bluuebunny/crossref_metadata_2025 huggingface dataset:
Solvent-Free Synthesis of Nickel Nanoparticles as Catalysts for CO2 Hydrogenation to Methane
Authors: Netskina Olga V. , Dmitruk Kirill A. , Paletsky Alexander A. , Mukha Svetlana A. , Pochtar Alena A. , Bulavchenko Olga A. , Prosvirin Igor P. , Shmakov Andrey G. , Ozerova Anna M. , Veselovskaya Janna V. , Mazina Olga I. , Komova Oxana V.
Published: October 2022

The solid-state combustion method was used to prepare nickel-based catalysts for CO2 hydrogenation from [Ni(C3H4N2)6](NO3)2 and [Ni(C3H4N2)6](ClO4)2. These complexes were synthesized by adding nickel nitrate and perchlorate to melted imidazole. The composition and structure of the obtained complexes was confirmed by ATR FTIR, powder XRD, and elemental analysis. The stages of thermal decomposition of the complexes and their kinetic parameters were established. It was found that incomplete gasification of more thermostable Ni(C3H4N2)6](ClO4)2 led to the formation of carbon, nitrogen, and chlorine impurities. According to powder XRD and XPS, the solid products of gasification of both complexes consist of NiO and Ni0 covered with nickel hydroxide and/or a carbonate layer. In the case of the sample prepared from [Ni(C3H4N2)6](ClO4)2, this layer was pronounced. Therefore, it limits the nickel reduction in the reaction medium of CO2 hydrogenation, even at 450 °C. The surface of the sample prepared from [Ni(C3H4N2)6](NO3)2 contains nickel oxide, which is easily reduced. So, the catalyst active phase is already formed at 250 °C in the presence of CO2 and efficiently catalyzes CO2 hydrogenation as the temperature increases. Therefore, [Ni(C3H4N2)6](NO3)2 is a promising precursor for the CO2 hydrogenation catalyst, and its solvent-free synthesis follows Green Chemistry principles.
Apelin Promotes Prostate Cancer Metastasis by Downregulating TIMP2 via Increases in miR-106a-5p Expression
Authors: Lin Tien-Huang , Chang Sunny Li-Yun , Khanh Pham Minh , Trang Nguyen Thi Nha , Liu Shan-Chi , Tsai Hsiao-Chi , Chang An-Chen , Lin Jo-Yu , Chen Po-Chun , Liu Ju-Fang , Guo Jeng-Hung , Liu Chun-Lin , Wu Hsi-Chin , Tang Chih-Hsin
Published: October 2022

Prostate cancer commonly affects the urinary tract of men and metastatic prostate cancer has a very low survival rate. Apelin belongs to the family of adipokines and is associated with cancer development and metastasis. However, the effects of apelin in prostate cancer metastasis is undetermined. Analysis of the database revealed a positive correlation between apelin level with the progression and metastasis of prostate cancer patients. Apelin treatment facilitates cell migration and invasion through inhibiting tissue inhibitor of metalloproteinase 2 (TIMP2) expression. The increasing miR-106a-5p synthesis via c-Src/PI3K/Akt signaling pathway is controlled in apelin-regulated TIMP2 production and cell motility. Importantly, apelin blockade inhibits prostate cancer metastasis in the orthotopic mouse model. Thus, apelin is a promising therapeutic target for curing metastatic prostate cancer.
Coming of Age for BTK Inhibitor Therapy: A Review of Zanubrutinib in Waldenström Macroglobulinemia
Authors: Muñoz Javier , Paludo Jonas , Sarosiek Shayna , Castillo Jorge J.
Published: October 2022

Waldenström macroglobulinemia (WM) is a rare form of non-Hodgkin B-cell lymphoma with a variable clinical presentation that can impact a patient’s quality of life by causing anemia, peripheral neuropathy, serum hyperviscosity, extramedullary disease, and other symptoms. There are several safe and effective treatment regimens for patients with WM, and the choice of therapy should be made in a personalized fashion considering the patient’s symptoms, comorbidities, and genomic profile. Bruton tyrosine kinase (BTK) inhibitors are a new option to treat patients with WM. Zanubrutinib is a next-generation covalent BTK inhibitor designed to have fewer off-target effects than previous BTK inhibitors. This review summarizes the pharmacokinetic and pharmacodynamic properties of zanubrutinib as well as safety and efficacy findings. Then, it explores the health economic and outcomes research associated with the costs of treating patients with WM and the reasons why zanubrutinib may be a more cost-effective treatment option compared with ibrutinib, a first-generation BTK inhibitor. Future directions for the treatment of WM focus on the use of zanubrutinib in combination therapy. Combinations based on effective ibrutinib or acalabrutinib treatments may be effectively applied with zanubrutinib given the similar mechanism of action for these BTK inhibitors. Combination therapies could also help prevent the development of disease resistance, minimize toxicity, and support treatment regimens of finite duration.
Unraveling Differential Transcriptomes and Cell Types in Zebrafish Larvae Intestine and Liver
Authors: Gao Yuqi , Jin Qingxia , Gao Ce , Chen Yayue , Sun Zhaoxiang , Guo Guoji , Peng Jinrong
Published: October 2022

The zebrafish intestine and liver, as in other vertebrates, are derived from the endoderm. Great effort has been devoted to deciphering the molecular mechanisms controlling the specification and development of the zebrafish intestine and liver; however, genome-wide comparison of the transcriptomes between these two organs at the larval stage remains unexplored. There is a lack of extensive identification of feature genes marking specific cell types in the zebrafish intestine and liver at 5 days post-fertilization, when the larval fish starts food intake. In this report, through RNA sequencing and single-cell RNA sequencing of intestines and livers separately dissected from wild-type zebrafish larvae at 5 days post-fertilization, together with the experimental validation of 47 genes through RNA whole-mount in situ hybridization, we identified not only distinctive transcriptomes for the larval intestine and liver, but also a considerable number of feature genes for marking the intestinal bulb, mid-intestine and hindgut, and for marking hepatocytes and cholangiocytes. Meanwhile, we identified 135 intestine- and 97 liver-enriched transcription factor genes in zebrafish larvae at 5 days post-fertilization. Our findings provide rich molecular and cellular resources for studying cell patterning and specification during the early development of the zebrafish intestine and liver.
Endophyte-Mediated Stress Tolerance in Plants: A Sustainable Strategy to Enhance Resilience and Assist Crop Improvement
Authors: Kamran Muhammad , Imran Qari Muhammad , Ahmed Muhammad Bilal , Falak Noreen , Khatoon Amna , Yun Byung-Wook
Published: October 2022

Biotic and abiotic stresses severely affect agriculture by affecting crop productivity, soil fertility, and health. These stresses may have significant financial repercussions, necessitating a practical, cost-effective, and ecologically friendly approach to lessen their negative impacts on plants. Several agrochemicals, such as fertilizers, pesticides, and insecticides, are used to improve plant health and protection; however, these chemical supplements have serious implications for human health. Plants being sessile cannot move or escape to avoid stress. Therefore, they have evolved to develop highly beneficial interactions with endophytes. The targeted use of beneficial plant endophytes and their role in combating biotic and abiotic stresses are gaining attention. Therefore, it is important to experimentally validate these interactions and determine how they affect plant fitness. This review highlights research that sheds light on how endophytes help plants tolerate biotic and abiotic stresses through plant–symbiont and plant–microbiota interactions. There is a great need to focus research efforts on this vital area to achieve a system-level understanding of plant–microbe interactions that occur naturally.
USP7 Induces Chemoresistance in Triple-Negative Breast Cancer via Deubiquitination and Stabilization of ABCB1
Authors: Lin Yueh-Te , Lin Joseph , Liu Yi-En , Chen Yun-Cen , Liu Shiang-Ting , Hsu Kai-Wen , Chen Dar-Ren , Wu Han-Tsang
Published: October 2022

Triple-negative breast cancer (TNBC) accounts for 15–20% of all breast cancer. TNBC does not express the estrogen receptor, progesterone receptor, or human epidermal growth factor receptor 2. Cytotoxic chemotherapy and surgery are the current therapeutic strategies for TNBC patients, but the chemoresistance of TNBC limits the efficiency of this strategy and shortens the lifespan of patients. The exploration of targeted therapy is ongoing in TNBC research. The aim of the present study was to identify the mechanism underlying acquired resistance in TNBC through the exploration of the relationship between the expression of USP7 and of ABCB1. We found that ubiquitin specific protease 7 (USP7) is a potential therapeutic target for overcoming the chemoresistance of TNBC. USP7 overexpression increased the chemoresistance of TNBC, while the knockdown of USP7 effectively increased the chemosensitivity of chemoresistant TNBC. A USP7 inhibitor effectively induced apoptosis and suppressed metastasis in chemoresistant TNBC. We further clarified that USP7 is a specific deubiquitinating enzyme for ABCB1 that plays an essential role in drug resistance. USP7 directly interacted with ABCB1 and regulated its stability. We concluded that USP7 promotes the chemoresistance of TNBC by stabilizing the ABCB1 protein.
Prospects of Application of Ultramicroelectrode Ensembles for Voltammetric Determination of Compounds with Close Standard Electrode Potentials and Different Diffusion Coefficients
Authors: Arbenin Andrey Yu. , Petrov Alexey A. , Nazarov Denis V. , Serebryakov Evgeny , Kirichenko Sergey O. , Vlasov Petr S. , Zemtsova Elena G. , Smirnov Vladimir M. , Danilova Elena E. , Ermakov Sergey S. , Vorobyov Alexander , Mukhin Mikhail S. , Mozharov Alexey M.
Published: October 2022

The spherical diffusion that occurs when using ultramicroelectrodes (i.e., electrodes with a characteristic size of 1–10 µm) contributes to a higher mass transfer rate. This leads to equalization of the depletion rates of the near-electrode layer due to the electrochemical reaction and to the supply of the product from the solution depth. This is the reason why, for ultramicroelectrodes, a limiting size of the spherical layer exists in which the concentration gradient is localized (diffusion layer). Thus, a stationary mass transfer mode is achieved, which is expressed in the sigmoidal CV curve’s shape. In ultramicroelectrode arrays, when the diffusion hemispheres are separated, a steady-state diffusion is realized. However, with a decrease in the interelectrode distance, which leads to the diffusion spheres intersection, a mixed regime arises, which is not fully time-independent. The resulting voltammogram’s shape change can serve as an analytical signal in the study of substances with differing diffusion coefficients, since the diffusion layer growth rate and, consequently, the area of intersection of neighboring spheres, depends on it. This work shows the applicability of voltammetry using ensembles of ultramicroelectrodes operating in the transient mode for the analysis of mixtures of electrochemically active compounds with close electrode reaction parameters, such as exchange currents and electrode potential. Ferrocenemethanol esters are used as an example. The applicability of cyclic voltammetry on the UME array for analysis of mixtures was illustrated by means of finite element modelling. The reliability of the modelling results was experimentally proved for ferrocenemethanol esters with glycine and triglycine.
Flow Injection Sensing Strategy for Determining Cationic Surfactants in Commodity and Water Samples
Authors: El Hamd Mohamed A. , El-Maghrabey Mahmoud , Abdel-Lateef Mohamed A. , Ali Samah M. , Ibrahim Munjed M. , El-Shahat Mohamed F. , Azeem Sami M. Abdel
Published: October 2022

The formation of stable binary water-soluble sub-micellar aggregates of cetyltrimethylammonium bromide-copper-pyrocatechol violet complex (CTAB-Cu-PCV) diminishes the stability and absorbance of the Cu-PCV complex. A new flow injection spectrophotometric sensing strategy used for the determination of CTAB in commodity personal care antiseptics and water samples has been established relying on the above-mentioned concept. Based on the reduction of the absorption of the Cu-PCV solution by the injection of CTAB solution at pH 6.0 and 430 nm, a linear absorbance decrease was observed over the CTAB concentration range of 2.0 to 100.0 µg mL−1 (r = 0.987). The analysis method showed limits of detection (3.3 ơ) and quantification (10 ơ) of 0.08 and 0.27 µg mL−1, respectively. The precision (RSD) for five replicate determinations was 7.9 and 3.7% at 10 and 50 µg mL−1, respectively. The developed method was applied successfully to the determination of CTAB in personal care products, namely skin lotion and vaginal wash, in addition to water samples. The corresponding RSD (n = 5) values were ≤8.2%.
The Laparoscopic Cholecystectomy and Common Bile Duct Exploration: A Single-Step Treatment of Pediatric Cholelithiasis and Choledocholithiasis
Authors: Pogorelić Zenon , Lovrić Marko , Jukić Miro , Perko Zdravko
Published: October 2022

Background: In recent years, complicated biliary tract diseases are increasingly diagnosed in children. Laparoscopic exploration of the common bile duct (LCBDE) followed by laparoscopic cholecystectomy has gained popularity in children. The aim of this study was to investigate the outcomes of LCBDE in children and compare them with the treatment outcomes of previously used endoscopic retrograde cholangiopancreatography (ERCP). Methods: From January 2000 to January 2022, a total of 84 children (78.5% female) underwent laparoscopic cholecystectomy with a median follow-up of 11.4 (IQR 8, 14) years. Of these, 6 children underwent laparoscopic cholecystectomy (LC) + ERCP and 14 children underwent LCBDE for choledochiothiasis. The primary end point of the study was the success of treatment in terms of the incidence of complications, recurrence rate, and rate of reoperation. Secondary endpoints were stone characteristics, presenting symptoms, duration of surgery, and length of hospital stay. Results: The majority of patients were female in both groups (83.5% vs. 85.7%), mostly overweight with a median BMI of 27.9 kg/m2 and 27.4 kg/m2, respectively. Obstructive jaundice, colicky pain, acute pancreatitis, and obstruction of the papilla were the most common symptoms in both groups. The majority of patients (68%) had one stone, whereas two or more stones were found in 32% of patients. The median diameter of the common bile duct was 9 mm in both groups. The procedure was successfully completed in all patients in the ERCP group. In the group of patients treated with LCBDE, endoscopic extraction of the stone with a Dormia basket was successfully performed in ten patients (71.4%), while in the remaining four patients (28.6%) the stones were fragmented with a laser because extraction with the Dormia basket was not possible. The median operative time was 79 min in the LCBDE group (IQR 68, 98), while it was slightly longer in the ERCP group, 85 min (IQR 74, 105) (p = 0.125). The length of hospital stay was significantly shorter in the LCBDE group (2 vs. 4 days, p = 0.011). No complications occurred in the LCBDE group, while two (40%) complications occurred in the ERCP group: pancreatitis and cholangitis (p = 0.078). During the follow-up period, no conversions, papillotomies, or recurrences were recorded in either group. Conclusions: Exploration of the common bile duct and removal of stones by LCBDE is safe and feasible in pediatric patients for the treatment of choledocholithiasis. Through this procedure, choledocholithiasis and cholelithiasis can be treated in a single procedure without papillotomy or fluoroscopy. Compared with LC + ERCP, LCBDE is associated with a shorter hospital stay. The incidence of complications was rather low but not statistically significant.
Current Management of Generalized Convulsive Status Epilepticus in Children
Authors: Aulická Štefania
Published: October 2022

Generalized convulsive status epilepticus (GCSE) in pediatric patients is an emergency condition with high morbidity and mortality and potentially irreversible brain damage, leading to cognitive deterioration, psychomotor retardation, chronic epilepsy with recurring seizures, and other complications. Treatment must be initiated in the impending GCSE phase, within five minutes of the onset of a generalized convulsive seizure. Early initiation of treatment and adequate therapy is a prerequisite for a good patient outcome.
On the Validity of a Linearity Axiom in Diffusion and Heat Transfer
Authors: Arya Raj Kumar , Thapliyal Devyani , Verros George D. , Singh Neetu , Singh Dhananjay , Kumar Rahul , Srivastava Rajesh Kumar , Tiwari Anurag Kumar
Published: October 2022

In this work, the linearity axiom of irreversible thermodynamics for diffusion and heat transfer has been re-examined. It is shown that this axiom is compatible with the entropy production invariance principle with respect to a reference quantity for diffusion and heat transfer in the Euclidean space. Moreover, the underlying relations of the other principles of irreversible thermodynamics for multi-component diffusion and heat transfer, such as the quasi-equilibrium and the Onsager reciprocal relations (ORR) with the entropy production invariance, are re-examined. It was shown that the linearity principle postulates for diffusion and heat transfer and could be directly derived from the entropy production invariance axiom. It is believed that this work could not only be used for the drying of polymer coatings but also for pedagogical purposes. It may also be generalized; thus, leading to a generalized framework for irreversible thermodynamics.
Mechanism of Action of Topical Tranexamic Acid in the Treatment of Melasma and Sun-Induced Skin Hyperpigmentation
Authors: Maeda Kazuhisa
Published: October 2022

Tranexamic acid (TXA) has anti-plasmin activity and has been shown when administered orally to be effective against melasma, for which it is considered first-line pharmacotherapy. Several studies have shown that topically applied TXA is also effective against melasma and skin hyperpigmentation caused by sunburn and inflammation. The TXA concentration in the epidermis and dermis/vasculature has been estimated from its distribution in the skin after closed application, and topically applied TXA has thus been shown to act on neutrophils and mast cells in the dermis and on the vascular system. It is unlikely that topically applied TXA acts on dermal neutrophils or mast cells or on the vascular system to form thrombi. As discussed in the present review, studies on the effects of topical TXA on the hyperpigmentation process indicate that the resulting skin-lightening mechanism involves the suppression of cytokine/chemical mediator production, which stimulates melanin production via the keratinocyte-derived urokinase-type plasminogen activator and plasminogen derived from dermal vascular in the basal layer of the epidermis, thereby suppressing the production of excessive melanin to prevent hyperpigmentation.
Determination of Cooling Rate and Temperature Gradient during Formation of Cathode Spot Craters in a Vacuum Arc
Authors: Mogeritsch Johann Peter , Franz Robert , Golizadeh Mehran , Mitterer Christian , Kharicha Abdellah
Published: October 2022

Due to the extreme thermal conditions and short lifetimes, experimental exploration of cathode spots in vacuum arcs is very difficult. The intensive heat in the cathode spot is believed to be generated by ion bombardment and by Joule heating. However, thermal conditions occurring inside the re-melted material in craters created by cathode spots are not accurately known. During the exposure to cathodic arc plasmas, an Al-Cr cathode’s surface was locally melted by successive ignition and extinction of cathode spots. The melted layer, that quickly solidified, was characterized by the formation of several thin layers with a thickness of a few micrometers that were stacked on top of each other. The corresponding solidification patterns displayed cellular and dendritic microstructures. A phase field-based model was used to simulate and determine the thermal process conditions that led to the dendritic structures observed within the re-melted layer. Different combinations of cooling rates and temperature gradients were numerical explored to determine the most probable thermal conditions under which the cathode material re-solidifies. The results showed that the material in the vicinity of the cathode spot crater re-solidified under the condition of a cooling rate of about 3 × 105 K/s and a temperature gradient of about 6 × 107 K/m. These results constitute valuable data for the validation of numerical models dedicated to cathode spot formation.
Application of Machine Learning Techniques for Characterization of Ischemic Stroke with MRI Images: A Review
Authors: Subudhi Asit , Dash Pratyusa , Mohapatra Manoranjan , Tan Ru-San , Acharya U. Rajendra , Sabut Sukanta
Published: October 2022

Magnetic resonance imaging (MRI) is a standard tool for the diagnosis of stroke, but its manual interpretation by experts is arduous and time-consuming. Thus, there is a need for computer-aided-diagnosis (CAD) models for the automatic segmentation and classification of stroke on brain MRI. The heterogeneity of stroke pathogenesis, morphology, image acquisition modalities, sequences, and intralesional tissue signal intensity, as well as lesion-to-normal tissue contrast, pose significant challenges to the development of such systems. Machine learning (ML) is increasingly being used in predictive neuroimaging diagnosis and prognostication. This paper reviews image processing and machine learning techniques that have been applied to detect ischemic stroke on brain MRI, including details on image acquisition, pre-processing, techniques to segment, extraction of features, and classification into stroke types. The main objective of this work is to find the state-of-art machine learning techniques used to predict the ischemic stroke and their application in clinical set-up. The article selection is performed according to PRISMA guideline. The state-of-the-art on automated MRI stroke diagnosis, with a focus on machine learning, is discussed, along with its advantages and limitations. We found that the various machine learning models discussed in this article are able to detect the infarcts with an acceptable accuracy of 70–90%. However, no one has highlighted the time complexity to predict the stroke in the model developed, which is an important factor. The work concludes with proposals for future recommendations for building efficient and robust deep learning (DL) models for quantitative brain MRI analysis. In recent work, with the application of DL approaches, using large datasets to train the models has improved the detection accuracy and reduced computational complexity. We suggest that the design of a decision support system based on artificial intelligence (AI) and clinical data presenting symptoms is essential to support clinicians to accelerate diagnosis and timeous therapy in the emergency management of stroke.
Automatic Cardiopulmonary Endurance Assessment: A Machine Learning Approach Based on GA-XGBOOST
Authors: Deng Jia , Fu Yan , Liu Qi , Chang Le , Li Haibo , Liu Shenglin
Published: October 2022

Objective: Among various assessment paradigms, the cardiopulmonary exercise test (CPET) provides rich evidence as part of the cardiopulmonary endurance (CPE) assessment. However, methods and strategies for interpreting CPET results are not in agreement. The purpose of this study is to validate the possibility of using machine learning to evaluate CPET data for automatically classifying the CPE level of workers in high-latitude areas. Methods: A total of 120 eligible workers were selected for this cardiopulmonary exercise experiment, and the physiological data and completion of the experiment were recorded in the simulated high-latitude workplace, within which 84 sets of data were used for XGBOOST model training and36 were used for the model validation. The model performance was compared with Support Vector Machine and Random Forest. Furthermore, hyperparameter optimization was applied to the XGBOOST model by using a genetic algorithm. Results: The model was verified by the method of tenfold cross validation; the correct rate was 0.861, with a Micro-F1 Score of 0.864. Compared with RF and SVM, all data achieved a better performance. Conclusion: With a relatively small number of training samples, the GA-XGBOOST model fits well with the training set data, which can effectively evaluate the CPE level of subjects, and is expected to provide automatic CPE evaluation for selecting, training, and protecting the working population in plateau areas.
The Interpretation of Graphical Information in Word Processing
Authors: Csernoch Mária , Máth János , Nagy Tímea
Published: October 2022

Word processing is one of the most popular digital activities. Despite its popularity, it is haunted by false assumptions, misconceptions, and ineffective and inefficient practices leading to erroneous digital text-based documents. The focus of the present paper is automated numbering and distinguishing between manual and automated numbering. In general, one bit of information on the GUI—the position of the cursor—is enough to tell whether a numbering is manual or automated. To decide how much information must be put on the channel—the teaching–learning process—in order to reach end-users, we designed and implemented a method that includes the analysis of teaching, learning, tutorial, and testing sources, the collection and analysis of Word documents shared on the internet or in closed groups, the testing of grade 7–10 students’ knowledge in automated numbering, and calculating the entropy of automated numbering. The combination of the test results and the semantics of the automated numbering was used to measure the entropy of automated numbering. It was found that to transfer one bit of information on the GUI, at least three bits of information must be transferred during the teaching–learning process. Furthermore, it was revealed that the information connected to numbering is not the pure use of tools, but the semantics of this feature put into a real-world context.
A Hierarchy of Probability, Fluid and Generalized Densities for the Eulerian Velocivolumetric Description of Fluid Flow, for New Families of Conservation Laws
Authors: Niven Robert
Published: October 2022

The Reynolds transport theorem occupies a central place in continuum mechanics, providing a generalized integral conservation equation for the transport of any conserved quantity within a fluid or material volume, which can be connected to its corresponding differential equation. Recently, a more generalized framework was presented for this theorem, enabling parametric transformations between positions on a manifold or in any generalized coordinate space, exploiting the underlying continuous multivariate (Lie) symmetries of a vector or tensor field associated with a conserved quantity. We explore the implications of this framework for fluid flow systems, based on an Eulerian velocivolumetric (position-velocity) description of fluid flow. The analysis invokes a hierarchy of five probability density functions, which by convolution are used to define five fluid densities and generalized densities relevant to this description. We derive 11 formulations of the generalized Reynolds transport theorem for different choices of the coordinate space, parameter space and density, only the first of which is commonly known. These are used to generate a table of integral and differential conservation laws applicable to each formulation, for eight important conserved quantities (fluid mass, species mass, linear momentum, angular momentum, energy, charge, entropy and probability). The findings substantially expand the set of conservation laws for the analysis of fluid flow and dynamical systems.
Factors Constraining Teachers’ Wellbeing and Agency in a Finnish University: Lessons from the COVID-19 Pandemic
Authors: Mäkelä Tiina , Sikström Pieta , Jääskelä Päivikki , Korkala Salme , Kotkajuuri Jimi , Kaski Saara , Taalas Peppi
Published: October 2022

The COVID-19 pandemic forced teachers to undergo a sudden shift toward technology-enhanced teaching and learning, challenging their capacities for change in many ways. This study explores those factors constraining teachers’ wellbeing and agency that influenced their capacities as teachers in a Finnish university during the first year of the pandemic. Two sets of data were collected, with an online survey in the spring (n = 297) and autumn (n = 246) of 2020. At both times, challenges with workload, time management, and interactions with colleagues were found to be the most constraining factors. Difficulties with work–life balance and home office facilities seemed more of an issue in the spring, whereas transforming teaching and adopting new technological tools were reported as more burdensome in the autumn. The findings show the need for teachers to be heard and holistically supported, particularly when extensive changes in teaching arrangements are expected on a rapid schedule.
Design and Analysis of Novel Reconfigurable Monopole Antenna Using Dip Switch and Covering 5G-Sub-6-GHz and C-Band Applications
Authors: Abd Ali Kadhum , Rasool Jamal Mohammed , Rahman Zain-Aldeen S. A. , Al-Yasir Yasir I. A.
Published: October 2022

This study presents a unique frequency-reconfigurable antenna that may be the first to use a dip switch and a bias circuit integrated on the same substrate as the antenna. Such an antenna may be used for many wireless applications, since it is small and versatile enough to operate in several frequency bands with different modes. Printed on a Rogers RT5880 substrate, the suggested structure has a relative permittivity of 2.2, a tangent loss of 0.0009, and a size of 28 × 26.35 × 1.6 mm3. Three-PIN diode switches are inserted between radiating patches. The proposed antenna operates in four modes, covering nine different bands by using three dual bands (i.e., 4.36 and 7.78 GHz, 3.56 and 6.89 GHz, 3 and 6.2 GHz) in MODE 1, MODE 2, and MODE three, respectively, and triple band in MODE 4 (i.e., 2.88, 5.87, and 8.17 GHz). The efficiency of the planned antenna is 97.66%, and the gain varies from 1.38 to 4.89 dBi. The obtained bandwidths at corresponding frequencies range from 5.5 to 31.17%. The suggested structure is modeled in the CSTMWS and the simulated findings are experimentally confirmed. The suggested antenna may be employed in current portable (5G) devices and the IoT.
ASK-ViT: A Model with Improved ViT Robustness through Incorporating SK Modules Using Adversarial Training
Authors: Chang Youkang , Zhao Hong , Wang Weijie
Published: October 2022

The ViTs model has been widely used since it was proposed, and its performance on large-scale datasets has surpassed that of CNN models. In order to deploy the ViTs model safely in practical application scenarios, its robustness needs to be investigated. There are few studies on the robustness of ViT model, therefore, this study investigates the robustness of the ViT model in the face of adversarial example attacks, and proposes the ASK-ViT model with improving robustness by introducing the SK module. The SK module consists of three steps, Split, Fuse and Select, which adaptively select the size of the perceptual field according to the input of multi-scale information, and extracts the features that help the model to classify examples. In addition, adversarial training is used in the training process. Experimental results show that the accuracy of the proposed defense method against C&W, DI2FGSM, MDI2FGSM, ImageNet-A, and ImageNet-R attacks is 30.104%, 29.146%, 28.885%, 29.573%, and 48.867%, respectively. Compared with other methods, the method in this study shows stronger robustness.
Relative Knowledge Distance Measure of Intuitionistic Fuzzy Concept
Authors: Yang Jie , Qin Xiaodan , Wang Guoyin , Zhang Xiaoxia , Wang Baoli
Published: October 2022

Knowledge distance is used to measure the difference between granular spaces, which is an uncertainty measure with strong distinguishing ability in a rough set. However, the current knowledge distance failed to take the relative difference between granular spaces into account under the given perspective of uncertain concepts. To solve this problem, this paper studies the relative knowledge distance of intuitionistic fuzzy concept (IFC). Firstly, a micro-knowledge distance (md) based on information entropy is proposed to measure the difference between intuitionistic fuzzy information granules. Then, based on md, a macro-knowledge distance (MD) with strong distinguishing ability is further constructed, and it is revealed the rule that MD is monotonic with the granularity being finer in multi-granularity spaces. Furthermore, the relative MD is further proposed to analyze the relative differences between different granular spaces from multiple perspectives. Finally, the effectiveness of relative MD is verified by relevant experiments. According to these experiments, the relative MD has successfully measured the differences in granular space from multiple perspectives. Compared with other attribute reduction algorithms, the number of subsets after reduction by our algorithm is in the middle, and the mean-square error value is appropriate.
The Design of a Safe Charging System Based on PKS Architecture
Authors: Zeng Jianhong , Zhang Yi , Xue Youhua , Li Wenqi , Li Jing , Zhang Linchao , Zheng Shipu
Published: October 2022

With the development of new energy vehicles, information sharing and charging service-sharing in the Internet of Vehicles have become popular directions in smart city research. The number of new energy vehicles has surged, and the ensuing range anxiety and low charging efficiency have become the main problems to be solved urgently in charging services. In the era of big data, privacy leakage is becoming more and more serious, and information security and privacy protection cannot be delayed. This paper proposes an efficient charging and privacy protection system based on the PKS system. The original single-stage topology is improved by adding the PFC and LLC circuit topologies. The PID method is used to precisely control the voltage and current loss to improve the conversion efficiency of the charging pile. The private data in the shared information uses the RSA encryption algorithm to prevent the leakage of private data and enhance the security of system communication. This paper aims to improve the charging efficiency of charging piles and the security of private information in network communication. Simulation experiments are carried out on the proposed hardware topology and software encryption system scheme. Experiments compare the waveform state of the improved output current and voltage and the safety protection area of the system architecture. The results show that the proposed charging system is efficient and safe.
Research on Wide Input Voltage LLC Resonant Converter and Compound Control Strategy
Authors: Zhou Kai , Liu Yang , Wu Xiaogang
Published: October 2022

This paper presents a wide input voltage vehicle DC/DC converter based on an LLC resonant converter for a 48 V light hybrid power system. According to the design requirements of on-board DC/DC converters and an analysis of their system characteristics, a full-bridge LLC resonant converter is employed with a zero-voltage activation of the switching transistors through resonant elements. In terms of the control strategy, the unsatisfactory high-frequency regulation gain of an LLC resonant converter is analyzed under the frequency modulation (FM) control strategy. In addition, to accommodate wide input voltage operating conditions, a composite control strategy is proposed by combining the advantages of the frequency modulation control strategy and phase shift control strategy, analyzing their control principles, and discussing the selection of the control mode switching point. By modeling LLC resonant converters with simulation software, the obtained results verify the effectiveness of the composite control strategy for LLC resonant converters. An experimental platform based on the TMS320F28335 controller, which can achieve stable operation with an input voltage in the range of 300 V–600 V and an output voltage of 48 V, is then built. The experimental results verify the feasibility of the design.
Context-Aware Sleep Health Recommender Systems (CASHRS): A Narrative Review
Authors: Liang Zilu
Published: October 2022

The practice of quantified-self sleep tracking has become increasingly common among healthy individuals as well as patients with sleep problems. However, existing sleep-tracking technologies only support simple data collection and visualization and are incapable of providing actionable recommendations that are tailored to users’ physical, behavioral, and environmental context. A promising solution to address this gap is the context-aware sleep health recommender system (CASHRS), an emerging research field that bridges ubiquitous sleep computing and context-aware recommender systems. This paper presents a narrative review to analyze the type of contextual information, the recommendation algorithms, the context filtering techniques, the behavior change techniques, the system evaluation, and the challenges identified in peer-reviewed publications that meet the characteristics of CASHRS. The analysis results identified current research trends, the knowledge gap, and future research opportunities in CASHRS.
Augmented Lagrangian-Based Reinforcement Learning for Network Slicing in IIoT
Authors: Qi Qi , Lin Wenbin , Guo Boyang , Chen Jinshan , Deng Chaoping , Lin Guodong , Sun Xin , Chen Youjia
Published: October 2022

Network slicing enables the multiplexing of independent logical networks on the same physical network infrastructure to provide different network services for different applications. The resource allocation problem involved in network slicing is typically a decision-making problem, falling within the scope of reinforcement learning. The advantage of adapting to dynamic wireless environments makes reinforcement learning a good candidate for problem solving. In this paper, to tackle the constrained mixed integer nonlinear programming problem in network slicing, we propose an augmented Lagrangian-based soft actor–critic (AL-SAC) algorithm. In this algorithm, a hierarchical action selection network is designed to handle the hybrid action space. More importantly, inspired by the augmented Lagrangian method, both neural networks for Lagrange multipliers and a penalty item are introduced to deal with the constraints. Experiment results show that the proposed AL-SAC algorithm can strictly satisfy the constraints, and achieve better performance than other benchmark algorithms.
A PDR/WiFi Indoor Navigation Algorithm Using the Federated Particle Filter
Authors: Chen Jian , Song Shaojing , Liu Zhihui
Published: October 2022

This paper offers a solution to challenge navigation in the indoor environment by making use of the existing infrastructure. Estimating pedestrian trajectory using pedestrian dead reckoning (PDR) and WiFi is a very popular technique. However, cumulative errors and mismatching are major problems in PDR and WiFi fingerprint matching, respectively. PDR and pedestrian heading are used as the state transition equation, and the step length and WiFi matching results are used as observation equations. A federated particle filter (FPF) based on the principle of information sharing is proposed to fusion PDR and WiFi, which improves pedestrian navigation accuracy. The experimental results show that the average positioning accuracy is 0.94 m and 1.5 m, respectively.
EMC Analysis of the Inverting Boost/Buck Converter Topology
Authors: Kircher Daniel , Pommerenke David Johannes
Published: October 2022

This paper describes the electromagnetic compatibility (EMC) analysis of an inverting buck/boost converter. The inverting buck/boost converter differs from other DC/DC converters, such as the noninverting boost or buck converters, in that one inductor terminal is connected to the ground and not to the input or output of the converter, i.e., neither input nor output is isolated from an EMC perspective. A SPICE model was developed for analyzing the EMC properties of the circuit. Two electromagnetic interference EMI-relevant resonances were observed depending on the state of the switch. Simulations are confirmed with measurements using a circuit designed from discrete components. Further, integrated commercially available converters were analyzed and showed EMC properties that were similar to those of the general model.
Reducing Hardware in LUT-Based Mealy FSMs with Encoded Collections of Outputs
Authors: Barkalov Alexander , Titarenko Larysa , Mazurkiewicz Małgorzata
Published: October 2022

A method is proposed that is focused on reducing the chip area occupied by logic elements creating the circuit of Mealy finite state machines (FSMs). The proposed method is aimed at FSM circuits implemented with internal resources of field-programmable gate arrays (FPGA). The required chip area is estimated by the number of look-up table (LUT) elements in a particular circuit. The method is based on mutual application of two methods of structural decomposition. The first of them is based on dividing the set of outputs and using unitary-maximum encoding of collections of FSM outputs. The second method is based on dividing the set of states by classes of compatible states. The optimization is achieved by replacing the maximum binary state codes by two-part codes proposed in this article. Each two-part state code consists of a code of a class including a particular state and a maximum binary code of this state inside a particular class. The proposed approach leads to three-level LUT-based Mealy FSM circuits. The first logic level generates three types of partial functions: unitary encoded outputs, variables encoding collections of outputs, and input memory functions. Each partial function is represented by a circuit including a single LUT. The LUTs from the second logic level generate final values of these functions. The LUTs from the third level implement outputs using collections of outputs. An example of synthesis applying the proposed method is discussed. The experiments were conducted using standard benchmark FSMs. Their results showed significant improving of the area occupied by an FSM circuit. The LUT count decreased on average by 9.49%. The positive side effect of the proposed method was increasing the value of the maximum operating frequency (on average, by 8.73%). The proposed method is advisable to use if a single-level LUT-based implementation of the FSM circuit is impossible.
Community Energy Markets with Battery Energy Storage Systems: A General Modeling with Applications
Authors: Guedes Wanessa , Deotti Lucas , Dias Bruno , Soares Tiago , de Oliveira Leonardo Willer
Published: October 2022

Traditional models of power systems are undergoing a restructuring process, stimulated by the growing deployment of renewable energy sources, making them more decentralized and progressively increasing the focus on the consumer. New arrangements are being explored, allowing consumers to play a more active role in energy systems, highlighting the concept of consumer-centric markets. This work presents an optimization model that considers the insertion of the battery energy storage system (BESS) in the concept of community energy markets. This model aims to increase the community income and includes the degradation of BESS, also evaluating different arrangements of BESS in the community markets. In the investigated scenarios, discussions about the feasibility of inserting BESS through the analysis of social welfare (SW) and fairness indicators were carried out. With the results, it was possible to observe that there are structures that are more advantageous from the perspective of the communities and others from the perspective of the members of the communities, bringing some insights into the different impacts of a BESS in an energy community.
A Dual-Harmonic Pole-Changing Motor with Split Permanent Magnet Pole
Authors: Du Yi , Zhou Jiayan , He Zhuofan , Sun Yandong , Kong Ming
Published: October 2022

This paper proposes a dual-harmonic pole-changing (PC) motor with split permanent magnet (PM) poles (DHPCM-SPMPs). By adopting a split PM pole structure, the amplitude of the third PM flux density is increased greatly. Therefore, when a PC winding is adopted to couple with the fundamental and third PM flux density components, respectively, the proposed motor can work as a PC PM motor to satisfy operating demands of electric tractors. The design and effect of the proposed split PM pole structure is introduced first. The winding topology is then designed according to the slot vector diagrams of the two PM flux density components, and the PC operation can be realized by electric switches. Aiming at a torque ratio design objective, the PM structure parameters can be determined based on mathematical derivation, and the speed-widening capability is proved based on the operation characteristic analysis. Finally, the electromagnetic performance of the DHPCM-SPMPs is investigated and compared by finite element analysis, which shows the high torque capability in eight-pole mode and the wide speed range in twenty-four-pole mode benefiting from the PC operation.
Scientometric Review and Thematic Areas for the Research Trends on Marine Hoses
Authors: Amaechi Chiemela Victor , Ja’e Idris Ahmed , Reda Ahmed , Ju Xuanze
Published: October 2022

For over three (3) decades, there has been an increase in research on energy sources from the production of oil using flexible marine risers, such as marine hoses. Marine hoses are conduits for special use as rubberized structures with hybrid polymer composites for offshore platforms in the oil and gas industry. This scientometric study uses qualitative, quantitative, and computational approaches. Data were retrieved using a research methodology that was created for this study using the SCOPUS and Web of Science (WoS) databases. This study provides a bibliometric literature review on marine hoses with an emphasis on the advancements made in the field from recent developments, geographical activity by countries, authorship histories, partnerships, funding sources, affiliations, co-occurrences, and potential research areas. The study found that the USA had the most publications, but there were fewer co-occurrences with connections outside the cluster. Due to the difficulty of adaptation, acceptability, qualification, and deployment of marine hoses in the offshore marine industry, this topic contains more conference papers than journal papers. Therefore, more funding sources and collaborations on marine hoses are required to advance the research. This study makes a contribution to scholarship on advances made in petroleum exploration and production for (un)loading hoses.