MIGRATION OF CHARGED SPECIES IN LIPID BILAYER MEMBRANES UNDER AN ELECTRIC FIELD

XIAOJUN HAN,Lei Wang,CHANGJUN GUO 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.1

This paper reviews recent progress in studies on the migration of charged species, includingcharged lipids, membrane-attached proteins and vesicles, and integrated membrane proteins, inlipid bilayer membranes under an external electric field. The migration of these charged substancesis controlled by the interplay of electrophoresis and electroosmosis. This phenomenon canbe employed to separate the charged lipids and membrane-attached proteins, and concentrateintegrated membrane proteins.

A Two-stage State Transition Algorithm for Constrained Engineering Optimization Problems

Jie Han,Chun-hua Yang,Xiaojun Zhou,Wei-Hua Gui 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.2

In this study, a state transition algorithm (STA) is investigated into constrained engineering design optimization problems. After an analysis of the advantages and disadvantages of two well-known constraint-handling techniques, penalty function method and feasibility preference method, a two-stage strategy is incorporated into STA, in which, the feasibility preference method is adopted in the early stage of an iteration process whilst it is changed to the penalty function method in the later stage. Then, the proposed STA is used to solve three benchmark problems in engineering design and an optimization problem in power-dispatching control system for the electrochemical process of zinc. The experimental results have shown that the optimal solutions obtained by the proposed method are all superior to those by typical approaches in the literature in terms of both convergency and precision.

Antiviral effects of Bovine antimicrobial peptide against TGEV in vivo and in vitro

Xiuli Liang,Xiaojun Zhang,Kaiqi Lian,Xiuhua Tian,Mingliang Zhang,Shiqiong Wang,Cheng Chen,Cunxi Nie,Yun Pan,Fangfang Han,Zhanyong Wei,Wen-Ju Zhang 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.5

Background: In suckling piglets, transmissible gastroenteritis virus (TGEV) causes lethal diarrhea accompanied by high infection and mortality rates, leading to considerable economic losses. This study explored methods of preventing or inhibiting their production. Bovine antimicrobial peptide-13 (APB-13) has antibacterial, antiviral, and immune functions. Objectives: This study analyzed the efficacy of APB-13 against TGEV through in vivo and in vitro experiments. Methods: The effects of APB-13 toxicity and virus inhibition rate on swine testicular (ST) cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT). The impact of APB-13 on virus replication was examined through the 50% tissue culture infective dose (TCID50). The mRNA and protein levels were investigated by real-time quantitative polymerase chain reaction and western blot (WB). Tissue sections were used to detect intestinal morphological development. Results: The safe and effective concentration range of APB-13 on ST cells ranged from 0 to 62.5 μg/mL, and the highest viral inhibitory rate of APB-13 was 74.1%. The log10TCID50 of 62.5 μg/mL APB-13 was 3.63 lower than that of the virus control. The mRNA and protein expression at 62.5 μg/mL APB-13 was significantly lower than that of the virus control at 24 hpi. Piglets in the APB-13 group showed significantly lower viral shedding than that in the virus control group, and the pathological tissue sections of the jejunum morphology revealed significant differences between the groups. Conclusions: APB-13 exhibited good antiviral effects on TGEV in vivo and in vitro.

MiR-30c facilitates natural killer cell cytotoxicity to lung cancer through targeting GALNT7

Gao Fei,Han Jianjun,Jia Li,He Jun,Wang Yun,Chen Mi,Liu Xiaojun,He Xia 한국유전학회 2023 Genes & Genomics Vol.45 No.2

Background MicroRNAs (miRNAs) have been reported to play important roles in regulating natural killer (NK) cell cytotoxicity to cancer cells. Objective This study aimed to investigate the effects and potential mechanism of miR-30c in regulating NK cell cytotoxicity to lung cancer cells. Methods Primary NK cells were derived from the peripheral blood of lung cancer and normal participants. Exosomes were isolated and validated via transmission electron microscopy and nanoparticle tracking analysis. The levels of miR-30c, polypeptide N-acetylgalactosaminyltransferase 7 (GALNT7) and proteins in PI3K/AKT pathway were determined using quantitative real-time polymerase chain reaction or western blot. Tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) levels and the cytotoxicity of effector NK cells to target lung cancer cells were measured via enzyme linked immunosorbent assay, cell apoptosis or xenograft experiments. The relationship between miR-30c and GALNT7 was analyzed by luciferase activity, RNA pull-down and RNA immunoprecipitation assays. And a xenograft mice model was established to verify the effect of miR-30c in regulating NK cell cytotoxicity to lung cancer cells in vivo. Results NK cell-derived exosomes carrying miR-30c, and miR-30c level was significantly downregulated in primary NK cells of lung cancer patients. MiR-30c overexpression promoted TNF-α and IFN-γ secretion and enhanced the cytotoxicity of interleukin 2 (IL-2)-treated NK cells to lung cancer cells, while knockdown of miR-30c played an opposite effect in regulating the cytotoxicity of NK cells to lung cancer cells. GALNT7 was a target of miR-30c and was negatively regulated by miR-30c. Besides, miR-30c targeted GALNT7 to exert its function in regulating NK cell cytotoxicity. Furthermore, GALNT7 prompted the activation of PI3K/AKT pathway in NK cells. Additionally, miR-30c overexpression enhanced NK cell cytotoxicity to lung cancer cells and inhibited tumor growth in vivo. Conclusion miR-30c enhanced NK cell cytotoxicity to lung cancer cells via decreasing GALNT7 and inactivating the PI3K/AKT pathway, suggesting that regulating miR-30c expression maybe a promising approach for enhancing NK cell-based antitumor therapies.

Investigation on Structure and Properties of a Novel Designed Peptide with Half-Sequence Ionic Complement

Ruan, Li-Ping,Luo, Han-Lin,Zhang, Hang-Yu,Zhao, Xiaojun The Polymer Society of Korea 2009 Macromolecular Research Vol.17 No.8

Although the existing design principle of full-sequence ionic complement is convenient for the development of peptides, it greatly constrains the exploration of peptides with other possible assembly mechanisms and different yet essential functions. Herein, a novel designed half-sequence ionic complementary peptide (referred to as P9), AC-Pro-Ser-Phe-Asn-Phe-Lys-Phe-Glu-Pro-$NH_2$, is reported. When transferred from pure water to sodium chloride solution, P9 underwent a dramatic morphological transformation from globular aggregations to nanofibers. Moreover, the rheological experiment showed that the P9 could form a hydrogel with a storage modulus of about 30 Pa even at very low peptide concentration (0.5% (wt/vol)). The P9 hydrogel formed in salt solution could recover in a period of about 1,800 sec, which is faster than that in the pure water. The data suggestcd that the half-sequence, ionic complementary peptide might be worthy of further research for its special properties.

A Fully Automatic Ocular Artifact Removal from EEG Based on Fourth-order Tensor Method

Sunan Ge,Min Han,Xiaojun Hong 대한의용생체공학회 2014 Biomedical Engineering Letters (BMEL) Vol.4 No.2

Purpose The aim of this paper is to propose a fully automatic system using the underdetermined blind source separation (UBSS) method and kurtosis to remove ocular artifacts (OAs) from scalp electroencephalogram (EEG). Methods The fully automatic system about OAs rejection is devised with the fourth-order tensor method (FOOBI). Firstly, the FOOBI method decomposes multiple EEG channels into a relative large number of source components. The kurtosis value is used to identify the ocular components in these source components. Then, the free-ocular sources components are reconstructed to EEG without OAs. Results The simulations show that the FOOBI method can completely separate the ocular signals from the observed signals. The data that have got rid of the OAs are used to classify with the epileptic EEG. The classification accuracy acquired by FOOBI method is better than the independent component analysis (ICA). Conclusions The results inferred that the FOOBI method can not only completely remove the OAs from the observed signals but also preserve an amount of useful information of EEG. Compared with the ICA method, this fully automatic system is more suitable to remove OAs.

Analysis and Control of an MMC-HVDC System Under an Unbalanced Grid Condition

Kim Tuan Luu,Minxiao HAN,Senior Member, IEEE,Xiaojun Tang 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.6

Modular multilevel converter (MMC)-based high voltage direct current (HVDC) systems have been increasingly researched and installed in recent years. During operation, systems may be subjected to various unbalanced conditions, the single-line to ground (SLG) fault is one of the most common unbalanced faults. When a SLG fault occurs in a three-phase alternating current (AC) system, the double-line frequency positive- and zero-sequence harmonic components will be produced besides the double-line frequency negative-sequence harmonic component. And if the control system cannot suppress these harmonic components, they can propagate into the direct current (DC) side of the HVDC system and cause ripples in DC-line voltage and current as well as other unwanted consequences. Among the proposed controllers in the published papers on this topic, rarely controllers can both eff ectively suppress the circulating current and completely eliminate ripples in the DC-line voltage and current while still keeping the AC-side current balanced under unbalanced grid conditions. Therefore, this paper fi rst analyses the propagation of harmonic components in a two-terminal MMC-HVDC system under a SLG fault. Then, based on the mathematical analysis, a proposed controller including an inner current controller for controlling the negativeand positive-sequence components and a controller for suppressing the zero-sequence component is designed to eliminate harmonic propagation from the faulty three-phase AC system to the DC side of the HVDC system, resulting in suppressing ripples in DC-line voltage and current. The theoretical analysis and proposed controller are verifi ed by a simulation model in PSCAD platform.

A Fully Automatic Ocular Artifact Removal from EEG Based on Fourth-order Tensor Method

Sunan Ge,Min Han,Xiaojun Hong 대한의용생체공학회 2014 Biomedical Engineering Letters (BMEL) Vol.4 No.1

Purpose The aim of this paper is to propose a fully automaticsystem using the underdetermined blind source separation(UBSS) method and kurtosis to remove ocular artifacts(OAs) from scalp electroencephalogram (EEG). Methods The fully automatic system about OAs rejection isdevised with the fourth-order tensor method (FOOBI). Firstly,the FOOBI method decomposes multiple EEG channels intoa relative large number of source components. The kurtosisvalue is used to identify the ocular components in thesesource components. Then, the free-ocular sources componentsare reconstructed to EEG without OAs. Results The simulations show that the FOOBI method cancompletely separate the ocular signals from the observedsignals. The data that have got rid of the OAs are used toclassify with the epileptic EEG. The classification accuracyacquired by FOOBI method is better than the independentcomponent analysis (ICA). Conclusions The results inferred that the FOOBI methodcan not only completely remove the OAs from the observedsignals but also preserve an amount of useful information ofEEG. Compared with the ICA method, this fully automaticsystem is more suitable to remove OAs.

An Optimal Combined SVM Model for Short-term Wind Speed Forecasting

Bai, Dan-Dan,He, Jing-Han,Tian, Wen-Qi,Wang, Xiaojun,Tony, Yip 대한전기학회 2014 The Journal of International Council on Electrical Vol.4 No.4

A high precise wind speed forecasting method is one of current wind power research hotspots. This paper presented a combined wind speed forecasting model based on support vector machine (SVM) optimized by particle swarm optimization (PSO) using historical data of wind speed at the site. The model took the results of back propagation neural network (BPNN), radial basis function neural network (RBFNN), genetic neural network (GNN) and wavelet neural network (WNN) as the inputs, and adopted the actual wind speed as the output. Meanwhile, particle swarm optimization was used to optimize model parameters. Apply this model in hourly prediction of wind speed using historical data from a wind farm in Shanxi Province. It is observed that its prediction accuracy was not only higher than that of any of its single network but higher than traditional linear combined forecasting model and neural network combined forecasting model.

Study on the role of gga-miRNA-200a in regulating cell differentiation and proliferation of chicken breast muscle by targeting Grb2

Keren Jiang,Fengbin Yan,Meng Zhang,Fang Li,Donghua Li,Guirong Sun,Xiaojun Liu,Hong Li,Ruili Han,Ruirui Jiang,Zhuanjian Li,Xiangtao Kang 한국통합생물학회 2017 Animal cells and systems Vol.21 No.6

Growth factor receptor-bound protein 2 (Grb2) have been proved by a lot of studies playing a major role in cell proliferation and cell differentiation. However, the regulation of Grb2 expression by microRNAs (miRNAs) in chicken breast muscle still remains unknown. The expression profile of Grb2 was checked based on our previous RNA sequencing data and the Grb2 relative expression level in breast muscle of aged hens (55-week-old) was validated significantly higher than juvenile hens (20-week-old) using qRT-PCR. miRNAs that interact with Grb2 have been predicted in chicken and the relationship between the potential miRNA and Grb2 was verified using dual luciferase reporter assay in chicken DF1 cells. Dual-luciferase reporter assays results demonstrated that the expression of luciferase reporter gene linked with part sequence of the 3′UTR of chicken Grb2 gene was down-regulated by the overexpression of gga (Gallus Gallus)- miR-200a-3p in the DF1 cells, and the down-regulation behavior was abolished when the ggamiR- 200a-3p binding site in 3′UTR of Grb2 was mutated, indicating that gga-miR-200a can suppress the expression level of its target gene Grb2. Therefore, we concluded that the significantly increased expression level of Grb2 in the breast muscle of aged chicken can (at least partly can) be explained by the decreased expression of miR-200a, which reduced the inhibitory effect on Grb2. Taken together, these findings suggest that gga-miR-200a can suppress the expression level of its target gene Grb2 and might be involved in the cell differentiation and proliferation of chicken breast muscle through binding with the 3’UTR of Grb2.