全文获取类型
收费全文 | 314553篇 |
免费 | 7987篇 |
国内免费 | 160篇 |
专业分类
耳鼻咽喉 | 3353篇 |
儿科学 | 11340篇 |
妇产科学 | 6267篇 |
基础医学 | 37482篇 |
口腔科学 | 6155篇 |
临床医学 | 24363篇 |
内科学 | 56310篇 |
皮肤病学 | 4643篇 |
神经病学 | 30603篇 |
特种医学 | 14547篇 |
外科学 | 49880篇 |
综合类 | 2950篇 |
一般理论 | 41篇 |
预防医学 | 25779篇 |
眼科学 | 5737篇 |
药学 | 18963篇 |
中国医学 | 825篇 |
肿瘤学 | 23462篇 |
出版年
2023年 | 832篇 |
2022年 | 565篇 |
2021年 | 1380篇 |
2020年 | 1284篇 |
2019年 | 1551篇 |
2018年 | 24562篇 |
2017年 | 19568篇 |
2016年 | 22447篇 |
2015年 | 3848篇 |
2014年 | 4097篇 |
2013年 | 6526篇 |
2012年 | 14083篇 |
2011年 | 28638篇 |
2010年 | 23206篇 |
2009年 | 14628篇 |
2008年 | 27246篇 |
2007年 | 29787篇 |
2006年 | 8969篇 |
2005年 | 10449篇 |
2004年 | 11130篇 |
2003年 | 12044篇 |
2002年 | 10090篇 |
2001年 | 5607篇 |
2000年 | 7165篇 |
1999年 | 3988篇 |
1998年 | 1751篇 |
1997年 | 1479篇 |
1996年 | 1083篇 |
1995年 | 913篇 |
1994年 | 929篇 |
1993年 | 845篇 |
1992年 | 896篇 |
1991年 | 807篇 |
1990年 | 806篇 |
1989年 | 766篇 |
1988年 | 666篇 |
1987年 | 715篇 |
1986年 | 614篇 |
1985年 | 820篇 |
1984年 | 764篇 |
1983年 | 658篇 |
1982年 | 673篇 |
1981年 | 602篇 |
1980年 | 596篇 |
1979年 | 550篇 |
1978年 | 491篇 |
1977年 | 524篇 |
1976年 | 448篇 |
1975年 | 453篇 |
1974年 | 430篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Ohne Zusammenfassung 相似文献
42.
Hans-Peter Schlake Karl-Heinz Grotemeyer Ingolf Böttger Ingo Wilhelm Husstedt Günter Brune 《Neurosurgical review》1987,10(3):191-196
Migraine is considered to be a functional neurological disorder. In classical migraine (headache associated with prodromal visual field disturbances) and migraine accompagnée (headache associated with transient neurological symptoms), disturbances of cerebral blood flow and amine metabolism are thought to be pathogenetic factors. However, conventional methods of neuroimaging (CAT, NMR) usually do not yield any pathological findings in patients. Since 123I-iodoamphetamine (123I-IMP) crosses the intact blood brain barrier, 123I-IMP-SPECT is used for the assessment of cerebral perfusion in various neurological diseases, including functional disorders. 123I-IMP-SPECT was performed on 5 patients with classical migraine and 18 patients with migraine accompagnée. At the time of investigation, all patients were symptom-free. Cerebral blood flow was decreased in all patients with migraine accompagnée, and often corresponded to the site of headache as well as to the topography of transient neurological symptoms. This reduction was most obvious in a patient with persisting neurological symptoms. Most patients with classical migraine, however, did not show any alteration of cerebral perfusion. It appears that migraine--and in particular migraine accompagnée--is characterized by a permanent alteration not only of cerebral blood flow but also of neuronal activity. Migraine attacks may occur in connection with exacerbations of preexisting metabolic alterations. 相似文献
43.
Background
The telomeric region of mouse chromosome 12 has previously shown frequent allelic loss in murine lymphoma. The Bcl11b gene has been identified and suggested as a candidate tumor suppressor gene within this region. In this study, we aimed to elucidate whether Bcl11b is mutated in lymphomas with allelic loss, and whether the mutations we detected conferred any effect on cell proliferation and apoptosis. 相似文献44.
45.
46.
Abstract Surgical treatment of proximal humeral fractures still remains a challenge. This is primarily due to the fact that sufficient
implant fixation in humeral head fractures is often not achieved due to substantial bone tissue loss with increasing age.
In the last few years the locking plates and locking nails have been introduced into clinical practice with varying results.
The biomechanical studies have focused on locking plate osteosynthesis as well. The following paper focuses on bone quality,
biomechanical studies and biology of proper osteosynthesis and reviews the most recent literature. 相似文献
47.
48.
49.
50.
Tarek A. Amer Tarek F. Elwakil Mahmoud S. Elbasiouny 《European journal of plastic surgery》2007,30(2):67-73
Haemangiomas are the most common tumours of infancy. They typically proliferate then involute with considerable variation
as regards to their rates of proliferation and involution. Haemangioma of the nasal tip is a lesion of special characteristics.
During proliferation, it expands, contracts and deviates the nasal cartilages. Particularly, it regresses slowly and frequently
involutes incompletely. That is why excision of the lesion is frequently suggested. The present study was conducted to evaluate
open rhinoplasty after initial non-excision treatment modalities namely, intra-lesional corticosteroid injections and laser
treatment, as a protocol of treatment for nasal tip haemangiomas. Twelve patients with nasal tip haemangiomas were included
in the present study. Patients of both sexes, of different ages, with deep and mixed haemangiomas were studied. Disfigurement
was the constant presenting symptom. Initial non-excision treatment reported different responses as denoted by the regression
of the lesions’ size. Haemangiomas constantly extended between the medial crura of the alar cartilages as noted by the constant
widening of the columella pre-operatively and the obvious separation of the nasal cartilages intra-operatively. This separation
was constantly found to require approximation by sutures. The results of the present study concluded that whenever an early
presentation with nasal tip haemangioma could be established, initial non-excision treatment followed by open rhinoplasty
could be a useful protocol of treatment. Within the limitations of the present study, this protocol could achieve an early,
safe and effective treatment for nasal tip haemangiomas with provisionally acceptable cosmetic outcomes so far. 相似文献