全文获取类型
收费全文 | 6280篇 |
免费 | 332篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 64篇 |
儿科学 | 125篇 |
妇产科学 | 89篇 |
基础医学 | 639篇 |
口腔科学 | 103篇 |
临床医学 | 380篇 |
内科学 | 1923篇 |
皮肤病学 | 62篇 |
神经病学 | 652篇 |
特种医学 | 170篇 |
外科学 | 770篇 |
综合类 | 40篇 |
一般理论 | 5篇 |
预防医学 | 419篇 |
眼科学 | 255篇 |
药学 | 418篇 |
1篇 | |
中国医学 | 16篇 |
肿瘤学 | 511篇 |
出版年
2023年 | 46篇 |
2022年 | 85篇 |
2021年 | 221篇 |
2020年 | 109篇 |
2019年 | 185篇 |
2018年 | 204篇 |
2017年 | 159篇 |
2016年 | 160篇 |
2015年 | 172篇 |
2014年 | 215篇 |
2013年 | 341篇 |
2012年 | 488篇 |
2011年 | 469篇 |
2010年 | 280篇 |
2009年 | 247篇 |
2008年 | 427篇 |
2007年 | 441篇 |
2006年 | 431篇 |
2005年 | 378篇 |
2004年 | 281篇 |
2003年 | 302篇 |
2002年 | 266篇 |
2001年 | 79篇 |
2000年 | 57篇 |
1999年 | 49篇 |
1998年 | 61篇 |
1997年 | 42篇 |
1996年 | 36篇 |
1995年 | 29篇 |
1994年 | 24篇 |
1993年 | 15篇 |
1992年 | 40篇 |
1991年 | 30篇 |
1990年 | 22篇 |
1989年 | 30篇 |
1988年 | 26篇 |
1987年 | 23篇 |
1986年 | 17篇 |
1985年 | 14篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1982年 | 18篇 |
1981年 | 13篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1974年 | 7篇 |
排序方式: 共有6642条查询结果,搜索用时 390 毫秒
61.
62.
P. Cortina Greus J. L. Alfonso Sanchez I. Frasquet Pons C. Saiz Sanchez C. Cortes Vizcaino J. I. Gonzalez Arraez A. Sabater Pons S. Ruiz 《European journal of epidemiology》1992,8(6):770-775
After describing the evolution of mortality from ischaemic cardiopathy (IC) in Spain from 1951 to 1986, which is tending to stabilize in some age groups, and from cerebrovascular accidents (CVA), which is clearly declining, an attempt is made to relate these developments to the prevalence of the main risk factors (hypertension, cholesterol, tobacco) associated with IC and CVA. Certain advances, though of a limited number, have been made in recent years in the control of arterial hypertension in Spain, although campaigns on a national scale as in other countries have not been carried out. Regarding alimentary factors, there is an obvious increase in the consumption of food rich in proteins and animal fats, abandoning to a great extent the traditional Mediterranean diet, with health care action being limited to the improvement of nutrition education of the public. Furthermore, the consumption of tobacco has been increasing in Spain during the study period in spite of health legislation in force in recent years.It is therefore deduced that there is no obvious relationship between mortality due to IC and CVA and the prevalence of the main risk factors associated with these diseases, especially when taking into account that preventive actions on a public health level have been very limited.Corresponding author. 相似文献
63.
64.
We present a 70-year-old woman with pre-B acute lymphoblastic leukemia in whom serial imaging studies showed the development
of multiple vertebral collapse, and communicating superior and inferior Schmorl’s nodes creating a longitudinal channel (”tunneling”
Schmorl’s nodes) through the anterior aspect of T12 to L3 vertebral bodies of her osteoporotic thoracolumbar spine. This was
observed after achieving complete remission of the disease and during maintenance therapy. The finding is felt to be secondary
to iatrogenic exacerbation of osteoporosis.
Received: 26 May 2000 Revision requested: 23 June 2000 Revision received: 10 July 2000 Accepted: 13 July 2000 相似文献
65.
66.
67.
Antonio Greco Mariaenrica Frigione Alfonso Maffezzoli Alessandro Marseglia Alessandra Passaro 《Materials》2014,7(7):5385-5402
This work is aimed to present an innovative technology for the reinforcement of beams for urban furniture, produced by in-mold extrusion of plastics from solid urban waste. This material, which is usually referred to as “recycled plastic lumber”, is characterized by very poor mechanical properties, which results in high deflections under flexural loads, particularly under creep conditions. The Prowaste project, founded by the EACI (European Agency for Competitiveness and Innovation) in the framework of the Eco-Innovation measure, was finalized to develop an innovative technology for selective reinforcement of recycled plastic lumber. Selective reinforcement was carried out by the addition of pultruded glass rods in specific positions with respect to the cross section of the beam, which allowed optimizing the reinforcing efficiency. The reinforcement of the plastic lumber beams with pultruded rods was tested at industrial scale plant, at Solteco SL (Alfaro, Spain). The beams obtained, characterized by low cost and weight, were commercialized by the Spanish company. The present paper presents the most relevant results of the Prowaste project. Initially, an evaluation of the different materials candidates for the reinforcement of recycled plastic lumber is presented. Plastic lumber beams produced in the industrial plant were characterized in terms of flexural properties. The results obtained are interpreted by means of beam theory, which allows for extrapolation of the characteristic features of beams produced by different reinforcing elements. Finally, a theoretical comparison with other approaches which can be used for the reinforcement of plastic lumber is presented, highlighting that, among others, the Prowaste concept maximizes the stiffening efficiency, allowing to significantly reduce the weight of the components. 相似文献
68.
Óscar Núñez Martínez Isabel Marquina Ibáñez Elena Ruiz Bravo-Burguillos Alfonso Encinas Sotillos José Carlos Erdozaín Sosa 《Gastroenterologia y hepatologia》2013
We describe the case of a female patient with a previous diagnosis of primary biliary cirrhosis (PBC) and chronic hepatitis B in inactive phase who developed increased transaminase levels with no evidence of hepatitis B virus reactivation while receiving ursodeoxycholic acid treatment. A liver biopsy showed changes compatible with overlapping autoimmune hepatitis (AIH). Budesonide treatment achieved normalization of transaminase levels. We provide a review of PBC and AIH overlap syndrome and discuss the particular features of this case that led us to this diagnosis, as well as the treatment provided. 相似文献
69.
Julián Castro Castro Jon Rodino Padín Alfonso Pinzón Millán Jesús Patricio Agulleiro Díaz Juan Manuel Villa Fernández Ana Pastor Zapata 《Neurocirugía (Asturias, Spain)》2013,24(1):1-8
ObjectThe use of transpedicular screw fixation has been widely accepted for the treatment of degenerative and traumatic pathology of the lumbar spine. Complications of spinal instrumentation can be serious. Screw misplacement can result in unintended durotomy, nerve root and/or cauda equina injury. In comparison to fluoroscopy-assisted screw placement, computer-assisted image guidance has been shown to achieve overall higher rates of accuracy. The O-arm is able to obtain computed tomography (CT)-type images with multiplanar reconstruction. In this study we evaluated a cohort of patients who underwent posterior lumbar fusion with pedicle screws utilizing the O-arm imaging system.MethodsA retrospective review of 40 consecutive patients who underwent posterior lumbar fusion surgery with O-arm utilization, was performed. The study population included 14 males and 26 females. Age range was 39-85 years with an average of 63.8 years. Twenty one patients had degenerative lumbar stenosis (52.5%) and 19 had spondylolisthesis (47.5%). Intraoperative CT-images were obtained. The mean time for surgery and screw placement was assessed.ResultsA total of 252 pedicle screws were sited using O-arm navigation system, with a mean of 6.3 screws per patient (range 4-10). On the basis of intraoperative CT, 3 screws were redirected, representing a 98.81% accuracy rate.The mean duration of surgery was 157.2 (90-240) minutes and the mean time for screw placement was 7.13 (3.08-15) minutes per screw.Three patients (7.5%) developed superficial wound infections which were treated conservatively. No patients required a return to the operating room because of screw malposition.ConclusionThe use of intraoperative O-arm imaging system with computer-assisted navigation significantly increases the surgical accuracy and safety of pedicle screw placement in lumbar fusion surgery. 相似文献
70.