepsy outlined.  相似文献   
999.
The use of parenteral nutrition is becoming more widespread. The need for individualized parenteral nutrition solutions in pediatric patients makes the ordering and preparation of these solutions more complex and error-prone. A computer program is described which performs comprehensive management of parenteral nutrition by assisting in accurately ordering and preparing parenteral nutrition solutions. It also performs extensive error-checking and provides additional nutritional information. Data base management is also a feature which permits future large scale analysis of parenteral nutrition data for research purposes. This program, designed to run on a personal computer, is very comprehensive, yet flexible and user-friendly.  相似文献   
1000.
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