bluuebunny/crossref_metadata_2025 huggingface dataset:
Toward improved human health: efficacy of dietary selenium on immunity at the cellular level
Authors: Xia Xiaojing , Zhang Xiulin , Liu Mingcheng , Duan Mingyuan , Zhang Shanshan , Wei Xiaobing , Liu Xingyou
Published: December 2020

Selenium, an essential trace element in the body, participates in various biological processes in the form of selenoproteins.
Insights into the electrochemical degradation of phenolic lignin model compounds in a protic ionic liquid–water system
Authors: Liu Guangyong , Wang Qian , Yan Dongxia , Zhang Yaqin , Wang Chenlu , Liang Shijing , Jiang Lilong , He Hongyan
Published: December 2020

Electrochemical degradation mechanism of phenolic lignin model compounds with typical Caryl–O bond in a protic IL-water system is clarified, including direct oxidation of substrates at the electrode and indirect oxidation by in situ generated H2O2.
Colloidal BaZrS3 chalcogenide perovskite nanocrystals for thin film device fabrication
Authors: Ravi Vikash Kumar , Yu Seong Hoon , Rajput Parikshit Kumar , Nayak Chandrani , Bhattacharyya Dibyendu , Chung Dae Sung , Nag Angshuman
Published: December 2020

Surface modification of BaZrS3 nanocrystals for colloidal dispersions and field effect transistors. A rare example of solution processed chalcogenide perovskite thin films.
Effect of annealing on the defect-mediated blue phosphorescence in ZnO nanocrystals
Authors: Das Sagnik , Ghorai Uttam Kumar , Dey Rajib , Ghosh Chandan Kumar , Pal Mrinal
Published: December 2020

We observed and analyzed the effect of thermal annealing on the point defect concentration and in turn on the defect mediated blue phosphorescence in nanocrystalline ZnO.
Characterizing hydrogen bonds in crystalline form of guanidinium salicylate in the terahertz range
Authors: Song Maojiang , Yang Fei , Su Caixia , Deng Bing
Published: December 2020

For pharmaceutical compounds with poor solubility, there is an effective method to address this dilemma without tampering their intrinsic chemical properties by forming weak hydrogen bonds.
Recent trends in the direct oxyphosphorylation of C–C multiple bonds
Authors: Bakhtiary Alireza , Poor Heravi Mohammad Reza , Hassanpour Akbar , Amini Issa , Vessally Esmail
Published: December 2020

Due to the wide importance of β-phosphorylated ketones as key building-blocks in the fabrication of various pharmaceutically active organophosphorus compounds, finding new and truly efficient methods for their preparation.
Excellent humidity sensor based on ultrathin HKUST-1 nanosheets
Authors: Wang Qiaoe , Lian Meiling , Zhu Xiaowen , Chen Xu
Published: December 2020

An excellent humidity sensor based on ultrathin HKUST-1 nanosheets was developed and some insights for the morphology–activity relationship were provided.
Design, synthesis and application in biological imaging of a novel red fluorescent dye based on a rhodanine derivative
Authors: Li Zijing , Huang Bin , Wang Yuan , Yuan Wenbo , Wu Yijing , Yu Ruitao , Xing Guichuan , Zou Taotao , Tao Youtian
Published: December 2020

2RDNTPA can be applied in fluorescence imaging of living cancer cells (HepG2) with red emission of 620 nm and negligible cytotoxicity with a half maximal inhibitory concentration much more than 100 μM.
Recovery of valuable metals from mixed spent lithium-ion batteries by multi-step directional precipitation
Authors: Yang Xuan , Zhang Yingjie , Meng Qi , Dong Peng , Ning Peichao , Li Qingxiang
Published: December 2020

Recovery of valuable metals from the leachate of cathode material mechanically separated from mixed spent lithium-ion batteries by sequential precipitation.
Vesicular systems for dermal and transdermal drug delivery
Authors: Richard Claire , Cassel Stéphanie , Blanzat Muriel
Published: December 2020

Dermal/transdermal drug delivery continues to grow in importance as a means of enhancing treatment activity while reducing toxicity by avoiding the systemic absorption of the drug.
Effect of modulator connectivity on promoting defectivity in titanium–organic frameworks
Authors: Lázaro Isabel Abánades , Almora-Barrios Neyvis , Tatay Sergio , Martí-Gastaldo Carlos
Published: December 2020

The connectivity of mono- and dicarboxylic modulators controls their ability to promote defects in the titanium framework MUV-10.
Polymeric one-side conductive Janus separator with preferably oriented pores for enhancing lithium metal battery safety
Authors: Xu Lulu , Daphne Ma Xiu Yun , Wang Wei , Liu Jian , Wang Zhe , Lu Xuehong
Published: December 2020

The electrically conductive surface and aligned pores of a separator could effectively promote the safety and enhance the electrochemical performance of LMBs.
Poly(vinylidene fluoride)-passivated CsPbBr3 perovskite quantum dots with near-unity photoluminescence quantum yield and superior stability
Authors: Yang Lin , Fu Bowen , Li Xu , Chen Hao , Li Lili
Published: December 2020

A passivation strategy was demonstrated for CsPbBr3 QDs with an α-PVDF ligand, which could suppress phase transformation and enhance optical performance.
Investigation on the photoluminescence and thermoluminescence of BaGa2O4:Bi3+ at extremely low temperatures
Authors: Li Huimin , Wu Haiyan , Pang Ran , Liu Guanyu , Zhang Su , Jiang Lihong , Li Da , Li Chengyu , Feng Jing , Zhang Hongjie
Published: December 2020

The photoluminescence and long persistent luminescence of BaGa2O4:Bi3+ at extremely low temperatures have been systematically investigated.
Is infrasound perceived by the auditory system through distortions?
Authors: Joost Holger , Friedrich Björn , Verhey Jesko L. , Fedtke Thomas
Published: December 2020

Several studies showed that the human auditory system is sensitive to infrasound. The present study investigated if non-linear processes within the ear generate distortion products, which may explain the auditory sensitivity to infrasound. Pure-tone infrasound stimuli were presented to the ears of 16 listeners with a low-distortion sound reproduction system via an ear insert. Simultaneously, the sound in the ear canal was recorded with a high-sensitivity probe microphone. In addition, detection thresholds in quiet for these stimuli were determined in all listeners. All of the listeners showed distortion products, which were detected by analyzing the sound recorded in their ear canals during infrasound stimulation, for at least one of the signal frequencies. The sound pressure levels of the distortion products were well below the reference thresholds at the corresponding frequencies. For each signal frequency, the listeners’ detection thresholds in cases with ear-generated distortion products did not differ significantly from those in cases without. Thus, the present data do not support the hypothesis that distortion products play a major role in the auditory perception of infrasound.
Multivariate models for monitoring the environmental performance of gasoline
Authors: Kovalenko V. V. , Loginov V. S. , Lyzlova M. V. , Melnik G. I. , Trunkin D. S. , Shuvarikova T. P.
Published: December 2020

A linear multivariate regression model for the IR spectra of gasolineare used in the paper. On the basis of a number of test samples (alkylate, reformate, regular, premium), an equation was obtained for calculating the content of aromatic hydrocarbons in gasolines based on the transmission values at wave numbers: 1600, 1500, 870, 810, 750 cm-1. The calculated equation was tested on a series of regular gasolines and by the cross-validation method. The test results showed good values of the correlation coefficient (0,96) and the standard deviation (0,4 and 3,5). The range of the content of aromatic hydrocarbons in the test samples is in the range of 24,9 - 30,5 mass %.
Improving the efficiency of the hybrid algorithm for solving inhomogeneous minimax problem
Authors: Kobak V , Zhukovskiy A , Porksheyan V , Kuzin A
Published: December 2020

The article deals with the problem of inhomogeneous minimax problem solution, what is typical of scheduling theory. This problem is NPcomplete, and there is no exact algorithm for it, which has a polynomial time for large-scale problems. Therefore a quick algorithm that gets approximate tables is used. A possible method for solving this problem is considered a hybrid model, representing the synthesis of two genetic algorithms models, namely models Goldberg and CGS. Goldberg’s model is viewed from multiple crossovers and most promising mutation. As it is difficult to make calculations analytically and often impossible to make it in practice, the computational experiment was carried out in this article. The results of the experiment are described in the tables, which graphically show a comparison of the hybrid model effectiveness. The comparison is based on the accuracy results obtained for two types of crossovers with the basic parameters of genetic algorithm. It is proved that the use of hybrid algorithm leads to the results which are more précised to the optimal ones, despite the deterioration in the temporary search characteristics solutions.
Application of the transfer learning to the medical images texture classification task
Authors: Privalov M , Stupina M
Published: December 2020

This study is conducted to determine effectiveness and perspectives of application of the transfer learning approach to the medical images classification task. There are a lot of medical studies that involve image acquisition, such as XRay radiography, ultrasonic scanning, computer tomography (CT), magnetic resonance imaging (MRI) etc. Besides those medical procedures there are different operations that use medical images processing including but not limited to digital radiograph reconstruction (DRR), radiotherapy planning, brachy therapy planning. All those tasks could be effectively performed with help of software capable to perform segmentation, classification and object recognition. Those capabilities are naturally depend on neural classifiers. Presented work investigates different approaches to solving image classification task with neural networks, specifically, using pre-processing for feature extraction and end-to-end application of convolutional neural networks (CNN). Due to requirement of significantly big datasets and large computing power CNNs sometimes may appear difficult to train, so our results pay attention to application of transfer learning technique that can potentially relax requirements to classifier training. The conclusions of this study state that transfer learning can be effectively used for classification tasks, especially texture classification.
2-aryl-5-pyrrolecarboxylic acid methyl ester synthesis modeling and optimization based on kinetic model
Authors: Akhmetov I
Published: December 2020

In this work, a kinetic model of the 2-aryl-5-pyrrolecarboxylic acid methyl ester synthesis is constructed. Computational experiments to optimize the reaction have been carried out. The reaction conditions for obtaining the maximum yield of the target product were determined.
Digitalization of housing and communal services using the example of apartment buildings
Authors: Smirnov M.Yu. , Ziyautdinov V.S. , Voronin I.V. , Zolotareva T.A.
Published: December 2020

The possibility of digitalization of housing and communal services is mathematically considered using the example of apartment buildings. The approaches discussed in the paper can be used in the construction of new apartment complexes, as well as in the overhaul of the existing housing stock. In addition, the applied approaches can be easily adapted for use in office buildings and business centers.
Creation and study of raw material for grain sorghum breeding
Authors: Vertikova E. A. , Zhuzhukin V I , Pylnev V V , Kurasova L G
Published: December 2020

For the arid zone of the Lower Volga region, grain sorghum is an important forage crop. The paper presents the results of a comparative assessment of grain yield and biomass of breeding lines of grain sorghum in the nursery of preliminary variety testing. The volume of the nursery for the preliminary variety testing was 117 breeding lines. The most productive were the breeding lines of grain sorghum, the grain yield of which reached 3.95 t / ha (line PSI-17 / EV-56); 4.10 t / ha (line PSI-17 / EV-113); 4.15 t / ha (line PSI-17 / EV-55); 4.50 t / ha (line PSI-17 / EV-92) with a yield of 3.75 t / ha of the standard variety Volzhskoe 4. As a result of scientific research, the promising breeding lines of grain sorghum were identified: PSI-17 / EV-56 and PSI-17 / EV-92, which were recommended to be submitted for competitive variety testing. It is advisable to use the breeding line of grain sorghum PSI-17 / EV-54V for early maturity. The breeding lines of grain sorghum: PSI-17 / EV-56 and PSI-17 / EV-90 are planned to be included in crosses to create varieties and hybrids with high grain quality. Breeding lines of grain sorghum: PSI-17 / EV-50, PSI-17 / EV-54, PSI-17 / EV-92 and PSI-17 / EV-127 are planned to be used in breeding for biomass yield.
Role of industrial cooperation and inter-cluster interaction in the development of localization of production in shipbuilding
Authors: Serbulov Alexey , Shaliapina Marina
Published: December 2020

An effective tool that allows you to dampen economic losses from the Western sanctions imposed on our country is the development of international cooperation and the associated processes of localization of production. However, along with the positive effect, there are a number of administrative and organizational problems that impede the expected results from both foreign partners and domestic manufacturers. On the example of the shipbuilding industry, the problems of further development of inter-cluster interaction are shown both at the national and international levels. It is shown how participation in the formation of the Panel of Equipment Suppliers, which is an extensive computer system for managing procurement activities and material and technical supply of shipyards, will expand the opportunities for foreign companies to participate in the implementation of large-scale government orders.
A 3-min All-out Upper-body Ergometer Test For Competitive Swimmers
Authors: Nordsborg Nikolai Baastrup , Aragón-Vela Jerónimo , Bonne Thomas , Mohr Magni
Published: December 2020

We examined the application of a land-based swimming ergometer 3-min all-out test to determine physiological predictors of swimming performance. Fourteen young elite swimmers participated (males: n=6; females: n=8). The swimmers completed two 3-min upper-body all-out tests on a swimming ergometer. Additionally, the swimmers completed freestyle swim races ranging from 50 m to 1500 m. High test-retest reproducibility (r=0.98 and coefficient of variation values <7.5%) was evident for ergometer derived peak, mean and critical power. Very strong correlations (r>0.87, p<0.001) were obtained between the 200-, 400-, 800- and 1500-m swimming performances and derived critical speed. Moreover, correlations were found between peak force and peak power and 50-m performance, in addition to critical power and performance for all distances. The critical speed was the dominant predictor of 200- to 1500-m performances (r=0.84−0.99). In conclusion, the land-based 3-min all-out swimming ergometer test is reliable and valid in predicting swimming performance in competitive swimmers and evaluates important physiological components in swimmers independent of technical abilities.
Mechanisms of Bone Remodeling Disorder in Hemophilia
Authors: Wang Hanshi , Bai Xizhuang
Published: December 2020

Hemophilia is caused by a lack of antihemophilic factor(s), for example, factor VIII (FVIII; hemophilia A) and factor IX (FIX; hemophilia B). Low bone mass is widely reported in epidemiological studies of hemophilia, and patients with hemophilia are at an increased risk of fracture. The detailed etiology of bone homeostasis imbalance in hemophilia is unclear. Clinical and experimental studies show that FVIII and FIX are involved in bone remodeling. However, it is likely that antihemophilic factors affect bone biology through thrombin pathways rather than via their own intrinsic properties. In addition, among patients with hemophilia, there are pathophysiological processes in several systems that might contribute to bone loss. This review summarizes studies on the association between hemophilia and bone remodeling, and might shed light on the challenges facing the care and prevention of osteoporosis and fracture in patients with hemophilia.
Clinical Decision Support System with Renal Dose Adjustment Did Not Improve Subsequent Renal and Hepatic Function among Inpatients: The Japan Adverse Drug Event Study
Authors: Wada Ryuhei , Takeuchi Jiro , Nakamura Tsukasa , Sonoyama Tomohiro , Kosaka Shinji , Matsumoto Chisa , Sakuma Mio , Ohta Yoshinori , Morimoto Takeshi
Published: December 2020

Background Medication dose adjustment is crucial for patients with renal dysfunction (RD). The assessment of renal function is generally mandatory; however, the renal function may change during the hospital stay and the manual assessment is sometimes challenging.

Objective We developed the clinical decision support system (CDSS) that provided a recommended dose based on automated calculated renal function.

Methods We conducted a prospective cohort study in a single teaching hospital in Japan. All hospitalized patients were included except for obstetrics/gynecology and pediatric wards between September 2013 and February 2015. The CDSS was implemented on December 2013. Renal and hepatic dysfunction (HD) were defined as changes in the estimated glomerular filtration rate (eGFR) and alanine aminotransferase or alkaline phosphatase levels based on these measurements during hospital stay. These measurements were obtained before (phase I), after (phase II), and 1 year after (phase III) the CDSS implementation.

Results We included 6,767 patients (phase I: 2,205; phase II: 2,279; phase III: 2,283). The patients' characteristics were similar among phases. Changes in eGFR were similar among phases, but the incidence of RD increased in phase III (phase I: 228 [10.3%]; phase II: 260 [11.4%]; phase III: 296 [13.0%], p = 0.02). However, the differences in incidences of RD were not statistically significant after adjusting for eGFR at baseline and age. The incidences of HD were also similar among phases (phase I: 175 [13.2%]; phase II: 171 [12.9%]; phase III: 167 [12.2%], p = 0.72).

Conclusion The CDSS implementation did not affect the incidence of renal and HD and changes in renal and hepatic function among hospitalized patients. The effectiveness of the CDSS with renal-guided doses should be investigated with respect to other endpoints.
Heparin Inhibits Cellular Invasion by SARS-CoV-2: Structural Dependence of the Interaction of the Spike S1 Receptor-Binding Domain with Heparin
Authors: Mycroft-West Courtney J. , Su Dunhao , Pagani Isabel , Rudd Timothy R. , Elli Stefano , Gandhi Neha S. , Guimond Scott E. , Miller Gavin J. , Meneghetti Maria C. Z. , Nader Helena B. , Li Yong , Nunes Quentin M. , Procter Patricia , Mancini Nicasio , Clementi Massimo , Bisio Antonella , Forsyth Nicholas R. , Ferro Vito , Turnbull Jeremy E. , Guerrini Marco , Fernig David G. , Vicenzi Elisa , Yates Edwin A. , Lima Marcelo A. , Skidmore Mark A.
Published: December 2020

The dependence of development and homeostasis in animals on the interaction of hundreds of extracellular regulatory proteins with the peri- and extracellular glycosaminoglycan heparan sulfate (HS) is exploited by many microbial pathogens as a means of adherence and invasion. Heparin, a widely used anticoagulant drug, is structurally similar to HS and is a common experimental proxy. Exogenous heparin prevents infection by a range of viruses, including S-associated coronavirus isolate HSR1. Here, we show that heparin inhibits severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) invasion of Vero cells by up to 80% at doses achievable through prophylaxis and, particularly relevant, within the range deliverable by nebulisation. Surface plasmon resonance and circular dichroism spectroscopy demonstrate that heparin and enoxaparin, a low-molecular-weight heparin which is a clinical anticoagulant, bind and induce a conformational change in the spike (S1) protein receptor-binding domain (S1 RBD) of SARS-CoV-2. A library of heparin derivatives and size-defined fragments were used to probe the structural basis of this interaction. Binding to the RBD is more strongly dependent on the presence of 2-O or 6-O sulfate groups than on N-sulfation and a hexasaccharide is the minimum size required for secondary structural changes to be induced in the RBD. It is likely that inhibition of viral infection arises from an overlap between the binding sites of heparin/HS on S1 RBD and that of the angiotensin-converting enzyme 2. The results suggest a route for the rapid development of a first-line therapeutic by repurposing heparin and its derivatives as antiviral agents against SARS-CoV-2 and other members of the Coronaviridae.
Additional Heart Sounds–Part 2 (Clicks, Opening Snap and More)
Authors: Nemani Lalita , Pechetty Ramya
Published: December 2020

Systolic clicks are high-pitched sharp sounds. They are classified as ejection and nonejection clicks. Ejections clicks commonly occur at the aortic and pulmonary valve, while nonejection clicks occur at the mitral and tricuspid valve.

Opening snap is an additional sound heard in the diastole. It is described as an early diastolic, high-pitched sound, which is associated with opening of the mitral and/or tricuspid valve.

Pericardial knock is a high-pitched early diastolic sound, which is characteristic of constrictive pericarditis.

The opening and closing of prosthetic valves produce sounds which may vary in intensity and timing according to the type and design of the valve, patient’s rhythm, and hemodynamic status.
Heat flow and noncommutative quantum mechanics in phase-space
Authors: Santos Jonas F. G.
Published: December 2020

The complete understanding of thermodynamic processes in quantum scales is paramount to develop theoretical models encompassing a broad class of phenomena as well as to design new technological devices in which quantum aspects can be useful in areas such as quantum information and quantum computation. Among several quantum effects, the phase-space noncommutativity, which arises due to a deformed Heisenberg–Weyl algebra, is of fundamental relevance in quantum systems where quantum signatures and high energy physics play important roles. In low energy physics, however, it may be relevant to address how a quantum deformed algebra could influence some general thermodynamic protocols, employing the well-known noncommutative quantum mechanics in phase-space. In this work, we investigate the heat flow of two interacting quantum systems in the perspective of noncommutativity phase-space effects and show that by controlling the new constants introduced in the quantum theory, the heat flow from the hot to the cold system may be enhanced, thus decreasing the time required to reach thermal equilibrium. We also give a brief discussion on the robustness of the second law of thermodynamics in the context of noncommutative quantum mechanics.
Trajectory of a flying plasma mirror traversing a target with density gradient
Authors: Chen Pisin , Mourou Gerard
Published: December 2020

It has been proposed that laser-induced relativistic plasma mirror can accelerate if the plasma has a properly tailored density profile. Such accelerating plasma mirrors can serve as analog black holes to investigate Hawking evaporation and the associated information loss paradox. Here we reexamine the underlying dynamics of mirror motion in a graded-density plasma to provide an explicit trajectory as a function of the plasma density and its gradient. Specifically, a decreasing plasma density profile (down-ramp) along the direction of laser propagation would in general accelerate the mirror. In particular, a constant-plus-exponential density profile would generate the Davies–Fulling trajectory with a well-defined analog Hawking temperature, which is sensitive to the plasma density gradient but not to the density itself. We show that without invoking nano-fabricated thin-films, a much lower density gas target at, for example, ∼1×1017cm−3, would be able to induce an analog Hawking temperature, kBTH∼3.1×10−2eV, in the far-infrared region. We hope that this would help to better realize the experiment proposed by Chen and Mourou.
Fluctuations in the number of nodal domains
Authors: Nazarov Fedor , Sodin Mikhail
Published: December 2020

We show that the variance of the number of connected components of the zero set of the two-dimensional Gaussian ensemble of random spherical harmonics of degree n grows as a positive power of n. The proof uses no special properties of spherical harmonics and works for any sufficiently regular ensemble of Gaussian random functions on the two-dimensional sphere with distribution invariant with respect to isometries of the sphere. Our argument connects the fluctuations in the number of nodal lines with those in a random loop ensemble on planar graphs of degree four, which can be viewed as a step toward justification of the Bogomolny–Schmit heuristics.
A mechanistic investigation of moisture-induced degradation of methylammonium lead iodide
Authors: Hada Masaki , Abdullah Al Asad Md. , Misawa Masaaki , Hasegawa Yoichi , Nagaoka Ryota , Suzuki Hiroo , Mishima Ryuji , Ota Hiromi , Nishikawa Takeshi , Yamashita Yoshifumi , Hayashi Yasuhiko , Tsuruta Kenji
Published: December 2020

We performed in situ x-ray diffraction (XRD) experiments on an inorganic–organic hybrid perovskite, CH3NH3PbI3 (MAPbI3), during its interaction with moisture to understand the degradation mechanism. Although the degradation of inorganic–organic hybrid perovskite is an important factor hampering their development as solar cell materials, understanding of the degradation process is currently limited. The moisture-induced degradation mechanism was revealed by the temperature dependence of the in situ XRD pattern sequences and first-principles calculations based on the nudged elastic band method. The combination of experimental and computational data suggests that the MAPbI3 crystal spontaneously changes into the MAPbI3 mono-hydrate crystal once water molecules activated with an energy of more than ∼0.6 eV penetrate the (100) outer surface of the MAPbI3 lattice. These findings have important implications for the development of more robust inorganic–organic hybrid perovskites as light absorbing layers in solar cells and other applications.
Multi-channel fiber optical spectrometer for high-throughput characterization of photoluminescence properties
Authors: Zhou Zhenzhen , Liu Qian , Fu Yanwen , Xu Xiaoke , Wang Caiyan , Deng Mingxue
Published: December 2020

High-throughput experiment can significantly accelerate the materials research efficiency. Thanks to national efforts, the Materials Genome Initiative further promotes the development of high-throughput experimental technology. A multi-channel fiber optical spectrometer has been designed and developed by us for high-throughput characterization of photoluminescence (PL) properties. It can quickly and automatically detect the PL spectrum, Commission International de l’Eclairage chromaticity, and PL intensity over time for luminescent materials under a given condition. The multi-channel fiber optical spectrometer synergistically combines a sample library holder, multiple modular excitation sources, multiple spectrometers, and Coral software, so it can measure and analyze multiple samples simultaneously. The number of channels in the multi-channel fiber optical spectrometer can be added or subtracted as required. Various modular light-emitting diode or laser diode excitation sources with the wavelength from 370 nm to 980 nm and corresponding filters can be provided according to the measurement need of different luminescent materials. The monitoring wavelength of the currently used fiber optical spectrometer is from 300 nm to 1000 nm. For example, the PL spectral measurement of 54 samples in a {6 × 9} array is completed in only about 30 min by using a representative triple-channel fiber optical spectrometer. The designed multi-channel fiber optical spectrometer facility not only makes PL measurements faster and more intuitive but is also easy to popularize for wide users.
A compact 2.0 T superconducting magnet
Authors: Browning R.
Published: December 2020

A compact 2.0 T superconducting magnet has been developed for use in photoelectron microscopy. The magnet was required to be compact and magnetically well shielded with low stray fields. Because the magnet is for use with a microscope, the working volume can be small. A small volume implies that the stored magnetic energy is low, and with low stray fields, it makes the magnet safe while operating and during quench events. The magnet is a cryogen free design that uses a diamond loaded vacuum grease for current lead encapsulation and cooling. To make as small a coil as possible, a new coil winding method was developed that does not require solder joints between pancake windings. We show that a low temperature Sn/Bi/Ag eutectic solder can be used for connecting the input leads in this application.
Optimal dimensionality reduction of Markov chains using graph transformation
Authors: Kannan Deepti , Sharpe Daniel J. , Swinburne Thomas D. , Wales David J.
Published: December 2020

Markov chains can accurately model the state-to-state dynamics of a wide range of complex systems, but the underlying transition matrix is ill-conditioned when the dynamics feature a separation of timescales. Graph transformation (GT) provides a numerically stable method to compute exact mean first passage times (MFPTs) between states, which are the usual dynamical observables in continuous-time Markov chains (CTMCs). Here, we generalize the GT algorithm to discrete-time Markov chains (DTMCs), which are commonly estimated from simulation data, for example, in the Markov state model approach. We then consider the dimensionality reduction of CTMCs and DTMCs, which aids model interpretation and facilitates more expensive computations, including sampling of pathways. We perform a detailed numerical analysis of existing methods to compute the optimal reduced CTMC, given a partitioning of the network into metastable communities (macrostates) of nodes (microstates). We show that approaches based on linear algebra encounter numerical problems that arise from the requisite metastability. We propose an alternative approach using GT to compute the matrix of intermicrostate MFPTs in the original Markov chain, from which a matrix of weighted intermacrostate MFPTs can be obtained. We also propose an approximation to the weighted-MFPT matrix in the strongly metastable limit. Inversion of the weighted-MFPT matrix, which is better conditioned than the matrices that must be inverted in alternative dimensionality reduction schemes, then yields the optimal reduced Markov chain. The superior numerical stability of the GT approach therefore enables us to realize optimal Markovian coarse-graining of systems with rare event dynamics.
Bistability and hidden attractors in the paradigmatic Rössler’76 system
Authors: Malasoma Jean-Marc , Malasoma Niels
Published: December 2020

In this paper, the dynamics of the paradigmatic Rössler system is investigated in a yet unexplored region of its three-dimensional parameter space. We prove a necessary condition in this space for which the Rössler system can be chaotic. By using standard numerical tools, like bifurcation diagrams, Poincaré sections, and first-return maps, we highlight both asymptotically stable limit cycles and chaotic attractors. Lyapunov exponents are used to verify the chaotic behavior while random numerical procedures and various plane cross sections of the basins of attraction of the coexisting attractors prove that both limit cycles and chaotic attractors are hidden. We thus obtain previously unknown examples of bistability in the Rössler system, where a point attractor coexists with either a hidden limit cycle attractor or a hidden chaotic attractor.
Nanowire reconstruction under external magnetic fields
Authors: Fernández Eva M. , Santalla Silvia N. , Alvarellos José E. , Rodríguez-Laguna Javier
Published: December 2020

We consider the different structures that a magnetic nanowire adsorbed on a surface may adopt under the influence of external magnetic or electric fields. First, we propose a theoretical framework based on an Ising-like extension of the 1D Frenkel–Kontorova model, which is analyzed in detail using the transfer matrix formalism, determining a rich phase diagram displaying structural reconstructions at finite fields and an antiferromagnetic–paramagnetic phase transition of second order. Our conclusions are validated using ab initio calculations with density functional theory, paving the way for the search of actual materials where this complex phenomenon can be observed in the laboratory.
An improved passive shimming approach to design correction iron pieces for high field MRI
Authors: Wu Kaihong , Wu Yu , Shi Yi , Xu Aihua , Dai Chao , Hao Qiangwang , Han Houxiang , Liu Xiaochuan , Ma Yuanyuan , Zhang Yongliang , Wu Junrong , Hussain M. T.
Published: December 2020

This paper proposes a new passive shimming method to design correction iron pieces for compensating field impurities generated by the main magnets of high field magnetic resonance imaging (MRI) for human body imaging. First, the relationship formula of a magnetic dipole to any field point in space is established. Then, a sensitivity matrix in the form of spherical harmonic expansions can be set up based on the contribution of each shim piece to each field point. Next, an optimization procedure of linear programming is applied to determine the location and thickness of the ferromagnetic shim pieces. This is different from the previous methods that consider that all magnetic moments for each magnetized iron piece are located only at its central position, which may cause some intrinsic errors. This method takes the shim piece’s volume into account and gives more accurate results in a sensitivity matrix by means of integration in the azimuthal and axial directions while the radial (thickness) direction remains constant. Finally, a case study combining the analytical method and a 3D finite element analysis simulation demonstrates that the new approach provides better results in terms of homogeneity. The method presented can also be used to design passive shims for various practical MRI applications.
Spin–orbit torque as a method for field-free detection of in-plane magnetization switching
Authors: Khang Nguyen Huynh Duy , Hai Pham Nam
Published: December 2020

We proposed and demonstrated a simple method for field-free detection of in-plane magnetization switching by the spin–orbit torque (SOT) in bilayers of nonmagnetic/magnetic materials. In our method, SOT is used not only for magnetization switching but also for detection. SOT effective fields generated by an alternating reading current induce oscillation of the magnetization, which is detected via the anomalous Hall effect, planar Hall effect, anomalous Nernst effect, and spin Seebeck effect. Our method can detect arbitrary Mx and My components without an external magnetic field, which is useful for fast characterization of type-X, type-Y, and type-XY SOT magnetization switching. Our SOT detection scheme can be utilized not only for fast characterization of SOT switching in bilayers but also for electrical detection of in-plane magnetic domains in race-track memory.
Spin diffusion length in Au wires and films investigated by weak antilocalization measurements
Authors: Cai Yunhan , Wang Hua , Yue Di , Tian Dai , Jin Xiaofeng
Published: December 2020

Working with weak antilocalization measurements on Au wires and films grown by molecular beam epitaxy and dc magnetron sputtering with fine-tuned electron scatterings, we investigated the spin diffusion length in Au mesoscopic structures in quasi-1D and quasi-2D regimes. The result shows that the spin relaxations in both Au quasi-1D wires and quasi-2D films follow the Elliott–Yafet mechanism regardless of the deposition method. Furthermore, we observed a dimensionality behavior of spin diffusion between the quasi-1D and quasi-2D cases following the generalized Einstein's equation on Brownian motion.
Adsorption of methane on single metal atoms supported on graphene: Role of electron back-donation in binding and activation
Authors: Pantha Nurapati , Ulman Kanchan , Narasimhan Shobhana
Published: December 2020

We consider single metal atoms supported on graphene as possible candidate systems for on-board vehicular storage of methane or for methane activation. We use density functional theory to study the adsorption of one and two molecules of methane on such graphene-supported single atoms, where the metal atom M is a 3d-transition metal (Sc to Zn). Our results suggest that M = Sc, Ti, and V are the best candidates for gas storage applications, while Ni and Co seem particularly promising with respect to activation of the C–H bond in methane. We find a strong and linear correlation between the adsorption energy of methane and the degree of back-donation of electrons from occupied metal d-states to antibonding methane states. A similar correlation is found between the elongation of C–H bonds and electron back-donation. An important role is played by the graphene substrate in enhancing the binding of methane on metal atoms, compared to the negligible binding observed on isolated metal atoms.
Late-time turbulent mixing induced by multimode Richtmyer–Meshkov instability in cylindrical geometry
Authors: Ge Jin , Zhang Xin-ting , Li Hai-feng , Tian Bao-lin
Published: December 2020

Turbulent mixing induced by Richtmyer–Meshkov instability (RMI) in convergent geometry widely exists in natural phenomena and in engineering applications. In the present work, high-resolution numerical simulations of RMI at a complete cylindrical interface, with the imploding shock wave initially passing from the heavy fluid to the light fluid, are presented. Two different initial perturbations are applied. The mixing zone finally reaches a convergence ratio Cr ≈ 1.6 in both cases. Compared to classical RM instability, the more complex wave system, as well as the geometrical effect induced by the radial movement of mixing fluid, modifies the evolution of the mixing zone. The growth rate of the mixing width is analyzed in terms of the stretching or compression effect and species-penetration effect. In a cylindrical geometry, the stretching or compression effect is mainly induced by the wave system and the nonplanar geometric environment. The late-time turbulent mixing width induced by the penetration effect scales as (t−t0)θ, as with the evolution of planar RMI. For both cases, the mass-fraction profiles are collapsed at the late time if the radial coordinate is first shifted with the spike-front position and then scaled by the mixing width. By analyzing the distribution of the bubble (spike) contour, the dominant bubble (spike) diameter [D¯b(s)] is obtained. The ratios [βb(s)] between the dominant bubble (spike) diameter and the bubble (spike) amplitude [Wb(s)] are calculated, and a stable ratio of spike βs is observed during the late stage. Meanwhile, the ratio of the bubble βb is greater than 1 at late time.
New to the community setting: nurses’ experiences and the importance of orientation
Authors: Foley Linda , Avramidis Panagiota , Randall Sue
Published: December 2020

There has been little research about the experiences of nurses transitioning into community nursing (CN), despite the growing demand for nurses in this setting and impending shortfall in the nursing workforce in Australia. In this study, nurses from a busy metropolitan CN service were interviewed to explore how they experienced their first months in their new role. The interviews were analysed thematically, with three themes emerging: Adaptation, Focus of Care and Context. Participants detailed their experiences adjusting to new work practices and the community setting, and expanded on their enjoyment from increased autonomy, career goal recognition and rewarding patient relationships and outcomes. The findings of this study are aligned with previous literature about nurses entering the primary healthcare setting from acute care, and particularly highlight the need to individually tailor orientation, preceptorship and ongoing career development programs to each nurse.
Downregulation of autophagy by Met30-mediated Atg9 ubiquitination
Authors: Feng Yuchen , Ariosa Aileen R. , Yang Ying , Hu Zehan , Dengjel Jörn , Klionsky Daniel J.
Published: December 2020

Significance

Macroautophagy/autophagy removes surplus and/or dysfunctional cellular components for recycling in the lysosome/vacuole. During times of stress, autophagy is upregulated to ensure survival. A set of autophagy-related (Atg) proteins act in concert in a highly regulated manner to ensure proper levels of autophagy; aberrant induction of this process is correlated with numerous diseases. In this work, we show a nuanced mechanism by which autophagy is kept at a basal level via the ubiquitin−proteasome system-dependent reduction of Atg9, a transmembrane protein essential to autophagy.
Concerns for others increase the likelihood of vaccination against influenza and COVID-19 more in sparsely rather than densely populated areas
Authors: Jung Haesung , Albarracín Dolores
Published: December 2020

Significance

Vaccination yields the prosocial benefits of preventing the spread of infectious diseases and protecting communities from major disease outbreaks. This research examines how focusing on prosocial concerns motivates vaccination across environments with varying levels of social density. Contrary to the common intuition that prosocial concern should motivate vaccination more in denser areas with more social contacts and disease transmission risk, our results show that prosocial concern yields higher vaccination rates in sparser areas where people believe that their behavior will have more impact. This research identifies emphasizing prosocial aspects of vaccination as one means by which public health interventions can reduce the rural−urban disparity in vaccination.
Knockout of the HMG domain of the porcine SRY gene causes sex reversal in gene-edited pigs
Authors: Kurtz Stefanie , Lucas-Hahn Andrea , Schlegelberger Brigitte , Göhring Gudrun , Niemann Heiner , Mettenleiter Thomas C. , Petersen Björn
Published: December 2020

Significance

The present work characterizes the porcine sex-determining region on the Y chromosome (SRY) gene and demonstrates its pivotal role in sex determination. We provide evidence that genetically male pigs with a knockout of the SRY gene undergo sex reversal of the external and internal genitalia. This discovery of SRY as the main switch for sex determination in pigs may provide an alternative for surgical castration in pig production, preventing boar taint. As the pig shares many genetic, physiological, and anatomical similarities with humans, it also provides a suitable large animal model for human sex reversal syndromes, allowing for the development of new interventions for human sex disorders.
DNA polymerase ι compensates for Fanconi anemia pathway deficiency by countering DNA replication stress
Authors: Wang Rui , Lenoir Walter F. , Wang Chao , Su Dan , McLaughlin Megan , Hu Qianghua , Shen Xi , Tian Yanyan , Klages-Mundt Naeh , Lynn Erica , Wood Richard D. , Chen Junjie , Hart Traver , Li Lei
Published: December 2020

Significance

Pol ι is a highly conserved Y-family DNA polymerase. Disruptions of the Pol ι gene in cellular and mouse models, however, have so far failed to produce any detectable phenotype. Using unbiased whole genome fitness screens, we find that Pol ι is essential for the genome stability and survival of Fanconi anemia mutant cells. This finding reveals the physiological role for Pol ι as a compensatory factor of Fanconi anemia deficiency. It implies a novel genetic connection between lesion bypass and replication stress response. Furthermore, the identified synthetic lethality between Pol ι and the Fanconi anemia mechanism suggests an enzymatic and therapeutic target for eliminating tumor cells arising from the Fanconi anemia pathway defect.
Post-transcriptional tuning of FGF signaling mediates neural crest induction
Authors: Copeland Jacqueline , Simoes-Costa Marcos
Published: December 2020

Significance

The neural crest is a stem cell population that plays a crucial role in the establishment of the vertebrate body plan. Neural crest induction requires a delicate balance of multiple signaling systems, including FGFs. Moderate FGF activity is necessary for neural crest formation, but overactivation of the pathway drives progenitor cells into adopting a neuronal fate. Yet, it remains unclear how levels of FGF are fine tuned to promote neural crest identity. Here, we demonstrate how miRNA-mediated gene silencing modulates the intracellular response to FGF signaling to ensure proper neural crest cell specification. Understanding the function of these miRNAs may broaden our understanding of the neural crest genetic program and shed light on the etiology of neural crest-linked congenital disabilities.
Prioritized experience replays on a hippocampal predictive map for learning
Authors: Igata Hideyoshi , Ikegaya Yuji , Sasaki Takuya
Published: December 2020

Significance

The hippocampus is crucial for spatial learning but their neuronal mechanisms remain unknown. Here, we found that hippocampal cell ensembles preferentially replayed salient reward-related locations as rats learned a new behavioral trajectory for reward. The contents of these hippocampal replays progressively varied with learning. Especially during learning, hippocampal neurons even replayed an optimized path that had never been exploited by the animals. The learning-related hippocampal activity was necessary for the stabilization of spatial behavior. These results suggest prioritized replays of significant experiences on a predictive map by hippocampal neurons.
Microrheology reveals microscale viscosity gradients in planktonic systems
Authors: Guadayol Òscar , Mendonca Tania , Segura-Noguera Mariona , Wright Amanda J. , Tassieri Manlio , Humphries Stuart
Published: December 2020

Significance

At the microscopic scales at which the life of marine microbes unfolds, the physics is dominated by viscosity. Increasing viscosity slows down both the passive transport of solutes and particles and the swimming of motile microorganisms, and thus directly or indirectly affects all aspects of microbial life. Viscosity depends not only on the physical properties of water, but it also varies as a consequence of biological activity, allowing microorganisms some control over their physical landscape. Our use of microrheology allows us to explore how viscosity is structured around phytoplankton cells and marine aggregates and unveils a level of spatial heterogeneity that has implications for the functioning of the microbial food web and hence of marine biogeochemical cycles.
Nitric oxide resets kisspeptin-excited GnRH neurons via PIP2 replenishment
Authors: Constantin Stephanie , Reynolds Daniel , Oh Andrew , Pizano Katherine , Wray Susan
Published: December 2020

Significance

Hypothalamic neural networks control hormone secretion to maintain body function. For gonadotropin-releasing hormone (GnRH) neurons, critical to fertility, release must be pulsatile. While it is clear that kisspeptin neurons trigger GnRH activity and pulses, how GnRH neurons return to baseline activity before the next stimulation is unknown. Here, we show 1) that the long-lasting response of GnRH neurons to kisspeptin depends on the degradation of phosphatidylinositol 4,5-bisphosphate (PIP2) and its slow resynthesis keeping canonical transient receptor potential channels opened and 2) a mechanism whereby nitric oxide facilitates PIP2resynthesis and GnRH neuron recovery from kisspeptin activation. Defining the overlap in kisspeptin and nitric oxide signaling pathways may provide an avenue for fertility treatment.