bluuebunny/crossref_metadata_2025 huggingface dataset:
Recombinant Soybean Lipoxygenase 2 (GmLOX2) Acts Primarily as a ω6(S)-Lipoxygenase
Authors: Smirnova Elena O. , Egorova Alevtina M. , Lantsova Natalia V. , Chechetkin Ivan R. , Toporkova Yana Y. , Grechkin Alexander N.
Published: July 2023

The lipoxygenase (LOX) cascade is a source of bioactive oxylipins that play a regulatory role in plants, animals, and fungi. Soybean (Glycine max (L.) Merr.) LOXs are the classical models for LOX research. Progress in genomics has uncovered a large diversity of GmLOX isoenzymes. Most of them await biochemical investigations. The catalytic properties of recombinant soybean LOX2 (GmLOX2) are described in the present work. The GmLOX2 gene has been cloned before, but only for nucleotide sequencing, while the recombinant protein was not prepared and studied. In the present work, the recombinant GmLOX2 behavior towards linoleic, α-linolenic, eicosatetraenoic (20:4), eicosapentaenoic (20:5), and hexadecatrienoic (16:3) acids was examined. Linoleic acid was a preferred substrate. Oxidation of linoleic acid afforded 94% optically pure (13S)-hydroperoxide and 6% racemic 9-hydroperoxide. GmLOX2 was less active on other substrates but possessed an even higher degree of regio- and stereospecificity. For example, it converted α-linolenic acid into (13S)-hydroperoxide at about 98% yield. GmLOX2 showed similar specificity towards other substrates, producing (15S)-hydroperoxides (with 20:4 and 20:5) or (11S)-hydroperoxide (with 16:3). Thus, the obtained data demonstrate that soybean GmLOX2 is a specific (13S)-LOX. Overall, the catalytic properties of GmLOX2 are quite similar to those of GmLOX1, but pH is optimum.
Winter Climate of Northeastern Dominican Republic and Cash Crop Production
Authors: Jury Mark R.
Published: July 2023

The winter climate of the northeastern Dominican Republic features steady rainfall, which sustains cash crop production. Using a representative season, December 2016–February 2017, the mesoscale climate is characterized by high-resolution reanalysis, satellite measurements and local observations, and statistical analyses of time series from an index area of 18.8–19.6° N, 70.4–69.6° W in the Cibao Valley, where cacao and coffee are grown. Winter rainfall depends on strong trade winds that push shallow stratiform convections over 100 km inland, where nocturnal drainage flows induce orographic uplift. Interannual climate variability is studied in the context of cacao and coffee production in the years 1976–2019. Lag correlations demonstrate that higher yields follow a wet autumn, a windy winter with cool sea temperatures, and a dry spring. Changes in high-value agricultural production in the northeastern Dominican Republic may be anticipated by the climatic determinants uncovered here.
Effect of Electric Properties according to Volume Ratio of Supercapacitor and Battery Capacitor in Hybrid Energy Storage System
Authors: Lee Jong-Kyu , Yoon Jung-Rag
Published: July 2023

The development of technology that combines supercapacitors and lithium-ion batteries by externally connecting them in parallel is ongoing. This study examines the correlation between the volume ratio and electrical characteristics of a cell made by internally connecting a battery capacitor with Li4Ti5O12 as the anode active material and a supercapacitor in parallel. It was found that increasing the volume occupied by the battery capacitor in the cell led to increased cell energy and resistance, resulting in decreased output characteristics. Conversely, increasing the volume occupied by the supercapacitor in the cell led to a decrease in the IR drop during discharge and the cell temperature when evaluating cycle characteristics with a current of 20C. This study also examined the behavior of the current distributed during the charging and discharging process based on the volume ratio of the supercapacitor and the battery capacitor. Analyzing the correlation between the volume ratio and electrical characteristics of supercapacitors and battery capacitors could potentially lead to the development of a new type of energy storage device.
Study on Wear Resistance of Nickel Cladding Layer with Imitation Shell Convex Strip Structure on the Surface of 7075 Aluminum Alloy Drill Pipe
Authors: Zhao Yan , Liao Guorui , Li Xu , Gao Ke , Zhang Congshan , Lv Xiaoshu , Ai Hongxin , Xie Xiaobo
Published: July 2023

In this study, a nickel cladding layer with a bionic convex strip structure was applied to the surface of an aluminum alloy drill pipe, and laser cladding technology was used to improve the wear resistance of the aluminum alloy drill pipe. Firstly, by observing the morphological characteristics of the shell surface, the ratio of the width of the convex strips to the spacing between the convex strips was obtained as 0.39–0.53, and thus a model of the bionic structure was constructed. Numerical simulations were performed, and the results showed that the wear of the bionic structure was reduced by 77.6% compared with that of the smooth structure. Subsequently, the cladding layers of both structures were coated on the drill pipe using nickel powder as the material, and wear tests were performed. The microstructure, composition, and hardness behavior of the cladding layers were analyzed using scanning electron microscopy, an X-ray diffractometer, and a microhardness tester. It was found that the cladding layer mainly consists of Al3Ni2, and there is a transition layer between the cladding layer and the aluminum alloy matrix, whose hardness is lower than that of Al3Ni2. In addition, the groove space can be formed between the convex strips, which effectively reduces the frequency of the debris flow. The results of the wear tests show that the wear of the cladding layer with the bionic structure is reduced by 74.0%. Similar results in numerical simulations and experiments verified that the designed cladding layer with a bionic convex strip structure can significantly improve the wear resistance of aluminum alloy drill pipes.
High-Temperature Corrosion Characteristics of Ni-20Cr-xSi Alloy Laser Cladding Layer in NaCl-KCl-Na2SO4-K2SO4 Mixed Salt Environment
Authors: Chen Shanshan , Liu Zongde , Liu Fulai
Published: July 2023

Ni-Cr-Si-alloy-cladding layers with Si contents of 0 wt.%, 1 wt.%, 3 wt.% and 5 wt.% were prepared via a laser-cladding technique, and the effect of Si content on the high-temperature corrosion resistance of the Ni-20Cr-Si-alloy-cladding layers in NaCl-KCl-K2SO4-Na2SO4 mixed salt was systematically investigated. The results show that at 600 °C, the four cladding layers rely mainly on the generation of dense Cr2O3 on the surface to hinder the continuation of corrosion. The addition of Si helps to improve the stability of Cr2O3 in the mixed salt, and on the other hand Si is enriched in the corrosion layer, which can effectively hinder the penetration of the corrosive medium. The addition of Si can effectively improve the high-temperature corrosion resistance of the Ni-20Cr-cladding layer, whereas the corrosion product layer is prone to spalling when the Si content is ≥3 wt.%. The best corrosion resistance was demonstrated by Ni-20Cr-1Si in NaCl-KCl-K2SO4-Na2SO4 mixed salt.
Ceramic–Titanium Alloy Artificial Hip Joint Wear Simulation and Experimental Study
Authors: Ji Renquan , Chen Fei , Ying Rongmin , Zhang Li
Published: July 2023

The wear of artificial joints can lead to joint noise and tissue pathology within the human body, which is a primary factor affecting their service life. In response to the issue of wear in ceramic–titanium alloy artificial hip joints, this study employed hip joint wear simulations and experimental wear testing on hip joint specimens to investigate the impact of different contact surface parameters on the wear of ceramic–titanium alloy articulating surfaces. The objective was to provide guidance for joint surface treatment to minimize wear. The simulation results demonstrated that the contacting surfaces of the articulating components exhibited a crescent-shaped surface composition before and after wear. The initial variation in the surface friction coefficient had minimal influence on the wear rate after stabilization, whereas excessively high friction coefficients led to erratic changes in wear depth. Based on the simulation results, experimental research was conducted to compare the wear results of different surface roughness values ranging from 60 to 550 nm. The findings revealed that a surface roughness of 150 nm exhibited the least amount of wear and the best anti-wear performance. Furthermore, an exploration of the mechanism behind the influence of different surface friction coefficients on the wear of the articulating surfaces provided valuable insights for surface processing and wear analysis of artificial joints.
Improving Microbial Fuel Cell Performance Using Porous Capacitive Composite Bioanode Materials with Energy Storage Function
Authors: Wang Yuyang , Hu Guangxu , Dong Jing , Wang Jing
Published: July 2023

Microbial fuel cells (MFCs) have shown promise in solving energy and environmental problems, but their practical application is limited by their low power output. In this study, carbon nanotubes/polypyrrole composite anode materials were prepared on a porous sponge matrix. By combining the porous characteristics of sponge, the good conductive properties of carbon nanotubes, and the energy storage ability of polypyrrole capacitive materials, the prepared anode exhibited a large specific capacity, high porosity, large specific surface area, good electron transport ability, and good biocompatibility. The results showed that the maximum power density of the modified anode MFC reached 7.46 W m−3, which was 2.53 times higher than that of the control anode. The stored energy Qs released by the modified anode was 235.6 C m−2, 6.5 times higher than that of the control electrode. In addition, the transfer impedance Rct of the S/CNT/PPy electrode (5.5 Ω) was much lower than that of the control anode (16.8 Ω). The research presented in this paper demonstrates a new approach to improving the power generation ability and energy storage performance of MFCs.
Study on the Duration of Laser-Induced Thin Film Plasma Flash
Authors: Wang Guixia , Su Junhong , Wang Qingsong
Published: July 2023

The accuracy of judging whether the film is damaged directly affects the accuracy of the measurement of the film laser damage threshold. When judging the film damage by the traditional plasma flash method, there is a problem of misjudgment caused by the failure to distinguish the film and air plasma flash. In order to eliminate misjudgment, the two flashes are accurately distinguished by the difference in the duration of the air and film plasma flash. This paper aims to obtain the theoretical and experimental values of the duration of the film plasma flash (tf) and analyze the factors affecting it. Firstly, taking single-layer hafnium oxide and aluminum oxide thin films as examples, when the wavelength of the incident laser is 1064 nm, the diameter of the laser focusing spot is 0.08 cm, the energy of the incident laser is 100 mJ, and the pulse width of incident laser is 10 ns, the tf of hafnium oxide, and aluminum oxide thin films are 542.7 and 299.6 ns, respectively. Secondly, the experimental study of tf was carried out. Through six experiments, the following results were obtained: (1) With the increase in incident laser energy, the tf of both films increases; (2) The tf of the hafnium oxide film is longer than that of the aluminum oxide film. (3) The experimental parameters are put into the calculation model, and the theoretical results are in good agreement with the experimental tf values. Finally, it is found that tf increases with the increase in incident laser energy and incident laser pulse width, and decreases with the increase in focusing spot diameter.
Production and Characterization of Graphene Oxide Surfaces against Uropathogens
Authors: Belo Samuel , Sousa-Cardoso Francisca , Teixeira-Santos Rita , Gomes Luciana C. , Vieira Rita , Sjollema Jelmer , Soares Olívia S. G. P. , Mergulhão Filipe J.
Published: July 2023

Graphene and its functionalized derivatives have been increasingly applied in the biomedical field, particularly in the production of antimicrobial and anti-adhesive surfaces. This study aimed to evaluate the performance of graphene oxide (GO)/polydimethylsiloxane (PDMS) composites against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. GO/PDMS composites containing different GO loadings (1, 3, and 5 wt.%) were synthesized and characterized regarding their morphology, roughness, and hydrophobicity, and tested for their ability to inhibit biofilm formation under conditions that mimic urinary tract environments. Biofilm formation was assessed by determining the number of total and culturable cells. Additionally, the antibacterial mechanisms of action of GO were investigated for the tested uropathogens. Results indicated that the surfaces containing GO had greater roughness and increased hydrophobicity than PDMS. Biofilm analysis showed that the 1 wt.% GO/PDMS composite was the most effective in reducing S. aureus biofilm formation. In opposition, P. aeruginosa biofilms were not inhibited by any of the synthesized composites. Furthermore, 1% (w/v) GO increased the membrane permeability, metabolic activity, and endogenous reactive oxygen species (ROS) synthesis in S. aureus. Altogether, these results suggest that GO/PDMS composites are promising materials for application in urinary catheters, although further investigation is required.
Non-Linear Evaluation of Coatings Performance: Evaluation of Polyester/Melamine Coil Coating Hydrolysis in NSS Test
Authors: García-Ochoa Esteban M. , Suárez-Corrales Xenia I. , Maldonado-Rivas Pablo J. , Talavera-Pech William A. , Corvo Francisco
Published: July 2023

Coating is one of the most common and effective ways to protect metallic elements from corrosion. The evaluation of a coating’s performance is related to its quality and durability. Neutral salt spray (NSS) is a common accelerated test used for coatings. Commercial polyester/melamine coil coatings applied on aluminum specimens were exposed to NSS and recorded at 0, 200,400, 600 and 1000 h of exposure. Coating performance changed with time of exposure. The main degradation process is due to the hydrolysis of the coating. A decrease in corrosion rate was observed due to the sealing of the coating, probably due to the deposition of corrosion products, salts, or a mixture of both. EN (electrochemical noise) was a more sensitive technique comapred to EIS (electrochemical impedance spectroscopy). The first changes in the coating were detected after 400 h of exposure by EIS and after 200 h by EN. EIS and EN showed equivalent results in studying the corrosion evolution of coated aluminum. Non-linear analysis using recursive plots (RP) showed the chaotic dynamics occurring with time and the interaction of micro electrochemical cells that formed on the metallic surface; it offered information similar tothe traditional EIS technique and adds complementary data to understand the corrosion phenomenon.
Influence of Frustration Effects on the Critical Current of DC SQUID
Authors: Askerzade Iman N.
Published: July 2023

In this paper, we conducted the calculation of the critical current of DC SQUID based on the Josephson junction on a multi-band superconductor with frustration effect. It is shown that the critical current of DC SQUID on the frustrated multi-band superconductor with a small geometrical inductance of the loop is determined by the supercurrent amplitude in different channels and by the external magnetic field. In the case of a DC SQUID with high inductance, frustration effects can be ignored.
Effect of Waste Iron Filings (IF) on Radiation Shielding Feature of Polyepoxide Composites
Authors: Alresheedi Mohammed T. , Elsafi Mohamed
Published: July 2023

In the present work, photon and neutron attenuation properties of polyepoxide composites produced by doping waste iron filings (IF) at different percentages (0%, 20%, 40%, and 60% iron filing percentage) were obtained using theoretical and experimental techniques. The experimental technique was performed using an HPGe detector with four different gamma lines (0.0595, 0.6617, 1.173, and 1.333 MeV) emitted from three gamma-ray sources (241Am, 137Cs, and 60Co). The theoretical techniques for shielding parameters calculation are estimated with Phy-X software and the XCOM program as well. The experimental and theoretical values of the mass/linear attenuation coefficient (M/LAC), half/tenth value layer (H/TVL), mean free path (MFP), lead equivalent thickness (LEth), and radiation shielding efficiency (RSE) have been determined and compared. A good agreement was achieved during the comparison. The shielding performance of the prepared composites increased with increasing the iron filing rate, where we can arrange the performance of shielding according to EP–IF60 > EP–IF40 > EP–IF20 > EP–IF0 at all different experimental and theoretical energies. The effective and equivalent (Zeff, Zeq) atomic numbers as well as the exposure buildup factor (EBF) at different depletion distances or mean free paths (MFPs) have been calculated for all EP–IF composites. The lowest EBF was for EP–IF60 while the highest EBF was for EP–IF0 through the discussed energy from 0.015 to 15 MeV. Finally, the fast neutron removal cross-section (FRNC) has been calculated for the prepared composites and the results showed improvement in FNRC with increasing the iron filing rate.
Comparative Analysis of Three Constitutive Models and Microstructure Characteristics of Nb521 during Hot Deformation
Authors: Zhu Baohui , Jia Minghang , Zhao Rui , Wan Min
Published: July 2023

This study presents an exploration of the flow stress constitutive model and the deformation mechanism of Nb521, both critical for its practical application. Hot-compression experiments were performed on Nb521 at temperatures ranging from 1523 K to 1723 K and strain rates ranging from 0.01 to 10 s−1. In addition, the microstructure evolution was concurrently studied through scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD). The stress–strain behaviour of Nb521 was assessed, leading to the development of three constitutive models: the Johnson–Cook model, the modified Johnson–Cook model and the Arrhenius model. In the course of the deformation process, it is consistently observed that the hardening effect surpasses the softening effect during the plastic phase, with no observable occurrence of a steady-state phase. The modified Johnson–Cook model offers superior predictive accuracy. Both grain elongation and torsion are the main deformation mechanisms of Nb521 and specific texture forms during stretching. This study also reveals that fractures at both room temperature and high temperatures are brittle in nature. The elucidation of the constitutive model and underlying deformation mechanisms in this study offers indispensable insights into the hot-deformation behaviour of Nb521.
Efficient Continuous-Wave Eye-Safe Nd:GdVO4/KGW Raman Laser and Sum Frequency Generation for Deep-Red Emission
Authors: Huang Hsin-Jia , Fang Yu-Han , Li Di , Chen Chun-Ling , Liang Hsing-Chih , Chen Yung-Fu
Published: July 2023

A concise, efficient continuous-wave eye-safe Nd:GdVO4/KGW Raman laser at 1525 nm is here demonstrated. A Nd:GdVO4 crystal was used to produce the fundamental field at 1341 nm and a KGW crystal generated the intracavity Stokes field at 1525 nm via wavelength conversion of stimulated Raman scattering. The output power of the Stokes field at 1525 nm could achieve 2.1 W under the pump power of 30 W. Furthermore, two different lithium triborate (LBO) crystals with critical phase matching were exploited to obtain deep-red emission at 714 nm via the intracavity sum frequency generation of 1341 and 1525 nm waves. One cutting angle was in the XY plane and the other was in the XZ plane. The empirical thermo-optical coefficients for the LBO crystal were exploited to systematically analyze the critical phase matching conditions. Numerical results revealed that the type-I phase matching angle in the XY plane was near θ = 90° and ϕ = 3.3° at room temperature, whereas the type-I phase matching angle in the XZ plane was near θ = 86.3° and ϕ = 0° at a temperature around 47 °C. The numerical values for the optimal temperatures for the two different cutting angles were found to be in good agreement with experimental results. At the pump power of 30 W, the output power at 714 nm was approximately 2.9 W by using the LBO crystal with the cutting angle in the XY plane. On the other hand, the maximum output power at 714 nm could be up to 3.2 W under the pump power of 30 W by using the cutting angle in the XZ plane. Furthermore, the linewidth of the SFG emission was confirmed to be nearly the same for the two different cutting angles. The overall linewidth could be narrower than 0.2 nm. The developed laser at 714 nm can be useful in the exploration of ionic and atomic radium isotopes with laser spectroscopy.
Evaluation of Retained Austenite in Carburized Bearing Steel Using Magneto-Inductive Method
Authors: Ionescu Laura , Pantawane Mangesh , Tănase Constantin , Sichim Răducu , Dascălu Catalina , Ghiban Brânduşa
Published: July 2023

The present work explores the magneto-inductive method to evaluate different levels of retained austenite content in carburized 20NiCrMo7 bearing steel while comparing the corresponding measurements by X-ray diffractometry and image analysis by optical microscope. The content of retained austenite in carburized 20NiCrMo7 steel was modified with additional tempering to yield three samples with distinct ranges of retained austenite profiles in the carburized region of the steel. The retained austenite measured at different depths in these samples using the magneto-inductive method had an outcome comparable to other methods. Further discussion based on data suggests that the magneto–induction method yields precise (with an average deviation of 0.5%) results with sufficient sensitivity at different levels (including below 5 vol. %.) of retained austenite.
Designing an Efficient Lead-Free Perovskite Solar Cell through a Computational Method
Authors: Bhattarai Sagar , Kalita P. K. , Hossain Ismail , Alsubaie Abdullah Saad , Mahmoud Khaled Hussein , Ansari Mohd Zahid , Janicek Petr
Published: July 2023

Organometallic halide perovskite (PVK)-based solar cells (PSC) have gained significant popularity owing to their efficiency, adaptability, and versatility. However, the presence of lead in conventional PVK poses environmental risks and hinders effective commercialization. Although lead-free PVK solar cells have been developed, their conversion efficiency is limited due to intrinsic losses. To address this challenge, we present a simulation study focusing on methylammonium tin bromide (MASnBr3) as an alternative material. In our investigation, the MASnBr3 layers are strategically placed between a copper iodide (CuI)-based hole transporting material (HTM) and a zinc oxide (ZnO)-based electron transporting material (ETM). We optimize the active layer thickness, operating temperature, defect density analysis, and series resistances to assess device performance. Furthermore, we employ contour mapping, considering both thickness and defect density, for a detailed investigation. Our primary objective is to achieve unprecedented efficiency in lead-free MASnBr3-based PSCs. Remarkably, our study achieves the highest JSC (short-circuit current density) of 34.09 mA/cm2, VOC (open-circuit voltage) of 1.15 V, FF (fill factor) of 82.06%, and optimized conversion efficiency of 32.19%. These advancements in conversion efficiency pave the way for the development of lead-free PVK solar cells in the desired direction.
Restless Sleep Disorder and the Role of Iron in Other Sleep-Related Movement Disorders and ADHD
Authors: Cameli Noemi , Beatrice Annachiara , Colacino Cinnante Elisa Maria , Gullace Claudia , Lentini Giuliana , Occhipinti Sara , Ferri Raffaele , Bruni Oliviero
Published: July 2023

In the last few years, restless sleep has been described as the key element of many clinical issues in childhood, leading to the recognition of “restless sleep disorder” (RSD) as a new proposed diagnostic category. The essential aid of video-polysomnographic recordings enables detection and quantification of the “large muscle group movements” (such as limb movements and repositioning) frequently described by parents of children with RSD. Strong evidence links iron deficiency to the pathophysiology of sleep-related movement disorders such as RSD, restless legs syndrome, periodic limb movement disorder, and attention deficit hyperactivity disorder (ADHD) due to the important role played by the brain dopamine production system. Serum ferritin is the main parameter used to evaluate iron deficiency in patients with sleep-related movement disorders. Iron supplementation is recommended when the serum ferritin level is <50 ng/mL, since the literature emphasizes the correlation between lower levels of serum ferritin, serum iron, and cerebrospinal fluid ferritin, and increased symptom severity. Moreover, several studies report an improvement in symptoms when ferritin levels are kept above 50 ng/mL. In this narrative review, we discuss the role of iron in sleep-related movement disorders, as well as ADHD, highlighting not only the connection between these two conditions, but also the relevance of iron supplementation for symptom improvement.
Unrecognised Ant Megadiversity in the Australian Monsoonal Tropics: The Melophorus hirsutipes Heterick, Castelanelli & Shattuck Species Group
Authors: Andersen Alan N. , Brassard François , Hoffmann Benjamin D.
Published: July 2023

Melophorus hirsutipes Heterick, Castanelli & Shattuck is a recently described taxon that was presented as occurring throughout most of mainland Australia and showing highly variable morphology. One highly variable character is sculpture, which is smooth and shiny in the type specimen but conspicuously scabrid and even rugulose in other forms. The scabrid and rugulose forms occur primarily in the monsoonal (seasonal) tropics of the northern third of the continent, a region that has recently been shown to be a global centre of ant diversity, but largely unrecognized as such because the great majority of species are undescribed. Here, we provide an integrated morphological, genetic (CO1) and distributional analysis of diversity within the scabrid and rugulose forms of M. ‘hirsutipes’. We recognize 16 species among the 56 scabrid/rugulose specimens sequenced, along with four shiny or shagreenate species that are embedded within them. We conclude that Melophorus ‘hirsutipes’ is a highly diverse group of at least 30 species given the very patchy geographical coverage of sequenced specimens. Our findings provide further evidence that the total number of species in monsoonal Australia is likely in the several thousands, which would make it the world’s richest known region for ant species.
Assessment of Retinal Vessel Tortuosity Index in Patients with Fabry Disease Using Optical Coherence Tomography Angiography (OCTA)
Authors: Hangartner Kevin , Bajka Anahita , Wiest Maximilian R. J. , Sidhu Sophia , Toro Mario D. , Maloca Peter M. , Zweifel Sandrine A.
Published: July 2023

Vessel tortuosity (VT) is a parameter used to assess retinal involvement in patients affected by systemic diseases such as Fabry disease (FD). In this study, we assessed a retinal VT index (VTI) using optical coherence tomography angiography (OCTA) in a group of patients with FD (FD cohort) compared to a healthy control group (HC cohort). This is a single-center, retrospective study analysis of all consecutive patients with genetically tested and confirmed FD who underwent regular ophthalmological visits from December 2017 to January 2020 at the Department of Ophthalmology at the University Hospital of Zurich, Switzerland. VTI was calculated for each OCTA image and the results were compared between FD and HC cohort. A total of 56 participants, 32 (male:female ratio 12:20) in the FD cohort and 24 (male:female ratio 13:11) in the HC cohort. Classic onset was determined in 18 patients. Overall, mean VTI (±SD) was 0.21 (±0.07). Male patients with classic-onset FD had a significantly higher mean VTI (0.33, SD ± 0.35) compared to all other subgroups (p-value < 0.05). Further investigations of retinal VTI in patients with FD could be helpful to use OCTA as a noninvasive screening and follow-up modality to assess disease progression in affected patients.
Infarct-like versus Non-Infarct-like Clinical Presentation of Acute Myocarditis: Comparison of Cardiac Magnetic Resonance (CMR) Findings
Authors: Capasso Raffaella , Imperato Maria Chiara , Serra Nicola , Rodriguez Reimy , Rivellini Maria , De Filippo Massimo , Pinto Antonio
Published: July 2023

Background: The clinical presentation of acute myocarditis (AM) is widely variable, ranging from a subclinical disease to an infarct-like syndrome. Cardiac magnetic resonance (CMR) has become the reference non-invasive diagnostic tool for suspected AM, allowing the identification of the various hallmarks of myocardial inflammation (edema, fibrosis, and hyperemia). The aim of the study was to investigate any differences in morphological, functional, and tissue characterization CMR parameters between infarct-like AM in patients with unobstructed coronary arteries and non-infarct-like AM, diagnosed according to the original Lake-Louise Criteria (LLC); Methods: We retrospectively selected 39 patients diagnosed with AM according to LLC, divided into 2 groups according to the clinical presentation: infarct-like in group 1 patients and non-infarct-like in group 2 patients. CMR morphologic, functional, and tissue characterization parameters were analyzed and compared. Results: In group 1, CMR tissue characterization parameters were mainly altereda in septal location with mesocardial myocardial involvement; in group 2, CMR tissue characterization parameters were mainly altered in a lateral location with subepicardial myocardial involvement mainly at the mid-cavity. No significant differences in morphological or functional parameters were observed between the two study groups. Conclusions: Our results showed differences in the localization and distribution of myocardial tissue damage assessed by CMR among forms of AM accompanied by an infarct-like clinical presentation compared with non-infarct-like presentations of AM. The mechanisms underlying the different preferential sites of damage observed in our study are not known, and we do not exclude the possibility of their prognostic implications.
Features of Myocarditis: Morphological Differential Diagnosis in Post-COVID-19 Children
Authors: Karev Vadim , Starshinova Anastasia Ya , Glushkova Anzhela , Kudlay Dmitry , Starshinova Anna
Published: July 2023

Myocarditis is characterized by dysfunction and destruction of cardiomyocytes, infiltrative inflammation, and development of fibrosis. Late diagnosis of myocarditis has been a serious global health problem, especially due to the spread of a new coronavirus infection. The aim of this review is to identify differences between myocarditis of viral etiology, including SARS-CoV-2 lesions, based on instrumental and pathomorphological findings. Material and Methods: We analyzed publications covering the period from December 2019 to May 2023, published in publicly accessible international databases (“Medline”, “PubMed”, “Scopus”), with queries for the keywords “myocarditis”, “children”, “cardiovascular inflammation”, “COVID-19”, “SARS-CoV-2”, “severe acute respiratory syndrome coronavirus 2”, “differential diagnosis”. Results: It was found that no unambiguous morphological criteria for the diagnosis of myocarditis coupled to SARS-CoV-2 lesions were identified. However, the detected histopathological changes such as virus-associated degeneration, apoptosis, cardiomyocyte necrosis, moderate interstitial hyperemia, myocardial tissue oedema, and capillary endothelial cell dysfunction were the major markers of SARS-CoV-2 infection. Conclusion: It is necessary further reconsider morphological criteria to diagnose SARS-CoV-2-caused myocarditis, rather than solely relying on detecting viral RNA by PCR as the sole evidence-based criterion. Similar issues accompany diagnostics of myocardial lesions associated with other viral infections. Evidence for an etiological diagnosis of myocarditis can be provided by a comprehensive analysis of the diagnostic criteria obtained, confirming virus exposure, followed by development of distinct clinical symptoms, MRI and CT changes, and morphological criteria.
Investigation of Different Library Preparation and Tissue of Origin Deconvolution Methods for Urine and Plasma cfDNA Methylome Analysis
Authors: Kueng Nicholas , Sidler Daniel , Banz Vanessa , Largiadèr Carlo R. , Ng Charlotte K. Y. , Amstutz Ursula
Published: July 2023

Methylation sequencing is a promising approach to infer the tissue of origin of cell-free DNA (cfDNA). In this study, a single- and a double-stranded library preparation approach were evaluated with respect to their technical biases when applied on cfDNA from plasma and urine. Additionally, tissue of origin (TOO) proportions were evaluated using two deconvolution methods. Sequencing cfDNA from urine using the double-stranded method resulted in a substantial within-read methylation bias and a lower global methylation (56.0% vs. 75.8%, p ≤ 0.0001) compared to plasma cfDNA, both of which were not observed with the single-stranded approach. Individual CpG site-based TOO deconvolution resulted in a significantly increased proportion of undetermined TOO with the double-stranded method (urine: 32.3% vs. 1.9%; plasma: 5.9% vs. 0.04%; p ≤ 0.0001), but no major differences in proportions of individual cell types. In contrast, fragment-level deconvolution led to multiple cell types, with significantly different TOO proportions between the two methods. This study thus outlines potential limitations of double-stranded library preparation for methylation analysis of cfDNA especially for urinary cfDNA. While the double-stranded method allows jagged end analysis in addition to TOO analysis, it leads to significant methylation bias in urinary cfDNA, which single-stranded methods can overcome.
Tassel-YOLO: A New High-Precision and Real-Time Method for Maize Tassel Detection and Counting Based on UAV Aerial Images
Authors: Pu Hongli , Chen Xian , Yang Yiyu , Tang Rong , Luo Jinwen , Wang Yuchao , Mu Jiong
Published: July 2023

Tassel is an important part of the maize plant. The automatic detection and counting of tassels using unmanned aerial vehicle (UAV) imagery can promote the development of intelligent maize planting. However, the actual maize field situation is complex, and the speed and accuracy of the existing algorithms are difficult to meet the needs of real-time detection. To solve this problem, this study constructed a large high-quality maize tassel dataset, which contains information from more than 40,000 tassel images at the tasseling stage. Using YOLOv7 as the original model, a Tassel-YOLO model for the task of maize tassel detection is proposed. Our model adds a global attention mechanism, adopts GSConv convolution and a VoVGSCSP module in the neck part, and improves the loss function to a SIoU loss function. For the tassel detection task, the mAP@0.5 of Tassel-YOLO reaches 96.14%, with an average prediction time of 13.5 ms. Compared with YOLOv7, the model parameters and computation cost are reduced by 4.11 M and 11.4 G, respectively. The counting accuracy has been improved to 97.55%. Experimental results show that the overall performance of Tassel-YOLO is better than other mainstream object detection algorithms. Therefore, Tassel-YOLO represents an effective exploration of the YOLO network architecture, as it satisfactorily meets the requirements of real-time detection and presents a novel solution for maize tassel detection based on UAV aerial images.
A Modified Model-Free Adaptive Control Method for Large-Scale Morphing Unmanned Vehicles
Authors: Che Haohui , Chen Jun , Bai Guanghui , Wang Jianying
Published: July 2023

This paper investigates the attitude control problem for large-scale morphing unmanned vehicles. Considering the rapid time-varying and strong aerodynamic interference caused by large-scale morphing, a modified model-free control method utilizing only the system input and output is proposed. Firstly, a two-loop equivalent data model for the morphing unmanned vehicle is developed, which can better reflect the practical dynamics of morphing unmanned vehicles compared to the traditional compact form dynamic linearization data model. Based on the proposed data model, a modified model-free adaptive control (MMFAC) scheme is proposed, consisting of an external-loop and an inner-loop controller, so as to generate the required combined control torques. Additionally, in light of the aerodynamic uncertainties of the large-scale morphing unmanned vehicle, a rudder deflection actuator control scheme is designed by employing the model-free adaptive control approach. Finally, the boundedness of the closed-loop system and the convergence of tracking errors are guaranteed, based on the stability analysis. Additionally, numerical examples are presented to demonstrate the effectiveness and robustness of the proposed control scheme in the case of the effect of large-scale morphing.
Research on the Model Predictive Trajectory Tracking Control of Unmanned Ground Tracked Vehicles
Authors: Wang Shuai , Guo Jianbo , Mao Yiwei , Wang Huimin , Fan Jiaxin
Published: July 2023

This article summarizes the research significance and the development status of the unmanned ground tracked vehicles (UGTVs). According to the speed and steering principle of the UGTVs in plane motion, the kinematic state space equation of the vehicle is established. Based on the model predictive control (MPC), the UGTVs trajectory tracking controller is also established. After introducing the overall control system solution, based on the vehicle model, the track speed on both sides is used as the control input to solve the predicted output of the system. After constraining the control amount, the model prediction controller is established by using S function. Several simulations with different preset speeds are performed under linear conditions, and the numerical simulation with different prediction time domains and control time domains are performed under continuous curves. The test validates the effectiveness of the controller, and the effects of speed and time domain parameters on the deviation are analyzed based on the results. Based on satellite positioning technology, trajectory tracking tests of the UGTVs are carried out. After analyzing the positioning principle and common errors, the real-time kinematic technology is used to improve the positioning accuracy of the vehicle prototype. The hardware of the test platform includes a data acquisition system, a control execution system and a walking execution system, and the software part includes data processing and optimization control. The trajectory tracking experiments under different driving conditions are conducted, and the results show that the navigation tracking system can achieve good tracking performance.
Optimization of Flow Channel Design with Porous Medium Layers in a Proton Exchange Membrane Electrolyzer Cell
Authors: Chen Wei-Hsin , Wang Yaun-Sheng , Chang Min-Hsing , Jin Liwen , Saw Lip Huat , Lin Chih-Chia , Huang Ching-Ying
Published: July 2023

This study aims to optimize the flow channel design for a proton exchange membrane electrolyzer cell (PEMEC) to minimize the pressure drop across the cell. The pattern of parallel flow channels is considered with a dual-porous layer structure sandwiched between the flow channel plate and the catalyst layer. Four geometric factors are considered in the optimization analysis, including the width of the flow channel, the depth of the flow channel, the particle diameter of the large-pore porous layer, and the particle diameter of the small-pore porous layer. Computational fluid dynamics (CFD) is used to simulate the flow field, and based on the results of the CFD simulation, the Taguchi method is employed to analyze the optimal flow channel design. The importance of the factors is further analyzed by the analysis of variance (ANOVA) method. Three inlet velocities are assigned in the Taguchi analysis, which are 0.01, 0.1332, and 0.532 m/s, and then an orthogonal array is constructed and analyzed for each inlet flow condition. It is found that the optimal combination of the factors is the depth of the flow channel 1 mm, the width of the flow channel 3 mm, the particle diameter of the large-pore porous layer 0.212 mm, and the particle diameter of the small-pore porous layer 0.002 mm. The pressure drop across the PEMEC is minimized at the condition with the optimal combination of the factors. The ANOVA analysis shows that the depth of the flow channel exhibits the most significant impact on the pressure drop, while the other factors play minor roles only.
Optimized Power and Capacity Configuration Strategy of a Grid-Side Energy Storage System for Peak Regulation
Authors: Guo Feng , Li Jian , Zhang Chi , Zhu Yizhi , Yu Caiyang , Wang Qingsong , Buja Giuseppe
Published: July 2023

The optimal configuration of the rated capacity, rated power and daily output power is an important prerequisite for energy storage systems to participate in peak regulation on the grid side. Economic benefits are the main reason driving investment in energy storage systems. In this paper, the relationship between the economic indicators of an energy storage system and its configuration is first analyzed, and the optimization objective function is formulated. Then, according to the objective limitations of the energy storage system configuration and operation, the constraints are formulated. A set of typical parameters is selected, and the CPLEX (IBM ILOG CPLEX Optimization Studio) solver is used in MATLAB to solve the optimal configuration results. Several sets of optimization results are obtained by taking different subjective coefficient β values, and the economic and social benefits of the optimization results are analyzed. When the economic benefits of the energy storage system are more important, the value of β needs to be smaller, such as a value of 1000. Conversely, when the peak-regulation effect is more important, the value of β should be larger. Finally, configuration results of the control groups are given, and the effect of optimizing the calculation for improving economic benefits is verified.
The Lean-Burn Limit Extending Experiment on Gasoline Engine with Dual Injection Strategy and High Power Ignition System
Authors: Li Zhiqiang , Qin Jing , Pei Yiqiang , Zhong Kai , Zhang Zhiyong , Sun Jian
Published: July 2023

In the context of the energy crisis and global warming, improving thermal efficiency is the most important issue in research on gasoline engines, and lean mixture combustion strategy is becoming the most promising method. Thus, a high compression ratio, a high-power interval ignition system, and a stratified combustion scheme achieved via dual injection were novelly adopted in a single cylinder gasoline engine in this study. The results show that the lean combustion limit could be literally extended and improved thermal efficiency was observed under the ultra-lean condition. Meanwhile, reverse combustion performance trends were observed by altering the second injection proportion from 30% to 45% under the lean condition (λ = 1.6) and ultra-lean condition (λ = 1.9). This was related to a combustion velocity change caused by great concentration gradient at the middle and end combustion stage. Finally, according to research on the effects of altering the timing of the second injection, it is clear that the dual injection strategy is an ideal method for realizing operation under the lean condition (λ = 1.6). But for the operation under the ultra-lean condition (λ = 1.9), more injection times and suitable air flow organization are needed to enhance the robustness of mixture distribution.
NOx Emission Limits in a Fuel-Flexible and Defossilized Industry—Quo Vadis?
Authors: Schmitz Nico , Sankowski Lukas , Busson Elsa , Echterhof Thomas , Pfeifer Herbert
Published: July 2023

The reduction of CO2 emissions in hard-to-abate industries is described in several proposals on the European and National levels. In order to meet the defined goals, the utilization of sustainable, non-fossil fuels for process heat generation in industrial furnaces needs to be intensified. The focus mainly lies on hydrogen (H2) and its derivates. Furthermore, biofuels, e.g., dimethyl ether (DME), are considered. Besides possible changes in the process itself when substituting natural gas (NG) with alternative fuels, the emission of nitrogen oxides (NOx) is a major topic of interest. In current European standards and regulations, the NOx emissions are specified in mg per m3 of dry off-gas and refer to a reference oxygen concentration. Within this study, this limit specification is investigated for its suitability for the use of various fuel-oxidizer combinations in industrial combustion applications. Natural gas is used as a reference, while hydrogen and DME are considered sustainable alternatives. Air and pure oxygen (O2) are considered oxidizers. It is shown that the current specification, which is built on the use of fossil fuels, leads to non-comparable values for alternative fuels. Therefore, alternative NOx limit definitions are discussed in detail. The most suitable alternative was found to be mg per kWh. This limit specification is finally being investigated for its compliance with current regulations on various aspects of Continuous Emission Monitoring Systems.
Model of Residence Time Distribution, Degree of Mixing and Degree of Dispersion in the Biomass Transport Process on Various Grate Systems
Authors: Jaworski Tomasz , Wajda Agata , Kus Łukasz
Published: July 2023

Biomass includes diverse raw materials of plant or animal origin that are biodegradable. It also constitutes a significant fraction of municipal waste burned in waste incineration plants. Grate technology is one of the more commonly used technologies in the thermal conversion of biomass. The mass transport of material on the grate is a complex issue. The article presents a model for determining selected mass flow parameters on the grate, primarily the distribution of residence time, degree of mixing, and dispersion. The model is a description of mechanical mass transport on the grates of thermal waste conversion devices and represents the kinetics of the processes occurring on the grate. It allows for the design of the details of the specific movement of the material particles on the grates depending on their size and density. In addition, experimental tests of flow parameters realized on a laboratory stand simulating the operation of the grate are presented. Tests were conducted on different types of grates and with selected types of biomass materials. They included variants of the operating parameters of the grates, such as the speed and pitch of the grates an their inclination, simultaneously with the fulfillment of the 1:1 scale condition of the size of the laboratory stand to the actual size of the industrial grate (its section). A general trend can be seen in the mean residence time of the material on the grate, which is higher in the case of a reciprocating grate. The degree of dispersion is mainly influenced for moving and reciprocating grates by the inclination angle of the grate. The analysis of the test results made it possible to clarify the mechanism of material mass transport on different types of grates. It is also proposed to use the results in modeling the process of biomass combustion in grate chambers as well as their design and operation.