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   220086篇
  免费   20249篇
  国内免费   15480篇
耳鼻咽喉   1903篇
儿科学   2196篇
妇产科学   2982篇
基础医学   26578篇
口腔科学   3689篇
临床医学   30837篇
内科学   32949篇
皮肤病学   2228篇
神经病学   12394篇
特种医学   8273篇
外国民族医学   138篇
外科学   21731篇
综合类   35402篇
现状与发展   55篇
一般理论   19篇
预防医学   13153篇
眼科学   6703篇
药学   22742篇
  194篇
中国医学   12386篇
肿瘤学   19263篇
  2024年   698篇
  2023年   3558篇
  2022年   9198篇
  2021年   11567篇
  2020年   8604篇
  2019年   7597篇
  2018年   8034篇
  2017年   7086篇
  2016年   6656篇
  2015年   10254篇
  2014年   12552篇
  2013年   10692篇
  2012年   16006篇
  2011年   17948篇
  2010年   10523篇
  2009年   8187篇
  2008年   11115篇
  2007年   11091篇
  2006年   11234篇
  2005年   11325篇
  2004年   6998篇
  2003年   6614篇
  2002年   5498篇
  2001年   4936篇
  2000年   5346篇
  1999年   5687篇
  1998年   3533篇
  1997年   3502篇
  1996年   2824篇
  1995年   2617篇
  1994年   2147篇
  1993年   1381篇
  1992年   1892篇
  1991年   1596篇
  1990年   1291篇
  1989年   1097篇
  1988年   1018篇
  1987年   893篇
  1986年   731篇
  1985年   530篇
  1984年   338篇
  1983年   242篇
  1982年   154篇
  1981年   147篇
  1980年   116篇
  1979年   143篇
  1978年   50篇
  1977年   55篇
  1975年   59篇
  1974年   56篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
慢性心力衰竭病人的临床分析   总被引:1,自引:1,他引:0  
刘涛 《护理研究》2007,21(5):1335-1335
慢性心力衰竭(CHF)目前是老年人住院和死亡的主要原因,近几年研究结果显示CHF病人出现的肾功能障碍即心肾综合征发病率高,预后差,狭义的心肾综合征特指CHF引起的进行性肾功能损害,并导致肾功能不全,我们回顾性分析我院收治的100例CHF住院病人,着重探讨CHF程度与肾功能不全的发生率及其与住院的时间的关系。现将其临床分析介绍如下。  相似文献   
102.
103.
104.
105.
106.
Forty of the 87 patients with microinvasive carcinoma (MIC) of the uterine cervix who underwent surgery were diagnosed colposcopically and the results were compared with the cytological and histological diagnoses. The cytology showed preinvasive carcinoma in 20 (50.0%) patients and invasive carcinoma in 19 (47.5%) patients. A correct colposcopic diagnosis was made in nine (22.5%) patients as having microinvasive carcinoma, 21 (52.5%) patients preinvasive carcinoma and eight (20%) patients invasive carcinoma, to sum up accuracy rate as 32.1%. The abnormalities most commonly observed in colposcopy were mosaic, punctuation and white epithelium. In microinvasive carcinoma, the triad co-existed in 43% of the patients. Atypical vessels, characteristic of invasion, were found in only one third of the patients. Microinvasion, therefore, may not be evident on colposcopy alone. It is therefore necessary to apply cone biopsy, prior to definite therapy, to make an accurate assessment of the maximum depth and extent of the invasion prior to definitive therapy.  相似文献   
107.
The study of immunoglobulin genes has been an active area of research in recent years. The study of IgE heavy (epsilon) chain gene, in particular, has a significant impact on our understanding of the IgE system. The localization of the epsilon gene in the cluster of mouse heavy chain constant region genes has been determined, and models for gene rearrangements leading to epsilon chain gene expression have been provided. The regulation of IgE antibody production can thus be discussed in the context of these models in combination with knowledge of the cellular basis of IgE production. Comparison of the epsilon chain sequence among human, rat, and mouse has allowed a better understanding of the evolution and structure-function relationship of the epsilon chain. Furthermore, expression of epsilon chain cDNA in Escherichia coli and demonstration of biological activities of expression products have paved the basis for identification of defined peptides representing the structures for recognition by IgE receptors. These studies are discussed in this review.  相似文献   
108.
A new DRB1 allele, DRB1*0902, has been identified in an individual of the Jing ethnic minority. Its sequence was confirmed by sequencing of PCR products and clones. This allele differed by three nucleotides from DRB1*09012 at positions 157, 161 and 166, and resulted in amino acid motif substitution from VAES to DAEY.  相似文献   
109.
目的 评价善宁对顽固性大咯血的疗效。方法 将55例传统药物抢救无效或有禁忌的大咯血分为治疗组(善宁)与对照组(立止血组),观察24—72h的止血效果。结果 治疗组总有效率为92%,对照组为70%,两组比较有显著差异p〈0.05(x^2=4.125)。结论 善宁治疗大咯血疗效显著,使用安全,不良反应少,值得临床推广应用。  相似文献   
110.
E M Spencer  C C Liu  E C Si  G A Howard 《BONE》1991,12(1):21-26
The in vivo action of insulin-like growth factor-I on bone metabolism has been studied using a new model. Insulin-like growth factor-I (IGF-I) was continuously infused into the arterial supply of the right hindlimb of ambulatory rats for up to 14 days and the effects on cortical and trabecular bone formation and the number of osteoclasts were determined by histomorphometric techniques. The contralateral limb acted as an internal control. IGF-I infusion significantly increased cortical bone formation (p less than 0.01). Trabecular bone was increased 22% (p = 0.07), but the infusion was only for seven days. These effects of IGF-I were age dependent, being absent in young, rapidly growing animals, but present at least until one year of age. IGF-I appears to be a purely anabolic hormone for bone formation, since it significantly stimulates osteoblasts and decreases the number of osteoclasts. Thus, although IGF-I mediates the growth-promoting effect of growth hormone, it does not mediate growth hormone's action on bone resorption.  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