No abstract

Background Asthma and allergic complications are the most common chronic disorders in children and adolescents. This study aimed to determine the prevalence and severity of asthma, allergic rhinitis, eczema among schoolchildren, and some related risk factors. Methods The cross-sectional study was performed in 2019 and involved 4000 students aged 6–7 years and 4000 students aged 13–14 years (both girls and boys) from urban schools in Khuzestan Province, southwestern Iran. We used the multi-stage sampling method. Data were collected using the Persian version of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Results The prevalence of current wheeze, wheeze ever and asthma ever in the age group of 6–7 years was 3.8, 4.5, and 1.8%, respectively; in the age group of 13–14 years, it was 4.4, 5.9, and 3.4, respectively. In terms of gender, males (4.9, 6.0, and 2.7 percent, respectively) had substantially higher rates of current wheeze, wheeze ever, and asthma ever compared to the girls (2.8, 3.6, and 2.0 percent, respectively) (p < 0.001). The prevalence of rhinitis, Hay fever, and eczema among young people was 5.3%, 3.5%, and 1.0%, respectively. Current wheeze was more common in children with allergic rhinitis in the last 12 months (30.3% vs. 2.7%, p < 0.001), Hay fever (32.8% vs. 0.3%, p < 0.001) and eczema (27.8% vs 3.8%, p < 0.001), compared to children who did not. Conclusions The prevalence and severity of asthma symptoms were significantly associated with allergic rhinitis, eczema, and gender.

In this work, for the first time, functionalized 3D-network polymer was synthesized through thermal solvent-free method. The synthetic steps include (1) the preparation of ionic liquid (1-methyl-3-(trimethoxysilylpropyl) imidazolium choloride) [pmim]Cl, (2) synthesis of the 3D-network polymer based on calix[4]resorcinarene, and finally (3) immobilization of ionic liquid on the synthesize polymer through one-pot solvent-free conditions. The formation of this cationic porous polymer was confirmed by elemental analysis, scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and derivative thermogravimetric (DTG). Taken together, the results reveal the successful preparation of the efficient and wondrous mesoporous cationic polymer with the simultaneously merged properties of ionic liquid and polymeric matrix on the basis of calix[4]resorcinarene. Therefore, it provides an efficient heterogeneous catalyst for being applied in the catalytic reaction for achieving synthetic goals. One-pot conditions, thermal solvent-free pathway, easy reaction handling and work up, green and affordable methodology, gaining high yields of product are the most important advantages of the present method for the synthesis of this polymeric heterogeneous catalyst. The hydrophobic central cavity and hydrophilic cationic arms render it a suitable heterogeneous phase transfer catalyst for the preparation of valuable azidohydrins in water. The recovered catalyst could be used for several times without any significant loss of activity. The unique features of this catalyst such as superior thermal stability, excellent catalytic activity in terms of yield and reaction time, will be potentially important for its applications in industry.