Electrical and Magnetic Properties of Mn-Bi-Sb Alloys

MnBi1-xSbx alloys were prepared by the conventional melt technique. The Seebeck coefficient (S), electrical resistivity (ρ), and magnetic susceptibility (c) were measured at various temperatures ranging from ~100 to 400 K. The electrical resistivity of x £ 0.15 shows both semiconducting and metallic behavior depending on temperature and Sb content, whereas samples x 3 0.2 have only semiconductor behavior in all the temperature range. The negative sign of the Seebeck coefficient increases, i.e., the positivity decreases with the increasing Sb content. The magnetic susceptibility (χ) shows that alloys undergo ferro-paramagnetic transition at a certain temperature (TC) and the TC values decrease with increasing Sb content. From thermoelectric measurements and electronic thermal conductivity calculated, it was observed that Sb doping increases the power factor (PF) and the figure of merit (ZT). Thus, Sb content plays an essential role in making these alloys applicable in the thermoelectric industry

Using the theoretical domains framework to investigate clinicians’ behavioural determinants of antimicrobial prescribing in Qatar.

Introduction: A recent systematic review by Talkhan et al demonstrated the need for theoretically based behaviour change interventions in this area. [1] For development of such complex interventions, emphasis should be placed on using theory to systematically identify behavioural determinants of antimicrobial prescribing. Aim: To identify and quantify clinicians’ behavioural determinants of antimicrobial prescribing in Qatar. Methods: This cross-sectional survey is part of a multi-phase explanatory, sequential mixed methods PhD project in Qatar. Questionnaires were distributed (online and paper based) to all doctors (~4,000) and pharmacists (~400) within Hamad Medical Corporation (HMC, the main healthcare provider). The questionnaire was developed with reference to the Determinants of Implementation Behaviour Questionnaire (a generic questionnaire derived from the 14 theoretical domains of the Theoretical Domains Framework, TDF). [2] Each item was presented as a 5-point Likert scale (scored 5=Strongly agree to 1=Strongly disagree). Personal and practice demographics were also collected for data contextualisation. The draft questionnaire was reviewed for face/content validity by an expert panel of six researchers in Qatar and the UK with experience in the use of the TDF, followed by ‘Think aloud’ testing and piloting. Analysis investigated the behavioural determinants and influential factors through descriptive, principal component analysis (PCA) and inferential analysis. Ethics approval was granted from a UK university and HMC. Results: In total, 535 responses were received, 339 (63.4%) from doctors and 196 (36.6%) from pharmacists. Respondents were predominantly male, 346 (64.7%). Just over half (n=285, 53.3%) had ≤ 5 years’ experience as health professionals. PCA showed a three component (C) solution with components incorporating a number of questionnaire items labelled: ‘Guidelines compliance’ (C1 with 8 items), ‘Influences on prescribing’ (C2 with 7 items) and ‘Self-efficacy’ (C3 with 5 items) in prescribing/recommendation activity. A scale score for each respondent was calculated through summation of Likert scores for the relevant questionnaire items within each component. These scales had high internal reliability (Cronbach’s alpha all >0.7) showing consistency in response between component items indicating statistical appropriateness for developing scales. The median score (possible scale range, midpoint) for each scale was C1, 32 (8 to 40, 24), C2, 26 (7 to 35, 21) and C3, 20, (5 to 25, 15). By way of example Table 1 shows levels of agreement for items in C2. This shows lower levels of agreement than C1 scale with the median scale score (26) closer to the midpoint (21) indicating that respondents had less positive views. Inferential analysis using these scale scores and free text analysis is in progress. Conclusion: A theoretical basis was used throughout providing insights to behavioural determinants for the development of a theory-based behaviour change intervention. Preliminary results suggest that social influences, staff development and quality monitoring may be useful targets for behaviour change interventions to improve antimicrobial prescribing practice. Limitations include potential social desirability bias and focus on one healthcare organisation/country in the Middle East which may limit generalisability of findings. More in-depth exploration is required to select and test appropriate linked theory-based behaviour change techniques

Gamma-Irradiation Improves the Photocatalytic Activity of Fe/TiO2 for Photocatalytic Degradation of 2-Chlorophenol

The Fe doped TiO2 abbreviated here as (Fe3) were prepared by sol-gel method. Upon doping FeTiO3 nano-composite was formed. The prepared sample was irradiated by different dosage of γ-irradiated (0.2, 0.4, 0.8 and 1.6 MGy).  The irradiated samples which abbreviated as (0.2, 0.4, 0.8 and 1.6 MGy) and non-irradiated sample which abbreviated as (Fe3)  were characterized by X-Ray Diffraction (XRD), Surface analysis, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Temperature Programmed Desorption (NH3-TPD), Raman Spectroscopy,  and UV-Vis absorption. The results show that γ-irradiation not only improves the morphological and structural changes of irritated samples, but also extended its absorption edge to the visible light region. The photocatalytic activity of the samples were tested for the photocatalytic degradation of   2-chlorophenol under simulated solar light irradiation. The photocatalytic activity of the irradiated sample using 1.6 MGY was higher than the other irradiated and non-irradiated samples. The photo-intermediate product was also studied. Keywords: Photocatalysis, TiO2, 2-chlorophenol, photocatalytic degradation, Gamma-irradiation

Five-Year Experience In Surgical Treatment Of Temporal Bone Paragangliomas

The article describes our five-year experience in the surgical treatment of temporal bone paragangliomas. Considering our experience, the surgical treatment of patients with different types of paragangliomas based on a detailed study of the CT scan and MRI data using the preoperative selective embolization of tumor-feeding vessels and the navigation system intraoperatively as well as the endoscopy assistance allows total removing of the tumor with minimal damaging of the vital structures of the lateral skull base

Genotype and Haplotype Analysis of ABCB1 at 1236, 2677 and 3435 among Jordanian Population

Purpose: To determine the frequencies of important allelic variants and their haplotype frequencies of the gene among Jordanian population and to compare findings with those reported for other ethnic groups.Methods: Genotyping of ABCB1 (C1236T, G2677T/A and C3435T) was carried out on unrelated healthy Jordanian subjects. Different allelic variants were determined using polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP). The haplotype frequencies of these three SNPs were analyzed and compared them with those of other reported populations. Haplotype frequencies were calculated using Golden Helix Tree software and Linkage disequilibrium was represented by D”.Results: ABCB1 C3435T allele frequencies for C allele and T allele were 0.57 and 0.43, respectively. For ABCB1 G2677T/A the allele frequencies for G allele, T allele, and A allele were 0.65, 0.32 and 0.0, respectively. As for ABCB C1236T, its allele frequencies were 0.65 for C allele and 0.35 for T allele. C1236T, G2677T/A, and C3435T SNPs were expected to be structured in 8 different haplotypes with GC- C (37.6.0 %), T-T-T (18.6 %), G-C-T (14.3 %) and T-T-C (12 %) that were most prominent. The haplotype frequency distribution of our study group was found to be significantly different from those of Chinese, Indian, Japanese, African and Caucasian (p < 0.0001) and resemble Ashkenazi Jewish and Slovenian populations (p > 0.05).Conclusion: In addition to earlier studies, the findings of the current study provide evidence that suggest the use of genetic polymorphisms of ABCB1 SNPs as markers for ethnicity and ancestral origin. The analysis of haplotype and genotype can be useful in identifying the relation between ABCB1 polymorphism, disease susceptibility and drug disposition.Keywords: Genotype, Allele, MDR1, ABCB1, Polymorphism, Haplotype frequencie

STEPS TOWARD OPTIMIZING HPGe DETECTOR EFFICIENCY IN THE CONTEXT OF LOW-LEVEL RADIOACTIVITY DETECTION

Different empirical and theoretical methods are used to precisely determine radionuclide activity concentrations. This study used Monte Carlo simulation MCNP5 code and EFFTRAN software (Efficiency Transfer) to determine the HPGe detector Full-Energy Peak (FEP) efficiency. A set of point sources (133Ba,152Eu,137Cs,60Co, and22Na) fixed on the top of the standard geometry plastic container were measured in order to obtain the calibration curve. Because of the importance of chemical composition parameters, the detector behavior due to different matrices was investigated. Experimental verification of the calibration was obtained using IAEA-TEL-2021-03 quality control water sample spiked with152Eu and133Ba, and the results were compared with reported results. A set of Certified Standard Reference samples were used for method validation. The obtained results were compared with the experimental results. The comparison clarified the advantages and disadvantages of both methods and their precision to demonstrate and suitable method for matrix types. © 2023, Publishing House of the Romanian Academy. All rights reserved