No abstract

The goal of this study is to improve the qualities of Saudi cotton fabrics to be used in a variety of industrial and medicinal applications. Cotton fabrics were treated by dipping in chitosan/ZnO-NPs solutions with various ZnO-NPs concentrations. XRD and SEM of crystal and morphological structure, thermal analysis (TG and DSC) of fabric stability for heat assessment, were used to characterize the fabrics. The produced textiles were tested for antimicrobial activity against Gram-positive Staphylococcus aureus, Gram-negative Escherichia coli (bacteria), and Aspergillus niger, Candida albicans (fungus) using agar diffusion method. According to the XRD data, the fabrics treated with chitosan and by increasing the concentration of ZnO-NPs had increased crystallinity. The successful deposition and strong binding of chitosan and ZnO-NPs to the fabric surface, and the obvious change in fabric morphology, were confirmed by SEM micrographs. The pyrolysis peak positions were changed to a higher temperature. The creation of the inhibitory zone indicated that the treated fabrics had bactericidal effects. The results could be useful in an open innovation approach to improving the qualities of treated textiles that point to their use in medical applications.

Recently, paediatric cardiac computed tomography (CCT) has caused concerns that diagnostic image quality and dose reduction may require further improvement. Consequently, this study aimed to establish institutional (local) diagnostic reference levels (LDRLs) for CCT for paediatric patients, and assess the impact of tube voltage on proposed DRLs in terms of the volume computed tomography index (CTDIvol) and dose length product (DLP). In addition, effective doses (EDs) of exposure were estimated. A population of 453 infants, whose mass and age were less than 12 kg and 2 years, respectively, were considered from January 2018 to August 2021. Based on previous studies, this number of patients was considered to be sufficient for establishing LDRLs. A group of 245 patients underwent CCT examinations at 70 kVp tube voltage with an average scan range of 23.4 cm. Another set of 208 patients underwent CCT examinations at 100 kVp tube voltage with an average scan range of 15.8 cm. The observed CTDIvol and DLP values were 2.8 mGy and 54.8 mGy.cm, respectively. The mean effective dose (ED) was 1.2 mSv. It is concluded that provisional establishment and use of DRLs for cardiac computed tomography in children are crucial, and further research is needed to develop regional and international DRLs.