bluuebunny/crossref_metadata_2025 huggingface dataset:
Biogeography of Fungal Communities Associated with Pinus sylvestris L. and Picea abies (L.) H. Karst. along the Latitudinal Gradient in Europe
Authors: Mishcherikova Valeriia , Lynikienė Jūratė , Marčiulynas Adas , Gedminas Artūras , Prylutskyi Oleh , Marčiulynienė Diana , Menkis Audrius
Published: August 2023

We assessed the diversity and composition of fungal communities in different functional tissues and the rhizosphere soil of Pinus sylvestris and Picea abies stands along the latitudinal gradient of these tree species distributions in Europe to model possible changes in fungal communities imposed by climate change. For each tree species, living needles, shoots, roots, and the rhizosphere soil were sampled and subjected to high-throughput sequencing. Results showed that the latitude and the host tree species had a limited effect on the diversity and composition of fungal communities, which were largely explained by the environmental variables of each site and the substrate they colonize. The mean annual temperature and mean annual precipitation had a strong effect on root fungal communities, isothermality on needle fungal communities, mean temperature of the warmest quarter and precipitation of the driest month on shoot fungal communities, and precipitation seasonality on soil fungal communities. Fungal communities of both tree species are predicted to shift to habitats with a lower annual temperature amplitude and with increasing precipitation during the driest month, but the suitability of these habitats as compared to the present conditions is predicted to decrease in the future.
Pezizomycetes Genomes Reveal Diverse P450 Complements Characteristic of Saprotrophic and Ectomycorrhizal Lifestyles
Authors: Nsele Nomfundo Ntombizinhle , Padayachee Tiara , Nelson David R. , Syed Khajamohiddin
Published: August 2023

Cytochrome P450 monooxygenases (CYPs/P450s) are heme proteins that play a role in organisms’ primary and secondary metabolism. P450s play an important role in organism adaptation since lifestyle influences P450 composition in their genome. This phenomenon is well-documented in bacteria but less so in fungi. This study observed this phenomenon where diverse P450 complements were identified in saprophytic and ectomycorrhizal Pezizomycetes. Genome-wide data mining, annotation, and phylogenetic analysis of P450s in 19 Pezizomycetes revealed 668 P450s that can be grouped into 153 P450 families and 245 P450 subfamilies. Only four P450 families, namely, CYP51, CYP61, CYP5093, and CYP6001, are conserved across 19 Pezizomycetes, indicating their important role in these species. A total of 5 saprophyte Pezizomycetes have 103 P450 families, whereas 14 ectomycorrhizal Pezizomycetes have 89 P450 families. Only 39 P450 families were common, and 50 and 64 P450 families, respectively, were unique to ectomycorrhizal and saprophytic Pezizomycetes. These findings suggest that the switch from a saprophytic to an ectomycorrhizal lifestyle led to both the development of diverse P450 families as well as the loss of P450s, which led to the lowest P450 family diversity, despite the emergence of novel P450 families in ectomycorrhizal Pezizomycetes.
State of the Art in Robotic Surgery with Hugo RAS System: Feasibility, Safety and Clinical Applications
Authors: Prata Francesco , Ragusa Alberto , Tempesta Claudia , Iannuzzi Andrea , Tedesco Francesco , Cacciatore Loris , Raso Gianluigi , Civitella Angelo , Tuzzolo Piergiorgio , Callè Pasquale , Pira Matteo , Pino Matteo , Ricci Marco , Fantozzi Marco , Prata Salvatore M. , Anceschi Umberto , Simone Giuseppe , Scarpa Roberto M. , Papalia Rocco
Published: August 2023

Since its introduction in the early 2000s, robotic surgery has represented a significative innovation within a minimally invasive surgery approach. A variety of robotic platforms have been made available throughout the years, and the outcomes related to those platforms have been described in the literature for many types of surgeries. Medtronic’s HugoTM RAS system is one of the newest robotic generations launched, but because of its recent placing on the field, comprehensive clinical data are still lacking. The aim of the present state of the art is to address the current literature concerning the use of the HugoTM RAS robot in order to report its feasibility, safety and clinical applications in different surgical branches. Two reviewers independently conducted a search on the “PubMed” electronic database, using the keywords “Hugo” and “Hugo RAS”. After the initial screening of 35 results, a total of 15 articles concerning the Hugo RAS system were selected for the review, including both oncological and benign surgery. Patients’ demographic and baseline data were compared including, when available, docking system times, complications and oncological outcomes in the fields of urologic, gynecologic and general surgery. With reference to urological procedures, a total of 156 robot-assisted radical prostatectomies, 10 robot-assisted partial nephrectomies, and 5 robot-assisted adrenalectomies were performed, involving a total of 171 patients. The surgical branch in which the Hugo system found its major application was urology, which was followed by gynecology and general surgery. The Hugo RAS system by Medtronic represents an innovative and safe surgical platform, with excellent perspective for the future and different clinical applications in many surgical branches. More studies are needed to validate the safety and results from this new robotic platform.
Response of the Desertification Landscape Patterns to Spatial–Temporal Changes of Land Use: A Case Study of Salaxi in South China Karst
Authors: Shu Tian , Xiong Kangning , Zhang Ning
Published: August 2023

Land use change and karst desertification (KD) are interdependent. It is crucial to investigate the relationship between the KD landscape and spatial–temporal changes in land use for effective and sustainable KD management practices in karst plateau mountains. In this study, we analyzed the spatial and temporal characteristics, evolution in the pattern of land use, and KD in the Salaxi study area from 2009 to 2019, using the landscape pattern index and KD evolution trajectories, and discussed their response relationships. The results revealed the following: (1) In Salaxi, cultivated land predominantly transformed into shrubland, grassland, and woodland. The area of grassland, construction land, and garden land significantly increased, with respective increments of 379.85%, 157.14%, and 1847.81%. Conversely, the area of unutilized land decreased from 53.56 hm2 to 8.55 hm2, with the proportion declining from 0.62% to 0.10%. KD primarily occurs in shrubland, cultivated land, and woodland. (2) The areas of non-KD and potential KD have increased. There was a noticeable conversion of light and medium KD into potential KD, with areas of 1206.84 hm2 and 459.47 hm2, respectively. The KD landscape is dominated by stable and weakening ecological restoration. The comprehensive ranking of the incidence of soil KD in the study area is as follows: yellow soil > yellow-brown soil > coarse bone soil > limestone soil > purple soil. (3) The land use landscape index, the evenness index, and the fragmentation index in the demonstration area increased by 0.263, 0.120, and 0.534, respectively, while the KD landscape index, evenness index, and fragmentation index decreased by 0.360, 0.123, and 1.098, respectively. Additionally, the spreading index and aggregation index of the land use landscape decreased by 9.247 and 3.086, respectively, while the KD landscape’s spreading index and aggregation index increased by 6.688 and 0.430, respectively. Both the sub-dimension indexes of the land use landscape and the KD landscape increased by 0.009. Overall, the landscape pattern of KD changes in response to land use variations and different land types exhibited varying responses to KD. The study of KD and land use landscape patterns can provide references for national strategies on KD control and the development of ecological industries.
Risk Assessment and Prevention Planning for Collapse Geological Hazards Considering Extreme Rainfall—A Case Study of Laoshan District in Eastern China
Authors: Yu Peng , Dong Jie , Hao Hongwei , Xie Yongjian , Zhang Hui , Wang Jianshou , Zhu Chenghao , Guan Yong , Yu Haochen
Published: August 2023

Geological disasters refer to adverse geological phenomena that occur under the influence of natural or human factors and cause damage to human life and property. Establishing prevention and control zones based on geological disaster risk assessment results in land planning and management is crucial for ensuring safe regional development. In recent years, there has been an increase in extreme rainfall events, so it is necessary to conduct effective geological hazard and risk assessments for different extreme rainfall conditions. Based on the first national geological disaster risk survey results, this paper uses the analytic hierarchy process (AHP) combined with the information method (IM) to construct four extreme rainfall conditions, namely, 10-year, 20-year, 50-year, and 100-year return periods. The susceptibility, hazard, vulnerability, and risk of geological disasters in the Laoshan District in eastern China are evaluated, and prevention and control zones are established based on the evaluation results. The results show that: (1) There are 121 collapse geological disasters in Laoshan District, generally at a low susceptibility level. (2) A positive correlation exists between extreme rainfall and hazards/risks. With the rainfall condition changing from a 10-year return period to a 100-year return period, the proportion of high-hazard zones increased from 20% to 41%, and high-risk zones increased from 31% to 51%, respectively. The Receiver operating characteristic (ROC) proved that the assessment accuracy was acceptable. (3) Key, sub-key, and general prevention zones have been established, and corresponding prevention and control suggestions have been proposed, providing a reference for geological disaster prevention and early warning in other regions.
Homogenization of Urban Forests across the Subtropical Zones of China
Authors: Yang Guofu , Ouyang Yan , Hou Xiaoyu , Zhou Tianyi , Ge Ying , Lu Yijun , Wang Yue , Chang Jie
Published: August 2023

The composition of urban forests (UFs) exhibits homogenization among cities compared with rural forests (RFs) among different climate zones. However, the degree of homogenization in subtropical UFs and its difference from RFs remain unclear. In this study, we examined tree species composition and diversity in UFs in 19 cities in China’s subtropical zone with precipitation ranging from 458 to 1852 mm and compared them with RFs. We found that (1) the species composition similarity, Jaccard index (J~0.27), between UFs was significantly higher than that (J~0.15) of RFs, indicating biotic homogenization; (2) tree species richness, Simpson, Shannon–Wiener, and Pielou index of UFs converged along the precipitation gradient; (3) the similarity of tree composition between UFs increased as precipitation of the cities were more similar; (4) the UFs in the 19 cities contained a total of 932 tree species, among which the nonnative species were more prevalent than the native species, and the top 37 species with high frequency appeared in 80% of the cities; and (5) Salix babylonica, Ginkgo biloba, Platycladus orientalis, Juniperus chinensis, and other tree species were suitable for planting in UFs in subtropical zones, regardless of humidity. The findings contribute to the understanding of urban forest development and provide insights for implementing greening policies aimed at providing additional ecosystem services.
Assessing the Status and Challenges of Urban Land Administration Systems Using Framework for Effective Land Administration (FELA): A Case Study in Pakistan
Authors: Ahsan Muhammad Sheraz , Hussain Ejaz , Ali Zahir , Zevenbergen Jaap , Atif Salman , Koeva Mila , Waheed Abdul
Published: August 2023

The urban land administration system (LAS) of any country serves as a key pillar for good governance, resource planning, service delivery, infrastructure development, and revenue collection. To reform their LASs, countries need a thorough understanding of their existing context and global relevance. The goal of this paper is to examine the status and challenges of urban LASs in Pakistan using the United Nations Framework for Effective Land Administration (FELA). The exploratory case study method used in the paper employs a mixed approach, which includes FELA-based questionnaire surveys, group discussions, and desk reviews. A total of 525 urban LAS stakeholders, including owner-buyers, real estate agents, bankers, lawyers, and LAS organizations, participated in the activity. The results show that more than half of the stakeholders are not satisfied with existing urban LASs, their governance and accountability, laws, and policies. Corruption is prevalent mostly in government organizations. Fraud and joint ownership are the most common sources of dispute, with 67 percent of the respondents stating that the cases take more than two years to resolve in court. The financial aspect of urban LASs is suffering due to property undervaluation and low revenue collection. Manual data and record keeping in LASs further complicate the system, with 87 percent of all respondents interested in innovating the urban LAS using modern technologies. Furthermore, 92 percent of all respondents expressed the need to standardize the existing LASs. There is a lack of capacity and skills, and 89 percent of organizations’ respondents believe that human resources skilled in Geographical Information Systems (GIS) and Remote Sensing (RS) can improve the efficiency of urban LASs. There is a lack of partnership among LAS organizations and a gap in the accessibility of LAS-related quality information. The country’s vision of building smart cities can be realized through LAS standardization and 3D and GIS innovation.
Cultivable Endophyte Resources in Medicinal Plants and Effects on Hosts
Authors: Wang Yiming , Zhang Yongjing , Cong Hao , Li Changgen , Wu Jiaying , Li Ludan , Jiang Jihong , Cao Xiaoying
Published: August 2023

With the increasing demand for medicinal plants and the increasing shortage of resources, improving the quality and yield of medicinal plants and making more effective use of medicinal plants has become an urgent problem to be solved. During the growth of medicinal plants, various adversities can lead to nutrient loss and yield decline. Using traditional chemical pesticides to control the stress resistance of plants will cause serious pollution to the environment and even endanger human health. Therefore, it is necessary to find suitable pesticide substitutes from natural ingredients. As an important part of the microecology of medicinal plants, endophytes can promote the growth of medicinal plants, improve the stress tolerance of hosts, and promote the accumulation of active components of hosts. Endophytes have a more positive and direct impact on the host and can metabolize rich medicinal ingredients, so researchers pay attention to them. This paper reviews the research in the past five years, aiming to provide ideas for improving the quality of medicinal plants, developing more microbial resources, exploring more medicinal natural products, and providing help for the development of research on medicinal plants and endophytes.
Regulatory miRNAs and lncRNAs in Skin Cancer: A Narrative Review
Authors: Natarelli Nicole , Boby Aleena , Aflatooni Shaliz , Tran Jasmine Thuy , Diaz Michael Joseph , Taneja Kamil , Forouzandeh Mahtab
Published: August 2023

Non-coding RNAs (ncRNAs) have a significant regulatory role in the pathogenesis of skin cancer, despite the fact that protein-coding genes have generally been the focus of research efforts in the field. We comment on the actions of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) in the current review with an eye toward potential therapeutic treatments. LncRNAs are remarkably adaptable, acting as scaffolding, guides, or decoys to modify key signaling pathways (i.e., the Wnt/β-catenin pathway) and gene expression. As post-transcriptional gatekeepers, miRNAs control gene expression by attaching to messenger RNAs and causing their degradation or suppression during translation. Cell cycle regulation, cellular differentiation, and immunological responses are all affected by the dysregulation of miRNAs observed in skin cancer. NcRNAs also show promise as diagnostic biomarkers and prognostic indicators. Unraveling the complexity of the regulatory networks governed by ncRNAs in skin cancer offers unprecedented opportunities for groundbreaking targeted therapies, revolutionizing the landscape of dermatologic care.
Effect of Non-Linear Properties of Intermediate Layer on Sliding Contact of Homogeneous and Coated Elastic Solids
Authors: Torskaya Elena V. , Stepanov Fedor I.
Published: August 2023

Lubrication in the contact area can be considered as a viscoelastic layer, especially in the presence of particles in it, or under conditions of low temperatures. The properties of this layer are often non-linear, in particular, they depend on local pressure. The paper presents a formulation and numerical-analytical method for solving the contact problem in the presence of viscoelastic layers, the compliance of which depends on the applied pressure and is included in the formulation as the corresponding operator. The layer is homogeneous or coated elastic half-space. For the selected type of operator, the influence of parameters, which characterize the nonlinearity of the model, on the distribution of contact pressure and the coefficient of friction due to hysteresis losses was analyzed. It is shown that for the nonlinear model, the maximum contact pressures are higher, and the friction coefficient is lower than for the linear model with constant compliance. The effect of non-linearity for a wide range of sliding velocities is considered. An analysis of principal shear and tensile-compressive stresses for a homogeneous elastic half-space and for a coating, in particular, for a coating-substrate interface, was also carried out.
Improving the Mechanical Properties of a Lattice Structure Composed of Struts with a Tri-Directional Elliptical Cylindrical Section via Selective Laser Melting
Authors: Xiao Xiong , Xie Liangwen , Zhu Xianyong , Liu Jiaan , Luo Yanru , Song Peng , Zhao Jiali , Zhang Jinyuan , Wang Chen , Yang Song , Wu Peng , You Xiangmi , Jiang Cheng
Published: August 2023

In recent years, lattice structures produced via additive manufacturing have been increasingly investigated for their unique mechanical properties and the flexible and diverse approaches available to design them. The design of a strut with variable cross-sections in a lattice structure is required to improve the mechanical properties. In this study, a lattice structure design method based on a strut cross-section composed of a mixture of three ellipses named a tri-directional elliptical cylindrical section (TEC) is proposed. The lattice structures were fabricated via the selective laser melting of 316L alloy. The finite element analysis results show that the TEC strut possessed the high mechanical properties of lattice structures. Compression experiments confirmed that the novel lattice structure with the TEC strut exhibited increases in the elastic modulus, compressive yield strength, and energy absorption capacity of 24.99%, 21.66%, and 20.50%, respectively, compared with the conventional lattice structure at an equal level of porosity.
Early-Age Cracking Behavior of Concrete Slabs with GFRP Reinforcement
Authors: Roghani Hossein , Nanni Antonio , Bolander John E.
Published: August 2023

This paper reports on a combined experimental and numerical modeling investigation of cracking of concrete slabs with GFRP reinforcement. At this stage of the project, attention is given to early-age cracking driven by plastic shrinkage, preceding longer term considerations of cracking resistance over the service life of field applications. Of interest is the effectiveness of GFRP reinforcement in restricting plastic shrinkage cracking. Nine small-scale slab specimens were subjected to controlled evaporation rates. Images of crack development were acquired periodically, from which crack width estimations were made. Comparisons were made between slabs reinforced with conventional steel and those reinforced with GFRP, along with control specimens lacking reinforcement. During the period of plastic shrinkage, the time of crack initiation and subsequent crack openings do not appear to be influenced by the presence of the reinforcing bars. To understand this behavior, six early-age bond tests were conducted for both types of the bars after 1, 2, and 3 h exposure to the controlled evaporation rate. In addition, concrete strength development and time of settings were measured using penetration resistance tests on a representative mortar. The numerical modeling component of this research is based on a Voronoi cell lattice model; in this approach, the relative humidity, temperature, and displacement fields are discretized in three-dimensions, allowing for a comprehensive investigation of material behavior within the controlled environment. Based on the measured bond properties, our simulations confirm that the reinforcing bars restrict crack development, though they do not prevent it entirely.
The Effects of MgO and Al2O3 Content in Sinter on the Softening–Melting Properties of Mixed Ferrous Burden
Authors: Li Zhexi , Li Tingle , Sun Changyu , Yang Songtao , Wang Qi
Published: August 2023

The softening–melting properties of mixed ferrous burden made from high-basicity sinter with increased MgO and Al2O3 content and acid pellets was investigated for optimization. The influences of MgO and Al2O3 are discussed with the aid of phase analysis. The results showed that, with decreasing MgO mass%/Al2O3 mass% in mixed burden, all the softening–melting characteristic temperatures decreased, which can be attributed to the low melting temperature and viscosity of the slag caused by MgO and Al2O3. The permeability of the melting zone deteriorated again when MgO mass%/Al2O3 mass% decreased to a certain content. The softening interval widened slightly at first and then narrowed, while the melting interval first increased slightly and then increased greatly later. It can be deduced that the softening properties were improved, but the melting properties were worsened. Under comprehensive consideration of its softening–melting properties, permeability, iron ore reduction and the thermal state of the blast furnace hearth, the optimal softening–melting properties of a mixed ferrous burden with MgO mass%/Al2O3 mass% of 0.82 is optimal.
Aluminium Matrix Composites Reinforced with AlCrFeMnNi HEA Particulates: Microstructure, Mechanical and Corrosion Properties
Authors: Ananiadis Elias A. , Karantzalis Alexandros E. , Sfikas Athanasios K. , Georgatis Emmanuel , Matikas Theodore E.
Published: August 2023

Novel aluminium matrix composites have been fabricated using a powder metallurgy route with reinforcement phase particles of high entropy alloy (HEA) consisting of third transition metals. These new composites are studied as far as their microstructure (SEM, XRD), basic mechanical properties (hardness, elastic modulus) and creep response using nanoindentation techniques are concerned. Wear (sliding wear tests) and corrosion behaviour (in 3.5 wt.% NaCl environment) were also assessed. It was observed that, microstructurally, no secondary intermetallic phases were formed. Hardness and wear resistance seemed to increase with the increase in HEA particles, and in terms of corrosion, the composites exhibited susceptibility to localised forms. Nanoindentation techniques and creep response showed findings that are connected with the deformation nature of both the Al matrix and the HEA reinforcing phase.
Tool Wear Monitoring Based on the Gray Wolf Optimized Variational Mode Decomposition Algorithm and Hilbert–Huang Transformation in Machining Stainless Steel
Authors: Wei Wei , He Guichao , Yang Jingyi , Li Guangxian , Ding Songlin
Published: August 2023

The online monitoring and prediction of tool wear are important to maintain the stability of machining processes. In most cases, the tool wear condition can be evaluated by signals such as force, sound, vibration, and temperature, which are often processed via Fourier-transform based methods, typically, the short-time Fourier transform (STFT). However, the fixed-width window function in STFT has many limitations. In this paper, a novel tool wear monitoring method based on variational mode decomposition (VMD) and Hilbert–Huang transformation (HHT) were developed to monitor the wear of carbide tools in machining stainless steel. In this method, the intrinsic mode function (IMF) was used as the fitness function, and the (K alpha) parameter sets for VMD were optimized by the gray wolf optimization (GWO). The results show that the characteristic frequency in the GWO-VMD-HHT method is more significant with no aliasing compared with the EMD-HHT method, and an obvious characteristic frequency shift phenomenon is present. By utilizing the energy value of IMF3 as the feature to classify the wear state of the cutting tool, the increase of energy reached 85.48% when 260–315 milling passes were in severe wear state. GWO, which can accurately find the best parameters for VMD, not only solves the problem that the Entropy Function is not suitable for force signals, but also provides reference for the selection of parameters of VMD.
Waypoint Generation in Satellite Images Based on a CNN for Outdoor UGV Navigation
Authors: Sánchez Manuel , Morales Jesús , Martínez Jorge L.
Published: August 2023

Moving on paths or trails present in natural environments makes autonomous navigation of unmanned ground vehicles (UGV) simpler and safer. In this sense, aerial photographs provide a lot of information of wide areas that can be employed to detect paths for UGV usage. This paper proposes the extraction of paths from a geo-referenced satellite image centered at the current UGV position. Its pixels are individually classified as being part of a path or not using a convolutional neural network (CNN) which has been trained using synthetic data. Then, successive distant waypoints inside the detected paths are generated to achieve a given goal. This processing has been successfully tested on the Andabata mobile robot, which follows the list of waypoints in a reactive way based on a three-dimensional (3D) light detection and ranging (LiDAR) sensor.
Digital Twin Certified: Employing Virtual Testing of Digital Twins in Manufacturing to Ensure Quality Products
Authors: Grieves Michael
Published: August 2023

Quality products are a main focus for manufacturers. Product users only determine a product to be a quality product if it performs in operation to the user’s perceived standard. Product manufactures need to take a product lifecycle quality (PLQ) perspective of quality and not simply focus on manufacturing quality control, which is more accurately specification control. Manufacturing is the key phase where products take their physical form. There are increasing costs and decreasing risks of different physical quality strategies. The information provided using digital twins and virtual testing promises to be both low risk and cost and has the potential to predict what the customer will experience in operation by testing products passively with data and actively with simulation to destruction. Digital Twin Certified (DTC) is proposed as the methodology for accomplishing this. DTC will be especially important for the adoption of additive manufacturing.
Imputing Phylogenetic Trees Using Tropical Polytopes over the Space of Phylogenetic Trees
Authors: Yoshida Ruriko
Published: August 2023

When we apply comparative phylogenetic analyses to genome data, it poses a significant problem and challenge that some of the given species (or taxa) often have missing genes (i.e., data). In such a case, we have to impute a missing part of a gene tree from a sample of gene trees. In this short paper, we propose a novel method to infer the missing part of a phylogenetic tree using an analogue of a classical linear regression in the setting of tropical geometry. In our approach, we consider a tropical polytope, a convex hull with respect to the tropical metric closest to the data points. We show a condition that we can guarantee that an estimated tree from the method has at most a Robinson–Foulds (RF) distance of four from the ground truth, and computational experiments with simulated data and empirical data from Clavicipitaceae, which contains more than 4000 genes, show the method works well.
Differential Properties of Jacobi-Sobolev Polynomials and Electrostatic Interpretation
Authors: Pijeira-Cabrera Héctor , Quintero-Roba Javier , Toribio-Milane Juan
Published: August 2023

We study the sequence of monic polynomials {Sn}n⩾0, orthogonal with respect to the Jacobi-Sobolev inner product ⟨f,g⟩s=∫−11f(x)g(x)dμα,β(x)+∑j=1N∑k=0djλj,kf(k)(cj)g(k)(cj), where N,dj∈Z+, λj,k⩾0, dμα,β(x)=(1−x)α(1+x)βdx, α,β>−1, and cj∈R∖(−1,1). A connection formula that relates the Sobolev polynomials Sn with the Jacobi polynomials is provided, as well as the ladder differential operators for the sequence {Sn}n⩾0 and a second-order differential equation with a polynomial coefficient that they satisfied. We give sufficient conditions under which the zeros of a wide class of Jacobi-Sobolev polynomials can be interpreted as the solution of an electrostatic equilibrium problem of n unit charges moving in the presence of a logarithmic potential. Several examples are presented to illustrate this interpretation.
Quantum Computing in Telecommunication—A Survey
Authors: Phillipson Frank
Published: August 2023

Quantum computing, an emerging paradigm based on the principles of quantum mechanics, has the potential to revolutionise various industries, including Telecommunications. This paper explores the transformative impact of quantum computing on the telecommunication market, focusing on its applications in solving computationally intensive problems. By leveraging the inherent properties of quantum systems, such as superposition and entanglement, quantum computers offer the promise of exponential computational speedup and enhanced problem-solving capabilities. This paper provides an in-depth analysis of the current state of quantum computing in telecommunication, examining key algorithms and approaches, discussing potential use cases, and highlighting the challenges and future prospects of this disruptive technology.
Baseline Clinical Characteristics and Incidence of Chronic Thromboembolic Pulmonary Hypertension Patients in Latvia, 2019–2020
Authors: Kauliņš Ričards , Rudzītis Ainārs , Lejnieks Aivars , Kigitoviča Dana , Skride Andris
Published: August 2023

Background: Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare and progressive condition; however, the true characteristics of CTEPH are still unknown, as notable regional variations exist in terms of patients’ age, baseline hemodynamic data, and management choices. This report aims to investigate the baseline clinical characteristics, incidence, and risk factors associated with CTEPH patients in Latvia from 2019 to 2020. Methods: The data were analyzed from a prospective, nationwide, Latvian pulmonary hypertension registry for incident CTEPH cases. The patients’ clinical characteristics were assessed at the time of diagnosis. Results: During the course of this study, a cohort of 13 patients with CTEPH were included for analysis. Among the enrolled CTEPH patients, most exhibited low exercise and functional capacity, with a median (±IQR) 6 min walk distance of 300.0 (±150.0) m. The median values (±IQR) for mean pulmonary artery pressure and pulmonary vascular resistance were 40.0 ± 13.0 mmHg and 7.35 ± 2.82 Wood units, respectively. The most common risk factors for CTEPH were a history of acute pulmonary embolism and a blood group other than O. Conclusions: The findings of this report revealed the characteristics of the Latvian CTEPH population, indicating that a significant proportion of patients are elderly individuals with multiple comorbidities.
Perspective on the Role of Gut Microbiome in the Treatment of Hepatocellular Carcinoma with Immune Checkpoint Inhibitors
Authors: Abenavoli Ludovico , Montori Michele , Svegliati Baroni Gianluca , Argenziano Maria Eva , Giorgi Francesca , Scarlata Giuseppe Guido Maria , Ponziani Francesca , Scarpellini Emidio
Published: August 2023

Background and Objectives: Hepatocellular carcinoma (HCC) is the leading cause of liver cancer worldwide and has a high mortality rate. Its incidence has increased due to metabolic-associated liver disease (MAFLD) epidemics. Liver transplantation and surgery remain the most resolute measures. Despite the optimistic use of multi-kinase inhibitors, namely sorafenib, the co-existence of chronic liver disease made the response rate low in these patients. Immune checkpoint inhibitors (ICIs) have become a promising hope for certain advanced solid tumors and, also, for advanced HCC. Unfortunately, a large cohort of patients with HCC fail to respond to immunotherapy. Materials and Methods: We conducted a narrative search on the main medical databases for original articles, reviews, meta-analyses, randomized clinical trials, and case series using the following keywords and acronyms and their associations: hepatocellular carcinoma, immunotherapy, checkpoint inhibitors, gut microbiota, and fecal microbiota transplantation. Results: ICIs are a promising and sufficiently safe treatment option for HCC. In detail, they have significantly improved survival and prognosis in these patients vs. sorafenib. Although there are several highlighted mechanisms of resistance, the gut microbiota signature can be used both as a response biomarker and as an effect enhancer. Practically, probiotic dose-finding and fecal microbiota transplantation are the weapons that can be used to increase ICI’s treatment-response-reducing resistance mechanisms. Conclusion: Immunotherapy has been a significant step-up in HCC treatment, and gut microbiota modulation is an effective liaison to increase its efficacy.
Micro End Mill Capability Improvement Due to Processing by Fast Argon Atoms and Deposition of Wear-Resistant Coating
Authors: Grigoriev Sergey , Metel Alexander , Mustafaev Enver , Melnik Yury , Volosova Marina
Published: August 2023

Micro-milling is widely used to make micro-channels in various fields. In this study, micro-milling of rectangular bronze microchannels was carried out with carbide end mills with a diameter of 1 mm, processed with fast argon atoms, and coated with anti-friction wear-resistant titanium diboride. It was shown that the removal of a 3 µm thick surface layer from a micro end mill with fast argon atoms makes it possible to reduce the cutting edge radius of the tool to 1.2 µm, which is three times lower than the minimum value of 4 µm achievable in mechanical manufacturing. The subsequent deposition of a 3 μm thick anti-friction coating results in a wear-resistant micro end mill with original geometric parameters but improved performance. The surface roughness of the machined bronze microchannel significantly decreased, and the burrs above the groove practically disappeared after micro-milling.
Interfacial Stress Development and Cracking Susceptibility during Laser Powder Bed Fusion of Random TiB2-Particle-Reinforced AlSi10Mg Matrix Composites
Authors: Ma Chenglong , Fang Ziyu , Wu Meiping , Miao Xiaojin , Wang Quanlong
Published: August 2023

A sequentially coupled multi-phase thermo-mechanical model for laser powder bed fusion (LPBF) of Al-based composites reinforced by 1 wt.% random TiB2 micron particles was established. Due to the remarkable difference in thermophysical properties, the maximum thermal stress was predicted at the TiB2/Al matrix interface and formed at the liquid–solid transition stage. Meanwhile, complicated evolution curves of temperature, strain, and strain rate were predicted with the laser moving time during the solidification stage. To evaluate the interface cracking susceptibilities of micron-TiB2/AlSi10Mg composites, the flow stress of the matrix was calculated, instead of ultimate tensile strength, based on the physical constitutive relationship. From the comparison between the calculated flow stress and the simulated Von Mise equivalent stress, it was found that an increase in TiB2 particle size was inclined to induce a larger interfacial stress than the calculated flow stress, therefore increasing the interfacial crack tendency, which was also effectively verified by the experimental results.
Optimization of Processing Parameters of Aluminum Alloy Cylindrical Parts Based on Response Surface Method during Hydromechanical Deep Drawing
Authors: Pan Yufeng , Cai Gaoshen
Published: August 2023

Aluminum alloy has been proposed as one of the next generation of lightweight body structure materials, which is widely used in the main components of the aerospace field. In order to realize efficient and accurate forming of aluminum alloy cylindrical parts, the response surface method combined with finite element simulation was used to optimize the key processing parameters during the hydromechanical deep drawing process. Three processing parameters of friction coefficient, pressure rate, and fillet radius of the die were selected as the optimization variables, and the maximum thinning rate of cylindrical parts was selected as the optimization evaluation index. The Box–Behnken design was selected to design the experiment scheme. A quadratic response model between the maximum thinning rate and the processing parameters was established by the response surface analysis software Design Expert for experimental design and data analysis. The optimal processing parameter combination was obtained through this model. The results show that the optimal conditions of maximum thinning rate can be met when the pressure rate is 11.6 MPa/s, the friction coefficient is 0.15, and the fillet radius of the die is 8 mm. Finally, the experimental verification was carried out by using the optimized combination of process parameters. It was found that the error between the experimental results and the predicted simulation results was within 5%, and the cylindrical parts which met the quality requirements were finally formed.
Coexistence of Intermetallic Complexions and Bulk Particles in Grain Boundaries in the ZEK100 Alloy
Authors: Straumal Boris , Tsoy Kristina , Druzhinin Aleksandr , Orlov Valery , Khrapova Natalya , Davdian Gregory , Gerstein Gregory , Straumal Alexander
Published: August 2023

Magnesium-based alloys are highly sought after in the industry due to their lightweight and reliable strength. However, the hexagonal crystal structure of magnesium results in the mechanical properties’ anisotropy. This anisotropy is effectively addressed by alloying magnesium with elements like zirconium, zinc, and rare earth metals (REM). The addition of these elements promotes rapid seed formation, yielding small grains with a uniform orientation distribution, thereby reducing anisotropy. Despite these benefits, the formation of intermetallic phases (IP) containing Zn, Zr, and REM within the microstructure can be a concern. Some of these IP phases can be exceedingly hard and brittle, thus weakening the material by providing easy pathways for crack propagation along grain boundaries (GBs). This issue becomes particularly significant if intermetallic phases form continuous layers along the entire GB between two neighboring GB triple junctions, a phenomenon known as complete GB wetting. To mitigate the risks associated with complete GB wetting and prevent the weakening of the alloy’s structure, understanding the potential occurrence of a GB wetting phase transition and how to control continuous GB layers of IP phases becomes crucial. In the investigation of a commercial magnesium alloy, ZEK100, the GB wetting phase transition (i.e., between complete and partial GB wetting) was successfully studied and confirmed. Notably, complete GB wetting was observed at temperatures near the liquidus point of the alloy. However, at lower temperatures, a coexistence of a nano-scaled precipitate film and bulk particles with nonzero contact angles within the same GB was observed. This insight into the wetting transition characteristics holds potential to expand the range of applications for the present alloy in the industry. By understanding and controlling GB wetting phenomena, the alloy’s mechanical properties and structural integrity can be enhanced, paving the way for its wider utilization in various industrial applications.
An Investigation of Spiral Dislocation Sources Using Discrete Dislocation Dynamics (DDD) Simulations
Authors: Li Luo , Khraishi Tariq
Published: August 2023

Discrete Dislocation Dynamics (DDD) simulations are a powerful simulation methodology that can predict a crystalline material’s constitutive behavior based on its loading conditions and micro-constituent population/distribution. In this paper, a 3D DDD model with spiral dislocation sources is developed to study size-dependent plasticity in a pure metal material (taken here as Aluminum). It also shows, for the first time, multipole simulations of spirals and how they interact with one another. In addition, this paper also discusses how the free surface of a crystalline material affects the plasticity generation of the spiral dislocation. The surface effect is implemented using the Distributed Dislocation Method. One of the main results from this work, shown here for the first time, is that spiral dislocations can result in traditional Frank–Read sources (edge or screw character) in a crystal. Another important result from this paper is that with more dislocation sources, the plastic flow inside the material is more continuous, which results in a lowering of the flow stress. Lastly, the multipole interaction of the spiral dislocations resulted in a steady-state fan-shaped action for these dislocation sources.
The Optimization of Welding Spots’ Arrangement in A-Pillar Patchwork Blank Hot Stamping
Authors: Li Wenfeng , Zhang Zhiqiang , Jia Hongjie , Ren Mingwen
Published: August 2023

With increasingly severe environmental problems, energy saving and environmental protection have become two important issues to be solved in the automobile industry. Patchwork blank hot-stamping technology can be used to obtain light-weight and high-strength parts and is thus increasingly used in the manufacture of autobody parts. Because the main blank and the patched blank need to be connected through spot welding before forming, the welding spots’ arrangement has a great influence on the formability of the part. In this study, a thermal–mechanical coupling finite element analysis model of A-pillar patchwork blanks was established. With the thickness of the patched blank, the distance between the welding spot and the external contour of the patched blank, and the number of welding spots as optimization variables, together with the maximum thinning rate and the maximum welding spot force as objectives, the influence of welding spot arrangement on forming quality was analyzed, and the welding spots’ arrangement was optimized using a central composite design (CCD), the response surface method (RSM), and the genetic algorithm (GA). The results showed that when the initial welding spot was located close to the contour of the patched blank, the bending moment was greater when the weld spot passed through the die corner, leading to the rupture of the welding spot or its surrounding base material due to the greater thinning rate. When the patched blank was thicker than the main blank, the main blank cracked during the forming process due to a greater increase in the thinning rate. The optimal solution of the weld spot arrangement on the A-pillar patchwork blanks was a 1.2 mm thick main blank, 0.8 mm thick patched blank, a distance of 29 mm between the weld spot and the contour line of the patched blank, and 16 weld spots. Hot-stamping experiments were conducted using the optimized weld spots’ arrangement, and high-quality parts were obtained.
A Comprehensive Study of CsSnI3-Based Perovskite Solar Cells with Different Hole Transporting Layers and Back Contacts
Authors: Seyed-Talebi Seyedeh Mozhgan , Mahmoudi Mehrnaz , Lee Chih-Hao
Published: August 2023

By an abrupt rise in the power conservation efficiency (PCE) of perovskite solar cells (PSCs) within a short span of time, the instability and toxicity of lead were raised as major hurdles in the path toward their commercialization. The usage of an inorganic lead-free CsSnI3-based halide perovskite offers the advantages of enhancing the stability and degradation resistance of devices, reducing the cost of devices, and minimizing the recombination of generated carriers. The simulated standard device using a 1D simulator like solar cell capacitance simulator (SCAPS) with Spiro-OMeTAD hole transporting layer (HTL) at perovskite thickness of 330 nm is in good agreement with the previous experimental result (12.96%). By changing the perovskite thickness and work operating temperature, the maximum efficiency of 18.15% is calculated for standard devices at a perovskite thickness of 800 nm. Then, the effects of replacement of Spiro-OMeTAD with other HTLs including Cu2O, CuI, CuSCN, CuSbS2, Cu2ZnSnSe4, CBTS, CuO, MoS2, MoOx, MoO3, PTAA, P3HT, and PEDOT:PSS on photovoltaic characteristics were calculated. The device with Cu2ZnSnSe4 hole transport in the same condition shows the highest efficiency of 21.63%. The back contact also changed by considering different metals such as Ag, Cu, Fe, C, Au, W, Ni, Pd, Pt, and Se. The outcomes provide valuable insights into the efficiency improvement of CsSnI3-based PSCs by Spiro-OMeTAD substitution with other HTLs, and back-contact modification upon the comprehensive analysis of 120 devices with different configurations.
Low-Temperature Adaptive Dual-Network MXene Nanocomposite Hydrogel as Flexible Wearable Strain Sensors
Authors: Chen Kai , Lai Wenzhong , Xiao Wangchuan , Li Lumin , Huang Shijun , Xiao Xiufeng
Published: August 2023

Flexible electronic devices and conductive materials can be used as wearable sensors to detect human motions. However, the existing hydrogels generally have problems of weak tensile capacity, insufficient durability, and being easy to freeze at low temperatures, which greatly affect their application in the field of wearable devices. In this paper, glycerol was partially replaced by water as the solvent, agar was thermally dissolved to initiate acrylamide polymerization, and MXene was used as a conductive filler and initiator promoter to form the double network MXene-PAM/Agar organic hydrogel. The presence of MXene makes the hydrogel produce more conductive paths and enforces the hydrogel’s higher conductivity (1.02 S·m−1). The mechanical properties of hydrogels were enhanced by the double network structure, and the hydrogel had high stretchability (1300%). In addition, the hydrogel-based wearable strain sensor exhibited good sensitivity over a wide strain range (GF = 2.99, 0–200% strain). The strain sensor based on MXene-PAM/Agar hydrogel was capable of real-time monitoring of human movement signals such as fingers, wrists, arms, etc. and could maintain good working conditions even in cold environments (−26 °C). Hence, we are of the opinion that delving into this hydrogel holds the potential to broaden the scope of utilizing conductive hydrogels as flexible and wearable strain sensors, especially in chilly environments.