RESUMO
Tobacco use is increasing among young people, especially in Gulf nations such as Saudi Arabia. The objectives of this study were to estimate the prevalence and behavioural patterns of tobacco use among undergraduate students at King Saud University, Riyadh, Saudi Arabia during the academic year 2008/09 and investigate factors that influenced their tobacco use. A cross-sectional study was done of a representative sample (n = 6793) of the undergraduate student population using a modified version of the global youth tobacco survey questionnaire. The prevalence of smoking was 14.5% among students, 22.2% and 2.2% among fathers and mothers and 43.1% and 14.8% for male and female siblings; 15.0% reported all or most of their friends smoked. The most important independent predictors of smoking were: friends' smoking (some: OR = 6.7 and all: OR = 54.9), sister's smoking (OR = 2.2), mother's smoking (OR = 2.1), single status (OR = 1.7) and age (OR = 1.18).
Assuntos
Fumar/epidemiologia , Estudantes/estatística & dados numéricos , Universidades , Adolescente , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pais , Prevalência , Fatores de Risco , Arábia Saudita/epidemiologia , Irmãos , Inquéritos e QuestionáriosRESUMO
Pretreatment of biosorbents have been suggested to modify the surface characteristics which could improve biosorption process. Stable cesium biosorption was studied in continuous fixed-bed column by chemically modified biosorbents. Two kinds of brown algae (Sargassum glaucescens and Cystoseira indica) were treated with chemical agents including formaldehyde (FA), glutaraldehyde (GA), potassium hexacyanoferrate (HCF), FA and HCF, and GA and HCF. The highest biosorption capacity (BC) was obtained from C. indica treated with FA (63.5 mg Cs/g biomass) and S. glaucescens treated with FA and HCF (62 mg Cs/g biomass). To study the effect of the best treatments on the BC, the concentration of each treatment agent was decreased. With decreasing FA agent for C. indica treatment, the BC dropped. Treatment of 1g S. glaucescens biomass with 2.2g FA and then 0.18 g HCF resulted in the highest BC (73.08 mg Cs/g dry biomass) which was 35.8 times higher than intact S. glaucescens.
Assuntos
Biomassa , Césio/química , Phaeophyceae/química , Sargassum/química , Absorção , Reagentes de Ligações Cruzadas , Ferrocianetos/química , Formaldeído/química , CinéticaAssuntos
Cryptococcus/metabolismo , Temperatura , Monofosfato de Adenosina/biossíntese , Radioisótopos de Carbono , Parede Celular/enzimologia , Parede Celular/metabolismo , Sistema Livre de Células , Cromatografia em Papel , Cryptococcus/enzimologia , Cryptococcus/crescimento & desenvolvimento , Etilmaleimida/metabolismo , Glutationa Redutase/metabolismo , Glicosídeo Hidrolases/metabolismo , Polissacarídeos , Espectrofotometria Ultravioleta , Nucleotídeos de Uracila/biossíntese , Açúcares de Uridina Difosfato/biossínteseAssuntos
Cryptococcus/crescimento & desenvolvimento , Protoplastos , Temperatura , Radioisótopos de Carbono , Contagem de Células , Parede Celular/metabolismo , Cryptococcus/metabolismo , Cryptococcus/patogenicidade , Citoplasma/metabolismo , DNA/biossíntese , Desoxiglucose/farmacologia , Proteínas Fúngicas/biossíntese , Glucose/metabolismo , Isoleucina/metabolismo , Microscopia de Contraste de Fase , Nefelometria e Turbidimetria , Osmose , RNA/biossíntese , Timidina/metabolismo , Trítio , Uracila/metabolismoRESUMO
Tobacco use is increasing among young people, especially in Gulf nations such as Saudi Arabia. The objectives of this study were to estimate the prevalence and behavioural patterns of tobacco use among undergraduate students at King Saud University, Riyadh, Saudi Arabia during the academic year 2008/09 and investigate factors that influenced their tobacco use. A cross-sectional study was done of a representative sample [n = 6793] of the undergraduate student population using a modified version of the global youth tobacco survey questionnaire. The prevalence of smoking was 14.5% among students, 22.2% and 2.2% among fathers and mothers and 43.1% and 14.8% for male and female siblings; 15.0% reported all or most of theirfriends smoked. The most important independent predictors of smoking were: friends' smoking [some: OR - 6.7 and all: OR - 54.9], sister's smoking [OR - 2.2], mother's smoking [OR = 2.1], single status [OR -1.7] and age [OR -1.18]