全文获取类型
收费全文 | 288452篇 |
免费 | 9641篇 |
国内免费 | 435篇 |
专业分类
耳鼻咽喉 | 2382篇 |
儿科学 | 9489篇 |
妇产科学 | 4812篇 |
基础医学 | 32280篇 |
口腔科学 | 4056篇 |
临床医学 | 23845篇 |
内科学 | 55229篇 |
皮肤病学 | 2718篇 |
神经病学 | 28534篇 |
特种医学 | 13364篇 |
外国民族医学 | 6篇 |
外科学 | 44829篇 |
综合类 | 3732篇 |
一般理论 | 87篇 |
预防医学 | 26995篇 |
眼科学 | 4833篇 |
药学 | 17010篇 |
中国医学 | 745篇 |
肿瘤学 | 23582篇 |
出版年
2023年 | 658篇 |
2022年 | 1214篇 |
2021年 | 2474篇 |
2020年 | 1499篇 |
2019年 | 2295篇 |
2018年 | 24301篇 |
2017年 | 19126篇 |
2016年 | 21502篇 |
2015年 | 3646篇 |
2014年 | 4487篇 |
2013年 | 5643篇 |
2012年 | 14522篇 |
2011年 | 28364篇 |
2010年 | 22978篇 |
2009年 | 15420篇 |
2008年 | 26030篇 |
2007年 | 28755篇 |
2006年 | 7486篇 |
2005年 | 9011篇 |
2004年 | 9807篇 |
2003年 | 10004篇 |
2002年 | 8117篇 |
2001年 | 2215篇 |
2000年 | 2263篇 |
1999年 | 1901篇 |
1998年 | 1580篇 |
1997年 | 1318篇 |
1996年 | 988篇 |
1995年 | 1004篇 |
1994年 | 869篇 |
1993年 | 784篇 |
1992年 | 1262篇 |
1991年 | 1203篇 |
1990年 | 1174篇 |
1989年 | 1099篇 |
1988年 | 955篇 |
1987年 | 887篇 |
1986年 | 911篇 |
1985年 | 914篇 |
1984年 | 771篇 |
1983年 | 679篇 |
1982年 | 665篇 |
1981年 | 551篇 |
1980年 | 522篇 |
1979年 | 546篇 |
1978年 | 466篇 |
1977年 | 402篇 |
1975年 | 368篇 |
1974年 | 408篇 |
1973年 | 366篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
104.
Nail plate and nail unit abnormalities may be helpful as diagnostic tools or as a part of the puzzle for confirmation of systemic disease. There are specific and nonspecific nail signs, which can be seen involving one or more nails, that occur simultaneously or secondary to systemic disease. Occasionally these clues can be diagnostic, while most are nonspecific reaction patterns. Nail changes occur in the nail plate as a result of nail matrix abnormalities caused by systemic disease and other systemic insults such as reactions to medications. In this article we review some of the more common nail signs that can be used to help diagnose systemic disease. 相似文献
105.
Depression in Alzheimer's disease: is there a temporal relationship between the onset of depression and the onset of dementia? 总被引:4,自引:0,他引:4
Alzheimer's disease (AD) patients often present with concurrent major depression (MD). To investigate the reasons for this comorbidity, e.g. MD being a risk factor for AD, or both diagnoses having a common neurobiology, the temporal relationship between the first onset of AD and of MD during lifetime was investigated-57 out of 146 AD patients had a lifetime diagnosis of MD. The correlation between the ages at onset of MD and dementia was calculated. The incidence of MD in AD patients in several 5-year-intervals before and after the onset of AD was compared with the average incidence of MD in the present AD sample and with the expected incidence of MD in the general population. No significant correlation between the onset of AD and of MD could be found after controlling for age, gender and the Mini-Mental-State. However, the incidence of MD 5 years before and after the onset of AD significantly exceeded the expected incidences-MD is only partially related to AD. However, the increased incidence of MD within 5 years before and after the onset of dementia may indicate that a common neurobiological process causes cognitive decline and depression in a subsample of AD patients. 相似文献
106.
107.
108.
109.
Computer competition analysis of 3H-DHA (3H-dihydroalprenolol, a nonselective beta-adrenergic radioligand) binding in the presence of unlabeled metoprolol (a beta 1-selective antagonist) indicates the existence of both beta 1- and beta 2-adrenergic receptor subtypes in the rat placenta and confirms previous reports that both beta-adrenoceptors are present in adult rat cortex. In the fetal brain (20th day of gestation), however, only beta 1-receptors were detected. Pregnant rats were chronically exposed to methadone from day 7 to day 20 of gestation via implanted osmotic minipumps (6.3-9.0 mg/kg/day). This treatment schedule did not induce a change in the affinity and density of either beta-receptor subtype in the placental, fetal and maternal brain homogenates. The results are discussed in terms of the reported monoaminergic and opiate receptor functional interactions. 相似文献
110.