bluuebunny/crossref_metadata_2025 huggingface dataset:
Unravelling the factors affecting the stability and reactivity of dehydro-pyrazole, isothiazole and isoxazole radical isomers: a computational study
Authors: Mahadevan Anjali , Kumar Piyush , Butt Shabana , Velloth Archana , Venkataramani Sugumar
Published: May 2024

Kinetic and thermodynamic stability of the radical isomers of dehydro-pyrazole, isoxazole and isothiazole have been explored and the crucial factors influencing them are predicted.
Solar-driven pH-responsive oil–water separation membranes for effective oil–water emulsion separation
Authors: Li Ting-Ting , Jia Mengdan , Li Shuxia , Zhang Ying , Wang Xiaomeng , Chu Sheng , Shiu Bing-Chiuan , Lou Ching-Wen , Lin Jia-Horng
Published: May 2024

The membrane (PP–PPy–pHR) prepared in this paper automatically switches the wettability according to the change of pH to separate oil water emulsions. It has great potential for intelligent response in oil water separation.
Structural basis for Cu(ii) metallocycle hexamer formation
Authors: Bracken Matthew L. , Fernandes Manuel A. , Wamwangi Daniel , Munro Orde Q.
Published: May 2024

A structural basis for Cu(ii) metallocycle formation is presented. Design requirements for the NNN bis-aryl pincer ligand have been delineated, paving the way for development of a novel class of metal–organic frameworks.
Synthesis, and optical and electrochemical properties of 1,1′,3,3′-tetraaryl-4,4′-bibenzo[c]thiophene derivatives with the same or different aryl substituents on the thiophene rings
Authors: Hara Yasuto , Kozuka Kumpei , Imato Keiichi , Akiyama Seiji , Ishida Mio , Ooyama Yousuke
Published: May 2024

This work provides facile synthetic methods for 1,1′,3,3′-tetraaryl-4,4′-bibenzo[c]thiophene derivatives with the same or different aryl substituents on the thiophene rings and useful methods to adjust their optical and electrochemical properties.
Studies on the selective synthesis of diorganyl diselenides using potassium hydroxide and mechanistic investigations of the reaction pathway
Authors: Lee Sang Hyup , Lim Yoo Jin , Kim Chorong , Kim Ye Eun , Cho Hyunsung
Published: May 2024

The selective synthesis of K2Se2 diorganyl diselenides 1, and the investigation of reaction pathways.
A divergent one-pot thiol-Michael strategy to create β-thiophene-fused porphyrins
Authors: Singh Jagmeet , Singh Abhijeet , Nath Mahendra
Published: May 2024

A one-pot thiol-Michael strategy was developed for the construction of diverse β-thiophene-fused 5,10,15,20-tetraarylporphyrins. These new porphyrins displayed a modest red-shifted electronic absorption in contrast to meso-tetraarylporphyrins.
An emerging role for tissue plasticity in developmental precision
Authors: Naganathan Sundar Ram
Published: May 2024

Reproducible tissue morphology is a fundamental feature of embryonic development. To ensure such robustness during tissue morphogenesis, inherent noise in biological processes must be buffered. While redundant genes, parallel signaling pathways and intricate network topologies are known to reduce noise, over the last few years, mechanical properties of tissues have been shown to play a vital role. Here, taking the example of somite shape changes, I will discuss how tissues are highly plastic in their ability to change shapes leading to increased precision and reproducibility.
ATP binding to Nerve Growth Factor (NGF) and pro-Nerve Growth Factor (proNGF): an endogenous molecular switch modulating neurotrophins activity
Authors: Paoletti Francesca
Published: May 2024

ATP has recently been reconsidered as a molecule with functional properties which go beyond its recognized role of the energetic driver of the cell. ATP has been described as an allosteric modulator as well as a biological hydrotrope with anti-aggregation properties in the crowded cellular environment. The role of ATP as a modulator of the homeostasis of the neurotrophins (NTs), a growth factor protein family whose most known member is the nerve growth factor (NGF), has been investigated. The modulation of NTs by small endogenous ligands is still a scarcely described area, with few papers reporting on the topic, and very few reports on the molecular determinants of these interactions. However, a detailed atomistic description of the NTs interaction landscape is of urgent need, aiming at the identification of novel molecules as potential therapeutics and considering the wide range of potential pharmacological applications for NGF and its family members. This mini-review will focus on the unique cartography casting the interactions of the endogenous ligand ATP, in the interaction with NGF as well as with its precursor proNGF. These interactions revealed interesting features of the ATP binding and distinct differences in the binding mode between the highly structured mature NGF and its precursor, proNGF, which is characterized by an intrinsically unstructured domain. The overview on the recent available data will be presented, together with the future perspectives on the field.
Reprogrammed mitochondria: a central hub of cancer cell metabolism
Authors: Ciccarone Fabio , Ciriolo Maria Rosa
Published: May 2024

Mitochondria represent the metabolic hub of normal cells and play this role also in cancer but with different functional purposes. While cells in differentiated tissues have the prerogative of maintaining basal metabolism and support the biosynthesis of specialized products, cancer cells have to rewire the metabolic constraints imposed by the differentiation process. They need to balance the bioenergetic supply with the anabolic requirements that entail the intense proliferation rate, including nucleotide and membrane lipid biosynthesis. For this aim, mitochondrial metabolism is reprogrammed following the activation of specific oncogenic pathways or due to specific mutations of mitochondrial proteins. The main process leading to mitochondrial metabolic rewiring is the alteration of the tricarboxylic acid cycle favoring the appropriate orchestration of anaplerotic and cataplerotic reactions. According to the tumor type or the microenvironmental conditions, mitochondria may decouple glucose catabolism from mitochondrial oxidation in favor of glutaminolysis or disable oxidative phosphorylation for avoiding harmful production of free radicals. These and other metabolic settings can be also determined by the neo-production of oncometabolites that are not specific for the tissue of origin or the accumulation of metabolic intermediates able to boost pro-proliferative metabolism also impacting epigenetic/transcriptional programs. The full characterization of tumor-specific mitochondrial signatures may provide the identification of new biomarkers and therapeutic opportunities based on metabolic approaches.
A broken debris cascade as a possible source of hot dust emission in transitioning planet-forming disks
Authors: Swinkels N. , Dominik C.
Published: May 2024

Context. Planet-forming disks go from gas-rich, massive disks made of dust and gas into planetary systems containing only small amounts dust. This dust is produced by collisions between smaller planetary objects, such as planetesimals, asteroids, and comets. Traditionally, we talk about protoplanetary (age ~1 Myr), transitional (~5-10 Myr), and debris disks (~10-hundreds of Myr) even though the overlap between these phases may be relevant.

Aims. We aim to show that in the transition phase of a disk, when the gas surface densities are reduced but not yet negligible, a seemingly small amount of collisional activity may lead to the production of dust on a level that is observationally relevant by creating regions characterised by an optical depth of 1 or above. In particular, we aim to show that the hot dust emission component of transitional disks may in fact be debris dust that has been produced in such collisions.

Methods. We developed an analytical model to derive the conditions in which observationally relevant amounts of dust can be produced. We focussed on the effect of the gas surface density during the transition phase of a disk from fully gas-dominated to the gas-poor debris stage.

Results. We show that the decrease in the gas surface density has an important effect. It allows for smaller planetesimals to become collisional, initiating a cascade. At the same time, small particles are not destroyed by collisions. This interrupted cascade is critical in terms of preserving the produced dust for significant time intervals, allowing for a seemingly minor amount of planetesimal collisions to be effective in producing detectable amounts of dust.

Conclusions. The warm emission of low amounts of dust in many transitional planet-forming disks might be caused entirely by second-generation dust, exposing planetary material at a much earlier time than the age that debris disks have traditionally been characterised by.
Schulterschmerzen im Wandel? Psychosoziale Faktoren vor und nach
operativen Eingriffen
Authors: Kalmring Matthias
Published: May 2024

Neben biomechanischen wurden psychosoziale Einflüsse auf muskuloskelettale
Beschwerden in Untersuchungen der letzten Jahre häufig evaluiert. Auch bei
Schulterschmerzen konnte die Präsenz dieser Faktoren in Studien beobachtet
werden.

Ziel dieses narrativen Reviews war es, einen möglichen Zusammenhang von
psychosozialen Aspekten und Schulterschmerzen in einem prä- und postoperativen
Zeitraum darzustellen. Für die Literatursuche wurde eine computergestützte
Recherche in den Datenbanken PubMed und Cochrane Library für den Zeitraum
2018–2023 durchgeführt.

Die eingeschlossenen systematischen Übersichtsarbeiten postulieren einen
negativen Einfluss von psychosozialen Aspekten auf präoperative
Schulterschmerzen. Postoperativ hingegen sind die Schlussfolgerungen der
integrierten Arbeiten weniger übereinstimmend.

Auf Basis der ermittelten Erkenntnisse sollten Kliniker*innen die emotionale
Gesundheit in der Behandlungsplanung im präoperativen Zeitraum
berücksichtigen.
Fuchs-Syndrom
Authors: Löbig Tina , Grigorjan Philipp , Meinig Robert , Kaatz Martin
Published: May 2024

Das Fuchs-Syndrom wird auch als die Schleimhautvariante eines Erythema exsudativum multiforme majus bezeichnet. Auslöser können Medikamente, Impfungen oder Infektionen sein 1
2
3
4. Wir berichten über einen sonst gesunden 22-jährigen Patienten mit ausgeprägter erosiver Konjunktivitis, Stomatitis und Urethritis, der zudem einzelne atypische Kokarden aufwies. Aufgrund der möglichen Residuen der Erkrankung ist eine konsequente sofortige interdisziplinäre Therapie notwendig.
Connecting place branding to social and governance constructs in Johannesburg, South Africa
Authors: Mbinza Zenzile E.
Published: May 2024

Employing Johannesburg as a case, this paper explores the intersections of place branding with pervasive, often taken-for-granted phenomena, including culture, democracy, urban governance, gender and public diplomacy. The paper argues that these intersections are seldom the subject of place branding scholarship, even in the global North, where the discipline receives considerable inquiry. The paper undertakes a multidisciplinary review of the literature to situate place branding and its relation to culture, democracy, urban governance and public diplomacy. Delving deeper into the literature surrounding place branding and its relation to culture, democracy, urban governance and public diplomacy reveals the need for a more comprehensive and nuanced approach to understanding the impact of place branding. By situating place branding within these broader contexts, the paper opens new avenues for inquiry and challenges the predominant lenses through which place branding has been traditionally studied. Through delving deeper into place branding scholarship, the paper introduces a new term, “mentrification”, to enhance descriptions of placeholder disengagement and to add to the emerging lexicon of place branding. Ultimately, this paper serves as a valuable contribution by offering a new outlook on the complexities of place branding, moving beyond traditional efficacy measurements and definitional issues to delve into the deeper layers of its impact on society.
Low-donor content approach to achieve sensitive narrowband organic photodetectors
Authors: Zhang Tianyi , Schröder Jonas , Wolansky Jakob , Leo Karl , Benduhn Johannes
Published: May 2024

Narrowband near-infrared (NIR) detectors are key components for various modern biomedical, agricultural, astronomical sensing as well as monitoring applications. Typically, a narrowband organic photodetector (OPD) requires thick junctions or additional optical elements, which are either tedious or cost-ineffective. Here, we adopt the low-donor content strategy in our thin-film device to realize narrowband spectral features. The much-mitigated aggregation drastically improves shunt resistance and dark current while maintaining decent photocurrent. Upon further dilution, a thinner electron transporting layer can effectively shorten the transient response to reach fast speed. n-i-p and p-i-n device configurations are also compared, which exhibits drastic changes for low-donor content OPDs. The 5 wt% D:A thin-film bulk-heterojunction OPD presents an external quantum efficiency of 49.3% at 770 nm with zero bias, and a high thermal-noise calculated specific detectivity (D*) of 1.0 × 1013 Jones (7.1 × 1012 Jones based on noise spectral density) at 0 V. Such narrowband OPD also shows a fast NIR response of 530 ns/840 ns (rise/fall) when operated at 10 kHz. The results reveal the potential for low-donor-content blend in realizing narrowband photodetection.
Catalyzing hydrogen production: Exploring plasmonic effects in self-assembled CuO/Cu2O thin films via pulsed laser deposition
Authors: Ranjan Ashish K. , Jha Pardeep K. , Jha Priyanka A. , Singh Prabhakar
Published: May 2024

Plasmonic catalysis triggers the dissociation of H2 or adsorbed O2 (sluggish processes) under continuous wave excitation via plasmon decay. This is coupled to interband or intraband excitation of d-band or sp-band, respectively, to levels above fermi level of metals. Here, we have studied the plasmonic and photocatalytic behavior in an environment friendly medium with AM 1.5 G sunlight of CuO/Cu2O thin films fabricated by pulsed laser deposition technique in vacuum with varying thickness. We have achieved ∼0.59 kmol h−1g−1H2 production in the CuO/Cu2O film with a thickness of ∼27 nm. The role of plasmons with metal–dielectric and semiconductor–semiconductor interfaces is conducted through both experimental and theoretical approaches. The results suggest that the impact of plasmonic catalysis/synthesis is subject to the dimension, composition, and band alignment of two interface materials.
Escape from textured adsorbing surfaces
Authors: Scher Yuval , Reuveni Shlomi , Grebenkov Denis S.
Published: May 2024

The escape dynamics of sticky particles from textured surfaces is poorly understood despite importance to various scientific and technological domains. In this work, we address this challenge by investigating the escape time of adsorbates from prevalent surface topographies, including holes/pits, pillars, and grooves. Analytical expressions for the probability density function and the mean of the escape time are derived. A particularly interesting scenario is that of very deep and narrow confining spaces within the surface. In this case, the joint effect of the entrapment and stickiness prolongs the escape time, resulting in an effective desorption rate that is dramatically lower than that of the untextured surface. This rate is shown to abide a universal scaling law, which couples the equilibrium constants of adsorption with the relevant confining length scales. While our results are analytical and exact, we also present an approximation for deep and narrow cavities based on an effective description of one-dimensional diffusion that is punctuated by motionless adsorption events. This simple and physically motivated approximation provides high-accuracy predictions within its range of validity and works relatively well even for cavities of intermediate depth. All theoretical results are corroborated with extensive Monte Carlo simulations.
Simulation of neoclassical heavy impurity transport in ASDEX Upgrade with applied 3D magnetic fields using the nonlinear MHD code JOREK
Authors: Korving S. Q. , Mitterauer V. , Huijsmans G. T. A. , Loarte A. , Hoelzl M. ,   JOREK Team,   ASDEX Upgrade team
Published: May 2024

Accumulation of heavy impurities in the tokamak core is detrimental for its performance and can lead to disruption of the plasma. In small to medium-sized tokamaks the effective neoclassical transport in the pedestal is typically oriented radially inward. In larger tokamaks—e.g., ITER—where the temperature gradient is higher and density gradients are lower due to the need to operate in a radiative divertor regime, the neoclassical transport is predicted to be outwards. The models are derived for axisymmetric quasi-steady-state plasmas. Applied 3D magnetic fields, i.e., Resonant Magnetic Perturbation (RMPs) as they are used to suppress Edge Localized Modes (ELMs), have experimentally been observed in AUG to enhance the outflow of heavy impurities in the pedestal. There is no model that can predict neoclassical heavy impurity transport in these ergodized 3D magnetic fields self-consistently. In this contribution, we present our kinetic tungsten transport simulation for an ASDEX Upgrade plasma with applied RMPs. Our model based on Hoelzl et al. [Nucl. Fusion 61, 065001 (2021)], van Vugt et al. [Phys. Plasmas 26, 042508 (2019)], and Korving et al. [Phys. Plasmas 30, 042509 (2023)] utilizes a full-orbit pusher, ionization, recombination, effective line, and continuum radiation and neoclassical collisions with the background plasma. The effective collisional radiative rates are from the OpenADAS database, the neoclassical collision operator uses the framework of Homma et al. [J. Comput. Phys. 250, 206–223 (2013)] and Homma et al. [Nucl. Fusion 56, 036009 (2016)]. We show that the adopted collision operator produces neoclassical transport within a satisfactory degree of accuracy. A sufficiently high RMP current causes an increase in tungsten diffusion in the pedestal by a factor of 2. We compare the average radial transport between axisymmetric and 3D RMP scenarios in the pedestal region. RMPs enhance the pedestal permeability for impurities, which results in enhanced transport. In addition to the enhanced transport, some of W is found to be trapped in 3D potential wells in the scrape-off layer. Due to the lack of suitable diagnostics for W in the pedestal, we investigate and suggest that argon can be an adequate substitute in experiments for model validation and further understanding impurity transport in scenarios with applied 3D magnetic fields. With the newly developed neutral model [Korving et al., Phys. Plasmas 30, 042509 (2023)], we can combine the interaction in the divertor with the 3D RMPs to model the tungsten transport from the divertor toward the core of the plasma.
Molecular beam epitaxy and characterization of ferroelectric quaternary alloy Sc0.2Al0.45Ga0.35N
Authors: Yang Samuel , Wang Ding , Tanim Md Mehedi Hasan , Wang Danhao , Mi Zetian
Published: May 2024

In this study, we demonstrate ferroelectricity in high-quality monocrystalline quaternary alloy ScAlGaN. Sc0.2Al0.45Ga0.35N films are grown by plasma-assisted molecular beam epitaxy and exhibit a surface roughness of 0.5 nm, limited by the roughness of the underlying molybdenum template. Polarization-electric field and positive-up-negative-down measurements reveal unambiguous ferroelectric switching with a coercive field of ∼5.5 MV cm−1 at 10 kHz and high remanent polarization of ∼150 μC cm−2. Time-dependent measurements suggest that the polarization reversal behavior adheres to the Kolmogorov–Avrami–Ishibashi model and follows a scheme of domain nucleation and growth. Detailed piezoresponse force microscopy studies further elucidate the evolution of polarity reversal domains in wurtzite nitride ferroelectrics and support the notion that the growth of inversion domains occurs via an in-plane motion of the domain walls. The realization of functional ferroelectric quaternary alloys in the wurtzite nitride family extends beyond being a technical demonstration. The additional degree of bandgap, band alignment, lattice parameter, and piezoelectric constant tunability achievable through quaternary alloys unveils a vast dimension through which wurtzite nitride ferroelectrics can be optimally engineered for a broad variety of high-performance electronic, optoelectronic, and acoustic devices and systems.
Radiatively cooled magnetic reconnection experiments driven by pulsed power
Authors: Datta R. , Chandler K. , Myers C. E. , Chittenden J. P. , Crilly A. J. , Aragon C. , Ampleford D. J. , Banasek J. T. , Edens A. , Fox W. R. , Hansen S. B. , Harding E. C. , Jennings C. A. , Ji H. , Kuranz C. C. , Lebedev S. V. , Looker Q. , Patel S. G. , Porwitzky A. , Shipley G. A. , Uzdensky D. A. , Yager-Elorriaga D. A. , Hare J. D.
Published: May 2024

We present evidence for strong radiative cooling in a pulsed-power-driven magnetic reconnection experiment. Two aluminum exploding wire arrays, driven by a 20 MA peak current, 300 ns rise time pulse from the Z machine (Sandia National Laboratories), generate strongly driven plasma flows (MA≈7) with anti-parallel magnetic fields, which form a reconnection layer (SL≈120) at the mid-plane. The net cooling rate far exceeds the Alfvénic transit rate (τcool−1/τA−1≫1), leading to strong cooling of the reconnection layer. We determine the advected magnetic field and flow velocity using inductive probes positioned in the inflow to the layer, and inflow ion density and temperature from analysis of visible emission spectroscopy. A sharp decrease in x-ray emission from the reconnection layer, measured using filtered diodes and time-gated x-ray imaging, provides evidence for strong cooling of the reconnection layer after its initial formation. X-ray images also show localized hotspots, regions of strong x-ray emission, with velocities comparable to the expected outflow velocity from the reconnection layer. These hotspots are consistent with plasmoids observed in 3D radiative resistive magnetohydrodynamic simulations of the experiment. X-ray spectroscopy further indicates that the hotspots have a temperature (170 eV) much higher than the bulk layer (≤75 eV) and inflow temperatures (about 2 eV) and that these hotspots generate the majority of the high-energy (>1 keV) emission.
Non-adiabatic excited-state time-dependent GW molecular dynamics (TDGW) satisfying extended Koopmans’ theorem: An accurate description of methane photolysis
Authors: Manjanath Aaditya , Sahara Ryoji , Ohno Kaoru , Kawazoe Yoshiyuki
Published: May 2024

There is a longstanding difficulty that time-dependent density functional theory relying on adiabatic local density approximation is not applicable to the electron dynamics, for example, for an initially excited state, such as in photochemical reactions. To overcome this, we develop non-adiabatic excited-state time-dependent GW molecular dynamics (TDGW) on the basis of the extended quasiparticle theory. Replacing Kohn–Sham orbitals/energies with correlated, interacting quasiparticle orbitals/energies allows the full correspondence to the excited-state surfaces and corresponding total energies, with satisfying extended Koopmans’ theorem. We demonstrate the power of TDGW using methane photolysis, CH4→CH3•+H, an important initiation reaction for combustion/pyrolysis and hydrogen production of methane. We successfully explore several possible pathways and show how this reaction dynamics is captured accurately through simultaneously time-tracing all quasiparticle levels. TDGW scales as O(NB3-4), where NB is the number of basis functions, which is distinctly advantageous to performing dynamics using configuration interaction and coupled cluster methods.
Pillared graphene oxide frameworks for the adsorption and separation of polar protic and aprotic liquid solvents: The cases of pure water, methanol, dimethyl sulfoxide, and dimethyl sulfoxide–water mixtures
Authors: Skarmoutsos Ioannis , Koukaras Emmanuel N. , Klontzas Emmanuel
Published: May 2024

Potential applications of previously synthesized pillared graphene oxide frameworks with phenyldiboronic acid linkers in the field of the adsorption and separation of polar protic and aprotic liquid solvents have been systematically explored using grand canonical Monte Carlo simulations. Particular attention was initially paid to the adsorption of pure liquid water, methanol, and dimethyl sulfoxide. The results obtained a significant increase in the isosteric heat of adsorption at low uptake in the case of dimethyl sulfoxide, which is about 17.9 and 26.8 kJ/mol higher than the values corresponding to methanol and water adsorption. These findings indicated that from a thermodynamic point of view, these pillared graphene oxide frameworks could be used in the separation of dimethyl sulfoxide–water liquid mixtures. Systematic grand canonical Monte Carlo simulations were then subsequently performed for dimethyl sulfoxide–water mixtures, with a low dimethyl sulfoxide concentration. The calculated values of the separation selectivity indicate that these materials could have potential applications in the separation of these mixed liquid solvents. Molecular dynamics simulations performed for a representative adsorbed mixture have revealed a substantial slowing down of the dynamics under confinement, particularly in the case of the hydrogen bonds formed between water and dimethyl sulfoxide.
Advanced fuel fusion, phase space engineering, and structure-preserving geometric algorithms
Authors: Qin Hong
Published: May 2024

Non-thermal advanced fuel fusion trades the requirement of a large amount of recirculating tritium in the system for that of large recirculating power. Phase space engineering technologies utilizing externally injected electromagnetic fields can be applied to meet the challenge of maintaining non-thermal particle distributions at a reasonable cost. The physical processes of the phase space engineering are studied from a theoretical and algorithmic perspective. It is emphasized that the operational space of phase space engineering is limited by the underpinning symplectic dynamics of charged particles. The phase space incompressibility according to the Liouville theorem is just one of many constraints, and Gromov's non-squeezing theorem determines the minimum footprint of the charged particles on every conjugate phase space plane. In this sense and level of sophistication, the mathematical abstraction of phase space engineering is symplectic topology. To simulate the processes of phase space engineering, such as the Maxwell demon and electromagnetic energy extraction, and to accurately calculate the minimum footprints of charged particles, recently developed structure-preserving geometric algorithms can be used. The family of algorithms conserves exactly, on discretized spacetime, symplecticity and thus incompressibility, non-squeezability, and symplectic capacities. The algorithms apply to the dynamics of charged particles under the influence of external electromagnetic fields as well as the charged particle–electromagnetic field system governed by the Vlasov–Maxwell equations.
Interfacial strain induced giant magnetoresistance and magnetodielectric effects in multiferroic BCZT/LSMO thin film heterostructures
Authors: Chatterjee Subhashree , Yadav Kusampal , Mondal Nasiruddin , Kumar Ganga S. , Bhattacharya Dipten , Mukherjee Devajyoti
Published: May 2024

Layered thin films of the ferroelectric perovskite Ba0.85Ca0.15Ti0.9Zr0.1O3 (BCZT) and the ferromagnetic half-metal La0.80Sr0.20MnO3 (LSMO) are well-known multiferroic systems that show promise for spintronic applications. In this work, the structure–property relationships are explored in novel BCZT/LSMO thin film heterostructures with optimized ferroic properties. Epitaxial BCZT/LSMO thin film heterostructures are grown by varying the lattice mismatch strains on single crystal LaAlO3 (LAO) (100) and MgO (100) substrates using the pulsed laser deposition technique. The epitaxial strain in the films gives rise to a tetragonal distortion of the BCZT and LSMO unit cells and significantly affects their magnetotransport and magnetodielectric properties. The BCZT/LSMO/LAO heterostructure exhibits a colossal magnetoresistance effect due to a large out-of-plane tensile strain, which induces enhanced carrier hopping in the LSMO layer as compared to the BCZT/LSMO/MgO film. The larger tetragonal distortion of the BCZT unit cell in BCZT/LSMO/MgO contributes to higher dielectric permittivity, with a greater dielectric maxima temperature and freezing temperature. Magnetodielectric measurements reveal a hitherto unobserved giant magnetodielectric effect in the BCZT/LSMO/MgO film, attributed to a large in-plane strain, which induces interfacial polarization distortion at the interfacial layer. Overall, this work elucidates the unique strain and charge-mediated cross-coupled phenomena of magnetic and electric orders in multiferroic thin film heterostructures, which are critical for their technological applications.
Nonadiabatic dynamics of molecules interacting with metal surfaces: A quantum–classical approach based on Langevin dynamics and the hierarchical equations of motion
Authors: Rudge Samuel L. , Kaspar Christoph , Grether Robin L. , Wolf Steffen , Stock Gerhard , Thoss Michael
Published: May 2024

A novel mixed quantum–classical approach to simulating nonadiabatic dynamics of molecules at metal surfaces is presented. The method combines the numerically exact hierarchical equations of motion approach for the quantum electronic degrees of freedom with Langevin dynamics for the classical degrees of freedom, namely, low-frequency vibrational modes within the molecule. The approach extends previous mixed quantum–classical methods based on Langevin equations to models containing strong electron–electron or quantum electronic–vibrational interactions, while maintaining a nonperturbative and non-Markovian treatment of the molecule–metal coupling. To demonstrate the approach, nonequilibrium transport observables are calculated for a molecular nanojunction containing strong interactions.
Predicting fundamental gaps accurately from density functional theory with non-empirical local range separation
Authors: Brütting Moritz , Bahmann Hilke , Kümmel Stephan
Published: May 2024

We present an exchange–correlation approximation in which the Coulomb interaction is split into long- and short-range components and the range separation is determined by a non-empirical density functional. The functional respects important constraints, such as the homogeneous and slowly varying density limits, leads to the correct long-range potential, and eliminates one-electron self-interaction. Our approach is designed for spectroscopic purposes and closely approximates the piecewise linearity of the energy as a function of the particle number. The functional’s accuracy for predicting the fundamental gap in generalized Kohn–Sham theory is demonstrated for a large number of systems, including organic semiconductors with a notoriously difficult electronic structure.
Global well-posedness for 2D non-resistive MHD equations in half-space
Authors: Zhang Zhaoyun , Zhao Xiaopeng
Published: May 2024

This paper focuses on the initial boundary value problem of two-dimensional non-resistive MHD equations in a half space. We prove that the non-resistive MHD equations have a unique global strong solution around the equilibrium state (0, e1) for Dirichlet boundary condition of velocity and modified Neumann boundary condition of magnetic.
Extraordinary mode conversion of elastic waves through asymmetric metaplates
Authors: He Zhaojian , Tang Yun , Deng Ke
Published: May 2024

Recently, the mode conversion of elastic waves has attracted much attention, due to its scientific significance and potential applications. The applications based on the high mode conversion efficiency were also explored in many fields. However, because of the complexity of elastic waves, the existing structures for the high efficient conversion of elastic waves are relatively complicated, and there are also some limitations in the practical design. Here, we report the extraordinary mode conversion of elastic waves through asymmetric brass plates partitioned by subwavelength cuts. It is demonstrated that high efficiencies (90%) and one-way conversions between transversal waves and longitudinal waves are achieved by the structured solid plate at the resonant frequency, which leads to the striking unidirectional transmission of elastic waves. Analyzing the resonant fields demonstrates that the intrinsic modes within the individual pieces derived by the cuts are responsible for this abnormal wave conversion. The simple scheme for wave conversion presented here may have potential applications, such as non-invasive flow sensing.
Study of magnetic relaxation in MHD simulations of energetically different flares
Authors: Agarwal Satyam , Bhattacharyya Ramit
Published: May 2024

The scenario of magnetic energy dissipation in solar flares due to reconnection merits investigation from the perspective of magnetohydrodynamic (MHD) relaxation. For this purpose, we carry out data-constrained MHD simulations with the EULAG-MHD numerical model for three energetically different flares, identified as B6.4, C4.0, and M1.1 in the GOES scheme. A magnetic field reconstruction in the solar atmosphere using a non-force-free field extrapolation model identifies magnetic null points for the B6.4 and C4.0 flares and a hyperbolic flux tube for the M1.1 flare as primary reconnection sites. The simulated evolution of the magnetofluid exhibits reconnection at these sites—exemplified by the slipping reconnection in the null point topology of the B6.4 flare. An estimation of the dissipated magnetic energy using three different volumes of integration within the computational domain amounts to ≈7%, 16.8%, and 33% of the available free magnetic energy in the simulation of B6.4, C4.0, and M1.1 flares. The angle (θ) between the current density and the magnetic field at the reconnection site decreases by 75.92°, 41.37°, and 40.13°, respectively, implying more alignment. The amount of dissipated magnetic energy in the simulated dynamics of each flare is in concurrence with the general energy relation between the classes of chosen flares. Furthermore, the increase in alignment at the reconnection sites suggests the occurrence of magnetic relaxation locally.
Impact of blade shape on the aerodynamic performance and turbulent jet dynamics produced by a ducted rotor
Authors: Maldonado Victor , Fernandes Guilherme D.
Published: May 2024

A ducted rotor system was used to produce turbulent jets with a Reynolds number up to 5.97 × 105 and Mach number of 0.222 based on mean streamwise velocity. Three rotors with a diameter of 11.8 cm were manufactured and tested inside a duct with a 1 mm tip clearance at a speed up to 30 000 revolutions per minute (rpm). All rotor blades contain the same aspect ratio of 2.2, a National Advisory Committee for Aeronautics 2410 airfoil, and ideal pitch distribution. However, three different blade planform shapes were used including a rectangular shape with constant chord, trapezoidal shape with a taper ratio of 0.5, and elliptical shape where the trailing edge of the blade is expressed with an elliptical function. The rotor thrust and electric power were measured, and the thrust coefficient and figure of merit was computed. The flow-field produced by the ducted rotors was measured in the near-field using laser Doppler velocimetry techniques. The inflow velocity approximately 3 mm upstream of the rotor blade leading edge was acquired and its significance on blade aerodynamics and performance is analyzed. Time-averaged contours of cross-stream vorticity reveal intense hub and blade tip vortex structures, which are impacted by the shape of the blade, particularly in the blade tip region. Tip vorticity as well as streamwise turbulence intensity and turbulent kinetic energy in this region were mitigated for the rotors with trapezoidal and elliptical blades. However, the turbulent structure of the jet produced by all three rotor blade shapes showed similarity at a mere 2.8 rotor diameters downstream of the rotor. This finding emphasizes the importance of blade design on the near-field dynamics of ducted rotor flows for aircraft propulsion.
Diffusion, viscosity, and linear rheology of valence-limited disordered fluids
Authors: Gomez Samuel S. , Rovigatti Lorenzo
Published: May 2024

We numerically investigate the dynamics and linear rheology of disordered systems made of patchy particles, focusing on the role of valence, temperature, and bonding mechanism. We demonstrate that the dynamics is enslaved to bonding, giving rise to an activated behavior at low temperatures. By independently computing the diffusion constant and the viscosity from the simulations, we also confirm the validity of the Stokes–Einstein relation in valence-limited systems, with two caveats: (i) the diffusion constant requires a finite-size correction, at least at the intermediate density we investigate, and (ii) there is the onset of a breakdown that appears at the lowest temperatures considered. Finally, our results show that the storage and loss moduli of mixtures of divalent and M-valent particles exhibit an apparent power-law dependence on frequency, hinting at the possibility of using the composition to finely tune the rheological response of these materials. Our results compare well with literature experimental data on valence-limited DNA nanostars. In addition, the wealth of data we present and analyze here will help develop and test theoretical frameworks aimed at describing the dynamics of flexible limited-valence particles that self-assemble into disordered networks.
Current density functional framework for spin–orbit coupling: Extension to periodic systems
Authors: Franzke Yannick J. , Holzer Christof
Published: May 2024

Spin–orbit coupling induces a current density in the ground state, which consequently requires a generalization for meta-generalized gradient approximations. That is, the exchange–correlation energy has to be constructed as an explicit functional of the current density, and a generalized kinetic energy density has to be formed to satisfy theoretical constraints. Herein, we generalize our previously presented formalism of spin–orbit current density functional theory [Holzer et al., J. Chem. Phys. 157, 204102 (2022)] to non-magnetic and magnetic periodic systems of arbitrary dimension. In addition to the ground-state exchange–correlation potential, analytical derivatives such as geometry gradients and stress tensors are implemented. The importance of the current density is assessed for band gaps, lattice constants, magnetic transitions, and Rashba splittings. In the latter, the impact of the current density may be larger than the deviation between different density functional approximations.
Mitigation of disease and browsing impacts, and translocation, supports post-fire threatened flora recovery
Authors: Barrett Sarah , Yates Colin J. , Dillon Rebecca , Dilly Megan , Varcoe Ben , Martin Darcy , Castlehow Bayley , Gosper Carl R.
Published: May 2024

Context For plant species that have evolved in fire-prone environments, declines after wildfires are often driven by the combination of fire and other threatening processes. Mitigating the impacts of these threatening processes can sometimes effectively support post-fire population recovery. Aims We test the effectiveness of: (1) phosphite application to mitigate Phytophthora dieback; (2) fencing to exclude browsing by mammalian herbivores; and (3) translocation to sites where threats can be practically managed, for conservation of threatened flora affected by wildfires in 2018 and 2019 in the Stirling Range (Koi Kyeunu-ruff), south-western Australia. Methods Survival of Phytophthora-susceptible flora was compared in repeatedly sampled plots from prior to and after wildfire and ± recurrent phosphite application. Survival and growth of browsing-susceptible flora was compared post-fire in fenced and control plots. Survival, growth and flowering was compared between wild populations recruiting after wildfire and translocated populations. Key results Phosphite application increased survival of most Phytophthora-susceptible flora. Fencing led to greater growth and often increased survival. Translocated populations, with supplemental water, had greater growth rates and earlier flowering than wild populations, and a non-significant trend for higher survival. Conclusions These findings provide strong evidence supporting continuation of phosphite application, herbivore exclusion and translocation for post-fire recovery of the threatened flora of the Stirling Range. Implications With increasing wildfire extent, frequency and impact across the globe, successful management of non-fire threats will be crucial for post-fire conservation of threatened flora, with the approaches proving effective in this study likely to have conservation value elsewhere.
Severely degraded high mountain vegetation recovers under different levels of wild herbivore grazing pressure, 1991–2021
Authors: Kirkpatrick Jamie B. , Bridle Kerry L.
Published: May 2024

Context It is important to understand the way in which wild herbivore grazing affects decadal vegetation dynamics after cessation of unnatural disturbances, especially in a context of climate change. Aims We investigated the decadal effects of different grazing regimes on treeless subalpine vegetation recovery from stock grazing and burning, on sites of different environmental character and initial state. Methods At each of four sites, two fenced areas that excluded mammalian herbivores, two that allowed in only rabbits and two grazed control plots were monitored every 5 years between 1991 and 2021. General linear models were developed to explain variation in change over the 30 years in different cover types. The years in which peak and trough values occurred were also determined, as were the incidence and direction of differences between treatments in sites and years. Key results There was marked variation in change over 30 years between the sites and lifeforms. Exclusion of mammalian herbivores increased the slow rate of revegetation. There was little effect from rabbits by themselves. Unexpectedly, the cover of both short and tall herbs was not promoted by grazing exclusion. Short term climatic variation affected some cover types, with many peaks and troughs in the dry year of 2001, but it was not possible to disentangle decades scale climate change effects from the process of recovery after disturbance. Conclusions The slight increase in revegetation rates in the absence of native herbivores and rabbits does not justify culling. Restoration interventions appear to be unnecessary. The prospect of increasing fire incidence and deer numbers suggests that it is desirable to continue monitoring the plots.
A dopamine mechanism for reward maximization
Authors: Schultz Wolfram
Published: May 2024

Individual survival and evolutionary selection require biological organisms to maximize reward. Economic choice theories define the necessary and sufficient conditions, and neuronal signals of decision variables provide mechanistic explanations. Reinforcement learning (RL) formalisms use predictions, actions, and policies to maximize reward. Midbrain dopamine neurons code reward prediction errors (RPE) of subjective reward value suitable for RL. Electrical and optogenetic self-stimulation experiments demonstrate that monkeys and rodents repeat behaviors that result in dopamine excitation. Dopamine excitations reflect positive RPEs that increase reward predictions via RL; against increasing predictions, obtaining similar dopamine RPE signals again requires better rewards than before. The positive RPEs drive predictions higher again and thus advance a recursive reward-RPE-prediction iteration toward better and better rewards. Agents also avoid dopamine inhibitions that lower reward prediction via RL, which allows smaller rewards than before to elicit positive dopamine RPE signals and resume the iteration toward better rewards. In this way, dopamine RPE signals serve a causal mechanism that attracts agents via RL to the best rewards. The mechanism improves daily life and benefits evolutionary selection but may also induce restlessness and greed.
DNA lesion bypass and the stochastic dynamics of transcription-coupled repair
Authors: Nicholson Michael D. , Anderson Craig J. , Odom Duncan T. , Aitken Sarah J. , Taylor Martin S.
Published: May 2024

DNA base damage is a major source of oncogenic mutations and disruption to gene expression. The stalling of RNA polymerase II (RNAP) at sites of DNA damage and the subsequent triggering of repair processes have major roles in shaping the genome-wide distribution of mutations, clearing barriers to transcription, and minimizing the production of miscoded gene products. Despite its importance for genetic integrity, key mechanistic features of this transcription-coupled repair (TCR) process are controversial or unknown. Here, we exploited a well-powered in vivo mammalian model system to explore the mechanistic properties and parameters of TCR for alkylation damage at fine spatial resolution and with discrimination of the damaged DNA strand. For rigorous interpretation, a generalizable mathematical model of DNA damage and TCR was developed. Fitting experimental data to the model and simulation revealed that RNA polymerases frequently bypass lesions without triggering repair, indicating that small alkylation adducts are unlikely to be an efficient barrier to gene expression. Following a burst of damage, the efficiency of transcription-coupled repair gradually decays through gene bodies with implications for the occurrence and accurate inference of driver mutations in cancer. The reinitation of transcription from the repair site is not a general feature of transcription-coupled repair, and the observed data is consistent with reinitiation never taking place. Collectively, these results reveal how the directional but stochastic activity of TCR shapes the distribution of mutations following DNA damage.
Senataxin deficiency disrupts proteostasis through nucleolar ncRNA-driven protein aggregation
Authors: Wen Xuemei , Xu Hengyi , Woolley Phillip R. , Conway Olivia M. , Yao Jun , Matouschek Andreas , Lambowitz Alan M. , Paull Tanya T.
Published: May 2024

Senataxin is an evolutionarily conserved RNA-DNA helicase involved in DNA repair and transcription termination that is associated with human neurodegenerative disorders. Here, we investigated whether Senataxin loss affects protein homeostasis based on previous work showing R-loop-driven accumulation of DNA damage and protein aggregates in human cells. We find that Senataxin loss results in the accumulation of insoluble proteins, including many factors known to be prone to aggregation in neurodegenerative disorders. These aggregates are located primarily in the nucleolus and are promoted by upregulation of non-coding RNAs expressed from the intergenic spacer region of ribosomal DNA. We also map sites of R-loop accumulation in human cells lacking Senataxin and find higher RNA-DNA hybrids within the ribosomal DNA, peri-centromeric regions, and other intergenic sites but not at annotated protein-coding genes. These findings indicate that Senataxin loss affects the solubility of the proteome through the regulation of transcription-dependent lesions in the nucleus and the nucleolus.
A collective strategy to promote the dissemination of single cancer cells
Authors: Friedl Peter , Zegers Mirjam
Published: May 2024

The transition from collective to single-cell invasion in metastatic tumors has been regarded as the consequence of oncogenic drivers in concert with extracellular triggers received from the tumor microenvironment. In this issue, Yoon and colleagues (https://doi.org/10.1083/jcb.202308080) have identified an epigenetic program by which collective niches release laminin-332 and thereby cause the detachment and invasion of fully individualized tumor cells.