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Three phase inverters with switching frequencies above 100 kHz have recently become feasible thanks to the significant progress made in wide band gap (WBG) semiconductor technology. The main drivers behind the intense research and development of these ultrahigh switching frequency pulsewidth modulation (PWM) inverters are the extraordinary gravimetric and volumetric power densities that can be achieved. On the other hand, not as much attention has been devoted to the loads that these inverters supply, quite frequently consisting in ac motors. The impact of sub-MHz PWM and of the associated tens of nanoseconds range switching transients on motor terminal overvoltage, common mode currents, and losses are still to be discussed exhaustively. The authors have thus decided to investigate what happens to induction motors (IM) supplied by inverters having switching frequencies up to 350 kHz. After an introduction on WBG semiconductor devices, the article presents some interesting experimental observations conducted on a 1.1 kW four-pole IM fed by a silicon carbide (SiC) inverter. Further insight is provided by tests on a laminated steel toroid, supplied by a single-phase full bridge SiC inverter. Discussions on the experimental results highlight the previously unreported impact of common mode losses, which become a predominant part of the PWM harmonic losses. [ABSTRACT FROM AUTHOR]

Abstract: The TAM subfamily of Receptor Tyrosine Kinases (RTKs) contains three human proteins of therapeutical interest, Axl, Mer, and Tyro3. Our goal was to design a type II inhibitor specific for this family, i.e. able to interact with the allosteric pocket and with the hinge region of the kinase. We report the synthesis of several series of purine analogues of BMS-777607. The structural diversity of the designed inhibitors was expected to modify the interactions formed in the binding site and consequently to modulate their selectivity profiles. The most potent inhibitor 6g exhibits K ds of 39, 42, 65 and 200 nM against Axl, Mer, Met and Tyro3 respectively. Analysis of the affinity of 6g for active and inactive forms of Abl1, an RTK protein that does not belong to the TAM subfamily, together with the binding modes of 6g predicted by docking studies, indicates that 6g displays some selectivity for the TAM family and may act as a type II inhibitor. [Copyright &y& Elsevier]

The extensive electrification process that is taking holds in several applications makes increasingly necessary the virtualization of electric components for energetic and performance assessments during the system design stage. For this purpose, this article proposes a straightforward methodology for computing the efficiency maps of induction machines (IMs) operated in wide torque-speed ranges. The modeling approach is based on the IM equivalent circuit defined in the rotor dq coordinates. The procedure allows computing a set of efficiency maps at different machine temperatures and supply voltage levels, both for motor and generator operation modes. The equivalent circuit parameters at different frequencies and voltages are determined by means of the well-known no-load and locked-rotor tests, thus including in the modeling the machine nonlinearities, skin effect and the iron losses. The proposed methodology has been validated on a 10 kW, four-pole IM. The comparison between computed and experimental efficiency maps for different operating conditions, confirm the validity of the proposed methodology. [ABSTRACT FROM AUTHOR]

This research work investigates the phenomenon of interbar currents in induction motors equipped with die-cast aluminum cages. Flowing in the lamination and distorting the bar current distributions, the interbar currents cause additional stray losses as well as an increase of the joule loss in the cage bars. The contact resistance between the bars and the rotor laminations is the key modeling element for a correct prediction of the interbar currents and the related extra losses. The study presents a new noninvasive method to obtain a reliable estimation of the contact resistance. The proposed hybrid approach is based on a mix of experimental data and Finite Element method (FEM)-based simulation results. A reliable three-dimensional FEM model of a four-pole 15-kW induction motor with closed rotor slots has been used to investigate the impact of variable contact resistance on the interbar currents, rotor joule losses, and the voltage drops along the bars, opening a new perspective for this complex phenomenon and its impact on the stray losses. Finally, the proposed methodologies are critically discussed and the obtained results compared with other relevant research works. [ABSTRACT FROM AUTHOR]

We have previously described a highly diverse library of artificial repeat proteins based on thermostable HEAT-like repeats, named αRep. αReps binding specifically to proteins difficult to crystallize have been selected and in several examples, they made possible the crystallization of these proteins. To further simplify the production and crystallization experiments we have explored the production of chimeric proteins corresponding to covalent association between the targets and their specific binders strengthened by a linker. Although chimeric proteins with expression partners are classically used to enhance expression, these fusions cannot usually be used for crystallization. With specific expression partners like a cognate αRep this is no longer true, and chimeric proteins can be expressed purified and crystallized. αRep selection by phage display suppose that at least a small amount of the target protein should be produced to be used as a bait for selection and this might, in some cases, be difficult. We have therefore transferred the αRep library in a new construction adapted to selection by protein complementation assay (PCA). This new procedure allows to select specific binders by direct interaction with the target in the cytoplasm of the bacteria and consequently does not require preliminary purification of target protein. αRep binders selected by PCA or by phage display can be used to enhance expression, stability, solubility and crystallogenesis of proteins that are otherwise difficult to express, purify and/or crystallize. [ABSTRACT FROM AUTHOR]

The new model is based on a modified Steinmetz equation and employs a hysteresis-loss multiplicative coefficient and a combined coefficient for eddy-current and excess losses, both coefficients being variable with induction and frequency. The material model coefficients are first identified through multifrequency tests with sine-wave excitation. The iron-loss increase due to pulsewidth-modulation supply is estimated using global waveform parameters of the nonsinusoidal voltage. The study includes three different grades of non-grain-oriented electric steel. The data cover a wide range of fundamental frequency from 10 to 600 Hz and induction from 0.05 to 2 T. The errors of the computational model are small at relatively low fundamental frequency and increase thereafter. The main advantages of the model are its simplicity of use and minimal data requirements. [ABSTRACT FROM AUTHOR]

Objective: The first objective of this study is to compare two molecular markers, cysteic acid and protein carbonylation, to track the level of chemical oxidation and photochemical (UV) oxidation of human hair. The second objective is to investigate how the protein carbonylation biomarker evolution is associated with physical characteristics of the fibre. The third objective is to understand the damage localization within the hair sub-structure., Materials and Methods: For the chemical oxidation study European natural hair 6/0 (medium brown) is treated with non-pigmented commercial hair colour mixture and hair bleaching in increasing chemical oxidation conditions. For the photochemical study two European natural hair colours, 4/0 (dark brown) and 9/0 (extra light blond) are gradually photo irradiated. Molecular changes are investigated through cysteic acid measurement by NIR spectroscopy and protein carbonylation measurement; Biophysical changes by differential scanning calorimetry (DSC), and tensile strength measurements. Carbonyls are labelled with a specific fluorescent probe and measured in gel electrophoresis and in situ through image analysis and densitometric quantification after protein extraction respectively., Results: The two molecular markers, cysteic acid and protein carbonylation, increase similarly in both chemical and photochemical oxidation cases and show a good level of association across the oxidation levels. The fibre physical characteristics (DSC, Tensile Strength) decrease while the protein carbonylation and cysteic acid increase. The in situ visualization of the protein carbonylation shows a high impact on the hair cuticle and a gradual increase of photo-oxidation through the cortex, phenomenon which is more prominent for the extra light blonde hair in the case of photochemical oxidation., Conclusion: The protein carbonylation biomarker is validated as another key molecular marker to monitor oxidative chemical changes in the hair chemical groups. It complements the cysteic acid, and appears more suitable in the case of photochemical oxidation, where it offers clear advantages over cysteic acid by being more sensitive and accurate, and by allowing in situ distinct damage visualization. Besides cysteic acid, amino acids such as proline, threonine, arginine, lysine, and peptide bonds are targets of oxidation. Under photochemical oxidation, the photoprotective effect of melanin is confirmed., (© 2025 Henkel Corporation. International Journal of Cosmetic Science published by John Wiley & Sons Ltd on behalf of Society of Cosmetic Scientists and the Société Française de Cosmétologie.)

Background: Increased protein carbonylation is a hallmark of oxidative stress, protein homeostasis dysregulation and aging in the nervous system and skin. Sensory neurons interact with skin cells and are involved in skin homeostasis. We have previously reported that the 5-octanoyl salicylic acid (C8-SA), a salicylic acid derivative, increased C. elegans lifespan and delayed the accumulation of carbonylated proteins, through the stimulation of autophagy., Objectives: In this study we aimed to investigate if C8-SA protects human sensory neurons and human skin from extrinsic oxidative stressors as an approach to delay skin aging., Methods: In vitro reconstituted human epidermis innervated with hiPSc-derived human sensory neurons, as well as ex vivo human organotypic full skin models were used. The fully differentiated sensory neurons were pretreated with C8-SA before oxidative stress induction. Skin explants were maintained in culture and treated topically with C8-SA before the application of urban pollutants. Carbonylated proteins were detected using amino-oxy functionalized fluorophores and quantified. Chaperone mediated autophagy was monitored with LAMP2A immunofluorescence. Inflammation, ROS detoxification and autophagy were assessed by RT-PCR., Results: C8-SA prevented the accumulation of carbonylated proteins, both in human sensory neurons and skin explants. C8-SA stimulated chaperone-mediated autophagy and modulated NRF2 antioxidant response genes, as well as catalase enzymatic activity., Conclusions: C8-SA acts at two levels to protect skin against oxidative stress: 1) it prevents protein oxidation by stimulating endogenous antioxidant defense and 2) it increases the clearance of oxidized proteins by stimulating chaperone-mediated autophagy. These results suggest that C8-SA maintains skin health in urban polluted environments., (Copyright © 2022 Elsevier Inc. All rights reserved.)

YabT is a serine/threonine kinase of the Hanks family from Bacillus subtilis , which lacks the canonical extracellular signal receptor domain but is anchored to the membrane through a C-terminal transmembrane helix. A previous study demonstrated that a basic juxtamembrane region corresponds to a DNA-binding motif essential for the activation of YabT trans-autophosphorylation. YabT is expressed during spore development and localizes to the asymmetric septum where it specifically phosphorylates essential proteins involved in genome maintenance, such as RecA, SsbA, and YabA. YabT has also been shown to phosphorylate proteins involved in protein synthesis, such as AbrB and Ef-Tu, suggesting a possible regulatory role in the progressive metabolic quiescence of the forespore. Finally, cross phosphorylations with other protein kinases implicate YabT in the regulation of numerous other cellular processes. Using an artificial protein scaffold as crystallization helper, we determined the first crystal structure of this DNA-dependent bacterial protein kinase. This allowed us to trap the active conformation of the kinase domain of YabT. Using NMR, we showed that the basic juxtamembrane region of YabT is disordered in the absence of DNA in solution, just like it is in the crystal, and that it is stabilized upon DNA binding. In comparison with its closest structural homolog, the mycobacterial kinase PknB allowed us to discuss the dimerization mode of YabT. Together with phosphorylation assays and DNA-binding experiments, this structural analysis helped us to gain new insights into the regulatory activation mechanism of YabT.

In this study, we describe the synthesis of new pyrimidine analogs of BMS-777607, a potent and selective inhibitor of Met kinase. Inhibition of Met and Axl remained high whereas inhibition of Tyro3 and Mer decreased to some extend. The preferential moderate inhibition of the non-phosphorylated form of Abl1 of some derivatives suggests that they behave as type II inhibitors. This hypothesis was confirmed by docking studies into the structure of Met (3F82) and in a Tyro3 model where key interactions with the hinge region, the DFG-out motif and the allosteric pocket explain this inhibition., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)