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   49014篇
  免费   4093篇
  国内免费   144篇
耳鼻咽喉   462篇
儿科学   1580篇
妇产科学   990篇
基础医学   6838篇
口腔科学   589篇
临床医学   5856篇
内科学   10498篇
皮肤病学   1068篇
神经病学   4846篇
特种医学   1571篇
外国民族医学   1篇
外科学   7084篇
综合类   279篇
一般理论   41篇
预防医学   3962篇
眼科学   914篇
药学   3015篇
中国医学   123篇
肿瘤学   3534篇
  2023年   204篇
  2022年   300篇
  2021年   796篇
  2020年   626篇
  2019年   1134篇
  2018年   1422篇
  2017年   1131篇
  2016年   1143篇
  2015年   1426篇
  2014年   1681篇
  2013年   2380篇
  2012年   3364篇
  2011年   3610篇
  2010年   2014篇
  2009年   1797篇
  2008年   3142篇
  2007年   3327篇
  2006年   3210篇
  2005年   3294篇
  2004年   3218篇
  2003年   3122篇
  2002年   3104篇
  2001年   460篇
  2000年   370篇
  1999年   426篇
  1998年   460篇
  1997年   437篇
  1996年   352篇
  1995年   393篇
  1994年   313篇
  1993年   309篇
  1992年   240篇
  1991年   261篇
  1990年   228篇
  1989年   197篇
  1988年   198篇
  1987年   201篇
  1986年   203篇
  1985年   175篇
  1984年   204篇
  1983年   159篇
  1982年   213篇
  1981年   201篇
  1980年   185篇
  1979年   151篇
  1978年   137篇
  1977年   126篇
  1976年   105篇
  1974年   93篇
  1973年   92篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Laparoscopic hysterectomy   总被引:1,自引:0,他引:1  
Summary Thirty-three patients were selected for laparoscopic hysterectomy and operated on in the Department of Obstetrics, Gynecology and Reproductive Medicine of Clermont-Ferrand University Hospital. Surgical techniques included blunt dissection with scissors and bipolar coagulation to achieve hemostasis. A case was considered successful when all the uterine vessels were treated by laparoscopy. Twenty-four cases were completed laparoscopically (72.7%). None of these patients had postoperative bleeding; 22 had an uneventful postoperative recovery. Nine procedures were converted to laparotomy (27.3%), five because of a difficult or unsatisfactory hemostasis. We conclude that in selected cases, a total hysterectomy can be performed safely by experienced laparoscopists. Further technological progress is necessary to make this procedure more acceptable. Its value as compared to the others will have to be demonstrated.  相似文献   
102.
Pharmacokinetics of prednisolone in children with the nephrotic syndrome   总被引:1,自引:0,他引:1  
The aim of this study was to establish whether the criteria for the clinical effectiveness of steroids are correlated with the pharmacokinetics of prednisolone in children treated with prednisone during an attack of idiopathic nephrotic syndrome (INS). Thirteen patients with nephrosis were included. Prednisolone, prednisone and cortisol levels were measured using a specific high-performance liquid chromatography assay after an oral dose of 1 mg/kg body weight of prednisone taken at the onset of the disease. All the pharmacokinetic parameters, including the conversion of prednisone to prednisolone were similar to the data already published in children with INS. No correlation was found between the values of pharmacokinetic parameters and criteria of clinical effectiveness. Hypo-albuminaemia was significantly correlated with the area under the plasma-concentration curve but not with the elimination half-life of prednisolone. Moreover, the prednisolone elimination half-life correlated with the urinary exretion of 17-hydroxycorticosteroids achieved in the first 6h. The present study suggests that routine measurements of prednisolone kinetics do not help when assessing the treatment of children with INS.  相似文献   
103.
The aim of surgical treatment of a fixed stapes is to restore an as effective as possible impedance transfer of the ossicular chain and acoustic impedance of the annular ligament of the footplate, when it has lost elasticity, and this in order to achieve the best possible physiological vibration of the inner ear fluids.  相似文献   
104.
Hepatobiliary scintigraphy in a patient with bilhemia   总被引:1,自引:0,他引:1  
A 4-year-old child referred for acute jaundice following percutaneous needle biopsy of the liver underwent hepatobiliary scintigraphy. Although all conventional liver tests suggested preservation of hepatocyte function, the tracer uptake in the liver appeared dramatically reduced at scintigraphy and the blood pool activity did not decrease significantly until the end of the study. Visualization of the bile ducts indicated, however, that the tracer was taken up by the hepatocyte and further excreted into the biliary tree. There was no tracer pooling in the biliary tree although no bowel activity was observed, even on delayed images. The association of persistent blood pool activity, bile duct visualization without tracer pooling, and nonvisualization of the bowel was caused by a continuous recirculation of the tracer from the biliary tree into the bloodstream. The presence of a biliovenous fistula was further proven by percutaneous transhepatic cholangiography performed 24 h later. Since 1975, only 16 cases of bilhemia have been reported. To the best of our knowledge the scintigraphic pattern of this rare but lifethreatening complication has not previously been reported.  相似文献   
105.
The third reported case of pelvic gliomatosis found within foci of endometriosis is documented 16 years after the removal of a benign cystic teratoma. Grossly at laparoscopy the lesions appear as typical deep fibrotic endometriotic implants.  相似文献   
106.
双联抗血小板疗法预防缺血再发   总被引:3,自引:0,他引:3  
本文对应用双联抗血小板聚集药在预防缺血再发方面较应用单药的优势进行了探讨.动脉粥样硬化是一种隐袭性的全身性过程,可累及多处血管床,包括脑动脉、冠状动脉和周围动脉.粥样硬化斑块破裂是血小板活化、聚集和血栓形成进程中的刺激因素之一.因为该病是沿着整个脉管系统发展的,所以对有任何一种动脉粥样硬化临床表现的患者来说,其他血管床也极易受到侵犯.不同的血管病有着共同的易患危险因素.缺血性冠心病和脑血管病是美国三大常见死亡原因中的两种.阿司匹林在心肌梗死和卒中的二级预防方面的有效性已在众多的研究中得到证实.潘生丁在降低心肌梗死、卒中和血管性死亡方面并不比阿司匹林更好,但噻氯匹定和氯吡格雷却明显优于阿司匹林.目前正在进行评估联合应用抗血小板聚集药预防缺血再发的有效性的临床研究.体外试验和临床研究均支持联合应用两种机制不同的抗血小板聚集药的理论.双联应用抗血小板聚集疗法可增强对血小板聚集和血栓形成的抑制作用.联合应用抗血小板聚集药以不同的作用机制抑制血栓形成途径中的多个位点,有可能进一步改善患者远期临床转归.#在预防缺血再发方面,应用双联抗血小板聚集药较应用单药可能更具优势.  相似文献   
107.
A polymerase chain reaction (PCR) assay was developed for detection of Chlamydia trachomatis DNA. One primer set was used, from the published sequence of the common C. trachomatis plasmid. Detection of amplified sequences was carried out by agarose gel electrophoresis. Analysis of 106 clinical samples tested by cell culture and PCR showed a sensitivity of 100% when PCR was compared with cell culture.  相似文献   
108.
Summary A disease-oriented approach to the discovery of novel platinum anticancer drugs has been established through the setting up of parallel human ovarian-carcinoma cell lines and xenografts. The correlation between in vitro and in vivo antitumour activity was determined for four reference platinum agents (cisplatin, carboplatin, iproplatin and tetraplatin) in eight companion lines. Two methods of assessing antitumour effect were used in vitro (tritiated thymidine incorporation and sulforhodamine B staining) and three were applied in vivo [28-day treated/control (T/C) ratio, growth delay and specific growth delay]. In vitro, large differences in cytotoxicity across the cell lines were observed for each drug. This was also reflected in the xenografts for cisplatin and carboplatin and, to a lesser extent, for iproplatin. A correlation analysis of in vitro vs in vivo data revealed a high, statistically significant positive correlation for cisplatin and a strong positive correlation for carboplatin. However, for the two platinum(IV) drugs, the correlation was less good. In particular, tetraplatin was markedly less active in vivo (showing a general lack of activity against all of the tumour lines) than its in vitro potency against the cell lines predieted, resulting in poor correlation coefficients. These human tumour panels may be valuable for the elucidation of both cellular/molecular and corresponding in vivo pharmacological mechanisms of platinum drug resistance. Moreover, the HX/62 and SKOV-3 tumour lines, which exhibit a level of intrinsic resistance to the four reference agents both in vitro and in vivo (and which were derived from patients who had not received prior platinum therapy), represent particularly useful evaluation models for the discovery of novel broad-spectrum platinum drugs.This study was supported by grants to the Institute of Cancer Research from the Cancer Research Campaign and the Medical Research Council, the Johnson Matthey Technology Centre and Bristol Myers Squibb Oncology  相似文献   
109.
110.
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