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   40168篇
  免费   2192篇
  国内免费   153篇
耳鼻咽喉   534篇
儿科学   960篇
妇产科学   785篇
基础医学   5101篇
口腔科学   2308篇
临床医学   2921篇
内科学   10301篇
皮肤病学   994篇
神经病学   3227篇
特种医学   840篇
外科学   5999篇
综合类   246篇
一般理论   13篇
预防医学   3009篇
眼科学   707篇
药学   2240篇
中国医学   146篇
肿瘤学   2182篇
  2023年   248篇
  2022年   526篇
  2021年   1445篇
  2020年   766篇
  2019年   1146篇
  2018年   1333篇
  2017年   881篇
  2016年   971篇
  2015年   1117篇
  2014年   1651篇
  2013年   2004篇
  2012年   3261篇
  2011年   3382篇
  2010年   1947篇
  2009年   1619篇
  2008年   2718篇
  2007年   2756篇
  2006年   2691篇
  2005年   2596篇
  2004年   2196篇
  2003年   2003篇
  2002年   1765篇
  2001年   243篇
  2000年   202篇
  1999年   280篇
  1998年   307篇
  1997年   244篇
  1996年   222篇
  1995年   204篇
  1994年   163篇
  1993年   122篇
  1992年   137篇
  1991年   116篇
  1990年   98篇
  1989年   70篇
  1988年   64篇
  1987年   67篇
  1986年   62篇
  1985年   62篇
  1984年   79篇
  1983年   71篇
  1982年   52篇
  1981年   61篇
  1980年   65篇
  1979年   48篇
  1978年   46篇
  1977年   51篇
  1976年   31篇
  1974年   28篇
  1973年   29篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
International Journal of Clinical Oncology - Immune-checkpoint inhibitors (ICIs) are standard treatments for metastatic non-small cell lung cancer (NSCLC). Patients with poor performance status...  相似文献   
2.
Lasers in Medical Science - Studies reported the harmful effects of 2,4-D on body tissues, provoking changes in the anatomy and physiology of the kidneys, liver, and testicles. Thus, the objective...  相似文献   
3.
4.
The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous.  相似文献   
5.
Chlorpyrifos is the most used insecticide in Argentina. Cnesterodon decemmaculatus is a widely distributed, endemic fish from Neotropical America. It attains high densities in the shallow water assemblages of Argentina and Brazil. The aim of this study was to assess the acute toxicity of chlorpyrifos to C. decemmaculatus. The mean 96-h LC50 of three independent determinations was 105.3 (±?3.1) μg/L. Sublethal effects were observed. Swimming behavioral changes at each chlorpyrifos exposure concentration were reported. C. decemmaculatus represents a good model for ecotoxicological risk assessment.  相似文献   
6.
7.
Classical Kaposi sarcoma (KS) usually appears on lower extremities accompanied or preceded by local lymphedema. However, the development in areas of chronic lymphedema of the arms following mastectomy, mimicking a Stewart–Treves syndrome, has rarely been described. We report an 81‐year‐old woman who developed multiple, erythematous to purple tumors, located on areas of post mastectomy lymphedema. Histopathological examination evidenced several dermal nodules formed by spindle‐shaped cells that delimitated slit‐like vascular spaces with some red cell extravasation. Immunohistochemically, the human herpesvirus type 8 (HHV‐8) latent nuclear antigen‐1 was detected in the nuclei of most tumoral cells confirming the diagnosis of KS. Lymphedema could promote the development of certain tumors by altering immunocompetence. Although angiosarcoma (AS) is the most frequent neoplasia arising in the setting of chronic lymphedema, other tumors such as benign lymphangiomatous papules (BLAP) or KS can also develop in lymphedematous limbs. It is important to establish the difference between AS and KS because their prognosis and treatment are very different. Identification by immunohistochemistry of HHV‐8 is useful for the distinction between KS and AS or BLAP.  相似文献   
8.
9.
10.
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