bluuebunny/crossref_metadata_2025 huggingface dataset:
Technique, Indications and Limitations of a Minimally Invasive
Approach to Treat Distal Radius Fractures and Malunions
Authors: Liverneaux Philippe , Amiri Laela El , Facca Sybille , Sapa Marie-Cécile
Published: January 2023

The minimally invasive flexor carpi radialis approach can be used for
volar locking plate fixation of distal radius fractures. It offers the advantage
of preserving ligamentotaxis, which facilitates the reduction and the small size
of the scar improves the esthetic result of the procedure. It is indicated for
extra-articular fractures of the distal radius. In the case of an
intra-articular fracture, an arthroscopy may be associated. In the case of a
proximal diaphyseal extension of the fracture, a second proximal approach can be
added in order to use a longer plate. Relative contraindications are comminuted
articular fractures in elderly osteoporotic patients. Functional and
radiological results are comparable to those obtained with the extented
flexor carpi radialis approach. A conversion of the procedure for a
larger incision is always possible in the case of a difficult reduction.
Efficacy and Safety of Rivaroxaban and Enoxaparin for Thromboprophylaxis Among Total Hip Arthroplasty Patients: A Systematic Review and Meta-Analysis
Authors: Wang Chong , Lan Shuhua , Xie Panpan , Yang Ruifeng
Published: January 2023

Background Venous thromboembolism (VTE) is one of the major and potentially life-threatening complications following major orthopedic surgeries. Research evidence comparing the effectiveness of rivaroxaban and enoxaparin for thromboprophylaxis specific to total hip arthroplasty (THA) has been limited. Hence, this review was done to compare the efficacy and safety of rivaroxaban against enoxaparin for thromboprophylaxis after THA.

Materials and Methods We conducted a search in databases including Medline, EMBASE, ScienceDirect, Google Scholar, and Cochrane Library from inception until May 2021. Randomized controlled trials directly comparing the effectiveness of rivaroxaban and enoxaparin for thromboprophylaxis among patients undergoing THA were eligible for inclusion. Outcome parameters assessed were efficacy in terms of total VTE and all-cause mortality, major VTE, deep vein thrombosis, symptomatic VTE, and safety in terms of major bleeding events, clinically relevant nonmajor bleeding events, minor bleeding events, total bleeding events, drug-related adverse events, and wound infection. We performed a meta-analysis with a random effects model and reported a pooled risk ratio (RR) with a 95% confidence interval (CI).

Results Eleven studies, including 9057 participants, were analyzed. Amongst efficacy outcomes, VTE and all-cause mortality pooled an RR of 0.58 (95% CI: 0.34–0.99), major VTE pooled an RR of 0.37 (95% CI: 0.15–0.90), deep vein thrombosis pooled an RR of 0.57 (95% CI: 0.32–1.02), and symptomatic VTE pooled an RR of 0.51 (95% CI: 0.30–0.87). Amongst safety outcomes, major bleeding events pooled an RR of 1.18 (95% CI: 0.77–1.80), total bleeding events pooled an RR of 1.12 (95% CI: 0.93–1.34), drug-related adverse event pooled an RR of 0.99 (95% CI: 0.87–1.12), and wound infection pooled an RR of 1.11 (95% CI: 0.58–2.14).

Conclusion Rivaroxaban is a more efficacious drug in terms of VTE and all-cause mortality compared to enoxaparin following THA, and rivaroxaban was non-inferior in terms of safety profiles such as wound infection, bleeding, and drug-related adverse events.
Gentherapien für Epilepsie: Klinische Studien sind auf dem
Weg
Authors: Müller Peter , Lerche Holger
Published: January 2023

Seit über 10 Jahren wird an Gentherapien für die schwersten
Formen von Epilepsie geforscht, die bis jetzt therapieresistent sind. Nun
ergeben sich für fokale pharmakoresistente Epilepsien und für
das Dravet Syndrom Gentherapieansätze in ersten klinischen Studien. In
diesem Artikel beschreiben wir die Funktionsweise und Ziele dieser und weiterer
Gentherapien.
Retro-[4+2]/Intramolecular Diels–Alder Cascade Allows a Concise Total Synthesis of Lucidumone
Authors: de la Torre Aurélien , Huang Guanghao , Kouklovsky Cyrille
Published: January 2023

Lucidumone is a recently isolated meroterpenoid displaying interesting biological activity. This natural product possesses a complex structure, including a bicyclo[2.2.2]octane possessing 6 contiguous stereogenic centers. Herein, we discuss strategies to solve this synthetic challenge. In particular, we developed a new method for the inverse electron-demand Diels–Alder cycloaddition between 2-pyrones and acyclic enol ethers, as a mean to obtain a ‘masked’ cyclohexadiene. This method allowed an expeditious enantioselective synthesis of (+)-lucidumone through a retro-[4+2]/intramolecular Diels–Alder reaction cascade.

1 Introduction

2 Retrosynthetic Considerations on the Bicyclo[2.2.2]octane

3 Development of a Methodology for Enantioselective IEDDA Cycloadditions

4 Enantioselective Total Synthesis of (+)-Lucidumone

5 Conclusion
Coronary Anastomosis In Stent—Useful to Do When No Other Alternative Is Given?
Authors: Balan Robert , Mogilansky Christian , Czesla Markus , Massoudy Parwis
Published: January 2023

Background Many patients being referred for coronary artery bypass grafting have a history of percutaneous coronary intervention (PCI).

Case Description In a patient after multiple PCI of the left anterior descending artery (LAD), repeated in-stent stenosis was diagnosed. The LAD being covered with stents to the periphery, no meaningful anastomosis with stent-free vessel was possible. After thorough discussion with the patient, the referring cardiologist, and our local heart team, an in-stent anastomosis was planned and created, that was found to be angiographically patent 21 months after surgery with the patient free from angina.

Conclusion Without any alternative treatment method given, our approach of in-stent anastomosis confers a good mid-term angiographic result.
Women’s online opinions are still not as influential as those of their male peers in buying decisions
Authors: Fan-Osuala Onochie
Published: January 2023

As we make progress towards gender parity in many spheres of life, an important question is whether people place as much value on women’s opinions as they do on men’s opinions, especially when making buying decisions. Using online product opinions (reviews)—an increasingly important source of information in buying decisions—as our context, we investigate whether women’s product opinions are as valuable as those of their male peers. Across three studies—one experimental and two using field data from online review platforms in the United States, we report evidence of implicit gender bias in evaluating online product opinions. In the experimental study, 216 participants (108 men, 108 women, mean age 40.6) participated in an online study where they evaluated reviews written by men and women across different product types. We find that, compared to men, women’s product opinions were rated as less helpful and were less likely to influence people’s buying decisions. For gender-typed products, that is, products highly associated with specific gender groups, men’s product opinions were rated higher than women’s in helpfulness and likelihood to influence buying decisions for male gender-typed products. However, there was no significant difference between men’s product opinions and women’s product opinions for female gender-typed products, indicating that women’s product opinions are not perceived as being more valuable than men’s opinion even for products typically associated with women. In the field data studies, we relied on the internet public’s helpfulness and usefulness votes on reviews contributed by both men and women across both search and experience goods to confirm the findings in the experimental study. We discuss some of the potential reasons and implications of our findings.
C–N-codoped Sb2Te3 chalcogenides for reducing writing current of phase-change devices
Authors: Yin You , Matsuhashi Wataru , Niiyama Koji , Yang Jie , Wang Tao , Li Jingze , Liu Yang , Yu Qi
Published: January 2023

In this work, doping C and codoping C and N into the Sb2Te3 traditional chalcogenide were investigated to reduce the writing current of the phase-change device using a chalcogenide as the active medium. No face-centered-cubic (FCC) structure was observed in the C-doped Sb2Te3 film, while it appeared after codoping C and N into Sb2Te3. The FCC crystallite size greatly reduced from 6.5 to 3.5–3.8 nm after codoping. In particular, the resistivity of FCC C–N codoped Sb2Te3 was about two orders of magnitude higher than that of Sb2Te3. The effect of the property of the chalcogenide on the writing current of the phase-change device was analyzed by the finite element method. The analysis showed that the writing current of the device using C–N-codoped Sb2Te3 as the active medium can significantly drop to about 1/8 of that of the Sb2Te3 based one.
Non-local order parameters for fermion chains via the partial transpose
Authors: Mayer L. P.
Published: January 2023

In the last two decades, a vast variety of topological phases have been described, predicted, classified, proposed, and measured. While there is a certain unity in method and philosophy, the phenomenology differs wildly. This work deals with the simplest such case: fermions in one spatial dimension, in the presence of a symmetry group G, which contains anti-unitary symmetries. A complete classification of topological phases, in this case, is available. Nevertheless, these methods are to some extent lacking as they generally do not allow to determine the class of a given system easily. This paper will take up proposals for non-local order parameters defined through anti-unitary symmetries. They are shown to be homotopy invariants on a suitable set of ground states. For matrix product states, an interpretation of these invariants is provided: in particular, for a particle–hole symmetry, the invariant determines a real division super algebra D such that the bond algebra is a matrix algebra over D.
On cluster dynamics of infinite Newtonian dynamics
Authors: Zessin Hans
Published: January 2023

On the basis of an evolution theorem for the infinite Newtonian dynamics, we give a rigorous construction of the associated cluster dynamics as a measurable flow. The latter is isomorphic to the former. This is enabled by a theorem of Mürmann.
High-performance and humidity robust multilevel lead-free all-inorganic Cs3Cu2Br5 perovskite-based memristors
Authors: Guo Zicong , Xiong Rui , Zhu Yuanyuan , Wang Ziyu , Zhou Jing , Liu Yong , Luo Daobin , Wang Youqing , Wang Hongjun
Published: January 2023

Halide perovskites have attracted surge of interest in the memristor field due to their superior electrical property and corresponding remarkable device performances. However, the issues of toxicity and unstable properties still severely restrict their potential applications. Here, the lead-free all-inorganic perovskite Cs3Cu2Br5 films are adopted as the switching layer to fabricate memristors with Al/Cs3Cu2Br5/ITO structure. The prepared Al/Cs3Cu2Br5/ITO memristors exhibit typical reproducible bipolar resistive switching (RS) behavior with striking characteristics, including ultralow operating voltages (0.45, −0.39 V), moderate high resistance state/low resistance state ratio (≈102), and remarkable retention time (>104 s). In addition, the multilevel storage capability can be achieved by controlling compliance current. The RS effect, stemming from the formation/rupture of both localized conductive Br vacancy/Al atom filaments, is proposed to illustrate the memristors. More importantly, the RS behavior of Al/Cs3Cu2Br5/ITO memristors maintains robustness in harsh environments with humidity up to 80%, enabling secure hardware applicable in extreme environments. This work demonstrates the opportunity for exploring the next-generation nonvolatile memories based on lead-free all-inorganic halide perovskites in future environmental-friendly and humidity robust electronics.
In situ x-ray absorption investigations of a heterogenized molecular catalyst and its interaction with a carbon nanotube support
Authors: Zoric Marija R. , Chan Thomas , Musgrave Charles B. , Goddard William A. , Kubiak Clifford P. , Cordones Amy A.
Published: January 2023

A highly active heterogenized molecular CO2 reduction catalyst on a conductive carbon support is investigated to identify if its improved catalytic activity can be attributed to strong electronic interactions between catalyst and support. The molecular structure and electronic character of a [Re+1(tBu-bpy)(CO)3Cl] (tBu-bpy = 4,4′-tert-butyl-2,2′-bipyridine) catalyst deposited on multiwalled carbon nanotubes are characterized using Re L3-edge x-ray absorption spectroscopy under electrochemical conditions and compared to the homogeneous catalyst. The Re oxidation state is characterized from the near-edge absorption region, while structural changes of the catalyst are assessed from the extended x-ray absorption fine structure under reducing conditions. Chloride ligand dissociation and a Re-centered reduction are both observed under applied reducing potential. The results confirm weak coupling of [Re(tBu-bpy)(CO)3Cl] with the support, since the supported catalyst exhibits the same oxidation changes as the homogeneous case. However, these results do not preclude strong interactions between a reduced catalyst intermediate and the support, preliminarily investigated here using quantum mechanical calculations. Thus, our results suggest that complicated linkage schemes and strong electronic interactions with the initial catalyst species are not required to improve the activity of heterogenized molecular catalysts.
Effects of temperature and ionic strength on the microscopic structure and dynamics of egg white gels
Authors: Begam Nafisa , Timmermann Sonja , Ragulskaya Anastasia , Girelli Anita , Senft Maximilian D. , Retzbach Sebastian , Anthuparambil Nimmi Das , Akhundzadeh Mohammad Sayed , Kowalski Marvin , Reiser Mario , Westermeier Fabian , Sprung Michael , Zhang Fajun , Gutt Christian , Schreiber Frank
Published: January 2023

We investigate the thermal gelation of egg white proteins at different temperatures with varying salt concentrations using x-ray photon correlation spectroscopy in the geometry of ultra-small angle x-ray scattering. Temperature-dependent structural investigation suggests a faster network formation with increasing temperature, and the gel adopts a more compact network, which is inconsistent with the conventional understanding of thermal aggregation. The resulting gel network shows a fractal dimension δ, ranging from 1.5 to 2.2. The values of δ display a non-monotonic behavior with increasing amount of salt. The corresponding dynamics in the q range of 0.002–0.1 nm−1 is observable after major change of the gel structure. The extracted relaxation time exhibits a two-step power law growth in dynamics as a function of waiting time. In the first regime, the dynamics is associated with structural growth, whereas the second regime is associated with the aging of the gel, which is directly linked with its compactness, as quantified by the fractal dimension. The gel dynamics is characterized by a compressed exponential relaxation with a ballistic-type of motion. The addition of salt gradually makes the early stage dynamics faster. Both gelation kinetics and microscopic dynamics show that the activation energy barrier in the system systematically decreases with increasing salt concentration.
Pressure-induced core defects and photoluminescent quenching in carbon quantum dots
Authors: Ye Tingting , Cheng Peng , Zeng Hong , Yao Deyuan , Pan Xiaomei , Xue Erqiao , Ding Junfeng
Published: January 2023

Carbon quantum dots (CDs) with favorable luminescent features for biphotonic applications have attracted much interest in modulating their photoluminescence (PL) efficiency. A surface state with various defects is believed to play a key role in the emissive intensity. Here, pressure-induced quenching of PL is observed in red emissive CDs (R-CDs) and is ascribed to defects in carbon cores upon compression. In the power-law fitting to the excitation power-dependent PL of R-CDs at high pressure, the coefficient k parameter related to the emissive mechanism decreases from 1 under ambient pressure to much less than 1 under the application of pressure, suggesting a transition from single exciton recombination to defect-related emission. With the k parameter decreasing to 0.69 at 1.6 GPa, the pressure-induced defects reduce the PL intensity by approximately one order of magnitude. Furthermore, the attenuation and broadening of the G band characterizing the sp2 hybrid structure of carbon cores in the Raman spectra for R-CDs at high pressure support that the pressure-induced lattice relaxation impairs the crystalline symmetry of the carbon core and results in the dramatic quenching of PL. Our results highlight the importance of the well-crystallized carbon core in designing CDs with high quantum yields.
Unraveling the discrepancy of temperature- and composition-dependent strain regulation in Bi0.5Na0.5TiO3 ceramics
Authors: Wu Xiaojun , Wu Chao , Wen Lanji , Yin Jie , Wu Jiagang
Published: January 2023

For Bi0.5Na0.5TiO3 (BNT)-based materials, regulating temperature and composition could both induce giant electro-strain under the critical condition. Nevertheless, only the temperature-dependent regulation method achieved low hysteresis and maintained a high strain under high ergodic condition simultaneously. Herein, we investigated the origin of this discrepancy by means of matrix with close strain level. These two regulation methods exhibited different regulation mechanisms, especially for the microscopic structure (i.e., the discrepant lattice structure and polar entities). The A-site and BO6 octahedral-dependent vibration modes exhibited obvious discrepancies under the highly ergodic condition, while the shift was relatively small around relaxor/ferroelectric crossover. Additionally, polar entities also exhibited discrepant morphology (e.g., composition-regulated one exhibited striped domains, and temperature-regulated one possessed fuzzy signals with partial nanosized domains under the critical condition) and kinetic behaviors (e.g., under highly ergodic condition, temperature-regulated polar entities rebounded slowly at the initial unloading stage). In a word, relatively small structural discrepancies leaded to similar strain performance under the critical condition, while the increasing ergodicity accompanied by increasing structural discrepancies, which finally induced different strain performance under the high ergodic condition. This insight for designing the BNT-based materials with giant electro-strain and low hysteresis was useful to accelerate the industrialization of eco-friendly actuators.
Measurement and numerical analysis of intrinsic spectral linewidths of photonic-crystal surface-emitting lasers
Authors: Inoue Takuya , Kim Taejoon , Katsuno Shumpei , Morita Ryohei , Yoshida Masahiro , De Zoysa Menaka , Ishizaki Kenji , Noda Susumu
Published: January 2023

Photonic-crystal surface-emitting lasers (PCSELs) feature high-power coherent lasing over a large area, which are potentially suitable for various applications requiring narrow spectral linewidths. In this paper, we experimentally and theoretically investigate intrinsic spectral linewidths of PCSELs. We first measure the frequency noise spectra of a fabricated PCSEL with a 250-μm lasing diameter and realize single-mode lasing with an intrinsic spectral linewidth below 70 kHz. To investigate the feasibility of narrower spectral linewidths in PCSELs, we next perform the theoretical analysis of intrinsic spectral linewidths of PCSELs by a time-dependent three-dimensional coupled-wave analysis considering carrier–photon interactions as well as thermal effects. We reveal that intrinsic spectral linewidths below 1 kHz can be obtained with a 500-μm-diameter PCSEL by reducing the cavity loss and by compensating the temperature-induced band-edge-frequency distribution.
A two-scale fractal permeability model for vuggy porous media
Authors: Huang Zhaoqin , Wang Hao , Su Xin , Liao Weiwei
Published: January 2023

A vug is a small cavity in a porous medium that is relatively larger than interparticle pore spaces. Vuggy porous media are common in carbonate petroleum reservoirs and karst aquifers. Although small, the vugs can significantly affect the porosity and permeability of a rock. The real rock cores and outcrops indicate that the cumulative size distributions of interparticle pores and vugs both follow the fractal scaling law. In this paper, a two-scale fractal permeability model for natural vuggy porous media is developed based on the fractal characteristics of interparticle pores and vugs. In the proposed model, the interparticle pores of rock matrix are described as a bundle of tortuous capillary tubes. The vugs are embedded in rock matrix and are regarded as equipotential bodies, which change the tortuosity of matrix capillary tubes. Then, different matching relations between matrix capillary tubes and vugs are conducted to predict the permeability of a vuggy porous medium. The results show that the predicted permeability varies within a certain range. The maximum permeability is the case of larger vugs matching with the larger capillary tubes, and the minimum permeability is the converse case. The most probable permeability is calculated based on a set of random matching relations by using the Monte Carlo method. The validity of the proposed model is verified by comparing with experimental results and reference data in the literature. The parameter sensitivity analysis indicates that the fractal dimension of capillary tubes and their tortuosity, and the maximum diameter of capillary tubes and vugs have significant effects on the predicted permeability.
Three-dimensional solid particle self-assembly in thermovibrational flow: The case with unidirectional temperature gradient and concurrent vibrations
Authors: Crewdson Georgie , Lappa Marcello
Published: January 2023

As a follow-up to earlier work [Crewdson and Lappa, “Spatial and temporal evolution of three-dimensional thermovibrational convection in a cubic cavity with various thermal boundary conditions,” Phys. Fluids 34, 014108 (2022)], where the main focus was on the modes of convection in a three-dimensional cubic enclosure filled with a Pr = 7 liquid undergoing vibrations in a direction “parallel” to the imposed temperature gradient, the present study considers the modes of particle clustering, which occur when solid spheres, with density ratio ξ = 1.85 or 0.3 and Stokes number (St) between 0.5 and 3.5 × 10−5, are added to the fluid. Starting from a uniform distribution of solid particles and fluid in quiescent conditions, the governing equations for the involved phases are numerically solved in their complete, time-dependent, and non-linear form for a representative vibrational Rayleigh number (8.34 × 104), angular frequency Ω = 50, and non-dimensional acceleration amplitude (γ) spanning the interval 0.4 × 107 ≤ γ ≤ 3.4 × 107. It is shown that, while for relatively high values of St and/or γ, only degenerate states are obtained, where all particles collapse on planar structures, for intermediate values of such parameters, interesting (heretofore unseen) patterns are enabled. The hallmark of these phenomena is an endless squeezing and expansion of the particle formations along the direction of the temperature gradient. As confirmed by the numerical simulations, the underlying formation mechanisms rely on the combined action of the body force acting on particles due to their different densities with respect to the host fluid and the additional drag that is produced when the carrier thermovibrational flow enters a specific stage, known as “convective burst,” where the magnitude of the fluid velocity increases dramatically.
Onset of oscillatory magnetoconvection under rapid rotation and spatially varying magnetic field
Authors: Sahoo Swarandeep , E S Sethulakshmy
Published: January 2023

The onset of periodic time-varying magnetoconvection in a regime relevant to the Earth's outer core is investigated in this study. A rapidly rotating plane fluid layer subject to an axially varying horizontal magnetic field is considered under the dynamical regimes of stronger magnetic diffusion compared to thermal and viscous diffusion rates. Dynamically specific convective instabilities, both inside and outside the tangent cylinder regions of the Earth's core, have been investigated by using appropriate patterns of the imposed mean magnetic field. The hallmark of convection onset, with such axially varying mean field, is a viscous oscillatory mode weakly modified by the magnetic field. This modified viscous oscillatory (mVO) mode is observed to exist over a wide range of the strength of the imposed field, making it a dynamically appropriate flow structure with characteristics of outer core convection. An optimal Prandtl number Pr* is found through numerical experiments where the mVO mode can be the most unstable to infinitesimal perturbations. It is further shown that this optimal state admits oscillations for earthlike regimes where thermal diffusion is much less than magnetic diffusion. Also, the formation of columnar convection rolls from isolated vortices is demonstrated as a result of combinations of the classical viscous oscillatory and mVO modes in the rapidly rotating limit (Ekman number E→0). Overall, the qualitative characteristics of magnetoconvection modes for the various imposed patterns are found to be similar despite representing distinct regions in the Earth's outer core.
Graph-based quantum response theory and shadow Born–Oppenheimer molecular dynamics
Authors: Negre Christian F. A. , Wall Michael E. , Niklasson Anders M. N.
Published: January 2023

Graph-based linear scaling electronic structure theory for quantum-mechanical molecular dynamics simulations [A. M. N. Niklasson et al., J. Chem. Phys. 144, 234101 (2016)] is adapted to the most recent shadow potential formulations of extended Lagrangian Born–Oppenheimer molecular dynamics, including fractional molecular-orbital occupation numbers [A. M. N. Niklasson, J. Chem. Phys. 152, 104103 (2020) and A. M. N. Niklasson, Eur. Phys. J. B 94, 164 (2021)], which enables stable simulations of sensitive complex chemical systems with unsteady charge solutions. The proposed formulation includes a preconditioned Krylov subspace approximation for the integration of the extended electronic degrees of freedom, which requires quantum response calculations for electronic states with fractional occupation numbers. For the response calculations, we introduce a graph-based canonical quantum perturbation theory that can be performed with the same natural parallelism and linear scaling complexity as the graph-based electronic structure calculations for the unperturbed ground state. The proposed techniques are particularly well-suited for semi-empirical electronic structure theory, and the methods are demonstrated using self-consistent charge density-functional tight-binding theory both for the acceleration of self-consistent field calculations and for quantum-mechanical molecular dynamics simulations. Graph-based techniques combined with the semi-empirical theory enable stable simulations of large, complex chemical systems, including tens-of-thousands of atoms.
Tuning nonequilibrium phase transitions with inertia
Authors: Omar Ahmad K. , Klymko Katherine , GrandPre Trevor , Geissler Phillip L. , Brady John F.
Published: January 2023

In striking contrast to equilibrium systems, inertia can profoundly alter the structure of active systems. Here, we demonstrate that driven systems can exhibit effective equilibrium-like states with increasing particle inertia, despite rigorously violating the fluctuation–dissipation theorem. Increasing inertia progressively eliminates motility-induced phase separation and restores equilibrium crystallization for active Brownian spheres. This effect appears to be general for a wide class of active systems, including those driven by deterministic time-dependent external fields, whose nonequilibrium patterns ultimately disappear with increasing inertia. The path to this effective equilibrium limit can be complex, with finite inertia sometimes acting to accentuate nonequilibrium transitions. The restoration of near equilibrium statistics can be understood through the conversion of active momentum sources to passive-like stresses. Unlike truly equilibrium systems, the effective temperature is now density dependent, the only remnant of the nonequilibrium dynamics. This density-dependent temperature can in principle introduce departures from equilibrium expectations, particularly in response to strong gradients. Our results provide additional insight into the effective temperature ansatz while revealing a mechanism to tune nonequilibrium phase transitions.
Interplay between size and softness in the vascular dynamics of microcarriers
Authors: Chien Wei , Fedosov Dmitry A. , Decuzzi Paolo
Published: January 2023

The geometry and mechanical properties of blood-borne particles play a major role in determining their vascular behavior and ability to evade immune cell sequestration. Within this context, the transport dynamics of deformable microcarriers (MCs) in a red blood cell (RBC) suspension is systematically investigated. Trajectories and the margination propensity of nominally spherical particles with five different diameters (DMC = 0.5, 1, 2, 3, and 4 μm) and three levels of deformability (stiff, soft, and extra soft) are studied for two different vessel calibers (capillary: 10 μm; arteriole: 50 μm) under three different hematocrits (Hct = 10%, 20%, and 30%). The multi-component suspension is modeled as elastic membranes and elastic solids representing RBC and MC, respectively, immersed in Newtonian fluid simulated by smoothed particle hydrodynamics method. The results document the existence of two regimes: (i) a “collision force” regime where fast-moving RBCs push sufficiently small particles toward the wall; (ii) a “lift force” regime where sufficiently large particles migrate away from the wall. Between these two regimes, a maximum in margination propensity appears, which depends on the particle size, deformability, and flow conditions. For the considered vessel calibers and hematocrits, 2 μm MC offers the highest margination propensity. The vascular dynamics of small MC (DMC ≤ 0.5 μm) is hardly influenced by their deformability, whereas extra soft MCs behave similarly to RBCs. In addition to the limitations related to the two-dimensional analysis, these simulations suggest that moderately deformable micrometric carriers would more efficiently marginate and seek for vascular targets in the microcirculation.
Sum-frequency vibrational spectroscopy of centrosymmetric molecule at interfaces
Authors: Zheng Ren-Hui , Wei Wen-Mei , Zhang Shuo-Cang
Published: January 2023

The centrosymmetric benzene molecule has zero first-order electric dipole hyperpolarizability, which results in no sum-frequency vibrational spectroscopy (SFVS) signal at interfaces, but it shows very strong SFVS experimentally. We perform a theoretical study on its SFVS, which is in good agreement with the experimental results. Its strong SFVS mainly comes from the interfacial electric quadrupole hyperpolarizability rather than the symmetry-breaking electric dipole, bulk electric quadrupole, and interfacial and bulk magnetic dipole hyperpolarizabilities, which provides a novel and completely unconventional point of view.
The hierarchy of Davydov’s Ansätze: From guesswork to numerically “exact” many-body wave functions
Authors: Zhao Yang
Published: January 2023

This Perspective presents an overview of the development of the hierarchy of Davydov’s Ansätze and a few of their applications in many-body problems in computational chemical physics. Davydov’s solitons originated in the investigation of vibrational energy transport in proteins in the 1970s. Momentum-space projection of these solitary waves turned up to be accurate variational ground-state wave functions for the extended Holstein molecular crystal model, lending unambiguous evidence to the absence of formal quantum phase transitions in Holstein systems. The multiple Davydov Ansätze have been proposed, with increasing Ansatz multiplicity, as incremental improvements of their single-Ansatz parents. For a given Hamiltonian, the time-dependent variational formalism is utilized to extract accurate dynamic and spectroscopic properties using Davydov’s Ansätze as its trial states. A quantity proven to disappear for large multiplicities, the Ansatz relative deviation is introduced to quantify how closely the Schrödinger equation is obeyed. Three finite-temperature extensions to the time-dependent variation scheme are elaborated, i.e., the Monte Carlo importance sampling, the method of thermofield dynamics, and the method of displaced number states. To demonstrate the versatility of the methodology, this Perspective provides applications of Davydov’s Ansätze to the generalized Holstein Hamiltonian, variants of the spin-boson model, and systems of cavity-assisted singlet fission, where accurate dynamic and spectroscopic properties of the many-body systems are given by the Davydov trial states.
Modified magnetism in heterostructures of Cr2Ge2Te6 and oxides
Authors: Llacsahuanga Allcca A. E. , Idzuchi H. , Pan X. C. , Tanigaki K. , Chen Y. P.
Published: January 2023

We study the effects of interfacing the van der Waals ferromagnet Cr2Ge2Te6 with oxide layers, such as NiO and MgO, in a few different configurations. For this, the magnetic hysteresis curves, obtained by magneto optical Kerr effect, of Cr2Ge2Te6 flakes of similar thicknesses were evaluated. Compared to the properties of a bare Cr2Ge2Te6, we observed an increased perpendicular magnetic anisotropy and enhanced Curie temperature in the Cr2Ge2Te6/NiO heterostructure. In contrast, we report little or no change of the magnetic properties in a Cr2Ge2Te6/NiO and Cr2Ge2Te6/MgO where the Cr2Ge2Te6 was exfoliated on top of the oxide layer. Finally, strain is considered as the mechanism of the enhancement, as we observed the formation of wrinkles in thin Cr2Ge2Te6/NiO heterostructure and the Raman characteristics close to the wrinkles indicated a tensile strain, which is consistent with stronger ferromagnetism in Cr2Ge2Te6.
Classification and characterization of coexisting defects from magnetic flux leakage data using deep learning method
Authors: Piao Guanyu , Ling Jiatong , Li Jiaoyang
Published: January 2023

Ferromagnetic materials are widely used in infrastructure, such as steam generators, storage tanks, and gas pipelines. During their service time, ferromagnetic materials are subject to deterioration and defects are prone to generate which could damage infrastructures and cause catastrophic accidents. Magnetic flux leakage (MFL) is one of the widely used nondestructive evaluation (NDE) methods to detect and characterize defects in ferromagnetic materials to ensure infrastructure safety. However, many research works have been carried out on the modeling, classification, and characterization of a single defect, while the scenario of coexisting defects is ignored. In practical field, the coexistence of surface and subsurface defects within an overlapping area can cause much earlier than expected deterioration or even penetration, the result of which is more damaging. Here, we propose a convolutional neural network (CNN) based deep learning method to differentiate between single defect and coexisting defects scenarios and estimate the defect sizes including length, width, and depth. Finite-element-method (FEM) simulation models are developed to investigate the effect of coexisting defects on the measured MFL data. The models with different defect parameters are calculated to generate 354 MFL data for the training and testing of deep learning method. The experimental results show that the classification accuracy of deep learning method is over 94% and higher than the traditional machine learning methods, and the defect size estimation errors are within 0.97 mm, 0.59 mm, and 3.67% of wall thickness, respectively, which are validated to be a good classification and characterization tool for the coexisting defects scenario.
Multi-directional extremely-low-frequency electromagnetic ocean wave energy harvester based on improved double pendulum structure
Authors: Li Yuquan , Qiu Jing , Lan Tian , Song Hongrui
Published: January 2023

The study of ocean wave energy harvesting technology is of great importance in the field of distributed sensor energy supply. Aiming at the problems of insufficient output power, single direction of collecting vibration, restricted working frequency band and complex structure of traditional ocean wave energy harvesters of marine network nodes, a multi-directional extremely-low-frequency electromagnetic ocean wave energy harvester based on improved double pendulum structure is designed. The effect of different component parameters of the energy harvester on the output electrical performance is analyzed by simulation software and a constructed vibration test rig, and the relationship between output voltage and motion state is explored. After optimizing the structure, the ocean wave energy harvester has a minimum response frequency of about 0.25 Hz at a vertical wave height of 0.6 m and a minimum response flow speed of about 0.3 m/s in the horizontal direction. The peak output power is about 150 mW when the wave height is 0.6 m at a frequency of 1 Hz and about 110 mW when the horizontal speed is 0.9 m/s. Experimental results show that the energy harvester can better capture ocean wave energy and provide power for night lights and even IoT devices.
A review of factors affecting the welfare of weaned replacement heifers in pasture-based dairy production systems
Authors: Verdon Megan
Published: January 2023

The pasture-based replacement dairy heifer is typically housed and managed intensively from birth until weaning, but post-weaning is housed outdoors in paddocks under less intensive management. Little is published about the welfare of the weaned dairy heifer in pasture-based systems. The aim of this review is to consolidate the scientific literature and provide an overview of factors affecting the welfare of weaned heifers on pastoral dairies. Heifer welfare during transition to the milking herd can be optimised through calving support and by pre-exposing heifers to some of the stressful conditions associated with the milking herd. For the former, heifers should be well grown at calving (≥85% mature bodyweight) and could be mated to bulls that will produce a smaller calf (e.g. Jersey bulls, sexed semen to produce a female calf). Sires should be selected for high ease of calving predicted transmitting ability, and farms should develop and implement a calving intervention and assistance policy. Mixing heifers with milking cows prior to calving, exposing them to competitive grazing conditions and training them to the milking parlour may reduce overall stress burden and enhance adaptability, but research is needed to quantify the welfare and productive merit of this sort of program in seasonal pasture-based dairy systems. This review highlights a lack of recent data relating to the management of the replacement heifer between weaning and their first calving. Research needs to document and disseminate modern dairy heifer management practices in pasture-based systems, as these will affect heifer welfare. The following data need to be collected as a priority: (1) frequency that heifers are weighed or receive health assessments, (2) heifer grazing management, (3) frequency and age of surgical removal of supernumerary teats, (4) mortality rate from weaning until the first lactation, and (5) typical procedures to transition heifers to the milking herd, including management of the first calving. There is also a need to document the management and housing conditions of exported dairy heifers living in other countries.
Urban billabong restoration benefits from Traditional Owner involvement and regular flooding
Authors: Greet Joe , Lankri Rephael , Gaskill Sarah , Fischer Sarah , Freedman Delta Lucille , Preston Tiana
Published: January 2023

Context Floodplain wetlands (e.g. billabongs) in urban environments have significant ecological and cultural value, yet are often highly degraded. Impacts such as reduced flooding and weed invasion continue to threaten these critical ecosystems. Both ecological and Indigenous people’s knowledge are important for urban billabong restoration. Aims Our project aimed to (1) assess the response of billabong vegetation to flooding, and (2) increase the role of local Traditional Owners in billabong management. Methods Over 3 years, a team of wetland ecologists and local Wurundjeri Woi Wurrung Narrap (‘Country’) Rangers surveyed responses of understorey vegetation and the condition and flowering of remnant river red gums (Eucalyptus camaldulensis) to flooding across seven degraded billabongs adjacent to the Birrarung (Yarra River) in Melbourne, Australia. Knowledge sharing during ‘On Country’ days guided restoration targets and management direction. Key results Regular (at least 2 in 3 years) and longer-duration (up to 8 months) flooding promoted native wetland plants, supressed weeds, and improved the condition and reproductive output of river red gums. Monitoring by Indigenous Rangers facilitated the cultural practice of caring for Country. Conclusions Regular flooding and Traditional Owner involvement promotes billabong health. Implications Collaborative research and knowledge sharing with Traditional Owners advances wetland restoration practice and improves care of Country.
Reflections of Australian general practitioners during the first year of the COVID-19 pandemic: a qualitative study
Authors: Ovington Seren , Anderson Katrina , Choy Melinda , Haesler Emily
Published: January 2023

Background General practitioners (GPs) have played an integral role in Australia’s coronavirus disease 2019 (COVID-19) pandemic response. However, little is known about how GPs themselves have been impacted by the COVID-19 pandemic. This study aimed to increase our understanding of the experiences of GPs working during the COVID-19 pandemic. Methods A qualitative study was conducted using semi-structured interviews. Using purposive sampling, 15 GPs from South-Eastern Australia were asked to reflect on their experiences during the first year of the COVID-19 pandemic. Interview transcripts underwent thematic analysis. Results Five main themes were identified: fear of infection; uncertainty and information overload; impacts on the government–GP relationship; impacts on the patient–doctor relationship; and teamwork within practices and among GPs. Conclusions The 15 GPs interviewed in this study provided valuable insights into their experiences working during the first year of the COVID-19 pandemic. From these insights, four recommendations propose what could be done to help support GPs to respond to a pandemic while continuing to deliver primary health care.
Data-driven predictions of the time remaining until critical global warming thresholds are reached
Authors: Diffenbaugh Noah S. , Barnes Elizabeth A.
Published: January 2023

Leveraging artificial neural networks (ANNs) trained on climate model output, we use the spatial pattern of historical temperature observations to predict the time until critical global warming thresholds are reached. Although no observations are used during the training, validation, or testing, the ANNs accurately predict the timing of historical global warming from maps of historical annual temperature. The central estimate for the 1.5 °C global warming threshold is between 2033 and 2035, including a ±1σ range of 2028 to 2039 in the Intermediate (SSP2-4.5) climate forcing scenario, consistent with previous assessments. However, our data-driven approach also suggests a substantial probability of exceeding the 2 °C threshold even in the Low (SSP1-2.6) climate forcing scenario. While there are limitations to our approach, our results suggest a higher likelihood of reaching 2 °C in the Low scenario than indicated in some previous assessments—though the possibility that 2 °C could be avoided is not ruled out. Explainable AI methods reveal that the ANNs focus on particular geographic regions to predict the time until the global threshold is reached. Our framework provides a unique, data-driven approach for quantifying the signal of climate change in historical observations and for constraining the uncertainty in climate model projections. Given the substantial existing evidence of accelerating risks to natural and human systems at 1.5 °C and 2 °C, our results provide further evidence for high-impact climate change over the next three decades.
Distributed algorithms from arboreal ants for the shortest path problem
Authors: Garg Shivam , Shiragur Kirankumar , Gordon Deborah M. , Charikar Moses
Published: January 2023

Colonies of the arboreal turtle ant create networks of trails that link nests and food sources on the graph formed by branches and vines in the canopy of the tropical forest. Ants put down a volatile pheromone on the edges as they traverse them. At each vertex, the next edge to traverse is chosen using a decision rule based on the current pheromone level. There is a bidirectional flow of ants around the network. In a previous field study, it was observed that the trail networks approximately minimize the number of vertices, thus solving a variant of the popular shortest path problem without any central control and with minimal computational resources. We propose a biologically plausible model, based on a variant of the reinforced random walk on a graph, which explains this observation and suggests surprising algorithms for the shortest path problem and its variants. Through simulations and analysis, we show that when the rate of flow of ants does not change, the dynamics converges to the path with the minimum number of vertices, as observed in the field. The dynamics converges to the shortest path when the rate of flow increases with time, so the colony can solve the shortest path problem merely by increasing the flow rate. We also show that to guarantee convergence to the shortest path, bidirectional flow and a decision rule dividing the flow in proportion to the pheromone level are necessary, but convergence to approximately short paths is possible with other decision rules.
Curvature sensing as an emergent property of multiscale assembly of septins
Authors: Shi Wenzheng , Cannon Kevin S. , Curtis Brandy N. , Edelmaier Christopher , Gladfelter Amy S. , Nazockdast Ehssan
Published: January 2023

The ability of cells to sense and communicate their shape is central to many of their functions. Much is known about how cells generate complex shapes, yet how they sense and respond to geometric cues remains poorly understood. Septins are GTP-binding proteins that localize to sites of micrometer-scale membrane curvature. Assembly of septins is a multistep and multiscale process, but it is unknown how these discrete steps lead to curvature sensing. Here, we experimentally examine the time-dependent binding of septins at different curvatures and septin bulk concentrations. These experiments unexpectedly indicated that septins’ curvature preference is not absolute but rather is sensitive to the combinations of membrane curvatures present in a reaction, suggesting that there is competition between different curvatures for septin binding. To understand the physical underpinning of this result, we developed a kinetic model that connects septins’ self-assembly and curvature-sensing properties. Our experimental and modeling results are consistent with curvature-sensitive assembly being driven by cooperative associations of septin oligomers in solution with the bound septins. When combined, the work indicates that septin curvature sensing is an emergent property of the multistep, multiscale assembly of membrane-bound septins. As a result, curvature preference is not absolute and can be modulated by changing the physicochemical and geometric parameters involved in septin assembly, including bulk concentration, and the available membrane curvatures. While much geometry-sensitive assembly in biology is thought to be guided by intrinsic material properties of molecules, this is an important example of how curvature sensing can arise from multiscale assembly of polymers.