bluuebunny/crossref_metadata_2025 huggingface dataset:
Metacognitive Differences in Amnestic Mild Cognitive Impairment and Healthy Cognition: A Cross-Sectional Study Employing Online Measures
Authors: Bampa Grigoria , Tsolaki Magdalini , Moraitou Despina , Metallidou Panagiota , Masoura Elvira , Mintziviri Maria , Paparis Konstantinos , Tsourou Dorothea , Papantoniou Georgia , Sofologi Maria , Papaliagkas Vasileios , Kougioumtzis Georgios , Papatzikis Efthymios
Published: September 2023

This study aimed to examine metacognitive abilities in individuals diagnosed with amnestic mild cognitive impairment (aMCI) by using online metacognitive measures during cognitive tasks. A total of 100 participants were enrolled, all aged 50 or older (mean age = 61.98; SD = 6.27), and with a minimum of six years of education (mean = 14.95; SD = 2.94). The sample included 50 individuals with aMCI (34 females) and 50 healthy controls (HC) (33 females). Both groups underwent metacognitive versions of memory tasks (Doors and People) and executive functions tasks (Wisconsin Card Sorting Test). Metacognition was assessed through confidence ratings given after each answer (referred to as metacognitive monitoring) and the accuracy of the participants’ decisions to include or exclude answers from their final scores (known as metacognitive control). The results showed that although individuals with aMCI were aware of their cognitive limitations—evidenced by their lower confidence ratings across all tasks—they still exhibited overconfidence relative to their actual performance. Moreover, they included a greater number of incorrect answers in their final scores compared to the healthy control group. These findings suggest that while individuals with aMCI retain some level of awareness, their self-evaluations appear to lack precision. This observation was consistent across both types of cognitive tasks. The results underscore the need for additional research to better understand metacognition in MCI as well as the interplay between metacognitive monitoring and control.
Effects of Different Livestock Grazing on Foliar Fungal Diseases in an Alpine Grassland on the Qinghai–Tibet Plateau
Authors: Tian Zhen , Li Wenjie , Kou Yixin , Dong Xin , Liu Huining , Yang Xiaoxia , Dong Quanmin , Chen Tao
Published: September 2023

In grassland ecosystems, the occurrence and transmission of foliar fungal diseases are largely dependent on grazing by large herbivores. However, whether herbivores that have different body sizes differentially impact foliar fungal diseases remains largely unexplored. Thus, we conducted an 8-year grazing experiment in an alpine grassland on the Qinghai–Tibet Plateau in China and tested how different types of livestock (sheep (Ovis aries), yak (Bos grunniens), or both)) affected foliar fungal diseases at the levels of both plant population and community. At the population level, grazing by a single species (yak or sheep) or mixed species (sheep and yak) significantly decreased the severity of eight leaf spot diseases. Similarly, at the community level, both single species (yak or sheep) and mixed grazing by both sheep and yak significantly decreased the community pathogen load. However, we did not find a significant difference in the community pathogen load among different types of livestock. These results suggest that grazing by large herbivores, independently of livestock type, consistently decreased the prevalence of foliar fungal diseases at both the plant population and community levels. We suggest that moderate grazing by sheep or yak is effective to control the occurrence of foliar fungal diseases in alpine grasslands. This study advances our knowledge of the interface between disease ecology, large herbivores, and grassland science.
Unveiling Cryptic Species Diversity and Genetic Variation of Lasiodiplodia (Botryosphaeriaceae, Botryosphaeriales) Infecting Fruit Crops in Taiwan
Authors: Ko Ya-Zhu , Liyanage Wasantha Kumara , Shih Huei-Chuan , Tseng Min-Nan , Shiao Meng-Shin , Chiang Yu-Chung
Published: September 2023

The genus Lasiodiplodia, a member of the family Botryosphaeriaceae, is an important fungal disease genus in agriculture. However, the Lasiodiplodia species survey and genetic diversity in Taiwan remain unclear. This study aimed to investigate the Lasiodiplodia species associated with various fruit species to explore the cryptic Lasiodiplodia species diversity, validate species delimitation, and unveil cryptic genetic diversity. Overall, six Lasiodiplodia species were identified, with several new records of infection identified. Additionally, phylogenetic analyses indicated that the relations of all isolates of L. theobromae might be paraphyletic. They were grouped with L. brasiliense based on Automatic Barcode Gap Discovery (ABGD), Automatic Partitioning (ASAP) and structure-based clustering analyses. These analyses did not provide conclusive evidence for L. brasiliensis as a stable species. It may be necessary to gather more information to clarify the species delineation. The multiple new records of Lasiodiplodia species with high genetic diversity and differentiation revealed that the diversity of Lasiodiplodia in Taiwan was underestimated in the past. We found that L. theobromae has the highest number of haplotypes but the lowest number of haplotype and nucleotide diversities, indicating a recent population expansion. This was supported by the significant negative Tajima’s D and Fu and Li’s D* tests. The high genetic diversity, low gene flow, and host-associated differentiation of Lasiodiplodia species indicate that they might harbour powerful evolutionary potential in Taiwan. This study provided critical insights into genetic variation, host-associated differentiation, and demography of Lasiodiplodia species, which would be helpful for disease management of related pathogens.
Triglycerides, Obesity and Education Status Are Associated with the Risk of Developing Type 2 Diabetes in Young Adults, Cohort Study
Authors: Garbuzova Evgeniia V. , Shcherbakova Lilia V. , Rymar Oksana D. , Khudiakova Alyona D. , Shramko Victoria S. , Ragino Yulia I.
Published: September 2023

Background: It is important to determine the influence of traditional risk factors on the development of type 2 diabetes mellitus (T2DM) in young adults. Goal of the research: To study the incidence of T2DM and factors that increase the risk of its occurrence during the observation of a cohort of young adults. Materials and methods: 1341 people aged 25–44 were included in the study from 2013 to 2017, of whom 622 were men (46.4%). The examination included anamnesis, anthropometric data, and a blood test. Cases of developed T2DM were identified by comparing the Diabetes Mellitus Register, medical records of patients, and the database of examined individuals from 2019 to 2023. T2DM Results: In the examined population, 11 participants (0.82%) developed T2DM. The prevalence of T2DM was 0.96% in men and 0.69% in women. Patients with T2DM had a higher waist circumference, BMI, SBP, TG, and lower HDL than patients without T2DM, and were also less likely to have a higher education. The risk of developing T2DM increases 6.5 times at a BMI of ≥30 kg/m2, and 5.2 times at a TG level of ≥1.7 mmol/L, regardless of other risk factors. In the absence of a higher education, the risk of developing T2DM is increased by 5.6 times. Conclusion: In young people, high triglyceride levels, obesity, and a low level of education are associated with the risk of developing type 2 diabetes, regardless of other factors.
The Association between Hip Joint Morphology and Posterior Wall Fracture: Analysis of Radiologic Parameters in Computed Tomography
Authors: Kim Han Soul , Mun Ki Uk , Kim Chul-Ho
Published: September 2023

Although numerous radiologic parameters of abnormal hip joint morphology are utilized in practice, studies on the relation of these parameters to acetabular fractures are limited. This study hypothesized that certain morphological features of hip joints are associated with acetabular posterior wall (PW) fracture patterns and aimed to identify morphological characteristics predictive of acetabular PW fracture. The records of 107 consecutive patients, who were diagnosed with acetabular fractures in a level I trauma center from August 2017 to April 2021, were initially reviewed. After excluding patients who lacked proper radiographic evaluation and had previous surgery or concomitant injury on the ipsilateral lower limb, a total of 99 patients were analyzed to investigate the morphological characteristics of the hip joint, measured in computed tomography, associated with acetabular posterior wall fracture. We included patient demographics, acetabular index (AI), sharp angle, acetabular depth-to-width ratio (AD/WR), center-edge angle (CEA), head–neck offset ratio (HNOR), acetabular head index (AHI), anterior acetabular sector angle (AASA), posterior acetabular sector angle (PASA), and acetabular version angle (AVA) in the univariate and multivariate analyses. The injury mechanism (p = 0.001) and AD/WR (p = 0.021) were predictors of PW fracture in the univariate analysis. In the multivariable analysis, injury mechanism (p = 0.011), AI (coefficient B = 0.320; Exp (B) = 1.377; p = 0.017), and AD/WR (coefficient B = 33.047; Exp (B) = 2.250 × 1014; p = 0.028) were significant predictors of PW fracture. This study highlights the importance of morphological factors, such as a larger AI and AD/WR, that may influence joint stress distribution, resulting in acetabular PW fracture. Understanding these pathomechanisms may protect the hip joint and prevent future injuries through the early identification and treatment of pathological conditions.
Identifying the Spatial Patterns and Influencing Factors of Leisure and Tourism in Xi’an Based on Point of Interest (POI) Data
Authors: Qu Xiaoshuang , Xu Gaoyang , Qi Jinghui , Bao Hongjie
Published: September 2023

Leisure and tourism spaces are shared by both residents and tourists seeking a higher quality of life. Most of the literature focuses only on the study of a particular type of leisure or tourism space in cities and lacks an overall exploration of the distribution patterns of urban leisure and tourism formats. Based on the leisure and tourism point of interest (POI) data of 11 districts in Xi’an, this paper uses geospatial analysis to examine the spatial patterns of leisure and tourism facilities and their influencing factors in Xi’an. It is found in this study that the distributions overall and the various types of leisure and tourism spaces in Xi’an show the characteristics of central urban agglomeration and sparse dispersion in the surrounding urban areas. Different types of leisure and tourism patterns have obvious spatial scale dependence, but there are differences in the scope of spatial selection. In general, the core agglomeration area has limited radiation and driving effects on the peripheral areas, and there is a prominent phenomenon of imbalance in the distribution of leisure and tourism facilities following a single industrial structure. The formation of the spatial patterns of leisure and tourism is the result of a combination of dominant factors, driving factors, safeguarding factors, and other triggering factors. Urban leisure and tourism spaces are intertwined, and the spatial balance and industrial diversification of leisure and tourism can be promoted through scientific spatial planning. This study aims to provide services for urban land planning and policy-making by revealing the spatial distribution principles of leisure and tourism sites in tourist cities as represented by Xi’an.
Examining the Overall and Heterogeneous Impacts of Urban Spatial Structure on Carbon Emissions: A Case Study of Guangdong Province, China
Authors: Luo Ke , Chen Shuo , Cui Shixi , Liao Yuantao , He Yu , Zhou Chunshan , Wang Shaojian
Published: September 2023

The variation in the urban spatial structure (USS) has profound impacts on carbon emissions. Studying the relationship between the two can provide guidance for carbon neutrality strategies and the construction of low-carbon cities in China. However, there is currently a lack of comparative research on the different regions within a province. In this paper, the spatiotemporal evolution of the USS and carbon emissions, at five-year intervals from 2000 to 2020, is investigated in 21 prefecture-level cities in Guangdong Province, China, and the overall relationship of the USS to carbon emissions and their spatiotemporal variations are analyzed by using a two-way fixed-effects model and a geographically and temporally weighted regression model, respectively. The results show that, first, over the past twenty years, the scale of cities has continued to expand, with increasing continuity and aggregation in the built-up areas, while the complexity and fragmentation of their shapes have gradually decreased. Second, the gap in carbon emissions between the Pearl River Delta and other regions in Guangdong shows a trend of first decreasing and then increasing, with high values concentrated in the Pearl River Delta region and the city of Shantou in the east. Third, compared to socio-economic factors, the USS has a more direct and pronounced impact on carbon emissions. Urban expansion and the increased complexity of land patches promote carbon emissions, whereas improving urban spatial continuity and compactness can reduce carbon emissions. Fourth, the dominant spatial structure indicators of carbon emissions differ among the regions of eastern, western, and northern Guangdong and the Pearl River Delta. This study proposes spatial optimization strategies for the low-carbon development of cities in Guangdong Province, providing a new perspective for integrating urban layout and emission reduction policies.
The Nature and Production of Urban Space in Latin America: A Historical Review of the Case of Ibagué (Colombia)
Authors: González-Calle Jorge Luis , Sánchez Contreras César Augusto , Monteserín Abella Obdulia
Published: September 2023

The production of urban space in Latin America turns out to be a social product resulting from a historical process in which natural space undergoes significant transformations. This paper analyses how the urban history of Ibagué (Colombia) is related to three historical processes crossed by nature, identifying common aspects with other Latin American cities: nature as a limit to urban growth (conquest and colony), nature as an artifice of urban space (modern city), and nature as a transition zone between the city and the countryside (metropolitan edge). Methodologically, the article is approached from the historical perspective proposed by Fernand Braudel as the longue durée. To this end, an analysis of primary sources was carried out. These sources allowed us to see how urban space was constructed and planned throughout history. The primary sources emphasized written sources: chronicles of the Indies, royal ordinances, municipal decrees, pilot plans for urban growth, and urban development plans. Visual sources were also used: maps, sketches, engravings, and photographs to construct an image of the city and its relationship with nature. The results showed the importance of urban planning by considering the relationship between urban space and nature as two inseparable elements and providing elements for reflecting on contemporary environmental problems.
Investigating the Spatial Heterogeneity and Influencing Factors of Urban Multi-Dimensional Network Using Multi-Source Big Data in Hangzhou Metropolitan Circle, Eastern China
Authors: Zhang Jing , Li Lei , Zhu Congmou , Hao Qi , Chen Xinming , Yu Zhoulu , Gan Muye , Li Wuyan
Published: September 2023

Exploring the spatial heterogeneity of urban multi-dimensional networks and influencing factors are of great significance for the integrated development of metropolitan circle. This study took Hangzhou metropolitan circle as an example, using multi-source geospatial big data to obtain urban population, transportation, goods, capital, and information flow information among sub-cities. Then, spatial visualization analysis, social network analysis, and geographical detector were applied to analyze the differences in spatial structure of multiple urban networks and influencing factors in Hangzhou metropolitan circle, respectively. The results showed that (1) the network connections of population, traffic, goods, and capital flows transcended geographical proximity except that of information flow, and population and traffic flow networks were found to be more flattened in Hangzhou metropolitan circle than in other urban networks; (2) the comprehensive urban network of Hangzhou metropolitan circle was imbalanced across sub-cities, presenting hierarchical and unipolar characteristics; and (3) the influence of traffic distance on the network spatial structure of Hangzhou metropolitan was stronger than the geographical distance, and the interactions between traffic distance and socioeconomic factors would further enhance the regional differentiation of the network spatial structure. This study could provide scientific reference for constructing a coordinated and integrated development pattern in a metropolitan circle.
From Trash to Profit: How Packaging Waste Management Has Driven the Circular Economy—An Integrative Literature Review
Authors: Cerqueira-Streit Jorge Alfredo , Guarnieri Patrícia , de Oliveira Luciel Henrique , Demajorovic Jacques
Published: September 2023

Background: The COVID-19 pandemic has intensified the need to adopt a restorative and regenerative model proposed by circular economy (CE). Methods: This article aims to identify the current status of packaging waste management in the CE context through an integrative literature review using Scopus and Web of Science databases. Using the Bibliometrix package, 162 articles were analyzed. Results: A bibliometric overview is presented, including the prominent authors and journals, and most cited articles, techniques and research methods used. Most of the analyzed articles are of the theoretical–empirical, quali–quantitative type, and plastic is the most studied material when a paper focused on one waste item. The contribution of packaging waste management for the transition to CE is discussed, highlighting important actions such as the replacement of materials to increase recyclability, the installation of voluntary delivery points associated with education programs focusing on the environment and support for cooperatives of waste pickers. In addition, a research agenda was developed that highlights the main gaps identified to guide future studies. Conclusion: Finally, the managerial contributions of the study are emphasized in particular by providing insight into the implementation of this model of growing international interest.
Effect of Oxygen and Moisture on the Friction and Wear of Carbon Fiber-Reinforced Polymers
Authors: Johansson Pontus , Marklund Pär , Björling Marcus , Shi Yijun
Published: September 2023

Carbon fiber-reinforced polytetrafluoroethylene (CF/PTFE) composites are frequently used in tribological dry gas applications, such as in dynamic seals in reciprocating hydrogen gas compressors and Stirling engines, due to their superior friction and wear. Due to the increasing concerns regarding fluoropolymers as possible pollutants of harmful per- and poly-fluoroalkyl substances (PFAS) emissions, replacements for PTFE should be investigated. The literature indicates that CF-reinforced polyetheretherketone (CF/PEEK) may have similar favorable tribological properties to CF/PTFE. However, the tribological behavior of CF/PEEK in dry gas is poorly understood, and no direct comparison has been made between the two materials. The aim of this study was to compare the effect of oxygen and moisture on the friction and wear of CF/PTFE and CF/PEEK. Tribological tests were carried out with a tri-pin-on-disc tribometer in a nitrogen environment with individually controlled contents of oxygen and moisture. The results showed that the effect of oxygen and moisture are distinctly different for CF/PTFE and CF/PEEK. While CF/PTFE performs best in oxygen-deficient environments, CF/PEEK performs best in moisture-enriched environments. Complementary tests with a PTFE composite filled with both CF and PEEK suggested that the environmental sensitivity can be significantly reduced by combining the two polymers.
Influence of Nano-SiO2 Content on Cement Paste and the Interfacial Transition Zone
Authors: Zhang Shaofeng , Liu Ronggui , Lu Chunhua , Hong Junqing , Chen Chunhong , Xu Jiajing
Published: September 2023

Nano-SiO2 (NS) is widely used in cement-based materials due to its excellent physical properties. To study the influence of NS content on a cement paste and the interfacial transition zone (ITZ), cement paste samples containing nano content ranging from 0 to 2% (by weight of cement) were prepared, and digital image correlation (DIC) technology was applied to test the mechanical properties. Finally, the optimal NS content was obtained with statistical analysis. The mini-slump cone test showed that, with the help of superplasticizer and ultrasonic treatment, the flowability decreased continuously, as the NS content increased. The DIC experimental results showed that NS could effectively improve the mechanical properties of the cement paste and the ITZ. Specifically, at the content level of 1%, the elastic modulus of cement paste and ITZ was 20.95 GPa and 3.20 GPa, respectively. When compared to that without nanomaterials, the increased amplitude was 73.50% and 90.50%, respectively. However, with the further increase in NS content, the mechanical properties decreased, which was mainly caused by the agglomeration of nanomaterials. Additionally, the NS content did not exhibit a significant effect on the thickness of the ITZ, and its value was maintained at 76.91–91.38 μm. SEM confirmed that NS would enhance the microstructure of both cement paste and ITZ.
The Approximation Characteristics of Weighted p-Wiener Algebra
Authors: Chen Ying , Pan Xiangyu , Xu Yanyan , Chen Guanggui
Published: September 2023

In this paper, we study the approximation characteristics of weighted p-Wiener algebra AωpTd for 1≤p<∞ defined on the d-dimensional torus Td. In particular, we investigate the asymptotic behavior of the approximation numbers, Kolmogorov numbers, and entropy numbers associated with the embeddings id:AωpTd→ATd and id:AωpTd→LqTd for 1≤p, q<∞, where ATd is the Wiener algebra defined on the d-dimensional torus Td.
Stability of the Exponential Type System of Stochastic Difference Equations
Authors: Shaikhet Leonid
Published: September 2023

The method of studying the stability in the probability for nonlinear systems of stochastic difference equations is demonstrated on two systems with exponential and fractional nonlinearities. The proposed method can be applied to nonlinear systems of higher dimensions and with other types of nonlinearity, both for difference equations and for differential equations with delay.
A Study on Two-Warehouse Inventory Systems with Integrated Multi-Purpose Production Unit and Partitioned Rental Warehouse
Authors: Jagadeesan Viswanath , Rajamanickam Thilagavathi , Schindlerova Vladimira , Subbarayan Sreelakshmi , Cep Robert
Published: September 2023

A study of two warehouse inventory systems with a production unit is developed in this article with some constraints which are of practical applicability to optimize the total production cycle and its cost. A production unit evolves in three different states to retain its quality and prolong its lifetime: the state of producing items, the state of reworking the identified defective items, and the state of being idle. It processes the items up to a certain time point. The screening process starts immediately after a product comes out of the production unit. The classified non-defective items are first stored in own warehouse (OW), after filling to its maximum capacity, and the remaining items fill in the first block RW1 of the rental warehouse RW. All identified defective items are stored in the second block RW2 of RW. The holding cost of an item is higher in RW than OW. All defective items are sent to the production unit for re-do processes as a single lot immediately after the stop of the production and re-do items are stored in RW1 to satisfy the demand. The items in the RW1 are of higher priority in satisfying the demands after the stop of the production unit in producing new items as to deduce the total cost. Demand is assumed as both time and advertisement dependent and is encouraged once production starts. The deterioration rate differs in both warehouses. No backlog is entertained. The study is directed to achieve optimum total cycle cost towards the attainment of the optimum production time slot and the entire cycle of the system. We have arrived at explicit expressions for the total cost function of the entire production cycle. An analytic optimization process of the discriminant method is employed in the form of an algorithm to arrive at the optimum total cost. It provides a numerical illustration of a specific environment. The implications of the current research work are as follows. The optimum utility of production units in three different states in arriving at the optimum total cost is extensively studied with respect to deterioration, demand, and production rates. It also examined the influence of fluctuating deterioration, demand, and production parameters in arriving at optimum deterioration cost, holding cost, and total cycle cost, as they have important managerial insights. The effect of rental charges on the optimum total cost is examined as the system is used for multi-purpose storage.
The Effect of Conjugated Linoleic Acid Supplementation on Densitometric Parameters in Overweight and Obese Women—A Randomised Controlled Trial
Authors: Jamka Małgorzata , Czochralska-Duszyńska Agata , Mądry Edyta , Lisowska Aleksandra , Jończyk-Potoczna Katarzyna , Cielecka-Piontek Judyta , Bogdański Paweł , Walkowiak Jarosław
Published: September 2023

Background and Objectives: Conjugated linoleic acid (CLA) can improve bone health in animals, yet the effects on humans have not been consistent. Therefore, this parallel randomised controlled trial aimed to assess the effect of CLA supplementation on bone mineral density (BMD) and content (BMC) in overweight or obese women. Materials and Methods: The study population included 74 women who were divided into the CLA (n = 37) and control (n = 37) groups. The CLA group received six capsules per day containing approximately 3 g of cis-9, trans-11 and trans-10, cis-12 CLA isomers in a 50:50 ratio. The control group received the same number of placebo capsules that contained sunflower oil. BMC and BMD at total body, lumbar spine (L1–L4), and femoral neck were measured before and after a three-month intervention. Results: The comparison of BMC and BMD for the total body, lumbar spine (L1–L4), and femoral neck before and after the intervention showed no differences between the groups. However, a within-group analysis demonstrated a significant increase in BMC (p = 0.0100) and BMD (p = 0.0397) at lumbar spine (L1–L4) in the CLA group. Nevertheless, there were no significant differences between the CLA and placebo groups in changes in all analysed densitometric parameters. Conclusions: Altogether, three-month CLA supplementation in overweight and obese women did not improve bone health, although the short intervention period could have limited our findings, long-term intervention studies are needed. The study protocol was registered in the German Clinical Trials Register database (ID: DRKS00010462, date of registration: 4 May 2016).
Experimental Investigation of a Plate–Frame Water Gap Membrane Distillation System for Seawater Desalination
Authors: Lawal Dahiru U. , Abdulazeez Ismail , Alsalhy Qusay F. , Usman Jamilu , Abba Sani. I. , Mansir Ibrahim B. , Sathyamurthy Ravishankar , Kaleekkal Noel Jacob , Imteyaz Binash
Published: September 2023

This study presented a detailed investigation into the performance of a plate–frame water gap membrane distillation (WGMD) system for the desalination of untreated real seawater. One approach to improving the performance of WGMD is through the proper selection of cooling plate material, which plays a vital role in enhancing the gap vapor condensation process. Hence, the influence of different cooling plate materials was examined and discussed. Furthermore, two different hydrophobic micro-porous polymeric membranes of similar mean pore sizes were utilized in the study. The influence of key operating parameters, including the feed water temperature and flow rate, was examined against the system vapor flux and gained output ratio (GOR). In addition, the used membranes were characterized by means of different techniques in terms of surface morphology, liquid entry pressure, water contact angle, pore size distribution, and porosity. Findings revealed that, at all conditions, the PTFE membrane exhibits superior vapor flux and energy efficiency (GOR), with 9.36% to 14.36% higher flux at a 0.6 to 1.2 L/min feed flow rate when compared to the PVDF membrane. The copper plate, which has the highest thermal conductivity, attained the highest vapor flux, while the acrylic plate, which has an extra-low thermal conductivity, recorded the lowest vapor flux. The increasing order of GOR values for different cooling plates is acrylic < HDPE < copper < aluminum < brass < stainless steel. Results also indicated that increasing the feed temperature increases the vapor flux almost exponentially to a maximum flux value of 30.36 kg/m2hr. The system GOR also improves in a decreasing pattern to a maximum value of 0.4049. Moreover, a long-term test showed that the PTFE membrane, which exhibits superior hydrophobicity, registered better salt rejection stability. The use of copper as a cooling plate material for better system performance is recommended, while cooling plate materials with very low thermal conductivities, such as a low thermally conducting polymer, are discouraged.
Copolyimide Brushes as a Component of a Hybrid Poly(phenylene Oxide) Membrane for Controlling Gas Separation: Effect of Water, Methanol, and Hexane Vapors
Authors: Tian Nadezhda , Pulyalina Alexandra , Faykov Ilya , Gofman Iosif , Zolotovsky Konstantin , Polotskaya Galina
Published: September 2023

The effect of water, methanol, and hexane vapors on gas permeability was studied in a hybrid membrane containing 5 wt% copolyimide brushes with poly(methyl methacrylate) side chains (PI-g-PMMA) in a poly(phenylene oxide) (PPO) matrix, and in a pristine PPO membrane. These membranes in the form of dense nonporous films were further examined by atomic force microscopy (AFM) and scanning electron microscopy (SEM), as well as by measuring their mechanical and gas transport properties. A gas separation study of the membranes in a dry state and the membranes saturated with water, methanol, and hexane vapors was performed to estimate the effect of each vapor on the H2, CO2, N2 permeability and selectivity in the separation of H2/N2 and CO2/N2 pairs. In general, saturation with water, methanol, and hexane vapors caused a decrease in the gas permeability of both membranes. The hybrid membrane containing copolyimide brushes demonstrated enhanced selectivity in the separation of H2/N2 and CO2/N2 pairs. It was found that a special effect of the vapors used for membrane saturation is associated with their molar volume. The solubility and diffusion coefficients of N2 and CO2 were obtained by Grand Canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations.
Effect of Friction Stir Welding on Short-Term Creep Response of Pure Titanium
Authors: Spigarelli Stefano , Regev Michael , Santoni Alberto , Cabibbo Marcello , Santecchia Eleonora
Published: September 2023

Friction Stir Welding (FSW) is a recent joining technique that has received considerable attention. FSW causes significant variations in the material microstructure commonly associated with changes in the mechanical properties. The present study deals with the creep response of pure titanium (CP-Ti grade 2) after FSW. Dog-bone creep samples, obtained by machining, which show the longitudinal axis of each sample being perpendicular to the welding direction, were tested in constant load machines at 550 and 600 °C. The creep response of the FSW samples was analyzed and compared with that of the unwelded material. The shape of the creep curves was conventional, although the FSW samples went to rupture for strains lower than the base metal. The minimum creep rates for FSW samples were, in general, lower than for the unwelded metal tested in equivalent conditions. In addition, when the applied stress was high, deformation concentrated in the parent metal. The creep strain became more and more homogeneous along the gauge length as testing stress decreased. A constitutive model, recently developed for describing the creep response of the base metal, was then used to rationalize the observed reduction in the minimum strain rate in FSW samples.
The Interplay of Thermal Gradient and Laser Process Parameters on the Mechanical Properties, Geometrical and Microstructural Characteristics of Laser-Cladded Titanium (Ti6Al4V) Alloy Composite Coatings
Authors: Fatoba Olawale Samuel , Jen Tien-Chien
Published: September 2023

With the development of laser surface modification techniques like direct laser metal deposition (DLMD), titanium alloy (TI6Al4V) may now have its entire base metal microstructure preserved while having its surface modified to have better characteristics. Numerous surface issues in the aerospace industry can be resolved using this method without changing the titanium alloy’s primary microstructure. As a result, titanium alloy is now more widely used in sectors outside of aerospace and automotive. This is made possible by fabricating metal composite coatings on titanium alloys using the same DLMD method. Any component can be repaired using this method, thereby extending the component’s life. The experimental process was carried out utilizing a 3000 W Ytterbium Laser System at the National Laser Centre of the CSIR in South Africa. Through the use of a laser system, AlCuTi/Ti6Al4V was created. The characterization of the materials for grinding and polishing was performed according to standard methods. There is a substantial correlation between the reinforcement feed rate, scan speed, and laser power components. Due to the significant role that aluminum reinforcement played and the presence of aluminum in the base metal structure, Ti-Al structures were also created. The reaction and solidification of the copper and aluminum reinforcements in the melt pool produced the dendritic phases visible in the microstructures. Compared to the base alloy, the microhardness’s highest value of 1117.2 HV1.0 is equivalent to a 69.1% enhancement in the hardness of the composite coatings. The enhanced hardness property is linked to the dendritic phases formed in the microstructures as a result of optimized process parameters. Tensile strengths of laser-clad ternary coatings also improved by 23%, 46.2%, 13.1%, 70%, 34.3%, and 51.7% when compared to titanium alloy substrates. The yield strengths of laser-clad ternary coatings improved by 19%, 46.7%, 12.9%, 69.3%, 34.7%, and 52.1% when compared to the titanium alloy substrate.
Titanium Impurity Control in V-Bearing Pig Iron Prepared via the Sodium Smelting of Vanadium–Titanium Magnetite
Authors: Bian Zhiwei , Cao Lei , Chen Desheng , Zhao Hongxin , Qi Tao , Wang Lina , Zhen Yulan
Published: September 2023

The sodium smelting of vanadium–titanium magnetite (VTM) can realize a multi-component comprehensive utilization of VTM. To broaden the application of the vanadium-bearing pig iron produced through this process, it is imperative to maintain the titanium content in molten iron at a very low level. In this study, the effects of temperature, the added amounts of sodium carbonate and anthracite, and the smelting time on the titanium content of molten iron were investigated using thermodynamic calculations and experiments. The results indicate that the introduction of sodium carbonate makes the reduction reaction of VTM a relatively low-temperature smelting system. In the smelting process, the Ti content in molten iron increases with the increase in temperature and decreases with the addition of sodium carbonate, while the amount of anthracite added has little effect on it. The appropriate technological parameters were determined as temperature: 1150–1250 °C, smelting time: ≥2 h, anthracite consumption: 25–35%, and sodium carbonate consumption: ≥60%. In addition, it was determined that the Ti impurities in the V-bearing pig iron were mainly (Ti,V)(C,N), CaTiO3, and Na2TiO3. All results obtained from this work contribute to the comprehensive utilization of VTM, and also provide theoretical support for the sodium smelting of VTM.
First-Principles Computation of Microscopic Mechanical Properties and Atomic Migration Behavior for Al4Si Aluminum Alloy
Authors: Huang Jingtao , Xue Jingteng , Li Mingwei , Cheng Yuan , Lai Zhonghong , Hu Jin , Zhou Fei , Qu Nan , Liu Yong , Zhu Jingchuan
Published: September 2023

In this paper, the interfacial behavior and the atom diffusion behavior of an Al4Si alloy were systematically investigated by means of first-principles calculations. The K-points and cutoff energy of the computational system were determined by convergence tests, and the surface energies for five different surfaces of Al4Si alloys were investigated. Among the five surfaces investigated for Al4Si, it was found that the (111) surface was the surface with the lowest surface energy. Subsequently, we investigated the interfacial stability of the (111) surface and found that there were two types of interfaces, the Al/Al interface and the Al/Si interface. The fracture energies and theoretical strengths of the two interfaces were calculated; the results show that the Al/Al interface had the highest interfacial strength, and the calculation of their electronic results explained the above phenomenon. Subsequently, we investigated the diffusion and migration behavior of Si atoms in the alloy system, mainly in the form of vacancies. We considered the diffusion of Si atoms in vacancies of Al and Si atoms, respectively; the results showed that Si atoms are more susceptible to diffusive migration to Al atomic vacancies than to Si atomic vacancies. The results of the calculations on the micromechanics of aluminum alloys, as well as the diffusion migration behavior, provide a theoretical basis for the further development of new aluminum alloys.
Influence of Applied Load and Sliding Distance on Wear Performance of AlSi7Mg0.6 Aluminum Alloy
Authors: Zhang Haibo , Zhao Yingxin , Pan Like , Zhao Aiguo
Published: September 2023

The wear performance of AlSi7Mg0.6 aluminum alloy, a casting aluminum alloy used in positioning devices for catenary systems of high-speed railways which fail frequently on lines where the speed of trains is higher than 300 m/s, is discussed in this study. It was estimated that sliding contact wear occurred and mainly contributed to the failure. To explore the competing mechanism for frictional wear failure, frictional experiments based on three groups of sliding distance (0.5 mm, 1.5 mm and 3.0 mm) and four groups of applied loads (20 N, 50 N, 100 N and 200 N) were implemented. Three-dimensional morphological observation results revealed that the wear volumes at a sliding distance of 0.5 mm were only about 1/10 of that at a sliding distance of 3.0 mm. It was also revealed that the wear volume based on a sliding distance of 3.0 mm and applied load of 20 N was still much larger than the wear volume under a sliding distance of 0.5 mm and applied load of 200 N. SEM observation of the microstructures revealed that abrasive wear was the dominant wear mechanism in dry sliding friction conditions. A simplified positioning device model was also established to study the influence of tension force on wear performance. The simulation results revealed that smaller tension force between the positioning support and positioning hook would lead to higher relative sliding distance and larger wear depth. Sliding contact friction should be avoided due to relatively large wear efficiency compared with rolling contact friction. Both experimental and simulation results suggested that proper tension force was preferred in assembling components which could ensure rolling contact friction rather than sliding contact friction.
Unveiling the Pharmacological Significance of Marine Streptomyces violaceusniger KS20: Isolation, Characterization, and Assessment of Its Biomedical Applications
Authors: Chakraborty Bidhayak , Shashiraj Kariyellappa Nagaraja , Kumar Raju Suresh , Bhat Meghashyama Prabhakara , Basavarajappa Dhanyakumara Shivapoojar , Almansour Abdulrahman I. , Perumal Karthikeyan , Nayaka Sreenivasa
Published: September 2023

Marine actinomycetes represent a highly favorable source of bioactive compounds and have been the mainstay of much research in recent years. Recent reports have shown that marine Streptomyces sp. can produce compounds with diverse and potent biological activities. Therefore, the key objective of the study was to isolate and screen a potential actinomycete from marine ecosystems of Devbagh and Tilmati beaches, Karwar. Streptomyces sp. KS20 was characterized and the ethyl acetate extract (EtOAc-Ex) was screened for biomedical applications. Streptomyces sp. KS20 produced grayish-white aerial and pale-yellow substrate mycelia and revealed an ancestral relationship with Streptomyces violaceusniger. Optimum growth of the organism was recorded at 30 °C and pH 7.0. The metabolite profiling of EtOAc-Ex expressed the existence of several bioactive metabolites, whereas the functional groups were indicated by Fourier transform infrared (FTIR) spectroscopy. A considerable antioxidant activity was shown for EtOAc-Ex with IC50 of 92.56 μg/mL. In addition to this, Streptomyces sp. KS20 exhibited significant antimicrobial properties, particularly against Escherichia coli, where a zone of inhibition measuring 36 ± 0.83 mm and a minimum inhibitory concentration (MIC) of 3.12 µg/mL were observed. The EtOAc-Ex even revealed significant antimycobacterial potency with IC50 of 6.25 μg/mL. Finally, the antiproliferative potentiality of EtOAc-Ex against A549 and PC-3 cell lines revealed a constant decline in cell viability while raising the concentration of EtOAc-Ex from 12.5 to 200 μg/mL. The IC50 values were determined as 94.73 μg/mL and 121.12 μg/mL for A549 and PC-3 cell lines, respectively. Overall, the exploration of secondary metabolites from marine Streptomyces sp. KS20 represents an exciting area of further research with the potential to discover novel bioactive compounds that could be developed into therapeutics for various medical applications.
Liver and Muscle Transcriptomes Differ in Mid-Lactation Cows Divergent in Feed Efficiency in the Presence or Absence of Supplemental Rumen-Protected Choline
Authors: Caputo Malia J. , Li Wenli , Kendall Sophia J. , Larsen Anna , Weigel Kent A. , White Heather M.
Published: September 2023

Improving dairy cow feed efficiency is critical to the sustainability and profitability of dairy production, yet the underlying mechanisms that contribute to individual cow variation in feed efficiency are not fully understood. The objectives of this study were to (1) identify genes and associated pathways that are altered in cows with high- or low-residual feed intake (RFI) using RNA sequencing, and (2) determine if rumen-protected choline supplementation during mid-lactation would influence performance or feed efficiency. Mid-lactation (134 ± 20 days in milk) multiparous Holstein cows were randomly assigned to either supplementation of 0 g/d supplementation (CTL; n = 32) or 30 g/d of a rumen-protected choline product (RPC; 13.2 g choline ion; n = 32; Balchem Corp., New Hampton, NY, USA). Residual feed intake was determined as dry matter intake regressed on milk energy output, days in milk, body weight change, metabolic body weight, and dietary treatment. The 12 cows with the highest RFI (low feed efficient; LE) and 12 cows with the lowest RFI (high feed efficient; HE), balanced by dietary treatment, were selected for blood, liver, and muscle analysis. No differences in production or feed efficiency were detected with RPC supplementation, although albumin was greater and arachidonic acid tended to be greater in RPC cows. Concentrations of β-hydroxybutyrate were greater in HE cows. Between HE and LE, 268 and 315 differentially expressed genes in liver and muscle tissue, respectively, were identified through RNA sequencing. Pathway analysis indicated differences in cell cycling, oxidative stress, and immunity in liver and differences in glucose and fatty acid pathways in muscle. The current work indicates that unique differences in liver and muscle post-absorptive nutrient metabolism contribute to sources of variation in feed efficiency and that differences in amino acid and fatty acid oxidation, cell cycling, and immune function should be further examined.
Cancer Cachexia: Underlying Mechanisms and Potential Therapeutic Interventions
Authors: Directo Dean , Lee Sang-Rok
Published: September 2023

Cancer cachexia, a multifactorial metabolic syndrome developed during malignant tumor growth, is characterized by an accelerated loss of body weight accompanied by the depletion of skeletal muscle mass. This debilitating condition is associated with muscle degradation, impaired immune function, reduced functional capacity, compromised quality of life, and diminished survival in cancer patients. Despite the lack of the known capability of fully reversing or ameliorating this condition, ongoing research is shedding light on promising preclinical approaches that target the disrupted mechanisms in the pathophysiology of cancer cachexia. This comprehensive review delves into critical aspects of cancer cachexia, including its underlying pathophysiological mechanisms, preclinical models for studying the progression of cancer cachexia, methods for clinical assessment, relevant biomarkers, and potential therapeutic strategies. These discussions collectively aim to contribute to the evolving foundation for effective, multifaceted counteractive strategies against this challenging condition.
High-Performance All-Optical Logic Operations Using Ψ-Shaped Silicon Waveguides at 1.55 μm
Authors: Kotb Amer , Zoiros Kyriakos E. , Guo Chunlei
Published: September 2023

We simulate with FDTD solutions a complete family of basic Boolean logic operations, which includes XOR, AND, OR, NOT, NOR, NAND, and XNOR, by using compact Ψ-shaped silicon-on-silica optical waveguides that are operated at a 1.55 μm telecommunications wavelength. Four identical slots and one microring resonator, all made of silicon deposited on silica, compose the adopted waveguide. The operating principle of these logic gates is based on the constructive and destructive interferences that result from the phase differences incurred by the launched input optical beams. The performance of these logic operations is evaluated against the contrast ratio (CR) metric. The obtained results suggest that the considered functions designed with the employed waveguide can be realized all-optically with higher CRs and faster speeds than other reported designs.