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.

Influence of the Deformation on the Microstructure and Mechanical Properties of TBF Steel

Nguyen Duong Nam,Tran Phap Dong,Tran The Nam,Nguyen Hong Hai,Pham Mai Khanh Korean Society for Precision Engineering 2020 한국정밀공학회지 Vol.37 No.8

A highly sensitive fluorescent chemosensor for simultaneous determination of Ag(I), Hg(II), and Cu(II) ions: Design, synthesis, characterization and application

Hien, Nguyen Khoa,Bao, Nguyen Chi,Ai Nhung, Nguyen Thi,Trung, Nguyen Tien,Nam, Pham Cam,Duong, Tran,Kim, Jong Seung,Quang, Duong Tuan Elsevier 2015 Dyes and pigments Vol.116 No.-

<P><B>Abstract</B></P> <P>A fluorescent chemosensor based on dimethylaminocinnamaldehyde-aminothiourea (DA) has been designed, synthesized, and applied with a combined theoretical and experimental study. The synthetic path, optimized molecular structure and characteristics of DA were carried out using the calculations at the B3LYP/LanL2DZ level of theory. The experimental investigations have a good agreement with the theoretical results. DA can be used as a chemosensor for simultaneous quantification of silver, copper, and mercury ions in aqueous solution at the ppb level. The stable geometric structures of the complexes between DA and Ag<SUP>+</SUP>, Hg<SUP>2+</SUP>, Cu<SUP>2+</SUP> with stoichiometry of 1:1, 2:1, and 2:1, have been found and investigated for electronic properties and fluorescence quenching phenomena by using Atoms in Molecules (AIM) and Natural Bond Orbitals (NBO) analyses.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A chemosensor has been studied with a combined theoretical and experimental study. </LI> <LI> Suitable for detecting trace amounts of Ag(I), Hg(II), Cu(II) ions at the ppb concentration level. </LI> <LI> High water solubility, simplicity, rapid analysis time, wide range of pH. </LI> <LI> The stable geometric structures of the complexes have been found and investigated. </LI> <LI> The fluorescence quenching of complexes is studied by using AIM and NBO analyses. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Facile synthesis of multifunctional Ag/Fe3O4-CS nanocomposites for antibacterial and hyperthermic applications

Ngoan Thi Nguyen,Dai Lam Tran,Duc Cuong Nguyen,Thai Loc Nguyen,Thi Cham Ba,Binh Hai Nguyen,Thi Duong Ba,Nam Hong Pham,Dzung Tuan Nguyen,Thai Hoa Tran,Gia Dien Pham 한국물리학회 2015 Current Applied Physics Vol.15 No.11

Nanocomposites containing two or more functional constituents are attractive candidates for advanced nanomaterials. In this study, multifunctional Ag/Fe3O4-CS nanocomposites were successfully prepared, using chitosan as a stabilizing and cross-linking agent. The as-synthesized nanocomposites were characterized by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), UVevisible spectrophotometer (UVeVis) and vibrating sample magnetometer (VSM). The results demonstrated that Ag/Fe3O4-CS composite nanoparticles (NPs) were composed of parent components, Fe3O4 and Ag NPs, which were uniformly dispersed in the chitosan matrix. The hybrid NPs exhibited strong antibacterial property against Pseudomonas aeruginosa. With high magnetization value (67 emu/g), the synthesized Ag/Fe3O4-CS composite can be easily separated or recycled in potential biomedical applications. Furthermore, the results showed that the multicomponent hybrid nanostructures appeared to be the promising material for local hyperthermia, which can be used as thermoseeds for localized hyperthermia treatment of cancers.

Vingroup: The Rising Dragon That Put Vietnam on the Global Map

Giap Vu Nam Duong,Hoang Khanh Linh,정경화,Nguyen Khanh Linh,Nguyen Phuong Hoa,Phan Hai Dang,Thai Thi Phuong Nga Academy of Asian Business (AAB) 2022 Academy of Asian Business Review Vol.8 No.1

Vingroup JSC (formerly Technocom) was founded in Ukraine in 1993 as an instant noodle factory. Since then, the Group has expanded into many other industries, placing tourism and hospitality as their first stepping-stone, then venturing into retail, real estate, education, and recently shifting towards a promising industrial and technology industry. Vingroup has now become the largest conglomerate in Vietnam in terms of market capitalization (VnExpress International, 2019). Having established a solid foundation in the Vietnamese market, Vingroup is eyeing the new promising yet challenging international market, with its competitive advantage in industrials and technology. Standing at a crucial juncture in its ascent, the conglomerate must implement a comprehensive and long-term strategy to reach its next milestone. In 2016, Vingroup primarily focused on four main business segments, encompassing property, hospitality - entertainment, consumer retail, and social infrastructure services. Over the course of two decades, Vinpearl and Vincom have grown into the market-leading hospitality and shopping malls brand in Vietnam. The brands’ establishment coincided with the flourishing economy of the country in the early 2000s, therefore, quickly achieved market dominance. Having such favorable conditions, the Group continued its expansion and investment in other backboned industries, which has reaped correspondingly fruitful results. The key success factors of Vingroup lies in an entrepreneurial mindset, speed, perfectionism and discipline, and last but not least, the national spirit. These traits have allowed the Group to unleash its potential capabilities and go beyond all boundaries. Both small-and-medium-sized companies and big firms can take Vingroup as a lesson for their strategy and corporate culture so that they can lead successful and sustainable growth in today’s competitive market.

An Efficient Precoder Design for Multiuser MIMO Cognitive Radio Networks With Interference Constraints

Nguyen, Van-Dinh,Tran, Le-Nam,Duong, Trung Q.,Shin, Oh-Soon,Farrell, Ronan IEEE 2017 IEEE Transactions on Vehicular Technology VT Vol.66 No.5

<P>We consider a linear precoder design for an underlay cognitive radio multiple-input multiple-output (MIMO) broadcast channel, where the secondary system consisting of a secondary base station (BS) and a group of secondary users is allowed to share the same spectrum with the primary system. All the transceivers are equipped with multiple antennas, each of which has its own maximum power constraint. Assuming zero-forcing (ZF) method to eliminate the multiuser interference, we study the sum rate maximization problem for the secondary system subject to both per-antenna power constraints at the secondary BS and the interference power constraints at the primary users. The problem of interest differs from the ones studied previously that often assumed a sum power constraint and/or single antenna employed at either both the primary and secondary receivers or the primary receivers. To develop an efficient numerical algorithm, we first invoke the rank relaxation method to transform the considered problem into a convex–concave problem based on a downlink-uplink result. We then propose a barrier interior-point method to solve the resulting saddle point problem. In particular, in each iteration of the proposed method we find the Newton step by solving a system of discrete-time Sylvester equations, which help reduce the complexity significantly, compared to the conventional method. Simulation results are provided to demonstrate fast convergence and effectiveness of the proposed algorithm.</P>

Structural and Magnetic Properties of (A<SUB>0.5</SUB>Zn<SUB>0.5</SUB>)Fe₂O₄(A=Mn, Co, Ni) Ferrite Nanoparticles

Duong The Bao,Hoang Nam Nhat,Nguyen Chau,Bui Doan Huan,Huynh Dang Chinh 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Lyapunov-Based Nonlinear Model Predictive Control for Attitude Trajectory Tracking of Unmanned Aerial Vehicles

Duy Nam Bui,Thi Thanh Van Nguyen,Manh Duong Phung 한국항공우주학회 2023 International Journal of Aeronautical and Space Sc Vol.24 No.2

This paper presents a new Lyapunov-based nonlinear model predictive controller (LNMPC) for the attitude control problem of unmanned aerial vehicles (UAVs), which is essential for their functioning operation. The controller is designed based on a quadratic cost function integrating UAV dynamics and system constraints. An additional contraction constraint is then introduced to ensure closed-loop system stability. That constraint is fulfilled via a Lyapunov function derived from a sliding mode controller (SMC). The feasibility and stability of the LNMPC are finally proved. Simulation and comparison results show that the proposed controller guarantees the system stability and outperforms other state-of-the-art nonlinear controllers, such as the backstepping controller and SMC. In addition, the proposed controller can be integrated into an existing UAV model in the Gazebo simulator to perform software-in-the-loop tests. The results show that the LNMPC is better than the built-in proportional–integral–derivative controller of the UAV, which confirms the validity and applicability of our proposed approach.

Room-Temperature Synthesis of Widely Tunable Formamidinium Lead Halide Perovskite Nanocrystals

Minh, Duong Nguyen,Kim, Juwon,Hyon, Jinho,Sim, Jae Hyun,Sowlih, Haneen H.,Seo, Chunhee,Nam, Jihye,Eom, Sangwon,Suk, Soyeon,Lee, Sangheon,Kim, Eunjoo,Kang, Youngjong American Chemical Society 2017 Chemistry of materials Vol.29 No.13

<P>Colloidal perovskite nanocrystals based on formamidinium lead halide (FAPbX(3)) have been synthesized by the ligand-assisted reprecipitation method using PbX2-dimethyl sulfoxide complexes as precursors at room temperature. Well-defined cubicshaped FAPbX(3) nanocrystals have been obtained with a size d of similar to 10 nm. The synthesized FAPbX(3) nanocrystals show bright photoluminescence with a high photoluminescence quantum yield (75% for FAPbBr(3)). The lifetimes of FAPbBr(3) nanocrystals were measured for the samples isolated at several different centrifugal speeds. The photoluminescence can be tuned from the blue to near infrared region (lambda(peak) = 408-784 nm) by changing either the amount of oleylamine or the composition of X. The color expression range is 135% of the NTSC standard. The bandwidth of the photoluminescence spectra of FAPbX(3) nanocrystals is narrow (full width at half-maximum of 18-48 nm). FAPbX(3) nanocrystals show thermal stability that is better than that of MAPbBr(3) nanocrystals.</P>

An Advanced Celestial Method to Determine Ship’s Position by Simultaneous Observation of Altitude and Azimuth of the Sun

Thai-Duong NGUYEN,Tu-Nam LUONG 국제이네비해양경제학회 2021 International Journal of e-Navigation and Maritime Vol.16 No.1

A ship’s position as determined by the observation of celestial bodies is a traditional method with important advantages, such as reliability, independence and a low cost. Global satellite navigation systems, with many outstanding advantages in terms of accuracy and continuity, have become the main method of ship positioning in offshore navigation. Ship positioning using celestial body observation is still a backup method in the event of unusual incidents. Currently, during the daytime, it is only possible to apply the celestial navigation method to determine the ship’s position by observing the altitude of the sun. In order to reduce geometrical errors, this traditional method requires time for a certain change of the azimuth of the sun and therefore depends much on estimated errors and the effects of external conditions. Moreover, the basic requirement of the backup method is to provide a ship position quickly during offshore navigation, without the position being determined by a global satellite positioning system. To overcome the above limitations, the paper proposes a new approach to determine a ship's position by simultaneously observing the altitude and azimuth of the sun. A program for calculating the position of a ship with high reliability and applicability based on the new algorithm is also devised and shown to be highly effective in practice.