bluuebunny/crossref_metadata_2025 huggingface dataset:
An Articulatory Analysis of American English Rhotics in Children With and Without a History of Residual Speech Sound Disorder
Authors: Eads Amanda , Kabakoff Heather , King Hannah , Preston Jonathan L. , McAllister Tara
Published: October 2024

Purpose:

This study investigated articulatory patterns for American English /ɹ/ in children with and without a history of residual speech sound disorder (RSSD). It was hypothesized that children without RSSD would favor bunched tongue shapes, similar to American adults reported in previous literature. Based on clinical cueing practices, it was hypothesized that children with RSSD might produce retroflex tongue shape patterns at a higher relative rate. Finally, it was hypothesized that, among children who use a mixture of bunched and retroflex shapes, phonetic context would impact tongue shape as reported in the adult literature.

Method:

These hypotheses were tested using ultrasound data from a stimulability task eliciting /ɹ/ in syllabic, postvocalic, and onset contexts. Participants were two groups of children/adolescents aged 9–15 years: 36 with RSSD who completed a study of ultrasound biofeedback treatment and 33 with no history of RSSD. Tongue shapes were qualitatively coded as bunched or retroflex using a flowchart from previous research.

Results:

Children with no history of RSSD were found to use bunched-only tongue shape patterns at a rate higher than adults, but those who used a mixture of shapes for /ɹ/ followed the expected phonetic contextual patterning. Children with RSSD were found to use retroflex-only patterns at a substantially higher rate than adults, and those using a mixture of shapes did not exhibit the expected patterning by phonetic context.

Conclusions:

These findings suggest that clients receiving ultrasound biofeedback treatment for /ɹ/ may be most responsive to clinician cueing of retroflex shapes, at least early on. However, retroflex-only cueing may be a limiting and insufficient strategy, particularly in light of our finding of a lack of typical variation across phonetic contexts in children with remediated /ɹ/. Future research should more specifically track cueing strategies to better understand the relationship between clinician cues, tongue shapes, and generalization across a range of contexts.

Supplemental Material:

https://doi.org/10.23641/asha.26801050
An adaptive EKF‐SLAM algorithm for cooperative navigation of multi‐aircrafts
Authors: Chen Wei , Jiang Shan , Cao Jiarong , Sun Ruisheng
Published: October 2024

Aiming at cooperative navigation of multi‐aircrafts, an adaptive EKF‐SLAM algorithm for non‐fixed landmark is proposed. First, the aircraft motion model and angle measurement model are established. Second, the fixed landmark cooperative EKF‐SLAM algorithm is established. Furthermore, a distributed EKF‐SLAM algorithm is designed. Then, the adaptive EKF‐SLAM algorithm with non‐fixed landmark is proposed. Finally, simulation results verify the effectiveness of the proposed algorithm.
Frequency domain attention network for copper chain defect detection in tobacco cutting machine
Authors: Lu Hongbo , Cao Yuanyuan , Huang Jiang , Yao Qingfeng , Cao Jiasheng , Sun Siyuan
Published: October 2024

The detection of defects on the copper chain in the production process of tobacco cutters is crucial for ensuring product quality. Traditional defect detection methods often rely on spatial domain image analysis, which not only has a large computational load but also performs poorly in handling high‐frequency noise and complex backgrounds. To address this issue, this paper proposes a novel neural network model based on frequency domain analysis, called frequency domain attention network. This network first utilizes discrete cosine transform to transform the image from the spatial domain to the frequency domain, effectively reducing computational complexity and improving processing speed. Subsequently, through the innovative frequency domain attention module, the network automatically identifies and enhances key discriminative features in the frequency domain, thereby strengthening the model's ability to identify defects. Finally, the frequency domain attention map, after feature extraction and integration, is inputted into the coupling detection head to achieve high‐precision defect detection. The experimental results show that our method outperforms the SOTA method with an increase of 0.03 in AP and 21 in FPS.
Radar waveform generative design method
Authors: Hu Yuhao , Hu Weidong , Du Xiaoyong , Lei Gang
Published: October 2024

To address the issue of radar detection performance degradation caused by interference in complex electromagnetic environments, this paper proposes a generative waveform design method and demonstrates its advantages. This method fully exploits waveform degrees of freedom to achieve a larger design space, generating a multitude of agile waveform parameters within the constraint envelope through algorithmic processes. This approach enables the radar to maintain detection performance in complex electromagnetic environments. Compared with the traditional waveform design method, the simulation experiment verifies the effectiveness of the generative waveform design method.
Improving protection reliability of series‐compensated transmission lines by a fault detection method through an ML‐based model
Authors: Ebrahimi Hossein , Golshannavaz Sajjad , Yazdaninejadi Amin , Pouresmaeil Edris
Published: October 2024

This article addresses the distance protection challenges associated with the series‐compensated transmission lines and the impact of fault resistance by employing a machine‐learning model. In the proposed model, stacked layers of bidirectional long short‐term memory (Bi‐LSTM) cells are fed by voltage and current signals to distinguish between different fault scenarios. This method takes advantage of only local bus measurements to prevent information leakage in communication channels. Moreover, to make the proposed method harmonics‐robust and improve the correlation interpretation between the features for the Bi‐LSTM model, the 3‐phase raw measurement signals are passed through a discrete Fourier transform (DFT) which extracts their fundamental frequency component magnitudes and angles. Then, an extensive amount of fault scenarios including different compensation levels, fault resistances, and fault locations in normal and power‐swing operational conditions are simulated to train the model. Finally, to validate the performance of the proposed protection method in the series‐compensated transmission lines, distinctive studies are also carried out based on electromagnetic transient simulations. The obtained results confirm the remarkable performance of the proposed method in discriminating fault types, faulty phases, internal or external faults, and normal or power‐swing conditions of the power system.
Multi‐domain pseudo‐reference quality evaluation for infrared and visible image fusion
Authors: Meng Xiangchao , Chen Chaoqi , Liu Qiang , Shao Feng
Published: October 2024

Infrared and visible image fusion involves merging the advantages of infrared and visible images to generate a composite image that encompasses thermal radiation as well as intricate texture details. Infrared and visible image fusion has garnered increasing attention, with numerous fusion methods proposed. However, how to fairly perceive the performance of fused image remains a contentious topic. This paper is dedicated to solving this problem from two perspectives (e.g., subjective and objective aspects). Firstly, an infrared and visible fusion image quality assessment dataset was constructed, including 60 pairs of infrared and visible images captured in various scenes, along with 540 fusion images with different types and degrees of distortions. Additionally, a subjective evaluation dataset of 16,200 subjective scores by 30 participants was further provided for the fused image. Secondly, to overcome the challenging assessment for infrared and visible fusion images without a real reference image, an interesting multi‐domain pseudo‐reference image quality assessment model (MPIQAM) is proposed, by comprehensively considering the thermal radiation information distortion, texture information distortion, and overall naturalness of the fused image. The proposed MPIQAM was compared with 18 mainstream objective metrics, and the experimental findings showcased a commendable level of competitiveness.
Different manifestations of a loop-like transient brightening in solar atmospheres
Authors: Cai Qiangwei , Li Hao , Wang Jincheng , Feng Hengqiang
Published: October 2024

Context. Small-scale transient brightenings that are the consequence of magnetic reconnection play pivotal roles in the heating process of solar atmospheres. These phenomena contain key information about the dynamic evolution of the solar magnetic field. The fine-scale structures triggered by instabilities in these brightenings are intimately connected with the release of magnetic energy.

Aims. To better understand the conversion and release of magnetic energy in small-scale heating events, we investigated the thermal-dynamical behaviors of a loop-like transient brightening (LTB) with plasma blobs.

Methods. We used the spectroscopic and slit-jaw imaging observations taken from the Interface Region Imaging Spectrograph and the extreme-ultraviolet images taken from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory to analyze the plasma properties of an LTB that occurred on February 28, 2014. The space-time maps were created to present the spatial evolution of the LTB, and the light curves were calculated to illustrate the heating process. Additionally, we employed the differential emission measure (DEM) method to compute the temperature and emission measure of the LTB. In order to investigate the plasma motion along the line-of-sight direction, a double-Gaussian function was used to fit the Si IV spectral profiles.

Results. The spectrum and DEM analysis indicate that the LTB was constituted by multithermal plasma with temperatures reaching up to 5.4 × 106 K. The space-time maps of the emission and the Gaussian-fitting results of the Si IV line demonstrate that the LTB not only exhibited bidirectional flows, but was also twisted. Several plasma blobs were identified in the spine of the LTB, suggesting the potential presence of a tearing-mode instability. The low-temperature bands peaked approximately one minute prior to the high-temperature bands, suggesting the occurrence of a heating process driven by magnetic reconnection. The appearance of plasma blobs closely coincided with the sudden increase in the velocity and the quick rise of light curves, providing evidence that plasma blobs facilitate the release of magnetic energy during solar activity.

Conclusions. Based on these findings, we speculate that the LTB was a complex structure that occurred in the upper chromosphere-transition region. These results clearly demonstrate that plasma blobs are important for the conversion and release processes of magnetic energy.
The effect of dilution on the energy dissipation in water interstellar ice analogues
Authors: Schrauwen J. G. M. , Cuppen H. M. , Ioppolo S. , Redlich B.
Published: October 2024

Context. Interstellar ices and their energetic processing play an important role in advancing the chemical complexity in space. Interstellar ices covering dust grains are intrinsically mixed, and it is assumed that physicochemical changes induced by energetic processing – triggered by photons, electrons, and ions – strongly depend on the content of the ice. Yet, the modelling of these complex mixed systems in experiments and theory is complicated.

Aims. In this paper, we investigate the effect of infrared irradiation on a series of different molecules mixed with porous amorphous solid water (pASW) to study the release of vibrational energy in the hydrogen-bonding network of water as a function of mixing ratio and ice content. Particularly, we select mixtures of 20:1 H2O:X and 5:1 H2O:X with X=CO2, NH3, or CH4.

Methods. Infrared radiation was supplied by the intense and tunable free electron laser (FEL) 2 at the HFML-FELIX facility. We monitored the structural changes in the interstellar ice analogue after resonant infrared excitation using Fourier-transform reflection absorption infrared (FT-RAIR) spectroscopy.

Results. We observed that on-resonance irradiation at the OH-stretching vibration of pASW results in quantitatively identical changes compared to pure pASW for all investigated mixtures. The structural changes we observed closely resemble the previously reported local reordering. The 5:1 mixtures show weaker changes compared to pure pASW, with a decrease in strength from NH3 to CO2.

Conclusions. Since the hydrogen-bonding network of pASW restructures similarly upon FEL irradiation, regardless of the mixing component, treating ice layers in models that simulate energy dissipation in the hydrogen-bonding network as pure H2O ice layers can be a justified approximation. Hence, complex systems might not always be necessary to describe the infrared energetic processing of ices.
Comparison of Dust Storm Events between East Asia and North America
Authors: Huang Jianping , Zhou Xiaoyou , Li Yan
Published: October 2024

In this study, the decadal variations of global dust storm events (DSEs) are studied based on two typical cases that occurred in East Asia in 2023 and in North America in 1934, respectively. We found that the periods with weak winter monsoon, varied jet stream, weakened Siberian High (SH) and strengthening atmospheric blocking corresponded to the high incidence of DSEs in East Asia. In recent years, activity of the East Asian DSEs is active again because of the mutual effect of these four systems. Due to the ecological engineering projects in China, the frequency of the DSEs is less than that in Mongolia, whereas in Mongolia, the land degradation causes the frequency of DSEs to increase significantly. In the Great Plains of the United States, high incidence of the DSEs mainly corresponded to periods with strong atmospheric blocking in North America. Since the 1860s, the Great Plains had been affected by destruction of vegetation and drought, with bare soil swept into the air by the strong winds, resulting in “Dust Bowl” in the 1930s. Under the warning of long-term strong DSEs, the U.S. government issued a series of policies to respond to the impact of DSEs, which improved the ecosystem of the Great Plains. As a result of the improved ecosystem and weaker blocking activities in the Great Plains in the 1950s, activity of the DSEs was significantly weaker than that in the 1930s.
An updated review of satellite constraints on airborne dust: Current status and future prospects
Authors: Kahn Ralph A.
Published: October 2024

This is a review paper rather than the report on a single line of research, updated from the 2019 Central Asia Dust Conference (CADUC) assessment. Satellites offer a broad range of constraints on dust particle amount, daily and longer-scale 3-d spatial distribution, particle properties, source locations, and transport pathways. Recent advances in dust particle optical modelling have improved the aerosol microphysical property constraints that can be derived from multi-angle remote-sensing data. Dust impacts on health are also being examined recently. Yet, the data contain spatial and temporal gaps, lack detail in some important respects, and interpretation of the remote-sensing retrieval results requires careful consideration of the information content, which can vary greatly with observing conditions. These data are applied most frequently to dust from North African sources and their journey across the Atlantic, but satellite examination of Asian sources and Pacific transports is now also receiving research attention.
Observation of microclimate diurnal change and successful rate of robusta coffee (Coffea canephora) flower-to-fruit formation
Authors: Amalia Sugiarto Nourma , Bregas Budianto , Astri Muliasari Ade , Fatchur Rochmah Hidayati , Undang  , Gloria Meliala Merry , Edi Wiraguna , Lili Dahliani , Aidil Azhar
Published: October 2024

Observation of diurnal change of microclimate conditions in a robusta coffee plantation in Malang, East Java, Indonesia, was conducted from September to November 2023. The observation was done in two different blocks, Block 1 and Block 2 with 35 years and 89 years plants, respectively. The diurnal microclimate data observed were ambient air temperature, air humidity, light intensity, and solar radiation. The data on the successful rate of flower-to-fruit formation was also analyzed. The vegetation in Block 1 has higher diurnal light intensity and solar radiation than in Block 2. The coffee plants grown in Blocks 1 and 2 have a 56% and 50% success rate of flower-tofruit formation, respectively
Experimental study of the wave characteristics in annular gas-liquid flow along the wide side of a rectangular microchannel
Authors: Bartkus German , Kuznetsov Vladimir
Published: October 2024

The characteristics of gas-liquid annular flow in a microchannel with a rectangular cross-section were experimentally studied for the flow of a mixture of viscous silicone oil PMS 200 - nitrogen. To form the required annular flow regime, a side T-mixer was used at the microchannel inlet. High-speed visualization allowed to register flow areas of menisci and waves at the gas-liquid interface, located on short and wide microchannel sides for the given range of superficial gas and liquid velocities Jgas=24.3-93.8 m/s, Jliq=0.01 m/s. The processing of the flow images was performed using the Python program and areas, which are covered by various size waves on the microchannel wide side between the menisci, were identified and summarized. The dependence of the dimensionless wave area on Regas was obtained and compared with the dynamics of liquid layer thickness for the flow of the PMS200-nitrogen mixture, which was obtained previously.
Correction of the sample temperature in the thermal analysis chamber for studying the kinetics of carbon oxidation
Authors: Kozlova Mariia , Donskoy Igor
Published: October 2024

This paper proposes a method for correcting the sample temperature under experimental conditions in the STA449F1 thermal analysis chamber. Carbon samples are oxidized in air-argon mixture, calorimetric signal is recorded and then processed to study the nutual interactions of heat transfer and chemical reaction. The technique is based on selecting the coefficients of the kinetic model and assessing its correctness using the simplest statistical metric.
LES study of the precessing vortex core mitigation by radial injection in a Francis turbine air model
Authors: Lutchenko I. I. , Palkin E. V. , Mullyadzhanov R. I.
Published: October 2024

This work is devoted to a numerical study of the precessing vortex core (PVC) mitigation in a Francis turbine air model. The approach utilized to suppress the PVC, injection of radial jets, was based on influencing flow zones that are most susceptible to control. The analysis of the time-averaged velocity fields revealed extending of a recirculation zone. The time-averaged pressure pulsations in the flow decreased significantly, that indicates a mitigation of the PVC dynamics. Spectra of the azimuthally decomposed pressure pulsations signal demonstrated a suppression of the m = 1 mode by 25% and m = 2 by 40%, however, it does not coincide with the control efficiency in experimental work of I. Litvinov et al. In further investigations it is planned to vary the spatial orientation of the injection jets in order to achieve more effective PVC suppression.
Heat transfer and irrigating liquid hydrodynamics on one-row vertical bundle of inclined tubes in falling film heat exchanger
Authors: Pavlenko A. N. , Kataev A.I. , Mironova I.B.
Published: October 2024

Spiral-wound heat exchangers widely used currently in various industries provide efficient heat transfer between media through spiral tube winds at evaporation and boiling of falling liquid film. The investigated bundle in the form of one-row vertical bundle of inclined tubes (5 degrees to the horizon) simulates a part of a spiral-wound heat exchanger. Heat transfer and hydrodynamics processes are studied at falling film irrigation by liquid R21 refrigerant at 3 bar of absolute pressure with water as heat carrier. The bundle is placed inside of rectangular heat exchanger with optical windows. Heat transfer measurements are performed for tubes at different positions on the bundle height. Irrigation densities corresponded to falling film Reynolds numbers 300 – 1100, heat flux values within the range of 5000 – 10000 W/m2.
Experimental study of a butanol film motion with a co-current gas flow inside a supersonic nozzle
Authors: Prikhodko Victor , Yarygin Igor , Yarygin Vyacheslav
Published: October 2024

The results of experimental study of the local characteristics of a butanol near-wall film interacting with a co-current air flow in a supersonic nozzle with a geometric Mach number M = 3.75 are presented. The thickness and velocity of the butanol film front as well as waves on its surface in different cross-sections of the nozzle were measured. The role of the boiling process on the film flow inside the nozzle is studied and its effect on the measured film thickness is shown.
Features of the precessing vortex control in the Francis turbine model via jet injection
Authors: Suslov Daniil , Srkipkin Sergey , Shtork Sergey
Published: October 2024

The study elucidates the mechanisms involved in actively controlling vortex phenomena within hydraulic turbines, particularly prevalent during partial load operations, leading to severe pressure fluctuations within the draft tube. Employing laser Doppler anemometry alongside acoustic sensors, the research delves into the flow structure and pulsation characteristics within the conical section of a Francis hydraulic turbine model under the influence of supplementary control jets injected through the runner streamline body. It was observed that orientation of the control jet has a discernible effect on reduction in pressure pulsations emanating from the precessing vortex core (PVC). An optimal injection strategy for diminishing pressure fluctuations while maintaining high turbine efficiency is identified. The findings align with earlier theoretical predictions derived from linear stability analysis of flow perturbations.
Linear stability of the viscous liquid flow in a channel with corrugated walls
Authors: Trifonov Yuri
Published: October 2024

Using the complete Navier-Stokes equations, we investigate the linear stability of a viscous flow in a channel with various corrugated walls. We consider both the longitudinal corrugations when the main flow has two velocity components and the transversely corrugated wall when the basic flow has one velocity component. In frame of one approach and in a wide range of variations in the corrugation parameters and shapes, we analyze the neutral curves for the linear stability problem. We calculate the critical Reynolds number above which the main flow is unstable and there are disturbances growing in time. Perturbations of the velocity and pressure fields are, in general, three-dimensional with two wave numbers. We solve numerically the generalized eigenvalue problem. In the case of the transversely corrugated wall, we obtain two regions of parameters where the dependencies of the critical Reynolds number on the corrugation parameters are qualitatively different. The limits of these regions depend only on the ratio of the amplitude and period of corrugations. In the case of the longitudinal-corrugations, we find the corrugation parameters where the basic flow is unstable with respect to the periodic disturbances with the same wavelength as the corrugations wavelength and undergoes “the unavoidable transition” to a flow with more complicated behaviour in time.
KI-gestützte Entscheidungsfindung in der Geburtshilfe – eine
Machbarkeitsstudie über die medizinische Genauigkeit und Zuverlässigkeit von
ChatGPT
Authors: Bader Simon , Schneider Michael O. , Psilopatis Iason , Anetsberger Daniel , Emons Julius , Kehl Sven
Published: October 2024

Ziel dieser Arbeit ist die Untersuchung der Anwendbarkeit von künstlicher
Intelligenz in der Interpretation und Anwendung medizinischer Leitlinien zur
Unterstützung klinischer Entscheidungsfindungen in der Geburtshilfe. ChatGPT
wurden Leitlinien zu spezifischen geburtshilflichen Fragestellungen zur
Verfügung gestellt. Am Beispiel von mehreren klinischen Szenarien wurde die KI
daraufhin auf seine Fähigkeit geprüft, korrekte Diagnosen zu stellen und
angemessene klinische Entscheidungen zu treffen. Die Ergebnisse variierten,
wobei ChatGPT in einigen der fiktiven Szenarien überwiegend korrekte Antworten
lieferte, in anderen jedoch unzureichend abschnitt. Trotz der Fähigkeit von
ChatGPT, komplexe medizinische Informationen zu erfassen, zeigte die
Untersuchung Einschränkungen in der Präzision und Zuverlässigkeit der
Interpretationen und Empfehlungen. Diese Diskrepanzen weisen auf die
Notwendigkeit einer sorgfältigen Überprüfung durch Fachpersonal hin und betonen
die Bedeutung klarer, eindeutiger Leitlinien-Empfehlungen. Es bedarf zudem einer
kontinuierlichen Entwicklung auf der technischen Seite um künstliche Intelligenz
im klinischen Alltag als Unterstützung nutzen zu können. Insgesamt ist die
Nutzung von KI in der Medizin vielversprechend, jedoch aktuell aufgrund
potenzieller Fehleranfälligkeit und Interpretationsschwächen vornehmlich in
kontrollierten, wissenschaftlichen Settings angebracht, um die Sicherheit und
Genauigkeit der Patientenversorgung nicht zu gefährden.
Transition-Metal-Catalyzed C(sp3)–C(sp3) Cross-Coupling to Construct All-Carbon Quaternary Carbon Centers
Authors: Zhu Shou-Fei , Zhang Qiao
Published: October 2024

Transition-metal-catalyzed C(sp³)–C(sp³) cross-coupling reactions represent a powerful strategy for constructing all-carbon quaternary centers. However, these reactions remain challenging due to significant steric hindrance effects and the propensity for side reactions such as elimination and isomerization. This review provides a comprehensive summary of the progress made over the past few decades in the construction of all-carbon quaternary centers, with a focus on coupling reactions involving tertiary C(sp³) and primary/secondary C(sp³) centers [as the cross-coupling of two tertiary C(sp³) centers remains unsuccessful]. The discussion is organized around reaction conditions, substrate scope, and reaction mechanisms, and a brief overview of transformations based on these coupling reactions is also presented.

1 Introduction

2 3° C(sp3)–1° C(sp3) Cross-Coupling

2.1 Cobalt Catalysis

2.2 Copper Catalysis

2.3 Nickel Catalysis

2.4 Iron Catalysis

2.5 Other Catalysis

3 3° C(sp3)–2° C(sp3) Cross-Coupling

3.1 Copper Catalysis

3.2 Iron Catalysis

4 Conclusion
Improving Patient Wait Times on the First Day of Radiotherapy Treatment
Authors: Krishnatry Rahul , Mummudi Naveen , Laskar Sarbani Ghosh , Deodhar Jayita , Sutar Vivek Vasant , Sutar Avdhoot Balaso , DeNatale Michelle Aileen , Nadar Ruby Daniel , James Shibu , Kinhikar Rajesh Ashok , Agarwal Jai Prakash
Published: October 2024

Long wait times on starting day of radiotherapy (day 1) can cause dissatisfaction among both patients and healthcare providers. Reducing these wait times will decrease stress and decongest hospital facilities especially in current coronavirus disease 2019 times. A multidisciplinary core team was formed during the Stanford-India Collaborative Quality Improvement training to reduce the median wait times on day 1 of treatment from 6 to 4.5 hours (a 25% reduction). Several factors were identified on the fishbone diagram, and key causes were identified using a Pareto chart and action prioritization matrix. The Plan-Do-Study-Act Cycle strategy was undertaken for the identified interventions. The outcome measure was time from arrival at the hospital to entry into a treatment room. Data were obtained from time charts at various stations and electronic records. The secondary measures were visual analog scale (VAS) scores, 80th percentile wait times, and the day-2 delay percentage. The balancing measure was “new errors” due to interventions. The interventions included the completion of all administrative tasks not needing patients' presence on the day before day 1. Baseline data from 198 patients and postintervention data from 160 patients were compared and analyzed. The median wait time at baseline, which was 6 hours, was reduced to 4.2 hours. The VAS score showed 70.4, 67.7, and 71.9% satisfaction for the resident physician, therapists, and patients, respectively. The 80th percentile wait times reduced from 8 to 5.7 hours; and the day 2 starting rate decreased from 22.5 to 2.04%, with no new errors reported. Radiotherapy day 1 wait times can be safely decreased, leading to improved satisfaction among patients and healthcare providers, by utilizing classic quality improvement methods and tools.
The Stomach-Bladder Proximity Sign: What Does it Say?
Authors: Viveka S. M. , Nivedhitha T. , Vaishnavi N. , Ponmozhi G. , Manikandan K.
Published: October 2024

Fetal gastrointestinal tract (GIT) anomalies account for 7 to 8% of congenital malformations. There are no well defined protocols for examining fetal GIT, which is a dynamic system that plays a vital role in amniotic fluid homeostasis. We present four cases that highlight the importance of the relative positions of the stomach, small bowel, and bladder in the coronal plane of the fetal abdomen in the diagnosis/exclusion of certain anomalies.
An instrumentation guide to measuring thermal conductivity using frequency domain thermoreflectance (FDTR)
Authors: Kirsch Dylan J. , Martin Joshua , Warzoha Ronald , McLean Mark , Windover Donald , Takeuchi Ichiro
Published: October 2024

Frequency Domain Thermoreflectance (FDTR) is a versatile technique used to measure the thermal properties of thin films, multilayer stacks, and interfaces that govern the performance and thermal management in semiconductor microelectronics. Reliable thermal property measurements at these length scales (≈10 nm to ≈10 μm), where the physics of thermal transport and phonon scattering at interfaces both grow in complexity, are increasingly relevant as electronic components continue to shrink. While FDTR is a promising technique, FDTR instruments are generally home-built; they can be difficult to construct, align, and maintain, especially for the novice. Our goal here is to provide a practical resource beyond theory that increases the accessibility, replicability, and widespread adoption of FDTR instrumentation. We provide a detailed account of unpublished insights and institutional knowledge that are critical for obtaining accurate and repeatable measurements of thermal properties using FDTR. We discuss component selection and placement, alignment procedures, data collection parameters, common challenges, and our efforts to increase measurement automation. In FDTR, the unknown thermal properties are fit by minimizing the error between the phase lag at each frequency and the multilayer diffusive thermal model solution. For data fitting and uncertainty analysis, we compare common numerical integration methods, and we compare multiple approaches for fitting and uncertainty analysis, including Monte Carlo simulation, to demonstrate their reliability and relative speed. The instrument is validated with substrates of known thermal properties over a wide range of isotropic thermal conductivities, including Borofloat silica, quartz, sapphire, and silicon.
Development of UV light-emitting diodes based AlGaN/GaN heterojunction utilizing thermal oxidation annealing
Authors: Li Qiuen , Kang Xuanwu , Wu Hao , Zheng Yingkui , Liu Xinyu , Huang Chengjun
Published: October 2024

Ultraviolet (UV) irradiation has a significant impact on enhancing the performance of sensors. Currently, there is still an urgent need for devices that are simple and easy to fabricate. In this work, a cost-effective and convenient method was employed to fabricate a UV light emitting diode. A four-inch silicon based AlGaN/GaN heterojunction substrate was used. The Ni/Au (20/20 nm) layer was deposited on the AlGaN barrier layer, followed by thermal oxidation to prepare the UV diode. The diode annealed in oxygen can emit UV light at a wavelength of 365 nm and is visible, and no light is emitted from the device in nitrogen annealing. The I–V and C–V characteristics of the device are tested to explore the mechanism. Transmission electron microscopy and technology computer aided design simulation methods were used to analyze the device luminescence mechanism.
Regulation of epithelial cell jamming transition by cytoskeleton and cell–cell interactions
Authors: Latham Zoe D. , Bermudez Alexandra , Hu Jimmy K. , Lin Neil Y. C.
Published: October 2024

Multicellular systems, such as epithelial cell collectives, undergo transitions similar to those in inert physical systems like sand piles and foams. To remodel or maintain tissue organization during development or disease, these collectives transition between fluid-like and solid-like states, undergoing jamming or unjamming transitions. While these transitions share principles with physical systems, understanding their regulation and implications in cell biology is challenging. Although cell jamming and unjamming follow physics principles described by the jamming diagram, they are fundamentally biological processes. In this review, we explore how cellular processes and interactions regulate jamming and unjamming transitions. We begin with an overview of how these transitions control tissue remodeling in epithelial model systems and describe recent findings of the physical principles governing tissue solidification and fluidization. We then explore the mechanistic pathways that modulate the jamming phase diagram axes, focusing on the regulation of cell fluctuations and geometric compatibility. Drawing upon seminal works in cell biology, we discuss the roles of cytoskeleton and cell–cell adhesion in controlling cell motility and geometry. This comprehensive view illustrates the molecular control of cell jamming and unjamming, crucial for tissue remodeling in various biological contexts.
Experimental identification of longitudinal and vertical lift aerodynamic admittance functions of thin sections
Authors: Yan Lei , Gao Min , He Xuhui , Lin Ze , Shi Mingjie
Published: October 2024

Previous studies of two-dimensional (2D) aerodynamic admittance function (AAF) identification methods have basically ignored the effects of different turbulence components, which may lead to unpredictable errors for practical engineering applications. This paper presents pressure measurement experiments on thin sections with a geometric ratio of 1:50 in various turbulent fields. Based on the three-dimensional (3D) two-wavenumber theoretical analytical framework, the two-wavenumber coherence function is obtained by fitting the measured spanwise root-coherence function at the effective spacing with an empirical model. A new method is proposed, assuming that the ratio relationship between the lift AAFs due to longitudinal and vertical turbulence components of the measured model section satisfies its corresponding theoretical solution ratio relationship. The 2D lift AAFs of the airfoil section induced by different turbulence components are identified following the proposed identification framework. Consistent with the previous research, force correlation is significantly larger than turbulence correlation, and the traditional 3D one-wavenumber AAFs obtained are different in different turbulent fields. The separated 2D lift AAFs demonstrate that the contributions of u- and w- turbulence to the buffeting lift force are significantly different, and are more precise, according to the ratio between the Horlock function and Sears function. Then, the method is successfully extended to estimate the AAFs with respect to the u- and w-turbulence components of a streamlined box girder section, further validating the applicability of the identification method to the streamlined box girder. Furthermore, comparing the separated 2D lift AAFs under different turbulence fields reveals their independence from turbulence characteristics.
Analyzing hydroxyl radical accessibility related to hydrogen abstraction in a DNA sugar moiety using molecular dynamics simulations
Authors: Kawanami Ryuta , Fujiwara Susumu , Yonetani Yoshiteru , Aso Tsukasa
Published: October 2024

Exposure of water to ionizing radiation induces OH radical formation. Within cellular environments, the presence of OH radicals can stimulate the abstraction of hydrogen atoms from the sugar backbone of DNA. Subsequent damage to DNA structures leads to various diseases. Multiple studies have elucidated this phenomenon, especially computational studies examining the differences in the degree of abstraction between the sugar hydrogens (H1′, H2′, H2″, H3′, H4′, H5′, and H5″). However, the details of this phenomenon have not yet been clarified. It is rare for OH radicals to approach DNA within the simulation time, making it difficult to adequately sample the configurations in which OH radicals immediately precede the abstraction of the hydrogen atoms. To address this problem, we performed molecular dynamics simulation to calculate the relative accessibility by putting a potential on nucleotides and OH radicals. As a result, we found that the accessibility of OH radicals to each hydrogen atom differs from that of water molecules as solvents. A more detailed accessibility analysis revealed that the angle of the OH radicals approaching the hydrogen atoms of ribose and the energy barrier for abstracting the hydrogen atoms can be considered to improve the correspondence with the experimental data. Moreover, we found that the behavior of water molecules and OH radicals toward accessibility to DNA differs significantly and showed that the factors are related to the physicochemical properties of water molecules and OH radicals, as well as the structure of DNA.
Strain-controlled switching of magnetic skyrmioniums in ultrathin nanodisks
Authors: Wang Hongchang , Zhang Zhengming , Gong Jianhu , Wang Dunhui , Wang Baomin
Published: October 2024

Magnetic skyrmions and skyrmioniums have garnered significant attention due to their distinctive topologically nontrivial spin structures. Gaining a deep understanding of the magnetization dynamics of these structures and their interconversion processes is essential for fully leveraging their potential in magnetic storage technology. Here, the dynamics of strain-controlled generation and annihilation of skyrmions and skyrmioniums are investigated using phase field simulation methods. It is discovered that tensile strain can induce the transformation of a single domain into skyrmions and skyrmioniums, which can still exist stably after the strain is released. Notably, skyrmioniums demonstrate robust stability within a specific strain window of −0.2% to 0.5%. Beyond this, escalating the compressive strain magnitude induces a phase transition from skyrmioniums to skyrmions, culminating in a direct collapse to a single-domain state at a critical compressive strain of −0.8%. This study reveals that strain can effectively control a variety of topological magnetic domain structures and achieve their interconversion, providing guidance for the design of low-power, nonvolatile, multi-state spin storage devices.
Single-crystal elastic moduli, anisotropy, and the B1–B2 phase transition of NaCl at high pressures
Authors: Xu Feng , Belliard Laurent , Li Chenhui , Djemia Philippe , Becerra Loïc , Huang Haijun , Perrin Bernard , Zerr Andreas
Published: October 2024

Pressure dependences of the highest and lowest possible longitudinal sound velocities in single crystals of the B1 and B2 phases of NaCl were extracted from examination of their polycrystalline samples using the technique of time-domain Brillouin scattering. Based on the data collected up to 41 GPa, we largely extended the pressure range where single-crystal elastic moduli, Cij(P), and elastic anisotropy of the two cubic phases are measured, especially the experimental data for the B2 phase formed upon the reconstructive phase transition. The B1 phase of NaCl exhibits strong and growing anisotropy with increasing pressure, while that of the B2 phase is much weaker. Comparing with the previous experimental Cij(P) of other compounds exhibiting or expected to exhibit the B1–B2 phase transition, such as CaO, MgO, and (Mg1−x, Fex)O, we concluded that the transition is initiated by the shear instability due to violation of the Born stability criterion [C44(P)–P] > 0 and predicted the presently-not-verified transition pressures for MgO and (Mg1−x, Fex)O.
Improving the color gamut of gold nanostructures using vertical tandem nano-disks
Authors: Briones Edgar
Published: October 2024

Metallic nanoparticles have been used in structural coloration applications since they provide an alternative for the synthesis of color filters, with extended color gamut, enhanced color saturation, and brightness. These optical properties can be further improved when integrating nanoparticles into coupled dimers that give rise to enhanced hybridized plasmon resonances. In this contribution, gold nano-disks are split into Au/SiO2/Au layered structures to enhance its plasmon resonances and evaluate its improved performance as reflective color filters. To do so, the reflectance spectra of the layered disks were obtained with numerical simulations, identifying high amplitude peaks in the visible band and low-amplitude peaks in the near infrared one, related to the hybridized resonances. By choosing the appropriate size of the intermediate dielectric and metallic layers, as well as the near-field coupling, peaks can be tuned along the visible and near infrared bands, respectively. The chromatic coordinates of the addressed nanostructures obtained from the reflectance spectra show that the nanostructures hold color gamut that extends toward magenta, orange, yellowish, and reddish shades of colors.
The mechanism of degradation and failure in NiO/
β
-Ga2O3 heterojunction diodes induced by the high-energy ion irradiation
Authors: He Song , Wen Junpeng , Liu Jinyang , Hao Weibing , Zhou Xuanze , Wang Tianqi , Zhang Zhengliang , Liu Jianli , Xu Guangwei , Yang Shu , Long Shibing
Published: October 2024

This work investigated the single-event effects (SEE) of NiO/β-Ga2O3 heterojunction diodes (HJDs) irradiated by 1.86 GeV tantalum ions with linear energy transfer over 80 MeV cm2/mg. The HJDs exhibited radiation responses with the early single-event leakage current (SELC) degradation until the fatal single-event burnout (SEB) failure, which was far below their breakdown voltages. Meanwhile, the surface morphology revealed the SELC damage expressed as burnout of topside NiO and metal stacks, while the SEB damage was observed as a burned hole in the β-Ga2O3 epitaxial layer. According to technology computer aided design simulations, the thicker p-type region in HJDs could further alleviate the electric field crowding effect exacerbated by the heavy-ion strike because of the extension of charge distribution in the p-type region. The SEB threshold was raised to 250 V by thickening the NiO layer to 300 nm. As for the SELC degradation process along with the burnout of topside stacks in HJDs, we supposed the probable reason was the intolerance of NiO to the high electric field under the SEE. This paper analyzed the SEE mechanism in β-Ga2O3 diodes and paved the way for heavy-ion irradiation hardening.
Free radical detection in precision-cut mouse liver slices with diamond-based quantum sensing
Authors: Zhang Yue , Sigaeva Alina , Elías-Llumbet Arturo , Fan Siyu , Woudstra Willem , de Boer Rinse , Escobar Elkin , Reyes-San-Martin Claudia , Kisabacak Robin , Oosterhuis Dorenda , Gorter Alan R. , Coenen Britt , Perona Martinez Felipe P. , van den Bogaart Geert , Olinga Peter , Schirhagl Romana
Published: October 2024

Free radical generation plays a key role in many biological processes including cell communication, maturation, and aging. In addition, free radical generation is usually elevated in cells under stress as is the case for many different pathological conditions. In liver tissue, cells produce radicals when exposed to toxic substances but also, for instance, in cancer, alcoholic liver disease and liver cirrhosis. However, free radicals are small, short-lived, and occur in low abundance making them challenging to detect and especially to time resolve, leading to a lack of nanoscale information. Recently, our group has demonstrated that diamond-based quantum sensing offers a solution to measure free radical generation in single living cells. The method is based on defects in diamonds, the so-called nitrogen-vacancy centers, which change their optical properties based on their magnetic surrounding. As a result, this technique reveals magnetic resonance signals by optical means offering high sensitivity. However, compared to cells, there are several challenges that we resolved here: Tissues are more fragile, have a higher background fluorescence, have less particle uptake, and do not adhere to microscopy slides. Here, we overcame those challenges and adapted the method to perform measurements in living tissues. More specifically, we used precision-cut liver slices and were able to detect free radical generation during a stress response to ethanol, as well as the reduction in the radical load after adding an antioxidant.
Manipulating a host-native microbial strain compensates for low microbial diversity by increasing weight gain in a wild bird population
Authors: Somers Shane E. , Davidson Gabrielle L. , Mbandlwa Philiswa , McKeon Caroline M. , Stanton Catherine , Ross R. Paul , Quinn John L.
Published: October 2024

Empirical studies from laboratory systems and humans show that the gut microbiota is linked to host health. Similar evidence for effects on traits linked to fitness in nature is rare, not least because experimentally manipulating the gut microbiota is challenging. We isolated, characterized, and cultured a bacterial strain,
Lactobacillus kimchicus
APC4233, directly from a wild bird (the great tit
Parus major
) and provided it as a self-administered dietary supplement. We assessed the impact of the treatment on the host microbiota community, on weight, and tested whether the treatment affected a previous result linking microbiota alpha diversity to weight in nestlings. The treatment dramatically increased
L. kimchicus
abundance in the gut microbiota and increased alpha diversity. This effect was strongest in the youngest birds, validating earlier findings pointing to a brief developmental window when the gut microbiota are most sensitive. In time-lagged models, nestling weight was higher in the treatment birds suggesting
L. kimchicus
may have probiotic potential. There was also a positive time-lagged relationship between diversity and weight in control birds but not in the treatment birds, suggesting
L. kimchicus
helped birds compensate for low alpha diversity. We discuss why ecological context is likely key when predicting impacts of the microbiome. The manipulation of the gut microbiota with a host native strain in this wild population provides direct evidence for the role of the microbiota in the ecology and evolution of natural populations.