Unraveling the Morphology-Function Relationships of Polyamide Membranes Using Quantitative Electron Tomography

Song, Xiaohui,Smith, John W.,Kim, Juyeong,Zaluzec, Nestor J.,Chen, Wenxiang,An, Hyosung,Dennison, Jordan M.,Cahill, David G.,Kulzick, Matthew A.,Chen, Qian American Chemical Society 2019 ACS APPLIED MATERIALS & INTERFACES Vol.11 No.8

<P>An understanding of how complex nanoscale morphologies emerge from synthesis would offer powerful strategies to construct soft materials with designed structures and functions. However, these kinds of morphologies have proven difficult to characterize, and therefore manipulate, because they are three-dimensional (3D), nanoscopic, and often highly irregular. Here, we studied polyamide (PA) membranes used in wastewater reclamation as a prime example of this challenge. Using electron tomography and quantitative morphometry, we reconstructed the nanoscale morphology of 3D crumples and voids in PA membranes for the first time. Various parameters governing film transport properties, such as surface-to-volume ratio and mass-per-area, were measured directly from the reconstructed membrane structure. In addition, we extracted information inaccessible by other means. For example, 3D reconstruction shows that membrane nanostructures are formed from PA layers 15-20 nm thick folding into 3D crumples which envelope up to 30% void by volume. Mapping local curvature and thickness in 3D quantitatively groups these crumples into three classes, “domes”, “dimples”, and “clusters”, each being a distinct type of microenvironment. Elemental mapping of metal ion adsorption across the film demonstrates that these previously missed parameters are relevant to membrane performance. This imaging-morphometry platform can be applicable to other nanoscale soft materials and potentially suggests engineering strategies based directly on synthesis-morphology-function relationships.</P> [FIG OMISSION]</BR>

Porcine parvovirus nonstructural protein NS1 activates NF-κB and it involves TLR2 signaling pathway

Xiaohui Jin,Yixin Yuan,Chi Zhang,Yong Zhou,Yue Song,Zhanyong Wei,Gaiping Zhang 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.3

Background: Porcine parvovirus (PPV) is a single-stranded DNA virus that causes porcine reproductive failure. It is of critical importance to study PPV pathogenesis for the prevention and control of the disease. NS1, a PPV non-structural protein, is participated in viral DNA replication, transcriptional regulation, and cytotoxicity. Our previous research showed that PPV can activate nuclear factor kappa B (NF-κB) signaling pathway and then up-regulate the expression of interleukin (IL)-6. Objectives: Herein, the purpose of this study is to determine whether the non-structural protein NS1 of PPV also has the same function. Methods: Real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR), enzyme-linked immunosorbent assay, western blot, immunofluorescence assay and small interfering RNA (siRNA) were used. Results: Our findings demonstrated that PPV NS1 protein can up-regulate the expression levels of IL-6 and tumor necrosis factor-alpha in a dose-dependent manner. Moreover, PPV NS1 protein was found to induce the phosphorylation of IκBα, then leading to the phosphorylation and nuclear translocation of NF-κB. In addition, the NS1 protein activated the upstream pathways of NF-κB. Meanwhile, TLR2-siRNA assay showed TLR2 plays an important role in the activation of NF-κB signaling pathway induced by PPV-NS1. Conclusions: These findings indicated that PPV NS1 protein induced the up-regulated of IL-6 expression through activating the TLR2 and NF-κB signaling pathways. In conclusion, these findings provide a new avenue to study the innate immune mechanism of PPV infection.

Transient-Performance-Oriented Discrete-Time Design of Resonant Controller for Three-Phase Grid-Connected Converters

Song, Zhanfeng,Yu, Yun,Wang, Yaqi,Ma, Xiaohui The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4

The use of internal-model-based linear controller, such as resonant controller, is a well-established technique for the current control of grid-connected systems. Attractive properties for resonant controllers include their two-sequence tracking ability, the simple control structure, and the reduced computational burden. However, in the case of continuous-designed resonant controller, the transient performance is inevitably degraded at a low switching frequency. Moreover, available design methods for resonant controller is not able to realize the direct design of transient performances, and the anticipated transient performance is mainly achieved through trial and error. To address these problems, the zero-order-hold (ZOH) characteristic and inherent time delay in digital control systems are considered comprehensively in the design, and a corresponding hold-equivalent discrete model of the grid-connected converter is then established. The relationship between the placement of closed-loop poles and the corresponding transient performance is comprehensively investigated to realize the direct mapping relationship between the control gain and the transient response time. For the benefit of automatic tuning and real-time adaption, analytical expressions for controller gains are derived in detail using the required transient response time and system parameters. Simulation and experimental results demonstrate the validity of the proposed method.

Downregulation of HuR Inhibits the Progression of Esophageal Cancer through Interleukin-18

Xu Xiaohui,Song Cheng,Chen Zhihua,Yu Chenxiao,Wang Yi,Tang Yiting,Luo Judong 대한암학회 2018 Cancer Research and Treatment Vol.50 No.1

Purpose The purpose of this study was to investigate the effect of human antigen R (HuR) downregulation and the potential target genes of HuR on the progression of esophageal squamous cell carcinoma (ESCC). Materials and Methods In this study, a proteomics assay was used to detect the expression of proteins after HuR downregulation, and a luciferase assay was used to detect the potential presence of a HuR binding site on the 3’-untranslated region (3'-UTR) of interleukin 18 (IL-18). In addition, colony formation assay, MTT, EdU incorporation assay, Western blot, flow cytometry, immunohistochemistry, transwell invasion assay, and wound healing assay were used. Results In the present study, we found that the expression of both HuR protein and mRNA levels were higher in tumor tissues than in the adjacent tissues. HuR downregulation significantly suppressed cell proliferation. In addition, the metastasis of esophageal cancer cells was inhibited, while the expression of E-cadherin was increased and the expression of matrix metalloproteinase (MMP) 2, MMP9, and vimentin was decreased after HuR knockdown. Moreover, silencing of HuR disturbed the cell cycle of ESCC cells mainly by inducing G1 arrest. Furthermore, proteomics analysis showed that downregulation of HuR in TE-1 cells resulted in 100 upregulated and 122 downregulated proteins, including IL-18 as a significantly upregulated protein. The expression of IL-18 was inversely regulated by HuR. IL-18 expression was decreased in ESCC tissues, and exogenous IL-18 significantly inhibited the proliferation and metastasis of ESCC cells. The 3'-UTR of IL-18 harbored a HuR binding site, as shown by an in vitro luciferase assay. Conclusion HuR plays an important role in the progression of esophageal carcinoma by targeting IL-18, which may be a potential therapeutic target for the treatment of ESCC.

Transient-Performance-Oriented Discrete-Time Design of Resonant Controller for Three-Phase Grid-Connected Converters

Zhanfeng Song,Yun Yu,Yaqi Wang,Xiaohui Ma 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4

The use of internal-model-based linear controller, such as resonant controller, is a well-established technique for the currentcontrol of grid-connected systems. Attractive properties for resonant controllers include their two-sequence tracking ability, thesimple control structure, and the reduced computational burden. However, in the case of continuous-designed resonant controller,the transient performance is inevitably degraded at a low switching frequency. Moreover, available design methods for resonantcontroller is not able to realize the direct design of transient performances, and the anticipated transient performance is mainlyachieved through trial and error. To address these problems, the zero-order-hold (ZOH) characteristic and inherent time delay indigital control systems are considered comprehensively in the design, and a corresponding hold-equivalent discrete model of thegrid-connected converter is then established. The relationship between the placement of closed-loop poles and the correspondingtransient performance is comprehensively investigated to realize the direct mapping relationship between the control gain and thetransient response time. For the benefit of automatic tuning and real-time adaption, analytical expressions for controller gains arederived in detail using the required transient response time and system parameters. Simulation and experimental resultsdemonstrate the validity of the proposed method.

Amino acid, fatty acid, and carbohydrate metabolomic profi les with ginsenoside-induced insecticidal effi cacy against Ostrinia furnacalis (Guenee)

Shuangli Liu,Xiaohui Wang,Rui Zhang,Mingjie Song,Nanqi Zhang,Wanying Li,Yingping Wang,Yonghua Xu,Lianxue Zhang 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.4

Background: Previous studies have shown the insecticidal efficacy of ginsenosides. In the present study,we aimed to investigate the metabolic mechanism related to the inhibitory effect of panaxadiol saponins(PDSs) against the Asian corn borer Ostrinia furnacalis (Guenee). Methods: Third instar larvae of O. furnacalis were fed normal diets with different concentrations of PDSsfor 4 days. The consumption index, relative growth rate, approximate digestibility, and conversion ofingested and digested food were recorded. A targeted gas chromatographyemass spectrometry assaywas performed to detect the profiles of amino acids, fatty acids, and carbohydrates in larvae ofO. furnacalis. In addition, the activity of detoxification-related enzymes was determined. Results and Conclusions: PDSs decreased the consumption index, relative growth rate, approximate digestibility,and conversion of ingested and digested food in the 3rd instar larvae of O. furnacalis in a dosedependentmanner. PDSs decreased 15 free amino acids, 16 free fatty acids, and 5 carbohydrates andincreased the levels of palmitoleic acid, palmitic acid, and 9-octadecenoic acid in the 3rd instar larvae. The activity of detoxification-related enzymes, such as acetylcholinesterase, glutathione S-transferase,cytochrome P450, carboxylesterase, trehalase, acid phosphatase, and alkaline phosphatase, was reducedin a dose-dependent manner in the 3rd instar larvae exposed to PDSs. These data confirmed theinhibitory effect of PDSs against growth, food utilization, and detoxification in the 3rd instar larvae ofO. furnacalis and the potential for using PDSs as an efficient tool for insect pest management forO. furnacalis larvae.

Study of Credibility Evaluation of Dynamic Models and their Parameters

Guo, Weimin,Ye, Xiaohui,Zhong, Wuzhi,Su, Yi,Tang, Yaohua,Song, Xinli,Liu, Tao The Korean Institute of Electrical Engineers 2014 The Journal of International Council on Electrical Vol.4 No.1

The time-domain simulation plays an important role in planning, designing and operation of the power system, but mismatches between its results and the actual system response show that the credibility evaluation of dynamic models is critical in all the above aspects of power systems. This paper discusses the technologies of credibility evaluation, including hybrid dynamic simulation with PMU measurements, error analysis and the calculated indices. Moreover, a phase shift method is presented to implement hybrid dynamic simulation in PSD-FDS. Then the paper proposes a credibility evaluation scheme to provide solution for the evaluation. At last, one sample is used to validate the implementation of hybrid dynamic simulation, while the other sample illustrates the effectiveness of the credibility evaluation approach.

Amino acid, fatty acid, and carbohydrate metabolomic profiles with ginsenoside-induced insecticidal efficacy against Ostrinia furnacalis (Guenee)

Liu, Shuangli,Wang, Xiaohui,Zhang, Rui,Song, Mingjie,Zhang, Nanqi,Li, Wanying,Wang, Yingping,Xu, Yonghua,Zhang, Lianxue The Korean Society of Ginseng 2020 Journal of Ginseng Research Vol.44 No.4

Background: Previous studies have shown the insecticidal efficacy of ginsenosides. In the present study, we aimed to investigate the metabolic mechanism related to the inhibitory effect of panaxadiol saponins (PDSs) against the Asian corn borer Ostrinia furnacalis (Guenee). Methods: Third instar larvae of O. furnacalis were fed normal diets with different concentrations of PDSs for 4 days. The consumption index, relative growth rate, approximate digestibility, and conversion of ingested and digested food were recorded. A targeted gas chromatographye-mass spectrometry assay was performed to detect the profiles of amino acids, fatty acids, and carbohydrates in larvae of O. furnacalis. In addition, the activity of detoxification-related enzymes was determined. Results and Conclusions: PDSs decreased the consumption index, relative growth rate, approximate digestibility, and conversion of ingested and digested food in the 3rd instar larvae of O. furnacalis in a dose-dependent manner. PDSs decreased 15 free amino acids, 16 free fatty acids, and 5 carbohydrates and increased the levels of palmitoleic acid, palmitic acid, and 9-octadecenoic acid in the 3rd instar larvae. The activity of detoxification-related enzymes, such as acetylcholinesterase, glutathione S-transferase, cytochrome P450, carboxylesterase, trehalase, acid phosphatase, and alkaline phosphatase, was reduced in a dose-dependent manner in the 3rd instar larvae exposed to PDSs. These data confirmed the inhibitory effect of PDSs against growth, food utilization, and detoxification in the 3rd instar larvae of O. furnacalis and the potential for using PDSs as an efficient tool for insect pest management for O. furnacalis larvae.

IMMUNE PARAMETERS AND RESPONSE TO DISEASES CHALLENGE TESTS OF JUVENILE PACFIC WHITE SHRIMP Litopenaeus vannamei FED GRADED LEVEL OF A PROTEASE

M A Kabir Chowdhury,Song Hongli,Liu Yao,Dong Xiaohui 한국수산과학회 양식분과 2015 한국수산과학회 양식분과 학술대회 Vol.2015 No.5

One-Step CVD Synthesis of Few-Layer SnS2/MoS2 Vertical Heterostructures

Hongxiao Zhao,Yong Yan,Xiaohui Song,Aodi Dong,Jian Su,Huimin Jia 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.10

Constructing van der Waals (vdW) heterostructures with various-layered two-dimensional (2D) materials is attractive to design various materials and devices. For controllable fabrication of vdW heterostructures, it is very important to make the growth process clear. In this work, SnS2/MoS2 vertical heterostructures were synthesized by the one-step chemical vapor deposition (CVD) method. The bottom MoS2 triangle layers can be partially or completely covered by SnS2 layers. The interlayer charge separation was also observed in the heterostructures by photo-luminescence (PL) spectroscopy. The growth mechanism of SnS2/MoS2 vertical heterostructures was also discussed for the first time. MoS2 triangle layers form on the substrates at first and then grow a top layer of SnS2. This study will provide an important and practical method, as a guidance to prepare high-quality vertical heterostructures.