bluuebunny/crossref_metadata_2025 huggingface dataset:
Sugarcane Yellow Leaf Virus – A Silent Threat?
Authors: Gama Andre B. , Flasco Madison T.
Published: October 2024

Sugarcane yellow leaf virus (SCYLV) is the causal agent of yellow leaf disease, a significant threat to global sugarcane production. SCYLV is disseminated via infected planting material and transmitted by aphids, primarily by
Melanaphis sacchari
(Zehntner). The disease’s impact varies depending on the sugarcane cultivar, with some varieties showing little to no foliar symptoms, yet experiencing severe yield losses. Reliable diagnostic methods, including serological and molecular techniques, are crucial for accurate detection, though these methods vary in sensitivity. Advances in molecular techniques have revealed ten major SCYLV genotypes grouped into three phylogroups, further complicating detection efforts. Improved understanding of SCYLV’s distribution within the plant and its seasonal variability are yet to be understood. Management strategies focus on breeding SCYLV-resistant varieties, but this is challenging due to the virus’s variable impact on yield and the often asymptomatic nature of epidemics. Efforts to develop SCYLV-free propagative material have been implemented, but the virus can still spread via aphid vectors from neighbouring fields. Ongoing research aims to identify resistant cultivars, optimize diagnostic techniques, and better understand the epidemiology of SCYLV to mitigate its impact on sugarcane yield and quality.

Information

© The Authors 2024
Discussion on the upper limit of HIFU sound pressure measurement based on laser interferometry
Authors: Wang Ke , Xing Guangzhen , Wang Min , Yang Ping
Published: October 2024

High intensity focused ultrasound (HIFU) technology is a non-invasive treatment technique that can achieve non-invasive treatment of tumors and other diseases. The accuracy of HIFU sound pressure is crucial for the clinical efficacy and safety of HIFU treatment. The sound pressure measurement technology based on laser interferometry is the recommended method for ICE TC87, which has the advantages of high measurement accuracy and good traceability, and is therefore widely adopted as the new generation of sound pressure standards. However, the upper limit of the laser interferometric HIFU sound pressure measurement currently reported is about 10 MPa, which is far lower than the actual sound pressure of HIFU technology. In response to this issue, the upper limit of HIFU sound pressure measurement was discussed from the perspective of laser interference systems. The mathematical relationship between the HIFU sound pressure and the optical and electrical signals of the laser interference system under the condition of nonlinear sound field is established. The mathematical analysis of HIFU sound pressure requirements for the bandwidth of laser interference systems is discussed. Using experimental and numerical simulation methods, the effect of HIFU sound pressure on the bandwidth of a laser interference system under nonlinear acoustic field conditions was studied.
Photoacoustic differential attenuation spectrum for bone assessment
Authors: Xu Wenyi , Xie Weiya , Yu Dong , Sun Haohan , Gu Ying , Tao Xingliang , Qian Menglu , Cheng Liming , Wang Hao , Cheng Qian
Published: October 2024

Photoacoustic (PA) technology shows great potential in bone microstructure assessment. Due to the solid-liquid two-phase characteristics of cancellous bone, the PA signal received by transducers is aliasing of distributed PA source characteristics and acoustic propagation characteristics of cancellous bone. The contribution of various multi-scale distributed PA sources to the PA signal complexity leads to difficulty in identifying the sound propagation characteristics, making it difficult for quantitative assessment of bone microstructure. To eliminate the spectrum contribution of the PA source to the PA signal, we proposed an eccentric excitation-differential detection system and the acoustic propagation characteristics of cancellous bone can be obtained by calculating the PA differential attenuation spectrum (PA-DAS). The PA-DAS quantization parameter-slope is further extracted to quantify the attenuation of different frequency components. Simulation results show that slope strongly correlates to the porosity of cancellous bone, demonstrating the eccentric excitation-differential detection system combined with the PA-DAS method can realize the quantitative bone assessment.
CNN applied to ultrasonic guided wave spectrum image classification
Authors: Cisternas Williams Flores , Aguilera Ana , Olivares Rodrigo , Munoz Roberto , Minonzio Jean-Gabriel
Published: October 2024

Osteoporosis is a worldwide problem associated with an increasing number of fragility fractures. Currently, the standard for identifying patients at risk of fragility fracture is through Dual X-ray Absorptiometry (DXA). Different altenatives have been proposed, such as magnetic resonance imaging (MRI), three-dimensional X-rays, ultrasound or algorithms providing scores from clinical data. Among ultrasonic techniques, Bi-Directional Axial Transmission (BDAT) has been used to classify patients with or without fragility fractures, initially using ”classical” ultrasound parameters, such as velocities and latter using Support Vector Machine and automatic features, with performances close to the gold standard DXA. The aim of this study was to investigate the use of Convolutional Neural Networks (CNN) applied to patient classification using ultrasonic guided wave spectrum images, using a previous database of post menopausal women with or without fragility fractures. Two networks will be tested, a reference one, ResNet, successfully applied in classification and diagnosis in medical images, and a tailored one, denoted BDAT-Net, which hyperparameters will be optimized through a grid approach. The obtained accuracy, using BDAT-Net and clinical data (age, body mass index, cortisone intake) was found equal to 0.66 [0.64-0.69] comparable with the one obtained with DXA and significantly better than the one obtained with ResNet. These encouraging results open the door to the use of robust ultrasonic devices for fracture risk assessment, in particular in countries where DXA is not widely available.
Photoacoustic/ultrasound dual-modality imaging of Sentinel lymph node with carbon nanoparticles
Authors: Deng Handi , Gu Liujie , Bai Yizhou , Ma Cheng , Luo Bin
Published: October 2024

Sentinel lymph node (SLN) biopsy is a widely used method for identifying axillary lymph node metastasis in breast cancer patients, offering an avoidance of unnecessary axillarydissections and a lower incidence of lymphedema and other complications. However, the nuclide localization has added complexity to the procedure due to its accessibility. Methylene blue and other small molecule dyes have been widely used due to their convenience, but they have been found to have lower specificity and sensitivity. Carbon nanoparticles (CNPs), as a new type of tracer, are safe and show improved specificity. However, the significant optical absorption in human tissues still renders the detection of deep lymph nodes challenging. To overcome these challenges, we developed a high-sensitivity ultrasound probe optimized for photoacoustic imaging. Based on the new probe, we constructed a high-sensitivity photoacoustic/ultrasound dual-modality imaging system. A pilot clinical study has been conducted on two patients, preliminarily verifying the system’s ability to locate SLN when combined with the CNPs.
Finite element analysis of a Helmholtz transducer jointly driven by a trilaminar ring and a piezoelectric circular tube
Authors: Zhu Chenhui , Dai Yuyu , Zhou Yinqiu , Zhang Xiumei , Zhao Jiaheng
Published: October 2024

Crosswell seismic survey can image the crosswell geological anomalies with high resolution in 3D. To effectively conduct crosswell seismic survey, it is necessary to use a seismic source capable of transmitting low-frequency and high-power signals in a compact size. In this paper, a novel Helmholtz transducer is proposed, which utilizes both the bending vibrations of the trilaminar ring and the radial vibrations of the piezoelectric circular tube to simultaneously drive the vibration of the Helmholtz liquid cavity. This design reduces the resonant frequency of the liquid cavity while enhancing the transmitting voltage response at the liquid cavity resonant frequency. The influence of the inner radius of the trilaminar ring, the outer radius of the ceramic ring and the length of the piezoelectric circular tube on the liquid cavity resonant frequency and the transmitting voltage response at the liquid cavity resonant frequency is simulated using the finite element method. The simulation results provide a theoretical foundation for optimizing the design of such transducers.
A novel cryogenic acoustic microscope to evaluate electronic components
Authors: Bond L.J. , Barnard D. , Doran S. , Edayath S. , Feng Y. , Krennrich F. , Poonthottathil N. , Weinstein A.
Published: October 2024

Electronics to operate at cryogenic temperatures is key to many areas of science, including space exploration and in particle physics. Ensuring circuit functional reliability is mission critical. One system that will use tens of thousands of custom designed application specific integrated circuits (ASIC) is the Deep Underground Neutrino Experiment (DUNE), which will have sensor circuits operating in liquid argon (87 K) for decades. Both functional and nondestructive testing are being used to ensure circuit quality and reliability. Part of this work involves design, testing and data analysis using a cryogenic acoustic microscope operating at frequencies up to 50 MHz. Image analysis and correlations are used to compare differences seen before and after cryogenic cycling. Data are reported that were collected at room temperature (300 K) and when cooled using liquid nitrogen (77 K).
Analysis of electromechanical equivalent circuit model for the functionally graded tubular piezoelectric transducer
Authors: Wang Sha , Zhu Yazhou , Lin Shuyu
Published: October 2024

In this paper, a functionally graded tubular piezoelectric transducer (FG-tPET) is proposed. Based on the constitutive equation and wave equation, the electromechanical equivalent circuit model (EECM) of FG-tPET is obtained. When the non-uniformity coefficient tends to zero, the EECM can be simplified as the EECM of the traditional single-tube piezoelectric ceramic transducer. The correctness of the theoretical model is verified in comparison with the experimental results in the literature. Based on the theoretical model, the influence of the geometric size and the non-uniform coefficient of the transducer on the resonance/anti-resonance frequency is analyzed. The results show that the geometric size and the non-uniform coefficient can realize the coordinated adjustment of the resonance/anti-resonance frequency.
Measurement of thickness and ultrasonic velocities based on imaging method using laser-generated ultrasonic waves at thermoelastic regime
Authors: Dung N T , Arai Y
Published: October 2024

This study introduces a simple method for determining thickness and ultrasonic velocities, including skimming longitudinal waves, longitudinal waves, and shear waves, utilizing laser-induced ultrasonic waves at the thermoelastic regime and the time-position imaging technique. Laser scanning was performed on two aluminum samples with thicknesses of 6 mm and 10 mm, generating data on the arrival time of multiple wave modes according to the separated distances of two laser spots. Using the least squares technique, the data obtained from the experiment were employed to fit theoretical curves of various waves, enabling the simultaneous determination of several material parameters. The proposed method exhibits high accuracy in determining thickness, with a maximum relative error of 1% for thicknesses up to 10 mm. Additionally, comparisons with theoretical calculations reveal maximum errors of 1 % for shear wave velocity and 0.8 % for longitudinal wave velocity. The ratio between the velocity of skimming longitudinal wave and bulk longitudinal wave of 0.95 was established, providing a prospective method to calculate longitudinal wave velocity through guided waves along the surface.
Signal recognition based on transfer learning for Φ-OTDR fiber optic distributed disturbance sensor
Authors: Gan Jiaqi , Xiao Yueyu
Published: October 2024

Traditional classification models for optical fiber vibration signals can achieve good recognition results when there are a large number of samples. However, it is difficult to obtain sufficient training samples in real scenes. A method of Φ-OTDR sensor signal recognition based on VGGish transfer learning is proposed in this paper. Firstly, a selection indicator is designed to filter out vibration signals from sparse signals. Then, the VGGish network pretrained for sound classification is used for transfer learning as a feature extractor for optical fiber vibration signals. This method was applied to classify 6 kinds of optical fiber vibration signals. When the number of training samples is reduced to 480 samples, the method can still achieve 84.17% classification accuracy. Compared to the method of training from scratch, this proposed method reduces training time by 73.9%.
Internal Quality Inspection and Characterization of Casting Billets Based on Ultrasonic Microscopy
Authors: Liu Yanbo , Pan Fushuai , Li Hangkai , Yang Denbin , Li Min
Published: October 2024

For evaluating the internal quality of casting billets, the low-power experimental and metallographic methods have the disadvantages of the complex process, the small detection range and the destructive evaluation. In addition, the internal defects of the casting billet are analyzed by the one-dimensional waveform and two-dimensional image for the traditional ultrasonic testing, which can not describe directly the three-dimensional spatial information. Hence, a new method is proposed based on ultrasonic microscopy to detect and characterize the internal defection of the casting billet. In this paper, 42CrMo casting billet is regarded as objective, five sets of samples are fabricated by adjusting temperature gradient field and the number of presses. The ultrasonic sequence images of the present samples are achieved by using ultrasonic microscopy, and the spatial distributions, number, and sizes are obtained for the defects of the casting billet by reconstructing the three-dimensional appearance of microdefects to characterize the internal mass of the casting billet. Finally, the effective and accuracy of the proposed method are validated by using metallographic method.
Influence of sweep duration on debonding detection of honeycomb structures based on acoustic band gap
Authors: Yuan Ye , Liu Bin , Jia Han , Zhang Zhiguo
Published: October 2024

Honeycomb structure is widely used in many fields, and its bond quality needs to be tested during manufacture process and in service. However, the efficiency, sensitivity, and feasibility can hardly be achieved simultaneously for traditional non-destructive testing methods. In the previous work, we have proposed a new debonding detection method using the acoustic band gap of honeycomb structures. Nevertheless, the influence of the detection parameters on the testing result has not been thoroughly investigated. In this paper, the effect of duration variation of the sweep signal used for exciting on the results is studied. Experimental results demonstrate that the transmission frequency response (TFR) of both the intact and the debonding area almost keep unchanged as the sweep duration varies from 1 s to 0.001 s. Theoretical analysis shows that the upper limit of the sweep rate is about 500 MHz/s, i.e., the minimum sweep duration is about 1.2 × 10−5 s to detect a bandgap with a bandwidth of about 6 kHz. Therefore, a shorter sweep duration can be used to further improve the detection efficiency.
Phased Array Ultrasonic Inspection of Composite Fuselage Panel
Authors: Zhiying Li , Feifei Liu , Yusen Yang , Songping Liu
Published: October 2024

The composite fuselage panel is a crucial component in large civil aircraft, necessitating higher detection rates and efficiency. Phased array ultrasonic testing can enhance the efficiency and defect detection rate; however, it is essential to consider the structural characteristics of the fuselage to ensure reliable identification of design defects. Based on the material properties, structural features, and defect detection requirements of composite fuselage panels, a test block reflecting their characteristics was designed and fabricated with various prefabricated defects. Ultrasonic phased array method was employed for a series of testing parameter optimization experiments and defect detectability analysis. The detected flaws were quantitatively analyzed and compared with those obtained using conventional ultrasonic automatic scanning techniques to validate the effectiveness of the developed ultrasonic phased array method. The feasibility of utilizing phased array ultrasonics for nondestructive evaluation of wide-body airliner composite fuselage panels is confirmed.
Study of ultrasonic parameters for quality monitoring of plate heat exchanger
Authors: Dubey P , Declercq N F
Published: October 2024

Heat exchangers are crucial heat transfer devices widely used in energy industries such as power generation, oil production, and engine cooling. The plate heat exchanger is one of the most economical and efficient types of exchangers. It transfers heat using metal plates and has a high heat transfer efficiency because the fluid is exposed to a higher plate surface area. However, due to the presence of dissolved or suspended particles in the heat-exchanging fluids, a layer of deposit (fouling layer) is formed on the heat exchanger plates. It results in reduced efficiency of the device. Thus, a common cleaning method, such as chemical-based or manual methods, is employed. However, it always poses a risk of over-cleaning or removal of the protective oxide layer. Thus, an efficient mechanism to monitor the onset of the fouling layer would greatly help to achieve increased efficiency and cost reduction in the cleaning of the plates. Recent advances show ultrasound as one of the promising non-destructive inspection techniques to monitor the growth of the fouling layer. However, the variation in heat-exchanging fluid temperature affects the investigated acoustical parameter measurement. Thus, this research aims to study the linear and nonlinear ultrasonic parameters incorporating temperature-dependent effects from the fluid to provide an accurate real-time monitoring tool. The nonlinear acoustics analysis is experimentally employed in the research using the Second harmonic generation method (SHGM). The proposed research will help design ultrasound-assisted plate heat exchangers for maximum heat transfer efficiency.
Airframe Icing Properties and Geometry Reconstruction using Ultrasonic Full Waveform Inversion Method
Authors: Leon Kaswango Kanama , Dawei Wu
Published: October 2024

Recently, Non-destructive Ultrasonic Techniques have been utilized to detect aircraft icing. Traditional methods like ultrasound pulse-echo, guided waves, and optics are unsuitable due to ice’s complex properties and shape. Pulse-echo ultrasound, reliant on surface layer travel time, becomes ineffective with thin ice layers and variable ice properties. This research aimed to reconstruct ice properties and geometry on aircraft surfaces using ultrasonic full waveform inversion (FWI). For simulation COMSOL software is used to verify wave propagation through a nonlinear, thinly layered model. Wave propagation is then modelled using the 2D acoustic equation and finite differential methods, generating synthetic data. The FWI algorithm implemented, utilizes this synthetic data to reconstruct material properties and ice shape. Crucially, ultrasound transducers are discreetly positioned beneath the aircraft skin to non-destructively gather ice information without affecting aerodynamics.
Phase-modulated pulsing coherent acoustic tweezers for dynamic adjustable spaced particle patterning
Authors: Li Xin , Pan Hemin , Wang Xinyue , Mei Deqing , Wang Yancheng
Published: October 2024

Acoustic tweezer technique with non-contact micro-object manipulation capability has been widely utilized for particle patterning in the fields of cell arraying, target drug delivery, and functional composite fabrication. However, the manipulation resolution of acoustic tweezer device is decided by the configuration of interdigital transducers (IDTs), which is half the wavelength of surface acoustic waves (SAWs). This limitation severely reduces the manipulation versatility of acoustic tweezer devices. To address this limitation, we propose a novel approach that employs phase-modulated pulsing coherent SAWs. This method can halve the patterning spacing and allows for customization of the spacing based on specific manipulation demands. Our proposed technique increases the flexibility and manipulation resolution of acoustic tweezer device, and thus can be widely applied to reconfigurable assembly and precise manipulation of particles and cells.
Particle manipulation based on curved, slanted-finger interdigital transducer
Authors: Jue Bingjin , Zhang Xiaofeng
Published: October 2024

In this paper, an acoustic particle manipulation device is proposed to realize multi-function particle operation in a droplet. A curved slanted-finger interdigital transducer is designed to excite surface acoustic wave (SAW) in different resonance frequency. Diversity acoustic pressure field can be formed by turning the excitation frequency of the transducer. Moreover, through switching the excitation combination of the interdigital transducers, different acoustic field distributions can be aotained and diversity acoustic stream can be formed in the droplet. A finite element model is setup to study the acoustic field distribution and acoustic stream. Simulation results show that when a single frequency SAW is excited, acoustic streaming can be formed in the fluid and the particles can be rotated in the droplet. By switching the excitation frequency of the interdigital transducer, the direction of acoustic stream can be changed. In addition, the interdigital transducer can simultaneously excite multiple surface acoustic waves of different frequencies, which can manipulate the particles move in different tragectory. The study provides an effectively device to multi-function particle manipulation.
Remote liquid level monitoring based on coda wave interferometry
Authors: Jin Chunyan , Zhang Yuxiang , Duclos Aroune
Published: October 2024

Accurate monitoring of liquid level is important for both liquid stocking and related industrial procedures, it is however difficult under extreme circumstances where the inner space of the container is inaccessible or out of reach. Therefore, this paper proposes a remote liquid level monitoring method based on the use of ultrasonic coda wave interferometry. Coda waves stem from multiply scattering of elastic waves under the interactions with the boundary of propagation medium or scatters during their propagation, they are commonly observed in complex propagation medium. For having propagation trajectories much longer than the coherent waves, coda waves are capable of sampling the propagation medium repeatedly and more comprehensively, which in turn provides coda waves with higher sensitivity to its propagation medium. Letting ultrasonic waves propagate within the liquid container, which is often elastic medium, they are capable of probing the solid-liquid interface globally and repeatedly. As the changing in liquid level alters such solid-liquid interfaces inevitably, the propagation of coda wave is thus affected even without any contact with the liquid level. In this manuscript, experimental study is represented, of which the results show that waveform distortion of coda waves, estimated by remnant decorrelation coefficients, is quantitatively related with the change of liquid level, demonstrates the feasibility of remote liquid level measurement and continuous monitoring of liquid level with ultrasonic techniques.
Circular phase shift migration based photoacoustic computational tomography
Authors: Qin Kang , Jin Junyue , Lou Yucai , Liu Siyu
Published: October 2024

In the recent several decades, photoacoustic technique has proved to be capable of noninvasive biomedical imaging with scalable spatial resolution and high penetration depth. To achieve faithful image reconstruction, various method has been proposed, such as back projection, phase shift migration, model-based method, etc. These methods have simple implementations in homogeneous media, whereas in the cases of heterogeneous media (e.g., layered media), complicated modifications with respect to wave propagation at layer interface are always necessary. Here, we propose a frequency domain algorithm extension of phase shift migration in polar coordinates, which is obtained by making second order approximation to the optoacoustic point spread function in cylindrical coordinates and thereafter step by step wavenumber-frequency domain wave field extrapolation along the axial direction. Theoretical simulation and phantom experimental results demonstrate that the proposed circular phase shift migration method can well solve the layered heterogeneous reconstructive problem without modifying the wave propagation model. The acoustic diffraction limited acoustic resolution (up to 225 μm) and high imaging SNR (at least 16 dB) are obtained.
Broadband acoustic waves in plate-like structures for acoustic material characterisation
Authors: Claes Leander , Johannesmann Sarah , Zeipert Henning , Henning Bernd
Published: October 2024

Guided acoustic waves can be used for a multitude of different testing and material characterisation purposes. The options for evaluation are especially plentiful if a method for broadband excitation, e.g. thermoelastic excitation using focused, pulsed laser radiation, is used, and if the distance between excitation and detection of the acoustic waves can be varied. In this contribution, methods to infer different quantitative material properties from the recorded spatiotemporal measurement data are presented, ranging from isotropic elastic properties to parameters describing absorption for complex absorption models.
A generic cell-based biosensor converts bacterial infection signals into chemoattractants for immune cells
Authors: Sarker Sushobhan , Köster Mario , Desai Omkar , Rahim Muhammad Imran , Herrmann Sabrina , Behme Sara , Stiesch Meike , Hauser Hansjörg , Wirth Dagmar
Published: October 2024

Bacterial infection is a major challenge to human health. Although various potent antibiotics have emerged in recent decades, current challenges arise from the increasing number of multi-drug-resistant species. Infections associated with implants represent a particular challenge because they are usually diagnosed at an advanced stage and are difficult to treat with antibiotics owing to the formation of protective biofilms. In this study, we designed and explored a synthetic biology-inspired cell-based biosensor/actor for the detection and counteraction of bacterial infections. The system is generic, as it senses diverse types of infections and acts by enhancing the endogenous immune system. This strategy is based on genetically engineered sensor/actor cells that can sense type I interferons (IFNs), which are released by immune cells at the early stages of infection. IFN signalling activates a synthetic circuit to induce reporter genes with a sensitivity of only 5 pg ml−1 of IFN and leads to a therapeutic protein output of 100 ng ml−1, resulting in theranostic cells that can visualize and fight infections. Robustness and resilience were achieved by implementing a positive feedback loop. We showed that diverse gram-positive and gram-negative implant-associated pathogenic bacteria activate the cascade in co-culture systems in a dose-dependent manner. Finally, we showed that this system can be used to secrete chemoattractants that facilitate the infiltration of immune cells in response to bacterial triggers. Together, the system is not only universal to bacterial infections, but also hypersensitive, allowing the sensing of infections at initial stages.
Improved visualisation of ACP-engineered osteoblastic spheroids: a comparative study of contrast-enhanced micro-CT and traditional imaging techniques
Authors: Hildebrand Torben , Ma Qianli , Loca Dagnija , Rubenis Kristaps , Locs Janis , Nogueira Liebert Parreiras , Haugen Håvard Jostein
Published: October 2024

This study investigates osteoblastic cell spheroid cultivation methods, exploring flat-bottom, U-bottom, and rotary flask techniques with and without amorphous calcium phosphate (ACP) supplementation to replicate the 3D bone tissue microenvironment. ACP particles derived from eggshell waste exhibit enhanced osteogenic activity in 3D models. However, representative imaging of intricate 3D tissue-engineered constructs poses challenges in conventional imaging techniques due to notable scattering and absorption effects in light microscopy, and hence limited penetration depth. We investigated contrast-enhanced micro-CT as a methodological approach for comprehensive morphological 3D-analysis of the in-vitro model and compared the technique with confocal laser scanning microscopy, scanning electron microscopy and classical histology. Phosphotungstic acid and iodine-based contrast agents were employed for micro-CT imaging in laboratory and synchrotron micro-CT imaging. Results revealed spheroid shape variations and structural integrity influenced by cultivation methods and ACP particles. The study underscores the advantage of 3D spheroid models over traditional 2D cultures in mimicking bone tissue architecture and cellular interactions, emphasising the growing demand for novel imaging techniques to visualise 3D tissue-engineered models. Contrast-enhanced micro-CT emerges as a promising non-invasive imaging method for tissue-engineered constructs containing ACP particles, offering insights into sample morphology, enabling virtual histology before further analysis.
Filtered Lie-Trotter splitting for the “good” Boussinesq equation: Low regularity error estimates
Authors: Ji Lun , Li Hang , Ostermann Alexander , Su Chunmei
Published: October 2024

We investigate a filtered Lie-Trotter splitting scheme for the “good” Boussinesq equation and derive an error estimate for initial data with very low regularity. Through the use of discrete Bourgain spaces, our analysis extends to initial data in

H

s

H^{s}

for

0
>
s
≤
2

0>s\leq 2

, overcoming the constraint of

s
>
1

/

2

s>1/2

imposed by the bilinear estimate in smooth Sobolev spaces. We establish convergence rates of order

τ

s

/

2

\tau ^{s/2}

in

L
2

L^2

for such levels of regularity. Our analytical findings are supported by numerical experiments.
Helping Each Other
Authors: Rembis Michael
Published: October 2024

Throughout the first five decades of the twentieth century, former asylum inmates and their allies became increasingly interested in what came to be known as self-managed aftercare. Extra-institutional care, or what was known at the time as parole, had existed in some states since the mid-nineteenth century. It remained underdeveloped, however. Former inmates who wrote about their experiences expressed their deep concerns with the significant challenges they faced in re-entering the world after being committed to an asylum. They along with other former inmates increasingly worked to support one another and to end the stigma associated with madness and institutionalization. By 1937, the groundwork had been laid for the creation of one of the earliest known peer support groups, Recovery, Inc., which was based in Chicago and led by former asylum inmates. Through their work in Recovery, Inc., former inmates and their allies created material and ideological foundations for future peer support networks.
GexMolGen: cross-modal generation of hit-like molecules via large language model encoding of gene expression signatures
Authors: Cheng Jiabei , Pan Xiaoyong , Fang Yi , Yang Kaiyuan , Xue Yiming , Yan Qingran , Yuan Ye
Published: October 2024

Designing de novo molecules with specific biological activity is an essential task since it holds the potential to bypass the exploration of target genes, which is an initial step in the modern drug discovery paradigm. However, traditional methods mainly screen molecules by comparing the desired molecular effects within the documented experimental results. The data set limits this process, and it is hard to conduct direct cross-modal comparisons. Therefore, we propose a solution based on cross-modal generation called GexMolGen (Gene Expression-based Molecule Generator), which generates hit-like molecules using gene expression signatures alone. These signatures are calculated by inputting control and desired gene expression states. Our model GexMolGen adopts a “first-align-then-generate” strategy, aligning the gene expression signatures and molecules within a mapping space, ensuring a smooth cross-modal transition. The transformed molecular embeddings are then decoded into molecular graphs. In addition, we employ an advanced single-cell large language model for input flexibility and pre-train a scaffold-based molecular model to ensure that all generated molecules are 100% valid. Empirical results show that our model can produce molecules highly similar to known references, whether feeding in- or out-of-domain transcriptome data. Furthermore, it can also serve as a reliable tool for cross-modal screening.
Gene-gene and gene-environment interaction in coronary artery disease risk
Authors: Sousa F , Mendonca M I , Sa D , Abreu G , Henriques E , Rodrigues M , Freitas S , Borges S , Guerra G , Drumond A , Sousa A C , Palma Dos Reis R
Published: October 2024

Coronary Artery Disease (CAD) is a lethal illness that kills millions of individuals each year worldwide. This disorder is multifactorial, resulting in the complex interplay of genetic, epigenetic, and environmental factors. Exploring gene-gene and gene-environment interactions is essential to understanding the aetiology of common complex diseases like CAD.

Aim

We proposed investigating the interaction between two genetic variants robustly associated with CAD by GWAS (MTHFR rs1801133 and APOE rs7412/rs429358) in cardiovascular susceptibility. After that, consider whether there was a new interaction between this genetic association and environment (hypertension, dyslipidemia and smoking).

Methods

A case-control study enrolled 3,157 individuals, 1,721 coronary patients (with at least 70% stenosis of one or more major coronary arteries or its primary branches on the coronary angiography) and 1,436 controls without CAD. Traditional risk factors were investigated, and the two polymorphisms were performed by TaqMan real-time PCR. Bivariate analysis was used to study genotypic proportions between CAD and non-CAD patients with respective odds ratios (OR). Logistic regression analysis displayed the interaction between the two genetic variants each other and with some important environmental risk factors.

Results

In bivariate analysis, the genetic models were studied for both genes, being the dominant model the one which showed significance for CAD. In MTHFR, 57.8% of the patients and 53.4% of the controls presented the CT+TT genotype (OR=1.20; p=0.013). In APOE, 26.5% of the patients and 22.3% of the controls had E2E4;E3E4+E4E4 (OR=1.26; p=0.006). The first multivariate logistic regression showed a synergistic interaction between the two genetic variants (OR=1.50; p=0.001). After adjusting for conventional risk factors, the logistic regression analysis entered the MTHFR rs1801133 and APOE rs7412/rs429358, showing a combined interaction effect between those genes and smoking status with an OR of 3.44 (p<0.0001), with hypertension (OR=1.55; p=0.002) and with dyslipidemia (OR=1.71; p<0.0001).

Conclusion

According to our results, the genetic interaction between APOE and MTHFR synergistically affected the susceptibility to CAD. This interaction, linked to conventional risk factors, consistently increased the risk of CAD in our population, particularly in the group of genetic carriers who did not quit smoking.
Association of the lipoprotein(a) gene (LPA) p.Ile4399Met variant with lipoprotein(a) level and cardiovascular events in patients following coronary artery bypass grafting under 65 years of age
Authors: Golab A , Klajmon A , Plicner D , Undas A , Wypasek E
Published: October 2024

Introduction

Lipoprotein(a) (Lp[a]), a well-known risk factor for atherosclerotic cardiovascular disease, is largely determined by variation in the Lp(a) gene (LPA) locus encoding apolipoprotein(a). The LPA gene Ile4399Met (rs3798220) variant has been previously reported to have a strong association with the Lp(a) level in patients with coronary artery disease (CAD), however, its prevalence in the middle-age patients after coronary artery bypass grafting (CABG) has not been investigated.

Purpose

To assess the frequency of the LPA gene c.5673A>G variant (p.Ile4399Met; rs3798220) in Polish patients with CAD following CABG under 65 years of age and determined its association with laboratory and clinical variables.

Materials and Methods

We studied 215 patients with stable CAD, aged 59.5±4.9 years, who underwent primary and isolated CABG surgery (at age of 57.8±5.4 years), including 195 (90.8%) male. Clinical characteristics and analysis of the LPA c.5673A>G variant were performed.

Results

The genotype distribution was as follows: AA – 192 (89.3%), AG – 19 (8.8%), and GG – 4 (1.9%). The c.5673G allele carriers had higher Lp(a) level (106.5 [IQR 77.9-149.7] vs 10.4 [IQR 4.4-43.0] mg/dL, p<0.001) compared with non-carriers. Among the c.5673G allele carriers, Lp(a) correlated positively with pack-years of smoking (r=0.563, p=0.045) and fibrinogen (r=0.431, p=0.040), but not with low-density lipoprotein cholesterol (r=0.202, 0.368). There were no other genotype-associated differences with regard to demographic and clinical variable between carriers and non-carriers, including myocardial infarction (56.5% vs 47.9%, p=0.511), peripheral artery disease (21.7% vs 15.1%, p=0.377) and cerebrovascular events (13.0% vs 6.7%, p=0.389).

Conclusions

To our knowledge, this is the first report on the prevalence of LPA rs3798220 variant in patients with advanced CAD following CABG surgery under 65 years of age. We showed a relatively high (10.7%) percentage of c.5673G allele carriers who have ten times higher Lp(a) levels compared to the wild type, however, its impact on cardiovascular events requires further studies.
Circulating ACE2 and the association of endothelial progenitor cell in CAD patients
Authors: Lu Y W , Huang P H
Published: October 2024

Background/Introduction

Angiotensin-converting enzyme (ACE) 2 is the homologue of ACE, and the local up-regulation of ACE2 expression associates to antiatherosclerosis. ACE2 hydrolyzes the angiogensin II, which related to impair of endothelial progenitor cell (EPC) function. EPCs maintain the integrity of vascular endothelium in case of damage. Decreased number of EPCs associate thrombosis.

Purpose

To investigate the circulating ACE2 and the link to EPC in CAD patients.

Methods

Data from 650 patients with stable angina pectoris requiring invasive coronary angiography were enrolled. They were divided into two groups according to the median value of ACE2. Two interventional cardiologists diagnosed obstructive CAD by angiography review. Demographic characteristics and clinical outcomes were compared between groups.

Results

In all subjects (median age 67 years, male=66.9%), a higher ACE2 level indicates elder, higher prevalence of hypertension, diabetes mellitus and chronic kidney disease. Significant EPC elevation when CAD numbers increased in higher ACE2 group (SVD vs. DVD vs. MVD = 0.005 vs. 0.006 vs. 0.007, p value=0.044). In multivariate analysis, higher ACE2 is positively correlated to triple vessel disease (TVD vs. no CAD, adjusted odds ratio=1.627, 95% CI 1.026-2.579).

Conclusions

Our data demonstrated higher circulation ACE2 links to EPCs in CAD patients.
Ticagrelor or prasugrel versus clopidogrel in patients with coronary heart disease
Authors: Costa L , Nunes R A B , Scudeler T L , Santana G C , Pereira D C G , Thiago Midlej Brito T M B , Oliveira R P
Published: October 2024

Introduction

Antiplatelet therapy is pivotal in the management of coronary heart disease (CHD), especially after percutaneous coronary intervention (PCI). Clopidogrel has long been the cornerstone of dual antiplatelet therapy. However, newer agents like prasugrel and ticagrelor boast of faster onset of action and greater platelet inhibition, which may translate to improved outcomes.

Purpose

Our hypothesis is that prasugrel or ticagrelor are superior to clopidogrel in reducing cardiovascular mortality in chronic CHD patients.

Methods

We conducted a retrospective cohort study using the TriNetX network database, including patients with chronic CHD on dual antiplatelet therapy. A total of 1,420,165 patients on clopidogrel and 197,783 on prasugrel or ticagrelor were identified. We assessed the primary composite endpoint of cardiovascular mortality over a 5-year follow-up period, using event-free survival as our main outcome measure.

Results

The 5-year follow-up data revealed a significant difference in event-free survival between the groups. Patients on prasugrel or ticagrelor had a markedly higher event-free survival rate of 83.156% compared to 73.209% for those on clopidogrel. The Log Rank test showed a confidence interval of 1.544 to 1.592 with a highly significant p-value of <0.0001.

Discussion

The data suggest a clear benefit of prasugrel or ticagrelor over clopidogrel for event-free survival in CHD patients. This could be attributed to the more potent antiplatelet effects of these drugs, leading to reduced thrombotic events. Given the substantial sample size and robustness of the data, the findings advocate for a paradigm shift in the choice of more potent antiplatelet agents in clinical practice.

Conclusion

Our analysis supports the hypothesis that prasugrel or ticagrelor are associated with significantly lower cardiovascular mortality compared to clopidogrel in patients with chronic coronary heart disease.5-year Kaplan-Meier curves for mortality
Accuracy of machine learning techniques to predict stress echocardiography results using clinical variables
Authors: Ihekwaba U , Price B , Bennasar M , Johnson N , Oke J , Khoo J , Squire I , Kardos A
Published: October 2024

Background

Stress echocardiography (SE) is a diagnostic prognostic imaging modality for suspected coronary artery disease (CAD). Cardiovascular risk factors (CVRF) are used in the assessment of the probability of CAD. The link between the outcome of SE and patients’ variables including CVRF, current medication, and anthropometric variables has not been widely investigated.Objective: The aim of this study is to understand whether a machine learned algorithm can be used to predict significant CAD defined by inducible ischemia on SE in patients with suspected CAD based on anthropometrics, CVRF, and medication as variables.

Methods

A machine learning (ML) framework was generated to automate the prediction of inducible ischemia on stress echocardiography results. A mutual information-based feature selection methods (support vector machine (SVM) and random forest (RF) classifiers) were used to investigate the amount of information that each feature carried to define the positive outcome of SE.Data from 2201 patients were used to train and validate the framework. Patients mean age was 62 (SD 11) years. The data consists of anthropological data and classical CVRF, atrial fibrillation, prior diagnosis of CAD, stroke, obstructive airways disease, chronic inflammatory disease, chronic kidney disease (CKD>3) and prescribed medications at the time of the test. There were 394 positive and 1807 negative SE cases. Five-fold cross-validation was used to validate the performance of the framework.

Results

The feature selection methods showed that prescribed medications such as Weight, Diabetes, Antiplatelet drugs and ACE- inhibitor/ARB, were the features that shared the most information about the outcome of SE (sensitivity and specificity of 81% and 51% and 81% and 61% for SVM and RF, respectively) with the accuracy of 82%.

Conclusion

This study shows that ML can predict the outcome of SE based on only 4 clinical features. Further research correlating the clinical variable and SE result to cardiovascular outcome will improve the model’s clinical utility and facilitate patient selection for early treatment avoiding unnecessary downstream testing.
Outcomes by race and ethnicity in patients undergoing percutaneous coronary intervention of chronic total occlusion
Authors: Petrovic M , Vogel B , Sartori S , Oliva A , Smith K , Krishnan P , Sweeny J , Lakshmi Gujjarllamudi S V , Moreno P , Melacorde P , Dangas G , Kini A , Sharma S K , Mehran R
Published: October 2024

Background

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) carries increased risk for worse outcome. There is limited data on whether race and/or ethnicity affect outcomes.

Materials and methods

We included patients who underwent CTO intervention from 2012 to 2017 at The Mount Sinai Hospital (New York). Data were collected prospectively but examined retrospectively. The patients were stratified by race/ethnicity in Caucasians, African Americans, Asians and Hispanics. The primary end point was major adverse cardiac events (MACE) defined as the composite of death, myocardial infarction (MI), and target vessel revascularization (TVR) at 1 year follow-up. Secondary outcomes included individual components of the MACE (death, MI or TVR), and bleeding.

Results

A total 1,684 patients were included of which (49.8%) were Caucasians, 168 (10%) were African Americans, 396 (23.5%) were Asians and 281 (16.7%) were Hispanics. African Americans had the highest proportion of female patients (39%) and more often had a history of smoking (26.2%) and insulin-dependent diabetes mellitus (46.6%) compared to the other groups. They had the highest prevalence of in-stent restenosis as the target lesion (Table 1). Caucasians were older (65.9±11.1 years) with more calcified lesions and longest lesion length compared to the other groups. Asians had highest prevalence of multi-vessel coronary disease. Caucasians and Asians had higher Syntax score and more stents implanted. Procedural success was similar between the groups (Table 1). Adjusted analyses did not show any differences in clinical outcomes between groups (Table 2).

Conclusion

In spite of many differences between racial/ethnical groups in baseline and procedural characteristics, procedural success of CTO intervention and 1-year MACE rates were similar between groups.Procedural characteristicsAdjusted 1-year outcomes