The performance of optical devices relying in vanadium dioxide (VO) technology compatible with the silicon platform depends on the polarization of light and VO properties. In this work, optical switching in hybrid VO/Si waveguides thermally triggered by lateral microheaters is achieved with insertion losses below 1 dB and extinction ratios above 20 dB in a broad bandwidth larger than 30 nm. The optical switching response has been optimized for TE and TM polarizations by using a homogeneous and a granular VO layer, respectively, with a small impact on the electrical power consumption. The stability and reversibility between switching states showing the possibility of bistable performance is also demonstrated.
were determined by X-ray diffraction, high resolution electron microscopy, energy dispersive spectroscopy and nitrogen adsorption. The antimicrobial potential of ZnO@ZIF-8 for reduction of microorganisms often implicated with catheter-associated urinary tract infections (CAUTIs) was studied in detail using four target pathogens, Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Staphylococcus aureus. The ability of the compound to kill all four microorganisms in suspension was established and a minimum bactericidal concentration of 0.25 mg mL -1 was determined for each microorganism. ZnO@ZIF-8 compound was found to be no more toxic to Galleria mellonella than distilled water, which was assessed by injection of Galleria with 10 µL of ZnO@ZIF-8 of concentrations of up to 2 mg mL -1 . ZnO@ZIF-8 suspensions (2 mg mL -1 concentration) were able to reduce well-established biofilms of all four oraganisms containing between 10 7 and 10 9 CFU mL -1 to below limit of detection (BLD) over a 24-h period. Silicone-embedded ZnO@ZIF-8 (2wt.% or 4 wt.% ZnO@ZIF-8 loading) also demonstrated antimicrobial properties with all four microorganisms being eliminated from the surface within 24 h. The ZnO@ZIF-8 high potency and rapid anti-biofilm activity against all four test organisms coupled with its non-toxicity offers a new avenue for control of microbial colonization of catheters, which would ultimately result in reduction of CAUTIs.
Iron-Catalyzed Tandem Cyclization and Cross-Coupling Reactions of Iodoalkanes and Aryl Grignard Reagents. -The reaction is assumed to proceed via a radical process. In the case of substituted alkenes (XV) and (XVII) an internal cyclization precedes the cross-coupling pathway, presumably due to the steric congestion. -(KIM, J. G.; SON, Y. H.; SEO, J. W.; KANG*, E. J.; Eur.
Black soldier fly (BSF) larvae (Hermetia illucens) are voracious feeders that can be reared on food waste streams originating from the food industry and retailers. Because these food waste streams are automatically being unpacked in substantial amounts, they can contain microplastics, potentially jeopardising the larvae’s chemical safety when applied as compound feed ingredients. During this study, the dynamics of ingestion and excretion of microplastics by BSF larvae reared on substrates containing different contents (wMP = 0.00, 0.01, 0.10, 0.50, 1.00, 3.00%) of fluorescent blue-labelled microplastics (median size, Dv(50) = 61.5 µm) were monitored. To correlate the particle size with their uptake, larval mouth opening dimensions were measured during the rearing process. In conclusion, it appeared that ingestion of microplastics by BSF larvae depends on initial particle load, mouth size, and consequently also age. The larvae took up between 131 (wMP = 0.01%) and 4866 (wMP = 3.00%) particles leading to bioaccumulation factors (BAF) between 0.12 (wMP = 3.00%) and 1.07 (wMP = 0.01%). Larvae also appeared to excrete the microplastics, lowering the BAFs to values between 0.01 (wMP = 3.00%) and 0.54 (wMP = 0.01%).
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