全文获取类型
收费全文 | 4442篇 |
免费 | 275篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 93篇 |
妇产科学 | 99篇 |
基础医学 | 913篇 |
口腔科学 | 90篇 |
临床医学 | 320篇 |
内科学 | 721篇 |
皮肤病学 | 142篇 |
神经病学 | 397篇 |
特种医学 | 151篇 |
外科学 | 515篇 |
综合类 | 15篇 |
预防医学 | 366篇 |
眼科学 | 107篇 |
药学 | 575篇 |
中国医学 | 27篇 |
肿瘤学 | 155篇 |
出版年
2023年 | 45篇 |
2022年 | 38篇 |
2021年 | 85篇 |
2020年 | 85篇 |
2019年 | 122篇 |
2018年 | 242篇 |
2017年 | 151篇 |
2016年 | 187篇 |
2015年 | 166篇 |
2014年 | 266篇 |
2013年 | 378篇 |
2012年 | 495篇 |
2011年 | 563篇 |
2010年 | 302篇 |
2009年 | 119篇 |
2008年 | 121篇 |
2007年 | 83篇 |
2006年 | 79篇 |
2005年 | 39篇 |
2004年 | 28篇 |
2003年 | 37篇 |
2002年 | 21篇 |
2001年 | 47篇 |
2000年 | 37篇 |
1999年 | 41篇 |
1998年 | 44篇 |
1997年 | 40篇 |
1996年 | 36篇 |
1995年 | 39篇 |
1994年 | 31篇 |
1993年 | 19篇 |
1992年 | 28篇 |
1991年 | 26篇 |
1990年 | 31篇 |
1989年 | 23篇 |
1988年 | 26篇 |
1986年 | 22篇 |
1985年 | 26篇 |
1984年 | 30篇 |
1983年 | 19篇 |
1982年 | 31篇 |
1981年 | 21篇 |
1980年 | 20篇 |
1979年 | 21篇 |
1977年 | 23篇 |
1976年 | 20篇 |
1975年 | 25篇 |
1974年 | 18篇 |
1973年 | 23篇 |
1967年 | 19篇 |
排序方式: 共有4729条查询结果,搜索用时 15 毫秒
1.
2.
Bielik Peter Bonczek Ondřej Krejčí Přemysl Zeman Tomáš Izakovičová-Hollá Lydie Šoukalová Jana Vaněk Jiří Vojtěšek Bořivoj Lochman Jan Balcar Vladimir J. Šerý Omar 《Clinical oral investigations》2022,26(12):7045-7055
Clinical Oral Investigations - The aim of this study was the analysis of WNT10A variants in seven families of probands with various forms of tooth agenesis and self-reported family history of... 相似文献
3.
Journal of Assisted Reproduction and Genetics - 相似文献
4.
5.
6.
Sigita Gelman rius Sakalauskas Romanas Zykus rius Pranculis Rytis Jurkonis Irma Kuliavienė Arūnas Lukoševičius Limas Kupčinskas Juozas Kupčinskas 《World journal of gastroenterology : WJG》2020,26(38):5836-5848
BACKGROUND Degree of portal hypertension(PH) is the most important prognostic factor for the decompensation of liver cirrhosis and death, therefore adequate care for patients with liver cirrhosis requires timely detection and evaluation of the presence of clinically significant PH(CSPH) and severe PH(SPH). As the most accurate method for the assessment of PH is an invasive direct measurement of hepatic venous pressure gradient(HVPG), the search for non-invasive methods to diagnose these conditions is actively ongoing.AIM To evaluate the feasibility of parameters of endogenously induced displacements and strain of liver to assess degree of PH.METHODS Of 36 patients with liver cirrhosis and measured HVPG were included in the casecontrol study. Endogenous motion of the liver was characterized by derived parameters of region average tissue displacement signal(dantero, dretro, d RMS) and results of endogenous tissue strain imaging using specific radiofrequency signal processing algorithm. Average endogenous strain μ and standard deviation σ of strain were assessed in the regions of interest(ROI)(1 cm × 1 cm and 2 cm × 2 cm in size) and different frequency subbands of endogenous motion(0-10 Hz and 10-20 Hz).RESULTS Four parameters showed statistically significant(P 0.05) correlation with HVPG measurement. The strongest correlation was obtained for the standard deviation of strain(estimated at 0-10 Hz and 2 cm × 2 cm ROI size). Three parameters showed statistically significant differences between patient groups with CSPH, but only dretro showed significant results in SPH analysis. According to ROC analysis area under the curve(AUC) of the σROI[0…10 Hz, 2 cm × 2 cm] parameter reached 0.71(P = 0.036) for the diagnosis of CSPH; with a cut-off value of 1.28 μm/cm providing 73% sensitivity and 70% specificity. AUC for the diagnosis of CSPH for μROI[0…10 Hz, 1 cm × 1 cm] was 0.78(P = 0.0024); with a cut-off value of 3.92 μm/cm providing 73% sensitivity and 80% specificity. Dretro parameter had an AUC of 0.86(P = 0.0001) for the diagnosis of CSPH and 0.84(P = 0.0001) for the diagnosis of SPH. A cut-off value of-132.34 μm yielded 100% sensitivity for both conditions, whereas specificity was 80% and 72% for CSPH and SPH respectively.CONCLUSION The parameters of endogenously induced displacements and strain of the liver correlated with HVPG and might be used for non-invasive diagnosis of PH. 相似文献
7.
Background
Reports on childhood cancer survivors estimated cumulative probability of developing secondary neoplasms vary from 3,3% to 25% at 25 years from diagnosis, and the risk of developing another cancer to several times greater than in the general population. 相似文献8.
9.
Peter Kokol Marjan Mernik Jernej Završnik Kurt Kancler Ivan Malčić 《Journal of medical systems》1994,18(4):201-206
Computerized information systems, especially decision support systems, have become an increasingly important role in medical applications, particularly in those where important decision must be made effectively and reliably. But the possibility of using computers in medical decision making is limited by many difficulties, including the complexity of conventional computer languages, methodologies and tools. Thus a conceptual simple decision making model with the possibility of automating learning should be used. In this paper we introduce a cardiological knowledge-based system based on the decision tree approach supporting the mitral valve prolapse determination. Prolapse is defined as the displacement of a bodily part from its normal position. The term mitral valve prolaps (PMV), therefore, implies that the mitral leaflets are displaced relative to some structure, generally taken to be the mitral annulus. The implications of the PMV are the following: disturbed normal laminar blood flow, turbulence of the blood flow, injury of the chordae tendinae, the possibility of thrombus's composition, bacterial endocarditis, and finally hemodynamic changes defined as mitral insufficiency and mitral regurgitation. Uncertainty persists about how it should be diagnosed and about its clinical importance. It is our deep belief that the echocardiography enables properly trained experts armed with proper criteria to evaluate PMV almost 100%. But unfortunately, there are some problems concerned with the use of echocardiography. In that manner we have decided to start a research project aimed at finding new criteria and enabling the general practitioner to evaluate PMV using conventional methods and to select potential patients from the general population. To empower one to perform needed activities we have developed a computer tool called ROSE (computeRised prOlaps Syndrom dEtermination) based on algorithms of automatic learning. This tool supports the definition of new criteria and the selection of potential PMV-patients. 相似文献
10.