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   960篇
  免费   65篇
  国内免费   3篇
耳鼻咽喉   9篇
儿科学   42篇
妇产科学   16篇
基础医学   115篇
口腔科学   57篇
临床医学   49篇
内科学   208篇
皮肤病学   19篇
神经病学   69篇
特种医学   33篇
外科学   128篇
综合类   30篇
预防医学   49篇
眼科学   61篇
药学   69篇
中国医学   4篇
肿瘤学   70篇
  2023年   15篇
  2022年   38篇
  2021年   63篇
  2020年   33篇
  2019年   32篇
  2018年   41篇
  2017年   27篇
  2016年   46篇
  2015年   40篇
  2014年   50篇
  2013年   60篇
  2012年   92篇
  2011年   96篇
  2010年   44篇
  2009年   31篇
  2008年   36篇
  2007年   51篇
  2006年   41篇
  2005年   35篇
  2004年   26篇
  2003年   24篇
  2002年   19篇
  2001年   6篇
  2000年   7篇
  1999年   7篇
  1998年   7篇
  1997年   2篇
  1996年   3篇
  1994年   2篇
  1993年   3篇
  1992年   3篇
  1991年   2篇
  1990年   2篇
  1989年   7篇
  1988年   3篇
  1987年   3篇
  1986年   2篇
  1985年   3篇
  1981年   2篇
  1976年   2篇
  1975年   3篇
  1974年   2篇
  1973年   2篇
  1970年   4篇
  1969年   1篇
  1968年   1篇
  1930年   1篇
  1925年   1篇
  1924年   1篇
  1922年   1篇
排序方式: 共有1028条查询结果,搜索用时 0 毫秒
1.
Laparoscopic cholecystectomy for left-sided gallbladder (sinistroposition).   总被引:1,自引:0,他引:1  
Transposition of the gallbladder to the left side without situs inversus viscerum is rare. These gallbladders are situated under the left lobe of the liver between Segment III and IV or on Segment III to the left of the falciform ligament. Because routine preoperative studies may not detect the anomaly, it may provide the surgeons with an unusual surprise during laparoscopy. Awareness of the unpredictable confluence of the cystic duct into the common bile duct and selective use of intraoperative cholangiography aid in the safe laparoscopic management of this unusual problem.  相似文献   
2.
目的:鉴定现行的治疗方法并评价其对子宫内膜增生妇女的治疗效果。研究设计:研究1998年10月至2000年9月期间所有在伯明翰妇女医院,经组织学诊断为子宫内膜增生的妇女。应用标准化资料提取表对每一位妇女进行回顾性病例研究,基线特征包括临床表现和治疗方案。应用治疗后子宫内膜组织的检查结果来评价治疗方法的组织学反应,用是否需要子宫切除术及其指征来评价临床反应。结果:在研究期间有351例妇女被诊断为子宫内膜增生,其中84%表现出异常子宫出血的症状且54%的患者已绝经。合并子宫内膜增生是最常见的诊断,占所有病例的60%。无细胞学非典型…  相似文献   
3.
4.
Memory B cells of mice with Ig mu transgenes often carry transgene copies that have moved into the Igh locus via somatic translocation. This phenomenon has been attributed to a selection pressure for somatic hypermutations, which generally are observed at much higher frequencies in translocated copies than in ectopic copies. We tested this idea by immunizing Ig-mu transgenic mice in a manner designed to select B cells that required only one V(H) mutation for a switch in antigenic specificity and recruitment into the memory pool. Despite the minimal mutation requirement, hybridomas carrying somatic translocations to the Igh locus were obtained. Importantly, this occurred despite the fact that translocated and untranslocated mu-transgenes were mutated comparably. Evidently, a strong selection advantage was conferred upon B cells by the somatic translocations. Among the hybridomas, translocated mu-transgenes were active, while ectopic mu-transgenes were uniformly silent. The translocated copy that had conferred an affinity-based selection advantage was expressed at the highest level. Moreover, translocated copies were differentially expressed among hybridoma members, which belonged to a common post-mutational lineage. This suggests that adjustments in transgene expression levels had occurred during memory cell development. These results indicate that, apart from their potential influences on somatic hypermutagenesis and class switch recombination, elements in the Igh locus promote the selection of memory B cells in another way, possibly by regulating the level of Ig expression at various stages of antigen-driven differentiation.  相似文献   
5.

The influence of fluctuating water temperature and dietary oxytetracycline (OTC) at 0 (0X), 80 (1X), 240 (3X), 400 (5X) and 800 mg (10X)/kg biomass/day for 30 consecutive days on the safety of monosex (all male) Nile tilapia Oreochromis niloticus fries in terms of feeding, growth, survival and histopathology of vital organs were assessed. A dose-dependent decline in feed intake and biomass was recorded. The OTC-dosed groups recorded higher mortalities than the control. The therapeutic OTC-dosing (1X) in conjunction with low temperature caused 75.56 ± 8.01% mortality and 25.75% reduced feed intake in 30 days. The mortalities increased with increasing OTC-doses from 85.19 ± 3.39% (1X) to 95.56 ± 2.22% (10X) and fluctuating temperature (12.00–21.50°C) even after the withdrawal of OTC. Relatively mild to moderate histopathological lesions were observed in the kidney, liver and intestine of OTC-dosed fries. These results suggested that dietary OTC and low water temperature may cause adverse effects on monosex O. niloticus fries.

  相似文献   
6.
Background:Traditional methods for neuroretinal rim width measurement in spectral domain optical coherence tomography (SD-OCT) employs the Bruch‘s membrane opening (BMO) as the anatomical border of the rim, referenced to a BMO horizontal reference plane, termed as “Bruch’s Membrane Opening-Horizontal Rim Width” (BMO-HRW). BMO-HRW is defined as the distance between BMO and internal limiting membrane (ILM) on the horizontal plane. In contrast, the Spectralis OCT (Heidelberg Engineering, Germany) employs a new parameter called “Bruch’s Membrane Opening–Minimum Rim Width” (BMO-MRW) with Glaucoma Module Premium Edition (GMPE). GMPE provides a novel objective method of optic nerve head (ONH) analysis using BMO, but the neuroretinal rim assessment is performed from the BMO to the nearest point on the ILM, rather than on the horizontal reference plane. It is the BMO-MRW and is defined as the minimum distance between the BMO and ILM in the ONH.Purpose:In this video, anatomy of the ONH and GMPE is decoded from a neophyte user’s point of view, as to why BMO-MRW is more important than the traditional BMO-HRW for glaucoma evaluation.Synopsis:The GMPE concepts are depicted in a novel dynamic (Clinical vs OCT Vs Histology) screenplay, detailing the below focal points with 2D & 3D animations: True Margin of ONH, Bruch’s Membrane (BM), Histology Vs OCT, BMO, Bruch’s Membrane Opening-Minimum Rim Width, Bruch’s Membrane Opening-Minimum Rim Width Versus Bruch’s Membrane Opening-Horizontal Rim Width, Alpha, Beta, Gamma Zone of ONH in OCT, Anatomic Positioning System, Impact of Fovea Bruch’s Membrane Opening Centre Axis.Highlights:This video also highlights, how with the advent of Anatomic Positioning System, scans were able to align relative to the individual’s Fovea-to-BMO-center (FoBMOC) axis at every follow-up, for accurately detecting changes, as small as 1 micron in BMO-MRW, thus creating a new world in diagnosing glaucoma and detecting glaucomatous progression with precision.Video link: https://youtu.be/6RqF5guAziw  相似文献   
7.
8.
9.
10.
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