bluuebunny/crossref_metadata_2025 huggingface dataset:
Pathophysiology and Treatment of Stroke: Present Status and Future Perspectives
Authors: Kuriakose Diji , Xiao Zhicheng
Published: October 2020

Stroke is the second leading cause of death and a major contributor to disability worldwide. The prevalence of stroke is highest in developing countries, with ischemic stroke being the most common type. Considerable progress has been made in our understanding of the pathophysiology of stroke and the underlying mechanisms leading to ischemic insult. Stroke therapy primarily focuses on restoring blood flow to the brain and treating stroke-induced neurological damage. Lack of success in recent clinical trials has led to significant refinement of animal models, focus-driven study design and use of new technologies in stroke research. Simultaneously, despite progress in stroke management, post-stroke care exerts a substantial impact on families, the healthcare system and the economy. Improvements in pre-clinical and clinical care are likely to underpin successful stroke treatment, recovery, rehabilitation and prevention. In this review, we focus on the pathophysiology of stroke, major advances in the identification of therapeutic targets and recent trends in stroke research.
Insulated Switches: Dual-Function Protein RalGEFRGL-1 Promotes Developmental Fidelity
Authors: Duong Tam , Rasmussen Neal R. , Reiner David J.
Published: October 2020

The C. elegans vulva is an excellent model for the study of developmental biology and cell–cell signaling. The developmental induction of vulval precursor cells (VPCs) to assume the 3°-3°-2°-1°-2°-3° patterning of cell fates occurs with 99.8% accuracy. During C. elegans vulval development, an EGF signal from the anchor cell initiates the activation of RasLET-60 > RafLIN-45 > MEKMEK-2 > ERKMPK-1 signaling cascade to induce the 1° cell. The presumptive 1° cell signals its two neighboring cells via NotchLIN-12 to develop 2° cells. In addition, RasLET-60 switches effectors to RalGEFRGL-1 > RalRAL-1 to promote 2° fate. Shin et al. (2019) showed that RalGEFRGL-1 is a dual-function protein in VPCs fate patterning. RalGEFRGL-1 functions as a scaffold for PDKPDK-1 > AktAKT-1/2 modulatory signaling to promote 1° fate in addition to propagating the RasLET-60 modulatory signal through RalRAL-1 to promote 2° fate. The deletion of RalGEFRGL-1 increases the frequency of VPC patterning errors 15-fold compared to the wild-type control. We speculate that RalGEFRGL-1 represents an “insulated switch”, whereby the promotion of one signaling activity curtails the promotion of the opposing activity. This property might increase the impact of the switch on fidelity more than two separately encoded proteins could. Understanding how developmental fidelity is controlled will help us to better understand the origins of cancer and birth defects, which occur in part due to the misspecification of cell fates.
Circulating MiRNA-195-5p and -451a in Diabetic Patients with Transient and Acute Ischemic Stroke in the Emergency Department
Authors: Giordano Mauro , Trotta Maria Consiglia , Ciarambino Tiziana , D’Amico Michele , Galdiero Marilena , Schettini Federico , Paternosto Diego , Salzillo Marta , Alfano Roberto , Andreone Vincenzo , Malatino Lorenzo Salvatore , Biolo Gianni , Paolisso Giuseppe , Adinolfi Luigi Elio
Published: October 2020

(1) Background: Circulating micro-RNAs (miRNAs) modulate the expression of molecules in diabetes. We evaluated the expression of serum miRNA-195-5p and -451a in diabetic patients with ischemic stroke and correlated them with two markers of brain tissue integrity. (2) Methods: Seventy-eight subjects with acute ischemic stroke (AIS) or transient ischemic attack (TIA) (40 with diabetes) were enrolled. Serum miRNA levels, brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor A (VEGF-A) were assessed at admission and 24 and 72 h after a post-ischemic stroke, and were compared to 20 controls. (3) Results: Both circulating miRNAs were two-fold up-regulated in diabetic AIS and TIA patients compared to non-diabetics. Their levels progressively decreased at 24 and 72 h in both AIS and TIA patients. Interestingly, in the non-diabetic TIA group, both circulating miRNAs, although higher than the controls, tended to achieve a complete decay after 72 h. Furthermore, miRNA-195-5p and miRNA-451a levels inversely correlated with both BDNF and VEGF-A serum levels. (4) Conclusions: These data show a different profile of both micro-RNAs in diabetic versus non-diabetic patients after acute ischemic stroke, suggesting their pivotal role in cerebrovascular ischemic attack.
Deferred Administration of Afobazole Induces Sigma1R-Dependent Restoration of Striatal Dopamine Content in a Mouse Model of Parkinson’s Disease
Authors: Kadnikov Ilya A. , Verbovaya Ekaterina R. , Voronkov Dmitry N. , Voronin Mikhail V. , Seredenin Sergei B.
Published: October 2020

Previously, we demonstrated that the immediate administration of multitarget anxiolytic afobazole slows down the progression of neuronal damage in a 6-hydroxidodamine (6-OHDA) model of Parkinson’s disease due to the activation of chaperone Sigma1R. The aim of the present study is to evaluate the therapeutic potential of deferred afobazole administration in this model. Male ICR mice received a unilateral 6-OHDA lesion of the striatum. Fourteen days after the surgery, mice were treated with afobazole, selective Sigma1R agonist PRE-084, selective Sigma1R antagonist BD-1047, and a combination of BD-1047 with afobazole or PRE-084 for another 14 days. The deferred administration of afobazole restored the intrastriatal dopamine content in the 6-OHDA-lesioned striatum and facilitated motor behavior in rotarod tests. The action of afobazole accorded with the effect of Sigma1R selective agonist PRE-084 and was blocked by Sigma1R selective antagonist BD-1047. The present study illustrates the Sigma1R-dependent effects of afobazole in a 6-OHDA model of Parkinson’s disease and reveals the therapeutic potential of Sigma1R agonists in treatment of the condition.
Exploration of Feasible Immune Biomarkers for Immune Checkpoint Inhibitors in Head and Neck Squamous Cell Carcinoma Treatment in Real World Clinical Practice
Authors: Wang Hui-Ching , Yeh Tsung-Jang , Chan Leong-Perng , Hsu Chin-Mu , Cho Shih-Feng
Published: October 2020

Recurrent locally advanced or metastatic head and neck squamous cell carcinoma (HNSCC) is associated with dismal prognosis because of its highly invasive behavior and resistance to conventional intensive chemotherapy. The combination of targeted therapy and conventional chemotherapy has significantly improved clinical outcomes. In recent years, the development of immunotherapies, such as immune checkpoint inhibitors (ICIs), has further increased treatment responses and prolonged survival. However, the limited response rate, risk of immunotherapy-related adverse effects and high cost of immunotherapy make the identification of predictive markers to optimize treatment efficacy a critical issue. Biomarkers are biological molecules that have been widely utilized to predict treatment response to certain treatments and clinical outcomes or to detect disease. An ideal biomarker should exhibit good predictive ability, which can guide healthcare professionals to achieve optimal treatment goals and bring clinical benefit to patients. In this review, we summarized the results of recent and important studies focused on HNSCC ICI immunotherapy and discussed potential biomarkers including their strengths and limitations, aiming to gain more insight into HNSCC immunotherapy in real world clinical practice.
Molecular Mechanisms and Emerging Therapeutics for Osteoporosis
Authors: Noh Ji-Yoon , Yang Young , Jung Haiyoung
Published: October 2020

Osteoporosis is the most common chronic metabolic bone disease. It has been estimated that more than 10 million people in the United States and 200 million men and women worldwide have osteoporosis. Given that the aging population is rapidly increasing in many countries, osteoporosis could become a global challenge with an impact on the quality of life of the affected individuals. Osteoporosis can be defined as a condition characterized by low bone density and increased risk of fractures due to the deterioration of the bone architecture. Thus, the major goal of treatment is to reduce the risk for fractures. There are several treatment options, mostly medications that can control disease progression in risk groups, such as postmenopausal women and elderly men. Recent studies on the basic molecular mechanisms and clinical implications of osteoporosis have identified novel therapeutic targets. Emerging therapies targeting novel disease mechanisms could provide powerful approaches for osteoporosis management in the future. Here, we review the etiology of osteoporosis and the molecular mechanism of bone remodeling, present current pharmacological options, and discuss emerging therapies targeting novel mechanisms, investigational treatments, and new promising therapeutic approaches.
Role of Cadherins in Cancer—A Review
Authors: Kaszak Ilona , Witkowska-Piłaszewicz Olga , Niewiadomska Zuzanna , Dworecka-Kaszak Bożena , Ngosa Toka Felix , Jurka Piotr
Published: October 2020

Cadherins play an important role in tissue homeostasis, as they are responsible for cell-cell adhesion during embryogenesis, tissue morphogenesis, differentiation and carcinogenesis. Cadherins are inseparably connected with catenins, forming cadherin-catenin complexes, which are crucial for cell-to-cell adherence. Any dysfunction or destabilization of cadherin-catenin complex may result in tumor progression. Epithelial mesenchymal transition (EMT) is a mechanism in which epithelial cadherin (E-cadherin) expression is lost during tumor progression. However, during tumorigenesis, many processes take place, and downregulation of E-cadherin, nuclear β-catenin and p120 catenin (p120) signaling are among the most critical. Additional signaling pathways, such as Receptor tyrosine kinase (RTK), Rho GTPases, phosphoinositide 3-kinase (PI3K) and Hippo affect cadherin cell-cell adhesion and also contribute to tumor progression and metastasis. Many signaling pathways may be activated during tumorigenesis; thus, cadherin-targeting drugs seem to limit the progression of malignant tumor. This review discusses the role of cadherins in selected signaling mechanisms involved in tumor growth. The clinical importance of cadherin will be discussed in cases of human and animal cancers.
The Role of Resolvins: EPA and DHA Derivatives Can Be Useful in the Prevention and Treatment of Ischemic Stroke
Authors: Tułowiecka Nikola , Kotlęga Dariusz , Prowans Piotr , Szczuko Małgorzata
Published: October 2020

Introduction: Most ischemic strokes develop as a result of atherosclerosis, in which inflammation plays a key role. The synthesis cascade of proinflammatory mediators participates in the process induced in the vascular endothelium and platelets. Resolvins are anti-inflammatory mediators originating from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which may improve the prognosis related to atherosclerosis by inhibiting the production of proinflammatory cytokines, limiting neutrophil migration, or positively influencing phagocytosis. Although clinical trials with resolvin in humans after stroke have not been realized, they may soon find application. Aim: The aim of the study was to review the available literature on the scope of the possibilities of the prevention and treatment of stroke with the use of resolvins, EPA and DHA derivatives. Materials and methods: The review features articles published until 31 January 2020. The search for adequate literature was conducted using the keywords: stroke and resolvins. Over 150 articles were found. Studies not written in English, letters to the editor, conference abstracts, and duplicate information were excluded. Results: In several studies using the animal model, the supplementation of resolvin D2 decreased brain damage caused by myocardial infarction, and it reversed the neurological dysfunction of the brain. A decrease in the concentration of proinflammatory cytokines, such as TNF-α, Il-6, and Il-1β, was also observed, as well as a decrease in the scope of brain damage. In the context of stroke in animals, the treatment with resolvin D2 (RvD2) (injection) has a better effect than supplementation with DHA. Conclusions: Resolvins are characterised by strong anti-inflammatory properties. Resolvins improve prognosis and decrease the risk of developing cardiovascular disease, consequently lowering the risk of stroke, and may find application in the treatment of stroke.
A Novel CCT5 Missense Variant Associated with Early Onset Motor Neuropathy
Authors: Antona Vincenzo , Scalia Federica , Giorgio Elisa , Radio Francesca C. , Brusco Alfredo , Oliveri Massimiliano , Corsello Giovanni , Lo Celso Fabrizio , Vadalà Maria , Conway de Macario Everly , Macario Alberto J. L. , Cappello Francesco , Giuffrè Mario
Published: October 2020

Diseases associated with acquired or genetic defects in members of the chaperoning system (CS) are increasingly found and have been collectively termed chaperonopathies. Illustrative instances of genetic chaperonopathies involve the genes for chaperonins of Groups I (e.g., Heat shock protein 60, Hsp60) and II (e.g., Chaperonin Containing T-Complex polypeptide 1, CCT). Examples of the former are hypomyelinating leukodystrophy 4 (HLD4 or MitCHAP60) and hereditary spastic paraplegia (SPG13). A distal sensory mutilating neuropathy has been linked to a mutation [p.(His147Arg)] in subunit 5 of the CCT5 gene. Here, we describe a new possibly pathogenic variant [p.(Leu224Val)] of the same subunit but with a different phenotype. This yet undescribed disease affects a girl with early onset demyelinating neuropathy and a severe motor disability. By whole exome sequencing (WES), we identified a homozygous CCT5 c.670C>G p.(Leu224Val) variant in the CCT5 gene. In silico 3D-structure analysis and bioinformatics indicated that this variant could undergo abnormal conformation and could be pathogenic. We compared the patient’s clinical, neurophysiological and laboratory data with those from patients carrying p.(His147Arg) in the equatorial domain. Our patient presented signs and symptoms absent in the p.(His147Arg) cases. Molecular dynamics simulation and modelling showed that the Leu224Val mutation that occurs in the CCT5 intermediate domain near the apical domain induces a conformational change in the latter. Noteworthy is the striking difference between the phenotypes putatively linked to mutations in the same CCT subunit but located in different structural domains, offering a unique opportunity for elucidating their distinctive roles in health and disease
Dissecting Total Plasma and Protein-Specific Glycosylation Profiles in Congenital Disorders of Glycosylation
Authors: Hipgrave Ederveen Agnes L. , de Haan Noortje , Baerenfaenger Melissa , Lefeber Dirk J. , Wuhrer Manfred
Published: October 2020

Protein N-glycosylation is a multifactorial process involved in many biological processes. A broad range of congenital disorders of glycosylation (CDGs) have been described that feature defects in protein N-glycan biosynthesis. Here, we present insights into the disrupted N-glycosylation of various CDG patients exhibiting defects in the transport of nucleotide sugars, Golgi glycosylation or Golgi trafficking. We studied enzymatically released N-glycans of total plasma proteins and affinity purified immunoglobulin G (IgG) from patients and healthy controls using mass spectrometry (MS). The applied method allowed the differentiation of sialic acid linkage isomers via their derivatization. Furthermore, protein-specific glycan profiles were quantified for transferrin and IgG Fc using electrospray ionization MS of intact proteins and glycopeptides, respectively. Next to the previously described glycomic effects, we report unprecedented sialic linkage-specific effects. Defects in proteins involved in Golgi trafficking (COG5-CDG) and CMP-sialic acid transport (SLC35A1-CDG) resulted in lower levels of sialylated structures on plasma proteins as compared to healthy controls. Findings for these specific CDGs include a more pronounced effect for α2,3-sialylation than for α2,6-sialylation. The diverse abnormalities in glycomic features described in this study reflect the broad range of biological mechanisms that influence protein glycosylation.
Extracellular Nucleotides Regulate Arterial Calcification by Activating Both Independent and Dependent Purinergic Receptor Signaling Pathways
Authors: Opdebeeck Britt , Orriss Isabel R. , Neven Ellen , D’Haese Patrick C. , Verhulst Anja
Published: October 2020

Arterial calcification, the deposition of calcium-phosphate crystals in the extracellular matrix, resembles physiological bone mineralization. It is well-known that extracellular nucleotides regulate bone homeostasis raising an emerging interest in the role of these molecules on arterial calcification. The purinergic independent pathway involves the enzymes ecto-nucleotide pyrophosphatase/phosphodiesterases (NPPs), ecto-nucleoside triphosphate diphosphohydrolases (NTPDases), 5′-nucleotidase and alkaline phosphatase. These regulate the production and breakdown of the calcification inhibitor—pyrophosphate and the calcification stimulator—inorganic phosphate, from extracellular nucleotides. Maintaining ecto-nucleotidase activities in a well-defined range is indispensable as enzymatic hyper- and hypo-expression has been linked to arterial calcification. The purinergic signaling dependent pathway focusses on the activation of purinergic receptors (P1, P2X and P2Y) by extracellular nucleotides. These receptors influence arterial calcification by interfering with the key molecular mechanisms underlying this pathology, including the osteogenic switch and apoptosis of vascular cells and possibly, by favoring the phenotypic switch of vascular cells towards an adipogenic phenotype, a recent, novel hypothesis explaining the systemic prevention of arterial calcification. Selective compounds influencing the activity of ecto-nucleotidases and purinergic receptors, have recently been developed to treat arterial calcification. However, adverse side-effects on bone mineralization are possible as these compounds reasonably could interfere with physiological bone mineralization.
Phosphoproteomics Meets Chemical Genetics: Approaches for Global Mapping and Deciphering the Phosphoproteome
Authors: Jurcik Jan , Sivakova Barbara , Cipakova Ingrid , Selicky Tomas , Stupenova Erika , Jurcik Matus , Osadska Michaela , Barath Peter , Cipak Lubos
Published: October 2020

Protein kinases are important enzymes involved in the regulation of various cellular processes. To function properly, each protein kinase phosphorylates only a limited number of proteins among the thousands present in the cell. This provides a rapid and dynamic regulatory mechanism that controls biological functions of the proteins. Despite the importance of protein kinases, most of their substrates remain unknown. Recently, the advances in the fields of protein engineering, chemical genetics, and mass spectrometry have boosted studies on identification of bona fide substrates of protein kinases. Among the various methods in protein kinase specific substrate identification, genetically engineered protein kinases and quantitative phosphoproteomics have become promising tools. Herein, we review the current advances in the field of chemical genetics in analog-sensitive protein kinase mutants and highlight selected strategies for identifying protein kinase substrates and studying the dynamic nature of protein phosphorylation.
TechTeach—An Innovative Method to Increase the Students Engagement at Classrooms
Authors: Portela Filipe
Published: October 2020

Higher education is changing, and a new normal is coming. Students are even more demanding, and professors need to follow the evolution of technology and try to increase student engagement in the classrooms (presential or virtual). Higher education students recognise that the introduction of new tools and learning methods can improve the teaching quality and increase the motivation to learn. Regarding a question about which type of classes students preferred, ninety-one point ninety-nine per cent (91.99%) of the students wanted interactive classes over traditional. Having this concern in mind over the past years, a professor explored a set of methods, strategies and tools and designed a new and innovative paradigm using gamification. This approach is denominated TechTeach and explores a set of trending concepts and interactive tools to teach computer science subjects. It was designed to run in a B-learning environment. The paradigm uses flipped classrooms, bring your own device (BYOD), gamification, training of soft-skills and quizzes and surveys to increase the student’s engagement and provide the best learning environment to students. Currently, COVID-19 is bringing about new challenges, and TechTeach was improved in order to be more suitable for this new way of teaching (from 0% to 100% online classes). This article details this method and shows how it can be applied in a real environment. A case study was used to prove the functionality and relevance of this approach, and the achieved results are motivating. During the semester, more than a hundred students experienced this new way of teaching and assessment. In the end, more than eighty-one per cent (81%) of the students gave a positive grade to the approach, and more than ninety-five per cent (95.65%) of the students approved the use of the concept of BYOD in the classroom. With TechTeach, the classroom is not a boring place anymore; it is a place to learn and enjoy regardless of being physical or not.
A Corpus Approach to Roman Law Based on Justinian’s Digest
Authors: Ribary Marton , McGillivray Barbara
Published: October 2020

Traditional philological methods in Roman legal scholarship such as close reading and strict juristic reasoning have analysed law in extraordinary detail. Such methods, however, have paid less attention to the empirical characteristics of legal texts and occasionally projected an abstract framework onto the sources. The paper presents a series of computer-assisted methods to open new frontiers of inquiry. Using a Python coding environment, we have built a relational database of the Latin text of the Digest, a historical sourcebook of Roman law compiled under the order of Emperor Justinian in 533 CE. Subsequently, we investigated the structure of Roman law by automatically clustering the sections of the Digest according to their linguistic profile. Finally, we explored the characteristics of Roman legal language according to the principles and methods of computational distributional semantics. Our research has discovered an empirical structure of Roman law which arises from the sources themselves and complements the dominant scholarly assumption that Roman law rests on abstract structures. By building and comparing Latin word embeddings models, we were also able to detect a semantic split in words with general and legal sense. These investigations point to a practical focus in Roman law which is consistent with the view that ancient law schools were more interested in training lawyers for practice rather than in philosophical neatness.
Antimicrobial Activity of an Extract of Hermetia illucens Larvae Immunized with Lactobacillus casei against Salmonella Species
Authors: Lee Kyu-Shik , Yun Eun-Young , Goo Tae-Won
Published: October 2020

The expressions of antimicrobial peptides (AMPs) in the larvae of the black soldier fly, Hermetia illucens, were significantly increased by pathogen or stimulant induced innate immunity activation. We immunized H. illucens fifth instar larvae with five different Lactobacillus species, that is, Lactobacillus acidophilus, L. brevis, L. casei, L. fermentum, or L. delbrueckii, to induce the mass production of AMPs and selected optimal immune inducers. Antimicrobial activities in hemolymph and H. illucens larvae (HIL) extract were evaluated against three salmonella species (Salmonella pullorum, Salmonella typhimurium, and Salmonella enteritidis). Highest antimicrobial activity was shown by the hemolymph of HIL immunized by L. casei and its activity was closely linked with the inductions of cecropin 1 (HiCec1) and defensin 1 (HiDef1) gene expressions. Furthermore, antimicrobial activity in hemolymph was stable to heat and pH and the growth of three Salmonella species were dramatically suppressed by HIL hemolymph and extract after immunization with L. casei. The minimal inhibitory concentration (MICs) of L. casei-immunized HIL extract against Staphylococcus aureus, Escherichia coli, and Salmonella species ranged from 100~200 µg/100 µL and no cytotoxicity to CaCo-2 and L929 cells were observed in the concentration range 100~40,000 µg/100 µL. Taken together, the present investigation demonstrates that L. casei-immunized HIL extract is a powerful natural antibiotic and preservative that can prevent contamination by Salmonella species.
A Deep Learning Model for Demand-Driven, Proactive Tasks Management in Pervasive Computing
Authors: Kolomvatsos Kostas , Anagnostopoulos Christos
Published: October 2020

Pervasive computing applications deal with the intelligence surrounding users that can facilitate their activities. This intelligence is provided in the form of software components incorporated in embedded systems or devices in close distance with end users. One example of infrastructure that can host intelligent pervasive services is the Edge Computing (EC) ecosystem. EC nodes can execute a number of tasks for data collected by devices present in the Internet of Things (IoT). In this paper, we propose an intelligent, proactive tasks management model based on demand. Demand depicts the number of users or applications interested in using the available tasks in EC nodes, thus characterizing their popularity. We rely on a Deep Machine Learning (DML) model and more specifically on a Long Short Term Memory (LSTM) network to learn the distribution of demand indicators for each task and estimate the future interest in them. This information is combined with historical observations of and support for a decision making scheme to conclude which tasks that are offloaded due to limited interest in them. We have to recognise that, in our decision making, we also take into consideration the load that every task may add to the processing node where it will be allocated. The description of our model is accompanied by a large set of experimental simulations for evaluating the proposed mechanism. We provide numerical results and reveal that the proposed scheme is capable of deciding on the fly, while concluding the most efficient decisions.
Multi-Visual Feature Saliency Detection for Sea-Surface Targets through Improved Sea-Sky-Line Detection
Authors: Lin Chang , Chen Wu , Zhou Haifeng
Published: October 2020

To visually detect sea-surface targets, the objects of interest must be effectively and rapidly isolated from the background of sea-surface images. In contrast to traditional image detection methods, which employ a single visual feature, this paper proposes a significance detection algorithm based on the fusion of multi-visual features after detecting the sea-sky-lines. The gradient edges of the sea-surface images are enhanced using a Gaussian low-pass filter to eliminate the effect of the image gradients pertaining to the clouds, wave points, and illumination. The potential region and points of the sea-sky-line are identified. The sea-sky-line is fitted through polynomial iterations to obtain a sea-surface image containing the target object. The saliency subgraphs of the high and low frequency, gradient texture, luminance, and color antagonism features are fused to obtain an integrated saliency map of the sea-surface image. The saliency target area of the sea surface is segmented. The effectiveness of the proposed method was verified. The average detection rate and time for the sea-sky-line detection were 96.3% and 1.05 fps, respectively. The proposed method outperformed the existing saliency models on the marine obstacle detection dataset and Singapore maritime dataset, with mean absolute errors of 0.075 and 0.051, respectively.
Application of Reference Voltage Control Method of the Generator Using a Neural Network in Variable Speed Synchronous Generation System of DC Distribution for Ships
Authors: Jeon Hyeonmin , Kim Jongsu
Published: October 2020

In the case of DC power distribution-based variable speed engine synchronous generators, if the output reference voltage is kept constant regardless of the generator engine operating speed, it may cause damage to the internal device and windings of the generator due to over-flux or over-excitation. The purpose of this study is to adjust the generator reference voltage according to the engine speed change in the DC distribution system with the variable speed engine synchronous generator. A method of controlling the generator reference voltage according to the speed was applied by adjusting the value of the variable resistance input to the external terminal of the automatic voltage regulator using a neural network controller. The learning data of the neural network was measured through an experiment, and the input pattern was set as the rotational speed of the generator engine, and the output pattern was set as the input current of the potentiometer. Using the measured input/output pattern of the neural network, the error backpropagation learning algorithm was applied to derive the optimum connection weight to be applied to the controller. For the test, the variable speed operation range of the generator engine was set to 1100–1800 rpm, and the input current value of the potentiometer according to the speed increase or decrease within the operation range and the output of the voltage output from the actual generator were checked. As a result of neural network control, it was possible to confirm the result that the input current value of the potentiometer accurately reached the target value 4–20 mA at the point where the initial speed change occurred. It was confirmed that the reference voltage was also normally output in the target range of 250–440 V.
Does Corporate Governance Compliance Increase Company Value? Evidence from the Best Practice of the Board
Authors: Aluchna Maria , Kuszewski Tomasz
Published: October 2020

Drawing upon agency theory, we address the limitations of best practice code in the context of emerging governance, emphasizing the role of concentrated ownership. While the code provisions were formulated in developed countries, the transfer of one-size-fits-all guidelines may not address the characteristics and challenges of emerging and post-transition economies. Specifically, we emphasize that provisions of corporate governance codes are aimed at solving the principal–agent conflict between shareholders and managers. These guidelines may remain limited in addressing principal–principal conflicts between majority and minority shareholders and have either a lesser effect on valuation or none at all. Using a unique sample of 155 companies listed on the Warsaw Stock Exchange during the period 2006–2015, with hand-collected data from declarations of conformity, we tested the hypotheses on the link between corporate governance compliance (with board) practice and company value. The period of 2006–2015 was chosen deliberately, due to the relative stability of corporate governance code recommendations over this time. The results of our panel model reveal a negative and statistically significant relation between corporate governance compliance and company value. We contribute to the existing literature providing new evidence on compliance practice in the context of concentrated ownership, and the limited effect of code provisions in addressing structural challenges of corporate governance in emerging post-transition economies and hierarchy-based control systems.
Clinical Evaluation of a Custom Gene Panel as a Tool for Precision Male Infertility Diagnosis by Next-Generation Sequencing
Authors: Cannarella Rossella , Precone Vincenza , Guerri Giulia , Busetto Gian Maria , Di Renzo Gian Carlo , Gerli Sandro , Manara Elena , Dautaj Astrit , Bertelli Matteo , Calogero Aldo Eugenio
Published: October 2020

Background: Up to 15% of couples are infertile and male factor infertility accounts for approximately 50% of these cases. Male infertility is a multifactorial pathological condition. The genetic of male infertility is very complex and at least 2000 genes are involved in its etiology. Genetic testing by next-generation sequencing (NGS) technologies can be relevant for its diagnostic value in male infertile patients. Therefore, the aim of this study was to implement the diagnostic offer with the use of an NGS panel for the identification of genetic variants. Methods: We developed an NGS gene panel that we used in 22 male infertile patients. The panel consisted of 110 genes exploring the genetic causes of male infertility; namely spermatogenesis failure due to single-gene mutations, central hypogonadism, androgen insensitivity syndrome, congenital hypopituitarism, and primary ciliary dyskinesia. Results: NGS and a subsequent sequencing of the positive pathogenic or likely pathogenic variants, 5 patients (23%) were found to have a molecular defect. In particular, pathogenic variants were identified in TEX11, CCDC39, CHD7, and NR5A1 genes. Moreover, 14 variants of unknown significance and 7 novel variants were found that require further functional studies and family segregation. Conclusion: This extended NGS-based diagnostic approach may represent a useful tool for the diagnosis of male infertility. The development of a custom-made gene panel by NGS seems capable of reducing the proportion of male idiopathic infertility.
Physical Fundamentals of Biomaterials Surface Electrical Functionalization
Authors: Baltacis Karlis , Bystrov Vladimir , Bystrova Anna , Dekhtyar Yuri , Freivalds Talivaldis , Raines Jan , Rozenberga Krista , Sorokins Hermanis , Zeidaks Martins
Published: October 2020

This article is focusing on electrical functionalization of biomaterial’s surface to enhance its biocompatibility. It is an overview of previously unpublished results from a series of experiments concerning the effects surface electrical functionalization can have on biological systems. Saccharomyces cerevisiae cells were used for biological experiments. The hydroxyapatite (HAp) specimens were used to investigate influence of structural point defects on the surface electrical charge. Threshold photoelectron emission spectroscopy was used to measure the electron work function of HAp and biologic samples. The density functional theory and its different approximations were used for the calculation of HAp structures with defects. It was shown that the electrical charge deposition on the semiconductor or dielectric substrate can be delivered because of production of the point defects in HAp structure. The spatial arrangements of various atoms of the HAp lattice, i.e., PO4 and OH groups, oxygen vacancies, interstitial H atoms, etc., give the instruments to deposit the electrical charge on the substrate. Immobilization of the microorganisms can be achieved on the even surface of the substrate, characterized with a couple of nanometer roughness. This cells attachment can be controlled because of the surface electrical functionalization (deposition of the electrical charge). A protein layer as a shield for the accumulated surface charge was considered, and it was shown that the protein layer having a thickness below 1 µm is not crucial to shield the electrical charge deposited on the substrate surface. Moreover, the influence of surface charge on the attachment of microorganisms, when the surface roughness is excluded, and the influence of controlled surface roughness on the attachment of microorganisms, when surface charge is constant, were also considered.
Concrete Compressive Strength under Changing Environmental Conditions during Placement Processes
Authors: Ambroziak Andrzej , Ziolkowski Patryk
Published: October 2020

The technological process of concrete production consists of several parts, including concrete mix design, concrete mix production, transportation of fresh concrete mix to a construction site, placement in concrete framework, and curing. Proper execution of these steps provides good quality concrete. Some factors can disturb the technological process, mainly temperature and excessive precipitation. Changing daily temperature and rainfall during fabrication, transportation, and placement can shape not only the properties of the concrete mix but also the compressive strength of hardened concrete. In this paper, we tried to answer the question of how temperature and precipitation affect concrete production. The scope of this study was to determine the change of compressive strength of the hardened concrete in a specific period for selected concrete mix recipes, taking into account changing daily temperature and precipitation magnitude. The investigated concrete mixes concrete compressive strength beyond that of the concrete grade, termed “concrete superstrength”. This concrete post limiting behaviour of concrete is also discussed.
Analysis of Magnetic Anisotropy and Non-Homogeneity of S235 Ship Structure Steel after Plastic Straining by the Use of Barkhausen Noise
Authors: Jurkovič Martin , Kalina Tomáš , Zgútová Katarína , Neslušan Miroslav , Pitoňák Martin
Published: October 2020

This study investigates the microstructure, residual stress state, and the corresponding magnetic anisotropy of the ship structure samples made of S235 steel after uniaxial tensile deformation. A non-destructive magnetic technique based on Barkhausen noise is employed for fast and reliable monitoring of samples exposed to the variable degrees of plastic straining. It was found that the progressively developed plastic straining of the matrix results in an alteration of the easy axis of magnetization, stress anisotropy (expressed in residual stresses state) as well as the corresponding Barkhausen noise emission. Moreover, remarkable non-homogeneity can be found within the plastically strained region, especially when the localized plastic straining takes place.
Synthesis of Core–Shell Micro/Nanoparticles and Their Tribological Application: A Review
Authors: Chen Hao , Zhang Lin , Li Mengyu , Xie Guoxin
Published: October 2020

Owing to the diverse composition, adjustable performance, and synergistic effect among components, core–shell micro/nanoparticles have been widely applied in the field of tribology in recent years. The strong combination with the matrix and the good dispersion of reinforcing fillers in the composites could be achieved through the design of core–shell structural particles based on the reinforcing fillers. In addition, the performance of chemical mechanical polishing could be improved by optimizing the shell material coated on the abrasive surface. The physical and chemical state of the core–shell micro/nanoparticles played important effects on the friction and wear properties of materials. In this paper, the synthesis methods, the tribological applications (acted as solid/liquid lubricant additive, chemical mechanical polishing abrasives and basic units of lubricant matrix), and the functionary mechanisms of core–shell micro/nanoparticles were systematically reviewed, and the future development of core–shell micro/nanoparticles in tribology was also prospected.
An Analytical Method for Generating Determined Torque Ripple in Synchronous Machine with Interior Magnets by Harmonic Current Injection
Authors: Vollat Matthias , Li Junchao , Gauterin Frank
Published: October 2020

In this paper, we present an extension for an analytical method of calculating the required amplitudes and phase angles of the injected harmonic currents, to generate a determined torque ripple for synchronous machines. With the consideration of reluctance torque in the system equations, this method is valid not only for synchronous machines with surface magnets, but also for those with interior magnets. First, we describe the machine equations as a function of the phase current and the back electromotive force. We then introduce an analytical way to calculate the reluctance torque. After combining the equations, we establish a linear system of equations. The solution of the equation system yields the amplitudes and phase angles of the harmonic currents to be injected. Finally, we validate the equations for calculating the reluctance Torque and the method to generate the determined torque ripple with several finite element method simulations. This allowed us to generate the desired torque fluctuations even for synchronous machines with interior magnets.
A Survey on Blockchain Consensus with a Performance Comparison of PoW, PoS and Pure PoS
Authors: Lepore Cristian , Ceria Michela , Visconti Andrea , Rao Udai Pratap , Shah Kaushal Arvindbhai , Zanolini Luca
Published: October 2020

Blockchain technology started as the backbone for cryptocurriencies and it has emerged as one of the most interesting technologies of the last decade. It is a new paradigm able to modify the way how industries transact. Today, the industries’ concern is about their ability to handle a high volume of data transactions per second while preserving both decentralization and security. Both decentralization and security are guaranteed by the mathematical strength of cryptographic primitives. There are two main approaches to achieve consensus: the Proof-of-Work based blockchains—PoW—and the Proof-of-Stake—PoS. Both of them come with some pros and drawbacks, but both rely on cryptography. In this survey, we present a review of the main consensus procedures, including the new consensus proposed by Algorand: Pure Proof-of-Stake—Pure PoS. In this article, we provide a framework to compare the performances of PoW, PoS and the Pure PoS, based on throughput and scalability.
Estimating the Parameters of the Two-Parameter Rayleigh Distribution Based on Adaptive Type II Progressive Hybrid Censored Data with Competing Risks
Authors: Liu Shuhan , Gui Wenhao
Published: October 2020

This paper attempts to estimate the parameters for the two-parameter Rayleigh distribution based on adaptive Type II progressive hybrid censored data with competing risks. Firstly, the maximum likelihood function and the maximum likelihood estimators are derived before the existence and uniqueness of the latter are proven. Further, Bayesian estimators are considered under symmetric and asymmetric loss functions, that is the squared error loss function, the LINEXloss function, and the general entropy loss function. As the Bayesian estimators cannot be obtained explicitly, the Lindley method is applied to compute the approximate Bayesian estimates. Finally, a simulation study is conducted, and a real dataset is analyzed for illustrative purposes.
Forecasting the Demand for Container Throughput Using a Mixed-Precision Neural Architecture Based on CNN–LSTM
Authors: Yang Cheng-Hong , Chang Po-Yin
Published: October 2020

Forecasting the demand for container throughput is a critical indicator to measure the development level of a port in global business management and industrial development. Time-series analysis approaches are crucial techniques for forecasting the demand for container throughput. However, accurate demand forecasting for container throughput remains a challenge in time-series analysis approaches. In this study, we proposed a mixed-precision neural architecture to forecasting the demand for container throughput. This study is the first work to use a mixed-precision neural network to forecast the container throughput—the mixed-precision architecture used the convolutional neural network for learning the strength of the features and used long short-term memory to identify the crucial internal representation of time series depending on the strength of the features. The experiments on the demand for container throughput of the five ports in Taiwan were conducted to compare our deep learning architecture with other forecasting approaches. The results indicated that our mixed-precision neural architecture exhibited higher forecasting performance than classic machine learning approaches, including adaptive boosting, random forest regression, and support vector regression. The proposed architecture can effectively predict the demand for port container throughput and effectively reduce the costs of planning and development of ports in the future.
Dependence of Dynamics of a System of Two Coupled Generators with Delayed Feedback on the Sign of Coupling
Authors: Kashchenko Alexandra
Published: October 2020

In this paper, we study the nonlocal dynamics of a system of delay differential equations with large parameters. This system simulates coupled generators with delayed feedback. Using the method of steps, we construct asymptotics of solutions. By these asymptotics, we construct a special finite-dimensional map. This map helps us to determine the structure of solutions. We study the dependence of solutions on the coupling parameter and show that the dynamics of the system is significantly different in the case of positive coupling and in the case of negative coupling.
Existence and Multiplicity of Solutions to a Class of Fractional p-Laplacian Equations of Schrödinger-Type with Concave-Convex Nonlinearities in ℝN
Authors: Kim Yun-Ho
Published: October 2020

We are concerned with the following elliptic equations: (−Δ)psv+V(x)|v|p−2v=λa(x)|v|r−2v+g(x,v)inRN, where (−Δ)ps is the fractional p-Laplacian operator with 0<s<1<r<p<+∞, sp<N, the potential function V:RN→(0,∞) is a continuous potential function, and g:RN×R→R satisfies a Carathéodory condition. By employing the mountain pass theorem and a variant of Ekeland’s variational principle as the major tools, we show that the problem above admits at least two distinct non-trivial solutions for the case of a combined effect of concave–convex nonlinearities. Moreover, we present a result on the existence of multiple solutions to the given problem by utilizing the well-known fountain theorem.