全文获取类型
收费全文 | 453篇 |
免费 | 23篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 14篇 |
妇产科学 | 1篇 |
基础医学 | 80篇 |
口腔科学 | 71篇 |
临床医学 | 19篇 |
内科学 | 44篇 |
皮肤病学 | 25篇 |
神经病学 | 10篇 |
特种医学 | 24篇 |
外科学 | 92篇 |
综合类 | 21篇 |
预防医学 | 14篇 |
眼科学 | 6篇 |
药学 | 12篇 |
肿瘤学 | 32篇 |
出版年
2023年 | 6篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 19篇 |
2019年 | 9篇 |
2018年 | 13篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 11篇 |
2013年 | 11篇 |
2012年 | 22篇 |
2011年 | 24篇 |
2010年 | 20篇 |
2009年 | 20篇 |
2008年 | 18篇 |
2007年 | 24篇 |
2006年 | 15篇 |
2005年 | 16篇 |
2004年 | 9篇 |
2003年 | 16篇 |
2002年 | 13篇 |
2001年 | 13篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 4篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1993年 | 3篇 |
1992年 | 11篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 15篇 |
1987年 | 10篇 |
1986年 | 24篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1970年 | 4篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1937年 | 1篇 |
排序方式: 共有479条查询结果,搜索用时 15 毫秒
41.
Thirteen children, ranging in age from 45 days to 2 years, had severe gastrointestinal illness with the features characteristic of neonatal necrotising enterocolitis. All 13 children had preceding gastroenteritis leading to hypovolaemia. Necrotising enterocolitis can occur in children beyond the neonatal age group and it may occur as a sequel to gastroenteritis. 相似文献
42.
Ferguson (1975) calculated that if 5 per cent of the estimated 20 million patients with hypertension in the USA had a secondary cause, the cost of their investigation would amount to $2 billion at 1975 prices. For the majority of patients a careful clinical appraisal together with simple biochemical screening tests and a baseline ECG and chest film are adequate before embarking on therapy. For those patients in whom there are clinical or other grounds to suspect a treatable secondary cause, a wide range of modern investigative techniques are available. Even if there are no clues to a secondary cause initially, the possibility of such a cause is occasionally suggested by failure of response to triple therapy with, for example, a thiazide, a beta blocker, and a vasodilator. Whether the hypertensives are being treated in general practice or in hospital, a careful initial assessment together with regular supervision is essential to allow the identification of those with potentially curable disease. 相似文献
43.
Phadke MA Gadgil B Bharucha KE Shrotri AN Sastry J Gupte NA Brookmeyer R Paranjape RS Bulakh PM Pisal H Suryavanshi N Shankar AV Propper L Joshi PL Bollinger RC 《The Journal of nutrition》2003,133(10):3153-3157
Access to safe breast-feeding alternatives for HIV-infected mothers and their infants in many settings is limited. We compared the rates of early postpartum hospitalization of infants born to HIV-infected mothers using different infant-feeding practices in a large government hospital in Pune, India. From March 1, 2000 to November 30, 2001, infants born to HIV-infected mothers were followed in a postpartum clinic. All mothers had received a standard short course of antenatal zidovudine. Infant-feeding practices were assessed within 3 d of delivery, prior to postpartum hospital discharge. Sixty-two of 148 mothers (42%) were breast-feeding their infants. Eighty-six of the mothers (58%) were providing replacement feeding, primarily diluted cow, goat or buffalo milk (top feeding). Twenty-one of the 148 participating infants (14.2%) born during the study period required hospitalization within the 1st 6 mo of life and 6 infants required repeat hospitalization. All hospitalized infants were receiving replacement feeding with a rate of 0.093 hospitalizations per 100 person-days (95% CI, 0.062 to 0.136). The reasons for hospitalization included acute gastroenteritis (48.1%), pneumonia (18.5%), septicemia (11.1%) and jaundice (11.1%). A high risk for early postpartum hospitalization was seen in replacement-fed infants born to HIV-infected mothers in Pune, India. In settings such as India, where access to safe replacement feeding is limited, interventions making exclusive breast-feeding safer for HIV-infected mothers and infants are needed. Such interventions would be valuable additions to the very effective national prevention programs that currently rely on the provision of short-course zidovudine and nevirapine. 相似文献
44.
The CT and magnetic resonance findings of neuropathic spinal arthropathy in a patient with long-standing complete post-traumatic paraplegia are reported. The arthropathy involved primarily the disk space between the 11th and 12th thoracic vertebrae. The CT changes included vertebral body sclerosis with foci of bone destruction, replacement of the disk space by a soft tissue mass containing bone fragments extending beyond the confines of the vertebral body margins, degenerative changes of the posterior joints, a partially calcified progressively enlarging paraspinal soft tissue mass, and calcification within the spinal canal. 相似文献
45.
46.
Evaluation of friction between edgewise stainless steel brackets and orthodontic wires of four alloys 总被引:2,自引:0,他引:2
S Kapila P V Angolkar M G Duncanson R S Nanda 《American journal of orthodontics and dentofacial orthopedics》1990,98(2):117-126
This investigation was designed to determine the effects of wire size and alloy on frictional force generated between bracket and wire during in vitro translatory displacement of bracket relative to wire. Stainless steel (SS), cobalt-chromium (Co-Cr), nickel-titanium (NiTi), and beta-titanium (beta-Ti) wires of several sizes were tested in narrow single (0.050-inch), medium twin (0.130-inch) and wide twin (0.180-inch) stainless steel brackets in both 0.018- and 0.022-inch slots. The wires were ligated into the brackets with elastomeric ligatures. Bracket movement along the wire was implemented by means of a mechanical testing instrument, and frictional forces were measured by a compression cell and recorded on an X-Y recorder. beta-Ti and NiTi wires generated greater amounts of frictional forces than SS or Co-Cr wires did for most wire sizes. Increase in wire size generally resulted in increased bracket-wire friction. The wire size-alloy interaction on the magnitude of bracket-wire friction was statistically significant (p less than 0.005). With most wire sizes and alloys, narrow single brackets were associated with lower amounts of friction than wider brackets were. The levels of frictional forces in 0.018-inch brackets ranged from 49 gm with 0.016-inch SS wires in narrow single brackets to 336 gm with 0.017 x 0.025-inch beta-Ti wires in wide twin brackets. Similarly for 0.022-inch brackets, frictional forces ranged from 40 gm with 0.018-inch SS wires in narrow single brackets to 222 gm with 0.019 x 0.025-inch NiTi wires in wide twin brackets. 相似文献
47.
48.
Carmody DP Moreno R Mars AE Seshadri K Lambert GH Lewis M 《Journal of autism and developmental disorders》2007,37(7):1381-1385
A functional magnetic resonance imaging (fMRI) study was performed on a 4-year-old girl with autism. While sedated, she listened
to three utterances (numbers, hello, her own first name) played through headphones. Based on analyses of the fMRI data, the
amount of total brain activation varied with the content of the utterance. The greatest volume of overall activation was in
response to numbers, followed by the word ‘hello’, with the least activation to her name. Frontal cortex activation was greatest
in response to her name, with less activation for numbers, and the least for the word ‘hello.’ These findings indicate that
fMRI can identify and quantify the brain regions that are activated in response to words in children with autism under sedation. 相似文献
49.
50.