bluuebunny/crossref_metadata_2025 huggingface dataset:
Reversed-direction 2-point modelling applied to divertor conditions in DIII-D
*
Authors: Nichols J H , Stangeby P C , McLean A G , Canik J M , Moser A L , Shafer M W , Wang H Q
Published: February 2024

A predictive form of the extended 2-point model known as the ‘reverse 2-point model’, Rev2PM, is applied to a range of detachment levels in the open lower divertor of DIII-D, showing that the experimentally measured electron temperature (Te
) and pressure (pe
) at the divertor entrance can be calculated within 50% from target measurements, if and only if a posteriori corrections for convective heat flux are included in the model. Unlike the standard 2-point model, the Rev2PM calculates upstream scrape-off layer (SOL) quantities (such as separatrix Te
and pe
) from target conditions (such as Te
and parallel heat flux), with volumetric power and momentum losses depending solely on target Te
. The Rev2PM is tested against a database of DIII-D inter-ELM divertor Thomson scattering measurements, built from a series of 6 MW, 1.3 MA, LSN H-mode discharges with varied main ion density, drift direction, and nitrogen puffing rate. Measured target Te
ranged from 0.4–25 eV over this database, and upstream Te
ranged from 5–60 eV. Poor agreement is found between upstream measurements and Rev2PM calculations that assume purely conductive parallel heat transport. However, introducing a posteriori corrections to account for convective heat transport brings the Rev2PM calculations within 50% of the measured upstream values across the dataset. These corrections imply that up to 99% of the parallel heat flux is carried by convection in detached conditions in the DIII-D open lower divertor, though further work is required to assess any potential dependencies on device size or divertor closure.
Quantification of plasma enabled surface cooling by electron emission from high temperature materials
Authors: Bak Junhwi , Tropina Albina , Creel James , Miles Richard B
Published: February 2024

In this work, the potential for hypersonic leading edge cooling by electron emission is demonstrated. To overcome space charge limitations the experiments are carried out in an argon discharge at 1 Torr. Cooling is observed with time-resolved measurements of the electron emission current and surface temperature, taking advantage of well controlled laser heating of the emitting surface and time accurate surface pyrometry. For the ignited mode of the plasma discharge, surface cooling by the electron emission is directly observed, leading to an estimated cooling rate of

1.6
±
0.2

 MW m−2. Higher cooling rates with self sustained plasmas for space charge mitigation are expected using cesium transpiration. A two-dimensional model of heat transfer has been developed, which reproduces well the experimentally observed cooling dynamics. Parametric tests of emitter materials with various work functions show that for effective surface cooling by electron emission, the optimal work function must be less than 3.0 eV. This result indicates that electron cooling can be a promising thermal protection method for leading edges of hypersonic vehicles in flight.
Memristive effects in YBa2Cu3O7-x devices with transistor-like structure
Authors: Lagarrigue Aurélien , de Dios Carolina , Carreira Santiago J , Humbert Vincent , Mesoraca Salvatore , Briatico Javier , Trastoy Juan , Villegas Javier E
Published: February 2024

Cuprate superconductors are highly sensitive to disorder and oxygen stoichiometry; even minute variations of those parameters drastically change their electronic properties. In this work, we exploit this characteristic to engineer a memristive device based on the high-TC
superconductor YBa2Cu3O7−x
(YBCO), in which local changes of the oxygen content and induced disorder are harnessed to produce memory effects. These effects are electrically triggered in a three-terminal device whose structure is reminiscent of a transistor, consisting of a YBCO channel and an Al gate. The Al/YBCO interface, which controls the gate conductance, displays a large, bipolar, reversible switching across a continuum of non-volatile conductance states spanning over two decades. This phenomenon is controlled by the gate voltage magnitude and is caused by the oxygen exchange between YBCO and Al. Concomitantly, the channel shows a gradual, irreversible superconductor-to-insulator transition that retains a memory of the power dissipated in the device and can be explained by induced bulk disorder. The observed effects, and the understanding of the interplay between the underlying mechanisms, constitute interesting ingredients for the design and realization of novel memristors and switches for superconducting electronics.
Development of persistent joints for superconducting Bi-2212 coils
Authors: Zagura Petr , Kim Ingon , Follows Frederick , Barker Clara , Melhem Ziad , Twin Andrew , Ball Steven , Grovenor Chris , Speller Susannah , Mousavi Tayebeh
Published: February 2024

Bi2Sr2CaCu2O8+x
(Bi-2212) multifilamentary wire is the only high-temperature superconductor manufactured in the form of an isotropic round wire, and so offers a number of advantages for the designers of high field magnets. However, for high-field (>25 T), high-stability magnet applications, ultra-low resistance superconducting joints (R < 10−12 Ω) will be needed to take advantage of the excellent properties of the Bi-2212 wire. This study focuses on the fabrication of compact melt processed joints in small coils of Bi-2212/Ag multifilamentary round wires and the testing of their superconducting performance by inductive resistance measurements. Microstructural analysis is carried out to correlate the microstructure to the superconducting performance of the joints. Our optimized technique led to a reliable process for the preparation of small coils with melt processed joints that occupy very small volumes but can still carry the highest persistent currents reported so far for Bi-2212.
Energetics of magnetized Kerr-MOG and Kerr-Taub-NUT black holes within magnetic Penrose process
Authors: Alibekov Husan , Abdujabbarov Ahmadjon , Ahmedov Bobomurat
Published: February 2024

In this research paper, we have examined the impact of a gravitomagnetic charge on extracting energy from a rotating Kerr-Taub-NUT black hole and Kerr-MOG (MOdified Gravity known as Scalar-Tensor-Vector-Gravity (STVG)) black hole embedded in the magnetic field via the magnetic Penrose process (MPP). Our findings demonstrate that the gravitomagnetic monopole and MOG parameters both significantly influence the extraction of energy from a rotating black hole, exceeding the MPP for the Kerr black hole in terms of energy efficiency. After comparing the results of this study with the observational data, we were confident that our findings on the amplification of MPP by MOG and NUT parameters are nearly in line with the observations of ultrarelativistic particles in the cosmic rays.
Stationary rotating and axially symmetric dust systems as peculiar General Relativistic objects
Authors: Ruggiero Matteo Luca
Published: February 2024

We study an exact solution of Einstein's equations describing a self-gravitating system, made of dust, distributed with axial symmetry and in stationary rotation, and we prove that this type of system has no Newtonian analogue. In a low-energy limit, its existence depends on the solution of a Grad-Shafranov equation in vacuum which can be interpreted as a Laplace equation for the toroidal component of the gravitomagnetic potential; in particular, in this system the relativistic rotational effects are of the order of magnitude of Newtonian ones. We therefore argue that this exact solution should contain singularities and discuss the possible consequences of using such a system as simplified model for galactic dynamics.
Simultaneous detection of boosted dark matter and neutrinos from the semi-annihilation at DUNE
Authors: Aoki Mayumi , Toma Takashi
Published: February 2024

Dark matter direct detection experiments impose the strong bounds on thermal dark matter
scenarios. The bound can naturally be evaded if the cross section is momentum transfer or
velocity dependent. One can test such thermal dark matter scenarios if dark matter particles are
boosted by some mechanism. In this work, we consider a specific semi-annihilation χχ̅→νχ where χ(χ̅) is dark matter (anti-dark matter), and search
for simultaneous detection of the neutrino and the boosted dark matter in the final state at DUNE.
We find that the energies of the neutrino and boosted dark matter are reconstructed by kinematics.
In addition, we find that both signals can be testable at DUNE if the dark matter mass is below
8 GeV, and the scattering cross section is momentum transfer dependent. Even for
larger dark matter masses, the two signals can be tested by combination of DUNE and the other
experiments such as IceCube/DeepCore and Hyper-Kamiokande.
Sub-50 fs pulses generation from an all-fiber monolithic gain-managed nonlinear amplifier with CFBG-based pre-compressor
Authors: Li Qianglong , Li Feng , Liu Hongjun , Zhao Wei , Cao Xue , Zhao Hualong , Wang Yishan , Wen Wenlong , Si Jinhai
Published: February 2024

We demonstrate an all-fiber monolithic laser source from a gain-managed nonlinear (GMN) fiber amplifier with a CFBG-based pre-compressor that generates high-contrast pulses with a repetition rate of 80 MHz, average power of 1.6 W, and pulse duration of sub-50 fs. The compressed pulse quality can be optimized by tuning the parameters of the seed pulses injected into the GMN amplifier by controlling the pump power of the fiber pre-amplifier. This compact and cost-effective laser system is a simplified design of the GMN amplification-based femtosecond fiber laser systems. With alignment-free characteristics in the amplifiers and clean compressed pulses, it is easy to assemble and use in applications such as multi-photon microscopy.
The 23 Factorial Design in R
Authors: Hodžić D , Crnkić A , Rošić H , Hasanagić R
Published: February 2024

The paper describes the factorial design of the experiment with three input factors that change on two levels. For given values of the input parameters, it is shown how to obtain a variance analysis table and which factors and interactions between factors are significant. The example was done in the software intended for the design of the experiment and in the software R. It is shown how to use the software R to arrive at the final solution of the given example.
A Review on artificial pancreas mathematical models
Authors: Gavrila B T , Balas V E , Balas M M
Published: February 2024

The development of an artificial pancreas (AP) has been a topic of interest in the field of diabetes management for several decades. An AP system is designed to mimic the function of the pancreas by continuously monitoring blood glucose levels and delivering insulin or glucagon in response to changes in glucose concentration. Mathematical models play a crucial role in the development and evaluation of AP systems, as they enable the simulation and prediction of the system’s performance. This review paper provides an overview of the mathematical models used in AP research. The paper discusses the strengths and limitations of each type of model, as well as their applications in AP research. The review also highlights the challenges and opportunities in AP model development, such as the need for personalized models and the integration of data from multiple sources. Overall, this review provides a comprehensive understanding of the role of mathematical models in AP research and their potential for improving diabetes management.
An automated approach for traffic light control at pedestrian crossings
Authors: Stroia M D , Hațiegan C , Preduș M F , Muscai C
Published: February 2024

Although technology has evolved explosively in past years in all aspects of our lives and should make our work easier, it still seems like we don’t have enough time and we are in a constant rush. We hurry when we go to work or shopping, when we drive, when we cross the street. Nevertheless, we have clear traffic rules that aim to protect us from possible road accidents, has the thought ever occurred that we could cross the street if no one is crossing, even if the traffic light is red? In this idea, we thought of a different approach to control the alternation of the traffic light, other than through the timer, so as to reduce the waiting times at the traffic light crossing. This traffic light automation solution is detailed in the present paper in which we describe the structural components and operating principles of an improved traffic light model. The main objective for implementing this improved model is to eliminate the waiting dead times at the traffic light crossing.
Impact of electrical equipment on the power factor
Authors: Spunei E , Piroi I , Piroi F
Published: February 2024

A large proportion of electricity consumers alter the electricity quality through the equipment they use. The alteration is caused by a drop in the power factor, which leads to additional losses in the power grid and additional reactive power costs. In order to identify the consumers’ electrical equipment that alter the power factor, we monitor their electricity use in a production hall looking at the variation of the effective average values of voltages, currents, powers and power factor. The analysis of these records gives us the difference between the power factor and cos φ (the phase difference between phase voltage and phase current in single-phase operation). Our monitoring shows, at the same time, the necessity of an individual analysis of each electrical equipment in the production hall under observation, as well the necessity to locally compensate the power factor.
Dynamic simulation of the differential gear in road vehicles
Authors: Miklos I Zs , Miklos C C , Alic C I
Published: February 2024

The differential gear is a mechanism that is part of the kinematic chain of the vehicle’s transmission. The differential gear has the role of dividing the self-propulsion power flow received from the main drive into two branches, each transmitted to a drive wheel, giving them the possibility to rotate with different angular velocities, depending on the driving conditions. The present work presents the possibilities of computer-aided design and 3D modeling of the main drive and differential gear, respectively the bevel pinion, the crown wheel, the planet pinions and the satellites, using Autodesk Inventor Professional. The 3D model of the main drive - differential gear assembly, considered as a mechanism, was subjected to a dynamic study, using the Dynamic Simulation module. This involves the modeling of the kinematic couplings, the definition of the drive movement parameters and the external loads, respectively the graphical visualization of the kinematic and kinetostatic results for the various components of the mechanism, in real operating conditions, during a kinematic cycle. At the same time, based on the obtained results, the analysis by the finite element method of the most critical component elements, under straight-line driving and turning conditions, is presented.
Fast coherent control of nitrogen-14 spins associated with nitrogen-vacancy centers in diamonds using dynamical decoupling
Authors: Mizuno Kosuke , Fujisaki Ikuya , Tomioka Hiroyoshi , Ishiwata Hitoshi , Onoda Shinobu , Iwasaki Takayuki , Arai Keigo , Hatano Mutsuko
Published: February 2024

A nitrogen-vacancy (NV) center in a diamond enables the access to an electron spin, which is expected to present highly sensitive quantum sensors. Although exploiting a nitrogen nuclear spin improves the sensitivity, manipulating it using a resonant pulse requires a long gate time owing to its small gyromagnetic ratio. Another technique to control nuclear spins is a conditional rotation gate based on dynamical decoupling, which is faster but unavailable for nitrogen spins owing to the lack of transverse hyperfine coupling with the electron spin. In this study, we generated effective transverse coupling by applying a weak off-axis magnetic field. An effective coupling depends on the off-axis field; the conditional rotation gate on the nitrogen-14 spins of an NV center was demonstrated within 4.2 μs under an 1.8% off-axis field and a longitudinal field of approximately 280 mT. We estimated that a population transfer from the electron to nitrogen spins can be implemented with 8.7 μs. Our method is applicable to an ensemble of NV centers, in addition to a single NV center.
Advance in twisted transition metal dichalcogenides: synthesis, characterization, and properties
Authors: Yang Yueting , Duan Zhuojun , Li Huimin , Liu Song
Published: February 2024

The twist angle regulation strategy provides a feasible tool for studying the emerging properties of transition metal dichalcogenides (TMDCs). For the twisted TMDCs (t-TMDCs), there is the lattice mismatch and twist between layers, thus forming moiré superlattice. The formation of moiré superlattice brings about innovative properties to the t-TMDCs. These innovative properties have attracted more and more attention from researchers. This review firstly focuses on the synthesis methods of t-TMDCs, as well as the merits and shortcomings of each method. Secondly, the common spectral characterization and microscopic characterization methods are discussed. Thirdly, the prominent properties of t-TMDCs are briefly demonstrated, including ferroelectricity, flat band, and interlaminar excitons. Finally, we look forward to the potential application prospect and research direction of t-TMDCs.
High-performance liquid metal electromagnetic actuator fabricated by femtosecond laser
Authors: Chen Yiyu , Wu Hao , Li Rui , Jiang Shaojun , Zhou Shuneng , Cui Zehang , Tao Yuan , Zheng Xinyuan , Zhang Qianqian , Li Jiawen , Li Guoqiang , Wu Dong , Chu Jiaru , Hu Yanlei
Published: February 2024

Small-scale electromagnetic soft actuators are characterized by a fast response and simple control, holding prospects in the field of soft and miniaturized robotics. The use of liquid metal (LM) to replace a rigid conductor inside soft actuators can reduce the rigidity and enhance the actuation performance and robustness. Despite research efforts, challenges persist in the flexible fabrication of LM soft actuators and in the improvement of actuation performance. To address these challenges, we developed a fast and robust electromagnetic soft microplate actuator based on a laser-induced selective adhesion transfer method. Equipped with unprecedentedly thin LM circuit and customized low Young’s modulus silicone rubber (1.03 kPa), our actuator exhibits an excellent deformation angle (265.25°) and actuation bending angular velocity (284.66 rad·s−1). Furthermore, multiple actuators have been combined to build an artificial gripper with a wide range of functionalities. Our actuator presents new possibilities for designing small-scale artificial machines and supports advancements in ultrafast soft and miniaturized robotics.
An empirical experimental observations and MD simulation data-based model for the material properties of confined fluids in nano/Angstrom size tubes
Authors: Garg Ashish , Bishnoi Swati
Published: February 2024

The transport of fluids in nanometer and Angstrom-sized pores has gotten much attention because of its potential uses in nanotechnology, energy storage, and healthcare sectors. Understanding the distinct material properties of fluids in such close confinement is critical for enhancing their performance in various applications. These properties dictate the fluid’s behavior and play a crucial role in determining flow dynamics, transport processes, and, ultimately, the performance of nanoscale devices. Remarkably, many researchers observed that the size of the geometry, such as the diameter of the confining nanotube, exerts a profound and intriguing influence on the material properties of nanoconfined fluids, including on the critical parameters such as density, viscosity, and slip length. Many researchers tried to model these material properties: viscosity η, density ρ, and slip λ using various models with many dependencies on the tube diameter. It is somewhat confusing and tough to decide which model is appropriate and needs to be incorporated in the numerical simulation. In this paper, we tried to propose a simple single equation for each nano confined material property such as for density

ρ

(
D
)

/

ρ

o

=
a
+
b

/

(
D
−
c
)

n

, viscosity

η

(
D
)

/

η

o

=
a
+
b

/

(
D
−
c
)

n

, and the slip length λ(D) = λ
1
D
e
−n
D
+ λ

o
(where a, b, c, n, λ
1, λ

o
are the free fitting parameters). We model a wealth of previous experimental and MD simulation data from the literature using our proposed model for each material property of nanoconfined fluids at the nanometer and Angstrom scales. Our single proposed equation effectively captures and models all the data, even though many different models have been employed in the existing literature to describe the same material property. Our proposed model exhibits exceptional agreement with multiple independent datasets from the experimental observations and molecular dynamics simulations. Additionally, the model possesses the advantageous properties of continuity and a continuous derivative, so the proposed model is well-suited for integration into numerical simulations. Further, the proposed models also obey the far boundary conditions, i.e., when tube diameter D ⟹ ∞, the material properties tend to the bulk properties of the fluid. Due to the models’ simplicity, smooth, and generic nature, this heuristic model holds promise to apply in simulations to design and optimize nanoscale devices.
In situ doping effect in monolayer MoS2 via laser irradiation
Authors: Wang Peng , Gao Bo , Liu Wenjun
Published: February 2024

Two-dimensional (2D) semiconducting materials with a single atomic layer display exceptional structural symmetry and band structures, making them the most promising candidates for investigating the spin-valley coupling effect and fabricating novel optoelectronic devices. Their atomic thinness also makes it easy to adjust their excitonic optical response through plasma treatment or thermal annealing. In this study, we present a simple technique for modifying the optical properties of monolayer MoS2 by briefly exposing it to laser irradiation in ambient conditions. Initially, this exposure resulted in a nearly twofold increase in photoluminescence (PL) intensity, with the neutral exciton intensity increasing while the trion exciton intensity decreased. We propose that oxygen-related functional groups, such as O2 and H2O from the surrounding air, adsorb onto MoS2 and extract extra electrons, which enhances exciton emission while reducing trion emission. In a subsequent stage, both exciton intensities decreased as all extra electrons were depleted. Additionally, any structural distortions or potential damage were found to decrease the PL intensity, and these changes were linked to alterations in the Raman spectra.
Tepsin binds LC3B to promote ATG9A trafficking and delivery
Authors: Wallace Natalie S. , Gadbery John E. , Cohen Cameron I. , Kendall Amy K. , Jackson Lauren P.
Published: February 2024

Tepsin is an established accessory protein found in Adaptor Protein 4 (AP-4) coated vesicles, but the biological role of tepsin remains unknown. AP-4 vesicles originate at the trans-Golgi network (TGN) and target the delivery of ATG9A, a scramblase required for autophagosome biogenesis, to the cell periphery. Using in silico methods, we identified a putative LC3-Interacting Region (LIR) motif in tepsin. Biochemical experiments using purified recombinant proteins indicate tepsin directly binds LC3B preferentially over other members of the mammalian ATG8 family. Calorimetry and structural modeling data indicate this interaction occurs with micromolar affinity using the established LC3B LIR docking site. Loss of tepsin in cultured cells dysregulates ATG9A export from the TGN as well as ATG9A distribution at the cell periphery. Tepsin depletion in a mRFP-GFP-LC3B HeLa reporter cell line using siRNA knockdown increases autophagosome volume and number, but does not appear to affect flux through the autophagic pathway. Reintroduction of wild-type tepsin partially rescues ATG9A cargo trafficking defects. In contrast, reintroducing tepsin with a mutated LIR motif or missing N-terminus drives diffuse ATG9A subcellular distribution. Together, these data suggest roles for tepsin in cargo export from the TGN; ensuring delivery of ATG9A-positive vesicles; and in overall maintenance of autophagosome structure.
The Virtue of the Bench
Authors: Sheen Erica
Published: February 2024

This chapter extends Chapter 2’s discussion of international law to the Nuremberg war crimes trials. Taking its starting point from an after-dinner speech about the Anglo-American ‘special relationship’, it discusses ‘Law and Literature’ principles of advocacy, particularly those of Sir Norman Birkett, who looked to Shakespeare for the ‘insight, the understanding and the judgment’ that defend ‘the virtue of the bench’. It applies these ideas to USA v Oswald Pohl et al. (1947), one of the Nuremberg ‘Subsequent’ Trials, in which seventeen members of the SS were tried for crimes against peace, war crimes, crimes against humanity, and conspiracy, and where Shakespearian quotation creates a comic, perhaps even shocking, conviviality between American and German lawyers engaged in the prosecution and defence of Nazi war criminals. It considers the question of Shakespeare’s implication in the ‘culture of forgetting’ that followed the establishment of West Germany in 1949.
A World Stage
Authors: Sheen Erica
Published: February 2024

In April 1949, the US State Department announced the selection of an American theatre company to take a production of Hamlet to the Shakespeare Festival in Elsinore. This chapter tracks the entangled agencies that saw the production through sponsorship by ANTA (American National Theater and Academy), and the personal involvement of President Harry Truman and his White House staff, to the conflicting political commitments of the production’s creative team: producer-financier Blevins Davis, designer Nat Karson, actor-director (and Hamlet) Robert Breen, and veteran British actor Clarence Derwent (Polonius and President of Equity). It shows how the cooperative principles associated with the production’s affiliation to ANTA began to founder under the combined pressures of Breen and Davies’s aspiration to establish their partnership as a state–private enterprise and the association of Karson and Derwent with ‘un-American’ political activities.
A puzzle about guessing and inquiry
Authors: Teague Richard
Published: February 2024

I discuss a puzzle that arises as an apparent tension between plausible theories of good guessing and intuitive constraints on rational inquiry. Clearly, our best guess at a question should reflect the likelihoods we assign to its possible answers. Your best guess is the answer you judge most likely. Additionally, it seems like a requirement of rational inquiry that our guesses be coherent. Thus, our best guess to a constituent (wh-) questions should cohere with our best guess to a polar (yes/no) question whenever answers to the former entail answers to the latter. I argue that these requirements are in conflict and that a familiar form of contextualism doesn’t resolve the issue. The puzzle stands as a challenge to existing accounts of rational inquiry and question directed attitudes like guessing.
Improving image quality consistency and diagnostic accuracy in lower extremity CT angiography using a split-bolus contrast injection protocol
Authors: Tian Qian , Zhu Shumeng , Cheng Yannan , Li Jianying , Qu Tingting , Jia Xiaoqian , Cao Le , Chen Lihong , Guo Jianxin
Published: February 2024

Objectives

To evaluate the clinical value of using a split-bolus contrast injection protocol in improving image quality consistency and diagnostic accuracy in lower extremity CT angiography (CTA).

Methods

Fifty (mean age, 66 ± 12 years) and 39 (mean age, 66 ± 11 years) patients underwent CTA in the lower extremity arteries using split-bolus and fixed-bolus injection schemes, respectively. The objective and subjective image quality of the 2 groups were compared and the diagnostic efficacy for the degree of vessel stenosis was compared using digital subtraction angiography as the gold standard. A P < .05 was considered statistically significant.

Results

In comparison with the fixed-bolus scheme, the split-bolus scheme greatly improved the consistency of image quality of the low extremities by significantly increasing the arterial enhancement (337.87 ± 64.67HU vs. 254.74 ± 71.58HU, P < .001), signal-to-noise ratio (22.58 ± 11.64 vs. 7.14 ± 1.98, P < .001), and contrast-to-noise ratio (37.21 ± 10.46 vs. 31.10 ± 15.40, P = .041) in the infrapopliteal segment. The subjective image quality was better (P < .001) and the diagnostic accuracy was higher in the split-bolus group than in the fixed-bolus group (96.00% vs. 91.67%, P < .05, for diagnosing >50% stenosis, and 97.00% vs. 89.10%, P < .05, for diagnosing occlusion) for the infrapopliteal segment arteries.

Conclusions

Compared with the fixed-bolus injection scheme, the split-bolus injection scheme improves the image quality consistency and diagnostic accuracy especially for the infrapopliteal segment arteries in lower extremity CTA.

Advances in knowledge

(1) The split-bolus injection scheme of CTA of the lower extremity arteries improves the overall image quality, uniformity of contrast enhancement. (2) Compared with the fixed-bolus injection scheme, the split-bolus injection scheme especially improves the infrapopliteal segment arteries image quality and diagnostic efficacy.
Electrochemically assisted polymerization synthesis of ZIF-derived Fe-N/C with high oxygen reduction reaction activity
Authors: Zhao Junhui , Wu Tao , He Qishan , Fang Huiyuan , Liu Mingshuang , Liu Yumin , Zhou Zijian , Zhang Junyu , Yang Weihua
Published: February 2024

The zeolitic imidazolate framework-8 (ZIF-8)-derived Fe-N/C catalysts show excellent oxygen reduction reactions (ORR) performance, but the harsh synthesis conditions and low yields have greatly limited their commercialization. Herein, we report an electrochemical-assisted polymerization method to produce a Fe-N/C structure (EC-Fe-N/C) with a high surface area (954.583 m2 g−1), high dispersion of Fe (2.2 wt %), and abundant N (2.05 wt %). The hierarchical structure exhibits excellent ORR activity (half-wave potential 0.88 V, in alkaline media) and outstanding zinc-air battery performance (energy density 821.3 mAh g−1 Zn, specific capacity 1017.1 Wh kg−1 Zn). This work may provide a simple and effective strategy to rationally design the Fe-N/C porous structure for highly efficient ORR activity.
Dietary Magnesium Intake Is Inversely Associated With Ulcerative Colitis: A Case–Control Study
Authors: Sadeghi Omid , Khademi Zeinab , Saneei Parvane , Hassanzadeh-Keshteli Ammar , Daghaghzadeh Hamed , Tavakkoli Hamid , Adibi Peyman , Esmaillzadeh Ahmad
Published: February 2024

Background

Ulcerative colitis (UC) causes long-lasting inflammation and ulcers in the gut. Limited observational data are available linking dietary magnesium intake and UC. In the present study, we aimed to investigate the association between dietary magnesium intake and UC in adults.

Methods

The current population-based case–control study was performed on 109 UC patients and 218 age (±2 years) and sex-matched controls. The diagnosis of UC was made according to the standard criteria by a gastroenterology specialist. Dietary intakes were assessed using a validated self-administrated 106-item dish-based Food Frequency Questionnaire (FFQ). We also used a pretested questionnaire to collect data on potential confounders.

Results

Individuals in the top tertile of magnesium intake were less likely to have UC compared with those in the bottom tertile. A significant inverse relationship was found between dietary magnesium intake and UC (odds ratio [OR]: 0.32, 95% confidence interval [CI]: 0.18–0.59) in the crude model. This relationship was also observed when we took several potential confounding into account (OR: 0.30, 95% CI: 0.14–0.68).

Conclusions

Adherence to a magnesium-rich diet may have a role in preventing UC. However, further studies are needed to confirm our findings.
Characterization of adaptation mechanisms in sorghum using a multireference back-cross nested association mapping design and envirotyping
Authors: Garin Vincent , Diallo Chiaka , Tékété Mohamed Lamine , Théra Korotimi , Guitton Baptiste , Dagno Karim , Diallo Abdoulaye G , Kouressy Mamoutou , Leiser Willmar , Rattunde Fred , Sissoko Ibrahima , Touré Aboubacar , Nébié Baloua , Samaké Moussa , Kholovà Jana , Berger Angélique , Frouin Julien , Pot David , Vaksmann Michel , Weltzien Eva , Témé Niaba , Rami Jean-François
Published: February 2024

Identifying the genetic factors impacting the adaptation of crops to environmental conditions is of key interest for conservation and selection purposes. It can be achieved using population genomics, and evolutionary or quantitative genetics. Here we present a sorghum multireference back-cross nested association mapping population composed of 3,901 lines produced by crossing 24 diverse parents to 3 elite parents from West and Central Africa-back-cross nested association mapping. The population was phenotyped in environments characterized by differences in photoperiod, rainfall pattern, temperature levels, and soil fertility. To integrate the multiparental and multi-environmental dimension of our data we proposed a new approach for quantitative trait loci (QTL) detection and parental effect estimation. We extended our model to estimate QTL effect sensitivity to environmental covariates, which facilitated the integration of envirotyping data. Our models allowed spatial projections of the QTL effects in agro-ecologies of interest. We utilized this strategy to analyze the genetic architecture of flowering time and plant height, which represents key adaptation mechanisms in environments like West Africa. Our results allowed a better characterization of well-known genomic regions influencing flowering time concerning their response to photoperiod with Ma6 and Ma1 being photoperiod-sensitive and the region of possible candidate gene Elf3 being photoperiod-insensitive. We also accessed a better understanding of plant height genetic determinism with the combined effects of phenology-dependent (Ma6) and independent (qHT7.1 and Dw3) genomic regions. Therefore, we argue that the West and Central Africa-back-cross nested association mapping and the presented analytical approach constitute unique resources to better understand adaptation in sorghum with direct application to develop climate-smart varieties.
High-resolution source imaging and moment tensor estimation of acoustic emissions during brittle creep of basalt undergoing carbonation
Authors: Bai Tong , Xing Tiange , Peč Matěj , Nakata Nori
Published: February 2024

As the high-frequency analogue to field-scale earthquakes, acoustic emissions (AEs) provide a valuable complement to study rock deformation mechanisms. During the load-stepping creep experiments with CO2-saturated water injection into a basaltic sample from Carbfix site in Iceland, 8791 AE events are detected by at least one of the seven piezoelectric sensors. Here, we apply a cross-correlation-based source imaging method, called geometric-mean reverse-time migration (GmRTM) to locate those AE events. Besides the attractive picking-free feature shared with other waveform-based methods (e.g. time-reversal imaging), GmRTM is advantageous in generating high-resolution source images with reduced imaging artefacts, especially for experiments with relatively sparse receivers. In general, the imaged AE locations are found to be scattered across the sample, suggesting a complicated fracture network rather than a well-defined major shear fracture plane, in agreement with X-ray computed tomography imaging results after retrieval of samples from the deformation apparatus. Clustering the events in space and time using the nearest-neighbour approach revealed a group of ‘repeaters’, which are spatially co-located over an elongated period of time and likely indicate crack, or shear band growth. Furthermore, we select 2196 AE events with high signal-to-noise-ratio (SNR) and conduct moment tensor estimation using the adjoint (backpropagated) strain tensor fields at the locations of AE sources. The resulting AE locations and focal mechanisms support our previously assertion that creep of basalt at the experimental conditions is accommodated dominantly by distributed microcracking.
Identification of Highly Repetitive Enhancers with Long-range Regulation Potential in Barley via STARR-seq
Authors: Zhou Wanlin , Shi Haoran , Wang Zhiqiang , Huang Yuxin , Ni Lin , Chen Xudong , Liu Yan , Li Haojie , Li Caixia , Liu Yaxi
Published: February 2024

Enhancers are DNA sequences that can strengthen transcription initiation. However, the global identification of plant enhancers is complicated due to uncertainty in the distance and orientation of enhancers, especially in species with large genomes. In this study, we performed self-transcribing active regulatory region sequencing (STARR-seq) for the first time to identify enhancers across the barley genome. A total of 7323 enhancers were successfully identified, and among 45 randomly selected enhancers, over 75% were effective as validated by a dual-luciferase reporter assay system in the lower epidermis of tobacco leaves. Interestingly, up to 53.5% of the barley enhancers were repetitive sequences, especially transposable elements (TEs), thus reinforcing the vital role of repetitive enhancers in gene expression. Both the common active mark H3K4me3 and repressive mark H3K27me3 were abundant among the barley STARR-seq enhancers. In addition, the functional range of barley STARR-seq enhancers seemed much broader than that of rice or maize and extended to ±100 kb of the gene body, and this finding was consistent with the high expression levels of genes in the genome. This study specifically depicts the unique features of barley enhancers and provides available barley enhancers for further utilization.
Examples of Non-Rigid, Modular Vector Bundles on Hyperkähler Manifolds
Authors: Fatighenti Enrico
Published: February 2024

We exhibit examples of slope-stable and modular vector bundles on a hyperkähler manifold of K3$^{[2]}$-type, which move in a 20-dimensional family and study their algebraic properties. These are obtained by performing standard linear algebra constructions on the examples studied by O’Grady of (rigid) modular bundles on the Fano varieties of lines of a general cubic four-fold and the Debarre–Voisin hyperkähler manifold.
Analysis of Archival Sera From Norovirus-Infected Individuals Demonstrates That Cross-Blocking of Emerging Viruses Is Genotype-Specific
Authors: Pilewski Kelsey A , Ford-Siltz Lauren A , Tohma Kentaro , Kendra Joseph A , Landivar Michael , Parra Gabriel I
Published: February 2024

Background

Rapidly evolving RNA viruses, such as human norovirus, generate extraordinary sequence diversity, posing a significant challenge to vaccine design. This diversity, coupled with short-lasting natural immunity, leads to reinfection throughout one's lifetime. How reexposure shapes humoral immunity to future norovirus strains remains incompletely understood.

Methods

We profiled the antibody responses following 2 community gastroenteritis outbreaks with GII.2 and GII.6 noroviruses in 1971. Using diverse virus-like particles (VLPs), enzyme-linked immunosorbent assay (ELISA), and carbohydrate-blocking assays (surrogate for neutralization), we examined the antibody response at acute and convalescent timepoints following GII.6 infection.

Results

Convalescent sera displayed strong homologous blocking, demonstrating a 5-fold increase in GII.6 carbohydrate blockade over acute samples, and broad blocking of diverse archival and modern GII.6 noroviruses. Convalescent sera displayed limited carbohydrate blocking of heterotypic VLPs, despite high ELISA binding titers. Select individuals developed broad cross-genotype blockade, but this response was established before the second outbreak. Finally, we applied a novel competitive carbohydrate-blocking assay to demonstrate the epitope specificity and discrete compartments of the neutralizing response.

Conclusions

Our data show that infection generates narrow, focused immunity directed toward the infecting genotype. We did detect broad cross-blocking in specific individuals, but these responses could be attributed to diverse, genotype-specific antibodies predating GII.6 infection.
COVID-19 hospitalization risk after outpatient nirmatrelvir/ritonavir use, January to August 2022, North Carolina
Authors: Henderson Heather I , Wohl David A , Fischer William A , Bartelt Luther A , van Duin David , Agil Deana M , Browne Lindsay E , Li Kuo-Ping , Moy Amanda , Eron Joseph J , Napravnik Sonia
Published: February 2024

Background

In the USA, nirmatrelvir/ritonavir is authorized for the treatment of mild-to-moderate COVID-19 in patients at least 12 years of age, at high risk for progression to severe COVID-19.

Objectives

To estimate the impact of outpatient nirmatrelvir/ritonavir on COVID-19 hospitalization risk in a US healthcare system.

Methods

We conducted a cohort study using electronic health records among outpatients with a positive SARS-CoV-2 PCR test between January and August 2022. We evaluated the association of nirmatrelvir/ritonavir therapy with time to hospitalization by estimating adjusted HRs and assessed the impact of nirmatrelvir/ritonavir on predicted COVID-19 hospitalizations using machine-learning methods.

Results

Among 44 671 patients, 4948 (11%) received nirmatrelvir/ritonavir, and 201 (0.4%) were hospitalized within 28 days of COVID-19 diagnosis. Nirmatrelvir/ritonavir recipients were more likely to be older, white, vaccinated, have comorbidities and reside in areas with higher average socioeconomic status. The 28 day cumulative incidence of hospitalization was 0.06% (95% CI: 0.02%–0.17%) among nirmatrelvir/ritonavir recipients and 0.52% (95% CI: 0.46%–0.60%) among non-recipients. For nirmatrelvir/ritonavir versus no therapy, the age-adjusted HR was 0.08 (95% CI: 0.03–0.26); the fully adjusted HR was 0.16 (95% CI: 0.05–0.50). In the machine-learning model, the primary features reducing predicted hospitalization risk were nirmatrelvir/ritonavir, younger age, vaccination, female gender and residence in a higher socioeconomic status area.

Conclusions

COVID-19 hospitalization risk was reduced by 84% among nirmatrelvir/ritonavir recipients in a large, diverse healthcare system during the Omicron wave. These results suggest that nirmatrelvir/ritonavir remained highly effective in a setting substantially different than the original clinical trials.
Molecular structure and function of mysterin/RNF213
Authors: Morito Daisuke
Published: February 2024

Mysterin is a large intracellular protein harboring a RING finger ubiquitin ligase domain and is also referred to as RING finger protein 213 (RNF213). The author performed the first molecular cloning of the mysterin gene as the final step in genetic exploration of cerebrovascular moyamoya disease (MMD) and initiated the next round of exploration to understand its molecular and cellular functions. Although much remains unknown, accumulating findings suggest that mysterin functions in cells by targeting massive intracellular structures, such as lipid droplets (LDs) and various invasive pathogens. In the latter case, mysterin appears to directly surround and ubiquitylate the surface of pathogens and stimulate cell-autonomous antimicrobial reactions, such as xenophagy and inflammatory response. To date, multiple mutations causing MMD have been identified within and near the RING finger domain of mysterin; however, their functional relevance remains largely unknown. Besides the RING finger, mysterin harbors a dynein-like ATPase core and an RZ finger, another ubiquitin ligase domain unique to mysterin, while functional exploration of these domains has also just commenced. In this review, the author attempts to summarize the core findings regarding the molecular structure and function of the mysterin protein, with an emphasis on the perspective of MMD research.
Fructooligosaccharides act on the gut–bone axis to improve bone independent of Tregs and alter osteocytes in young adult C57BL/6 female mice
Authors: Islam Proapa , Ice John A , Alake Sanmi E , Adedigba Pelumi , Hatter Bethany , Robinson Kara , Clarke Stephen L , Ford Versypt Ashlee N , Ritchey Jerry , Lucas Edralin A , Smith Brenda J
Published: February 2024

Targeting the gut–bone axis with probiotics and prebiotics is considered as a promising strategy to reduce the risk of osteoporosis. Gut-derived short chain fatty acids (SCFA) mediate the effects of probiotics on bone via Tregs, but it is not known whether prebiotics act through a similar mechanism. We investigated how 2 different prebiotics, tart cherry (TC) and fructooligosaccharide (FOS), affect bone, and whether Tregs are required for this response. Eight-wk-old C57BL/6 female mice were fed with diets supplemented with 10% w/w TC, FOS, or a control diet (Con; AIN-93M) diet, and they received an isotype control or CD25 Ab to suppress Tregs. The FOS diet increased BMC, density, and trabecular bone volume in the vertebra (~40%) and proximal tibia (~30%) compared to the TC and control diets (Con), irrespective of CD25 treatment. Both prebiotics increased (P < .01) fecal SCFAs, but the response was greater with FOS. To determine how FOS affected bone cells, we examined genes involved in osteoblast and osteoclast differentiation and activity as well as genes expressed by osteocytes. The FOS increased the expression of regulators of osteoblast differentiation (bone morphogenetic protein 2 [Bmp2], Wnt family member 10b [Wnt10b] and Osterix [Osx]) and type 1 collagen). Osteoclasts regulators were unaltered. The FOS also increased the expression of genes associated with osteocytes, including (Phex), matrix extracellular phosphoglycoprotein (Mepe), and dentin matrix acidic phosphoprotein 1 (Dmp-1). However, Sost, the gene that encodes for sclerostin was also increased by FOS as the number and density of osteocytes increased. These findings demonstrate that FOS has a greater effect on the bone mass and structure in young adult female mice than TC and that its influence on osteoblasts and osteocytes is not dependent on Tregs.
The MeerKAT 1.3 GHz Survey of the Small Magellanic Cloud
Authors: Cotton W D , Filipović M D , Camilo F , Indebetouw R , Alsaberi R Z E , Anih J O , Baker M , Bastian T S , Bojičić I , Carli E , Cavallaro F , Crawford E J , Dai S , Haberl F , Levin L , Luken K , Pennock C M , Rajabpour N , Stappers B W , van Loon J Th , Zijlstra A A , Buchner S , Geyer M , Goedhart S , Serylak M
Published: February 2024

We present new radio continuum images and a source catalogue from the MeerKAT survey in the direction of the Small Magellanic Cloud. The observations, at a central frequency of 1.3 GHz across a bandwidth of 0.8 GHz, encompass a field of view ∼7° × 7° and result in images with resolution of 8 arcsec. The median broad-band Stokes I image Root Mean Squared noise value is ∼11 μJy beam−1. The catalogue produced from these images contains 108 330 point sources and 517 compact extended sources. We also describe a UHF (544–1088 MHz) single pointing observation. We report the detection of a new confirmed Supernova Remnant (SNR; MCSNR J0100–7211) with an X-ray magnetar at its centre and 10 new SNR candidates. This is in addition to the detection of 21 previously confirmed SNRs and two previously noted SNR candidates. Our new SNR candidates have typical surface brightness an order of magnitude below those previously known, and on the whole they are larger. The high sensitivity of the MeerKAT survey also enabled us to detect the bright end of the SMC Planetary Nebulae (PNe) sample – point-like radio emission is associated with 38 of 102 optically known PNe, of which 19 are new detections. Lastly, we present the detection of three foreground radio stars amidst 11 circularly polarized sources, and a few examples of morphologically interesting background radio galaxies from which the radio ring galaxy ESO 029–G034 may represent a new type of radio object.