Some characters of bacterial cellulases in goats' rumen elucidated by metagenomic DNA analysis and the role of fibronectin 3 module for endoglucanase function

Nguyen, Khanh Hoang Viet,Dao, Trong Khoa,Nguyen, Hong Duong,Nguyen, Khanh Hai,Nguyen, Thi Quy,Nguyen, Thuy Tien,Nguyen, Thi Mai Phuong,Truong, Nam Hai,Do, Thi Huyen Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.5

Objective: Fibronectin 3 (FN3) and immunoglobulin like modules (Ig) are usually collocated beside modular cellulase catalytic domains. However, very few researches have investigated the role of these modules. In a previous study, we have sequenced and analyzed bacterial metagenomic DNA in Vietnamese goats' rumen and found that cellulase-producing bacteria and cellulase families were dominant. In this study, the properties of modular cellulases and the role of a FN3 in unique endoglucanase belonging to glycosyl hydorlase (GH) family 5 were determined. Methods: Based on Pfam analysis, the cellulases sequences containing FN3, Ig modules were extracted from 297 complete open reading frames (ORFs). The alkaline, thermostability, tertiary structure of deduced enzymes were predicted by AcalPred, TBI software, Phyre2 and Swiss models. Then, whole and truncated forms of a selected gene were expressed in Escherichia coli and purified by His-tag affinity column for assessment of FN3 ability to enhance enzyme activity, solubility and conformation. Results: From 297 complete ORFs coding for cellulases, 148 sequences containing FN3, Ig were identified. Mostly FN3 appeared in 90.9% beta-glucosidases belonging to glycosyl hydrolase family 3 (GH3) and situated downstream of catalytic domains. The Ig was found upstream of 100% endoglucanase GH9. Rarely FN3 was seen to be situated downstream of X domain and upstream of catalytic domain endoglucanase GH5. Whole enzyme (called XFN3GH5 based on modular structure) and truncate forms FN3, XFN3, FN3GH5, GH5 were cloned in pET22b (+) and pET22SUMO to be expressed in single and fusion forms with a small ubiquitin-related modifier partner (S). The FN3, SFN3 increased GH5 solubility in FN3GH5, SFN3GH5. The SFN3 partly served for GH5 conformation in SFN3GH5, increased modules interaction and enzyme-soluble substrate affinity to enhance SXFN3GH5, SFN3GH5 activities in mixtures. Both SFN3 and SXFN3 did not anchor enzyme on filter paper but exfoliate and separate cellulose chains on filter paper for enzyme hydrolysis. Conclusion: Based on these findings, the presence of FN3 module in certain cellulases was confirmed and it assisted for enzyme conformation and activity in both soluble and insoluble substrate.

Fabrication of a standalone MEA shell using silver nanowire

Nguyen Trung Hai(Hai Trung Nguyen),Ki Ju Kang(강기주) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.4

Development of label-free electrochemical lactose biosensor based on graphene/poly(1,5-diaminonaphthalene) film

Binh Hai Nguyen,Binh Thanh Nguyen,Hanh Van Vu,Chuc Van Nguyen,Dzung Tuan Nguyen,Loc Thai Nguyen,Thu Thi Vu,Lam Dai Tran 한국물리학회 2016 Current Applied Physics Vol.16 No.2

In this work, a lactose biosensor was developed by co-immobilizing b-galactosidase (b-Gal) and glucose oxidase (GOx) on microelectrodes pre-modified with Pt/graphene/P(1,5-DAN) for estimation of lactose in dairy products to prevent lactose intolerance. The Pt microelectrode was modified with graphene and 1,5-polydiaminonaphthalene film. Graphene was synthesized by chemical vapor deposition on copper tape and manually transferred to the electrode surface. Polymeric P(1,5-DAN) was grafted on top of the graphene film by electropolymerization. Modified surface of the electrode was characterized by Raman spectra analysis, FE-SEM, AFM and cyclic voltammetry. The results indicated that deposition graphene film on electrode surface induced considerable enhancement in current signal, over 20 times as high as the uncoated electrode surface. The developed sensor was successfully used to determine lactose in model samples with sensitivity, correlation coefficient (R2) and limit of detection (LOD) estimated to be 1.33 mA/(mgml1), 0.995 and 1.3 mg/ml, respectively. The combined graphene and conductive P(1,5-DAN) could serve as a novel sensing platform on electrochemical sensors with superior sensitivity.

The extraction of lignocelluloses and silica from rice husk using a single biorefinery process and their characteristics

Ngoc Thuy Nguyen,Nhat Thong Tran,Tan Phat Phan,Anh Thu Nguyen,My Xuyen T. Nguyen,Nguyen Ngan Nguyen,Young Ho Ko,Dai Hai Nguyen,Tran T.T. Van,DongQuy Hoang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

While the efficient usage of biomass waste can significantly help in addressing environmental issues,there are only a few reports that discuss about processing such waste effectively at a low-cost. Such challengearises from the strong association between the components biomass. In this study, an abundantagricultural byproduct, rice husk (RH), was used as the starting resource. A simple biorefining processof alkaline peroxide treatment followed by acid precipitation and ethanol extraction was performed onRH to obtain cellulose, hemicellulose, lignin, and silica. The chemical structures, morphologies, andphysic-chemical properties of the separated components were identified through a wide range of characterizationapproaches. The final products obtained from of this process were (i) bundles of fiber-likecellulose with a fiber width of 6 mm and (ii) small particles of hemicellulose and lignin with nonuniformshapes. The lignocelluloses products had over 90 wt% carbon with 52.28% crystalline ratio. Meanwhile, the other products comprising hemicelluloses, lignin, and silica were amorphous. The outcomeof this study contributes to expanding and developing the simple and efficient conversion processof biomass waste into sustainable value-added materials. It is crucial to reduce the environmental impactby using renewable materials as the new building block resources for synthetic chemicals.

Parenchymal-sparing anatomical hepatectomy based on portal ramification of the right anterior section: A prospective multicenter experience with short-term outcomes

Truong Giang Nguyen,Thanh Khiem Nguyen,Ham Hoi Nguyen,Hong Son Trinh,Tuan Hiep Luong,Minh Trong Nguyen,Van Duy Le,Hai Dang Do,Kieu Hung Nguyen,Van Minh Do,Quang Huy Tran,Cuong Thinh Nguyen 한국간담췌외과학회 2024 Annals of hepato-biliary-pancreatic surgery Vol.28 No.1

Backgrounds/Aims: Parenchymal-sparing anatomical hepatectomy (Ps–AH) based on portal ramification of the right anterior section (RAS) is a new technique to avoid unnecessarily transecting too much liver parenchyma, especially in cases of major anatomical hepatectomy. Methods: We prospectively assessed 26 patients with primary hepatic malignancies having undergone major Ps–AH based on portal ramification of the RAS from August 2018 to August 2022 (48 months). The perioperative indications, clinical data, intra-operative index, pathological postoperative specimens, postoperative complications, and follow-up results were retrospectively evaluated. Results: Among the 26 patients analyzed, there was just one case that had intrahepatic cholangiocarcinoma The preoperative level of α– Fetoprotein was 25.2 ng/mL. All cases (100%) had Child–Pugh A liver function preoperatively. The ventral/dorsal RAS was preserved in 19 and 7 patients, respectively. The mean surgical margin was 6.2 mm. The mean surgical time was 228.5 minutes, while the mean blood loss was 255 mL. In pathology, 5 cases (19.2%) had microvascular invasion, and in the group of HCC patients, 92% of all cases had moderate or poor tumor differentiation. Six cases (23.1%) of postoperative complications were graded over III according to the Clavien–Dindo system, including in three patients resistant ascites or intra-abdominal abscess that required intervention. Conclusions: Parenchymal-sparing anatomical hepatectomy based on portal ramification of the RAS to achieve R0-resection was safe and effective, with favorable short-term outcomes. This technique can be used widely in clinical practice.

Two New C-Glucosyl Benzoic Acids and Flavonoids from Mallotus nanus and Their Antioxidant Activity

Phan Van Kiem,Nguyen Thi Mai,Chau Van Minh,Nguyen Huu Khoi,Nguyen Hai Dang,Nguyen Phuong Thao,Nguyen Xuan Cuong,Nguyen Hoai Nam,Nguyen Xuan Nhiem,Yvan Vander Heyden,Joëlle Quetin-Leclercq,김교남,장해동,김영호 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.2

Two new 2-C-β-D-glucopyranosyl benzoic acid derivatives named mallonanosides A (1) and B (2) were isolated from the methanolic extract of the leaves of Mallotus nanus along with five known flavonoids, kaempferin (3), juglanin (4), quercitrin (5), myricitrin (6), and rhoifolin (7). Their structures were established on the basis of spectral and chemical evidence. Their antioxidant activities were shown to depend on the number of hydroxyl groups, and the location and species of sugar moiety.

Synthesis and Characterization of TiO₂ Nanoparticles by DC Thermal Plasma System

Nguyen Hoang Hai,Kyo-Seon Kim 강원대학교 환경연구소 2010 Journal of the Environment Vol.7 No.-

This study examined the synthesis of TiO₂ nanoparticles by direct current thermal plasma system at atmospheric pressure, using titanium tetra iso propoxide as titanium precursor. We investigated the effects of important process variables of flow rate of raw materials and supplied power on the particle composition, size and morphology by observing XRD and TEM measurements. The TiO₂ nanoparticles collected at the reaction tube have more rutile phase than anatase with the particle size around 250 ㎚.

The Effect of Perceived Organizational Support on Employee Engagement During the COVID-19 Pandemic

Hai Ninh NGUYEN,Manh Dung TRAN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.6

Employee engagement at workplace is very important for organizations, however, the motivators to keep the employees engaged vary. It has been normally observed that personality and job satisfaction has been the main causes which can motivate employees. However, the COVID-19 pandemic has brought a lot of changes, and the main aim of this study is to analyze the determinants of employee engagement during Covid-19 pandemic with the mediating role of Perceived organizational support and Perceived family support. Through a survey instrument, data was collected from 216 employees working at corporate offices in Hanoi, Vietnam. Partial least squares structural equation modeling (PLS-SEM) was applied to test the study hypotheses using Smart-PLS. The study underlined the significant positive effect of Perceived Organizational support and Perceived Family Support on Employee Engagement. Moreover, Employee engagement also measures the indirect effects from factors such as colleague support, supervisor support, organizational support, spousal support and family members supports on Employee Engagement. Some discussions are given based on the findings of this research in comparison with findings of prior studies in different contexts. This research is evidenced in the emerging countries and Vietnam as the case study.

Antecedents and Consequences of Brand Hate Among Netizens: Empirical Evidence from Vietnam

Hai Ninh NGUYEN 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.7

In the era of tough competition, the customer’s emotional attachment to brand plays a vital role to the successes and failures of enterprises. Specifically in the case of doing business online, brands have to cope with the troubles of rising from brand hate as brand avoidance, negative word of mouth and brand retaliation. Traditionally, the brand communication is very hard to control and with online communities, the problems tend to be even more severe. This paper aims to explore and discuss the core concept, the driven factors and the actionable consequences of brand hate among netizens. A total of 358 valid responses were obtained from surveys taken from the internet users across the nation. Partial Least Square – Structural Equation Modeling (PLS-SEM) was conducted using Smart PLS to assess the hypotheses. The result shows that the expression of brand hate among netizen consists of active hate and passive hate. Deficit value, deceptive advertising, negative past experience and ideology incompatibility have been confirmed as influencing factors on customers’ brand hate emotion. Then brand hate itself causes the customer’s actionable outcomes such as brand avoidance, brand negative word of mouth and brand retaliation. Along with the theoretical contributions and managerial implications have been recommended for enterprises to avoid netizens’ brand hate.

Factors Affecting Efficiency of Electronic Customs and Firm Performance in Vietnam

NGUYEN, Hang Thanh,GRANT, David Bruce,BOVIS, Christopher,NGUYEN, Thuy Thi Le,MAC, Yen Thi Hai Korea Distribution Science Association 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.2

The paper identifies the enablers (drivers) and inhibitors (barriers) influencing e-customs implementation in Vietnam (known as a developing country with a lower technological environment) along with determining the impact of e-customs on firm performance. The survey was conducted with the representatives (managers) of firms in five cities and provinces dominating Vietnam's international trade. The data was analyzed using structural equation modeling (SEM). The findings show two significant drivers (enablers) - relative advantages and national culture, while compatibility and ease of use are the barriers. Previous studies showed that cultural dimensions related to 'uncertainty acceptance' and 'individualism' encourage innovation; however, this paper demonstrates that 'uncertainty avoidance' and 'collectivism' promote e-customs deployment in Vietnam. Previously, Vietnamese culture was known for scoring high on cultural dimensions related to 'power distance' and 'short-term orientation'. However, today, as an emerging country, Vietnamese has switched to 'low distance' and 'long-term orientation', especially in terms of e-customs innovation. Additionally, the paper also emphasized that e-customs implementation had a positive influence on firm performance in Vietnam. Based on the results of the paper, policy-makers can devise essential solutions to enhance e-customs implementation as well as managers of firms can set-up strategies to adapt to the modernized environment.