Spin-Polarized Calculations of Magnetic and Thermodynamic Properties of the Full-Heusler MnZ (Z = Al, Ga)
INTERNATIONAL JOURNAL OF THERMOPHYSICS
Authors: Mebsout, R.; Amari, S.; Mecabih, S.; Abbar, B.; Bouhafs, B.
Abstract
The purpose of this study is to further understanding of the structural, electronic, magnetic, and thermal properties of the full-Heusler compounds, MnAl and MnGa, using density functional theory. Electronic structure calculations will be performed using the full potential linear augmented plane wave. The electronic structures and magnetic properties of MnZ (Z = Al, Ga) compounds with structure are studied. It is shown that the calculated lattice constants and spin magnetic moments are in good agreement with experimental values using the general gradient approximation method. Thermal effects on some macroscopic properties of MnZ (Z = Al, Ga) compounds are predicted using the quasi-harmonic Debye model, in which the lattice vibrations are taken into account. The variations of the lattice constant, volume expansion coefficient, heat capacities, and Debye temperature with pressure and temperature in the ranges of 0 GPa to 18 GPa and 0 K to700 K have been obtained.
Appropriate First-Line Regimens to Combat Helicobacter pylori Antibiotic Resistance: An Asian Perspective
MOLECULES
Authors: Miftahussurur, Muhammad; Yamaoka, Yoshio
Abstract
Asia has the largest population of any continent and the highest incidence of gastric cancer in the world, making it very important in the context of Helicobacter pylori infection. According to current guidelines, standard triple therapy containing a proton pump inhibitor (PPI) and two antibiotics; amoxicillin (AMX) and clarithromycin (CAM) or metronidazole (MNZ), is still the preferred first-line regimen for treatment of H. pylori infection. However, the efficacy of legacy triple regimens has been seriously challenged, and they are gradually becoming ineffective. Moreover, some regions in Asia show patterns of emerging antimicrobial resistance. More effective regimens including the bismuth and non-bismuth quadruple, sequential, and dual-concomitant (hybrid) regimens are now replacing standard triple therapies as empirical first-line treatments on the basis of the understanding of the local prevalence of H. pylori antimicrobial resistance. Selection of PPI metabolized by the non-enzymatic pathway or minimal first pass metabolism and/or increasing dose of PPI are important to increase H. pylori eradication rates. Therefore, local antibiotic resistance surveillance updates, selection of appropriate first-line regimens with non-enzymatic PPI and/or increased doses of PPI, and detailed evaluation of patients' prior antibiotic usage are all essential information to combat H. pylori antibiotic resistance in Asia.