bluuebunny/crossref_metadata_2025 huggingface dataset:
A Semi-Federated Active Learning Framework for Unlabeled Online Network Data
Authors: Zhou Yuwen , Hu Yuhan , Sun Jing , He Rui , Kang Wenjie
Published: April 2023

Federated Learning (FL) is a newly emerged federated optimization technique for distributed data in a federated network. The participants in FL that train the model locally are classified into client nodes. The server node assumes the responsibility to aggregate local models from client nodes without data moving. In this regard, FL is an ideal solution to protect data privacy at each node of the network. However, the raw data generated on each node are unlabeled, making it impossible for FL to apply these data directly to train a model. The large volume of data annotating work prevents FL from being widely applied in the real world, especially for online scenarios, where the data are generated continuously. Meanwhile, the data generated on different nodes tend to be differently distributed. It has been proved theoretically and experimentally that non-independent and identically distributed (non-IID) data harm the performance of FL. In this article, we design a semi-federated active learning (semi-FAL) framework to tackle the annotation and non-IID problems jointly. More specifically, the server node can provide (i) a pre-trained model to help each client node annotate the local data uniformly and (ii) an estimation of the global gradient to help correct the local gradient. The evaluation results demonstrate our semi-FAL framework can efficiently handle unlabeled online network data and achieves high accuracy and fast convergence.
Ergodicity and Related Bounds for One Particular Class of Markovian Time—Varying Queues with Heterogeneous Servers and Customer’s Impatience
Authors: Satin Yacov , Razumchik Rostislav , Kovalev Ivan , Zeifman Alexander
Published: April 2023

We consider a non-standard class of Markovian time: varying infinite capacity queues with possibly heterogeneous servers and impatience. We assume that during service time, a customer may switch to the faster server (with no delay), when such a server becomes available and no other customers are waiting. As a result, customers in the queue may become impatient and leave it. Under this setting and with certain restrictions on the intensity functions, the quantity of interest, the total number of customers in the system, is the level-dependent birth-and-death process (BPD). In this paper, for the first time in the literature, explicit upper bounds for the distance between two probability distributions of this BDP are obtained. Using the obtained ergodicity bounds in combination with the sensitivity bounds, we assess the stability of BDP under perturbations. Truncation bounds are also given, which allow for numerical solutions with guaranteed truncation errors. Finally, we provide numerical results to support the findings.
Mathematical Model Describing the Hardening and Failure Behaviour of Aluminium Alloys: Application in Metal Shear Cutting Process
Authors: Ben Said Lotfi , Chabchoub Alia Khanfir , Wali Mondher
Published: April 2023

Recent research has focused on sheet shear cutting operations. However, little research has been conducted on bar shear cutting. The main objective of the present investigation is to study bar shear cutting with numerical and experimental analysis. Bar shear cutting is an important operation because it precedes bulk metalworking processes for instance machining, extrusion and hot forging. In comparison to sheet shear cutting, bar shear cutting needs thermomechanical modelling. The variational formulation of the model is presented to predict damage mechanics in the bar shear cutting of aluminium alloys. Coupled thermomechanical modelling is required to analyse the mechanical behaviour of bulk workpieces, in which the combined effect of strain and temperature fields is considered in the shear cutting process. For this purpose, modified hardening and damage Johnson–Cook laws are developed. Numerical results for sheet and bar shear cutting operations are presented. The comparison between numerical and experimental results of shearing force/tool displacement during sheet and bar shear cutting operations proves that the use of a thermomechanical model in the case of the bar shear cutting process is crucial to accurately predict the mechanical behaviour of aluminium alloys. The analysis of the temperature field in the metal bar shows that the temperature can reach T = 388 °C on the sheared surface. The current model accurately predicts the shear cutting process and shows a strong correlation with experimental tests. Two values of clearance (c1 = 0.2 mm) and (c2 = 1.2 mm) are assumed for modeling the bar shear cutting operation. It is observed that for the low shear clearance, the burr is small, the quality of the sheared surface is better, and the fractured zone is negligible.
Simulation of Electromagnetic Forming Process and Optimization of Geometric Parameters of Perforated Al Sheet Using RSM
Authors: Satonkar Nilesh , Gopalan Venkatachalam
Published: April 2023

Electromagnetic forming (EMF) is a kind of high-speed forming technology that can be useful for materials like aluminum. EMF helps to overcome the limitations of traditional forming. Due to this ability, the use of EMF in automotive applications has risen in recent years. The application of finite element software packages such as ANSYS 22 gives numerical modelling capabilities to simulate the EMF process and to design the forming process. Hence, the aim of this research work is to build and study the three-dimensional finite element model for the electromagnetic forming process and analyze the geometric parameters influencing the deformation of the perforated sheet with a design of experiments (DOE) approach. The finite element simulation is used in two stages. In the first stage, the electromagnetic force or Lorentz force striking the workpiece (i.e., Al sheet) is predicted using the ANSYS 22 Emag module. In the second stage, the predicted Lorentz force is then applied on an Al sheet to calculate the sheet deformation. The deformation of the sheet is predicted for different combinations of the geometric parameters of the sheet, such as open area percentage, ligament ratio (LR) and size of the hole, using ANSYS 22 Structural. In the DOE, response surface methodology (RSM) is used by considering the geometric parameters of perforated sheet such as open area percentage, ligament ratio (LR) and size of the hole. To minimize the number of experiments, an RSM model named central composite design (CCD) is employed. Further, the optimization study finds that the maximum deformation 0.0435 mm is calculated for the optimized combination of 25% open area, 0.14 LR and 4 mm hole size.
Stock Price Prediction Using CNN-BiLSTM-Attention Model
Authors: Zhang Jilin , Ye Lishi , Lai Yongzeng
Published: April 2023

Accurate stock price prediction has an important role in stock investment. Because stock price data are characterized by high frequency, nonlinearity, and long memory, predicting stock prices precisely is challenging. Various forecasting methods have been proposed, from classical time series methods to machine-learning-based methods, such as random forest (RF), recurrent neural network (RNN), convolutional neural network (CNN), Long Short-Term Memory (LSTM) neural networks and their variants, etc. Each method can reach a certain level of accuracy but also has its limitations. In this paper, a CNN-BiLSTM-Attention-based model is proposed to boost the accuracy of predicting stock prices and indices. First, the temporal features of sequence data are extracted using a convolutional neural network (CNN) and bi-directional long and short-term memory (BiLSTM) network. Then, an attention mechanism is introduced to fit weight assignments to the information features automatically; and finally, the final prediction results are output through the dense layer. The proposed method was first used to predict the price of the Chinese stock index—the CSI300 index and was found to be more accurate than any of the other three methods—LSTM, CNN-LSTM, CNN-LSTM-Attention. In order to investigate whether the proposed model is robustly effective in predicting stock indices, three other stock indices in China and eight international stock indices were selected to test, and the robust effectiveness of the CNN-BiLSTM-Attention model in predicting stock prices was confirmed. Comparing this method with the LSTM, CNN-LSTM, and CNN-LSTM-Attention models, it is found that the accuracy of stock price prediction is highest using the CNN-BiLSTM-Attention model in almost all cases.
On ν-Level Interval of Fuzzy Set for Fractional Order Neutral Impulsive Stochastic Differential System
Authors: Shalini Manjitha Mani , Alessa Nazek , Kandasamy Banupriya , Loganathan Karuppusamy , Rangasamy Maheswari
Published: April 2023

The main concern of this paper is to investigate the existence and uniqueness of a fuzzy neutral impulsive stochastic differential system with Caputo fractional order driven by fuzzy Brownian motion using fuzzy numbers with bounded ν-level intervals that are convex, normal and upper-semicontinuous. Fuzzy Itô process, Grönwall’s inequality and the Banach fixed-point theorem are employed to probe the local and global existence. An analytical example is provided to examine the theoretical results.
TE-Polarized Electromagnetic Wave Diffraction by a Circular Slotted Cylinder
Authors: Abgaryan Garnik V. , Shestopalov Yury V.
Published: April 2023

The problem of diffraction of a TE-polarized electromagnetic wave by a circular slotted cylinder is investigated. The boundary value problem in question for the Helmholtz equation is reduced to an infinite system of linear algebraic equations of the second kind (SLAE-II) using integral summation identities (ISI). A detailed study of the matrix operator of the problem is performed and its Fredholm property in the weighted Hilbert space of infinite sequences is proven. The convergence of the truncation method constructed in the paper for the numerical solution of SLAE-II is justified and the results of computations are presented and discussed, specifically considering the determination of resonance modes.
Global Existence and Uniform Blow-Up to a Nonlocal Parabolic System with Nonlinear Boundary Conditions Arising in a Thermal Explosion Theory
Authors: Ma Wenyuan , Yan Baoqiang
Published: April 2023

This paper deals with a nonlinear nonlocal parabolic system with nonlinear heat-loss boundary conditions, which arise in the thermal explosion model. Firstly, we prove a comparison principle for some kinds of parabolic systems under nonlinear boundary conditions. Using this, we improve a new theorem of the sub-and-super solution. Secondly, based on the new sub-and-super solution theorem, the sufficient conditions that the solution exists and blows up uniformly in finite time are presented. Then, we generalize some of the lemmas related to uniform blow-up solutions, which are used to introduce the uniform blow-up profiles of solutions. Finally, we give several numerical simulations to illustrate the existence and uniform blow-up of solutions.
Adaptive Self-Organizing Map Using Optimal Control
Authors: Alkawaz Ali Najem , Kanesan Jeevan , Badruddin Irfan Anjum , Kamangar Sarfaraz , Hussien Mohamed , Ali Baig Maughal Ahmed , Ahammad N. Ameer
Published: April 2023

The self-organizing map (SOM), which is a type of artificial neural network (ANN), was formulated as an optimal control problem. Its objective function is to minimize the mean quantization error, and the state equation is the weight updating equation of SOM. Based on the objective function and the state equations, the Hamiltonian equation based on Pontryagin’s minimum principle (PMP) was formed. This study presents two models of SOM formulated as an optimal control problem. In the first model, called SOMOC1, the design is based on the state equation representing the weight updating equation of the best matching units of the SOM nodes in each iteration, whereas in the second model, called SOMOC2, it considers the weight updating equation of all the nodes in the SOM as the state updating equation. The learning rate is treated as the control variable. Based on the solution of the switching function, a bang-bang control was applied with a high and low learning rate. The proposed SOMOC2 model performs better than the SOMOC1 model and conventional SOM as it considers all the nodes in the Hamiltonian equation, and the switching function obtained from it is influenced by all the states, which provides one costate variable for each. The costate determines the marginal cost of violating the constraint by the state equations, and the switching function is influenced by this, hence producing a greater improvement in terms of the mean quantization error at the final iteration. It was found that the solution leads to an infinite order singular arc. The possible solutions for the suitable learning rates during the singular arc period are discussed in this study.
Ansatz and Averaging Methods for Modeling the (Un)Conserved Complex Duffing Oscillators
Authors: Alhejaili Weaam , Salas Alvaro H. , El-Tantawy Samir A.
Published: April 2023

In this study, both the ansatz and averaging methods are carried out for analyzing the complex Duffing oscillators including the undamped/conserved complex Duffing oscillator (CDO) and the damped/unconserved CDO to obtain some approximate analytical solutions. To analyze the conserved CDO, it is reduced to two decoupled conserved Duffing oscillators. After that, the exact solution of the conserved Duffing oscillator is employed to derive an approximation of the conserved CDO in terms of the Jacobi elliptic function. To analyze the damped CDO, two methodologies are considered. For the first methodology, the damped CDO is reduced to two decoupled damped Duffing oscillators, and the ansatz method is devoted to analyzing the damped Duffing oscillator. Accordingly, an approximation of the damped CDO in terms of trigonometric functions is obtained. In the second methodology, the averaging method is applied directly to the damped CDO to derive an approximation in terms of trigonometric functions. All the obtained solutions are compared with the fourth-order Runge–Kutta (RK4) numerical approximations. This study may help many researchers interested in the field of plasma physics to interpret their laboratory and observations results.
Attention-Based Residual Dilated Network for Traffic Accident Prediction
Authors: Zhang Ke , Guo Yaming
Published: April 2023

Traffic accidents directly influence public safety and economic development; thus, the prevention of traffic accidents is of great importance in urban transportation. The accurate prediction of traffic accidents can assist traffic departments to better control and prevent accidents. Thus, this paper proposes a deep learning method named attention-based residual dilated network (ARDN), to extract essential information from multi-source datasets and enhance accident prediction accuracy. The method utilizes bidirectional long short-term memory to model sequential information and incorporates an attention mechanism to recalibrate weights. Furthermore, a dilated residual layer is adopted to capture long term information effectively. Feature encoding is also employed to incorporate natural language descriptions and point-of-interest data. Experimental evaluations of datasets collected from Austin and Houston demonstrate that ARDN outperforms a range of machine learning methods, such as logistic regression, gradient boosting, Xgboost, and deep learning methods. The ablation experiments further confirm the indispensability of each component in the proposed method.
Genus Acanthella—A Wealthy Treasure: Secondary Metabolites, Synthesis, Biosynthesis, and Bioactivities
Authors: Ibrahim Sabrin R. M. , Ghazawi Kholoud F. , Miski Samar F. , ALsiyud Duaa Fahad , Mohamed Shaimaa G. A. , Mohamed Gamal A.
Published: April 2023

Marine sponges are multicellular and primitive animals that potentially represent a wealthy source of novel drugs. The genus Acanthella (family Axinellidae) is renowned to produce various metabolites with various structural characteristics and bioactivities, including nitrogen-containing terpenoids, alkaloids, and sterols. The current work provides an up-to-date literature survey and comprehensive insight into the reported metabolites from the members of this genus, as well as their sources, biosynthesis, syntheses, and biological activities whenever available. In the current work, 226 metabolites have been discussed based on published data from the period from 1974 to the beginning of 2023 with 90 references.
Marine Sulfated Polysaccharide PMGS Synergizes with Paclitaxel in Inhibiting Cervical Cancer In Vitro
Authors: Xia Xuan , Wang Yanhong , Shao Yingchun , Xu Jiazhen , Liang Bing , Liu Wenjing , Zeng Jun , Li Chunxia , Guan Huashi , Wang Shixin , Xing Dongming
Published: April 2023

The incidence and mortality of cervical cancer in female malignancies are second only to breast cancer, which brings a heavy health and economic toll worldwide. Paclitaxel (PTX)-based regimens are the first-class choice; however, severe side effects, poor therapeutic effects, and difficulty in effectively preventing tumor recurrence or metastasis are unavoidable. Therefore, it is necessary to explore effective therapeutic interventions for cervical cancer. Our previous studies have shown that PMGS, a marine sulfated polysaccharide, exhibits promising anti-human papillomavirus (anti-HPV) effects through multiple molecular mechanisms. In this article, a continuous study identified that PMGS, as a novel sensitizer, combined with PTX exerted synergistic anti-tumor effects on cervical cancer associated with HPV in vitro. Both PMGS and PTX inhibited the proliferation of cervical cancer cells, and the combination of PMGS with PTX displayed significant synergistic effects on Hela cells. Mechanistically, PMGS synergizes with PTX by enhancing cytotoxicity, inducing cell apoptosis and inhibiting cell migration in Hela cells. Collectively, the combination of PTX and PMGS potentially provides a novel therapeutic strategy for cervical cancer.
Optimization of Extraction of Phlorotannins from the Arctic Fucus vesiculosus Using Natural Deep Eutectic Solvents and Their HPLC Profiling with Tandem High-Resolution Mass Spectrometry
Authors: Obluchinskaya Ekaterina , Pozharitskaya Olga , Shevyrin Vadim , Kovaleva Elena , Flisyuk Elena , Shikov Alexander
Published: April 2023

Phlorotannins are secondary metabolites produced mainly by brown seaweeds (Phaeophyceae) and belong to the class of polyphenolic compounds with diverse bioactivities. The key factors in the extraction of polyphenols are the selection of a suitable solvent, method of extraction and selection of optimal conditions. Ultrasonic-assisted extraction (UAE) is one of the advanced energy-saving methods suitable for the extraction of labile compounds. Methanol, acetone, ethanol and ethyl acetate are the most commonly used solvents for polyphenol extraction. As alternatives to toxic organic solvents, a new class of green solvents, natural deep eutectic solvents (NADES), has been proposed for the efficient extraction of a wide range of natural compounds including polyphenols. Several NADES were screened previously for the extraction of phlorotannins; however, the extraction conditions were not optimized and chemical profiling of NADES extract was not performed. The purpose of this work was to study the effect of selected extraction parameters on the phlorotannin content in NADES extract from Fucus vesiculosus, optimization of extraction conditions and chemical profiling of phlorotannins in the NADES extract. A fast and green NADES-UAE procedure was developed for the extraction of phlorotannins. Optimization was performed through an experimental design and showed that NADES (lactic acid:choline chloride; 3:1) provides a high yield (137.3 mg phloroglucinol equivalents per g dry weight of algae) of phlorotannins under the following extraction conditions: extraction time 23 min, 30.0% water concentration and 1:12 sample to solvent ratio. The antioxidant activity of the optimized NADES extract was equal to that of EtOH extract. In total, 32 phlorotannins have been identified (one trimer, two tetramers, six pentamers, four hexamers, six heptamers, six octamers and seven nonamers) in NADES extracts from arctic F. vesiculosus using the HPLC-HRMS and MS/MS technique. It was noted that all the above-mentioned phlorotannins were identified in both EtOH and NADES extracts. Our results suggest that NADES could be considered as an alternative to the conventional techniques for the effective extraction of phlorotannins from F. vesiculosus with high antioxidant potential.
Radiologic Findings of Single Accessory Splenic Infarction in a Patient with Accessory Spleens in the Abdominal Cavity: A Case Report
Authors: Xu Nan , Xu Yingchen , Zhu Qiang
Published: April 2023

The presence of multiple accessory spleens in the abdominal cavity is typically limited to two, with cases involving a higher number being exceedingly rare. Concurrently, accessory spleen infarction is remarkably uncommon, primarily resulting from torsion of the vascular pedicle. In this report, we present a case of a 19-year-old male who experienced infarction in one of four accessory spleens. Imaging diagnosis proved challenging, with the definitive diagnosis being made through postoperative pathology, revealing no torsion in the affected accessory spleen. Following surgery combined with anti-inflammatory and analgesic treatment, the patient exhibited an uneventful recovery. No complications were observed at the 3-month follow-up. This case indicates the challenge and difficulty of diagnosing accessory splenic infarction without torsion in imaging diagnosis. Employing a multimodality approach and diffusion-weighted imaging may aid in confirming the diagnosis.
Efficacy of Silver Nanoparticles-Loaded Bone Cement against an MRSA Induced-Osteomyelitis in a Rat Model
Authors: Choi Young Suk , Kim Young Hwan , An Hye Min , Bae Sung Kyoung , Lee Young Koo
Published: April 2023

Background and Objectives: The purpose of this study was to assess the cytotoxicity and antibacterial effects of AgNP-impregnated Tetracalcium phosphate-dicalcium phosphate dihydrate (TTCP-DCPD). Materials and Methods: Using in vitro experiments, the cytotoxicity of AgNP-impregnated TTCP-DCPD against fibroblasts and osteocytes was assessed in terms of cell viability by water-soluble tetrazolium salt assay. To assess antibacterial effects, a disc diffusion test was used; osteomyelitis was induced first in vivo, by injection of methicillin-resistant Staphylococcus aureus into the tibia of rats. AgNP-impregnated TTCP-DCPD bone cement was then applied at various silver concentrations for 3 or 12 weeks. Antibacterial effects were assessed by culturing and reverse transcription-polymerase chain reaction (RT-PCR). For histological observation, the bone tissues were stained using hematoxylin and eosin. Results: Cell viability was decreased by the impregnated bone cement but did not differ according to AgNP concentration. The diameter of the growth-inhibited zone of MRSA was between 4.1 and 13.3 mm on the disks treated with AgNP, indicating antimicrobial effects. In vivo, the numbers of bacterial colonies were reduced in the 12-week treatment groups compared to the 3-week treatment groups. The groups treated with a higher (10×) dose of AgNP (G2–G5) showed a tendency of lower bacterial colony counts compared to the group without AgNP (G1). The PCR analysis results showed a tendency of decreased bacterial gene expression in the AgNP-impregnated TTCP-DCPD groups (G2–G5) compared to the group without AgNP (G1) at 3 and 12 weeks. In the H&E staining, the degree of inflammation and necrosis of the AgNP-impregnated TTCP-DCPD groups (G2–G5) showed a tendency to be lower at 3 and 12 weeks compared to the control group. Our results suggest that AgNP-impregnated TTCP-DCPD cement has antimicrobial effects. Conclusions: This study indicates that AgNP-impregnated TTCP-DCPD bone cement could be considered to treat osteomyelitis.
Current Concepts in the Diagnosis and Management of Adult Primary Immune Thrombocytopenia: Our Personal View
Authors: González-López Tomás José , Newland Adrian , Provan Drew
Published: April 2023

Primary immune thrombocytopenia (ITP) is an acquired blood disorder that causes a reduction in circulating platelets with the potential for bleeding. The incidence of ITP is slightly higher in adults and affects more women than men until 60 years, when males are more affected. Despite advances in basic science, primary ITP remains a diagnosis of exclusion. The disease is heterogeneous in its clinical behavior and response to treatment. This reflects the complex underlying pathophysiology, which remains ill-understood. Platelet destruction plays a role in thrombocytopenia, but underproduction is also a major contributing factor. Active ITP is a proinflammatory autoimmune disease involving abnormalities within the T and B regulatory cell compartments, along with several other immunological abnormalities. Over the last several years, there has been a shift from using immunosuppressive therapies for ITP towards approved treatments, such as thrombopoietin receptor agonists. The recent COVID-19 pandemic has hastened this management shift, with thrombopoietin receptor agonists becoming the predominant second-line treatment. A greater understanding of the underlying mechanisms has led to the development of several targeted therapies, some of which have been approved, with others still undergoing clinical development. Here we outline our view of the disease, including our opinion about the major diagnostic and therapeutic challenges. We also discuss our management of adult ITP and our placement of the various available therapies.
Spontaneous Improvement of Aortitis Associated with Severe COVID-19 Infection—A Case Report
Authors: Shimada Takashi , Itagaki Hideya , Shirota Yuko , Endo Tomoyuki
Published: April 2023

Aortitis is a rare complication of the coronavirus disease 2019 (COVID-19) and is often treated empirically with steroids. We present a case of spontaneous resolution of aortitis without treatment. A 65-year-old man was admitted to our intensive care unit for severe COVID-19 pneumonia and underwent rehabilitation in the general ward. On day 12, he developed fever, and on day 13, he developed right cervical pain and increased inflammatory markers. On day 16, a cervical echocardiogram showed vasculitis in the right common carotid artery, and on day 17, computed tomography (CT) of the neck showed thickening of the arterial wall of the right common to the internal carotid arteries. A retrospective assessment of the CT scan on day 12 showed wall thickening from the thoracic aorta to the abdominal aorta, and a diagnosis of aortitis was made. Autoantibody analysis, culture, and magnetic resonance imaging (MRI) of the head and neck showed no abnormalities. During the investigation of the cause of aortitis, the fever and inflammatory reaction spontaneously resolved and the right cervical pain gradually improved. Therefore, the patient was diagnosed with transient COVID-19-related aortitis. To our knowledge, this is the first report describing the spontaneous resolution of COVID-19-related aortitis.
Focal Segmental Glomerulosclerosis Followed by Acute Hepatitis A Infection: Case Report
Authors: An Min-Woo , Yoo Jeong-Ju , Kim Jin Kuk , Moon Ahrim , Kim Sang Gyune , Kim Young Seok
Published: April 2023

Background and Objectives: Chronic viral hepatitis such as hepatitis B or hepatitis C is frequently related to nephropathies, yet acute hepatitis A virus (HAV) infection is an exception. Materials and Methods: A 43-year-old male presented with jaundice accompanied by nausea and vomiting. The patient was diagnosed with acute HAV infection. Although the liver function improved after conservative treatment, various symptoms such as proteinuria, hypoalbuminemia, generalized edema and pleural effusion persisted. Due to nephrotic syndrome, the patient was referred to the clinic of the nephrology department and a renal biopsy was performed. Results: The result of the renal biopsy was focal segmental glomerulosclerosis (FSGS) based on histology, electron microscopy and immunohistochemistry. Therefore, based on the clinical history and biopsy results, the patient was diagnosed as having FSGS aggravated by acute HAV infection. Proteinuria, hypoalbuminemia and generalized edema were improved after prednisolone treatment. Conclusions: Although less common, acute HAV infection can also present with an extrahepatic manifestation, for example, FSGS. Hence, clinical attention is required if proteinuria or hypoalbuminemia persists in patients with acute HAV infection.
Quantitative Assessment of Interfacial Interactions Governing Ultrafiltration Membrane Fouling by the Mixture of Silica Nanoparticles (SiO2 NPs) and Natural Organic Matter (NOM): Effects of Solution Chemistry
Authors: Sun Yuqi , Zhang Runze , Sun Chunyi , Liu Zhipeng , Zhang Jian , Liang Shuang , Wang Xia
Published: April 2023

Mixtures of silica nanoparticles (SiO2 NPs) and natural organic matter (NOM) are ubiquitous in natural aquatic environments and pose risks to organisms. Ultrafiltration (UF) membranes can effectively remove SiO2 NP–NOM mixtures. However, the corresponding membrane fouling mechanisms, particularly under different solution conditions, have not yet been studied. In this work, the effect of solution chemistry on polyethersulfone (PES) UF membrane fouling caused by a SiO2 NP–NOM mixture was investigated at different pH levels, ionic strengths, and calcium concentrations. The corresponding membrane fouling mechanisms, i.e., Lifshitz–van der Waals (LW), electrostatic (EL), and acid–base (AB) interactions, were quantitatively evaluated using the extended Derjaguin–Landau–Verwey–Overbeek (xDLVO) theory. It was found that the extent of membrane fouling increased with decreasing pH, increasing ionic strength, and increasing calcium concentration. The attractive AB interaction between the clean/fouled membrane and foulant was the major fouling mechanism in both the initial adhesion and later cohesion stages, while the attractive LW and repulsive EL interactions were less important. The change of fouling potential with solution chemistry was negatively correlated with the calculated interaction energy, indicating that the UF membrane fouling behavior under different solution conditions can be effectively explained and predicted using the xDLVO theory.
Modulation of the Dipole Potential of Model Lipid Membranes with Phytochemicals: Molecular Mechanisms, Structure–Activity Relationships, and Implications in Reconstituted Ion Channels
Authors: Efimova Svetlana S. , Ostroumova Olga S.
Published: April 2023

Phytochemicals, such as flavonoids, stilbenoids, alkaloids, terpenoids, and related compounds, have a wide range of useful pharmacological properties which cannot be ascribed to binding to a single peptide or protein target alone. Due to the relatively high lipophilicity of phytochemicals, the lipid membrane is thought to mediate their effects via changes in the properties of the lipid matrix, in particular, by modulating the transmembrane distribution of the electrical potential and, consequently, the formation and functioning of the ion channels reconstituted in the lipid bilayers. Therefore, biophysical studies on the interactions between plant metabolites and model lipid membranes are still of interest. This review represents an attempt to provide a critical analysis of a variety of studies on altering membranes and ion channels with phytochemicals via disturbing the potential drop at the membrane–aqueous solution interface. Critical structural motifs and functioning groups in the molecules of plant polyphenols (alkaloids and saponins are identified) and the possible mechanisms of dipole potential modulation with phytochemicals are discussed.
Selective Separation of Singly Charged Chloride and Dihydrogen Phosphate Anions by Electrobaromembrane Method with Nanoporous Membranes
Authors: Butylskii Dmitrii , Troitskiy Vasiliy , Chuprynina Daria , Kharchenko Ivan , Ryzhkov Ilya , Apel Pavel , Pismenskaya Natalia , Nikonenko Victor
Published: April 2023

The entrance of even a small amount of phosphorus compounds into natural waters leads to global problems that require the use of modern purification technologies. This paper presents the results of testing a hybrid electrobaromembrane (EBM) method for the selective separation of Cl− (always present in phosphorus-containing waters) and H2PO4− anions. Separated ions of the same charge sign move in an electric field through the pores of a nanoporous membrane to the corresponding electrode, while a commensurate counter-convective flow in the pores is created by a pressure drop across the membrane. It has been shown that EBM technology provides high fluxes of ions being separated across the membrane as well as a high selectivity coefficient compared to other membrane methods. During the processing of solution containing 0.05 M NaCl and 0.05 M NaH2PO4, the flux of phosphates through a track-etched membrane can reach 0.29 mol/(m2×h). Another possibility for separation is the EBM extraction of chlorides from the solution. Its flux can reach 0.40 mol/(m2×h) through the track-etched membrane and 0.33 mol/(m2×h) through a porous aluminum membrane. The separation efficiency can be very high by using both the porous anodic alumina membrane with positive fixed charges and the track-etched membrane with negative fixed charges due to the possibility of directing the fluxes of separated ions in opposite sides.
Fabrication, Experimental Investigation and Prediction of Wear Behavior of Open-Cell AlSi10Mg-SiC Composite Materials
Authors: Kolev Mihail , Drenchev Ludmil , Petkov Veselin
Published: April 2023

This research investigates the tribological behavior of advanced open-cell porous AlSi10Mg-SiC composites fabricated using the novel replication method of NaCl space holders. These composite materials have potential applications in lightweight and high-strength structures that require high resistance to friction and wear. The composites were tested using a pin-on-disk method under dry sliding-friction conditions at ambient temperature, with a sliding velocity of 1.0 m∙s−1 and an applied load of 50 N. The resulting wear parameters, including the coefficient of friction (COF) and mass wear, provided quantitative measures of the tribological behavior. Microstructural observations of the worn composite surfaces were carried out using scanning-electron microscopy (SEM) to study the wear mechanisms, and an elemental analysis was performed using X-ray energy-dispersive spectroscopy (EDS) to examine the elemental composition. The results showed that the AlSi10Mg-SiC composites had lower mass wear and COF than the open-cell porous AlSi10Mg material under the same experimental conditions. Three different machine learning (ML) models were employed to predict the COF of the composites, and their performances were evaluated using the R2, MSE, RMSE, and MAE metrics on the validation and test sets.
Strain-Induced Phase Transformation Modeling of QP980 Steel and Its Application to Complex Loading Paths
Authors: Lv Zhiqin , Dai Enkai , Guo Ning , Yuan Panpan , Liu Guoqiang , Tang Bingtao
Published: April 2023

Quenching and partitioning (QP) steel has attracted much focus due to the effect of phase transformation induced plasticity (TRIP). However, the TRIP behavior makes it difficult to accurately predict the strain and stress distribution as well as the phase transformation behavior of QP steel. Scanning electron microscope (SEM) images of the QP980 microstructure were produced in this study, characterized by a combination of lath martensite, polygonal ferrite and retained austenite. The volume fraction evolution of retained austenite with equivalent plastic strain (EPS) of uniaxial tension was obtained by electron-backscatter diffraction. The phase transformation kinetics equations of QP980 were deduced based on the phase transformation model proposed by Olson and Cohen (simplified as O-C theory), considering the effects of strain rate, deformation temperature and stress state. A constitutive model on the dependence of the phase transformation was proposed to reveal the relation between metallographic characteristics and mechanical performance of QP980 steel during deformation. The User subroutine VUMAT in ABAQUS/Explicit was implemented to describe the volume fraction of retained austenite (VFRA) under different stress states. The established phase transformation and constitutive model were applied to three kinds of complex path loading tests. The variation in the retained austenite under complex strain paths was obtained and compared with the experimental results.
Influence of Cholesterol on the Regulation of Osteoblast Function
Authors: Akhmetshina Alena , Kratky Dagmar , Rendina-Ruedy Elizabeth
Published: April 2023

Bone is a dynamic tissue composed of cells, an extracellular matrix, and mineralized portion. Osteoblasts are responsible for proper bone formation and remodeling, and function. These processes are endergonic and require cellular energy in the form of adenosine triphosphate (ATP), which is derived from various sources such as glucose, fatty acids, and amino acids. However, other lipids such as cholesterol have also been found to play a critical role in bone homeostasis and can also contribute to the overall bioenergetic capacity of osteoblasts. In addition, several epidemiological studies have found a link between elevated cholesterol, cardiovascular disease, an enhanced risk of osteoporosis, and increased bone metastasis in cancer patients. This review focuses on how cholesterol, its derivatives, and cholesterol-lowering medications (statins) regulate osteoblast function and bone formation. It also highlights the molecular mechanisms underlying the cholesterol–osteoblast crosstalk.
Wafer Surface Defect Detection Based on Background Subtraction and Faster R-CNN
Authors: Zheng Jiebing , Zhang Tao
Published: April 2023

Concerning the problem that wafer surface defects are easily confused with the background and are difficult to detect, a new detection method for wafer surface defects based on background subtraction and Faster R-CNN is proposed. First, an improved spectral analysis method is proposed to measure the period of the image, and the substructure image can then be obtained on the basis of the period. Then, a local template matching method is adopted to position the substructure image, thereby reconstructing the background image. Then, the interference of the background can be eliminated by an image difference operation. Finally, the difference image is input into an improved Faster R-CNN network for detection. The proposed method has been validated on a self-developed wafer dataset and compared with other detectors. The experimental results show that compared with the original Faster R-CNN, the proposed method increases the mAP effectively by 5.2%, which can meet the requirements of intelligent manufacturing and high detection accuracy.
Silver Nanocoating of LiNi0.8Co0.1Mn0.1O2 Cathode Material for Lithium-Ion Batteries
Authors: Li Xintong , Chang Kai , Abbas Somia M. , El-Tawil Rasha S. , Abdel-Ghany Ashraf E. , Hashem Ahmed M. , Wang Hua , Coughlin Amanda L. , Zhang Shixiong , Mauger Alain , Zhu Likun , Julien Christian M.
Published: April 2023

Surface coating has become an effective approach to improve the electrochemical performance of Ni-rich cathode materials. In this study, we investigated the nature of an Ag coating layer and its effect on electrochemical properties of the LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode material, which was synthesized using 3 mol.% of silver nanoparticles by a facile, cost-effective, scalable and convenient method. We conducted structural analyses using X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy, which revealed that the Ag nanoparticle coating did not affect the layered structure of NCM811. The Ag-coated sample had less cation mixing compared to the pristine NMC811, which could be attributed to the surface protection of Ag coating from air contamination. The Ag-coated NCM811 exhibited better kinetics than the pristine one, which is attributed to the higher electronic conductivity and better layered structure provided by the Ag nanoparticle coating. The Ag-coated NCM811 delivered a discharge capacity of 185 mAh·g−1 at the first cycle and 120 mAh·g−1 at the 100th cycle, respectively, which is better than the pristine NMC811.
A Thermopile-Based Gas Flow Sensor with High Sensitivity for Noninvasive Respiration Monitoring
Authors: Liu Zemin , Zhang Chenchen , Ding Xuefeng , Ni Yue , Zhou Na , Wang Yanhong , Mao Haiyang
Published: April 2023

In this work, a N/P polySi thermopile-based gas flow device is presented, in which a microheater distributed in a comb-shaped structure is embedded around hot junctions of thermocouples. The unique design of the thermopile and the microheater effectively enhances performance of the gas flow sensor leading to a high sensitivity (around 6.6 μV/(sccm)/mW, without amplification), fast response (around 35 ms), high accuracy (around 0.95%), and mood long-term stability. In addition, the sensor has the advantages of easy production and compact size. With such characteristics, the sensor is further used in real-time respiration monitoring. It allows detailed and convenient collection of respiration rhythm waveform with sufficient resolution. Information such as respiration periods and amplitudes can be further extracted to predict and alert of potential apnea and other abnormal status. It is expected that such a novel sensor could provide a new approach for respiration monitoring related noninvasive healthcare systems in the future.
Highly Active Nanocrystalline ZnO and Its Photo-Oxidative Properties towards Acetone Vapor
Authors: Chizhov Artem , Kutukov Pavel , Gulin Alexander , Astafiev Artyom , Rumyantseva Marina
Published: April 2023

Zinc oxide is one of the well-known photocatalysts, the potential applications of which are of great importance in photoactivated gas sensing, water and air purification, photocatalytic synthesis, among others. However, the photocatalytic performance of ZnO strongly depends on its morphology, composition of impurities, defect structure, and other parameters. In this paper, we present a route for the synthesis of highly active nanocrystalline ZnO using commercial ZnO micropowder and ammonium bicarbonate as starting precursors in aqueous solutions under mild conditions. As an intermediate product, hydrozincite is formed with a unique morphology of nanoplates with a thickness of about 14–15 nm, the thermal decomposition of which leads to the formation of uniform ZnO nanocrystals with an average size of 10–16 nm. The synthesized highly active ZnO powder has a mesoporous structure with a BET surface area of 79.5 ± 4.0 m2/g, an average pore size of 20 ± 2 nm, and a cumulative pore volume of 0.507 ± 0.051 cm3/g. The defect-related PL of the synthesized ZnO is represented by a broad band with a maximum at 575 nm. The crystal structure, Raman spectra, morphology, atomic charge state, and optical and photoluminescence properties of the synthesized compounds are also discussed. The photo-oxidation of acetone vapor over ZnO is studied by in situ mass spectrometry at room temperature and UV irradiation (λmax = 365 nm). The main products of the acetone photo-oxidation reaction, water and carbon dioxide, are detected by mass spectrometry, and the kinetics of their release under irradiation are studied. The effect of morphology and microstructure on the photo-oxidative activity of ZnO samples is demonstrated.
PZT Composite Film Preparation and Characterization Using a Method of Sol-Gel and Electrohydrodynamic Jet Printing
Authors: Cui Yan , Yu Hao , Abbas Zeshan , Wang Zixiang , Wang Lunxiang , Wang Dazhi
Published: April 2023

Lead zircon titanate (PZT) composite films were advantageously prepared by a novel hybrid method of sol-gel and electrohydrodynamic jet (E-jet) printing. PZT thin films with thicknesses of 362 nm, 725 nm and 1092 nm were prepared on Ti/Pt bottom electrode via Sol-gel method, and then the PZT thick films were printed on the base of the PZT thin films via E-jet printing to form PZT composite films. The physical structure and electrical properties of the PZT composite films were characterized. The experimental results showed that, compared with PZT thick films prepared via single E-jet printing method, PZT composite films had fewer micro-pore defects. Moreover, the better bonding with upper and lower electrodes and higher preferred orientation of crystals were examined. The piezoelectric properties, dielectric properties and leakage currents of the PZT composite films were obviously improved. The maximum piezoelectric constant of the PZT composite film with a thickness of 725 nm was 69.4 pC/N, the maximum relative dielectric constant was 827 and the leakage current was reduced to 1.5 × 10−6A at a test voltage of 200V. This hybrid method can be widely useful to print PZT composite films for the application of micro-nano devices.
The Effect of Rickettsia bellii on Anaplasma marginale Infection in Dermacentor andersoni Cell Culture
Authors: Aspinwall Joseph A. , Jarvis Shelby M. , Noh Susan M. , Brayton Kelly A.
Published: April 2023

Anaplasma marginale is a tick-borne pathogen that causes bovine anaplasmosis, which affects cattle around the world. Despite its broad prevalence and severe economic impacts, limited treatments exist for this disease. Our lab previously reported that a high proportion of Rickettsia bellii, a tick endosymbiont, in the microbiome of a population of Dermacentor andersoni ticks negatively impacts the ticks’ ability to acquire A. marginale. To better understand this correlation, we used mixed infection of A. marginale and R. bellii in D. andersoni cell culture. We assessed the impacts of different amounts of R. bellii in coinfections, as well as established R. bellii infection, on the ability of A. marginale to establish an infection and grow in D. andersoni cells. From these experiments, we conclude that A. marginale is less able to establish an infection in the presence of R. bellii and that an established R. bellii infection inhibits A. marginale replication. This interaction highlights the importance of the microbiome in preventing tick vector competence and may lead to the development of a biological or mechanistic control for A. marginale transmission by the tick.
Hepatitis B Virus Genotype D: An Overview of Molecular Epidemiology, Evolutionary History, and Clinical Characteristics
Authors: Sant’Anna Thaís B. , Araujo Natalia M.
Published: April 2023

The hepatitis B virus (HBV) genotype D (HBV/D) is the most extensively distributed genotype worldwide with distinct molecular and epidemiological features. This report provides an up-to-date review on the history of HBV/D subgenotyping and misclassifications, along with large-scale analysis of over 1000 HBV/D complete genome sequences, with the aim of gaining a thorough understanding of the global prevalence and geographic distribution of HBV/D subgenotypes. We have additionally explored recent paleogenomic findings, which facilitated the detection of HBV/D genomes dating back to the late Iron Age and provided new perspectives on the origins of modern HBV/D strains. Finally, reports on distinct disease outcomes and responses to antiviral therapy among HBV/D subgenotypes are discussed, further highlighting the complexity of this genotype and the importance of HBV subgenotyping in the management and treatment of hepatitis B.