Alcohol tolerance in humans is enhanced by prior caffeine antagonism of alcohol-induced impairment.

The author tested the hypothesis that a history of drug-induced antagonism of alcohol impairment would enhance alcohol tolerance in humans. Groups of participants (N = 21) repeatedly performed a psychomotor task under different drug treatments: 0.65 g/kg alcohol, 4 mg/kg caffeine, or both drugs combined. Tolerance to a 0.65 g/kg alcohol dose challenge was then tested. Results showed that a history of combined alcohol and caffeine administrations increased alcohol tolerance compared with an exposure history to either drug alone. The findings contribute to the understanding of the complexities of polydrug use history and provide a useful model to examine how alcohol tolerance might be affected by a history of coadministration with other drugs (e.g., cocaine and nicotine). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

间作下根际微生物控制土传病害的研究进展

为了解根际微生物在间作模式下有效控制土传病害的作用和机理,综述了间作系统对于根际微生物群落结构和代谢功能的影响,介绍了间作作物组合、作物品种选择和间作方式对根际微生物群落的影响,并从养分和宿主感染位点竞争、生防微生物的拮抗作用、植物化感自毒作用的缓解以及植物诱导系统抗性四个方面总结了与根际微生物相关的间作抗病机理。最后,讨论了现阶段间作抗病研究的局限性并对今后的研究方向进行了展望。     

Potential of Silver Nanoparticles in Overcoming the Intrinsic Resistance of Pseudomonas aeruginosa to Secondary Metabolites from Carnivorous Plants

Carnivorous plants are exemplary natural sources of secondary metabolites with biological activity. However, the therapeutic antimicrobial potential of these compounds is limited due to intrinsic resistance of selected bacterial pathogens, among which Pseudomonas aeruginosa represents an extreme example. The objective of the study was to overcome the intrinsic resistance of P. aeruginosa by combining silver nanoparticles (AgNPs) with secondary metabolites from selected carnivorous plant species. We employed the broth microdilution method, the checkerboard titration technique and comprehensive phytochemical analyses to define interactions between nanoparticles and active compounds from carnivorous plants. It has been confirmed that P. aeruginosa is resistant to a broad range of secondary metabolites from carnivorous plants, i.e., naphthoquinones, flavonoids, phenolic acids (MBC = 512 µg mL⁻¹) and only weakly sensitive to their mixtures, i.e., extracts and extracts’ fractions. However, it was shown that the antimicrobial activity of extracts and fractions with a significant level of naphthoquinone (plumbagin) was significantly enhanced by AgNPs. Our studies clearly demonstrated a crucial role of naphthoquinones in AgNPs and extract interaction, as well as depicted the potential of AgNPs to restore the bactericidal activity of naphthoquinones towards P. aeruginosa. Our findings indicate the significant potential of nanoparticles to modulate the activity of selected secondary metabolites and revisit their antimicrobial potential towards human pathogenic bacteria.     

将分数阶微分演算引入数字图像处理

为了系统论述图像分数阶微分对纹理细节的增强能力及其侧抑制原理,提出数字图像分数阶微分掩模及其运算规则。论述了分数阶微分的动力学物理意义并推导了分数阶微积分与经典时-频分析之间的关系,分析了在一定条件下二维分数阶微分的可分离性;其次,从信号处理和生物视觉神经模型两个角度提出图像分数阶微分的高斯差感受野模型,并分析其产生的特殊马赫现象;最后,提出并论述了数字图像分数阶微分掩模及其运算规则。计算机数值实验结果表明,对于纹理细节信息丰富的图像信号而言,分数阶微分对灰度变化不大的平滑区域中的纹理细节信息的增强效果明显优于整数阶微分运算。     

18个灵芝菌种的酯酶同工酶分析

对18个灵芝菌株进行了菌丝培养观察、拮抗试验和酯酶同工酶聚丙烯酰胺凝胶电泳实验，并对它们作了聚类统计分析。分析结果表明：在相似水平为50％时供试菌株聚合为6类：第1类包括以韩芝为代表的7个菌株；第2类包括以赤芝为代表的5个菌株；第3类包括紫芝和黑芝；第4类为血芝和京大灵芝；第5类为白芝；第6类为日本赤芝。聚类分析结果与形态特征及拮抗试验结果基本一致。实验还说明酯酶同工酶可作为灵芝良种选育的一种有效标记方法，在菌种鉴定、保藏和管理方面具有重要作用。     

Pathological Insight into 5-HT2B Receptor Activation in Fibrosing Interstitial Lung Diseases

Interstitial lung disease (ILD) encompasses a heterogeneous group of more than 200 conditions, of which primarily idiopathic pulmonary fibrosis (IPF), idiopathic nonspecific interstitial pneumonia, hypersensitivity pneumonitis, ILD associated with autoimmune diseases and sarcoidosis may present a progressive fibrosing (PF) phenotype. Despite different aetiology and histopathological patterns, the PF-ILDs have similarities regarding disease mechanisms with self-sustaining fibrosis, which suggests that the diseases may share common pathogenetic pathways. Previous studies show an enhanced activation of serotonergic signaling in pulmonary fibrosis, and the serotonin (5-HT)₂ receptors have been implicated to have important roles in observed profibrotic actions. Our research findings in support by others, demonstrate antifibrotic effects with 5-HT_2B receptor antagonists, alleviating several key events common for the fibrotic diseases such as myofibroblast differentiation and connective tissue deposition. In this review, we will address the potential role of 5-HT and in particular the 5-HT_2B receptors in three PF-ILDs: ILD associated with systemic sclerosis (SSc-ILD), ILD associated with rheumatoid arthritis (RA-ILD) and IPF. Highlighting the converging pathways in these diseases discloses the 5-HT_2B receptor as a potential disease target for PF-ILDs, which today have an urgent unmet need for therapeutic strategies.     

Additive-additive and additive-surface interactions in lubrication

Combinations of additives are often found to exhibit antagonistic or synergistic effects compared to the performance of the individual additives. This paper reviews the state of knowledge concerning such effects. Direct interactions, where two additives combine at a molecular level, are distinguished from complementary or exclusary effects where the individual contributions of separate additives enhance or reduce overall performance but with no direct interaction. Additive interactions take place in solution and at surfaces, and both are discussed.     

Microbes versus microbes: control of pathogens in the food chain

Foodborne illness continues as a considerable threat to public health. Despite improved hygiene management systems and increased regulation, pathogenic bacteria still contaminate food, causing sporadic cases of illness and disease outbreaks worldwide. For many centuries, microbial antagonism has been used in food processing to improve food safety. An understanding of the mode of action of this microbial antagonism has been gained in recent years and potential applications in food and feed safety are now being explored. This review focuses on the potential opportunities presented, and the limitations, of using microbial antagonism as a biocontrol mechanism to reduce contamination along the food chain; including animal feed as its first link. © 2014 Society of Chemical Industry     

放线菌BOS-009的分离、拮抗活性及鉴定

对从长白山不同海拔环境中分离筛选出可以产生抗菌活性物质的BOS-009放线菌菌株进行了研究,测定了该菌的抗菌谱,发现该菌株对多种植物病原性真菌及细菌有拮抗作用.通过形态特征、培养特征观察,生理生化特性及抑菌谱等系列比较.发现该菌株与链霉菌属的除虫链霉菌(Streptomyces avermitilis)的特征基本相符;通过16s rDAN序列比对,发现该菌株16s rDAN与除虫链霉菌的16s rDAN同源性达99%.根据多项分类原则和系统进化树的构建分析,将该菌株暂归入除虫链霉菌类.     

新概念无源干扰技术

在现代战争中,武器系统采用了电磁光谱诸如无线电波、微波、红外线、紫外线、X射线和伽马射线,为了与之对抗研究了烟雾以及其他干扰物,目前国外新概念无源干扰技术有：单向可见遮蔽烟幕,有时效性的电磁波干扰物、红外/毫米波双模干扰剂和红外/毫米波双模成像化诱饵,石墨弹和碳纤维弹等。