bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of diverging angle on flame dynamics of near lean blowout in a centrally staged spray combustor
Authors: Han Meng , Xu Quanhong , Wang Jianchen , Han Xiao , Zheng Ke
Published: July 2024

This article focuses on the effect of diverging angle of the pilot stage on swirl spray flame dynamics near lean blowout conditions in a centrally staged lean premixed pre-vaporized combustor. The flame OH* chemiluminescence images, non-reactive flow fields, and spray fields of three diverging angles, P28°, P52°, and P90°, are obtained under elevated temperature and pressure conditions. Results show that the swirl jet angle of the pilot stage and primary recirculation zone increases with increase in the diverging angle. The spray angle also increases with increase in the diverging angle. There are pretty much more droplets distributed downstream of the pilot stage throat in P28°, which is different from the other two cases. The time-averaged flame shapes show that the flame shortens and the stabilized zone changes from the lip recirculation zone and inner shear layer to the central shear layer, as the equivalent ratio of the pilot stage (φp) decreases. The flame axial length decreases with increase in the diverging angle for φp below 2.0. Dynamic mode decomposition is applied to analyze the flame dynamics. The results indicate better hydrodynamic stability near lean blowout conditions at P90°. A bifurcation of characteristic frequency at P28° with decrease in φp indicates that the dominant mode of hydrodynamics instability changes from spiral to vortex shedding. Meanwhile, P52° is always the spiral mode with a higher frequency. These results could help understand the flame dynamics of different diverging angles near lean blowout conditions.
Effect of multiple Görtler vortices on roughness-induced transition in a high-speed boundary layer
Authors: Yu Min
Published: July 2024

The impact of Görtler vortices on roughness-induced transition in a Mach 6 concave hypersonic boundary layer is examined through implicit large eddy simulation. Our prior numerical investigations indicated that the evolution of the most amplified Görtler vortices appeared to have minimal influence on the process of roughness-induced transition within a hypersonic boundary layer. In this study, we conduct a comprehensive analysis of the effects of Görtler vortices on roughness-induced transition by simulating various roughness locations, dimensions, and multiple Görtler vortices. In hypersonic flows, the trapped layer Görtler mode is predominant; however, the most amplified Görtler vortices exhibit negligible influence on roughness-induced vortices, regardless of whether the roughness location or dimension is altered. This behavior contrasts sharply with that observed in other Görtler vortices. Amplified Görtler vortices with a wavelength twice that of the most amplified Görtler vortices significantly affect roughness-induced vortices and delay the transition process. It appears that distinct Görtler vortices exert varying degrees of influence on roughness-induced transition.
Flow interference investigation of multi-square prisms under fluid–structure interaction. II. Flow field phenomenology of side-by-side square prisms
Authors: Chen Zengshun , Guan Tengda , Zhang Likai , Li Sunwei , Kim Bubryur , Xu Yemeng , Fu Yunfei , Li Cruz Y.
Published: July 2024

The current research primarily focuses on interference effects in rigid structures, with the omission of the feedback impact of structural vibration on the flow field preventing the disclosure of the intrinsic mechanisms behind interference effects. Therefore, this study analyzed the aerodynamic characteristics and flow field phenomena of the finite-length side-by-side square prisms under vibration through the large eddy simulation, unveiling the flow field morphology and disturbance mechanisms. The results show that the three-dimensional effect of the side-by-side square prisms effectively suppresses the deflection of the gap flow. Structural vibration increases the curvature of the shear layers on both sides of the interfering structure, weakens its end effect, and destroys the integrity of the axial vortex in the wake region. With the increase in the spacing between the side-by-side square prisms, the “narrow pipe effect” is weakened, the flow acceleration is relatively slowed down, and interference of the vortices in the wake region is weakened. In addition, some typical flow field phenomena are observed, such as gap flow instability, coupled vortex street, interaction of wakes, and different flow regimes. This study is of great significance for understanding mechanisms of the flow interference around the finite-length side-by-side square prisms under fluid–structure interaction.
Experimental investigation on pore characteristics of heterogenous coal structures reservoir and coalbed methane diffusion/seepage behaviors
Authors: Zhang Kun , Jin Yi , Meng Zhaoping , Wang Xiaoming , Li Ming
Published: July 2024

Coalbed methane (CBM) reservoir mass transfer performances, including adsorption/desorption, diffusion and seepage, are related to the types of intact and cataclastic coal structures. By “cataclastic coal,” we mean that coal produces fractures in different directions caused by tectonic stress and is divided into fragments along the fractures surface, but there is no significant displacement between fragments. This paper sampled coal specimens from a coal mine to investigate the dynamic behaviors of reservoir by using experiments and Lattice Boltzmann Simulation Method (LBM). The results show that Langmuir VL, specific surface areas, and pore volumes occurring at cataclastic coal seam (570–572 m) are higher than in intact coals. The dominant pore size in samples 1, 2, 3, and 4 is distributed between 2 and 10 nm, leading to increased adsorption capacity in cataclastic coal. Cataclastic coals' fractal dimension D1 is higher than in intact coal, but D2 is lower than in intact coal, which means tectonic damage causes the pore surface to become coarser and the pore structures to become homogenous. Because of increased pore volume in cataclastic coal, its dynamic diffusion coefficient is better than in intact coal, meaning the upper coal seam has beneficial gas releasing efficiency. Based on LBM simulation and tri-axial permeability experiments, it is found that cataclastic coal with developed natural fractures is characterized by high velocity of fluids, but its damage ratio of permeability is stronger than in intact coal. Finally, it summarizes the reservoir characters of Gaohe coal field and proposes that it should pay attention on the lower intact coal seam for the stimulation of CBM reservoir.
A closer look at the effects of oxygen on the photoluminescence properties of CdSe/CdS quantum dots
Authors: Kusterer Roman , Krohn Sonja , Wehrmeister Moritz , Strelow Christian , Kipp Tobias , Mews Alf
Published: July 2024

We present a detailed study on the effects of oxygen on the photoluminescence properties of CdSe/CdS quantum dots (QDs). We investigated the role of oxygen by performing confocal measurements on thin films as well as on single particles while rapidly exchanging the gaseous environment between oxygen and an inert gas atmosphere. We found that the deionization of negatively charged particles by oxygen depends on both the excitation power and the shell thickness of the QDs. For QDs with thin shells, which exhibit strong photoluminescence blinking, we observed that the presence of oxygen affects both band-edge carrier blinking and hot-carrier blinking.
Heat and mass transfer performance of low Reynolds number flow behind a cylinder connecting with an L-shaped flexible body within a microchannel
Authors: Hu Enkai , Li Yan , Chen Feihao , Jing Dalei
Published: July 2024

In order to enhance the heat and mass transfer performance of laminar flow within a microchannel at a low Reynolds number, this paper introduces an asymmetric structure of an L-shaped flexible body connecting to a cylinder into the microchannel and studies the effects of the geometric dimensions of the L-shaped flexible body on the flow pattern transition and the heat and mass transfer performance, including the pressure loss, the Nusselt number, and the outlet mixing efficiency. It is found that by means of an asymmetric structure of the L-shaped flexible body connecting to the cylinder, the flow pattern transitions from laminar flow to vortex flow at a low Reynolds number based on the diameter of the cylinder of Red = 25. The transition of the flow patterns induced by an asymmetric L-shaped flexible body enhances the thermal and mixing performance of the fluid flow within the microchannel. Both the Nusselt number and the outlet mixing efficiency significantly increase under the influence of the L-shaped flexible body compared to the case with a single cylinder, and they increase with the increasing length of the vertical part of the L-shaped flexible body. The findings in the present work provide a new strategy to enhance the heat and mass transfer performance of low-Reynolds-number fluid flow within a microchannel by using the interaction of an asymmetric flexible body with the fluid flow behind a bluff body.
Robust cellulose-BaTiO3 separator with electric-field regulation effect for dendrite-free Zn-ion batteries
Authors: Zhang He , Qiu Meijia , Liang Yuxuan , Chen Jinguo , Liu Yongtao , Pu Xiong , Mai Wenjie , Sun Peng
Published: July 2024

Aqueous Zn-ion batteries have emerged as one of the best candidates for efficient and safe energy storage systems; however, they are severely restricted by the formation of uncontrolled Zn dendrites. To address this issue, micro-fibrillated cellulose (MFC)-BaTiO3 separators are designed to regulate the Zn2+ transport behavior and achieve stable Zn anodes via coupling multiple effects. The MFC component offers a cellulose framework with robust mechanical properties and prior ion transfer channels, while the BaTiO3 particles provide dynamic electric-field regulation toward Zn2+ transfer process under different states. Due to the above-mentioned co-functions, MFC-BaTiO3 separators deliver a much better comprehensive performance than the commercial glass fiber (GF) separator. A higher Zn2+ transference number of 0.69 can be achieved in the composite separator, which is more than twice that of the GF separator. Therefore, the MFC-BaTiO3 separators are capable of achieving a much longer cycle life of more than 1050 h under 1 mA cm−2 and 1 mAh cm−2 in contrast to only 250 h observed with GF separators. Corresponding Zn//Cu cells presented a considerable Coulombic efficiency of 99.1%, and Zn//MnO2 full cells can stably work for over 500 cycles. This work provides deep insights into designing efficient, high-performance, and low-cost separators for aqueous batteries.
Suppression of positive bias instability by inserting polarized AlN interlayer at AlSiO/p-type GaN interface in metal–oxide–semiconductor field-effect transistor
Authors: Iguchi Hiroko , Narita Tetsuo , Ito Kenji , Iwasaki Shiro , Kano Emi , Ikarashi Nobuyuki , Tomita Kazuyoshi , Kikuta Daigo
Published: July 2024

Bias instability is a critical issue for metal–oxide–semiconductor field-effect transistors (MOSFETs). This study demonstrates suppression of the positive bias instability of the threshold voltage (Vth) in a GaN MOSFET by insertion of a thin crystalline AlN interlayer (AlN-IL) formed by plasma-enhanced atomic layer deposition. The gate stacks were composed of an AlSiO/AlN/p-type GaN structure having a high channel mobility of greater than 170 cm2 V−1 s−1. When the AlN-IL was inserted, the Vth shift under an oxide electric field of 3.9 MV cm−1 was strongly suppressed from 0.72 V to less than 0.12 V. This suppression was attributed to an increase in the effective barrier height associated with oxide traps in the AlSiO for inversion channel electrons as a result of the insertion of the polarized AlN-IL. The key to this approach is adequate control of the AlN-IL thickness. The insertion of a 0.8-nm-thick AlN-IL led to a low interface state density (Dit) and a minimized positive bias instability, whereas an AlN-IL thicker than 2.3 nm led to an increase in both Dit and a Vth shift. The effective barrier height should increase with increasing AlN thickness; however, an increase in a Vth shift instead occurred. This indicates that defects that capture electrons are additionally introduced when the thickness of the AlN-IL on GaN layers exceeds the critical thickness. The results clearly suggest that Vth instability can be minimized by controlling the thickness of a thin AlN-IL deposited at an AlSiO/p-type GaN interface and simultaneously providing high channel mobility.
Impact of free-stream orientation and thermal buoyancy on aerodynamic and heat transfer characteristics in mixed convective flow past an elliptical cylinder
Authors: Garg Ashish , Arif Md. Reyaz , Hasan Nadeem
Published: July 2024

This study conducts a thorough numerical investigation into the aerodynamic and heat transfer characteristics of mixed convective flow past an elliptical cylinder. Analysis is carried out for a constant Reynolds number (Re = 100), a Prandtl number (Pr = 0.71), and an angle of attack (λ=0°), utilizing the Oberbeck–Boussinesq approximation to solve mass, momentum, and energy equations via an in-house numerical solver. It explores a wide range of free-stream orientations, from 0° (upward flow aligned with gravity) to 90° (cross-flow). Additionally, Richardson number (Ri) is varied from forced convection (Ri = 0) to mixed convection regimes, up to Ri = 1.25. Two aspect ratios (AR=Major axis length/Minor axis length), specifically 2 and 4, are examined to assess their impact on flow behavior. The paper elucidates variations of lift coefficient, drag coefficient, and Nusselt number with Ri at different free-stream orientations. Furthermore, it investigates dynamics of both steady and unsteady flow regimes, correlating flow behavior with observed aerodynamic and heat transfer characteristics. Steady and unsteady periodic flow regimes are identified in the parametric space of (α, Ri) for AR = 2 and 4. The mean heat transfer rate increases with Ri in both steady and unsteady flow regimes at (α=0°, 30°, and 60°) for AR = 2 and 4, except at α=90°, where it decreases. These findings provide insights for designing compact heat exchangers utilizing elliptic tube cross-sections.
Numerical and experimental investigations of flow features over a wedge exposed to supersonic flow at high Reynolds numbers
Authors: Cakir B. O. , Grossir G. , Saracoglu B. , Fureby C.
Published: July 2024

Numerical simulation tools and experimental measurement techniques are required to provide accurate description of flow features in application relevant scales and boundary conditions enroute to realizing the design and integration of high-speed arial platforms. A case of 10° wedge exposed to Mach 3.5 supersonic flow at high Reynolds numbers provides an opportunity to conduct a comparative analysis between the numerical and experimental tools that are suitable for investigation of application relevant scales. Due to its superior scalability and the recently advanced sensitivity and resolution range, background oriented schlieren is utilized to provide non-intrusive quantification of density varying flow features. On the other hand, the numerical simulations are performed by means of two main turbulence treatment schemes of Reynolds averaged Navier–Stokes (RANS) and large eddy simulations (LES) employing k–ω shear stress transport turbulence and localized dynamic k-equation sub-grid scale models, respectively. Although the lower computational cost of RANS is referred to as an advantage over LES in large scale simulations, the accuracy deficit is discussed in terms of establishing an acceptable trade-off. Accordingly, physical orientations and intensities of the captured flow features and the respective physical, optical, and numerical features driven by the specifications of the experimental and numerical configurations and their impact on the description of relevant flow features are detailed.
High repetition-rate dual-channel X-ray spectrometer for high-intensity laser-plasma experiments
Authors: Zeraouli G. , Mariscal D. A. , Swanson K. K. , Grace E. , Folsom E. N. , Hill M. P. , Williams G. J. , Simpson R. A. , Djordjevic B. Z. , Daskalova R. , Tiscareno G. , Hanggi D. , Spingola P. , Unzicker B. , Kuz C. , Andrews S. , Costa R. , Cauble B. , Albert F. , Schumacher D. W. , Rocca J. J. , Ma T.
Published: July 2024

We describe the development and demonstration of a high-repetition-rate-capable dual-channel (DC) x-ray spectrometer designed for high-intensity laser–plasma experiments (≥1×1021 W/cm2). The spectrometer, which operates at high repetition rates, is limited only by the refresh rate of targets and the camera’s frame rate. It features two channels, each equipped with a flat highly oriented pyrolytic graphite (HOPG) crystal and a unique detector plane, allowing it to resolve two distinct x-ray bands: approximately 7–10 and 10–13 keV. Each detector plate carrier holds two slots for active (scintillators) or passive (imaging plates) x-ray detectors. We present the design and testing of the HR-DC-HOPG using both the COMET laser (10 J, 0.5 ps shot/4 min) at LLNL’s Jupiter Laser Facility and the SCARLET laser (10 J, 30 fs shot/min) at Ohio State University. The results demonstrate the spectrometer’s performance across various laser energies, target materials, pulse shapes, and detector types.
Nanopore tweezers show fractional-nucleotide translocation in sequence-dependent pausing by RNA polymerase
Authors: Nova Ian C. , Craig Jonathan M. , Mazumder Abhishek , Laszlo Andrew H. , Derrington Ian M. , Noakes Matthew T. , Brinkerhoff Henry , Yang Shuya , Vahedian-Movahed Hanif , Li Lingting , Zhang Yu , Bowman Jasmine L. , Huang Jesse R. , Mount Jonathan W. , Ebright Richard H. , Gundlach Jens H.
Published: July 2024

RNA polymerases (RNAPs) carry out the first step in the central dogma of molecular biology by transcribing DNA into RNA. Despite their importance, much about how RNAPs work remains unclear, in part because the small (3.4 Angstrom) and fast (~40 ms/nt) steps during transcription were difficult to resolve. Here, we used high-resolution nanopore tweezers to observe the motion of single
Escherichia coli
RNAP molecules as it transcribes DNA ~1,000 times improved temporal resolution, resolving single-nucleotide and fractional-nucleotide steps of individual RNAPs at saturating nucleoside triphosphate concentrations. We analyzed RNAP during processive transcription elongation and sequence-dependent pausing at the
yrbL
elemental pause sequence. Each time RNAP encounters the
yrbL
elemental pause sequence, it rapidly interconverts between five translocational states, residing predominantly in a half-translocated state. The kinetics and force-dependence of this half-translocated state indicate it is a functional intermediate between pre- and post-translocated states. Using structural and kinetics data, we show that, in the half-translocated and post-translocated states, sequence-specific protein–DNA interaction occurs between RNAP and a guanine base at the downstream end of the transcription bubble (core recognition element). Kinetic data show that this interaction stabilizes the half-translocated and post-translocated states relative to the pre-translocated state. We develop a kinetic model for RNAP at the
yrbL
pause and discuss this in the context of key structural features.
Large-scale synthesis of defect-free phosphorene on nickel substrates: enabling atomistic thickness devices
Authors: Tchoffo D B Talonpa , Benabdallah I , Aberda A , Neugebauer P , Belhboub A , El Fatimy A
Published: July 2024

Addressing the main challenges of defect-free, large-scale synthesis of low-dimensional materials composed of phosphorus atoms is essential for advancing promising phosphorene-based technologies. Using molecular dynamics simulation, we demonstrate the large-scale and defect-free synthesis of phosphorene on Nickel (Ni) substrates. We showed that substrate orientation is crucial in the controllable synthesis of different phosphorene allotropes. Specifically, blue phosphorene was successfully grown on Ni (111) and Ni (100) surfaces, while γ-phosphorene, referred to here as Navy phosphorene, was grown on Ni (110). In addition, temperature control (high temperature) and cooling rate (slow cooling) are also crucial in the formation of P6 hexagons. Finally, we report that the phosphorus pentamers (P5) are the essential precursor for phosphorene synthesis. This work provides a robust framework for understanding and controlling the synthesis of large-area, single-crystalline monolayer phosphorene.
The effect of temperature oscillations on energy storage rectification in harmonic systems
Authors: Chen Renai , Craven Galen T
Published: July 2024

Rectification, the preferential transport of a current in one direction through a system, has garnered significant attention in molecules because of its importance for controlling thermal and electronic currents at the nanoscale. Here, we report the presence of energy storage rectification effects in a molecular chain. This phenomenon is generated by subjecting a harmonic molecular chain to an oscillating temperature gradient and showing that the energy absorption rate of the system depends on the direction of the gradient. We examine how the energy storage rectification ratios in the chain are affected by the oscillating gradient, asymmetry in the chain, and the system parameters. We find that energy storage rectification can be observed in harmonic lattice structures with time-dependent temperatures and that, correspondingly, anharmonicity is not required to generate this rectification mechanism in such systems.
Novel 4D-printing pellets with infrared-light responsive shape memory effect
Authors: Chen Shaojun , Mao Xianhao , He Zhen , Lu Wei , Wu Bing , Zhuo Haitao
Published: July 2024

Four-dimensional (4D)-printing technology is attractive to researchers since it combines 3D printing with smart materials to produce 3D structures with various shapes and change shapes under specific external stimuli. Herein, novel shape memory polymer (SMP) pellets with infrared-light responsive shape memory effect were developed for 4D printing applications. The structures, properties, and infrared-light responsive shape memory performances of the resulting (SMP) pellets were thoroughly investigated. The results showed PDA/SMP pellets prepared by direct loading of polydopamine (PDA) particles on SMP pellets displayed less influence on the basic properties of SMP while fluidity was enhanced. The obtained PDA/SMP pellets employed as feed materials for particle 3D printers revealed good thermal-induced shape memory performance and photo-responsive shape memory performance in printed 3D structures. Under infrared-light irradiation, the curled shape recovered to straight splines within 60 s due to the strong absorption and good photo-thermal conversion of the loaded PDA nanoparticles under infrared light. Overall, the as-prepared PDA/SMP pellets look promising for use in biomedical fields and smart devices, as well as remote control deformation with 4D printing technology.
Shear response of 〈110〉 asymmetric tilt grain boundaries in BCC-Fe
Authors: Veerababu J , Nagesha A , Shankar Vani
Published: July 2024

The present study investigated the effect of shear load on the

110

asymmetric tilt grain boundaries of body-centered cubic iron with molecular dynamics simulations. Various mechanisms like grain boundary (GB) sliding, shear-coupled migration, GB migration with rotation, GB decomposition, and GB deformation with dislocations emission were observed. Low-angle tilt GBs migrated with the help of two dislocation mechanisms, gliding and climbing. Two types of twin nucleation mechanisms were noticed in high-angle tilt GBs with varying tilt angles (η). For 16° ≤ η ≤ 112° and η ≥ 130° cases, dynamic self-adjustment of the atoms at the GBs caused GBs decomposition with the formation of twin boundaries (TBs). Newly nucleated TBs migrated under further applied shear load. For 112° < η < 130° case, TBs nucleated from the GB on either side of the misfit dislocations due to their localized core structure on the GB plane.
Effect of hydrogen treatment on 4H-SiC Schottky barrier diodes
Authors: Chen Zihe , Liu Ling , Sun Yunlong , Li Gang , Yan Shaoan , Xiao Yongguang , Tang Minghua , Li Zheng
Published: July 2024

In this letter, 4H-SiC Schottky barrier diodes (SBDs) with Ti Schottky metal have been subjected to hydrogen treatment in a confined environment of 4% H2 and 96% N2 at 150 °C. The effect of hydrogen treatment on the SBDs electrical characteristics has been investigated by technical computer-aided design simulation (TCAD) and power device analyzer curve tracer. The change of electrical parameters of SBDs measured after hydrogen treatment is studied in detail, and the related degradation mechanism is discussed. It was found that hydrogen treatment affected both the interface region and bulk region of SiC SBDs. After hydrogen treatment, the Schottky barrier increases slightly, the ideal factor (n) decreases slightly, and the interfacial state density (D
it) decreases. Hydrogen treatment resulted in a slight reduction in specific on-resistance (R
on-sp), which was attributed to the diffusion of H in SBDs. Through TCAD simulation, it is determined that the diffusion of H in the body diode of SBDs is the main reason for the degradation of high forward current and high reverse voltage characteristics.
Spurious negative eigenvalues of numerical variance-covariance matrices in many-body systems correlate with the existence of frozen degrees of freedom
Authors: Hungerland Jonathan , Solov’yov Ilia A , Schuhmann Fabian
Published: July 2024

The principal component analysis (PCA) is widely used to reduce the dimensionality of a dataset to its essential components. To perform PCA, the covariance matrix is constructed and its eigenvalues and eigenvectors are computed. In practical numerical applications, the tail of the sorted eigenvalues is sometimes found to contain negative eigenvalues, which are prohibited mathematically and are a pure consequence of finite-accuracy numerics. The present study suggests that in the case of a many-body dynamical system, the spurious negative eigenvalues of the covariance matrix may in fact be related to the frozen degrees of freedom in the system. Here, we outline the mathematical connection between the eigenvalues of the covariance matrix and the frozen degrees of freedom and validate the connection through two case studies: a model system of coupled harmonic oscillators and a molecular dynamics simulation of a small protein in solution.
Quantum teleportation of shared high-dimensional quantum secret
Authors: Peng Jiayin , Maihemuti Nueraminaimu , Aisan Yimamujiang , Yang Zhen
Published: July 2024

We present an innovative approach for quantum teleportation (QT) in a three-dimensional (3D) quantum system, enabling the transmission of 3D quantum information from multiple senders to multiple receivers using a 3D maximally entangled GHZ-type state as a network channel.By substituting the quantum channel with a partially entangled GHZ-type state in a three-dimensional (3D) setting, we obtain an extension of the above scheme in which, when an auxiliary qubit is introduced, the receivers implement a two-particle unitary transformation and some proper 3D Weyl operators to jointly reconstruct the transmitted state with a certain probability and unit fidelity. Subsequently, inspired by the proposed schemes, a protocol for transferring a shared d-dimensional (dD) quantum state to multiple distant parties by using a dD maximally entangled GHZ-type state as quantum channel is presented, and it is generalized to the case of a dD partially entangled GHZ-type network channel by introducing an auxiliary qubit and executing a two-particle unitary transformation. Our schemes can relay quantum information over a network without requiring fully trusted central or intermediate nodes, and none of the participants can fully accesses the information.
Temperature-induced activation and reversal of the relativistic ratchet currents on a graphene chip model
Authors: Manchein Cesar , Oliveira Tulio M , Rost Jan-Michael , Beims Marcus W
Published: July 2024

We investigate a monolayer graphene chip’s relativistic ratchet current (RRC). Our findings indicate that thermal noise can paradoxically amplify the RRC, in contrast to its conventional inhibitory role. Under noise, temperature (T) activation of the RRC remains stable over a broader range of T values, and an increased number of RRCs reversals are observed as a function of T and relevant parameters of the external electric field. The results regarding structural changes and symmetry breaking of the dissipative attractors can be understood. The observed activation and reversal of RRCs under a variation of external parameters unveil the diverse and complex behavior of the charge carrier transport on the graphene chip. Understanding this behavior allows for generating specific RRCs values, properties and effects for the charge carriers, offering a variety of possibilities for application and control of the graphene chip device.
Exploring existence, uniqueness, and stability in nonlinear fractional boundary value problems with three-point boundary conditions
Authors: Poovarasan R , Abdeljawad Thabet , Govindaraj V
Published: July 2024

This study investigates the analysis of the existence, uniqueness, and stability of solutions for a Ψ-Caputo three-point nonlinear fractional boundary value problem using the Banach contraction principle and Sadovskii’s fixed point theorem. We demonstrate the practical implications of our analytical advancements for each situation, illustrating how the components of the fractional boundary value problem emerge in real-life occurrences. Our work significantly enhances the field of applied mathematics by offering analytical solutions and valuable insights.
Clinical and diagnostic implications of Alzheimer's disease copathology in Lewy body disease
Authors: Barba Lorenzo , Abu-Rumeileh Samir , Barthel Henryk , Massa Federico , Foschi Matteo , Bellomo Giovanni , Gaetani Lorenzo , Thal Dietmar R , Parnetti Lucilla , Otto Markus
Published: July 2024

Concomitant Alzheimer's disease (AD) pathology is a frequent event in the context of Lewy body disease (LBD), occurring in approximately half of all cases. Evidence shows that LBD patients with AD copathology show an accelerated disease course, a greater risk of cognitive decline and an overall poorer prognosis. However, LBD-AD cases may show heterogeneous motor and non-motor phenotypes with a higher risk of dementia and, consequently, be not rarely misdiagnosed.

In this review, we summarize the current understanding of LBD-AD by discussing the synergistic effects of AD neuropathological changes and Lewy pathology and their clinical relevance. Furthermore, we provide an extensive overview of neuroimaging and fluid biomarkers under assessment for use in LBD-AD and their possible diagnostic and prognostic values. AD pathology can be predicted in vivo by means of CSF, MRI and PET markers, whereas the most promising technique to date for identifying Lewy pathology in different biological tissues is the α-synuclein seed amplification assay. Pathological imaging and CSF AD biomarkers are associated with a higher likelihood of cognitive decline in LBD but do not always mirror the neuropathological severity as in pure AD. Implementing the use of blood-based AD biomarkers might allow faster screening of LBD patients for AD copathology, thus improving the overall diagnostic sensitivity for LBD-AD.

Finally, we discuss the literature on novel candidate biomarkers being exploited in LBD-AD to investigate other aspects of neurodegeneration, such as neuroaxonal injury, glial activation and synaptic dysfunction. The thorough characterization of AD copathology in LBD should be taken into account when considering differential diagnoses of dementia syndromes, to allow prognostic evaluation on an individual level, and to guide symptomatic and disease-modifying therapies.
Annexin A11 mutations are associated with nuclear envelope dysfunction in vivo and in human tissues
Authors: Marchica Valentina , Biasetti Luca , Barnard Jodi , Li Shujing , Nikolaou Nikolas , Frosch Matthew P , Lucente Diane E , Eldaief Mark , King Andrew , Fanto Manolis , Troakes Claire , Houart Corinne , Smith Bradley N
Published: July 2024

Annexin A11 mutations are a rare cause of amyotrophic lateral sclerosis (ALS), wherein replicated protein variants P36R, G38R, D40G and D40Y are located in a small helix within the long, disordered N-terminus. To elucidate disease mechanisms, we characterized the phenotypes induced by a genetic loss-of-function and by misexpression of G38R and D40G in vivo.

Loss of Annexin A11 results in a low-penetrant behavioural phenotype and aberrant axonal morphology in zebrafish homozygous knockout larvae, which is rescued by human wild-type Annexin A11. Both Annexin A11 knockout/down and ALS variants trigger nuclear dysfunction characterized by Lamin B2 mislocalization. The Lamin B2 signature also presented in anterior horn, spinal cord neurons from post-mortem ALS ± frontotemporal dementia patient tissue possessing G38R and D40G protein variants.

These findings suggest mutant Annexin A11 acts as a dominant negative, revealing a potential early nucleopathy highlighting nuclear envelope abnormalities preceding behavioural abnormality in animal models.
An explicit Maclaurin series solution to non-autonomous and non-homogeneous evolution equation, Omega Calculus and associated applications
Authors: Francisco Neto Antônio
Published: July 2024

We give a new Omega Calculus (a.k.a MacMahon’s Partition Analysis) based integral-free representation for the solution of a non-autonomous and non-homogeneous evolution equation. Our new representation generalizes some of the main results of the recent work of Francisco Neto (2024, A basis- and integral-free representation of time-dependent perturbation theory via the Omega matrix calculus. Ann. Inst. Henri Poincaré D, 11, 383) and Bassom et al. (2023, An explicit Maclaurin series solution to a classic non-autonomous abstract evolution equation. Appl. Math. Lett., 139, 108537) and show that we can indeed compute the coefficients of the Maclaurin series solution associated with the evolution equation starting with the Peano–Baker series. Furthermore, we discuss in the context of our framework the inverse problem for homogeneous evolution equations in a Hilbert space answering a question left open by Bassom et al. in this case; i.e. assuming the solution of the homogeneous evolution equation is a known analytic function the problem concerns the determination of the associated generator of the dynamics. Finally, in order to illustrate the versatility of our approach we explicitly determine the Maclaurin series solution related to the power series method in the context of the vibration problems for the non-uniform (tapered) Euler–Bernoulli beam and thus we explicitly solve the recursion relations considered by Adair and Jaeger (2018, A power series solution for rotating nonuniform Euler–Bernoulli cantilever beams. J. Vib. Control, 24, 3855–3864).
Formal and informal hospital emergency management practices: managing for safety and performance amid crisis
Authors: Hayirli Tuna Cem , Kuznetsova Masha , Biddinger Paul D , Bambury Elizabeth A , Atkinson Mariam Krikorian
Published: July 2024

Although formal preparedness for unexpected crises has long been a concern of health care policy and delivery, many hospitals struggled to manage staff and equipment shortages, precarious finances, and supply chain disruptions among other difficulties during the Coronavirus disease pandemic. Our purpose was to analyze how hospitals used formal and informal emergency management practices to maintain safe and high-quality care while responding to crisis. We conducted a qualitative study based on 26 interviews with hospital leaders and emergency managers from 12 US hospitals, purposively sampled to vary along geographic location, urban/rural delineation, size, resource availability, system membership, teaching status, and performance levels among other characteristics. In order to manage staff, space, supplies, and system- related challenges, hospitals engaged formal and informal practices around planning, teaming, and exchanging resources and information. Relying solely only on formal or informal practices proved inadequate, especially when prespecified plans, the incident command structure, and existing contracts and communication platforms failed to support resilient response. We identified emergent capabilities—imaginative planning, recombinant teaming, and transformational exchange—through which hospitals achieved harmonious interplay between the formal and informal practices of emergency management that supported safe care and resilience amid crisis. Managing emergent challenges for and amid crisis calls for health care delivery organizations to engage creative planning processes, enable motivated workers with diverse skill sets to team up, and establish rich inter- and intra-organizational partnerships that support vital exchange.
Non-literal lies are not exculpatory
Authors: Güngör Hüseyin
Published: July 2024

One can lie by asserting non-literal content. If I tell you ‘You are the cream in my coffee’ while hating you, I can be rightfully accused of lying if my true emotions are unearthed. This is not easy to accommodate under many definitions of lying while preserving the lying-misleading distinction. The essential feature of non-literal utterances is their falsity when literally construed. This interferes with accounts of lying and misleading, because such accounts often combine a literal construal of what is said by an utterance with a falsity requirement for lying. In the presence of non-literal lies, such definitions fail to make plausible predictions for non-literal lies and merely misleading utterances together. In this article, I aim to fix this by extending Daniel Hoek’s pragmatic account of conversational exculpature to assertions in general. Since this mechanism is designed to compute the intended meanings of non-literal utterances, it straightforwardly predicts non-literal lies to be as such. The lying-misleading distinction is also preserved, because merely misleading utterances arise out of exploiting a different pragmatic mechanism—Gricean additive implicatures. Along the way, I also draw some general lessons about assertion and implicatures.
Rib-on-Pelvis Deformity and Reported Pain in Neuromuscular Early-Onset Scoliosis
Authors: Desai Vineet M. , Bowen Margaret , Anari Jason B. , Flynn John M. , Brooks Jaysson T. , Snyder Brian , Ramo Brandon , Li Ying , Andras Lindsay M. , Truong Walter H. , Fitzgerald Ryan , El-Hawary Ron , Roye Benjamin , Yaszay Burt , Kwan Kenny Yat Hong , McIntosh Amy , Nelson Susan , Gupta Purnendu , Erickson Mark , Garg Sumeet ,   Pediatric Spine Study Group, Cahill Patrick J.
Published: July 2024

Background:

Neuromuscular early-onset scoliosis (N-EOS) often presents with a long sweeping thoracolumbar scoliosis and pelvic obliquity. With severe pelvic obliquity, the ribs come into contact with the high side of the pelvis, termed rib-on-pelvis deformity (ROP). The goal of this study is to evaluate whether ROP is associated with reported pain and other health-related quality of life (HRQOL) measures. We hypothesize that ROP is associated with increased pain and negative HRQOL.

Methods:

A multicenter international registry was queried for all nonambulatory patients with N-EOS from 2012 to 2022. Both surgical and nonsurgical patients were included. ROP was classified as a binary radiographic assessment of preoperative (surgical patients) and most recent follow-up (nonsurgical patients) upright radiographs. Reported pain and other HRQOL measures were assessed through the 24-Item Early Onset Scoliosis Questionnaire (EOSQ-24). Patients with nonupright radiographs or EOSQ-24 questionnaires and corresponding radiographs >4 months apart were excluded.

Results:

Totally, 225 patients (8.4±3.1 y, 55% female) were included. The median major curve was 63.3 (IQR: 40.6 to 81.2) degrees and median pelvic obliquity was 15.5 degrees (IQR: 8.8 to 26.4). Eighty-three patients (37%) had ROP. ROP was associated with both frequency (P<0.001) and severity (P<0.001) of pain. ROP was associated with worse general health (P=0.01), increased difficulty with vocalization (P=0.02), increased frequency of shortness of breath (P=0.002), and increased difficulty sitting upright (P=0.04). Regarding overall EOSQ-24 domains, ROP was associated with worse general health, pain/discomfort, pulmonary function, and physical function (P<0.01). In a subanalysis of 76 patients who underwent surgical intervention with at least 2 years of follow-up, patients with preoperative ROP experienced significantly greater improvements in both frequency (P=0.004) and severity (P=0.001) of pain than the patients without preoperative ROP at 2 years postoperatively.

Conclusions:

The overall incidence of ROP in N-EOS is about 37%. ROP is associated with greater pain and worse HRQOL through the EOSQ-24 questionnaire. Furthermore, these patients experienced a greater reduction in pain after surgery. Clinicians and parents must be aware that ROP is possibly a pain generator, but responds positively to surgical intervention.

Level of Evidence:

Level III.
Preoperative in-hospital delay increases postoperative morbidity and mortality in patients with acute appendicitis: a meta-analysis
Authors: Tang Gang , Zhang Linyu , Xia Lingying , Zhang Jie , Chen Rui , Zhou Rongxing
Published: July 2024

Background:

Complicated appendicitis is associated with high morbidity, mortality, and healthcare costs. However, the relationship of preoperative in-hospital delay >24 h with complicated appendicitis and postoperative morbidity remains unclear. This meta-analysis investigated the effects of preoperative in-hospital delay on complicated appendicitis and postoperative morbidity in patients with acute appendicitis.

Materials and methods:

This study adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR2) guidelines. The PubMed, Embase, Cochrane Library, and Web of Science databases up to October 14, 2023 (updated on March 16, 2024) were searched for randomized controlled trials and observational studies that evaluated the effect of preoperative in-hospital delays of >24 h on acute appendicitis. Odds ratios (OR) and 95% confidence intervals (CIs) were also determined.

Results:

We yielded 18 130 records, of which 28 studies (512 881 patients) were included in the meta-analysis. The risk of bias was considered serious, moderate, and low for 24, 3, and 1 study, respectively. Although preoperative in-hospital delays of >24 h were not associated with a higher risk of surgical-site infection (OR: 1.04, 95% CI: 0.97, 1.12, P=0.25), in-hospital delays of >24 h were a risk factor for complicated appendicitis (OR: 1.60, 95% CI: 1.25, 2.05, P=0.0002), and postoperative complications (OR: 1.51, 95% CI: 1.30, 1.75, P<0.00001). In addition, an in-hospital delay of >24 h before surgery increased the OR of postoperative mortality (OR: 1.81, 95% CI: 1.33, 2.45, P=0.0001). The sensitivity analyses also confirmed the robustness of our results.

Conclusions:

An in-hospital delay of >24 h is a risk factor for complicated appendicitis, postoperative complications, and mortality. Given the subsequent adverse outcomes of in-hospital delays, appendectomy should not be delayed for >24 h.
Development of a Standardized Nursing Handoff With Tablet Technology: A Quality Improvement Initiative
Authors: Miller Briana R. , Maye Kimberly A. , Charlton Frances D.
Published: July 2024

Background:

Nursing handoff of complete and accurate information is critical for patient safety yet is often difficult to achieve with consistency between nursing departments.

Objective:

This quality improvement project aims to describe the development and piloting of a standardized handoff tool for administration by computer tablet for nursing report.

Methods:

This descriptive quality improvement initiative was conducted in an 885-bed Level I trauma center in the Southeast Region of the United States. The study was completed in three phases. First, emergency department and trauma intensive care unit nurses were surveyed to determine handoff barriers and best practices. Second, the survey information was used to develop a standardized handoff tool incorporating tablet technology. Third, staff pilot testing was performed, followed by a final survey to ascertain staff feedback on the tool.

Results:

A total of n = 120 nurses completed the surveys, and pilot testing was conducted on n = 177 patient handoffs. Ninety-five percent of nurses expressed satisfaction with the tool and 65% with the tablet.

Conclusion:

This study supported using a standardized handoff tool between the emergency department and trauma intensive care unit and substantiated the benefits of using a tablet for face-to-face communication.
Leveraging AI technology in sarcoidosis
Authors: Premjee Akiff , Li Lawrence , Garikapati Srilakashmi , Sarpong Kwabena Nketiah , Morgenthau Adam S.
Published: July 2024

Purpose of review

Sarcoidosis is a systemic, granulomatous disease of uncertain cause. Diagnosis may be difficult, prognosis uncertain and response to treatment unpredictable. The application of artificial intelligence to sarcoidosis may provide clinical decision support for these challenges. This review will provide an overview of current and potential future applications of artificial intelligence in sarcoidosis.

Recent findings

The predominant application of artificial intelligence in sarcoidosis is imaging. Imaging models may differentiate sarcoidosis from other pulmonary disorders. Models, which predict survival and identify key factors relevant to prognosis are also available. The application of cluster analysis to organize sarcoidosis patients into developmental phenotypes is underway. Machine learning algorithms to evaluate the treatment response of sarcoidosis patients do not yet exist but similar models may evaluate patients with other inflammatory disease. The potential applications of artificial intelligence to sarcoidosis is vast, but there are practical limitations that warrant consideration. These include: the accessibility of data, biases in data, cost and privacy.

The application of artificial intelligence in medicine is still in its early stages but models are poised to support the diagnostic and prognostic challenges in sarcoidosis patients. The predictive power of these artificial intelligence is likely to come from combining various models, trained on content-rich datasets from phenotypically heterogeneous sarcoidosis patients.