bluuebunny/crossref_metadata_2025 huggingface dataset:
Activin A regulates the epidermal growth factor receptor promoter by activating the PI3K/SP1 pathway in oral squamous cell carcinoma cells
Authors: Tsai Chi-Neu , Tsai Chia-Lung , Yi Jui-Shan , Kao Huang-Kai , Huang Yenlin , Wang Chun-I , Lee Yun-Shien , Chang Kai-Ping
Published: March 2019

Epidermal growth factor receptor (EGFR) and activin A are both overexpressed in oral cavity squamous cell carcinoma (OSCC). We evaluated their clinical correlation and activin A-mediated EGFR regulation in this study. Overexpression of both transcripts/proteins indicated a poorer prognosis in OSCC patients. Knockdown of endogenous INHBA repressed the expression of EGFR and inhibited activin A-mediated canonical Smads, noncanonical phosphorylation of AKT (ser473) (p-AKT ser473) and SP1. Inhibition of PI3K signaling via its inhibitor attenuated p-AKT ser473 and in turn reduced SP1 and EGFR expression in the presence of recombinant activin A (rActivin A) in OSCC cells, as revealed via a luciferase assay and western blotting. However, canonical Smad signaling repressed the EGFR promoter, as revealed by a luciferase assay. The transcription factor SP1, its coactivator CBP/p300, and Smad proteins were recruited to the EGFR proximal promoter following rActivin A treatment, as revealed by chromatin immunoprecipitation (ChIP). Smad2/3/4 dramatically outcompeted SP1 binding to the EGFR proximal promoter following mithramycin A treatment. Activin A activates the PI3K and Smad pathways to compete for binding to overlapping SP1 consensus sequences on the EGFR proximal promoter. Nevertheless, canonical p-Smad2 was largely repressed in OSCC tumor tissues, suggesting that the activin A-mediated noncanonical pathway is essential for the carcinogenesis of OSCC.
Effect of Mechanical Stretch on the DNCB-induced Proinflammatory Cytokine Secretion in Human Keratinocytes
Authors: Oh Seunghee , Chung Hyewon , Chang Sooho , Lee Su-Hyon , Seok Seung Hyeok , Lee Hyungsuk
Published: March 2019

Skin is exposed to various physico-chemical cues. Keratinocytes, a major component of the skin epidermis, directly interact with the surrounding extracellular matrix, and thus, biochemical and biophysical stimulations from the matrix regulate the function of keratinocytes. Although it was reported that inflammatory responses of skin were altered by an applied mechanical force, understanding how the keratinocytes sense the mechanical stimuli and regulate a cytokine secretion remains unclear. Here, we designed a device that is able to apply chemo-mechanical cues to keratinocytes and assess their proinflammatory cytokine IL-6 production. We showed that when chemical stimuli were applied with mechanical stimuli simultaneously, the IL-6 production markedly increased compared to that observed with a single stimulus. Quantitative structural analysis of cellular components revealed that the applied mechanical stretch transformed the cell morphology into an elongated shape, increased the cell size, and dictated the distribution of focal adhesion complex. Our results suggest that the mechanical cue-mediated modulation of focal adhesion proteins and actin cytoskeleton translates into intracellular signaling associated with the IL-6 production particularly in skin sensitization. Our study can be applied to understand proinflammatory responses of skin under altered biophysical environments of the skin.
Mass production of poly(ethylene glycol) monooleate-modified core-shell structured upconversion nanoparticles for bio-imaging and photodynamic therapy
Authors: Zhang Xingyuan , Guo Zhao , Zhang Xiao , Gong Linji , Dong Xinghua , Fu Yanyan , Wang Qing , Gu Zhanjun
Published: March 2019

Developing robust and high-efficient synthesis approaches has significant importance for the expanded applications of upconversion nanoparticles (UCNPs). Here, we report a high-throughput synthesis strategy to fabricate water-dispersible core-shell structured UCNPs. Firstly, we successfully obtain more than 10 grams core UCNPs with high quality from one-pot reaction using liquid rare-earth precursors. Afterwards, different core-shell structured UCNPs are fabricated by successive layer-by-layer strategy to get enhanced fluorescence property. Finally, the hydrophobic UCNPs are modified with poly(ethylene glycol) monooleate (PEG-OA) though a novel physical grinding method. On the basis of mass-production, we use the as-prepared PEG-UCNPs to construct an 808-nm stimuli photodynamic therapy agent, and apply them in cancer therapy and bio-imaging.
Context-dependent activity of A domains in the tyrocidine synthetase
Authors: Degen Anna , Mayerthaler Florian , Mootz Henning D. , Di Ventura Barbara
Published: March 2019

Non-ribosomal peptide synthetases (NRPSs) are large, modular enzymes that produce bioactive peptides of tremendous structural and chemical diversity, due to the incorporation, alongside the canonical 20 amino acids, of non-proteinogenic amino acids, fatty acids, sugars and heterocyclic rings. For linear NRPSs, the size and composition of the peptide product is dictated by the number, order and specificity of the individual modules, each made of several domains. Given the size and complexity of NRPSs, most in vitro studies have focused on individual domains, di-domains or single modules extracted from the full-length proteins. However, intermodular interactions could play a critical role and regulate the activity of the domains and modules in unpredictable ways. Here we investigate in vitro substrate activation by three A domains of the tyrocidine synthetase TycC enzyme, systematically comparing their activity when alone (with the respective PCP domain), in pairs (di-modular constructs) or all together (tri-modular construct). Furthermore, we study the impact of mutations in the A or PCP domains in these various constructs. Our results suggest that substrate adenylation and effects of mutations largely depend on the context in which the domains/modules are. Therefore, generalizing properties observed for domains or modules in isolation should be done with caution.
Parasite detection in the ornamental fish trade using environmental DNA
Authors: Trujillo-González A. , Edmunds R. C. , Becker J. A. , Hutson K. S.
Published: March 2019

Effective border control relies on stringent biosecurity protocols to detect and prevent introductions of exotic pests and diseases. Detection of pathogens and parasites in the live ornamental fish trade using environmental DNA (eDNA) techniques has the potential to improve current biosecurity practices. We examined water samples from 11 target consignments (cyprinids susceptible to Dactylogyrus spp. infections) and seven non-target fish consignments (non-cyprinids, not susceptible to Dactylogyrus spp. infections) imported from Southeast Asia to Australia for the presence of eDNA from five Dactylogyrus species (Monogenea: Dactylogyridae). A four-step predictive framework was used to predict putative positive and putative negative detections from quantitative PCR assays. Both target and non-target consignments were positive for Dactylogyrus spp. eDNA as confirmed by Sanger sequencing. Positive detections for Dactylogyrus spp. eDNA in non-target fish consignments demonstrates the possibility of source water contamination, limiting the applicability of eDNA screening methods at border control. This study suggests that screening for parasite eDNA within ornamental fish consignments should be tested during pre-export quarantine periods to avoid false positive detections at border control. Lastly, the proposed predictive framework has a broad utility for minimizing false positive and false negative eDNA detections of aquatic organisms.
Theoretical analysis on thermodynamic stability of chignolin
Authors: Sumi Tomonari , Koga Kenichiro
Published: March 2019

Understanding the dominant factor in thermodynamic stability of proteins remains an open challenge. Kauzmann’s hydrophobic interaction hypothesis, which considers hydrophobic interactions between nonpolar groups as the dominant factor, has been widely accepted for about sixty years and attracted many scientists. The hypothesis, however, has not been verified or disproved because it is difficult, both theoretically and experimentally, to quantify the solvent effects on the free energy change in protein folding. Here, we developed a computational method for extracting the dominant factor behind thermodynamic stability of proteins and applied it to a small, designed protein, chignolin. The resulting free energy profile quantitatively agreed with the molecular dynamics simulations. Decomposition of the free energy profile indicated that intramolecular interactions predominantly stabilized collapsed conformations, whereas solvent-induced interactions, including hydrophobic ones, destabilized them. These results obtained for chignolin were consistent with the site-directed mutagenesis and calorimetry experiments for globular proteins with hydrophobic interior cores.
GluR2 endocytosis-dependent protein degradation in the amygdala mediates memory updating
Authors: Ferrara Nicole C. , Jarome Timothy J. , Cullen Patrick K. , Orsi Sabrina A. , Kwapis Janine L. , Trask Sydney , Pullins Shane E. , Helmstetter Fred J.
Published: March 2019

Associations learned during Pavlovian fear conditioning are rapidly acquired and long lasting, providing an ideal model for studying long-term memory formation, storage, and retrieval. During retrieval, these memories can “destabilize” and become labile, allowing a transient “reconsolidation” window during which the memory can be updated, suggesting that reconsolidation could be an attractive target for the modification of memories related to past traumatic experiences. This memory destabilization process is regulated by protein degradation and GluR2-endocytosis in the amygdala. However, it is currently unknown if retrieval-dependent GluR2-endocytosis in the amygdala is critical for incorporation of new information into the memory trace. We examined whether the addition of new information during memory retrieval required GluR2-endocytosis to modify the original memory. The presentation of two foot shocks of weaker intensity during retrieval resulted in GluR2 endocytosis-dependent increase in fear responding on a later test, suggesting modification of the original memory. This increase in fear expression was associated with increased protein degradation and zif268 expression in the same population of cells in the amygdala, indicating increased destabilization processes and cellular activity, and both were lost following blockade of GluR2-endocytosis. These data suggest that the endocytosis of GluR2-containing AMPA receptors in the amygdala regulates retrieval-induced strengthening of memories for traumatic events by modulating cellular destabilization and activity.
NeuroPIpred: a tool to predict, design and scan insect neuropeptides
Authors: Agrawal Piyush , Kumar Sumit , Singh Archana , Raghava Gajendra P. S. , Singh Indrakant K.
Published: March 2019

Insect neuropeptides and their associated receptors have been one of the potential targets for the pest control. The present study describes in silico models developed using natural and modified insect neuropeptides for predicting and designing new neuropeptides. Amino acid composition analysis revealed the preference of residues C, D, E, F, G, N, S, and Y in insect neuropeptides The positional residue preference analysis show that in natural neuropeptides residues like A, N, F, D, P, S, and I are preferred at N terminus and residues like L, R, P, F, N, and G are preferred at C terminus. Prediction models were developed using input features like amino acid and dipeptide composition, binary profiles and implementing different machine learning techniques. Dipeptide composition based SVM model performed best among all the models. In case of NeuroPIpred_DS1, model achieved an accuracy of 86.50% accuracy and 0.73 MCC on training dataset and 83.71% accuracy and 0.67 MCC on validation dataset whereas in case of NeuroPIpred_DS2, model achieved 97.47% accuracy and 0.95 MCC on training dataset and 97.93% accuracy and 0.96 MCC on validation dataset. In order to assist researchers, we created standalone and user friendly web server NeuroPIpred, available at (https://webs.iiitd.edu.in/raghava/neuropipred.)
Possibility of a new order parameter driven by multipolar moment and Fermi surface evolution in CeGe
Authors: Singh Karan , Mukherjee K.
Published: March 2019

Polycrystalline CeGe is investigated by means of DC and AC susceptibility, non-linear DC susceptibility, electrical transport and heat capacity measurements in the low temperature regime. This compound shows two peaks at low magnetic field around TI ~ 10.7 and TII ~ 7.3 K due to antiferromagnetic ordering and subsequent spin rearrangement respectively. Investigation of non-linear DC susceptibility reveals a presence of higher order magnetization which results in the development of a new order parameter around TI. This leads to a lowering of symmetry of the magnetic state. The order parameter increases with decreasing temperature and stabilizes around TII. Consequently, the symmetry of the magnetic state is preserved below this transition. Heat capacity and resistivity results indicate the presence of a gap opening around TI on portion of Fermi surface, due to evolution of the Fermi surface. Magnetoresistance behavior and violation of Kohler’s rule suggest that the evolution of Fermi surface changes the symmetry of magnetic state. The observation of new order parameter (which is of second order) is also confirmed from the Landau free energy theory.
A murine model to study vasoreactivity and intravascular flow in lung isograft microvessels
Authors: Regelin Nora , Heyder Susanne , Laschke Matthias W. , Hadizamani Yalda , Borgmann Michèle , Moehrlen Ueli , Schramm René , Bals Robert , Menger Michael D. , Hamacher Jürg
Published: March 2019

Intravital microscopy of orthotopic lung tissue is technically demanding, especially for repeated investigations. Therefore, we have established a novel approach, which allows non-invasive repetitive in vivo microscopy of ectopic lung tissue in dorsal skinfold chambers. Syngeneic subpleural peripheral lung tissue and autologous endometrium (control) were transplanted onto the striated muscle within dorsal skinfold chambers of C57BL/6 mice. Grafts were analysed by intravital fluorescence microscopy over 14 days. Angiogenesis occurred in the grafts on day 3, as indicated by sinusoidal microvessels on the grafts’ edges with very slow blood flow, perifocal oedema, and haemorrhage. By day 10, lung transplants were completely revascularized, exhibited a dense network of microvessels with irregular diameters, chaotic angioarchitecture, and high blood flow. Compared to lung tissue, endometrial grafts contained a structured, glomerulus-like vessel architecture with lower blood flow. Despite missing ventilation, hypoxic vasoconstriction of the lung tissue arterioles occurred. In contrast, endometrium tissue arterioles dilated during hypoxia and constricted in hyperoxia. This demonstrates that ectopic lung grafts keep their ability for organ-specific hypoxic vasoconstriction. These findings indicate that our approach is suitable for repetitive in vivo pulmonary microcirculation analyses. The high blood flow and hypoxia-induced vasoconstriction in lung grafts suggest a physiological intrinsic vasoregulation independent of the recipient tissue.
Exponential consensus ranking improves the outcome in docking and receptor ensemble docking
Authors: Palacio-Rodríguez Karen , Lans Isaias , Cavasotto Claudio N. , Cossio Pilar
Published: March 2019

Consensus-scoring methods are commonly used with molecular docking in virtual screening campaigns to filter potential ligands for a protein target. Traditional consensus methods combine results from different docking programs by averaging the score or rank of each molecule obtained from individual programs. Unfortunately, these methods fail if one of the docking programs has poor performance, which is likely to occur due to training-set dependencies and scoring-function parameterization. In this work, we introduce a novel consensus method that overcomes these limitations. We combine the results from individual docking programs using a sum of exponential distributions as a function of the molecule rank for each program. We test the method over several benchmark systems using individual and ensembles of target structures from diverse protein families with challenging decoy/ligand datasets. The results demonstrate that the novel method outperforms the best traditional consensus strategies over a wide range of systems. Moreover, because the novel method is based on the rank rather than the score, it is independent of the score units, scales and offsets, which can hinder the combination of results from different structures or programs. Our method is simple and robust, providing a theoretical basis not only for molecular docking but also for any consensus strategy in general.
Characteristics and homogeneity of N6-methylation in human genomes
Authors: Pacini Clare E. , Bradshaw Charles R. , Garrett Nigel J. , Koziol Magdalena J.
Published: March 2019

A novel DNA modification, N-6 methylated deoxyadenosine (m6dA), has recently been discovered in eukaryotic genomes. Despite its low abundance in eukaryotes, m6dA is implicated in human diseases such as cancer. It is therefore important to precisely identify and characterize m6dA in the human genome. Here, we identify m6dA sites at nucleotide level, in different human cells, genome wide. We compare m6dA features between distinct human cells and identify m6dA characteristics in human genomes. Our data demonstrates for the first time that despite low m6dA abundance, the m6dA mark does often occur consistently at the same genomic location within a given human cell type, demonstrating m6dA homogeneity. We further show, for the first time, higher levels of m6dA homogeneity within one chromosome. Most m6dA are found on a single chromosome from a diploid sample, suggesting inheritance. Our transcriptome analysis not only indicates that human genes with m6dA are associated with higher RNA transcript levels but identifies allele-specific gene transcripts showing haplotype-specific m6dA methylation, which are implicated in different biological functions. Our analyses demonstrate the precision and consistency by which the m6dA mark occurs within the human genome, suggesting that m6dA marks are precisely inherited in humans.
Pancreatic stone protein/regenerating protein is a potential biomarker for endoplasmic reticulum stress in beta cells
Authors: Stone Stephen , Abreu Damien , Mahadevan Jana , Asada Rie , Kries Kelly , Graf Rolf , Marshall Bess A. , Hershey Tamara , Urano Fumihiko
Published: March 2019

Endoplasmic reticulum (ER) stress in beta cells is an important pathogenic component of both type 1 and type 2 diabetes mellitus, as well as genetic forms of diabetes, especially Wolfram syndrome. However, there are currently no convenient ways to assess ER stress in beta cells, raising the need for circulating ER stress markers indicative of beta cell health. Here we show that pancreatic stone protein/regenerating protein (PSP/reg) is a potential biomarker for ER stressed beta cells. PSP/reg levels are elevated in cell culture and mouse models of Wolfram syndrome, a prototype of ER stress-induced diabetes. Moreover, PSP/reg expression is induced by the canonical chemical inducers of ER stress, tunicamycin and thapsigargin. Circulating PSP/reg levels are also increased in some patients with Wolfram syndrome. Our results therefore reveal PSP/reg as a potential biomarker for beta cells under chronic ER stress, as is the case in Wolfram syndrome.
Plasmonic enhanced Cu2O-Au-BFO photocathodes for solar hydrogen production
Authors: Cheng Xiaorong , Gu Shoulin , Centeno Anthony , Dawson Graham
Published: March 2019

A novel Cu2O-Au-BFO heterostructure photocathode was constructed which significantly improved the efficiency of photo-generated carrier transfer for solar hydrogen production. A BiFeO3 (BFO) ferroelectric film was synthesized on top of a Cu2O layer by a sputtering process. The BFO layer acted to protect the Cu2O layer from photochemical corrosion, increasing photoelectrochemical (PEC) stability. The p–n heterojunction between Cu2O and BFO layers enhanced the PEC properties by suppressing charge recombination and improved interfacial charge transfer efficiency. When Cu2O and BFO are interfaced by Au Nanoparticles (NPs) the PEC performance was further enhanced, due to hot-electron transfer at the plasmonic resonance. After positive poling, the depolarization field across the whole volume of BFO film drove electrons into the electrolyte solution, inducing a significant anodic shift, Vop of 1.01 V vs. RHE, together with a significantly enhanced photocurrent density of −91 μA/cm2 at 0 V vs. RHE under 100 mW/cm2 illumination. The mechanism was investigated through experimental and theoretivcal calculations.
Reconstruction of Dynamic and Reversible Color Change using Reflectin Protein
Authors: Cai Tiantian , Han Kui , Yang Peilin , Zhu Zhou , Jiang Mengcheng , Huang Yanyi , Xie Can
Published: March 2019

Cephalopods have remarkable ability to change their body color across a wide range of wavelengths, yet the structural basis remains largely unknown. Reflectin, a protein family assumed to be responsible for structural color in cephalopods, has unique features of higher-order assembly that are tightly regulated by aromatic molecules. Here, we reconstructed the dynamic and reversible color change using purified reflectin protein and demonstrated how the conformational change and the status of assembly led to the change in optical properties. In addition, optical spectral and structural analyses indicated that the “cephalopod-blue” primarily resulted from wavelength-dependent light scattering rather than reflection. Our results suggest a possible role of reflectin in color dynamics. The in vitro reconstruction system we present here may serve as an initial step for designing bio-inspired optical materials based on reflectin protein.
Macro- and Microscopic Analyses of Anatomical Structures of Chinese Gallnuts and Their Functional Adaptation
Authors: Lu Qin , Chen Hang , Wang Chao , Yang Zi-xiang , Lü Pin , Chen Ming-shun , Chen Xiao-ming
Published: March 2019

The galls induced by Schlechtendaia chinensis, Schlechtendaia peitan and Nurudea shiraii on Rhus chinensis and gall induced by Kaburagia rhusicola rhusicola on Rhus potaninii Maxim. are the largest plant galls and have great economic and medical values. We examined the structures of galls and their functional adaptation using various macro- and microscopic techniques. The highly adapted structures include a stalk at the base that is specialized for mechanical support and transport of nutrients for aphids, and a network of vascular bundles which accompanying schizogenous ducts arranged in a way to best support aphid feeding and population growth. There are many circular and semicircular xylems traces in an ensiform gall in cross sectional views, which would provide more nutrition and occupy less space. We infer the evolution trail was flower-like gall, horned gall, circular gall and ensiform gall. And the possible evolutionary trend of the gall was bigger chamber, more stable mechanical supporting, easier for exchanging substance and transporting nutrients.
Shade and nutrient-mediated phenotypic plasticity in the miracle plant Synsepalum dulcificum (Schumach. & Thonn.) Daniell
Authors: Tchokponhoué Dèdéou A. , N’Danikou Sognigbé , Houéto Jacob S. , Achigan-Dako Enoch G.
Published: March 2019

Phenotypic plasticity as a change of genotype expression in response to environmental heterogeneity varies in magnitude among crop species and can induce a shift in a plant’s phenology. In Synsepalum dulcificum, a West African orphan fruit tree, such phenological plasticity is not well understood. Here, we hypothesize that light stimulation and changes in organic nutrient availability would induce an accelerated transition in S. dulcificum from its juvenile to its reproductive phase. We grew 14-month-old seedlings of S. dulcificum under a range of nutrient regimes, both in shade and in full sunlight, and measured their survival, vegetative growth, biomass allocation, and transition to reproductive maturity. The results reveal that S. dulcificum responds favourably to both shading and nutrient application, with the shading exhibiting a stronger influence on the measured variables. The species’ morphological plasticity, particularly in terms of plant height and stem diameter, was found to exceed both its fitness and allocational plasticities. Under the conditions examined, we observed an accelerated transition to fruiting, at an age of only 24 months. The observed plasticity suggests S. dulcificum to be an intermediate shade-tolerant species. This finding expands our knowledge on the appropriate environmental conditions for the breeding and cultivation of this species.
An integrated whole genome analysis of Mycobacterium tuberculosis reveals insights into relationship between its genome, transcriptome and methylome
Authors: Gomez-Gonzalez Paula J. , Andreu Nuria , Phelan Jody E. , de Sessions Paola Florez , Glynn Judith R. , Crampin Amelia C. , Campino Susana , Butcher Philip D. , Hibberd Martin L. , Clark Taane G.
Published: March 2019

Human tuberculosis disease (TB), caused by Mycobacterium tuberculosis (Mtb), is a complex disease, with a spectrum of outcomes. Genomic, transcriptomic and methylation studies have revealed differences between Mtb lineages, likely to impact on transmission, virulence and drug resistance. However, so far no studies have integrated sequence-based genomic, transcriptomic and methylation characterisation across a common set of samples, which is critical to understand how DNA sequence and methylation affect RNA expression and, ultimately, Mtb pathogenesis. Here we perform such an integrated analysis across 22 M. tuberculosis clinical isolates, representing ancient (lineage 1) and modern (lineages 2 and 4) strains. The results confirm the presence of lineage-specific differential gene expression, linked to specific SNP-based expression quantitative trait loci: with 10 eQTLs involving SNPs in promoter regions or transcriptional start sites; and 12 involving potential functional impairment of transcriptional regulators. Methylation status was also found to have a role in transcription, with evidence of differential expression in 50 genes across lineage 4 samples. Lack of methylation was associated with three novel variants in mamA, likely to cause loss of function of this enzyme. Overall, our work shows the relationship of DNA sequence and methylation to RNA expression, and differences between ancient and modern lineages. Further studies are needed to verify the functional consequences of the identified mechanisms of gene expression regulation.
Solid–liquid interface optimization and properties of ultra-wide bandgap β-Ga2O3grown by Czochralski and EFG methods
Authors: Mu Wenxiang , Jia Zhitai , Yin Yanru , Fu Bo , Zhang Jin , Zhang Jian , Tao Xutang
Published: March 2019

The solid–liquid interface and crystal growth habit of β-Ga2O3have been studied in the Czochralski and modified EFG methods.
CBS extrapolation of Hartree–Fock energy: Pople and Dunning basis sets hand-to-hand on the endeavour
Authors: Varandas A. J. C.
Published: March 2019

Hartree–Fock hierarchical staircase makes all basis sets go hand-in-hand.
Femtoliter nanofluidic valve utilizing glass deformation
Authors: Kazoe Yutaka , Pihosh Yuriy , Takahashi Hitomi , Ohyama Takeshi , Sano Hiroki , Morikawa Kyojiro , Mawatari Kazuma , Kitamori Takehiko
Published: March 2019

A femtoliter nanochannel open/close valve utilizing tiny glass deformation, which will enable highly-integrated glass nanofluidic devices, was proposed and demonstrated.
Stimuli-enabled switch-like paracetamol electrochemical sensor based on thermosensitive polymer and MWCNTs-GQDs composite nanomaterial
Authors: Zhao Pengcheng , Ni Meijun , Chen Chao , Zhou Zhidu , Li Xiping , Li Chunyan , Xie Yixi , Fei Junjie
Published: March 2019

The reversible and temperature-controlled electrochemical response of the thermosensitive polymer PS-PNIPAm-PS/MWCNTs-GQDs/GCE to paracetamol.
A facile method to synthesize CoV2O6 as a high-performance supercapacitor cathode
Authors: He Xinrui , Jiang Jing , Tian Hanqing , Niu Yi , Li Zhipeng , Hu Yalin , Fan Jiahao , Wang Chao
Published: March 2019

A facile chemical co-precipitation process to synthesize CoV2O6, which exhibits high capacity and cycling stability (83.3% after 20 000 cycles).
Toward an alternative approach for the preparation of low-temperature titanium dioxide blocking underlayers for perovskite solar cells
Authors: Aung Su Htike , Zhao Lichen , Nonomura Kazuteru , Oo Than Zaw , Zakeeruddin Shaik M. , Vlachopoulos Nick , Sloboda Tamara , Svanström Sebastian , Cappel Ute B. , Hagfeldt Anders , Grätzel Michael
Published: March 2019

The anodic electrodeposition method is investigated as an alternative technique for the preparation of a titanium oxide blocking underlayer for perovskite solar cells.
A two-dimensional ion-pump of a vanadium pentoxide nanofluidic membrane
Authors: Gogoi Raj Kumar , Neog Arindom Bikash , Konch Tukhar Jyoti , Sarmah Neelam , Raidongia Kalyan
Published: March 2019

The reactive surface and layered crystal structure of vanadium pentoxide (V2O5) are exploited here to prepare a two-dimensional (2D) ion pump that transports ions against their concentration gradient.
A gadolinium-complex-based theranostic prodrug for in vivo tumour-targeted magnetic resonance imaging and therapy
Authors: Yang Zhaoxuan , Lin Hongyu , Huang Jiaqi , Li Ao , Sun Chengjie , Richmond Jonathan , Gao Jinhao
Published: March 2019

A molecular theranostic prodrug for treatment of tumour and real-time monitoring via MRI in vivo was reported.
Nanoscopic insights of saline water in carbon nanotube appended filters using molecular dynamics simulations
Authors: Sahu Pooja , Musharaf Ali Sk. , Shenoy K. T. , Mohan S.
Published: March 2019

Nanotube appended membranes are shown to be very promising due to their ultrafast water transport and very high salt rejection ability.
Versatile catalysts constructed from hybrid polyoxomolybdates for simultaneously detoxifying sulfur mustard and organophosphate simulants
Authors: Hou Yujiao , An Haiyan , Chang Shenzhen , Zhang Jie
Published: March 2019

Twelve new hybrid dimers based on carboxylic acid ligand modified polyoxomolybdates were prepared, which can rapidly oxidize the mustard gas simulant, CEES, and hydrolyze the nerve agent simulant, DECP, at room temperature.
Immature dendritic cells navigate microscopic mazes to find tumor cells
Authors: Um Eujin , Oh Jung Min , Park Juhee , Song Taegeun , Kim Tae-Eon , Choi Yongjun , Shin Changsik , Kolygina Diana , Jeon Jae-Hyung , Grzybowski Bartosz A. , Cho Yoon-Kyoung
Published: March 2019

Imposing physical confinements in the migration tracks of dendritic cells reveals different migratory behaviors towards cancer vs. normal cells.
Generating digital drug cocktails via optical manipulation of drug-containing particles and photo-patterning of hydrogels
Authors: Chen Yi-Sin , Chung Ko-Chin , Huang Wen-Yen , Lee Wen-Bin , Fu Chien-Yu , Wang Chih-Hung , Lee Gwo-Bin
Published: March 2019

An integrated microfluidic system combining 1) ODEP for manipulation of drug-containing particles and 2) UV “direct writing” capable of patterning hydrogels was established for automatic formulation of customized digital drug cocktails.
Assessing size-dependent cytotoxicity of boron nitride nanotubes using a novel cardiomyocyte AFM assay
Authors: Augustine Jerry , Cheung Timothy , Gies Valerie , Boughton Jennifer , Chen Maohui , Jakubek Zygmunt J. , Walker Steven , Martinez-Rubi Yadienka , Simard Benoit , Zou Shan
Published: March 2019

A novel AFM-based assay was in agreement with traditional cytotoxicity assays and exposed a size-dependent toxicity of boron nitride nanotubes.
Ion imprinted dual reference ratiometric fluorescence probe for respective and simultaneous detection of Fe3+ and Cu2+
Authors: Ying Rongjian , Lu Hongzhi , Xu Shoufang
Published: March 2019

Dual detection of two kinds of metal ions was achieved by a dual reference ratiometric fluorescence probe.
Three-dimensional N-doped graphene aerogel-supported Pd nanoparticles as efficient catalysts for solvent-free oxidation of benzyl alcohol
Authors: Wei Qiuli , Liu Tongjun , Wang Yuanyuan , Dai Liyi
Published: March 2019

3D Pd/NRGO with large surface areas and abundant porous structures was prepared, which served as a novel support to enhance the catalytic properties of noble metal catalysts for the solvent-free selective oxidation of benzyl alcohol.
Effects of temperature and pore structure on the release of methane in zeolite nanochannels
Authors: Cheng Xu , Li Zhigang , He Ya-Ling
Published: March 2019

The effects of temperature and pore size on release of methane in zeolite nanochannels is investigated by molecular dynamics simulations.
Tendomers – force sensitive bis-rotaxanes with jump-like deformation behavior
Authors: Müller Toni , Sommer Jens-Uwe , Lang Michael
Published: March 2019

Tendomers (pairs of rotaxanes connected at the first slide ring) display a jump-like strain softening under an applied external force with a switching point that is set by the slide ring density.
Supramolecular hydrogel with tunable multi-color and white-light fluorescence from sulfato-β-cyclodextrin and aminoclay
Authors: Niu Jie , Chen Yong , Liu Yu
Published: March 2019

A multi-color-tunable supramolecular hydrogel with fluorescence can be tuned by adjusting the molar ratio of host and guest.
Improving physical layer security jointly using full‐duplex jamming receiver and multi‐antenna jammer in wireless networks
Authors: Ma Rui , Yang Shizhong , Du Min , Wu Haowei , Ou Jinglan
Published: March 2019

The issues of the physical layer security are studied, where one transmitter (Alice), one full‐duplex (FD) legitimate receiver (Bob) and one multi‐antenna jammer (Charlie) are considered to defend against multiple passive and non‐colluding eavesdroppers (Eves), for multiple‐input multiple‐output wiretap channels. With the assumption that the complete channel state information (CSI) for main channels and the statistical CSI for Eves' channels are available, an improved secrecy transmission design is proposed to minimise the secrecy outage probability (SOP), under the minimum secrecy rate requirement. In addition to integrating artificial noise aided transmit beamforming and multi‐antenna cooperative jammer to impair Eves' channels, which is widely used in many existing works, a FD legitimate receiver is applied together to further enhance physical layer security. Based on the basic probability theory and convex optimisation, the accurate closed‐form expression of the SOP is derived, and the impacts on secrecy performance are described, including the qualities of main channels, the Alice's transmit power and the number of Eves. Numerical results show that the proposed scheme using the FD Bob can significantly enhance the system security, as compared with that employing the half‐duplex Bob.
Robust sampling‐based switching design for piecewise affine systems with application to DC–DC converters
Authors: Wang Tao , Liu Yuwen , Wang Xijun , Li Jikun
Published: March 2019

The problem of designing the switching rules for piecewise affine systems which satisfy dwell time constraints is studied. With a proposed sampling‐based approach which is different from existing traditional switching laws, the system can be updated and switched only at sampling instants. First, a sufficient condition for stability of piecewise linear affine systems converging to an invariant set is developed in the framework of the sampling‐based switching, for which the lengths between successive sampling instants are assumed to be fixed. The corresponding sampled‐based switching rules are obtained by solving a family of the linear matrix inequalities. Subsequently, these sampling lengths are extended from a fixed value to a certain interval and robust switching rules are obtained. Systems using these switching rules have the insensitivity to sampling period perturbation. Finally, an application to a DC–DC converter is provided to demonstrate the effectiveness of the proposed method.
Robust state estimation for non‐linear systems with unknown delays
Authors: Nguyen Cuong M. , Pathirana Pubudu N. , Trinh Hieu
Published: March 2019

In this study, the authors consider the state estimation problem for a class of non‐linear systems with unknown time‐varying delays. Based on the filtering method, they propose a new observer design approach where the states of the non‐linear systems with unknown delays can be robustly estimated. While relevant results in the literature assume the unknown delays to be differentiable, the observer design proposed in this study only requires the knowledge of the unknown delays' upper and lower bounds which can be obtained in practical systems. The new observer design approach also allows us to consider delays in the output measurements. They further utilise the linear parameter varying approach to relax the conservativeness imposed on observer design conditions by the Lipschitz conditions. To show the effectiveness of the new results, the single‐link joint robotic system and the pendulum system are considered as illustrative examples.
Spectral perspective on stability and stabilisation of continuous‐time mean‐field stochastic systems
Authors: Ma Limin , Zhang Weihai , Xia Jianwei
Published: March 2019

This mainly studies the mean square stabilisability, interval stability and stabilisation of mean‐field stochastic control systems. A necessary and sufficient condition for stabilisation of continuous‐time mean‐field stochastic systems is presented via operator spectrum technique. The unremovable spectrum is generalised to mean‐field stochastic differential equations (MF‐SDEs), and a necessary and sufficient condition for unremovable spectrum is obtained. Three operators defined in different domains are given to characterise the stabilisability of MF‐SDEs. As applications, an example is given to illustrate their relationships. Interval stability and stabilisation are generalised to MF‐SDEs, and a necessary condition for interval stability is given to show the relationship among interval stability, the decay rate of the system state response and the Lyapunov exponent. A sufficient condition for interval stabilisation is proposed via linear matrix inequality approach.
Equivalent circuit method for circulating current loss of transposed strands in multi‐turn coil of a canned induction motor
Authors: Wang Dongmei , Liang Yanping , Bian Xu , Gao Lianlian , Wang Chenguang , Qiao Xue
Published: March 2019

For the particularity of the transposition method in large induction motor, the equivalent circuit method for the circulating current losses of the transposed strands in stator winding with multi‐turn coil is put forward. According to the unified theory of the electromagnetic field‐circuit and combining with the distribution of various leakage magnetic fields of stator winding, the general circuit network model of the stator winding is proposed, which can be applicable to different transposition angles with the consideration of the accurate distribution of leakage magnetic fields. With the basic idea of discrete points and the linearisation, the method for the leakage reactance of the transposed strands is given with an application in a 5.5 MW nuclear power pump canned induction motor, which uses the strand slot leakage reactance and the end leakage reactance to simulate the slot leakage magnetic field and the end leakage magnetic field. Through experiment, the equivalent circuit method for the circulating current losses of the transposed strands in multi‐turn coil is verified, which will provide a reference for the winding design and the winding loss calculation of the large induction motor.
Detection of inconspicuous power quality disturbances through step changes in rms voltage profile
Authors: Furlani Bastos Alvaro , Freitas Walmir , Todeschini Grazia , Santoso Surya
Published: March 2019

Power quality disturbances commonly observed in power systems have been studied for decades, resulting in numerous algorithms for detecting the events that affect the voltage and/or current waveforms. However, a considerable amount of disturbances is not visually observable in the raw waveforms, especially switching operations. These events must be detected through an alternative feature, such as abrupt variations in the root‐mean‐square (rms) voltage profile. This study examines the methods commonly used for detecting power quality disturbances in the waveform or rms voltage profile domains and identifies their limitations. Afterwards, a novel step change detector is proposed based on a modified median filter and rms voltage gradient values to overcome the deficiencies of the existing methods. The effectiveness of the proposed method is assessed by applying it to both simulated and field data. This assessment shows that the method detects all switching events with no false positives for the datasets under analysis.
Distributed secondary control based on cluster consensus of inhibitory coupling with power limit for isolated multi‐microgrid
Authors: Gong Pingping , Lu Ziguang , Lin Jingyu , Lv Zhilin , Hu Likun
Published: March 2019

Multiple nearby isolated microgrids (MGs) can be interconnected to become multi‐MGs (MMGs) and meet larger bulk power demands, thus improving reliability/security of MMGs and reducing the power supply investment costs. However, a multi‐layer control structure and complex communication network are inevitable, which increase communication delays and complicate the control structure. To solve this problem, this article introduces a distributed secondary control (DSC) based on cluster consensus of inhibitory coupling with a power limit scheme. Compared with an inter‐cluster communication coupling structure, the communication channels of the proposed scheme are minimised to simplify network topology, decrease the communication delays and control dimensions. The proposed control strategy reaches multi‐valued consensus states for accurate active/reactive power sharing in different MGs. Furthermore, active/reactive power overloading in a MG cluster is discussed under an inhibitory coupling configuration. Based on the power limit scheme, each distributed generator (DG) of the overloaded MG is controlled to generate power within the rated power range for high local autonomy. In addition, an adaptive virtual impedance control is introduced to decrease voltage deviations between DGs. The analytical results are verified by a simulation in MATLAB/Simulink.
DormTalk: edge computing for the dormitory applications on campus
Authors: Lin Yi‐Bing , Shieh Min‐Zheng , Lin Yun‐Wei
Published: March 2019

Internet of things (IoT) connects a large number of edge IoT devices to produce huge volumes of data. To effectively manipulate the real‐time IoT data, it is essential to integrate edge computing with the cloud computing. This study investigates how real‐time IoT applications benefit from edge computing. Specifically, the authors show how edge computing and cloud computing can be nicely integrated to build a smart campus environment in National Chiao Tung University (NCTU). Based on an IoT device management platform called IoTtalk, the authors develop an edge IoT computing system called DromTalk for dormitory applications in NCTU. Conventional approaches are difficult to interact with IoT servers of different platforms. The authors’ approach proposes a novel method that uses a cyber IoT device to nicely bridge the IoTtalk server in the cloud and the DormTalk servers at various dormitory buildings (the edges) without modifying these servers. The authors investigate the response time performance of the edge DormTalk server, which shows that smartphones can effectively control the dormitory appliances with good user experience.
Mainlobe jamming suppression for distributed radar via joint blind source separation
Authors: Ge Mengmeng , Cui Guolong , Kong Lingjiang
Published: March 2019

In the presence of the mainlobe jamming, the performance of the modern radar system would degrade significantly, i.e. increasing probabilities of false alarm and loss detection. In this study, the authors consider the jamming suppression problem in noise environment for the distributed radar with single transmitter and multiple receivers, where the multiple jammings enter into all the receivers through the main beam of the antennas. A framework based on joint blind source separation (JBSS) is proposed. First, the signal model accounting for both the target and jammings is developed. Second, the target and the jamming signals are separated by exploiting the generalised non‐orthogonal joint diagonalisation JBSS method. Then, the separated target signals are employed to find the target location with the elliptic location method. Finally, they assess the performance in noise environment by numerical simulations, and the results show that the proposed algorithm can suppress successfully quite a lot different kinds of jamming signals, e.g. the noise‐modulated and the digital radio‐frequency memory jammings.
SAR platform positioning method based on improved Gauss–Newton–genetic hybrid algorithm
Authors: Liang Yi , Sun Kun , Dang Yanfeng , Li Qingqing , Wu Jianxin , Xing Mengdao
Published: March 2019

The traditional synthetic aperture radar (SAR) platform positioning methods based on the range‐Doppler domain data, velocity and altitude information of the platform exist a large approximation error, which will not satisfy the requirement of accurate navigation. Additionally, the traditional positioning methods for solving non‐linear equations are challenging due to the risk of falling into local optimal solution. In order to solve these problems, a new robust SAR platform positioning method based on the improved Gauss–Newton–genetic hybrid (GNGH) algorithm is proposed in this study. First, the position information of multi‐feature points in geographic and imaging coordinate systems is acquired by adopting the image matching. Furthermore, the coordinate transformation is introduced to realise the uniform of feature point coordinates between the different coordinate systems. Finally, the accurate position of the platform is calculated through introducing GNGH algorithm to solve the non‐linear equations constructed by the corresponding slant range information. So the trajectory deviation can be corrected effectively. Moreover, the proposed method can reduce the computation load and positioning error dramatically. The effectiveness of the proposed approach is confirmed and demonstrated via simulation and experimental results.