Trajectory Linearization Based Output Tracking Control of an Unmanned Tandem Helicopter with Variance Constraints

Shi-Qian Liu,Zhong-Liang Jing,Jun-Guo Lu 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.6

An output tracking control problem for an unmanned tandem rotor helicopter with variance constraints is investigated in this paper. A modified Trajectory Linearization Control (TLC) is proposed to stabilize a nonlinear continuous-time flight dynamics system of the tandem helicopter. The tracking controller structure of TLC is designed by using two-time-scale nonlinear dynamic inversion. The base control law of the translational and attitude loops is designed in a pseudo-inversion feedforward con-troller to deal with nonlinear features of the plant and a proportional integral controller to stabilize the linear slowly time-variant error system resulted from the nonlinear flight system. Furthermore, a feasi-ble TLC strategy is designed to meet a performance index set including steady trajectory tracking error variance and desired Parallel D-spectrum (PD-) eigenvalues to achieve good flight quality. The Vari-ance-constrained Trajectory Linearization Control (VCTLC) is designed to realize the desired steady tracking precision and agile capability. Flight simulation results show the VCTLC method is feasible and effective in attitude and altitude tracking.

Emerging roles of centromeric RNAs in centromere formation and function

Qian Liu,Yang Liu,Qinghua Shi,Handong Su,Chunhui Wang,James A. Birchler,Fangpu Han 한국유전학회 2021 Genes & Genomics Vol.43 No.3

Background Centromeres are specialized chromosomal domains involved in kinetochore formation and faithful chromosome segregation. Despite a high level of functional conservation, centromeres are not identifed by DNA sequences, but by epigenetic means. Universally, centromeres are typically formed on highly repetitive DNA, which were previously considered to be silent. However, recent studies have shown that transcription occurs in this region, known as centromeric-derived RNAs (cenRNAs). CenRNAs that contribute to fundamental aspects of centromere function have been recently investigated in detail. However, the distribution, behavior and contributions of centromeric transcripts are still poorly understood. Objective The aim of this article is to provide an overview of the roles of cenRNAs in centromere formation and function. Methods We describe the structure and DNA sequence of centromere from yeast to human. In addition, we briefy introduce the roles of cenRNAs in centromere formation and function, kinetochore structure, accurate chromosome segregation, and pericentromeric heterochromatin assembly. Centromeric circular RNAs (circRNAs) and R-loops are rising stars in centromere function. CircRNAs have been successfully identifed in various species with the assistance of high-throughput sequencing and novel computational approaches for non-polyadenylated RNA transcripts. Centromeric R-loops can be identifed by the single-strand DNA ligation-based library preparation technique. But the molecular features and function of these centromeric R-loops and circRNAs are still being investigated. Conclusion In this review, we summarize recent fndings on the epigenetic regulation of cenRNAs across species, which would provide useful information about cenRNAs and interesting hints for further studies.

Universality of Finite-Size Corrections to Geometrical Entanglement in One-Dimensional Quantum Critical Systems

Xi-Jing Liu,Bing-Quan Hu,Sam Young Cho,Huan-Qiang Zhou,Qian-Qian Shi 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.7

Recently, the finite-size corrections to the geometrical entanglement per lattice site in the spin- 1/2 chain have been numerically shown to scale inversely with system size, and its prefactor b has been suggested to be possibly universal [Q-Q. Shi et al., New J. Phys. 12, 025008 (2010)]. As possible evidence of its universality, the numerical values of the prefactors have been confirmed analytically by using the Affleck-Ludwig boundary entropy with a Neumann boundary condition for a free compactified field [J-M. Stephan et al., Phys. Rev. B 82, 180406(R) (2010)]. However, the Affleck-Ludwig boundary entropy is not unique and does depend on conformally invariant boundary conditions. Here, we show that a unique Affleck-Ludwig boundary entropy corresponding to a finitesize correction to the geometrical entanglement per lattice site exists and show that the ratio of the prefactor b to the corresponding minimum groundstate degeneracy gmin for the Affleck- Ludwig boundary entropy is a constant for any critical region of the spin-1 XXZ system with the single-ion anisotropy, i.e., b/(2 log2 gmin) = −1. Previously studied spin-1/2 systems, including the quantum three-state Potts model, have verified the universal ratio. Hence, the inverse finite-size correction to the geometrical entanglement per lattice site and its prefactor b are universal for one-dimensional critical systems.

Possibility of Using DNA Chip Technology for Diagnosis of Human Papillomavirus

Liu, Cui-Hua,Ma, Wen-Li,Shi, Rong,Ou, Yang-Qian,Zhang, Bao,Zheng, Wen-Ling Korean Society for Biochemistry and Molecular Biol 2003 Journal of biochemistry and molecular biology Vol.36 No.4

To explore the application of DNA chip technology for the detection and typing of Human Papillomavirus (HPV), the HPV6, 11, 16 and 18 gene fragments were isolated and printed onto aminosilane-coated glass slides by a PixSys 5500 microarrayer as probes to prepare the HPV gene chips. HPV samples, after being labeled with fluorescent dye by restriction display PCR (RD-PCR) technology, were hybridized with the microarray, which was followed by scanning and analysis. The experimental condition for preparing the HPV gene chips was investigated, and the possibility of HPV genotyping using gene chips was discussed. The technique that was established in this study for preparing HPV gene chips is practical. The results of the present study demonstrated the versatility and inspiring prospect of using this technology to detect and genotype HPV.

The Genus Letrouitia (Letrouitiaceae: Lichenized Ascomycota) New to Cambodia

Shi, Haixia,Qian, Zigang,Wang, Xinyu,Liu, Dong,Zhang, Yanyun,Ye, Xin,Harada, Hiroshi,Wang, Lisong The Korean Society of Mycology 2015 Mycobiology Vol.43 No.2

The genus Letrouitia is newly recorded for Cambodia, including the four species as L. domingensis, L. leprolytoides, L. sayeri, and L. subvulpina. A brief description and illustrations are provided.

Ultra-sensitive graphene based mid-infrared plasmonic bio-chemical sensing using dielectric beads as a medium

Liu, Xiao,Zhang, Duan,Wu, Ye-Cun,Yang, Mei,Wang, Qian,Coileá,in, Cormac Ó,.,Xu, Hongjun,Yang, Chen,Abid, Mohamed,Abid, Mourad,Liu, Huajun,Chun, Byong Sun,Shi, Qingfan,Wu, Han-Chun Elsevier 2017 Carbon Vol.122 No.-

<P>Graphene is moving beyond the realm of simple electronic devices toward areas such as advanced biochemical sensing. The infrared (IR) response of graphene, characterized by collective long-lived charge-carrier oscillations, could be applied in IR-absorption spectroscopy, typically used for bio-chemical analysis. However, direct light absorption by propagating plasmons in graphene is forbidden due to the large momentum mismatch. Proposed methods to overcome this bottleneck come at a cost, the use of noble metal particles on graphene reduces the spectral bandwidth and nano-structuring graphene is expensive. Here, we propose a simple and cheap method to fabricate large scale ultra-sensitive graphene based mid-IR biosensors, by introducing dielectric beads to excite mid-IR range plasmons. Interference from waves scattered by the beads excite surface plasmon polaritons, which propagate several micrometers in graphene and enhance the interaction between the molecules and mid-IR light. This method opens an interesting window for the application of graphene in bio-chemical sensing. (C) 2017 Elsevier Ltd. All rights reserved.</P>

Evaluation of Solar Temperature Field under Different Wind Speeds for Shanghai 65 m Radio Telescope

Hongliang Qian,Deshen Chen,Feng Fan,Ye Liu,Shi-zhao Shen 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.2

The Shanghai 65 m radio telescope is currently the largest full range rotatable radio telescope in Asia. Gravity, wind and temperature are the three main factors which may have a bad effect on the reflector’s surface precision. To study the effect of the thermal deformation caused by daily non-uniform temperature fields on the surface precision of the main reflector, both the temperature field and its effect were studied in detail for two typical days (January 15th and July 15th). The method to simulate temperature fields was studied initially, considering heat conduction, solar radiation, shadowing, air convection, sky radiation and ground radiation. Then, an integral parametric thermal finite element model (FEM) of the telescope was established using the ANSYS thermal analysis module. Finally, the effect of non-uniform temperature fields on the surface precision of the main reflector was estimated in terms of the Root Mean Square (RMS) deformation based on temperature transient analysis. The proposed methods and conclusions drawn can provide valuable information for thermal design, thermal monitoring and thermal control of the Shanghai 65 m radio telescope and other similar giant antenna structures.

Intracellular Polysaccharide and its Antioxidant Activity by Pleurotus citrinopileatus SM-01

Su-Qian Wu,Shang-Long Gao,Hong-Hong Liu,Xin-Yi Sun,Long Hao,Le Jia,Li-Fei Pang,Shou-Hua Jia,Meng-Shi Jia 한국고분자학회 2013 Macromolecular Research Vol.21 No.6

The extraction parameters of intracellular polysaccharide (IPS) from Pleurotus citrinopileatus SM-01mycelia were optimized, and the in vitro and in vivo antioxidant activities of IPS were investigated. The optimum conditions of IPS extraction were predicted to be an ultrasonic treatment time of 664.09 s, precipitation time of 23.03h and pH 7.36, and IPS yield was estimated at 16.13%. The in vitro inhibition effects of IPS at a dosage of 5 g/L on the superoxide anion, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals were 73.96±4.62%, 69.2±4.37%,and 50.75±4.39%, respectively, which were 72.56±5.08%, 22.83±1.94%, and 43.93±3.26% higher than that of butylated hydroxytoluene (BHT), respectively. The reducing power of IPS was 0.9±0.07, 69.81±5.24% higher than that of BHT. The activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT) and alanine aminotransferase (ALT) in mice blood were 241.38±23.19, 454.95±42.39, 60.32±5.16, and 32.39±2.54 U/mL,respectively, and the malonaldehyde (MDA) level was 9.54±0.72 nmol/mL. The results provided a reference for the large-scale extraction of IPS by P. citrinopileatus SM-01 in industrial fermentation, suggesting that the IPS can be used as a potential antioxidant, which enhances adaptive immune responses.

Distinct mutations in MLH1 and MSH2 genes in Hereditary Non-polyposis Colorectal Cancer (HNPCC) families from China

( Wen Qian Wei ),( Fang Qi Liu ),( Lei Liu ),( Zuo Feng Li ),( Xiao Yan Zhang ),( Fan Jiang ),( Qu Shi ),( Xiao Yan Zhou ),( Wei Qi Sheng ),( San Jun Cai ),( Xuan Li ),( Ye Xu ),( Peng Nan ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.5

Hereditary non-polyposis Colorectal Cancer (HNPCC) is an autosomal dominant inheritance syndrome. HNPCC is the most common hereditary variant of colorectal cancer (CRC), which accounts for 2-5% CRCs, mainly due to hMLH1 and hMSH2 mutations that impair DNA repair functions. Our study aimed to identify the patterns of hMSH2 and hMLH1 mutations in Chinese HNPCC patients. Ninety-eight unrelated families from China meeting Amsterdam or Bethesda criteria were included in our study. Germline mutations in MLH1 and MSH2 genes, located in the exons and the splice-site junctions, were screened in the 98 probands by direct sequencing. Eleven mutations were found in ten patients (11%), with six in MLH1 (54.5%) and five in MSH2 (45.5%) genes. One patient had mutations in both MLH1 and MSH2 genes. Three novel mutations in MLH1 gene (c.157_160delGAGG, c.2157dupT and c.-64G>T) were found for the first time, and one suspected hotspot in MSH2 (c.1168C>T) was revealed. [BMB reports 2011; 44(5): 317-322]

Overexpression of miR-155-5p Inhibits the Proliferation and Migration of IL-13-Induced Human Bronchial Smooth Muscle Cells by Suppressing TGF-β-Activated Kinase 1/MAP3K7-Binding Protein 2

Yujia Shi,Xingli Fu,Qi Cao,Zhengdao Mao,Yi Chen,Yun Sun,Zhiguang Liu,Qian Zhang 대한천식알레르기학회 2018 Allergy, Asthma & Immunology Research Vol.10 No.3

Purpose: Molecular mechanisms leading to asthma is still ill-defined. Though the function of microRNAs (miRNAs) in asthma was previously reported, the involvement of miR-155 in important features of this disease remains unknown. The present study was designed to uncover the probable involvement of miR-155-5p in the proliferation and migration of IL-13-induced human bronchial smooth muscle cells (BSMCs) and the intrinsic regulatory mechanism. Methods: The effects of different concentrations of IL-13 on the proliferation and migration of BSMCs as well as the expression of miR-155-5p and its predicted target transforming growth factor (TGF)-β-activated kinase 1/MAP3K7-binding protein 2 (TAB2) were investigated. The effects of miR-155-5p on the proliferation and migration of interleukin (IL)-13-induced BSMCs was determined in vitro using BSMCs transfected with miR-155 mimic/inhibitor and induced by a high concentration of IL-13. The quantitative real-time polymerase chain reaction (qRT-PCR) was employed for determining the expression of miR-155-5p and TAB2. Western blotting was applied to analyze the expression of TAB2 at the protein level. Cell proliferation and migration were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Transwell assays, respectively. Results: The proliferation and migration of BSMCs were dose-dependently increased with IL-13 treatment. Contrariwise, IL-13 dose-dependently inhibited the expression of miR-155-5p in BSMCs. Mechanistic studies showed that inhibition of miR-155-5p further promoted the stimulatory effects of IL-13, whereas overexpression of miR-155 significantly inhibited these effects. In silico studies and luciferase reporter assays indicated that TAB2 was a negatively regulated miR-155-5p target. Conclusions: These results suggested that miR-155-5p-inhibit the IL-13-induced proliferation and migration of BSMCs by targeting TAB2 and that the IL-13/miR-155/TAB2 pathway could serve as a therapeutic target for pulmonary diseases, especially asthma.