bluuebunny/crossref_metadata_2025 huggingface dataset:
Kerr nonlinearity in TE/TM microring resonators on cubic silicon carbide-on-insulator platforms
Authors: Meng Debin , Li Liwei , Liao Bin-Kai , Yi Xiaoke
Published: December 2024

Kerr nonlinearity plays a pivotal role in nonlinear photonics. Recent advancement in wafer bonding techniques has led to the creation of a cubic silicon carbide-on-insulator (3C-SiCOI) platform with improved crystalline quality, offering exciting prospects for investigating the Kerr effect in 3C-SiC. In this paper, we demonstrate 3C-SiC's Kerr effects through design, fabrication, and experimental investigation. By using the cavity enhanced four-wave mixing based on microring resonator (MRRs) supporting transverse electric or magnetic (TE/TM) polarizations on the 3C-SiCOI platform, we experimentally retrieve the Kerr nonlinear index (n2) of 3C-SiC within diverse waveguide dimensions, revealing a value of 4.92 and 5.00 × 10−19 m2/W for TE and TM polarizations, respectively. We further confirm the thermal stability of the 3C-SiC in Kerr effects at elevated temperatures from 100 °C to 300 °C, showing negligible change of n2. Moreover, we demonstrated optical parametric oscillation (OPO) in the fabricated single mode MRR via a dual-pump configuration. With an input power of less than 50 mW, a distinct OPO spectrum covering the C band has been achieved. These results signify the emergence of 3C-SiCOI as a promising platform for Kerr applications.
Convergence of bi-spatial pullback random attractors and stochastic Liouville type equations for nonautonomous stochastic p-Laplacian lattice system
Authors: Wang Jintao , Peng Qinghai , Li Chunqiu
Published: December 2024

We consider convergence properties of the long-term behaviors with respect to the coefficient of the stochastic term for a nonautonomous stochastic p-Laplacian lattice equation with multiplicative noise. First, the upper semi-continuity of pullback random (ℓ2, ℓq)-attractor is proved for each q ∈ [1, +∞). Then, a convergence result of the time-dependent invariant sample Borel probability measures is obtained in ℓ2. Next, we show that the invariant sample measures satisfy a stochastic Liouville type equation and a termwise convergence of the stochastic Liouville type equations is verified. Furthermore, each family of the invariant sample measures is turned out to be a sample statistical solution, which hence also fulfills a convergence consequence.
Identifying the onset and decay of quasi-stationary families of almost-invariant sets with an application to atmospheric blocking events
Authors: Badza Aleksandar , Froyland Gary
Published: December 2024

Macroscopic features of dynamical systems such as almost-invariant sets and coherent sets provide crucial high-level information on how the dynamics organizes phase space. We introduce a method to identify time-parameterized families of almost-invariant sets in time-dependent dynamical systems, as well as the families’ emergence and disappearance. In contrast to coherent sets, which may freely move about in phase space over time, our technique focuses on families of metastable sets that are quasi-stationary in space. Our straightforward approach extends successful transfer operator methods for almost-invariant sets to time-dependent dynamics and utilizes the Ulam scheme for the generator of the transfer operator on a time-expanded domain. The new methodology is illustrated with an idealized fluid flow and with atmospheric velocity data. We identify atmospheric blocking events in the 2003 European heatwave and compare our technique to existing geophysical methods of blocking diagnosis.
Fundamental understanding of quantum confinement effect on gate oxide reliability for gate-all around field-effect transistor
Authors: Li Xufan , Huang Shijie , Wang Jiawei , Wang Lingfei , Li Ling
Published: December 2024

Gate oxide reliability has become a significant concern for emerging technology nodes, particularly as transistors continue to scale down. Quantum confinement effects in nano-scaled devices complicate the trapping dynamics near the interface. Although these behaviors can be modeled using density-functional theory (DFT) and Marcus theory, a more efficient method is essential for characterizing critical reliability issues at the nano-device level. This paper presents a pioneering numerical study that employs a Bohm potential and Marcus theory, examining carrier concentration decay near the channel/oxide interface to evaluate the charge-trapping process using density-gradient coupled Poisson equations. This approach incorporates vital quantum corrections to classical studies. Key physics-based parameters are initially derived from DFT calculations and subsequently calibrated against experimental data. Our findings indicate that charge trap rates decrease with carrier density at the interface, ultimately affecting the device's threshold voltage shift.
Shrimp structure as a test bed for ordinal pattern measures
Authors: Zou Yong , Marwan Norbert , Han Xiujing , Donner Reik V. , Kurths Jürgen
Published: December 2024

Identifying complex periodic windows surrounded by chaos in the two or higher dimensional parameter space of certain dynamical systems is a challenging task for time series analysis based on complex network approaches. This holds particularly true for the case of shrimp structures, where different bifurcations occur when crossing different domain boundaries. The corresponding dynamics often exhibit either period-doubling when crossing the inner boundaries or, respectively, intermittency for outer boundaries. Numerically characterizing especially the period-doubling route to chaos is difficult for most existing complex network based time series analysis approaches. Here, we propose to use ordinal pattern transition networks (OPTNs) to characterize shrimp structures, making use of the fact that the transition behavior between ordinal patterns encodes additional dynamical information that is not captured by traditional ordinal measures such as permutation entropy. In particular, we compare three measures based on ordinal patterns: traditional permutation entropy εO, average amplitude fluctuations of ordinal patterns ⟨σ⟩, and OPTN out-link transition entropy εE. Our results demonstrate that among those three measures, εE performs best in distinguishing chaotic from periodic time series in terms of classification accuracy. Therefore, we conclude that transition frequencies between ordinal patterns encoded in the OPTN link weights provide complementary perspectives going beyond traditional methods of ordinal time series analysis that are solely based on pattern occurrence frequencies.
Dephasing of ion beams as magnetic vortex acceleration regime transitions into a bubble-like field structure
Authors: Hakimi Sahel , Bulanov Stepan S. , Huebl Axel , Obst-Huebl Lieselotte , Nakamura Kei , Gonsalves Anthony , Schenkel Thomas , van Tilborg Jeroen , Vay Jean-Luc , Schroeder Carl B. , Esarey Eric , Geddes Cameron R.
Published: December 2024

The interaction of an ultra-intense laser pulse with a near critical density target results in the formation of a plasma channel, a strong azimuthal magnetic field and moving vortices. An application of this is the generation of energetic and collimated ion beams via magnetic vortex acceleration. The optimized regime of magnetic vortex acceleration is becoming experimentally accessible with new high intensity laser beamlines coming online and advances made in near critical density target fabrication. The robustness of the acceleration mechanism with realistic experimental conditions is examined with three-dimensional simulations. Of particular interest is the acceleration performance with different laser temporal contrast conditions, in some cases leading to pre-expanded target profiles prior to the arrival of the main pulse. Preplasma effects on the structure of the accelerating fields are explored, including a detailed analysis of the ion beam properties and the efficiency of the process. Improved scaling laws for the magnetic vortex acceleration mechanism, including the laser focal spot size effects, are presented.
The field emission characteristics under transient electric field
Authors: Wu Yue , Su Jian-cang , Shi Jia-ru , Qiu Xu-dong , Zhang Hao-ran , Li Rui , Zhao Liang , Cheng Jie , Yan Wen-long , Yu Bin-xiong
Published: December 2024

This article concentrates on the field emission (FE) characteristics under the pulsed transient electric field. Experimental measurements are carried out by applying direct current (DC) voltage, millisecond pulse voltage, and microsecond pulse voltage. Additionally, 304 stainless steel, oxygen-free copper and titanium electrodes are utilized to verify the consistency. Compared with the case under DC electric field, three distinctive FE characteristics are observed under pulsed transient electric field: the regular emission, the intense emission, and the annihilation phenomenon. First, the emission starting point implies one strong correlation with the second partial derivative of transient electric field strength with respect to time. Second, the emission current under pulsed electric field is much higher than that under the DC electric field. Moreover, the FE current is deeply associated with the gradient of the electric field during the rising front. Third, the FE current is extinguished though there is still high transient electric field. The mechanism of the three characteristics is still unclear and should be the subject of further investigation.
Comparative study on the energy decay patterns and vortex characteristics of submersible thrusters under different structural configurations
Authors: Zhang Erfeng , Pan Qiang , Tian Fei , Shen Xi , Zhang Desheng , Ning Yanqiang
Published: December 2024

Submersible thrusters (STs) are crucial for applications such as wastewater treatment, but their energy decay mechanisms and flow characteristics remain inadequately understood. This study compares the original ST, a shrouded ST (SGT), and a configuration with both guide vanes and a shroud (SGVT), focusing on energy decay, jet evolution, vortex dynamics, and entropy production. Numerical simulations are conducted using adaptive mesh refinement and delayed detached eddy simulation turbulence models to capture the complex flow structures. Findings indicate that ST undergoes rapid energy decay with pronounced jet energy fluctuations in the transition phase (z/D = 4–8), whereas SGT and SGVT models exhibit slower decay rates, delaying the half-power decay position by 71% and 157.2%, respectively. In the ST jet, vortex interactions, particularly between tip vortices (TVs) and hub vortices (HVs), lead to jet instability, turbulence, and increased entropy production. SGT mitigates centrifugal forces by suppressing tangential velocity, delaying jet instability to downstream regions (z/D = 7). SGVT, by breaking the spiral TV and trailing edge root vortices into smaller-scale vortex clusters and reducing tangential velocity at the blade root, suppresses both TV and HV-induced instability. As a result, the high-entropy production wake width in SGVT is only 50% of that in ST. Instability in the SGVT jet is primarily governed by Kelvin–Helmholtz (K-H) instabilities in the shear layer, which, though weak, support downstream jet propagation. The increased entropy production in SGVT at early stages (z/D = 2–4) is attributed to the formation of small-scale TV clusters.
Two-dimensional TTH-graphene: Structural, defective, and interfacial engineering on anode materials for potassium-ion batteries
Authors: Dai Ya-Qun , Wu Zhi-Hui , Ma Tian-Ci , Zheng Xiao-Hong , Ye Xiao-Juan , Lin He , Liu Chun-Sheng
Published: December 2024

Potassium-ion batteries (PIBs) demonstrate significant potential for future renewable energy storage systems, given the high natural richness and economic benefits of potassium resources. Nevertheless, the primary challenge hindering the development of PIBs is the scarcity of appropriate anode materials capable of delivering high performance. Using first-principles calculations, we theoretically design a two-dimensional graphene allotrope, termed TTH-graphene, constructed from assembled tetracyclo[6.6.0.02,6.010,14]tetradeca-1(8),2,4,6,9,11,13-heptaene (C14H8) structural units, which demonstrates good dynamical, thermal, and mechanical stability. The non-hexagonal symmetry can enhance the surface reactivity, making TTH-graphene a high-performance anode for PIBs with a low K migration barrier (0.22 eV), a moderate average open-circuit voltage (0.42 V), a high theoretical capacity (956.33 mA h g−1), and a small lattice expansion (1.2%). Furthermore, the appearance of vacancy defects enhances the K adsorption strength but induces the decrease in ionic diffusivity. Compared with the monolayer, the TTH-graphene bilayer exhibits an enhancement of the adsorption and diffusion performance of K on the outer surface.
A numerical investigation of wake recovery for an H- and X-shaped vertical-axis wind turbine with wake control strategies
Authors: Giri Ajay Adhyanth , Simao Ferreira Carlos
Published: December 2024

Vertical-axis wind turbines (VAWTs), particularly in offshore wind farms, are gaining attention for their capacity to potentially enhance wake recovery and increase the power density of wind farms. Previous research on VAWT wake control strategies have demonstrated that the pitch offset is favorable for VAWT wake recovery. In the present study, an investigation on the wake recovery and its mechanisms for an H-Rotor and a novel X-Rotor VAWTs with fixed blade pitch offsets is conducted through qualitative and quantitative methods. The actuator line method is utilized in this study. Results indicate that the two rotors produce distinct vortex systems that drive the wake recovery process—which is augmented with pitch offsets. Through quantitative studies, the contribution of wake recovery due to advection increases dramatically with pitch offsets in the near wake. With pitch offsets, the inline available power increases up to 2.3 times for the rotors when compared to when there is no pitch offset. The mean kinetic energy flux occurs mostly above and below the rotors as well as the windward side, suggesting the mechanism of power replenishment for these rotors with pitch offsets. These results encourage further research into the effectiveness of wake recovery in the wind-farm level with the ground and atmospheric boundary layer influences.
A review of hydro-turbine unit rotor system dynamic behavior: Multi-field coupling of a three-dimensional model
Authors: Cao Jingwei , Luo Yongyao , Shi Yishu , Liu Xin , Xu Dexin , Wang Yanhu , Zhai Liming , Wang Zhengwei
Published: December 2024

The dynamic behavior of hydro-turbine rotor system is a complex multi-field and nonlinear problem, which has been studied by many researchers. The analysis of the rotor system dynamic characteristics is usually carried out based on the behavior analysis of bearings, hydraulics, electromagnetics, etc., while the thermo-elasto-hydrodynamic characteristics of bearings are extremely important to numerical accuracy. Therefore, this paper first summarizes the research progress in bearing lubrication performance, and further summarizes the research on hydro-turbine rotor system dynamic characteristics, including the modal characteristics and dynamic response characteristics. Finally, this paper summarizes the main research progress of the hydro-turbine rotor system and proposes possible directions in future research. Literature review shows that the hydro-turbine runners and bearings have achieved multi-field coupling analysis of three-dimensional (3D) models, and some work on multi-field coupling of rotor systems has been carried out. The transition of 3D multi-field coupling from single component to rotor system is significant to accurately predict the rotor system dynamic characteristics and the solution of engineering problems, which requires further in-depth research on the multi-field coupling theory, numerical methods, 3D model integrity, simulation software, etc., and the spatiotemporal synergy between multi-fields should be fully considered.
Impact of solar geoengineering on temperature-attributable mortality
Authors: Harding Anthony , Vecchi Gabriel A. , Yang Wenchang , Keith David W.
Published: December 2024

Decisions about solar geoengineering (SG) entail risk–risk tradeoffs between the direct risks of SG and SG’s ability to reduce climate risks. Quantitative comparisons between these risks are needed to inform public policy. We evaluate idealized SG’s effectiveness in reducing deaths from warming using two climate models and an econometric analysis of temperature-attributable mortality. We find SG’s impact on temperature-attributable mortality is uneven with decreases for hotter, poorer regions and increases in cooler, richer regions. Relative to no SG, global mortality is reduced by over 400,000 deaths annually [90% CI: (−1.2 million,2.7 million)] for cooling of 1 °C from 2.5 °C above preindustrial in 2080. We find no evidence that mortality reduction achieved by SG is smaller than the reduction from equivalent cooling by emissions reductions. Combining our estimates with existing estimates of sulphate aerosol injection direct mortality risk from air quality and UV-attributable cancer enables the first quantitative risk-risk comparison of SG. We estimate with 61% probability that the mortality benefits of cooling outweigh these direct SG risks. We find the benefits outweigh these risks by 13 times for our central estimates, or 4 deaths per 100,000 per 1 °C per year [90% CI: (−11,23)]. This is not a comprehensive evaluation of the risk–risk tradeoffs around SG, yet by comparing some of the most consequential impacts on human welfare it is a useful first step. While these findings are robust to a variety of alternative assumptions, considerable uncertainties remain and require further investigation.
Synthesis of evidence yields high social cost of carbon due to structural model variation and uncertainties
Authors: Moore Frances C. , Drupp Moritz A. , Rising James , Dietz Simon , Rudik Ivan , Wagner Gernot
Published: December 2024

Estimating the cost to society from a ton of CO
2
—termed the social cost of carbon (SCC)—requires connecting a model of the climate system with a representation of the economic and social effects of changes in climate, and the aggregation of diverse, uncertain impacts across both time and space. A growing literature has examined the effect of fundamental structural elements of the models supporting SCC calculations. This work has accumulated in a piecemeal fashion, leaving their relative importance unclear. Here, we perform a comprehensive synthesis of the evidence on the SCC, combining 1,823 estimates of the SCC from 147 studies with a survey of authors of these studies. The distribution of published 2020 SCC values is wide and substantially right-skewed, showing evidence of a heavy right tail (truncated mean of $132). ANOVA reveals important roles for the inclusion of persistent damages, the representation of the Earth system, and distributional weighting. However, our survey reveals that experts believe the literature underestimates the SCC due to an undersampling of model structures, incomplete characterization of damages, and high discount rates. To address this imbalance, we train a random forest model on variation in the literature and use it to generate a synthetic SCC distribution that more closely matches expert assessments of appropriate model structure and discounting. This synthetic distribution has a mean of $283 per ton CO
2
for a 2020 pulse year (5% to 95% range: $32 to $874), higher than most official government estimates, including a 2023 update from the U.S. EPA.
CXCL12 restricts tumor growth by suppressing the Ras, ERK1/2, c-Myc, and the immune checkpoint PD-L1 pathways
Authors: Kravtsova-Ivantsiv Yelena , Goldhirsh Gilad , Ciechanover Aaron
Published: December 2024

Cytokines constitute a family of proteins that modulate the immune system and are secreted by many cells. CXCL12, along with its receptor CXCR4, are essential players in numerous processes. Dysregulation of their function underlie the mechanism(s) of several pathologies, including malignancies. Here, we demonstrate an unexpected effect of the cytokine and its receptor: In both cells and animal models, CXCL12 restricts tumorigenicity of the human glioblastoma cells U87-MG and U-118, and of a cell line derived from PyMT mouse breast cancer. Overexpression of CXCL12 inhibits activation of the oncogene Ras which results in downregulation of its proliferative signals, such as reduced phosphorylation of the extracellular signal-regulated kinase 1/2 (ERK1/2), inhibition of c-Myc expression, and subsequent inhibition of cell cycle. Furthermore, CXCL12 induces downregulation of the growth differentiation factor 15 (GDF15), insulin-like growth factor-binding protein 6 (IGFBP6), and matrix metalloproteinase-3 (MMP3), which are implicated in sending metastases. Indeed, monitoring cell migration in vitro and generation of metastases in mice demonstrate that CXCL12 slows the migration of U87-MG and PyMT cells. Remarkably, overexpression of CXCL12 also downregulates the cell surface immune checkpoint protein programmed cell death-ligand 1 (PD-L1), resulting in recruitment of cytotoxic CD8 T cells into xenografts accompanied by their shrinkage. Overall, CXCL12 inhibits tumor growth through several distinct mechanisms: inhibition of cell cycle and migration, as well as impairment of immune checkpoint, thereby stimulating a strong host’s immune response. The mechanism(s) that renders CXCL12 a tumor-promoting factor in certain cells and a suppressor in others has remained elusive.
Exploring Sherry Simon’s views on translation through a postmodern lens
Authors: Parham Fatemeh
Published: December 2024

The present study takes a postmodern approach to Sherry Simon’s views on translation, aiming to uncover the extent
to which her ideas in translation studies align with postmodern thought. To this end, the works of prominent postmodern thinkers
including Lyotard, Baudrillard, Derrida, Cixous, Deleuze, Guattari, and Irigaray are examined. Their postmodern claims are listed
and described as scenarios. Then, Simon’s views are compared with these scenarios in quest of commonalities. The results indicate
that Simon’s views on gender are indeed postmodern. Her rejection of the conventional definition of fidelity reflects a postmodern
stance as it rejects rigid binary opposites. Similarly, her rejection of hierarchical structures aligns with postmodern
principles. Furthermore, her advocacy for dismantling absolutes in polarity can also be considered postmodern. Finally, her view
on handling texts in translation to foreground female subjectivity qualifies as a postmodern approach.
Renovation and revision
Authors: Qin Kaiyu , Li Xin
Published: December 2024

The new millennium has witnessed a widening application of Actor-Network Theory (ANT) to the field of Translation
Studies, but the interface of ANT and Museum Translation Studies has so far remained underexplored. This article focuses on the
Shanghai Jewish Refugees Museum as a case study. It attempts to construct the translation-related actor network involved in the
renovation of the museum in 2015 and the subsequent two rounds of revisions the bilingual guide scripts have undergone. It also
explores the bi-directional agential relations enabling the role change of main actors and the general development of the network.
This article argues that translation-related ANT analysis should deem translational relations as neither the center nor the end of
an actor network, and highlights the significance of nonhuman and non-translational actors in explaining the process of
translation production and revision in the context of Museum Studies.
Perceived barriers and enablers middle-aged and older adults experience to adopting ‘sustainable’ diets: A mixed methods systematic review
Authors: Copp Asha , Fu Danxin , Xiao Weiqi , Allman-Farinelli Margaret
Published: December 2024

The adoption of sustainable diets among middle-aged and older adults may lead to both improved health outcomes and lower environmental impact. Understanding the barriers and enablers that influence food choices and dietary patterns in this growing demographic is pivotal to inform the promotion of dietary change. A convergent integrated mixed methods systematic review was conducted using the Joanna Briggs Institute methodology. Four databases (MEDLINE, CINAHL, Scopus and PsychInfo) were searched for studies published from January 2009 to February 2024 that identified the perceptions of participants 45 years and older in high-income countries about sustainable food choices and barriers and enablers to consumption. From 6295 studies, 23 studies were included and critically appraised using the Mixed Methods Appraisal Tool. Findings were integrated in a narrative review. Key enablers included the following: understanding of environmental impacts of food; nutritional benefits of plant products; nutrition knowledge and awareness of the health and environmental concerns around some animal food sources. Key barriers included the following: cost of eating a sustainable diet; preference for taste of animal foods like meat and high accessibility; inconvenience of preparation; concerns around nutritional adequacy of plant foods versus animal foods; sociocultural influences and lack of familiarity about sustainability and diet. These findings provide insight into public perceptions of over 45 year olds and may be used by public health practitioners in education and nutrition promotion efforts to motivate people to overcome barriers, such as lack of knowledge, accessibility and food preparation skills as highlighted by this review. Other forms of research into policy and regulatory functions may be needed to further inform strategies to modify dietary patterns.
Perturbative ensemble density functional theory applied to charge transfer excitations
Authors: Amoyal Gil S , Kronik Leeor , Gould Tim
Published: December 2024

Charge transfer (CT) excitation energies are known to be challenging for standard time-dependent (TD) density functional theory (DFT) calculations. Perturbative ensemble DFT (pEDFT) was suggested as an easy-to-implelemt, low-cost alternative to TDDFT, because it is an in principle exact theory for calculating excitation energies that produces useful valence excitation energies. Here, we examine analytically and numerically (based on the benzene-tetracyanoethylene complex) how well pEDFT performs in the CT limit. We find that pEDFT is qualitatively correct in that it follows the Mulliken limit while being only weakly dependent on the underlying density functional approximation. We observe, however, that quantitatively pEDFT is not as accurate as TDDFT. We attribute this to the emergence of a new type of self-interaction-like term that adversely affects the computation.
A method for detecting small target weld defects based on feature reorganization network
Authors: Yu Xiaoxia , Zhang Yu , Zhou Kangqu
Published: December 2024

Weld defect detection is crucial for ensuring product reliability and safety in industrial manufacturing. Timely detection of small-target weld defects helps identify potential weld quality issues, minimizing losses and risks in the welding process. Existing methods simply concatenate feature segments during the upsampling process without analyzing the importance of each feature segment, leaving room for further improvement in detection accuracy. To address these issues, this study proposes a feature reorganization network for detecting small target weld defects. First, the C2f-Faster-efficient multi-scale attention feature extraction module and ghost-shuffle convolution are designed, and the large selective kernel network is introduced to dynamically adjust the receptive field of the backbone in the Backbone section, enhancing the model’s ability to extract small target features. Then, a lightweight Content-Aware ReAssembly of FEatures upsampling module is designed in the neck network, which retains more detailed information through feature reorganization and feature expansion, and introduces the parameter-free attention mechanism simple parameter-free attention module to fully capture the contextual information of small targets, thereby enhancing the proposed model’s ability to extract small target features. Finally, the generalized intersection over union boundary loss function is used to improve the network’s bounding box regression performance, achieving intelligent detection of small target weld defects. Experimental results show that the proposed method achieves a mean average precision, parameter count, and computation volume of 85.6%, 2.5 M, and 7.0 G, respectively, for weld defect detection, outperforming the comparison models and meeting the requirements of practical engineering applications.
Advanced hybrid algorithm for estimation of circularity deviation in coordinate metrology
Authors: Gsim Jamal , Jalid Abdelilah , Es-Sadek Mohamed Zeriab
Published: December 2024

In the field of precision mechanics such as automobiles or aeronautics, the estimation of defects in the shape of mechanical parts is a very common task, and the declaration of conformity is mainly based on the precision of this value. This research introduces an innovative hybrid optimization methodology that enhances the precision of estimation of circularity defects. The method proposed combines the genetic algorithm (GA) and the interior point method (IPM), this approach overcomes the limitations of traditional methods like least squares and orthogonal distance regression, which rely on initial estimates parameters to ensure convergence. The GA-IPM hybrid eliminates the need for such initial guesses, leading to faster convergence and more accurate results. To control a mechanical part, a cloud of points is preleved by using a coordinate measuring machines, after treatment of those datasets the estimation of circularity defects is calculated using the proposed algorithm GA-IPM. To validate our approach a comparative study is carried out according to the standard ISO 10 360–6, which consists of comparing the results (substitute geometry parameters) obtained with those of National Institute of Standards and Technology considered as reference values. Several examples have been processed, circle totally or partially measured in order to verify the robustness of the algorithm in terms of convergence and calculation precision, the circularity defect is subsequently calculated on the basis of these parameters. The comparison shows that our method estimates the parameters and the circularity defect well without needing a vector of initial estimates parameters. Given the results obtained, this hybrid approach represents a contribution to the estimation of the circularity deviation, thus offering industries a reliable, precise method to ensure the declaration of conformity of mechanical parts.
Path planning for flexible needle based on both insertion mechanism kinematics and needle bending model
Authors: Zhao Yan-Jiang , Zhang He , Du Hai-Yan , Qian Cheng , Jin Ye-Xin , Chen Yin , Yang Guang-Zhe
Published: December 2024

Objective. Due to the limited operating space in the magnetic resonance (MR) environment, there is coupled motion in the insertion mechanism, which not only reduces the flexibility of the robot but also challenges the insertion path planning. Meanwhile, the path planning is also restricted by the bending rule of the flexible needle, thus the bending model of the needle is also essentially built. Approach. This paper proposes a path planner for the flexible needle based on both the coupled motion kinematics of the insertion robot and the bending model of the flexible needle. A kinematic analysis for the coupled motion of insertion robot is performed. And the bending model of flexible needle is established based on the needle-tissue interactions. The position and posture of the needle insertion at the entry point are obtained by the calculation of the target position and the analysis of the bending model. And the rotation or translation coordinates of each robot joint are calculated by the inverse kinematics of the insertion robot. Then the path planning based on the coupled kinematics and the bending model is realized. Main results. The insertion experiments were performed for each target of G
1 and G
2. The root mean square errors were 0.83 mm and 0.74 mm, and the maximum errors were 1.1 mm and 0.9 mm for G
1 and G
2, respectively. The experimental results show that the effectiveness and accuracy of the path planning can meet the requirements for a general minimally invasive surgery (MIS), so the proposed path planning algorithm is feasible. Significance. This study provides a new solution for the path planning of insertion robots for the MIS. This method can meet the insertion mechanism working within the limited operating space in the MR environment and has a high application value in future clinical medicine.
Properties and applications of the Kirkwood–Dirac distribution
Authors: Arvidsson-Shukur David R M , Braasch Jr William F , De Bièvre Stephan , Dressel Justin , Jordan Andrew N , Langrenez Christopher , Lostaglio Matteo , Lundeen Jeff S , Halpern Nicole Yunger
Published: December 2024

There are several mathematical formulations of quantum mechanics. The Schrödinger picture expresses quantum states in terms of wavefunctions over, e.g. position or momentum. Alternatively, phase-space formulations represent states with quasi-probability distributions over, e.g. position and momentum. A quasi-probability distribution resembles a probability distribution but may have negative and non-real entries. The most famous quasi-probability distribution, the Wigner function, has played a pivotal role in the development of a continuous-variable quantum theory that has clear analogues of position and momentum. However, the Wigner function is ill-suited for much modern quantum-information research, which is focused on finite-dimensional systems and general observables. Instead, recent years have seen the Kirkwood–Dirac (KD) distribution come to the forefront as a powerful quasi-probability distribution for analysing quantum mechanics. The KD distribution allows tools from statistics and probability theory to be applied to problems in quantum-information processing. A notable difference to the Wigner function is that the KD distribution can represent a quantum state in terms of arbitrary observables. This paper reviews the KD distribution, in three parts. First, we present definitions and basic properties of the KD distribution and its generalisations. Second, we summarise the KD distribution’s extensive usage in the study or development of measurement disturbance; quantum metrology; weak values; direct measurements of quantum states; quantum thermodynamics; quantum scrambling and out-of-time-ordered correlators; and the foundations of quantum mechanics, including Leggett–Garg inequalities, the consistent-histories interpretation and contextuality. We emphasise connections between operational quantum advantages and negative or non-real KD quasi-probabilities. Third, we delve into the KD distribution’s mathematical structure. We summarise the current knowledge regarding the geometry of KD-positive states (the states for which the KD distribution is a classical probability distribution), describe how to witness and quantify KD non-positivity, and outline relationships between KD non-positivity, coherence and observables’ incompatibility.
The analysis of carrier transport mechanism at the interface of BZOPET-GR Schottky contact
Authors: Zhang Jianhua , Li Yapeng , Jia Jiqiang , Luo Zhaoyu
Published: December 2024

Through the hydrothermal technique, we successfully deposited boron (B)-doped zinc oxide nanorods (ZnO NRs) onto a polyethylene terephthalate (PET)/graphene (GR) flexible substrate, creating a B-ZnO/PET/GR Schottky contact. The ZnO NRs exhibited a well-defined hexagonal structure with a lattice constant size of approximately 0.502 nm, as evidenced by characterization results. X-ray Photoelectron Spectroscopy (XPS) analysis revealed a reduction in oxygen vacancies with increasing B ion doping. The current–voltage (I-V) characteristics of the Schottky contacts were systematically investigated over a temperature range of 160–300 K. As the temperature increased, the barrier height exhibited an upward trend, while the ideality factor decreased. This behavior was ascribed to barrier inhomogeneity at the Schottky contact interface. Employing a single Gauss distribution function for barrier height, we verified and elucidated this phenomenon, contributing to a comprehensive understanding of the observed temperature-dependent electrical properties.
Functional dependency and cardiometabolic multimorbidity in older people: pooled analysis of individual-level data from 20 countries
Authors: Bai Anying , Chen Qiushi , Geldsetzer Pascal , Gray Muir , Xie Zhilan , Zhang Daqian , Baernighausen Till , Hu Yixin , Jiang Yu , Chen Simiao
Published: December 2024

Background

The impact of cardiometabolic multimorbidity (CMM) on functional dependency (FD) is well established, but the temporal effect of FD on CMM and its mechanisms remain underexplored.

Design

A multicohort study pooled data from three international cohorts.

Setting

Data were sourced from the Health and Retirement Study (USA), the China Health and Retirement Longitudinal Study (China) and the Survey of Health, Ageing and Retirement in 18 European countries.

Methods

FD was defined as the inability to perform basic activities of daily living (ADLs) and instrumental ADLs (IADLs) independently. CMM was defined as the co-occurrence of two or three cardiometabolic diseases, including diabetes, heart disease and stroke. Generalised estimating equation models assessed associations between FD and CMM, with mediation analysis using the Karlson, Holm and Breen method to explore the effects of hypertension and depressive symptoms. Sensitivity analyses ensured robustness.

Results

The final cohort included 157 512 and 190 249 individuals for ADL and IADL analyses, respectively. CMM prevalence was 18.97% and 16.65% in these groups. FD was consistently associated with higher CMM risk, with odds ratios ranging from 1.47 (95% confidence interval: 1.33–1.63) to 1.56 (1.42–1.73). Hypertension and depressive symptoms increased CMM risk, particularly at higher FD levels. Mediation analysis showed hypertension and depressive symptoms accounted for 8.01%–16.43% and 12.04%–18.36% of the adverse effect of FD on CMM, respectively, with more pronounced effects among smokers and heavy drinkers.

Conclusions

Targeted interventions focusing on hypertension, mental wellness, lifestyle factors, and integrated treatments for FD are crucial to prevent CMM in older adults.
Differences in mean age at diagnosis of invasive melanoma for men and women, by anatomic site, thickness, and subtype
Authors: Whiteman David C , Pandeya Nirmala , Olsen Catherine M
Published: December 2024

Background

Understanding the factors influencing age at melanoma diagnosis by sex and anatomic site is crucial for developing effective prevention and early detection strategies. While previous research has highlighted sex-based differences in melanoma incidence by age and anatomic distribution, the underlying mechanisms remain unclear. We aimed to investigate sex-specific patterns in melanoma age at diagnosis across different anatomic sites and thickness categories, considering the potential influence of disease progression and detection rates.

Methods

We conducted a registry-based study to examine mean age at diagnosis of invasive melanoma over two decades for men and women in the US (limited to white race), and Queensland, Australia. Mean age at diagnosis was calculated for men and women according to anatomic site (head/neck, trunk, upper limb, lower limb), and further by Breslow thickness (<1.00 mm, 1.01-2.00 mm, 2.01-4.00 mm, >4.00 mm) and histologic subtype (superficial spreading, nodular, lentigo maligna, ‘other’ subtypes, and subtype ‘not otherwise specified’). Case-listings of all invasive melanoma diagnoses between 1 January 1999 and 31 December 2018 were obtained from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program (9 registries) and from the Queensland Cancer Registry. Sensitivity analyses were performed restricting the data to the most recent 5-year time period (2014-2018). All analyses were conducted between 15 July and 19 August 2024.

Results

On average, women were diagnosed with invasive melanoma 3-8 years younger than men. The sex-difference in mean age at diagnosis was observed at all body sites and across most thickness categories in the US White and Queensland populations, but was most marked for thinner melanomas (<1.00 mm) and melanoma of the trunk. Women were significantly younger than men at diagnosis of superficial spreading and nodular melanoma at all body sites in both populations, even within 0.1mm thickness strata.

Conclusions

Sex may be a factor that influences melanocytic progression. The consistently younger age of melanoma diagnosis in women compared with men suggests a need for tailored approaches to melanoma control.
Sofosbuvir/Velpatasvir Pharmacokinetics, Safety, and Efficacy in Pregnant People With Hepatitis C Virus
Authors: Chappell Catherine A , Kiser Jennifer J , Brooks Kristina M , Randolph Riley , Macio Ingrid S , Meyn Leslie A , MaWhinney Sam , Rick Anne-Marie , Muniz Gysella B , Kwon Kyung min , Letterio Cathleen , Naik Sarjita , Kreter Bruce , Bunge Katherine E , Krans Elizabeth E , Hillier Sharon L
Published: December 2024

Background

Treatment of hepatitis C virus (HCV) during pregnancy can cure maternal HCV and prevent perinatal HCV transmission. The primary objective was to compare the pharmacokinetics (PK) of sofosbuvir (SOF)/velpatasvir (VEL) in pregnant versus nonpregnant people.

Methods

Pregnant people with chronic HCV infection were enrolled between 23 and 25 weeks’ gestation and were provided SOF/VEL daily for 12 weeks. PK visits were performed at 3, 6, and 9 weeks. VEL, SOF, and GS-331007 (the inactive metabolite of SOF) in plasma and the SOF active metabolite (007-TP) in peripheral blood mononuclear cells (PBMCs) and dried blood spots (DBSs) were measured and compared to historical data in nonpregnant people. Maternal adverse events, delivery outcomes, the sustained virologic response 12 weeks after therapy, infant adverse events, and HCV perinatal transmission were assessed.

Results

Fourteen participants were screened, and 11 enrolled. One participant discontinued treatment due to worsening of hyperemesis. VEL area under the curve (AUC) was similar to historic data in nonpregnant people, but the AUCs of SOF and GS-331007 were 38% higher and 38% lower, respectively. Concentrations of 007-TP in PBMCs were comparable or higher, whereas 007-TP in DBSs was approximately 50% lower in pregnant versus nonpregnant people. All 10 participants who completed treatment had undetectable HCV RNA at delivery. Two participants were lost to follow-up after delivery, but 1 had an HCV RNA through clinical care. All participants with data were cured (n = 9) and none of the infants acquired HCV (n = 8).

Conclusions

SOF/VEL exposures were not clinically different in pregnancy and support further evaluation of antenatal SOF/VEL treatment.
Associations of sarcopenia and malnutrition with 30-day in-hospital morbidity and mortality after cardiac surgery
Authors: Abe Takahiro , Inao Tasuku , Shingu Yasushige , Yamada Akira , Takada Shingo , Fukushima Arata , Oyama-Manabe Noriko , Yokota Isao , Wakasa Satoru , Kinugawa Shintaro , Yokota Takashi
Published: December 2024

OBJECTIVES

Sarcopenia and malnutrition often occur simultaneously in adults with cardiovascular diseases. Our objective was to determine the associations of preoperative sarcopenia and malnutrition with major adverse cardiac and cerebral events (MACCE) after cardiac surgery

METHODS

We retrospectively analysed 154 consecutive patients who underwent elective cardiac surgery between January 2015 and June 2018 at two institutions in Japan. Sarcopenia and nutritional status were preoperatively assessed by bilateral psoas muscle volume index (PMVI) using CT scans and the prognostic nutritional index (PNI), respectively.

RESULTS

The median age in the total cohort was 69 years, and 43% were women. Within 30 days after surgery, 20 patients developed in-hospital MACCE and seven patients died of any cause. Low PMVI (<72.25 cm3/m2) and low PNI (<48.15) were each independent predictors of postoperative MACCE occurrence with odds ratios (95% confidence interval) of 3.58 (1.22–10.53) and 3.73 (1.25–11.09) when adjusted for age and sex, and 3.25 (1.07–9.87) and 3.27 (1.08–9.89) when adjusted for preoperative left ventricular ejection fraction, angiotensin-converting enzyme inhibitor or angiotensin-receptor blocker, and anticoagulant. In addition, the combination of low PMVI and low PNI conferred the highest risk of in-hospital MACCE among the four groups (i.e. the low PMVI, low PNI, low PMVI + low PNI and neither low PMVI nor low PNI groups).

CONCLUSIONS

Preoperative low PMVI and low PNI were respectively associated with 30-day in-hospital MACCE occurrence after cardiac surgery. Notably, coexistence of these reductions further enhanced the risk of postoperative MACCE.
A zero-inflated hidden semi-Markov model with covariate-dependent sojourn parameters for analysing marine data in the Venice lagoon
Authors: Ricciotti Lorena , Picone Marco , Pollice Alessio , Maruotti Antonello
Published: December 2024

This paper introduces a concomitant-variable hidden semi-Markov model tailored to analyse marine count data in the Venice lagoon. Our model targets acqua alta events, i.e. the exceedances of flooding limits, addressing the prevalent zero counts within the dataset through a fitted zero-inflated Poisson distribution. The data’s dynamics are attributed to a discrete set of hidden environmental risk states, evolving through time following a (nonhomogeneous) hidden semi-Markov chain. Furthermore, we extend the conventional hidden semi-Markov approach by introducing regression-dependent state-specific duration parameters, enhancing the model’s adaptability and precision in capturing real-world complexities. Our methodology hinges on the maximum-likelihood estimation, directly optimizing the log-likelihood function to infer the model’s parameters. Through the definition of this novel hidden semi-Markov model, we aim to offer a complete understanding of the intricate interplay between weather states, environmental variables, and the observed marine count data, thus contributing to a nuanced analysis of the Venice lagoon’s data.
Fast spatial simulation of extreme high-resolution radar precipitation data using integrated nested Laplace approximations
Authors: Vandeskog Silius M , Huser Raphaël , Bruland Oddbjørn , Martino Sara
Published: December 2024

Aiming to deliver improved precipitation simulations for hydrological impact assessment studies, we develop a methodology for modelling and simulating high-dimensional spatial precipitation extremes, focusing on both their marginal distributions and tail dependence structures. Tail dependence is crucial for assessing the consequences of extreme precipitation events, yet most stochastic weather generators do not attempt to capture this property. The spatial distribution of precipitation occurrences is modelled with four competing models, while the spatial distribution of nonzero extreme precipitation intensities are modelled with a latent Gaussian version of the spatial conditional extremes model. Nonzero precipitation marginal distributions are modelled using latent Gaussian models with gamma and generalized Pareto likelihoods. Fast inference is achieved using integrated nested Laplace approximations. We model and simulate spatial precipitation extremes in Central Norway, using 13 years of hourly radar data with a spatial resolution of 1×1km2, over an area of size 6,461km2, to describe the behaviour of extreme precipitation over a small drainage area. Inference on this high-dimensional data set is achieved within hours, and the simulations capture the main trends of the observed precipitation well.