Elimination of the toxic effects of patulin onBacillus subtilis andB.megaterium by irradiation

Summary The bacteriological toxicity of patulin irradiated in aqueous solutions was investigated using two strains of bacteria,Bacillus subtilis andB. megaterium. The results of the plate cultivation test showed that the growth inhibition of both strains decreased in relation to absorbed dose. A dose of 1.8 kGy was sufficient to eliminate the bacteriological toxicity of patulin at an initial concentration of 125 g/ml. There was good correlation between the concentration of patulin in the irradiated solution as measured spectrophotometrically and that calculated from the diameter of the inhibition zone.

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Beseitigung der toxischen Wirkung von Patulin aufBacillus subtilis undB.megaterium durch Bestrahlung

Zusammenfassung Es wurde die Toxizität von Patulin nach der Bestrahlung in wäßrigen Losungen bei der Anwendung von zwei Bakterienstämmen,Bacillus subtilis undB. megaterium, untersucht. Die Ergebnisse des Plattenkultivierungstests haben gezeigt, daß die Wachstumsinhibition der beiden Stämme sich im Verhältnis zur Bestrahlungsdosis vermindert. Die Bestrahlungsdosis von 1,8 kGy war ausreichend zur Eliminierung der bakteriologischen Toxizität von Patulin bei der Anfangskonzentration von 125 g/ml. In den bestrahlten Lösungen wurde eine klare Korrelation zwischen der spektrophotometrisch gemessenen und der aus dem Durchmesser der Inhibitionszonen berechneten Patulinkonzentration festgestellt.

     

Creating a Water‐Soluble Resveratrol‐Based Antioxidant by Site‐Selective Enzymatic Glucosylation

The phytochemical resveratrol (trans‐3,5,4′‐trihydroxystilbene) has drawn great interest as health‐promoting food ingredient and potential therapeutic agent. However, resveratrol shows vanishingly low water solubility; this limits its uptake and complicates the development of effective therapeutic forms. Glycosylation should be useful to enhance resveratrol solubility, with the caveat that unselective attachment of sugars could destroy the molecule's antioxidant activity. UGT71A15 (a uridine 5′‐diphosphate α‐D ‐glucose‐dependent glucosyltransferase from apple) was used to synthesize resveratrol 3,5‐β‐D ‐diglucoside; this was about 1700‐fold more water‐soluble than the unglucosylated molecule (～0.18 mM ), yet retained most of the antioxidant activity. Resveratrol 3‐β‐D ‐glucoside, which is the naturally abundant form of resveratrol, was a practical substrate for perfect site‐selective conversion into the target diglucoside in quantitative yield (g L^?1 concentration).     

Improved high-voltage lateral RESURF MOSFETs in 4H-SiC

High-voltage lateral RESURF metal oxide semiconductor field effect transistors (MOSFETs) in 4H-SiC have been experimentally demonstrated, that block 900 V with a specific on-resistance of 0.5 Ω-cm² . The RESURF dose in 4H-SiC to maximize the avalanche breakdown voltage is almost an order of magnitude higher than that of silicon; however this high RESURF dose leads to oxide breakdown and reliability concerns in thin (100-200 nm) gate oxide devices due to high electric field (>3-4 MV/cm) in the oxide. Lighter RESURF doses and/or thicker gate oxides are required in SiC lateral MOSFETs to achieve highest breakdown voltage capability     

Klärung des spezifischen Korrosionsverhaltens von mikroporigen Chromüberzugssystemen in CaCl<Subscript>2</Subscript>-Elektrolyten

To describe the so-called Russian-mud corrosion of microporous chromium plating systems on decorative car parts, the corrosion behavior of this plating system has been studied in concentrated aqueous Calcium chloride electrolytes. Scanning electron microscopy (SEM) and energy dispersive x?ray spectroscopy (EDX) have been used to characterize the specific corrosion mechanism of corrosive stressed chromium plating systems from Russia. Potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) have been performed to evaluate the electrochemical corrosion behavior of each plating. Two different corrosion mechanisms can be identified to describe the corrosive attack, the dissolving of the chromium plating, and the undercutting of the chromium plating.     

Static Headspace Extraction with Compounds Trapping for the Analysis of Volatile Lipid Oxidation Products

Static headspace is an easy to perform, convenient, and usually automated method for extraction of volatiles from various food matrices. Among other applications, it is used also for monitoring of volatile lipid oxidation products. However, the biggest disadvantage of this method is its low sensitivity especially when compared to such techniques as solid-phase microextraction or dynamic headspace. This paper focuses on the comparison of static headspace analysis of volatile lipid oxidation products with a modification of this technique, where volatiles extracted multiple times from oil matrix in a headspace vial are trapped on Tenax trap and subsequently desorbed into gas chromatograph. Twenty volatile compounds (mainly alkanals, 2-alkenals, ketones, and alcohols being volatile lipid oxidation products) in rapeseed oil were used for method comparison. For all compounds, a significant increase in method sensitivity and improvement of limits of detection (10 to 33 times) depending on the compound were noted; however, the repeatability was worse (for 16 out of 20 compounds) and carry-over values (also 16/20) were higher for combined headspace/trapping method.     

The potential of different techniques for volatile compounds analysis coupled with PCA for the detection of the adulteration of olive oil with hazelnut oil

This paper investigates the effectiveness of three rapid methods of volatile compounds analysis with subsequent principal component analysis (PCA) treatment of data for differentiation between virgin olive oil samples adulterated with hazelnut oil. Tested methods included comparison of chromatograms of volatiles obtained using SPME-fast GC-FID, volatiles analysis by electronic nose based on MOS sensors (HS-Enose), and by direct coupling of SPME to MS (SPME-MS). Volatile compounds were analyzed also by SPME-GC/MS technique. Data obtained as a result of SPME-GC/MS was subjected to PCA. SPME-GC–MS analysis with subsequent PCA yielded good results, however being time consuming. The three methods of analysis of volatiles, with subsequent PCA treatment of data, allowed detection of olive oil adulteration with different contents of hazelnut oil ranging from 5 to 50% (v/v).     

Synaptic Alterations in a Transgenic Model of Tuberous Sclerosis Complex: Relevance to Autism Spectrum Disorders

Tuberous sclerosis complex (TSC) is a rare, multi-system genetic disease with serious neurological and mental symptoms, including autism. Mutations in the TSC1/TSC2 genes lead to the overactivation of mTOR signalling, which is also linked to nonsyndromic autism. Our aim was to analyse synaptic pathology in a transgenic model of TSC: two-month-old male B6;129S4-Tsc2^tm1Djk/J mice with Tsc2 haploinsufficiency. Significant brain-region-dependent alterations in the expression of several synaptic proteins were identified. The most prominent changes were observed in the immunoreactivity of presynaptic VAMP1/2 (ca. 50% increase) and phospho-synapsin-1 (Ser62/67) (ca. 80% increase). Transmission electron microscopy demonstrated serious ultrastructural abnormalities in synapses such as a blurred structure of synaptic density and a significantly increased number of synaptic vesicles. The impairment of synaptic mitochondrial ultrastructure was represented by excessive elongation, swelling, and blurred crista contours. Polyribosomes in the cytoplasm and swollen Golgi apparatus suggest possible impairment of protein metabolism. Moreover, the delamination of myelin and the presence of vacuolar structures in the cell nucleus were observed. We also report that Tsc2^+/− mice displayed increased brain weights and sizes. The behavioural analysis demonstrated the impairment of memory function, as established in the novel object recognition test. To summarise, our data indicate serious synaptic impairment in the brains of male Tsc2^+/− mice.