bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological, Genetic and Biochemical Evaluation of Dasypyrum villosum (L.) P. Candargy in the Gene Bank Collection
Authors: Holubec Vojtěch , Dvořáček Václav , Svobodová Leišová Leona , Ercisli Sezai
Published: June 2021

The Dasypyrum villosum gene bank collection, comprising 32 accessions, was characterized morphologically and genetically for resistance to leaf diseases and for quality parameters of seeds with specific accent to protein polymorphism and protein and starch composition. The collected material represented nearly the whole distribution area in the Mediterranean. For SSR analysis, a set of 40 SSR markers for wheat was selected. A matrix of distances between genotypes was calculated using Simple Matching dissimilarity coefficient in the DARwin software. The collection was scored for resistance to powdery mildew, brown, stripe and stem rusts. A modified SDS-PAGE method with clear interpretation of high and low molecular glutenin subunits (HMW, LMW) was used for characterization of accessions. Morphological phenotyping revealed considerable diversity allowing the distinguishing of clusters tracing the geographical origin of accessions. Genetic diversity showed three groups but without significant bootstrap support. All tested accessions were resistant to the applied races of powdery mildew and leaf rust. Three accessions were moderately susceptible to currently available races of yellow rust. Biochemical analyses of seeds in selected populations showed a high content of crude proteins with a significant proportion of prolamins and Ʃglutelins. The SDS-PAGE of HMW and LMW glutelins confirmed both the high population polymorphism and the intra-population differences. Apart from the recent research in CWR breeding, Dasypyrum villosum is still an underrepresented species in germplasm collections and an underutilized species in breeding.
Nitrogen and Phosphorus Accumulation in Horizontal Subsurface Flow Constructed Wetland
Authors: Jakubaszek Anita
Published: June 2021

The article presents the results of studies aimed at determining the level of accumulation of total nitrogen and total phosphorus in parts of reeds (Phragmites australis (Cav.) Trin. ex Steud.), as well as in a constructed wetland bed. The influence of the vegetative phase and dormancy of plants on the level of accumulation of biogenes in plant parts and in the bed of constructed wetland was investigated. Young plants at the stage of intensive growth were found to contain the most total nitrogen and total phosphorus. The leaves of the common reed, on the other hand, revealed the highest ability for the phytoaccumulation of nitrogen (32.21 gN/kg d.m.). Accumulation of total phosphorus in the leaves of reeds was, on average 1.54 gP/kg d.m. The results of studies on the filtration material filling the beds showed that the surface layer of up to 20 cm in depth was characterized by the highest total nitrogen content and total phosphorus content (average: 12.53 gN/kg d.m. and 3.01 gP/kg d.m.). The accumulation of these compounds decreased along with the depth of the deposit as well as in the direction of the outflow of sewage from the constructed wetland.
Beyond the Lactate Paradox: How Lactate and Acidity Impact T Cell Therapies against Cancer
Authors: Tu Violet Y. , Ayari Asma , O’Connor Roddy S.
Published: June 2021

T cell therapies, including CAR T cells, have proven more effective in hematologic malignancies than solid tumors, where the local metabolic environment is distinctly immunosuppressive. In particular, the acidic and hypoxic features of the tumor microenvironment (TME) present a unique challenge for T cells. Local metabolism is an important consideration for activated T cells as they undergo bursts of migration, proliferation and differentiation in hostile soil. Tumor cells and activated T cells both produce lactic acid at high rates. The role of lactic acid in T cell biology is complex, as lactate is an often-neglected carbon source that can fuel TCA anaplerosis. Circulating lactate is also an important means to regulate redox balance. In hypoxic tumors, lactate is immune-suppressive. Here, we discuss how intrinsic- (T cells) as well as extrinsic (tumor cells and micro-environmental)-derived metabolic factors, including lactate, suppress the ability of antigen-specific T cells to eradicate tumors. Finally, we introduce recent discoveries that target the TME in order to potentiate T cell-based therapies against cancer.
Antibiogram Development in the Setting of a High Frequency of Multi-Drug Resistant Organisms at University Teaching Hospital, Lusaka, Zambia
Authors: Roth Brenna M. , Laps Alexandra , Yamba Kaunda , Heil Emily L. , Johnson J. Kristie , Stafford Kristen , Hachaambwa Lottie M. , Kalumbi Mox , Mulenga Lloyd , Patel Devang M. , Claassen Cassidy W.
Published: June 2021

Antimicrobial resistance is a global challenge requiring reliable surveillance data collection and use. Prior studies on resistance in Zambia depended on laboratory methods with limited standardization. Since 2015, the University Teaching Hospital (UTH) microbiology laboratory has used the Vitek 2 Compact (bioMerieux, Inc., Marcy-l’Étoile, France) for standardized identification and susceptibility testing. We conducted a cross-sectional study of 2019 bacterial isolates collected from July 2015 to April 2017 to identify bacterial causes of infections, their susceptibility to commonly used antibiotics at UTH, and develop hospital antibiograms with a multidisciplinary team using World Health Organization guidance. We found high levels of antibiotic resistance among Gram negative bacteria. Escherichia coli and Klebsiella pneumoniae were highly resistant to all antibiotics except amikacin and carbapenems. E. coli had susceptibilities of 42.4% to amoxicillin/clavulanic acid, 41.4% to ceftriaxone, 40.2% to ciprofloxacin, and 10.4% to trimethoprim/sulfamethoxazole (TMP/SMX). K. pneumoniae had susceptibilities of 20.7% to amoxicillin/clavulanic acid, 15.6% to ceftriaxone, 48.5% to ciprofloxacin, and 12.3% to TMP/SMX. The high resistance to 3rd generation cephalosporins indicates high rates of beta-lactamase production. This is information that clinicians need to inform clinical decision making and choice of empiric antibiotics and that UTH requires to inform antimicrobial stewardship such as improvements in antibiotic use.
Effects of Serine or Threonine in the Active Site of Typical 2-Cys Prx on Hyperoxidation Susceptibility and on Chaperone Activity
Authors: Tairum Carlos A. , Santos Melina Cardoso , Breyer Carlos Alexandre , de Oliveira Ana Laura Pires , Cabrera Vitoria Isabela Montanhero , Toledo-Silva Guilherme , Mori Gustavo Maruyama , Toyama Marcos Hikari , Netto Luis Eduardo Soares , de Oliveira Marcos Antonio
Published: June 2021

Typical 2-Cys peroxiredoxins (2-Cys Prx) are ubiquitous Cys-based peroxidases, which are stable as decamers in the reduced state, and may dissociate into dimers upon disulfide bond formation. A peroxidatic Cys (CP) takes part of a catalytic triad, together with a Thr/Ser and an Arg. Previously, we described that the presence of Ser (instead of Thr) in the active site stabilizes yeast 2-Cys Prx as decamers. Here, we compared the hyperoxidation susceptibilities of yeast 2-Cys Prx. Notably, 2-Cys Prx containing Ser (named here Ser-Prx) were more resistant to hyperoxidation than enzymes containing Thr (Thr-Prx). In silico analysis revealed that Thr-Prx are more frequent in all domains of life, while Ser-Prx are more abundant in bacteria. As yeast 2-Cys Prx, bacterial Ser-Prx are more stable as decamers than Thr-Prx. However, bacterial Ser-Prx were only slightly more resistant to hyperoxidation than Thr-Prx. Furthermore, in all cases, organic hydroperoxide inhibited more the peroxidase activities of 2-Cys Prx than hydrogen peroxide. Moreover, bacterial Ser-Prx displayed increased thermal resistance and chaperone activity, which may be related with its enhanced stability as decamers compared to Thr-Prx. Therefore, the single substitution of Thr by Ser in the catalytic triad results in profound biochemical and structural differences in 2-Cys Prx.
The Influence of Floor Layering on Airborne Sound Insulation and Impact Noise Reduction: A Study on Cross Laminated Timber (CLT) Structures
Authors: Bettarello Federica , Gasparella Andrea , Caniato Marco
Published: June 2021

The use of timber constructions recently increased. In particular, Cross Laminated Timber floors are often used in multi-story buildings. The development of standardization processes, product testing, design of details and joints, the speed of construction, and the advantages of eco-sustainability are the main reasons why these structures play a paramount role on the international building scene. However, for further developments, it is essential to investigate sound insulation properties, in order to meet the requirements of indoor comfort and comply with current building regulations. This work presents the results obtained by in field measurements developed using different sound sources (tapping machine, impact rubber ball, and airborne dodecahedral speaker) on Cross Laminated Timber floors, changing different sound insulation layering (suspended ceiling and floating floors). Results clearly show that the influence on noise reduction caused by different layering stimulated by diverse noise source is not constant and furthermore that no available analytical model is able to correctly predict Cross Laminated Timber floors acoustic performances.
Development of Variants of High-Performance Self-Compacting Concrete with Improved Resistance to the Attack of Sulfates
Authors: Terzijski Ivailo , Kocáb Dalibor , Štěpánek Petr , Strnad Jiří , Girgle František , Šimůnek Petr
Published: June 2021

This paper presents experimental and analytical work of which the main objective was to support the introduction of a new technology for the production of sewer pipes. In this technology, the pipes produced consist of two differently produced parts. The direct part uses conventional vibro press compacted concrete. In the curved part, on the other hand, self-compacting concrete technology is used. The cooperating company, Prefa Brno a.s., defined possible negative effects on concrete of sewer pipes. The task of the research team and now the author’s team was to propose a procedure for the development of suitable self-compacting concrete variants and subsequently the design of a methodology to verify their durability in aqueous environments containing sulfates. To increase the efficiency of the development, the model mortar method was used in the experimental work. That is, instead of the original concrete, a model mortar derived from it was tested. The principle and procedure of derivation of model mortars are described in the paper. In total, eight variants of model mortars were tested, and at least three of them fulfilled the requirements. An optional but beneficial part of the carried out work was the derivation and practical application of the time-anchored-triangles-of-cracking graphical method developed during the research. This method is used to quickly compare the degree of attack of different silicate composites tested in a common bath inducing type III corrosion.
DC-DC Zeta Power Converter: Ramp Compensation Control Design and Stability Analysis
Authors: Angulo-García David , Angulo Fabiola , Muñoz Juan-Guillermo
Published: June 2021

The design of robust and reliable power converters is fundamental in the incorporation of novel power systems. In this paper, we perform a detailed theoretical analysis of a synchronous ZETA converter controlled via peak-current with ramp compensation. The controller is designed to guarantee a stable Period 1 orbit with low steady state error at different values of input and reference voltages. The stability of the desired Period 1 orbit of the converter is studied in terms of the Floquet multipliers of the solution. We show that the control strategy is stable over a wide range of parameters, and it only loses stability: (i) when extreme values of the duty cycle are required; and (ii) when input and reference voltages are comparable but small. We also show by means of bifurcation diagrams and Lyapunov exponents that the Period 1 orbit loses stability through a period doubling mechanism and transits to chaos when the duty cycle saturates. We finally present numerical experiments to show that the ramp compensation control is robust to a large set of perturbations.
Immediate Insulin Treatment Prevents Diabetes-Induced Gut Region-Specific Increase in the Number of Myenteric Serotonergic Neurons
Authors: Mezei Diána , Bódi Nikolett , Szalai Zita , Márton Zsuzsanna , Balázs János , Bagyánszki Mária
Published: June 2021

To evaluate the effects of hyperglycemia and insulin treatment on the proportion of serotonin-immunoreactive (5-HT-IR) myenteric neurons, samples were taken from the duodenum, ileum, and colon of diabetic, insulin-treated diabetic, and control rats 10 weeks after the onset of streptozotocin-induced hyperglycemia. Myenteric whole-mount preparations were immunostained with anti-5-HT and pan-neuronal anti-HuCD markers. In controls, the 5-HT-IR myenteric neurons represent a small proportion (~2.5%) of the total neuronal number in the investigated gut segments. The proportion of 5-HT-IR myenteric neurons was significantly higher in the duodenum (p < 0.01) and colon (p < 0.0001) of diabetic rats compared to the controls but exhibited a slight increase in the ileum. Immediate insulin treatment resulted in a significantly lower proportion of myenteric 5-HT-IR neurons in each segment (duodenum p < 0.0001; ileum p < 0.01; and colon p < 0.0001) compared to the untreated diabetics. Our study demonstrates that the proportion of 5-HT-IR myenteric neurons was enhanced in type 1 diabetes in a region-specific manner. Immediate insulin treatment prevents a higher hyperglycemia-induced amount of 5-HT-IR neurons and restores it to the control level in each investigated gut segment. Despite the low proportion of 5-HT-IR myenteric neurons, hyperglycemia-related changes of these neurons may play a crucial role in gastrointestinal symptoms in type 1 diabetes.
Design of Bipolar Optical Code-Division Multiple-Access Techniques Using Phase Modulator for Polarization Coding in Wireless Optical Communication
Authors: Wijanto Eddy , Huang Chun-Ming
Published: June 2021

In this study, a bipolar optical code-division multiple-access (Bi-OCDMA) technique based on spectral amplitude coding (SAC) was proposed by using a phase modulator to realize polarization coding through a free-space optical (FSO) channel. Various types of noise, such as amplified spontaneous emission (ASE) noise, thermal noise, and shot noise, were included in the simulation to approach the real application. The first simulation, utilizing a modified M-sequence as signature code, demonstrated that the proposed Bi-OCDMA system could be implemented in FSO communication. The proposed Bi-OCDMA scheme improves the transmission rate and power efficiency compared with the previous scheme. The structure of the proposed system alleviates multiple-access interference (MAI) with a simple and cost-effective design. The second simulation observed the performance of the proposed Bi-OCDMA for two users with several well-known SAC codes, i.e., multi-diagonal (MD) code, modified quadratic congruence (MQC) code, modified maximum length sequence (M-sequence) code, and Walsh–Hadamard code, in extreme weather conditions, both for additive white Gaussian noise (AWGN) and turbulence-induced fading channel. The simulation results indicated that the Walsh–Hadamard code has superior performance compared to other codes. The results show the MD code can be implemented in the proposed Bi-OCDMA scheme for a medium-distance FSO.
An Efficient Text Detection Model for Street Signs
Authors: Lu Manhuai , Mou Yuanxiang , Chen Chin-Ling , Tang Qiting
Published: June 2021

Text detection in natural scenes is a current research hotspot. The Efficient and Accurate Scene Text (EAST) detector model has fast detection speed and good performance but is ineffective in detecting long text regions owing to its small receptive field. In this study, we built upon the EAST model by improving the bounding box’s shrinking algorithm to make the model more accurate in predicting short edges of text regions; altering the loss function from balanced cross-entropy to Focal loss; improving the model’s learning ability on hard, positive examples; and adding a feature enhancement module (FEM) to increase the receptive field of the EAST model and enhance its detection ability for long text regions. The improved EAST model achieved better detection results on both the ICDAR2015 dataset and the Street Sign Text Detection (SSTD) dataset proposed in this paper. The precision and F1 scores of the model also demonstrated advantages over other models on the ICDAR2015 dataset. A comparison of the text detection effects between the improved EAST model and the EAST model showed that the proposed FEM was more effective in increasing the EAST detector’s receptive field, which indicates that it can improve the detection of long text regions.
Autonomous Mobile Robot Navigation in Sparse LiDAR Feature Environments
Authors: Nguyen Phuc Thanh-Thien , Yan Shao-Wei , Liao Jia-Fu , Kuo Chung-Hsien
Published: June 2021

In the industrial environment, Autonomous Guided Vehicles (AGVs) generally run on a planned route. Among trajectory-tracking algorithms for unmanned vehicles, the Pure Pursuit (PP) algorithm is prevalent in many real-world applications because of its simple and easy implementation. However, it is challenging to decelerate the AGV’s moving speed when turning on a large curve path. Moreover, this paper addresses the kidnapped-robot problem occurring in spare LiDAR environments. This paper proposes an improved Pure Pursuit algorithm so that the AGV can predict the trajectory and decelerate for turning, thus increasing the accuracy of the path tracking. To solve the kidnapped-robot problem, we use a learning-based classifier to detect the repetitive pattern scenario (e.g., long corridor) regarding 2D LiDAR features for switching the localization system between Simultaneous Localization And Mapping (SLAM) method and Odometer method. As experimental results in practice, the improved Pure Pursuit algorithm can reduce the tracking error while performing more efficiently. Moreover, the learning-based localization selection strategy helps the robot navigation task achieve stable performance, with 36.25% in completion rate more than only using SLAM. The results demonstrate that the proposed method is feasible and reliable in actual conditions.
Analyzing and Modeling of Water Transport Phenomena in Open-Cathode Polymer Electrolyte Membrane Fuel Cell
Authors: Yuan Wei-Wei , Ou Kai , Jung Seunghun , Kim Young-Bae
Published: June 2021

Water management is one issue that must be surpassed to ensure high membrane proton conductivity and adequate reactant transport in the membrane-electrode assembly (MEA) simultaneously. A well-designed water management system is based on a comprehensive understanding of water transport in the inner part of the polymer electrolyte membrane (PEM) fuel cell. In this work, the water transport phenomena in the MEA PEM fuel cell are analyzed by using a mathematical model. The transport of diluted species interface is used to model the transport of water in the ionomer phase in the catalytic layer and the membrane domains. The molecular flux of water is defined using Nernst–Planck equations, including migration and Fickian diffusion using parameters obtained experimentally for diffusivity and mobility based on water drag for a fully humidified membrane. The proposed model 1D model includes anode gas channel, cathode gas channel, anode gas diffusion layer (GDL), cathode GDL, anode catalyst layer, cathode catalyst layer, and proton exchange membrane. Water activity, ionomer conductivity, and output voltage are predicted by changing the humidity on the anode side of the fuel cell.
Advisory and Knowledge Transfer Tool for Ammonia Emission Mitigation on Pig Farms in Hungary
Authors: Magyar Marianna , Pirkó Béla , Seenger Julianna Kótiné , Baranyai Nóra Hegedűsné , Dublecz Károly , Vojtela Tibor , Rák Renáta , Borka György , Szabó Anita , Benedek Zsuzsanna
Published: June 2021

The Ammonia Gas Emission Model for Swine (AGEM-S), a nitrogen flow model, was created with the objective of assisting in the reduction of ammonia emissions in the Hungarian pig sector. Regarding the applied technological processes and considering the factors that influence ammonia emissions, the model quantifies the amount of ammonia emissions of pig farming in all stages (feeding, housing technology, manure storage, and application in the field). The aim of the project was to create a system that performs general calculations using the input data used by practicing farmers, without compromising the information content of the output data. Using this system, the input parameters can be entered as simply as possible and in the shortest possible time. In addition to demonstrating the impact of ammonia emission reduction measures to farmers from an integrated N management approach, AGEM-S has the potential to support the transfer of emission reduction technologies and practices at the farm level as a knowledge transfer tool primarily, but also as a decision support tool for technological change.
Phase Compensation Technique for Effective Heat Focusing in Microwave Hyperthermia Systems
Authors: Lim Seonho , Yoon Young Joong
Published: June 2021

In this paper, effective electromagnetic (EM) focusing achieved with a phase compensation technique for microwave hyperthermia systems is proposed. To treat tumor cells positioned deep inside a human female breast, EM energy must be properly focused on the target area. A circular antenna array for microwave hyperthermia allows EM energy to concentrate on a specific target inside the breast tumor. Depending on the cancerous cell conditions in the breast, the input phases of each antenna are calculated for single and multiple tumor cell locations. In the case of multifocal breast cancer, sub-array beam focusing via the phase compensation technique is presented to enhance the ability of EM energy to concentrate on multiple targets while minimizing damage to normal cells. To demonstrate the thermal treatment effects on single and multiple tumor locations, the accumulation of the specific absorption rate (SAR) parameter and temperature changes were verified using both simulated and experimental results.
Seismic Vulnerability Assessment of Historical Masonry Buildings in Croatian Coastal Area
Authors: Nikolić Željana , Runjić Luka , Ostojić Škomrlj Nives , Benvenuti Elena
Published: June 2021

(1) Background: The protection of built heritage in historic cities located in seismically active areas is of great importance for the safety of inhabitants. Systematic care and planning are necessary to detect the seismic vulnerability of buildings, in order to determine priorities in rehabilitation projects and to continuously provide funds for the reconstruction of the buildings. (2) Methods: In this study, the seismic vulnerability of the buildings in the historic center of Kaštel Kambelovac, a Croatian settlement located along the Adriatic coast, has been assessed through an approach based on the calculation of vulnerability indexes. The center consists of stone masonry buildings built between the 15th and 19th centuries. The seismic vulnerability method was derived from the Italian GNDT approach, with some modifications resulting from the specificity of the buildings in the investigated area. A new damage–vulnerability–peak ground acceleration relation was developed using the vulnerability indexes and the yield and collapse accelerations of buildings obtained through non-linear static analysis. (3) Results: A seismic vulnerability map, critical peak ground accelerations for early damage and collapse states, and damage index maps for two return periods have been predicted using the developed damage curves. (4) Conclusions: The combination of the vulnerability index method with non-linear pushover analysis is an effective tool for assessing the damage of a building stock on a territorial scale.
The Combined-Unified Hybrid Censored Samples from Pareto Distribution: Estimation and Properties
Authors: Sultan Khalaf S. , Emam Walid
Published: June 2021

In this paper, we use the combined-unified hybrid censoring samples to obtain the maximum likelihood estimates of the unknown parameters, survival, and hazard functions of Pareto distribution. Next, we discuss some efficiency criteria of the maximum likelihood estimators, including; the unbiasedness, consistency, and sufficiency. Additionally, we use MCMC to obtain the Bayesian estimates of the unknown parameters. In addition, we calculate the intervals estimation of the unknown parameters. Finally, we analyze a set of real data in view of the theoretical findings of the paper.
GA-Based Optimization Method for Mobile Crane Repositioning Route Planning
Authors: Gwak Han-Seong , Lee Hong-Chul , Choi Byoung-Yoon , Mi Yirong
Published: June 2021

Mobile cranes have been used extensively as essential equipment at construction sites. The productivity improvement of the mobile crane affects the overall productivity of the construction project. Hence, various studies have been conducted regarding mobile crane operation planning. However, studies on solving RCP (the repositioning mobile crane problem) are insufficient. This article presents a mobile crane reposition route planning optimization method (RPOS) that minimizes the total operating time of mobile crane. It converts the construction site into a mathematical model, determines feasible locations of the mobile crane, and identifies near-global optimal solution (s) (i.e., the placement point sequences of mobile crane) by implementing genetic algorithm and dijkstra’s algorithm. The study is of value to practitioners because RPOS provides an easy-to-use computerized tool that reduces the lengthy computations relative to data processing and Genetic Algorithms (GAs). Test cases verify the validity of the computational method.
Ceramic Cracks Segmentation with Deep Learning
Authors: Junior Gerivan Santos , Ferreira Janderson , Millán-Arias Cristian , Daniel Ramiro , Junior Alberto Casado , Fernandes Bruno J. T.
Published: June 2021

Cracks are pathologies whose appearance in ceramic tiles can cause various damages due to the coating system losing water tightness and impermeability functions. Besides, the detachment of a ceramic plate, exposing the building structure, can still reach people who move around the building. Manual inspection is the most common method for addressing this problem. However, it depends on the knowledge and experience of those who perform the analysis and demands a long time and a high cost to map the entire area. This work focuses on automated optical inspection to find faults in ceramic tiles performing the segmentation of cracks in ceramic images using deep learning to segment these defects. We propose an architecture for segmenting cracks in facades with Deep Learning that includes an image pre-processing step. We also propose the Ceramic Crack Database, a set of images to segment defects in ceramic tiles. The proposed model can adequately identify the crack even when it is close to or within the grout.
Influence of Biopreparations on Soil and Crop Residue Properties, Traction Force of Machines in Shallow Tillage
Authors: Lekavičienė Kristina , Naujokienė Vilma , Šarauskis Egidijus , Jasinskas Algirdas
Published: June 2021

Solving traction force and energy consumption problem in crop production, the use of strategically selected bioproducts can change the physical properties of the soil and influence changes in the traction force during tillage technological operations. The aim of this work was to investigate the influence of different biopreparations on the physical properties of the soil, winter wheat residues and the machine traction force during shallow tillage. In spring, after the resumption of winter wheat vegetation, seven different biopreparations and their mixtures were used. In autumn, after the harvest, studies of plant residues and soil porosity and density were performed prior to shallow tillage. The traction force of the tractor when working the soil shallowly was determined at 3 driving velocities—8, 10 and 12 km h−1. Research has shown a positive effect of biopreparations on the total porosity, density, and traction force of the machine. However, biopreparations did not significantly affect the cutting force of winter wheat residues. Biopreparations can reduce the traction force in shallow tillage due positive changes soil properties.
The European Beech Annual Tree Ring Widths Time Series, Solar–Climatic Relationships and Solar Dynamo Regime Changes
Authors: Komitov Boris
Published: June 2021

In this study, the results from the analysis of annual ring widths (‘Dm’) time series of two “very sensitive” to the climate and solar–climate relationships of long lived European beech (Fagus sylvatica) samples (on age of 209 ± 1 and 245 ± 5 years correspondingly) are discussed. Both series are characterized by very good expressed and relating to the solar magnetic Hale cycle 20–22-year oscillations. A good coincidence between the changes of ‘Dm’ and the growth or fading of the solar magnetic cycle is found. The transition effects at the beginning and ending of the grand Dalton (1793–1833) and Gleissberg minima (1898–1933) are very clearly visible in the annual tree ring width data for the one of beech samples. Some of these effects are also detected in the second sample. The problem for the possible “lost” sunspot cycle at the end of 18th century is also discussed. A prediction for a possible “phase catastrophe” during the future Zurich sunspot cycles 26 and 27 between 2035–2040 AD as well as for general precipitation upward and temperature fall tendencies in Central Bulgaria, more essential after 2030 AD, are brought forth.
Mathematical Analysis of a Fractional COVID-19 Model Applied to Wuhan, Spain and Portugal
Authors: Ndaïrou Faïçal , Torres Delfim F. M.
Published: June 2021

We propose a qualitative analysis of a recent fractional-order COVID-19 model. We start by showing that the model is mathematically and biologically well posed. Then, we give a proof on the global stability of the disease free equilibrium point. Finally, some numerical simulations are performed to ensure stability and convergence of the disease free equilibrium point.
Bioengineering Progress in Lung Assist Devices
Authors: Syed Ahad , Kerdi Sarah , Qamar Adnan
Published: June 2021

Artificial lung technology is advancing at a startling rate raising hopes that it would better serve the needs of those requiring respiratory support. Whether to assist the healing of an injured lung, support patients to lung transplantation, or to entirely replace native lung function, safe and effective artificial lungs are sought. After 200 years of bioengineering progress, artificial lungs are closer than ever before to meet this demand which has risen exponentially due to the COVID-19 crisis. In this review, the critical advances in the historical development of artificial lungs are detailed. The current state of affairs regarding extracorporeal membrane oxygenation, intravascular lung assists, pump-less extracorporeal lung assists, total artificial lungs, and microfluidic oxygenators are outlined.
Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific
Authors: Xu Yu , Zhan Zifeng , Xu Kuidong
Published: June 2021

Members of genus Iridogorgia Verrill, 1883 are the typical deep-sea megabenthos with only seven species reported. Based on an integrated morphological-molecular approach, eight sampled specimens of Iridogorgia from seamounts in the tropical Western Pacific are identified as three new species, and two known species I. magnispiralis Watling, 2007 and I. densispicula Xu, Zhan, Li and Xu, 2020. Iridogorgia flexilis sp. nov. is unique in having a very broad polyp body base with stout and thick scales. Iridogorgia densispiralis sp. nov. can be distinguished by rods present in both polyps and coenenchyme, and I. verrucosa sp. nov. is characterized by having numerous verrucae in coenenchyme and irregular spindles and scales in the polyp body wall. Phylogenetic analysis based on the nuclear 28S rDNA indicated that I. densispiralis sp. nov. showed close relationships with I. splendens Watling, 2007 and I. verrucosa sp. nov., and I. flexilis sp. nov. formed a sister clade with I. magnispiralis. In addition, due to Rhodaniridogorgia fragilis Watling, 2007 nested into the Iridogorgia clade in mtMutS-COI trees and shared highly similar morphology to the latter, we propose to eliminate the genus Rhodaniridogorgia by establishing a new combination Iridogorgia fragilis (Watling, 2007) comb. nov. and resurrecting I. superba Nutting, 1908.
Label-Free Single Cell Viability Assay Using Laser Interference Microscopy
Authors: Beloglazova Yulia , Nikitiuk Aleksandr , Voronina Anna , Gagarskikh Olga , Bayandin Yuriy , Naimark Oleg , Grishko Victoria
Published: June 2021

Laser interference microscopy (LIM) is a promising label-free method for single-cell research applicable to cell viability assessment in the studies of mammalian cells. This paper describes the development of a sensitive and reproducible method for assessing cell viability using LIM. The method, based on associated signal processing techniques, has been developed as a result of real-time investigation in phase thickness fluctuations of viable and non-viable MCF-7 cells, reflecting the presence and absence of their metabolic activity. As evinced by the values of the variable vc, this variable determines the viability of a cell only in the attached state (vc exceeds 20 nm2 for viable attached cells). The critical value of the power spectrum slope βc of the phase thickness fluctuations equals 1.00 for attached MCF-7 cells and 0.71 for suspended cells. The slope of the phase fluctuations’ power spectrum for MCF-7 cells was determined to exceed the threshold value of βc for a living cell, otherwise the cell is dead. The results evince the power spectrum slope as the most appropriate indicator of cell viability, while the integrated evaluation criterion (vc and βc values) can be used to assay the viability of attached cells.
Effect of Cryotherapy Temperature on the Extension Performance of Healthy Adults’ Legs
Authors: Lu Yichen , He Yuqi , Ying Shanshan , Wang Qiaojun , Li Jianshe
Published: June 2021

Cryotherapy as a measurement of sports recovery and treatment has been utilized by more and more athletes and coaches. The aim of this study was to investigate the effect of different temperature cryotherapies on leg extension performance. Thirty-one male participants from a University volunteered to join two different temperature cryotherapies. The peak power and peak force of right leg extension performance of each participant was measured by Keiser, before and after cryotherapy, respectively. The results of this study show that there was a significant difference in peak power (t = −3.203, p value = 0.003) and peak force (t = −4.662, p value = 0) before and after 0 °C cryotherapy. In addition, there was a significant difference in peak force (t = −4.36, p value = 0) before and after −5 °C cryotherapy. Besides, the changing rates of peak power (3.03%) and peak force (11.51%) in the 0 °C group were higher than those of peak power (2.80%), as well as peak force (7.45%), in the −5 °C group. The PF in the 0 °C and −5 °C groups both significantly increased after cryotherapy. Peak power significantly increased after 0 °C cryotherapy, but did not significantly increase after −5 °C cryotherapy. The changing rates of peak power and peak force in the 0 °C group were both higher than the −5 °C group. A short period of cold treatment at 0 °C may increase the leg extension ability. A 0 °C cold therapy for a short period of time is more suitable than a −5 °C one for athletes to recover during the interval within a competition. Athlete and coach could choose an appropriate temperature to help increase performance of physical level and recovery.
Discovery of Novel GMPS Inhibitors of Candidatus Liberibacter Asiaticus by Structure Based Design and Enzyme Kinetic
Authors: Nan Jing , Zhang Shaoran , Zhan Ping , Jiang Ling
Published: June 2021

Citrus production is facing an unprecedented problem because of huanglongbing (HLB) disease. Presently, no effective HLB-easing method is available when citrus becomes infected. Guanosine 5′-monophosphate synthetase (GMPS) is a key protein in the de novo synthesis of guanine nucleotides. GMPS is used as an attractive target for developing agents that are effective against the patogen infection. In this research, homology modeling, structure-based virtual screening, and molecular docking were used to discover the new inhibitors against CLas GMPS. Enzyme assay showed that folic acid and AZD1152 showed high inhibition at micromole concentrations, with AZD1152 being the most potent molecule. The inhibition constant (Ki) value of folic acid and AZD1152 was 51.98 µM and 4.05 µM, respectively. These results suggested that folic acid and AZD1152 could be considered as promising candidates for the development of CLas agents.
Modulation of Stem Cell Progeny by Probiotics during Regeneration of Gastric Mucosal Erosions
Authors: Al-Yassir Farah , Khoder Ghalia , Sugathan Subi , Saseedharan Prashanth , Al Menhali Asma , Karam Sherif M.
Published: June 2021

Patients with gastric mucosal erosions are predisposed to chronic gastritis, ulcer or even cancer. The repair of mucosal erosions involves several events including proliferation of gastric epithelial stem cells. The aim of this study was to investigate the effects of the probiotic mixture of De Simone Formulation on gastric epithelial stem cell lineages in mouse models of gastric mucosal erosions. Gastric erosions were induced by a single oral gavage of 80% ethanol containing 15 mg/mL acetylsalicylic acid (5 mL/kg) following a daily dose of probiotic mixture (5 mg/day/mouse) for 10 days. In another protocol, erosions were induced by a daily gavage of acetylsalicylic acid (400 mg/kg/day/mouse) for 5 days before or after daily administration of probiotic mixture for 5 days. Control mice received water gavage for 10 days. All mice were injected with bromodeoxyuridine two hours before sacrifice to label S-phase cells. The stomachs of all mice were processed for histological examination, lectin binding, and immunohistochemical analysis. The results reveal that mice that received probiotics before or after the induction of erosion showed a decrease in erosion index with an increase in gastric epithelial stem/progenitor cell proliferation and enhanced production of mucus, trefoil factors, and ghrelin by mucous and enteroendocrine cell lineages. These mice also showed restoration of the amount of H+,K+-ATPase and pepsinogen involved in the production of the harsh acidic environment by parietal and chief cell lineages. In conclusion, this study demonstrates the beneficial effects of probiotics against gastric mucosal erosion and highlights the involvement and modulation of proliferative stem cells and their multiple glandular epithelial cell lineages.
Immunomodulatory Properties of Host Defence Peptides in Skin Wound Healing
Authors: Petkovic Marija , Mouritzen Michelle Vang , Mojsoska Biljana , Jenssen Håvard
Published: June 2021

Cutaneous wound healing is a vital biological process that aids skin regeneration upon injury. Wound healing failure results from persistent inflammatory conditions observed in diabetes, or autoimmune diseases like psoriasis. Chronic wounds are incurable due to factors like poor oxygenation, aberrant function of peripheral sensory nervature, inadequate nutrients and blood tissue supply. The most significant hallmark of chronic wounds is heavily aberrant immune skin function. The immune response in humans relies on a large network of signalling molecules and their interactions. Research studies have reported on the dual role of host defence peptides (HDPs), which are also often called antimicrobial peptides (AMPs). Their duality reflects their potential for acting as antibacterial peptides, and as immunodulators that assist in modulating several biological signalling pathways related to processes such as wound healing, autoimmune disease, and others. HDPs may differentially control gene regulation and alter the behaviour of epithelial and immune cells, resulting in modulation of immune responses. In this review, we shed light on the understanding and most recent advances related to molecular mechanisms and immune modulatory features of host defence peptides in human skin wound healing. Understanding their functional role in skin immunity may further inspire topical treatments for chronic wounds.
Plasma Rich in Growth Factors Promotes Autophagy in ARPE19 Cells in Response to Oxidative Stress Induced by Blue Light
Authors: Suárez-Barrio Carlota , del Olmo-Aguado Susana , García-Pérez Eva , Fernández-Vega-Cueto Luis , Fernández-Vega Cueto Andrés , Baamonde-Arbaiza Begoña , Fernández-Vega Luis , Merayo-Lloves Jesús
Published: June 2021

Age-related macular degeneration (AMD) causes the degeneration of photoreceptors and retinal cells leading to vision loss in older subjects. Among possible exogenous risk factors, it has been recently proposed that long-term exposure to blue light could aggravate the course of AMD. In the search for therapeutic options, plasma rich in growth factors (PRGF) has been shown to enhance cell antioxidant pathways and protect photoreceptors against the harm produced by blue light, although its mechanism of action remains unknown. One possible mechanism, autophagy, is one of the most conservative cell renewal systems used in eukaryotes to destroy cellular components that have been damaged by some kind of insult. The oxidative stress of exposure to blue light is known to induce cell autophagy. In this study, we examined the combined effects on autophagy of blue light and PRGF in a retinal cell line, ARPE19. In response to treatment with both PRGF and blue light, we detected the modulated expression of autophagy markers such as NF-kB, p62/sqstm1, Atg5, LC3 and Beclin1, and inflammatory markers such as IL1B and IL18. Our findings suggest that PRGF promotes cell autophagy in response to exposure to blue light.
Vocal Fold Fibroblasts in Reinke’s Edema Show Alterations Involved in Extracellular Matrix Production, Cytokine Response and Cell Cycle Control
Authors: Grill Magdalena , Lazzeri Isaac , Kirsch Andrijana , Steurer Nina , Grossmann Tanja , Karbiener Michael , Heitzer Ellen , Gugatschka Markus
Published: June 2021

The voice disorder Reinke’s edema (RE) is a smoking- and voice-abuse associated benign lesion of the vocal folds, defined by an edema of the Reinke’s space, accompanied by pathological microvasculature changes and immune cell infiltration. Vocal fold fibroblasts (VFF) are the main cell type of the lamina propria and play a key role in the disease progression. Current therapy is restricted to symptomatic treatment. Hence, there is an urgent need for a better understanding of the molecular causes of the disease. In the present study, we investigated differential expression profiles of RE and control VFF by means of RNA sequencing. In addition, fast gene set enrichment analysis (FGSEA) was performed in order to obtain involved biological processes, mRNA and protein levels of targets of interest were further evaluated. We identified 74 differentially regulated genes in total, 19 of which were upregulated and 55 downregulated. Differential expression analysis and FGSEA revealed upregulated genes and pathways involved in extracellular matrix (ECM) remodeling, inflammation and fibrosis. Downregulated genes and pathways were involved in ECM degradation, cell cycle control and proliferation. The current study addressed for the first time a direct comparison of VFF from RE to control and evaluated immediate functional consequences.
Optimization and Development of Albumin–Biopolymer Bioconjugates with Solubility-Improving Properties
Authors: Pápay Zsófia Edit , Magramane Sabrina , Király Márton , Szalkai Petra , Ludányi Krisztina , Horváth Péter , Antal István
Published: June 2021

Bioconjugation is an emerging field in the food and pharmaceutical industry. Due to its biocompatibility and high ligand binding capacity, albumin is widely used in modern drug delivery systems. However, the protein is sensitive to environmental stresses; albumin conjugates, on the other hand, have improved functional properties. Biopolymers are gaining interest due to their biodegradability and safety, compared to synthetic polymers. In this study, albumin–biopolymer bioconjugates were prepared by nonenzymatic Maillard reaction at 60 °C and 80% relative humidity. This nonenzymatic conjugation takes place between reducing sugars and available amino groups of a protein in certain conditions. The optimal molar ratio and time for the conjugation were studied by several investigation methods, including circular dichroism and fluorescence spectroscopy, sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), and determination of available amino groups with ortho-phthaldialdehyde (OPA) assay. All of the measurements provided evidence for the covalent bonding of albumin and biopolymers, resulting in bioconjugates. Based on the results, a higher molar ratio and longer time are necessary to complete the reaction with the available amino groups. However, the optimal parameters are specific to each given biopolymer. The rheological behavior of the conjugates is characteristic of the initial biopolymer, which can be useful in drug development. Moreover, both the physical characteristics of albumin and the solubility-improving capacity were enhanced. Therefore, the potential use of albumin–biopolymer bioconjugates in the pharmaceutical industry could be considered.
Rickets in Children: An Update
Authors: Gentile Cristina , Chiarelli Francesco
Published: June 2021

Rickets refers to a deficient mineralization of the growth plate cartilage, predominantly affecting longer bones. Despite the fact that preventive measures are available, it is still a common disease worldwide; nutritional rickets, due to vitamin D deficiency or dietary calcium inadequate intake, remains the most common form. Medical history, physical examination, radiologic features and biochemical tests are essential for diagnosis. Although recent studies suggest hypophosphatemia as the leading alteration, rickets is classically divided into two categories: calcipenic rickets and phosphopenic rickets. Knowledge of this categorization and of respective clinical and laboratory features is essential for rapid diagnosis and correct management. The aim of this review is to analyze the epidemiological, pathogenetic, clinical, and therapeutic aspects of the different forms of rickets, describing the novelties on this “long-lived” disease.