Diversity and Active Mechanism of Fengycin-Type Cyclopeptides from Bacillus subtilis XF-1 Against Plasmodiophora brassicae

( Xing Yu Li ),( Zi Chao Mao ),( Yue Hu Wang ),( Yi Xing Wu ),( Yue Qiu He ),( Chun Lin Long ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.3

Bacillus subtilis XF-1, a strain with demonstrated ability to control clubroot disease caused by Plasmodiophora brassicae, was studied to elucidate its mechanism of antifungal activity against P. brassicae. Fengycin-type cyclopeptides (FTCPs), a well-known class of compounds with strong fungitoxic activity, were purified by acid precipitation, methanol extraction, and chromatographic separation. Eight homologs of fengycin, seven homologs of dehydroxyfengycin, and six unknown FTCPs were characterized with LC/ESI-MS, LC/ESI-MS/MS, and NMR. FTCPs (250μg/ml) were used to treat the resting spores of P. brassicae (107/ml) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm (A260) and at 280 nm (A280) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be cleaved by the FTCPs of B. subtilis XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol.

Identification of putative carboxylesterase and aldehyde oxidase genes from the antennae of the rice leaffolder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae)

Yu-Xing Zhang,Wen-Long Wang,Mao-Ye Li,Shi-Guang Li,Su Liu 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.3

In insects, odorant-degrading enzymes (ODEs) play essential roles in the degradation of volatile odorants and maintenance of olfactory sensitivity. ODEs include several enzyme families with detoxification functions, such as carboxylesterases (CXEs) and aldehyde oxidases (AOXs). The rice leaffolder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae), is a serious rice insect pest in Asia. In this study, 18 putative CXE genes and four AOX genes were identified from the antennae of C. medinalis by retrieving a previously released transcriptome dataset. BLASTX searching and phylogenetic analyses showed that these genes are closely related to their respective orthologs in other lepidopteran species. Expression patterns of these genes were determined by reverse transcription- quantitative PCR (RT-qPCR). Four candidate genes, including three CmedCXEs (CmedCXE17, CmedCXE20 and CmedCXE24) and one CmedAOX (CmedAOX2) were antenna-enriched and considered potentially involved in odorant degradation. Our findings provide a comprehensive sequence resource and expression profiles of CXE and AOX genes in C. medinalis antennae, which may facilitate further studies of the odorant degradation mechanisms in this insect species.

Role of Convective Parameterization in Simulations of Heavy Precipitation Systems at Grey-Zone Resolutions - Case Studies

Xing Yu,이태영 한국기상학회 2011 Asia-Pacific Journal of Atmospheric Sciences Vol.47 No.2

We have investigated the role of convective parameterization in simulations of heavy precipitation systems at grey-zone (2-10 km)resolutions using an approach similar to that used in “observing system simulation experiment”. Simulations with a 1-km grid serve as benchmark simulations. The impacts of convective parameterization at greyzone resolutions (i.e., 3, 6, and 9 km) are then investigated. This study considers two heavy precipitation systems including one associated with a mesoscale cyclone generated over the Shandong Peninsula on 24-25 July 1991, and the other associated with a cloud cluster occurred on 15-16 July 2009. The present study indicates that convective parameterization does not affect much the simulations of the two heavy precipitation systems with 3-km grid size. However, it significantly affects simulations for grid sizes of 6 and 9 km. Simulations with the Kain-Fritsch scheme produce deficiencies such as relatively small heavy rainfall area, smaller maximum precipitation rate, wider area of weak precipitation, etc. Simulations without convective parameterization have also some negative effects such as the overprediction of area-averaged precipitation rate and others. A modified trigger function in the Kain-Fritsch scheme is found to improve the simulations of the heavy precipitation systems over the Korean Peninsula by reducing excessive trigger of convection, especially for simulations with 6- and 9- km grids.

2,1,3-Benzothiadiazole-5,6-dicarboxylicimide-Based Polymer Semiconductors for Organic Thin-Film Transistors and Polymer Solar Cells

Yu, Jianwei,Ornelas, Joshua Loroñ,a,Tang, Yumin,Uddin, Mohammad Afsar,Guo, Han,Yu, Simiao,Wang, Yulun,Woo, Han Young,Zhang, Shiming,Xing, Guichuan,Guo, Xugang,Huang, Wei American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.48

<P>A series of polymer semiconductors incorporating 2,1,3-benzothiadiazole-5,6-dicarboxylicimide (BTZI) as strong electron-withdrawing unit and an alkoxy-functionalized head-to-head linkage containing bithiophene or bithiazole as highly electron-rich co-unit are designed and synthesized. Because of the strong intramolecular charge transfer characteristics, all three polymers BTZI-TRTOR (P1), BTZI-BTOR (P2), and BTZI-BTzOR (P3) exhibit narrow bandgaps of 1.13, 1.05, and 0.92 eV, respectively, resulting in a very broad absorption ranging from 350 to 1400 nm. The highly electron-deficient 2,1,3-benzothiadiazole-5,6-dicarboxylicimide and alkoxy-functionalized bithiophene (or thiazole) lead to polymers with low-lying lowest unoccupied molecular orbitals (-3.96 to -4.28 eV) and high-lying highest occupied molecular orbitals (-5.01 to -5.20 eV). Hence, P1 and P3 show substantial and balanced ambipolar transport with electron mobilities/hole mobilities of up to 0.86/0.51 and 0.95/0.50 cm(2) V-1 s(-1), respectively, and polymer P2 containing the strongest donor unit exhibited unipolar p-type performance with an average hole mobility of 0.40 cm(2) V-1 s(-1) in top-gate/bottom-contact thin-film transistors with gold as the source and drain electrodes. When incorporated into bulk heterojunction polymer solar cells, the narrow bandgap (1.13 eV) polymer P1 shows an encouraging power conversion efficiency of 4.15% with a relatively large open-circuit voltage of 0.69 V, which corresponds to a remarkably small energy loss of 0.44 eV. The power conversion efficiency of P1 is among the highest reported to date with such a small energy loss in polymer:fullerene solar cells.</P>

A New Quorum-Sensing Inhibitor Attenuates Virulence and Decreases Antibiotic Resistance in Pseudomonas aeruginosa

Yu-Xiang Yang,Zhen-Hua Xu,Yu-Qian Zhang,Jing Tian,Li-Xing Weng,Lian-Hui Wang 한국미생물학회 2012 The journal of microbiology Vol.50 No.6

Quorum sensing (QS) has been a novel target for the treatment of infectious diseases. Here structural analogs of Pseudomonas aeruginosa autoinducer N-acyl homoserine lactone (AHL) were investigated for QS inhibitor (QSI) activity and a novel QSI was discovered, N-decanoyl-L-homoserine benzyl ester (C2). Virulence assays showed that C2 downregulated total protease and elastase activities, as well as the production of rhamnolipid, that are controlled by QS in P.aeruginosa wild-type strain PAO1 without affecting growth. C2 was also shown to inhibit swarming motility of PAO1. Using a microdilution checkerboard method, we identified synergistic interactions between C2 and several antibiotics, tobramycin, gentamycin, cefepime, and meropenem. Data from real-time RT-PCR suggested that C2 inhibited the expression of lasR (29.67%), lasI (21.57%), rhlR (28.20%), and rhlI (29.03%).

Cues of intraguild predators (Harmonia axyridis) and different temperatures alter foraging and oviposition strategies of the parasitoid Aphidius gifuensis

Yu Xing-Lin,Feng Yi,Liu Tong-Xian,Qiu Bao-Li 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.2

Organisms live in complex systems where they simultaneously balance responses to multiple factors. Insects are dealing with indirect pressures from predators under the influence of temperature. Currently, little is known about how they balance these factors. Under laboratory conditions, we investigated the effects of the predator Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) cues and temperature (23, 28, and 33 ◦ C) on the foraging and oviposition behavior of the parasitoid Aphidius gifuensis Ashmead (Hymenoptera: Braconidae) using the aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) as a host. In all trials, the frequency and duration of stinging, walking, or stationary behavior of A. gifuensis were not influenced by H. axyridis cues. However, in trials with predator cues, A. gifuensis produced less offspring than trials without predator cues. On the other hand, the frequency of A. gifuensis stinging, walking, or stationary behavior, and the number of A. gifuensis larvae increased with rising temperature. Specially, when the predator cues were present, parasitoid responded to rising tem peratures by increasing frequency of each behavior and an increase in offspring number. Our findings indicate that A. gifuensis might show flexible foraging and oviposition behavior in response to H. axyridis associated cues and different temperatures. Thus, the effects of both temperature and H. axyridis cues should be considered when assessing the foraging outcomes of A. gifuensis prior to combining these two enemies in aphid management practice.

Strategic Environmental Policy and Environmental Tariffs

( Yu Qing Xing ) 세종대학교 경제통합연구소 (구 세종대학교 국제경제연구소) 2006 Journal of Economic Integration Vol.21 No.4

This paper uses a three-stage game to analyze how environmental tariffs affect the strategic behavior of a government in designing environmental policy. The game is based on an international duopoly model with detrimental externality in production and asymmetric environmental policies between two countries. It shows that the welfare effect of the foreign country`s strategic environmental policy on the home country is ambiguous. In the circumstance that the home country would be worse off due to the lenient environmental policy of the foreign country, there exists an optimal environmental tariff. If the home country imposes the optimal tariff on the pollution-intensive imports, any deviation from the first best environmental policy by the foreign country would make the home country better off. In addition, the implementation of the environmental tariff would mitigate the motivation of the foreign country to pursue strategic environmental policy, and drive the lenient environmental standard toward the efficient level. The theoretical results imply that, in an open economy with non-harmonized environmental standards, imposing environmental tariffs on imports from the countries with lax environmental regulations would correct the adverse welfare effect, and more importantly induce the upward harmonization on environmental policy across countries.

The gridding of MOS for high resolution forecasting

Xing YU,Seon Ki PARK,Yong-Hee LEE,Kwang-Deuk AHN,Sung-Ho CHOO 한국기상학회 2011 한국기상학회 학술대회 논문집 Vol.2011 No.10-2

As the numerical weather prediction (NWP) models became more accurate, model output statistics (MOS) follow that trend. The Korean Meteorological Adminstration (KMA) descided to import the Unified Model (UM) as a next-generation NWP system since 2007. The KLAPS (Korea Local Analysis and. Prediction System) with 5 km resolution is used as the observation to verify the 12 km UM forecast. Four surface variables are verified – temperature, relative humidy, wind speed and wind direction. The MOS forecast are based on a meta-heuristic algorithm – harmony search (HS) and 80 potential varibles derived from the UM forecasts. The MOS process is as follows: 1) to intepolate the 12 km UM output to the corresponding KLAPS 5 km grids. 2) to derive 80 potential predictants. 3) to minimize the difference between the MOS forecasts and the KLAPS analysis fields. The coefficient tuning process is done by the HS method. The MOS is seperated for 4 seasons, and the traning period is 2007-2009. The UM was initilized twice a day (00 and 12 UTC), and 21 valid forecast times are from 6 to 66 hours. Therefore, there exist 2*21 equations for a given grid and predictor. Statistic scores show that MOS forecasts are superior to the UM forecasts for most grids.

Isoliquiritigenin suppresses tumor necrosis factor-a-induced inflammation via peroxisome proliferator-activated receptor-c in intestinal epithelial cells

Xing Yu Jin,Dong Hwan Sohn,이성희 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.10

Intestinal epithelial cells play an important role in the mucosal immune reaction in inflammatory bowel diseases via the expression of inflammatory mediators, such as cyclooxygenase-2 (COX-2) and intercellular adhesion molecule-1 (ICAM-1). Isoliquiritigenin (ISL; 4,20,40-trihydroxychalcone) has been shown to exhibit antiinflammatory properties in murine macrophage cells. In the present study, we evaluated the anti-inflammatory properties of ISL in intestinal epithelial cells and determined its mechanism of action. ISL suppressed the expression of COX-2 and ICAM-1 in tumor necrosis factor-a (TNF-a) stimulated intestinal epithelium HT-29 cells. It also induced peroxisome proliferator-activated receptor-c (PPARc) protein expression. Moreover, using a PPARc antagonist, GW9662, we found that the regulation of COX2 and ICAM-1 expression by ISL in TNF-a-stimulated HT29 cells is mediated via PPARc expression. A signal transduction study revealed that ISL significantly attenuates TNF-a-mediated JNK phosphorylation. ISL-induced ERK1/2 phosphorylation was associated with PPARc expression. Additionally, both the inhibitory effect on COX-2 and ICAM-1 expression and the induction of PPARc expression by ISL in TNF-a-stimulated HT-29 cells was abolished by the addition of U0126, a specific ERK1/2 inhibitor. Collectively, ISL-induced PPARc mediated, at least partially, the suppression of intestinal inflammation. These results suggest that ISL may be beneficial for the treatment of mucosal inflammation.

Ferroelectric Behaviors of P(VDF/TrFE) Copolymer Ultrathin Films and Its Dependence on Preparation Methods

Xing Yu Jin,Choi Ki Woon,Kim Kap Jin,Han Sup Lee 한국고분자학회 2006 한국고분자학회 학술대회 연구논문 초록집 Vol.2006 No.10