全文获取类型
收费全文 | 3257篇 |
免费 | 134篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 129篇 |
儿科学 | 45篇 |
妇产科学 | 75篇 |
基础医学 | 459篇 |
口腔科学 | 33篇 |
临床医学 | 254篇 |
内科学 | 1045篇 |
皮肤病学 | 13篇 |
神经病学 | 239篇 |
特种医学 | 76篇 |
外科学 | 416篇 |
综合类 | 27篇 |
预防医学 | 132篇 |
眼科学 | 37篇 |
药学 | 264篇 |
中国医学 | 3篇 |
肿瘤学 | 155篇 |
出版年
2024年 | 3篇 |
2023年 | 24篇 |
2022年 | 156篇 |
2021年 | 304篇 |
2020年 | 65篇 |
2019年 | 94篇 |
2018年 | 126篇 |
2017年 | 70篇 |
2016年 | 94篇 |
2015年 | 103篇 |
2014年 | 114篇 |
2013年 | 171篇 |
2012年 | 232篇 |
2011年 | 244篇 |
2010年 | 122篇 |
2009年 | 89篇 |
2008年 | 184篇 |
2007年 | 220篇 |
2006年 | 223篇 |
2005年 | 193篇 |
2004年 | 180篇 |
2003年 | 160篇 |
2002年 | 117篇 |
2001年 | 13篇 |
2000年 | 16篇 |
1999年 | 6篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1994年 | 4篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 7篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 4篇 |
1972年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有3402条查询结果,搜索用时 15 毫秒
61.
62.
Melatonin stimulates the activity of protective antioxidative enzymes in myocardial cells of rats in the course of doxorubicin intoxication 总被引:1,自引:0,他引:1
Dziegiel P Murawska-Ciałowicz E Jethon Z Januszewska L Podhorska-Okołów M Surowiak P Zawadzki M Rabczyński J Zabel M 《Journal of pineal research》2003,35(3):183-187
The study aimed at determining the effect of melatonin on the activity of protective antioxidative enzymes in the heart and of lipid peroxidation products in the course of intoxication with doxorubicin (DOX). The rats were categorized into four groups, receiving: 0.9% NaCl i.p. (NaCl control); melatonin [20 mg/kg body weight (b.w.)] s.c. (control Mel); DOX (2.5 mg/kg b.w.) i.p.; melatonin plus DOX in doses as above. All the substances were administered once in a week for four consecutive weeks. Homogenates of heart tissue were examined for activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), levels of reduced glutathione (GSH) and of lipid peroxidation indices (MDA + 4-HDA). Administration of melatonin alone did not induce alterations in levels of MDA + 4-HDA, GSH, or in activity of GPx, SOD or CAT, as compared to the group receiving 0.9% NaCl. GSH levels decreased following DOX but remained at normal levels following DOX and melatonin. The level of MDA + 4-HDA increased following DOX, as compared with the control, a change prevented by the combination of DOX + melatonin. Activities of GPx, SOD and CAT were higher in groups receiving DOX and/or DOX plus melatonin than in control groups. Activity of CAT and the level of GSH in the group receiving DOX plus melatonin were significantly higher than in the group intoxicated with DOX alone. The obtained results demonstrate that, when given in parallel with DOX, melatonin protects cardiomyocytes from damaging effects of the cytostatic drug (reflected by the levels of MDA + 4-HDA). The protective effect resulted, in part from the augmented levels of GSH and from stimulation of CAT activity by melatonin in cardiomyocytes subjected to the action of DOX. 相似文献
63.
Szleszkowski Łukasz Kadej Marcin Ogórek Rafał Thannhäuser Agata Dobrowolski Michał A. Jurek Tomasz 《International journal of legal medicine》2022,136(6):1829-1840
International Journal of Legal Medicine - It is extremely rare for table salt to be used to preserve a dead body in criminal cases. In the case presented here, after the death of his 85-year-old... 相似文献
64.
65.
Barbara Dabrowska Robert Prejs Marcin Zdzienicki Ewa Walczak 《Clinical cardiology》1996,19(5):404-407
Background and hypothesis: ST-segment depression during acute myocardial infarction (AMI) is known to herald serious hemodynamic complications. Since the mechanism of this dependence is not clear, we reinvestigated the old concept of papillary muscle infarction (PMI) as a cause of marked ST depression. Methods: Autopsies and morpho-electrocardiographic correlations were performed in 53 patients with AMI involving one or both left ventricular papillary muscles, and in 10 patients with AMI, but without acute PMI. Results: ST-segment depression ≥l mm in at least two leads (mean 3.6 ± 2.2 mm) was found in 46 (86.8%) patients with, and in one without acute PMI. Thus, the sensitivity and specificity in selecting patients with acute PMI from among those with AMI were 86.8 and 90%, respectively, with an overall accuracy of diagnosis of acute PMI in the course of AMI of 87.3%. Among 26 patients with ST elevation consistent with diagnosis of AMI, ST depression, recorded in 22 patients, was insignificantly greater than in 24 of 27 patients without ST elevation: 4.1 ± 2.9 versus 3.1 ± 1.2 mm. Localization of ST depression in the limb leads allowed recognition of which papillary muscle suffered from acute infarction: ST depression in the inferior leads was seen only in patients with anterolateral PMI, whereas in leads I and/or aVL it was seen only in cases with posteromedial PMI. This rule was also valid in patients without concomitant ST elevation. Conclusion: Patients with acute PMI show marked ST-segment depression. Its location in the limb leads allows recognition of which papillary muscle has undergone necrosis. This cause of marked ST depression in patients with AMI may explain the high mortality in this particular group. 相似文献
66.
Dominika Dudek Marcin Siwek Daria Zielińska Rafał Jaeschke Janusz Rybakowski 《Journal of affective disorders》2013,144(1-2):112-115
BackgroundThe aim of the study was to check the stability of a diagnosis of major depressive disorder (MDD) in an outpatient setting, as well as to assess the scope of diagnostic conversions into bipolar disorder (BD).Methods: Retrospective chart review of 122 patients with a primary diagnosis of MDD.ResultsDiagnostic conversion from MDD into BD was noticed in 40 subjects (32.8%), 25 patients (20.5%) were treatment-resistant. Mean time to the conversion was 9.27±8.64 years. A negative correlation between the age of illness onset and time to diagnostic conversion was observed (?0.41; p<0.05). Earlier onset of MDD was associated with higher risk of diagnostic conversion (<30vs≥30 years of age at onset: 69% vs 28%, p=0.0001; <35vs≥35 years of age: 50% vs 25%, p=0.0065). Treatment-resistance was more prevalent in the BD conversion group (40% vs 11%; p=0.0002). Diagnostic conversion into BD was also related longer duration of treatment received, higher number of illness episodes, and higher number of hospitalizations.Limitations: Retrospective design of the study.ConclusionsThe problem of diagnosis evolution from MDD to BD was observed in about 1/3 of patients, and was associated with treatment-resistance of depression, earlier onset of depression, longer time of treatment, higher number of depressive episodes and hospitalizations. The variables above may be a useful predictor of bipolar diathesis. 相似文献
67.
68.
Jakubczak Andrzej Kowalczyk Marek Mazurkiewicz Ilona Kondracki Marcin 《Virus genes》2021,57(3):258-265
Virus Genes - Mink astrovirus infection remains a poorly understood disease entity, and the aetiological agent itself causes disease with a heterogeneous course, including gastrointestinal and... 相似文献
69.
Inhibition of CpG methylation improves the barrier integrity of bronchial epithelial cells in asthma
70.
Mariana Couto Alfred Bernard Luís Delgado Franchek Drobnic Marcin Kurowski André Moreira Rodrigo Rodrigues-Alves Maia Rukhadze Sven Seys Marta Wiszniewska Santiago Quirce 《Allergy》2021,76(11):3257-3275
Concerns have been raised regarding the potential negative effects on human health of water disinfectants used in swimming pools. Among the disinfection options, the approaches using chlorine-based products have been typically preferred. Chlorine readily reacts with natural organic matter that are introduced in the water mainly through the bathers, leading to the formation of potentially harmful chlorination by-products (CBPs). The formation of CBPs is of particular concern since some have been epidemiologically associated with the development of various clinical manifestations. The higher the concentration of volatile CBPs in the water, the higher their concentration in the air above the pool, and different routes of exposure to chemicals in swimming pools (water ingestion, skin absorption, and inhalation) contribute to the individual exposome. Some CBPs may affect the respiratory and skin health of those who stay indoor for long periods, such as swimming instructors, pool staff, and competitive swimmers. Whether those who use chlorinated pools as customers, particularly children, may also be affected has been a matter of debate. In this article, we discuss the current evidence regarding the health effects of both acute and chronic exposures in different populations (work-related exposures, intensive sports, and recreational attendance) and identify the main recommendations and unmet needs for research in this area. 相似文献