bluuebunny/crossref_metadata_2025 huggingface dataset:
Research Staff COVID-19 Pandemic Survey-Results from the Prevention and Early Treatment of Acute Lung Injury (PETAL) Network
Authors: Gill Jasreen Kaur , Bissonette Andrew , Cook Aaron A. , Jaehne Anja Kathrin , Day Jacqueline , Renaud Sheri , Jacobsen Gordon , Nelson Kristine , Kozikowski Lori-Ann , Jayaprakash Namita , Gardner-Gray Jayna , Swiderek Jennifer , Oldmixon Cathryn F. , Ringwood Nancy J. , Sherwin Robert L. , Williams Mark D. , Gupta Arielle Hodari , Johnson Nicholas J. , Hyzy Robert C. , Park Pauline K. , Rivers Emanuel P. ,   on behalf of the National Heart, Lung and Blood Institute PETAL Clinical Trials Network
Published: September 2023

Objectives: There is a lack of knowledge about the challenges of researchers who continued in-person research during the early phases of the COVID-19 pandemic. Design: Electronic survey assessing work-related exposure to COVID-19, logistical challenges, and procedural changes during the first year of the COVID-19 pandemic on clinical research. Setting: National Heart, Lung, and Blood Institute-sponsored Prevention and Early Treatment of Acute Lung Injury Clinical Trial Network Centers. Subjects: Research staff at research Network Sites. Measurements and Main Results: The 37-question survey was completed by 277 individuals from 24 states between 29 September 2020, and 12 December 2020, yielding a response rate of 37.7%. Most respondents (91.5%) indicated that non-COVID-19 research was affected by COVID-19 research studies. In response to the COVID-19 pandemic, 20% of respondents were reassigned to different roles at their institution. Many survey takers were exposed to COVID-19 (56%), with more than 50% of researchers requiring a COVID-19 test and 8% testing positive. The fear of infection was 2.7-times higher compared to pre-COVID-19 times. Shortages of personal protective equipment were encountered by 34% of respondents, primarily due to lack of access to N95 masks, followed by gowns and protective eyewear. Personal protective equipment reallocation from research to clinical use was reported by 31% of respondents. Most of the respondents (88.5%), despite these logistical challenges, indicated their willingness to enroll COVID-19 patients. Conclusions: During the first year of the COVID-19 pandemic, members of the research network were engaged in COVID-19 research despite logistical challenges, limited access to personal protective equipment, and fear of exposure. The research network’s survey experience can inform ongoing policy discussions to create research enterprises that can dexterously refocus research to address the knowledge gaps associated with novel public health emergencies while mitigating the effect of pandemics on existing research projects and research personnel.
Efficient Hyperbolic Perceptron for Image Classification
Authors: Ahsan Ahmad Omar , Tang Susanna , Peng Wei
Published: September 2023

Deep neural networks, often equipped with powerful auto-optimization tools, find widespread use in diverse domains like NLP and computer vision. However, traditional neural architectures come with specific inductive biases, designed to reduce parameter search space, cut computational costs, or introduce domain expertise into the network design. In contrast, multilayer perceptrons (MLPs) offer greater freedom and lower inductive bias than convolutional neural networks (CNNs), making them versatile for learning complex patterns. Despite their flexibility, most neural architectures operate in a flat Euclidean space, which may not be optimal for various data types, particularly those with hierarchical correlations. In this paper, we move one step further by introducing the hyperbolic Res-MLP (HR-MLP), an architecture extending the attention-free MLP to a non-Euclidean space. HR-MLP leverages fully hyperbolic layers for feature embeddings and end-to-end image classification. Our novel Lorentz cross-patch and cross-channel layers enable direct hyperbolic operations with fewer parameters, facilitating faster training and superior performance compared to Euclidean counterparts. Experimental results on CIFAR10, CIFAR100, and MiniImageNet confirm HR-MLP’s competitive and improved performance.
WB Score: A Novel Methodology for Visual Classifier Selection in Increasingly Noisy Datasets
Authors: Billa Wagner S. , Negri Rogério G. , Santos Leonardo B. L.
Published: September 2023

This article addresses the challenges of selecting robust classifiers with increasing noise levels in real-world scenarios. We propose the WB Score methodology, which enables the identification of reliable classifiers for deployment in noisy environments. The methodology addresses four significant challenges that are commonly encountered: (i) Ensuring classifiers possess robustness to noise; (ii) Overcoming the difficulty of obtaining representative data that captures real-world noise; (iii) Addressing the complexity of detecting noise, making it challenging to differentiate it from natural variations in the data; and (iv) Meeting the requirement for classifiers capable of efficiently handling noise, allowing prompt responses for decision-making. WB Score provides a comprehensive approach for classifier assessment and selection to address these challenges. We analyze five classic datasets and one customized flooding dataset in São Paulo. The results demonstrate the practical effect of using the WB Score methodology is the enhanced ability to select robust classifiers for datasets in noisy real-world scenarios. Compared with similar techniques, the improvement centers around providing a visual and intuitive output, enhancing the understanding of classifier resilience against noise, and streamlining the decision-making process.
Genetic Diversity and Population Structure Analysis of Tree Peony (Paeonia Section Moutan DC.) Germplasm Using Sixteen Functional SSR Markers
Authors: Guo Qi , Xue Xian , Hu Xiaoliang , He Yinglong , Wei Shuo , Liu Shaodan , Zhao Guodong , Wang Zhanying , Hou Xiaogai
Published: September 2023

Tree peony (Paeonia section Moutan DC.) is a traditional ornamental flower of China, which has thousands of varieties with different flower colors and types after a long history of natural selection and artificial breeding. However, tree peony is a perennial woody plant with a long breeding, and there are still significant challenges to accelerate the process of genetic improvement of important ornamental traits. In this study, a total of sixteen primer pairs with high polymorphism and good universality were selected from the initial pool of 115 SSR markers. The SSR marker set was derived from published papers on the genetic linkage map and association analysis of tree peony. Furthermore, we conducted a genetic diversity and population structure analysis on 322 tree peony cultivars using molecular markers with functional. These SSRs amplified a total of 391 alleles, the average number of different alleles was 5.113 alleles across all loci. The average Shannon’s information index, gene diversity and polymorphism information content were 0.842, 0.532, and 0.503 over all loci, respectively. Population genetic diversity analysis indicated that the average expected heterozygosity of the total population was larger than the observed heterozygosity, showing the presence of a certain degree of heterozygous deletion phenomenon. The Japan varieties had the richest diversity with the highest H (0.508) and PIC (0.479) values. The Zhongyuan varieties showed the greatest variation may be related to its longstanding cultivation history. Moreover, the STRUCTURE and principal coordinate analyses indicated that 322 tree peony individuals from five populations were grouped into two clusters. An analysis of molecular variance demonstrated significant genetic diversity among different populations. This research may contribute to the sustainable management, conservation, and utilization of tree peony resources.
Microbial Diversity of Marula Wine during Spontaneous Fermentation
Authors: Maluleke Evelyn , Lekganyane Maleho Annastasia , Moganedi Kgabo L. Maureen
Published: September 2023

Marula wine is produced from ripe fruits of the Sclerocarya birrea subspecies caffra tree through spontaneous fermentation. A few culture-based studies have shown that the fermentation is largely driven by yeasts, although, in the early stages, some lactic acid bacteria (LAB) and acetic acid bacteria may be detected. Some of the microbes may produce undesirable metabolites that lead to the spoilage and short shelf life of the wine. However, there is generally limited information on the microbial composition and its contribution to the chemical characteristics of the resultant marula wine. The aim of this study was to characterise the microbial population of marula wine from different localities in the Limpopo province, South Africa. MALDI-TOF and amplicon sequencing technique were used to identify microbial strains and to determine their diversity and changes in the different stages of fermentation. The phylogenetic relationships of LAB and S. cerevisiae were analysed using multilocus sequence typing. Bacterial species that were common in the different marula wines included Gluconobacter oxydans, Lactiplantibacillus plantarum, Levilactobacillus brevis, Lacitilactobacillus nagelii, Lentilactobacillus kefiri and Lentilactobacillus parabuchneri, and the yeasts were Hanseniaspora guiliermondii, Saccharomyces cerevisiae, Rhodotorula mucilaginosa and Pichia kudriavzevii. The MLST data indicated common microbiota from different marula wines with low intraspecific diversity, suggesting that the LAB and S. cerevisiae strains that are mainly responsible for the spontaneous fermentation of marula wine are similar irrespective of the geographical differences and production preferences.
Prevalence of Metabolic Syndrome Based on the Dietary Habits and Physical Activity of Korean Women Cancer Survivors
Authors: Zhou Peng , Kim Yonghwan , Lee Jiseol
Published: September 2023

Cancer is a major cause of death in Korea. Improving dietary habits and encouraging physical activity (PA) are important in managing the quality of life and health of patients. Cancer survivors (CS) often exhibit a higher incidence of metabolic syndrome (MetS) than non-cancer (NC) individuals. The purpose of this study was to analyze the prevalence of MetS according to dietary habits and PA in women who survived various cancers: stomach, colorectal, breast, cervical, lung, thyroid, and others. The participants (n = 12,676; NC: 11,673, CS: 1003) were analyzed cross-sectionally over a 6-year period. Caloric intake, eating-out frequency, breakfast frequency, dietary supplements, dietary therapy, nutritional education, participation in aerobic activity, strength training frequency, and sedentary lifestyle were evaluated. The prevalence of MetS was 1.22 (95% confidence interval (CI), 1.07–1.39) times higher in CS than in NC, exhibiting a 1.77-fold (95%CI, 1.14–2.74) increase in colorectal cancer, 1.72-fold (95%CI, 1.29–2.30) in cervical cancer, and 3.07-fold (95%CI, 1.14–5.31) in lung cancer. A higher-than-recommended caloric intake and frequent eating out increased MetS 1.43-fold (95%CI, 1.09–1.79) and 1.11-fold (95%CI, 1.01–1.64), respectively, in NC, and 1.31-fold (95%CI, 1.03–1.75) and 2.65-fold (95%CI, 2.29–3.07), respectively, in CS. Aerobic activity below the recommended level resulted in a 1.37-fold (95%CI, 1.13–1.71) and 1.36-fold (95%CI, 1.10–1.87) increase in NC and CS, respectively, whereas muscle strength increased 1.36-fold (95%CI, 1.08–1.70) and 1.49-fold (95%CI, 1.07–2.57), respectively, at below recommended levels. MetS was more prevalent in CS than in NC; high caloric intake, frequent eating out, low PA, and more sedentary time increased the risk of MetS.
Influence of Benincasa hispida Peel Extracts on Antioxidant and Anti-Aging Activities, including Molecular Docking Simulation
Authors: Phumat Pimpak , Chaichit Siripat , Potprommanee Siriporn , Preedalikit Weeraya , Sainakham Mathukorn , Poomanee Worrapan , Chaiyana Wantida , Kiattisin Kanokwan
Published: September 2023

Benincasa hispida peel, a type of postconsumer waste, is considered a source of beneficial phytochemicals. Therefore, it was subjected to investigation for biological activities in this study. B. hispida peel was extracted using 95% v/v, 50% v/v ethanol and water. The obtained extracts were B95, B50 and BW. B95 had a high flavonoid content (212.88 ± 4.73 mg QE/g extract) and phenolic content (131.52 ± 0.38 mg GAE/g extract) and possessed high antioxidant activities as confirmed by DPPH, ABTS and lipid peroxidation inhibition assays. Moreover, B95 showed inhibitory effects against collagenase and hyaluronidase with values of 41.68 ± 0.92% and 29.17 ± 0.66%, which related to anti-aging activities. Via the HPLC analysis, one of the potential compounds found in B95 was rutin. Molecular docking has provided an understanding of the molecular mechanisms underlying the interaction of extracts with collagenase and hyaluronidase. All extracts were not toxic to fibroblast cells and did not irritate the hen’s egg chorioallantoic membrane, which indicated its safe use. In conclusion, B. hispida peel extracts are promising potential candidates for further use as antioxidant and anti-aging agents in the food and cosmetic industries.
Bio-Resorption Control of Magnesium Alloy AZ31 Coated with High and Low Molecular Weight Polyethylene Oxide (PEO) Hydrogels
Authors: Aversa Raffaella , Perrotta Valeria , Wang Chao , Apicella Antonio
Published: September 2023

Magnesium AZ31 alloy has been chosen as bio-resorbable temporary prosthetic implants to investigate the degradation processes in a simulating body fluid (SBF) of the bare metal and the ones coated with low and high-molecular-weight PEO hydrogels. Hydrogel coatings are proposed to control the bioresorption rate of AZ31 alloy. The alloy was preliminary hydrothermally treated to form a magnesium hydroxide layer. 2 mm discs were used in bioresorption tests. Scanning electron microscopy was used to characterize the surface morphology of the hydrothermally treated and PEO-coated magnesium alloy surfaces. The variation of pH and the mass of Mg2+ ions present in the SBF corroding medium have been monitored for 15 days. Corrosion current densities (Icorr) and corrosion potentials (Ecorr) were evaluated from potentiodynamic polarisation tests on the samples exposed to the SBF solution. Kinetics of cumulative Mg ions mass released in the corroding solution have been evaluated regarding cations diffusion and mass transport parameters. The initial corrosion rates for the H- and L-Mw PEO-coated specimens were similar (0.95 ± 0.12 and 1.82 ± 0.52 mg/cm2day, respectively) and almost 4 to 5 times slower than that of the uncoated system (6.08 mg/cm2day). Results showed that the highly swollen PEO hydrogel coatings may extend into the bulk solution, protecting the coated metal and efficiently controlling the degradation rate of magnesium alloys. These findings focus more research effort on investigating such systems as tunable bioresorbable prosthetic materials providing idoneous environments to support cells and bone tissue repair.
Impact of an Educational Intervention for Healthy Eating in Older Adults: A Quasi-Experimental Study
Authors: Ortiz Segarra José , Freire Argudo Ulises , Delgado López Dayanara , Ortiz Mejía Stalin
Published: September 2023

The elderly population in Ecuador is increasing rapidly, with an increasing incidence of diet-related diseases. The elderly living in the community seek alternative and complementary methods to improve their diet and quality of life. This study aimed to investigate the impact of an educational intervention on knowledge related to healthy eating among older adults. This intervention is rooted in the principles of meaningful learning and incorporates culturally adapted materials. A quasi-experimental study design was employed using a pre-test–post-test control group. Study participants were a total of 109 elderly (intervention: n = 51, control: n = 58) people in Cuenca, Ecuador. The educational intervention based on Ausubel’s theory of significant learning and Vygotsky’s sociocultural theory was programmed to be carried out for one session per week, over 24 weeks, with a duration of 120 min per session. The measures were the general characteristics of the study participants and knowledge about necessary amounts, food sources and the consequences of deficits or excesses in the consumption of macro- and micronutrients. Data were collected from August 2018 to February 2019. Statistically significant differences were observed between the intervention group (IG) and the control group (CG) in terms of knowledge about healthy eating for older adults following the educational intervention. The outcomes of this study strongly suggest the efficacy of the program in improving knowledge related to healthy eating among older adults. Healthcare providers should prioritize food education based on meaningful learning, utilizing culturally adapted materials for the elderly individuals residing within the community.
MicroRNA2871b of Dongxiang Wild Rice (Oryza rufipogon Griff.) Negatively Regulates Cold and Salt Stress Tolerance in Transgenic Rice Plants
Authors: Yang Wanling , Chen Yong , Gao Rifang , Chen Yaling , Zhou Yi , Xie Jiankun , Zhang Fantao
Published: September 2023

Cold and salt stresses are major environmental factors that constrain rice production. Understanding their mechanisms is important to enhance cold and salt stress tolerance in rice. MicroRNAs (miRNAs) are a class of non-coding RNAs with only 21–24 nucleotides that are gene regulators in plants and animals. Previously, miR2871b expression was suppressed by cold stress in Dongxiang wild rice (DXWR, Oryza rufipogon Griff.). However, its biological functions in abiotic stress responses remain elusive. In the present study, miR2871b of DWXR was overexpressed to investigate its function under stress conditions. When miR2871b of DWXR was introduced into rice plants, the transgenic lines were more sensitive to cold and salt stresses, and their tolerance to cold and salt stress decreased. The increased expression of miR2871b in rice plants also increased the levels of reactive oxygen species (ROS) and malondialdehyde (MDA); however, it markedly decreased the activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) and the contents of proline (Pro) and soluble sugar (SS). These data suggested that miR2871b of DXWR has negative regulatory effects on cold and salt stress tolerance. Meanwhile, 412 differentially expressed genes (DEGs) were found in rice transgenic plants using transcriptome sequencing, among which 266 genes were up-regulated and 146 genes were down-regulated. Furthermore, the upstream cis-acting elements and downstream targets of miR2871b were predicted and analyzed, and several critical acting elements (ABRE and TC-rich repeats) and potential target genes (LOC_Os03g41200, LOC_Os07g47620, and LOC_Os04g30260) were obtained. Collectively, these results generated herein further elucidate the vital roles of miR2871b in regulating cold and salt responses of DXWR.
Formation of Ketimines from Aldimines in Schiff Base Condensation of Amino Acids and Imidazole-2-Carboxaldehydes: Tautomerization of Schiff Bases of Amino Acids Resulting in the Loss of Stereogenic Center
Authors: Brewer Greg , Brewer Cynthia , Butcher Raymond J. , Zavalij Peter
Published: September 2023

The Schiff base reaction of imidazole-2-carboxaldehydes with the anion of alanine, leucine and phenylalanine in the presence of nickel(II) ion gives the neutral NiL2 complexes. The Schiff base ligand, L, binds through an imidazole nitrogen, NIm, the amino acid nitrogen, NAA, and a carboxylate oxygen, O, atom. The two N2O ligands bind to the nickel(II) in a meridional fashion with the NIm and O of each ligand in trans positions. These ligands can exist as the anticipated aldimine, Im − CH = NAA − CH(R) − CO2−, or the ketimine, Im − CH2NAA = C(R) − CO2−, tautomer. Tautomerization of the initially formed aldimine Schiff base results in movement of the hydrogen atom of the alpha carbon of the amino acid to the aldehyde carbon, CAld, atom of the imidazole carboxaldehyde with resultant relocation of the imine double bond in the reverse direction. Ten structures of the structurally unprecedented ketimine tautomer, prepared from imidazole-2-carboxaldehydes and a pyrazole-3-carboxaldehyde, were presented. The structural data supported the formation of the ketimines in each case, while the aldimine tautomer was observed with imidazole-4-carboxaldehydes. A rationale of this can be explained on the basis of charge distribution in the likely intermediate in the tautomerization.
Composite Powders Synthesized from the Water Solutions of Sodium Silicate and Different Calcium Salts (Nitrate, Chloride, and Acetate)
Authors: Safronova Tatiana V. , Sterlikov Gleb S. , Kaimonov Maksim R. , Shatalova Tatiana B. , Filippov Yaroslav Y. , Toshev Otabek U. , Roslyakov Ilya V. , Kozlov Daniil A. , Tikhomirova Irina N. , Akhmedov Muslim R.
Published: September 2023

Composite powders were synthesized from the water solutions of sodium silicate and different calcium salts (nitrate, chloride, and acetate) at a Ca/Si molar ratio of 1.0. According to the XRD data, all the synthesized powders included hydrated calcium silicate Ca1,5SiO3,5·xH2O (Ca/Si molar ratio = 1.5) and calcium carbonate CaCO3 (Ca/Si molar ratio = ∞). The presence of H2SiO3 or SiO2·xH2O in the synthesized powders was assumed to be due to the difference between the Ca/Si molar ratio of 1.0 specified by the synthesis protocol and the molar ratio of the detected products. Reaction by-products (sodium nitrate NaNO3, sodium chloride NaCl, and sodium acetate NaCH3COO) were also found in the synthesized powders after filtration and drying. According to the XRD data phase composition of all powders after washing four times consisted of the quasi-amorphous phase and calcium carbonate in the form of calcite. Calcium carbonate in the form of aragonite was detected in powders synthesized from calcium chloride CaCl2 and calcium nitrate Ca(NO3)2 before and after washing. Synthesized powders containing reaction by-products and washed powders were used for the preparation of ceramics at 900, 1000, and 1100 °C. The phase composition of the ceramic samples prepared from the washed powders and powder containing NaCl after firing at 900 and 1000 °C consisted of β-wollastonite β-CaSiO3, and, after firing at 1100 °C, consisted of both β-wollastonite β-CaSiO3 and pseudo-wollastonite α-CaSiO3. The phase composition of the ceramic samples prepared from powders containing sodium nitrate NaNO3 and sodium acetate NaCH3COO after firing at 900, 1000, and 1100 °C consisted of calcium sodium silicates, i.e., Na2Ca2Si3O9 (combeite) and Na2Ca3Si2O8. Synthesized and washed composite powders can be used for the preparation of biocompatible materials, in the technology of construction materials, and as components of lunar soil simulants.
Towards Personalized Medicine for Chronic Liver Disease
Authors: Gao Jingwen , Xu Chunfang , Zhu Jinzhou
Published: September 2023

Chronic liver disease is a progressive deterioration of hepatic functions and a continuous process of inflammation, destruction, and regeneration of liver parenchyma, resulting in fibrosis and cirrhosis [...]
Achieving High Strength and Creep Resistance in Inconel 740H Superalloy through Wire-Arc Additive Manufacturing and Thermodynamic-Guided Heat Treatment
Authors: Sridar Soumya , Ladinos Pizano Luis Fernando , Klecka Michael A. , Xiong Wei
Published: September 2023

Inconel 740H superalloy is commonly used in advanced ultra-supercritical power plants since it possesses excellent strength and creep resistance. This study investigates the microstructure and mechanical properties of Inconel 740H superalloy fabricated using wire-arc additive manufacturing. The as-printed microstructure consisted of columnar γ grains with the Laves phase and (Nb, Ti)C carbides as secondary phases. The anisotropy in grain structure increased from the bottom to the top regions, while the hardness was highest in the middle portion of the build. To guide the post-heat treatment design, thermodynamic and kinetic simulations were employed to predict the temperature and time. Complete recrystallization with the Laves phase dissolution occurred throughout the build after homogenization at 1200 °C for 2 h. The peak hardness was achieved after aging at 760 °C for 12 h with the M23C6 carbides decorating the grain boundaries and γ’ precipitates in the grain interior. The yield strength (655 MPa) and ductility (29.5%) in the post-heat treated condition exceeded the design targets (620 MPa, 20%). Stress rupture tests at 750 °C showed that the high-temperature performance was at par with the wrought counterparts. The fracture mode after rupture was identified to be intergranular with the presence of grain boundary cavities along with grain boundary sliding.
Tailoring of the Structural, Optical, and Electrical Characteristics of Sol-Gel-Derived Magnesium-Zinc-Oxide Wide-Bandgap Semiconductor Thin Films via Gallium Doping
Authors: Tsay Chien-Yie , Chen Shih-Ting , Tsai Hsuan-Meng
Published: September 2023

The Ga-doped Mg0.2Zn0.8O (GMZO) transparent semiconductor thin films were prepared using the sol-gel and spin-coating deposition technique. Changes in the microstructural features, optical parameters, and electrical characteristics of sol-gel-synthesized Mg0.2Zn0.8O (MZO) thin films affected by the amount of Ga dopants (0–5 at%) were studied. The results of grazing incidence X-ray diffraction (GIXRD) examination showed that all as-prepared MZO-based thin films had a wurtzite-type structure and hexagonal phase, and the incorporation of Ga ions into the MZO nanocrystals refined the microstructure and reduced the average crystallite size and flatness of surface roughness. Each glass/oxide thin film sample exhibited a higher average transmittance than 91.5% and a lower average reflectance than 9.1% in the visible range spectrum. Experimental results revealed that the optical bandgap energy of the GMZO thin films was slightly higher than that of the MZO thin film; the Urbach energy became wider with increasing Ga doping level. It was found that the 2 at% and 3 at% Ga-doped MZO thin films had better electrical properties than the undoped and 5 at% Ga-doped MZO thin films.
A Buckling Analysis of Thermoelastic Micro/Nano-Beams Considering the Size-Dependent Effect and Non-Uniform Temperature Distribution
Authors: Ren Xin , Shi Shuanhu
Published: September 2023

Thermoelastic buckling of micro/nano-beams subjected to non-uniform temperature distribution is investigated in this paper. The mechanical governing equation is derived based on the surface effect and mechanical non-local effect. The non-local heat conduction model is used to predict temperature distribution in micro/nano-beams. Therefore, the obtained analytical solution can be used to analyze the influence of both the mechanical and thermal small scale effects on buckling of thermoelastic micro/nano-beams. In numerical simulations, a critical thickness is proposed to determine the influence region of both mechanical and thermal small scale effects. The influence of a small scale effect on buckling of micro/nano-beams must be considered if beam thickness is less than the critical thickness. In the influence region of a small scale effect, a surface effect has strong influence on the size-dependent buckling behavior, rather than mechanical and thermal non-local effects. Moreover, combined small scale effects, i.e., a surface effect and both mechanical and thermal non-local effects, lead to a larger critical load. Additionally, the influence of other key factors on buckling of the micro/nano-beams is studied in detail. This paper provides theoretical explanation to the buckling behaviors of micro/nano-beams under a non-uniform temperature distribution load.
Study on Boiling Heat Transfer Characteristics of Composite Porous Structure Fabricated by Selective Laser Melting
Authors: Liu Houli , Gu Zhonghao , Liang Jun
Published: September 2023

Surface porosity is an important means of enhancing boiling heat transfer. In this paper, two kinds of composite porous structures of surface micropore + square channel and framework micropore + square channel were prepared by selective laser melting technology using AlSi10Mg as the powder material. The effect of composites with different pore forms on boiling heat transfer was investigated in pool boiling experiments. It was found that controlling the thickness of the powder layer manufactured by selective laser melting can change the surface roughness of the sample, and the sandblasting treatment reduced the surface roughness of the samples. The average heat transfer coefficient of the rough surface composite porous structure sample was increased by 40% compared to the sandblasted sample. The micropores on the surface of the sample and inside the framework significantly enhanced the heat transfer coefficient of the composite porous structure. The presence of surface micropores increased the heat transfer area and the vaporization core density of the composite porous structure and exhibited excellent heat transfer coefficient improvement in the low heat flux region. The framework microporous composite porous structure can form effective gas–liquid diversion at high heat flux and obtain higher heat transfer performance. The large channel in the composite porous structure is the key control factor of the critical heat flux.
Milling Force Modeling Methods for Slot Milling Cutters
Authors: Wu Mingzhou , Zhang Guangpeng , Wang Tianle , Wang Rui
Published: September 2023

The slot milling cutter is primarily used for machining the tongue and groove of the steam turbine rotor, which is a critical operation in the manufacturing process of the steam turbine rotor. It is challenging to predict the milling force of a groove milling cutter due to variations in rake, rake angles and cutting speeds of the main cutting edge. Firstly, based on a limited amount of experimental data on turning, we have developed an equivalent turning force model that takes into account the impact of the rounded cutting edge radius, the tool’s tip radius and the feed rate on tool’s geometric angle. It provides a more accurate frontal angle for the identification method of the Johnson–Cook material constitutive equation. Secondly, the physical parameters, such as shear stress, shear strain and strain rate on the main shear plane, are calculated through the analysis of experimental data and application of the orthogonal cutting theory. Thirdly, the range of initial constitutive parameters of the material was determined through the split Hopkinson pressure bar (SHPB) test. The objective function was defined as the minimum error between the theoretical and experimental values. The optimal values of the Johnson–Cook constitutive equation parameters A, B, C, n and m are obtained through a global search using a genetic algorithm. Finally, the shear stress is determined by the governing equations of deformation, temperature and material. The axial force, torque and bending moment of each micro-segment are calculated and summed using the unit cutting force vector of each micro-segment. As a result, a milling force prediction model for slot milling cutters is established, and its validity is verified through experiments.
Metric Relations in the Fuzzy Right Triangle
Authors: Manríquez Ronald
Published: September 2023

The study of fuzzy geometry and its different components has grown in recent years, establishing the formal foundations for its development. This paper is devoted to addressing some metric relations in the fuzzy right triangle; in particular, a version of the Pythagorean theorem and geometric mean theorem are provided in analytical fuzzy geometry. The main results show, under certain conditions of the fuzzy vertices, a subset relation between the fuzzy distances associated with the fuzzy right triangle, which is very similar to the classical statements of the Pythagorean theorem and the geometric mean in Euclidean geometry.
Volatility Spillover Dynamics and Determinants between FinTech and Traditional Financial Industry: Evidence from China
Authors: Wang Ziyao , Xia Yufei , Fu Yating , Liu Ying
Published: September 2023

We explore the dynamics and determinants of volatility spillover between financial technology (FinTech) and the traditional financial industry (TFI). The total, directional, and net spillover indices are measured, and we further decompose volatility spillovers in a time–frequency framework. Economic fundamentals, risk contagion, and market attention are examined as potential determinants of volatility spillovers. We reveal that the total spillover index is time-varying and exhibits an inverse U-shape between 2017 and 2021. FinTech is a net volatility receiver in most cases, and exported volatility to the TFI during the COVID-19 pandemic. The long-term components are the main driving force of volatility spillovers based on the frequency domain decomposition. Meanwhile, the economic fundamental determinants are the main contributing factors of volatility spillovers, explaining over 60% of total spillover between FinTech and the TFI. The findings remain robust under different settings of forecasting horizons, lag lengths, and proxy of the risk contagion determinant.
Preconditioning Technique for an Image Deblurring Problem with the Total Fractional-Order Variation Model
Authors: Al-Mahdi Adel
Published: September 2023

Total fractional-order variation (TFOV) in image deblurring problems can reduce/remove the staircase problems observed with the image deblurring technique by using the standard total variation (TV) model. However, the discretization of the Euler–Lagrange equations associated with the TFOV model generates a saddle point system of equations where the coefficient matrix of this system is dense and ill conditioned (it has a huge condition number). The ill-conditioned property leads to slowing of the convergence of any iterative method, such as Krylov subspace methods. One treatment for the slowness property is to apply the preconditioning technique. In this paper, we propose a block triangular preconditioner because we know that using the exact triangular preconditioner leads to a preconditioned matrix with exactly two distinct eigenvalues. This means that we need at most two iterations to converge to the exact solution. However, we cannot use the exact preconditioner because the Shur complement of our system is of the form S=K*K+λLα which is a huge and dense matrix. The first matrix, K*K, comes from the blurred operator, while the second one is from the TFOV regularization model. To overcome this difficulty, we propose two preconditioners based on the circulant and standard TV matrices. In our algorithm, we use the flexible preconditioned GMRES method for the outer iterations, the preconditioned conjugate gradient (PCG) method for the inner iterations, and the fixed point iteration (FPI) method to handle the nonlinearity. Fast convergence was found in the numerical results by using the proposed preconditioners.
An Effective Framework for Predicting Performance of Solid-Solution Copper Alloys Using a Feature Engineering Technique in Machine Learning
Authors: Fan Tiehan , Hou Jianxin , Hu Jian
Published: September 2023

Utilized extensively in a myriad of industries, solid-solution copper alloys are prized for their superior electrical conductivity and mechanical properties. However, optimizing these often mutually exclusive properties poses a challenge, especially considering the complex interplay of alloy composition and processing techniques. To address this, we introduce a novel computational framework that employs advanced feature engineering within machine learning algorithms to accurately predict the alloy’s microhardness and electrical conductivity. Our methodology demonstrates a substantial enhancement over traditional data-driven models, achieving remarkable increases in R2 scores—from 0.939 to 0.971 for microhardness predictions and from −1.05 to 0.934 for electrical conductivity. Through machine learning, we also spotlight key determinants that significantly influence overall performance of solid-solution copper alloys, providing actionable insights for future alloy design and material optimization.
A Study on the Simulation and Experiment of Evaporative Condensers in an R744 Air Conditioning System
Authors: Dang Thanhtrung , Nguyen Hoangtuan
Published: September 2023

The heat transfer characteristics of evaporative condensers in an R744 air conditioning system were evaluated using the numerical and the experimental methods. Two configurations of condensers were studied: Case 1 with five layers of tubes and Case 2 with eight layers of tubes. In order to evaluate the heat transfer characteristics, the temperature field, the phase change, the pressure distribution, and thermodynamic parameters were considered. For Case 2, it indicated the capability of R744 condensation from the superheated status to the liquified status by analyzing the outlet temperature of the condenser changed from 28.7 °C to 30.3 °C with a change in condensation pressure from 72.6 bar to 68.5 bar. In this study, R744 mass flow rate increases from 14.34 kg/h to 46.08 kg/h, and the pressure drop also increases from 0.23 bar to 0.47 bar for the simulation and 0.4 bar to 0.5 bar for the experiment, respectively. The results indicate that the five-layer configuration causes a higher pressure drop and lower COP than those obtained from the eight-layer one (splitting into two sets for smaller pressure drop). Furthermore, the evaporative condensers using mini tubes that are flooded in the cooling water tank are suitable for the subcritical R744 air conditioning system. In addition, the results obtained from the experimental data are in good agreement with those obtained from the numerical results, with a deviation of less than 5%.
High-Efficiency Mono-Cyclopentadienyl Titanium and Rare-Earth Metal Catalysts for the Production of Syndiotactic Polystyrene
Authors: Wen Bo , Hu Hongfan , Kang Di , Sang Chenggong , Mao Guoliang , Xin Shixuan
Published: September 2023

Syndiotactic polystyrene (SPS) refers to a type of thermoplastic material with phenyl substituents that are alternately chirally attached on both sides of an aliphatic macromolecular main chain. Owing to its excellent physical and mechanical properties, as well as its chemical stability, high transparency, and electrical insulation characteristics, SPS is used in a wide variety of technical fields. SPS is commonly produced via the stereoselective transition metal-catalyzed coordination polymerization method mediated by stereospecific catalysts, which consists of anionic mono-cyclopentadienyl derivative η5-coordinated single active metal centers (referred to as “mono-Cp’-M”), with active center metals involving Group 4 transition metals (with an emphasis on titanium) and rare-earth (RE) metals of the periodic table. In this context, the use of mono-cyclopentadienyl titanocene (mono-Cp’Ti) catalysts and mono-cyclopentadienyl rare-earth metal (mono-Cp’RE) metallocene catalysts for the syndiospecific polymerization of styrene is discussed. The effects of the mono-cyclopentadienyl ligand structure, cationic active metal types, and cocatalysts on the activity and syndiospecificity of mono-Cp’ metallocene catalysts are briefly surveyed.
One-Pot Synthesis of Ultra-Small Pt Nanoparticles-Loaded Nitrogen-Doped Mesoporous Carbon Nanotube for Efficient Catalytic Reaction
Authors: Zhang Qian , Wu Minying , Fang Yuanyuan , Deng Chao , Shen Hsin-Hui , Tang Yi , Wang Yajun
Published: September 2023

In this study, Pt nanoparticles-loaded nitrogen-doped mesoporous carbon nanotube (Pt/NMCT) was successfully synthesized through a polydopamine-mediated “one-pot” co-deposition strategy. The Pt source was introduced during the co-deposition of polydopamine and silica on the surface of SiO2 nanowire (SiO2 NW), and Pt atoms were fixed in the skeleton by the chelation of polydopamine. Thus, in the subsequent calcination process in nitrogen atmosphere, the growth and agglomeration of Pt nanoparticles were effectively restricted, achieving the in situ loading of uniformly dispersed, ultra-small (~2 nm) Pt nanoparticles. The method is mild, convenient, and does not require additional surfactants, reducing agents, or stabilizers. At the same time, the use of the dual silica templates (SiO2 NW and the co-deposited silica nanoclusters) brought about a hierarchical pore structure with a high specific surface area (620 m2 g−1) and a large pore volume (1.46 cm3 g−1). The loading process of Pt was studied by analyzing the electron microscope and X-ray photoelectron spectroscopy of the intermediate products. The catalytic performance of Pt/NMCT was investigated in the reduction of 4-nitrophenol. The Pt/NMCT with a hierarchical pore structure had an apparent reaction rate constant of 0.184 min−1, significantly higher than that of the sample, without the removal of the silica templates to generate the hierarchical porosity (0.017 min−1). This work provides an outstanding contribution to the design of supported noble metal catalysts and also highlights the importance of the hierarchical pore structure for catalytic activity.
Controllable Synthesis and Growth Mechanism of Interlayer-Coupled Multilayer Graphene
Authors: Xue Xudong , Liu Mengya , Zhou Xiahong , Liu Shan , Wang Liping , Yu Gui
Published: September 2023

The potential applications of multilayer graphene in many fields, such as superconductivity and thermal conductivity, continue to emerge. However, there are still many problems in the growth mechanism of multilayer graphene. In this paper, a simple control strategy for the preparation of interlayer-coupled multilayer graphene on a liquid Cu substrate was developed. By adjusting the flow rate of a carrier gas in the CVD system, the effect for finely controlling the carbon source supply was achieved. Therefore, the carbon could diffuse from the edge of the single-layer graphene to underneath the layer of graphene and then interlayer-coupled multilayer graphene with different shapes were prepared. Through a variety of characterization methods, it was determined that the stacked mode of interlayer-coupled multilayer graphene conformed to AB-stacking structure. The small multilayer graphene domains stacked under single-layer graphene was first found, and the growth process and growth mechanism of interlayer-coupled multilayer graphene with winged and umbrella shapes were studied, respectively. This study reveals the growth mechanism of multilayer graphene grown by using a carbon source through edge diffusion, paving the way for the controllable preparation of multilayer graphene on a liquid Cu surface.
Toward an Etiology of Spaceflight Neuroplastic Syndrome: Evolutionary Science Leads to New Hypotheses and Program Priorities
Authors: Rappaport Margaret Boone , Corbally Christopher J.
Published: September 2023

Evolutionary theory is applied to recent neuroscientific findings on factors associated with risk-and-reward systems, and consequently, aspects of human decision making in spaceflight. Factors include enzymes aiding metabolic pathways of dopamine and serotonin; neurotrophic factors supporting neuronal functioning and plasticity; and genes associated with serotonin and dopamine systems. Not all factors are at risk in spaceflight. Some remain stable. It is hypothesized that neural deconditioning in spaceflight arises from faulty signals sent to the brain and gut in attempting to adapt phenotypically to a novel space environment. There is a mismatch between terrestrial selection pressures during human evolution and conditions of cosmic radiation, microgravity, and higher CO2, which together cause scattered results. A contrary question is broached: Given these findings, why are human sequelae not worse? Discussion of programmatic issues then focuses on methodologies to determine the suitability of civilians for spaceflight, an issue that grows more pressing while more varied populations prepare for spaceflight in LEO and on, and in orbit around the Moon.
Redesigning Recruitment and Engagement Strategies for Virtual Culinary Medicine and Medical Nutrition Interventions in a Randomized Trial of Patients with Uncontrolled Type 2 Diabetes
Authors: McGuire Molly , Chen Patricia , Smith-Morris Carolyn , Albin Jaclyn , Siler Milette , Lopez Miguel , Pruitt Sandi , Merrill Vincent , Bowen Michael
Published: September 2023

In-person culinary medicine (CM) can improve health behaviors, but its translation to virtual platforms and impact on diabetes outcomes are not well described. We designed a pragmatic trial comparing the effectiveness of virtual CM (eCM) to Medical Nutrition Therapy on diabetes outcomes among patients with uncontrolled diabetes within a safety-net healthcare system. All participants were provided cooking equipment and food from a food pantry. Due to low initial eCM participation, recruitment was paused, and eight semi-structured interviews were conducted to solicit feedback on study appeal, operations, and barriers to participation. Rapid thematic analysis was used to modify study operations. We found that participants were interested in the study and motivated by health concerns. While they valued food distribution and cooking equipment, they highlighted transportation barriers and conflicts with the pick-up time/location. Some eCM participants expressed discomfort with the virtual platform or preferred to observe rather than cook along. Study operations were modified by (1) moving supply pick-up to a familiar community clinic and diversifying food pick-up locations; (2) offering an in-person orientation to the program to increase comfort with the virtual platform; (3) emphasizing the credibility and relatability of the eCM instructor and encouraging participation of family members. This redesign led to the recruitment of 79 participants, of whom 75% attended at least one class. In conclusion, participant feedback informed pragmatic changes in study operations that increased engagement in this ongoing trial and may inform future eCM program design.
Association between Dietary Niacin Intake and Nonalcoholic Fatty Liver Disease: NHANES 2003–2018
Authors: Pan Jie , Hu Yuhua , Pang Nengzhi , Yang Lili
Published: September 2023

Evidence regarding the association between dietary niacin intake and nonalcoholic fatty liver disease (NAFLD) is limited. The objective of this study was to examine the association of dietary niacin intake with NAFLD. Subjects aged 20 years and older who participated in the National Health and Nutrition Examination Survey (NHANES) 2003–2018 were included in this study. Dietary niacin intake was assessed by two 24-h dietary recalls. NAFLD was defined using the United States fatty liver index (US-FLI). Weighted logistic regression models and restricted cubic splines were used to examine the association between dietary niacin and NAFLD. Of the 12,355 participants in this study, 4378 had NAFLD. There is no evident nonlinear relationship between dietary niacin intake and the presence of NAFLD in the restricted cubic spline regression (poverall < 0.001; pnon-linearity = 0.068). The multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for NAFLD were 0.84 (0.68–1.03), 0.80 (0.65–0.97), and 0.69 (0.55–0.85), respectively, when comparing the second, third, and fourth quartiles of niacin intake levels to the lowest quartile (ptrend = 0.001). Stratified analysis revealed that the effect of niacin intake on NAFLD varied in the group with or without hypertension (pinteraction = 0.033). In conclusion, our results indicate that higher dietary niacin intake may be associated with a lower likelihood of NAFLD.