Vietnam Academy of Science and Technology: Journals Online
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Linoleic acid isomerization ability of Lactobacillus spp. isolated from Vietnamese human intestinal origins
No full textConjugated linoleic acid (CLA) have been shown to exert numerous health benefits, including anti-carcinogenic, anti-atherogenic, anti-diabetic, antiobesity, cholesterol reducing, antioxidant, anti-microbial, immune system modulator and growth-stimulating properties. In human, CLA is produced from Linoleic acid (LA) by gut bacteria. In this study, nineteen Lactobacillus (Lac.) strains isolated from human feces were studied to determine their ability to metabolize LA. The bacteria were grown in the liquid form of anaerobic MRS medium supplemented with 0.5 mg/mL LA. The linoleate isomerase activity in bacteria grown on MRS medium was determined by Gas chromatograpy. The results indicated that 4 out of 19 strains, including strains Lac.02, Lac.05, Lac.14 and Lac.16 are capable of producing about 40-50 μg/mL CLA from LA. Among them, the highest ability to produce CLA from LA is Lac.02 strain. In the production of CLA from LA, enzymes involved in this metabolism in Lactobacillus act as catalysts of hydration/dehydration (CLA-HY), oxidation of hydroxy groups/reduction of oxo groups (CLA-DH), migration of carbon-carbon double bonds (CLA-DC), and saturation of carbon-carbon double bonds (CLA-ER). The cla-dh, cla-dc, cla-hy and cla-er genes that encode enzymes CLA-DH, CLA-DC, and CLA-ER had been found in all Lac.02, Lac.05, Lac.14 and Lac.16 strains. Gas chromatography traces indicated that these strains produced the same compounds, which was subsequently identified as cis-9, trans-11, and trans-10, cis-12 CLA. In the next study, we will optimize the conditions such as substrate concentrations, pH values, temperature and culture time of each strain to obtain the best rerults
Genetic variation of pharmacogenes
No full textPatient specific response against a particular drug could be affected by various factors, in which genetic factors are the most crucial contributor. The genetic variability in pharmacogenes might result in variable drug response of individuals, which in turn can lead to unexpected treatment outcomes or even adverse drug reactions. The pharmacogenes include of genes that encode for several proteins which divided into 3 main functional categories: drug metabolizing enzymes, drug transporters and receptor-drug targets. Genetic variants of genes coding for drug metabolizing enzymes phase I (CYP450), phase II (GSTs, UGT, TPMT) as well as drug transporters (ABC, SLCO) of numerous populations in global have been extensively studied. Among these, SNPs are the major contributor behind variants of pharmacogenes along with copy number variants. Furthermore, the clinical impact on drug response of common variants belonging to several important pharmacogenes has been well understood. On the other hand, information on the variant spectrum of genes encoding for receptor-drug targets as well as their physiological effects have remained limited. In recent years, along with computational methods, next generation sequencing technologies had been developed tremendously. These high throughput methods had greatly promoted the field of pharmacogenetic research through providing ability to detect novel and rare genetic variants. The data on genetic variants of pharmacogenes would be valuable for determining the responder and non-responder to medication during treatment. These are also significant basis which play a vital role in development of the field of optimizing drug dose for individuals and personalized medicine in the future
FLAVONOL GLYCOSIDES FROM THE LEAVES OF FISSISTIGMA PALLENS (FIN. & GAGN.) MERR.
No full textUsing combined chromatographic methods, five flavonol glycoside compounds including: kaempferol 3-rutinoside (1), rutin (2), kaempferol 3-O-α-L-rhamnopyranosyl-(1→6)-β-D-galactopyranoside (3), isorhamnetin 3-robinobioside (4), and kaempferol 3-O-α-L-rhamnopyranosyl-(1→2)-β-D-galactopyranoside (5) were isolated from the methanol extract of the leaves of Fissistigma pallens (Fin. Gagn.) Merr. Their chemical structures were determined using NMR spectra as well as in comparison with the reported data
Initial study on SARS-CoV-2 main protease inhibition mechanism of some potential drugs using molecular docking simulation
No full textThe infection by the new coronavirus SARS-CoV-2 (called as COVID-19 disease) is a worldwide emergency, however, there is no antiviral treatment or vaccine until now. The crystal structure of SARS-CoV-2 main protease has been made publicity in the Protein Data Bank recently. Many efforts have been conducted by scientists including the use of several commercial medicines, however, understanding at atomic level how these compounds prevent SARS-CoV-2 protease is still lacking. In this context docking protocol was employed to rapidly estimate the binding affinity and binding pose of six drugs on the main protease
ALKALOIDS AND CYCLOPEPTIDES FROM THE MARINE-DERIVED FUNGUS Aspergillus sp. M512
No full textIn the course of our screening program, the EtOAc extract of an Aspergillus sp. (strain M512) exhibited antimicrobial activities against three Gram Positive bacteria, and one yeast strain. This paper reported the isolation and structural elucidation of seven secondary metabolites including two alkaloids (1-2) and five cyclodipeptides (3-7) from culture broth of Aspergillus sp. M517. All isolated compounds were evaluated for their antimicrobial activity against a panel of clinically significant microorganisms. Except compound 1 and 2, with MIC values ranged from 32 to 128 μg/mL, five other compounds do not show inhibition activities against tested microorganisms
A STUDY ON COMBINATION OF BIOCHAR AND ACTIVATED SLUDGE FOR REMOVING AMMONIUM FROM LOW C/N RATIO WASTEWATER
No full textGrey domestic wastewater from septic tank contains high nitrogen content and low C/N ratio. Therefore, the aerobic biological treatment is often not effective for ammonium and nitrogen removal. The aim of this work was to study the performance of nitrogen removal and production of aerobic granular sludge using biochar produced from coffee husk pyrolyzed at 350oC as biocarrier. It was performed under the lab-scale SBR systems. Low C/N ratio domestic wastewater was used for this work. Coffee husk biochar (CFH 350) was added into the systems at different dosage. As a result, the biochar made from coffee husk pyrolyzed at low temperature promoted the adhesion of sludge onto biochar surface. The particles size of biochar played an important role for adsorption and adhesion capacity of activated sludge on biochar. The growth rate of bacterial sludge was accelerated and higher than control sample when biochar was used with biochar dose of 15 g/L. Though nitrification rate was improved as the bacterial sludge was accelerated, however, at initial stage, the removal efficiency of COD and total nitrogen was not as high as compare to traditional activated aerobic sludge system
VIBRATION OF 2D-FGSW TIMOSHENKO BEAMS UNDER A MOVING HARMONIC LOAD
No full textVibration of two-directional functionally graded sandwich (2D-FGSW) Timoshenko beams under a moving harmonic load is investigated. The beams consist of three layers, a homogeneous core and two functionally graded skin layers with the material properties continuously varying in both the thickness and length directions by power functions. A finite element formulation is derived and employed to compute the vibration characteristics of the beams. The obtained numerical result reveals that the material inhomogeneity and the layer thickness ratio play an important role on the natural frequencies and dynamic response of the beams. A parametric study is carried out to highlight the effects of the power-law indexes, the moving load speed and excitation frequency on the vibration characteristics of the beams. The influence of the beam aspect ratio on the vibration of the beams is also examined and discussed.
Removal of chromium from wastewater using paper waste sludge-derived hyrdrochar modified by naoh
No full textIn this work, paper waste sludge (PWS) collected from the primary settling tank of the paper wastewater treatment plant was utilized to generate hydrochar as a low-cost adsorbent for removal of Cr(VI) from aqueous solution. The characteristics of paper waste sludge hydrochar (PWSH) and the effects of adsorption conditions of Cr(VI) onto PWSH, including solution pH (3-9), contact time (5-240 min), initial Cr(VI) concentration (10-80 mg/L) and the adsorbent dose of 1 g/L at room temperature (25±2°C) were investigated. Adsorption isotherm and kinetics were also predicted in this work. The results indicate that the maximum adsorption capacity achieved 11.89 mg/g at 120 min of contact time, pH 3, and initial Cr(VI) concentration of 60 mg/L. The adsorption isotherm was reflected the best by the Langmuir model (R2 of 0.9968). Whereas, the adsorption kinetic also indicates that the pseudo-second-order model predicted the best for Cr(VI) adsorption process with a R2 of 0.9469. The mechanism of Cr(VI) adsorption process onto PWSH was chemical sorption through electrostatic interaction and ion exchange
Detection of DNA of Rickettsia and Orientia tsutsugamushi in rodents and ectoparasites in Ha Giang province
No full textRickettsial fever is one of a zoonotic disease which is caused by bacteria genus Rickettsia. The ectoparasites such as ticks, mites, fleas, lice... were demonstrated as the main transmited vectors through host reservoirs are rodents and small animals including mice, squirrels, mink... In this study, the rodents and ectoparasites species were identified. The molecular detection of Rickettsia was also performed. In 2018, 83 rats were trapped in 2 villages Thanh Duc and Phu Linh, Vi Xuyen district, Ha Giang province, in which 48.2% mice were found as house mice Rattus flavipectus, 21.7% was forest mice R. rattus, 12% was R. fulvescens, 8.4% was R. nitidus, the remaining rates were R. bowersi, Mus. pahari, Leopoldamys sabanus, Mus musculus and R. niviventer, accounting for 1.2% - 3.6%. The ectoparasites survey found 5 chigger mite species including Leptotrombidium (Leptotrombidium) deliense, Ascoschoengastia (Laurentella) indica, Garhliepia (Walchia) rustica, Lorilutum oreophilum and Shunsenia sp as well as 3 gamasid mite species such as Laelaps (Echidninus) sedlaceki, Laelaps (Laelaps) nuttali and Lenstivalius klossi bispiniformis. The result indicated that 19.3% and 10.8% mice were positive with Ricketsia spotted fever group (SFG) and Rickettsia typhi, respectively by real-time PCR. The nested PCR result showed that 19.4% R. flavipectus mice and 10% L. (L.) deliense chigger mites were positive with Orientia tsutsugamushi.
Integrated coastal zone management in Vietnam - status and emerging problems
No full textICZM is a correct orientation and feasible towards sustainable development. Due to socio- economic circumstances, there are certain differences in the application of ICZM model in different countries, especially in the developed and developing countries. Although there were successful models in some countries or some places, many activities of ICZM do not achieve high efficiency and do not become a self-reliant process. ICZM in Vietnam has achieved certain results. Over the past 20 years, research projects, pilot projects and implementation projects have significantly contributed to ICZM in terms of improving knowledge, increasing awareness and accumulating experience. Vietnam has a favorable organizational mechanism for ICZM, which is considered as an indispensable orientation for sustainable development. ICZM in Vietnam has a solid legal basis. However, ICZM in Vietnam is not very sustainable, facing great opportunities and challenges. ICM is facing issues that need to be addressed such as theoretical basis, organizational structure, capacity, methodology and sustainable financial resources,... ICZM can only succeed on the basis of mastering the theoretical basis and having creative application in practical conditions of Vietnam