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   211051篇
  免费   14978篇
  国内免费   6975篇
耳鼻咽喉   2763篇
儿科学   2886篇
妇产科学   3074篇
基础医学   30773篇
口腔科学   4529篇
临床医学   23172篇
内科学   35087篇
皮肤病学   4984篇
神经病学   14798篇
特种医学   10187篇
外国民族医学   55篇
外科学   25538篇
综合类   12629篇
现状与发展   26篇
一般理论   46篇
预防医学   12338篇
眼科学   6248篇
药学   20087篇
  69篇
中国医学   5904篇
肿瘤学   17811篇
  2024年   355篇
  2023年   2199篇
  2022年   6043篇
  2021年   8637篇
  2020年   5280篇
  2019年   5983篇
  2018年   6874篇
  2017年   5640篇
  2016年   6558篇
  2015年   9260篇
  2014年   11221篇
  2013年   11646篇
  2012年   17380篇
  2011年   17480篇
  2010年   10296篇
  2009年   8522篇
  2008年   11912篇
  2007年   11402篇
  2006年   10812篇
  2005年   10102篇
  2004年   8091篇
  2003年   7221篇
  2002年   6112篇
  2001年   5022篇
  2000年   4717篇
  1999年   4367篇
  1998年   2289篇
  1997年   2010篇
  1996年   1516篇
  1995年   1384篇
  1994年   1176篇
  1993年   841篇
  1992年   1381篇
  1991年   1242篇
  1990年   1135篇
  1989年   998篇
  1988年   854篇
  1987年   782篇
  1986年   593篇
  1985年   598篇
  1984年   399篇
  1983年   280篇
  1982年   178篇
  1981年   230篇
  1980年   158篇
  1979年   292篇
  1978年   187篇
  1976年   150篇
  1974年   170篇
  1973年   142篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
53.
Olfactory neuroblastoma is a rare, malignant neoplasm arising from the olfactory epithelium. It has an aggressive biological behavior that is characterized by local recurrence, atypical distant metastasis, and poor long-term prognosis. The incidence of cervical lymph node metastasis in olfactory neuroblastoma is variable, and treatment modalities are controversial. Moreover, few reports have been published concerning retropharyngeal lymph node metastasis from olfactory neuroblastoma. We present two cases of olfactory neuroblastoma with retropharyngeal lymph node metastasis. In addition, we provided a review of the current literature regarding olfactory neuroblastoma and retropharyngeal lymph node metastasis from olfactory neuroblastoma.  相似文献   
54.
55.
The promoting effect of the Chinese medicinal herb, Wikstroemia chamaedaphne and Tung oil extracts (WC and HHPA) on carcinoma of uterine cervix induced by HSV-2 or MCA in mice was studied. The results showed that WC and HHPA extracts were not carcinogenic themselves. After carcinogen HSV-2 and MCA treatment, WC and HHPA were added separately. The inducing rates by HSV-2 increased from 7.4% to 21.1% and 26.3%, those by MCA increased from 56.5% to 82.8% and 84.4%. There was a significant difference between the combined groups and groups with HSV-2 or MCA only. The experimental results suggest that these two kinds of extracts play a promoting effect on carcinogenesis. The relation between the carcinogenesis of uterine cervix or nasopharynx and WC or HHPA extracts is discussed.  相似文献   
56.
将动、静脉阻断法用于恒速灌流的在体山羊左肺,使其总压力降区分为动脉端、静脉端及中间段三部分。大肠杆菌内毒素主要升高肺静脉端压力降及肺毛细血管压;山莨菪碱可显著缓解内毒素所致的改变,但对正常肺血管各段压力降无明显影响。5-羟色胺主要升高肺动脉端压力降,对肺静脉端及毛细血管压无明显影响。去甲肾上腺素及组胺主要升高肺静脉端压力降及肺毛细血管压,但对肺动脉端无明显影响。去甲肾上腺素和组胺可能介导内毒素性肺动脉高压。  相似文献   
57.
58.
Chemotaxis, chemokinesis and cellular orientation were measured for unstimulated and 10(-7) n-formyl methionyl leucyl phenylalanine (F-met-leu-phe) stimulated polymorphonuclear leucocytes (PMNS) of nine patients with recent 10-80 per cent burns using a computer-assisted image analysis technique. The technique records PMN movement, as viewed with a phase-contrast microscope on videotapes, and then uses computer programs to calculate the speed and direction of up to 50 PMNS over a 5-min period. Orientation was determined visually. Cellular adherence was also measured by attachment methods. PMNS from burn patients were slower (av. speed 16.8 microns/min), responded less well to F-met-leu-phe (av. speed 20.9 microns/min, av. McCutcheon index 0.32), were less often oriented towards the chemoattractant (av. 39 per cent) and were more adherent (av. 50 per cent) than control cells (av. speed 21.8 microns/min; av. speed F-met-leu-phe 32.2 microns/min; McCutcheon index 0.61; oriented 59 per cent adherent; 16 per cent). Thus PMNS from burn patients orient less well, are significantly slower and have less directionality in response to a chemoattractant, and are more adherent suggesting activation.  相似文献   
59.
60.
Poverty influences health status, life expectancy, health behaviours, and use of health services. This study examined factors influencing the use of health-related services by people living in poverty. In the first phase, 199 impoverished users of health-related services in 2 large Canadian cities were interviewed by their peers. In the second phase, group interviews with people living in poverty (n = 52) were conducted. Data were analyzed using thematic content analysis. Diverse health-related services were used to meet basic and health needs, to maintain human contact, and to cope with life's challenges. Use of services depended on proximity, affordability, convenience, information, and providers' attitudes and behaviours. Use was impeded by inequities based on income status. To promote the health of people living in poverty, nurses and other health professionals can enhance the accessibility and quality of services, improve their interactions with people living in poverty, provide information about available programs, offer coordinated community-based services, collaborate with other sectors, and advocate for more equitable services and policies.  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