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IEEE Open Journal of Engineering in... 2024Dynamically monitoring serotonin in real-time within target brain regions would significantly improve the diagnostic and therapeutic approaches to a variety of...
Dynamically monitoring serotonin in real-time within target brain regions would significantly improve the diagnostic and therapeutic approaches to a variety of neurological and psychiatric disorders. Current systems for measuring serotonin lack immediacy and portability and are bulky and expensive. We present a new miniaturised device, named SmartFSCV, designed to monitor dynamic changes of serotonin using fast-scan cyclic voltammetry (FSCV). This device outputs a precision voltage potential between -3 to +3 V, and measures current between -1.5 to +1.5 μA with nano-ampere accuracy. The device can output modifiable arbitrary waveforms for various measurements and uses an N-shaped waveform at a scan-rate of 1000 V/s for sensing serotonin. Four experiments were conducted to validate SmartFSCV: static bench test, dynamic serotonin test and two artificial intelligence (AI) algorithm tests. These tests confirmed the ability of SmartFSCV to accurately sense and make informed decisions about the presence of serotonin using AI.
PubMed: 38487099
DOI: 10.1109/OJEMB.2024.3356177 -
Nanoscale Apr 2024The development of advanced multi-functional electrocatalysts and their industrial operation on paired electrocatalysis systems presents a promising avenue for the...
Realizing ampere-level CO electrolysis at low voltage over a woven network of few-atom-layer ultralong silverene nanobelts with ultrahigh aspect ratio by pairing with formaldehyde oxidation.
The development of advanced multi-functional electrocatalysts and their industrial operation on paired electrocatalysis systems presents a promising avenue for the gradual penetration of renewable energy into practical production. Herein, a self-supported conductive network of silverene nanobelts (Ag-ene NBs) was delicately assembled (Ag-NB-NWs), in which ultralong and few-atom-layer Ag-ene NBs with a high edge-to-facet ratio were interconnected, serving as "superreactors" for electron transfer and mass transport during the reaction. Such superstructures as electrocatalysts delivered an unparalleled performance toward the CO-to-CO conversion with exclusively high faradaic efficiency (FE) and partial current densities of up to 1 A cm. Remarkably, the membrane electrode assembly (MEA) cell with Ag-NB-NWs as the cathode was capable of ultrastable and continuous operation for over 240 h at 0.4 A with ∼100% selectivity. More importantly, by further using Ag-NB-NWs as a bifunctional electrocatalyst, a record-low voltage overall CO electrolysis system coupling cathodic CO reduction with anodic formaldehyde oxidation in MEA cell was performed to achieve concurrent feed gas generation and formate production, substantially improving electrochemical techno-economic feasibility.
PubMed: 38482599
DOI: 10.1039/d4nr00361f -
Scientific Reports Mar 2024The interaction of localized light with matter generates optical electrostriction within dielectric fluids, leading to a discernible change in the refractive index of...
The interaction of localized light with matter generates optical electrostriction within dielectric fluids, leading to a discernible change in the refractive index of the medium according to the excitation's light profile. This optical force holds critical significance in optical manipulation and plays a fundamental role in numerous photonic applications. In this study, we demonstrate the applicability of the pump-probe, photo-induced lensing (PIL) method to investigate optical electrostriction in various dielectric liquids. Notably, the thermal and nonlinear effects are observed to be temporally decoupled from the electrostriction effects, facilitating isolated observation of the latter. Our findings provide a comprehensive explanation of optical forces in the context of the recently introduced microscopic Ampère electromagnetic formalism, which is grounded in the dipolar approximation of electromagnetic sources within matter and characterizes electrostriction as an electromagnetic-induced stress within the medium. Here, the optical force density is re-obtained through a new Lagrangian approach.
PubMed: 38454075
DOI: 10.1038/s41598-024-56176-1 -
Nature Communications Feb 2024Acidic CO electroreduction (COR) using renewable electricity holds promise for high-efficiency generation of storable liquid chemicals with up to 100% CO utilization....
Acidic CO electroreduction (COR) using renewable electricity holds promise for high-efficiency generation of storable liquid chemicals with up to 100% CO utilization. However, the strong parasitic hydrogen evolution reaction (HER) limits its selectivity and energy efficiency (EE), especially at ampere-level current densities. Here we present that enhancing COR intermediate coverage on catalysts promotes COR and concurrently suppresses HER. We identified and engineered robust CuSn catalysts with strong OCHO affinity and weak H binding, achieving 91% Faradaic efficiency (FE) for formic acid (FA) production at 1.2 A cm and pH 1. Notably, the single-pass carbon efficiency reaches a new benchmark of 77.4% at 0.5 A cm over 300 hours. In situ electrochemical Fourier-transform infrared spectroscopy revealed CuSn enhances OCHO coverage ~2.8× compared to Sn at pH 1. Using a cation-free, solid-state-electrolyte-based membrane-electrode-assembly, we produce 0.36 M pure FA at 88% FE over 130 hours with a marked full-cell EE of 37%.
PubMed: 38402216
DOI: 10.1038/s41467-024-45988-4 -
Numerical investigations of AC arcs' thermal characteristics in the short gap of copper-cored wires.Scientific Reports Feb 2024Excessive alternating current (AC) arcs generated in electric systems will accumulate heat and easily cause fire. This paper studies the thermal characteristics of...
Excessive alternating current (AC) arcs generated in electric systems will accumulate heat and easily cause fire. This paper studies the thermal characteristics of different numbers of AC arc plasma generated in a short gap of copper-cored wires in the air. The number of AC arcs is controlled in the AC arc experiment and an infrared thermal imager measures the temperature change at the specified position. Based on magnetohydrodynamics (MHD), a two-dimensional axisymmetric AC arc discharge numerical simulation model is established. The volt-ampere characteristic of the AC arc is used to solve the MHD simulation model to obtain the same 'zero current' characteristics as the real AC arc in the experiment. A large amount of heat accumulates in the electrode gaps when the arc generation, and then the heat dissipates in the 'zero current' stage. The continuously generated arc makes the temperature higher. The volume of the space area with a temperature higher than 10,000 K increases with the arc current, but is unrelated to the number of arcs. The volume of the space area with a temperature higher than 524.15 K and the temperature on the electrode are both positively correlated with the number of AC arcs and arc current. The results of this study can provide a reference for the detection standard of AC arc faults and the prevention of electrical fire.
PubMed: 38379089
DOI: 10.1038/s41598-024-54911-2 -
Proceedings of the National Academy of... Feb 2024Nickel-iron oxy/hydroxides (NiFeOH) emerge as an attractive type of electrocatalysts for alkaline water oxidation reaction (WOR), but which encounter a huge challenge in...
Nickel-iron oxy/hydroxides (NiFeOH) emerge as an attractive type of electrocatalysts for alkaline water oxidation reaction (WOR), but which encounter a huge challenge in stability, especially at industrial-grade large current density due to uncontrollable Fe leakage. Here, we tailor the Fe coordination by a MXene-mediated reconfiguration strategy for the resultant NiFeOH catalyst to alleviate Fe leakage and thus reinforce the WOR stability. The introduction of ultrafine MXene with surface dangling bonds in the electrochemical reconfiguration over Ni-Fe Prussian blue analogue induces the covalent hybridization of NiFeOH/MXene, which not only accelerates WOR kinetics but also improves Fe oxidation resistance against segregation. As a result, the NiFeOH coupled with MXene exhibits an extraordinary durability at ampere-level current density over 1,000 h for alkaline WOR with an ultralow overpotential of only 307 mV. This work provides a broad avenue and mechanistic insights for the development of nickel-iron catalysts toward industrial applications.
PubMed: 38377200
DOI: 10.1073/pnas.2319894121 -
Journal of Hazardous Materials Apr 2024Small microplastics (SMPs < 100 µm) can easily be transported over long distances far from their sources through the atmospheric pathways and reach even remote...
Small microplastics (SMPs < 100 µm) can easily be transported over long distances far from their sources through the atmospheric pathways and reach even remote regions, including the Arctic. However, these sizes of MPs are mostly overlooked due to different analytical challenges; besides, their pathways through atmospheric depositions, such as snow depositions, are mostly unknown. The spatial variability in bulk snow samples was investigated for the first time in distinct sites (e.g., glaciers) near Ny Ålesund, the world-known northernmost permanent research settlement in the Svalbard Islands, to better comprehend the presence of SMP pollution in snow. Seasonal snow deposited over the tundra and the summits of different glaciers were also sampled. A sampling procedure was designed to obtain representative samples while minimizing plastic contamination, thanks to rigorous quality assurance and quality control protocol. SMPs' weight (µg SMP L) and deposition load (mg SMPs m) result from being lower in the remote glaciers, where they may be subject to long-range transport. The SMPs' minimum length was 20 µm, with the majority less than 100 µm. Regarding their size distribution, there was an increase in the size length deriving from the local input of the human presence near the scientific settlement. The presence of some polymers might be site-specific in relation to the pathways that affect their distribution at the sites studied. Also, from the snow surface layer collected at the same sites to evaluate the variability of SMPs during specific atmospheric deposition events, the results confirmed their higher weight and load in surface snow near the scientific settlement compared to the glaciers. The results will enhance the limited knowledge of the SMPs in polar atmospheric compartments and deposition processes.
PubMed: 38359761
DOI: 10.1016/j.jhazmat.2024.133723 -
Angewandte Chemie (International Ed. in... Apr 2024Electroreduction of CO to C products provides a promising strategy for reaching the goal of carbon neutrality. However, achieving high selectivity of C products at high...
Electroreduction of CO to C products provides a promising strategy for reaching the goal of carbon neutrality. However, achieving high selectivity of C products at high current density remains a challenge. In this work, we designed and prepared a multi-sites catalyst, in which Pd was atomically dispersed in Cu (Pd-Cu). It was found that the Pd-Cu catalyst had excellent performance for producing C products from CO electroreduction. The Faradaic efficiency (FE) of C products could be maintained at approximately 80.8 %, even at a high current density of 0.8 A cm for at least 20 hours. In addition, the FE of C products was above 70 % at 1.4 A cm. Experiments and density functional theory (DFT) calculations revealed that the catalyst had three distinct catalytic sites. These three active sites allowed for efficient conversion of CO, water dissociation, and CO conversion, ultimately leading to high yields of C products.
PubMed: 38345401
DOI: 10.1002/anie.202400439 -
Brain Stimulation 2024The operation of a transcranial magnetic stimulation (TMS) coil produces high-intensity impulse sounds. In TMS, a magnetic field is generated by a short-duration pulse...
BACKGROUND
The operation of a transcranial magnetic stimulation (TMS) coil produces high-intensity impulse sounds. In TMS, a magnetic field is generated by a short-duration pulse in the range of thousands of amperes in the TMS coil. When placed in a strong magnetic field, such as inside a magnetic resonance imaging (MRI) bore, the interaction of the magnetic field and the current in the TMS coil can cause strong forces on the coil casing. The strengths of these forces depend on the coil orientation in the main magnetic field (B). Part of the energy in this process is dissipated in the form of acoustic noise.
OBJECTIVE
Our objective was to measure the sound pressure levels (SPL) of TMS "click" sounds created by commercial TMS stimulators and coils in a typical environment and inside a 3-T MRI scanner and advance the knowledge of the acoustic behaviour of TMS to safely conduct TMS alone as well as concurrently with functional MRI (fMRI).
METHODS
We report SPL measurements of two commercial MRI-compatible TMS systems in the 3-T B field of an MRI scanner and in the earth's magnetic field. Also, we present the acoustic noise measurements of four commercial TMS stimulators and three different TMS coils in a typical operational environment without the B field.
RESULTS
The maximum peak SPL measured was 158 dB(C) inside the 3-T MRI scanner. Outside the scanner, the maximum peak SPL was 117 dB(C). Inside the scanner, the peak SPL increased by 21-45 dB(C) depending on the stimulator and the orientation of the electric field relative to the B field.
CONCLUSIONS
Hearing protection is obligatory during concurrent TMS-fMRI experiments and highly recommended during any TMS experiment. The manufacturing of quieter TMS systems is encouraged to reduce the risk of hearing damage and other unwanted effects.
Topics: Magnetic Resonance Imaging; Transcranial Magnetic Stimulation; Humans; Noise; Acoustics
PubMed: 38342363
DOI: 10.1016/j.brs.2024.02.006 -
ACS Applied Materials & Interfaces Feb 2024Urea electrolysis is a promising energy-efficient hydrogen production process with environmental benefits, but the lack of efficient and sustainable ampere-level current...
Urea electrolysis is a promising energy-efficient hydrogen production process with environmental benefits, but the lack of efficient and sustainable ampere-level current density electrocatalysts fabricated through simple methods is a major challenge for commercialization. Herein, we present an efficient and stable heterostructure electrocatalyst for full urea and water electrolysis in a convenient and time-efficient preparation manner. Overall, superhydrophilic/superaerophobic CoMn/CuNiP/NF exhibits exceptional performance for the hydrogen evolution reaction (HER) (-33.8, -184.4, and -234.8 mV at -10, -500, and -1000 mA cm, respectively), urea electro-oxidation reaction (UOR) [1.28, 1.43, and 1.51 V (vs RHE) at 10, 500, and 1000 mA cm, respectively], and oxygen evolution reaction (OER) [1.45, 1.67, and 1.74 V (vs RHE) at 10, 500, and 1000 mA cm, respectively]. Moreover, the superaerophobic CoMn/CuNiP/NF demonstrates promising potential in full urea (1.33, 1.57, and 1.60 V at 10, 500, and 1000 mA cm, respectively) and water (1.46 V, 1.78, and 1.86 at 10, 500, and 1000 mA cm, respectively) electrolysis. Based on X-ray photoelectron spectroscopy results, it was determined that the surface of the CoMn/CuNiP electrode was rich in redox pairs such as Ni/Ni, Cu/Cu, Co/Co, and Mn/Mn, which are crucial for the formation of active sites for the OER and UOR, such as NiOOH, MnOOH, and CoOOH, thereby enhancing the catalytic activity. Besides, the in situ assembled CoMn/CuNiP/NF displayed highly stable performance for HER, OER, and UOR with high Faradaic efficiency for over 500 h. This research offers a simple and efficient method for manufacturing a high-efficiency and stable trifunctional electrocatalyst capable of delivering ampere-level current density in urea-assisted hydrogen production. Our density functional theory calculations reveal the potential of CoMn/CuNiP as an effective catalyst, enhancing the electronic properties and catalytic performance. The near-zero Gibbs free-energy change for HER underscores its promise, while reduced CO desorption energies and charge redistribution support efficient UOR. These findings signify CoMn/CuNiP's potential for electrochemical applications.
PubMed: 38326933
DOI: 10.1021/acsami.3c16122