bluuebunny/crossref_metadata_2025 huggingface dataset:
Facile fabrication of micropattern surfaces with controlled wettability on PDMS-modified fiber membranes for cell patterning
Authors: Xie Chenchen , Sun Baishun , Liu Ri , Qu Kaige , Zhang Wenxiao , Weng Zhankun , Wang Zuobin
Published: April 2022

The preparation method of modified fiber membranes provides a novel approach to develop cell culture matrices for cell patterning in tissue engineering.
Colorimetric determination of tetracyclines based on aptamer-mediated dual regulation of gold nanoparticle aggregation and in situ silver metallization
Authors: Liu Dingmin , Huang Pengcheng , Wu Fang-Ying
Published: April 2022

Schematic of colorimetric detection of tetracyclines based on dual regulation of gold nanoparticle (AuNP) aggregation and in situ silver metallization utilizing the catalytic properties of AuNPs and aptamer-target specific interaction.
A dual-mechanism-driven electrochemiluminescence aptasensor for sensitive detection of β-amyloid peptides
Authors: Chen Zixuan , Li Yinan , Qin Haixin , Yang Xiaoyan , Cao Wei
Published: April 2022

β-Amyloid (Aβ) peptides can bind both Cu2+ and heme cofactors simultaneously to form heme–Cu2+–Aβ complexes, which are proposed to generate toxic partially reduced oxygen species (PROS, e.g., H2O2) and play a vital role in Alzheimer's disease (AD).
Basic-to-acidic reversible pH switching with a merocyanine photoacid
Authors: Wimberger Laura , Andréasson Joakim , Beves Jonathon E.
Published: April 2022

Visible-light photoswitching of a merocyanine photoacid causes reversible pH changes from basic (pH 8.3) to acidic (pH 5.2) environments.
DMSO-assisted environmentally benign synthesis of benzo[c]-chromeno[4,3,2-gh]phenanthridines by remote oxidative hetero cross-coupling cyclization and aromatization reaction
Authors: Yashmin Sabina , Ali Rashid , Mondal Santa , Khan Abu Taleb
Published: April 2022

Synthesis of benzo[c]chromeno[4,3,2-gh]phenanthridines is accomplished by DMSO assisted oxidative hetero cross-coupling cyclization, and aromatization, through in situ generated o-quinone methide intermediate and sequential pericyclic reactions.
Hydrogen sulphide-triggered theranostic prodrugs based on the dynamic chemistry of tetrazines
Authors: Perretti Marcelle D. , Pérez-Pérez Yaiza , Soler-Carracedo Kevin , Martín-Encinas Endika , Alonso Concepción , Scoccia Jimena , Carrillo Romen
Published: April 2022

A novel kind of controlled delivery triggered by hydrogen sulfide has been developed. It is based on the dynamic chemistry of tetrazines, and it allows selective dual release in colon cancer cells.
Effect of substituents in novel bioactive tavaborole derivatives on the intermolecular interaction hierarchy
Authors: Dąbrowska Anna M. , Adamczyk-Woźniak Agnieszka , Madura Izabela D.
Published: April 2022

Tavaborole, a molecule based on the benzoxaborole scaffold, is an effective antifungal drug marketed under the Kerydin® trademark.
Protein dynamics of human serum albumin at hypothermic temperatures investigated by temperature jump
Authors: Yang Chih-Tsun , Chu Li-Kang
Published: April 2022

Revealing the relationship between the energetics of protein dynamics and apparent functioning of human serum albumin at the molecular level.
Excluded volume interactions and phase stability in mixtures of hard spheres and hard rods
Authors: Opdam Joeri , Gandhi Poshika , Kuhnhold Anja , Schilling Tanja , Tuinier Remco
Published: April 2022

Phase behaviour of binary rod/sphere mixtures: Verification of a novel free volume theory approach with Monte Carlo simulations.
Metal dimers embedded vertically in defect-graphene as gas sensors: a first-principles study
Authors: Yu Linke , Li Fengyu
Published: April 2022

Unprecedented metal dimers embedded symmetrically and vertically in defect-graphene were revealed to be promising gas sensors.
A stable silylborane with diminished boron Lewis acidity
Authors: Yoshida Hiroto , Izumi Yuki , Hiraoka Yuta , Nakanishi Kazuki , Nakamoto Masaaki , Hatano Sayaka , Abe Manabu
Published: April 2022

A highly stable, air-resistant silylborane containing a PhMe2Si moiety, whose boron Lewis acidity was diminished, was synthesized.
Catalytic production of long-chain hydrocarbons suitable for jet-fuel use from fermentation-derived oxygenates
Authors: Doménech Pablo , Pogrebnyakov Ivan , Nielsen Alex T. , Riisager Anders
Published: April 2022

Heterogeneous catalytic technology facilitates the production of sustainable aviation fuels from biomass via fermentation-derived oxygenates.
Exponential magnetophoretic gradient for the direct isolation of basophils from whole blood in a microfluidic system
Authors: Castaño Nicolas , Kim Sungu , Martin Adrian M. , Galli Stephen J. , Nadeau Kari C. , Tang Sindy K. Y.
Published: April 2022

We developed a microfluidic platform for rapid immunomagnetic isolation of basophils directly from whole blood. Our 3D printed magnetic separation device imparts an exponentially increasing magnetic force field to remove tagged non-basophils.
Actuated 3D microgels for single cell mechanobiology
Authors: Özkale Berna , Lou Junzhe , Özelçi Ece , Elosegui-Artola Alberto , Tringides Christina M. , Mao Angelo S. , Sakar Mahmut Selman , Mooney David J.
Published: April 2022

A mechanically active microgel platform for single cell mechanobiology is presented. Optically triggered nanoactuators generate isotropic compression in 3D microgels, leading to reversible and mechanosensitive calcium signaling in encapsulated MSCs.
The investigation of CdS-quantum-dot-sensitized Ag-deposited TiO2 NRAs in photoelectrochemical hydrogen production
Authors: Tezcan Fatih , Ahmad Abrar , Yerlikaya Gurbet , Zia-ur-Rehman  , Paksoy Halime , Kardaş Gülfeza
Published: April 2022

The synthesis of CdS/Ag/TiO2 for photoelectrochemical hydrogen production was carried out using electrochemical deposition and the SILAR method.
A green polyol approach for the synthesis of Cu2O NPs adhered on graphene oxide: a robust and efficient catalyst for 1,2,4-triazole and imidazo[1,2-a]pyridine synthesis
Authors: Kujur Shelly , Verma Shruti , Kumar Akash , Sharma Richa , Pathak Devendra Deo
Published: April 2022

Cu2O NPs immobilized on graphene oxide are used as a heterogeneous catalyst for the synthesis of a series of 1,2,4-triazoles and imidazo[1,2-a]pyridines under solvent-free conditions.
A high-density nickel–cobalt alloy embedded in nitrogen-doped carbon nanosheets for the hydrogen evolution reaction
Authors: Hu Lihua , Shi Jialing , Peng Zhiguang , Zheng Zefeng , Dong Huafeng , Wang Tiejun
Published: April 2022

A high-density nickel–cobalt alloy embedded in a nitrogen-doped carbon nanosheet structure provides sufficient gas transport for plentiful H2 bubbles that accelerate mass transfer, resulting in a higher HER activity than 20% Pt/C at a high current density.
A simple iodine–DMSO-promoted multicomponent reaction for the synthesis of 2,4-disubstituted dihydrotriazole-3-ones
Authors: Liao Hui , Huang Zesheng , Zhu Qiuhua
Published: April 2022

A series of 2,4-disubstituted 1,2,4-triazole-3-ones 4 were synthesized via an iodine–DMSO-promoted multicomponent reaction of formaldehyde 1, amines 2 and hydrazines 3 in moderate yields.
Base-promoted synthesis of diarylsulfones from sulfonyl hydrazines and diaryliodonium salts
Authors: Gong Bozhen , Zhu Haibo , Yang Liu , Wang Haifeng , Fan Qiangwen , Xie Zongbo , Le Zhanggao
Published: April 2022

An efficient transition-metal-free methodology for the conversion of a broad range of sulfonyl hydrazines with symmetrical and unsymmetrical diaryliodonium salts into the corresponding diaryl sulfones has been established under mild conditions.
Electrochemical oxidative selenocyclization of olefinic amides towards the synthesis of iminoisobenzofurans
Authors: Li Hao , Lu Fangling , Xu Jie , Hu Jianguo , Alhumade Hesham , Lu Lijun , Lei Aiwen
Published: April 2022

We introduced an electrochemical oxidative radical cascade cyclization of olefinic amides and diselenides without a transition-metal catalyst and external oxidant. This selenocyclization reaction provided a facile method to construct C–Se and C–O bonds in one step.
Mechanically robust triboelectric nanogenerator with a shear thickening fluid for impact monitoring
Authors: Yun Seong-Yun , Tcho Il-Woong , Kim Weon-Guk , Kim Do-Wan , Son Joon-Ha , Lee Sang-Won , Choi Yang-Kyu
Published: April 2022

A triboelectric nanogenerator using a shear thickening fluid is fabricated. Its Janus-face behaviors are analyzed by comparative experiments. With its enhanced mechanical robustness and durability, an impact monitoring system is developed.
Insight into the preponderant role of the lattice size in Sn-based colusites for promoting a high power factor
Authors: Kamińska Paulina , Bourgès Cédric , Chetty Raju , Gutiérrez-Del-Río Daniel , Śpiewak Piotr , Święszkowski Wojciech , Nishimura Toshiyuki , Mori Takao
Published: April 2022

We investigated the feasibility of the co-doping effect of zinc and chromium for copper and vanadium substitution, respectively, and reported the first successful Cr incorporation within the bulk Sn-based colusite structure.
A high-performance GelMA–GelMA homogeneous double-network hydrogel assisted by 3D printing
Authors: Dong Yipeng , Zhang Mingshan , Han Daobo , Deng Zhichao , Cao Xuewei , Tian Jianguo , Ye Qing
Published: April 2022

A GelMA–GelMA (G–G) homogeneous double-network hydrogel was constructed assisted by DLP 3D printing to obtain excellent performance especially mechanical properties.
The Effects of Intensive Voice Treatment in Mandarin Speakers With Parkinson's Disease: Acoustic and Perceptual Findings
Authors: Hsu Sih-Chiao , Jiao Yishan , Berisha Visar , McAuliffe Megan J. , Lin Peiyi , Wu Ruey-Meei , Cheng Shih-Jung , Levy Erika S.
Published: April 2022

Purpose:

This study investigated the effects of intensive voice treatment on subjective and objective measures of speech production in Mandarin speakers with hypokinetic dysarthria.

Method:

Nine Mandarin speakers with hypokinetic dysarthria due to Parkinson's disease received 4 weeks of intensive voice treatment (4 × 60 min per week). The speakers were recorded reading a passage before treatment (PRE), immediately after treatment (POST), and at 6-month follow-up (FU). Listeners (
n
= 15) rated relative ease of understanding (EOU) of paired speech samples on a visual analogue scale. Acoustic analyses were performed. Changes in EOU, vocal intensity, global and local fundamental frequency (
f
o
) variation, speech rate, and acoustic vowel space area (VSA) were examined.

Results:

Increases were found in EOU and vocal intensity from PRE to POST and from PRE to FU, with no change found from POST to FU. Speech rate increased from PRE to POST, with limited evidence of an increase from PRE to FU and no change from POST to FU. No changes in global or local
f
o
variation or in VSA were found.

Conclusions:

Intensive voice treatment shows promise for improving speech production in Mandarin speakers with hypokinetic dysarthria. Vocal intensity, speech rate, and, crucially, intelligibility, may improve for up to 6 months posttreatment. In contrast,
f
o
variation and VSA may not increase following the treatment.

Supplemental Material:

https://doi.org/10.23641/asha.19529017
Voice and Speech Changes in Transmasculine Individuals Following Circumlaryngeal Massage and Laryngeal Reposturing
Authors: Dahl Kimberly L. , François Felicia A. , Buckley Daniel P. , Stepp Cara E.
Published: April 2022

Purpose:

The purpose of this study was to measure the short-term effects of circumlaryngeal massage and laryngeal reposturing on acoustic and perceptual characteristics of voice in transmasculine individuals.

Method:

Fifteen transmasculine individuals underwent one session of sequential circumlaryngeal massage and laryngeal reposturing with a speech-language pathologist. Voice recordings were collected at three time points—baseline, postmassage, and postreposturing. Fundamental frequency (fo), formant frequencies, and relative fundamental frequency (RFF; an acoustic correlate of laryngeal tension) were measured. Estimates of vocal tract length (VTL) were derived from formant frequencies. Twelve listeners rated the perceived masculinity of participants' voices at each time point. Repeated-measures analyses of variance measured the effect of time point onfo, estimated VTL, RFF, and perceived voice masculinity. Significant effects were evaluated with post hoc Tukey's tests.

Results:

Between baseline and end of the session,fodecreased, VTL increased, and participant voices were perceived as more masculine, all with statistically significant differences. RFF did not differ significantly at any time point. Outcomes were highly variable at the individual level.

Conclusion:

Circumlaryngeal massage and laryngeal reposturing have short-term effects on select acoustic (fo, estimated VTL) and perceptual characteristics (listener-assigned voice masculinity) of voice in transmasculine individuals.

Supplemental Material:

https://doi.org/10.23641/asha.19529299
Daily Phonotrauma Index: An Objective Indicator of Large Differences in Self-Reported Vocal Status in the Daily Life of Females With Phonotraumatic Vocal Hyperfunction
Authors: Nudelman Charles J. , Ortiz Andrew J. , Fox Annie B. , Mehta Daryush D. , Hillman Robert E. , Van Stan Jarrad H.
Published: April 2022

Purpose:

The purpose of this study is to evaluate if the Daily Phonotrauma Index (DPI) can quantitatively discriminate large differences in overall vocal status in the daily life of patients with phonotraumatic vocal hyperfunction (PVH).

Method:

For 1–4 weeks, 23 females with PVH wore an ambulatory voice monitor and answered three vocal status questions (i.e., difficulty producing soft, high-pitched phonation; discomfort; and fatigue) at the beginning, at 5-hr intervals, and the end of each day. DPI values were obtained for each patient's time periods of worst and best self-rated vocal status, and data for the group were analyzed for significant changes using a linear mixed-effects regression model.

Results:

The DPI was significantly lower during periods self-rated as “best vocal status” compared to during periods self-rated as “worst vocal status” (mean difference in DPI = 0.53) with a medium-to-large effect size (Cohen's
d
= −0.68).

Conclusions:

In a group of patients with phonotraumatic lesions, the DPI indicated lower potential for phonotrauma during time periods of better vocal status compared to time periods of worse vocal status. Assuming that a large portion of variance in vocal status for patients with PVH is associated with the extent to which voicing is phonotraumatic, these results support the validity of obtaining estimates of DPI for much shorter time periods (i.e., an estimate every 2 min of voicing) than previous studies (i.e., a single estimate for the entire day or week). Future work can investigate the DPI's use for in-clinic assessment/treatment and ambulatory biofeedback and can gain further insights into phonatory mechanisms that underlie DPI via comparisons with other physiologically relevant measures and computational vocal fold modeling.
Differential space time media‐based modulation system
Authors: Zou Hongliang , Quan Daying , Jin Xiaoping , Zhou Yueru
Published: April 2022

Differential spatial modulation (DSM) is a multi‐antenna differential technology with low power consumption and no demand of channel estimation. It is suitable for communication systems that have fast migration velocity and high requirements for both power consumption and complexity. However, due to the sparse structure and the requirements of differential coding, the spectral efficiency is limited. Therefore, media‐based modulation (MBM) technology is introduced into differential system in this work to improve the spectral. A differential space time media‐based modulation (DSTMBM) system is proposed. While retaining the inherent advantages of the DSM, the additional bits are transmitted through the radio frequency (RF) mirrors in DSTMBM. Unlike traditional DSM, the transmit antenna of DSTMBM system can be activated multiple times. In addition, a theoretical performance is derived, and a low‐complexity (LC) detection algorithm is adopted. Simulation results show that the DSTMBM system has a performance advantage of about 4.5 dB at a high transmission rate compared to traditional DSM systems. Monte Carlo simulation matches the theoretical performance in a wide range. Meanwhile, the LC detection algorithm reduces the complexity by 2–3 orders of magnitude without the bit error rate (BER) performance loss.
Hardware routed quantum key distribution networks
Authors: Singal Ansh , Iyengar Sundaraja Sitharam , Kumar Latesh , Madni Azad M.
Published: April 2022

Quantum communication networks pose immense potential for revolutionising secure communications for several applications such as banking, defence, etc. The majority literature on quantum networks deals with the problems of networking and resource allocation using Software Defined Networks (SDNs). SDNs, however, introduce several issues, such as app manipulation attacks and scalability issues. We propose a novel scheme of implementing quantum communication networks that are hardware routed rather than software defined by labelling qubit photons using laser communications. We provide a comprehensive implementation of the new scheme and propose two novel algorithms—Bandwidth sharing and Equitable bandwidth sharing to implement the hardware routed quantum network. The algorithms result in a key rate increase of 118% and improved network resource utilization of 147% as compared to the First Come First Serve algorithm.
Submillimeter wave spectroscopy and astronomical search for 1-propanimine
Authors: Margulès L. , Remijan A. , Belloche A. , Motiyenko R. A. , McGuire B. A. , Xue C. , Müller H. S. P. , Garrod R. T. , Menten K. M. , Guillemin J.-C.
Published: April 2022

Context.Methanimine, CH2NH, and ethanimine, CH3CHNH, were both detected in the interstellar medium (ISM), the former in the 1970s and the latter nearly a decade ago. By analogy with nitriles, for which hydrogen cyanide, acetonitrile, and ethyl cyanide are the most abundant, n-propanimine was suggested as a candidate for detection in the ISM.

Aims.To date, no measurements of the rotational spectrum of 1-propanimine have been made. We present measurements and an analysis of its spectrum in the millimeter- and submillimeter-wave domain in order to provide an accurate prediction that is required to search for this molecule in the ISM.

Methods.The rotational spectrum of propanimine was investigated from 150 to 470 GHz. Watson’s asymmetric top Hamiltonian in theIrrepresentation and S reduction was used for the analysis. The new prediction allowed us to search for 1-propanimine toward the high-mass star forming region Sagittarius B2(N), the dark molecular cloud TMC-1, as well as a sample of low-mass protostellar objects. These sources were observed with the Atacama Large Millimeter/submillimeter Array, the Green Bank Telescope, or the IRAM 30 m telescope.

Results.A total of 585 and 296 transitions of the E and Z-1-propanimine, respectively, were newly assigned and fitted in the laboratory spectra recorded up to 470 GHz. Quantum numbers up toJ= 73 andKa= 18 were reached for theEisomer andJ= 56 andKa= 17 for the Z isomer. We report the nondetection of 1-propanimine toward all astronomical sources investigated in this work. We find in particular that 1-propanimine is at least 20 times less abundant than methanimine in the envelope of the high-mass star forming region Sagittarius B2(N).

Conclusions.The accurate spectroscopic prediction of its spectrum provided in this work will allow astronomers to continue the search for 1-propanimine in the ISM.
An ultraweak space-time variational formulation for the wave equation: Analysis and efficient numerical solution
Authors: Henning Julian , Palitta Davide , Simoncini Valeria , Urban Karsten
Published: April 2022

We introduce an ultraweak space-time variational formulation for the wave equation, prove its well-posedness (even in the case of minimal regularity) and optimal inf-sup stability. Then, we introduce a tensor product-style space-time Petrov–Galerkin discretization with optimal discrete inf-sup stability, obtained by a non-standard definition of the trial space. As a consequence, the numerical approximation error is equal to the residual, which is particularly useful for a posteriori error estimation. For the arising discrete linear systems in space and time, we introduce efficient numerical solvers that appropriately exploit the equation structure, either at the preconditioning level or in the approximation phase by using a tailored Galerkin projection. This Galerkin method shows competitive behavior concerning wall-clock time, accuracy and memory as compared with a standard time-stepping method in particular in low regularity cases. Numerical experiments with a 3D (in space) wave equation illustrate our findings.
Syphilisinfektion im HNO-Bereich
Authors: Seuthe Inga Marte Charlott , Eichhorn Sabine , Kim Jonghui , van Ackeren Konstantin , Park Jonas Jae-Hyun , Dazert Stefan , Klespe Kai-Christian
Published: April 2022

Die Anzahl der gemeldeten Syphilis-Fälle steigt seit Jahren an. Die sexuell übertragbare Erkrankung wird durch die Spirochäte Treponema pallidum Subspezies pallidum verursacht und verläuft hierbei in verschiedenen Stadien. In allen Stadien können hierbei Symptome im HNO-Bereich auftreten. Hierdurch ist bei passenden Symptomen eine Syphilis-Infektion als Differenzialdiagnose vom HNO-Arzt stets zu bedenken. So ist bei zunehmendem oralem Geschlechtsverkehr der Primäraffekt/harter Schanker zunehmend häufig im Mundraum zu beobachten. Zudem können Symptome nicht nur im Mundraum, sondern auch im Bereich des Ohrs, der Nase, des Larynx sowie auch zervikal und fazial auftreten. Die Diagnose wird hierbei über den direkten Erregernachweis oder über einen serologischen Nachweis gesichert. Die Spirochäte ist nicht kultivierbar. Der therapeutische Goldstandard ist die Gabe von Benzathin-Penicillin G oder Procain-Penicillin G. Als Alternative stehen Doxycyclin, Makrolide oder Ceftriaxon zur Verfügung. Bei einer Innenohr- oder Hirnnervenbeteiligung ist die zusätzliche Gabe eines Glukokortikoids zu empfehlen. Vor Durchführung der antibiotischen Therapie ist der Patient über die Möglichkeit einer Jarisch-Herxheimer-Reaktion aufzuklären. Bei einer Syphilis-Infektion ist stets eine kollegiale Zusammenarbeit mit den Venerologen zu empfehlen, sodass eine effektive und umfassende Diagnostik und Therapie erfolgen kann.
KHZG-Mittel richtig Einsetzen: Cybersicherheit für Nicht-KRITIS-Häuser
Authors: Asma Jorg , Gross Benedict
Published: April 2022

Seit Jahresbeginn unterliegen alle Krankenhäuser verschärften gesetzlichen Anforderungen an die Informationssicherheit. Als Referenz für die Absicherung gilt der Standard B3S für die Gesundheitsversorgung im Krankenhaus. Die Umsetzung birgt Herausforderungen und Fallstricke für die Krankenhausgeschäftsführung.
Einwurf aus der Branche: Schluss mit dem Kontrollwahn
Authors: Schulte Barbara
Published: April 2022

Der wirksamste Hebel gegen den aktuellen Fachkräftemangel im Gesundheitswesen ist weniger Bürokratie.
A critical evaluation of rationalist IR in the analysis of informal institutions
Authors: Cooper Andrew F.
Published: April 2022

This article has two major inter-connected objectives about the ascendancy of informal international institutions on a global basis. The first objective is to highlight the extended scope of this phenomenon. The second objective of this article evaluates how the mainstream International Relations (IR) literature has treated the cascading wave of informal institutions. With this expansion in mind, the focus is on a critical evaluation of the rationalist institutionalist literature generally and rational design scholarship more specifically. This scholarship possesses some considerable foundational advantages. At the same time several important deficiencies stand out. First, in terms of participation, the scholarship remains excessively US-centric. Secondly, in terms of projection, the rationalist institutionalist literature lacks both historical context and an anticipatory component. Thirdly, in terms of the ‘living personality’ constitutive of informal institutions, the mode of analysis lacks nuance. Notwithstanding its claims of consistency with respect to the logic of institutionalism, the rationalist institutionalist literature is highly uneven in terms of its analysis about the nature of informal institutions. The most consistent component throughout rationalist institutionalist literature is what type of informal institutionalism is left out. Informal institutionalism is recognized to be on the ascendancy. But the core manifestation of informal institutionalism—state-based plurilateralism—is neglected in the analysis.
Measurement of helicity flux density using the eddy-current diagnostic system in Keda Torus eXperiment device
Authors: Chen Zheng , Li Hong , Yolbarsop Adil , Zhang Yuan , Yan Wentan , Rao Xianhao , Tao Zhen , Mao Wenzhe , Wei Zian , Liu Zixi , Zhou Chu , Liu Adi , Lan Tao , Xie Jinlin , Zhou Haiyang , Wen Xiaohui , Wang Hai , Zhuang Ge , Xiao Chijin , Ding Weixing , Liu Wandong
Published: April 2022

The flux of magnetic helicity characterizes how the topology of a magnetic field changes and helicity and its transport play essential roles in plasma equilibrium and instabilities in the reversed-field pinch (RFP) device configuration. Used to suppress magnetohydrodynamic instabilities effectively, the stabilizing conducting shell located at the boundary of an RFP device is always characterized by an eddy-current distribution that evolves rapidly with time. After measuring and analyzing the eddy currents on this stabilizing shell during tokamak discharges in the Keda Torus eXperiment device, the distributions of multiple physical quantities on the shell are obtained, including the magnetic fields, eddy currents, and electric fields. An experimental technique for measuring helicity flux density is demonstrated, combined with eddy-current diagnosis and these physical vectors on the boundary. How the magnetic and current helicity flux densities evolve is given by a feasible mathematical analysis, and data suggest that the plasma mediates both the generation and transport of magnetic helicity during the discharge. The experimental results of the distribution of the magnetic helicity flux densities (MHFDs) due to the instability on the boundary are given, and the average of these MHFDs over the whole boundary surface is far less than the maximum value of the MHFDs. In addition, the results of current helicity flux densities on the boundary are also presented.
Strong reconnection electric fields in shock-driven turbulence
Authors: Bessho N. , Chen L.-J. , Stawarz J. E. , Wang S. , Hesse M. , Wilson L. B. , Ng J.
Published: April 2022

Turbulent magnetic reconnection in a quasi-parallel shock under parameters relevant to the Earth's bow shock is investigated by means of a two-dimensional particle-in-cell simulation. The addressed aspects include the reconnection electric field, the reconnection rate, and the electron and the ion outflow speeds. In the shock transition region, many current sheets are generated in shock-driven turbulence, and electron-only reconnection and reconnection where both ions and electrons are involved can occur in those current sheets. The electron outflow speed in electron-only reconnection shows a positive correlation with the theoretical speed, which is close to the local electron Alfvén speed, and a strong convection electric field is generated by the large electron outflow. As a result, the reconnection electric field becomes much larger than those in the standard magnetopause or magnetotail reconnection. In shock-driven reconnection that involves ion dynamics, both electron outflows and ion outflows can reach of the order of 10 times the Alfvén speed in the X-line rest frame, leading to a reconnection electric field the same order as that in electron-only reconnection. An electron-only reconnection event observed by the magnetospheric multiscale mission downstream of a quasi-parallel shock is qualitatively similar to those in the simulation and shows that the outflow speed reaches approximately half the local electron Alfvén speed, supporting the simulation prediction.
One-kilojoule pulsed-power generator for laboratory space sciences
Authors: Chang Po-Yu , Lin Yen-Cheng , Kuo Ming-Hsiang , Du Cheng-Han , Hsieh Chih-Jui , Huang Mei-Feng , Jheng Ming-Cheng , Liu Jia-Kai , Yang Sheng-Hua , Yeh I-Lin , Wessel Frank J.
Published: April 2022

This paper reports on the assembly of a compact, low-cost, pulsed-power facility used for plasma studies. The construction uses two modules placed on opposite sides of the test chamber to minimize the system impedance and improve access to test samples. The stored energy is 1  kJ with a peak current of 135  kA and a 1592  ns quarter-period time. Up until now, an imploding conical-wire array has been studied by using time-integrated (visible) imaging, and time-resolved laser imaging, providing a measure of the plasma jet speed in the range of 170  km/s. Our future plans will continue to investigate high-energy-density plasmas that are relevant to the space environment, fusion, and spectroscopy.
Dynamic response of polycrystalline high energetic systems: Constitutive modeling and application to impact
Authors: Revil-Baudard Benoit , Cazacu Oana
Published: April 2022

This paper presents a new polycrystalline model and Lagrangian computational framework for describing the large-scale thermo-mechanical response of energetic materials under dynamic loadings. In our multi-scale computational polycrystalline framework, at the grain level, the elastic response is modeled using an anisotropic Hooke's law, while the plastic behavior is described with a recently developed quadratic anisotropic single-crystal model that accounts for the intrinsic symmetries associated with the lattice of the constituent crystals. The orientation, plastic strains, and stresses in the individual grains are continuously updated, so the predicted macroscopic scale response takes into account the evolution of the thermo-mechanical state at the meso-scale. First, we illustrate the polycrystalline model capabilities by simulating the response of a pentaerythritol tetranitrate (PETN) polycrystalline high energetic system when subjected to dynamic compression. It is shown that there are strong differences in temperature and stresses between the constituent grains, depending on their relative orientation with respect to the wave direction. Moreover, it is shown that the rise in temperature in certain grains may be well in excess of the macroscopic value. We also present 3D finite element simulations of the impact of a penetrator made of a high-strength steel containing the same polycrystalline PETN system. Insights into the complex interactions between the energetic system and the metallic casing material are provided. Furthermore, it is shown that if the crystallinity is neglected, the predicted temperature rise and the extent of the zone of maximum heating in the energetic system during the impact event differ noticeably from those obtained with our polycrystalline model, which accounts for the crystallinity of the PETN material and the anisotropy in the plastic flow of its constituent crystals.
Mesoporous silica-encaged ultrafine ceria–nickel hydroxide nanocatalysts for solar thermochemical dry methane reforming
Authors: Wells Vivienne , Riaz Asim , Sun Qiming , Li Xian , Yan Ning , Wang Chi-Hwa , Lipiński Wojciech
Published: April 2022

Reforming of methane to produce synthesis gas for the Fischer–Tropsch process provides an alternative to fossil fuels. Silica-encaged ceria–nickel hydroxide catalysts were produced by an in situ synthesis method to obtain ultrafine bimetallic species dispersed evenly within the mesoporous silica matrix. Dry reforming and reduction-oxidation cycling was undertaken with the materials. Catalysts with high content of nickel showed good activity during dry reforming, with conversions rates close to equilibrium in equimolar conditions. Insignificant deactivation of the catalysts was observed over 5 h and 50 h of reaction at 900 °C. Syngas production via reduction–oxidation cycling was shown to be insignificant as compared to continuous catalytic reforming.
Epitaxial growth of β-Ga2O3 on SrTiO3 (001) and SrTiO3-buffered Si (001) substrates by plasma-assisted molecular beam epitaxy
Authors: Hadamek Tobias , Posadas Agham B. , Al-Quaiti Fatima , Smith David J. , McCartney Martha R. , Dombrowski Eric , Demkov Alexander A.
Published: April 2022

Thin Ga2O3 films were deposited by plasma-assisted molecular beam epitaxy on SrTiO3 (001) and SrTiO3-buffered Si (001) substrates. Examination using reflection-high-energy electron diffraction, x-ray diffraction, and transmission electron microscopy shows a consistent picture of (100)- and (1¯12)-oriented β-Ga2O3 grains. The structural alignments are β-Ga2O3[010] || STO ⟨110⟩ and β-Ga2O3 [021] || STO ⟨100⟩, respectively, each with four in-plane rotational domain variants. Successful integration of epitaxial β-Ga2O3 with Si could enable major opportunities for monolithically integrated Ga2O3 technology by serving as a high-quality seed layer for further epitaxial growth.
Elastic properties of Yukawa crystals
Authors: Kozhberov A. A.
Published: April 2022

We study elastic properties of solid Yukawa systems. Elastic moduli and effective shear modulus of body-centered cubic and face-centered cubic lattices are obtained from electrostatic energies of deformed crystals. For the bcc lattice, our results are well consistent with previous calculations and improve them, while results for the fcc lattice are mostly new. We have also obtained an analytical expression of the elastic moduli for the weak polarization and constructed a convenient approximation for the higher polarization.
Neutral gas and plasma shielding (NGPS) model and cross-field motion of ablated material for hydrogen–neon mixed pellet injection
Authors: Matsuyama Akinobu
Published: April 2022

A neutral-gas and plasma shielding (NGPS) model is applied for cryogenic hydrogen–neon mixed pellet injection used for the mitigation of tokamak disruptions. The NGPS model is useful to evaluate the characteristics of ionized plasmoid (size, density, temperature, and radiation), while reproducing the scaling of the neutral gas shielding model. It is found that even if one takes into account the optical thickness for radiation, the energy loss due to line radiation associated with neon is strong enough to limit the temperature and the pressure of the ionized plasmoid for pure neon or hydrogen–neon mixed pellets in the early phase of the material homogenization. Consequently, the ionized plasmoid of the neon mixed pellets is expected to homogenize along the magnetic field line where the ablated material is released—without significantly making the cross-field drift motion—as compared to pure hydrogen pellets.
A single methyl group drastically changes urea’s hydration dynamics
Authors: Marekha Bogdan A. , Hunger Johannes
Published: April 2022

The amphiphilicity and denaturation efficiency of urea can be tuned via alkylation. Although the interaction of alkylureas with water and proteins has been studied in detail, hydration of 1-methylurea has remained elusive, precluding the isolation of the effect of an individual methyl group. Here, we study water dynamics in the hydration shell of 1-methylurea (1-MU) using infrared absorption and ultrafast infrared spectroscopies. We find that 1-MU hardly affects the hydrogen-bond distribution of water as probed by the OD stretching vibration of HOD molecules. Polarization resolved infrared pump–probe experiments reveal that 1-MU slows down the rotational dynamics of up to 3 water molecules in its hydration shell. A comparison to earlier results for other alkylureas suggests that further alkylation does not necessarily slow down the rotational dynamics of additional water molecules. Two-dimensional infrared experiments show that 1-MU markedly slows down the hydrogen-bond fluctuation dynamics of water, yet similar to what has been found for urea and dimethylureas. Remarkably, (alkyl-)ureas that share a similar effect on water’s hydrogen-bond fluctuation dynamics have a similar (modest) protein denaturation tendency. As such, not only the hydrophobicity but also hydration of hydrophilic fragments of alkylureas may be relevant to explain their function toward biomolecules.
Noble-gas atoms characterized by hyperfine frequency shift of lithium atom
Authors: Ishikawa Kiyoshi
Published: April 2022

We report an experimental and theoretical study on the shift of the hyperfine splitting frequency of ground-state Li atoms in noble gases, He, Ne, Ar, and Xe. The frequency shift is due to the change in the electron-spin density at the Li nuclei induced by collisions to the noble-gas atoms. The electron density is calculated along the interatomic distance in a pseudopotential and a dispersion potential. Based on the measured and the calculated frequency shifts, we find the importance of attractive force in collisions to helium as well as heavy noble-gas atoms. Taking advantage of the simple energy structure of the Li atom, we obtain the s wave scattering length for free electrons on noble-gas atoms by using the hyperfine splitting frequency as a precise measure.
Non-reciprocal diplexer and power combiner/divider from topological cavities with both splitting and combining functions
Authors: Dinh Minh Quang , Le Minh Thuy
Published: April 2022

Multiplexers and power combiners/dividers are crucial in many applications of electromagnetic waves including microwave and terahertz communication. Full-duplex communication requires the separation of transmitted and received signals; thus, non-reciprocal multiplexers and power combiners/dividers are very essential. In this work, we present and numerically study a design concept for such non-reciprocal circuits from topological cavities. First, a quad-port circulator is made from a topological cavity and two trivial waveguides, which effectively operates as a non-reciprocal band-pass filter. Then, by parallelly connecting multiple circulators together, topological diplexers and power combiners/dividers are formed. These circuits are non-reciprocal due to the nature of photonic topological insulators, yet unlike the previously proposed non-reciprocal multiplexers or power combiners/dividers, they can both split and combine multiple frequencies or multiple power flows. The topological nature of the proposed circuits also makes them robust to any fabrication error and suitable for practical full-duplex communication applications.
Ultrafast excitation quenching by the oxidized photosystem II reaction center
Authors: Akhtar Parveen , Sipka Gábor , Han Wenhui , Li Xingyue , Han Guangye , Shen Jian-Ren , Garab Győző , Tan Howe-Siang , Lambrev Petar H.
Published: April 2022

Photosystem II (PSII) is the pigment–protein complex driving the photoinduced oxidation of water and reduction of plastoquinone in all oxygenic photosynthetic organisms. Excitations in the antenna chlorophylls are photochemically trapped in the reaction center (RC) producing the chlorophyll–pheophytin radical ion pair P+ Pheo−. When electron donation from water is inhibited, the oxidized RC chlorophyll P+ acts as an excitation quencher, but knowledge on the kinetics of quenching is limited. Here, we used femtosecond transient absorption spectroscopy to compare the excitation dynamics of PSII with neutral and oxidized RC (P+). We find that equilibration in the core antenna has a major lifetime of about 300 fs, irrespective of the RC redox state. Two-dimensional electronic spectroscopy revealed additional slower energy equilibration occurring on timescales of 3–5 ps, concurrent with excitation trapping. The kinetics of PSII with open RC can be described well with previously proposed models according to which the radical pair P+ Pheo− is populated with a main lifetime of about 40 ps, which is primarily determined by energy transfer between the core antenna and the RC chlorophylls. Yet, in PSII with oxidized RC (P+), fast excitation quenching was observed with decay lifetimes as short as 3 ps and an average decay lifetime of about 90 ps, which is shorter than the excited-state lifetime of PSII with open RC. The underlying mechanism of this extremely fast quenching prompts further investigation.
Zigzag phosphorene antidot nanoribbons (ZPANRs) for the detection of nucleobases: A DFT based study
Authors: Carmel Santhia , Subramanian Sriram , Tan Michael Loong Peng , Alias Nurul Ezaila , Riyadi Munawar Agus , Endro Suseno Jatmiko , Rathinam Ramesh , Bhattacharyya Arkaprava
Published: April 2022

In this work, we have investigated the potential of zigzag phosphorene antidot nanoribbons (ZPANRs) for biosensing applications. ZPANRs were created from the optimized structures of phosphorene nanoribbons by using a density functional theory tool. Utilizing the generalized gradient approximation half method for improving the accuracy of calculations, we have studied the electronic and sensing behavior of ZPANRs based devices wherein nucleobases were inserted into the device. We have compared the device performance of ZPANRs with and without nucleobases and found that using ZPANRs devices, we are able to identify different nucleobases with considerable sensitivity. In a quantitative manner, a max sensitivity of 45% is achieved while identifying adenine nucleobase using the ZPANRs based devices. From these simulation results, it is predicted that the ZPANR based two-terminal device can work as a possible biosensor.
Cooperative effects driving the multi-periodic dynamics of cyclically sheared amorphous solids
Authors: Szulc Asaf , Mungan Muhittin , Regev Ido
Published: April 2022

When subject to cyclic forcing, amorphous solids can reach periodic, repetitive states, where the system behaves plastically, but the particles return to their initial positions after one or more forcing cycles, where the latter response is called multi-periodic. It is known that plasticity in amorphous materials is mediated by local rearrangements called “soft spots” or “shear transformation zones.” Experiments and simulations indicate that soft spots can be modeled as hysteretic two-state entities interacting via quadrupolar displacement fields generated when they switch states and that these interactions can give rise to multi-periodic behavior. However, how interactions facilitate multi-periodicity is unknown. Here, we show, using a model of random interacting two-state systems and molecular dynamics simulations, that multi-periodicity arises from oscillations in the magnitudes of the switching field of soft spots, which cause soft spots to be active during some forcing cycles and idle during others. We demonstrate that these oscillations result from cooperative effects facilitated by the frustrated interactions between the soft spots. The presence of such mechanisms has implications for manipulating memory in frustrated hysteretic systems.
Dynamical anomalies and structural features of active Brownian particles characterized by two repulsive length scales
Authors: Martín-Roca José , Martinez Raúl , Martínez-Pedrero Fernando , Ramírez Jorge , Valeriani Chantal
Published: April 2022

In this work, we study a two-dimensional system composed by Active Brownian Particles (ABPs) interacting via a repulsive potential with two length scales—a soft shell and a hard core. Depending on the ratio between the strength of the soft shell barrier and the activity, we find two regimes: If this ratio is much larger or smaller than 1, the observed behavior is comparable with ABPs interacting via a single length scale potential. If this ratio is similar to 1, the two length scales are relevant for both structure and dynamical properties. On the structural side, when the system exhibits a motility induced phase separation, the dense phase is characterized by new and more complex structures compared with the hexatic phase observed in single length scale systems. From the dynamic analysis, we find, to our knowledge, the first manifestation of a dynamic heterogeneity in active particles, reminiscent of the glassy dynamics widely studied in passive colloids.
Manipulating electron-spin polarization using cysteine–DNA chiral conjugates
Authors: Pal Chittatosh , Majumder Subrata
Published: April 2022

The chiral molecules are potential generators of high spin-filters due to their inherent inversion asymmetric helical electric field. We report a controlled spin-selective transmission of electrons through self-assembled monolayers of 15 base-paired double-stranded deoxyribonucleic acid functionalized with two enantiomeric cysteine molecules on gold explored through the quantum mechanical tunneling effect. We observed a controlled spin polarization of 33% with dextro-cysteine, whereas a mere 8% was observed with levo-cysteine molecules using these functionalizations at room temperature. The manipulation of electron’s spin merely through such a small molecule could lead to significant advancement in the spin-dependent charge transport phenomena and related applications.
Effect of electromagnetic induction coil position on feeding effect in steel ingot
Authors: Liu Ningning , Xu Changjun , Lv Yan , Wang Tao , Wu Gang , Zhang Zhiqiang
Published: April 2022

The relationship between the feeding ability of the riser and the shrinkage and porosity is always a hot investigation topic, and the interior shrinkage and porosity of the ingot is the common defect met by industries. The work on the effect of Electromagnetic Feeding Riser (EFR) on ingot solidification is approached via the interpretative of the electromagnetic heat efficiency, temperature field, and Niyama criteria. The results show that the heating effect is better when the induction coil is at L = 0 mm and the heat efficiency rapidly reduces with the induction coil away from the riser, from the view of magnetic field. An obvious improvement in the solidification process is the application of EFR from the view of temperature field. Then, the Niyama criterion was defined as 1.1 through the experiment and simulation. Electromagnetic feeding starts to restrain the appearance of the shrinkage and porosity when L = 0 mm and D = 60 mm, where the effective Joule heat generated by the induction coil occupies about 75% of the energy dissipated in the riser solidification process, at least. The better feeding effect can be obtained at L = 0 mm and D = 40 mm in consideration of the thickness of the insulation board.
Experimental study of two-phase heat transfer of droplet impact on liquid film
Authors: Bao Minle , Wang Feng , Guo Yali , Gong Luyuan , Shen Shengqiang
Published: April 2022

Spray cooling is an effective heat transfer technique capable of handling high heat fluxes and temperatures. The study of droplet impact offers a simplified approach to understanding the fundamentals of spray cooling and elucidates the effects of droplet diameter and velocity. Experiments on a single-droplet impact on a thin liquid film with boiling bubbles are carried out in this study. Two-phase interface evolution is observed using high-speed video, and the heater surface temperature variation at the impact point following an impact is recorded and analyzed, which can be divided into the response stage, the recovery stage, the steady stage, and the slow recovery stage. Furthermore, a cooling factor based on the change in heater surface temperature is introduced to evaluate the cooling effect of droplet impact. Results show that the steady stage plays a significant role in the heater surface cooling process. Moreover, the maximum cooling factor increases appreciably with increasing droplet diameter and impact velocity.