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.

3D-Brain MRI Segmentation Based on Improved Level Set by AI Rules and Medical Knowledge Combining 3 Classes-EM and Bayesian Method

Nguyen Ho Minh Duy,Tran Anh Tuan,Nguyen Hai Duong,Tran Anh Tuan,Nguyen Kim Dao,Atsuo Yoshitaka,Jin Young Kim,Seung Ho Choi,Pham The Bao 한국정보기술학회 2016 한국정보기술학회논문지 Vol.14 No.5

MRI and CT images are the most popular formats assisting a doctor in diagnosis and treatment, but highly accurate segmentation is a challenging problem due to intensity inhomogeneity and environmental noises. In this paper, we introduce an appropriate and effective automatic approach to facilitate this problem in two stages. In the first stage, skull region is removed from the brain by morphological active contour and level set process. Moreover, in level set process, some AI rules are defined on slice positions of brain to increase the accuracy. In the second stage, a modified EM method is performed on the resultant skull-stripping image to identify some candidate main regions of CSF (cerebro-spinal fluid), GM (gray matter), and WM (white matter). The candidate regions are then re-estimated into the proper CSF, GM, and WM through a Bayesian Estimation Process. The experimental results show that the proposed approach obtains a robust segmentation for IBSR, OASIS and Korean Hospital database. With the proposed AI-rules, the level set method gets good skull-stripping images regardless of MRI slice position in bran. Also, Bayesian postprocessing can improve the segmentation performance by 10~15% in CSF, GM and WM ratios compared the basic EM algorithm.

Large Magnetocaloric Effect above 300 K and Magnetoresistance in (La0.5Pr0.5)1-xPbxMnO3 Perovskites

Nguyen Chau,Duong Thi Hanh,Bui Cong Tinh,Nguyen Hoang Luong,Nguyen Duc Tho,Nguyen Hoang Hai 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

Perovskite compounds (La0.5Pr0.5)₁- xPbxMnO₃ (x = 0.1 - 0.5) with orthorhombic structure were prepared by using a solid-state reaction technique. In the studied samples, the spin-glass-like state occurs at low temperatures and the Curie temperature, Tc, increases from 170 K (x = 0.1) to 336 K (x = 0.5) because of a strong double exchange. The magnetic entropy change, │△Sm│, reached its largest value of 2.06 J/kg·K at △H = 13.5 kOe for the sample with x = 0.4 (Tc = 323 K). Due to the large │△Sm│ and high Tc, these materials are suggested for use as active magnetic refrigerants for magnetic refrigeration technology at temperatures above room temperature. While the conductivity of the samples with x = 0.1 and 0.2 exhibits only a semiconducting behavior over the whole measured temperature range, there is insulator-metallic phase transition on the R(T) curves of the samples with x = 0.3 - 0.5. The magnetoresistance of the samples was measured and large values for MR were found. Perovskite compounds (La0.5Pr0.5)₁- xPbxMnO₃ (x = 0.1 - 0.5) with orthorhombic structure were prepared by using a solid-state reaction technique. In the studied samples, the spin-glass-like state occurs at low temperatures and the Curie temperature, Tc, increases from 170 K (x = 0.1) to 336 K (x = 0.5) because of a strong double exchange. The magnetic entropy change, │△Sm│, reached its largest value of 2.06 J/kg·K at △H = 13.5 kOe for the sample with x = 0.4 (Tc = 323 K). Due to the large │△Sm│ and high Tc, these materials are suggested for use as active magnetic refrigerants for magnetic refrigeration technology at temperatures above room temperature. While the conductivity of the samples with x = 0.1 and 0.2 exhibits only a semiconducting behavior over the whole measured temperature range, there is insulator-metallic phase transition on the R(T) curves of the samples with x = 0.3 - 0.5. The magnetoresistance of the samples was measured and large values for MR were found.

Optimizing the Carrier Density and Thermoelectric Properties of Sb2Te3 Films by Using the Growth Temperature

Duong Van Thiet,NGUYENVAN QUANG,Nguyen Thi Minh Hai,Nguyen Thi Huong,조성래,Duong Anh Tuan,Dang Duc Dung,트란반탐 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.8

In this work, we report on the structural and thermoelectric properties of Sb2Te3 films deposited on GaSb(111) substrates by using molecular beam epitaxy. The effects of the growth temperature on the microstructure and thermoelectric properties of the films were investigated. The results show that Sb2Te3 films grow on GaSb(111) along (00l) axis normal to the substrate and have a hexagonal structure with a layer-by-layer growth mode in growth temperature range from 200 to 250 °C while at 175 and 300 °C, the films show an island growth mode. Te and Sb2Te3 phases coexist at a growth temperature of 175 °C. The films exhibit a metallic behavior for growth temperatures below 250 °C and a semiconductor behavior at 300 °C. By changing growth temperature, we were able to vary the carrier density from 9.96×1018 to 4.55×1019 cm −3. At room temperature, the Seebeck coefficients are 110, 146, and 138 μV/K for growth temperatures of 175, 200 and 250 °C, respectively, and a large value of the power factor 61.67 μW/cm-K2 is achieved for the film grown at 250 °C.

MBE growth and magnetic properties of epitaxial FeMn2O4 film on MgO(100)

Duong Van Thiet,Nguyen Thi Minh Hai,Nguyen Anh Phuong,Dang Duc Dung,Duong Anh Tuan,Nguyen Van Quang,Sunglae Cho 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.2

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

The article presents the influence of the deformation process on the microstructure and mechanical properties of low carbon alloy steel which heat treatment by TBF processing. When the samples are deformed at different levels: 20, 40, and 80%. The research results show that when the sample was deformed with the 80%, the highest strength was 800 MPa, the highest elongation was 36%, the product between the strength and the elongation (Rm*A) was the highest, 28774 MPa*%. This alloy deformed at a level of 80%, the content of austenite in this microstructure of this alloy was the highest about 16%. The content of ferrite was 52% with the average particle size of ferrite was 6.4 μm, the particle of residual austenite was 2 μm. The results of the microstructure have contributed to improving the mechanical properties of steel. The phase which was improved the mechanical properties of this alloy had grain size and dispersed.

Growth and electrical properties of SnS1-xSex (0 ≤ x ≤ 1) single crystals grown using the temperature gradient method

Nguyen Thi Minh Hai,Van Nguyen Quang,Duong Anh Tuan,Cho Sunglae 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.78 No.11

Tin selenide (SnSe) has attracted much attention due to its record ZT value in both pristine and doped crystals. This issue has renewed interest in the single-crystal form of tin-based chalcogenide compounds which possess the same layered structure as SnSe such as tin sulfide (SnS). Due to their natural abundances and low toxicities, SnSe and SnS can be alloyed at reduced the processing cost while maintaining the favorable electrical properties of SnSe. In this research, using the temperature gradient method, we successfully fabricated single crystals of SnS1-xSex with 0 ≤ x ≤ 1. High-quality crystals were obtained, and the electrical properties of those crystals were investigated. The results showed that the p-type crystals have layered structures with lattice constants changing gradually according to Vegard’s law. The value of the band gap monotonically decreased with increasing Se amount (x). The substitution of Se into S sites results in not only a large increase in the electrical conductivity but also a decrease in the Seebeck coefficient; i.e., the electrical conductivity at room temperature increased from 5 × 10– 4 (x = 0) to 5.24 S⋅cm−1 (x = 0.8). The Seebeck coefficient decreased from 1069 in SnS to 525 μVK−1 in SnS0.2Se0.8 and to 481 μVK−1 in SnSe at room temperature. This work provides positive information for the growth of large-size SnS–SnSe single crystals.

Composites derived from synthetic clay and carbon sphere: Preparation, characterization, and application for dye decontamination

Nguyen Duy Dat,Ton That Loc,Mai Thuan Trieu,Dong Thanh Nguyen,Khuong Quoc Nguyen,My Linh Nguyen,Anh Duy Duong Le,Hai Nguyen Tran 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.4

Two new composites from synthetic clay-like materials and carbon spheres were developed. Layered doubledhydroxides (LDH) were synthesized from the coprecipitation of Mg2+ and Al3+ ions. Spherical hydrochar (SH) wasprepared from pure glucose through hydrothermal carbonization at 190 oC. The composite LDH–SH was synthesizedthrough a simple hydrothermal method of the mixture of LDH and SH. Another composite, LDO-SB, was directly preparedthrough the carbonization of LDH-SH at 500 oC. Under such high temperature, LDH was converted to layereddoubled oxides (LDO), and SH was transferred to spherical biochar (SB). Those materials were characterized by chemicalstability, surface morphology and element composition, crystal structure, surface functional group, and texturalcharacteristic. They were applied for removing cationic dye (methylene blue; MB) and anionic dye (Congo red; CR)under different pH solutions. Three adsorption components—kinetics, isotherm, and thermodynamics—were conductedunder batch experimenters. Results demonstrated that the LDH or LDO particles were assembled on the surfaceof SH or SB, respectively. The surface area, total pore volume, and average pore width of LDH–SH and LDO-SBwere 58.5 and 198m2/g, 0.319 and 0.440 cm3/g, and 21.8 and 8.89 nm, respectively. The maximum adsorption capacityof the materials, calculated from the Langmuir model, at 30 oC for CR and MB dyes was 1589 and 78.6mg/g (LDOSB)and 499 and 226mg/g (LDH-SH), respectively. The composites exhibited a higher affinity to anionic than cationicdyes, which resulted from the great contribution of the clay-like materials. Therefore, they can serve as a promisingcomposite for the decolorization of wastewater.

Multiple human tracking in drone image

Nguyen, Hai Duong,Na, In Seop,Kim, Soo Hyung,Lee, Guee Sang,Yang, Hyung Jeong,Choi, Jun Ho Springer-Verlag 2019 MULTIMEDIA TOOLS AND APPLICATIONS Vol.78 No.4

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.