Numerical Analysis of Dielectrophoresis-Based Microfluidic Chip with a Facing-Electrode Design for Cell Separation

Nguyen Thu Hang,Nguyen Mai Chi,Nguyen Hoang Trung,Thi Y Van Tran,Vu Ngoc Trung,Thu Hang Bui,Duc Trinh Chu,Bui Tung Thanh,Jen Chun-Ping,Quang Loc Do 한국농업기계학회 2024 바이오시스템공학 Vol.49 No.1

Purpose Circulating tumor cell separation and analysis have played a critical role in cancer diagnosis, prognosis, and treatment. In this work, we aim to design and investigate a novel biochip that integrates dielectrophoresis, microfl uidic technology to separate circulating tumor cells from blood cells. To create a dielectrophoresis-induced non-uniform electric fi eld, a facing-electrode design was proposed and utilized, in which a slanted electrode array and a simple rectangular ground electrode are placed parallel on the top and bottom parts of the microfl uidic channel, respectively. This design can reduce the particle position dependence in the microchannel and the complexity of the microfabrication process. Methods The separation process, effi ciency, and optimization of the proposed device were numerically investigated using the fi nite element method. Parametric research was conducted to comprehensively examine the impact of various operating and design factors on the cell movement and trajectories in the microfl uidic device. Results The results indicated the potential of the proposed biochip to ensure cancer cell separation from blood cells with high effi ciency, high purity in a label-free, non-invasive, easy integration, and low-cost manner. Under the optimal conditions, the separation effi ciency reached 92%, 88%, and 96% for human colon cancer cells (HT-29), red blood cells, and white blood cells, respectively. Conclusions In this study, a novel DEP-based microfl uidic chip was proposed to separate HT-29 tumor cells from blood cells and numerically investigated to verify the performance of the biochip design. Our fi ndings could provide a foundation for further theoretical and practical investigations. The proposed system can separate cancer cells from red blood cells and white blood cells as well as off ers numerous advantages, such as compact size, low voltage, high effi ciency, non-invasiveness, and label-free nature. The tumor cell enrichment platform has the potential for application in cancer detection, analysis, and assessment.

Effect of Co-Doping and Tri-Doping with Transition Metals and a Nonmetal on Photocatalytic Activity in Visible Light of TiO2 Thin Film

Hang Nguyen Thai Phung,Van Nguyen Khanh Tran,Phuong Ai Duong,Hung Vu Tuan Le,Nguyen Duc Truong 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.70 No.11

Mono, co- and tri-doped TiO2 thin films with the transition metals (vanadium and/or chrominium) and a nonmetal (nitrogen) have been fabricated by sol-gel method. X-ray diffraction results clearly reveal anatase crystal structure for all obtained samples and doping with any dopants doesn’t change the anatase phase of TiO2. Compared to TiO2, three types of doped TiO2 thin films exhibit a red-shift in the absorption edge and have much better photocatalytic properties for methylene blue degradation in visible light region. The maximum visible-photocatalytic performance was achieved for tri-doped TiO2 sample. The mechanism for enhancing visible-photocatalytic activity of co-doped and tri-doped TiO2 thin films was also examined.

Antioxidant Compounds Isolated from the Roots of Phlomis umbrosa Turcz.

Duc Hung Nguyen,Duc Dat Le,Bing Tian Zhao,마은숙,민병선,우미희 한국생약학회 2018 Natural Product Sciences Vol.24 No.2

Two triterpenoids, arjunolic acid (1), belleric acid (2), five phenylethanoids, martynoside (3), orobanchoside (4), 3,4-dihydroxyphenethylalcohol-6-O-caffeoyl-b-D-glucoside (5), leucosceptoside B (6), lunarii- folioside (7), four phenolic acids, ferulic acid (8), syringic acid (9), vanillic acid (10), 4-hydroxybenzoic acid (11), and one lignan, (+)-syringaresinol-b-D-glucoside (12), were isolated from the roots of P. umbrosa. All isolated compounds were explored for their antioxidant potential in the DPPH and ABTS assays. In DPPH assay, compound 5 showed high antioxidant capacity. Compounds 3, 4, 6, and 7 displayed considerable antioxidant activities. In addition, compounds 5-7 exhibited potential antioxidant capacities in the ABTS assay.

Development and Validation of HPLC-PDA Method and Pattern Recognition Analyses Using Eight Marker Compounds for the Quality Control Between the Seeds of Cuscuta chinensis Lam. and Cuscuta japonica Choisy

Duc Hung Nguyen,Bing Tian Zhao,Duc Dat Le,마은숙,민병선,우미희 한국생약학회 2019 Natural Product Sciences Vol.25 No.4

Cuscuta chinensis Lam. and Cuscuta japonica Choisy are parasitic plants. C. chinensis seeds were traditionally used for treatment of kidney and liver deficiencies. C. japonica seeds were used as tonic medicine to improve liver function and strengthen kidneys, treatment of high blood pressure, chronic diarrhea, and sore eyes. Cuscutae Semen are seeds of only C. chinensis in Korean Herbal Pharmacopoeia (K.H.P.). The developed HPLC-PDA method easily, accurately, and sensitively quantified using eight marker compounds [hyperoside (1), astragalin, (2), quercetin (3), kaempferol (4), chlorogenic acid (5), 3,4-di-O-caffeoylquinic acid (6), 1,5-di-O-caffeoylquinic acid (7), and 4,5-di-O-caffeoylquinic acid (8)]. In addition, the method may be used to distinguish seeds between C. chinensis Lam. and C. japonica Choisy. Furthermore, the result from the current study was applied to clarify samples between steam processed and unprocessed samples of C. chinensis by pattern analysis.

Fiscal Decentralization, Corruption, and Income Inequality: Evidence from Vietnam

Hung Thanh NGUYEN,Thuy Hoang Ngoc VO,Duc Doan Minh LE,Vu Thanh NGUYEN 한국유통과학회 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.11

The objective of this research paper is to study the simultaneous relationship between fiscal decentralization, corruption, and income inequality among Vietnamese provinces. We use a balanced panel data set of 63 provinces/cities in Vietnam in the period from 2011 to 2018. The study used 3SLS-GMM (Three Stage Least Squares - Generalized Method of Moments estimator) and GMM-HAC (Generalized Method of Moments - Heteroskedastic and Autocorrelation Consistent estimator). Empirical evidence shows a strong simultaneous relationship: increased corruption will increase regional income disparities, income inequality, and increase fiscal decentralization. In addition, the results also suggest that an increase in per-capita income will reduce the level of corruption, or better control corruption of each province. The degree of increase in income inequality, which reduces fiscal decentralization, is the same for trade liberalization. All demonstrate that there is a simultaneous relationship between fiscal decentralization, corruption, and income inequality. In a region of high public governance quality, fiscal decentralization positively effects its economic growth. This issue will indirectly increase income inequality between provinces within a country. Our findings imply that a country’s fiscal decentralization strategy should be linked to improving corruption control and local governance effectiveness, indirectly improving income inequality between localities or regions.

Baseline susceptibility of Asian corn borer (Ostrinia furnacalis (Guenée)) populations in Vietnam to Cry1Ab insecticidal protein

Duc Khanh Le,Quang Khai Le,Thi Thuy Hang Tran,Duc Viet Nguyen,Thi Hang Dao,Thi Thuy Nguyen,Xuan Lam Truong,Quang Cuong Nguyen,Huy Phong Pham,Thi Thu Thuy Phan,Gajendra Babu Baktavachalam 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2

Susceptibility of Asian corn borer (ACB), Ostrinia furnacalis (Guenée) to Bacillus thuringiensis (Bt) Cry1Ab protein was studied between 2015 and 2016 with 11 ACB populations, collected from various geographical regions in Vietnam. A concentration range of Cry1Ab from 0.20 to 26.10 ng/cm 2 of diet was evaluated against F 1 ACB neonates using diet surface-overlay bioassays. Mortality data was recorded daily until seven days after infestation. Growth inhibition was recorded at the end of seven days. The median lethal concentration (LC 50 ) varied ≈3-fold among the different populations, ranging from 0.58 to 1.83 ng/cm 2 of diet with an overall mean of 0.86 ng/cm 2 of diet. Even the lowest concentration of 0.20 ng/cm 2 caused 73.53% growth inhibition. > 90% growth inhibition was achieved at 0.82 ng/cm 2 or higher concentrations. The results reflect natural variation in Bt susceptibility among ACB populations rather than variation caused by prior exposure to selection pressures. LC 99 value (17.26 ng/cm 2 ) was generated by pooling mortality data across different populations. The upper fiducial limit of LC 99 (24.38 ng/cm 2 ) could be a potential diagnostic dose for future resistance monitoring programs. The findings from this study suggest that ACB populations in Vietnam are highly susceptible to Cry1Ab protein. This is the first report of Cry1Ab susceptibility of different ACB populations in Vietnam and will serve as a baseline for future resistance monitoring work.

Phenolic Constituents and Their Anti-inflammatory Activity from Echinochloa utilis Grains

Duc Hung Nguyen,Bing Tian Zhao,Duc Dat Le,Ki Yun Kim,김영호,윤영호,고지연,우관식,우미희 한국생약학회 2016 Natural Product Sciences Vol.22 No.2

Seven phenolic compounds including p-coumaric acid (1), 4-hydroxybenzoic acid (2), 4-hydroxy-benzaldehyde (3), vanillic acid (4), luteolin (5), acacetin (6), and tricin (7), were isolated from the methylene chloride and ethyl acetate fractions of Echinochloa utilis grains. Compounds (1 - 4, 6) were isolated for the first time from this plant. These compounds were tested for inhibitory activities against LPS-induced NO production in RAW 264.7 cells. Compounds 5 and 6 displayed significant inhibitory effects, with IC50 values of 27.9 ? 2.6 and 14.0 ? 1.1 ?M, respectively. The results suggested that E. utilis ethanolic extract may be used as a potential source of anti-inflammatory agents and functional foods for the treatment of allergic diseases.

A Study on the Poverty of Mountain People Depending on Forests

NGUYEN, Phuong Thi Minh,NGUYEN, Song Van,DO, Duc Tai,NGUYEN, Quynh Thi Thuy,DINH, Thanh Trung,NGUYEN, Hang Phan Thu Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.7

Livelihood capitals have a clear influence on livelihood development. As for the livelihood results, it has been pointed out in the analysis of the poor households that the ability of people to escape poverty depends especially on the access to livelihood capitals. This study aims to analyze the impacts of livelihood capital on poverty among mountain people who depend on forests through human capital, social capital, natural capital, physical capital and financial capital. This research employs the model of binary regression function. Independent variables x1, x2, …, xn are targets of livelihood strategy, vulnerability context, and livelihood capitals. These variables were selected to be included in the original model with dependent variable Y as poor and non-poor households. This study surveys households living in upland areas, near forests, and households of ethnic minorities. The results show that,out of the poor household rate, nearly 4% are newly-poor households or those falling back into poverty. Therefore, the government needs to pay more attention to this disadvantaged group and implements policies such as education and training policies, credit support policies, policies to support forest development, and payment for forest environmental services in the context of emerging countries like Vietnam.

A Comparative Study on the Adipogenic and Myogenic Capacity of Muscle Satellite Cells, and Meat Quality Characteristics between Hanwoo and Vietnamese Yellow Steers

Nguyen Thu Uyen,Dao Van Cuong,Pham Dieu Thuy,Luu Hong Son,Nguyen Thi Ngan,Nguyen Hung Quang,Nguyen Duc Tuan,In-ho Hwang 한국축산식품학회 2023 한국축산식품학회지 Vol.43 No.4

Myogenesis and adipogenesis are the important processes determining the muscle growth and fat accumulation livestock, which ultimately affecting their meat quality. Hanwoo is a popular breed and its meat has been exported to other countries. The objective of this study was to compare the myogenesis and adipogenesis properties in satellite cells, and meat quality between Hanwoo and Vietnamese yellow cattle (VYC). Same 28-months old Hanwoo (body weight: 728±45 kg) and VYC (body weight: 285±36 kg) steers (n=10 per breed) were used. Immediately after slaughter, tissue samples were collected from longissimus lumborum (LL) muscles for satellite cells isolation and assays. After 24 h post-mortem, LL muscles from left carcass sides were collected for meat quality analysis. Under the same in vitro culture condition, the proliferation rate was higher in Hanwoo compared to VYC (p<0.05). Fusion index was almost 3 times greater in Hanwoo (42.17%), compared with VYC (14.93%; p<0.05). The expressions of myogenesis (myogenic factor 5, myogenic differentiation 1, myogenin, and myogenic factor 6)- and adipogenesis (peroxisome proliferator-activated receptor gamma)-regulating genes, and triglyceride content were higher in Hanwoo, compared with VYC (p<0.05). Hanwoo beef had a higher intramuscular fat and total monounsaturated fatty acids contents than VYC beef (p<0.05). Whilst, VYC meat had a higher CIE a* and total polyunsaturated fatty acids content (p<0.05). Overall, there was a significant difference in the in vitro culture characteristics and genes expression of satellite cells, and meat quality between the Hanwoo and VYC.

Influence of MoS2 deposition time on the photocatalytic activity of MoS2/ V, N co-doped TiO2 heterostructure thin film in the visible light region

Hang Nguyen Thai Phung,Nguyen Duc Truong,Phuong Ai Duong,Le Vu Tuan Hung 한국물리학회 2018 Current Applied Physics Vol.18 No.6

Electron-hole separation and a narrow band-gap are essential steps to obtain efficient photocatalysis, towards which the use of co-catalysts or co-doped-TiO2 photocatalysts has become a widely used strategy. In this article, the combination of MoS2 and co-doping of V, N is the goal to achieve high performance photocatalysts. We synthesized MoS2/V, N co-doped TiO2 heterostructure thin film by solgel and chemical bath deposition methods. Herein, we investigated the influence of deposition time of MoS2 layer on visible-photocatalytic activity of the obtained samples. The thin films were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UVevis spectroscopy techniques. Visible-photocatalytic activity of these samples were evaluated on the removal of methylene blue (MB) under visible light irradiation. The results show that the aforementioned heterostructure thin films have better photocatalytic activities than those of TiO2, MoS2 and V, N codoped TiO2 counterparts in visible light region. The mechanism for increasing visible-photocatalytic property of the heterostructure thin films is discussed in detail. We find that MoS2/V, N co-doped TiO2 heterostructure thin film at MoS2 deposition time of 45-min shows the highest photocatalytic performance in the visible light region with MB photodegradation rate about 99% for 150 min and the degradation rate constant is 2.06 times higher than that of V and N co-doped TiO2 counterpart.