Exposure assessment of process-related contaminants in food by biomarker monitoring

Exposure assessment is a fundamental part of the risk assessment paradigm, but can often present a number of challenges and uncertainties. This is especially the case for process contaminants formed during the processing, e.g. heating of food, since they are in part highly reactive and/or volatile, thus making exposure assessment by analysing contents in food unreliable. New approaches are therefore required to accurately assess consumer exposure and thus better inform the risk assessment. Such novel approaches may include the use of biomarkers, physiologically based kinetic (PBK) modelling-facilitated reverse dosimetry, and/or duplicate diet studies. This review focuses on the state of the art with respect to the use of biomarkers of exposure for the process contaminants acrylamide, 3-MCPD esters, glycidyl esters, furan and acrolein. From the overview presented, it becomes clear that the field of assessing human exposure to process-related contaminants in food by biomarker monitoring is promising and strongly developing. The current state of the art as well as the existing data gaps and challenges for the future were defined. They include (1) using PBK modelling and duplicate diet studies to establish, preferably in humans, correlations between external exposure and biomarkers; (2) elucidation of the possible endogenous formation of the process-related contaminants and the resulting biomarker levels; (3) the influence of inter-individual variations and how to include that in the biomarker-based exposure predictions; (4) the correction for confounding factors; (5) the value of the different biomarkers in relation to exposure scenario’s and risk assessment, and (6) the possibilities of novel methodologies. In spite of these challenges it can be concluded that biomarker-based exposure assessment provides a unique opportunity to more accurately assess consumer exposure to process-related contaminants in food and thus to better inform risk assessment

Peptide derived from Pvfp-1 as bioadhesive on bio-inert surface

National Natural Science Foundation of China [20725310, 90923042, 30900305]; Fundamental Research Funds for the Central Universities [2010121023]; key laboratory of Biomedical Material of TianjinSurface property is one important characteristic of materials, especially for ones that are bio-inert but designed for bin-medical application. In this study, we designed a series of peptides and compared their capacities as bioadhesive to improve the surface bioactivity of bio-inert material. The peptides were designed according to the sequence of Perna viridis foot protein 1 (Pvfp-1), one of the Mfp-1s (mussel foot protein 1) which play key roles in wet adhesion of mussel byssus. And the Teflon (PTFE) was chosen as a model of bio-inert material. With adsorption, adhesion and coating analysis, it was found that peptide C2 (M) (derived from the non-repeating region of Pvfp-1, contains modified DOPA) has superior coating and adhesion abilities especially on the bio-inert surface of PTFE. After coating with peptide C2 (M), the cell adhesion and spreading of osteoblast MC3T3-E1 cells on PTFE were significantly improved compared with those on non-coated surface, and the peptide-coating did not show any cell toxicity. Therefore. peptide C2 (M) is effective for improving the bioactivity of bio-inert PTFE, and could be potentially used as a bioadhesive on other bin-inert materials for biomedical application. Moreover, this study also provided new insights in designing other peptide-based bioadhesive materials. (C) 2011 Elsevier B.V. All rights reserved

Miniball: A Gamma-Ray Spectrometer With Position-Sensitive Ge Detectors For Nuclear Structure Studies At REX-ISOLDE

Miniball is a dedicated Ge detector array which has been developed for the investigation of rare decays at the new radioactive beam facility REX-ISOLDE [1, 2] at CERN. The array is optimised for high full-energy peak efficiency and for high granularity needed to perform Doppler corrections of -rays emitted by fast moving nuclei. Miniball will finally consist of 40 six-fold segmented, encapsulated detectors which are clustered in eight cryostats with three detectors each and four cryostats with four detectors, respectively. It is shown that from an analysis of the pulse shapes and of the amplitudes of the mirror charges in the adjacent segments the effective granularity of Miniball can be enhanced from 240 to 4000. The properties of Miniball are compiled on the basis of experimental data. Examples of the first data measured with Miniball are presented

Miniball: A Gamma-Ray Spectrometer with position-sensitive Ge Detectors for nuclear structure studies ar REX-ISOLDE

Miniball is a dedicated Ge detector array which has been developed for the investigation of rare decays at the new radioactive beam facility REX-ISOLDE [1, 2] at CERN. The array is optimised for high full-energy peak efficiency and for high granularity needed to perform Doppler corrections of gamma -rays emitted by fast moving nuclei. Miniball will finally consist of 40 six-fold segmented, encapsulated detectors which are clustered in eight cryostats with three detectors each and four cryostats with four detectors, respectively. It is shown that from an analysis of the pulse shapes and of the amplitudes of the mirror charges in the adjacent segments the effective granularity of Miniball can be enhanced from 240 to 4000. The properties of Miniball are compiled on the basis of experimental data. Examples of the first data measured with Miniball are presente