全文获取类型
收费全文 | 23807篇 |
免费 | 1357篇 |
国内免费 | 174篇 |
专业分类
耳鼻咽喉 | 273篇 |
儿科学 | 710篇 |
妇产科学 | 745篇 |
基础医学 | 2446篇 |
口腔科学 | 675篇 |
临床医学 | 2074篇 |
内科学 | 5029篇 |
皮肤病学 | 434篇 |
神经病学 | 1111篇 |
特种医学 | 843篇 |
外国民族医学 | 11篇 |
外科学 | 4392篇 |
综合类 | 412篇 |
现状与发展 | 2篇 |
一般理论 | 12篇 |
预防医学 | 1917篇 |
眼科学 | 658篇 |
药学 | 2042篇 |
中国医学 | 161篇 |
肿瘤学 | 1391篇 |
出版年
2024年 | 19篇 |
2023年 | 283篇 |
2022年 | 852篇 |
2021年 | 1274篇 |
2020年 | 689篇 |
2019年 | 893篇 |
2018年 | 1227篇 |
2017年 | 711篇 |
2016年 | 765篇 |
2015年 | 765篇 |
2014年 | 1166篇 |
2013年 | 1314篇 |
2012年 | 1961篇 |
2011年 | 2130篇 |
2010年 | 1192篇 |
2009年 | 858篇 |
2008年 | 1276篇 |
2007年 | 1280篇 |
2006年 | 1186篇 |
2005年 | 1079篇 |
2004年 | 973篇 |
2003年 | 879篇 |
2002年 | 822篇 |
2001年 | 167篇 |
2000年 | 124篇 |
1999年 | 121篇 |
1998年 | 105篇 |
1997年 | 101篇 |
1996年 | 96篇 |
1995年 | 81篇 |
1994年 | 75篇 |
1993年 | 64篇 |
1992年 | 56篇 |
1991年 | 62篇 |
1990年 | 63篇 |
1989年 | 55篇 |
1988年 | 56篇 |
1987年 | 48篇 |
1986年 | 40篇 |
1985年 | 45篇 |
1984年 | 46篇 |
1983年 | 38篇 |
1982年 | 39篇 |
1981年 | 28篇 |
1980年 | 31篇 |
1978年 | 17篇 |
1977年 | 19篇 |
1976年 | 17篇 |
1974年 | 17篇 |
1973年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
22.
23.
24.
Jaafar Mouhyi Lars Sennerby Jeanjacques Pireaux Nicolas Dourov Samir Nammour Jack Van Reck 《Clinical oral implants research》1998,9(3):185-194
The purpose of the present study was to analyse clinically failed and retrieved implants prior to and after cleaning by means of scanning electron microscopy (SEM) and X-ray induced photoelectron spectroscopy (XPS) as compared to unused controls. Six different chemical and physical techniques for cleaning of contaminated titanium implants were evaluated: 1) rinsing in absolute ethanol for 10 min, 2) cleaning in ultrasonic baths containing trichloroethylene (TRI) and absolute ethanol, 10 min in each solution, 3) abrasive cleaning for 30 s, 4) cleaning in supersaturated citric acid for 30 s, 5) cleaning with continuous CO2-laser in dry conditions at 5 W for 10 s, 6) cleaning with continuous CO2-laser in wet conditions (saline) at 5 W for 10 s. SEM of failed implants showed the presence of contaminants of varying sizes and XPS showed almost no titanium but high carbon signals. XPS of unused titanium implants showed lower levels of titanium as previously reported, probably due to contamination of carbon which increased with time in room air. Cleaning of used implants in citric acid followed by rinsing with deionized water for 5 min followed by cleaning in ultrasonic baths with TRI and absolute ethanol gave the best results with regard to macroscopical appearance and surface composition. However, as compared to the unused implants the results from an element composition point of view were still unsatisfactory. It is concluded that further development and testing of techniques for cleaning of organically contaminated titanium is needed. 相似文献
25.
S H Faro A R Turtz R A Koenigsberg F B Mohamed C Y Chen H Stein 《AJNR. American journal of neuroradiology》1997,18(8):1588
The MR imaging features of a paraganglioma of the cauda equina with associated spinal cord cysts are presented. MR imaging showed the tumor to be isointense with the spinal cord on all pulse sequences and to enhance homogeneously. The intramedullary cysts had increased signal intensity on proton density- and T2-weighted images, and involved the cervical and thoracic regions. 相似文献
26.
A. Rashid Choudhury Mohamed S. Al Amin Kamal A. Chaudhri Khalaf R. Al Moutaery 《Child's nervous system》1995,11(2):115-117
A 5-year-old girl presented with a 1-year history of a subcutaneous swelling in the right parietal region. There were no cerebral symptoms or signs. Plain X-ray of the skull showed a lytic bony lesion with sclerotic margin. Computed tomography showed a hypodense, osteolytic lesion with thinned and bulged inner and outer skull tables with intact continuity. There was no intracranial lesion. At operation, the mass was found to be pink and granular, and was totally enucleated. Histology revealed it to be a benign osteoblastoma. 相似文献
27.
Boron neutron capture therapy (BNCT) is a potentially valuable treatment of malignant brain gliomas. A primary requirement for successful BNCT is achieving high local concentration of boron drugs in tumors. Intratumoral injection of liposomes containing boron drug has potential to meet this requirement and could prove to be of significance for BNCT. The brain tissue reaction following the intracerebral injection of a boron drug, BSH, either in solution form or in liposomally encapsulated form, was studied in rats. On histological examination, no evidence of tissue reaction was found after injecting BSH solution, suggesting that high local concentration of BSH was well tolerated. Injection of liposomal BSH was characterized by phagocytic activity at the site of injection, which was regressing by 24 h. Neither group of animals exhibited any signs of abnormal behavior or neurologic deficit. Direct intracerebral injection of BSH liposomes as per-formed in this report could be regarded as tolerable. 相似文献
28.
Extrapontine and central pontine myelinolysis (EPM/CPM) are rare events in pediatric neurology but can have devastating consequences. They are most commonly associated with rapid correction of hyponatremia but have been reported in other situations as well. This condition is relatively more common in adult neurology, not surprisingly, as alcoholism and associated malnutrition are often predisposing conditions. There have been few case reports in children with regards to this. We describe a 4-year old who presented with focal neurological deficits in the setting of diabetic ketoacidosis and the ensuing underlying osmotic imbalances. The patient made a remarkable recovery with no deficits of note-cognitive or motor. To our knowledge this is the youngest case reported so far of EPM in a child with diabetic ketoacidosis. The history of the condition, early animal experiments, clinicopathologic correlates, previous case reports and other scenarios in which this unusual event can occur are discussed--though the exact pathogenesis of this condition still remains unclear. We hope to bring to the attention of clinicians caring for children in the acute care setting, the importance of gradual correction of serum osmolality to reduce morbidity and mortality. 相似文献
29.
François Béïque Mohamed Ali Scott MacKenzie Mark Hynes 《Journal canadien d'anesthésie》2007,54(2):158-159
30.