bluuebunny/crossref_metadata_2025 huggingface dataset:
Phenanthrene[2]arene: synthesis and application as nonporous adaptive crystals in the separation of benzene from cyclohexane
Authors: Zeng Fei , Cheng Lu , Zhang Wei-Jun , Tang Lin-Li , Wang Xiao-Feng
Published: April 2022

Phenanthrene[2]arene 1 with excellent adsorption capacity for benzene was synthesized in high yield. Activated crystals of 1 have been successfully used to separate PhH from equimolar mixture of PhH and Cy and the purity of the PhH can reach 98.4%.
Review on synthesis, properties and multifarious therapeutic applications of nanostructured zirconia in dentistry
Authors: Bapat Ranjeet A. , Yang Ho Jan , Chaubal Tanay V. , Dharmadhikari Suyog , Abdulla Anshad Mohamed , Arora Suraj , Rawal Swati , Kesharwani Prashant
Published: April 2022

Amongst dental ceramics, nano zirconia (ZrNp) has shown exceptional developments in the field of dentistry in recent years.
Gelation phase diagrams of colloidal rod systems measured over a large composition space
Authors: He Shiqin , Caggioni Marco , Lindberg Seth , Schultz Kelly M.
Published: April 2022

Colloidal rod systems used as rheological modifiers are characterized over a large composition space with microrheology and bulk rheology. Phase diagrams are built that enable identification of compositions with desired properties eliminating trial-and-error experiments.
Band gap tunable quaternary PbxCd1−xS1−ySey quantum dot-sensitized solar cells with an efficiency of 9.24% under 1% sun
Authors: Boon-on Patsorn , Rajendran Raja , Yao Yueh-Ting , Lien Shang-Wei , Chang Tay-Rong , Lee Ming-Way
Published: April 2022

We present a new solar absorber material – quaternary PbxCd1−xS1−ySey quantum dots (QDs) – with a band gap Eg tunable over a broad range of 1.5–2.4 eV.
Objective and Subjective Benefit of Direct-to-Consumer Hearing Devices in Middle-Aged Adults
Authors: Helfer Karen S. , Mamo Sara K. , Clauss Michael , Dunn Lincoln
Published: April 2022

Purpose:

The purpose of this project was to assess subjective and objective benefit provided by several direct-to-consumer hearing devices for middle-aged adults. The primary goal of this study was to determine the extent to which this type of device can yield benefit when users are listening in a range of acoustic conditions, rather than to compare benefit among devices.

Method:

Participants (
M
age
= 58 years,
n
= 40) completed a speech perception task with and without one of four direct-to-consumer devices. Stimuli were presented with three types of maskers (steady-state noise, modulated noise, and competing talkers) at two different signal-to-noise ratios and two target levels. Participants also rated the effort required to complete the task with and without the devices and completed a short questionnaire about device comfort and perceived effectiveness.

Results:

The amount of objective benefit (in terms of speech recognition accuracy) varied among the four products, with two of the four devices yielding statistically significant benefit with medium-to-large effect sizes. Reduction in self-rated listening effort was noted from the use of all four devices, with a moderate effect size. Degree of hearing loss (4-frequency pure-tone average) was not significantly associated with the amount of either subjective or objective benefit. Responses to the posttask questionnaire indicated that many of the participants would be willing to use these or similar devices in the “real world.”

Conclusions:

Our findings support the concept that direct-to-consumer hearing devices have the potential to improve objective and/or subjective speech recognition in middle-aged adults, at least when fit to prescriptive targets. Benefit from these devices was not related to degree of hearing loss in this sample of participants.
Dynamics of co-orbital exoplanets in a first-order resonance chain with tidal dissipation
Authors: Couturier Jérémy , Robutel Philippe , Correia Alexandre C.M.
Published: April 2022

Co-orbital planets (in a 1: 1 mean motion resonance) can be formed within a Laplace resonance chain. We develop a secular model tc study the dynamics of the resonance chain p: p : p + 1, where the co-orbital pair is in a first-order mean motion resonance with the outermost third planet. Our model takes into account tidal dissipation through the use of a Hamiltonian version of the constant time-lag model, which extends the Hamiltonian formalism of the point-mass case. We show the existence of several families of equilibria, anc how these equilibria extend to the complete system. In one family, which we call the main branch, a secular resonance between the libration frequency of the co-orbitals and the precession frequency of the pericentres has unexpected dynamical consequences when tidal dissipation is added. We report the existence of two distinct mechanisms that make co-orbital planets much more stable within the p : p : p + 1 resonance chain rather than outside it. The first is due to negative real parts of the eigenvalues of the linearised system with tides, in the region of the secular resonance mentioned above. The second comes from non-linear contributions of the vector fielt and is due to eccentricity damping. These two stabilising mechanisms increase the chances of a future detection of exoplanets in the co-orbital configuration.
Muonium Lamb shift: theory update and experimental prospects
Authors: Janka Gianluca , Ohayon Ben , Crivelli Paolo
Published: April 2022

We review the theory of the Lamb shift for muonium, provide an updated numerical value and present the prospects of the Mu-MASS collaboration at PSI to improve upon their recent measurement. Due to its smaller nuclear mass, the contributions of the higher-order recoil corrections (160 kHz level) and nucleus self-energy (40 kHz level) are enhanced for muonium compared to hydrogen where those are below the level of the latest measurement performed by Hessels et al. and thus could not be tested yet. The ongoing upgrades to the Mu-MASS setup will open up the possibility to probe these contributions and improve the sensitivity of this measurement to searches for new physics in the muonic sector.
Feasibility study of tau-lepton anomalous magnetic moment measurements with ultra-peripheral collisions at the LHC
Authors: Bühler Paul , Burmasov Nazar , Lavička Roman , Kryshen Evgeny
Published: April 2022

Precision measurements of the anomalous electromagnetic moment of leptons (al) may serve as one of the most promising directions in the search for new physics beyond the Standard Model. While the experimental value of the electron magnetic moment agrees with theoretical predictions with up to 11 significant digits, the muon magnetic moment shows deviations from the Standard Model value at the level of 4.2 sigma, indicating the possible occurrence of new physics effects. Although the aτ of the tau lepton with its heavy mass is expected to be ${{m_\tau ^2} \mathord{\left/
{\vphantom {{m_\tau ^2} {m_\mu ^2}}} \right.
\kern-\nulldelimiterspace} {m_\mu ^2}} \approx 280$ times more sensitive to new physics effects than aμ, measurements of this quantity are rare. This is because the standard spin precession methods are not suitable for aτ measurements due to the very short tau lifetime.

Ultra-peripheral collisions of heavy ions at the LHC may serve as an alternative tool to measure aτ. In ultra-peripheral collisions, hadronic interactions are strongly suppressed and long-distance electromagnetic processes dominate, providing an environment to study the electromagnetic properties of the tau lepton. The di-tau production process PbPb → PbPbγγ → PbPbττ contains two gamma-tau vertices and hence provides enhanced sensitivity to the anomalous magnetic and electric moments.

In this contribution we discuss the feasibility of the aτ measurement in ultraperipheral collisions with the ALICE experiment and present projections of the sensitivity of the measurement for the upcoming heavy ion run in 2022 at LHC.
Machine learning techniques deep underwater in km3net
Authors: Circella Marco , Eberl Thomas
Published: April 2022

Deep in the water of the Mediterranean Sea, the KM3NeT detectors aim at the exploration of the cosmos through the detection of neutrinos and to determine the neutrino mass ordering. Machine learning techniques are widely used to push the performance of the detectors to the limit.
Numerical analysis of the Landau–Lifshitz–Gilbert equation with inertial effects
Authors: Ruggeri Michele
Published: April 2022

We consider the numerical approximation of the inertial Landau–Lifshitz–Gilbert equation (iLLG), which describes the dynamics of the magnetisation in ferromagnetic materials at subpicosecond time scales. We propose and analyse two fully discrete numerical schemes: The first method is based on a reformulation of the problem as a linear constrained variational formulation for the linear velocity. The second method exploits a reformulation of the problem as a first order system in time for the magnetisation and the angular momentum. Both schemes are implicit, based on first-order finite elements, and generate approximations satisfying the unit-length constraint of iLLG at the vertices of the underlying mesh. For both methods, we prove convergence of the approximations towards a weak solution of the problem. Numerical experiments validate the theoretical results and show the applicability of the methods for the simulation of ultrafast magnetic processes.
Assessment and Monitoring of Coagulation in Patients with COVID-19: A Review of Current Literature
Authors: Uzun Günalp , Althaus Karina , Hammer Stefanie , Bakchoul Tamam
Published: April 2022

Coagulation abnormalities are common in patients with COVID-19 and associated with high morbidity and mortality. It became a daily challenge to navigate through these abnormal laboratory findings and deliver the best possible treatment to the patients. The unique character of COVID-19-induced coagulopathy necessitates not only a dynamic follow-up of the patients in terms of hemostatic findings but also the introduction of new diagnostic methods to determine the overall function of the coagulation system in real time. After the recognition of the high risk of thromboembolism in COVID-19, several professional societies published their recommendations regarding anticoagulation in patients with COVID-19. This review summarizes common hemostatic findings in COVID-19 patients and presents the societal recommendations regarding the use of coagulation laboratory findings in clinical decision-making. Although several studies have investigated coagulation parameters in patients with COVID-19, the methodological shortcomings of published studies as well as the differences in employed anticoagulation regimens that have changed over time, depending on national and international guidelines, limit the applicability of these findings in other clinical settings. Accordingly, evidence-based recommendations for diagnostics during acute COVID-19 infection are still lacking. Future studies should verify the role of coagulation parameters as well as viscoelastic methods in the management of patients with COVID-19.
Phenotypic Changes in Mammary Adenocarcinoma (4T1) cells In Vitro after Treatment with Carcinosinum
Authors: Silva Thaís Cristina da , Santos William Alves dos , Pinto Sandra A.G. , Rocha Paulo Ricardo Dell'Armelina , Hurtado Elizabeth Cristina Perez , Bonamin Leoni Villano
Published: April 2022

Objective The present study aimed to identify possible phenotypic changes in 4T1 (murine mammary adenocarcinoma) cells in vitro, including viability, HER-2 (human epidermal growth factor receptor-type 2) expression, and metastatic potential, after treatment with Carcinosinum in different homeopathic dilutions (12cH, 30cH, 200cH) shaken mechanically in pure, sterile, water from a commercial stock dilution.

Methods Treated cells were cultured in R10 medium, using 24-well plates, 105 cells per well, and treated with vehicle, Carcinosinum 12cH, 30cH or 200cH; untreated cells were used as the baseline control. After 24 hours of treatment, the percentage of apoptotic cells was analyzed by annexin V. Cell morphology was evaluated by microscopy after hematoxylin-eosin and Giemsa staining, whilst HER-2 expression was assessed using immunocytochemistry. The metastatic potential was determined by the expression and activity of the enzyme matrix metalloproteinase 9 (MMP-9) using zymography. The cytokine profile was established using the cytometric bead array method.

Result Treatment of 4T1 cells in vitro with Carcinosinum 30cH produced an increase in the number of annexin V-positive cells (apoptosis) and decreased expression of proactivated MMP-9. Cells treated with Carcinosinum 200cH presented hyper-expression of HER-2 on the plasma membrane, identified by immunocytochemistry. There were no differences in cytokine production among treatments.

Conclusion The data show promising results for Carcinosinum 30cH in vitro, but in vivo studies are also required to evaluate the role of tumor microenvironment in its effects.
Multinational oil corporations, policy violation and environmental damage in rivers state of Nigeria: a theistic ethics approach
Authors: Josiah Ucheawaji Godfrey , Akpuh Charles Chinanu
Published: April 2022

Achieving a sustainable environment is not unconnected with a pragmatic adherence to environmental policies in any given society. The continuous and expanding experience of environmental degradation and its attendant consequences on human and other lives in Rivers State of Nigeria still call for urgent attention for enduring solution. Yet, it seems that all efforts made toward resolving the problem have yielded very few positive results because the root cause of the problem(s) has not been given adequate attention. This study explored the organic connectedness between breaches (i.e., policy violation) of environmental regulations (as a major cause of the problem) and environmental chaos (as the consequence of the breach) in Rivers State of Nigeria, from the theistic ethics standpoint. To investigate the actuality of the connectedness of the breaches and the incessant environmental decadence in the study location, 30 copies of self-constructed, close-ended questionnaire were administered to a purposively selected sample of 30 Community Liaison Officers (CLOs) of the major oil business firms across the entire three Senatorial Districts of Rivers State. Out of the 30 administered questionnaire, 26 valid copies (86.7%) were retrieved and analysed, using frequencies, simple percentage counts, and regression analysis. A total of 88.5% of the CLOs confirmed that breaches in fundamental environmental policies were major causes of the environmental chaos and other associated problems in Rivers State, Nigeria. Also, pipeline vandalism, oil spillages, and oil theft typified breaches of theistic and other environmental regulations with ecological consequences. The F-test from the regression analysis shows that the value of F-calculated (6.633) is greater than F-tabulated (3.86) taking cognizant of the P-value of 0.01, which is lesser than 0.05 level of probability. This confirmed a significant relationship between contravention of law and ethical principles, and environmental degradation in Rivers State. Furthermore, the value of coefficient of correlation (r) is 0.126. This confirmed a positive relationship between violation of environmental policies (X) and environmental degradation (Y) in Rivers State. The paper concluded that adherence to the theistic and other environmental policies by oil firms in Rivers State could serve as respite to the environment.
A quasi-experimental controlled study of a school-based mental health programme to improve the self-esteem of primary school children
Authors: Iwahori Miyuki , Oshiyama Chiaki , Matsuzaki Hideo
Published: April 2022

Children’s mental health problems are associated with a low self-esteem. Harter has proposed that recognising competence in personal importance and social support would improve students’ self-esteem. However, to the best of our knowledge, no study has examined Harter’s theory for primary school children. This study aimed to test the effectiveness of the Treasure File Programme for improving primary school children’s self-esteem. The programme’s effectiveness was evaluated regarding the students’ self-esteem, physical well-being, emotional well-being, family relationships, friendships, and school performance. A total of 794 primary school students (aged 7–11 years) in the intervention group and 592 in the control group were recruited in a quasi-experimental study design. The intervention group indicated significant improvement in the self-esteem domain compared to the control group. However, no intervention effects were observed on physical well-being, emotional well-being, family, friends, and school. These findings indicate that this programme is effective in improving self-esteem in primary school students. Given the importance of self-esteem in children’s mental health, this programme may be helpful as a primarily educational programme option to address mental health problems in primary school children.
Oxygen-vacancy induced ferroelectricity in nitrogen-doped nickel oxide
Authors: Dragoman Mircea , Vulpe Silviu , Aperathithis Elias , Aivalioti Chrysa , Romanitan Cosmin , Dinescu Adrian , Dragoman Daniela , Aldrigo Martino , Djourelov Nikolay , Modreanu Mircea , Moldovan Antoniu
Published: April 2022

This paper reports the onset of ferroelectricity in NiO by breaking the crystallographic symmetry with oxygen vacancies created by N doping. Nitrogen-doped NiO was grown at room temperature by RF sputtering of Ni target in Ar–O2–N2 plasma on silicon and fused silica substrates. The impact of the nitrogen doping of NiO on microstructural, optical, and electrical properties has been investigated. According to x-ray diffraction investigations, by increasing the N doping level in NiO, a transition from (002) to a (111) preferential orientation for the cubic NiO phase was observed, as well as a lattice strain relaxation, that is usually ascribed to structural defect formation in crystal. The x-ray diffraction pole figures the presence of a distorted cubic structure in NiO and supports the Rietveld refinement findings related to the strain, which pointed out that nitrogen doping fosters lattice imperfections formation. These findings were found to be in agreement with our far-infrared measurements that revealed that upon nitrogen doping a structural distortion of the NiO cubic phase appears. X-ray photoemission spectroscopy measurements reveal the presence of oxygen vacancies in the NiO film following nitrogen doping. Evidence of ferroelectricity in nitrogen-doped NiO thin films has been provided by using the well-established Sawyer–Tower method. The results reported here provide the first insights on oxygen-vacancy induced ferroelectricity in nitrogen-doped nickel oxide thin films.
Quasi-isentropic compression of LiH above 400 GPa using magnetocumulative generator
Authors: Zhang X. P. , Gu Z. W. , Xiao Z. Q. , Tan F. L. , Ye X. Q. , Tong Y. J. , Tang X. S. , Zhou Z. Y. , Cheng C. , Zhao J. , Luo B. Q. , Li J. M. , Kuang X. W. , Zhao J. H. , Sun C. W. , Liu C. L.
Published: April 2022

The knowledge of high-pressure behavior of LiH is significant for the validation of fundamental theoretical models and applications in thermonuclear materials and potential energy supplies. The compressibility of 7LiH under isentropic compression at high pressure was investigated experimentally and theoretically. The experimental technique for quasi-isentropic compression with low-density materials was developed using the magnetocumulative generator CJ-100 and x-ray flash radiography. The x-ray images and extracted interface of the sample target in dynamic flash radiography experiments were obtained. According to each interface size of the target both before and after compression, the compression ratio of 7LiH and reference material aluminum was obtained. The density of the reference and using its known isentropic curve provide the pressure in the reference. The pressure in 7LiH was deduced from the pressure in the reference and using the calculated gradient correction factor. The quasi-isentropic data point at 438 GPa was obtained experimentally. A semiempirical three-term complete equation of state was constructed and validated for 7LiH using the theory of Mie–Grüneisen–Debye with experimental data from the literature. The quasi-isentrope data point is reasonably consistent with the theoretical results. The quasi-isentropic experimental techniques and results broaden the existing research scope and are practical and helpful to further validate theoretical models in the future.
Insights into the charge carrier dynamics in perovskite/Si tandem solar cells using transient photocurrent spectroscopy
Authors: Ghorai Anaranya , Kumar Prashant , Mahesh Suhas , Lin Yen-Hung , Snaith Henry J. , Narayan K. S.
Published: April 2022

Direct bandgap perovskite and indirect bandgap Si, which form the two active layers in a tandem solar cell configuration, have different optoelectronic properties and thicknesses. The charge-carrier dynamics of the two-terminal perovskite-on-Si tandem solar cell in response to a supercontinuum light pulse is studied using transient photocurrent (TPC) measurements. Spectral dependence of TPC lifetime is observed and can be classified into two distinct timescales based on their respective carrier generation regions. The faster timescale (∼500 ns) corresponding to the spectral window (300–750 nm) represents the top-perovskite sub-cell, while the slower timescale regime of ∼25 μs corresponds to the bottom-Si sub-cell (>700 nm). Additionally, under light-bias conditions, the transient carrier dynamics of the perovskite sub-cell is observed to be coupled with that of the Si sub-cell. A sharp crossover from the fast-response to a slow-response of the device as a function of the light-bias intensity is observed. These results along with a model based on transfer matrix formulation highlight the role of charge-carrier dynamics in accessing higher efficiencies in tandem solar cells. The carrier transit times and lifetimes in addition to their optical properties need to be taken into account for optimizing the performance.
Modulated terahertz generation in femtosecond laser plasma filaments by high-field spintronic terahertz pulses
Authors: Liu Shaojie , Lu Chenhui , Fan Zhengquan , Wang Shixiang , Li Peiyan , Chen Xinhou , Pan Jun , Xu Yong , Liu Yi , Wu Xiaojun
Published: April 2022

Strong-field terahertz (THz) light-matter interaction provides various nonlinear control approaches in condensed matter physics, energy and material sciences, electron acceleration, and manipulation. Recently developed spintronic THz emission with minimum complexities has been demonstrated to have the capability for generating high field strengths. Up to now, nonlinear applications based on the spintronic THz transients have yet been realized. Here, we report THz emission from two-color femtosecond laser plasma filaments modulated by a 60-kV/cm THz pulse from W/CoFeB/Pt heterostructures. Enhanced THz radiation based on electron acceleration in plasma is recorded when the direction of the spintronic THz modulating field is in line with that of the electron movement. This behavior is quantitatively reproduced by a local current model of the plasma THz source. Our experimental and theoretical results may inspire further nonlinear THz investigation and accelerate ultrafast THz engineering in matter.
Complex energies and transition dipoles for shape-type resonances of uracil anion from stabilization curves via Padé
Authors: Bouskila Gal , Landau Arie , Haritan Idan , Moiseyev Nimrod , Bhattacharya Debarati
Published: April 2022

Absorption of slow moving electrons by neutral ground state nucleobases has been known to produce resonance metastable states. There are indications that such metastable states may play a key role in DNA/RNA damage. Therefore, herein, we present an ab initio non-Hermitian investigation of the resonance positions and decay rates for the low lying shape-type states of the uracil anion. In addition, we calculate the complex transition dipoles between these resonance states. We employ the resonance via Padé (RVP) method to calculate these complex properties from real stabilization curves by analytical dilation into the complex plane. This method has already been successfully applied to many small molecular systems, and herein, we present the first application of RVP to a medium-sized system. The presented resonance energies are optimized with respect to the size of the basis set and compared with previous theoretical studies and experimental findings. Complex transition dipoles between the shape-type resonances are computed using the optimal basis set. The ability to calculate ab initio energies and lifetimes of biologically relevant systems paves the way for studying reactions of such systems in which autoionization takes place, while the ability to also calculate their complex transition dipoles opens the door for studying photo-induced dynamics of such biological molecules.
Ge–Ge0.92Sn0.08 core–shell single nanowire infrared photodetector with superior characteristics for on-chip optical communication
Authors: Singh Sudarshan , Mukherjee Subhrajit , Mukherjee Samik , Assali Simone , Luo Lu , Das Samaresh , Moutanabbir Oussama , Ray Samit K.
Published: April 2022

Recent development on Ge1−xSnx nanowires with high Sn content, beyond its solid solubility limit, makes them attractive for all group-IV Si-integrated infrared photonics at the nanoscale. Herein, we report a chemical vapor deposition-grown high Sn-content Ge–Ge0.92Sn0.08 core–shell based single nanowire photodetector operating at the optical communication wavelength of 1.55 μm. The atomic concentration of Sn in nanowires has been studied using x-ray photoelectron and Raman spectroscopy data. A metal–semiconductor–metal based single nanowire photodetector, fabricated via an electron beam lithography process, exhibits significant room-temperature photoresponse even at zero bias. In addition to the high-crystalline quality and identical shell composition of the nanowire, the efficient collection of photogenerated carriers under an external electric field results in the superior responsivity and photoconductive gain as high as ∼70.8 A/W and ∼57, respectively, at an applied bias of −1.0 V. The extra-ordinary performance of the fabricated photodetector demonstrates the potential of GeSn nanowires for future Si CMOS compatible on-chip optical communication device applications.
Effects of biomechanical properties of blood on surface tension-driven flows in superhydrophilic channels
Authors: Pasias D. , Koutsokeras L. , Passos A. , Constantinides G. , Balabani S. , Kaliviotis E.
Published: April 2022

Surface tension-driven microfluidic flows offer low-cost solutions for blood diagnostics due to the pump-less flow handling. Knowledge of the influence of the biomechanical properties of blood on such flows is key to design such devices; however, a systematic examination of that influence is lacking in the literature. We report on the effects of specific hemorheological factors for flows in a superhydrophilic microchannel. Whole human blood and erythrocyte suspensions in phosphate buffer and dextran solutions were tested. Heat-treated counterparts of the aforementioned samples were produced to alter the deformability of the cells. The flow of the samples was imaged and characterized using micro-particle image velocimetry and tracking techniques to probe the effects of hematocrit, and erythrocyte aggregation and deformability. Meniscus velocities, velocity profiles in the channel, and local and bulk shear rates were derived. The mean velocity of blood was affected by the increasing sample viscosity and the reduced erythrocyte deformability as expected. The increased erythrocyte aggregation appeared to affect more the shape of the velocity profiles in the normal, compared to the heat-treated samples. Very high shear rates are observed in the early stages of the flow, suggesting high erythrocyte disaggregation, persisting sufficiently strong until the flow reaches the end of the channel.
Observation of domain structure in non-collinear antiferromagnetic Mn3Sn thin films by magneto-optical Kerr effect
Authors: Uchimura Tomohiro , Yoon Ju-Young , Sato Yuma , Takeuchi Yutaro , Kanai Shun , Takechi Ryota , Kishi Keisuke , Yamane Yuta , DuttaGupta Samik , Ieda Jun'ichi , Ohno Hideo , Fukami Shunsuke
Published: April 2022

We perform hysteresis-loop measurement and domain imaging for (11¯00)-oriented D019-Mn3+xSn1-x (−0.11≤x≤0.14) thin films using the magneto-optical Kerr effect (MOKE) and compare it with the anomalous Hall effect (AHE) measurement. We obtain a large Kerr rotation angle of 10 mdeg, comparable with bulk single-crystal Mn3Sn. The composition x dependence of AHE and MOKE shows a similar trend, suggesting the same origin, i.e., the non-vanishing Berry curvature in the momentum space. Magnetic domain observation at the saturated state shows that x dependence of AHE and MOKE is explained by the amount of the reversible area that crucially depends on the crystalline structure of the film. Furthermore, in-depth observation of the reversal process reveals that the reversal starts with nucleation of sub-micrometer-scale domains dispersed in the film, followed by domain expansion, where the domain wall preferentially propagates along the [112¯0] direction. Our study provides a basic understanding of the spatial evolution of the reversal of the chiral-spin structure in non-collinear antiferromagnetic thin films.
Study of preferential concentration in turbulent flows using combined graph theory and Voronoï analysis
Authors: Andrade Paul , Hardalupas Yannis , Charalampous Georgios
Published: April 2022

Collisions between particles in turbulent flows may be enhanced by the formation of clusters due to the preferential concentration effect. However, the internal sub-structure of the clusters remains unclear. This paper describes using the “degree of a node” and the “shortest path length” from graph theory, in combination with Voronoï analysis, to gain further insight into both the structure and internal sub-structure of a cluster. This is demonstrated on experimental measurements obtained from a confined counter-flow/jet system. A minority of the particles, which comprise large clusters, are found to have a significantly large number of neighboring particles for collisions. However, particles which comprise small clusters typically have a random number of neighbors.
The Wsp system ofPseudomonas aeruginosalinks surface sensing and cell envelope stress
Authors: O’Neal Lindsey , Baraquet Claudine , Suo Zehui , Dreifus Julia E. , Peng Yun , Raivio Tracy L. , Wozniak Daniel J. , Harwood Caroline S. , Parsek Matthew R.
Published: April 2022

Significance

Bacteria must respond quickly to environmental changes to survive. One way bacteria can respond to environmental stress is by undergoing a lifestyle transition from individual, free-swimming cells to a surface-associated community called a biofilm characterized by aggregative growth. The opportunistic pathogenPseudomonas aeruginosauses the Wsp chemosensory system to sense an unknown surface-associated cue. Here we show that the Wsp system senses cell envelope stress, specifically conditions that promote unfolded or misregulated periplasmic and inner membrane proteins. This work provides direct evidence that cell envelope stress is an important feature of surface sensing inP. aeruginosa.
Three-dimensional imaging for the quantification of spatial patterns in microbiota of the intestinal mucosa
Authors: Mondragón-Palomino Octavio , Poceviciute Roberta , Lignell Antti , Griffiths Jessica A. , Takko Heli , Ismagilov Rustem F.
Published: April 2022

Significance

Many human diseases are causally linked to the gut microbiota, yet the field still lacks mechanistic understanding of the underlying complex interactions, because existing tools cannot simultaneously quantify microbial communities and their native context. In this work, we provide an approach to tissue clearing and preservation that enables 3D visualization of the biogeography of the host–microbiota interface. We combine this tool with sequencing and multiplexed microbial labeling to provide the field with a platform on which to discover patterns in the spatial distribution of microbes. We validated this platform by quantifying bacterial distribution in cecal mucosa at different stages of antibiotic exposure. This approach may enable researchers to formulate and test new hypotheses about host–microbe and microbe–microbe interactions.
Cornelia de Lange syndrome mutations in NIPBL can impair cohesin-mediated DNA loop extrusion
Authors: Panarotto Melanie , Davidson Iain F. , Litos Gabriele , Schleiffer Alexander , Peters Jan-Michael
Published: April 2022

Cornelia de Lange syndrome (CdLS) is a developmental multisystem disorder frequently associated with mutations in NIPBL. CdLS is thought to arise from developmental gene regulation defects, but how NIPBL mutations cause these is unknown. Here we show that several NIPBL mutations impair the DNA loop extrusion activity of cohesin. Because this activity is required for the formation of chromatin loops and topologically associating domains, which have important roles in gene regulation, our results suggest that defects in cohesin-mediated loop extrusion contribute to the etiology of CdLS by altering interactions between developmental genes and their enhancers.
Machine learning recognition of protein secondary structures based on two-dimensional spectroscopic descriptors
Authors: Ren Hao , Zhang Qian , Wang Zhengjie , Zhang Guozhen , Liu Hongzhang , Guo Wenyue , Mukamel Shaul , Jiang Jun
Published: April 2022

Significance

We propose and demonstrate the use of two-dimensional UV (2DUV) spectroscopic features as observable-based descriptors for a machine learning protocol aimed at discriminating protein secondary structure motifs. The 2DUV spectra viewed as grayscale images were fed into convolutional neural networks (CNNs), resulting in accurate spectrum-structure correlation model. This enables an automated secondary structure recognition with accuracies of 97% (91%) for (non-)homologous protein segments. The success of protein 2DUV descriptors for machine learning is ascribed to their unique cross-peak information that reflects couplings between electronic transitions located at different chromophores. Incorporating coupling information is crucial for connecting the descriptors to the protein structure.
State-selective electron capture in collisions of fully stripped neon ions with ground-state hydrogen
Authors: Kotian A M , Plowman C T , Abdurakhmanov I B , Bray I , Kadyrov A S
Published: April 2022

Electron capture and ionisation in bare neon ion collisions with ground-state atomic hydrogen are modelled over the energy range from 1 to 2000 keV/u using the two-center semiclassical wave-packet convergent close-coupling method. The calculated total electron-capture cross section agrees very well with the molecular and atomic orbital close-coupling calculations at low and intermediate energies. Our results slightly overestimate the experimental results by Meyer et al [1985 Phys. Rev. A
32 3310], but underestimate the measurements by Panov et al [1983 Phys. Scr.
T3 124] available only below 10 keV/u. At higher energies, where there are no measurements, the results also agree very well with the classical trajectory Monte-Carlo results. Partial n and nl-resolved electron-capture cross sections, important for fusion plasma diagnostics, have also been calculated for final states up to n = 10, where n and l are the final state principal and angular momentum quantum numbers, respectively. The results are generally in good agreement with the atomic calculations. However, due to the finer energy grid used, we are able to detect pronounced oscillations in the state-selective cross sections for n ⩾ 8 at energies below 10 keV/u. Our results for the total ionisation cross section are overall in good agreement with the latest classical trajectory Monte-Carlo results.
Minimizing the linewidth enhancement factor in multiple-quantum-well semiconductor optical amplifiers
Authors: Aşırım Özüm Emre , Jirauschek Christian
Published: April 2022

Semiconductor optical amplifiers (SOAs) often exhibit pronounced phase noise owing to their inherently high linewidth enhancement factor (LWEF). The signal to noise ratio of a SOA is often decreased due to refractive index fluctuations in the gain medium causing distorted phase relationship between the generated photons, which is quantified by the LWEF. A simple and precise theoretical model that offers a prescription for minimizing the LWEF in SOAs is unavailable in the literature. In this study, we have developed an inclusive yet simple algorithmic model that aims to both represent the variation and to provide a strategy for minimizing the LWEF in multiple-quantum-well (MQW) based SOAs. The results of the presented model were verified via a reasonable agreement with experimental results. This study provides a theoretical description of how to adjust the LWEF through tuning of the most critical MQW SOA parameters in the design stage.
High pressure nanoarchitectonics and metallization of barium chloride and barium bromide
Authors: Wei Shubo , Zhang Peiyu , Liu Hanyu
Published: April 2022

As one of the most prototypical AX
2-type compounds, barium halide shared the cubic structure with Fm−3m symmetry for BaCl2 or orthorhombic structure with Pnma symmetry for BaBr2 at ambient pressure. In this work, we explored the crystal structures of BaCl2 and BaBr2 under high pressure. We predicted a thermodynamically more favored structure with orthorhombic Cmcm symmetry for both BaCl2 and BaBr2, at 74 and 47 GPa, respectively. Our simulations reveal that the metallic feature of Cmcm BaCl2 and Cmcm BaBr2 under high pressure. The present results improve the understanding of high-pressure structures of AX
2 compounds at extremely high-pressure conditions.
Perfect spin-filtering effect in molecular junctions based on half-metallic penta-hexa-graphene nanoribbons
Authors: Deng Yuan-Xiang , Chen Shi-Zhang , Hong Jun , Jia Pin-Zhen , Zhang Yong , Yu Xia , Chen Ke-Qiu
Published: April 2022

The design and control of spintronic devices is a research hotspot in the field of electronics, and pure carbon-based materials provide new opportunities for the construction of electronic devices with excellent performance. Using density functional theory in combination with nonequilibrium Green’s functions method, we design spin filter devices based on Penta-hexa-graphene (PHG) nanoribbons—a carbon nanomaterial in which the intrinsic magnetic moments combines with edge effects leading to a half-metallic property. Spin-resolved electronic transport studies show that such carbon-based devices can achieve nearly 100% spin filtering effect at low bias voltages. Such SEF can resist the influence of hydrogen passivation at different positions, but hardly survive under a hydrogen-rich environment. Our analysis show that the perfect SEF transport properties are caused by the magnetic and electronic properties of PHG nanoribbons, especially the magnetic moments on the quasi-sp
3 carbons. These interesting results indicate that PHG nanomaterials have very prominent application prospects in future spintronic devices.
Ultra-low turn-off current 2D material heterojunction selectors: first-principle calculations
Authors: Dai Yuehua , Hu Guyue , Li Xing , Wang Feifei , Yang Fei , Wu Zuheng
Published: April 2022

Selector is important for emerging non-volatile memory arrays to settle the sneak path problem and inhibit the array leakage current. The turn-off current of the selector determines the ability of selector to inhibit the leakage current. Here, selector models with the structure of graphene/g-GaN/graphene show ultra-low turn-off current. First, combining the plane electrostatic potential and the current–voltage characteristic of switch layers of heterojunctions, it can be concluded that the resistance switching mechanism is based on Schottky barrier at the interface. Moreover, three selector models with different switch layers (model A, B, C) are explored to study the influence of the switch layer structure on the device. The plane average electrostatic potential of selectors shows that the different structures of the switch layer result in the difference of the threshold voltage (V
th), owing to the different interface barrier. Finally, the electronic transmission shows each selector have an ultra-low turn-off current (I
off) and high nonlinearity, which could better suppress the leakage current in array. This work supplies a potential implementation scheme for the selector with ultra-low turn-off current.
Radiation shielding properties of Cd-Bi-Pb-Zn-borate glasses: influence of Bi2O3 activation
Authors: Aboud Haydar , Mkhaiber Ahmed Fadhil , Alajermi Yasser
Published: April 2022

We report the detail characterizations and γ-radiation protecting characteristics of some new types of cadmium (Cd)-bismuth (Bi)-lead (Pb)-zinc (Zn)-borate glasses of the form (70-x)B2O3-10ZnO-10PbO-10CdO-xBi2O3 (with x = 0 to 20 mol%) synthesized via melt-quenching process. The influence of various Bi2O3 contents on the γ-radiation shielding traits of the obtained glass samples was evaluated by exposing them at different γ-ray energies (0.356, 0.662, 1.173, and 1.33 MeV) which were recorded by the NaI detector. XRD analyses of the as-quenched specimens showed their glassy phase. A comparison between theoretically computed (Phy-X and XCOM software) and experimentally measured various shielding parameters of the glass samples were performed. Irrespective of the Bi2O3 contents, the values of the mass attenuation coefficient, effective atomic number and effective electron density of the prepared glass samples were reduced with the increase of γ-ray energies. Furthermore, the theoretically calculated values of all the shielding parameters were agreed well with the measured ones. Regardless of the γ-ray energy exposures, the shielding capacity of the studied glasses was improved with the increase of Bi2O3 doping contents. The proposed glass compositions were asserted to be useful for the γ-ray absorber applications.
Graphene-based ultra-wideband absorber for terahertz applications using hexagonal split ring resonators
Authors: Upender Patri , Kumar Amarjit
Published: April 2022

In this paper, a hexagonal split ring ultra-wideband absorber is proposed at THz frequency. The proposed structure consists of four graphene based hexagonal split rings, a dielectric substrate and graphene layer at the bottom. The proposed absorber achieves an ultra-wideband absorption characteristics from 0.95 THz to 2.96 THz with percentage bandwidth of 102.8% and bandwidth of 2.1THz with absorptivity beyond 90%. Also, 100% absorption is achieved from 2.07 to 2.33 THz making this unique feature for THz applications. Ultra-wideband response is mainly resulted because of overlapping of strong Electromagnetic (EM) resonance of the four split rings. The modes generated within the graphene split rings are merged for achieving ultra wide band response. Furthermore, the proposed absorber is polarization insensitive because of symmetry geometry and also exhibits absorption greater than 90% for incidence angle up to 75° for both TE and TM waves. In addition, tunability is achieved by varying the graphene chemical potential. These features make the proposed metal free absorber useful for terahertz applications and future nanoscale systems. The proposed absorber shows narrow absorption characteristics for higher graphene chemical potential values which can also be utilized for sensor applications.
Dissolution of four-stage to three-stage dynamic scaling behavior with stabilization of relaxor character in K0.5Bi0.5TiO3 based binary system
Authors: Pappachan Seethal , Rashid A , Nambi Venkatesan Giridharan
Published: April 2022

Here, we report the dynamic scaling of a ferroelectric material at the transition compositions, from normal ferroelectric to relaxor ferroelectric (relaxor), with K0.5Bi0.5TiO3 (KBT) as base material and LiNbO3 (LN) as the substituent. Ferroelectric (Polarization Vs Electric field), piezoelectric (Strain Vs. Electric field) and temperature dependent dielectric data reveals that 0.98KBT-0.02LN (KLN2) has more of normal ferroelectric character while relaxor character is dominating in 0.97KBT-0.03LN (KLN3). The dynamic scaling study with constant frequency and varying electric field shows the evolution of a four-stage behavior for KLN2, distinct from previous reports with two-stage and three-stage behavior, while KLN3 shows 3-stage dynamic behavior. The evolution of a four-stage dynamic behavior is attributed to the clamping of domain walls at lower electric fields. The dissolution of the first and second stages into a single stage with the increase of LN content from 2% to 3% is attributed to the extinction of the clamping effect due to the emergence of polar nanodomains. To generalize the dissolution of stages with the increase of relaxor character, further studies are required.
Ethical implications of visual neuroprostheses—a systematic review
Authors: van Velthoven E A M , van Stuijvenberg O C , Haselager D R E , Broekman M , Chen X , Roelfsema P , Bredenoord A L , Jongsma K R
Published: April 2022

Objective. The aim of this review was to systematically identify the ethical implications of visual neuroprostheses.Approach. A systematic search was performed in both PubMed and Embase using a search string that combined synonyms for visual neuroprostheses, brain–computer interfaces (BCIs), cochlear implants (CIs), and ethics. We chose to include literature on BCIs and CIs, because of their ethically relavant similarities and functional parallels with visual neuroprostheses.Main results. We included 84 articles in total. Six focused specifically on visual prostheses. The other articles focused more broadly on neurotechnologies, on BCIs or CIs. We identified 169 ethical implications that have been categorized under seven main themes: (a) benefits for health and well-being; (b) harm and risk; (c) autonomy; (d) societal effects; (e) clinical research; (f) regulation and governance; and (g) involvement of experts, patients and the public.Significance. The development and clinical use of visual neuroprostheses is accompanied by ethical issues that should be considered early in the technological development process. Though there is ample literature on the ethical implications of other types of neuroprostheses, such as motor neuroprostheses and CIs, there is a significant gap in the literature regarding the ethical implications of visual neuroprostheses. Our findings can serve as a starting point for further research and normative analysis.