首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   123篇
  免费   2篇
  2021年   3篇
  2019年   2篇
  2018年   1篇
  2017年   2篇
  2016年   7篇
  2015年   8篇
  2014年   6篇
  2013年   8篇
  2012年   6篇
  2011年   8篇
  2010年   5篇
  2009年   4篇
  2008年   7篇
  2007年   7篇
  2006年   4篇
  2005年   6篇
  2004年   14篇
  2003年   4篇
  2002年   3篇
  2001年   2篇
  2000年   3篇
  1999年   2篇
  1996年   1篇
  1995年   1篇
  1987年   2篇
  1986年   1篇
  1985年   2篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
排序方式: 共有125条查询结果,搜索用时 93 毫秒
1.
Summary The influence of moisture content and temperature during storage of grain on the formation of Fusarium metabolites was studied. Naturally and artificially contaminated barley grain samples were stored at 15%, 25%, and 30% moisture contents, and at temperatures of + 5°C + 25°C, and + 30°C. Time of storage varied between one week and six months and the occurrence of Fusarium species and metabolites was analysed. The only Fusarium metabolite detected was zearalenone. The extent of Fusarium contamination decreased during storage whilst the concentration of zearalenone increased. To avoid the danger of mycotoxicoses, grains must be dryed immediately after harvest and then stored at a low temperature.  相似文献   
2.
Ischemic stroke is confounded by conditions such as atherosclerosis, diabetes, and infection, all of which alter peripheral inflammatory processes with concomitant impact on stroke outcome. The majority of the stroke patients are elderly, but the impact of interactions between aging and inflammation on stroke remains unknown. We thus investigated the influence of age on the outcome of stroke in animals predisposed to systemic chronic infection. Th1‐polarized chronic systemic infection was induced in 18–22 month and 4‐month‐old C57BL/6j mice by administration of Trichuris muris (gut parasite). One month after infection, mice underwent permanent middle cerebral artery occlusion and infarct size, brain gliosis, and brain and plasma cytokine profiles were analyzed. Chronic infection increased the infarct size in aged but not in young mice at 24 h. Aged, ischemic mice showed altered plasma and brain cytokine responses, while the lesion size correlated with plasma prestroke levels of RANTES. Moreover, the old, infected mice exhibited significantly increased neutrophil recruitment and upregulation of both plasma interleukin‐17α and tumor necrosis factor‐α levels. Neither age nor infection status alone or in combination altered the ischemia‐induced brain microgliosis. Our results show that chronic peripheral infection in aged animals renders the brain more vulnerable to ischemic insults, possibly by increasing the invasion of neutrophils and altering the inflammation status in the blood and brain. Understanding the interactions between age and infections is crucial for developing a better therapeutic regimen for ischemic stroke and when modeling it as a disease of the elderly.  相似文献   
3.

Background

Previous cohort studies have shown that persons with Alzheimer’s disease (AD) have a higher risk of hip fractures but recent data from large representative cohorts is scarce.

Methods

We investigated the association between AD and prevalent and incident hip fractures in an exposure-matched cohort study conducted in Finland 2002–2009 (the Medication and Alzheimer’s disease in 2005 study; MEDALZ-2005). The study population included all community-dwelling persons with verified AD diagnosis in Finland on December 31, 2005 and one matched comparison person per AD case (N = 56,186, mean age 79.9 (SD 6.8) years, range 42–101 years). The diagnosis of AD was extracted from a special reimbursement register. Data on hip fractures during 2002–2009 was extracted from the Finnish National hospital discharge register. Analyses of incident hip fractures (n = 2,861) were restricted to years 2006–2009.

Results

Persons with AD were twice as likely to have previous hip fracture in 2005 (odds ratio, 95% confidence interval 2.00, 1.82–2.20) than matched aged population without AD. They were also more likely to experience incident hip fracture during the four-year follow-up (hazard ratio, 95% confidence interval 2.57, 2.32–2.84, adjusted for health status, psychotropic drug and bisphosphonate use). The AD-associated risk increase decreased linearly across age groups. Although people with AD had higher risk of hip fractures regardless of sex, the risk increase was larger in men than women.

Conclusion

Findings from our nationwide study are in line with previous studies showing that persons with AD, regardless of sex or age, have higher risk of hip fracture in comparison to general population. Although there was some suggestion of effect modification by age or sex, AD was consistently associated with doubling of the risk of incident hip fracture.  相似文献   
4.
记述了采自萨哈林岛1新种,Alopecosa mikhailovi sp.nov.,2♂♂,新种与solivaga种团近似.  相似文献   
5.
This paper reports seven species found in Shirabad Cave located in the western part of Golestan Province and two species found nearby. Three families: Anyphaenidae, Segestriidae and Theridiosomatidae, and one species, Metellina merianae (Scopoli, 1763) are recorded from Iran for the first time. Two species are described as new: Tegenaria zamanii Marusik & Omelko, sp.n. (♀) and Segestria mirshamsii Marusik & Omelko, sp.n. (♀). Four species: Lepthyphantes iranicus Saaristo & Tanasevitch, 1996, Metellina merianae, Octonoba yesoensis (Saito, 1934) and Pholcus sp. are illustrated. Uloborus georgicus Mcheidze, 1997 from Eastern Georgia is synonymized with Octonoba yesoensis. The distribution of all species treated in the paper is briefly discussed, with emphasis on the easternmost records.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:614A0FF0-40B0-4A7E-B2B8-C6B117A80AFE  相似文献   
6.
Pre-eclampsia is a leading cause of maternal and perinatal morbidity and mortality worldwide. The etiology is not clear, but an immune attack towards components of placenta or fetus has been indicated. This involves activation of the complement system in the placenta. We have previously described the presence of the complement-regulating protein salivary scavenger and agglutinin (SALSA) in amniotic fluid. In this study we investigated the potential role of SALSA in pregnancy by analyzing its presence in amniotic fluid and placental tissue during healthy and complicated pregnancies. SALSA levels in amniotic fluid increased during pregnancy. Before 20 weeks of gestation the levels were slightly higher in patients who later developed pre-eclampsia than in gestation age-matched controls. In the placenta of pre-eclamptic patients syncytial damage is often followed by the formation of fibrinoid structures. SALSA was found clustered into these fibrinoid structures in partial co-localization with complement C1q and fibronectin. In vitro analysis showed direct protein binding of SALSA to fibronectin. SALSA binds also to fibrin/fibrinogen but did not interfere with the blood clotting process in vitro. Thus, in addition to antimicrobial defense and epithelial differentiation, the data presented here suggest that SALSA, together with fibronectin and C1q, may be involved in the containment of injured placental structures into fibrinoids.  相似文献   
7.
Truncated trkB.T1 (T1) neurotrophin receptor inhibits full-length trkB.TK+ (TK+) signaling. At least two possible mechanisms have been proposed for this action: T1 could trap the ligand or function as a dominant negative receptor. To differentiate between these possibilities we have studied survival of serum-deprived PC12-trkB cells stably expressing TK+. PC12-trkB cells were observed to display constitutive trkB kinase activity which leads to survival of a cell subpopulation in the absence of added brain-derived neurotrophic factor (BDNF) and serum. Exogenous BDNF significantly increased cell survival, and this increase was inhibited by BDNF neutralizing antibody. The antibody treatment had no effect on the constitutive TK+ activity. Transfected T1 completely inhibited survival by BDNF or constitutive trkB kinase activity in PC12-trkB cells similarly to tyrosine kinase inhibitor K252a. In addition, T1 coimmunoprecipitated with TK+ and inhibited its autophosphorylation by BDNF. These data suggest that truncated T1 inhibits TK+ signaling by dominant negative action.  相似文献   
8.
9.

Aim

Interleukin-10 (IL-10) has been associated with wheezing and asthma in children and the genetic variation of the IL-10 cytokine production may be linked to post-bronchiolitis lung function. We used impulse oscillometry (IOS) to evaluate the associations of IL10 polymorphisms with lung function at a median age of 6.3 years in children hospitalised for bronchiolitis before six months of age.

Methods

We performed baseline and post-exercise IOS on 103 former bronchiolitis patients. Data on single nucleotide polymorphisms (SNP) of IL10 rs1800896 (–1082G/A), rs1800871 (–819C/T), rs1800872 (–592C/A) were available for 99 children and of IL10 rs1800890 (–3575T/A) for 98 children.

Results

IL10 rs1800896, rs1800871 and rs1800872 combined genotype AA+CT+CA and carriage of haplotype ATA, respectively, were associated with higher resistance and lower reactance in baseline IOS in adjusted analyses. At IL10 rs1800890, the A/A-genotype and carriers of A-allele were associated with lower reactance in baseline IOS. There were no significant associations between the studied SNPs and airway hyper-reactivity to exercise.

Conclusion

Low-IL-10-producing polymorphisms in the IL-10 encoding gene were associated with obstructive lung function parameters, suggesting an important role for IL-10 in development of lung function deficit in early bronchiolitis patients.  相似文献   
10.
In this work alternative media for detection and enumeration of E. coli and coliform bacteria were compared to the reference method ISO 9308-1 (LTTC) using non-disinfected water samples with background flora. The alternative media included LES Endo agar medium (LES Endo), Colilert-18 with 51-well Quanti-tray (Colilert), Chromocult Coliform agar (CC), Harlequin E. coli/Coliform medium (HECM) and Chromogenic Escherichia coli/Coliform medium (CECM). A total of 110 samples of groundwater, bathing water and spiked water was used. Our results revealed that confirmation of coliform bacteria counts is necessary, not only on lactose-based LTTC and LES Endo media, but also on the chromogenic agar media tested, due to the growth of oxidase positive colonies. LTTC and CC media also allowed the growth of some morphologically typical coliform colonies containing gram-positive bacteria. The recovery of coliform bacteria was lower on LES Endo than on LTTC. In most cases Colilert, CC, HECM and CECM gave higher coliform counts than LTTC. The use of the LTTC medium led to higher E. coli counts than obtained with any of the alternative mediums. There are three explanations for this: (1) high sensitivity of LTTC, (2) false positives on LTTC or (3) false negatives especially with Colilert, but also with chromogenic agar media. Although LTTC was found to be a very sensitive medium, the high degree of background growth of non-disinfected waters disturbed substantially the use of it. In conclusion, our results suggest that Colilert, CC and CECM are potential alternative media for detection of coliform bacteria and E. coli from non-disinfected water.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号