bluuebunny/crossref_metadata_2025 huggingface dataset:
Single-Machine Rescheduling with Rejection and an Operator No-Availability Period
Authors: Wu Guanghua , Zhu Hongli
Published: November 2024

In this paper, we investigate a rescheduling problem with rejection and an operator non-availability period on a single machine. An optimal original schedule with the objective of minimizing the total weighted completion time has been made in a deterministic production scheduling system without an unavailable interval. However, prior to the start of formal job processing, a time interval becomes unavailable due to the operator. No jobs can start or complete in the interval; nonetheless, a job that begins prior to this interval and finishes afterward is possible (if there is such a job, we call it a crossover job). In order to deal with the operator non-availability period, job rejection is allowed. Each job is either accepted for processing or rejected by paying a rejection cost. The planned original schedule is required to be rescheduled. The objective is to minimize the total weighted completion time of the accepted jobs plus the total penalty of the rejected jobs plus the weighted maximum tardiness penalty between the original schedule and the new reschedule. We present a pseudo-polynomial time dynamic programming exact algorithm and subsequently develop it into a fully polynomial time approximation scheme.
Dichotomy Law for a Modified Shrinking Target Problem in Beta Dynamical System
Authors: Wang Wenya , Guo Zhongkai
Published: November 2024

Let φ:N→(0,1] be a positive function. We consider the size of the set Ef(φ):={β>1:|Tβn(x)−f(β)|<φ(n)i.o.n}, where “i.o.n” stands for “infinitely often”, and f:(1,∞)→[0,1] is a Lipschitz function. For any x∈(0,1], it is proved that the Hausdorff measure of Ef(φ) fulfill a dichotomy law according to lim supn→∞logφ(n)n=−∞ or not, where Tβ is the β-transformation. In ergodic theory, the phenomenon of shrinking targets is crucial for understanding the long-term behavior of systems. By studying the shrinking target problem of the β dynamical system, we can reveal the relationship between randomness and determinism, which is significant for constructing more complex mathematical models. Moreover, there is a close connection between the β transformation and number theory. Investigating the contraction target problem helps uncover new properties and patterns in number theory, advancing the development of this field. In this work, we establish a significant relationship between the decay rate of the positive function φ(n) and the structural properties of the set Ef(φ). Specifically, we show that: The Hausdorff dimension of Ef(φ) either vanishes or is positive based on the behavior of φ(n) as n approaches infinity. The establishment of this dichotomy can help us more effectively understand the geometric characteristics and dynamical behavior of the system, thereby aiding our acceptance and comprehension of complex theories. Researching this shrinking target problem can help us uncover new properties in number theory, leading to a better understanding of the structure of numbers and promoting the development of related fields in number theory.
Excessive External Borrowing in China: Evidence from a Nonparametric Threshold Regression Model with Fixed Effects
Authors: Tian Jinjing , Wang Taining , Yao Feng
Published: November 2024

We investigated the excessive external financing problem in Chinese industrial firms by examining the potential threshold effect of the leverage ratio on the total factor productivity of firms. We hypothesized the existence of a turning point in leverage ratio at which the productivity of these firms is maximized, and this point may vary by firm ownership type. To test our hypotheses, we proposed a nonparametric panel threshold regression model. From a modeling perspective, our approach contributes to the literature by allowing the threshold variable to be endogenous, accounting for unobserved firm heterogeneities, and imposing no restrictions on the functional form of regression. We employed a two-step estimation procedure, first estimating the threshold using an extreme kernel estimator and then conducting local linear regression based on the estimated threshold. We obtained standard errors via bootstrapping and demonstrated the favorable numerical performance of our estimator through simulation studies. Consistent with our hypotheses, we found that excessive leverage relative to the identified turning point significantly restrains productivity growth. Additionally, the estimated turning point varies by ownership type, particularly in state-owned enterprises (SOEs), where leverage exceeding the threshold negatively impacts productivity. Consequently, regions with a higher concentration of SOEs experience stagnant productivity growth. Our results were statistically supported by nonparametric tests and remained consistent when using leverage growth rate as an alternative measure of external financing.
Investigating the Predominance of Large Language Models in Low-Resource Bangla Language over Transformer Models for Hate Speech Detection: A Comparative Analysis
Authors: Faria Fatema Tuj Johora , Baniata Laith H. , Kang Sangwoo
Published: November 2024

The rise in abusive language on social media is a significant threat to mental health and social cohesion. For Bengali speakers, the need for effective detection is critical. However, current methods fall short in addressing the massive volume of content. Improved techniques are urgently needed to combat online hate speech in Bengali. Traditional machine learning techniques, while useful, often require large, linguistically diverse datasets to train models effectively. This paper addresses the urgent need for improved hate speech detection methods in Bengali, aiming to fill the existing research gap. Contextual understanding is crucial in differentiating between harmful speech and benign expressions. Large language models (LLMs) have shown state-of-the-art performance in various natural language tasks due to their extensive training on vast amounts of data. We explore the application of LLMs, specifically GPT-3.5 Turbo and Gemini 1.5 Pro, for Bengali hate speech detection using Zero-Shot and Few-Shot Learning approaches. Unlike conventional methods, Zero-Shot Learning identifies hate speech without task-specific training data, making it highly adaptable to new datasets and languages. Few-Shot Learning, on the other hand, requires minimal labeled examples, allowing for efficient model training with limited resources. Our experimental results show that LLMs outperform traditional approaches. In this study, we evaluate GPT-3.5 Turbo and Gemini 1.5 Pro on multiple datasets. To further enhance our study, we consider the distribution of comments in different datasets and the challenge of class imbalance, which can affect model performance. The BD-SHS dataset consists of 35,197 comments in the training set, 7542 in the validation set, and 7542 in the test set. The Bengali Hate Speech Dataset v1.0 and v2.0 include comments distributed across various hate categories: personal hate (629), political hate (1771), religious hate (502), geopolitical hate (1179), and gender abusive hate (316). The Bengali Hate Dataset comprises 7500 non-hate and 7500 hate comments. GPT-3.5 Turbo achieved impressive results with 97.33%, 98.42%, and 98.53% accuracy. In contrast, Gemini 1.5 Pro showed lower performance across all datasets. Specifically, GPT-3.5 Turbo excelled with significantly higher accuracy compared to Gemini 1.5 Pro. These outcomes highlight a 6.28% increase in accuracy compared to traditional methods, which achieved 92.25%. Our research contributes to the growing body of literature on LLM applications in natural language processing, particularly in the context of low-resource languages.
Numerical Solution of Emden–Fowler Heat-Type Equations Using Backward Difference Scheme and Haar Wavelet Collocation Method
Authors: Alshehri Mohammed N. , Kumar Ashish , Goswami Pranay , Althobaiti Saad , Aljohani Abdulrahman F.
Published: November 2024

In this study, we introduce an algorithm that utilizes the Haar wavelet collocation method to solve the time-dependent Emden–Fowler equation. This proposed method effectively addresses both linear and nonlinear partial differential equations. It is a numerical technique where the differential equation is discretized using Haar basis functions. A difference scheme is also applied to approximate the time derivative. By leveraging Haar functions and the difference scheme, we form a system of equations, which is then solved for Haar coefficients using MATLAB software. The effectiveness of this technique is demonstrated through various examples. Numerical simulations are performed, and the results are presented in graphical and tabular formats. We also provide a convergence analysis and an error analysis for this method. Furthermore, approximate solutions are compared with those obtained from other methods to highlight the accuracy, efficiency, and computational convenience of this technique.
Optimizing Power Flow and Stability in Hybrid AC/DC Microgrids: AC, DC, and Combined Analysis
Authors: Meena Ghanshyam , Meena Veerpratap , Mathur Akhilesh , Singh Vinay Pratap , Azar Ahmad Taher , Hameed Ibrahim A.
Published: November 2024

A microgrid (MG) is a unique area of a power distribution network that combines distributed generators (conventional as well as renewable power sources) and energy storage systems. Due to the integration of renewable generation sources, microgrids have become more unpredictable. MGs can operate in two different modes, namely, grid-connected and islanded modes. MGs face various challenges of voltage variations, frequency deviations, harmonics, unbalances, etc., due to the uncertain behavior of renewable sources. To study the impact of these issues, it is necessary to analyze the behavior of the MG system under normal and abnormal operating conditions. Two different tools are used for the analysis of microgrids under normal and abnormal conditions, namely, power flow and short-circuit analysis, respectively. Power flow analysis is used to determine the voltages, currents, and real and reactive power flow in the MG system under normal operating conditions. Short-circuit analysis is carried out to analyze the behavior of MGs under faulty conditions. In this paper, a review of power flow and short-circuit analysis algorithms for MG systems under two different modes of operation, grid-connected and islanded, is presented. This paper also presents a comparison of various power flow as well as short-circuit analysis techniques for MGs in tabular form. The modeling of different components of MGs is also discussed in this paper.
Polynomial Approximation over Arbitrary Shape Domains
Authors: Mahtabi Mohammad J. , Ghasemi Arash , Ghasemi Amirehsan , Newman James C.
Published: November 2024

In spectral/finite element methods, a robust and stable high-order polynomial approximation method for the solution can significantly reduce the required number of degrees of freedom (DOFs) to achieve a certain level of accuracy. In this work, a closed-form relation is proposed to approximate the Fekete points (AFPs) on arbitrary shape domains based on the singular value decomposition (SVD) of the Vandermonde matrix. In addition, a novel method is derived to compute the moments on highly complex domains, which may include discontinuities. Then, AFPs are used to generate compatible basis functions using SVD. Equations are derived and presented to determine orthogonal/orthonormal modal basis functions, as well as the Lagrange basis. Furthermore, theorems are proved to show the convergence and accuracy of the proposed method, together with an explicit form of the Weierstrass theorem for polynomial approximation. The method was implemented and some classical cases were analyzed. The results show the superior performance of the proposed method in terms of convergence and accuracy using many fewer DOFs and, thus, a much lower computational cost. It was shown that the orthogonal modal basis is the best choice to decrease the DOFs while maintaining a small Lebesgue constant when very high degree of polynomial is employed.
Anti-Obesity Effects of Sulphated Polysaccharides Derived from Marine Macro Algae or Seaweeds: A Systematic Review and Meta-Analysis
Authors: Magwaza S’thandiwe Nozibusiso , Chabalala Vunene Nkateko , Hlongwane Nothando Philile , Ismail Huda , Islam Md. Shahidul
Published: November 2024

Sulphated polysaccharides (SPs) are negatively charged compounds found in the cell wall of seaweeds or marine macro algae. These compounds exhibit a range of pharmacological activities, including anti-obesity effects. The aim of this systematic review as well as meta-analysis was to assess the potentials of seaweed-derived SPs to mitigate obesity through a systematic review and meta-analysis of animal model-based studies. A comprehensive summary of the included articles was conducted, focusing on the following obesity-related parameters: food intake, body weight gain, epididymal fat size, adipocyte size, liver weight, serum alanine transaminase (ALT) and aspartate transaminase (AST), insulin and tumour necrosis factor-α (TNF-α), and the lipid profile (total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c)). The systematic review demonstrated that seaweed-derived SPs exhibit ameliorative effects against obesity, as evidenced by reductions in food intake, body weight gain, epididymal fat and adipocyte size, liver weight, ALT and AST levels, serum insulin and TNF-α, LDL-c, total cholesterol, and triglycerides and an increase in HDL-c in obese rats administered with seaweed-derived SPs. However, the meta-analysis revealed statistically significant anti-obesity effects of seaweed-derived SPs for most, but not all the parameters tested. Further research in human subjects is necessary not only to ascertain the results of preclinical studies but also to provide conclusive evidence of the anti-obesity potential of SPs in humans.
Functional Rehabilitation in Non-Reconstructed Hemimandibulectomy Patients
Authors: Brauner Edoardo , Laudoni Federico , Rampelli Emilia , Bellizzi Andrea , De Angelis Francesca , Pranno Nicola , Battisti Andrea , Valentini Valentino , Di Carlo Stefano
Published: November 2024

Background and Objectives: Functional rehabilitation in patients with hemimandibulectomy remains a challenge no matter what method of reconstruction is chosen by physicians. In this paper, we aim to evaluate the feasibility of an acceptable occlusal restoration in patients who have undergone hemimanidublectomy without the reestablishment of mandibular continuity. Materials and Methods: Data were collected retrospectively on 10 patients with varying degrees of mandible resection. The greatest challenge in the restoration of an acceptable occlusion form is the natural latero-deviation that occurs in patients whose mandibular continuity was not restored. This causes an unbalanced and uncoordinated occlusal plane. Based on our research, this deviation is highly dependent on three main factors: the presence of teeth (which allow for a proprioceptive stimulus that counteracts the deviation), the extension of the defect and the presence or lack of the coronoid process. Results: Based on the presence of dental elements or lack thereof, patients were either rehabilitated with implant-supported dentures or removable partial dentures. Although the gold standard of care for these patients remains the restoration of mandible continuity through use of bone grafts, an acceptable rehabilitation of occlusion and therefore function may be acquired in non-grafted patients. Conclusions: Both physicians and patients must manage their expectations carefully and be eager to find a compromise to provide the best possible solution given the challenges of the premises.
Promoting Family Involvement in the Management of Delirium in Intensive Care: Scoping Review
Authors: Lange Sandra , Mędrzycka-Dąbrowska Wioletta
Published: November 2024

Background: In recent years, family involvement in ICU patient care has become increasingly significant. Family involvement in delirium management, while desirable, can be difficult for loved ones. Therefore, every attempt should be made and interventions developed to promote and support the family in this process. The aim of this review was to analyze the available literature on interventions and strategies used by ICU staff to support and promote family involvement in the management of delirium in critically ill patients. Methods: The databases searched included the following: MEDLINE, CINAHL, and the Cochrane Library. Studies were included in the review if they were conducted in adult intensive care units and/or addressed interventions to support and promote family/relatives’ involvement in delirium management. Findings: A total of 368 database articles were reviewed. After removing duplicates and checking for inclusion and exclusion criteria, four articles were finally included in the analysis. Research gaps and content analysis identified promotional and supportive interventions for family involvement in delirium management: (I) Education; (II) Mentoring; (III) Partnership. Conclusions: Research gaps to be filled are as follows: (I) the scope of interventions that support and promote family involvement in delirium management; (II) interventions that enhance feelings of efficacy among family members and reduce symptoms of anxiety and depression; and (iii) the impact of specific interventions on patients’ delirium outcomes.
Exploring Cognitive and Behavioral Changes Related to Smoking Among Medical Students in Saudi Arabia: A Cross-Sectional Study
Authors: Aljunaid Mohammed A. , Mehdar Safa Abdullah , Bukhari Haneen Saud , AlSharif Rafal Hussain , AlSharif Rawaf Hussain , AlHarbi Shahad
Published: November 2024

Background and Objectives: This study aims to determine smoking patterns, prevalence, and associated factors among medical students in Jeddah, focusing on experimentation, daily smoking, cessation efforts, awareness of health risks, and attitudes toward quitting. Materials and Methods: A cross-sectional study was conducted in Jeddah, Saudi Arabia, from September to November 2023. It involved 213 medical students, from the second to sixth year, enrolled in various universities. Data collection utilized a comprehensive questionnaire adapted from the World Health Organization’s questionnaire and enhanced with additional relevant items by the researchers. The questionnaire, comprising eight sections, was administered online over a three-month period. Results: About 30.8% reported ever smoking, with 21.6% currently smoking. Among ever-smokers, 43.1% began smoking during college, mostly in the second year. Stress, exploration, and peer influence were frequent reasons for initiating smoking during college years. About 32.3% never considered quitting, while 67.7% thought about it. Regarding quit attempts, 53.8% attempted seriously, and 5.3% quit in the last year. Protective factors against smoking included health concerns and setting a good example. Most participants recognized smoking-related health hazards, with strong consensus on the effectiveness of anti-smoking measures. Notably, many participants expressed proactive attitudes toward smoking cessation interventions. Conclusions: Smoking is prevalent among Saudi medical students, often starting in college due to stress, new experiences, and peer influence. Many consider quitting, probably supported by the educational environment and a sense of responsibility toward personal and public health. Strengthened educational frameworks, including stress management training, are crucial for fostering a health-focused professional identity.
Prevalence of ApoE Alleles in a Spanish Population of Patients with a Clinical Diagnosis of Alzheimer’s Disease: An Observational Case-Control Study
Authors: Bello-Corral Laura , Seco-Calvo Jesús , Molina Fresno Angela , González Ana Isabel , Llorente Ana , Fernández-Lázaro Diego , Sánchez-Valdeón Leticia
Published: November 2024

Background and Objectives: Alzheimer’s dementia is a progressive neurodegenerative disease that affects memory abilities due to genetic and environmental factors. A well-known gene that influences the risk of Alzheimer’s disease is the apolipoprotein E (APOE) gene. The APOE gene is involved in the production of a protein that helps transport cholesterol and other types of fat in the bloodstream. Problems in this process are thought to contribute to the development of Alzheimer’s disease. APOE comes in several forms, which are called alleles (ε2, ε3, ε4). Materials and Methods: Therefore, our study aims to identify those subjects with a higher genetic risk through the polymorphism of the APOE gene, using a population screening in patients with a clinical diagnosis of AD in a region of Spain, Castilla y León, as potential biomarkers and to identify individuals at increased genetic risk by polymorphism of the APOE gene. An observational case-control study was conducted in Castilla y León (Spain). Saliva samples were collected and the ApoE gene was analyzed by PCR and agarose gel electrophoresis, respecting ethical criteria. Results: In the Alzheimer’s population in Castilla y León, a high prevalence of ApoE3 (74%) was found, followed by ApoE4 (22%); in addition, a higher presence of the ε4 allele was found in the Alzheimer’s disease (AD) group than in the control group. It was also observed that the ε2/ε2 genotype was not found in any individual with AD but was found in healthy subjects and that the opposite was observed for the ε4/ε4 genotype. The odds ratio (OR) indicated a risk four times greater of having AD if having the ε4 allele. Conclusions: The demonstrated relation between the different isoforms and the likelihood of developing AD has led to its consideration as a biomarker and a potential pre-symptomatic therapy. The molecular mechanisms that confer a disruptive and protective role to ApoE4 and ApoE2, respectively, are still being studied.
Separation of Antibiotics Using Two Commercial Nanofiltration Membranes—Experimental Study and Modelling
Authors: Anike Obinna , Cuhorka Jiří , Ezeogu Nkechi , Mikulášek Petr
Published: November 2024

The widespread use of antimicrobial drugs has contributed to the increasing trace levels of contaminants in the environment, posing an environmental problem and a challenge to modern-day medicine seeking advanced solutions. Nanofiltration is one such breakthrough solution for the selective removal of antibiotics from wastewater due to their high efficiency, scalability, and versatility. This study examines the separation of antibiotics (sulfamethoxazole (SMX), trimethoprim (TMP), and metformin (MET), respectively) using commercially available membranes with an emphasis on AFC membranes (AFC 30 and AFC 80). Thus, we evaluate their efficacy, performance, and applicability in wastewater treatment processes. The data for characterizing the structural parameters of the NF membranes were determined from an uncharged organic solute rejection experiment, and the effect of various operating conditions on the retention of solutes was evaluated. All experimental data were collected using a laboratory-scale nanofiltration unit and HPLC, and rejection percentages were determined using analytical measurements. The results obtained allowed for the determination of the radius of the membrane pores using the Steric Hindrance Pore (SHP) model, resulting in values of 0.353 and 0.268 nm for the AFC 30 and AFC 80 membranes, respectively. Additionally, higher transmembrane pressure and feed flow were observed to lead to an increased rejection of antibiotics. AFC 30 demonstrated a rejection of 94% for SMX, 87% for TMP, and 87% for MET, while AFC 80 exhibited a rejection of 99.5% for SMX, 97.5% for TMP, and 98% for MET. The sieving effect appears to be the primary separation mechanism for AFC 30, as lower feed-flow rates were observed to intensify concentration polarization, thereby compromising rejection efficiency. On the contrary, AFC 80 experienced less concentration polarization due to its smaller pore sizes, effectively preventing pore clogging. Membrane performance was evaluated using the Spiegler–Kedem–Katchalsky model, based on irreversible thermodynamics, which effectively explained the mechanism of solute transport of antibiotics through the AFC 30 and AFC 80 membranes in the NF process.
The Role of Protein–Lipid Interactions in Priming the Bacterial Translocon
Authors: Sinclair Matt , Tajkhorshid Emad
Published: November 2024

Protein–lipid interactions demonstrate important regulatory roles in the function of membrane proteins. Nevertheless, due to the semi-liquid nature and heterogeneity of biological membranes, and dissecting the details of such interactions at high resolutions continues to pose a major challenge to experimental biophysical techniques. Computational techniques such as molecular dynamics (MD) offer an alternative approach with both temporally and spatially high resolutions. Here, we present an extensive series of MD simulations focused on the inner membrane protein YidC (PDB: 6AL2) from Escherichia coli, a key insertase responsible for the integration and folding of membrane proteins. Notably, we observed rare lipid fenestration events, where lipids fully penetrate the vestibule of YidC, providing new insights into the lipid-mediated regulation of protein insertion mechanisms. Our findings highlight the direct involvement of lipids in modulating the greasy slide of YidC and suggest that lipids enhance the local flexibility of the C1 domain, which is crucial for recruiting substrate peptides. These results contribute to a deeper understanding of how protein–lipid interactions facilitate the functional dynamics of membrane protein insertases, with implications for broader studies of membrane protein biology.
Evaluating Nanofiltration and Reverse Osmosis Membranes for Pharmaceutically Active Compounds Removal: A Solution Diffusion Model Approach
Authors: Shin Yonghyun , Hwang Tae-Mun , Nam Sook-Hyun , Kim Eunju , Park JeongBeen , Choi Yong-Jun , Kye Homin , Koo Jae-Wuk
Published: November 2024

Trace organic contaminants (TrOCs), including pharmaceutically active compounds (PhACs), present significant challenges for conventional water treatment processes and pose potential risks to environmental and human health. To address these issues, nanofiltration (NF) and reverse osmosis (RO) membrane technologies have gained attention. This study aims to evaluate the performance of NF and RO membranes in removing TrOCs from wastewater and develop a predictive model using the Solution Diffusion Model. Experiments were conducted using a stirred cell setup at various target concentrations, stirring speeds, and operating pressures, with acetaminophen and caffeine selected as representative pharmaceutical compounds. The results demonstrated that most of the pharmaceutical compounds were effectively removed, showing excellent performance. NF membranes exhibited high permeate flux with somewhat lower removal efficiency (average 84.17%), while RO membranes demonstrated high removal efficiency (average 99.21%), highlighting their importance in trace pharmaceutical treatment. The predictive model based on the solution diffusion model correlated well with the experimental data, suggesting its potential utility for large-scale system applications. This study confirms that NF and RO membranes are effective technologies for the removal of TrOCs from wastewater, offering a promising solution to the challenges posed by trace pharmaceutical contaminants.
Effects of Heat Treatment and Deformation on Microstructure and Properties of Cu–Ni–Si Alloy/AA8030 Alloy Composite Wires
Authors: Tian Shuke , Zhao Fan , Liu Xinhua
Published: November 2024

The influence of heat treatment and deformation on the microstructure and properties of a Cu–Ni–Si alloy/AA8030 alloy composite wire was studied. After aging at 450 °C for 60 min, the composite wire exhibited relatively high comprehensive properties, with ultimate tensile strength, elongation, and electrical conductivity values of 253 MPa, 11.1%, and 55.3% IACS, respectively. Microstructural analysis revealed that precipitation and dislocation strengthening played important roles in the aged Cu–Ni–Si alloy cladding, whereas grain boundary and dislocation strengthening contributed to the strength of the AA8030 alloy. Then, the wire underwent five passes of drawing with a total deformation of 75%. Significant work hardening changed the ultimate tensile strength, elongation, and electrical conductivity of the composite wire to 422 MPa, 3.3%, and 53.6% IACS, respectively. CuAl2, CuAl and Cu9Al4 layers were formed at the composite interface during aging. The CuAl2 and Cu9Al4 layers grew toward the Al alloy and Cu alloy, respectively, whereas the CuAl layer grew toward both the Al alloy and the Cu alloy.
Additive Manufacturing of Tungsten Carbide (WC)-Based Cemented Carbides and Niobium Carbide (NbC)-Based Cermets with High Binder Content via Laser Powder Bed Fusion
Authors: Miranda Fabio , dos Santos Marcelo Otavio , Condotta Rodrigo , Pereira Nathalia Marina Gonçalves , Rodrigues Daniel , Janasi Suzilene Real , Ortega Fernando dos Santos , Mergulhão Marcello Vertamatti , Coelho Rodrigo Santiago , de Oliveira René Ramos , Martinez Luis Gallego , Batalha Gilmar Ferreira
Published: November 2024

The additive manufacturing technique performed via laser powder bed fusion has matured as a technology for manufacturing cemented carbide parts. The parts are built by additive consolidation of thin layers of a WC and Co mixture using a laser, depending on the power and scanning speed, making it possible to create small, complex parts with different geometries. NbC-based cermets, as the main phase, can replace WC-based cemented carbides for some applications. Issues related to the high costs and dependence on imports have made WC and Co powders emerge as critical raw materials. Furthermore, avoiding manufacturing workers’ health problems and occupational diseases is a positive advantage of replacing WC with NbC and alternative binder phases. This work used WC and NbC as the main carbides and three binders: 100% Ni, 100% Co, and 50Ni/50Co wt.%. For the flowability and spreadability of the powders of WC- and NbC-based alloy mixtures in the powder bed with high cohesiveness, it was necessary to build a vibrating container with a pneumatic turbine ranging from 460 to 520 Hz. Concurrently, compaction was promoted by a compacting system. The thin deposition layers of the mixtures were applied uniformly and were well distributed in the powder bed to minimize the defects and cracks during the direct sintering of the samples. The parameters of the L-PBF process varied, with laser scanning speeds from 25 to 125 mm.s─1 and laser power from 50 to 125 W. Microstructural aspects and the properties obtained are presented and discussed, seeking to establish the relationships between the L-PBF process variables and compare them with the liquid phase sintering technique.
The Effect of Maternal Diet and Lifestyle on the Risk of Childhood Obesity
Authors: Łuszczki Edyta , Wyszyńska Justyna , Dymek Agnieszka , Drożdż Dorota , González-Ramos Laura , Hartgring Isa , García-Carbonell Nuria , Mazur Artur , Erdine Serap , Parnarauskienė Justė , Alvarez-Pitti Julio
Published: November 2024

Background/Objectives: Childhood obesity is a global health problem that affects at least 41 million children under the age of five. Increased BMI in children is associated with serious long-term health consequences, such as type 2 diabetes, cardiovascular disease, and psychological problems, including depression and low self-esteem. Although the etiology of obesity is complex, research suggests that the diet and lifestyle of pregnant women play a key role in shaping metabolic and epigenetic changes that can increase the risk of obesity in their children. Excessive gestational weight gain, unhealthy dietary patterns (including the Western diet), and pregnancy complications (such as gestational diabetes) are some of the modifiable factors that contribute to childhood obesity. The purpose of this narrative review is to summarize the most important and recent information on the impact of the diet and lifestyle of pregnant women on the risk of childhood obesity. Methods: This article is a narrative review that aims to summarize the available literature on the impact of pregnant women’s diet and lifestyle on the risk of obesity in their offspring, with a focus on metabolic and epigenetic mechanisms. Results/Conclusions: Current evidence suggests that a pregnant woman’s lifestyle and diet can significantly contribute to lowering the risk of obesity in their offspring. However, further high-quality research is needed to understand better the metabolic and epigenetic relationships concerning maternal factors that predispose offspring to obesity.
Longitudinal Metabolomics Reveals Metabolic Dysregulation Dynamics in Patients with Severe COVID-19
Authors: Uchimido Ryo , Kami Kenjiro , Yamamoto Hiroyuki , Yokoe Ryo , Tsuchiya Issei , Nukui Yoko , Goto Yuki , Hanafusa Mariko , Fujiwara Takeo , Wakabayashi Kenji
Published: November 2024

Background/Objective: A dysregulated metabolism has been studied as a key aspect of the COVID-19 pathophysiology, but its longitudinal progression in severe cases remains unclear. In this study, we aimed to investigate metabolic dysregulation over time in patients with severe COVID-19 requiring mechanical ventilation (MV). Methods: In this single-center, prospective, observational study, we obtained 236 serum samples from 118 adult patients on MV in an ICU. The metabolite measurements were performed using capillary electrophoresis Fourier transform mass spectrometry, and we categorized the sampling time points into three time zones to align them with the disease progression: time zone 1 (T1) (the hyperacute phase, days 1–3 post-MV initiation), T2 (the acute phase, days 4–14), and T3 (the chronic phase, days 15–30). Using volcano plots and enrichment pathway analyses, we identified the differential metabolites (DMs) and enriched pathways (EPs) between the survivors and non-survivors for each time zone. The DMs and EPs were further grouped into early-stage, late-stage, and consistent groups based on the time zones in which they were detected. Results: With the 566 annotated metabolites, we identified 38 DMs and 17 EPs as the early-stage group, which indicated enhanced energy production in glucose, amino acid, and fatty acid metabolisms in non-survivors. As the late-stage group, 84 DMs and 10 EPs showed upregulated sphingolipid, taurine, and tryptophan–kynurenine metabolisms with downregulated steroid hormone synthesis in non-survivors. Three DMs and 23 EPs in the consistent group showed more pronounced dysregulation in the dopamine and arachidonic acid metabolisms across all three time zones in non-survivors. Conclusions: This study elucidated the temporal differences in metabolic dysregulation between survivors and non-survivors of severe COVID-19, offering insights into its longitudinal progression and disease mechanisms.
Correlation of Red Blood Cell Morphology with Serum Cobalamin and Folate Concentration in Dogs with Chronic Diarrhea: A Retrospective Study
Authors: Ginoudis Argyrios , Ioannidou Anna Maria , Pardali Dimitra , Tsikna Asteria , Polizopoulou Zoe
Published: November 2024

Background/Objectives: Chronic diarrhea in dogs is a prevalent condition that significantly impacts canine health, often leading to weight loss, dehydration, and malnutrition. Diagnosing and treating chronic diarrhea is challenging due to its multifactorial nature, necessitating collaboration among veterinarians across various specialties. Measuring cobalamin and folate levels is a crucial diagnostic step for all dogs with chronic diarrhea. The role of these vitamins in erythropoiesis is well-documented in human medicine, where deficiencies are linked to erythropoietic disorders and megaloblastic anemia. This study explores the relationship between cobalamin and folate concentrations with hematologic parameters in dogs with chronic diarrhea to develop novel diagnostic methods that facilitate timely decision making. Methods: Forty-seven adult dogs with a history of chronic diarrhea (2019–2023) were included in the study. Upon presentation, complete blood count and measurement of cobalamin and folate concentrations were performed. The correlation of cobalamin and folate levels with erythrocytic parameters, including hematocrit (HCT), hemoglobin concentration (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red cell distribution width (RDW), and reticulocyte count, as well as morphological changes in the blood smear were examined. Results: Serum cobalamin was significantly correlated with RBC (p = 0.032), HGB (p = 0.006), HCT (p = 0.005), and MCV (p = 0.022). Anisocytosis was significantly correlated with hypocobalaminemia (p = 0.002), while acanthocytosis correlated with normal cobalamin levels (p = 0.046). No correlation was found between serum folate and erythrocytic parameters or morphological changes. Conclusions: These findings emphasize cobalamin’s potential role in canine erythropoiesis, highlighting the need for routine evaluation and supplementation when necessary. Conversely, the lack of association with folate suggests it plays a less significant role in this species. These results underscore the importance of complete blood count in the diagnostic investigation of dogs with chronic diarrhea.
Global Lipidomics Reveals the Lipid Composition Heterogeneity of Extracellular Vesicles from Drug-Resistant Leishmania
Authors: Kim Sehyeon (Erica) , Ibarra-Meneses Ana Victoria , Fernandez-Prada Christopher , Huan Tao
Published: November 2024

Background: The rise of drug-resistant Leishmania strains presents a significant challenge in the treatment of Leishmaniasis, a neglected tropical disease. Extracellular vesicles (EVs) produced by these parasites have gained attention for their role in drug resistance and host–pathogen interactions. Methods: This study developed and applied a novel lipidomics workflow to explore the lipid profiles of EVs from three types of drug-resistant Leishmania infatum strains compared to a wild-type strain. EVs were isolated through ultracentrifugation, and their lipid content was extracted using a modified Matyash protocol. LC-MS analysis was performed, and data processing in MS-DIAL enabled lipid identification and quantification. Statistical analysis in MetaboAnalyst revealed strain-specific lipid alterations, highlighting potential links between lipid composition and drug resistance mechanisms. Results: Our results show distinct alterations in lipid composition associated with drug resistance. Specifically, drug-resistant strains exhibited reduced levels of phosphatidylcholine (PC) and phosphatidylglycerol (PG), particularly in the amphotericin B-resistant strain LiAmB1000.1. Sterol and glycerolipid species, including cholesteryl ester (CE) and triacylglycerol (TG) were also found to be diminished in LiAmB1000.1. These changes suggest significant lipid remodeling under drug pressure, potentially altering the biophysical properties of EV membranes and their capacity for molecule transfer. Furthermore, the lipidomic profiles of EVs from the other resistant strains, LiSb2000.1 and LiMF200.5, also displayed unique alterations, underscoring strain-specific adaptations to different drug resistance mechanisms. Conclusions: These significant alterations in lipid composition suggest potential lipid-based mechanisms underlying drug resistance in Leishmania, providing new avenues for therapeutic intervention.
Structural and Functional Integration of Tissue-Nonspecific Alkaline Phosphatase Within the Alkaline Phosphatase Superfamily: Evolutionary Insights and Functional Implications
Authors: Imam Iliass , Rautureau Gilles , Violot Sébastien , Drevet Mulard Eva , Magne David , Ballut Lionel
Published: November 2024

Phosphatases are enzymes that catalyze the hydrolysis of phosphate esters. They play critical roles in diverse biological processes such as extracellular nucleotide homeostasis, transport of molecules across membranes, intracellular signaling pathways, or vertebrate mineralization. Among them, tissue-nonspecific alkaline phosphatase (TNAP) is today increasingly studied, due to its ubiquitous expression and its ability to dephosphorylate a very broad range of substrates and participate in several different biological functions. For instance, TNAP hydrolyzes inorganic pyrophosphate (PPi) to allow skeletal and dental mineralization. Additionally, TNAP hydrolyzes pyridoxal phosphate to allow cellular pyridoxal uptake, and stimulate vitamin B6-dependent reactions. Furthermore, TNAP has been identified as a key enzyme in non-shivering adaptive thermogenesis, by dephosphorylating phosphocreatine in the mitochondrial creatine futile cycle. This latter recent discovery and others suggest that the list of substrates and functions of TNAP may be much longer than previously thought. In the present review, we sought to examine TNAP within the alkaline phosphatase (AP) superfamily, comparing its sequence, structure, and evolutionary trajectory. The AP superfamily, characterized by a conserved central folding motif of a mixed beta-sheet flanked by alpha-helices, includes six subfamilies: AP, arylsulfatases (ARS), ectonucleotide pyrophosphatases/phosphodiesterases (ENPP), phosphoglycerate mutases (PGM), phosphonoacetate hydrolases, and phosphopentomutases. Interestingly, TNAP and several ENPP family members appear to participate in the same metabolic pathways and functions. For instance, extra-skeletal mineralization in vertebrates is inhibited by ENPP1-mediated ATP hydrolysis into the mineralization inhibitor PPi, which is hydrolyzed by TNAP expressed in the skeleton. Better understanding how TNAP and other AP family members differ structurally will be very useful to clarify their complementary functions. Structurally, TNAP shares the conserved catalytic core with other AP superfamily members but has unique features affecting substrate specificity and activity. The review also aims to highlight the importance of oligomerization in enzyme stability and function, and the role of conserved metal ion coordination, particularly magnesium, in APs. By exploring the structural and functional diversity within the AP superfamily, and discussing to which extent its members exert redundant, complementary, or specific functions, this review illuminates the evolutionary pressures shaping these enzymes and their broad physiological roles, offering insights into TNAP’s multifunctionality and its implications for health and disease.
Electrochemical Mill Grinding of (TiB+TiC)/Ti6Al4V Composites Using Abrasive Tool with Bottom Outlet Holes
Authors: Niu Shen , Huang Kaiqiang , Ming Pingmei , Qin Ge , Peng Yansen
Published: November 2024

Difficult-to-cut titanium matrix composites (TMCs) are widely used in the aerospace, automotive, and defense sectors due to their excellent physical properties. Electrochemical mill grinding (ECMG) can achieve the processing effects of electrochemical milling and electrochemical grinding using the same tool, which has the potential to complete the rough and finish machining of TMCs in succession. However, in the rough machining stage, the bottom of the slot becomes concave due to the inevitable stray corrosion, leading to poor flatness, which increases the machining allowance for subsequent finish machining. In this paper, a bottom outlet hole layout of an abrasive tool with a diameter of 6 mm is proposed. Dynamic simulations demonstrate that the electrolyte flow rate in both side regions of the slot is significantly increased by the bottom outlet holes. The experimental results confirm that, compared with the tool without bottom outlet holes, a 61.2% reduction in the bottom flatness can be achieved when using the newly proposed tool during rough machining. After the finish machining, a slot with a width of 8 mm and a depth of 4.8 mm was obtained on the TMCs, which had a flat bottom and sidewall surface with good surface quality.
The Superior Response and High Reproducibility of the Memristor-Integrated Low-Power Transparent SnO₂ Gas Sensor
Authors: Kim Taegi , Kim Hee-Dong
Published: November 2024

We present a SnO2 gas sensor with an HfO2 layer that exhibits enhanced performance and reliability for gasistor applications, combining a gas sensor and a memristor. The transparent SnO2 gasistor with a 30 nm HfO2 layer demonstrated low forming voltages (7.1 V) and a high response rate of 81.28% to 50 ppm of NO2 gas, representing an approximately 174.86% increase compared to the response of 29.58% from the SnO2 gas sensor without the HfO2 layer. The device also showed improved power efficiency and exceptional long-term stability, with reproducibility tests over 10 days at 10 ppm NO2 showing a minimal variation of 2.4%. These results indicate that the proposed transparent memristor with the 30 nm HfO2 layer significantly enhances the device’s reliability and effectiveness for gasistor applications.
Genomic Insights into Stutzerimonas kunmingensis TFRC-KFRI-1 Isolated from Manila Clam (Ruditapes philippinarum): Functional and Phylogenetic Analysis
Authors: Lee Myunglip , Yi Sunghun , Choi Jiho , Pak Yukyoung , Lim Chaehyeon , Kim Yucheol
Published: November 2024

Stutzerimonas kunmingensis TFRC-KFRI-1, isolated from the gut of Manila Clam in the sediment of the West Sea of Korea, was investigated for its potential as a probiotic bacterium. This strain, belonging to the family Pseudomonadaceae, was previously classified as Pseudomonas kunmingensis but later reclassified to the genus Stutzerimonas, known for species with bioremediation and probiotic properties. To evaluate its genomic features and potential applications, we performed draft-genome sequencing and analysis. The genome of S. kunmingensis TFRC-KFRI-1 was assembled into a 4,756,396 bp sequence with a 62.8% GC content. Genomic analysis suggested potential genes for carbohydrate degradation and lactic acid production. The strain exhibited high average nucleotide identity (ANI) and 16S rRNA similarity with S. kunmingensis HL22-2T, further supporting its potential as a probiotic. This genome sequence provides valuable insights into the functional capabilities of S. kunmingensis TFRC-KFRI-1 and its potential applications in various industries, including aquaculture and food biotechnology. The genome sequence is available under GenBank accession number JBGJJB000000000.1, with related project information under BioProject PRJNA1147901 and Bio-Sample SAMN43173893.