全文获取类型
收费全文 | 1338491篇 |
免费 | 112526篇 |
国内免费 | 6371篇 |
专业分类
耳鼻咽喉 | 16707篇 |
儿科学 | 43008篇 |
妇产科学 | 36554篇 |
基础医学 | 183621篇 |
口腔科学 | 36295篇 |
临床医学 | 120690篇 |
内科学 | 278506篇 |
皮肤病学 | 31886篇 |
神经病学 | 110501篇 |
特种医学 | 55536篇 |
外国民族医学 | 274篇 |
外科学 | 210337篇 |
综合类 | 31533篇 |
现状与发展 | 2篇 |
一般理论 | 414篇 |
预防医学 | 106630篇 |
眼科学 | 28087篇 |
药学 | 93732篇 |
5篇 | |
中国医学 | 2227篇 |
肿瘤学 | 70843篇 |
出版年
2018年 | 13375篇 |
2017年 | 10632篇 |
2016年 | 12796篇 |
2015年 | 14297篇 |
2014年 | 19946篇 |
2013年 | 29733篇 |
2012年 | 36234篇 |
2011年 | 38885篇 |
2010年 | 24371篇 |
2009年 | 23902篇 |
2008年 | 36365篇 |
2007年 | 38775篇 |
2006年 | 39898篇 |
2005年 | 38491篇 |
2004年 | 36723篇 |
2003年 | 35822篇 |
2002年 | 33832篇 |
2001年 | 66054篇 |
2000年 | 67919篇 |
1999年 | 56593篇 |
1998年 | 16725篇 |
1997年 | 15017篇 |
1996年 | 16016篇 |
1995年 | 16232篇 |
1994年 | 15099篇 |
1993年 | 14153篇 |
1992年 | 47101篇 |
1991年 | 45750篇 |
1990年 | 43972篇 |
1989年 | 41815篇 |
1988年 | 38760篇 |
1987年 | 38082篇 |
1986年 | 35861篇 |
1985年 | 34637篇 |
1984年 | 26358篇 |
1983年 | 22109篇 |
1982年 | 13851篇 |
1981年 | 12447篇 |
1980年 | 11720篇 |
1979年 | 23544篇 |
1978年 | 17072篇 |
1977年 | 14388篇 |
1976年 | 13183篇 |
1975年 | 13722篇 |
1974年 | 16095篇 |
1973年 | 15397篇 |
1972年 | 14173篇 |
1971年 | 13037篇 |
1970年 | 11880篇 |
1969年 | 11102篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
981.
Bronchogenic carcinoma; 12 year review and operative results 总被引:1,自引:0,他引:1
GAGNON ED 《Canadian Medical Association journal》1948,58(1):25-29
982.
David Jiménez Castro Gema Díaz David Martí Carlos Escobar Javier Ortega Sergio García-Rull Joaquin Picher Antonio Sueiro 《Blood coagulation & fibrinolysis》2007,18(2):173-177
This study aimed to determine whether a weight-adjusted dose of subcutaneous enoxaparin is as effective and safe as oral acenocoumarol for the secondary prophylaxis of pulmonary embolism. Three hundred and eighty consecutive noncancer outpatients hospitalized with an episode of symptomatic pulmonary embolism selected treatment with acenocoumarol or enoxaparin at a dose of 1 mg/kg once daily after being informed of the type of administration and expected frequency of laboratory monitoring for both medicinal products. Endpoints were symptomatic recurrent thromboembolic events evaluated by standard objective testing, and a composite endpoint of recurrent venous thromboembolism, major bleeding, and death from any cause. One hundred and ninety-nine patients (52%) chose acenocoumarol therapy and 181 chose enoxaparin monotherapy. Four patients in the enoxaparin group (2.2%) and six patients in the acenocoumarol group (3%) had an objective thromboembolic recurrence (hazard ratio, 1.35; 95% confidence interval, 0.38-4.79; P = 0.64). Nine patients in the enoxaparin group (5.0%) had a hemorrhagic complication compared with 11 in the acenocoumarol group (5.5%) (P = 0.81). The hospital length of stay was shorter with enoxaparin compared with acenocoumarol (11 versus 16 days, P = 0.0001). Enoxaparin is as effective and safe as acenocoumarol in the secondary prevention of recurrent thromboembolic disease and is associated with shorter hospitalization. 相似文献
983.
C Jardim C E Rochitte M Humbert G Rubenfeld D Jasinowodolinski C R R Carvalho R Souza 《The European respiratory journal》2007,29(3):476-481
Pulmonary arterial hypertension (PAH) is a disease of the small vessels in which there is a substantial increase in pulmonary vascular resistance leading to right ventricle failure and death. Invasive haemodynamic evaluation is mandatory not only for diagnosis confirmation but also to address prognosis and eligibility for the use of calcium-channel blockers through an acute vasodilator challenge. Noninvasive surrogate response markers to the acute vasodilator test have been sought. In the present study, the relationship between pulmonary artery distensibility, assessed using magnetic resonance imaging (MRI), and response to acute vasodilator tests was investigated. In total, 19 patients diagnosed with idiopathic PAH without any specific treatment were evaluated. Within a 48-h window after pulmonary artery catheterisation, patients underwent cardiac MRI. Cardiac index, calculated after the determination (invasively and noninvasively) of cardiac output, showed excellent correlation, as did right atrial pressure and right ventricle ejection fraction. Pulmonary artery distensibility was significantly higher in responders. A receiver operating characteristic curve analysis has shown that 10% distensibility was able to differentiate responders from nonresponders with 100% sensitivity and 56% specificity. The present findings suggest that magnetic resonance imaging and pulmonary artery distensibility may be useful noninvasive tools for the evaluation of patients with pulmonary hypertension. 相似文献
984.
985.
986.
987.
Primary squamous cell carcinoma is an extremely rare tumour of the thyroid gland. A case of an elderly lady who was diagnosed to have primary squamous cell carcinoma of the thyroid gland is presented and the role of radiotherapy is discussed. 相似文献
988.
989.
Z D Daniil E Zintzaras T Kiropoulos A I Papaioannou A Koutsokera A Kastanis K I Gourgoulianis 《The European respiratory journal》2007,30(5):957-964
Pleural effusion is a common complication of various diseases. Conventional methods are not always capable of establishing the cause of pleural effusion, so alternative tests are needed. The aim of this study was to explore means of discriminating between different pleural effusion groups, malignant, parapneumonic and tuberculous, based on the combined function of seven biological markers. Adenosine deaminase (ADA), interferon-gamma, C-reactive protein (CRP), carcinoembryonic antigen, interleukin-6, tumour necrosis factor-alpha and vascular endothelial growth factor concentration levels were measured in pleural fluid from 45 patients with malignant, 15 with parapneumonic and 12 with tuberculous pleural effusion. Receiver operating characteristic curve analysis, multinomial logit modelling and canonical variate analysis were applied to discriminate the pleural effusion groups. The three groups could be discriminated successfully using the measured markers. The most important parameters for discrimination were ADA and CRP concentration levels. An individual with an ADA concentration level of >45 U.L(-1) and a CRP concentration of <4 mg.dL(-1) was more likely to belong to the tuberculous pleural effusion group, whereas one with an ADA concentration level of <40 U.L(-1) and a CRP concentration of >6 mg.dL(-1) was more likely to belong to the parapneumonic pleural effusion group, and one with a CRP concentration of <4 mg.dL(-1) to the malignant pleural effusion group. The combination of adenosine deaminase and C-reactive protein levels might be sufficient for discriminating between the three different groups of exudative pleural effusion: malignant, tuberculous and parapneumonic. 相似文献
990.
K Knapczyk M Duda D Czaplicki M Slomczynska 《Experimental and clinical endocrinology & diabetes》2007,115(7):411-416
Steroid hormones play an essential role in the ovarian cyclicity control and the progress of pregnancy. One of the crucial enzymes in the steroidogenesis is 3beta-hydroxysteroid dehydrogenase/Delta5-Delta4 isomerase (3betaHSD). The aim of the present study was to localize both 3betaHSD mRNA and protein in the ovary of pregnant swine. The immunolocalization of 3betaHSD was performed on paraplast sections of follicles and corpora lutea obtained on various days of gestation: 10, 18, 32, 50, 71 and 90 POST COITUM (p.c.). The obtained results were compared with those concerning follicular and luteal development in the ovaries of the cycling pig. Differences in 3betaHSD distribution between the ovarian follicles of cycling and pregnant pigs were concerned mainly in the pattern of immunostaining of the theca interna cells. In the porcine ovaries obtained on various days of pregnancy, some follicles exhibited positive immunostaining in most theca interna cells, while in other follicles this enzyme was expressed only in a relatively small percentage of theca interna cells. In the corpora lutea of the estrous cycle and pregnancy changes in the pattern of immunostaining were observed. At early and mid pregnancy (up to 71 day p.c.) 3betaHSD was observed in the large luteal cells while on day 71 p.c. the enzyme was present exclusively in the small luteal cells. The expression of 3betaHSD mRNA was detected by the use of RT-PCR technique in all investigated samples isolated at different stages of pregnancy. 相似文献