全文获取类型
收费全文 | 2774163篇 |
免费 | 191614篇 |
国内免费 | 7610篇 |
专业分类
耳鼻咽喉 | 35645篇 |
儿科学 | 92249篇 |
妇产科学 | 74986篇 |
基础医学 | 384125篇 |
口腔科学 | 71859篇 |
临床医学 | 248192篇 |
内科学 | 549410篇 |
皮肤病学 | 63438篇 |
神经病学 | 230944篇 |
特种医学 | 109144篇 |
外国民族医学 | 742篇 |
外科学 | 418115篇 |
综合类 | 53159篇 |
现状与发展 | 5篇 |
一般理论 | 997篇 |
预防医学 | 214088篇 |
眼科学 | 60126篇 |
药学 | 198782篇 |
8篇 | |
中国医学 | 5993篇 |
肿瘤学 | 161380篇 |
出版年
2021年 | 20258篇 |
2019年 | 20931篇 |
2018年 | 49731篇 |
2017年 | 38817篇 |
2016年 | 45187篇 |
2015年 | 30770篇 |
2014年 | 41651篇 |
2013年 | 61990篇 |
2012年 | 87787篇 |
2011年 | 105131篇 |
2010年 | 68804篇 |
2009年 | 60615篇 |
2008年 | 98901篇 |
2007年 | 106747篇 |
2006年 | 87588篇 |
2005年 | 85678篇 |
2004年 | 84140篇 |
2003年 | 82692篇 |
2002年 | 77917篇 |
2001年 | 128973篇 |
2000年 | 132089篇 |
1999年 | 110911篇 |
1998年 | 31814篇 |
1997年 | 28499篇 |
1996年 | 28593篇 |
1995年 | 27762篇 |
1994年 | 25480篇 |
1993年 | 23772篇 |
1992年 | 85421篇 |
1991年 | 81886篇 |
1990年 | 79078篇 |
1989年 | 76284篇 |
1988年 | 69676篇 |
1987年 | 68189篇 |
1986年 | 63751篇 |
1985年 | 60744篇 |
1984年 | 45216篇 |
1983年 | 38195篇 |
1982年 | 22809篇 |
1981年 | 20227篇 |
1979年 | 39182篇 |
1978年 | 27658篇 |
1977年 | 23422篇 |
1976年 | 21649篇 |
1975年 | 22922篇 |
1974年 | 26918篇 |
1973年 | 25454篇 |
1972年 | 23818篇 |
1971年 | 22003篇 |
1970年 | 20259篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Pradeep Balasubramanian M.D. C. R. Srinivas M.D. Pavai Arunachalam M.S. M.Ch. K. S. Thirumurthy M.S. M.Ch. P. R. Rajkumar M.S. M.Ch. H. Manuvidhya M.B.B.S. 《Pediatric dermatology》2015,32(3):e78-e81
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique. 相似文献
72.
Loss‐of‐function mutations in the gene encoding filaggrin underlie a Japanese family with food‐dependent exercise‐induced anaphylaxis 下载免费PDF全文
73.
Seyed Mehdi BagheriMofidi Majid Pouladian Seyed Behnamedin Jameie Ali Abbaspour Tehrani-Fard 《Australasian physical & engineering sciences in medicine / supported by the Australasian College of Physical Scientists in Medicine and the Australasian Association of Physical Sciences in Medicine》2016,39(3):717-726
Magnetic field generated by neuronal activity could alter magnetic resonance imaging (MRI) signals but detection of such signal is under debate. Previous researches proposed that magnitude signal change is below current detectable level, but phase signal change (PSC) may be measurable with current MRI systems. Optimal imaging parameters like echo time, voxel size and external field direction, could increase the probability of detection of this small signal change. We simulate a voxel of cortical column to determine effect of such parameters on PSC signal. We extended a laminar network model for somatosensory cortex to find neuronal current in each segment of pyramidal neurons (PN). 60,000 PNs of simulated network were positioned randomly in a voxel. Biot–savart law applied to calculate neuronal magnetic field and additional phase. The procedure repeated for eleven neuronal arrangements in the voxel. PSC signal variation with the echo time and voxel size was assessed. The simulated results show that PSC signal increases with echo time, especially 100/80 ms after stimulus for gradient echo/spin echo sequence. It can be up to 0.1 mrad for echo time = 175 ms and voxel size = 1.48 × 1.48 × 2.18 mm3. With echo time less than 25 ms after stimulus, it was just acquired effects of physiological noise on PSC signal. The absolute value of the signal increased with decrease of voxel size, but its components had complex variation. External field orthogonal to local surface of cortex maximizes the signal. Expected PSC signal for tactile detection in the somatosensory cortex increase with echo time and have no oscillation. 相似文献
74.
75.
76.
Monique G. Kumar M.Phil. M.D. Heather Ciliberto M.D. Susan J. Bayliss M.D. 《Pediatric dermatology》2015,32(2):198-200
Pediatric trachyonychia is an acquired nail disease that can cause distress to families. It is a poorly understood disease, and long‐term follow‐up data are lacking. We present an institutional review of 11 children with isolated pediatric trachyonychia followed over time. Children with the diagnosis of pediatric trachyonychia were identified and invited to participate. Pictures were taken on follow‐up and a questionnaire was answered. Exclusion criteria include having another diagnosis at the initial visit that causes nail dystrophy. Eleven patients with the diagnosis of pediatric trachyonychia were available for follow‐up. The mean age of appearance was 2.7 years (range 2–7 yrs) and the average follow‐up was 66 months (range 10–126 mos). Nine patients were treated with potent topical corticosteroids, one used only petrolatum, and one took vitamin supplements. One patient was found to have an additional skin and hair diagnosis of alopecia areata on follow‐up. On follow‐up, 82% noted improvement of the nails, whereas 18% noted no change. A majority of cases of pediatric trachyonychia are isolated and improve with time, regardless of treatment. 相似文献
77.
Wojciech Szychta M.D. Ph.D. Gheorghe Cerin M.D. Ph.D. F.E.S.C. Bogdan Adrian Popa M.D. Armienti Felice M.D. Guido Lanzillo M.D. Ph.D. Marco Diena M.D. Grzegorz Opolski M.D. Ph.D. F.E.S.C. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(6):1040-1043
Sinus venosus atrial septal defect (SV‐ASD) usually coexists with partial anomalous pulmonary vein connection (PAPVC). It is a difficult diagnosis in transthoracic echocardiography (TTE) due to eccentric position of defects. We present a rare case of atypical anatomical variation in PAPVC, which was never described before. Two right pulmonary veins drained into superior vena cava, which overrode SV‐ASD and interatrial septum, a third pulmonary vein into the right atrium. Complete diagnosis could not be set after TTE, nor transesophageal echocardiography, whereas angio‐CT was finally conclusive. This diagnostic approach allowed the surgical planning. 相似文献
78.
79.
80.