bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract

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.
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

Abstract

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 &gt; 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

Abstract

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&gt;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 (&gt;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&gt;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

Abstract

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.