bluuebunny/crossref_metadata_2025 huggingface dataset:
Glycine synthesis from nitrate and glyoxylate mediated by ferroan brucite: An integrated pathway for prebiotic amine synthesis
Authors: Chimiak L. , Hara E. , Sessions A. , Templeton A.S.
Published: October 2024

Amino acids are present in all known life, so identifying the environmental conditions under which they can be synthesized constrains where life on Earth might have formed and where life might be found on other planetary bodies. All known abiotic amino acid syntheses require ammonia, which is only produced in reducing and neutral atmospheres. Here, we demonstrate that the Fe-bearing hydroxide mineral ferroan brucite [Fe
0.33
,Mg
0.67
(OH)
2
] can mediate the reaction of nitrate and glyoxylate to form glycine, the simplest amino acid used in life. Up to 97% of this glycine was detected only after acid digestion of the mineral, demonstrating that it had been strongly partitioned to the mineral. The dicarboxylic amino acid 3-hydroxy aspartate was also detected, which suggests that reactants underwent a mechanism that simultaneously produced mono- and dicarboxylic amino acids. Nitrate can be produced in both neutral and oxidizing atmospheres, so reductive amination of nitrate and glyoxylate on a ferroan brucite surface expands origins of life scenarios. First, it expands the environmental conditions in which life’s precursors could form to include oxidizing atmospheres. Second, it demonstrates the ability of ferroan brucite, an abundant, secondary mineral in serpentinizing systems where olivine is partly hydrated, to mediate reductive amination. Finally, the results demonstrate the need to consider mineral-bound products when analyzing samples for abiotic amino acid synthesis.
Modulating metal-centered dimerization of a lanthanide chaperone protein for separation of light lanthanides
Authors: Larrinaga Wyatt B. , Jung Jonathan J. , Lin Chi-Yun , Boal Amie K. , Cotruvo Joseph A.
Published: October 2024

Elucidating details of biology’s selective uptake and trafficking of rare earth elements, particularly the lanthanides, has the potential to inspire sustainable biomolecular separations of these essential metals for myriad modern technologies. Here, we biochemically and structurally characterize
Methylobacterium
(
Methylorubrum
)
extorquens
LanD, a periplasmic protein from a bacterial gene cluster for lanthanide uptake. This protein provides only four ligands at its surface-exposed lanthanide-binding site, allowing for metal-centered protein dimerization that favors the largest lanthanide, La
III
. However, the monomer prefers Nd
III
and Sm
III
, which are disfavored lanthanides for cellular utilization. Structure-guided mutagenesis of a metal-ligand and an outer-sphere residue weakens metal binding to the LanD monomer and enhances dimerization for Pr
III
and Nd
III
by 100-fold. Selective dimerization enriches high-value Pr
III
and Nd
III
relative to low-value La
III
and Ce
III
in an all-aqueous process, achieving higher separation factors than lanmodulins and comparable or better separation factors than common industrial extractants. Finally, we show that LanD interacts with lanmodulin (LanM), a previously characterized periplasmic protein that shares LanD’s preference for Nd
III
and Sm
III
. Our results suggest that LanD’s unusual metal-binding site transfers less-desirable lanthanides to LanM to siphon them away from the pathway for cytosolic import. The properties of LanD show how relatively weak chelators can achieve high selectivity, and they form the basis for the design of protein dimers for separation of adjacent lanthanide pairs and other metal ions.
Soil viral–host interactions regulate microplastic-dependent carbon storage
Authors: Wang Lu , Lin Da , Xiao Ke-Qing , Ma Li-Juan , Fu Yan-Mei , Huo Yu-Xin , Liu Yanjie , Ye Mao , Sun Ming-Ming , Zhu Dong , Rillig Matthias C. , Zhu Yong-Guan
Published: October 2024

Microplastic is globally regarded as an important factor impacting biogeochemical cycles, yet our understanding of such influences is limited by the uncertainties of intricate microbial processes. By multiomics analysis, coupled with soil chemodiversity characterization and microbial carbon use efficiency (CUE), we investigated how microbial responses to microplastics impacted soil carbon cycling in a long-term field experiment. We showed that biodegradable microplastics promoted soil organic carbon accrual by an average of 2.47%, while nondegradable microplastics inhibited it by 17.4%, as a consequence of the virus–bacteria coadaptations to the microplastics disturbance. In the relevant functional pathways, nondegradable microplastics significantly (
P
< 0.05) enhanced the abundance and transcriptional activity related to complex carbohydrate metabolism, whereas biodegradable microplastics significantly (
P
< 0.05) promoted functions involved in amino acid metabolism and glycolysis. Accordingly, viral lysis enhanced in nondegradable microplastics treatments to introduce more complex organic compounds to soil dissolved organic matters, thus benefiting the oligotrophs with high carbon metabolic capabilities in exploitation competition. In contrast, biodegradable microplastics enriched viral auxiliary metabolic genes of carbon metabolism through “piggyback-the-winner” strategy, conferring to dominant copiotrophs, enhanced substrate utilization capabilities. These virus–host interactions were also demonstrated in the corresponding soil plastisphere, which would alter microbial resource allocation and metabolism via CUE, affecting carbon storage consequently. Overall, our results underscore the importance of viral–host interactions in understanding the microplastics-dependent carbon storage in the soil ecosystem.
Hydroxyl radical oxidation of chemical contaminants on indoor surfaces and dust
Authors: Fahy William D. , Gong Yufeng , Wang Shenghong , Zhang Zhizhen , Li Li , Peng Hui , Abbatt Jonathan P.D.
Published: October 2024

Humans are widely exposed to semivolatile organic contaminants in indoor environments. Many contaminants have long lifetimes following partitioning to the large surface reservoirs present indoors, which leads to long exposure times to gas-phase oxidants and multiphase chemistry. Studies have shown selective multiphase oxidation of organics on indoor surfaces, but the presence of hydroxyl radicals with nonselective reactivity and evidence of multiphase OH radical reactivity toward common indoor contaminants indicates that there may be additional unknown transformation chemistry indoors. We screened genuine indoor samples for 60 OH radical oxidation products of the common plasticizer and endocrine-disrupting contaminant bis(2-ethylhexyl) phthalate (DEHP) identified in laboratory experiments using nontargeted high-resolution mass spectrometry. At least 30 and 10 of these products are observed in indoor dust and DEHP films exposed to ambient indoor conditions, respectively, indicating that multiphase OH reactions occur indoors. Using the PROTEX model and a multimedia indoor chemical fate model, we demonstrate that these products have long indoor lifetimes and cause a higher potential for human exposure than DEHP. Some of these products are more active endocrine disruptors than DEHP itself, but most have unknown toxicities. Coexposure to all oxidation products will likely have an additive effect, leading to higher human health risks from indoor organic contaminants than previously thought. Due to the nonselective reactivity of OH radicals, it is likely that most indoor contaminants follow similar chemistry, and further study is needed to understand the prevalence and human health implications of such multiphase chemistry.
Individual differences in information demand have a low dimensional structure predicted by some curiosity traits
Authors: Jach Hayley K. , Cools Roshan , Frisvold Alex , Grubb Michael A. , Hartley Catherine A. , Hartmann Jochen , Hunter Laura , Jia Ruonan , de Lange Floris P. , Larisch Ruby , Lavelle-Hill Rosa , Levy Ifat , Li Yutong , van Lieshout Lieke L.F. , Nussenbaum Kate , Ravaioli Silvio , Wang Siyu , Wilson Robert , Woodford Michael , Murayama Kou , Gottlieb Jacqueline
Published: October 2024

To understand human learning and progress, it is crucial to understand curiosity. But how consistent is curiosity’s conception and assessment across scientific research disciplines? We present the results of a large collaborative project assessing the correspondence between curiosity measures in personality psychology and cognitive science. A total of 820 participants completed 15 personality trait measures and 9 cognitive tasks that tested multiple aspects of information demand. We show that shared variance across the cognitive tasks was captured by a dimension reflecting directed (uncertainty-driven) versus random (stochasticity-driven) exploration and individual differences along this axis were significantly and consistently predicted by personality traits. However, the personality metrics that best predicted information demand were not the central curiosity traits of openness to experience, deprivation sensitivity, and joyous exploration, but instead included more peripheral curiosity traits (need for cognition, thrill seeking, and stress tolerance) and measures not traditionally associated with curiosity (extraversion and behavioral inhibition). The results suggest that the umbrella term “curiosity” reflects a constellation of cognitive and emotional processes, only some of which are shared between personality measures and cognitive tasks. The results reflect the distinct methods that are used in these fields, indicating a need for caution in comparing results across fields and for future interdisciplinary collaborations to strengthen our emerging understanding of curiosity.
Navigating Social, Environmental, and Economic Complexities of Insect Farming to Contribute to Sustainable Agrifood Systems
Authors: Barragán-Fonseca Karol B.
Published: October 2024

Insect farming is increasingly recognized as an important component of sustainable agrifood systems that provide a variety of social, environmental, and economic benefits. This text explores the complexities of insect farming which must be considered to maximize its potential and thereby contribute to global sustainability goals. It explores diverse strategies for evaluating and optimizing the socio-economic and environmental benefits of insect farming and addresses insects’ diverse roles in circular food systems and their potential contributions to achieving the UN Sustainable Development Goals. By exploring the particularities of insect farming which vary according to the particular context of each region, this text highlights the ways in which local ecological, socio-economic, and cultural factors influence the outcomes of insect farming initiatives. The case exercises included are aimed at providing readers with an understanding of the role of insect farming in sustainable agriculture. Combining theoretical insights with practical examples, it provides a framework for developing locally adapted insect farming practices that maximize the benefits while minimizing the risks of this type of farming. The case exercises presented are aimed at providing students with experience in developing plans for insect farming scenarios that consider key social, environmental, and economic aspects related to sustainable insect production.

Information

© The Author 2024
Low-intensity pulsed ultrasound ameliorates insulin resistance in type 2 diabetes mice via promoting glucagon-like peptide-1 release
Authors: Wang Huan , He Min , Bat Erdene Badamgarav , Dong Jingsong , Ta Dean
Published: October 2024

Glucagon-like peptide-1 (GLP-1) is a hormone secreted by intestinal L-cells. It regulates glucose levels by boosting insulin secretion, inhibiting glucagon release, and preventing β-cell death. GLP-1 is increasingly used in managing type 2 diabetes mellitus (T2DM). This study assessed the effectiveness of low-intensity pulsed ultrasound (LIPUS), a non-pharmacological intervention, in enhancing insulin resistance in diabetic mice by stimulating GLP-1 release. T2DM was induced in C57BL/6J mice through a high-fat diet and streptozotocin injection. Mice were divided into Control, T2D-sham and T2D-LIPUS groups. The T2D-LIPUS group received LIPUS treatment with a frequency of 1MHz, intensity of 120mW/cm2, and duty cycle of 20%for 20 minutes/day, 5 days/week for 4 weeks. Glucose tolerance and insulin resistance were measured through tests. Pancreatic histology and GLP-1 expression in serum were evaluated. Results showed that T2DM increased insulin resistance, but LIPUS treatment alleviated it. GLP-1 levels significantly increased in the T2D-LIPUS group compared to the T2D-sham group, approaching the control group’s level. LIPUS also reduced apoptosis of islet β cells. These findings suggest that LIPUS stimulation of the intestine can enhance islet β-cell activity through GLP-1 regulation of the gut-pancreas axis, mitigating insulin resistance in T2DM.
Complex Pseudo 3D Auto-Correlation Network for High-Quality Single-Angle Plane Wave Imaging
Authors: Ren Chujian , Qu Xiaolei , Wang Zihao , Wei Xiaorui , Fan Shangchun , Zheng Dezhi , Wang Shuai , Xing Weiwei , Zhao Wanchen
Published: October 2024

Deep learning has shown potential as an effective beamformer for improving the image quality of plane wave imaging (PWI). But most existing deep learning methods cannot directly handle the complex in-phase and quadrature (IQ) data. And noise in ultrasound signals would significantly damage the performance of regular convolution networks. To address these challenges, we proposed the Complex Pseudo 3D Auto-Correlation Network (CP3AN) which combined complex convolution and pseudo 3D auto-correlation blocks (P3AB) to directly map delayed IQ data from 0° plane wave into PWI pixels. The complex convolution could fully utilize the envelope and phase information of IQ data, while the P3AB used 1D convolution to extract noise in channel and space dimensions, allowing the network to prioritize valid signals with extremely low computational cost. We evaluated the performance of CP3AN through numerical simulations, phantom experiments, and in-vivo experiments, which showed comparable metrics with minimum variance (MV), including contrast (CR), contrast-to-noise ratio (CNR), generalized contrast-to-noise ratio (GCNR), lateral, and axial full-width half maximum (FWHM) at -9.60 dB, 1.12, 0.65, 319 um, and 344 um, respectively. The CP3AN achieved a low computational cost of 0.11 M floating-point operations (FLOPs), significantly lower than the MV or other compared deep learning-based methods. Our proposed method provided a promising solution for improving single-angle PWI imaging, particularly in situations where high frame rates are necessary.
Adaptive Filtering of Pulse Waves for the Improvement of Ultrasonic Carotid LPWV Estimation Method
Authors: Deng Li , Zhang Yufeng , Xia Dawen , Yu Shaomei , Lu Youjun , Wei Jiayin , Zhang Jiajia , Chen Zhi , Song Wenxia
Published: October 2024

Aiming at promoting the accuracy of the ultrasonic carotid local pulse wave velocity (LPWV) estimation, an adaptive filtering of pulse waves for the ultrasonic carotid transit time-based LPWV estimation is proposed. First, the upstroke of pulse wave (PWU) is decomposed into time-frequency domain adaptively by an empirical wavelet transform (EWT) method, and then the noises (include the quantization noise and reflected wave in pulse wave) are picked up with predetermined threshold by multiple EWT decompositions. The proposed adaptive filtering of pulse waves for the LPWV estimation is quantitatively evaluated by an ultrasound simulation model for three age groups. Results show that the mean error of EWT-based PWU filtering are just 3.49 %, and the PWV estimation error for the three age groups are 5.77 ± 2.45 %, 4.54 ± 3.46 % and 12.24 ± 5.36 %, respectively by the EWT-based PWU filtering, which is lower than that by SG filtering. The results could be expected to provide theoretical basis and technical support for the early quantitative evaluation of local carotid vascular elasticity in clinic.
A Mumford-Shah Model-based Method for Inpainting Markers in Ultrasound Images
Authors: Xing Wenyu , Yu Ming , Liu Xin
Published: October 2024

During ultrasound diagnosis in clinics, clinicians often mark the lesion area, resulting in the presence of unnecessary objects in the collected ultrasound images. These markers potentially affect subsequent image analysis. To address this problem, we proposed an image inpainting method that combines image processing with Mumford-Shah algorithm to remove markers from ultrasound images. The proposed method consists of two parts. First, the input ultrasound images were processed by several image processing algorithms, including contrast enhancement, image binarization, edge detection, hole filling, and connected domain marking. These algorithms were combined to extract the mask of the manual marker in the ultrasound images. Second, the original ultrasound images and mask images were put into the Mumford-Shah model to implement ultrasound image inpainting by minimizing the following energy functional. The continuous iteration of Euler-Lagrange equation was employed to update the iteration item. If the difference between the two output results was less than the pre-set threshold, the output result could be regarded as the repaired ultrasound image. Experimental results show that the designed image processing method accurately extracted the binary mask, whether they are colourful or binary, number or line in ultrasound images. Meanwhile, the improved Mumford-Shah model effectively implemented the ultrasound image inpainting, with the accuracy of 96.55%. Therefore, the proposed method can be used to remove unnecessary objects in ultrasound images, which is beneficial to improve the accuracy of the artificial intelligence model.
Photoacoustic tracking of photo-magnetically powered nanoparticles for cancer therapy
Authors: Li Jiayan , Xu Chang , Chen Yingna , Cao Junmei , Ye Wanli , Cheng Yu , Cheng Qian
Published: October 2024

The in vivo propulsion and monitoring of nanoparticles (NPs) have received tremendous achievements in the past decade. Developing functional NPs that can be efficiently manipulated inside the human body with a non-invasive tracking modality is critical to clinical translation. This study synthesized a photo-magnetically powered nanoparticle (PMN) with a Fe3O4 core and gold spiky surface. The Au-nanotips ensure PMNs have a strong light absorption in the second near-infrared (NIR) window and produce outstanding photoacoustic signals. The Bio-transmission electron microscopy and simulation results prove that the assembly of PMNs under a magnetic field further enhances the photothermal conversion in cells, contributing to the reduction of ambient viscosity. Photoacoustic imaging (PAI) realized real-time monitoring of PMN movements and revealed that laser plus magnetic coupling could improve intratumoral distribution and retention. The proposed methods exhibit excellent potential for the clinical research of cancer nanotherapies.
An Energy Efficient Transmission Mechanism based on Optimal Relay Distance for Underwater Acoustic Sensor Networks
Authors: Sun Shiqiang , Sun Ning , Han Guangjie
Published: October 2024

Due to the limited resources and energy of communication in underwater acoustic sensor network (UASN), there are many challenges in designing energy-efficient and reliable media access control (MAC) protocols for UASN. This paper proposes an energy-efficient media access control (MAC) protocol with dynamic transmission range control (TRC), referred to as TRA-MAC. The protocol provides an adaptive, multi-hop and energy-saving solution for underwater sensor network communication. The protocol dynamically adjusts the transmission power of the node according to the distance between the source node and the destination node, and has the ability to adapt to network conditions. Simulation results show that compared with Slotted Aloha, the proposed adaptive relay node selection mechanism increases the energy efficiency by 43.07%, the network throughput by 46.6%, and the end-to-end delay is greatly reduced. Compared with Slotted FAMA, it has more significant advantages.
Mechanical properties and damage characterization of 310S steel using laser ultrasonic inspection under extreme temperature condition
Authors: Li Junrong , Meng Jiajian , Hu Yong , Zhang Jianhai
Published: October 2024

To evaluate the mechanical properties of 310S stainless steel under extreme working conditions, and realize the damage characterization function, in this study, the longitudinal wave and Rayleigh wave of materials are measured by the method of coaxial inspection on reverse surface and ipsilateral ectopic inspection, respectively, and surface cracks and internal voids are detected by the scanning laser source technology and transmission scanning detection, respectively. The detection methods are designed based on the energy distribution characteristics of Rayleigh wave and longitudinal waves in laser ultrasound. The laser ultrasonic detection systems coupled with a temperature loading device (high temperature: vacuum chamber; low temperature: refrigerating chamber) developed by the laboratory enable on-site monitoring of laser ultrasonic technology in harsh environments. Experimental results demonstrate that the error in mechanical properties (elastic modulus, shear modulus, Poisson ratio) is less than 5% over a wide temperature range (-180-1000°C). At 1000°C, surface cracks wider than 0.5mm and deeper than 1.9mm as well as internal hole defects larger than 1.0mm can be detected with an error rate below 5%.
Ultrasonic guided wave phased array based on reconstructed pulse-echo signals from phase information
Authors: Li Xuan , Xiang Yanxun , Liu Lishuai , Xuan Fu-Zhen
Published: October 2024

Aiming at the inherent dispersion characteristics of ultrasonic guided waves and the problems of gratings and side lobes in classical total focusing method (TFM) imaging algorithms, this paper proposes a full focus imaging algorithm based on reconstruct signals from phase information. Utilizing the numerical solution of the dispersion curve in the wavenumber domain, the time domain signal of Lamb wave is propagated backward to revise the changes in waveform shape caused by dispersion, and the flight time of the pulse-echo is eliminated simultaneously. The phase of pulse-echo after dispersion compensation should be consistent with the excitation signal. And the pulse-echo should have a large waveform correlation coefficient with the excitation signal. For each imaging point, dispersion compensation for all collected signals is respectively implemented so that the sign coherence factor (SCF) and the waveform correlation factor (WCF) between pulse-echo and excitation waveform can be extracted to reconstruct scattering signals. The reconstructed signals only contain information about the pulse-echo from defect. TFM imaging of the reconstructed signal can effectively suppress the grating side lobes of classical TFM imaging and improve the signal-to-noise ratio (SNR).
Equivalent tensile elastic modulus measurement of cross-ply composite plates using S1 mode of Lamb wave
Authors: Zeng Jiaqi , Liu Yaolu , Jiang Youqiang , Wang Yunlin , Hu Ning
Published: October 2024

This paper proposes a simple and effective Lamb wave-based measurement method for the elastic moduli of cross-ply composite plates with large thickness, considered equivalent to a single-layer orthotropic plate with nine independent elastic constants. Due to the low-frequency signals required for measuring large thickness plates and the large wavelength of the low-frequency signals, the size of composite plates is highly required. Therefore, it is considered to use the first order symmetric (S1) mode wave to increase the signal frequency and reduce the wavelength. The effects of elastic constants on the phase velocities of the S1 mode are investigated. The phase velocity of the S1 mode depends only on the equivalent tensile elastic modulus and in-plane Poisson’s ratio in the low-dispersive frequency-thickness product regime. Moreover, the in-plane Poisson’s ratio of cross-ply laminates changes sufficiently small to neglect its effect on the phase velocities of the S1 mode. Therefore, the tensile elastic moduli of the cross-ply laminated plates can be estimated using the S1 mode, and the mapping relations between the phase velocities of S1 mode and the elastic moduli are established. The proposed approach has been numerically and experimentally tested on cross-ply glass fiber reinforced laminates with large thickness, and validated by theoretical values and conventional tensile tests.
Application of coded excitation in the Rayleigh wave detection of aluminum plates with narrow-magnet EMAT
Authors: Lin Junjie , Guo Xinfeng , Liu Lishuai , Xiang Yanxun , Xuan Fu-Zhen
Published: October 2024

The poor generation efficiency causes the low signal-to-noise ratio (SNR) of the electromagnetic acoustic transducers (EMATs). The magnetic fields at the edges of the magnet are fully utilized in the narrow-magnet EMAT to generate Rayleigh waves of higher amplitudes than the conventional EMAT. This paper applies the coded excitation technology to narrow-magnet EMAT to further improve the SNR and the lift-off performance in aluminum plate detection. The main phase encoding methods are Barker code and Golay code. Compared with the conventional tone-burst excitation method, both coded excitation technologies can effectively improve the SNR of the Rayleigh wave. Theoretically, the received Rayleigh waves using the Golay-coded excitation method have no sidelobe, which is different from the case using the Barker code. Hence the Golay-coded excitation achieves higher SNR in the received ultrasonic waves. In addition, the application of the Golay-coded excitation can also effectively improve the lift-off performance of the narrow-magnet EMAT.
Guided elastic wave propagation in elastic metamaterial plate with periodic array of interfacial crack-like voids
Authors: Golub Mikhail V. , Khanazaryan Artur D. , Kanishchev Kirill K. , Moroz Ilya A. , Fomenko Sergey I. , Arsenov Mikhail A. , Wang Yanzheng , Zhang Chuanzeng
Published: October 2024

A special kind of elastic metamaterials with periodic unit-cells composed of two layers with internal crack-like voids situated at the interfaces between two neighboring sub-layers is studied. To investigate experimentally guided waves propagation in EMMs with arrays of voids, several specimens with periodic arrays of crack-like voids have been manufactured using additive manufacturing techniques. The elastic waves have been excited by a rectangular piezoelectric transducer bonded at the surface of the specimen, while the wave-fields on the surface of the EMM specimen are measured by a laser Doppler vibrometer. The dispersion characteristics are investigated using the matrix pencil method and band-gaps are observed experimentally.
Padé acoustoporoelasticity finite-difference simulation of elastic wave propagation in prestressed porous media
Authors: Zheng Haochen , Fu Li-Yun , Yang Haidi , Fu Bo-Ye , Deng Wubing
Published: October 2024

Acoustoelasticity has significant implications in seismic exploration, enabling the inference of geological structures and the properties of oil and gas reservoirs through rock physical acoustoelastic parameters, as well as elucidating the propagation of elastic waves in subsurface rocks. In traditional acoustoporoelastic numerical simulations, third-order elastic constants are derived from the Taylor expansion of the strain energy function. However, under conditions of high effective stress, the Taylor approximation can lead to divergent elastic wave velocities. To address this limitation, we propose employing the Padé approximation for the expansion of the strain energy function, as it provides superior accuracy compared to the Taylor approximation. By calibrating the Padécoefficients using experimental data for various rock types, the resultant acoustoelastic constants exhibit a reasonable theoretical limit on elastic wave velocities as effective stress increases. This method allows for a more precise characterization of velocity variations with stress, especially under high-pressure conditions. The acoustoporoelasticity numerical simulation is mainly limited to the 2D cases, so we consider confining prestressed mode in the 3D cases.
Numerical studies of bubble pulsation in viscoelastic media under dual-frequency ultrasound
Authors: Wang Yu , Chen Dehua , Li Jiahui
Published: October 2024

Dual-frequency ultrasound methods can be used to detect microbubbles in biological tissues, and bubble pulsation under acoustic waves is significant for the detection results. In this study, the dynamic equation of bubbles in viscoelastic media was numerically solved and the instantaneous radius of bubbles under single-frequency and dual-frequency ultrasound were compared. The maximum values of the bubble radii at different incident frequencies were calculated. In addition, the effects of the bubble equilibrium radius and the shear modulus of the surrounding medium on the bubble oscillations are investigated. The results show that the bubble pulsation under dual-frequency ultrasound is more complex than that under single-frequency. The elasticity of the media affects the resonant frequency of the bubble and the frequency increases with the shear modulus. When the frequency of the incident wave is equivalent to the resonant frequency of the bubble, the amplitude of the bubble oscillation radius achieves a maximum. Moreover, the spectrum of the bubble oscillation radius is correlated with both the bubble equilibrium radius and the shear modulus of the surrounding medium.
Numerical Investigation of Ultrasound-Induced Bubble Motion and Coalescence
Authors: Zhang Yonglong , Cao Shunxiang
Published: October 2024

Ultrasound-induced bubble motion and coalescence can be a unique approach to neutralize cavitation clouds in many biomedical applications. However, the detailed mechanisms of bubbles’ collective behaviours have not been fully understood. This work aims to develop an Eulerian-Lagrangian computational framework to simulate the bubble motion and coalescence driven by an ultrasound field. Specifically, the bubbles are modeled as oscillating spheres governed by the Keller-Miksis equation and are tracked as Lagrangian particles moving through the background Eulerian mesh. Several forces that drive bubble dynamics are modeled, including primary and secondary Bjerknes forces, drag force. As two bubbles contacting with each other, coalescence may happen and the film drainage model is applied to simulate the process. Using the new framework, the effects of pulse amplitude, frequency and length on the motion and coalescence of bubbles with different sizes and void fraction are investigated. The new knowledge can be applied to identify the optimal pulse parameters to better control the bubble motion and coalescence, improving the effectiveness of relevant ultrasound techniques.
The numerical reconstruction methods for characterizing defects by full matrix data using an ultrasonic array
Authors: Cao Ziyi , Shi Fangfang
Published: October 2024

This study introduces ultrasonic imaging and inversion methods for the quantitative characterization of crack defects. The Total Focusing Method (TFM) is a high-precision ultrasonic imaging method, but it may produce length errors when used for large-angle defect detection. An SV transverse wave TFM method is introduced, significantly reducing length errors in a 60° crack to 8.31%. However, the ultrasonic image method is influenced by factors like array position, limiting its practicality. To overcome this limitation, the study proposes an inversion method using the subarray scattering coefficient matrix, which is more stable and less sensitive to array positioning. Comparative analysis with finite element simulations and experiments indicates optimal array positions associated with different methods. At these positions, both methods yield angular characterization errors for the 60° crack of less than 1%, validating the proposed techniques for non-destructive testing applications.
Electric Calibration for Heterodyne Laser-Doppler Vibrometers at High Frequency
Authors: Qian Feiming , Xing Guangzhen , Yang Ping , Zou Limin , Hu Pengcheng
Published: October 2024

Calibration for Heterodyne Laser-Doppler Vibrometers (HLDV) is important for its accuracy and reliability. ISO 166063-41 provides primary and secondary calibration specifications for HLDV only in the frequency range from 0.4Hz to 50kHz, which can’t meet current demand for higher frequency. To be specific, the vibration exciter limits calibration frequency to a higher range. With this in mind, the electric calibration is presented. As a substitution method, the high precision arbitrary waveform generator replaces the optical module to output synthesized Doppler heterodyne signals which can cover all the required frequency. In addition, a commercial demodulator is used for calibration in the frequency range up to 1MHz. By theoretical introduction and experimental verification, this method offers significant improvement and thus potential over existing methods for HLDV calibration.
Design and implementation of 1GHz bandwidth SAW chirp transform spectrometer
Authors: Hu Baifan , Liu Mengwei , Ru Penglei , Gong Junjie , Wang Wen
Published: October 2024

Because of its low power consumption and high stability, the surface acoustic wave (SAW) chirp transform spectrometer (CTS) has been widely applied in deep space missions for exploring space beyond Earth. In this paper, a comprehensive description of a new CTS with 1GHz bandwidth and 100kHz spectral resolution is presented. This spectrometer is implemented in a combination of digital and analog. The Chirp signal with a bandwidth of 2 GHz is generated by DDS as the expander and a SAW chirp filter with 1GHz bandwidth and 10μs dispersion is used as the compressor. The system is completely constructed for the back-end data acquisition and processing part of the CTS. Aiming at the detection demand and acquisition problem of weak signals in deep space in the field of deep space exploration, the pulse integration technique is used to improve the detection capability of the Chirp transform spectrometer for weak signals, and the synchronization and real-time implementation of the high-speed system in the process of pulse integration are discussed and designed in detail. The pulse width of the accumulated spectrum is about 1.2ns, and the corresponding frequency resolution is 120kHz, which is close to the theoretical value.
Longitudinal validity of the Hyperhidrosis Quality of Life Index (HidroQoL©) in a phase IIIb clinical trial population with hyperhidrosis: responsiveness and meaningful change
Authors: Donhauser Theresa , Gabes Michaela , Masur Clarissa , Kamudoni Paul , Salek Sam , Abels Christoph , Apfelbacher Christian
Published: October 2024

Background

The Hyperhidrosis Quality of Life Index (HidroQoL©) is a well-developed patient-reported outcome measure assessing the quality of life impacts in hyperhidrosis (HH), which has proven very good measurement properties, such as structural validity and internal consistency.

Objectives

We aimed to investigate responsiveness over time and estimate values for meaningful within-person change (MWPC) towards symptom improvement for different measurement timepoints (4 and 12 weeks), extending the existing validity evidence in patients with primary axillary HH.

Methods

Data (from a phase IIIb clinical trial) were collected at baseline, and at weeks 4, 8, 12, 28, 52 and 72. For the assessment of responsiveness, HidroQoL change scores were correlated with corresponding change scores of the Hyperhidrosis Disease Severity Scale (HDSS), the Dermatology Life Quality Index (DLQI) and gravimetric sweat production based on a priori formulated hypotheses. Furthermore, we tested whether the different HDSS change score groups differed significantly from each other over time and whether the HidroQoL was sensitive towards these group differences over time. This was extended by the calculation of matched-pair tests and effect sizes to test significance for each change group separately. For the estimation of MWPC thresholds towards symptom improvement, different anchor-based and integrated approaches were used.

Results

In total, the sample comprised 357 patients with primary axillary HH. For the assessment of responsiveness, five out of 14 a priori hypotheses regarding the correlation of the change scores could be confirmed, whereas the rejected hypotheses differed only marginally from the expected values. Furthermore, regarding responsiveness, the HidroQoL showed sensitivity towards symptom improvement at each measurement timepoint. Effect sizes were large as expected (d ≥ 0.806). MWPC thresholds towards symptom improvement were proposed for two measurement timepoints: 5 (week 4) and 6 (week 12). Increasing MWPC values over time were observed.

Conclusions

This study extends the evidence for the longitudinal validity of the HidroQoL© up to 72 weeks and proposed MWPC thresholds for different time intervals (4 and 12 weeks) after baseline, aiding interpretability. Results concur with findings from previous validation studies.
Comment on “A not-so healthy glow: a qualitative analysis of sunbed content and viewer engagement on social media”
Authors: Long Amy , Long Alison , Siby Joseph , Conroy Keavy , Hanley Geoff , Mughal Nasir , Beselaar Zelmarie , Fleming Sarah , Roche Muireann
Published: October 2024

Increased online searches for ‘skin cancer’ and ‘sunbeds’ highlight the need for targeted public health strategies. Leveraging digital data can enhance awareness and prevention efforts.
Left ventricular end-systolic and diastolic elastance as predictors of cardiac events in patients who underwent mitral valve surgery for severe mitral regurgitation
Authors: Noh S A , Park J S , Choi H M , Hwang I C , Yoon Y E , Cho G Y
Published: October 2024

Background/Introduction

In severe mitral regurgitation (MR), the prognostic significance of left ventricular ejection fraction (LVEF) and LV dimensions is well-established. However, the assessment of diastolic function in this patient presents a notable challenge, and its impact on postoperative outcomes remains unclear.

Purpose

This study was designed to explore the potential of LV end-systolic (Ees) and diastolic elastance (Eed) as novel predictors for cardiac events following surgery.

Methods

A retrospective cohort study was performed on 199 patients (53% male, average age 60 years, mean LVEF 60.0%) with severe MR and undergoing surgery. Preoperative Ees and Eed were calculated using established formulas: Ees = (systolic blood pressure x 0.9) / LV end-systolic volume, and Eed = left atrial pressure / stroke volume, with left atrial pressure estimated from mitral Doppler flow parameters as SBP – (4 x peak MR velocity²). The primary outcome was defined as either cardiac death or hospitalization due to heart failure.

Results

Average values for Ees and Eed were 2.61 (IQR: 1.67-3.20) and 0.32 (IQR: 0.05-0.57), respectively. Univariate analysis indicated Ees (HR: 1.24, 95% CI: 0.99-1.57, p = 0.066) and Eed (HR: 5.93, 95% CI: 2.87-12.26) as potential predictors. Adjusting for age, LVEF, and LV dimensions, Eed remained an independent predictor of cardiac events (HR: 5.89, 95% CI: 2.81-12.28). Stratifying Eed at a threshold of 0.31—identified as best sum of sensitivity and specificity—revealed that Eed > 0.31 were associated with a 3.9-fold increase in cardiac events compared to those with Eed ≤ 0.31 (p = 0.008). (Fig.)

Conclusions

The assessment of Eed is a straightforward and readily available parameter in routine clinical practice. Our findings advocate for the inclusion of preoperative Eed evaluation as an independent prognostic indicator for patients undergoing surgery for severe MR.Event free survival by Eed
Is the HNF4A gene variant paradoxically associated with better prognostic in CAD patients?
Authors: Sa D , Mendonca M , Serrao M , Sousa F , Abreu G , Henriques E , Freitas S , Rodrigues M , Borges S , Guerra G , Ornelas I , Drumond A , Sousa A , Palma Dos Reis R
Published: October 2024

Background

The Hepatocyte nuclear factor 4 A (HNF4A) gene was considered to be associated with susceptibility to atherosclerosis and coronary artery disease (CAD). It encodes a protein HNF4α, a genetic transcription factor regulating the genetic expression of thousands of genes playing essential roles in glucose and lipid metabolism. Its abnormal expression is emerging as a critical factor in diabetes, dyslipidemia, and cancer. Loss of function of specific mutations could attenuate its role in CAD pathogenesis and the progression of atherosclerosis.

Aim

To investigate whether a genetic variant (HNF4α rs1884613 C>G) could be associated with a low genetic function and, paradoxically, a better prognostic in CAD patients.

Methods

A cohort of 1,718 patients with coronary angiography (>70% stenosis of at least one main coronary vessel) from the GENEMACOR Study was investigated. Thirty-three genetic variants were genotyped using TaqMan assay methodology and HNF4A rs1884613 C>G genotype models were individually studied regarding the occurrence of Major Adverse Cardiovascular Events (MACEs). We used bivariate analysis to evaluate genotypic and allelic differences. Multivariate Cox regression analysis estimated variables independently associated with MACE, and Kaplan-Meier estimate methodology assessed the survival.

Results

Of the 1,718 CAD patients with the CC wild type, 73.4% had MACE, compared with 66.5% without. CG had 25.2% compared with 30.5% without. Finally, in the GG genotype, only 1.4% had events compared with 3.0% without (p=0.004). Cox regression analysis showed that GG genotype (mutated) is significantly and independently associated with 56% of MACE protection with a hazard ratio (HR) of 0.436; p=0.014. Physical inactivity and type-2 Diabetes remained independently associated with MACE occurrence (Fig.1). Kaplan-Meier cumulative event analysis disclosed that the carriers of the GG genotype were significantly associated with a better event-free time, and CC discloses a worse event-free time (Breslow test, p=0.001) (Fig.2).

Conclusions

The rs1884613 genetic variant of HNF4A is associated with a better CAD prognosis. This variant could probably induce gene downregulation and HNF4A gene function loss. Modifying and modulating hepatic lipase and lipid metabolism positively affected atherosclerosis progression. Future bioactive modulators for HNF4A variants could raise the possibility that diseases involving diabetes, lipid disorders, and cancer might be amenable to pharmacologic intervention.
Functional improvement of non-infarct related coronary artery stenosis by extensive LDL-C reduction with a PCSK9 antibody: the FITTER trial, microvascular function analysis
Authors: Los J , Mensink F B , Jansen T P J , Van Wely M H , Damman P , Van Nunen L X , Ten Cate T J F , Camaro C , Dimitriu-Leen A L , Van Der Heijden D J , Van Royen N , Van Geuns R J M
Published: October 2024

Background

Atherosclerosis and microvascular dysfunction are closely linked. Moreover, impaired microvascular function is strongly associated with increased risk on major adverse cardiac events. In patients presenting with acute coronary syndrome (ACS), microvascular function is reduced. PCSK9-inhibitors have shown to reduce plaque burden and lipid load in epicardial vessels and might exhibit similar results on microvascular vessels, thereby improving microvascular function. The FITTER trial offers the unique opportunity to test this hypothesis.

Methods

The FITTER trial is a multi-center, randomized, double blind, placebo controlled clinical trial for patients presenting with ACS and multi-vessel disease (MVD). After treatment of the culprit lesion, fractional flow reserve (FFR) measurement of non-infarct related artery (non-IRA) lesions was performed. Patients with intermediate, non-critical lesions (FFR: 0.67-0.85) were included in this trial. For exploratory purpose, additional physiological assessment of the non-IRA included coronary flow reserve (CFR) and microvascular resistance index (IMR) measurements. Microvascular function was evaluated using a pressure- and temperature-sensitive guidewire and a bolus thermodilution method. Participants were randomized and treated for 12 weeks with either evolocumab or placebo in addition to high-intensity statin therapy. Staged reevaluation was done at 12 weeks. After repeated physiology testing, PCI was performed if deemed necessary. Pre-defined exploratory analysis includes the absolute and relative difference in change between CFR and IMR from baseline to follow up in the non-IRA. PCSK9 inhibition might result in a relatively larger increase of CFR and larger decrease of IMR.

Results

Between March 2020 and August 2023, a total of 150 patients were included in the trial. In 61 patients (88.5% male, age 65.3 ± 9.1 years, 23.0% STEMI, 70.5% non-STEMI, 6.6% UAP) successful baseline and follow-up measurements of microvascular function were performed. Complete results will be available at the beginning of March 2024. The primary- and secondary endpoints will be submitted for late-breaking clinical trials selection. The results of this abstract will include a per vessel analysis of coronary artery microvascular function.

Conclusion

The FITTER trial will provide new insights on the potential of extensive LDL-C reduction with a PCSK9 antibody on microvascular coronary artery function in patients presenting with ACS and MVD.
Association between reduced risk of gastrointestinal bleeding related to proton pump inhibitor use and subsequent all-cause death in patients with percutaneous coronary intervention
Authors: Ishii M , Nakamura T , Tsujita K , Fujita H , Matoba T , Kohro T , Kabutoya T , Kario K , Kiyosue A , Mizuno Y , Nakayama M , Miyamoto Y , Sato H , Nagai R
Published: October 2024

Background

Gastrointestinal bleeding is the leading cause of post-percutaneous coronary intervention (PCI) bleeding complications which are associated with a high risk for subsequent clinical outcomes. The aim of this study was to estimate association between risk of gastrointestinal bleeding events related to proton pump inhibitor (PPI) use and subsequent clinical outcomes in patients with PCI.

Methods

The Clinical Deep Data Accumulation System (CLIDAS) is a database for inclusive of patient characteristics, medications, laboratory test, physiological test, cardiac catheterization and PCI treatment, all of which were aggregated from electronic medical records in 7 tertiary hospitals in Japan. Data of 6457 patients who underwent PCI between April 2014 and March 2020 and were then followed for 30 days after the index PCI, were analyzed. These patients were divided into two groups based on use of PPI; the PPI group (n=5285; 82%) and the non-PPI group (n=1172; 18%). Clinical outcomes, defined as gastrointestinal bleeding and all-cause death, were assessed using propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) models.

Results

Among the 6457 PCI patients, 90 (1.7%) in the PPI group and 31 (2.6%) in the non-PPI group experienced gastrointestinal bleeding events. Adjusting for baseline demographics, comorbidities, and anti-thrombotic treatments, the multivariable Cox hazard model suggested a trend towards a lower risk of gastrointestinal bleeding with PPI use (HR, 0.70; 95%CI, 0.46-1.05; p=0.087). The PSM analysis confirmed a significant association between PPI use and a lower risk of gastrointestinal bleeding (HR, 0.13; 95%CI, 0.04-0.43; p=0.001), consistent with IPTW model results (HR, 0.60; 95%CI, 0.38-0.95; p=0.031). Subgroup analysis showed that PPI use was associated with a low risk of all-cause death in patients with acute coronary syndrome (ACS) (HR, 0.58; 95%CI, 0.36-0.93; p=0.024). Causal mediation analysis indicated an indirect effect of PPI on reducing all-cause death through the suppression of gastrointestinal bleeding events.

Conclusion

These findings suggested that use of PPI against gastrointestinal bleeding complications might reduce the risk of subsequent all-cause death in ACS patients undergoing PCI.