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   65140篇
  免费   6232篇
  国内免费   2557篇
耳鼻咽喉   138篇
儿科学   601篇
妇产科学   245篇
基础医学   2691篇
口腔科学   399篇
临床医学   5608篇
内科学   7640篇
皮肤病学   1064篇
神经病学   2268篇
特种医学   660篇
外国民族医学   7篇
外科学   1820篇
综合类   8718篇
现状与发展   5篇
一般理论   3篇
预防医学   4112篇
眼科学   663篇
药学   30233篇
  30篇
中国医学   3274篇
肿瘤学   3750篇
  2024年   235篇
  2023年   1052篇
  2022年   1651篇
  2021年   2284篇
  2020年   2350篇
  2019年   2301篇
  2018年   2366篇
  2017年   2599篇
  2016年   2444篇
  2015年   2462篇
  2014年   4312篇
  2013年   7052篇
  2012年   4413篇
  2011年   4513篇
  2010年   3659篇
  2009年   3207篇
  2008年   3031篇
  2007年   3048篇
  2006年   2729篇
  2005年   2441篇
  2004年   2066篇
  2003年   1888篇
  2002年   1447篇
  2001年   1411篇
  2000年   1096篇
  1999年   927篇
  1998年   807篇
  1997年   776篇
  1996年   606篇
  1995年   570篇
  1994年   494篇
  1993年   407篇
  1992年   474篇
  1991年   397篇
  1990年   313篇
  1989年   260篇
  1988年   255篇
  1987年   247篇
  1986年   198篇
  1985年   207篇
  1984年   171篇
  1983年   138篇
  1982年   117篇
  1981年   93篇
  1980年   64篇
  1979年   65篇
  1978年   68篇
  1977年   51篇
  1976年   50篇
  1975年   50篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
欧洲药品局(EMA)于2018年11月发布了"人用药品辅料右旋糖酐的包装说明书资料",该文件引用大量文献全面评价了右旋糖酐的安全性,特别指出含有右旋糖酐辅料的注射和吸入制剂的疫苗与药品,应在说明书中描述有关其过敏反应信息的新要求。介绍该文件的主要内容,期望对我国这类药品说明书的撰写和监管有所帮助。  相似文献   
2.
Introduction: Tamoxifen dominates the anti-estrogenic therapy in the early and metastatic breast cancer setting. Tamoxifen has a complex metabolism, being mainly metabolized by CYP2D6 into its 30–100 times more potent metabolite, endoxifen. Recently, a phase I study in which endoxifen as an orally z-endoxifen hydrochloride has been successfully evaluated.

Areas covered: the principal pharmacogenetic and non-genetic differences in the pharmacology of tamoxifen and endoxifen are evaluated. To this end, references from PubMed, Embase or Web of Science, among others, were reviewed As non-genetic factors, important differences and similarities such age, or adherence to tamoxifen therapy are comprehensively illustrated. Additionally, since CYP2D6 genotypes are considered the main limitation of tamoxifen, many studies have investigated the association between the worsened clinical outcomes in patients with non-functional CYP2D6 genotypes. In this review, an overview of the research on this field is presented. Also, a summary describing the literature about individualizing tamoxifen therapy with endoxifen concentrations and its limitations is listed.

Expert opinion: z-endoxifen hydrochloride is only investigated in the metastatic setting, still more research is required before its place in therapeutics is known. Similarly, monitoring tamoxifen efficacy based on endoxifen concentrations might not be overall recommended due to the limited evidence available.  相似文献   

3.
Abstract

This research explores how the level of consumers’ need for cognition (NFC) is associated with celebrity endorser credibility and examines its effects on advertising-related attitudes. A 3 (endorser types: actor/actress, athlete, TV personality/talent) × 2 (endorser’s gender) factorial experiment with 435 Japanese consumers was conducted. Concerning Japanese OTC drug advertising, lower NFC individuals perceived celebrity endorsers as more credible in comparison to higher NFC individuals. The main effects of NFC and endorser type on endorser credibility existed; however, no interaction between the two variables was found. The endorser type had an influence on attitudes toward ads and the advertised brand.  相似文献   
4.
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   
5.
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   
6.
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   
7.
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   
8.
Seventy patients, aged 1–20 years, were seen at Jordan University Hospital with high blood pressure (BP) over a 3-year period. BP values ranged from 140 to 230 mmHg for systolic pressure and from 90 to 130 mmHg for diastolic pressure. Essential hypertension was seen in only 6 patients (8.6%); secondary hypertension (n=64 or 91.4%) was due to renal parenchymal diseases (RPD) in 46 patients (65.7%), reno-vascular lesions in 8 (11.4%), renal transplantation in 5 (7.2%), teenage pregnancy in 4 (5.7%), and phaeochromocytoma in 1 patient (1.4%). The aetiologies of RPD were as follows: end-stage renal disease requiring dialysis in 14 patients, acute glomerulonephritis in 14, idiopathic nephrotic syndrome in 10, chronic renal insufficiency in 5, and polycystic kidney in 3 patients. Surgical cure of hypertension was achieved in 5 of the children with reno-vascular lesions and in the patient with phaeochromocytoma.  相似文献   
9.
10.
[目的]观察比较异环磷酰胺(IFO)、顺铂(DDP)、5-氟尿嘧啶(5-Fu)联合方案(IPF方案)与DDP,5-Fu(PF方案)治疗晚期复发鼻咽癌(Ⅲ-Ⅳ期)的近期疗效及毒副反应。[方法]136例均经病理证实为晚期复发鼻咽癌患者,随机分为IPF组69例,PF组67例(对照组)[结果]IPF组和PF组有效率分别为69.56%(48/69)和43.3%(29/67),两组间差异有显著性(X2=8.519,P<0.01)。中位生存期:IPF组16个月(8-34个月),PF组为6.5个月(4-21个月),两组间差异有显著性(X2=22.36,P<0.05)。毒副作用主要为骨髓抑制,Ⅲ-Ⅳ度白细胞下降率IPF组为49.4%,PF组为5.97%,两组差异有显著性(X2=29.54,P<0.01)。Ⅲ-Ⅳ度血小板下降率IPF组为29.18%,PF组为0%(X2=30.29,P<0.01);Ⅲ-Ⅳ度消化道反应两组的发生率分别为15.94%和11.94%(x2=0.234,P>0.01).且以Ⅲ度为主。[结论]以IFO为主的方案联合治疗晚期复发鼻咽癌疗效好,毒副反应能耐受,可作为一线方案。  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