bluuebunny/crossref_metadata_2025 huggingface dataset:
Damage Propagation by Cyclic Loading in Drilled Carbon/Epoxy Plates
Authors: Durão Luis M. P. , Matos João E. , Loureiro Nuno C. , Esteves José L. , Fernandes Susana C. F.
Published: March 2023

Fiber reinforced composites are widely used in the production of parts for load bearing structures. It is generally recognized that composites can be affected both by monotonic and cyclic loading. For assembly purposes, drilling is needed, but holes can act as stress concentration notches, leading to damage propagation and failure. In this work, a batch of carbon/epoxy plates is drilled by different drill geometries, while thrust force is monitored and the hole’s surrounding region is inspected. Based on radiographic images, the area and other features of the damaged region are computed for damage assessment. Finally, the specimens are subjected to Bearing Fatigue tests. Cyclic loading causes ovality of the holes and the loss of nearly 10% of the bearing net strength. These results can help to establish an association between the damaged region and the material’s fatigue resistance, as larger damage extension and deformation by cyclic stress contribute to the loss of load carrying capacity of parts.
Broadband Metasurface Absorber Based on an Optimal Combination of Copper Tiles and Chip Resistors
Authors: Kim Yongjune , Lee Jeong-Hae
Published: March 2023

In this study, a broadband metasurface absorber composed of an optimal combination of copper tiles connected with four chip resistors is designed and experimentally verified. After fixing the locations of the chip resistors and setting their resistances to 100 Ω, the genetic algorithm (GA) is utilized to design the optimal copper tile pattern for broadband absorption. The optimal combination of the copper tiles is identified by determining the states of the square tile pairs between copper or air, depending on the one or zero states of the bit sequence created by GA, respectively. The full-wave simulation results of the optimized metasurface absorber confirmed a −10 dB reflectance bandwidth within the frequency range of 6.57 to 12.73 GHz for the normal incidence condition, with the fractional bandwidth being 63.83%. The accuracy of the metasurface absorber was verified through an experimental result that matched well with the full-wave simulated one.
Comparison to Micro Wear Mechanism of PVD Chromium Coatings and Electroplated Hard Chromium
Authors: Yang Zhongyi , Zhang Ning , Li Hongtao , Chen Bo , Yang Bo
Published: March 2023

Electroplated hard chromium (EPHC) has been widely used in industry due to its excellent mechanical properties, but the development of this technology is limited by environmental risks. The physical vapor deposition (PVD) process has shown promise as an alternative to EPHC for producing chromium-based coatings. In this research, we investigate the microstructure and wear resistance of pure chromium coatings using two PVD techniques, namely, magnetron sputtering ion plating (MSIP) and micro-arc ion plating (MAIP), which are compared to EPHC. To assess wear resistance, we evaluated factors such as hardness, coating base bonding force, wear rate and friction coefficient via friction and wear experiments. The results show that, in terms of microstructure, while the EPHC coating does not exhibit a strong preferred growth orientation, the PVD coatings exhibit an obvious preferred growth orientation along the (110) direction. The average grain size of the EPHC coating is the smallest, and the PVD chromium coatings show a higher hardness than the EPHC coating. The results of pin-on-disk tests show that there is little difference in friction coefficients between EPHC and MAIP chromium plating; however, the MAIP chromium coating showed an excellent specific wear rate (as low as 1.477 × 10−13 m3/Nm). The wear condition of the MAIP chromium coating is more stable than that of the EPHC coating, indicating its potential as a replacement for EPHC.
Dynamic Simulation of Multiple Launch Rocket System Marching Fire Based on the Fuzzy Adaptive Sliding Mode Control
Authors: Qu Pu , Sun Zhiqun , Li Qiang , Zhang Jiabo , Liu Pengzhan , Zhou Dongmo
Published: March 2023

This paper presents a servo control method for the multiple launch rocket system (MLRS) launcher during marching fire operations. The MLRS, being a complex nonlinear system, presents challenges in designing its servo controller. To address this, we introduce the fuzzy adaptive sliding mode control (FASMC) approach. The permanent magnet synchronous motor (PMSM) and controller of the MLRS were simulated in the MATLAB/Simulink environment. The dynamic model of the MLRS during marching fire was established using multi-body system theory, vehicle mechanics, and launch dynamics. The dynamic model was then integrated with the FASMC-based controller using the Adams/View module. Numerical calculations were performed to demonstrate the control performance and the effectiveness and applicability of the proposed approach were validated through a comparison experiment between FASMC and other common control methods.
Aerodynamic Performance of V8 Octorotor MAV with Different Rotor Configurations in Hover
Authors: Lei Yao , Feng Zhicheng , Ma Chensong
Published: March 2023

A new multirotor aerial vehicle with two rotor arms formed in a V-shape configuration is introduced in this paper. To figure out the aerodynamic interference effects between rotors as an implication of the control method, this paper discusses the aerodynamic performance of the V8 Octorotor MAV with different rotor spacing using both experiments and simulations. A hovering experiment platform is applied to obtain the thrust, power consumption and rotational speed. PL (power loading) is promoted to characterize the aerodynamic performance of the V8 Octorotor MAV. The velocity vector, streamline and turbulent vortices’ distribution of the V8 Octorotor MAV are presented as the simulation results, which indicates that turbulence intensity generated by the MAV dissipates faster in a large rotor spacing. Therefore, rotor vibration is reduced with an increased hovering stability, and the power loading is much improved at G3 (1.2D–1.4D–1.6D–1.8D) with a better aerodynamic performance both with a thrust increment and power decrement.
Investigation of Transfer Learning for Tunnel Support Design
Authors: Mitelman Amichai , Urlainis Alon
Published: March 2023

The potential of machine learning (ML) tools for enhancing geotechnical analysis has been recognized by several researchers. However, obtaining a sufficiently large digital dataset is a major technical challenge. This paper investigates the use of transfer learning, a powerful ML technique, used for overcoming dataset size limitations. The study examines two scenarios where transfer learning is applied to tunnel support analysis. The first scenario investigates transferring knowledge between a ground formation that has been well-studied to a new formation with very limited data. The second scenario is intended to investigate whether transferring knowledge is possible from a dataset that relies on simplified tunnel support analysis to a more complex and realistic analysis. The technical process for transfer learning involves training an Artificial Neural Network (ANN) on a large dataset and adding an extra layer to the model. The added layer is then trained on smaller datasets to fine-tune the model. The study demonstrates the effectiveness of transfer learning for both scenarios. On this basis, it is argued that, with further development and refinement, transfer learning could become a valuable tool for ML-related geotechnical applications.
Modeling Extractive Question Answering Using Encoder-Decoder Models with Constrained Decoding and Evaluation-Based Reinforcement Learning
Authors: Li Shaobo , Sun Chengjie , Liu Bingquan , Liu Yuanchao , Ji Zhenzhou
Published: March 2023

Extractive Question Answering, also known as machine reading comprehension, can be used to evaluate how well a computer comprehends human language. It is a valuable topic with many applications, such as in chatbots and personal assistants. End-to-end neural-network-based models have achieved remarkable performance on these tasks. The most frequently used approach to extract answers with neural networks is to predict the answer’s start and end positions in the document, independently or jointly. In this paper, we propose another approach that considers all words in an answer jointly. We introduce an encoder-decoder model to learn from all words in the answer. This differs from previous works. which usually focused on the start and end and ignored the words in the middle. To help the encoder-decoder model to perform this task better, we employ evaluation-based reinforcement learning with different reward functions. The results of an experiment on the SQuAD dataset show that the proposed method can outperform the baseline in terms of F1 scores, offering another potential approach to solve the extractive QA task.
Nonlocality of Star-Shaped Correlation Tensors Based on the Architecture of a General Multi-Star-Network
Authors: Xiao Shu , Guo Zhihua , Cao Huaixin , Han Kanyuan , Yang Ying
Published: March 2023

In this work, we study the nonlocality of star-shaped correlation tensors (SSCTs) based on a general multi-star-network MSN(m,n1,…,nm). Such a network consists of 1+m+n1+⋯+nm nodes and one center-node A that connects to m star-nodes B1,B2,…,Bm while each star-node Bj has nj+1 star-nodes A,C1j,C2j,…,Cnjj. By introducing star-locality and star-nonlocality into the network, some related properties are obtained. Based on the architecture of such a network, SSCTs including star-shaped probability tensors (SSPTs) are proposed and two types of localities in SSCTs and SSPTs are mathematically formulated, called D-star-locality and C-star-locality. By establishing a series of characterizations, the equivalence of these two localities is verified. Some necessary conditions for a star-shaped CT to be D-star-local are also obtained. It is proven that the set of all star-local SSCTs is a compact and path-connected subset in the Hilbert space of tensors over the index set ΔS and has least two types of star-convex subsets. Lastly, a star-Bell inequality is proved to be valid for all star-local SSCTs. Based on our inequality, two examples of star-nonlocal MSN(m,n1,…,nm) are presented.
A Stochastic Weather Model for Drought Derivatives in Arid Regions: A Case Study in Qatar
Authors: Paek Jayeong , Pollanen Marco , Abdella Kenzu
Published: March 2023

In this paper, we propose a stochastic weather model consisting of temperature, humidity, and precipitation, which is used to calculate a reconnaissance drought index (RDI) in Qatar. The temperature and humidity models include stochastic differential equations and utilize an adjusted Ornstein–Uhlenbeck (O–U) process. For the precipitation model, a first-order Markov chain is used to differentiate between wet and dry days and the precipitation amount on wet days is determined by a probability distribution. Five different probability distributions were statistically tested to obtain an appropriate precipitation amount. The evapotranspiration used in the RDI calculation incorporates crop coefficient values, depends on the growth stages of the crops, and provides a crop-specific and more realistic representation of the drought conditions. Five different evapotranspiration formulations were investigated in order to obtain the most accurate RDI values. The calculated RDI was used to assess the intensity of drought in Doha, Qatar, and could be used for the pricing of financial drought derivatives, a form of weather derivative. These derivatives could be used by agricultural producers to hedge against the economic effects of droughts.
Existence Theoremsfor Solutions of a Nonlinear Fractional-Order Coupled Delayed System via Fixed Point Theory
Authors: Liu Xin , Chen Lili , Zhao Yanfeng
Published: March 2023

In this paper, the problem of the existence and uniqueness of solutions for a nonlinear fractional-order coupled delayed system with a new kind of boundary condition is studied. For this reason, we transform the above problem into an equivalent fixed point problem using the integral operator. Moreover, by applying fixed point theorems, a novel set of sufficient conditions that guarantee the existence and uniqueness of solutions of the coupled system is derived. Eventually, an example is presented to illustrate the effectiveness of the obtained results.
Brain Tumor Segmentation Using a Patch-Based Convolutional Neural Network: A Big Data Analysis Approach
Authors: Ullah Faizan , Salam Abdu , Abrar Mohammad , Amin Farhan
Published: March 2023

Early detection of brain tumors is critical to ensure successful treatment, and medical imaging is essential in this process. However, analyzing the large amount of medical data generated from various sources such as magnetic resonance imaging (MRI) has been a challenging task. In this research, we propose a method for early brain tumor segmentation using big data analysis and patch-based convolutional neural networks (PBCNNs). We utilize BraTS 2012–2018 datasets. The data is preprocessed through various steps such as profiling, cleansing, transformation, and enrichment to enhance the quality of the data. The proposed CNN model utilizes a patch-based architecture with global and local layers that allows the model to analyze different parts of the image with varying resolutions. The architecture takes multiple input modalities, such as T1, T2, T2-c, and FLAIR, to improve the accuracy of the segmentation. The performance of the proposed model is evaluated using various metrics, such as accuracy, sensitivity, specificity, Dice similarity coefficient, precision, false positive rate, and true positive rate. Our results indicate that the proposed method outperforms the existing methods and is effective in early brain tumor segmentation. The proposed method can also assist medical professionals in making accurate and timely diagnoses, and thus improve patient outcomes, which is especially critical in the case of brain tumors. This research also emphasizes the importance of big data analysis in medical imaging research and highlights the potential of PBCNN models in this field.
Seasonal Molecular Difference in Fibrillar Collagen Extracts Derived from the Marine Sponge Chondrosia reniformis (Nardo, 1847) and Their Impact on Its Derived Biomaterials
Authors: Tassara Eleonora , Orel Boaz , Ilan Micha , Cavallo Dario , Dodero Andrea , Castellano Maila , Vicini Silvia , Giovine Marco , Pozzolini Marina
Published: March 2023

Chondrosia reniformis (Nardo, 1847) is a marine sponge of high biotechnological interest both for its natural compound content and for its peculiar collagen, which is suitable for the production of innovative biomaterials in the form, for instance, of 2D membranes and hydrogels, exploitable in the fields of tissue engineering and regenerative medicine. In this study, the molecular and chemical-physical properties of fibrillar collagen extracted from specimens collected in different seasons are studied to evaluate the possible impact of sea temperature on them. Collagen fibrils were extracted from sponges harvested by the Sdot Yam coast (Israel) during winter (sea temperature: 17 °C) and during summer (sea temperature: 27 °C). The total AA composition of the two different collagens was evaluated, together with their thermal stability and glycosylation level. The results showed a lower lysyl-hydroxylation level, lower thermal stability, and lower protein glycosylation level in fibrils extracted from 17 °C animals compared to those from 27 °C animals, while no differences were noticed in the GAGs content. Membranes obtained with fibrils deriving from 17 °C samples showed a higher stiffness if compared to the 27 °C ones. The lower mechanical properties shown by 27 °C fibrils are suggestive of some unknown molecular changes in collagen fibrils, perhaps related to the creeping behavior of C. reniformis during summer. Overall, the differences in collagen properties gain relevance as they can guide the intended use of the biomaterial.
Caesarean Section Delivery Is Associated with Childhood Overweight and Obesity, Low Childbirth Weight and Postnatal Complications: A Cross-Sectional Study
Authors: Papadopoulou Sousana K , Mentzelou Maria , Pavlidou Eleni , Vasios Georgios K , Spanoudaki Maria , Antasouras Georgios , Sampani Anastasia , Psara Evmorfia , Voulgaridou Gavriela , Tsourouflis Gerasimos , Mantzorou Maria , Giaginis Constantinos
Published: March 2023

Background and Objectives: In the last decades, simultaneously increasing trends have been recorded for both caesarean section delivery and childhood overweight/obesity around the world, which are considered serious public health concerns, negatively affecting child health. Aim: The present study aims to investigate whether caesarean section is associated with the increased rates of childhood overweight/obesity, low childbirth anthropometric indices and postnatal complications in pre-school age. Materials and Methods: This is a cross-sectional study in which 5215 pre-school children aged 2–5 years old were enrolled from nine different Greek regions after applying specific inclusion and exclusion criteria. Non-adjusted and adjusted statistical analysis was performed to assess the impact of caesarean section in comparison to vaginal delivery. Results: Children delivered by caesarean section were significantly more frequently overweight or obese at the age of 2–5 years, also presenting a higher prevalence of low birth weight, length and head circumference. Caesarean section was also associated with higher incidence of asthma and diabetes type I at the age of 2–5 years. In a multivariate analysis, caesarean section increased the risk of childhood overweight/obesity and low childbirth anthropometric indices even if adjusting for several childhood and maternal confounding factors. Conclusions: Increasing trends were recorded for both caesarean section delivery and childhood overweight/obesity, which are considered serious public health concerns. Caesarean section independently increased childhood overweight/obesity in pre-school age, highlighting the emergent need to promote health policies and strategies to inform future mothers about its short and long-term risks and that this mode of delivery should preferably be performed only when there are strong medical recommendations in emergency obstetric conditions.
Pharmacological Mechanism of Aucklandiae Radix against Gastric Ulcer Based on Network Pharmacology and In Vivo Experiment
Authors: Feng Lan , A Lisha , Li Huifang , Mu Xiyele , Ta Na , Bai Laxinamujila , Fu Minghai , Chen Yongsheng
Published: March 2023

Background and Objectives: Aucklandiae Radix is a well-known medicinal herb that is often used to treat gastric ulcer, but its molecular mechanism of anti-ulcer action is poorly understood. This research aimed to reveal the potential active components, core targets, and mechanisms of Aucklandiae Radix in treating gastric ulcer by combining network pharmacology and animal experimentation. Materials and Methods: First, a network pharmacology strategy was used to predict the main components, candidate targets, and potential signaling pathways. Molecular docking was then used to confirm the binding affinity between the main components and primary targets. Finally, rats were treated with indomethacin 30 mg/kg to establish a gastric ulcer model. Aucklandiae Radix extract (0.15, 0.3, and 0.6 g/kg) was pre-treated in rats by oral gavage for 14 days, and the protective effect and candidate targets of network pharmacology were validated through morphological observation, pathological staining, and biochemical index detection. Results: A total of eight potential active components and 331 predicted targets were screened from Aucklandiae Radix, 37 of which were common targets with gastric ulcer. According to the component–target network and protein-protein interaction (PPI) network, stigmasterol, mairin, sitosterol, and dehydrocostus lactone were identified as the key components, and RAC-alpha serine/threonine-protein kinase (AKT1), prostaglandin-endoperoxide synthase 2 (PTGS2), interleukin 1 beta (IL1B), caspase-3 (CASP3), and CASP8 were selected as the core targets. Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment results revealed the pharmacological mechanism of Aucklandiae Radix against gastric ulcer related to many biological processes and pathways, including antibacterial, anti-inflammatory, prostaglandin receptor response, and apoptosis. Molecular docking verification showed that the key components and core targets had good binding affinities. In the in vivo experiments, Aucklandiae Radix notably relieved the gastric ulcer by reducing the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and myeloperoxidase (MPO) while improving the gastric histopathological features. Conclusion: The overall findings suggest that Aucklandiae Radix treats gastric ulcer with a multi-component, multi-target, and multi-mechanism model.
Subcutaneous Myoepithelioma in the Extremity: A Potential Pitfall in the Differential Diagnosis of Subcutaneous Tumors
Authors: Koo Minsun , Wi Young Chan , Kim Jimin , Lee Sheen-Woo
Published: March 2023

We present a rare case of myoepithelioma in the subcutaneous layer of the shoulder with ultrasonography (US) and magnetic resonance imaging (MRI). US showed a lobulated hyperechoic mass, leading to an impression of lipoma. MRI showed the mass with low signal intensity on T1-weighted images (T1WI), high signal intensity on fat-suppressed T2-weighted images (T2WI), intermediate signal intensity on T2WI, and intense enhancement with adjacent fascial thickening. Imaging findings of soft tissue myoepithelioma have not been established. We report its US and MRI features mimicking features from a lipomatous tumor to infiltrative malignancy. Although soft tissue myoepithelioma has nonspecific image findings to confirm its diagnosis, some findings may help to make the differential diagnosis. Preoperative pathologic confirmation is recommended in a soft tissue neoplasm.
Contamination by Antibiotic-Resistant Bacteria on Cell Phones of Vendors in a Peruvian Market
Authors: Gómez-Gonzales Walter , Alvarado-Garcia Anthony , Suárez-Mamani Marytté , Dámaso-Mata Bernardo , Panduro-Correa Vicky , Maguiña Jorge L. , Pecho-Silva Samuel , Rabaan Ali A. , Rodriguez-Morales Alfonso J. , Arteaga-Livias Kovy
Published: March 2023

Background and Objectives. Multiple studies have evaluated the presence of bacterial contamination on cell phones in clinical settings; however, the presence and transmission of antibiotic-resistant bacteria on cell phones in the community have not been adequately elucidated. Material and Methods. A cross-sectional study was carried out to determine the presence of bacteria resistant to antibiotics on the cell phones of vendors in a Peruvian market and the associated factors. A sample of 127 vendors was obtained through stratified probabilistic sampling using a data collection form validated by experts. Cell phone samples were cultured using a standard technique, and antibiotic sensitivity was determined using the Kirby–Bauer technique. Chi-squared and Mann-Whitney U tests were used to determine factors associated with resistance in cell phone cultures. Results. Among the cell phones, 92.1% showed bacterial growth, predominantly Gram-positive bacteria (coagulase-negative staphylococci and Staphylococcus aureus), and 17% of the cultures showed resistance to at least three antibiotics evaluated. Two strains fell into the category of methicillin-resistant S. aureus, and three strains of E. coli had resistance to carbapenems. Conclusions. A short distance between customers and vendors, lack of a cell phone case, and having a cell phone with touchscreen are factors associated with antibiotic-resistant bacteria on cell phones.
Gaucher: A Systematic Review on Oral and Radiological Aspects
Authors: Minervini Giuseppe , Franco Rocco , Marrapodi Maria Maddalena , Mehta Vini , Fiorillo Luca , Badnjević Almir , Cervino Gabriele , Cicciù Marco
Published: March 2023

Background and Objectives: Gaucher disease (GD) is a lysosomal storage disorder with the genetic autosomal recessive transmission. Bone involvement is a prevalent finding in Gaucher disease. It causes deformity and limits daily activities and the quality of life. In 75% of patients, there is bone involvement. This review aims to evaluate the principal findings in the jaw by a Cone-beam computed tomography (CBTC) and X-ray orthopantomography; Materials and Methods: PubMed, Web of Science, Lilacs and Scopus were systematically searched until 31 December 2022. In addition, a manual search was performed using the bibliography of selected articles and a Google Scholar search. Clinical studies were selected that considered principal radiographic findings in radiography in a group of patients affected by GD. Results: Out of 5079 papers, four studies were included. The main findings are generalized rarefaction and enlarged narrow space, anodontia. Conclusions: The exact mechanism of bone manifestation is probably due to the infiltration of Gaucher cells in the bone marrow and, consequently, the destruction of bone architecture. All long bones are a potential means of skeletal manifestation. The jaw is more affected than the maxilla, and the principal features are cortical thinning, osteosclerosis, pseudocystic lesions, mental demineralization, flattening in the head of the condyle, effacement of anatomical structures, thickening of maxillary sinus mucosa. The dentist plays a crucial role in diagnosing and treating these patients. Sometimes the diagnosis can be made by a simple panoramic radiograph. All long bones are affected, and the mandible is particularly involved.
The Philadelphia Chromosome, from Negative to Positive: A Case Report of Relapsed Acute Lymphoblastic Leukemia Following Allogeneic Stem Cell Transplantation
Authors: Marinescu Elena-Cristina , Bumbea Horia , Iordan Iuliana , Dumitru Ion , Soare Dan , Ciufu Cristina , Gaman Mihaela
Published: March 2023

Relapsed acute lymphoblastic leukemia (ALL) represents a continuous challenge for the clinician. Despite recent advances in treatment, the risk of relapse remains significant. The clinical, biological, cytogenetic, and molecular characteristics may be different at the time of relapse. Current comprehensive genome sequencing studies suggest that most relapsed patients, especially those with late relapses, acquire new genetic abnormalities, usually within a minor clone that emerges after ALL diagnosis. We report the case of a 23-year-old young woman diagnosed with Philadelphia chromosome-negative B cell acute lymphoblastic leukemia. The patient underwent allogeneic stem cell transplantation (allo-HSCT) after complete remission. Despite having favorable prognostic factors at diagnosis, the disease relapsed early after allo-HSCT. The cytogenetic and molecular exams at relapse were positive for the Philadelphia chromosome, respectively for the Bcr-Abl transcript. What exactly led to the recurrence of this disease in a more aggressive cytogenetic and molecular form, although there were no predictive elements at diagnosis?
Study of CFD-DEM on the Impact of the Rolling Friction Coefficient on Deposition of Lignin Particles in a Single Ceramic Membrane Pore
Authors: Wang Hao , Wang Xinyuanrui , Wu Yongping , Wang Song , Wu Junfei , Fu Ping , Li Yang
Published: March 2023

The discrete element method coupled with the computational fluid dynamic (CFD-DEM) method is effective for studying the micro-flow process of lignin particles in ceramic membranes. Lignin particles may exhibit various shapes in industry, so it is difficult to model their real shapes in CFD-DEM coupled solutions. Meanwhile, the solution of non-spherical particles requires a very small time-step, which significantly lowers the computational efficiency. Based on this, we proposed a method to simplify the shape of lignin particles into spheres. However, the rolling friction coefficient during the replacement was hard to be obtained. Therefore, the CFD-DEM method was employed to simulate the deposition of lignin particles on a ceramic membrane. Impacts of the rolling friction coefficient on the deposition morphology of the lignin particles were analyzed. The coordination number and porosity of the lignin particles after deposition were calculated, based on which the rolling friction coefficient was calibrated. The results indicated that the deposition morphology, coordination number, and porosity of the lignin particles can be significantly affected by the rolling friction coefficient and slightly influenced by that between the lignin particles and membranes. When the rolling friction coefficient among different particles increased from 0.1 to 3.0, the average coordination number decreased from 3.96 to 2.73, and the porosity increased from 0.65 to 0.73. Besides, when the rolling friction coefficient among the lignin particles was set to 0.6–2.4, the spherical lignin particles could replace the non-spherical particles.
Applicability of Composite Magnetic Membranes in Separation Processes of Gaseous and Liquid Mixtures—A Review
Authors: Jakubski Łukasz , Dudek Gabriela , Turczyn Roman
Published: March 2023

Recent years have shown a growing interest in the application of membranes exhibiting magnetic properties in various separation processes. The aim of this review is to provide an in-depth overview of magnetic membranes that can be successfully applied for gas separation, pervaporation, ultrafiltration, nanofiltration, adsorption, electrodialysis, and reverse osmosis. Based on the comparison of the efficiency of these separation processes using magnetic and non-magnetic membranes, it has been shown that magnetic particles used as fillers in polymer composite membranes can significantly improve the efficiency of separation of both gaseous and liquid mixtures. This observed separation enhancement is due to the variation of magnetic susceptibility of different molecules and distinct interactions with dispersed magnetic fillers. For gas separation, the most effective magnetic membrane consists of polyimide filled with MQFP-B particles, for which the separation factor (αrat O2/N2) increased by 211% when compared to the non-magnetic membrane. The same MQFP powder used as a filler in alginate membranes significantly improves water/ethanol separation via pervaporation, reaching a separation factor of 12,271.0. For other separation methods, poly(ethersulfone) nanofiltration membranes filled with ZnFe2O4@SiO2 demonstrated a more than four times increase in water flux when compared to the non-magnetic membranes for water desalination. The information gathered in this article can be used to further improve the separation efficiency of individual processes and to expand the application of magnetic membranes to other branches of industry. Furthermore, this review also highlights the need for further development and theoretical explanation of the role of magnetic forces in separation processes, as well as the potential for extending the concept of magnetic channels to other separation methods, such as pervaporation and ultrafiltration. This article provides valuable insights into the application of magnetic membranes and lays the groundwork for future research and development in this area.
Investigation on the Alloy Mixing and Inclusion Removement through Using a New Slot-Porous Matched Tuyeres
Authors: Li Xianglong , Wang Huihua , Tian Jun , Wang Deyong , Qu Tianpeng , Hou Dong , Hu Shaoyan , Wu Guangjun
Published: March 2023

A mathematical model was developed to investigate the refining process through using slot-porous matched dual tuyeres. In this model, the bubble expansion is considered through the ideal gas state equation. The density variation of bubbles is calculated through the mass conservation equation. The coalescence and breakup of bubbles are tracked using the discrete particle model (DPM). The transient flow is computed through the k-ε model with three continuous phases (air–slag–steel). Comparisons were made between traditional porous–porous and the new slot–porous tuyeres, mainly focusing on the mixing behavior and inclusion removement ratio. The results show that, for traditional porous–porous matched tuyeres (P-P mode), the inclusion removement ratio is 34.14%; by comparison, after employing the slot–porous matched tuyeres (S-P mode), the inclusion removements ratio rises to 36.34%. The mixing time is also shortened by 18.74% by using the S-P mode. The reason for this phenomenon is because the slot tuyere produces a strong asymmetry that drives more liquid at the bottom of the ladle. The new tuyere match takes advantage of porous and slot tuyeres, and the mixing behavior and inclusion removements are improved. The result is beneficial for future refining.
Compensation Method for the Nonlinear Characteristics with Starting Error of a Piezoelectric Actuator in Open-Loop Controls Based on the DSPI Model
Authors: An Dong , Li Ji , Li Songhua , Shao Meng , Wang Weinan , Wang Chuan , Yang Yixiao
Published: March 2023

Nanopositioning stages with piezoelectric actuators have been widely used in fields such as precision mechanical engineering, but the nonlinear start-up accuracy problem under open-loop control has still not been solved, and more errors will accumulate, especially under open-loop control. This paper first analyzes the causes of the starting errors from both the physical properties of materials and voltages: the starting errors are affected by the material properties of piezoelectric ceramics, and the magnitude of the voltage determines the magnitude of the starting errors. Then, this paper adopts an image-only model of the data separated by a Prandtl-Ishlinskii model (DSPI) based on the classical Prandtl-Ishlinskii model (CPI), which can improve the positioning accuracy of the nanopositioning platform after separating the data based on the start-up error characteristics. This model can improve the positioning accuracy of the nanopositioning platform while solving the problem of nonlinear start-up errors under open-loop control. Finally, the DSPI inverse model is used for the feedforward compensation control of the platform, and the experimental results show that the DSPI model can solve the nonlinear start-up error problem existing under open-loop control. The DSPI model not only has higher modeling accuracy than the CPI model but also has better performance in terms of compensation results. The DSPI model improves the localization accuracy by 99.427% compared to the CPI model. When compared with another improved model, the localization accuracy is improved by 92.763%.
Effect of Sedimentary Facies Characteristics on Deep Shale Gas Desserts: A Case from the Longmaxi Formation, South Sichuan Basin, China
Authors: Wang Meng , He Jiang , Liu Shu , Zeng Chunlin , Jia Song , Nie Zhou , Wang Shengxiu , Wang Wei , Zhang Chun
Published: March 2023

Shale gas is one of the hot spots of energy development. Due to the strong heterogeneity and low physical properties of shale gas reservoirs, and the complex influencing factors of pore development, it is necessary to conduct a comprehensive analysis of the control factors of high-quality reservoirs. The sedimentary characteristics, mineral composition, pore structure and controlling factors of high quality reservoir development are studied on the basis of thin section, scanning electron microscopy (SEM) and QEMSCAN analysis, X-ray diffraction (XRD), total organic carbon (TOC), Nano-CT scanning and Low-pressure N2 adsorption (N2GA) analysis on shale samples from the Longmaxi Formation in South Sichuan Basin. The results show the following: (1) According to lithology, sedimentary structure, organic carbon content and mineral composition, six sedimentary microfacies can be divided. (2) Organic matter pores are developed in organic-rich siliceous shale and organic-rich silty shale at the bottom of the first member of the Longmaxi formation, with average porosity of more than 5% and permeability of more than 2 × 10−3 μm2, which is conducive to the formation of high-quality shale gas reservoirs. (3) The contents of siliceous and TOC are positively correlated with porosity and specific surface area, while the contents of carbonate and clay minerals are negatively correlated with reservoir quality. (4) In the first member of the Longmaxi formation, the sedimentary water depth becomes shallower from bottom to top, and the sedimentary environment changes from a reduction to an oxidation environment. The contents of siliceous and organic matter decrease, while the contents of clay minerals and carbonate minerals show the opposite trend. The difference in sedimentary microfacies affects the distribution of mineral and organic matter and controls the heterogeneity of the shale reservoir.
Lavandula x intermedia—A Bastard Lavender or a Plant of Many Values? Part II. Biological Activities and Applications of Lavandin
Authors: Pokajewicz Katarzyna , Czarniecka-Wiera Marta , Krajewska Agnieszka , Maciejczyk Ewa , Wieczorek Piotr P.
Published: March 2023

This review article is the second in a series aimed at providing an in-depth overview of Lavandula x intermedia (lavandin). In part I, the biology and chemistry of lavandin were addressed. In part II, the focus is on the functional properties of lavandin and its applications in industry and daily life. While reviewing the biological properties, only original research articles employing lavandin were considered. Lavandin essential oil has been found to have antioxidant and biocidal activity (antimicrobial, nematicidal, antiprotozoal, insecticidal, and allelopathic), as well as other potential therapeutic effects such as anxiolytic, neuroprotective, improving sleep quality, antithrombotic, anti-inflammatory, and analgesic. Other lavandin preparations have been investigated to a much lesser extent. The research is either limited or inconsistent across all studies, and further evidence is needed to support these properties. Unlike its parent species—Lavandula angustifolia (LA)—lavandin essential oil is not officially recognized as a medicinal raw material in European Pharmacopeia. However, whenever compared to LA in shared studies, it has shown similar effects (or even more pronounced in the case of biocidal activities). This suggests that lavandin has similar potential for use in medicine.
Self-Assembled BODIPY Nanoparticles for Near-Infrared Fluorescence Bioimaging
Authors: Wang Jiale , Jiang Zhao , Huang Cheng , Zhao Shimao , Zhu Senqiang , Liu Rui , Zhu Hongjun
Published: March 2023

In vivo optical imaging is an important application value in disease diagnosis. However, near-infrared nanoprobes with excellent luminescent properties are still scarce. Herein, two boron–dipyrromethene (BODIPY) molecules (BDP-A and BDP-B) were designed and synthesized. The BODIPY emission was tuned to the near-infrared (NIR) region by regulating the electron-donating ability of the substituents on its core structure. In addition, the introduction of polyethylene glycol (PEG) chains on BODIPY enabled the formation of self-assembled nanoparticles (NPs) to form optical nanoprobes. The self-assembled BODIPY NPs present several advantages, including NIR emission, large Stokes shifts, and high fluorescence quantum efficiency, which can increase water dispersibility and signal-to-noise ratio to decrease the interference by the biological background fluorescence. The in vitro studies revealed that these NPs can enter tumor cells and illuminate the cytoplasm through fluorescence imaging. Then, BDP-B NPs were selected for use in vivo imaging due to their unique NIR emission. BDP-B was enriched in the tumor and effectively illuminated it via an enhanced penetrability and retention effect (EPR) after being injected into the tail vein of mice. The organic nanoparticles were metabolized through the liver and kidney. Thus, the BODIPY-based nanomicelles with NIR fluorescence emission provide an effective research basis for the development of optical nanoprobes in vivo.
Molecular Modelling Study and Antibacterial Evaluation of Diphenylmethane Derivatives as Potential FabI Inhibitors
Authors: Hasan Shaima , Kayed Kawthar , Ghemrawi Rose , Bataineh Nezar Al , Mahgoub Radwa E. , Audeh Rola , Aldulaymi Raghad , Atatreh Noor , Ghattas Mohammad A.
Published: March 2023

The need for new antibiotics has become a major worldwide challenge as bacterial strains keep developing resistance to the existing drugs at an alarming rate. Enoyl-acyl carrier protein reductases (FabI) play a crucial role in lipids and fatty acid biosynthesis, which are essential for the integrity of the bacterial cell membrane. Our study aimed to discover small FabI inhibitors in continuation to our previously found hit MN02. The process was initially started by conducting a similarity search to the NCI ligand database using MN02 as a query. Accordingly, ten compounds were chosen for the computational assessment and antimicrobial testing. Most of the compounds showed an antibacterial activity against Gram-positive strains, while RK10 exhibited broad-spectrum activity against both Gram-positive and Gram-negative bacteria. All tested compounds were then docked into the saFabI active site followed by 100 ns MD simulations (Molecular Dynamics) and MM-GBSA (Molecular Mechanics with Generalised Born and Surface Area Solvation) calculations in order to understand their fitting and estimate their binding energies. Interestingly, and in line with the experimental data, RK10 was able to exhibit the best fitting with the target catalytic pocket. To sum up, RK10 is a small compound with leadlike characteristics that can indeed act as a promising candidate for the future development of broad-spectrum antibacterial agents.
The SWGEDWGEIW from Soybean Peptides Reduces Insulin Resistance in 3T3-L1 Adipocytes by Activating p-Akt/GLUT4 Signaling Pathway
Authors: Yi Guofu , Sang Xia , Zhu Yuxia , Zhou Di , Yang Shuibing , Huo Yue , Liu Yang , Safdar Bushra , Bu Xianyong
Published: March 2023

Diabetes mellitus, a group of metabolic disorders characterized by persistent hyperglycemia, affects millions of people worldwide and is on the rise. Dietary proteins, from a wide range of food sources, are rich in bioactive peptides with anti-diabetic properties. Notably, the protective mechanism of the single peptide SWGEDWGEIW (TSP) from soybean peptides (SBPs) on insulin resistance of adipocytes in an inflammatory state was investigated by detecting the lipolysis and glucose absorption and utilization of adipocytes. The results showed that different concentrations of TSP (5, 10, 20 µg/mL) intervention can reduce 3T3-L1 adipocytes’ insulin resistance induced by inflammatory factors in a dose-dependent manner and increase glucose utilization by 34.2 ± 4.6%, 74.5 ± 5.2%, and 86.7 ± 6.1%, respectively. Thus, TSP can significantly alleviate the lipolysis of adipocytes caused by inflammatory factors. Further mechanism analysis found that inflammatory factors significantly reduced the phosphorylation (p-Akt) of Akt, two critical proteins of glucose metabolism in adipocytes, and the expression of GLUT4 protein downstream, resulting in impaired glucose utilization, while TSP intervention significantly increased the expression of these two proteins. After pretreatment of adipocytes with PI3K inhibitor (LY294002), TSP failed to reduce the inhibition of p-Akt and GLUT4 expression in adipocytes. Meanwhile, the corresponding significant decrease in glucose absorption and the increase in the fat decomposition of adipocytes indicated that TSP reduced 3T3-L1 adipocytes’ insulin resistance by specifically activating the p-Akt/GLUT4 signal pathway. Therefore, TSP has the potential to prevent obesity-induced adipose inflammation and insulin resistance.
Protective Effects of Omega-3 Supplementation against Doxorubicin-Induced Deleterious Effects on the Liver and Kidneys of Rats
Authors: Espírito Santo Sara Gomes , Monte Marina Gaiato , Polegato Bertha Furlan , Barbisan Luís Fernando , Romualdo Guilherme Ribeiro
Published: March 2023

Anthracycline doxorubicin (DOX) is still widely used as a chemotherapeutic drug for some solid tumors. Although DOX is highly effective, its side effects are limiting factors, such as cardio, nephro and hepatotoxicity. As such, approaches used to mitigate these adverse effects are highly encouraged. Omega 3 (ω-3), which is a class of long-chain polyunsaturated fatty acids, has been shown to have anti-inflammatory and antioxidant effects in preclinical bioassays. Thus, we evaluated the protective effects of ω-3 supplementation on hepatotoxicity and nephrotoxicity induced by multiple DOX administrations in rodents. Male Wistar rats (10 rats/group) were treated daily with ω-3 (400 mg/kg/day) by gavage for six weeks. Two weeks after the first ω-3 administration, the rats received DOX (3.5 mg/kg, intraperitoneal, 1×/week) for four weeks. DOX treatment reduced body weight gain increased systemic genotoxicity and caused liver-related (increase in serum ALT levels, thickness of the Glisson’s capsule, compensatory proliferation and p65 levels) and kidney-related (increase in serum urea and creatinine levels, and incidence of tubular dilatation) deleterious outcomes. In contrast, ω-3 supplementation was safe and abrogated the DOX-related enhancement of systemic genotoxicity, serum urea and creatinine levels. Furthermore, ω-3 intervention reduced by 50% the incidence of kidney histological lesions while reducing by 40–50% the p65 protein level, and the proliferative response in the liver induced by DOX. Our findings indicate that ω-3 intervention attenuated the DOX-induced deleterious effects in the liver and kidney. Therefore, our findings may inspire future mechanistical investigations and clinical interventions with ω-3 on the reported outcomes.
A Brief Review on the Synthesis of the N-CF3 Motif in Heterocycles
Authors: Lei Zizhen , Chang Wenxu , Guo Hong , Feng Jiyao , Zhang Zhenhua
Published: March 2023

The trifluoromethyl group is widely recognized for its significant role in the fields of medicinal chemistry and material science due to its unique electronic and steric properties that can alter various physiochemical properties of the parent molecule, such as lipophilicity, acidity, and hydrogen bonding capabilities. Compared to the well-established C-trifluoromethylation, N-trifluoromethylation has received lesser attention. Considering the extensive contribution of nitrogen to drug molecules, it is predicted that constructing N-trifluoromethyl (N-CF3) motifs will be of great significance in pharmaceutical and agrochemical industries. This review is mainly concerned with the synthesis of heterocycles containing this motif. In three-membered heterocycles containing the N-CF3 motif, the existing literature mostly demonstrated the synthetic strategy, as it does for four- and larger-membered heterocycles. Certain structures, such as oxaziridines, could serve as an oxidant or building blocks in organic synthesis. In five-membered heterocycles, it has been reported that N-CF3 azoles showed a higher lipophilicity and a latent increased metabolic stability and Caco-2-permeability compared with their N-CH3 counterparts, illustrating the potential of the N-CF3 motif. Various N-CF3 analogues of drugs or bioactive molecules, such as sildenafil analogue, have been obtained. In general, the N-CF3 motif is developing and has great potential in bioactive molecules or materials. Give the recent development in this motif, it is foreseeable that its synthesis methods and applications will become more and more extensive. In this paper, we present an overview of the synthesis of N-CF3 heterocycles, categorized on the basis of the number of rings (three-, four-, five-, six- and larger-membered heterocycles), and focus on the five-membered heterocycles containing the N-CF3 group.