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   429篇
  免费   29篇
耳鼻咽喉   22篇
儿科学   25篇
妇产科学   6篇
基础医学   53篇
口腔科学   3篇
临床医学   27篇
内科学   77篇
皮肤病学   7篇
神经病学   11篇
特种医学   10篇
外科学   47篇
综合类   14篇
预防医学   10篇
眼科学   17篇
药学   87篇
中国医学   1篇
肿瘤学   41篇
  2022年   3篇
  2021年   10篇
  2020年   5篇
  2019年   4篇
  2018年   8篇
  2017年   7篇
  2016年   12篇
  2015年   7篇
  2014年   15篇
  2013年   30篇
  2012年   16篇
  2011年   32篇
  2010年   9篇
  2009年   9篇
  2008年   28篇
  2007年   33篇
  2006年   19篇
  2005年   16篇
  2004年   21篇
  2003年   19篇
  2002年   20篇
  2001年   11篇
  2000年   10篇
  1999年   11篇
  1998年   6篇
  1997年   5篇
  1993年   3篇
  1992年   4篇
  1991年   4篇
  1990年   2篇
  1988年   4篇
  1987年   3篇
  1986年   3篇
  1985年   6篇
  1982年   2篇
  1981年   3篇
  1979年   3篇
  1976年   3篇
  1974年   4篇
  1973年   3篇
  1972年   2篇
  1969年   6篇
  1968年   2篇
  1967年   2篇
  1966年   5篇
  1962年   2篇
  1960年   2篇
  1923年   2篇
  1915年   2篇
  1892年   1篇
排序方式: 共有458条查询结果,搜索用时 15 毫秒
21.
Recent studies have highlighted the immunostimulatory nature of nucleic acids and the enhancement of such immunostimulation when nucleic acids are complexed to cationic liposomes to form cationic-lipid-nucleic-acid-complexes or lipoplexes. While such immunostimulation may have deleterious consequences for nucleic acid delivery, especially in the field of gene therapy, it may be harnessed for efficacious usage against the various forms of cancer.  相似文献   
22.
An unusual case of Polyostotic Fibrous Displasia involving maxilla, ethmoid, sphenoid and frontal sinuses is reported for clinical interest. The clinical feature, radiological findings and treatment have been discussed.  相似文献   
23.
24.
This paper reports on 80 consecutive cases of alcoholic psychoses and alcoholism admitted to the University Hospital, Kuala Lumpur, Malaya, during a two year period.  相似文献   
25.
26.
27.
Summary. Direct intracerebral administration of sonic hedgehog (SHH) reduces 6-OHDA and MPTP toxicity to nigral dopaminergic cells in rats and primates. To determine whether transfection of the DNA sequence for SHH using viral vectors also protects against 6-OHDA toxicity, a type 2 adeno- associated virus (AAV) incorporating 600 base pairs of N-terminal SHH DNA was generated to induce SHH expression in rat striatum.AAV-SHH was injected into the striatum, 3 weeks prior to the initiation of an unilateral partial 6-OHDA nigro-striatal lesion. Animals receiving 4×107 viral particles of AAV-SHH showed a reduction in (+)-amphetamine induced ipsilateral turning over 4 weeks, when compared to animals receiving vehicle or a LacZ encoding vector. Following vehicle or AAV-LacZ administration, 6-OHDA caused a marked loss of striatal dopamine content and nigral tyrosine hydroxylase (TH) immunopositive cells. Following treatment with 4×107 viral particles of AAV-SHH the loss of striatal dopamine content was reduced and there was marked preservation of nigral dopaminergic cells. However, administration of 4×108 particles of AAV-SHH did not cause a significant change in (+)-amphetamine-induced rotation, striatal dopamine levels or the number of nigral TH immunoreactive cells following 6-OHDA lesioning compared to vehicle or AAV-LacZ treated animals.The results show that SHH delivered via a viral vector can protect dopaminergic neurons against 6-OHDA toxicity and suggest that this could be developed into a novel treatment for PD. However, the effects maybe dose limited due to uncoupling of hedgehog receptor signalling at higher levels of SHH expression.Present address: Synta Pharmaceuticals Corp., Lexington, MA, USA  相似文献   
28.
29.
30.
Sonic hedgehog (SHH) has trophic actions on dopaminergic cell cultures and protects them from MPP(+) toxicity but its in vivo actions have not been explored. We now investigate the effects of unilateral supranigral administration of SHH on nigro-striatal function in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated common marmosets. SHH (0.1 or 1.0 microg) or vehicle was stereotaxically injected into the region of the right substantia nigra twice with an interval of 5 weeks between administrations. The first or second administration of low dose SHH (0.1 microg) did not significantly improve motor disability or locomotor activity compared to time-matched vehicle-treated animals. There was, however, an approximately 30% improvement in both motor disability and locomotor activity following the first administration of high dose SHH (1.0 microg). No further improvements occurred following the second high dose SHH treatment. Acute oral administration of L-3,4-dihydroxyphenylalanine (L-DOPA) produced a smaller increase in locomotor activity and greater reversal of motor disability in animals treated with SHH than occurred in vehicle-treated common marmosets. In the substantia nigra pars compacta, ipsilateral to SHH administration, the number of tyrosine hydroxylase-positive neurones was increased by 21% (P > 0.05) and 57% (P < 0.05) in low and high dose SHH groups respectively compared to the untreated contralateral hemisphere. There was no difference in the number of glial fibrillary acidic protein-positive cells. SHH may improve nigro-striatal function by restoring tyrosine hydroxylase positivity. This is reflected by an improvement in basal disability and a reduction in the lesion-induced response to L-DOPA.  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