全文获取类型
收费全文 | 12821篇 |
免费 | 812篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 94篇 |
儿科学 | 347篇 |
妇产科学 | 339篇 |
基础医学 | 1946篇 |
口腔科学 | 211篇 |
临床医学 | 1318篇 |
内科学 | 2964篇 |
皮肤病学 | 181篇 |
神经病学 | 1181篇 |
特种医学 | 362篇 |
外科学 | 1455篇 |
综合类 | 135篇 |
一般理论 | 14篇 |
预防医学 | 1022篇 |
眼科学 | 249篇 |
药学 | 948篇 |
中国医学 | 8篇 |
肿瘤学 | 916篇 |
出版年
2023年 | 72篇 |
2022年 | 98篇 |
2021年 | 259篇 |
2020年 | 197篇 |
2019年 | 259篇 |
2018年 | 266篇 |
2017年 | 199篇 |
2016年 | 196篇 |
2015年 | 318篇 |
2014年 | 392篇 |
2013年 | 619篇 |
2012年 | 970篇 |
2011年 | 1000篇 |
2010年 | 518篇 |
2009年 | 461篇 |
2008年 | 829篇 |
2007年 | 918篇 |
2006年 | 894篇 |
2005年 | 855篇 |
2004年 | 834篇 |
2003年 | 785篇 |
2002年 | 764篇 |
2001年 | 124篇 |
2000年 | 102篇 |
1999年 | 152篇 |
1998年 | 152篇 |
1997年 | 135篇 |
1996年 | 116篇 |
1995年 | 122篇 |
1994年 | 85篇 |
1993年 | 86篇 |
1992年 | 78篇 |
1991年 | 84篇 |
1990年 | 60篇 |
1989年 | 52篇 |
1988年 | 48篇 |
1987年 | 43篇 |
1986年 | 45篇 |
1985年 | 39篇 |
1984年 | 43篇 |
1983年 | 28篇 |
1982年 | 60篇 |
1981年 | 30篇 |
1980年 | 27篇 |
1979年 | 35篇 |
1978年 | 26篇 |
1977年 | 34篇 |
1976年 | 15篇 |
1975年 | 26篇 |
1973年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
6.
Steven V Koenen Anjoke J M Huisjes Jules Dings Yolanda van der Graaf Gerard H A Visser Hein W Bruinse 《The journal of maternal-fetal & neonatal medicine》2006,19(2):93-99
OBJECTIVE: To determine if there is a diurnal pattern in the clinical symptoms of HELLP (Hemolysis, Elevated Liver enzymes, Low Platelets) syndrome. STUDY DESIGN: A retrospective study was performed in 134 pregnancies complicated by HELLP syndrome. The medical records were reviewed to describe each HELLP episode. Time of day was divided into three periods, day, evening, and night. The following parameters were categorized according to the time of day: onset of symptoms, consultation by the doctor, initial blood sampling, diagnosis and decrease of symptoms. Biochemical parameters at clinical presentation and consecutive changes within 24 h were recorded. RESULTS: In 65 pregnancies 77 HELLP episodes were well documented. Times of onset of symptoms and consultation by the doctor were significantly higher during the evening and night (p < 0.001), whereas times of diagnosis and decrease of symptoms occurred significantly more during the day (p < 0.001). In only 49.3% of the cases were diagnostic laboratory criteria met at clinical presentation. This was mainly due to platelet values in excess of 100 x 10(9)/l. Several hours later (median 8 h, range 2-23) the decrease in platelets occurred. CONCLUSIONS: A diurnal pattern exists in the clinical symptoms of HELLP syndrome that is characterized by an exacerbation during the night and recovery during the day. There is a considerable delay between the onset of symptoms and the fulfillment of diagnostic laboratory criteria. 相似文献
7.
8.
9.
Alessia Pascale Marialaura Amadio Stefano Govoni Fiorenzo Battaini 《Pharmacological research》2007,55(6):560-569
The brain represents the primary centre for the regulation and control of all our body activities, receiving and interpreting sensory impulses and transmitting information to the periphery. Most importantly, it is also the seat of consciousness, thought, emotion and especially memory, being in fact able to encode, store and recall any information. Memory is really what makes possible so many of our complex cognitive functions, including communication and learning, and surely without memory, life would lose all of its glamour and purpose. Age-associated mental impairment can range in severity from forgetfulness at the border with pathology to dementia, such as in Alzheimer's disease. In recent years, one of the most relevant observations of research on brain aging relates to data indicating that age-related cognitive decline is not only due to neuronal loss, as previously thought; instead, scientists now believe that age-associated functional changes have more to do with the dysfunctions occurring over time. Within this context a prominent role is certainly played by signal transduction cascades which guarantee neuronal cell to elaborate coordinated responses to the multiple signals coming from the outside and to adapt itself to the environmental changes and requests. This review will focus the attention on protein kinase C pathway, with a particular interest on its activation process, and on the role of protein-lipid and protein-protein interactions to selectively localize the cellular responses. Furthermore, information is emerging and will be discussed on the possibility of mRNA stabilization through PKC activation. This review will also approach the issue on how alterations of these molecular cascades may have implications in physiological and pathological brain aging, such as Alzheimer's disease. 相似文献
10.
Pascale Jolliet Stéphane Nion Gwena?lle Allain-Veyrac L Tilloy-Fenart Dorothée Vanuxeem Vincent Berezowski Roméo Cecchelli 《Pharmacological research》2007,56(1):11-17
PURPOSE: The objective of the current study was to determine the ability of some antiemetic compounds to cross the blood-brain barrier (BBB) and thereby to determine possible side effects of compounds for the central nervous system (CNS). METHODS: We compared the brain penetration of some antiemetic compounds using an in vitro BBB model consisting in brain capillary endothelial cells co-cultured with primary rat glial cells. RESULTS: This study clearly demonstrated that the metopimazine metabolite, metopimazine acid, has a very low brain penetration, lower than metopimazine and even less than the other antiemetic compounds tested in this study. CONCLUSIONS: The poor brain penetration of metopimazine acid, metopimazine biodisponible form, seems very likely related to the clinically observed difference in therapeutic and safety profile. 相似文献