Synthesis of carboxylated derivatives of poly(isobutylene-co-isoprene) by azide–alkyne “click” chemistry

The final publication is available at Springer via https://dx.doi.org/10.1038/s41428-018-0130-yThe synthesis of carboxylated derivatives of poly(isobutylene-co-isoprene) (isobutylene–isoprene rubber, IIR) with substitution levels ranging from 1 to 4 mol% and different spacer lengths was accomplished through azide–alkyne Huisgen cycloaddition. Azido-functionalized IIR was first prepared by reacting brominated IIR with sodium azide to full conversion in a 90:10 tetrahydrofuran/N,N-dimethylacetamide mixture. The click reaction of azido-functionalized IIR with acetylenic acids, which was carried out using the copper(I) bromide/N,N,N′,N″,N″-pentamethyldiethylenetriamine catalyst system in tetrahydrofuran, yielded carboxylated IIRs. The products were characterized by 1H NMR and FT-IR spectroscopy, and their molecular weight was determined by size exclusion chromatography analysis. The conversion to carboxylated groups reached up to 100% as determined by NMR spectroscopy but was highly dependent on the type of solvent and the amounts of catalysts and reactants used in the procedures.ARLANXEO Canada Inc.Natural Sciences and Engineering Research Council (NSERC) of Canad

Health-Related Behaviours among Adolescents in Saudi Arabia: A Comparison Between Adolescents in Cities that Have Implemented the WHO Healthy Cities Programme and Other Cities that Have Not in the Qassim Region

There is growing evidence that morbidity and mortality in later life are linked to health risk behaviours initiated during the adolescence period. Adolescence is a critical period of peoples’ life and is influenced by physical, psychological, and emotional challenges. There is a need for a thorough understanding of adolescents’ health risk behaviours to enable behavioural modification approaches to promote healthy behaviours during this challenging period of life. This thesis presents five published manuscripts that are focused on three key health risk behaviours prevalent in Saudi Arabia, namely smoking, physical inactivity and poor dietary practices. The first two manuscripts are systematic review articles that were aimed to provide a review of the current evidence related to the prevalence and determinants of smoking, physical inactivity, and poor dietary practices among the adolescents in Saudi Arabia. In the context of this thesis, the key findings and conclusions of these systematic reviews were significant and contributed to shaping the research direction presented in later chapters. These systematic review chapters are followed by three original research articles that were aimed to investigate the prevalence and determinants of smoking, insufficient physical activity and poor dietary practice among the adolescents and compare these behaviours between the cities which has implemented the World Health Organization’s (WHO) Healthy Cities Programme (HCP) and the cities which has not implemented such programme in the Qassim region, Saudi Arabia, respectively. Using multi-stage cluster sampling with probability proportionate to size, I surveyed 1133 school-going adolescents from three HCP cities and three NHCP cities in the Qassim region, Saudi Arabia, between April and September 2017. Multivariable logistic regression analyses were conducted to investigate the predictors of insufficient levels of PA and excessive screen time. The prevalence of smoking among school-going adolescents in the Qassim region was 5.2%. Among the socio-demographic variables, smoking was significantly associated with gender, age, and academic performance. The prevalence of smoking among the adolescents was significantly higher in HCP cities than in NHCP cities. The prevalence o

COVID-19 vaccination intent and willingness to pay in Bangladesh:a cross-sectional study

Abstract This article reports the intent to receive a SARS-COV-2 vaccine, its predictors and willingness to pay in Bangladesh. We carried out an online cross-sectional survey of 697 adults from the general population of Bangladesh in January 2021. A structured questionnaire was used to assess vaccination intent. The questionnaire included sociodemographic variables and health belief model constructs which may predict vaccination intent. Among the participants, 26% demonstrated a definite intent, 43% probable intent, 24% probable negative, and 7% a definite negative intention. Multivariable logistic regression analyses suggest an association between definite intent and previous COVID-19 infection (OR: 2.86; 95% CI: 1.71–4.78), perceiving COVID-19 as serious (OR: 1.93; 1.04–3.59), the belief that vaccination would make them feel less worried about catching COVID-19 (OR: 4.42; 2.25–8.68), and concerns about vaccine affordability (OR: 1.51; 1.01–2.25). Individuals afraid of the side effects (OR: 0.34; 0.21–0.53) and those who would take the vaccine if the vaccine were taken by many others (OR: 0.44; 0.29–0.67) are less likely to have a definite intent. A definite negative intent is associated with the concern that the vaccine may not be halal (OR: 2.03; 1.04–3.96). Furthermore, 68.4% are willing to pay for the vaccine. The median amount that they are willing to pay is USD 7.08. The study findings reveal that the definite intent to receive the SARS-CoV-2 vaccination among the general population varies depending on their COVID-19-related health beliefs and no significant association was found with sociodemographic variables

Depression among the non-native international undergraduate students studying dentistry in Bangladesh

Abstract Background: Bangladesh has been attracting international students with interests in various subjects recently. Every year students from different parts of the world come to study undergraduate and postgraduate courses, mostly at private universities in Bangladesh. This study evaluates the depression status among international students who are studying dentistry in Bangladesh. Methods: This cross-sectional survey was conducted among International undergraduate dental students who enrolled in the Bachelor of Dental Surgery program in nine public and private dental colleges in Bangladesh. Participants were selected using a convenience sampling method. A total of 206 students completed the survey where 78.5% of them were female students and 21.5% students were male, and a CES-D 10-item Likert scale questionnaire was used for data collection. The Cronbach alpha for the 10-item CES-D scale for this population is 0.812. Results: The majority of the students (79.5%) are below 24 years of age with a mean age of 23.22 years and standard deviation of 2.3, and are students who cannot communicate well in Bengali (Bangla), about 60% of them have experienced depression. About 77.3% (p < 0.00) of the international students having financial difficulties exhibited depression. The international students who went through financial problems were two times more likely to suffer from depression (OR = 2.38; p-value < 0.01). Conclusion: This study tried to highlight the struggles faced by international students in Bangladesh studying dentistry. It is evident from the findings that several factors influence students’ mental well-being during demanding dental education years