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   418篇
  免费   30篇
  国内免费   5篇
耳鼻咽喉   3篇
儿科学   18篇
妇产科学   4篇
基础医学   88篇
口腔科学   16篇
临床医学   47篇
内科学   71篇
皮肤病学   4篇
神经病学   11篇
特种医学   34篇
外科学   51篇
综合类   29篇
预防医学   20篇
眼科学   2篇
药学   36篇
中国医学   2篇
肿瘤学   17篇
  2022年   4篇
  2021年   8篇
  2019年   5篇
  2018年   8篇
  2015年   6篇
  2014年   13篇
  2013年   4篇
  2012年   12篇
  2011年   7篇
  2010年   6篇
  2009年   12篇
  2008年   15篇
  2007年   14篇
  2006年   11篇
  2005年   6篇
  2004年   5篇
  2003年   7篇
  2002年   10篇
  2001年   8篇
  2000年   5篇
  1999年   11篇
  1998年   20篇
  1997年   15篇
  1996年   13篇
  1995年   8篇
  1994年   10篇
  1993年   8篇
  1992年   5篇
  1991年   5篇
  1990年   16篇
  1989年   11篇
  1988年   15篇
  1987年   17篇
  1986年   18篇
  1985年   8篇
  1984年   7篇
  1983年   10篇
  1981年   7篇
  1979年   5篇
  1978年   9篇
  1977年   6篇
  1975年   9篇
  1974年   6篇
  1973年   6篇
  1972年   7篇
  1971年   5篇
  1970年   5篇
  1969年   3篇
  1968年   3篇
  1967年   3篇
排序方式: 共有453条查询结果,搜索用时 156 毫秒
1.
2.
本文建立了体液中右旋儿茶素的RP-HPLC测定方法。采用C_(18)键合相硅胶为填料的固相提取柱进行样品预处理,右旋儿茶素的提取回收率为79.8%.应用二极管阵列检测器对色谱峰纯度进行鉴定。该法精密度好,方法回收率近100%,日内、日间的变异系数为2.4~5.6%,血浓69.6~1160 ng/ml范围内呈线性关系,r=0.9993。家兔静注右旋儿茶素18mg/kg,其药代动力学过程符合二室模型,分布相半衰期为0.129 h,消除相半衰期为1.19h。  相似文献   
3.
4.
5.
6.
The UTX gene escapes X inactivation in mice and humans   总被引:7,自引:3,他引:7  
We recently have identified a ubiquitously transcribed mouse Y chromosome gene, Uty , which encodes a tetratricopeptide repeat (TPR) protein. A peptide derived from the UTY protein confers H-Y antigenicity on male cells. Here we report the characterization of a widely transcribed X-linked homologue of Uty , called Utx , which maps to the proximal region of the mouse X chromosome and which detects a human X-linked homologue at Xp11.2. Given that Uty is ubiquitously transcribed, we assayed for Utx expression from the inactive X chromosome (Xi) in mice and found that Utx escapes X chromosome inactivation. Only Smcx and the pseudoautosomal Sts gene on the mouse X chromosome have been reported previously to escape inactivation. The human UTX gene was also found to be expressed from Xi. We discuss the significance of these data for our understanding of dosage compensation of X-Y homologous genes in humans and mice.   相似文献   
7.
L1 is a neural cell adhesion molecule mainly involved in axon guidance and neuronal migration during brain development. Mutations in the human L1 gene give rise to a complex clinical picture, with mental retardation, neurologic abnormalities and a variable degree of hydrocephalus. Recently, a transgenic mouse model with a targeted null mutation in the L1 gene was generated. These knockout (KO) mice show hypoplasia of the corticospinal tract. Here we have performed further studies of these KO mice including magnetic resonance imaging of the brain, neuropathological analysis and behavioral testing. The ventricular system was shown to be abnormal with dilatation of the lateral ventricles and the 4th ventricle, and an altered shape of the Sylvius aqueduct. Additionally, the cerebellar vermis of the KO mice is hypoplastic. Their exploratory behavior is characterized by stereotype peripheral circling reminiscent of that of rodents with induced cerebellar lesions.   相似文献   
8.
An examination of 1525 patients has established that the main clinical symptoms of the perifocal inflammatory process are: hyperthermia of different degrees, leukocytosis and higher ESR, pain in the rectum area and in the abdomen, tenderness and pasty tissues in the tumor area. The roentgenological symptoms are: the presence of fistulas, considerable dilatation of presacral space not corresponding to the tumor size, pathological "cellularity" of the paraintestinal tissues.  相似文献   
9.
Lung carcinoma remains one of the most frequent and aggressive human neoplasms. Fortunately, in the last decades, the increasing knowledge of the molecular mechanisms leading to cancer development has allowed the use of targeted therapies with improvement of prognosis in many patients. Clinical management has also changed after the introduction of endobronchialultrasonographic bronchoscopy that allows a conservative staging of lung tumors, avoiding the need of mediastinoscopy for lymph node staging. Lung pathologists and cytopathologists are facing the challenge of giving the more comprehensive prognostic and predictive information with ever smaller tissue or cytological samples. The aim of this review is to summarize the molecular testing for non-small cell lung carcinoma and how pathologists can contribute to the patient's outcome with a conscious management of biological samples.  相似文献   
10.
The authors share their experiences with treatment of wounds of the neck in 210 patients. Major vessels were injured in 85 of them (40.5%), arterial vessels being injured in 19 patients, venous vessels in 23 patients. 43 patients had wounds of the hollow, parenchymatous organs and nerves. All the patients with wounds of the hollow and parenchymatous organs recovered. Lethality among the patients with wounds of the major vessels was 11.9% and was due to a combination of injuries of the vessels and blood loss incompatible with life. Active surgical treatment of penetrating wounds of the neck with careful revision of the wound, use of emergency esophagogastroduodenoscopy, laryngotracheobronchoscopy, X-ray examination allow the amount of diagnostic errors and lethality to be reduced.  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