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   37602篇
  免费   3939篇
  国内免费   75篇
耳鼻咽喉   482篇
儿科学   1117篇
妇产科学   766篇
基础医学   5390篇
口腔科学   1446篇
临床医学   4284篇
内科学   7489篇
皮肤病学   450篇
神经病学   2953篇
特种医学   1413篇
外国民族医学   2篇
外科学   5012篇
综合类   955篇
一般理论   30篇
预防医学   3921篇
眼科学   1043篇
药学   2839篇
  1篇
中国医学   29篇
肿瘤学   1994篇
  2021年   535篇
  2020年   342篇
  2019年   558篇
  2018年   643篇
  2017年   488篇
  2016年   509篇
  2015年   631篇
  2014年   878篇
  2013年   1304篇
  2012年   1707篇
  2011年   1782篇
  2010年   1009篇
  2009年   1004篇
  2008年   1567篇
  2007年   1686篇
  2006年   1551篇
  2005年   1600篇
  2004年   1459篇
  2003年   1388篇
  2002年   1369篇
  2001年   1103篇
  2000年   1158篇
  1999年   1087篇
  1998年   475篇
  1997年   393篇
  1996年   450篇
  1995年   391篇
  1994年   400篇
  1993年   364篇
  1992年   867篇
  1991年   856篇
  1990年   873篇
  1989年   800篇
  1988年   756篇
  1987年   757篇
  1986年   713篇
  1985年   725篇
  1984年   536篇
  1983年   491篇
  1982年   320篇
  1981年   328篇
  1980年   300篇
  1979年   474篇
  1978年   382篇
  1977年   310篇
  1976年   294篇
  1974年   374篇
  1973年   362篇
  1972年   297篇
  1971年   311篇
排序方式: 共有10000条查询结果,搜索用时 474 毫秒
81.
In the rabbit isolated distal saphenous artery, the population of postjunctional adrenoceptors is of the alpha 1 variety under normal in vitro experimental conditions, based on the potency order of selective agonists and on the effects of the antagonists prazosin and rauwolscine against responses to UK-14304. Angiotensin II (A II, 0.05 microM) however, without affecting resting baseline tension, markedly enhanced responses to UK-14304, particularly at low concentrations. This previously unseen component of the response to UK-14304 was resistant to prazosin (0.1 microM) but susceptible to rauwolscine (1 microM). A II would therefore appear to have a permissive role for the expression of a quiescent population of postjunctional alpha 2-adrenoceptors in the rabbit distal saphenous artery.  相似文献   
82.
Release of α-melanocyte-stimulating hormone (α-MSH) synthesized in the hypothalamus is regulated by monoaminergic neuronal systems. An endogenous dopaminergic system inhibits α-MSH release (1, 2) whilst serotoninergic systems exert a biphasic effect on peptide release (3). The toxic effects of neonatal peripheral administration of monosodium glutamate on hypothalamic neurons containing proopiomelanocortin- (POMC-) derived peptides (4, 5) suggest additionally the presence of glutamate receptors on or indirectly influencing the POMC neuron. By comparison of the effect of the excitatory amino-acid agonists N-methyl-D-aspartate (NMDA), quisqualate and kainate on the release of α-MSH from superfused slices of rat hypothalamus, we have demonstrated a stimulatory glutamergic action on α-MSH release mediated through NMDA-type receptors.  相似文献   
83.
84.
85.
? Cochrane systematic reviews are conducted to identify level 1a evidence. So far the ENT group have published 24 reviews, while around 70 titles are in various stages of the review process. Only one review has been able to produce Ia evidence and the rest recommended further trials. ? The majority of otorhinolaryngology reviews are unable to identify level 1a evidence due to the paucity of high quality randomised control trials. ? This presents a challenge, therefore – to identify and discuss alternate methods of evidence gathering for future research?  相似文献   
86.
An unusual case report of a retained stingray spine foreign body in the foot is presented. The case is interesting in that the foreign body, although visualized on radiograph, was difficult to locate intraoperatively. A review of techniques for localizing foreign bodies in the foot is presented as well as a discussion on stingray injuries in general. Because of the possibility of spine breakage in a stingray puncture wound, radiographs should be considered in injuries of this type.  相似文献   
87.
With increasing numbers of cystic fibrosis (CF) patients surviving to adulthood, issues related to vocation inevitably arise and warrant specific attention. We examined the percentage of participants with CF currently working and explored risk factors for work disability among adults with CF. METHOD: We recruited 50 consecutive patients from an adult cystic fibrosis service. Demographic, employment history, illness severity indicators and CF-attributed work disability factors were evaluated. Demographic risk factors for work disability using the illness severity measures of FEV(1), S-K score, CRDQ, and recent hospitalisation as independent variables were determined. RESULTS: Factorial analysis of a disability index (DI) indicated no dependency on FEV(1) or S-K score, but dependency on quality of life indices (p<0.05), age (p<0.05) and hospital admission rate (p<0.05). Hours worked per week were dependent on quality of life (p<0.01) (mastery of disease domain), fewer hospital admissions (p<0.01) and age (p<0.05). Sixty-eight percent of the sample reported that CF resulted in significant impediments to employment. However, few had sought vocational guidance (6%). CONCLUSION: Determinants of workforce participation shows that hours worked and perceived disability are more dependent on mastery of disease, age, and time in hospital, than on clinical severity scores. Health professionals may assist productivity through career counselling or tailored programs.  相似文献   
88.
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   
89.
OBJECTIVE: To continue surveillance of hormone therapy (HT) use in an Australian population and to assess the impact of the Women's Health Initiative (WHI) and associated reports on HT use 16 months after the results of the WHI were first reported. METHODS: Data were obtained from the 2003 South Australian Health Omnibus Survey, which involves a representative, population face-to-face interview survey. Data were compared to five surveys undertaken between 1991 and 2000, which had consistent methods and quality-control procedures. A total of 907 interviews were conducted with women over 40 years in their own homes by trained health interviewers. RESULTS: In association with the timing of media reporting of the WHI, current HT use rates dropped from 28% in women over 50 years in 2000 to an estimated 10.2% in 2002. By October 2003, current use rates had returned to 18.8% in this age group. The media had been the main influence in the women's decision-making. Half of those who restarted therapy changed to another type of HT. Only 2.8% changed to an alternative/complementary therapy. CONCLUSIONS: Nearly two-thirds (64%) of those currently using HT in 2002 stopped therapy, mostly in response to the media reporting of the WHI. Nearly half of those who stopped HT in 2002 have since restarted. Media reporting greatly influences the use of hormonal therapies.  相似文献   
90.
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