bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Turning Polytetrafluoroethylene External Cylindrical Groove with Curvilinear Profile Tool
Authors: Ni Jing , Lou Bokai , Cui Zhi , He Lihua , Zhu Zefei
Published: January 2023

Polytetrafluoroethylene (PTFE) is extensively used in equipment used for manufacturing semiconductor components and wet etching equipment. However, achieving ideal dimensional accuracy when cutting PTFE is challenging. In this study, we performed cutting experiments using a curvilinear tool and analyzed cutting force, cutting temperature, groove width, and surface roughness in PTFE grooving. The results indicated that the cutting force was most notably affected by the feed rate in Stage I of grooving. The rate of change in cutting force was the largest in Stage II because of the increase in the tool contact area. In Stage III, the shear area of the rake face was the largest, and the cutting force tended to be stable. The groove width was measured with a minimum error rate of 0.95% at a feed rate of 0.05 mm/rev. Moreover, the groove exhibited a time—independent springback. The minimum groove surface roughness was 0.586 at a feed rate of 0.05 mm/rev. The ideal feed rate was 0.05 mm/rev with groove width, surface quality, and chip curl as the key parameters. The processing parameters obtained in this study can be applied to actual production for the optimization of manufacturing accuracy.
Fabrication and Characteristics of a Conductive FeCo@Au Nanowire Alloy for Semiconductor Test Socket Connectors
Authors: Kim In Yea , Kim Jong Won , Lee Byeung Ju , Lim Jae-Hong
Published: January 2023

The most promising approach for improving the electrical performance of connectors used in semiconductor test sockets involves increasing their electrical conductivity by incorporating one-dimensional (1D) conductive materials between zero-dimensional (0D) conductive materials. In this study, FeCo nanowires were synthesized by electroplating to prepare a material in which 1D materials could be magnetically aligned. Moreover, the nanowires were coated with highly conductive Au. The magnetization per unit mass of the synthesized FeCo and FeCo@Au nanowires was 167.2 and 13.9 emu/g, respectively. The electrical performance of rubber-based semiconductor connectors before and after the introduction of synthetic nanowires was compared, and it was found that the resistance decreased by 14%. The findings reported herein can be exploited to improve the conductivity of rubber-type semiconductor connectors, thereby facilitating the development of connectors using 0D and 1D materials.
Percentage Ratios of Cutting Forces during High-Reed Face Milling
Authors: Reznicek Martin , Horava Cyril , Ovsik Martin
Published: January 2023

This research paper is concerned with the experimental study of high-feed end milling of 1.4541 (X6CrNiTi18-10) stainless steel with replaceable cermet plates. Several machining operations were performed under different cutting conditions. The variable values were depth of cut, feed per tooth and cutting speed. The results were analyzed, and cutting forces were evaluated for dependence on cutting conditions (cutting speed, depth of cut, feed per tooth). The obtained data were statistically processed and plotted in graphs. It was found that the percentage distribution of cutting forces changed as the tool load increased. The ratio of forces acting in individual axes also changed with varying trends. An increasing trend was recorded in the x and y axes, while a decreasing trend was recorded in the z axis. Measured change, approximately 10%, can no longer be neglected as it can significantly influence the clamping stability of a part.
Natural Cellulose from Ziziphus jujuba Fibers: Extraction and Characterization
Authors: Amior Aicha , Satha Hamid , Laoutid Fouad , Toncheva Antoniya , Dubois Philippe
Published: January 2023

Nowadays, due to their natural availability, renewability, biodegradability, nontoxicity, light weight and relatively low cost, natural fibers, especially lignocellulosic fibers, present attractive potential to substitute non-eco-friendly synthetic fibers. In this study, Ziziphus jujuba fibers were used, thanks to their low lignin content, as an alternative of renewable resource for the production of cellulosic fibers with suitable characteristics and minimal time and energy consumption. In fact, due to their valuable chemical composition, it was possible to remove the amorphous fractions and impurities from the fiber surface by applying ultrasounds coupled with alkaline treatment (80 °C, 5 wt.% NaOH), followed by a bleaching step. The efficient dissolution of the noncellulosic compounds was confirmed by Fourier Transform Infrared Spectroscopy (FTIR). The resulted increase in the crystallinity index (from 35.7% to 57.5%), occurred without impacting the crystalline structure of the fibers. The morphological analysis of the fibers evidences the higher surface area of the obtained fibers. Based on the obtained results, Ziziphus jujuba fibers were found to present a suitable sustainable source for the production of cellulosic fibers.
Acetabular Implant Finite Element Simulation with Customised Estimate of Bone Properties
Authors: Soloviev Dmitriy , Maslov Leonid , Zhmaylo Mikhail
Published: January 2023

The goal of the study is to analyse the strength and stability of a system comprising the pelvis and a customised implant under functional loads using the finite element method. We considered a technique for assessing the elastic properties of bone tissue via computer tomography, constructing finite element models of pelvic bones and a customised endoprosthesis based on the initial geometric models obtained from the National Medical Research Centre for Oncology n.a. N.N. Blokhin (Moscow, Russia). A series of calculations were carried out for the stress-strain state of the biomechanical system during walking, as well as at maximum loads when ascending and descending stairs. The analysis provided conclusions about the strength and stability of the studied device.
A Non-Thinning Forming Method with Improvement of Material Properties
Authors: Guo Yankuo , Shi Yongjun , Guo Feng
Published: January 2023

Thickness thinning is one of the processing defects that tend to occur in traditional stamping or mechanical bending of the plate and tube. In the field of high mechanical performance requirements (such as pressure vessels), the thinning phenomenon cannot be ignored. Thermal stress forming has excellent characteristics of forming without thinning, but the forming angle of this method is small, thus limiting the promotion and application of the process in the field of the form. To solve the problem, thermal stress forming with the baffle pressure method (BPM) is proposed. The coupled thermodynamic model of BPM is established, and the bending angle and deformation mechanism of the BPM are investigated. Lastly, the grain size and microhardness are measured and discussed. Results of the bending angle show that the proposed method can increase the bending angle by 57.71 times compared with the traditional method. The bending angle of BPM is determined by both the thermal buckling and the baffle, and the baffle plays a major role. The results of grain size and microhardness analysis show that the method refines the grain size, increases the material microhardness by 1.31 times and thickens the deformation zone by about 2.75%. In addition, the analytical equation of beam bending with laser as the heat source is given in this paper; this has some significance for further enrichment and development of the basic theory of beam thermoplastic bending.
Composition-Related Dielectric, Ferroelectric and Electrocaloric Properties of Pb5Ge3O11 Single Crystals Modified by Ba Ions
Authors: Krupska-Klimczak Magdalena , Jankowska-Sumara Irena , Gwizd Przemysław , Koralewski Marceli , Soszyński Andrzej
Published: January 2023

In this paper, we studied some ferroelectric properties of archetypal oxide uniaxial ferroelectric single crystals of Pb5Ge3O11 modified by Ba ions. They include dielectric, DSC, ferroelectric polarization, and electrocaloric effect (ECE) measurements. The measurements show that increasing Ba doping considerably influences all the measured parameters, mainly by lowering the Curie temperature, gradually diffusing the phase transition, and decreasing values of polarization as well as the coercive field. The decrease in overall ECE is influenced by decreasing polarization. Compared with the pure PGO single crystals, this decrease is from 1.2 K to 0.2 K. However, the effect of diffusing the phase transition increases the range of its occurrence (up to 30 K), which might be beneficial in applications.
Optimization of the Bionic Wing Shape of Tidal Turbines Using Multi-Island Genetic Algorithm
Authors: Zhang Zhiyang , Wu Bo , Wu Linyan , Liu Weixing , Liu Lei , Li Ningyu , Cui Lin
Published: January 2023

In this study, we improved the energy acquisition efficiency of tidal turbines with bionic airfoils by optimizing the seagull, long-eared owl, sparrowhawk, and two-dimensional airfoils, thereby obtaining a better lift–drag ratio. We used Isight software to integrate the Integrated Computer Engineering and Manufacturing (ICEM) software and used Fluent simulation software, batch operation file, and multi-island genetic algorithm to maximize the lift–drag ratio as the objective function for optimizing the original airfoil. The optimized upper airfoil profile was distributed upward from the starter wing, and the thickness of the upper wing was the greatest. Meanwhile, the lower airfoil profile was thinner and more curved. The thickness of the three airfoils was distributed backward from the front of the wing, with the maximum thickness at the front, and the maximum camber was distributed backward from the front. The three optimized wings exhibited a maximum lift–drag ratio at an angle of attack of approximately 5°, with the sparrowhawk wing having a maximum lift–drag ratio of 80.87 at an angle of attack of 6°, the seagull wing having a maximum lift–drag ratio of 76.82 at an angle of attack of 4°, and the long-eared owl wing having a maximum lift–drag ratio of 68.43 at an angle of attack of 5°.
6-Dimensional Virtual Human-Machine Interaction Force Estimation Algorithm in Astronaut Virtual Training
Authors: Lin Lingjie , Wang Lan , Chang Ying , Zhang Lixun , Xue Feng
Published: January 2023

It is necessary to conduct virtual training for astronauts on the ground to improve the efficiency and safety of astronauts carrying objects in space. Cooperation between the two astronauts is required when handling massive objects. During this process, it is necessary to obtain the operating force of each astronaut. The research purpose of this paper was to propose an algorithm to map the astronaut’s operation on the VR handle to the human–machine interaction force without the robot’s participation, thereby saving costs. In this paper, a virtual robot simulation model is established, while the controller is designed based on the inverse system method. The virtual human–machine interaction force was obtained based on the inverse dynamics method. The influence of different parameters on the final position of the virtual object was analyzed. The physical engine was integrated into the virtual force sensor to ensure that the human–machine interaction forces of multiple astronauts can be coupled. The results showed that the virtual human–machine interaction force is similar to the real one and has a low output noise (approximately 5.5 N). This force can be applied to astronaut collaborative virtual training.
A Novel Method for LCD Module Alignment and Particle Detection in Anisotropic Conductive Film Bonding
Authors: Li Tengyang , Zhang Feng , Yang Huabin , Luo Huiyuan , Zhang Zhengtao
Published: January 2023

In this paper, we propose a misalignment correct method and a particle detection algorithm to improve the accuracy in the quality inspection of the LCD module after the anisotropic conductive film (ACF) bonding. We use only one camera to acquire images of multiple positions in order to establish the transformation from the image space to the world coordinate. Our method can accurately determine the center of rotation of the carrier table and calculate the deviation of position and angle of the tested module. Compared to traditional ways that rely on multiple cameras to align the large-sized product, our method has the advantages of simple structure, low cost, and fast calibration process. The particle detection is performed after positioning all bumps of the bonded module. The gray morphology-based algorithm is developed to detect the extreme point of every particle and refine the particle result through blob analysis. This method reduces the over-checking rate and performs better on the detection precision for dense particles. We verify the effectiveness of our proposed methods in our experiments. The alignment error can be less than 0.05 mm, and the accuracy of the particle detection is 93% while the recall rate is 92.4%.
Investigating the Flow Characteristics of Superhydrophobic U-Shaped Microchannels
Authors: Tao Zhi , Fang Weidong , Li Haiwang , Xu Tiantong , Huang Yi , Wu Hanxiao , Li Murun
Published: January 2023

Hydrophobicity has been widely reported for its superior behavior in drag reduction, self-cleaning, and anti-corrosion in many areas. Especially in engineering design, the research of the unique property of the slip flow with complex flow patterns is essential for practical applications. In this paper, the flow characteristics of a superhydrophobic U-shaped microchannel are systematically investigated, as the curved part is a fundamental component in microfluids. A slip model is established based on theoretical and experimental solutions. Various types of U-shaped microchannels, radii of curvature, and contact angles are studied with a wide range of Reynolds numbers from 0 to 300. We propose a velocity distribution to examine the non-uniformity of slip velocity on the cross-section. This imbalance is improved with an increase in the apparent contact angle and flow rate, and a decrease in the radius of curvature. The secondary flow and vortices generated by the centrifugal force are enhanced, and their positions are changed due to the slippery boundary. The results show a considerable drag reduction from 10% to 40% with different contact angles. The variation of curvature does not have a decisive impact on the final performance when the surface wettability maintains a steady state. Our research elucidates the physical principle of the slip model in curved channels, showing extensive applications of hydrophobicity in the design of complex microchips and the optimization strategy of heat transfer systems.
Magnetic Nanocomposites and Imprinted Polymers for Biomedical Applications of Nucleic Acids
Authors: Popova Victoriya , Dmitrienko Elena , Chubarov Alexey
Published: January 2023

Magnetic nanocomposites (MNCs) combine the features of magnetic nanoparticles and a second material, which provide distinct physical, chemical, and biological properties. The magnetic core for nanocomposite synthesis is extensively used due to its high saturation magnetization, chemical stability, large surface area, and easy functionalization. Moreover, magnetic nanoparticles (MNPs) have great potential for magnetic resonance imaging (MRI), magnetic particle imaging (MPI), hyperthermia, and targeted drug and gene delivery by an external magnetic field. Numerous composing units exist, which leads to the outstanding application of composites. This review focuses on nucleic acid-based bioapplications of MNCs with polymeric, organic, inorganic, biomolecules, and bioinspared surface coating. In addition, different forms, such as core–shell, doping, multilayer, yolk–shell, and Janus-shaped hybrids, are discussed, and their unique properties are highlighted. The unique types of nanocomposites as magnetic molecularly imprinted polymer (MMIP) properties are presented. This review presents only the synthesis of MNCs using ready-made magnetic cores. These restrictions are associated with many materials, the quantitative and qualitative magnetic core composition, and synthesis procedures. This review aims to discuss the features of nucleic acid-based MNC information available to researchers in this field and guide them through some problems in the area, structure variation, and surface functionalization possibilities. The most recent advancements of MNCs and imprinted polymers in nucleic acid-based therapy, diagnostics, theranostics, magnetic separation, biocatalytic, and biosensing are introduced.
Interrelation between the Solid-State Synthesis Conditions and Magnetic Properties of the NiCr2O4 Spinel
Authors: Cherosov Mikhail , Batulin Ruslan , Kiiamov Airat , Rogov Alexey , Vakhitov Iskander , Gabadullin Damir , Tayurskii Dmitrii , Yusupov Roman
Published: January 2023

The synthesis of the NiCr2O4 compound with the spinel structure via the high-temperature solid-state reaction leads to different deviations of the cationic composition from the nominal depending on the atmosphere in the furnace chamber. The samples prepared from the same starting NiO and Cr2O3 compounds but in different atmospheres differ in phase composition and orbital and spin ordering temperatures. We find that a common route of synthesis in the air and a possible presence of the Ni2O3 in initial NiO lead to the incorporation of the Ni3+ ions into the octahedral sites regularly occupied by the Cr3+ ions. This results in a decrease in the orbital ordering and an increase in the Nèel temperatures. We propose that the Nèel temperature value serves as a measure of a departure of a composition from the nominal NiCr2O4. The lowest Nèel temperature among our series was TN = 63 K which we consider the closest to the intrinsic quantity of the NiCr2O4 compound.
Magnetic-Moment-Induced Metal–Insulator Transition in ThMnXN (X = As, P): A First Principles Study
Authors: Sen Smritijit , Ghosh Haranath
Published: January 2023

In this work, we show magnetic-moment-induced metal–insulator transitions in ThMnXN (X = As, P) and elucidate some of the experimentally observed results obtained by Zhang et al. through a first principles density functional study. Our calculations revealed that the magnetic ground states of ThMnXN (X = As, P) are C-type anti-ferromagnets with a small energy gap (∼0.4 eV) at the Fermi level, which is in good agreement with the experiments. Our constraint moment calculations revealed local magnetic moments of 3.42 μB and 3.63 μB in Mn atoms for ThMnAsN and ThMnPN, respectively, which are consistent with the experimentally measured local magnetic moment for Mn atoms. An effective Hubbard U = (U − J) of 0.9 eV was applied within the GGA+U formalism in ThMnPN to reproduce the experimental Mn moment. We also found that, as the Mn moments decrease in ThMnXN (X = As, P), the energy gaps also decrease and finally disappear at Mn moment 2.7 μB for ThMnAsN and 2.8 μB for ThMnPN. Therefore, our results stipulate a possible metal–insulator transition in ThMnXN (X = As, P) induced by the Mn local moment.
Slow Magnetic Relaxation in Cobalt(II) Complexes with One-Dimensional Hydrogen-Bonded Networks
Authors: Mitsuhashi Ryoji , Sakiyama Hiroshi , Hayashi Yoshihito
Published: January 2023

Two new cobalt(II) complexes with an unsymmetrical bidentate ligand, 2-(1,4,5,6-tetrahydropyrimidin-2-yl)-6-methoxyphenol (H2mthp), were synthesized and crystallographically characterized. Tetra- and hexa-coordinate mononuclear complexes were selectively obtained by adjusting the stoichiometry of the base. The coordination geometry of hexa-coordinated complex was severely distorted from an ideal octahedron, due to the NO5 coordination environment from the mixed coordination of one Hmthp− and two H2mthp ligands. Both complexes formed one-dimensional chain networks by hydrogen-bond and N-H···π interactions. Single-molecule magnet behavior was observed for the tetrahedral complex under zero magnetic field. The relatively short Co···Co distances induced non-zero intermolecular magnetic coupling, which split the ground ±Ms levels to suppress quantum-tunneling of magnetization. In the octahedral complex, by contrast, the distance was not short enough to induce the coupling. As a consequence, single-molecule magnetic behavior was observed for the octahedral complex only in the presence of an external static field.
A Novel Neighborhood Granular Meanshift Clustering Algorithm
Authors: Chen Qiangqiang , He Linjie , Diao Yanan , Zhang Kunbin , Zhao Guoru , Chen Yumin
Published: January 2023

The most popular algorithms used in unsupervised learning are clustering algorithms. Clustering algorithms are used to group samples into a number of classes or clusters based on the distances of the given sample features. Therefore, how to define the distance between samples is important for the clustering algorithm. Traditional clustering algorithms are generally based on the Mahalanobis distance and Minkowski distance, which have difficulty dealing with set-based data and uncertain nonlinear data. To solve this problem, we propose the granular vectors relative distance and granular vectors absolute distance based on the neighborhood granule operation. Further, the neighborhood granular meanshift clustering algorithm is also proposed. Finally, the effectiveness of neighborhood granular meanshift clustering is proved from two aspects of internal metrics (Accuracy and Fowlkes–Mallows Index) and external metric (Silhouette Coeffificient) on multiple datasets from UC Irvine Machine Learning Repository (UCI). We find that the granular meanshift clustering algorithm has a better clustering effect than the traditional clustering algorithms, such as Kmeans, Gaussian Mixture and so on.
Finding the Optimal Topology of an Approximating Neural Network
Authors: Yotov Kostadin , Hadzhikolev Emil , Hadzhikoleva Stanka , Cheresharov Stoyan
Published: January 2023

A large number of researchers spend a lot of time searching for the most efficient neural network to solve a given problem. The procedure of configuration, training, testing, and comparison for expected performance is applied to each experimental neural network. The configuration parameters—training methods, transfer functions, number of hidden layers, number of neurons, number of epochs, and tolerable error—have multiple possible values. Setting guidelines for appropriate parameter values would shorten the time required to create an efficient neural network, facilitate researchers, and provide a tool to improve the performance of automated neural network search methods. The task considered in this paper is related to the determination of upper bounds for the number of hidden layers and the number of neurons in them for approximating artificial neural networks trained with algorithms using the Jacobi matrix in the error function. The derived formulas for the upper limits of the number of hidden layers and the number of neurons in them are proved theoretically, and the presented experiments confirm their validity. They show that the search for an efficient neural network can focus below certain upper bounds, and above them, it becomes pointless. The formulas provide researchers with a useful auxiliary tool in the search for efficient neural networks with optimal topology. They are applicable to neural networks trained with methods such as Levenberg–Marquardt, Gauss–Newton, Bayesian regularization, scaled conjugate gradient, BFGS quasi-Newton, etc., which use the Jacobi matrix.
Portfolio Evaluation with the Vector Distance Based on Portfolio Composition
Authors: Jeon Heonbae , Lee Soonbong , Kim Hongseon , Soh Seung Bum , Kim Seongmoon
Published: January 2023

We propose a novel portfolio evaluation method, a distance-based approach, which directly evaluates the portfolio composition rather than portfolio returns. In this approach, we consider a portfolio as an estimator for an in-sample tangency portfolio, which we define as the optimal reference portfolio. We then evaluate the portfolio by computing its vector distance to the optimal reference portfolio. In search of the proper distance-based performance measure, we choose four representative vector distances and compare their suitability as a new portfolio performance measure. Through extensive statistical analysis, we find that the Euclidean distance is the most proper distance-based performance measure of the four representative vector distances. We further verify that a portfolio with a large Euclidean distance is not desirable because not only does it provide a low utility implied by the first four moments of portfolio returns, but also it is not likely to maintain its long-term performance. Hence, the Euclidean distance can complement the return-based performance measures by confirming the reliability of a portfolio in its investment performance.
Graph-Clustering Method for Construction of the Optimal Movement Trajectory under the Terrain Patrolling
Authors: Rumiantsev Boris V. , Kochkarov Rasul A. , Kochkarov Azret A.
Published: January 2023

The method of the optimal movement trajectory construction in the terrain patrolling tasks is proposed. The method is based on the search of the Hamiltonian circuit on the graph of the terrain map and allows automatic construction of the optimal closed path for arbitrary terrain map. The distinguishing feature of the method is the use of the modified algorithm for the Hamiltonian circuit search. The algorithm can be scaled for the maps corresponding to the graphs with a large (more than 100) number of the vertices, for which the standard brute-force algorithm of the Hamiltonian circuit search requires significantly higher execution time than the proposed algorithm. It is demonstrated that the utilized algorithm possesses 17 times less constant of the time complexity growth than the standard brute-force algorithm. It allows more than one order of magnitude (from 30 to 500 vertices, i.e., approximately to the 17 times) increase of the graph vertices that is used for the Hamiltonian circuit search in the real time (0.1–100 s) regime.
Double-Sources Queuing-Inventory Systems with Finite Waiting Room and Destructible Stocks
Authors: Melikov Agassi , Mirzayev Ramil , Sztrik Janos
Published: January 2023

Models of double-source queuing-inventory systems are studied in the presence of a finite buffer for waiting in the queue of consumer customers, where instant destruction of inventory is possible. It is assumed that the lead times of orders, as well as the cost of delivery from various sources, differ from each other. Replenishment of stocks from various sources is carried out according to the following scheme: if the inventory level drops to the reorder point s, then a regular order for the supply of inventory to a slow source is generated; if the inventory level falls below a certain threshold value r, where r < s, then the system instantly cancels the regular order and generates an emergency order to the fast source. Models of systems that use (s, S) or (s, Q) replenishment policies are studied. Exact and approximate methods for finding the performance measures of the models under study are proposed. The problems of minimizing the total cost are solved by choosing the appropriate values of the parameters s and r when using different replenishment policies. Numerical examples demonstrated the high accuracy of an approximate method as well as compared performance measures of the system under various replenishment policies.
A Trie Based Set Similarity Query Algorithm
Authors: Jia Lianyin , Tang Junzhuo , Li Mengjuan , Li Runxin , Ding Jiaman , Chen Yinong
Published: January 2023

Set similarity query is a primitive for many applications, such as data integration, data cleaning, and gene sequence alignment. Most of the existing algorithms are inverted index based, they usually filter unqualified sets one by one and do not have sufficient support for duplicated sets, thus leading to low efficiency. To solve this problem, this paper designs T-starTrie, an efficient trie based index for set similarity query, which can naturally group sets with the same prefix into one node, and can filter all sets corresponding to the node at a time, thereby significantly improving the candidates generation efficiency. In this paper, we find that the set similarity query problem can be transformed into matching nodes of the first-layer (FMNodes) detecting problem on T-starTrie. Therefore, an efficient FLMNode detection algorithm is designed. Based on this, an efficient set similarity query algorithm, TT-SSQ, is implemented by developing a variety of filtering techniques. Experimental results show that TT-SSQ can be up to 3.10x faster than existing algorithms.
Image Encryption Scheme Based on Newly Designed Chaotic Map and Parallel DNA Coding
Authors: Zhu Shenli , Deng Xiaoheng , Zhang Wendong , Zhu Congxu
Published: January 2023

In this paper, a new one-dimensional fractional chaotic map is proposed and an image encryption scheme based on parallel DNA coding is designed by using the chaotic map. The mathematical model of the new chaotic system combines a sine map and a fraction operation. Compared with some traditional one-dimensional chaotic systems, the new chaotic system has a larger range of chaotic parameters and better chaotic characteristics, which makes it more suitable for applications in information encryption. In addition, an image encryption algorithm based on parallel DNA coding is proposed, which overcomes the shortcoming of common DNA coding-based image encryption algorithms. Parallel computing significantly increases the speed of encryption and decryption algorithms. The initial key of the cryptosystem is designed to be related to the SHA-3 hash value of the plaintext image so that the algorithm can resist a chosen-plaintext attack. Simulation experiments and security analysis results show that the proposed image encryption scheme has good encryption performance and less time overhead, and has strong robustness to noise and data loss attacks, which indicates that the proposed image encryption scheme has good application potential in secure communication applications.
FTIR Characterization of Sulfated Polysaccharides Obtained from Macrocystis integrifolia Algae and Verification of Their Antiangiogenic and Immunomodulatory Potency In Vitro and In Vivo
Authors: Soto-Vásquez Marilú Roxana , Alvarado-García Paúl Alan Arkin , Youssef Fadia S. , Ashour Mohamed L. , Bogari Hanin A. , Elhady Sameh S.
Published: January 2023

The aim of this study was to evaluate the antiangiogenic and immunomodulatory potential of sulfated polysaccharides from the marine algae Macrocystis integrifolia characterized by FTIR. The cytotoxicity of sulfated polysaccharides was evaluated using the 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay. Antiangiogenic activity was evaluated using the chicken chorioallantoic membrane (CAM) assay. Immunomodulatory activity was determined on macrophage functionality and allergic response. The results showed that sulfated polysaccharides significantly decreased angiogenesis in chicken chorioallantoic membranes (p < 0.05). Likewise, they inhibited in vivo chemotaxis and in vitro phagocytosis, the transcription process of genes that code the enzymes cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and nitric oxide synthase-2 (NOS-2) and the nuclear factor kappa-light chain enhancer of activated B cells (NF-κB), showing immunomodulatory properties on the allergic response, as well as an in vivo inhibitory effect in the ovalbumin-induced inflammatory allergy model (OVA) and inhibited lymphocyte proliferation specific to the OVA antigen in immunized mice. Finally, these compounds inhibited the histamine-induced skin reaction in rats, the production of immunoglobulin E (IgE) in mice, and the passive response to skin anaphylaxis in rats. Therefore, the results of this research showed the potential of these compounds to be a promising source for the development of antiangiogenic and immunomodulatory drugs.
Recent Advances in Biologically Active Coumarins from Marine Sources: Synthesis and Evaluation
Authors: Fernández-Peña Laura , Matos Maria João , López Enol
Published: January 2023

Coumarin and its derivatives have significantly attracted the attention of medicinal chemists and chemical biologists due to their huge range of biological, and in particular, pharmacological properties. Interesting families of coumarins have been found from marine sources, which has accelerated the drug discovery process by inspiring innovation or even by the identification of analogues with remarkable biological properties. The purpose of this review is to showcase the most interesting marine-derived coumarins from a medicinal chemistry point of view, as well as the novel and useful synthetic routes described to date to achieve these chemical structures. The references that compose this overview were collected from PubMed, Mendeley and SciFinder.
N-3 PUFA Deficiency Aggravates Streptozotocin-Induced Pancreatic Injury in Mice but Dietary Supplementation with DHA/EPA Protects the Pancreas via Suppressing Inflammation, Oxidative Stress and Apoptosis
Authors: Zou Hong-Yu , Zhang Hui-Juan , Zhao Ying-Cai , Li Xiao-Yue , Wang Yu-Ming , Zhang Tian-Tian , Xue Chang-Hu
Published: January 2023

It has been reported that dietary n-3 polyunsaturated fatty acids (n-3 PUFAs) exert therapeutic potential for the preservation of functional β-cell mass. However, the effect of dietary n-3 PUFA deficiency on pancreatic injury and whether the supplementation of n-3 PUFA could prevent the development of pancreatic injury are still not clear. In the present study, an n-3 PUFA deficiency mouse model was established by feeding them with n-3 PUFA deficiency diets for 30 days. Results showed that n-3 PUFA deficiency aggravated streptozotocin (STZ)-induced pancreas injury by reducing the insulin level by 18.21% and the HOMA β-cell indices by 31.13% and the area of islet by 52.58% compared with the STZ group. Moreover, pre-intervention with DHA and EPA for 15 days could alleviate STZ-induced pancreas damage by increasing the insulin level by 55.26% and 44.33%, the HOMA β-cell indices by 118.81% and 157.26% and reversed the area of islet by 196.75% and 205.57% compared to the n-3 Def group, and the effects were significant compared to γ-linolenic acid (GLA) and alpha-linolenic acid (ALA) treatment. The possible underlying mechanisms indicated that EPA and DHA significantly reduced the ration of n-6 PUFA to n-3 PUFA and then inhibited oxidative stress, inflammation and islet β-cell apoptosis levels in pancreas tissue. The results might provide insights into the prevention and alleviation of pancreas injury by dietary intervention with PUFAs and provide a theoretical basis for their application in functional foods.
Reply to Campbell et al. Comment on “Hogas et al. Salt, Not Always a Cardiovascular Enemy? A Mini-Review and Modern Perspective. Medicina 2022, 58, 1175”
Authors: Hogas Mihai , Stătescu Cristian , Pădurariu Manuela , Ciobica Alin , Bilha Stefana Catalina , Hăisan Anca , Timofte Daniel , Hogas Simona
Published: January 2023

We thank Campbell et al. for their comment [...]
Glypican-3 Differentiates Intraductal Carcinoma and Paget’s Disease from Other Types of Breast Cancer
Authors: Alshammari Fatemah OFO , Satari Anas O. , Aljabali Ahmed S. , Al-mahdy Yanal S. , Alabdallat Yasmeen J. , Al-sarayra Yahya M. , Alkhojah Mohammad A. , Alwardat Abdel rahman M. , Haddad Mansour , Al-sarayreh Sameeh A. , Al-saraireh Yousef M.
Published: January 2023

Background and Objectives: breast cancer remains the most common health burden affecting females worldwide. Despite developments in breast cancer diagnostic approaches and treatment strategies, the clinical management of metastatic breast cancer remains challenging. Thus, there is a need to identify new biomarkers and novel drug targets for breast cancer diagnosis and therapy. Recently, aberrant glypican-3 (GPC3) expression in cancers has gained considerable interest in cancer research. The studies, however, have yielded contradictory results about GPC3 expression in breast cancer. Therefore, the current study aims to analyse GPC3 expression across a large panel of different breast cancer subtypes. Materials and Methods: GPC3 expression was immunohistochemically evaluated in 230 breast cancer patients along with eight normal tissues and its associations to clinical and demographic characteristics, as well as immunohistochemical biomarkers for breast cancer. Moreover, a public database consisting of breast cancer patients’ survival data and GPC3 gene expression information was used to assess the prognostic value of GPC3 in the survival of breast cancer patients. Results: GPC3 expression was only characterised in 7.5% of different histological breast cancer subtypes. None of the normal breast tissues displayed GPC3 expression. Interestingly, all cases of Paget’s disease, as well as 42.9% of intraductal and 16.7% of mucinous carcinomas were found to have GPC3 expression, where it was able to significantly discriminate Paget’s disease and intraductal carcinoma from other breast cancer subtypes. Importantly, GPC3 expression was found more often in tumours that tested positive for the expression of hormone receptors and human epidermal growth factor receptor 2 (HER2), indicating more favourable histological subtypes of breast cancer. Consequently, longer relapse-free survival (RFS) was significantly correlated with higher GPC3 mRNA expression. Conclusions: Our study proposes that GPC3 is a promising breast cancer subtype-specific biomarker. Moreover, GPC3 may have the potential to be a molecular target for the development of new therapeutics for specific subtypes of breast cancer.
Collateral Effect of the Coronavirus Disease 2019 Pandemic on Emergency Department Visits in Korea
Authors: Cho Yeon-Joo , Yeo In-Hwan , Lee Dong-Eun , Kim Jong-Kun , Kim Yun-Jeong , Kim Chang-Ho , Choe Jae-Young , Park Jung-Bae , Seo Kang-Suk , Yu Byung-Hyuk , Lee Won-Kee
Published: January 2023

Background and Objectives: The ongoing coronavirus disease 2019 (COVID-19) pandemic represents a global public health crisis that has had a serious impact on emergency department (ED) utilization trends. The aim of this study was to investigate the collateral effects of the COVID-19 pandemic on ED utilization trends by patients with mild and severe conditions as well as on 7-day fatality rates. Materials and Methods: We analyzed entries in the Korean National Health Insurance claims database between 1 January 2018 and 31 December 2020. Six target patient groups were identified using the main diagnosis codes in the 10th revision of the International Classification of Diseases. Numbers of patients visiting the ED, their age, regional differences, 7-day fatality rate, and rate of emergency procedures were compared between 2018 and 2019 as the control period and 2020, when the COVID-19 pandemic was in full force. Results: During the 2020 COVID-19 pandemic, the number of patients who visited the ED with low-acuity diseases and severe acute respiratory infection diseases sharply decreased to −46.22% and −56.05%, respectively. However, the 7-day fatality rate after ED visits for low-acuity diseases and severe acute respiratory infection diseases increased to 0.04% (p < 0.01), and 1.65% (p < 0.01), respectively, in 2020 compared to that in the control period. Conclusions: During the 2020 COVID-19 pandemic, ED utilization impacted and 7-day fatality rate after ED visit increased. Health authorities and health care providers must strive to ensure prompt delivery of optimal care in EDs for patients with severe or serious symptoms and time-dependent diseases, even during the ongoing COVID-19 or potential future pandemics.
Endovascular Treatment of Basilar Artery Occlusion: What Can We Learn from the Results?
Authors: Ekkert Aleksandra , Jokimaitytė Une , Tutukova Valerija , Lengvenis Givi , Masiliūnas Rytis , Jatužis Dalius
Published: January 2023

Background and Objectives: Current guidelines lack specific endovascular treatment (EVT) recommendations for posterior circulation stroke (PCS). The results of earlier studies are controversial. We aimed to compare early hospital outcomes of stroke caused by large-vessel occlusion (LVO) treated with EVT or bridging therapy (BT) in anterior circulation stroke (ACS) versus PCS (middle cerebral artery occlusion (MCAO) and basilar artery occlusion (BAO), and establish the risk factors for poor outcome. Materials and Methods: we analyzed the data of 279 subjects treated with EVT due to LVO-caused stroke in a comprehensive stroke centre in 2015–2021. The primary outcome was hospital mortality, secondary outcomes were National Institutes of Health Stroke Scale (NIHSS) after 24 h, early neurological deterioration, futile recanalization (FR), the ambulatory outcome at discharge, and complications. Results: BAO presented with higher baseline NIHSS scores (19 vs. 14, p < 0.001), and longer door-to-puncture time (93 vs. 82 min, p = 0.034), compared to MCAO. Hospital mortality and the percentage of FR were the same in BAO and almost two times higher than in MCAO (20.0% vs. 10.3%, p = 0.048), other outcomes did not differ. In BAO, unsuccessful recanalization was the only significant predictor of the lethal outcome, though there were trends for PAD and RF predicting lethal outcome. A trend for higher risk of symptomatic intracranial hemorrhage (sICH) was observed in the BAO group when BT was applied. Nevertheless, neither BT nor sICH predicted lethal outcomes in the BAO group. Conclusions: Compared to the modern gold standard of EVT in the ACS, early outcomes in BAO remain poor, there is a substantial amount of FR. Nevertheless, unsuccessful recanalization remains the strongest predictor of lethal outcomes. BT in PCS might pose a higher risk for sICH, but not the lethal outcome, although this finding requires further investigation in larger trials.
The Association between Brain-Derived Neurotrophic Factor (BDNF) Protein Level and Body Mass Index
Authors: Taha Murtada A. , AL-maqati Thekra N. , Alnaam Yaser A. , Alharbi Sulaiman S. , Khaneen Rajaa , Almutairi Hajra , AL-harbi Mashael
Published: January 2023

Background and Objectives: Obesity is a major health concern worldwide. Many studies emphasize the important role of brain-derived neurotrophic factor (BDNF) in regulating appetite and body weight. We aimed to investigate the association between BDNF protein serum levels and body mass index (BMI). Materials and Methods: We conducted a cross-sectional study among 108 healthy adult participants divided into six categories depending on their body mass index (BMI). The ages of the participants ranged between 21 to 45 years. The BDNF serum level was measured using the enzyme-linked immunosorbent assay (ELISA) technique. Results: A Kruskal–Wallis test showed a significant difference in BDNF between the different BMI categories, χ2(2) = 24.201, p < 0.001. Our data also showed that BDNF levels were significantly lower in people with obesity classes II and III than those of normal weight (p < 0.05). The Spearman rank correlation test was statistically significant with negative correlations between the BMI and BDNF (r) = −0.478, (p < 0.01). Moreover, we observed a negative dose-dependent relationship pattern between BMI categories and the levels of circulating BDNF protein. Conclusions: In this study, our data support the hypothesis that low serum levels of BDNF are associated with high BMI and obesity in Saudi adults.
Safety and Evaluation of the Immune Response of Coronavirus Nosode (BiosimCovex) in Healthy Volunteers: A Preliminary Study Extending the Homeopathic Pathogenetic Trial
Authors: Herscu Paul , Talele Gitanjali , Vaidya Shashikant , Shah Rajesh
Published: January 2023

Objectives: Regulatory clinical Phase I studies are aimed at establishing the human safety of an active pharmaceutical agent to be later marketed as a drug. Since homeopathic medicines are prepared by a potentizing method using alcohol, past a certain dilution, their toxicity/infectivity is assumed to be unlikely. We aimed to develop a bridge study between homeopathic pathogenetic trials and clinical trials. The primary purpose was to evaluate the safety of a nosode, developed from clinical samples of a COVID-19 patient. The secondary objectives were to explore whether a nosode developed for a specific clinical purpose, such as use during an epidemic, may elicit laboratory signals worthy of further exploration. Methods: An open-label study was designed to evaluate the safety and immune response of the Coronavirus nosode BiosimCovex, given orally on three consecutive days to ten healthy volunteers. Clinical examinations, laboratory safety and immune parameters were established. Interferon–gamma, Interleukin-6, and CD 4 were measured. (CTRI registration number: CTRI/2020/05/025496). Results: No serious/fatal adverse events were reported. Laboratory tests to measure safety were unchanged. Three subjects showed elevated Interleukin-6 (IL-6) on day 17 in comparison to the baseline, and ten subjects showed elevated IL-6 on day 34. A significant difference between IL-6 observations, calculated by repeated measures ANOVA, was found to be highly significant. On day 60, the IL-6 values of nine subjects were found to return to normal. Corresponding CD4 cell elevation was observed on day 60, when compared to day 34. Conclusions: HPT may potentially extend into physiological changes with regards to immune response and should encourage future studies.
Chemical Composition of Ducrosia flabellifolia L. Methanolic Extract and Volatile Oil: ADME Properties, In Vitro and In Silico Screening of Antimicrobial, Antioxidant and Anticancer Activities
Authors: Snoussi Mejdi , Lajimi Ramzi Hadj , Badraoui Riadh , Al-Reshidi Mousa , Abdulhakeem Mohammad A. , Patel Mitesh , Siddiqui Arif Jamal , Adnan Mohd , Hosni Karim , De Feo Vincenzo , Polito Flavio , Kadri Adel , Noumi Emira
Published: January 2023

In the present study, the chemical composition of the volatile oil and methanolic extract from Ducrosia flabellifolia Boiss. was investigated. The antimicrobial, antioxidant, and anticancer activities of the methanolic extract from D. flabellifolia aerial parts were screened using experimental and computational approaches. Results have reported the identification of decanal (28.31%) and dodecanal (16.93%) as major compounds in the essential oil obtained through hydrodistillation. Farnesyl pyrophosphate, Methyl 7-desoxypurpurogallin-7-carboxylate trimethyl ether, Dihydro-Obliquin, Gummiferol, 2-Phenylaminoadenosine, and 2,4,6,8,10-dodecapentaenal, on the other hand, were the dominant compounds in the methanolic extract. Moreover, the tested extract was active against a large collection of bacteria and yeast strains with diameter of growth inhibition ranging from 6.67 ± 0.57 mm to 17.00 ± 1.73 mm, with bacteriostatic and fungicidal activities against almost all tested microorganisms. In addition, D. flabellifolia methanolic extract was dominated by phenolic compounds (33.85 ± 1.63 mg of gallic acid equivalent per gram of extract) and was able to trap DPPH• and ABTS•+ radicals with IC50 about 0.05 ± 0 mg/mL and 0.105 ± 0 mg/mL, respectively. The highest percentages of anticancer activity were recorded at 500 µg/mL for all cancer cell lines with IC50 about 240. 56 µg/mL (A-549), 202.94 µg/mL (HCT-116), and 154.44 µg/mL (MCF-7). The in-silico approach showed that D. flabellifolia identified compounds bound 1HD2, 2XCT, 2QZW, and 3LN1 with high affinities, which together with molecular interactions and the bond network satisfactorily explain the experimental results using antimicrobial, antioxidant, and anticancer assays. The obtained results highlighted the ethnopharmacological properties of the rare desertic D. flabellifolia plant species growing wild in Hail region (Saudi Arabia).