IEEE Trans Ultrason Ferroelectr Freq Control
April 2024
Complex architectures for wireless communications, digital electronics, and space-based navigation interlink several oscillator-based devices such as clocks, transponders, and synthesizers. Estimators characterizing their stability are critical for addressing the impact of random fluctuations (noise) on the overall system performance. Manufacturers typically specify this as an Allan/Hadamard Variance (AVAR/HVAR) profile in the time domain.
View Article and Find Full Text PDFWhile surface-confined Ullmann-type coupling has been widely investigated for its potential to produce π-conjugated polymers with unique properties, the pathway of this reaction in the presence of adsorbed oxygen has yet to be explored. Here, the effect of oxygen adsorption between different steps of the polymerization reaction is studied, revealing an unexpected transformation of the 1D organometallic (OM) chains to 2D OM networks by annealing, rather than the 1D polymer obtained on pristine surfaces. Characterization by scanning tunneling microscopy and X-ray photoelectron spectroscopy indicates that the networks consist of OM segments stabilized by chemisorbed oxygen at the vertices of the segments, as supported by density functional theory calculations.
View Article and Find Full Text PDFModel systems are critical to our understanding of self-assembly processes. As such, we have studied the surface self-assembly of a small and simple molecule, indole-2-carboxylic acid (I2CA). We combine density functional theory gas-phase (DFT) calculations with scanning tunneling microscopy to reveal details of I2CA assembly in two different solvents at the solution/solid interface, and on Au(111) in ultrahigh vacuum (UHV).
View Article and Find Full Text PDFNeurotoxins affecting neuroexocytosis can represent an innovative pharmacological approach to the investigation of neural mechanisms of pain. Our interest has been focused on the use of botulinum neurotoxins (BoNTs), whose peripheral effects are extensively documented, while the effects on the central nervous system are much less clear. We have investigated both peripheral (sc into the hindpaw) and central (icv) effects of two BoNTs isoforms, BoNT/A and BoNT/B, on inflammatory pain.
View Article and Find Full Text PDFThe current trend is to preserve the hindfoot joints to allow for more normal biomechanics and avoid arthritic changes in adjacent joints. Calcaneal osteotomies are effective in the treatment of hindfoot and foot malalignment with an acceptable rate of complications at medium-term follow-up. An important prerequisite should be flexibility and the absence of joint arthritis.
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