全文获取类型
收费全文 | 6380篇 |
免费 | 460篇 |
国内免费 | 168篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 36篇 |
妇产科学 | 13篇 |
基础医学 | 978篇 |
口腔科学 | 409篇 |
临床医学 | 330篇 |
内科学 | 838篇 |
皮肤病学 | 52篇 |
神经病学 | 1237篇 |
特种医学 | 203篇 |
外科学 | 427篇 |
综合类 | 703篇 |
预防医学 | 505篇 |
眼科学 | 708篇 |
药学 | 310篇 |
中国医学 | 126篇 |
肿瘤学 | 83篇 |
出版年
2024年 | 11篇 |
2023年 | 93篇 |
2022年 | 363篇 |
2021年 | 400篇 |
2020年 | 215篇 |
2019年 | 176篇 |
2018年 | 171篇 |
2017年 | 192篇 |
2016年 | 214篇 |
2015年 | 251篇 |
2014年 | 350篇 |
2013年 | 441篇 |
2012年 | 304篇 |
2011年 | 345篇 |
2010年 | 283篇 |
2009年 | 285篇 |
2008年 | 264篇 |
2007年 | 238篇 |
2006年 | 212篇 |
2005年 | 197篇 |
2004年 | 175篇 |
2003年 | 152篇 |
2002年 | 138篇 |
2001年 | 133篇 |
2000年 | 79篇 |
1999年 | 94篇 |
1998年 | 98篇 |
1997年 | 96篇 |
1996年 | 107篇 |
1995年 | 83篇 |
1994年 | 72篇 |
1993年 | 61篇 |
1992年 | 72篇 |
1991年 | 76篇 |
1990年 | 54篇 |
1989年 | 51篇 |
1988年 | 50篇 |
1987年 | 52篇 |
1986年 | 63篇 |
1985年 | 57篇 |
1984年 | 40篇 |
1983年 | 35篇 |
1982年 | 34篇 |
1981年 | 45篇 |
1980年 | 31篇 |
1979年 | 18篇 |
1978年 | 16篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1973年 | 5篇 |
排序方式: 共有7008条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The aim of this study was to design a new intravenous blood–gas exchange device and to estimate the design characteristics
of the device with a dimensionless function by using a substance that can be used instead of bovine blood. In addition, the
characteristics of oxygen transfer were estimated using empirical formulas and the reliability of the equations was ascertained
by comparing their output with an experiment performed using bovine blood. The dimensionless function was derived using distilled
water and bovine blood to estimate the oxygen transfer rate. Using the derived equations, the calculated oxygen transfer rates
for bovine blood and distilled water were similar for Reynolds numbers ranging from 0.7 to 7.0. Therefore, it is possible
to estimate the oxygen transfer rate in bovine blood, which is a non-Newtonian fluid, using distilled water, which is a Newtonian
fluid. Moreover, it was possible to verify the related equations because the oxygen transfer rate could be estimated using
the derived equations, according to the diameters of the various device modules. 相似文献
5.
放射性肝纤维化过程的定量研究 总被引:6,自引:0,他引:6
经^60Coγ线照射大鼠肝区,通过光镜、电镜和图像分析仪、宣研究了照后1年肝脏的病理改变。结果表明,30Gy组在照射后1年内逐渐发生了放射性肝纤维化病变。在肝纤维化发生过程中,肝细胞内糖原颗凿含量进行性减少,间质中胶原纤维含量进行性增加,网状纤维于照射1-3个月呈进行性增加。 相似文献
6.
Xin Mei Jiang Akio Ohnishi Tatsunori Yamamoto Yoshiyuki Murai Akira Awaya Masato Ikeda 《Acta neuropathologica》1995,90(2):130-134
One of the pyrimidine compounds, 2-piperadino-6-methyl-5-oxo-5,6-dihydro(7H)pyrrolo[3,4-d]pyrimidine (MS-818), has neurotropic effects in vitro. Therefore, we studied the effect of MS-818 on the regeneration of the peroneal nerve in C57BL/6J mice after a crush injury. Two test groups, which received a daily intraperitoneal injection of 5 mg/kg or 10 mg/kg MS-818, respectively, were compared with controls, which received daily intraperitoneal injections of physiological saline, over a 14-day period. The maximum foot-width ratio (crushed side/uncrushed side) was obtained on days 1, 8 and 14 after the crush injury, and the various morphometric parameters were evaluated at both 5 and 10 mm distal to the proximal portion of the crush site. The significant effects of MS-818 included a larger maximum foot width (P<0.04) and a greater number of unmyelinated axons per nerve at both levels (P<0.003) in both test groups than in controls. MS-818 had no significant effects on body weight, the increase of total transverse fascicular area after the crush injury, the total number of myelinated fibers with their size distributions, or the number of nuclei of Schwann cells and macrophages. Therefore, we conclude that MS-818 promotes axonal sprouting and elongation after a crush injury in mice. 相似文献
7.
8.
目的:探讨家兔阴茎感觉神经来源。方法:健康成年雄性新西兰白兔12只,随机均分为两组:每组6只,A组在左侧脊神经上记录,B组在右侧脊神经上记录。对家兔阴茎施加不同大小的机械刺激,用神经单纤维记录技术,在同侧S1~S4脊神经上记录单纤维放电。结果:通过对家兔阴茎施加各种不同机械刺激,在同侧S2~S3脊神经上能记录到放电,S1、S4脊神经上未能记录到放电。左侧脊神经放电纤维数量分别为:S2:39.67±3.14,S3:21.00±2.19;右侧脊神经放电纤维数量分别为:S2:40.00±3.16,S3:19.67±2.58,左右侧差异无显著性(P>0.05)。结论:家兔阴茎皮肤感觉来源于S2~S3脊神经。 相似文献
9.
Jean-Fran ois Marini Fran oise Pons Jocelyne Leger Nathalie Loffreda Monique Anoal Martine Chevallay Michel Fardeau Jean J. Leger 《Neuromuscular disorders : NMD》1991,1(6):397-409
The expression of MHC isoforms in the skeletal muscles of nine patients with Duchenne muscular dystrophy (DMD) (from 2.5 to 15 yr of age) and three DMD carriers was studied using different specific anti-MHC MAbs. We also analyzed muscle fiber size and fiber reactivity with acridine orange and/or with a surface antigen marker. One-quarter of all fibers of DMD patients, or less with age, were of normal size and contained only adult slow MHC. Half of the muscle fibers contained adult and developmental MHCs. Only half of these fibers were representative of an active regenerative process. MHC co-expression also altered the proportion of normal fast or slow fibers. Adult fast MHCs were expressed as unique MHC only in small and very small fibers in the oldest DMD patients. In DMD carrier muscles, the greatest alterations in MHC expression were observed in patients with the most reduced dystrophin expression. However, MHC changes in dystrophin-positive fibers were similar to those observed in dystrophin-free fibers. In conclusion, disruptions or delays in the switching of all genes coding for adult fast and slow MHC and developmental MHC coincided with dystrophin deletion and with perturbations in its expression. 相似文献
10.
妇女妊娠期及分娩前后子宫肌层的超微结构研究 总被引:2,自引:0,他引:2
扫描电镜(SEM)和透射电镜(TEM)观察证明,妇女非妊娠期子宫肌层内存在有胶原纤维网(CFN)。妊娠中期和晚期及分后CFN出现以时相性崩解和重建为主要特征的改建过程以适应子宫生理性能的巨大变化和功能需要。平滑肌细胞,成纤维细胞,肌纤维母细胞,巨噬细胞,中性白细胞及肥大细胞参与改建过程。它们既参与CFN的溶解和吸收,又参与其重新形成,显示双重形态和功能。还对CFN改建的机理,参与细胞间的相互作用, 相似文献