Enhanced antimicrobial activities of silver-nanoparticle-decorated reduced graphene nanocomposites against oral pathogens.

As a means of capitalizing on the synergistic properties between reduced graphene nanosheets (R-GNs) and silver nanoparticles (AgNPs), an efficient and convenient chemical reduction method was used to prepare silver-nanoparticle-decorated reduced graphene nanocomposites (R-GNs/Ag). The products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Raman spectroscopy, which confirmed the loading of well-dispersed silver nanoparticles on reduced graphene sheets. Their antimicrobial activities against oral pathogens such as Candida albicans, Lactobacillus acidophilus, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans were investigated by MIC determination, the counting of colony-forming units (CFU), agar diffusion tests, and growth curve observation. Compared with pure R-GNs and AgNPs, R-GNs/Ag composites exhibited enhanced antimicrobial properties owing to highly dispersed AgNPs on R-GNs.

[A New Pest of Amomum villosum in Xishuangbanna].

OBJECTIVE: To report a new pest of Amomum villosum and its distribution, occurrence regularity and damage situation, in order to provide reference for its control. METHODS: Reared the pest larvae, observed the morphological characters, and made a preliminary investigation on its distribution, occurrence regularity and damage situation. RESULTS: Through macroscopic examination, the pest was identified as Anisodera rugulosa, which distributed in the main producing areas of Amomum villosum in Xishuangbanna, the pest larvae ate the inside of Amomum villosum fruit, which made the fruit formed holes, more seriously, it made the whole fruit rot black. CONCLUSION: The pest causes the fruit yield reduction of Amomum villosum. Pest control work needs to be carry out as soon as possible.