全文获取类型
收费全文 | 598篇 |
免费 | 42篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 38篇 |
妇产科学 | 1篇 |
基础医学 | 83篇 |
口腔科学 | 17篇 |
临床医学 | 76篇 |
内科学 | 124篇 |
皮肤病学 | 20篇 |
神经病学 | 27篇 |
特种医学 | 124篇 |
外科学 | 39篇 |
综合类 | 12篇 |
预防医学 | 33篇 |
眼科学 | 1篇 |
药学 | 27篇 |
肿瘤学 | 36篇 |
出版年
2021年 | 14篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 7篇 |
2016年 | 8篇 |
2015年 | 13篇 |
2014年 | 14篇 |
2013年 | 20篇 |
2012年 | 9篇 |
2011年 | 16篇 |
2010年 | 32篇 |
2009年 | 40篇 |
2008年 | 11篇 |
2007年 | 31篇 |
2006年 | 18篇 |
2005年 | 19篇 |
2004年 | 13篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 11篇 |
2000年 | 4篇 |
1999年 | 10篇 |
1998年 | 36篇 |
1997年 | 37篇 |
1996年 | 31篇 |
1995年 | 30篇 |
1994年 | 11篇 |
1993年 | 20篇 |
1992年 | 5篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 13篇 |
1988年 | 19篇 |
1987年 | 17篇 |
1986年 | 9篇 |
1985年 | 14篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 13篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1978年 | 9篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1975年 | 5篇 |
1969年 | 2篇 |
1966年 | 2篇 |
1957年 | 2篇 |
1954年 | 2篇 |
排序方式: 共有661条查询结果,搜索用时 15 毫秒
101.
Triple-balloon dilation (TBD) of a variety of luminal structures has been successfully, though infrequently, used. A mathematical model is presented for the selection of balloon sizes, and equations and tables are derived that allow the user to estimate more accurately the size of balloons needed for TBD of structures with large lumina. With TBD, an approximately circular lumen can be formed. Also, TBD allows smaller, higher-pressure balloons to be used instead of single, low-pressure, large balloons. However, multiple puncture sites may be required for TBD. 相似文献
102.
103.
104.
Chronic pancreatitis: ultrasonic features 总被引:2,自引:0,他引:2
A retrospective analysis of 84 ultrasound examinations (in 77 patients) was performed to assess the frequency of sonographic findings in chronic pancreatitis. The findings included: inhomogeneously increased echogenicity in 53% of these examinations, focal or diffuse enlargement in 41%, focal dense echoes in 40%, pseudocyst formation in 21%, and a hypoechoic head mass in 7%. Thirteen per cent of our patients had a normal sonogram. Several presentations of chronic pancreatitis not previously described in the sonographic literature included: pancreatic or common bile duct enlargement or pseudocyst formation with otherwise normal-appearing glands. There was no direct relationship between the presence of focal high-intensity echoes within the pancreatic parenchyma and the presence of radiographic calcification. There was no difference in the frequency of ultrasonic abnormalities between patients with and without clinical evidence of pancreatic insufficiency. These results indicate that the sonographic findings in chronic pancreatitis are significantly more varied than previous reports would indicate. 相似文献
105.
Kinetics of the taste response to chemical stimulation: a theory of acid taste in man 总被引:2,自引:0,他引:2
A L Makhlouf GM BLUM 《Gastroenterology》1972,63(1):67-75
106.
Hamady Dieng Rahman GM Saifur Abu Hassan Ahmad MR Che Salmah Al Thbiani Aziz Tomomitsu Satho Fumio Miake Zairi Jaal Sazaly Abubakar Ronald Enrique Morales 《Asian Pacific Journal of Tropical Biomedicine》2012,2(3):228-232
Objective
To identify the unusual breeding sites of two dengue vectors, i.e. Aedes albopictus (Ae. albopictus) and Aedes aegypti (Ae. aegypti).Methods
During the second half of 2010, we performed an occasional survey in rural (Teluk Tempoyak) and urban (Gelugor) areas of Penang Island, Malaysia, to identify cryptic breeding sites.Results
In the rural area, we found heterogeneous immature stages of Ae. albopictus in the water bowl of an encaged bird. We also observed Ae. aegypti eggs deposited in the flush tank of a toilet in the urban area.Conclusions
It can be concluded that both breeding patterns can increase contact with hosts (humans and birds) and presumably population densities of Ae. albopictus and Ae. aegypti, thereby potentially boosting the risks for spread and transmission of arboviral diseases. 相似文献107.
Brouwer KM van Rensch P Harbers VE Geutjes PJ Koens MJ Wijnen RM Daamen WF van Kuppevelt TH 《Journal of tissue engineering and regenerative medicine》2011,5(6):501-504
Type I collagen is used widely as a biomaterial. The structure of collagenous biomaterials, including pore sizes and general architecture, can be varied by a number of techniques. In this study, we developed a method to construct flat fibrillar type I collagen scaffolds, 6 cm in diameter and with a radially orientated pore structure, by the use of directional freezing. Different methodologies were tested, the optimal one being freezing of a collagen suspension inside-out, using a centrally positioned liquid nitrogen-cooled tube. Pore sizes could be varied by the use of different tube materials. Use of aluminium tubes resulted in radial scaffolds with a pore size of 20-30 μm, whereas use of stainless steel produced radial scaffolds with 70-100 μm pore sizes. Brass- and copper-based tubes produced scaffolds with less homogeneous radial pores, pore sizes being 90-100 and 50-80 μm, respectively. Fibreglass tubes gave even less uniformity (pore size 100-150 μm). Scaffolds were free of cracks, except in case of aluminium. Scaffolds with a radial inner structure may be especially suitable for tissue engineering of organs with a radial scaffold structure, such as the diaphragm. 相似文献
108.
INTRODUCTION
The management of Hirschsprung’s disease continues to evolve. This questionnaire survey aimed to determine current surgical management strategies for Hirschsprung’s disease in Britain.SUBJECTS AND METHODS
The survey was sent electronically to all British paediatric surgeons. Initial questions explored individual experience and regional service provision. Additional questions, reserved for surgeons who perform definitive Hirschsprung’s disease surgery, addressed specific clinical scenarios.RESULTS
Surveys were sent to 142 surgeons yielding 85 responses. After exclusions, 64 surveys from 21 centres were analysed. Forty-seven respondents worked in centres with designated ‘Hirschsprung’s disease surgeons’. Forty respondents perform definitive Hirschsprung’s disease surgery. In a well neonate with left-sided Hirschsprung’s disease, 34 of 40 surgeons favour primary pull-through following bowel decompression with rectal washouts; 35 of 40 surgeons aim to perform definitive surgery at less than 3 months of age, with 17 favouring laparoscopic-assisted Soave–Boley and 15 favouring an open Duhamel pull-through. Of the 40 surgeons, 36 use a staged approach to right-sided/total colonic Hirschsprung’s disease with 23 favouring a Duhamel or Long Duhamel pull-through.CONCLUSIONS
The primary pull-through, using an open Duhamel or laparoscopic-assisted Soave–Boley technique, during the first 3 months of life, has become the operative strategy of choice in rectosigmoid Hirschsprung’s disease in Britain. Marked variation in practice remains for right-sided Hirschsprung’s disease. 相似文献109.
S Thavagnanam SN Christie GM Doherty PV Coyle MD Shields LG Heaney 《Acta paediatrica (Oslo, Norway : 1992)》2010,99(3):394-398
Aim: The aim of this study was to determine if asthmatic children have viruses more commonly detected in lower airways during asymptomatic periods than normal children. Methods: Fifty‐five asymptomatic children attending elective surgical procedures (14 with stable asthma, 41 normal controls) underwent non‐bronchoscopic bronchoalveolar lavage. Differential cell count and PCR for 13 common viruses were performed. Results: Nineteen (35%) children were positive for at least one virus, with adenovirus being most common. No differences in the proportion of viruses detected were seen between asthmatic and normal ‘control’ children. Viruses other than adenovirus were associated with higher neutrophil counts, suggesting that they caused an inflammatory response in both asthmatics and controls (median BAL neutrophil count, 6.9% for virus detected vs. 1.5% for virus not detected, p = 0.03). Conclusions: Over one‐third of asymptomatic children have a detectable virus (most commonly adenovirus) in the lower airway; however, this was not more common in asthmatics. Viruses other than adenovirus were associated with elevated neutrophils suggesting that viral infection can be present during relatively asymptomatic periods in asthmatic children. 相似文献
110.
Dr Lynne Jones OBE MRCPsych Joseph B Asare GM FRCPsych Mustafa El Masri MD Andrew Mohanraj MBBS Hassen Sherief MD Mark van Ommeren PhD 《Lancet》2009,374(9690):654-661
People with severe mental disorders are a neglected and vulnerable group in complex emergencies. Here, we describe field experiences in establishing mental health services in five humanitarian settings. We show data to quantify the issue, and suggest reasons for this neglect. We then outline the actions needed to establish services in these settings, including the provision of practical training, medication, psychosocial supports, and, when appropriate, work with traditional healers. We have identified some persisting problems locally, nationally, and internationally, and suggest some solutions. Protection and care of people with severe mental disorders in complex emergencies is a humanitarian responsibility. 相似文献