Patient skin dose measurement and risk of deterministic effect during fluoroscopy cardiac procedures.

This study aimed at assessing patient's peak skin doses (PSD) during fluoroscopy cardiac procedures and proposed a look up table to enhance patient's dose management. Perspex phantom and thermoluminescent dosemeters (TLD) were irradiated for different dose levels with X-ray equipment (Philips Azurion 7). It was found that PSD measures were higher than the kerma at the interventional reference point [K (IRP)] reported with factors 1.

Insight of UV-vis spectra and atmospheric implication for the reaction of ˙OH radical towards glyphosate herbicide and its hydrates.

The rate constant of the reactions of ˙OH radicals with glyphosate (GPS) and its hydrates (GPS(HO) ) were evaluated using the dual method M06-2X/6-311++G(df,p)//6-31+G(df,p) over the temperature range of 200-400 K. The results served to estimate the atmospheric lifetime along with the photochemical ozone creation potential (POCP). The calculations yielded an atmospheric lifetime of 2.

Theoretical investigation of the atmospheric implication for the reaction of OH radical with CFC(CH)-CX, X = H, F.

The atmospheric implication of the hydrofluoroolefines (HFO) CFC(CH)-CX, X=(H,F), through the reactions with OH radical were assessed using the M06-2X/6-311++G(df,p)//6-31+G(df,p) method. The rate coefficient was calculated over the temperature range 200-500 K, and was accurately expressed in non-Arrhenius form exp(a+bT+cT) cmmolecules, where a, b, and c are real constants. This served to estimate the atmospheric lifetime along with the photochemical ozone creation potential (POCP), which yielded lifetimes of 0.

Temperature-dependent oxidation of BSCAPE molecule in methanol medium.

Temperature-dependent solvation free energy and oxidation by free energy of ionization of 2-Phenylethyl (2E)-3-(1-benzenesulfonyl-4,5-dihydroxyphenyl) acrylate (BSCAPE) in methanol medium are the concerns of the present work. This molecule is a relevant phenolic acid enclosing multiple bioactivities. The explicit, implicit and discrete-continuum models of solvation were used.

Infrared spectra of PEHA molecule and its resistance to oxidation in water and methanol media at 298.15 K: solvent cluster size dependency.

The present work investigates the infrared spectra and solvation free energies (SE) of PEHA ((E)-2-(Pyridin-2-yl) ethyl 3-(3,4-dihydroxyphenyl) acrylate) and their impact on the oxidation. The latter was examined through the ionization potential parameter (IP). These investigations were carried out by the DFT method at B3LYP/6-31G(d) for optimization and frequency calculations and corrected for BSSE.

DFT Study of Photochemical Properties and Radiative Forcing Efficiency Features of the Stereoisomers - and -CHCl═CH-CF.

The accurate assessment of radiative forcing efficiency (RFE) of a greenhouse gas is based on the precise knowledge of its structure and infrared absorption spectrum. The present work investigates the UV-vis absorption spectra and IR absorption spectra that are used for the determination of RFE of the short-lived compounds, - and -CHCl═CHCF (CTFP). These investigations were carried out with six different density functional theory (DFT) methods B3LYP, CAM-B3LYP, M06, M06-2X, TPSS0, and ωB97X-D associated to the basis set 6-31G(3df).

Thermodynamic of solvation, solute - Solvent electron transfer and ionization potential of BSCAPE molecule and its UV-vis spectra in aqueous solution.

The molecular system 2-Phenylethyl (2E)-3-(1-benzenesulfonyl-4,5-dihydroxyphenyl) acrylate (BSCAPE) is a phenolic acid that covers a large spectrum of biological properties. The investigations of solvation and oxidation processes of BSCAPE molecule by computational means were the challenge of this present work. Water was required for solvation throughout the work.

Monte Carlo method for gamma spectrometry based on GEANT4 toolkit: Efficiency calibration of BE6530 detector.

The combination of gamma-ray spectrometry, the development of related Monte Carlo method and the GEANT4 (GEometry ANd Tracking) toolkit have been developed for gamma spectrometry simulation. The main objective was to validate simulation models of broad energy germanium (BEGe) detector geometry built in our laboratory (BE6530 model). Monte Carlo simulation of the geometry of BE6530 detector for efficiency calibration was carried out with GEANT4 toolkit.

Structure, antioxidative potency and potential scavenging of OH and OOH of phenylethyl-3,4-dihydroxyhydrocinnamate in protic and aprotic media: DFT study.

DFT methods including B3LYP, B3PW91 and M05-2x associated to 6-31+G(d,p) were used for the structural and antioxidant potency studies of phenylethyl-3,4-dihydroxy-hydrocinnamate (PDH). Solvents were employed according to their protric and aprotic character. So, calculated structures agree with the experimental data.

Precision measurement of radioactivity in gamma-rays spectrometry using two HPGe detectors (BEGe-6530 and GC0818-7600SL models) comparison techniques: Application to the soil measurement.

To obtain high quality of results in gamma spectrometry, it is necessary to select the best HPGe detector for particular measurements, to calibrate energy and efficiency of gamma detector as accurate as possible. To achieve this aim, the convenient detector model and gamma source can be very useful. The purpose of this study was to evaluate the soil specific activity using two HPGe model (BEGe-6530 and GC0818-7600SL) by comparing the results of the two detectors and the technics used according to the detector type.

Determination of (226)Ra, (232)Th, (40)K, (235)U and (238)U activity concentration and public dose assessment in soil samples from bauxite core deposits in Western Cameroon.

Determination of activity concentrations in twenty five (25) soil samples collected from various points in bauxite ore deposit in Menoua Division in Western of Cameroon was done using gamma spectrometry based Broad Energy Germanium (BEGe6530) detector. The average terrestrial radionuclides of (40)K, (226)Ra, (232)Th, (235)U and (238)U were measured as 671 ± 272, 125 ± 58, 157 ± 67, 6 ± 3 and 99 ± 69 Bq kg(-1), respectively. The observed activity concentrations of radionuclides were compared with other published values in the world.

DFT study of the effect of solvent on the H-atom transfer involved in the scavenging of the free radicals (·)HO2 and (·)O2(-) by caffeic acid phenethyl ester and some of its derivatives.

H-atom transfer from caffeic acid phenethyl ester (CAPE), MBC (3-methyl-2-butenyl caffeate), BC (benzoic caffeate), P3HC (phenethyl-3-hydroxycinnamate), and P4HC (phenethyl-4-hydroxycinnamate) to the selected free radicals (·)HO2 and (·)O2(-) was studied. Such a transfer can proceed in three different ways: concerted proton-coupled electron transfer (CPCET), electron transfer followed by proton transfer (ET-PT), and proton transfer followed by electron transfer (PT-ET). The latter pathway is sometimes competitive with SPLET (sequential proton loss electron transfer) in polar media.

Structures of protonated methanol clusters and temperature effects.

The accurate evaluation of pKa's, or solvation energies of the proton in methanol at a given temperature is subject to the determination of the most favored structures of various isomers of protonated (H(+)(MeOH)n) and neutral ((MeOH)n) methanol clusters in the gas phase and in methanol at that temperature. Solvation energies of the proton in a given medium, at a given temperature may help in the determination of proton affinities and proton dissociation energies related to the deprotonation process in that medium and at that temperature. pKa's are related to numerous properties of drugs.

Solvation Energies of the Proton in Methanol.

pKa's, proton affinities, and proton dissociation free energies characterize numerous properties of drugs and the antioxidant activity of some chemical compounds. Even with a higher computational level of theory, the uncertainty in the proton solvation free energy limits the accuracy of these parameters. We investigated the thermochemistry of the solvation of the proton in methanol within the cluster-continuum model.