RESUMO
Supplementary cementitious materials (SCMs), such as fly ash (FA) and ground granulated blast-furnace slag (GGBS), are often used as a partial replacement of cements to improve the sustainability of Portland cement-based materials and reduce their environmental impact. Superabsorbent polymers (SAPs) can be successfully used as internal curing agents in ultra-high performance cementitious materials by facilitating the hydration process and controlling the water supply in both fresh and hardened states. This paper intends to characterise the physical and chemical properties of SAPs and their sorption properties in different blended cement environments. The swelling capacity and kinetics of absorption of three superabsorbent polymers with different chemical compositions and grading were tested in different cement environments. Experimental results of their sorption performance in distinct solutions, including deionised water (DI), Portland cement (PC), and blended cements (PC-FA and PC-GGBS) and changes in pH of different solutions over time were investigated. The results showed that PC-FA solution had the lowest pH followed by PC-GGBS solution. Moreover, SAPs samples displayed the highest absorption capacities in PC-FA solutions, and the lowest swelling capacities were found in PC-GGBS solutions. Furthermore, SAP with smaller particle sizes had the greatest absorption capacity values in all solutions.
RESUMO
Background: We aimed to determine the correlation of BMI with depression and to determine the role of gender in this association, in a large study sample. Methods: We used the data of participants in the Iranian Children and Adolescents' Psychiatric Disorders (IRCAP) Study, conducted in 2017. This study was a national community-based, cross-sectional study in which the urban and rural areas of all provinces of Iran were covered. Overall 30,532 children and adolescents, ages 6-18, were randomly selected with the stratified cluster sampling method. Results: Of a total of 30,532 participants, 25,321, whose BMI had been measured and who had been interviewed with Kiddie Schedule for Affective Disorders and Schizophrenia (K-SADS), entered the study (12,455 boys and 12,866 girls). We categorized the participants according to the national cutoff points for BMI classification. After controlling for age, father's and mother's job and education, and place of residence, the odds ratio (OR) of depression in underweight, healthy weight, and overweight boys compared with obese boys was 2.19 [95% confidence interval (95% CI): 1.00-4.81], 1.06 (95% CI: 0.73-1.55), and 0.80 (95% CI: 0.49-1.32), respectively. In the girls' subgroup, after controlling for the aforementioned covariates, the OR of depression in healthy weight, overweight, and obese participants compared with underweight subjects was 1.29 (95% CI: 0.52-3.19), 1.54 (95% CI: 0.59-3.98), and 1.79 (95% CI: 0.68-4.69), respectively. Conclusions: Underweight boys were more likely diagnosed with depression than normal weight and overweight boys. While in girls, the probability of depression increased by increased BMI.
