bluuebunny/crossref_metadata_2025 huggingface dataset:
High pressures increase α-chymotrypsin enzyme activity under perchlorate stress
Authors: Gault Stewart , Jaworek Michel W. , Winter Roland , Cockell Charles S.
Published: October 2020

Deep subsurface environments can harbour high concentrations of dissolved ions, yet we know little about how this shapes the conditions for life. We know even less about how the combined effects of high pressure influence the way in which ions constrain the possibilities for life. One such ion is perchlorate, which is found in extreme environments on Earth and pervasively on Mars. We investigated the interactions of high pressure and high perchlorate concentrations on enzymatic activity. We demonstrate that high pressures increase α-chymotrypsin enzyme activity even in the presence of high perchlorate concentrations. Perchlorate salts were shown to shift the folded α-chymotrypsin phase space to lower temperatures and pressures. The results presented here may suggest that high pressures increase the habitability of environments under perchlorate stress. Therefore, deep subsurface environments that combine these stressors, potentially including the subsurface of Mars, may be more habitable than previously thought.
Development of a U-bent plastic optical fiber biosensor with plasmonic labels for the detection of chikungunya non-structural protein 3
Authors: George Ankitha , Amrutha M. S. , Srivastava Priyanshu , Sunil Sujatha , Sai V. V. R. , Srinivasan Ramanathan
Published: October 2020

This study presents a novel plasmonic fiber optic sandwich immunobiosensor for the detection of chikungunya, an infectious mosquito-borne disease, using non-structural protein 3 (CHIKV-nsP3) as a biomarker.
Dissolvable Mg/Al layered double hydroxides and surfactant as an extractant for trace analysis of benzoylurea insecticides by high performance liquid chromatography
Authors: Santaladchaiyakit Yanawath , Srijaranai Supalax
Published: October 2020

A simple and rapid preconcentration method using dissolvable Mg/Al LDHs and SDS has been demonstrated for high performance liquid chromatographic analysis of benzoylurea insecticides in water and honey samples.
Deep-eutectic-solvent-based dispersive and emulsification liquid–liquid microextraction methods for the speciation of selenium in water and determining its total content levels in milk formula and cereals
Authors: Shahid Ramsha , Kazi Tasneem Gul , Afridi Hassan Imran , Talpur Farah Naz , Akhtar Asma , Baig Jameel Ahmed
Published: October 2020

Rapid and environmentally friendly ultrasound-assisted dispersive liquid–liquid microextraction (US-DLLμE) and vortex assisted-emulsification liquid–liquid microextraction (VA-ELLμE) methods are proposed for the speciation of selenium in domestic and mineral water samples.
Ultra-small platinum nanoparticles on gold nanorods induced intracellular ROS fluctuation to drive megakaryocytic differentiation of leukemia cells
Authors: Wen Tao , Yang Aiyun , Wang Tao , Jia Mengfan , Lai Xinning , Meng Jie , Liu Jian , Han Bing , Xu Haiyan
Published: October 2020

Au@Pt nanoparticles induce chronic myeloid leukemia cells to differentiate into megakaryocytes by causing intracellular ROS fluctuations with multiple enzyme-like activities.
Combining API in a dual-drug ternary cocrystal approach
Authors: Song Lixing , Robeyns Koen , Tumanov Nikolay , Wouters Johan , Leyssens Tom
Published: October 2020

Two different APIs without direct connecting sites are combined through using an inorganic salt as the glue showing enhanced properties.
Experimental validation of pressure swing regeneration for faster cycling in sorption enhanced dimethyl ether synthesis
Authors: van Kampen Jasper , Booneveld Saskia , Boon Jurriaan , Vente Jaap , van Sint Annaland Martin
Published: October 2020

For the first time, high single-pass production of dimethyl ether from CO2-rich feedstock is demonstrated using pressure swing regeneration alone, allowing enormous increase in productivity.
Solving complex eigenvalue problems on a quantum annealer with applications to quantum scattering resonances
Authors: Teplukhin Alexander , Kendrick Brian K. , Babikov Dmitri
Published: October 2020

The Quantum Annealer Eigensolver (QAE) is applied to the calculation of quantum scattering resonances and their lifetimes on a D-Wave quantum annealer.
Bioinspired wood-like coaxial fibers based on MXene@graphene oxide with superior mechanical and electrical properties
Authors: Chen Xing , Jiang Jianjun , Yang Guoyu , Li Chuanbing , Li Yujun
Published: October 2020

Inspired by the structure of wood, a coaxial MXene@GO fiber with a superior mechanical shell and an electrical core is fabricated.
Enzyme-powered cascade three-dimensional DNA machine for the ultrasensitive determination of kanamycin
Authors: Ye Tai , Zhang Zhiwei , Lu Jiaqi , Yuan Min , Cao Hui , Yin Fengqin , Wu Xiuxiu , Xu Fei
Published: October 2020

A cascade DNA machine was constructed by coupling two types of three-dimensional DNA walker for the ultrasensitive determination of kanamycin.
A controlling parameter of topological defects in two-dimensional covalent organic frameworks
Authors: Zhu You-Liang , Zhao Huan-Yu , Fu Cui-Liu , Li Zhan-Wei , Sun Zhao-Yan
Published: October 2020

A controlling parameter of topological defects of two-dimensional covalent organic frameworks related to chemical reactions is investigated by computer simulations.
Nanonet-nano fiber electrospun mesh of PCL–chitosan for controlled and extended release of diclofenac sodium
Authors: Saudi Sheikh , Bhattarai Shanta R. , Adhikari Udhab , Khanal Shalil , Sankar Jagannathan , Aravamudhan Shyam , Bhattarai Narayan
Published: October 2020

A drug-induced nanonet-nano fiber mesh of PCL–chitosan for high entrapment capacity and extended release of hydrophilic drugs.
Preparing dangling bonds by nanoholes on graphene oxide nanosheets and their enhanced magnetism
Authors: Li Juan , Cui Rongli , Chang Yanan , Huang Huan , Guo Xihong , Wang Jiahao , Liu Ru , Chen Kui , Kong Jianglong , Xing Gengmei , Sun Baoyun
Published: October 2020

The effects of dangling bonds on the magnetic properties of graphene oxide (GO) were studied experimentally by creating nanoholes on GO nanosheets.
Improving the solubility and bioavailability of anti-hepatitis B drug PEC via PEC–fumaric acid cocrystal
Authors: Li Long , Yin Xian-Hong , Diao Kai-Sheng
Published: October 2020

A cocrystal of PEC with fumaric acid (FUA) (PEC–FUA, 1 : 1) was successfully obtained and characterized. The mean AUC0–24 h of the cocrystal is about 4.2 times that of free PEC.
Activation chemistry drives the emergence of functionalised protocells
Authors: Bonfio Claudia , Russell David A. , Green Nicholas J. , Mariani Angelica , Sutherland John D.
Published: October 2020

The complexity of the simplest conceivable cell suggests that the chemistry of prebiotic mixtures needs to be explored to understand the intricate network of prebiotic reactions that led to the emergence of life.
The formyloxyl radical: electrophilicity, C–H bond activation and anti-Markovnikov selectivity in the oxidation of aliphatic alkenes
Authors: Somekh Miriam , Iron Mark A. , Khenkin Alexander M. , Neumann Ronny
Published: October 2020

The formyloxyl radical, formed electrochemically, is electrophilic, yields anti-Markovnikov oxidation products from alkenes, and is effective for C–H bond activation.
Pulsed electrodeposition of well-ordered nanoporous Cu-doped Ni arrays promotes high-efficiency overall hydrazine splitting
Authors: Sun Qiangqiang , Li Yibing , Wang Jianfang , Cao Baoyue , Yu Yan , Zhou Chunsheng , Zhang Guochun , Wang Zenglin , Zhao Chuan
Published: October 2020

Bifunctional double-hierarchy porous structured copper-doped nickel cubic nanopores electrocatalyst via a facile two-step pulse electrodeposition-dealloying strategy enable energy-efficient hydrogen production via Overall Hydrazine Splitting.
[BMIM]BF4-modified PVDF-HFP composite polymer electrolyte for high-performance solid-state lithium metal battery
Authors: Huang Kaixiong , Wang Yanyi , Mi Hongwei , Ma Dingtao , Yong Bo , Zhang Peixin
Published: October 2020

In this work, we demonstrated a novel non-flammable composite polymer electrolyte, which can be applied for high-performance solid-state lithium battery.
An Updated Theoretical Framework for Vocal Hyperfunction
Authors: Hillman Robert E. , Stepp Cara E. , Van Stan Jarrad H. , Zañartu Matías , Mehta Daryush D.
Published: October 2020

Purpose

The purpose of this viewpoint article is to facilitate research on vocal hyperfunction (VH). VH is implicated in the most commonly occurring types of voice disorders, but there remains a pressing need to increase our understanding of the etiological and pathophysiological mechanisms associated with VH to improve the prevention, diagnosis, and treatment of VH-related disorders.

Method

A comprehensive theoretical framework for VH is proposed based on an integration of prevailing clinical views and research evidence.

Results

The fundamental structure of the current framework is based on a previous (simplified) version that was published over 30 years ago (Hillman et al., 1989). A central premise of the framework is that there are two primary manifestations of VH—phonotraumatic VH and nonphonotraumatic VH—and that multiple factors contribute and interact in different ways to cause and maintain these two types of VH. Key hypotheses are presented about the way different factors may contribute to phonotraumatic VH and nonphonotraumatic VH and how the associated disorders may respond to treatment.

Conclusions

This updated and expanded framework is meant to help guide future research, particularly the design of longitudinal studies, which can lead to a refinement in knowledge about the etiology and pathophysiology of VH-related disorders. Such new knowledge should lead to further refinements in the framework and serve as a basis for improving the prevention and evidence-based clinical management of VH.
Extended stellar systems in the solar neighborhood
Authors: Meingast Stefan , Alves João , Rottensteiner Alena
Published: October 2020

We present a novel view on the morphology and dynamical state of ten prominent, nearby (≤500 pc), and young (∼30–300 Myr) open star clusters withGaiaDR2:α Per, Blanco 1, IC 2602, IC 2391, Messier 39, NGC 2451A, NGC 2516, NGC 2547, Platais 9, and the Pleiades. We introduce a pioneering member-identification method that is informed by cluster bulk velocities and deconvolves the spatial distribution with a mixture of Gaussians. Our approach enables inferring the true spatial distribution of the clusters by effectively filtering field star contaminants while at the same time mitigating the effect of positional errors along the line of sight. This first application of the method reveals vast stellar coronae that extend for ≳100 pc and surround the cluster cores, which are comparatively tiny and compact. The coronae and cores form intertwined, coeval, and comoving extended cluster populations, each encompassing tens of thousands of cubic parsec and stretching across tens of degrees on the sky. Our analysis shows that the coronae are gravitationally unbound but largely comprise the bulk of the stellar mass of the populations. Most systems are in a highly dynamic state, showing evidence of expansion and sometimes simultaneous contraction along different spatial axes. The velocity field of the extended populations for the cluster cores appears asymmetric but is aligned along a spatial axis unique to each cluster. The overall spatial distribution and the kinematic signature of the populations are largely consistent with the differential rotation pattern of the Milky Way. This finding underlines the important role of global Galactic dynamics in the fate of stellar systems. Our results highlight the complexity of the Milky Way’s open cluster population and call for a new perspective on the characterization and dynamical state of open clusters.
Kinetically induced low-temperature synthesis of Nb3Sn thin films
Authors: Schäfer N. , Karabas N. , Palakkal J. P. , Petzold S. , Major M. , Pietralla N. , Alff L.
Published: October 2020

Nb3Sn thin films are promising candidates for future application in superconducting radio frequency cavities due to their low surface resistivity, high critical temperature, and critical field, as compared to bulk niobium, which is the current state of the art. In this paper, we report the deposition of Nb3Sn thin films by magnetron co-sputtering at the extremely low temperature of 435°C. These thin films show a critical temperature of 16.3 K, a high critical current density of 1.60×105A/cm2, and a strong shielding effect. The key to achieving low-temperature growth is the independent kinetic control of Nb and Sn species in the sputtering process. From a technological viewpoint, the low-temperature approach paves the way for the use of Nb3Sn as a coating in cryogenic efficient copper based cavities, thereby avoiding the detrimental interdiffusion of Cu.
Experimental investigation of the transonic shock-wave/boundary-layer interaction over a shock-generation bump
Authors: Sun Zhengzhong , Miao Xin , Jagadeesh Chetan
Published: October 2020

A transonic shock-wave/boundary-layer interaction (T-SWBLI) established on a shock-generation bump has been investigated experimentally through particle image velocimetry and high-speed schlieren. The T-SWBLI flowfields have been examined in detail. The near-wall interaction region is visualized with high spatial resolution through schlieren and is further investigated through conditional statistical analysis. The unsteadiness associated with the shock-wave motion is of special interest. The shock-wave locations are extracted to allow spectral analysis of the shock-wave oscillations. The Fourier modal analysis on the schlieren image ensemble is finally reported. The Fourier modes confirm the low-frequency unsteadiness in the shock-wave region and the interaction region. Moreover, the flow fluctuation in the rear part of the interaction region is found to extend into the medium-frequency regime. In addition, the present experimental study showcases that schlieren is a powerful tool in resolving near-wall structures by making use of short exposure time and converged statistics.
A numerical study of the metal jet induced by a shock wave
Authors: Bai Xiao , Li Maojun
Published: October 2020

In this work, a metal jet induced by a shock wave is studied numerically. Different from the previous works on metal jets, we apply a cut-cell based sharp interface numerical method for the study. The evolution of jets is simulated by the in house code CCGF [X. Bai and X. Deng, Adv. Appl. Math. Mech. 9(5), 1052–1075 (2017)], and the interfacial growth rate is computed and compared with some theoretical models. Various initial conditions, including disturbance amplitude and shock wave strength, are considered here. Based on the model of Karkhanis et al. [J. Appl. Phys. 123, 025902 (2018)], a modified model of the spike velocity is presented to achieve better consistency between the numerical simulation and the model formula under more wide initial conditions (here, the scaled perturbed amplitudes involved are 0.125 and 4, and the incident shock wave Mach number is from 2.5 to 8) in this paper. In order to extend the applicability of the empirical models, an approximate formula for the initial velocity V0 is also obtained; a direct prediction of the spike velocity will become possible when the initial perturbed amplitude and incident shock intensity are known. Relevant figures show that the modified model can estimate a more consistent result with the numerical simulation than the VK or GD model.
Synthetic chiral magnets promoted by the Dzyaloshinskii–Moriya interaction
Authors: Hrabec Aleš , Luo Zhaochu , Heyderman Laura J. , Gambardella Pietro
Published: October 2020

The ability to engineer the interactions in assemblies of nanoscale magnets is central to the development of artificial spin systems and spintronic technologies. Following the emergence of the Dzyaloshinskii–Moriya interaction (DMI) in thin film magnetism, new routes have been opened to couple the nanomagnets via strong chiral interactions, which is complementary to the established dipolar and exchange coupling mechanisms. In this Perspective, we review recent progress in the engineering of synthetic magnets coupled by the interlayer and intralayer DMI. We show how multilayer chiral magnetic structures and two-dimensional synthetic antiferromagnets, skyrmions, and artificial spin systems can be realized by simultaneous control of the DMI and magnetic anisotropy. In addition, we show that, with the combination of DMI and current-induced spin–orbit torques, field-free switching of synthetic magnetic elements is obtained as well as all-electric domain wall logic circuits.
Modeling the amplitude growth of Richtmyer–Meshkov instability in shock–flame interactions
Authors: Al-Thehabey Omar Yousef
Published: October 2020

This paper discusses the shock–flame interactions and the aspects associated with it, including the types of interactions, role of interactions in turbulent flames, high pressure generation during interactions, initial pressure effects on interactions, equivalence ratio effects on turbulent interactions, and the Richtmyer–Meshkov instability (RMI). In particular, the theory of RMI and the models associated with its amplitude growth with time have been discussed. Then, a new analytical model, Al-Thehabey model, is presented based on the impulsive acceleration of Richtmyer, not the gravitational acceleration. This model predicts the amplitude growth of the interface perturbation in terms of Atwood number (A), wave number of the perturbation (k), interface velocity (uc), and time (t). This new model’s prediction of the amplitude growth of the RMI is tested on six different combinations of fluids at different interface velocities. The results of the new model are compared with the results of four other existing analytical models and the new model’s performance fared very well. In addition, the new model’s performance has been compared with the experimental results from a shock wave incident on CO2–air, at Mach number, M = 3.08, interface velocity, u = 699.1 m/s, Atwood number, A = 0.206, and wavelength, λ = 990.0 × 10−6 m. The new model showed much closer results with the experimental ones than all other models used in the evaluation. The advantage of this new model is that it is capable of predicting the amplitude growth for both linear, at the early stages of the instability, and non-linear later regimes of the instability. In addition, it covers a larger time-domain than both the Alon et al. and the Sadot et al. models.
Effects of transverse shock waves on early evolution of multi-mode chevron interface
Authors: Guo Xu , Zhai Zhigang , Ding Juchun , Si Ting , Luo Xisheng
Published: October 2020

Effects of transverse shock waves are important in the evolution of a multi-mode interface. However, the related experimental studies are scarce due to the difficulty in creating a well-defined interface. In the present work, we realized such an experimental study by using the soap film technique to form a multi-mode chevron air/SF6 interface. By changing the shock Mach number and the initial amplitude of the interface, the intensity of the transverse shock waves is varied. It is found that the impact of transverse shock waves together with the shock proximity effects flattens the bubble front and reduces the amplitude growth rate. For small initial amplitudes where the transverse shock waves are weak enough, the interface deforms little and the mode coupling is proven to be weak. For high initial amplitudes, the inverse cascade of modes causes the amplitude increase (decrease) of the first mode (high-order modes) at low Mach numbers. As the Mach number increases, the transverse shock waves and the shock proximity effects introduce external forces to the flow, resulting in the generation of additional high-order modes and the reduction in the first mode amplitude. Specifically, the augment of the second harmonic mode amplitude is crucial to flattening the bubble front.
Wireless power transfer through asymmetric topological edge states in diatomic chains of coupled meta-atoms
Authors: Feis J. , Stevens C. J. , Shamonina E.
Published: October 2020

We present a different perspective on wireless power transfer by uniting topological edge states, which are robust states on the edge of a material enforced by topological invariants, with magnetoinductive waves on a 1D diatomic chain of magnetically coupled meta-atoms with intracell coupling exceeding intercell coupling. We show that robust edge states that exist in the stop band of the magnetoinductive waves can, in fact, be used for efficient wireless power delivery by relying on coupling via evanescent modes. Advantages in comparison to wireless power delivery via travelling magnetoinductive waves include lower electromagnetic pollution of the space around the wireless power delivery channel due to the evanescent nature of the modes and robustness against perturbations in the system. This study may change the approach to wireless power systems and near-field sensors based on arrays of coupled meta-atoms.
The Rohingya Little Local: exploring innovative models of refugee engagement in Sydney, Australia
Authors: Bestman Amy , Lloyd Jane , Hawkshaw Barbara , Kabir Jawat , Harris Elizabeth
Published: October 2020

The Rohingya community living in the City of Canterbury-Bankstown in Sydney have been identified as a priority population with complex health needs. As part of ongoing work, AU$10000 was provided to the community to address important, self-determined, health priorities through the Can Get Health in Canterbury program. Program staff worked with community members to support the planning and implementation of two community-led events: a soccer (football) tournament and a picnic day. This paper explores the potential for this funding model and the effect of the project on both the community and health services. Data were qualitatively analysed using a range of data sources within the project. These included, attendance sheets, meeting minutes, qualitative field notes, staff reflections and transcripts of focus group and individual discussions. This analysis identified that the project: (1) enabled community empowerment and collective control over funding decisions relating to their health; (2) supported social connection among the Australian Rohingya community; (3) built capacity in the community welfare organisation –Burmese Rohingya Community Australia; and (4) enabled reflective practice and learnings. This paper presents an innovative model for engaging with refugee communities. Although this project was a pilot in the Canterbury community, it provides knowledge and learnings on the engagement of refugee communities with the health system in Australia.
Childhood maltreatment is associated with changes in mitochondrial bioenergetics in maternal, but not in neonatal immune cells
Authors: Gumpp Anja M. , Boeck Christina , Behnke Alexander , Bach Alexandra M. , Ramo-Fernández Laura , Welz Thilo , Gündel Harald , Kolassa Iris-Tatjana , Karabatsiakis Alexander
Published: October 2020

Significance

Mitochondrial physiology affected by childhood maltreatment (CM) might be a biological link for the intergenerational transmission of CM-related consequences. As mitochondria are intergenerationally transmitted from mother to child, alterations in mitochondrial bioenergetics might influence how maternal CM affects physical and mental development as well as functioning in their children. Our study reports data on mitochondrial bioenergetics in peripheral mononuclear immune cells of mother-newborn dyads, which were positively correlated. Higher maternal maltreatment load was associated with higher mitochondrial respiration and density in mothers, but not in their newborns. Thus, we found no evidence for an intergenerational effect of maternal CM on mitochondrial bioenergetics in immune cells of their newborns.
A microstructural neural network biomarker for dystonia diagnosis identified by a DystoniaNet deep learning platform
Authors: Valeriani Davide , Simonyan Kristina
Published: October 2020

Significance

This research identified a microstructural neural network biomarker for objective and accurate diagnosis of isolated dystonia based on the disorder pathophysiology using an advanced deep learning algorithm, DystoniaNet, and raw structural brain images of large cohorts of patients with isolated focal dystonia and healthy controls. DystoniaNet significantly outperformed shallow machine-learning pipelines and substantially exceeded the current agreement rates between clinicians, reaching an overall accuracy of 98.8% in diagnosing different forms of isolated focal dystonia. These results suggest that DystoniaNet could serve as an objective, robust, and generalizable algorithmic platform of dystonia diagnosis for enhanced clinical decision-making. Implementation of the identified biomarker for objective and accurate diagnosis of dystonia may be transformative for clinical management of this disorder.
The role of IL-22 in intestinal health and disease
Authors: Keir Mary E. , Yi Tangsheng , Lu Timothy T. , Ghilardi Nico
Published: October 2020

The cytokine interleukin-22 (IL-22) is a critical regulator of epithelial homeostasis. It has been implicated in multiple aspects of epithelial barrier function, including regulation of epithelial cell growth and permeability, production of mucus and antimicrobial proteins (AMPs), and complement production. In this review, we focus specifically on the role of IL-22 in the intestinal epithelium. We summarize recent advances in our understanding of how IL-22 regulates homeostasis and host defense, and we discuss the IL-22 pathway as a therapeutic target in diseases of the intestine, including inflammatory bowel disease (IBD), graft-versus-host disease (GVHD), and cancer.
Multidimensional spectroscopy and imaging of defects in synthetic diamond: excitation-emission-lifetime luminescence measurements with multiexponential fitting and phasor analysis
Authors: Jones Daniel C , Alexandrov Yuriy , Curry Nathan , Kumar Sunil , Lanigan Peter M P , McGuinness Colin D , Dale Matthew W , Twitchen Daniel J , Fisher David , Neil Mark A A , Dunsby Christopher , French Paul M W
Published: October 2020

We report the application of phasor analysis and nonlinear iterative fitting to complex spatial and spectroscopic luminescence decay data obtained from multidimensional microscopy of a CVD diamond grown on a HPHT substrate. This spectral and lifetime-resolved analysis enabled spatial mapping of variations in concentrations of nitrogen vacancy (NV) defects in both charge states and the quenching of NV− defects, as well as the identification of SiV− luminescence. These imaging and spectroscopic modalities may be important for reliable fabrication of quantum devices based on such defects in diamond, which will require well-defined and characterised quantum electronic properties.
Nonvolatile electric-field-controlled anomalous Hall effect in ferrimagnetic GdFeCo film
Authors: Wang Junshuai , Li Chaozhong , Ma Lei , Liu Fufu , Chai Guozhi , Jiang Changjun
Published: October 2020

We report on the electric-field-modulated anomalous Hall effect (AHE) under various temperatures in ferrimagnetic GdFeCo/Pb(Mg1/3Nb2/3)0.67Ti0.33O3 (PMN-PT) structures with perpendicular magnetic anisotropy. The coercive field H
c and the magnetic compensation temperature T
M are modulated by applying an electric field to the multilayer. The resistance ratio (ΔR
xy/R
xy) plotted as a function of the symmetric bipolar electric field takes the form of a nonvolatile butterfly-like bipolar curve. The resonance field H
r of the ferromagnetic resonance spectra as a function of the applied electric field shows a typical butterfly-like shape, indicating that strain is the dominant effect in the electric-field-controlled AHE in the ferrimagnetic heterostructure. In addition, a four-state nonvolatile memory is observed upon simultaneous application of pulsed magnetic field and electric field. The results for the electric-field-controlled AHE should prove useful for research into the development of ultra-energy-efficient ferrimagnets.
Ab initio analytic calculation of point defects in AlGaN/GaN heterointerfaces
Authors: Gao Yinlu , Sun Dan , Jiang Xue , Zhao Jijun
Published: October 2020

One of the major challenges for the GaN-based high-electron-mobility transistors (HEMTs) used as high power devices is to understand the effect of defects, especially on the band alignment. Using ab initio calculation, herein we investigate the variations of band offsets with interfacial structure, defect position, interface states and Al content in Al
x
Ga1-x
N/GaN heterostructures (x = 0.06, 0.13, 0.19, 0.25). It was found that N vacancy (VN) and Ga anti-site (GaN) introduce nonlocal interface states and the change of valence band offset (VBO) depends on the defect location. While the interface states induced by Ga vacancy (VGa) and N anti-site (NGa) show strong localization behavior, and their impact on VBO is independent on the defect position. The low symmetry of wurtzite nitride and the lattice mismatch between AlGaN and GaN will generate polarization charge (spontaneous polarization and piezoelectric polarization) at the interface. Along the direction of polarization field, VN and GaN lying in the AlGaN side change the VBO most pronouncedly. These theoretical results provide useful guidance for control of point defects in AlGaN/GaN HEMTs, which have profound impact on the performance and reliability of GaN-based devices.
Photostability enhancement of InP/ZnSe/ZnSeS/ZnS quantum dots by plasmonic nanostructures
Authors: Kulakovich O , Gurinovich L , Li Hui , Ramanenka A , Trotsiuk L , Muravitskaya A , Wei Jing , Li Hongbo , Matveevskaya N , Guzatov D V , Gaponenko S
Published: October 2020

The effect of gold and silver plasmonic films on the photoluminescence and photostability of InP/ZnSe/ZnSeS/ZnS nanocrystals (quantum dots) is reported. Colloidal gold films promote the photostability enhancement of InP/ZnSe/ZnSeS/ZnS quantum dots (more durable emission properties in the presence of metal nanostructures) through reducing exciton lifetime. In contrast, silver decreases the photostability of InP/ZnSe/ZnSeS/ZnS quantum dots without changing the photoluminescence intensity and kinetics. By adjusting the excitation wavelength closer to the extinction band of gold nanoparticles a 1.8-fold enhancement of luminescence intensity has been obtained using a polyelectrolyte spacer between the metal and InP/ZnSe/ZnSeS/ZnS nanoparticles. Thus, plasmonics offers essential practical improvement of light emitters in terms of their durable luminescent properties upon prolonged optical excitation without losses in luminescence efficiency or even along with increased efficiency.
Video analysis of one-dimensional multi-body collisions: linear momentum, impulse and energy
Authors: Yamil Risk Mora David , Durango Idárraga Sebastián , César Cárdenas Montoya Paulo
Published: October 2020

Collisions are a key topic in physics and engineering education. An experiment with multiple body one-dimensional collisions is presented, aiming to measure relevant physical quantities by tracking the motion of the system of particles during the collision. Relations between different physical quantities can be explored in the experiment, such as linear momentum, impulse, and energy. Equations are presented for modeling velocity changes during the collisions under the elastic and inelastic conditions and extensions to many body colliders can be easily implemented. Predictions for the velocities and other collision quantities were verified for a set of mass parameters by photogrammetry and digital video analysis.
Designing inquiry-based learning environments for quantum physics education in secondary schools
Authors: Vilarta Rodriguez Luiza , van der Veen Jan T , Anjewierden Anjo , van den Berg Ed , de Jong Ton
Published: October 2020

This paper describes the design process for a digital instructional sequence on introductory quantum physics for upper secondary education. Based on a collaboration between teachers and physics education researchers, this sequence incorporates relevant theoretical foundations from the field of science teaching to promote meaningful and conceptual learning of quantum physics. The sequence is composed of units, which are being developed using the Go-Lab ecosystem (www.golabz.eu), a free online platform for teachers to create digital inquiry-based lessons. So far, the sequence covers the photoelectric effect, wave-particle duality, and tunnelling phenomena. This paper focuses on the sequence’s first unit, addressing the photoelectric effect. The unit is used in this paper to exemplify the incorporation of the sequence’s theoretical foundations: digital inquiry-based learning with simulations, collaborative learning, and conceptual change. The unit was pilot-tested with 114 students in four Dutch high schools. Answers to multiple-choice and open-ended questions were collected through the Go-Lab platform. Analyses showed the unit’s potential to promote correct reasoning about the role of the intensity and frequency variables and revealed students’ difficulties in grasping light’s particle nature at the end of the lesson. These preliminary results are used to draw conclusions about how to improve this unit and inform the design of new instructional sequences.
Assessment of absorbed power density and temperature rise for nonplanar body model under electromagnetic exposure above 6 GHz
Authors: Diao Yinliang , Rashed Essam A , Hirata Akimasa
Published: October 2020

The averaged absorbed power density (APD) and temperature rise in body models with nonplanar surfaces were computed for electromagnetic exposure above 6 GHz. Different calculation schemes for the averaged APD were investigated. Additionally, a novel compensation method for correcting the heat convection rate on the air/skin interface in voxel human models was proposed and validated. The compensation method can be easily incorporated into bioheat calculations and does not require information regarding the normal direction of the boundary voxels, in contrast to a previously proposed method. The APD and temperature rise were evaluated using models of a two-dimensional cylinder and a three-dimensional partial forearm. The heating factor, which was defined as the ratio of the temperature rise to the APD, was calculated using different APD averaging schemes. Our computational results revealed different frequency and curvature dependences. For body models with curvature radii of >30 mm and at frequencies of >20 GHz, the differences in the heating factors among the APD schemes were small.
Predictive dose accumulation for HN adaptive radiotherapy
Authors: Lee Donghoon , Zhang Pengpeng , Nadeem Saad , Alam Sadegh , Jiang Jue , Caringi Amanda , Allgood Natasha , Aristophanous Michalis , Mechalakos James , Hu Yu-Chi
Published: October 2020

During radiation therapy (RT) of head and neck (HN) cancer, the shape and volume of the parotid glands (PG) may change significantly, resulting in clinically relevant deviations of delivered dose from the planning dose. Early and accurate longitudinal prediction of PG anatomical changes during the RT can be valuable to inform decisions on plan adaptation. We developed a deep neural network for longitudinal predictions using the displacement fields (DFs) between the planning computed tomography (pCT) and weekly cone beam computed tomography (CBCT). Sixty-three HN patients treated with volumetric modulated arc were retrospectively studied. We calculated DFs between pCT and week 1–3 CBCT by B-spline and Demon deformable image registration (DIR). The resultant DFs were subsequently used as input to our novel network to predict the week 4 to 6 DFs for generating predicted weekly PG contours and weekly dose distributions. For evaluation, we measured dice similarity (DICE), and the uncertainty of accumulated dose. Moreover, we compared the detection accuracies of candidates for adaptive radiotherapy (ART) when the trigger criteria were mean dose difference more than 10%, 7.5%, and 5%, respectively. The DICE of ipsilateral/contralateral PG at week 4 to 6 using the prediction model trained with B-spline were 0.81

±

0.07/0.81

±

0.04 (week 4), 0.79

±

0.06/0.81

±

0.05 (week 5) and 0.78

±

0.06/0.82

±
 
0.02

(week 6). The DICE with the Demons model were 0.78

±

0.08/0.82

±

0.03 (week 4), 0.77

±

0.07/0.82

±

0.04 (week 5) and 0.75

±

0.07/0.82

±

0.02 (week 6). The dose volume histogram (DVH) analysis with the predicted accumulated dose showed the feasibility of predicting dose uncertainty due to the PG anatomical changes. The AUC of ART candidate detection with our predictive model was over 0.90. In conclusion, the proposed network was able to predict future anatomical changes and dose uncertainty of PGs with clinically acceptable accuracy, and hence can be readily integrated into the ART workflow.
Investigation of air-stable Cs2SnI6 films prepared by the modified two-step process for lead-free perovskite solar cells
Authors: Ullah Saad , Ullah Sami , Wang Jiaming , Yang Shi-E , Xia Tianyu , Guo Haizhong , Chen Yongsheng
Published: October 2020

In recent years, the organic-inorganic perovskite materials have revolutionized the Photovoltaic industry with highly efficient power conversion devices accompanied by a high growth rate. However, these devices experience major environmental and stability issues that hinder their true potential. More recently, a rarely studied perovskite material Cs2SnI6 is gaining enormous attention due to its superior stability and suitable bandgap. In this work, we developed a modified two-step process to prepare uniform Cs2SnI6 films, and the influence of the reaction conditions on the properties is explored. The structural, morphological, optical, and electrical properties of the prepared films were investigated using x-ray diffraction, Raman spectroscopy, scanning electron microscopy, UV–vis spectrometer, photoluminescence, and Hall Effect measurements, respectively. Phase stability and morphology of the films are improved with optimizing the reaction conditions. The results confirm the n-type semiconductor nature of Cs2SnI6 with bandgap ranging from 1.29 eV to 1.42 eV with maximum carrier mobility of 425 cm2 V−1 s−1. The present study will further provide potential research directions in improving the device efficiency of air-stable Cs2SnI6 perovskite solar cells.
3D spacer fabrics for thermoelectric textile cooling and energy generation based on aluminum doped zinc oxide
Authors: Schmidl G , Gawlik A , Jia G , Andrä G , Richter K , Plentz J
Published: October 2020

It is demonstrated that spacer fabrics made of polyester can be coated with Al-doped ZnO (AZO) as thermoelectric (TE) material and conductive silver as contact material to enable smart textiles. An atomic layer deposition process was used for the AZO coating and the conductive silver paste was manually applied. A TE generator and cooling based on the Seebeck and Peltier effect can be observed if a temperature difference or direct current is applied, respectively. Both effects were proven to exist and evaluated. The Seebeck coefficient was determined of up to 50 µV · K−1 and a TE power of about 0.2 µW was generated. Without additional active heat dissipation or cooling, a temperature difference between both spacer fabric surfaces of up to 12 K was achieved. By changing the polarity of the electrical contacts it can significantly be shown that the cold-warm side is changed, as expected for a Peltier element. We observed experimentally the Peltier effect using a single element as well as electrically interconnected sample pairs, the latter could be important for the cooling application. Additionally, the heat transport through the spacer fabrics was tested and showed that there is no heat equalization between the surfaces via air and filaments at temperatures up to 50 °C. The Peltier effect as a fundamental TE effect, that enables site-specific and on-demand cooling applications, has not yet been comprehensively investigated using spacer fabrics and AZO as TE material. These investigations predict that AZO on spacer fabrics hold the special potential to enable flexible and textile solid-state cooling applications.
Numerical simulation of vertical mold casting temperature field of copper anode plates
Authors: Zhang Fangping , Xiang Zheng , Cao Yu
Published: October 2020

As an important raw material for refining copper by electrolysis, copper anode plates are mainly manufactured by disc casting machine. However, those copper anode plates frequently have such defects as uneven thickness, broken lugs, porosity inside plates, and low production efficiency and low yield rate, failing to meet the demands of electrolysis for the quality and quantity of anode plates. To develop a new vertical mold casting process for copper anode plates and study the influence of cooling on the life of the machine during vertical mold casting, two design schemes of cooling channels for the high-temperature working mode of copper anode plate production were put forward in this paper, and ANSYS was introduced to simulate and analyze the flow state, flow rate and temperature field of the cooling water. The results indicated that the vertical mold with the double-cycle cooling channel is about 2 °C lower than that with the single-cycle cooling channel. The temperature of the former at point A outside and point B near the lug inside the vertical mold is 20 °C–30 °C higher than that of the latter. The temperature of vertical mold casting copper anode plates with double-cycle cooling channel is below 700 °C when casting for 50 s, suggesting that the copper anode plates have more uniform temperature and higher cooling efficiency with the double-cycle cooling channel, which can prolong the service life of the casting machine. The research results lay a theoretical foundation for the manufacture of copper anode plates and the improved design of the copper vertical mold casting machine.
A GWAS approach to find SNPs associated with salt removal in rice leaf sheath
Authors: Neang Sarin , de Ocampo Marjorie , Egdane James A , Platten John Damien , Ismail Abdelbagi M , Seki Masahide , Suzuki Yutaka , Skoulding Nicola Stephanie , Kano-Nakata Mana , Yamauchi Akira , Mitsuya Shiro
Published: October 2020

Background and Aims

The ability for salt removal at the leaf sheath level is considered to be one of the major mechanisms associated with salt tolerance in rice. Thus, understanding the genetic control of the salt removal capacity in leaf sheaths will help improve the molecular breeding of salt-tolerant rice varieties and speed up future varietal development to increase productivity in salt-affected areas. We report a genome-wide association study (GWAS) conducted to find single nucleotide polymorphisms (SNPs) associated with salt removal in leaf sheaths of rice.

Methods

In this study, 296 accessions of a rice (Oryza sativa) diversity panel were used to identify salt removal-related traits and conduct GWAS using 36 901 SNPs. The sheath:blade ratio of Na+ and Cl– concentrations was used to determine the salt removal ability in leaf sheaths. Candidate genes were further narrowed via Gene Ontology and RNA-seq analysis to those whose putative function was likely to be associated with salt transport and were up-regulated in response to salt stress.

Key results

For the association signals of the Na+ sheath:blade ratio, significant SNPs were found only in the indica sub-population on chromosome 5. Within candidate genes found in the GWAS study, five genes were upregulated and eight genes were downregulated in the internal leaf sheath tissues in the presence of salt stress.

Conclusions

These GWAS data imply that rice accessions in the indica variety group are the main source of genes and alleles associated with Na+ removal in leaf sheaths of rice under salt stress.
The Effects of Cannabis Use on Cognitive Function in Healthy Aging: A
Systematic Scoping Review
Authors: Pocuca Nina , Walter T Jordan , Minassian Arpi , Young Jared W , Geyer Mark A , Perry William
Published: October 2020

Background

Older adults (≥50 years) represent the fastest-growing population of people who use cannabis, potentially due to the increasing promotion of cannabis as medicine by dispensaries and cannabis websites. Given healthy aging and cannabis use are both associated with cognitive decline, it is important to establish the effects of cannabis on cognition in healthy aging.

Objective

This systematic scoping review used preferred reporting items for systematic reviews and meta-analyses guidelines to critically examine the extent of literature on this topic and highlight areas for future research.

Method

A search of six databases (PubMed, EMBASE, PsycINFO, Web of Science, Family and Society Studies Worldwide, and CINAHL) for articles published by September 2019, yielded 1,014 unique results.

Results

Six articles reported findings for older populations (three human and three rodent studies), highlighting the paucity of research in this area. Human studies revealed largely null results, likely due to several methodological limitations. Better-controlled rodent studies indicate that the relationship between ∆9-tetrahydrocannabinol (THC) and cognitive function in healthy aging depends on age and level of THC exposure. Extremely low doses of THC improved cognition in very old rodents. Somewhat higher chronic doses improved cognition in moderately aged rodents. No studies examined the effects of cannabidiol (CBD) or high-CBD cannabis on cognition.

Conclusions

This systematic scoping review provides crucial, timely direction for future research on this emerging issue. Future research that combines neuroimaging and cognitive assessment would serve to advance understanding of the effects of age and quantity of THC and CBD on cognition in healthy aging.
Tremor in Parkinson's disease inverts the effect of dopamine on reinforcement
Authors: Manohar Sanjay G
Published: October 2020

This scientific commentary refers to ‘Effects of dopamine on reinforcement learning in Parkinson’s disease depend on motor phenotype’ by van Nuland et al. (doi:10.1093/brain/awaa335).