bluuebunny/crossref_metadata_2025 huggingface dataset:
RAC1B Suppresses TGF-β-Dependent Chemokinesis and Growth Inhibition through an Autoregulatory Feed-Forward Loop Involving PAR2 and ALK5
Authors: Otterbein Hannah , Mihara Koichiro , Hollenberg Morley D. , Lehnert Hendrik , Witte David , Ungefroren Hendrik
Published: August 2019

The small GTPase RAC1B functions as a powerful inhibitor of transforming growth factor (TGF)-β1-induced epithelial-mesenchymal transition, cell motility, and growth arrest in pancreatic epithelial cells. Previous work has shown that RAC1B downregulates the TGF-β type I receptor ALK5, but the molecular details of this process have remained unclear. Here, we hypothesized that RAC1B-mediated suppression of activin receptor-like kinase 5 (ALK5) involves proteinase-activated receptor 2 (PAR2), a G protein-coupled receptor encoded by F2RL1 that is crucial for sustaining ALK5 expression. We found in pancreatic carcinoma Panc1 cells that PAR2 is upregulated by TGF-β1 in an ALK5-dependent manner and that siRNA-mediated knockdown of RAC1B increased both basal and TGF-β1-induced expression of PAR2. Further, the simultaneous knockdown of PAR2 and RAC1B rescued Panc1 cells from a RAC1B knockdown-induced increase in ALK5 abundance and the ALK5-mediated increase in TGF-β1-induced migratory activity. Conversely, Panc1 cells with stable ectopic expression of RAC1B displayed reduced ALK5 expression, an impaired upregulation of PAR2, and a reduced migratory responsiveness to TGF-β1 stimulation. However, these effects could be reversed by ectopic overexpression of PAR2. Moreover, the knockdown of PAR2 alone in Panc1 cells and HaCaT keratinocytes phenocopied RAC1B’s ability to suppress ALK5 abundance and TGF-β1-induced chemokinesis and growth inhibition. Lastly, we found that the RAC1B knockdown-induced increase in TGF-β1-induced PAR2 mRNA expression was sensitive to pharmacological inhibition of MEK-ERK signaling. Our data show that in pancreatic and skin epithelial cells, downregulation of ALK5 activity by RAC1B is secondary to suppression of F2RL1/PAR2 expression. Since F2RL1 itself is a TGF-β target gene and its upregulation by TGF-β1 is mediated by ALK5 and MEK-ERK signaling, we suggest the existence of a feed-forward signaling loop involving ALK5 and PAR2 that is efficiently suppressed by RAC1B to restrict TGF-β-driven cell motility and growth inhibition.
Hyper-Activation of STAT3 Sustains Progression of Non-Papillary Basal-Type Bladder Cancer via FOSL1 Regulome
Authors: Benerini Gatta Luisa , Melocchi Laura , Bugatti Mattia , Missale Francesco , Lonardi Silvia , Zanetti Benedetta , Cristinelli Luca , Belotti Sandra , Simeone Claudio , Ronca Roberto , Grillo Elisabetta , Licini Sara , Bresciani Debora , Tardanico Regina , Chan Szeman Ruby , Giurisato Emanuele , Calza Stefano , Vermi William
Published: August 2019

Urothelial bladder cancer (UBC) are classified into luminal and basal subtypes showing distinct molecular features and clinical behaviour. Recent in silico data have proposed the activation on the Signal Transducer and Activator of Transcription 3 (STAT3) as relevant transcription factor in UBC. To answer this question, we have combined the retrospective analysis of clinical samples, functional assays on cell lines, interrogation of public UBC datasets and a murine model of basal-type UBC. Immunohistochemistry on a retrospective UBC cohort uncovered that STAT3 Y705 phosphorylation (pSTAT3) is significantly increased in infiltrating basal-type UBC compared to luminal UBC. In vitro, STAT3 silencing in UBC cell lines significantly reduced tumor cell viability and invasion. Gene expression profile of UBC cell lines combined with the analysis of the Cancer Genome Atlas (TCGA) and GSE32894 UBC datasets showed that increased expression of a set of STAT3 targets predicts basal-type, propensity to local progression and worse prognosis. MYC and FOSL1 represent relevant STAT3 downstream targets, as validated by their co-localization in pSTAT3+ UBC cancer cells. These findings were largely reproduced in the BBN-induced murine model of basal-type UBC. Of note, FOSL1 protein resulted strongly expressed in the non-papillary UBC pathway and FOSL1-regulated transcripts were significantly enriched in the transition from NMIBC to MIBC, as indicated by the interrogation of the GSE32894 dataset. The blockade of the STAT3 pathway might represent a novel treatment option for these neoplasms. Monitoring pSTAT3 and the downstream targets, particularly FOSL1, could provide meaningful levels of UBC stratification.
Integrin-Mediated TGFβ Activation Modulates the Tumour Microenvironment
Authors: Brown Nicholas F. , Marshall John F.
Published: August 2019

TGFβ (transforming growth factor-beta) is a pleotropic cytokine with contrasting effects in cancer. In normal tissue and early tumours, TGFβ acts as a tumour suppressor, limiting proliferation and inducing apoptosis. However, these effects are eventually abrogated by the loss or inactivation of downstream signalling within the TGFβ pathway, and in established tumours, TGFβ then acts as a tumour promotor through multiple mechanisms including inducing epithelial-to-mesenchymal transition (EMT), promoting formation of cancer-associated fibroblasts (CAFs) and increasing angiogenesis. TGFβ is secrereted as a large latent complex and is embedded in the extracellular matrix or held on the surface of cells and must be activated before mediating its multiple functions. Thus, whilst TGFβ is abundant in the tumour microenvironment (TME), its functionality is regulated by local activation. The αv-integrins are major activators of latent-TGFβ. The potential benefits of manipulating the immune TME have been highlighted by the clinical success of immune-checkpoint inhibitors in a number of solid tumour types. TGFβ is a potent suppressor of T-cell-mediated immune surveillance and a key cause of resistance to checkpoint inhibitors. Therefore, as certain integrins locally activate TGFβ, they are likely to have a role in the immunosuppressive TME, although this remains to be confirmed. In this review, we discussed the role of TGFβ in cancer, the role of integrins in activating TGFβ in the TME, and the potential benefits of targeting integrins to augment immunotherapies.
Regarding the Nature of Charge Carriers Formed by UV or Visible Light Excitation of Carbon-Modified Titanium Dioxide
Authors: Arimi Arsou , Günnemann Carsten , Curti Mariano , Bahnemann Detlef W.
Published: August 2019

Although titanium dioxide gathers many of the required properties for its application in photocatalytic processes, its lack of activity in the visible range is a major hurdle yet to be overcome. Among different strategies, the post-synthesis modification of TiO2 powders with organic compounds has already led to commercially available materials, such as KRONOClean 7000. In this work, we apply diffuse reflectance transient absorption spectroscopy on this visible-light active photocatalyst and study the dynamics of the charge carriers alternatively induced by UV or visible light laser irradiation, under inert or reactive atmospheres. Our results can be interpreted by considering the material as TiO2 sensitized by an organic-based layer, in agreement with previous studies on it, and show that the oxidative power of the material is considerably diminished under visible light irradiation. By complementarily performing continuous visible light irradiation photocatalysis experiments in aerated aqueous suspensions, we show that, although the oxidation of methanol proceeds at a very slow rate, the oxidation of chlorpromazine occurs much faster thanks to its better suited redox potential.
Detoxification of Cylindrospermopsin by Pyrite in Water
Authors: Wang Shulian , Chen Yongmei , Jiao Yiying , Li Zhu
Published: August 2019

Cylindrospermopsin (CYN) is a cyanobacterial toxin released from eutrophic water. It persistently remains in the environment because its degradation under solar light is extremely low. In this study, pyrite, an abundant mineral, was investigated as a catalyst for decomposing and detoxifying CYN in water. A detailed examination of intermediates provided insights into the degradation pathway. Electron spin resonance spectra revealed that H2O2 and hydroxyl radicals (•OH) were generated at the pyrite surface while promoting the recycling of Fe(III) into Fe(II) during the degradation process. This degradation system could be uniquely efficient in the presence of relatively high levels of natural organic matter because the structure of the uracil ring is decomposed to detoxify CYN. This work confirms a new approach to selectively and effectively detoxifying CYN in water using an inexpensive, environmentally friendly, and bio-compatible mineral.
Theoretical Determination of Size Effects in Zeolite-Catalyzed Alcohol Dehydration
Authors: Kunz Larissa Y. , Bu Lintao , Knott Brandon C. , Liu Cong , Nimlos Mark R. , Assary Rajeev S. , Curtiss Larry A. , Robichaud David J. , Kim Seonah
Published: August 2019

In the upgrading of biomass pyrolysis vapors to hydrocarbons, dehydration accomplishes a primary objective of removing oxygen, and acidic zeolites represent promising catalysts for the dehydration reaction. Here, we utilized density functional theory calculations to estimate adsorption energetics and intrinsic kinetics of alcohol dehydration over H-ZSM-5, H-BEA, and H-AEL zeolites. The ONIOM (our Own N-layered Integrated molecular Orbital and molecular Mechanics) calculations of adsorption energies were observed to be inconsistent when benchmarked against QM (Quantum Mechanical)/Hartree–Fock and periodic boundary condition calculations. However, reaction coordinate calculations of adsorbed species and transition states were consistent across all levels considered. Comparison of ethanol, isopropanol (IPA), and tert-amyl alcohol (TAA) over these three zeolites allowed for a detailed examination of how confinement impacts on reaction mechanisms and kinetics. The TAA, seen to proceed via a carbocationic mechanism, was found to have the lowest activation barrier, followed by IPA and then ethanol, both of which dehydrate via a concerted mechanism. Barriers in H-BEA were consistently found to be lower than in H-ZSM-5 and H-AEL, attributed to late transition states and either elevated strain or inaccurately estimating long-range electrostatic interactions in H-AEL, respectively. Molecular dynamics simulations revealed that the diffusivity of these three alcohols in H-ZSM-5 were significantly overestimated by Knudsen diffusion, which will complicate experimental efforts to develop a kinetic model for catalytic fast pyrolysis.
New Cu4Na4- and Cu5-Based Phenylsilsesquioxanes. Synthesis via Complexation with 1,10-Phenanthroline, Structures and High Catalytic Activity in Alkane Oxidations with Peroxides in Acetonitrile
Authors: Astakhov Grigorii , Levitsky Mikhail , Korlyukov Alexander , Shul’pina Lidia , Shubina Elena , Ikonnikov Nikolay , Vologzhanina Anna , Bilyachenko Aleksey , Dorovatovskii Pavel , Kozlov Yuriy , Shul’pin Georgiy
Published: August 2019

Self-assembly of copper(II)phenylsilsesquioxane assisted by the use of 1,10-phenanthroline (phen) results in isolation of two unusual cage-like compounds: (PhSiO1,5)12(CuO)4(NaO0.5)4(phen)4 1 and (PhSiO1,5)6(PhSiO1,5)7(HO0.5)2(CuO)5(O0.25)2(phen)3 2. X-Ray diffraction study revealed extraordinaire molecular architectures of both products. Namely, complex 1 includes single cyclic (PhSiO1,5)12 silsesquioxane ligand. Four sodium ions of 1 are additionally ligated by 1,10-phenanthrolines. In turn, “sodium-less” complex 2 represents coordination of 1,10-phenanthrolines to copper ions. Two silsesquioxane ligands of 2 are: (i) noncondensed cubane of a rare Si6-type and (ii) unprecedented Si7-based ligand including two HOSiO1.5 fragments. These silanol units were formed due to removal of phenyl groups from silicon atoms, observed in mild conditions. The presence of phenanthroline ligands in products 1 and 2 favored the π–π stacking interactions between neighboring cages. Noticeable that in the case of 1 all four phenanthrolines participated in such supramolecular organization, unlike to complex 2 where one of the three phenanthrolines is not “supramolecularly active”. Complexes 1 and 2 were found to be very efficient precatalysts in oxidations with hydroperoxides. A new method for the determination of the participation of hydroxyl radicals has been developed.
Physioxia Has a Beneficial Effect on Cartilage Matrix Production in Interleukin-1 Beta-Inhibited Mesenchymal Stem Cell Chondrogenesis
Authors: Pattappa Girish , Schewior Ruth , Hofmeister Isabelle , Seja Jennifer , Zellner Johannes , Johnstone Brian , Docheva Denitsa , Angele Peter
Published: August 2019

Osteoarthritis (OA) is a degenerative condition that involves the production of inflammatory cytokines (e.g., interleukin-1β (IL-1β), tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6)) that stimulate degradative enzymes, matrix metalloproteinases (MMPs) and aggrecanases (ADAMTS) resulting in articular cartilage breakdown. The presence of interleukin-1β (IL-1β) is one reason for poor clinical outcomes in current cell-based tissue engineering strategies for treating focal early osteoarthritic defects. Mesenchymal stem cells (MSCs) are a potential cell source for articular cartilage regeneration, although IL-1β has been shown to inhibit in vitro chondrogenesis. In vivo, articular chondrocytes reside under a low oxygen environment between 2–5% oxygen (physioxia) and have been shown to enhance in vitro MSC chondrogenic matrix content with reduced hypertrophic marker expression under these conditions. The present investigation sought to understand the effect of physioxia on IL-1β inhibited MSC chondrogenesis. MSCs expanded under physioxic (2% oxygen) and hyperoxic (20%) conditions, then chondrogenically differentiated as pellets in the presence of TGF-β1 and either 0.1 or 0.5 ng/mL IL-1β. Results showed that there were donor variations in response to physioxic culture based on intrinsic GAG content under hyperoxia. In physioxia responsive donors, MSC chondrogenesis significantly increased GAG and collagen II content, whilst hypertrophic markers were reduced compared with hyperoxia. In the presence of IL-1β, these donors showed a significant increase in cartilage matrix gene expression and GAG content relative to hyperoxic conditions. In contrast, a set of MSC donors were unresponsive to physioxia and showed no significant increase in matrix production independent of IL-1β presence. Thus, physioxia has a beneficial effect on MSC cartilage matrix production in responsive donors with or without IL-1β application. The mechanisms controlling the MSC chondrogenic response in both physioxia responsive and unresponsive donors are to be elucidated in future investigations.
DROSHA-Dependent AIM2 Inflammasome Activation Contributes to Lung Inflammation during Idiopathic Pulmonary Fibrosis
Authors: Cho Soo Jung , Hong Kyoung Sook , Jeong Ji Hun , Lee Mihye , Choi Augustine M. K. , Stout-Delgado Heather W. , Moon Jong-Seok
Published: August 2019

Idiopathic pulmonary fibrosis (IPF) has been linked to chronic lung inflammation. Drosha ribonuclease III (DROSHA), a class 2 ribonuclease III enzyme, plays a key role in microRNA (miRNA) biogenesis. However, the mechanisms by which DROSHA affects the lung inflammation during idiopathic pulmonary fibrosis (IPF) remain unclear. Here, we demonstrate that DROSHA regulates the absent in melanoma 2 (AIM2) inflammasome activation during idiopathic pulmonary fibrosis (IPF). Both DROSHA and AIM2 protein expression were elevated in alveolar macrophages of patients with IPF. We also found that DROSHA and AIM2 protein expression were increased in alveolar macrophages of lung tissues in a mouse model of bleomycin-induced pulmonary fibrosis. DROSHA deficiency suppressed AIM2 inflammasome-dependent caspase-1 activation and interleukin (IL)-1β and IL-18 secretion in primary mouse alveolar macrophages and bone marrow-derived macrophages (BMDMs). Transduction of microRNA (miRNA) increased the formation of the adaptor apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) specks, which is required for AIM2 inflammasome activation in BMDMs. Our results suggest that DROSHA promotes AIM2 inflammasome activation-dependent lung inflammation during IPF.
Closer to Nature Through Dynamic Culture Systems
Authors: Wong Tzyy-Yue , Chang Sheng-Nan , Jhong Rong-Chang , Tseng Ching-Jiunn , Sun Gwo-Ching , Cheng Pei-Wen
Published: August 2019

Mechanics in the human body are required for normal cell function at a molecular level. It is now clear that mechanical stimulations play significant roles in cell growth, differentiation, and migration in normal and diseased cells. Recent studies have led to the discovery that normal and cancer cells have different mechanosensing properties. Here, we discuss the application and the physiological and pathological meaning of mechanical stimulations. To reveal the optimal conditions for mimicking an in vivo microenvironment, we must, therefore, discern the mechanotransduction occurring in cells.
Mismatched Prenatal and Postnatal Maternal Depressive Symptoms and Child Behaviours: A Sex-Dependent Role for NR3C1 DNA Methylation in the Wirral Child Health and Development Study
Authors: Hill Jonathan , Pickles Andrew , Wright Nicola , Quinn John P. , Murgatroyd Chris , Sharp Helen
Published: August 2019

Evolutionary hypotheses predict that male fetuses are more vulnerable to poor maternal conditions (Sex-biased Maternal Investment), but female fetuses are at greater risk of glucocorticoid-mediated disorders where there is a mismatch between fetal and postnatal environments (Predictive Adaptive Response). Self-reported prenatal and postnatal depression and maternal report of child anxious-depressed symptoms at 2.5, 3.5 and 5.0 years were obtained from an ‘extensive’ sample of first-time mothers (N = 794). Salivary NR3C1 1-F promoter methylation was assayed at 14 months in an ‘intensive’ subsample (n = 176) and stratified by psychosocial risk. Generalised structural equation models were fitted and estimated by maximum likelihood to allow the inclusion of participants from both intensive and extensive samples. Postnatal depression was associated with NR3C1 methylation and anxious-depressed symptoms in daughters of mothers with low prenatal depression (prenatal-postnatal depression interaction for methylation, p < 0.001; for child symptoms, p = 0.011). In girls, NR3C1 methylation mediated the association between maternal depression and child anxious-depressed symptoms. The effects were greater in girls than boys: the test of sex differences in the effect of the prenatal-postnatal depression interaction on both outcomes gave X2 (2) = 5.95 (p = 0.051). This was the first human study to show that epigenetic and early behavioural outcomes may arise through different mechanisms in males and females.
MHC Genomics and Disease: Looking Back to Go Forward
Authors: Dawkins Roger L. , Lloyd Sally S.
Published: August 2019

Ancestral haplotypes are conserved but extremely polymorphic kilobase sequences, which have been faithfully inherited over at least hundreds of generations in spite of migration and admixture. They carry susceptibility and resistance to diverse diseases, including deficiencies of CYP21 hydroxylase (47.1) and complement components (18.1), as well as numerous autoimmune diseases (8.1). The haplotypes are detected by segregation within ethnic groups rather than by SNPs and GWAS. Susceptibility to some other diseases is carried by specific alleles shared by multiple ancestral haplotypes, e.g., ankylosing spondylitis and narcolepsy. The difference between these two types of association may explain the disappointment with many GWAS. Here we propose a pathway for combining the two different approaches. SNP typing is most useful after the conserved ancestral haplotypes have been defined by other methods.
Fisetin Suppresses the Proliferation and Metastasis of Renal Cell Carcinoma through Upregulation of MEK/ERK-Targeting CTSS and ADAM9
Authors: Hsieh Min-Hong , Tsai Jen-Pi , Yang Shun-Fa , Chiou Hui-Ling , Lin Chia-Liang , Hsieh Yi-Hsien , Chang Horng-Rong
Published: August 2019

Fisetin, a natural flavonoid, is known to have anticarcinogenic effects against several cancers, but its role in mediating renal cell carcinoma (RCC) progression has not been delineated. Cell viability, cytotoxicity, and cell cycle distribution were measured using the 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay and propidium iodide staining with flow cytometry. The in vitro migration and invasion assay was used to examine in vivo cell migration and invasion. Human protease antibody array analysis was conducted with cell migration/invasion-related proteins. Western blotting and quantitative reverse transcription polymerase chain reaction were used for assessing protein expression related to the cell cycle, cell invasion, and mitogen-activated protein kinase (MAPK) signaling pathway. We found that fisetin significantly inhibited cell viability through cell cycle arrest in the G2/M phase, in addition to downregulating cyclin D1 and upregulating p21/p27. Fisetin inhibited the migration and invasion of human RCC cells through the downregulation of CTSS and a disintegrin and metalloproteinase 9 (ADAM9). Fisetin also upregulated ERK phosphorylation in 786-O and Caki-1 cells. Furthermore, treatment with a MEK inhibitor (UO126) reduced the inhibitory effects of fisetin on the metastasis of RCC cells through the ERK/CTSS/ADAM9 pathway. Fisetin inhibits proliferation and metastasis of RCC cells by downregulating CTSS and ADAM9 through the MEK/ERK signaling pathway. These findings indicate that fisetin is a promising antitumor agent against RCC.
Defining Crop–Climate Departure in West Africa: Improved Understanding of the Timing of Future Changes in Crop Suitability
Authors: Egbebiyi Temitope S. , Crespo Olivier , Lennard Chris
Published: August 2019

The future climate is projected to change rapidly with potentially severe consequences for global food security. This study aims to improve the understanding of future changes in the suitability of crop growth conditions. It proposes a definition of crop realization, of the climate departure from recent historical variability, or crop–climate departure. Four statistically downscaled and bias-corrected Global Climate Models (GCMs): CCCMA, CNRM5, NOAA-GFDL, and MIROC5 performed simulations for the period 1960–2100 under the Representative Concentration Pathway RCP8.5 scenario to compute 20 year moving averages at 5-year increments. These were used to drive a crop suitability model, Ecocrop, for eight different crops across the three Food and Agriculture Organizations (FAO) AgroEcological Zones (AEZs) of West Africa (Guinea, Sahel, and Savanna). Simulations using historical climate data found that all crops except maize had a suitability index value (SIV) ≥0.50 outside the Sahel region, equivalent to conditions being suitable or strongly suitable. Simulations of future climate reveal that warming is projected to constrain crop growth suitability for cassava and pineapple in the Guinea zone. A potential for the northward expansion of maize is projected by the end of the century, suggesting a future opportunity for its growth in the southern Sahel zone. Crop growth conditions for mango and pearl millet remain suitable across all three AEZs. In general, crops in the Savanna AEZ are the most sensitive to the projected changes in climate. The changes in the crop–climate relationship suggests a future constraint in crop suitability, which could be detrimental to future food security in West Africa. Further studies to explore associated short- and long-term adaptation options are recommended.
Mechanical Properties and Oxidation Behavior of Cr–Si–N Coatings
Authors: Chang Li-Chun , Liu Yu-Heng , Chen Yung-I
Published: August 2019

Cr–Si–N coatings were prepared through reactive direct current magneton sputtering using a high N2/Ar flow ratio of 1. The addition of Si to improve the mechanical properties and oxidation resistance of Cr–N coatings was examined. The results indicated that the Cr–Si–N coatings with an Si content of <12 at % and an N content of >50 at % exhibited a cubic CrN phase with a columnar structure, whereas the coatings with 14 at % Si comprised of a nanocomposite structure, and the coatings with 16–18 at % Si were near-amorphous. The nanocomposite Cr32Si14N54 coating possessed hardness and Young’s modulus values of 17 and 209 GPa, respectively, accompanied with a hardness to effective Young’s modulus (H/E*) value of 0.077 and an elastic recovery (We) level of 55%—all the properties were highest within the as-deposited coating. The addition of Si was also beneficial to reduce the surface roughness and improve the oxidation resistance.
Construction and Performance Analysis of Image Steganography-Based Botnet in KakaoTalk Openchat
Authors: Jeon Jaewoo , Cho Youngho
Published: August 2019

Once a botnet is constructed over the network, a bot master and bots start communicating by periodically exchanging messages, which is known as botnet C&C communication, in order to send botnet commands to bots, collect critical information stored in bots, upgrade software functions of malwares installed in bots, and so on. For this reason, most existing botnet detection techniques focus on monitoring and capturing suspicious communications between the bot master and bots. Meanwhile, botnets continue to evolve to hide their C&C communication. Recently, a novel type of botnet using image steganography techniques and SNS (Social Network Service) platforms, which is known as image steganography-based botnet or stegobotnet, has emerged to make its C&C communications undetectable by existing botnet detection systems. In stegobotnets, image files used in SNSs carry messages (between the bot master and bots) which are hidden in them by using image steganography techniques. In this paper, we first investigate whether major SNS platforms such as KakaoTalk, Facebook, and Twitter can be suitable for constructing image steganography-based botnets. Next, we construct a part of stegobotnet based on KakaoTalk, and conduct extensive experiments including digital forensic analysis (1) to validate stegobotnet C&C communication can be successful in KakaoTalk and (2) to examine its performance in terms of C&C communication reliability.
Combining Nanofocused X-Rays with Electrical Measurements at the NanoMAX Beamline
Authors: Chayanun Lert , Hammarberg Susanna , Dierks Hanna , Otnes Gaute , Björling Alexander , Borgström Magnus T , Wallentin Jesper
Published: August 2019

The advent of nanofocused X-ray beams has allowed the study of single nanocrystals and complete nanoscale devices in a nondestructive manner, using techniques such as scanning transmission X-ray microscopy (STXM), X-ray fluorescence (XRF) and X-ray diffraction (XRD). Further insight into semiconductor devices can be achieved by combining these techniques with simultaneous electrical measurements. Here, we present a system for electrical biasing and current measurement of single nanostructure devices, which has been developed for the NanoMAX beamline at the fourth-generation synchrotron, MAX IV, Sweden. The system was tested on single InP nanowire devices. The mechanical stability was sufficient to collect scanning XRD and XRF maps with a 50 nm diameter focus. The dark noise of the current measurement system was about 3 fA, which allowed fly scan measurements of X-ray beam induced current (XBIC) in single nanowire devices.
Utilization of a CO2 Storage Material: Shape-Controlled Preparation of CaCO3 Microspheres
Authors: Meng Xianlong , Zhao Long , Guo Haitao , Sha Feng , Shi Huihu , Wu Zhaojun , Zhang Jianbin
Published: August 2019

Homogeneous CaCO3 microspheres were controllably synthesized via a simple hydrothermal method without using extraneous additives by Ca(OH)2 saturated solution reacted with CO2 storage material (CO2SM), which was obtained by absorbing CO2 gas in a system containing equimolar ethylenediamine (EDA) and polyethylene glycol 400 (PEG). Specifically, homogeneous pure vaterite spheres were obtained by using 160 g/L CO2SM solution at 100 °C and a reaction time of two hours. It is noteworthy that the EDA and PEG, which are released from CO2SM, have dual functions as a CO2 absorber and crystal regulator in the process of controlling the crystallization of CaCO3 crystals.
Application of Artificial Intelligence in the Detection and Differentiation of Colon Polyps: A Technical Review for Physicians
Authors: Chao Wei-Lun , Manickavasagan Hanisha , Krishna Somashekar G.
Published: August 2019

Research in computer-aided diagnosis (CAD) and the application of artificial intelligence (AI) in the endoscopic evaluation of the gastrointestinal tract is novel. Since colonoscopy and detection of polyps can decrease the risk of colon cancer, it is recommended by multiple national and international societies. However, the procedure of colonoscopy is performed by humans where there are significant interoperator and interpatient variations, and hence, the risk of missing detection of adenomatous polyps. Early studies involving CAD and AI for the detection and differentiation of polyps show great promise. In this appraisal, we review existing scientific aspects of AI in CAD of colon polyps and discuss the pitfalls and future directions for advancing the science. This review addresses the technical intricacies in a manner that physicians can comprehend to promote a better understanding of this novel application.
Design and Benchmark Testing for Open Architecture Reconfigurable Mobile Spirometer and Exhaled Breath Monitor with GPS and Data Telemetry
Authors: Fung Alexander G. , Tan Laren D. , Duong Theresa N. , Schivo Michael , Littlefield Leslie , Delplanque Jean Pierre , Davis Cristina E. , Kenyon Nicholas J.
Published: August 2019

Portable and wearable medical instruments are poised to play an increasingly important role in health monitoring. Mobile spirometers are available commercially, and are used to monitor patients with advanced lung disease. However, these commercial monitors have a fixed product architecture determined by the manufacturer, and researchers cannot easily experiment with new configurations or add additional novel sensors over time. Spirometry combined with exhaled breath metabolite monitoring has the potential to transform healthcare and improve clinical management strategies. This research provides an updated design and benchmark testing for a flexible, portable, open access architecture to measure lung function, using common Arduino/Android microcontroller technologies. To demonstrate the feasibility and the proof-of-concept of this easily-adaptable platform technology, we had 43 subjects (healthy, and those with lung diseases) perform three spirometry maneuvers using our reconfigurable device and an office-based commercial spirometer. We found that our system compared favorably with the traditional spirometer, with high accuracy and agreement for forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC), and gas measurements were feasible. This provides an adaptable/reconfigurable open access “personalized medicine” platform for researchers and patients, and new chemical sensors and other modular instrumentation can extend the flexibility of the device in the future.
Some New Results on the Gaussian Wiretap Feedback Channel
Authors: Wei Chenxu , Yu Linman , Dai Bin
Published: August 2019

In this paper, the Gaussian wiretap feedback channel is revisited, and some new results on its secrecy capacity are obtained. To be specific, first, we show that the Schalkwijk–Kailath (SK) feedback scheme, which achieves the secrecy capacity of the degraded Gaussian wiretap feedback channel, also achieves the secrecy capacity of the non-degraded Gaussian wiretap feedback channel. Second, applying the existing secret key-based feedback schemes to Gaussian wiretap feedback channels, we derive some new lower bounds on the secrecy capacities of these models. Finally, we compare the performances of the above feedback schemes in the degraded and non-degraded Gaussian wiretap feedback channels and show which feedback scheme performs better for these channel models.
Unemployment and Growth in the Tourism Sector in Mexico: Revisiting the Growth-Rate Version of Okun’s Law
Authors: Sánchez López Fernando
Published: August 2019

In this paper, we analyze, by means of the difference version of Okun’s law, the relationship between tourism sector growth and unemployment in Mexico during the period 2000Q2–2018Q4. The results show that tourism growth is a palliative for unemployment, whereas unemployment reduces the growth of the tourism sector. The results also show that the relationship between the mentioned variables becomes stronger during an economic crisis and weaker during expansion periods.
Fallen People Detection Capabilities Using Assistive Robot
Authors: Maldonado-Bascón Saturnino , Iglesias-Iglesias Cristian , Martín-Martín Pilar , Lafuente-Arroyo Sergio
Published: August 2019

One of the main problems in the elderly population and for people with functional disabilities is falling when they are not supervised. Therefore, there is a need for monitoring systems with fall detection functionality. Mobile robots are a good solution for keeping the person in sight when compared to static-view sensors. Mobile-patrol robots can be used for a group of people and systems are less intrusive than ones based on mobile robots. In this paper, we propose a novel vision-based solution for fall detection based on a mobile-patrol robot that can correct its position in case of doubt. The overall approach can be formulated as an end-to-end solution based on two stages: person detection and fall classification. Deep learning-based computer vision is used for person detection and fall classification is done by using a learning-based Support Vector Machine (SVM) classifier. This approach mainly fulfills the following design requirements—simple to apply, adaptable, high performance, independent of person size, clothes, or the environment, low cost and real-time computing. Important to highlight is the ability to distinguish between a simple resting position and a real fall scene. One of the main contributions of this paper is the input feature vector to the SVM-based classifier. We evaluated the robustness of the approach using a realistic public dataset proposed in this paper called the Fallen Person Dataset (FPDS), with 2062 images and 1072 falls. The results obtained from different experiments indicate that the system has a high success rate in fall classification (precision of 100% and recall of 99.74%). Training the algorithm using our Fallen Person Dataset (FPDS) and testing it with other datasets showed that the algorithm is independent of the camera setup.
An On-Glass Optically Transparent Monopole Antenna with Ultrawide Bandwidth for Solar Energy Harvesting
Authors: Cai Longzhu
Published: August 2019

An on-glass optically transparent monopole antenna with ultrawide bandwidth is presented in this work, and the proposed antenna is of ring shape and coplanar waveguide fed structure. Optically transparent indium tin oxide (ITO) thin film with a thickness of ~ 160   nm is used as the conductive layer, which is sputtered on an optically transparent glass substrate. An impedance bandwidth of 6 GHz from 1 to 7 GHz is achieved, with a return loss lower than −10 dB, meaning a fractional bandwidth of 150%. The proposed antenna exhibits reasonable radiations of omni-directionality in the H plane and bi-directionality in the E plane. Like other transparent antennas discussed in literature, the antenna gain is relatively low (−4 dBi at 5 GHz). In order to optimize the antenna performance, multi-film approach is proposed to reduce its sheet resistance, and the result shows that the antenna gain at 4 GHz can be improved from −8 dBi to 5 dBi when optimizing the sheet resistance from 10   Ω / sq to 0.01   Ω / sq . The designed antenna possesses a high optical transparency, which makes it easy to integrate to the surface of windows or display panels, and it can be applied for solar energy harvesting and many other ultra-wideband applications, with little chance of detection.
Impact of Component Dispersion in DC to DC Low-Power Low-Voltage Power Converter Array
Authors: Crebier Jean-Christophe , Lamorelle Theo , Marache Silvain , Phung Thanh Hai , Nguyen Van-Sang , Andreta Andre , Podvin Jean Christophe , Lembeye Yves
Published: August 2019

The paper deals with arrays of numerous power conversion cells, associated in series and/or in parallel to build larger step up or step down direct current (DC)/DC isolated converters. The work focuses on the impact of the spread and distribution of the conversion cell characteristics on the characteristics and performance of the power converter array (PCA). Based on a characterization protocol, about 130 conversion standard cells (CSC) are characterized and classified from a statistical point of view. Three families are defined and representatives are chosen and implemented in various configurations, in open and closed loop control, to analyze the impact of their spread characteristic over the global converter, the PCA. The paper is based on an extended practical set up and protocols, all described in details. Guidelines on CSCs implementation with respect to their dispersion are provided at the end on the paper.
Numerical Study of Variable Camber Continuous Trailing Edge Flap at Off-Design Conditions
Authors: Raheem Mohammed Abdul , Edi Prasetyo , Pasha Amjad A. , Rahman Mustafa M. , A. Juhany Khalid
Published: August 2019

Numerical simulations are performed to study the outboard airfoil of advanced technology regional aircraft (ATRA) wings with five different variable camber continuous trailing edge flap (VCCTEF) configurations. The computational study aims to improve the aerodynamic efficiency of the airfoil under cruise conditions. The design of outboard airfoil complies with the hybrid laminar flow control design criteria. This work is unique in terms of analysis of the effects of VCCTEF on the ATRA wing’s outboard airfoil during the off-design condition. The Reynolds–Averaged Navier–Stokes equations coupled with the Spalart-Allmaras turbulence model are employed to perform the simulations for the baseline case and VCCTEF configurations. The current computational study is performed at an altitude of 10 km with a cruise Mach number of 0.77 and a Reynolds number of 2.16 × 107. Amongst all five configurations of VCCTEF airfoils studied, a flap having a parabolic profile (VCCTEF 123) configuration shows the maximum airfoil efficiency and resulted in an increase of 6.3% as compared to the baseline airfoil.
Electromechanical Analysis of the Medium Voltage Earthing Switch due to Short-Time and Peak Withstand Current Test
Authors: Krčum Maja , Zubčić Marko , Dlabač Tatijana
Published: August 2019

The chosen electrical equipment, i.e., the earthing switch has its application in marine switchgear. In this paper, the reduction of dimensions is considered with the purpose of making it more energy efficient in terms of onboard application. This test validates that the earthing switch as an electromechanical device is capable of withstanding electrodynamic forces. Two approaches are applied and compared. Both approaches are based on a simplified three-dimensional (3D) model of the earthing switch. The first approach is analytical: the electrodynamic forces are calculated with the assumption that currents flow in concentrated lines. Maximum static stress is compared to the yield point of the earthing knife material. The second approach applies the finite element method in the time domain. The results show that the rectangular cross-section can withstand the electrodynamic forces produced by the given currents. Simple cost analysis shows how much material is saved by changing the design from standard earthing knifes with C channel profile to the rectangular profile. Material savings make this study interesting for marine switchgear application. The paper shows qualitative influence of the obtained results on the Energy Efficiency Design Index of the ships.
Impact of Electrical Topology, Capacity Factor and Line Length on Economic Performance of Offshore Wind Investments
Authors: Kucuksari Sadik , Erdogan Nuh , Cali Umit
Published: August 2019

In this study, an economic performance assessment of offshore wind investments is investigated through electrical topology, capacity factor and line length. First, annual energy yield production and electrical system losses for AC and DC offshore wind configurations are estimated by using Weibull probability distributions of wind speed. A cost model for calculating core energy economic metrics for offshore wind environment is developed by using a discount cash flow analysis. A case study is then conducted for a projected offshore wind farm (OWF) rated 100 MW and 300 MW sizes situated in the Aegean sea. Finally, a sensitivity analysis is performed for AC and DC OWFs with three different capacity factors (e.g., 45%, 55% and 60%) and various transmission line lengths ranging from 20 km to 120 km. The OWF is found to be economically viable for both AC and DC configurations with the estimated levelized cost of electricity (LCOE) ranging from 88.34 $/MWh to 113.76 $/MWh and from 97.61 $/MWh to 126.60 $/MWh, respectively. LCOEs for both options slightly change even though the wind farm size was increased three-fold. The sensitivity analysis reveals that, for further offshore locations with higher capacity factors, the superiority of AC configuration over the DC option in terms of LCOE reduces while the advantage of DC configuration over the AC option in terms of electrical losses is significant. Losses in the AC and DC configurations range from 3.75% to 5.86% and 3.75% to 5.34%, respectively, while LCOEs vary between 59.90 $/MWh and 113.76 $/MWh for the AC configuration and 66.21 $/MWh and 124.15 $/MWh for the DC configuration. Capacity factor was found to be more sensitive in LCOE estimation compared to transmission line length while line length is more sensitive in losses estimation compared to capacity factor.
Utilization of Petroleum Coke Soot as Energy Storage Material
Authors: Lee Won-Ju , Kim Dae-Young , Choi Jae-Hyuk , Lee Ji-Woong , Kim Jun-Soo , Son Kwangho , Ha Min-Jae , Kang Jun
Published: August 2019

Anode active materials for lithium ion batteries (LIBs) were produced by using waste soot generated after combustion in a plant using petroleum coke as fuel. The soot collected from the boilers in the plant was graphitized through annealing, and this annealed soot was applied to anode active materials. After annealing at 2700 °C, the soot was converted into highly crystalline graphite with ring shapes approximately 100 nm in diameter. The lithium ion coin cells produced using graphitized soot showed high discharge capacity and excellent life cycle with a reversible capacity of 250 mAh/g even after 300 cycles at a rate of 1 C. This study describes a new possibility of using environmentally harmful combustion wastes of petroleum coke as a low-price anode material for LIBs by converting them into a graphite multilayer structure with a unique ring shape through annealing.
Optimal Stator Design of Doubly Salient Permanent Magnet Generator for Enhancing the Electromagnetic Performance
Authors: Lounthavong Vannakone , Sriwannarat Warat , Siritaratiwat Apirat , Khunkitti Pirat
Published: August 2019

An optimal stator design technique of a three-phase doubly salient permanent magnet generator (DSPMG) for improving the output power is proposed. The stator configuration was optimally designed by adjusting the stator pole depth and stator pole arc. The trapezoid outer stator tip was also designed. Then, the output characteristics of the designed DSPMG including the flux linkage, electromotive force (EMF), harmonic, cogging torque, efficiency, magnetic flux distribution and voltage regulation were characterized by using the finite element method. Results were compared to the original structure in the literature. It was found that the flux linkage, EMF, cogging torque, and efficiency of the proposed DSPMG were significantly improved after the stator pole depth and stator pole arc were suitably modified. Further details of optimal stator pole depth and stator pole arc are presented. The EMF produced by the optimal proposed structure was 47% higher than that of the conventional structure, while 56% cogging torque improvement and 20% increased efficiency were achieved. The EMF generated by the proposed structure was classified in the high-range scale compared to the other existing models. The symmetrical magnetic flux distribution of all structures was indicated. The voltage regulation of the modified structure was also significantly improved from the conventional model. The proposed design technique can be utilized to maximize the electromagnetic performance of this particular generator type.
Quantifying the Opportunity Limits of Automatic Residential Electric Load Shaping
Authors: Cruickshank Robert , Henze Gregor , Balaji Rajagopalan , Hodge Bri-Mathias , Florita Anthony
Published: August 2019

Electric utility residential demand response programs typically reduce load a few times a year during periods of peak energy use. In the future, utilities and consumers may monetarily and environmentally benefit from continuously shaping load by alternatively encouraging or discouraging the use of electricity. One way to shape load and introduce elasticity is to broadcast forecasts of dynamic electricity prices that orchestrate electricity supply and demand in order to maximize the efficiency of conventional generation and the use of renewable resources including wind and solar energy. A binary control algorithm that influences the on and off states of end uses was developed and applied to empirical time series data to estimate price-based instantaneous opportunities for shedding and adding electric load. To overcome the limitations of traditional stochastic methods in quantifying diverse, non-Gaussian, non-stationary distributions of observed appliance behaviour, recent developments in wavelet-based analysis were applied to capture and simulate time-frequency domain behaviour. The performance of autoregressive and spectral reconstruction methods was compared, with phase reconstruction providing the best simulation ensembles. Results show spatiotemporal differences in the amount of load that can be shed and added, which suggest further investigation is warranted in estimating the benefits anticipated from the wide-scale deployment of continuous automatic residential load shaping. Empirical data and documented software code are included to assist in reproducing and extending this work.
Three-Dimensional Inverse Design Method for Hydraulic Machinery
Authors: Yang Wei , Liu Benqing , Xiao Ruofu
Published: August 2019

Hydraulic machinery with high performance is of great significance for energy saving. Its design is a very challenging job for designers, and the inverse design method is a competitive way to do the job. The three-dimensional inverse design method and its applications to hydraulic machinery are herein reviewed. The flow is calculated based on potential flow theory, and the blade shape is calculated based on flow-tangency condition according to the calculated flow velocity. We also explain flow control theory by suppression of secondary flow and cavitation based on careful tailoring of the blade loading distribution and stacking condition in the inverse design of hydraulic machinery. Suggestions about the main challenge and future prospective of the inverse design method are given.