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   9080篇
  免费   578篇
  国内免费   46篇
耳鼻咽喉   83篇
儿科学   431篇
妇产科学   226篇
基础医学   1257篇
口腔科学   375篇
临床医学   800篇
内科学   2193篇
皮肤病学   219篇
神经病学   869篇
特种医学   220篇
外科学   1225篇
综合类   55篇
一般理论   4篇
预防医学   556篇
眼科学   201篇
药学   528篇
中国医学   26篇
肿瘤学   436篇
  2023年   51篇
  2022年   117篇
  2021年   273篇
  2020年   138篇
  2019年   225篇
  2018年   273篇
  2017年   186篇
  2016年   259篇
  2015年   276篇
  2014年   290篇
  2013年   418篇
  2012年   645篇
  2011年   625篇
  2010年   379篇
  2009年   335篇
  2008年   532篇
  2007年   578篇
  2006年   489篇
  2005年   485篇
  2004年   476篇
  2003年   389篇
  2002年   389篇
  2001年   117篇
  2000年   98篇
  1999年   114篇
  1998年   66篇
  1997年   66篇
  1996年   56篇
  1995年   45篇
  1994年   37篇
  1993年   53篇
  1992年   52篇
  1991年   51篇
  1990年   44篇
  1989年   46篇
  1988年   39篇
  1987年   40篇
  1986年   28篇
  1985年   37篇
  1984年   36篇
  1983年   28篇
  1982年   25篇
  1981年   22篇
  1980年   28篇
  1977年   27篇
  1976年   25篇
  1975年   29篇
  1931年   23篇
  1923年   19篇
  1916年   18篇
排序方式: 共有9704条查询结果,搜索用时 406 毫秒
991.
992.
993.
Ezrin, radixin, and moesin (ERM proteins), as well as the neurofibromatosis 2 (NF2) tumor suppressor merlin/schwannomin, all belong to the protein 4.1 family, yet only merlin is a tumor suppressor in Schwann cells. To gain insight into the possible functions of ERM proteins in Schwann cells, we examined their localization in peripheral nerve, because we have previously shown that merlin is found in paranodes and in Schmidt-Lanterman incisures. All three ERM proteins were highly expressed in the microvilli of myelinating Schwann cells that surround the nodal axolemma as well as in incisures and cytoplasmic puncta in the vicinity of the node. In all of these locations, ERM proteins were colocalized with actin filaments. In contrast, ERM proteins did not surround nodes in the CNS. The colocalization of ERM proteins with actin indicates that they have functions different from those of merlin in myelinating Schwann cells.  相似文献   
994.
Previous studies suggest that cytokine-induced tissue inflammation may participate in the pathogenesis of abdominal aortic aneurysms. Serum inflammatory markers may reflect arterial inflammation in asymptomatic phases of the aneurysmal disease. We studied 120 outpatients (62 men; age, 65+/-9 years) by ultrasound evaluation of the abdominal aorta to evaluate the association of circulating levels of interleukin-6 (IL-6) with abdominal aortic diameter in subjects with normal aortic size. Aortic diameter was measured at the infrarenal level and indexed for body surface area. Seven patients with abdominal aortic dilatation (indexed aortic diameter, >1.3 cm/m2) were also identified. Plasma concentrations of IL-6, serum amyloid A (SAA), C-reactive protein (CRP), total homocysteine, and lipids were measured. Among the 113 subjects without aortic dilatation, indexed aortic diameter was positively associated with serum levels of IL-6 (P<0.01), SAA (P<0.01), and total homocysteine (P=0.01). IL-6 levels increased in a stepwise fashion among dichotomized groups of aortic size (low and high aortic diameters) and peaked in patients with aortic dilatation (2.3+/-1.2 versus 2. 7+/-0.9 versus 3.2+/-0.9 pg/mL, respectively; P for trend=0.039). None of the serum lipid measurements correlated with abdominal aortic diameter. Although CRP levels were associated with SAA levels (r=0.60; P<0.001), associations between CRP and aortic diameter were nonsignificant. In multivariate analysis, levels of IL-6 (P=0.02), SAA (P=0.001), and total homocysteine (P<0.001) were independent correlates of indexed aortic diameter. In conclusion, circulating levels of IL-6, SAA, and total homocysteine may reflect processes involved in the early phases of abdominal aortic aneurysm formation, before dilation of the abdominal aorta is established. These data support a role for chronic inflammation in the progression of asymptomatic aortic disease.  相似文献   
995.
996.
Ohne Zusammenfassung  相似文献   
997.
998.
Australian funnel-web spiders: master insecticide chemists.   总被引:3,自引:0,他引:3  
Arthropods are the most diverse animal group on the planet. Their ability to inhabit a vast array of ecological niches has inevitably brought them into conflict with humans. Although only a small minority are classified as pest species, they nevertheless destroy about a quarter of the world's annual crop production and transmit an impressive array of pathogens of human and veterinary public health importance. Arthropod pests have been controlled almost exclusively with chemical insecticides since the introduction of DDT in the 1940s. However, the evolution of resistance to many insecticides, coupled with increased awareness of the potential environmental and human and animal health impacts of these chemicals, has stimulated the search for new insecticidal compounds, novel molecular targets, and alternative control methods. Spider venoms are complex chemical cocktails that have evolved to kill or paralyze arthropod prey, and they represent a largely untapped reservoir of insecticidal compounds. This review focuses on several families of invertebrate-specific peptide neurotoxins that were isolated from the venom of Australian funnel-web spiders. These peptides are promising insecticide leads because of their selectivity for invertebrates and activity on previously unvalidated targets. These toxins should facilitate the development of novel target-based screens for new insecticide leads, while their mapped pharmacophores will provide templates for rational design of mimetics that act at these target sites. Furthermore, genes encoding these toxins can be used to improve the efficacy of insect-specific viruses.  相似文献   
999.
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