bluuebunny/crossref_metadata_2025 huggingface dataset:
Insight into the AcrAB-TolC Complex Assembly Process Learned from Competition Studies
Authors: Rajapaksha Prasangi , Ojo Isoiza , Yang Ling , Pandeya Ankit , Abeywansha Thilini , Wei Yinan
Published: July 2021

The RND family efflux pump AcrAB-TolC in E. coli and its homologs in other Gram-negative bacteria are major players in conferring multidrug resistance to the cells. While the structure of the pump complex has been elucidated with ever-increasing resolution through crystallography and Cryo-EM efforts, the dynamic assembly process remains poorly understood. Here, we tested the effect of overexpressing functionally defective pump components in wild type E. coli cells to probe the pump assembly process. Incorporation of a defective component is expected to reduce the efflux efficiency of the complex, leading to the so called “dominant negative” effect. Being one of the most intensively studied bacterial multidrug efflux pumps, many AcrA and AcrB mutations have been reported that disrupt efflux through different mechanisms. We examined five groups of AcrB and AcrA mutants, defective in different aspects of assembly and substrate efflux. We found that none of them demonstrated the expected dominant negative effect, even when expressed at concentrations many folds higher than their genomic counterpart. The assembly of the AcrAB-TolC complex appears to have a proof-read mechanism that effectively eliminated the formation of futile pump complex.
Is There a Balance in Oxidative-Antioxidant Status in Blood Serum of Patients with Advanced Endometriosis?
Authors: Kokot Izabela , Piwowar Agnieszka , Jędryka Marcin , Kratz Ewa Maria
Published: July 2021

Can redox homeostasis indicators be potential non-invasive markers, crucial in the diagnosis and treatment of endometriosis? We checked if the differences in levels of serum oxidative-antioxidant balance parameters (TAS, FRAP, albumin, total bilirubin, uric acid, iron, SIRT3, SIRT5, SIRT6, telomerase, AOPP) are significant between patients with advanced endometriosis (E), healthy women (control group, C) and non-endometriosis women, but with other gynecological disorders (NE). The FRAP concentrations were significantly higher in E and NE group than in the control group (p = 0.015 and p = 0.017, respectively). The telomerase concentrations were significantly higher in the endometriosis group than in the control group (p = 0.004). Significantly higher concentrations of AOPP were observed in E (p < 0.001) and NE groups (p = 0.028) in comparison to the control subjects. Between stages III and IV of endometriosis, a significant difference existed only in concentration of iron (p = 0.013). There were no significant differences between the studied groups in the values of the remaining parameters. Based on the results of ROC curve analysis, we can conclude that the levels of serum FRAP, telomerase and AOPP may be taken into account as promising diagnostics markers that reflect the degree of oxidative stress accompanying advanced endometriosis.
Transfer Learning for an Automated Detection System of Fractures in Patients with Maxillofacial Trauma
Authors: Amodeo Maria , Abbate Vincenzo , Arpaia Pasquale , Cuocolo Renato , Dell’Aversana Orabona Giovanni , Murero Monica , Parvis Marco , Prevete Roberto , Ugga Lorenzo
Published: July 2021

An original maxillofacial fracture detection system (MFDS), based on convolutional neural networks and transfer learning, is proposed to detect traumatic fractures in patients. A convolutional neural network pre-trained on non-medical images was re-trained and fine-tuned using computed tomography (CT) scans to produce a model for the classification of future CTs as either “fracture” or “noFracture”. The model was trained on a total of 148 CTs (120 patients labeled with “fracture” and 28 patients labeled with “noFracture”). The validation dataset, used for statistical analysis, was characterized by 30 patients (5 with “noFracture” and 25 with “fracture”). An additional 30 CT scans, comprising 25 “fracture” and 5 “noFracture” images, were used as the test dataset for final testing. Tests were carried out both by considering the single slices and by grouping the slices for patients. A patient was categorized as fractured if two consecutive slices were classified with a fracture probability higher than 0.99. The patients’ results show that the model accuracy in classifying the maxillofacial fractures is 80%. Even if the MFDS model cannot replace the radiologist’s work, it can provide valuable assistive support, reducing the risk of human error, preventing patient harm by minimizing diagnostic delays, and reducing the incongruous burden of hospitalization.
Engineering Properties of Colorful Mortar with Inorganic Color Paste
Authors: Huang Jhih-Ming , Yang Wein-Duo , Wang Her-Yung , Kao Tien-Chun
Published: July 2021

Color cement directly exposes the surface of a concrete building through concrete materials or adding color additives and other technologies to achieve a special aesthetic effect of the overall building’s appearance. The multifunctionality of materials is paid increasing attention with time. This study uses additional 5%, 10% and 15% inorganic color paste and 20% polyacrylic emulsion to colorize mortar, and discusses the fresh properties (slump, slump flow), hardened properties (compressive strength, flexural strength, tensile strength and ultrasonic pulse velocity and durability (surface resistivity, thermal conductivity and length change) of mortar. The results show that the slump and slump flow increase with the content of inorganic color paste; the slump flow is larger than the control group and larger than 25 cm, meaning the inorganic color paste can effectively enhance the workability of mortar. The compressive strength, flexural strength and tensile strength decrease as the inorganic color paste increases. The addition of 5% inorganic color paste still maintains certain engineering properties. The addition of polyacrylic emulsion can improve the tensile strength of mortar, which is higher than the control group. The ultrasonic pulse velocity is a little different from compressive strength, but they have similar trends, and it is higher than 3500 m/s. The durability decreases as the inorganic color paste and polyacrylic emulsion increase, meaning the content of inorganic color paste has relatively significant influence. The surface resistivity at the age of 7 days was higher than 20 kΩ-cm. The findings show that different contents of inorganic color paste and 20% polyacrylic emulsion have different degrees of influence on the engineering properties of colorful mortar.
Effects of O2 Addition on the Discharge Parameters and Production of Reactive Species of a Transferred Atmospheric Pressure Plasma Jet
Authors: Nascimento Fellype , Petroski Kleber , Kostov Konstantin
Published: July 2021

The therapeutic effects of atmospheric pressure plasma jets (APPJs) have been associated with the presence of reactive species, mainly the reactive oxygen and nitrogen ones, generated in this kind of plasmas. Due to that, many studies attempting to enhance the production of reactive species in APPJs have been performed. The employment of gas admixtures, usually mixing a noble gas with oxygen (O2) or water vapor, is one of the most common methods to achieve such goal. This work presents a study of how the addition of small amounts of O2 affects the electrical parameters and the production of reactive species in a transferred APPJ produced at the tip of a long and flexible plastic tube. The study was carried out employing helium (He) as the working gas and applying a high voltage (HV) in the form of amplitude-modulated sine waveform (burst mode). With this configuration it was possible to verify that the O2 addition reduces the discharge power and effective current, as a result of late ignition and shorter discharge duration. It was also found that the addition of O2 to a certain content in the gas admixture makes the light emission from oxygen atoms increase, indicating an increment in oxygen related reactive species in the plasma jet. However, at the same time the light emitted from hydroxyl (OH) and nitric oxide (NO) exhibits the opposite behavior, i.e., decrease, indicating a reduction of such species in the APPJ. For these reasons, the addition of O2 to the working gas seems to be useful for increasing the effectiveness of the plasma treatment only when the target modification effect is directly dependent on the content of atomic oxygen.
The Modification of pBFT Algorithm to Increase Network Operations Efficiency in Private Blockchains
Authors: Min Youn-A
Published: July 2021

The use of blockchain technology is becoming more widespread. Governments have expanded their use of the technology from online polls to business management of smaller local governments while private institutions have increased their services from financial to medical services management. This paper presents the modified pBFT blockchain consensus algorithm for a more efficient data management method in cases of applying blockchains in authorized nodes such as governmental agencies. The network communication cost was minimized while the consensus accuracy was maximized by applying a method of simplifying the request management process and electing the reliability-based consensus node during the pBFT consensus algorithm process. By applying the modified pBFT consensus algorithm, stability and speed of the consensus and verification process among various organizations can be guaranteed as well as application in efficient management and value creation of data.
Optimization of Electric Field Assisted Mining Process Applied to Rare Earths in Soils
Authors: Pires Carolina M. G. , Pereira Jucélio T. , Ribeiro Alexandra B. , Ponte Haroldo A. , Ponte Maria José J. S.
Published: July 2021

The extraction of rare earths has been studied worldwide, however some of these processes have a high cost and can cause negative environmental impacts. In order to mine these species from the soil, Electric Field Assisted Mining arises as an alternative to conventional mining processes. Therefore, the experimental parameters can be improved to obtain better results in the extraction of these species. The aim of this paper is to propose the optimization of the Electric Field Assisted Mining process of yttrium, to obtain the optimal experimental configuration to be applied in real soils. An optimization problem was defined to obtain the maximum extraction mass of yttrium ion (Y3+), considering the limitation for the quantity of electric current density. A hybrid optimization technique was used, based on the sequential application of genetic algorithms and non-linear programming. Different optimal process configurations were obtained, considering distinct limits for the electric current density. The best experimental configuration resulted in 0.5386 V cm−1 electric field strength and 0.10 mol L−1 electrolyte concentration. This condition was reproduced in real soil, which obtained a Y3+ electromining efficiency of 41.48%. The results showed that this technique is promising for the extraction of rare earth in real soils.
An In Vitro Study of Different Types of Greek Honey as Potential Natural Antimicrobials against Dental Caries and Other Oral Pathogenic Microorganisms. Case Study Simulation of Oral Cavity Conditions
Authors: Voidarou Chrysoula (Chrysa) , Antoniadou Maria , Rozos Georgios , Alexopoulos Athanasios , Giorgi Elpida , Tzora Athina , Skoufos Ioannis , Varzakas Theodoros , Bezirtzoglou Eugenia
Published: July 2021

To study the antibacterial effect of different Greek honeys, samples of citrus honey, Saturja spp. Honey, and oregano and sage honey were collected directly from producers. Manuka honey and artificial honey were used as controls. The honeys were diluted in various concentrations to determine the minimum inhibitory concentration (MIC) and were also placed in agar wells to determine the inhibitory zones of growth. The bacteria tested were two reference strains and five pathogens isolated from patients with various dental ailments. A series of samples were diluted with artificial saliva instead of distilled water to simulate the conditions in the oral cavity. The results show that in most cases the Greek honeys, and particularly the citrus honey and the oregano and sage honey, outperformed the antibacterial activity of manuka honey against all tested bacteria. This performance was due to the hydrogen peroxide as well as to other components of the honeys, that is, peptides and other substances such as phenolic compounds and flavonoids. Artificial saliva enhanced the antibacterial effect of the honeys in comparison to distilled water.
Analysis of Flow Characteristics and Effects of Turbulence Models for the Butterfly Valve
Authors: Choi Sung-Woong , Seo Hyoung-Seock , Kim Han-Sang
Published: July 2021

In the present study, the flow characteristics of butterfly valves with different sizes DN 80 (nominal diameter: 76.2 mm), DN 262 (nominal diameter: 254 mm), DN 400 (nominal diameter: 406 mm) were numerically investigated under different valve opening percentages. Representative two-equation turbulence models of two-equation k-epsilon model of Launder and Sharma, two-equation k-omega model of Wilcox, and two-equation k-omega SST model of Menter were selected. Flow characteristics of butterfly valves were examined to determine turbulence model effects. It was determined that increasing turbulence effect could cause many discrepancies between turbulence models, especially in areas with large pressure drop and velocity increase. In addition, sensitivity analysis of flow properties was conducted to determine the effect of constants used in each turbulence model. It was observed that the most sensitive flow properties were turbulence dissipation rate (Epsilon) for the k-epsilon turbulence model and turbulence specific dissipation rate (Omega) for the k-omega turbulence model.
Thermal and Kinetic Properties of Brazilian Coffea Arabica Beans
Authors: Brzezińska Rita , Górska Agata , Wirkowska-Wojdyła Magdalena , Ostrowska-Ligęza Ewa , Bryś Joanna
Published: July 2021

The chemical composition of green coffee beans depends on the number of parameters, such as coffee cherry processing methods, used. The quality of roasted coffee is related to the certain substances that developed during the roasting process and that are responsible for the organoleptic properties. The main objective of this study was an investigation of the thermal behaviour and the fatty acids profile of green and roasted Brazilian Santos coffee beans. The glass transition temperature was measured using modulated differential scanning calorimetry (MDSC). The thermal behaviour of coffee samples was evaluated by means of thermogravimetry (TG) and first derivative thermogravimetry (DTG). The oxidative stability and kinetic parameters were characterized with the use of differential scanning calorimetry (DSC). According to the TG and DTG curves, coffee samples showed different behaviour of thermal degradation in the atmosphere of oxygen and nitrogen. Our research shows that the thermal properties and fatty acids profile did not change during the roasting process.
Numerical and Experimental Study of Aerodynamic Performances of a Morphing Micro Air Vehicle
Authors: Bardera Rafael , Rodríguez-Sevillano Ángel A. , Barroso Estela
Published: July 2021

The present work is focused on the investigation of the aerodynamic performances of a novedous bioinspired morphing Micro Air Vehicle (MAV) with an adaptive wing structure geometry. For this purpose, a numerical study of Computational Fluid Dynamics (CFD) implemented by Ansys Fluent 15.0 was performed in order to obtain insight about the aerodynamic effect of wing structure deformation when morphing devices are used, and its influence on the global aerodynamic parameters related with aircraft performances. On the other hand, an experimental study using the Particle Image Velocimetry technique and balance measurements in a Low-Speed Wind Tunnel was conducted to obtain experimental information about performances measured to establish a comparison between both, experimental and numerical results. The Micro Air Vehicle (MAV) presents a Zimmerman wing with an Eppler 61 airfoil. Three different wing configurations according to curvature and thickness variations and for all angles of attack have been studied. A comparative analysis based on aerodynamic features is performed by an assessment of lift coefficient (CL), total aerodynamic drag coefficient (CD) and aerodynamic efficiency as lift/drag ratio (CL/CD) in order to conclude the best wing configuration in terms of aerodynamic performance.
Bioactivity of Medicinal Plants and Extracts
Authors: Les Francisco , Cásedas Guillermo , López Víctor
Published: July 2021

Nature is an inexhaustible source of bioactive compounds and products with interesting medicinal properties and technological applications [...]
Multiomic Approach to Analyze Infant Gut Microbiota: Experimental and Analytical Method Optimization
Authors: Torrell Helena , Cereto-Massagué Adrià , Kazakova Polina , García Lorena , Palacios Héctor , Canela Núria
Published: July 2021

Background: The human intestinal microbiome plays a central role in overall health status, especially in early life stages. 16S rRNA amplicon sequencing is used to profile its taxonomic composition; however, multiomic approaches have been proposed as the most accurate methods for study of the complexity of the gut microbiota. In this study, we propose an optimized method for bacterial diversity analysis that we validated and complemented with metabolomics by analyzing fecal samples. Methods: Forty-eight different analytical combinations regarding (1) 16S rRNA variable region sequencing, (2) a feature selection approach, and (3) taxonomy assignment methods were tested. A total of 18 infant fecal samples grouped depending on the type of feeding were analyzed by the proposed 16S rRNA workflow and by metabolomic analysis. Results: The results showed that the sole use of V4 region sequencing with ASV identification and VSEARCH for taxonomy assignment produced the most accurate results. The application of this workflow showed clear differences between fecal samples according to the type of feeding, which correlated with changes in the fecal metabolic profile. Conclusion: A multiomic approach using real fecal samples from 18 infants with different types of feeding demonstrated the effectiveness of the proposed 16S rRNA-amplicon sequencing workflow.
PCSK9: A Multi-Faceted Protein That Is Involved in Cardiovascular Biology
Authors: Sundararaman Sai Sahana , Döring Yvonne , van der Vorst Emiel P. C.
Published: July 2021

Pro-protein convertase subtilisin/kexin type 9 (PCSK9) is secreted mostly by hepatocytes and to a lesser extent by the intestine, pancreas, kidney, adipose tissue, and vascular cells. PCSK9 has been known to interact with the low-density lipoprotein receptor (LDLR) and chaperones the receptor to its degradation. In this manner, targeting PCSK9 is a novel attractive approach to reduce hyperlipidaemia and the risk for cardiovascular diseases. Recently, it has been recognised that the effects of PCSK9 in relation to cardiovascular complications are not only LDLR related, but that various LDLR-independent pathways and processes are also influenced. In this review, the various LDLR dependent and especially independent effects of PCSK9 on the cardiovascular system are discussed, followed by an overview of related PCSK9-polymorphisms and currently available and future therapeutic approaches to manipulate PCSK9 expression.
Plasma-Activated Water Promotes Wound Healing by Regulating Inflammatory Responses
Authors: Wang Shuai , Xu Dehui , Qi Miao , Li Bing , Peng Sansan , Li Qiaosong , Zhang Hao , Liu Dingxin
Published: July 2021

Infection can hinder the process of wound healing, so it is important to begin antibacterial treatment quickly after a wound forms. Plasma activated water (PAW) can inactivate a variety of common wound infection bacteria. In this study, we compared the effects of PAW prepared with portable surface discharge plasma equipment and medical alcohol on wound healing in a mouse full-thickness skin wound model. The effectiveness of wound healing processes in mice was ranked accordingly: PAW treatment group > medical alcohol treatment group > control group. In order to further understand the mechanism of PAW in promoting wound healing, we tested the expression levels of the pro-inflammatory factors interleukin (IL)-1β and IL-6, the anti-inflammatory factor IL-10, and vascular endothelial growth factor (VEGF). The results showed that PAW promoted the release of pro-inflammatory factors and anti-inflammatory factors from the wounds in mice, which allowed the mice in the treatment group to transition out of the inflammatory period early and enter the next stage of wound healing. The expression level of VEGF in the wounds of mice in the PAW treatment group was higher, which indicates that the microvessels around the wound in the PAW treatment group proliferated faster, and thus the wound healed faster. PAW biosafety experiments showed that PAW did not significantly affect the appearance, morphology, or tissue structure of internal organs, or blood biochemical indicators in mice. In general, PAW prepared via portable devices is expected to become more widely used given its convenience, affordability, and lack of side effects in promoting wound healing.
Green Synthesis, Structural Characterization and Photocatalytic Applications of ZnO Nanoconjugates Using Heliotropium indicum
Authors: Wijesinghe Udari , Thiripuranathar Gobika , Menaa Farid , Iqbal Haroon , Razzaq Anam , Almukhlifi Hanadi
Published: July 2021

In recent years, biosynthesized zinc oxide nanoparticles (ZnO NPs) have been gaining importance due to their unique properties and tremendous applications. This study aimed to fabricate ZnO NPs by using extracts from various parts of the traditional medicinal plant Heliotropium indicum (H. indicum) and evaluate their photocatalytic activity. Further, their potential in photoluminescence and fluorescence resonance energy transfer (FRET) was assessed. The Ultraviolet-Visible spectrum exhibited a hypsochromic shifted absorption band between 350–380 nm. Transmission electron microscopy (TEM) analysis revealed spherical NPs, while X-ray diffraction (XRD) data revealed wurtzite, hexagonal and crystalline nature. The TEM and XRD consistently determined an average particle size range from 19 to 53 nm. The photocatalytic degradation reaches a maximum of 95% for biogenic ZnO NPs by monitoring spectrophotometrically the degradation of methylene blue dye (λmax = 662.8 nm) under solar irradiation. Photoluminescence analysis revealed differentiated spectra with high-intensity emission peaks for biogenic ZnO NPs compared with chemically synthesized ZnO NPs. Eventually, the highest efficiency of FRET (80%) was found in ZnO NPs synthesized from the leaves. This remains the first report highlighting the multifunctional ZnO NPs capabilities mediated by using H. indicum, which could lead to important potential environmental and biomedical applications.
Synthesizing the High Surface Area g-C3N4 for Greatly Enhanced Hydrogen Production
Authors: Wang Chengfei , Han Tongxin , Xin Chang , Miao Hui
Published: July 2021

Adjusting the structure of g-C3N4 to significantly enhance its photocatalytic activity has attracted considerable attention. Herein, a novel, sponge-like g-C3N4 with a porous structure is prepared from the annealing of protonated melamine under N2/H2 atmosphere (PH-CN). Compared to bulk g-C3N4 via calcination of melamine under ambient atmosphere (B-CN), PH-CN displays thinner nanosheets and a higher surface area (150.1 m2/g), which is a benefit for shortening the diffusion distance of photoinduced carriers, providing more active sites, and finally favoring the enhancement of the photocatalytic activity. Moreover, it can be clearly observed from the UV-vis spectrum that PH-CN displays better performance for harvesting light compared to B-CN. Additionally, the PH-CN is prepared with a larger band gap of 2.88 eV with the Fermi level and conduction band potential increased and valence band potential decreased, which could promote the water redox reaction. The application experiment results show that the hydrogen evolution rate on PH-CN was nearly 10 times higher than that of B-CN, which was roughly 4104 μmol h−1 g−1. The method shown in this work provides an effective approach to adjust the structure of g-C3N4 with considerable photocatalytic hydrogen evolution activity.
Surface Acoustic Wave Biosensor with Laser-Deposited Gold Layer Having Controlled Porosity
Authors: Miu Dana , Constantinoiu Izabela , Dinca Valentina , Viespe Cristian
Published: July 2021

Laser-deposited gold immobilization layers having different porosities were incorporated into love wave surface acoustic wave sensors (LW-SAWs). Variation of pulsed laser deposition parameters allows good control of the gold film morphology. Biosensors with various gold film porosities were tested using the biotin–avidin reaction. Control of the Au layer morphology is important since the biotin and avidin layer morphologies closely follow that of the gold. The response of the sensors to biotin/avidin, which is a good indicator of biosensor performance, is improved when the gold layer has increased porosity. Given the sizes of the proteins, the laser-deposited porous gold interfaces have optimal pore dimensions to ensure protein stability.
The Associations between COMT and MAO-B Genetic Variants with Negative Symptoms in Patients with Schizophrenia
Authors: Madzarac Zoran , Tudor Lucija , Sagud Marina , Nedic Erjavec Gordana , Mihaljevic Peles Alma , Pivac Nela
Published: July 2021

Negative symptoms of schizophrenia, including anhedonia, represent a heavy burden on patients and their relatives. These symptoms are associated with cortical hypodopamynergia and impaired striatal dopamine release in response to reward stimuli. Catechol-O-methyltransferase (COMT) and monoamine oxidase type B (MAO-B) degrade dopamine and affect its neurotransmission. The study determined the association between COMT rs4680 and rs4818, MAO-B rs1799836 and rs6651806 polymorphisms, the severity of negative symptoms, and physical and social anhedonia in schizophrenia. Sex-dependent associations were detected in a research sample of 302 patients with schizophrenia. In female patients with schizophrenia, the presence of the G allele or GG genotype of COMT rs4680 and rs4818, as well as GG haplotype rs4818-rs4680, which were all related to higher COMT activity, was associated with an increase in several dimensions of negative symptoms and anhedonia. In male patients with schizophrenia, carriers of the MAO-B rs1799836 A allele, presumably associated with higher MAO-B activity, had a higher severity of alogia, while carriers of the A allele of the MAO-B rs6651806 had a higher severity of negative symptoms. These findings suggest that higher dopamine degradation, associated with COMT and MAO-B genetic variants, is associated with a sex-specific increase in the severity of negative symptoms in schizophrenia patients.
“Ain’t She a Bute?”: The Importance of Proper History Taking in a Case of Inappropriate Use of Horse NSAID in a Human
Authors: Sawalha Khalid , James Ryan , Mazahreh Farah , Goraya Harmeen , Habash Fuad
Published: July 2021

A 41-year-old woman with no significant past medical history presented to the hospital with complaints of nausea, vomiting, and generalized weakness over two weeks. The patient did not seek medical attention as she assumed that her symptoms willwould resolve. Following her initial denial of drug abuse and her abnormal urine drug screening, we discussed the findings with the patient. She later admitted to using both amphetamines and marijuana. This led us to take a detailed social history that revealed an unexpected event.
Synthesis and Structural Characterization of Isostructural 4-(4-Aryl)-2-(5-(4-fluorophenyl)-3-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazoles
Authors: Kariuki Benson M. , Abdel-Wahab Bakr F. , El-Hiti Gamal A.
Published: July 2021

4-(4-Chlorophenyl)-2-(5-(4-fluorophenyl)-3-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazole (4) and 4-(4-fluorophenyl)-2-(5-(4-fluorophenyl)-3-(1-(4-fluorophenyl)-5-methyl-1H-1,2,3-triazol-4-yl)-4,5-dihydro-1H-pyrazol-1-yl)thiazole (5) have been synthesized in high yields. Crystallization of 4 and 5 from dimethylformamide solvent produced samples suitable for structure determination by single crystal diffraction. The materials are isostructural with triclinic, PĪ and symmetry and comprise two independent molecules in the asymmetric unit. The two independent molecules in the asymmetric unit assume similar conformation. The molecule is essentially planar apart from one of the two fluorophenyl groups, which is oriented roughly perpendicular to the plane of the rest of the molecule.
QKD Based on Symmetric Entangled Bernstein-Vazirani
Authors: Ampatzis Michael , Andronikos Theodore
Published: July 2021

This paper introduces a novel entanglement-based QKD protocol, that makes use of a modified symmetric version of the Bernstein-Vazirani algorithm, in order to achieve secure and efficient key distribution. Two variants of the protocol, one fully symmetric and one semi-symmetric, are presented. In both cases, the spatially separated Alice and Bob share multiple EPR pairs, each one qubit of the pair. The fully symmetric version allows both parties to input their tentative secret key from their respective location and acquire in the end a totally new and original key, an idea which was inspired by the Diffie-Hellman key exchange protocol. In the semi-symmetric version, Alice sends her chosen secret key to Bob (or vice versa). The performance of both protocols against an eavesdroppers attack is analyzed. Finally, in order to illustrate the operation of the protocols in practice, two small scale but detailed examples are given.
Some Integral Inequalities Involving Metrics
Authors: Agarwal Ravi P. , Jleli Mohamed , Samet Bessem
Published: July 2021

In this work, we establish some integral inequalities involving metrics. Moreover, some applications to partial metric spaces are given. Our results are extension of previous obtained metric inequalities in the discrete case.
Drawing Skills of Candidates for Architectural Studies vs. Learning Outcomes of Graduates. Comparative Research Based on the Example of The Faculty of Architecture, Poznan University of Technology
Authors: Gawlak Agata , Pruszewicz-Sipińska Ewa , Bonenberg Wojciech
Published: July 2021

Major changes in the organisation of the teaching process at universities in Poland had to be introduced in response to the current pandemic situation and threat of further spread of SARS-CoV-2 virus. This article presents the results of the research conducted at the Faculty of Architecture, Poznan University of Technology in view of the pilot, experimental entrance exam that excludes the evaluation of drawing skills of candidates for architectural studies in the 2020/21 recruitment process. The purpose of the research was to find a correlation between the quality of candidates accepted for the BSc (engineer) programme studies, evaluated on the basis of their drawing skills demonstrated during the entrance exam and the learning outcomes of graduates. For that purpose, the authors hereof have carried out an analysis with the use of the Spearman Rank Correlation formula. The comparative analysis has shown that candidates whose drawing skills were evaluated highly during the entrance exam did not necessarily rank as the top grade scoring graduates of the first degree study programme, and thus, it has further been shown that good drawing skills at the beginning of the study programme do not guarantee top learning results at the end of the studies. In effect, the research should become a starting point for a discussion in Poland on whether there are any justified grounds for entrance exams in drawing or whether a portfolio of works may replace it and be an effective recruitment criterion.
Tuning Magnetic and Transport Properties in Quasi-2D (Mn1−xNix)2P2S6 Single Crystals
Authors: Shemerliuk Yuliia , Zhou Yonghui , Yang Zhaorong , Cao Gang , Wolter Anja U. B. , Büchner Bernd , Aswartham Saicharan
Published: July 2021

We report an optimized chemical vapor transport method to grow single crystals of (Mn1−xNix)2P2S6 where x = 0, 0.3, 0.5, 0.7, and 1. Single crystals up to 4 mm × 3 mm × 200 μm were obtained by this method. As-grown crystals are characterized by means of scanning electron microscopy and powder X-ray diffraction measurements. The structural characterization shows that all crystals crystallize in monoclinic symmetry with the space group C2/m (No. 12). We have further investigated the magnetic properties of this series of single crystals. The magnetic measurements of the all as-grown single crystals show long-range antiferromagnetic order along all principal crystallographic axes. Overall, the Néel temperature TN is non-monotonous; with increasing Ni2+ doping, the temperature of the antiferromagnetic phase transition first decreases from 80 K for pristine Mn2P2S6 (x = 0) up to x = 0.5 and then increases again to 155 K for pure Ni2P2S6 (x = 1). The magnetic anisotropy switches from out-of-plane to in-plane as a function of composition in (Mn1−xNix)2P2S6 series. Transport studies under hydrostatic pressure on the parent compound Mn2P2S6 evidence an insulator-metal transition at an applied critical pressure of ~22 GPa.
Visual-Feedback-Based Frame-by-Frame Synchronization for 3000 fps Projector–Camera Visual Light Communication
Authors: Sharma Atul , Raut Sushil , Shimasaki Kohei , Senoo Taku , Ishii Idaku
Published: July 2021

This paper proposes a novel method for synchronizing a high frame-rate (HFR) camera with an HFR projector, using a visual feedback-based synchronization algorithm for streaming video sequences in real time on a visible-light communication (VLC)-based system. The frame rates of the camera and projector are equal, and their phases are synchronized. A visual feedback-based synchronization algorithm is used to mitigate the complexities and stabilization issues of wire-based triggering for long-distance systems. The HFR projector projects a binary pattern modulated at 3000 fps. The HFR camera system operates at 3000 fps, which can capture and generate a delay signal to be given to the next camera clock cycle so that it matches the phase of the HFR projector. To test the synchronization performance, we used an HFR projector–camera-based VLC system in which the proposed synchronization algorithm provides maximum bandwidth utilization for the high-throughput transmission ability of the system and reduces data redundancy efficiently. The transmitter of the VLC system encodes the input video sequence into gray code, which is projected via high-definition multimedia interface streaming in the form of binary images 590 × 1060. At the receiver, a monochrome HFR camera can simultaneously capture and decode 12-bit 512 × 512 images in real time and reconstruct a color video sequence at 60 fps. The efficiency of the visual feedback-based synchronization algorithm is evaluated by streaming offline and live video sequences, using a VLC system with single and dual projectors, providing a multiple-projector-based system. The results show that the 3000 fps camera was successfully synchronized with a 3000 fps single-projector and a 1500 fps dual-projector system. It was confirmed that the synchronization algorithm can also be applied to VLC systems, autonomous vehicles, and surveillance applications.
Investigation and Improvement of Standard External Lightning Protection System: Industrial Case Study
Authors: Negara I Made Yulistya , Fahmi Daniar , Asfani Dimas Anton , Hernanda IGN Satriyadi , Pratama Rendi Bagus , Ksatria Arief Budi
Published: July 2021

In this study, the lightning protection system and grounding system of one plant of the petrochemical industry were investigated, evaluated, and improved. The methods used in this study were rolling sphere and angle protection methods. The grounding system of the building under study was modeled and simulated using ATP/EMTP (Alternative Transient Program/Electromagnetic Transient Program) software. The results show that the external lightning protection system of the prilling tower studied does not adhere to IEC 62305 and IEC 1024-1-1 standards. Moreover, the grounding configuration of the DCS building was not appropriate for protecting sensitive equipment inside. Lightning causes an enormous potential difference between lightning ground rods in the grounding system. Additionally, disabling the existing surge protective device (SPD) causes an increase in the magnitude of Ground Potential Rise at the DCS building. Improvement of the lightning protection system of the prilling tower and DCS building on Plant 1 of this petrochemical company as well as some other recommendations for improvements are proposed. This paper also shows evidence that external lightning protection, internal lightning protection, and the grounding system need to be connected to make an exemplary lightning protection system.
DC Solid-State Circuit Breakers with Two-Winding Coupled Inductor for DC Microgrid
Authors: Park Jung-min , Byun Hyung-jun , Kim Sung-hun , Kim Si-hwan , Won Chung-yuen
Published: July 2021

Ensuring a protection scheme in a DC distribution system is more difficult to achieve against pole-to-ground faults than in AC distribution system because of the absence of zero crossing points and low line impedance. To complement the major obstacle of limiting the fault current, several compositions have been proposed related to mechanical switching and solid-state switching. Among them, solid-state circuit breakers (SSCBs) are considered to be a possible solution to limit fast fault current. However, they may cause problems in circuit complexity, reliability, and cost-related troubles because of the use of multiple power semiconductor devices and additional circuit configuration to commutate the current. This paper proposes a SSCB with a coupled inductor (SSCB-CI) that has a symmetrical configuration. The circuit is comprised of passive components like commutation capacitors, a CI, and damping resistors. Thus, the proposed SSCB-CI offers the advantages of a simple circuit configuration and fewer utilized power semiconductor devices than the other typical SSCBs in the DC microgrid. For the analysis, six operation states are described for the voltage across the main switches and fault current. The effectiveness of the SSCB-CI against the short-circuit fault is proved via simulation and experimental results in a lab-scale prototype.
Evaluation of New PCM/PV Configurations for Electrical Energy Efficiency Improvement through Thermal Management of PV Systems
Authors: Ahmad Abdalqader , Navarro Helena , Ghosh Saikat , Ding Yulong , Roy Jatindra Nath
Published: July 2021

Photovoltaic modules during sunny days can reach temperatures 35 °C above the ambient temperature, which strongly influences their performance and electrical efficiency as power losses can be up to −0.65%/°C. To minimize and control the PV panel temperature, the scientific community has proposed different strategies and innovative approaches, one of them through passive cooling with phase change materials (PCM). However, further investigation, including the effects of geometric shape, insulation, phase change temperature, ambient temperature, and solar radiation on the PV module power output and efficiency, needs further optimization and research. Therefore, the current work aims to investigate several system configurations and different PCMs (RT42, RT31, and RT25) and compare the system with and without insulation through computational fluid dynamic (CFD) tools. The final goal is to optimise and control the temperature of PV modules and evaluate their system efficiency and energy generation. The results showed that compared with a rectangular shape of the PCM container, the trapezoid-one exhibits a considerably better cooling performance with a negligible variation of the PV temperature, even when the melting temperature of the PCM was lower than the average ambient temperature. Moreover, the study showed that having insulation in the PCM container increases the amount of PCM needed, compared with no insulation case, and the increased amount depends on the PCM type. The newly proposed PV/PCM system configuration shows an efficiency and power generation enhancement of 17% and 14.6%, respectively, at peak times.
Analysis of Factors Relevant to Revenue Enhancement in Hernia Interventions (SwissDRG G09)
Authors: Enodien Bassey , Taha-Mehlitz Stephanie , Bachmann Marta , Staartjes Victor E. , Gripp Maike , Staudner Tobias , Taha Anas , Frey Daniel
Published: July 2021

Background: Since diagnosis-related groups (SwissDRG) were established in Switzerland in 2012, small and medium-size hospitals have encountered increasing financial troubles. Even though hernia repair operations are frequent, most hospitals fail to cover their costs with these procedures. Previous studies have focused mainly on analyzing costs and the contributing factors but less on variables that can be positively influenced. Therefore, this study aims to identify the relevant and influenceable factors for revenue growth in hernia repair surgery. Methods: Data from all patients who underwent the SwissDRG G09 surgery for a hernia in 2019 were analyzed. The contribution margin (CM4), as well as any over- or under-coverage, was correlated to case-specific costs. Results: A total of 168 patients received hernia repair surgery with the SwissDRG code G09. The average revenue/loss generated by one procedure was CHF −623.84. Procedures covered by the General Health Insurance (OKP) generated a loss of CHF −830.70 on average, whereas procedures covered by private insurance companies (VVG) generated revenue of CHF +1100 on average. Significant factors impacting the profitability of hernia repair operations were teaching during surgery (p < 0.005), the surgical operating time (p < 0.001), the total anesthesia time (p < 0.001), the number of surgeons present (p = 0.022), the insurance state of patients (p < 0.001), and the type of surgery (p < 0.01 for Lichtenstein’s procedure). Conclusions: This study reveals that hernia repair surgery performed under cost coverage by OKP is generally unprofitable. Our results further imply that the most important and influenceable factors for revenue enhancement are the quality and process optimization of the surgical department. To compensate for this deficit, hospitals should aim to increase the percentage of patients with private health insurance coverage in their procedures. Since outpatient surgery does not provide a valid alternative due to the low reimbursement by insurance companies, the cost efficiency of inpatient hernia repair needs to be increased by process optimization of the surgical department; for instance, by providing specialized hernia teams performing with shorter operation times and high quality.
User-Centred Design of Multidisciplinary Spatial Data Platforms for Human-History Research
Authors: Roose Meeli , Nylén Tua , Tolvanen Harri , Vesakoski Outi
Published: July 2021

The role of open spatial data is growing in human-history research. Spatiality can be utilized to bring together and seamlessly examine data describing multiple aspects of human beings and their environment. Web-based spatial data platforms can create equal opportunities to view and access these data. In this paper, we aim at advancing the development of user-friendly spatial data platforms for multidisciplinary research. We conceptualize the building process of such a platform by systematically reviewing a diverse sample of historical spatial data platforms and by piloting a user-centered design process of a multidisciplinary spatial data platform. We outline (1) the expertise needed in organizing multidisciplinary spatial data sharing, (2) data types that platforms should be able to handle, (3) the most useful platform functionalities, and (4) the design process itself. We recommend that the initiative and subject expertise should come from the end-users, i.e., scholars of human history, and all key end-user types should be involved in the design process. We also highlight the importance of geographic expertise in the process, an important link between subject, spatial and technical viewpoints, for reaching a common understanding and common terminology. Based on the analyses, we identify key development goals for spatial data platforms, including full layer management functionalities. Moreover, we identify the main roles in the user-centered design process, main user types and suggest good practices including a multimodal design workshop.
Performance of the Polydopamine-Graphene Oxide Composite Substrate in the Osteogenic Differentiation of Mouse Embryonic Stem Cells
Authors: Shim Na Young , Heo Jung Sun
Published: July 2021

Graphene oxide (GO) is a biocompatible material considered a favorable stem cell culture substrate. In this study, GO was modified with polydopamine (PDA) to facilitate depositing GO onto a tissue culture polystyrene (PT) surface, and the osteogenic performance of the PDA/GO composite in pluripotent embryonic stem cells (ESCs) was investigated. The surface chemistry of the PDA/GO-coated PT surface was analyzed by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). A high cell viability of ESCs cultured on the PDA/GO composite-coated surface was initially ensured. Then, the osteogenic differentiation of the ESCs in response to the PDA/GO substrate was assessed by alkaline phosphatase (ALP) activity, intracellular calcium levels, matrix mineralization assay, and evaluation of the mRNA and protein levels of osteogenic factors. The culture of ESCs on the PDA/GO substrate presented higher osteogenic potency than that on the uncoated control surface. ESCs cultured on the PDA/GO substrate expressed significantly higher levels of integrin α5 and β1, as well as bone morphogenetic protein receptor (BMPR) types I and II, compared with the control groups. The phosphorylation of extracellular signal-regulated kinase (ERK)1/2, p38, and c-Jun-N-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs) was observed in ESCs culture on the PDA/GO substrate. Moreover, BMP signal transduction by SMAD1/5/8 phosphorylation was increased more in cells on PDA/GO than in the control. The nuclear translocation of SMAD1/5/8 in cells was also processed in response to the PDA/GO substrate. Blocking activation of the integrin α5/β1, MAPK, or SMAD signaling pathways downregulated the PDA/GO-induced osteogenic differentiation of ESCs. These results suggest that the PDA/GO composite stimulates the osteogenic differentiation of ESCs via the integrin α5/β1, MAPK, and BMPR/SMAD signaling pathways.
Protein–Protein Docking with Large-Scale Backbone Flexibility Using Coarse-Grained Monte-Carlo Simulations
Authors: Kurcinski Mateusz , Kmiecik Sebastian , Zalewski Mateusz , Kolinski Andrzej
Published: July 2021

Most of the protein–protein docking methods treat proteins as almost rigid objects. Only the side-chains flexibility is usually taken into account. The few approaches enabling docking with a flexible backbone typically work in two steps, in which the search for protein–protein orientations and structure flexibility are simulated separately. In this work, we propose a new straightforward approach for docking sampling. It consists of a single simulation step during which a protein undergoes large-scale backbone rearrangements, rotations, and translations. Simultaneously, the other protein exhibits small backbone fluctuations. Such extensive sampling was possible using the CABS coarse-grained protein model and Replica Exchange Monte Carlo dynamics at a reasonable computational cost. In our proof-of-concept simulations of 62 protein–protein complexes, we obtained acceptable quality models for a significant number of cases.