bluuebunny/crossref_metadata_2025 huggingface dataset:
Frontiers, challenges, and solutions in modeling of swift heavy ion effects in materials
Authors: Medvedev N. , Volkov A. E. , Rymzhanov R. , Akhmetov F. , Gorbunov S. , Voronkov R. , Babaev P.
Published: March 2023

Since a few breakthroughs in the fundamental understanding of the effects of swift heavy ions (SHIs) decelerating in the electronic stopping regime in the matter have been achieved in the last decade, it motivated us to review the state-of-the-art approaches in the modeling of SHI effects. The SHI track kinetics occurs via several well-separated stages and spans many orders of magnitude in time: from attoseconds in ion-impact ionization depositing an extreme amount of energy in a target to femtoseconds of electron transport and hole cascades, to picoseconds of lattice excitation and response, to nanoseconds of atomic relaxation, and even longer times of the final macroscopic reaction. Each stage requires its own approaches for quantitative description. We discuss that understanding the links between the stages makes it possible to describe the entire track kinetics within a hybrid multiscale model without fitting procedures. The review focuses on the underlying physical mechanisms of each process, the dominant effects they produce, and the limitations of the existing approaches, as well as various numerical techniques implementing these models. It provides an overview of the ab initio-based modeling of the evolution of the electronic properties, Monte Carlo simulations of nonequilibrium electronic transport, molecular dynamics modeling of atomic reaction including phase transformations and damage on the surface and in the bulk, kinetic Mote Carlo of atomic defect kinetics, and finite-difference methods of track interaction with chemical solvents describing etching kinetics. We outline the modern methods that couple these approaches into multiscale and combined multidisciplinary models and point to their bottlenecks, strengths, and weaknesses. The analysis is accompanied by examples of important results, improving the understanding of track formation in various materials. Summarizing the most recent advances in the field of the track formation process, the review delivers a comprehensive picture and detailed understanding of the phenomenon. Important future directions of research and model development are also outlined.
Thermoreflectance-based approach for surface temperature measurements of thin-film gold sensors
Authors: Farbaniec L. , Eakins D. E.
Published: March 2023

A novel thermoreflectance-based diagnostic tool capable of visualizing spatial and temporal changes in surface temperature is presented. The method uses narrow spectral emission bands of blue [λ = 405 nm with 10 nm full-width-at-half-maximum (FWHM)] and green (λ = 532 nm with 10 nm FWHM) light to monitor the optical properties of gold and thin-film gold sensors, relating changes in reflectivity to temperature through a known calibration coefficient. The system is made robust to tilt and surface roughness variations through the simultaneous measurement of both probing channels with a single camera. Experimental validation is performed on two forms of gold materials heated from room temperature to 200 °C at a rate of ∼100 °C/min. Subsequent image analysis shows perceptible changes in reflectivity in the narrow band of green light, while the blue light remains temperature-insensitive. The reflectivity measurements are used to calibrate a predictive model with temperature-dependent parameters. The physical interpretation of the modeling results is given, and the strengths and limitations of the presented approach are discussed.
Low-dimensional bihamiltonian structures of topological type
Authors: Dinar Yassir
Published: March 2023

We construct local bihamiltonian structures from classical W-algebras associated with non-regular nilpotent elements of regular semisimple type in Lie algebras of types A2 and A3. They form exact Poisson pencils and admit a dispersionless limit, and their leading terms define logarithmic or trivial Dubrovin–Frobenius manifolds. We calculate the corresponding central invariants, which are expected to be constants. In particular, we get Dubrovin–Frobenius manifolds associated with the focused Schrödinger equation and Hurwitz space M0;1,0 and the corresponding bihamiltonian structures of topological type.
Local Dirac Synchronization on networks
Authors: Calmon Lucille , Krishnagopal Sanjukta , Bianconi Ginestra
Published: March 2023

We propose Local Dirac Synchronization that uses the Dirac operator to capture the dynamics of coupled nodes and link signals on an arbitrary network. In Local Dirac Synchronization, the harmonic modes of the dynamics oscillate freely while the other modes are interacting non-linearly, leading to a collectively synchronized state when the coupling constant of the model is increased. Local Dirac Synchronization is characterized by discontinuous transitions and the emergence of a rhythmic coherent phase. In this rhythmic phase, one of the two complex order parameters oscillates in the complex plane at a slow frequency (called emergent frequency) in the frame in which the intrinsic frequencies have zero average. Our theoretical results obtained within the annealed approximation are validated by extensive numerical results on fully connected networks and sparse Poisson and scale-free networks. Local Dirac Synchronization on both random and real networks, such as the connectome of Caenorhabditis Elegans, reveals the interplay between topology (Betti numbers and harmonic modes) and non-linear dynamics. This unveils how topology might play a role in the onset of brain rhythms.
Comparative study of two combined blowing and suction flow control methods on pitching airfoils
Authors: Ma Cheng-Yu , Xu He-Yong , Qiao Chen-Liang
Published: March 2023

A comparative study of two combined blowing/suction flow control methods was conducted on the pitching airfoil using the unsteady Reynolds-averaged Navier–Stokes (URANS) method. One used leading-edge blowing and trailing-edge suction, which is referred to as a co-flow jet (CFJ), and a conformal slot CFJ (C-CFJ) was adopted. Another used leading-edge suction combined with trailing-edge blowing, which was called reversed CFJ (R-CFJ). The S809 airfoil was used as the baseline as its stall characteristic is suitable for separation flow or stall control research. Aerodynamic coefficients of these two combined blowing/suction methods were compared under no-stall, mild-stall, and deep-stall cases. The net gain of output power was also discussed if CFJ methods were used for wind energy applications. The influence mechanism of these two methods on the flow around the airfoil was revealed. The results showed that the C-CFJ is suitable for the no-stall and mild-stall cases, while the R-CFJ is suitable for the deep-stall case. Leading-edge suction is more stable than leading-edge blowing when suppressing the dynamic stall. The leading-edge jet flow will cause dynamic stalls when it is detached from the airfoil surface, while the detached jet flow can block the development of the separation when it is placed on the trailing edge.
Economic assessment and comparative analysis of hydrogen transportation with various technical processes
Authors: Li Miao , Ming Pingwen , Huo Ran , Mu Hailin
Published: March 2023

This paper took hydrogen transportation as a breakthrough to make a comprehensive study on the economic assessments of hydrogen delivery pathways, so as to promote the low-cost and large-scale hydrogen energy development. A specific transportation model for gas-hydrogen trailers, liquid-hydrogen tank trucks, and hydrogen pipelines with various technical levels was developed to explore the cost reduction pathways. To verify the feasibility of the model, a case study was conducted in Shanghai, China, to obtain more realistic cost data. Accordingly, the gas-hydrogen trailer was found to be feasible for short distances, while the liquid-hydrogen tank truck was economic for long distances. By increasing the hydrogen storage pressure and liquefaction scale, the transportation cost of gas-hydrogen trailers and liquid-hydrogen tank trucks could be significantly reduced. However, their economic advantage could not surpass that of pipelines when its utilization rate is high. By improving the utilization rate of hydrogen pipelines, the transportation cost could be significantly reduced. In addition, we attempted to determine the more economical and feasible option between long-distance hydrogen transportation and local hydrogen production. With the large-scale utilization of renewable energy resources, only when the electricity price is reduced to approximately 0.1–0.2 yuan/kWh and hydrogen production efficiency is increased above 60%–80%, local hydrogen production can be more economical than long-distance hydrogen transportation.
Polarity-dependence of the nonlinear dielectric response in interfacial water
Authors: Mulpuri N. , Bratko D.
Published: March 2023

Molecular dynamics simulations are used to study the nonlinear dielectric responses of a confined aqueous film in a planar nanopore under perpendicular electric fields at varied voltages between confining graphene sheets. Dielectric saturation reminiscent of the bulk phase behavior is prevalent at very strong fields, whereas we observe a nonmonotonic permittivity dependence on the electric field at intermediate strengths where field-alignment and spontaneous polarization of interfacial water are of comparable magnitude. The coupling between the two effects results in distinct dielectric responses at opposite confinement walls. The normal component of both the differential dielectric constant and dielectric difference constant tensors averaged over the region closer to the wall under an incoming electric field (field pointing from the liquid to the solid phase) initially increases with the strength of the imposed field. The differential permittivity peaks at a field strength previously shown to offset the surface-induced orientation bias of hydration molecules at this wall. Further strengthening of the field results in a conventional saturation behavior. At the opposite wall (subject to outgoing field) and in the central region of the water slab, the nonlinear dielectric response resembles bulklike saturation. The conditions at the permittivity extremum coincide with the window of accelerated reorientation rates of interfacial water molecules under an incoming field we uncovered in earlier molecular dynamics analyses.
Identifying the dominant carrier of CdSe-based blue quantum dot light-emitting diode
Authors: Qu Xiangwei , Xiang Guohong , Ma Jingrui , Liu Pai , Kyaw Aung Ko Ko , Wang Kai , Sun Xiao Wei
Published: March 2023

Unlike red and green quantum dot light-emitting diodes (QLEDs), it is not clear whether a blue QLED is an electron-dominated device. In this work, we identify that electron is over-injected in blue QLEDs by impedance spectroscopy. By analyzing the capacitance–voltage characteristics of the single-carrier devices, we find that the built-in voltage of the electron-only device is smaller than that of the hole-only device. Therefore, electron injection is more efficient than hole injection in blue QLEDs. To support our arguments, we employ a red QD as a fluorescent sensor to spatially investigate the exciton recombination zone of a blue QLED. Consequently, we observe that the exciton recombination zone of the blue QLED is close to the hole transport layer, and it shifts toward an electron transport layer with the increase in the applied bias. Our work provides a practical method for identifying the excess carrier in blue QLEDs, and it could be applied to other types of QLEDs.
Solvent effects determine the sign of the charges of maximum entropy and capacitance at silver electrodes
Authors: Sundararaman Ravishankar , Schwarz Kathleen
Published: March 2023

Fully harnessing electrochemical interfaces for reactions requires a detailed understanding of solvent effects in the electrochemical double layer. Predicting the significant impact of solvents on entropic and electronic properties of electrochemical interfaces has remained an open challenge of computational electrochemistry. Using molecular dynamics simulations of silver–water and silver–acetonitrile interfaces, we show that switching the solvent changes the signs for both the charge of maximum capacitance (CMC) and charge of maximum entropy (CME). Contrasting the capacitance and CME behavior of these two interfaces, we demonstrate that the preferred orientation of the solvent molecule and the corresponding charge density determine the sign of the CMC and CME and, hence, the qualitatively different charge asymmetry of the electrochemical interface.
Non-normality and transient growth in stall flutter instability
Authors: Rangarajan Shreenivas , Tripathi Dheeraj , Venkatramani J.
Published: March 2023

The non-normal nature and transient growth in amplitude and energy of a pitch-plunge aeroelastic system undergoing dynamic stall are explored in this paper through numerical and supporting experimental studies. Wind tunnel experiments, carried out for a canonical pitch-plunge aeroelastic system in a subsonic wind tunnel, show that the system undergoes stall flutter instability via a sub-critical Hopf bifurcation. The aeroelastic responses indicate a transient growth in amplitude and energy—possibly triggering the sub-criticality, which is critical from the purview of structural safety. The system also shows transient energy growth followed by decaying oscillation for certain initial conditions, whereas sustained limit cycle oscillations are encountered for other initial conditions at flow speeds lower than the critical speed. The triggering behavior observed in the wind tunnel experiments is understood better by resorting to study the numerical model of the nonlinear aeroelastic system. To that end, a modified semi-empirical Leishman–Beddoes dynamic stall model is adopted to represent the nonlinear aerodynamic loads of the pitch-plunge aeroelastic system. The underlying linear operator and its pseudospectral analysis indicate that the aeroelastic system is non-normal, causing amplification in amplitude and energy for a short period.
Theoretical insights into the support effect on the NO activation over platinum-group metal catalysts
Authors: Zhao Pei , Ehara Masahiro
Published: March 2023

We systematically explored NO activation at metal/oxide interfaces by the combination of Sr3Ti2O7, Sr3Fe2O7, CeO2, anatase-TiO2, ZrO2, and γ-Al2O3 supports and the platinum-group metal cluster (Pd4, Pt4, and Rh4) using slab-model density functional theory calculations. These metal clusters can be strongly adsorbed at these metal oxide surfaces. The Pt4 and Rh4 clusters show larger adsorption energies than the Pd4 cluster, yet the γ-Al2O3(100) surface shows smaller adsorption energies than other metal oxide surfaces. One oxygen vacancy close to the metal cluster was constructed to evaluate the NO activation at those metal/oxide interfaces. The O atom of NO refills the oxygen vacancy after NO dissociation, while the N adatom is left on the metal cluster. The exothermic process was identified for the NO activation except for the Sr3Fe2O7 case, indicating the significant role of the interplay between the metal cluster and oxygen vacancy.
Persistence of gender biases in Europe
Authors: Damann Taylor J. , Siow Jeremy , Tavits Margit
Published: March 2023

Prior work suggests that modern gender bias might have historical roots but has not been able to demonstrate long-term persistence of this bias due to a lack of historical data. We follow archaeological research and employ skeletal records of women’s and men’s health from 139 archaeological sites in Europe dating back, on average, to about 1200 AD to construct a site-level indicator of historical bias in favor of one gender over the other using dental linear enamel hypoplasias. This historical measure of gender bias significantly predicts contemporary gender attitudes, despite the monumental socioeconomic and political changes that have taken place since. We also show that this persistence is most likely due to the intergenerational transmission of gender norms, which can be disrupted by significant population replacement. Our results demonstrate the resilience of gender norms and highlight the importance of cultural legacies in sustaining and perpetuating gender (in)equality today.
Structural basis and dynamics of Chikungunya alphavirus RNA capping by nsP1 capping pores
Authors: Jones Rhian , Hons Michael , Rabah Nadia , Zamarreño Noelia , Arranz Rocío , Reguera Juan
Published: March 2023

Alphaviruses are emerging positive-stranded RNA viruses which replicate and transcribe their genomes in membranous organelles formed in the cell cytoplasm. The nonstructural protein 1 (nsP1) is responsible for viral RNA capping and gates the replication organelles by assembling into monotopic membrane-associated dodecameric pores. The capping pathway is unique to Alphaviruses; beginning with the N
7
methylation of a guanosine triphosphate (GTP) molecule, followed by the covalent linkage of an m
7
GMP group to a conserved histidine in nsP1 and the transfer of this cap structure to a diphosphate RNA. Here, we provide structural snapshots of different stages of the reaction pathway showing how nsP1 pores recognize the substrates of the methyl-transfer reaction, GTP and S-adenosyl methionine (SAM), how the enzyme reaches a metastable postmethylation state with SAH and m
7
GTP in the active site, and the subsequent covalent transfer of m
7
GMP to nsP1 triggered by the presence of RNA and postdecapping reaction conformational changes inducing the opening of the pore. In addition, we biochemically characterize the capping reaction, demonstrating specificity for the RNA substrate and the reversibility of the cap transfer resulting in decapping activity and the release of reaction intermediates. Our data identify the molecular determinants allowing each pathway transition, providing an explanation for the need for the SAM methyl donor all along the pathway and clues about the conformational rearrangements associated to the enzymatic activity of nsP1. Together, our results set ground for the structural and functional understanding of alphavirus RNA-capping and the design of antivirals.
Superhuman artificial intelligence can improve human decision-making by increasing novelty
Authors: Shin Minkyu , Kim Jin , van Opheusden Bas , Griffiths Thomas L.
Published: March 2023

How will superhuman artificial intelligence (AI) affect human decision-making? And what will be the mechanisms behind this effect? We address these questions in a domain where AI already exceeds human performance, analyzing more than 5.8 million move decisions made by professional Go players over the past 71 y (1950 to 2021). To address the first question, we use a superhuman AI program to estimate the quality of human decisions across time, generating 58 billion counterfactual game patterns and comparing the win rates of actual human decisions with those of counterfactual AI decisions. We find that humans began to make significantly better decisions following the advent of superhuman AI. We then examine human players’ strategies across time and find that novel decisions (i.e., previously unobserved moves) occurred more frequently and became associated with higher decision quality after the advent of superhuman AI. Our findings suggest that the development of superhuman AI programs may have prompted human players to break away from traditional strategies and induced them to explore novel moves, which in turn may have improved their decision-making.
Freestanding lipid bilayer tensiometer for the study of mechanosensitive ion channels
Authors: Pérez-Mitta Gonzalo , MacKinnon Roderick
Published: March 2023

Mechanical forces modify the cell membrane potential by opening mechanosensitive ion channels. We report the design and construction of a lipid bilayer tensiometer to study channels that respond to lateral membrane tension,

γ

 , in the range 0.2 to 1.4

k
B

T

nm

2

(0.8 to 5.7

mN

m

 ). The instrument consists of a black-lipid-membrane bilayer, a custom-built microscope, and a high-resolution manometer. Values of

γ

are obtained from the determination of the bilayer curvature as a function of applied pressure by means of the Young–Laplace equation. We demonstrate that

γ

can be determined by calculating the bilayer radius of curvature from fluorescence microscopy imaging or from measurements of the bilayer’s electrical capacitance, both yielding similar results. Using electrical capacitance, we show that the mechanosensitive potassium channel TRAAK responds to

γ

 , not curvature. TRAAK channel open probability increases as

γ

is increased from 0.2 to 1.4

k
B

T

nm

2

but open probability never reaches 0.5. Thus, TRAAK opens over a wide range of

γ

 , but with a tension sensitivity about one-fifth that of the bacterial mechanosensitive channel MscL.
Blockade of TRPV channels by intracellular spermine
Authors: Maksaev Grigory , Yuan Peng , Nichols Colin G.
Published: March 2023

The Vanilloid thermoTRP (TRPV1–4) subfamily of TRP channels are involved in thermoregulation, osmoregulation, itch and pain perception, (neuro)inflammation and immune response, and tight control of channel activity is required for perception of noxious stimuli and pain. Here we report voltage-dependent modulation of each of human TRPV1, 3, and 4 by the endogenous intracellular polyamine spermine. As in inward rectifier K channels, currents are blocked in a strongly voltage-dependent manner, but, as in cyclic nucleotide-gated channels, the blockade is substantially reduced at more positive voltages, with maximal blockade in the vicinity of zero voltage. A kinetic model of inhibition suggests two independent spermine binding sites with different affinities as well as different degrees of polyamine permeability in TRPV1, 3, and 4. Given that block and relief occur over the physiological voltage range of action potentials, voltage-dependent polyamine block may be a potent modulator of TRPV-dependent excitability in multiple cell types.
Calculation method for the conductance of mesoscopic systems: assembly of Tight Binding Hamiltonians with spin effects—revisited
Authors: Silva Felipe E F , Mendoza Michel
Published: March 2023

We discretize the Schrödinger equation in the approximation of the effective mass for the two-dimensional electron gas of GaAs, without magnetic field and on the other hand, with magnetic field. This discretization leads naturally to Tight Binding (TB) Hamiltonians in the approximation of the effective mass. An analysis of this discretization allows us to gain insight into the role of site and hopping energies, which allows us to model the TB Hamiltonian assembly with spin: Zeeman and spin–orbit coupling effects, especially the case Rashba. With this tool we can assemble Hamiltonians of quantum boxes, Aharanov–Bohm interferometers, anti-dots lattices and effects of imperfections, as well as disorder in the system. The extension to mount quantum billiards is natural. We also explain here how to adapt the recursive equations of Green’s functions for the case of spin modes, apart from transverse modes, for the calculation of conductance in these mesoscopic systems. The assembled Hamiltonians allow to identify the matrix elements (depending on the different parameters of the system) associated with splitting or spin flipping, which gives a starting point to model specific systems of interest, manipulating certain parameters. In general, the approach of this work allows us to clearly see the relationship between the wave and matrix description of quantum mechanics. We discuss here also, the extension of the method for 1D and 3D systems, for the extension apart from the first neighbors and for the inclusion of other types of interaction. The way we approach the method, has the objective of showing how specifically the site and hopping energies change in the presence of new interactions. This is very important in the case of spin interactions, because by looking at the matrix elements (site or hopping) we can directly identify the conditions that can lead to splitting, flipping or a mixture of these effects. Which is essential for the design of devices based on spintronics. Finally, we discuss spin-conductance modulation (Rashba spin precession) for the states of an open quantum dot (resonant states). Unlike the case of a quantum wire, the spin-flipping observed in the conductance is not perfectly sinusoidal, there is an envelope that modulates the sinusoidal component, which depends on the discrete-continuous coupling of the resonant states.
Adaptive threshold event detection method based on standard deviation
Authors: Pan Guobing , Qian Junjie , Ouyang Jing , Luo Yuhan , Wang Haipeng
Published: March 2023

Event detection is the foundation of event-based non-intrusive load detection solutions. Conventional event detection methods require a comprehensive consideration of the rated power levels of all devices within the detection scenario to define an appropriate threshold value. However, it cannot accurately detect both high- and low-power load events because of their fixed thresholds when loads with widely varying power change amplitudes are present simultaneously. Thus, an adaptive threshold event detection method based on standard deviation is proposed in this study. First, the aggregated power data are intercepted by a sliding window for a short period of time, and the standard deviation is calculated for the aggregated power data within the window. The event ends when the standard deviation reaches its maximum value. Next, the threshold for event detection is calculated based on the standard deviation, and event detection based on the calculated threshold and on the bilateral sliding window cumulative sum method is performed. Finally, various load tests are performed with Electricity Consumption & Occupancy (Kleiminger et al 2015 Proc. 2015 ACM Int. Joint Conf. on Pervasive and Ubiquitous Computing) datasets and private datasets. The F1 values exceeded 90% in all three scenarios, namely, office, factory and laboratory, indicating that the proposed method in this study has high event detection performance.
A novel hybrid distance guided domain adversarial method for cross domain fault diagnosis of gearbox
Authors: Jiang Xingwang , Wang Xiaojing , Han Baokun , Wang Jinrui , Zhang Zongzhen , Ma Hao , Xing Shuo , Man Kai
Published: March 2023

Distance-based domain adaptation methods have received extensive application in the transfer learning field. Different domain distances have different characteristics due to various data processing principles. Therefore, choosing appropriate domain distance can accomplish transfer tasks more efficiently. Domain adversarial neural networks can extract domain invariant features through game confrontation, but it is not capable of extracting hidden features of gear under speed fluctuations, and only using the adversarial mechanism for domain feature alignment is prone to gradient collapse. To solve the above problems, a novel hybrid distance guided domain adversarial fault diagnosis method of gear is proposed. First, stacked sparse autoencoders is employed in the model to extract the hidden features from the domain data, and the extracted features are input into the corresponding feature classifier and domain discriminator. Then, a mixture of maximum mean discrepancy (MMD) and Wasserstein distance is utilized to reduce the distribution difference. Finally, the domain adversarial mechanism is used to conduct adversarial training for feature alignment. Through two verification experiments of planetary gearboxes, it is verified that the proposed a Wasserstein and MMD distance guided Domain Adversarial model has excellent fault diagnosis performance under gear fluctuating conditions. In addition, the model has higher prediction accuracy and better fault feature extraction ability compared with other methods.
The PETcoil project: PET performance evaluation of two detector modules for a second generation RF-penetrable TOF-PET brain dedicated insert for simultaneous PET/MRI
Authors: Dong Qian , Chang Chen-Ming , Lee Brian J , Sacco Ilaria , Sajedi Salar , Adams Zander , Fischer Peter , Levin Craig S
Published: March 2023

Objective. We are developing a portable, ‘RF-penetrable’, brain-dedicated time of flight (TOF)-PET insert (PETcoil) for simultaneous PET/MRI. Approach. In this paper, we evaluate the PET performance of two fully assembled detector modules for this insert design outside the MR room. Main results. The global coincidence time resolution, global 511 keV energy resolution, coincidence count rate, and detector temperature achieved over 2 h data collection were 242.2 ± 0.4 ps full width at half maximum (FWHM), 11.19% ± 0.02% FWHM, 22.0 ± 0.1 kcps, and 23.5 °C ± 0.3 °C, respectively. The intrinsic spatial resolutions in the axial and transaxial directions were 2.74 ± 0.01 mm FWHM and 2.88 ± 0.03 mm FWHM, respectively. Significance. These results demonstrate excellent TOF capability and the performance and stability necessary for scaling up to a full ring comprising 16 detector modules.
Ag NPs and MoS2 QDs double modified graphene/GaAs near-infrared photodetector
Authors: Qu Jiaqi , Chen Jun
Published: March 2023

The light absorption enhancement ability of quantum dots (QDs) and the localized surface plasmon resonance (LSPR) effect of metal nanoparticles (NPs) can effectively improve the performance of photodetectors. In this paper, an Ag NPs and MoS2 QDs double modified graphene/GaAs near-infrared photodetector is investigated. The performance of the detector is improved by adopting the LSPR effect of Ag NPs and the dielectric confinement effect of MoS2 QDs. After subsequent testing and analysis, the photodetector responsivity is 21.1 mA W−1 and the detectivity is 8.4 × 1012 cm Hz1/2 W−1 at 808 nm wavelength; the responsivity and detectivity at 1064 nm wavelength can be up to 18.4 mA W−1 and 3.39 × 1012 cm Hz1/2 W−1, respectively. At the same time, under a 4 kHz pulsed illumination, the rise time and fall time are 15.87 μs and 89.95 μs respectively. Compared with previous devices, the new device has lower dark current and higher detectivity while having good responsivity and response time.
Design and fabrication of NiTi shape memory alloy/aramid composite fabric for thermal protective clothing
Authors: Pan Mengjiao , Wang Lijun , Lu Yehu , Xu Jingxian , Liu Suyan
Published: March 2023

Developing fabrics with enhanced thermal protection is a cutting-edge topic in area of thermal protective clothing (TPC) for workers under heat hazards. Here, temperature-responsive NiTi shape memory alloy (SMA) filaments, which transform into a sinusoid form under a stimulus of temperature exceeding their austenite start temperature of 45.1 °C, were prepared. Nine composite fabrics (CFs) using SMA filaments and aramid yarns, different in filament interval, air gap orientation, aramid yarn type and fabric density, were fabricated and incorporated into traditional three-layer TPC fabric system, resulting in a four-layer smart fabric system (SFS) with adaptive structure. Thermal protective performance (TPP) tests demonstrated the addition of CF could significantly slow down the rise of temperature at skin surface and prolong the time to the first-degree burn. With the decrease of filament interval or increase of fabric density, TPP of SFS was improved due to more heat accumulation within and less heat conduction through the fabric. This study would inspire engineering CFs with enhanced TPP, thus pushing forward the development of smart technology in textile engineering.
A novel compact bolted-type piezoelectric actuator excited by two excitation methods: design, simulation, and experimental investigation
Authors: Liu Zhen , Fu Qianwei , Wang Hao , Yao Zhiyuan , Dong Zhiyan , Zhang Lihua
Published: March 2023

A novel bolted-type piezoelectric actuator excited by two excitation methods was proposed and investigated in this paper using both simulations and experiments. Different from most existing piezoelectric actuators, the proposed actuator can be excited by two different excitation methods, namely single-phase excitation method and dual-phase excitation method. The structure of the actuator was depicted and its geometric dimensions were presented. Furthermore, the working principles of the proposed actuator under these methods were illustrated in detail, and the vibration characteristics of the driving foot were analyzed using the finite element method. In addition, a prototype was fabricated and an experimental system was set up to evaluate the output performance of the prototype. The experimental results indicated that the actuator achieved a maximum velocity of 483.7 mm s−1 and a maximum thrust of 3.4 kg with dual-phase excitation, and a maximum velocity of 284.6 mm s−1 and a maximum thrust of 2.2 kg with single-phase excitation.
Comparison of Different Tidal Disruption Event Light Curve Models with TiDE, a New Modular Open Source Code
Authors: Kovács-Stermeczky Zsófia V. , Vinkó József
Published: March 2023

A tidal disruption event (TDE) occurs when a supermassive black hole disrupts a nearby passing star by tidal forces. The subsequent fallback accretion of the stellar debris results in a luminous transient outburst. Modeling the light curve of such an event may reveal important information, for example the mass of the central black hole. This paper presents the TiDE software based on semi-analytic modeling of TDEs. This object-oriented code contains different models for the accretion rate and the fallback timescale

t

min

. We compare the resulting accretion rates to each other and with hydrodynamically simulated ones and find convincing agreement for full disruptions. We present a set of parameters estimated with TiDE for the well-observed TDE candidate AT2019qiz, and compare our results with those given by the MOSFiT code. Most of the parameters are in reasonable agreement, except for the mass and the radiative efficiency of the black hole, both of which depend heavily on the adopted fallback accretion rate.
Suspension bath bioprinting and maturation of anisotropic meniscal constructs
Authors: Prendergast Margaret E , Heo Su-Jin , Mauck Robert L , Burdick Jason A
Published: March 2023

Due to limited intrinsic healing capacity of the meniscus, meniscal injuries pose a significant clinical challenge. The most common method for treatment of damaged meniscal tissues, meniscectomy, leads to improper loading within the knee joint, which can increase the risk of osteoarthritis. Thus, there is a clinical need for the development of constructs for meniscal repair that better replicate meniscal tissue organization to improve load distributions and function over time. Advanced three-dimensional bioprinting technologies such as suspension bath bioprinting provide some key advantages, such as the ability to support the fabrication of complex structures using non-viscous bioinks. In this work, the suspension bath printing process is utilized to print anisotropic constructs with a unique bioink that contains embedded hydrogel fibers that align via shear stresses during printing. Constructs with and without fibers are printed and then cultured for up to 56 d in vitro in a custom clamping system. Printed constructs with fibers demonstrate increased cell and collagen alignment, as well as enhanced tensile moduli when compared to constructs printed without fibers. This work advances the use of biofabrication to develop anisotropic constructs that can be utilized for the repair of meniscal tissue.
Appealing but a cheat: choice of attractive but sick males reduces the fitness of females
Authors: Ensaldo-Cárdenas Angelica S , Rocha-Ortega Maya , Córdoba-Aguilar Alex
Published: March 2023

One central tenet in sexual selection theory is that sexual traits are honest indicators of individual condition. This does not appear to be the case for Tenebrio molitor beetles whose males, when infected with the fungus Metarhizium robertsii, produce chemical signals (pheromones) that increase their attractiveness. Using this system, we have investigated the consequences of non-adaptive female choice with regard to: (a) survival of females in choosing fungus-infected males; and (b) whether the number and duration of copulations increases fungal infection in females. Females that mated with fungus-infected males lived half as long as females that mated with infection-free males. In addition, the greater the number and the longer the duration of copulation(s), the greater the fungal sporulation in females, suggesting that the fungus may be mainly transmitted during copulation. This study documents a conflict between the sexes: while the dishonesty of a sexual signal increases male fitness, it reduces female fitness.
The effect of GLP-1RA exenatide on idiopathic intracranial hypertension: a randomized clinical trial
Authors: Mitchell James L , Lyons Hannah S , Walker Jessica K , Yiangou Andreas , Grech Olivia , Alimajstorovic Zerin , Greig Nigel H , Li Yazhou , Tsermoulas Georgios , Brock Kristian , Mollan Susan P , Sinclair Alexandra J
Published: March 2023

Therapeutics to reduce intracranial pressure are an unmet need. Preclinical data have demonstrated a novel strategy to lower intracranial pressure using glucagon-like peptide-1 (GLP-1) receptor signalling.

Here, we translate these findings into patients by conducting a randomized, placebo-controlled, double-blind trial to assess the effect of exenatide, a GLP-1 receptor agonist, on intracranial pressure in idiopathic intracranial hypertension. Telemetric intracranial pressure catheters enabled long-term intracranial pressure monitoring. The trial enrolled adult women with active idiopathic intracranial hypertension (intracranial pressure >25 cmCSF and papilloedema) who receive subcutaneous exenatide or placebo. The three primary outcome measures were intracranial pressure at 2.5 h, 24 h and 12 weeks and alpha set a priori at less than 0.1.

Among the 16 women recruited, 15 completed the study (mean age 28 ± 9, body mass index 38.1 ± 6.2 kg/m2, intracranial pressure 30.6 ± 5.1 cmCSF). Exenatide significantly and meaningfully lowered intracranial pressure at 2.5 h −5.7 ± 2.9 cmCSF (P = 0.048); 24 h −6.4 ± 2.9 cmCSF (P = 0.030); and 12 weeks −5.6 ± 3.0 cmCSF (P = 0.058). No serious safety signals were noted.

These data provide confidence to proceed to a phase 3 trial in idiopathic intracranial hypertension and highlight the potential to utilize GLP-1 receptor agonist in other conditions characterized by raised intracranial pressure.
Efficacy of levosimendan infusion in patients undergoing a left ventricular assist device implant in a propensity score matched analysis of the EUROMACS registry—the Euro LEVO-LVAD study
Authors: Abdelshafy Mahmoud , Caliskan Kadir , Simpkin Andrew J , Elkoumy Ahmed , Kimman Jesse R , Elsherbini Hagar , Elzomor Hesham , de By Theo M M H , Gollmann-Tepeköylü Can , Berchtold-Herz Michael , Loforte Antonio , Reineke David , Schoenrath Felix , Paluszkiewicz Lech , Gummert Jan , Mohacsi Paul , Meyns Bart , Soliman Osama
Published: March 2023

OBJECTIVES

Early right-sided heart failure (RHF) was seen in 22% of recipients of a left ventricular assist device (LVAD) in the European Registry for Patients with Mechanical Circulatory Support (EUROMACS). However, the optimal treatment of post-LVAD RHF is not well known. Levosimendan has proven to be effective in patients with cardiogenic shock and in those with end-stage heart failure. We sought to evaluate the efficacy of levosimendan on post-LVAD RHF and 30-day and 1-year mortality.

METHODS

The EUROMACS Registry was used to identify adults with mainstream continuous-flow LVAD implants who were treated with preoperative levosimendan compared to a propensity matched control cohort.

RESULTS

In total, 3661 patients received mainstream LVAD, of which 399 (11%) were treated with levosimendan pre-LVAD. Patients given levosimendan had a higher EUROMACS RHF score [4 (2– 5.5) vs 2 (2– 4); P < 0.001], received more right ventricular assist devices (RVAD) [32 (8%) vs 178 (5.5%); P = 0.038] and stayed longer in the intensive care unit post-LVAD implant [19 (8–35) vs 11(5–25); P < 0.001]. Yet, there was no significant difference in the rate of RHF, 30-day, or 1-year mortality. Also, in the matched cohort (357 patients taking levosimendan compared to an average of 622 controls across 20 imputations), we found no evidence for a difference in postoperative severe RHF, RVAD implant rate, length of stay in the intensive care unit or 30-day and 1-year mortality.

CONCLUSIONS

In this analysis of the EUROMACS registry, we found no evidence for an association between levosimendan and early RHF or death, albeit patients taking levosimendan had much higher risk profiles. For a definitive conclusion, a multicentre, randomized study is warranted.
Study on the optimization strategy of offshore wind power
Authors: Wang Jing , Wei Xiongfei , Juanatas Ronaldo
Published: March 2023

Offshore wind power is considered a promising renewable energy source; unfortunately, its weighted average levelized cost of electricity is still too high to compete with renewable energies such as photovoltaics. This is in large part due to the high construction cost of offshore wind power, even though it has fallen substantially with technological advances and the accumulation of experience. This paper optimizes the cost from two aspects. Because large-scale wind farms have better bargaining and scheduling power, we analyse in detail the relationship between the cost of different key components and the scale of the wind farm, and if the decommissioned wind farm chooses to repower, costs such as cables and foundations can be saved, which can further reduce the costs. Our studies show that compared with a 400-MW offshore wind farm, 1000 MW can reduce the unit cost by ~10.3%, and its cost is ~13 239 RMB/kW. If repowering is chosen, there is a further reduction of ~28.6%, and its cost is ~9450 RMB/kW. We recommend using larger offshore wind farms and choosing repowering after they are decommissioned to get better economics.
Phase synchronization of epicyclic motion due to gravitational scattering by wakes
Authors: Yoshida Yuki , Kokubo Eiichiro
Published: March 2023

The swing amplification is one of the mechanisms for spiral arm formation and gravitational scattering of stellar orbits by a high-density region in a disc galaxy is considered as its elementary process. During the swing amplification, the epicycle phases of stars are synchronized. We previously showed that gravitational scattering by a softened point mass can synchronize the epicycle phases. Here, we expand upon our previous work to consider gravitational scattering by a finite-sized wake, which we model by using a prolate body. We numerically simulate the stellar motion under the influence of the wake gravity, and we investigate the dependence of the orbital evolution on the wake properties. We find that phase synchronization is more effective for a wake with a pitch angle around π/2, and that the phase synchronization depends on the wake shape. Even for realistic pitch angles i ≲ π/4 the phase synchronization can be more effective than that by the softened point mass. Increasing the impact parameter of stars and decreasing the wake pitch angle are shown to increase the axis ratio at which synchronization occurs. Linear trailing high-density patterns form around the wake and enlarge the wake itself.
Structural basis of a two-step tRNA recognition mechanism for plastid glycyl-tRNA synthetase
Authors: Yu Zhaoli , Wu Zihan , Li Ye , Hao Qiang , Cao Xiaofeng , Blaha Gregor M , Lin Jinzhong , Lu Guoliang
Published: March 2023

Two types of glycyl-tRNA synthetase (GlyRS) are known, the α2 and the α2β2 GlyRSs. Both types of synthetase employ a class II catalytic domain to aminoacylate tRNAGly. In plastids and some bacteria, the α and β subunits are fused and are designated as (αβ)2 GlyRSs. While the tRNA recognition and aminoacylation mechanisms are well understood for α2 GlyRSs, little is known about the mechanisms for α2β2/(αβ)2 GlyRSs. Here we describe structures of the (αβ)2 GlyRS from Oryza sativa chloroplast by itself and in complex with cognate tRNAGly. The set of structures reveals that the U-shaped β half of the synthetase selects the tRNA in a two-step manner. In the first step, the synthetase engages the elbow and the anticodon base C35 of the tRNA. In the second step, the tRNA has rotated ∼9° toward the catalytic centre. The synthetase probes the tRNA for the presence of anticodon base C36 and discriminator base C73. This intricate mechanism enables the tRNA to access the active site of the synthetase from a direction opposite to that of most other class II synthetases.
PML and PML-like exonucleases restrict retrotransposons in jawed vertebrates
Authors: Mathavarajah Sabateeshan , Vergunst Kathleen L , Habib Elias B , Williams Shelby K , He Raymond , Maliougina Maria , Park Mika , Salsman Jayme , Roy Stéphane , Braasch Ingo , Roger Andrew J , Langelaan David N , Dellaire Graham
Published: March 2023

We have uncovered a role for the promyelocytic leukemia (PML) gene and novel PML-like DEDDh exonucleases in the maintenance of genome stability through the restriction of LINE-1 (L1) retrotransposition in jawed vertebrates. Although the mammalian PML protein forms nuclear bodies, we found that the spotted gar PML ortholog and related proteins in fish function as cytoplasmic DEDDh exonucleases. In contrast, PML proteins from amniote species localized both to the cytoplasm and formed nuclear bodies. We also identified the PML-like exon 9 (Plex9) genes in teleost fishes that encode exonucleases. Plex9 proteins resemble TREX1 but are unique from the TREX family and share homology to gar PML. We also characterized the molecular evolution of TREX1 and the first non-mammalian TREX1 homologs in axolotl. In an example of convergent evolution and akin to TREX1, gar PML and zebrafish Plex9 proteins suppressed L1 retrotransposition and could complement TREX1 knockout in mammalian cells. Following export to the cytoplasm, the human PML-I isoform also restricted L1 through its conserved C-terminus by enhancing ORF1p degradation through the ubiquitin-proteasome system. Thus, PML first emerged as a cytoplasmic suppressor of retroelements, and this function is retained in amniotes despite its new role in the assembly of nuclear bodies.
Multi-task learning from multimodal single-cell omics with Matilda
Authors: Liu Chunlei , Huang Hao , Yang Pengyi
Published: March 2023

Multimodal single-cell omics technologies enable multiple molecular programs to be simultaneously profiled at a global scale in individual cells, creating opportunities to study biological systems at a resolution that was previously inaccessible. However, the analysis of multimodal single-cell omics data is challenging due to the lack of methods that can integrate across multiple data modalities generated from such technologies. Here, we present Matilda, a multi-task learning method for integrative analysis of multimodal single-cell omics data. By leveraging the interrelationship among tasks, Matilda learns to perform data simulation, dimension reduction, cell type classification, and feature selection in a single unified framework. We compare Matilda with other state-of-the-art methods on datasets generated from some of the most popular multimodal single-cell omics technologies. Our results demonstrate the utility of Matilda for addressing multiple key tasks on integrative multimodal single-cell omics data analysis. Matilda is implemented in Pytorch and is freely available from https://github.com/PYangLab/Matilda.