Sclareol production in the moss Physcomitrella patens and observations on growth and terpenoid biosynthesis

Xi-Wu Pan,Lei Han,Yu-Hua Zhang,Dong-Fang Chen,Henrik Toft Simonsen 한국식물생명공학회 2015 Plant biotechnology reports Vol.9 No.3

The moss Physcomitrella patens was engineered to produce the diterpenoid sclareol, an important precursor for the synthesis of ambergris substitutes for the perfume industry. The best total yield of sclareol was 2.84 mg/g dry weight (2.28 mg/l culture) obtained after 18 days of cultivation in liquid media (extracted from both media and cell pellet). The two active sclareol synthase genes were integrated in a random fashion, and linked with the ribosomal skip 2A under the control of the CaMV 35S promoter. We conclude that moss can produce sclareol and utilize the ribosomal skip 2A. In addition, we observed growth impairment in all our sclareol-producing lines and moss lines knocked out in the endogenous diterpene synthase (copalyl/kaurene synthase—PpCPS/KS). A RT-PCR study, with ubiquitin as the best reference gene, showed that there was a down-regulation of the transcription of the terpenoid biosynthetic genes in the PpCPS/KS knock out moss. This down-regulation was recovered by the introduction of the two sclareol synthases, suggesting that the regulation of the general terpenoid biosynthesis is very flexible and can be amended in future biotechnological engineering.

The Top-K QoS-aware Paths Discovery for Source Routing in SDN

( Xi Chen ),( Junlei Wu ),( Tao Wu ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.6

Source routing is the routing scheme that arranges the whole path from source to target at the origin node that may suit the requirements from the upper layer applications’ perspective. The centralized control in SDN (Software-Defined Networking) networks enables the awareness of the global topology at the controller. Therefore, augmented source routing schemes can be designed to achieve various purposes. This paper proposes a source routing scheme that conducts the top-K QoS-aware paths discovery in SDN. First, the novel non-invasive QoS over LLDP scheme is designed to collect QoS information based on LLDP in a piggyback fashion. Then, variations of the KSP (K Shortest Paths) algorithm are derived to find the unconstrained/constrained top-K ranked paths with regard to individual/overall path costs, reflecting the Quality of Service. The experiment results show that the proposed scheme can efficiently collect the QoS information and find the top-K paths. Also, the performance of our scheme is applicable in QoS-sensitive application scenarios compared with previous works.

Design-Oriented Stability of Outer Voltage Loop in Capacitor Current Controlled Buck Converters

Xi Zhang,Zhongwei Zhang,Bocheng Bao,Han Bao,Zhimin Wu,Kaiwen Yao,Jing Wu 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4

Due to the inherent feedforward of load current, capacitor current (CC) control shows a fast transient response that makes itsuitable for the power supplies used in various portable electronic devices. However, considering the effect of the outer voltageloop, the stable range of the duty-cycle is significantly diminished in CC controlled buck converters. To investigate the stabilityeffect of the outer voltage loop on buck converters, a CC controlled buck converter with a proportion-integral (PI) compensatoris taken as an example, and its second-order discrete-time model is established. Based on this model, the instability caused by theduty-cycle is discussed with consideration of the outer voltage loop. Then the dynamical effects of the feedback gain of the PIcompensator and the equivalent series resistance (ESR) of the output capacitor on the CC controlled buck converter with a PIcompensator are studied. Furthermore, the design-oriented closed-loop stability criterion is derived. Finally, PSIM simulationsand experimental results are supplied to verify the theoretical analyses.

Thermodynamic performance analysis of a coupled transcritical and subcritical organic Rankine cycle system for waste heat recovery

Xi-Wu Gong,Xiao-Qiong Wang,You-Rong Li,Chun-Mei Wu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.7

We present a novel coupled organic Rankine cycle (CORC) system driven by the low-grade waste heat, which couples a transcriticalorganic Rankine cycle with a subcritical organic Rankine cycle. Based on classical thermodynamic theory, a detailed performance analysison the novel CORC system was performed. The results show that the pressure ratio of the expander is decreased in the CORC and theselection of the working fluids becomes more flexible and abundant. With the increase of the pinch point temperature difference of theinternal heat exchanger, the net power output and thermal efficiency of the CORC all decrease. With the increase of the critical temperatureof the working fluid, the system performance of the CORC is improved. The net power output and thermal efficiency of the CORCwith isentropic working fluids are higher than those with dry working fluids.

Recent Studies Conducted in Environmental Health Field in KMC : Behavioral Functional Tests and Genotoxicity Detection in Rats after Exposure to Low Density 1800MHz(CW)-RF

( Xi Nan Wu ),( Tian Ming Cheng ),( Ping Liu ) 한국환경보건학회(구-한국환경위생학회) 2004 Current Challenges and Advances in Environmental H Vol.- No.-

The role of WRKY47 gene in regulating selenium tolerance in Arabidopsis thaliana

Xi Wu,Manzhi Tao,Yun Meng,Xiangyu Zhu,Liangwen Qian,Alia Shah,Wei Wang,Shuqing Cao 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.1

Selenium stress has a serious impact on the growth of plants. However, the available understanding on the mechanism of Se stress response is still insufficient. In this study, we found that the WRKY47 gene plays an important role in maintaining Se homeostasis and tolerance in Arabidopsis thaliana. Expression of WRKY47 is induced by Se stress. The wrky47 mutants are sensitive to Se stress, and this sensitivity is associated with a decrease in the transcription levels of Se-detoxify genes HMT1 and HMT3. Surprisingly, the WRKY47-overexpression lines also showed increased sensitivity to Se stress and had increased Se content; this correlates to an increase in the transcription level of Se-uptake gene PHT1;4 but not Se-detoxify genes HMT1 and HMT3. Our results suggest that gain- and loss-of-function mutations in WRKY47 enhance the sensitivity of A. thaliana plants to Se stress through different mechanisms.

Mitigation of Sub-synchronous Oscillation Caused by Thyristor Controlled Series Capacitor Using Supplementary Excitation Damping Controller

Wu, Xi,Jiang, Ping,Chen, Bo-Lin,Xiong, Hua-Chuan Journal of International Conference on Electrical 2012 Journal of international Conference on Electrical Vol.1 No.2

The Test Signal Method is adopted to analyze the impact of thyristor controlled series capacitor (TCSC) on sub-synchronous oscillation. The results show that the simulation system takes the risk of Sub-synchronous Oscillation (SSO) while the TCSC is operating in the capacitive region. A supplementary excitation damping controller (SEDC) is used to mitigate SSO caused by the TCSC. A new optimization method which is aimed for optimal phase compensation is proposed. This method is realized by using the particle swarm optimization (PSO) algorithm. The simulation results show that the SEDC designed by this method has superior suitability, and that the secure operation scope of the TCSC is greatly increased.

Design-Oriented Stability of Outer Voltage Loop in Capacitor Current Controlled Buck Converters

Zhang, Xi,Zhang, Zhongwei,Bao, Bocheng,Bao, Han,Wu, Zhimin,Yao, Kaiwen,Wu, Jing The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4

Due to the inherent feedforward of load current, capacitor current (CC) control shows a fast transient response that makes it suitable for the power supplies used in various portable electronic devices. However, considering the effect of the outer voltage loop, the stable range of the duty-cycle is significantly diminished in CC controlled buck converters. To investigate the stability effect of the outer voltage loop on buck converters, a CC controlled buck converter with a proportion-integral (PI) compensator is taken as an example, and its second-order discrete-time model is established. Based on this model, the instability caused by the duty-cycle is discussed with consideration of the outer voltage loop. Then the dynamical effects of the feedback gain of the PI compensator and the equivalent series resistance (ESR) of the output capacitor on the CC controlled buck converter with a PI compensator are studied. Furthermore, the design-oriented closed-loop stability criterion is derived. Finally, PSIM simulations and experimental results are supplied to verify the theoretical analyses.

중국 저칼로리 젤리 제품의 패키지 디자인 시각요소 분석 연구

오연희 ( Wu¸ Yan Xi ),김희현 ( Kim¸ Hee Hyun ) 한국기초조형학회 2021 기초조형학연구 Vol.22 No.4

생활수준의 향상에 따라 사람들의 건강 의식이 높아지면서 저칼로리·저지방 제품을 내놓는 브랜드도 늘고 있다. 본 연구의 목적은 향후에 저칼로리 제품 특성을 소비자에게 더 잘 표현할 수 있는 미래의 디자인 방향을 제시하는 것이다. 연구 방법은 중국 최대 온라인 쇼핑몰 ‘타오바오’(taobao)에서 판매 상위 10개 브랜드 제품의 패키지 디자인 시각 요소 중 브랜드 로고(logo), 컬러(color), 일러스트(illustration), 레이아웃(layout) 이 네 가지 요소를 중심으로 저칼로리 젤리 제품의 패키지 디자인 특징을 분석하고 설문조사를 통해 리커트 5점 척도를 활용하여 저칼로리 제품의 패키지 디자인에 대한 소비자의 의견을 수집하고 분석하는 것이다. 연구 결과는 중국 시장에서 판매되는 저칼로리 젤리 제품의 패키지에 로고의 위치가 뚜렷하지 않아 브랜드 이름이 상대적으로 잘 보이지 않고, 일러스트의 이미지 구성요소가 비슷해 브랜드별로 패키지 디자인에서도 차별성이 약한 특징이 있었다. 설문 결과에 따르면 응답자들이 제품 색상 차이가 크게 나타나고 숫자로 식별하기 용이한 디자인을 더 선호했다. 또한, 저칼로리 젤리 제품과 일반 젤리 제품은 패키지 디자인 요소가 차별성이 약하고 일부 제품은 저칼로리 제품의 특성을 소비자에게 제대로 전달하지 못한 것도 단점이다. 응답자들은 저칼로리 특성을 드러내는 레이아웃이 저칼로리 젤리 제품과 일반 젤리 제품을 구분하는 중요한 요인으로 생각하고 있었다. 따라서 소비자에게 ‘저칼로리’ 정보를 더 잘 전달하여 구매를 유도하기 위해 향후 저칼로리 젤리 브랜드의 패키지 디자인은 저칼로리 특성을 더 잘 보완할 수 있는 레이아웃 패키지 디자인에 더욱 집중해야 한다. With the improvement of living standards, people’s health awareness is also increasing, and the number of brands launching low-calorie and low-fat products on the market is also increasing. The purpose of this study is to provide future design directions that can better express the characteristics of low-calorie products to consumers. The research method is to analyze the packaging design characteristics of low-calorie jelly products based on the brand logo, color, illustration, and layout among the visual elements of the packaging design of the top 10 brand products sold on “Taobao”, the largest online shopping mall in China. Through questionnaire survey and 5-point Likert scale, collect and analyze consumer feedback on packaging design of low-calorie products. The results of the study show that the package of low-calorie jelly products sold in the Chinese market was not clearly located, so the brand name was relatively hard to see, and the image components of the illustration were similar, so the difference was weak in package design. According to the results of the questionnaire survey, respondents prefer designs with large color differences and easier identification through numbers. In addition, the packaging design elements of low-calorie jelly and ordinary jelly products are relatively weak, and the failure of some products to convey the characteristics of low-calorie products to consumers is also a major disadvantage. Respondents believe that the typography that highlights low-calorie features is an important factor in distinguishing low-calorie jelly products from ordinary jelly products. Therefore, in order to better convey the “low-calorie” message to consumers and guide consumers to make purchases, future low-calorie jelly brands should focus more on better improving the outer packaging design with low-calorie features.

The Therapeutic Effects of Tectorigenin on Chemically Induced Liver Fibrosis in Rats and an Associated Metabonomic Investigation

Xing-Xi Gao,Jun-Hua Wu,Da-Hua Shi,Yun-Xi Chen,Jiang-Tao Cui,Yu-Rong Wang,Chun-Ping Jiang 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.8

The aim of this study was to investigate the effects of tectorigenin on chemically induced liver fibrosis in rats. Liver fibrosis was induced in rats with carbon tetrachloride, a diet high in fat, cholesterol and alcohol in the drinking water. Our results indicate that tectorigenin treatment significantly inhibited the increases in the activities of alanine aminotransferase (ALT),aspartate aminotransferase (AST) and the increases in the serum levels of hyaluronate (HA), laminin (LN) and procollagen III N-terminal peptide (PIIIP); tectorigenin treatment also significantly inhibited the increases in the amount of collagen in the livers of the fibrogenic rats. Chemically induced liver fibrosis caused a drop in the serum albumin concentration and a decrease in the ratio of albumin to globulin (A/G). Tectorigenin caused a remarkable increase at a dose of 30 mg/kg, but only a slight increase at the lower doses. Tectorigenin was also able to inhibit the increase in the liver lipid peroxidation (LPO), as well as the decrease in the activities of liver superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), caused by liver fibrosis. In addition, we present a related metabolic profile determined, using a 1H NMR spectroscopy and multivariate pattern recognition techniques. The results were consistent with the pathological examination, liver function analysis and liver fibrosis marker analysis. Furthermore, tectorigenin does not cause acute toxicity.