全文获取类型
收费全文 | 28583篇 |
免费 | 1792篇 |
国内免费 | 601篇 |
专业分类
耳鼻咽喉 | 188篇 |
儿科学 | 614篇 |
妇产科学 | 338篇 |
基础医学 | 3587篇 |
口腔科学 | 459篇 |
临床医学 | 4306篇 |
内科学 | 5147篇 |
皮肤病学 | 165篇 |
神经病学 | 2129篇 |
特种医学 | 2697篇 |
外国民族医学 | 3篇 |
外科学 | 3163篇 |
综合类 | 3397篇 |
现状与发展 | 1篇 |
预防医学 | 899篇 |
眼科学 | 502篇 |
药学 | 1821篇 |
4篇 | |
中国医学 | 713篇 |
肿瘤学 | 843篇 |
出版年
2024年 | 47篇 |
2023年 | 295篇 |
2022年 | 590篇 |
2021年 | 804篇 |
2020年 | 769篇 |
2019年 | 715篇 |
2018年 | 766篇 |
2017年 | 680篇 |
2016年 | 638篇 |
2015年 | 782篇 |
2014年 | 1213篇 |
2013年 | 1523篇 |
2012年 | 1137篇 |
2011年 | 1316篇 |
2010年 | 1114篇 |
2009年 | 1098篇 |
2008年 | 1274篇 |
2007年 | 1327篇 |
2006年 | 1207篇 |
2005年 | 1163篇 |
2004年 | 1107篇 |
2003年 | 960篇 |
2002年 | 899篇 |
2001年 | 915篇 |
2000年 | 744篇 |
1999年 | 678篇 |
1998年 | 715篇 |
1997年 | 693篇 |
1996年 | 647篇 |
1995年 | 633篇 |
1994年 | 565篇 |
1993年 | 448篇 |
1992年 | 416篇 |
1991年 | 351篇 |
1990年 | 316篇 |
1989年 | 278篇 |
1988年 | 244篇 |
1987年 | 213篇 |
1986年 | 182篇 |
1985年 | 281篇 |
1984年 | 187篇 |
1983年 | 130篇 |
1982年 | 180篇 |
1981年 | 136篇 |
1980年 | 127篇 |
1979年 | 92篇 |
1978年 | 85篇 |
1977年 | 73篇 |
1976年 | 72篇 |
1974年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
972.
Xu Dongsheng 《国际检验医学杂志》2011,32(15):1696-1698
During B-cell development and maturation,the antigen receptor,which is encoded by the immunoglobulin heavy-(IgH)and light-chain genes,rearrange to associate one of a number of variable,diverse,andjoining gene segments.Asingle mature Bcell expresses an IgHchain and either a kappa or lambda light 相似文献
973.
974.
Pedersen F Raymond I Mehlsen J Atar D Hildebrandt PR 《The American journal of medicine》2005,118(1):25-31
PURPOSE: Symptoms in patients with heart failure and preserved left ventricular ejection fraction may be caused by isolated diastolic dysfunction. The purpose of this study was to assess the prevalence of diastolic dysfunction as a potential cause of dyspnea in a sample of elderly subjects, as well as of isolated diastolic dysfunction as a potential cause of dyspnea in a subgroup with a preserved left ventricular ejection fraction and normal lung function. METHODS: A total of 152 subjects with dyspnea underwent echocardiography, electrocardiography, and lung function testing. Subjects with normal lung function test results (n = 60) underwent cardiac magnetic resonance imaging, chest radiography, bicycle exercise tests, and blood tests. Left ventricular diastolic function was assessed by a variety of echocardiographic/Doppler techniques. RESULTS: Of 129 subjects with dyspnea, 81 (63%) had signs of lung disease or 'obvious' cardiac disease. In the remaining 48 subjects, 32 (67%) had a potential cardiac/noncardiac cause of dyspnea. In all subjects with dyspnea, 1% to 11% had diastolic dysfunction, and in the 48 remaining subjects, 0% to 10% had isolated diastolic dysfunction, depending on the definition used. CONCLUSION: The frequency of diastolic dysfunction was low in the sample of elderly subjects with dyspnea as well as in the subgroup of persons with no signs of lung disease, left ventricular systolic dysfunction, atrial fibrillation, or valvular heart disease. Diastolic dysfunction was infrequent as a possible cause of dyspnea, and coexisting potential causes of dyspnea were often present. 相似文献
975.
目的探讨IL-4、IL-13在变应性鼻炎发病机制中的作用及IL-4、IL-13拮抗剂治疗变应性鼻炎的临床意义。方法取52例变应性鼻炎(实验组)及25例无过敏性疾病(对照组)患者的外周血,用PMA(phorbol 12-myristate 13-acetate佛波酯)+inomycin(离子霉素)及标准化尘螨抗原刺激后经细胞内染色,流式细胞仪检测IL-4、IL-13、IFN-γ的表达细胞百分数,ELISA检测血清IL-4、IL-13含量。结果对照组经标准化尘螨变应原刺激后细胞内测出IFN-γ为0.3%-0.4%,但检测不到IL-4与IL-13,经PMA+inomycin刺激后IFN-γ为5.0%-12.4%、IL-4为0.5%-0.8%、IL-13为0%-0.2%;实验组经标准化尘螨变应原刺激后IFN-γ为0.3%-0.5%、IL-4为0.9%-1.3%、IL-13为0.5%-0.9%,经PMA+inomycin刺激后IFN-γ为17.3%-24.0%、IL-4为2.1%-3.5%、IL-13为0.8%-2.0%。实验组血清中IL-4含量为(1.768±0.485)pg/ml、IL-13为(5.427±1.263)pg/ml,对照组IL-4与IL-13含量均低于敏感度。结论IL-4、IL-13在变应性鼻炎患者中表达升高,参与了变态反应过程,为临床应用IL-4、IL-13拮抗剂治疗变应性鼻炎提供了依据。 相似文献
976.
Detection of minimal residual disease in B-lineage acute lymphoblastic leukaemia by quantitative flow cytometry 总被引:5,自引:0,他引:5
Nahla Farahat Alison Morilla Kwasi Owusu-Ankomah Ricardo Morilla C. Ross Pinkerton Jennie G. Treleaven Estella Matutes Ray L. Powles & Daniel Catovsky 《British journal of haematology》1998,101(1):158-164
The clinical significance of detecting minimal residual disease (MRD) in B-lineage acute lymphoblastic leukaemia (ALL) was evaluated by quantitative flow cytometry using a combination of TdT with CD10 and CD19. 53 patients with B-cell precursor ALL were followed during and after completion of treatment (median follow-up 23 months). Nine patients relapsed and MRD had been detected in six of them, 5–15 weeks before relapse despite morphological complete remission. 43 patients remain in clinical remission and in none of these was MRD detected. Disease-free survival based on the detection of MRD by flow cytometry showed a statistically significant difference between both groups ( P < 0.0001). The absence of MRD correlates with a low relapse rate, whereas the presence of MRD predicted early relapse. This study has shown that flow cytometry can improve the morphologic assessment of bone marrow (BM) remission status in B-lineage ALL. The finding of < 5% blasts in BM aspirates did not correlate with 'true' remission in a proportion of cases as residual leukaemic blasts were detected by flow cytometry in nine samples from six patients. On the other hand, the presence of > 5% blasts assessed by morphology was not necessarily a feature of relapse in five patients as these cells were shown to have a phenotype identical to normal TdT-negative B-cell precursors. Quantitative flow cytometry was more informative than conventional morphology to assess remission status and showed a strong correlation with clinical outcome. This methodology is useful to define MRD in the majority of patients with B-lineage ALL and should be tested in prospective clinical trials. 相似文献
977.
Stimulated parotid salivary flow studies were performed on 20 non-diabetic subjects and on 30 patients with insulin-dependent diabetes mellitus who had been screened for autonomic neuropathy using tests of cardiovascular reflexes. Electrical gustometry was performed to detect the taste threshold. The stimulated parotid salivary flow rates of diabetics with no autonomic neuropathy or early parasympathetic autonomic dysfunction alone were similar to those of non-diabetic subjects. Diabetic patients with established parasympathetic autonomic neuropathy had significantly higher salivary flow rates as did those with combined sympathetic and parasympathetic neuropathies. Taste thresholds did not correlate either with the duration of the diabetes or with the presence of autonomic neuropathy. The cause of the increased salivary flow associated with diabetic autonomic neuropathy is unclear. It may represent the removal of a neural inhibitory mechanism which modulates salivary flow, or the effects of long-standing diabetes on salivary secretion. 相似文献
978.
Aims/hypothesis To test the hypothesis that adipose tissue lipolysis is enhanced in patients with Type 2 diabetes mellitus, we examined the effect of exercise on regional adipose tissue lipolysis and fatty acid mobilisation and measured the acute effects of exercise on the co-ordination of adipose tissue and splanchnic lipid metabolism.Methods Abdominal, subcutaneous adipose tissue and splanchnic lipid metabolism were studied by conducting measurements of arterio-venous concentrations and regional blood flow in six overweight Type 2 diabetic subjects before, during and after exercise.Results Exercise induced an increase in adipose tissue lipolysis and fatty acid release. However, the increase in adipose tissue blood flow was small, limiting fatty acid mobilisation from this tissue. Some of the fatty acids were released in excess in the post-exercise phase. The splanchnic fatty acid uptake was unchanged during the experiment but splanchnic ketogenesis increased in the post-exercise phase. The arterial glucose concentration decreased during exercise and continued to decrease afterwards, indicating an imbalance between splanchnic glucose production and whole-body glucose utilisation.Conclusions/interpretation Regional subcutaneous, abdominal adipose tissue lipolysis is no higher in patients with Type 2 diabetes than in young, healthy subjects. Exercise stimulates adipose tissue lipolysis, but due to an insufficient increase in blood flow, a high fraction of the fatty acids liberated by lipolysis cannot be released to the blood. Splanchnic glucose release is smaller than whole-body glucose utilisation during exercise and post-exercise recovery.Abbreviations ICG indocyanine green - 3-OHB 3-hydroxybutyrate - TAG triacylglycerol - VO2,max peak oxygen consumption 相似文献
979.
Hiroki Ikenaga Jun Yoshida Atsushi Hayashi Takafumi Nagaura Satoshi Yamaguchi Florian Rader Robert J. Siegel Saibal Kar Takahiro Shiota 《JACC: Cardiovascular Interventions》2019,12(2):140-150