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   4333篇
  免费   323篇
  国内免费   9篇
耳鼻咽喉   58篇
儿科学   101篇
妇产科学   56篇
基础医学   697篇
口腔科学   35篇
临床医学   376篇
内科学   1049篇
皮肤病学   78篇
神经病学   305篇
特种医学   162篇
外科学   899篇
综合类   23篇
一般理论   1篇
预防医学   264篇
眼科学   24篇
药学   274篇
中国医学   6篇
肿瘤学   257篇
  2023年   17篇
  2022年   25篇
  2021年   61篇
  2020年   49篇
  2019年   65篇
  2018年   86篇
  2017年   63篇
  2016年   86篇
  2015年   71篇
  2014年   108篇
  2013年   163篇
  2012年   278篇
  2011年   291篇
  2010年   173篇
  2009年   157篇
  2008年   260篇
  2007年   264篇
  2006年   302篇
  2005年   252篇
  2004年   260篇
  2003年   243篇
  2002年   230篇
  2001年   61篇
  2000年   47篇
  1999年   56篇
  1998年   74篇
  1997年   52篇
  1996年   50篇
  1995年   49篇
  1994年   41篇
  1993年   28篇
  1992年   38篇
  1991年   37篇
  1990年   54篇
  1989年   41篇
  1988年   42篇
  1987年   34篇
  1986年   41篇
  1985年   35篇
  1984年   31篇
  1983年   32篇
  1982年   26篇
  1981年   26篇
  1980年   23篇
  1979年   29篇
  1978年   18篇
  1977年   17篇
  1975年   20篇
  1974年   19篇
  1973年   22篇
排序方式: 共有4665条查询结果,搜索用时 15 毫秒
71.
The present paper aims at reviewing our present knowledge on the diagnosis of deep vein thrombosis and pulmonary embolism with a particular emphasis on clinically suspected outpatients. The various contemporary diagnostic tools (including clinical probability assessment, fibrin D-Dimer measurement, venous compression ultrasonography, ventilation/perfusion lung scintigraphy, helical CT scan, and echocardiography) are presented and rational sequential strategies are discussed in their various aspects, including validation in outcome studies, and cost-effectiveness analyses.  相似文献   
72.
Introduction: Ocular surface diseases with limbal insufficiency represent a therapeutic challenge for restoring vision. This corneal deficiency includes both classical ocular diseases (as chemical burns) and rare ocular diseases (as congenital aniridia and ocular cicatricial pemphigoid).

Areas covered: Our understanding of limbal epithelial stem cells (LESCs) has increased the potential for treatment options. Pharmacological treatment strategies (as regenerating agent ophthalmic solutions) and especially surgical treatment strategies are available. Isolated LESCs can be produced by limbal primary cultures obtained from explants or cell suspensions. We review the latest cornea surgery techniques.

Expert opinion: The adjunction of human limbal mesenchymal cells as a support for limbal stem cell primary cultures appears to be of great interest. Recently, human-induced pluripotent stem cells have allowed the generation of minicorneal organoids. This potential means of creating a three-dimensional cornea with in vitro maturation opens up important research areas for corneal regeneration therapy.  相似文献   

73.
Hydrogen sulfide (H2S) has become a molecule of high interest in recent years, and it is now recognized as the third gasotransmitter in addition to nitric oxide and carbon monoxide. In this review, we discuss the recent literature on the physiology of endogenous and exogenous H2S, focusing upon the protective effects of hydrogen sulfide in models of hypoxia and ischaemia.

Linked Articles

This article is part of a themed section on Pharmacology of the Gasotransmitters. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-6  相似文献   
74.
75.
76.
Cloninger has proposed a tridimensional model as the basis for the classification of personality variants and has developed the Tridimensional Personality Questionnaire (TPQ) as an empirical test of this model. In this study, the TPQ was administered to two groups of young men. One group was comprised of nonalcoholic sons of male alcoholics; the other group consisted of nonalcoholic men with no family history of alcoholism. Since the sons of male alcoholics are considered to be at greater risk to develop alcoholism than the sons of nonalcoholics, it was hypothesized that the two groups would demonstrate differences with regard to one or more personality variants as measured by the TPQ. No statistically significant differences in the three TPQ-subscale scores of the two groups were found.  相似文献   
77.
78.
79.
A number of hematologic abnormalities, including cytopenias, have been observed in patients with human immunodeficiency virus (HIV) infection. To elucidate their mechanisms, a group of 27 patients with HIV-1 infection was studied. In all patients, a marked reduction of in vitro colony formation by erythroid, granulomacrophagic, and megakaryocytic bone marrow progenitors was observed in comparison to normal donors. HIV-1 infection of marrow progenitors was investigated in studying individual colonies with the polymerase chain reaction (PCR) technique. No HIV-1 DNA could be detected in these colonies, suggesting either that marrow progenitors were not infected or that infected progenitors were not able to generate colonies in vitro. The addition of antisense oligonucleotides directed against HIV tat or nef sequences in the culture medium led to a significant increase in colony formation, suggesting that HIV replication in hematopoietic progenitors could be responsible for their defective growth. However, no HIV-1-infected colonies could be detected by PCR after the antisense treatment, indicating that the increase in colony number was not due to the proliferation and differentiation of infected progenitors but to an inhibition of HIV replication in an accessory cell. This last hypothesis was further confirmed by the absence of effects of antisense oligomers on the plating efficiency of hematopoietic progenitors grown from CD34+ cells. These data indicate that hematologic abnormalities of HIV-infected patients cannot be explained by a direct infection of hematopoietic progenitor cells and suggest that a defective modulation of progenitor cell growth by HIV replication outside these cells might play a role in these abnormalities.  相似文献   
80.
Two patients exhibiting a highly unusual preleukemic syndrome with marked reticulocytosis, hypochromia, and microcytosis are reported. This red cell phenotype has been investigated by means of HbF, HbA2, and i-antigen activity dosages, immunofluorescence labeling of F cells, reticulocyte survival, globin chain synthesis, and electron microscopy study. The marked reticulocytosis is explained by a delayed disappearance of the reticulum. Serum iron is normal, and a thalassemic syndrome is excluded because of a balanced alpha/non-alpha globin chain synthesis. Electron microscopy studies are consistent with a defect in iron uptake by erythroid cells. All the hematologic data and investigations are similar to those observed for the Belgrade laboratory rat. It is hypothesized that the low expression of HbF and i- Ag associated with microcytosis are related to a prolongation of erythroid maturation as reflected by abnormal reticulocyte survival.  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