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   606篇
  免费   33篇
  国内免费   17篇
耳鼻咽喉   3篇
儿科学   42篇
妇产科学   8篇
基础医学   47篇
口腔科学   22篇
临床医学   72篇
内科学   169篇
皮肤病学   3篇
神经病学   30篇
特种医学   81篇
外科学   34篇
综合类   16篇
预防医学   17篇
眼科学   4篇
药学   38篇
中国医学   1篇
肿瘤学   69篇
  2022年   2篇
  2021年   9篇
  2020年   7篇
  2019年   6篇
  2018年   13篇
  2017年   6篇
  2016年   7篇
  2015年   14篇
  2014年   14篇
  2013年   20篇
  2012年   25篇
  2011年   27篇
  2010年   33篇
  2009年   38篇
  2008年   35篇
  2007年   38篇
  2006年   35篇
  2005年   25篇
  2004年   24篇
  2003年   7篇
  2002年   10篇
  2001年   12篇
  2000年   11篇
  1999年   13篇
  1998年   28篇
  1997年   25篇
  1996年   21篇
  1995年   15篇
  1994年   19篇
  1993年   7篇
  1992年   6篇
  1991年   6篇
  1990年   5篇
  1989年   6篇
  1988年   12篇
  1987年   8篇
  1986年   11篇
  1985年   7篇
  1984年   5篇
  1983年   4篇
  1982年   10篇
  1981年   4篇
  1980年   3篇
  1977年   2篇
  1975年   2篇
  1969年   2篇
  1968年   2篇
  1967年   4篇
  1966年   3篇
  1926年   1篇
排序方式: 共有656条查询结果,搜索用时 15 毫秒
651.
Craniometaphyseal dysplasia is an extremely rare, genetic bone-remodeling disorder. Comparable to osteopetrosis, fibrous dysplasia, and other infrequent conditions, craniometaphyseal dysplasia is characterized by progressive diffuse hyperostosis of the neuro- and viscerocranium. Affected patients present with a pathognomonic dysmorphia: macrocephalus, hypertelorism, bulky facial skeleton, and a prominent mandible. Progressive thickening and petrification of the craniofacial bones can continue throughout life, often resulting in neurological symptoms due to obstruction of the cranial nerves in the foramina and therefore immediately requiring neurosurgical interventions to avoid persistent symptoms with severe impairment of function. Treatment is largely infeasible given the lack of suitable tools to perform a craniotomy through the gross calvarial bone. In this paper, the authors present a complete process chain from the CT-based generation of an individual patient's model displaying his pathology to optimized preoperative planning of the skull's shape with a thickness of about 6-7 mm. For concise verification of the surgical plan in an operating room environment, a 3D real-time navigation prototype system was utilized. To guarantee realization of the surgery in a reasonable time frame, the mechanical tools were preoperatively selected for optimizing the ablation rate in porcine and bovine bone, which were comparable to that in the patient. This process chain was developed in a modular way, so that it could be easily adopted completely or partially for other surgical indications. A 21-year-old man was treated according to this sophisticated concept. Skull bone more than 50 mm thick in some regions was reduced to physiological thickness. The patient was thus in a stage that neurosurgical interventions could be performed with a regular risk within a reasonable time of treatment.  相似文献   
652.
Aberrations in the signaling cascade of the epidermal growth factor receptor are common to several solid tumors. Compounds aimed at targeting this pathway have been approved for use by the US Food and Drug Administration for lung, head and neck, pancreas, and colorectal carcinomas. Unfortunately, only the minority of patients treated with this class of agents will have responses or improvements in survival. This article reviews the data on agents that exploit tumor dependency on epidermal growth factor receptor cascade and describes the knowledge on how to discern the appropriate patient population for receiving these agents.  相似文献   
653.
红细胞多态性在DNA水平的分型是输血医学的重大进展,其将对输血服务产生重大影响.最近,国际输血协会和国际血液学标准化委员会就此问题组织三次研讨会结果表明,可为分子血型基因分型设定非常高的标准.随着基因分型用于红细胞多态性研究的报道迅速增加,引起了国际论坛对其进展评价的关注.为了获得必要的信息,该领域的专家被问及以下问题:  相似文献   
654.
655.
The existence of flat adenomas in the colon is well recognized. Whether they represent a distinct disease with a pathogenetic pathway different from that of the classical adenoma-carcinoma sequence in colorectal tumorigenesis and have higher malignant potential remains a matter of debate. To review the epidemiology, clinical features, detection and management of flat and depressed (non-polypoid) colonic neoplasm, we performed a thorough literature review on studies focusing on the prevalence, histological features, genetics, detection and treatment of flat and depressed (non-polypoid) colonic neoplasm. A high percentage of severe dysplasia in flat colonic adenomas has not been consistently demonstrated. Their malignant potential appears to be size-dependent. Flat adenomas are found to have a lower incidence of major genetic abnormalities involved in the classical adenoma-carcinoma sequence and that has raised suspicions that they may have a different pathogenesis. The depressed type of colorectal carcinoma is uncommon but shows more aggressive behavior. More advanced colonoscopic techniques, such as chromoendoscopy, may enhance the detection of small and inconspicuous colonic neoplastic lesions that lack a protruding configuration. It is essential for endoscopists to appreciate the existence and clinical significance of flat and depressed colonic lesions as an important variant of colonic neoplasms so that the goal of reducing colorectal carcinoma incidence by polypectomy can be better achieved.  相似文献   
656.

Background  

Microglia are considered a major target for modulating neuroinflammatory and neurodegenerative disease processes. Upon activation, microglia secrete inflammatory mediators that contribute to the resolution or to further enhancement of damage in the central nervous system (CNS). Therefore, it is important to study the intracellular pathways that are involved in the expression of the inflammatory mediators. Particularly, the role of the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and glycogen synthase kinase-3 (GSK-3) pathways in activated microglia is unclear. Thus, in the present study we investigated the role of Akt and its downstream pathways, GSK-3 and mTOR, in lipopolysaccharide (LPS)-activated primary rat microglia by pharmacological inhibition of these pathways in regard to the expression of cyclooxygenase (COX)-2 and microsomal prostaglandin E synthase-1 (mPGES-1) and to the production of prostaglandin (PG) E2 and PGD2.  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