全文获取类型
收费全文 | 862287篇 |
免费 | 70576篇 |
国内免费 | 1839篇 |
专业分类
耳鼻咽喉 | 12799篇 |
儿科学 | 24632篇 |
妇产科学 | 25133篇 |
基础医学 | 124215篇 |
口腔科学 | 25489篇 |
临床医学 | 75317篇 |
内科学 | 164618篇 |
皮肤病学 | 16983篇 |
神经病学 | 70106篇 |
特种医学 | 35203篇 |
外国民族医学 | 171篇 |
外科学 | 136168篇 |
综合类 | 24603篇 |
现状与发展 | 2篇 |
一般理论 | 263篇 |
预防医学 | 66890篇 |
眼科学 | 20522篇 |
药学 | 64729篇 |
中国医学 | 1596篇 |
肿瘤学 | 45263篇 |
出版年
2018年 | 7337篇 |
2015年 | 7722篇 |
2014年 | 11115篇 |
2013年 | 16784篇 |
2012年 | 22726篇 |
2011年 | 23839篇 |
2010年 | 13871篇 |
2009年 | 13061篇 |
2008年 | 22575篇 |
2007年 | 24638篇 |
2006年 | 24508篇 |
2005年 | 24145篇 |
2004年 | 23716篇 |
2003年 | 22853篇 |
2002年 | 21937篇 |
2001年 | 35838篇 |
2000年 | 36490篇 |
1999年 | 30900篇 |
1998年 | 9221篇 |
1997年 | 8545篇 |
1996年 | 8476篇 |
1995年 | 8006篇 |
1994年 | 7723篇 |
1992年 | 26658篇 |
1991年 | 26100篇 |
1990年 | 25620篇 |
1989年 | 24679篇 |
1988年 | 23220篇 |
1987年 | 22884篇 |
1986年 | 21742篇 |
1985年 | 21102篇 |
1984年 | 16390篇 |
1983年 | 13998篇 |
1982年 | 8854篇 |
1981年 | 8202篇 |
1980年 | 7674篇 |
1979年 | 16738篇 |
1978年 | 12115篇 |
1977年 | 10181篇 |
1976年 | 9328篇 |
1975年 | 10147篇 |
1974年 | 12641篇 |
1973年 | 12136篇 |
1972年 | 11539篇 |
1971年 | 10686篇 |
1970年 | 10218篇 |
1969年 | 9909篇 |
1968年 | 8900篇 |
1967年 | 8230篇 |
1966年 | 7653篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
We studied the role of theophylline on outcome of status epilepticus (SE) in children. During a two-year-period, 16 of 114 episodes of SE occurred in children receiving theophylline. At the onset of SE, theophylline blood levels were elevated in 8 episodes, and were therapeutic or subtherapeutic in 8 episodes. In the 8 episodes of SE with elevated theophylline levels, one child died and three suffered permanent new neurologic deficits. In the 8 episodes of SE with normal or low theophylline levels, only one child had a transient deficit. The occurrence of death or disability in 4 of 8 episodes of SE with elevated theophylline was considerably higher than the 23% incidence of death or persistent CNS deficit in the overall series of 114 episodes of SE. We conclude that theophylline, at toxic levels, is a significant factor in increased morbidity. We suspect that the hypoxia from the respiratory disorder for which theophylline was used, and the reduced cerebral blood flow known to occur with theophylline led to a failure to compensate for the increased cerebral metabolic rate of SE, thus increasing the risk of a poor outcome. 相似文献
993.
W A Hoefnagels G J Vielvoye F A de Jonge W E Peetermans J H Wondergem R A Roos 《Clinical neurology and neurosurgery》1991,93(2):149-150
A 21-year-old woman is reported with aplastic anaemia, who presented with pain in the leg. Rapid loss of sciatic nerve function followed. MRI showed irregular streaks of low intensity in the muscles of the pelvic region. A diagnosis of sciatic neuritis as initial symptom of clostridial myonecrosis was made. 相似文献
994.
Using the unique resources of the Rochester Epidemiology Project for population-based studies, we identified 629 Olmsted County, Minn., residents who fulfilled the 1988 International Headache Society criteria for newly diagnosed migraine over a 3-year period. Over 6,400 patient records from several diagnostic rubrics were screened; a substantial proportion of cases had been 'signed-out' to diagnoses other than 'migraine headache'. Medical records were reviewed by two trained nurses who abstracted supporting data for two neurologists. The neurologists determined whether each case met eligibility requirements and assigned a headache diagnosis by consensus. The diagnostic criteria offered some flexibility and were adapted to retrospective record-based research. Most records contained enough information to effectively classify the headache, although information on the frequency and duration of attacks proved to be problematic. A validation re-abstraction of a 10% sample of cases was undertaken with acceptable reproducibility of symptoms and diagnosis. Our study shows that migraine headache can be studied retrospectively through existing detailed medical records. 相似文献
995.
An apparently innocuous complaint such as a numb chin may be associated with malignant disease, either as heralding symptom or as a manifestation of metastasis. A series of 15 patients with numbness of the chin is presented in which a malignancy was diagnosed prior to the numbness. The numbness diminished or disappeared in 66% of the patients following either systemic chemotherapy or radiotherapy. 相似文献
996.
The cause of Alzheimer's disease is unknown. Several factors have been proposed including head trauma. At present, the link between head injury and a subsequent neurodegenerative process is largely circumstantial, except in the case of dementia pugilistica (punch drunk syndrome) found in boxers. Recent studies have shown that the brains of boxers with this syndrome contain large numbers of 'diffuse' beta-protein immunoreactive plaques. We supposed that this plaque type might be associated with trauma induced Alzheimer-like degeneration. In order to test this hypothesis we have re-investigated a previously reported case of post-traumatic premature Alzheimer's disease. Immunocytochemistry using antibodies to amyloid beta-protein revealed large numbers of 'diffuse' non-Congophilic plaques with little or no neuritic component. A similar preponderance of this plaque type is present in the brains of boxers with dementia pugilistica. Our observations support the idea of a trauma induced Alzheimer-like degenerative process and indicate that such a condition is associated with a marked preponderance of 'diffuse' plaques. 相似文献
997.
998.
999.
W J Richtsmeier P Styczynski M E Johns 《The Annals of otology, rhinology, and laryngology》1987,96(5):569-572
Immunosuppression observed even in the earliest laryngeal cancers can be, in part, reversed with H2 histamine antagonists. In an effort to explain this, we tested whether histamine could evoke changes in endogenous antitumor lymphokine production using tonsil lymphocytes as test cells. We have observed that lymphocytes, treated in vitro with histamine, display a significant suppression of lymphokine production and mixed lymphocyte proliferation response following galactose oxidase treatment. Interferon gamma production was reduced to less than 2% of control value in the presence of histamine. In contrast, the lymphokine-activated killer cell activity induced by purified, natural interleukin-2 was not affected by similar concentrations of histamine. Histamine appears to exert its inhibitory effect by stimulating the production of a substance released by suppressor T cells. The suppressive effects observed could be reversed by concomitant or sequential treatment with cimetidine or ranitidine and not by H1 histamine antagonists, indicating that it occurs through an H2 histamine receptor. These experiments suggest that histamine may have a profound suppressive effect on the lymphocyte population studied. 相似文献
1000.