全文获取类型
收费全文 | 44980篇 |
免费 | 4937篇 |
国内免费 | 56篇 |
专业分类
耳鼻咽喉 | 632篇 |
儿科学 | 1256篇 |
妇产科学 | 1258篇 |
基础医学 | 6993篇 |
口腔科学 | 1050篇 |
临床医学 | 6079篇 |
内科学 | 8348篇 |
皮肤病学 | 593篇 |
神经病学 | 3624篇 |
特种医学 | 1460篇 |
外国民族医学 | 1篇 |
外科学 | 6028篇 |
综合类 | 907篇 |
一般理论 | 29篇 |
预防医学 | 4671篇 |
眼科学 | 675篇 |
药学 | 3628篇 |
中国医学 | 61篇 |
肿瘤学 | 2680篇 |
出版年
2021年 | 615篇 |
2020年 | 406篇 |
2019年 | 698篇 |
2018年 | 801篇 |
2017年 | 576篇 |
2016年 | 718篇 |
2015年 | 752篇 |
2014年 | 1031篇 |
2013年 | 1573篇 |
2012年 | 2101篇 |
2011年 | 2161篇 |
2010年 | 1212篇 |
2009年 | 1082篇 |
2008年 | 1884篇 |
2007年 | 1953篇 |
2006年 | 1913篇 |
2005年 | 1872篇 |
2004年 | 1793篇 |
2003年 | 1742篇 |
2002年 | 1770篇 |
2001年 | 1559篇 |
2000年 | 1591篇 |
1999年 | 1376篇 |
1998年 | 610篇 |
1997年 | 506篇 |
1996年 | 428篇 |
1995年 | 467篇 |
1994年 | 436篇 |
1993年 | 404篇 |
1992年 | 1117篇 |
1991年 | 1051篇 |
1990年 | 1031篇 |
1989年 | 948篇 |
1988年 | 872篇 |
1987年 | 899篇 |
1986年 | 866篇 |
1985年 | 885篇 |
1984年 | 704篇 |
1983年 | 601篇 |
1982年 | 427篇 |
1981年 | 348篇 |
1980年 | 361篇 |
1979年 | 578篇 |
1978年 | 440篇 |
1977年 | 361篇 |
1976年 | 368篇 |
1974年 | 379篇 |
1973年 | 333篇 |
1972年 | 338篇 |
1971年 | 304篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
If there was to be an award for the most readable digest ofall medical matters relating to running marathons, then DanTunstall-Pedoes latest volume must surely stand a winningchance. The contents are based on discussions 相似文献
82.
Jones DL Weiss SM Chitalu N Villar O Kumar M Bwalya V Mumbi M 《American journal of infectious diseases》2007,3(4):169-176
An estimated 38.6 million persons globally are living with HIV, of whom over 1.1 million reside in Zambia. Of the 2 million cases in the US, 64% of new cases among women are among African Americans. Alcohol and drug use represents a significant risk factor for HIV transmission among both Zambians and African Americans. In addition, gender dynamics in both the US and Zambia promote transmission. This study examines two interventions targeting HIV risk behavior among HIV positive substance users, women in Miami, USA (the New Opportunities for Women (NOW) Project) and men in Lusaka, Zambia (the Partner Project). The study compares the efficacy of these two culturally tailored sexual behavior interventions provided in group and individual session formats. US and Zambian participants increased sexual barrier use and reduced substance-related sexual risk. Comparatively greater gains were made by higher risk Zambian males than US females in both group and individual conditions. Among lower risk participants, women in the group condition achieved and sustained the greatest comparative risk reductions. Results suggest that cost effective group HIV transmission risk reduction interventions for multiethnic individuals can be successfully implemented among both female and male drug and alcohol users in multinational settings. 相似文献
83.
Vulvar leiomyomatosis in a patient with esophagogastric leiomyomatosis: review of the syndrome 总被引:2,自引:0,他引:2
A case of vulvar leiomyomatosis in a young adult with a history of esophagogastrectomy as a child for esophagogastric leiomyomatosis is presented. The steroid receptor profile of the tumor is described. Therapy with a combination of gonadotropin suppression and surgery was undertaken. The literature pertaining to this rare combination is discussed. 相似文献
84.
85.
Priscilla LeMone DSN RN Donna Jones MPH RN 《International journal of nursing terminologies and classifications》1997,8(3):120-128
TOPIC. Nursing assessment of altered sexuality.
PURPOSE. To review salient factors affecting assessment and objective measures available for use in assessment.
SOURCE. Literature specific to nursing assessment of sexuality and to instruments measuring altered sexuality.
CONCLUSIONS. Many standards of care include the assessment of sexuality, and nurses believe it to be an important aspect of care. However, the assessment of altered sexuality does not often occur in actual practice. The use of an objective measure of sexuality is recommended for both initial and on-going assessments in acute-care and community-based settings. 相似文献
PURPOSE. To review salient factors affecting assessment and objective measures available for use in assessment.
SOURCE. Literature specific to nursing assessment of sexuality and to instruments measuring altered sexuality.
CONCLUSIONS. Many standards of care include the assessment of sexuality, and nurses believe it to be an important aspect of care. However, the assessment of altered sexuality does not often occur in actual practice. The use of an objective measure of sexuality is recommended for both initial and on-going assessments in acute-care and community-based settings. 相似文献
86.
We investigated the regulation of the rat neuron-specific enolase gene using a transient transfection approach. Recent transgenic
mouse studies have shown that a 1.8-kb segment of the ratNSE gene 5′ flanking region, including the first (noncoding) exon but not the first intron, is able to drive expression of a
reporter gene in parallel with endogenousNSE. These data suggest thatcis-acting elements responsible for the spatial and temporal pattern ofNSE gene expression are located within the proximal 1.8 kb of the 5′ flanking sequence. To further investigate this region, we
joined the 1.8-kb regulatory cassette to thecat reporter gene and generated a number of constructs in which the flanking sequence was progressively deleted from the 5′ end.
These constructs were tested by transient transfection into neuronal and nonneuronal cells, followed by an assay for CAT activity.
We found that as little as 255 bp of 5′ flanking sequence was able to confer cell type-specificity on the reporter gene. Further
truncation to 120 bp of 5′ sequence resulted in a sharp downregulation of reporter activity in PC12 cells but a significant
rise in both Neuro-2A neuroblastoma cells and nonneuronal Ltk- cells, indicating thatcis-acting elements controlling the regulation ofNSE in Ltk-, Neuro-2A, and PC12 cells may lie within the 135 bp region covered by this deletion. This region contains an AP-2
site and an element similar in sequence and position to a motif identified in the proximal promoter region of the neuron-specific
peripherin gene. Reduction to 95 bp of 5′ sequence resulted in a slight downregulation of CAT activity in all cell lines tested,
and further truncation to 65 bp of 5′ sequence caused a universal reduction to background levels of CAT activity, concomitant
with the disruption of the basalNSE promoter. Our results show that the 5′ flanking region of theNSE gene is capable of conferring cell type-specificity on a heterologous gene in transfected cells and that elements responsible
for this are located within the proximal 255 bp. 相似文献
87.
Summary: A case of 4 true knots in an umbilical cord, which did not cause any detectable harm, is presented. Careful examination of the placenta, membranes and umbilical cord continues to be encouraged. 相似文献
88.
We describe a simple, quick ultrasound screening test for CDH, and its use in a prospective study of babies with a 'high risk' factor, over one year from January 1987. From a birth population of 3,879, 812 hip scans were performed on 406 babies and 98 babies were abnormal. So far, there have been no late cases of CDH. Family history, breech malposition, and postural foot deformities were confirmed to be important risk factors, but babies with a simple click were equally at risk. Our early results indicate that a large proportion of the potential late cases are contained within our extended high-risk group. 相似文献
89.
This study evaluated the changes in renal function that occur during the early phases of chronic infusion of carbachol into the lateral ventricle in conscious rats. Infusion of 1.0 micrograms/h of carbachol i.c.v. resulted in a prompt pressor response with mean arterial pressure rising 20 mm Hg within 15 min. The pressure remained elevated for the duration of a 2-hour infusion. Carbachol infusion at 0.5 micrograms/h induced a similar elevation in blood pressure, but the onset was delayed, reaching significance only after 30-60 min. The higher dose of carbachol was associated with a marked and sustained natriuresis, with sodium excretion increasing from 2.1 +/- 0.3 to 5.3 +/- 1.0 microEq/100 g min after 2 h, compared to 2.0 +/- 0.5 and 1.8 +/- 0.3 microEq/100 g min in vehicle-infused control animals. Sodium excretion did not change significantly in animals infused with carbachol at 0.5 microgram/h. There were no significant changes in glomerular filtration rate in any of the groups. Plasma levels of atrial natriuretic peptide (ANP) were not altered significantly by ventricular infusion of carbachol (188 +/- 99 before vs. 83 +/- 17 pg/ml after infusion). It is concluded that the pressor response to central carbachol infusion is not dependent on retention of sodium and water. The natriuresis observed with carbachol infusion can be dissociated from the pressor response, and is not mediated by ANP. 相似文献
90.