bluuebunny/crossref_metadata_2025 huggingface dataset:
Small-scale loops heated to transition region temperatures and their chromospheric signatures in the simulated solar atmosphere
Authors: Skan M. , Danilovic S. , Leenaarts J. , Calvo F. , Rempel M.
Published: February 2023

Context.Recent observations have revealed loop-like structures at very small scales visible in observables that sample the transition region (TR) and even coronal temperatures. These structures are referred to as either ‘unresolved fine structures’, ‘dynamic cool loops’, ‘miniature hot loops’ or ‘campfires’ depending on the observables in which they are detected. Their formation remains unclear.

Aims.Realistic magnetohydrodynamic simulations and forward synthesis of spectral lines are used to investigate how these features occur.

Methods.Computations were carried out using the MURaM code to generate model atmospheres. The synthetic Hαand Si IV spectra are calculated at two angles (μ = 1,μ = 0.66) using the Multi3D code. We traced magnetic field lines in the model and examined the evolution of the underlying field topology.

Results.The synthetic HαDopplergrams reveal loops that evolve dramatically within a few minutes. The synthetic Hαline profiles show observed asymmetries and Doppler shifts in the line core. However, they also show strong emission peaks in the line wings, even at the slanted view. The synthetic Si IV emission features partly coincide with structures visible in HαDopplergrams and partly follow separate magnetic field threads. Some are even visible in the emission measure maps for the lg(T/K) = [5.8, 6.2] temperature interval. The emission areas trace out the magnetic field lines rooted in opposite polarities in a bipolar region.

Conclusions.The model shows that a loop-like structure in a bipolar system with footpoints undergoing rapid movement and shuffling can produce many small-scale recurrent events heated to high temperatures. It demonstrates that heating to different temperatures occurs and can be confined to a small part of the loop, at the location where resistive and viscous heating increases. The model largely reproduces the observed features in terms of size, lifetime and morphology in chromospheric, TR and coronal observables. The morphology and evolution of the resulting observable features can vary depending on the viewing angle.
Universal gravity-driven isothermal turbulence cascade in disk galaxies
Authors: Fensch Jérémy , Bournaud Frédéric , Brucy Noé , Dubois Yohan , Hennebelle Patrick , Rosdahl Joakim
Published: February 2023

While interstellar gas is known to be supersonically turbulent, the injection processes of this turbulence are still unclear. Many studies suggest a dominant role of gravitational instabilities. However, their effect on galaxy morphology and large-scale dynamics varies across cosmic times, in particular, due to the evolution of the gas fraction of galaxies. In this paper, we propose numerical simulations to follow the isothermal turbulent cascade of purely gravitationally driven turbulence from its injection scale down to 0.095 pc for a gas-poor spiral disk and a gas-rich clumpy disk. For this purpose, and to lift the memory-footprint technical lock of sufficiently resolving the interstellar medium of a galaxy, we developed an encapsulated zoom method that allows us to self-consistently probe the self-generated turbulence cascade over three orders of magnitude on spatial scales. We followed this cascade for 10 Myr. We find that the turbulent cascade follows the same scaling laws in both setups. Namely, in both cases, the turbulence is close to equipartition between its compressive and solenoidal modes, the velocity power spectrum follows the Burgers scaling, and the density power spectrum is rather shallow, with a power-law slope of −0.7. Last, gravitationally bound substructures follow a mass distribution with a −1.8 slope, similar to that of CO clumps. These simulations thus suggest that gravity-driven isothermal turbulent cascades are universal in disk galaxies across cosmic time.
3D-Printed silicone anatomic patient simulator to enhance training on cardiopulmonary bypass
Authors: Messarra Branden Tyler , Wang Yaxin , Smith P. Alex , Peak Preston , Adams Deborah L. , Crane Terry N.
Published: February 2023

Background: Simulator training is important for teaching perfusion students fundamental skills associated with CBP before they start working in the clinic. Currently available high-fidelity simulators lack anatomic features that would help students visually understand the connection between hemodynamic parameters and anatomic structure. Therefore, a 3D-printed silicone cardiovascular system was developed at our institution. This study aimed to determine whether using this anatomic perfusion simulator instead of a traditional “bucket” simulator would better improve perfusion students’ understanding of cannulation sites, blood flow, and anatomy.Methods: Sixteen students were tested to establish their baseline knowledge. They were randomly divided into two groups to witness a simulated bypass pump run on one of two simulators – anatomic or bucket – then retested. To better analyze the data, we defined “true learning” as characterized by an incorrect answer on the pre-simulation assessment being corrected on the post-simulation assessment.Results: The group that witnessed the simulated pump run on the anatomic simulator showed a larger increase in mean test score, more instances of true learning, and a larger gain in the acuity confidence interval.Conclusions: Despite the small sample size, the results suggest that the anatomic simulator is a valuable instrument for teaching new perfusion students.
Pulmonale Hypertonie bei Lungenerkrankungen
Authors: Biener Leonie , Pizarro Carmen , Skowasch Dirk
Published: February 2023

Die pulmonale Hypertonie (PH) ist eine häufige Komorbidität von Lungenerkrankungen wie der chronisch obstruktiven Lungenerkrankung oder der idiopathischen pulmonalen Fibrose und geht mit
einer erhöhten Letalität einher. Die pulmonalarterielle Hypertonie (PAH) ist hingegen eine seltene Erkrankung, ebenfalls mit hoher Letalität. Durch das häufig ältere und komorbide
Patientengut der PAH ergeben sich Subgruppen, die sich hinsichtlich ihres Therapieansprechens und der Letalität von typischen PAH-Patienten unterscheiden. In den letzten Jahren hat sich
gezeigt, dass sich neben dem kardialen bzw. Linksherzphänotyp auch ein pulmonaler bzw. kardiopulmonaler Phänotyp abgrenzen lässt. Die Differenzierung zu einer schwergradigen PH bei
Lungengrunderkrankung kann schwierig sein und ist aufgrund der unterschiedlichen Therapiestrategien Expertenzentren vorbehalten.
Evaluation of Scapholunate Injury and Repair with Dynamic (4D) CT: A Preliminary Report of Two Cases
Authors: Trentadue Taylor P. , Lopez Cesar , Breighner Ryan E. , Fautsch Kalli , Leng Shuai , Holmes III David R. , Moran Steven L. , Thoreson Andrew R. , Kakar Sanjeev , Zhao Kristin D.
Published: February 2023

Background In predynamic or dynamic scapholunate (SL) instability, standard diagnostic imaging may not identify SL interosseous ligament (SLIL) injury, leading to delayed detection and intervention. This study describes the use of four-dimensional computed tomography (4DCT) in identifying early SLIL injury and following injured wrists to 1-year postoperatively.

Description of Technique 4DCT acquires a series of three-dimensional volume data with high temporal resolution (66 ms). 4DCT-derived arthrokinematic data can be used as biomarkers of ligament integrity.

Patients and Methods This study presents the use of 4DCT in a two-participant case series to assess changes in arthrokinematics following unilateral SLIL injury preoperatively and 1-year postoperatively. Patients were treated with volar ligament repair with volar capsulodesis and arthroscopic dorsal capsulodesis. Arthrokinematics were compared between uninjured, preoperative injured, and postoperative injured (repaired) wrists.

Results 4DCT detected changes in interosseous distances during flexion-extension and radioulnar deviation. Generally, radioscaphoid joint distances were greatest in the uninjured wrist during flexion-extension and radioulnar deviation, and SL interval distances were smallest in the uninjured wrist during flexion-extension and radioulnar deviation.

Conclusion 4DCT provides insight into carpal arthrokinematics during motion. Distances between the radioscaphoid joint and SL interval can be displayed as proximity maps or as simplified descriptive statistics to facilitate comparisons between wrists and time points. These data offer insight into areas of concern for decreased interosseous distance and increased intercarpal diastasis. This method may allow surgeons to assess whether (1) injury can be visualized during motion, (2) surgery repaired the injury, and (3) surgery restored normal carpal motion.

Level of Evidence Level IV, Case series.
Chemoprophylaxis and Management of Venous Thromboembolism in Microvascular Surgery
Authors: Mirzamohammadi Fatemeh , Nnamani Silva Ogonna N. , Leaf Rebecca K. , Eberlin Kyle R. , Valerio Ian L.
Published: February 2023

This review aims to highlight the common pharmacological and nonpharmacological interventions utilized for thromboprophylaxis as well as flap salvage in microsurgery. A literature review was conducted in PubMed/National Center for Biotechnology Information, Scopus, Web of Science, and MEDLINE databases. Articles with a focus on thromboprophylaxis in microsurgical procedures spanning head and neck surgery, breast and extremity microvascular reconstruction, deep venous thrombosis/pulmonary embolus in microvascular surgery, and flap thrombosis and salvage were included in this review. The majority of available evidence supports mechanical venous thromboembolism (VTE) prophylaxis in all patients undergoing microsurgery given the presence of multiple risk factors for VTE within this particular patient population. Based on the literature review, addition of VTE chemoprophylactic agents is beneficial and an algorithmic approach to thromboprophylaxis in microsurgery patients and management of patients with thrombosis based on literature review and senior authors' experience is recommended and outlined.
A Stepwise Intraoperative Protocol to Minimize Complications after Volar Plating
Authors: Goorens Chul Ki , Eetvelde Gilles Van , Debaenst Niels , Royen Kjell Van
Published: February 2023

Background Although outcome of volar plating is generally good, care should be taken to avoid specific iatrogenic and preventable complications, with an incidence reporting averaging 15%. Flexor tendon rupture due to a prominent plate, extensor tendon rupture due to a dorsal protruding screw tips, cartilage lesions due to intra-articular screw placement, loss of reduction due to insufficient stability, and persisting ulnar pain with distal radioulnar joint instability due to unstable triangular fibrocartilaginous complex lesions or unstable ulnar styloid base fractures all have been described.

Purpose We believe that a majority of these complications can be prevented by meticulous assessment of several intraoperative parameters during volar plating. Therefore, we introduce the WRIST protocol, a stepwise easy-to-remember manual that combines multiple fluoroscopic measurements to guide intraoperative decision making.

Conclusion Large prospective studies of the “WRIST” protocol are needed for validation. But we believe that it may help surgeons to optimize surgical technique, functional and radiographic outcome, and prevent complications when treating distal radial fractures.
Weather extremes, agriculture and the value of weather index insurance
Authors: Hott Christian , Regner Judith
Published: February 2023

This paper evaluates the potential value of a weather index insurance for the agriculture sector in an high income country (Germany). In our theoretical analysis we model an index insurance, a loss-based insurance market as well as a combination of both kinds of insurance and compare the resulting expected utility of a risk averse crop farmer. To find a suitable index, we conduct a panel estimation and evaluate the link between different weather variables and losses of crop farmers in Germany. Following our estimation, mean temperatures in summer have the highest potential for an valuable index insurance. Finally, we simulate the theoretical model using the results from the estimation and using different thresholds for the definition of a NatCat. According to this simulation, index-insurance is more attractive for the lower and more frequently occurring losses and loss-based insurance is more attractive for rare high losses. A combination of both kinds of insurance could be optimal for intermediate cases.
Development of a laser-based angle-resolved-photoemission spectrometer with sub-micrometer spatial resolution and high-efficiency spin detection
Authors: Xu R. Z. , Gu X. , Zhao W. X. , Zhou J. S. , Zhang Q. Q. , Du X. , Li Y. D. , Mao Y. H. , Zhao D. , Huang K. , Zhang C. F. , Wang F. , Liu Z. K. , Chen Y. L. , Yang L. X.
Published: February 2023

Angle-resolved photoemission spectroscopy with sub-micrometer spatial resolution (μ-ARPES), has become a powerful tool for studying quantum materials. To achieve sub-micrometer or even nanometer-scale spatial resolution, it is important to focus the incident light beam (usually from synchrotron radiation) using x-ray optics, such as the zone plate or ellipsoidal capillary mirrors. Recently, we developed a laser-based μ-ARPES with spin-resolution (LMS-ARPES). The 177 nm laser beam is achieved by frequency-doubling a 355 nm beam using a KBBF crystal and subsequently focused using an optical lens with a focal length of about 16 mm. By characterizing the focused spot size using different methods and performing spatial-scanning photoemission measurement, we confirm the sub-micron spatial resolution of the system. Compared with the μ-ARPES facilities based on the synchrotron radiation, our LMS-ARPES system is not only more economical and convenient, but also with higher photon flux (>5 × 1013 photons/s), thus enabling the high-resolution and high-statistics measurements. Moreover, the system is equipped with a two-dimensional spin detector based on exchange scattering at a surface-passivated iron film grown on a W(100) substrate. We investigate the spin structure of the prototype topological insulator Bi2Se3 and reveal a high spin-polarization rate, confirming its spin-momentum locking property. This lab-based LMS-ARPES will be a powerful research tool for studying the local fine electronic structures of different condensed matter systems, including topological quantum materials, mesoscopic materials and structures, and phase-separated materials.
Multi-scale analysis of solute dispersion in non-Newtonian flows in a tube with wall absorption
Authors: A Aruna , Barik Swarup
Published: February 2023

This study presents the two-dimensional concentration distribution of a solute cloud for non-Newtonian fluid in a tube flow with wall absorption. The non-Newtonian fluid models, such as the Carreau–Yasuda and Carreau fluid models, are helpful in investigating solute dispersion in the bloodstream and have also been effective in understanding hemodynamics. The multi-scale method of homogenization is used here to analyze the dispersion of solute through a straight tube for Carreau–Yasuda and Carreau fluids, which represents the shear-thinning nature. Most of the previous studies are mainly focused on determining the dispersion coefficient and mean concentration distribution for non-Newtonian fluids. Apart from those in our study, we also derived analytical expressions for the two-dimensional concentration distribution for Carreau–Yasuda and Carreau fluids. As the exact peak position of the two-dimensional concentration is a concern in real-life applications rather than that of mean concentration, the effects of wall absorption parameter (α*), the Weissenberg number (We), Yasuda parameter (a), and power-law index (n) on solute concentration distribution are discussed. Comparison between the present results and previous results of solute dispersion for non-Newtonian as well as Newtonian fluids are also enclosed in this study. Results reveal that the mean concentration decreases with increasing values of We because of an increase in the dispersion coefficient. Carreau–Yasuda and Carreau fluids act like Newtonian fluid for very small values of We. At the initial stage, the solute concentration exhibits transverse non-uniformity and then becomes uniform over a larger timescale. The effects of non-Newtonian parameters such as We, a, and n on transverse variation are also studied. It is noted that parameters n, We, and a have no significant impacts on the non-uniformity of the transverse concentration variation on both sides of the tube centroid, but that is not the case for the wall absorption parameter. It is observed that wall absorption results in significant transverse concentration non-uniformity across the tube cross section even after large times.
Theoretical study of phonon and electron transport in low band gap Janus MXene monolayer MoWCO2 for thermoelectric application
Authors: Rana Gourav , Gupta Raveena , Bera Chandan
Published: February 2023

A theoretical study is performed on narrow bandgap Janus monolayer MoWCO2 using the density functional theory and the Boltzmann transport equation. The scattering rate is calculated for electron–phonon, phonon–phonon, phonon-boundary, and electron-boundary scattering. It has a power factor (6.5 × 103 μW/mK2) for p-type and (1.5 × 103 μW/mK2) for n-type at T = 700 K. A strong effect of surface scattering is observed in phonon transport, and lattice thermal conductivity is reduced to 65 W/m K from 308 W/m K at T = 300K for 1 μm width (L) of ribbon. In contrast, there is no change observed in electrical conductivity. This reduction in thermal conductivity improves the thermoelectric figure of merit to 0.33 (p-type) and 0.08 (n-type) at T = 700 K for L = 10 nm from 0.04 (p-type) and 0.01 (n-type). The obtained Young's modulus and Poisson's ratio are 244 N/m and 0.55, respectively, indicating that the material can be deformed under small strain. The obtained in-plane piezoelectric coefficients are e11 = 268 pC/m and d11 = 1.6 pm/V. This indicates the material will be suitable for wearable thermoelectric devices and sensor applications.
Flow behavior analysis in boundary layer transition based on the Liutex–shear decomposition
Authors: Pang Biyu , Ding Yuan , Wang Yiqian
Published: February 2023

The Liutex based vortex identification method is superior to previous methods in that it overcomes the issues of threshold problem, shear contamination, etc., with a clear physical meaning that the direction of the Liutex vector represents the local axis of rotation, while the magnitude is equal to twice the angular velocity of the rigid-rotation part of the flow. The current study focuses on the interaction between the Liutex represented rotation and the residual shear part during the development of Λ vortex and hairpin vortex in boundary layer transition. The temporal–spatial evolution and development of typical vortical structures are analyzed based on the Liutex–shear decomposition with particular attention paid to the position and strength changes of Liutex and shear. Vortex core lines are extracted to investigate the mutual interactions between rotation and shear inside vortices. It is demonstrated that for the Λ vortex, spanwise rotating motions are formed at the head region and can persist for a long time under the influence of surrounding shear, while the tail region of the Λ vortex stretches down near the wall but then becomes weaker due to dissipation. High-shear regions tend to be located on top or below the vortices. When the shear layer formed between the legs gets stronger, it will be rolled up to form new vortices. On the one hand, the vortex legs together with the newly formed spanwise vortex consist of a new hairpin vortex, which, in turn, leads to the generation of the second- and third-level hairpin vortices. On the other hand, it also generates many smaller streamwise vortices in the near wall region. The results show that the interaction between Liutex and shear is very important in the development of vortical structures during transition.
Optimum contact resistance for two-terminal magnetoresistance in a lateral spin valve
Authors: Spiesser A. , Jansen R. , Saito H. , Yuasa S.
Published: February 2023

The two-terminal magnetoresistance (2T-MR) due to spin accumulation in a lateral spin valve is determined for devices with a Si channel and Fe/MgO tunnel contacts of varying MgO thickness. Established theory predicts that the 2T-MR exhibits a pronounced maximum for contact resistances comparable to the spin resistance rs of the channel. At large contact resistance (≫rs), the 2T-MR is, indeed, very small, despite the large tunnel spin polarization (TSP) of the contacts (90%). When the contact resistance is reduced toward rs, the 2T-MR increases, but much less than expected because for thinner MgO the TSP decays. For devices with the thinnest MgO and contact resistances near the predicted optimum, the 2T-MR is actually lower, owing to the smaller TSP (14%). The optimum and scaling of the 2T-MR are, thus, profoundly affected by the variation of the TSP with contact resistance. This is relevant for the design of practical two-terminal devices, including those with channel materials other than Si.
Electro-osmotic flow of generalized Maxwell fluids in triangular microchannels based on distributed order time fractional constitutive model
Authors: Cao Limei , Li Cong , Li Botong , Si Xinhui , Zhu Jing
Published: February 2023

Based on the linearized Poisson–Boltzmann equation, the electro-osmotic flow of a generalized Maxwell fluid under an alternating field in an isosceles right triangle microchannel is studied. The finite volume method and L2 interpolation method are used to obtain the numerical solution. An analytical solution is constructed to verify the accuracy of the numerical solution. Under the alternating current, the velocity will oscillate periodically. The velocity amplitude of the Maxwell fluid with the distributed order time fractional derivative is larger than that of Newtonian fluids and fractional Maxwell fluids, which indicates that its elastic characteristics further promote fluid flow. However, oscillation of the velocity does not achieve synchronization with the oscillation of the electric fields. Furthermore, due to the existence of the angle effect, the velocity will develop at acute angles and form a larger value of velocity first. The numerical results show that the relaxation time, electrokinetic width, zeta potential, and angular Reynolds number play important roles in determining the velocity and amplitude of electro-osmosis.
Secondary recrystallization of Goss texture in one-stage cold rolled Fe–Ga thin sheets via a large rolling reduction
Authors: He Zhenghua , Zhai Xinya , Sha Yuhui , Zhu Xiaofei , Chen Sihao , Hao Hongbo , Chen Lijia , Li Feng , Zuo Liang
Published: February 2023

Preparing Fe–Ga sheets with excellent magnetostrictive coefficients by rolling and annealing methods can greatly promote the development of high-efficiency magnetostrictive devices. 0.3 mm thick Fe–Ga thin sheet was produced by the one-stage large-reduction cold rolling method without intermediate annealing. Trace V and Nb elements addition improves the rolling formability of the Fe–Ga sheet by precipitating a large number of (Nb,V)C particles. The evolution of precipitation, microstructure, texture, and magnetostrictive coefficients in the Fe–Ga sheet was investigated. The microstructure of primary recrystallization is composed of homogenous distribution of fine grains with an average grain size of about 22 μm. The composite inhibitors composed of MnS and (Nb,V)C precipitates with a particle size of 40∼80 nm suppress the matrix grains effectively. The primary recrystallization texture consists of a strong γ texture with a peak at {111}<112> and a relatively strong {114}<481> texture. The secondary recrystallization of Goss grain occurs at the annealing temperature of 900 °C and is completed at 1100 °C by the combined effects of the existing inhibitor and texture. The Fe–Ga thin sheets composed of several millimeter-sized grains of Goss texture accompanied by small grains oriented by {114}<481> were obtained after annealing at 1100 °C, and its measured magnetostriction value is about 238 ppm. The present work proposes a promising routine to produce high-performance Fe–Ga thin sheets.
Temporal interference for dual site transcranial magnetic stimulation
Authors: Boldrey Joseph , Higgs Zachary , Jiles David C.
Published: February 2023

Dual-site Transcranial Magnetic Stimulation (ds-TMS) is a TMS protocol that involves stimulating two areas of the brain in close succession. This method is useful for studying the connections between two physical parts of the brain. TMS coils are generally designed for use on a single target area in the brain. When ds-TMS targets are in close proximity to one another, using traditional coils in a limited space increases the possibility of errors associated with positioning, resulting in inconsistent pulse strength and trajectory. We developed a single TMS coil that uses temporal interference (TI) to stimulate multiple targets within close proximity without compromising the ideal positioning of either location. TI TMS operates based on the frequency difference of two magnetic fields delivered simultaneously. The frequency difference between the two fields results in an envelope which can be steered to target a different location without moving the coil. We designed a TI-TMS coil and show that the peak induced electric field can be steered 4 cm in either direction (8 cm range) from the center point of the coil while delivering a peak field of 120 V/m, which is above the minimum 100 V/m needed to activate neurons. An experimental model was built using the same dimensions as the simulation model and validated that the physical model is able to steer the magnetic pulse using TI.
Effect of oxidation on the microwave absorption properties of rare-earth intermetallics La2Fe4Co10B
Authors: Li Kewei , Liu Zhou , Wang Yuankang , Zhang Pengyu , Wang Zilong , Xian Cong , Yang Wenyun , Luo Zhaochu , Liu Shunquan , Han Jingzhi , Du Honglin , Wang Changsheng , Yang Jinbo
Published: February 2023

Microwave absorbers are increasingly being used to enhance shielding performance at higher frequencies. Great effort has been made to develop materials with superior reflection loss (RL), thin thickness, wide bandwidth, and low density to improve their performance in electromagnetic microwave absorption. In this work, the rare-earth intermetallics La2Fe4Co10B fine powders with planar magnetocrystalline anisotropy and high magnetization were prepared using the hydrogenation desorption (HD) technique. By heating the obtained magnetic powders in the air to slowly form an oxide layer on their surfaces, its complex permittivity can be tuned without changing its complex permeability, and its microwave absorption performance can be dramatically enhanced due to the improved impedance matching condition. For the La2Fe4Co10B/paraffin composite, the real part of the complex permittivity at 10 GHz can be reduced from 20.1 to 12.8, decreasing 36.3%. Before the oxidation, the RL of La2Fe4Co10B/paraffin composite is only −14.8 dB at 3.3 GHz under 3.4 mm thickness with an effective absorption bandwidth (EAB) of 0.9 GHz. However, after the 10-hour oxidation, the RL changes to −15.6 dB at 13.4 GHz under 1.4 mm thickness with an EAB of 6.2 GHz. As an efficient and lightweight absorber, La2Fe4Co10B/paraffin composite has potential application value in constructing a new microwave absorber.
Anomalous Nernst effect in epitaxially grown Fe4−xNixN films
Authors: Yin Weida , Ito Keita , Tsubowa Yusuke , Tsujikawa Masahito , Shirai Masafumi , Takanashi Koki
Published: February 2023

Anomalous Nernst effect of epitaxial Fe4−xNixN films on MgAl2O4(001) substrates was characterized. The Ni/Fe ratio (x) in Fe4−xNixN films was changed in the range of 0 ≤ x ≤ 2.8, and the Fe4−xNixN phase started to decompose into FeNi at about x = 2.2. The anomalous Nernst coefficient (SANE) decreased with x from 1.7 to 0.6 μV/K and the Seebeck coefficient increased with x from −2.3 to 1.2 μV/K. The transverse thermoelectric conductivity (αxy) evaluated from the experimental data showed a decrease with x and the change of αxy dominated the change of SANE. The anomalous Hall conductivity and αxy of Fe4N and Fe2.8Ni1.2N were obtained by first-principles calculations, showing a significant difference from the experimental results, which might be caused by the contribution from the extrinsic mechanisms.
Human atlastins are sufficient to drive the fusion of liposomes with a physiological lipid composition
Authors: Jang Eunhong , Moon Yeojin , Yoon So Young , Diaz Joyce Anne R. , Lee Miriam , Ko Naho , Park Jongseo , Eom Soo Hyun , Lee Changwook , Jun Youngsoo
Published: February 2023

The dynamin-like GTPase atlastin is believed to be the minimal machinery required for homotypic endoplasmic reticulum (ER) membrane fusion, mainly because Drosophila atlastin is sufficient to drive liposome fusion. However, it remains unclear whether mammalian atlastins, including the three human atlastins, are sufficient to induce liposome fusion, raising doubts about their major roles in mammalian cells. Here, we show that all human atlastins are sufficient to induce fusion when reconstituted into liposomes with a lipid composition mimicking that of the ER. Although the fusogenic activity of ATL1, which is predominantly expressed in neuronal cells, was weaker than that of ATL2 or ATL3, the addition of M1-spastin, a neuron-specific factor, markedly increased ATL1-mediated liposome fusion. Although we observed efficient fusion between ER microsomes isolated from cultured, non-neuronal cells that predominantly express ATL2-1, an autoinhibited isoform of ATL2, ATL2-1 failed to support liposome fusion by itself as reported previously, indicating that cellular factors enable ATL2-1 to mediate ER fusion in vivo.
Double-pulse laser ablation in liquids: nanoparticle bimodality reduction by sub-nanosecond interpulse delay optimization
Authors: Doñate-Buendia C , Spellauge M , Streubel R , Riahi F , Barcikowski S , Huber H P , Gökce B
Published: February 2023

Applications of nanoparticles (NPs) in medicine, energy, catalysis, or additive manufacturing demand the development of NP production methods that are offering material and solvent versatility, high purity, morphology, and size control, together with industrial-scale production capabilities. Pulsed laser ablation in liquids (PLAL) is a technique that comes close to meeting these demands; however, NP size control remains a challenge. To reduce the characteristic bimodality in NPs synthesized by high-intensity PLAL, a double pulse configuration with inter-pulse delays between 300 ps and 1200 ps is proposed. In this temporal delay window, the plume and initial bubble are still flat so that shielding of the second laser pulse by the cavitation bubble is avoided; minimizing pulse shielding that could reduce NP productivity. At a pulse delay of 600 ps, a (9 ± 1) wt% reduction of the large NP fraction is demonstrated (at the expense of mass yield), showing the possibility of modifying the NP size distribution produced in PLAL by temporal pulse shaping.
Estimation of fission barrier heights for even–even superheavy nuclei using machine learning approaches
Authors: Yesilkanat Cafer Mert , Akkoyun Serkan
Published: February 2023

With the fission barrier height information, the survival probabilities of super-heavy nuclei can also be reached. Therefore, it is important to have accurate knowledge of fission barriers, for example, the discovery of super-heavy nuclei in the stability island in the super-heavy nuclei region. In this study, five machine learning techniques, Cubist model, Random Forest, support vector regression, extreme gradient boosting and artificial neural network were used to accurately predict the fission barriers of 330 even–even super-heavy nuclei in the region 140 ≤ N ≤ 216 with proton numbers between 92 and 120. The obtained results were compared both among themselves and with other theoretical model calculation estimates and experimental results. According to the results obtained, it was concluded that the Cubist model, support vector regression and extreme gradient boosting methods generally gave better results and could be a better tool for estimating fission barrier heights.
Stochasticity may generate coherent motion in bird flocks
Authors: Reynolds Andy M
Published: February 2023

Murmurations along with other forms of flocking have come to epitomize collective animal movements. Most studies into these stunning aerial displays have aimed to understand how coherent motion may emerge from simple behavioral rules and behavioral correlations. These studies may now need revision because recently it has been shown that flocking birds, like swarming insects, behave on the average as if they are trapped in elastic potential wells. Here I show, somewhat paradoxically, how coherent motion can be generated by variations in the intensity of multiplicative noise which causes the shape of a potential well to change, thereby shifting the positions and strengths of centres of attraction. Each bird, irrespective of its position in the flock will respond in a similar way to such changes, giving the impression that the flock behaves as one, and typically resulting in scale-free correlations. I thereby show how correlations can be an emergent property of noisy, confining potential wells. I also show how such wells can lead to high density borders, a characteristic of flocks, and I show how they can account for the complex patterns of collective escape patterns of starling flocks under predation. I suggest swarming and flocking do not constitute two distinctly different kinds of collective behavior but rather that insects are residing in relatively stable potential wells whilst birds are residing in unstable potential wells. It is shown how, dependent upon individual perceptual capabilities, bird flocks can be poised at criticality.
Photobiomodulation on extracellular matrix
Authors: da Silva Sergio Luiz Philippe , de Souza da Fonseca Adenilson , Mencalha Andre Luiz , de Paoli Flavia
Published: February 2023

The extracellular matrix (ECM) is a three-dimensional multicomponent, and a structural meshwork constituted of many specialized macromolecules. Such macromolecules provide an essential scaffold to tissue cells and chemical signals involved in cell proliferation, survival, migration, and differentiation, which are crucial to tissue morphogenesis, homeostasis, and functions. Photobiomodulation (PBM) is based on non-ionizing radiations in the visible and infrared spectrum, emitted from low-power lasers, light-emitting diodes, and broadband light sources. PBM has been used for improving tissue repair, and successful results have been reported from experimental studies. In this review, studies were accessed by PubMed, and their findings on PBM-induced effects on the ECM were summarized. The results showed that low-power violet-red lights and near-infrared radiation modulate gene expression, cell proliferation, adhesion and differentiation, factors and enzymes, and structural constituents in the ECM. These results showed a dependence on radiation wavelength, fluence, irradiance, exposure time, emission mode, and cellular and tissue conditions. Such results suggest that the irradiation parameters, biological tissue type, and conditions should be considered for an effective therapeutic protocol aiming at tissue repair based on PBM-induced extracellular matrix remodeling.
Frequency doubling of femtosecond laser pulses in three dimensional nonlinear photonic crystals
Authors: Vyunishev A M , Arkhipkin V G , Chirkin A S
Published: February 2023

Quasi-phase matched nonlinear frequency conversion in three dimensional nonlinear photonic crystals (NPCs) has been considered for implementation of the second harmonic generation of transform-limited and chirped femtosecond laser pulses. Spatial distribution of the second harmonic intensity is shown to be caused by Cherenkov- and Raman–Nath-type nonlinear diffraction. These types of nonlinear diffraction may occur simultaneously resulting in an efficient multi-order nonlinear diffraction in the Bragg regime, which can be realized by a proper choice of the modulation period of NPC structure in longitudinal direction for considered transverse diffraction order. Three dimensional NPCs open up new possibilities for ultrafast nonlinear photonics and parametric interactions in optics.
Relativistic polytropic models of charged anisotropic compact objects
Authors: Nazar H. , Azam M. , Abbas G. , Ahmed Riaz , Naeem R.
Published: February 2023

In this paper, we introduce new viable solutions to the Einstein-Maxwell field equations by incorporating the features of anisotropic matter distributions within the realm of the general theory of relativity (

). To obtain these solutions, we employed the Finch-Skea spacetime, along with a generalized polytropic equation of state (

). We constructed various models of generalized polytropes by assuming different values of the polytropic index, i.e.,

, and

. Next, numerous physical characteristics of these considered models were studied via graphical analysis, and they were found to obey all the essential conditions for astrophysical compact objects. Furthermore, such outcomes of charged anisotropic compact star models could be reproduced in various other cases including linear, quadratic, and polytropic
Spherical harmonics representation of the steady-state membrane potential shift induced by tDCS in realistic neuron models
Authors: Galan-Gadea Adrià , Salvador Ricardo , Bartolomei Fabrice , Wendling Fabrice , Ruffini Giulio
Published: February 2023

Objective. We provide a systematic framework for quantifying the effect of externally applied weak electric fields on realistic neuron compartment models as captured by physiologically relevant quantities such as the membrane potential or transmembrane current as a function of the orientation of the field. Approach. We define a response function as the steady-state change of the membrane potential induced by a canonical external field of 1 V m−1 as a function of its orientation. We estimate the function values through simulations employing reconstructions of the rat somatosensory cortex from the Blue Brain Project. The response of different cell types is simulated using the NEURON simulation environment. We represent and analyze the angular response as an expansion in spherical harmonics. Main results. We report membrane perturbation values comparable to those in the literature, extend them to different cell types, and provide their profiles as spherical harmonic coefficients. We show that at rest, responses are dominated by their dipole terms (

ℓ
=
1

), in agreement with experimental findings and compartment theory. Indeed, we show analytically that for a passive cell, only the dipole term is nonzero. However, while minor, other terms are relevant for states different from resting. In particular, we show how

ℓ
=
0

and

ℓ
=
2

terms can modify the function to induce asymmetries in the response. Significance. This work provides a practical framework for the representation of the effects of weak electric fields on different neuron types and their main regions—an important milestone for developing micro- and mesoscale models and optimizing brain stimulation solutions.
High voltage consolidation of the temperature measurement channels of the LHC superconducting current leads
Authors: Trikoupis N. , Casas-Cubillos J. , Bustamante E.
Published: February 2023

Recurrent dielectric breakdowns on the cryogenics instrumentation during the CERN LHC Electrical Quality Assurance (ELQA) campaigns led to an investigation of their root causes. During the CERN Long Shutdown 2 (LS2), several weaknesses were identified like floating wires or cable screens, cabling non-conformities, connector assembly issues, and weakness of the electronic conditioning cards. The paper presents the cabling layout from the sensor till the acquisition cards and the actions undertaken to increase the robustness against dielectric ruptures. These actions include rebuild of the cabling and connectors using a laser stripping machine, new wiring patterns and upgrades on the electronic cards.
Progress and promise of cell sheet assisted cardiac tissue engineering in regenerative medicine
Authors: Abdolahzadeh Hadis , Rad Niloofar Khoshdel , Shpichka Anastasia , Golroo Reihaneh , Rahi Kosar , Timashev Peter , Hassan Moustapha , Vosough Massoud
Published: February 2023

Cardiovascular diseases (CVDs) are the most common leading causes of premature deaths in all countries. To control the harmful side effects of CVDs on public health, it is necessary to understand the current and prospective strategies in prevention, management, and monitoring CVDs. In vitro, recapitulating of cardiac complex structure with its various cell types is a challenging topic in tissue engineering. Cardiac tissue engineering (CTE) is a multi-disciplinary strategy that has been considered as a novel alternative approach for cardiac regenerative medicine and replacement therapies. In this review, we overview various cell types and approaches in cardiac regenerative medicine. Then, the applications of cell-sheet-assisted CTE in cardiac diseases were discussed. Finally, we described how this technology can improve cardiac regeneration and function in preclinical and clinical models.
3D printing of ‘green’ thermo-sensitive chitosan-hydroxyapatite bone scaffold based on lyophilized platelet-rich fibrin
Authors: Sui Xin , Zhang Huili , Yao Jingjing , Yang Liuqing , Zhang Xiao , Li Lingfeng , Wang Jue , Li Meihui , Liu Zhihui
Published: February 2023

The critical bone defect is still an urgent problem in the field of bone repair. Here, we reported a new type of chitosan (CS)–hydroxyapatite (HAP) scaffolds based on lyophilized platelet-rich fibrin (L-PRF) for releasing abundant growth factors to realize their respective functions. It also has strong mechanical properties to maintain the stability of the bone repair environment. However, acid-soluble CS hydrogels often contain toxic and organic solvents. Moreover, chemical agents may be used for cross-linking for better mechanical properties, further increasing cytotoxicity. In this study, we used an alkali/urea dissolution system to dissolve CS, which improved its mechanical properties and made it thermo-sensitive. Finally, the L-PRF-CS-HAP (P-C-H) composite scaffold was constructed by extrusion-based printing. The results showed that the printing ink had desirable printability and temperature sensitivity. The compressive properties of the scaffolds exhibited a trend of decline with L-PRF content increasing, but all of them could meet the strength of cancellous bone. Meanwhile, the scaffolds had high hydrophilicity, porosity, and could be degraded stably in vitro. The antibacterial properties of the scaffolds were also verified, greatly reducing the risk of infection during bone repair. It was also demonstrated that the release time of growth factor from L-PRF was significantly prolonged, and growth factor could still be detected after 35 d of sustained release. The capacity of cells to proliferate increased as the number of L-PRF components increased, indicating that L-PRF still exhibited biological activity after 3D printing.
A global review of the development and application of soil erosion control techniques
Authors: Wen Xin , Zhen Lin , Jiang Qun’ou , Xiao Yu
Published: February 2023

Various soil erosion control techniques (SECTs) have been applied for decades. Yet, dynamic development of SECTs on a global scale has not been fully explored in the literature. We identified 779 publications to summarize spatial and temporal patterns of SECT development across the world. To achieve this goal, we asked (a) how many SECTs have been applied in the real world? (b) How do susceptible erosion areas use SECTs? And (c) what are the temporal patterns of SECT development? We found 183 sub-categories of SECTs, including 85 sub-categories of engineering techniques, 76 sub-categories of cropping techniques, and 22 sub-categories of biological techniques. In contrast, there is a great deal of interest in the evaluation of biological techniques and cropping techniques for soil erosion control. SECT research has evolved from an initial focus on a single SECT evaluation to a combination of SECTs evaluations (e.g. a combination of conservation tillage and mulch). Likewise, 64% of SECT cases were found in six countries with a different focal SECT among them: China and Spain targeted vegetation restoration, Brazil and the United States focused on conservation tillage, Ethiopia prioritized mixed SECTs, and India emphasized on check dam. Lastly, SECT application started from site erosion control (1930s–1980s), watershed management (1980s–2010s), to sustainable management (after 2010s). We identify the gaps between SECT application and research and a lack of an international platform for knowledge sharing, and propose that a combination of different SETCs in a balanced way is a reliable approach to obtaining the goal of sustainable soil management.
Contributory science reveals insights into metal pollution trends across different households and environmental media
Authors: Dietrich Matthew , Wood Leah R , Shukle John T , Herrmann Angela , Filippelli Gabriel M
Published: February 2023

Heavy metals are prevalent in urban settings due to many legacy and modern pollution sources, and are essential to quantify because of the adverse health effects associated with them. Of particular importance is lead (Pb), because there is no safe level of exposure, and it especially harms children. Through our partnership with community scientists in the Marion County (Indiana, United States) area (n = 162 households), we measured Pb and other heavy metal concentrations in soil, paint, and dust. Community scientists completed sampling with screening kits and samples were analyzed in the laboratory via x-ray fluorescence by researchers to quantify heavy metal concentrations, with Pb hazards reported back to participants. Results point to renters being significantly (p ≤ 0.05) more likely to contain higher concentrations of Pb, zinc (Zn), and copper (Cu) in their soil versus homeowners, irrespective of soil sampling location at the home. Housing age was significantly negatively correlated with Pb and Zn in soil and Pb in dust across all homes. Analysis of paired soil, dust, and paint samples revealed several important relationships such as significant positive correlations between indoor vacuum dust Pb, dust wipe Pb, and outdoor soil Pb. Our collective results point to rental status being an important determinant of metal pollution exposure in Indianapolis, with housing age being reflective of both past and present Zn and Pb pollution at the household scale in dust and soil. Thus, future environmental pollution work examining renters versus homeowners, as well as other household data such as home condition and resident race/ethnicity, is imperative for better understanding environmental disparities surrounding not just Pb, but other heavy metals in environmental media as well.
Separable spaces of continuous functions as Calkin algebras
Authors: Motakis Pavlos
Published: February 2023

It is proved that for every compact metric space

K
K

there exists a Banach space

X
X

whose Calkin algebra

L

(
X
)

/

K

(
X
)

\mathcal {L}(X)/\mathcal {K}(X)

is homomorphically isometric to

C
(
K
)

C(K)

. This is achieved by appropriately modifying the Bourgain-Delbaen

L

∞

\mathscr {L}_\infty

-space of Argyros and Haydon in such a manner that sufficiently many diagonal operators on this space are bounded.