bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Insights into the Pathogenesis of Acute Porphyria Attacks and Increasing Hepatic PBGD as an Etiological Treatment
Authors: Jericó Daniel , Córdoba Karol M. , Sampedro Ana , Jiang Lei , Joucla Gilles , Cabanne Charlotte , Lanciego José Luis , Martini Paolo G. V. , Berraondo Pedro , Ávila Matías A. , Fontanellas Antonio
Published: November 2022

Rare diseases, especially monogenic diseases, which usually affect a single target protein, have attracted growing interest in drug research by encouraging pharmaceutical companies to design and develop therapeutic products to be tested in the clinical arena. Acute intermittent porphyria (AIP) is one of these rare diseases. AIP is characterized by haploinsufficiency in the third enzyme of the heme biosynthesis pathway. Identification of the liver as the target organ and a detailed molecular characterization have enabled the development and approval of several therapies to manage this disease, such as glucose infusions, heme replenishment, and, more recently, an siRNA strategy that aims to down-regulate the key limiting enzyme of heme synthesis. Given the involvement of hepatic hemoproteins in essential metabolic functions, important questions regarding energy supply, antioxidant and detoxifying responses, and glucose homeostasis remain to be elucidated. This review reports recent insights into the pathogenesis of acute attacks and provides an update on emerging treatments aimed at increasing the activity of the deficient enzyme in the liver and restoring the physiological regulation of the pathway. While further studies are needed to optimize gene therapy vectors or large-scale production of liver-targeted PBGD proteins, effective protection of PBGD mRNA against the acute attacks has already been successfully confirmed in mice and large animals, and mRNA transfer technology is being tested in several clinical trials for metabolic diseases.
Spatial Heterogeneity of Soil Bacterial Community Structure and Enzyme Activity along an Altitude Gradient in the Fanjingshan Area, Northeastern Guizhou Province, China
Authors: Xie Yuangui , Zhang Lanyue , Wang Juncai , Chen Meng , Liu Jiming , Xiao Shengyang , Tian Xiu , Wu Tingting
Published: November 2022

Changes in altitude can cause regional microclimate changes, leading to the spatial heterogeneity of environmental factors and soil bacteria. However, the internal driving process and mechanism remain unclear. Here, we selected Fanjingshan, a typical nature reserve in the subtropical region of south China with a clear altitudinal belt, to reveal the response mechanisms of microbial populations with altitude changes. We examined the physiochemical and biological properties (pH and soil enzyme activities) of 0~10 cm soil layers, soil bacterial diversity, and community structure across the 2.1 km belt (consisting of six altitude ranges). Our results showed that soil pH was highest at the altitude range below 900 m and decreased with altitude thereafter. Soil enzyme activities showed an overall decreasing trend with altitude rising. The soil sucrase and catalase activity was highest (48.35 mg.g−1.d−1 and 23.75 µmol.g−1, respectively) at altitudes below 900 m; the soil urease activity was highest (704.24 µg.g−1.d−1) at 900~1200 m; and the soil acid phosphatase activity was highest (57.18 µmol.g−1) at 1200~1500 m. In addition, the soil bacterial community diversity showed a linear increasing trend, with the maximum abundance at 1500~1800 m. Soil pH was correlated with enzyme activity and bacterial community composition and structure, and the correlation was the strongest between pH and the distribution of bacterial diversity at altitudes below 900 m. Overall, soil enzyme activities and soil bacterial diversity showed spatial heterogeneity along the altitude gradient, and their community structure and composition were affected by altitude as a result of changes in soil physicochemical factors. This study provides a better and deeper understanding of the spatial succession of soil in the Fanjingshan area and the distribution pattern of soil microorganisms in central subtropical mountain ecosystems.
Injectable Cell-Laden Nanofibrous Matrix for Treating Annulus Fibrosus Defects in Porcine Model: An Organ Culture Study
Authors: Roebke Evan , Jacho Diego , Eby Oliver , Aldoohan Sulaiman , Elsamaloty Haitham , Yildirim-Ayan Eda
Published: November 2022

Lower back pain commonly arises from intervertebral disc (IVD) failure, often caused by deteriorating annulus fibrosus (AF) and/or nucleus pulposus (NP) tissue. High socioeconomic cost, quality of life issues, and unsatisfactory surgical options motivate the rapid development of non-invasive, regenerative repair strategies for lower back pain. This study aims to evaluate the AF regenerative capacity of injectable matrix repair strategy in ex vivo porcine organ culturing using collagen type-I and polycaprolactone nanofibers (PNCOL) with encapsulated fibroblast cells. Upon 14 days organ culturing, the porcine IVDs were assessed using gross optical imaging, magnetic resonance imaging (MRI), histological analysis, and Reverse Transcriptase quantitative PCR (RT-qPCR) to determine the regenerative capabilities of the PNCOL matrix at the AF injury. PNCOL-treated AF defects demonstrated a full recovery with increased gene expressions of AF extracellular matrix markers, including Collagen-I, Aggrecan, Scleraxis, and Tenascin, along with anti-inflammatory markers such as CD206 and IL10. The PNCOL treatment effectively regenerates the AF tissue at the injury site contributing to decreased herniation risk and improved surgical outcomes, thus providing effective non-invasive strategies for treating IVD injuries.
Maternal Gestational Diabetes Influences DNA Methylation in the Serotonin System in the Human Placenta
Authors: Song Jae Yen , Lee Kyung Eun , Byeon Eun Jeong , Choi Jieun , Kim Sa Jin , Shin Jae Eun
Published: November 2022

The offspring of mothers with gestational diabetes mellitus (GDM) are at a higher risk for metabolic dysregulation and neurodevelopmental impairment. Evidence suggests that serotonin, which is present in both the placenta and the brain, programs the development and growth of the fetal brain. In the current study, we tested the hypothesis that GDM affects the methylation of the serotonin transporter gene (SLC6A4) and serotonin receptor gene (HTR2A) in the placenta. Ninety pregnant women were included in this study. Thirty mothers were diagnosed with GDM, and sixty mothers served as controls in a 1:2 ratio. Ten CpG sites within the promoter regions of SLC6A4 and HTR2A were analyzed using pyrosequencing. The relative expression of genes involved in DNA methylation was evaluated using real-time PCR. The average DNA methylation of placental SLC6A4 was higher in the GDM group than in the control group (2.29 vs. 1.16%, p < 0.001). However, the average DNA methylation level of HTR2A did not differ between the two groups. SLC6A4 methylation showed a positive correlation with maternal plasma glucose level and neonatal birth weight percentile and a negative correlation with the neonatal head circumference percentile. This finding suggests that epigenetic modification of the placental serotonin system may affect placental adaptation to a harmful maternal environment, thereby influencing the long-term outcome in the offspring.
The State of Dark Coniferous Forests on the East European Plain Due to Climate Change
Authors: Vedernikov Konstantin E. , Bukharina Irina L. , Udalov Denis N. , Pashkova Anna S. , Larionov Maxim V. , Mazina Svetlana E. , Galieva Adelina R.
Published: November 2022

As a result of global climate changes, negative processes have been recorded in the coniferous forests of the Northern Hemisphere. Similar processes are observed in the Urals, including in Udmurtia. In the course of this research, archival analysis methods were used, as well as field research methods. In the process of analyzing archival materials in the Urals, a reduction of spruce forests was observed. If in the 20th century the share of spruce forests in the region was 50%, then in the 21th century it decreased to 35%. As a result of this research, it was revealed that the most unfavorable sanitary condition was recorded in the boreal–subboreal zone of Udmurtia, with a sanitary condition index of 3.2 (from 2.62 to 3.73). The main reason for the unfavorable sanitary condition of spruce forests was the vital activity of Ips typographus L. According to our research, in 11 sample plots out of 18, a high score for sanitary condition was associated with the vital activity of bark beetles. The correlation coefficient of the index of the sanitary condition of plantings and the number of individuals of Picea obovata Ledeb. affected by Ips typographus L. was0.93. Bark beetle activity has increased in the 21th century, which is associated with changing climatic factors. Unstable precipitation over recent years (differences of more than 100 mm) and an average temperature increase of 1.2 °C were observed in the region. The most significant increase in temperature over the past 10 years was observed in winter, which in turn affected the high survival rate of insect pests.
The Partial Derivative Method for Dynamic Stiffness and Damping Coefficients of Supercritical CO2 Foil Bearings
Authors: Han Dongjiang , Bi Chunxiao
Published: November 2022

Supercritical CO2 foil bearings are promising bearing technology for supercritical CO2 high-speed turbomachinery. The partial derivative method including complete variable perturbation of the compressible turbulent lubrication Reynolds equation is effective to predict the frequency dependent dynamic stiffness and damping coefficients of supercritical CO2 bearings. In this research, the structural perturbation of foil dynamic model was introduced into this method and then the dynamic coefficients of supercritical CO2 foil bearings were calculated. The results of parametric analysis show that the structural loss factor has little influence on the trend of dynamic coefficients changing with the dimensionless support stiffness but mainly affects the value of stiffness coefficients as well as damping coefficients. Due to the turbulence effect, the bearing number is not able to directly determine the characteristics of supercritical CO2 foil bearings, which is different from air bearings. Compared to the bearing number, the influence of the average Reynolds number on the change of dynamic coefficients with dimensionless support stiffness is more obvious.
Methyl 5-(2-Fluoro-4-nitrophenyl)furan-2-carboxylate
Authors: Mori Matteo , Tresoldi Andrea , Cazzaniga Giulia , Meneghetti Fiorella , Villa Stefania
Published: November 2022

5-Phenyl-furan-2-carboxylic acids have emerged as a new, promising class of antimycobacterial agents that have the ability to interfere with iron homeostasis. Considering the lack of structural data on these compounds, we analyzed the crystal of a fluorinated ester derivative of 5-(4-nitrophenyl)furan-2-carboxylic acid, one of the most potent candidates in the series. Here, we describe the preparation of methyl 5-(2-fluoro-4-nitrophenyl)furan-2-carboxylate (1) and its analysis by 1H-NMR, 13C-NMR, HRMS, and SC-XRD.
Extraction Optimization and Structural Characteristics of Chitosan from Cuttlefish (S. pharaonis sp.) Bone
Authors: Hazeena Sulfath Hakkim , Hou Chih-Yao , Zeng Jing-Huei , Li Bo-Heng , Lin Tzu-Chih , Liu Cai-Sian , Chang Chi-I , Hsieh Shu-Ling , Shih Ming-Kuei
Published: November 2022

In fish processing, reducing the waste rate and increasing the economic value of products is an important issue for global environmental protection and resource sustainability. It has been discovered that cuttlefish bones can be an excellent resource for producing attractive amounts of chitin and chitosan. Therefore, this study optimized chitosan extraction conditions using response surface methodology (RSM) to establish application conditions suitable for industrial production and reducing environmental impact. In addition, Fourier-transform infrared spectroscopy (FTIR), 1H NMR and scanning electron microscope (SEM) characteristics of extracted chitosan were evaluated. The optimum extraction conditions for chitosan from cuttlebone chitin were 12.5M NaOH, 6 h and 80 °C, and the highest average yield was 56.47%. FTIR spectroscopy, 1H NMR, and SEM identification proved that the chitosan prepared from cuttlefish bone has a unique molecular structure, and the degree of deacetylation of chitosan was about 81.3%. In addition, it was also confirmed that chitosan has significant anti-oxidation and oil-absorbing abilities. This research has successfully transformed the by-products of cuttlefish processing into value-added products. The process not only achieved the recycling and utilization of by-products but also enhanced industrial competitiveness and resource sustainability.
CeFeO3–CeO2–Fe2O3 Systems: Synthesis by Solution Combustion Method and Catalytic Performance in CO2 Hydrogenation
Authors: Matveyeva Anna N. , Omarov Shamil O. , Gavrilova Marianna A. , Sladkovskiy Dmitry A. , Murzin Dmitry Yu.
Published: November 2022

Rare-earth orthoferrites have found wide application in thermocatalytic reduction-oxidation processes. Much less attention has been paid, however, to the production of CeFeO3, as well as to the study of its physicochemical and catalytic properties, in particular, in the promising process of CO2 utilization by hydrogenation to CO and hydrocarbons. This study presents the results of a study on the synthesis of CeFeO3 by solution combustion synthesis (SCS) using various fuels, fuel-to-oxidizer ratios, and additives. The SCS products were characterized by XRD, FTIR, N2-physisorption, SEM, DTA–TGA, and H2-TPR. It has been established that glycine provides the best yield of CeFeO3, while the addition of NH4NO3 promotes an increase in the amount of CeFeO3 by 7–12 wt%. In addition, the synthesis of CeFeO3 with the participation of NH4NO3 makes it possible to surpass the activity of the CeO2–Fe2O3 system at low temperatures (300–400 °C), as well as to increase selectivity to hydrocarbons. The observed effects are due to the increased gas evolution and ejection of reactive FeOx nanoparticles on the surface of crystallites, and an increase in the surface defects. CeFeO3 obtained in this study allows for achieving higher CO2 conversion compared to LaFeO3 at 600 °C.
Modulated Laser Cladding of Implant-Type Coatings by Bovine-Bone-Derived Hydroxyapatite Powder Injection on Ti6Al4V Substrates—Part I: Fabrication and Physico-Chemical Characterization
Authors: Mocanu Aura-Cătălina , Miculescu Florin , Stan George E. , Pasuk Iuliana , Tite Teddy , Pascu Alexandru , Butte Tudor Mihai , Ciocan Lucian-Toma
Published: November 2022

The surface physico-chemistry of metallic implants governs their successful long-term functionality for orthopedic and dentistry applications. Here, we investigated the feasibility of harmoniously combining two of the star materials currently employed in bone treatment/restoration, namely, calcium-phosphate-based bioceramics (in the form of coatings that have the capacity to enhance osseointegration) and titanium alloys (used as bulk implant materials due to their mechanical performance and lack of systemic toxicity). For the first time, bovine-bone-derived hydroxyapatite (BHA) was layered on top of Ti6Al4V substrates using powder injection laser cladding technology, and then subjected, in this first stage of the research, to an array of physical-chemical analyses. The laser processing set-up involved the conjoined modulation of the BHA-to-Ti ratio (100 wt.% and 50 wt.%) and beam power range (500–1000 W). As such, on each metallic substrate, several overlapped strips were produced and the external surface of the cladded coatings was further investigated. The morphological and compositional (SEM/EDS) evaluations exposed fully covered metallic surfaces with ceramic-based materials, without any fragmentation and with a strong metallurgical bond. The structural (XRD, micro-Raman) analyses showed the formation of calcium titanate as the main phase up to maximum 800 W, accompanied by partial BHA decomposition and the consequential advent of tetracalcium phosphate (markedly above 600 W), independent of the BHA ratio. In addition, the hydrophilic behavior of the coatings was outlined, being linked to the varied surface textures and phase dynamism that emerged due to laser power increment for both of the employed BHA ratios. Hence, this research delineates a series of optimal laser cladding technological parameters for the adequate deposition of bioceramic layers with customized functionality.
The Effect of Changes in the Separation Process for the Performance of Recycled Cement Powder: A Comparison with a Previous Study for Radioactive Waste Immobilization
Authors: Kim Ji-Hyun , Seo Eun-A , Kim Do-Gyeum , Chung Chul-Woo
Published: November 2022

Separation of hydrated cement paste from aggregate is a key technology to reduce the amount of radioactive concrete waste during the decommissioning process. If separated cement-paste portions can be recycled as a solidifying agent for other radioactive waste, the amount of radioactive concrete waste could be close to “zero”. A study was conducted to achieve circular economy in the area of concrete decommissioning and found it to be successfully used as a solidifying agent for immobilization of liquid radioactive waste. However, previous work used a process that requires large amounts of energy (heat treatment was applied to most of the concrete fraction) because the objective was to completely remove hydrated cement powder from the aggregate. In this work, the separation system was modified to increase energy efficiency (heat treatment was applied to separated powder only), but such a change decreased the surface area of the recycled cement powder due to a higher inclusion of aggregate powder. A relatively lower solution to binder ratio could have been achieved for the preparation of wasteform specimens, and as a result, a 28 day compressive strength of wasteform could have become higher, but the final leachability indices were lower than the results observed from previous work. The results from 28 day compressive strength, thermal cycling and 90 day leaching experiments met the acceptance criteria for wasteform, indicating that this modified system can also be used for immobilization of liquid radioactive waste to meet the “zero” production of concrete waste during the decommissioning of a nuclear power plant. It should be noted that accurate monitoring of aggregate content in recycled cement powder during production is important to maintain proper reactivity of recycled cement powder.
Study on the Densification of Osmium by Experiment and First Principle Calculations
Authors: Yang Yunfei , Sun Junhao , Liu Wei , Hu Peng , Zhang Ruimin , Liu Hexiong , Gao Junyan , Wang Jinshu
Published: November 2022

The sintering of osmium is critical for the preparation of raw material targets for film coating, which is the main application area of osmium. In order to get a better understanding of the intrinsic mechanism of densification of osmium, a serial study on the sintering behavior of osmium has been made in this study. By the master sintering curve (MSC) and constant heating rate (CHR) method, the sintering activation energy of nanosized osmium is evaluated to be about 340 kJ/mol, which is higher than most other metals. The density–functional theory calculation indicates the higher energy barrier of the surface atom and vacancy migration and lacking migration tunnel of inner point vacancies. For example, the diffusion of osmium atoms on the surface of particles is mainly limited by Os (1010), which has an energy barrier as high as 1.14 eV, that is higher than the W atom on W (110) of 0.99 eV. The vacancy migration energy barrier inside osmium’s grains is higher than 3.0 eV, while that of W is only 1.7 eV. This means that it is more difficult for osmium to achieve a high density compared with W, which is consistent with the experimental results. Accordingly, the proposed strategy provides a new opportunity to design a sintering process for target fabrication with excellent properties for various applications.
Special Issue: “Structural and Thermal Properties of Polymeric Microspheres”
Authors: Maciejewska Małgorzata
Published: November 2022

In recent years, polymeric materials have become the backbone of modern industry and technology [...]
Current Harmonic Suppression of BLDC Motor Utilizing Frequency Adaptive Repetitive Controller
Authors: Yuan Tianqing , Zhang Yupeng
Published: November 2022

Compared to the proportional-integral strategy, the repetitive control strategy possesses high suppression ability for the alternating current (AC) harmonics of control signals. Thus, RC controllers are widely used in closed-loop control systems to suppress the periodic harmonics. In order to further improve the brushless DC (BLDC) motor operation performance, a frequency adaptive repetitive controller (FARC) is proposed, and then a novel current loop scheme that concatenation of proportional-integral controller (PIC) and FARC controller is established in this paper. Firstly, due to the real sampling number of the delay element in the BLDC, the motor control system may not be an integer, the designing process of the FARC parameters was studied, and an adaptive internal model controller and a novel decomposition rule for FARC were designed based on Lagrange interpolation theory. Secondly, the PIC parameters were analyzed through three-dimensional and two-dimensional images of the frequency characteristics. Furthermore, a composite controller that added a forward channel in the novel current loop was proposed, and the stability of the control system used the composite controller was analyzed through Lyapunov theory. It should be noted that the analysis of FARC mainly focused on the simplified structure and the parameter optimization, which is usually ignored in the previous studies. Finally, the BLDC motor control system model was established through Matlab/Simulink software, and the operation performances of the BLDC motor control system utilizing different current loop controllers were studied. The simulation results show that the proposed FARC can reduce current distortion and torque ripples, thus, the BLDC motor operation performances can be improved effectively.
Interface Effects on Magnetic Anisotropy and Domain Wall Depinning Fields in Pt/Co/AlOx Thin Films
Authors: Sankhi Babu Ram , Lamichhane Ujjal , Mandal Soumya , Sachan Ritesh , Turgut Emrah , Meyers Derek
Published: November 2022

We report the dependence of the domain wall depinning field, domain wall velocity, including anisotropy direction, and magnetic properties on the oxidized aluminum thickness of perpendicularly magnetized asymmetric Pt/Co/AlOx trilayers. We also adopt the low-temperature magneto-transport measurement technique to investigate the amount of oxygen at the Co/AlOx interface of our magnetic thin films. At the lowest temperature of 25 K, it is found that the coercivity for the 5 nm aluminum thickness sample is very close to the average value and coercivity diminished above and below this critical aluminum thickness, hinting at a large variation in CoOx content at the interface. This tendency is also consistent with the modification of the depinning fields, coercive fields, and surface roughness measured at room temperature. Our results highlight an efficient way of controlling the depinning fields and other magnetic characteristics, which is important for stabilizing and driving magnetic spin textures and applicable to energy-efficient next-generation spintronics devices.
Reprojection-Based Numerical Measure of Robustness for CT Reconstruction Neural Network Algorithms
Authors: Smolin Aleksandr , Yamaev Andrei , Ingacheva Anastasia , Shevtsova Tatyana , Polevoy Dmitriy , Chukalina Marina , Nikolaev Dmitry , Arlazarov Vladimir
Published: November 2022

In computed tomography, state-of-the-art reconstruction is based on neural network (NN) algorithms. However, NN reconstruction algorithms can be not robust to small noise-like perturbations in the input signal. A not robust NN algorithm can produce inaccurate reconstruction with plausible artifacts that cannot be detected. Hence, the robustness of NN algorithms should be investigated and evaluated. There have been several attempts to construct the numerical metrics of the NN reconstruction algorithms’ robustness. However, these metrics estimate only the probability of the easily distinguishable artifacts occurring in the reconstruction. However, these methods measure only the probability of appearance of easily distinguishable artifacts on the reconstruction, which cannot lead to misdiagnosis in clinical applications. In this work, we propose a new method for numerical estimation of the robustness of the NN reconstruction algorithms. This method is based on the probability evaluation for NN to form such selected additional structures during reconstruction which may lead to an incorrect diagnosis. The method outputs a numerical score value from 0 to 1 that can be used when benchmarking the robustness of different reconstruction algorithms. We employed the proposed method to perform a comparative study of seven reconstruction algorithms, including five NN-based and two classical. The ResUNet network had the best robustness score (0.65) among the investigated NN algorithms, but its robustness score is still lower than that of the classical algorithm SIRT (0.989). The investigated NN models demonstrated a wide range of robustness scores (0.38–0.65). Thus, in this work, robustness of 7 reconstruction algorithms was measured using the new proposed score and it was shown that some of the neural algorithms are not robust.
A Novel MCDM Approach Based on OPA-WINGS for Policy Making in Undergraduate Elective Courses
Authors: Hashemkhani Zolfani Sarfaraz , Nemati Alireza , Reyes-Norambuena Pedro J. , Monardes-Concha Carlos A.
Published: November 2022

This research develops a novel MCDM approach that combines the ordinal priority approach (OPA) and a weighted influence nonlinear gauge system (WINGS), for policy making about undergraduate programs and specifically elective courses. We interviewed eight professors at the School of Engineering, Universidad Catolica del Norte, who are highly engaged in organizing elective courses to obtain their prioritization criteria for offering them to undergraduate students. We proposed and applied an MCDM approach based on OPA-WINGS to rank criteria that make the process of planning future electives courses to offer more straightforward. We found that scientific thinking, Industries’ needs, and the School’s research lines are the main criteria for designing a new elective class. We conducted a sensitivity analysis to demonstrate de robustness of the suggested measures. This work illustrates how OPA-WINGS can improve decision-making for offering elective courses. The results indicate that Industries’ needs and School’s research lines strongly impact undergraduate programs’ direction.
Camouflage Object Segmentation Using an Optimized Deep-Learning Approach
Authors: Kamran Muhammad , Rehman Saeed Ur , Meraj Talha , Alnowibet Khalid A. , Rauf Hafiz Tayyab
Published: November 2022

Camouflage objects hide information physically based on the feature matching of the texture or boundary line within the background. Texture matching and similarities between the camouflage objects and surrounding maps make differentiation difficult with generic and salient objects, thus making camouflage object detection (COD) more challenging. The existing techniques perform well. However, the challenging nature of camouflage objects demands more accuracy in detection and segmentation. To overcome this challenge, an optimized modular framework for COD tasks, named Optimize Global Refinement (OGR), is presented. This framework comprises a parallelism approach in feature extraction for the enhancement of learned parameters and globally refined feature maps for the abstraction of all intuitive feature sets at each extraction block’s outcome. Additionally, an optimized local best feature node-based rule is proposed to reduce the complexity of the proposed model. In light of the baseline experiments, OGR was applied and evaluated on a benchmark. The publicly available datasets were outperformed by achieving state-of-the-art structural similarity of 94%, 93%, and 96% for the Kvasir-SEG, COD10K, and Camouflaged Object (CAMO) datasets, respectively. The OGR is generalized and can be integrated into real-time applications for future development.
An Enhanced U-Net Approach for Segmentation of Aeroengine Hollow Turbine Blade
Authors: Zheng Jia , Tang Chuan , Sun Yuanxi , Feng Mingchi , Wang Congzhe
Published: November 2022

The hollow turbine blade plays an important role in the propulsion of the aeroengine. However, due to its complex hollow structure and nickel-based superalloys material property, only industrial computed tomography (ICT) could realize its nondestructive detection with sufficient intuitiveness. The ICT detection precision mainly depends on the segmentation accuracy of target ICT images. However, because the hollow turbine blade is made of special superalloys and contains many small unique structures such as film cooling holes, exhaust edges, etc., the ICT image quality of the hollow turbine blades is often deficient, with artifacts, low contrast, and inhomogeneity scattered around the blade contour, making it hard for traditional mathematical model-based methods to acquire satisfying segmentation precision. Therefore, this paper presents a deep learning-based approach, i.e., the enhanced U-net with multiscale inputs, dense blocks, focal loss function, and residual path in the skip connection to realize the high-precision segmentation of the hollow turbine blade. The experimental results show that our proposed enhanced U-net can achieve better segmentation accuracy for practical turbine blades than conventional U-net and traditional mathematical model-based methods.
Double Auction Offloading for Energy and Cost Efficient Wireless Networks
Authors: Bousia Alexandra , Daskalopulu Aspassia , Papageorgiou Elpiniki I.
Published: November 2022

Network infrastructure sharing and mobile traffic offloading are promising technologies for Heterogeneous Networks (HetNets) to provide energy and cost effective services. In order to decrease the energy requirements and the capital and operational expenditures, Mobile Network Operators (MNOs) and third parties cooperate dynamically with changing roles leading to a novel market model, where innovative challenges are introduced. In this paper, a novel resource sharing and offloading algorithm is introduced based on a double auction mechanism where MNOs and third parties buy and sell capacity and roam their traffic among each other. For low traffic periods, Base Stations (BSs) and Small Cells (SCs) can even be switched off in order to gain even more in energy and cost. Due to the complexity of the scenario, we adopt the multi-objective optimization theory to capture the conflicting interests of the participating entities and we design an iterative double auction algorithm that ensures the efficient operation of the market. Additionally, the selection of the appropriate time periods to apply the proposed algorithm is of great importance. Thus, we propose a machine learning technique for traffic load prediction and for the selection of the most effective time periods to offload traffic and switch off the Base Stations. Analytical and experimental results are presented to assess the performance of the algorithm.
Recurrent Shoulder Instability after Arthroscopic Bankart Repair in an Elite Baseball Pitcher—A Case Report
Authors: Kao Jo-Ting , Yang Cheng-Pang , Sheu Huan , Tang Hao-Che , Chan Yi-Sheng , Chen Alvin Chao-Yu , Hsu Kuo-Yao , Weng Chun-Jui , Cheng You-Hung , Chiu Chih-Hao
Published: November 2022

A 16-year-old right-handed male pitcher had a first-time right anterior shoulder dislocation during a baseball game. X-ray and MRI revealed no apparent glenoid bone loss or Hill-Sachs lesion, but an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion with mild posterolateral decompression of the humerus head. His instability severity index score (ISIS score) was 5 with an on-track lesion. He had an arthroscopic Bankart repair using two all-suture anchors and returned to pitching 6 months after the index surgery. However, he had an unstable sensation after 50 pitches during a game one year postoperatively. This time, he presented with a significant Hill–Sachs lesion and a recurrent APLSA lesion. His ISIS score was 6 with an on-tract lesion. During the arthroscopic examination, the previous suture was stable, while anterior capsuloligament tissues were dislodged from sutures, and a Hill–Sachs lesion was observed. This time, a revision arthroscopic Bankart repair and Remplissage procedure were done on him with four double-loaded soft tissue anchors. Pitchers often develop more external rotation in their throwing arm because of a repetitive stretch of the anterior shoulder capsule and ligaments during pitching. The decrease in external rotation after surgery may limit the pitching speed of the pitcher, making a return to play (RTP) more difficult. There is still a paucity of best evidence to revise a failed arthroscopic Bankart repair in the dominant arm of a pitcher. Arthroscopic Bankart repair and Remplissage procedure have gained increasing popularity because they can provide a stable shoulder without harvesting the coracoid. The Latarjet procedure provides a high RTP rate; however, we did not perform it in the revision surgery and decided to revise the Bankart lesion again on its own with a Remplissage procedure, even with his ISIS score being 6 before the revision surgery. A salvage Latarjet procedure is left as a bailout procedure.
Ovarian Sertoli Cell Tumor with Immature Prepubertal-like Sertoli Cell Component: A Case Report and Literature Review
Authors: Bužinskienė Diana , Šidlovska Evelina , Vilutytė Gabija
Published: November 2022

The Sertoli cell tumor of the ovary is a rare ovarian tumor with non-specific symptoms. According to the literature, endocrine manifestations occur in two-thirds of patients, but testosterone production is extremely rare. Typically, it is a unilateral benign tumor of the ovary that most commonly presents in adolescents and young women of childbearing potential. We report a 29-year-old patient, previously diagnosed to have polycystic ovarian syndrome, who presented with complaints of amenorrhea for the past three years. A transvaginal ultrasound scan revealed polycystic structure ovaries and a solid cystic formation of 32 × 31 mm size with strong blood flow in the left ovary. The laboratory tests reported an elevated testosterone level. During laparoscopic surgery, a solid, yellowish tumor was removed and the left ovary was resected. Histological examination revealed a left ovary Sertoli cell tumor with an immature prepubertal-like Sertoli cell component. Following surgery, the serum testosterone levels returned to normal and the menstrual cycle became regular. Due to the substantially low incidence of ovarian Sertoli cell tumors, information on their clinical behavior, morphologic spectrum, optimal management, and prognosis is limited. They are characterized by a wide variety of clinical manifestations, treated surgically, and, if diagnosed at an early stage, have good prognosis. We emphasize the extraordinarily rare clinical presentation of this case report.
Red Blood Cell Membrane Cholesterol May Be a Key Regulator of Sickle Cell Disease Microvascular Complications
Authors: Niesor Eric J. , Nader Elie , Perez Anne , Lamour François , Benghozi Renée , Remaley Alan , Thein Swee Lay , Connes Philippe
Published: November 2022

Cell membrane lipid composition, especially cholesterol, affects many functions of embedded enzymes, transporters and receptors in red blood cells (RBC). High membrane cholesterol content affects the RBCs’ main vital function, O2 and CO2 transport and delivery, with consequences on peripheral tissue physiology and pathology. A high degree of deformability of RBCs is required to accommodate the size of micro-vessels with diameters significantly lower than RBCs. The potential therapeutic role of high-density lipoproteins (HDL) in the removal of cholesterol and its activity regarding maintenance of an optimal concentration of RBC membrane cholesterol have not been well investigated. On the contrary, the focus for HDL research has mainly been on the clearance of cholesterol accumulated in atherosclerotic macrophages and plaques. Since all interventions aiming at decreasing cardiovascular diseases by increasing the plasma level of HDL cholesterol have failed so far in large outcome studies, we reviewed the potential role of HDL to remove excess membrane cholesterol from RBC, especially in sickle cell disease (SCD). Indeed, abundant literature supports a consistent decrease in cholesterol transported by all plasma lipoproteins in SCD, in addition to HDL, low- (LDL) and very low-density lipoproteins (VLDL). Unexpectedly, these decreases in plasma were associated with an increase in RBC membrane cholesterol. The concentration and activity of the main enzyme involved in the removal of cholesterol and generation of large HDL particles—lecithin cholesterol ester transferase (LCAT)—are also significantly decreased in SCD. These observations might partially explain the decrease in RBC deformability, diminished gas exchange and tendency of RBCs to aggregate in SCD. We showed that incubation of RBC from SCD patients with human HDL or the HDL-mimetic peptide Fx5A improves the impaired RBC deformability and decreases intracellular reactive oxygen species levels. We propose that the main physiological role of HDL is to regulate the cholesterol/phospholipid ratio (C/PL), which is fundamental to the transport of oxygen and its delivery to peripheral tissues.
Electric Potential Profiles in a Model Single-Path Electrodialysis Unit
Authors: Pagáč Jan , Kovář Petr , Slouka Zdeněk
Published: November 2022

Electrodialysis is an important electromembrane separation process anticipated to play a significant role in developing future technologies. It produces ion-depleted and ion-concentrated product streams, intrinsically suggesting the formation of spatial gradients of relevant quantities. These quantities affect local conditions in an electrodialysis unit. To investigate the spatial distribution of electric potentials, we constructed a model electrodialysis system with a single diluate channel that included ports for inserting reference electrodes measuring potential profiles. We validated our system and measurement methods in a series of control experiments under a solution flow rate of 250 µL/min and current densities between 10 and 52 A/m2. The collected data showed that the electric potential in the diluate channel did not change in the vertical direction (direction of gravity force), and only minimally varied in the diluate channel center in the flow direction. Although we could not reconstruct the potential profile within ion-depleted layers due to the resolution of the method, we found appreciable potential variation across the diluate channel. The most significant potential drops were localized on the membranes with the developed ion-depleted zones. Interestingly, these potential drops abruptly increased when we applied current loads, yielding almost complete desalination. The increase in the resistance accompanied by relatively large fluctuations in the measured potential indicated the system transition into limiting and overlimiting regions, and the onset of overlimiting convection.
Open Pore Ultrafiltration Hollow Fiber Membrane Fabrication Method via Dual Pore Former with Dual Dope Solution Phase
Authors: Jang Kyunghoon , Nguyen Thanh-Tin , Yi Eunsung , Kim Chang Seong , Kim Soo Wan , Kim In S.
Published: November 2022

Hollow-fiber membranes are widely used in various fields of membrane processes because of their numerous properties, e.g., large surface area, high packing density, mass production with uniform quality, obvious end-of-life indicators, and so on. However, it is difficult to control the pores and internal properties of hollow-fiber membranes due to their inherent structure: a hollow inside surrounded by a wall membrane. Herein, we aimed to control pores and the internal structure of hollow-fiber membranes by fabricating a dual layer using a dual nozzle. Two different pore formers, polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP), were separately prepared in the dope solutions and used for spinning the dual layer. Our results show that nanoscale pores could be formed on the lumen side (26.8–33.2 nm), and the open pores continuously increased in size toward the shell side. Due to robust pore structure, our fabricated membrane exhibited a remarkable water permeability of 296.2 ± 5.7 L/m2·h·bar and an extremely low BSA loss rate of 0.06 ± 0.02%, i.e., a high BSA retention of 99.94%. In consideration of these properties, the studied membranes are well-suited for use in either water treatment or hemodialysis. Overall, our membranes could be considered for the latter application with a high urea clearance of 257.6 mL/min, which is comparable with commercial membranes.
Study on High-Strain-Rate Deformation of Magnesium Alloy Using Underwater Shock Waves Generated by High-Voltage Electric Discharge of Thin Wire
Authors: Iyama Hirofumi , Yamaguchi Hayato , Nishi Masatoshi , Higa Yoshikazu
Published: November 2022

Magnesium is an abundant material with high specific strength, and its use as a structural metal is increasing. However, its properties cause difficulty in its formation at room temperature. Therefore, the objective of this study was to form a magnesium alloy at room temperature using an underwater shock wave generated by the discharge of an aluminum wire. Forming was conducted using an auxiliary plate composed of aluminum instead of magnesium alloy alone. In addition, hyperbolic and parabolic pressure vessels were employed. Numerical simulations were performed to measure the pressure values, propagation of underwater shock waves, and deformation of the magnesium alloy. Large deformation was observed when an auxiliary aluminum plate was placed on the upper surface of an AZ31 magnesium alloy plate inside the hyperbolic pressure vessel.
Research on Single Point Incremental Forming Characteristics of Perforated TA1 Sheet
Authors: Li Ruxiong , Wang Tao
Published: November 2022

In view of its high compactibility, flexibility, reduced compacting pressure, and other superiorities, the single point incremental forming (SPIF) technique has been applied increasingly in the cranial prosthesis forming of perforated TA1 sheet with irregular surface features. Whereas the SPIF of perforated sheet, which seems to meet many challenges in the biomedicine field, where control of component geometric dimensions are qualification requirements of cranial prosthesis. The mechanism of incremental forming and characteristics of perforated TA1 sheet become more complicated because of the mesh apertures. Hence, certain path and forming technique parameters were set to conduct finite element modelling on the truncated right angle cone components of perforated TA1 sheet and titanium plate respectively on the basis of the ANSYS/LS-DYNA platforms, in light of the constructed model, the distribution and variation law of displacement field coupled with the contour accuracy, wall thickness, and strain capacity for different areas of components in the forming process were obtained by researches, bringing up to light the forming mechanism of conical perforated TA1 sheet components. The research findings indicate that the aperture structure of perforated TA1 sheet allows the material elements to accomplish deformation in the surface where the aperture is located, and the strain rate and radial aperture growth rate of perforated titanium sheet are relatively high, the maximum radial aperture growth rate value is as high as 78.53 percent, the maximum circumferential aperture growth rate value is only 10.84 percent, the extension-thinning of forming section for perforated TA1 sheet is higher than that of the titanium plate, and perforated TA1 sheet possesses higher geometric accuracy than titanium plate.
Characterization of Hot Workability in AISI 4340 Based on a 3D Processing Map
Authors: Park Joonhee , Kim Yosep , Shin Sangyun , Kim Naksoo
Published: November 2022

This study performed high-temperature compression tests at the temperature 900 to 1200 °C and strain rate 0.01 to 10 s−1 to characterize the high-temperature deformation behavior of AISI 4340. The constitutive equation of AISI 4340 was expressed using the Arrhenius model and the Zener–Hollomon (Z) parameter. Dynamic Recrystallization (DRX) behavior was evaluated by observing the compressed specimen with Electron Backscatter Diffraction (EBSD). The processing map is based on the dissipation efficiency of the dynamic material model (DMM) and the plastic instability criterion of Ziegler. At strain 0.4, the power dissipation efficiency value is 0.5 or more, and the instable zones are immediately identified through the processing map. The strain, strain rate and temperature data obtained from the FEM simulation of the hot forging process are displayed on the proposed 3D processing map to avoid the flow instability zones and ensure high power dissipation efficiency zones, allowing the operator to control the process’s temperature and speed.
Performance Analysis of Linearly Arranged Concentric Circular Antenna Array with Low Sidelobe Level and Beamwidth Using Robust Tapering Technique
Authors: Rahaman Imteaz , Haque Md Ashraful , Singh Narinderjit Singh Sawaran , Jafor Md. Shakiul , Sarkar Pallab Kumar , Rahman Md Afzalur , Zakariya Mohd Azman , Abro Ghulam E. Mustafa , Sarker Nayan
Published: November 2022

In this research, a novel antenna array named Linearly arranged Concentric Circular Antenna Array (LCCAA) is proposed, concerning lower beamwidth, lower sidelobe level, sharp ability to detect false signals, and impressive SINR performance. The performance of the proposed LCCAA beamformer is compared with geometrically identical existing beamformers using the conventional technique where the LCCAA beamformer shows the lowest beamwidth and sidelobe level (SLL) of 12.50° and −15.17 dB with equal elements accordingly. However, the performance is degraded due to look direction error, for which robust techniques, fixed diagonal loading (FDL), optimal diagonal loading (ODL), and variable diagonal loading (VDL), are applied to all the potential arrays to minimize this problem. Furthermore, the LCCAA beamformer is further simulated to reduce the sidelobe applying tapering techniques where the Hamming window shows the best performance having 17.097 dB less sidelobe level compared to the uniform window. The proposed structure is also analyzed under a robust tapered (VDL-Hamming) method which reduces around 69.92 dB and 48.39 dB more sidelobe level compared to conventional and robust techniques. Analyzing all the performances, it is clear that the proposed LCCAA beamformer is superior and provides the best performance with the proposed robust tapered (VDL-Hamming) technique.