In the model fungus Aspergillus nidulans, asexual development is induced from vegetative hyphae by a set of early regulators including the bZIP-type transcription factor FlbB. To determine the range of genes under the influence of the transcriptional activity of FlbB and to characterize their role in fungal development, we sequenced and compared the transcriptomes of a ΔflbB mutant and its isogenic wild-type strain at different developmental stages. Results confirmed the activating role of FlbB on downstream regulators of conidiation such as flbD and brlA. However, FlbB has additional functions beyond the induction of asexual development. Among the changes observed, absence of a functional FlbB caused induction of the dba cluster and synthesis of a secondary metabolite with bactericidal properties. In addition, a new transcriptional target of FlbB was unveiled, urdA, that codes for a putative transcription factor that represses premature sexual development. Taken together, our results indicate that the activators of asexual development simultaneously exert a role on other cellular functions, including an inhibitory effect on the sexual cycle, and reinforce the hypothesis that mutually exclusive metabolic and cellular patterns are associated with different morphogenetic programs.
Switched Reluctance Machines (SRM) are emerging as a possible alternative in terms of cost and supply stability to rare earth based electric vehicle traction systems. However, because of the huge amounts of energy stored and transferred back and forth between the DC source and the SRM, large DC-link capacitors must be used as buffers, which increases overall costs and size. This paper proposes a novel modulation technique which forces the exchange of energy between phases while decreasing the energy transfer between the DC bus and the SRM. This means lower DC bus currents (capacitor size and cost reduction) and lower Joule-effect conduction losses (better efficiency). The proposed modulation has been validated experimentally in a test bench and compared with the conventional torque-sharing function.
Organic contaminants significantly limit the bioactivity of titanium implants, resulting in the degradation known as the ageing of titanium. To reactivate the surfaces, they can be photofunctionalized, i.e., irradiated with C-range ultraviolet (UVC) light. This descriptive in vitro study compares the effectiveness of novel light-emitting diode (LED) technology to remove contaminant hydrocarbons from three different commercially available titanium dental implants: THD, TiUnite, and SLA. The surface topography and morphology were characterized by scanning electron microscopy (SEM). The chemical compositions were analyzed by X-ray photoelectron spectroscopy (XPS), before and after the lighting treatment, by a pair of closely placed UVC (λ = 278 nm) and LED devices for 24 h. SEM analysis showed morphological differences at the macro- and micro-scopic level. XPS analysis showed a remarkable reduction in the carbon contents after the UVC treatment: from 25.6 to 19.5 C at. % (carbon atomic concentration) in the THD; from 30.2 to 20.2 C at. % in the TiUnite; from 26.1 to 19.2 C at. % in the SLA surface. Simultaneously, the concentration of oxygen and titanium increased. Therefore, LED-based UVC irradiation decontaminated titanium surfaces and improved the chemical features of them, regardless of the kind of surface.