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   1701篇
  免费   119篇
  国内免费   11篇
耳鼻咽喉   6篇
儿科学   98篇
妇产科学   15篇
基础医学   191篇
口腔科学   50篇
临床医学   185篇
内科学   292篇
皮肤病学   20篇
神经病学   116篇
特种医学   340篇
外科学   125篇
综合类   18篇
预防医学   134篇
眼科学   70篇
药学   72篇
肿瘤学   99篇
  2021年   13篇
  2020年   9篇
  2019年   8篇
  2018年   17篇
  2017年   7篇
  2016年   11篇
  2015年   21篇
  2014年   28篇
  2013年   43篇
  2012年   37篇
  2011年   35篇
  2010年   37篇
  2009年   38篇
  2008年   48篇
  2007年   53篇
  2006年   42篇
  2005年   44篇
  2004年   41篇
  2003年   32篇
  2002年   35篇
  2001年   28篇
  2000年   27篇
  1999年   36篇
  1998年   100篇
  1997年   74篇
  1996年   89篇
  1995年   65篇
  1994年   66篇
  1993年   69篇
  1992年   23篇
  1991年   33篇
  1990年   30篇
  1989年   56篇
  1988年   46篇
  1987年   67篇
  1986年   39篇
  1985年   44篇
  1984年   39篇
  1983年   31篇
  1982年   25篇
  1981年   32篇
  1980年   33篇
  1979年   15篇
  1978年   28篇
  1977年   27篇
  1976年   30篇
  1975年   19篇
  1974年   6篇
  1972年   11篇
  1970年   7篇
排序方式: 共有1831条查询结果,搜索用时 15 毫秒
1.
Needle-localized breast biopsy: why do we fail?   总被引:10,自引:0,他引:10  
Jackman  RJ; Marzoni  FA  Jr 《Radiology》1997,204(3):677
  相似文献   
2.
M K Sorenson 《Physical therapy》1989,69(12):1059-1064
The purpose of this article is to increase the therapist's awareness of the effects of edema on the hand and the need for early treatment. The physiology of tissue fluid production and the two basic types of edema are discussed. The use of elevation, compression, and active exercise are the primary methods of controlling edema in the hand. Various modalities and commercial compression dressings are helpful for intractable edema; however, early intervention and treatment of the edematous hand can prevent subsequent hand dysfunction and sequelae.  相似文献   
3.
The Enhancing Patient Prenatal Education study tested the feasibility and educational impact of an interactive program for patient prenatal genetic screening and testing education. Patients at two private practices and one public health clinic participated (N = 207). The program collected knowledge and measures of anxiety before and after use of the tool. Time in various prenatal visit activities was collected prior to and after the introduction of the education tool. Providers completed an assessment of their experiences with patients who had used the program. Results indicate that patient knowledge significantly increased from pre to post (p = .0001) with no increase in anxiety (p = .31). Time in clinic activities, including overall visit time, increased. A majority of providers indicated that the program disrupted clinic flow. This assessment suggests that the program increases patient knowledge and does not increase patient anxiety. However, challenges remain to using this program in a clinic setting.  相似文献   
4.
Interaction between anti-inflammatory drugs and reactive oxygen metabolites must be considered in the course of pharmacological studies intended to develop new compounds. Effects of indomethacin, aspirin, and 3,5-diisopropylsalicylic acid (3,5-DIPS) and their copper complexes on PMNL oxidative metabolism and the evolution of an acute inflammatory reaction were studied in the rat. Experiments were performed in vitro by assessment of superoxide generation and reduction of chemiluminescence by PMNLs incubated or not (control) in medium containing various concentrations of these compounds. A dose-related decrease of these parameters was observed, however, copper complexes were found to be more effective than their parent drugs or Cu gluconate. Copper complexes were also more effective anti-inflammatory agents than their parent ligands or Cu gluconate when the volume of exudate and number of exudate PMNLs were assessed after induction of pleurisy in rats by injection of isologous serum. It is concluded that modulation of the PMNL oxidative burst by copper complexes offers an accounting for the anti-inflammatory activity of these compounds.  相似文献   
5.
6.
A general model is developed for segmenting magnetic resonance images using vector decomposition and probabilfty techniques. Each voxel is assigned fractional volumes of q tissues from p differently weighted images (qp + 1) in the presence of partial-volume mixing, random noise, and other tissues. Compared wtth the eigenimage method, fewer differently weighted images are needed for segmenting the q tissues, and the contrast-to-noise ratio in the calculated fractional volumes is improved. The model can produce com-posrte tissue-type images similar to that of the probability methods, by comparing the fractional volumes assigned to different tissues on each voxel. A three-tissue (p = 2, q = 3) model is illustrated for segmenting three tissues from dual-echo images. M provides statistical analysis to the algebraic method. A three-compartment phantom is segmented for validation. Two clinical examples are presented.  相似文献   
7.
8.
荧光原位杂交技术分析人结肠菌群方法研究   总被引:2,自引:0,他引:2  
建立荧光原位杂交技术分析人体内结肠菌群的方法。取受试者新鲜粪便 ,选用 5种特异性的 16SrRNA寡核苷酸探针 ,检测粪便样本收集后的保存时间、温度 ,离心条件及样本固定液存放时间对杂交计数结果的影响。结果建立最佳实验条件为 :粪便样本收集后应尽快在 4℃下保存 ,放置时间不要超过 12小时即作处理 ;样本的适宜离心条件为 70 0g 2分钟 ;样本用多聚甲醛固定后在 - 80℃下存放时间不要超过 5个月。该方法具有较好的稳定性 ,可以有效地检出个体之间结肠菌群的差异。  相似文献   
9.
We evaluated the effects of unsharp masking and highly efficient scatter rejection on film-screen chest radiographs of cancer patients. Unsharp masking significantly improved the detectability of lung nodules and visibility of anatomic structures in poorly penetrated areas of the chest. Highly efficient scatter rejection by an improved antiscatter grid provided only modest additional benefits. The study supports the conclusion that nodule detection in poorly penetrated areas on conventional chest radiographs is limited primarily by display contrast, whereas in the well-penetrated lung fields it is limited primarily by confusing background structures, rather than inadequate contrast. A method for analyzing clinical nodule detection data by transforming the FROC data to ROC coordinates also is demonstrated.  相似文献   
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