bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Enhanced Recovery after Surgery in Morbidly Obese Patients Undergoing Free Flap Breast Reconstruction
Authors: Stephens Kristen L. , DeVito Robert G. , Hollenbeck Scott T. , Campbell Chris A. , Stranix John T.
Published: December 2024

Background Enhanced recovery after surgery (ERAS) pathways have been widely implemented across many surgical practices, including autologous breast reconstruction. However, the benefits of ERAS in the morbidly obese population have yet to be defined.

Methods A retrospective chart review of patients undergoing deep inferior epigastric artery perforator (DIEP) flap breast reconstruction at our institution from 2017 to 2022 was performed. Length of stay (LOS), intensive care unit (ICU) utilization, opioid usage, cost, and flap outcomes were analyzed in patients with body mass index greater than 35 before and after ERAS implementation.

Results Thirty-five morbidly obese patients receiving DIEP flap breast reconstruction were identified before ERAS and 18 after ERAS. There were no differences in unilateral versus bilateral or immediate versus delayed reconstruction. LOS decreased with ERAS (3.43 vs. 2.06 days, p < 0.0000001). ICU utilization decreased with ERAS (0.94 vs. 0.0 days, p < 0.0001). Daily and total opioid usage decreased with ERAS (41.8 vs. 17.9 morphine milligram equivalent [MME], p < 0.0001; 190.5 vs. 54.7 MME, p < 0.0001). Financial metrics improved with ERAS, including decreased total cost ($33,454 vs. $25,079, p = 0.0002) and increased cost margin ($4,458 vs. −$8,306, p = 0.004). There were no differences in donor or recipient site outcomes including flap loss, deep venous thrombosis/pulmonary embolism, hernia/bulge, delayed wound healing, revisions, and blood loss.

Conclusion ERAS pathways maintain benefits in the morbidly obese population undergoing abdominally based autologous breast reconstruction, including decreased LOS, ICU utilization, opioid use, and cost while maintaining successful reconstruction outcomes.
Advancing Pediatric Robotic Colorectal Surgery: Trends, Outcomes, and Future Directions—A Comprehensive Review
Authors: Pini Prato Alessio , Lacher Martin
Published: December 2024

Introduction Pediatric robotic colorectal surgery has rapidly evolved, offering enhanced precision and safety for treating complex conditions such as Hirschsprung disease (HSCR), anorectal malformations (ARMs), and inflammatory bowel disease (IBD). This review analyzes recent trends, outcomes, and complications in robotic colorectal procedures for pediatric patients.

Materials and Methods A systematic review was performed using PubMed, yielding 1,112 articles related to pediatric robotic colorectal surgery. After applying exclusion criteria, 35 papers were analyzed, focusing on patient characteristics, procedure types, and clinical outcomes.

Results Since 2001, approximately 700 pediatric patients have undergone robotic colorectal procedures, with HSCR being the most commonly treated condition (n = 421). The review highlights that 1.7% of patients experienced Clavien–Dindo grade III complications, while 11.5% had grade I to II complications, indicating a favorable safety profile. The use of robotic platforms facilitated improved precision during perirectal dissection and reduced the risk of damage to adjacent structures, particularly in cases requiring complex pelvic dissections. Despite promising outcomes, the uptake of robotic colorectal surgery remains lower than that for urologic procedures due to challenges such as cost, instrument size, and specialized training.

Conclusion Robotic colorectal surgery in children is a safe and effective approach, particularly for complex conditions like HSCR, IBDs, and ARMs. While adoption is currently limited by cost and training requirements, ongoing advancements in technology and techniques promise to broaden its application and improve outcomes in pediatric surgery.
Advancements in mTOR Inhibitors for Non-Small-Cell Lung Cancer: Mechanisms, Efficacy, and Future Perspectives
Authors: Thaker Aanal , Patel Shrusti , Chaube Udit , Dey Rajdeep , Shaw Suman , Bhatt Hardik , Patel Bhumika
Published: December 2024

This account comprehensively reviews the recent advancements in the development of mechanistic target of rapamycin (mTOR) inhibitors targeting non-small-cell lung cancer (NSCLC), focusing on their mechanisms, efficacy, and clinical trial statuses. Key small molecules such as RM-018 and RMC-4998 highlight novel approaches in targeting the KRASG12C mutation, offering enhanced potency compared to earlier inhibitors. Traditional and plant-derived compounds, including Fuzi alkaloids, salvianolic acid, and ononin, demonstrate promising antitumor activities through diverse pathways, such as the PI3K/AKT/mTOR signaling axis. Combination therapies targeting dual pathways show synergistic effects, improving treatment efficacy. The role of personalized medicine, driven by genetic profiling and pathway-specific inhibitors, is emphasized as a transformative approach in NSCLC management. These findings highlight the potential of mTOR-targeting agents as a cornerstone in advancing NSCLC therapies.

1 Introduction

2 Small-Molecule mTOR Inhibitors

3 mTOR Inhibitors in Clinical Trials

4 Conclusion and Future Directions
Migration as good, bad and necessary: examining impacts of migration on staying Himalayan communities affected by climate change
Authors: Upadhyay Himani
Published: December 2024

Within the migration system, the seminal Foresight report highlighted that climate change can have significant implications for staying populations. Yet research on this remains limited. This study aims to fill this gap by assessing the impacts of sustained outmigration on staying farmer communities in the Indian Himalayan Region, affected by incremental climate change. Employing an empirical qualitative approach, new data is collected through semi-structured interviews (n = 72). Staying communities describe migration as good, bad, and necessary with the majority (46%) noting negative impacts such as fewer people to do agriculture, abandoned assets, more tasks for women, loss of community, disrupted household structures, mental health implications for the elderly, and disinvestment in public services. While remittances from migration have positive impacts, they are primarily used for meeting everyday needs (81%) and not invested in climate change adaptation. In addition to migration impacts, changing weather patterns, agricultural shifts, and societal transformations further exacerbate the vulnerabilities of staying populations. Without policy support to address these vulnerabilities, the benefits of migration may not effectively contribute to climate change adaptation. The findings here are likely applicable to staying populations in other mountain areas, facing similar pressures from migration and climate change, underscoring the need for targeted interventions to build long-term adaptive capacity.
Nonlinear characteristics of superconductor dynamics in an electromagnetic field of threshold frequency
Authors: Dolinskii Yu. L.
Published: December 2024

It is shown that, in the presence of a high-intensity electromagnetic field with threshold frequency s0≈2Δ, a superconductor can absorb electromagnetic waves of frequency s1 ⪡ Δ even when its temperature T = 0.
Superconductivity and the charge-ordered state in systems with localized pairing centers
Authors: Kulik I. O. , Pedan A. G.
Published: December 2024

The influence of pair correlations of electrons at neighboring sites on the superconducting transition and on the charge-ordered state in a system of electron pairs is investigated using the regular model of a superconducting glass. It is shown that for sufficiently strong repulsion, the transition temperature vanishes not only at points v = 0 and v = 1, but also at v = 1/2 (2v is the average number of electrons per site). The model of a superconducting glass is applied to alloys of some transition metals, which permits explaining the dependence of Tc on the effective valence of the alloy (Matthias’ rule).
Theory of heat transfer by vacancies
Authors: Strzhemechnyi M. A. , Kal'noi S. E.
Published: December 2024

Heat transport by vacancies in a solid is examined. A macroscopic kinetic equation, in which dislocations and the boundaries of the specimen appear as vacancy sources and sinks, and plasticity equations, which have to be solved jointly, are formulated. Boundary conditions for different cases are discussed. The solution of the kinetic equation for the case of a specimen with restricted boundaries, corresponding to constant-volume experiments, is analyzed in detail.
Experimental observation of librational heat transport
Authors: Kravchenko Yu. G. , Krupskii I. N.
Published: December 2024

We have studied the properties of heat transport in solid NH3 and NH3 at submelting temperatures. We have observed a contribution to the thermal conductivity of ND3 due to librational heat transport.
Negative magnetoresistance in graphite and its compounds with small concentrations of potassium impurities
Authors: Matsui L. Yu. , Khar'kov E. I.
Published: December 2024

The temperature and field dependences of the negative magnetoresistance in disordered graphites and their compounds with small concentrations of potassium impurities have been investigated in the temperature range from 4.2 to 300 °K and in magnetic fields of up to 60 kOe. The results obtained are compared with the theory that treats the quantum corrections to the conductivity in a magnetic field as being due to the effects of electron localization and the interference of the electron-electron and electron-impurity scatterings.
The nematic–smectic A phase transition
Authors: Kats E. Ts.
Published: December 2024

The nematic–smectic A phase transition is investigated. The interaction of fluctuations and anharmonicities is taken into account. The role of gauge invariance is discussed.
Charge-density waves in disordered systems
Authors: Vinokur V. M. , Feigeľman M. V.
Published: December 2024

The dielectric permeability χ of a one-dimensional charge-density wave, interacting with a lattice and with electron-scattering impurities, has been found as a function of the incommensurability parameter h in the case of various types and degrees of disorder. It has been shown that in the case of strong disorder the permeability is constant if “backward” scattering predominates in the system. If “forward” scattering predominates in the system, χ ∼h4/3 for large values of h. In the case of weak disorder, χ is constant in the commensurate phase and grows ((h – hc)/hc)1/3ln−4/3(hc/(h – hc)) (where hc is the threshold value of the incommensurability vector) in the region h–hc≪h0, i.e., in the weakly incommensurate region in which a well defined soliton lattice exists. With a further increase in h,χ∼(a+hc2/h2)−2/3, where a is the ratio of the intensities of the random potentials responsible for the “backward” and “forward” scattering. The low-frequency characteristics of the density of states ρ(ω) and the conductivity σ(ω) have been calculated.

The shape of the σ(ω) peak at a frequency of the order of the pinning frequency in the case of weak disorder is described. It is shown that in the case of strong disorder the low-frequency asymptotic form of the conductivity is decribed by the Mott–Berezinskii formula.
Influence of dislocations in a soliton lattice on the commensurate–incommensurate transition
Authors: Bor T. , Pokrovskii A. L. , Talapov A. L.
Published: December 2024

We consider a two-dimensional incommensurate system of atoms adsorbed on the surface of a crystal. Fluctuational creation of soliton lines is possible in such a system. It is shown that this effect leads to a change in the behavior of the free energy in the vicinity of the transition point. Introducing the transition matrix and fermion variables, we find the dependence of the concentrations of atoms on the surface on the chemical potential. An analogy with a phase transition in the Ising model is traced.
Influence of long-range effects on the transverse localization of electrons above a helium film
Authors: Monarkha Yu. P.
Published: December 2024

The behavior of an external electron above a dipolarly electrified helium film is theoretically investigated. It is shown that, even when the polarization effects are neglected, an infinite plane of dipoles attracts an external electron if the negative charges are closer to the electron than the positive ones. It is concluded that the concentration of surface electrons above a helium film covering a metallic plate can attain a critical (maximum) value even in the case of zero potential of the plate. It is also shown that, under realistic experimental conditions, because of the long-range nature of the interaction potentials, the transverse localization of an electron above a helium film covering a solid substrate is to a large extent due to the image forces exerted on the electron by all the neighboring electrons. The effective clamping field acting on the individual electrons is computed.
Band structure, Fermi surface, and optical properties of hexagonal yttrium
Authors: Kulikov N. I. , Kulatov É. T.
Published: December 2024

The band structure of hcp yttrium is calculated using a linearized hybridized Korringa-Kohn-Rostoker method. The crystal potential was made self-consistent within the framework of a local approximation of the density-functional formalism (Hedin-Lundqvist potential). The density of states, the optical density of states, and the cross sections of the Fermi surface are calculated and compared with the results of corresponding experiments. The agreement between the calculation and measurements is satisfactory. The calculated results are used to interpret the results of optical experiments and also to explain the lack of superconductivity and magnetic order in this metal.
Anomalous orientational transition in disordered weak ferrimagnets
Authors: Sinitsyn E. V. , Bostrem I. G.
Published: December 2024

We demonstrate the possibility of an orientational transition induced by an external field imposed along the weak magnetic moment in noncollinear antiferromagnets with fluctuations in the Dzyaloshinskii interaction. The magnetization curve of a system in which such a transition is observed is similar to the magnetization curve for a two-sublattice ferrimagnet.
Resonance effects in a Wigner crystal above a periodic relief
Authors: Shevchenko S. I.
Published: December 2024

We examine the behavior of a Wigner crystal in a helium film covering a solid substrate containing a periodic relief. When there is a strong electric field parallel to the substrate, the velocity of the crystal has an oscillatory component in addition to its constant component. Resonance energy absorption is observed when the crystal is illuminated with a frequency which corresponds to the crystal oscillatory frequency. We find the frequency and amplitude of the absorbed power as functions of the system parameters.
Effect of a magnetic field on the excess resistance of SNS sandwiches
Authors: Logvenov G. Yu. , Ryazanov V. V.
Published: December 2024

The contribution of superconducting plates to the resistance of Ta–Cu–Ta sandwiches in the presence of a magnetic field of up to 170 Ge is investigated. Near the superconducting transition temperature TcH, the Ta used was in a mixed (vortical) state. It is shown that the presence of gradients of the order parameter near the Abrikosov vortices appreciably changes the penetration depth of a longitudinal electric field into the superconductor and leads to a corresponding change in the excess resistance of SNS sandwiches.
Investigation of the uhf properties of arrays of Josephson bridges
Authors: Amatuni L. É. , Gubankov V. N. , Ovsyannikov G. A.
Published: December 2024

The results of an experimental investigation of the electrophysical and uhf properties of arrays of two sequentially connected Josephson bridges with variable thickness (BVT) consisting of tin are presented. It is shown that the uhf properties of the chains with large distances between BVT (exceeding the penetration depth of the constant electric field into the superconductor lE) are determined by the synchronization of the Josephson oscillations of separate bridges by the external uhf signal. The conditions for and characteristics of such “external” synchronization of Josephson oscillations in the array are clarified.
Jet reaction and thermal counter-flow in helium II
Authors: Gamtsemlidze G. A. , Kiknadze L. V. , Mamaladze Yu. G. , Mirzoeva M. I.
Published: December 2024

The thermal counter-flow of the components of He II in the subcritical and supercritical regimes is investigated experimentally and theoretically. The temperature dependences of the reaction force, acting on the heat liberating surface, and of the critical flow (critical velocity), as well as the dependence of the reaction force on the intensity of heat liberation, are measured. The difference between the temperature dependences obtained in the experiments of Kapitsa and Strelkov and in this work, on the one hand, and in Hall’s experiment, on the other, is explained. It is demonstrated that in the supercritical regime, vortex formation decreases the reaction force, since the momenta and velocities of the vortices are oriented in opposite directions.
Detection of exciton luminescence from high-energy states in xenon cryocrystals
Authors: Belov A. G. , Svishchev V. N. , Fugoľ I. Ya. , Yurtaeva E. M.
Published: December 2024

We have investigated the processes of the formation and radiative relaxation of highly excited states of xenon cryocrystals. The measurements were carried out by means of cathodoluminescence spectroscopy in the region of band-to-band transitions. In the energy range 1.5–5 eV we detected luminescence that is due to both trapped and free hole states with thermalized electrons. The recombination of free band carriers is shown to entail the formation of collective high-energy excitations that correspond to X-exciton states.
Ablation of aluminum with GHz bursts of temporally stitched laser filaments
Authors: Kerrigan Haley , Thome Owen , Richardson Martin
Published: December 2024

Ablation of aluminum by ultra-high repetition rate trains of ultrashort pulses is investigated using bursts of up to 32 150 fs pulses with sub-nanosecond inter-pulse delays generated by a custom titanium:sapphire-based laser architecture. Single-shot interactions of several burst configurations with up to ∼0.4 J of energy are investigated and compared to single femtosecond pulse interactions. White-light interferometry measurements of the ablated volume and images of the single-shot ablation craters are presented. These interactions are conducted in air with the pulses undergoing nonlinear filamentation. The ultrafast pulse trains employed in this investigation utilize repetition rates >1 GHz and uniquely propagate in the nonlinear regime with continuous plasma and precise coaxial overlap between pulses over extended ranges due to the “stitching” of consecutive pulses' filament plasmas, previously described by Reyes et al. [J. Opt. Soc. Am. B Opt. Phys. 36, G52 (2019)]. The large craters generated by a single filament burst provide a promising means for long-range stand-off ablation applications.
Design and performance of a magnetic bottle electron spectrometer for high-energy photoelectron spectroscopy
Authors: Borne Kurtis , O’Neal Jordan T. , Wang Jun , Isele Erik , Obaid Razib , Berrah Nora , Cheng Xinxin , Bucksbaum Philip H. , James Justin , Kamalov Andrei , Larsen Kirk A. , Li Xiang , Lin Ming-Fu , Liu Yusong , Marinelli Agostino , Summers Adam M. , Thierstein Emily , Wolf Thomas J. A. , Rolles Daniel , Walter Peter , Cryan James P. , Driver Taran
Published: December 2024

We describe the design and performance of a magnetic bottle electron spectrometer (MBES) for high-energy electron spectroscopy. Our design features a 2 m long electron drift tube and electrostatic retardation lens, achieving sub-electronvolt (eV) electron kinetic energy resolution for high energy (several hundred eV) electrons with a close to 4π collection solid angle. A segmented anode electron detector enables the simultaneous collection of photoelectron spectra in high resolution and high collection efficiency modes. This versatile instrument is installed at the time-resolved molecular and optical sciences instrument at the Linac Coherent Light Source x-ray free-electron laser (XFEL). In this paper, we demonstrate its high resolution, collection efficiency, and spatial selectivity in measurements where it is coupled to an XFEL source. These combined characteristics are designed to enable high-resolution time-resolved measurements using x-ray photoelectron, absorption, and Auger–Meitner spectroscopy. We also describe the pervasive artifact in MBES time-of-flight spectra that arises from a periodic modulation in electron collection efficiency and present a robust analysis procedure for its removal.
Stabilization of the Rayleigh–Bénard system by injection of thermal inertial particles and bubbles
Authors: Raza Saad , Hirata Silvia C. , Calzavarini Enrico
Published: December 2024

The effects of a dispersed particulate phase on the onset of Rayleigh–Bénard (RB) convection in a fluid layer are studied theoretically by means of a two-fluid Eulerian modelization. The particles are non-Brownian, spherical, with inertia and heat capacity, and are assumed to interact with the surrounding fluid mechanically and thermally. We study both the cases of particles denser and lighter than the fluid that are injected uniformly at the system's horizontal boundaries with their settling terminal velocity and prescribed temperatures. The performed linear stability analysis shows that the onset of thermal convection is stationary, i.e., the system undergoes a pitchfork bifurcation as in the classical single-phase RB problem. Remarkably, the mechanical coupling due to the particle motion always stabilizes the system, increasing the critical Rayleigh number (Rac) of the convective onset. Furthermore, the particle to fluid heat capacity ratio provides an additional stabilizing mechanism that we explore in full by addressing both the asymptotic limits of negligible and overwhelming particle thermal inertia. The overall resulting stabilization effect on Rac is significant: for a particulate volume fraction of 0.1%, it reaches up to a factor of 30 for the case of the lightest particle density (i.e., bubbles) and 60 for the heaviest one. This work extends the analysis performed by Prakhar and Prosperetti [“Linear theory of particulate Rayleigh-Bénard instability,” Phys. Rev. Fluids 6, 083901 (2021)], where the thermo-mechanical stabilization effect has been first demonstrated for highly dense particles. Here, by including the effect of the added-mass force in the model system, we succeed in exploring the full range of particle densities. Finally, we critically discuss the role of the particle injection boundary conditions which are adopted in this study and how their modification may lead to different dynamics that deserve to be explored in the future.
Magnetization patterns in GaAs-Fe33Co67 core–shell nanorods
Authors: Korniienko Anastasiia , Wartelle Alexis , Kronseder Matthias , Zeller Viola , Foerster Michael , Niño Miguel Ángel , Ruiz-Gomes Sandra , Khaliq Muhammad Waqas , Weigand Markus , Wintz Sebastian , Back Christian H.
Published: December 2024

We present a study on the static magnetic properties of individual GaAs-Fe33Co67 core–shell nanorods. X-ray magnetic circular dichroism combined with photoemission electron microscopy and scanning transmission x-ray microscopy were used to investigate the magnetic nanostructures. The magnetic layer is purposely designed to establish a magnetic easy axis neither along the nanostructure's long axis nor perpendicular to it to promote a 3D magnetic helical configuration on the tubular surface. In practice, two types of magnetic textures with in-plane magnetization were found inside the nanostructures' facets: magnetic domains with almost longitudinal or almost perpendicular magnetization with respect to the axis of the tube. We observe that a magnetic field applied perpendicular to the long axis of the nanostructure can add an azimuthal component of the magnetization to the previously almost longitudinal magnetization.
Experimental investigation on stability-enhancement mechanism of tip air injection in an axial-flow compressor with circumferential distortions
Authors: Liu Yang , Guan Di , Zhang Min , Li Jichao , Du Juan , Zhao Dan
Published: December 2024

We conduct experimental investigations of the effect of the tip air injection as a stability control method on a low-speed axial-flow compressor experiencing severe circumferential total pressure distortion. Eight Coanda-shaped injectors, uniformly distributed upstream of the rotor blade leading edge, were employed to counteract stall margin degradation caused by a flat-baffle circumferential distortion. Unsteady pressure data from the tip clearance and rotor wake regions were captured using time-resolved sensors and probes and analyzed through time-frequency transformation and proper orthogonal decomposition (POD) techniques. POD investigation under distorted inflow conditions reveals that the third-order POD mode, which characterizes unsteady tip leakage flow (TLF), plays a dominant role in triggering stall. Based on this insight, tip air injection with varying momentum ratios was applied to enhance the stall margin. The positive correlation between the injected momentum ratio and stall margin improvement was established, demonstrating the stabilizing effect of tip air injection under the circumferential distortion. The results indicate that tip air injection primarily acts on the rotor blade tip region to suppress the unsteady TLF at the center and downstream areas of the distortion, leading to an increase in tip blade load and a reduction in both the scale and number of pre-stall disturbances. However, the injection has a minimal impact on the unsteady TLF frequency band in the rotor wake region. Additionally, the POD analysis confirms that as the injection rate is increased, the energy percentage, flow field intensity, and power spectral density amplitude of the third-order POD mode are decreased, further reflecting the mitigation of unsteady TLF. The present work provides important insight into the stability control mechanisms of a tip air injection under circumferential distortion, offering design guidance for the implementation of active stability control strategies in axial-flow compressors.
Research on inter-plant weeding control in peanut at LADRC based on IACO-PSO optimization
Authors: Zhang Xiaolong , Xu Hongzhen , Liu Jiaodi , Quan Longzhe , Zhang Lichang , Zhang Bang
Published: December 2024

In the complex operating environments encountered in the field, control system parameters are often difficult to adjust, leading to issues such as excessive overshoot and poor anti-interference performance. These challenges make mechanical seedling avoidance and inter-plant weeding between peanut plants problematic, increasing the risk of seedling damage. To address this, this study investigated a Linear Active Disturbance Rejection Control (LADRC) system for peanut inter-plant weeding, optimized using an improved Ant Colony Optimization-Particle Swarm Optimization IACO-PSO algorithm. By controlling the angular velocity of the stepper motor, we were able to regulate seedling avoidance along the weeding knife’s operational path. A mathematical model for inter-plant seedling avoidance and weeding was established, and an improved hybrid algorithm combining the ant colony algorithm and particle swarm optimization was proposed to optimize the key parameters of the LADRC system. Benchmark function comparisons demonstrated that the improved algorithm offers a superior optimization performance and stability. Simulation experiments were then carried out to evaluate the control performance of the system in the inter-plant weeding scenario. The results show that, compared to other algorithms, the hybrid IACO-PSO algorithm exhibits faster convergence speeds and higher accuracy, significantly enhancing the system’s overall control performance. In particular, the IACO-PSO optimized control system reduced recovery times from disturbances by 96.6%, 75%, 82%, and 64.3%, respectively. These findings highlight the system’s strong anti-interference capability, robustness, and improved response speed, making it a highly effective solution for peanut inter-plant weeding.
The impact of Helicobacter pylori on gastric cancer formation and early warning signal identification
Authors: Yu Chong , Wang Jin
Published: December 2024

Gastric cancer is highly prevalent in Asia and is characterized by poor prognosis post-surgery and a high recurrence rate within five years. Research has highlighted the role of Helicobacter pylori in initiating or accelerating gastric cancer development. However, quantitative analysis of its impact on gastric cancer carcinogenesis is still lacking. This study employs gene regulatory networks and landscape and flux theory, integrating genetic and epigenetic factors, to quantitatively elucidate how Helicobacter pylori influences gastric cancer progression. Varied Helicobacter pylori infection concentrations lead to significant shifts in system thermodynamic and dynamic driving forces, altering gene expression levels. Quantitative analysis of entropy production rate and mean-flux in the gastric cancer system reveals the global changes in thermodynamic and dynamic driving forces. Coupled with autocorrelation, cross correlation, and variance analysis, we pinpoint critical stages of Helicobacter pylori infection, serving as early warning signals for gastric cancer. This approach bridges theoretical and clinical realms, dynamically assessing Helicobacter pylori’s impact on gastric cancer and identifying crucial early warning signals, with significant clinical and translational implications.
Slip length and rapid fluid flow in hybrid nanochannels
Authors: Rashidi R. , Wu Tianyu , Sun Chengzhen , Peeters F. M. , Neek-Amal M.
Published: December 2024

Recent advances in nanofabrication have highlighted the need for advanced theoretical models to accurately estimate fluid flow enhancement and slip length (δ) in hybrid nanochannels, where one wall consists of graphene and the other is composed of a different material. In this study, we extend the formalism of the enhancement factor for rapid fluid flow in nanochannels by incorporating two key elements: the Taylor–Aris dispersion (TD) effect and the slip characteristics of hybrid nanochannels. Our method based on the TD framework is proposed to precisely determine the unknown slip length in hybrid nanochannels. Additionally, we introduce a generalized enhancement factor for fluid flow through hybrid nanochannels with height H. This expression incorporates the Peclet number (Pe) and wall slip lengths, given by ε=g+β(1+ksPe2), and reduces to the traditional form ε=1+6δ/H for nonhybrid channels. The proposed framework not only bridges the gap between classical dispersion theory and modern nanofluidic systems but also offers quantitative insights into the interplay between slip length, channel dimensions, and flow enhancement. Furthermore, this work provides a robust theoretical foundation with practical implications for applications such as microfluidics, water filtration, and advanced material design.
Computational modeling of a human placentone: Simulating uteroplacental hemodynamics
Authors: Najmi A. , Grande Gutiérrez N.
Published: December 2024

During pregnancy, fetal growth depends on the efficient performance of the placenta. While in vivo measurements of the pregnant uterus are limited due to accessibility and safety concerns, computational modeling offers a tool for gaining valuable insights into healthy and complicated pregnancies. In this study, we present a computational model of the human placentone, the basic functional unit of the placenta. The model consists of maternal vasculature supplying (spiral artery) and draining (decidual veins) the placentone and the lobule, characterized by a villi-containing region and a free-of-villi region proximal to the arterial opening. To explore how uncertainties in placentone anatomy impact uteroplacental blood flow and intervillous space circulation, we systematically examine the sensitivity of key hemodynamic metrics to different placentone model parameters. These parameters include the location and diameter of the decidual veins, the size of the free-of-villi region at the spiral artery opening, and the extent of spiral artery remodeling. For our analysis, we consider arterial entry jet velocity and length, along with intervillous space pressure, as the hemodynamic metrics of interest. We define reference values for these metrics based on available experimental and clinical data on healthy pregnancies. Based on our simulation results, we identify the conditions that lead to a healthy and efficient placentone. We also model pathological cases representative of intrauterine fetal growth restriction and preeclampsia and quantify hemodynamic differences. Our results predict that in pathological cases, maternal blood enters the placentone with higher momentum than in the healthy case, potentially damaging the delicate placental villi.
Effects of the vena contracta for perforations on stability enhancement of an axial compressor using the impedance boundary-controlled casing treatment
Authors: Sun Dakun , Yang Mengyu , Dong Xu , Li Jia , Zhao Fengtong , Sun Xiaofeng
Published: December 2024

Casing treatments are extensively utilized in engineering to significantly enhance stability. The impedance boundary-controlled casing treatment (IBCCT), based on a three-dimensional compressible stability model, is one of the examples and has demonstrated a notable stall margin improvement in a series of extensive experiments. However, the impedance model employed to characterize the perforated plates in IBCCT falls short in considering complex geometric parameters, such as dimensionless thickness and perforation edge angle. With an aim to optimize geometric parameters, the impedance of perforated plates with different vena contracta is determined by appropriate boundary conditions within an acoustic resistance model in this study. These impedance values are integrated with previous models to perform sensitivity analysis. The appropriate cross-sectional profiles for perforation are designed to achieve the desired adjustment of different vena contracta. IBCCTs with different vena contracta are subjected to experimental validation to substantiate the predictions. The results of both the experiments and the sensitivity analysis indicate that the stall margin improvement of IBCCTs increases as the vena contracta decreases. In addition, single-passage numerical simulations are performed under casing treatment conditions to determine whether the IBCCT with varying vena contracta intensifies the impact on the steady flow field. By integrating sensitivity analysis, experimental data, and numerical simulations, the impact of vena contracta on the stability enhancement performance of IBCCTs can be elucidated.
Mathematical modeling for low-Mach-number compressible thermal convection analysis in a square enclosure
Authors: Satake Hidemoto , Tagawa Toshio
Published: December 2024

We derived a set of low-Mach-number compressible fluid-flow equations for analyzing thermal convection under large temperature differences and performed corresponding numerical simulations. This research has two key aspects. First, we propose a formulation for the perturbation of the equation of state. When considering the perturbation of the equation of state, we investigate the effects of a term that appears under high-temperature-difference conditions. Furthermore, we evaluate the analysis performance of the proposed formulation under the conventional low-temperature-difference conditions. Second, we perform calculations using a fully explicit algorithm, regardless of the temperature difference. This method eliminates the need for matrix calculations by artificially increasing the Mach number for the perturbation of the equation of state, thereby improving computational efficiency. This artificially adjusted Mach number is directly correlated with the calculation efficiency. However, since the maximum Mach number at which a physically appropriate flow field can be obtained depends on the computational conditions, the Mach number is also discussed. The present study confirms that the higher the temperature difference, the higher the adjustable range of the Mach number. Conversely, the lower the temperature difference, the lower the Mach number range, and the more limited the time step size. Furthermore, we confirmed that the temperature-difference conditions determine the efficiency of the incompressible fluid-flow analysis, encompassing solving the conventional pressure Poisson equation. Additionally, as in many studies, in natural convection in a square enclosure with a high-temperature-difference, the flow field exhibited an asymmetric distribution that differed from that obtained by the Boussinesq approximation.
Liquid fuels in rotating detonation engines: Advances and challenges
Authors: Zhu Yuejin , Zhang Shunli , Chen Huangwei , Wu Yu
Published: December 2024

The rotating detonation engine (RDE) has attracted considerable interest as a potential new propulsion system, owing to its ability to self-pressurize, its high thrust-to-weight ratio, and its simple structure. This paper provides a comprehensive review of the latest research advancements and challenges associated with the application of liquid fuels in RDEs. The study begins by focusing on the applicability of various liquid fuels in RDEs, examining the effects of fuel parameters—such as the equivalence ratio, the total temperature, the degree of pre-evaporation, and the droplet diameter—on detonation wave propagation and engine performance. Subsequently, the impact of inlet parameters and the optimization of combustor performance on detonation waves, along with control methods for mode-switching mechanisms, are investigated. Finally, the paper summarizes the common issues and challenges encountered in the application of liquid fuels in RDEs. These include droplet atomization, mixing and evaporation, detonation wave control, and combustor cooling. To address these challenges, future developments in RDEs may focus on four key areas: the use of complex fuels (such as blending fuels, sustainable aviation fuel, and other biofuels), detonation wave mode control, combustor cooling technologies, and the integration of RDEs with turbomachinery. These advancements will further propel the development of liquid-fueled rotating detonation technology.
The prospect of using hollow pyramidal microwave absorbers for 5G anechoic chamber applications: A review
Authors: Abu Sanad Ala A. , Mahmud Mohd Nazri , Ain Mohd Fadzil , Hussien Mousa , Bin Ahmad Mohd Azmier , Ariff Zulkifli Mohamad , Yahaya Nor Zakiah
Published: December 2024

Designing high-performance, wide bandwidth, lightweight, low-cost, and compact size absorbers for 5G anechoic chambers becomes essential. Several conventional absorbers, such as solid pyramidal absorbers, wedge absorbers, and convoluted absorbers, have shown acceptable absorption performance in a 5G mm-wave. However, these absorbers face challenges, such as narrow-angle of incidence, design complexity, and high cost. On the other hand, the hollow pyramidal absorber structures have a high level of freedom for optimization in order to be able to achieve the required specifications of 5G anechoic chambers. This paper provides an in-depth review of conventional absorber structures for use in anechoic chamber applications and their limitations for use in 5G applications, as well as the possibility of using hollow pyramidal absorbers in 5G anechoic chambers in comparison with conventional absorbers.
Influence of the geometric characteristics of media on the transition from Darcy to non-Darcy flow
Authors: Zhang Jiahong , Wang Tao , Chang Liangliang , Yu Li , Wang Hao , Zhao Yongchuan , Guo Xiaokang
Published: December 2024

Non-Darcy flow in pore media is a central challenge for subsurface energy extraction and geological conservation, and the effects of medium geometry features on the transition from Darcy to non-Darcy flow regimes in single-phase flow have not been comprehensively studied. This study quantitatively analyzed the impact of medium geometry features on the flow regime transition from the pore scale by constructing a series of two-dimensional models with different medium geometry features (particle disorder, particle radius, particle shape, and particle alignment angle). The results show that the geometric features influence the Darcy permeability and the flow regime transition by modulating the viscous dissipation rate of the system. With increasing disorder, a decrease in the particle radius, and a decrease in the number of polygonal edges, the system will enter the non-Darcy flow regime earlier. In addition, we analyze the intrinsic connection between vortices, the inertial core region, and medium geometrical features in the non-Darcy flow regime by introducing a typical pore–throat model. The non-Darcy flow regime transitions from a vortex-dominated state to an inertial core region-dominated state as the azimuthal angle of the medium pore increases.
A Pluronic block copolymer in H2O and D2O: The isotope effect on phase transition
Authors: Di Spirito Nicola Antonio , Auriemma Finizia , Ruiz de Ballesteros Odda , Grizzuti Nino , Pasquino Rossana
Published: December 2024

Pluronic block copolymers are thermosensitive amphiphilic materials capable of self-assembling with various phases in water environments, depending on temperature and concentration. The phase transitions of high-concentrated Pluronic solutions in water (H2O) and heavy water (D2O) were observed via experimental rheology and small-angle x-ray scattering, to discover the isotope effect on the system phase and conformational properties. Aqueous solutions of Pluronic F68 in the presence of diclofenac sodium were used as the test material, being efficient drug delivery systems. Such materials undergo a reversible thermal phase transition, moving from a micellar liquid phase to a body-centered cubic solid structure with increasing temperature. The substitution of water by heavy water as a solvent has a noticeable influence on the Pluronic phase behavior. The liquid-to-solid transition temperatures of the Pluronic-based hydrogels in D2O are about 10 °C lower than those in H2O. Nonetheless, the deuterium isotope does not alter the characteristic dimensions of the Pluronic F68 self-assemblies. These results evidence that the properties and phase behavior of amphiphilic materials as Pluronics can be hugely influenced by the solvent isotopic composition. The significance of the findings also hinges on the crucial role that experimental methodologies play in understanding the link between the system macroscopic flow properties and the corresponding microstructural evolution. Indeed, the common practices for experimentally characterizing Pluronic solutions—such as rheology and scattering techniques—often provide their bulk and microstructural description without discerning between the material preparation in water and deuterated water, implicitly assuming no thermodynamical and physical chemistry modifications by isotopic substitution.
Integrating symbolic regression with physics-informed neural networks for simulating nonlinear wave dynamics in arterial blood flow
Authors: Changdar Satyasaran , Bhaumik Bivas , Sadhukhan Nabanita , Pandey Sumit , Mukhopadhyay Sabyasachi , De Soumen , Bakalis Serafim
Published: December 2024

This study explores a hybrid framework integrating machine learning techniques and symbolic regression via genetic programing for analyzing the nonlinear propagation of waves in arterial blood flow. We employ a mathematical framework to simulate viscoelastic arterial flow, incorporating assumptions of long wavelength and large Reynolds numbers. We used a fifth-order nonlinear evolutionary equation using reductive perturbation to represent the behavior of nonlinear waves in a viscoelastic tube, considering the tube wall's bending. We obtain solutions through physics-informed neural networks (PINNs) that optimizes via Bayesian hyperparameter optimization across three distinct initial conditions. We found that PINN-based models are proficient at predicting the solutions of higher-order nonlinear partial differential equations in the spatial-temporal domain [−1,1]×[0,2]. This is evidenced by graphical results and a residual validation showing a mean absolute residue error of O(10−3). We thoroughly examine the impacts of various initial conditions. Furthermore, the three solutions are combined into a single model using the random forest machine learning algorithm, achieving an impressive accuracy of 99% on the testing dataset and compared with another model using an artificial neural network. Finally, the analytical form of the solutions is estimated using symbolic regression that provides interpretable models with mean square error of O(10−3). These insights contribute to the interpretation of cardiovascular parameters, potentially advancing machine learning applications within the medical domain.
Multimessenger observations and the science enabled: continuous waves and their progenitors, equation of state of dense matter
Authors: Jones D I , Riles K
Published: December 2024

Rotating and oscillating neutron stars can give rise to long-lived Continuous Gravitational Waves (CGWs). Despite many years of searching, the detection of such a CGW signal remains elusive. In this article we describe the main astrophysical uncertainties regarding such emission, and their relation to the behaviour of matter at extremely high density. We describe the main challenges in searching for CGWs, and the prospects of detecting them using third-generation gravitational wave detectors. We end by describing some pressing issues in the field, whose resolution would help turn the detection and exploitation of CGWs into reality.
Evaluation of the influence of rain on air surface temperature measurements
Authors: Nielsen Jan , Bottacin Alberto , Østergaard Peter , Nielsen Tommy , Rasmussen Morten Karstoft , Musacchio Chiara , Coppa Graziano , Merlone Andrea
Published: December 2024

Reliable measurements of surface air temperature are crucial in meteorology and climatology. Thermometers must be shielded to avoid atmospheric influence factors, such as solar radiation and rainfall, compromise their accuracy. In the standard document ISO 17 714, which defines test methods for performance comparison of different screens, potential error sources caused by rainfall are mentioned. Besides the well-known psychrometric effect, an error on the temperature reading related to the difference between air and rain temperature causing heat transfer from water to the thermometer is identified. Despite the high relevance, no studies are available in literature that analyze this effect. The work described in this paper aims at quantifying the influence of the rain on the readings of temperature sensors, with radiation screens of different types. The study was performed by introducing an artificial rainfall generator where the water temperature and rain intensity was controlled and comparing the readings of thermometers under the generated rainfall with respect to a developed reference system not affected by rain. The tests show that the error for especially naturally ventilated thermometers can be unacceptably large, up to −4.0 (0.2) K, whereas for the artificially ventilated air thermometers the errors observed are less significant, smaller than −1.1 (0.2) K. This preliminary study underscores the critical influence of rain temperature and intensity on thermometer readings and highlights the importance of further research to develop standardized testing protocols. The reported methodology can also help to develop future standardized test protocol to qualify the device with regards to the measurement error.