全文获取类型
收费全文 | 4476篇 |
免费 | 25篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 49篇 |
儿科学 | 1051篇 |
妇产科学 | 30篇 |
基础医学 | 347篇 |
口腔科学 | 20篇 |
临床医学 | 372篇 |
内科学 | 701篇 |
皮肤病学 | 19篇 |
神经病学 | 175篇 |
特种医学 | 174篇 |
外科学 | 598篇 |
综合类 | 106篇 |
预防医学 | 331篇 |
眼科学 | 44篇 |
药学 | 184篇 |
中国医学 | 20篇 |
肿瘤学 | 324篇 |
出版年
2019年 | 88篇 |
2018年 | 181篇 |
2017年 | 176篇 |
2016年 | 177篇 |
2015年 | 46篇 |
2014年 | 71篇 |
2013年 | 73篇 |
2012年 | 218篇 |
2011年 | 1863篇 |
2010年 | 718篇 |
2009年 | 306篇 |
2008年 | 132篇 |
2007年 | 48篇 |
2006年 | 18篇 |
2005年 | 10篇 |
2004年 | 9篇 |
2003年 | 10篇 |
1999年 | 8篇 |
1998年 | 33篇 |
1997年 | 26篇 |
1996年 | 43篇 |
1995年 | 45篇 |
1994年 | 44篇 |
1993年 | 23篇 |
1992年 | 12篇 |
1991年 | 5篇 |
1989年 | 3篇 |
1985年 | 3篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 8篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 14篇 |
1973年 | 8篇 |
1970年 | 3篇 |
1965年 | 4篇 |
1964年 | 12篇 |
1963年 | 4篇 |
1962年 | 5篇 |
1961年 | 12篇 |
1960年 | 5篇 |
1959年 | 7篇 |
1958年 | 4篇 |
1921年 | 2篇 |
1914年 | 2篇 |
1911年 | 2篇 |
1908年 | 3篇 |
排序方式: 共有4545条查询结果,搜索用时 15 毫秒
951.
952.
Arnaud D��Argembeau Doroth��e Feyers Steve Majerus Fabienne Collette Martial Van der Linden Pierre Maquet Eric Salmon 《Social cognitive and affective neuroscience》2008,3(3):244-252
The processing of personal changes across time and the ability to differentiate between representations of present and past selves are crucial for developing a mature sense of identity. In this study, we explored the neural correlates of self-reflection across time using functional magnetic resonance imaging (fMRI). College undergraduates were asked to reflect on their own psychological characteristics and those of an intimate other, for both the present time period (i.e. at college) and a past time period (i.e. high school years) that involved significant personal changes. Cortical midline structures (CMS) were commonly recruited by the four reflective tasks (reflecting on the present self, past self, present other and past other), relative to a control condition (making valence judgments). More importantly, however, the degree of activity in CMS also varied significantly according to the target of reflection, with the ventral and dorsal medial prefrontal cortex and the posterior cingulate cortex being more recruited when reflecting on the present self than when reflecting on the past self or when reflecting on the other person. These findings suggest that CMS may contribute to differentiate between representations of present and past selves. 相似文献
953.
954.
955.
L S Schmidt K Grell K Frederiksen C Johansen K Schmiegelow J Sch��z 《British journal of cancer》2009,100(1):185-187
We investigated possible seasonal variation of births among children <20 years with a central nervous system tumour in Denmark (N=1640), comparing them with 2 582 714 children born between 1970 and 2003. No such variation was seen overall, but ependymoma showed seasonal variation. 相似文献
956.
The phosphatidylinositol-3-kinase (PI3K)/Akt signalling pathway is frequently deregulated in pancreatic cancers, and is believed to be an important determinant of their biological aggression and drug resistance. NVP-BEZ235 is a novel, dual class I PI3K/mammalian target of rapamycin (mTor) inhibitor undergoing phase I human clinical trials. To simulate clinical testing, the effects of NVP-BEZ235 were studied in five early passage primary pancreatic cancer xenografts, grown orthotopically. These tumours showed activated PKB/Akt, and increased levels of at least one of the receptor tyrosine kinases that are commonly activated in pancreatic cancers. Pharmacodynamic effects were measured following acute single doses, and anticancer effects were determined in separate groups following chronic drug exposure. Acute oral dosing with NVP-BEZ235 strongly suppressed the phosphorylation of PKB/Akt, followed by recovery over 24 h. There was also inhibition of Ser235/236 S6 ribosomal protein and Thr37/46 4E-BP1, consistent with the effects of NVP-BEZ235 as a dual PI3K/mTor inhibitor. Chronic dosing with 45 mg kg−1 of NVP-BEZ235 was well tolerated, and produced significant tumour growth inhibition in three models. These results predict that agents targeting the PI3K/Akt/mTor pathway might have anticancer activity in pancreatic cancer patients, and support the testing of combination studies involving chemotherapy or other molecular targeted agents. 相似文献
957.
958.
959.
Tumours of the upper aerodigestive tract cause malnutrition in the majority of ENT cancer patients. This situation is complicated by multimodal treatment regimens (including surgery and/or irradiation). The resulting malnutrition is a disease entity in its own right and requires special treatment concepts. Effective screening tools (NRS?2002) need to be introduced and data such as body mass index and bioimpedance analysis need to be gathered. The nutrition plan for individual ENT patients differs according to the grade of malnutrition and dysphagia. Oral nutrition should always form the basis of any nutrition programme, such that logopedic therapy is required in all cases of dysphagia. Artifical, oral high-energy nutrition is a pharmacological procedure as well as enteral feeding via PEG or PEJ. Partial or total parenteral nutrition (central venous access) should be restricted to crisis interventions or fast-track regimens. 相似文献
960.