In Vitro Evaluation of Two Novel Antimalarial Derivatives of SKM13: SKM13-MeO and SKM13-F

Thuy-Tien Thi Trinh,김영아,홍혜리,Linh Thi Thuy Le,장하영,김순애,박현,김학성,여선주 대한기생충학ㆍ열대의학회 2022 The Korean Journal of Parasitology Vol.60 No.6

Antimalarial drugs play an important role in the control and treatment of malaria, a deadly disease caused by the protozoan parasite Plasmodium spp. The development of novel antimalarial agents effective against drug-resistant malarial parasites is urgently needed. The novel derivatives, SKM13-MeO and SKM13-F, were designed based on an SKM13 template by replacing the phenyl group with electron-donating (-OMe) or electron-withdrawing groups (-F), respectively, to reverse the electron density. A colorimetric assay was used to quantify cytotoxicity, and in vitro inhibition assays were performed on 3 different blood stages (ring, trophozoite, and schizonts) of P. falciparum 3D7 and the ring/mixed stage of D6 strain after synchronization. The in vitro cytotoxicity analysis showed that 2 new SKM13 derivatives reduced the cytotoxicity of the SKM13 template. SKM13 maintained the IC50 at the ring and trophozoite stages but not at the schizont stage. The IC50 values for both the trophozoite stage of P. falciparum 3D7 and ring/mixed stages of D6 demonstrated that 2 SKM13 derivatives had decreased antimalarial efficacy, particularly for the SKM13-F derivative. SKM13 may be comparably effective in ring and trophozoite, and electron-donating groups (-OMe) may be better maintain the antimalarial activity than electron-withdrawing groups (-F) in SKM13 modification.

Violation of Bans on Tobacco Advertising and Promotion at Points of Sale in Viet Nam: Trend from 2009 - 2015

Le, Thi Thanh Huong,Tran, Khanh Long,Phung, Xuan Son,Do, Phuc Huyen,Phan, Thuy Linh,Nguyen, Ngoc Bich,Nguyen, Xuan Lam,Le, Vu Anh,Tran, Thi Tuyet-Hanh Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.no.sup1

Comprehensive bans on tobacco advertising and promotion were introduced through tobacco control legislation in Viet Nam, but it has been established that violations of the bans are very common. This study was conducted to explore the trend in violations of bans on tobacco advertising and promotion at points of sale in Viet Nam in the past six years and to explore any differences in the violation situations before and after the Law on Tobacco Control came into effect on 1st May 2013. Quantitative data were collected through observation of violations of the bans on tobacco advertising and promotion at points of sale in 10 provinces throughout Viet Nam in four survey rounds (2009, 2010, 2011, and 2015). Variation in violation prevalence over time was examined by chi-square test using a Bonferini method. Binary logistic regression was employed to identify the factors that may have influences on different types of violation. A level of significance of p<0.05 was used for all tests in this article. The most common form of violation was the display of more than one pack/one carton of a cigarette brand. Violation of bans on tobacco advertising increased while violations on promotion ban and on displaying tobacco decreased through time. Some factors associated with the tobacco advertising and promotion bans included surveyed years, types of points of sale, regions and areas where the points of sale were located. The enforcement of the bans did not improve even after the issuance and the enactment of the Law on Tobacco Control. This suggests that the monitoring and enforcement of bans on tobacco advertising and promotion at points of sale should be strengthened. Penalties should be strictly applied for violators as indicated in the current tobacco control legislation.

Determinants Influencing Tax Compliance: The Case of Vietnam

NGUYEN, Thi Thuy Du'o'ng,PHAM, Thi My Linh,LE, Thanh Tam,TRUONG, Thi Hoai Linh,TRAN, Manh Dung Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.2

The purpose of this paper is to ascertain the key factors affecting tax compliance among Vietnamese firms in Vietnam. We employ both qualitative and quantitative research methods. Qualitative research has been carried out through focus group discussions with ten chief accountants and tax officers. Quantitative research has been conducted through interviews with 200 firms (chief accountants or financial directors) in Vietnam. Analysis of the model includes the following stages: (i) Cronbach's test for reliability of the scale, (ii) exploratory factor analysis (EFA), (iii) confirmatory factor analysis (CFA), and (iv) structural equation model (SEM). The results of the research show that voluntary tax compliance is directly affected by the three factors of audit probability, corporate reputation and business ownership. The probability of audit and severity of sanctions have the strongest impact on tax compliance. Therefore, the tax authorities need to strengthen the inspection of tax declarations, tax payments and tax refunds of firms. The paper confirms that enforced tax compliance is directly affected by the three factors of audit probability, sanction severity and social norms. Voluntary compliance and compulsory compliance have an effect on tax compliance, though voluntary compliance has a more powerful impact.

Critical Factors Affecting the Innovation Activities of Businesses: Evidence from Binh Dinh Province, Vietnam

NGUYEN, Thi Le Hang,PHAM, Ngoc Toan,DAO, Vu Phuong Linh,NGO, Thi Thanh Thuy,LE, Thi Thanh Binh Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.7

The study investigates the factors influencing the innovation activities in the enterprises in the Binh Dinh Province, Vietnam. By employing the dataset from a survey in 200 typical enterprises in Binh Dinh and using the Exploratory Factor Analysis and regression analysis, we found that there are eight factor groups affecting the innovation activities of enterprises. They include management of innovation promotion; market research capacity; leadership inspiring innovation; culture of innovation; human resources for implementing innovation; network connection; disseminating/sharing knowledge; and impact of producing/serving technology. All these factors strongly affect the innovation activities, which plays an important role in promoting the sustainable development of the Vietnamese enterprises, with the statistical significance level at 1%. Moreover, findings also show that, among these factors, the market research capacity is the strongest determinant of the innovation activity in the enterprise. An increase of 1 point of capacity of market research will increase the innovation activities in the enterprise by 0.114 point. It is followed by the management of promoting innovation, leadership inspiring innovation, and disseminating and sharing knowledge, with 0.104, 0.103 and 0.102 score, respectively. On the other hand, network connection is the weakest factor, with the score of 0.07 point.

Determinants of Operational Self-Sustainability of Microfinance Institutions in Vietnam

LE, Thanh Tam,DAO, Lan Phuong,DO, Ngoc Mai,TRUONG, Thi Hoai Linh,NGUYEN, Thi Thuy Duong,TRAN, Chung Thuy Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.10

The purpose of this paper is to investigate the determinants of the Operational Self-Sustainability (OSS) of Vietnamese microfinance institutions (MFIs). This research uses both qualitative and quantitative research methods: (i) qualitative research was via in-depth interviews with ten microfinance practitioners, policymakers and researchers; (ii) quantitative research was conducted by using panel data of 34 MFIs in the period 2011-2015 with binary logistics and OLS regressions. Results are as follows: (i) MFIs' OSS in Vietnam are mainly determined by five key factors: portfolio at risk (PAR>30), capital structure, gross loan portfolio, scope of activities and legal form; (ii) OSS are most affected by legal status (social organizations have better OSS than formal MFIs or programs/projects), location (MFIs focus in one province have higher OSS than working nationwide or just in one district), capital structure (MFIs with more equity proportion have higher OSS); (iii) surprisingly, average loan size per borrower and age of MFIs do not have statistically significant correlation with OSS. The key recommendations are: (i) MFIs should focus on its professionality and increase its equity; (ii) related stakeholders such as State Bank of Vietnam should promote the enabling ecosystem for microfinance development to enhance poverty reduction and economic development.

A Novel Injectable pH–Temperature Sensitive Hydrogel Containing Chitosan–Insulin Electrosprayed Nanosphere Composite for an Insulin Delivery System in Type I Diabetes Treatment

Thuy An Trinh,Thai Minh Duy Le,Hoang Gia Vinh Ho,Thi Cam Thach To,Vu Viet Linh Nguyen,Dai Phu Huynh,Doo Sung Lee 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

Faculty of Materials Technology, Ho Chi Minh University of Technology (HCMUT)/Vietnam National University Ho Chi Minh City; ¹School of Chemical Engineering and Theragnostic Macromolecules Research Center, Sungkyunkwan University; ²Vietnam National University Ho Chi Minh City/National Key Laboratory of Polymer and Composite Materials, Ho Chi Minh University of Technology, Vietnam National University; ³Faculty of Materials Technology, Ho Chi Minh University of Technology (HCMUT)/ Vietnam National University Ho Chi Minh City/Research Center for Polymeric Materials, Ho Chi Minh University of Technology, Vietnam National University In this research, a novel insulin composite delivery system was prepared and characterized. Insulin drug was loading in chitoshan nanospheres using electrospraying method, a pH- and temperature-sensitive biodegradable hydrogel, which is an oligomer serine-poly(lactide)-poly(ethylene glycol)-poly (lactide)-oligomer serine (OS-PLA-PEG-PLA-OS) pentablock copolymer was used as a matrix to containing chitosan–insulin electro sprayed nanospheres (CIN). The properties of the OS-PLA-PEG-PLA-OS pentablock copolymer and the chitosan–insulin nanoparticles such as sol-gel transition, degradation in vitro and in vivo were characterized. The results showed that the chitosan–insulin nanospheres uniformly distributed in the matrix had a reinforcing effect on the mechanical properties and prolonged the degradation time of the hydrogel depot under body conditions. In addition, the cytotoxicity experiment results indicate that the composite could be used as a biomaterial for drug delivery system. The composite solutions accommodating different concentrations of the chitosan–insulin nanospheres were subcutaneously injected into induced diabetic BALB/c mice to study the in vivo insulin-release profile. The result showed that insulin concentrations in blood plasma were maintained at a steady-state level. Furthermore, the bio-properties of the insulin were retained and it showed a blood glucose level reducing effect for more than 60 hours after injection to a streptozotocin (STZ)-induced diabetic mouse model. The results suggested that this injectable pH–temperature sensitive hydrogel containing chitosan– insulin electro sprayed nanosphere composites has promising potential applications for type 1 diabetes treatment.

Effect of the Cultivation Technology on the Yield of Paddy Straw Mushroom (Volvariella volvacea)

Thi-Thuy-Hai Luu,Dang-Khoa Bui,Nga Huynh,Truc-Linh Le,Iain David Green 한국균학회 2022 韓國菌學會誌 Vol.50 No.3

The edible paddy straw mushroom Volvariella volvacea (Bull. ex F.) Singer has high nutritional and medicinal values. They are grown on a wide variety of agricultural byproducts using different several methods. The result of this present study showed that type of bed and cultivation condition (outdoor/indoor) had effects on the yield of paddy straw mushrooms grown on the spent oyster mushroom sawdust. The treatment of circular compact bed under indoor cultivation condition (CYIC) had the best yield and biological efficiency (B.E.) with 2,119.2 g/bed and 14.5%, respectively, followed by the treatment of conventional bed under outdoor cultivation condition (COOC) with the yield and B.E. of 1,935.5 g/bed and 13.2%, respectively, but the lowest yield and B.E. were observed in the treatment of conventional bed under indoor cultivation condition (COIC) with 1,226.1 g/bed and 8.4%, respectively. Paddy straw mushrooms cultivated on spent oyster mushroom sawdust should be proper in both outdoor and indoor conditions by conventional and circular compact methods as well. However, in indoor conditions, paddy straw mushrooms should be grown in a circular compact bed to ensure the temperature of the bed is suitable for the mushroom growth.

Green synthesis of silver nanoparticle-decorated porous reduced graphene oxide for antibacterial non-enzymatic glucose sensors

Hoa, Le Thuy,Linh, Ngo Thi Yen,Chung, Jin Suk,Hur, Seung Hyun Springer-Verlag 2017 IONICS -KIEL- Vol.23 No.6

Multi-dimensional Ag/NiO/reduced graphene oxide nanostructures for a highly sensitive non-enzymatic glucose sensor

Ngo, Yen-Linh Thi,Hoa, Le Thuy,Chung, Jin Suk,Hur, Seung Huyn ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.712 No.-

<P><B>Abstract</B></P> <P>A highly sensitive non-enzymatic glucose sensor was fabricated by hybridizing 0- dimensional (0D) Ag nanoparticles, 3D flower-like nickel oxide (NiO) nanostructures, and 2D reduced graphene oxide (rGO) as the sensing interface by hydrothermal synthesis. The resulting hybrid structures were characterized by Raman spectroscopy, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and high-resolution transmission electron microscopy. The Ag/NiO/rGO fabricated in this study showed high electrochemical activity towards the oxidation of glucose in a 0.1 M NaOH solution. At an applied potential of +0.6 V, it exhibited a rapid response time (<4 s), a broad linear range of glucose concentrations up 25 mM with an extraordinarily high sensitivity of 1869.4 μA mM<SUP>−1</SUP> cm<SUP>−2</SUP>. The detection limit was as low as 2.44 μM. In addition, the response towards common interfering species, such as sucrose, lactose, fructose, ascorbic acid, dopamine, and uric acid were low enough to be avoidable.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Non-enzymatic glucose sensors were fabricated by hybridizing multi-dimensional Ag/NiO/rGO. </LI> <LI> Excellent electrocatalytic activity of the Ag/NiO/rGO toward glucose oxidation was achieved. </LI> <LI> The well-dispersed Ag/NiOs on the rGO surface enhanced the charge transfer. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Using sulfate-functionalized Hf-based metal–organic frameworks as a heterogeneous catalyst for solvent-free synthesis of pyrimido[1,2-a] benzimidazoles via one-pot three-component reaction

Minh-Huy Dinh Dang,Linh Ho Thuy Nguyen,Trang Thi Thu Nguyen,Ngoc Xuan Dat Mai,Phuong Hoang Tran,Tan Le Hoang Doan 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.103 No.-

Functionalized metal–organic frameworks have recently received significant attention in heterogeneouscatalysis applications due to their high catalytic activity. In this work, a sulfate-functionalized Hf-clusterbasedmetal–organic framework was prepared via sulfation of a Hf-MOF, named Hf-BTC, constructed byHf6 clusters and 1,3,5-tricarboxylate linkers. The Hf-BTC-SO4 material was consequently demonstrated tobe an efficiently reusable superacid catalyst for a one-pot three-component reaction of pyrimido[1,2-a]benzimidazoles synthesis. The reaction catalyzed by the sulfated Hf-BTC could be carried out under mildand solvent-free conditions and give superior performance in a wide range of substrates. According todetailed investigation, the good catalytic performance of the sulfated-functionalized MOF likely originatesfrom the high-porosity framework and the high active sites of the functionalized clusters. Importantly, the catalyst could be easy to recover and reuse the functionalized framework several timeswith minor changes in catalytic efficiency.