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   27522篇
  免费   2942篇
  国内免费   893篇
耳鼻咽喉   79篇
儿科学   623篇
妇产科学   239篇
基础医学   6641篇
口腔科学   375篇
临床医学   2007篇
内科学   4830篇
皮肤病学   424篇
神经病学   1996篇
特种医学   389篇
外国民族医学   4篇
外科学   1807篇
综合类   3414篇
现状与发展   13篇
一般理论   1篇
预防医学   1999篇
眼科学   328篇
药学   2450篇
  11篇
中国医学   1512篇
肿瘤学   2215篇
  2024年   143篇
  2023年   747篇
  2022年   1170篇
  2021年   1686篇
  2020年   1290篇
  2019年   1112篇
  2018年   1007篇
  2017年   1149篇
  2016年   1178篇
  2015年   1146篇
  2014年   1495篇
  2013年   1977篇
  2012年   1396篇
  2011年   1386篇
  2010年   1239篇
  2009年   1199篇
  2008年   1133篇
  2007年   1099篇
  2006年   1033篇
  2005年   908篇
  2004年   802篇
  2003年   667篇
  2002年   632篇
  2001年   606篇
  2000年   486篇
  1999年   401篇
  1998年   400篇
  1997年   327篇
  1996年   336篇
  1995年   312篇
  1994年   262篇
  1993年   241篇
  1992年   218篇
  1991年   222篇
  1990年   161篇
  1989年   163篇
  1988年   177篇
  1987年   157篇
  1986年   152篇
  1985年   177篇
  1984年   198篇
  1983年   111篇
  1982年   168篇
  1981年   104篇
  1980年   93篇
  1979年   82篇
  1978年   49篇
  1977年   45篇
  1976年   56篇
  1973年   22篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Evidence from the literature is reviewed to suggest that when fingertip dermal ridge patterns in chromosomal deletion syndromes are characteristic of the opposite spectrum of the developmental scale from patterns found in cases trisomic for the same chromosomal region, the association may be a consequence of loci with growth regulatory functions. Evidence is presented that DNA markers at 18q21 should be the first candidate sequences to be used to test this hypothesis in families with fingertip arches segregating in an apparent autosomal dominant fashion.  相似文献   
52.
Cerebral cell volume regulatory mechanisms are activated by sustained disturbances in plasma osmolality. Acute hypernatremia causes a predictable shrinkage of brain cells due to the sudden imposition of a plasma-to-cell osmolal gradient. However, during chronic hypernatremia cerebral cell volume is maintained close to the normal range as a result of the accumulation of electrolytes and organic osmolytes including myo-inositol, taurine, glutamine, glycerophosphorylcholine, and betaine. The increased cytosolic level of these molecules is generally accomplished via increased activity of sodium (Na+)-dependent cotransport systems. The slow dissipation of these additional osmotically active solutes from the cell during treatment of hypernatremia necessitates gradual correction of this electrolyte abnormality. Acute hyponatremia leads to cerebral cell swelling and severe neurological dysfunction. However, prolonged hyponatremia is associated with significant reductions in brain cell electrolyte and organic osmolyte content so that cerebral cell volume is restored to normal. While acute hyponatremia can be treated with the administration of moderate doses of hypertonic saline in order to control seizure activity, chronic hyponatremia should be corrected slowly in order to prevent subsequent neurological deterioration. If the rate of correction exceeds 0.5 mmol/l per hour, or if the total increment in serum [Na+] exceeds 25 mmol/l in the first 48 h of therapy, then there is an increased risk of the development of cerebral demyelinating lesions. Chronic hyperglycemia activates the brain cell volume regulatory adaptations in the same manner as hypernatremia. Therefore, during the treatment of diabetic ketoacidosis, it is imperative to restore normoglycemia gradually in order to prevent the occurrence of cerebral edema. It is possible that excessive administration of electrolyte-free solutions and high doses of insulin may increase the risk of this complication. While there are some data to suggest that brain cell size is disturbed during acute uremia, additional work is necessary to clarify the role of cerebral cell volume regulation during acute and chronic uremia.  相似文献   
53.
建立新型医患关系是医院工作的当务之急   总被引:7,自引:5,他引:2  
《医疗事故处理条例》《最高人民法院关于民事诉讼证据的若干规定》这两个法规的出台,给医院提出了新的课题,结合目前实际,提出了医院全面贯彻执行这两个法规,必须从围绕改善医患关系这个中心问题入手。建立新型和医患关系,并根据多年的观察与实践,着重论述了如下见解:医务人员在为患者的攻关服务过程中,要真正认识自己是医患矛盾中的主要方面;医务人员要转变传统的服务思维定势,尊重和理解患者,医务人员要确立既为患者生命和利益负责,又重视患者权利的观念,医务人员要增强法制观念,做到依法行医,医院要设置监控部门或配备专兼职人员,对全院的医疗服务进行检查监督。  相似文献   
54.
In activated murine B lymphocytes, immunoglobulin class switch recombination occurs as a highly regulated process which is targeted to distinct switch regions. Here we present first evidence that in human B lymphocytes, switch recombination is targeted to distinct switch regions as well. In a panel of clonally unrelated IgG1-expressing human B cells, immortalized by Epstein-Barr virus (EBV) transformation, seven out of nine cells show switch recombination between Sμ and Sγ1 on both alleles, the active and inactive one. The remaining cells show no switch recombination on the inactive IgH locus. The very strong correlation of switch recombination on both alleles of IgG1-expressing cells proves that class switch recombination to IgG1 is not random but directed in human B lymphocytes.  相似文献   
55.
Intravenous immunoglobulin (IVIG) products are derived from pooled human plasma and have been used for the treatment of primary immunodeficiency disorders for more than 24 years. Shortly after their introduction, IVIG products were also found to be effective in the treatment of autoimmune and inflammatory disorders. Over the past 2 decades, the list of diseases where IVIG has a demonstrable beneficial effect has grown rapidly. These include Kawasaki disease, Guillain-Barre syndrome, myasthenia gravis, dermatomyositis and demyelinating polyneuropathy. Recently, we have described a beneficial effect on the reduction of anti-HLA antibodies with subsequent improvement in transplantation of highly HLA-sensitized patients as well as a potent anti-inflammatory effect that is beneficial in the treatment of antibody-mediated rejection (AMR). These advancements have enabled transplantation of patients previously considered untransplantable. These studies and relevant mechanism(s) of action will be discussed here.  相似文献   
56.
57.
Clinical studies have demonstrated that measures of cell-mediated immune function are altered in bereaved persons and depressed patients. This review article focuses on our recent observations of changes in T cell subpopulations and natural killer cytotoxicity in women undergoing adverse life events including conjugal bereavement. A reduction in natural cytotoxicity has also been found in depressed patients. The mechanism by which psychologic states might influence immune function is discussed.  相似文献   
58.
本文用反复静脉注射小剂量牛血清白蛋白复制家兔慢性肾炎,用羊踯躅根治疗。同时,用该药对慢性肾炎病人进行疗效观察。阳性组兔肾小球呈现中至重度颗粒形免疫荧光,肾组织呈明显慢性硬化性肾小球肾炎改变。尿蛋白±~++。治疗组兔及病人治疗后病变及症状均明显减轻或消失。结果提示循环免疫复合物反复沉着可引起兔类似人类的慢性硬化性肾小球肾炎,羊踯躅根对病变有一定的控制和治疗作用,这可能与其抑制免疫发病机制有关。  相似文献   
59.
60.
带状疱疹患者红细胞免疫功能的测定   总被引:1,自引:1,他引:0  
采用红细胞酵母菌花结试验检测了32例带状疱疹患者的红细胞免疫粘附活性。结果显示:疾病组红细胞C3b受体花环率(7.76±1.76%)较对照组(9.46±l.73%)明显降低(P<0.01),而红细胞免疫复合物花环率(9.92±1.99%)较对照组(4.71±2.28%)明显增高(P<0.01)。  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