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   156109篇
  免费   10394篇
  国内免费   2700篇
耳鼻咽喉   2237篇
儿科学   2422篇
妇产科学   2051篇
基础医学   21840篇
口腔科学   3533篇
临床医学   15788篇
内科学   24672篇
皮肤病学   4295篇
神经病学   10668篇
特种医学   8124篇
外科学   19817篇
综合类   8756篇
现状与发展   11篇
一般理论   27篇
预防医学   10546篇
眼科学   3621篇
药学   15065篇
  29篇
中国医学   4424篇
肿瘤学   11277篇
  2024年   191篇
  2023年   975篇
  2022年   2970篇
  2021年   5462篇
  2020年   3162篇
  2019年   3438篇
  2018年   4198篇
  2017年   3764篇
  2016年   4517篇
  2015年   6561篇
  2014年   8013篇
  2013年   9476篇
  2012年   14101篇
  2011年   13679篇
  2010年   8950篇
  2009年   7814篇
  2008年   10096篇
  2007年   9568篇
  2006年   8589篇
  2005年   7713篇
  2004年   6404篇
  2003年   5517篇
  2002年   4619篇
  2001年   3726篇
  2000年   3312篇
  1999年   2278篇
  1998年   932篇
  1997年   690篇
  1996年   537篇
  1995年   469篇
  1994年   419篇
  1993年   343篇
  1992年   758篇
  1991年   706篇
  1990年   644篇
  1989年   557篇
  1988年   470篇
  1987年   469篇
  1986年   337篇
  1985年   369篇
  1984年   263篇
  1983年   196篇
  1982年   136篇
  1981年   168篇
  1980年   128篇
  1979年   222篇
  1978年   162篇
  1976年   135篇
  1975年   121篇
  1974年   139篇
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
11.
12.
中药生产过程质量控制关键技术研究进展   总被引:10,自引:8,他引:2  
中医药发展已上升到国家战略层面,在医药行业贯彻实施"中国制造2025"战略的新形势下,中药生产过程质量控制是中药工业需要加快突破的关键领域之一。对中药生产过程质量控制领域在工艺设计、分析检测、过程建模、制造装备等方面的关键共性问题进行解析,综述了中药生产过程质量控制体系中工艺过程理解、生产过程实时分析方法开发、过程控制策略建立3个方面的研究进展;并结合企业研究实践,介绍了质量源于设计(quality by design,Qb D)、过程分析技术(process analytical technology,PAT)、实验设计(design of experiment,DOE)、多变量统计分析等关键技术在上述3个研究方向中的应用进展,分析了实际工业应用的难点问题并对其应用前景进行展望,旨在为中药企业应用和提升生产过程质量控制技术提供参考。  相似文献   
13.
14.
Direct peroral cholangioscopy (POC) using an ultra‐slim upper endoscope is one modality of POC for intraductal endoscopic evaluation and treatment of the bile duct. Choledochoduodenostomy (CDS) is one modality of biliary bypass surgery that provides a new route to the bile duct. We carried out direct POC using an ultra‐slim upper endoscope without the use of accessories in 10 patients (four sump syndromes, three bile duct strictures and three intrahepatic duct stones) previously undergoing surgical CDS. Direct POC was successful in all patients. The use of an intraductal balloon catheter was required in one patient for advancement of the endoscope into the bile duct. Distal bile ducts with sump syndromes were cleared using baskets and water irrigation under direct POC. Cholangiocarcinoma was diagnosed in one patient with hilar bile duct stricture after cholangioscopic evaluation and a targeting forceps biopsy under direct POC. Intrahepatic duct stones were successfully extracted after intraductal fragmentation under direct POC. Oozing bleeding occurred during intraductal lithotripsy but stopped spontaneously. Direct POC using an ultra‐slim upper endoscope without the assistance of accessories can easily be carried out in patients undergoing CDS.  相似文献   
15.
16.
17.
18.
The identification of EGFR mutations in non‐small‐cell lung cancer is important for selecting patients, who may benefit from treatment with EGFR tyrosine kinase inhibitors. The analysis is usually performed on cytological aspirates and/or histological needle biopsies, representing a small fraction of the tumour volume. The aim of the present investigation was to evaluate the diagnostic performance of this molecular test. We retrospectively included 201 patients with primary adenocarcinoma of the lung. EGFR mutation status (exon 19 deletions and exon 21 L858R point mutation) was evaluated on both pre‐operative biopsies (131 histological and 70 cytological) and on the surgical specimens, using PCR. Samples with low tumour cell fraction were assigned to laser micro‐dissection (LMD). We found nine (4.5%) patients with EGFR mutation in the lung tumour resections, but failed to identify mutation in one of the corresponding pre‐operative, cytological specimens. Several (18.4%) analyses of the pre‐operative biopsies were inconclusive, especially in case of biopsies undergoing LMD and regarding exon 21 analysis. Discrepancy of mutation status in one patient may reflect intra‐tumoural heterogeneity or technical issues. Moreover, several inconclusive results in the diagnostic biopsies reveal that attention must be paid on the suitability of pre‐operative biopsies for EGFR mutation analysis.  相似文献   
19.
A 48-year-old smoker with a history of hyperthyroidism treated 10 years prior to presentation with radioactive iodine ablation of the thyroid gland presented to his ophthalmologist with a 2-week history of transient loss of vision in the right eye occurring for 1 to 2 hours each morning. He denied ocular pain, diplopia or change in the prominence of one or both eyes. Examination revealed 2 mm of relative proptosis on the right, bilateral temporal flare and lower lid retraction. There was minimal upper lid retraction and no evidence of lid lag. Ocular motility was full. Dilated fundoscopic examination revealed bilateral optic nerve edema, right more than left. CT of the orbit demonstrated enlargement of the extraocular muscles bilaterally with marked enlargement of the right medial rectus and left inferior rectus muscles resulting in crowding at the orbital apex bilaterally. Laboratory testing revealed the patient to be hyperthyroid. The patient was treated with high dose oral steroids followed by orbital radiation. Hyperthyroidism was managed by the patient’s primary care physician. Visual symptoms rapidly improved with oral steroids and orbital radiation. Optic nerve edema completely resolved. Repeat CT imaging demonstrated a reduction in the enlargement of the extraocular muscles with relief of bilateral optic nerve compression.  相似文献   
20.
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