全文获取类型
收费全文 | 881篇 |
免费 | 44篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 54篇 |
妇产科学 | 10篇 |
基础医学 | 65篇 |
口腔科学 | 36篇 |
临床医学 | 136篇 |
内科学 | 224篇 |
皮肤病学 | 23篇 |
神经病学 | 9篇 |
特种医学 | 246篇 |
外科学 | 43篇 |
综合类 | 30篇 |
预防医学 | 26篇 |
眼科学 | 15篇 |
药学 | 36篇 |
肿瘤学 | 36篇 |
出版年
2021年 | 6篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 14篇 |
2014年 | 12篇 |
2013年 | 21篇 |
2012年 | 9篇 |
2011年 | 6篇 |
2010年 | 27篇 |
2009年 | 39篇 |
2008年 | 12篇 |
2007年 | 54篇 |
2006年 | 21篇 |
2005年 | 16篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 13篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 15篇 |
1998年 | 60篇 |
1997年 | 70篇 |
1996年 | 71篇 |
1995年 | 59篇 |
1994年 | 44篇 |
1993年 | 49篇 |
1992年 | 12篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 43篇 |
1988年 | 23篇 |
1987年 | 37篇 |
1986年 | 13篇 |
1985年 | 25篇 |
1984年 | 20篇 |
1983年 | 25篇 |
1982年 | 19篇 |
1981年 | 17篇 |
1980年 | 20篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1977年 | 9篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1966年 | 2篇 |
1948年 | 1篇 |
1947年 | 1篇 |
排序方式: 共有991条查询结果,搜索用时 8 毫秒
51.
Templeton AW; Johnson JA; Anderson WH; Cook LT; Dwyer SJ d; Preston DF; Lee KR; Rosenthal SJ; Batnitzky S; Levine E 《Radiology》1984,151(2):527-528
The increasing use of digitally formatted imaging systems requires high-quality interactive gray-scale computer raster graphics systems for the management, display, and analog film recording of digital image and alphanumeric information. These systems are a combination of computer hardware and software and implement a set of graphics protocols. This paper describes a set of interactive graphics protocols that has been developed for clinical use. 相似文献
52.
In a patient with primary hyperparathyroidism an attempt was made to ablate a middle mediastinal parathyroid gland by forceful staining with radiographic contrast material. The gland was stained on two separate occasions, two weeks apart. Both times the serum calcium level temporarily fell to the normal range but reverted to abnormal levels. The patient ultimately required surgery for correction of hypercalcemia. The mechanism of staining and possible reasons for failure as well as potential complications are discussed. 相似文献
53.
54.
Gallium-67 lung uptake: conjugate-view technique 总被引:1,自引:0,他引:1
A conjugate-view technique is derived for calculation of absolute gallium-67 (Ga-67) uptake from scintillation-camera images. The technique combines counts of posterior and anterior images of the lung with an attenuation correction obtained from cobalt-57 (Co-57) transmission imaging. The formulation is such that the effects of Compton scatter build-up are accounted for. Studies utilizing a canine model indicated that, normally, more activity is located in the chest wall than in the lungs. The quantitative technique must therefore accurately account for a variety of Ga-67 distributions, including that in the chest wall. Calculations were performed using a three-component model comparing results obtained with the conjugate-view approach to the actual uptake. These calculations suggest that an assumption of uniform activity distribution allows an accuracy of approximately +/- 10% over a broad range of body-part thicknesses and uptake by the lungs. It was concluded that the conjugate-view technique is necessarily approximate but can provide clinically useful results. 相似文献
55.
Background
Haemorrhage after Cardio Pulmonary Bypass (CPB) Surgery is a well recognised complication that leads to significant morbidity and mortality. The incidence varies between 5-25% depending upon the clinical situation. Several factors are implicated as causative but none have been precisely proved.Methods
Our study was an attempt to evaluate the haemostatic defect with particular reference to platelet function abnormalities during cardio pulmonary bypass surgery, in order to reduce the morbidity and mortality associated with post CPB haemorrhage. Flow cytometric evaluation of different platelet glycoproteins like GPIb/IX, GPIIb/IIIa and GMP-140 was done.Results
The marker expression showed deregulation during surgery which returned to base after bypass was terminated. In contrast, the cases with bleeding showed significant variation. P-Selectin (GMP 140) expression decreased progressively till 3rd post-operative day showing lack of activation of platelets in cases of severe bleeding.Conclusion
Longer duration of CPB initiates plasmin generation through heparin, which raises the PAI-1-tPA complex and thereby down regulating the functions of platelets. This suggests a link between duration of CPB, bleeding, platelet dysfunction and fibrinolysis. Hence serial estimations of the levels of GMP-140 and tPA can predict severe bleeding.Key Words: CardioPulmonary Bypass, Platelet dysfunction, flowcytometry, platelet glycoproteins, haemorrhage 相似文献56.
57.
58.
Pneumocystis carinii pneumonia studied by gallium-67 scanning 总被引:1,自引:0,他引:1
The validity and reliability of gallium-67 (Ga-67) scanning for diagnosis and follow-up of Pneumocystis carinii pneumonia (PCP) were assessed in 34 patients thought to have pulmonary complications of acquired immunodeficiency syndrome (AIDS). Overall sensitivity was 94% and specificity 74%. Among patients with normal or equivocal chest radiographs at the time of admission, sensitivity was 86% and specificity 85%. The authors consider Ga-67 scanning a valid and reliable adjunct in the diagnosis of PCP in AIDS patients with respiratory symptoms when the chest radiograph is normal or equivocal. 相似文献
59.
目的:观察差速贴壁技术对星形胶质细胞纯化率的影响,旨在建立一套可靠的大鼠脑皮质星形胶质细胞的取材分离、纯化培养技术。方法:实验于2006-06/08在泰山医学院生命科学研究所完成。实验材料:出生2~3d的Wistar大鼠,雌雄不拘,由泰山医学院生命科学研究所实验动物中心提供。实验方法:选用出生二三天的Wistar大鼠进行脑皮质星形胶质细胞原代培养。实验分两组培养:常规培养组和差速贴壁培养组。差速贴壁培养组分别于15,30min取出,轻轻翻转培养瓶,将上清液移至另一培养瓶中,放入培养箱中继续培养。7~10d后传代,待细胞分层生长后,置于37℃摇床中250r/min振荡18h,倒掉上清液,D-Hank’s液洗3次后,加入0.25%胰酶消化,倒置显微镜下观察,待细胞突起回缩后加入含血清的培养基终止消化,用吸管反复吹打使细胞从瓶壁上脱落,细胞悬液1000r/min离心5min后,弃上清液,加入含体积分数为0.2血清的DMEM培养基混悬沉淀,接种入预先涂有L-多聚赖氨酸的培养瓶中继续培养。采用双重免疫荧光法鉴定星形胶质细胞纯度,测定积分吸光度值判断星形胶质细胞的生长状况。结果:①应用差速贴壁技术培养星形胶质细胞可明显提高星形胶质细胞纯度[常规培养组:(82±3)%,差速贴壁培养组15min:(94±2)%,差速贴壁培养组30min:(95±2)%,P<0.01]。差速贴壁需要充分的时间,15min组和30min组在提高星形胶质细胞纯度方面无明显差别。②差速贴壁培养组星形胶质细胞积分吸光度值高于常规培养组(常规培养组:528±25,差速贴壁培养组15min:972±17,差速贴壁培养组30min:996±35,P<0.05)。结论:①差速贴壁技术可明显提高星形胶质细胞纯化度,并且星形胶质细胞生长状态明显优于常规培养方法。②最佳差速贴壁时间为15min,过长差速贴壁时间对提高星形胶质细胞纯度无明显影响。 相似文献
60.
葛根素对高血压患者血浆内皮素和一氧化氮的影响 总被引:29,自引:0,他引:29
目的:检测正常人与高血压病(EH)患者血浆内皮素、一气体氮的变化及葛根素对其的干预效应。方法:EH对照组口服苯磺酸氨氯地平5mg/d,或合和盐酸苯那普利10mg/d,每日一次,15d为一疗程。EH伍用治疗组同时合用5%GNS250ml+葛根素注射液400mg静滴,两组治疗前后检测血浆ET、NO水平变化。结果:EH各组血浆ET较正常人组均显著增高(P〈0.01),血浆NO水平及NO/ET比值除轻度E 相似文献