bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation of Electrospun Active Molecules Membrane Application to Atmospheric Free Radicals
Authors: Yang Yang , Wang Guoying , Li Xin , Iradukunda Yves , Liu Fengshuo , Li Zhiqian , Gao Hongli , Shi Gaofeng
Published: April 2022

Atmospheric reactive oxygen species (ROS) play a key role in the process of air pollution and oxidative damage to organisms. The analysis of ROS was carried out by the capture-derivative method. Therefore, it is necessary to prepare an effective molecular membrane to trap and detect ROS. Electrospinning membranes were prepared by combining the electrospinning technique with chrysin, baicalein, scutellarin, genistein, quercetin, and baicalin. By comparing the structures of the membranes before and after the reaction, the fluorescence enhancement characteristics of the reactive molecular membranes and the atmospheric radicals were studied. The ability of the active molecular membranes to trap atmospheric radicals was also studied. It was found that the genistein active molecular membrane had good trapping ability in four environments. The fluorescence enhancement rates in ROS, OH radical and O3 simulated environments were 39.32%, 7.99% and 11.92%, respectively. The fluorescence enhancement rate in atmospheric environment was 16.16%. Indeed, the sites where the atmospheric radicals react with the active molecular membranes are discussed. It is found that it is mainly related to the 5,7 phenolic hydroxyl of ring A, catechol structure and the coexistence structure of 4′ phenolic hydroxyl of ring B and 7 phenolic hydroxyl of ring A. Therefore, the genistein molecular membrane has shown great potential in its trapping ability and it is also environmentally friendly.
Dual-Structure PVDF/SDS Nanofibrous Membranes for Highly Efficient Personal Protection in Mines
Authors: Zhou Gang , Liu Rulin , Xu Qingfeng , Wang Kaili , Wang Yongmei , Ramakrishna Seeram
Published: April 2022

Pneumoconiosis in miners is considered a global problem. Improving the performance of individual protective materials can effectively reduce the incidence of pneumoconiosis. In this study, the blend membrane of sodium dodecyl sulfate and polyvinylidene fluoride with a dual structure was prepared using electrospinning techniques, and the morphological structure, fiber diameter, and filtration performance of the nanofiber membranes were optimized by adjusting the PVDF concentration and SDS content. The results show that the incorporation of SDS enabled the nanofiber membranes to show tree-like and beaded fibers. Compared with the original PVDF membrane, the small content of tree-like fibers and beaded fibers can improve the filtration efficiency and reduce the resistance of the fiber membrane. The prepared nanofiber membrane has excellent comprehensive filtration performance, and the quality factor is 0.042 pa−1 when the concentration of PVDF is 10 wt% and the addition of SDS is 0.1 wt%. Furthermore, after high-temperature treatment, the membrane could still maintain good filtration performance. The PVDF/SDS blend nanofiber membrane has outstanding filtration efficiency and good thermal stability and can fully meet the personal protection of miners in underground high-temperature operation environments.
A Langmuir-Blodgett Study of the Interaction between Amphotericin B and Lipids of Histoplasma capsulatum
Authors: Araque-Marín Pedronel , Naranjo Díaz Andrea , Gómez Londoño Luisa Fernanda , Jiménez Alzate María del Pilar , Castelli Francesco , Sarpietro Maria Grazia , Giordani Cristiano , Peláez Jaramillo Carlos Alberto
Published: April 2022

Histoplasma capsulatum is a dimorphic, thermal, and nutritional fungus. In the environment and at an average temperature of 28 °C, it develops as a mold that is composed of infecting particles. Once in the host or in cultures at 37 °C, it undergoes a transition into the parasitic form. In the present work, we performed chemical extraction and characterization using chromatography techniques of the associated lipid composition of the external surface of the cell wall of the mycelial phase of two isolates of the H. capsulatum: one clinical and one environmental. Several differences were evidenced in the fatty acids in the phospholipid composition. Surface pressure–area isotherms and compression module curves of the Amphotericin B and lipid extract monolayers, as well as (AmB)-lipid extract mixed monolayers were recorded. Results show a high affinity of AmB towards lipid extracts. The most stable monolayers were formed by AmB + environmental with a mass ratio of 1:3 and AmB + clinical with a mass ratio of 1:2. Knowledge of the AmB aggregation processes at a molecular level and the characterization of the lipid extracts allows the possibility to understand the interaction between the AmB and the lipid fractions of H. capsulatum.
Zinc–Tin Oxide Film as an Earth-Abundant Material and Its Versatile Applications to Electronic and Energy Materials
Authors: Seo Juhyung , Yoo Hocheon
Published: April 2022

Zinc–Tin Oxide (ZTO) films potentially offer desirable properties for next-generation devices and are considered promising candidates due to the following merits: (I) zinc and tin are abundant on Earth, with estimated reserves of approximately 250 million tons and 4.3 billion tons, respectively, (II) zinc and tin are harmless to the human body, and (III) large-area manufacturing with various synthesis processes is available. Considering the advantages and promises of these ZTO films, this review provides a timely overview of the progress and efforts in developing ZTO-based electronic and energy devices. This review revisits the ZTO films used for various device applications, including thin-film transistors, memory devices, solar cells, and sensors, focusing on their strong and weak points. This paper also discusses the opportunities and challenges for using ZTO films in further practical electronic and energy device applications.
A Membrane with Strong Resistance to Organic and Biological Fouling Using Graphene Oxide and D-Tyrosine as Modifiers
Authors: Guo Jiarui , Zhang Yan , Chen Fenghua , Chai Yuman
Published: April 2022

Membrane fouling markedly influences the service life and performance of the membrane during the using process. Herein, hydrophilic polyvinylidene fluoride (PVDF) nanocomposite (P-GO-DAA) membranes with antifouling and anti-biofouling characteristics were fabricated by employing graphene oxide (GO) and different concentrations of D-Tyrosine. The structural properties of the prepared nanocomposite membranes as well as pure PVDF membranes were characterized using FTIR, XPS, SEM, AFM, and contact angle analysis. It was found that the introduction of GO fillers made an excellent antifouling performance compared to pure PVDF indicated by the pure water flux, flux recovery rate, and rejection rate during ultrafiltration experiments as a result of the formation of the hydrophilic and more porous membrane. In particular, the nanocomposite membranes showed an increased flux of 305.27 L/(m2·h) and the rejection of 93.40% for the mixed pollutants solution (including Bull Serum Albumin, Sodium Alginate, and Humic Acid). Besides, the outstanding anti-biofouling activity was shown by the P-GO-DAA membrane with the properties of D-Tyrosine for inhibiting biofilm formation during the bacterial adhesion experiments. Furthermore, the adhesion ratio of bacteria on the membrane was 26.64% of the P-GO-DAA membrane compared to 84.22% of pure PVDF. These results were confirmed by CLSM.
PAC-UF Process Improving Surface Water Treatment: PAC Effects and Membrane Fouling Mechanism
Authors: Li Tian , Yu Hongjian , Tian Jing , Liu Junxia , Yuan Tonghao , Xiao Shaoze , Chu Huaqiang , Dong Bingzhi
Published: April 2022

In this study, the water purification effect and membrane fouling mechanism of two powdered activated carbons (L carbon and S carbon) enhancing Polyvinylidene Fluoride (PVDF) ultrafiltration (UF) membranes for surface water treatment were investigated. The results indicated that PAC could effectively enhance membrane filtration performance. With PAC addition, organic removal was greatly enhanced compared with direct UF filtration, especially for small molecules, i.e., the S-UF had an additional 25% removal ratio of micro-molecule organics than the direct UF. The S carbon with the larger particle size and lower specific surface area exhibited superior performance to control membrane fouling, with an operation duration of S-UF double than the direct UF. Therefore, the particle size and pore structure of carbon are the two key parameters that are essential during the PAC-UF process. After filtration, acid and alkaline cleaning of UF was conducted, and it was found that irreversible fouling contributed the most to total filtration resistance, while the unrecoverable irreversible resistance ratio with acid cleaning was greater than that with alkaline cleaning. With PAC, irreversible UF fouling could be relieved, and thus, the running time could be extended. In addition, the membrane foulant elution was analyzed, and it was found to be mainly composed of small and medium molecular organic substances, with 12% to 21% more polysaccharides than proteins. Finally, the hydrophilicity of the elution was examined, and it was observed that alkaline cleaning mainly eluted large, medium, and small molecules of hydrophilic and hydrophobic organic matter, while acid cleaning mainly eluted small molecules of hydrophilic organic matter.
Application of Cyclized Polyacrylonitrile for Ultrafiltration Membrane Fouling Mitigation
Authors: Pulyalina Alexandra , Tian Nadezhda , Senchukova Anna , Faykov Ilya , Ryabikova Maria , Novikov Alexander , Saprykina Natalia , Polotskaya Galina
Published: April 2022

In this study, novel composites were produced by blending partially cyclized polyacrylonitrile (cPAN) and poly(amide-imide) (PAI) in N-methylpyrrolidone in order to fabricate asymmetric membranes via phase inversion method. The compatibility of PAI and cPAN through possible intermolecular interaction was examined by quantum chemical calculations. The composite membranes were characterized by FTIR, SEM, contact angle measurements, etc. A considerable reduction in the contact angles of water and ethylene glycol (EG) was observed after adding cPAN to the PAI membrane, which is evidence of improved membrane hydrophilicity. Membrane transport properties were investigated in ultrafiltration tests by measuring the pure water flux, rejection of proteins, and flux recovery ratio (FRR). The best properties were found for the membrane containing 5 wt% cPAN; an increase in BSA rejection and a remarkable increase in FRR were observed, which can be explained by the hydrophilization of the membrane surface provided by the presence of cPAN.
Evaluation of Circumferential Mechanical Properties of Tubular Material by Flaring Test
Authors: Zhang Zicheng , Li Bin , Manabe Ken-Ichi , Sato Hideki
Published: April 2022

The investigation into the circumferential mechanical properties of tubular materials has been receiving increasing attention, since the tube hydroforming process has been used in the tubular materials forming field, because the circumferential mechanical properties have a significant effect on the hydroformability of the tubular materials. In the present study, a method for evaluation of the circumferential mechanical properties of the tubular materials with the flaring test was proposed. The expressions for the yield stress, strain hardening coefficient and exponent values of the tube were successfully derived based on the geometrical and mechanical relationships in the tube flaring test. To verify the reliability of this method, the calculated results of the yield stress, strain hardening coefficient and exponent values, obtained from the newly proposed method, were compared to the ones obtained with the conventional tensile tests. It was found that the method proposed in the current study is reliable, with high accuracy. The method is appropriate to evaluate the circumferential mechanical properties of the tubular materials.
Pyrometrical Interlayer Temperature Measurement in WAAM of Thin Wall: Strategies, Limitations and Functionality
Authors: Jorge Vinicius Lemes , Teixeira Felipe Ribeiro , Scotti Américo
Published: April 2022

Significant efforts have been spent determining or monitoring interlayer temperatures (IT) to increase quality in Wire Arc Additive Manufacturing (WAAM). However, an uneven thermal profile in the wall and a temperature gradient along the layer length are expected after a thin wall layer deposition, questioning the effectiveness of IT and its measuring approaches. After identifying the holistic meaning of IT, this work aimed at confronting two strategies using infrared pyrometers, elucidating their advantages and limitations for both open and closed-loop control. The proposed Upper and Sideward Pyrometer strategies were presented in detail and then assessed at different distances from the heat source. A calibration procedure was proposed. The results confirmed the existence of a natural temperature gradient along the wall. In addition, they showed how differently the arc heat affects the measured points (in intensity and steadiness) according to the strategy. Therefore, the interlayer temperature measured at a specific point on a part manufactured by WAAM should be taken as a reference and not an absolute value; the absolute value changes according to the measuring approach, sensor positioning and calibration. Using a temperature reference, both strategies can be used in open-loop control to reach repeatability (geometrical and metallurgical) between layers. However, the Sideward Pyrometer strategy is more recommended for feedback control of production, despite being less flexible.
Effect of Vibration Acceleration on Interface Microstructure and Bonding Strength of Mg–Al Bimetal Produced by Compound Casting
Authors: Guan Feng , Fan Suo , Wang Junlong , Li Guangyu , Zhang Zheng , Jiang Wenming
Published: April 2022

Vibration was adopted to enhance the interface bonding of Mg–Al bimetal prepared by the lost foam compound casting (LFCC) technique. The Mg–Al bimetallic interface was composed of three layers: layer I (Al3Mg2 and Mg2Si phases), layer II (Al12Mg17 and Mg2Si phases), and layer III (Al12Mg17 + δ-Mg eutectic structure). With the increase in vibration acceleration, the cooling rate of the Mg–Al bimetal increased, resulting in the decrease in the reaction duration that generates the intermetallic compounds (IMCs) layer (including layers I and II) and its thickness. On the other hand, the Mg2Si phase in the IMCs layer was refined, and its distribution became more uniform with the increase in the vibration acceleration. Finally, the shear strength of the Mg–Al bimetal continued to increase to 45.1 MPa when the vibration acceleration increased to 0.9, which was 40% higher than that of the Mg–Al bimetal without vibration.
Effect of High-Temperature Heat Treatment on Strengthening Mechanism of AlCoCrFeNi Component Fabricated by LMD
Authors: Pang Zheng , Yang Jin , Manladan Sunusi Marwana , Cai Yangchuan , Han Jian
Published: April 2022

In the present study; an AlCoCrFeNi high-entropy alloy (HEA) component was produced by laser melting deposition (LMD) technique. Then; a heat-treatment process based on the detection results of Differential Scanning Calorimeter (DSC) was used. The effects of heat treatment on the phase transition; microstructure and mechanical properties of the AlCoCrFeNi component were systematically studied. The results showed that low-temperature heat treatment (600 °C) had little effect on the microstructure and mechanical properties of component. The 800 °C heat treatment precipitated σ and face-center cubic (FCC) phases near grain boundaries in the component. The high dislocation capacity of FCC phase and precipitation strengthening of σ phase improved the strength and plasticity of this component. However; hard and brittle σ phase was not conducive to uniform distribution of microhardness. High-temperature heat treatment (1000 °C) caused the σ phase to remelt and increased FCC phase content at grain boundaries; resulting in a significant increase in strength and plasticity. Although the microhardness of the AlCoCrFeNi component after this heat treatment was reduced; the good strength and plasticity will facilitate its application in the structural field.
Phase Equilibria of CaO-SiO2-La2O3-Nb2O5 System in Reducing Atmosphere
Authors: Sun Lifeng , Liu Zhengyue , Jiang Maofa
Published: April 2022

In the current work, the phase equilibria of CaO-SiO2-La2O3-Nb2O5 system at 1200 °C in reducing atmosphere (PO2 = 10−15 atm) was investigated according to the melting separation process for extracting lanthanum and niobium resources from Bayan Obo tailing. High temperature equilibrium experiment, scanning electron microscope, and energy dispersive spectrometer (SEM-EDS) were used to determine the compositions of equilibrium phases. According to the experiment results, the phase equilibria of the CaO-SiO2-La2O3-Nb2O5 system in reducing atmosphere were ascertained and the 1200 °C isothermal phase diagram of CaO-SiO2-La2O3-Nb2O5 system in reducing atmosphere was constructed. The research results not only play an important role in guiding the development of the lanthanum and niobium extraction process, but also enrich the thermodynamic data of relevant silicate slag systems.
Electrochemical Behavior and Surface Conductivity of C/TiC Nanocomposite Coating on Titanium for PEMFC Bipolar Plate
Authors: Meng Wei , Zhu Haifeng , Wang Xiaopeng , Li Guanghui , Fan Yingze , Sun Deen , Kong Fantao
Published: April 2022

In this study, a C/TiC nanocomposite coating has been prepared by magnetron sputtering technology and vacuum heat treatment technology on a titanium surface, which is used for bipolar plates (BPs) in a proton exchange membrane fuel cell (PEMFC). This prepared C/TiC nanocomposite coating was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, electrochemical testing and interfacial contact resistance (ICR). The results show that a C/TiC nanocomposite coating consists of a single C surface layer (~28.88 nm) and TiC interface layer (~19.5 nm). In addition, compared with commercially pure titanium substrate (icorr = 345.10 μA cm−2), the corrosion resistance of a C/TiC nanocomposite coating (icorr = 0.74 μA cm−2) was greatly improved in 0.5 M H2SO4 + 5 ppm HF solution at 80 °C. The corrosion current density (icorr) decreased 3 orders of magnitude in a simulated cathodic environment. Moreover, the interfacial contact resistance of a C/TiC nanocomposite coating is 2.34 mΩ cm2 under 1.4 MPa compaction force, which is much lower than that of raw CP Ti (38.66 mΩ cm2).
Microstructures, Mechanical Behavior, and Radiation Damage of (TiVCr)x-(TaW)1-x Binary System High-Entropy Alloy Films
Authors: Li Rongbin , Huang Tian , Zhang Jing , Jiang Chunxia , Zhang Yong , Liaw Peter
Published: April 2022

An experimental method for preparing high-entropy thin films with gradient changes of alloying elements by magnetron sputtering co-deposition is proposed in this work to evaluate the effect of alloying element composition changes on the properties of non-equal molar ratio high-entropy alloys. The (TiVCr)x-(TaW)1-x binary system thin films were deposited by a magnetron sputtering system with two intermediate alloy targets. The surface morphology, element composition, roughness, and phase structure of the coatings were studied with scanning electron microscope (SEM), energy dispersive X-ray (EDX), X-ray diffractometer (XRD), atomic force microscope (AFM), and transmission electron microscope (TEM). The results show that at x = 0.51, the films had the best mechanical properties under the action of multiple strengthening mechanisms, and the hardness and modulus reached 27.61 GPa and 274.42 GPa, respectively. Due to higher hardness and special surface morphology, the films showed a lower average friction coefficient and had excellent wear resistance with wear rates of 0.34 and 5.01 × 10−9 mm3/(N·mm), respectively. On the other hand, it was found that forming a BCC polycrystalline structure and an amorphous-mixed structure can improve the radiation resistance of the material.
Microstructure Study on Large-Sized Ti–6Al–4V Bar Three-High Skew Rolling Based on Cellular Automaton Model
Authors: Hu Jianhua , Yang Sheng , Shuai Zhongfu , Wang Xiaohua , Xu Hongyan
Published: April 2022

The large diameter titanium alloy bars are usually manufactured by forging, which leads to large metal loss, high cost, low efficiency and limited product specifications. This paper adopted three-high skew rolling technology to roll Ti–6Al–4V bar with the diameter of 300 mm. With the reduction of 50 mm, the three-roll skew rolling model was developed by DEFORM-3D finite element software. A cellular automatic model (CA model) of large-sized titanium alloy bar cross-rolled was established, considering the effects of dislocation, recovery and nucleation on dynamic recrystallization. The microstructure evolution process is effectively simulated. During the process of rolling, dynamic recrystallization occurs in the outer layer of the rolled piece at first. The new nucleations form at the grain boundary, then grow into their secondary phase. With the rolling proceeding, the dynamic recrystallization gradually extends to the core of bar. The microstructure of the rolled bar is uniform and the grain size is refined with the average grain size of approximately 10 μm. The simulation results are compared with the experimental results, the actual grain size is a little coarser than that obtained by the CA model. Some reasons are given to reasonably explain the phenomenon.
Forming Mechanism of Weld Cross Section and Validating Thermal Analysis Results Based on the Maximal Temperature Field for Laser Welding
Authors: Rong Youmin , Xu Jiajun
Published: April 2022

In this paper, the forming mechanism of weld cross sections (WCSs) was studied via thermal analysis. The melting of a WCS was first dominated by heat convection from the flowing melt until the WCS had the max cross section in the transient temperature field. Then, the melting was dominated by heat conduction from the residual heat in the weld pool, giving rise to an increase in middle width but a decrease in upper and bottom width. This indicated that the WCS obtained from the transient temperature field could not represent the section after solidification. Therefore, thermal analysis results should be validated using the WCS obtained from the maximal temperature field. This WCS was dependent upon the max temperature of each node over time. Compared with the former WCS, the latter one showed better adaptability in terms of multi-process parameters when the thermal analysis results were validated.
Literature Review on the Fatigue Properties of Materials Processed by Surface Mechanical Attrition Treatment (SMAT)
Authors: Gao Pengfei , Sun Zhidan , Retraint Delphine
Published: April 2022

As a promising surface treatment technique, the surface mechanical attrition treatment (SMAT) has been applied to enhance mechanical properties of various materials. Through multidirectional severe plastic deformation, SMAT is able to nanocrystallize the near surface region of materials. The nanostructured layer associated with high compressive residual stresses coupled with a work hardening layer can provide the treated materials with an improved fatigue resistance. The present work gives a comprehensive review on the fatigue strength of SMATed materials. First of all, a brief introduction is given on the basic elements of SMAT and surface modifications induced by this treatment. The fatigue strength of a large variety of SMATed materials with different loading conditions is reviewed, including low-cycle fatigue (LCF), high-cycle fatigue (HCF) and very-high-cycle fatigue (VHCF). Then, the mechanism of enhancement or reduction is explained through a detailed review on the effects of several factors, such as residual stress, surface quality and nanocrystalline grains. In addition, the combined effect of SMAT coupled with other processes is also reviewed. Trends and prospects of the current research are summarized at the end.
Evaluation of Fracture Strain for Cold Drawn Thin-Walled Steel Tubes via Small Round-Bar Tensile Test
Authors: Matsuno Takashi , Matsuda Tomoko , Shoji Hiroto , Ohata Mitsuru
Published: April 2022

The evaluation of tube burring formability is a crucial task for finding a suitable material for tube-based automobile parts. The local strain at the ductile fracture site (fracture strain) should be evaluated for this purpose. Moreover, a cold-drawn steel tube has a strong anisotropic shaped microstructure and possibly causes anisotropic fracture strain behavior. Based on this background, the study evaluated the axial and hoop directional fracture strains of cold-drawn steel tubes using the small round-bar tensile specimen. The burnished surface ratio on the pierced surface was also investigated for possibility estimation of in-line formability inspection. As a result, three tubes are presented with inferior, nearly the same, and superior hoop directional fracture strains compared with the axial strains, where exceeding 40% deterioration in the hoop direction occurs by a combination of grain elongation and carbide aggregation. The scanning electron micrographs suggest that the microvoid growth and linkage percolated thorough carbides on the elongated grain boundaries. For the piercing test, the 30% fracture strain deterioration resulted in a 4% decrease in the burnished surface ratio on the pierced surface. This result suggested that the estimation of the pierced surface can detect material defects before the actual tube-burring process.
The Mechanism of In-Situ Laser Polishing and Its Effect on the Surface Quality of Nickel-Based Alloy Fabricated by Selective Laser Melting
Authors: Zhao Yanhua , Du Chuanbin , Wang Peifu , Meng Wei , Li Changming
Published: April 2022

Laser polishing (LP) is an effective method to improve the surface quality of an additively manufactured nickel-based alloy. In this paper, the in-situ laser polishing (ILP) experiment is performed on the selective laser melting (SLM) IN718 samples. The white light interferometer is used to test the three-dimensional surface profile and surface roughness of samples. The results show that the surface quality of as-SLMed samples by ILP is improved. In particular, the surface roughness is decreased by 33.5%. To reveal the mechanism of ILP, a three-dimensional numerical model is established based on the finite volume method (FVM). The model can accurately simulate the mesoscopic scale physical phenomena when the laser interacts with the metal. The temperature field, the melt pool flow, and the evolution of the surface morphology during the ILP process are predicted using this model. The mechanism of ILP is revealed based on the dynamics of the molten pool. The contribution of capillary and thermocapillary forces to the reduction of bulge curvature at different stages is studied. Furthermore, the effect of ILP power on the surface quality is investigated, and the mechanism of bulges and depressions on the track surface during high-power ILP is revealed.
Effects of Moderate–Intensity Physical Training on Skeletal Muscle Substrate Transporters and Metabolic Parameters of Ovariectomized Rats
Authors: Pejon Taciane Maria Melges , Scariot Pedro Paulo Menezes , Selistre-de-Araujo Heloísa Sobreiro , Gobatto Claudio Alexandre , Cornachione Anabelle Silva , Beck Wladimir Rafael
Published: April 2022

A deficit of estrogen is associated with energy substrate imbalance, raising the risk of metabolic diseases. Physical training (PT) is a potent metabolic regulator through oxidation and storage of substrates transported by GLUT4 and FAT CD36 in skeletal muscle. However, little is known about the effects of PT on these carriers in an estrogen-deficit scenario. Thus, the aim of this study was to determine the influence of 12 weeks of PT on metabolic variables and GLUT4 and FAT CD36 expression in the skeletal muscle of animals energetically impaired by ovariectomy (OVX). The trained animals swam 30 min/day, 5 days/week, at 80% of the critical load intensity. Spontaneous physical activity was measured biweekly. After training, FAT CD36 and GLUT4 expressions were quantified by immunofluorescence in the soleus, as well as muscular glycogen and triglyceride of the soleus, gluteus maximus and gastrocnemius. OVX significantly reduced FAT CD36, GLUT4 and spontaneous physical activity (p < 0.01), while PT significantly increased FAT CD36, GLUT4 and spontaneous physical activity (p < 0.01). PT increased soleus glycogen, and OVX decreased muscular triglyceride of gluteus maximus. Therefore, OVX can cause energy disarray through reduction in GLUT4 and FAT CD36 and their muscle substrates and PT prevented these metabolic consequences, masking ovarian estrogen’s absence.
Metabolomic Predictors of Dysglycemia in Two U.S. Youth Cohorts
Authors: Perng Wei , Hivert Marie-France , Michelotti Gregory , Oken Emily , Dabelea Dana
Published: April 2022

Here, we seek to identify metabolite predictors of dysglycemia in youth. In the discovery analysis among 391 youth in the Exploring Perinatal Outcomes among CHildren (EPOCH) cohort, we used reduced rank regression (RRR) to identify sex-specific metabolite predictors of impaired fasting glucose (IFG) and elevated fasting glucose (EFG: Q4 vs. Q1 fasting glucose) 6 years later and compared the predictive capacity of four models: Model 1: ethnicity, parental diabetes, in utero exposure to diabetes, and body mass index (BMI); Model 2: Model 1 covariates + baseline waist circumference, insulin, lipids, and Tanner stage; Model 3: Model 2 + baseline fasting glucose; Model 4: Model 3 + baseline metabolite concentrations. RRR identified 19 metabolite predictors of fasting glucose in boys and 14 metabolite predictors in girls. Most compounds were on lipid, amino acid, and carbohydrate metabolism pathways. In boys, no improvement in aurea under the receiver operating characteristics curve AUC occurred until the inclusion of metabolites in Model 4, which increased the AUC for prediction of IFG (7.1%) from 0.81 to 0.97 (p = 0.002). In girls, %IFG was too low for regression analysis (3.1%), but we found similar results for EFG. We replicated the results among 265 youth in the Project Viva cohort, focusing on EFG due to low %IFG, suggesting that the metabolite profiles identified herein have the potential to improve the prediction of glycemia in youth.
Thyroid Hormone Receptor Isoforms Alpha and Beta Play Convergent Roles in Muscle Physiology and Metabolic Regulation
Authors: Nappi Annarita , Murolo Melania , Cicatiello Annunziata Gaetana , Sagliocchi Serena , Di Cicco Emery , Raia Maddalena , Stornaiuolo Mariano , Dentice Monica , Miro Caterina
Published: April 2022

Skeletal muscle is a key energy-regulating organ, skilled in rapidly boosting the rate of energy production and substrate consumption following increased workload demand. The alteration of skeletal muscle metabolism is directly associated with numerous pathologies and disorders. Thyroid hormones (THs) and their receptors (TRs, namely, TRα and TRβ) exert pleiotropic functions in almost all cells and tissues. Skeletal muscle is a major THs-target tissue and alterations of THs levels have multiple influences on the latter. However, the biological role of THs and TRs in orchestrating metabolic pathways in skeletal muscle has only recently started to be addressed. The purpose of this paper is to investigate the muscle metabolic response to TRs abrogation, by using two different mouse models of global TRα- and TRβKO. In line with the clinical features of resistance to THs syndromes in humans, characterized by THRs gene mutations, both animal models of TRs deficiency exhibit developmental delay and mitochondrial dysfunctions. Moreover, using transcriptomic and metabolomic approaches, we found that the TRs–THs complex regulates the Fatty Acids (FAs)-binding protein GOT2, affecting FAs oxidation and transport in skeletal muscle. In conclusion, these results underline a new metabolic role of THs in governing muscle lipids distribution and metabolism.
A Flexible Tool to Correct Superimposed Mass Isotopologue Distributions in GC-APCI-MS Flux Experiments
Authors: Langenhan Jennifer , Jaeger Carsten , Baum Katharina , Simon Mareike , Lisec Jan
Published: April 2022

The investigation of metabolic fluxes and metabolite distributions within cells by means of tracer molecules is a valuable tool to unravel the complexity of biological systems. Technological advances in mass spectrometry (MS) technology such as atmospheric pressure chemical ionization (APCI) coupled with high resolution (HR), not only allows for highly sensitive analyses but also broadens the usefulness of tracer-based experiments, as interesting signals can be annotated de novo when not yet present in a compound library. However, several effects in the APCI ion source, i.e., fragmentation and rearrangement, lead to superimposed mass isotopologue distributions (MID) within the mass spectra, which need to be corrected during data evaluation as they will impair enrichment calculation otherwise. Here, we present and evaluate a novel software tool to automatically perform such corrections. We discuss the different effects, explain the implemented algorithm, and show its application on several experimental datasets. This adjustable tool is available as an R package from CRAN.
The Cause of Ribbon Fluctuation in Magnetorheological Finishing and Its Influence on Surface Mid-Spatial Frequency Error
Authors: Wang Bo , Shi Feng , Tie Guipeng , Zhang Wanli , Song Ci , Tian Ye , Shen Yongxiang
Published: April 2022

In the high-power laser system, the mid-spatial frequency error of the surface of the high-power laser component will affect the normal operation of the high-power laser system. In order to improve the mid-spatial frequency error of the high-power laser component after magnetorheological finishing, the causes and influencing factors of the ribbon fluctuation in magnetorheological finishing are studied, and the influence of different ribbon fluctuation on the mid-spatial frequency error of the surface is studied. Firstly, the influence of different ribbon fluctuations on the mid-spatial frequency error of the machined surface is simulated by a computer. Secondly, the magnetic field in the circumferential direction of the polishing wheel, the fluctuation amount and frequency of the magnetorheological polishing ribbon are measured, and then the causes of the fluctuation of the magnetorheological polishing ribbon are analyzed. Moreover, through the principle of a single variable, the influence of process parameters on the fluctuation of magnetorheological polishing ribbon is explored. Finally, the fused silica component is scanned uniformly under the process parameters of magnetorheological polishing ribbon fluctuation of 40 μm, 80 μm, 150 μm, and 200 μm. The experimental results show that the greater the ribbon fluctuation, the greater the surface mid-spatial frequency error of the component, and the ribbon fluctuation is approximately linear with the RMS of the PSD2 in the mid-spatial frequency band on the surface of the component. Therefore, the fluctuation of the ribbon can be controlled by controlling the magnetorheological processing parameters, and the mid-spatial frequency band error on the surface of the high-power laser component can be significantly reduced by optimizing process parameters after magnetorheological finishing.
Microstructure and Wear of W-Particle-Reinforced Al Alloys Prepared by Laser Melt Injection
Authors: Xu Zhidong , Wang Dengzhi , Song Wenji , Tang Congwen , Sun Pengfei , Yang Jiaxing , Hu Qianwu , Zeng Xiaoyan
Published: April 2022

W-particle-reinforced Al alloys were prepared on a 7075 aluminum alloy surface via laser melt injection to improve their wear resistance, and the microstructure, microhardness, and wear resistance of the W/Al layers were studied. Scanning electron microscopy (SEM) results confirmed that a W/Al laser melting layer of about 1.5 mm thickness contained W particles, and Al4W was formed on the surface of the Al alloys. Due to the reinforcement of the W particles and good bonding of the W and Al matrix, the melting layer showed excellent wear resistance compared to that of Al alloys.
Flux Pinning Properties of Single-Grain Bulk GdBCO Superconductors Processed by Different Thicknesses of Y123 Liquid Source
Authors: Zhang Yufeng , Lou Ziwei , Zhang Penghe , Li Chunyan , Zhang Jiaying , Zhang Xiaojuan
Published: April 2022

The performance of critical current density of GdBa2Cu3O7−δ (GdBCO or Gd123) superconductor bulk has an important influence on its practical applications. In this work, four single-domain GdBCO superconductor bulks were successfully processed by the modified top-seeded melt-texture growth method. The addition of a YBa2Cu3O7−δ (Y123) liquid source with different thicknesses, 0 mm (S0), 3 mm (S3), 5 mm (S5), 7 mm (S7), was introduced to study the influence on the superconducting properties. GdBCO bulk with the addition of the Y123 liquid source with a 3-mm thickness shows the best superconducting properties. The addition of the Y123 liquid source results in a decrease in the Gd3+ ion concentration required for Gd123 growth; thus, Gd2BaCuO5 (Gd211) particles in the liquid source need a larger self-decomposition to diffuse Gd3+ ions to Gd123 growth front, which refines the size and leads to a homogenous distribution of the Gd211 particles in the bulks. Thus, the more pinning centers of fined Gd211 particles improve the superconducting properties of GdBCO bulk. With increases in the thickness of Y123 liquid source to 5 mm and 7 mm, high RE3+ (Gd3+ and Y3+) concentration can coarsen Gd211 particles and fuse with Gd211 liquid source. The superconducting properties apparently drop. Therefore, the addition of a Y123 liquid source with a suitable thickness is a positive modification to obtain high-performance GdBCO bulk.
Electrochemical Deposition of Pure-Nickel Microstructures with Controllable Size
Authors: Bi Xiaolei , Meng Lingchao
Published: April 2022

Pure nickel microstructures have been widely used in MEMS and have great application potential as a sacrificial mandrel for fabricating terahertz micro-cavity components. The performance of MEMS and terahertz micro-cavity components can be significantly improved through the use of high-quality pure nickel microstructures. Up to now, microfabrication techniques, such as laser micromachining, wire electrical-discharge machining, and cold-spray additive manufacturing, have been used to machine various types of such microstructures. However, huge challenges are involved in using these micromachining techniques to fabricate pure-nickel microstructures with controllable size and good dimensional accuracy, surface roughness, and edge radius. In this paper, taking the example of a pure-nickel rectangular mandrel that corresponds to the size of the end face of a 1.7-THz rectangular waveguide cavity, the machining processes for the electrochemical deposition of pure-nickel microstructures with controllable size, high dimensional accuracy, and good surface roughness and edge radius are discussed systematically. This proposed method can be used to manufacture various types of high-quality pure-nickel microstructures.
Variable Range Hopping Model Based on Gaussian Disordered Organic Semiconductor for Seebeck Effect in Thermoelectric Device
Authors: Zhao Ying , Wang Jiawei
Published: April 2022

We investigate the carrier concentration dependent Seebeck coefficient in Gaussian disordered organic semiconductors (GD-OSs) for thermoelectric device applications. Based on the variable-range hopping (VRH) theory, a general model predicting the Seebeck effect is developed to reveal the thermoelectric properties in GD-OSs. The proposed model could interpret the experimental data on carrier concentration- and temperature-dependence of the Seebeck coefficient, including various kinds of conducting polymer film and small molecule based field-effect transistors (FETs). Compared with the conventional Mott’s VRH and mobility edge model, our model has a much better description of the relationship between the Seebeck coefficient and conductivity. The model could deepen our insight into charge transport in organic semiconductors and provide instructions for the optimization of thermoelectric device performance in a disordered system.
Microstructure and Corrosion Behavior of Iron Based Biocomposites Prepared by Laser Additive Manufacturing
Authors: Zhou Yan , Xu Lifeng , Yang Youwen , Wang Jingwen , Wang Dongsheng , Shen Lida
Published: April 2022

Iron (Fe) has attracted great attention as bone repair material owing to its favorable biocompatibility and mechanical properties. However, it degrades too slowly since the corrosion product layer prohibits the contact between the Fe matrix and body fluid. In this work, zinc sulfide (ZnS) was introduced into Fe bone implant manufactured using laser additive manufacturing technique. The incorporated ZnS underwent a disproportionation reaction and formed S-containing species, which was able to change the film properties including the semiconductivity, doping concentration, and film dissolution. As a result, it promoted the collapse of the passive film and accelerated the degradation rate of Fe matrix. Immersion tests proved that the Fe matrix experienced severe pitting corrosion with heavy corrosion product. Besides, the in vitro cell testing showed that Fe/ZnS possessed acceptable cell viabilities. This work indicated that Fe/ZnS biocomposite acted as a promising candidate for bone repair material.
Partitioning of Small Hydrophobic Molecules into Polydimethylsiloxane in Microfluidic Analytical Devices
Authors: Rodrigues Patrícia M. , Xavier Miguel , Calero Victor , Pastrana Lorenzo , Gonçalves Catarina
Published: April 2022

Polydimethylsiloxane (PDMS) is ubiquitously used in microfluidics. However, PDMS is porous and hydrophobic, potentially leading to small molecule partitioning. Although many studies addressed this issue and suggested surface/bulk modifications to overcome it, most were not quantitative, did not address which variables besides hydrophobicity governed molecule absorption, and no modification has been shown to completely obviate it. We evaluated qualitatively (confocal microscopy) and quantitatively (fluorescence spectroscopy) the effects of solute/solvent pairings, concentration, and residence time on molecule partitioning into PDMS. Additionally, we tested previously reported surface/bulk modifications, aiming to determine whether reduced PDMS hydrophobicity was stable and hindered molecule partitioning. Partitioning was more significant at lower concentrations, with the relative concentration of rhodamine-B at 20 µM remaining around 90% vs. 10% at 1 µM. Solute/solvent pairings were demonstrated to be determinant by the dramatically higher partitioning of Nile-red in a PBS-based solvent as opposed to ethanol. A paraffin coating slightly decreased the partitioning of Nile-red, and a sol–gel modification hindered the rhodamine-B diffusion into the PDMS bulk. However, there was no direct correlation between reduced surface hydrophobicity and molecule partitioning. This work highlighted the need for pre-assessing the absorption of test molecules into the microfluidic substrates and considering alternative materials for fabrication.
Vanadium Dioxide-Based Terahertz Metamaterial Devices Switchable between Transmission and Absorption
Authors: Jiang Haoqing , Wang Yue , Cui Zijian , Zhang Xiaoju , Zhu Yongqiang , Zhang Kuang
Published: April 2022

Terahertz metamaterial plays a significant role in the development of imaging, sensing, and communications. The function of conventional terahertz metamaterials was fixed after fabrication. They can only achieve a single function and do not have adjustable characteristics, which greatly limits the scalability and practical application of metamaterial. Here, we propose a vanadium dioxide-based terahertz metamaterial device, which is switchable between being a transmitter and an absorber. The transmission and absorption characteristics and temperature tunable properties of phase change metamaterials in the terahertz band were investigated. As the temperature of vanadium dioxide is varied between 20 °C and 80 °C, the device can switch between transmission and quad-band resonance absorption at the terahertz frequency range, with a high transmission rate of over 80% and a peak absorbance of 98.3%, respectively. In addition, when the device acts as an absorber, the proposed metamaterial device is tunable, and the modulation amplitude can reach 94.3%; while the device is used as a transmissive device, the modulation amplitude of the transmission peak at 81%. The results indicate that the proposed metamaterial device can promote the applications of terahertz devices, such as switching, modulation, and sensing.
Lane-GAN: A Robust Lane Detection Network for Driver Assistance System in High Speed and Complex Road Conditions
Authors: Liu Yan , Wang Jingwen , Li Yujie , Li Canlin , Zhang Weizheng
Published: April 2022

Lane detection is an important and challenging part of autonomous driver assistance systems and other advanced assistance systems. The presence of road potholes and obstacles, complex road environments (illumination, occlusion, etc.) are ubiquitous, will cause the blur of images, which is captured by the vision perception system in the lane detection task. To improve the lane detection accuracy of blurred images, a network (Lane-GAN) for lane line detection is proposed in the paper, which is robust to blurred images. First, real and complex blur kernels are simulated to construct a blurred image dataset, and the improved GAN network is used to reinforce the lane features of the blurred image, and finally the feature information is further enriched with a recurrent feature transfer aggregator. Extensive experimental results demonstrate that the proposed network can get robust detection results in complex environments, especially for blurred lane lines. Compared with the SOTA detector, the proposed detector achieves a larger gain. The proposed method can enhance the lane detail features of the blurred image, improving the detection accuracy of the blurred lane effectively, in the driver assistance system in high speed and complex road conditions.