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   7621篇
  免费   601篇
  国内免费   22篇
耳鼻咽喉   60篇
儿科学   264篇
妇产科学   154篇
基础医学   1082篇
口腔科学   127篇
临床医学   808篇
内科学   1622篇
皮肤病学   183篇
神经病学   760篇
特种医学   171篇
外科学   733篇
综合类   74篇
一般理论   12篇
预防医学   712篇
眼科学   136篇
药学   499篇
中国医学   13篇
肿瘤学   834篇
  2024年   7篇
  2023年   107篇
  2022年   169篇
  2021年   358篇
  2020年   243篇
  2019年   305篇
  2018年   309篇
  2017年   253篇
  2016年   284篇
  2015年   269篇
  2014年   364篇
  2013年   442篇
  2012年   692篇
  2011年   632篇
  2010年   325篇
  2009年   328篇
  2008年   497篇
  2007年   479篇
  2006年   425篇
  2005年   396篇
  2004年   332篇
  2003年   301篇
  2002年   260篇
  2001年   54篇
  2000年   31篇
  1999年   40篇
  1998年   38篇
  1997年   22篇
  1996年   26篇
  1995年   18篇
  1994年   21篇
  1993年   21篇
  1992年   19篇
  1991年   9篇
  1990年   7篇
  1989年   9篇
  1988年   10篇
  1987年   6篇
  1986年   8篇
  1985年   10篇
  1984年   6篇
  1983年   8篇
  1982年   12篇
  1981年   12篇
  1980年   9篇
  1979年   9篇
  1976年   4篇
  1969年   6篇
  1954年   3篇
  1926年   3篇
排序方式: 共有8244条查询结果,搜索用时 31 毫秒
1.
Collagens are the most abundant proteins in the extracellular matrix. They provide a framework to build organs and tissues and give structural support to make them resistant to mechanical load and forces. Several intra‐ and extracellular modifications are needed to make functional collagen molecules, intracellular post‐translational modifications of proline and lysine residues having key roles in this. In this article, we provide a review on the enzymes responsible for the proline and lysine modifications, that is collagen prolyl 4‐hydroxylases, 3‐hydroxylases and lysyl hydroxylases, and discuss their biological functions and involvement in diseases.  相似文献   
2.
3.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
4.
5.
Purpose

The development of Laparoscopic Linear Endostaplers (LLES) is crucial in minimally invasive approaches in bariatric surgery, but there have been very few published studies comparing 6-row LLES in Laparoscopic Sleeve Gastrectomy (LSG). The objective of this study was to compare two 6-row LLES in LSG.

Methods

A total of 60 patients were prospectively randomized to undergo LSG with either Medtronic Endo GIA? Tri-Staple technology (MTS) or AEON ? Endostapler(Lexington Medical) LLES. The measured parameters included patient demographics, comorbidity indices, LLES and specimen characteristics, postoperative symptoms, hospital stay, and total adverse events (AEs). Intraoperative bleeding was evaluated using five laparoscopic and corresponding endoscopic images of staple line before clip application, compared with a 1–5 Visual Analogue Scale (VAS), assessed by an independent bariatric surgeon who was blinded to the LLES used. Images of all cases were reviewed on the same day to increase test–retest reliability.

Results

Both groups were similar in patient demographics. Compared to MTS, AEON LLES group had significantly lower bleeding VAS scores in 4/5 laparoscopic images (pre-pyloric: 1.7?±?0.7 vs. 2.36?±?0.76, p?=?0.0007, mid-sleeve: 1.46?±?0.62 vs. 1.86?±?0.68, p?=?0.019, proximal sleeve: 1.6?±?0.77 vs. 2.0?±?0.83, p?=?0.038, gastro-esophageal junction: 1.43?±?0.67 vs. 1.86?±?0.77, p?=?0.014) and 3/5 endoscopic images (pre-pyloric: 1.56?±?0.56 vs. 2.36?±?0.76, p?=?0.006, incisura: 1.66?±?0.54 vs. 2.0?±?0.52, p?=?0.021, mid-sleeve: 1.63?±?0.49 vs. 2.0?±?0.45, p?=?0.005). There was no statistical difference in other parameters.

Conclusion

Both devices were equally safe and effective in terms of LLES and specimen characteristics, patient symptoms, hospital stay, and AEs. Bleeding VAS scores were significantly lower, favoring the AEON LLES.

Graphical abstract
  相似文献   
6.
7.
8.
9.
The objectives of this study were to systematically review and meta-analyze the research literature on the association of common neurological disorders and violence. Keywords relating to neurological disorders and violence were searched between 1966 and August 2008. Case–control and cohort studies were selected. Odds ratios of violence risk in particular disorders compared with controls were combined using fixed-effects meta-analysis with the data presented in forest plots. Sensitivity analyses were conducted to identify possible differences in risk estimates across surveys. Information on risk factors for violence was extracted if replicated in more than one study. Nine studies were identified that compared the risk of violence in epilepsy or traumatic brain injury compared with unaffected controls. For the epilepsy studies, the overall pooled odds ratio for violent outcomes was 0.67 [95% confidence interval (CI) 0.46–0.96]. For traumatic brain injury, the odds ratio was 1.66 (95% CI 1.12–2.31). An additional 11 case–control studies investigated factors associated with violence in epilepsy and traumatic brain injury. It was not possible to meta-analyze these data. Comorbid psychopathology was associated with violence. Data on other neurological conditions was limited and unreplicated. In conclusion, although the evidence was limited and methodological quality varied, epilepsy and traumatic brain injury appeared to differ in their risk of violence compared with control populations. Longitudinal studies are required to replicate this review’s provisional findings that epilepsy is inversely associated with violence and that brain injury modestly increases the risk, and further research is needed to provide information on a broader range of risk factors.  相似文献   
10.
An antiserum to the purified porcine outer acrosomal membrane (OAM) was raised in female Balb/c mice and was characterized by means of an indirect ELISA. The hyperimmune serum reacted selectively with the acrosomal cap of the sperm head and showed an extremely good cross reactivity with bull and human spermatozoa when assayed by indirect immunofluorescence. Immunoelectron microscopy using the protein A-gold method further confirmed the specificity of the anti-OAM-antiserum for the OAM. In an effort to identify the OAM antigens recognized by the hyperimmune serum and to analyse the extent of cross reactivity on a molecular level, the SDS-extractable proteins were separated by SDS-PAGE, transblotted and immunoprinted using an 125J-conjugated anti-mouse-antibody. To facilitate functional and structural analysis of distinct OAM-proteins monoclonal antibodies were generated by hybridization of mouse myeloma cells with the splenocytes of female Balb/c mice immunized with the purified OAM. One fusion resulted in about 100 anti-OAM-antibodies secreting hybridoma cultures, of which about 30% showed cross reaction with human and bull spermatozoa. Four stable cell lines were selected for this study secreting antibodies directed against the outer acrosomal membrane of boar spermatozoa. Whereas the polyclonal immune mouse serum stained the entire acrosomal cap, the four hybridoma antibodies generated a patch-work-like immunofluorescence pattern over the acrosome. HPLC-ELISA of the solubilized OAM revealed first information on the nature of the corresponding membrane antigen.  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