bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of bridge height on airflow and aeolian sand flux near surface along the Qinghai-Tibet Railway, China
Authors: Xue Chengjie , Zhang Kecun , An Zhishan , Xiao Jianhua , Zhang Hongxue , Pan Jiapeng
Published: July 2024

In this work, we studied the near-surface flow field structure of railway bridges with different heights through field investigation and wind tunnel simulation experiments. Meanwhile, we simulated the distribution of sand accumulation around a bridge via CFD software based on the sand accumulation around the Basuoqu bridge in the Cuona Lake section of the Qinghai–Tibet Railway. Results show that the sand around this railway bridge is mainly from the lake sediment on the west side of the railway and the weathered detritus on the east side. The height of the railway bridge in the sandy area affects the distribution of the near-surface flow field and the variation in speed on both sides of the bridge. The wind speed trough on both sides of the 6 m high bridge is higher, and the horizontal distance between the wind speed trough and the bridge section is 1.5 times that of the 3 m high bridge. Wind speed attenuates in a certain range on the windward and leeward sides of the bridge, forming an aeolian area; under the beam body, it is affected by the narrow tube effect, forming a wind erosion area. The height of the bridge determines its sand transport capacity. Under certain wind conditions, the overhead area at the bottom of the 3 m high bridge and its two sides do not have the sand transport capacity, so sand accumulates easily. Nevertheless, the sand accumulation phenomenon gradually disappears with the increase in bridge clearance height. The objectives of this study are to reveal the formation mechanism of sand damage for railway bridges, provide theoretical support for the scientific design of railway bridges in sandy areas, and formulate reasonable railway sand prevention measures to ensure the safety of railway running, which have certain theoretical significance and practical value.
Evaluation of cosmetic outcomes in breast reconstruction patients undergoing radiotherapy using an anomaly generative adversarial network model
Authors: Lee Choong-won , Shin Kyung Hwan , Chang Ji Hyun , Jang Bum-Sup
Published: July 2024

Considering the rising prevalence of breast reconstruction followed by radiotherapy (RT), evaluating the cosmetic impact of RT is crucial. Currently, there are limited tools for objectively assessing cosmetic outcomes in patients who have undergone reconstruction. Therefore, we validated the cosmetic outcome using a previously developed anomaly Generative Adversarial Network (GAN)-based model and evaluated its utility. Between January 2016 and December 2020, we collected computed tomography (CT) images from 82 breast cancer patients who underwent immediate reconstruction surgery followed by radiotherapy. Among these patients, 38 received immediate implant insertion, while 44 underwent autologous breast reconstruction. Anomaly scores (AS) were estimated using an anomaly GAN model at pre-RT, 1st follow-up, 1-year (Post-1Y) and 2-year (Post-2Y) after RT. Subsequently, the scores were analyzed in a time-series manner, considering reconstruction types (implant versus autologous), RT techniques, and the incidence of major complications. The median age of the patients was 46 years (range 29–62). The AS between Post-1Y and Post-2Y demonstrated a positive relationship (coefficient 0.515, P < 0.001). The AS was significantly associated with objective cosmetic indices, namely Breast Contour Difference (P = 0.009) and Breast Area Difference (P = 0.004), at both Post-1Y and Post-2Y. Subgroup analysis stratified by type of breast reconstruction revealed significantly higher AS values in patients who underwent prosthetic implant insertion compared to those with autologous reconstruction at all follow-up time points (1st follow-up, P = 0.001; Post-1Y, P < 0.001; and Post-2Y, P < 0.001). A threshold AS of ≥ 1.9 was associated with a 10% predicted risk of developing major complications. The feasibility of an AS generated by a GAN model for predicting both cosmetic outcomes and the likelihood of complications following RT has been successfully validated. Further investigation involving a larger patient cohort is warranted.
Numerical analysis of blood flow in the abdominal aorta under simulated weightlessness and earth conditions
Authors: Żyłka Marta , Górski Grzegorz , Żyłka Wojciech , Gala-Błądzińska Agnieszka
Published: July 2024

Blood flow through the abdominal aorta and iliac arteries is a crucial area of research in hemodynamics and cardiovascular diseases. To get in to the problem, this study presents detailed analyses of blood flow through the abdominal aorta, together with left and right iliac arteries, under Earth gravity and weightless conditions, both at the rest stage, and during physical activity. The analysis were conducted using ANSYS Fluent software. The results indicate, that there is significantly less variation in blood flow velocity under weightless conditions, compared to measurement taken under Earth Gravity conditions. Study presents, that the maximum and minimum blood flow velocities decrease and increase, respectively, under weightless conditions. Our model for the left iliac artery revealed higher blood flow velocities during the peak of the systolic phase (systole) and lower velocities during the early diastolic phase (diastole). Furthermore, we analyzed the shear stress of the vessel wall and the mean shear stress over time. Additionally, the distribution of oscillatory shear rate, commonly used in hemodynamic analyses, was examined to assess the effects of blood flow on the blood vessels. Countermeasures to mitigate the negative effects of weightlessness on astronauts health are discussed, including exercises performed on the equipment aboard the space station. These exercises aim to maintain optimal blood flow, prevent the formation of atherosclerotic plaques, and reduce the risk of cardiovascular complications.
Well-modulated interfacial ion transport enables d-sorbitol/PEDOT:PSS fibers to sense brain electrophysiological signals in vivo
Authors: Xu Tianci
Published: July 2024

At a d-sorbitol/PEDOT:PSS weight ratio of 6, the fiber can be modulated to the optimum for electrophysiological sensing, in terms of the morphology, crystallization, diffusion resistance, interfacial capacitance, and potential stability.
High-throughput label-free opioid receptor binding assays using an automated desorption electrospray ionization mass spectrometry platform
Authors: Feng Yunfei , Morato Nicolás M. , Huang Kai-Hung , Lin Mina , Cooks R. Graham
Published: July 2024

An automated high-throughput (1 Hz) ambient mass spectrometry platform is utilized to perform label-free receptor binding assays of both known and newly synthesized opioid analogues whose functionalization was achieved using the same system.
Correction: A detailed study of the electronic and optical properties of germanium nanotubes
Authors: Liu Hsin-Yi , Chiu Yu-Huang , Wu Jhao-Ying
Published: July 2024

Correction for ‘A detailed study of the electronic and optical properties of germanium nanotubes’ by Hsin-Yi Liu et al., Phys. Chem. Chem. Phys., 2024, 26, 17830–17837, https://doi.org/10.1039/D4CP00812J.
Nucleic acid-based wearable and implantable electrochemical sensors
Authors: Ye Cui , Lukas Heather , Wang Minqiang , Lee Yerim , Gao Wei
Published: July 2024

This review discusses the advancements, sensor design, and challenges in creating wearable and implantable nucleic acid-based sensors for personalized healthcare through real-time biomarker analysis in biofluids.
Multi-layered heterogeneous interfaces created in Co0.85Se@Ni3S4/NF to enhance supercapacitor performances by multi-step alternating electrodeposition
Authors: Zhang Chunyan , Yang Jinkun , Li Hang , Su Mengfei , Xiong Boru , Gao Feng , Lu Qingyi
Published: July 2024

A multi-step alternating electrochemical deposition (MAED) method was proposed to deposit Co0.85Se and Ni3S4 nanosheets on a nickel foam (NF), forming a special alternate layer-by-layer structure with multilayer heterogeneous interfaces.
Co(iii) complexes of the pentadentate NHC ligand PY4Im: carbene-induced trans influences and the non-disappearing 13C NMR peak
Authors: Ismael Fouad , Fleming Cassandra L. , Christopher Timothy D. , Söhnel Tilo , Zhou Yuchen , Krenske Elizabeth H. , Gahan Lawrence R. , Blackman Allan G.
Published: July 2024

The carbene carbon of the multidentate ligand PY4Im induces a consistent trans influence in a number of Co(iii) complexes.
Ultra-sensitive determination of mercury in flue gas by atmospheric pressure glow discharge atomic emission spectrometry coupled with gold amalgam enrichment
Authors: Gao Meng , Rong Rong , Cai Zhaoqing , Wang Zheng
Published: July 2024

In this work, we developed a highly sensitive, fast and convenient procedure for the determination of mercury in flue gas based on GA-APGD-AES.
Hydrogel films prepared from plant-seed mucilage: an emerging biopolymer for therapeutic applications
Authors: Ghosh Debolina , Das Gopal
Published: July 2024

Hydrogel films were prepared using mucoadhesive extracts from fenugreek and flax seeds, and their versatility for a range of biological uses – such as anti-inflammatory, anti-diabetic, anti-oxidant, and anti-microbial applications was examined.
Tensile force field plays a crucial role in local invasion of tumor cells through a mechano-chemical coupling mechanism
Authors: Meng Jianfeng , Xu Xiangyu , Jiang Chaohui , Xia Peng , Xu Pengfei , Tian Liangfei , Xu Yingke , Li Dechang , Tan Youhua , Ji Baohua
Published: July 2024

Cell polarization and migration during tumor cell invasion are closely associated with the tensional force field in the fiber network, which revealed a mechano-chemical coupling mechanism at the cellular level of the tumor invasion process.
A micro-dome array triboelectric nanogenerator with a nanocomposite dielectric enhancement layer for wearable pressure sensing and gait analysis
Authors: Aamir Jan Agha , Kim Seungbeom , Kim Seok
Published: July 2024

A micro-dome array triboelectric nanogenerator with a nanocomposite dielectric enhancement layer for wearable pressure sensing and gait analysis.
Influence of Cesarean Section Scar on the Mean Pulsatility Index of the Uterine Artery Doppler between 20 and 34 Weeks of Gestation
Authors: Peixoto Alberto Borges , Guimarães Débora Silva , Maia e Cruz Letícia , de Oliveira Maria Laura , Macedo Filho Saulo da Silva , de Souza Luiz Ronan Marquez Ferreira , Tonni Gabriele , Araujo Júnior Edward
Published: July 2024

The aim of this study was to assess the influence of the cesarean section scars on the mean pulsatility index (PI) of the uterine artery Doppler between 20 and 34 weeks of gestation. A secondary objective was to assess the association between previous cesarean section and adverse maternal/perinatal outcomes.

A retrospective cohort study was conducted with pregnant women who had their deliveries between March 2014 and February 2023. PI of the uterine arteries Doppler was performed transvaginally between 20–24 weeks and transabdominally between 28–34 weeks. The following variables were considered adverse perinatal outcomes: birth weight < 10th percentile for gestational age, preeclampsia, premature birth, placental abruption, perinatal death, postpartum hemorrhage, neonatal intensive care unit (NICU) admission.

A total of 479 pregnant women were included in the final statistical analysis, being that 70.6% (338/479) had no (Group I) and 29.4% (141/479) had at least one previous cesarean section (Group II). Pregnant women with a previous cesarean had higher median of mean PI (1.06 vs. 0.97, p = 0.044) and median MoM of mean PI uterine arteries Doppler (1.06 vs. 0.98, p = 0.037) than pregnant women without previous cesarean section at ultrasound 20–24 weeks. Pregnant women with a previous cesarean section had higher median of mean PI (0.77 vs. 0.70, p < 0.001) and mean MoM PI uterine arteries Doppler (1.08 vs. 0.99, p < 0.001) than pregnant women without previous cesarean section at ultrasound 28–34 weeks. Pregnant women with ≥ 2 previous cesarean sections had a higher median of mean PI uterine arteries Doppler than those with no previous cesarean sections (1.19 vs. 0.97, p = 0.036). Group II had a lower risk of postpartum hemorrhage (aPR 0.31, 95% CI 0.13–0.75, p = 0.009) and
composite neonatal outcome (aPR 0.66, 95% CI 0.49–0.88, p = 0.006). Group II had a higher risk of APGAR score at the 5th minute < 7 (aPR 0.75, 95% CI 1.49–51.29, p = 0.016).

The number of previous cesarean sections had a significant influence on the mean PI uterine arteries Doppler between 20–24 and 28–34 weeks of gestation. Previous cesarean section was an independent predictor of postpartum hemorrhage and APGAR score at the 5th minute < 7. Pregnancy-associated arterial hypertension and number of previous deliveries influenced the risk of composite neonatal outcome, but not the presence of previous cesarean section alone.
Minimally Invasive Epilepsy Surgery
Authors: Nordli III Douglas R. , Taha Mohamed , Freund Brin , Nordli Douglas R. , Galan Fernando
Published: July 2024

Surgery remains a critical and often necessary intervention for a subset of patients with epilepsy. The overarching objective of surgical treatment has consistently been to enhance the quality of life for these individuals, either by achieving seizure freedom or by eliminating debilitating seizure types. This review specifically examines minimally invasive surgical approaches for epilepsy. Contemporary advancements have introduced a range of treatments that offer increased safety and efficacy compared to traditional open resective epilepsy surgeries. This manuscript provides a comprehensive review of these techniques and technologies.
Biomechanical Principles of Intramedullary Nails in Veterinary and Human Medicine
Authors: Sisk Morgan R. , Yang Lydia C. , Paul Kyle D. , Elphingstone Joseph W. , Brabston Eugene W. , Ponce Brent A. , Martin Elliott C. , Corriveau Kayla M.
Published: July 2024

Intramedullary nails are specialized metal rods inserted into the medullary cavity of a fractured bone and secured to reduce load on the fracture site, provide stability, and permit healing. The purpose of this review is to highlight the biomechanics of orthopaedic intramedullary nailing, as well as discuss the biomechanical considerations that have shaped implant design and fixation technique in veterinary and human medicine. Relevant studies were included from the PubMed database and Google Scholar for discussion on the basic science and nail design of intramedullary nails. Implant design and implementation continues to progress, with new innovative designs currently under investigation. A lack of consensus remains on the superior implant material. Recent studies, particularly in human populations, have supported the use of reaming based on reoperation rates, nonunion rates, and dynamization. Design modifications, such as the expandable intramedullary nails and angle-stable interlocking designs, have been investigated as methods of improving cortical contact and resisting torsional stress. Intramedullary nailing is a valuable stabilization technique for long bone fractures across a variety of species. The technology continues to undergo design improvements in both veterinary and human medicine.
15.3.5 Synthesis of Quinoline Derivatives by Modification of a Methyl Substituent at the C2 or C8 Position
Authors: Sharma U. , Parmar D. , Sumit  , Manisha
Published: July 2024

This review is an update contribution covering methodologies reported between the years 2005–2022 for the side-chain modification of quinolines. The focus is on the literature published for the transformation of a “methyl group” at the C2 and C8 position of quinoline. Various metal-catalyzed and metal-free protocols for C(sp3)—H functionalization are described.
Building Teamwork: The Synergies of Structural Engineering and Construction Management
Authors: Larbi Jelian ,   American Society of Civil Engineers
Published: July 2024

With rapid advances in materials, modeling, and manufacturing technologies, engineers must consider several additional factors to achieve a sustainable design
Characterizing the geometry of the Kirkwood–Dirac-positive states
Authors: Langrenez C. , Arvidsson-Shukur D. R. M. , De Bièvre S.
Published: July 2024

The Kirkwood–Dirac (KD) quasiprobability distribution can describe any quantum state with respect to the eigenbases of two observables A and B. KD distributions behave similarly to classical joint probability distributions but can assume negative and nonreal values. In recent years, KD distributions have proven instrumental in mapping out nonclassical phenomena and quantum advantages. These quantum features have been connected to nonpositive entries of KD distributions. Consequently, it is important to understand the geometry of the KD-positive and -nonpositive states. Until now, there has been no thorough analysis of the KD positivity of mixed states. Here, we investigate the dependence of the full convex set of states with positive KD distributions on the eigenbases of A and B and on the dimension d of the Hilbert space. In particular, we identify three regimes where convex combinations of the eigenprojectors of A and B constitute the only KD-positive states: (i) any system in dimension 2; (ii) an open and dense probability one set of bases in dimension d = 3; and (iii) the discrete-Fourier-transform bases in prime dimension. Finally, we show that, if for example d = 2m, there exist, for suitable choices of A and B, mixed KD-positive states that cannot be written as convex combinations of pure KD-positive states. We further explicitly construct such states for a spin-1 system.
A counter-gravity casting system for in situ high-speed synchrotron x-ray imaging characterization
Authors: Wang Haojie , Chen Zhongfeng , Xiong Lianghua , Zhang Shuya , Yin Xiaoyu , Wang Feixiang , Zhang Haipeng , Xie Honglan , He Lin , Du Dafan , Dong Anping , Xiao Tiqiao , Sun Baode
Published: July 2024

Counter-gravity casting (CGC) aims to eliminate turbulent melt flow and defect formation during filling and subsequent solidification by pushing high-temperature melt into the mold cavity against gravity with regulated pressure. However, limited by the opaqueness of molten metals and the complexity of the CGC apparatus, it is extremely difficult to directly quantify the high-velocity mold filling and pressurized solidification in real-time. Here, we report the design and characterization of a CGC system capable of in situ monitoring of mold filling and subsequent solidification processes in the synchrotron beamlines by deploying a high-energy, high-speed synchrotron x-ray imaging technique. The high-velocity melt flow and dendrite growth during pressurized solidification have been quantified for systematical process parameter analysis by investigating time-resolved x-ray images of an exemplary Al–Cu alloy. The high-speed imaging results demonstrate that the in situ CGC system provides a useful way to better understand the fundamentals of mold filling, pressurized solidification, and experimental inputs for high-fidelity modeling in scientific and industrial applications.
Phonon-assisted charge carriers thermalization in semiconductor Si and metallic silicide NiSi2, CoSi2: A non-adiabatic molecular dynamics study
Authors: Luo Kun , Gan Weizhuo , Hou Zhaozhao , Zhan Guohui , Xu Lijun , Liu Jiangtao , Wu Zhenhua
Published: July 2024

Recently, the cold source field-effect transistor (CSFET) has emerged as a promising solution to overcome Boltzmann tyranny in its ballistic regime, offering a steep-slope subthreshold swing (SS) of less than 60 mV/decade. However, challenges arise due to scattering, particularly from inelastic scattering, which can lead to significant degradation in SS through cold carrier thermalization. In this study, we delve into the theoretical investigation of the electronic excitation/relaxation dynamic process using the state-of-the-art nonadiabatic molecular dynamics (NAMD) method. The mixed quantum-classical NAMD proves to be a powerful tool for comprehensively analyzing cold carrier thermalization and transfer processes in semiconductor Si, as well as metallic silicides (NiSi2 and CoSi2). The approach of mixed quantum-classical NAMD takes into account both carrier decoherence and detailed balance, enabling the calculation of thermalization factors, relaxation times, scattering times, and scattering rates at various energy levels. The thermalization of carriers exhibits a gradual increase from low to high energy levels. Achieving partial thermalization from the ground state to reach the thermionic current window occurs within a sub-100 fs time scale. Full thermalization across the entire energy spectrum depends sensitively on the barrier height, with the scattering rate exponentially decreasing as the energy of the out-scattering state increases. Notably, the scattering rate of NiSi2 and CoSi2 is two orders of magnitude higher than that of Si, attributed to their higher density of states compared to Si. This study not only provides insights into material design for low-power tunnel field-effect transistors but also contributes valuable information for advancing CSFET in emerging technologies.
The relationship between threshold power of wave mode transition and tube radius in argon helicon discharge
Authors: Cui Ying , Zhang Tianliang , He Feng , Xia Zhangyu , Ouyang Jiting
Published: July 2024

We report in this Letter a geometric similarity of threshold radio frequency (RF) power absorbed by the helicon wave coupled mode in argon helicon discharge. Helicon plasma was excited by a half-helical antenna in tubes of different radii at a pressure of 0.3 Pa. Plasma density was measured by using a Langmuir probe, and wave structure was measured by a B-dot probe. The results show that the threshold powers for triggering helicon wave mode are proportional to the tube cross sections, and the plasma densities at the transition point are the same, indicating a geometric scaling law between the RF power and the tube size. This similarity of threshold power might provide a comparison of results in different systems.
Suppression of negative transfer in motor imagery brain–computer interface based on mutual information and Pearson correlation coefficient
Authors: Zhu Fenfang , Cai Jicheng , Zheng Hao , Liang Zilin , Zhang Yue
Published: July 2024

The focus of this paper is on the main challenges in brain–computer interface transfer learning: how to address data characteristic length and the source domain sample selection problems caused by individual differences. To overcome the negative migration that results from feature length, we propose a migration algorithm based on mutual information transfer (MIT), which selects effective features by calculating the entropy value of the probability distribution and conditional distribution, thereby reducing negative migration and improving learning efficiency. Source domain participants who differ too much from the target domain distribution can affect the overall classification performance. On the basis of MIT, we propose the Pearson correlation coefficient source domain automatic selection algorithm (PDAS algorithm). The PDAS algorithm can automatically select the appropriate source domain participants according to the target domain distribution, which reduces the negative migration of participant data among the source domain participants, improves experimental accuracy, and greatly reduces training time. The two proposed algorithms were tested offline and online on two public datasets, and the results were compared with those from existing advanced algorithms. The experimental results showed that the MIT algorithm and the MIT + PDAS algorithm had obvious advantages.
Enhancing thermal-hydraulic performance in curved pipes through optimal radial fin placement: A numerical investigation
Authors: Ghaemian Amin , Maghrebi Mohammad-Javad
Published: July 2024

Increasing heat transfer in straight pipes, particularly in applications like heat exchangers, can be achieved by incorporating fins into the pipe wall. However, in curved pipes, the presence of more intricate flows resulting from centrifugal forces can alter this effect. The current study investigates how both the height and angular position of radial fins simultaneously influence the flow patterns within curved pipes. Adjusting the placement of radial fins is identified as a cost-effective and strategic approach to improve both the hydrodynamic and thermal efficiency in curved pipe systems. The numerical analysis focuses on studying laminar, incompressible flow in curved tubes with radial fins. The mass, momentum, and energy conservation equations in toroidal coordinates were discretized with the second-order finite difference method on a staggered grid, followed by their solution through the projection algorithm. The results indicate that adapting the angular position of the fins improves the thermal-hydraulic performance by 51.8%, 48.4%, 36.3%, and 20.6% for one to four fins, respectively. These changes are closely related to the behavior of the secondary flows. Furthermore, altering the height of the fins reveals that for three fins within the tube, the most optimal fin height is half of the tube radius. In other cases, a fin height equal to 0.7 multiplied by the tube radius provides the highest performance. From the numerical results, it is found that the primary factor affecting the heat transfer rate in curved pipes is the strength of secondary motions, while the generation of friction is influenced only by the axial velocity.
Photoelectric charging and lofting of dust particles on a conducting surface with external electric fields
Authors: Taylor Kelyan , Elliott Amanda , Wang Xu , Horányi Mihály , Schmidt Rudiger , Wollmann Daniel , Wiesner Christoph , Belanger Philippe
Published: July 2024

We present a laboratory study of photoelectric charging of dust particles and their lofting on a conducting surface in the presence of external electric fields. Insulating particles with diameter <45 μm are dispersed on a conducting surface exposed to ultraviolet (UV) light. In addition to the UV exposure, a positive or negative external electric field is applied. Independent of the orientation of the external electric field, the dust particles are found to be positively charged but with different mechanisms. It is shown that the orientation of the external electric field controls the dynamics of photoelectrons emitted from the dust particles and the conducting substrate surface. Distinctly different lofting results are shown between these two electric field cases. The results provide insight for understanding dust charging and release and helping develop mitigation solutions in particle accelerators, semiconductor manufacturing, fusion reactors, and space exploration to planetary bodies.
Modulation instability of magnetosonic waves in semiconducting quantum plasma considering Fermi degenerate pressure, exchange correlation potential, and Bohm potential
Authors: Sharma Krishna , Turi Jyoti , Ali Rustam , Deka Utpal
Published: July 2024

This study investigates the modulation instability of magnetosonic waves in a semiconducting quantum plasma system. Utilizing the quantum hydrodynamic model, we derive the nonlinear Schrödinger equation and its solution through the reductive perturbation technique. The growth rate of modulation instability for magnetosonic waves has been derived. This study incorporates various quantum corrections, including Fermi degenerate pressure, exchange-correlation potential, and Bohm potential. We study the bright soliton profiles of magnetosonic waves, and additionally, we conduct graphical analyses of the linear dispersion relation and the product of the dispersive coefficient (P) and nonlinear coefficient (Q) of the nonlinear Schrödinger equation. It has been found that magnetosonic waves exhibit modulation instability within specific parameter ranges of the semiconductor plasma and at certain wavelength regimes. Further, we present a comparative study between GaSb and InSb semiconducting plasma systems. The exchange-correlation potential and Fermi degenerate pressure have significantly impacted the modulation instability growth rate, whereas the effect of the Bohm potential is much lower.
Statistics of kinetic and thermal energy dissipation rates in two-dimensional thermal vibrational convection
Authors: Guo Xili , Qin Peijiang , Wu Jianzhao , Wang Bofu , Chong Kai Leong , Zhou Quan
Published: July 2024

We investigate the statistical properties of kinetic ϵu and thermal ϵθ energy dissipation rates in two-dimensional (2D) thermal vibrational convection (TVC). Direct numerical simulations were conducted in a unit aspect ratio box across a dimensionless angular frequency range of 103≤ω≤107 for amplitudes 0.001≤a≤0.1, with a fixed Prandtl number of 4.38. Our findings indicate ϵu is primarily associated with the characteristics of the vibration force, while ϵθ is more related to the large-scale columnar structures. Both energy dissipation rates exhibit a power-law relationship with the oscillational Reynolds number Reos. ϵu exhibits a scaling relation as ⟨ϵu⟩V,t∼a−1Reos0.93±0.01, while ϵθ exhibits two distinct scaling behaviors, i.e., ⟨ϵθ⟩V,t∼a−1Reos1.97±0.04 for ReosReos,cr, where the fitted critical oscillational Reynolds number is approximately Reos,cr≈80. The different scaling of ⟨ϵθ⟩V,t is determined by the competition between the thermal boundary layer and the oscillating boundary layer. Moreover, the probability density functions (PDFs) of both dissipation rates deviate significantly from the lognormal distribution and exhibit a bimodal shape. By partitioning the contributions from the boundary layer and bulk regions, it is shown that the bulk contributes to the small and moderate dissipation rates, whereas the high dissipation rates are predominantly contributed by the boundary layer. As Reos increases, the heavy tail of the PDFs becomes more pronounced, revealing an enhanced level of small-scale intermittency. This small-scale intermittency is mainly caused by the influence of BL due to vibration. Our study provides insight into the small-scale characteristics of 2D TVC, highlighting the non-trivial scaling laws and intermittent behavior of energy dissipation rates with respect to vibration intensity.
Anharmonic and quantum effects in Pm3̄ AlM(M = Hf, Zr)H6 under high pressure: A first-principles study
Authors: Hou Pugeng , Ma Yao , Pang Mi , Cai Yongmao , Shen Yuhua , Xie Hui , Tian Fubo
Published: July 2024

First-principles calculations were employed to investigate the impact of quantum ionic fluctuations and lattice anharmonicity on the crystal structure and superconductivity of Pm3̄ AlM(M = Hf, Zr)H6 at pressures of 0.3–21.2 GPa (AlHfH6) and 4.7–39.5 GPa (AlZrH6) within the stochastic self-consistent harmonic approximation. A correction is predicted for the crystal lattice parameters, phonon spectra, and superconducting critical temperatures, previously estimated without considering ionic fluctuations on the crystal structure and assuming the harmonic approximation for lattice dynamics. The findings suggest that quantum ionic fluctuations have a significant impact on the crystal lattice parameters, phonon spectra, and superconducting critical temperatures. Based on our anharmonic phonon spectra, the structures will be dynamically stable at 0.3 GPa for AlHfH6 and 6.2 GPa for AlZrH6, ∼6 and 7 GPa lower than pressures given by the harmonic approximation, respectively. Due to the anharmonic correction of their frequencies, the electron–phonon coupling constants (λ) are suppressed by 28% at 11 GPa for AlHfH6 and 22% at 30 GPa for AlZrH6, respectively. The decrease in λ causes Tc to be overestimated by ∼12 K at 11 GPa for AlHfH6 and 30 GPa for AlZrH6. Even if the anharmonic and quantum effects are not as strong as those of Pm3̄n-AlH3, our results also indicate that metal hydrides with hydrogen atoms in interstitial sites are subject to anharmonic effects. Our results will inevitably stimulate future high-pressure experiments on synthesis, structural, and conductivity measurements.
Spin-torque ferromagnetic resonance based on current-induced impedance
Authors: Kobayashi Yuta , Itoh Tomoya , Hisatomi Ryusuke , Moriyama Takahiro , Shiota Yoichi , Fan Xin , Ono Teruo
Published: July 2024

Spin-torque ferromagnetic resonance (ST-FMR) has been widely used for measuring damping-like spin–orbit torques in magnetic bilayers. Typically, the ratio between the damping-like and field-like spin–orbit torques are extrapolated based on the ferromagnetic resonance line shapes. However, when the field-like spin–orbit torque is unknown, the line shape analysis may lead to errors in extrapolating the damping-like spin–orbit torque. Here, we propose a modified version of the ST-FMR that allows extrapolation of both damping-like and field-like torques independently. By introducing an alternating current to the sample, the RF impedance is modulated, allowing detection via the reflected microwave. We show that the extrapolated field-like and damping-like torques in Py/Pt samples are consistent with the technique measuring current-induced linewidth and resonance field change but have much better signal-to-noise ratio. Our proposed method paves a way for more accurate measurement of spin–orbit torques.
Hydrogen exposure-enhanced superconductivity transition in FeSe/SrTiO3 monolayer
Authors: Xue Cheng-Long , Dou Li-Guo , Xu Yong-Jie , Li Qi-Yuan , Yuan Qian-Qian , Jia Zhen-Yu , Li Shao-Chun
Published: July 2024

Interface-enhanced superconductivity in FeSe/SrTiO3 (FeSe/STO) monolayers provides the record for the highest transition temperature (Tc) in iron-based compounds. Long-term post annealing is the commonly adopted recipe to induce the superconductivity transition in the not-superconductive as-grown FeSe/STO monolayer. Here, we developed a kinetic method, i.e., hydrogen exposure followed by gentle annealing, to enhance the superconductivity of the FeSe/STO monolayer. Our approach is more efficient than the long-term post annealing. Scanning tunneling microscopy (STM) characterization demonstrated the so far largest superconducting gap of ∼22 mV, indicating an enhanced superconductivity. We believe that the hydrogen-induced lattice Fe diffusion facilitates to remove the interfacial excess Se atoms fatal to the superconductivity, resulting in the formation of a second layer FeSe. The subsequent annealing helps to annihilate the generated Fe vacancies and, thus, enhance the superconductivity in the FeSe/STO monolayer.
Stearoylation cycle regulates the cell surface distribution of the PCP protein Vangl2
Authors: Ying Jiafu , Yang Yinghong , Zhang Xuanpu , Dong Ze , Chen Baoen
Published: July 2024

Defects in planar cell polarity (PCP) have been implicated in diverse human pathologies. Vangl2 is one of the core PCP components crucial for PCP signaling. Dysregulation of Vangl2 has been associated with severe neural tube defects and cancers. However, how Vangl2 protein is regulated at the posttranslational level has not been well understood. Using chemical reporters of fatty acylation and biochemical validation, here we present that Vangl2 subcellular localization is regulated by a reversible S-stearoylation cycle. The dynamic process is mainly regulated by acyltransferase ZDHHC9 and deacylase acyl-protein thioesterase 1 (APT1). The stearoylation-deficient mutant of Vangl2 shows decreased plasma membrane localization, resulting in disruption of PCP establishment during cell migration. Genetically or pharmacologically inhibiting ZDHHC9 phenocopies the effects of the stearoylation loss of Vangl2. In addition, loss of Vangl2 stearoylation enhances the activation of oncogenic Yes-associated protein 1 (YAP), serine-threonine kinase AKT, and extracellular signal-regulated protein kinase (ERK) signaling and promotes breast cancer cell growth and HRas G12V mutant (HRas
V12
)-induced oncogenic transformation. Our results reveal a regulation mechanism of Vangl2, and provide mechanistic insight into how fatty acid metabolism and protein fatty acylation regulate PCP signaling and tumorigenesis by core PCP protein lipidation.
Control of G protein–coupled receptor function via membrane-interacting intrinsically disordered C-terminal domains
Authors: Mancinelli Chiara D. , Marx Dagan C. , Gonzalez-Hernandez Alberto J. , Huynh Kevin , Mancinelli Lucia , Arefin Anisul , Khelashvilli George , Levitz Joshua , Eliezer David
Published: July 2024

G protein–coupled receptors (GPCRs) control intracellular signaling cascades via agonist-dependent coupling to intracellular transducers including heterotrimeric G proteins, GPCR kinases (GRKs), and arrestins. In addition to their critical interactions with the transmembrane core of active GPCRs, all three classes of transducers have also been reported to interact with receptor C-terminal domains (CTDs). An underexplored aspect of GPCR CTDs is their possible role as lipid sensors given their proximity to the membrane. CTD–membrane interactions have the potential to control the accessibility of key regulatory CTD residues to downstream effectors and transducers. Here, we report that the CTDs of two closely related family C GPCRs, metabotropic glutamate receptor 2 (mGluR2) and mGluR3, bind to membranes and that this interaction can regulate receptor function. We first characterize CTD structure with NMR spectroscopy, revealing lipid composition-dependent modes of membrane binding. Using molecular dynamics simulations and structure-guided mutagenesis, we then identify key conserved residues and cancer-associated mutations that modulate CTD–membrane binding. Finally, we provide evidence that mGluR3 transducer coupling is controlled by CTD–membrane interactions in live cells, which may be subject to regulation by CTD phosphorylation and changes in membrane composition. This work reveals an additional mechanism of GPCR modulation, suggesting that CTD–membrane binding may be a general regulatory mode throughout the broad GPCR superfamily.
Axialgravisolitons at infinite corner
Authors: Manzoni Federico
Published: July 2024

Gravitational solitons (gravisolitons) are particular exact solutions of Einstein field equation in vacuum build on a given background solution. Their interpretation is not yet fully clear but they contain many of the physically relevant solutions low N-solitons solutions. However, a systematic study and characterization of gravisolitons solution for every N is lacking and their relevance in a theory of quantum gravity is not fully understood. This work aims to investigate and characterize some properties of N-axialsoliton solutions such as their asymptotically behaviour and asymptotic symmetries given minimal assumptions on the background metric. We develop an explicit systematic asymptotically expansion for the N-axialsoliton solution and we compute the leading order of the asymptotic killing vectors. Moreover, in the perspective to better understand the role of gravisolitons in quantum gravity we make a link, and a one of the first explicit test, to the corner symmetry proposal deriving which subalgebra of the universal corner symmetry algebra is generated by the asymptotic Killing vectors of N-axialsoliton solution. In the spirit of the corner proposal, the axialgravisoliton corner symmetry algebra (

agcsa

) can be useful for the quantization of the non-asymptotically flat sector of gravity while, in the spirit of IR triangle, new soft theorems and memory effects could emerge.
Understanding the natural units and their hidden role in the laws of physics
Authors: Humpherys David
Published: July 2024

The natural units of measure lauded by Max Planck more than 100 years ago are underutilized today. Many physical constants, including the Planck constant, the gravitational constant, the speed of light, vacuum permittivity, and vacuum permeability consist of natural units in their unit dimensions. The natural units are present in all formulas containing these constants. The defining characteristic of the natural units is an alignment of unit values at the Planck scale. This alignment gives a computational basis of proportionality from which the correlated properties and dynamics of elementary particles, including wavelength, period, mass, momentum, and energy, manifest in equal or inversely proportional ratios of the Planck scale. These correlations explain many of the defining equations of quantum mechanics, classical gravity, and electromagnetism.
Comparative analysis of absorption resonances between carbynes and cyclo

[
n
]

carbons
Authors: Payod Renebeth B , Pushkarchuk Aliaxandr L , Michels Dominik L , Lyakhov Dmitry A , Saroka Vasil A
Published: July 2024

Two approaches are presented here to analyze the absorption resonances between carbynes and cyclo

[
n
]

carbons, namely the analytical tight-binding model to calculate the optical selection rules of cumulenic atomic rings and chains and the ab initio time-dependent density functional theory for the optical investigation of polyynic carbon ring and chains. The optical absorption spectra of the carbon ring match that of the finite chain when their eigen energies align following the

N

ring

=
2

N

chain

+
2

rule, which states that the number of atoms in an atomic ring

N

ring

is twice the number of atoms on a finite chain

N

chain

with two additional atoms. Two representative atomic chains are chosen for our numerical calculations, specifically carbynes with

N
=
7

and

8

carbon atoms as optical resonance spectra match to a recently synthesized carbon ring called cyclo[18]carbon. Despite the mismatch in resonance peaks, molecular orbital transitions of both carbynes N = 7 and 8 and cyclo[18]carbon reveal a wave function symmetry change from inversion to reflection and vice versa for allowed molecular orbital transitions, which results in electron density redistribution along the polyynic carbyne axis or the cyclo[18]carbon circumference. Our investigation of the correlation of optical absorption peaks between carbynes and cyclo

[
n
]

carbons is a step towards enhancing the reliability of allotrope identification in advanced molecular device spectroscopy. Moreover, this work could facilitate the non-invasive, rapid and crucial assessment of these sensitive 1D allotropes by providing accurate descriptions of their electronic and optical properties, particularly in controlled synthesis environments.
DiffuseRT: predicting likely anatomical deformations of patients undergoing radiotherapy
Authors: Smolders A , Rivetti L , Vatterodt N , Korreman S , Lomax A , Sharma M , Studen A , Weber D C , Jeraj R , Albertini F
Published: July 2024

Objective. Predicting potential deformations of patients can improve radiotherapy treatment planning. Here, we introduce new deep-learning models that predict likely anatomical changes during radiotherapy for head and neck cancer patients. Approach. Denoising diffusion probabilistic models (DDPMs) were developed to generate fraction-specific anatomical changes based on a reference cone-beam CT (CBCT), the fraction number and the dose distribution delivered. Three distinct DDPMs were developed: (1) the image model was trained to directly generate likely future CBCTs, (2) the deformable vector field (DVF) model was trained to generate DVFs that deform a reference CBCT and (3) the hybrid model was trained similarly to the DVF model, but without relying on an external deformable registration algorithm. The models were trained on 9 patients with longitudinal CBCT images (224 CBCTs) and evaluated on 5 patients (152 CBCTs). Results. The generated images mainly exhibited random positioning shifts and small anatomical changes for early fractions. For later fractions, all models predicted weight losses in accordance with the training data. The distributions of volume and position changes of the body, esophagus, and parotids generated with the image and hybrid models were more similar to the ground truth distribution than the DVF model, evident from the lower Wasserstein distance achieved with the image (0.33) and hybrid model (0.30) compared to the DVF model (0.36). Generating several images for the same fraction did not yield the expected variability since the ground truth anatomical changes were only in 76% of the fractions within the 95% bounds predicted with the best model. Using the generated images for robust optimization of simplified proton therapy plans improved the worst-case clinical target volume V95 with 7% compared to optimizing with 3 mm set-up robustness while maintaining a similar integral dose. Significance. The newly developed DDPMs generate distributions similar to the real anatomical changes and have the potential to be used for robust anatomical optimization.
Present and future of

C

osmo

L

attice
Authors: Figueroa Daniel G , Florio Adrien , Torrenti Francisco
Published: July 2024

We discuss the present state and planned updates of

C

osmo

L

attice, a cutting-edge code for lattice simulations of non-linear dynamics of scalar-gauge field theories in an expanding background. We first review the current capabilities of the code, including the simulation of interacting singlet scalars and of Abelian and non-Abelian scalar-gauge theories. We also comment on new features recently implemented, such as the simulation of gravitational waves from scalar and gauge fields. Secondly, we discuss new extensions of

C

osmo

L

attice that we plan to release publicly. We comment on new physics modules, which include axion-gauge interactions

ϕ
F

F
~

, non-minimal gravitational couplings

ϕ
2

R

, creation and evolution of cosmic-defect networks, and magnetohydrodynamics. We also discuss new technical features, including evolvers for non-canonical interactions, arbitrary initial conditions, simulations in 2+1 dimensions, and higher-accuracy spatial derivatives.
A two-step modeling method for constructing 3D negative Poisson’s ratio materials with high specific strength based on common lattice structures
Authors: Lv Weitao , Li Dong
Published: July 2024

The traditional negative Poisson’s ratio (NPR) structure was basically designed based on concave or rotational mechanisms, resulting in relatively low specific strength and limiting its application. This paper proposed a two-step modeling method to establish a connection between the common lattice structures and NPR structures, which can obtain NPR structures with high specific strength. The models with different triaxial compression ratios were obtained through triaxial compression FE simulation to the selected initial configuration. Then, the mechanical properties of these models were studied through uniaxial compression FE simulation and experiments. In the research scope of this paper, the results demonstrate that the lattice structure can get NPR through the two-step modeling method when the Maxwell’s number is less than or equal to zero. The specific strength of the NPR structure obtained through the two-step modeling method was at most 1.5 times higher than that of the traditional 3D star-shaped NPR structure. Due to the high designability and excellent mechanical properties of lattice structures, this work provides a novel method for the manufacture of NPR structures with high specific strength.
Synthesis of MgB2 films on Hastelloy-C276 tape with Al2O3/Y2O3/MgO/LaMnO3 buffer layers by magnetron sputtering in co-evaporation mode
Authors: Yanilkin I V , Gumarov A I , Rudnev I A , Fatikhova L R , Kiiamov A G , Denisov A E , Khokhorin S A , Tayurskii D A , Batulin R G
Published: July 2024

This study presents the initial results of developing a technology for synthesizing a flexible superconducting magnesium diboride composite on a Hastelloy®-C276TM substrate coated with Al2O3/Y2O3/MgO/LaMnO3 buffer layers. The superconducting composite was deposited by magnetron sputtering from two Mg and B targets, followed by vacuum annealing at various substrate temperatures ranging from 400 °C to 700 °C. The superconducting transition temperature T
c ≈ 22 K, with a transition width ΔT ≈ 1 K, and critical current J
c ≈ 500 kA cm−2 (T= 5 K, H = 2 T) and J
c ≈ 11 kA cm−2 (T = 15 K, H = 2 T) at the optimal annealing temperature of 400 °C.