全文获取类型
收费全文 | 18678篇 |
免费 | 878篇 |
国内免费 | 167篇 |
专业分类
耳鼻咽喉 | 129篇 |
儿科学 | 374篇 |
妇产科学 | 576篇 |
基础医学 | 2266篇 |
口腔科学 | 427篇 |
临床医学 | 1529篇 |
内科学 | 5483篇 |
皮肤病学 | 260篇 |
神经病学 | 1713篇 |
特种医学 | 731篇 |
外国民族医学 | 1篇 |
外科学 | 2628篇 |
综合类 | 51篇 |
一般理论 | 1篇 |
预防医学 | 671篇 |
眼科学 | 238篇 |
药学 | 978篇 |
中国医学 | 31篇 |
肿瘤学 | 1636篇 |
出版年
2024年 | 13篇 |
2023年 | 121篇 |
2022年 | 260篇 |
2021年 | 517篇 |
2020年 | 275篇 |
2019年 | 395篇 |
2018年 | 502篇 |
2017年 | 363篇 |
2016年 | 408篇 |
2015年 | 474篇 |
2014年 | 722篇 |
2013年 | 904篇 |
2012年 | 1344篇 |
2011年 | 1361篇 |
2010年 | 833篇 |
2009年 | 802篇 |
2008年 | 1359篇 |
2007年 | 1336篇 |
2006年 | 1284篇 |
2005年 | 1256篇 |
2004年 | 1131篇 |
2003年 | 983篇 |
2002年 | 894篇 |
2001年 | 132篇 |
2000年 | 115篇 |
1999年 | 139篇 |
1998年 | 190篇 |
1997年 | 146篇 |
1996年 | 168篇 |
1995年 | 114篇 |
1994年 | 112篇 |
1993年 | 118篇 |
1992年 | 107篇 |
1991年 | 85篇 |
1990年 | 73篇 |
1989年 | 60篇 |
1988年 | 50篇 |
1987年 | 41篇 |
1986年 | 45篇 |
1985年 | 45篇 |
1984年 | 50篇 |
1983年 | 37篇 |
1982年 | 45篇 |
1981年 | 45篇 |
1980年 | 36篇 |
1979年 | 30篇 |
1977年 | 13篇 |
1976年 | 15篇 |
1975年 | 13篇 |
1974年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
63.
64.
Macchi C Popolizio A Casamorata F Bicchi S Pieroni A Molino Lova R Miniati B Gulisano M Catini C Conti AA Gensini GF 《Italian journal of anatomy and embryology = Archivio italiano di anatomia ed embriologia》2002,107(2):93-97
Fifty-four subjects, aged between 20 and 35 years, divided into two subgroups, respectively 30 healthy subjects (17 males and 13 females) and 24 subjects with "gonalgia sine materia" (13 males and 11 females) underwent isokinetic exercise test in order to compare their dominant limb with the not dominant one as regard as the strength of extensor and flexor muscles of the knee. No statistically significant difference was found in any of the studied parameters in the comparison between the dominant limb and the not dominant one, both within the subgroup of healthy subjects and within the subgroup of subjects with "gonalgia sine materia". Authors conclude that psychological features may play a preeminent role in the genesis, as well as in the maintenance of "gonalgia sine materia", thus confirming previous data available in medical literature. 相似文献
65.
Matturri L Ottaviani G Lavezzi AM 《Virchows Archiv : an international journal of pathology》2005,447(1):74-80
Cigarette smoking is associated with an increased incidence of atherosclerotic diseases. The aim of this study was to examine the progression of the preatherosclerotic lesions previously observed by us in coronary arteries of fetuses of smoker mothers and in infants with smoker parents. We examined the coronary arteries of 34 infants, aged 1–36 months, and the histological and biological [c-fos, proliferating cell nuclear antigen (PCNA), and apoptosis] features of the early atherosclerotic lesions. In 17 infants (50%), at least one parent smoked, generally more than five cigarettes a day. In 18 cases (53%), we observed variable thickening of the coronary walls from preatherosclerotic lesions to juvenile atherosclerotic plaques, related to parental smoking habit. This morphological progression of the lesions was accompanied by a sequence of biological changes in the smooth muscle cells of the tunica media. We suggest that the oxidants present in the gas phase of the parental cigarette smoke pass through the endothelium and induce at first the c-fos gene activation and subsequently the PCNA positivity, that is, a proliferative process. 相似文献
66.
Verga L Concardi M Pilotto A Bellini O Pasotti M Repetto A Tavazzi L Arbustini E 《Virchows Archiv : an international journal of pathology》2003,443(5):664-671
Mutations of the LMNA gene encoding the lamin A and C nuclear envelope proteins cause an autosomal dominant form of dilated cardiomyopathy (DCM) with atrioventricular block (AVB). The aim of this study was to investigate ultrastructural nuclear membrane changes by conventional electron microscopy and protein expression by immuno-electron microscopy in the heart of patients with DCM and AVB due to LMNA gene mutations. Four immunohistochemical techniques were used: pre-embedding and post-embedding in Epon-Araldite resin and London Resin White (LRW), with and without silver enhancement. Parallel light microscopy immunohistochemistry studies were performed. Conventional electron microscopy showed a loss of integrity of the myocyte nuclei with blebs of the nuclear membrane, herniations and delamination of the nuclear lamina and nuclear pore clustering. Post-embedding LRW was the most informative technique for morphology and immuno-labelling. Immuno-labelling was almost absent in the nuclear envelope of patients with LMNA gene mutations, but intensely present in controls. The loss of labelling selectively affected myocyte nuclei; the endothelial cell nuclei were immunostained in patients and controls. Light immunohistochemistry confirmed the results. These findings confirm the hypothesis that LMNA gene defects are associated with a loss of protein expression in the selective compartment of non-cycling myocyte nuclei. 相似文献
67.
Carlo M. Crocem Monica Shander Joanne Martinis Lucienne Cicurel Gian G. D'ancona Hilary Koprowski 《European journal of immunology》1980,10(6):486-488
Loss of human chromosomes from mouse × human hybridomas is not random. Human chromosomes 14, 5 and 22 are preferentially retained, while chromosomes 2 and 1 are preferentially lost. Interestingly, human chromosome 14, which carries the genes for human immunoglobulin heavy chains, appears to be retained by almost all the hybrid clones and subclones. 相似文献
68.
Marta Zelazko Magda Carneiro-Sampaio Monica Cornejo De Luigi Diana Garcia De Olarte Oscar Porras Madrigal Renato Berrón Perez Agueda Cabello Marylin Valentin Rostan Ricardo U. Sorensen 《Journal of clinical immunology》1998,18(2):161-166
The Latin American Group for Primary Immunodeficiencies, formed in 1993, presently includes 12 countries. One goal was to study the frequency of primary immunodeficiencies in various regions of the American continent and to enhance knowledge about these diseases among primary-care physicians, as well as allergist–immunologists. Important for this purpose was the development of a registry of primary immunodeficiencies using a uniform questionnaire and computerized database. To date, eight countries have collected information on a total of 1428 patients. Predominantly antibody deficiencies were reported in 58% of patients, followed by cellular and antibody immunodeficiencies associated with other abnormalities in 18%, immunodeficiency syndromes associated with granulocyte dysfunction in 8%, phagocytic disorders in 9%, combined cellular and antibody immunodeficiencies in 5%, and complement deficiencies in 2% of patients. The information gathered from this initial analysis of data will serve to expand the patient database to more areas within participating countries and to new countries and to increase collaboration toward better diagnosis and treatment of these diseases. 相似文献
69.
Sclerosteosis: report of a case in a black African man 总被引:3,自引:0,他引:3
Paolo Tacconi Paola Ferrigno Luigi Cocco Antonino Carinas Giorgio Tamburini Paolo Bergonzi Marcello Giagheddu 《Clinical genetics》1998,53(6):497-501
Sclerosteosis is a rare genetic disorder of bone modelling, similar to, but distinct from, van Buchem disease; it has been described almost exclusively in Afrikaners of South Africa, a white population of Dutch ancestry. Isolated cases have been reported in a girl in Japan, a boy in Spain, and in multiracial families in Brazil and USA.
Here we report a case of sclerosteosis in a black man born in Senegal. He presented with the full features of the disease: tall stature; syndactyly; nail dysplasia; massive sclerosis of the long tubular bones, the ribs, the pelvis and the skull; multiple cranial nerve involvement: optic atrophy, facial palsy and trigeminal neuralgia. Radiologic examination, visual and brainstem auditory evoked potentials, computerized tomography and magnetic resonance imaging of the skull were performed. This seems to be the first case of the disease in a black African individual, with no known relationship with Dutch ancestry. 相似文献
Here we report a case of sclerosteosis in a black man born in Senegal. He presented with the full features of the disease: tall stature; syndactyly; nail dysplasia; massive sclerosis of the long tubular bones, the ribs, the pelvis and the skull; multiple cranial nerve involvement: optic atrophy, facial palsy and trigeminal neuralgia. Radiologic examination, visual and brainstem auditory evoked potentials, computerized tomography and magnetic resonance imaging of the skull were performed. This seems to be the first case of the disease in a black African individual, with no known relationship with Dutch ancestry. 相似文献
70.
Epidemiological and Environmental Investigations of Legionella pneumophila Infection in Cattle and Case Report of Fatal Pneumonia in a Calf 下载免费PDF全文
Massimo Fabbi Maddalena Castellani Pastoris Eugenio Scanziani Simone Magnino Luigi Di Matteo 《Journal of clinical microbiology》1998,36(7):1942-1947
A fatal pneumonia due to Legionella pneumophila was diagnosed in a young calf reared in a dairy herd located in northern Italy. Clinical symptoms consisted of watery diarrhea, hyperthermia, anorexia, and severe dyspnea. The pathological and histological findings were very similar to those observed in human legionellosis. Legionella pneumophila serogroup 1 (SG1) and SG10 were isolated from the calf’s lung, and L. pneumophila SG1 was isolated from the calf’s liver. L. pneumophila SG1 was also demonstrated in the lung tissue by immunofluorescence and immunohistochemical examinations. Nine of 10 L. pneumophila SG1 isolates belonged to the Olda subtype, and 1 belonged to the Camperdown subtype. A very low prevalence of antibodies to Legionella was detected in cows and calves reared in the same herd. Cultures of aqueous sediment of an old electric water heater which supplied hot water for the feeding of the calves yielded L. pneumophila SG1. Four of the colonies tested belonged to the Olda subtype. Ten clinical and four environmental isolates were examined for the presence of plasmids. Nine of them were also examined by pulsed-field gel electrophoresis assay, and the same patterns were found for L. pneumophila SG1 Olda strains isolated from the calf and from the electric heater. This is the first report of a documented case of a naturally occurring Legionella pneumonia in an animal. Cattle probably act as accidental hosts for legionellae, much the same as humans. 相似文献