全文获取类型
收费全文 | 1056篇 |
免费 | 58篇 |
国内免费 | 262篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 56篇 |
妇产科学 | 10篇 |
基础医学 | 144篇 |
口腔科学 | 5篇 |
临床医学 | 98篇 |
内科学 | 343篇 |
皮肤病学 | 5篇 |
神经病学 | 66篇 |
特种医学 | 24篇 |
外科学 | 75篇 |
综合类 | 146篇 |
现状与发展 | 1篇 |
预防医学 | 38篇 |
眼科学 | 59篇 |
药学 | 144篇 |
中国医学 | 34篇 |
肿瘤学 | 124篇 |
出版年
2023年 | 6篇 |
2022年 | 14篇 |
2021年 | 43篇 |
2020年 | 23篇 |
2019年 | 20篇 |
2018年 | 15篇 |
2017年 | 18篇 |
2016年 | 29篇 |
2015年 | 53篇 |
2014年 | 39篇 |
2013年 | 49篇 |
2012年 | 114篇 |
2011年 | 121篇 |
2010年 | 69篇 |
2009年 | 76篇 |
2008年 | 92篇 |
2007年 | 87篇 |
2006年 | 109篇 |
2005年 | 96篇 |
2004年 | 76篇 |
2003年 | 49篇 |
2002年 | 46篇 |
2001年 | 23篇 |
2000年 | 28篇 |
1999年 | 10篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 8篇 |
1995年 | 14篇 |
1994年 | 7篇 |
1993年 | 12篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
排序方式: 共有1376条查询结果,搜索用时 0 毫秒
101.
102.
103.
目的:探讨终末期肝病患者肾脏损坏的临床与肾脏病理学改变之间的联系.方法:回顾性分析45例在北京地坛医院住院期间死于终末期肝病患者的临床与尸解资料,研究肾脏损坏临床与肾脏病理学改变之间的联系.结果:45例患者均无明确的泌尿系统疾病和高血压、糖尿病等全身性疾病病史,其中30例(66.7%)有肾功能不全表现,几乎所有患者均有不同程度的腹水(44/45,98%),其中合并有腹腔感染的患者发生肾功能不全的风险明显增高(X2=8.332,P=0.004,OR=7.2,95%CI:1.75-29.6),而消化道出血、肝性脑病与肾功能不全的发生无相关性.临床无论是否有肾功能不全表现,绝大多数患者(41/45,91.1%)均有不同程度的肾脏病理学改变,其中表现为肾功能衰竭的有31例(68.9%),慢性肾小球肾炎的有7例(15.6%),化脓性肾炎的有2例(4.4%),无明显病理学改变5例(11.1%).结论:终末期肝病患者发生肾衰竭后,病情危重、进展快,可能同时合并有肾前性及肾性病因及诱因,且病理学多有器质性改变. 相似文献
104.
急性胰腺炎中全身炎症反应综合征与抗炎症反应综合征 总被引:1,自引:0,他引:1
急性胰腺炎是一种常见的急重症,被公认为是炎症紊乱的过程.早期暴发性的促炎细胞因子释放引起全身炎症反应综合征,导致多器官功能障碍综合征引起死亡.后期由于大量的抗炎细胞因子,引发抗炎症反映综合征,机体免疫功能受到抑制,诱发感染,进而形成毒血症.因此,重新建立SIRS/CARS的平衡对急性胰腺炎患者发病过程及转归有着重要的临床意义.本文就急性胰腺炎引起的SIRS、CARS有关参与冈子及机制做一综述. 相似文献
105.
Direct effects of dobutamine on the coronary microcirculation: comparison with adenosine using myocardial contrast echocardiography. 总被引:10,自引:0,他引:10
Jian-Ping Bin D Elizabeth Le Ananda R Jayaweera Matthew P Coggins Kevin Wei Sanjiv Kaul 《Journal of the American Society of Echocardiography》2003,16(8):871-879
The direct effects of dobutamine on capillary blood volume (VOL) and blood flow velocity (VEL) are not known. We hypothesized that these would be more similar to that of adenosine because of its effects on the beta(2) receptors on the coronary circulation. A total of 9 open-chest anesthetized dogs were studied after placement of 2 noncritical stenoses at rest and during separate intracoronary administrations of 5 microg/kg(-1)/min(-1) of adenosine and 2 microg/kg(-1)/min(-1) of dobutamine. VOL and VEL were measured using myocardial contrast echocardiography, wall thickening with 2-dimensional echocardiography, and myocardial blood flow (MBF) with radiolabeled microspheres. Dobutamine increased the rate-pressure product significantly, whereas adenosine had no effect on the rate-pressure product. In the normal myocardium, adenosine had no effect on VOL and increases in MBF were all a result of increases in VEL. Dobutamine also caused mostly an increase in VEL and only a 30% increase in VOL indicating modest capillary recruitment. In the bed with stenosis both drugs attenuated increase in MBF by the same amount, which was associated with an attenuation in the increase in VEL secondary to a 15% increase in capillary resistance because of capillary derecruitment. The MBF-wall thickening relation was described for both drugs by the same function: y = 1 - exp(x) with wall thickening being significantly higher for dobutamine compared with adenosine for each level of MBF. We conclude that the increase in MBF in the normal myocardium with intracoronary dobutamine occurs mostly from an increase in VEL rather than from an increase in VOL. In the bed with a noncritical stenosis, the increases in MBF and VEL are similar for both drugs. Similar to intracoronary adenosine, intracoronary dobutamine also caused capillary derecruitment distal to a noncritical coronary stenosis. 相似文献
106.
Yu-Qing Zhang Yan Ma Yun-Yue Xia Wei-De Shen Jian-Ping Mao Ren-Yu Xue 《Journal of controlled release》2006,115(3):307-315
When silk fiber derived from Bombyx mori was subjected to degumming treatments twice in water and subsequent degraded processing in slightly alkaline aqueous solution under high-temperature and high-pressure, the water-soluble silk sericin peptides (SS) with different molecular mass from 10 to 70 kDa were obtained. The sericin peptides could be conjugated covalently with insulin alone with cross-linking reagent glutaraldehyde. The physicochemical properties of the silk sericin-insulin (SS-Ins) conjugates were determined by Enzyme-Linked Immunosorbent Assay (ELISA). The biological activities of SS-Ins bioconjugates were investigated in vitro and in vivo. The results in human serum in vitro indicated that the half-life of the synthesized SS-Ins derivatives was 2.3 and 2.7 times more than that of bovine serum albumin-insulin (BSA-Ins) conjugates and intact insulin, respectively. The pharmacological activity of SS-Ins bioconjugates lengthened to 21 h in mice in vivo, which was over 4 times longer than that of the native insulin. The immunogenicity of silk sericin and the antigenicity of SS-Ins derivatives were not observed in both rabbits and mice. The bioconjugation of insulin with silk sericin protein evidently improved both physicochemical and biological stability of the polypeptide. 相似文献
107.
正常人外周血淋巴细胞凋亡受体的表达与细胞凋亡的关系 总被引:2,自引:0,他引:2
本研究检测凋亡受体Fas、TNFRⅠ、TNFRⅡ在人外周血淋巴细胞(PBL)增殖过程中的表达情况及其细胞周期特异性,并探讨其与凋亡受体途径介导的细胞周期特异性细胞凋亡的关联性。应用双参数流式细胞术检测人外周血淋巴细胞在G0期和经植物凝集素刺激(PHA)进入细胞周期后Fas、TNFRⅠ、TNFRⅡ的表达情况以及细胞周期特异性,同时检测肿瘤坏死因子-α、抗Fas抗体诱导人外周血淋巴细胞的凋亡。结果表明:经植物凝集素刺激24小时后的外周血淋巴细胞Fas、TNFRⅠ、TNFRⅡ表达率较G0期外周血淋巴细胞分别增加了(35.55±6.63)%,(30.63±2.66)%,(26.62±5.14)%,均具有显著性差异(P〈0.01),而且主要表达在G1期;未经植物凝集素刺激的外周血淋巴细胞停留在G0期,TNF-α和anti-Fas诱导后没有发生凋亡,而刺激后进入细胞周期的淋巴细胞经TNF-α和anti-Fas诱导后发生凋亡,其凋亡主要在G1期。结论:凋亡受体在外周血淋巴细胞中的表达与凋亡受体途径介导的细胞凋亡有明显的量效关系,凋亡受体途径介导细胞凋亡的细胞周期特异性与凋亡受体表达的细胞周期特异性有关,细胞凋亡的发生与细胞是否进入细胞周期有关。 相似文献
108.
射频消融作为微创治疗的方法之一,为不能行手术切除的肝脏肿瘤提供了有效的治疗手段.多项研究发现射频消融除了可以使肿瘤发生凝固性坏死,还可以促进肿瘤细胞的凋亡,抑制肿瘤的血管生成,增加肿瘤细胞的免疫原性,提高机体的抗肿瘤免疫力.本文简要论述射频消融治疗肝脏肿瘤的生物学机制. 相似文献
109.
Novel amphiphilic diblock copolymers, cholesterol-end-capped poly(2-methacryloyloxyethyl phosphorylcholine) (CMPC), which have poly(2-methacryloyloxyethyl phosphorylcholine) (poly(MPC)) as hydrophilic segment and cholesterol as hydrophobic segment, was specially designed as drug delivery systems. Fluorescence probe technique and transmission electron microscope (TEM) characterizations indicated that this novel amphiphilic copolymer formed micelles structure in water and the critical micelle concentration (CMC) was determined to be 1.57 x 10(-7) mol/l. A commercial obtained polymeric amphiphiles, Cholesterol end capped PEO (CPEO), which had a similar structure with CMPC, was used as a control in the cytotoxicity test. While CPEO showed obvious cytotoxicity, cytotoxicity of this novel amphiphiles was not observed as indicated by cell culture. Anti-cancer drug adriamycin (ADR) was incorporated into the micelles by oil-in-water method. The size of the drug-containing micelles was less than 200 nm, and the size distribution of the drug-containing micelles showed a narrow and monodisperse unimodal pattern. The release rate of ADR from the nanosphere was slow and the release continued over 7 days and the release rate decreased with the increase of molecular weights of the copolymer and the amount of the drug entrapped. These experimental results suggested that the nanoparticles prepared from CMPC block copolymers could be a good candidate for injectable drug delivery carrier. 相似文献
110.
Lu-Dong Qiao Shan Chen Yun-Hua Lin Jian-Xing Li Wei-Guo Hu Jian-Ping Hou Liang Cui 《International urology and nephrology》2018,50(3):427-432