全文获取类型
收费全文 | 15123篇 |
免费 | 1483篇 |
国内免费 | 1177篇 |
专业分类
耳鼻咽喉 | 84篇 |
儿科学 | 184篇 |
妇产科学 | 175篇 |
基础医学 | 1843篇 |
口腔科学 | 275篇 |
临床医学 | 2147篇 |
内科学 | 2371篇 |
皮肤病学 | 139篇 |
神经病学 | 872篇 |
特种医学 | 610篇 |
外国民族医学 | 13篇 |
外科学 | 1289篇 |
综合类 | 2561篇 |
现状与发展 | 4篇 |
一般理论 | 3篇 |
预防医学 | 922篇 |
眼科学 | 378篇 |
药学 | 1555篇 |
20篇 | |
中国医学 | 975篇 |
肿瘤学 | 1363篇 |
出版年
2024年 | 53篇 |
2023年 | 275篇 |
2022年 | 667篇 |
2021年 | 842篇 |
2020年 | 613篇 |
2019年 | 567篇 |
2018年 | 596篇 |
2017年 | 524篇 |
2016年 | 463篇 |
2015年 | 703篇 |
2014年 | 889篇 |
2013年 | 744篇 |
2012年 | 1081篇 |
2011年 | 1217篇 |
2010年 | 775篇 |
2009年 | 608篇 |
2008年 | 821篇 |
2007年 | 736篇 |
2006年 | 738篇 |
2005年 | 740篇 |
2004年 | 516篇 |
2003年 | 495篇 |
2002年 | 422篇 |
2001年 | 348篇 |
2000年 | 374篇 |
1999年 | 350篇 |
1998年 | 199篇 |
1997年 | 204篇 |
1996年 | 185篇 |
1995年 | 164篇 |
1994年 | 145篇 |
1993年 | 102篇 |
1992年 | 106篇 |
1991年 | 71篇 |
1990年 | 89篇 |
1989年 | 60篇 |
1988年 | 46篇 |
1987年 | 54篇 |
1986年 | 38篇 |
1985年 | 34篇 |
1984年 | 30篇 |
1983年 | 25篇 |
1982年 | 9篇 |
1981年 | 5篇 |
1978年 | 4篇 |
1976年 | 5篇 |
1975年 | 7篇 |
1973年 | 8篇 |
1972年 | 4篇 |
1968年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
Bone-specific antibodies in sera from patients with celiac disease: characterization and implications in osteoporosis 总被引:5,自引:0,他引:5
Sugai E Cherñavsky A Pedreira S Smecuol E Vazquez H Niveloni S Mazure R Mauriro E Rabinovich GA Bai JC 《Journal of clinical immunology》2002,22(6):353-362
Osteopenia and osteoporosis are well-known complications detected in celiac disease patients with still obscure pathogenesis. In the present study we investigated the presence of circulating anti-bone autoantibodies in patients with celiac disease and explored their role in the associated bone disease. We evaluated serum samples from 33 patients at the time of diagnosis and from 20 of them after treatment. Sera from patients with inflammatory bowel disease (n = 9), nonceliac osteoporotic (n = 18), and healthy individuals (n = 10) were used as controls. The presence of IgA specific anti-bone antibodies was first investigated using indirect immunofluorescence on cryosections of fetal rat tibia (20-day pregnancy). Furthermore, samples were homogenized and total tissue extracts were subjected to Western blot analysis to confirm immunoreactivity. At diagnosis, sera from 51.5% (17/33) of celiac patients had antibodies that recognized antigenic structures in chondrocytes and the extracellular matrix along mature cartilage, bone interface, and perichondrium of fetal rat bone. Among controls, only two osteoporotic patients showed very low titles of anti-bone autoantibodies. The immunostaining was localized in areas where an active mineralization process occurred and was similar to the distribution of the native bone tissue transglutaminase. The frequency of patients with positive baseline titers of anti-bone antibodies diminished significantly after treatment (P = 0.048). Western blot assays confirmed the presence of autoantibodies in sera from patients with a positive immunofluorescence staining. Autoantibodies recognized a major protein band on tissue extracts with a molecular weight of 77–80 kDa, which could be displaced when sera were preadsorbed with human recombinant tissue transglutaminase. We provide original evidence that patients with celiac disease have IgA-type circulating autoantibodies against intra- and extracellular structures of fetal rat tibia. Our findings suggest that these antibodies recognize bone tissue transglutaminase as the autoantigen, and based on the localization of the immunoreactivity we speculate that they might have an active role in the pathophysiology of celiac disease-associated bone complications. 相似文献
63.
Genetic Conservation of Hemagglutinin Gene of H9 Influenza Virus in Chicken Population in Mainland China 总被引:1,自引:0,他引:1
The hemagglutinin (HA) genes of 12 H9N2 influenza virus strains isolated from chickens in Mainland China during the period 1995–2002 were genetically analyzed. All the isolates possessed the same amino acid motif -R-S-S-R/G-L- at the cleavage site of HA. Except for the conserved amino acids, as is the case in the other avian influenza viruses, located in the receptor binding site, all of the 12 isolates possessed N at amino acid position 183; A, T, or V at position 190; K at position 137, whereas the representative strains of the other lineage (except Dk/HK/Y280/97-like lineage) virus of H9N2 viruses had H, E, and R at these positions respectively. These could be considered as the partial molecular markers of the H9 viruses isolated from chickens in Mainland China. Phylogenetic analyses showed HA genes of these isolates belonged to that of A/duck/Hong Kong/Y280/97-like virus lineage. No A/quail/Hong Kong/Gl/97-like virus was found in chicken, population since the outbreak of H9N2 influenza in Mainland China in 1992. The available evidence indicates that HA genes of H9 influenza virus circulating in Mainland China during the past years were well conserved. 相似文献
64.
Bai Stephen A. Walle U. Kristina Walle Thomas 《Journal of pharmacokinetics and pharmacodynamics》1985,13(3):229-241
The intravenous and oral dose kinetics of propranolol were studied in the dog both in a fasted state and immediately after a meal consisting of 100 g of cooked beef liver. Fifty Ci of3H-propranolol was administered intravenously simultaneously with a 40-mg oral dose of unlabeled propranolol. Plasma3H-propranolol was measured by specific extraction and liquid scintillation spectrometry, and unlabeled plasma propranolol was determined by gas chromatography-mass spectrometry. Feeding significantly reduced (25%) the elimination half-life and increased (52%) the systemic clearance of intravenous propranolol. The increase in the systemic clearance of propranolol after feeding was mostly due to an increase (60%) in apparent hepatic blood flow, which appeared to remain elevated for 5–7 hr. The meal had no influence on the apparent volume of distribution or plasma binding. Feeding did not affect the area under the concentration-time curve of oral propranolol, but significantly delayed the rate of oral propranolol absorption, shifting the time to reach peak plasma levels from 60 to 158 min. The results of this study suggest that feeding alters the disposition of propranolol in the dog by producing a sustained increase in hepatic blood flow.This work was supported by National Institute of Health grants GM 07534, GM 20387, and HL 29566. 相似文献
65.
催经止孕药Ru-486的临床药代动力学 总被引:4,自引:1,他引:3
应用高效液相色谱法(HPLC)研究了抗孕激素药,Ru-486的临床药代动力学。六名志愿受试者,一次口服Ru-486 50毫克后测得该药的药代动力学各项参数,血药半寿期t 1/2 33.0小时,一级消除速率常数Kel 0.021 hr~(-1),血药表观容积Vd 120.1 Liter,体内血药总廓清率Cl2.5 Liter/hr,药-时曲线下面积Auc 19825.1 ng/ml/hr。实验表明,服药后一小时血药浓度迅即达高峰,随后转入消除期,血浆药物浓度在消除相的头4~8小时消除较快,而后逐渐减慢,持续24小时,到48小时血药浓度已较低(0.15±0.07μg/ml)。 相似文献
66.
目的了解上海市预防接种工作人员疑似预防接种异常反应(Adverse events following immunization,AEFI)监测的知识和态度以及影响AEFI报告的因素。方法采用方便抽样在上海市所有459个预防接种门诊选择预防接种工作人员开展问卷调查,分析AEFI监测知识得分(满分6分)和态度,采用多因素Logistic回归分析AEFI报告的影响因素。结果1379名调查对象的AEFI监测知识平均得分为3.30±1.31分;认为开展AEFI监测有必要、报告AEFI是自身职责、AEFI监测是额外工作负担的调查对象分别占98.84%、92.75%、30.38%。69.62%的调查对象近1年报告过AEFI;社区接种门诊、免疫规划专职人员、近1年接受过AEFI培训、AEFI监测知识得分高的调查对象报告AEFI的比例高[OR(95%CI):19.55(14.16-26.98)、1.95(1.45-2.64)、3.14(1.76-5.59)、1.91(1.38-2.63)]。结论上海市预防接种工作人员AEFI监测知识水平不高,对AEFI监测存在一定认识误区;需加强AEFI监测培训,进一步提高其AEFI报告意识。 相似文献
67.
68.
目的:探讨肝肺综合征的X线表现。方法:对18例肝肺综合征(Hepato pulmonary Syndrome,HPS)胸部平片进行了回顾性分析,其中3例行CT扫描。结果:胸部异常16例,X线表现为肺纹理增多、紊乱,其中14例下肺呈结节状阴影,4例伴有斑片状阴影;4例伴有胸腔积液;2例伴有下肺盘状肺不张。3例胸部CT显示病变较平片更多、更清晰。结论:肺基底部结节状阴影是HPS典型X线表现,但不具有特异性。 相似文献
69.
目的:首次研究文冠果果壳的化学成分。方法:采用柱色谱和光谱方法。结果:从文冠果果壳中分得2种甾醇,经鉴定为:(3β,5α,20R,24S)-豆甾-7,反-22-二烯-3-醇和(3β,5α,20R,24R)-豆甾-7-烯-3-醇。结论:2种甾醇在文冠果中均为首次分得。 相似文献
70.
Yu Jin Zhengyi Feng Ju Zhao Jinxiao Hu Yuanyuan Tong Shengwen Guo Peiyao Zhang Liting Bai Yixuan Li Jinping Liu 《Artificial organs》2021,45(1):6-14
Mortality and morbidity of children received veno‐arterial extracorporeal membrane oxygenation (VA‐ECMO) support after cardiac surgery remain high despite remarkable advances in medical management and devices. The purpose of this study was to describe outcomes and risk factors of applying VA‐ECMO in the surgical pediatric population. We retrospectively analyzed 85 consecutive pediatric patients (aged <18 years) who received postcardiotomy VA‐ECMO from January 2010 to December 2018. Median (IQR) age at ECMO implantation in this cohort was 12.7 (6.4, 43.2) months, median weight was 8.5 (6.0, 12.8) kg, mean ECMO duration was 143.2 ± 81.6 hours and mean hospital length of stay was 48.4 ± 32.4 days. Seventy‐five patients (88.2%) were indicated for postcardiotomy cardiogenic shock. The successful ECMO weaning rate was 70.6% and in‐hospital mortality was 52.9%. The most common diagnosis was transposition of great arteries (n = 18, 21.2%), while acute kidney injury occurred most often (n = 64, 75.3%). Multivariate logistic regression analysis showed that thrombocytopenia, hemolysis, and nosocomial infection were positively correlated with in‐hospital mortality. Multivariate Cox proportional hazard regression analysis presented that thrombocytopenia significantly increased the 180‐day mortality in patients with successful weaning. Therefore, multiple factors had adverse effects on prognosis. Patient selection and procedures from ECMO implantation to weaning need to be closely monitored and performed in a timely manner to improve outcome. 相似文献