全文获取类型
收费全文 | 21988篇 |
免费 | 2175篇 |
国内免费 | 1207篇 |
专业分类
耳鼻咽喉 | 155篇 |
儿科学 | 732篇 |
妇产科学 | 317篇 |
基础医学 | 2407篇 |
口腔科学 | 347篇 |
临床医学 | 2855篇 |
内科学 | 3154篇 |
皮肤病学 | 236篇 |
神经病学 | 1105篇 |
特种医学 | 848篇 |
外国民族医学 | 6篇 |
外科学 | 2768篇 |
综合类 | 3375篇 |
现状与发展 | 3篇 |
一般理论 | 3篇 |
预防医学 | 1758篇 |
眼科学 | 433篇 |
药学 | 2147篇 |
18篇 | |
中国医学 | 1115篇 |
肿瘤学 | 1588篇 |
出版年
2024年 | 80篇 |
2023年 | 302篇 |
2022年 | 725篇 |
2021年 | 1039篇 |
2020年 | 774篇 |
2019年 | 674篇 |
2018年 | 792篇 |
2017年 | 724篇 |
2016年 | 640篇 |
2015年 | 946篇 |
2014年 | 1142篇 |
2013年 | 1066篇 |
2012年 | 1542篇 |
2011年 | 1611篇 |
2010年 | 1151篇 |
2009年 | 886篇 |
2008年 | 1130篇 |
2007年 | 1091篇 |
2006年 | 1098篇 |
2005年 | 993篇 |
2004年 | 778篇 |
2003年 | 753篇 |
2002年 | 684篇 |
2001年 | 576篇 |
2000年 | 436篇 |
1999年 | 384篇 |
1998年 | 207篇 |
1997年 | 216篇 |
1996年 | 152篇 |
1995年 | 122篇 |
1994年 | 140篇 |
1993年 | 103篇 |
1992年 | 200篇 |
1991年 | 176篇 |
1990年 | 149篇 |
1989年 | 140篇 |
1988年 | 159篇 |
1987年 | 117篇 |
1986年 | 131篇 |
1985年 | 121篇 |
1984年 | 103篇 |
1983年 | 67篇 |
1982年 | 57篇 |
1981年 | 66篇 |
1979年 | 97篇 |
1978年 | 56篇 |
1974年 | 57篇 |
1973年 | 73篇 |
1972年 | 58篇 |
1971年 | 62篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
目的 :观察不同部位静脉注射对无痛人工流产术的影响。方法 :随机将 2 0 0例要求行无痛人工流产术的患者分成二组 ,一组静脉注射部位为手背静脉组 ,另一组静脉注射部位为肘部浅静脉 (贵要静脉或肘正中静脉 )组 ,观察静脉推注异丙酚时患者的注射部位有无疼痛症状。结果 :肘部浅静脉注射部位疼痛感明显轻于手背静脉 ,肘部浅静脉注射部位的麻醉起效时间快于手背静脉 ,两组差异有显著性 (P <0 0 5 )。结论 :选择肘部浅静脉注射异丙酚可减轻患者注射部位的疼痛 ,可在短时间内取得理想的麻醉效果。 相似文献
52.
53.
不同剂量环孢素A对肾移植病人精液质量的影响 总被引:3,自引:3,他引:0
目的 :探讨不同治疗剂量环孢素A(CsA)对肾移植病人精液主要参数和精子形态学的影响。 方法 :对 18例应用不同治疗剂量CsA的肾移植病人的精液进行主要参数和精子形态学分析 ,并与 12例正常男性精液进行比较。 结果 :CsA剂量在 1.5~ 3.0mg·Kg-1·d-1及 3.1~ 5 .5mg·Kg-1·d-1时 ,病人精液的主要参数与正常男性精液比较差异无显著性 (P >0 .0 5 ) ,但病人正常形态精子百分率与正常男性相比差异有显著性 (P <0 .0 5 )。结论 :不同治疗剂量的CsA对肾移植病人的精液主要参数无明显影响 ,但对精子形态可能有一定的影响。 相似文献
54.
Abstract – Dental injuries are common following facial trauma. This article presents a rare injury: the dislocation of a third molar into the maxillary sinus after complex mandibular and maxillary tuberosity fractures. The possible mechanism and clinical treatment are discussed. 相似文献
55.
56.
Immature Megakaryocytes in the Mouse: Morphology and quantitation by acetylcholinesterase staining 总被引:10,自引:1,他引:9
Three types of immature megakaryocytes, detected by their morphological properties, have been characterized in bone marrow of normal C57BL/6 mice. Morphological classification of these cells was carried out by determining (1) presence and relative amount of acetylcholinesterase, (2) cell size, (3) nuclear/cytoplasm ratio, and (4) nuclear shape. The immature megakaryocytes were classified as: (A) cells distinguished by a round nucleus (10.6 +/- 1.1 mu diameter; mean +/- SEM), which had the highest nucleus / cytoplasm ratio and lowest content of acetylcholinesterase; (B) cells with an indented nucleus (13.0 +/- 1.9 mu diameter), which had increased acetylcholinesterase content and reduced nucleus/cytoplasm ratio compared to the round-nucleus cell type; and (C) lobed-nucleus cells (14.5 +/- 2.9 mu diameter), which showed further increase in acetylcholinesterase content and reduction in nucleus/cytoplasm ratio. Increased numbers of immature megakaryocytes were detected, indicating that a proportion of these cells are undetected using conventional staining techniques. Based on the observed alterations in size, acetylcholinesterase content, and nuclear complexity, it was concluded that these cells constitute part of a progressive maturation sequence intermediate between the progenitor cell (CFU-Mk) and mature easily recognizable megakaryocytes. 相似文献
57.
Two elderly patients, involved in separate motor vehicle accidents, sustained blunt chest injury resulting in rupture of their thoracic aortas. The initial chest radiographs showed the presence of a calcified ring fractured in two places with lateral displacement of a calcified fragment by haematoma. This ‘broken halo sign’ is a radiographic sign not previously well described in the literature. The presence of a disrupted aortic ring in the elderly patient, associated with the appropriate mechanism of injury, should alert the clinician to the potential diagnosis of traumatic rupture of the thoracic aorta (TRTA). 相似文献
58.
Long H. Phan Michael J. Hickey Zahid B. M. Niazi Alastair G. Stewart 《Microsurgery》1994,15(10):703-707
Nitric oxide (NO), originally identified as the mediator of endothelial-dependent relaxation of vascular smooth muscle, is now known to also have cytotoxic effects under certain conditions. Thus, we have investigated the effects of inhibition of NO synthesis on ischemia/reperfusion injury in the rabbit rectus femoris muscle. Three and a half hours of ischemia and 24 hours of reperfusion resulted in a 56% loss of viability. In muscles receiving an infusion of the nitric oxide synthase inhibitor, L-NIO (30 μM), the loss of viability was reduced to 15%. Post-ischemic blood flow was increased in muscles receiving a saline infusion, whereas there was a marked decrease in blood flow for at least the first 60 minutes of reperfusion in muscles treated with L-NIO (30 μM). The increase in myeloperoxidase levels (indicative of neutrophil accumulation) following 24 hours of reperfusion was attenuated with L-NIO infusion by approximately 50% and the reperfusion-induced edema was also attenuated in L-NIO treated muscle. These findings suggest that endogenous NO production during ischemia/reperfusion injury may be deleterious to muscle survival. © 1994 Wiley-Liss, Inc. 相似文献
59.
用PCR—RFLP和16SrDNA指纹图法分析幽门螺杆菌基因型 总被引:1,自引:1,他引:0
本文建立了PCR-RFLP和16srDNA指纹图法.对19株幽门螺杆菌(HP)进行基因型分析:HP尿素酶C基因的PCR扩增产物.分别用HindⅢ、HaeⅢ、AluⅠ酶切,结果显示:每个酶均将19株HP分为3种RFLP图谱.综合HindⅢ,HaeⅢ和AluⅠ酶切结果,19株HP分为10个酶切带型;PCR扩增HP标准株16SrRNA基因,地高辛标记制备550bp探针,19株HPDNA分别经HaeⅢ和EcoRⅠ酶切、电泳后,通过Southern杂交获16SrDNA指纹图,结果显示:HaeⅢ酶切分为14个杂交带型,EcoRⅠ酶切19株HP杂交带型均不同。本实验表明:上述两种方法重复性好,分群力高,可准确有效地对HP作出鉴定并将其分型。19株HP株间存在基因型差异。 相似文献
60.
用二甲苯所致的急性炎症模型观察了神效止痛膏的抗急性炎症作用.用扭体法、热板法观察了神效止痛膏对小鼠的镇痛作用.结果表明,神效止痛膏有很好的镇痛作用. 相似文献