全文获取类型
收费全文 | 6857篇 |
免费 | 369篇 |
国内免费 | 110篇 |
专业分类
耳鼻咽喉 | 31篇 |
儿科学 | 153篇 |
妇产科学 | 124篇 |
基础医学 | 426篇 |
口腔科学 | 67篇 |
临床医学 | 1061篇 |
内科学 | 1162篇 |
皮肤病学 | 63篇 |
神经病学 | 611篇 |
特种医学 | 509篇 |
外科学 | 1453篇 |
综合类 | 757篇 |
预防医学 | 262篇 |
眼科学 | 19篇 |
药学 | 347篇 |
4篇 | |
中国医学 | 105篇 |
肿瘤学 | 182篇 |
出版年
2024年 | 10篇 |
2023年 | 102篇 |
2022年 | 290篇 |
2021年 | 281篇 |
2020年 | 244篇 |
2019年 | 214篇 |
2018年 | 240篇 |
2017年 | 182篇 |
2016年 | 203篇 |
2015年 | 213篇 |
2014年 | 504篇 |
2013年 | 428篇 |
2012年 | 377篇 |
2011年 | 420篇 |
2010年 | 434篇 |
2009年 | 374篇 |
2008年 | 359篇 |
2007年 | 354篇 |
2006年 | 278篇 |
2005年 | 257篇 |
2004年 | 206篇 |
2003年 | 169篇 |
2002年 | 141篇 |
2001年 | 108篇 |
2000年 | 119篇 |
1999年 | 98篇 |
1998年 | 70篇 |
1997年 | 69篇 |
1996年 | 52篇 |
1995年 | 60篇 |
1994年 | 61篇 |
1993年 | 35篇 |
1992年 | 48篇 |
1991年 | 36篇 |
1990年 | 35篇 |
1989年 | 40篇 |
1988年 | 34篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 28篇 |
1984年 | 26篇 |
1983年 | 8篇 |
1982年 | 15篇 |
1981年 | 14篇 |
1980年 | 10篇 |
1979年 | 11篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 7篇 |
1972年 | 6篇 |
排序方式: 共有7336条查询结果,搜索用时 15 毫秒
11.
两种不同术式治疗下肢静脉功能不全的近期疗效对照研究 总被引:1,自引:1,他引:0
目的 评价腔内射频闭合术联合TriVex刨吸术治疗下肢静脉功能不全的疗效. 方法 150例下肢静脉功能不全患者(150条患肢)随机分为A、B两组,每组75例.A组行大隐静脉射频闭合术联合曲张浅静脉TriVex刨吸术,B组行大隐静脉高位结扎抽剥术联合曲张浅静脉TriVex刨吸术.比较两组手术情况、术后4周患者对手术的自身评价、手术前后CEAP(clinic,etiologic,anatomic and pathophysiological classification)分级和临床严重程度计分(venous clinical severity score,vcss)的变化.结果 A、B两组手术时间分别为(67±11)min和(69±9)min(P>0.05),A组术后疼痛轻、下地时间早、住院天数少、皮下血肿发生率低,但皮下硬结发生率高于B组;对手术的评价A组为(11.21±2.00)分优于B组(10.52±2.08)分,差异有统计学意义(P<0.05);两组手术前后CEAP分级和VCSS计分变化差异均有统计学意义(P<0.01),A、B两组手术前后VCSS分差为(4.6±2.5)分和(4.3±2.7)分(P>0.05).结论 利用射频闭合术联合TriVex刨吸术治疗下肢静脉功能不全有效,且微创、并发症少.CEAP临床分级和VCSS临床记分可用于其疗效评价. 相似文献
12.
<正>laboratory equipment,akey to success is not only high quality,complete,technician knowledge,skills,and experiment a clear purpose,select the project has specificity 相似文献
13.
Abstract: Adequate venous access is an essential component of therapeutic plasma exchange (TPEX). The simplest kind of venous access is venipuncture of antecubital veins, but this technique may be limited by venous size or scarring following the procedure, requiring the placement of a specialized vascular access device (VAD). VADs provide reliable central venous access and may remain in place for several weeks or months, depending on the VAD and the venous site chosen. Their use, however, is potentially limited by the risk of complications. We discuss indications for insertion, choice of catheter and access site, and complications of VAD placement for TPEX. 相似文献
14.
15.
目的:探讨甲状腺激素水平在急性动脉栓塞中中西医结合治疗过程中的变化规律及其临床意义。方法:利用放射免疫分析法对40例本病患者及30例健康对照组进行血清甲状腺激素测定,观察中西医结合治疗前后的变化,结果;40例病人均存在在低T3、低T4和高rT3血症,且以重症病人最明显,T3水平低于0.5nmol/L者病情危重,T4低于50nmol/L者预后不良;低T3、低T4和高rT3血症均随中西医结合有效治疗后 相似文献
16.
17.
18.
19.
L. Lange M. Echt K. Kirsch O. H. Gauer 《Pflügers Archiv : European journal of physiology》1972,337(4):311-322
Summary The phenomena of stress-relaxation and capillary outward filtration were studied in the isolated rabbit ear, perfused with blood at constant flow. The volume increase, as measured by the plethysmograph, following elevation of venous outflow pressure to 20 mm Hg for 4 min was predominantly due to capillary outward filtration in the norepinephrine constricted vascular bed (0.5 g/min). With papaverine induced dilatation (0.08 mg/min) this persistent volume increase could be attributed mainly to stress-relaxation of the veins. Engorgement of venous vessels as well as capillary outward filtration led to an increase of the ear volume that is measured by the plethysmographic technique. The photographic-photoelectric measurement of venous diameter changes was used in these experiments to distinguish intravascular from extravascular volume changes. The moduli of volume elasticity were calculated for smaller and larger veins (mean diameter 0.133 mm and 0.553 mm) with norepinephrine constriction. It has been demonstrated that the smaller veins were about seven times less distensible than the larger veins.This investigation was supported by Contract F44620-71-C-0117 of the USAF School of Aerospace Medicine, European Office of Aerospace Research (OAR), U.S. Air Force and Deutsche Forschungsgemeinschaft.This work was presented in part at the 39. Tagung der Deutschen Physiologischen Gesellschaft, Erlangen, April 1972 [Pflügers Arch. Suppl.332, R 54 (1972)]. 相似文献
20.
Nitric oxide (NO) is a physiological species involved in inhibition of platelet adhesion and aggregation. A novel NO delivery device was utilized to quantitatively assess the effects of gaseous NO on platelet deposition to agonist-coated biomaterials in the presence of a platelet suspension. Platelet deposition was evaluated as a function of agonist (collagen, fibrinogen, or IgG), shear rate (250, 500, and 750 s–1), and perfusion time (5, 7.5, and 15 min). The minimal aqueous surface NO concentrations and fluxes necessary for significant inhibition of platelet deposition were quantified. Platelet deposition was completely inhibited at a gaseous NO exposure of 0.1 ppm, irrespective of the platelet agonist, shear rate, and perfusion time. The corresponding aqueous surface NO concentration was 0.09 nM at 250 s–1 as predicted by a validated model. Surface fluxes ranged between 0.3 and 0.6 femtomoles cm–2 s–1. The results of this study are useful for establishing generalized guidelines (i.e., NO flux requirements in the presence of agonists, shear rate, and perfusion time) for the design and development of suitable biomaterials incorporating NO to reduce platelet deposition. Further studies incorporating blood, rather than platelet suspensions, are required to provide a more complete assessment of the required NO flux necessary to inhibit platelet deposition. © 2000 Biomedical Engineering Society.
PAC00: 8717-d, 8719Tt 相似文献