bluuebunny/crossref_metadata_2025 huggingface dataset:
Mean-Field-Type Transformers
Authors: Tembine Hamidou , Khan Manzoor Ahmed , Bamia Issa
Published: November 2024

In this article, we present the mathematical foundations of generative machine intelligence and link them with mean-field-type game theory. The key interaction mechanism is self-attention, which exhibits aggregative properties similar to those found in mean-field-type game theory. It is not necessary to have an infinite number of neural units to handle mean-field-type terms. For instance, the variance reduction in error within generative machine intelligence is a mean-field-type problem and does not involve an infinite number of decision-makers. Based on this insight, we construct mean-field-type transformers that operate on data that are not necessarily identically distributed and evolve over several layers using mean-field-type transition kernels. We demonstrate that the outcomes of these mean-field-type transformers correspond exactly to the mean-field-type equilibria of a hierarchical mean-field-type game. Due to the non-convexity of the operators’ composition, gradient-based methods alone are insufficient. To distinguish a global minimum from other extrema—such as local minima, local maxima, global maxima, and saddle points—alternative methods that exploit hidden convexities of anti-derivatives of activation functions are required. We also discuss the integration of blockchain technologies into machine intelligence, facilitating an incentive design loop for all contributors and enabling blockchain token economics for each system participant. This feature is especially relevant to ensuring the integrity of factual data, legislative information, medical records, and scientifically published references that should remain immutable after the application of generative machine intelligence.
QuEst: Adversarial Attack Intensity Estimation via Query Response Analysis
Authors: Lee Eun Gi , Min Chi Hyeok , Yoo Seok Bong
Published: November 2024

Deep learning has dramatically advanced computer vision tasks, including person re-identification (re-ID), substantially improving matching individuals across diverse camera views. However, person re-ID systems remain vulnerable to adversarial attacks that introduce imperceptible perturbations, leading to misidentification and undermining system reliability. This paper addresses the challenge of robust person re-ID in the presence of adversarial examples by estimating attack intensity to enable effective detection and adaptive purification. The proposed approach leverages the observation that adversarial examples in retrieval tasks disrupt the relevance and internal consistency of retrieval results, degrading re-ID accuracy. This approach estimates the attack intensity and dynamically adjusts the purification strength by analyzing the query response data, addressing the limitations of fixed purification methods. This approach also preserves the performance of the model on clean data by avoiding unnecessary manipulation while improving the robustness of the system and its reliability in the presence of adversarial examples. The experimental results demonstrate that the proposed method effectively detects adversarial examples and estimates the attack intensity through query response analysis. This approach enhances purification performance when integrated with adversarial purification techniques in person re-ID systems.
A Novel Nonlinear Adaptive Control Method for Longitudinal Speed Control for Four-Independent-Wheel Autonomous Vehicles
Authors: Zhang Jinhua , Chen Zhenghao , Yu Jinshi
Published: November 2024

As autonomous driving technology and four-independent-wheel chassis systems advance, four-independent-wheel autonomous vehicles have increasingly become a focal area of modern research. The longitudinal control problem for four-independent-wheel autonomous vehicles presents challenges such as complex models, high nonlinearity, and strong system uncertainties. This paper proposes a novel hierarchical control algorithm to address these challenges, innovatively combining the advantages of adaptive backstepping and dynamic sliding mode control algorithms in the upper controller, allowing it to effectively overcome the impact of uncertain system parameters and suppress the common chattering phenomenon in the output of typical sliding mode control methods. Based on the design of the upper controller, an innovative optimized longitudinal force distribution strategy and the construction of a tire reverse longitudinal slip model are proposed, followed by the design of a fuzzy PID controller as the lower slip ratio controller to achieve precise whole-vehicle longitudinal speed tracking and improve overall control performance. This method not only improves the accuracy of speed tracking but also enhances the robustness and adaptability of the control system. Finally, the effectiveness and superiority of the proposed hierarchical control method are verified through CarSim simulations.
Fracture Characteristics and Tensile Strength Prediction of Rock–Concrete Composite Discs Under Radial Compression
Authors: Guo Tengfei , Wang Houqiang , Si Xuefeng , Pu Chengzhi , Liu Zhixiang , Zhang Qi , Liu Weijun
Published: November 2024

To investigate the fracture mechanism of rock–concrete (R–C) systems with an interface crack, Brazilian splitting tests were conducted, with a focus on understanding the influence of the interface crack angle on failure patterns, energy evolution, and RA/AF characteristics. The study addresses a critical issue in rock–concrete structures, particularly how crack propagation differs with varying crack angles, which has direct implications for structural integrity. The experimental results show that the failure paths in R–C disc specimens are highly dependent on the interface crack angle. For crack angles of 0°, 15°, 30°, and 45°, cracks initiate from the tips of the interface crack and propagate toward the loading ends. However, for angles of 60°, 75°, and 90°, crack initiation shifts away from the interface crack tips. The AE parameters RA (rise time/amplitude) and AF (average frequency) were used to characterize different failure patterns, while energy evolution analysis revealed that the highest percentage of energy consumption occurs at a crack angle of 45°, indicating intense microcrack activity. Moreover, a novel tensile strength prediction model, incorporating macro–micro damage interactions caused by both microcracks and macrocracks, was developed to explain the failure mechanisms in R–C specimens under radial compression. The model was validated through experimental results, demonstrating its potential for predicting failure behavior in R–C systems. This study offers insights into the fracture mechanics of R–C structures, advancing the understanding of their failure mechanisms and providing a reliable model for tensile strength prediction.
Finite Element Simulation of Stoneley Wave Propagation in Fracture Zones in Wells
Authors: Qi Xinghua , Wei Yuxuan , Wang Shimao , Wang Zhuwen
Published: November 2024

The formation and development of fractures increase reservoir heterogeneity and improve reservoir performance. Therefore, it is of great research value to accurately identify the development of fractures. In this paper, two- and three-dimensional models are constructed based on the finite element method and compared with the real axis integration method. The influence of different geometric parameters on the Stoneley wave amplitude is studied to assess the propagation of Stoneley waves in the fracture zone in the well. The results show a significant positive correlation between the width and number of fractures and the attenuation coefficient of Stoneley waves. The fracture angle has a negative correlation with the attenuation coefficient and lesser impact on Stoneley waves. In addition, Stoneley waves are less sensitive to changes in fracture location, while the sensitivity to fracture spacing is significant in the range of 50 cm to 75 cm. The main propagation depth of Stoneley waves occurs 20 cm from the wall of the well. Quantitative analyses of the fracture width, number, location, spacing, depth, and angle are conducted to determine the influence of the fracture parameters on the Stoneley wave attenuation coefficient, clarify Stoneley wave propagation in wells, and provide a theoretical basis for the accurate evaluation of fractures.
Deep Learning-Driven Virtual Furniture Replacement Using GANs and Spatial Transformer Networks
Authors: Vijaykumar Resmy , Ahmad Muneer , Ismail Maizatul Akmar , Ahmad Iftikhar , Noreen Neelum
Published: November 2024

This study proposes a Generative Adversarial Network (GAN)-based method for virtual furniture replacement within indoor scenes. The proposed method addresses the challenge of accurately positioning new furniture in an indoor space by combining image reconstruction with geometric matching through combining spatial transformer networks and GANs. The system leverages deep learning architectures like Mask R-CNN for executing image segmentation and generating masks, and it employs DeepLabv3+, EdgeConnect algorithms, and ST-GAN networks for carrying out virtual furniture replacement. With the proposed system, furniture shoppers can obtain a virtual shopping experience, providing an easier way to understand the aesthetic effects of furniture rearrangement without putting in effort to physically move furniture. The proposed system has practical applications in the furnishing industry and interior design practices, providing a cost-effective and efficient alternative to physical furniture replacement. The results indicate that the proposed method achieves accurate positioning of new furniture in indoor scenes with minimal distortion or displacement. The proposed system is limited to 2D front-view images of furniture and indoor scenes. Future work would involve synthesizing 3D scenes and expanding the system to replace furniture images photographed from different angles. This would enhance the efficiency and practicality of the proposed system for virtual furniture replacement in indoor scenes.
Innovative Approach to Detecting Autism Spectrum Disorder Using Explainable Features and Smart Web Application
Authors: Rony Mohammad Abu Tareq , Johora Fatama Tuz , Thalji Nisrean , Raza Ali , Fitriyani Norma Latif , Syafrudin Muhammad , Lee Seung Won
Published: November 2024

Autism Spectrum Disorder (ASD) is a complex developmental condition marked by challenges in social interaction, communication, and behavior, often involving restricted interests and repetitive actions. The diversity in symptoms and skill profiles across individuals creates a diagnostic landscape that requires a multifaceted approach for accurate understanding and intervention. This study employed advanced machine-learning techniques to enhance the accuracy and reliability of ASD diagnosis. We used a standard dataset comprising 1054 patient samples and 20 variables. The research methodology involved rigorous preprocessing, including selecting key variables through data mining (DM) visualization techniques including Chi-Square tests, analysis of variance, and correlation analysis, along with outlier removal to ensure robust model performance. The proposed DM and logistic regression (LR) with Shapley Additive exPlanations (DMLRS) model achieved the highest accuracy at 99%, outperforming state-of-the-art methods. eXplainable artificial intelligence was incorporated using Shapley Additive exPlanations to enhance interpretability. The model was compared with other approaches, including XGBoost, Deep Models with Residual Connections and Ensemble (DMRCE), and fast lightweight automated machine learning systems. Each method was fine-tuned, and performance was verified using k-fold cross-validation. In addition, a real-time web application was developed that integrates the DMLRS model with the Django framework for ASD diagnosis. This app represents a significant advancement in medical informatics, offering a practical, user-friendly, and innovative solution for early detection and diagnosis.
Aperiodic Optimal Chronotherapy in Simple Compartment Tumour Growth Models Under Circadian Drug Toxicity Conditions
Authors: Tzamarias Byron D. E. , Ballesta Annabelle , Burroughs Nigel John
Published: November 2024

Cancer cells typically divide with weaker synchronisation with the circadian clock than normal cells, with the degree of decoupling increasing with tumour maturity. Chronotherapy exploits this loss of synchronisation, using drugs with circadian-clock-dependent activity and timed infusion to balance the competing demands of reducing toxicity toward normal cells that display physiological circadian rhythms and of efficacy against the tumour. We analysed optimal chronotherapy for one-compartment nonlinear tumour growth models that were no longer synchronised with the circadian clock, minimising a cost function with a periodically driven running cost accounting for the circadian drug tolerability of normal cells. Using Pontryagin’s Minimum Principle (PMP), we show, for drugs that either increase the cell death rate or kill dividing cells, that optimal solutions are aperiodic bang–bang solutions with two switches per day, with the duration of the daily drug administration increasing as treatment progresses; for large tumours, optimal therapy can in fact switch mid treatment from aperiodic to continuous treatment. We illustrate this with tumours grown under logistic and Gompertz dynamics conditions; for logistic growth, we categorise the different types of solutions. Singular solutions can be applicable for some nonlinear tumour growth models if the per capita growth rate is convex. Direct comparison of the optimal aperiodic solution with the optimal periodic solution shows the former presents reduced toxicity whilst retaining similar efficacy against the tumour. We only found periodic solutions with a daily period in one-compartment exponential growth models, whilst models incorporating nonlinear growth had generic aperiodic solutions, and linear multi-compartments appeared to have long-period (weeks) periodic solutions. Our results suggest that chronotherapy-based optimal solutions under a harmonic running cost are not typically periodic infusion schedules with a 24 h period.
Probabilistic Linguistic TODIM Method with Probabilistic Linguistic Entropy Weight and Hamming Distance for Teaching Reform Plan Evaluation
Authors: Wu Wenshuai
Published: November 2024

In the context of the construction of new liberal arts, the integration and intersection of disciplines have become a new trend in the development of higher education. How to promote the teaching reform of big data technology and application courses in the new liberal arts construction scenario has become an important issue in enhancing students’ digital talent literacy and social adaptability. In this study, an extended probabilistic linguistic TODIM (an acronym in Portuguese for interactive multi-criteria decision making) with probabilistic linguistic entropy weight and Hamming distance is presented for teaching reform plan evaluation for the core course “big data technology and applications” in the digital economy major. Firstly, probabilistic linguistic entropy weight, based on the entropy of the additive linguistic term set, is applied to generate weight information. Secondly, parameter sensitivity analysis is carried out to prove the stabilization and effectiveness of the extended TODIM approach. Thirdly, this extended approach can integrate the psychological factors and cognitive behaviors of decision-makers for effectively responding to education management in the new liberal arts construction scenario. Finally, a case study on teaching reform plan evaluation is carried out, and a comparative analysis with different criteria weights and different methods is conducted to verify the extended approach. The results indicate that the extended approach can provide an effective technical tool for scientific decision-making, especially in the teaching reform plan evaluation scenario in order to promote high-quality development of education.
Degree-Constrained Steiner Problem in Graphs with Capacity Constraints
Authors: Molnar Miklos
Published: November 2024

The degree-constrained Steiner problem in graphs is well known in the literature. In an undirected graph, positive integer degree bounds are associated with nodes and positive costs with the edges. The goal is to find the minimum cost tree spanning a given node set while respecting the degree bounds. As it is known, finding a tree satisfying the constraints is not always possible. The problem differs when the nodes can participate multiple times in the coverage and the constraints represent a limited degree (a capacity) for each occurrence of the nodes. The optimum corresponds to a graph-related structure, i.e., to a hierarchy. Finding the solution to this particular Steiner problem is NP-hard. We investigate the conditions of its existence and its exact computation. The gain of the hierarchies is demonstrated by solving ILPs to compute hierarchies and trees. The advantages of the spanning hierarchies are conclusive: (1) spanning hierarchies can be found in some cases where spanning trees matching the degree constraints do not exist; (2) the cost of the hierarchy can be lower even if the Steiner tree satisfying the constraints exists.
Resolving Contrast and Detail Trade-Offs in Image Processing with Multi-Objective Optimization
Authors: Molina-Pérez Daniel , Rojas-López Alam Gabriel
Published: November 2024

This article addresses the complex challenge of simultaneously enhancing contrast and detail in an image, where improving one property often compromises the other. This trade-off is tackled using a multi-objective optimization approach. Specifically, the proposal’s model integrates the sigmoid transformation function and unsharp masking highboost filtering with the NSGA-II algorithm. Additionally, a posterior preference articulation is introduced to select three key solutions from the Pareto front: the maximum contrast solution, the maximum detail solution, and the knee point solution. The proposed technique is evaluated on a range of image types, including medical and natural scenes. The final solutions demonstrated significant superiority in terms of contrast and detail compared to the original images. The three selected solutions, although all are optimal, captured distinct characteristics within the images, offering different solutions according to field preferences. This highlights the method’s effectiveness across different types and enhancement requirements and emphasizes the importance of the proposed preferences in different contexts.
Marine Algal Toxins and Public Health: Insights from Shellfish and Fish, the Main Biological Vectors
Authors: Yuan Kuan-Kuan , Li Hong-Ye , Yang Wei-Dong
Published: November 2024

Exposure to toxigenic harmful algal blooms (HABs) can result in widely recognized acute poisoning in humans. The five most commonly recognized HAB-related illnesses are diarrhetic shellfish poisoning (DSP), paralytic shellfish poisoning (PSP), amnesic shellfish poisoning (ASP), neurotoxic shellfish poisoning (NSP), and ciguatera poisoning (CP). Despite being caused by exposure to various toxins or toxin analogs, these clinical syndromes share numerous similarities. Humans are exposed to these toxins mainly through the consumption of fish and shellfish, which serve as the main biological vectors. However, the risk of human diseases linked to toxigenic HABs is on the rise, corresponding to a dramatic increase in the occurrence, frequency, and intensity of toxigenic HABs in coastal regions worldwide. Although a growing body of studies have focused on the toxicological assessment of HAB-related species and their toxins on aquatic organisms, the organization of this information is lacking. Consequently, a comprehensive review of the adverse effects of HAB-associated species and their toxins on those organisms could deepen our understanding of the mechanisms behind their toxic effects, which is crucial to minimizing the risks of toxigenic HABs to human and public health. To this end, this paper summarizes the effects of the five most common HAB toxins on fish, shellfish, and humans and discusses the possible mechanisms.
Association of Oral Tobacco-Free Nicotine Delivery Product with Acute Renal Tubular Necrosis
Authors: Acharya Ratna , Clapp William , Upadhyay Kiran
Published: November 2024

Usage of novel non-tobacco oral nicotine delivery products (ONDPs) has been increasing among adolescents in the United States. It is presumed that they are less toxic than their tobacco-containing counterparts, but that has not been examined in controlled studies. Most of the studies have focused on non-renal manifestations of tobacco consumption via different means. The renal manifestations of non-tobacco ONDPs are not very well known, especially in immunocompromised patients. A 19-year-old male transplant recipient presented with flank pain and a few days’ history of intake of ZYNR pouches. Immunosuppression was with tacrolimus, mycophenolate, and steroids. Baseline serum creatinine was 1.1–1.3 mg/dL. Laboratory evaluation showed elevated C-reactive protein, increased serum creatinine and blood urea nitrogen, leukocytosis, neutrophilia, and increased lactate dehydrogenase (LDH). Infectious disease work-up was negative. A kidney transplant biopsy showed severe acute tubular injury/necrosis (ATN) without evidence of rejection. Donor-specific antibodies were negative. Other etiologies of hemolysis were negative. He did not require renal replacement therapy. Kidney function and LDH improved gradually. The most recent follow-up eight months after presentation showed a serum creatinine level of 2.6 mg/dL with stable electrolytes, with eGFR of 35 mL/min/1.73 m2. Here, we describe a 19-year-old adolescent with a kidney transplant who sustained ATN leading to advanced chronic disease apparently following the usage of non-tobacco ONDP. Further larger studies are needed to study ATN as a possible renal manifestation of these next-generation products to raise awareness among the public.
Can Ileostomy Reversal Be Safely Performed by Surgical Residents?
Authors: Kisielewski Michał , Pisarska-Adamczyk Magdalena , Dowgiałło-Gornowicz Natalia , Nawacki Łukasz , Serednicki Wojciech , Wierdak Mateusz , Wilczek Jerzy , Safiejko Kamil , Juchimiuk Marcin , Domurat Marian , Pierko Jacek , Mucha Mateusz , Fiedorowicz Wojciech , Wysocki Michał , Ladziński Maurycy , Zdrojewski Michał , Sachańbiński Tomasz , Wojewoda Tomasz , Chochla Victoria , Tkaczyński Karol , Jankowski Michał , Wysocki Wojciech M.
Published: November 2024

Background and Objectives: The growing number of colorectal cancer patients has highlighted the importance of surgical education in colorectal surgery. Despite the negative impact of the COVID-19 pandemic on surgical training, recent changes in the Polish surgical training program have increased the number of intestinal procedures required to be completed by residents. This study aims to assess the safety of ileostomy reversal procedures performed by surgical residents. Materials and Methods: A multicenter prospective cohort study, the LILEO study, was conducted from October 2022 until December 2023 across 20 Polish surgical departments. The study included 199 patients who underwent ileostomy reversal and were divided into two groups: 139 patients operated by specialist surgeons and 60 patients operated by surgical residents. The primary outcomes measured were postoperative complications, length of hospital stay (LOS), and 30-day reoperation rate. Secondary outcomes included the severity of perioperative complications assessed using the Clavien–Dindo classification and a focused analysis of loop ileostomy reversal outcomes. Results: The median LOS was significantly shorter in the resident group (5.5 days vs. 6 days, p < 0.05). Although the overall complication rate was lower in the resident group (21.7% vs. 33.1% in the specialist surgeon group), this difference was not statistically significant (p = 0.105). The 30-day reoperation rate was 3.3% in the resident group and 8.6% in the specialist surgeon group (p = 0.179). In terms of severity, minor complications (Clavien–Dindo grades 1 and 2) were more common in the specialist group (p < 0.05). The analysis of loop ileostomy reversals revealed no significant differences in postoperative outcomes between the two groups. Conclusions: Ileostomy reversal procedures performed by surgical residents under supervision are safe and feasible, with outcomes comparable to those performed only by specialist surgeons. These findings support ileostomy reversal as a valuable procedure for developing surgical residents’ skills and do not negatively affect postoperative outcomes.
Obstetric Brachial Plexus Palsy and Functional Implications: Which Joint in the Upper Extremity Is More Closely Associated?
Authors: Utku Umut Gülsena , Hoşbay Zeynep , Tanrıverdi Müberra , Yılmaz Güleser Güney , Altaş Okyar , Korucu Alperen , Aydın Atakan
Published: November 2024

Background and Objectives: The objective of this study is to examine the correlation between the active range of motion (ROM) of the affected upper extremity and functional capacity in children with Obstetric Brachial Plexus Palsy (OBPP) who have undergone the modified Hoffer tendon transfer technique. Materials and Methods: The study cohort comprised 52 children with OBPP, aged 4–14 years, who had undergone a shoulder tendon transfer. The ROM was quantified using a goniometer, while functionality was evaluated through the administration of the Brachial Plexus Outcome Measure (BPOM). Results: The study identified significant correlations between the shoulder ROM and the Brachial Plexus Outcome Measure (BPOM). Specifically, shoulder flexion (p = 0.017; r = 0.351) was positively associated with shoulder functionality, while shoulder internal rotation (p = 0.001; r = 0.481) was linked to appearance scores. A significant negative relationship was observed between elbow extension (p < 0.001; r = −0.512) and elbow and forearm activities. Conclusions: The study highlights the necessity of assessing both joint range of motion and body perception for effective treatment and follow-up, to improve the functionality and quality of life for children with OBPP.
Beta-Blocker Use in Patients Undergoing Non-Cardiac Surgery: A Systematic Review and Meta-Analysis
Authors: Herrera Hernández Doménica , Abreu Bárbara , Xiao Tania Siu , Rojas Andreina , Romero Kevin López , Contreras Valentina , Nogueyra Sol Villa , Sosa Zulma , Alvarez Samantha M. , Sánchez Cruz Camila , Calderón Martinez Ernesto
Published: November 2024

Background: The use of beta-blockers in the perioperative period has been widely investigated due to their potential to reduce the risk of major adverse cardiovascular and cerebrovascular events (MACCE) and mortality; yet their overall impact on various postoperative outcomes remains debated. This study constitutes a systematic review and meta-analysis of the impact of beta-blockers on mortality, MI, stroke, and other adverse effects such as hypotension and bradycardia in patients undergoing non-cardiac surgery. Methods: A comprehensive systematic review and meta-analysis were conducted according to PRISMA 2020 guidelines. Searches were performed across PubMed, Cochrane, Web of Science, Scopus, EMBASE, and CINAHL databases; we included randomized controlled trials and cohort and case-control studies published from 1999 to 2024. Results: This meta-analysis included data from 28 studies encompassing 1,342,430 patients. Perioperative beta-blockers were associated with a significant increase in stroke risk (RR 1.42, 95% CI: 1.03 to 1.97, p = 0.03, I2 = 62%). However, no statistically significant association was found between beta-blocker use and mortality (RR 0.62, 95% CI: 0.38 to 1.01, p = 0.05, I2 = 100%). Subgroup analyses revealed a protective effect on mortality for patients with high risks, such as patients with a history of atrial fibrillation, chronic heart failure, and other arrhythmias. For myocardial infarction (RR 0.82, 95% CI: 0.53 to 1.28, p = 0.36, I2 = 86%), a reduction in events was observed in the subgroup of randomized controlled trials. Beta-blockers significantly increased the risk of hypotension (RR 1.46, 95% CI: 1.26 to 1.70, p < 0.01, I2 = 25%) and bradycardia (RR 2.26, 95% CI: 1.37 to 3.74, p < 0.01, I2 = 64%). Conclusions: Perioperative beta-blockers show increasing rates of stroke events following non-cardiac surgery but do not significantly impact the incidence of MI or mortality. The increased risks of hypotension and bradycardia necessitate careful patient selection and monitoring. Future research should aim to refine patient selection criteria and optimize perioperative management to balance the benefits and risks of beta-blocker use in surgical settings.
Computational Fluid Dynamics Modeling of Pressure-Retarded Osmosis: Towards a Virtual Lab for Osmotic-Driven Process Simulations
Authors: Mohammadi Amin Meisam , Krühne Ulrich
Published: November 2024

Pressure-Retarded Osmosis (PRO) is an osmotically driven membrane-based process that has recently garnered significant attention from researchers due to its potential for clean energy harvesting from salinity gradients. The complex interactions between mixed-mode channel flows and osmotic fluxes in real PRO membrane modules necessitate high-fidelity modeling approaches. In this work, an efficient CFD framework is developed for the 3D simulation of osmotically driven membrane processes. This approach is based on a two-way coupling between a CFD solver, which captures external concentration polarization (ECP) effects, and an analytical representation of internal concentration polarization (ICP). Consequently, the osmotic water flux and reverse salt flux (RSF) can be accurately determined, accounting for all CP effects without any limitations on the geometrical complexity of the membrane chamber or its flow mode/regime. The proposed model is validated against experimental data, showing good agreement across various PRO case studies. Additionally, the model’s flexibility to simulate other types of osmotically driven processes such as forward osmosis (FO) is examined. Thus, the contributions of ECP and ICP effects in local osmotic pressure drop along the membrane chamber are comprehensively compared for FO and PRO modes. Finally, the capability of the CFD model to simulate a lab-scale PRO module is demonstrated across a range of Reynolds numbers from low-speed laminar up to turbulent flow regimes.
Performance of the GH4169 Joint Using a Novel Ni-Based Amorphous Brazing Filler Metal
Authors: Yang Xiaohong , Zhu Kaitao , Huang Dan , Yang Lin
Published: November 2024

A novel Ni-Cr-Si-B filler metal (JNi-5) was designed and further fabricated into the amorphous brazing filler metal for joining the GH4169 alloy. The effect of brazing temperature on the microstructure and mechanical properties of GH4169 joints was investigated. The typical microstructure of the joint at 1030 °C is composed of four specific zones: the base metal (BM), heat-affected zone (HAZ), isothermal solidification zone (ISZ), and athermal solidification zone (ASZ). The typical microstructure of the joint is GH4169/(Nb, Mo)-rich boride+(Cr, Nb, Mo)-rich boride/γ(Ni)/Ni-rich boride+γ(Ni)/γ(Ni)/(Cr, Nb, Mo)-rich boride+(Nb, Mo)-rich boride/GH4169. As the temperature increased, the HAZ continued to widen and the ASZ depleted at 1090 °C and 1120 °C. Additionally, the borides within the HAZ coarsened at temperatures of 1090 °C and 1120 °C. At 1030 °C, the fracture path is in the ASZ, and the existence of the brittle phase in the ASZ provides the potential origin for crack growth. The fracture mode is a quasi-cleavage fracture. At 1060 °C, 1090 °C, and 1120 °C, the fracture behavior mainly happened in the HAZ, and the existence of borides in the HAZ provides the potential origin for crack growth. Namely, the shear strength of joints was principally dominated by the brittle precipitations in the HAZ. The fracture mode of these joints is the hybrid ductile. At 1060 °C, the shear strength of the obtained joint is the highest value (693.78 MPa) due to the volume fraction increase in the Ni-based solid solution. Finally, the optimized brazing parameter of 1060 °C/10 min was determined, and the corresponding highest shear strength of 693.78 MPa was obtained owing to the increased content of the Ni-based solid solution in the joint.
Recycling Li-Ion Batteries via the Re-Synthesis Route: Improving the Process Sustainability by Using Lithium Iron Phosphate (LFP) Scraps as Reducing Agents in the Leaching Operation
Authors: Pagnanelli Francesca , Altimari Pietro , Colasanti Marco , Coletta Jacopo , D’Annibale Ludovica , Mancini Alyssa , Russina Olga , Schiavi Pier Giorgio
Published: November 2024

The development of hydrometallurgical recycling processes for lithium-ion batteries is challenged by the heterogeneity of the electrode powders recovered from end-of-life batteries via physical methods. These electrode materials, known as black mass, vary in composition, containing differing amounts of nickel, manganese, and cobalt (NMC), as well as other chemicals, such as lithium iron phosphate (LFP). This study presents the results of the hydrometallurgical treatment of mixed NMC and LFP black masses aimed at creating flexible recycling processes. This approach leverages the reducing power of LFP to optimize the leach liquor composition for re-synthesizing NMC precursors. In particular, the leaching conditions were optimized based on the LFP content in the solid feed to maximize the extraction of key metals (Ni, Mn, Co, and Li). The leaching solid residue, graphite, was treated and characterized as a secondary raw material for new anode preparation. Iron phosphate was recovered by increasing the pH of the leach liquor, and the NMC precursors were obtained via coprecipitation. This process achieved a recycling rate of 51%, based on the black mass input and the mass of recovered elements in the output products. Additionally, substituting LFP scraps as the reducing agent in place of H2O2 reduced the recycling process’s environmental impact by avoiding 1.7 tons of CO2-equivalent emissions per ton of NMC black mass.
Evaluation of Different Blending Methods to Obtain Copper Composites with Graphene Oxide
Authors: Souza Caique Movio Pereira de , Cunali Junior José Ricardo Cabau , da Silva Marcio Rodrigues , dos Santos Vinicius Torres , Lobo Flavia Gonçalves , dos Santos Givanildo Alves , Almeida Gisele Fabiane Costa , Couto Antonio Augusto , Massi Marcos
Published: November 2024

This study evaluated mixing methods for producing graphene oxide-reinforced copper matrix composites aiming for a better dispersion of graphene oxide in the composite, using powder metallurgy techniques. The compacted specimens were prepared by four different mixing processes that employed either a mechanical stirrer, rotary evaporator, tip ultrasound, or ultrasound process followed by mechanical stirring. Characterizations were performed using optical microscopy, scanning electron microscopy, X-ray diffraction, Raman spectroscopy, transmission electron microscopy, compression tests, Vickers microhardness, and electrical conductivity measurements. The results indicate that the combined method yields a more homogeneous microstructure and superior mechanical properties, while electrical conductivity was maintained at a level higher than that achieved by the other methods.
Insights into the Influence of Tensile and Compressive Strain on the Microstructure and Corrosion Performance of 304 L Stainless Steel
Authors: Chu Tongjiao , Xu Wenjing , Bai Minghan
Published: November 2024

The effects of tensile and compressive strain, originating from U-bent deformation, on the corrosion behavior of 304 L stainless steel were studied via analyses of the material’s microstructure and electrochemistry in a 3.5% NaCl solution. In contrast with the as-received 304 L steel with the largest grain size, the deformed 304 L material with a small grain size had the lowest number of Σ3 grain boundaries and an overall low fraction, with special low-Σ values (≤29). Moreover, the dislocation density increased to 1.13 × 1016/m2 and 1.4 × 1016/m2 for the tensile and compressive 304 L steel testing, respectively. The decrease in Epit and increase in ipit suggested that there was a decrease in anti-corrosion properties due to tensile and compressive deformation. This might be attributed to the higher plastic strain found in deformed 304 L steel, which can induce the rupture of passive film and have a harmful influence on corrosion resistance. In particular, the compressive 304 L steel with the highest content of deformed grains (42.12%) promoted the formation of microgalvanic cells, thereby facilitating the nucleation of pits. Then, these pits grew to a large size through grain shedding. Subsequently, massive chloride ions were generated during metal dissolution and diffused along grain boundaries, which promoted the initiation and propagation of intergranular corrosion cracks.
Improvements in Insulin Resistance and Glucose Metabolism Related to Breastfeeding Are Not Mediated by Subclinical Inflammation
Authors: Oliveira Julia Martins de , Dualib Patrícia Médici , Ferraro Alexandre Archanjo , Mattar Rosiane , Dib Sérgio Atala , Almeida-Pititto Bianca de
Published: November 2024

Background: Lactation is known to improve insulin resistance, but this phenomenon remains poorly understood. Our goal was to evaluate whether subclinical inflammation could mediate the association between breastfeeding (BF) and improvement in glucose metabolism and markers of insulin resistance (MIRs) in the postpartum. Methods: A total of 95 adult women (≥18 years) with a BMI ≥ 25 kg/m2 from the outpatient clinic of the Federal University of São Paulo were followed from early pregnancy until 60 to 180 days postpartum. The patients were divided based on their BF status: BF and non-BF groups. A latent variable termed SubInf was created incorporating inflammation-related biomarkers: adiponectin, E-selectin, branched-chain amino acids, zonulin, copeptin, and lipopolysaccharides. The association of BR with MIRs in the postpartum was evaluated through linear regression analysis, and mediation analysis was performed to evaluate the role of SubInf in this association. Results: The groups were similar regarding gestational diabetes mellitus (GDM) prevalence, pre-gestational BMI, caloric intake, physical activity, and postpartum weight loss. The BF group presented lower levels of triglycerides (TGs), fasting glucose, fasting insulin, TG/HDLcholesterol ratio (TG/HDL), TyG index, and HOMA-IR compared to the non-BF group. A linear regression analysis adjusted for scholarity, parity, pre-gestational BMI, GDM, weight gain during pregnancy, and mode of delivery revealed an inverse association between BF and fasting glucose [−6.30 (−10.71 to −1.89), p = 0.005), HOMA-IR [−0.28 (−0.50 to −0.05), p = 0.017], TyG index [−0.04 (−0.06 to −0.01), p = 0.002], and TG/HDL ratio [−0.23 (−0.46 to −0.01), p = 0.001]. In the mediation analysis, SubInf did not mediate the indirect effect of BF on MIRs. Conclusions: In overweight and obese women, an association between BF and improvement in MIRs in the postpartum was seen, corroborating that BF should be stimulated, especially in these cardiometabolic high-risk women. Subclinical inflammation did not seem to mediate this association.
Extraction Methods for Brain Biopsy NMR Metabolomics: Balancing Metabolite Stability and Protein Precipitation
Authors: Xiong Wenzheng , Zirpel Florian , Cader M. Zameel , Anthony Daniel C. , Probert Fay
Published: November 2024

Background/Objectives: Metabolic profiling of tissue samples via liquid-state nuclear magnetic resonance (NMR) requires the extraction of polar metabolites in a suitable deuterated solvent. Such methods often prioritise metabolite recovery over protein removal due to the relatively low sensitivity of NMR metabolomics and the routine use of methods able to supress residual protein signals. However, residual protein may impact metabolite integrity and the metabolite stability after NMR sample preparation is often overlooked. This study aimed to investigate the effect of residual protein contamination in rodent brain extracts and identify a reproducible extraction method that optimises metabolite recovery while ensuring sample stability. Methods: The performance of acetonitrile/water (50–100% MeCN), methanol/water (50–100% MeOH), and methanol/water/chloroform (MeOH/H2O/CHCl3) were assessed for extraction efficiency, reproducibility, residual protein contamination, and metabolite stability up to eight hours post NMR sample preparation. Results: Aspartate and glutamate deuteration were observed in 50% MeCN, 50% MeOH, and 67% MeOH extractions along with the conversion of N-acetyl aspartate to aspartate and acetate in 50% MeCN and 50% MeOH extractions. Both observations correlated with residual protein contamination and, thus, are a result of inadequate protein precipitation, as confirmed by ultrafiltration. MeOH/H2O/CHCl3 extraction preserved the stability of these metabolites while maintaining good extraction efficiency and reproducibility. Conclusions: Thus, we recommend MeOH/H2O/CHCl3 extraction for untargeted brain NMR metabolic profiling due to its effective protein precipitation and reliable performance. Nonetheless, the performance of detecting metabolites prone to oxidation such as ascorbate and glutathione is not improved by this method.
Phenolic Metabolites Protocatechuic Acid and Vanillic Acid Improve Nitric Oxide Bioavailability via the Akt-eNOS Pathway in Response to TNF-α Induced Oxidative Stress and Inflammation in Endothelial Cells
Authors: Festa Joseph , Hussain Aamir , Al-Hareth Zakia , Bailey Stephen J. , Singh Harprit , Da Boit Mariasole
Published: November 2024

Background/Objectives: Reduced nitric oxide (NO) bioavailability secondary to excess-superoxide-driven oxidative stress is central to endothelial dysfunction. Previous studies suggest that phenolic metabolites may improve NO bioavailability, yet limited research is available in response to an inflammatory mediator. Therefore, we assessed the effects of cyanidin-3-glucoside (C3G) and its phenolic metabolites protocatechuic acid (PCA) and vanillic acid (VA) on NO bioavailability in a TNF-α induced inflammatory environment. Methods: Primary human umbilical vein endothelial cells (HUVECs) were supplemented with either C3G, PCA, or VA at 1 μM for 24 h before being stimulated with TNF-α 20 ng/mL for an additional 24 h. Measurements included cell viability, apoptosis, reactive oxygen species (ROS), nitrite concentrations, and endothelial nitric oxide synthase (eNOS) and Akt at the mRNA and protein level. Results: Phenolic metabolites did not increase the eNOS expression or nitrite levels in the unstimulated environment; rather, the metabolites mediated NO bioavailability in response to TNF-α induced oxidative stress, with increased viability, eNOS mRNA, phosphorylation, and nitrite levels. Conclusions: Phenolic metabolites, in the presence of TNF-α, can improve NO bioavailability at physiologically relevant concentrations via the Akt-eNOS pathway. This demonstrates that the induction of inflammation is a prerequisite for phenolic metabolites to promote protective properties in endothelial cells by activating the Akt-eNOS pathway.
Phenotypic Timeline Kinetics, Integrative Networks, and Performance of T- and B-Cell Subsets Associated with Distinct Clinical Outcome of Severe COVID-19 Patients
Authors: de Oliveira Gabriela , Costa-Rocha Ismael Artur , Oliveira-Carvalho Nani , dos Santos Tâmilla Mayane Alves Fidelis , Campi-Azevedo Ana Carolina , Peruhype-Magalhães Vanessa , Miranda Vitor Hugo Simões , Prado Roberta Oliveira , Pereira Agnes Antônia Sampaio , Alves Clarice Carvalho , Brito-de-Sousa Joaquim Pedro , Reis Laise Rodrigues , Costa-Pereira Christiane , da Mata Camila Pacheco Silveira Martins , Almeida Vanessa Egídio Silveira , dos Santos Liliane Martins , Almeida Gregório Guilherme , Antonelli Lis Ribeiro do Valle , Coelho-dos-Reis Jordana Grazziela , Teixeira-Carvalho Andréa , Martins-Filho Olindo Assis
Published: November 2024

The present study aimed to evaluate the kinetics of the phenotypic profile and integrative networks of T/B-cells in severe COVID-19 patients, categorized according to disease outcome, during the circulation of the B.1.1.28 and B.1.1.33 SARS-CoV-2 strains in Brazil. Peripheral blood obtained at distinct time points (baseline/D0; D7; D14-28) was used for ex vivo flow cytometry immunophenotyping. The data demonstrated a decrease at D0 in the frequency of CD3+ T-cells and CD4+ T-cells and an increase in B-cells with mixed activation/exhaustion profiles. Higher changes in B-cell and CD4+ T-cells at D7 were associated with discharge/death outcomes, respectively. Regardless of the lower T/B-cell connectivity at D0, distinct profiles from D7/D14-28 revealed that, while discharge was associated with increasing connectivity for B-cells, CD4+ and CD8+ T-cells death was related to increased connectivity involving B-cells, but with lower connections mediated by CD4+ T-cells. The CD4+CD38+ and CD8+CD69+ subsets accurately classified COVID-19 vs. healthy controls throughout the kinetic analysis. Binary logistic regression identified CD4+CD107a+, CD4+T-bet+, CD8+CD69+, and CD8+T-bet+ at D0 and CD4+CD45RO+CD27+ at D7 as subsets associated with disease outcomes. Results showed that distinct phenotypic timeline kinetics and integrative networks of T/B-cells are associated with COVID-19 outcomes that may subsidize the establishment of applicable biomarkers for clinical/therapeutic monitoring.
Real-Life Diagnostic Accuracy and Clinical Utility of Hepatitis B Virus (HBV) Nucleic Acid Testing Using the GeneXpert Point-of-Care Test System from Fresh Plasma and Dry Blood Spot Samples in The Gambia
Authors: Ceesay Amie , Drammeh Sainabou , Ndow Gibril , Jallow Alpha Omar A. , Nyang Haddy , Bittaye Baboucarr , Mendy Francis S. , Secka Ousman , D’Alessandro Umberto , Shimakawa Yusuke , Vo-Quang Erwan , Testoni Barbara , Thursz Mark , Lemoine Maud , Chemin Isabelle
Published: November 2024

The GeneXpert HBV Viral Load test is a simplified tool to scale up screening and HBV monitoring in resource-limited settings, where HBV is endemic and where molecular techniques to quantify HBV DNA are expensive and scarce. However, the accuracy of field diagnostics compared to gold standard assays in HBV-endemic African countries has not been well understood. We aim to validate the diagnostic performance of the GeneXpert HBV Viral Load test in freshly collected and stored plasma and dried blood spot (DBS) samples to assess turn-around-time (TAT) for sample processing and treatment initiation, to map GeneXpert machines and to determine limitations to its use in The Gambia. Freshly collected paired plasma and DBS samples (n = 56) were analyzed by the GeneXpert test. Similarly, stored plasma and DBS samples (n = 306, n = 91) were analyzed using the GeneXpert HBV test, in-house qPCR and COBAS TaqMan Roche. The correlation between freshly collected plasma and DBS is r = 0.88 with a mean bias of −1.4. The GeneXpert HBV test had the highest quantifiable HBV DNA viremia of 81.4% (n = 249/306), and the lowest was detected by in-house qPCR at 37.9% (n = 116/306) for stored plasma samples. Bland–Altman plots show strong correlation between GeneXpert and COBAS TaqMan and between GeneXpert and in-house qPCR with a mean bias of +0.316 and −1.173 log10 IU/mL, respectively. However, paired stored plasma and DBS samples had a lower mean bias of 1.831 log10 IU/mL, which is almost significant (95% limits of agreement: 0.66–3.001). Patients (n = 3) were enrolled in the study within a TAT of 6 days. The GeneXpert HBV test displayed excellent diagnostic accuracy by detecting HBV viremia in less than 10 IU/mL.