全文获取类型
收费全文 | 2558篇 |
免费 | 234篇 |
国内免费 | 128篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 96篇 |
妇产科学 | 7篇 |
基础医学 | 234篇 |
口腔科学 | 126篇 |
临床医学 | 288篇 |
内科学 | 734篇 |
皮肤病学 | 45篇 |
神经病学 | 129篇 |
特种医学 | 214篇 |
外科学 | 499篇 |
综合类 | 282篇 |
预防医学 | 64篇 |
眼科学 | 29篇 |
药学 | 98篇 |
中国医学 | 20篇 |
肿瘤学 | 44篇 |
出版年
2024年 | 9篇 |
2023年 | 67篇 |
2022年 | 123篇 |
2021年 | 183篇 |
2020年 | 132篇 |
2019年 | 148篇 |
2018年 | 137篇 |
2017年 | 101篇 |
2016年 | 114篇 |
2015年 | 108篇 |
2014年 | 153篇 |
2013年 | 182篇 |
2012年 | 100篇 |
2011年 | 105篇 |
2010年 | 81篇 |
2009年 | 93篇 |
2008年 | 127篇 |
2007年 | 89篇 |
2006年 | 116篇 |
2005年 | 76篇 |
2004年 | 72篇 |
2003年 | 60篇 |
2002年 | 59篇 |
2001年 | 37篇 |
2000年 | 40篇 |
1999年 | 20篇 |
1998年 | 34篇 |
1997年 | 24篇 |
1996年 | 21篇 |
1995年 | 14篇 |
1994年 | 23篇 |
1993年 | 27篇 |
1992年 | 29篇 |
1991年 | 22篇 |
1990年 | 17篇 |
1989年 | 16篇 |
1988年 | 18篇 |
1987年 | 14篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 13篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1980年 | 17篇 |
1979年 | 11篇 |
1978年 | 13篇 |
1977年 | 9篇 |
1976年 | 7篇 |
1974年 | 3篇 |
1973年 | 5篇 |
排序方式: 共有2920条查询结果,搜索用时 0 毫秒
51.
《Expert opinion on biological therapy》2013,13(8):1031-1042
Biochemical, histological and genetic studies using in vitro/in vivo models have demonstrated that pathological calcification of bioprosthetic heart valves (BHV) is regulated by various mechanisms associated with physiological variables. The major objective of this review is to characterize physiological variables involved in BHV calcification. This review examines our understanding of the systemic cellular behavior and physiological regulation processes behind BHV calcification and its clinical applications. 相似文献
52.
B. Kowall N. Lehmann A.A. Mahabadi S. Moebus R. Erbel K.H. Jöckel A. Stang 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(3):228-235
Background and aims
There is controversy on the potentially benign nature of metabolically healthy obesity (MHO), i.e., obese persons with few or no metabolic abnormalities. So far, associations between MHO and coronary artery calcification (CAC), a measure of subclinical atherosclerosis, have mainly been studied cross-sectionally in Asian populations. We assessed cross-sectional and longitudinal MHO CAC associations in a Caucasian population.Methods and results
In the Heinz Nixdorf Recall Study, a population-based cohort study in Germany, CAC was assessed by electron-beam tomography at baseline and at 5-year follow-up. For cross-sectional and longitudinal analyses, we included 1585 participants free of coronary heart disease at baseline, with CAC measurements at baseline and at follow-up, and with either normal weight (BMI 18.5–24.9 kg/m2) or obesity (BMI ≥30.0 kg/m2) at baseline. We used four definitions of MHO. In our main analysis, we defined obese persons as metabolically healthy if they met ≤1 of the NCEP ATP III criteria for the definition of the metabolic syndrome – waist circumference was not taken into account because of collinearity with BMI.Persons with MHO had a higher prevalence of CAC than metabolically healthy normal weight (MHNW) persons (prevalence ratio = 1.59 (95% confidence interval 1.38–1.84) for the main analysis). Persons with MHO had slightly larger odds of CAC progression than persons with MHNW (odds ratios ranged from 1.17 (0.69–1.99) to 1.48 (1.02–2.13) depending on MHO definition and statistical approach).Conclusion
Our analyses on MHO CAC associations add to the evidence that MHO is not a purely benign health condition. 相似文献53.
《Journal of pharmacological sciences》2014,124(2):129-137
Aortic valve calcification can aggravate aortic stenoses, and it is a significant cause of sudden cardiac death. The increasing number of patients with age-related calcification is a problem in developed nations. However, the only treatment option currently available is highly invasive cardiac valve replacement. Therefore, clarification of the etiology of calcification is urgently needed to develop drug therapies and prevention methods. Recent studies have revealed that calcification is not a simple sedimentation of a mineral through a physicochemical phenomenon; various factors dynamically contribute to the mechanism. Further, we are finally beginning to understand the cellular origins of calcification, which had been unclear for a long time. Based on these findings that help to clarify potential drug targets, we expect to establish drug therapies that reduce the stress on patients. In this paper, I introduce the latest findings on cells that are most likely to contribute to calcification and on calcification-related factors that may lead to the development of drug therapies. 相似文献
54.
《Nutrition, metabolism, and cardiovascular diseases : NMCD》2014,24(3):286-293
Background and aimHypothesizing that intrathoracic fat might exert local effects on the coronary vasculature, we assessed the association of intrathoracic fat volume and its two subcomponents with coronary artery calcification (CAC) in 909 relatively healthy Amish adults.Methods and resultsIntrathoracic fat, which is comprised of fat between the surface of the heart and the visceral epicardium (epicardial fat) and fat around the heart but outside of the fibrous pericardium (pericardial fat), was measured from electron beam CT scans. We examined the association between intrathoracic fat volume and cardiovascular disease risk factors in multivariate regression model. Fat volume in the epicardial and pericardial compartments were highly correlated with each other and with body mass index. Neither CAC extent nor CAC presence (Agatston score > 0) was associated with increased intrathoracic fat volume in sex-stratified models adjusting for age (p > 0.10). Intrathoracic fat volume was significantly correlated with higher systolic/diastolic blood pressure, pulse pressure, fasting glucose, insulin, triglyceride and lower high-density lipoprotein cholesterol in sex-stratified models adjusting for age (p < 0.05). However, associations were attenuated after further adjustment for body mass index.ConclusionsThese data do not provide support for a significant role for intrathoracic fat in the development of CAC. 相似文献
55.
YU Yi YAN Kai?ping WANG Yan SUN Shu?qing CHEN Jin LIN Kai?ping YI Jian?wei. 《中华肾脏病杂志》2012,28(11):868-872
Objective To study the relationship between the medial artery calcification and expression of core?binding factor alpha 1 (Cbfα?1) and collagen Ⅱ (ColⅡ) in chronic kidney disease(CKD) stage 5 patients. Methods Pieces of radial arteries were taken from 40 patients with CKD stage 5 during internal arteriovenous fistula operation. Ten patients with subtotal gastrectomy and normal renal function were chosen as control. The vessels were examined for calcification by von Kossa stain and for the presence of Cbfα?1 and ColⅡ by immunohistochemistry. According to von Kossa stain, CKD stage 5 patients were divided into no calcification group, mild?moderate calcification group and severe calcification group. Other related factors including serum calcium,phosphate, intact parathyroid hormone (iPTH), C?reactive protein (CRP), triglyceride(TG), cholesterol(TC) and low?density lipoproteins(LDL) were also detected. Results Seventeen (42.5%) of CKD Stage 5 patients showed vascular calcification, while calcification was not found in controls. Most calcification occurred in medial layer.Positive immunohistochemical staining of core?binding factor and ColⅡ was found in the smooth muscular cell plasma of medial layer in the vessels with calcification. However, above positive staining was also observed in 78.3% of no calcification group. But there was little staining in control group. Positive staining score of Cbfα?1 and ColⅡ in severe calcification group was significantly higher than that in no calcification group. Same findings were obtained in mild?moderate calcification group, but the difference between them was not statistically significant. CRP and Ca×P were positively correlated with staining score of Cbfα?1 and ColⅡ. Serum phosphate was positively correlated with Cbfα?1 (r=0.786, P<0.01) and ColⅡ (r=0.785, P<0.01) respectively. Conclusions 42.5% of CKD stage 5 patients in our group shows vascular calcification, which occurrs mainly in medial layer. High expression of Cbfα?1 and ColⅡ can be observed in vascular calcification of radial arteries, which is earlier than vascular histological changes. Cbfα?1 and ColⅡ may be involved in the development of vascular calcification. 相似文献
56.
Hirotsugu Mihara M.D. Kentaro Shibayama M.D. Kenji Harada M.D. Javier Berdejo M.D. Yuji Itabashi M.D. Raj R. Makkar M.D. Takahiro Shiota M.D. 《Echocardiography (Mount Kisco, N.Y.)》2014,31(5):E142-E144
Paravalvular regurgitation (PVR) after transcatheter aortic valve replacement (TAVR) is one of the major complications with negative clinical prognosis. Therefore, its prediction is important for further improvement of the outcome. We present a case with TAVR, in which we successfully evaluated aortic valve calcification protruding inward and into the left ventricular outflow tract by real time three‐dimensional transesophageal echocardiography, and predicted significant PVR after the procedure. In conclusion, device landing zone calcification protruding inward is a key for the prediction of significant PVR after TAVR. 相似文献
57.
58.
59.
Jyoti Assudani M.B.B.S. Balwinder Singh M.B.B.S. Amena Samar M.B.B.S. Jasleen Pannu M.B.B.S. Amitoj Singh M.B.B.S. Fatemeh Nabavizadeh M.D. Preeti Singh M.D. Kiran K. Sunkavalli M.B.B.S. Navin C. Nanda M.D. 《Echocardiography (Mount Kisco, N.Y.)》2010,27(9):1147-1150
We describe a 77‐year‐old female with hypertrophic cardiomyopathy in whom live/real time three‐dimensional transesophageal echocardiography (3DTEE) provided incremental value over two‐dimensional transthoracic and transesophageal echocardiography (2DTTE, 2DTEE) and three‐dimensional transthoracic echocardiography (3DTTE) in making a more comprehensive assessment and a more confident diagnosis of caseous mitral annular calcification. 3DTEE revealed a portion of the mass to consist of small, multiple, highly echogenic discrete band‐like and punctate areas within a relatively much less echogenic stroma and surrounded by a well defined highly echogenic border. This appearance correlated with the pathological findings of calcific granules/strands located in a liquefied or semiliquefied interior providing a typical toothpaste like appearance. The highly echogenic outer border represented the residual outer portion or rim of the calcific mass which did not undergo liquefaction. These findings on 3DTEE which correlated with the toothpaste like appearance seen at surgery were not visualized on 2DTTE, 2DTEE, and 3DTTE. (Echocardiography 2010;27:1147‐1150) 相似文献
60.
Koji Yamaguchi M.D. Yoshihide Kato Shogo Maeda Katsutoshi Kitamura 《Journal of gastroenterology》1990,25(4):489-493
A cavernous hemangioma of the stomach in a 41-year-old Japanese man was reported. The patient had numerous hemorrhagic telangiectasias
in the skin and was also diagnosed as having a submucosal tumor of the stomach by an incidental upper gastrointestinal X-ray
study. Wedge resection of the stomach was performed. The tumor was located in the submucosal, proper muscular and subserosal
layers. The resected specimen showed proliferation of vascular spaces lined with a layer of endothelial cells and filled with
red blood cells together with a partially calcified thrombus. The histopathologic diagnosis was cavernous hemangioma of the
stomach with calcified thrombus. The patient has been doing well for twenty years. We report the case and briefly review the
literature.
This study is supported in part by a Grant from Federation of National Public Service and Affiliated Personnel Mutual Aid
Association, Tokyo, Japan. 相似文献