Brain glutathione redox system significance for the control of silica-coated magnetite nanoparticles with or without mercury co-exposures mediated oxidative stress in European eel (Anguilla anguilla L.)

This in vitro study investigates the impact of silicacoated magnetite particles (Fe3O4@SiO2/SiDTC, hereafter called IONP; 2.5 mg L-1) and its interference with coexposure to persistent contaminant (mercury, Hg; 50 mu g L-1) during 0, 2, 4, 8, 16, 24, 48, and 72 h on European eel (Anguilla anguilla) brain and evaluates the significance of the glutathione (GSH) redox system in this context. The extent of damage (membrane lipid peroxidation, measured as thiobarbituric acid reactive substances, TBARS; protein oxidation, measured as reactive carbonyls, RCs) decreased with increasing period of exposure to IONP or IONP + Hg which was accompanied with differential responses of glutathione redox system major components (glutathione reductase, GR; glutathione peroxidase, GPX; total GSH, TGSH). The occurrence of antagonism between IONP and Hg impacts was evident at late hour (72 h), where significantly decreased TBARS and RC levels and GR and glutathione sulfotransferase (GST) activity imply the positive effect of IONP + Hg concomitant exposure against Hg-accrued negative impacts [vs. early (2 h) hour of exposure]. A period of exposuredependent IONP alone and IONP + Hg joint exposureaccrued impact was perceptible. Additionally, increased susceptibility of the GSH redox system to increased period of exposure to Hg was depicted, where insufficiency of elevated GR for the maintenance of TGSH required for membrane lipid and cellular protein protection was displayed. Overall, a finetuning among brain glutathione redox system components was revealed controlling IONP + Hg interactive impacts successfully

Fiber Optic Sensors Based On Multicore Structures

We present a review of the fundamentals and applications of fiber optic sensors based on multicore coupled structures. The fundamentals of these coupled structures are approached in general for arbitrary distributions of N cores on the foundations of coupled mode theory. The principle of operation of fiber optic sensors using this type of architectures is illustrated via numerical simulations of the simplest coupled structure—the two-core fiber. Illustrative experimental results using fiber optic sensors based on two- and seven-core multicore fibers are shown for a number of applications including temperature, curvature, and refractive index sensing. The main aspects of the performance of multicore fiber sensors are highlighted throughout this chapter and their characteristics, especially their sensitivity, are compared to those of other existing fiber sensing architectures such as fiber Bragg gratings, long period gratings, and photonic crystal fibers, among others