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   59476篇
  免费   5560篇
  国内免费   4026篇
耳鼻咽喉   488篇
儿科学   1146篇
妇产科学   609篇
基础医学   5577篇
口腔科学   935篇
临床医学   8181篇
内科学   7520篇
皮肤病学   637篇
神经病学   2406篇
特种医学   1943篇
外国民族医学   26篇
外科学   4691篇
综合类   12552篇
现状与发展   6篇
一般理论   7篇
预防医学   5370篇
眼科学   1294篇
药学   7411篇
  52篇
中国医学   4306篇
肿瘤学   3905篇
  2024年   209篇
  2023年   761篇
  2022年   2179篇
  2021年   2719篇
  2020年   2262篇
  2019年   1673篇
  2018年   1779篇
  2017年   1852篇
  2016年   1697篇
  2015年   2743篇
  2014年   3451篇
  2013年   3375篇
  2012年   5188篇
  2011年   5644篇
  2010年   4226篇
  2009年   3501篇
  2008年   3970篇
  2007年   3659篇
  2006年   3377篇
  2005年   3006篇
  2004年   2046篇
  2003年   1768篇
  2002年   1369篇
  2001年   1072篇
  2000年   962篇
  1999年   920篇
  1998年   522篇
  1997年   553篇
  1996年   383篇
  1995年   326篇
  1994年   272篇
  1993年   188篇
  1992年   222篇
  1991年   189篇
  1990年   152篇
  1989年   147篇
  1988年   108篇
  1987年   136篇
  1986年   88篇
  1985年   74篇
  1984年   59篇
  1983年   32篇
  1982年   26篇
  1981年   32篇
  1980年   23篇
  1979年   19篇
  1978年   25篇
  1977年   16篇
  1976年   12篇
  1974年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Recent clinical trials with rapamycin-eluting stents have shown very low restenosis rates.1-4 However, the higher penetration of drug eluting stent (DES) in China is being limited by the high costs of these imported devices, especially when considering multiple stenting.  相似文献   
102.
目的探讨前列腺增生症患者早期行盆底肌锻炼防治经尿道前列腺汽化电切(TUVP)术后暂时性尿失禁和缩短尿失禁持续时间的效果,方法对89例前列腺增生症患者需行TUVP术病例随机分为实验组和对照组。对照组常规在术后拔尿管前1~2d夹闭尿管,定期开放。实验组于明确诊断开始,术后留置尿管期间及拔除尿管后均指导病人进行盆底肌锻炼。比较两组术后尿失禁发生率,尿失禁持续时间。结果实验组术后尿失禁1例,发生率为2.2%,尿失禁持续时间为2d,对照组术后尿失禁11例,发生率25%,尿失禁持续时间7~12d,两组比较,差异有显著性,p<0.01。结论早期行盆底肌锻炼能有效地预防和降低术后尿失禁发生率,缩短尿失禁持续时间。  相似文献   
103.
Fang M  Wang Y  Liu HX  Liu XS  Han JS 《Neuroreport》2000,11(4):737-741
It is now well established that nerve growth factor (NGF) plays a key role in inflammation-induced hyperalgesia. It was also reported that brain derived neurotrophic factor (BDNF), another member of neurotrophins, contributed to the pain pathway as a neurotransmitter in the CNS. The present work demonstrated a down-regulation of glial cell line-derived neurotrophic factor (GDNF) mRNA expression in dorsal spinal cord in complete Freund's adjuvant-induced unilateral arthritic rats serving as a chronic pain model. The fast occurring and long lasting down-regulations suggest that GDNF might contribute to pain pathway in a way different from neurotrophins and might play a role in the maintenance of chronic pain status.  相似文献   
104.
目的:寻求一种鉴定天花粉与其混淆品长萼瓜蒌的有效方法。方法:采用天花粉双边栝楼根以及瓜氨酸作为对照物质,与长萼瓜蒌根同时进行紫外光谱扫描。结果:紫外光谱显示,长萼瓜蒌的水和乙醇溶液在272nm波长处均有最大吸收,而天花粉及瓜氯酸均无此光谱特征,可资鉴别。结论:用紫外光谱法鉴定天花粉与长萼瓜蒌,方法简便可行,结果准确可靠。  相似文献   
105.
林芳 《福建中医药》2005,36(1):28-29
慢性咳嗽是指患者连续咳嗽3周以上,临床上使用过抗生素及止咳祛痰药疗效不显著者。近几年来笔者采用拔罐加TDP治疗慢性咳嗽,疗效较为满意,现报道如下。  相似文献   
106.
研究了电致孔技术对睾酮透皮转运的影响,对电压、脉冲持续时间和电极的影响进行了初步探讨.结果表明,电致孔可增大药物的透皮转运速率及其累积透过量,且电力学参数与透皮吸收增量呈正相关,电极也明显影响电致孔透皮速率.  相似文献   
107.
目的 :观察阳离子脂质体 (DOTAP DOPE)介导的 β1肾上腺素能受体mRNA反义寡核苷酸 (β1 AS ODN)对肾性高血压大鼠血流动力学及心肌肥厚的影响。方法 :建立二肾一夹 (2K1C)肾性高血压大鼠模型 ,随机分为假手术组、模型组、反向寡核苷酸组、反义寡核苷酸组和卡维地洛 (carvedilol)组。ODN与DOTAP DOPE以 1 2摩尔比混合 ,4周末尾静脉注射 0 .5mg·kg-1,卡维地洛 10mg·kg-1·d-1灌胃 4周。定期测血压 ,8周末测血流动力学参数 ,左室重量指数 (LVWI)及血浆内皮素 1(ET 1)浓度 ,并对LVWI与ET 1进行线性相关分析。结果 :与反向寡核苷酸组比 ,β1 AS ODN能降低血压最高达39mmHg并持续 2 7d(30 .4 4± 6 .5 0 ,P <0 .0 1) ,降低左室收缩压 (LVSP) (P <0 .0 5 )、左室舒张末压 (LV EDP) (P <0 .0 1) ,升高左室最大收缩和舒张速率 (±dp dtmax) (P <0 .0 1) ,降低LVWI(P <0 .0 5 )及血浆ET 1(P <0 .0 1) ;与卡维地洛组比 ,各指标均无显著性差异。LVWI与ET 1显著正相关 (r =0 .74 9,P <0 .0 1)。结论 :DOTAP DOPE介导的 β1 AS ODN单剂量静脉注射能持续降压 ,改善血流动力学 ,预防心肌肥厚 ,可能与其降低血浆ET 1有关。  相似文献   
108.
As more high tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are performed, orthopaedic surgeons realize that more HTO and UKA failures will require revision to total knee arthroplasty (TKA) in the future. To systematically evaluate the clinical outcomes of TKA after HTO and TKA after UKA, the Embase, PubMed, Ovid, Web of Science, and Cochrane Library databases were searched for studies investigating revision TKA after HTO and UKA published up to June 2021. RevMan version 5.3 was used to perform the meta‐analysis. The revision TKA after HTO and revision TKA after UKA groups were compared in terms of operative time, range of motion (ROM), knee score, postoperative complications, postoperative infection, revision, and revision implants used. Nine studies were ultimately included in the meta‐analysis. Results revealed that the knee score for the revision TKA after HTO group was better than that of the revision TKA after UKA group (MD 4.50 [95% CI 0.80–8.20]; p = 0.02). The revision TKA after HTO group had a lower revision rate (OR 0.65 [95% CI 0.55–0.78]; p < 0.00001) and fewer revision implants used (OR 0.11 [95% CI 0.05–0.23]; p < 0.00001). There were no statistical differences in operation time (MD ‐2.00 [95% CI −11.22 to 7.21]; p = 0.67), ROM (MD ‐0.04 [95% CI ‐3.69–3.61]; p = 0.98), postoperative complications (OR 1.41 [95% CI 0.77–2.60]; p = 0.27), or postoperative infections (OR 0.89 [95% CI 0.61–1.29]; p = 0.53). To conclude, the revision rate of revision TKA after UKA was greater, and more revision implants were required. It is important for orthopaedic surgeons to preserve bone during primary UKA.  相似文献   
109.
目的 建立稳定高表达增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)或突变体PC-NA(mutant PCNA,mPCNA)目的蛋白的宫颈癌细胞系HeLa细胞,观察PCNA在顺铂诱导的DNA损伤修复中的作用.方法 采用显性负突变策略,通过构建重组人PCNA或mPCNA的真核表达质粒pCDNA3.1/V5-His A-PCNA(His-PCNA)和pCDNA31/V5-His A-mPCNA(His-mPCNA),稳定转染到HeLa细胞中,G418筛选建立稳定高表达目的蛋白的HeLa细胞系;Western印迹法检测蛋白的表达情况;MTT法测定顺铂损伤后不同细胞系的细胞存活率.结果 真核表达质粒经酶切、测序分析与实验设计完全一致;稳定建系后,Western印迹结果显示在相应位置可见清楚的目的条带;MTT结果显示稳定高表达突变体PCNA的细胞系与对照组相比,其细胞存活率呈明显下降趋势.结论 成功构建了真核表达质粒His-PCNA和His-mPC-NA;建立了稳定高表达该质粒的HeLa细胞系;稳定高表达突变体PCNA的细胞系对顺铂损伤更敏感.  相似文献   
110.
Background:The findings on the effectiveness of platelet-rich plasma, ozone, and hyaluronic acid in the treatment of osteoarthritis of the knee are controversial, and the existing original studies and meta-analyses are mostly comparisons of a single joint cavity injection method, lacking direct and indirect comparisons of different drugs in the joint cavity. The lack of direct and indirect comparisons of different drugs in the joint cavity makes it difficult to have a clearer and more comprehensive understanding of joint cavity injection methods. In this study, the efficacy of platelet-rich, ozone, sodium hyaluronate, and combined knee cavity injections were compared directly or indirectly using a reticulated meta-analysis in this field, and the efficacy of treatment measures was ranked to provide more comprehensive and reliable evidence-based clinical evidence for the selection of knee cavity injections in osteoarthritis of the knee.Objective:To compare the effects of platelet-rich plasma, ozone, and sodium glassate injection interventions on the efficacy of osteoarthritis of the knee through reticulated Meta-analysis, and to comprehensively compare the clinical effectiveness of platelet-rich plasma, ozone, and sodium glassate injection joint cavity injection for the treatment of osteoarthritis of the knee.Methods:The PubMed, CBM, CNKI, VIP, and Wan-Fang databases were searched for information on the effectiveness of platelet-rich plasma, ozone, and sodium vitrate injection for the comparative treatment of osteoarthritis of the knee, with a search time frame of each database from the date of creation to July 20, 2021. Two investigators independently screened the literature, extracted data according to inclusion and exclusion criteria, and evaluated the quality of the literature in parallel. Statistical analysis was performed using Stata 16.0 software to compare the differences in the efficacy of each treatment measure using the ratio and 95% confidence interval as effect indicators and to rank the efficacy.Results:Thirty-three RCTs with 7003 patients with osteoarthritis of the knee were included, involving 5 therapeutic measures. Meta-analysis showed that the efficacy of platelet-rich plasma injection was superior to both ozone and hyaluronic acid therapies. Hyaluronic acid+ozone and platelet-rich plasma+hyaluronic acid were both superior to ozone and hyaluronic acid monotherapy. The differences in efficacy between hyaluronic acid and ozone compared with platelet-rich plasma were statistically significant, and the differences in efficacy between the 2 combination therapies (platelet-rich plasma+hyaluronic acid, hyaluronic acid+ozone) and the 3 monotherapies (platelet-rich plasma, ozone, hyaluronic acid) were statistically significant. Platelet-rich plasma+hyaluronic acid, hyaluronic acid+ozone compared with 3 monotherapies (platelet-rich plasma, ozone, hyaluronic acid) were statistically significant, except for the difference in efficacy with platelet-rich plasma, which was not statistically significant, indicating that this platelet-rich plasma+hyaluronic acid and Hyaluronic acid+ozone combination therapy was superior to monotherapy. Also, the efficacy of platelet-rich plasma was better than hyaluronic acid and ozone and the difference was statistically significant, indicating that platelet-rich plasma was more effective than ozone and sodium glass in the treatment of osteoarthritis of the knee in monotherapy.Conclusion:It is believed that in the course of clinical practice, hyaluronic acid+ozone or platelet-rich plasma+hyaluronic acid combination therapy or platelet-rich plasma therapy can be preferred for patients with osteoarthritis of the knee.  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