bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficacy and Long-Term Outcomes of Intra-Articular Autologous Micro-Fragmented Adipose Tissue in Individuals with Glenohumeral Osteoarthritis: A 36-Month Follow-Up Study
Authors: Natali Simone , Screpis Daniele , Patania Edoardo , De Berardinis Luca , Benoni Andrea , Piovan Gianluca , Iacono Venanzio , Magnan Bruno , Gigante Antonio Pompilio , Zorzi Claudio
Published: August 2023

Background: Glenohumeral osteoarthritis (GOA) is associated with disabling shoulder pain that affects everyday life. Its management comprises various treatment approaches, both conservative and surgical. Regenerative medicine has gained a major role in the conservative treatment of osteoarthritis. Intra-articular injection of adipose-derived mesenchymal stem cells (ADMSCs) is a widely used regenerative medicine approach. The aim of this retrospective study was to report the safety and clinical outcomes of intra-articular injection of ADMSCs in patients with GOA over 36-months. Methods: This retrospective observational study involved patients with chronic shoulder pain resistant to standard conservative treatment and a diagnosis of concentric GOA, who received an intra-articular injection of autologous micro-fragmented adipose tissue (μFAT). The values of the Constant–Murley score (CMS), the visual analog scale (VAS), and the simple shoulder test (SST), collected at baseline and at 12, 24, and 36 months, were analyzed to assess treatment efficacy. The single assessment numeric evaluation (SANE) was used to rate patient satisfaction. The Friedman test was used to compare observations of CMS, VAS, and SST values repeated on the same subjects. The significance threshold was set at 0.05. Results: The participants were 65 patients with a mean age of 54.19 years and a nearly equal gender distribution. Most had mild concentric GOA classified as Samilson–Prieto grade 1. The mean follow-up duration was 44.25 months. The postoperative clinical scores showed significant improvement. At 36 months, the CMS was 84.60, the VAS score was 3.34, and the SST score was 10.15 (all p < 0.0001). The SANE score at 36 months indicated that 54 patients (83.08%) were completely satisfied with the treatment. Conclusion: ADMSC treatment exerted favorable effects on the clinical outcomes of patients with GOA, providing pain relief and improving shoulder function. Our data support its use as a conservative treatment option for osteoarthritis.
Inflammatory Determinants and Associated Morbidity in Hemodialysis Patients
Authors: De la Cruz-Ahumada Claudia Jackelin , Topete-Reyes Jorge Fernando , Mena-Ramírez Juan Pablo , Guzmán-Flores Juan Manuel , Guzmán-González Jesúa Ivan , Ramírez-De los Santos Saúl
Published: August 2023

Hemodialysis deteriorates patients’ physical, metabolic, and mental status. Clinical outcomes derived from inflammation determine a worse status but are less frequently identified. The objective of the study was to identify inflammatory determinants and the effect of SNP-related serum IL-6 and IL-10 levels on associated morbidity in hemodialysis. A sample of hemodialysis patients at IMSS Regional Hospital No.46 in Guadalajara (n = 85) were tested using the Malnutrition Inflammation Score (MIS) and Patient Health Questionnaire-9 (PHQ-9) to assess the associated morbidity. Serum cytokine levels were quantified by enzyme-linked immunosorbent assay (ELISA). The restriction fragment length polymorphism (RFLP) technique was used for analysis of IL-6-572C/G and IL-10-1082A/G. Using data visualization methods, we identified relevant determinants of inflammation. A simple regression model was constructed between predictors and targets with genotypes as covariates. Results showed malnutrition in 85.9% of patients and depressive symptoms in 50.6%. IL-10 was the most relevant inflammatory determinant, with regression coefficients (R2) between 0.05 and 0.11. The GG genotype of IL-10-1082 A/G evinced small effect on both clinical outcomes (δ of 0.35 and 0.37, respectively). Hemodialysis increases the associated morbidity, cytokines act as inflammatory determinants, and genetic variability contributes to the severity of clinical outcomes. Further studies need to refine the causal relationship between inflammation and CKD.
Cytotoxic Activity of Melatonin Alone and in Combination with Doxorubicin and/or Dexamethasone on Diffuse Large B-Cell Lymphoma Cells in In Vitro Conditions
Authors: Mańka Sylwia , Smolewski Piotr , Cebula-Obrzut Barbara , Majchrzak Agata , Szmejda Klaudia , Witkowska Magdalena
Published: August 2023

Melatonin (MLT), a pineal gland hormone, not only regulates circadian and seasonal rhythms, but also plays an important role in many aspects of human physiology and pathophysiology. MLT is of great interest as a natural substance with anti-cancer activities. The aim of this study was to assess the cytotoxicity and apoptosis of MLT, used alone or in combination with one of the most active anti-cancer drugs, doxorubicin (DOX), and a well-known anti-inflammatory drug, dexamethasone (DEX), on a diffuse large B-cell lymphoma (DLBCL)-derived cell line. The cytotoxicity and cell cycle distribution were measured using propidium iodide staining, while apoptosis was assessed using the annexin-V binding method. Additionally, to elucidate the mechanisms of action, caspase-3, -8, and -9 and a decline in the mitochondrial potential were determined using flow cytometry. MLT inhibited cell viability as well as induced apoptosis and cell cycle arrest at the G0/G1 phase. The pro-apoptotic effect was exerted through both the mitochondrial and caspase-dependent pathways. Furthermore, we observed increased cytotoxic and pro-apoptotic activity as well as the modulation of the cell cycle after the combination of MLT with DOX, DEX, or a combination of DOX + DEX, compared with both drugs or MLT used alone. Our findings confirm that MLT is a promising in vitro anti-tumour agent that requires further evaluation when used with other drugs active against DLBCL.
Can We Prevent Irreversible Decline? A Comprehensive Analysis of Natural Conditions and Quality Factor Thresholds of Cultivated Land in China
Authors: Tang Huaizhi , Niu Zibing , Cheng Feng , Niu Jiacheng , Zhang Leina , Guo Mengyu , Huang Yuanfang
Published: August 2023

Over the past two decades, China’s spatial distribution of cultivated land has been stable, yet there remains an urgent need to amplify grain productivity. The central scientific question addressed in this study is: How can we effectively evaluate the natural resource thresholds of cultivated land at a regional scale? Despite existing systems, there is a noticeable gap, particularly in this area of inquiry. Recognizing the present state of these resources and introducing more efficient management strategies is pivotal. This paper aims to research the restrictive situation of the natural resources background quality (NRB-quality) of China’s cultivated land by developing an innovative classification method and a short-board identification method and adopting cluster analysis and other technical methods. The results showed that (1) China mainly maintains medium-quality land (57.30%). The soil texture displayed a fine average grade of 1.39, while the biodiversity, soil pH, secondary land types, and cropping systems indicated poor conditions, with average scores of 2.01, 2.06, 2.26, and 2.33. (2) A notable difference in the restrictive factors of cultivated land quality emerged, with secondary land types of cultivated land (including paddy field, irrigated land, and dry land) being the only national short-board factor. Regionally, the cropping system, secondary land types of cultivated land, and natural region were identified as short-board factors in 31, 24, and 23 natural regions. (3) The regional difference in cultivated land quality leads to six different management strategies. Eastern regions emphasized stabilizing land distribution and infrastructure enhancement, while China’s western areas advocated cautious development and heightened ecological protection. The findings demonstrated regional differences in the status of cultivated land quality factors; implementing classified management approaches for cultivated land quality factors based on their characteristics is vital to preventing irreversible decline. The study serves as an important basis for the protection and utilization of cultivated land in the new era to clarify the NRB-quality differences of cultivated land in China.
Climate Change and Wetland Ecosystems: The Effects on Halophilous Vegetation Diversity in Il-Ballut ta’ Marsaxlokk Natura 2000 Site (Malta)
Authors: Tavilla Gianmarco , Lamoliere Arthur , Gabarretta James , Attard Vincent , Henwood Jonathan , Stevens Darrin T. , del Galdo Gianpietro Giusso , Minissale Pietro , Ranno Veronica , Adamo Maria , Tomaselli Valeria , Sciandrello Saverio , Lanfranco Sandro
Published: August 2023

Climate change poses a fundamental threat to the wetlands. The Mediterranean basin is a biodiversity hotspot, and wetlands are important for maintaining this status. The current study evaluated the halophilous vegetation diversity of one of the most relevant Maltese wetlands, Il-Ballut ta’ Marsaxlokk Natura 2000 site, also identified under the Water Framework Directive. A vegetation analysis was carried out according to the Braun–Blanquet approach. The processed dataset included both data from the literature and unpublished data. To quantify vegetation structure and diversity, a hierarchical classification (Chord distance; Ward linkage) and diversity and ecological indices were performed. Diachronic analysis of the taxonomic diversity indices and the Ellenberg indicator values were taken into account. We used an NMDS analysis to assess the ecological fingerprint of the vegetation. In addition, we provided an actual vegetation map for Il-Ballut ta’ Marsaxlokk, based on drone orthophotos. We identified five EU Directive habitats in the study area (1150*, 1310, 1410, 1420, and 92D0) of which one (1150*) was reported for the first time. The ecological fingerprint of the halophilous vegetation has undergone changes over time, particularly due to increasing temperatures. In fact, the results showed that nutrients and temperature were the strongest environmental drivers of the site. The results and methodology of this study demonstrate how vegetation studies can serve as tools to improve knowledge, management actions, and landscape planning of Natura 2000 sites.
(Mis)pronunciations of Hispanic Given Names in the U.S.: Positionalities and Discursive Strategies at Play
Authors: Enríquez Duque Paola
Published: August 2023

This qualitative study examines the indexical nature of given names and their role in self-positioning within diverse social contexts. The study centers on the pronunciation of Hispanic given names in the United States. The analysis is grounded in interviews with six young adults who recognize that their names have Spanish and English variants, and it demonstrates that bearers’ phonological awareness plays a critical role in distinguishing name variants and mispronunciations, as evidenced through metalinguistic comments. These distinctions are additionally shaped by personal criteria. By examining the participants’ narratives and one participant’s discursive strategies in particular, I show that the pronunciation of given names constitutes a significant linguistic resource intentionally mobilized and managed to negotiate social positionings. Moreover, this research highlights that conferring Hispanic given names in the U.S. constitutes a sociocultural strategy that extends beyond an indexical ethnocultural naming practice across generations. This practice is found to be a means of fostering and maintaining intergenerational relationships.
The Role of the Intraoperative Optical Coherence Tomography for Vitreoretinal Surgery in a Real-Life Setting
Authors: Parolini Barbara , Ripa Matteo , Frisina Rino , Matello Veronika , Motta Lorenzo
Published: August 2023

Background: To descriptively report the advantages and the feasibility of microscope-integrated intraoperative optical coherence tomography (i-OCT) in managing different vitreoretinal diseases in a real-life setting. Methods: We conducted an observational retrospective study involving 265 eyes that underwent elective retinal surgery and intraoperative OCT between 1 September 2018 and 1 October 2022 at Eyecare Clinic (Brescia, Italy). Results: 52 epiretinal membranes, 30 retinal detachments, 60 high myopic eyes, 30 choroidal transplants, 40 macular holes, and 32 vitreo-proliferative retinopathies underwent vitreoretinal surgery and intraoperative OCT scans. The i-OCT was a useful diagnostic exam for all cases and significantly influenced our surgical management. Conclusions: i-OCT is a helpful surgical tool in ophthalmic surgery as it provides real-time feedback of tissue anatomy to surgeons, thereby guiding decision-making. Moreover, it provides additional information on the microarchitectural changes after instrument–tissue interactions, further guiding procedures when necessary and possibly reducing unessential surgical maneuvers.
Total and Extracellular Vesicle cAMP Contents in Urine Are Associated with Autosomal Dominant Polycystic Kidney Disease (ADPKD) Progression
Authors: Rosenberg María Lucía , Yaneff Agustín , Ferradás Gonzalo Manuel , Villafañe Tapia Margarita Paz , Davio Carlos Alberto , Goette Nora Paula , Vlachovsky Sandra Gabriela , Peroni Roxana Noemí , Oddo Elisabet Mónica , Azurmendi Pablo Javier
Published: August 2023

ADPKD is the most common genetic renal disease, characterized by the presence of multiple cysts which, through slow and gradual growth, lead to glomerular filtration rate (GFR) decline and end-stage renal disease. Cystic growth is associated with increased intracellular levels of 3′,5′-cyclic adenosine monophosphate (cAMP). Extracellular vesicles (EVs) are proposed to participate in “remote sensing” by transporting different cargoes, but their relevance to ADPKD progression is poorly understood. This study aimed to determine whether cAMP is contained in urinary EVs and, if so, how total and/or EV cAMP contents participate in disease progression. Fourteen ADPKD patients, naïve for V2 receptor antagonism treatment, and seven controls were studied. Progression was evaluated by estimating GFR (eGFR) and height-adjusted total kidney volume (htTKV). Fresh morning urine was collected to determine cAMP by the competitive radioligand assay. Urine EVs were isolated using an adapted centrifugation method and characterized by electron microscopy, dynamic light scanning, flow cytometry with FITC CD63 labeling, protein and RNA content, and AQP2 and GAPDH mRNA detection. Total and EV cAMP was measurable in both control and patient urine samples. Total cAMP was significantly correlated with eGFR and its annual change but inversely correlated with htTKV. The cAMP-EVs showed a bimodal pattern with htTKV, increasing to ~1 L/m and falling at larger sizes. Our results demonstrate that urine cAMP correlates with ADPKD progression markers, and that its extracellular delivery by EVs could reflect the architectural disturbances of the organ.
The Potential Role of Salivary NT-proBNP in Heart Failure
Authors: Rammos Aidonis , Bechlioulis Aris , Kalogeras Petros , Watson Chris J. , Salvo Pietro , Lomonaco Tommaso , Kardakari Olga , Tripoliti Evanthia E. , Goletsis Yorgos , Fotiadis Dimitris I. , Katsouras Christos S. , Michalis Lampros K. , Naka Katerina K.
Published: August 2023

Background: Serum natriuretic peptides (NPs) have an established role in heart failure (HF) diagnosis. Saliva NT-proBNP that may be easily acquired has been studied little. Methods: Ninety-nine subjects were enrolled; thirty-six obese or hypertensive with dyspnoea but no echocardiographic HF findings or raised NPs served as controls, thirteen chronic HF (CHF) patients and fifty patients with acute decompensated HF (ADHF) requiring hospital admission. Electrocardiogram, echocardiogram, 6 min walking distance (6MWD), blood and saliva samples, were acquired in all participants. Results: Serum NT-proBNP ranged from 60–9000 pg/mL and saliva NT-proBNP from 0.64–93.32 pg/mL. Serum NT-proBNP was significantly higher in ADHF compared to CHF (p = 0.007) and in CHF compared to controls (p < 0.05). There was no significant difference in saliva values between ADHF and CHF, or between CHF and controls. Saliva and serum levels were positively associated only in ADHF patients (R = 0.352, p = 0.012). Serum NT-proBNP was positively associated with NYHA class (R = 0.506, p < 0.001) and inversely with 6MWD (R = −0.401, p = 0.004) in ADHF. Saliva NT-proBNP only correlated with age in ADHF patients. Conclusions: In the current study, saliva NT-proBNP correlated with serum values in ADHF patients, but could not discriminate between HF and other causes of dyspnoea. Further research is needed to explore the value of saliva NT-proBNP.
Full Characterization of Self-Compacting Concrete Containing Recycled Aggregates and Limestone
Authors: Guessoum Meriem , Boukhelf Fouad , Khadraoui Fouzia
Published: August 2023

This work deals with the study of self-compacting concretes (SCCs) containing recycled aggregates (RAs) recovered from demolition waste and limestone filler as a partial replacement for natural aggregates (NAs) and cement, respectively. Four mix designs were developed and characterized in both the fresh and hardened states. In the fresh state, the properties studied included slump, sieve stability, and t500 viscosity. In the hardened state, the properties studied were compressive strength and porosity at 15 h and 28 days, thermogravimetric analysis, and durability tests involving freeze–thaw cycles and accelerated carbonation. The results indicate the RAs lead to a decrease in slump flow. However, the substitution rate of aggregate replacement does not affect the compressive strength. This can be attributed to the optimized mix design, resulting in all SCC mixtures achieving the same compressive strength class of 30–35 MPa. As for the durability tests, the incorporation of recycled aggregates modifies the behavior of the concrete during freeze–thaw cycles. Throughout the 300 freeze–thaw cycles, all concrete mixtures exhibited a mass loss accompanied by a slight strain increase, but the materials remained visually intact. Additionally, the carbonation depth is strongly influenced by the rate of aggregate replacement due to changes in the microstructure, particularly in porosity.
Tribological Evaluation of Vegetable Oil/MoS2 Nanotube-Based Lubrication of Laser-Textured Stainless Steel
Authors: Conradi Marjetka , Podgornik Bojan , Remškar Maja , Klobčar Damjan , Kocijan Aleksandra
Published: August 2023

In the present work, the functionalisation of austenitic stainless steel, AISI 316L surfaces via nanosecond Nd:YAG laser texturing in order to modify the surface morphology with crosshatch and dimple patterns is presented. A tribological analysis under lubrication with sunflower and jojoba oil with and without the addition of a solid lubricant, MoS2 nanotubes, was performed. In conjunction with friction/wear response laser-textured surface wettability, oil spreadability and oil retention capacity were also analysed. It was shown that the crosshatch pattern generally exhibited lower friction than the dimple pattern, with the addition of MoS2 nanotubes not having any significant effect on the coefficient of friction under the investigated contact conditions. This was found in addition to the better oil spreadability and oil retention capacity results of the crosshatch-textured surface. Furthermore, texturing reduced the wear of the stainless-steel surfaces but led to an approximately one order of magnitude larger wear rate of the steel counter-body, primarily due to the presence of hard bulges around the textured patterns. Overall, the crosshatch pattern showed better oil retention capacity and lower friction in combination with different vegetable oils, thus making it a promising choice for improving tribological performance in various environmentally friendly applications.
Assessment of the Environmental Impact of Solid Oil Materials Based on Pyrolysis Oil
Authors: Staroń Anita , Kijania-Kontak Magda , Dziadas Mariusz , Banach Marcin
Published: August 2023

One method of managing used car tires is decomposition by thermochemical conversion methods. By conducting the process at temperatures of 450–750 °C, three fractions are obtained from tires: oil, gas, and solid. The liquid product of the pyrolysis of used car tires is pyrolysis oil, which consists of aromatic, polyaromatic, and aliphatic hydrocarbons. Unconventional building materials were obtained from tire pyrolysis oil and the environmental impact was evaluated. Blocks made from pyrolysis oil showed mechanical strength of up to about 1700 N. No heavy metals or polycyclic aromatic hydrocarbons, which were found in the crude heavy-PO fraction, were detected in the filtrates after incubation of the block obtained from the heavy-PO fraction at 240 °C. The highest inhibition of Sorghum saccharatum shoot (74.4%) and root (57.5%) growth was observed for solid materials from the medium-PO fraction obtained at 240 °C. The most favorable values of the parameters for the process of obtaining blocks based on post-PO were an annealing temperature of 180 °C, time of 20 h, and mass ratio of catalyst to catalyzed oil of 0.045.
Performance and Durability of Non-Stick Coatings Applied to Stainless Steel: Subtractive vs. Additive Manufacturing
Authors: Guerrero-Vacas Guillermo , Rodríguez-Alabanda Oscar , Martín-Fernández Francisco de Sales , Martín-Sánchez María Jesús
Published: August 2023

This study compares subtractive manufacturing (SM) and additive manufacturing (AM) techniques in the production of stainless-steel parts with non-stick coatings. While subtractive manufacturing involves the machining of rolled products, additive manufacturing employs the FFF (fused filament fabrication) technique with metal filament and sintering. The applied non-stick coatings are commercially available and are manually sprayed with a spray gun, followed by a curing process. They are an FEP (fluorinated ethylene propylene)-based coating and a sol–gel ceramic coating. Key properties such as surface roughness, water droplet sliding angle, adhesion to the substrate and wear resistance were examined using abrasive blasting techniques. In the additive manufacturing process, a higher roughness of the samples was detected. In terms of sliding angle, variations were observed in the FEP-based coatings and no variations were observed in the ceramic coatings, with a slight increase for FEP in AM. In terms of adhesion to the substrate, the ceramic coatings applied in the additive process showed a superior behavior to that of subtractive manufacturing. On the other hand, FEP coatings showed comparable results for both techniques. In the wear resistance test, ceramic coatings outperformed FEP coatings for both techniques. In summary, additive manufacturing of non-stick coatings on stainless steel showed remarkable advantages in terms of roughness, adhesion and wear resistance compared to the conventional manufacturing approach. These results are of relevance in fields such as medicine, food industry, chemical industry and marine applications.
Optimal Design of Validation Experiment for Material Deterioration
Authors: Song Xiangrong , Sun Dongyang , Liang Xuefeng
Published: August 2023

For the deterioration model of a material, it is crucial to design a validation experiment to determine the ability of the deterioration model to simulate the actual deterioration process. In this paper, a design method of a validation experiment for a deterioration model is proposed to obtain the experiment scheme with low cost and satisfactory credibility. First, a normalized area metric based on probability density functions for the deterioration model is developed for validation results quantification. Normalized area metrics of different state variables in an engineering system can be applied to a unified evaluation standard. In particular, kernel density estimation is used to obtain smooth probability density functions from discrete experimental data, which can reduce the systematic error of the validation metric. Furthermore, a design method for the validation experiment for the deterioration model is proposed, in which the number of experimental samples and observation moments in each experimental sample are design variables, while the credibility of the validation experiment is the constraint. For the experiment design, the problem with varying dimensions of design variables occurred in the optimal design. Thus, a collaborative optimization method using the Latin hypercube sampling was developed to solve this problem. Finally, the results of the two examples showed the characteristics of the proposed metric and also reflected the correlation between the design variables and experimental credibility.
Mechanical Behavior of Anchor Bolts for Shallow Super-Large-Span Tunnels in Weak Rock Mass
Authors: He Shaohui , He Jiaxin , Ma Jianfei , Liu Xiabing , Li Yiming , Zhang Bin
Published: August 2023

Based on the Xiabeishan No.2 tunnel project of the Hang-Shao-Tai high-speed railway in China, the mechanical behavior of the anchor bolts for shallow super-large-span (SSLS) tunnels in weak rock mass is comprehensively investigated through laboratory tests, numerical simulation, and field tests. Firstly, an eight-month field test is conducted in the Xiabeishan No.2 tunnel, and it is discovered that the blasting vibration created by the construction of the middle pilot tunnel caused serious damage to the temporary support, seriously affecting the development of the bolt axial force and causing great construction risks. Then, the refined finite difference model of the SSLS tunnels is formulated, and a series of field and laboratory tests are conducted to acquire the calculation parameters. By comparing the monitored and simulated bolt axial force, the reliability of the numerical model is verified. Subsequently, the influence of the rock condition, construction scheme and bolt length on the mechanical behavior of anchor bolts is discussed. It is revealed that the rock grade significantly affects the bearing characteristics of anchor bolts. The construction scheme can greatly affect the magnitude and development mode of the bolt axial force, but the final distribution characteristics of the bolt axial force do not change regardless of the construction sequence. The axial force of the anchor bolts grows rapidly with the bolt length when the bolt length is within 18 m; meanwhile, when the bolt length exceeds 18 m, increasing the bolt length has a limited effect on the improvement in the bolt support performance. Finally, some optimization measures are proposed according to the monitoring data and simulation results.
Fatigue Behavior of the FGH96 Superalloy under High-Temperature Cyclic Loading
Authors: Li Zhengguang , Qin Haiqin , Xu Kejun , Xie Zhenbo , Ji Pengcheng , Jia Mingming
Published: August 2023

Strain-controlled low-cycle fatigue (LCF) tests and stress-controlled creep-fatigue interaction (CFI) tests on the FGH96 superalloy were carried out at 550 °C to obtain the cyclic softening/hardening characteristics at different strain amplitudes and ratcheting strain characteristics under different hold time. The failure mechanism of the FGH96 superalloy under different loading conditions was analyzed through fracture observations. The results show that the FGH96 superalloy exhibits different cyclic softening/hardening characteristics at different strain amplitudes, and the introduction of the hold time at peak stress exacerbates the ratcheting strain of the FGH96 superalloy under asymmetric stress cycles. Fracture observations show that the magnitude of the strain amplitude, high-temperature oxidation, and the introduction of the hold time will affect the mechanical properties of the FGH96 superalloy and change its fracture mode.
Multiparameter Estimation-Based Sensorless Adaptive Direct Voltage MTPA Control for IPMSM Using Fuzzy Logic MRAS
Authors: Elhaj Alaref , Alzayed Mohamad , Chaoui Hicham
Published: August 2023

This paper introduces a parameter-estimation-based sensorless adaptive direct voltage maximum torque per ampere (MTPA) control strategy for interior permanent magnet synchronous machines (IPMSMs). In direct voltage control, the motor’s electrical parameters, speed, and rotor position are of great significance. Thus, any mismatch in these parameters or failure to acquire accurate speed or position information leads to a significant deviation in the MTPA trajectory, causing high current consumption and hence affecting the performance of the entire control system. In view of this problem, a fuzzy logic control-based cascaded model reference adaptive system (FLC-MRAS) is introduced to mitigate the effect of parameter variation on the tracking of the MTPA trajectory and to provide precise information about the rotor speed and position. The cascaded scheme consists of two parallel FLC-MRAS for speed and multiparameter estimation. The first MRAS is utilized to estimate motor speed and rotor position to achieve robust sensorless control. However, the speed estimator is highly dependent on time-varying motor parameters. Therefore, the second MRAS is designed to identify the quadratic inductance and permanent magnet flux and continuously update both the speed estimator and control scheme with the identified values to ensure accurate speed estimation and real-time MTPA trajectory tracking. Unlike conventional MRAS, which uses linear proportional-integral controllers (PI-MRAS), an FLC is adopted to replace the PI controllers, ensuring high estimation accuracy and enhancing the robustness of the control system against sudden changes in working conditions. The effectiveness of the proposed scheme is evaluated under different speed and torque conditions. Furthermore, a comparison against the conventional PI-MRAS is extensively investigated to highlight the superiority of the proposed scheme. The evaluation results and our quantitative assessment show the ability of the designed strategy to achieve high estimation accuracy, less oscillation, and a faster convergence rate under different working conditions. The quantitative assessment reveals that the FLC-MRAS can improve the estimation accuracy of speed, permanent magnet flux, and quadratic inductance by 19%, 55.8% and 44.55%, respectively.
Experimental Study on the Effect of Microchannel Spacing and Fractal Angle on Bubble Growth Behavior
Authors: Gao Xianming , Lu Fangcai , Zhang Wang , Yang Wenxuan
Published: August 2023

Bubble growth behavior significantly influences boiling heat transfer performance, and different microchannel structures and configurations affect bubble growth behavior. To explore the impact of microchannel structures and configurations on the growth behavior of boiling bubbles, two types of microchannel test plates were fabricated on copper substrates using laser machining technology. It was a parallel configuration plate with five different microchannel spacings and a blade vein configuration plate with four different fractal angles. The bubble growth behavior on these two types of surfaces was studied through visual experiments. The results show that smaller microchannel spacing leads to earlier bubble coalescence and departure times under the same degree of superheat. The 3.00 mm microchannel spacing is the critical interfering distance for the parallel configuration plates, while interference behavior occurs for the bubbles on the simulated vein configuration plates at any fractal angle. Furthermore, in different ranges of superheat, the bubble departure diameter increases with increasing superheat, and the frequency of bubble departure initially increases and then decreases with increasing superheat. This study provides experimental data support and design reference for the design of heat transfer plate structures.
Exploring the Influence of Induced Magnetic Fields and Double-Diffusive Convection on Carreau Nanofluid Flow through Diverse Geometries: A Comparative Study Using Numerical and ANN Approaches
Authors: Jakeer Shaik , Reddy Seethi Reddy Reddisekhar , Easwaramoorthy Sathishkumar Veerappampalayam , Basha Hayath Thameem , Cho Jaehyuk
Published: August 2023

This current investigation aims to explore the significance of induced magnetic fields and double-diffusive convection in the radiative flow of Carreau nanofluid through three distinct geometries. To simplify the fluid transport equations, appropriate self-similarity variables were employed, converting them into ordinary differential equations. These equations were subsequently solved using the Runge–Kutta–Fehlberg (RKF) method. Through graphical representations like graphs and tables, the study demonstrates how various dynamic factors influence the fluid’s transport characteristics. Additionally, the artificial neural network (ANN) approach is considered an alternative method to handle fluid flow issues, significantly reducing processing time. In this study, a novel intelligent numerical computing approach was adopted, implementing a Levenberg–Marquardt algorithm-based MLP feed-forward back-propagation ANN. Data collection was conducted to evaluate, validate, and guide the artificial neural network model. Throughout all the investigated geometries, both velocity and induced magnetic profiles exhibit a declining trend for higher values of the magnetic parameter. An increase in the Dufour number corresponds to a rise in the nanofluid temperature. The concentration of nanofluid increases with higher values of the Soret number. Similarly, the nanofluid velocity increases with higher velocity slip parameter values, while the fluid temperature exhibits opposite behavior, decreasing with increasing velocity slip parameter values.
Joint Optimization of Maintenance and Spare Parts Inventory Strategies for Emergency Engineering Equipment Considering Demand Priorities
Authors: Wang Xiaoyue , Wang Jingxuan , Ning Ru , Chen Xi
Published: August 2023

To respond to emergencies in a timely manner, emergency engineering equipment has been an important tool to implement emergency strategies. However, random failures of the equipment may occur during operation. Therefore, appropriate maintenance and spare parts inventory strategies are crucial to ensure the smooth operation of the equipment. Furthermore, the urgency degree of emergencies varies in practice. Nevertheless, existing studies rarely consider the impact of urgency degree and demand priorities on the service order of the equipment. To bridge the research gaps, this paper establishes a joint optimization model of maintenance and spare parts inventory strategies for emergency engineering equipment considering demand priorities. The proposed model includes two types of emergency engineering equipment with different service rates. The more urgent demand can be fulfilled by the equipment with a higher priority. Corrective maintenance and spare parts inventory policies are simultaneously performed for the equipment. The Markov process imbedding method is utilized to derive the probabilistic indexes of the system. To maximize the system availability, the number of maintenance engineers and the spare parts inventory strategy is optimized via the construction of the joint optimization model. The optimal solution for the optimization problem is obtained using the branch-and-bound method. Finally, this study presents practical examples to verify the effectiveness of the model and methods.
Leveraging Minimum Nodes for Optimum Key Player Identification in Complex Networks: A Deep Reinforcement Learning Strategy with Structured Reward Shaping
Authors: Zeng Li , Fan Changjun , Chen Chao
Published: August 2023

The problem of finding key players in a graph, also known as network dismantling, or network disintegration, aims to find an optimal removal sequence of nodes (edges, substructures) through a certain algorithm, ultimately causing functional indicators such as the largest connected component (GCC) or network pair connectivity in the graph to rapidly decline. As a typical NP-hard problem on graphs, recent methods based on reinforcement learning and graph representation learning have effectively solved such problems. However, existing reinforcement-learning-based key-player-identification algorithms often need to remove too many nodes in order to achieve the optimal effect when removing the remaining network until no connected edges remain. The use of a minimum number of nodes while maintaining or surpassing the performance of existing methods is a worthwhile research problem. To this end, a novel algorithm called MiniKey was proposed to tackle such challenges, which employs a specific deep Q-network architecture for reinforcement learning, a novel reward-shaping mechanism based on network functional indicators, and the graph-embedding technique GraphSage to transform network nodes into latent representations. Additionally, a technique dubbed ‘virtual node technology’ is integrated to grasp the overarching feature representation of the whole network. This innovative algorithm can be effectively trained on small-scale simulated graphs while also being scalable to large-scale real-world networks. Importantly, experiments from both six simulated datasets and six real-world datasets demonstrates that MiniKey can achieve optimal performance, striking a perfect balance between the effectiveness of key node identification and the minimization of the number of nodes that is utilized, which holds potential for real-world applications such as curbing misinformation spread in social networks, optimizing traffic in transportation systems, and identifying key targets in biological networks for targeted interventions.
Development of a Novel Marine-Derived Tricomposite Biomaterial for Bone Regeneration
Authors: Aslam Bilal , Augustyniak Aleksandra , Clarke Susan A. , McMahon Helena
Published: August 2023

Bone tissue engineering is a promising treatment for bone loss that requires a combination of porous scaffold and osteogenic cells. The aim of this study was to evaluate and develop a tricomposite, biomimetic scaffold consisting of marine-derived biomaterials, namely, chitosan and fucoidan with hydroxyapatite (HA). The effects of chitosan, fucoidan and HA individually and in combination on the proliferation and differentiation of human mesenchymal stem cells (MSCs) were investigated. According to the SEM results, the tricomposite scaffold had a uniform porous structure, which is a key requirement for cell migration, proliferation and vascularisation. The presence of HA and fucoidan in the chitosan tricomposite scaffold was confirmed using FTIR, which showed a slight decrease in porosity and an increase in the density of the tricomposite scaffold compared to other formulations. Fucoidan was found to inhibit cell proliferation at higher concentrations and at earlier time points when applied as a single treatment, but this effect was lost at later time points. Similar results were observed with HA alone. However, both HA and fucoidan increased MSC mineralisation as measured by calcium deposition. Differentiation was significantly enhanced in MSCs cultured on the tricomposite, with increased alkaline phosphatase activity on days 17 and 25. In conclusion, the tricomposite is biocompatible, promotes osteogenesis, and has the structural and compositional properties required of a scaffold for bone tissue engineering. This biomaterial could provide an effective treatment for small bone defects as an alternative to autografts or be the basis for cell attachment and differentiation in ex vivo bone tissue engineering.
Cladding Failure Modelling for Lead-Based Fast Reactors: A Review and Prospects
Authors: Wang Guan , Wang Zhaohao , Yun Di
Published: August 2023

Lead-cooled fast reactors (LFRs) are considered one of the most promising technologies to meet the requirements introduced for advanced nuclear systems. LFRs have higher neutron doses, higher temperatures, higher burnup and an extremely corrosive environment. The failure studies of claddings play a vital role in improving the safety criteria of nuclear reactors and promoting research on advanced nuclear materials. This paper presented a comprehensive review of the extreme environment in LFRs based on the fuel performance analyses and transient analyses of reference LFRs. It provided a clear image of cladding failure, focusing on the underlying mechanisms, such as creep, rupture, fatigue, swelling, corrosion, etc., which are resulted from the motions of defects, the development of microcracks and accumulation of fission products to some extent. Some fundamental parameters and behavior models of Ferritic/Martensitic (F/M) steels and Austenitic stainless (AuS) steels were summarized in this paper. A guideline for cladding failure modelling was also provided to bridge the gap between fundamental material research and realistic demands for the application of LFRs.
Antioxidative Stress Metabolic Pathways in Moderately Active Individuals
Authors: Almuraikhy Shamma , Anwardeen Najeha , Doudin Asmma , Sellami Maha , Domling Alexander , Agouni Abdelali , Althani Asmaa A. , Elrayess Mohamed A.
Published: August 2023

Physical activity (PA) is known to have beneficial effects on health, primarily through its antioxidative stress properties. However, the specific metabolic pathways that underlie these effects are not fully understood. This study aimed to investigate the metabolic pathways that are involved in the protective effects of moderate PA in non-obese and healthy individuals. Data on 305 young, non-obese participants were obtained from the Qatar Biobank. The participants were classified as active or sedentary based on their self-reported PA levels. Plasma metabolomics data were collected and analyzed to identify differences in metabolic pathways between the two groups. The results showed that active participants had increased activation of antioxidative, stress-related pathways, including lysoplasmalogen, plasmalogen, phosphatidylcholine, vitamin A, and glutathione. Additionally, there were significant associations between glutathione metabolites and certain clinical traits, including bilirubin, uric acid, hemoglobin, and iron. This study provides new insights into the metabolic pathways that are involved in the protective effects of moderate PA in non-obese and healthy individuals. The findings may have implications for the development of new therapeutic strategies that target these pathways.
Design of High-Precision Parallel AWG Demodulation System
Authors: Jiao Yunjing , Lin Qijing , Yao Kun , Zhao Na , Xian Dan , Zhang Fuzheng , Meng Qingzhi , Tian Bian , Jiang Zhuangde
Published: August 2023

Here, we present a high-precision demodulation method that supports the arrayed waveguide grating (AWG) system, which includes a 1 × 8 AWG as the primary filter with a 0.5 nm channel spacing and a 1 × 4 AWG as the auxiliary filter with a 1 nm channel spacing. The high precision is achieved through an innovative method of decoupling three channels, involving two adjacent channels of the primary filter and one channel of the secondary auxiliary filter. Simulation results show that the AWGs have a good transmission spectrum with crosstalk below −24.8 dB, non-uniformities below 0.8 dB, insertion loss below −3.7 dB, 3 dB bandwidth of 0.25 nm, and 10 dB bandwidth of 0.43 nm. The interrogation precision can reach 8 pm, with a dynamic range of 0.4 nm, corresponding to a single FBG.
Study on Low-Temperature Conductive Silver Pastes Containing Bi-Based Glass for MgTiO3 Electronic Power Devices
Authors: Fu Yunsheng , Yu Xianglei , Liu Li , Tang Xianjie , Li Junpeng , Gan Guoyou
Published: August 2023

Low-temperature lead-free silver pastes deserve thorough investigation for sustainable development and application of MgTiO3 ceramics in electronic devices. In this study, a series of Bi2O3-B2O3-ZnO-SiO2-Al2O3-CaO glasses with suitable softening temperatures were prepared via melt quenching using a type of micrometer silver powder formed by silver nanoparticle aggregates. The composite pastes containing silver powder, Bi2O3 glass powder and an organic vehicle were then screen-printed. The effects of glass powder concentration and sintering temperature on the microstructure of the surface interface were also investigated. The results showed that the silver paste for microwave dielectric ceramic filters (MgTiO3) possessed good electrical conductivity (2.28 mΩ/□) and high adhesion (43.46 N/mm2) after medium temperature (670 °C) sintering. Thus, this glass powder has great application potential in non-toxic lead-free silver pastes for metallization of MgTiO3 substrates.
Study on the Fabrication Process of X-ray Focusing Mirrors
Authors: Liao Qiuyan , Ding Fei , Chen Zhigao , Li Duo , Wang Bo
Published: August 2023

The eXTP (enhanced X-ray Timing and Polarization) satellite is a prominent X-ray astronomy satellite designed primarily for conducting deep space X-ray astronomical observations. The satellite’s scientific payload consists of X-ray focusing mirrors. In order to fulfill the requirements of weight reduction and enhanced effective area, the thickness of mirrors is reduced to the sub-millimeter range and a multi-layer nested structure is employed. Manufacturing mirrors poses a significant challenge to both their quality and efficiency. The present research investigates the optimal replication process for mandrel ultraprecision machining, polishing, coating, electroforming nickel, and demolding. It analyzes the factors contributing to the challenging separation and the inability to release the mirror shells. Additionally, an automatic demolding device is developed, and the X-ray performance of the replication mirrors is verified. The fabrication process flow of the mirrors was initially introduced. To ensure the easy release of the mirror shells from the mandrels, a layer of diamond-like carbon (DLC) was applied as a release layer between the Au and NiP alloy. The adhesion strength of Au-C was found to be significantly lower than that of Au-NiP, as demonstrated by both molecular dynamic simulation and tensile testing. The development of an automatic demolding device with force feedback has been successfully completed. The reduction in the half-power diameter (HPD) of the mirror from 48 inches to 25 inches is an improvement that surpasses the production target.
A Simulation Study of Carrier Capture Ability of the Last InGaN Quantum Well with Different Indium Content for Yellow-Light-Emitting InGaN/GaN Multiple Quantum Wells
Authors: Liu Wei , Liu Zeyu , Zhao Hengyan , Gao Junjie
Published: August 2023

Currently, GaN-based blue- and green-light-emitting devices have achieved successful applications in practice, while the luminescence efficiency of devices with longer wavelengths (such as yellow light) is still very low. Therefore, in this paper, the electroluminescence characterization of yellow-light-emitting InGaN/GaN multiple quantum wells (MQWs) with different In content in the last InGaN quantum well, which is next to the p-type GaN electrode layer, are investigated numerically to reveal a possible physical mechanism by which the different distribution of In content in the active region impacts the carrier capture and the light emission process in yellow InGaN/GaN MQWs. The simulation results show that at low injection currents, the luminescence efficiency of high-In-content yellow MQWs is enhanced, which can be ascribed to the enhanced radiative recombination process induced by the increased carrier concentration in the last InGaN quantum wells with promoted carrier capture ability. However, in the case of high injection condition, the luminescence efficiency of yellow MQWs deteriorates with increasing In content, i.e., the droop effect becomes remarkable. This can be ascribed to both significantly enhanced Auger recombination and electron leakage in the last InGaN quantum well, induced also by the promoted capture ability of charge carriers.