20 research outputs found

    Detection of low molecular weight toxins using optical phase detection techniques

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    AbstractOptical methods based on recording a phase shift of electromagnetic waves offer high sensitivity for detection of bio-reactions. The method of Total Internal Reflection Ellipsometry (TIRE), which records simultaneously two parameters ι and Δ related, respectively, to the amplitudes and phases of p- and s-components of polarized light, was exploited here for detection of mycotoxins (T-2, zearalanone, and aflatoxin). The TIRE direct label-free immunoassay enables detecting the above mycotoxins in sub-ppb concentrations in water as well as in food extracts. Further enhancement of sensitivity can be achieved with the use of SiO2/Si3N4/SiO2 planar waveguides operating as polarization interferometers (PI)

    Detection of low molecular weight toxins using an optical phase method of ellipsometry

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    The method of total internal reflection ellipsometry (TIRE), which records simultaneously two parameters Δ and ι related to the amplitudes and phases of p- and s-components of polarised light, respectively, was exploited here for detection of mycotoxins (T-2 and zearalenone). The above mycotoxins in sub-ppb concentrations were detected using TIRE in both direct and competitive immunoassay. The study of immune reaction kinetics allowed the evaluation of adsorption/desorption rates and the association constant for zearalenone. The investigation of grain products samples revealed the presence of high concentrations of T-2 (>600 ng/ml) in mould products

    Increased total scavenger capacity in rats fed corticosterone and cortisol on lipid-rich diet.

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    Background: In our earlier studies both corticosterone and cortisol had antioxidant effect in vitro.Objectives: Our aim was to clarify whether corticosterone and cortisol oral administration results in beneficial antioxidant changes in Sprague-Dawley adult male rats in vivo.Methods: Experimental animals were fed a lipid rich diet and treated with corticosterone or cortisol in the drinking fluid. Control group was fed only lipid rich diet with untreated drinking water. The untreated group was fed a normal diet with untreated water. Total scavenger capacity (TSC) was measured before and after 4 weeks of treatment in blood samples using a chemiluminometric assay.Results: Both corticosterone and cortisol treatment caused increased TSC. The control group and the untreated group showed no significant changes in TSC. Conclusion: Our results support the hypothesis that corticosterone and cortisol administration can improve the antioxidant status not only in vitro but also in vivo

    Design, fabrication, and characterization of picowell arrays on cyclic olefin copolymer surfaces generated with a 10.5 MeV N4+ ion microbeam

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    Handling of picoliter-to-nanoliter-scale volumes and objects has increasing importance in life sciences. This is the volume scale of cell extractions and individual living cells. Here, we introduce a method of generating a picoliter-scale device by direct writing of picowell arrays on a ZEONORℱ copolymer surface with high-energy medium-mass ion microbeam. Arrays of various microstructures were written in the sample using a microbeam of 10.5 MeV N4+ ions at various implanted ion fluences. The best array was obtained by implantation of annuli of 10 and 11 ÎŒm of inner and outer diameters with a fluence of 7.8 × 1012 ions/cm2

    Rapid assays for environmental and biological monitoring

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    Rapid, inexpensive, sensitive, and selective enzyme linked immunosorbent assays (ELISAs) now are utilized in environmental science. In this laboratory, many ELISAs have been developed for pesticides and other toxic substances and also for their metabolites. Compounds for which ELISAs have recently been devised include insecticides (organophosphates, carbaryl, pyrethroids, and fenoxycarb), herbicides (s-triazines, arylureas, triclopyr, and bromacil), fungicides (myclobutanil), TCDD, and metabolites of naphthalene and toluene. New rapid assays have been developed for mercury
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