Simulation of Electromagnetic Coupling on Pipelines close to Overhead Transmission Lines: A Parametric Study

Electromagnetic interference effects caused by electric power lines on neighboring metallic utilities such as water, gas or oil pipelines became a major concern due to significant increase in the load and short circuit current levels needed to satisfy the load requirements. Another reason for increased interference levels originates from the environmental concerns, which impose on various utilities the obligation to share common corridors. This paper presents three different scenarios of a pipeline in which all types of electromagnetic interferences (coupling) will be investigated and their effects on the pipeline will be predicted. The level of the calculated voltage, owing to each type of coupling, depends on different factors (voltage level, length of parallelism, separation distance, soil resistivity, load current magnitude and pipeline coating). The effects of these factors are discussed; some factors such as the fault current level, separation distance and soil resistivities are found to exhibit a large influence on the pipeline voltage. To the best of the authors’ knowledge, the comprehensive analyses presented in this paper considering all types of interferences have not yet been published elsewhere

Design and Economic Analysis of a Grid-connected Rooftop Solar PV System for Typical Home Applications in Oman

This paper presents a techno-economic investigation of an integrated rooftop solar PV system for typical home applications in Oman that can reduce the power consumption from the grid and export excess PV generated power back to the gird. Since renewable energy systems design echnically depends on the site, this study selects a typical two-story villa (Home), in a site Al-Hamra, Oman. Temperature is one of the critical parameters in this design as it varies widely over the day and from one season to another in Oman. With the effect of temperature variation, the PV system has designed using system models for the required load of the home. The design process has included two main design constraints, such as the available rooftop space and the grid-connection availability for the selected home.This research also evaluates the economic feasibility of the design system considering the energy export tariff as per the Bulk Supply Tariff (BST) scheme in Oman. The design outcome reveals that the designed PV system can supply the load energy requirement in a year. In addition, the rooftop solar PV system can sell surplus energy back to the grid that generates additional revenue for the owner of the system. The economic performance indices such as payback period, internal rate of return, net present value,and profitability index ensure the financial feasibility of the designed rooftop solar PV system for the selected home.

A novel mutation in HSD11B2 causes apparent mineralocorticoid excess in an Omani kindred

Apparent mineralocorticoid excess (AME) is a rare autosomal recessive genetic disorder causing severe hypertension in childhood due to a deficiency of 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2), which is encoded by HSD11B2. Without treatment, chronic hypertension leads to early development of end-organ damage. Approximately 40 causative mutations in HSD11B2 have been identified in ∼100 AME patients worldwide. We have studied the clinical presentation, biochemical parameters, and molecular genetics in six patients from a consanguineous Omani family with AME. DNA sequence analysis of affected members of this family revealed homozygous c.799A>G mutations within exon 4 of HSD11B2, corresponding to a p.T267A mutation of 11βHSD2. The structural change and predicted consequences owing to the p.T267A mutation have been modeled in silico. We conclude that this novel mutation is responsible for AME in this family

Mobile applications in government services (mG-App) from user's perspectives: A predictive modelling approach

YesMobile applications are becoming a preferred delivery method for the government sector and contributing to more convenient and timely services to citizens. This study examines the intention to use mobile applications for the government services (mG-App) in Oman. This study extended the Unified Theory of Acceptance and Use of Technology (UTAUT) model by including two constructs namely trust and information quality. Data were collected from 513 mobile application users across Oman. The research model was analysed in two stages. First, structural equation modelling (SEM) was employed to determine significant determinants affecting users’ acceptance of mG-App. In the second stage, a neural network model was used to validate SEM results and determine the relative importance of determinants of acceptance of mG-App. The findings revealed that trust and performance expectancy are the strongest determinants influencing the acceptance of mG-App. The findings of this research have provided theoretical contributions to the existing research on mG-App and practical implications to decision-makers involved in the development and implementation of mG-App in in Oman

The association of Human Leukocyte Antigens Complex with Type 1 Diabetes in Omanis

Background: Identifying the human leukocyte antigens (HLA) high risk alleles, genotypes and haplotypes in different populations is beneficial for understanding their roles in type 1 diabetes (T1D) pathogenesis and intervention practices. Objective: The aim of this study was to identify T1D associated HLA gene alleles in the Omani population. Methods: Our case-control study included 73 diabetic seropositive children (mean age 9.08±3.27 years) and 110 healthy controls. HLA–A, -B, -C, -DRB1, and -DQB1 genes were genotyped using sequence specific primer polymerase chain reaction (SSP-PCR). Results: Two HLA class I alleles (B*08, B*58) and three class II alleles (DQB1*02, DRB1*03 and DRB1*04) were associated with T1D susceptibility, while one class I (B*51) and three class II (DQB1*05, DQB1*06, and DRB1*16) alleles were associated with T1D protection. HLA- DRB1*03 and DQB1*02 alleles showed the strongest risk association among all alleles. Six DRB1 residues (E9, S11, S13, Y30, V70 and K71) were significantly associated with T1D susceptibility. Heterozygous genotypes, HLA-DRB1*03/*04 and DQB1*02/*03 were significantly associated with T1D susceptibility (P=4.29E-07, OR=63.2 and P=0.02, OR=3.6, respectively). Furthermore, we detected a significant combined action of DRB1*03-DQB1*02 haplotype in T1D risk (P=1.76E-05, OR=15), and DRB1*16-DQB1*05 haplotype in protection (P=3.12E-2, OR=0.48). Conclusion: Known HLA class II gene alleles are associated with T1D in Omani children

Neoadjuvant Chemotherapy Alters Neuropilin-1, PlGF, and SNAI1 Expression Levels and Predicts Breast Cancer Patients Response

Circulating proteins hold a potential benefit as biomarkers for precision medicine. Previously, we showed that systemic levels of neuropilin-1 (NRP-1) and its associated molecules correlated with poor-prognosis breast cancer. To further identify the role of NRP-1 and its interacting molecules in correspondence with patients' response to neoadjuvant chemotherapy (NAC), we conducted a comparative study on blood and tissue samples collected from a cohort of locally advanced breast cancer patients, before and after neoadjuvant chemotherapy (NAC). From a panel of tested proteins and genes, we found that the levels of plasma NRP-1, placenta growth factor (PlGF) and immune cell expression of the transcription factor SNAI1 before and after NAC were significantly different. Paired t-test analysis of 22 locally advanced breast cancer patients showed that plasma NRP-1 levels were increased significantly (p = 0.018) post-NAC in patients with pathological partial response (pPR). Kaplan–Meier analysis indicated that patients who received NAC cycles and their excised tumors remained with high levels of NRP-1 had a lower overall survival compared with patients whose tissue NRP-1 decreased post-NAC (log-rank p = 0.049). In vitro validation of the former result showed an increase in the secreted and cellular NRP-1 levels in resistant MDA-MB-231 cells to the most common NAC regimen Adriyamicin/cyclophosphamide+Paclitaxel (AC+PAC). In addition, NRP-1 knockdown in MDA-MB-231 cells sensitized the cells to AC and more profoundly to PAC treatment and the cells sensitivity was proportional to the expressed levels of NRP-1. Unlike NRP-1, circulating PlGF was significantly increased (p = 0.014) in patients with a pathological complete response (pCR). SNAI1 expression in immune cells showed a significant increase (p = 0.018) in patients with pCR, consistent with its posited protective role. We conclude that increased plasma and tissue NRP-1 post-NAC correlate with pPR and shorter overall survival, respectively. These observations support the need to consider anti-NRP-1 as a potential targeted therapy for breast cancer patients who are identified with high NRP-1 levels. Meanwhile, the increase in both PlGF and SNAI1 in pCR patients potentially suggests their antitumorigenic role in breast cancer that paves the way for further mechanistic investigation to validate their role as potential predictive markers for pCR in breast cancer

The Impact of Polymer Electrolyte Properties on Lithium-Ion Batteries

In recent decades, the enhancement of the properties of electrolytes and electrodes resulted in the development of efficient electrochemical energy storage devices. We herein reported the impact of the different polymer electrolytes in terms of physicochemical, thermal, electrical, and mechanical properties of lithium-ion batteries (LIBs). Since LIBs use many groups of electrolytes, such as liquid electrolytes, quasi-solid electrolytes, and solid electrolytes, the efficiency of the full device relies on the type of electrolyte used. A good electrolyte is the one that, when used in Li-ion batteries, exhibits high Li+ diffusion between electrodes, the lowest resistance during cycling at the interfaces, a high capacity of retention, a very good cycle-life, high thermal stability, high specific capacitance, and high energy density. The impact of various polymer electrolytes and their components has been reported in this work, which helps to understand their effect on battery performance. Although, single-electrolyte material cannot be sufficient to fulfill the requirements of a good LIB. This review is aimed to lead toward an appropriate choice of polymer electrolyte for LIBs

COVID-19 Disease Severity in Persons Infected with Omicron BA.1 and BA.2 Sublineages and Association with Vaccination Status

[No abstract available

Outcomes Among Patients with Breakthrough SARS-CoV-2 Infection After Vaccination.

BACKGROUND: Breakthrough infections after SARS-CoV-2 vaccination have been reported. Clinical outcomes in these persons are not widely known. METHODS: We evaluated all vaccinated persons with breakthrough infection ≥14 days after the second vaccine dose and unvaccinated controls matched on age, sex, nationality, and reason for testing between December 23, 2020 and March 28, 2021 in Qatar. Our primary outcome was severe disease defined as hospitalization, mechanical ventilation, or death. RESULTS: Among 456 persons cases of breakthrough infection and 456 unvaccinated matched controls with confirmed infection, median age was 45 years, 60.7% were males, and ≥1 comorbid condition was present in 61.2% of the vaccinated and 47.8% of the unvaccinated persons (P=0.009). Severe disease was recorded in 48 (10.5%) of the vaccinated and 121 (26.5%) of the unvaccinated group (P40-60 years, HR 2.32; >60-70 years, HR 4.34; >70 years, HR 5.43); presence of symptoms at baseline (HR 2.42, 95%CI 1.44-4.07); and being unvaccinated (HR 2.84, 95%CI 1.80-4.47). CONCLUSIONS: In persons with breakthrough SARS-CoV-2 infection, increasing age is associated with a higher risk of severe disease or death, while vaccination is associated with a lower risk. Presence of comorbidities was not associated with severe disease or death among persons with breakthrough infection