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   68787篇
  免费   5074篇
  国内免费   467篇
耳鼻咽喉   861篇
儿科学   2157篇
妇产科学   1607篇
基础医学   9401篇
口腔科学   660篇
临床医学   7817篇
内科学   13255篇
皮肤病学   1770篇
神经病学   6470篇
特种医学   2223篇
外科学   7712篇
综合类   498篇
现状与发展   1篇
一般理论   91篇
预防医学   7615篇
眼科学   1367篇
药学   5015篇
中国医学   319篇
肿瘤学   5489篇
  2024年   65篇
  2023年   632篇
  2022年   1232篇
  2021年   2496篇
  2020年   1484篇
  2019年   2296篇
  2018年   2484篇
  2017年   1957篇
  2016年   2317篇
  2015年   2715篇
  2014年   3526篇
  2013年   4320篇
  2012年   6416篇
  2011年   6249篇
  2010年   3604篇
  2009年   2958篇
  2008年   4733篇
  2007年   4530篇
  2006年   4170篇
  2005年   3850篇
  2004年   3265篇
  2003年   2791篇
  2002年   2436篇
  2001年   452篇
  2000年   372篇
  1999年   388篇
  1998年   403篇
  1997年   309篇
  1996年   236篇
  1995年   198篇
  1994年   144篇
  1993年   133篇
  1992年   108篇
  1991年   108篇
  1990年   80篇
  1989年   94篇
  1988年   89篇
  1987年   65篇
  1986年   52篇
  1985年   47篇
  1984年   53篇
  1983年   60篇
  1981年   30篇
  1980年   37篇
  1979年   35篇
  1978年   44篇
  1977年   42篇
  1976年   26篇
  1975年   28篇
  1973年   28篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
993.
994.
Anatomical Science International - Variants of the axillary artery and brachial plexus were found bilaterally in the axilla of an 86-year-old Asian female. On the left, the cadaver donor had a high...  相似文献   
995.
Purpose: The aim of this study was to compare survival outcomes of open radical hysterectomy and minimally invasive radical hysterectomy (MIS) in early stage cervical cancer.Methods: A retrospective analysis of 148 patients with stage IB1 - IIA2 cervical cancer who underwent either minimally invasive or open radical hysterectomy. Tumor characteristics, recurrence rate, disease-free survival (DFS), and overall survival (OS) were compared according to surgical approach.Results: In total, 110 and 38 patients were assigned to open surgery and MIS groups. After a medical follow-up of 42.1 months, the groups showed similar survival outcomes (recurrence rate, DFS, and OS). However, in patients with tumor size >2 cm, recurrence rate was significantly higher in MIS group (22.5% vs 0%; p=0.008). And in patients with tumor size >2 cm, MIS group showed significantly poorer DFS than open surgery group (p=0.017), although OS was similar between the two groups (p=0.252).Conclusion: In patients with tumor size >2 cm, MIS was associated with higher recurrence rates and poorer DFS than open surgery. However, in patients with tumor size ≤2 cm, MIS did not seem to compromise oncologic outcomes.  相似文献   
996.
997.
The distribution of cone photoreceptor subtypes (important for color vision and vision quality) varies widely in different carnivore species, but there have been limited studies on bear (ursid) cone distribution. A previous behavioral study suggests that American black bears (Ursus americanus) are dichromatic, indicating that they possess two cone subtypes, although the retinal distribution of cones is unknown. The purpose of this study was to examine the subtype and topography of cones in American black bear retinas to further predict the nature of their color vision and image resolution. We studied 10 eyes from seven individual legally hunted black bears in northeastern North Carolina. Cryosections and retinal wholemounts were labeled using antibodies targeting two cone opsin subtypes: long/medium (L/M) wavelength sensitive and short (S) wavelength sensitive. Cones in fluorescent microscopy images were counted and density maps were created for retinal wholemounts. The black bear retina contains both cone subtypes and L/M cones outnumber S cones by at least 3:1, a finding confirmed in retinal frozen sections. There are higher concentrations of S cones present than typically seen in other carnivores with some evidence for co-expression of L/M and S cones. A cone-dense area centralis is present dorsotemporal to the optic nerve, similar to other carnivores. These results confirm that American black bears are predicted to have a dichromatic vision with high acuity indicated by the presence of a dorsotemporally located area centralis.  相似文献   
998.
International Journal of Legal Medicine - Direct PCR can be used to successfully generate full STR profiles from DNA present on the surface of objects. STR profiles are only of use in cases where a...  相似文献   
999.
International Journal of Legal Medicine - Massively parallel sequencing (MPS) of mitochondrial (mt) DNA allows practitioners the ability to fully resolve heteroplasmic sites. In forensic DNA...  相似文献   
1000.
ObjectiveThe treatment of large aneurysms of the posterior circulation is complicated and remains challenging. We here analyzed our institutional clinical outcomes of large unruptured aneurysms of the posterior circulation. MethodsThis study included 56 patients who presented with a large (>10 mm) unruptured aneurysm of the posterior circulation between 2002 and 2018. ResultsThere were 18 (32.1%) male and 38 (67.9%) female patients, with a mean age of 53.4 years. The most common location was the vertebral artery, followed by the basilar tip and posterior cerebral artery. The median follow-up duration was 29 months. Eighteen patients (32.1%) were treated by transcranial surgery and 38 (67.9%) were treated by endovascular treatment (EVT). Posttreatment complications occurred in 16 patients (28.6%), with there being no significant difference between the transcranial surgery and EVT groups. Complete obliteration was achieved in 30 patients (53.6%), with there being no statistically significant difference between the transcranial surgery and EVT groups. Recurrence occurred in 17 patients (30.4%), and the rate of recurrence was higher in the EVT group than in the transcranial surgery group (39.5% vs. 11.1%, p=0.03). Forty-four (84%) of 56 patients showed a favorable functional outcome. In saccular aneurysm, EVT was negative predictor of worsening of functional status. ConclusionTreatment of these aneurysms harbors an inherent high risk of morbidity. No superiority was found between transcranial surgery and EVT in terms of complications and complete obliteration, but transcranial surgery showed a higher treatment durability than EVT.  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