Two new species of Camellia (Theaceae) from Vietnam

Lieu Thi Nguyen,Ninh Tran,Uematsu CHIYOMI,Katayama HIRONORI,Dung Van Luong,Son Thanh Hoang,Ky Danh NGUYEN,Hung Viet NGUYEN,Toan Canh THAI 한국식물분류학회 2018 식물 분류학회지 Vol.48 No.2

Two new species of Camellia (Theaceae) are described from Vietnam: Camellia vuquangensis Luong, Tran & L. T. Nguyen and Camellia hatinhensis Luong, Tran & L. T. Nguyen. The new taxa were col- lected from Vu Quang National Park in the center of Vietnam. The new finds are morphologically dissimilar to all known Camellia species. Recent Camellia discoveries have increased the number of species recorded in Viet- nam from 50 to 75, making Vietnam a center of diversity and a crucial area for more research into the diversity and distributions of Camellia.

Building Firm’s Competitive Advantages through Supplier Development

Nguyen,Phi Hoang 한국유통과학회 2019 KODISA ICBE (International Conference on Business Vol.2019 No.-

Nowadays competition is becoming tougher in all areas of business. To survive in a such difficult period, all firms must think how to create and secure the competitive advantage for their own. One of the ways to build competitive advantage for firm is to develop suppliers which we can call supplier development. This research will analyze the importance of supplier development for buying firm, propose a research framework with three hypotheses need to be tested. One tested, the practitioners and researchers can know that which supplier development activities can be selected to do to create the competitive advantage for firm.

The Effect of the Ratio of C45 Carbon to Graphene on the Si/C Composite Materials Used as Anode for Lithium-ion Batteries

Hoang Anh Nguyen,Thi Nam Pham,Le Thanh Nguyen Huynh,Tran Ha Trang Nguyen,Viet Hai Le,Nguyen Thai Hoang,Thi Thom Nguyen,Thi Thu Trang Nguyen,Dai Lam Tran,Thi Mai Thanh Dinh The Korean Electrochemical Society 2024 Journal of electrochemical science and technology Vol.15 No.2

Due to its high theoretical capacity, Silicon (Si) has shown great potential as an anode material for lithium-ion batteries (LIBs). However, the large volume change of Si during cycling leads to poor cycling stability and low Coulombic efficiency. In this study, we synthesized Si/Carbon C45:Graphene composites using a ball-milling method with a fixed Si content (20%) and investigated the influence of the C45/Gr ratio on the electrochemical performance of the composites. The results showed that carbon C45 networks can provide good conductivity, but tend to break at Si locations, resulting in poor conductivity. However, the addition of graphene helps to reconnect the broken C45 networks, improving the conductivity of the composite. Moreover, the C45 can also act as a protective coating around Si particles, reducing the volume expansion of Si during charging/discharging cycles. The Si/C45:Gr (70:10 wt%) composite exhibits improved electrochemical performance with high capacity (~1660 mAh g^-1 at 0.1 C) and cycling stability (~1370 mAh g^-1 after 100 cycles). This work highlights the effective role of carbon C45 and graphene in Si/C composites for enhancing the performance of Si-based anode materials for LIBs.

Correlation and Path Analysis of Association among Yield, Micronutrients, and Protein Content in Rice Accessions Grown Under Aerobic Condition from Karnataka, India

Nguyen Phuong Thuy(Nguyen Phuong Thuy ),Nguyen Ngoc Trai(Nguyen Ngoc Trai ),Bui Dang Khoa(Bui Dang Khoa ),Nguyen Hoang Xuan Thao(Nguyen Hoang Xuan Thao ),Vuong Tuan Phong(Vuong Tuan Phong ),Quach Van 한국육종학회 2023 Plant Breeding and Biotechnology Vol.11 No.2

Genetic variability and correlation analysis are fundamental references for the innovative development of breeding programs to improve varieties and desirable traits. In the present study, the correlation and path analysis was conducted to understand the association among yield, micronutrients (iron and zinc), and protein content under aerobic conditions in local rice landraces from various agro ecological regions of Karnataka, India. The grain yield per plant showed a significant positive correlation with plant height, the tiller number, spikelet fertility, flag leaf length, and test weight. The zinc content was negatively correlated with grain yield per plant. The phenotypic path-coefficient analysis revealed that the total number of tillers, grain length, test weight, and harvest index exhibited a positive direct effect on grain yield per plant, while Grain protein content showed a low direct effect on this trait. This study also indicated that harvest index, flag leaf length, spikelet fertility, and test weight could be considered to make for a higher yield.

Effect of salicylic acid and yeast extract on curcuminoids biosynthesis gene expression and curcumin accumulation in cells of Curcuma zedoaria

Nguyen Hoang Loc,Truong Thi Phuong Lan,Nguyen Duc Huy,Nguyen Ngoc Luong,Hoang Tan Quang,Trinh Huu Tan,Le Thi Anh Thu,Nguyen Xuan Huy 한국식물생명공학회 2019 JOURNAL OF PLANT BIOTECHNOLOGY Vol.46 No.3

The aim of this study is to evaluate the effect of yeast extract (YE) and salicylic acid (SA) on the expression of curcuminoid-biosynthesis genes (CzDCS and CURS1-3), and accumulation of curcumin in Curcuma zedoaria cell cultures. The results showed that, in cells treated with YE or SA, the expression levels of curcuminoid genes were 1.14- to 3.64-fold higher than the control (untreated cells), in which the YE exhibited a stronger effect in comparison with SA. Curcumin accumulation also tended to be similar to gene expression, curcumin contents in YE- or SA-treated cells were 1.61- to 2.53-fold higher than the control. The SA treatment at the fifth day of culture stimulated the curcumin accumulation and expression in all four genes compared to that at the beginning. While the YE treatments gave different results, the CzCURS1 and CzCURS3 genes were expressed strongly in cells that were treated at the beginning. However, the CzDCS and CzCURS2 genes showed the opposite expression pattern, they were activated strongly in the treatments at day five of the culture. However, the content of curcumin reached its maximum value on the fifth day of culture in all investigations.

Advanced Magnetic Materials Produced by Using Rapid Quenching Technology

Nguyen Hoang Nghi,Nguyen Van Dung,Trinh Thi Thanh Nga,Bui Thi Khanh Nhung,Mai Thanh Tung,Nguyen Huu Tinh,Hoang Nhat Hieu,Bui Xuan Chien,Nguyen Thi Hong Tam 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.6

Amorphous alloys produced by using a rapid quenching technique are considered to be a precursor for producing nanosized and multiphase structures by precipitation (the top-down method). By using this technique, several new magnetic materials with different magnetic properties based on different physical mechanisms have been manufactured and investigated. Three new magnetic materials, a nanocrystalline soft magnetic material, a soft-hard permanent magnet and a Me-3d granular alloy with a GMR effect, what were prepared under local conditions, are presented and discussed in the experimental point of view. Amorphous alloys produced by using a rapid quenching technique are considered to be a precursor for producing nanosized and multiphase structures by precipitation (the top-down method). By using this technique, several new magnetic materials with different magnetic properties based on different physical mechanisms have been manufactured and investigated. Three new magnetic materials, a nanocrystalline soft magnetic material, a soft-hard permanent magnet and a Me-3d granular alloy with a GMR effect, what were prepared under local conditions, are presented and discussed in the experimental point of view.

Four novel mutations in the androgen receptor gene from Vietnamese patients with androgen insensitivity syndrome

Nguyen Thu Hien,Nguyen Duc Quan,Kim Lien Nguyen Thi,Thi Thanh Ngan Nguyen,Nguyen Thi Phuong Mai,Tran Ngoc Dung,Nguyen Huy Hoang 한국유전학회 2023 Genes & Genomics Vol.45 No.4

Background Androgens and androgen receptor (AR) are critical regulators of the masculinization process in male sexual development. The absence of a functioning AR results in the development of the androgen insensitivity syndrome (AIS), a rare disorder of sexual development (DSD) characterized by the external genitalia feminization, gynecomastia, and impaired spermatogenesis. Objective To determine the AR gene mutations associated with male DSD in four unrelated Vietnamese patients. Methods To detect the disease-causing mutations, whole exome sequencing (WES) was performed on four patients diagnosed with AIS. Sanger sequencing was then used for validation of the identified mutations. Finally, 12 web-based tools, three-dimensional protein modeling software, and the guidelines issued by the American College of Medical Genetics and Genomics were used to assess the potential pathogenicity of these mutations. Results Four distinct novel mutations, namely c.1834T > A (p.Cys612Ser), c.2122 C > G (p.Leu708Val), c.2630T > G (p.Phe877Cys), and c.2641 C > A (p.Leu881Met) in the AR gene, were identified in four AIS patients using WES. The in silico analysis results revealed that the Cys612, Leu708, Phe877, and Leu881 sites are important for an appropriate response to androgens of the AR, and mutation at these sites can have adverse effects on the AR functions, androgen–AR interaction, and AR signaling pathway. Conclusions WES and in silico analyses strongly suggested that four novel AR mutations are pathogenic and have led to the development of AIS in the four Vietnamese patients under consideration.

New Trade Protectionism Response to COVID-19: An Investigation on Firm Export Performance in an Emerging Country

Hoang Nguyen(Hoang Nguyen ),Tu Phan Thanh(Tu Phan Thanh ),Hee-Cheol Moon(Hee-Cheol Moon),Binh Do(Binh Do ) The International Academy of Global Business and T 2023 The International Academy of Global Business and T Vol.19 No.3

Purpose - Given the significance of concerns raised about the global shift toward protectionism under trade policy uncertainty context, and echoed by requests to contribute to issues that concern a wider variety of stakeholders, this study aims to review new trade protection measures in response to the pandemic crisis and their effects on export performance from an emerging country’s exporters. Design/Methodology/Approach - Research data were gathered by surveying 613 export managers of different types of exporters in Vietnam from a list of exporters provided by Ministry of Industry and Trade, and then applied a regression model for analysis. Findings - The study demonstrated a negative relationship between firm export performance and six trade protectionism measures, including industrial subsidies, public-procurement restrictions, FDI restrictions, standards protectionism, green protectionism, and regional integration. Only restrictions on migrant workers had no appreciable impact on firm export performance. Additionally, only employee number, out of the three control factors, significantly and positively affected how well firms succeed in exporting. Research Implications - The study’s findings have significant ramifications and contributions to theory and practice in international trade for an emerging country to overcome new trade protectionism measures. To support firms in expanding export markets, the government of an emerging country should concentrate on establishing and developing policies to support exporters, especially small and medium enterprises. Firms should pursue a sustainable export strategy in light of the emergence of new trade protectionism in significant import markets.

Enhancing Removal of Acid Orange II by Heterogeneous Catalytic Ozonation Using ZnO Nanoparticles-Modified Fly Ash Composite

Hoang Van Hung,Chu Thi Hong Huyen,Nguyen Thi Dong,Nguyen Thi Hong Vien,Nguyen Thu Huyen,Luu Thi Cuc,Van Huu Tap,Nguyen Hoang,Duong Dinh Tuan,Nguyen Van Huu Luong 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.5

In this study, heterogeneous catalytic ozonation using fl y ash (FA) modifi ed ZnO nanoparticles to the decolorization of acid orange II (AOII) was studied. The combination of ZnO and fl y ash via an incipient wetness impregnation method to form ZOFA composites created a synergistic eff ect that led to effi cient catalytic ozonation activity towards AOII degradation and decolorization compared with individual ozonation processes. From the experimental results, ZOFA composite with the optimal weight ratio between ZnO NPs and FA was 20 wt% (denoted as ZOFA-20) that exhibited outstanding catalytic ozonation activity. Moreover, through other investigations including initial pH conditions and catalyst dosage, AOII could be eff ectively and optimally eliminated by 0.5 g of ZOFA-20 with an initial pH value of 11. The corresponding k value was measured as 0.248 min −1 with a maximum TOC removal content of 77.27%. Besides, ZOFA-20 could show high catalytic ozonation activity even at highly concentrated AOII concentrations while it could also retain its excellent stability and reusability over 5 continuous AOII removal cycles. From the experimental and electron paramagnetic resonance (EPR) results, hydroxyl radical ( · OH) was the main active species during the catalytic ozonation of AOII. The present study provides a promising approach to prepare novel composite-based fl y ash that would be applicable for removing azo dye and other dye pollutants in water via a catalytic ozonation strategy.

Applications of Magnetite Nanoparticles for Water Treatment and for DNA and Cell Separation

Nguyen Hoang Hai,Nguyen Chau,Nguyen Hoang Luong,Nguyen Thi Van Anh,Phan Tuan Nghia 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3

Magnetic nanoparticles with a diameter of 15 nm prepared by using the coprecipitation method have been applied to enforce the sedimentation of the solid waste, to adsorb the arsenic ions in water, to increase the DNA concentration by using a magnetic eld for the electrochemical DNA sensor and to separate the helper CD4+ T cells to determine the number of the cells in blood. A combination of magnetic nanoparticles and alum makes the solid waste in water under a magnetic field aggregate a dozen times faster than under the gravity alone. A concentration of 0.1 mg/l of arsenic in water was reduced to a value lower than the permissible concentration of 0.01 mg/l after few minutes of stirring. The particles functionalized with 3-aminopropyl triethoxysilane were used to enrich the DNA of the Herpes virus, which extended the sensitivity of an electrochemical sensor down to a concentration lower than nM/l. The particles coated with fluorescent-labeled antiCD4 antibody were used to count the helper CD4+ T cells. The fluorescence signals of the particle/cell system were two times stronger than those of the uorescence antiCD4 cell system. This can be used for the treatment of an HIV-infected patient with a simple fluorescent microscope. Magnetic nanoparticles with a diameter of 15 nm prepared by using the coprecipitation method have been applied to enforce the sedimentation of the solid waste, to adsorb the arsenic ions in water, to increase the DNA concentration by using a magnetic eld for the electrochemical DNA sensor and to separate the helper CD4+ T cells to determine the number of the cells in blood. A combination of magnetic nanoparticles and alum makes the solid waste in water under a magnetic field aggregate a dozen times faster than under the gravity alone. A concentration of 0.1 mg/l of arsenic in water was reduced to a value lower than the permissible concentration of 0.01 mg/l after few minutes of stirring. The particles functionalized with 3-aminopropyl triethoxysilane were used to enrich the DNA of the Herpes virus, which extended the sensitivity of an electrochemical sensor down to a concentration lower than nM/l. The particles coated with fluorescent-labeled antiCD4 antibody were used to count the helper CD4+ T cells. The fluorescence signals of the particle/cell system were two times stronger than those of the uorescence antiCD4 cell system. This can be used for the treatment of an HIV-infected patient with a simple fluorescent microscope.