bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potential role of ACE2 in coronavirus disease 2019 (COVID-19) prevention and management
Authors: Liu Mengyuan , Wang Ting , Zhou Yun , Zhao Yutong , Zhang Yan , Li Jianping 
Published: May 2020

Abstract
COVID-19 is the current public health threat all over the world. Unfortunately, there is no specific prevention and treatment strategy for this disease. We aim to explore the potential role of angiotensin-converting enzyme 2 (ACE2) in this regard through this literature review. As a crucial enzyme of renin-angiotensin-aldosterone system (RAAS), ACE2 not only mediates the virus entry but also affects the pathophysiological process of virus-induced acute lung injury (ALI), as well as other organs’ damage. As interaction of COVID-19 virus spike and ACE2 is essential for virus infection, COVID-19-specific vaccine based on spike protein, small molecule compound interrupting their interaction, human monoclonal antibody based on receptor-binding domain, and recombinant human ACE2 protein (rhuACE2) have aroused the interests of researchers. Meanwhile, ACE2 could catalyze angiotensin II (Ang II) to form angiotensin 1-7 (Ang 1-7), thus alleviates the harmful effect of Ang II and amplifies the protection effect of Ang1-7. ACE inhibitor and angiotensin II receptor blocker (ARB) have been shown to increase the level of expression of ACE2 and could be potential strategies in protecting lungs, heart, and kidneys. ACE2 plays a very important role in the pathogenesis and pathophysiology of COVID-19 infection. Strategies targeting ACE2 and its ligand, COVID-19 virus spike protein, may provide novel method in the prevention and management of novel coronavirus pneumonia.
Clostridium perfringens in gas gangrene: Still a smoked gun!
Authors: Preseau Thierry , Deviendt Jacques , Duttman Ruth , Attou Rachid , Franck Diane , Claeys Ruben , Honoré Patrick M. , Bels David De 
Published: May 2020

Abstract
Gas gangrene (GG) remains a life-threatening and deadly disease. Early recognition together with daily surgical debridement remains the mainstay of therapy. We sought to describe a fatal case of necrotizing soft tissue infection, which was a gas gagrene in this case. This case was remarkable as two main sites were infected simultaneously in geographical zones very far from each other making dissemination between both sites almost impossible. The other particularity was the fact that the infection was caused at the same time by four different bacteria that is atypical in GG similar to that in streptoccocal necrotizing fasciitis where one bacteria is the causative agent (Clostridium perfringens for GG and group A streptococcus for necrotizing fasciitis).
Prevalence and drug resistance of Salmonella in dogs and cats in Xuzhou, China
Authors: Wei Lingling , Yang Cheng , Shao Wangfeng , Sun Tongzheng , Wang Jianyu , Zhou Zhengkun , Chen Caifa , Zhu Aihua , Pan Zhiming 
Published: May 2020

Abstract

Introduction
Salmonellosis is a zoonotic disease, and Salmonella spp. can sometimes be found in dogs and cats, posing a risk to human health. In this study, the prevalence and antimicrobial susceptibility of faecal Salmonella were investigated in pet dogs and cats in Xuzhou, Jiangsu Province, China.

Material and Methods
Faecal samples from 243 dogs and 113 cats, at seven pet clinics, were tested between March 2018 and May 2019. Each Salmonella isolate was characterised using serotyping and antimicrobial susceptibility tests.

Results
The prevalence of Salmonella was 9.47% in dogs and 1.77% in cats. Among the 25 isolates, eight serotypes of Salmonella enterica subsp. enterica were detected, S. Kentucky (n = 11), S. Indiana (n = 5), and S. Typhimurium (n = 4) predominating. S. Derby, S. Toucra, S. Sandiego, S. Newport, and S. Saintpaul all occurred singly. The 23 Salmonella strains found in dogs were from seven different serovars, while the two strains in cats were from two. The highest resistance rates were found for tetracycline (92%), azithromycin (88%), cefazolin (84%), nalidixic acid (80%), ampicillin (80%), ceftriaxone (80%), and streptomycin (76%). Resistance to three or more antimicrobial agents was detected in 24 (96%) isolates. Most of the S. Kentucky and S. Indiana isolates were multi-drug resistant to more than 11 agents.

Conclusion
The carriage rate was far higher in dogs than in cats from Xuzhou. Some isolated strains were highly resistant to antimicrobials used to treat infections in humans and pets, which may raise the risk of humans being infected with multi-drug resistant Salmonella via close contact with pets.
Characterization of AZ31-NbC surface composite fabricated by friction stir processing
Authors: Muralimanokar M. , Vaira Vignesh R. , Padmanaban R. , Suganya Priyadharshini G. 
Published: May 2020

Abstract
AZ31D magnesium alloy is widely used in automotive, aircraft, and aerospace applications because of its high strength to weight ratio. However, the softness of the alloy results in higher wear rate and the high activity results in higher corrosion rate. With an aim of reducing the wear rate and corrosion rate of AZ31 alloy, surface composite of AZ31 alloy is fabricated by reinforcing niobium carbide (NbC) by friction stir processing. The microstructure and dispersion of the reinforcements in AZ31-NbC surface composite is analysed by optical microscopy. In addition, the microhardness and tribological characteristics of the developed AZ31-NbC surface composite are investigated. The results demonstrated an increase in microhardness (23.2 %) and the decrease in wear rate (15.6 % for a normal load of 2 kg) in the developed AZ31-NbC surface composite with respect to the base material. The immersion corrosion test was performed to analyse the corrosion rate of the developed AZ31-NbC surface composite in simulated sea water environment (3.5 wt % NaCl solution). The results indicate that the corrosion rate of the developed AZ31-NbC surface composite is higher than that of base material. A comprehensive analysis on the wear and corrosion mechanism of the developed AZ31-NbC surface composite is presented.
Facies patterns and depositional processes in two Frasnian mixed siliciclastic-carbonate systems in the Cantabrian Mountains, northwest Spain
Authors: van Loevezijn Gerard B.S. , Raven J.G.M. 
Published: May 2020

Abstract
Relative sea level fluctuations during the Frasnian generated two shallow-marine, mixed siliciclastic-carbonate successions in the Devonian Asturo-Leonese Basin. Each system represents a third-order sequence-stratigraphical unit deposited in the same basin during comparable extreme greenhouse conditions without nearby fluvial entry points. Depositional control on the siliciclastic and carbonate distribution was driven by relative sea level fluctuations, basin geometry, availability of sand and the way sediment was distributed by shelf currents. Early Variscan flexural bending of the continental crust changed the basin shape from a shelf with a gradual profile and low dip (early Frasnian) towards a shelf with a steep depositional dip (late Frasnian). Shelf distribution changed from along-shelf transport (early Frasnian) towards offshore-directed gravity flows (late Frasnian). As a consequence, siliciclastic-carbonate distribution changed from a predominance of skeletal carbonate in the proximal shoreface – foreshore area and siliciclastic predominance distally (early Frasnian), to a distribution pattern with proximal shoreface skeletal carbonates, offshore muddy carbonates and a siliciclastic zone in between where gravity flows distributed the siliciclastic sediment down dip (late Frasnian).
Episkeletozoans and bioerosional ichnotaxa on isolated bones of Late Cretaceous mosasaurs and cheloniid turtles from the Maastricht area, the Netherlands
Authors: Jagt John W.M. , Deckers Mart J.M. , De Leebeeck Magda , Donovan Stephen K. , Nieuwenhuis Eric 
Published: May 2020

AbstractIsolated bones of three taxa of marine reptiles (Mosasaurus hoffmanniiMantell,Plioplatecarpus marshiDollo andAllopleuron hofmanni(Gray)) from various levels within the Maastricht Formation (upper Maastrichtian) at the former ENCI-HeidelbergCement Group quarry (Maastricht, the Netherlands) exhibit bioerosional traces and encrustation. Episkeletozoans include dimyid, ostreid and monopleurid bivalves, at least three species of cheilostome and cyclostome bryozoans and two adnate calcareous foraminifera. The bones show biting traces (Gnathichnus pentaxBromley,Linichnuscf.serratusJacobsen & Bromley andMachichnusisp.), as well as borings. The latter may be referred toKarethraichnus lakkosZonneveld, Bartels, Gunnell & McHugh, which is here considered to be a junior synonym ofGastrochaenolitesisp.
3-Way Lunar Radio Ranging Experiment on RT-32 Radio Telescopes
Authors: Marshalov D. , Ping J. , Li W. , Wang M. , Sun J. , Bondarenko Yu. , Vasilyev M. , Yagudina E. 
Published: May 2020

Abstract
Since 2017, the Institute of Applied Astronomy of the Russian Academy of Sciences in cooperation with the National Astronomical Observatories of the Chinese Academy of Sciences has been conducting observations of the Chang’E-3 lander carrier wave signal. The paper presents the features of observation scheduling and results of data processing. High-precision phase radar measurements have been obtained with an instrumental error of 1–2 mm. The deviation of residuals in model calculations does not exceed ± 1 cm. The estimates of CE-3 lander position have been obtained with an accuracy of 0.5’’, 7.4 m and 3.2 m in celenocentric cylindrical longitude, Px and Py coordinates, respectively.
The Joint SLR (Optical Range) and Radar-VLBI Satellite Observations using VIRAC Radio Telescope RT32, RT16 and SLR Station Riga
Authors: Skirmante K. , Jekabsons N. , Salmins K. , Bezrukovs V. , Nechaeva M. 
Published: May 2020

Abstract
Joint VLBI and SLR satellite tracking is a novel tracking approach to explore potential applications and to work out common procedures to coordinate observations between astronomical observatories in Latvia. Global Navigation Satellite System (GNSS) satellites equipped with laser retroreflectors have been chosen as test targets because they are accessible by both measuring techniques – satellite laser ranging (SLR) and Very Long Base Interferometry (VLBI).
The first Joint SLR and VLBI observations of selected GNSS satellites using three of Latvian large-scale astronomical utilities – VIRAC radio telescopes RT32 and RT16 (Ventspils International Radio Astronomy Centre of Ventspils University of Applied Sciences) with L band receivers and SLR station Riga (Institute of Astronomy of University of Latvia) were obtained in 2016 (NKA16) and 2017 (NKA41 and NKA42).
Land Cover Classification using Very High Spatial Resolution Remote Sensing Data and Deep Learning
Authors: Ķēniņš R. 
Published: May 2020

Abstract
The paper describes the process of training a convolutional neural network to segment land into its labelled land cover types such as grass, water, forest and buildings. This segmentation can promote automated updating of topographical maps since doing this manually is a time-consuming process, which is prone to human error. The aim of the study is to evaluate the application of U-net convolutional neural network for land cover classification using countrywide aerial data. U-net neural network architecture has initially been developed for use in biomedical image segmentation and it is one of the most widely used CNN architectures for image segmentation. Training data have been prepared using colour infrared images of Ventspils town and its digital surface model (DSM). Forest, buildings, water, roads and other land plots have been selected as classes, into which the image has been segmented. As a result, images have been segmented with an overall accuracy of 82.9 % with especially high average accuracy for the forest and water classes.
GNSS RTK Performance Improvements using Galileo Satellite Signal
Authors: Zvirgzds J. , Celms A. 
Published: May 2020

Abstract
Two factors of the existing GNSS Real-Time Kinematic (RTK) positioning are as follows: distance-dependence and unreliable ambiguity resolution under bad observation conditions in cities or forests. Use of multi-frequency GNSS signals and systems could possibly redefine RTK services in LatPos, regionally and globally, and more redundant measurements from multiple satellite systems, such as NAVSTAR, Galileo, Glonass and BeiDou, can improve the performance of RTK measurement results in terms of accuracy, availability, reliability and time to fix. The benefits of multiple systems of GNSS services are as follows: 1) savings in the reference station infrastructure costs, and 2) improvement on RTK preciseness and reliability for the professional users. The paper aims at studying how the RTK system, using multiple satellite constellations, performs, adding Galileo signal measurements. Galileo measurements are observed using a field receiver and corrections received from LatPos base station network. Numerical analysis is performed using real-time corrections in field receivers, and results from collected RINEX data are compared by various computing schemes, such as L1/L2 and wide lane signals, NAVSTAR and NAVSTAR with Galileo measurements. The results have preliminary demonstrated the significant improvement using both GNSS satellite signals. Further improvements on the LatPos system have been introduced and the planned improvements shown.
Natural Gas and Biomethane in the European Road Transport: The Latvian Perspective
Authors: Savickis J. , Zemite L. , Zeltins N. , Bode I. , Jansons L. 
Published: May 2020

Abstract
The European Union (hereafter – the EU) takes a strong position in the global fight against climate changes by setting ambitious targets on reduction of greenhouse gas (hereafter – GHG) emissions. A binding target is to reduce those emissions by at least 40 % below 1990 levels till 2030, which would help make Europe the first climate neutral continent by the mid-21st century. Consequently, the expected 2050 emission reduction target for the EU is 80 %–90 % below 1990 levels. The EU’s new economy decarbonisation framework – The European Green Deal – outlines and summarises Europe’s ambition to become a world’s first climate neutral continent by 2050. This supposedly can be achieved by turning climate and environmental challenges into opportunities across all policy areas and making the energy transition just and inclusive for all.
The transport, and particularly road transport, is one of the most significant fossil fuel dependent segments of national economies across the EU. Oil dependency of all segments of the transport sector makes it the single biggest source of GHG emissions in the united Europe as well. Road transport is responsible for about 73 % of total transport GHG emissions, as Europe’s more than 308.3 million road vehicles are over 90 % reliant on conventional types of oil-based fuels (diesel, gasoline etc.).
However, there is a wide range of low-emission alternative fuels for all kinds of transport that can reduce overall oil dependence of the EU’s transport sector and significantly lower GHG in road transport. Among these alternatives a tandem of the natural gas and biomethane could be named as one of the most promising for short and mid-term transport decarbonisation solutions both in the EU and Latvia.
A Simple and Rapid LC-MS/MS Method for Determination of Dexamethasone in Bovine Milk
Authors: Ural Mehmet Nihat , Kotan Arzu 
Published: May 2020

Abstract
This study provides insight into the development and validation of the simple, rapid and sensitive method of Liquid Chromatography-Tandem Mass Spectrometry for determining the residues of dexamethasone in bovine milk. The maximum residue limit for dexamethasone in bovine milk is 0.3 ng/ml−1. Chromatographic separation was achieved on an Agilent Proshell 120 SB:C18 (2.7µm 100x3.0 mm) column. The bovine milk was extracted with ethyl acetate, and the evaporated elution was dissolved with hexane, water and methanol, and analyzed by the LC-MS/MS method. The mobile phase A was a solution of 5 Mm ammonium formate in water, while the mobile phase B was 0.1% formic acid in acetonitrile. The calibration graphics were prepared within the range of 0.15–0.6 ng/ml−1, and a successful linearity was achieved (r ≥0.999). The limit of detection was 0.016 ng/ml−1. The decision limit (CCα) and detection capability (CCβ) were 0.34 and 0.38 ng/ml−1, respectively.
Poland in international migrations: the perspective of world systems theory
Authors: Żołędowski Cezary 
Published: May 2020

Abstract
This article presents the special status of Poland, namely as a country that both sends out and takes in large numbers of migrant workers. Drawing on the world systems theory, the role attributed to Poland is that of semi-periphery, which means a specific kind of suspension between the status of an immigration centre, resembling western Europe, and the status of a migration periphery, such as the one constituted by the eastern part of the continent. Poland continues to be viewed as peripheral by its own citizens who decide to emigrate and, at the same time, becomes an immigration sub-centre for migrants coming from less-developed countries. In this article, the distinctive features of the special position of Poland are discussed. The conclusions drawn are supported by empirical evidence, including data on migration flows and interviews both with Poles working abroad and foreigners employed in Poland.
Thin films of copper phthalocyanine deposited by solution processing methods
Authors: Gojzewski Hubert , Ghani Fatemeh , Szybowicz Mirosław 
Published: May 2020

Abstract
In this work, we show and discuss the surface structure picture of copper phthalocyanine (CuPc) thin films deposited from trifluoroacetic acid (TFA) solvent onto silicon substrates at ambient conditions by four solution processing methods, namely drop-casting, dip-coating, spin-casting and spray-coating. The CuPc films were studied by AFM, as the main technique, and complemented by micro-Raman spectroscopy. Essentially, such thin films consist of CuPc molecular nanoribbons of a fixed ~1 nm thickness. CuPc molecules are arranged in an in-plane direction and formed in stacks under a defined tilt angle with respect to the substrate surface (monolayer) or underlying CuPc layer (multilayer). The film morphology takes various forms depending on the solution concentration, number of layers, and the deposition method. For instance, the morphology varies from very wide (~600 nm) but flat (~1 nm) ribbons for films prepared by dip-coating to crystallized rod-like features (multi-layered ribbons) when obtained by spray-coating. The factors studied in this paper should be taken into consideration in designing and controlling the criteria for rigorous CuPc film architecture.
Enhancement of electrical performance of ZnSe thin films via Au nanosandwiching
Authors: Qasrawi A.F. , Taleb Maram F. 
Published: May 2020

Abstract
In this work, we report the effect of sandwiching of Au nanosheets on the structural and electrical properties of ZnSe thin films. The ZnSe films which are grown by the thermal evaporation technique onto glass and yttrium thin film substrates exhibit lattice deformation accompanied with lattice constant extension, grain size reduction and increased defect density upon Au nanosandwiching. The temperature dependent direct current conductivity analysis has shown that the 70 nm thick Au layers successfully increased the electrical conductivity by three orders of magnitude without causing degeneracy. On the other hand, the alternating current conductivity studies in the frequency domain of 10 MHz to 1800 MHz have shown that the alternating current conduction in ZnSe is dominated by both of quantum mechanical tunneling and correlated barrier hopping of electrons over the energy barriers formed at the grain boundaries. The Au nanosheets are observed to increase the density of localized states near Fermi level and reduce the average hopping energy by ~5 times. The conductivity, capacitance, impedance and reflection coefficient spectral analyses have shown that the nanosandwiching of Au between two layers of ZnSe makes the zinc selenide more appropriate for electronic applications and for applications which need microwave cavities.
Impact of firing temperature on insulating properties of Low Temperature Co-fired Ceramics
Authors: Dabrowski Arkadiusz P. 
Published: May 2020

Abstract
In this paper, results of investigation on the impact of firing temperature on insulating properties of Low Temperature Cofired Ceramics are presented. Dissipation factor, volume resistivity and breakdown electric field intensity were determined for firing peak temperature in the range from 800 °C to 900 °C. The tests were performed for two commercial LTCC materials: 951 Green Tape (DuPont, USA) and SK47 (Keko, Slovenia). The results showed that the firing temperature had a significant effect on the dielectric loss factor, volume resistivity and lifetime at applied high voltage. No clear tendency was observed for dielectric strength in the analyzed firing temperature range.
Ca4−xLa2+xTi5−xBxO17 (B = Al, Ga) dielectric ceramics for microwave applications
Authors: Muhammad Raz , Khesro Amir 
Published: May 2020

Abstract
In this study, Ca4−xLa2+xTi5−xBxO17 (B = Al, Ga; x = 0, 1) ceramics were processed via a mixed oxide solid state sintering route and characterized using XRD, SEM, EDS and Vector Network Analyzer. Phase analysis of the samples showed single phase formation for the sample x = 0 while secondary phases formed for Ca4−xLa2+xTi5−xBxO17 (B = Al, Ga; x = 1) ceramics. Ca4La2Ti5O17 exhibited ∈r = 74, Q×fo = 14,116 GHz and τf = 157 ppm/°C. The substitution of Ga or Al for Ti at the B-site of Ca4La2Ti5O17 ceramics significantly improved the microwave dielectric properties i.e. Ca3La3Ti4GaO17 and Ca3La3Ti4AlO17 have ∈r = 44, Q×fo = 16,128 GHz and τf = 7.3 ppm/°C and ∈r = 46, Q×fo = 13,754 GHz and τf = −2 ppm/°C, respectively. The microwave dielectric properties of these materials are suitable for high frequency microwave applications.
Bismuth and lead based metal organic frameworks: morphological, luminescence and Brunauer-Emmett-Teller (BET) studies
Authors: Iram Shamaila , Imran Muhammad , Kanwal Farah , Latif Shoomaila , Iqbal Zafar 
Published: May 2020

Abstract
Biphenyl-4,4′-dicarboxylic acid (H2BDA) was used as an organic linker to synthesize bismuth and lead based organic frameworks (1 and 2). The structural/morphological studies of these metal organic frameworks (MOFs) were done using UV-Vis, Fourier transform infrared spectroscopy (FT-IR), 1H NMR, energy dispersive spectroscopy (EDXS), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and powder X-ray diffraction method. Surface area as determined by Brunauer-Emmett-Teller (BET) studies revealed better N2 gas adsorption for MOF (1) compared to MOF (2). Both these MOFs exhibited good luminescence activity which was attributed to ligand-to-metal charge transfer transitions (LMCT).
Synthesis, growth and studies of pristine and nickel doped L-valinium picrate crystals for organic light emitting diodes applications
Authors: Ragunathan A. S. , Selvapandiyan M. 
Published: May 2020

Abstract
Single crystals of L-Valinium Picrate (LVP), 0.1 mol% Ni2+ doped L-Valinium Picrate, and 0.2 mol% Ni 2+ doped L-Valinium Picrate were grown by low temperature solution growth method, especially by solvent evaporation technique at ambient temperature. Function groups and modes of vibration were identified by FT-IR studies. The grown crystals belong to monoclinic system which has been revealed by powder XRD. The estimated band gaps were found to be 3.86 eV for LVP, 3.72 eV for 0.1 mol% Ni2+ doped LVP, and 3.70 eV for 0.2 mol% Ni2+ doped LVP crystals, respectively. The PL excitation wavelength of the grown materials is 370 nm. All the elements (C, N, O, Ni, and Cl) as per molecular formula were present in the EDAX spectrum of the grown materials. The 0.2 mol% Ni2+ ion doped LVP materials had higher thermal stability (208 °C) than LVP and 0.1 mol% Ni2+ doped LVP.