全文获取类型
收费全文 | 1268篇 |
免费 | 87篇 |
国内免费 | 148篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 63篇 |
妇产科学 | 6篇 |
基础医学 | 90篇 |
口腔科学 | 20篇 |
临床医学 | 189篇 |
内科学 | 296篇 |
皮肤病学 | 31篇 |
神经病学 | 37篇 |
特种医学 | 308篇 |
外科学 | 178篇 |
综合类 | 26篇 |
预防医学 | 54篇 |
眼科学 | 33篇 |
药学 | 116篇 |
1篇 | |
肿瘤学 | 54篇 |
出版年
2023年 | 3篇 |
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 9篇 |
2018年 | 19篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 13篇 |
2014年 | 20篇 |
2013年 | 36篇 |
2012年 | 17篇 |
2011年 | 26篇 |
2010年 | 42篇 |
2009年 | 47篇 |
2008年 | 32篇 |
2007年 | 121篇 |
2006年 | 26篇 |
2005年 | 42篇 |
2004年 | 17篇 |
2003年 | 20篇 |
2002年 | 25篇 |
2001年 | 28篇 |
2000年 | 18篇 |
1999年 | 33篇 |
1998年 | 88篇 |
1997年 | 82篇 |
1996年 | 78篇 |
1995年 | 64篇 |
1994年 | 47篇 |
1993年 | 54篇 |
1992年 | 22篇 |
1991年 | 24篇 |
1990年 | 30篇 |
1989年 | 59篇 |
1988年 | 35篇 |
1987年 | 41篇 |
1986年 | 29篇 |
1985年 | 26篇 |
1984年 | 27篇 |
1983年 | 18篇 |
1982年 | 28篇 |
1981年 | 15篇 |
1980年 | 18篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 20篇 |
1976年 | 31篇 |
1975年 | 14篇 |
1970年 | 2篇 |
1968年 | 3篇 |
排序方式: 共有1503条查询结果,搜索用时 15 毫秒
1.
2.
The Hemodynamic Mechanisms of Lung Injury and Systemic Inflammatory Response Following Brain Death in the Transplant Donor 总被引:7,自引:2,他引:5
Vassilios S. Avlonitis Christopher H. Wigfield John A. Kirby John H. Dark 《American journal of transplantation》2005,5(4):684-693
Brain-dead donors are the major source of lungs for transplantation. Brain death is characterized by two hemodynamic phases. Initially, massive sympathetic discharge results in a hypertensive crisis. This is followed by neurogenic hypotension. Up-regulation of pro-inflammatory mediators occurs in all organs and lung injury develops; this can adversely affect graft function post-transplantation. The mechanisms of the systemic and lung inflammation are unknown. We hypothesized that the hemodynamic changes are responsible for these inflammatory phenomena. Brain death was induced by intra-cranial balloon inflation in rats. This resulted in hypertensive crisis, followed by hypotension. There was a significant increase in blood neutrophil CD11b/CD18 expression and pro-inflammatory cytokine levels in serum and bronchoalveolar lavage, compared with control animals. Rupture of the capillary-alveolar membrane was demonstrated by electron microscopy. Elimination of the hypertensive response by α-adrenergic antagonist pre-treatment prevented inflammatory lung injury, reduced the systemic inflammatory markers and preserved capillary-alveolar membrane integrity. Correction of the neurogenic hypotension with noradrenaline ameliorated the systemic inflammatory response and improved oxygenation. We conclude that the sympathetic discharge triggers systemic and lung inflammation, which can be further enhanced by neurogenic hypotension. Management of the brain-dead donor with early anti-inflammatory treatment and vasoconstrictors is warranted. 相似文献
3.
Intestinal schistosomiasis japonica: CT-pathologic correlation 总被引:1,自引:0,他引:1
Lee RC; Chiang JH; Chou YH; Rubesin SE; Wu HP; Jeng WC; Hsu CC; Tiu CM; Chang T 《Radiology》1994,193(2):539
4.
5.
6.
The patellofemoral joint was imaged with magnetic resonance (MR) in the axial plane while the knee was positioned from 0 degrees to 32 degrees of flexion (nine positions). These multiple sequential images obtained within the early phases of flexion of the knee were viewed in a "cine-loop" format, producing a kinematic study that clearly demonstrated the relationship of the patella to the trochlear groove. Four healthy subjects and one patient with known bilateral subluxing patellae were studied. The preliminary results suggest that kinematic MR imaging of the patellofemoral joint is potentially useful for the evaluation of patellar tracking abnormalities. 相似文献
7.
Dark ML Perelman LT Itzkan I Schaffer JL Field MS 《Physics in medicine and biology》2000,45(2):529-539
Knee meniscus is a hydrated tissue; it is a fibrocartilage of the knee joint composed primarily of water. We present results of interferometric surface monitoring by which we measure physical properties of human knee meniscal cartilage. The physical response of biological tissue to a short laser pulse is primarily thermomechanical. When the pulse is shorter than characteristic times (thermal diffusion time and acoustic relaxation time) stresses build and propagate as acoustic waves in the tissue. The tissue responds to the laser-induced stress by thermoelastic expansion. Solving the thermoelastic wave equation numerically predicts the correct laser-induced expansion. By comparing theory with experimental data, we can obtain the longitudinal speed of sound, the effective optical penetration depth and the Grüneisen coefficient. This study yields information about the laser tissue interaction and determines properties of the meniscus samples that could be used as diagnostic parameters. 相似文献
8.
9.
Marrow regeneration after mechanical depletion 总被引:1,自引:0,他引:1
The origin of marrow regeneration after mechanical depletion was reinvestigated in mouse chimeras. The results were compatible with the local origin of stem cells from remnants of incompletely removed marrow, but not with their origin from a common precursor of both bone and hemopoietic cell lines. In transplanted femurs depleted by a modified technique of in vivo evacuation of marrow, hemopoietic regeneration failed to occur. The presence of hemopoietic stem cells in the Haversian canals was thus excluded. The demonstration of ample hemopoiesis with minimal bone formation in nondepleted controls in which bone marrow initially became necrotic provided new evidence that osteogenesis was not a prerequisite of hemopoietic regeneration. 相似文献
10.
A 15 year old boy with autoimmune polyendocrinopathy-candidosis-ectodermal dystrophy syndrome suffered recurrent episodes of severe intractable diarrhoea, steatorrhoea, and hypocalcaemia. The only treatment modality, which controlled the malabsorption syndrome, was immunosuppression with intravenous high dose methylprednisolone and oral methotrexate maintenance therapy. 相似文献