全文获取类型
收费全文 | 39700篇 |
免费 | 4312篇 |
国内免费 | 2670篇 |
学科分类
医药卫生 | 46682篇 |
出版年
2024年 | 114篇 |
2023年 | 689篇 |
2022年 | 1322篇 |
2021年 | 2316篇 |
2020年 | 1705篇 |
2019年 | 1468篇 |
2018年 | 1505篇 |
2017年 | 1361篇 |
2016年 | 1267篇 |
2015年 | 1915篇 |
2014年 | 2394篇 |
2013年 | 2232篇 |
2012年 | 3109篇 |
2011年 | 3403篇 |
2010年 | 2173篇 |
2009年 | 1831篇 |
2008年 | 2214篇 |
2007年 | 2144篇 |
2006年 | 2174篇 |
2005年 | 1847篇 |
2004年 | 1345篇 |
2003年 | 1153篇 |
2002年 | 961篇 |
2001年 | 833篇 |
2000年 | 790篇 |
1999年 | 819篇 |
1998年 | 520篇 |
1997年 | 475篇 |
1996年 | 369篇 |
1995年 | 321篇 |
1994年 | 324篇 |
1993年 | 185篇 |
1992年 | 236篇 |
1991年 | 189篇 |
1990年 | 152篇 |
1989年 | 194篇 |
1988年 | 133篇 |
1987年 | 133篇 |
1986年 | 64篇 |
1985年 | 71篇 |
1984年 | 46篇 |
1983年 | 30篇 |
1982年 | 26篇 |
1981年 | 26篇 |
1980年 | 18篇 |
1979年 | 25篇 |
1978年 | 11篇 |
1975年 | 8篇 |
1974年 | 10篇 |
1973年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
目的探讨肾动脉狭窄支架植入术的临床疗效.方法1997年1月~2004年12月,我院行支架介入治疗肾动脉狭窄27例.对27例术前、术后及随访期内血压、肾功能以及生活质量进行评估,并与同期单纯药物治疗肾动脉狭窄27例进行比较.结果介入组27例植入支架40枚,手术成功24例(88.9%,24/27),失败3例(11.1%,3/27),手术并发症5例(18.5%,5/27).术后在血压下降(包括收缩压舒张压)肌酐下降,肾小球滤过率增加方面,介入组获益率明显优于药物组,两组比较差异均有显著性,术后随访6个月~8年6个月,中位数为1年9个月,介入组有19例能比较健康的生活和工作,药物组仅12例能维持生活和工作.结论支架介入治疗较单纯药物治疗肾动脉狭窄疗效显著. 相似文献
102.
Fan Gao Mark L Latash Vladimir M Zatsiorsky 《Journal of hand therapy》2007,20(4):300-7; quiz 308; discussion 309
The tight coupling between load (L) and grip (G) forces during voluntary manipulation of a hand-held object is well established. The current study is to examine grip-load force coupling when motion of the hand with an object was either self-generated (voluntary) or externally generated. Subjects performed similar cyclic movements of different loads at various frequencies with three types of manipulations: 1) voluntary oscillation, 2) oscillating the right arm via the pulley system by the left leg (self-driven oscillation), and 3) oscillating the arm via the pulley system by another person (other-driven oscillation). During the self-generated movements: 1) the grip forces were larger and 2) grip-load force modulation was more pronounced than in the externally generated movements. The G-L adjustments are not completely determined by the mechanics of object motion; nonmechanical factors related to movement performance, for instance perceptual factors, may affect the G-L coupling. 相似文献
103.
104.
目的 评价血管紧张素Ⅱ、氨甲酰血红蛋白、醛固酮及甲状旁腺激素等在血液净化充分性中的意义。方法 120例慢性肾功能衰竭患者,按采用不同的透析膜分为3组:即聚砜膜、醋酸膜、铜仿膜。用放射免疫法测定其血管紧张素Ⅱ(AngⅡ)及醛固酮(ALD)浓度,化学发光法测甲状旁腺激素(PTH)。采用不同的血流量200ml/min及250ml/min比较。结果 对体内中、小分子物质清除率,聚砜膜〉醋酸膜〉铜仿膜。结论 高血流量、高通透性人工合成聚砜膜,对治疗慢性肾功能衰竭,提高肾功能不全患者的身心健康及生活质量、延长患者生命有很重要的临床意义。 相似文献
105.
Fat-Derived Hormone Adiponectin Combined with FTY720 Significantly Improves Small-for-Size Fatty Liver Graft Survival 总被引:1,自引:0,他引:1
K. Man Y. Zhao A. Xu C.M. Lo K.S.L. Lam K.T. Ng J.W.Y. Ho C.K. Sun T.K. Lee X.L. Li S.T. Fan 《American journal of transplantation》2006,6(3):467-476
Owing to the discrepancy between organ donation and the demand for liver transplantation, expanding the liver donor pool is of vital importance. However, marginal liver grafts, such as small-for-size and/or fatty grafts, were associated with primary graft nonfunction or poor function. Therefore, novel combination therapies to rescue small-for-size fatty liver grafts should be investigated. In this study, we applied a combination therapy using a fat-derived hormone adiponectin (anti-steatosis) plus immunomodulator FTY720 (anti-inflammatory) in a rat liver transplantation model using small-for-size fatty liver grafts, and investigated the underlying protective mechanism such as anti-steatosis, intra-graft energy metabolism, hepatic microcirculatory changes, cell signaling cascades for survival, apoptosis and inflammation. The current study demonstrated that even a single treatment of adiponectin or FTY720 improved the 7-day graft survival from 0% to 62.5% (p = 0.001). The combination therapy significantly increased the 7-day graft survival rate to 100% by remarkable attenuation of graft steatosis and acute phase inflammatory response, significant activation of cell survival Akt pathway and maintenance of intra-graft adenosine triphosphate metabolism and improvement of hepatic microcirculation. In conclusion, the fat-derived hormone adiponectin combined with FTY720 might be a novel combination drug therapy for prevention of small-for-size fatty liver graft injury. 相似文献
106.
107.
108.
Yu-Yan Fan Ryoko Baba Yukiko Nagai Akira Miyatake Naohisa Hosomi Shoji Kimura Guang-Ping Sun Masakazu Kohno Mamoru Fujita Youichi Abe Akira Nishiyama 《Hypertension research》2006,29(3):169-178
Recent studies have suggested that aldosterone plays a role in the pathogenesis of renal injury. In this study, we investigated whether local angiotensin II (Ang II) activity contributes to the progression of renal injury in aldosterone/salt-induced hypertensive rats. Uninephrectomized rats were treated with 1% NaCl in a drinking solution and one of the following combinations for 6 weeks: vehicle (2% ethanol, s.c.; n=9), aldosterone (0.75 mug/h, s.c.; n=8), aldosterone+Ang II type 1 receptor blocker olmesartan (10 mg/kg/day, p.o.; n=8), or aldosterone+olmesartan (100 mg/kg/day, p.o.; n=9). Aldosterone/salt-treated hypertensive rats exhibited severe proteinuria and renal injury characterized by glomerular sclerosis and tubulointerstitial fibrosis. Aldosterone/salt-induced renal injury was associated with augmented expression of angiotensin converting enzyme and Ang II levels in the renal cortex and medullary tissues. Renal cortical and medullary mRNA expression of transforming growth factor-beta (TGF-beta) and connective tissue growth factor (CTGF) as well as the collagen contents were increased in aldosterone/salt-treated hypertensive rats. Treatment with olmesartan (10 or 100 mg/kg/day) had no effect on blood pressure but attenuated proteinuria in a dose-dependent manner. Olmesartan at 10 mg/kg/day tended to decrease renal cortical and medullary Ang II levels, TGF-beta and CTGF expression, and collagen contents; however, these changes were not significant. On the other hand, an ultrahigh dose of olmesartan (100 mg/kg/day) significantly decreased these values and ameliorated renal injury. These data suggest that augmented local Ang II activity contributes, at least partially, to the progression of aldosterone/salt-dependent renal injury. 相似文献
109.
失血性休克大鼠肠上皮细胞线粒体DNA腺苷三磷酸酶6,8基因表达及线粒体功能的改变 总被引:1,自引:0,他引:1
目的 探讨失血性休克大鼠肠上皮细胞线粒体DNAATPase 6 ,8基因表达及线粒体功能的改变 ,为阐述休克肠道靶学说和线粒体能量代谢提供分子生物学基础。 方法 2 4只Wistar大鼠随机分为休克前组和休克 1,2 ,3,4 ,5h组。采用RT -PCR方法观察线粒体ATPase 6 ,8mRNA量的改变。用透射电镜观察、生物体视学测量线粒体形态 ,用Clark氧电极测线粒体呼吸功能。 结果 失血性休克 1,2h ,ATPase 6 ,8基因表达增强 ,以后渐减弱 ,至休克 5h表达最低 ,ATPase 6 ,8基因表达分别降为正常的 6 9.3%和 78.4 % (P <0 .0 1和P <0 .0 5 )。失血性休克 2h和5h ,线粒体平均截面积、长径、面密度、体密度均显著增加 (P <0 .0 1) ,休克 5h时分别为休克前的2 .0 ,1.4 5 ,1.4 7,2 .2 2倍。休克 5h ,线粒体比表面和数密度分别下降 32 %和 2 4 % (P <0 .0 1和P <0 .0 5 ) ,嵴和基质破坏明显。失血性休克后肠上皮细胞线粒体呼吸控制率和氧化磷酸化效率比休克前显著降低 (P <0 .0 1)。 结论 失血性休克时大鼠肠上皮细胞线粒体DNAATPase 6 ,8基因表达下调 ,线粒体呼吸功能出现障碍 ,线粒体超微结构发生了改变 相似文献
110.
目的:了解长期服用抗精神病药的慢性精神分裂症住院患者迟发性运动障碍(TD)的预后。方法:对以往诊断为TD的54例住院患者TD症状进行6年随访。结果:42.6%患者TD症状改善,35.2%患者症状不变,22.2%患者症状恶化。服用新型非典型抗精神病药者TD症状改善较明显。患者的年龄、性别、目前药物剂量、药物剂量的改变、首次用药年龄、累计服药时间及总病程对TD症状的改善无影响。结论:长期用药患者TD症状仍可有所改善,新型非典型抗精神病药物可能改善TD症状。 相似文献