bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel method to realize a non-uniform heat flux distribution through the variable-speed scanning of an electron beam
Authors: Zheng Chuanmao , Yao Hongxin , Wang Xiyao , Ye Hong 
Published: June 2021

AbstractQuartz lamp heaters and hypersonic wind tunnel are currently applied in thermal assessment of heat resistant materials and surface of aircraft. However, it is difficult to achieve precise heat flux distribution by quartz lamp heaters, while enormous energy is required by a large scale hypersonic wind tunnel. Electron beam can be focused into a beam spot of millimeter scale by an electromagnetic lens and electron-magnetically deflected to achieve a rapid scanning over a workpiece. Moreover, it is of high energy utilization efficiency when applying an electron beam to heat a metal workpiece. Therefore, we propose to apply an electron beam with a variable speed to establish a novel method to realize various non-uniform heat flux boundary conditions. Besides, an electron beam thermal assessment equipment is devised. To analyze the feasibility of this method, an approach to calculate the heat flux distribution formed by an electron beam with variable-speed scanning is constructed with beam power, diameter of the beam spot and dwell duration of the electron beam at various locations as the key parameters. To realize a desired non-uniform heat flux distribution of the maximum gradient of 1.1 MW/m3, a variable-speed scanning strategy is constructed on basis of the conservation of energy. Compared with the desired heat flux, the maximum deviation of the scanned heat flux is 4.5% and the deviation in the main thermal assessment area is less than 3%. To verify the method, taking the time-average scanned heat flux as the boundary condition, a heat transfer model is constructed and temperature results are calculated. The experiment of variable-speed scanning of an electron beam according to the scanning strategy has been carried out. The measured temperatures are in good agreement with the predicted results at various locations. Temperature fluctuation during the scanning process is analyzed, and it is found to be proportional to the scanned heat flux divided by volumetric heat capacity, which is applicable for different materials up to 3.35 MW/m2. This study provides a novel and effective method for precise realization of various non-uniform heat flux boundary conditions.
Morphological change of coiled bacterium Spirosoma linguale with acquisition of β-lactam resistance
Authors: Maeda Tomoya , Kotani Hazuki , Furusawa Chikara 
Published: June 2021

AbstractSpirosoma linguale is a gram-negative, coiled bacterium belonging to the family Cytophagaceae. Its coiled morphology is unique in contrast to closely related bacteria belonging to the genus Spirosoma, which have a short, rod-shaped morphology. The mechanisms that generate unique cell morphology are still enigmatic. In this study, using the Spirosoma linguale ATCC33905 strain, we isolated β-lactam (cefoperazone and amoxicillin)-resistant clones. These clones showed two different cell morphological changes: relatively loosely curved cells or small, horseshoe-shaped cells. Whole-genome resequencing analysis revealed the genetic determinants of β-lactam resistance and changes in cell morphology. The loose-curved clones commonly had mutations in Slin_5958 genes encoding glutamyl-tRNA amidotransferase B subunit, whereas the small, horseshoe-shaped clones commonly had mutations in either Slin_5165 or Slin_5509 encoding pyruvate dehydrogenase (PDH) components. Two clones, CFP1ESL11 and CFL5ESL4, which carried only one mutation in Slin_5958, showed almost perfectly straight, rod-shaped cells in the presence of amoxicillin. This result suggests that penicillin-binding proteins targeted by amoxicillin play an important role in the formation of a coiled morphology in this bacterium. In contrast, supplementation with acetate did not rescue the growth defect and abnormal cell size of the CFP5ESL9 strain, which carried only one mutation in Slin_5509. These results suggest that PDH is involved in cell-size maintenance in this bacterium.
Oncological evaluation in the perioperative period using cfDNA with BRAF V600E mutation in patients with colorectal cancer
Authors: Tanaka Keita , Yoshida Yoichiro , Yamada Teppei , Hayashi Takaomi , Shimaoka Hideki , Yoshimura Fumihiro , Kajitani Ryuji , Munechika Taro , Matsumoto Yoshiko , Nagano Hideki , Komono Akira , Sakamoto Ryohei , Nakashima Ryo , Aisu Naoya , Yoshimatsu Gumpei , Hasegawa Suguru 
Published: June 2021

AbstractThe detection of circulating cell-free DNA (cfDNA) by liquid biopsy is reported to provide prognostic information in colorectal cancer (CRC). Although the frequency of BRAF V600E mutation in CRC is less than 10%, it is associated with poor responses to conventional chemotherapy. We conducted a prospective study to investigate the relationship between the perioperative mutant allele frequency (MAF) of BRAF V600E and tumor recurrence, and to evaluate the possibility of early detection of recurrence. Among 362 patients who underwent radical resection, cfDNA was extracted from the perioperative blood of 11 CRC patients with BRAF V600E mutation and analyzed using the digital polymerase chain reaction (dPCR) system. The median follow-up time was 22 months, and there were four cases of recurrence. Although there was no correlation between recurrence and the perioperative MAF of BRAF V600E, tumor diameter was correlated with the MAF (p = 0.024), and the MAF increased with time in two patients from whom additional samples were obtained prior to recurrence. In this study, we identified a correlation between the pathological tumor diameter and the MAF, but it was difficult to predict recurrence by measuring cfDNA with BRAF V600E mutation in the perioperative period of radical resection of CRC.
Impact of model resolution on the representation of the wind field along Nares Strait
Authors: Moore G. W. K. 
Published: June 2021

AbstractNares Strait is a major pathway along which multi-year sea ice leaves the Arctic, an ice class that has seen a recent dramatic reduction in extent. The winds that blow along the strait play an important role in modulating this ice export as well as in establishing the Arctic’s largest and most productive polynya, the North Water, that forms at its southern terminus. However, its remote location has limited our knowledge of the winds along the strait. Here we use automatic weather station data from Hans Island, in the middle of the strait, to assess the ability of a set of atmospheric renalyses and analyses with a common lineage but with varying horizontal resolution to represent the variability in the wind field. We find that the flow is highly bidirectional, consistent with topographic channeling, with the highest wind speeds from the north and that a model resolution of ~ 9 km is required to capture the observed variability. The wind field at Hans Island is also found to be representative of variability in the flow along much of Nares Strait.
Relaxation processes in silicon heterojunction solar cells probed via noise spectroscopy
Authors: Davenport Kevin , Trinh C. T. , Hayward Mark , Lips Klaus , Rogachev Andrey 
Published: June 2021

AbstractWe have employed state-of-the-art cross-correlation noise spectroscopy (CCNS) to study carrier dynamics in silicon heterojunction solar cells (SHJ SCs). These cells were composed of a light absorbing n-doped monocrystalline silicon wafer contacted by passivating layers of i-a-Si:H and doped a-Si:H selective contact layers. Using CCNS, we are able to resolve and characterize four separate noise contributions: (1) shot noise with Fano factor close to unity due to holes tunneling through the np-junction, (2) a 1/f term connected to local potential fluctuations of charges trapped in a-Si:H defects, (3) generation-recombination noise with a time constant between 30 and 50 μs and attributed to recombination of holes at the interface between the ITO and n-a-Si:H window layer, and (4) a low-frequency generation-recombination term observed below 100 K which we assign to thermal emission over the ITO/ni-a-Si:H interface barrier. These results not only indicate that CCNS is capable of reveling otherwise undetectable relaxation process in SHJ SCs and other multi-layer devices, but also that the technique has a spatial selectivity allowing for the identification of the layer or interface where these processes are taking place.
Resolving cell state in iPSC-derived human neural samples with multiplexed fluorescence imaging
Authors: Tomov Martin L. , O’Neil Alison , Abbasi Hamdah S. , Cimini Beth A. , Carpenter Anne E. , Rubin Lee L. , Bathe Mark 
Published: June 2021

AbstractHuman induced pluripotent stem cell-derived (iPSC) neural cultures offer clinically relevant models of human diseases, including Amyotrophic Lateral Sclerosis, Alzheimer’s, and Autism Spectrum Disorder. In situ characterization of the spatial-temporal evolution of cell state in 3D culture and subsequent 2D dissociated culture models based on protein expression levels and localizations is essential to understanding neural cell differentiation, disease state phenotypes, and sample-to-sample variability. Here, we apply PRobe-based Imaging for Sequential Multiplexing (PRISM) to facilitate multiplexed imaging with facile, rapid exchange of imaging probes to analyze iPSC-derived cortical and motor neuron cultures that are relevant to psychiatric and neurodegenerative disease models, using over ten protein targets. Our approach permits analysis of cell differentiation, cell composition, and functional marker expression in complex stem-cell derived neural cultures. Furthermore, our approach is amenable to automation, offering in principle the ability to scale-up to dozens of protein targets and samples.
An integrated framework for quantifying immune-tumour interactions in a 3D co-culture model
Authors: Al-Hity Gheed , Yang FengWei , Campillo-Funollet Eduard , Greenstein Andrew E. , Hunt Hazel , Mampay Myrthe , Intabli Haya , Falcinelli Marta , Madzvamuse Anotida , Venkataraman Chandrasekhar , Flint Melanie S. 
Published: June 2021

AbstractInvestigational in vitro models that reflect the complexity of the interaction between the immune system and tumours are limited and difficult to establish. Herein, we present a platform to study the tumour-immune interaction using a co-culture between cancer spheroids and activated immune cells. An algorithm was developed for analysis of confocal images of the co-culture to evaluate the following quantitatively; immune cell infiltration, spheroid roundness and spheroid growth. As a proof of concept, the effect of the glucocorticoid stress hormone, cortisol was tested on 66CL4 co-culture model. Results were comparable to 66CL4 syngeneic in vivo mouse model undergoing psychological stress. Furthermore, administration of glucocorticoid receptor antagonists demonstrated the use of this model to determine the effect of treatments on the immune-tumour interplay. In conclusion, we provide a method of quantifying the interaction between the immune system and cancer, which can become a screening tool in immunotherapy design.
Nuclear factor E2-related factor 2 (NRF2) deficiency accelerates fast fibre type transition in soleus muscle during space flight
Authors: Hayashi Takuto , Kudo Takashi , Fujita Ryo , Fujita Shin-ichiro , Tsubouchi Hirona , Fuseya Sayaka , Suzuki Riku , Hamada Michito , Okada Risa , Muratani Masafumi , Shiba Dai , Suzuki Takafumi , Warabi Eiji , Yamamoto Masayuki , Takahashi Satoru 
Published: June 2021

AbstractMicrogravity induces skeletal muscle atrophy, particularly in the soleus muscle, which is predominantly composed of slow-twitch myofibre (type I) and is sensitive to disuse. Muscle atrophy is commonly known to be associated with increased production of reactive oxygen species. However, the role of NRF2, a master regulator of antioxidative response, in skeletal muscle plasticity during microgravity-induced atrophy, is not known. To investigate the role of NRF2 in skeletal muscle within a microgravity environment, wild-type andNrf2-knockout (KO) mice were housed in the International Space Station for 31 days. Gene expression and histological analyses demonstrated that, under microgravity conditions, the transition of type I (oxidative) muscle fibres to type IIa (glycolytic) was accelerated inNrf2-KO mice without affecting skeletal muscle mass. Therefore, our results suggest that NRF2 affects myofibre type transition during space flight.
Stable organic self-assembled microwire lasers for chemical vapor sensing
Authors: Chen Zheming , Dai Chenghu , Xiong Wei , Che Yanke , Zhang Chuang 
Published: June 2021

AbstractOrganic microlasers hold great potentials in fabricating on-chip sensors for integrated photonic circuits due to their chemical versatility and reactivity. However, chemical vapor detection is still challenging for organic microlaser sensors, as it requires not only optical gain and self-assembly capability, but also rapid response to stimuli and long-term stability under high excitation power. In this work, a new laser dye 4,7-bis(9-octyl-7-(4-(octyloxy)phenyl)-9H-carbazol-2-yl)benzo[c][1,2,5]thiadiazole (BPCBT) is designed and synthesized, which self-assembles into microwires showing strong intramolecular charge transfer (ICT) photoluminescence with >80% quantum efficiency. It enables the lasing from BPCBT microwires under a low threshold of 16 μJ·mm−2·pulse−1 with significantly improved stability over conventional organic microlasers. The stimulated emission amplifies the fluorescence change in the BPCBT microwires under chemical vapors including various acid, acetone, and ethanol vapors, indicating high sensitivity and high selectivity of organic microlaser sensors desirable for compact sensor arrays in integrated photonics.
Superconducting insulators and localization of Cooper pairs
Authors: Arutyunov Konstantin Yu. , Lehtinen Janne S. , Radkevich Alexey , Semenov Andrew G. , Zaikin Andrei D. 
Published: June 2021

AbstractRapid miniaturization of electronic devices and circuits demands profound understanding of fluctuation phenomena at the nanoscale. Superconducting nanowires – serving as important building blocks for such devices – may seriously suffer from fluctuations which tend to destroy long-range order and suppress superconductivity. In particular, quantum phase slips (QPS) proliferating at low temperatures may turn a quasi-one-dimensional superconductor into a resistor or an insulator. Here, we introduce a physical concept of QPS-controlled localization of Cooper pairs that may occur even in uniform nanowires without any dielectric barriers being a fundamental manifestation of the flux-charge duality in superconductors. We demonstrate – both experimentally and theoretically – that deep in the “insulating” state such nanowires actually exhibit non-trivial superposition of superconductivity and weak Coulomb blockade of Cooper pairs generated by quantum tunneling of magnetic fluxons across the wire.
Dominant role of vertical air flows in the unprecedented warming on the Antarctic Peninsula in February 2020
Authors: Xu Min , Yu Lejiang , Liang Kaixin , Vihma Timo , Bozkurt Deniz , Hu Xiaoming , Yang Qinghua 
Published: June 2021

AbstractNear-surface air temperature at the Argentinian research base Esperanza on the northern tip of the Antarctic Peninsula reached 18.3 °C on 6 February 2020, which is the highest temperature ever recorded on the entire Antarctic continent. Here we use weather observations since 1973 together with the ERA5 reanalysis to investigate the circulation that shaped the 2020 event, and its context over the past decades. We find that, during the 2020 event, a high-pressure ridge over the 40°-100°W sector and a blocking high on the Drake Passage led to an anticyclonic circulation that brought warm and moist air from the Pacific Ocean to the Antarctic Peninsula. Vertical air flows in a foehn warming event dominated by sensible heat and radiation made the largest contribution to the abrupt warming. A further analysis with 196 extreme warm events in austral summer between 1973 and 2020 suggests that the mechanisms behind the 2020 event form one of the two most common clusters of the events, exhibiting that most of the extreme warm events at Esperanza station are linked to air masses originating over the Pacific Ocean.
Candidate box fusion based approach to adjust position of the candidate box for object detection
Authors: Cao Jie , Ren Wei , Zhang Hong , Chen Zuohan 
Published: June 2021

AbstractThe method of object detection has been applied to all aspects
in our lives. Although object detection methods based on deep learning have
been widely used in various fields, there are still some overlooked problems in
the candidate box selection stage. The detection results of traditional
candidate box selection methods can only select a relatively optimal maximum
candidate box. If the maximum candidate box is still not accurate enough, this
type of methods will not be able to do adjust it. To solve this problem, an
object detection method based on the multiple candidate box fusion is proposed.
The method can not only retain the maximum candidate box and delete the non‐maximum
candidate box, but also adjust the position of the maximum candidate box again.
Thereby a more accurate maximum candidate box can be obtained. In order to
verify the generalization ability of the method, the candidate box fusion
method is combined with the two object detection frameworks: faster R‐CNN model and
YOLOv3 model. The results of these experiments prove that the proposed method
can achieve higher detection accuracy and complete the object detection task
more effectively.
Limits on the contribution of early endogenous radiolysis to oxidation in carbonaceous chondrites’ parent bodies
Authors: Bouquet Alexis , Miller Kelly E. , Glein Christopher R. , Mousis Olivier 
Published: June 2021

Context.Carbonaceous chondrites have undergone alteration in their parent bodies and display oxidized secondary phases, including sulfates in CI and CM chondrites. The cause of the formation of these sulfates is yet to be determined.Aims.This study investigates the potential of endogenous radiolysis of water (i.e., radiolysis caused by radionuclides present in the rock) on the parent bodies of carbonaceous chondrites. Radiolysis may have contributed to the enhanced degree of oxidation of CI and CM chondrites, and we also examined CV chondrites as a case with no measured sulfates.Methods.We quantified the oxidants produced by radiolysis and how much of the sulfur content could be oxidized to form sulfates by this method. The amount of oxidants was calculated using a radiolytic production model developed and used for Earth and planetary applications that takes into account relevant physical parameters (water-to-rock ratio, grain density) and composition (amount of radionuclides, sulfur content).Results.For CM and CI parent bodies, even using a very favorable set of assumptions, only slightly more than 1% of the available sulfur can be oxidized into sulfates by this process, significantly below the amount of sulfates observed in these chondrites.Conclusions.Endogenous radiolysis is unlikely to have significantly contributed to the abundance of sulfate in CI and CM meteorites. The hypothesis of oxidation of sulfur by large quantities of O2accreted with primitive ice, on the other hand, is quantitatively supported by measurements of O2in comet 67P/Churyumov-Gerasimenko.
A new delegation design for EU governance: how preference cohesiveness of multiple principals shapes the European Commission’s discretion in trade negotiations
Authors: Heldt Eugenia C. 
Published: June 2021

AbstractThe Lisbon Treaty enhanced the role of the European Parliament in free trade agreements. This article offers a comprehensive theoretical and empirical account of this new delegation design in EU trade governance. Specifically, it addresses the question how the preference cohesiveness of multiple principals—the Council of Ministers as a de jure principal and the Parliament as a de facto principal—shapes the Commission’s discretion in negotiating trade agreements. Exploring these two conjectures through a combination of primary materials and interviews, this contribution posits that those configurations of low degree of cohesiveness within the Council and high cohesiveness within the Parliament or high cohesiveness of the Council and low cohesiveness within the Parliament increase Commission discretion. A configuration of low cohesiveness within and between multiple principals, by contrast, is more likely to lead to paralysis of the negotiation process.
The effect of the duration of treatment with antioxidants on age-related hearing loss
Authors: Mohammadkhani Ghassem , Tavanai Elham 
Published: June 2021

Background and aims
The effect of antioxidants depends on several factors, including the type, dose, timing, and treatment duration. Several studies have demonstrated that antioxidants can prevent age-related hearing loss (ARHL), however, a few studies have focussed on the role of factors influencing the effects of antioxidant therapy. This study aimed to investigate the effect of duration of treatment on ARHL using an herbal antioxidant, silymarin, in a D-galactose-induced ageing rat model.

Method
40 three-months-old Wistar rats were divided into four groups: a short-term silymarin-treated group that received 500 mg/kg/day D-galactose (8 consecutive weeks) +200 mg/kg/day silymarin (4 consecutive weeks), long-term silymarin-treated group received 500 mg/kg/day D-galactose (8 consecutive weeks)+ 200 mg/kg/day silymarin (8 consecutive weeks), placebo group received 500 mg/kg/day D-galactose + placebo (propylene glycol; 8 consecutive weeks), and control group received normal saline (8 consecutive weeks). Auditory Brainstem Response (ABR) was measured at 4, 8, 12, and 16 kHz frequencies before and after the intervention.

Results
No significant differences were found in ABR absolute and inter-peak latencies between groups. In contrast, there was a significant difference in ABR threshold shift between the placebo and the long-term silymarin-treated groups at 4 and 16 kHz frequencies (p ≤ .05), but without a similar difference through comparison with the short-term silymarin-treated group (p > .05). Additionally, a significant decrease in ABR amplitude of PI and PII was observed in the placebo group at 4 kHz frequency compared to the long-term silymarin-treated group (p ≤ .05), but not to the short-term silymarin-treated group (p > .05).

Conclusion
The present study results indicate that the duration of treatment with antioxidants influences the successful prevention and treatment of ARHL. Consequently, this factor must be considered in the antioxidant therapy of ARHL. However, further studies are required to fully evaluate the effects of optimal treatment duration with antioxidants on ARHL along with the other influencing factors.
Current-induced H-shaped-skyrmion creation and their dynamics in the helical phase
Authors: Knapman R , Rodrigues D R , Masell J , Everschor-Sitte K 
Published: June 2021

Abstract
Inevitable for the basic principles of skyrmion racetrack-like applications is not only their confined motion along one-dimensional channels but also their controlled creation and annihilation. Helical magnets have been suggested to naturally confine the motion of skyrmions along the tracks formed by the helices, which also allow for high-speed skyrmion motion. We propose a protocol to create topological magnetic structures in a helical background. We furthermore analyse the stability and current-driven motion of the skyrmions in a helical background with in-plane uniaxial anisotropy fixing the orientation of the helices.