bluuebunny/crossref_metadata_2025 huggingface dataset:
An Empirical Study on the Impact of E-Commerce Live Features on Consumers’ Purchase Intention: From the Perspective of Flow Experience and Social Presence
Authors: Wang Haijian , Ding Jianyi , Akram Umair , Yue Xialei , Chen Yitao
Published: August 2021

The COVID-19 pandemic and the continuous advancement of live e-commerce technology pushed the swift growth of live e-commerce in China. Based on the S–O–R theoretical framework, this study investigates the impact of live broadcast characteristics on consumers’ social presence and flow experience, along with their impact on the consumers’ consumption intention in live e-commerce scenarios through questionnaires. Using structural equation modeling, data processing and involvement were introduced as regulating variables. Host charm, interaction, and trust in the host exerted a significant positive impact on social presence. In addition, host charm and trust in host significantly affected flow experience, and social presence significantly affected flow experience. Both social presence and flow experience significantly affected consumption intention, while involvement affected all paths to some extent. Overall, this study illustrates the significance of host in live e-commerce, and consumers with low involvement should be the focus of attention in live e-commerce.
Microstructural, Mechanical and Physical Assessment of Portland Cement Concrete Pavement Modified by Sodium Acetate under Various Curing Conditions
Authors: Al-Kheetan Mazen J. , Ghaffar Seyed Hamidreza , Awad Said , Chougan Mehdi , Byzyka Juliana , Rahman Mujib M.
Published: August 2021

Portland Cement Concrete (PCC) pavement was studied with incorporation of an environmentally friendly eco-additive, sodium acetate (C2H3NaO2). This additive was added to PCC pavement in three different percentages of 2%, 4% and 6% of binder weight. For a comprehensive elucidation of the eco-additive incorporation on the performance of PCC pavement, casted samples were cured in three different environments, namely: water, outdoors and pond water. Water absorption tests, flexural and compressive strength tests after 7 and 28 days of curing were conducted and results compared with the control samples without any addition of sodium acetate. Results demonstrated a significant improvement in the impermeability, compressive strength and flexural strength of PCC pavement when sodium acetate concrete is cured in a water bath and outdoors. However, no/little improvement in the impermeability, compressive strength and flexural strength was observed in sodium acetate samples that were cured in pond water. Microstructural analysis of treated samples by using scanning electron microscopy (SEM) illustrated the strengthening effect that sodium acetate provides to the pore structure of concrete pavement.
Growth of Yellowtail (Seriola quinqueradiata) Fed on a Diet Including Partially or Completely Defatted Black Soldier Fly (Hermetia illucens) Larvae Meal
Authors: Ido Atsushi , Ali Muhammad-Fariz-Zahir , Takahashi Takayuki , Miura Chiemi , Miura Takeshi
Published: August 2021

Against a background of increased demand for fish meal (FM), black soldier fly larva is a promising alternative feed source for sustainable aquaculture. Yellowtail, the most popular farmed fish in Japan, is a carnivorous fish; therefore, it requires a high proportion of FM in its diet. This study represents the first example of yellowtail fed on a diet including insect meal as a replacement for FM. Partially defatted black soldier fly meal (PDBM) comprised 49.0% crude protein and 23.2% crude fat, while completely defatted black soldier fly meal (CDBM) contained less than 10% crude fat, as the same level as FM was achieved with defatting PDBM using hexane. In feeding trials, growth of the fish was reduced in accordance with PDBM content: 10%, 20%, and 30% in their diet. Although a diet including 8% CDBM (with the same protein composition as 10% PDBM) also resulted in decreased fish growth, growth with a diet including 16% CDBM (with the same protein composition as 20% PDBM) was significantly higher than that of 20% PDBM, and equivalent to that of 10% PDBM. Therefore, even 10% of partially or completely black soldier fly larvae meal in diets inhibited growth in juvenile yellowtail, and we found that removal of the fat fraction could improve fish growth.
RSSI-Based MAC-Layer Spoofing Detection: Deep Learning Approach
Authors: Madani Pooria , Vlajic Natalija
Published: August 2021

In some wireless networks Received Signal Strength Indicator (RSSI) based device profiling may be the only viable approach to combating MAC-layer spoofing attacks, while in others it can be used as a valuable complement to the existing defenses. Unfortunately, the previous research works on the use of RSSI-based profiling as a means of detecting MAC-layer spoofing attacks are largely theoretical and thus fall short of providing insights and result that could be applied in the real world. Our work aims to fill this gap and examine the use of RSSI-based device profiling in dynamic real-world environments/networks with moving objects. The main contributions of our work and this paper are two-fold. First, we demonstrate that in dynamic real-world networks with moving objects, RSSI readings corresponding to one fixed transmitting node are neither stationary nor i.i.d., as generally has been assumed in the previous literature. This implies that in such networks, building an RSSI-based profile of a wireless device using a single statistical/ML model is likely to yield inaccurate results and, consequently, suboptimal detection performance against adversaries. Second, we propose a novel approach to MAC-layer spoofing detection based on RSSI profiling using multi-model Long Short-Term Memory (LSTM) autoencoder—a form of deep recurrent neural network. Through real-world experimentation we prove the performance superiority of this approach over some other solutions previously proposed in the literature. Furthermore, we demonstrate that a real-world defense system using our approach has a built-in ability to self-adjust (i.e., to deal with unpredictable changes in the environment) in an automated and adaptive manner.
Bioprinting and In Vitro Characterization of an Eggwhite-Based Cell-Laden Patch for Endothelialized Tissue Engineering Applications
Authors: Delkash Yasaman , Gouin Maxence , Rimbeault Tanguy , Mohabatpour Fatemeh , Papagerakis Petros , Maw Sean , Chen Xiongbiao
Published: August 2021

Three-dimensional (3D) bioprinting is an emerging fabrication technique to create 3D constructs with living cells. Notably, bioprinting bioinks are limited due to the mechanical weakness of natural biomaterials and the low bioactivity of synthetic peers. This paper presents the development of a natural bioink from chicken eggwhite and sodium alginate for bioprinting cell-laden patches to be used in endothelialized tissue engineering applications. Eggwhite was utilized for enhanced biological properties, while sodium alginate was used to improve bioink printability. The rheological properties of bioinks with varying amounts of sodium alginate were examined with the results illustrating that 2.0–3.0% (w/v) sodium alginate was suitable for printing patch constructs. The printed patches were then characterized mechanically and biologically, and the results showed that the printed patches exhibited elastic moduli close to that of natural heart tissue (20–27 kPa) and more than 94% of the vascular endothelial cells survived in the examination period of one week post 3D bioprinting. Our research also illustrated the printed patches appropriate water uptake ability (>1800%).
Inference of an Integrative, Executable Network for Rheumatoid Arthritis Combining Data-Driven Machine Learning Approaches and a State-of-the-Art Mechanistic Disease Map
Authors: Miagoux Quentin , Singh Vidisha , de Mézquita Dereck , Chaudru Valerie , Elati Mohamed , Petit-Teixeira Elisabeth , Niarakis Anna
Published: August 2021

Rheumatoid arthritis (RA) is a multifactorial, complex autoimmune disease that involves various genetic, environmental, and epigenetic factors. Systems biology approaches provide the means to study complex diseases by integrating different layers of biological information. Combining multiple data types can help compensate for missing or conflicting information and limit the possibility of false positives. In this work, we aim to unravel mechanisms governing the regulation of key transcription factors in RA and derive patient-specific models to gain more insights into the disease heterogeneity and the response to treatment. We first use publicly available transcriptomic datasets (peripheral blood) relative to RA and machine learning to create an RA-specific transcription factor (TF) co-regulatory network. The TF cooperativity network is subsequently enriched in signalling cascades and upstream regulators using a state-of-the-art, RA-specific molecular map. Then, the integrative network is used as a template to analyse patients’ data regarding their response to anti-TNF treatment and identify master regulators and upstream cascades affected by the treatment. Finally, we use the Boolean formalism to simulate in silico subparts of the integrated network and identify combinations and conditions that can switch on or off the identified TFs, mimicking the effects of single and combined perturbations.
Prognostic Implication of Longitudinal Changes in Cardiothoracic Ratio and Aortic Arch Calcification in Hemodialysis Patients
Authors: Chung Tung-Ling , Liu Yi-Hsueh , Huang Jiun-Chi , Wu Pei-Yu , Tu Hung-Pin , Chen Szu-Chia , Chang Jer-Ming
Published: August 2021

Patients with end-stage renal disease have a high prevalence of cardiovascular disease. Chest radiography can be used to assess cardiothoracic ratio (CTR) and aortic arch calcification (AoAC). The aims of this longitudinal follow-up study were to investigate factors associated with changes in CTR and AoAC and understand whether these changes are associated with overall and cardiovascular mortality in hemodialysis (HD) patients. We enrolled 260 patients undergoing HD who had at least two available chest X-rays from 2008 to 2015. CTR and AoAC were assessed in each patient using measurements from baseline and annual chest X-rays. The CTR increased from 49.05% to 51.86% and the AoAC score increased from 3.84 to 9.73 over 7 years. The estimated slopes were 0.24 (p < 0.0001) for CTR and 0.08 (p = 0.0441) for AoAC. Increased AoAC, older age, female sex, coronary artery disease, and decreased albumin were associated with an increase in CTR, and older age, cerebrovascular disease, decreased albumin, increased Kt/V, and the use of antiplatelet agents were associated with an increase in AoAC. During follow-up, 136 of the 260 (52.3%) patients died, of whom 72 died due to cardiovascular causes. The change in CTR was greater in those who died (p = 0.0125) than in those who survived. The AoAC score was also higher in those who died than in those who survived, although there was no significant difference in the change in AoAC between the two groups (p = 0.8035). CTR and AoAC increased significantly over time in the HD patients in this longitudinal follow-up study, and the change in CTR was greater in those who died than in those who survived. Chest radiography is a simple and useful tool to assess the progression of CTR and AoAC as a prognostic marker.
Unique Endomembrane Systems and Virulence in Pathogenic Protozoa
Authors: Wiser Mark F.
Published: August 2021

Virulence in pathogenic protozoa is often tied to secretory processes such as the expression of adhesins on parasite surfaces or the secretion of proteases to assisted in tissue invasion and other proteins to avoid the immune system. This review is a broad overview of the endomembrane systems of pathogenic protozoa with a focus on Giardia, Trichomonas, Entamoeba, kinetoplastids, and apicomplexans. The focus is on unique features of these protozoa and how these features relate to virulence. In general, the basic elements of the endocytic and exocytic pathways are present in all protozoa. Some of these elements, especially the endosomal compartments, have been repurposed by the various species and quite often the repurposing is associated with virulence. The Apicomplexa exhibit the most unique endomembrane systems. This includes unique secretory organelles that play a central role in interactions between parasite and host and are involved in the invasion of host cells. Furthermore, as intracellular parasites, the apicomplexans extensively modify their host cells through the secretion of proteins and other material into the host cell. This includes a unique targeting motif for proteins destined for the host cell. Most notable among the apicomplexans is the malaria parasite, which extensively modifies and exports numerous proteins into the host erythrocyte. These modifications of the host erythrocyte include the formation of unique membranes and structures in the host erythrocyte cytoplasm and on the erythrocyte membrane. The transport of parasite proteins to the host erythrocyte involves several unique mechanisms and components, as well as the generation of compartments within the erythrocyte that participate in extraparasite trafficking.
Cobalt Oxide-Decorated Silicon Carbide Nano-Tree Array Electrode for Micro-Supercapacitor Application
Authors: Lee Chuan-Pei , Murti Bayu-Tri , Yang Po-Kang , Rossi Francesca , Carraro Carlo , Maboudian Roya
Published: August 2021

A cobalt oxide (Co3O4)-decorated silicon carbide (SiC) nano-tree array (denoted as Co3O4/SiC NTA) electrode is synthesized, and it is investigated for use in micro-supercapacitor applications. Firstly, the well-standing SiC nanowires (NWs) are prepared by nickel (Ni)-catalyzed chemical vapor deposition (CVD) method, and then the thin layer of Co3O4 and the hierarchical Co3O4 nano-flower-clusters are, respectively, fabricated on the side-walls and the top side of the SiC NWs via electrodeposition. The deposition of Co3O4 on the SiC NWs benefits the charge transfer at the electrode/aqueous electrolyte interface due to its extremely hydrophilic surface characteristic after Co3O4 decoration. Furthermore, the Co3O4/SiC NTA electrode provides a directional charge transport route along the length of SiC nanowires owing to their well-standing architecture. By using the Co3O4/SiC NTA electrode for micro-supercapacitor application, the areal capacitance obtained from cyclic voltammetry measurement reaches 845 mF cm−2 at a 10 mV s−1 scan rate. Finally, the capacitance durability is also evaluated by the cycling test of cyclic voltammetry at a high scan rate of 150 mV s−1 for 2000 cycles, exhibiting excellent stability.
Fatigue Performance of Metal–Composite Friction Spot Joints
Authors: Goushegir Seyed Mohammad , Santos Jorge F. dos , Amancio-Filho Sergio T.
Published: August 2021

Friction spot joining is an alternative technique for joining metals with polymers and composites. This study investigated the fatigue performance of aluminum alloy 2024/carbon-fiber-reinforced poly(phenylene sulfide) joints that were produced with friction spot joining. The surface of the aluminum was pre-treated using various surface treatment methods. The joined specimens were tested under dynamic loading using a load ratio of R = 0.1 and a frequency of 5 Hz. The tests were performed at different percentages of the lap shear strength of the joint. Three models—exponential, power law, and wear-out—were used to statistically analyze the fatigue life of the joints and to draw the stress–life (S–N) curves. The joints showed an infinite life of 25–35% of their quasi-static strength at 106 cycles. The joints surpassing 106 cycles were subsequently tested under quasi-static loading, showing no considerable reduction compared to their initial lap shear strength.
Assessment of Internal Damage in Sandwich Structures by Post-Processing of Mode Shapes Using Curvelet Transform
Authors: Katunin Andrzej , Ručevskis Sandris
Published: August 2021

Identification and quantification of structural damage is one of the crucial aspects of proper maintenance of mechanical and civil structures, which is directly related to their integrity and safety. The paper presents a novel approach for detecting various types of damage in sandwich structures by processing the mode shapes using a hybrid algorithm based on the curvelet transform and the standardized damage index concept. The proposed approach uses the properties of directional selectivity, absence of the boundary effect, typical of such a class of transforms, and excellent filtration capabilities of the curvelet transform as well as the classification hypothesis in the standardized damage index, which allows the exclusion of irrelevant information and emphasizes proper damage location and shape. The proposed hybrid algorithm allowed to successfully identify a subsurface core damage in sandwich structures, such as local lack of a core or its debonding from facings. The performed quantification study aimed to evaluate the correctness of identified damage shape confirmed the validity and accuracy of the proposed algorithm not only for the damage detection and localization but also for the estimation of the size of structural damage.
A Low-Profile Ultrawideband Antenna Based on Flexible Graphite Films for On-Body Wearable Applications
Authors: Li Wenhua , Zu Haoran , Liu Jinjin , Wu Bian
Published: August 2021

This paper presents a low-profile ultrawideband antenna for on-body wearable applications. The proposed antenna is based on highly conductive flexible graphite films (FGF) and polyimide (PI) substrate, which exhibits good benefits such as flexibility, light weight and corrosion resistance compared with traditional materials. By introducing flaring ground and an arrow-shaped slot, better impedance matching is achieved. The wearable antenna achieves a bandwidth of 122% from 0.34 GHz to 1.4 GHz, with a reflection coefficient of less than −10 dB, while exhibiting an omnidirectional pattern in the horizontal plane. To validate the proposed design, the wearable antenna with a profile of ~0.1 mm was fabricated and measured. The measured results are in good agreement with simulated ones, which indicates a suitable candidate for on-body wearable devices.
Indication of Strongly Correlated Electron Transport and Mott Insulator in Disordered Multilayer Ferritin Structures (DMFS)
Authors: Rourk Christopher , Huang Yunbo , Chen Minjing , Shen Cai
Published: August 2021

Electron tunneling in ferritin and between ferritin cores (a transition metal (iron) oxide storage protein) in disordered arrays has been extensively documented, but the electrical behavior of those structures in circuits with more than two electrodes has not been studied. Tests of devices using a layer-by-layer deposition process for forming multilayer arrays of ferritin that have been previously reported indicate that strongly correlated electron transport is occurring, consistent with models of electron transport in quantum dots. Strongly correlated electrons (electrons that engage in strong electron-electron interactions) have been observed in transition metal oxides and quantum dots and can create unusual material behavior that is difficult to model, such as switching between a low resistance metal state and a high resistance Mott insulator state. This paper reports the results of the effect of various degrees of structural homogeneity on the electrical characteristics of these ferritin arrays. These results demonstrate for the first time that these structures can provide a switching function associated with the circuit that they are contained within, consistent with the observed behavior of strongly correlated electrons and Mott insulators.
Effect of Strain on Heating Characteristics of Silicone/CNT Composites
Authors: Gnanaseelan Minoj , Trommer Kristin , Gude Maik , Stanik Rafal , Przybyszewski Bartlomiej , Kozera Rafal , Boczkowska Anna
Published: August 2021

In this work, silicone/carbon nanotube (CNT) composites were produced using a spread coating process, followed by morphological investigations and determination of their electrical properties and heating behaviour through the application of electric potential. Composites containing varying amounts of CNT (1–7%) were investigated for their thermal behaviour with the use of an IR camera. Subsequently, thermal behaviour and electrical properties were measured when the samples were stretched (up to 20%). With the 7% CNT composites, which had a conductivity of 106 S/m, it was possible to achieve a temperature of 155 °C at a relatively low voltage of 23 V. For high CNT contents, when the potential was controlled in such a way as to maintain the temperature well below 100 °C, the temperature remained almost constant at all levels of strain investigated. At higher potentials yielding temperatures around 100 °C and above, stretching had a drastic effect on temperature. These results are critical for designing composites for dynamic applications requiring a material whose properties remain stable under strain.
The Enhancement of Enargite Dissolution by Sodium Hypochlorite in Ammoniacal Solutions
Authors: Velásquez-Yévenes Lilian , Álvarez Hans , Quezada Víctor , García Antonio
Published: August 2021

The dissolution of both copper and arsenic from a copper concentrate was investigated in oxidative ammonia/ammonium solutions at moderate temperatures and atmospheric pressure. The main parameters studied were temperature, pH, concentrations of different ammonia salts, the presence of sodium hypochlorite, pretreatment with sodium chloride, and curing period. In all ammoniacal solutions studied, increasing the temperature enhanced the dissolution of copper, but the dissolution of arsenic remained marginal. Mixing the copper concentrate with sodium chloride and leaving it to rest for 72 h before leaching in ammoniacal solutions significantly increased the dissolution of copper and slightly increased the dissolution of arsenic from the concentrate. A maximum of 35% of Cu and 3.3% of As were extracted when ammonium carbonate was used as the lixiviant. The results show relatively rapid dissolution of the concentrate with the addition of sodium hypochlorite in ammonium carbonate solution, achieving a dissolution of up to 50% and 25% of copper and arsenic, respectively. A copper dissolution with a non-linear regression model was proposed, considering the effect of NaClO and NH4Cl at 25 °C. These findings highlight the importance of using the correct anionic ligands for the ammonium ions and temperature to obtain a high dissolution of copper or arsenic. The results also showed that the curing time of the packed bed before the commencement of leaching appeared to be an important parameter to enhance the dissolution of copper and leave the arsenic in the residues.
Validation of Adhesive and Temperature Property Characteristics of Microsurfacing by Performance-Based Mixture Design Approach
Authors: Shi Jicun , Jia Shili , Wang Lan , Zhang Qing , Han Hongxing , Chen Yilong , Song Zige , Zhao Lei
Published: August 2021

Performance-based mixture design of microsurfacing offers a promising solution to the best application of asphalt emulsions. The presented study investigated a novel approach to evaluate the spalling resistance and high and low-temperature resistance of microsurfacing. The laboratory tests, including mixture bond strength (MBS), driving wheel pavement analyzer (DWPA), multi-stress creep recovery (MSCR), load wheel rutting (LWR), and single edge notch beam (SENB) were conducted to characterize the performance-related properties; the response surface method (RSM) was used to obtain the optimal proportions of the mixture. According to the experimental results, the performance-based mixture design method improves the comprehensive performance of microsurfacing, such as adhesion at high and low temperatures. The results of RSM show that temperature is the most important factor that affects the adhesion of mixture. There is a strong correlation between adhesive and temperature performance detected by different test methods. Due to different chemical mechanisms caused by cement and emulsified asphalt, the high-temperature performance index of the microsurfacing mixture is lower than that of HMA. Furthermore, the low-temperature resistance is analyzed and suggested indicator is proposed.
Oxidation Behavior of Inconel 740H Nickel Superalloy in Steam Atmosphere at 750 °C
Authors: Kościelniak Barbara , Chmiela Bartosz , Sozańska Maria , Swadźba Radosław , Drajewicz Marcin
Published: August 2021

The oxidation behavior of the nickel superalloy Inconel 740H was studied at 750 °C for 100, 250, 500, 1000, and 2000 h in a steam atmosphere. Microstructure observations were performed using scanning electron microscopes and scanning-transmission electron microscope. The phase identification of existing oxidation products was conducted by electron diffraction in transmission electron microscope. The obtained results showed that the microstructure of Inconel 740H was stable during the oxidation process. The kinetic data showed that the superalloy has the ability to form protective oxide layers that are characterized by good adhesion and no tendency to spallation during the test. The oxidation products were mainly composed of external and internal oxides mainly at grain boundaries. The oxides in the external layer were Cr2O3, MnTiO3,, and α-Al2O3 after 2000 h of oxidation. Internal oxides were α-Al2O3 and TiO2. The occurrence of discontinuities in the internal oxidation zone was also observed after 500 h of test. It was found that the thickness of the internal oxidation zone was greater than the thickness of the external oxide layer, which proves the strong tendency of the superalloy to form internal oxides after oxidation in the steam atmosphere.
Study on X-ray Emission Using Ultrashort Pulsed Lasers in Materials Processing
Authors: Schille Joerg , Kraft Sebastian , Pflug Theo , Scholz Christian , Clair Maurice , Horn Alexander , Loeschner Udo
Published: August 2021

The interaction of ultrashort pulsed laser radiation with intensities of 1013 W cm−2 and above with materials often results in an unexpected high X-ray photon flux. It has been shown so far, on the one hand, that X-ray photon emissions increase proportionally with higher laser power and the accumulated X-ray dose rates can cause serious health risks for the laser operators. On the other hand, there is clear evidence that little variations of the operational conditions can considerably affect the spectral X-ray photon flux and X-ray emissions dose. In order to enhance the knowledge in this field, four ultrashort pulse laser systems for providing different complementary beam characteristics were employed in this study on laser-induced X-ray emissions, including peak intensities between 8 × 1012 W∙cm−2 < I0 < 5.2 × 1016 W∙cm−2, up to 72.2 W average laser power as well as burst/bi-burst processing mode. By the example of AISI 304 stainless steel, it was verified that X-ray emission dose rates as high as H˙′ (0.07) > 45 mSv h−1 can be produced when low-intensity ultrashort pulses irradiate at a small 1 µm intra-line pulse distance during laser beam scanning and megahertz pulse repetition frequencies. For burst and bi-burst pulses, the second intra-burst pulse was found to significantly enhance the X-ray emission potentially induced by laser pulse and plasma interaction.
Structural, Thermal and Magnetic Analysis of Fe75Co10Nb6B9 and Fe65Co20Nb6B9 Nanostructured Alloys
Authors: Carrillo Albert , Daza Jason , Saurina Joan , Escoda Lluisa , Suñol Joan-Josep
Published: August 2021

Two nanocrystalline ferromagnetic alloys of the Fe-Co-Nb-B system have been produced by mechanical alloying (MA). Their microstructure, thermal behavior and magnetic response were checked by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and vibrating sample magnetometry (VSM). After 80 h of MA, the alloys were nanostructured (bcc-Fe(Co)-rich phase). As the Co content increases, the density of the dislocations decreases. Besides, a higher concentration of Co causes an increase in the activation energy of the crystallization process. The calculated energies, 267 and 332 kJ/mol, are associated to the crystalline growth of the bcc-Fe-rich phase. The Co content of the samples has no effect on the value of the saturation magnetization, whereas the coercivity is lower in the alloy containing less Co. Samples were compacted and heat-treated. Optimal annealing reduces the coercivity by a factor of two. Results were compared with the data of Fe-Nb-B and Fe-Ni-Nb-B alloys.
Isolation, Phylogenetic and Gephyromycin Metabolites Characterization of New Exopolysaccharides-Bearing Antarctic Actinobacterium from Feces of Emperor Penguin
Authors: Gao Hui-Min , Xie Peng-Fei , Zhang Xiao-Ling , Yang Qiao
Published: August 2021

A new versatile actinobacterium designated as strain NJES-13 was isolated from the feces of the Antarctic emperor penguin. This new isolate was found to produce two active gephyromycin analogues and bioflocculanting exopolysaccharides (EPS) metabolites. Phylogenetic analysis based on pairwise comparison of 16S rRNA gene sequences showed that strain NJES-13 was closely related to Mobilicoccus pelagius Aji5-31T with a gene similarity of 95.9%, which was lower than the threshold value (98.65%) for novel species delineation. Additional phylogenomic calculations of the average nucleotide identity (ANI, 75.9–79.1%), average amino acid identity (AAI, 52.4–66.9%) and digital DNA–DNA hybridization (dDDH, 18.6–21.9%), along with the constructed phylogenomic tree based on the up-to-date bacterial core gene (UBCG) set from the bacterial genomes, unequivocally separated strain NJES-13 from its close relatives within the family Dermatophilaceae. Hence, it clearly indicated that strain NJES-13 represented a putative new actinobacterial species isolated from the gut microbiota of mammals inhabiting the Antarctic. The obtained complete genome of strain NJES-13 consisted of a circular 3.45 Mb chromosome with a DNA G+C content of 67.0 mol%. Furthering genome mining of strain NJES-13 showed the presence of five biosynthetic gene clusters (BGCs) including one type III PKS responsible for the biosynthesis of the core of gephyromycins, and a series of genes encoding for bacterial EPS biosynthesis. Thus, based on the combined phylogenetic and active metabolites characterization presented in this study, we confidently conclude that strain NJES-13 is a novel, fresh actinobacterial candidate to produce active gephyromycins and microbial bioflocculanting EPS, with potential pharmaceutical, environmental and biotechnological implications.
Drawing-Induced Evolution of Inclusions in Cold-Drawn Pearlitic Steel
Authors: Toribio Jesús , Ayaso Francisco-Javier , Rodríguez Rocío
Published: August 2021

This article focuses on the analysis of the evolution of inclusions present in eutectoid pearlitic steel subjected to a real cold drawing process. To this end, wires belonging to different stages of the manufacture chain were studied, starting from an initial hot rolled bar (not cold drawn at all). In addition to the information obtained through visual inspection, a quantitative analysis of the microdefects generated by these inclusions was carried out. The analysis was performed using materialographic techniques, scanning electron microscopy (SEM) and the image analysis program (AnaliSYS 3.1®).
Kidney Allograft Function Is a Confounder of Urine Metabolite Profiles in Kidney Allograft Recipients
Authors: Suhre Karsten , Dadhania Darshana M. , Lee John Richard , Muthukumar Thangamani , Chen Qiuying , Gross Steven S. , Suthanthiran Manikkam
Published: August 2021

Noninvasive biomarkers of kidney allograft status can help minimize the need for standard of care kidney allograft biopsies. Metabolites that are measured in the urine may inform about kidney function and health status, and potentially identify rejection events. To test these hypotheses, we conducted a metabolomics study of biopsy-matched urine cell-free supernatants from kidney allograft recipients who were diagnosed with two major types of acute rejections and no-rejection controls. Non-targeted metabolomics data for 674 metabolites and 577 unidentified molecules, for 192 biopsy-matched urine samples, were analyzed. Univariate and multivariate analyses identified metabolite signatures for kidney allograft rejection. The replicability of a previously developed urine metabolite signature was examined. Our study showed that metabolite profiles can serve as biomarkers for discriminating rejection biopsies from biopsies without rejection features, but also revealed a role of estimated Glomerular Filtration Rate (eGFR) as a major confounder of the metabolite signal.
Improving the Performance of Micro-Textured Cutting Tools in Dry Milling of Ti-6Al-4V Alloys
Authors: Wu Ze , Xing Youqiang , Chen Jiansong
Published: August 2021

Micro-textured tools were fabricated by making textures on rake faces and filling them with molybdenum disulfide. Dry milling of Ti-6Al-4V alloys was carried out with the micro-textured tools and conventional tools for comparison. Results showed that micro-textured tools can reduce the resultant cutting forces, cutting temperatures, and power consumption by approximately 15%, 10%, and 5%, respectively. Meanwhile, the developed tools can improve tool lives by approximately 20–25%. The radial width of cut, the cutting speed, and the axial depth of cut all had statistical and physical effects on the energy consumption per unit of volume in dry milling of Ti-6Al-4V alloys, while the feed per tooth seemed to have no significant effect. The mechanism for improved performance of micro-textured tools can be mainly interpreted as their self-lubricating function.
A Low-Cost 3-in-1 3D Printer as a Tool for the Fabrication of Flow-Through Channels of Microfluidic Systems
Authors: Thaweskulchai Thana , Schulte Albert
Published: August 2021

Recently published studies have shown that microfluidic devices fabricated by in-house three-dimensional (3D) printing, computer numerical control (CNC) milling and laser engraving have a good quality of performance. The 3-in-1 3D printers, desktop machines that integrate the three primary functions in a single user-friendly set-up are now available for computer-controlled adaptable surface processing, for less than USD 1000. Here, we demonstrate that 3-in-1 3D printer-based micromachining is an effective strategy for creating microfluidic devices and an easier and more economical alternative to, for instance, conventional photolithography. Our aim was to produce plastic microfluidic chips with engraved microchannel structures or micro-structured plastic molds for casting polydimethylsiloxane (PDMS) chips with microchannel imprints. The reproducability and accuracy of fabrication of microfluidic chips with straight, crossed line and Y-shaped microchannel designs were assessed and their microfluidic performance checked by liquid stream tests. All three fabrication methods of the 3-in-1 3D printer produced functional microchannel devices with adequate solution flow. Accordingly, 3-in-1 3D printers are recommended as cheap, accessible and user-friendly tools that can be operated with minimal training and little starting knowledge to successfully fabricate basic microfluidic devices that are suitable for educational work or rapid prototyping.
The Effect of Microparticles on the Storage Modulus and Durability Behavior of Magnetorheological Elastomer
Authors: Johari Mohd Aidy Faizal , Mazlan Saiful Amri , Nordin Nur Azmah , Ubaidillah U , Aziz Siti Aishah Abdul , Nazmi Nurhazimah , Johari Norhasnidawani , Choi Seung-Bok
Published: August 2021

This paper presents the effect of the micro-sized particles on the storage modulus and durability characteristics of magnetorheological elastomers (MREs). The initial phase of the investigation is to determine any associations among the microparticles’ weight percent fraction (wt%), structure arrangement, and the storage modulus of MRE samples. In order to carry out this, both isotropic and anisotropic types of MRE samples consisting of the silicone rubber matrix and 50, 60, 70, 75, and 80 wt% microparticles of carbonyl iron fractions are prepared. It is identified from the magneto-rheometer that the increase in storage modulus and decrease in linear viscoelastic region limit are observed in varying consistency depending on wt% and particle arrangement. The consistency of this dependency feature is highlighted by superimposing all of the graphs plotted to create the proposed the samples’ behavior model. In response to increasing magnetic stimulation, a sample of 70 wt% microparticles with an isotropic arrangement is found to be significant and stable. The experimentally defined fraction is then used for the durability test as the second phase of the investigation. During this phase, the durability evaluation is subjected to stress relaxation for an extended period of time. After undergoing durability testing, storage modulus performance is decreased by 0.7–13% at various magnetic stimulation levels. This result directly indicates that the storage modulus characteristics of different forms of MRE are sensitive to the different iron particle fractions’ and microparticles’ alignment. Therefore, important treatments to alter the storage modulus can be undertaken before the practical implementation to accommodate any desired performance of MRE itself and MRE application systems.
Research on Multi-Physics Coupling Simulation for the Pulse Electrochemical Machining of Holes with Tube Electrodes
Authors: Li Zhaolong , Cao Bingren , Dai Ye
Published: August 2021

Electrical parameters of the power supply are significant factors affecting the accuracy and stability of the electrochemical machining (ECM). However, the electric field, flow velocity and temperature in the machining area are difficult to measure directly under the influence of the power supply. Therefore, taking the film cooling hole as an example, the multi-physics coupling simulation analysis of the ECM is performed on the basis of Faraday’s law and fluid heat transfer mathematical model. The machining characteristics of the direct current and pulse ECM are compared through simulation. The results show that the pulse ECM improves the distribution of temperature and current density in the machining area. The period has little effect on the temperature, current density and side removal rate. The side removal rate increases with the increase of the duty ratio and lateral gap. Increasing of the duty ratio and decreasing of the lateral gap will increase the temperature and current density. Increasing the inlet pressure accelerates the frequency of renewal of heat and electrolysis products, which can reduce the single side gap. The experience of the ECM holes verifies the results of the simulation. The accuracy and stability of the ECM of holes are enhanced by optimizing the duty ratio, lateral gap and inlet pressure.
Analyzing the Effect of Particle Shape on Deformation Mechanism during Cutting Simulation of SiC P/Al Composites
Authors: Zhou Jiakang , Lin Jieqiong , Lu Mingming , Jing Xian , Jin Yubo , Song Dunlan
Published: August 2021

To analyze the effect of particle shape on deformational behavior in the cutting simulation process for metal matrix composites (MMCs), two 2D mesoscopic-based finite element (FE) models reinforced with randomly distributed circular and irregular polygonal particles were developed. Different material properties (metal matrix phase, particle reinforced phase) and the properties of the particle–matrix interface were comprehensively considered in the proposed FE model. Systematic cutting experiments were conducted to compare the differences between two modeling approaches with respect to particle fracture, chip formation, cutting force and surface integrity. The results show that the irregular polygonal particle model is closer to the microstructure of MMCs, and is better able to reflect the deformation behavior of particles. The simulation model with irregular polygonal particles is even able to capture more details of the impact caused by particles, reflecting variations in the cutting force in the actual cutting process. The initiation and propagation of microcracks is mainly determined on the basis of particle geometry and further affects chip formation. Both models are able to correctly reflect surface defects, but the irregular polygonal particle model provides a more comprehensive prediction for the subsurface damage of MMCs.
Simulation Guided Hand-Driven Portable Triboelectric Nanogenerator: Design, Optimisation, and Evaluation
Authors: Wang Yunzhong , Pham Anh , Tohl Damian , Tang Youhong
Published: August 2021

Inspired by the fundamental mechanics of an ancient whirligig (or buzzer toy; 3300 BC), a hand-driven rotational triboelectric nanogenerator (HDR-TENG) was designed and optimised, guided by our recently reported mathematical modelling. This modelling indicates that the power generated by HDR-TENG is a function of the number of segments, rotational speed, and tribo-surface spacing with different weighting sensitivities. Based on the simulation results, additive manufacturing technology was combined with commercially available components to cost-effectively fabricate the HDR-TENG. The fabricated HDR-TENG can provide stable and adjustable rotational speed up to 15,000 rpm with a linear hand stretching. The output voltage of HDR-TENG maintains a constant value within 50,000 cycles of testing when using Nylon 66 and PTFE as the triboelectric material. It can charge a 47 μF capacitor to 2.2 V in one minute. This study provides a cost-effective portable HDR-TENG device with adjustable high rotational speed, high power output, and long durable life, creating opportunities to provide a power supply for point-of-care devices in remote or resource-poor settings and applications in science and engineering education.
Oral Supplementation with Hydrolyzed Fish Cartilage Improves the Morphological and Structural Characteristics of the Skin: A Double-Blind, Placebo-Controlled Clinical Study
Authors: Maia Campos Patrícia Maria Berardo Gonçalves , Franco Rodolfo Scarpino Barboza , Kakuda Letícia , Cadioli Gabriel Fernandes , Costa Gabriela Maria D’Angelo , Bouvret Elodie
Published: August 2021

Collagen and its peptides are natural ingredients used in food supplements and nutricosmetics with the claim of providing benefits for skin health and beauty. In this context, the aim of the present study was to evaluate the clinical efficacy of oral supplementation with hydrolyzed fish cartilage for the improvement of chronological and photoaging-induced skin changes. A total of 46 healthy females aged 45 to 59 years were enrolled and divided into two groups: G1—placebo and G2—oral treatment with hydrolyzed fish cartilage. Measurements of skin wrinkles, dermis echogenicity and thickness, and morphological and structural characteristics of the skin were performed in the nasolabial region of the face before and after a 90-day period of treatment using high-resolution imaging, ultrasound, and reflectance confocal microscopy image analyses. A significant reduction in wrinkles and an increase of dermis echogenicity were observed after a 90-day period of treatment with hydrolyzed fish cartilage compared to the placebo and baseline values. In addition, reflectance confocal microscopy (RCM) image analysis showed improved collagen morphology and reduced elastosis after treatment with hydrolyzed fish cartilage. The present study showed the clinical benefits for the skin obtained with oral supplementation with a low dose of collagen peptides from hydrolyzed fish cartilage.
Starch Formates: Synthesis and Modification
Authors: Blohm Sascha , Heinze Thomas , Qi Haisong
Published: August 2021

Starch can be efficiently converted into the corresponding formates homogeneously using N-formyl imidazole obtained by the reaction of 1,1′-carbonyldiimidazole and formic acid in dimethyl sulfoxide as a solvent. Starch formates are soluble in polar aprotic solvents, not susceptible against hydrolysis, and not meltable. Thermoplastics could be generated by conversion of starch formates with long-chain fatty acids exemplified by the conversion with lauroyl chloride in N,N-dimethylacetamide, leading to mixed starch laurate formates. The mixed esters show melting temperatures mainly dependent on the amount of laurate ester moieties.
Halogens in Acetophenones Direct the Hydrogen Bond Docking Preference of Phenol via Stacking Interactions
Authors: Zimmermann Charlotte , Lange Manuel , Suhm Martin A.
Published: August 2021

Phenol is added to acetophenone (methyl phenyl ketone) and to six of its halogenated derivatives in a supersonic jet expansion to determine the hydrogen bonding preference of the cold and isolated 1:1 complexes by linear infrared spectroscopy. Halogenation is found to have a pronounced effect on the docking site in this intermolecular ketone balance experiment. The spectra unambiguously decide between competing variants of phenyl group stacking due to their differences in hydrogen bond strength. Structures where the phenyl group interaction strongly distorts the hydrogen bond are more difficult to quantify in the experiment. For unsubstituted acetophenone, phenol clearly prefers the methyl side despite a predicted sub-kJ/mol advantage that is nearly independent of zero-point vibrational energy, turning this complex into a challenging benchmark system for electronic structure methods, which include long range dispersion interactions in some way.
A Natural Degradant of Curcumin, Feruloylacetone Inhibits Cell Proliferation via Inducing Cell Cycle Arrest and a Mitochondrial Apoptotic Pathway in HCT116 Colon Cancer Cells
Authors: Chou Yu-Ting , Koh Yen-Chun , Nagabhushanam Kalyanam , Ho Chi-Tang , Pan Min-Hsiung
Published: August 2021

Feruloylacetone (FER) is a natural degradant of curcumin after heating, which structurally reserves some functional groups of curcumin. It is not as widely discussed as its original counterpart has been previously; and in this study, its anticancer efficacy is investigated. This study focuses on the suppressive effect of FER on colon cancer, as the efficacious effect of curcumin on this typical cancer type has been well evidenced. In addition, demethoxy-feruloylacetone (DFER) was applied to compare the effect that might be brought on by the structural differences of the methoxy group. It was revealed that both FER and DFER inhibited the proliferation of HCT116 cells, possibly via suppression of the phosphorylated mTOR/STAT3 pathway. Notably, FER could significantly repress both the STAT3 phosphorylation and protein levels. Furthermore, both samples showed capability of arresting HCT116 cells at the G2/M phase via the activation of p53/p21 and the upregulation of cyclin-B. In addition, ROS elevation and changes in mitochondrial membrane potential were revealed, as indicated by p-atm elevation. The apoptotic rate rose to 36.9 and 32.2% after being treated by FER and DFER, respectively. In summary, both compounds exhibited an anticancer effect, and FER showed a greater proapoptotic effect, possibly due to the presence of the methoxy group on the aromatic ring.