全文获取类型
收费全文 | 2135篇 |
免费 | 140篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 52篇 |
妇产科学 | 42篇 |
基础医学 | 211篇 |
口腔科学 | 63篇 |
临床医学 | 264篇 |
内科学 | 344篇 |
皮肤病学 | 29篇 |
神经病学 | 199篇 |
特种医学 | 93篇 |
外科学 | 424篇 |
综合类 | 10篇 |
一般理论 | 2篇 |
预防医学 | 167篇 |
眼科学 | 37篇 |
药学 | 185篇 |
中国医学 | 3篇 |
肿瘤学 | 99篇 |
出版年
2023年 | 19篇 |
2022年 | 23篇 |
2021年 | 41篇 |
2020年 | 17篇 |
2019年 | 28篇 |
2018年 | 56篇 |
2017年 | 28篇 |
2016年 | 55篇 |
2015年 | 27篇 |
2014年 | 53篇 |
2013年 | 71篇 |
2012年 | 102篇 |
2011年 | 106篇 |
2010年 | 62篇 |
2009年 | 65篇 |
2008年 | 110篇 |
2007年 | 90篇 |
2006年 | 115篇 |
2005年 | 86篇 |
2004年 | 56篇 |
2003年 | 68篇 |
2002年 | 57篇 |
2001年 | 67篇 |
2000年 | 72篇 |
1999年 | 51篇 |
1998年 | 21篇 |
1997年 | 14篇 |
1992年 | 25篇 |
1991年 | 23篇 |
1990年 | 22篇 |
1989年 | 39篇 |
1988年 | 32篇 |
1987年 | 26篇 |
1986年 | 33篇 |
1985年 | 27篇 |
1983年 | 17篇 |
1982年 | 18篇 |
1979年 | 21篇 |
1978年 | 14篇 |
1976年 | 13篇 |
1975年 | 24篇 |
1974年 | 25篇 |
1973年 | 24篇 |
1972年 | 30篇 |
1971年 | 24篇 |
1970年 | 32篇 |
1969年 | 19篇 |
1968年 | 18篇 |
1967年 | 16篇 |
1966年 | 22篇 |
排序方式: 共有2277条查询结果,搜索用时 15 毫秒
1.
2.
3.
Yue Chen Deborah L Levy Summer Sheremata Philip S Holzman 《Neuropsychopharmacology》2004,55(8):834-841
BACKGROUND: Visual motion processing is compromised in schizophrenia, as shown in deficient velocity discrimination. Processing of motion signals comprises progressive stages along the geniculate-striate-extrastriate-cortex pathway. Based on neurophysiologic and brain lesion studies, a velocity discrimination deficit can implicate early-stage motion processing if it is contrast-dependent or late-stage motion processing if it is contrast-independent. METHODS: To determine which stage underlies the deficient velocity discrimination in schizophrenia, we examined the effects of visual contrast on velocity discrimination. We measured velocity discrimination thresholds in schizophrenia patients (n = 34) and normal control subjects (n = 17) at both low and high contrasts, using each subject's contrast detection threshold to equate contrast levels. RESULTS: Schizophrenia patients showed poor velocity discrimination that improved little with high contrast, whereas normal control subjects showed enhanced velocity discrimination with increased contrast. CONCLUSIONS: The finding that the velocity discrimination deficit in schizophrenia is independent of contrast modulation implicates the later, rather than the earlier, stages of motion processing, which is mediated in the extrastriate cortex. 相似文献
4.
M Kautzky P Schenk W Bigenzahn K Rappersberger K Konrad 《Laryngo- rhino- otologie》1989,68(11):602-606
Hyalinosis cutis et mucosae (HCM) is a rare autosomal recessive disease of unknown aetiology and pathogenesis. In the skin and mucous membranes there is characteristically a deposition of hyaline-like material in the papillary dermis, around the small blood vessels and around skin appendages. Besides the manifold skin lesions, the mucous membranes affected are found in the nasal and oral cavities, pharynx and larynx. The latter causes the most characteristic symptom, namely, hoarseness, from birth. The lesions of the vessel walls are the most significant histopathological alterations. Ultrastructurally, massive deposits of amorphous, hyaline-like material in the dermis, reduction in number and size of the collagen fibrils and, finally, thickening of the basal laminae could be observed. The findings suggest an abnormal production of noncollagenous proteins as well as the alteration of the lysosomal systems of fibroblasts, endothelial cells and pericytes in the pathogenesis of hyalinosis. 相似文献
5.
Angela Ohlemacher Rainer Schenk Hans Peter Weitzel Nikolai Tyutyulkov Maria Tasseva Klaus Müllen 《Macromolecular chemistry and physics.》1992,193(1):81-93
The energy gaps of poly(p-arylenevinylene)s with phenylene, naphthylene and anthrylene subunits are determined by extrapolating the UV/VIS spectroscopic data of the oligomers. The band structure of the three polymers was theoretically investigated. The topology-, geometry- and correlation-factors were determined upon which the energy spectra of this class of one-dimensional π-electron systems depend. 相似文献
6.
Transbronchial needle aspiration (TBNA) was performed as a diagnostic procedure in 91 consecutive patients ultimately proven to have bronchogenic carcinoma. Results of TBNA were compared, in the same patients, to the diagnostic yield of cytologic examination of sputum, endobronchial brushings and washings, and endobronchial/transbronchial biopsy. The diagnostic yield for sputum was 13 percent (10 of 75); brushings, 40 percent (34 of 84); washings, 29 percent (26 of 89); biopsy, 56 percent (42 of 75); and TBNA, 45 percent (41 of 91). Aspirates were positive in 35 percent of patients with adenocarcinoma, 41 percent with squamous cell carcinoma, 52 percent with large cell undifferentiated carcinoma, and 55 percent of patients with small cell carcinoma. Carinal aspirates were positive in 54 percent (6 of 11); paratracheal aspirates, 57 percent (13 of 23); parabronchial aspirates, 39 percent (11 of 28); endobronchial, 78 percent (7 of 9), and peripheral mass or solitary pulmonary nodule, 40 percent (17 of 42). The overall diagnostic yield for brushings, washings, and biopsy was 64 percent. The addition of TBNA increased the yield to 71 percent. Bronchogenic carcinoma was diagnosed solely by TBNA in six patients, all with extrabronchial or extratracheal lesions. We conclude that TBNA increases the diagnostic yield of bronchoscopy, particularly in patients with extratracheal and extrabronchial lesions. An equally important observation is that TBNA fails to contribute significantly to the diagnosis of cancer in patients with lesions readily accessible by conventional bronchoscopic techniques. Exceptions to this observation include occasional patients with necrotic endobronchial tumors, submucosal lesions, and rarely patients with peripheral lung nodules or masses. 相似文献
7.
Severe pulmonary hypertension reversed by antibiotics in a patient with Whipple's disease 总被引:2,自引:1,他引:1
下载免费PDF全文
![点击此处可从《Thorax》网站下载免费的PDF全文](/ch/ext_images/free.gif)
H. Riemer R. Hainz C. Stain G. Dekan M. Feldner-Busztin P. Schenk C. Muller K. Sertl O. C. Burghuber 《Thorax》1997,52(11):1014-1015
The case is described of a 58 year old man with systemic Whipple's disease with pericardial and pleural effusions and severe pulmonary hypertension. After three months of antibiotic treatment there was a complete resolution, not only of the symptoms known to be associated with Whipple's disease (diarrhoea, arthralgia, pericardial and pleural effusions), but also of pulmonary hypertension.
相似文献
相似文献
8.
E J Derksen J A Eykelhoff K E Schenk P Patka H J Haarman 《Acta orthopaedica Belgica》1992,58(3):297-300
Retrosternal dislocation of the clavicle is an uncommon injury which may affect the mediastinal structures in a life-threatening way. Therefore, computed tomography is mandatory. Manipulation in the acute situation is the treatment of choice. In case of failure or old dislocation, open reduction with stabilization of the joint is required. The literature on this subject has been reviewed and an additional two cases are reported. 相似文献
9.
Deoxycorticosterone acetate (DOCA) is an agent commonly used to induce hypertension in experimental animals. This form of hypertension is dependent on altered regulation of central pressor mechanisms including the brain renin-angiotensin system. Additionally, there are characteristic changes involving the cardiovascular system and baroreflex responses. This review will discuss aspects of the pathogenesis of DOCA hypertension and the effect of various antihypertensive agents on the development of this form of hypertension. 相似文献
10.