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   25090篇
  免费   1281篇
  国内免费   78篇
耳鼻咽喉   335篇
儿科学   1413篇
妇产科学   614篇
基础医学   2756篇
口腔科学   561篇
临床医学   1426篇
内科学   5282篇
皮肤病学   797篇
神经病学   1566篇
特种医学   777篇
外科学   3265篇
综合类   790篇
一般理论   16篇
预防医学   1270篇
眼科学   1391篇
药学   2287篇
中国医学   182篇
肿瘤学   1721篇
  2023年   150篇
  2022年   273篇
  2021年   882篇
  2020年   435篇
  2019年   569篇
  2018年   727篇
  2017年   499篇
  2016年   629篇
  2015年   583篇
  2014年   944篇
  2013年   1148篇
  2012年   1630篇
  2011年   1772篇
  2010年   944篇
  2009年   782篇
  2008年   1199篇
  2007年   1247篇
  2006年   1265篇
  2005年   1091篇
  2004年   1003篇
  2003年   847篇
  2002年   786篇
  2001年   705篇
  2000年   702篇
  1999年   562篇
  1998年   231篇
  1997年   165篇
  1996年   143篇
  1995年   152篇
  1994年   115篇
  1993年   102篇
  1992年   369篇
  1991年   372篇
  1990年   341篇
  1989年   329篇
  1988年   284篇
  1987年   251篇
  1986年   236篇
  1985年   232篇
  1984年   173篇
  1983年   136篇
  1981年   92篇
  1979年   157篇
  1978年   97篇
  1977年   81篇
  1975年   84篇
  1974年   101篇
  1973年   92篇
  1972年   120篇
  1970年   78篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
993.
994.
995.
996.
997.
Mandavdhare  Harshal S.  Praveen Kumar  M.  Jha  Dayakrishna  Kumar  Antriksh  Sharma  Vishal  Desai  Pankaj  Shumkina  Lada  Gupta  Pankaj  Singh  Harjeet  Dutta  Usha 《Esophagus》2021,18(3):436-450

The traditional way to tackle Zenker’s diverticulum (ZD) has been flexible endoscopic septum division (FESD). Recently, the concept of per oral endoscopic myotomy has been found useful for managing diverticular diseases of the esophagus and has been termed DPOEM. We performed a systematic review and meta-analysis to evaluate the efficacy and safety of D-POEM in diverticular disease of the esophagus and to compare it with FESD. We systematically searched PubMed and Embase, for studies reporting clinical success, technical success and adverse events in D-POEM alone or D-POEM comparing with FESD. We computed pooled prevalence for D-POEM alone and risk ratio for D-POEM vs FESD using random effect method with inverse variance approach. Subgroup analysis for ZD, non-ZD and mixed diverticulum was conducted. Totally 19 studies including 341 patients were identified reporting on D-POEM. The pooled clinical, technical success and adverse event rates for D-POEM were 87.07%, 95.19% and 10.22%, respectively. The clinical success was significantly better than FESD while the technical success, adverse event rate, procedure time and length of hospital stay were comparable with FESD. The recurrence rate was negligible for D-POEM compared to FESD. On subgroup analysis by dividing into three groups of ZD, non-ZD and mixed, there was no difference between clinical, technical success and adverse event rate among the three groups. D-POEM is an effective and safe technique among both ZD and non-ZD patients and has better clinical success than FESD.

  相似文献   
998.
A sensitive and selective ultra fast liquid chromatography (UFLC) method has been developed and validated for the determination of a potent and novel antitubercular compound S006‐830 in Sprague Dawley (SD) rat plasma. Samples were extracted and processed by protein precipitation method using acetonitrile. Chromatographic separation was achieved on a Phenomenex, Luna C‐18 column (3μm, 100mm x 2mm i.d.) under isocratic condition. Detection was performed on UFLC‐NEXERA system (LC‐30AD, Shimadzu, Kyoto, Japan) with a degasser (DGU‐20A), auto‐injector (SIL‐30AC), fixed with a 100‐μL loop. Method was found sensitive and reproducible over a linearity range of 15.6‐2000 ng/mL. Recovery of S006‐830 and internal standard was found >90% for spiked matrix control and standard quality control plasma samples. This validated method was successfully applied to generate pharmacokinetic profile of S006‐830 in SD rats. Oral dose proportionality studies were conducted at 100, 50, 25 mg/Kg dose levels, while an IV study was conducted at 25 mg/Kg dose. There was dose dependent increase in AUC and Cmax indicating S006‐830 to exhibit linear pharmacokinetics. S006‐830 exhibited favorable bioavailability in the range of 45‐55%. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
999.
This paper describes a systematic approach to overcoming challenges in developing a robust and selective liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) method for reliable and precise determination of carglumic acid in human plasma. Sample extraction was tested on several reversed‐phase solid‐phase extraction (SPE) sorbents with different chemistries, such as hydrophobic C18, hydrophilic‐lipophilic balance, and mixed‐mode cation and anion exchange. The best recovery under the optimized extraction conditions was obtained with Oasis MAX (30 mg, 1cc) mixed‐mode anion exchange (~ 50%) cartridge, compared to other sorbents from 100 μL plasma sample. Complete analytical separation of carglumic acid and carglumic acid‐13C5 15N as an internal standard (IS) from endogenous plasma components was achieved on ACE 5CN (150 × 4.6 mm, 5 µm) column under isocratic conditions using acetonitrile:methanol (50:50, v/v) ? 0.1% acetic acid in water [80:20, v/v] as the mobile phase. The deprotonated precursor → product ion transitions for carglumic acid (189/146) and IS (195/152) were monitored in the negative ionization mode on a triple quadrupole mass spectrometer. The regression curves were linear over a concentration range of 6.00‐6000 ng/mL (r2 ≥ 0.9987). Matrix effect was evaluated in terms of IS‐normalized matrix factors, which ranged from 0.95 to 1.01 across four quality control levels. Intra‐ and inter‐batch accuracy and precision, and the stability of carglumic acid in spiked plasma samples were assessed under different conditions. The method was applied to assess the pharmacokinetics of 100 mg/kg body weight carglumic acid in a healthy Indian subject. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
1000.
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