FaesPI, a Fagopyrum esculentum PISTILLATA ortholog, is involved only in stamen development

Zheng-Wu Fang,Xue-Ping Li,Xiao-Fang Li,Zhi-Xiong Liu 한국식물학회 2015 Journal of Plant Biology Vol.58 No.2

Arabidopsis thaliana PISTILLATA (PI) and Antirrhinum majus GLOBOSA (GLO), encoding B function MADS-box transcription factors specifying petal and stamen identity, have been intensively studied. To identify the possible roles of GLO/PI-like genes in regulating floral development in species without petals, we isolated and identified a PI ortholog from Fagopyrum esculentum (buckwheat, Polygonaceae), a multi-food-use pseudocereal with healing benefits. Protein sequence alignment and phylogenetic analysis grouped FaesPI into the GLO/PI lineage. Expression analysis suggested that FaesPI was expressed only in developing stamens, distinguishing it from PI and GLO that were expressed in developing petals and stamens. Moreover, ectopic expression of FaesPI rescued stamen development without complementation of petal development in an Arabidopsis pi mutant. Our results suggest that FaesPI is involved only in stamen development in buckwheat. These results also suggest that FaesPI holds potential application for biotechnical engineering to establish a male sterile line of F. esculentum.

A Novel Fast Open-loop Phase Locking Scheme Based on Synchronous Reference Frame for Three-phase Non-ideal Power Grids

Xiong, Liansong,Zhuo, Fang,Wang, Feng,Liu, Xiaokang,Zhu, Minghua,Yi, Hao The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

Rapid and accurate phase synchronization is critical for the reliable control of grid-tied inverters. However, the commonly used software phase-locked loop methods do not always satisfy the need for high-speed and accurate phase synchronization under severe grid imbalance conditions. To address this problem, this study develops a novel open-loop phase locking scheme based on a synchronous reference frame. The proposed scheme is characterized by remarkable response speed, high accuracy, and easy implementation. It comprises three functional cascaded blocks: fast orthogonal signal generation block, fast fundamental-frequency positive sequence component construction block, and fast phase calculation block. The developed virtual orthogonal signal generation method in the first block, which is characterized by noise immunity and high accuracy, can effectively avoid approximation errors and noise amplification in a wide range of sampling frequencies. In the second block, which is the foundation for achieving fast phase synchronization within 3 ms, the fundamental-frequency positive sequence components of unsymmetrical grid voltages can be achieved with the developed orthogonal signal construction strategy and the symmetrical component method. The real-time grid phase can be consequently obtained in the third block, which is free from self-tuning closed-loop control and thus improves the dynamic performance of the proposed scheme. The proposed scheme is adaptive to severe unsymmetrical grid voltages with sudden changes in magnitude, phase, and/or frequency. Moreover, this scheme is able to eliminate phase errors induced by harmonics and random noise. The validity and utility of the proposed scheme are verified by the experimental results.

Directed Evolution of Beta-galactosidase from Escherichia coli into Beta-glucuronidase

Xiong, Ai-Sheng,Peng, Ri-He,Zhuang, Jing,Liu, Jin-Ge,Xu, Fang,Cai, Bin,Guo, Zhao-Kui,Qiao, Yu-Shan,Chen, Jian-Min,Zhang, Zhen,Yao, Quan-Hong Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.3

In vitro directed evolution through DNA shuffling is a powerful molecular tool for creation of new biological phenotypes. E. coli $\beta$-galactosidase and $\beta$-glucuronidase are widely used, and their biological function, catalytic mechanism, and molecular structures are well characterized. We applied an in vitro directed evolution strategy through DNA shuffling and obtained five mutants named YG6764, YG6768, YG6769, YG6770 and YG6771 after two rounds of DNA shuffling and screening, which exhibited more $\beta$-glucuronidase activity than wild-type $\beta$-galactosidase. These variants had mutations at fourteen nucleic acid sites, resulting in changes in ten amino acids: S193N, T266A, Q267R, V411A, D448G, G466A, L527I, M543I, Q626R and Q951R. We expressed and purified those mutant proteins. Compared to the wild-type protein, five mutant proteins exhibited high $\beta$-glucuronidase activity. The comparison of molecular models of the mutated and wildtype enzymes revealed the relationship between protein function and structural modification.

Chopper Controller Based DC Voltage Control Strategy for Cascaded Multilevel STATCOM

Xiong, Lian-Song,Zhuo, Fang The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.2

The superiority of CMI (Cascaded Multilevel Inverter) is unparalleled in high power and high voltage STATCOM (Static Synchronous Compensator). However, the parameters and operating conditions of each individual power unit composing the cascaded STATCOM differ from unit to unit, causing unit voltage disequilibrium on the DC side. This phenomenon seriously impairs the operation performance of STATCOM, and thus maintaining the DC voltage balance and stability becomes critical for cascaded STATCOM. This paper analyzes the case of voltage disequilibrium, combines the operation characteristics of the cascaded STATCOM, and proposes a new DC voltage control scheme with the advantages of good control performance and stability. This hierarchical control method uses software to achieve the total active power control and also uses chopper controllers to enable that the imbalance power can flow among the capacitors in order to keep DC capacitor voltages balance. The operating principle of the chopper controllers is analyzed and the implementation is presented. The major advantages of the proposed control strategy are that the number of PI regulators has been decreased remarkably and accordingly the blindness of system design and debugging also reduces obviously. The simulation reveals that the proposed control scheme can achieve the satisfactory control goals.

Chemiluminescence Determination of Balofloxacin Based on Europium (III)-Sensitized KBrO3-Na2S2O4 Reaction in Micellar Medium

Fang Zhao,Yu Qi,Wei Xiong 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.1

A novel chemiluminescence (CL) flow injection method for the determination of balofloxacin is described. The method is based on the weak CL signal arising from the reaction of KBrO3 with Na2S2O4 in acidic medium being significantly enhanced by balofloxacin in the presence of europium (III) ion and sodium dodecyl benzene sulfonate (SDBS). The experimental conditions that affected CL intensity were carefully optimized and the CL reaction mechanism was briefly discussed. Under the optimum conditions, the relative CL intensity was proportional to the concentration of balofloxacin in the range of 7.0 × 10−11 to 3.0 × 10−7 g mL−1. The detection limit was 2.7 × 10−11 g mL−1 and the relative standard deviation was 2.1% for 7.0 × 10−10 g mL−1 balofloxacin (n = 13). The proposed method was successfully applied to the determination of balofloxacin in pharmaceutical formulations and biological fluids.

A Quantitative Evaluation and Comparison of Harmonic Elimination Algorithms Based on Moving Average Filter and Delayed Signal Cancellation in Phase Synchronization Applications

Xiong, Liansong,Zhuo, Fang,Wang, Feng,Liu, Xiaokang,Zhu, Minghua,Yi, Hao The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

The harmonic components of grid voltage result in oscillations of the calculated phase obtained via phase synchronization. This affects the security and stability of grid-connected converters. Moving average filter, delayed signal cancellation and their related harmonic elimination algorithms are major methods for such issues. However, all of the existing methods have their limitations in dealing with multiple harmonics issues. Furthermore, few studies have focused on a comparison and evaluation of these algorithms to achieve optimal algorithm selections in specific applications. In this paper, these algorithms are quantitatively analyzed based on the derived mathematical models. Moreover, an enhanced moving average filter and enhanced delayed signal cancellation algorithms, which are applicable for eliminating a group of selective harmonics with only one calculation block, are proposed. On this basis, both a comprehensive comparison and a quantitative evaluation of all of the aforementioned algorithms are made from several aspects, including response speed, required data storage size, sensitivity to sampling frequency, and elimination of random noise and harmonics. With the conclusions derived in this paper, better overall performance in terms of harmonic elimination can be achieved. In addition, experimental results under different conditions demonstrate the validity of this study.

Association Between Insulin-like Growth Factor-2 Expression and Prognosis after Transcatheter Arterial Chemoembolization and Octreotide in Patients with Hepatocellar Carcinoma

Xiong, Zheng-Ping,Huang, Fang,Lu, Meng-Hou Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.7

Objective: To investigate the association between the change of IGF-2 level in serum after transcatheter arterial chemoembolization (TACE) and hepatocellular carcinoma (HCC) progression, especially in relation to metastasis. Methods: IGF-2 in serum was measured by quantitative sandwich enzyme-linked immunosorbent assaybefore, 3 days and 4 weeks after TACE in 60 patients with HCC. The occurrence of HCC metastasis was also evaluated, 3 months after TACE. Results: (1) The average serum level of IGF-2 in the 60 patients with HCC was $136.5{\pm}87.3$ pg/ml; (2) A tendency for increase was observed with heterogenous uptake of octreotide and portal vein thrombosis. Metastatic foci were found in 37/38 patients in the group with IGF-2 increasing (97.0%), in contrast to 3/22 (13.6%) patients with IGF-2 decrease. Conclusion: The increase of IGF-2 level in serum appears to be associated with the occurrence of metastatic HCC after TACE and chemotherapy.

A Novel Social Context-Aware Data Forwarding Scheme in Mobile Social Networks

Fang Xu,Huyin Zhang,Min Deng,Ning Xu,Zhiyong Wang,Zenggang Xiong,Conghuan Ye 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.6

Routing in disconnected delay-tolerant mobile ad hoc networks (MANETs) continues to be a challenging issue. Several works have been done to address the routing issues using the social behaviors of each node. Mobile Social Networks (MSNs) are increasingly popular type of Delay Tolerant Networks (DTNs). The routing performance improves when knowledge regarding the expected topology and the social context information of the networks. In this paper, we introduce a new metric for data forwarding based on social context information, in which node’s social context information is used to calculate the encounter utility between a node and destination, and the social relationship of network nodes is used to calculate the betweenness centrality utility of a node. We combine two utility functions to derive the social strength among users and their importance. We also present social context-based data forwarding algorithm for routing decision. Extensive simulations on real traces show that the introduced algorithm is more efficient than the existing algorithms.

Selective hydrogenation of benzene over Ru supported on surface modified TiO2

Fang Hao,Jingsong Zheng,Donghong Ouyang,Wei Xiong,Pingle Liu,Hean Luo 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.4

A series of catalysts with ruthenium nanoparticles (NPs) loaded on the binary oxide TS (TiO2-SiO2) support were prepared by facile sol-gel method for benzene selective hydrogenation. Different mole ratios of Ti/Si were investigated. The catalytic structure, composition, hydrophilicity, electronic state and acidity were characterized. The results indicate that the acidity of the samples increases gradually with the increase of the SiO2 amount. The dispersion of ruthenium nanoparticles was improved on binary oxide support compared with TiO2 and an obvious Ru size effect appeared with the increase of Ti/Si molar ratio. It was also found that the hydrophilicity of the supports could be efficiently improved by introducing a small amount of SiO2 to TiO2, which may be due to the large amount of surface hydroxyl groups on the binary oxide samples after SiO2 introduction. This result was consistent with the increasing trend of cyclohexene yield, indicating that the surface hydroxyl groups play a significant role in the motivation of cyclohexene desorption. Ru/TS (7 : 1) showed the best catalytic performance of 38.2% yield to cyclohexene with the highest initial selectivity to cyclohexene (S0) of 87.3%. The catalytic stability experiments showed that the yield of cyclohexene could maintain at 30% after five cycles.

Single-cell RNA sequencing reveals B cell–related molecular biomarkers for Alzheimer’s disease

Xiong Liu-Lin,Xue Lu-Lu,Du Ruo-Lan,Niu Rui-Ze,Chen Li,Chen Jie,Hu Qiao,Tan Ya-Xin,Shang Hui-Fang,Liu Jia,Yu Chang-Yin,Wang Ting-Hua 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

In recent years, biomarkers have been integrated into the diagnostic process and have become increasingly indispensable for obtaining knowledge of the neurodegenerative processes in Alzheimer’s disease (AD). Peripheral blood mononuclear cells (PBMCs) in human blood have been reported to participate in a variety of neurodegenerative activities. Here, a single-cell RNA sequencing analysis of PBMCs from 4 AD patients (2 in the early stage, 2 in the late stage) and 2 normal controls was performed to explore the differential cell subpopulations in PBMCs of AD patients. A significant decrease in B cells was detected in the blood of AD patients. Furthermore, we further examined PBMCs from 43 AD patients and 41 normal subjects by fluorescence activated cell sorting (FACS), and combined with correlation analysis, we found that the reduction in B cells was closely correlated with the patients’ Clinical Dementia Rating (CDR) scores. To confirm the role of B cells in AD progression, functional experiments were performed in early-stage AD mice in which fibrous plaques were beginning to appear; the results demonstrated that B cell depletion in the early stage of AD markedly accelerated and aggravated cognitive dysfunction and augmented the Aβ burden in AD mice. Importantly, the experiments revealed 18 genes that were specifically upregulated and 7 genes that were specifically downregulated in B cells as the disease progressed, and several of these genes exhibited close correlation with AD. These findings identified possible B cell-based AD severity, which are anticipated to be conducive to the clinical identification of AD progression.