bluuebunny/crossref_metadata_2025 huggingface dataset:
Switching power supply EMC optimisation design method
Authors: Yin Wanjun , Ming ZhengFeng , Wen Tao
Published: May 2020

On the basis of serious electromagnetic interference (EMI) produced by power electronic equipment, parasitic capacitance existing between transistor and heat sink is considered as the main factor disturbing common‐mode loop. Calculation model of parasitic capacitance is established by using finite element method and electrostatic field principle, and computing method is also derived. EMI improvement method for converter system is proposed by controlling the parasitic capacitance impedance. Experimental results show that changing the permittivity and thickness of the thermal conductive adhesive which are filled between the transistor heat‐conducting plate and heat sink to can reduce the conducted interference.
Towards minimum code dissemination delay through UAV joint vehicles for smart city
Authors: Zhao Yongjian , Wang Tian , Zhang Shaobo , Wang Ye
Published: May 2020

In this study, an update code using vehicles joint unmanned aerial vehicle (UC‐VU) scheme is proposed to disseminate code for smart sensing devices (SSDs) in the smart city. The innovations of the UC‐VU scheme are as follows. (i) The unmanned aerial vehicle (UAV) is adopted to disseminate code at the beginning of code dissemination for the SSDs which are difficult to get code through mobile vehicles. Thus, the average delay required for SSDs to get code can be reduced. (ii) Smart storage devices are selected as interim code stations and the strategy of selecting interim code stations’ location and number for code dissemination is proposed to disseminate code efficiently. This makes mobile vehicles can get code from code station for code dissemination which changed the situation where code dissemination is slow due to only one code station disseminates code. (iii) This study also gives the optimisation strategy of the UAV flight trajectory to optimise the flight distance. The key performance indicators such as code dissemination rate compared to previous strategies increases 34.6%, the average dissemination time, the time that all SSDs get the code and the UAV flight trajectory's path decrease by 26.27, 25.30, and 71.67%, respectively.
Iterative learning control for semi‐linear distributed parameter systems based on sensor–actuator networks
Authors: Zhang Jianxiang , Cui Baotong , Lou Xu Yang
Published: May 2020

In this study, the iterative learning control (ILC) method is considered for tracking control of a class of distributed parameter systems (DPSs) based on sensor–actuator networks (SANs) with the unknown exogenous input and the measurement noise, which are described by a semi‐linear parabolic partial differential equation. The D‐type ILC algorithm is presented to control DPSs with non‐collocated SANs. When the unknown exogenous input and the measurement noise are bounded, the upper bounds of output errors are obtained via the Bellman–Gronwall lemma and semi‐group theory, respectively. The authors prove that the output errors converge to zero in the absence of the unknown exogenous input and the measurement noise. Two examples are given to show the effectiveness of the proposed D‐type ILC scheme.
Performance comparisons of alternative permanent‐magnet motor designs for personal mobility‐assistive device applications
Authors: Liu Cheng‐Tsung , Yang Kuan , Wu Yu‐Cheng , Chang He‐Ling , Lee Roger Cheng‐Lung
Published: May 2020

Demands of appropriate personal mobility‐assistive devices for those needed persons have been increased considerably in recent years, with their specific operational requirements, developments of adequate motors to different device parts are the main concerns. For applications onto those knee joint parts of the exoskeleton system, three types of permanent‐magnet (PM) motors, namely the surface‐mounted PM motor, the Vernier motor, and the flux‐switching motor were designed. Based on the operational and physical constraints of the particular exoskeleton parts, optimisations of these PM motors were provided along with their thorough performance comparisons. From emulated finite‐element analyses along with hardware experimental validations, by following the standard test settings, selection guidance for the suitable motor structures at different operational objectives will thus be supplied.
Target segmentation of industrial smoke image based on LBP Silhouettes coefficient variant (LBPSCV) algorithm
Authors: Li Qingrong , Liu Hui , Zhang Junpeng , Zeng Pengfei
Published: May 2020

The use of computer vision technology to analyse the characteristics of smoke such as Ringelmann blackness coefficient and colour information can directly and efficiently reflect the situation of smoke emissions in industrial production, which has great significance in improving air quality. As many factors stand in the way, including the amount and speed of industrial smoke emissions, natural wind speed, illumination etc., an accurate and complete detection of the targeted smoke in images becomes a difficult issue in this field. In this study, a local binary pattern Silhouettes coefficient variant (LBPSCV) is proposed to segment industrial smoke images. The variant of Silhouettes coefficient was used as the weight when calculating the local binary pattern (LBP) feature vector in the LBPSCV. The algorithm overcame the shortcoming that the texture information described by LBP lacks local contrast information, making the extracted texture features more easily to be distinguished between smoke and non‐smoke images. Smoke emission monitoring videos with different characteristics have been used in experiments, such as smoke emission videos with low light, multiple chimney exhaust, multi‐colour smoke etc. The results show that the proposed method has higher detection accuracy and a lower false‐positive rate.
Row‐level algorithm to improve real‐time performance of glass tube defect detection in the production phase
Authors: De Vitis Gabriele A. , Foglia Pierfrancesco , Prete Cosimo A.
Published: May 2020

In the case of the glass tube for pharmaceutical applications, high‐quality defect detection is made via inspection systems based on image processing. Such processing must be fast enough to guarantee real‐time inspection and to meet the increasing rate and quality required by the market. Defect detection is complex due to specific problems of the production process: vibration, rotation and irregularity of the tube. All these aspects prevent the efficient use of known techniques. The authors present an algorithm that decreases the processing time of the defect detection phase. The algorithm is based on a moving average filter working at row level, that allows to minimize the effects of rotation, vibration, and irregularity of the tube. Luminosity variations due to the tube curvature are cut by the filter and a threshold algorithm can be applied. They made the evaluation considering different solutions taken from literature. The algorithm outperforms, in processing time, all these solutions with increased accuracy. Experimental measures show that the algorithm achieves a throughput gain of 2.6 times with respect to Canny. They develop also a methodology to get the best values for the algorithm parameters directly at the factory, during the change of production batches.
Deep learning‐based automated detection of human knee joint's synovial fluid from magnetic resonance images with transfer learning
Authors: Iqbal Imran , Shahzad Ghazala , Rafiq Nida , Mustafa Ghulam , Ma Jinwen
Published: May 2020

As an analytic tool in medicine, particularly in radiology, deep learning is gaining much attention and opening a new way for disease diagnosis. Nonetheless, it is rather challenging to acquire large‐scale detailed labelled datasets in the field of medical imaging. In fact, transfer learning provides a possible way to resolve this issue to a certain extent such that the parameter learning of a neural network starts with its pre‐trained weights learned from a large‐scale dataset of certain similar task, and fine‐tunes on a small comprehensively annotated dataset for the particular target task. The main aim of this study is to apply the deep learning model to detect the synovial fluid of human knee joint from magnetic resonance images. A specialized convolutional neural network architecture is proposed for automated detection of human knee joint's synovial fluid. Two independent datasets are used in the training, development, and evaluation of the proposed model. It is demonstrated by the experimental results that the proposed model obtains high sensitivity, specificity, precision, and accuracy to the detection of human knee joint's synovial fluid. As a result, this proposed approach provides a novel and feasible way for automating and expediting the synovial fluid analysis.
Approach for shadow detection and removal using machine learning techniques
Authors: Shilpa Mohankumar , Gopalakrishna Madigondanahalli Thimmaiah , Naveena Chikkaguddaiah
Published: May 2020

In this work, the authors have proposed a method for shadow detection and removal from videos by utilising methods of machine learning. From literature, various algorithms on shadow detection and removal have been accounted with advantages and disadvantages. Here some algorithms have a need for manual alignment and predefined explicit parameters, but fail to give precise outcome in different lighting and ecological surroundings. In this work, the authors propose a three‐phase framework. In first stage, key frames are chosen by utilising features based K‐means clustering which selects the key frames using features like colour, shape and surface. In second stage, they utilised two‐stage segmentation techniques to segment the shadows by marking the region of interest. In the final step, they use threshold based segmentation to remove the shadow in videos. The performance of the proposed method is compared by performance evaluation of all state‐of‐the‐art methods. The proposed strategies are established to achieve superior results in comparison to other state‐of‐the‐art methods.
Channel modelling of a cooker hob environment for smart kitchens
Authors: De Beelde Brecht , Podevijn Nico , Tanghe Emmeric , Plets David , Dekeyzer Dieter , Joseph Wout
Published: May 2020

This study presents a study on the radio channel modelling for realising reliable wireless communication in kitchen environments. The study allows optimising the wireless communication between a cooking pot and the kitchen hood in a smart home's kitchen. The delay, angular and path loss characteristics of the wireless channel are obtained from channel sounding measurements. The authors compared path loss at frequencies 868 MHz, 2.4 and 5.25 GHz. The influence of the metallic pot on the antenna characteristics is assessed by measuring the radiation pattern of the antenna. The antenna gain increases when the antenna is placed next to the metallic pot. Based on the channel sounding measurements and antenna model, a two‐ray channel model is proposed consisting of one line‐of‐sight component and a component caused by reflections on the hood and hob. For the validation of the proposed model, a narrowband patch antenna is designed and used for measurements in a real kitchen. The validation confirms the general applicability of the proposed method. The results of the joint channel and antenna model are used in link budget calculations. Via the link budget, the minimum required TX power to allow reliable wireless communication is calculated.
Coordinated electric vehicle charging to reduce losses without network impedances
Authors: Crozier Constance , Deakin Matthew , Morstyn Thomas , McCulloch Malcolm
Published: May 2020

This study proposes a method of coordinating electric vehicle charging to reduce losses in a distribution system, using only knowledge of the phase that each charger is connected to. Reducing network losses cuts costs and can be achieved through demand response mechanisms. However, directly minimising losses requires accurate values of the line impedances, which can be difficult to obtain. Flattening load over time and balancing load across phases have both been proposed as alternate solutions which indirectly reduce losses. Here, the practical differences between load flattening and explicitly minimising losses are quantified using simulations of residential charging in European style, three‐phase distribution networks. Then, a new smart charging strategy, which incorporates phase balancing as a secondary objective to load flattening, is proposed. This requires only the knowledge of the phase that each load is on and achieves 30–70% of the potential reduction in losses.
Detection of exomoons in simulated light curves with a regularized convolutional neural network
Authors: Alshehhi Rasha , Rodenbeck Kai , Gizon Laurent , Sreenivasan Katepalli R.
Published: May 2020

Context.Many moons have been detected around planets in our Solar System, but none has been detected unambiguously around any of the confirmed extrasolar planets.

Aims.We test the feasibility of a supervised convolutional neural network to classify photometric transit light curves of planet-host stars and identify exomoon transits, while avoiding false positives caused by stellar variability or instrumental noise.

Methods.Convolutional neural networks are known to have contributed to improving the accuracy of classification tasks. The network optimization is typically performed without studying the effect of noise on the training process. Here we design and optimize a 1D convolutional neural network to classify photometric transit light curves. We regularize the network by the total variation loss in order to remove unwanted variations in the data features.

Results.Using numerical experiments, we demonstrate the benefits of our network, which produces results comparable to or better than the standard network solutions. Most importantly, our network clearly outperforms a classical method used in exoplanet science to identify moon-like signals. Thus the proposed network is a promising approach for analyzing real transit light curves in the future.
Protoplanetary disk masses in NGC 2024: Evidence for two populations
Authors: van Terwisga S. E. , van Dishoeck E. F. , Mann R. K. , Di Francesco J. , van der Marel N. , Meyer M. , Andrews S. M. , Carpenter J. , Eisner J. A. , Manara C. F. , Williams J. P.
Published: May 2020

Context. Protoplanetary disks in dense, massive star-forming regions are strongly affected by their environment. How this environmental impact changes over time is an important constraint on disk evolution and external photoevaporation models.

Aims. We characterize the dust emission from 179 disks in the core of the young (0.5 Myr) NGC 2024 cluster. By studying how the disk mass varies within the cluster, and comparing these disks to those in other regions, we aim to determine how external photoevaporation influences disk properties over time.

Methods. Using the Atacama Large Millimeter/submillimeter Array, a 2.9′× 2.9′ mosaic centered on NGC 2024 FIR 3 was observed at 225 GHz with a resolution of 0.25″, or ~100 AU. The imaged region contains 179 disks identified at IR wavelengths, seven new disk candidates, and several protostars.

Results. The overall detection rate of disks is 32 ± 4%. Few of the disks are resolved, with the exception of a giant (R = 300 AU) transition disk. Serendipitously, we observe a millimeter flare from an X-ray bright young stellar object (YSO), and resolve continuum emission from a Class 0 YSO in the FIR 3 core. Two distinct disk populations are present: a more massive one in the east, along the dense molecular ridge hosting the FIR 1-5 YSOs, with a detection rate of 45 ± 7%. In the western population, towards IRS 1, only 15 ± 4% of disks are detected.

Conclusions. NGC 2024 hosts two distinct disk populations. Disks along the dense molecular ridge are young (0.2–0.5 Myr) and partly shielded from the far ultraviolet radiation of IRS 2b; their masses are similar to isolated 1–3 Myr old SFRs. The western population is older and at lower extinctions, and may be affected by external photoevaporation from both IRS 1 and IRS 2b. However, it is possible these disks had lower masses to begin with.
Extended stellar systems in the solar neighborhood
Authors: Ratzenböck Sebastian , Meingast Stefan , Alves João , Möller Torsten , Bomze Immanuel
Published: May 2020

Context.Nearby stellar streams carry unique information on the dynamical evolution and disruption of stellar systems in the Galaxy, the mass distribution in the disk, and they provide unique targets for planet formation and evolution studies. Recently, Meingast 1, a 120° stellar stream with a length of at least 400 pc, was dicovered.

Aims.We aim to revisit the Meingast 1 stream to search for new members within its currently known 400 pc extent, usingGaiaDR2 data and an innovative machine learning approach.

Methods.We used a bagging classifier of one-class support vector machines withGaiaDR2 data to perform a 5D search (positions and proper motions) for new stream members. The ensemble was created by randomly sampling 2.4 million hyper-parameter realizations admitting classifiers that fulfill a set of prior assumptions. We used the variable prediction frequency resulting from the multitude of classifiers to estimate a stream membership criterion, which we used to select high-fidelity sources. We used the HR diagram and the Cartesian velocity distribution as test and validation tools.

Results.We find about 2000 stream members with high fidelity, or about an order of magnitude more than previously known, unveiling the stream’s population across the entire stellar mass spectrum, from B stars to M stars, including white dwarfs. We find that, apart from being slightly more metal poor, the HRD of the stream is indistinguishable from that of the Pleiades cluster. For the mass range at which we are mostly complete, ∼0.2M⊙ <  M <  ∼4 M⊙, we find a normal IMF, allowing us to estimate the total mass of stream to be about 2000M⊙, making this relatively young stream by far the most massive one known. In addition, we identify several white dwarfs as potential stream members.

Conclusions.The nearby Meingast 1 stream, due to its richness, age, and distance, is a new fundamental laboratory for star and planet formation and evolution studies for the poorly studied and gravitationally unbound star formation mode. We also demonstrate that one-class support vector machines can be effectively used to unveil the full stellar populations of nearby stellar systems withGaiadata.
Future Ultrasound Biomarkers for Sarcopenia: Elastography, Contrast-Enhanced Ultrasound, and Speed of Sound Ultrasound Imaging
Authors: Ivanoski Slavcho , Vasilevska Nikodinovska Violeta
Published: May 2020

Sarcopenia is the advanced and generalized loss of muscle mass and strength among the elderly population and is a cause of adverse outcomes. Methods used for the diagnosis of sarcopenia are either unavailable or expensive in everyday clinical settings. Ultrasound presents an inexpensive, convenient, and available method that offers advantages for the evaluation of skeletal muscle. Muscle quality will probably be the most important factor in defining sarcopenia in the future. Different features of muscle quality, including muscle elasticity, microcirculation and muscle perfusion during rest and physical activity, and the content of intramuscular adipose tissue can be measured using emerging and promising ultrasound techniques such as elastography, contrast-enhanced imaging, and speed of sound ultrasound technology. This article reviews the recent evidence on the use of ultrasound techniques in the assessment of muscle quality and the possibilities for the future evaluation of sarcopenia.
Thromboelastometry Variables in Neonates with Perinatal Hypoxia
Authors: Konstantinidi Aikaterini , Sokou Rozeta , Tsantes Andreas G. , Parastatidou Stavroula , Bonovas Stefanos , Kouskouni Evaggelia , Gounaris Antonios K. , Tsantes Argyrios E. , Iacovidou Nicoletta
Published: May 2020

Perinatal hypoxia is associated with an increased risk of coagulation disorders by enhancing the consumption of platelets and some clotting factors due to the associated severe hypoxemia, acidemia, and compromised oxygen and blood supply to the neonatal liver and bone marrow. Thromboelastometry (TEM), which estimates the dynamics of blood coagulation, may represent an attractive tool for studying the coagulation status of these neonates. We aimed at assessing the hemostatic profile of neonates with perinatal hypoxia using the standard extrinsically activated TEM (ex-TEM) assay. In total, 164 hospitalized neonates with perinatal asphyxia and/or fetal distress comprised the study subjects, and 273 healthy neonates served as controls. Ex-TEM assay was performed, SNAPPE (Score for Neonatal Acute Physiology Perinatal Extension) was calculated, and clinical findings and laboratory results were recorded in all study subjects. Hypoxic neonates expressed a prolonged clotting time (CT) and clot formation time (CFT) and reduced amplitude at 10 minutes (A10), α-angle, and maximum clot firmness compared with healthy neonates. Furthermore, asphyxiated neonates had a significantly prolonged CT and CFT and reduced A10 and α-angle compared with neonates with fetal distress. Hypoxic neonates demonstrate a hypocoagulable ex-TEM profile relative to healthy neonates, indicating a potential role of TEM in the early detection of coagulation derangement in perinatal hypoxia.
Effectiveness of Probiotic Lozenges in Periodontal Management of Chronic Periodontitis Patients: Clinical and Immunological Study
Authors: Alshareef Ahmed , Attia Alaa , Almalki Mohammed , Alsharif Faisal , Melibari Ahmed , Mirdad Bassel , Azab Ehab , Youssef Abdel-Rahman , Dardir Ahmed
Published: May 2020

Objective The main purpose of this article was to evaluate the effect of probiotics used as an adjunctive to scaling and root planing (SRP) on the periodontal parameters and matrix metalloproteinase-8 (MMP-8) levels in gingival crevicular fluid (GCF) of chronic periodontitis patients.

Materials and Methods A total of 25 chronic periodontitis patients who completed the treatment course of 40 subjects, aged 25 to 58 years, participated in this study. They were categorized into two groups: the first group was treated by SRP while the second group was treated by SRP and probiotic lozenges twice a day for 30 days. All patients were evaluated clinically by measuring the plaque index, bleeding index (BI), pocket depth, clinical attachment loss, and immunologically by assaying GCF/MMP-8 at baseline and 30 days after periodontal management.

Results There was a significant improvement in periodontal parameters after SRP treatment with and without probiotic lozenges in both groups. However, there was a significant decrease in the BI (p = 0.05) in SRP and probiotic lozenges group after 30 days compared with SRP alone. In addition, there was a significant decrease in GCF/MMP-8 levels after 30 days in patients managed by SRP only (p = 0.017) compared with the baseline in both groups, whereas a highly significant decrease in patients treated by SRP and probiotics (p = 0.001).

Conclusion The current study suggested that the probiotics might have a beneficial effect on clinical and immunological outcomes in the management of chronic periodontitis patients. Further research is needed on a large-scale population and for a long recall time to confirm the response to probiotics as an adjunctive to SRP.
Ultrasound Imaging Guide for Assessment of the Intrinsic Ligaments Stabilizing the Subtalar and Midtarsal Joints
Authors: Zaottini Federico , Picasso Riccardo , Pistoia Federico , Perez Maribel Miguel , Möller Ingrid , Rossi Federica , Bruns Alessandra , Tagliafico Alberto Stefano , Martinoli Carlo
Published: May 2020

Ligament injuries around the subtalar, talocalcaneonavicular, and calcaneocuboid joints are often underestimated on clinical and imaging findings during investigation of patients with ankle and foot injuries. Because a delayed diagnosis of midtarsal ligament tears may lead to chronic pain and functional disability, an in-depth knowledge of the complex regional anatomy and of the appropriate ultrasound scanning technique is a prerequisite for evaluating these structures and avoiding misdiagnoses. The objective of this article is twofold: to describe the relevant anatomy and biomechanics related to the ligaments that stabilize the subtalar, talocalcaneonavicular, and calcaneocuboid joints, and to illustrate reasoned landmark-based scanning techniques to provide a systematic examination of these ligaments and thus make ultrasound an effective tool for assessment of patients with suspected subtalar or midtarsal sprain.
N95 Filtering Facepiece Respirator Use during Pregnancy: A Systematic Review
Authors: Roeckner Jared T. , Krstić Nevena , Sipe Bradley H. , Običan Sarah G.
Published: May 2020

Objective This study was aimed to systematically review the use of filtering facepiece respirators, such asN95 masks, during pregnancy.

Study Design A comprehensive search for primary literature using Medline, Embase, Scopus, Web of Science, and ClinicalTrials.gov was conducted from inception until April 2020 to find articles reporting outcomes of pregnant women using filtering facepiece respirator (FFR). Studies were selected if they included the use of FFR in pregnant women and reported an outcome of interest including physiologic changes (heart rate, respiratory rate, pulse oximetry, and fetal heart rate tracing) or subjective measures (thermal or exertional discomfort or fit). The Newcastle-Ottawa Quality Assessment scale was used to assess the risk of bias. The main outcome was to describe the physiologic changes in pregnant women compared with nonpregnant women. Due to the small number of studies and heterogeneity of reported outcomes a meta-analysis was not conducted. Results of the studies were synthesized into a summary of evidence table.

Results We identified four studies, three cohort studies and one crossover study, comprising 42 women using FFR during pregnancy. Risk of bias was judged to be low. Studies were consistent in showing no significant increase in maternal heart rate, respiratory rate, oxygen saturation, and fetal heart rate between pregnant and nonpregnant women using N95 FFRs for short durations. Repeat fit testing was not supported for women gaining the recommended amount of weight during pregnancy. No evidence was found to reach conclusions about prolonged N95 FFR use in pregnancy.

Conclusion Limited duration N95 FFR use during pregnancy is unlikely to impart risk to the pregnant women or her fetus.

Key Points
Particle tracking of nanoparticles in soft matter
Authors: Rose Katie A. , Molaei Mehdi , Boyle Michael J. , Lee Daeyeon , Crocker John C. , Composto Russell J.
Published: May 2020

Recent advances in optical microscopy instrumentation and processing techniques have led to imaging that both breaks the diffraction barrier and enables sub-pixel resolution. This enhanced resolution has expanded the capabilities of particle tracking to nanoscale processes in soft matter including biomolecular, colloidal, and polymeric materials. This tutorial provides a basic understanding of particle tracking instrumentation, the fundamentals of tracking analysis, and potential sources of error and bias inherent in analyzing particle tracking. Finally, we provide a brief outlook for the future of particle tracking through the lens of machine learning.
Nuclear quantum effects in state-selective scattering from ring polymer molecular dynamics
Authors: Marjollet Adrien , Welsch Ralph
Published: May 2020

We present an efficient method to obtain initial state-selective cross sections for bimolecular reactions that can account for certain nuclear quantum effects by employing the ring polymer molecular dynamics approach. The method combines the well known quasiclassical trajectory (QCT) approach with the description of the system in an extended ring polymer phase space. Employing the prototypical Mu/H/D + H2(v = 0, 1) reactions as a benchmark, we show that the presented approach does not violate zero-point energy constraints and that it can also capture the contributions of tunneling through the v = 1 vibrationally adiabatic barrier present for the Mu + H2(v = 1) reaction. This is a significant improvement over the QCT approach with only a small increase in numerical cost.
Novel beamline for attosecond transient reflection spectroscopy in a sequential two-foci geometry
Authors: Lucarelli Giacinto D. , Moio Bruno , Inzani Giacomo , Fabris Nicola , Moscardi Liliana , Frassetto Fabio , Poletto Luca , Nisoli Mauro , Lucchini Matteo
Published: May 2020

We present an innovative beamline for extreme ultraviolet (XUV)–infrared (IR) pump–probe reflection spectroscopy in solids with attosecond temporal resolution. The setup uses an actively stabilized interferometer, where attosecond pulse trains or isolated attosecond pulses are produced by high-order harmonic generation in gases. After collinear recombination, the attosecond XUV pulses and the femtosecond IR pulses are focused twice in sequence by toroidal mirrors, giving two spatially separated interaction regions. In the first region, the combination of a gas target with a time-of-flight spectrometer allows for attosecond photoelectron spectroscopy experiments. In the second focal region, an XUV reflectometer is used for attosecond transient reflection spectroscopy (ATRS) experiments. Since the two measurements can be performed simultaneously, precise pump–probe delay calibration can be achieved, thus opening the possibility for a new class of attosecond experiments on solids. Successful operation of the beamline is demonstrated by the generation and characterization of isolated attosecond pulses, the measurement of the absolute reflectivity of SiO2, and by performing simultaneous photoemission/ATRS in Ge.
Manipulating the permittivities and permeabilities of epoxy/silver nanocomposites over a wide bandwidth
Authors: Su Shih-Chieh , Chang Tsun-Hsu
Published: May 2020

The electromagnetic properties of materials are generally frequency-dependent. Controlling the permittivities and permeabilities of composites is commonly achieved in a narrow frequency range. This work characterizes the electromagnetic properties of epoxy/silver nanocomposites using the transmission/reflection method. The silver nanoparticles serving as electric dipoles enhance the permittivity as the volume fraction increases. On the other hand, the rapidly changing magnetic field induces current on the conducting silver particles, resulting in a negative polarizability. The macroscopic magnetic susceptivities are negative under the long-wavelength limit. The electromagnetic properties are controllable and just slightly change over a very broad frequency range from 8 GHz to 110 GHz.
InGaAs/AlAs/GaAs metamorphic asymmetric spacer layer tunnel (mASPAT) diodes for microwaves and millimeter-waves detection
Authors: Salhi A. , Sexton J. , Muttlak S. G. , Abdulwahid O. , Hadfield A. , Missous M.
Published: May 2020

We present work on a novel In0.53Ga0.47As/AlAs metamorphic asymmetric spacer layer tunnel (mASPAT) diode structure, which was grown on GaAs by solid source molecular beam epitaxy. mASPAT diodes with different mesa sizes were fabricated and tested following growth under optimal conditions. The measured I–V characteristics of these tunneling devices showed rectifying behavior resulting from the asymmetric design of the epitaxial spacer layers. The extracted curvature coefficient, junction resistance, and leakage currents at −1 V resulted in an estimated theoretical cut-off frequency ft at zero bias exceeding 180 GHz for 4 × 4 μm2 mesa devices. The obtained results demonstrate the potential use of mASPAT devices on GaAs as a low-cost alternative to devices fabricated on InP substrates for high-volume zero bias microwave and millimeter-wave detectors.
High-throughput and label-free isolation of senescent murine mesenchymal stem cells
Authors: Chen Zhengkun , Jiang Kuan , Zou Zhou , Luo Xiaohe , Lim Chwee Teck , Wen Chunyi
Published: May 2020

Under internal or external insults such as aging and oxidative stresses, cells are induced into a senescent state and stop cellular division permanently. As senescent cells (SnCs) accumulate, the regeneration capacity of biological tissue would be compromised, which has been found to be associated with a plethora of age-related disorders. Therefore, isolating SnCs becomes necessary. To address the lack of effective surface markers for SnCs isolation, a label-free microfluidic device was proposed in this paper, in which a spiral microchannel was deployed to isolate SnCs based on their size differences. We adopted a well-received cellular senescence model by exerting excessive oxidative stress to murine mesenchymal stem cells. This model was then validated through a series of SnCs characterizations including size measurement, p16INK4a expression level, senescence-associated beta-galactosidase, and doubling time. The senescence chip demonstrated an efficiency of 75% and viability over 85% at a flow rate of 5 ml/min. The average cell size from the inner outlet was 5 μm larger than that from the outer outlet. The isolated cells had a sixfold higher p16INK4a expression level. Overall, the chip had an area under curve of 0.719 in the receiver operating characteristic analysis, showing decent performance in sorting SnCs. By having the ability to perform size-based sorting at a high flow rate, such a microfluidic device can provide high-throughput and label-free isolation of SnCs. To further improve the isolation performance, the device can be modified to introduce additional physical biomarkers of SnCs such as stiffness. This device poses a good potential in purification for cytotherapy or estimation of biological age.
Effects of strain and electropulse duration on elastic modulus of TiNi alloy
Authors: Hao J. Y. , Zhang G. S. , Shan W. K. , Li M. , Li K. F. , Gong Z. , Gao Y. W. , Guo D. F.
Published: May 2020

The elastic modulus of TiNi alloy was tailored by electroplastic rolling deformation and the effects of rolling strain and electropulse duration on the elastic modulus of electroplastic rolled TiNi alloy were systematically investigated. With rolling strain increasing from 0 to 1.70, the elastic modulus decreases from 61 to 30 GPa, which can be attributed to the increase in dislocation density and deformation-induced low modulus B19′ martensite phase. With electropulse duration increasing from 80 to 120 µs, the elastic modulus first decreases due to the volume fraction increase in low modulus B19′ martensite phase and then slightly increases on account of the dynamic recovery of dislocation and reverse martensite transformation resulted from electroplastic effect induced by high-energy electropulse.
Structural and functional analyses of organic molecules regulating biomineralization
Authors: Suzuki Michio
Published: May 2020

Biomineralization by living organisms are common phenomena observed everywhere. Molluskan shells are representative biominerals that have fine microstructures with controlled morphology, polymorph, and orientation of CaCO3 crystals. A few organic molecules involved in the biominerals play important roles in the formation of such microstructures. Analyses of structure–function relationships for matrix proteins in biominerals revealed that almost all matrix proteins have an acidic region for the binding of calcium ion in CaCO3 crystals and interaction domains for other organic molecules. On the other hand, biomineralization of metal nanoparticles by microorganisms were also investigated. Gold nanoparticles and quantum dots containing cadmium were successfully synthesized by bacteria or a fungus. The analyses of components revealed that glycolipids, oligosaccharides, and lactic acids have key roles to synthesize the gold nanoparticle in Lactobacillus casei as reductants and dispersants. These researches about biomineralization will give new insights for material and environmental sciences in the human society.
An anti-inflammatory isoflavone from soybean inoculated with a marine fungus Aspergillus terreus C23-3
Authors: Yang Jing-Ming , Liu Ya-Yue , Yang Wen-Cong , Ma Xiao-Xiang , Nie Ying-Ying , Glukhov Evgenia , Gerwick Lena , Gerwick William H , Lei Xiao-Ling , Zhang Yi
Published: May 2020

A new isoflavone derivative compound 1 (psoralenone) was isolated from soybean inoculated with a marine fungus Aspergillus terreus C23-3, together with seven known compounds including isoflavones 2–6, butyrolactone I (7) and blumenol A (8). Their structures were elucidated by MS, NMR, and ECD. Psoralenone displayed moderate in vitro anti-inflammatory activity in the LPS-induced RAW264.7 cell model. Compound 2 (genistein) showed moderate acetylcholinesterase (AChE) inhibitory activity whereas compounds 2, 5 (biochanin A), 6 (psoralenol), and 7 exhibited potent larvicidal activity against brine shrimp. Compounds 3 (daidzein), 4 (4ʹ-hydroxy-6,7-dimethoxyisoflavone), and 5–7 showed broad-spectrum anti-microbial activity, and compound 7 also showed moderate 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity.
Party affiliation and support for Muslim newcomers: masked opposition in the Norwegian context
Authors: Creighton Mathew J. , Strabac Zan
Published: May 2020

This work considers how anti-immigrant sentiment is selectively revealed, offering a new perspective on the role stigma plays in defining the political mainstream. By way of a survey experiment in Norway, we measure the gap between what people express and the beliefs they hold anonymously, assessing how supporters of distinct political parties situationally conform to expectations about the expression of intolerance. Using three frames, we contrast attitudes toward immigrants, refugees and more general types of new entrants to Norway. We conclude that the intolerance is more widespread than openly expressed sentiment would suggest due to the systematic masking of targeted opposition to Muslim newcomers. Covert expression, under conditions of absolute and permanent anonymity, demonstrate hardened sentiment among the mainstream right. In other words, a large shift in covert attitudes is best understood as a shift in deference to norms about the expression of targeted bias – in this case toward Muslim newcomers – rather than a large change in underlying, anonymously expressed attitudes.
PD-1 and BTLA regulate T cell signaling differentially and only partially through SHP1 and SHP2
Authors: Xu Xiaozheng , Hou Bowen , Fulzele Amitkumar , Masubuchi Takeya , Zhao Yunlong , Wu Zijun , Hu Yanyan , Jiang Yong , Ma Yanzhe , Wang Haopeng , Bennett Eric J. , Fu Guo , Hui Enfu
Published: May 2020

Blockade antibodies of the immunoinhibitory receptor PD-1 can stimulate the anti-tumor activity of T cells, but clinical benefit is limited to a fraction of patients. Evidence suggests that BTLA, a receptor structurally related to PD-1, may contribute to resistance to PD-1 targeted therapy, but how BTLA and PD-1 differ in their mechanisms is debated. Here, we compared the abilities of BTLA and PD-1 to recruit effector molecules and to regulate T cell signaling. While PD-1 selectively recruited SHP2 over the stronger phosphatase SHP1, BTLA preferentially recruited SHP1 to more efficiently suppress T cell signaling. Contrary to the dominant view that PD-1 and BTLA signal exclusively through SHP1/2, we found that in SHP1/2 double-deficient primary T cells, PD-1 and BTLA still potently inhibited cell proliferation and cytokine production, albeit more transiently than in wild type T cells. Thus, PD-1 and BTLA can suppress T cell signaling through a mechanism independent of both SHP1 and SHP2.
Etiological Kinds
Authors: Khalidi Muhammad Ali
Published: May 2020

Kinds that share historical properties are dubbed “historical kinds” or “etiological kinds,” and they have some distinctive features. I will try to characterize etiological kinds in general terms and briefly survey some previous philosophical discussions of these kinds. Then I will take a closer look at a few case studies involving different types of etiological kinds. Finally, I will try to understand the rationale for classifying on the basis of etiology, putting forward reasons for classifying phenomena on the basis of diachronic features, thereby making a provisional case for considering at least some etiological kinds to be natural kinds.
Compressibility and the Reality of Patterns
Authors: Millhouse Tyler
Published: May 2020

Daniel Dennett distinguishes real patterns from bogus patterns by appeal to compressibility. As information theorists have shown, data are compressible if and only if those data exhibit a pattern. Noting that high-level models are much simpler than their low-level counterparts, Dennett interprets high-level models as compressed representations of the fine-grained behavior of their target system. As such, he argues that high-level models depend on patterns in this behavior. Unfortunately, data scientific practice complicates Dennett’s interpretation, undermining the traditional justification for real patterns and suggesting a revised research program for its defenders.
CALET on the International Space Station: the first three years of observations
Authors: Brogi P , Adriani O , Akaike Y , Asano K , Asaoka Y , Bagliesi M G , Berti E , Bigongiari G , Binns W R , Bonechi S , Bongi M , Bruno A , Buckley J H , Cannady N , Castellini G , Checchia C , Cherry M L , Collazuol G , Di Felice V , Ebisawa K , Fuke H , Guzik T G , Hams T , Hibino K , Ichimura M , Ioka K , Ishizaki W , Israel M H , Kasahara K , Kataoka J , Kataoka R , Katayose Y , Kato C , Kawanaka N , Kawakubo Y , Kohri K , Krawczynski H S , Krizmanic J F , Link J , Maestro P , Marrocchesi P S , Messineo A M , Mitchell J W , Miyake S , Moiseev A A , Mori M , Mori N , Motz H M , Munakata K , Murakami H , Nakahira S , Nishimura J , de Nolfo G A , Okuno S , Ormes J F , Ospina N , Ozawa S , Pacini L , Palma F , Papini P , Rauch B F , Ricciarini S B , Sakai K , Sakamoto T , Sasaki M , Shimizu Y , Shiomi A , Sparvoli R , Spillantini P , Stolzi F , Sugita S , Suh J E , Sulaj A , Takahashi I , Takita M , Tamura T , Terasawa T , Torii S , Tsunesada Y , Uchihori Y , Vannuccini E , Wefel J P , Yamaoka K , Yanagita S , Yoshida A , Yoshida K
Published: May 2020

The CALorimetric Electron Telescope CALET is a space instrument designed to carry out precision measurements of high energy cosmic-rays on the JEM-EF external platform on the International Space Station, where it has been collecting science data continuously since mid October 2015. In addition to its primary goal of identifying nearby sources of high-energy electrons and possible signatures of dark matter in the electron spectrum, CALET is carrying out extensive measurements of the energy spectra, relative abundances and secondary-to-primary ratios of elements from proton to iron, and even above (up to Z = 40), studying the details of galactic particle propagation and acceleration. An overview of CALET based on the data taken during the first three years of observations is presented, including a direct measurement of the electron+positron energy spectrum from 11 GeV to 4.8 TeV. The proton spectrum has been measured from 50 GeV to 10 TeV covering, for the first time with a single space-borne instrument, the whole energy interval previously investigated in separate sub-ranges by magnetic spectrometers and calorimetric instruments. Preliminary spectra of cosmic-ray nuclei are also presented, together with gamma-ray observations and searches for an e.m. counterpart of LIGO/Virgo GW events.
Enhanced dielectric properties of green synthesized Nickel Sulphide (NiS) nanoparticles integrated polyvinylalcohol nanocomposites*
Authors: Reddy P Lokanatha , Deshmukh Kalim , Kovářík Tomáš , Reiger David , Nambiraj N Arunai , R Lakshmipathy , S K Khadheer Pasha
Published: May 2020

A green synthesis approach has been adopted to prepare nickel sulphide nanoparticles (NiS NPs) using banana peel extract (BPE) as a reducing and capping agent. Polyvinyl alcohol (PVA)/NiS nanocomposite films were fabricated using a cost-effective solution casting technique by dispersing different contents of NiS NPs (0–3 wt%) in the PVA matrix. Various characterization techniques were employed to analyze the structural, thermal and morphological properties of the PVA/NiS nanocomposite films. Further, the dielectric behaviour of these nanocomposite films was investigated at frequency range 50 Hz–20 MHz and in the temperature range 40 °C–140 °C. Also, there exists a significant interaction between the polymer matrix and the nanofiller as evident from the notable improvement in the dielectric properties of the nanocomposites. The dielectric constant (ε) value of PVA/NiS nanocomposite film with 3 wt % NiS NPs loading was found to be 154.55 at 50 Hz and at 140 °C which is 22 times greater than the dielectric constant value of neat PVA (6.90). These results suggest that NiS NPs were dispersed homogeneously in the PVA matrix.
Efficient loading of silver nanoparticles on graphene oxide and its antibacterial properties
Authors: Wang Hui , Zhang Yalei , Xu Xiaobing , Yang Feiyao , Li Ke , Wei Di , Liu Zhongfan
Published: May 2020

Graphene oxide contains polyaromatic structure and a variety of oxygen functional groups, which can form π-type metal ion-aromatic or metal ion-oxygen interaction with transition metals, thus it is a promising dispersant and carrier for silver nanoparticles (AgNPs). Herein, silver nanoparticles/reduced graphene oxide (AgNPs/rGO) was fabricated with scalable synthesis method without additional dispersing agent. The mass percent of AgNPs loading on rGO could be adjusted according to the requirement of applications from 1 ∼ 67% of the total weight of AgNPs/rGO with the sizes of AgNPs 10 ∼ 30 nm. AgNPs/rGO exhibited excellent antibacterial activity towards both gram-positive S. aureus and gram-negative E. coli. In addition, AgNPs/rGO could be easily dispersed in liquid silicone rubber, and when the rubber solidified and formed a three-dimensional structure, AgNPs/rGO-silicone rubber has both effective antibacterial property and very low effusion of AgNPs. This composite has potential to be used as a material of bacteriostasis bottles and wound dressings.
Large time behavior, bi-Hamiltonian structure, and kinetic formulation for a complex Burgers equation
Authors: Gao Yu , Gao Yuan , Liu Jian-Guo
Published: May 2020

We prove the existence and uniqueness of positive analytical solutions with positive initial data to the mean field equation (the Dyson equation) of the Dyson Brownian motion through the complex Burgers equation with a force term on the upper half complex plane. These solutions converge to a steady state given by Wigner’s semicircle law. A unique global weak solution with nonnegative initial data to the Dyson equation is obtained, and some explicit solutions are given by Wigner’s semicircle laws. We also construct a bi-Hamiltonian structure for the system of real and imaginary components of the complex Burgers equation (coupled Burgers system). We establish a kinetic formulation for the coupled Burgers system and prove the existence and uniqueness of entropy solutions. The coupled Burgers system in Lagrangian variable naturally leads to two interacting particle systems, the Fermi–Pasta–Ulam–Tsingou model with nearest-neighbor interactions, and the Calogero–Moser model. These two particle systems yield the same Lagrangian dynamics in the continuum limit.