全文获取类型
收费全文 | 581398篇 |
免费 | 302703篇 |
国内免费 | 59042篇 |
专业分类
耳鼻咽喉 | 5266篇 |
儿科学 | 7369篇 |
妇产科学 | 6068篇 |
基础医学 | 128202篇 |
口腔科学 | 8396篇 |
临床医学 | 106286篇 |
内科学 | 140020篇 |
皮肤病学 | 7758篇 |
神经病学 | 38028篇 |
特种医学 | 20563篇 |
外国民族医学 | 234篇 |
外科学 | 73397篇 |
综合类 | 112120篇 |
现状与发展 | 90篇 |
一般理论 | 32篇 |
预防医学 | 62617篇 |
眼科学 | 25641篇 |
药学 | 92626篇 |
415篇 | |
中国医学 | 65166篇 |
肿瘤学 | 42849篇 |
出版年
2023年 | 7599篇 |
2022年 | 17520篇 |
2021年 | 21213篇 |
2020年 | 19360篇 |
2019年 | 23628篇 |
2018年 | 24801篇 |
2017年 | 24448篇 |
2016年 | 22393篇 |
2015年 | 27716篇 |
2014年 | 30841篇 |
2013年 | 28780篇 |
2012年 | 37235篇 |
2011年 | 41770篇 |
2010年 | 33856篇 |
2009年 | 38054篇 |
2008年 | 29558篇 |
2007年 | 26591篇 |
2006年 | 26014篇 |
2005年 | 25817篇 |
2004年 | 20882篇 |
2003年 | 19285篇 |
2002年 | 18024篇 |
2001年 | 18701篇 |
2000年 | 14794篇 |
1999年 | 20344篇 |
1998年 | 18952篇 |
1997年 | 18758篇 |
1996年 | 18530篇 |
1995年 | 18599篇 |
1994年 | 17730篇 |
1993年 | 15424篇 |
1992年 | 15103篇 |
1991年 | 13957篇 |
1990年 | 12772篇 |
1989年 | 12286篇 |
1988年 | 11639篇 |
1987年 | 10890篇 |
1986年 | 10173篇 |
1985年 | 9110篇 |
1984年 | 6900篇 |
1983年 | 6784篇 |
1982年 | 7722篇 |
1981年 | 7225篇 |
1980年 | 6863篇 |
1979年 | 6718篇 |
1978年 | 5817篇 |
1977年 | 6124篇 |
1976年 | 5743篇 |
1975年 | 5482篇 |
1974年 | 5035篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
As a consequence of the time-varying magnetic field induced by eddy currents, frequency drifting occurs when the sampling window of localized spectroscopy continuously shifts. The frequency drifting and the concomitant phase variations can severely affect spectroscopy results when data are acquired with multiple echo times (TEs), such as in the measurement of glutamate (Glu) concentration using the TE-averaged method. Specifically, the averaged spectra are further broadened and distorted in the presence of residual eddy currents, and editing of the coupled spins of Glu C4 protons is affected, resulting in errors in the measured relative intensity ratio. Postacquisition correction using unsuppressed water as reference can effectively minimize this detrimental effect, as manifested by the significantly enhanced signal intensity. Also, it is demonstrated that the methyl signals of creatine (Cr) at 3.0 ppm and choline (Cho) at 3.2 ppm can be used as internal references in finding frequency and phase disparities between different TEs. 相似文献
43.
Pulmonary Lophomonas blattarum infection in patients with kidney allograft transplantation 总被引:3,自引:0,他引:3
Yong Wang Zheng Tang Shuming Ji Zhen Zhang Jinsong Chen Zhen Cheng Dongrui Cheng Zhihong Liu Leishi Li 《Transplant international》2006,19(12):1006-1013
The aim of the study was to analyse the clinical manifestation and management of pulmonary Lophomonas blattarum infection in four allograft transplantation recipients retrospectively. Four patients with pulmonary L. blattarum infection were diagnosed by using Fiberoptic bronchoscopy (FOB) and bronchoalveolar lavage (BAL) examination. Their clinical manifestation and management are summarized. Four cases of pulmonary L. blattarum were found during the period from the second month to the third month after transplantation. Concurring infection by other pathogens was found in three of them. Common initial symptoms included fever (>38 degrees C) without cough and breathlessness. Lower lobe shadowing could be found on chest X-ray. Body temperature decreased to the normal range in three patients and to 37.5 degrees C in the other one, after intravenous injection of metronidazole and tapering immunosuppressant. Radiological examination confirmed improved health condition of the patients afterwards. Two patients received repeated FOB and only dead L. blattarum was found. Pulmonary L. blattarum infection in allograft transplant recipients carry relatively obscure initial symptoms. Possible L. blattarum infection needs to be screened in post-transplantation pulmonary infection patients with similar symptoms, especially in those who respond poorly to anti-infection treatment. Microscopic examination of BAL fluid can help to identify pulmonary L. blattarum infection and metronidazole is an ideal treatment choice. 相似文献
44.
阿格雷(Peter Agre)博士,美国杜克大学医学院细胞生物学系教授,约翰斯霍普金斯大学医学院生物化学系客座教授。阿格雷教授其研究成果在于分离出了长期以来所搜寻的特定输送水分子的通道。这一发现开启了针对细菌、植物和哺乳动物水通道的系列生化、生理和遗传研究之门,从而使得研究人员可以仔细跟踪水分子通过细胞膜的过程,并了解为何只有水分子而不是其他小分子能够通过细胞膜,阿格雷博士也因此获得了2003年诺贝尔化学奖。 相似文献
45.
目的:综合分析近年来国内外神经修复用导管材料以及制备方法的研究近况。资料来源:应用计算机检索ElsevierScience1996-01/2005-12有关神经修复及神经导管方面的文献,检索词分别为“nerveconduit,nerveguide,nerveregeneration”,限定文献语言种类为English。同时计算机检索清华数字期刊库、万方数据库1996-01/2005-12有关神经修复及神经导管方面的文献,检索词为“神经修复,导管”,限定语言种类为中文。资料选择:对检索到的神经再生、神经修复及神经导管方面的相关信息进行整理,选取针对性强的文章。同一领域的文献则选择近期发表或权威杂志的文章。资料提炼:共收集120篇关于神经修复、神经导管的文献,纳入23篇符合标准的文献。资料综合:用神经导管桥接断离神经是神经修复的重要方法之一,制备神经导管的材料按其降解性能分为生物不可降解材料和生物可降解材料,任何一种材料都有其优缺点,发展复合材料将是制备导管的主要方向。结论:虽然影响神经再生的因素还有许多,如神经生长因子、雪旺细胞等,但是新型的导管及制备方法将会有利于神经修复进一步发展。 相似文献
46.
Jean-Sébastien Fallu Jürgen Rehm Emmanuel N. Kuntsche Esther Grichting Neerav Monga Edward M. Adlaf Susan J Bondy Gerhard Gmel 《Sozial- und Pr?ventivmedizin》2006,8(1):363-372
Volume and profile of alcohol consumption among students and classmates as predictors of aggression and victimization: a multilevel
analysis among Swiss adolescents
Objective:
To test the effects of the volume of alcohol consumption and drinking patterns on alcohol-related aggression and victimization, both at the individual and class levels. 相似文献47.
48.
Tetsuro Sano Munetaka Masuda Shigeki Morita Hisataka Yasui 《The Japanese Journal of Thoracic and Cardiovascular Surgery》2006,54(4):149-154
OBJECTIVE: It is well documented that cardiopulmonary bypass (CPB) severely impairs cellular immunity. The objective of this study was to investigate the effect of prostaglandin E1 (PGE1) on cellular immunity after CPB. METHODS: Patients who underwent elective cardiac surgery were randomly divided into the PGE1 group (n=12) and the control group (n=12). In the PGE1 group, PGE1 was administered at 20 ng/kg/min from just after the induction of anesthesia to the end of surgery. Peripheral blood mononuclear cells (PBMCs) were taken before anesthesia and on postoperative days 1, 3 and 7 (POD 1, POD 3 and POD 7). Proliferation responses of T cells to phytohemagglutinin (PHA) and pure protein derivative (PPD) antigen were measured as indicators of cellular immunity. RESULTS: PGE1 significantly attenuated the impairment of both PHA and PPD response after cardiac surgery on POD 1 (PHA response, 30 +/- 21% vs. 53 +/- 32%, control vs. PGE, p=0.048; PPD response, 18 +/- 21% vs. 39 +/- 27%, control vs. PGE, p=0.046). The reduced glutathione content of PBMCs in the control group was significantly decreased on POD 1. CONCLUSION: PGE1 attenuated the impairment of cellular immunity after cardiac surgery with CPB by reducing oxidative stress on PBMCs. 相似文献
49.
目的观察前置胎盘孕妇的恐惧心理反应,做好前置胎盘孕妇的心理护理。方法由孕妇自行填写CES-D和SA2量表,进行统计学分析。结果70.2%的前置胎盘孕妇具有恐惧心理。结论在妊娠过程应提高孕妇认知水平,加强心理护理,有助于她们顺利渡过妊娠期。 相似文献
50.