SIRT1 targeted bioengineered extracellular vesicles chrono-reprogram microglia to reverse non-dipping hypertension - myocardial remodeling and comorbid neuropsychiatric disorders under stress.

Exact optical characteristics of the trivalent lanthanideions(Ln3+) are crucially determined by their nearest neighborsand in turn govern the quantum efficiency of Ln3+-dopedupconverting nanoparticles (UCNPs). Their often extremely low quantumefficiency can be increased considerably by doping Ln3+ into disordered host lattices. In these lattices, each Ln3+ experiences a slightly different low-symmetry environment, whichleads to small variations in its (optical) properties. To this end,we predict crystal field energy levels and oscillator strengths ofEr3+, Tm3+, and Yb3+ doped into disorderedhexagonal (β-)­NaYF4 and ordered LiYF4.In addition, theoretical photoluminescence spectra for β-NaYF4:Er3+ were determined. The results were obtainedusing a wave function-based ab initio computational approach and anembedded cluster model. The disorder of β-NaYF4:Ln3+ was accounted for through weighted averaging, in which stochasticconsiderations and Boltzmann distributions for several local configurationswere included. Comparison to experimental and semiempirical data showedparticularly good agreement for both the ordered and disordered material.The disordered lattice significantly shifted the crystal field energylevels and changed the oscillator strengths of the respective Ln3+ transitions. Importantly, the computed photoluminescencespectra showed the best agreement with experimental spectra when includingthe predicted results of all disordered configurations individually.This reveals that the observed energetic splitting and transitionrates of the excited Ln3+ dopants can only be accuratelydescribed if the disorder of the β-NaYF4 crystalis properly considered. The proposed quantum chemical protocol pavesthe way for the future simulation of photon upconversion processesin UCNPs.

Hypothyroidism is associated with the desynchronization of central and peripheral circadian clocks; however, its effects on renal rhythmicity remain unclear. This study investigated the impact of short-term hypothyroidism on renal molecular clock oscillations and daily kidney function in male and female rats. Hypothyroidism was induced by thyroidectomy followed by methimazole and CaCl2 administration for 21 days. Renal handling of solutes and electrolytes and the expression of core clock components were evaluated every 6 h over 24 h. Urinary levels of creatinine, protein, glucose, and sodium and the clearance and fractional excretion (FE) of these solutes exhibited circadian oscillations in control rats. In males, hypothyroidism abolished the rhythmicity of serum creatinine, creatinine clearance (CCr), renal glucose clearance (Cglucose), and fractional excretion of glucose, sodium, and potassium; decreased the mesor and amplitude of protein excretion parameters; reduced mesor and amplitude of Bmal1 expression and phase advanced Per2 and Nr1d1 mRNA expression. In females, hypothyroidism reduced the mesor of urinary creatinine, serum glucose, and CCr while delaying its acrophase; increased the mesor of proteinuria and glucosuria and the mesor and amplitude of Cglucose and FEglucose; and disrupted the circadian pattern of FEprotein and Per2 and Nr1d1 expression in kidney and phase advanced Bmal1 expression. Sodium and potassium daily handlings were more altered in males than in females. No structural damage was found in the kidney of hypothyroid rats. These findings indicate that short-term hypothyroidism desynchronizes the renal circadian clock and disturbs the daily rhythmicity of several renal parameters in a sex-dependent manner, potentially contributing to early-stage kidney dysfunction.NEW & NOTEWORTHY Hypothyroidism alters the kidney circadian clock machinery and renal function in a sex-dependent manner, potentially contributing to early-stage kidney dysfunction. Female rats exhibited more severe rhythmic impairments under hypothyroid conditions, including reduced creatinine clearance, increased protein and glucose loss in urine over 24 h, and disrupted circadian oscillations in renal clock components, indicating a greater susceptibility of females to hypothyroidism-induced metabolic disturbances associated with circadian disruption.

This paper presents a comprehensive comparative review and detailed analysis of the weak antilocalization (WAL) effect observed in PdxBi₂Se₃ whiskers in comparison with well-established results for Bi₂Se₃ single crystals and thin films, which serve as benchmark systems for the study of topological insulators. The literature review highlights the influence of sample morphology, the nature of doping elements, structural disorder, and strong spin–orbit coupling on the parameters that govern coherent quantum transport in these materials. Special emphasis is placed on the unique combination of whisker-like morphology, Pd doping, and the observation of residual surface superconductivity in our samples, which makes these structures promising candidates for further research in the field of topological quantum matter. For comparison, three representative studies were selected: one describing WAL in Pd-doped Bi₂Se₃ single crystals grown by the zone-melting technique, another reporting on a detailed analysis of WAL and Shubnikov–de Haas (SdH) oscillations in undoped Bi₂Se₃ thin films, and a third study examining WAL and quantum oscillations in pure Bi₂Se₃ single crystals without any intentional doping. The comparative analysis shows that the phase coherence length in our whisker samples is lower than in massive single crystals and thin films, yet the unique combination of whisker morphology and Pd doping favors the coexistence of WAL with residual surface superconductivity, a feature not observed in previous Bi₂Se₃ systems. In addition, our measurements indicate the presence of weak nematic anisotropy, visible as a slight directional asymmetry of the upper critical magnetic field. Such a combination of features opens up new possibilities for studying the interaction between topologically protected surface states and superconducting phases, which is highly relevant for the design of novel quantum devices and spintronic applications. The results expand the current understanding of how topological surface states can be tuned and controlled through targeted engineering of the material's morphology, chemical composition, and growth conditions. This research provides a foundation for future experimental efforts aimed at optimizing the properties of nanostructured superconducting topological materials based on Bi₂Se₃ whiskers.

Land travel on highways in developing countries, such as Cameroon, faces significant safety challenges due to factors like natural disasters, poor road networks, low-quality vehicles, error-prone drivers, and negligent pedestrians, with government investments showing only minor improvements in reducing road accidents. This paper proposes an Internet of Things (IoT) based FM broadcast system to enhance highway safety by providing real-time and timely guides to drivers. The proposed system comprises three main units: a Roadside Unit (RSU), an Onboard Unit (OBU), and a Control Centre (CC). The RSU is an IoT-based smart unit built around a Raspberry Pi 4 Model B, equipped with environmental sensors (DHT11 for temperature/humidity, ROBODO 130008 for rain) and internet connectivity. It integrates a locally designed 5W Phase Locked Loop (PLL) FM transmitter, set to a test frequency of 100.8 MHz, with a broadcast radius of 10 km. Python code on the RSU utilizes APIs like OpenWeatherMap and Google Suite to gather real-time weather forecasts, environmental data, traffic conditions (estimated arrival times, delays), and information on nearby places (parking, gas stations, lodging). It also dynamically suggests speed limits based on real-time weather and generates audio warnings for adverse conditions and road events. The system primarily uses an audio-only broadcast to minimize driver distraction. The OBU functions as a specialized receiver, consisting of a Raspberry Pi 4 Model B with an RTL-SDR dongle that demodulates and outputs FM audio to speakers, with GNU Radio software processing the signals. A remote-Control Centre manages and configures RSUs securely via SSH, enhancing operational efficiency. Experimental results confirm the system's effectiveness. The locally designed FM transmitter demonstrated robust performance with a total RF gain of 43 dB and stable 5W output power, along with excellent frequency stability (±50 ppm crystal oscillator, -90 dBc/Hz VCO phase noise). Performance indicators like Signal-to-Noise Ratio (SNR), Modulation Error Rate (MER), and power spectrum were analysed. SNR showed an inverse relationship with distance, dropping to -40.36 dB at 5000m, which is acceptable for highway radio quality, and tracked closely with a commercial transmitter. MER analysis indicated proper functioning of the transmitter-receiver pair, as demodulated signals exhibited tightly clustered constellation points, implying high SNR and better audio quality. Furthermore, the power spectrum showed minimal variation between original and received audio signals, with an improved gain post-modulation, ensuring clear audio output. This comprehensive system provides a robust and cost-effective solution for real-time highway advisories in developing countries.

Aim of the article: Analitical calculations and preliminary estimates of efficiency of a chemical generators are of great importance for analysis of conversion chemical energy into electrical one, the base which was consist transformation of heterogeneous chemical energy of formation hydrogen molecules into energy of electronic excitation on the surface of catalyst-semiconductors. However in the works cited by the calculation of probability excitation of chemo-electrons (high-energy electrons in conduction band) is not taken into account of the phonon’s channel of the chemical energy accommodation. Such consideration would be by disdain of interaction excited electron with lattice, but in condition of the scattering chemical reaction energy inevitably was shifted of the equilibrium position of oscillators, leading to emission and absorption of phonons. Therefor the technique of the calculation must take into account as electrons as phononschannels of the accomodation. Aim of given work is derivation of the theoretical formula for efficiency of chemo-generator with provision for thermo-stimuleted transition of electrons to conduction band, with the subsequent analysis of particular cases.Theoretical part: The influence of local thermal oscillations of crystal were inducted the effect of chemical reaction energy of formation hydrogen molecules on the “catalyst” surface, on velocity generation of the high-energy electrons was theoretical investigated. The formulas for efficiency of generator, clarifying the corresponding formulas from the other works was obtained. It is indicated on an impotant part of thermo-stimuleted transitions of an electrons to the conduction band of the semiconductor at room temperatures.Conclusions: The results obtained may be useful by qualitatively analysis of the accommodation mechanisms of a chemical energy in the context of problem of conversion a chemical energy to electrical one

The circadian clock orchestrates adipocyte development and lipid remodeling, with its disruption leading to the development of obesity and insulin resistance. Here we demonstrate that the flavonoid compound naringenin displays clock modulatory activity via RORα that suppresses adipocyte lipid storage while promoting browning. In adipogenic progenitors, naringenin activates RORα with induction of clock gene expression to promote circadian clock oscillation with protective effect against cytokine-induced dampening. The clock-enhancing properties of naringenin suppressed lipogenesis in mature adipocytes together with induction of browning characteristics. The inhibitory effect of naringenin on lipogenesis was dependent on clock modulation as it was abolished in RORα-deficient adipocytes. We further show that naringenin administration in vivo up-regulated RORα expression with clock gene induction together with browning of subcutaneous beige fat depot, resulting reduced fat mass and body weight. Naringenin treatment in vivo also lowered plasma glucose and free fatty acid levels, with markedly enhanced insulin signaling in adipose depots and skeletal muscle. Collectively, our findings uncover a new clock-activating mechanism of action in mediating the metabolic benefits of naringenin, suggesting its potential as a natural supplement for anti-obesity and metabolic disease interventions.

Abstract Due to its characteristics, the internal crystal oscillator of the clock tester blurs the boundary between abnormal and normal features, resulting in poor feature extraction accuracy. This leads to the inability of recognition methods to comprehensively and accurately capture key information about abnormal features, resulting in poor recognition performance. Therefore, an automated identification method for abnormal operation status of internal crystal oscillators in clock testers is proposed. A CNN network architecture is designed to achieve intelligent state discrimination through convolutional layer feature extraction, pooling layer dimensionality reduction, and a Softmax classifier. Confidence optimization algorithms are combined to improve recognition accuracy, ultimately achieving automated identification of abnormal crystal oscillator operation status. The experimental results show that the proposed method for automatically identifying abnormal operating states of the internal crystal oscillator of the clock tester is completely consistent with the actual operating state and can accurately identify abnormal feature points. The proposed method has a higher accuracy in identifying three different types of abnormal states: slow frequency drift, sudden frequency changes, and phase jitter anomalies, than the comparative method, with better recognition performance, stronger adaptability, and higher accuracy.

The circadian clock plays a critical role in regulating various physiological processes, including gene expression, metabolic regulation, immune response, and the sleep-wake cycle in living organisms. Post-translational modifications (PTMs) are crucial regulatory mechanisms to maintain the precise oscillation of the circadian clock. By modulating the stability, activity, cell localization and protein-protein interactions of core clock proteins, PTMs enable these proteins to respond dynamically to environmental and intracellular changes, thereby sustaining the periodic oscillations of the circadian clock. Different types of PTMs exert their effects through distincting molecular mechanisms, collectively ensuring the proper function of the circadian system. This review systematically summarized several major types of PTMs, including phosphorylation, acetylation, ubiquitination, SUMOylation and oxidative modification, and overviewed their roles in regulating the core clock proteins and the associated pathways, with the goals of providing a theoretical foundation for the deeper understanding of clock mechanisms and the treatment of diseases associated with circadian disruption.

BackgroundPreventing oral infections, such as oral caries and periodontal disease, helps reduce the risks of various systemic diseases. In this study, the polysaccharide pullulan produced by the black yeast Aureobasidium pullulans was modified in combination with the cationic surfactant cetylpyridinium chloride (CPC) to create a local drug delivery system, and its antibacterial potential on oral bacteria was examined in vitro.MethodsPullulan was phosphorylated at the CH2OH residue of α6 in the maltotriose structure and mixed with CPC. Bacterial attachment of cariogenic Streptococcus mutans on hydroxyapatite plates (HAPs) treated with the phosphorylated pullulan (PP) and CPC compound (0.01% PP and 0.001– 0.03% CPC, and vice versa) was assessed by observing bacteria using a field emission scanning electron microscope (FE-SEM) and quantified through 16 S rRNA amplification via real-time polymerase chain reaction (PCR). Additionally, the quartz crystal microbalance (QCM) method was employed to evaluate the sustained release of CPC.ResultsPP-CPC compound maintained significant bactericidal activity even at 0.01%, which is one-fifth of the conventional applicable concentration of CPC. Additionally, a residual mixture was detected by the hydroxyapatite sensor of the crystal oscillator microbalance detector, suggesting an unknown molecular interaction that enables the sustained release of CPC after attachment to hydroxyapatite.ConclusionsThe combination of PP and CPC may contribute to the low concentration and effective prevention of oral infections, such as dental caries.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12903-025-06666-z.

In aerospace engineering, shock loads typically exhibit complex characteristics such as short duration, high magnitude, and a wide frequency range. These loads can easily damage spacecraft electronic components, potentially leading to mission failure. This paper proposes a reliability model based on stress–strength interference, considering the randomness of shock loads, as well as the dispersion in both the shock response spectrum (SRS) and material strength. A Weibull distribution model is used to represent the dispersion of stress and material strength, with the Weibull parameters determined using Bayesian estimation. Next, a crystal oscillator, commonly used in electronic and communication systems, is subjected to a shock experiment to verify the accuracy of the finite element model. The verified model is then subjected to time domain loads synthesized via wavelet analysis. The resulting maximum principal stress data, calculated under varying SRS conditions, are expanded and used for the Bayesian estimation of Weibull parameters. Finally, a stress–strength interference reliability model for electronic components is developed based on the Weibull distribution. This model is validated through reliability experiments on the crystal oscillator under different SRS amplitudes, confirming its feasibility. This method offers a valuable reference for the reliability analysis of spacecraft electronic components.

Precise time interval generation is a cornerstone of modern measurement, automation, and distributed control systems, particularly within Internet of Things (IoT) architectures. This paper presents the design, implementation, and evaluation of a low-cost and high-precision time interval generator based on Complementary Metal-Oxide Semiconductor (CMOS) logic counters (Integrated Circuit (IC) IC 7493 and IC 4017) and inverter-based crystal oscillators (IC 74LS04). The proposed system enables frequency division from 1 MHz down to 1 Hz through a cascade of binary and Johnson counters, enhanced with digitally controlled multiplexers for output signal selection. Unlike conventional timing systems relying on expensive Field-Programmable Gate Array (FPGA) or Global Navigation Satellite System (GNSS)-based synchronization, this approach offers a robust, locally controlled reference clock suitable for IoT nodes without network access. The hardware is integrated with Arduino and ESP32 microcontrollers via General-Purpose Input/Output (GPIO) level interfacing, supporting real-time timestamping, deterministic task execution, and microsecond-level synchronization. The system was validated through Python-based simulations incorporating Gaussian jitter models, as well as real-time experimental measurements using Arduino’s micros() function. Results demonstrated stable pulse generation with timing deviations consistently below ±3 µs across various frequency modes. A comparative analysis confirms the advantages of this CMOS-based timing solution over Real-Time Clock (RTC), Network Time Protocol (NTP), and Global Positioning System (GPS)-based methods in terms of local autonomy, cost, and integration simplicity. This work provides a practical and scalable time reference architecture for educational, industrial, and distributed applications, establishing a new bridge between classical digital circuit design and modern Internet of Things (IoT) timing requirements.

Excess caloric intake and insufficient physical activity are the two major drivers underlying the global obesity and type 2 diabetes mellitus epidemics. However, circadian misalignment of caloric intake and physical activity, as commonly experienced by nightshift workers, can also have detrimental effects on body weight and glucose homeostasis. We have previously reported that combined restriction of eating and voluntary wheel running to the inactive phase (i.e., a rat model for circadian misalignment) shifted liver and muscle clock rhythms by ~12 h and prevented the reduction in the amplitude of the muscle clock oscillation otherwise induced by light-phase feeding. Here, we extended on these findings and investigated how a high-fat diet (HFD) affects body composition and liver and muscle clock gene rhythms in male Wistar rats while restricting both eating and exercise to either the inactive or active phase. To do this, we used four experimental conditions: sedentary controls with no wheel access on a non-obesogenic diet (NR), sedentary controls with no wheel access on an HFD (NR-H), and two experimental groups on an HFD with simultaneous access to a running wheel and HFD time-restricted to either the light phase (light-run-light-fed + HFD, LRLF-H) or the dark phase (dark-run-dark-fed + HFD. DRDF-H). Consumption of an HFD did not alter the daily running distance of the time-restricted groups but did increase the running intensity in the LRLF-H group compared to a previously published LRLF chow fed group. However, no such increase was observed for the DRDF-H group. LRLF-H ameliorated light phase-induced disturbances in the soleus clock more effectively than under chow conditions and had a protective effect against HFD-induced changes in liver clock gene expression. Together with (our) previously published results, these data suggest that eating healthy and being active at the wrong time of the day can be as detrimental as eating unhealthy and being active at the right time of the day.

A Piezoelectric Square-Extensional Mode Oscillator for Mass Sensing in Liquid

ABSTRACTData center fires, often caused by continuous high‐load operations, result in significant losse. Liquid nitrogen has been proposed as an environmentally friendly cryogenic fluid for data center fire prevention. In this work, the effects of liquid nitrogen on typical integrated circuit chips in data centers were studied through experimental research and numerical simulation, focusing on the environmental parameter characteristics and the effects on structural and electrical performance under the liquid nitrogen actions. Results show that liquid nitrogen spraying has obvious cooling and inerting effects. Numerical simulations revealed that the temperature near the action point under spraying decreases to 0°C at 2.5 s at room temperature, indicating significant local cooling. Under high‐temperature combustion conditions, the temperature near the action point decreased to 28°C after 21 s, and the oxygen concentration in the experimental space fell below 5% after 60s, effectively inhibiting combustio. The actions of liquid nitrogen have less harmful effect on the chips, with primary impacts observed in some chips and plastic laminates. In addition, because of the poor temperature change characteristics of quartz, the input and output frequencies of the quartz oscillator are unstable, leading to slight deviations in the IV curve. This work provides valuable insights for the development and application of liquid nitrogen fire prevention technology in data centers, offering a critical reference for enhancing fire safety in such environments.

High-precision time-frequency systems are essential for low Earth orbit (LEO) navigation satellites to achieve real-time (RT) centimeter-level positioning services. However, subject to stringent size, power, and cost constraints, LEO satellites are typically equipped with oven-controlled crystal oscillators (OCXOs) as the system clock. The inherent long-term stability of OCXOs leads to rapid clock error accumulation, severely degrading positioning accuracy. To simultaneously balance multi-dimensional requirements such as clock bias accuracy, and frequency stability and phase continuity, this study proposes a linear quadratic Gaussian (LQG) frequency precision steering method that integrates a four-dimensional constraint integrated (FDCI) model and hierarchical weight optimization. An improved system error model is refined to quantify the covariance components (Σ11, Σ22) of the LQG closed-loop control system. Then, based on the FDCI model that explicitly incorporates quantization noise, frequency adjustment, frequency stability, and clock bias variance, a priority-driven collaborative optimization mechanism systematically determines the weight matrices, ensuring a robust tradeoff among multiple performance criteria. Experiments on OCXO payload products, with micro-step actuation, demonstrate that the proposed method reduces the clock error RMS to 0.14 ns and achieves multi-timescale stability enhancement. The short-to-long-term frequency stability reaches 9.38 × 10-13 at 100 s, and long-term frequency stability is 4.22 × 10-14 at 10,000 s, representing three orders of magnitude enhancement over a free-running OCXO. Compared to conventional PID control (clock bias RMS 0.38 ns) and pure Kalman filtering (stability 6.1 × 10-13 at 10,000 s), the proposed method reduces clock bias by 37% and improves stability by 93%. The impact of quantization noise on short-term stability (1-40 s) is contained within 13%. The principal novelty arises from the systematic integration of theoretical constraints and performance optimization within a unified framework. This approach comprehensively enhances the time-frequency performance of OCXOs, providing a low-cost, high-precision timing-frequency reference solution for LEO satellites.

After the interruption of the timing service, the increase in clock offset is a critical issue for the global navigation satellite system (GNSS)-disciplined oven-controlled crystal oscillator (OCXO). Current timekeeping methods for GNSS-disciplined OCXO have some drawbacks, such as high computational complexity, inadequate consideration of temperature effects, and insufficient separation of the impacts of temperature and aging. To address this issue, this study proposes a timekeeping method using a dual iterative algorithm. First, the external iteration separates the clock offset caused by temperature and aging. Then, the internal Gauss–Seidel iterative algorithm estimates the temperature and aging coefficients. During the timing service interruption phase, the model estimates and compensates for the frequency offset in real time using the coefficients. The proposed method demonstrates improved performance compared with OCXO in the free state and compensated by a second-order polynomial model, with better accuracy, drift rate, and long-term stability. The time offset is better than 4 μs over 24 h, representing an improvement of over 95% compared with the OCXO in the free state.

Thin layer sonoelectrochemistry is established when the wavelength 𝛌 of an ultrasonic transducer is comparable to the distance L between the sonicator and the electrode. A thin fluid layer of electrolyte separates the sonicator and electrode. Under these conditions, constructive interference is established to amplify sound pressure selectively at the electrode | electrolyte interface. A one dimensional model equation optimizes the choices of L relative to 𝛌 and identifies the build of energy as 1 kJ (mol s)-1 at the interface between aqueous electrolyte and a platinum electrode. Demonstrated experimentally with a low energy quartz crystal oscillator, interfacial kinetics are impacted without cavitation and without heating in the fluid layer. The model quantifies material impacts of the electrode metal and the electrolyte solvent. Amplification, characterized as Transmittance T, of sound pressure at the interface depends on 𝛌, speed of sound and kinematic viscosity of the solvent, and reflectivity at the electrode | electrolyte interface.Experiments are undertaken with a 41 kHz quartz crystal oscillator and platinum electrodes for five solvents and two redox probes. Cyclic voltammetry evaluates the rates (current) for 1 mM redox probes of ferric (Fe3+) nitrate and benzoquinone (Q). The electrolyte is tetrabutylammonium tetrafluoroborate (TBABF4) in the four nonaqueous solvents, tetrahydrofuran (THF), dimethylformamide (DMF), ethanol (EtOH), and 2-propanol. The aqueous electrolyte is 0.1 M H2SO4. Voltammograms are recorded before sonication (Pre-Sono), and at 0, 1, 5, and 10 minute intervals during sonication (Sono), and after sonication ceases (Post-Sono).Rate enhancement is reported as the highest currents normalized by the Pre-Sono peak currents. Enhancements for Fe3+ and Q are shown. In all cases except Fe3+ in water, highest currents are observed Post-Sono. Impacts of sonication persist for at least 10 minutes post-sonication.Table 1: Maximum Current Enhancements for 5 Solvents and 2 Probes (Fe3+ and Q). THFDMFWaterEtOH2-PropanolFe3+ 1.821.751.221.291.13Q2.17 0.96 ‡ 1.221.26-T at 41 kHz (106)1.140.921.001.150.57 ‡ Electron transfer kinetics for Q in DMF are rapid; sonication does not further increase the electron transfer rate.Peak currents for the nonaqueous solvents correlate well with Transmittance of the solvent, as anticipated by the model. The model is vetted by experimental outcomes. Optimized thin layer sonoelectrochemistry (TLS) experiments can be design based on the model.Acknowledgments and Disclosures: This work was supported by NSF CHE-1309366, ARO, and Iowa Energy Center 21 IEC 011. JL holds the rights toUS Patent 10,300,453.

The kinetics of the oxygen reduction reaction (ORR) are inherently slow, even at platinum electrodes. In low temperature, H2|O2 fuel cells, efficiency is diminished relative to the thermodynamics by ∼25 % because of poor interfacial O2 kinetics. Rather than address slow ORR kinetics by manipulating the chemical composition of the electrocatalyst, physical manipulation of the energy at the electrode | electrolyte interface is effective.In thin layer sonoelectrochemistry (TLS), constructive interference of sound pressure waves deposits energy selectively at the electrode | electrolyte interface. The ultrasonic oscillator and electrode are separated by a thin layer of electrolyte, about 1 cm thick for a 20 to 40 kHz oscillator. In a well configured TLS cell, interfacial energy is deposited at ∼1 kJ (mol s)-1. Because of constructive interference in TLS, no cavitation and no heating of the electrolyte is observed. Experiments are undertaken with a simple 41 kHz quartz crystal oscillator (QCO). QCOs are voltage driven with minimal energy input. As the system is sonicated, energy deposited at the electrode interface impacts kinetics of slow reactions. Typically, impacts of sonication persist for greater than 10 minutes after sonication ceases.TLS impacts a variety of reactions that include ORR at platinum and removal of oxide layers on metals such as platinum. Cyclic voltammograms were recorded in a TLS cell that contained 0.1 M aqueous nitric acid. The standard heterogeneous electron transfer rate k0 for O2 reduction increases ∼50 fold under TLS conditions.After 20 cyclic voltammetric sweeps over 270 seconds, the Pt oxide peak current is 66 𝜇A without sonication; with sonication, peak current is 19 𝜇A. At 270 s, sonication delivered ~ 270 kJ mol-1 to the electrode | electrolyte interface. TLS impacts slow interfacial rates by depositing sound pressure energy immediately at the electrode | electrolyte interface. This is a physical rather than a chemical means of electrocatalysis._Acknowledgements and Disclosure. This work was supported by NSF CHE-1309366. J.Leddy holds the rights to US Patent 10,300,453.

Sonochemistry is typically undertaken in bulk fluids where irradiation with ultrasound generates cavitation. On collapse of cavitation voids, high temperature and pressure excursions deposit energy at at the narrow interface between the fluid and the void. Reaction rates increase as the fluid heats, but cavitation introduces turbulence that disrupts transport and obscures visibility in the fluid. Cavitation can pit surfaces. Because sonochemistry in bulk fluids heats the fluid indiscriminately, energy input from ultrasonic transducers is high.Ultrasound has a wavelength 𝛌 of about a centimeter. Sonochemistry undertaken in a thin fluid layer of comparable thickness L establishes constructive interference. For an electrode separated from an ultrasonic transducer by distance L, several advantages accrue. Constructive interference builds energy selectively at the electrode | electrolyte interface. In aqueous electrolytes with platinum electrodes, energy builds at the interface at about 1 kJ (mol s)-1. For every 100 s of irradiation, 100 kJ (mol)-1 is deposited at the interface. No cavitation is observed.Because energy is selectively deposited at the interface, the bulk fluid does not heat.The selective deposition of energy at the interface decreases the power input to the transducers. Systems are demonstrated with quartz crystal oscillators (QCOs). Input energy is low as QCOs are driven by voltage with negligible current. QCOs approach 98 % transduction efficient. No turbulence is induced. Transport fields are not disrupted and fluids in the thin layer remain transparent. Voltammetric morphology is characterized by voltammetric diagnostics established for quiescent electrolytes.Heterogeneous electron transfer rates are increased under thin layer sonoelectrochemical conditions, provided the interfacial rate is not fast in quiescent solutions. For example, the electron transfer rate of Ru(bpy)3 3+|2+ is unchanged on sonication, but the rate of electron transfer for Fe3+|2+ increases substantially.After sonication ceases, impacts of sonication typically persist for at least several minutes post-sonication. A model equation is developed. The equation describes how L can be optimized for a given 𝛌; how transmittance (amplification) correlates with energy imparted to the electrode | electrolyte interface; and how the properties of the electrode material and the electrolyte impact sound pressure (energy) at the electrode | electrolyte interface. Experimental examples are provided.Acknowledgments and Disclosures: This work was supported by NSF CHE-1309366. JL holds the rights to US Patent 10,300,453.