全文获取类型
收费全文 | 3840篇 |
免费 | 370篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 184篇 |
妇产科学 | 145篇 |
基础医学 | 447篇 |
口腔科学 | 36篇 |
临床医学 | 538篇 |
内科学 | 611篇 |
皮肤病学 | 203篇 |
神经病学 | 250篇 |
特种医学 | 202篇 |
外科学 | 673篇 |
综合类 | 85篇 |
一般理论 | 1篇 |
预防医学 | 381篇 |
眼科学 | 35篇 |
药学 | 274篇 |
中国医学 | 11篇 |
肿瘤学 | 141篇 |
出版年
2023年 | 18篇 |
2022年 | 18篇 |
2021年 | 58篇 |
2020年 | 32篇 |
2019年 | 57篇 |
2018年 | 68篇 |
2017年 | 73篇 |
2016年 | 59篇 |
2015年 | 68篇 |
2014年 | 105篇 |
2013年 | 138篇 |
2012年 | 183篇 |
2011年 | 205篇 |
2010年 | 121篇 |
2009年 | 108篇 |
2008年 | 166篇 |
2007年 | 211篇 |
2006年 | 169篇 |
2005年 | 199篇 |
2004年 | 164篇 |
2003年 | 143篇 |
2002年 | 139篇 |
2001年 | 118篇 |
2000年 | 105篇 |
1999年 | 127篇 |
1998年 | 90篇 |
1997年 | 82篇 |
1996年 | 61篇 |
1995年 | 57篇 |
1994年 | 57篇 |
1993年 | 46篇 |
1992年 | 90篇 |
1991年 | 87篇 |
1990年 | 71篇 |
1989年 | 70篇 |
1988年 | 61篇 |
1987年 | 66篇 |
1986年 | 53篇 |
1985年 | 59篇 |
1984年 | 45篇 |
1983年 | 39篇 |
1982年 | 34篇 |
1981年 | 24篇 |
1980年 | 21篇 |
1979年 | 21篇 |
1978年 | 21篇 |
1976年 | 29篇 |
1975年 | 17篇 |
1974年 | 26篇 |
1973年 | 19篇 |
排序方式: 共有4235条查询结果,搜索用时 140 毫秒
131.
132.
133.
134.
Rüdiger Kaspera Brian J. Kirby Tariku Sahele Ann C. Collier Evan D. Kharasch Jashvant D. Unadkat Rheem A. Totah 《Biochemical pharmacology》2014
Ritonavir, an HIV protease inhibitor, is successfully used for the prevention and treatment of HIV infections. Ritonavir pharmacokinetics are complicated by inhibition, induction and pharmacogenetics of cytochrome P450 (CYP) enzymes mediating its clearance. This investigation revealed that CYP2J2, along with CYP3A4/5 and CYP2D6, efficiently metabolizes ritonavir, and to a CYP2J2-specific (minor) metabolite. Chemical inhibition of ritonavir metabolism, clearance, KI/kinact and abundance of CYP2J2 in liver microsomes were evaluated and then applied to an in vitro–in vivo static scaling model to estimate the contribution of each isozyme, as a function of CYP abundance, activity, and genotype. Disposition of the CYP2J2-specific metabolite was also evaluated in vivo. In plasma, metabolite abundance was well above previously reported levels with circulating concentrations measured at 2 μM for the main hydroxylisopropyl metabolite. Ritonavir and metabolite plasma profiles were simulated using Simcyp®. A modest (2–6%) contribution of CYP2J2 to ritonavir clearance is predicted which increases to more than 20% in subjects carrying CYP2D6 poor metabolizer polymorphisms and CYP3A4 irreversible inhibition. These results indicate that minor drug metabolizing enzymes could become quantitatively important in RTV clearance if main metabolic pathways are impeded. 相似文献
135.
136.
137.
Effects of a novel antiplatelet agent in mural thrombogenesis on collagen-coated glass 总被引:2,自引:1,他引:2
A parallel plate flow chamber and an epifluorescence video microscopy system were used to investigate the inhibitory effect of a novel antiplatelet agent (GT-12), a carbamoylpiperidine congener, on surface platelet aggregation and on the kinetics of thrombus growth induced by collagen-coated glass under controlled flow. Both macroscopic and microscopic measurements revealed that increasing concentrations of the drug correspondingly decreased the reaction rate between platelets at the surface, thereby reducing thrombus rate of growth at the surface. Because of decreased platelet/platelet adhesion, there was some embolization of the larger thrombi near the inlet of the reactive surface. In the presence of GT-12, average thrombus size and number of platelets per thrombus were both strikingly lowered. In addition, the net rate of growth of individual thrombi decreased to zero after short exposure times (about 60 seconds), in sharp contrast to controls. In contrast to chlorpromazine, GT-12 was effective in inhibiting platelet aggregation and thrombus rate of growth at relatively low concentrations (less than 100 mumol/L) in whole blood. The drug's effectiveness relative to controls in impeding platelet/platelet interactions was found to increase with decreasing incubation time and increasing perfusion time. 相似文献
138.
Gold MR Shorofsky SR Bouhouch R Joy RA Kirby DS Osman AF Rashba EJ 《Journal of cardiovascular electrophysiology》2002,13(4):332-335
INTRODUCTION: Atrial defibrillation can be achieved with standard implantable cardioverter defibrillator leads, which has led to the development of combined atrial and ventricular devices. For ventricular defibrillation, use of an active pectoral electrode (active can) in the shocking pathway markedly reduces defibrillation thresholds (DFTs). However, the effect of an active pectoral can on atrial defibrillation is unknown. METHODS AND RESULTS: This study was a prospective, randomized, paired comparison of two shock configurations on atrial DFTs in 33 patients. The lead system evaluated was a dual-coil transvenous defibrillation lead with a left pectoral pulse generator emulator. Shocks were delivered either between the right ventricular coil and proximal atrial coil (lead) or between the right ventricular coil and an active can in common with the atrial coil (active can). Delivered energy at DFT was 4.2 +/- 4.1 J in the lead configuration and 5.0 +/- 3.7 J in the active can configuration (P = NS). Peak current was 32% higher with an active can (P < 0.01), whereas shock impedance was 18% lower (P < 0.001). Moreover, a low threshold (< or = 3 J) was observed in 61% of subjects in the lead configuration but in only 36% in the active can configuration (P < 0.05). There were no clinical predictors of the atrial DFT. CONCLUSION: These results indicate that low atrial DFTs can be achieved using a transvenous ventricular defibrillation lead. Because no benefit was observed with the use of an active pectoral electrode for atrial defibrillation, programmable shock vectors may be useful for dual-chamber implantable cardioverter defibrillators. 相似文献
139.
Prostaglandin E1 infusions for vascular insufficiency in progressive systemic sclerosis. 总被引:1,自引:1,他引:1
下载免费PDF全文
![点击此处可从《Annals of the rheumatic diseases》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M F Martin P M Dowd E F Ring E D Cooke P A Dieppe J D Kirby 《Annals of the rheumatic diseases》1981,40(4):350-354
Twelve patients with systemic sclerosis (SS) and severe Raynaud's phenomenon received infusions of prostaglandin E1 (PGE1) at a dose of 6-10 ng/kg/min, with either saline or 5% dextrose, for 72 hours in a single-blind cross-over study. The infusions were administered intravenously by centrally positioned catheters. Infusions were well tolerated with only mild side effects. Following the PGE1 infusion cold tolerance improved and attacks of Raynaud's phenomenon were less frequent, less severe, and shorter in duration. This subjective improvement was maintained for several weeks in most patients, and 2 noted healing of ischaemic ulcers. There was no significant change in objective measurements of hand function after either infusion. However, pain measured on a 10 cm visual analogue scale improved 2.19 cm with PGE1 and only 0.91 cm with normal saline (P less than 0.05). Temperature of the fingers and hands recorded by thermography did not change significantly with saline infusions, but did rise during PGE1 infusions (mean rise 2.0 degrees C at 48 hours, p less than 0.001), and was maintained when measured again 2 weeks later (mean rise 1.56 degrees C, p less 0.001). PGE1 may therefore be suitable treatment for Raynaud's phenomenon and the vascular insufficiency of systemic sclerosis and other connective tissue diseases. 相似文献