Phenolic Constituents from Balanophora laxiflora with their Anti-inflammatory and Cytotoxic Effects

Nguyen Thi Hong Anh,Nguyen Thuy Duong,Pham Duc Vinh,Do Thi Ha 한국생약학회 2021 Natural Product Sciences Vol.27 No.1

Balanophora laxiflora Hemsl. (Balanophoraceae) is a traditional medicinal plant with a diverse array of biological activities. In our exploration of new bioactive constituents from B. laxiflora, we isolated five compounds, including a new lignan, balanophorone (5), and four known phenolic compounds (1–4). The chemical structures of these compounds were determined by extensive spectroscopic analyses, including 1D and 2D NMR, HR-ESI-MS, and CD. In addition, we evaluated the effects of each of the isolates (1–5) on the messenger RNA expression levels of tumor necrosis factor (TNF)-α and cyclooxygenase (COX)-2 in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and cytotoxicity against MCF-7 and MDA-MB-231 breast cancer cells. Compound 2 showed significant inhibition of LPS-induced COX-2 and TNF-α expression in RAW 264.7 macrophages, while compound 4 showed moderate cytotoxicity against MCF-7 and MDA-MB-231 breast cancer cells, with IC50 values of 18.3 and 30.7 μM, respectively. No significant effects on the viability of normal mammary epithelial cells were observed.

Optimizing the Carrier Density and Thermoelectric Properties of Sb2Te3 Films by Using the Growth Temperature

Duong Van Thiet,NGUYENVAN QUANG,Nguyen Thi Minh Hai,Nguyen Thi Huong,조성래,Duong Anh Tuan,Dang Duc Dung,트란반탐 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.8

In this work, we report on the structural and thermoelectric properties of Sb2Te3 films deposited on GaSb(111) substrates by using molecular beam epitaxy. The effects of the growth temperature on the microstructure and thermoelectric properties of the films were investigated. The results show that Sb2Te3 films grow on GaSb(111) along (00l) axis normal to the substrate and have a hexagonal structure with a layer-by-layer growth mode in growth temperature range from 200 to 250 °C while at 175 and 300 °C, the films show an island growth mode. Te and Sb2Te3 phases coexist at a growth temperature of 175 °C. The films exhibit a metallic behavior for growth temperatures below 250 °C and a semiconductor behavior at 300 °C. By changing growth temperature, we were able to vary the carrier density from 9.96×1018 to 4.55×1019 cm −3. At room temperature, the Seebeck coefficients are 110, 146, and 138 μV/K for growth temperatures of 175, 200 and 250 °C, respectively, and a large value of the power factor 61.67 μW/cm-K2 is achieved for the film grown at 250 °C.

Innovation Capacity of Student: A Case Study in Vietnam

Anh Duc DO,Nguyen Nguyen Thao PHAM,Thi Minh Phuong NGUYEN,Van Son TU,Cam Nhung NGUYEN,Hai Duong NGUYEN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.5

This study aimed to explore the factors affecting the innovation capacity of students at the National Economics University, Vietnam. Researchers used the innovation capacity model based on six factors, including personality traits, future orientation, creative skills, social interaction, content knowledge, and management skills. The empirical analysis used data from the survey of 303 students at National Economics University, Vietnam, with reliable tools (SPSS 26.0 software). The data were analyzed by testing the reliability of the scales, correlation analysis, and Pearson’ Linear Correlation Coefficient, exploratory factor analysis, as well as regression model based on the survey data. The research results identified the following factors affecting innovation capacity of students: management skills, social interaction, and personality traits have the strongest impact on innovation capacity of students; content knowledge has the following strongest effects on innovation capacity of students; and finally the creative skills that affects on innovation capacity of students. There is also a positive relationship between all the factors and innovation capacity of students. The result can serve as useful reference sources for scholars who are interested in the innovation field. It also helps university’s managers and policymakers build the appropriate environment to improve innovation capacity of students.

Thermoelectric Properties of Hot-Pressed Bi-Doped n-Type Polycrystalline SnSe

Nguyen, Van Quang,Nguyen, Thi Huong,Duong, Van Thiet,Lee, Ji Eun,Park, Su-Dong,Song, Jae Yong,Park, Hyun-Min,Duong, Anh Tuan,Cho, Sunglae Springer US 2018 NANOSCALE RESEARCH LETTERS Vol.13 No.1

<P><B>ᅟ</B></P><P>We report on the successful preparation of Bi-doped n-type polycrystalline SnSe by hot-press method. We observed anisotropic transport properties due to the (h00) preferred orientation of grains along the pressing direction. The electrical conductivity perpendicular to the pressing direction is higher than that parallel to the pressing direction, 12.85 and 6.46 S cm<SUP>−1</SUP> at 773 K for SnSe:Bi 8% sample, respectively, while thermal conductivity perpendicular to the pressing direction is higher than that parallel to the pressing direction, 0.81 and 0.60 W m<SUP>−1</SUP> K<SUP>−1</SUP> at 773 K for SnSe:Bi 8% sample, respectively. We observed a bipolar conducting mechanism in our samples leading to n- to p-type transition, whose transition temperature increases with Bi concentration. Our work addressed a possibility to dope polycrystalline SnSe by a hot-pressing process, which may be applied to module applications.</P><P><B>Highlights</B></P><P><P>We have successfully achieved Bi-doped n-type polycrystalline SnSe by the hot-press method.</P><P>We observed anisotropic transport properties due to the [h00] preferred orientation of grains along pressing direction.</P><P>We observed a bipolar conducting mechanism in our samples leading to n- to p-type transition.</P></P><P><B>Electronic supplementary material</B></P><P>The online version of this article (10.1186/s11671-018-2500-y) contains supplementary material, which is available to authorized users.</P>

Magnetotransport and Seebeck coefficient of epitaxial FeGe film grown on GaAs(100)

Anh Tuan Duong,Yooleemi Shin,Van Thiet Duong,Van Quang Nguyen,Sunglae Cho 한국자기학회 2016 한국자기학회 학술연구발표회 논문개요집 Vol.2016 No.11

Some geomorphic indices in the North Central Vietnam

Nguyen Anh Duong,Vu Van Chinh 한국지질과학협의회 2021 Geosciences Journal Vol.25 No.6

We have applied geomorphology to investigate the tectonic fault in the North Central Vietnam. At the local scale, the active tectonic possibility of fault zones in the study area is geomorphologically assessed for the first time. The results show the geomorphic indices of drainage basin asymmetry (AF = 0–34), valley floor width-to-height ratio (Vf = 0.21–1.71) applied to 50 drainage basins and mountain-front sinuosity (Smf = 1.07–1.58) calculated along 17 tectonic fault zones. The geomorphic analysis indicates that the modern activity of faults in the study area is moderate–weak. Only a few segments of the Truong Son and Dakrong-Hue faults are assessed as strongly active. The tectonic activity of this area is assessed with an average uplifting rate of about 0.2 mm/year according to the Smf and Vf analyses. In order to prove the existence of faults as well as their active possibility, the field survey has also been carried out by structural geological and geomorphological methods. The survey was conducted at 369 outcrops and approximately 12,000 fractures were measured. Based on the data on displacement and the processing of data on slip observed at the outcrops, we have identified the strike-slip tectonic stress state of Pliocene–Quaternary period with the sub-longitudinal compressional direction and the slip mechanism of fault zones in this period. It is a new finding of the contemporary crustal stress orientation of North Central Vietnam. The results of this study provided the geomorphic evidence to evaluate the potential seismic hazards of the North Central Vietnam.

Composites derived from synthetic clay and carbon sphere: Preparation, characterization, and application for dye decontamination

Nguyen Duy Dat,Ton That Loc,Mai Thuan Trieu,Dong Thanh Nguyen,Khuong Quoc Nguyen,My Linh Nguyen,Anh Duy Duong Le,Hai Nguyen Tran 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.4

Two new composites from synthetic clay-like materials and carbon spheres were developed. Layered doubledhydroxides (LDH) were synthesized from the coprecipitation of Mg2+ and Al3+ ions. Spherical hydrochar (SH) wasprepared from pure glucose through hydrothermal carbonization at 190 oC. The composite LDH–SH was synthesizedthrough a simple hydrothermal method of the mixture of LDH and SH. Another composite, LDO-SB, was directly preparedthrough the carbonization of LDH-SH at 500 oC. Under such high temperature, LDH was converted to layereddoubled oxides (LDO), and SH was transferred to spherical biochar (SB). Those materials were characterized by chemicalstability, surface morphology and element composition, crystal structure, surface functional group, and texturalcharacteristic. They were applied for removing cationic dye (methylene blue; MB) and anionic dye (Congo red; CR)under different pH solutions. Three adsorption components—kinetics, isotherm, and thermodynamics—were conductedunder batch experimenters. Results demonstrated that the LDH or LDO particles were assembled on the surfaceof SH or SB, respectively. The surface area, total pore volume, and average pore width of LDH–SH and LDO-SBwere 58.5 and 198m2/g, 0.319 and 0.440 cm3/g, and 21.8 and 8.89 nm, respectively. The maximum adsorption capacityof the materials, calculated from the Langmuir model, at 30 oC for CR and MB dyes was 1589 and 78.6mg/g (LDOSB)and 499 and 226mg/g (LDH-SH), respectively. The composites exhibited a higher affinity to anionic than cationicdyes, which resulted from the great contribution of the clay-like materials. Therefore, they can serve as a promisingcomposite for the decolorization of wastewater.

Domain structure and finite-size effects in Sr2-La FeMoO6 nanoparticles: A study by magnetic measurements

Duong Nguyen Phuc,Nguyet Dao Thi Thuy,Loan To Thanh,Man Nguyen Khac,Anh Luong Ngoc 한국물리학회 2023 Current Applied Physics Vol.49 No.-

In this work, a model for the microstructure of Sr2-xLaxFeMoO6 nanoparticles samples (0 ≤ x ≤ 0.4) was established based on scanning electron microscopy and magnetic studies. The analysis reveals antiphase crystalline domains in the particles with the size distribution centered around mean values below ~12 nm for all the samples. Such small-size domains are responsible for the superparamagnetic properties observed for temperatures below room temperature, which are dependent on their dipole interactions. According to the fraction of Fe atoms at the antiphase boundaries calculated under the spherical domain assumption, these domains have lower degrees of atomic disorder than those estimated from the saturation magnetization values at 5 K, which are consistent with the high spin polarization values previously reported. The Curie temperature values, and the broadening of the magnetic phase transition can be satisfactorily explained based on the domain size distribution.

3D-Brain MRI Segmentation Based on Improved Level Set by AI Rules and Medical Knowledge Combining 3 Classes-EM and Bayesian Method

Nguyen Ho Minh Duy,Tran Anh Tuan,Nguyen Hai Duong,Tran Anh Tuan,Nguyen Kim Dao,Atsuo Yoshitaka,Jin Young Kim,Seung Ho Choi,Pham The Bao 한국정보기술학회 2016 한국정보기술학회논문지 Vol.14 No.5

MRI and CT images are the most popular formats assisting a doctor in diagnosis and treatment, but highly accurate segmentation is a challenging problem due to intensity inhomogeneity and environmental noises. In this paper, we introduce an appropriate and effective automatic approach to facilitate this problem in two stages. In the first stage, skull region is removed from the brain by morphological active contour and level set process. Moreover, in level set process, some AI rules are defined on slice positions of brain to increase the accuracy. In the second stage, a modified EM method is performed on the resultant skull-stripping image to identify some candidate main regions of CSF (cerebro-spinal fluid), GM (gray matter), and WM (white matter). The candidate regions are then re-estimated into the proper CSF, GM, and WM through a Bayesian Estimation Process. The experimental results show that the proposed approach obtains a robust segmentation for IBSR, OASIS and Korean Hospital database. With the proposed AI-rules, the level set method gets good skull-stripping images regardless of MRI slice position in bran. Also, Bayesian postprocessing can improve the segmentation performance by 10~15% in CSF, GM and WM ratios compared the basic EM algorithm.

MBE growth and magnetic properties of epitaxial FeMn2O4 film on MgO(100)

Duong Van Thiet,Nguyen Thi Minh Hai,Nguyen Anh Phuong,Dang Duc Dung,Duong Anh Tuan,Nguyen Van Quang,Sunglae Cho 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.2