bluuebunny/crossref_metadata_2025 huggingface dataset:
Bending fluctuations in semiflexible, inextensible, slender filaments in Stokes flow: Toward a spectral discretization
Authors: Maxian Ondrej , Sprinkle Brennan , Donev Aleksandar
Published: April 2023

Semiflexible slender filaments are ubiquitous in nature and cell biology, including in the cytoskeleton, where reorganization of actin filaments allows the cell to move and divide. Most methods for simulating semiflexible inextensible fibers/polymers are based on discrete (bead-link or blob-link) models, which become prohibitively expensive in the slender limit when hydrodynamics is accounted for. In this paper, we develop a novel coarse-grained approach for simulating fluctuating slender filaments with hydrodynamic interactions. Our approach is tailored to relatively stiff fibers whose persistence length is comparable to or larger than their length and is based on three major contributions. First, we discretize the filament centerline using a coarse non-uniform Chebyshev grid, on which we formulate a discrete constrained Gibbs–Boltzmann (GB) equilibrium distribution and overdamped Langevin equation for the evolution of unit-length tangent vectors. Second, we define the hydrodynamic mobility at each point on the filament as an integral of the Rotne–Prager–Yamakawa kernel along the centerline and apply a spectrally accurate “slender-body” quadrature to accurately resolve the hydrodynamics. Third, we propose a novel midpoint temporal integrator, which can correctly capture the Ito drift terms that arise in the overdamped Langevin equation. For two separate examples, we verify that the equilibrium distribution for the Chebyshev grid is a good approximation of the blob-link one and that our temporal integrator for overdamped Langevin dynamics samples the equilibrium GB distribution for sufficiently small time step sizes. We also study the dynamics of relaxation of an initially straight filament and find that as few as 12 Chebyshev nodes provide a good approximation to the dynamics while allowing a time step size two orders of magnitude larger than a resolved blob-link simulation. We conclude by applying our approach to a suspension of cross-linked semiflexible fibers (neglecting hydrodynamic interactions between fibers), where we study how semiflexible fluctuations affect bundling dynamics. We find that semiflexible filaments bundle faster than rigid filaments even when the persistence length is large, but show that semiflexible bending fluctuations only further accelerate agglomeration when the persistence length and fiber length are of the same order.
The evolution of fast turbulent deflagrations to detonations
Authors: Hytovick Rachel , Chambers Jessica , Chin Hardeo , Gamezo Vadim N. , Poludnenko Alexei , Ahmed Kareem
Published: April 2023

We use advanced experimental techniques to explore turbulence-induced deflagration-to-detonation transition (tDDT) in hydrogen–air mixtures. We analyze the full sequence of turbulent flame evolution from fast deflagration-to-detonation using simultaneous direct measurements of pressure, turbulence, and flame, shock, and flow velocities. We show that fast turbulent flames that accelerate and develop shocks are characterized by turbulent flame speeds that exceed the Chapman–Jouguet deflagration speed in agreement with the tDDT theory and direct numerical simulation (DNS) results. Velocity and pressure evolutions are provided to detail the governing mechanisms that drive turbulent flame acceleration. Turbulent flame speeds and fluctuations are examined to reveal flow field characteristics of the tDDT process. This work contributes to the understanding of fundamental mechanisms responsible for spontaneous initiation of detonations by fast turbulent flames.
Impact of cation modification on phonon-dressed exciton dynamics in a prototype two-dimensional hybrid organic–inorganic perovskite system
Authors: Ruan Zhoushilin , Jiang Shenlong , Zhang Qun
Published: April 2023

Organic-cation engineering has recently proven effective in flexibly regulating two-dimensional hybrid organic–inorganic perovskites (2D HOIPs) to achieve a diversity of newly emerging applications. There have been many mechanistic studies based on the structural tunability of organic cations; nevertheless, those with an emphasis on the effect solely caused by the organic cations remain lacking. To this end, here we deliberately design a set of 2D HOIPs in which the inorganic layers are kept nearly intact upon cation modification, i.e., the precursor phenethylammonium lead iodide and its four derivatives with the phenyl group’s para-position H being replaced by CH3, F, Cl, and Br. By means of femtosecond time-resolved transient absorption spectroscopy and temperature-dependent/time-resolved photoluminescence spectroscopy, we interrogate the subtle impact of cation modification on phonon dynamics, coherent phonon modes, phonon-dressed exciton dynamics, and excitonic emissions. A concerted trend for phonon lifetimes and exciton relaxation lifetimes regulated by cation modification is revealed, evidencing the existence of strong exciton–phonon coupling in this 2D HOIP system. The observed mass effect can be ascribed to the change in moment of inertia of organic cations. In addition, we observe an interesting interplay of exciton kinetics pertinent to population transfers between two emissive states, likely linked to the subtle variation in crystal symmetry induced by cation modification. The mechanistic insights gained from this work would be of value for the 2D HOIPs-based applications.
Diffusion within pores fully revealed by magnetic resonance
Authors: Özarslan Evren , Yolcu Cem , Ordinola Alfredo , Boito Deneb , Dela Haije Tom , Højgaard Jensen Mathias , Herberthson Magnus
Published: April 2023

The diffusion propagator fully characterizes the diffusion process, which is highly sensitive to the confining boundaries and the structure within enclosed pores. While magnetic resonance has extensively been used to observe various features of the diffusion process, its full characterization has been elusive. Here, we address this challenge by employing a special sequence of magnetic field gradient pulses for measuring the diffusion propagator, which allows for “listening to the drum,” mapping structural dispersity, and determining not only the pore’s shape but also diffusive dynamics within it.
Rayleigh–Taylor instability in compressible ultra-relativistic degenerate strongly coupled plasma
Authors: Bhambhu Ravinder , Prajapati Ram Prasad
Published: April 2023

Dense stars (e.g., white dwarfs) are composed of mainly ultra-relativistic degenerate electrons and strongly coupled ions subjected to a gravitational field. Considering the physical conditions of such systems, in this paper, we investigate the linear Rayleigh–Taylor (R–T) instability in a compressible ultra-relativistic degenerate strongly coupled plasma (SCP) using the generalized hydrodynamic fluid model. The electron fluid is assumed to be inertialess, ultra-relativistic degenerate, and weakly coupled, while the ion fluid is treated as non-degenerate and strongly coupled. The compressibility effects are considered for the ion fluid in terms of the Coulomb coupling parameter and internal energy. The dispersion properties of the R–T instability have been analyzed using the normal mode analysis. For short wavelength perturbations, the R–T instability excites in the presence of compressibility and degeneracy of ultra-relativistic electrons; otherwise, the characteristic internal wave propagates in the plasma medium. The compressibility and strong coupling effects play a decisive role in suppressing the R–T modes in dense degenerate SCP. In the high-frequency kinetic limit, the instability region is observed to be shorter than the low-frequency hydrodynamic limit. The effects of ultra-relativistic degenerate electrons are almost negligible on the growth rates. However, they significantly modify the dispersion properties and R–T instability criterion. The astrophysical applications of the present work have been discussed in the high-density ultra-relativistic plasmas in the finite flame thickness near the center of white dwarfs.
Energy response and spatial alignment of the perturbed electron gas
Authors: Dornheim Tobias , Tolias Panagiotis , Moldabekov Zhandos A. , Vorberger Jan
Published: April 2023

We study the linear energy response of the uniform electron gas to an external harmonic perturbation with a focus on resolving different contributions to the total energy. This has been achieved by carrying out highly accurate ab initio path integral Monte Carlo (PIMC) calculations for a variety of densities and temperatures. We report a number of physical insights into effects such as screening and the relative importance of kinetic and potential energies for different wave numbers. A particularly interesting finding is obtained from the observed non-monotonic behavior of the induced change in the interaction energy, which becomes negative for intermediate wave numbers. This effect is strongly dependent on the coupling strength and constitutes further direct evidence for the spatial alignment of electrons introduced in earlier works [T. Dornheim et al., Commun. Phys. 5, 304 (2022)]. The observed quadratic dependence on the perturbation amplitude in the limit of weak perturbations and the quartic dependence of perturbation amplitude corrections are consistent with linear and nonlinear versions of the density stiffness theorem. All PIMC simulation results are freely available online and can be used to benchmark new methods or as input for other calculations.
Study of reaction-diffusion controlled mass transport in stopped-flow fluidics for spatiotemporal multiplexing
Authors: Tintelott Marcel , Gharpure Pradnya , Coffinier Yannick , Vu Xuan Thang , Vlandas Alexis , Ingebrandt Sven , Pachauri Vivek
Published: April 2023

Integration of biochemical reaction networks (BRNs) with biosensor platforms has emerged as a technological niche overcoming challenges related to the loss of sensitivity and selectivity in biological media. Optimal operation of BRNs in microfluidics requires control over reaction-diffusion dominated mass transport, heavily influenced by fluidic parameters. In this work, we study and design an on-chip platform combining a programable unique molecular amplification as BRNs with nanoscale biologically sensitive field-effect transistor (BioFET) arrays, which employs a physical diffusion barrier to gain spatial and temporal control over mass transport. Computational and numerical approaches, such as finite element and finite volume methods, were implemented to solve partial differential equations numerically after domain approximation by numerous finite elements. The focus on geometrical optimizations of fluidics is aimed at mass transport to occur with precise spatial and temporal control toward BioFET-arrays. Adopting a 0.5 pM limit-of-detection (LoD) for biochemical monitoring of BRNs via a single-stranded deoxyribonucleic acid (ssDNA) output, we show that it was possible to compartmentalize the mass transport spatiotemporally without crosstalk, which can be of critical advantage for using biosensor arrays in order to realize simplified multiplexed point-of-care biosensors.
Phase coexistence implications of violating Newton’s third law
Authors: Chiu Yu-Jen , Omar Ahmad K.
Published: April 2023

Newton’s third law, action = reaction, is a foundational statement of classical mechanics. However, in natural and living systems, this law appears to be routinely violated for constituents interacting in a nonequilibrium environment. Here, we use computer simulations to explore the macroscopic phase behavior implications of breaking microscopic interaction reciprocity for a simple model system. We consider a binary mixture of attractive particles and introduce a parameter that is a continuous measure of the degree to which interaction reciprocity is broken. In the reciprocal limit, the species are indistinguishable, and the system phase separates into domains with distinct densities and identical compositions. Increasing nonreciprocity is found to drive the system to explore a rich assortment of phases, including phases with strong composition asymmetries and three-phase coexistence. Many of the states induced by these forces, including traveling crystals and liquids, have no equilibrium analogs. By mapping the complete phase diagram for this model system and characterizing these unique phases, our findings offer a concrete path forward toward understanding how nonreciprocity shapes the structures found in living systems and how this might be leveraged in the design of synthetic materials.
Confinement controlled dynamical structural rearrangement in a quasi-2D dusty plasma crystal
Authors: Singh Swarnima , Bandyopadhyay P. , Kumar Krishan , Sen A.
Published: April 2023

In this work, we present experimental results on the structural transition of a two-dimensional dust crystal through controlled adjustment of its radial confinement while keeping all other discharge parameters constant. The experiments are performed in an L-shaped Dusty Plasma Experimental device in a DC glow discharge argon plasma environment. Initially, a purely 2D dust crystal is formed inside a circular confining ring at the interface of the plasma-cathode sheath region. This monolayer with a hexagonal lattice configuration of the dust particles gets buckled when the sheath thickness around the radial confinement ring is reduced. A bilayer with a square lattice configuration emerges in the dust system due to the onset of a transverse instability. The multiple crystalline domains at this lower confinement show signatures of a constant structural rearrangement in the system. The timescale associated with this rearrangement is quantified from the bond-orientational correlation function. It is found that the heterogeneous cooperative micro-motion of particles in the quasi-layered system is responsible for the rearrangement over the passage of time.
The gas-phase structure determination of α-pinene oxide: An endo-cyclic epoxide of atmospheric interest
Authors: Neeman E. M. , Osseiran N. , Huet T. R.
Published: April 2023

The gas-phase rotational spectra of α-pinene oxide have been recorded using a chirped-pulse Fourier transform microwave spectrometer in the 6–18 GHz frequency range. The parent species and all heavy atom isotopologues (13C and 18O) have been observed in their natural abundance. The experimental rotational constants of all isotopic species observed have been determined and used to obtain the substitution (rs) and the effective (r0) structures of the most stable conformer of α-pinene oxide. Calculations using the density functional theories B3LYP, M06-2X, and MN15-L and the ab initio method MP2 level of theory were carried out to check their performance against experimental results. The structure of the heavy atom’s skeleton of α-pinene oxide has been compared to that of α-pinene and has shown that epoxidation does not overly affect the structure of the bicycle, validating its robustness. Furthermore, the structural features have been compared to those of other bicyclic molecules, such as nopinone and β-pinene.
Mechanical behaviour of thermoelectric materials – a perspective
Authors: Al Malki Muath M. , Snyder G. Jeffrey , Dunand David C.
Published: April 2023

Research on thermoelectric materials – with their vast potential for applications in solid-state cooling or energy-conversion devices – has so far mainly focused on enhancing their conversion efficiency. However, understanding and tailoring the mechanical performance of thermoelectric modules and devices is crucial for their long-term use, as they are subjected to spatially-complex and time-varying thermomechanical stresses – both internal and external – which may lead to plastic, fatigue and/or creep deformation. This leads to changes in thermoelectric performance, dimensions ( via strain accumulation) and mechanical integrity ( via crack and pore formation, leading to failure). This review addresses the current understanding of various modes of stress-induced deformation that can take place during extended operation of thermoelectric materials and their impact on the strain (elastic, plastic, and creep), and the associated damage (bloating, fatigue, and fracture). Finally, some new areas of research straddling mechanical and thermoelectric behaviour are identified.
Bilateral supplementary comparison of high voltage transformer measuring systems
Authors: Ayhan B , Çaycı H , Räther P , Mohns E
Published: April 2023

Main text

A comparison of high voltage transformer measuring systems of TÜBİTAK UME (Türkiye) and PTB (Germany) was conducted between August 2021 and August 2022. The comparison was registered as EURAMET Project No: EM 1492 and EURAMET.EM - S43 in the BIPM key comparison database. Ratio error and phase displacement of the voltage transformers were measured at voltages from 3 kV to 110/√3 kV, at 50.2 Hz and 60 Hz. The main targets of the comparison were to underpin and strengthen the capabilities of the National Metrology Institutes. The results of the participants were found to be equivalent, comparable and in agreement with the comparison reference values within stated uncertainties of measurements.

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/.

The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Front-side releasing <110> oriented clamped–clamped beams for piezoresistive sensors
Authors: Han Jianqiang , Sun Weihua
Published: April 2023

Front-side releasing suspended structures made using bulk micromachining processes have the advantages of simplifying vacuum or hermetic packaging processes and reducing squeeze-film damping. This paper studies the effect of doping concentration on the etching rate (ER) of the (111) plane. The experimental results show that increasing the boron doping concentration (but to less than the self-stop etching concentration) significantly increases the ER of the (111) plane and the ER ratio of the (111) and (100) planes. This phenomenon is used to speed up the undercutting and release <110> oriented clamped–clamped beams, which can be used as piezoresistive sensitive elements. The etching depth when the microbeams have just been released and the silicon wedges under single beams, double beams and triple beams disappear is deduced and verified by experiments. This has a certain guiding significance for designing piezoresistive sensors.
A method for multiplexed and volumetric-based magnetic particle spectroscopy bioassay: mathematical study
Authors: Chugh Vinit Kumar , Liang Shuang , Yari Parsa , Wu Kai , Wang Jian-Ping
Published: April 2023

Magnetic particle spectroscopy (MPS) is an emerging biosensing technique that detects target analytes by exploiting the dynamic magnetic responses of magnetic nanoparticles (MNPs). Due to the ease of synthesis and surface chemical functionalization of MNPs, MPS-based bioassays have gained popularity around the globe. One limiting factor for MPS-based assay is the ability to detect multiple analytes simultaneously in a single run, namely, multiplexed bioassay. Several groups have reported the realization of multiplexed bioassays on surface-based MPS platforms by spatially separating reaction areas by using the unique magnetic responses of different MNPs. In this work, we systematically study the magnetization curves (M-H curves) of different types of MNPs and their relationship to the dynamic magnetic responses when subjected to AC magnetic driving fields. Due to the different structures, sizes, and magnetic properties of each kind of MNP, the resulting harmonics are unique. Thus, concurrent quantification (also called ‘colorization’) of each type of MNP in a mixture is possible by solving the harmonic matrix function. Our results show that the uniqueness of M-H response curves of selected types of MNP and the signal-to-noise ratio of the system can affect the accuracy of multiplexed, volumetric-based MPS bioassays. The reported method assumes that each type of MNPs nanoparticles does not interact, and that the magnetic response of the mixture is a linear combination of the responses of each kind of MNP. This assumption may not hold for very dense systems where inter-particle interactions become significant and may require more complex models.
Frequency spectrum of radiation transfer in high voltage circuit breaker arcs for polymer nozzle ablation in C4F7N and CO2 gas mixture
Authors: Zhou Mingyu , Xu Ruoyu , Esmaeili S , Ding Yi , Lei Zonghan , Yan J D
Published: April 2023

Arc radiation-induced polymer nozzle ablation plays a crucial role in the operation of self-blast circuit breakers. Up to now, there is no study specifically on the spectral distribution of radiated power from a switching arc towards the nozzle surface and its implication to nozzle ablation. Three-dimensional radiation transfer calculation has been performed in this study for arcs burning in the mixture of

C

4

F

7

N

+

C

O

2

+

PTFE

, a gaseous environment that is under significant focus in the development of SF6 free switching technology to aim net-zero by the middle of this century. Results show that photons from infrared to extreme ultraviolet (UV, up to 5 × 1015 Hz) are emitted from the core of high current arcs. However, the high-frequency photons are mostly absorbed within the arc column, especially at the arc edge, and only photons up to

1.7
×

10

15

 Hz

(far UV, 7 eV) can penetrate the arc edge and cold gas and reach the nozzle surface. The spectral distribution of the radiative energy at different instantaneous currents (15 kA, 28 kA and 60 kA peak) and different locations of the nozzle is presented and compared in detail. The location of the radiation absorption zone at the arc edge and the radiative power reaching the nozzle wall as a function of the instantaneous current is, in particular, purposely considered.
Tunability of spin-wave spectra in a 2D triangular shaped magnonic fractals
Authors: Mehta R , Moalic M , Krawczyk M , Saha S
Published: April 2023

Reprogramming the structure of the magnonic bands during their operation is important for controlling spin waves in magnonic devices. Here, we report the tunability of the spin-wave spectra for a triangular shaped deterministic magnonic fractal, which is known as Sierpinski triangle by solving the Landau–Lifshitz–Gilbert equation using a micromagnetic simulations. The spin-wave dynamics change significantly with the variation of iteration number. A wide frequency gap is observed for a structure with an iteration number exceeding some value and a plenty of mini-frequency bandgaps at structures with high iteration number. The frequency gap could be controlled by varying the strength of the magnetic field. A sixfold symmetry in the frequency gap is observed with the variation of the azimuthal angle of the external magnetic field. The spatial distributions of the spin-wave modes allow to identify the bands surrounding the gap. The observations are important for the application of magnetic fractals as a reconfigurable aperiodic magnonic crystals.
Non-invasive, intelligent, and continuous monitoring of human blood glucose with UWB dual-antenna and cascade CNN
Authors: Wang Zengxiang , Xiao Xia , Pang Yanwei , Su Wenling
Published: April 2023

Finger-prick blood collection process has become unrealistic for a long-term and frequent blood glucose detection. Hence, an appropriate non-invasive detection system is highly desirable to effectively address this concern. A non-invasive and intelligent dual-sensing system is forwarded in this paper. The feasibility of the proposed system has been verified using glucose solution, animal serum, and human trials. In the in vivo experiments, the detection signal exhibited a high correlation (r = 0.96) with blood glucose levels. An improved cascade convolution neural network is suggested to accurately predict the BGL. For the estimation results of BGL, the root mean squared error of 7.3217 mg dl−1 and a mean absolute relative difference of 4.7209% are achieved. The estimated results also fell by 100% in the clinically acceptable zones of the Clarke error grid analysis, indicating that the proposed system could potentially be used for clinical measurements.
Infinite WARM graphs III: strong reinforcement regime
Authors: Hirsch Christian , Holmes Mark , Kleptsyn Victor
Published: April 2023

We study a reinforcement process on graphs G of bounded degree. The model involves a parameter α > 0 governing the strength of reinforcement, and Poisson clock rates λ

v
at the vertices v of the graph. When the Poisson clock at a vertex v rings, one of the edges incident to it is reinforced, with edge e being chosen with probability proportional to its current count (counts start from 1) raised to the power α. The main problem in such models is to describe the (random) subgraph

, consisting of edges that are reinforced infinitely often. In this paper, we focus on the finite connected components of

in the strong reinforcement regime (α > 1) with clock rates that are uniformly bounded above. We show here that when α is sufficiently large, all connected components of

are trees. When the firing rates λ

v
are constant, we show that all components are trees of diameter at most 3 when α is sufficiently large, and that there are infinitely many phase transitions as

α
↓
1

. For example, on the triangular lattice, increasingly large (odd) cycles appear as

α
↓
1

(while on the square lattice no finite component of

contains a cycle for any α > 1). Increasingly long paths and other structures appear in both lattices when taking

α
↓
1

. In the special case where

G
=

Z

and α > 1, all connected components of

are finite and we show that the possible cluster sizes are non-monotone in α. We also present several open problems.
Impact of motion correction on [18F]-MK6240 tau PET imaging
Authors: Tiss Amal , Marin Thibault , Chemli Yanis , Spangler-Bickell Matthew , Gong Kuang , Lois Cristina , Petibon Yoann , Landes Vanessa , Grogg Kira , Normandin Marc , Becker Alex , Thibault Emma , Johnson Keith , El Fakhri Georges , Ouyang Jinsong
Published: April 2023

Objective. Positron emission tomography (PET) imaging of tau deposition using [18F]-MK6240 often involves long acquisitions in older subjects, many of whom exhibit dementia symptoms. The resulting unavoidable head motion can greatly degrade image quality. Motion increases the variability of PET quantitation for longitudinal studies across subjects, resulting in larger sample sizes in clinical trials of Alzheimer’s disease (AD) treatment. Approach. After using an ultra-short frame-by-frame motion detection method based on the list-mode data, we applied an event-by-event list-mode reconstruction to generate the motion-corrected images from 139 scans acquired in 65 subjects. This approach was initially validated in two phantoms experiments against optical tracking data. We developed a motion metric based on the average voxel displacement in the brain to quantify the level of motion in each scan and consequently evaluate the effect of motion correction on images from studies with substantial motion. We estimated the rate of tau accumulation in longitudinal studies (51 subjects) by calculating the difference in the ratio of standard uptake values in key brain regions for AD. We compared the regions’ standard deviations across subjects from motion and non-motion-corrected images. Main results. Individually, 14% of the scans exhibited notable motion quantified by the proposed motion metric, affecting 48% of the longitudinal datasets with three time points and 25% of all subjects. Motion correction decreased the blurring in images from scans with notable motion and improved the accuracy in quantitative measures. Motion correction reduced the standard deviation of the rate of tau accumulation by −49%, −24%, −18%, and −16% in the entorhinal, inferior temporal, precuneus, and amygdala regions, respectively. Significance. The list-mode-based motion correction method is capable of correcting both fast and slow motion during brain PET scans. It leads to improved brain PET quantitation, which is crucial for imaging AD.
Inter-crystal scattering event identification using a novel silicon photomultiplier signal multiplexing method
Authors: Shim Hyeong Seok , Bae Sangjin , Lee Seungeun , Lee Jae Sung
Published: April 2023

Objective. Identifying the inter-crystal scatter (ICS) events and recovering the first interaction position enables the accurate determination of the line-of-response in positron emission tomography (PET). However, conventional silicon photomultiplier (SiPM) signal multiplexing methods based on two-dimensional (2D) charge-division circuits do not allow the detection of multiple gamma-ray interaction positions in a scintillation array coupled with a SiPM array. In this study, we propose a novel multiplexing method that can restore all the individual channel data from a smaller number of multiplexed channels using high-pass filters and neural networks. Approach. The number of output channels is reduced by summing the SiPM signals that have passed through high-pass filters with different time constants. Then, the signal amplitude of each SiPM channel is restored from the combined signal using an artificial neural network. This study explains the principle of this method in detail and demonstrates the results using 4:1 multiplexing as an example. The usefulness of this method was also demonstrated by its application in the identification of ICS events in 1-to-1 coupled LSO-SiPM PET detectors. Main results. The artificial neural network enabled accurate energy estimation for each SiPM channel. One of the high-pass filter sets with the lowest Cramér–Rao lower bound provided the best results, yielding R
2 value of 0.99 between the true and estimated signals. The energy and flood histograms generated using the best-estimated signals were in good agreement with the ground truth. Additionally, the proposed method accurately estimated 2D energy deposit distribution in the LSO crystal array, allowing ICS event identification. Significance. The proposed method is potentially useful for ICS event recovery with a reduced number of array signal readout channels from a SiPM array.
Critical site percolation on the triangular lattice: from integrability to conformal partition functions
Authors: Morin-Duchesne Alexi , Klümper Andreas , Pearce Paul A
Published: April 2023

Critical site percolation on the triangular lattice is described by the Yang–Baxter solvable dilute

A
2

(
2
)

loop model with crossing parameter specialized to

λ
=

π
3

, corresponding to the contractible loop fugacity

β
=
−
2
cos
4
λ
=
1

. We study the functional relations satisfied by the commuting transfer matrices of this model and the associated Bethe ansatz equations. The single and double row transfer matrices are respectively endowed with strip and periodic boundary conditions, and are elements of the ordinary and periodic dilute Temperley–Lieb algebras. The standard modules for these algebras are labelled by the number of defects d and, in the latter case, also by the twist

e

i

γ

. Nonlinear integral equation techniques are used to analytically solve the Bethe ansatz functional equations in the scaling limit for the central charge c = 0 and conformal weights

Δ
,

Δ
ˉ

. For the ground states, we find

Δ
=

Δ

1
,
d
+
1

for strip boundary conditions and

(
Δ
,

Δ
ˉ

)
=
(

Δ

γ

/

π
,
d

/

2

,

Δ

γ

/

π
,
−
d

/

2

)

for periodic boundary conditions, where

Δ

r
,
s

=

1
24

(

(
3
r
−
2
s

)
2

−
1

)

. We give explicit conjectures for the scaling limit of the trace of the transfer matrix in each standard module. For

d
⩽
8

, these conjectures are supported by numerical solutions of the logarithmic form of the Bethe ansatz equations for the leading 20 or more conformal eigenenergies. With these conjectures, we apply the Markov traces to obtain the conformal partition functions on the cylinder and torus. These precisely coincide with our previous results for critical bond percolation on the square lattice, described by the dense

A
1

(
1
)

loop model with

λ
=

π
3

. The concurrence of all this conformal data provides compelling evidence supporting a strong form of universality between these two stochastic models as logarithmic conformal field theories.
All-optical control of ultrafast plasmon resonances in the pulse-driven extraordinary optical transmission
Authors: Asif Hira , Tasgin Mehmet Emre , Sahin Ramazan
Published: April 2023

Understanding ultrafast processes in their natural timescale is crucial for controlling and manipulating nanoscale optoelectronic devices under light–matter interaction. Here, we demonstrate that ultrafast plasmon resonances, attributed to the phenomenon of extraordinary optical transmission (EOT), can be significantly modified by tuning the spectral and temporal properties of the ultrashort light pulse. In this scheme, all-optical active tuning governs the spatial and temporal enhancement of plasmon oscillations in the EOT system without device customization. We analyze the spectral and temporal evolution of the system using two approaches. First, we develop a theoretical framework based on the coupled harmonic oscillator model, which analytically describes the dynamics of plasmon modes in the coupled and uncoupled states. Later, we compare the evolution of the system under continuous-wave and pulsed illumination. Further, we discuss the time-resolved spectral and spatial dynamics of plasmon modes using a 3D finite difference time-domain simulation method and wavelet transform. Our results show that optical tuning of the oscillation time, intensity, and spectral properties of propagating and localized plasmon modes yields a three-fold enhancement in the EOT signal. The active tuning of the EOT sensor through ultrashort light pulses paves the way for the development of on-chip photonic devices employing high-resolution imaging and sensing of abundant atomic and molecular systems.
Non-integral model-based scatterometry for CD metrology of single high-aspect-ratio microstructures
Authors: Chein Wei-Hsin , Yang Fu-Sheng , Fu Zi-Ying , Chen Liang-Chia
Published: April 2023

This article presents an innovative model-based scatterometry method for CD metrology of single high-aspect-ratio (HAR) microstructures, which are increasingly utilized in advanced packaging, especially as vertical interconnects in three-dimensional integrated circuits. The rapidly growing aspect ratio of these HAR structures makes it challenging to monitor their critical dimensions (CD). Furthermore, conventional spectral reflectometry or scatterometry measurements on periodic metrology targets on the scribe lines of the wafer are inadequate in providing a reliable correlation with the in-die structures due to the integral nature of these measurements, which can result in additional measurement errors compared to measuring individual in-die structures. To address these challenges, we propose a novel scatterometry system that can achieve high-precision single-structure measurement of fine-pitch HAR structures with significantly improved light efficiency over conventional optical methods. Our system takes advantage of the high spatial coherence of the supercontinuum laser source and an optical NA-controlled design concept for precise light beam shaping, enabling high spatial resolution and superior light efficiency in measurements. Furthermore, we demonstrate a model-based measurement scheme that uses a virtual optical system for complete characterization of the sample profile. The experimental results show that the proposed system can accurately measure RDL structures with fine nominal spacing as small as 1 μm and an aspect ratio of 3:1 with high fidelity.
Magnetic field control of light-induced spin accumulation in monolayer MoSe2
Authors: Rojas-Lopez Rafael R , Hendriks Freddie , van der Wal Caspar H , Guimarães Paulo S S , Guimarães Marcos H D
Published: April 2023

Semiconductor transition metal dichalcogenides (TMDs) have equivalent dynamics for their two spin/valley species. This arises from their energy-degenerated spin states, connected via time-reversal symmetry. When an out-of-plane magnetic field is applied, time-reversal symmetry is broken and the energies of the spin-polarized bands shift, resulting in different bandgaps and dynamics in the K

+

and K

−

valleys. Here, we use time-resolved Kerr rotation to study the magnetic field dependence of the spin dynamics in monolayer MoSe2. We show that the magnetic field can control the light-induced spin accumulation of the two valley states, with a small effect on the recombination lifetimes. We unveil that the magnetic field-dependent spin accumulation is in agreement with hole spin dynamics at the longer timescales, indicating that the electron spins have faster relaxation rates. We propose a rate equation model that suggests that lifting the energy-degeneracy of the valleys induces an ultrafast spin-flip toward the stabilization of the valley with the higher valence band energy. Our results provide an experimental insight into the ultrafast charge and spin dynamics in TMDs and a way to control it, which will be useful for the development of new spintronic and valleytronic applications.
Thermokinetics of point defects in α-Fe2O3
Authors: Banerjee Amitava , Holby Edward F , Kohnert Aaron A , Srivastava Shivani , Asta Mark , Uberuaga Blas P
Published: April 2023

Point defect formation and migration in oxides governs a wide range of phenomena from corrosion kinetics and radiation damage evolution to electronic properties. In this study, we examine the thermodynamics and kinetics of anion and cation point defects using density functional theory in hematite (

α

-Fe2O3), an important iron oxide highly relevant in both corrosion of steels and water-splitting applications. These calculations indicate that the migration barriers for point defects can vary significantly with charge state, particularly for cation interstitials. Additionally, we find multiple possible migration pathways for many of the point defects in this material, related to the low symmetry of the corundum crystal structure. The possible percolation paths are examined, using the barriers to determine the magnitude and anisotropy of long-range diffusion. Our findings suggest highly anisotropic mass transport in hematite, favoring diffusion along the c-axis of the crystal. In addition, we have considered the point defect formation energetics using the largest Fe2O3 supercell reported to date.
Applications of physics informed neural operators
Authors: Rosofsky Shawn G , Al Majed Hani , Huerta E A
Published: April 2023

We present a critical analysis of physics-informed neural operators (PINOs) to solve partial differential equations (PDEs) that are ubiquitous in the study and modeling of physics phenomena using carefully curated datasets. Further, we provide a benchmarking suite which can be used to evaluate PINOs in solving such problems. We first demonstrate that our methods reproduce the accuracy and performance of other neural operators published elsewhere in the literature to learn the 1D wave equation and the 1D Burgers equation. Thereafter, we apply our PINOs to learn new types of equations, including the 2D Burgers equation in the scalar, inviscid and vector types. Finally, we show that our approach is also applicable to learn the physics of the 2D linear and nonlinear shallow water equations, which involve three coupled PDEs. We release our artificial intelligence surrogates and scientific software to produce initial data and boundary conditions to study a broad range of physically motivated scenarios. We provide the source code, an interactive website to visualize the predictions of our PINOs, and a tutorial for their use at the Data and Learning Hub for Science.
The role of miRNA molecules in the miscarriage process
Authors: Omeljaniuk Wioleta Justyna , Laudański Piotr , Miltyk Wojciech
Published: April 2023

The etiology and pathogenesis of miscarriage, which is the most common pregnancy complication, have not been fully elucidated. There is a constant search for new screening biomarkers that would allow for the early diagnosis of disorders associated with pregnancy pathology. The profiling of microRNA expression is a promising research area, which can help establish the predictive factors for pregnancy diseases. Molecules of microRNAs are involved in several processes crucial for the development and functioning of the body. These processes include cell division and differentiation, programmed cell death, blood vessel formation or tumorigenesis, and the response to oxidative stress. The microRNAs affect the number of individual proteins in the body due to their ability to regulate gene expression at the post-transcriptional level, ensuring the normal course of many cellular processes. Based on the scientific facts available, this paper presents a compendium on the role of microRNA molecules in the miscarriage process. The expression of potential microRNA molecules as early minimally invasive diagnostic biomarkers may be evaluated as early as the first weeks of pregnancy and may constitute a monitoring factor in the individual clinical care of women in early pregnancy, especially after the first miscarriage. To summarize, the described scientific data set a new direction of research in the development of preventive care and prognostic monitoring of the course of pregnancy.
From Acculturation to Transculturation?: Police Culture Change in the Pluralized Crime Investigation Department
Authors: Rice Lindsey
Published: April 2023

This article uses the concept of transculturation (Ortiz 1944) as a lens to examine the effects of civilianization on the (re)production of ‘detective culture’ in two police forces in England. It critiques acculturation as the principal framework for understanding the complexity of cultural (ex)change processes happening within pluralized police settings. By bridging police studies with postcolonial theory, this article provides an innovative account of cultural (re)production under conditions of modernization, specifically, within the context of contemporary crime investigation. The original findings presented reveal the subtle yet active role played by civilian investigators in this process. The article concludes by challenging criminologists to explore the explanatory potential of transculturation in other areas of criminal justice, both in the United Kingdom and internationally.
Local relapse of soft tissue sarcoma of the extremities or trunk wall operated on with wide margins without radiation therapy
Authors: Lemma Jasmiini , Jäämaa Sari , Repo Jussi P , Santti Kirsi , Salo Juho , Blomqvist Carl P , Sampo Mika M
Published: April 2023

Background

The quality of surgical margins is the most important factor affecting local control in soft tissue sarcoma (STS). Despite this, there is no universally accepted consensus on the definition of an adequate surgical margin or on which patients should be offered radiation therapy. This study focuses on local control and its prognostic factors in patients with trunk wall and extremity STS.

Methods

Adult patients with a final diagnosis of trunk wall or extremity STS referred to a single tertiary referral centre between August 1987 and December 2016 were identified from a prospective institutional database. Patients were treated according to a protocol instituted in 1987. The classification of surgical margins and indications for radiation therapy were based on anatomy and strict definition of surgical margins as metric distance to the resection border. Local treatment was defined as adequate if patients received either surgery with wide margins alone or marginal surgery combined with radiation therapy. Margins were considered wide if the tumour was excised with pathological margins greater than 2.5 cm or with an uninvolved natural anatomical barrier. After treatment, patients were followed up with local imaging and chest X-ray: 5 years for high-grade STS, 10 years for low-grade STS.

Results

A total of 812 patients were included with a median follow-up of 5.8 (range 0.5-19.5) years. Forty-four patients had a grade 1 tumour: there were no instances of recurrence in this group thus they were excluded from further analysis. Five-year local control in the 768 patients with grade 2-3 STS was 90.1 per cent in patients receiving adequate local treatment according to the protocol. Altogether, 333 patients (43.4 per cent) were treated with wide surgery alone and their 5-year local control rate was 91.1 per cent. Among patients treated with wide surgery alone, deep location was the only factor adversely associated with local relapse risk in multivariable analysis; 5-year local control was 95.3 per cent in superficial and 88.3 per cent in deep-sited sarcomas (hazards ratio 3.154 (95% c.i. 1.265 to 7.860), P = 0.014).

Conclusion

A high local control rate is achievable with surgery alone for a substantial proportion of patients with STS of the extremities or superficial trunk wall.
Single injection of lidocaine to reduce tourniquet hypertension in ambulatory arthroscopic patients under general anaesthesia: randomized, double-blind, placebo-controlled clinical trial
Authors: Sun Yue , Zhao Jianhui , Guo Wenli , Mu Hailing , Zhao Ying , Xie Yaping , Yang Chen , Lu Yao
Published: April 2023

Background

This prospective study investigated whether a single dose of intravenous lidocaine could alleviate tourniquet hypertension in patients undergoing ambulatory arthroscopy under general anaesthesia.

Methods

Patients aged 18–65 years undergoing knee arthroscopy under general anaesthesia were randomly divided into the lidocaine group (L group) and the normal saline group (N group). Patients received an intravenous injection 10 min before tourniquet inflation of either 1.5mg/kg lignocaine made up to 10ml with 0.9 per cent normal saline, or 10ml of 0.9 per cent normal saline. The primary outcome was the incidence of tourniquet hypertension. Secondary outcomes included haemodynamic changes, degree of elevation of blood pressure, changes in serum inflammatory indicators including interleukin 6 and tumour necrosis factor-α, the numerical rating scale, 15-item quality of recovery after surgery, the incidence of adverse events and the duration of hospital stay. Randomization was computer-generated with allocation concealment by sealed envelopes. Patients, caregivers and researchers were all blind to the allocation group throughout the study.

Results

Ninety-six patients were included in the study; 48 in each group. Compared with the N group, the incidence of tourniquet hypertension in the L group was significantly lower (37.5 per cent versus 68.8 per cent; P < 0.002). The degree of elevation of systolic blood pressure from baseline to the end of surgery in the L group was significantly lower than the N group (17.1 per cent versus 23.6 per cent; P = 0.020). The concentration of tumour necrosis factor-α in the L group 5 min after tourniquet deflation was lower than in the N group (32.12 pg/ml versus 39.89 pg/ml; P = 0.029). The median numerical rating scale of the L group was significantly lower at 6 h (0 versus 3.0; P = 0.003) and 24 h (0 versus 2.0; P < 0.001) after surgery. In the L group, the total 15-item quality of recovery was significantly increased (131 versus 128; P = 0.017).

Conclusion

Single injection of intravenous lidocaine alleviated tourniquet hypertension in ambulatory arthroscopic patients under general anaesthesia. Intravenous lidocaine can inhibit tourniquet hypertension formation by reducing tumour necrosis factor-α release, and has beneficial effects on postoperative pain and recovery.

Registration number

ChiCTR2200055551 (http://www.chictr.org.cn/edit.aspx? pid=148235&htm=4).