MicroRNA 449c Mediates the Generation of Monocytic Myeloid-Derived Suppressor Cells by Targeting STAT6

Han, Xiaoqing,Luan, Tao,Sun, Yingying,Yan, Wenyi,Wang, Dake,Zeng, Xianlu Korean Society for Molecular and Cellular Biology 2020 Molecules and cells Vol.43 No.9

Myeloid-derived suppressor cells (MDSCs) promote tumour progression by contributing to angiogenesis, immunosuppression, and immunotherapy resistance. Although recent studies have shown that microRNAs (miRNAs) can promote the expansion of MDSCs in the tumour environment, the mechanisms involved in this process are largely unknown. Here, we report that microRNA 449c (miR-449c) expression was upregulated in myeloid progenitor cells upon activation of C-X-C motif chemokine receptor 2 (CXCR2) under tumour conditions. MiR-449c upregulation increased the generation of monocytic MDSCs (mo-MDSCs). The increased expression of miR-449c could target STAT6 mRNA in myeloid progenitor cells to shift the differentiation balance of myeloid progenitor cells and lead to an enhancement of the mo-MDSCs population in the tumour environment. Thus, our results demonstrate that the miR-449c/STAT6 axis is involved in the expansion of mo-MDSCs from myeloid progenitor cells upon activation of CXCR2, and thus, inhibition of miR-449c/STAT6 signalling may help to attenuate tumour progression.

Study on wireless underground sensor networks for remote irrigation monitoring system

Xiaoqing.Yu,Wenting.Han,Zenglin.Zhang 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.1

Wireless underground sensor networks (WUSN) has wide applications in environmental information monitoring. It plays a vital role in the handling and management of water resources for irrigation. Because it prevents radio interference, improves real-time acquisition of information and reduces energy consumptions. In this work, WUSN was used to collect soil temperature and moisture information of an irrigation system. The base station used the sensor nodes to collect the data in a particular area. All nodes in the networks were the same and energies were constrained. According to the schedule, WUSN nodes turn on or off their radio module to save energy. When the collected data was less than the threshold value, the base station would inform the controller perform a motor control action through setting the corresponding. In this paper, system used data fusion method for saving energy to send collected data to the base station. The testing showed that the system was successfully implemented on a real-time remote monitoring for irrigation. The result was a low cost, highly reliable and simple infrastructure for the collection of soil data over a distributed area in agricultural environments.

Survey on a Novel Wireless Sensor Network Communication at 433MHz Frequency

Xiaoqing Yu,Wengting Han,Zenglin Zhang 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.7

Wireless underground sensor networks (WUSN) are a promising new technology for monitoring soil information with a high spatial and temporal resolution for large areas. However, the significantly high attenuation caused by soil is the main challenge for the feasibility of WUSN. Recent theoretical results highlight the potential of smaller attenuation rates with the use of smaller radio frequencies. In this paper, experimental measurements have been conducted with commodity sensor nodes at the frequency of 433 MHz. Experiments are run to examine the received signal strength of correctly received packets and the packet error rate for a communication link. The tests show the potential feasibility of the WUSN with the use of powerful RF transceivers at 433MHz frequency. Moreover, we also illustrate a classification for wireless underground sensor network communication. Finally, we conclude that the effects of burial depth, inter-node distance and volumetric water content of the soil on the signal strength and packet error rate.

Experimental and Modeling Studies on the Sorption Breakthrough Behaviors of Butanol from Aqueous Solution in a Fixed-bed of KA-I Resin

Xiaoqing Lin,Renjie Li,Qingshi Wen,Jinglan Wu,Jiansheng Fan,Xiaohong Jin,Wenbin Qian,Dong Liu,Xiaochun Chen,Yong Chen,Jingjing Xie,Jianxin Bai,Han-Jie Ying 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.2

Removal of biobutanol from acetone-butanolethanol (ABE) fermentation broth can be achieved by fixed-bed sorption by means of KA-I resin, and the relevant breakthrough curves would provide much valuable information to help design a continuous fixed-bed sorption process in field application. In the present study, the effects of several important design parameters, i.e., initial butanol concentration (Cf: 3.0 ~ 30.0 g/L), inlet flow rate (Qf: 0.5~ 5.5 mL/min) and adsorbent bed height (Z: 4.2 ~ 18.0 cm),on the adsorption breakthrough curves of KA-I resin in a fixed-bed column were investigated. It was found that the amount of adsorbed butanol at breakthrough point was increased with an increase in the value of Cf and Z; and with decrease in the value of Qf. However, the maximum sorption capacities of butanol at saturated point were basically unchanged. Three well-established fixed-bed adsorption models, namely Thomas, Yoon-Nelson and Adams-Bohart,were applied to predict the breakthrough curves and to determine the characteristic parameters of fixed-bed column,which are the basis for the process design at a real scale. Good agreement between the theoretical breakthrough curves and the experimental result were observed using Thomas and Yoon-Nelson models.

Overview of Transmission Characteristics in Novel Wireless Underground Sensor Networks

Xiaoqing Yu,Wenting Han,Zenglin Zhang 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.2

Many applications for agricultural information and environment monitoring exploit buried sensors wired-connected to the soil surface for information retrieval. A novel wireless underground sensor networks is a specialized kind of wireless sensor network that communicates through soil. The wireless underground sensor networks (WUSN) consist of wireless devices that are buried completely under dense soil and operate below the ground surface. In this paper, the application research of the wireless underground sensor networks is described. Experimental measurements of the signal strength and packet error rate are presented at the frequency of 433MHz, which show a good agreement with the theoretical studies. The results show the buried depth of the WUSN node and the volumetric water content of the soil are the most important factor to adversely affect the communication.

Genetic diversity generated by introgression between wild species and cultivars of tree peony in Baokang, China

Jigang Han,Jian Li,Xiaoqing Li,Qunlu Liu,Yonghong Hu 한국원예학회 2021 Horticulture, Environment, and Biotechnology Vol.62 No.2

Tree peonies distributed in Baokang County (Hubei Province, China) (BKTPs) displayed extensive morphological variation,especially in fl ower color patterns and fruit setting rates. The genetic diversity of BKTPs and their relationships to nine wildspecies and 14 representative traditional cultivars were assessed using simple sequence repeat (SSR) markers in this study. All 19 analyzed loci were polymorphic, and 85 alleles were found. The number of alleles per locus varied from 3 to 7, withan average of 4.474. Cluster analysis with UPGMA method based on SSR markers partitioned 46 accessions of BKTPs intotwo major clusters and six subgroups, closing to P. ostii , P. qiui , P. rockii , P. jishanensis and diff erent cultivars, respectively. Analysis of fl avonoids with UPLC-Q-TOF-MS/MS revealed that Pn3G5G and Cy3G5G were the main anthocyanins ofthe pink and reddish-purple fl owers of BKTPs, which were undetectable in white fl owers. The fruit and seed setting ratesof BKTPs ranged from 4.00 to 26.00 per plant, and 130.00 to 858.00 per plant, respectively. The content of unsaturatedfatty acids was over 90% of the total fatty acids in the seed oils of BKTPs, with α-linolenic acid as the dominant compound(42.51–54.93%). Both phenotypic and molecular data suggested that the accessions of BKTPs were a hybrid complex resultedfrom introgression between the sympatrically distributed wild species and cultivars in Baokang, which provided novel geneticresources for tree peony breeding and germplasm innovation.

Adaptive virtual impedance control based on second-order generalized integral for circulating current suppression

Zhang, Baifu,Han, Xiaoqing,Meng, Runquan,Ren, Chunguang,Wang, Lei,Song, Tianhao,Liu, Yizhao The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.1

The redundant design of multi-paralleled bidirectional power converters (BPCs) provides technical support for hybrid microgrid systems to consume more distributed generations (DGs) and DC loads. However, the multi-BPCs also provide paths for circulating current. In addition, the AC sub-grid may operate under unbalanced conditions due to the consumption of single-phase loads and power electronic devices. In addition, unbalanced three-phase voltage deteriorates the generation of circulating current. In this paper, an adaptive virtual impedance control method based on second-order generalized integration (SOGI) is proposed to suppress circulating current on the basic analysis of circulating current generation mechanism, the equivalent model establishment, and the suppression principle. The virtual impedance is dynamically adjusted in real-time based on the power oscillation caused by unbalanced voltage. Moreover, an integral term is added to the reactive power droop control to realize the tracking of voltage without static error. Finally, the effectiveness and feasibility of the proposed control algorithm are verified by experiments. The research results show that the proposed control method can optimize the damping characteristics, reduce the voltage difference between the BPCs, and improve the current sharing effect.

Source Current Control Strategy of Active Power Filters for Unbalanced Load Compensation in Three-Phase Four-Wire Distribution Networks

Lei Wang,Xiaoqing Han,Runquan Meng,Chunguang Ren,Qi Wang,Baifu Zhang 전력전자학회 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

This paper proposes a modified control strategy to improve the performance of three-phase four-leg shunt active power filters (APFs) for the compensation of three phase unbalanced loads. Unbalanced current cannot be obtained accurately by a harmonic detector due to the lower frequency. The proposed control strategy eliminates conventional harmonic detectors by directly regulating the source current. Therefore, the computational complexity is greatly reduced and the performance of the APF is improved. A mathematic model has been developed based on the source currents. The corresponding controllers have been designed based on the sinusoidal internal model principle. The proposed control strategy can guarantee excellent compensation performance and stable operation after an extreme disturbance such as a short circuit fault. In addition, the proposed technique can selectively compensate specific harmonics. A 50kVA prototype APF is implemented in the laboratory to validate the feasibility and performance of the proposed control strategy.

Source Current Control Strategy of Active Power Filters for Unbalanced Load Compensation in Three-Phase Four-Wire Distribution Networks

Wang, Lei,Han, Xiaoqing,Meng, Runquan,Ren, Chunguang,Wang, Qi,Zhang, Baifu The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.5

This paper proposes a modified control strategy to improve the performance of three-phase four-leg shunt active power filters (APFs) for the compensation of three phase unbalanced loads. Unbalanced current cannot be obtained accurately by a harmonic detector due to the lower frequency. The proposed control strategy eliminates conventional harmonic detectors by directly regulating the source current. Therefore, the computational complexity is greatly reduced and the performance of the APF is improved. A mathematic model has been developed based on the source currents. The corresponding controllers have been designed based on the sinusoidal internal model principle. The proposed control strategy can guarantee excellent compensation performance and stable operation after an extreme disturbance such as a short circuit fault. In addition, the proposed technique can selectively compensate specific harmonics. A 50kVA prototype APF is implemented in the laboratory to validate the feasibility and performance of the proposed control strategy.

Coordinated control of series compensation link and bus interface converter in the AC-DC hybrid microgrid

Meng, Runquan,Du, Yi,Han, Xiaoqing,Wang, Lei,Wang, Peng The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.2

To improve the fault ride-through capability and power quality of a hybrid microgrid (HMG), a series compensation link (SCL) is inserted between an AC-DC HMG and a utility grid, which forms a new HMG topology. Correspondingly, a decoupling coordinated control strategy for the SCL and a bidirectional AC-DC interlinking converter (BIC) is proposed based on a small signal model of the entire system and the principle of voltage regulation. The interferences between the SCL and the BIC due to the coupling of control factors are eliminated by the series and parallel decoupling methods that adopt additional current closed-loop control and output voltage feedforward control, respectively. The proposed HMG topology and strategy can ensure the realization of the predesigned functions of dual converters and avoid frequent switching between the grid-tied mode and the island mode, which improves the fault ride-through capability and power quality. Finally, the effectiveness of the proposed approach is verified by simulations and experiments.