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   625篇
  免费   27篇
  国内免费   14篇
儿科学   44篇
妇产科学   4篇
基础医学   61篇
口腔科学   17篇
临床医学   108篇
内科学   93篇
皮肤病学   8篇
神经病学   14篇
特种医学   191篇
外科学   31篇
综合类   32篇
预防医学   6篇
眼科学   2篇
药学   43篇
肿瘤学   12篇
  2020年   2篇
  2019年   2篇
  2018年   3篇
  2017年   3篇
  2016年   5篇
  2015年   5篇
  2014年   15篇
  2013年   12篇
  2012年   3篇
  2011年   7篇
  2010年   13篇
  2009年   18篇
  2008年   4篇
  2007年   16篇
  2006年   8篇
  2005年   11篇
  2004年   4篇
  2003年   11篇
  2002年   4篇
  2001年   8篇
  2000年   3篇
  1999年   20篇
  1998年   39篇
  1997年   47篇
  1996年   38篇
  1995年   39篇
  1994年   23篇
  1993年   26篇
  1992年   14篇
  1991年   20篇
  1990年   16篇
  1989年   13篇
  1988年   23篇
  1987年   23篇
  1986年   20篇
  1985年   18篇
  1984年   8篇
  1983年   8篇
  1982年   18篇
  1981年   12篇
  1980年   22篇
  1979年   4篇
  1978年   12篇
  1977年   22篇
  1976年   12篇
  1975年   8篇
  1974年   1篇
  1963年   2篇
  1943年   1篇
排序方式: 共有666条查询结果,搜索用时 0 毫秒
101.
102.

Background  

The scaphoid bone is the most commonly fractured of the carpal bones. In the Netherlands 90% of all carpal fractures is a fracture of the scaphoid bone. The scaphoid has an essential role in functionality of the wrist, acting as a pivot. Complications in healing can result in poor functional outcome. The scaphoid fracture is a troublesome fracture and failure of treatment can result in avascular necrosis (up to 40%), non-union (5-21%) and early osteo-arthritis (up to 32%) which may seriously impair wrist function. Impaired consolidation of scaphoid fractures results in longer immobilization and more days lost at work with significant psychosocial and financial consequences.  相似文献   
103.

Background and purpose:

We determined if chronic sympatho-inhibition with rilmenidine has functional significance for the kidney by altering responses of renal blood flow (RBF) and plasma renin activity (PRA) to stress and acute hypotension in rabbits with renovascular hypertension.

Experimental approach:

RBF to each kidney and renal sympathetic nerve activity (RSNA) to the left kidney were measured in rabbits in which a renal artery clip induced hypertension (2K1C) and in sham-operated rabbits. After 2 weeks, a subcutaneous minipump was implanted to deliver rilmenidine (2.5 mg·kg−1·day−1) to 2K1C rabbits for 3 weeks.

Key results:

After 5 weeks of renal artery stenosis, mean arterial pressure (MAP) was 23% higher and PRA 3-fold greater than in sham-operated rabbits. Blood flow and renal vascular conductance in the stenosed kidney were lower (−75% and −80%) compared with sham, and higher in the non-clipped kidney (68% and 39%). Responses of RBF and PRA to hypotension were similar in 2K1C and sham rabbits. Airjet stress evoked a greater increase in MAP in 2K1C rabbits than sham controls. Chronic rilmenidine normalized MAP, reduced RSNA and PRA, and did not reduce RBF in the stenosed kidney. Responses of RBF (clipped and non-clipped kidney), RSNA and PRA to hypotension and airjet were little affected by rilmenidine.

Conclusions and implications:

Our observations suggest that chronic sympatho-inhibition is an effective antihypertensive therapy in renovascular hypertension. It normalizes MAP and reduces basal PRA without compromising blood flow in the stenosed kidney or altering responses of MAP, haemodynamics and PRA to acute hypotension and stress.  相似文献   
104.
Burren CP, Wanek D, Mohan S, Cohen P, Guevara-Aguirre J, Rosenfeld RG. Serum levels of insulin-like growth factor binding proteins in Ecuadorean children with growth hormone insensitivity. Acta Pædiatr 1999; Suppl 428: 185–91. Stockholm. ISSN 0803–5326
Although insulin-like growth factor binding proteins (IGFBPs) are known to be important modulators of the action of insulin-like growth factors (IGFs), regulation of their production in vivo is not completely understood. Serum concentrations of IGFBP-3, -4 and -5 and acid-labile subunit (ALS) were therefore examined in 20 children with growth hormone (GH) insensitivity before and after 6 months of therapy with recombinant human IGF-I (80 or 120 ug/kg twice daily). The IGFBP concentrations in these children were compared with those in 62 GH-deficient children receiving GH therapy for 3 months. Serum levels of IGFBP-3, -4 and -5 and ALS all increased significantly ( p < 0.0001) in GH-deficient children in response to GH therapy, whereas no significant increases occurred in the children with GH insensitivity. These findings indicate that GH is responsible for the regulation of serum levels of IGFBP-3, -4 and -5 and ALS, and that IGF-I does not directly regulate the concentrations of these circulating IGFBPs. □ Growth hormone, growth hormone insensitivity, insulin-like growth factor I, insulin-like growth factor binding protein  相似文献   
105.
106.
Hwa V, Oh Y, Rosenfeld RG. Insulin-like growth factor binding proteins: a proposed superfamily. Acta Pzdiatr 1999; Suppl 428:37-45. Stockholm. ISSN 0803-5326
The conventional concept is that the insulin-like growth factor binding proteins (IGFBPs) are cysteine-rich proteins, with conserved N- and C-domains, that are capable of binding insulin-like growth factors (IGFs) with high affinity. This dogma was recently challenged by the discovery of a group of cysteine-rich proteins that share important structural similarities with the IGFBPs, but have demonstrably lower affinity for IGFs. It is therefore proposed that these IGFBP-related proteins (IGFBP-rPs) and the IGFBPs constitute an IGFBP superfamily. We speculate that the IGFBP superfamily is derived from an ancestral gene/protein that was critically involved in the regulation of cell growth and was capable of binding IGF peptides. Over the course of evolution, some members (IGFBPs) evolved into high-affinity IGF binders and others (IGFBP-rPs) into low-affinity IGF binders, thereby conferring on the IGFBP superfamily the ability to influence cell growth by both IGF-dependent and IGF-independent means. 0 Insulin-like growth factor binding protein, insulin-like growth factor binding protein-related protein, superfamily  相似文献   
107.
108.
The interosseous nerve of birds innervates a string of Herbst corpuscles located near the interosseous membrane between the tibia and fibula. Fibre composition of this nerve was assessed including both myelinated and unmyelinated axons. The diameter of the whole nerve is ∼100 μm. Complete data were obtained for 3 nerves. The mean total number of myelinated fibres and unmyelinated axons was 2872±53. The mean number of myelinated fibres was 280±20 and that for unmyelinated axons was 2600±47. There was a broad distribution of diameters for myelinated fibres ranging from ∼2 μm to 10 μm with a distinct peak at ∼3–5 μm and a less prominent second peak at 6–8 μm. Similarly, myelin sheath thickness distribution showed 2 peaks, one at 0.6–0.8 μm and another at 1.4–1.6 μm. It is suggested that the group represented by the second peak innervates the Herbst corpuscles. The group of smaller myelinated fibres and the unmyelinated axons are assumed to innervate other types of receptors, some of which may be nociceptors.  相似文献   
109.
110.
Background. In tropical primary health care, essential drugs should be safe, effective, and as inexpensive as possible. To treat the very common dermatophyte infections of the skin, one may use inexpensive Whitfield's preparations, more expensive topical imidazole derivatives, or extremely expensive oral antifungals. Because a cream base is felt to be more appropriate than an ointment in tropical conditions, we wanted to compare the effectiveness of Whitfield's cream and a topical imidazole derivative in field conditions in the tropics. Methods. A double-blind trial was performed involving 153 patients with a dermatophyte infection of the skin in Karonga District, Northern Malawi, including 25 patients who were Hiv-i-seropositive, comparing Whitfieid's cream with clotrimazole cream. Results. 75 patients were treated with Whitfield's cream and 78 with clotrimazole cream for a period of 6 weeks. Cure rates ranged from 80% to over 90% depending on the definition of cure. If positive cultures after treatment were used as criterion for treatment failure, six were found in each treatment group. One in each treatment failure group was an mv-i-seropositive patient. Conclusions. The great majority of patients in the tropics with a dermatophyte infection of the skin can be cured with a topical antimycotic preparation and do not need expensive oral therapy. This also proved to be valid for HIV-I-seropositive patients. Whitfield's cream and clotrimazole cream are both very effective. The lower cost makes Whitfield's cream the treatment of choice in dermatophyte infections of the skin in tropical primary health care.  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