bluuebunny/crossref_metadata_2025 huggingface dataset:
Ability to Glue Portuguese Eucalyptus Elements
Authors: Suleimana Aiuba , Sena Caroline S. , Branco Jorge M. , Camões Aires
Published: July 2020

Portuguese forests have changed in recent years. These changes were mainly boosted by the wildfires that affected a significant percentage of the softwood area. Eucalyptus is actually the dominant wood species in Portuguese forests. This is not a native hardwood, but is being planted mainly for pulp and paper production, and its availability and mechanical performance have made it very present in timber construction in the last 50 years. Within the discussion to substitute imported raw materials, mainly from softwoods, with local hardwoods for the production of engineered wood products, the study of the ability to glue eucalyptus has become a necessity. This paper presents experimental works aimed to assess the ability to glue eucalyptus elements for the production of glued laminated timber (GLT) and cross-laminated timber (CLT). Since this wood species has been known for being difficult to dry, a preliminary study on the dimensional stability under moisture content variation was performed. Then, shear strength tests were made in accordance with ASTM D143. The objective was to correlate those results with the tests performed in the following research step. In this further stage, shear strength tests of the bond line were performed following EN 14080 and EN 16351. The results obtained in all the experiments show that eucalyptus has the potential to be glued and therefore the production of GLT and/or CLT using this local undervalued wood species is potentially of high industrial interest.
Nivolumab plus Ipilimumab versus Existing Immunotherapies in Patients with PD-L1-Positive Advanced Non-Small Cell Lung Cancer: A Systematic Review and Network Meta-Analysis
Authors: Ando Koichi , Kishino Yasunari , Homma Tetsuya , Kusumoto Sojiro , Yamaoka Toshimitsu , Tanaka Akihiko , Ohmori Tohru , Ohnishi Tsukasa , Sagara Hironori
Published: July 2020

No head-to-head trials have compared the efficacy and safety of nivolumab (Niv) plus ipilimumab (Ipi) combination therapy (Niv+Ipi) and existing regimens with immunotherapies approved as first-line treatment in patients with programmed cell death ligand 1 (PD-L1)-positive previously untreated advanced non-small cell lung cancer (NSCLC). We conducted a network meta-analysis of four relevant Phase Ⅲ trials to compare the efficacy and safety of Niv+Ipi, pembrolizumab (Pem) plus platinum-based chemotherapy (PBC) (Pem+PBC), Pem, Niv, or PBC using Bayesian analysis. The primary efficacy endpoint was progression-free survival (PFS) in patients with advanced NSCLC with PD-L1 expression ≥1%. The primary safety endpoint was the incidence of Grade 3–5 drug-related adverse events (G3–5AEs). Efficacy and safety were ranked using surface under the cumulative ranking curve (SUCRA). With regard to PFS, Niv+Ipi was inferior to Pem+PBC, and superior to Pem, Niv, or PBC alone. SUCRA ranking showed Pem+PBC had the highest efficacy for PFS, followed by Niv+Ipi, Niv, PBC, and Pem. The safety outcome analysis revealed Niv+Ipi was generally well tolerated compared to existing immunotherapy regimens. These results provide clinical information regarding the efficacy and safety of Niv+Ipi and indicate the possibility of the Niv+Ipi combination as a new therapeutic option in PD-L1-positive advanced NSCLC.
The Activity of KIF14, Mieap, and EZR in a New Type of the Invasive Component, Torpedo-Like Structures, Predetermines the Metastatic Potential of Breast Cancer
Authors: Gerashchenko Tatiana S. , Zolotaryova Sofia Y. , Kiselev Artem M. , Tashireva Liubov A. , Novikov Nikita M. , Krakhmal Nadezhda V. , Cherdyntseva Nadezhda V. , Zavyalova Marina V. , Perelmuter Vladimir M. , Denisov Evgeny V.
Published: July 2020

Intratumor morphological heterogeneity reflects patterns of invasive growth and is an indicator of the metastatic potential of breast cancer. In this study, we used this heterogeneity to identify molecules associated with breast cancer invasion and metastasis. The gene expression microarray data were used to identify genes differentially expressed between solid, trabecular, and other morphological arrangements of tumor cells. Immunohistochemistry was applied to evaluate the association of the selected proteins with metastasis. RNA-sequencing was performed to analyze the molecular makeup of metastatic tumor cells. High frequency of metastases and decreased metastasis-free survival were detected in patients either with positive expression of KIF14 or Mieap or negative expression of EZR at the tips of the torpedo-like structures in breast cancers. KIF14- and Mieap-positive and EZR-negative cells were mainly detected in the torpedo-like structures of the same breast tumors; however, their transcriptomic features differed. KIF14-positive cells showed a significant upregulation of genes involved in ether lipid metabolism. Mieap-positive cells were enriched in genes involved in mitophagy. EZR-negative cells displayed upregulated genes associated with phagocytosis and the chemokine-mediated signaling pathway. In conclusion, the positive expression of KIF14 and Mieap and negative expression of EZR at the tips of the torpedo-like structures are associated with breast cancer metastasis.
Integrin Crosstalk Contributes to the Complexity of Signalling and Unpredictable Cancer Cell Fates
Authors: Samaržija Ivana , Dekanić Ana , Humphries Jonathan D. , Paradžik Mladen , Stojanović Nikolina , Humphries Martin J. , Ambriović-Ristov Andreja
Published: July 2020

Integrins are heterodimeric cell surface receptors composed of α and β subunits that control adhesion, proliferation and gene expression. The integrin heterodimer binding to ligand reorganises the cytoskeletal networks and triggers multiple signalling pathways that can cause changes in cell cycle, proliferation, differentiation, survival and motility. In addition, integrins have been identified as targets for many different diseases, including cancer. Integrin crosstalk is a mechanism by which a change in the expression of a certain integrin subunit or the activation of an integrin heterodimer may interfere with the expression and/or activation of other integrin subunit(s) in the very same cell. Here, we review the evidence for integrin crosstalk in a range of cellular systems, with a particular emphasis on cancer. We describe the molecular mechanisms of integrin crosstalk, the effects of cell fate determination, and the contribution of crosstalk to therapeutic outcomes. Our intention is to raise awareness of integrin crosstalk events such that the contribution of the phenomenon can be taken into account when researching the biological or pathophysiological roles of integrins.
Role of ETS1 in the Transcriptional Network of Diffuse Large B Cell Lymphoma of the Activated B Cell-Like Type
Authors: Priebe Valdemar , Sartori Giulio , Napoli Sara , Chung Elaine Yee Lin , Cascione Luciano , Kwee Ivo , Arribas Alberto Jesus , Mensah Afua Adjeiwaa , Rinaldi Andrea , Ponzoni Maurilio , Zucca Emanuele , Rossi Davide , Efremov Dimitar , Lenz Georg , Thome Margot , Bertoni Francesco
Published: July 2020

Diffuse large B cell lymphoma (DLBCL) is a heterogenous disease that has been distinguished into at least two major molecular entities, the germinal center-like B cell (GCB) DLBCL and activated-like B cell (ABC) DLBCL, based on transcriptome expression profiling. A recurrent ch11q24.3 gain is observed in roughly a fourth of DLBCL cases resulting in the overexpression of two ETS transcription factor family members, ETS1 and FLI1. Here, we knocked down ETS1 expression by siRNA and analyzed expression changes integrating them with ChIP-seq data to identify genes directly regulated by ETS1. ETS1 silencing affected expression of genes involved in B cell signaling activation, B cell differentiation, cell cycle, and immune processes. Integration of RNA-Seq (RNA sequencing) data and ChIP-Seq (chromatin immunoprecipitation sequencing) identified 97 genes as bona fide, positively regulated direct targets of ETS1 in ABC-DLBCL. Among these was the Fc receptor for IgM, FCMR (also known as FAIM3 or Toso), which showed higher expression in ABC- than GCB-DLBCL clinical specimens. These findings show that ETS1 is contributing to the lymphomagenesis in a subset of DLBCL and identifies FCMR as a novel target of ETS1, predominantly expressed in ABC-DLBCL.
Rescue of Non-Informative Circulating Tumor DNA to Monitor the Mutational Landscape in NSCLC
Authors: Mayer Stefanie , Schmidtke-Schrezenmeier Gerlinde , Buske Christian , Rücker Frank G. , Barth Thomas F.E. , Möller Peter , Marienfeld Ralf
Published: July 2020

In non-small cell lung cancer (NSCLC) the usage of plasma-derived circulating tumor DNA (ctDNA) have come into focus to obtain a comprehensive genetic profile of a given lung cancer. Despite the usage of specific sampling tubes, archived plasma samples as well as inappropriately treated blood samples still cause a loss of information due to cell lysis and contamination with cellular DNA. Our aim was to establish a reliable protocol to rescue ctDNA from such non-informative samples to monitor the mutational landscape in NSCLC. As a proof-of-concept study we used archived plasma samples derived from whole blood EDTA samples of 51 patients suffering from NSCLC. Analysis of the isolated plasma DNA determined only a small fraction of ctDNA in a range of 90–250 bp. By applying a specific purification procedure, we were able to increase the informative ctDNA content and improve in a cohort of 42 patients the detection of driver mutations from 32% to 79% of the mutations found in tissue biopsies. Thus, we present here an easy to perform, time and cost effective procedure to rescue non-informative ctDNA samples, which is sufficient to detect oncogenic mutations in NGS approaches and is therefore a valuable technical improvement for laboratories handling liquid biopsy samples.
A Pd/MnO2 Electrocatalyst for Nitrogen Reduction to Ammonia under Ambient Conditions
Authors: Sun Chang , Mu Yingxin , Wang Yuxin
Published: July 2020

Electrochemical ammonia synthesis, which is an alternative approach to the Haber–Bosch process, has attracted the attention of researchers because of its advantages including mild working conditions, environmental protection, and simple process. However, the biggest problem in this field is the lack of high-performance catalysts. Here, we report high-efficiency electroreduction of N2 to NH3 on γ-MnO2-supported Pd nanoparticles (Pd/γ-MnO2) under ambient conditions, which exhibits excellent catalytic activity with an NH3 yield rate of 19.72 μg·mg−1Pd h−1 and a Faradaic efficiency of 8.4% at −0.05 V vs. the reversible hydrogen electrode (RHE). X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterization shows that Pd nanoparticles are homogeneously dispersed on the γ-MnO2. Pd/γ-MnO2 outperforms other catalysts including Pd/C and γ-MnO2 because of its synergistic catalytic effect between Pd and Mn.
In-Exchanged CHA Zeolites for Selective Dehydrogenation of Ethane: Characterization and Effect of Zeolite Framework Type
Authors: Maeno Zen , Wu Xiaopeng , Yasumura Shunsaku , Toyao Takashi , Kanda Yasuharu , Shimizu Ken-ichi
Published: July 2020

In this study, the characterization of In-exchanged CHA zeolite (In-CHA (SiO2/Al2O3 = 22.3)) was conducted by in-situ X-ray diffraction (XRD) and ammonia temperature-programmed desorption (NH3-TPD). We also prepared other In-exchanged zeolites with different zeolite structures (In-MFI (SiO2/Al2O3 = 22.3), In-MOR (SiO2/Al2O3 = 20), and In-BEA (SiO2/Al2O3 = 25)) and different SiO2/Al2O3 ratios (In-CHA(Al-rich) (SiO2/Al2O3 = 13.7)). Their catalytic activities in nonoxidative ethane dehydrogenation were compared. Among the tested catalysts, In-CHA(Al-rich) provided the highest conversion. From kinetic experiments and in-situ Fourier transform infrared (FTIR) spectroscopy, [InH2]+ ions are formed regardless of SiO2/Al2O3 ratio, serving as the active sites.
Green Solid-State Chemical Reduction of Graphene Oxide Supported on a Paper Substrate
Authors: Longo Angela , Palomba Mariano , Carotenuto Gianfranco
Published: July 2020

The reduction of graphene oxide (GO) thin films deposited on substrates is crucial to achieve a technologically useful supported graphene material. However, the well-known thermal reduction process cannot be used with thermally unstable substrates (e.g., plastics and paper), in addition photo-reduction methods are expensive and only capable of reducing the external surface. Therefore, solid-state chemical reduction techniques could become a convenient approach for the full thickness reduction of the GO layers supported on thermally unstable substrates. Here, a novel experimental procedure for quantitative reduction of GO films on paper by a green and low-cost chemical reductant (L-ascorbic acid, L-aa) is proposed. The possibility to have an effective mass transport of the reductant inside the swelled GO solid (gel-phase) deposit was ensured by spraying a reductant solution on the GO film and allowing it to reflux in a closed microenvironment at 50 °C. The GO conversion degree to reduced graphene oxide (r-GO) was evaluated by Fourier transform infrared spectroscopy (FT-IR) in attenuated total reflectance (ATR) mode and X-ray Diffraction (XRD). In addition, morphology and wettability of GO deposits, before and after reduction, were confirmed by digital USB microscopy, scanning electron microscopy (SEM), and contact angle measurements. According to these structural characterizations, the proposed method allows a bulky reduction of the coating but leaves to a GO layer at the interface, that is essential for a good coating-substrate adhesion and this special characteristic is useful for industrial exploitation of the material.
Research Progress of High Dielectric Constant Zirconia-Based Materials for Gate Dielectric Application
Authors: Xie Junan , Zhu Zhennan , Tao Hong , Zhou Shangxiong , Liang Zhihao , Li Zhihang , Yao Rihui , Wang Yiping , Ning Honglong , Peng Junbiao
Published: July 2020

The high dielectric constant ZrO2, as one of the most promising gate dielectric materials for next generation semiconductor device, is expected to be introduced as a new high k dielectric layer to replace the traditional SiO2 gate dielectric. The electrical properties of ZrO2 films prepared by various deposition methods and the main methods to improve their electrical properties are introduced, including doping of nonmetal elements, metal doping design of pseudo-binary alloy system, new stacking structure, coupling with organic materials and utilization of crystalline ZrO2 as well as optimization of low-temperature solution process. The applications of ZrO2 and its composite thin film materials in metal oxide semiconductor field effect transistor (MOSFET) and thin film transistors (TFTs) with low power consumption and high performance are prospected.
Precipitation Hardening of the HVOF Sprayed Single-Phase High-Entropy Alloy CrFeCoNi
Authors: Löbel Martin , Lindner Thomas , Hunger Ralph , Berger Robin , Lampke Thomas
Published: July 2020

The application of high-entropy alloys (HEA) in surface technology has great potential due to the high corrosion and wear resistance. A further improvement can be achieved by applying thermochemical treatments. Powder-pack boriding enables the formation of a protective precipitation layer. This process has already been applied for cast HEAs causing the formation of a diffusion-enriched surface layer and a distinct increase in wear resistance. In the current investigations, the alloy CrFeCoNi with a single-phase face-centred cubic (fcc) structure is considered. An efficient application can be achieved by limiting the material usage of HEAs to the surface. Therefore, the high-velocity-oxygen-fuel (HVOF) thermal spray process is applied. Boriding was conducted with an adapted powder-pack routine. Furthermore, borided bulk HEAs were considered as a reference. The influence of the production route and boriding treatment on the microstructure, phase formation, and properties was investigated in detail. For the coating and the cast HEA, a precipitation layer is formed. Hence, the hardness and wear resistance are significantly increased. The current study proves the suitability of the investigated process combination.
Comparison of the Microstructure Evolution and Wear Resistance of Ti6Al4V Composite Coatings Reinforced by Hard Pure or Ni-plated Cubic Boron Nitride Particles Prepared with Laser Cladding on a Ti6Al4V Substrate
Authors: Fu Shuren , Yang Lijing , Wang Pei , Wang Shaopeng , Li Zhengxian
Published: July 2020

Titanium alloy is a major structural material with excellent high specific strength in aerospace applications. Cubic boron nitride (cBN) is a synthetic wear-resistant material with high hardness, similar to that of diamond, that is used in mechanical cutting and grinding. In addition, the thermal stability of cubic boron nitride particles is much better than that of diamond. In order to further enhance the wear resistance of the Ti6Al4V alloy, the laser cladding (LC) technology characteristics of metallurgical bonding were used to prepare cubic boron nitride/Ti6Al4V and Ni-plated cubic boron nitride/Ti6Al4V composite coatings on Ti6Al4V substrates in this paper. However, in the laser molten pool, it is difficult to retain the raw properties of cubic boron nitride particles under laser radiation. Both composite coatings were analyzed using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The microstructures and interface bonding between cubic boron nitride particles and the Ti6Al4V matrix were examined using SEM, and the wear resistance and the worn track morphology of the composite coatings were evaluated using the ball-on-disc wear test and step profiler (WTM-2E). The results indicated that the Ni-plated cubic boron nitride/Ti6Al4V composite coating showed fewer thermal defects in comparison with the cubic boron nitride/Ti6Al4V coating. The Ni plating on the surface of cubic boron nitride particles was able to avoid the generation of thermal cracking of the cubic boron nitride particles in the composite coating. The TiN reaction layer was formed between the cubic boron nitride particles and Ti6Al4V matrix, which effectively prevented the further decomposition of the cubic boron nitride particles. The XRD and XPS results confirmed that the TiN reaction layer formed between the cubic boron nitride particles and Ti6Al4V. The Ni plating on the surface of the cubic boron nitride particles was also beneficial for increasing the wear resistance of the composite coating.
ERF: An Empirical Recommender Framework for Ascertaining Appropriate Learning Materials from Stack Overflow Discussions
Authors: Iqbal Ashesh , Khatun Sumi , Arefin Mohammad Shamsul , Dewan M. Ali Akber
Published: July 2020

Computer programmers require various instructive information during coding and development. Such information is dispersed in different sources like language documentation, wikis, and forums. As an information exchange platform, programmers broadly utilize Stack Overflow, a Web-based Question Answering site. In this paper, we propose a recommender system which uses a supervised machine learning approach to investigate Stack Overflow posts to present instructive information for the programmers. This might be helpful for the programmers to solve programming problems that they confront with in their daily life. We analyzed posts related to two most popular programming languages—Python and PHP. We performed a few trials and found that the supervised approach could effectively manifold valuable information from our corpus. We validated the performance of our system from human perception which showed an accuracy of 71%. We also presented an interactive interface for the users that satisfied the users’ query with the matching sentences with most instructive information.
Endemism of Uropodina Mites: Spurious or Real?
Authors: Błoszyk Jerzy , Napierała Agnieszka
Published: July 2020

Analyzing the data from the existing literature about geographic distribution of mites from the suborder Uropodina (Acari: Mesostigmata), one can get the impression that this group of mites is characterized by an unusual extent of endemism on a global scale. This observation encouraged the authors of this study to ascertain whether endemism in Uropodina mites is a real feature of this group or whether it stems from the current state of affairs in this field of research. The study is based on evidence from the literature on the topic and data obtained from long-term research conducted on extensive materials from all over the globe (over 40,000 samples). The discussion presented in the article is supported by many examples, showing that both hypotheses can in fact be proved right. The major point of reference in this study is the fairly well-known fauna of Uropodina in Europe, whereas South America is the testing area for the two hypotheses.
Animal Models for Studying Stone Disease
Authors: Chen Szu-Ju , Chiu Kun-Yuan , Chen Huey-Yi , Lin Wei-Yong , Chen Yung-Hsiang , Chen Wen-Chi
Published: July 2020

Animals have stone disease too. There are several animal models for the research of human stone disease. Rodents are the most frequently used for stone research, although they are not prone to forming crystals in the kidneys. Ethylene glycol (EG), sodium oxalate and l-hydroxyproline are common lithogenic agents. Dogs and pigs were also reported as a study animal for stone disease. However, the breeding costs and body size are too high. The most-used genetic study animal for stone disease was the mouse, but it was high-cost. Calcium oxalate (CaOx) crystals can also be light microscopically observed in the Malphigian tubules of Drosophila melanogaster, induced by adding EG to the food. Genetic studies of flies can be done by cross-breeding, and this has a lower cost than using mice. The fly model also has several advantages, including minimal breeding equipment, the fact that it is easier to reach larger numbers in a short time with flies, that crystals can be observed under microscopy, and that they allow genetic study. We suggest the fly will be an ideal animal model for stone research in the future.
COLD-PCR Method for Early Detection of Antiviral Drug-Resistance Mutations in Treatment-Naive Children with Chronic Hepatitis B
Authors: Phung Thuy Thi Bich , Chu Son Van , Vu Son Thien , Pham Hanh Thi , Nguyen Hang Minh , Nguyen Hoan Dang , Le Ngan Thi , Nguyen Dung Van , Truong Phuong Thai , Vu Van Thi Tuong , Nguyen Anh Thi Van
Published: July 2020

We investigated Nucleos(t)ide-analogue (NA)-resistance mutations (mt) in 142 treatment-naive children with Chronic Hepatitis B (CHB), using a sensitive co-amplification at lower denaturation temperature (COLD)-PCR with Sanger DNA sequencing. An NA resistance-associated mt in the hepatitis B virus (HBV) reverse transcriptase (RT) was found in 66.2% of the patients, with nonclassical mt contributing the most (64.8%). Significantly higher frequencies of Lamivudine (LMV) and Adefovir dipivoxil (ADF) resistance-associated mt were found in genotypes B and C, respectively (ORLMV/ADF: 1495.000; 95% CI: 89.800–24,889.032; p < 0.001). Single-point mt associated to LMV and ADF resistance were detected in 59.9% of the tested children with rtV207M (38.0%) and rtN238T (9.9%) being the most frequent. Multiple-point mt were found only in 8 cases (5.6%): 6 children carried double mt (rtV207M + rtL229V; rtV207M + rtI233V; rtV207I + rtV207M × 2 cases; rtV207M + rtS213T; rtN238A + rtS256G) relating to LMV or/and ADF resistance and 3 children carried triple mt (rtL180M + rtM204I + rtN238T; rtV207M + rtS213T + rtS256G) or quadruple mt (rtL180M + rtM204V + rtV207I/M) for LMV-ADF resistance and Entecavir-reduced susceptibility. Our data indicate that significantly higher frequencies of LMV and ADF-associated mutations were found in treatment-naïve children infected with HBV genotypes B and C, respectively. The developed COLD-PCR method and obtained data may contribute to the development of suitable treatments for children with CHB.
COVID-19 Pneumonia: Three Thoracic Complications in the Same Patient
Authors: Borghesi Andrea , Aggiusti Carlo , Farina Davide , Maroldi Roberto , Muiesan Maria Lorenza
Published: July 2020

The most dreaded thoracic complications in patients with coronavirus disease 2019 (COVID-19) are acute pulmonary embolism and pulmonary fibrosis. Both the complications are associated with an increased risk of morbidity and mortality. While acute pulmonary embolism is not a rare finding in patients with COVID-19 pneumonia, the prevalence of pulmonary fibrosis remains unclear. Spontaneous pneumothorax is another possible complication in COVID-19 pneumonia, although its observation is rather uncommon. Herein, we present interesting computed tomography images of the first case of COVID-19 pneumonia that initially developed acute pulmonary embolism and subsequently showed progression toward pulmonary fibrosis and spontaneous pneumothorax.
Microstructure Evolution and Mechanical Properties of FeCoCrNiCuTi0.8 High-Entropy Alloy Prepared by Directional Solidification
Authors: Xu Yiku , Li Congling , Huang Zhaohao , Chen Yongnan , Zhu Lixia
Published: July 2020

A CoCrCuFeNiTi0.8 high-entropy alloy was prepared using directional solidification techniques at different withdrawal rates (50 μm/s, 100 μm/s, 500 μm/s). The results showed that the microstructure was dendritic at all withdrawal rates. As the withdrawal rate increased, the dendrite orientation become uniform. Additionally, the accumulation of Cr and Ti elements at the solid/liquid interface caused the formation of dendrites. Through the measurement of the primary dendrite spacing (λ1) and the secondary dendrite spacing (λ2), it was concluded that the dendrite structure was obviously refined with the increase in the withdrawal rate to 500 μm/s. The maximum compressive strength reached 1449.8 MPa, and the maximum hardness was 520 HV. Moreover, the plastic strain of the alloy without directional solidification was 2.11%, while the plastic strain of directional solidification was 12.57% at 500 μm/s. It has been proved that directional solidification technology can effectively improve the mechanical properties of the CoCrCuFeNiTi0.8 high-entropy alloy.
Decoding Analysis of Alpha Oscillation Networks on Maintaining Driver Alertness
Authors: Zhang Chi , Ma Jinfei , Zhao Jian , Liu Pengbo , Cong Fengyu , Liu Tianjiao , Li Ying , Sun Lina , Chang Ruosong
Published: July 2020

The countermeasure of driver fatigue is valuable for reducing the risk of accidents caused by vigilance failure during prolonged driving. Listening to the radio (RADIO) has been proven to be a relatively effective “in-car” countermeasure. However, the connectivity analysis, which can be used to investigate its alerting effect, is subject to the issue of signal mixing. In this study, we propose a novel framework based on clustering and entropy to improve the performance of the connectivity analysis to reveal the effect of RADIO to maintain driver alertness. Regardless of reducing signal mixing, we introduce clustering algorithm to classify the functional connections with their nodes into different categories to mine the effective information of the alerting effect. Differential entropy (DE) is employed to measure the information content in different brain regions after clustering. Compared with the Louvain-based community detection method, the proposed method shows more superior ability to present RADIO effectin confused functional connection matrices. Our experimental results reveal that the active connection clusters distinguished by the proposed method gradually move from frontal region to parieto-occipital regionwith the progress of fatigue, consistent with the alpha energy changes in these two brain areas. The active class of the clusters in parieto-occipital region significantly decreases and the most active clusters remain in the frontal region when RADIO is taken. The estimation results of DE confirm the significant change (p < 0.05) of information content due to the cluster movements. Hence, preventing the movement of the active clusters from frontal region to parieto-occipital region may correlate with maintaining driver alertness. The revelation of alerting effect is helpful for the targeted upgrade of fatigue countermeasures.
Looking at Extremes without Going to Extremes: A New Self-Exciting Probability Model for Extreme Losses in Financial Markets
Authors: Bień-Barkowska Katarzyna
Published: July 2020

Forecasting market risk lies at the core of modern empirical finance. We propose a new self-exciting probability peaks-over-threshold (SEP-POT) model for forecasting the extreme loss probability and the value at risk. The model draws from the point-process approach to the POT methodology but is built under a discrete-time framework. Thus, time is treated as an integer value and the days of extreme loss could occur upon a sequence of indivisible time units. The SEP-POT model can capture the self-exciting nature of extreme event arrival, and hence, the strong clustering of large drops in financial prices. The triggering effect of recent events on the probability of extreme losses is specified using a discrete weighting function based on the at-zero-truncated Negative Binomial (NegBin) distribution. The serial correlation in the magnitudes of extreme losses is also taken into consideration using the generalized Pareto distribution enriched with the time-varying scale parameter. In this way, recent events affect the size of extreme losses more than distant events. The accuracy of SEP-POT value at risk (VaR) forecasts is backtested on seven stock indexes and three currency pairs and is compared with existing well-recognized methods. The results remain in favor of our model, showing that it constitutes a real alternative for forecasting extreme quantiles of financial returns.
Information Search and Financial Markets under COVID-19
Authors: Ahundjanov Behzod B. , Akhundjanov Sherzod B. , Okhunjanov Botir B.
Published: July 2020

The discovery and sudden spread of the novel coronavirus (COVID-19) exposed individuals to a great uncertainty about the potential health and economic ramifications of the virus, which triggered a surge in demand for information about COVID-19. To understand financial market implications of individuals’ behavior upon such uncertainty, we explore the relationship between Google search queries related to COVID-19—information search that reflects one’s level of concern or risk perception—and the performance of major financial indices. The empirical analysis based on the Bayesian inference of a structural vector autoregressive model shows that one unit increase in the popularity of COVID-19-related global search queries, after controlling for COVID-19 cases, results in 0.038 – 0.069 % of a cumulative decline in global financial indices after one day and 0.054 – 0.150 % of a cumulative decline after one week.
Perceived Benefits of a Standardized Patient Simulation in Pre-Placement Dietetic Students
Authors: Wright Hattie H. , Cameron Judi , Wiesmayr-Freeman Tania , Swanepoel Libby
Published: July 2020

The purpose of this study was to evaluate the effect of a simulation-based learning (SBL) experience on perceived confidence in monitoring and evaluation, as part of the delivery of nutrition care of pre-placement dietetic students, and to describe their perceived value of the learning experience post-placement. A mixed method explanatory sequential study design was used. A confidence appraisal scale was developed and completed by students before (n = 37) and after (n = 33) a low fidelity simulation using a volunteer patient in an acute care setting. Two semi-structured focus group discussions with post-placement students (n = 17) were thematically analysed, grounded in phenomenology. Overall perceived confidence in monitoring and evaluating, as part of nutrition care, improved after the simulation [pre-SBL: 74 (62–83) vs. post-SBL: 89 (81–98.5), p = 0.00]. Two factors emerged to modulate confidence, namely (i) structure and (ii) authentic learning. Structure in turn was modulated by two key factors; safety and process. A low fidelity simulation using a standardised patient can improve students’ perceived confidence in monitoring and evaluation, and a well-structured authentic learning experience was valued and positively perceived by most dietetic students.
A Study on the Pattern Effects of Chemical Mechanical Planarization with CNN-Based Models
Authors: Bao Han , Chen Lan , Ren Bowen
Published: July 2020

Chemical mechanical polishing (CMP) has become one of the most important process stages in the fabrication of advanced integrated circuits (IC). The CMP pattern effect strongly influences the planarization of the chip surface morphology after CMP, degrading the performance and the yield of the circuits. In this paper, we introduce a method to predict the post-CMP surface morphology with a convolutional neural network (CNN)-based CMP model. Then, CNN-based, density step height (DSH)-based, and common neural-network-based CMP models are built to compare the accuracy of the predictions. The test chips are designed and taped out and the predictions of the three models are compared with experimental results measured by an atomic force profiler (AFP) and scanning electron microscope (SEM). The results show that CNN-based CMP models have better accuracy by taking advantage of the CNN networks to extract features from images instead of the traditional equivalent pattern parameters. The effective planarization length (EPL) is introduced and defined to make better predictions with real-time CMP models and in dummy filling tasks. Experiments are designed to show a method to solve the EPL.
Measuring the Impact of Accurate Feature Selection on the Performance of RBM in Comparison to State of the Art Machine Learning Algorithms
Authors: Aldwairi Tamer , Perera Dilina , Novotny Mark A.
Published: July 2020

The amassed growth in the size of data, caused by the advancement of technologies and the use of internet of things to collect and transmit data, resulted in the creation of large volumes of data and an increasing variety of data types that need to be processed at very high speeds so that we can extract meaningful information from these massive volumes of unstructured data. The process of mining this data is very challenging since a lot of the data suffers from the problem of high dimensionality. The quandary of high dimensionality represents a great challenge that can be controlled through the process of feature selection. Feature selection is a complex task with multiple layers of difficulty. To be able to grasp and realize the impediments associated with high dimensional data a more and in-depth understanding of feature selection is required. In this study, we examine the effect of appropriate feature selection during the classification process of anomaly network intrusion detection systems. We test its effect on the performance of Restricted Boltzmann Machines and compare its performance to conventional machine learning algorithms. We establish that when certain features that are representative of the model are to be selected the change in the accuracy was always less than 3% across all algorithms. This verifies that the accurate selection of the important features when building a model can have a significant impact on the accuracy level of the classifiers. We also confirmed in this study that the performance of the Restricted Boltzmann Machines can outperform or at least is comparable to other well-known machine learning algorithms. Extracting those important features can be very useful when trying to build a model with datasets with a lot of features.
Intellino: Processor for Embedded Artificial Intelligence
Authors: Yoon Young Hyun , Hwang Dong Hyun , Yang Jun Hyeok , Lee Seung Eun
Published: July 2020

The development of computation technology and artificial intelligence (AI) field brings about AI to be applied to various system. In addition, the research on hardware-based AI processors leads to the minimization of AI devices. By adapting the AI device to the edge of internet of things (IoT), the system can perform AI operation promptly on the edge and reduce the workload of the system core. As the edge is influenced by the characteristics of the embedded system, implementing hardware which operates with low power in restricted resources on a processor is necessary. In this paper, we propose the intellino, a processor for embedded artificial intelligence. Intellino ensures low power operation based on optimized AI algorithms and reduces the workload of the system core through the hardware implementation of a neural network. In addition, intellino’s dedicated protocol helps the embedded system to enhance the performance. We measure intellino performance, achieving over 95% accuracy, and verify our proposal with an field programmable gate array (FPGA) prototyping.
Application of Wireless Sensor Network Based on Hierarchical Edge Computing Structure in Rapid Response System
Authors: Wang Yuechun , Man Ka Lok , Lee Kevin , Hughes Danny , Guan Sheng-Uei , Wong Prudence
Published: July 2020

This paper presents a rapid response system architecture for the distributed management of warehouses in logistics by applying the concept of tiered edge computing. A tiered edge node architecture is proposed for the system to process computing tasks of different complexity, and a corresponding rapid response algorithm is introduced. The paper emphasizes the classification of abstracted outlier sensing data which could better match different sensing types and transplant to various application fields. A software-defined simulation is used to evaluate the system performance on response time and response accuracy, from which it can be concluded that common predefined emergency cases can be detected and responded to, rapidly.
Multiport Driving Topology for a Photovoltaic Aircraft Light Transmission System Driven by Switched Reluctance Motors
Authors: Zan Xiaoshu , Zhang Wenyuan , Ni Kai , Jiang Zhikai , Gong Yi
Published: July 2020

In order to meet the working requirements of high performance and low cost for a photovoltaic (PV) aircraft driven by switched reluctance motors (SRMs), a multiport driving topology (MDT) is proposed. The converter is composed of an asymmetric half-bridge and a multiport power source circuit. Three driving and two charging modes can be realized through simple control of the switches. The output torque and the efficiency of the system are improved, because the excitation and demagnetization processes are accelerated by increasing the commutation voltage. The battery pack can be self-charged when the system is running, and PV panels can be used to charge the battery pack to reduce energy consumption when the system is stationary. The simulation analysis and the experimental verification on an 8/6 SRM confirm the effectiveness of the MFT proposed in this paper.
Economics of Distributed Power Generation via Gasification of Biomass and Municipal Solid Waste
Authors: Indrawan Natarianto , Simkins Betty , Kumar Ajay , Huhnke Raymond L.
Published: July 2020

More than one billion people worldwide still lack access to electricity. Rural electrification via gasification has the potential to satisfy electricity access and demand. This study conducts an economic evaluation of rural electrification through gasification of biomass and municipal solid waste (MSW) using a 60 kW downdraft gasifier, developed at Oklahoma State University. The effects of feedstock cost, electricity selling price, feed-in-tariff, tipping fee, tax rate, and the output power are evaluated using major financial parameters: the net present value, internal rate of return, modified internal rate of return, simple payback period, and discounted payback period, and sensitivity analysis. Results show that the downdraft gasification power system offers a payback period of 7.7 years, while generating an internal rate of return, modified internal rate of return, and net present value of 10.9%, 7.7%, and $84,550, respectively. Results from a sensitivity analysis indicate that the feed-in-tariff has the greatest positive contribution to the project’s net present value. Using MSW, the gasification power system potentially reduces carbon dioxide, nitrogen oxides, and sulfur dioxide emissions as compared to direct combustion and landfill. The technology provides a promising future for rural electrification utilizing biomass and MSW whilst offering economic and environmental benefits for local communities.
Study on Variation Laws of Fluid Threshold Pressure Gradient in Low Permeable Reservoir
Authors: Zhao Mingwei , Cao Mengjiao , He Haonan , Dai Caili
Published: July 2020

A study on the seepage characteristics and laws of nano-micron pore throat in a low permeable reservoir matrix is of great significance for promoting high efficacy of low permeable reservoirs. Threshold pressure gradient (TPG) is an essential factor to reflect the seepage law. Here, variation laws of TPG and its influencing factors of low reservoir fluid are analyzed systematically through physical simulation experiment. Throat diameter distribution of cores was measured by a mercury injection method, and it was found that with the decrease of pore throat median diameter, TPG increase appeared slowly first and fast afterwards. The patterns of the TPG with permeability in water and oil were compared. Results showed that the TPG versus permeability gave power functions in a form and the TPG in oil was more than two times larger than that of water. Besides, TPG in two-phase flow was investigated by the stabilization method. Tests revealed that the higher the oil saturation, the greater the TPG value, and the TPG in two-phase flow is always higher than that of single-phase flow under the same conditions, which function as the combined action of the capillary force. In addition, the effects of core length, fluid type, and core wettability on the TPG were studied systematically, which has guiding significance for the development of a low permeability reservoir.
Dynamics of Connectedness in Clean Energy Stocks
Authors: Fuentes Fernanda , Herrera Rodrigo
Published: July 2020

This paper examines the dynamics of connectedness among the realized volatility indices of 16 clean energy stocks belonging to the SPGCE and the implied volatility indices of two important stock markets—the S&P 500 and the STOXX50—and two commodities markets—the crude oil and gold markets. The empirical results show a unidirectional connectedness from the implied volatility indices to the clean energy stocks. Our analysis further reveals similar volatility connectedness behaviors among companies in the same energy production subsector. However, there exists heterogeneous behavior between different energy production subsectors over time. Further, we identify pairwise directional connectedness clusters among related companies, indicating that there are few possibilities for portfolio diversification within the energy production subsectors. Finally, through an impulse–response analysis, we confirm that the expectation of future market volatility of the S&P 500 index and the gold price plays a leading role in volatility connectedness with clean energy stocks.
Green Diesel Production over Nickel-Alumina Nanostructured Catalysts Promoted by Copper
Authors: Gousi Mantha , Kordouli Eleana , Bourikas Kyriakos , Symianakis Emmanouil , Ladas Spyros , Kordulis Christos , Lycourghiotis Alexis
Published: July 2020

A series of nickel–alumina catalysts promoted by copper containing 1, 2, and 5 wt. % Cu and 59, 58, and 55 wt. % Ni, respectively, (symbols: 59Ni1CuAl, 58Ni2CuAl, 55Ni5CuAl) and a non-promoted catalyst containing 60 wt. % Ni (symbol: 60NiAl) were prepared following a one-step co-precipitation method. They were characterized using various techniques (N2 sorption isotherms, XRD, SEM-EDX, XPS, H2-TPR, NH3-TPD) and evaluated in the selective deoxygenation of sunflower oil using a semi-batch reactor (310 °C, 40 bar of hydrogen, 96 mL/min hydrogen flow rate, and 100 mL/1 g reactant to catalyst ratio). The severe control of the co-precipitation procedure and the direct reduction (without previous calcination) of precursor samples resulted in mesoporous nano-structured catalysts (most of the pores in the range 3–5 nm) exhibiting a high surface area (192–285 m2 g−1). The promoting action of copper is demonstrated for the first time for catalysts with a very small Cu/Ni weight ratio (0.02–0.09). The effect is more pronounced in the catalyst with the medium copper content (58Ni2CuAl) where a 17.2% increase of green diesel content in the liquid products has been achieved with respect to the non-promoted catalyst. The copper promoting action was attributed to the increase in the nickel dispersion as well as to the formation of a Ni-Cu alloy being very rich in nickel. A portion of the Ni-Cu alloy nanoparticles is covered by Ni0 and Cu0 nanoparticles in the 59Ni1CuAl and 55Ni5CuAl catalysts, respectively. The maximum promoting action observed in the 58Ni2CuAl catalyst was attributed to the finding that, in this catalyst, there is no considerable masking of the Ni-Cu alloy by Ni0 or Cu0. The relatively low performance of the 55Ni5CuAl catalyst with respect to the other promoted catalysts was attributed, in addition to the partial coverage of Ni-Cu alloy by Cu0, to the remarkably low weak/moderate acidity and relatively high strong acidity exhibited by this catalyst. The former favors selective deoxygenation whereas the latter favors coke formation. Copper addition does not affect the selective-deoxygenation reactions network, which proceeds predominantly via the dehydration-decarbonylation route over all the catalysts studied.
Exploring Solar and Wind Energy as a Power Generation Source for Solving the Electricity Crisis in Libya
Authors: Kassem Youssef , Çamur Hüseyin , Aateg Ramzi Aateg Faraj
Published: July 2020

The current study is focused on the economic and financial assessments of solar and wind power potential for nine selected regions in Libya for the first time. As the existing meteorological data, including wind speed and global solar radiation, are extremely limited due to the civil war in the country, it was therefore decided to use the NASA (National Aeronautics and Space Administration) database as a source of meteorological information to assess the wind and solar potential. The results showed that the country has huge solar energy potential compared to wind energy potential. Additionally, it is found that Al Kufrah is a suitable region for the future installation of the Photovoltaic (PV) power plant due to high annual solar radiation. Based on the actual wind speed analysis, Benghazi and Dernah are the best regions for large-scale wind farm installation in the future taking into account existing meteorological data limitations. The values of the wind power density in all regions are considerable and small-scale wind turbines can be used to generate electricity based on NASA average monthly wind data for 37 years (1982–2019). Moreover, this work aimed to evaluate the wind/PV systems technical and economically through RETScreen Expert (Version 6.0, CanmetENERGY Varennes Research Centre of Natural Resources Canada, Varennes, Canada). Focusing on the power supply crisis in the country, the potential of electricity production by 5 kW grid-connected residential/household rooftop PV in all regions is proposed and presented. Additionally, this paper evaluated a techno-economic analysis of the 50MW wind/PV system in suitable places. The performance of a 5 kW and 50 MW PV solar system with three PV technologies, namely mono-crystalline silicon, poly-crystalline silicon, and thin-film (CdTe), was also analyzed. The results demonstrated that the development of the wind/PV system in the selected regions is both technically and economically feasible. The outcomes of this study can help decision-makers in designing and installing PV power plants as an alternative source for the future.