Effects of Maleic Anhydride Grafted Ethylene/Vinyl Acetate Copolymer (EVA)on the Properties of EVA/Silica Nanocomposites

Thai Hoang,Nguyen Thuy Chinh,Nguyen Thi Thu Trang,To Thi Xuan Hang,Dinh Thi Mai Thanh,Dang Viet Hung,하창식,Maëlenn Aufray 한국고분자학회 2013 Macromolecular Research Vol.21 No.11

Ternary nanocomposites based on ethylene/vinyl acetate copolymer (EVA), maleic anhydride-grafted EVA (EVAgMA), and nanosilica were prepared in a Haake Rheomixer. The structure of the EVA/EVAgMA/silica nanocomposites was characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The blending sequence was found to have a significant effect on the microstructure of EVA/EVAgMA/silica nanocomposites and the dispersion behavior of the nanosilica in the EVA matrix. The tensile properties (tensile strength and elongation at break), thermal behavior, crystalline structure and weatherability of the nanocomposites were also studied. The results showed that the above properties of the nanocomposites were enhanced remarkably using 1 wt% EVAgMA.

LINC01272 Suppressed Cell Multiplication and Induced Apoptosis Via Regulating MiR-7-5p/CRLS1 Axis in Lung Cancer

( Xuan Ma ),( Yang Liu ),( Hao Tian ),( Bo Zhang ),( Meiling Wang ),( Xia Gao ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.7

LINC01272 is a long non-coding RNA (lncRNA) that has been considered as a biomarker for many diseases including lung squamous cell carcinoma. Here, we investigated the function and mechanism of LINC01272 on lung cancer (LC). The differential expression of LINC01272 in LC and normal samples was analyzed by GEPIA based on the data from TCGA-LUAD database, as survival prognosis was analyzed through Kaplan-Meier Plotter. LINC01272 overexpression plasmid and miR-7-5p mimic were transfected into A549 and PC-9 cells. LINC01272, miR-7-5p and cardiolipin synthase 1 (CRLS1) mRNA expression was measured by quantitative reverse transcription-polymerase chain reaction. Cell viability was detected through MTT assay. Cell multiplication was evaluated by cell formation assay. Cell apoptosis was assessed through flow cytometry assay. Through bioinformatics, the target miRNA of LINC01272 and downstream genes of miR-7-5p were predicted. The targeting relationship was tested by dual luciferase reporter analysis. CRLS1, B-cell lymphoma-2 (Bcl-2), BCL2-associated X (Bax) and cleaved caspase-3 protein levels were detected through western blot. LINC01272 was downregulated in LC and low LINC01272 expression had poor prognosis. In A549 and PC-9 cells, LINC01272 inhibited cell viability and multiplication and induced apoptosis. LINC01272 negatively regulated miR-7-5p and CRLS1 was a target of miR-7-5p. MiR-7-5p reversed the effect of LINC01272 on viability, multiplication, apoptosis and expression of miR-7-5p and CRLS1 as well as apoptosis-related factors (Bcl-2, Bax and cleaved caspase-3). LINC01272 suppressed cell multiplication and induced apoptosis via regulating the miR-7-5p/CRLS1 axis in LC.

Preparation of Nd-Fe-B by nitrate-citrate auto-combustion followed by the reduction-diffusion process

Ma, Hao Xuan,Kim, Chang Woo,Kim, Dong Soo,Jeong, Ji Hun,Kim, In Ho,Kang, Young Soo The Royal Society of Chemistry 2015 Nanoscale Vol.7 No.17

<P>The Nd2Fe14B alloy has been successfully synthesized by nitrate-citrate auto-combustion followed by the reduction and diffusion process with low energy consumption. H3BO3, Fe(NO3)3·9H2O, and Nd(NO3)3·6H2O were used as precursors and citric acid was used as the chelating ligand of metal ions. Ammonia water was used to adjust pH to 7. CaH2 was used as a reducing agent for the reduction and diffusion process. NdFeO3 and Fe2O3 were produced during auto-combustion of gel. The combustion process of the gel was investigated by TGA/DTA curve measurements. The phase compositions were studied by XRD measurements. The differences of the overall morphology and magnetic properties were measured by SEM, TEM and vibrating sample magnetometry (VSM) at 300 K. The comparison of the magnetic properties of the reduced samples between the pellet type and the random powder type was done with VSM and it showed better magnetic properties of the pellet type Nd2Fe14B. Making a compact pellet type sample for reduction is more efficient for solid reduction and phase transition for higher coercivity.</P>

공동주택 실외 커뮤니티 공간의 사례조사

마현(Ma Xuan),황연숙(Hwang, Yeon-Sook) 한국실내디자인학회 2015 한국실내디자인학회 학술대회논문집 Vol.2015 No.10

The purpose of this study is to understand of living reduced working hours and increased leisure time. Therefore, people`s ideas on life style changed and different demands on residential environment are being made. Residents of apartment want a community facility that enables constant exchange with other residents and supports living. Ideas on how to use physical space to strengthen a community is becoming an issue these days. Community facility plays a crucial role in giving a certain characteristic to the whole apartment and improving the image as a community. It also provides a physical environment and induces active participation of community life from apartment residents, The community facility in an important environment for people. This study chose four apartments in Seoul. This study focuses on the characteristics of design community facility and would like to make a proposal about space planning for people`s community facility.

공동주택 실외 놀이 공간 계획의 친환경적 평가에 관한 연구

마현 ( Xuan Ma ),어성신 ( Sungsin Eo ),김지현 ( Jihyeon Kim ),황연숙 ( Yeonsook Hwang ) 한국공간디자인학회 2017 한국공간디자인학회논문집 Vol.12 No.4

(Background and Purpose) Outdoor play spaces are often the most frequently used public spaces in apartment housing, and places where various communities are formed and residents` health and comfort can be improved. This interest in outdoor play spaces, combined with growing emphasis on environment-friendly materials and energy conservation, has expanded the necessity of developing outdoor play spaces that are in harmony with and protective of the environment. The purpose of this study is to evaluate environment-friendly elements relevant to outdoor play spaces to improve the quality of outdoor play spaces within apartment complexes, and, based on the results, to provide baseline data related to environment-friendly planning measures for future apartment housing outdoor play spaces. (Method) This study targeted seven apartment housing outdoor play spaces located in Seoul and conducted a case analysis through on-site survey. Environment-friendly elements were extracted from preceding environment-friendly research and the environment-friendly certificate system, and, based on the elements, a checklist was made for environment-friendly evaluation of outdoor play spaces. Then, on-site surveys were performed at the seven target spaces using the checklist. (Results) This study, which evaluated seven play spaces and classified the environmental elements of land use, traffic, ecological environment, energy, and environmental load, found that apartment housing outdoor play spacing houses appeared to have inadequately considered the environment in their planning stages. First, although plans for play spaces utilizing the existing natural terrain were established in most cases, some had problems in the use of bike lanes and exclusive pedestrian roads near and directed toward the play space. Second, with respect to the artificial greening technique, side greening and facade greening were well applied, but the axis of the green belt was insufficiently considered. Third, although the systems for both rainwater load reduction for water resource conservation and trash and garbage disposal turned out to be relatively favorable, there was no plan for the use of rainwater, and the energy use and garbage disposal spaces were not sufficiently considered. (Conclusions) When play spaces are planned, a primary goal should be to promote children`s safety. This includes creating separate bike lanes and pedestrian roads towards play space. It also requires more attention paid to environment-friendly materials in the play space, including creating the green axis using the existing green belt as well as various types of ecology. Sustainability must also be an important consideration. Plans for outdoor play spaces should include water and energy conservation measures through rainwater use systems, water resource conservation systems, energy systems, and solar-powered lighting and recycling-type garbage disposals in harmony with adjacent landscapes to maintain cleanliness. In the future, follow-up studies should be conducted on the specific measures to utilize the study results as guidelines for the design of environment-friendly outdoor play spaces.

Small gas adsorption on Co–N4 porphyrin-like CNT for sensor exploitation: a first-principles study

Zhang Xuanning,Wang Yongjie,Wang Zhenhua,Ma Shouxiao 한국탄소학회 2020 Carbon Letters Vol.30 No.2

Using frst-principles theory, we investigated the adsorption performance of CoN4-CNT towards six small gases including NO, O2, H2, H2S, NH3, and CH4, for exploiting its potential application for chemical gas sensors. The frontier molecular orbital theory was conducted to help understand the conductivity change of the proposed material at the presence of gas molecules. The desorption behavior of gas molecules from CoN4-CNT surface at ambient temperature was analyzed as well to determine its suitability for sensing application. Results show that CoN4-CNT is a promising material for O2 and NH3 sensing due to their desirable adsorption and desorption behaviors while not appropriate for sensing NO due to the poor desorption ability and for sensing CH4 and H2 given the poor adsorption behavior. Our calculation would provide a frst insight into the CoN4-embedded efect on the structural and electronic properties of single-walled CNT, and shed light on the application of CoN4-CNT towards sensing of small gases.

Lead tolerance and accumulation characteristics of three Hydrangea cultivars representing potential lead-contaminated phytoremediation plants

Wenjie Ma,Bing Zhao,Xiaofan Lv,Xuan Feng 한국원예학회 2022 Horticulture, Environment, and Biotechnology Vol.63 No.1

Heavy metal contamination of soil is a serious environmental problem worldwide. With improving ecological awareness,phytoremediation has attracted increasing attention as an economic, effi cient, and environmentally friendly method to addressheavy metal pollution. Hydrangea plants are not only colorful and aesthetically pleasing, but they also grow vigorously. Inthis study, we examined the responses of three Hydrangea cultivars to diff erent levels of lead (Pb) stress in terms of theirgrowth responses, biochemical changes, and heavy metal accumulation. We found that (1) no visual heavy metal toxicitysymptoms were observed in the three Hydrangea cultivars under any Pb treatment. (2) At low concentrations of Pb (100–200 mg kg −1 ), the root length of the three cultivars increased signifi cantly compared with that of the control; no signifi cantchange was found in shoot biomass in the three cultivars under any Pb treatment. (3) The biochemical changes in responseto Pb stress diff ered between the cultivars. (4) Under all Pb treatments, the Pb concentrations in the roots were signifi cantlyhigher than those in the shoots of the cultivars, with translocation factor (TF) values < 1. Our results suggest that all threeHydrangea cultivars tested have the potential to tolerate high Pb levels in soil and showed Pb phytostabilization tendencieswith features essential for phytoextraction.

Seroprevalence and Risk Factors of Fascioliasis in Yaks, Bos grunniens, from Three Counties of Gansu Province, China

Xiao-Xuan Zhang,Sheng-Yong Feng,Jian-Gang Ma,Wen-Bin Zheng,Ming-Yang Yin,Si-Yuan Qin,Dong-Hui Zhou,Quan Zhao,Xing-Quan Zhu 대한기생충학열대의학회 2017 The Korean Journal of Parasitology Vol.55 No.1

Kinetic Investigations of RAFT Polymerization: Difunctional RAFT Agent Mediated Polymerization of Methyl Methacrylate and Styrene

Jianying Ma,Hui Xuan Zhang 한국고분자학회 2015 Macromolecular Research Vol.23 No.1

A difunctional reversible addition-fragmentation transfer (RAFT) agent, S,S′-bis (α,α′-dimethylacetic acid)trithiocarbonate (BDAT) is synthesized and used as chain transfer agent (CTA) to mediate homopolymerization ofmethyl methacrylate (MMA) and random copolymerization of methyl methacrylate-styrene (St) system, respectively. Kinetic factors of these two polymerizations, which influence polymerization process and characteristics ofpolymers, are investigated. Experimental results show that molecular weights of polymers increase linearly withmonomer conversions and these two polymerization kinetics behaviors exhibit “controlled/living” characteristics. Forthe homopolymerization of MMA, molecular weights increase gradually and are close to their theoretical values. Wherever, for the random copolymerization of MMA-St system, the presence of St has important influence on thekinetics of copolymerization. Addition of St to this system induces an induction period and this period increase withincreasing content of St in monomer composition.

Robustness Analyses of Internet Topology with Power-law Features

XU Ye,MA Wen-xuan 보안공학연구지원센터 2014 International Journal of Future Generation Communi Vol.7 No.1