The Finite Pore Volume GAB Adsorption Isotherm Model as a Simple Tool to Estimate a Diameter of Cylindrical Nanopores.

The finite pore volume Guggenheim-Anderson-de Boer (fpv-GAB) adsorption isotherm model has been considered as a simple tool which not only enables us to analyze the shape of isotherms theoretically, but also provides information about pore diameter. The proposed methodology is based on the geometrical considerations and the division of the adsorption space into two parts: the monolayer and the multilayer space. The ratio of the volumes of these two spaces is unambiguously related to the pore diameter. This ratio can be simply determined from the N2 adsorption isotherm by its fitting with the use of fpv-GAB model. The volume ratio is equal to the ratio of the adsorption capacities in the monolayer and the multilayer-two of the best-fit parameters. The suggested approach has been verified using a series of isotherms simulated inside ideal carbon nanotubes. The adsorption data for some real adsorbents has also been used during tests. The studies performed have proven that diameters estimated with the use of the proposed method are comparable with the geometrical sizes or diameters published by others and based on the application of more sophisticated methods. For pores wider than 3 nm, the relative error does not exceed a few percent. The approach based on the fpv-GAB model reflects well the differences in pore sizes for the series of materials. Therefore, it can be treated as a convenient tool to compare various samples.

Occurrence and Risk Assessment of Mycotoxins through Polish Beer Consumption.

Poland is one of Europe's leading producers and exporters of beer. The study, herein, describes the measurement of ochratoxin A, deoxynivalenol, nivalenol, T-2 toxin, HT-2 toxin, diacetoxyscirpenol, and zearalenone levels in 69 Polish beers. Analytical methodologies based on high performance liquid chromatography (HPLC) with tandem mass spectrometry (MS/MS) and fluorescence detection were developed, validated, and used to perform the above determinations. The most prevalent mycotoxins were deoxynivalenol (96%), ochratoxin A (93%), and HT-2 toxin (74%), respectively. Three quarters of the samples contained at least three analytes. The mean ochratoxin A concentration was 0.057 (SD 0.065) ng/mL, and in four beer samples its level exceeded 0.2 ng/mL, a value postulated in the literature to be the maximum limit. Deoxynivalenol was found at a maximum level of 56.2 ng/mL, and its mean concentration was 17.1 (SD 9.0) ng/mL. An evaluation of the estimated daily intake (EDI) of mycotoxins from beer in different European populations was made using food-consumption data prepared by WHO. Based on the mean ochratoxin A concentration in beers, the EDI represented 0.8-1.1% of the tolerable daily intake (TDI), while in a worst-case scenario (maximum concentration) it reached 5.0-7.5% of TDI. For deoxynivalenol, the EDI was in the range of 4.1-6.0% of TDI, whereas, based on maximum values, it reached the level of 14-21% of TDI. There were no significant differences between "scenarios" in the HT-2 case (mean-5.0-7.5% of TDI; maximum-6.5-9.7% of TDI) due to the fact that its concentration was near the limit of quantification (LOQ) value taken for calculation. The significance of these results are discussed, herein.

Occupational exposure to mould and microbial metabolites during onion sorting--insights into an overlooked workplace.

Manual sorting of onions is known to be associated with a bioaerosol exposure. The study aimed to gain an initial indication as to what extent manual sorting of onions is also associated with mycotoxin exposure. Twelve representative samples of outer onion skins from different onion origins were sampled and analyzed with a multimycotoxin method comprising 40 mycotoxins using a single extraction step followed by liquid chromatography with electrospray ionization and triple quadrupole mass spectrometry. Six of the 12 samples were positive for mycotoxins. In those samples, deoxynivalenol, fumonisin B1, and B2 were observed in quantitatively detectable amounts of 3940 ng/g for fumonisin B1 and in the range of 126-587 ng/g for deoxynivalenol and 55-554 ng/g for fumonisin B2. Although the results point to a lower risk due to mycotoxins, the risk should not be completely neglected and has to be considered in the risk assessment.

Attenuation of plasma annexin A1 in human obesity.

Obesity-related metabolic disorders are characterized by mild chronic inflammation, leukocyte infiltration, and tissue fibrosis as a result of adipocytokine production from the expanding white adipose tissue. Annexin A1 (AnxA1) is an endogenous glucocorticoid regulated protein, which modulates systemic anti-inflammatory processes and, therefore, may be altered with increasing adiposity in humans. Paradoxically, we found that plasma AnxA1 concentrations inversely correlated with BMI, total percentage body fat, and waist-to-hip ratio in human subjects. Plasma AnxA1 was also inversely correlated with plasma concentrations of the acute-phase protein, C-reactive protein (CRP), and the adipocytokine leptin, suggesting that as systemic inflammation increases, anti-inflammatory AnxA1 is reduced. In addition, AnxA1 gene expression and protein were significantly up-regulated during adipogenesis in a human adipocyte cell line compared to vehicle alone, demonstrating for the first time that AnxA1 is expressed and excreted from human adipocytes. These data demonstrate a failure in the endogenous anti-inflammatory system to respond to increasing systemic inflammation resulting from expanding adipose tissue, a condition strongly linked to the development of type 2 diabetes and cardiovascular disease. These data raise the possibility that a reduction in plasma AnxA1 may contribute to the chronic inflammatory phenotype observed in human obesity.

The influence of raw material contamination with mycotoxins on alcoholic fermentation indicators.

The aim of the research was to describe the influence of selected mycotoxins on major factors (alcohol concentration, productivity, yield and energy) that are characteristic of the fermentation process of maize mashes. Indicators of the alcoholic fermentation of mashes made from raw material with low contaminations levels were compared with mashes obtained from raw material that was selectively contaminated with mycotoxins on the following concentrations: aflatoxin B(1)-11.65 ppb, B(2)-12.60 ppb, G(1)-12.34 ppb, G(2)-12.04 ppb; ochratoxin A-177.5 ppb; zearalenone-352 ppb; deoxynivalenol-2274 ppb; fumonisin B(1)-1875 ppb, B(2)-609 ppb, B(3)-195 ppb. It was found that, apart from fumonisin, all mycotoxins substantially affected the course of subsequent fermentation phases, in particular the first and the main fermentation phases. The highest drop in alcohol concentration at the main stage of the process amounted to 1% v/v and it was achieved by contamination with zearalenone. The statistically significant drop in the final fermentation yield was observed; this was caused by raw material contaminated with all studied mycotoxins, except for fumonisin. The decrease in ethanol yield in reference to the control variant ranged from 1.42 to 3.20 dm(3) of absolute alcohol out of 100 kg of starch, depending on a toxin.