Numerical Simulation for Synergetic Deformation of Optical Fiber Sensor and Asphalt Mixture

Xiang-fei Zhang,Zhen-dong Qian,Meng Zhang,Lei-lei Chen 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.7

Owing to the structural and material differences, data obtained by distributed optical fiber sensors (OFS) for asphalt pavement strain measurement lack of precision. For better understanding OFS measurement mechanism and investigating the measurement error correction, this study analyzed the synergetic deformation of OFS and asphalt mixture (AM) under load. Firstly, a threedimensional AM single-edge notched beam (SEB) model with OFS was established and verified using the discrete element method. Secondly, the micro-crack propagation of SEB model during loading procedure was analyzed to explore the debonding behavior between OFS and AM. Thirdly, strain development of OFS and AM was investigated during fracture stage and post-fracture stage. Finally, a measurement error correction method was developed based upon the materials and test conditions in this study. Results demonstrate that debonding occurs on OFS surface when macro-crack extends across OFS position. The key to making the strain measurement accuracy is to ensure the effective bonding between OFS and AM. In addition, this study provides a framework used to develop the measurement error correction, and the research results give the theoretical foundation for data selection and error correction of asphalt pavement strain measurement and crack detection using distributed optical fiber sensors.

Identification of novel rheumatoid arthritis-associated MiRNA-204-5p from plasma exosomes

Wu Long-Fei,Zhang Qin,Mo Xing-Bo,Lin Jun,Wu Yang-Lin,Lu Xin,He Pei,Wu Jian,Guo Yu-Fan,Wang Ming-Jun,Ren Wen-Yan,Deng Hong-Wen,Lei Shu-Feng,Deng Fei-Yan 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Rheumatoid arthritis (RA) is an autoimmune disease characterized by infiltration of immune cells in the synovium. However, the crosstalk of immune cells and synovial fibroblasts is still largely unknown. Here, global miRNA screening in plasma exosomes was carried out with a custom microarray (RA patients vs. healthy controls = 9:9). A total of 14 exosomal miRNAs were abnormally expressed in the RA patients. Then, downregulated expression of exosomal miR-204-5p was confirmed in both the replication (RA patients vs. healthy controls = 30:30) and validation groups (RA patients vs. healthy controls = 56:60). Similar to the findings obtained in humans, a decreased abundance of exosomal miR-204-5p was observed in mice with collagen-induced arthritis (CIA). Furthermore, Spearman correlation analysis indicated that plasma exosomal miR-204-5p expression was inversely correlated with disease parameters of RA patients, such as rheumatoid factor, erythrocyte sedimentation rate, and C-reactive protein. In vitro, our data showed that human T lymphocytes released exosomes containing large amounts of miR-204-5p, which can be transferred into synovial fibroblasts, inhibiting cell proliferation. Overexpression of miR-204-5p in synovial fibroblasts suppressed synovial fibroblast activation by targeting genes related to cell proliferation and invasion. In vivo assays found that administration of lentiviruses expressing miR-204-5p markedly alleviated the disease progression of the mice with CIA. Collectively, this study identified a novel RA-associated plasma exosomal miRNA-204-5p that mediates the communication between immune cells and synovial fibroblasts and can be used as a potential biomarker for RA diagnosis and treatment.

Simulation analysis and evaluation of decontamination effect of different abrasive jet process parameters on radioactively contaminated metal

Zhong Lin,Deng Jian,Zuo Zhe-wen,Huang Can-yu,Chen Bo,Lei Lin,Lei Ze-yong,Lei Jie-heng,Zhao Mu,Hua Yun-fei 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.11

A new method of numerical simulating prediction and decontamination effect evaluation for abrasive jet decontamination to radioactively contaminated metal is proposed. Based on the Computational Fluid Dynamics and Discrete Element Model (CFD-DEM) coupled simulation model, the motion patterns and distribution of abrasives can be predicted, and the decontamination effect can be evaluated by image processing and recognition technology. The impact of three key parameters (impact distance, inlet pressure, abrasive mass flow rate) on the decontamination effect is revealed. Moreover, here are experiments of reliability verification to decontamination effect and numerical simulation methods that has been conducted. The results show that: 60Co and other homogeneous solid solution radioactive pollutants can be removed by abrasive jet, and the average removal rate of Co exceeds 80%. It is reliable for the proposed numerical simulation and evaluation method because of the well goodness of fit between predicted value and actual values: The predicted values and actual values of the abrasive distribution diameter are Ф57 and Ф55; the total coverage rate is 26.42% and 23.50%; the average impact velocity is 81.73 m/s and 78.00 m/s. Further analysis shows that the impact distance has a significant impact on the distribution of abrasive particles on the target surface, the coverage rate of the core area increases at first, and then decreases with the increase of the impact distance of the nozzle, which reach a maximum of 14.44% at 300 mm. It is recommended to set the impact distance around 300 mm, because at this time the core area coverage of the abrasive is the largest and the impact velocity is stable at the highest speed of 81.94 m/s. The impact of the nozzle inlet pressure on the decontamination effect mainly affects the impact kinetic energy of the abrasive and has little impact on the distribution. The greater the inlet pressure, the greater the impact kinetic energy, and the stronger the decontamination ability of the abrasive. But in return, the energy consumption is higher, too. For the decontamination of radioactively contaminated metals, it is recommended to set the inlet pressure of the nozzle at around 0.6 MPa. Because most of the Co elements can be removed under this pressure. Increasing the mass and flow of abrasives appropriately can enhance the decontamination effectiveness. The total mass of abrasives per unit decontamination area is suggested to be 50 g because the core area coverage rate of the abrasive is relatively large under this condition; and the nozzle wear extent is acceptable

Transcriptome analysis of Δmig1Δmig2 mutant reveals their roles in methanol catabolism, peroxisome biogenesis and autophagy in methylotrophic yeast Pichia pastoris

Lei Shi,Xiaolong Wang,Jinjia Wang,Ping Zhang,Fei Qi,Menghao Cai,Yuanxing Zhang,Xiangshan Zhou 한국유전학회 2018 Genes & Genomics Vol.40 No.4

Two catabolite repressor genes (MIG1 and MIG2) were previously identified in Pichia pastoris, and the derepression of alcohol oxidase (AOX) expression was realized in Δmig1 or Δmig1Δmig2 mutants grown in glycerol, but not in glucose. In this study, genome-wide RNA-seq analysis of Δmig1Δmig2 and the wild-type strain grown in glycerol revealed that the expression of numerous genes was greatly altered. Nearly 7% (357 genes) of approximately 5276 genes annotated in P. pastoris were significantly upregulated, with at least a two-fold differential expression in Δmig1Δmig2; the genes were mainly related to cell metabolism. Approximately 23% (1197 genes) were significantly downregulated; these were mainly correlated with the physiological characteristics of the cell. The methanol catabolism and peroxisome biogenesis pathways were remarkably enhanced, and the genes AOX1 and AOX2 were upregulated higher than 30-fold, which was consistent with the experimental results of AOX expression. The Mig proteins had a slight effect on autophagy when cells were grown in glycerol. The expression analysis of transcription factors showed that deletion of MIG1 and MIG2 significantly upregulated the binding of an essential transcription activator, Mit1p, with the AOX1 promoter, which suggested that Mig proteins might regulate the AOX1 promoter through the regulation of Mit1p. This work provides a reference for the further exploration of the methanol induction and catabolite repression mechanisms of AOX expression in methylotrophic yeasts.

Pretreatment with the Total Flavone Glycosides of Flos Abelmoschus manihot and Hyperoside Prevents Glomerular Podocyte Apoptosis in Streptozotocin-Induced Diabetic Nephropathy

Lei Zhou,Xiao-Fei An,Shi-Chao Teng,Jing-Shun Liu,Wen-Bin Shang,Ai-Hua Zhang,Yang-Gang Yuan,Jiang-Yi Yu 한국식품영양과학회 2012 Journal of medicinal food Vol.15 No.5

Diabetic nephropathy (DN) is an important diabetic complication, and podocyte apoptosis plays a critical role in the development of DN. In the present study, we examined the preventive effect of the total flavone glycosides of Flos Abelmoschus manihot (TFA) on urinary microalbumin and glomerular podocyte apoptosis in experimental DN rats. The preliminary oral administration of TFA (200 mg/kg/day) for 24 weeks significantly decreased the urinary microalbumin to creatinine ratio and 24-h urinary total protein in streptozotocin-induced DN rats. Terminal deoxynucleotidyl transferasemediated dUTP nick end-labeling assay indicated glomerular cell apoptosis in DN rats was significantly improved by pretreatment with TFA. Furthermore, fluorescence-activated cell sorting and Hoechst 33342 staining suggested preincubation with hyperoside (50 and 200 lg/mL), the major active constituent of TFA, could significantly mitigate cultured podocyte apoptosis induced by the advanced glycation end-products (AGEs). Western blot analysis showed that increased caspase-3 and caspase-8 expressions induced by AGEs were also inhibited by pretreatment with hyperoside at both doses. Our results demonstrate that TFA pretreatment can decrease urinary albumin excretion in early-stage DN, which might be accomplished by preventing renal damage and podocyte apoptosis.

A Novel Kinetic Analysis of Crystallization of Polypropylene (PP) in Dynamically-vulcanized PP/Ethylene-propylene-diene Rubber (EPDM) Blends Using an In-situ Measurement Technique

Lei Hu,Bin Yang,Yan-Li Deng,Fei-Xue Lu,Ru Xia,Zheng-Zhi Zheng,Ji-Bin Miao,Jia-Sheng Qian,Chuan-Ru Zhang,Peng Chen,Yu-Chuan Zhang 한국고분자학회 2017 폴리머 Vol.41 No.4

The effects of cooling medium temperatures and plastic/rubber ratios on solidification and crystallization kinetics of dynamically-vulcanized polypropylene/ethylene-propylene-diene rubber (PP/EPDM) blends were investigated with the aid of an in-situ measurement technique. The cooling medium temperature heavily influenced the solidification kinetics primarily due to a combination of latent heat liberated from the molten polymer and the heat transferred away via the metallic wall during the cooling period. Interestingly, the parameter C in three-parameter model was not only affected by the material properties, but also by the cooling condition, different from the previous literature. The crystallization kinetics analysis indicated that the effect of EPDM in the blends consisted of both nucleation-promoting effect (low EPDM loading) and steric effect (higher EPDM loading). The present kinetic analysis may be helpful to further studies on improving the product performances for industrial applications.

Image Inpainting Based on Exemplar and Sparse Representation

Lei Zhang,Baosheng Kang,Benting Liu,Fei Zhang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.9

We propose a novel image inpainting approach in which the exemplar and the sparse representation are combined together skillfully. In the process of image inpainting, often there will be such a situation: although the sum of squared differences (SSD) of exemplar patch is the smallest among all the candidate patches, there may be a noticeable visual discontinuity in the recovered image when using the exemplar patch to replace the target patch. In this case, we cleverly use the sparse representation of image over a redundant dictionary to recover the target patch, instead of using the exemplar patch to replace it, so that we can promptly prevent the occurrence and accumulation of errors, and obtain satisfied results. Experiments on a number of real and synthetic images demonstrate the effectiveness of proposed algorithm, and the recovered images can better meet the requirements of human vision.

Predict Time Series with Multiple Artificial Neural Networks

Fei Li,Jin Liu,Lei Kong 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.7

Time series prediction is a challenging research area with broad application prospects in machine learning. Accurate prediction on a time series’ value can provide important information for the decision-makers. In the literature, many works were reported to extend different architecture of artificial neural networks to work with time series prediction. However, most of the work only considered the target time series itself, while neglecting the impact of the relevant time series. In this paper we proposed a novel method MANNP that makes use of multiple artificial neural networks to conduct the time series prediction. The proposed method creates time series model and forecast time series. To verify the effectiveness of the proposed method, we apply MANNP to a shipping price index time series prediction. The experimental results show that this method can improve accuracy of prediction when compared with traditional methods.

Sustained ocular delivery of desmopressin acetate via thermoreversible in situ gel formulation: preparation and in vitro/in vivo evaluation

Lei Fang,Zhang Huimin,Luo Rui,Fei Qingsong,Bai Luyu,He Ning 한국약제학회 2022 Journal of Pharmaceutical Investigation Vol.52 No.5

Purpose The present study was designed to formulate a thermoreversible in situ gel system for sustained ocular delivery of desmopressin acetate (DDAVP) for the treatment of polyuria. Methods The cold method was employed for the preparation of in situ gel formulations using different levels of poloxamer 407 (F-127) and carboxymethyl chitosan (CMCTS). The optimal formulation was selected based on gelation temperature, rheological behavior, and in vitro drug release, and further evaluated by thermal, ocular irritation, residence time, in vivo pharmacokinetics, and pharmacodynamic analyses. Results The optimal formulation, composed of F-127 (20%) and CMCTS (1.5%), showed appropriate fluidity at room temperature (25 °C) and transitioned to semisolid gels at physiological temperature (34 °C). The optimal gels showed pseudoplastic fluid properties and favorable thixotropy characteristics in rheological tests. Differential scanning calorimetry analysis revealed even dispersal of DDAVP in the matrix of gels. Results from in vivo studies demonstrated that the newly prepared gel successfully prolonged the residence time of DDAVP, improved ocular bioavailability, and exerted the same antidiuretic effect as ophthalmic drops. Conclusion The developed thermoreversible ophthalmic in situ gel of DDAVP presents a promising formulation for the treatment of polyuria.

RBF Neural Networks-Based Robust Adaptive Tracking Control for Switched Uncertain Nonlinear Systems

Lei Yu,Shumin Fei,Xun Li 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.2

In this paper, a robust adaptive H∞ control scheme is presented for a class of switched uncertain nonlinear systems. Radical basis function neural networks (RBF NNs) are employed to approximate unknown nonlinear functions and uncertain terms. A robust H∞ controller is designed to enhance robustness due to the existence of the compound disturbance which consists of approximation errors of the neural networks and external disturbance. Adaptive neural updated laws and switching signals are deducted from multiple Lyapunov function approach. It is proved that with the proposed control scheme, the resulting closed-loop switched system is robustly stable and uniformly ultimately bounded (UUB) such that good capabilities of tracking performance is attained and H∞ tracking error performance index is achieved. A practical example shows the effectiveness of the proposed control scheme.