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   9335篇
  免费   600篇
  国内免费   76篇
耳鼻咽喉   159篇
儿科学   241篇
妇产科学   282篇
基础医学   1063篇
口腔科学   141篇
临床医学   877篇
内科学   2328篇
皮肤病学   134篇
神经病学   990篇
特种医学   281篇
外科学   1617篇
综合类   85篇
一般理论   2篇
预防医学   618篇
眼科学   77篇
药学   520篇
  1篇
中国医学   28篇
肿瘤学   567篇
  2024年   12篇
  2023年   78篇
  2022年   209篇
  2021年   367篇
  2020年   195篇
  2019年   321篇
  2018年   334篇
  2017年   229篇
  2016年   282篇
  2015年   337篇
  2014年   414篇
  2013年   538篇
  2012年   803篇
  2011年   797篇
  2010年   405篇
  2009年   353篇
  2008年   624篇
  2007年   666篇
  2006年   582篇
  2005年   554篇
  2004年   499篇
  2003年   480篇
  2002年   374篇
  2001年   54篇
  2000年   42篇
  1999年   44篇
  1998年   56篇
  1997年   32篇
  1996年   35篇
  1995年   30篇
  1994年   21篇
  1993年   24篇
  1992年   15篇
  1991年   17篇
  1990年   15篇
  1989年   19篇
  1988年   9篇
  1987年   6篇
  1986年   5篇
  1985年   14篇
  1984年   10篇
  1983年   16篇
  1982年   14篇
  1981年   11篇
  1980年   8篇
  1979年   5篇
  1977年   5篇
  1976年   6篇
  1974年   5篇
  1971年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Bulletin of Environmental Contamination and Toxicology - The holistic approach of Driver-Pressure-State-Impact-Response (DPSIR) methodology was applied to selected Cr(VI) impacted groundwater...  相似文献   
32.
Duchenne muscular dystrophy (DMD), a severe X-linked recessive disorder which results in progressive muscle degeneration, is due to a lack of dystrophin, a membrane cytoskeletal protein. An approach to treatment is to compensate for dystrophin loss with utrophin, another cytoskeletal protein with over 80% homology with dystrophin. Utrophin is expressed, at the neuromuscular junction, in normal and DMD muscles and there is evidence that it may perform the same cellular functions as dystrophin. So, the identification of molecules or drugs that could up-regulate utrophin is a very important goal for therapy. We show that in adult normal and mdx mice (an animal model of Duchenne myopathy) treated with -arginine, the substrate of nitric oxide synthase (NOS), a pool of utrophin localized at the membrane appeared and increased, respectively. In normal and mdx myotubes in culture, -arginine, nitric oxide (NO), or hydroxyurea increased utrophin levels and enhanced its membrane localization. This effect did not occur with -arginine, showing the involvement of NOS in this process. The NO-induced increase in utrophin was prevented by oxadiazolo-quinoxalin-1-one, an inhibitor of a soluble guanylate cyclase implicated in NO effects. These results open the way to a potential treatment for Duchenne and Becker dystrophies.  相似文献   
33.
A technique for endoscopic primary re-alignment of ruptured urethra is described. It is safe, simple and may be accomplished under neuroleptic or local anesthesia. Morbidity is low and hospitalization minimal. Any residual stricture can be easily managed endoscopically or by simple dilation.  相似文献   
34.
PURPOSE: Arsenic trioxide (ATO) is capable of inducing a high hematologic response rate in patients with relapsed acute promyelocytic leukemia (APL). Preclinical observations have indicated that all-trans-retinoic acid (ATRA) may strongly enhance the response to ATO. PATIENTS AND METHODS: Between 1998 and 2001, we conducted a randomized study of ATO alone versus ATO plus ATRA in 20 patients with relapsed APL, all previously treated with ATRA-containing chemotherapy. The primary objective was to demonstrate a significant reduction in the time necessary to obtain a complete remission (CR) in the ATO/ATRA group compared with the ATO group. Secondary objectives were safety and molecular response. RESULTS: The CR rate after one ATO with or without ATRA induction cycle was 80%. Clinical and pharmacokinetic observations indicated that the main mechanism of action of ATO in vivo was the induction of APL cell differentiation. Hematologic and molecular response, time necessary to reach CR, and outcome were comparable in both treatment groups. Of 16 CR patients, three patients who reached a molecular remission after one induction cycle had all received chemotherapy for a treatment-induced hyperleukocytosis. Three additional patients who received further additional ATO with or without ATRA cycles converted later to molecular negativity. CONCLUSION: ATRA did not seem to significantly improve the response to ATO in patients relapsing from APL. Other potential combinations, including ATO plus chemotherapy, have to be tested.  相似文献   
35.
BACKGROUND AND PURPOSE: The appropriate application of 3-D CRT and IMRT for HNSCC requires a standardization of the procedures for the delineation of the target volumes. Over the past few years, two proposals--the so-called Brussels guidelines from Grégoire et al., and the so-called Rotterdam guidelines from Nowak et al.--emerged from the literature for the delineation of the neck node levels. Detailed examination of these proposals however revealed some important discrepancies. MATERIALS AND METHODS: Within this framework, the Brussels and Rotterdam groups decided to review their guidelines and derive a common set of recommendations for delineation of neck node levels. This proposal was then discussed with representatives of major cooperative groups in Europe (DAHANCA, EORTC, GORTEC) and in North America (NCIC, RTOG), which, after some additional refinements, have endorsed them. The objective of the present article is to present the consensus guidelines for the delineation of the node levels in the node-negative neck. RESULTS AND CONCLUSIONS: First a short discussion of the discrepancies between the previous Brussels and the Rotterdam guidelines is presented. The general philosophy of the consensus guidelines and the methodology used to resolve the various discrepancies are then described. The consensus proposal is then presented and representative CTVs that are consistent with these guidelines are illustrated on CT sections. Last, the limitations of the consensus guidelines are discussed and some concerns about the direct applications of these guidelines to the node-positive neck and the post-operative neck are described.  相似文献   
36.
37.
Small intestinal obstruction and perforation associated with endometriosis is uncommon. We report a similar effect following treatment with the combined oral contraceptive. Caution should be exercised when prescribing the combined oral contraceptive in women with suggested small intestinal endometriosis. Disease flare-up after therapy may be associated with intestinal obstruction and perforation.  相似文献   
38.
39.
40.
PurposeTo assess the feasibility of applying ultra-widefield fundus (UWF) images for macular staphyloma area (MSA) measurement and investigate the associated factors with MSA.MethodsThis is a retrospective study. MSA was measured by UWF imaging. Central foveal thickness, subfoveal choroidal thickness, subfoveal scleral thickness were measured on spectral domain optical coherence tomography. Intraclass correlation coefficients of MSA measurement would be evaluated. Multiple linear regression analysis was used to analyze the associated factors with MSA.ResultsIn total, 135 eyes of 92 patients were enrolled. The mean age was 64.73 ± 10.84 years. Mean MSA on UWF image was 279.67 ± 71.70 mm2. Intraclass correlation coefficients of MSA measurement was 0.965 (95% confidence interval [CI], 0.946 to 0.977; p < 0.001). In the multiple linear regression analysis, after adjusting for subfoveal choroidal thickness, best-corrected visual acuity, central foveal thickness, and subfoveal scleral thickness, the factors independently related to MSA were axial length (β = 8.352; 95% CI, 3.306 to 13.398; p = 0.001), sex (β = −26.673; 95% CI, −51.759 to −1.586; p = 0.037), age (β = 1.184; 95% CI, 0.020 to 2.348; p = 0.046).ConclusionsIt is feasible to measure MSA on UWF image. Female, longer axial length, and older age may indicate larger MSA.  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