全文获取类型
收费全文 | 16610篇 |
免费 | 1391篇 |
国内免费 | 636篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 93篇 |
妇产科学 | 43篇 |
基础医学 | 961篇 |
口腔科学 | 126篇 |
临床医学 | 1775篇 |
内科学 | 6375篇 |
皮肤病学 | 115篇 |
神经病学 | 446篇 |
特种医学 | 914篇 |
外国民族医学 | 1篇 |
外科学 | 2110篇 |
综合类 | 2299篇 |
现状与发展 | 1篇 |
预防医学 | 383篇 |
眼科学 | 102篇 |
药学 | 1980篇 |
12篇 | |
中国医学 | 534篇 |
肿瘤学 | 302篇 |
出版年
2024年 | 30篇 |
2023年 | 316篇 |
2022年 | 378篇 |
2021年 | 962篇 |
2020年 | 754篇 |
2019年 | 694篇 |
2018年 | 723篇 |
2017年 | 581篇 |
2016年 | 643篇 |
2015年 | 688篇 |
2014年 | 1094篇 |
2013年 | 1264篇 |
2012年 | 1017篇 |
2011年 | 1067篇 |
2010年 | 869篇 |
2009年 | 814篇 |
2008年 | 787篇 |
2007年 | 818篇 |
2006年 | 636篇 |
2005年 | 522篇 |
2004年 | 455篇 |
2003年 | 394篇 |
2002年 | 371篇 |
2001年 | 282篇 |
2000年 | 239篇 |
1999年 | 241篇 |
1998年 | 227篇 |
1997年 | 187篇 |
1996年 | 169篇 |
1995年 | 149篇 |
1994年 | 155篇 |
1993年 | 120篇 |
1992年 | 101篇 |
1991年 | 94篇 |
1990年 | 74篇 |
1989年 | 91篇 |
1988年 | 75篇 |
1987年 | 64篇 |
1986年 | 58篇 |
1985年 | 74篇 |
1984年 | 52篇 |
1983年 | 33篇 |
1982年 | 51篇 |
1981年 | 39篇 |
1980年 | 41篇 |
1979年 | 37篇 |
1978年 | 21篇 |
1977年 | 29篇 |
1976年 | 22篇 |
1974年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
急性心肌梗死急诊介入治疗的临床评价 总被引:4,自引:1,他引:3
目的探讨急诊经皮冠状动脉介入治疗术(PCI)对ST段抬高型急性心肌梗死(STAMI)的治疗价值。方法STAMI46例,在发病12h内行急诊冠状动脉造影及直接冠脉支架置入术(DS)或预扩张后支架置入术(PS),观察术中心律失常发生情况,术后TIMI分级、心电图,出院前左室射血分数(LVEF)和住院期间主要不良心脏事件(MACE)等。结果DS组与PS组各项指标无差异,44例达TIMI3级,成功率达95.7%,ST段回落率67.4%,平均LVEF(49.4±9.46)%,术中心律失常发生率21.7%,无MACE发生。结论对于发病12h的STAMI患者,行急诊PCI,可开通梗塞相关动脉(IRA),改善心肌再灌注和近期预后。 相似文献
14.
Anthony Z Faranesh Dara L Kraitchman Elliot R McVeigh 《Magnetic resonance in medicine》2006,55(5):1114-1123
The purpose of this work was to investigate the use of an intravascular contrast agent to determine perfusion kinetics in skeletal muscle. A two-compartment kinetic model was used to represent the flux of contrast agent between the intravascular space and extravascular extracellular space (EES). The relationship between the image signal-to-noise ratio (SNR) and errors in estimating permeability surface area product (Ktrans), interstitial volume (ve), and plasma volume (vp) for linear and nonlinear curve-fitting methods was estimated from Monte Carlo simulations. Similar results were obtained for both methods. For an image SNR of 60, the estimated errors in these parameters were 10%, 22%, and 17%, respectively. In vivo experiments were conducted in rabbits to examine physiological differences between these parameters in the soleus (SOL) and tibialis anterior (TA) muscles in the hind limb. Values for Ktrans were significantly higher in the SOL (3.2+/-0.9 vs. 2.0+/-0.5x10(-3) min-1), as were values for vp (3.4+/-0.8 vs. 2.1+/-0.7%). Differences in ve for the two muscles (8.7+/-2.2 vs. 8.5+/-1.6%) were not found to be significant. These results demonstrate that relevant physiological metrics can be calculated in skeletal muscle using MRI with an intravascular contrast agent. 相似文献
15.
经皮冠状动脉腔内成形术(PTCA)是近30年来治疗冠心病的主要技术之一,其相应的护理技术在过去近10年里有着明显的改进。本文以穿刺股动脉途径为重点综述国外PTCA术后留置动脉鞘管的护理进展:动脉外鞘管拔除责任者、拔除时间、拔管后局部压迫方法等内容,旨在提升PTCA术后的护理质量。 相似文献
16.
Role of intracortical mechanisms in the late part of the silent period to transcranial stimulation of the human motor cortex 总被引:3,自引:0,他引:3
J.P. Brasil-Neto A. Cammarota J. Valls-Solé A. Pascual-Leone M. Hallett L. G. Cohen 《Acta neurologica Scandinavica》1995,92(5):383-386
Transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES) of the human motor cortex produce a silent period (SP) following motor evoked potentials (MEPs). The early part of the SP can be explained by decreased alpha motor neuron excitability, whereas the late part is presumably due to suprasegmental mechanisms. In order to determine the level of the suprasegmental contribution to the generation of SPs, we recorded excitatory and inhibitory responses to TMS, TES, and percutaneous electrical brainstem stimulation (PBS) in the voluntarily activated first dorsal interosseous muscle of the hand. Stimulus intensities were set so that PBS and TES induced MEPs with areas equal to or larger than those of MEPs obtained with TMS. This procedure revealed that SPs were 49% and 83% shorter with TES and PBS, respectively, than with TMS. As TMS is more effective than TES or PBS in activating cortical interneurons, these findings support the idea that a significant component of the SP arises from intracortical mechanisms. 相似文献
17.
豚鼠耳蜗微血管内皮细胞体外通透性的研究 总被引:1,自引:0,他引:1
目的 研究豚鼠耳蜗微血管内皮细胞的体外通透性特征。方法 在成功建立豚鼠耳蜗微血管内皮细胞体外通透性模型的基础上 ,研究该体外模型跨细胞电阻及对12 5I 牛血清白蛋白的通透性。结果 ①耳蜗微血管内皮细胞在培养增殖过程中其跨细胞电阻呈动态变化过程 ,以 5× 10 4/cm2 的细胞密度接种时 ,7d左右电阻到达峰值 ,其跨细胞电阻峰值大小为 (118 9± 18 5 )Ω/cm2 ;②体外模型中加入12 5I 牛血清白蛋白后 ,其通透性呈上升期抛物线型曲线 ,90min内几乎呈直线。结论 跨细胞电阻及对12 5I 牛血清白蛋白变化曲线能反映体外耳蜗微血管内皮细胞的通透性特征 相似文献
18.
《中国药理学与毒理学杂志》1997,(1)
本实验探讨了内源性速激肽是否参与白三烯C4(LTC4)的气道效应.LTC4(0.5μgkg-1,iv)可增高豚鼠肺内压(IPP)和气道内依文思蓝渗出。速激肽NK-1受体拮抗剂CP-96345{(2S,3S)-顺式-2-(二苯甲基)-N-[(2-甲氧苯)-甲基]-1-杂氮双环[2.2.2]辛烷-3-胺}1mgkg-1,iv,可减弱LTC4诱导的依文思蓝渗出;NK-2受体拮抗剂SR-48968{(S)-N-甲基-N-[4-(4-乙酰氨基-4-苯基哌啶)-2-(3,4-二氯苯基)丁基]苯甲酰胺},1mgkg-1,iv,可抑制IPP的增高.白三烯拮抗剂ONO-1078(0.03mgkg-1,iv)可阻断这两种反应.结果说明内源性速激肽增强LTC4的气道作用,其中NK-1受体介导微血管渗漏,NK-2受体介导支气管收缩. 相似文献
19.
Guido Orlandini 《The journal of headache and pain》2002,3(1):37-47
The aim of this study was to define criteria for the selection of patients for percutaneous or open operations for the cure
of drug-resistant trigeminal neuralgia (TN). Trigeminal percutaneous radiofrequency thermorhizotomy (TPRT) has an established
place because of its safety in elderly patients, while microvascular decompression (MVD) has appeal in younger patients beause
of its non-destructive nature and because it attacks what is believed to be the primary etiology of tic douloureux.
Nevertheless, MVD is a successful operation only when true neurovascular conflict (NVC) is ascertained, rather than a simple
arterial loop and neurovascular contract. Probably, many immediate failures and early relapses are the consequence of the
inadequate patient selection for MVD on the presumption that this operation is in any case the ideal cure. The inadequate
selection can be explained by the difficult preoperative diagnosis of NVC in the past. Indeed, angiography and computed tomography
showed the neurovascular contact but not the size of compression. Fortunately, today magnetic resonance imaging is a reliable
instrument to ascertain NVC. So, the diatribe between the supporters of percutaneous techniques and MVD can be concluded with
the following: (1) percutaenous techniques are indicated for patients without demonstrated NVC (including patients with TN
in multiple sclerosis) and in those with NVC if MVD is contraindicated by ill-health or refused by the informed patient; and
(2) MVD is incated for patients with ascertained NVC who are in good health and who, informed of the surgical risk, favor
this operation desiring no sensory deficit.
Received: 23 June 2001 / Accepted in revised form: 24 August 2001 相似文献
20.
利用过氧化氢的氧化作用参与抗原抗体反应,使细胞的膜通透性增强,利于荧光标记抗体染液渗入,从而更快速、广泛地接触抗原,更有效的抗原抗体的嵌合交联。新技术的应用,增强了染色效果,缩短了实验时间,简化了操作,提高了阳性检出率,使实验准确性提高,为临床确诊、疗效观察及预后提供了可靠依据。 相似文献