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   6708篇
  免费   851篇
  国内免费   200篇
耳鼻咽喉   63篇
儿科学   44篇
妇产科学   116篇
基础医学   713篇
口腔科学   177篇
临床医学   471篇
内科学   762篇
皮肤病学   130篇
神经病学   335篇
特种医学   83篇
外国民族医学   1篇
外科学   1114篇
综合类   488篇
预防医学   798篇
眼科学   33篇
药学   1609篇
  2篇
中国医学   521篇
肿瘤学   299篇
  2024年   84篇
  2023年   331篇
  2022年   525篇
  2021年   455篇
  2020年   422篇
  2019年   348篇
  2018年   323篇
  2017年   307篇
  2016年   272篇
  2015年   325篇
  2014年   463篇
  2013年   517篇
  2012年   361篇
  2011年   368篇
  2010年   271篇
  2009年   246篇
  2008年   222篇
  2007年   202篇
  2006年   179篇
  2005年   165篇
  2004年   141篇
  2003年   121篇
  2002年   116篇
  2001年   84篇
  2000年   91篇
  1999年   78篇
  1998年   86篇
  1997年   77篇
  1996年   58篇
  1995年   68篇
  1994年   42篇
  1993年   41篇
  1992年   39篇
  1991年   31篇
  1990年   30篇
  1989年   29篇
  1988年   31篇
  1987年   33篇
  1986年   42篇
  1985年   34篇
  1984年   21篇
  1983年   13篇
  1982年   16篇
  1981年   17篇
  1980年   9篇
  1979年   9篇
  1978年   6篇
  1977年   5篇
  1974年   2篇
  1972年   2篇
排序方式: 共有7759条查询结果,搜索用时 10 毫秒
51.
Antibiotic prophylaxis in surgery is one of the most effective measures for preventing surgical site infection, although its use is frequently inadequate and may even increase the risk of infection, toxicities and antimicrobial resistance. As a result of advances in surgical techniques and the emergence of multidrug-resistant organisms, the current guidelines for prophylaxis need to be revised.The Sociedad Española de Enfermedades Infecciosas (Spanish Society of Infectious Diseases and Clinical Microbiology) (SEIMC) together with the Asociación Española de Cirujanos (Spanish Association of Surgeons) (AEC) have revised and updated the recommendations for antibiotic prophylaxis in surgery to adapt them to any type of surgical intervention and to current epidemiology. This document gathers together the recommendations on antimicrobial prophylaxis in the various procedures, with doses, duration, prophylaxis in special patient groups, and in epidemiological settings of multidrug resistance to facilitate standardized management and the safe, effective and rational use of antibiotics in elective surgery.  相似文献   
52.
53.
《Neuro-Chirurgie》2021,67(2):152-156
IntroductionComplex spinal surgery is known to be at risk of complications. Surgical site infection is a serious complication in spine surgery and its frequency is significantly increased in adult spinal deformity correction. The aim of this study is to identify patients’ characteristics and risk factors of surgical site infection (SSI) following an osteotomy.MethodsThis is a single-center retrospective study of patients who underwent an osteotomy between January 2015 and December 2017. Surgical site infection diagnosis was based upon patient's clinical evidence of infection, biologic parameters, microbiological criteria and/or image findings.ResultsIn total, 102 patients were eligible and 70 were women (68.6%). Mean age was 65 years old (27–83 years) and mean body mass index (BMI) was 26.14 kg.m−2 (18.4–44.1). Eleven patients were in the SSI group and 91 in the No-SSI group. The mean Schwab grade was 1.5 (1–4) in the SSI group vs. 1.4 (1–5) in the No-SSI group (P = 0.435). The mean operative time was on 201.9 minutes (67–377). Mean length of stay was 20.6 days (10–73) in the SSI group vs. 15 days (5–44) in the No-SSI group (P = 0.041). Favorable outcome was found in 10 patients (90.9%) in the SSI group.ConclusionCorrection surgery for adult spinal deformity with osteotomies carries a high risk of complications specially SSI. Identification of risk factors, prevention and medical management of SSI should be well assessed.  相似文献   
54.
吴浩  黄蓓蓓  贾志鑫  刘洁  陈奕君  肖红斌 《中草药》2023,54(5):1377-1385
目的 通过UHPLC-QTOF-MS/MS和分子对接技术阐明紫菀Aster tataricus中润肠通便作用的效应成分。方法 采用UHPLC-QTOF-MS/MS技术分析体内肠道内容物的成分,再利用SYBYL-X 2.0与Discovery Studio 4.0分子对接软件研究肠道内容物成分与M2受体、M3受体、蛋白激酶C(protein kinase C,PKC)蛋白的相互作用,明确各成分与靶标蛋白的结合强度。结果 体内肠道内容物中共鉴定出28个紫菀中的化学成分,有10个成分均可与M2受体、M3受体及PKC蛋白分子对接较好,其中astin J与3种靶标蛋白结合的平均打分值最高,这些成分均以非共价键方式与靶标蛋白结合,产生氢键、范德华力、经典作用力等相互作用。结论 紫菀中的astin J、asterin F、asterin A、异绿原酸A、异绿原酸B、异绿原酸C、绿原酸、槲皮素、山柰酚和木犀草素共10个成分可能是通过调节M受体及其下游信号通路PKC蛋白的表达发挥润肠通便的作用。  相似文献   
55.
56.
57.
A good ligand is hard to find: Automated docking methods   总被引:2,自引:0,他引:2  
Summary Many approaches have been developed for solving the docking problem: Predict the structure and binding free energy of a ligand-receptor complex given only the structures of the free ligand and receptor. We review major approaches for docking small-molecule ligands to receptors and focus on the successes and limitations of their application to drug design.  相似文献   
58.
Summary A comparative study of four skin graft donor site dressings was undertaken. This was a prospective and cross-over study of 25 consecutive patients with burns up to 40% TBSA treated with split skin grafts. Each donor site was divided into four sections and covered with different dressings in order to evaluate their effectiveness in healing, the time required for complete epithelialization, patient acceptance and any intolerance or local infection. The results showed that the occlusive hydrocolloid dressing significantly decreases (p<0.01) the mean time required for complete healing (7.45 days) compared with a semiocclusive hydrocolloid (10.29 days), a polyurethane sheet (9.4 days) and the conventional dressing (10.04 days).Presented at the IV European Burns Congress in Barcelona, Spain, September 25, 1991 (Abstract No. 117)  相似文献   
59.
The effect of tertiary basic drugs on mitochondrial MAO activity and the effect of MAO inhibitors (MAOIs) on basic drug accumulation in the isolated perfused rat lung were studied to clarify the role of MAO in drug binding to lung tissue. In the perfused lung preparation, the inhibition of MAO by basic drugs correlated well with their lipid solubilities and followed competitive kinetics. The inhibitory rank order (imipramine diphenhydramine > quinine > metoclopramide > procainamide) also correlated with their accumulation in the perfused lung. Moreover, MAOI treatment decreased the accumulation of basic drugs in the lung, and the potency of MAOIs to inhibit drug accumulation in the lung correlated with their MAO inhibitory activity. These results indicate that lung MAO has specific binding sites for basic drugs and may function as a drug reservoir.  相似文献   
60.
为了用反义寡聚DNA调控要霉素肿瘤细胞KB-A-1的多药抗性,对反义核酸的预作用位点、作用方式和硫代化类似物进行了研究。筛选得到两段对应于翻译起始区(3)和P-糖蛋白ATP结合位点(9)的20聚反义片段,发现反义核酸的使用次数对结果的检测有很大影响,采用5μmol/L5μmol/L的反义片段9连续处理4d,实现了将近50%抑制效果,而其正义和错义链在10μmol/L沈度的同样处理条件下则没有检测到  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