全文获取类型
收费全文 | 1469篇 |
免费 | 88篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 10篇 |
妇产科学 | 9篇 |
基础医学 | 287篇 |
口腔科学 | 48篇 |
临床医学 | 201篇 |
内科学 | 281篇 |
皮肤病学 | 22篇 |
神经病学 | 66篇 |
特种医学 | 27篇 |
外科学 | 154篇 |
综合类 | 1篇 |
预防医学 | 86篇 |
眼科学 | 16篇 |
药学 | 231篇 |
中国医学 | 3篇 |
肿瘤学 | 107篇 |
出版年
2023年 | 14篇 |
2022年 | 10篇 |
2021年 | 37篇 |
2020年 | 18篇 |
2019年 | 43篇 |
2018年 | 55篇 |
2017年 | 33篇 |
2016年 | 44篇 |
2015年 | 57篇 |
2014年 | 67篇 |
2013年 | 137篇 |
2012年 | 176篇 |
2011年 | 189篇 |
2010年 | 148篇 |
2009年 | 42篇 |
2008年 | 25篇 |
2007年 | 16篇 |
2006年 | 13篇 |
2004年 | 8篇 |
2003年 | 11篇 |
2002年 | 9篇 |
2001年 | 8篇 |
2000年 | 14篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 22篇 |
1995年 | 9篇 |
1994年 | 10篇 |
1993年 | 11篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 12篇 |
1988年 | 12篇 |
1987年 | 10篇 |
1986年 | 11篇 |
1984年 | 19篇 |
1983年 | 9篇 |
1982年 | 13篇 |
1981年 | 16篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 11篇 |
1977年 | 16篇 |
1976年 | 18篇 |
1975年 | 6篇 |
1974年 | 7篇 |
1972年 | 10篇 |
1971年 | 7篇 |
1967年 | 12篇 |
1965年 | 9篇 |
排序方式: 共有1557条查询结果,搜索用时 46 毫秒
1.
2.
Éktova L. V. Goryunova O. V. Eremina V. A. Tikhonova N. I. Medvedeva L. A. 《Pharmaceutical Chemistry Journal》2019,53(7):604-609
Pharmaceutical Chemistry Journal - Use of formylindolylacetic acid as a reagent at the stage of preparing the glycosides of bis(indolyl)furan-2,5-diones and dioxane as solvent increased yields from... 相似文献
3.
4.
5.
6.
Chelyabinsk Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR A. D. Ado.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 3, pp. 299–301, March, 1992. 相似文献
7.
JUDITH VAN ASPEREN OLAF H. VAN TELLINGEN JOS H. BEIJNEN 《Pharmacological research》1998,37(6):429-435
P-glycoprotein, a membrane-associated transport protein, has recently been recognised as an important element of the intestinal epithelium. This paper summarises thein vivodata on the pharmacological role of intestinal P-glycoprotein. These data show that P-glycoprotein contributes to the elimination of many drugs by mediating their direct secretion from the blood into the intestinal lumen. In addition, there is also evidence that this protein can limit oral drug absorption. Hence, inhibition of intestinal P-glycoprotein, e.g. by a reversal agent like cyclosporin A, may be a promising strategy for improving the oral bioavailability of P-glycoprotein substrate drugs. Indeed, several preclinical and clinical studies have shown that coadministration of drugs with a reversal agent can substantially increase oral drug absorption. 相似文献
8.
E. A. Érenpreisa R. A. Zirne N. D. Zaleskaya T. G. Sjakste 《Bulletin of experimental biology and medicine》1988,106(5):1605-1608
Laboratory of Chemistry of the Cancer Cell, Latvian Research Institute of Experimental and Clinical Medicine, Ministry of Health of the Latvian SSR, Riga. (Presented by Academician of the Academy of Medical Sciences of the USSR I. B. Zbarskii.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 106, No. 11, pp. 591–593, November, 1988. 相似文献
9.
JORGE M. DAVIDENKO M.D. MARIO DELMAR M.D. Ph .D. JACQUES BEAUMONT Ph .D. DONALD C. MICHAELS Ph .D. PACO LORENTE Ph .D. JOSÉ JALIFE M.D. 《Journal of cardiovascular electrophysiology》1994,5(11):945-960
Inhibition and Facilitation in Cardiac Muscle. Introduction: The effects of subthreshold electrical pulses on the response to subsequent stimulation have been described previously in experimental animal studies as well as in the human heart. In addition, previous studies in cardiac Purkinje fibers have shown that diastolic excitability may decrease after activity (active inhibition) and, to a lesser extent, following subthreshold responses (electrotonic inhibition). However, such dynamic changes in excitability have not been explored in isolated ventricular muscle, and it is uncertain whether similar phenomena may play any role in the activation pal-terns associated with propagation abnormalities in the myocardium. Methods and Results: Experiments were performed in isolated sheep Purkinje fibers and papillary muscles, and in enzymatically dissociated guinea pig ventricular myocytes. In all types of preparations introduction of a conditioning subthreshold pulse between two subthreshold pulses was followed by a transient decay in excitability (electrotonic inhibition). The degree of inhibition was directly related to the amplitude and duration of the conditioning pulse and inversely related to the postconditioning interval. Yet, inhibition could be demonstrated long after (> 1 sec) the end of the conditioning pulse. Electrotonic inhibition was found at all diastolic intervals and did not depend on the presence of a previous action potential. In Purkinje fibers, conditioning action potentials led to active inhibition of subsequent responses. In contrast, in muscle cells, such action potentials had a facilitating effect (active facilitation). Electrotonic inhibition and active facilitation were observed in both sheep ventricular muscle and guinea pig ventricular myocytes. Accordingly, during repetitive stimulation with pulses of barely threshold intensity, we observed: (1) bistability (i.e., with the same stimulating parameters, stimulus: response patterns were either 1:1 or 1:0, depending on previous history), and (2) abrupt transitions between 1:1 and 1:0 (absence of intermediate wenckebach-like patterns). Simulations utilizing an ionic model of cardiac myocytes support the hypothesis that electrotonic inhibition in well-polarized ventricular muscle is the result of partial activation of Ik following subthreshold pulses. On the other hand, active facilitation may be the result of an activity-induced decrease in the conductance of IK1. Conclusion: Diastolic excitability of well-polarized ventricular myocardium may be transiently depressed following local responses and transiently enhanced following action potentials. On the other hand, diastolic excitability decreases during quiescence. Active facilitation and electrotonic inhibition may have an important role in determining the dynamics of excitation of the myocardium in the presence of propagation abnormalities. 相似文献
10.