bluuebunny/crossref_metadata_2025 huggingface dataset:
Morroniside regulates hair growth and cycle transition via activation of the Wnt/β-catenin signaling pathway
Authors: Zhou Lijuan , Wang Han , Jing Jing , Yu Lijuan , Wu Xianjie , Lu Zhongfa
Published: September 2018

Hair loss is characterized by a shortened hair anagen phase and hair follicles (HF) miniaturization. Morroniside is the most abundant iridoid glycoside extracted from Cornus officinalis and has various bioactivities in different cell functions and tissue regeneration. In this study, we investigated the effects and the underlying mechanism of morroniside on hair growth and regulation of HF cycle transition. Morroniside treatment significantly enhanced outer root sheath cell (ORSC) proliferation and migration in vitro. Additionally, morroniside upregulated Wnt10b, β-catenin and lef1. The enhanced ORSC proliferation and migration due to morroniside treatment were partly rescued by a Wnt/β-catenin signaling inhibitor, DKK1. Furthermore, in a hair-induced mouse model, morroniside injection accelerated the onset of anagen and delayed HF catagen, as shown by histological examination. Immunohistochemical analyses revealed that Wnt/β-catenin signaling pathway expression was upregulated in the HFs. These findings suggest that morroniside regulates HF growth and development partly through the Wnt/β-catenin signaling pathway and may be a potential treatment for hair loss.
Pollination niche availability facilitates colonization of Guettarda speciosa with heteromorphic self-incompatibility on oceanic islands
Authors: Xu Yuanqing , Luo Zhonglai , Gao Shaoxiong , Zhang Dianxiang
Published: September 2018

Obligate out-breeding plants are considered relatively disadvantageous comparing with self-breeding plants when colonizing oceanic islets following long-distance dispersal owing to mate and pollinator limitation. The rarity of heterostyly, a typical out-breeding system, on oceanic islands seems a good proof. However, a heterostylous plant, Guettarda speciosa, is widely distributed on most tropical oceanic islets. Our research demonstrates that its heteromorphic self-incompatibility, plus herkogamy and long flower tube make it rely on pollinator for sexual reproduction, which is generally considered “disadvantageous” for island colonization. We hypothesize that available pollination niche will be a key factor for its colonization on islands. Our studies on remote coral islands show that G. speciosa has built equilibrium population with a 1:1 morph ratio. It could obtain pollination niche from the hawkmoth Agrius convolvuli. A pioneer island plant Ipomoea pes-caprae sustain the pollination niche by providing trophic resource for the larvae of the pollinator. Geographic pattern drawn by Ecological Niche Modelling further indicates the interaction between G. speciosa, A. convolvuli and I. pes-caprae can be bounded on those remote oceanic islands, explaining the colonization of G. speciosa distylous population. These findings demonstrated obligate out-breeding system could be maintained to acclimatize long distance dispersal, if the pollination niche is available.
Method for immobilization of living and synthetic cells for high-resolution imaging and single-particle tracking
Authors: Syga Łukasz , Spakman Dian , Punter Christiaan M. , Poolman Bert
Published: September 2018

Super-resolution imaging and single-particle tracking require cells to be immobile as any movement reduces the resolution of the measurements. Here, we present a method based on APTES-glutaraldehyde coating of glass surfaces to immobilize cells without compromising their growth. Our method of immobilization is compatible with Saccharomyces cerevisiae, Escherichia coli, and synthetic cells (here, giant-unilamellar vesicles). The method introduces minimal background fluorescence and is suitable for imaging of single particles at high resolution. With S. cerevisiae we benchmarked the method against the commonly used concanavalin A approach. We show by total internal reflection fluorescence microscopy that modifying surfaces with ConA introduces artifacts close to the glass surface, which are not present when immobilizing with the APTES-glutaraldehyde method. We demonstrate validity of the method by measuring the diffusion of membrane proteins in yeast with single-particle tracking and of lipids in giant-unilamellar vesicles with fluorescence recovery after photobleaching. Importantly, the physical properties and shape of the fragile GUVs are not affected upon binding to APTES-glutaraldehyde coated glass. The APTES-glutaraldehyde is a generic method of immobilization that should work with any cell or synthetic system that has primary amines on the surface.
One-pot synthesis of graphene- cobalt hydroxide composite nanosheets (Co/G NSs) for electrocatalytic water oxidation
Authors: Mehmood Robab , Tariq Neelam , Zaheer Muhammad , Bibi Fozia , Iqbal Zafar
Published: September 2018

We report a one-pot method for the preparation of graphene-cobalt hydroxide nanosheets (Co/G NSs) and their use as an effective elelctrocatalyst for water oxidation. Mechanical exfoliation of graphite via sonication produced graphene sheets, which were stabilized by the surface adsorption of a cationic surfactant (CTAB). In a subsequent step, varying amount of a cobalt complex [sodium hexanitrocobaltate(III)] was added which selectively bound with the positively charged head of surfactant. In the last step, cobalt complex was reduced with sodium borohydride to obtain Co/G NSs catalyst. The catalyst showed lower overpotential (280 mV) as compared to benchmark catalysts and decent stability and turnover frequency (TOF: 0.089 s−1) for oxygen evolution reaction (OER).
G2Vec: Distributed gene representations for identification of cancer prognostic genes
Authors: Choi Jonghwan , Oh Ilhwan , Seo Sangmin , Ahn Jaegyoon
Published: September 2018

Identification of cancer prognostic genes is important in that it can lead to accurate outcome prediction and better therapeutic trials for cancer patients. Many computational approaches have been proposed to achieve this goal; however, there is room for improvement. Recent developments in deep learning techniques can aid in the identification of better prognostic genes and more accurate outcome prediction, but one of the main problems in the adoption of deep learning for this purpose is that data from cancer patients have too many dimensions, while the number of samples is relatively small. In this study, we propose a novel network-based deep learning method to identify prognostic gene signatures via distributed gene representations generated by G2Vec, which is a modified Word2Vec model originally used for natural language processing. We applied the proposed method to five cancer types including liver cancer and showed that G2Vec outperformed extant feature selection methods, especially for small number of samples. Moreover, biomarkers identified by G2Vec was useful to find significant prognostic gene modules associated with hepatocellular carcinoma.
Association of circulating calprotectin with lipid profile in axial spondyloarthritis
Authors: Genre Fernanda , Rueda-Gotor Javier , Remuzgo-Martínez Sara , Corrales Alfonso , Mijares Verónica , Expósito Rosa , Mata Cristina , Portilla Virginia , Blanco Ricardo , Hernández José Luis , Llorca Javier , Gualillo Oreste , López-Mejías Raquel , González-Gay Miguel A.
Published: September 2018

Calprotectin (CPT) is released during inflammation, also in the context of atherosclerosis. The link between CPT and the atherosclerotic process was evaluated in several diseases. However, studies in axial spondyloarthritis (axSpA), associated with a high incidence of subclinical atherosclerosis, are scarce. Therefore, we assessed the association of CPT with subclinical atherosclerosis and metabolic risk factors in axSpA. CPT serum levels were measured by enzyme-linked immunosorbent assay in 163 axSpA patients and 63 controls. Subclinical atherosclerosis was determined in patients by carotid ultrasonography (assessing the presence/absence of carotid plaques and carotid intima-media thickness [cIMT]). Data on inflammation, disease activity, lipid profile and treatment were collected to evaluate its relationship with CPT. axSpA patients evidenced lower CPT levels than controls. CPT showed no association with plaques or cIMT in axSpA. CPT and HDL-cholesterol negatively correlated, while a positive association of CPT with the atherogenic index was disclosed. Additionally, axSpA patients with C-reactive protein values at diagnosis higher than 3 mg/L displayed higher CPT levels. Our study shows no relationship between CPT and markers of subclinical atherosclerosis in axSpA. Nevertheless, it demonstrates an association of CPT with adverse lipid profiles and inflammatory biomarkers, which could further influence on the development of atherosclerosis.
Predictive accuracy of partial coherence interferometry and swept-source optical coherence tomography for intraocular lens power calculation
Authors: Whang Woong-Joo , Yoo Young-Sik , Kang Min-Ji , Joo Choun-Ki
Published: September 2018

The purpose of this study is to compare the predictive accuracy of intraocular lens (IOL) calculations made with partial coherence interferometry (PCI, IOLMaster, version 5) and swept-source optical coherence tomography (SS-OCT, Argos). Axial length (AL), mean keratometry value (K), and anterior chamber depth (ACD) were obtained using PCI and SS-OCT optical biometers. Intraocular lens (IOL) power calculations were made using the Barret-Universal II, Haigis, Hoffer Q, SRK/T, and T2 formulas and compared the predictive accuracy between biometers. In 153 eyes (153 patients), axial length measurements made with PCI (24.65 ± 2.35 mm) and SS-OCT (24.62 ± 2.29 mm) were significantly different (P < 0.001). Corneal power (P = 0.97) and anterior chamber depth (P = 0.51) were not significantly different between biometer. The mean absolute error was not significantly different between the five IOL power calculation formulas for either PCI or SS-OCT measurements. When AL was 24.5–26.0 mm, mean absolute error derived from SS-OCT was smaller than mean absolute error derived from PCI for all five IOL power calculation formulas (all P < 0.05). In conclusion, predictive accuracy of PCI and SS-OCT were nearly the same. However, in medium-long eyes, the predictive accuracy of SS-OCT for IOL calculations was higher.
Synchronization and causality across time scales in El Niño Southern Oscillation
Authors: Jajcay Nikola , Kravtsov Sergey , Sugihara George , Tsonis Anastasios A. , Paluš Milan
Published: September 2018

Statistical inference of causal interactions and synchronization between dynamical phenomena evolving on different temporal scales is of vital importance for better understanding and prediction of natural complex systems such as the Earth’s climate. This article introduces and applies information theory diagnostics to phase and amplitude time series of different oscillatory components of observed data that characterizes El Niño/Southern Oscillation. A suite of significant interactions between processes operating on different time scales is detected and shown to be important for emergence of extreme events. The mechanisms of these nonlinear interactions are further studied in conceptual low-order and state-of-the-art dynamical, as well as statistical climate models. Observed and simulated interactions exhibit substantial discrepancies, whose understanding may be the key to an improved prediction of ENSO. Moreover, the statistical framework applied here is suitable for inference of cross-scale interactions in human brain dynamics and other complex systems.
Strong two-dimensional plasmon in Li-intercalated hexagonal boron-nitride film with low damping
Authors: Lončarić Ivor , Rukelj Zoran , Silkin Vyacheslav M. , Despoja Vito
Published: September 2018

The field of plasmonics seeks to find materials with an intensive plasmon (large plasmon pole weight) with low Landau, phonon, and other losses (small decay width). In this paper, we propose a new class of materials that show exceptionally good plasmonic properties. These materials consist of van der Waals stacked “plasmon active” layers (atomically thin metallic layers) and “supporting” layers (atomically thin wide band gap insulating layers). One such material that can be experimentally realized—lithium intercalated hexagonal boron-nitride is studied in detail. We show that its 2D plasmon intensity is superior to the intensity of well-studied Dirac plasmon in heavy doped graphene, which is hard to achieve. We also propose a method for computationally very cheap, but accurate analysis of plasmon spectra in such materials, based on one band tight-binding approach and effective background dielectric function.
Carbon Nanomaterials in Analytical Separations
Authors: Hu Qin , Colón Luis A.
Published: September 2018

With the advent of nanotechnology, carbon nanomaterials (CNMs) have been investigated for a variety of applications, including their use in separation science. Of continuous interest is the use of CNMs as separation media for chromatographic applications in chemical analysis. In this chapter, we present an overview of the use of various CNMs as separation media that include carbon nanotubes (CNTs), fullerenes, graphene and graphene oxide (GO), as well as nanodiamonds (NDs). These CNMs provide good physical and chemical stability that allows for selective interactions with solutes to exert unique retention behaviors for analytical separations. In particular, we present how these nanomaterials have been incorporated as the stationary phases in gas chromatography (GC) and liquid chromatography (LC), as well as a pseudo-stationary phase in capillary electrophoresis (CE). Examples are presented to illustrate their use and the different type of interactions that contribute to specific separation modes (e.g., reversed phase, normal phase, and chiral separation modes). Initially, we provide a general view of the separation techniques used to study and/or purify CNMs, which indicates the interplay between separation science and nanotechnology.
Carbon Nanomaterials in Optical Detection
Authors: Wen Jia , Sun Shiguo
Published: September 2018

Owing to their unique optical, electronic, mechanical, and chemical properties, flexible chemical modification, large surface coverage and ready cellular uptake, various carbon nanomaterials such as carbon nanotubes (CNTs), graphene and its derivatives, carbon dots (CDs), graphene quantum dots, fullerenes, carbon nanohorns (CNHs) and carbon nano-onions (CNOs), have been widely explored for use in optical detection. Most of them are based on fluorescence changes. In this chapter, we will focus on carbon nanomaterials-based optical detection applications, mainly including fluorescence sensing and bio-imaging. Moreover, perspectives on future exploration of carbon nanomaterials for optical detection are also given.
Real-time characterization of uptake kinetics of glioblastomavs.astrocytes in 2D cell culture using microelectrode array
Authors: Rivera Jose F. , Sridharan Siddarth V. , Nolan James K. , Miloro Stephen A. , Alam Muhammad A. , Rickus Jenna L. , Janes David B.
Published: September 2018

Reconstructed analyte concentration profile using 1D microelectrode array enables characterization of uptake kineticsvs.analyte concentration at the cell surface.
A ratiometric photoelectrochemical immunosensor based on g-C3N4@TiO2 NTs amplified by signal antibodies–Co3O4 nanoparticle conjugates
Authors: Wu Qiong , Zhang Fengxia , Li Huijuan , Li Zhihua , Kang Qi , Shen Dazhong
Published: September 2018

Herein, we report a ratiometric photoelectrochemical (PEC) immunosensor coupled with secondary antibodies–Co3O4 nanoparticle conjugates (Ab2–Co3O4 NPs) for signal amplification.
Electrochemical aptasensors for zeatin detection based on MoS2 nanosheets and enzymatic signal amplification
Authors: Zhou Yunlei , Yin Huanshun , Wang Yue , Sui Chengji , Wang Minghui , Ai Shiyun
Published: September 2018

A simple and sensitive electrochemical aptasensor was constructed for zeatin detection, which is based on the block of the formation of Y-shape DNA due to the formation of the conjugate of zeatin and its aptamer.
Direct, uncorrected, molecule-free analysis of 236U from uranium-bearing particles with NAUTILUS: a new kind of mass spectrometer
Authors: Willingham D. , Groopman E. E. , Grabowski K. S. , Sangely L.
Published: September 2018

The Naval Ultra-Trace Isotope Laboratory's Universal Spectrometer (NAUTILUS) can measure 236U directly from uranium-bearing particles free from molecular isobaric interferences.
Unexpected stable phases of tungsten borides
Authors: Zhao Changming , Duan Yifeng , Gao Jie , Liu Wenjie , Dong Haiming , Dong Huafeng , Zhang Dekun , Oganov Artem R.
Published: September 2018

Superhard materials are generally synthesized under high pressure, which makes them expensive. We discovered new hard and superhard tungsten borides at low pressure and even at zero pressure with interesting properties.
Exchange equilibria of carboxylate-terminated ligands at PbS nanocrystal surfaces
Authors: Kessler Melody L. , Starr Hannah E. , Knauf Robin R. , Rountree Kelley J. , Dempsey Jillian L.
Published: September 2018

Exchange equilibria between carboxylic acids are quantified and ligand displacement mechanisms are probed on PbS nanocrystals synthesized via two different methods.
Activated barrier crossing dynamics of a Janus particle carrying cargo
Authors: Debnath Tanwi , Ghosh Pulak Kumar
Published: September 2018

We numerically study the escape kinetics of a self-propelled Janus particle, carrying a cargo, from a meta-stable state.
High-symmetry tubular Ta@B183−, Ta2@B18, and Ta2@B27+ as embryos of α-boronanotubes with a transition-metal wire coordinated inside
Authors: Li Hai-Ru , Liu Hui , Zhao Xiao-Yun , Pei Ling , Chen Na , Zan Wen-Yan , Lu Hai-Gang , Wang Yue-Kui , Mu Yue-Wen , Li Si-Dian
Published: September 2018

Tubular Ta@B183−, Ta2@B18, and Ta2@B27+ are predicted to be embryos of metalloboronanotubes with a metal wire inside.
Step-like band alignment and stacking-dependent band splitting in trilayer TMD heterostructures
Authors: Wang Hao , Wei Wei , Li Fengping , Huang Baibiao , Dai Ying
Published: September 2018

We propose a kind of trilayer TMD heterostructure with step-like band alignment, and the effects of interlayer coupling, strain and SOC are also discussed.
A new tetra-Zr(iv)-substituted polyoxotungstate aggregate
Authors: Li Hai-Lou , Wang Yue-Lin , Zhang Zhong , Yang Bai-Feng , Yang Guo-Yu
Published: September 2018

A new tetra-Zr(iv)-substituted tungstophosphate [H2N(CH3)2]6Na6H8{Zr2[SbP2W4(OH)2O21][α2-PW10O38]}2·50H2O has been made and structurally characterized. Its electrochemical and electrocatalytic properties have also been investigated.
Nitrogen substitution improves the mobility and stability of electron transport materials for inverted perovskite solar cells
Authors: Zhu Rui , Li Quan-Song , Li Ze-Sheng
Published: September 2018

The introduced nitrogen atoms into TDTP lead to higher electron mobility and improved stability and solubility via changing the packing mode.
Synthesis of α-amino ketones through aminations of umpoled enolates
Authors: Xia Xiaowen , Chen Bocheng , Zeng Xiaojun , Xu Bo
Published: September 2018

An efficient synthesis of α-amino ketones is developed using the umpolung strategy.
Synthesis and structure of a CDO zeolite precursor with a high Al content
Authors: Ahn Sang Hyun , Seo Seungwan , Lee Hwajun , Hong Suk Bong
Published: September 2018

A new high-silica (Si/Al = 8.7) CDO zeolite precursor has been synthesized using tetraethylammonium and tetramethylammonium ions in fluoride media.
Microwave-assisted delivery of an anticancer drug to cancer cells
Authors: Mazinani Sina Atrin , Stuart Jeffrey A. , Yan Hongbin
Published: September 2018

Exposure of MCF-7 breast and PC-3 prostate cancer cells to 10 W microwaves at 2.45 GHz increased their uptake of doxorubicin from media by almost 100%, concomitantly increasing cell death, while microwave exposure alone had no cellular toxicity.
The synthesis of HMF-based α-amino phosphonatesviaone-pot Kabachnik–Fields reaction
Authors: Fan Weigang , Queneau Yves , Popowycz Florence
Published: September 2018

A mild and efficient one-pot protocol for the synthesis of α-amino phosphonates directly from 5-HMF was described.
Targeting HMGA protein inhibits retinoblastoma cell proliferation
Authors: Balachandran Akilandeswari , Zambre Ajit , Kainth Jagjot Singh , Nagarajha Selvan Lakshmi Dhevi , Parameswaran Sowmya , Afrasiabi Zahra , Krishnakumar Subramanian , Kannan Raghuraman , Upendran Anandhi
Published: September 2018

A novel approach to target HMGA proteins in retinoblastoma using HMGA2 siRNA–nucleolin aptamer and HMGA aptamer–nucleolin antibody conjugates was developed.
Versiquinazolines L–Q, new polycyclic alkaloids from the marine-derived fungus Aspergillus versicolor
Authors: Cheng Zhongbin , Liu Dong , Cheng Wei , Proksch Peter , Lin Wenhan
Published: September 2018

Further chemical examination of a coral-associated fungus Aspergillus versicolor LZD-14-1 by the PHLC-DAD detection resulted in the isolation of six new polycyclic alkaloids, namely versiquinazolines L–Q (1–6).
Plasmon-engineered anti-replacement synthesis of naked Cu nanoclusters with ultrahigh electrocatalytic activity
Authors: Pan Shusheng , Zhang Xian , Lu Wei , Yu Siu Fung
Published: September 2018

Naked Cu nanoclusters synthesized by plasmon-engineered anti-replacement reaction between Au and Cu2+ ions.
Blue energy harvesting on nanostructured carbon materials
Authors: Liu Guohua , Chen Ting , Xu Jinliang , Wang Kaiying
Published: September 2018

This report summarizes experimental advances in, as well as the physical understanding of, the development of carbon-enabled nanogenerators for the water-energy nexus and illustrates their key features for electricity generation.
Valorization of lignin waste: high electrochemical capacitance of lignin-derived carbons in aqueous and ionic liquid electrolytes
Authors: Sangchoom Wantana , Walsh Darren A. , Mokaya Robert
Published: September 2018

Valorisation of waste lignin generates porous carbons with attractive properties as high-energy/high-power electrode materials for electric double layer capacitors (EDLCs), achieving an energy density of 25 W h kg−1at a power density of 500 W kg−1in ionic liquid electrolytes.
Simultaneous enhancement of piezoelectricity and temperature stability in (K,Na)NbO3-based lead-free piezoceramics by incorporating perovskite zirconates
Authors: Liu Qing , Zhang Yichi , Zhao Lei , Gao Jing , Zhou Zhen , Wang Ke , Zhang Xiaowen , Li Longtu , Li Jing-Feng
Published: September 2018

A new paradigm for the simultaneous enhancement of piezoelectric response and temperature stability by a compositionally modulated diffused phase transition.
Perceptual Encoding in Auditory Brainstem Responses: Effects of Stimulus Frequency
Authors: Tabachnick Alexandra R. , Toscano Joseph C.
Published: September 2018

Purpose

A central question about auditory perception concerns how acoustic information is represented at different stages of processing. The auditory brainstem response (ABR) provides a potentially useful index of the earliest stages of this process. However, it is unclear how basic acoustic characteristics (e.g., differences in tones spanning a wide range of frequencies) are indexed by ABR components. This study addresses this by investigating how ABR amplitude and latency track stimulus frequency for tones ranging from 250 to 8000 Hz.

Method

In a repeated-measures experimental design, listeners were presented with brief tones (250, 500, 1000, 2000, 4000, and 8000 Hz) in random order while electroencephalography was recorded. ABR latencies and amplitudes for Wave V (6–9 ms) and in the time window following the Wave V peak (labeled as
Wave VI
; 9–12 ms) were measured.

Results

Wave V latency decreased with increasing frequency, replicating previous work. In addition, Waves V and VI amplitudes tracked differences in tone frequency, with a nonlinear response from 250 to 8000 Hz and a clear log-linear response to tones from 500 to 8000 Hz.

Conclusions

Results demonstrate that the ABR provides a useful measure of early perceptual encoding for stimuli varying in frequency and that the tonotopic organization of the auditory system is preserved at this stage of processing for stimuli from 500 to 8000 Hz. Such a measure may serve as a useful clinical tool for evaluating a listener's ability to encode specific frequencies in sounds.

Supplemental Material

https://doi.org/10.23641/asha.6987422
Dual‐polarised patch antenna for in‐band full‐duplex applications
Authors: Goodbody C. , Karacolak T. , Tran N.
Published: September 2018

A probe‐fed patch antenna with 180° ring hybrid is proposed for in‐band full‐duplex applications. The proposed antenna consists of two substrate layers with the ground plane in between. A patch is printed on one substrate opposite the ground, and a ring hybrid is printed on a second substrate, which is designed to separate the receiving and transmitting signals, producing high isolation between the two. Simulated and fabricated prototype results show isolation of −58 dB covering the Industrial, Scientific and Medical (ISM) band of 2.4–2.5 GHz with a centre frequency of 2.45 GHz.
PVT compensated inverter‐based OTA for low‐voltage CT sigma‐delta modulators
Authors: de Aguirre P.C.C. , Susin A.A.
Published: September 2018

An inverter‐based operational transconductance amplifier (OTA) robust to process, voltage and temperature (PVT) variations is proposed in this Letter to enable the design of low‐voltage power‐efficient continuous‐time sigma‐delta modulators (CT‐SDMs). The proposed OTA significantly reduces the unity gain‐bandwidth variation across PVT corners while presenting a DC gain of 41.9 dB at nominal conditions when operated at 0.6 V. The effectiveness of the proposed circuit was verified in a 180 nm CMOS process by transistor‐level simulations including PVT variations and mismatch. Also, a 0.6 V third‐order CT‐SDM is designed to verify the robustness against voltage and temperature variations.
Process compensated bipolar junction transistor‐based CMOS temperature sensor with a ±1.5°C (3σ) batch‐to‐batch inaccuracy
Authors: Sun Dapeng , Zhang Tan‐Tan , Law Man‐Kay , Mak Pui‐In , Martins Rui Paulo
Published: September 2018

A bipolar junction transistor (BJT)‐based CMOS temperature sensor exploiting the piecewise BJT process spread compensation property of the base recombination current is proposed to reduce the process variations of the base–emitter voltage (Vbe). The weighted combinations of different on‐chip resistors are explored to minimise their associated process spread. Fabricated in standard 0.18‐μm CMOS, the chip prototype occupies an active area of 0.036 mm2 and draws 3 μA from a 1.2 V supply, with a measured maximum inter‐/intra‐die variation in Vbe of <1.5 mV from −40 to 125°C from two batches. Using the measured Vbe, ΔVbe and the first‐batch‐only calibration parameters, the chip prototype demonstrates an untrimmed batch‐to‐batch inaccuracy of ± 1.5°C (3σ) within the same temperature range (24 samples from 2 batches).
Fusion of infrared and visible images with Gaussian smoothness and joint bilateral filtering iteration decomposition
Authors: Xing Changda , Wang Zhisheng , Meng Fanliang , Dong Chong
Published: September 2018

Edge‐preserving filters have been applied to Multi‐Scale Decomposition (MSD) for fusion of infrared and visible images. Traditional edge‐preserving MSDs may hardly make satisfied structural separation from details to cause fusion performance degradation. To suppress this challenge, the authors propose a novel fusion of infrared and visible images with Gaussian smoothness and joint bilateral filtering iteration decomposition (MSD‐Iteration). This method consists of three steps. First, source images are decomposed by the Gaussian smoothness and joint bilateral filtering iteration. The implementation includes the fine‐scale detail removal with Gaussian filtering, edge and structure extraction with joint bilateral filtering iteration, and detail obtaining at multi‐scales. The decomposition has edge‐preserving and scale‐aware properties to improve detail acquisition. Second, rules are designed to conduct the layer combination. For the rule of base layers, saliency maps are constructed by Laplacian and Gaussian low‐pass filters to calculate initial weight maps. A guided filter is further applied to determine final weight maps for the combination. Meanwhile, they use the regional average energy weighting to obtain decision maps at multi‐scales by constructing intensity deviation to combine detail layers. Third, they implement the reconstruction with the combined layers. Sufficient experiments are presented to evaluate MSD‐Iteration, and experimental results validate the superiority of the authors’ method.
Autoencoder‐based abnormal activity detection using parallelepiped spatio‐temporal region
Authors: George Michael , Jose Babita Roslind , Mathew Jimson , Kokare Pranjali
Published: September 2018

The spread of surveillance cameras has necessitated the monitoring of large quantities of surveillance video feeds. A manual monitoring system is near impossible due to the large man‐hour requirements. Recently, automatic abnormal activity detection has been an area of interest among researchers. A spatio‐temporal feature, histogram of optical flow orientation and magnitude (HOFM), has produced impressive ability in detecting abnormal activities. The authors propose a novel non‐uniform spatio‐temporal region resembling parallelepipeds, from which they extract the HOFM features. Autoencoders can be configured to detect abnormal patterns. The authors have used these abilities of the autoencoders to detect abnormalities in the HOFM features extracted from their novel spatio‐temporal regions of the video feeds. The autoencoders are trained on the HOFM features of the videos containing no abnormalities. The autoencoders are then fed with the HOFM features of the videos to be tested for abnormal activities, and these are detected based on the abilities of the autoencoders to reconstruct these features. The proposed method is tested on the standard abnormality detection datasets: UCSD Ped1, UCSD Ped2, Subway Entrance, Subway Exit, and UMN.
e‐Textile embroidered wearable near‐field communication RFID antennas
Authors: Jiang Yutong , Xu Lulu , Pan Kewen , Leng Ting , Li Yi , Danoon Laith , Hu Zhirun
Published: September 2018

Wearable e‐textile near‐field communication (NFC) radio‐frequency identification (RFID) antennas fully integrated with garments using embroidery techniques, which enables everyday clothing to become connective to wireless communication systems, is presented. The e‐textile wearable antennas have been designed through full electromagnetic wave simulation based on the electrical properties of conductive threads and textile substrates at the high frequency band, allocated for NFC wireless communications. The e‐textile wearable NFC antenna performance under mechanical bending as well as human body effects have been experimentally studied and evaluated; the antennas can operate under significantly bending angle and body effects attributed to its broad operating bandwidth. This is highly desirable and distinguished to conventional NFC antennas; the proposed e‐textile wearable NFC antennas can be placed almost any place on clothes and still capable to communicate at the desired operating frequency of 13.56 MHz. The maximum read range of the e‐textile wearable NFC tags is measured to be around 5.6 cm, being compatible to typical commercially available metallic NFC tags. The e‐textile wearable NFC tags can lead to numerous potential applications such as information exchange, personal security, health monitoring and Internet of Things.
Enhancing discharged energy density and suppressing dielectric loss of poly(vinylidene fluoride‐ter‐trifluoroethylene‐ter‐chlorofluoroethylene) by a sandwiched structure
Authors: Zhu Yingke , Jiang Pingkai , Huang Xingyi
Published: September 2018

Polymer dielectrics with high energy density and low dielectric loss are highly desired due to the rapid development of electric devices. Among known polymers, poly(vinylidene fluoride‐ter‐trifluoroethylene‐ter‐chlorofluoroethylene) P(VDF‐TrFE‐CFE) is one of the promising materials for energy storage capacitor applications because of its high dielectric constant. Nevertheless, it suffers from high dielectric loss especially at the high electric field, which suppresses its breakdown strength and energy storage density. Herein, sandwiched structure dielectric films were fabricated by employing polymethyl methacrylate (PMMA) as the outer layer and P(VDF‐TrFE‐CFE) as the central layer. By modulating the thickness of the central layer, an enhanced discharged energy density of 7.03 J/cm3 is achieved at a high electric field of 480 MV/m, which is 132% more than that of P(VDF‐TrFE‐CFE) at its maximum electric field 300 MV/m. Meanwhile, this sandwiched structure film also retains a high discharge efficiency of 78% at 480 MV/m, which is never been seen in polyvinylidene fluoride‐based polymers. Results show that PMMA acts as charge barrier and simultaneously enhance the breakdown strength and suppress the dielectric loss of P(VDF‐TrFE‐CFE).
Dual‐frequency induction heating for gear hardening: converter, resonant circuit, and FEM modelling
Authors: Kierepka Kamil , Legutko Piotr , Zimoch Piotr , Kasprzak Marcin
Published: September 2018

In order to achieve required mechanical properties of hardened elements, such as gear wheels, dual‐frequency induction heating may be used. Dual‐frequency allows heating only the outline of the gear, due to mixed penetration depth of the subject frequencies. This method of hardening requires the process to be very short as heat may spread by means of conduction. This study presents a 3 kW prototype inverter and its control scheme is used to generate dual‐frequency output current. The overall efficiency of the inverter is 96%. An analysis of the output resonant circuit is made to find the resonant frequencies. Finally, circuit and finite element method (FEM) simulations are coupled to analyse the effect of dual‐frequency current on the magnetic field, current density, and energy density on the surface of a gear wheel.
Dramatic change in the boundary layer in the symbiotic recurrent nova T Coronae Borealis
Authors: Luna G. J. M. , Mukai K. , Sokoloski J. L. , Nelson T. , Kuin P. , Segreto A. , Cusumano G. , Jaque Arancibia M. , Nuñez N. E.
Published: September 2018

A sudden increase in the rate at which material reaches the most internal part of an accretion disk, i.e., the boundary layer, can change its structure dramatically. We have witnessed such a change for the first time in the symbiotic recurrent nova T CrB. Our analysis of XMM-Newton, Swift Burst Alert Telescope (BAT)/X-Ray Telescope (XRT)/UltraViolet Optical Telescope (UVOT), and the American Association of Variable Stars Observers (AAVSO) V- and B-band data indicates that during an optical brightening event that started in early 2014 (ΔV ≈ 1.5) the following occurred: (i) the hard X-ray emission as seen with BAT almost vanished; (ii) the XRT X-ray flux decreased significantly, while the optical flux remained high; (iii) the UV flux increased by at least a factor of 40 over the quiescent value; and (iv) the X-ray spectrum became much softer and a bright, new blackbody-like component appeared. We suggest that the optical brightening event, which could be a similar event to that observed about 8 years before the most recent thermonuclear outburst in 1946, is due to a disk instability.
Incidence de l’ombrage sur les caractères phénotypiques du cacaoyer en zone de transition forêt-savane au centre de la Côte d’Ivoire
Authors: Kouadio Venance-Pâques Gniayou , Vroh Bi Tra Aimé , Kpangui Kouassi Bruno , Kossonou Affia Sonmia Francia , Adou Yao Constant Yves
Published: September 2018

Le centre de la Côte d’Ivoire abrite divers systèmes agroforestiers à base de cacaoyers, qui se distinguent selon la densité de l’ombrage des arbres associés : système simple (canopée ouverte et espèces exotiques – bananier et avocatier), mixte (canopée ouverte, peu d’espèces locales) ou complexe (canopée fermée et nombreuses espèces locales). La floraison et la fructification de 220 cacaoyers ont été suivies dans 44 parcelles de 625 m2, réparties dans les trois systèmes. Le nombre de coussinets floraux, le nombre de cabosses mûres par cacaoyer, ainsi que la masse et la qualité des cabosses sont significativement plus grands dans le système simple que dans le système complexe. Bien que le nombre moyen de fèves par cabosse ne varie pas significativement, la masse moyenne des fèves est plus grande dans le système simple que dans le système complexe. Le système simple serait donc plus productif ; cependant, la prise en compte de la valeur des services rendus par les espèces associées devra être prise en compte pour préciser la durabilité.
Heterogeneous elastic plates with in-plane modulation of the target curvature and applications to thin gel sheets
Authors: Agostiniani Virginia , Lucantonio Alessandro , Lučić Danka
Published: September 2018

We rigorously derive a Kirchhoff plate theory, via Γ-convergence, from a three-dimensional model that describes the finite elasticity of an elastically heterogeneous, thin sheet. The heterogeneity in the elastic properties of the material results in a spontaneous strain that depends on both the thickness and the plane variables x′. At the same time, the spontaneous strain is h-close to the identity, where h is the small parameter quantifying the thickness. The 2D Kirchhoff limiting model is constrained to the set of isometric immersions of the mid-plane of the plate into ℝ3, with a corresponding energy that penalizes deviations of the curvature tensor associated with a deformation from an x′-dependent target curvature tensor. A discussion on the 2D minimizers is provided in the case where the target curvature tensor is piecewise constant. Finally, we apply the derived plate theory to the modeling of swelling-induced shape changes in heterogeneous thin gel sheets.
Dynamic failure of viscoplastic structures under ASB and micro-voiding
Authors: Lois Dorothy Hannah , Longere Patrice
Published: September 2018

Adiabatic shear bands are known to cause premature structural failure in high strength metals and alloys. The observation of adiabatic shear bands inside partially fractured specimens evidences the presence of micro-voids as the precursor of the ultimate failure. An enriched model containing the effects of adiabatic shear banding and micro-voiding mechanisms was developed and it is here taken through a calibration procedure. The aim of the present work is to evaluate the performances of the enriched model considering an initial-boundary value problem. To that purpose, the model has been implemented as user material in the engineering finite element computation code LS-DYNA. Numerical simulation of the dynamic shearing of hat shaped structures is conducted and the interest of accounting for the pre-failure stage consisting of micro-voiding in the ASB wake is emphasized.
An Accurate SPH Scheme for Dynamic Fragmentation modelling
Authors: Collé Anthony , Limido Jérôme , Vila Jean-Paul
Published: September 2018

We focus on the use of a meshless numerical method called Smooth Particle Hydrodynamics (SPH), to solve fragmentation issues as Hyper Velocity Impact (HVI) cases. Firstly applied to fluid flow simulations, this method can be extended to the solid dynamics framework. However it suffers from a lack of accuracy when evaluating state variables as the pressure field. And such inaccuracy generally generates non-physical processes (as numerical fragmentation). In the hydrodynamic context, SPH-ALE methods based on Riemann solvers significantly improve this evaluation, but increase the scheme complexity and low-Mach issues are difficult to prevent. We propose an alternative scheme called γ-SPH-ALE, firstly implemented to solve multi-regime barotropic flows, and secondly extended to solid dynamic cases. It relies on the combination of the SPH-ALE formalism and a finite volume stabilizing low-Mach scheme. Its characteristics are detailed and evaluated through a nonlinear stability analysis, highlighting CFL-like conditions on the scheme parameters. Finally, its implementation on several test cases reveals that the proposed scheme actually increases both stability and accuracy, in reduced computation time, with respect to classical solvers.
Hyperelastic modelling of yarn structures for dynamic applications
Authors: del Sorbo Pietro , Girardot Jeremie , Dau Frederic , Iordanoff Ivan
Published: September 2018

Dry fabrics comprised of high performance polymeric fibers have been widely used as protection layers in structures submitted to high velocity impacts (HVI). Their outstanding impact energy dissipation ability combined with an high strength-to-weight ratio make them a preferable choice in different applications such as bullet vests or blade containment systems over standard materials. Among the different approaches adopted to study these structures numerical methods assume a central role.

Thanks to their reduced costs and the related possibility of evaluating the effects of single phenomena, they are often used to predict the structure ballistic limits or to study the physical events which occur during the penetration.

Among the different strategies adopted to model a fabric, mesoscopic models have been largely adopted by different authors. These models assume the yarns as a continuum body while the fabric geometry is explicitly described. Nowadays yarn material models are universally assumed to be linear elastic and orthotropic. This modelling approach mostly focuses on the longitudinal behaviour of the yarn, however fiber-scale analyses and experimental results shows the importance of three-dimensional stress state on the ballistic limit.

In order to obtain a three-dimensional description of the yarn strain state during the impact, a novel hyperelastic model for yarn structures here is developed. In a first step, fiber-level preliminary analyses have been performed to obtain the effective behaviour of these structure under the projectile collision. In the second step, the hyperelastic model has been implemented and identified thanks to microscopic elementary tests. Finally, a continuum model of the yarn have been performed. First results show the relevance of the hyperelastic model compared to the fiber-level observation and enhance the limit of the classical linear elastic material model.
Material Tests and Mesoscale Computer Model for Ballistic Impact on Carbon Fiber Composite
Authors: Chocron Sidney , Carpenter Alexander , Bigger Rory , Scott Nikki , Warren Kyle , Bayraktar Harun
Published: September 2018

Two-dimensional (unidirectional) and 3-D woven carbon fiber reinforced plastic (CFRP) panels were produced by Albany Engineered Composites. Coupons were machined from the laminates for various mechanical tests in tension, torsion, and delamination. A batch of neat resin was also produced and the mechanical properties of the resin were determined. Some of the mechanical tests were performed at medium and high strain rates. The panels were tested under ballistic impact while recording the back face deflection with a stereo pair of high-speed cameras to perform digital image correlation. Additionally, an ultra-high-speed camera provided a better resolution of the initial (50 ms) pyramid that forms after impact. The mechanical tests were used to determine the material properties of the constituents as well as the strength of the interface between matrix and fibers. The properties were incorporated in material models in LS-DYNA to perform simulations of the mechanical tests as well as the ballistic experiments. The ballistic limits, residual velocities, and deflection histories served as a validation of the model and were predicted with good accuracy for two thicknesses of the two-dimensional composite and one of the 3-D composite.
Study of the ballistic behaviour of UHMWPE composite material: experimental characterization and numerical simulation
Authors: Abdulhamid Hakim , Deconinck Paul , Héreil Pierre-Louis , Mespoulet Jérôme
Published: September 2018

This paper presents a comprehensive mechanical study of UHMWPE (Ultra High Molecular Weight Polyethylene) composite material under dynamic loadings. The aim of the study is to provide reliable experimental data for building and validate the composite material model under impact. Four types of characterization tests have been conducted: dynamic in-plane tension, out-of-plane compression, shear tests and plate impact tests. Then, several impacts of spherical projectiles have been performed. Regarding the numerical simulation, an intermediate scale multi-layered model (between meso and macro scale levels) is proposed. The material response is modelled with a 3d elastic orthotropic law coupled with fibre damage model. The modelling choice is governed by a balance between reliability and computing cost. Material dynamic response is unconventional [1, 2]: it shows large deformation before failure, very low shear modulus and peeling strength. Numerical simulation has been used both in the design and the analysis of tests. Many mechanical properties have been measured: elastic moduli, failure strength and EOS of the material. The numerical model is able to reproduce the main behaviours observed in the experiment. The study has highlighted the influence of temperature and fibre slipping in the impact response of the material.
On the Rate-dependent Plasticity Modelling of Unidirectional Fibre-reinforced Polymeric Matrix Composites
Authors: Erice Borja , Thomson Daniel , Ponnusami Sathiskumar A. , Pathan Mehtab V. , Petrinic Nik
Published: September 2018

Three different approaches to plasticity are investigated to model the experimentally-observed non-linear behaviour of unidirectional fibre-reinforced polymeric matrix materials. The first and simplest approach consists on assuming independent one-dimensional rate-dependent plasticity on in-plane (12) and through-thickness longitudinal (13) shear components of the Cauchy stress tensor. The second, employs a 3D extension of the plane stress Hill’48 anisotropic plastic surface. The third and the last is formulated as a quadratic yield function inspired by Puck’s fracture initiation criterion. It searches for a plastic localisation plane in which a certain combination of normal and shear stresses is maximum. Numerical simulations are conducted to analyse the off-axis compression behaviour of carbon fibre reinforced epoxy composite under varying loading rates. The afore-mentioned three different approaches are explored with an aim to predict the experimentally-observed non-linear response of such composites. The model parameters are determined using a deterministic inverse modelling strategy employing an iterative domain reduction optimisation technique. As far as the experiments are concerned, the quasi-static and medium rate tests were carried out in universal testing machines, while the experiments at high rate were conducted in a Split Hopkinson Pressure Bar system. The effectiveness in terms of accuracy and robustness of the three approaches are discussed.
Energy absorbing properties of a steel profile made of dual phase steel
Authors: Moćko Wojciech , Brodecki Adam
Published: September 2018

Three point bending tests were carried out using a drop tower testing machine. Profile were made of 2 mm dual phase steel. Material was characterized at wide range of strain rates to calibrate Rusinek-Klepaczko constitutive model. Finally, experimental results were compared with numerical predictions obtained using finite element method.