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   199677篇
  免费   3418篇
  国内免费   33篇
耳鼻咽喉   1381篇
儿科学   7520篇
妇产科学   3479篇
基础医学   19828篇
口腔科学   1952篇
临床医学   15002篇
内科学   35313篇
皮肤病学   1193篇
神经病学   18732篇
特种医学   9683篇
外国民族医学   11篇
外科学   31544篇
综合类   2672篇
一般理论   39篇
预防医学   20765篇
眼科学   3748篇
药学   11576篇
中国医学   640篇
肿瘤学   18050篇
  2022年   238篇
  2021年   566篇
  2020年   312篇
  2019年   583篇
  2018年   22406篇
  2017年   17715篇
  2016年   19893篇
  2015年   1443篇
  2014年   1494篇
  2013年   1786篇
  2012年   8335篇
  2011年   22343篇
  2010年   19447篇
  2009年   12159篇
  2008年   20549篇
  2007年   22731篇
  2006年   1608篇
  2005年   3233篇
  2004年   4387篇
  2003年   5192篇
  2002年   3289篇
  2001年   957篇
  2000年   1132篇
  1999年   752篇
  1998年   448篇
  1997年   422篇
  1996年   298篇
  1995年   308篇
  1994年   270篇
  1993年   243篇
  1992年   506篇
  1991年   558篇
  1990年   579篇
  1989年   532篇
  1988年   449篇
  1987年   485篇
  1986年   391篇
  1985年   413篇
  1984年   326篇
  1983年   311篇
  1982年   195篇
  1981年   175篇
  1980年   206篇
  1979年   296篇
  1978年   249篇
  1976年   183篇
  1975年   177篇
  1974年   212篇
  1973年   193篇
  1972年   186篇
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
41.
Relationship-centered care reflects both knowing and feeling: the knowledge that physician and patient bring from their respective domains of expertise, and the physician’s and patient’s experience, expression, and perception of emotions during the medical encounter. These processes are conveyed and reciprocated in the care process through verbal and nonverbal communication. We suggest that the emotional context of care is especially related to nonverbal communication and that emotion-related communication skills, including sending and receiving nonverbal messages and emotional self-awareness, are critical elements of high-quality care. Although nonverbal behavior has received far less study than other care processes, the current review argues that it holds significance for the therapeutic relationship and influences important outcomes including satisfaction, adherence, and clinical outcomes of care.  相似文献   
42.
Coronary flow reserve (CFR) has been used toassess coronary microcirculation and epicardial coro-nary stenoses[1— 3 ] . CFR is defined as the ratio ofcoronary flow under maximal coronary vasodilatationto coronary flow under resting conditions[4 ] .Whenthe cross- sectional area of epicardial coronary arteriesis constant,coronary flow velocity (CFV) ratios areequal to volume flow ratios.The most common method used clinically formeasuring CFVR is intracoronary Doppler flow(ICD) analysis re…  相似文献   
43.
44.
45.
Diarrhetic shellfish poisoning (DSP) is a serious and globally widespread phytoplankton-related seafood illness. Although DSP is rarely life-threatening, it causes incapacitating diarrhea and vomiting with no known medical treatments. In addition, phytoplankton producing DSP toxins have been identified in temperate coastal waters worldwide, and their numbers may be increasing as a result of coastal eutrophication. The toxic effects of the major DSP toxins, okadaic acid and dinophysistoxin-1 (35-methylokadaic acid), appear to originate from their inhibitory activity against a family of structurally related serine/threonine protein phosphatases (PSPases). In particular, the inhibition of essential PSPases (e.g. PP1 and PP2A) has catastrophic consequences in most eukaryotic cells. Exploiting the potent inhibitory property of the DSP toxins, we have developed an enzyme-based assay (PP2A assay) capable of detecting both okadaic acid and dinophysis- toxin-1 in nanogram amounts. The assay employs purified PP2A, which has an extremely high affinity for both DSP toxins. This provides the PP2A assay with a level of sensitivity comparable to, or surpassing, that of most monoclonal antibody probes. To evaluate the PP2A assay as a means of detecting contaminated shellfish, a series of spike recovery experiments was conducted. The findings from these studies suggest that the PP2A assay has the potential for development into a rapid and relatively simple method for detecting PSPase inhibitors in crude extracts produced from shellfish.  相似文献   
46.
47.
A retrospective analysis of the results of 27,801 cervical smears from one year in a community laboratory was undertaken. This represented 23,820 individual patients. Abnormalities were seen in 9.3% of patients. Three point seven percent of patients had benign abnormalities, 5.5% had cervical intraepithelial neoplasia and 0.1% had major abnormalities. The incidence of cervical epithelial abnormality was highest in the 15-34 age group but major abnormalities were seen most often in the 55+ age group. Human papillomavirus was more commonly seen in the youngest age group. The presence of inflammation was reported in 65% of the smears. Thirty percent of smears had no endocervical cells and 0.6% were grossly inadequate. Fifteen percent of patients had repeat smears and 3% of total smears were judged unnecessary. Forty two point six percent of patients less than 55 years of age in the laboratory population base had a smear but only 7.9% of those over 55.  相似文献   
48.
Four tricyclic antidepressants, amitriptyline, imipramine, desipramine and iprindole have been shown to partially protect mouse brain monoamine oxidase in-vivo from the irreversible enzyme inhibition produced by subsequent injection of phenelzine. Levels of protection were similar when the enzyme was assayed with selective substrates (5-hydroxytryptamine and phenethylamine) for both the A and B forms of the enzyme. Although other explanations cannot at this stage be ruled out, these observations are consistent with the tricyclic antidepressants acting as reversible inhibitors of brain monoamine oxidase in-vivo.  相似文献   
49.
50.
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