全文获取类型
收费全文 | 5869篇 |
免费 | 508篇 |
国内免费 | 322篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 63篇 |
妇产科学 | 373篇 |
基础医学 | 442篇 |
口腔科学 | 78篇 |
临床医学 | 599篇 |
内科学 | 434篇 |
皮肤病学 | 39篇 |
神经病学 | 158篇 |
特种医学 | 435篇 |
外国民族医学 | 4篇 |
外科学 | 307篇 |
综合类 | 1260篇 |
预防医学 | 386篇 |
眼科学 | 30篇 |
药学 | 642篇 |
2篇 | |
中国医学 | 611篇 |
肿瘤学 | 828篇 |
出版年
2024年 | 10篇 |
2023年 | 62篇 |
2022年 | 137篇 |
2021年 | 221篇 |
2020年 | 173篇 |
2019年 | 180篇 |
2018年 | 169篇 |
2017年 | 220篇 |
2016年 | 266篇 |
2015年 | 225篇 |
2014年 | 405篇 |
2013年 | 412篇 |
2012年 | 425篇 |
2011年 | 488篇 |
2010年 | 410篇 |
2009年 | 359篇 |
2008年 | 313篇 |
2007年 | 328篇 |
2006年 | 283篇 |
2005年 | 236篇 |
2004年 | 180篇 |
2003年 | 150篇 |
2002年 | 151篇 |
2001年 | 96篇 |
2000年 | 91篇 |
1999年 | 51篇 |
1998年 | 44篇 |
1997年 | 57篇 |
1996年 | 54篇 |
1995年 | 34篇 |
1994年 | 44篇 |
1993年 | 39篇 |
1992年 | 35篇 |
1991年 | 28篇 |
1990年 | 27篇 |
1989年 | 24篇 |
1988年 | 27篇 |
1987年 | 22篇 |
1986年 | 19篇 |
1985年 | 31篇 |
1984年 | 25篇 |
1982年 | 16篇 |
1981年 | 11篇 |
1980年 | 17篇 |
1979年 | 14篇 |
1978年 | 14篇 |
1977年 | 11篇 |
1976年 | 12篇 |
1974年 | 15篇 |
1973年 | 13篇 |
排序方式: 共有6699条查询结果,搜索用时 15 毫秒
41.
Andrew A. Fulvini Akaash Tuteja Jianhua Le Barbara A. Pokorny Jeanmarie Silverman Doris Bucher 《Vaccine》2021,39(3):545-553
The only effective measure to decrease morbidity and mortality caused by the influenza virus in the human population is worldwide vaccination. Vaccination produces neutralizing antibodies that target the HA1 subunit of the HA (hemagglutinin) protein and are strain specific. The effectiveness of new influenza vaccines are linked to two factors, the correct prediction of the circulating strains in the population in a particular season and the concentration of the HA1 protein in the vaccine formulation. With the advent of the licensing of quadrivalent vaccines, pharmaceutical manufacturers are under considerable pressure due to time constraints and dedicated resources to deliver 194–198 million doses (2020–2021 U.S. market) of vaccine. Considering the valuable resources needed to produce the influenza vaccine in a timely manner, the efficient quantitation of the HA1 protein (the main component in the influenza vaccine) is required. Currently the only method approved by regulatory agencies for quantitation of the HA antigen in vaccines is the single radial immunodiffusion assay (SRID), an antibody dependent assay that is not time efficient. Time efficient methods that are antibody independent e.g. reverse phase-high performance liquid chromatography (RP-HPLC) or size exclusion-HPLC (SE-HPLC) are available. An improved method implementing reverse phase-ultra performance liquid chromatography (RP-UPLC) has been developed to quantitate the HA1 protein antigen present in the high yield reassortant vaccine seed viruses from influenza A H1N1 and H3N2 subtypes harvested from inoculated embryonated chicken eggs. This method differentiates between high yield and lower yielding reassortants in order to select the best vaccine candidate seed virus with the highest growth ‘in ovo’. This direct capability to monitor the HA1 concentration of potential reassortant seed viruses and to choose the best yielding HA influenza reassortant when faced with multiple viral seed candidates provides a major advantage on the industrial scale to the influenza vaccine process. 相似文献
42.
43.
软骨种子细胞的老化和缺乏是限制软骨组织工程在临床应用的瓶颈问题。本文概述了目前对软骨种子细胞研究的两个方面 :扩大种子细胞的来源及预防和延缓种子细胞功能老化 ,并展望软骨组织工程在监床的应用前景。 相似文献
44.
为探讨B超与放射免疫分析诊断卵巢癌的临床价值 ,对 45例卵巢癌患者行B超及放射免疫分析血液CEA、CA12 5、TSGF。提示B超与CA12 5、TSGF ,CEA联合检查 ,可提高对卵巢癌的诊断率 相似文献
45.
对 30 2例胃癌术前检测CA5 0、CA199、CA12 5、CA72 4、CEA、β2 -MG、SA、Fer等 8种肿瘤标志物 ,并按年龄、胃癌病期及病理分类分组分析。结果 :(1) 30 2例胃癌血清中 8种肿瘤标志物总的阳性率依次为 β2 -MG6 5 .9%、CA19932 .1%、CA72 42 9.5 %、SA2 4.5 %、CA12 5 16 .9%、CEA13 .2 %、CA5 0 11.6 %、Fer(- )。 (2 ) 8种肿瘤标志物阳性率与年龄大小均无关。 (3) β2 -MG、CA72 4、CA12 5、CA199、SA、CEA、在Ⅲ、Ⅳ期病例中均较敏感 ,且随病期增加 ,阳性率增高。 (4 )CA199和CA72 4对腺癌、β2 -MG和SA对低分化腺癌、β2 -MG和CA72 4对粘液癌、混合型癌阳性率较高。提示血清测β2 -MG、CA199、CA72 4、SA、CA12 5对胃癌的辅助诊断有一定应用价值 相似文献
46.
子宫腺肌病误诊原因分析及术前诊断临床探讨 总被引:5,自引:0,他引:5
目的;探讨子宫腺肌病误诊原因及近年术前诊断研究进展,方法;对我院近10年收治的197例腺肌病患者的临床资料进行回顾性分析。结果:1990年元月至1997年12月128例腺肌病患者术前,术后诊断符合率仅为29.7%,术后误诊,漏诊率达70.3%,1998年元月至1999年12月69例术前经测定血清CA125及 腔双氧水造影后误诊,漏诊率降为27.5%术前主要误诊为子宫肌瘤或(和)子宫内膜异位症,结论 相似文献
47.
48.
Graduated compression stockings in the prevention of deep vein thrombosis in patients with acute myocardial infarction 总被引:5,自引:0,他引:5
Venous volume (venous capacity) of the calf is low in patientswith acute myocardial infarction, who also have a high riskof deep vein thrombosis (DVT). The effect of graduated compressionstockings on the venous volume and on the incidence of DVT wastherefore studied in 80 patients aged 70 years and above withacute myocardial infarction. Graduated compression stockingswere randomly fitted to one leg, the other serving as a control,after which the venous volume was measured by strain gauge plethysmography.The incidence of DVT was measured by the 125I fibrinogen uptaketest. Venous volume was significantly higher in legs treatedwith graduated compression stockings compared to control legs.DVT developed in eight control legs but not in any leg treatedwith graduated compression stockings (P = 0.003). DVT was alsosignificantly more frequent in women compared to men and themajority of DVT developed in legs with very low venous volumevalues. 相似文献
49.
L. Prat G. Torres I. Carrió M. Roca V. Riambau L. Berná M. Estorch I. Ferrer C. Garcia 《European journal of nuclear medicine and molecular imaging》1993,20(12):1141-1145
To test iodine-125 labelled low-density lipoprotein (125I-LDL), polyclonal indium-111 labelled immunoglobulin G (111In-IgG) and iodine-125 labelled endothelin-1 uptake in metabolically active atheromatous plaques after arterial wall injury, we performed balloon de-endothelialization of carotid arteries or abdominal aortas in 24 New Zealand male rabbits which were fed with a normal diet (n=14) or a hypercholesterolaemic diet (n=10) after surgery. Six weeks later the animals were injected with 200 Ci of (125I-LDL), and/or with 100 Ci of 111In-IgG or with 9 Ci of 125I-endothelin-1. Forty-eight hours later the animals were sacrificed. Carotid arteries and aortas were removed, counted and fixed for autoradiography and light microscopy examination. Contralateral carotid arteries and thoracic aortas served as controls.Significant 111In-IgG uptake was observed in the injured arteries at autoradiography, with localization mainly in the healing edges, and at well counting. The percentage of the injected dose per gram (%D.inj/g) was 0.0188±0.06 versus 0.0059±0.003 in controls (P< 0.05). There was no difference in 111In-IgG uptake between arteries with injury alone and those with active atheroma formation at the site of the injury. Significant (125I-LDL), uptake was observed only when lipid deposition was present at light microscopy (%D.inj/g of 0.0024±0.0005 vs 0.0010±0.0003 in controls, P < 0.05). 125I-endothelin-1 accumulation was observed in four of five injured aortas both at autoradiography, with diffuse localization, and at well counting (%D.inj/g of 0.0012±0.0004 in the abdominal aortas vs 0.0008±0.0003 in the thoracic aortas).Polyclonal IgG may accumulate in injured arteries without active atheroma formation. Inflammatory reaction at the site of the injury may cause 111In-IgG uptake independently of atheromatous plaque formation. LDL accumulation takes place only with active atheroma formation at the site of the injury. Use of labelled peptides such as endothelin-1 may provide further insight into the mechanisms of atheromatous plaque formation. 相似文献
50.
Ulrich Schwabe Volker Lenschow Dieter Ukena David R. Ferry Hartmut Glossmann 《Naunyn-Schmiedeberg's archives of pharmacology》1982,321(1):84-87
Summary N6-p-Hydroxyphenylisopropyladenosine (HPIA) has been labelled with carrier-free Na[125I] to very high specific activity (2,175 Ci/mmol) and used as an agonist ligand to characterize Ri adenosine receptors in rat cerebral cortex membranes. The binding is saturable, reversible, stereospecific and dependent on protein concentration. The specific binding at 37°C was of high affinity with an equilibrium dissociation constant KD of 0.48 nmol/l and was saturable with 0.23 pmol of [125I]HPIA per mg of protein. The rate constant of association, k1, was 3.25×108 l mol–1 min–1 and that of dissociation, k2, 0.0110 min–1 yielding a t1/2 of 63 min. In competition experiments the (–)isomer of N6-phenylisopropyladenosine (PIA) was 16-fold more potent than the (+)isomer in competing for the binding sites. Specific binding was most effectively displaced by N6-cyclohexyladenosine (CHA, ki=0.26 nmol/l), (–)PIA (ki=0.33 nmol/l) and HPIA (ki=0.52 nmol/l), whereas 5-N-ethylcarboxamidoadenosine (NECA, ki-1.42 nmol/l) was less effective. The methylxanthines 3-isobutyl-1-methylxanthine (IBMX), theophylline and caffeine which have been classified as adenosine antagonists had ki values between 5–34 mol/l. Binding of [125I]HPIA was regulated by guanine nucleotides and divalent cations. The results indicate that [125I]HPIA labels Ri adenosine receptors in rat brain membranes. 相似文献