全文获取类型
收费全文 | 60942篇 |
免费 | 5116篇 |
国内免费 | 2521篇 |
专业分类
耳鼻咽喉 | 930篇 |
儿科学 | 1537篇 |
妇产科学 | 515篇 |
基础医学 | 7820篇 |
口腔科学 | 7480篇 |
临床医学 | 5495篇 |
内科学 | 6770篇 |
皮肤病学 | 485篇 |
神经病学 | 1827篇 |
特种医学 | 3212篇 |
外国民族医学 | 28篇 |
外科学 | 13444篇 |
综合类 | 8379篇 |
现状与发展 | 7篇 |
一般理论 | 1篇 |
预防医学 | 1703篇 |
眼科学 | 284篇 |
药学 | 2564篇 |
40篇 | |
中国医学 | 1523篇 |
肿瘤学 | 4535篇 |
出版年
2024年 | 122篇 |
2023年 | 922篇 |
2022年 | 1660篇 |
2021年 | 2360篇 |
2020年 | 2321篇 |
2019年 | 2121篇 |
2018年 | 2049篇 |
2017年 | 2058篇 |
2016年 | 2108篇 |
2015年 | 2245篇 |
2014年 | 3723篇 |
2013年 | 4802篇 |
2012年 | 3018篇 |
2011年 | 3554篇 |
2010年 | 3143篇 |
2009年 | 3039篇 |
2008年 | 2954篇 |
2007年 | 3033篇 |
2006年 | 2805篇 |
2005年 | 2661篇 |
2004年 | 2343篇 |
2003年 | 2013篇 |
2002年 | 1670篇 |
2001年 | 1442篇 |
2000年 | 1170篇 |
1999年 | 1043篇 |
1998年 | 885篇 |
1997年 | 880篇 |
1996年 | 843篇 |
1995年 | 620篇 |
1994年 | 629篇 |
1993年 | 457篇 |
1992年 | 469篇 |
1991年 | 418篇 |
1990年 | 335篇 |
1989年 | 303篇 |
1988年 | 270篇 |
1987年 | 221篇 |
1986年 | 200篇 |
1985年 | 269篇 |
1984年 | 203篇 |
1983年 | 156篇 |
1982年 | 178篇 |
1981年 | 149篇 |
1980年 | 138篇 |
1979年 | 137篇 |
1978年 | 134篇 |
1977年 | 103篇 |
1976年 | 81篇 |
1975年 | 42篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Kyung‐Sub Moon Shin Jung Jae‐Hyuk Lee Tae‐Young Jung In‐Young Kim Soo‐Han Kim Sam‐Suk Kang 《Neuropathology》2006,26(2):141-146
We present a case of benign osteoblastoma of the occipital bone. Benign osteoblastoma is an uncommon primary bone tumor, which usually involves the vertebrae and the long bones. This tumor rarely develops in the calvaria, showing a preference for the temporal and frontal bones when it does. To the best of our knowledge, this case is only the eighth reported case of benign osteoblastoma confined to the occipital bone. A 20‐year‐old male presented with a mild tender mass lesion of the occipital area, just below the lambda. Plain X‐ray films and CT scans demonstrated an osteolytic mass surrounded by the sclerotic rim within the diploic space. MRI proved to be effective for the evaluation of the intracranial and intraosseous extensions of the tumor. However, it was very difficult to formulate a differential diagnosis against other osteoblastic tumors, or osteoid osteoma, in view of its radiological appearance. The final diagnosis was obtained by careful consideration of the histopathological characteristics of the tumor combined with its clinical and radiological features. Although generally regarded as benign, a complete resection is preferred over conventional curettage as this can guard against possible recurrence and malignant transformation. 相似文献
72.
A. Sudanese A. Toni N. Baldini D. Tigani M. Campanacci 《International orthopaedics》1988,12(2):115-118
Summary Seven patients with eccentrically placed tumours of the distal end of the humerus treated with partial resection and autogenous iliac bone grafting are reported. The functional results are discussed.
Résumé Présentation de sept cas de tumeurs situées à l'extrémité distale de l'humérus et traitées par résection limitée et reconstruction par autogreffe lilaque. Discussion des résultats fonctionnels.相似文献
73.
74.
M. M. Giraud-Guille 《Calcified tissue international》1988,42(3):167-180
Summary Ultrathin sections of decalcified human compact bone, observed by transmission electron microscopy, reveal that collagen fibrils
can be distributed in the form of a superimposed series of nested arcs. This characteristic pattern has never been interpreted
in previous works on compact bone structure. We demonstrate, by goniometric observations at the ultrastructural level, that
such series of nested arcs are a consequence of the “twisted plywood” architecture of collagen fibrils in the compact bone
matrix. In the same specimens, an “orthogonal plywood” disposition of collagen fibrils is also observed; a transition exists
between these two types of orders. We show that the “twisted plywood structure” accounts well for certain optical properties
of osteons, observed in polarizing microscopy, described as “intermediate osteons.” The particular geometry of collagen fibrils,
leading to nested arcs in oblique sections, is analogous to the distribution of molecules in certain liquid crystals (called
cholesteric liquid crystals). The principle of a liquid crystalline self-assembly of the collagen matrix in bone is therefore
discussed. 相似文献
75.
Neurogenic muscle hypertrophy in radiculopathy 总被引:1,自引:0,他引:1
The course of radiculopathy is sometimes associated with weakness and wasting of muscles. Very rarely in such cases, however, is hypertrophy of muscle fibres observed. Three cases are presented of sciatica with enlarged calves caused by hypertrophy of type 1 or types 1 and 2 muscle fibres. In light of the literature and the results obtained, an attempt is made to explain the cause of rare clinical symptoms and draw attention to diagnostic and therapeutic difficulties. 相似文献
76.
Objective Report of two cases of exudative discoid and lichenoid dermatosis (Sulzberger-Garbe), with typical penile lesions. Differential diagnosis of persistent penile plaques. Background Following remission of the generalized eruption of exudative discoid and lichenoid dermatosis (Sulzberger-Garbe), it is not unusual to see a single remaining lesion localized on the penis. Since Sulzberger et al. (Sulzberger MB, Witten VH, Hunt JA. Puzzling persistent penile plaques. Arch Dermatol 1956:73:101-109) reviewed dermatoses presenting with puzzling persistent penile plaques in 1955, further dermatoses have evolved as important differential diagnoses. Much controversy has arisen as to the justification of exudative discoid and lichenoid dermatosis (Sulzberger-Garbe) as a disease entity. Conclusions Diagnosis of most cases of persistent plaques of dermatitis on the penis is possible with a careful examination of the entire skin, and a thorough history to discover past lesions. The possibility of malignancy makes a biopsy mandatory. Exudative discoid and lichenoid chronic dermatosis (Sulzberger-Garbe) typically responds well to systemic steroids. Intrale-sional triamcinolone acetonide has been demonstrated to be effective in the treatment of a persistent penile plaque in exudative discoid and lichenoid dermatosis (Sulzberger-Garbe), and may be helpful in discontinuing or reducing systemic therapy to a level compatible with long-term treatment. 相似文献
77.
78.
取32只2~3个月的BALB/C小白鼠,随机分为4组,每组8只,第1组为对照组,其余3个组为实验组,实验组小白鼠左腿皮下注射苯0.3ml(15ml/kg体重).注射后分别于24h,48h,72h脱颈处死。观察中毒前、后末梢血象、骨髓细胞、骨髓细胞构成的变化。结果表明,苯中毒时骨髓变化先于末梢血象的变化,骨髓的病变为造血细胞变性、坏死,大量毛细血管扩张、充血,骨髓细胞构成降低,而且骨髓细胞构成中细胞成分降低早于外周血粒细胞减少。 相似文献
79.
Nerve biopsy findings in Niemann-Pick type II (NPC) 总被引:1,自引:0,他引:1
A. F. Hahn J. J. Gilbert C. Kwarciak J. Gillett C. F. Bolton C. A. Rupar J. W. Callahan 《Acta neuropathologica》1994,87(2):149-154
The severe infantile form of Niemann-Pick disease type II was diagnosed in a 4-year-old girl and confirmed by demonstrating in cultured skin fibroblasts a deficiency of low-density lipoprotein-stimulated cholesterol ester synthesis of < 5% of normal. Electrodiagnostic studies revealed changes of a predominantly demyelinating motor and sensory polyneuropathy. Light microscope and ultrastructural examination of a peroneal nerve biopsy showed unique changes. Compacted myelin sheaths were disproportionately thin with marked globular irregularities in single teased nerve fibres and evidence of chronic demyelination. The majority of axons were preserved but axonal spheroids and cytoskeletal abnormalities akin to neuroaxonal dystrophy were noted. Membrane-bound multilobulated lysosomal inclusions of floccular and electron-dense material were present in Schwann cells (SC), endoneurial fibroblasts, macrophages, pericytes and endothelial cells. SC of myelinated fibres were stuffed with whorls of concentric osmiophilic membranous profiles and electron-lucent material. The findings are diagnostic and differ from those of classical Niemann-Pick disease. 相似文献
80.
Eberhard Henze Gerhard Graf Malte Clausen Bertram Rail Rolf Weller Dieter Derichs Joachim Kreidler Peter Heidenreich F. Sitzmann Willi Ernst Adam 《European journal of nuclear medicine and molecular imaging》1990,16(2):97-101
The exact regional correlation of findings of facial bone scans, planar or SPECT, to dental orthopan X-ray films (OPT) is difficult because of the very different projection techniques. To improve correlative imaging in this regard a projection algorithm was developed that uses SPECT data of the skull for reconstructing an orthopan tomoscintigraphic projection. Fourteen conventional SPECT slices of the upper and lower jaws were obtained during bone scanning. All mandibular slices were superimposed resulting in a horseshoe shaped structure, which was marked by an ROI which was divided into segments. All 14 SPECT slices were then masked by this segmental ROI, thereby marking the teeth-carrying bone in all slices. The information from this horseshoe like ROI is then transformed into lines. Line by line arrangement results in an orthopan projection, the orthopan tomoscintigram. This new display allows 1:1 true scale superimposition with the X-ray OPT and markedly facilitates correlative imaging. 相似文献