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The genome of the cucumber, Cucumis sativus L.
Huang, Sanwen,Li, Ruiqiang,Zhang, Zhonghua,Li, Li,Gu, Xingfang,Fan, Wei,Lucas, William J,Wang, Xiaowu,Xie, Bingyan,Ni, Peixiang,Ren, Yuanyuan,Zhu, Hongmei,Li, Jun,Lin, Kui,Jin, Weiwei,Fei, Zhangjun,Li Nature Publishing Group 2009 Nature genetics Vol.41 No.12
Cucumber is an economically important crop as well as a model system for sex determination studies and plant vascular biology. Here we report the draft genome sequence of Cucumis sativus var. sativus L., assembled using a novel combination of traditional Sanger and next-generation Illumina GA sequencing technologies to obtain 72.2-fold genome coverage. The absence of recent whole-genome duplication, along with the presence of few tandem duplications, explains the small number of genes in the cucumber. Our study establishes that five of the cucumber's seven chromosomes arose from fusions of ten ancestral chromosomes after divergence from Cucumis melo. The sequenced cucumber genome affords insight into traits such as its sex expression, disease resistance, biosynthesis of cucurbitacin and 'fresh green' odor. We also identify 686 gene clusters related to phloem function. The cucumber genome provides a valuable resource for developing elite cultivars and for studying the evolution and function of the plant vascular system.
Silencing IL-23 expression by a small hairpin RNA protects against asthma in mice
Li, Yanchun,Sun, Meng,Cheng, Huanji,Li, Shanyu,Liu, Li,Qiao, Hongmei,Hua, Shucheng,Lu, Jirong Korean Society for Biochemistry and Molecular Bion 2011 Experimental and molecular medicine Vol.43 No.4
To determine the impact of IL-23 knockdown by RNA interference on the development and severity of ovalbumin (OVA)-induced asthmatic inflammation, and the potential mechanisms in mice, the IL-23-specific RNAi-expressing pSRZsi-IL-23p19 plasmid was constructed and inhaled into OVA-sensitized mice before each challenge, as compared with that of control mice treated with alum or budesonide. Inhalation of the pSRZsi-IL-23p19, significantly reduced the levels of OVA-challenge induced IL-23 in the lung tissues by nearly 75%, determined by RT-PCR. In addition, knockdown of IL-23 expression dramatically reduced the numbers of eosinophils and neutrophils in BALF and mitigated inflammation in the lungs of asthmatic mice. Furthermore, knockdown of IL-23 expression significantly decreased the levels of serum IgE, IL-23, IL-17, and IL-4, but not IFN${\gamma}$, and its anti-inflammatory effects were similar to or better than that of treatment with budesonide in asthmatic mice. Our data support the notion that IL-23 and associated Th17 responses contribute to the pathogenic process of bronchial asthma. Knockdown of IL-23 by RNAi effectively inhibits asthmatic inflammation, which is associated with mitigating the production of IL-17 and IL-4 in asthmatic mice.
Genome Shuffling of Lactobacillus brevis for Enhanced Production of Thymidine Phosphorylase
Hongmei Li,Fang Xue,Weijie Wang,Baozhen Chen 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.2
Thymidine phosphorylase (TPase) plays a vital role in the biosynthesis of nucleosides and their analogs which have tremendous potential in antiviral and anticancer therapies. In this study, genome shuffling was applied to develop new strains of Lactobacillus brevis with an enhanced production of TPase. The parent organisms were mutated using ultraviolet (UV) irradiation and were shuffled by recursive pool-wise protoplast fusion. The parent protoplasts of each cycle were inactivated by UV irritation for 50 min or by heating at 60°C for 60 min. A rapid and efficient pre-screening method for determining L. brevis fusants with increased TPase production was established by adding appropriate concentrations of substrate thymidine and potassium phosphate to the culture broth based on significant differences in the absorption spectra of substrate thymidine and its product, thymine, in alkaline solution at 290 nm. Strains F3-19 and F3-36 showed high TPase activity and favorable hereditary stability and were screened out through three rounds of recursive protoplast fusion. The increase in the TPase activity of F3-19 and F3-36 was 252.6 and 260.5%, respectively, in comparison with the wild type.
Model-Free Adaptive Integral Backstepping Control for PMSM Drive Systems
Li, Hongmei,Li, Xinyu,Chen, Zhiwei,Mao, Jingkui,Huang, Jiandong The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5
A SMPMSM drive system is a typical nonlinear system with time-varying parameters and unmodeled dynamics. The speed outer loop and current inner loop control structures are coupled and coexist with various disturbances, which makes the speed control of SMPMSM drive systems challenging. First, an ultra-local model of a PMSM driving system is established online based on the algebraic estimation method of model-free control. Second, based on the backstepping control framework, model-free adaptive integral backstepping (MF-AIB) control is proposed. This scheme is applied to the permanent magnet synchronous motor (PMSM) drive system of an electric vehicle for the first time. The validity of the proposed control scheme is verified by system simulations and experimental results obtained from a SMPMSM drive system bench test.
Fault-tolerant analysis of two boost inverters for open-end winding induction motor drives
Li, Chunjie,Wang, Guifeng,Li, Hongmei,Li, Fei,Xia, Zhenglong,Liu, Zhan The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.4
An open-end winding induction motor drive system fed by two boost inverters with fault-tolerant capability is presented to improve the reliability and safety of the drive system. The boost inverters consist of an impedance-source network and a two-level inverter. It can realize the boost/buck function. An analysis of its fault-tolerance is presented in detail. Short circuits and open circuits are commonly considered as the two main types of faults. Therefore, the fault types of the dual boost inverters are analyzed and diagnosed. Then, two different fault-tolerant schemes are presented. The presented fault-tolerant inverters are restructured through the power switch itself. In addition, different SVPWM methods are addressed. A simulation model and an experimental platform are constructed. Simulation and experimental results verify the fault tolerance of the drive system.
Sustained Oscillation of an Inverter - Fed Induction Motor Drive System and its Stabilization
Hongmei Li,Takashi Hikihara 대한전기학회 2006 Journal of Electrical Engineering & Technology Vol.1 No.1
The sustained oscillation of rotor speed is often experienced in PWM inverter induction motor (IM) drive systems. In this paper the oscillation is investigated from the point of view of Hopf bifurcation theory. The sufficient and necessary conditions for existence of limit cycle are introduced to determine the bifurcation set in the stator voltage versus stator frequency plane. According to the conditions it is clarified that the bifurcation set inherently exists in the instable operation of 1M. Moreover, it is numerically shown that the V/f curve can be adjusted to stabilize the sustained oscillation of rotor speed.
Controllable synthesis of zone-distributed Pd over CeO2–ZrO2/Al2O3 as advanced three-way catalyst
Li Lan,Shanhu Chen,Hongmei Li,Hanmei Li,Wanxia Wu,Jie Deng,Yaoqiang Chen 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.58 No.-
Two optimally designed catalysts (Ce0.7Zr0.3O2/Pd/Al2O3, Pd/Ce0.7Zr0.3O2/Pd/Al2O3) were synthesized and compared with conventional Pd/Ce0.7Zr0.3O2/Al2O3. The characterization results reveal that for Pd/Ce0.7Zr0.3O2/Al2O3, Pd species undergo severe agglomeration and encapsulation during thermal aging process, leading to dramatic catalyst deactivation. While for the two optimized catalysts, some Pd species initially distributed on Al2O3 would migrate to the surface of CexZr1−xO2(CZ) grains upon aging treatment, resulting in enhanced Pd–CZ interaction, thus the two aged samples possess higher dispersion, larger amount of oxidized Pd2+ species and more oxygen vacancies compared with conventional Pd/Ce0.7Zr0.3O2/Al2O3-a. Consequently, modified reducibility and improved three-way catalytic performance are obtained, especially for Pd/Ce0.7Zr0.3O2/Pd/Al2O3-a.
Li Lan,Jinfeng Wang,Shanhu Chen,Dacheng Li,Hongmei Li,Dayu Liu,Wei Wang,Yaoqiang Chen 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.71 No.-
In this work, an advanced Rh/CeO2–ZrO2 (Rh/CZ) three-way catalyst was synthesized with the assistanceof monoethanolamine. Compared with conventional Rh/CZ, the dispersion and oxidation state of Rhspecies, as well as the hydrothermal aging resistance are remarkably modified. That is, upon agingtreatment, conventional Rh/CZ undergoes severe agglomeration of Rh species and formation of largeamount of reduction-resistive RhO2, resulting in serious catalyst deactivation. Fortunately, after theintroduction of monoethanolamine, the sintering of Rh species and transformation into inactive RhO2upon aging are effectively suppressed. Consequently, improved reducibility and advanced three-waycatalytic activity are achieved for the modified catalyst.
Model-Free Adaptive Integral Backstepping Control for PMSM Drive Systems
Hongmei Li,Xinyu Li,Zhiwei Chen,Jingkui Mao,Jiandong Huang 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5
A SMPMSM drive system is a typical nonlinear system with time-varying parameters and unmodeled dynamics. The speed outer loop and current inner loop control structures are coupled and coexist with various disturbances, which makes the speed control of SMPMSM drive systems challenging. First, an ultra-local model of a PMSM driving system is established online based on the algebraic estimation method of model-free control. Second, based on the backstepping control framework, modelfree adaptive integral backstepping (MF-AIB) control is proposed. This scheme is applied to the permanent magnet synchronous motor (PMSM) drive system of an electric vehicle for the first time. The validity of the proposed control scheme is verified by system simulations and experimental results obtained from a SMPMSM drive system bench test.
Li, Chunjie,Wang, Guifeng,Li, Fei,Li, Hongmei,Xia, Zhenglong,Liu, Zhan The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4
This paper proposes a fault-tolerant control strategy with finite control set model predictive control (FCS-MPC) based on hierarchical optimization for five-level H-bridge neutral-point-clamped (5L-HNPC) inverter-fed induction motor drives. Fault-tolerant operation is analyzed, and the fault-tolerant control algorithm is improved. Adopting FCS-MPC based on hierarchical optimization, where the voltage is used as the controlled objective, called model predictive voltage control (MPVC), the postfault controller is simplified as a two layer control. The first layer is the voltage jump limit, and the second layer is the voltage following control, which adopts the optimal control strategy to ensure the current following performance and uniqueness of the optimal solution. Finally, simulation and experimental results verify that 5L-HNPC inverter-fed induction motor drives have strong fault tolerant capability and that the FCS-MPVC based on hierarchical optimization is feasible.