全文获取类型
收费全文 | 47492篇 |
免费 | 4361篇 |
国内免费 | 1644篇 |
专业分类
耳鼻咽喉 | 131篇 |
儿科学 | 629篇 |
妇产科学 | 986篇 |
基础医学 | 7077篇 |
口腔科学 | 1384篇 |
临床医学 | 4829篇 |
内科学 | 6756篇 |
皮肤病学 | 361篇 |
神经病学 | 6458篇 |
特种医学 | 1140篇 |
外科学 | 5037篇 |
综合类 | 4743篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 3831篇 |
眼科学 | 549篇 |
药学 | 6198篇 |
17篇 | |
中国医学 | 2128篇 |
肿瘤学 | 1240篇 |
出版年
2024年 | 187篇 |
2023年 | 853篇 |
2022年 | 1702篇 |
2021年 | 2276篇 |
2020年 | 2168篇 |
2019年 | 1820篇 |
2018年 | 1776篇 |
2017年 | 1983篇 |
2016年 | 2118篇 |
2015年 | 2054篇 |
2014年 | 3108篇 |
2013年 | 4220篇 |
2012年 | 2604篇 |
2011年 | 3010篇 |
2010年 | 2360篇 |
2009年 | 2495篇 |
2008年 | 2596篇 |
2007年 | 2209篇 |
2006年 | 2023篇 |
2005年 | 1587篇 |
2004年 | 1484篇 |
2003年 | 1281篇 |
2002年 | 997篇 |
2001年 | 862篇 |
2000年 | 739篇 |
1999年 | 601篇 |
1998年 | 558篇 |
1997年 | 489篇 |
1996年 | 430篇 |
1995年 | 324篇 |
1994年 | 288篇 |
1993年 | 234篇 |
1992年 | 252篇 |
1991年 | 223篇 |
1990年 | 207篇 |
1989年 | 192篇 |
1988年 | 165篇 |
1987年 | 125篇 |
1986年 | 127篇 |
1985年 | 152篇 |
1984年 | 126篇 |
1983年 | 75篇 |
1982年 | 83篇 |
1981年 | 66篇 |
1980年 | 61篇 |
1979年 | 60篇 |
1978年 | 46篇 |
1977年 | 30篇 |
1976年 | 27篇 |
1973年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
14.
Iva Justini Ana Kati Deni Uri
i Boena urko‐Cofek Branka Blagovi Gordana anadi Jurei 《Environmental toxicology》2020,35(3):346-358
The yeast Saccharomyces cerevisiae is a useful model for studying the influence of different stress factors on eukaryotic cells. In this work we used the pesticide imidacloprid, in the Confidor formulation, as the stress factor and analyzed its influence on the metabolic activity, proteome and lipid content and composition of Saccharomyces cerevisiae yeast. During the cultivation of yeast, the lowest recommended application dose of Confidor (0.025%, v/v) was added to the growth media and its influence on the mitochondria, cytosol with microsomes, and the whole yeast cells was monitored. The results show that under the stress provoked by the toxic effects of Confidor, yeast cells density significantly decreased and the percentage of metabolically disturbed cells significantly increased comparing with untreated control. Also, there was a downregulation of majority of glycolytic, gluconeogenesis, and TCA cycle enzymes (Fba1, Adh1, Hxk2, Tal1, Tdh1,Tdh3, Eno1) thus providing enough acetyl‐CoA for the lipid restructuring and accumulation mechanism since we have found the changes in the cell and mitochondrial lipid content and FA composition. This data suggest that lipids could be the molecules that orchestrate the answer of the cells in the stress response to the Confidor treatment. 相似文献
15.
Heat stress (HS) is a notable risk factor for female reproductive performance. In particular, impaired oocyte maturation was thought to contribute largely to the HS-induced reproductive dysfunctions. In this study, we confirmed that oocytes undergoing GVBD were much susceptible to HS, and thus compromising subsequent embryonic development. Using N-acetyl-l-cysteine (NAC), we found supplementation of a relatively high dose NAC during in vitro maturation, can protect oocytes from HS-induced complications, and thus rescuing impaired embryonic development. Further analysis indicated that mechanisms responsible for protecting GVBD oocytes from HS by NAC may include: (1) reversing disorganized spindle assembly and inhibited extracellular signal–regulated kinase (ERK) signaling; (2) correcting erroneous H3K27me3 modification and dysregulated expression of imprinted genes; (3) alleviating increased intraoocyte reactive oxygen species accumulation and apoptosis initiation. Our study, focusing on the oocyte meiotic maturation, may provide a safe and promising strategy for protecting reproductive sows under environmental hyperthermal conditions. 相似文献
16.
《Sleep medicine》2021
BackgroundTheoretical models argue that coping reduces stress responses, yet no studies have tested whether coping moderates the prospective stress effects on sleep in daily life.PurposeThis study tested if coping moderates the stress-sleep association using a daily, intensive longitudinal design across 7–12 days.Methods326 young adults (Mage = 23.24 ± 5.46) reported perceived stress and coping (problem-focused, emotional-approach, and avoidance) every evening between 20:00–02:00, providing over 2400 nights of sleep data and 3000 stress surveys from all participants. Actigraphy and sleep diaries measured total-sleep-time and sleep efficiency. Multilevel models tested the interaction effects of within- and between-person stress and coping on sleep.ResultsWithin-person problem-focused and emotional-approach coping moderated the within-person stress effects on actigraphic total-sleep-time (both p = 0.02); higher stress predicted shorter total-sleep-time only during high use of problem-focused or emotional-approach coping (both p = 0.01). Between-person avoidance moderated the between-person stress effect on actigraphic total-sleep-time (p = 0.04); higher stress predicted shorter total-sleep-time for high avoidance coping (p = 0.02). Within-person emotional-approach coping buffered the between-person stress effect on actigraphic sleep efficiency (p = 0.02); higher stress predicted higher sleep efficiency for high emotional-approach coping (p = 0.04).ConclusionsThis study showed that daily coping moderates the effects of evening stress on sleep that night. More efforts to cope with stress before bedtime had a short-term cost of shorter sleep that night. However, high use of emotional-approach coping buffered the impact of stress to promote sleep efficiency. 相似文献
17.
18.
《Gaceta sanitaria / S.E.S.P.A.S》2022,36(4):376-379
ObjectiveTo estimate the prospective relationships between exposure to psychosocial risks dimensions included in the COPSOQ-Istas21 and the deterioration of general and mental health and sleep problems among workers residing in Spain.MethodCohort whose baseline corresponds to the 2016 Psychosocial Risks Survey with a new measurement after one year.ResultsSocial capital and interpersonal relations and leadership dimensions, as well as work?life conflict, were related to all health variables. Dimensions of work organization and job contents did it especially with the mental health, the quantitative demands with the general health and the emotional ones with the mental health. The dimensions related to job insecurity did not show relationships with health.ConclusionsThe results obtained reinforce the role of the COPSOQ-Istas21 as a useful instrument for the evaluation and prevention of psychosocial risks at work. 相似文献
19.
Fahad Ali Rahul Smita Jyoti Ambreen Fatima Saba Khanam Falaq Naz Yasir Hasan Siddique 《Scientia pharmaceutica》2016,84(2):361-377
The present investigation was aimed at studying the possible role of curcumin against N-nitrosodiethylamine (NDEA)-induced toxicity in albino rats. Administration of NDEA to rats at a concentration of 0.1 mg/ml in drinking water ad libitum for 21 days produced toxicity in them, which was evident from histopathological changes in the rat livers, and increased levels of blood serum enzyme markers, i.e. aspartate transaminase, alanine transaminase, alkaline phosphatase, and lactate dehydrogenase. In addition, the levels of oxidative stress markers like lipid peroxidation (LPO), protein carbonyl (PCC), and glutathione-S-transferase (GST) activity were elevated and the total glutathione (GSH) content was reduced in the livers. The administration of curcumin to rats at concentrations of 10, 20, and 40 mg/ml in drinking water along with 0.1 mg/ml of NDEA for 21 days effectively suppressed NDEA-induced toxicity and also resulted in a dose-dependent reduction in the levels of blood serum enzyme markers (AST, ALT, ALP, and LDH). Moreover, LPO, PCC, and GST activity were reduced and the GSH level was increased upon the administration of curcumin along with NDEA. The results obtained for the comet assay in rat hepatocytes and blood lymphocytes showed a significant dose-dependent decrease in the mean tail length. The micronucleus assay performed on rat hepatocytes also showed a dose-dependent reduction in the frequency of micronucleated cells along with curcumin administration. These results suggest that curcumin has a protective role against NDEA-induced toxicity in albino rats. 相似文献
20.
Lauren Thaete 《Progress in Palliative Care》2019,27(1):10-13
Effective communication between clinicians, patients, and families at end of life is associated with better clinical outcomes. A large body of literature describes the key skills needed for effective communication. We believe that clinicians could also benefit from communication skills more commonly associated with business or law negotiations. We will demonstrate via analogy (i.e. buying a house) how four key business/law negotiation techniques – 1. Determine your Reservation and Aspiration Value; 2. Separate People from their Positions; 3. Separate Positions from Interests; and 4. Logrolling of Interests – can be applied to a difficult family meeting in a home hospice patient. 相似文献