43 research outputs found
Diet quality and depression risk: A systematic review and dose-response meta-analysis of prospective studies
Stress-related psychiatric disorders across the life spa
Study of a novel bisnaphthalimidopropyl polyamine as electroactive material for perchlorate-selective potentiometric sensors.
In this work, the new polyamine bisnaphthalimidopropyl-4,4'-diaminodiphenylmethane is proposed as a new ionophore for perchlorate potentiometric sensors. The optimal formulation for the membrane comprised of 12mmolkg-1 of the ionophore, and 68% (w/w) of 2-nitrophenyl phenyl ether as plasticizer and 31% (w/w) of high molecular weight PVC. The sensors were soaked in water for a week to allow leakage of anionic impurities and for one day in a perchlorate solution (10-4molL-1) to improve reproducibility due to its first usage. The stability constant for the ionophore-perchlorate association in the membrane, log βIL1=3.18±0.04, ensured a performance characterized by the slope of 54.1 (±0.7) mVdec-1 to perchlorate solutions with concentrations between 1.24×10-7 and 1.00×10-3molL-1. The sensors are insensitive to pH between 3.5 to 11.0, they have a practical detection limit of 7.66 (±0.42) ×10-8molL-1 and a response time below 60s for solutions with perchlorate concentrations above 5×10-6molL-1. The accuracy of the results was confirmed by the analysis of the contaminant in a certified reference water sample
Equations differentielles hautement non lineaires
SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc
Finatseride in the treatment of men with androgenetic alopecia using a phototrichogram technique
A new method for load matching in multimode microwave feating applicators based on the use of dielectric layer superposition
Usage of a dielectric multilayer around a dielectric Sample
is studied as a means for improving the efficiency in multimode microwave-
heating cavities. The results show that by using additional dielectric
constant layers the appearance of undesired reflections at the
sample-air interface is avoided and higher power -absorption rates
within the sample and high -efficiency designs are obtaine
Bemerkungen zur Verwendung von Flüssig-Membran-Elektroden für potentiometrische Titrationen
Production of fatty acid methyl esters and other bioactive compounds in elicited cultures of the fungus Mucor circinelloides
In this work, the production of carotenoids and volatile compounds in Mucor circinelloides cell cultures treated with methyl jasmonate (MJ) and/or cyclodextrins (CD) was evaluated. CD increased the lutein concentration in the extracellular medium, reaching the highest levels in the combined treatment with MJ, whereas the levels of β-carotene were low. Therefore, the addition of CD to M. circinelloides cultures provokes a release of these compounds into the culture medium. Mucor circinelloides cultures also produced lichesterol, neoergosterol and ergone, suggesting that, under these stress conditions, this fungus diverts the carbon flow to sterol biosynthesis, which, in turn, is required for its survival. More interestingly, CD induced the secretion of sterols in a similar way to carotenoids. Mucor circinelloides cultures treated with MJ and/or CD also produced fatty acid methyl esters (FAMEs) and, in the presence of CD, they were released to culture medium, contributing to the formation of biodiesel. In this way, M. circinelloides cultures produced compounds of biotechnological interest and, therefore, these treated cultures can provide an alternative system, which is, at the same time, more sustainable, economical and ecological for their production
Background current elimination in thin layer ion-selective membrane coulometry
A promising method for the elimination of undesired capacitive currents in view of realizing a potentially calibration free coulometric ion detection system is presented. The coulometric cell is composed of a porous polypropylene tube doped with a liquid calcium-selective membrane and a silver/silver chloride wire as an inner electrode, forming a thin layer sample between wire and tubing. The total charge passed through the system during potential controlled electrolysis of the thin layer sample is indeed found to be proportional to the amount of calcium present, but non-Faradaic processes do contribute to the obtained signal. We introduce here a multi-pulse procedure that allows one to perform a second excitation pulse at the same excitation potential after exhaustive ion transfer voltammetry of calcium has taken place. The intercept of the calibration curve after background subtraction is found as 20.6 ± 0.6 μC, significantly lower than the value of 54.1 ± 0.8 μC for the uncorrected curve. Changes in sample temperature (from 23 °C to 38 °C) did equally not affect the background corrected coulometric readings, supporting that the procedure renders the readout principle more robust