Development of antibacterial ZnO-loaded cotton fabric based on in situ fabrication

A method provided for the deposition of nanostructured ZnO on cotton fabric to introduce antibacterial functionality was presented in this article. This strategy enabled fabric to be coated with inorganic-based functional materials through in situ synthesis of nanoparticles using ultrasonic irradiation. The amino-terminated silicon sol (AEAPTS) was employed to generate nanostructured ZnO, and the mechanism of the ultrasound-assisted coating was proposed. Antibacterial activities, UV protection and other properties of ZnO-loaded cotton characterized by SEM, FTIR, XRD and TGA were investigated. The results indicated that ZnO-loaded cotton exhibited excellent UV protective property, efficient antibacterial activities, well water-resistant effect, together with moderate cytotoxicity against L929 and lower tensile strength. The developed method provides not only a facile way for in situ synthesis of ZnO on textile but also the production of antibacterial materials for healthcare applications.

Feature-based tracking of urethral motion in low-resolution trans-perineal ultrasound

This paper describes a novel algorithm for tracking the motion of the urethra from trans-perineal ultrasound. Our work is based on the structure-from-motion paradigm and therefore handles well structures with ill-defined and partially missing boundaries. The proposed approach is particularly well-suited for video sequences of low resolution and variable levels of blurriness introduced by anatomical motion of variable speed. Our tracking method identifies feature points on a frame by frame basis using the SURF detector/descriptor. Inter-frame correspondence is achieved using nearest-neighbor matching in the feature space. The motion is estimated using a non-linear bi-quadratic model, which adequately describes the deformable motion of the urethra. Experimental results are promising and show that our algorithm performs well when compared to manual tracking.

Study of the activity and enantioselectivity of alginate-based catalysts in Friedel-Crafts reactions

This thesis is part of a long-term project which aims to demonstrate for the first time that alginate gel beads can be used as chiral heterogeneous catalysts for enantioselective reactions. Alginate barium beads were prepared as previously optimized and applied to the Friedel-Crafts reaction between indoles and nitroalkenes. New substrates were tested, showing that the reaction can accommodate different nitroalkenes and indoles, affording the corresponding products with moderate yields and good enantioselectivities. However, aliphatic nitroalkenes cannot be used as they degrade under the catalytic reaction conditions. Preliminary study on the recyclability of the heterogeneous catalyst indicated a moderate stability of the catalyst, which can be used for few cycles with a slight erosion of enantioinducing power. Some directions for future improvements (storage and work-up solvent, use of ultrasonic bath) have been suggested.