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.

Zanthoxylum rhetsa Stem Bark Extract Inhibits LPS-induced COX-2 and iNOS expression in RAW 264.7 Cells via the NF-kB Inactivation

Nguyen Bich Thu,Trinh Nam Trung,Do Thi Ha,Nguyen Minh Khoi,Nguyen Viet Than,Thipthaviphone Soulinho,Nguyen Hai Nam,Tran Thi Phuong,배기환 한국생약학회 2010 Natural Product Sciences Vol.16 No.4

The methanol extract of Zanthoxylum rhetsa (MZRR) were evaluated for its ability to suppress the formation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. MZRR presented an inhibition of LPS-induced production of nitric oxide (NO) and prostaglandin E2 (PGE2) in RAW 264.7 macrophages. Western blotting and RT-PCR analyses demonstrated that MZRR significantly inhibited the protein and mRNA expressions of iNOS and COX-2 in LPS-activated macrophages in a dose-dependent manner. LPS-induced COX-2, iNOS, and nuclear factor kappa beta (NF-kB) activity were also decreased in the presence of MZRR. The production of tumor necrosis factor-a (TNF-a), the mRNA expression levels of pro-inflammatory cytokines, including TNF-a and IL-1b, were reduced after MZRR administration in a dose dependent-manner. These results suggest that the MZRR extract involved in the inhibition of iNOS and COX-2 via the NF-kB pathway, revealing a partial molecular basis for anti-inflammatory properties of the MZRR extract.

Outcomes of liver transplantation for hepatocellular carcinoma: Experiences from a Vietnamese center

Khai Viet Ninh,Dang Hai Do,Trung Duc Nguyen,Phuong Ha Tran,Tuan Hoang,Dung Thanh Le,Nghia Quang Nguyen 한국간담췌외과학회 2024 Annals of hepato-biliary-pancreatic surgery Vol.28 No.1

Backgrounds/Aims: Liver transplantation (LT) provides a favorable outcome for patients with hepatocellular carcinoma (HCC) and was launched in Vietnam in 2004. In this study, we evaluated the short-term and long-term outcomes of LT and its risk factors. Methods: This retrospective study analyzed HCC patients who underwent LT at Viet Duc University hospital, Vietnam, from 01/2012–03/2022. The following data were gathered: demographics, virus infection, tumor characteristics, alpha-fetoprotein (AFP) level, Child-Pugh and MELD scores, selection criteria, type of LT, complications, 30-day mortality, and disease-free and overall survival (DFS and OS). Results: Fifty four patients were included, the mean age was 55.39 ± 8.46 years. Nearly 90% had hepatitis B virus-related HCC. The median (interquartile range) AFP level was 16.2 (88.7) ng/mL. The average MELD score was 10.57 ± 5.95; the rate of Child-Pugh A and B were 70.4% and 18.5%, respectively. Nearly 40% of the patients were within Milan criteria, brain-dead donor was 83.3%. Hepatic and portal vein thrombosis occurred in 0% and 1.9%, respectively; hepatic artery thrombosis 1.9%, biliary leakage 5.6%, and postoperative hemorrhage 3.7%. Ninety-day mortality was 5.6%. Five-year DFS and OS were 79.3% and 81.4%, respectively. MELD score and Child- Pugh score were predictive factors for DFS and OS (p < 0.05). In multivariate analysis, Child-Pugh score was the only significant factor (p < 0.05). Conclusions: In Vietnam, LT is an effective therapy for HCC with an acceptable complication rate, mortality rate, and good survival outcomes, and should be further encouraged.

Enzyme-mediated fabrication of an oxidized chitosan hydrogel as a tissue sealant

Phuong, Nguyen Thi,Anh Ho, Viet,Hai Nguyen, Dai,Khoa, Nguyen Cuu,Quyen, Tran Ngoc,Lee, Yunki,Park, Ki Dong Technomic Pub. Co 2015 Journal of bioactive and compatible polymers Vol.30 No.4

<P>Oxidized polysaccharide-based hydrogels have recently attracted much attention for tissue regeneration because of their biocompatibility and tissue-adhesive property. In this study, we introduce a new type of chitosan-based hydrogel as a tissue sealant, which was prepared by enzymatic mediation from periodate-oxidized chitosan–polyethylene glycol–tyramine. The oxidized chitosan backbone was expected to enhance the interconnection between the hydrogel layer and collagen in the tissues via the Schiff-base reaction. Proton nuclear magnetic resonance spectra indicated that tyramine-functionalized polyethylene glycol-nitrophenyl carbonate ester was conjugated to the oxidized chitosan. The degree of oxidation of the chitosan backbone was around 14% of the glucosamine units by proton nuclear magnetic resonance. The hydrogel was rapidly formed in situ (within a few seconds) in the presence of horseradish peroxidase and hydrogen peroxide. In vitro experiments with live/dead cell assays showed that the oxidized chitosan-based hydrogel was cytobiocompatible. The hydrogel exhibited high tissue adhesion strength on porcine skin models as well as good tissue-adhesive ability and wound healing properties on rabbit skin. These positive results could be promising for the application of oxidized chitosan-based hydrogels as a wound sealant.</P>

Effect of Extreme Rainfall on Cut Slope Stability

Tran The Viet,Trinh Minh Thu,Giha Lee,Sewook Oh,Nguyen Thi Hai Van 한국지반환경공학회 2015 한국지반환경공학회논문집 Vol.16 No.4

This paper addresses the effects of extreme rainfall on the stability of cut slopes in Yen Bai city, Northern Viet Nam. In this area, natural slopes are excavated to create places for infrastructures and buildings. Cut slopes are usually made without proper site investigations; the design is mostly based on experience. In recent years, many slope failures have occurred along these cuts especially in rainy seasons, resulting in properties damaged and loss of lives. To explain the reason that slope failure often happens during rainy seasons, this research analyzed the influence of extreme rainfalls, initial ground conditions, and soil permeability on the changes of pore water pressure within the typical slope, thereafter determining the impact of these changes on the slope stability factor of safety. The extreme rainfalls were selected based on all of the rainfalls triggering landslide events that have occurred over the period from 1960 to 2009. The factor of safety (FS) was calculated using Bishop’s simplified method. The results show that when the maximum infiltration capacity of the slope top soil is less than the rainfall intensity, slope failures may occur 14 hours after the rain starts. And when this happens, the rainfall duration is the deciding factor that affects the slope FS values. In short, cut slopes in Yen Bai may be stable in normal conditions after the excavation, but under the influence of tropical rain storms, their stability is always questionable.

Whole-exome sequencing identifies two novel missense mutations (p.L111P and p.R3048C) of RYR3 in a Vietnamese patient with autism spectrum disorders

Thu Hien Nguyen,Thi Thanh Ngan Nguyen,Bac Viet Le,Ngoc Minh Thanh,Thi Kim Lien Nguyen,Van Hai Nong,Huy Hoang Nguyen 한국유전학회 2017 Genes & Genomics Vol.39 No.3

Autism spectrum disorders (ASDs) are a group of neurodevelopmental disorders characterized by ritualistic- repetitive behaviors and impaired verbal and non-verbal communication. Boys are more likely to be diagnosed with ASD than girls. Genetics have been shown to play a key role in the etiology of autism. Many genes were found to be implicated in the inheritance of idiopathic autism. Analysis of mutation abnormalities associated with autism contributes significantly to the identification of autism candidate genes. Whole-exome sequencing has been shown as an application of the next generation sequencing technology used to determine the variations of all coding regions, or exons of the known genes. In the present study, we have found two novel heterozygous missense mutations (p.L111P and p.R3048C) on the RYR3 gene, which was located in the autism susceptibility region (15q14-q15) in a 9-year-old boy with ASD. Therefore, the sequence missense mutations provide the first suggestive link between a genetic abnormality in the RYR3 gene and a neurodevelopmental disorder.

Enhanced electrosorption of NaCl and nickel(II) in capacitive deionization by CO2 activation coconut-shell activated carbon

Huynh Le Thanh Nguyen,Tran Thanh Nhut,Ho Thi Thanh Nguyen,Le Xuan Hoa,Le Viet Hai,Nguyen Thai Hoang 한국탄소학회 2022 Carbon Letters Vol.32 No.6

Enhancing the capacitive deionization performance requires the inner structure expansion of porous activated carbon to facilitate the charge storage and electrolyte penetration. This work aimed to modify the porosity of coconut-shell activated carbon (AC) through CO2 activation at high temperature. The electrochemical performance of CO2-activated AC electrodes was evaluated by cyclic voltammetry, charge/discharge test and electrochemical impedance spectroscopy, which exhibited that AC-800 had the superior performance with the highest capacitance of 112 F/g at the rate of 0.1 A/g and could operate for up to 4000 cycles. Furthermore, in the capacitive deionization, AC-800 showed salt removal of 9.15 mg/g with a high absorption rate of 2.8 mg/g min and Ni(II) removal of 5.32 mg/g with a rate close to 1 mg/g.min. The results promote the potential application of CO2-activated AC for desalination as well as Ni-removal through capacitance deionization (CDI) technology.

Billroth-II Modified with Antiperistaltic Hinged Afferent Loop versus Roux-en-Y Reconstruction after Laparoscopic Distal Gastrectomy: A Propensity Score-Matched Analysis

Duy Long Vo,Quang Thong Dang,Quang Dat Tran,Viet Hai Nguyen,Le Minh Quoc Ho,Thuy Nguyen Doan,Anh Minh Tran,Vu Tuan Anh Nguyen,Lam Vuong Nguyen,Hoang Bac Nguyen 대한외과학회 2022 대한외과학회 학술대회 초록집 Vol.2022 No.11

A Laboratory-Scale Study of the Applicability of a Halophilic Sediment Bioelectrochemical System for in situ Reclamation of Water and Sediment in Brackish Aquaculture Ponds: Effects of Operational Conditions on Performance

( Hai The Pham ),( Phuong Ha Vu ),( Thuy Thu Thi Nguyen ),( Ha Viet Thi Bui ),( Huyen Thanh Thi Tran ),( Hanh My Tran ),( Huy Quang Nguyen ),( Byung Hong Kim ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.10

Sediment bioelectrochemical systems (SBESs) can be integrated into brackish aquaculture ponds for in-situ bioremediation of the pond water and sediment. Such an in-situ system offers advantages including reduced treatment cost, reusability and simple handling. In order to realize such an application potential of the SBES, in this laboratory-scale study we investigated the effect of several controllable and uncontrollable operational factors on the in-situ bioremediation performance of a tank model of a brackish aquaculture pond, into which a SBES was integrated, in comparison with a natural degradation control model. The performance was evaluated in terms of electricity generation by the SBES, Chemical oxygen demand (COD) removal and nitrogen removal of both the tank water and the tank sediment. Real-life conditions of the operational parameters were also experimented to understand the most close-to-practice responses of the system to their changes. Predictable effects of controllable parameters including external resistance and electrode spacing, similar to those reported previously for the BESs, were shown by the results but exceptions were observed. Accordingly, while increasing the electrode spacing reduced the current densities but generally improved COD and nitrogen removal, increasing the external resistance could result in decreased COD removal but also increased nitrogen removal and decreased current densities. However, maximum electricity generation and COD removal efficiency difference of the SBES (versus the control) could be reached with an external resistance of 100 Ω, not with the lowest one of 10 Ω. The effects of uncontrollable parameters such as ambient temperature, salinity and pH of the pond (tank) water were rather unpredictable. Temperatures higher than 35℃ seemed to have more accelaration effect on natural degradation than on bioelectrochemical processes. Changing salinity seriously changed the electricity generation but did not clearly affect the bioremediation performance of the SBES, although at 2.5% salinity the SBES displayed a significantly more efficient removal of nitrogen in the water, compared to the control. Variation of pH to practically extreme levels (5.5 and 8.8) led to increased electricity generations but poorer performances of the SBES (vs. the control) in removing COD and nitrogen. Altogether, the results suggest some distinct responses of the SBES under brackish conditions and imply that COD removal and nitrogen removal in the system are not completely linked to bioelectrochemical processes but electrochemically enriched bacteria can still perform nonbioelectrochemical COD and nitrogen removals more efficiently than natural ones. The results confirm the application potential of the SBES in brackish aquaculture bioremediation and help propose efficient practices to warrant the success of such application in real-life scenarios.

Adaptive hierarchical sliding mode control using an artificial neural network for a ballbot system with uncertainties

Hai Le Xuan,Quoc-Dong Hoang,Soon Geul Lee,Dat Pham Xuan,Hoang Tran Viet,Minh Pham Van,Hung Pham Van,Hung Pham Viet,PHAM DUC TUAN,Duc Anh Nguyen 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.2

Ballbots, which have been studied for over ten years, are under-actuated mobile robots that operate using the inverted pendulum paradigm. Controlling a ballbot poses a number of challenges, including maintaining the stable upright posture from the ground in all directions and making sure it follows the desired trajectory. External factors such as a minor change in contact surface properties or fabrication errors can affect the system's stabilization and transfer capabilities. In this study, an adaptive hierarchical sliding mode control algorithm based on an artificial neural network is developed to make the ballbot robust to external factors. The use of the proposed controller ensures system stability despite uncertainties including friction, accidental centrifugal forces and gravity that occur when the ballbot follows the reference trajectory. The system stability is guaranteed on the basis of Lyapunov theory. Control efficiency and robot stability under system uncertainties are demonstrated by numerical simulation.