bluuebunny/crossref_metadata_2025 huggingface dataset:
Absolute calibration methodology for non-uniform uranium and matrix distributions in large barrels of uranium-bearing solid waste
Authors: El-Kourghly K. M.
Published: December 2024

The effective implementation of domestic and international safeguards necessitates verification techniques for Nuclear Materials (NM). Even in the case of very small quantities of NMs, accounting for and analyzing such traces can provide insights into the mass balance of NMs and/or state activities, ensuring consistency in state declarations. This paper proposes and benchmarks an absolute calibration methodology for estimating the uranium–mass content in large-volume barrels (200 L). These barrels may be generated during the operation and decommissioning of bulk handling facilities by accumulating low-density scarab contaminated with NMs. The method relies on the mathematical calibration of a High Purity Germanium (HPGe) detector efficiency against non-uniform uranium and matrix distributions, assuming that the non–uniform distribution can be approximated as a uniform one for low–density matrix materials. The peak efficiency is calculated for different numbers of point sources 1–30 likely distributed inside a simulated barrel while it rotates around the axis of symmetry. The proposed method is benchmarked by comparing the calculated peak efficiency of randomly distributed uranium sources with the homogeneous distribution. Furthermore, a comparison with experimental measurements is conducted to validate the proposed method. Results show that the proposed calibration method considering either random or homogeneous source and matrix distributions in large volume barrels can be used for estimating the uranium mass content in NSW with an accuracy of approximately 12 %.
Clustering- and statistic-based approach for detection and impact evaluation of faults in end-user substations of thermal energy systems
Authors: Weber Samanta A. , Fischlschweiger Michael , Volta Dirk , Rieck-Blankenburg Ulf
Published: December 2024

In response to climate change mitigation efforts, improving the efficiency of heat networks is becoming increasingly important. An efficient operation of energy systems depends on faultless performance. Following the need for effective fault detection and elimination methods, this study suggests a three-step workflow for increasing automation in managing defective substations on the user level within heat networks. The work focuses on a model region in northern Germany. The local heat network provides data in roughly hourly intervals, including the supply and return temperatures and the volume flow of the substations. Firstly, this study identifies common indicators of faults using k-means clustering analysis of the temperature data and expert knowledge: an exceeded return temperature level, very low cooling, and inverted temperature readings. With these indicators, the subsequent statistical identification approach confirms the successful detection of affected substations, with common diagnoses including disabled return temperature limitation units, defective motoric valves, and faults in the storage control. Lastly, the study evaluates the impact of faults on the system efficiency. Combining the temperature and the volume flow data, the workflow quantifies the negative influence of a fault, enabling the prioritization of fault elimination measures in practical application to enhance the overall system efficiency.
Automated differentiation of wide QRS complex tachycardia using QRS complex polarity
Authors: May Adam M. , Katbamna Bhavesh B. , Shaikh Preet A. , LoCoco Sarah , Deych Elena , Zhou Ruiwen , Liu Lei , Mikhova Krasimira M. , Ghadban Rugheed , Cuculich Phillip S. , Cooper Daniel H. , Maddox Thomas M. , Noseworthy Peter A. , Kashou Anthony
Published: December 2024

Background

Wide QRS complex tachycardia (WCT) differentiation into ventricular tachycardia (VT) and supraventricular wide complex tachycardia (SWCT) remains challenging despite numerous 12-lead electrocardiogram (ECG) criteria and algorithms. Automated solutions leveraging computerized ECG interpretation (CEI) measurements and engineered features offer practical ways to improve diagnostic accuracy. We propose automated algorithms based on (i) WCT QRS polarity direction (WCT Polarity Code [WCT-PC]) and (ii) QRS polarity shifts between WCT and baseline ECGs (QRS Polarity Shift [QRS-PS]).

Methods

In a three-part study, we derive and validate machine learning (ML) models—logistic regression (LR), artificial neural network (ANN), Random Forests (RF), support vector machine (SVM), and ensemble learning (EL)—using engineered (WCT-PC and QRS-PS) and previously established WCT differentiation features. Part 1 uses WCT ECG measurements alone, Part 2 pairs WCT and baseline ECG features, and Part 3 combines all features used in Parts 1 and 2

Results

Among 235 WCT patients (158 SWCT, 77 VT), 103 had gold standard diagnoses. Part 1 models achieved AUCs of 0.86–0.88 using WCT ECG features alone. Part 2 improved accuracy with paired ECGs (AUCs 0.90–0.93). Part 3 showed variable results (AUC 0.72–0.93), with RF and SVM performing best.

Conclusions

Incorporating engineered parameters related to QRS polarity direction and shifts can yield effective WCT differentiation, presenting a promising approach for automated CEI algorithms.
Recent advances in visible light-driven phosphine-mediated transformations
Authors: Feng Jiaxu , Nicchio Luca , Liu Liting , Wu Yingying , Lu Kui , Protti Stefano , Zhao Xia
Published: December 2024

The review presents a survey of the latest advancements in light- and phosphine-mediated C–C and C-heteroatom bond formation.
Exciton kinetics in xenon–krypton cryocrystals
Authors: Fugol’ I. Ya. , Belov A. G. , Yurtaeva E. M. , Svishchev V. N.
Published: December 2024

On the basis of experimental studies of the luminescence of Xe–Kr solid solutions under electronic excitation as well as on the basis of an analysis of the results within the framework of the model of diffusion motion in Xe–Kr solid solutions, we examine the mechanisms of the migration and relaxation of electronic excitations of the matrix and also study the processes of energy transfer to the impurity states of K and Xe2. It is shown that in pure Kr crystals and low-concentration solutions (c < 0.1 mole % Xe) the migration of excitations is due mainly to the diffusion of free excitons. The presence of a homological Xe impurity sharply increases the scattering of coherent excitations, which leads to self-trapping of the excitations. For c > 0.3% Xe as a result of this process energy transfer is affected primarily by self-trapped excitons. The agreement between the model diffusion calculations with the experimental data enabled us to determine the principal kinetic parameters of the motion of self-trapped excitons, viz., the diffusion coefficient, the average velocity, and the diffusion length of the exciton displacement.
Decrease in the background in electron–phonon interaction spectra for point contacts with a superconducting electrode
Authors: Kamarchuk G. V. , Khotkevich A. V. , Yanson I. K.
Published: December 2024

A substantial decrease is observed in the level of the background in point contact electron–phonon interaction spectra for contacts between different metals at the transition of one of the metals into the superconducting state. The magnitude of the effect is maximum for pure contacts, characterized by the highest excess currents in the case when one of the electrodes in the contact is in the superconducting state.
Positive curvature of the temperature dependence of the upper critical field in superconducting superlattices
Authors: Gvozdikov V. M.
Published: December 2024

The positive curvature of the temperature dependence of the upper critical field, parallel to the layers in superconductors with a small anisotropy (of the order of several units), is shown to be a consequence of the difference in the orbital effect when the magnetic field has a parallel or perpendicular orientation. This conclusion is based on the results of experimental data processing for artificially produced superconducting structures of the superconductor–normal metal type with the aid of a formula derived in this paper that implicitly gives the relation between the values of the upper critical field for parallel and perpendicular field orientations.
Range of existence of the low-temperature phases in cold-deposited sodium films
Authors: Kupreĩchenko V. S. , Moshenskiĩ A. A. , Spasova M. A.
Published: December 2024

The temperature dependences of the electrical resistivity of thin (d = 100−1000 Å) cold-deposited sodium films have been investigated. Anomalies were found in the R(T) relation for films of thickness d < 750 Å in the temperature range up to 100 °K. Comparison of the anomalies in R(T) with results of structural investigations enabled a qualitative model to be constructed of the structural transformation processes which take place on annealing cold-deposited Na films.
Electron localization in antimony films in a parallel magnetic field
Authors: Butenko A. V. , Bukhshtab E. I.
Published: December 2024

The dependence of the localized correction to the magnetoconductivity in thin antimony films is studied. The behavior of this correction in a magnetic field parallel to the plane of the film is compared with the theory that takes into account the diffuse scattering of electrons by the surface of the films in which the volume mean-free path exceeds the thickness.
Clusters of exchange-coupled oxygen molecules in solidified-gas matrices
Authors: Ostrovskiĭ V. S. , Sumarokov V. V. , Freĭman Yu. A.
Published: December 2024

The energy spectrum of an exchange-coupled pair of oxygen molecules with arbitrary orientation of the axes of the molecules as well as the contribution of paired clusters to the thermodynamics of solid solutions of solidified gases with oxygen are calculated. It is shown that the study of the anomalies of the thermodynamic properties of these solutions can be used to study the exchange interaction of O2 molecules.
Current-induced instability of the superconducting state in metallic glasses
Authors: Yartsev S. V. , Prekul A. F.
Published: December 2024

A new type of instability has been found in superconductors with a heterogeneity induced by electron autolocalization. The critical parameters of the superconductor are subject to slow relaxation below the transition temperature.
Nonequilibrium states of superconductors with narrowband ultrasonic pumping
Authors: Kashurnikov V. A.
Published: December 2024

The action of monochromatic phonon pumping on a superconductor is investigated at threshold frequencies Ω ∼ 2Δ sufficient for the generation of excess quasiparticles. A multiple-valued function Δ = Δ (Ω) is obtained.
Temperature-electric domain instability in metals generated by boiling of a cryogenic liquid
Authors: Boiko V. V. , Podrezov Yu. F. , Klimova N. P.
Published: December 2024

The current–voltage characteristics (IVC) of metals (Pt, Cu, W, Mg) and alloys (tungsten–rhenium, constantan, etc.), cooled directly by liquid nitrogen and liquid helium, are studied experimentally. The properties of the temperature-electric domains (TED), appearing in metals, are determined. It is established that boiling of the coolant causes the IVC of metallic conductors to assume an N−S-shaped form. The parameters determining the possibility of a spontaneous transition of the sample into a stable state with TED are calculated with a piecewise-linear approximation for the temperature dependences of the heat exchange between the sample and the liquid and of the resistivity of the sample.
Theory of magnetic susceptibility of bismuth and its alloys with antimony
Authors: Mikitik G. P.
Published: December 2024

The magnetic susceptibility of bismuth and its alloys with antimony in weak magnetic fields is calculated on the basis of a model which describes the energy spectrum with an accuracy falling between the McClure and McClure–Choi (or Dorofeev–Fal’kovskiĭ) models. The results of the calculations are compared with the available experimental data.
Influence of pressure on the effective electron masses in cadmium
Authors: Budarin A. G. , Ventsel’ V. A. , Rudnev A. V.
Published: December 2024

The effective masses of conduction electrons in cadmium at pressures up to 8 kbar have been measured from the temperature dependence of the amplitudes of oscillations in the de Haas-van Alphen effect. A comparison of the effective masses for the cross section of the Fermi surface of zinc and cadmium, which were determined with the aid of cyclotron resonance and the de Haas-van Alphen effect, has revealed a case when the extremal effective mass differs from the effective mass of the extremal cross section of the Fermi surface.
Configurational relaxation and the thermal conductivity of solid H2 with a small ortho-modification content
Authors: Gorodilov B. Ya. , Krupskiĭ I. N. , Manzheiĭ V. G. , Korolyuk O. A.
Published: December 2024

Results are given of measurements of the thermal conductivity of single-crystal specimens of solid hydrogen with ortho-modification content from 0.21 to 4.4% in the temperature range 1.4–11° K. An effect was found ofclustering of the ortho-molecules on the thermal conductivity. The relaxation time of the ortho-subsystem was determined in the temperature range 1.5–3° K. It follows from the results obtained the thermal resistivity of the crystals, associated with that scattering of phonons by the ortho-subsystem with random distribution of ortho-molecules in the lattice up to 0.21% o–H2, is proportional to x2T−3.
Effect of impurities on the residual resistivity of refractory metals
Authors: Aleksandrov B. N.
Published: December 2024

The values or Δρ0/c (change in the residual resistivity of the metal-matrix accompanying dissolution of 1 at. % impurity) for 8−14 different impurities in each of the seven metals W, Re, Ta, Mo, Ru, Ir, and Rh, are determined from the published experimental data on the dependences of the resistivity ρ for these metals on the concentration c of the dissolved impurity. The change in Δρ0/c as a function of the mutual position of the impurity and the matrix in the periodic table is studied. The values of Δρ0/c are predicted for the impurities Cr, Os, Tc, and Mn in several matrices. It is established that the effect of oxygen on the residual resistivity ρ0 for group V metals is weaker than for group IV metals.
Negative low-temperature magnetoresistance of a magnetically inhomogeneous compensated metal
Authors: Zakharov Yu. V. , Man’kov Yu. I. , Titov L. S.
Published: December 2024

The variation of the low-temperature resistance of a ferromagnet with a plane-parallel domain structure during magnetization is investigated theoretically. When the width of a decreasing domain becomes smaller than the cyclotron diameter of the electron orbit, electron trajectories that encompass the decreasing domain appear when τω ≫ l. This leads to a change in the periodicity of electrons that cross a domain wall or a decreasing domain and as a result the conductivity has a nonmonotonic dependence on the coordinate normal to the wall and increases in comparison to the conductivity in a homogeneously magnetized sample. The dependence of the resistance on the relative magnetization is studied and a negative magnetoresistance (≈20%), of the same order of magnitude as the experimental data of a number of authors, is detected.
Conditions for the formation of a moving bound state of a pair of quasiparticles
Authors: Kuzovlev Yu. E. , Lomtev A. I.
Published: December 2024

The spectra and the necessary criteria for the existence of a bound state of a pair of activation or Goldstone quasiparticles, whose energy depends on the momentum according to a power law with index n ≤ 2, are derived. In a space of dimensions d ≥ 2 a bound state forms with an arbitrarily weak attraction independently of the magnitude of the total momentum of the pair 2Q, while in a space of dimension > 2 the bound state forms only it 2Q is less than a critical value 2Qc. For Q > Qc the bound state is destroyed by a kinetic mechanism.
Mechanisms determining the broadening of resistive transitions of thin superconducting films
Authors: Fogel’ N. Ya. , Cherkasova V. G. , Dmitrenko I. M. , Sidorenko A. S.
Published: December 2024

Resistive transitions in thin superconducting films of simple (In, Sn) and transition (V, Ta) metals in a perpendicular magnetic field are studied. In transition-metal films the relative broadening of the transitions ΔH⊥/Hc⊥ (T) increases with the temperature and varies inversely proportionally to the electron mean-free path length l, while the ratio of the broadening of the transitions in the field H⊥ and at H = 0 as a function of l remains unchanged in accordance with the theory of critical fluctuations in two-dimensional superconductors. The observed smearing of the transitions is quantitatively in agreement with the values of the Ginzburg magnetic number obtained on the basis of the theory Feat and Rickayzen. The resistive behavior of In and Sn differs substantially from that observed in transition-metal films. The relative broadening of the transition is independent of the temperature, and its dependence on l is nonmonotonic. In implanted helium films with a variable electron mean-free path length there is no correlation between the broadening of the transitions in the perpendicular field and at H = 0. The experimental values of the broadening of transitions exceed by several orders of magnitude the computed width of the critical region. In this case the smearing of the phase transitions is caused by nonuniformities of the parameters of the superconductor.
Statistical theory of the hydrogen melting curve
Authors: Ryzhov V. N. , Tareeva E. E. , Shchelkacheva T. I.
Published: December 2024

The crystallization of molecular hydrogen is described as a branching of the solution of a certain nonlinear integral equation for the one-particle distribution function. The melting curves and the volume change in crystallization are determined from the known direct correlation function of the liquid phase with the use of a solid-core model potential.
Experimental observation of enhanced electron currents in the vicinity of a point contact
Authors: Andrievskii V. V. , Ass E. I.
Published: December 2024

Using transverse electron focusing without a magnetic field, we have observed an increase in the density of the electron current in particular directions on a bismuth surface.
Study of the resistive state of film superconductors by the laser-probe method
Authors: Konovodchenko V. A. , Sivakov A. G. , Zhuravel’ A. P. , Efremenko V. G. , Banduryan B. B.
Published: December 2024

The resistive state of two-dimensional superconductors was studied by the method of laser probing. Two-dimensional images of separate phase-slip lines as well as the temperature distribution in the film under conditions of nonuniform heat removal were obtained for superconducting tin films.
Point-contact spectroscopy of superconductors in the nonequilibrium state
Authors: Yanson I. K. , Rybal’chenko L. F. , Bobrov N. L. , Fisun V. V.
Published: December 2024

A phase transition of the region of the superconductor near the point contact into a new nonequilibrium state at the critical density of nonequilibrium quasiparticles is observed.
Characteristic features of nonlinear phenomena in He3-A in a strong magnetic field
Authors: Baramidze G. A.
Published: December 2024

The nonlinear effects in superfluid He3-A in the presence of a strong magnetic field near the phase transition A → A1 are examined. It is shown that a specific spin-temperature discontinuity, whose velocity of propagation, to lowest order, equals the velocity of the longitudinal spin wave, while the nonlinear correction to it is sign-alternating, forms in the A1 phase. The possibility of the appearance of a magnetized soliton on the free surface of a film of liquid He3 is discussed.
Theory of electrical polarization of multisublattice orthorhombic antiferromagnets with a double-exchange superlattice
Authors: Stefanovskiĭ E. P. , Yablonskiĭ D. A.
Published: December 2024

The onset of electric polarization in the modulated phase of some orthorhombic antiferromagnets (space group D2h16−Pbnm) is explained in terms of the magnetoelectric effect. The specific case of Cr2BeO4 is considered. Expressions are derived for the components of the electric polarization vector P in terms of the constants of the corresponding thermodynamic potentials and the absolute values of the antiferromagnetism vectors. The theoretical derivations are compared qualitatively with the experimental data.
Collisionless microwave energy absorption by a breather gas in a one-dimensional magnet
Authors: Gorelik L. Yu. , Kulinich S. I.
Published: December 2024

The collisionless absorption of energy from a microwave field polarized along the ground state of a ferromagnet by a breather gas is studied. It is established that the energy absorbed by the breather subsystem as a function of the external frequency has a sharp peak, lying below the doubled frequency of the homogeneous ferromagnetic resonance.
Field dependences of the magnetic susceptibility of bismuth and its alloys with antimony in weak magnetic fields
Authors: Mikitik G. P.
Published: December 2024

Expressions describing the field dependences of the magnetic susceptibility of bismuth and its alloys with antimony in weak magnetic fields are derived and analyzed. It is shown that these dependences are very sensitive to changes in the electronic band structure of the bismuth alloys.
Optical Dicke superradiation of solid solutions of pyrene in diphenyl under conditions of local heating of the sample
Authors: Andrianov S. N. , Zinov’ev P. V. , Malyukin Yu. V. , Naboikin Yu. V. , Rudenko E. N. , Samartsev V. V. , Silaeva N. B. , Sheibut Yu. E.
Published: December 2024

A theory of optical Dicke superradiation in an extrinsic crystal is constructed taking into account the active role of phonons under conditions of local heating of the sample. The results of the theory are checked in an experiment on the study of optical Dicke superradiation in a diphenyl crystal with pyrene; a series of physical parameters which characterize the electron-phonon interaction and pseudolocalized phonons is established. The lifetimes of nonequilibrium resonance phonons under conditions of local heating of the sample τ′ph = 8.34 · 10−2 sec, the number of resonance oscillatory modes m = 34, the velocity of pseudolocalized phonons u = 1.61 · 104, and the effective temperature of local heating ΔTeff = 0.25 K. Under simplifying assumptions it is established that the specific heat capacity of the sample is of the order of 1 J/kg · deg.
Origin of “high-temperature” oscillations of kinetic coefficients
Authors: Bogod Yu. A.
Published: December 2024

An explanation is provided for the “high-temperature” oscillations of the kinetic coefficients in a magnetic field. The qualitative treatment is in good agreement with experimental results.
A one-dimensional electron system on liquid helium
Authors: Kovdrya Yu. Z. , Monarkha Yu. P.
Published: December 2024

We discuss the possibility of producing a one-dimensional electron system on liquid helium that is sufficiently uniform and pure. The proposal utilizes the curvature of the surface of helium flowing in parallel channels in a dielectric substrate. We compute the mean free path length of electrons in such a system. Conclusions are drawn concerning possible localization of carriers along the direction of their quasi-free motion. We take into account scattering by helium atoms in the gas, by thermal excitations of the liquid surface (ripplons), and by the Coulomb interactions of the electrons with one another.
Calculation of the characteristics of the Fermi surface of arsenic and their pressure variations
Authors: Pospelov Yu. A. , Grachev G. S.
Published: December 2024

A precise calculation of the characteristics (including differential characteristics) of the Fermi surface of arsenic and their variations under pressure to P = 10 kbar is carried out for the first time. The calculations are carried out in the Falicov–Lin pseudopotential scheme. The results of the calculations of the characteristics of the As Fermi surface at standard pressure and their variations with pressure are in good agreement with the experimental data. The calculations yield a number of nontrivial distinctive features in the electronic structure of As, specifically the existence of two saddle points in the interior of the γ-necks, which necessarily includes two near-pressure (P∼2−3 kbar) topological phase transitions of order 2 1/2, when these necks are initially broken on two sides, and then their isolated central part vanishes.
The short-range structure and properties of liquid oxygen
Authors: Brodyanskiĩ A. P. , Freĩman Yu. A.
Published: December 2024

An analysis has been carried out of the thermal and magnetic properties of liquid oxygen near the melting temperature. It is suggested, on the basis of calculation of the saturated vapor pressure and of the magnetic susceptibility, that the γ phase structure is preserved in liquid oxygen in the form of a short-range order. An explanation is given of the anomalously low values of the volume jump on melting, of the entropy of melting and of the saturated vapor pressure at the triple point.
Dynamic internal orbital momentum in He3-A
Authors: Sonin É. B.
Published: December 2024

The internal orbital angular momentum of the A phase of He3, determining the inertia in the equation describing the orbital motion, is discussed. The existing microscopic theory cannot determine its magnitude uniquely owing to the uncertainty of the contribution of boojums (points on the Fermi surface, where the gap vanishes). Additional considerations (existence of hydrodynamic Lagrangian and local law of conservation of momentum) indicates that the magnitude of the moment is large, while the anomalous terms ∼1 (curl 1·1) do not occur in the superfluid current at T = 0.
Influence of a magnetic field on the stability of amorphous ytterbium films
Authors: Kuz’menko V. M. , Vladychkin A. N. , Sudovtsov A. I.
Published: December 2024

The effect of initiation of the crystallization of amorphous films of ytterbium by a magnetic field directed perpendicular to the plane of the film has been investigated. It is assumed that the magnetic field brings about the formation in the film of the initial crystalline “domain.” The subsequent transition takes place in accordance with the well known avalanche (explosive) crystallization mechanism.
Nonlinear phenomena of a supercritical water heated channel natural circulation loop
Authors: Lee Jin Der , Chen Shao Wen
Published: December 2024

The passive feature of a supercritical natural circulation loop (NCL) has promising applications in various fields. The nonlinear natures of a NCL using supercritical water are explored by a dimensionless dynamic model developed in this study, particularly regarding the occurrence of instability. The results demonstrate that the outlet flow resistance of the heated channel will significantly influence the stability and nonlinear behaviors of this supercritical water NCL. Complex nonlinear phenomena would take place in the system while the heated channel is subject to a relatively large outlet flow resistance. A route toward chaotic oscillation can be evolved from periodic oscillations by means of period-doubling bifurcations. The examinations by fast Fourier transform analysis and sensitivity to initial conditions further confirm the existence of chaotic oscillation. The bifurcation phenomena can be inspected by the variations in the fundamental dimensionless frequencies of periodic oscillations. In addition, the indication of period three point implies that innumerable periodic and chaotic kinds of nonlinear oscillations can prevail in the unstable area of this supercritical water NCL under some specific operating conditions.
Conservation of symbiotic signaling since the most recent common ancestor of land plants
Authors: Vernié Tatiana , Rich Mélanie , Pellen Tifenn , Teyssier Eve , Garrigues Vincent , Chauderon Lucie , Medioni Lauréna , van Beveren Fabian , Libourel Cyril , Keller Jean , Girou Camille , Lefort Corinne , Le Ru Aurélie , Martinez Yves , Reinhardt Didier , Kodama Kyoichi , Shimazaki Shota , Morel Patrice , Kyozuka Junko , Mbengue Malick , Vandenbussche Michiel , Delaux Pierre-Marc
Published: December 2024

Plants have colonized lands 450 million years ago. This terrestrialization was facilitated by developmental and functional innovations. Recent evo-devo approaches have demonstrated that one of these innovations was the mutualistic arbuscular mycorrhizal symbiosis (AMS). The genetic pathways that have been involved in the establishment and functioning of AMS since its evolution remain poorly described. Here, we found that intracellular colonization by AM fungi induces a transcriptional reporter of the common symbiosis pathway, well-described in angiosperms, in the liverwort
Marchantia paleacea
. Mutants of either of the three main genes of this pathway,
SYMRK
,
CCaMK,
and
CYCLOPS,
disrupt the ability of
M. paleacea
to associate with AM fungi. Finally, overexpressing gain-of-function CCaMK or CYCLOPS leads to convergent transcriptomic signatures that partially overlap with AMS. Altogether, our data indicate that plants have maintained three genes of the common symbiotic pathway to support symbiotic interactions since their most recent common ancestor.
The carnivorous plant
Genlisea
harnesses active particle dynamics to prey on microfauna
Authors: Martín-Roca José , Barriuso G. C. Miguel , Martínez Fernández Raúl , Betterelli Giuliano Camila , Zhang Rongjing , Valeriani Chantal , Wilson Laurence G.
Published: December 2024

Carnivory in plants is an unusual trait that has arisen multiple times, independently, throughout evolutionary history. Plants in the genus
Genlisea
are carnivorous and feed on microorganisms that live in soil using modified subterranean leaf structures (rhizophylls). A surprisingly broad array of microfauna has been observed in the plants’ digestive chambers, including ciliates, amoebae, and soil mites. Here, we show, through experiments and simulations, that
Genlisea
exploit active matter physics to “rectify” bacterial swimming and establish a local flux of bacteria through the structured environment of the rhizophyll toward the plant’s digestion vesicle. In contrast, macromolecular digestion products are free to diffuse away from the digestion vesicle and establish a concentration gradient of carbon sources to draw larger microorganisms further inside the plant. Our experiments and simulations show that this mechanism is likely to be a localized one and that no large-scale efflux of digested matter is present.
Moiré magnetism and moiré excitons in twisted CrSBr bilayers
Authors: Liu Junyi , Zhang Xu , Lu Gang
Published: December 2024

Moiré excitons and moiré magnetism are essential to semiconducting van der Waals magnets. In this work, we perform a comprehensive first-principles study to elucidate the interplay of electronic excitation and magnetism in twisted magnetic CrSBr bilayers. We predict a twist-induced quantum phase transition for interlayer magnetic coupling and estimate the critical twist angle below which moiré magnetism with mixed ferromagnetic and antiferromagnetic domains could emerge. Localized one-dimensional moiré excitons are stable if the interlayer coupling is ferromagnetic and become unstable if the coupling turns to antiferromagnetic. Exciton energy modulation by magnons is estimated and dependence of exciton oscillator strength on the twist angle and interlayer coupling is analyzed. An orthogonally twisted bilayer is revealed to exhibit layer-dependent, anisotropic optical transitions. Electric field is shown to induce net magnetic moments in moiré excitons, endowing them with exceedingly long lifetimes. Our work lays the foundation for using magnetic moiré bilayers in spintronic, optoelectronic, and quantum information applications.
Stochastic morphological swings in
Hydra
regeneration: A manifestation of noisy canalized morphogenesis
Authors: Agam Oded , Braun Erez
Published: December 2024

Animal morphogenesis, the development of an organism’s body form, is commonly perceived as a directed and almost deterministic process. However, noise and stochastic fluctuations are ubiquitous in biological systems. The questions on the role of fluctuations in morphogenesis and what ensures the robustness of this process under noisy conditions remain elusive. Here, we utilize
Hydra
regeneration, subjected to an external electric field, to provide unique insights into these questions. We found that during
Hydra
morphogenesis, a phase can be induced where fluctuations lead to
stochastic morphological swings,
back and forth, between a nearly spherical structure (the incipient tissue’s state) and an elongated cylindrical shape (the final body form of a mature
Hydra
). Despite these prolonged swings, the tissue regenerates into a normal
Hydra
. The stochastic transitions between two well-defined shapes imply that morphological development occurs through an activation process. Indeed, by introducing a periodic perturbation through modulation of the electric field, we were able to demonstrate morphogenesis dynamics with characteristics of
stochastic resonance
—the tissue’s response to the perturbation displayed a resonance-like behavior as a function of the noise level. Our findings add a dynamic layer to the problem of morphogenesis and offer an unconventional physical framework based on an activation transition in a slowly varying double-well potential that ensures a canalized regeneration of the body form under fluctuations.
Elucidation of a distinct photoreduction pathway in class II
Arabidopsis thaliana
photolyase
Authors: Zhou Zhongneng , Chen Zijing , Kang Xiu-Wen , Ding Bei , Zou Shuhua , Tang Siwei , Zhou Yalin , Wang Bingyao , Zhong Dongping
Published: December 2024

Class II photolyases (PLs) are a distant subclade in the photolyase/cryptochrome superfamily, displaying a unique Trp–Tyr tetrad for photoreduction and exhibiting a lower quantum yield (QY) of DNA repair (49%) than class I photolyases (82%) [M. Zhang, L. Wang, S. Shu, A. Sancar, D. Zhong,
Science
354
, 209–213 (2016)]. Using layer-by-layer mutant design and femtosecond spectroscopy, we have successfully determined the rates of electron transfer and proton transfer, driving force, and reorganization energy for nine elementary steps involved in the initial photoreduction of class II
Arabidopsis thaliana
photolyase (AtPL), thereby constructing the photoreduction network specific to class II PLs. Several dynamic features have been revealed including a slow-rise (172 ps) and fast-decay (26 ps) kinetics between the excited lumiflavin and adenine groups within the flavin adenine dinucleotide cofactor, a slower electron transfer (ET) (22 ps) between the excited lumiflavin and the nearest Trp in the Trp triad (W
a
) as compared to reported class I PL (0.8 ps), and a rapid deprotonation of the distal Trp in the Trp triad (W
c
). Most strikingly, we captured a slightly energetically unfavorable ET step between W
a
and the center Trp (W
b
), as opposed to the decreasing reduction potential observed in class I PL that drives the electron flow unidirectionally. Such an energetically uphill ET step leads to a lower photoreduction quantum yield (~34%) in class II AtPL compared to that of class I PL (~45%), raising an important question on the evolutionary implications of various photoreduction networks in photolyases and cryptochromes.
Structures of methane and ammonia monooxygenases in native membranes
Authors: Tucci Frank J. , Rosenzweig Amy C.
Published: December 2024

Methane- and ammonia-oxidizing bacteria play key roles in the global carbon and nitrogen cycles, respectively. These bacteria use homologous copper membrane monooxygenases to accomplish the defining chemical transformations of their metabolisms: the oxidations of methane to methanol by particulate methane monooxygenase (pMMO) and ammonia to hydroxylamine by ammonia monooxygenase (AMO), enzymes of prime interest for applications in mitigating climate change. However, investigations of these enzymes have been hindered by the need for disruptive detergent solubilization prior to structure determination, confounding studies of pMMO and precluding studies of AMO. Here, we overcome these challenges by using cryoEM to visualize pMMO and AMO directly in their native membrane arrays at 2.4 to 2.8 Å resolution. These structures reveal details of the copper centers, numerous bound lipids, and previously unobserved components, including identifiable and distinct supernumerary helices interacting with pMMO and AMO, suggesting a widespread role for these helices in copper membrane monooxygenases. Comparisons between these structures, their metallocofactors, and their unexpected protein–protein interactions highlight features that may govern activity or the formation of higher-order arrays in native membranes. The ability to obtain molecular insights within the native membrane will enable further understanding of these environmentally important enzymes.
Structure-guided design and synthesis of C22- and C32-modified FK520 analogs with enhanced activity against human pathogenic fungi
Authors: Dome Patrick A. , Jeong Pyeonghwa , Nam Gibeom , Jang Hongjun , Rivera Angela , Floyd Averette Anna , Park Eunchong , Liao Tzu-Chieh , Ciofani Maria , Wu Jianli , Chi Jen-Tsan Ashley , Venters Ronald A. , Park Hyun-Ju , Steinbach William J. , Juvvadi Praveen R. , Heitman Joseph , Hong Jiyong
Published: December 2024

Invasive fungal infections are a leading cause of death worldwide. Translating molecular insights into clinical benefits is challenging because fungal pathogens and their hosts share similar eukaryotic physiology. Consequently, current antifungal treatments have limited efficacy, may be poorly fungicidal in the host, can exhibit toxicity, and are increasingly compromised by emerging resistance. We have established that the phosphatase calcineurin (CaN) is required for invasive fungal disease and an attractive target for antifungal drug development. CaN is a druggable target, and there is vast clinical experience with the CaN inhibitors FK506 and cyclosporin A (CsA). However, while FK506 and its natural analog FK520 exhibit antifungal activity, they are also immunosuppressive in the host and thus not fungal-selective. We leverage our pathogenic fungal CaN-FK506-FKBP12 complex X-ray structures and biophysical data to support structure-based ligand design as well as structure–activity relationship analyses of broad-spectrum FK506/FK520 derivatives with potent antifungal activity and reduced immunosuppressive activity. Here, we apply molecular docking studies to develop antifungal C22- or C32-modified FK520 derivatives with improved therapeutic index scores. Among them, the C32-modified FK520 derivative JH-FK-44 (
7
) demonstrates a significantly improved therapeutic index compared to JH-FK-08, our lead compound to date. NMR binding studies with C32-derivatives are consistent with our hypothesis that C32 modifications disrupt the hydrogen bonding network in the human complex while introducing favorable electrostatic and cation–π interactions with the fungal FKBP12 R86 residue. These findings further reinforce calcineurin inhibition as a promising strategy for antifungal therapy.
Pure-quartic soliton molecules in normal fourth-order dispersion regimes based on spectral filtering effect
Authors: Shen 申 Han-Yang 翰阳 , Lan 蓝 Rui-Bo 睿博 , Hu 胡 Hong-Bin 洪彬 , Li 李 Yang 阳 , Zhou 周 Rui 瑞 , Zhang 张 Zu-Xing 祖兴
Published: December 2024

Recent theoretical verification of self-similar and dissipative pure-quartic solitons (PQSs) emphasized the similarity between PQS lasers and conventional fiber lasers, but the unique equilibrium mechanism hinders the formation of PQS molecules in normal fourth-order dispersion (FOD) regimes. In this paper, we investigated the effect of filters on shaping PQSs in normal FOD based on a passively mode-locked fiber laser model. A bandpass filter eliminates the time pedestal of dissipative PQSs, thus realizing a multi-pulsing state. When the filter bandwidth is appropriate, the effective spectral filtering effect can lower the pulse splitting threshold and enable the coherent restoration from chaotic PQSs to PQS molecules. Additionally, changing the central wavelength of the filter can generate PQSs and PQS molecules with asymmetric intensity distributions. These results are important guides for the manipulation of PQSs and the construction of high repetition-frequency fiber lasers.
A novel topology with sextuple phase shift modulation (SPSM) based multi level dual active bridge converter for electric vehicle applications
Authors: Ul Haq Khurshid , Ilahi Bakhsh Farhad , Chandra Sekhar Obbu
Published: December 2024

Multi-level dual active bridge (MLDAB) bidirectional DC-DC converters often encounter harmonic issues in the high-frequency link (HFL) during power conversion, irrespective of the modulation scheme employed. These harmonics in the HFL inductor current result in elevated RMS current, thereby increasing current stress on the switching devices. Furthermore, the presence of harmonics leads to higher operating temperatures in the high-frequency transformer (HFT) and other associated components, ultimately compromising system efficiency. To address the limitations of conventional MLDAB converters, this paper proposes a novel topology incorporating sextuple phase shift modulation (SPSM) based MLDAB converter. The proposed approach significantly reduces the harmonic content in the HFL inductor current, leading to lower power losses and improved overall efficiency. Further, this paper provides a comparative evaluation against the conventional quintuple phase shift (QPS) modulation based MLDAB converter. The results demonstrate that the proposed topology with novel modulation based MLDAB converter effectively minimizes harmonics in the HFL inductor current and delivers higher efficiency compared to the conventional modulation based MLDAB converter. This makes the proposed topology with novel SPSM based MLDAB converter a superior solution for DC-DC converter applications. Also, the results of the proposed MLDAB converter has been validated through real-time results using an OPAL-RT hardware-in-the-loop emulator.
Accelerated development of multi-component alloys in discrete design space using Bayesian multi-objective optimisation
Authors: Mamun Osman , Bause Markus , Ebna Hai Bhuiyan Shameem Mahmood
Published: December 2024

Bayesian optimisation (BO) protocols grounded in active learning (AL) principles have gained significant recognition for their ability to efficiently optimize black-box objective functions. This capability is critical for advancing autonomous and high-throughput materials design and discovery processes. However, the application of these protocols in materials science, particularly in the design of novel alloys with multiple targeted properties, remains constrained by computational complexity and the absence of reliable and robust acquisition functions for multiobjective optimisation. Recent advancements have demonstrated that expected hypervolume-based geometrical acquisition functions outperform other multiobjective optimisation algorithms, such as Thompson Sampling Efficient Multiobjective optimisation and pareto efficient global optimisation (parEGO), in both performance and speed. This study evaluates several leading multiobjective BO acquisition functions–namely, parallel expected hypervolume improvement (qEHVI), noisy qEHVI, parallel parEGO, and parallel noisy parEGO (qNparEGO)–in optimizing the physical properties of multi-component alloys. Our findings highlight the superior performance of the qEHVI acquisition function in identifying the optimal Pareto front across 1-, 2-, and 3-objective aluminum alloy optimisation problems, all within a constrained evaluation budget and reasonable computational cost. Furthermore, we explore the impact of various surrogate model optimisation methods from both computational cost and efficiency perspectives. Finally, we demonstrate the effectiveness of a pool-based AL protocol in expediting the discovery process by executing multiple computational and experimental campaigns in each iteration. This approach is particularly advantageous for deployment in massively parallel high-throughput synthesis facilities and advanced computing architectures.
Effects of early palliative care intervention on medical resource use among end-of-life patients
Authors: Lin Chia-Chia , Ho Tsing-Fen , Lin Chang-Hung , Tsai Nu-Man , Kuo Yu-Hung , Chien Ju-Huei
Published: December 2024

Background

In Taiwan, as the population ages, palliative care services (PCS) have expanded significantly to include comprehensive benefit plans for critically ill individuals, supported by reimbursements from the National Health Insurance program. However, incorporating palliative care into the medical management of these patients presents several challenges. We aim to evaluate the effects of palliative care interventions on medical resources in end-of-life scenarios, to promote earlier palliative care access and provide high-quality healthcare services for patients.

Methods

A total of 2202 patients were included in this study. Primary diagnosis and referral for PCS were assessed using ICD-10 and HNI code. All study subjects were divided into three groups: patients who did not receive PCS (no-PCS), patients who received PCS before their final hospital admission (PCS-before), and patients who received PCS after their final admission (PCS-after). We evaluated (i) the effects of PCS on eight medical resource utilization outcomes within the 30 days preceding death and (ii) the effects of early intervention on two major diseases.

Results

Initiating PCS before a patient’s last hospital admission was associated with less aggressive medical interventions in the 30 days before death, including reduced length of intensive care unit (ICU) [odds ratio (OR) = 0.25], and rates of endotracheal intubation (OR = 0.12), respiratory ventilator support (OR = 0.20), cardiopulmonary resuscitation (OR = 0.18), and blood transfusion (OR = 0.65). Among patients with cancer and lung diseases, those who received PCS prior to their final hospitalization of over 14 days experienced reduced hospitalization duration (OR = 0.52 and 0.24, respectively). Patients with lung disease also had significantly lower odds of ICU stays (OR = 0.44) and respiratory ventilation (OR = 0.33).

Conclusion

The timing of palliative care intervention critically impacts on duration of hospitalization and ICU stay and the need for intubation procedures or cardiopulmonary resuscitation. The findings can help the government and medical providers in developing comprehensive palliative care policies and programs to improve care quality and patient rights.
Advancing an Embodied Understanding of Accessibility for Persons with Disabilities
Authors: Ferri Delia
Published: December 2024

The UN Convention on the Rights of Persons with Disabilities (CRPD) includes accessibility among its general principles and articulates it in Article 9. Further, accessibility obligations are included in several other provisions of the Convention. In that regard, the CRPD recognizes the significance of accessibility as an enabling factor, and as a precondition for persons with disabilities to participate fully in society. Embracing an interdisciplinary approach, and on foot of arts-based research in the form of inclusive dance, this article aims to re-construe the inherent dimensions of accessibility as a normative concept. It puts forward an ‘embodied understanding’ of accessibility with a view of advancing existing legal analysis and adding to traditional cognitive ways of knowing. On the whole, this article identifies three inherent and intertwined facets of such embodied understanding of accessibility—namely, respect for difference, collaboration and care, and layered complexity. It argues that this  embodied understanding may help achieving the overall paradigm shift of the CRPD.