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Listeria monocytogenes is able to form biofilms on food contact surfaces. Effectiveness of salt concentration, pH, and temperature on the formation of L. monocytogenes biofilms was evaluated individually and in combinations using microtiter plate assay by measuring the optical density. The tested strains differed in their biofilm formation (low, moderate, and strong) ability. At 37 °C, decreasing amounts of biofilms was observed in almost all L. monocytogenes strains when the NaCl concentration increased from 0.05 to 15%, but all strains were able to form biofilm even at 1 °C. There was no significant difference in biofilm formation between pH 4, 5, and 6, except for some strains. When stress conditions were tested in combination, the addition of 15% NaCl significantly inhibited the growth of L. monocytogenes at 1 °C and 4 °C, and the weak biofilm-forming strains were less sensitive to the temperature and to NaCl treatments than the strong biofilm-forming strains. These results enhance our knowledge of the application of NaCl, temperature, and pH stresses in the food industry and provide basis to develop new strategies for control of biofilm formation of this pathogen. [ABSTRACT FROM AUTHOR]

Using the first principal study, we present and discuss the structural, electronic, and magnetic properties of an ordered double perovskite Ba2FeMoO6 in the cubic (Fm-3 m) and tetragonal (I4/mmm) symmetries. The phase stability for ferromagnetic and paramagnetic states has been treated by applying the generalized gradient approximation (GGA-08). Moreover, the calculated lattice parameters are found to be in good agreement with experimental data. For understanding the electronic properties in the studies Ba2FeMoO6, band structure, and total and partial density of states have also been performed and discussed thoroughly. On the other hand, the Monte Carlo simulations were used to study the magnetic properties of Ba2FeMoO6. The Curie temperature was established. The magnetic entropy changes and relative cooling power were deduced. Finally, the magnetic hysteresis cycle was given. The tunability of TC and magnetocaloric properties, the reversible magnetocaloric effect, and the simple fabrication of the samples investigated here suggest a new research area for the development more promising magnetic coolers. [ABSTRACT FROM AUTHOR]

The La0.7Sr0.3Mn0.95Fe0.05O3 sample has been prepared by solid-state method. The crystallographic analysis demonstrates that the sample crystallizes with the P n m a space group in the orthorhombic structure. For the morphologic study, the size counting garnered from SEM images, the value of the average grain size is DSEM = 140 nm. A phenomenological model is used in present research work to explain the magnetocaloric effect. Using the measurements of magnetization, the magnetocaloric properties are estimated under different external magnetic fields based on this model. Additionally, based on the modified Bean–Rodbell model, we theoretically studied the magnetocaloric properties of the elaborated material with consideration of the magnetic disorder effect. [ABSTRACT FROM AUTHOR]

Structural, electronic, magnetic and mechanical properties of the Co2MnGa have been calculated with functional density theory using full potential linear augmented plane wave method as implemented in the Wien2k code. Exchange correlation effects for these properties are treated by generalized gradient approximation while for electronic and magnetic properties, in addition to (WC-GGA) correction, mBJ-GGA scheme was also applied. The stiffness constant of the spin wave and the Curie temperature are calculated. Moreover, mechanical parameters included three elastic constants, compression modulus, Young's modulus and shear modulus are also investigated. This theoretical study provides detailed information on the compound Co2MnGa, in different aspects and can also provide information on the application of this material. Obtained data from abinitio calculations are used as input for Monte Carlo simulations to study the magnetic properties and magnetocaloric effect. Transition temperature, magnetic entropy change, adiabatic temperature change and relative cooling power were found. [ABSTRACT FROM AUTHOR]

Crystal structure investigations of R2Fe17 (R = Nd and Gd) have been performed with X-ray powder diffraction. The experimental results and Monte Carlo studies have been used to study the magnetic properties and magnetocaloric effect of R2Fe17 (R = Nd and Gd) compounds. The Curie temperatures have been deduced using the both methods. The variation of magnetic entropy change and magnetic field was given. Finally, we have determined the relative cooling power for a fixed temperature value and for a several magnetic field using Monte Carlo simulations. [ABSTRACT FROM AUTHOR]

The ground-state properties of ZnO compound in the Wurtzite-type structure are investigated using the optimization of total-energy calculations based on the full-potential augmented plane-wave (FP-LAPW) method within the density functional theory (DFT). The exchange–correlation potential for structural properties is calculated by the generalized gradient approximation (GGA), while for electronic properties, the Engel and Vosko GGA (EV-GGA) as well the modified Becke–Johnson (mBJ) schemes are applied. The equilibrium lattice constants (a, c and μ) and bulk modulus are found in good agreement with the available reported data. On the other hand, the estimated mBJ energy band gap value is found in good agreement with the literature. In addition, the influence of pressure and temperature on the evolution of lattice constants (a, c and μ), bulk modulus, energy gap, heat capacity, and thermal expansion coefficient are investigated as function of pressure (0–10 GPa) and temperature (0–1000 K). [ABSTRACT FROM AUTHOR]

Byline: H. Mahjoubi, S. Labidi, S. Mtimet, F. Essafi, F. Ben Cheikh A study of the natural radioactivity and artificial radioactivity of soils due to gamma ray emitters was performed in Tunisia, as part of the national programme for environment surveillance. Seventeen sites were studied. The determination of radionuclide specific concentrations in the soil samples (05 cm) by gamma ray spectrometry showed the following ranges: 40K (93319 Bq/kg), 226Ra (550 Bq/kg) and 232Th (530 Bq/kg) and 137Cs (119 Bq/kg). From the measured concentrations we estimated the gamma dose rates due to each radionuclide, and the calculated dose rates (832 nGy/h) corresponding to the terrestrial component were compared to the total external dose rates measured in air, by a sensitive scintillometer (42 and 101 nGy/h). The differences between calculated and measured dose rates may be explained partially by the cosmic component. The results of equivalent dose (0.20.54 mSv/y) showed a median value of 0.41 mSv/y for residents in the meteorological stations adjacent to the sample locations.

The first principles calculations of structural and magnetic properties of the Heusler material Mn2NiAl, have been studied using a full potential linearized augmented plane wave (FP-LAPW) within the density-functional theory (DFT). The phase stability of the cubic austenitic (L21) structure for Mn2NiAl in both Cu2MnAl (Fm3 m space group) and Hg2CuTi (F43 m space group) type of structures with ferromagnetic and antiferromagnetic states, has been treated by applying the generalized gradient approximation proposed by Wu and Cohen (WC-GGA) alongside with the martensitic structure of Mn2NiAl. The analysis of phase stability, cohesive energy and the calculated formation enthalpy of Mn2NiAl reveal that the ferromagnetic MnMnNiAl is the most stable type of structure. Moreover, the calculated lattice parameters are found to be in good agreement with theoretical data. The variation of total magnetic moments MT(μB), MMn (μB), MNi (μB) and MAl (μB) in Mn2NiAl with pressure at varying temperature (0, 273 and 344 K), have been calculated. [ABSTRACT FROM AUTHOR]

A 56-year-old male was treated by local surgery in 1968 and 2005 for a left thigh lesion. A 2nd local relapse occurred in 2015 and was treated by complete macroscopic surgery with histology concluding to a hidradenocarcinoma. A 3rd locoregional relapse occurred in October 2018, with the presence of inflammatory ulcerated lesions. A 2nd histology and immunohistochemistry exam showed a proliferation positive for CK, CK5, and p63 suggesting the diagnosis of hidradenocarcinoma. The patient was treated by 3 lines of chemotherapy, 1st by Adriamycin, 2nd by carboplatin-paclitaxel, and then 3rd by oral capecitabine, leading to a stable clinical disease but without a clinical benefit. A locoregional plus metastatic lung progression was observed in March 2019, with the presence of lung nodules and retroperitoneal lymph nodes, multiple skin left thigh and left inguinal ulcerated lesions. The patient received then in 4th line in April 2019 oral sunitinib at 50 mg daily, with 4 weeks therapy/2 weeks pause. Side effects were represented by mucositis, anorexia, weight loss, and fatigue. We observed since the 1st week of therapy a fast response, with a decrease of the ulcerated lesions, a skin loss, and deep hemorrhagic areas. CT-scan showed after 2 weeks of sunitinib an objective response on both locoregional and metastatic lesions. [ABSTRACT FROM AUTHOR]

Structural, electronic, magnetic and thermodynamic main features for Ni1-xTixO ternary alloys in rock-salt structure with Ti content in the range 0≤x≤1 were studied using the full potential Linearized augmented plane wave (FP-LAPW) method within density functional theory. The exchangecorrelation potential was calculated by the generalized gradient approximation. The analysis of the electronic density of states curves allowed the computation of the magnetic moments which are considered to lie along (010) axes. The thermodynamic stability of this alloy was investigated by calculating the excess enthalpy of mixing ΔHm as well as the phase diagram. In addition, the Monte Carlo simulations have been exploited to calculate the transition temperature and magnetic coercive field in the alloy. [ABSTRACT FROM AUTHOR]

We report on the elaboration of nanoparticulate SO42--ZrO2 solid acid catalyst for conversion of free fatty acids into biofuel. Three different morphological modifications of zirconia were prepared with the sol-gel method and compared as acid supports: polydispersed nanopowder (PNP), monodispersed nanopowder (MNP), and monodispersed nanoparticles coating (MNC). The size-selected zirconia-oxo-alkoxy (ZOA) nanoparticles of 3.6 nm diameter were prepared in a rapid micromixing reactor and either precipitated (MNP) or deposited on glass beads (MNC). The polydispersed 4/100/500 nm ZOA particles were prepared in nonparent alcohol for realization of PNP powders. The grafting of SO42- groups was realized on the three ZOA supports by wet impregnation method, and three catalysts were prepared after the subsequent drying and thermal treatment stages. The temperature of thermal treatment strongly affects the stability of the solid acid complex and serves to be an important factor of the preparation process. A strong retention of carbon on the surface of smallest zirconia nanoparticles induces their sintering, thus reducing the active area; therefore, the supported size-selected nanoparticles appear to be the best solution for realization of an efficient catalyst. The best acid complex stability in terms of reuse number was obtained with the thermal treatment temperature of ∼580 °C, and the specific activity (normalized on catalyst mass) of MNC catalyst toward palmitic acid conversion to methyl palmitate was found to be almost 2 orders of magnitude higher than that of PNP and MNP catalysts. [ABSTRACT FROM AUTHOR]

The principal purpose of this work is to further the understanding of the structural, electronic, and thermodynamic properties of the SrxCa1-xS alloys (0≤ x ≤1) in Rock-salt phase using the full potential augmented plane wave (FP-LAPW) method within density functional theory. The exchange-correlation potential for structural properties was calculated by the standard local density approximation (LDA) and GGA (PBE) and the new form of GGA (WC) which is an improved form of the most popular Perdew-Burke-Ernzerhof (PBE), while for electronic properties, the alternative form of GGA modified by Becke-Johnson exchange correlation potential (MBJ) was also applied. It is shown that investigation on the effect of composition on lattice constant, bulk modulus, and band gap for ternary alloys shows almost nonlinear dependence on the composition. On the other hand, the thermodynamic stability of these alloys was investigated by calculating the excess enthalpy of mixing ΔHm as well as the phase diagram. (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Structural, electronic, optical and thermodynamic properties of the SrTeO alloys (0 ≤ x ≤ 1) in rock-salt phase are calculated using the full potential-linearized augmented plane wave (FP-LAPW) method within density functional theory. The exchange-correlation potential for structural properties was calculated by the standard local density approximation (LDA) and GGA (PBE) and the new form of GGA (WC) which is an improved form of the most popular Perdew-Burke-Ernzerhof (PBE), while for electronic properties, in addition to LDA, GGA corrections; Engel-Vosko GGA (EV-GGA) and modified Becke-Johnson (mBJ) schemes were also applied. The results show that the use of GGA (WC) in our calculations is more appropriate than GGA and LDA and gives a good description of structural properties such as lattice parameters and bulk modulus. Our investigation on the effect of composition on lattice constant, bulk modulus and band gap for ternary alloys shows almost nonlinear dependence on the composition. In addition to FP-LAPW method, the composition dependence of the refractive index and the dielectric constant was studied by different models. On the other hand, the thermodynamic stability of this alloy was investigated by calculating the excess enthalpy of mixing Δ H as well as the phase diagram. [ABSTRACT FROM AUTHOR]