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   72480篇
  免费   6975篇
  国内免费   2460篇
耳鼻咽喉   158篇
儿科学   793篇
妇产科学   2030篇
基础医学   3514篇
口腔科学   579篇
临床医学   6671篇
内科学   7617篇
皮肤病学   1141篇
神经病学   2261篇
特种医学   726篇
外国民族医学   7篇
外科学   2601篇
综合类   9024篇
现状与发展   9篇
一般理论   4篇
预防医学   4959篇
眼科学   720篇
药学   32012篇
  47篇
中国医学   3109篇
肿瘤学   3933篇
  2024年   160篇
  2023年   1189篇
  2022年   1582篇
  2021年   2622篇
  2020年   2655篇
  2019年   2661篇
  2018年   2754篇
  2017年   2999篇
  2016年   2852篇
  2015年   2905篇
  2014年   4828篇
  2013年   8344篇
  2012年   4688篇
  2011年   4932篇
  2010年   3850篇
  2009年   3633篇
  2008年   3380篇
  2007年   3344篇
  2006年   3000篇
  2005年   2692篇
  2004年   2311篇
  2003年   2023篇
  2002年   1555篇
  2001年   1447篇
  2000年   1163篇
  1999年   977篇
  1998年   866篇
  1997年   801篇
  1996年   653篇
  1995年   615篇
  1994年   525篇
  1993年   459篇
  1992年   513篇
  1991年   416篇
  1990年   345篇
  1989年   279篇
  1988年   265篇
  1987年   252篇
  1986年   211篇
  1985年   222篇
  1984年   175篇
  1983年   143篇
  1982年   118篇
  1981年   92篇
  1980年   64篇
  1979年   64篇
  1978年   72篇
  1977年   49篇
  1976年   48篇
  1975年   50篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
目的探讨一对一责任助产加笑气吸入对分娩镇痛的疗效。 方法将576例产妇随机分为观察组和对照组.每组288例,两组均采用一对一责任助产及其他产科处理措施,观察组同时给予笑气吸入.观察两组的产痛程度、产程时间、分娩方式、笑气对新生儿的影响、产后出血及尿潴留等。 结果观察组无痛分娩率达95.8%.而对照组则为0(P〈0.01),观察组的产程时间短于对照组(P〈0.01)。 结论笑气吸入分娩镇痛产程时间短,对母婴均无不良影响,加一对一责任助产.是一种理想的分娩方法,值得产科临床推广使用。  相似文献   
92.
The aim of this study was to assess the impact of delivery on the pelvic floor and whether cesarean section (C/S) can prevent pelvic floor injury. Five hundred thirty nine women were divided into three groups according to the delivery method adopted: elective C/S, emergent C/S, and vaginal delivery. A urinary incontinence questionnaire survey was conducted around 1 year postpartum. Emergent C/S may be a major risk factor for postpartum urinary incontinence and interfere with the benefit of elective C/S for preventing pelvic floor injury. Hence, not all C/S deliveries can reduce the likelihood of postpartum urinary incontinence. The key lies in whether the C/S is performed before labor.  相似文献   
93.
2003~2005年我院抗组胺药用药分析   总被引:1,自引:0,他引:1  
沈斌  夏永华  方子正 《安徽医药》2006,10(7):539-540
目的了解抗组胺药在该院的应用情况和发展趋势。方法调查该院2003~2005年抗组胺药使用品种、年销售量,采用金额排序、用药频度及日均费用进行统计、分析。结果抗组胺药品种变化不大,但使用有集中现象,用药金额2004年有所下降,目前最常用的是酮替芬、西替利嗪、羟嗪和氯雷他定等。结论国内制药企业应加大科研力度,多研制开发出长效、安全、经济的抗组胺药,以满足患者需求。  相似文献   
94.
95.
Background and Aim:  We recently reported that cyclooxygenase (COX)-2 is upregulated in the rat small intestine after administration of indomethacin, and this may be the key to non-steroidal anti-inflammatory drug (NSAID)-induced intestinal damage. The present study investigated the mechanism for COX-2 expression induced in the rat small intestine by indomethacin, in relation with ulcerogenic processes.
Methods:  Animals were given indomethacin or SC-560 p.o., and the intestinal mucosa was examined 24 h later.
Results:  Indomethacin caused hemorrhagic lesions in the small intestine, accompanied with an increase in intestinal motility, bacterial invasion and inducible nitric oxide synthase (iNOS) activity, as well as the expression of COX-2 mRNA in the mucosa. Although SC-560 did not cause any damage, this agent caused intestinal hypermotility, the bacterial invasion and the upregulation of COX-2 expression. The mucosal PGE2 content was decreased by SC-560 at 3 h but recovered 12 h later, and this recovery of PGE2 was attenuated by both atropine and ampicillin, in addition to rofecoxib. The intestinal hypermotility response to indomethacin was prevented by both 16,16-dimethyl PGE2 and atropine, but not ampicillin. Yet all these agents inhibited not only the bacterial invasion but also the expression of COX-2 and iNOS activity in the intestinal mucosa following indomethacin treatment, resulting in the prevention of intestinal lesions.
Conclusion:  These results suggest that COX-2 expression in the intestinal mucosa following the administration of indomethacin is associated with intestinal hypermotility and bacterial invasion. The intestinal hypermotility caused by COX-1 inhibition may be a key to COX-2 expression after administration of NSAIDs and their intestinal ulcerogenic properties.  相似文献   
96.
The incidence of wound botulism is increasing and the epidemiology of the disease is changing. The majority of new cases are associated with injection drug use, in particular, the use of Mexican black tar heroin. This case report and discussion of wound botulism illustrate the following important points: Dysphagia, dysphonia, diplopia, and descending paralysis, in association with injection drug use, should alert the treating physician to the possibility of wound botulism. In such patients, the onset of respiratory failure may be sudden and without clinically obvious signs of respiratory weakness. For the reported patient, maximum inspiratory force measurements were the only reliable indicator of respiratory muscle weakness. This is a measurement not routinely performed in the ED, but may prove essential for patients with suspected wound botulism. To minimize the effect of the botulinum toxin and to decrease length of hospital stay, antitoxin administration and surgical wound debridement should be performed early.  相似文献   
97.
药物传递系统(DDS)Ⅳ腔道给药传递系统   总被引:2,自引:0,他引:2  
腔道给药是能起全身作用、避开肝首过代谢作用、患者便于自用的非损伤性给药途径。本文着重介绍影响鼻腔、阴道给药药物吸收的生物因素和剂型因素及正在开发的腔道给药传递系统。  相似文献   
98.
Summary A randomised crossover study was performed in subjects with rheumatoid arthritis (or other arthropathies) to investigate if any alteration in the steady pharmacokinetics of the NSAID piroxicam (a drug which is extensively metabolised via cytochrome P450) or its major metabolites occurred as a result of coadministering either cimetidine or nizatidine.Twelve females and 2 males with mean age, weight, and albumin concentrations of 58 years, 61 kg, and 40 g·L–1 respectively, completed the study. Comparisons were made between the following parameters: plasma piroxicam AUCs [AUC0-24(P)], plasma 5-hydroxypiroxicam AUCs [AUC0-24(5-OHP)], the ratio of these i.e. AUC0-24(5-OHP):AUC0-24(p), the % piroxicam daily dose excreted in urine as 5-hydroxypiroxicam (before and after glucuronidase incubation); and the mean of the steady state trough piroxicam, and 5-hydroxypiroxicam concentrations (obtained during each study phase in addition to the wash-out period).A statistically significant difference as a result of initiating either cimetidine or nizatidine was obtained only for the ratio AUC0-23(5-OHP):AUC0-24(P). This was indicative of a weak potential to inhibit piroxicam hydroxylation.No clinically significant alteration in the steady state pharmacokinetics of piroxicam occurred in these subjects as a result of cimetidine or nizatidine coadministration. Consequently it is unlikely that any adverse events would arise from these combinations.  相似文献   
99.
With the advent of genomics, combinatorial paradigms and high-throughput screen (HTS)-based pharmacological testing, the number of compounds flowing through the discovery pipeline is likely to escalate. At the same time, with increased knowledge of the human drug-metabolizing enzymes and the availability of in vitro absorption-metabolism (AM) models, Preclinical Drug Metabolism is poised to meet the challenges of HTS. In order to be successful, however, a rational HTS strategy (vs. serendipitous HTS) has to be employed. Such a strategy is based on automation, validation and integration of in vitroAM models and database management (AVID). A generalized strategy for rational (AVID-based) HTS in Preclinical Drug Metabolism is described briefly.  相似文献   
100.
The application of a circular dichroism (c.d.) detection system in HPLC using a chiral stationary phase is presented. The simultaneous measurement of the absorbance and c.d. signal allows the evaluation of the anisotropy factor (g = Δ/) and thus the determination of the enantiomeric excess (e.e.) of the eluates. When this detection system is used in preparative chiral chromatography the collection of the enantiomeric fractions can be readily optimized.  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