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   69222篇
  免费   3714篇
  国内免费   2899篇
耳鼻咽喉   357篇
儿科学   342篇
妇产科学   216篇
基础医学   2151篇
口腔科学   2020篇
临床医学   7011篇
内科学   4660篇
皮肤病学   1086篇
神经病学   799篇
特种医学   1601篇
外国民族医学   31篇
外科学   3220篇
综合类   19432篇
预防医学   4002篇
眼科学   341篇
药学   17472篇
  141篇
中国医学   9330篇
肿瘤学   1623篇
  2024年   451篇
  2023年   1548篇
  2022年   1809篇
  2021年   1924篇
  2020年   1678篇
  2019年   1886篇
  2018年   1040篇
  2017年   1912篇
  2016年   2057篇
  2015年   2489篇
  2014年   3567篇
  2013年   3804篇
  2012年   4662篇
  2011年   4731篇
  2010年   4091篇
  2009年   3894篇
  2008年   4768篇
  2007年   3657篇
  2006年   3445篇
  2005年   3480篇
  2004年   2748篇
  2003年   2568篇
  2002年   2016篇
  2001年   1986篇
  2000年   1384篇
  1999年   1163篇
  1998年   994篇
  1997年   883篇
  1996年   887篇
  1995年   794篇
  1994年   703篇
  1993年   519篇
  1992年   475篇
  1991年   448篇
  1990年   444篇
  1989年   350篇
  1988年   178篇
  1987年   149篇
  1986年   106篇
  1985年   67篇
  1984年   31篇
  1983年   25篇
  1982年   13篇
  1981年   3篇
  1980年   2篇
  1956年   1篇
  1955年   5篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
实例:患者,男,42岁。因心悸、气促3个月就诊。心电图:快速心房颤动。初步诊断:风湿性心脏病,二尖瓣狭窄并快速心房颤动。给予胺碘酮和维拉帕米口服。  相似文献   
102.
Nobre  SM  吴渭 《中国医药工业杂志》2005,36(11):698-698
在钯催化的Suzuki交叉偶联反应中,以聚环氧乙烷-甲醇为混合溶剂,反应结束后用正庚烷提取,产物进入非极性相,收率〉90%。催化剂留在极性相,可循环使用多次。  相似文献   
103.
某些疾病可能引起暂时性抗原减弱,血清抗体下降而导致血型鉴定困难。聚凝胺技术具有敏感性高、反应快速等优点,对ABO血型的鉴定有辅助作用。我们采用聚凝胺法辅助鉴定ABO血型2例,现报告如下。  相似文献   
104.
105.
对铅超标的酒类,既往常应用“凝固沉淀法”或“重蒸馏法”除铅。但用这些方法处理铅超标的原汁果酒,则易丧失该果酒固有的营养成分和风味特色。作者应用“阳离子交换法”除铅,不仅除铅效果良好,而且保留了该原汁果酒的营养成分和风味特色。  相似文献   
106.
痤疮是青年人群中最常见的一种皮肤病,重度痤疮常因面部出现较多炎性皮疹、囊肿、结节而使容貌受损,极大地影响患者身心健康。本病治疗方法较多,但疗效不满意。2000年以来,笔者应用口服异维A酸联合白花蛇舌草针肌肉注射治疗本病,取得较好效果,现报道如下。  相似文献   
107.
《传染病网络动态》2006,(2):125-125
目的:观察托尼萘酸治疗老年戊型肝炎的安全性及临床疗效。方法:56例老年戊型肝炎病人分为治疗组和对照组,2组病人均给予常规护肝、支持、对症治疗。治疗组36例,男性28例,女性8例:年龄(67&;#177;s11)a。加用托尼萘酸,2片,po,tid。对照组20例,男性16例,女性4例:年龄(66+12)a,仅给予基础治疗。治疗后4,8wk时比较2组病人的临床指标改变。  相似文献   
108.
脂肪胺和α,β-不饱和羰基化合物的水溶液,以3mol%硝酸铈铵为催化剂,室温搅拌制得相应的B.氨基羰基化合物。环状仲胺5~30min即可完成;芳香胺不反应。20例收率55%~99%。  相似文献   
109.
目的:探讨树脂吸附剂治疗急性摇头丸中毒的疗效。方法:将36例急性摇头丸中毒患者随机分为常规治疗组(常规组)和常规治疗基础上加树脂吸附治疗组(树脂组),观察比较治疗后3、6、12h两组的疗效、副作用和并发症。结果:治疗组的疗效明显优于对照组(H=3.9,P<0.05),尤其是6h时疗效更佳(H=10.4,P<0.01);2组均未发现明显的副作用和并发症。结论:树脂吸附能迅速清除血液中的有毒物质,可有效治疗急性摇头丸中毒。  相似文献   
110.
BACKGROUND: As a non-invasive technique which can provide comprehensive biological information, 1H-magnetic resonance spectroscopy (1H-MRS) may provide valuable reference data for irreversible recovery or reversible changes in ischemic tissue after stroke. OBJECTIVE: To monitor and evaluate the effect of the urokinase thrombolytic therapy after experimental acute cerebral ischemia by 1H-MRS technology and investigate its adaptability. DESIGN: Randomly controlled animal study. SETTINGS: Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom & Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science. MATERIALS: Eleven healthy adult Sprague-Dawley (SD) rats, weighing 260–300 g and of both genders, were supplied by Experimental Animal Center of Tongji Medical Collage, Huazhong University of Science and Technology [SCXK (e) 2004-007]. 4.7T superconducting nuclear magnetic resonance meter was provided by Brucker Company. METHODS: The experiment was carried out in Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom & Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science from August 2003 to December 2005. ① The rats were randomly divided into 30-minute self-thrombo-embolism group (n =6) and 60-minute self-thrombo-embolism group (n =5). Six rats in 30-minute self-thrombo-embolism group were occluded with clot embolus for 30 minutes and 5 rats in 60-minute self-thrombo-embolism group were occluded for 60 minutes. 10 000 U/kg urokinase was dissolved in 2 mL saline and the operation lasted for 5 minutes. ② 1H-MRS was performed before thrombolysis and at 3 hours and 24 hours after successful embolization. The metabolic changes of N-acetyl-L-aspartic acid (NAA)/phosphocreatine (PCr) + creatine (Cr), choline phosphate (Cho)/PCr+Cr and lactic acid (Lac)/PCr+Cr in the region of interests were analyzed. ③ The T2W image was conducted 24 hours after the thrombolytic therapy with TR=500 ms and TE=25 ms. ④ The subjects were sacrificed immediately after 1H-MRS and the brain tissues were cut into pieces and stained with HE method; in addition, pathological changes were observed under optic microscope. MAIN OUTCOME MEASURES: ① Metabolic changes of NAA/PCr+Cr, Cho/PCr+Cr and Lac/PCr+Cr in the region of interests; ② T2W image at 24 hours after the thrombolysis; ③ pathological observation of brain tissue. RESULTS: Eleven rats were all involved in the final analysis. ① Metabolic changes in the region of interests : In 30-minute self-thrombo-embolism group, the Lac peak emerged immediately after the embolism, but the ischemic zone decreased 3 hours after the thrombolytic therapy (0.252±0.01, 0.603±0.01, P < 0.01). Lac/(PCr+Cr) ratio was 0.290±0.01 at 24 hours after thrombolysis, which was higher than that at 3 hours after thrombolysis (P < 0.01). The NAA/ (PCr+Cr) ratio decreased significantly at 3 hours after the thrombolysis as compared with that before thrombolysis (0.922±0.16, 1.196±0.01, P < 0.05). In 60-minute self-thrombo-embolism group, the Lac/(PCr+Cr) ratio was higher at 3 hours after thrombolysis than that before thrombolysis (0.846±0.12, 0.601±0.11, P < 0.05) and the NAA/(PCr+Cr) decreased at 3 hours after the embolism. Fluctuation of NAA/ (PCr+Cr) ranged from 0.68 to 0.75 before thrombolysis and from 0.71 to 0.75 at 3 hours after thrombolysis. ② T2W image: T2W image showed that 2 subjects in 30-minute self-thrombo-embolism group whose Lac/NAA was higher than 0.7 suffered from intracranial hemorrhage. This meant that the subjects with Lac/NAA > 0.7 were more likely to suffer from intracranial hemorrhage. ③ Histological and morphological examinations: Optic microscope demonstrated that interspace surrounding nerve cells was widened at ischemic center; neurons were swelling; nucleus was stained lightly; pyknosis and mesenchymal edema were mainly observed in lateral cortex of brow and vertex and in lateral part of corpus striatum. CONCLUSION: ①Compound parameters in ischemic area before thrombolysis should be regarded as an important predicting marker for thrombolytic therapy, effect evaluation and termination. ② 1H-MRS combining with other imaging technique is a detecting way for screening cases who are suitable for thrombolytic therapy.  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