RESUMEN
Heusler alloys have drawn the interest of researchers due to their possible technical significances and multifunctional use. Herein, a thorough theoretical analysis using "density functional theory (DFT)" is performed to investigate the general physical features of RbTaSi and RbTaGe alloys. The "generalised gradient approximation (GGA)" and "Tran-Blaha modified Becke-Johnson (TB-mBJ) potential" has been incorporated to model the electronic structures of RbTaSi and RbTaGe. The structural optimization results signify that these materials are stable in the ferromagnetic phase with a cubic F4Ì3m structure, which is supported by the computed elastic parameters. In addition, cohesive energy and microhardness signify strong bonding. The spin-polarisation bands and density of states indicate the half-metallic nature of these materials. These materials have spin magnetic moment 2µB, thereby emphasizing the use of these alloys for spintronic applications. Transport and thermodynamic properties have been calculated, and their temperature dependence is illustrated. The behavior of transport coefficients with temperature futher implies the presence of half-metallic nature.
RESUMEN
Listeria monocytogenes, a facultative intracellular gram-positive pathogen, is the causative agent of the disease listeriosis. The virulence of this intracellular bacterium is dependent on the coordinated activity of various bacterial factors, which are in turn tightly controlled by a specific set of regulators. The various virulence factors employed by L. monocytogenes for its infection cycle are well reported in literature. Although the internalins of L. monocytogenes have been studied in detail, their structural details are currently scattered and fragmented. Therefore, in the current review, we provide a brief account of the existing knowledge on structural details of the key internalins of L. monocytogenes and also highlight the recent advances in their functional aspects.
Asunto(s)
Proteínas Bacterianas , Listeria monocytogenes/química , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Listeria monocytogenes/metabolismoRESUMEN
Despite the high prevalence of hemoglobinopathies in Saudi Arabia, the prevalence data in some regions are lacking. Updating the epidemiological survey of hemoglobinopathies at regular intervals is necessary to develop effective prevention and control strategies. Therefore, the primary aim of this study was to determine the prevalence of selected hemoglobinopathies in Saudi adults attending premarital screening at the King Khaled General Hospital (KKGH), Al Majma'ah, Saudi Arabia. The current retrospective study was approved by the Central Institutional Review Board (IRB) of the Ministry of Health (with central IRB log #2019-0039E) and was carried out at the above hospital. The data of the premarital couples, who attended the premarital screening center at KKGH from 1 October 2016 to 30 September 2019, was included in this study. A cation exchange high performance liquid chromatography (HPLC) system was used for screening of the selected hemoglobinopathies. In total, 3755 cases including 1953 (52.01%) males and 1802 (47.99%) females, were screened for hemoglobinopathies. Abnormal hemoglobin (Hb) fractions were observed in 38 (1.01%) cases. The prevalence of ß-thalassemia (ß-thal) trait was 0.69% (26/3755) and that of sickle cell trait 0.32% (12/3755). Our results showed that the prevalence of ß-thal trait is higher than that of sickle cell trait in the adult population of Al Majma'ah. Further comprehensive programs should be carried out to determine the prevalence of hemoglobinopathies in various provinces and cities of Saudi Arabia and other countries. This will help to maintain the updated records of the disease incidence for improving the control measures.