Secondary Voltage Control for Reactive Power Sharing in an Islanded Microgrid

Guo, Qian,Wu, Hongyan,Lin, Liaoyuan,Bai, Zhihong,Ma, Hao The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

Owing to mismatched feeder impedances in an islanded microgrid, the conventional droop control method typically results in errors in reactive power sharing among distributed generation (DG) units. In this study, an improved droop control strategy based on secondary voltage control is proposed to enhance the reactive power sharing accuracy in an islanded microgrid. In a DG local controller, an integral term is introduced into the voltage droop function, in which the voltage compensation signal from the secondary voltage control is utilized as the common reactive power reference for each DG unit. Therefore, accurate reactive power sharing can be realized without any power information exchange among DG units or between DG units and the central controller. Meanwhile, the voltage deviation in the microgrid common bus is removed. Communication in the proposed strategy is simple to implement because the information of the voltage compensation signal is broadcasted from the central controller to each DG unit. The reactive power sharing accuracy is also not sensitive to time-delay mismatch in the communication channels. Simulation and experimental results are provided to validate the effectiveness of the proposed method.

Urban Fringe Land Use Problem And Solution In Kaifeng City

GUO Jing,LU Hongyan,JING Fang 대한지리학회 2008 대한지리학회 컨퍼런스 자료집 Vol.2 No.-

Synthesis, Crystal Structures and Properties of Two 3D CdII and ZnII Complexes with a 3-Fold Interpenetrating Feature

Hongyan Lin,Fangfang Sui,Peng Liu,Xiu-Li Wang,Guo-Cheng Liu 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.7

Two new 3D coordination complexes [Cd(3-bpcd)(pht)] (1) and [Zn(3-bpcd)(pht)] (2) [3-bpcd = N,N'-bis(pyridin- 3-yl)cyclohexane-1,4-dicarboxamide, H2pht = phthalic acid] have been hydrothermally synthesized. X-ray diffraction analysis reveals that the complexes 1 and 2 represent a 4-connected diamondoid topology with a 3- fold interpenetrating feature. Moreover, the fluorescent properties of complexes 1 and 2 are studied.

MicroRNA-217 Functions as a Tumour Suppressor Gene and Correlates with Cell Resistance to Cisplatin in Lung Cancer

Guo, Junhua,Feng, Zhijun,Huang, Zhi'ang,Wang, Hongyan,Lu, Wujie Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.9

MiR-217 can function as an oncogene or a tumour suppressor gene depending on cell type. However, the function of miR-217 in lung cancer remains unclear to date. This study aims to evaluate the function of miR-217 in lung cancer and investigate its effect on the sensitivity of lung cancer cells to cisplatin. The expression of miR-217 was detected in 100 patients by real-time PCR. The effects of miR-217 overexpression on the proliferation, apoptosis, migration and invasion of SPC-A-1 and A549 cells were investigated. The target gene of miR-217 was predicted by Targetscan online software, screened by dual luciferase reporter gene assay and demonstrated by Western blot. Finally, the effects of miR-217 up-regulation on the sensitivity of A549 cells to cisplatin were determined. The expression of miR-217 was significantly lower in lung cancer tissues than in noncancerous tissues (p < 0.001). The overexpression of miR-217 significantly inhibited the proliferation, migration and invasion as well as promoted the apoptosis of lung cancer cells by targeting KRAS. The up-regulation of miR-217 enhanced the sensitivity of SPC-A-1 and A549 cells to cisplatin. In conclusion, miR-217 suppresses tumour development in lung cancer by targeting KRAS and enhances cell sensitivity to cisplatin. Our results encourage researchers to use cisplatin in combination with miR-217 to treat lung cancer. This regime might lead to low-dose cisplatin application and cisplatin side-effect reduction.

MicroRNA-217 Functions as a Tumour Suppressor Gene and Correlates with Cell Resistance to Cisplatin in Lung Cancer

Junhua Guo,Zhijun Feng,Zhi’ang Huang,Hongyan Wang,Wujie Lu 한국분자세포생물학회 2014 Molecules and cells Vol.37 No.9

MiR-217 can function as an oncogene or a tumour suppressor gene depending on cell type. However, the function of miR-217 in lung cancer remains unclear to date. This study aims to evaluate the function of miR-217 in lung cancer and investigate its effect on the sensitivity of lung cancer cells to cisplatin. The expression of miR-217 was detected in 100 patients by real-time PCR. The effects of miR-217 overexpression on the proliferation, apoptosis, migration and invasion of SPC-A-1 and A549 cells were investigated. The target gene of miR-217 was predicted by Targetscan online software, screened by dual luciferase reporter gene assay and demonstrated by Western blot. Finally, the effects of miR-217 up-regulation on the sensitivity of A549 cells to cisplatin were determined. The expression of miR-217 was significantly lower in lung cancer tissues than in noncancerous tissues (p < 0.001). The overexpression of miR-217 significantly inhibited the proliferation, migration and invasion as well as promoted the apoptosis of lung cancer cells by targeting KRAS. The up-regulation of miR-217 enhanced the sensitivity of SPC-A-1 and A549 cells to cisplatin. In conclusion, miR-217 suppresses tumour development in lung cancer by targeting KRAS and enhances cell sensitivity to cisplatin. Our results encourage researchers to use cisplatin in combination with miR-217 to treat lung cancer. This regime might lead to low-dose cisplatin application and cisplatin side-effect reduction.

Secondary Voltage Control for Reactive Power Sharing in an Islanded Microgrid

Qian Guo,Hongyan Wu,Liaoyuan Lin,Zhihong Bai,Hao Ma 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.1

Owing to mismatched feeder impedances in an islanded microgrid, the conventional droop control method typically results in errors in reactive power sharing among distributed generation (DG) units. In this study, an improved droop control strategy based on secondary voltage control is proposed to enhance the reactive power sharing accuracy in an islanded microgrid. In a DG local controller, an integral term is introduced into the voltage droop function, in which the voltage compensation signal from the secondary voltage control is utilized as the common reactive power reference for each DG unit. Therefore, accurate reactive power sharing can be realized without any power information exchange among DG units or between DG units and the central controller. Meanwhile, the voltage deviation in the microgrid common bus is removed. Communication in the proposed strategy is simple to implement because the information of the voltage compensation signal is broadcasted from the central controller to each DG unit. The reactive power sharing accuracy is also not sensitive to time-delay mismatch in the communication channels. Simulation and experimental results are provided to validate the effectiveness of the proposed method.

Molecular Cloning and Functional Analysis of the Gene Encoding 3-hydroxy-3-methylglutaryl Coenzyme A Reductase from Hazel (Corylus avellana L. Gasaway)

Wang, Yechun,Guo, Binhui,Zhang, Fei,Yao, Hongyan,Miao, Zhiqi,Tang, Kexuan Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.6

The enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR; EC1.1.1.34) catalyzes the first committed step of isoprenoids biosynthesis in MVA pathway. Here we report for the first time the cloning and characterization of a full-length cDNA encoding HMGR (designated as CgHMGR, GenBank accession number EF206343) from hazel (Corylus avellana L. Gasaway), a taxol-producing plant species. The full-length cDNA of CgHMGR was 2064 bp containing a 1704-bp ORF encoding 567 amino acids. Bioinformatic analyses revealed that the deduced CgHMGR had extensive homology with other plant HMGRs and contained two transmembrane domains and a catalytic domain. The predicted 3-D model of CgHMGR had a typical spatial structure of HMGRs. Southern blot analysis indicated that CgHMGR belonged to a small gene family. Expression analysis revealed that CgHMGR expressed high in roots, and low in leaves and stems, and the expression of CgHMGR could be up-regulated by methyl jasmonate (MeJA). The functional color assay in Escherichia coli showed that CgHMGR could accelerate the biosynthesis of $\beta$-carotene, indicating that CgHMGR encoded a functional protein. The cloning, characterization and functional analysis of CgHMGR gene will enable us to further understand the role of CgHMGR involved in taxol biosynthetic pathway in C. avellana at molecular level.

Exosomes Derived from Human Amniotic Mesenchymal Stem Cells Facilitate Diabetic Wound Healing by Angiogenesis and Enrich Multiple lncRNAs

Fu Shangfeng,Zhang Hongyan,Li Xiancai,Zhang Qiling,Guo Chunyan,Qiu Keqing,Feng Junyun,Liu Xiaoxiao,Liu Dewu 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.2

BACKGROUND: Diabetic wound healing remains a major challenge due to the impaired functionality of angiogenesis by persistent hyperglycemia. Mesenchymal stem cell exosomes are appropriate candidates for regulating the formation of angiogenesis in tissue repair and regeneration. Here, we explored the effects of exosomes derived from human amniotic mesenchymal stem cell (hAMSC-Exos) on the biological activities of human umbilical vein endothelial cells (HUVECs) treated with high glucose and on diabetic wound healing and investigate lncRNAs related to angiogenesis in hAMSC-Exos. METHODS: hAMSCs and hAMSC-Exos were isolated and identified by flow cytometry or western blot. A series of functional assays such as cell counting kit-8, scratching, transwell and tube formation assays were performed to evaluate the potential effect of hAMSC-Exos on high glucose-treated HUVECs. The effect of hAMSC-Exos on diabetic wound healing were tested by measuring wound closure rates and immunohistochemical staining of CD31. Subsequently, the lncRNAs profiles in hAMSC-Exos and hAMSCs were examined to screen the lncRNAs related to angiogenesis. RESULTS: The isolated hAMSC-Exos had a size range of 30–150 nm and were positive for CD9, CD63 and CD81. The hAMSC-Exos facilitate the functional properties of high glucose-treated HUVECs including the proliferation, migration and the angiogenic activities as well as wound closure and angiogenesis in diabetic wound. hAMSC-Exos were enriched lncRNAs that related to angiogenesis, including PANTR1, H19, OIP5-AS1 and NR2F1-AS1. CONCLUSION: Our findings demonstrated hAMSC-Exos facilitate diabetic wound healing by angiogenesis and contain several exosomal lncRNAs related to angiogenesis, which may represent a promising strategy for diabetic wound healing.

Rapid quantitative typing spectra model for distinguishing sweet and bitter apricot kernels

Xue Huang,Jiayi Xu,Feng Gao,Hongyan Zhang,Ling Guo 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.9

Amygdalin content in apricot kernels is an essential factor in the rapid and nondestructive identification of sweet or bitter apricot kernels through spectroscopy. Now, amygdalin content has been determined by high-performance liquid chromatography and near-infrared spectral database to construct a model so that the sweet or bitter apricot kernels could be identified and classified. Principal component analysis–K-nearest neighbor classification algorithm combined with multivariate scattering correction pretreatment method could distinguish sweet and bitter apricot kernels in the wavelength range of 1650–1740 nm with 98.3% accuracy and apricot kernel species with 96.3% recognition rate in the full wavelength spectrum. Furthermore, prediction of amygdalin content in bitter and sweet apricot kernels by partial least squares model was superior to that by back-propagation neural network model. This study provides a theoretical basis for quality identification of apricot kernel quality, as well as a method for nondestructive and rapid detection of sweet and bitter apricot kernels.

Increased brain uptake of venlafaxine loaded solid lipid nanoparticles by overcoming the efflux function and expression of P-gp

Yan Zhou,Xin’an Wu,Guo-Qiang Zhang,Zhi Rao,Yang Yang,Qian Zhou,Hongyan Qin,Yuhui Wei 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.7

Venlafaxine (VLX) could be pumped out of the brain by P-glycoprotein (P-gp). Moreover, the expression of P-gp distributed in blood–brain barrier could be significantly induced by VLX. Thus, P-gp could be considered as the nature barrier for delivering of VLX to the brain. The aim of this study was to investigate whether the efflux function and increased expression of P-gp could be reversed by utilizing solid lipid nanoparticles (SLN). VLX solid lipid nanoparticles (VLX - SLN) were prepared and evaluated. Pharmacokinetics and brain distribution of VLX in different formulations were conducted after oral or intravenous administration. P-gp efflux function to VLX was evaluated by the brain uptake amount of VLX, while P-gp expression was investigated by Western blotting. Results indicated that the entrapment, mean size and zata potential of VLX - SLN was 74.9 ± 3.0 %, 186.3 ± 69.26 nm and -22.8 ± 7.78 mv, respectively. After vein injection of VLX formulations, the brain uptake amount of VLX from VLX - SLN was significantly higher than that of VLX solution, VLX solution with empty SLN (VLX? empty SLN) and VLX solution with Verapamil (VLX ? Ver), respectively. Furthermore, the protein mass of P-gp in VLX - SLN treated group was the lowest among all the investigated groups. These results indicated that SLN could overcome P-gp and achieve brain target by intravenous administration.