This article examines the generation of hot-spots and their impact in the heterogeneous SuzukiÀMiyaura coupling reaction for the synthesis of 4-methylbiphenyl in toluene solvent in the presence of Pd/AC. Hot-spots easily formed on the surface of the activated carbon (AC) catalyst support under high electric field conditions; they were recorded in real time using a high-speed camera. Chemical yields of 4-methylbiphenyl under the microwaves' magnetic field (H-field) were 2-fold greater than those under electric field (E-field) conditions at identical temperatures and reaction times (120 min). Microwave E-field irradiation with a high accuracy device enhanced generation of hotspots. Excessive formation of hot-spots impacted negatively on this coupling reaction.

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The Escherichia coli yqgF gene is highly conserved across a broad spectrum of bacterial genomes. The gene was first identified as being essential for cell growth during screening for targets for broad-spectrum antibiotics. YqgF is structurally similar to RuvC, a Holliday junction resolvase, but its function has not been established. This study describes the isolation of a temperature-sensitive yqgF mutant, the growth of which was inhibited by rho or nusA multicopy plasmids, indicating that YqgF is involved in transcription. Rho is a global transcription termination factor that acts at Rho-dependent terminator sites, which exist not only at the ends of genes but also within genes. The transcription of genes possessing intragenic, or upstream, Rho-dependent terminators was reduced in temperature-sensitive yqgF mutants. This transcription inhibition was sensitive to the Rho inhibitor, bicyclomycin. In addition, the transcription of mutant tnaA genes defective for upstream Rho-dependent termination was not significantly affected by the yqgF mutation. Taken together, these results suggest that YqgF is involved in anti-termination at Rho-dependent terminators in vivo.