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   28843篇
  免费   1643篇
  国内免费   115篇
耳鼻咽喉   348篇
儿科学   647篇
妇产科学   554篇
基础医学   3835篇
口腔科学   2104篇
临床医学   2003篇
内科学   6690篇
皮肤病学   574篇
神经病学   2333篇
特种医学   580篇
外科学   4101篇
综合类   250篇
一般理论   9篇
预防医学   2498篇
眼科学   720篇
药学   1814篇
中国医学   194篇
肿瘤学   1347篇
  2023年   206篇
  2022年   407篇
  2021年   1036篇
  2020年   568篇
  2019年   869篇
  2018年   1054篇
  2017年   664篇
  2016年   720篇
  2015年   914篇
  2014年   1272篇
  2013年   1482篇
  2012年   2436篇
  2011年   2461篇
  2010年   1325篇
  2009年   1165篇
  2008年   1945篇
  2007年   1992篇
  2006年   1739篇
  2005年   1612篇
  2004年   1476篇
  2003年   1179篇
  2002年   1119篇
  2001年   299篇
  2000年   227篇
  1999年   259篇
  1998年   245篇
  1997年   163篇
  1996年   111篇
  1995年   104篇
  1994年   98篇
  1993年   75篇
  1992年   118篇
  1991年   101篇
  1990年   96篇
  1989年   91篇
  1988年   92篇
  1987年   86篇
  1986年   77篇
  1985年   67篇
  1984年   58篇
  1983年   61篇
  1982年   52篇
  1981年   46篇
  1980年   33篇
  1979年   27篇
  1978年   37篇
  1977年   33篇
  1976年   29篇
  1974年   25篇
  1973年   35篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
Obesity Surgery - Laparoscopic sleeve gastrectomy (LSG) is increasingly playing a key role in obesity management. Such operations, however, carry complications sometimes including leaks. The...  相似文献   
3.
Background: Extracellular matrix molecular components, previously linked to multisystem syndromes include collagens, fibrillins and laminins. Recently, we described a novel multisystem syndrome caused by the c.9418G>A p.(V3140M) mutation in the laminin alpha-5 (LAMA5) gene, which affects connective tissues of all organs and apparatus in a three generation family. In the same family, we have also reported a myopic trait, which, however, was linked to the Prolyl 4-hydroxylase subunit alpha-2 (P4HA2) gene. Results of investigation on vitreous changes and their pathogenesis are reported in the present study.Materials and Methods: Nineteen family individuals underwent complete ophthalmic examination including best-corrected visual acuity (BCVA), fundus examination, fundus photography, intraocular pressure measurement, axial length measurement using ocular biometry, Goldmann visual field examination, standard electroretinogram, SD-OCT. Segregation analysis of LAMA5 and P4HA2 mutations was performed in enrolled members.Results: The vitreous alterations fully segregated with LAMA5 mutation in both young and adult family members. Slight reduction of retinal thickness and peripheral retinal degeneration in only two patients were reported.Conclusions: In this work we showed that PVD is a common trait of LAMA5 multisystem syndrome, therefore occurring as an age-unrelated trait. We hypothesize that the p.(V3140M) mutation results in a reduction of retinal inner limiting membrane (ILM) stability, leading to a derangement in the macromolecular structure of the vitreous gel, and PVD. Further investigations will be necessary to elucidate the role of wild type and mutated LAMA5 in the pathogenesis of PVD.  相似文献   
4.
5.
Gangliocytic paragangliomas are rare tumors that almost exclusively occur within the second portion of the duodenum. Although these tumors generally have a benign clinical course, they have the potential to recur or metastasize to regional lymph nodes. The case report presented here describes a 57-year-old female patient with melena, progressive asthenia, anemia, and a mass in the second-third portion of the duodenum that was treated by local excision. The patient was diagnosed with a friable bleeding tumor. The histologic analysis showed that the tumor was a 4 cm gangliocytic paraganglioma without a malignant cell pattern. In the absence of local invasion or distant metastasis, endoscopic resection represents a feasible, curative therapy. Although endoscopic polypectomy is currently considered the treatment of choice, it is not recommended if the size of the tumor is > 3 cm and/or there is active or recent bleeding. Patients diagnosed with a gangliocytic paraganglioma should be closely followed-up for possible local recurrence.  相似文献   
6.
7.
8.
9.
10.
Objective:The present study evaluates a training program for fitting different hearing protection devices (HPDs) based on personal attenuation rating (PAR) before, immediately after, and six months after training.Methods:A total of 67 workers from a public university in the city of São Paulo, Brazil, were invited to participate in the measurement of PARs for foam and silicone protectors through the 3M™ E-A-Rfit Validation System. Two evaluations were performed for each protector at each sampling date: one after reading printed material (the package instructions) and another after being trained by an audiologist. The same procedures were repeated after six months. The final sample consisted of 30 individuals. ANOVA was used for statistical analysis.Results:Larger PAR values were observed after training by the audiologist, and smaller values were observed after six months. Then, after re-training, the values increased again. There were no statistically significant differences in PAR among the HPDs tested. Even after the two training sessions, 23 to 27% of the subjects did not obtain adequate PAR values.Conclusion:These findings emphasize the need for continual worker training in the correct fit of earplug HPDs and the importance of longitudinal PAR monitoring. In addition, some workers, despite the training provided, did not adapt to the HPDs used. Therefore, it is essential that other protection methods and/or other HPD types are made available to these individuals.Key words: Hearing, noise-induced hearing loss, occupational health, personal protective equipment, hearing protection devices  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