Expression and characterization of RNA-dependent RNA polymerase of Ectropis obliqua virus

( Mei Juan Lin ),( Shan Ye ),( Yi Xiong ),( Da Wei Cai ),( Jia Min Zhang ),( Yuan Yang Hu ) 한국생화학분자생물학회 (구 한국생화학회) 2010 BMB Reports Vol.43 No.4

Replication of positive-strand RNA virus is mediated by a virus- encoded RNA-dependent RNA polymerase (RdRp). To study the replication of Ectropis obliqua virus (EoV), a newly identified insect virus belonging to the family Iflaviradae, we expressed the RNA polymerase domain in Escherichia coli and purified it on a Ni-chelating HisTrap affinity column. It is demonstrated that EoV RdRp initiated RNA synthesis in a primer- and poly (A)-dependent manner in vitro. Furthermore, the effect of primer concentration, temperature, metal ions (Mg2+, Mn2+, and K+) on enzymatic activity were determined. Our study represented a first step towards understanding the mechanism of EoV replication. [BMB reports 2010; 43(4): 284-290]

A Fractal Velocity Model for Ellis Fluid Flow in Porous Media

Mei-Juan Yun 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.8

In this paper, we present a fractal model for the flow velocity for an Ellis fluid based on thefractal properties of porous media. The proposed expression quantitatively describes the relationbetween the properties of the Ellis fluid and the parameters of the micro structure of the porousmedium. The model prediction is compared with experimental data, and good agreement betweenthem is found. The analytical expression reveals the physical principles for the flow of Ellis fluidsand other non-Newtonian fluids in porous media.

Eye Perception and Preference Difference between Different Emotional Content on TikTok and Twitter Platforms

Mei Juan Guo,권만우,황미경,주이모 한국멀티미디어학회 2023 The journal of multimedia information system Vol.10 No.2

Emotions are essential in today's complex social media information environments. Emotions can catch readers' attention and affect how users process information. This study explored the effect of emotional content on attention on different social media through an eye-tracking experiment. Participants (N=40) in this study read different emotional content. We measured the effects of emotions on visual attention by comparing the fixation times and counts of participants of two experimental groups: TikTok and Twitter. As a result of this study, the study found that the emotional and negative contents would draw more visual attention than their opposed contents (non-emotional, positive). Emotional content on social media attracted more attention, especially text with negative emotions. Negative information attracted more attention (compared to neutral and positive information). Our results revealed differences in visual attention towards contents with emotional contents. The study also suggested that the relationship between emotional and cognitive attention has little to do with social platforms. These findings have great implications for the study of emotional messages on social media. Therefore, this research is meaningful in a way that it suggests an objective examination through experiments with emotional content on social media.

A Study on Transnational Media Coverage of Sino-US Trade through Semantic Network Analysis

Mei Juan Guo,황미경,PengFei Zhu,주이모 한국멀티미디어학회 2023 The journal of multimedia information system Vol.10 No.2

This study was conducted to analyze the perspectives of transnational media reporting on Sino-US trade. News reports from Associated Press and Xinhua News Agency were collected from March 20, 2018, to October 31, 2018. Text mining and frequency analysis was performed by Python to examine significant keywords from the news reports. Eigenvector centralities and Modularity analysis were conducted by Gephi. QAP correlation analyses were conducted by Ucinet. As a result, Associated Press and Xinhua News Agency had different clusters. There was a significant correlation between the Xinhua News Agency Semantic Network and the Associated Press Semantic Network. This study supports the two perspectives of reporting from different aspects. Xinhua News Agency involved four sub-topics when reporting Sino-US trade frictions, namely China-related clusters, US-related clusters, trade-related clusters, and tariff-related clusters. The Associated Press involved three sub-topics, namely China-US Trade-related clusters, global economy-related clusters, and tariff-related clusters. Xinhua News Agency focused on China-related clusters, while Associated Press focused on Sino-US trade-related clusters. The network structure of Xinhua News Agency and AP shows a positive correlation, which to some extent indicates the global perspectives of Chinese and American media reporting. The division of the two network clusters and the difference in the choice and prominence of the words in the network indicates that the Chinese and American media are still affected by the political stance and culture when constructing the framework strategy. Based on these results, valuable implications are provided for media reporting across countries.

Examination of Antioxidative System’s Responses in the Different Phases of Drought Stress and During Recovery in Desert Plant Reaumuria soongorica (Pall.) Maxim

Juan Bai,Chun-Mei Gong,Kang Chen,Hong-Mei Kang,Gang Wang 한국식물학회 2009 Journal of Plant Biology Vol.52 No.5

The aim of this study was to test the protective roles of superoxide dismutases (SODs), guaiacol peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) against oxidative damage and their activities in different phases of the dry down process in Reaumuria soongorica (Pall.) Maxim. leaves. Drought stress was imposed during 100 consecutive days and rewatering after 16, 72, and 100 days. The concentration of hydrogen peroxide (H2O2), malondialdehyde, and SODs activities were elevated significantly with progressing drought stress. POD and CAT activities increased markedly in the early phase of drought and decreased significantly with further drought stress continuation, and POD activity was unable to recover after rewatering. Ascorbate, reduced glutathione, APX, and GR activities declined in the initial stages of drought process, elevated significantly with further increasing water deficit progression and recovered after rewatering. These results indicate that: (1) iron SODsremoving superoxide anion is very effective during the whole drought stress; (2) CAT scavenges H2O2 in the early phase of drought and enzymes of ascorbate–glutathione cycle scavenge H2O2 in further increasing drought stress; and (3) POD does not contribute to protect against oxidative damage caused by H2O2 under drought stress.

Streptomyces zhihengii sp. nov., isolated from rhizospheric soil of Psammosilene tunicoides

Huang, Mei-Juan,Fei, Jing-Jing,Salam, Nimaichand,Kim, Chang-Jin,Hozzein, Wael N.,Xiao, Min,Huang, Hai-Quan,Li, Wen-Jun Springer-Verlag 2016 Archives of microbiology Vol.198 No.8

<P>An actinomycete strain, designated YIM T102(T), was isolated from the rhizospheric soil of Psammosilene tunicoides W. C. Wu et C. Y. Wu collected from Lijiang, Yunnan Province, China. The taxonomic position of the new isolate was investigated by a polyphasic approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain YIM T102(T) belongs to the genus Streptomyces. Strain YIM T102(T) was most closely related to Streptomyces eurocidicus NRRL B-1676(T) with a pairwise 16S rRNA gene sequence similarity of 98.9 %. However, DNA-DNA relatedness value between strain YIM T102(T) and S. eurocidicus NBRC 13491(T) was found to be 37.8 +/- 1.8 %. The menaquinone composition detected for strain YIM T102(T) was MK-9 (H-6) and MK-9 (H-8), while the major fatty acids were summed feature 4 (38.0 %), anteiso-C-15:0 (13.1 %), iso-C-16:0 (10.1 %), summed feature 3 (9.8 %) and C-16:0 (9.0 %) and iso-C-15:0 (5.2 %). The whole-cell hydrolysates contained galactose, glucose, ribose and mannose, along with ll-diaminopimelic acid as the diagnostic diamino acid in the peptidoglycan. The DNA G+C content was 70.7 mol%. Strain YIM T102(T) also exhibited antagonistic activity against Alternaria alternata, Alternaria brassicae and Colletotrichum nicotianae Averna, based on the findings from the comparative analyses of phenotypic and genotypic characteristics; it is proposed that strain YIM T102 represents a novel species of the genus Streptomyces, for which the name Streptomyces zhihengii sp. nov. is proposed. The type strain is YIM T102(T) (=KCTC 39115(T) = DSM 42176(T) = CGMCC 4.7248(T)).</P>

Emodin-Provoked Oxidative Stress Induces Apoptosis in Human Colon Cancer HCT116 Cells through a p53-Mitochondrial Apoptotic Pathway

Xie, Mei-Juan,Ma, Yi-Hua,Miao, Lin,Wang, Yan,Wang, Hai-Zhen,Xing, Ying-Ying,Xi, Tao,Lu, Yuan-Yuan Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Emodin, a natural anthraquinone isolated from the traditional Chinese medicine Radix rhizoma Rhei, can induce apoptosis in many kinds of cancer cells. This study demonstrated that emodin induces apoptosis in human colon cancer HCT116 cells by provoking oxidative stress, which subsequently triggers a p53-mitochondrial apoptotic pathway. Emodin induced mitochondrial transmembrane potential loss, increase in Bax and decrease in Bcl-2 expression and mitochondrial translocation and release of cytochrome c to cytosol in HCT116 cells. In response to emodin-treatment, ROS increased rapidly, and subsequently p53 was overexpressed. Pretreatment with the antioxidant NAC diminished apoptosis and p53 overexpression induced by emodin. Transfecting p53 siRNA also attenuated apoptosis induced by emodin, Bax expression and mitochondrial translocation being reduced compared to treatment with emodin alone. Taken together, these results indicate that ROS is a trigger of emodin-induced apoptosis in HCT116 cells, and p53 expression increases under oxidative stress, leading to Bax-mediated mitochondrial apoptosis.

First report of Bradysia difformis (Diptera: Sciaridae) Damage to Phalaenopsis orchid in China

Qun Xin Han,Dong Mei Cheng,Juan Luo,Cui Zuan Zhou,Qing Sheng Lin,Mei Mei Xiang 한국응용곤충학회 2015 Journal of Asia-Pacific Entomology Vol.18 No.1

Phalaenopsis orchid is among the most valuable ornamental flowering plants in the world. Since visible damage substantially decreases its amenity, limited damage is allowed in its production. An unknown insect species (Diptera: Sciaridae)was found to cause serious damage to the seedling of the Phalaenopsis orchid in greenhouses in Guangdong, China. The insect occurred in high populations in almost all greenhouses that grow Phalaenopsis orchid and the number of sciarid adults trapped on a yellow sticky card could reach as many as 303 in 24 h. An effectivemanagement strategy on any pest requires an accurate identification. Therefore, it is urgent to identify this pest correctly to mitigate its damage to the industry. Damage to Phalaenopsis orchid and morphological characteristics of the pest was described in this study. Molecular analyses based on the 488-bp portion of the mitochondrialDNA fromthe cytochrome oxidase I(mt COI) regionwere conducted to supplementmorphological characteristics in identifying this pest. Bothmorphological characteristics and phylogenetic tree constructedwith mt COI genes identified this sciarid as Bradysia difformis Frey, 1948 (= Bradysia paupera Tuomikoski, 1960) (Diptera: Sciaridae). A literature search indicated that B. difformis has been a common pest of greenhouse and forestry nurseries in Europe and South Africa. Our study is the first record of B. difformis damaging Phalaenopsis orchid in China.

Enzymatic synthesis of novel isobavachalcone glucosides via a UDP-glycosyltransferase

Hong-Mei Li,이재경,Li-Juan Nie,Qiang Huo,Tao Ma,송재경,홍영수,Cheng-Zhu Wu 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.12

Glycosylation is often used to improve a natural product’s properties such as water solubility, chemical stability, pharmacological potency, and structure diversification. In this study, we studied the enzymatic synthesis of novel isobavachalcone glucosides using a UDP-glycosyltransferase (YjiC) from Bacillus licheniformis DSM-13. The chemical structures of compounds 1 and 2 were elucidated by spectroscopic techniques, including LC–MS, MS, and NMR. Meanwhile, the parameters of glycosylation reaction such as incubation time, UDP-glucose concentration, and pH of buffer were also optimized during this study. Furthermore, the compounds 1 and 2 exhibited weak anti-proliferative activities against five human cancer cell lines, with IC50 values ranging from 58.6 to 86.6 lM.

Increase of sn-2 positional pinolenic acid in triacylglycerol molecules through Lipozyme TLIM catalyzed interesterification

Xue Mei Zhu,Jung Ah Shin,Juan Jin,Jeung Hee Lee,Ki Taek Lee 한국식품저장유통학회 ( 구 한국농산물저장유통학회 ) 2009 한국식품저장유통학회 학술대회 Vol.2009 No.-