Removal of common Fusarium toxins in vitro by strains of Lactobacillus and Propionibacterium

This study was conducted to examine the ability of selected strains of Lactobacillus and Propionibacterium to remove common Fusarium toxins, trichothecenes, from liquid media. The trichothecenes studied were deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), nivalenol (NIV), fusarenon (FX), diacetoxyscirpenol (DAS), T-2 toxin (T-2) and HT-2 toxin (HT-2). The Lactobacillus rhamnosus strain GG (LGG), Lactobacillus rhamnosus strain LC-705 (LC-705) and Propionibacterium freudenreichii ssp. shermanii JS (PJS) were incubated in PBS buffer containing 20 µg toxin ml -1 for 1h at 37°C, and after centrifugation the concentration of the toxins was measured in the supernatant fraction. Both viable and heat-killed forms of LGG and PJS were more efficient than LC-705 in removing the toxins from the liquid media. LGG and PJS removed four of the seven tested toxins (the removal varying from 18 to 93%) and LC-705 two toxins (10-64%). Of the toxins, 3-AcDON was not removed by any of the bacteria; HT-2 was removed by the non-viable LGG and also slightly by non-viable LC-705; DAS was removed by all three bacteria tested. Binding is postulated as the possible mechanism of the removal, since no difference was observed between the ability of viable and heat-killed bacteria in removing the trichothecenes, and no degradation products of the toxins were detected by gas chromatography (GC)-mass spectrometry (MS) analysis. It is concluded that significant differences exist in the ability of the bacteria to bind trichothecenes in vitro.     

Ability of Bifidobacterium strains with acquired resistance to bile to adhere to human intestinal mucus

The hydrophobicity and capacity to adhere to human intestinal mucus of Bifidobacterium strains with acquired resistance to bile were assessed and compared with those of their more sensitive original strains. The resistant variants used were previously obtained [Int. J. Food Microbiol. 82 (2003) 191; Int. J. Food Microbiol. 94 (2004) 79] by progressive adaptation of originally more sensitive strains to gradually increasing concentrations of bile. In five out of the seven groups of original and bile-resistant variants tested the resistant strains showed higher adhesion levels to human mucus (range between 1.4- and 4-fold) than their corresponding original strains. However, in the presence of physiologic concentrations of bile (0.3%, w/v) the adhesion level of all Bifidobacterium strains dropped between 7% and 74%, depending on the strain. In spite of this, the adhesion capability of three bile-resistant variants remained higher than that of their originals. Hydrophobicity evidenced considerable variability; in four out of the seven bile-resistant strains it was higher than in the original strains, although no direct correlation between adhesion and hydrophobicity could be established. It was concluded that the acquisition of bile resistance by our Bifidobacterium strains promoted changes in hydrophobicity and in the adhesion of these microorganisms to human intestinal mucus.     

Human Studies on Probiotics: What Is Scientifically Proven

ABSTRACT: New knowledge has revealed that probiotics have specific properties and targets in the human intestinal tract. It is also understood that each probiotic strain, independent of the genera and species, is unique and the properties of each strain have to be assessed in a case-by-case manner. Human intervention studies are required for verification of probiotic properties. The basis of probiotics lies in the normal intestinal microbiota. The concept of healthy gut microbiota can be used in terms of preventing, correcting, and dietary manipulation of potential microbiota aberrancies. This is reflected in the search of probiotics with disease-specific properties. The effects of GI tract conditions, such as pH, bile, and digestive enzymes, on the survival and adhesion properties of probiotic bacteria have been documented. Various bacteria show different levels of tolerance to the GI conditions. Adhesion on intestinal surface lengthens the retention time of a probiotic, and it is particularly important for the small intestine. The residence time of material in the small intestine is relatively short. Such properties need to be clearly defined for probiotic microbes discovered in the future. An effective probiotic should reside at desirable target sites sufficiently long at sufficient concentrations to elicit probiotic effects. More research on the assessment of desirable dosages is urgently needed.     

Miscibility of Quillaja Saponins with other Co‐surfactants under Different pH Values

The miscibility behavior of mixed surfactant systems and the influence of extrinsic parameters are crucial for their application as emulsifiers. Therefore, the objective of this study was to evaluate the miscibility behavior of mixed systems composed of commercial Quillaja saponin and a co‐surfactant, namely sodium caseinate, pea protein, rapeseed lecithin, or egg lecithin. These mixtures were evaluated macro‐ and microscopically at different concentration ratios (maximum concentration 5% w/v) at pH 3, 5, and 7 at 25 °C. The individual ingredients were also assessed for their charge properties and surface hydrophobicity. The results showed that Quillaja saponin–caseinate mixtures were miscible only at pH 7, and showed aggregation and precipitation at lower pH due to increasing electrostatic attraction forces. Rheological measurements showed that Quillaja saponin‐pea protein mixtures formed gelled structures at all tested pH values mainly via association of hydrophobic patches. Quillaja saponins mixed with rapeseed lecithin were miscible at all tested pH values due to electrostatic repulsion. Quillaja saponin–egg lecithin mixtures aggregated independent of pH and concentration ratio. The microscopic analysis revealed that the lower the pH and the higher the Quillaja saponin ratio, the denser were the formed Quillaja saponin–egg lecithin aggregates. The results are summarized in ternary phase diagrams that provide a useful tool in selecting a surfactant system for food applications.     

A Comparison of the Reflection Properties of Dichromated Gelatin Gratings Developed in Different Ways

Abstract

Dichromated gelatin reflection gratings were developed in six different ways. The maximum of the reflection efficiency and its dependence on the wavelength were measured a day and a year after the development procedure. The differences in results between various development processes were analysed.     

新型低寄生电感模块的设计

寄生电感一直都是电力电子器件应用中需要克服的主要难题,尤其对于高频和大功率应用场合.模块内部的寄生电感会造成关断过程出现过电压,寄生参数会造成模块开关过程中的波形振荡,从而增加了电磁干扰和关断损耗.现在较常用的方法是把叠层直流母线引入到模块内部,但机械结构较复杂,而且成本较高,体积也较大.这里阐述了一种新的基于现有标准...     

Holographic self-amplification in amorphous As-Se semiconductor films

Abstract

Holographic self-amplification in amorphous As₅₅Se₄₅ and As₆₅Se₃₅ films has been studied. Results on this amplification over a wide range of initial diffraction efficiencies 10^?5% < η₀ < 1% are reported. The degree of amplification increases with decreasing η₀. At fixed values of η₀ and of the sample thickness, the maximum self-amplification corresponds to a period A = 2·0 μm of the grating hologram. An increase in the diffraction efficiency in the dark has been observed for the first time in As-Se films.     

A field‐sequential‐color display with a local‐primary‐desaturation backlight scheme

Abstract— Field‐sequential‐color technology eliminates the need for color filters in liquid‐crystal displays (LCDs) and results in significant power savings and higher resolution. But the LCD suffers from color breakup, which degrades image quality and limits practical applications. By controlling the backlight temporally and spatially, a so‐called local‐primary‐desaturation (LPD) backlight scheme was developed and implemented in a 180‐Hz optically compensated bend (OCB) mode LCD equipped with a backlight consisting of a matrix of light‐emitting diodes (LEDs). It restores image quality by suppressing color breakup and saves power because it has no color filter and uses local dimming. A perceptual experiment was implemented for verification, and the results showed that a field‐sequential‐color display with a local‐primary‐desaturation backlight reduced the color breakup from very annoying to not annoying and even invisible.     

3D‐Printable Photochromic Molecular Materials for Reversible Information Storage

The formulation of advanced molecular materials with bespoke polymeric ionic‐liquid matrices that stabilize and solubilize hybrid organic–inorganic polyoxometalates and allow their processing by additive manufacturing, is effectively demonstrated. The unique photo and redox properties of nanostructured polyoxometalates are translated across the scales (from molecular design to functional materials) to yield macroscopic functional devices with reversible photochromism. These properties open a range of potential applications including reversible information storage based on controlled topological and temporal reduction/oxidation of pre‐formed printed devices. This approach pushes the boundaries of 3D printing to the molecular limits, allowing the freedom of design enabled by 3D printing to be coupled with the molecular tuneability of polymerizable ionic liquids and the photoactivity and orbital engineering possible with hybrid polyoxometalates.     

Relationships between injuries at work and during leisure time

The aim of this study is to explore the relationships between injuries at work and during leisure time. Three independent but similar data sets based on the National Work and Health Survey were analyzed. A total of 2156 subjects participated this study in 1997, 2053 subjects in 2000, and 2335 subjects in 2003. In the interview the subjects reported their accidents at work, which had caused at least minor injury during the past 12 months. Workers involved in work injuries were significantly more often involved in leisure-time injuries (p<0.05). Less than 1% of the subjects were involved in both injuries at work and during leisure time during the past 12 months. We can conclude that involving in work injuries could increase the risk of leisure-time injuries.