bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization Research of Machining Parameters for Cutting GH4169 Based on Tool Vibration and Surface Roughness under High-Pressure Cooling
Authors: Zhang Yali , Wu Mingyang , Liu Keke , Zhang Jianyu
Published: December 2021

The nickel-based superalloy is widely used in aerospace. It is a typical difficult-to-cut material with poor plasticity. During the cutting process, the fluctuation of the cutting force caused by the change of cutting conditions can aggravate tool vibration, thereby reducing the surface quality of the machined workpiece. However, the emergence of high-pressure cooling technology provides technical support for overcoming the difficulty in superalloy processing. Therefore, it is of great significance to optimize the tool vibration and surface roughness of cutting GH4169 under high-pressure cooling. Taking GH4169 as the research object, the single-factor and orthogonal high-pressure cooling cutting experiments were conducted firstly in this paper. Then, the methods of the main effect diagram and response surface were applied to analyze the impact of cutting speed, feed rate, cutting depth, and cooling pressure on the three-way tool vibration. Next, MATLAB was adopted to draw the frequency spectrum of radial tool vibration at different cutting speeds, and the relationship between chip morphology, tool vibration, and workpiece surface roughness at different cutting speeds was discussed. Based on this, a mathematical model of radial tool cutting vibration and surface roughness related to the cutting amount and cooling pressure was established. Support vector machine (SVM) was applied to make predictions. Meanwhile, the non-dominated sorting genetic algorithm with an elitist strategy was adopted for multi-objective optimization, and the optimization results were verified through experiments. The results indicated that the feed rate and cutting depth had a great impact on the tool vibration and surface roughness. The established mathematical model was accurate and effective for optimizing the cutting parameters. These results are of great significance to improve the cutting stability and the quality of machined surface.
Effect of Deep Cryogenic Treatment on Corrosion Behavior of AISI H13 Die Steel
Authors: Shinde Tarang , Pruncu Catalin , Dhokey Narendra B. , Parau Anca C. , Vladescu Alina
Published: December 2021

AISI H13 die steel specimens were subjected to heating at 1020 °C followed by oil quenching and double tempering at 520 °C. Subsequently, these specimens were subjected to deep cryogenic treatment at −185 °C in liquid nitrogen environment for 16 h and then subjected to soft tempering at 100 °C once the specimens attained room temperature. Thereafter, the specimens were subjected to scanning electron microscopy (SEM) analysis and electron backscatter diffraction (EBSD) analysis. The electrochemical corrosion activity was investigated in 3.5% NaCl at 23 ± 0.5 °C by evaluating the evolution of open circuit potential over time and potentiodynamic curves, and electrochemical impedance spectroscopy study was also carried out. The heat-treated specimens exhibited better resistance to corrosion through more electropositive values of open circuit potential. This could be attributed to lower grain boundary area in heat-treated specimens as compared to 16 h cryogenically treated specimen as higher grain boundary areas behave as an anode in an electrochemical cell, thereby enhancing the rate of corrosion. According to electrochemical tests, the cryogenically treated surface is more resistant to corrosion, followed by heated alloy. However, both surface modification treatments improved the corrosion behavior of the untreated alloy.
Microstructure Evolution of FeNiCoCrAl1.3Mo0.5 High Entropy Alloy during Powder Preparation, Laser Powder Bed Fusion, and Microplasma Spraying
Authors: Semikolenov Anton , Kuznetsov Pavel , Bobkova Tatyana , Shalnova Svetlana , Klimova-Korsmik Olga , Klinkov Viktor , Kobykhno Ilya , Larionova Tatyana , Tolochko Oleg
Published: December 2021

In the present study, powder of FeCoCrNiMo0.5Al1.3 HEA was manufactured by gas atomization process, and then used for laser powder bed fusion (L-PBF) and microplasma spraying (MPS) technologies. The processes of phase composition and microstructure transformation during above mentioned processes and subsequent heat treatment were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and differential thermal analysis (DTA) methods. It was found that gas atomization leads to a formation of dendrites of body centered cubic (BCC) supersaturated solid solution with insignificant Mo-rich segregations on the peripheries of the dendrites. Annealing leads to an increase of element segregations till to decomposition of the BCC solid solution and formation of σ-phase and B2 phase. Microstructure and phase composition of L-PBF sample are very similar to those of the powder. The MPS coating has a little fraction of face centered cubic (FCC) phase because of Al oxidation during spraying and formation of regions depleted in Al, in which FCC structure becomes more stable. Maximum hardness (950 HV) is achieved in the powder and L-PBF samples after annealing at 600 °C. Elastic modulus of the L-PBF sample, determined by nanoindentation, is 165 GPa, that is 12% lower than that of the cast alloy (186 GPa).
Universal Model to Support the Quality Improvement of Industrial Products
Authors: Pacana Andrzej , Siwiec Dominika
Published: December 2021

Improving the quality of industrial products quality still is a challenge. Despite using quality control, there is a constant need to support this process to achieve an effective, precise, and complex analysis of product quality. The purpose was to develop a universal model that supports improving the quality of products via the consistent and repetitive determination of the causes of product incompatibilities and actions leading to their elimination; the model can be integrated with any quality control of the product. The model verification was carried out for the incompatibility of the mechanical seal in alloy 410, in which the porosity cluster was identified by the fluorescence method (FPI). The purpose of the analysis was created by the SMART(-ER) method. Then, a team of experts was selected from which the brainstorming (BM) was realized. After the BM method, the source of incompatibility and initial causes were identified. Then, the Ishikawa diagram (according to rule 5M + E) was developed to group the initial causes. Next, during the BM method, the main causes were selected. In the last stage, the 5Why method was used to determine improvement actions, i.e., adjust clotting parameters, introduce the obligation to undergo periodic training, and set aside a separate place for storing the electrodes. Originality is the combination of selected quality management tools in a coherent model, the main aim of which is to identify the main causes of incompatibility and improvement actions. Additionally, this model is universal and has applications with analyzing any product and the causes of its incompatibility, and it can be integrated with any product quality control. Therefore, the model can be useful for improving the quality of products in any enterprise.
Predictive Analytical Modeling of Thermo-Mechanical Effects in Orthogonal Machining
Authors: Mohamed-Amine Alliche , Mohamed Djennane , Abdelhakim Djebara , Songmene Victor
Published: December 2021

Factor relationships in a machining system do not work in pairs. Varying the cutting parameters, materials machined, or volumes produced will influence many machining characteristics. For this reason, we are attempting to better understand the effect of the Johnson-Cook (J-C) law of behavior on cutting temperature prediction. Thus, the objective of the present study is to investigate, experimentally and theoretically, the tool/material interactions and their effects on dust emission during orthogonal cutting. The proposed approach is built on three steps. First, we established an experimental design to analyze, experimentally, the cutting conditions effects on the cutting temperature under dry condition. The empirical model which is based on the response surface methodology was used to generate a large amount of data depending on the machining conditions. Through this step, we were able to analyze the sensitivity of the cutting temperature to different cutting parameters. It was found that cutting speed, tool tip radius, rake angle, and the interaction between the cutting speed and the rake angle explain more than 84.66% of the cutting temperature variation. The cutting temperature will be considered as a reference to validate the analytical model. Hence, a temperature prediction model is important as a second step. The modeling of orthogonal machining using the J-C plasticity model showed a good correlation between the predicted cutting temperature and that obtained by the proposed empirical model. The calculated deviations for the different cutting conditions tested are relatively acceptable (with a less than 10% error). Finally, the established analytical model was then applied to the machining processes in order to optimize the cutting parameters and, at the same time, minimize the generated dust. The evaluation of the dust generation revealed that the dust emission is closely related to the variation of the cutting temperature. We also noticed that the dust generation can indicate different phenomena of fine and ultrafine particles generation during the cutting process, related to the heat source or temperature during orthogonal machining. Finally, the effective strategy to limit dust emissions at the source is to avoid the critical temperature zone. For this purpose, the two-sided values can be seen as combinations to limit dust emissions at the source.
Enhancement of Ceramics Based Red-Clay by Bulk and Nano Metal Oxides for Photon Shielding Features
Authors: Elsafi Mohamed , Dib Mirvat Fawzi , Mustafa Hoda Ezzelddin , Sayyed M. I. , Khandaker Mayeen Uddin , Alsubaie Abdullah , Almalki Abdulraheem S. A. , Abbas Mahmoud I. , El-Khatib Ahmed M.
Published: December 2021

We prepared red clays by introducing different percentages of PbO, Bi2O3, and CdO. In order to understand how the introduction of these oxides into red clay influences its attenuation ability, the mass attenuation coefficient of the clays was experimentally measured in a lab using an HPGe detector. The theoretical shielding capability of the material present was obtained using XCOM to verify the accuracy of the experimental results. We found that the experimental and theoretical values agree to a very high degree of precision. The effective atomic number (Zeff) of pure red clay, and red clay with the three metal oxides was determined. The pure red clay had the lowest Zeff of the tested samples, which means that introducing any of these three oxides into the clay will greatly enhance its Zeff, and consequently its attenuation capability. Additionally, the Zeff for red clay with 10 wt% CdO is lower than the Zeff of red clay with 10 wt% Bi2O3 and PbO. We also prepared red clay using 10 wt% CdO nanoparticles and compared its attenuation ability with the red clay prepared with 10 wt% PbO, Bi2O3, and CdO microparticles. We found that the MAC of the red clay with 10 wt% nano-CdO was higher than the MAC of the clay with microparticle samples. Accordingly, nanoparticles could be a useful way to enhance the shielding ability of current radiation shielding materials.
Zirconia vs. Titanium Dental Implants: Primary Stability In-Vitro Analysis
Authors: Arlucea Nerea , Brizuela-Velasco Aritza , Dieguez-Pereira Markel , Punset Miquel , Molmeneu Meritxell , Sánchez Lasheras Fernando , deLlanos-Lanchares Hector , Álvarez-Arenal Ángel
Published: December 2021

The present experimental trial uses two types of dental implants, one made of titanium (Ti6Al4V) and the other one of zirconia (ZrO2), but both of identical design, to compare their stability and micro-movements values under load. One of each type of implant (n = 42) was placed into 21 cow ribs, recording the insertion torque and the resonance frequency using a specific transducer. Subsequently, a prosthetic crown made of PMMA was screwed onto each of the implants in the sample. They were then subjected to a static compression load on the vestibular cusp of the crown. The resulting micromovements were measured. The zirconia implants obtained a higher mean of both IT and RFA when compared with those of titanium, with statistically significant differences in both cases (p = 0.0483 and p = 0.0296). However, the micromovement values when load was applied were very similar for both types, with the differences between them (p = 0.3867) not found to be statistically significant. The results show that zirconia implants have higher implant stability values than titanium implants. However, the fact that there are no differences in micromobility values implies that caution should be exercised when applying clinical protocols for zirconia based on RFA, which only has evidence for titanium.
Enhanced Hydrogen Generation Performance of Al-Rich Alloys by a Melting-Mechanical Crushing-Ball Milling Method
Authors: Zhu Lixiang , Zou Meishuai , Zhang Xiaodong , Zhang Lichen , Wang Xiaoxuan , Song Tinglu , Wang Shuo , Li Xiaodong
Published: December 2021

The main problem for the application of hydrogen generated via hydrolysis of metal alloys is the low hydrogen generation rate (HGR). In this paper, active Al alloys were prepared using a new coupled method-melting-mechanical crushing-mechanical ball milling method to enhance the HGR at room temperature. This method contains three steps, including the melting of Al, Ga, In, and Sn ingots with low melting alloy blocks and casting into plates, then crushing alloy plate into powders and ball milling with chloride salts such as NiCl2 and CoCl2 were added during the ball milling process. The microstructure and phase compositions of Al alloys and reaction products were investigated via X-ray diffraction and scanning electron microscopy with energy dispersed X-ray spectroscopy. The low-melting-point Ga-In -Sn (GIS) phases contain a large amount of Al can act as a transmission medium for Al, which improves the diffusion of Al to Al/H2O reaction sites. Finer GIS phases after ball milling can further enhance the diffusion of Al and thus enhance the activity of Al alloy. The hydrogen generation performance through hydrolysis of water with Al at room temperature was investigated. The results show that the H2 generation performance of the Al-low-melting point alloy composite powder is significantly higher than the results reported to date. The highest H2 generation rate and H2 conversion efficiency can reach 5337 mL·min−1·g−1 for the hydrolysis of water with 1 g active alloy.
Iron-Utilization System in Vibrio vulnificus M2799
Authors: Miyamoto Katsushiro , Kawano Hiroaki , Okai Naoko , Hiromoto Takeshi , Miyano Nao , Tomoo Koji , Tsuchiya Takahiro , Komano Jun , Tanabe Tomotaka , Funahashi Tatsuya , Tsujibo Hiroshi
Published: December 2021

Vibrio vulnificus is a Gram-negative pathogenic bacterium that causes serious infections in humans and requires iron for growth. A clinical isolate, V. vulnificus M2799, secretes a catecholate siderophore, vulnibactin, that captures ferric ions from the environment. In the ferric-utilization system in V. vulnificus M2799, an isochorismate synthase (ICS) and an outer membrane receptor, VuuA, are required under low-iron conditions, but alternative proteins FatB and VuuB can function as a periplasmic-binding protein and a ferric-chelate reductase, respectively. The vulnibactin-export system is assembled from TolCV1 and several RND proteins, including VV1_1681. In heme acquisition, HupA and HvtA serve as specific outer membrane receptors and HupB is a sole periplasmic-binding protein, unlike FatB in the ferric-vulnibactin utilization system. We propose that ferric-siderophore periplasmic-binding proteins and ferric-chelate reductases are potential targets for drug discovery in infectious diseases.
Contribution of Global and Regional Longitudinal Strain for Clinical Assessment of HFpEF in Coronary and Hypertensive Patients
Authors: Stoichescu-Hogea Gheorghe , Buleu Florina Nicoleta , Christodorescu Ruxandra , Sosdean Raluca , Tudor Anca , Ember Andreea , Brie Daniel Miron , Drăgan Simona
Published: December 2021

Background: Contribution of global and regional longitudinal strain (GLS) for clinical assessment of patients with heart failure with preserved ejection fraction (HFpEF) is not well established. We sought to evaluate subclinical left ventricular dysfunction secondary to coronary artery disease (CAD) in HFpEF patients compared with hypertensive patients and age-matched healthy subjects. Material and methods: This was a retrospective study that included 148 patients (group 1 = 62 patients with HFpEF, group 2 = 46 hypertensive patients, and group 3 = 40 age-matched control subjects). Peak systolic segmental, regional (basal, mid, and apical), and global longitudinal strain were assessed for each study group using two-dimensional speckle-tracking echocardiography (2D-STE). Results: GLS values presented statistically significant differences between the three groups (p < 0.001); markedly increased values (more negative) were observed in the control group (−20.2 ± 1.4%) compared with HTN group values (−18.4 ± 3.0%, p = 0.031) and with HFpEF group values (−17.6 ± 2.3%, p < 0.001). The correlation between GLS values and HTN stages was significant, direct, and average (Spearman coefficient rho = 0.423, p < 0.001). GLS had the greatest ability to detect patients with HFpEF when HFpEF + CAD + HTN diastolic dysfunction (n = 30) + CON diastolic dysfunction (n = 2) from HFpEF + CAD + HTN + CON was analyzed. (optimal GLS limit of −19.35%, area under curve = 0.833, p < 0.001). Conclusions: Global longitudinal strain can be used for clinical assessment in differentiating coronary and hypertensive patients at higher risk for development of systolic dysfunction.
Cervical Cancer and Human Papillomavirus Awareness among Women in Saudi Arabia
Authors: Akkour Khalid , Alghuson Lolowah , Benabdelkamel Hicham , Alhalal Hani , Alayed Nada , AlQarni Amal , Arafah Maria
Published: December 2021

Background and Objectives: Cervical cancer (CC) is the eighth most common cancer among Saudi women of all ages. With limited national data, we aimed to evaluate the public awareness of cervical cancer, CC risk factors, HPV infection, and HPV vaccines in different regions of Saudi Arabia. Materials and Methods: This was a survey-based cross-sectional study that encompassed 564 Saudi women over a period of a month. A self-administrated questionnaire was distributed through different social media platforms. Results: The collected data included sociodemographic variables and questions assessing awareness of CC, and the attitudes toward CC screening and human papillomavirus (HPV) vaccination. Most respondents were aware of CC (84.0%), although their primary source of information was the internet. However, only 45 females (8.0%) had a history of cervical screening. Furthermore, most females did not know that HPV was transmitted sexually (78.9%), or that it caused genital warts (81.7%) and CC (81.9%). Regarding the HPV vaccine, 100 females (17.7%) had heard about it, but only 11 (2.0%) took the vaccine, although more than half of the respondents (54.1%) were willing to take the vaccine after being informed about it. Conclusions: We noticed a remarkable lack of awareness among the respondents regarding HPV’s clinical implications; and the HPV vaccine, and its importance and availability. The main source of information for most of the Saudi women in this study was the internet, which may be an unreliable source, or provide misleading information that may delay screening or discourage vaccination. Thus, organized campaigns by the Ministry of Health or other health-advocating agencies, in addition to screening and vaccination programs, are strongly encouraged.
Comparison between Fluorimetry (Qubit) and Spectrophotometry (NanoDrop) in the Quantification of DNA and RNA Extracted from Frozen and FFPE Tissues from Lung Cancer Patients: A Real-World Use of Genomic Tests
Authors: Masago Katsuhiro , Fujita Shiro , Oya Yuko , Takahashi Yusuke , Matsushita Hirokazu , Sasaki Eiichi , Kuroda Hiroaki
Published: December 2021

Background and Objectives: Panel-based next-generation sequencing (NGS) has been carried out in daily clinical settings for the diagnosis and treatment guidance of patients with non-small cell lung cancer (NSCLC). The success of genomic tests including NGS depends in large part on preparing better-quality DNA or RNA; however, there are no established operating methods for preparing genomic DNA and RNA samples. Materials and Methods: We compared the following two quantitative methods, the QubitTM and NanoDropTM, using 585 surgical specimens, 278 biopsy specimens, and 82 cell block specimens of lung cancer that were used for genetic tests, including NGS. We analyzed the success rate of the genomic tests, including NGS, which were performed with DNA and RNA with concentrations that were outliers for the Qubit Fluorometer. Results: The absolute value for DNA concentrations had a tendency to be higher when measured with NanoDropTM regardless of the type of specimen; however, this was not the case for RNA. The success rate of DNA-based genomic tests using specimens with a concentration below the lower limit of QubitTM detection was as high as approximately 96%. At less than 60%, the success rate of RNA-based genomic tests, including RT-PCR, was not as satisfactory. The success rates of the AmpliSeqTM DNA panel sequencing and RNA panel sequencing were 77.8% and 91.5%, respectively. If at least one PCR amplification product could be obtained, then all RNA-based sequencing was performed successfully. Conclusions: The concentration measurements with NanoDropTM are reliable. The success rate of NGS with samples at concentrations below the limit of detection of QubitTM was relatively higher than expected, and it is worth performing PCR-based panel sequencing, especially in cases where re-biopsy cannot be performed.
Microvascular Complications, Peripheral Artery Disease and Mortality in Patients with Type 2 Diabetes Mellitus, in Two Counties of Southern Lithuania over 13 Years: Analysis Using a Cohort Database of the National Health Insurance
Authors: Piliponienė Laima , Veličkienė Džilda , Kregždytė Rima
Published: December 2021

Background and Objectives: People living with diabetes mellitus are at risk of developing many serious and life-threatening complications. The present study aimed to determine the occurrence of microvascular complications, peripheral artery disease, and mortality in patients with type 2 diabetes mellitus (T2DM), in 2 Lithuanian counties. Materials and Methods: The data on residents aged ≥ 18 years, who were diagnosed for the first time in 2004 with uncomplicated T2DM, were obtained from the National Health Insurance Fund database. The occurrence of T2DM microvascular complications, peripheral artery disease, and mortality during the period from 2004 to 2016 were assessed by gender and age groups (<65 and ≥65 years). Results: During the 13 years, 46.9% of the patients developed T2DM complications. More men than women developed at least 1 T2DM complication (50.8% vs. 44.8%, p = 0.035). The mean time for developing any T2DM complication was 9.2 years. The probability of occurrence of any complication was 0.07 in the second year and increased to 0.59 in the thirteenth year of living with diabetes. Within the 13 years, 38.2% of the patients died. More men (43.1%) than women (35.5%) died during the analysis period (p = 0.036). Mortality was higher among older patients (60.7%) than among younger patients (22.2%) (p < 0.001). Conclusions: The results of this study provide a comprehensive picture of microvascular complications, peripheral artery disease, and mortality among patients with T2DM of two Lithuanian counties. Information about the occurrence of T2DM complications and mortality will assist further studies in estimating the burden of T2DM and in performing economic evaluations of T2DM prevention and treatment in Lithuania.
Use of the Cover-Lifting Technique in Mandibular Cemento-Ossifying Fibroma Excision to Preserve the Inferior Alveolar Nerve
Authors: Qiu Juan-You , Huang Kuan-Min , Lin Nan-Chin
Published: December 2021

Cemento-ossifying fibroma (also known as ossifying fibroma or cementifying fibroma) is a benign osteogenic neoplasm. Pain and paresthesia are rarely associated with cemento-ossifying fibroma; thus, nerves must be preserved during excision. With the advent of computer-aided techniques, the use of virtual surgical planning and a customized template can improve the precision of resection and reconstruction, reduce operating time, and improve postoperative outcomes. In this report, we describe a case of cemento-ossifying fibroma in a female patient who underwent segmental mandibulectomy and reconstruction with an iliac bone graft. Additionally, we describe a simple and effective way to preserve the inferior alveolar nerve.
Topical Application of Galgeunhwanggeumhwangryeon-Tang Recovers Skin-Lipid Barrier and Ameliorates Inflammation via Filaggrin-Thymic Stromal Lymphopoietin-Interleukin 4 Pathway
Authors: Ahn Sang-Hyun , Shin Su , Do Yoonju , Jo Yunju , Ryu Dongryeol , Ha Ki-Tae , Kim Kibong
Published: December 2021

Background and objectives: The purpose of this study was to confirm the effect of Galgeunhwanggeumhwangryeon-tang (GGRT) on the skin barrier integrity and inflammation in an atopic dermatitis-like animal model. Materials and Methods: The model was established using lipid barrier elimination (LBE) in BALB/c mice. Ceramide 3B, a control drug, and GGRT were applied to the skin of LBE mice. Gross observation and histological examination were combined with measurement of skin score, trans-epidermal water loss, and pH. The expression of filaggrin, kallikrein-related peptidase 7 (KLK7), protease-activated receptor-2 (PAR-2), thymic stromal lymphopoietin (TSLP), and interleukin 4 (IL-4) was examined. Results: The effect of GGRT on atopic dermatitis was estimated in silico using two individual gene sets of human atopic dermatitis. In animal experiments, GGRT treatment reduced atopic dermatitis-like symptoms, as confirmed via gross and histological observations, skin score, pH change, and trans-epidermal water loss. The expression level of filaggrin increased in the skin of GGRT-treated mice compared to that in the LBE group. The expression levels of KLK7, PAR2, TSLP, and IL-4 were decreased in GGRT-treated mice skin compared to those in LBE mice. Conclusions: We demonstrated that GGRT restored the skin barrier and reduced inflammatory reactions in a murine model of atopic dermatitis.
A Stochastic Spatiotemporal Model of Rat Ventricular Myocyte Calcium Dynamics Demonstrated Necessary Features for Calcium Wave Propagation
Authors: Hoang-Trong Tuan Minh , Ullah Aman , Lederer William Jonathan , Jafri Mohsin Saleet
Published: December 2021

Calcium (Ca2+) plays a central role in the excitation and contraction of cardiac myocytes. Experiments have indicated that calcium release is stochastic and regulated locally suggesting the possibility of spatially heterogeneous calcium levels in the cells. This spatial heterogeneity might be important in mediating different signaling pathways. During more than 50 years of computational cell biology, the computational models have been advanced to incorporate more ionic currents, going from deterministic models to stochastic models. While periodic increases in cytoplasmic Ca2+ concentration drive cardiac contraction, aberrant Ca2+ release can underly cardiac arrhythmia. However, the study of the spatial role of calcium ions has been limited due to the computational expense of using a three-dimensional stochastic computational model. In this paper, we introduce a three-dimensional stochastic computational model for rat ventricular myocytes at the whole-cell level that incorporate detailed calcium dynamics, with (1) non-uniform release site placement, (2) non-uniform membrane ionic currents and membrane buffers, (3) stochastic calcium-leak dynamics and (4) non-junctional or rogue ryanodine receptors. The model simulates spark-induced spark activation and spark-induced Ca2+ wave initiation and propagation that occur under conditions of calcium overload at the closed-cell condition, but not when Ca2+ levels are normal. This is considered important since the presence of Ca2+ waves contribute to the activation of arrhythmogenic currents.
Novel Surrogates for Membrane Fouling and the Application of Support Vector Machine in Analyzing Fouling Mechanism
Authors: Meng Xianghao , Wang Fukuan , Meng Shujuan , Wang Rui , Mao Zhongyuan , Li Yue , Yu Meifeng , Wang Xuye , Zhao Qian , Yang Linyan
Published: December 2021

It is difficult to recognize specific fouling mechanisms due to the complexity of practical feed water, thus the current studies usually employ foulant surrogates to carry out research, such as alginate and xanthan gum. However, the representativeness of these surrogates is questionable. In this work, the classical surrogates (i.e., alginate and xanthan gum) were systematically studied, and results showed that they behaved differently during filtration. For the mixture of alginate and xanthan gum, both filtration behaviors and adsorption tests performed by quartz-crystal microbalance with dissipation monitoring (QCM-D) indicated that alginate plays a leading role in fouling development. Furthermore, by examining the filtration behaviors of extracellular polymeric substances (EPS) extracted from practical source water, it turns out that the gel layer formation is responsible for EPS fouling, and the properties of gel layer formed by EPS share more similarities with that formed from pectin instead of alginate. In addition, with the use of experimental data sets extracted from this study and our previous studies, a modeling method was established and tested by the support vector machine (SVM) to predict complex filtration behaviors. Results showed that the small differences of fouling mechanisms lying between alginate and pectin cannot be recognized by Hermia’s models, and SVM can show a discrimination as high as 76.92%. As such, SVM may be a powerful tool to predict complex filtration behaviors.
The Effect of Tin Content on the Strength of a Carbon Fiber/Al-Sn-Matrix Composite Wire
Authors: Galyshev Sergei , Orlov Valery , Atanov Bulat , Kolyvanov Evgeniy , Averichev Oleg , Akopdzhanyan Tigran
Published: December 2021

The effect of tin content in an Al-Sn alloy in the range from 0 to 100 at.% on its mechanical properties was studied. An increase in the tin content leads to a monotonic decrease in the microhardness and conditional yield stress of the Al-Sn alloy from 305 to 63 MPa and from 32 to 5 MPa, respectively. In addition, Young’s modulus and the shear modulus of the Al-Sn alloy decreases from 65 to 52 GPa and from 24 to 20 GPa, respectively. The effect of tin content in the Al-Sn matrix alloy in the range from 0 to 50 at.% on the strength of a carbon fiber/aluminum-tin-matrix (CF/Al-Sn) composite wire subject to three-point bending was also investigated. Increasing tin content up to 50 at.% leads to a linear increase in the composite wire strength from 1450 to 2365 MPa, which is due to an increase in the effective fiber strength from 65 to 89 at.%. The addition of tin up to 50 at.% to the matrix alloy leads to the formation of weak boundaries between the matrix and the fiber. An increase in the composite wire strength is accompanied by an increase in the average length of the fibers pulled out at the fracture surface. A qualitative model of the relationship between the above parameters is proposed.
Experimental Study on Factors Influencing the Strength Distribution of In Situ Cemented Tailings Backfill
Authors: Peng Xiaopeng , Guo Lijie , Liu Guangsheng , Yang Xiaocong , Chen Xinzheng
Published: December 2021

Previous studies have found that the strength of in situ cemented tailings backfill usually presents an S-shaped distribution, which decreases first, then increases, and decreases thereafter along the direction of slurry flow. In this study, to explore the factors determining the distribution, a similar model test of cemented tailings backfill was carried out. The distribution law of grain size composition and the cement content of backfill materials along the flow direction were experimentally studied, and the comprehensive factor influencing the strength distribution was analyzed. The results show that, firstly, near the feeding point, there are more coarse particles, whereas the content of fine particles is higher farther away. The measured maximum median particle size can be more than three times the minimum value. Secondly, the cement content increases gradually along the flow direction and reaches the peak at the end of the model, which can be more than twice the minimum value, indicating that the degree of segregation is significant. Thirdly, the strength distribution of cemented backfills is comprehensively determined by both the particle size distribution (PSD) and the cement content. The maximum value appears neither at the point with peak median particle size, nor at the point with the highest cement content. Lastly, there is a strong linear correlation between the strength of cemented backfills and the strength factor (SF), which is defined as the product of the uniformity coefficient and cement content of filling materials, indicating that the SF can be used to quantitatively reflect the comprehensive effects of PSD and cement content on the strength. As SF is a comprehensive quantitative index reflecting the distribution of strength, it will be further studied in later research to acquire more experimental results of the relationship between sample strength and SF, which will be meaningful for the quality evaluation of in situ cemented backfills, and the optimization of backfill system.
Surface Investigation of Ni81Fe19 Thin Film: Using ARXPS for Thickness Estimation of Oxidation Layers
Authors: He Zongsheng , Li Ziyu , Jiang Xiaona , Wu Chuanjian , Liu Yu , Song Xinglian , Yu Zhong , Wang Yifan , Lan Zhongwen , Sun Ke
Published: December 2021

This work demonstrates the dependence between magnetic properties and the thickness of NiFe thin films. More importantly, a quantitative study of the surface composition of NiFe thin film exposed to atmospheric conditions has been carried out employing angle-resolved X-ray photoelectron spectroscopy (ARXPS). In this study, we fabricated Ni81Fe19 (NiFe) thin films on Si (100) substrate using electron beam evaporation and investigated their surface morphologies, magnetic properties, and the thickness of the surface oxide layer. The coexistence of metallic and oxidized species on the surface are suggested by the depth profile of ARXPS spectra. The thickness of the oxidized species, including NiO, Ni(OH)2, Fe2O3, and Fe3O4, are also estimated based on the ARXPS results. This work provides an effective approach to clarify the surface composition, as well as the thickness of the oxide layer of the thin films.
Reduced Fatty Acid Use from CD36 Deficiency Deteriorates Streptozotocin-Induced Diabetic Cardiomyopathy in Mice
Authors: Umbarawan Yogi , Kawakami Ryo , Syamsunarno Mas , Obinata Hideru , Yamaguchi Aiko , Hanaoka Hirofumi , Hishiki Takako , Hayakawa Noriyo , Koitabashi Norimichi , Sunaga Hiroaki , Matsui Hiroki , Kurabayashi Masahiko , Iso Tatsuya
Published: December 2021

Cardiac dysfunction is induced by multifactorial mechanisms in diabetes. Deranged fatty acid (FA) utilization, known as lipotoxicity, has long been postulated as one of the upstream events in the development of diabetic cardiomyopathy. CD36, a transmembrane glycoprotein, plays a major role in FA uptake in the heart. CD36 knockout (CD36KO) hearts exhibit reduced rates of FA transport with marked enhancement of glucose use. In this study, we explore whether reduced FA use by CD36 ablation suppresses the development of streptozotocin (STZ)-induced diabetic cardiomyopathy. We found that cardiac contractile dysfunction had deteriorated 16 weeks after STZ treatment in CD36KO mice. Although accelerated glucose uptake was not reduced in CD36KO-STZ hearts, the total energy supply, estimated by the pool size in the TCA cycle, was significantly reduced. The isotopomer analysis with 13C6-glucose revealed that accelerated glycolysis, estimated by enrichment of 13C2-citrate and 13C2-malate, was markedly suppressed in CD36KO-STZ hearts. Levels of ceramides, which are cardiotoxic lipids, were not elevated in CD36KO-STZ hearts compared to wild-type-STZ ones. Furthermore, increased energy demand by transverse aortic constriction resulted in synergistic exacerbation of contractile dysfunction in CD36KO-STZ mice. These findings suggest that CD36KO-STZ hearts are energetically compromised by reduced FA use and suppressed glycolysis; therefore, the limitation of FA utilization is detrimental to cardiac energetics in this model of diabetic cardiomyopathy.
Metabolic Fluctuations in the Human Stool Obtained from Blastocystis Carriers and Non-Carriers
Authors: Betts Emma L. , Newton Jamie M. , Thompson Gary S. , Sarzhanov Fakhriddin , Jinatham Vasana , Kim Moon-Ju , Popluechai Siam , Dogruman-Al Funda , Won Eun-Jeong , Gentekaki Eleni , Tsaousis Anastasios D.
Published: December 2021

Blastocystis is an obligate anaerobic microbial eukaryote that frequently inhabits the gastrointestinal tract. Despite this prevalence, very little is known about the extent of its genetic diversity, pathogenicity, and interaction with the rest of the microbiome and its host. Although the organism is morphologically static, it has no less than 28 genetically distinct subtypes (STs). Reports on the pathogenicity of Blastocystis are conflicting. The association between Blastocystis and intestinal bacterial communities is being increasingly explored. Nonetheless, similar investigations extending to the metabolome are non-existent.Using established NMR metabolomics protocols in 149 faecal samples from individuals from South Korea (n = 38), Thailand (n = 44) and Turkey (n = 69), we have provided a snapshot of the core metabolic compounds present in human stools with (B+) and without (B−) Blastocystis. Samples included hosts with gastrointestinal symptoms and asymptomatics. A total of nine, 62 and 98 significant metabolites were associated with Blastocystis carriage in the South Korean, Thai and Turkish sample sets respectively, with a number of metabolites increased in colonised groups. The metabolic profiles of B+ and B− samples from all countries were distinct and grouped separately in the partial least squares-discriminant analysis (PLS-DA). Typical inflammation-related metabolites negatively associated with Blastocystis positive samples. This data will assist in directing future studies underlying the involvement of Blastocystis in physiological processes of both the gut microbiome and the host. Future studies using metabolome and microbiome data along with host physiology and immune responses information will contribute significantly towards elucidating the role of Blastocystis in health and disease.
Supervised Statistical Learning Prediction of Soybean Varieties and Cultivation Sites Using Rapid UPLC-MS Separation, Method Validation, and Targeted Metabolomic Analysis of 31 Phenolic Compounds in the Leaves
Authors: Rha Chan-Su , Jang Eun Kyu , Hong Yong Deog , Park Won Seok
Published: December 2021

Soybean (Glycine max; SB) leaf (SL) is an abundant non-conventional edible resource that possesses value-adding bioactive compounds. We predicted the attributes of SB based on the metabolomes of an SL using targeted metabolomics. The SB was planted in two cities, and SLs were regularly obtained from the SB plant. Nine flavonol glycosides were purified from SLs, and a validated simultaneous quantification method was used to establish rapid separation by ultrahigh-performance liquid chromatography-mass detection. Changes in 31 targeted compounds were monitored, and the compounds were discriminated by various supervised machine learning (ML) models. Isoflavones, quercetin derivatives, and flavonol derivatives were discriminators for cultivation days, varieties, and cultivation sites, respectively, using the combined criteria of supervised ML models. The neural model exhibited higher prediction power of the factors with high fitness and low misclassification rates while other models showed lower. We propose that a set of phytochemicals of SL is a useful predictor for discriminating characteristics of edible plants.
Association of Neonatal Jaundice with Gut Dysbiosis Characterized by Decreased Bifidobacteriales
Authors: Akagawa Shohei , Akagawa Yuko , Yamanouchi Sohsaku , Teramoto Yoshiki , Yasuda Masahiro , Fujishiro Sadayuki , Kino Jiro , Hirabayashi Masato , Mine Kenji , Kimata Takahisa , Hashiyada Masaki , Akane Atsushi , Tsuji Shoji , Kaneko Kazunari
Published: December 2021

Neonatal jaundice, caused by excess serum bilirubin levels, is a common condition in neonates. Imbalance in the gut microbiota is believed to play a role in the development of neonatal jaundice. Thus, we aimed to reveal the gut microbiota characteristics in neonates with jaundice. 16S rRNA gene sequencing was performed on stool samples collected on day 4 from 26 neonates with jaundice (serum total bilirubin > 15.0 mg/dL) and 17 neonates without jaundice (total serum bilirubin < 10.0 mg/dL). All neonates were born full term, with normal weight, by vaginal delivery, and were breastfed. Neonates who were administered antibiotics, had serum direct bilirubin levels above 1 mg/dL, or had conditions possibly leading to hemolytic anemia were excluded. The median serum bilirubin was 16.0 mg/dL (interquartile range: 15.5–16.8) and 7.4 mg/dL (interquartile range: 6.8–8.3) for the jaundice and non-jaundice groups, respectively. There was no difference in the alpha diversity indices. Meanwhile, in the jaundice group, linear discriminant analysis effect size revealed that Bifidobacteriales were decreased at the order level, while Enterococcaceae were increased and Bifidobacteriaceae were decreased at the family level. Bifidobacteriaceae may act preventatively because of their suppressive effect on beta-glucuronidase, leading to accelerated deconjugation of conjugated bilirubin in the intestine. In summary, neonates with jaundice had dysbiosis characterized by a decreased abundance of Bifidobacteriales.
Special Issue on Networks-on-Chip Again on the Rise: From Emerging Applications to Emerging Technologies
Authors: Bertozzi Davide , Abellán José L. , Nikdast Mahdi
Published: December 2021

Twenty years after the advent of interconnection networks to tackle the on-chip communication bottleneck [...]
A Cerebral Organoid Connectivity Apparatus to Model Neuronal Tract Circuitry
Authors: Robles Denise , Boreland Andrew , Pang Zhiping , Zahn Jeffrey
Published: December 2021

Mental disorders have high prevalence, but the efficacy of existing therapeutics is limited, in part, because the pathogenic mechanisms remain enigmatic. Current models of neural circuitry include animal models and post-mortem brain tissue, which have allowed enormous progress in understanding the pathophysiology of mental disorders. However, these models limit the ability to assess the functional alterations in short-range and long-range network connectivity between brain regions that are implicated in many mental disorders, e.g., schizophrenia and autism spectrum disorders. This work addresses these limitations by developing an in vitro model of the human brain that models the in vivo cerebral tract environment. In this study, microfabrication and stem cell differentiation techniques were combined to develop an in vitro cerebral tract model that anchors human induced pluripotent stem cell-derived cerebral organoids (COs) and provides a scaffold to promote the formation of a functional connecting neuronal tract. Two designs of a Cerebral Organoid Connectivity Apparatus (COCA) were fabricated using SU-8 photoresist. The first design contains a series of spikes which anchor the CO to the COCA (spiked design), whereas the second design contains flat supporting structures with open holes in a grid pattern to anchor the organoids (grid design); both designs allow effective media exchange. Morphological and functional analyses reveal the expression of key neuronal markers as well as functional activity and signal propagation along cerebral tracts connecting CO pairs. The reported in vitro models enable the investigation of critical neural circuitry involved in neurodevelopmental processes and has the potential to help devise personalized and targeted therapeutic strategies.
Index Modulation Embedded in Type I Waveguide Written by Femtosecond Laser in Fused Silica
Authors: Lv Jing , Stoian Razvan , Cheng Guanghua , Wang Kedian
Published: December 2021

Slit-shaped laser beams focused in bulk optical materials can realize embedded waveguides with circular cross sections consisting of positive index change type I traces. In these kinds of waveguide traces, a peculiar periodical refractive index modulation was observed in type I waveguides with two different femtosecond lasers. The direction of refractive index modulation can be controlled with the slit configuration, and its period can be controlled by mechanical perturbation of the stages and the scanning speed. We argue that platform perturbation and dynamical thermal transport processes during the scan are generating factors in the appearance of this modulation. The embedded microstructures in waveguides can provide spectrum modulation, which may have potential applications in optical sensing, filtering, and phase control.
Metasurface Photodetectors
Authors: Li Jinzhao , Li Junyu , Zhou Shudao , Yi Fei
Published: December 2021

Photodetectors are the essential building blocks of a wide range of optical systems. Typical photodetectors only convert the intensity of light electrical output signals, leaving other electromagnetic parameters, such as the frequencies, phases, and polarization states unresolved. Metasurfaces are arrays of subwavelength structures that can manipulate the amplitude, phase, frequency, and polarization state of light. When combined with photodetectors, metasurfaces can enhance the light-matter interaction at the pixel level and also enable the detector pixels to resolve more electromagnetic parameters. In this paper, we review recent research efforts in merging metasurfaces with photodetectors towards improved detection performances and advanced detection schemes. The impacts of merging metasurfaces with photodetectors, on the architecture of optical systems, and potential applications are also discussed.
Recent Advancements in Metallurgical Processing of Marine Minerals
Authors: Ochromowicz Katarzyna , Aasly Kurt , Kowalczuk Przemyslaw
Published: December 2021

Polymetallic manganese nodules (PMN), cobalt-rich manganese crusts (CRC) and seafloor massive sulfides (SMS) have been identified as important resources of economically valuable metals and critical raw materials. The currently proposed mineral processing operations are based on metallurgical approaches applied for land resources. Thus far, significant endeavors have been carried out to describe the extraction of metals from PMN; however, to the best of the authors’ knowledge, it lacks a thorough review on recent developments in processing of CRC and SMS. This paper begins with an overview of each marine mineral. It is followed by a systematic review of common methods used for extraction of metals from marine mineral deposits. In this review, we update the information published so far in peer-reviewed and technical literature, and briefly provide the future perspectives for processing of marine mineral deposits.