ABSTRACT
The effects of microwave-assisted synthesis on the morphology and crystalline structure of WO3-graphene oxide (GO) composites have been investigated. Using two different microwave reactors, evidence supports that thermal and non-thermal effects significantly influence the properties of the synthesized materials. The findings reveal that the microwave cavity geometry affects how the microwaves are "delivered" to the reactional cavity as a function of time; it also orientates the growth process of the WO3 particles. Consequently, the crystalline structure and morphology are affected. As a result, the WO3-GO composites produced using a CEM reactor exhibit a rounded shape and hexagonal phase of WO3, besides enhanced reduction of GO. Whereas the composites made using an Anton-Paar reactor are composed of sheets and flowers of WO3 with hexagonal, triclinic and/or WO3 hydrate structures and cause a lower reduction on the GO.
ABSTRACT
Bacillus thuringiensis (Bt) toxins constitute effective, environmentally safe biopesticides. Nevertheless, insects' tolerance to Bt is influenced by environmental factors affecting immunity. To understand larval immune response in the devastating coleopteran insect pest Colorado potato beetle (CPB), we undertook a proteomic analysis of hemolymph of non-treated control larvae and larvae consuming non-lethal doses of spore-crystal mixtures containing the coleopteran-active Cry3Aa toxin. Results revealed lower amount of proteins involved in insect growth and higher amount of immune response-related proteins in challenged insects, sustaining the larval weight loss observed. Additionally, we found a potential regulatory role of the evolutionary conserved miR-8 in the insect's immune response relying on antimicrobial peptides (AMPs) production. Upon toxin challenge, different patterns of hemolymph AMPs expression and phenoloxidase activity were observed in CPB larvae reared on different Solanaceae plants. This suggests that diet and diet-associated insect midgut microbiota might modulate this insects' tolerance to non-lethal doses of Bt.
