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   2375800篇
  免费   194657篇
  国内免费   4209篇
耳鼻咽喉   34266篇
儿科学   72771篇
妇产科学   62932篇
基础医学   334960篇
口腔科学   67534篇
临床医学   215535篇
内科学   468774篇
皮肤病学   47970篇
神经病学   200902篇
特种医学   95975篇
外国民族医学   886篇
外科学   360496篇
综合类   56225篇
现状与发展   1篇
一般理论   977篇
预防医学   190663篇
眼科学   55494篇
药学   177545篇
  4篇
中国医学   4365篇
肿瘤学   126391篇
  2018年   24209篇
  2016年   20578篇
  2015年   23280篇
  2014年   33538篇
  2013年   50853篇
  2012年   68749篇
  2011年   72292篇
  2010年   42493篇
  2009年   40869篇
  2008年   68787篇
  2007年   73124篇
  2006年   74029篇
  2005年   72067篇
  2004年   69368篇
  2003年   67060篇
  2002年   66299篇
  2001年   112457篇
  2000年   116542篇
  1999年   98352篇
  1998年   27873篇
  1997年   25533篇
  1996年   25458篇
  1995年   24620篇
  1994年   23167篇
  1993年   21563篇
  1992年   79410篇
  1991年   76404篇
  1990年   73587篇
  1989年   70855篇
  1988年   65865篇
  1987年   64812篇
  1986年   61348篇
  1985年   58416篇
  1984年   44234篇
  1983年   37664篇
  1982年   22897篇
  1981年   20339篇
  1980年   19044篇
  1979年   41309篇
  1978年   28998篇
  1977年   24354篇
  1976年   22841篇
  1975年   23974篇
  1974年   29644篇
  1973年   28052篇
  1972年   26241篇
  1971年   24159篇
  1970年   22754篇
  1969年   21097篇
  1968年   19141篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
In a prospective study 90 patients who had confirmed abruption of the placenta were compared with a control group. Significantly more patients who had abruptio placentae were unmarried, smoked cigarettes, received no antenatal care, had coitus within the 48 hours preceding delivery, developed intrapartum hypertension and had a lower ponderal index than the controls. More patients with abruptio placentae had proteinuria and antepartum hypertension but statistical significance was not reached. In addition, the incidence of intra-uterine growth retardation was higher in these patients.  相似文献   
952.
953.
954.
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   
955.
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   
956.
957.
958.
This study empirically examines the practices of non-physician providers (NPPs) within three large competitive health maintenance organizations (HMOs), as well as the physicians' and NPPs' views regarding the ideal role of NPPs. These roles are compared with NPP delegation patterns incorporated in the modeling methodology developed by the Graduate Medical Education National Advisory Committee (GMENAC). GMENAC recommended relatively high levels of delegation by physicians to NPPs. One of the HMO sites made use of NPPs at rates even higher than GMENAC's national ideals, while the rates at the other two were lower. The normative ideals for pediatric NPPs developed at each HMO were consistently higher than their actual roles. Concerns with acceptance and the role of NPPs are clearly no longer issues. Instead, the limits on NPP involvement appear to relate to considerations of costs, availability, and the increasing numbers of physicians competing for similar opportunities.  相似文献   
959.
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   
960.
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   
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