bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitochondria-related core genes and TF-miRNA-hub mrDEGs network in breast cancer
Authors: Yan Li-rong , Wang Ang , Lv Zhi , Yuan Yuan , Xu Qian
Published: January 2021

Background: Mitochondria-nuclear cross-talk and mitochondrial retrograde regulation are involved in the genesis and development of breast cancer (BC). Therefore, mitochondria can be regarded as a promising target for BC therapeutic strategies. The present study aimed to construct regulatory network and seek the potential biomarkers of BC diagnosis and prognosis as well as the molecular therapeutic targets from the perspective of mitochondrial dysfunction. Methods: The microarray data of mitochondria-related encoding genes in BC cell lines were downloaded from GEO including GSE128610 and GSE72319. GSE128610 was treated as test set and validation sets consisted of GSE72319 and TCGA tissue samples, intending to identify mitochondria-related differentially expressed genes (mrDEGs). We performed enrichment analysis, PPI network, hub mrDEGs and overall survival analysis and constructed transcription factor (TF)-miRNA-hub mrDEGs network. Results: A total of 23 up-regulated and 71 down-regulated mrDEGs were identified and validated in BC cell lines and tissues. Enrichment analyses indicated that mrDEGs were associated with several cancer-related biological processes. Moreover, 9 hub mrDEGs were identified and validated in BC cell lines and tissues. Finally, 5 hub coregulated mrDEGs, 21 miRNAs and 117 TFs were used to construct TF-miRNA-hub mrDEGs network. MYC associated zinc finger protein (MAZ), heparin binding growth factor (HDGF) and Sp2 transcription factor (SP2) regulated 3 hub mrDEGs. Hsa-mir-21-5p, hsa-mir-1-3p, hsa-mir-218-5p, hsa-mir-26a-5p and hsa-mir-335-5p regulated 2 hub mrDEGs. Overall survival analysis suggested that the up-regulation of fibronectin 1 (FN1), as well as the down-regulation of discoidin domain receptor tyrosine kinase 2 (DDR2) correlated with unfavorable prognosis in BC. Conclusion: TF-miRNA-hub mrDEGs had instruction significance for the exploration of BC etiology. The hub mrDEGs such as FN1 and DDR2 were likely to regulate mitochondrial function and be novel biomarkers for BC diagnosis and prognosis as well as the therapeutic targets.
Studying chromosome biology with single-molecule resolution in Xenopus laevis egg extracts
Authors: Cameron George , Yardimci Hasan
Published: January 2021

Cell-free extracts from Xenopus laevis eggs are a model system for studying chromosome biology. Xenopus egg extracts can be synchronised in different cell cycle stages, making them useful for studying DNA replication, DNA repair and chromosome organisation. Combining single-molecule approaches with egg extracts is an exciting development being used to reveal molecular mechanisms that are difficult to study using conventional approaches. Fluorescence-based single-molecule imaging of surface-tethered DNAs has been used to visualise labelled protein movements on stretched DNA, the dynamics of DNA–protein complexes and extract-dependent structural rearrangement of stained DNA. Force-based single-molecule techniques are an alternative approach to measure mechanics of DNA and proteins. In this essay, the details of these single-molecule techniques, and the insights into chromosome biology they provide, will be discussed.
Evolution of superclusters and supercluster cocoons in various cosmologies
Authors: Einasto J. , Hütsi G. , Suhhonenko I. , Liivamägi L. J. , Einasto M.
Published: January 2021

Aims. We investigate the evolution of superclusters and supercluster cocoons (basins of attraction), and the effect of cosmological parameters on the evolution.

Methods. We performed numerical simulations of the evolution of the cosmic web for different cosmological models: the Λ cold dark matter (LCDM) model with a conventional value of the dark energy (DE) density, the open model OCDM with no DE, the standard SCDM model with no DE, and the hyper-DE HCDM model with an enhanced DE density value. We find ensembles of superclusters of these models for five evolutionary stages, corresponding to the present epoch z = 0, and to redshifts z = 1, 3, 10, and 30. We used the diameters of the largest superclusters and the number of superclusters as percolation functions to describe the properties of the ensemble of superclusters in the cosmic web. We analysed the size and mass distribution of superclusters in models and in real samples based on the Sloan Digital Sky Survey.

Results. In all models, the numbers and volumes of supercluster cocoons are independent of the cosmological epochs. The supercluster masses increase with time and the geometrical sizes in comoving coordinates decrease with time for all models. The LCDM, OCDM, and HCDM models have almost similar percolation parameters. This suggests that the essential parameter, which defines the evolution of superclusters, is the matter density. The DE density affects the growth of the amplitude of density perturbations and the growth of masses of superclusters, but significantly weaker. The HCDM model has the highest speed of the growth of the density fluctuation amplitude and the largest growth of supercluster masses during the evolution. The geometrical diameters and the numbers of HCDM superclusters at high threshold densities are larger than for the LCDM and OCDM superclusters. The SCDM model has about twice as many superclusters as other models, and the SCDM superclusters have smaller diameters and lower masses.

Conclusions. We find that supercluster embryos form at very early cosmological epochs and that the evolution of superclusters occurs mainly inside their cocoons. The evolution of superclusters and their cocoons as derived from density fields agress well with the evolution found from velocity fields.
New exact traveling wave solutions to the (2+1)-dimensional Chiral nonlinear Schrödinger equation
Authors: Rezazadeh Hadi , Younis Muhammad , Shafqat-Ur-Rehman  , Eslami Mostafa , Bilal Muhammad , Younas Usman
Published: January 2021

In this research work, we successfully construct various kinds of exact traveling wave solutions such as trigonometric like, singular and periodic wave solutions as well as hyperbolic solutions to the (2+1)-dimensional Chiral nonlinear Schröginger equation (CNLSE) which is used as a governing equation to discuss the wave in the quantum field theory. The mechanisms which are used to obtain these solutions are extended rational sine-cosine/sinh-cosh and the constraint conditions for the existence of valid solutions are also given. The attained results exhibit that the proposed techniques are a significant addition for exploring several types of nonlinear partial differential equations in applied sciences. Moreover, 3D, 2D-polar and contour profiles are depicted for showing the physical behavior of the reported solutions by setting suitable values of unknown parameters.
The Relationship between Capital Structure and Financial Performance of the Company
Authors: Tretiakova V.V. , Shalneva M.S. , Lvov A.S.
Published: January 2021

The article examines and analyzes the relationship of key performance indicators (ROA, ROIC, change in market capitalization and price-to-book ratio) and the capital structure of the company based on the pharmaceutical industry in the UK for the 2009-2019 period. The study seeks to provide a practical evidence on the impact of external financing on company’s financial performance and test applicability of the pecking order theory for the chosen companies. The research conducted uses panel data regression and Wald test to determine and analyze the effect of capital structure on the financial indicators of the company performance. The study used a sample of 185 UK companies from the pharmaceutical industry. The result of the research showed that equity has negative effect on price-to-book ratio and ROA and positive effect on change in market capitalization, while long-term debt has a positive relationship with price- to-book ratio and change in market capitalization. In addition, short-term debt has a negative effect on change in market capitalization, ROA and ROIC. The study also provides only partly coincidence of the results with the pecking order theory.
Resource Potential as a Key Factor of Ukrainian Mining Enterprises Competitive Position
Authors: Pochtovyuk Andriy , Latyshev Kostyantyn , Zaika Kateryna
Published: January 2021

The paper is devoted to formulation of theoretical, methodological and practical recommendations for ensuring enterprise sustainable competitiveness based on an integrated assessment of key resource determinants. The issue of ensuring enterprise competitiveness require increased attention in modern conditions of Ukrainian economy development. It was determined that implementation in production practice of these tasks are possible due to the efficient enterprise resource potential management, which will ensure maximum using of production capacity, cost reduction, improving product quality and competitive position stability. An object of the study is decision-making processes that appear using the enterprise competitiveness resource potential. Subject of the study is expansion of high-quality products’ production in conditions of world demand. The authors were solved the following set of tasks: was clarified the term’s essence «competitiveness» according scientific approach; was determined the enterprise position based on competitiveness integral index calculation; was identified enterprise competitiveness main components in accordance with the resource concept; an assessment of the enterprise technical and economic condition was carried out by calculating the wear and sustainable coefficients, also products qualitative parameters were established based on economic and mathematical modelling methods. The reasons for the decrease in the rate of metallurgical enterprise development were determined: outdated technologies, the need to comply with international quality standards, increased competition in the market, wear of fixed assets. In the final part, to solve these problems, a set of measures has been developed to improve the state of the enterprise by expanding the production of high-quality products through an investment strategy.
Impact of Credit Market Development on Project Financing
Authors: Poradova Monika , Janoskova Katarina
Published: January 2021

The purpose of our report is to assess the prospects and sentiment for bank financing in the real estate sector in Europe, based on the views of bank representatives from 15 European countries. The presented paper is devoted to the issue of project financing. The aim is to provide an analytical overview of the issue of project financing as a specific credit financing instrument with the current access to finance for banks in Europe. The paper consists of four parts. The first part deals with the issue of project financing, the different dates of project financing and classifies project financing in terms of penalties. The second part of the paper aims to clarify the alternative method of project financing and analysis of banks in Europe. The third part of the article addressed the concrete results of the analysis and carried out discussion. Describes the volumes of credit transactions. The fourth part deals with the conclusion of the issue of project financing. A descriptive method, analysis, mathematical-statistical methods, graphic methods, comparison and synthesis was used in the processing of the paper submitted. The result of this article is that, in the future, the general financing conditions are expected to remain relatively favourable across Europe. This may be due in particular to competitive pressure contributing to milder credit conditions. However, trade tensions, declining investments, as well as policy concerns on a global scale, may curb such optimism for the next few years.
Reconstruction of Orbital Exenteration Defects with Cheek Rotation Flaps: Indications, Technique, Complications, Rehabilitation, and Survival
Authors: Baum Sven Holger , Mohr Christopher
Published: January 2021

The objective of this study was to examine the role of cheek rotation flaps in the reconstruction of orbital defects after exenteration. From January 2000 to August 2018, patients undergoing orbital exenteration and reconstruction with cheek rotation flaps were enrolled in this retrospective study. All patients were evaluated for wound complications, orbital rehabilitation, tumor relapse, and survival. Thirty patients completed the study. Fourteen complications allocated to 11 patients were assessed. The most common complications were seroma (13%), temporary facial nerve weakness (13%), and partial necrosis of the flap (10%). A major complication occurred in a total of two patients (7%), so that surgical correction was necessary. Eleven patients had a relapse; 15 patients died as part of the follow-up. Fifteen patients were treated with facial prostheses. The overall survival rate was 61% after 1 year and 42% after 5 years. Follow-up periods ranged from 6 to 95 months. Cheek rotation flap reconstruction after exenteration is a reliable method with a low rate of major complications. It is indicated when an approach to the parotid gland or the neck region is necessary because of suspected lymph node metastasis and in elderly patients because of their skin's laxity. It can be performed as primary or secondary reconstruction. Good esthetic results can be achieved, especially after endosseous implantation.
Platelet-Rich Fibrin Enhances Surgical Wound Healing in Total Laryngectomy
Authors: Reksodiputro Mirta H. , Hutauruk Syahrial M. , Widodo Dini W. , Fardizza Fauziah , Mutia Dita
Published: January 2021

Autologous growth factor (AGF) is a cytokine that has gained medical research interest because it helps improve and accelerate the wound healing process. Platelet-rich fibrin (PRF) is the latest generation of platelet concentrate that can be obtained through a simple procedure known as AGF referencing. One of the most common complications of total laryngectomy (TL) is pharyngocutaneous fistula. To prevent this complication, health care providers must closely monitor the postoperative wound healing process.This study aimed to investigate the effectiveness of PRF application in enhancing wound healing after TL. A randomized controlled trial was conducted in the Department of Otorhinolaryngology - Head and Neck Surgery, Faculty of Medicine, Dr. Cipto Mangunkusumo Hospital Universitas Indonesia, Jakarta, Indonesia, from June 2019 to December 2019. We included 20 patients who underwent TL for laryngeal squamous cell carcinoma. They were divided into two groups (10 patients who received applied autologous PRF around the esophageal stoma during TL and another 10 patients as the control). These patients were observed for 2 weeks postoperatively. In the bivariate analysis performed using the chi-square test, the pain threshold and edema of postoperative wounds in the PRF-treated group demonstrated significant differences compared with those in the control group. PRF application in TL enhanced the postoperative wound healing process, especially with regard to edema and pain.
Hepatic Involvement in Aicardi-Goutières Syndrome
Authors: Gavazzi Francesco , Cross Zachary M. , Woidill Sarah , McMann Joseph M. , Rand Elizabeth B. , Takanohashi Asako , Ulrick Nicole , Shults Justine , Vanderver Adeline L. , Adang Laura
Published: January 2021

Aicardi-Goutières syndrome (AGS) is a monogenic type-I interferonopathy that results in neurologic injury. The systemic impact of sustained interferon activation is less well characterized. Liver inflammation is known to be associated with the neonatal form of AGS, but the incidence of AGS-related hepatitis across lifespan is unknown.

We compared natural history data including liver enzyme levels with markers of inflammation, (liver-specific autoantibodies and interferon signaling gene expression[ISG] scores). Liver enzymes were classified as normal or elevated by the fold increase over the upper limit of normal (ULN). The highest increases were designated as hepatitis, defined as aspartate-aminotransferase or alanine-aminotransferase threefold ULN, or gamma-glutamyl transferase 2.5-fold ULN. A larger cohort was used to further characterize the longitudinal incidence of liver abnormalities and the association with age and genotype.

Across the AGS cohort (n = 102), elevated liver enzymes were identified in 76 individuals (74.5%) with abnormalities at a level consistent with hepatitis in 29 individuals (28.4%). SAMHD1 mutations were less likely to be associated with hepatitis (log-rank test; p = 0.011). Hepatitis was associated with early-onset disease and microcephaly (log-rank test; microcephaly p = 0.0401, age onset p = 0.0355). While most subjects (n = 20/33) were found to have liver-specific autoantibodies, there was no association between the presence of autoantibodies or ISG scores with hepatitis-level enzyme elevations.

In conclusion, all genotypes of AGS are associated with transient elevations of liver enzymes and the presence of liver-associated autoantibodies. This adds to our growing understanding of the systemic pathology AGS.
Accelerating flyer plates via underwater wire explosions to create shock compression
Authors: Frank Jodi Ackerman
Published: January 2021

The technique for studying extreme astrophysics conditions increases the energy transfer efficiency by an order of magnitude compared to conventional methods.
Scaling of laser-driven electron and proton acceleration as a function of laser pulse duration, energy, and intensity in the multi-picosecond regime
Authors: Simpson R. A. , Scott G. G. , Mariscal D. , Rusby D. , King P. M. , Grace E. , Aghedo A. , Pagano I. , Sinclair M. , Armstrong C. , Manuel M. J.-E. , Haid A. , Flippo K. , Winslow L. , Gatu-Johnson M. , Frenje J. A. , Neely D. , Kerr S. , Williams G. J. , Andrews S. , Cauble R. , Charron K. , Costa R. , Fischer B. , Maricle S. , Stuart B. , Albert F. , Lemos N. , Mackinnon A. , MacPhee A. , Pak A. , Ma T.
Published: January 2021

A scaling study of short-pulse laser-driven proton and electron acceleration was conducted as a function of pulse duration, laser energy, and laser intensity in the multi-picosecond (ps) regime (∼0.8 ps–20 ps). Maximum proton energies significantly greater than established scaling laws were observed, consistent with observations at other multi-ps laser facilities. In addition, maximum proton energies and electron temperatures in this regime were found to be strongly dependent on the laser pulse duration and preplasma conditions. A modified proton scaling model is presented that is able to better represent the accelerated proton characteristics in this multi-ps regime.
Design and development of a miniaturized multiaxial test setup for in situ x-ray diffraction experiments
Authors: Bhaskar Lalith Kumar , Kumar Gobind , Srinivasan Nedunchezhian , Kumar Ravi
Published: January 2021

In this work, a novel stand-alone multi-axial loading test setup was developed to test miniature samples under uniaxial tension, uniaxial compression, in-plane biaxial tension, and biaxial compression stress states. Good agreement in stress–strain responses was observed between the uniaxial experiments carried out using the miniature sample geometry in the custom-built setup and the uniaxial standard geometry in a universal testing machine. With regard to biaxial experiments, the full-field strain captured using digital image correlation for the biaxial specimens revealed strain homogeneity in the central gage section of the sample. Furthermore, the in situ capability of the setup was demonstrated by integrating it with a commercial laboratory x-ray diffractometer, and good agreement was found between the calculated stress values from the load sensor and the stress obtained using x-ray diffraction.
Performance enhancement of the piezoelectric ceramics by alternating current polarizing
Authors: Ma Jinpeng , Zhu Ke , Huo Da , Qi Xudong , Sun Enwei , Zhang Rui
Published: January 2021

The piezoelectric properties of the PZT-5H ceramics under various polarization conditions are compared and analyzed. It is worth noting that compared to direct current polarization, the piezoelectric coefficient (d33), free dielectric constant (ε33T/ε0), and electromechanical coupling coefficient (kt) of the PZT-5H ceramics under alternating current polarization (ACP) have increased by 10.7%, 15.9%, and 15.4%, respectively. According to the analysis of the domain distribution patterns in the [001] surface of the PZT-5H ceramics under the two polarization conditions measured using a piezoresponse force microscope, the ACP makes the piezoelectric material have a high density of the domain wall, which greatly enhances its piezoelectric performance. This work provides an effective means to improve the piezoelectric properties of PZT-5H ceramics and will be of great significance to piezoelectric applications using this type of piezoelectric ceramic.
In situAC-hysteresis measurements of SPD-processed Cu20(Fe15Co85)80
Authors: Stückler Martin , Wurster Stefan , Pippan Reinhard , Bachmaier Andrea
Published: January 2021

The changes of magnetic properties upon heat treatment of a metastable supersaturated solid solution processed by severe plastic deformation are investigated by in situ AC-hysteresis measurements. Data are analyzed in the framework of dynamic loss theory, with correlative investigations of the microstructural properties. The evolution of hysteresis upon annealing points out that the single-phase supersaturated solid solution remains stable up to 400° C, then hindering of domain wall motion sets in at this temperature. At 600° C, a multi phase microstructure is present, causing a significant increase in coercivity.
Fast and in situ remanent flux detection method for a protection current transformer based on the fluxgate theory
Authors: Zheng T. , Wang Y.
Published: January 2021

This paper proposes a fast and in situ remanent flux detection method for a protection current transformer (CT) based on the fluxgate theory. A high frequency voltage source is connected to the secondary side of the CT, and saturates the core slightly in the positive or negative direction. The polarity of the remanent flux is decided by the sign of integral of the voltage. The remanent flux is calculated with the linear relationship between the remanent flux and the second harmonic of the high frequency component of the voltage. The linear relationship can be obtained in advance considering the fluxgate theory. To verify the performance of the proposed remanent flux detection method, different levels of remanent flux, with and without primary current, are considered with Electromagnetic Transient Program - Restructured Version simulations. The results indicate that the proposed method can quickly and effectively detect the remanent flux of a protection CT in situ, which means that the CT is not required to be removed from the substation.
An in vivo screen of noncoding loci reveals that
Daedalus
is a gatekeeper of an Ikaros-dependent checkpoint during haematopoiesis
Authors: Harman Christian C. D. , Bailis Will , Zhao Jun , Hill Louisa , Qu Rihao , Jackson Ruaidhrí P. , Shyer Justin A. , Steach Holly R. , Kluger Yuval , Goff Loyal A. , Rinn John L. , Williams Adam , Henao-Mejia Jorge , Flavell Richard A.
Published: January 2021

Significance

The development of lymphocytes is critical for host immunity and relies on a series of developmental checkpoints regulated by key transcription factors such as Ikaros. We hypothesized that nonprotein-coding loci might represent an additional layer of control in lymphocyte development. We identified a noncoding region (Daedalus) whose absence leads to a profound loss of Ikaros protein and a severe reduction in early lymphocyte progenitors. In contrast to Ikaros deletion, removal of Daedalus also led to an increase in red-blood-cell colony formation, suggesting that Daedalus functions as a lineage-specific stabilizer of Ikaros activity, thus acting as a “gatekeeper” of a newly identified lymphoid-erythroid checkpoint. This finding presents a paradigm potentially applicable to the control of all developmental programs.
Orthogonal immunoassays for IgG antibodies to SARS-CoV-2 antigens reveal that immune response lasts beyond 4 mo post illness onset
Authors: Sasisekharan Varun , Pentakota Niharika , Jayaraman Akila , Tharakaraman Kannan , Wogan Gerald N. , Narayanasami Uma
Published: January 2021

Significance

The COVID-19 pandemic continues to ravage our society, posing serious economic, social, health, and educational concerns in communities. Understanding the human humoral immune response to COVID-19 infection will greatly inform public health measures to help contain the spread of the disease in the foreseeable future. Here, we present an orthogonal approach to SARS-CoV-2 antibody testing using distinct viral antigens. Using this testing platform, we conducted a community-based analysis of patients with varying experiences with COVID-19. The data from our study show correlations between IgG titer and clinical features (i.e. length and severity of COVID-19 illness) and that IgG titers against SARS-CoV-2 may persist for more than 4 mo post onset of COVID-19 illness.
Association of methotrexate use and lymphoproliferative disorder in patients with rheumatoid arthritis: Results from a Japanese multi-institutional retrospective study
Authors: Honda Suguru , Sakai Ryoko , Inoue Eisuke , Majima Masako , Konda Naoko , Takada Hideto , Kihara Mari , Yajima Nobuyuki , Nanki Toshihiro , Yamamoto Kazuhiko , Takeuchi Tsutomu , Harigai Masayoshi
Published: January 2021

Objectives

To investigate the risk factors and clinical characteristics of lymphoproliferative disorder (LPD) in Japanese patients with rheumatoid arthritis (RA).

Methods

We enrolled patients with RA aged ≥20 years who visited the participating hospitals between April 2011 and July 2011. We investigated the risk factors for LPD using a Cox proportional hazard model and described pathological features and vital prognosis of LPD in patients with RA.

Results

We enrolled 9815 patients with the following characteristics at baseline: female 79.4%, median age 63 years; median disease duration 7 years; median DAS28-CRP (3) 3.1; prevalence of MTX use 60.0%. Sixty-eight patients (0.69%) developed LPD in 3-year observation period. Multivariable analysis showed that age by decade (hazard ratio [95% confidence interval], 1.47 [1.18–1.85]) and MTX use at baseline (2.35 [1.25–4.42] for ≤8 mg/week, 4.39 [2.07–9.32] for >8 mg/week versus non-use) were significant risk factors of LPD. Of 55 patients with pathological diagnosis, diffuse large B cell lymphoma was the most frequent (54%). The 5-year mortality of LPD was 24%. The major cause of death was lymphoma (81%).

Conclusion

This nationwide study revealed risk factors, clinical characteristics, and prognosis of LPD in the largest number of Japanese patients with RA.
Agreement of maximal lactate steady state with critical power and physiological thresholds in rowing
Authors: Possamai Leonardo Trevisol , Borszcz Fernando Klitzke , de Aguiar Rafael Alves , de Lucas Ricardo Dantas , Turnes Tiago
Published: January 2021

The aim of this study was threefold: (a) to compare the maximal lactate steady state (MLSS) with critical power (CP); (b) to describe the relationship of MLSS with rowing performances; and (c) to verify the agreement of MLSS with several exercise intensity thresholds in rowers. Fourteen male rowers (mean [SD]: age = 26 [13] years; height = 1.82 [0.05] m; body mass = 81.0 [7.6] kg) performed on a rowing ergometer: (I) discontinuous incremental test with 3 min stages and 30‐s recovery intervals (INC3min); (II) continuous incremental test with 60‐s stages (INC1min); (III) two to four constant workload tests to determine MLSS; and (IV) performance tests of 500, 1000, 2000 and 6000 m to determine CP. Twenty‐seven exercise intensity thresholds based on blood lactate, heart rate and ventilatory responses were determined by incremental tests, and then compared with MLSS. CP (257 [38] W) was higher than MLSS (187 [25] W; p < 0.001), with a very large mean difference (37%), large typical error of estimate (14%) and moderate correlation (r = 0.48). Despite the correlations between MLSS and most intensity thresholds (r > 0.70), all presented low correspondence (TEE > 5%), with a lower bias found between MLSS and the first intensity thresholds (−12.5% to 4.1%). MLSS was correlated with mean power during 500 m (r = 0.65), 1000 m (r = 0.86) and 2000 m (r = 0.78). In conclusion, MLSS intensity is substantially lower than CP and presented low agreement with 27 incremental‐derived thresholds, questioning their use to estimate MLSS during rowing ergometer exercise.

Highlights

MLSS was substantially lower than CP in rowing exercise with a mean difference of 37%, much larger than the difference commonly found in running and cycling exercise (i.e., ?10%).

A clear disagreement was reported between MLSS and 27 physiological thresholds determined in different incremental tests.

There is a positive association of MLSS with 500, 1000 and 2000 m rowing ergometer performance tests.
Granular detail of β cell structures for insulin secretion
Authors: Bogan Jonathan S.
Published: January 2021

Pancreatic β cells secrete insulin in response to increased glucose concentrations. Müller et al. (2021. J. Cell Biol. https://doi.org/10.1083/jcb.202010039) use 3D FIB-SEM to study the architecture of these cells and to elucidate how glucose stimulation remodels microtubules to control insulin secretory granule exocytosis.
Neuroinvasion of SARS-CoV-2 in human and mouse brain
Authors: Song Eric , Zhang Ce , Israelow Benjamin , Lu-Culligan Alice , Prado Alba Vieites , Skriabine Sophie , Lu Peiwen , Weizman Orr-El , Liu Feimei , Dai Yile , Szigeti-Buck Klara , Yasumoto Yuki , Wang Guilin , Castaldi Christopher , Heltke Jaime , Ng Evelyn , Wheeler John , Alfajaro Mia Madel , Levavasseur Etienne , Fontes Benjamin , Ravindra Neal G. , Van Dijk David , Mane Shrikant , Gunel Murat , Ring Aaron , Kazmi Syed A. Jaffar , Zhang Kai , Wilen Craig B. , Horvath Tamas L. , Plu Isabelle , Haik Stephane , Thomas Jean-Leon , Louvi Angeliki , Farhadian Shelli F. , Huttner Anita , Seilhean Danielle , Renier Nicolas , Bilguvar Kaya , Iwasaki Akiko
Published: January 2021

Although COVID-19 is considered to be primarily a respiratory disease, SARS-CoV-2 affects multiple organ systems including the central nervous system (CNS). Yet, there is no consensus on the consequences of CNS infections. Here, we used three independent approaches to probe the capacity of SARS-CoV-2 to infect the brain. First, using human brain organoids, we observed clear evidence of infection with accompanying metabolic changes in infected and neighboring neurons. However, no evidence for type I interferon responses was detected. We demonstrate that neuronal infection can be prevented by blocking ACE2 with antibodies or by administering cerebrospinal fluid from a COVID-19 patient. Second, using mice overexpressing human ACE2, we demonstrate SARS-CoV-2 neuroinvasion in vivo. Finally, in autopsies from patients who died of COVID-19, we detect SARS-CoV-2 in cortical neurons and note pathological features associated with infection with minimal immune cell infiltrates. These results provide evidence for the neuroinvasive capacity of SARS-CoV-2 and an unexpected consequence of direct infection of neurons by SARS-CoV-2.
Stem cell origins of JMML
Authors: Sundaravel Sriram , Steidl Ulrich
Published: January 2021

In this issue of JEM, Louka et al. (https://doi.org/10.1084/jem.20180853) report that leukemia stem cells lie within the phenotypic hematopoietic stem cell and progenitor cell compartments in juvenile myelomonocytic leukemia (JMML). Furthermore, they identify several candidate biomarker/therapeutic targets, such as CD96 and SLC2A1, that are of translational significance in JMML.
On the dynamics of a motorcycle weave
Authors: Zizler Peter , Sobhanzadeh Mandana , Ittyipe Ron
Published: January 2021

While riding a motorcycle the rider can find the handlebars along with the motorcycle frame to begin to oscillate at a high frequency. This motorcycle weave can be very dangerous as its frequency can be high at high speeds of the motorcycle. We collect evidence as how to avoid this motorcycle weave by numerically analyzing the eigenvalues of a certain matrix polynomial arising from the linearized model for the motorcycle motion. Among other suggestions, our simulations confirm that the rider leaning forward indeed mitigates such a high-speed motorcycle weave. Our model provides a prediction as to what attributes of the motorcycle increase or decrease the chances of the weave occurring.
Successive Lorentz transformations for energy and momentum. Application: relativistic elastic scattering of two particles having non-collinear velocities and its dependence on Thomas rotation
Authors: Chamseddine Riad
Published: January 2021

Successive Lorentz transformations (SLT) for energy and momentum are derived, and the involved Thomas rotation angle (TRA) is highlighted. In particular, if the axes of the coordinate systems related by SLT are suitably chosen, the SLT for energy and momentum do not depend on the TRA explicitly and take a form analogous to that of the Lorentz transformation for energy and momentum. Then the study of dynamical problems involving SLT becomes as easy as that of dynamical problems involving a Lorentz transformation. Those results are applied to the study of a relativistic elastic scattering of two particles having non-collinear velocities as a dynamical problem involving SLT. The expressions for the energies and momentums of the scattered particles in the laboratory system are obtained in terms of the TRA. If the considered particles are protons with given non-collinear velocities, the TRA, the energies and directions of the scattered protons are determined. Original diagrams for momentum are obtained.
Semi-classical methods, angular momentum, and non-analytic problems
Authors: Mann Nelia , Matli Jessica , Pham Tuan
Published: January 2021

We explore the semi-classical Sommerfeld method of quantization as applied to states with nonzero angular momentum, and show that it leads to qualitatively and quantitatively useful information about systems with spherically symmetric potentials. We begin by reviewing the traditional application of this model to hydrogen, and discuss the way Einstein–Brillouin–Keller (EBK) quantization resolves a mismatch between Sommerfeld states and true quantum mechanical states. We then analyze systems with logarithmic and Yukawa potentials, and compare the results of Sommerfeld and EBK quantization to those from solving Schrödinger’s equation. We show that the semi-classical quantization techniques provide insight into the spread of energy levels associated with a given principle quantum number, as well as giving quantitatively accurate approximations for the energies. We also argue that analyzing systems in this manner involves an interesting application of numerical methods, as well as providing insight into the connections between classical and quantum mechanical physics.
How can the nucleus be lighter than its constituents?
Authors: Bomark N-E
Published: January 2021

The fact that the nucleus is lighter than its constituents, seems rather strange. How can the whole have a smaller mass than its components? To get some intuition about how this is possible, one can look at a simpler more familiar system exhibiting the same phenomena; the hydrogen atom. It turns out that the same is true here; the hydrogen atom is a little bit lighter than the sum of its constituents. This difference corresponds to the ionisation energy of hydrogen. This observation allows a simple explanation for how this is possible; the destructive interference between the electric fields of the proton and electron causes a reduction in the energy of the electric field and hence a reduction in the contribution to the mass of the system from the electric field energy. The same explanation can be extended to the nucleus, thus giving some intuition about how this mass reduction happens. In the process, the idea of classical particles being ball-like objects with localised properties, is challenged.
Recovering a potential in damped wave equation from Dirichlet-to-Neumann operator
Authors: Romanov Vladimir , Hasanov Alemdar
Published: January 2021

The inverse problem of recovering the potential q(x) in the damped wave equation

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, (x, t) ∈ Ω
T
≔ (0, ℓ) × (0, T) subject to the boundary conditions u(0, t) = ν(t), u(ℓ, t) = 0, from the Neumann boundary measured output f(t) ≔ r(0)u

x
(0, t), t ∈ (0, T] is studied. The approach proposed in this paper allows us to derive behavior of the direct problem solution in the subdomains defined by characteristics of the wave equation and along the characteristic lines, as well. Based on these results, a local existence theorem and the stability estimate are proved. The compactness and Lipschitz continuity of the Dirichlet-to-Neumann operator are derived. Fréchet differentiability of the Tikhonov functional is proved and an explicit gradient formula is derived by means of an appropriate adjoint problem. It is proved that this gradient is Lipschitz continuous.
Unique continuation from a generalized impedance edge-corner for Maxwell’s system and applications to inverse problems
Authors: Diao Huaian , Liu Hongyu , Zhang Long , Zou Jun
Published: January 2021

We consider the time-harmonic Maxwell system in a domain with a generalized impedance edge-corner, namely the presence of two generalized impedance planes that intersect at an edge. The impedance parameter can be 0, ∞ or a finite non-identically vanishing function. We establish an accurate relationship between the vanishing order of the solutions to the Maxwell system and the dihedral angle of the edge-corner. In particular, if the angle is irrational, the vanishing order is infinity, i.e. strong unique continuation holds from the edge-corner. The establishment of those new quantitative results involve a highly intricate and subtle algebraic argument. The unique continuation study is strongly motivated by our study of a longstanding inverse electromagnetic scattering problem. As a significant application, we derive several novel unique identifiability results in determining a polyhedral obstacle as well as its surface impedance by a single far-field measurement. We also discuss another potential and interesting application of our result in the inverse scattering theory related to the information encoding.
Monte Carlo event generation of neutrino–electron scattering
Authors: Zhuridov Dmitry , Sobczyk Jan T , Juszczak Cezary , Niewczas Kajetan
Published: January 2021

We describe an extension of the NuWro Monte Carlo neutrino event generator with the neutrino–electron scattering processes. This new dynamical channel includes the charged current and neutral current interactions, together with their interference, for ν

ℓ

e and

ν

̄

ℓ

e

(ℓ = e, μ, τ) scatterings, resulting in ten possible final states. We illustrate the performance of the new functionality on few physical examples, including an estimation of the background in the T2K ν

μ
→ ν

e
oscillation experiment. We show that the background events arising from the neutrino–electron interactions occupy mostly a distinct region of the phase space and can be easily separated.
Incorporation of Si atoms into CrCoNiFe high-entropy alloy: a DFT study
Authors: Aravindh S Assa , Kistanov Andrey A , Alatalo Matti , Kömi Jukka , Huttula Marko , Cao Wei
Published: January 2021

Density functional theory based computational study has been conducted in order to investigate the effect of substitution of Cr and Co components by Si on the structure, mechanical, electronic, and magnetic properties of the high entropy alloy CrCoNiFe. It is found that the presence of a moderate concentration of Si substitutes (up to 12.5%) does not significantly reduce the structural and mechanical stability of CrCoNiFe while it may modify its electronic and magnetic properties. Based on that, Si is proposed as a cheap and functional material for partial substitution of Cr or Co in CrCoNiFe.
Possible quadrupole order in tetragonal Ba2CdReO6 and chemical trend in the ground states of 5d
1 double perovskites
Authors: Hirai Daigorou , Hiroi Zenji
Published: January 2021

The synthesis and physical properties of the double perovskite (DP) compound Ba2CdReO6 with the 5d
1 electronic configuration are reported. Three successive phases originating from a spin–orbit-entangled J
eff = 3/2 state, confirmed by a reduced effective magnetic moment of 0.72 μ
B, were observed upon cooling. X-ray diffraction measurements revealed a structural transition from a high-temperature cubic structure to a low-temperature tetragonal structure at T
s = 170 K, below which the J
eff = 3/2 state was preserved. Magnetization, heat capacity, and thermal expansion measurements showed two more electronic transitions to a possible quadrupole ordered state at T
q = 25 K and an antiferromagnetic order of dipoles with a ferromagnetic moment of ∼0.2 μ
B at T
m = 12 K. These properties were compared with those of the DP's sister compounds Ba2
BReO6 (B = Mg, Zn, and Ca) and the chemical trend is discussed in terms of the mean-field theory for spin–orbit-coupled 5d electrons (2010 Chen et al Phys. Rev. B
82 174440). The DP Ba2
BReO6 compounds provide a unique opportunity for a systematic investigation of symmetry breaking in the presence of multipolar degrees of freedom.
Superconductivity and strong anharmonicity in novel Nb–S phases
Authors: Lucrezi Roman , Heil Christoph
Published: January 2021

In this work we explore the phase diagram of the binary Nb–S system from ambient pressures up to 250 GPa using ab initio evolutionary crystal structure prediction. We find several new stable compositions and phases, especially in the high-pressure regime, and investigate their electronic, vibrational, and superconducting properties. Our calculations show that all materials, besides the low-pressure phases of pure sulfur, are metals with low electron–phonon (ep) coupling strengths and critical superconducting temperatures below 15 K. Furthermore, we investigate the effects of phonon anharmonicity on lattice dynamics, ep interactions, and superconductivity for the novel high-pressure phase of Nb2S, demonstrating that the inclusion of anharmonicity stabilizes the lattice and enhances the ep interaction.
Probing energy dissipation in molecular-scale junctions via surface enhanced Raman spectroscopy: vibrational pumping and hot carrier enhanced light emission
Authors: Zhu Yunxuan , Natelson Douglas , Cui Longji
Published: January 2021

Experimentally resolving the microscopic energy dissipation and redistribution pathways in a molecular-scale junction, the smallest possible nanoelectronic device, is of great current interest. Here we report measurements of the vibrational pumping and light emission processes in current-carrying molecular junctions using surface enhanced Raman spectroscopy. We show that the heating of vibrational modes exhibits distinct features when the molecular junctions are driven by electrical bias or optical power. We further discuss the hot carrier origin of the broadband continuum emission observed in the Raman scattering spectrum.
Pinning and rotation of a skyrmion in Co nanodisk with nanoengineered point and ring defects
Authors: Song Chengkun , Jin Chendong , Xia Haiyan , Yunxu Ma , Wang Jianing , Liu Qingfang , Wang Jianbo
Published: January 2021

Magnetic skyrmions have been proposed as promising information carriers in the application of spintronics, while the material imperfections are inevitable, thus an understanding of pinning effects on skyrmions in confined geometry is crucial for both fundamental research and development of spintronic devices. Here, we present the interactions of a skyrmion with a point and an extended ring defect, in a Co nanodisk which can be applied in skyrmion oscillator, based on micromagnetic simulations. By comparing with the skyrmion preferred position which is in the nanodisk center without defects, we identify the pinning strength and skyrmion preferred positions with a point defect as a function of skyrmion-defect distance and different local parameters of defect region being considered. The pinning centers range from skyrmion center, domain wall and off-center regions. We find a confinement effect on the skyrmion size with a ring defect. Moreover, we also show the rotation of the skyrmion in the presence of a ring defect, that can lead to a variation of oscillation frequency in a large range. These findings provide a complete understanding of the interaction between skyrmion and defects in a nanodisk and may provide a guidance for the design of skyrmion oscillators.
Enhanced high temperature ferromagnetism in Bi1−x

R

x
FeO3 (R = Dy, Y) compounds
Authors: Zhang N , Ding J Q , Wang Y P , Liu X N , Li Y Q , Liu M F , Fu Z M , Yang Y W , Su J , Song G L , Yang F , Guo Y Y , Liu J-M
Published: January 2021

In this work we report experimental evidence for the weak high-temperature ferromagnetism in Bi1−x

R

x
FeO3 (R = Dy, Y) compounds by systematic characterizations, excluding the possible side-effects from other iron-based impurities. Remarkable saturated magnetic moment was observed in the Y-substituted samples, Bi1−x
Y
x
FeO3, which is larger than the moment obtained in Bi1−x
Dy
x
FeO3, the Dy-substituted samples with antiferromagnetic background. The physical origin of the weak ferromagnetic transition is discussed and serious lattice distortions have been identified based on the x-ray diffraction and Raman scattering data, although the rhombohedral structure symmetry remains unchanged upon the substitutions. It is believed that the structural distortion suppressed cycloid spin structure is the main factor for the enhanced magnetization in Bi1−x

R

x
FeO3 compounds. Additionally, the Dy3+–Fe3+ antiferromagnetic coupling, which strengthens the antiferromagnetic interaction in Bi1−x
Dy
x
FeO3 compounds, acts as the driving force for the magnetic discrepancy between Bi1−x
Y
x
FeO3 and Bi1−x
Dy
x
FeO3 samples.
Magnetic impurity in a triple-component semimetal
Authors: Lee Yu-Li , Lee Yu-Wen
Published: January 2021

We investigate the effects of a magnetic impurity in a multiband touching fermion system, specifically, a triple-component semimetal with a flat band, which can be realized in a family of transition metal silicides (CoSi family). When the chemical potential coincides with the flat band, it is expected that the impurity response of this system will be very different from that of an ordinary Dirac or Weyl semimetal of which the density of states at the Fermi level vanishes. We first determine the phase diagram within the mean-field approximation. Then, we study the local moment regime by employing two different methods. In the low temperature regime, the Kondo screening is analyzed by the variational wavefunction approach and the impurity contributions to the magnetic susceptibility and heat capacity are obtained, while at higher temperature, we use the equation of motion approach to calculate the occupation number of the impurity site and the impurity magnetic susceptibility. The results are compared and contrasted with those in the usual Fermi liquid and the Dirac/Weyl semimetals.