全文获取类型
收费全文 | 4703篇 |
免费 | 295篇 |
国内免费 | 72篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 80篇 |
妇产科学 | 26篇 |
基础医学 | 1050篇 |
口腔科学 | 34篇 |
临床医学 | 383篇 |
内科学 | 738篇 |
皮肤病学 | 63篇 |
神经病学 | 206篇 |
特种医学 | 55篇 |
外科学 | 242篇 |
综合类 | 459篇 |
现状与发展 | 1篇 |
预防医学 | 1122篇 |
眼科学 | 36篇 |
药学 | 359篇 |
中国医学 | 31篇 |
肿瘤学 | 170篇 |
出版年
2024年 | 2篇 |
2023年 | 40篇 |
2022年 | 113篇 |
2021年 | 178篇 |
2020年 | 137篇 |
2019年 | 116篇 |
2018年 | 112篇 |
2017年 | 136篇 |
2016年 | 149篇 |
2015年 | 156篇 |
2014年 | 257篇 |
2013年 | 336篇 |
2012年 | 291篇 |
2011年 | 281篇 |
2010年 | 217篇 |
2009年 | 229篇 |
2008年 | 209篇 |
2007年 | 223篇 |
2006年 | 214篇 |
2005年 | 199篇 |
2004年 | 156篇 |
2003年 | 152篇 |
2002年 | 102篇 |
2001年 | 101篇 |
2000年 | 109篇 |
1999年 | 95篇 |
1998年 | 94篇 |
1997年 | 76篇 |
1996年 | 53篇 |
1995年 | 69篇 |
1994年 | 71篇 |
1993年 | 51篇 |
1992年 | 53篇 |
1991年 | 44篇 |
1990年 | 44篇 |
1989年 | 39篇 |
1988年 | 28篇 |
1987年 | 28篇 |
1986年 | 18篇 |
1985年 | 11篇 |
1984年 | 15篇 |
1983年 | 10篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1973年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有5070条查询结果,搜索用时 250 毫秒
1.
《Journal of microbiology, immunology, and infection》2021,54(5):983-986
In an investigation of six anti-SARS-CoV-2 antibody kits with different target antigen and methodology, each kit showed comparable performance. As false-positive reactions occurred independently with different kits, specificity increased to 100% when pairs of kits were used. With three-kit combination, both sensitivity (99.1%) and specificity (100%) increased. 相似文献
2.
《Journal of endodontics》2020,46(6):846-857
IntroductionThis study assessed the cleaning, shaping, and disinfection abilities of 2 instrumentation systems in molar root canals using a novel correlative analytical approach.MethodsThe root canals from extracted mandibular and maxillary molars with apical periodontitis were pair matched according to anatomic similarities as determined by micro–computed tomographic analysis and prepared with either XP-endo Shaper (FKG Dentaire, La Chaux-de-Fonds, Switzerland) (n = 16) or Reciproc Blue (VDW, Munich, Germany) (n = 16) instruments and 2.5% sodium hypochlorite irrigation. Pre- and postpreparation micro–computed tomographic scans were used to identify and calculate the unprepared surface areas (shaping), which were histobacteriologically evaluated for the presence of residual bacteria (disinfection) and pulp tissue remnants (cleaning) in each canal third.ResultsUnprepared canal surface areas for XP-endo Shaper and Reciproc Blue in the full canal length were approximately 26% and 19% (P < .05), respectively (30% and 23% in the apical part of the canal, P > .05). Preparation with Reciproc Blue resulted in 37.5% canals free of bacteria in all sections examined and 56% in the apical sections only. XP-endo Shaper resulted in 44% canals free of bacteria in all sections, and 56% in the apical part of the canal only. Pulp tissue remnants were not observed in 31% (all canal sections) and 50% (apical canal sections) of specimens from both instrument systems. No significant differences were observed between instruments when comparing the amount of pulp tissue remnants and the number of cases negative for bacteria and tissue remnants (P > .05).ConclusionsAlthough the Reciproc Blue instrument had superior shaping ability in comparison with XP-endo Shaper, both systems performed similarly in cleaning and disinfecting root canals. Irregular canals and difficult-to-reach areas were not thoroughly cleaned and disinfected by any of the tested systems. 相似文献
3.
4.
R. Watson T. Kozlowski V. Nickeleit J. T. Woosley J. L. Schmitz S. L. Zacks J. H. Fair D. A. Gerber K. A. Andreoni 《American journal of transplantation》2006,6(12):3022-3029
Antibody-mediated rejection (AMR) after liver transplantation is recognized in ABO incompatible and xeno-transplantation, but its role after ABO compatible liver transplantation is controversial. We report a case of ABO compatible liver transplantation that demonstrated clinical, serological and histological signs of AMR without evidence of concurrent acute cellular rejection. AMR with persistently high titers of circulating donor specific antibodies resulted in graft injury with initial centrilobular hepatocyte necrosis, fibroedematous portal expansion mimicking biliary tract outflow obstruction, ultimately resulting in extensive bridging fibrosis. Immunofluorescence microscopy demonstrated persistent, diffuse linear C4d deposits along sinusoids and central veins. Despite intense therapeutic intervention including plasmapheresis, IVIG and rituximab, AMR led to graft failure. We present evidence that an antibody-mediated alloresponse to an ABO compatible liver graft can cause significant graft injury independent of acute cellular rejection. AMR shows distinct histologic changes including a characteristic staining profile for C4d. 相似文献
5.
作者用自制的[~(125)I]标记激素,参考国外经验,建立了人血清胰岛素抗体、猪胰岛素原抗体和胰多肽抗体等三种放射免疫检测法,并对方法的主要实验条件进行了优选,对方法的质量控制参数作了验证。结果发现:在使用国产胰岛素的糖尿病人血清中,三种抗体的检出率分别为90.8%、48.3%和36.5%;抗体特异性结合值分别为21.2±17.4%、41.8±27.4%和25.6±28.4;而正常人和糖尿病人未用胰岛素者全部为阴性,显示国产胰岛素具有明显的免疫原性。 相似文献
6.
7.
目的分析各种因素对手工凝聚胺试验的影响;方法应用手工凝聚胺(manual polgbrene test,MPT)做交叉配血及抗体筛选试验;结果血液标本、操作手法、凝聚胺试剂、药物(肝素、止血敏、高浓度KCl等)等对试验均有影响;其中以药物、操作手法影响较大,可致假阴性和假阳性结果;结论手工凝聚胺试验做交叉配血及抗体筛选时应注意排除药物和操作手法对试验结果的影响。 相似文献
8.
Guerard W. Byrne Johannes M. Schirmer David N. Fass Sumeet S. Teotia Walter K. Kremers Hui Xu Bashoo Naziruddin Henry D. Tazelaar John S. Logan Christopher G. A. McGregor 《American journal of transplantation》2005,5(5):1011-1020
Microvascular thrombosis is a prominent feature in cardiac delayed xenograft rejection (DXR). We investigated the impact of warfarin or low-molecular-weight heparin (LMWH) anti-coagulation on xenograft function using a heterotopic pig-to-primate model. Donor hearts were from CD46 transgenic pigs and baboon immunosuppression included tacrolimus, sirolimus, anti-CD20 and TPC, an alpha-galactosyl-polyethylene glycol conjugate. Three groups of animals were studied. Group 1 (n = 9) was treated with warfarin, Group 2 (n = 13) with LMWH and Group 3, received no anti-coagulant drugs. The median duration of xenograft function was 20 days (range 3-62 days), 18 days (range 5-109 days) and 15 days (range 4-53 days) in Groups 1 to 3 respectively. Anti-coagulation achieved the targeted international normalized prothrombin ratio (INR) and anti-factor Xa levels consistent with effective in vivo therapy yet, no significant impact on median xenograft function was observed. At rejection, a similar histology of thrombosis and ischemia was apparent in each group and the levels of fibrin deposition and platelet thrombi in rejected tissue was the same. Anti-coagulation with warfarin or LMWH did not have a significant impact on the onset of DXR and microvascular thrombosis. However, a role for specific anti-coagulant strategies to achieve long-term xenograft function cannot be excluded. 相似文献
9.
10.
酶联免疫吸附试验、间接荧光抗体试验、间接免疫过氧化物酶染色试验诊断人体旋毛虫病的初步研究 总被引:2,自引:0,他引:2
用ELISA、IFA和IIP试验检测11例旋毛虫病人血清特异性抗体,阳性率分别为72.72%、81.82%和81.82%。它们之间无统计学差异,3项试验结果间存在良好一致性。 同时检测了30份健康献血员血清和20例其他寄生虫病人血清(包括华支睾吸虫病、四川肺吸虫病、日本血吸虫病、包虫病和阿米巴肝脓肿),旋毛虫病人组的ELISA、IFA和IIP阳性率明显为高。 由于3项免疫学试验均具有较好的特异性和灵敏性,故可以单独或联合用于人体旋毛虫病的诊断和流行病学调查。 相似文献