全文获取类型
收费全文 | 7037篇 |
免费 | 412篇 |
国内免费 | 60篇 |
专业分类
耳鼻咽喉 | 142篇 |
儿科学 | 213篇 |
妇产科学 | 70篇 |
基础医学 | 832篇 |
口腔科学 | 82篇 |
临床医学 | 738篇 |
内科学 | 1956篇 |
皮肤病学 | 99篇 |
神经病学 | 585篇 |
特种医学 | 233篇 |
外国民族医学 | 7篇 |
外科学 | 1152篇 |
综合类 | 71篇 |
预防医学 | 382篇 |
眼科学 | 63篇 |
药学 | 428篇 |
中国医学 | 7篇 |
肿瘤学 | 449篇 |
出版年
2023年 | 36篇 |
2022年 | 55篇 |
2021年 | 132篇 |
2020年 | 75篇 |
2019年 | 134篇 |
2018年 | 175篇 |
2017年 | 119篇 |
2016年 | 137篇 |
2015年 | 177篇 |
2014年 | 216篇 |
2013年 | 287篇 |
2012年 | 455篇 |
2011年 | 453篇 |
2010年 | 247篇 |
2009年 | 256篇 |
2008年 | 384篇 |
2007年 | 387篇 |
2006年 | 451篇 |
2005年 | 397篇 |
2004年 | 344篇 |
2003年 | 344篇 |
2002年 | 308篇 |
2001年 | 151篇 |
2000年 | 140篇 |
1999年 | 135篇 |
1998年 | 86篇 |
1997年 | 55篇 |
1996年 | 71篇 |
1995年 | 55篇 |
1994年 | 47篇 |
1993年 | 40篇 |
1992年 | 100篇 |
1991年 | 88篇 |
1990年 | 70篇 |
1989年 | 75篇 |
1988年 | 54篇 |
1987年 | 85篇 |
1986年 | 70篇 |
1985年 | 71篇 |
1984年 | 45篇 |
1983年 | 44篇 |
1982年 | 25篇 |
1981年 | 23篇 |
1979年 | 45篇 |
1977年 | 22篇 |
1976年 | 26篇 |
1974年 | 28篇 |
1973年 | 28篇 |
1972年 | 22篇 |
1971年 | 34篇 |
排序方式: 共有7509条查询结果,搜索用时 0 毫秒
991.
992.
993.
Christian Toso José Oberholzer Ion Ceausoglu Frédéric Ris Bertrand Rochat Annemie Rehor Pascal Bucher Christine Wandrey Ute Schuldt Jacques Belenger Domenico Bosco Philippe Morel David Hunkeler 《Transplant international》2003,16(6):405-410
To date, encapsulated grafts have usually been implanted in the peritoneal cavity. This site is, however, not ideal, mainly because of its low blood supply. We have investigated the feasibility of intra-portal injection of (400 microm) microcapsules in the pig. Ten-thousand microcapsules per kilogram body weight were injected into six Large White pigs. Portal pressure, various biological tests, portographies and liver histology were recorded before and at various time points after injection. As a result, portal pressure increased after injection (15+/-2.3 vs 8.7+/-1.7 mmHg) but remained within an acceptable range (<20 mmHg) and returned to normal values at 3 months (8.5+/-3.7 mmHg). During the 3-month follow up, liver function and liver tests remained stable. Portographies showed a homogenous implantation of the capsule, with the portal flow always directed to the liver. At histological examination after 3 months the capsules demonstrated various degrees of fibrosis. We can thus conclude that these results demonstrate that intra-portal injection of microcapsules is feasible in a large-animal model. Hemodynamic, biological and radiological results are similar to those observed in clinical free-islet transplantation. 相似文献
994.
J Chapal D Hillaire-Buys G Bertrand D Pujalte P Petit and MM Loubatieres-Mariani 《Fundamental & clinical pharmacology》1997,11(6):537-545
Summary— Adenosine tri- and diphosphate (ATP and ADP) and their structural analogues stimulate insulin secretion from the isolated perfused rat pancreas, an effect mediated by P2Y -purinoceptor activation. Concerning the base moiety of the nucleotide, it was previously shown that purine but not pyrimidine nucleoside triphosphates were active and that substitution on purine C2 with the 2-methylthio group greatly enhanced the potency. In this study, we further analyze the consequences of ribose and polyphosphate chain modifications. Modifications in 2' and 3' position on the ribose led to a decrease in insulin response when bulky substitutions were made: indeed, 2'-deoxy ATP was similar in activity to ATP, whereas arylazido-aminopropionyl ATP (ANAPP3 ) was weakly effective and trinitrophenyl ATP (TNP-ATP) was inactive. Substitution on the /phosphorus of the triphosphate chain led to a decrease (y-anilide ATP) or no change ( y-azido ATP) in potency; the replacement of the bridging oxygen between β and /phosphorus by a peroxide group did not significantly change the activity, whereas substitution by a methylene group completely abolished stimulation of insulin secretion. As for the phosphorothioate analogues, adenosine-5'-0-(3-thiotriphosphate) (ATP)S) induced an insulin response similar to that produced by ATP, whereas adenosine-5'-0-(2-thiodiphosphate) (ADP/JS) was about 100-fold more potent than ATP, as previously shown. In conclusion, two structural features seem to have a strategic importance for increasing the insulin secretory activity of ATP analogues: substitution at the C2 position on the adenine ring of ATP and modifications of the polyphosphate chain at the level of the β phosphorus. 相似文献
995.
Bertrand Millat 《Cirugía espa?ola》2008,84(6):293-295
996.
Ubiquitin-proteasome-dependent muscle proteolysis responds slowly to insulin release and refeeding in starved rats 总被引:1,自引:1,他引:0
997.
J Billette R Guardo M Bertrand M Lafortune F Roberge 《Pacing and clinical electrophysiology : PACE》1979,2(1):20-27
A cardiac stimulator is described which combines the ease of operation required in clinical investigations, particularly endocavitary studies of cardiac arrhythmias, and the versatility needed in a research context. This instrument uses a microcomputer to control two independent optically-isolated stimulation ports which can be addressed either independently or jointly to stimulate at two different sites. The main software module operates as a cascade of ten real time pulse generators with individually presettable parameters: amplitude, duration, period, initial delay, periodic and cyclic modifiers, triggering mode, etc. A simple interactive procedure allows the operator to define a stimulation protocol either by accessing the generator structure directly, or by calling any of five pre-programmed stimulation protocols. With this combination, the instrument can provide a large variety of pulse patterns. The operator can intervene at any time during stimulation to change parameter values or modify the pulse pattern. Concurrently with stimulation, the instrument generates time-codes to help relate cardiac responses recorded on paper chart and magnetic tape, and reference them to specific events. The instrument can be readily expanded by the addition of parallel microprocessor modules; other real time tasks such as acquisition and processing of cardiac responses can thus be incorporated. 相似文献
998.
999.
1000.