全文获取类型
收费全文 | 1991篇 |
免费 | 204篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 106篇 |
妇产科学 | 22篇 |
基础医学 | 271篇 |
口腔科学 | 45篇 |
临床医学 | 232篇 |
内科学 | 308篇 |
皮肤病学 | 50篇 |
神经病学 | 172篇 |
特种医学 | 233篇 |
外科学 | 239篇 |
综合类 | 73篇 |
一般理论 | 2篇 |
预防医学 | 187篇 |
眼科学 | 57篇 |
药学 | 97篇 |
中国医学 | 1篇 |
肿瘤学 | 93篇 |
出版年
2022年 | 9篇 |
2021年 | 19篇 |
2020年 | 20篇 |
2019年 | 23篇 |
2018年 | 34篇 |
2017年 | 18篇 |
2016年 | 39篇 |
2015年 | 43篇 |
2014年 | 48篇 |
2013年 | 77篇 |
2012年 | 80篇 |
2011年 | 49篇 |
2010年 | 76篇 |
2009年 | 70篇 |
2008年 | 69篇 |
2007年 | 90篇 |
2006年 | 85篇 |
2005年 | 74篇 |
2004年 | 76篇 |
2003年 | 68篇 |
2002年 | 60篇 |
2001年 | 52篇 |
2000年 | 37篇 |
1999年 | 50篇 |
1998年 | 59篇 |
1997年 | 59篇 |
1996年 | 63篇 |
1995年 | 60篇 |
1994年 | 40篇 |
1993年 | 41篇 |
1992年 | 43篇 |
1991年 | 39篇 |
1990年 | 28篇 |
1989年 | 42篇 |
1988年 | 46篇 |
1987年 | 35篇 |
1986年 | 50篇 |
1985年 | 39篇 |
1984年 | 33篇 |
1983年 | 37篇 |
1982年 | 18篇 |
1981年 | 30篇 |
1980年 | 16篇 |
1979年 | 12篇 |
1978年 | 18篇 |
1977年 | 18篇 |
1976年 | 19篇 |
1974年 | 15篇 |
1973年 | 11篇 |
1972年 | 9篇 |
排序方式: 共有2203条查询结果,搜索用时 15 毫秒
101.
102.
103.
AC Winter K Berger JE Buring & T Kurth 《Cephalalgia : an international journal of headache》2009,29(2):269-278
We evaluated the association of body mass index (BMI) with migraine and migraine specifics in a cross-sectional study of 63 467 women aged ≥ 45 years, of whom 12 613 (19.9%) reported any history of migraine and 9195 had active migraine. Compared with women without migraine and a BMI < 23 kg/m2 , women with a BMI ≥ 35 kg/m2 had adjusted odds ratios (ORs) (95% confidence intervals) of 1.03 (0.95, 1.12) for any history of migraine. Findings were similar for active migraineurs. Women with a BMI of ≥ 35 kg/m2 had increased risk for low and high migraine frequency, with the highest estimate for women who reported daily migraine. Compared with women with the lowest associated risk (migraine frequency < 6 times/year; BMI between 27.0 and 29.9 kg/m2 ), women with a BMI ≥ 35 kg/m2 had an OR of daily migraine of 3.11 (1.12, 8.67). Among the women with active migraine, a BMI ≥ 35 kg/m2 was associated with increased risk of phonophobia and photophobia and decreased risk of a unilateral pain characteristic and migraine aura. Our data confirm previous findings that the association between BMI with migraine is limited to migraine frequency and specific migraine features. 相似文献
104.
105.
Yonghoon Rim Ph.D. Ahnryul Choi Ph.D. Susan T. Laing M.D. David D. McPherson M.D. Hyunggun Kim Ph.D 《Echocardiography (Mount Kisco, N.Y.)》2014,31(10):E300-E303
Clinical long‐term outcomes have shown that partial leaflet resection followed by ring annuloplasty is a reliable and reproducible surgical repair technique for treatment of mitral valve (MV) leaflet prolapse. We report a 61‐year‐old male for three‐dimensional transesophageal echocardiography (3DTEE)‐based virtual posterior leaflet resection and ring annuloplasty. Severe mitral regurgitation was found and computational evaluation demonstrated substantial leaflet malcoaptation and high stress concentration. Following virtual resection and ring annuloplasty, posterior leaflet prolapse markedly decreased, sufficient leaflet coaptation was restored, and high stress concentration disappeared. Virtual MV repair strategies using 3DTEE have the potential to help optimize MV repair. 相似文献
106.
107.
Accurate pregnancy dating is vital to obstetric management. However, first trimester fetal charts commonly used in Australia rely on data reported more than three decades ago. This study reports first trimester dating and growth charts for crown‐rump length between 5 and 14 weeks of gestation and biparietal diameter between 9 and 14 weeks of gestation on an Australia population using modern real‐time ultrasound equipment. All consenting eligible women attending a large Sydney clinic for first trimester ultrasound between March 2005 and December 2006 were recruited. Measurements were carried out to Australasian Society for Ultrasound in Medicine standard protocols. Statistical analyses were undertaken using polynomial regression models and thorough diagnostic checks made. Overall 396 eligible women consented to the study, with 268 between 9 and 14 weeks of gestation. The average participant age was 34 years (range 22–45 years), 371 and all yielded valid biometry measurements. Equations, means and 90% reference intervals for crown‐rump length measurements and biparietal diameter measurements were derived using polynomial regression models. Thorough residual and diagnostic checks were made. Once validated by others, we believe they will warrant consideration for use by Australasian Society for Ultrasound in Medicine. 相似文献
108.
Influenza virus infection in the second and third trimesters of pregnancy: a clinical and seroepidemiological study 总被引:1,自引:0,他引:1
109.
AM Boot J Nauta AC Hokken-Koelega HA Pols MA de Ridder SM de Muinck Keizer-Schrama 《Archives of disease in childhood》1995,72(6):502-506
A cross sectional study assessed the bone mineral density (BMD) of 20 young adult patients who received a renal transplantation in childhood. The BMD of the lumbar spine, mainly trabecular bone, and of the total body, mainly cortical bone, were measured and expressed as an SD score. Fourteen patients (70%) had a BMD SD score of the lumbar spine below -1, of whom six patients were below -2. Fifteen patients (75%) had a BMD SD score of the total body below -1, of whom seven patients were below -2, Both trabecular and cortical bone appeared to be involved in the osteopenic process. The cumulative dose of prednisone was inversely correlated to both lumbar spine and total body BMD SD score. In a multiple regression analysis the cumulative dose of prednisone appeared to be the only factor with a significant effect on BMD SD score. Most young adult patients who had received a renal transplantation in childhood had moderate to severe osteopenia. Corticosteroid treatment played a major part in the development of osteopenia in these patients. 相似文献
110.
Prevention of subglottic stenosis in neonatal ventilation 总被引:1,自引:0,他引:1
I A Laing D L Cowan G M Ballantine R Hume 《International journal of pediatric otorhinolaryngology》1986,11(1):61-66
Mechanical ventilation of the newborn is now widely used in neonatal intensive care. The oro-tracheal route of intubation is simpler, but for long-term ventilation has been considered unstable. A method of fixation of oro-tracheal tubes is described which overcomes this instability. Five hundred consecutive ventilated infants were intubated by the oro-tracheal route and the tube was fixed by the method described. Of the 500 ventilated infants, 213 died without being extubated. Of the 287 survivors, 44 developed a degree of post-extubation stridor. No surviving infant developed clinical evidence of subglottic stenosis and in almost 200 postmortem examinations laryngeal narrowing was not identified. The method of oro-tracheal fixation described is stable and may reduce the incidence of subglottic stenosis. 相似文献