Search

A novel calcium carbonate (CaCO3)/expanded graphite (EG) catalyst was fabricated, characterized, and used in a catalytic ozonation process to increase degradation and mineralization of ethylenediaminetetraacetic acid (EDTA) aqueous solutions. Various techniques were used to analyze the crystalline structure, morphology, and elemental composition of the novel CaCO3/EG catalyst, including X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. Mercury intrusion porosimetry was used to measure specific surface area, pore diameter, and pore volume of the CaCO3/EG catalyst. Essential influencing factors such as CaCO3/EG composite dosage and initial pH were also surveyed for different systems. Catalytic ozonation by CaCO3/EG was notably increased by the removal of total organic carbon (TOC) of EDTA. After 60 min, 80% TOC removal efficiency from simulated wastewater having an initial TOC concentration of 600 mg/L and initial pH of 4.9 was achieved using 1.0 g/L CaCO3/EG. This efficiency was higher than that seen for other systems, including O3 alone (40%), EG/O3 (39%), CaCO3/O3 (28%), and EG (4%). A small decrease in the CaCO3/EG-catalyzed TOC removal rate was observed after three runs, but nonetheless the efficiency was >80% after 120 min. Assays with tert-butanol confirmed that CaCO3/EG-mediated catalytic ozonation was dependent on a free radical pathway. The results support that CaCO3/EG material could serve as an important reusable resource for catalytic oxidation reactions during treatment of wastewater containing EDTA. [ABSTRACT FROM AUTHOR]

Commercial Ni-YSZ anodes of solid oxide fuel cells (SOFCs) are susceptible to carbon deposits using hydrocarbons as fuel. Herein, we explore a simple approach of low fuel partial pressure to investigate the relevant limiting factors for ethanol-fueled SOFCs, providing the evaluation of the electrochemical performance and the carbon tolerance. As the partial pressure of ethanol fuel increases from 30% to 60%, the best cell performance gradually increases from 710.2 mW cm−2 to 856.8 mW cm−2 at 800 °C, which still lower than those of hydrogen-fueled SOFCs (1061.4 mW cm−2 at 800 °C), and the corresponding improvement in concentration polarization can be clearly observed especially in high current discharge area. The corresponding impedance spectra and electrode polarization processes of ethanol-fueled SOFCs are further studied by the equivalent circuit fitting and the distribution function of relaxation time (DRT) analysis, finding that the key improvement of the speed control steps comes from the concentration polarization process with the increase of the fuel partial pressure. Small amount of carbon deposition is observed on the Ni-YSZ anode substrate by SEM-EDS images after short-term discharging testing, and the safety utilization boundaries of ethanol-fueled SOFCs with a certain steam concentration can be predicted by the thermodynamic equilibria calculation. • Ethanol-fueled SOFCs with low fuel partial pressure are evaluated. • Low fuel partial pressure leads to the cell concentration polarization. • Electrode polarization processes are studied by the DRT analysis. • Safety utilization boundaries can be predicted by the thermodynamic equilibria calculation. [ABSTRACT FROM AUTHOR]

• Considering the spatial–temporal correlation of random matrices, a system operating state analysis method based on the single-ring theorem and correlation coefficient analysis is proposed to provide the basis for low-quality PMU data identification to determine the reasons for PMU data mutations. • Starting from singular value decomposition and reconstruction, a low-quality PMU data identification method based on the spatial–temporal correlation between original data and low-rank reconstructed data is proposed under different operating states. • The physical meanings of singular value decomposition are analyzed, and a dynamic threshold selection method is adopted for low-quality PMU data identification criteria based on the spatial–temporal correlation to improve the identification accuracy. With the high access of renewable energy, complex and changeable transmission networks, and frequent load interactions, the dynamic characteristics of low-carbon power systems have become more complex and random. The 10 ms-level dynamic measurement data of Phasor Measurement Unit are the basis for dynamic awareness, control and decision. However, the phenomenon of low-quality data usually exists in PMU measurements. Considering the spatial–temporal correlation reflected by the random matrix single-ring theorem and correlation coefficients, two system operating states and two types of low-quality PMU data are determined. Based on singular value decomposition and reconstruction, the distribution of the residuals between the original data and reconstructed data is analyzed to realize low-quality PMU data identification. To improve the identification accuracy, a dynamic threshold selection method of spatial–temporal correlation analysis is proposed for identification criteria. The feasibility and applicability of this method has been verified in the simulation data of IEEE 39 bus system and PMU measured data of the practical power grid. [ABSTRACT FROM AUTHOR]

• The data quality of field PMU measurements is analyzed, the results of which indicate the necessity of data improvement for measurement based potential applications. • A robust state estimation method is adopted to improve the data quality of field PMU measurements for ambient signal based load model parameter identification. • Two scenarios, i.e., data recovery and data correction are considered for the effectiveness verification of the state estimation method for data improvement. • Case studies with not only simulation data from power system analysis toolbox, but also the field PMU measurements from China southern power grid, demonstrate the effectiveness of the state estimation method on data improvement for ambient signal based load model parameter identification. Considering the component based modeling approach's shortage of requiring the typical load model parameters and the traditional measurement based modeling approach's inadequacy of the dependence on fault-disturbance data, the recently proposed ambient signal based load modeling approach offers an important idea to track the time-varying characteristics of power loads. However, it suffers the impacts of phasor measurement unit (PMU) measurement errors. Consequently, data improvement for ambient signal based load modeling is both important and necessary. In this paper, state estimation is adopted to make the ambient signal based method usable with field PMU measurements. To be specific, a weighted least square method is applied for state estimation to improve the data quality. On this basis, the improved data are used for load model parameter identification to evaluate the performance of the state estimation method from the perspective of data application. Case studies with both simulation data from power system analysis toolbox and field PMU measurements from China southern power grid have verified the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

We intended to discuss the influence of histone deacetylase 3 (HDAC3) on spinal cord injury (SCI) by regulating microRNA-19b-1-5p (miR-19b-1-5p) and janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway. In a rat model, the role of HDAC3 and miR-19b-1-5p in SCI was identified through detecting motor function, serum inflammation, pathological damage, cell apoptosis and GFAP expression. Also, by measuring GFAP expression and migration of spinal cord astrocytes, the effects of HDAC3 and miR-19b-1-5p in SCI were identified in vitro. Restoration of miR-19b-1-5p or depletion of HDAC3 alleviated motor function, inflammation, relieved pathological damage and reduced apoptosis, and reduced GFAP expression in the spinal cord tissue of SCI rats. Up-regulating miR-19b-1-5p or down-regulating HDAC3 decreased migration and GFAP expression of injured astrocytes. Our study presents that down-regulated HDAC3 can facilitate the recovery of SCI via inhibiting the activation of JAK2/STAT3 pathway by up-regulating miR-19b-1-5p. • Decreased miR-19b-1-5p and increased HDAC3 are found in SCI. • HDAC3 specially binds to miR-19b-1-5p. • Raised miR-19b-1-5p/reduced HDAC3 promote SCI recovery of SCI rats. • Raised miR-19b-1-5p/reduced HDAC3 inhibit apoptosis of astrocytes. • HDAC3 may be a potential candidate for treatment of SCI. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the design procedures and the construction process of a glass fiber reinforced polymer (GFRP) corrugated-core sandwich bridge superstructure. This all-GFRP bridge superstructure was installed in Korea. Based on field load testing and finite element analysis, the effectiveness of the proposed system was demonstrated. The paper also discussed connection details as well as the dynamic effects on the FRP sandwich superstructure due to truck live load. Finally this paper illustrated the time, labor, and cost invested in the project and explained why bridges with FRP superstructures can be economically competitive in the future. [ABSTRACT FROM AUTHOR]

Background. The association between heart failure (HF) and cognitive impairment has received increasing attention from scholars and researchers in recent years. However, no systematic studies have been carried out yet focused on the crosstalk between heart failure and cognitive impairment via miRNAs. Methods. GSE104150, GSE53473, GSE120584, and GSE116250 with RNA-seq data and clinical data were downloaded from the GSE database. All data were statistically analysed using R software to detect DE-miRNAs and DE-mRNAs associated with both HF and cognitive impairment. Protein-protein interaction (PPI) networks were mapped, and a logistic regression model for cognitive impairment prediction was developed. Furthermore, the TTRUST database and miRWalk were used to map miRNA-transcription factor (TF) and messenger RNA (mRNA) regulatory pathways. Finally, core TFs were enriched for analysis. Results. Differentially enriched DE-miRNAs and DE-mRNAs both present in HF and cognitive impairment were determined. A logistic regression model established based on DE-miRNAs was validated to have a strong performance in cognitive impairment prediction. The core miRNA-TF-mRNA pathway was formed by mapping the PPI networks associated with the two diseases. Further GSEA was performed with V-rel reticuloendotheliosis viral oncogene homolog B (RELB) as the core TF, and the retinol metabolism and gap junction pathways were analysed. Conclusions. This study was the first attempt to predict the crosstalk and examine underlying mechanisms between HF and cognitive impairment applying bioinformatics. The findings suggested a potential hsa-miR-933/RELB/CCL21 regulatory axis correlated with HF and neurological disorders (or cognitive impairment), according to PPI networks. [ABSTRACT FROM AUTHOR]

This paper presents a design to realize extremely low cross‐polarization level in multibeam antenna. The antenna consists of two reflectors placed on top of each other. The front reflector is a panel made of metal grid, which is used to separate two orthogonal polarizations. The rear reflector serves as the actual multibeam antenna surface. The multibeam antenna and feed array operated at Ku band are designed and fabricated. The test results show that the gains of the 28 beams can be better than 40.42 dBi, and the cross‐polarization level can be lower than −40 dB. The proposed method provides a novel idea for the design of ultralow cross‐polarization multibeam antenna. [ABSTRACT FROM AUTHOR]

Electrocardiogram (ECG) indicates the occurrence of various cardiac diseases, and the accurate classification of ECG signals is important for the automatic diagnosis of arrhythmia. This paper presents a novel classification method based on multiple features by combining waveform morphology and frequency domain statistical analysis, which offer improved classification accuracy and minimise the time spent for classifying signals. A wavelet packet is used to decompose a denoised ECG signal, and the singular value, maximum value, and standard deviation of the decomposed wavelet packet coefficients are calculated to obtain the frequency domain feature space. The slope threshold method is applied to detect R peak and calculate RR intervals, and the first two RR intervals are extracted as time-domain features. The fusion feature space is composed of time and frequency domain features. A combination of support vector machine (SVM) with the help of grid search and waveform morphological analysis is applied to complete nine types of ECG signal classification. Computer simulations show that the accuracy of the proposed algorithm on multiple types of arrhythmia databases can reach 96.67%. [ABSTRACT FROM AUTHOR]

A redox-stable perovskite oxide Sm 0.5 Sr 0.5 FeO 3-δ (SSF) at reduced temperatures is investigated as a new promising electrode material for symmetric solid oxide fuel cells (SSOFCs). SSF exhibits well structural stability and catalytic activity in redox atmosphere at intermediate temperatures (≤750 °C), and the electrical conductivity exhibits a semiconductor behavior both in cathode and anode atmosphere. To enhance the electrochemical performance of SSF by adding oxygen-ion conductor Gd 0.1 Ce 0.9 O 2-δ (GDC), the electrode polarization resistances at 750 °C are reduced from 2.86 to 0.67 Ω cm2 in air and from 4.32 to 0.91 Ω cm2 in humidified H 2 , respectively. Accordingly, the cell performance of SSOFCs with SSF-GDC composite electrode is almost twice (201.74 mW cm−2 at 750 °C) of those with the single-phase one. There preliminary experimental results demonstrate SSF-based electrode materials can be new promising candidates for SSOFCs at low temperatures. [ABSTRACT FROM AUTHOR]

Highly active triple-conducting (proton-, oxygen-ion-, and electron-conducting) perovskite oxide BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3- δ need to further optimize the electrochemical performance and chemical stability in carbon dioxide and water containing atmospheres, greatly limiting its widespread use in protonic ceramics fuel cells (PCFCs). Here, Ba-site deficient Ba 0.9 Co 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3- δ (B9CFZY) was synthesized and investigated as a promising candidate concerning the chemical and structural stability, electrical conductivity and electrochemical performance. Anode-supported button cells with the prevalent BaZr 0.1 Ce 0.7 Y 0.2 O 3- δ (BZCY) as electrolyte using B9CFZY and B9CFZY-BZCY cathodes, respectively, were fabricated and then measured at 700-550 °C. The maximum power density of the cells with B9CFZY-based cathodes increase from 452 mW cm−2 to 537 mW cm−2 at 700 °C, however, the corresponding polarization loss decreases from 0.30 to 0.15 Ω cm2 by adding proton-conducting BZCY. Importantly, to better explore the reasons for the improved electrochemical performance, the distribution function of relaxation time (DRT) is used to distinguish different electrode polarization processes of both cells. The results indicate the polarization peaks (P3) of cells with composite cathode resulting from oxygen gas adsorption and dissociation can be greatly accelerated as well as the polarization peaks (P2) resulting from oxygen species diffusion to three phase boundaries or active sites in the cathode. The dramatic improvements demonstrate Ba deficient B9CFZY-BZCY material can be a very competitive cathode material for PCFCs. [ABSTRACT FROM AUTHOR]

This study presents two meso-mechanical methods of analyzing the asphalt concrete’s dynamic modulus, including the transient dynamic method (implicit dynamic method) based on the modified Newmark numerical differential algorithm and the steady-state dynamic method based on the perturbation theory. The results indicate that compared to the transient dynamic method based on the modified Newmark numerical differential algorithm, the steady-state dynamic method based on the perturbation theory is much more efficient in calculating dynamic modulus of asphalt concrete while maintaining similar accuracy. Furthermore, the random aggregate model of asphalt concrete coupled with the steady-state dynamic method is also employed to obtain the asphalt concrete’s dynamic modulus. The numerical solution was found in a good agreement with the corresponding experiment results, which indicates the proposed steady-state dynamic method an efficient and effective way to predict the dynamic modulus of asphalt concrete. [ABSTRACT FROM AUTHOR]

Pentraxin 3 (PTX3), a soluble pattern recognition receptor, plays an important role in innate immunity and has been implicated to be a candidate resistance gene against Streptococcus suis 2 infection. To discover the antibacterial effect of porcine PTX3 against S. suis 2, the 42-kDa PTX3 protein was expressed by Chinese hamster ovary cells (CHO), and an additional eukaryotic expression vector pVAX- ptx3 was constructed. The expressed porcine PTX3 mediated a range of antibacterial activities including increasing phagocytic capacity of primary porcine alveolar macrophages (PAM) against S. suis 2 and inhibiting adhesion of S. suis 2 to human epidermoid cancer cells (Hep-2). In mouse model, pre-intramuscular injecting with pVAX- ptx3 reduced mortality and reduced bacteria loads in blood, spleen, lung and brain compared with that of control group during 2–12 h following intraperitoneal injection ( i.p. ) with S. suis 2. Meanwhile, the expressions of IL-6 and IL-8 in blood were increased in pVAX- ptx3 group, whereas no obvious changes about IL-10. In piglet model, bacteria load in blood of pVAX- ptx3 group was significantly lower than that of control group after i.p. with S. suis 2, correspondingly, expression of IL-6 and IL-8 were significantly increased in pVAX- ptx3 group. In contrast, white blood cell (WBC) and neutrophil cell (NEU) count of peripheral blood in pVAX- ptx3 group were lower than that of control group. These studies described a novel antibacterial role for porcine PTX3 against S. suis 2 both in vitro and in vivo and suggested that porcine PTX3 may be a potential biological agent against S. suis 2 in pig and be used for the clinical prevention and treatment of streptococcosis caused by S. suis 2. [ABSTRACT FROM AUTHOR]

Heart disease is the leading cause of death for men and women globally. The residual network (ResNet) evolution of electrocardiogram (ECG) technology has contributed to our understanding of cardiac physiology. We propose an artificial intelligence-enabled ECG algorithm based on an improved ResNet for a wearable ECG. The system hardware consists of a wearable ECG with conductive fabric electrodes, a wireless ECG acquisition module, a mobile terminal App, and a cloud diagnostic platform. The algorithm adopted in this study is based on an improved ResNet for the rapid classification of different types of arrhythmia. First, we visualize ECG data and convert one-dimensional ECG signals into two-dimensional images using Gramian angular fields. Then, we improve the ResNet-50 network model, add multistage shortcut branches to the network, and optimize the residual block. The ReLu activation function is replaced by a scaled exponential linear units (SELUs) activation function to improve the expression ability of the model. Finally, the images are input into the improved ResNet network for classification. The average recognition rate of this classification algorithm against seven types of arrhythmia signals (atrial fibrillation, atrial premature beat, ventricular premature beat, normal beat, ventricular tachycardia, atrial tachycardia, and sinus bradycardia) is 98.3%. [ABSTRACT FROM AUTHOR]

In view of the high catalytic activity, enhanced oxygen-ion transport and good stability, the self-assembled hybrid electrocatalyst can be used for symmetrical and reversible solid oxide cells (RSOCs). Herein, a new Ni-free ceramic fuel electrode can be obtained by in situ annealing the orthorhombic perovskite Pr 0.6 Sr 0.4 FeO 3-δ (PSF) in H 2 at 850 °C for 2 h, consisting of orthorhombic perovskite matrix with nano Ruddlesden–Popper oxide (RP/O-PSF). Symmetrical RSOCs consisting of RP/O-PSF fuel electrode, La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3-δ (LSGM) electrolyte and PSF air electrode (PSF|LSGM|PSF) were fabricated and the electrochemical performance was evaluated. The maximum power density of the cell under solid oxide fuel cell (SOFC) mode is 591 mW/cm2 at 800 °C, and the current density of the cell under solid oxide electrolysis cell (SOEC) mode is -1388 mA/cm2 at 800 °C with an applied electrolysis voltage of 1.6 V. The polarization resistances of cell under SOFC mode and SOEC mode are 0.152 Ω cm2 (OCV-0.2 V) and 0.126 Ω cm2 (OCV + 0.2 V), respectively, demonstrating an excellent catalytic activity of RP/O-PSF towards the water electrolysis process compared with hydrogen oxidation reaction (HOR) owing to the accelerated transfer rate of oxygen ions. In addition, the desirable long-term stability indicates the fact that RP/O-PSF hybrid electrode is such a suitable and prospective candidate for symmetrical and reversible solid oxide cells. [ABSTRACT FROM AUTHOR]

As a promising electrocatalyst for hydrogen evolution reaction (HER), molybdenum disulfide (MoS 2) owns inadequate edge active sites and inferior conductivity which restricts its effective application. In this study, the expanded graphite matrix (EGM) cathode was fabricated by tableting worm-like expanded graphite (EG), acetylene black and poly tetra fluoroethylene (PTFE) emulsion, and MoS 2 grew on EGM via a hydrothermal synthesis process, subsequently employed for the HER process. Benefiting from the superior conductivity and sufficient exposure of edge active sites on the rough structure of EGM, MoS 2 /EGM exhibits a small overpotential of 230 mV (j = 10 mA cm−2), a low Tafel slope of 77 mV·dec−1 and a lower value of charge transfer resistance (R ct , 0.919 Ω cm2). The improvement of HER performance of MoS 2 /EGM could be due to the participation of the EGM as a highly conductive substrate. Excellent electrochemical durability of MoS 2 /EGM was attested by the cyclic voltammetry and the amperometric (i − t) measurements. This work may have the potential to develop a promising path to design advanced electrode materials for HER. • MoS 2 /EGM cathode composites were easily synthesized by a hydrothermal method. • The MoS 2 /EGM catalyst shows an excellent HER performance. • MoS 2 and EGM have a synergistic effect in HER at the full pH environments. • The superior HER property of MoS2/EGM is due to conductivity of EGM and uniform growth of MoS2. [ABSTRACT FROM AUTHOR]

Cathode materials containing proton conductivity for protonic ceramics fuel cells (PCFCs) can increase the three phase boundary length of the air/cathode/electrolyte, and thus increase the reaction rate of proton with oxygen-species to form water in cathode side. In this work, a serious of Fe-substituted in BaZr 0.8 Y 0.2 O 3-δ proton conducting oxides, abbreviated as BaZr 0.8-x Fe x Y 0.2 O 3-δ (BZFY-2, BZFY-4, BZFY-6, BZFY-8), were synthesized and investigated as cathode materials for PCFCs, considering the phase structure, mean valence state and electrochemical performance. Accordingly, anode supported button cells using BaZr 0.8-x Fe x Y 0.2 O 3-δ as cathodes are fabricated, and then performed from 700 to 550 °C. The cell performance with BZFY-6 presents optimal electrochemical performance with different Fe doping amount, and the peak power density of 322.23 mW cm−2 and the corresponding polarization resistance of 0.28 Ω cm2 are observed at 700 °C. Moreover, the corresponding electrode polarization processes are further studied by the distribution function of relaxation time (DRT) analysis, and three peaks of P1, P2 and P3 in DRT curves correspond the proton bulk diffusion, electrochemical reaction processes, and adsorption as well as diffusion process of oxygen, respectively. Preliminary results demonstrate that BZFY-6 can be a competitive promising for PCFCs. • Iron is doped to BaZr 0.8 Y 0.2 O 3-δ to produce new proton conducting oxides. • The lattice parameters of BaZr 0.8-x Fe x Y 0.2 O 3-δ decrease after Fe doping. • Electrode polarization processes are studied by DRT analysis. • BZFY-6 can be a competitive promising for protonic ceramics fuel cells. [ABSTRACT FROM AUTHOR]

Cancer immunotherapy relies upon the ability of T cells to infiltrate tumors. The endothelium constitutes a barrier between the tumor and effector T cells, and the ability to manipulate local vascular permeability could be translated into effective immunotherapy. Here, we show that in the context of adoptive T cell therapy, antitumor T cells, delivered at high enough doses, can overcome the endothelial barrier and infiltrate tumors, a process that requires local production of C3, complement activation on tumor endothelium and release of C5a. C5a, in turn, acts on endothelial cells promoting the upregulation of adhesion molecules and T-cell homing. Genetic deletion of C3 or the C5a receptor 1 (C5aR1), and pharmacological blockade of C5aR1, impaired the ability of T cells to overcome the endothelial barrier, infiltrate tumors, and control tumor progressionin vivo, while genetic chimera mice demonstrated that C3 and C5aR1 expression by tumor stroma, and not leukocytes, governs T cell homing, acting on the local endothelium.In vitro, endothelial C3 and C5a expressions were required for endothelial activation by type 1 cytokines. Our data indicate that effective immunotherapy is a consequence of successful homing of T cells in response to local complement activation, which disrupts the tumor endothelial barrier. [ABSTRACT FROM PUBLISHER]