Enhanced Trapezoidal Modulation in MMC: Comparative Analysis with Traditional Modulation Methods

HVDC transmission and renewable energy systems extensively use Modular Multilevel Converters (MMC) because they provide outstanding scalability and modular architectural features. The performance quality of MMCs depends predominantly on which modulation technique engineers implement. This work studies Nearest Level Modulation (NLM) and conventional Trapezoidal Modulation alongside an enhanced Trapezoidal Modulation method to identify the top choice for high-voltage power implementations. The main goal of this research is to optimize modulation techniques for improving MMC harmonic performance and switching efficiency. Each modulation strategy is simulated through MATLAB/Simulink-based testing under identical operating situations. Product testing indicates NLM shows lower switching losses as well as superior power distribution efficiency but the updated Trapezoidal Modulation design combines reduced THD performance with simple implementation methods. The method\u27s innovative aspect depends on the modified trapezoidal waveform synthesis from a fundamental-frequency triangular signal enabling simplified implementation as well as lower THD and avoiding the need for high switching frequencies used in conventional approaches.  The research delivers critical knowledge about MMC modulation selection which systems designers and manufacturers can use to optimize converter operation based on specific applications

Enhanced Trapezoidal Modulation in MMC: Comparative Analysis with Traditional Modulation Methods

HVDC transmission and renewable energy systems extensively use Modular Multilevel Converters (MMC) because they provide outstanding scalability and modular architectural features. The performance quality of MMCs depends predominantly on which modulation technique engineers implement. This work studies Nearest Level Modulation (NLM) and conventional Trapezoidal Modulation alongside an enhanced Trapezoidal Modulation method to identify the top choice for high-voltage power implementations. The main goal of this research is to optimize modulation techniques for improving MMC harmonic performance and switching efficiency. Each modulation strategy is simulated through MATLAB/Simulink-based testing under identical operating situations. Product testing indicates NLM shows lower switching losses as well as superior power distribution efficiency but the updated Trapezoidal Modulation design combines reduced THD performance with simple implementation methods. The method\u27s innovative aspect depends on the modified trapezoidal waveform synthesis from a fundamental-frequency triangular signal enabling simplified implementation as well as lower THD and avoiding the need for high switching frequencies used in conventional approaches.  The research delivers critical knowledge about MMC modulation selection which systems designers and manufacturers can use to optimize converter operation based on specific applications

Dundee Ready Educational Environment Measure Tool for Evaluating the Educational Environment: A Systematic Review and Meta-analysis

OBJECTIVE: The purpose of this systematic review was to study the literature evaluating the educational environment by using DREEM tool and compute overall mean DREEM score by using Meta-analysis. Further, variation in DREEM score was also studied by distributing studies into different time periods. MATERIALS AND METHODS: A systematic literature search was performed using PubMed and Web of Science databases, followed by review and analysis. All the studies which used DREEM as a tool, published from 1997 to December 2015 were included. Heterogeneity between the studies was assessed by I2-coefficient and Q-statistics. Where significant heterogeneity existed random effect, model was used. Egger’s symmetric test and Begg’s funnel plot was used to study possibility of publication bias. The PRISMA Guideline for systematics review was used. RESULTS: Out of 128 published DREEM studies, 43 passed the criteria and included in analysis. Overall mean DREEM score through Meta-analysis was 2.426 (95% confidence interval [CI]: 2.34-2.52). Studies were divided into two groups for analyzing the time effect. Mean score of the studies published during 1997 to 2009 (group 1) was 2.5 (95% confidence interval [CI]: 2.35-2.64) and for the studies from 2010 to 2015 (group 2) was 2.39 (95% confidence interval [CI]: 2.29-2.5). CONCLUSION: Overall DREEM score was more towards positive side than negative. Current review revealed that DREEM has not been used as predictor for achievement of any medical college instead it can be used to predict high and low achievers in a medical school. This review can signify DREEM to be suitable and consistent tool showing learning environment of institute and student’s prerequisites

Prevalence, Comparison, and Determinants of Smoking among Young Schoolchildren in Kingdom of Saudi Arabia

BACKGROUND: Smoking is one of the most serious health issues among all age groups, particularly in children globally including the Gulf region. However, there are little data about the prevalence in public and private schools and determinants of smoking among adolescents in Saudi Arabia. AIM: The purpose of this study was to estimate the prevalence, compare, and determine smoking habits among male children in public and private schools. METHOD: This cross-sectional study was conducted in Dammam city, KSA. The data were collected from 866 male children studying in public and private schools. Sample was calculated through stratified random sampling. The modified “Global Youth Tobacco Survey (GYTS)” was used to collect information. RESULTS: The total number of children recruited was 866 (223 from private and 643 from public schools). The mean age of children studied was 14.20 ± 1.03 years in both groups. The result shows that overall 27.8% of children tried to smoke cigarette both in public and private schools. The prevalence of smoking is higher in public schools’ children than in private schools (30% vs. 21%; p = 0.005). In addition, wrong perception of comfortable feeling after smoking, easy access to cigarettes, parent’s addiction, and smoking in front of children are the determining factors. CONCLUSION: This study suggests that the prevalence of cigarettes smoking among children exists in considerable proportion. It is higher in public schools children. The health and education authorities should take urgent steps to encounter this major health issue

A scoping review on the obstacles faced by beta thalassemia major patients in Pakistan- Matter of policy investment

Beta-thalassemia major (β-TM) is a genetic disorder, prevalent especially in the Mediterranean region, Southeast Asia, and the Indian subcontinent. With improvements in management over the years, β-TM has transitioned from a fatal childhood disease to a chronic condition. However, in Pakistan, there is still a lack of a comprehensive national policy and strategic plan, which has resulted in a growing number of β-TM patients, placing a substantial burden on individuals and the national healthcare system. This scoping review is aimed to understand obstacles faced by β-TM patients in Pakistan. For this review, 26 unique articles were identified by using the PRISMA flow guidelines. PubMed and Google Scholar were used with the MESH term Beta-Thalassemia Major AND Pakistan, and the duration was set between 2012–2022. Then, the reviewers created a spreadsheet using Microsoft Excel to add in the data from the studies selected. Inductive and deductive approaches were used for thematic analysis. Additionally, we critically analyzed the current landscape of β-TM in Pakistan. The main challenges in β-TM care in Pakistan are suboptimal transfusion services and a poor complication management. Due to the need of chronic blood transfusions, transfusion-transmitted infection (TTI) incidence within this patient population is high. These largely include hepatitis C, hepatitis B, and the Human immunodeficiency virus (HIV). TTIs impact the quality of life of these patients and their overall survival. Furthermore, psychosocial morbidities are also prevalent in β-TM patients, with increased levels of hostility, anxiety, and depressive symptoms, thus emphasizing the critical need for sustained psychological support. Access to quality treatments is constrained, with notable disparities between public and private sector hospitals. Additionally, the financial burden on β-TM patients is considerable, which contributes to economic strain and more hardships on the already suffering families. The review concludes that the absence of a unified national policy exacerbates these challenges, which results in an escalating burden of β-TM nationwide. To address these issues, essential recommendations include the following: the implementation of a standardized protocol for β-TM care, the enhancement of access to quality care, the provision of iron chelation therapy, and safeguarding safe blood transfusion practices. Prevention programs, along with increased public awareness and education about β-TM and carrier screening, are pivotal. Collaborative efforts with international partners and drawing insights from successful strategies in countries with similar β-TM burdens can aid in mitigating the overall impact of β-TM in Pakistan and improving the quality of life of the affected individuals

Prenatal Diagnosis of Maternal Serum from Mothers Carrying β-thalassemic Fetus

Background Current study focused on discovering protein biomarkers from the maternal serum of β-thalassemic trait mothers carrying the normal fetus and β-thalassemic major fetus. Method Serum samples from β-thalassemic trait mothers carrying major (N=5) and normal fetuses (N=5) were studied. IVS1-5 thalassemia mutation was common among β-thalassemic trait mothers who were carrying homozygous β-thalassemic fetus (IVS1-5/ IVS1-5 mutation) or normal fetus (no mutation). We employed two-dimensional gel electrophoresis and mass spectrometric analysis to explore differentially expressed maternal serum proteins from thalassemia carrier couples having the same β-thalassemia mutation. Western blotting was performed for one of the identified proteins to validate our data. Results Ten proteins were identified in maternal serum of β-thalassemic trait mothers carrying the β-thalassemic major fetus and normal fetus. Among these, Serotransferrin, Haptoglobin, Alpha-1 anti-trypsin (A1AT), Apo-lipoprotein A1, and Fibrinogen-beta chain were found to be up-regulated in mothers carrying major fetuses and are known to be associated with pregnancy-related disorders. The expression of A1AT was validated through western blotting. Conclusion Proteins identified in the current study from maternal serum are reported to contribute to hereditary disorders. We suggest that these can serve as putative screening markers for non-invasive prenatal diagnosis in β-thalassemic pregnancies

A large, locally aggressive giant cell tumour arising from the laryngeal cartilage: A Rare Case Report

Giant cell tumour is a growth predominantly found in long bones of the body. Giant cell tumour has a rare occurrence in the head and neck. A case of a 31 year old male with no known comorbidities at the ENT Department, Shifa International Hospital, Islamabad presented with anterior neck swelling and hoarseness of voice. Patient was diagnosed as having Giant Cell Tumour of Larynx (GTCL) proven on FNA cytology and post-operative biopsy. GCTL is an uncommon entity with only 45 reported cases in the world. Key Words: Giant Cell Tumor, Laryngeal Cancer, Thyroid Cartilage, Laryngectomy

General public awareness, knowledge and attitude toward COVID-19 infection and prevention: a cross-sectional study from Pakistan [version 2; peer review: 2 approved]

Background: The aim of this study is to evaluate the knowledge, perceptions, and attitude of the public in Pakistan (using social media) towards COVID-19. Methods: A cross-sectional study was conducted amongst 1120 individuals nationwide. A self-developed, pre-tested questionnaire was used that comprised of sections covering demographic characteristics, medical history, hygiene awareness, COVID-19-related knowledge, and learning attitude. Descriptive statistics were used for frequencies, percentages, averages and standard deviations. Inferential statistics were done using the Student’s t-test and ANOVA. Results: The average age of participants was 31 years (range 18-60 years). In total 56 individuals (5%) had completed primary or secondary school education; 448 (40%) were employed (working from home) and 60% were jobless due to the COVID-19 crisis. Almost all the study subjects (1030 (92%)) were washing their hands multiple times a day. A total of 83% had awareness regarding quarantine time, 82% used face masks whenever they left their homes, 98% were aware of the origin of the disease, and 70% had knowledge regarding the most common symptoms of COVID-19. Conclusion: It can be concluded from the current study that female participants had higher level of education, and more awareness regarding the coronavirus. The majority of the participants followed proper hand washing regimes and washed their faces. Further knowledge and awareness should be promoted