Scanning electrochemical microscopy (SECM) has been extensively used for mapping electrocatalytic surface reactivity; however, most of the studies were carried out using micrometer-sized tips, and no quantitative kinetic experiments on the nanoscale have yet been reported to date. As the diffusion-limited current density at a nanometer-sized electrode is very high, an inner-sphere electron-transfer process occurring at a nanotip typically produces a kinetic current at any attainable overpotential. Here, we develop a theory for substrate generation/tip collection (SG/TC) and feedback modes of SECM with a kinetic tip current and use it to evaluate the rates of hydrogen and oxygen evolution reactions in a neutral aqueous solution from the current-distance curves. The possibility of using chemically modified nanotips for kinetic measurements is also demonstrated. The effect of the substrate size on the shape of the current-distance curves in SG/TC mode SECM experiments is discussed.
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http://dx.doi.org/10.1021/acs.analchem.4c01019 | DOI Listing |
Magn Reson Imaging
January 2025
Institute of Fluid Mechanics, University of Rostock, Rostock, Germany.
Purpose: To improve the current method for MRI turbulence quantification which is the intravoxel phase dispersion (IVPD) method. Turbulence is commonly characterized by the Reynolds stress tensor (RST) which describes the velocity covariance matrix. A major source for systematic errors in MRI is the sequence's sensitivity to the variance of the derivatives of velocity, such as the acceleration variance, which can lead to a substantial measurement bias.
View Article and Find Full Text PDFEnviron Res
January 2025
Key Laboratory of Chemical Additives for China National Light Industry, Shaanxi University of Science and Technology, 710021 Xi'an, China.
For the effective removal of phenol from the environment, photocatalytic synergistic adsorption is currently one of the key methods. By leveraging the polysaccharide backbone structure of sodium alginate (SA),Zinc hydroxystannate (ZHS) was introduced into the gel structure using a co-precipitation technique. Additionally, gangue waste was repurposed through a polymerization reaction.
View Article and Find Full Text PDFBiomater Adv
January 2025
Department of Biological Sciences and Engineering, Indian Institute of Technology Gandhinagar, Gujarat, India. Electronic address:
Deep cutaneous wounds, which are difficult to heal and specifically occur on dynamic body surfaces, remain a substantial healthcare challenge in clinical practice because of multiple underlying factors, including excessive reactive oxygen species, potential bacterial infection, and extensive degradation of the extracellular matrix (ECM) which further leads to the progressive deterioration of the wound microenvironment. Any available individual wound therapy, such as antibiotic-loaded cotton gauze, cannot address all these issues. Engineering an advanced multifunctional wound dressing is the current need to promote the overall healing process of such wounds.
View Article and Find Full Text PDFViruses
January 2025
Department of Immunology and Microbiology, Scripps Research Institute, La Jolla, CA 92037, USA.
Lassa fever (LF), a viral hemorrhagic fever disease with a case fatality rate that can be over 20% among hospitalized LF patients, is endemic to many West African countries. Currently, no vaccines or therapies are specifically licensed to prevent or treat LF, hence the significance of developing therapeutics against the mammarenavirus Lassa virus (LASV), the causative agent of LF. We used in silico docking approaches to investigate the binding affinities of 2015 existing drugs to LASV proteins known to play critical roles in the formation and activity of the virus ribonucleoprotein complex (vRNP) responsible for directing replication and transcription of the viral genome.
View Article and Find Full Text PDFPolymers (Basel)
January 2025
Rheology Department, Polymat Institute, University of the Basque Country, 20018 Donostia-San Sebastian, Euskadi, Spain.
This paper addresses the author's current understanding of the physics of interactions in polymers under a voltage field excitation. The effect of a voltage field coupled with temperature to induce space charges and dipolar activity in dielectric materials can be measured by very sensitive electrometers. The resulting characterization methods, thermally stimulated depolarization (TSD) and thermal-windowing deconvolution (TWD), provide a powerful way to study local and cooperative relaxations in the amorphous state of matter that are, arguably, essential to understanding the glass transition, molecular motions in the rubbery and molten states and even the processes leading to crystallization.
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