首页 | 官方网站   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   295篇
  免费   14篇
  国内免费   11篇
医药卫生   320篇
  2023年   1篇
  2022年   2篇
  2021年   1篇
  2018年   6篇
  2017年   1篇
  2016年   5篇
  2015年   1篇
  2014年   1篇
  2013年   6篇
  2012年   4篇
  2011年   1篇
  2010年   9篇
  2009年   8篇
  2008年   2篇
  2007年   8篇
  2006年   4篇
  2005年   3篇
  2004年   9篇
  2003年   3篇
  2002年   3篇
  2001年   7篇
  2000年   1篇
  1999年   3篇
  1998年   16篇
  1997年   18篇
  1996年   17篇
  1995年   16篇
  1994年   17篇
  1993年   15篇
  1991年   1篇
  1990年   3篇
  1989年   10篇
  1988年   13篇
  1987年   14篇
  1986年   17篇
  1985年   23篇
  1984年   8篇
  1983年   13篇
  1982年   10篇
  1981年   2篇
  1980年   3篇
  1978年   2篇
  1977年   4篇
  1976年   5篇
  1975年   2篇
  1966年   1篇
  1963年   1篇
排序方式: 共有320条查询结果,搜索用时 15 毫秒
41.
Aims/IntroductionTo examine the association between cholesterol efflux capacity (CEC) of serum high‐density lipoprotein (HDL) and cognitive function and brain structures in older people with diabetes mellitus.Materials and MethodsParticipants of a randomized placebo‐controlled trial of 27‐month vitamin B12 supplementation in older people with diabetes mellitus, which showed no effect on cognition, were further followed up at month 72. Cognitive tests included the Clinical Dementia Rating scale, Neuropsychological Test Battery in memory, executive function and psychomotor speed. Brain magnetic resonance imaging scans were carried out in a subset at baseline, month 27 and month 45. Fasting serum at baseline, month 9, month 27 and month 72 were analyzed for adenosine triphosphate‐binding cassette transporter A1‐mediated CEC of HDL and apolipoprotein A1 (ApoA1).ResultsSerum HDL cholesterol at baseline was associated with better executive and memory function at follow up. Serum ApoA1 was associated with a better memory Z‐score at month 18. Serum CEC and ApoA1 were not associated with Clinical Dementia Rating scale, Neuropsychological Test Battery, hippocampal volume and white matter disease on magnetic resonance imaging at baseline and whole brain atrophy rates. They were also not associated with cognitive function at month 27 and 72 on multilevel modeling. CEC and ApoA1 decreased significantly from baseline to month 27. Faster decliners in CEC had a greater increase in brain peak width of skeletonized mean diffusivity.ConclusionsHigher serum HDL cholesterol was associated with more favorable changes in memory and executive function in older people with diabetes mellitus. However, this was not due to CEC or ApoA1. A decline in CEC was associated with small vessel disease in the brain.  相似文献   
42.
43.
44.
45.
46.
47.
48.
人参叶中微量新皂甙-La的分离与鉴定   总被引:4,自引:0,他引:4  
前已报道从人参(Panax ginseng C.A.Meyer)叶中分到三种微量新皂甙。在继续研究的基础上,又得到一个微量新皂甙,命名为人参皂甙-La(ginsenoside-La)。人参皂甙-La,无色针晶(MeOH),[α]D~(20)—18.4(Pyridine-d_5)。负离子FAB-MS  相似文献   
49.
50.
Aortic dissection: magnetic resonance imaging   总被引:2,自引:0,他引:2  
Amparo  EG; Higgins  CB; Hricak  H; Sollitto  R 《Radiology》1985,155(2):399-406
Fifteen patients with suspected or known aortic dissection were imaged with magnetic resonance (MR). Thirteen of these patients were eventually shown to have dissection. In most instances the diagnosis was established by aortography and/or computed tomography (CT) prior to the MR study. Surgical proof (6/13) and/or aortographic proof (10/13) were available in 11/13 patients with aortic dissection. MR demonstrated the intimal flap and determined whether the dissection was type A or type B. In addition, MR: differentiated between the true and false lumens; determined the origins of the celiac, superior mesenteric, and renal arteries from the true or false lumen in the cases where the dissection extended into the abdominal aorta (8/12); allowed post-surgical surveillance of the dissection; and identified aortoannular ectasia in the three patients who had Marfan syndrome. In addition to the 13 cases with dissection, there were two cases in whom the diagnosis of dissection was excluded by MR. Our early experience suggests that MR can serve as the initial imaging test in clinically suspected cases of aortic dissection and that the information provided by MR is sufficient to manage many cases. Additionally, MR obviates the use of iodinated contrast media.  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-23

京公网安备 11010802026262号