bluuebunny/crossref_metadata_2025 huggingface dataset:
Photoinduced charge separation and DNA self-repair depend on sequence directionality and stacking pattern
Authors: Kufner Corinna L. , Crucilla Sarah , Ding Dian , Stadlbauer Petr , Šponer Jiří , Szostak Jack W. , Sasselov Dimitar D. , Szabla Rafał
Published: December 2023

The exposure of DNA to UV light may result in electron transfer between the bases. It can entail self-repair of common DNA lesions and the efficiency of these two processes is controlled by stacking overlap of the nucleobases.
Solid-state sodium batteries with P2-type Mn-based layered oxides by utilizing anionic redox
Authors: Kmiec Steven , Vanaphuti Panawan , Manthiram Arumugam
Published: December 2023

Solid-state sodium-metal batteries assembled with a composite solid-electrolyte separator and Na0.72Li0.24Mn0.75Si0.01O2 cathode, utilizing reversible cationic (Mn) and anionic (O) redox, achieve high initial specific capacity of 180 mA h g−1.
Joint AP‐user association and caching strategy for delivery delay minimization in cell‐free massive MIMO systems
Authors: Wang Rui , Shen Min , He Yun , Liu Xiangyan
Published: December 2023

Edge caching at access points (APs) is a promising approach to alleviate the fronthaul burden and reduce user‐perceived delay. However, the edge caching placement is still challenging considering the coupling between caching and AP‐user association, limited fronthaul capacity, and multi‐AP deployment in the cell‐free (CF) massive MIMO systems. To this end, the authors establish a framework for the joint problem of AP‐user association and caching to minimize the content delivery delay which considers both cooperation delivery delay and radio access delay. It is an integer nonlinear programming problem and NP‐hard. The optimization problem is first decomposed into an AP‐user association sub‐problem and a caching placement sub‐problem to address this problem. A two‐stage matching algorithm is further proposed to achieve AP‐user association and a modified genetic algorithm to determine caching placement. A computationally efficient iterative algorithm is developed to solve the joint optimization problem. Finally, the global convergence and computational complexity of the proposed strategy are analyzed theoretically. Simulation results reveal that the proposed strategy can achieve better delivery delay performance than benchmark schemes.
Reliability of Neuronavigation in Localizing the Internal Acoustic Canal during Middle Fossa Approach
Authors: Kartum Tufan Agah , Kucukyuruk Baris , Kaya Alperen , Aydin Levent , Tanrıöver Necmettin , Sanus Galip Zihni
Published: December 2023

Objective The absence of precise landmarks in the middle fossa floor and frequent anatomical variations make it difficult to localize the internal acoustic canal (IAC) during the middle fossa approach (MFA). We aimed to investigate the reliability and utility of the neuronavigation system (NNS) in the MFA and to delineate specific technical considerations regarding NNS during the approach.

Method One-millimeter-thin section computed tomography scans were performed on five formalin-fixed human cadavers (10 sides). During the MFA, structures, such as the IAC, vestibule and cochlea hidden in the temporal bone were investigated under NNS guidance.

Results All the superficial landmarks, such as the foramen spinosum and ovale were correctly localized by NNS. Deeper landmarks, such as the central part of the IAC lying beneath the surface of the petrous apex could not be localized via NNS. The exact area of bone removal along roof of IAC was determined by using the orientation provided by the probe placed between the basal turn of cochlea and the vestibule. We were able to validate the location of the IAC via a medial to lateral drilling by using the navigation this reference point.

Conclusion The NNS can be used effectively during the MFA, and localizing superficial landmarks on the middle fossa floor with a higher accuracy may prove helpful in identifying the IAC from above. By referring to the cochlea–vestibule junctional area, the exact location of the trace of the IAC can be revealed.
An Improved and Scalable Synthesis of the Potent SREBP Inhibitor KK-052 via [3+2] Cycloaddition
Authors: Kittaka Atsushi , Kawagoe Fumihiro , Mototani Sayuri , Takemoto Yasushi , Uesugi Motonari
Published: December 2023

KK-052 is a novel vitamin-D-based selective sterol regulatory element-binding protein (SREBP) suppressor that lacks vitamin D genomic activity mediated through the vitamin D receptor in both in vitro and in vivo settings. In our initial synthetic effort, KK-052 was produced as one of the structural isomers obtained via the Mitsunobu reaction involving a CD-ring allyl alcohol and 5-phenyl-1H-tetrazole. In this work, we present a refined methodology for enhancing the selective synthesis of KK-052 through a [3+2] cycloaddition between a CD-ring benzimidoyl chloride and sodium azide, a technique that proved amenable to gram-scale production. Additionally, this synthetic method permitted the production of a more potent m-methyl analogue of KK-052.
Clinical Outcome of Monochorionic Diamniotic Twins with Intrauterine Growth Restriction
Authors: Qiu Tian , Cheng Weiwei , Chen Yan , Guo Yuna , Shen Hong , Xu Liang
Published: December 2023

Objective This study investigated the clinical outcome of monochorionic diamniotic (MCDA) twins with selective intrauterine growth restriction (sIUGR).

Study Design International Peace Maternal and Child Health Hospital of Shanghai ultrasound database was investigated to identify all MCDA delivered from January 2013 to December 2017. After identifying 43 pairs of MCDA twins with sIUGR and 282 pairs of normal MCDA twins, we compared clinical outcomes between the two groups.

Results Compared with normal twins, sIUGR fetuses had significantly shorter gestational age at delivery, smaller average birth weight of both twins, more significant intertwin difference in birth weight, lower Apgar scores, and higher intrauterine fetal demise (IUFD) rate, and smaller placental weight. The rate of abnormal umbilical cord insertions and abnormal blood flow in the ductus venosus (DV) and middle cerebral artery (MCA) is significantly higher in the sIUGR group. In addition, the subtype analysis of sIUGR groups indicated the poorest outcomes in type II with no significant difference between type I and III.

Conclusion MCDA twins with sIUGR generally exhibited limited clinical outcomes than normal MCDA twins. These limitations are mainly associated with abnormal umbilical cord insertions and blood flow in the DV and MCA. Clinical outcomes differed among the three types of sIUGR, with type II having the worst prognosis and the highest IUFD rate.

Key points
Clinical Manifestation and Treatment of Allergic Bronchopulmonary Aspergillosis
Authors: Agarwal Ritesh , Muthu Valliappan , Sehgal Inderpaul S.
Published: December 2023

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction to airway colonization by Aspergillus fumigatus in patients with asthma and cystic fibrosis. The pathophysiology of ABPA involves a complex interplay between the fungus and the host immune response, which causes persistent inflammation and tissue damage. Patients present with chronic cough, wheezing, and dyspnea due to uncontrolled asthma. Characteristic symptoms include the expectoration of brownish mucus plugs. Radiographic findings often reveal fleeting pulmonary infiltrates, bronchiectasis, and mucus impaction. However, the definitive diagnosis of ABPA requires a combination of clinical, radiological, and immunological findings. The management of ABPA aims to reduce symptoms, prevent disease progression, and minimize the future risk of exacerbations. The treatment approach involves systemic glucocorticoids or antifungal agents to suppress the inflammatory response or fungal growth and prevent exacerbations. Biological agents may be used in patients with severe disease or glucocorticoid dependence. This review provides an overview of the clinical manifestations and current treatment options for ABPA.
Radiological Differential Diagnoses Based on Cardiovascular and Thoracic Imaging Patterns: Perspectives of Four Large Language Models
Authors: Sarangi Pradosh Kumar , Irodi Aparna , Panda Swaha , Nayak Debasish Swapnesh Kumar , Mondal Himel
Published: December 2023

Background Differential diagnosis in radiology is a critical aspect of clinical decision-making. Radiologists in the early stages may find difficulties in listing the differential diagnosis from image patterns. In this context, the emergence of large language models (LLMs) has introduced new opportunities as these models have the capacity to access and contextualize extensive information from text-based input.

Objective The objective of this study was to explore the utility of four LLMs—ChatGPT3.5, Google Bard, Microsoft Bing, and Perplexity—in providing most important differential diagnoses of cardiovascular and thoracic imaging patterns.

Methods We selected 15 unique cardiovascular (n = 5) and thoracic (n = 10) imaging patterns. We asked each model to generate top 5 most important differential diagnoses for every pattern. Concurrently, a panel of two cardiothoracic radiologists independently identified top 5 differentials for each case and came to consensus when discrepancies occurred. We checked the concordance and acceptance of LLM-generated differentials with the consensus differential diagnosis. Categorical variables were compared by binomial, chi-squared, or Fisher's exact test.

Results A total of 15 cases with five differentials generated a total of 75 items to analyze. The highest level of concordance was observed for diagnoses provided by Perplexity (66.67%), followed by ChatGPT (65.33%) and Bing (62.67%). The lowest score was for Bard with 45.33% of concordance with expert consensus. The acceptance rate was highest for Perplexity (90.67%), followed by Bing (89.33%) and ChatGPT (85.33%). The lowest acceptance rate was for Bard (69.33%).

Conclusion Four LLMs—ChatGPT3.5, Google Bard, Microsoft Bing, and Perplexity—generated differential diagnoses had high level of acceptance but relatively lower concordance. There were significant differences in acceptance and concordance among the LLMs. Hence, it is important to carefully select the suitable model for usage in patient care or in medical education.
The Role of Preprocedure Genetic Counseling in Pregnancies Interrupted for Fetal Abnormalities
Authors: Francoeur Alex A. , Kang Sung-Hae L. , Senaratne T. Niroshi , Saitta Sulagna , Murali Aparna , Peters Katharine , Hansman Emily , Chen Angela , Parvataneni Ram , Patil Rajita , Rible Radhika , Sridhar Aparna , Stoddard Amy , Zapata Mya , Krakow Deborah , Pluym Ilina D.
Published: December 2023

Objective Congenital birth defects affect 3 to 5% of pregnancies. Genetic counseling can help patients navigate the testing process and understand results. The study objective was to identify predictors and utility of genetic counseling at the time of pregnancy termination. Additionally, we aimed to see what proportion of patients would benefit from additional testing based on the results of the genetic testing.

Study Design This was a retrospective cohort review of all terminations performed for fetal anomalies by an academic center from July 2016 to May 2020. Indications were stratified by abnormal serum screening or types of abnormal ultrasound findings. Data were abstracted regarding uptake of genetic counseling and testing results. Abnormal results that warranted additional testing regarding recurrence risks were noted. Multivariable logistic regression was performed to identify predictors of receipt of genetic counseling and testing.

Results Of 387 patients, 57% (n = 220) received preprocedure genetic counseling and 43% (n = 167) did not. Among patients who received diagnostic testing, 62% (n = 194) had genetic counseling compared with 38% (n = 121) without counseling (adjusted odds ratio 2.46, 95% confidence interval [1.41–4.29], p < 0.001). Among the entire cohort, 38% (n = 148) had suspected aneuploidy based on serum screening. Of these, 89% (n = 132/148) had definitive testing, 92% (n = 122/132) confirming the aneuploidy. Among the other 68% (n = 239) with structural anomalies, 76% (n = 183) had diagnostic testing with 29% (n = 53) yielding an abnormal result. Among those fetuses with structural anomalies, 36% (n = 19/53) of genetic diagnoses warranted additional parental testing because of risk of recurrence compared with only 2% (n = 2/122) of patients with abnormal serum screening results alone.

Conclusion Genetic counseling was associated with increased uptake of diagnostic testing, which yielded useful information and prompted additional testing. This is important for determining etiology and recurrence risk and should be offered to patients presenting for termination for fetal indications, as well as providing diagnostic closure for patients.

Key Points
Macrodystrophia Lipomatosa: A Rare Case of Ulnar Nerve Territory Involvement
Authors: Ullal Sonali , Arora Shivani
Published: December 2023

Macrodystrophia lipomatosa (MDL) is a rare congenital, nonhereditary anomaly characterized by overgrowth of all the mesenchymal elements, predominantly the fibroadipose tissue in a sclerotomal distribution commonly involving the median nerve territory in the upper extremity and plantar nerve territory in the lower extremity. It can be either static or progressive, with the former being the more common. MDL is usually present since birth and the affected digit/region increases in length and girth, and growth ceases after puberty. We discuss a rare case of ulnar nerve territory involvement that progressed to grow even after puberty.
Incidence and Management of Neonatal Pneumothorax in a 10-Hospital Regional Perinatal Network in Switzerland: A Retrospective Observational Study
Authors: Baudat-Nguyen Julie , Schneider Juliane , Roth-Kleiner Matthias , Barrielle Laureline , Diebold Patrick , Duvoisin Gilles , El Faleh Ikbel , Grupe Silke , Huber Benedikt M. , Morel Anne-Sophie , Paccaud Yan , Torregrossa Anais , Younes Dany , Tolsa Jean-François , Truttmann Anita C.
Published: December 2023

Objective Pneumothorax (PTX) is a potentially life-threatening condition that affects neonates, with an incidence of 0.05 to 2%. Its management includes conservative treatment, chest tube (CT) drainage, and needle aspiration (NA). Aims were to evaluate the incidence of PTX in a 10-hospital perinatal network, its clinical characteristics and risk factors, and to compare the different treatment options.

Study Design All neonates diagnosed with PTX and hospitalized in the network were included in this retrospective observational trial over a period of 30 months. Primary outcome was the incidence of PTX. Secondary outcomes were the treatment modality, the length of stay (LOS), and the number of chest X-rays.

Results Among the 173 neonates included, the overall incidence of PTX was 0.56 per 100 births with a large range among the hospitals (0.12–1.24). Thirty-nine percent of pneumothoraces were treated conservatively, 41% by CT drainage, 13% by NA, and 7% by combined treatment. Failure rate was higher for NA (37%) than for CT drainage (9%). However, the number of X-rays was lower for patients treated by NA, with a median of 6 (interquartile range [IQR] 4–6.25), than by CT drainage, with a median of 9 (IQR 7–12). LOS was shorter for NA than for CT drainage, with a median of 2 (IQR 1–4.25) and 6 days (IQR 3–15), respectively. Complications, including apnea and urinary retention, occurred in 28% of patients managed with CT drainage, whereas none was observed with NA.

Conclusion High variability of PTX incidence was observed among the hospitals within the network, but these values correspond to the literature. NA showed to reduce the number of X-rays, the LOS, and complications compared with CT drainage, but it carries a high failure rate. This study helped provide a new decisional management algorithm to harmonize and improve PTX treatment within our network.

Key Points
Almansi decomposition of polynomials of quaternionic Dirac operators
Authors: Ren Guangbin , Zhang Lizheng
Published: December 2023

This article presents an innovative extension of the classical Almansi decomposition. Traditionally, the Almansi decomposition is employed to decompose polymonogenic functions into their monogenic counterparts, thereby elucidating the relationship between the Dirac operator and its successive iterations. Diverging from this conventional method, the new extension delves into the kernel of a polynomial related to the quaternionic Dirac operator, as opposed to focusing on the iterated operator. This is achieved by employing a polynomial-based partition of unity. The outcome of this approach is a distinctive decomposition that leverages the kernel of the Dirac–Helmholtz operators.
Luminescence coupling in 28.4%-efficient tandem solar cell utilizing 20.8%-efficient perovskite minimodule stacked on silicon cell
Authors: Mishima Ryota , Yoshida Wataru , Ishibashi Hirotaka , Tanaka Haruki , Kishimoto Kazuhisa , Hino Masashi , Kanematsu Masanori , Okamoto Shimpei , Fujimoto Takahisa , Koizumi Gensuke , Uzu Hisashi , Adachi Daisuke , Yamamoto Kenji
Published: December 2023

The total power conversion efficiency (PCE) of 28.4% with an aperture area of 64 cm2 on a four-terminal (4T) tandem solar cell with a 20.8% efficiency-semitransparent perovskite module (SPM) with a series interconnection structure and a conventional passivated emitter and rear cell type crystalline silicon solar cell is independently confirmed. This is the independently confirmed record PCE of a 4T perovskite and crystalline silicon tandem solar cell with a structure having the same active area for both top and bottom cells. The impact of the luminescence coupling monitored by the silicon solar cell in the 4T tandem solar cell was investigated based on electrical properties of the top SPM analyzed by a simple one-diode equivalent circuit model.
Numerical study of owls' leading-edge serrations
Authors: Nafi Asif Shahriar , Beratlis Nikolaos , Balaras Elias , Gurka Roi
Published: December 2023

Owls' silent flight is commonly attributed to their special wing morphology combined with wingbeat kinematics. One of these special morphological features is known as the leading-edge serrations: rigid miniature hook-like patterns found at the primaries of the wings' leading-edge. It has been hypothesized that leading-edge serrations function as a passive flow control mechanism, impacting the aerodynamic performance. To elucidate the flow physics associated with owls' leading-edge serrations, we investigate the flow-field characteristic around a barn owl wing with serrated leading-edge geometry positioned at 20° angle of attack for a Reynolds number of 40 000. We use direct numerical simulations, where the incompressible Navier–Stokes equations are solved on a Cartesian grid with sufficient resolution to resolve all the relevant flow scales, while the wing is represented using an immersed boundary method. We have simulated two wing planforms: with serrations and without. Our findings suggest that the serrations improve suction surface flow by promoting sustained flow reattachment via streamwise vorticity generation at the shear layer, prompting weaker reverse flow, thus augmenting stall resistance. Aerodynamic performance is negatively impacted due to the shear layer passing through the serration array, which results in altered surface pressure distribution over the upper surface. In addition, we found that serrations increase turbulence level in the downstream flow. Turbulent momentum transfer near the trailing edge increased due to the presence of serrations upstream the flow, which also influences the mechanisms associated with separation vortex formation and its subsequent development over the upper surface of the wing.
Impact of time varying interaction: Formation and annihilation of extreme events in dynamical systems
Authors: Leo Kingston S. , Kumaran Gayathri , Ghosh Anupam , Kumarasamy Suresh , Kapitaniak Tomasz
Published: December 2023

This study investigates the emergence of extreme events in two different coupled systems: the FitzHugh–Nagumo neuron model and the forced Liénard system, both based on time-varying interactions. The time-varying coupling function between the systems determines the duration and frequency of their interaction. Extreme events in the coupled system arise as a result of the influence of time-varying interactions within various parameter regions. We specifically focus on elucidating how the transition point between extreme events and regular events shifts in response to the duration of interaction time between the systems. By selecting the appropriate interaction time, we can effectively mitigate extreme events, which is highly advantageous for controlling undesired fluctuations in engineering applications. Furthermore, we extend our investigation to networks of oscillators, where the interactions among network elements are also time dependent. The proposed approach for coupled systems holds wide applicability to oscillator networks.
A numerical study on the blade–vortex interaction of a two-dimensional Darrieus–Savonius combined vertical axis wind turbine
Authors: Pan Jingna , Ferreira Carlos , van Zuijlen Alexander
Published: December 2023

To investigate power losses of a Darrieus–Savonius combined vertical axis wind turbine (hybrid VAWT) associated with the interaction between blades and wake, it is crucial to understand the flow phenomena around the turbine. This study presents a two-dimensional numerical analysis of vortex dynamics for a hybrid VAWT. The integration of a Savonius rotor in the hybrid VAWT improves self-starting capability but introduces vortices that cause transient load fluctuations on the Darrieus blades. This study attempts to characterize the flow features around the hybrid VAWT and correlate them with the Darrieus blade force variation in one revolution. Results demonstrate the capability of numerical modeling in handling a wide range of operational conditions: the relevant position of Savonius and Darrieus blades (attachment angle γ=0°−90°) and Savonius' tip speed ratio λS (0.2–0.8, varied Savonius' rotational speed). The torque increase in the Darrieus blade in hybrid VAWT (compared to a single Darrieus rotor) due to the appearance of the vortex shedding from the advanced Savonius blade is independent of the attachment angle and tip speed ratio. Apart from start-up and power performances of the hybrid VAWT, the most rapid force fluctuation is identified when the Darrieus blade interacts with Savonius' wake at γ=0° and λS=0.8, which is considered undesirable. Furthermore, attachment angles of 60° and 90° exhibit better power coefficients compared to those of 0° and 30° for the hybrid VAWT. This study contributes to a comprehensive understanding of flow dynamics in hybrid VAWTs, revealing the correlation between torque variation and vortex development.
Quantum discord and Fisher information for two-qubit system in the presence of thermal fields
Authors: Algarni M. , Abdel-Khalek S. , Berrada K.
Published: December 2023

We consider a double Jaynes–Cummings model for a system of two atoms that interact with a radiation field defined in a thermal spin state. We examine the impact of the parameters of the quantum model on the temporal evolution of quantum discord, quantum Fisher information, and fidelity. We explain how the quantifiers can be affected by the thermal noise and spin number with and without the effect of time-dependent coupling. We show that, despite the damaging effects of thermal noise, there is still some amount of discord and Fisher information present during the temporal evolution in accordance with the values of the spin number.
Rheodynamics of viscoelastic subdiffusive channel flows: Low Weissenberg number regime
Authors: Chauhan T. , Bhatt M. , Shrivastava S. , Shukla P. , Sircar S.
Published: December 2023

Direct numerical simulations of viscoelastic, subdiffusive, and plane Poiseuille flow, representing thick polymer solutions including polymer melts, flows of liquid crystals, as well as biological flow such as mucus, are reported. The stress strain equation is fundamentally derived by relating the timescale exponent at the microscale (tα, with 0<α≤1) with the fractional order of the time derivative, α, of the corresponding non-linear equation in the continuum. The resultant stress constitutive equation is the fractional variant of the well-known upper convected Maxwell equation. In order to quantify the formation of spatiotemporal macrostructures (or the non-homogeneous regions of high viscosity at moderate to high fluid inertia), the space of symmetric positive definite polymer conformation tensors is visualized using a Riemannian metric along with its three scalar invariants. Numerical simulations of the channel flow, in the regime of low to moderate Reynolds number and low Weissenberg number, effectively capture these flow-structures by providing (i) a better resolution of the instantaneous regions of elastic shocks (which are the alternating regions of expanded and compressed polymer volume, in comparison with the volume of the mean conformation tensor), and (ii) a better resolution to detect neighborhoods where the mean conformation tensor tends to be significantly different in comparison to the instantaneous conformation tensor, thereby corroborating the experimentally observed flow-instability transition of subdiffusive flows. Finally, the strength of the subdiffusive flow model and the invariant theory is highlighted through an application of an electrohydrodynamic micropump.
Analytic gradients for relativistic exact-two-component equation-of-motion coupled-cluster singles and doubles method
Authors: Zhang Chaoqun , Zheng Xuechen , Liu Junzi , Asthana Ayush , Cheng Lan
Published: December 2023

A first implementation of analytic gradients for spinor-based relativistic equation-of-motion coupled-cluster singles and doubles method using an exact two-component Hamiltonian augmented with atomic mean-field spin–orbit integrals is reported. To demonstrate its applicability, we present calculations of equilibrium structures and harmonic vibrational frequencies for the electronic ground and excited states of the radium mono-amide molecule (RaNH2) and the radium mono-methoxide molecule (RaOCH3). Spin–orbit coupling is shown to quench Jahn–Teller effects in the first excited state of RaOCH3, resulting in a C3v equilibrium structure. The calculations also show that the radium atoms in these molecules serve as efficient optical cycling centers.
The impact of boron doping in the tunneling magnetoresistance of Heusler alloy Co2FeAl
Authors: Habiboglu Ali , Chandak Yash , Khanal Pravin , Larsen Brecken , Zhou Bowei , Eckel Carter , Cutshall Jacob , Warrilow Kennedy , O’Brien John , Hong Brady , Schaibley John R. , Leroy Brian J. , Wang Weigang
Published: December 2023

Heusler alloy-based magnetic tunnel junctions have the potential to provide high spin polarization, small damping, and fast switching. In this study, junctions with a ferromagnetic electrode of Co2FeAl were fabricated via room-temperature sputtering on Si/SiO2 substrates. The effect of boron doping on Co2FeAl magnetic tunnel junctions was investigated for different boron concentrations. The surface roughness determined by atomic force microscope, and the analysis of x-ray diffraction measurement on the Co2FeAl thin film reveals critical information about the interface. The Co2FeAl layer was deposited on the bottom and on the top of the insulating MgO layer as two different sample structures to compare the impact of the boron doping on different layers through tunneling magnetoresistance measurements. The doping of boron in Co2FeAl had a large positive impact on the structural and magneto-transport properties of the junctions, with reduced interfacial roughness and substantial improvement in tunneling magnetoresistance. In samples annealed at low temperature, a two-level magnetoresistance was also observed. This is believed to be related to the memristive effect of the tunnel barrier. The findings of this study have practical uses for the design and fabrication of magnetic tunnel junctions with improved magneto-transport properties.
Investigation of compressible flow under low Mach number in an enclosed square cavity with a novel non-Boussinesq algorithm
Authors: Zhang Jinsong , Wu Yongyong , Gui Nan , Yang Xingtuan , Tu Jiyuan , Jiang Shengyao
Published: December 2023

Natural convection is widely observed in various scales of natural phenomena and industrial applications. The low Mach number (i.e., low-velocity) natural convection, especially under large temperature differences and significant density and pressure fluctuations, is of great research significance in industrial fields such as nuclear engineering. The Boussinesq approximation based on the incompressible Navier–Stokes (NS) equation is not fully descriptive due to the neglect of coupling effects among temperature, density, and pressure. As for numerical algorithms based on the compressible Navier–Stokes equation, they often suffer from high computational costs and convergence difficulties. In this paper, a novel numerical algorithm based on the decoupled and stabilized Lattice Boltzmann multiphase model with a complete physical description and clear conceptual framework is proposed. It couples the equation of state and the temperature equation, considering the full effects of gravity, pressure, and temperature-dependent density on flow disturbances, and it recovers the complete compressible NS equation. Taking the natural convection in an enclosed cavity as an example, the non-dimensional numbers governing the fluid system are identified by Buckingham π theorem; thus, a new thermal expansion number is proposed to connect the pressure effect. The accuracy and reliability of the numerical algorithm are validated by comparing it with standard benchmarks. On this basis, the proposed algorithm enables a unified physical description from low to high Rayleigh numbers and from small to large temperature differences. By analyzing the flow and heat transfer characteristics of natural convection under different Rayleigh numbers, temperature differences, and thermal expansion numbers, this study reveals the coupled physical mechanisms of low Mach number flow from small to large temperature differences, from low to high Rayleigh numbers and under different thermal expansion numbers.
A numerical study supplemented with theoretical analysis on streaming potential in a soft nanochannel influenced by ion partitioning and mobile surface charge-dependent wall slip
Authors: Sahu Shubhra , Mondal Bapan , Bhattacharyya Somnath
Published: December 2023

We consider the pressure-driven flow of an electrolyte in a soft channel with a hydrophobic charged surface coated with a diffuse polyelectrolyte layer (PEL) with constant volumetric charge density. The objectives are to enhance the streaming potential and electrochemical energy conversion efficiency in the modulated soft channel as well as to examine the influence of surface charge mobility-dependent slip velocity on the electrokinetics. The laterally mobile adsorbed surface charge modifies the slip velocity condition, which is coupled with the induced streaming potential. The ion partitioning effect arises due to the step change in dielectric constant between the PEL and the electrolyte that modifies the distribution of ions, which is incorporated through the Born energy difference of ions. The nonlinear coupled set of equations governing the electrokinetics in a soft channel is solved numerically through a control volume approach. A simplified model based on the Debye–Hückel approximation under certain limiting conditions is also derived, which compares well with the present numerical model for a lower range of charge density and non-overlapping Debye layers. We find that a modulation of a nanochannel by coating a PEL of lower dielectric constant on hydrophobic charged walls can significantly enhance the streaming current and energy conversion efficiency. In contrast with existing studies, we find that the mobile surface charge can have a positive impact on the electrochemical energy conversion efficiency in a soft nanochannel. The mobility of the surface charge attenuates the streaming current in a PEL-free channel and can enhance the streaming current for a suitable choice of PEL volumetric charge density.
Underlying mechanisms of gold nanoalloys stabilization
Authors: Pena Lucas B. , Da Silva Lucas R. , Da Silva Juarez L. F. , Galvão Breno R. L.
Published: December 2023

Gold nanoclusters have attracted significant attention due to their unique physical-chemical properties, which can be tuned by alloying with elements such as Cu, Pd, Ag, and Pt to design materials for various applications. Although Au-nanoalloys have promising applications, our atomistic understanding of the descriptors that drive their stability is far from satisfactory. To address this problem, we considered 55-atom model nanoalloys that have been synthesized by experimental techniques. Here, we combined data mining techniques for creating a large sample of representative configurations, density functional theory for performing total energy optimizations, and Spearman correlation analyses to identify the most important descriptors. Among our results, we have identified trends in core–shell formation in the AuCu and AuPd systems and an onion-like design in the AuAg system, characterized by the aggregation of gold atoms on nanocluster surfaces. These features are explained by Au’s surface energy, packing efficiency, and charge transfer mechanisms, which are enhanced by the alloys’ preference for adopting the structure of the alloying metal rather than the low-symmetry one presented by Au55. These generalizations provide insights into the interplay between electronic and structural properties in gold nanoalloys, contributing to the understanding of their stabilization mechanisms and potential applications in various fields.
ALK signaling primes the DNA damage response sensitizing ALK-driven neuroblastoma to therapeutic ATR inhibition
Authors: Borenäs Marcus , Umapathy Ganesh , Lind Dan E. , Lai Wei-Yun , Guan Jikui , Johansson Joel , Jennische Eva , Schmidt Alexander , Kurhe Yeshwant , Gabre Jonatan L. , Aniszewska Agata , Strömberg Anneli , Bemark Mats , Hall Michael N. , Eynden Jimmy Van den , Hallberg Bengt , Palmer Ruth H.
Published: December 2023

High-risk neuroblastoma (NB) is a significant clinical challenge. MYCN and Anaplastic Lymphoma Kinase (ALK), which are often involved in high-risk NB, lead to increased replication stress in cancer cells, suggesting therapeutic strategies. We previously identified an ATR (ataxia telangiectasia and Rad3-related)/ALK inhibitor (ATRi/ALKi) combination as such a strategy in two independent genetically modified mouse NB models. Here, we identify an underlying molecular mechanism, in which ALK signaling leads to phosphorylation of ATR and CHK1, supporting an effective DNA damage response. The importance of ALK inhibition is supported by mouse data, in which ATRi monotreatment resulted in a robust initial response, but subsequent relapse, in contrast to a 14-d ALKi/ATRi combination treatment that resulted in a robust and sustained response. Finally, we show that the remarkable response to the 14-d combined ATR/ALK inhibition protocol reflects a robust differentiation response, reprogramming tumor cells to a neuronal/Schwann cell lineage identity. Our results identify an ability of ATR inhibition to promote NB differentiation and underscore the importance of further exploring combined ALK/ATR inhibition in NB, particularly in high-risk patient groups with oncogene-induced replication stress.
Simple tracking of occluded self-propelled organisms
Authors: Noto Daisuke , Ulloa Hugo N
Published: December 2023

Deepening our understanding of animals’ collective motions represents a multidisciplinary goal. Yet, quantifying the motions of hundreds of animals in the laboratory and nature posits a fundamental challenge for digital image processing: How do we track each object out of the crowd while allowing them to move freely in a three-dimensional (3D) domain? Here, we present a simple tracking strategy to reconstruct 3D trajectories with the aid of a mirror, even if moving objects experience occlusion. We explain the method using synthetically generated datasets and apply it to measure collective motions of phototactic zooplankton, Daphnia magna, swimming in a lab-scale aquarium at intermediate Reynolds numbers,

1
<
R
e
<
13

. The method enables measuring statistics of characteristic features of D. magna swarm, including sinking velocities and flapping frequencies. Beyond the lab-scale animal tracking, we foresee further implementations of the method to study wild animals freely behaving in 3D environments irrespective of their species.
A novel unmanned aerial vehicle path planning approach: sand cat optimization algorithm incorporating learned behaviour
Authors: Hu Kun , Mo Yuanbin
Published: December 2023

Unmanned aerial vehicle (UAV) path planning plays an important role in UAV flight, and an effective algorithm is needed to realize UAV path planning. The sand cat algorithm is characterized by simple parameter setting and easy implementation. However, the convergence speed is slow, easy to fall into the local optimum. In order to solve these problems, a novel sand cat algorithm incorporating learning behaviors (LSCSO) is proposed. LSCSO is inspired by the life habits and learning ability of sand cats and incorporates a new position update strategy into the basic Sand Cat Optimization Algorithm, which maintains the diversity of the population and improves the convergence ability during the optimization process. Finally, LSCSO is applied to the challenging UAV 3D path planning with cubic B-spline interpolation to generate a smooth path, and the proposed algorithm is compared with a variety of other competing algorithms. The experimental results show that LSCSO has excellent optimization-seeking ability and plans a safe and feasible path with minimal cost consideration among all the compared algorithms.
AIR-CNN: a lightweight automatic image rectification CNN used for barrel distortion
Authors: Zhou Can , Zhou Canzong , Zhu Hongqiu , Liu Tianhao
Published: December 2023

Barrel distortions often exist in images captured by wide-angle lenses, and the presence of barrel distortions reduces the label-making accuracy of algorithms and the precision rate of final target detection and semantic recognition. To reduce the interference of barrel distortions on imaging, we have proposed a lightweight image rectification network automatic image rectification CNN (AIR-CNN) for barrel distortion. The network is based on a parameter sharing (PS) convolutional neural network structure, which is trained on the distorted image dataset to predict the pixel displacement field between the distorted image and the rectified image, and finally restores the rectified image based on the predicted pixel displacement field. The experimental results show that the AIR-CNN can greatly reduce the number of network parameters through the PS mechanism and implicitly learns the texture features by asymmetric convolution kernels to obtain higher rectification accuracy at a lower computational cost, and automatically obtain the distortion parameters of the camera without special calibration methods. The AIR-CNN outperforms previous image rectification methods in both intuitive and quantitative comparisons (EPE, PSNR, NRMSE, SSIM).
A step-by-step parameter-adaptive FMD method and its application in fault diagnosis
Authors: Wang Xiangrong , Li Congming , Tian Hongying , Xiong Xiaoyan
Published: December 2023

A newly proposed method, feature mode decomposition (FMD), can effectively enhance signal features while decomposing the signal. This feature is beneficial for analyzing weak vibration signals. However, the input parameters (the segment number K, the filter length L, and the mode number n,) significantly influence the decomposition performance and efficiency. Based on the analysis of filter properties and decomposition performance of the FMD method, a step-by-step parameter-adaptive FMD method is proposed. First, parameters K and L are optimized; second, the parameter n is determined. In addition, a comprehensive evaluation indicator, the ratio of sample entropy and ensemble kurtosis, is constructed considering both the periodic impact characteristics of fault signals and the noise intensity to create objective functions for each step. Compared with the methods of variational mode decomposition spectral kurtosis method and the wavelet packet decomposition, the proposed method exhibits better decomposition performance: the amplitude has increased by nearly ten times for the simulation data and six times for the actual engineering data, and three evaluation factors (the crest factor, the impulse factor, and the kurtosis) have higher value. Therefore, it can be concluded that the proposed method has better superiority in identifying weak periodic fault features.
Multi visual images fusion approach for metro tunnel defects based on saliency optimization of pixel level defect image features
Authors: Qiu Dongwei , Zhu Zhengkun , Wang Xingyu , Ding Keliang , Wang Zhaowei , Shi Yida , Niu Wenyue , Wan Shanshan
Published: December 2023

The multi-vision defect sensing system, lining composed primarily of IRT and RGB cameras, allows for automatic identification and extraction of small surface ailments, greatly enhancing detection efficiency. However, the presence of various issues like train vibration, inconsistent lighting, fluctuations in temperature and humidity leads to the images showing inadequate uniformity in illumination, blurriness, and a decrease in the level of detail. The above issues have led to unsatisfactory fusion processing results for multiple visual images and increased missed detection rates. To address the above-mentioned issue, multi visual images fusion approach for subway tunnel defects based on saliency optimization of pixel level defect image features is proposed. The approach initially analyses the train’s motion status and image blurring conditions. It then eliminates the dynamic blurring in the image. Secondly, Image weights are allocated based on the uniformity of visible light image illumination in the tunnel, as well as real-time temperature and humidity. Finally, image feature extraction and fusion are performed by a U-Net network that integrates channel attention mechanisms. The entire experiment was carried out on a dataset consisting of leakage data from the tunnel lining of Shanghai Metro and tunnel defect data from Beijing Metro. The experimental results demonstrate that this approach improves the image pixel value variation rate by 39.7%, enhances the edge quality by 23%, and outperforms similar approach in terms of average gradient, gradient quality, and sum of difference correlation with improvements of 15.9%, 7.3%, and 26.6% respectively.
Shortcut-based generation of transmon-magnon entangled states
Authors: Yan Run-Ying , Feng Zhi-Bo
Published: December 2023

Optimized generation of entangled states between solid-state qubits is of fundamental significance to quantum information science and technology. Here, we develop an effective scheme to fast and robustly create the entangled states in a hybrid system containing a superconducting transmon qubit and a spin magnon of yttrium iron garnet. The transmon qubit and the magnon system are coupled via a microwave cavity field. Within the framework of invariant-based shortcuts to adiabaticity, the transmon-magnon entangled states can be rapidly induced by engineering the Rabi couplings between the cavity mode and transmon (magnon) with constant amplitudes. Compared with a non-shortcut counterpart, the shortcut-based operations of interest not only considerably shorten the generation time, but also greatly mitigate the decoherence effects. Furthermore, the fast dynamics is well insensitive to the control deviation of Rabi couplings. Thus our approach could lead to advances in information processing and state engineering with composite systems.
Chaos control and exceptional point engineering via dissipative optomechanical coupling
Authors: Mbokop Tchounda S R , Djorwé P , Tchakui M V , Nana Engo S G
Published: December 2023

We study a dissipative mechanically coupled optomechanical system that hosts gain and loss. The gain (loss) is engineered by driving a purely dispersive optomechanical cavity with a blue-detuned (red-detuned) electromagnetic field. By taking into account the dissipative coupling, the Exceptional Point (EP), which is a non-Hermitain degeneracy, occurs at low threshold driving strength compared to what happens in a solely dispersive system. In the linear regime, the dissipative term induces strong coupling between the mechanical resonators, leading to an increase of energy exchange. For strong enough driving, the system enters into a nonlinear regime where a weak coupling regime takes place. In this regime, the mechanical resonators exhibit chaotic beats like-behaviour in the purely dispersive system. By switching on the dissipative coupling, the complex dynamics is switched off, and this restores regular dynamics into the system. This work suggests a way to probe quantum phenomena in dissipative systems at low-threshold driving strength. It also provides a new control scheme of complex dynamics in optomechanics and related fields.
Experimental study on the influence of gas flow rate on the plasma plume of N-APPJ
Authors: Zhang Xingyu , Chen Lei , Guan Tingyu , Wang Baohuai , Wang Shiang , Yang Huiyu , Song Peng
Published: December 2023

In order to explore the effect of the gas flow rate on the plasma plume, a quantitative study of the effect of the gas flow rate on the atmospheric pressure non-equilibrium plasma plume length was carried out using two different electrode structures. The results show that plasma plume length of up to 80.2 mm can be achieved in atmospheric condition outside the tube. The plasma plume length of the indented tube is smaller than that of the straight tube for the same argon gas flow rate, discharge voltage and axial distance between electrodes, and the effect of the argon flow rate on the plasma plume length is more obvious for the straight tube than for the indented tube. The plasma plume length of the straight-through tube tends to increase and then decrease as the argon flow rate increases, and the variation of the plasma plume length at an axial electrode distance of 0 mm is significantly greater than that of other electrode distance conditions. At the same argon flow rate, the maximum plasma plume length tends to increase and then decrease with the argon flow rate and increases with the axial distance of the electrodes.