全文获取类型
收费全文 | 7514篇 |
免费 | 385篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 143篇 |
妇产科学 | 149篇 |
基础医学 | 834篇 |
口腔科学 | 128篇 |
临床医学 | 461篇 |
内科学 | 2331篇 |
皮肤病学 | 73篇 |
神经病学 | 752篇 |
特种医学 | 183篇 |
外科学 | 942篇 |
综合类 | 42篇 |
一般理论 | 5篇 |
预防医学 | 515篇 |
眼科学 | 250篇 |
药学 | 470篇 |
1篇 | |
中国医学 | 21篇 |
肿瘤学 | 545篇 |
出版年
2023年 | 55篇 |
2022年 | 126篇 |
2021年 | 262篇 |
2020年 | 121篇 |
2019年 | 230篇 |
2018年 | 246篇 |
2017年 | 185篇 |
2016年 | 186篇 |
2015年 | 213篇 |
2014年 | 249篇 |
2013年 | 400篇 |
2012年 | 567篇 |
2011年 | 566篇 |
2010年 | 334篇 |
2009年 | 293篇 |
2008年 | 504篇 |
2007年 | 499篇 |
2006年 | 485篇 |
2005年 | 437篇 |
2004年 | 318篇 |
2003年 | 359篇 |
2002年 | 301篇 |
2001年 | 116篇 |
2000年 | 100篇 |
1999年 | 81篇 |
1998年 | 66篇 |
1997年 | 53篇 |
1996年 | 42篇 |
1995年 | 33篇 |
1994年 | 27篇 |
1993年 | 18篇 |
1992年 | 58篇 |
1991年 | 42篇 |
1990年 | 35篇 |
1989年 | 40篇 |
1988年 | 36篇 |
1987年 | 33篇 |
1986年 | 24篇 |
1985年 | 21篇 |
1984年 | 15篇 |
1983年 | 10篇 |
1982年 | 19篇 |
1981年 | 13篇 |
1980年 | 13篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 9篇 |
1976年 | 12篇 |
1975年 | 6篇 |
1974年 | 13篇 |
排序方式: 共有7931条查询结果,搜索用时 15 毫秒
81.
82.
83.
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
84.
85.
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
86.
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
87.
88.
89.
Francesco Paolo Caronia Alfonso Fiorelli Mario Santini Sergio Castorina 《General thoracic and cardiovascular surgery》2016,64(10):625-628
Persistent tracheal fistula after tracheostomy decannulation is a recognized sequel to long-term tracheostomy use, causing important morbidity including difficult to vocalization and control of air secretions, recurrent pulmonary infections, and cosmetic and social problems. Herein, we reported a new method for closure of persistent tracheocutaneous fistula with rib cartilages. Compared to other techniques previously reported, the variations of our strategy were the use of temporary metal-covered tracheal stent and the hinged turnover skin bi-flaps reinforced with rib cartilage grafts. Rib cartilages were useful in order to reconstruct the trachea and prevent stenosis. Since it become difficult to obtain the maintenance of the trachea stability until healing of suture was well established, a covered metallic stent was also inserted to avoid flap collapse. The stent was removed 3 months later. Six months follow-up showed normal tracheal patency. 相似文献
90.
Emanuele Angelucci Valeria Santini Anna Angela Di Tucci Giulia Quaresmini Carlo Finelli Antonio Volpe Giovanni Quarta Flavia Rivellini Grazia Sanpaolo Daniela Cilloni Flavia Salvi Giovanni Caocci Alfredo Molteni Daniele Vallisa Maria Teresa Voso Susanna Fenu Lorenza Borin Giancarlo Latte Giuliana Alimena Sergio Storti Alfonso Piciocchi Paola Fazi Marco Vignetti Sante Tura 《European journal of haematology》2014,92(6):527-536