bluuebunny/crossref_metadata_2025 huggingface dataset:
Triisobutylaluminium-Mediated Regioselective Protection of Sterically Hindered Amide NH of Cyclo-(AA-Gly): Key Building Block for Next-Generation Peptide Synthesis
Authors: Ramakrishna Isai , Hattori Tomohiro , Yamamoto Hisashi , Ishiguro Tomomi
Published: November 2023

In this study, we address the challenge of regioselective Boc protection in the more sterically hindered amide NH of unsymmetrical 2,5-diketopiperazines (DKPs) formed from glycine and various amino acids. Our research introduces a novel technique utilizing cost-effective triisobutylaluminium and trimethoxysilane. Notably, trimethoxysilane selectively reacts with the less hindered amide NH, facilitating the regioselective Boc protection of the more congested amide NH in DKPs. The primary objective of our work is to develop a straightforward and scalable approach for the synthesis of Boc-protected DKPs, with a focus on addressing the steric challenges presented by these compounds. We successfully demonstrate the scalability of this method, enabling the synthesis of a variety of mono-Fmoc-, Cbz-, Alloc-, and EtOCO-protected DKPs. Furthermore, we extend the applicability of this strategy by employing it in the construction of pentapeptides through a twofold peptide-elongation process. Our findings reveal the versatility and efficiency of this regioselective Boc-protection method. Overall, this research introduces a valuable solution to the regioselective Boc-protection challenge in DKPs and demonstrates its applicability in peptide synthesis, showcasing its potential for further advancements in the field.
A Novel Route towards Bicyclo[1.1.1]pentane Sulfoxides from a Bench-Stable Starting Material
Authors: Bräse Stefan , Langer Lukas S. , Stahlberger Mareen , Bär Robin M.
Published: November 2023

Bicyclopentanes (BCPs) are non-classical bioisosteres that have gained a lot of interest in drug discovery as non-conjugated rigid hydrocarbons. There has been substantial progress in the synthesis of carbon- and nitrogen-substituted derivatives using [1.1.1]propellane as a precursor, while sulfur-substituted BCPs are rather underdeveloped. This work investigates a new method for the synthesis of BCP-sulfoxides. Herein, a previously reported bench-stable sodium BCP-sulfinate precursor is converted, using a range of aryl and alkyl magnesium bromides, into unsymmetrical BCP-sulfoxides via a convenient one-pot procedure. Furthermore, the conversion of the obtained sulfoxides into sulfoximines is explored.
Risk Factors Analysis of Severe Liver Injury Induced by
Statins
Authors: Su Feng-yun , Li Wen-hua , Zhao Xu-dong , Han Qian , Xu Xin , Geng Tao
Published: November 2023

The aim of this study is to report the risk factors of severe statin induced
liver injury (SILI). From the database of Shandong ADR Monitoring Center and
Outpatients and inpatients in our hospital, SILI cases reported from 2013 to
2021 were extracted and screened. The diagnostic criteria of SILI, the inclusion
and exclusion criteria of severe and general SILI were established separately.
After the SILI cases were selected and confirmed, the socio-demographic and
clinical characteristics were collected. Single factor chi-square test and
multi-factor unconditional logistic regression analysis were used to analyze the
influencing factors of severe SILI. From 1391 reported cases, 1211 met SILI
diagnostic criteria, of which 157 were severe SILI and 964 were general SILI.
Univariate analysis showed that age, drug combination, statin category were the
influencing factors of severe SILI (p<0.1). Multivariate logistic
analysis showed that drug combination and statin category were the influencing
factors of severe SILI (p<0.05). Atorvastatin caused the most serious
SILI, and its risk is 1.77 times higher than rosuvastatin. The serious SILI risk
of drug combination was 2.08 times higher than statin alone. The patient with
these factors should be monitored intensively during clinical treatment, to
ensure their medication safety.
Two sides of the same coin? Examining the interrelation between the proposed new human right and the law governing outer space
Authors: Ramuš Cvetkovič Iva
Published: November 2023

The basis of the law governing outer space was set out more than fifty years ago, but the nature of space activities has dramatically changed over the years. The increasing involvement of non-state actors, the concerning amount of space debris in orbit, the extensive use of space technology in modern warfare and several other factors have demonstrated the shortcomings of the existing legal framework. Despite the fact that these factors pose a severe threat to the health and lives of humans, they have not yet been properly regulated. In order to contribute to a better protection of these values, more concrete rules will need to be adopted. One way to achieve a greater protection of the health and lives of humans is the proposed new human right, based upon hearings before the Airspace Tribunal, aimed at protecting the freedom to live without physical or psychological threat from above. In this paper, I seek to examine the interrelation between the proposed human right and the law governing outer space. I examine, on one hand, whether the existing legal framework offers a basis for the establishment of the new human right, and on the other hand, whether the proposed human right carries potential relevance for further developments and improvements of space law.
Stability of 2D inviscid MHD equations with only vertical magnetic diffusion on T2
Authors: Zheng Yiming , Zhu Yi
Published: November 2023

Physical experiments and numerical simulations have observed a remarkable phenomenon that a background magnetic field can smooth and stabilize the electrically conducting turbulent fluids. To understand the mechanism of this phenomenon, we will focus on a special 2D magnetohydrodynamic (MHD) system with no viscosity and partial magnetic resistive and examine the stability near a background magnetic field. Due to the lack of dissipation for velocity field, this stability problem is not trivial. Without the presence of a magnetic field, the fluid velocity is governed by the 2D incompressible Euler equation. And it is well known that solutions to the 2D incompressible Euler equation can grow rather rapidly. Our result in this paper then shows the stabilization effect of magnetic filed for conductive fluids. By coupling a suitable magnetic filed, we can obtain the uniform upper bound of solutions. Moreover, we will derive the exponentially decay of solutions on one direction. The approach is based on delicate energy estimate together with some observations such as Poincáre’s inequality in one direction and cancellation structure.
Pair production in an electron collision with a radially polarized laser pulse
Authors: Jirka M. , Kadlecová H.
Published: November 2023

Using 3D numerical simulations, we show that in the collision of an electron with a counter-propagating laser beam, the radial polarization of the laser pulse leads to more efficient electron–positron pair production via multiphoton Breit–Wheeler process compared to the linearly polarized one having the same energy, duration, and amplitude. The reason is that in the case of the radially (or azimuthally) polarized laser pulse, the area of a strong field region is greater than that in the case of a linear one. As a consequence, more electrons experience a strong field region with sufficient energy, that, in turn, results in a higher number of created electron–positron pairs.
Epitaxial-orientation-controlled magnetic anisotropy in the La0.67Sr0.33MnO3/SrTiO3 heterostructures
Authors: Xu C. C. , Dai S. , Huang J. W. , Yin C. Y. , Wang J. J. , Xu Z. P. , Du Y. Y. , Xu L. Q. , Han K. , Yu X. J. , Wu W. B. , Chen P. F. , Huang Z.
Published: November 2023

Magnetic anisotropy has significant importance in both designing high-efficiency magnetic devices and understanding noncollinear spin textures. Here, La0.67Sr0.33MnO3 layers are epitaxially fabricated on the (001)-, (110)-, and (111)-orientated SrTiO3 substrates to manipulate magnetic anisotropy. While the [11¯0] axis is the in-plane magnetic easy axis for the (001) La0.67Sr0.33MnO3 layer, it becomes the hard axis for the (110) and (111) samples. Interestingly, the (110) samples exhibit a great enhancement in magnetic anisotropy energy, reaching at 6.1 × 105 erg/cm3 that is 1–2 orders of magnitude higher than ones in (001) and (111) films. It is also noted that such improved magnetic anisotropy of (110) samples is maintained up to 30 nm. Those observations can be interpreted in terms of the orientation-modified orbital symmetry. While the energetically favored 3dx2−y2 orbital and degenerated eg orbitals drive the two-dimensional and bulk-like ferromagnetism in (001) and (111) La0.67Sr0.33MnO3 layers, respectively, the 3d3z2−r2 orbital provides the lowest orbital symmetry and results in the highest magnetic anisotropy energy in (110) samples. Meanwhile, this model can also explain the thickness-dependent Curie temperatures with different epitaxial orientations, deepening the understanding of the complex oxide heterostructures for magnetic modulations.
Separation delay in turbulent boundary layers via model predictive control of large-scale motions
Authors: Tsolovikos Alexandros , Jariwala Akshit , Suryanarayanan Saikishan , Bakolas Efstathios , Goldstein David
Published: November 2023

Turbulent boundary layers are dominated by large-scale motions (LSMs) of streamwise momentum surplus and deficit that contribute significantly to the statistics of the flow. In particular, the high-momentum LSMs residing in the outer region of the boundary layer have the potential to re-energize the flow and delay separation if brought closer to the wall. This work explores the effect of selectively manipulating LSMs in a moderate Reynolds number turbulent boundary layer for separation delay via well-resolved large-eddy simulations. Toward that goal, a model predictive control scheme is developed based on a reduced-order model of the flow that directs LSMs of interest closer to the wall in an optimal way via a body force-induced downwash. The performance improvement achieved by targeting LSMs for separation delay, compared to a naive actuation scheme that does not account for the presence of LSMs, is demonstrated.
A fully Eulerian two-layer model for the simulation of oil spills spreading over coastal flows
Authors: Echeverribar I. , Brufau P. , García-Navarro P.
Published: November 2023

Nowadays, the vast majority of coastal oil spill simulation models are based on Lagrangian methods focused on particle tracking algorithms to represent the oil slick fate. In this work, a fully Eulerian numerical model for the simulation of such environmentally significant disaster is implemented by means of a two-dimensional two-layer shallow water model. A very thin oil layer over a thicker water layer is considered in order to neglect the pressure term that the oil layer exerts over the water. Friction terms between layers are responsible for the layers coupling so that the oil layer flows over a moving water volume. To complete this dynamic model, the temperature transport and evolution under heat exchange for the oil upper layer is considered and the weathering process of evaporation is included. The numerical solution adopted is based on a finite volume upwind scheme with a Roe solver for both oil and water layers. Special care has been taken on the numerical treatment of the two-layer wet-dry boundaries (oil–water–land) and friction terms, since the objective of the model is to compute the oil slick front advancing near the coast.
On a plasma sheath with a small normal magnetic field separating regions of oppositely directed magnetic field
Authors: Egedal Jan
Published: November 2023

The Harris-sheet model provides an elegant solution to the kinetic plasma equation for a steady state 1D current sheet geometry separating regions with oppositely directed magnetic field. However, adding just a small normal magnetic field to the Harris configuration yields thermal streaming of particles into and out of the current sheet, fundamentally changing the form of its kinetic description. The action variable, Jz, associated with the oscillatory orbit motion perpendicular to the current sheet is well conserved and can be applied for solving the kinetic equation in the 1D sheet geometry that includes a small normal magnetic field. Revisiting this problem, we develop a new formalism that permits numerical solutions to be readily obtained for general upstream/asymptotic electron and ion distributions. In particular, we consider the case of isotropic ion pressure and anisotropic bi-Maxwellian electrons. The current sheets are then supported by electron pressure anisotropy. Furthermore, the total current across a particular sheet is set by the fire-hose condition based on the electron pressures normalized by the asymptotic magnetic field pressure. Analytical approximations are obtained for the numerical solutions expressed in terms of the asymptotic electron temperature anisotropy and the ion temperature. We discuss a preliminary application of the framework to the electron diffusion region of anti-parallel magnetic reconnection.
First-principles simulation of excitation energy transfer and transient absorption spectroscopy in the CP29 light-harvesting complex
Authors: Saraceno Piermarco , Sláma Vladislav , Cupellini Lorenzo
Published: November 2023

The dynamics of delocalized excitons in light-harvesting complexes (LHCs) can be investigated using different experimental techniques, and transient absorption (TA) spectroscopy is one of the most valuable methods for this purpose. A careful interpretation of TA spectra is essential for the clarification of excitation energy transfer (EET) processes occurring during light-harvesting. However, even in the simplest LHCs, a physical model is needed to interpret transient spectra as the number of EET processes occurring at the same time is very large to be disentangled from measurements alone. Physical EET models are commonly built by fittings of the microscopic exciton Hamiltonians and exciton-vibrational parameters, an approach that can lead to biases. Here, we present a first-principles strategy to simulate EET and transient absorption spectra in LHCs, combining molecular dynamics and accurate multiscale quantum chemical calculations to obtain an independent estimate of the excitonic structure of the complex. The microscopic parameters thus obtained are then used in EET simulations to obtain the population dynamics and the related spectroscopic signature. We apply this approach to the CP29 minor antenna complex of plants for which we follow the EET dynamics and transient spectra after excitation in the chlorophyll b region. Our calculations reproduce all the main features observed in the transient absorption spectra and provide independent insight on the excited-state dynamics of CP29. The approach presented here lays the groundwork for the accurate simulation of EET and unbiased interpretation of transient spectra in multichromophoric systems.
On the bubble trapped underneath a droplet impacting a moving hydrophilic surface: From perfect slip to no slip
Authors: Cheng Jiahao , Hao Jiguang , Li Yalei , Floryan J. M.
Published: November 2023

Much experimental evidence supports the commonly held assertion that fluid does not slip along a solid surface. Here, we demonstrate circumstances in which slip occurs. This happens when the fluid velocity relative to the surface is sufficiently large for the acceleration required to prevent the slip cannot be achieved. To demonstrate the slip, we examine the evolution of a bubble trapped underneath a droplet impacting a moving surface and estimate the parameters determining when the slip occurs. We demonstrate that the terminal slip distance, the maximum distance between where the bubble velocity reaches the surface velocity and the impact point, increases with the surface velocity and weakly depends on the Weber number. Its observed length was up to 1.39 mm. An acceleration extracted from the experiments quantifies the slip and provides a simple tool for predicting the terminal slip distance.
Multilayer BOPET dielectric film with internal double electron barrier for high temperature applications
Authors: Zheng Ming-Sheng , Wang Xinmo , Wan Baoquan , Xiao Mengyu , Cheng Meng , Zhang Yiyi , Zha Jun-Wei
Published: November 2023

With the continuous development of modern electronic and power equipment, practical applications in harsher environment call for film capacitors with higher temperature resistance. Here, we designed a multilayer film including two outer layers of biaxially oriented polyethylene terephthalate (BOPET), two inorganic layers of boron nitride nanosheets (BNNSs), and an intermediate epoxy layer. Due to the blocking effect of the BNNSs layer, the propagation of the breakdown path is hindered, which improves the breakdown strength of the film. Meanwhile, the carrier transport in the medium is effectively hindered, reducing the conduction loss of the composite film. As a result, the optimized multilayer composite film had a high discharged energy density of 8.76 J/cm3, maintaining a high charge-discharge efficiency of 95% at 25 °C, while remarkable values of 7.04 J/cm3 and 73% were obtained even at 150 °C, which showed prominent improvements compared with BOPET. Thus, it turns out to be a promising strategy of fabricating high temperature dielectric films.
Huge Peltier conductivity in valence fluctuating material Yb3Si5
Authors: Kuga Kentaro , Hirata Keisuke , Matsunami Masaharu , Takeuchi Tsunehiro
Published: November 2023

We report the low temperature thermoelectric properties in the valence fluctuating system Yb3Si5 using high-quality single crystals. The coexistence of the tiny residual resistivity of 0.06 μΩ cm and the considerable Seebeck coefficient of 9 μV K−1 at 7 K leads to a huge Peltier conductivity of 40 A cm−1 K−1 and a power factor of 40 mW m−1 K−2. These pronounced characteristics are possibly attributed to the uncompensated semimetallic state in addition to the valence fluctuation of Yb ions. The large size of Yb3Si5 single crystal, which is typically ϕ 0.5–1 mm in diameter and 10 mm in length, enables the realistic application to the cryogenic thermoelectric device.
Exciton–polaron interactions in metal halide perovskite nanocrystals revealed via two-dimensional electronic spectroscopy
Authors: Brosseau Patrick , Ghosh Arnab , Seiler Helene , Strandell Dallas , Kambhampati Patanjali
Published: November 2023

Metal halide perovskite nanocrystals have been under intense investigation for their promise in optoelectronic devices due to their remarkable physics, such as liquid/solid duality. This liquid/solid duality may give rise to their defect tolerance and other such useful properties. This duality means that the electronic states are fluctuating in time, on a distribution of timescales from femtoseconds to picoseconds. Hence, these lattice induced energy fluctuations that are connected to polaron formation are also connected to exciton formation and dynamics. We observe these correlations and dynamics in metal halide perovskite nanocrystals of CsPbI3 and CsPbBr3 using two-dimensional electronic (2DE) spectroscopy, with its unique ability to resolve dynamics in heterogeneously broadened systems. The 2DE spectra immediately reveal a previously unobserved excitonic splitting in these 15 nm NCs that may have a coarse excitonic structure. 2D lineshape dynamics reveal a glassy response on the 300 fs timescale due to polaron formation. The lighter Br system shows larger amplitude and faster timescale fluctuations that give rise to dynamic line broadening. The 2DE signals enable 1D transient absorption analysis of exciton cooling dynamics. Exciton cooling within this doublet is shown to take place on a slower timescale than within the excitonic continuum. The energy dissipation rates are the same for the I and Br systems for incoherent exciton cooling but are very different for the coherent dynamics that give rise to line broadening. Exciton cooling is shown to take place on the same timescale as polaron formation, revealing both as coupled many-body excitation.
Time-dependent flexural gravity wave scattering due to uneven bottom in the paradigm of blocking dynamics
Authors: Boral S. , Meylan Michael H. , Sahoo T. , Ni B.-Y.
Published: November 2023

The present study investigates the scattering of flexural gravity waves due to uneven bottom topography in the context of wave blocking. Emphasis is given to analyzing the effects of multiple propagating wave modes on the solution procedures. The mathematical model is developed for two scenarios: a bottom step and a submerged rectangular breakwater. For the bottom step case, the complete solution in terms of the velocity potential is obtained using the eigenfunction expansion method. Subsequently, the solution associated with the wave transformation by the bottom step is extended to the case of a submerged rectangular breakwater using symmetry characteristics of the velocity potential. The energy balance relation is derived in both cases using the conservation of energy flux in the presence of multiple propagating wave modes. Wave blocking occurs for four different frequencies in both the cases of the bottom step and the submerged breakwater due to variations in water depth. This makes the problem more complex as, depending on the frequency, multiple propagating wave modes can exist in either the reflected region, the transmitted region, or both. The transmitted wave amplitude associated with the lower wavenumber within the blocking frequencies exceeds unity, and this excess energy is balanced by the corresponding energy transfer rate. Additionally, removable discontinuities are observed at the blocking frequencies in the scattering coefficients, where group velocity ceases. In the context of floating ice sheets, the deflection is analyzed in the time domain for frequencies within and outside the blocking limits.
Joint measurement of electron density, temperature, and emission spectrum of Nd:YAG laser-produced tin plasma
Authors: Pan Y. , Tomita K. , Sunahara A. , Sasaki A. , Nishihara K.
Published: November 2023

We present the results of joint measurements of electron density (ne), temperature (Te), and emission spectra of an Nd:YAG-driven tin plasma. Collective Thomson scattering provides space- and time-resolved ne and Te data during drive laser irradiation, and extreme ultraviolet (EUV) emission spectra, which is space-resolved in the target normal, are measured using a flat-field grazing incidence spectrometer (GIS). As the distance from the target increased, the emission intensity quickly decreases, and the peaks of the spectra gradually shift to longer wavelengths. This can be explained by the rapid decrease in ne, and thus, self-absorption, with an increase in distance. We obtain the EUV spectra by calculating the transfer of photons along the line-of-sight of the GIS, using theoretical emissivity and opacity, and applying the measured spatial distribution of ne and Te. The results quantitatively demonstrate that the self-absorption effect is significant; the emission from the core regions is mostly reabsorbed by the surrounding plasma. The calculated spectra are compared with the measured spectra. While good agreement is achieved in the spectral region of 13.3 and 15.3 nm, considerable differences are found in the 12.5–13  and 15.5–17.5 nm region. The results demonstrate the significance of this joint measurement for further validation of the atomic process model considering self-absorption effect, which is critical for the future high-density, solid laser-driven EUV source.
Plexcitonic system for high photonic spin Hall effect
Authors: Sahu Subrat , Srivastava Triranjita , Jha Rajan
Published: November 2023

The photonic spin Hall effect (PSHE) has been intensively studied and widely applied, especially in spin photonics. In this paper, we present the analysis of PSHE in the Plexcitonic system. The signature of the Plexciton is studied by implanting an organic semiconductor layer over the plasmon active metal. We report a high spin-dependent transverse shift of ∼ 60 μm, which is ∼200-fold larger than that of the pure Plasmonic counterpart. The underlying mechanism of PSHE is explained in the circular-polarization basis using the concept of superposition of abnormal and normal modes. It is observed that the transverse shift is highly sensitive to the alterations in the environmental refractive indices leading to its application as a highly sensitive PSHE-based refractometer, with a high sensitivity of 81°/RIU. We believe these results may open pathways for modulating the PSHE and developing nanophotonic applications such as advanced sensors and next-generation optical devices.
The polarization-modulated electronic structure and giant tunneling-electroresistance effect of a one-dimensional ferroelectric Ta4OTe9I4 nanowire
Authors: Zhang Fumin , Kang Lili , Liu Chang , Wang Bing , Yin Huabing
Published: November 2023

Low-dimensional ferroelectrics have a great deal of potential for use in electronic memory devices. However, intrinsic one-dimensional (1D) ferroelectricity is very rare. Using first-principles calculations, we present the discovery of an inborn 1D Ta4OTe9I4 ferroelectric (FE) nanowire. Its distinctive geometry can cause spontaneous electric polarization along the z-axis and allow it to maintain a certain temperature and strain. In addition to its sizable spontaneous polarization and appropriate Curie temperature, the 1D Ta4OTe9I4 nanowire exhibits an energy barrier comparable to those of other ferroelectrics. With polarization reversal, the energy gap can be modulated in the range of 0.38–1.33 eV, corresponding to an apparent peak shift phenomenon in the optical response. We use this nanowire as an exemplary material for building a FE tunnel junction composed of Hf0.5Ta3.5OTe9I4/Ta4OTe9I4/W0.5Ta3.5OTe9I4 with a giant tunneling electroresistance ratio at zero and low bias. Our calculations suggest that this 1D intrinsically FE material obtained from van der Waals crystals can be used in miniaturized and advanced high-density information storage.
Measurements of absolute line strength of the ν1 fundamental transitions of OH radical and rate coefficient of the reaction OH + H2O2 with mid-infrared two-color time-resolved dual-comb spectroscopy
Authors: Chang Che-Wei , Chen I-Yun , Fittschen Christa , Luo Pei-Ling
Published: November 2023

Absolute line strengths of several transitions in the ν1 fundamental band of the hydroxyl radical (OH) have been measured by simultaneous determination of hydrogen peroxide (H2O2) and OH upon laser photolysis of H2O2. Based on the well-known quantum yield for the generation of OH radicals in the 248-nm photolysis of H2O2, the line strength of the OH radicals can be accurately derived by adopting the line strength of the well-characterized transitions of H2O2 and analyzing the difference absorbance time traces of H2O2 and OH obtained upon laser photolysis. Employing a synchronized two-color dual-comb spectrometer, we measured high-resolution time-resolved absorption spectra of H2O2 near 7.9 µm and the OH radical near 2.9 µm, simultaneously, under varied conditions. In addition to the studies of the line strengths of the selected H2O2 and OH transitions, the kinetics of the reaction between OH and H2O2 were investigated. A pressure-independent rate coefficient kOH+H2O2 was determined to be [1.97 (+0.10/−0.15)] × 10−12 cm3 molecule−1 s−1 at 296 K and compared with other experimental results. By carefully analyzing both high-resolution spectra and temporal absorbance profiles of H2O2 and OH, the uncertainty of the obtained OH line strengths can be achieved down to <10% in this work. Moreover, the proposed two-color time-resolved dual-comb spectroscopy provides a new approach for directly determining the line strengths of transient free radicals and holds promise for investigations on their self-reaction kinetics as well as radical–radical reactions.
Giant irreversibility of the inverse magnetocaloric effect in the Ni47Mn40Sn12.5Cu0.5 Heusler alloy
Authors: Kamantsev A. P. , Koshkidko Yu. S. , Bykov E. O. , Gottschall T. , Gamzatov A. G. , Aliev A. M. , Varzaneh A. G. , Kameli P.
Published: November 2023

Direct studies of the adiabatic temperature change (ΔTad) in the Ni47Mn40Sn12.5Cu0.5 Heusler alloy in steady magnetic fields up to 8 T by the extraction method and in pulsed magnetic fields up to 50 T were carried out in this paper. The alloy Ni47Mn40Sn12.5Cu0.5 demonstrates a magnetostructural phase transition (MSPT) of the first order in the 254–283 K temperature range as well as a second order phase transition near the Curie temperature TC = 313 K. An inverse magnetocaloric effect (MCE) was found in the region of the MSPT, and it reaches the maximum value ΔTad = −12 K in 20 T at the initial temperature T0 = 275 K. The irreversible part of the MCE reached ΔTir = −10 K when the field is completely removed. We consider the dynamics of the MCE in the vicinity of the MSPT and discuss the mechanisms that cause the giant irreversibility of the MCE as well as the possibilities of its application in hybrid cooling systems.
Laser-induced Bragg resonances in ferrit/semiconductor heterostructure
Authors: Morozova M. A. , Matveev O. V. , Gusev S. A. , Gusev N. S. , Romanenko D. V. , Nikitov S. A.
Published: November 2023

The paper reports on laser-induced Bragg resonances in the spectrum of magnetostatic waves in a heterostructure based on a ferrite film [yttrium iron garnet (YIG)] with periodic strips of semiconductor material (Si) on the surface. Laser irradiation of such a structure leads to the formation of Bragg bandgaps due to the modulation of the Si conductivity on the YIG surface, and the magnitude modulation increases with increasing laser radiation intensity. It is shown that an increase in laser radiation intensity also leads to an increase in the depth and frequency shift of the bandgaps.
Uniform multilevel switching and synaptic properties in RF-sputtered InGaZnO-based memristor treated with oxygen plasma
Authors: Mahata Chandreswar , So Hyojin , Yang Seyeong , Ismail Muhammad , Kim Sungjun , Cho Seongjae
Published: November 2023

Bipolar gradual resistive switching was investigated in ITO/InGaZnO/ITO resistive switching devices. Controlled intrinsic oxygen vacancy formation inside the switching layer enabled the establishment of a stable multilevel memory state, allowing for RESET voltage control and non-degradable data endurance. The ITO/InGaZnO interface governs the migration of oxygen ions and redox reactions within the switching layer. Voltage–stress-induced electron trapping and oxygen vacancy formation were observed before conductive filament electroforming. This device mimicked biological synapses, demonstrating short- and long-term potentiation and depression through electrical pulse sequences. Modulation of post-synaptic currents and pulse frequency-dependent short-term potentiation were successfully emulated in the InGaZnO-based artificial synapse. The ITO/InGaZnO/ITO memristor exhibited spike–amplitude-dependent plasticity, spike–rate-dependent plasticity, and potentiation–depression synaptic learning with low energy consumption, making it a promising candidate for large-scale integration.
A flux growth technique for high quality cubic boron arsenide bulk single crystals
Authors: Koirala Pawan , Liu Wenhao , Wu Hanlin , Kondusamy Aswin L. N. , Dhale Nikhil , Glaser Evan R. , White Sam , Culbertson J. C. , Freitas J. A. , Lv Bing
Published: November 2023

The growth of single crystal cubic boron arsenide (c-BAs) has attracted considerable interest due to its high room-temperature thermal conductivity and high ambipolar electrical mobility. However, currently the only growth technique reported for c-BAs crystals is the chemical vapor transport (CVT) method, which exhibits several drawbacks with regard to size scalability and crystal quality control, thereby hindering the further advancement of this semiconductor material. Herein, we report a flux growth technique using liquid arsenic (l-As) as a reaction medium at high pressures for the growth of high-quality c-BAs crystals with several millimeters size. The outstanding properties, including high uniformity, lower defect density, and lower carrier concentration of the as-grown c-BAs single crystals from flux growth, have been verified via a combination of techniques including x-ray diffraction, Raman scattering, photoluminescence spectroscopy, and electrical transport measurements, in comparison with the CVT-grown crystals.
The emergence and diversification of a zoonotic pathogen from within the microbiota of intensively farmed pigs
Authors: Murray Gemma G. R. , Hossain A. S. Md. Mukarram , Miller Eric L. , Bruchmann Sebastian , Balmer Andrew J. , Matuszewska Marta , Herbert Josephine , Hadjirin Nazreen F. , Mugabi Robert , Li Ganwu , Ferrando Maria Laura , Fernandes de Oliveira Isabela Maria , Nguyen Thanh , Yen Phung L. K. , Phuc Ho D. , Zaw Moe Aung , Su Wai Thiri , Gottschalk Marcelo , Aragon Virginia , Valentin-Weigand Peter , Heegaard Peter M. H. , Vrieling Manouk , Thein Maw Min , Thidar Myint Hnin , Tun Win Ye , Thi Hoa Ngo , Bentley Stephen D. , Clavijo Maria J. , Wells Jerry M. , Tucker Alexander W. , Weinert Lucy A.
Published: November 2023

The expansion and intensification of livestock production is predicted to promote the emergence of pathogens. As pathogens sometimes jump between species, this can affect the health of humans as well as livestock. Here, we investigate how livestock microbiota can act as a source of these emerging pathogens through analysis of
Streptococcus suis
, a ubiquitous component of the respiratory microbiota of pigs that is also a major cause of disease on pig farms and an important zoonotic pathogen. Combining molecular dating, phylogeography, and comparative genomic analyses of a large collection of isolates, we find that several pathogenic lineages of
S. suis
emerged in the 19th and 20th centuries, during an early period of growth in pig farming. These lineages have since spread between countries and continents, mirroring trade in live pigs. They are distinguished by the presence of three genomic islands with putative roles in metabolism and cell adhesion, and an ongoing reduction in genome size, which may reflect their recent shift to a more pathogenic ecology. Reconstructions of the evolutionary histories of these islands reveal constraints on pathogen emergence that could inform control strategies, with pathogenic lineages consistently emerging from one subpopulation of
S. suis
and acquiring genes through horizontal transfer from other pathogenic lineages. These results shed light on the capacity of the microbiota to rapidly evolve to exploit changes in their host population and suggest that the impact of changes in farming on the pathogenicity and zoonotic potential of
S. suis
is yet to be fully realized.
Abstract cognitive maps of social network structure aid adaptive inference
Authors: Son Jae-Young , Bhandari Apoorva , FeldmanHall Oriel
Published: November 2023

Social navigation—such as anticipating where gossip may spread, or identifying which acquaintances can help land a job—relies on knowing how people are connected within their larger social communities. Problematically, for most social networks, the space of possible relationships is too vast to observe and memorize. Indeed, people's knowledge of these social relations is well known to be biased and error-prone. Here, we reveal that these biased representations reflect a fundamental computation that abstracts over individual relationships to enable principled inferences about unseen relationships. We propose a theory of network representation that explains how people learn inferential cognitive maps of social relations from direct observation, what kinds of knowledge structures emerge as a consequence, and why it can be beneficial to encode systematic biases into social cognitive maps. Leveraging simulations, laboratory experiments, and “field data” from a real-world network, we find that people abstract observations of direct relations (e.g., friends) into inferences of multistep relations (e.g., friends-of-friends). This multistep abstraction mechanism enables people to discover and represent complex social network structure, affording adaptive inferences across a variety of contexts, including friendship, trust, and advice-giving. Moreover, this multistep abstraction mechanism unifies a variety of otherwise puzzling empirical observations about social behavior. Our proposal generalizes the theory of cognitive maps to the fundamental computational problem of social inference, presenting a powerful framework for understanding the workings of a predictive mind operating within a complex social world.
Weakest link or strongest link?
Authors: Donovan Andrea Marquardt , Brown Sarah A. , Alibali Martha W.
Published: November 2023

Teachers often use gestures to connect representations of mathematical ideas. This research examined (1) whether
such linking gestures help students understand connections among representations and (2) whether sets of gestures that include
repeated handshapes and motions – termed gestural catchments – are particularly beneficial. Undergraduates viewed
one of four video lessons connecting two representations of multiplication. In the control lesson, the instructor
produced beat gestures that did not link the representations. In the link-only lesson, the instructor used
gestures to link representations, but the gestures did not form a catchment. In the consistent-catchment lesson,
the instructor highlighted corresponding elements of the two representations using identical gestures. In the
inconsistent-catchment lesson, the instructor highlighted non-corresponding elements of the two
representations using identical gestures. Participants who saw the lesson with the consistent catchment – which highlighted
similarities between representations – were most likely to understand the novel representation and to report learning from the
lesson.
Parody against hate speech
Authors: Trigoso Marco
Published: November 2023

Political crises often lead to the violent use of digital platforms. This text aims to analyze a particular
response to that vitriolic discourse on Twitter: political parody. During the institutional crisis and political battle between
the government of former Peruvian President Martín Vizcarra and the Peruvian Congress between 2017 and 2019, some political actors
stood out, but not for good reasons. Karina Beteta, a right-wing Peruvian parliamentarian, used Twitter to interact with people,
defend her decisions and attack anyone who did not share her viewpoints. She distinguished herself by tweeting confusing and,
according to some, mocking texts. These tweets received an original counter-discourse with the creation of @smartbeteta, a parody
account of politics. This paper analyzes the parodic performance by focusing on the pragmatic strategies embedded in
@smartbeteta’s tweets and the role adopted by this account in the communication flows.
Supra- and sub-gingival instrumentation of periodontitis with the adjunctive treatment of a chloramine – a one-year randomized clinical trial study
Authors: Wallin-Bengtsson Viveca , Scherdin-Almhöjd Ulrica , Roos-Jansåker Ann-Marie
Published: November 2023

Periodontitis is a bacterial-induced disease and for this reason controlling the microbiota is a necessity. Therapy includes self-performed daily oral hygiene in combination with supra- and sub-gingival instrumentation. An adjunctive antimicrobial agent may improve the outcome.
Aims: To assess whether a chloramine (Perisolv®) has an adjunctive effect to non-surgical periodontal therapy and whether non-surgical periodontal therapy affects quality of life.
Material and Methods: Thirty-eight patients were randomized to a test or a control group. Clinical indices were performed at baseline and at three and twelve months. In the test group, Perisolv® was applied initially and after the sub-gingival instrumentation in pathological pockets. Oral health-related quality of life was measured with the Oral Health Impact Profile (OHIP) instrument at baseline and twelve months.
Results: In both groups, an initial probing pocket depth (PPD) of > 4 mm and bleeding on probing (BOP) were statistically reduced (p < 0.002 and p < 0.002 respectively) at twelve months and after adjustment for Bonferroni. There were no significant differences between the test and the control group in terms of the number of PPD, BOP or plaque index, or in the mean OHIP score.
Conclusions: Chloramine did not have an adjunctive effect, but the overall therapy was significantly efficacious both clinically and in terms of quality of life.
Trial registration: Registered at www.clinicaltrials.gov:NCT05757921.
An exact, coordinate independent classical firewall transformation
Authors: Strauss Nathaniel A , Whiting Bernard F
Published: November 2023

A proposal for resolving the black hole information paradox was recently put forward by ’t Hooft in the form of his firewall transformation. Although this proposal has begun to gain some limited traction, its physical foundation is still somewhat obscure. Here we develop a classical Hamiltonian analog, which is oriented towards quantization, by using the canonical formalism developed by Arnowitt, Deser, and Misner (ADM). We use a model of two null, spherical shells in a Schwarzschild black hole background, and within our ADM formalism we are able to characterize the dynamics of the entire system, especially at the point of collision, and we reproduce the related Dray–’t Hooft–Redmount formula. Finally, we are able to find a classical analog for ’t Hooft’s firewall transformation. Unlike ’t Hooft’s firewall transformation and previous classical analogs, the classical firewall transformation we obtain is free from approximation and maintains the coordinate independence of the ADM formalism. We leave to future work the quantization of the theory.
A geomagnetic vector evolutionary compensation method using Woodbury equation
Authors: Zhang Qi , Liu Zhongyan , Xu Yujing , Guan Feng , Huang Bo , Pan Mengchun , Hu Jiafei , Chen Zhuo , Qiu Xiaotian , Tang Ying
Published: November 2023

High-accuracy geomagnetic vector measurements inevitably suffer from the magnetic interference derived from ferromagnetic materials and electric equipment. Traditionally, to eliminate the influence of magnetic interference, a compensation process can be implemented to estimate the interference parameters that contain hard-iron and soft-iron parameters. The traditional compensation method did not consider the situation where the interference parameters would vary over time due to the change in magnetic properties. To overcome this problem, we proposed an evolutionary compensation method based on the Woodbury equation. Using this approach, the interference parameters can be iteratively updated during the measurement process by combining the previous information and the latest measurement data. Both simulation and experimentation were undertaken to evaluate the effectiveness of our proposed approach. The results demonstrate that the proposed method is successful in minimizing the impact of magnetic interference variations. The experiment shows that the RMS errors of geomagnetic filed total intensity and three components can be decreased from 4042.57 nT, 1425.84 nT, 5342.40 nT, and 2921.34 nT to 170.57 nT, 58.39 nT, 207.99 nT and 137.75 nT respectively by traditional method, while with evolutionary method the errors can be reduced to 47.37 nT, 16.19 nT, 57.61 nT and 38.38 nT respectively.
Activated vortex lattice transition in a superconductor with combined sixfold and twelvefold anisotropic interactions
Authors: Minogue D , Eskildsen M R , Reichhardt C , Reichhardt C J O
Published: November 2023

Numerical simulations are used to examine the transition dynamics between metastable and ground state vortex lattice phases in a system with combined sixfold and twelvefold contributions to the vortex–vortex interactions. The system is initially annealed using a twelvefold anisotropy, yielding domains of two different orientations and separated by grain boundaries. The vortex–vortex interaction is then suddenly changed to a sixfold anisotropy, rendering the twelvefold state metastable. Applying a drive that mimics an oscillating magnetic field causes the metastable state to decay, indicated by the structure factor that evolves from twelve to six peaks. The results fit the behavior seen in recent small-angle neutron scattering studies of the vortex lattice in MgB2. At higher drive amplitudes, the decay exhibits a two step process in which the initial fast decrease is followed by a slower regime where avalanches or bursts are correlated with dislocation annihilation events. The results are compared to other types of metastable systems with quenched disorder that decay under a periodic external drive.
Nonlinear polarization holography of nanoscale iridium films
Authors: Hazra Mouli , Paul Pallabi , Kim Doyeong , David Christin , Gräfe Stefanie , Peschel Ulf , Kübel Matthias , Szeghalmi Adriana , Pfeiffer Adrian N
Published: November 2023

Attosecond nonlinear polarization spectroscopy designates the subcycle-precise retrieval of the electric field of a femtosecond laser pulse together with the nonlinear polarization response that the laser pulse triggers in a sample. Here, we introduce a method that is all-optical and applicable to metal films. The method is called nonlinear polarization holography because it is based on the comparison of two time-domain holograms with and without a metal film on a substrate. The working principle can be understood as the time-domain analog of holographic interferometry, in which the comparison of two spatial holograms reveals changes in an object’s size and position with interferometric precision (i.e. to fractions of the wavelength). Analogously, nonlinear polarization holography provides subcycle precision (i.e. to fractions of the optical period). Nonlinear polarization holography is used here to retrieve the time-domain nonlinear response of a nanoscale iridium film. Using density matrix calculations it is shown that the knowledge of the nonlinear response with subcycle precision allows distinguishing excitation and relaxation mechanisms of low-energetic electrons.
Generation of ultrashort Rayleigh wave pulses using the combination of temporal and spatial pulse compression technique
Authors: Jiang Chuanliu , Li Zhichao , Wang Shujuan
Published: November 2023

Rayleigh waves generated by electromagnetic acoustic transducers (EMATs) have been widely used in nondestructive testing and evaluations. To improve the signal to noise ratio (SNR) and spatial resolution of Rayleigh waves simultaneously, the combination of temporal and spatial pulse compression (TSPC) technique is proposed. By analyzing the topology diagram of the typical pulse compression technique, a frequency modulated signal acts as the stretcher and a wavelength modulated meander line coil acts as the compressor. Experimental results indicate that the ultrasound fields of Rayleigh waves using the proposed TSPC technique show a spike shape in the spatial domain. Compared with the typical meander-line coil EMATs, the TSPC technique shows significant improvement of the generated Rayleigh waves. The SNR has increased by 12 dB while the main lobe width has decreased by about 98%.