bluuebunny/crossref_metadata_2025 huggingface dataset:
Isolation, enrichment of a halophilic yeast Candida sp. YH and its treatability study of saline wastewater
Authors: Chí Trần Minh , Minh Nghiêm Ngọc
Published: April 2018

A strain of halophilic yeast was isolated, enriched and adapted to an increasing salinity started from 5, 10 to 15 g/l NaCl to get it adapted gradually to high saline environment. Then the yeast biomass was developped in batch experiment, with each batch lasted 32 hours each, at further increased salinity to 20, 25 and 30 g/l NaCl with influent COD 5000 mg/l at pH 3.5, temperature 30oC. At salinity 20 g/l NaCl, COD removal efficiency reached over 90% from beginning and reached over 96% after 6 batches with effluent COD 203 mg/l. When the salinity increased to 25 g/l, COD removal efficiency varied within 89% to 90% in first 4 batches and reached 95% after 8 batches with effluent COD 250 mg/l. At salinity 30 g/l NaCl, COD removal efficiency decreased notably, reached less than 90% during first 5 batches and then inceased gradually, reached 93.6% only after 9 batches with effluent COD 320 mg/l. Salinity was the main factor influencing the ion equilibrium inside the yeast cells leading to decrease in substrate degradation and rate of cell. Inceased salt concentration also lead to longer adaptation time of the cells. The cell morphology of YH strain was observed by Scanning Electron Microscopy (SEM). The cells of this yeast strain has lemon-like shape, with 1.3–1.78 in width; and 2.00–2.69 µm in length. Based on the morphological characteristics and the phylogenetic analysis by alignment of ITS1-5.8S rRNA-ITS2 sequences, high homology up to 92% with Candida sp. YS W113A (AM410670)) indicated this strain as, namely, Candida sp. YH.
Optimization of biosurfactant production for enhanced crude-oil degradation by a Candida tropicalis 1214-BK14 isolated from white tiger oilfiel - Vung Tau, Vietnam
Authors: Hoa Kiều Thị Quỳnh , Yên Nguyễn Thị , Yến Đặng Thị
Published: April 2018

Biosurfactants are amphiphilic molecules with effective surface-active and biological properties applicable to replace synthetic surfactant in petroleum industry. Interest in microbial surfactants has been steadily increasing in recent years, as they have numerous advantages compared to chemical surfactants including a lower toxicity, better environmental compatibility and effective properties at extreme temperature, pH levels and salinity. A crude oil-degrading yeast strain (C. 1214-BK14) was selected among the isolated strains as a potential biosurfactant-producer from producing oil wells at White Tiger oilfield because of its ability to produce biosurfactant using crude oil as a sole carbon source. An emulsification index (E24%) of 57% was obtained initially by Candida tropicalis 1214-BK14 in previous study. Therefore, the optimization of biosurfactant production of this strain for enhanced crude oil degradation was carried out based on central composite design and analyzed using response surface methodology (RSM). The biosurfactant production process was investigated as function of three independent variables: crude oil (2.5-5 % w/v), (NH4)2SO4 (0.35-0.45% w/v), and solution pH (5-8). RSM analysis showed that the optimum condition for the biosurfactant production by C. tropicalis 1214-BK14 were 6.1, 3.97% (w/v) and 0.37% (w/v) for pH, concentration of carbon (crude oil) and nitrogen substrate ((NH4)2SO4), respectively, with the emulsification index measured in the conditions was 80.2%. The total crude oil and C10-C43 alkanes degradation efficiency by this strain estimated using GC/MS were 89.8% and 80.47-98.58%, respectively. These results revealed that the strain Candida tropicalis 1214-BK14 exhibited a tremendous potential for contaminated-crude oil degradation and microbial enhanced oil recovery (MEOR).
11β-hydroxylase deficiency disorders
Authors: Mai Nguyễn Thị Phương , Hải Nông Văn , Hoàng Nguyễn Huy
Published: April 2018

Congenital adrenal hyperplasia (CAH) is a family of autosomal recessive disorders which is characterized by a deficiency of one of the enzymes involved in the synthesis of cortisol from cholesterol by the adrenal cortex. 90% CAH patients respond to 21-hydroxylase deficiency. Less causes include deficiencies of 11β-hydroxylase (11-OH), 17- hydroxylase (17-OH), 3β- hydroxysteroid dehydrogenase (3β- HSD), 20/22 Desmolase etc.. Because of the blocked enzymatic steps, cortisol precursors usually presents with signs of androgen excess which are secreted and cause in masculinization of female external genital, hyponatremia, hyperkalemia and hypovolemia in the classic form due to 21-hydroxylase deficiency. By the early 1950s, it was recognized that in some CAH patients with hypertension develops. This symptom responds to glucorticoid replacement. Most of these patients have an 11β-hydroxylase deficiency. CAH cases arise from 11β-hydroxylase impaired is the second most common form. Mutations in the CYP11B1 gene are the cause of 11β-hydroxylase deficiency. The incident of 11β-hydroxylase deficiency is about 5% to 8% of cases with CAH, in approximately 1/100,000 live birth. Mutations have been detected from different ethnic backgrounds with the highest incidence in group of Morrocan Jews. This article reviews function of enzyme 11β-hydroxylase in cortisol synthesis of andrenal cortex, structure of CYP11B1 gene, diagnosis and treatment of 11β-hydroxylase deficiency and summarised of researching in Wordwild and in Vietnam. Genetic characterization of CYP11B1 genotype has improved our understanding of the phenotype differences in patients. This could be serve as a the basis for genetic counseling and prenatal diagnosis in the future.
Staphylococcal enterotoxin B (SEB) toxin of Staphylococcus aureus and the detection methods
Authors: Thu Nguyễn Thị Hoài , Minh Nghiêm Ngọc
Published: April 2018

Staphylococcal enterotoxins (SEs) secreted by Staphylococcus aureus is one of the principal causes of food poisoning. The SEs are superantigens; they are highly stable, resisting most proteolytic enzymes and thus keeping activity in the gastrointestinal tract after being ingestion. In particular, heat-stable enterotoxin is one of the most important property related to food safety. They are not degraded at 100°C for 30 minutes, even at 121oC for 28 minutes, the SEs retain biological activity. Heat resistance of SEs in foods is higher than in the culture medium. Staphylococcus aureus (S. aureus) produces more than 20 different types of enterotoxins, including SEA to SEE, SEG to SER and SEU. Among these, Staphylococcal enterotoxin B (SEB) is a powerful toxin, heat-stable, water-soluble and is a common cause of food poisoning. Moreover, SEB is one of the harmful or hazardous agents used as biological weapons in bioterrorism or biological warfare. Therefore, determining presence of SEB toxin in food is extremely important. In this review, we introduce the most basic features about S. aureus; about SEB toxin and conventional methods for SEB diagnosis, detection. Especially, we focus on rapid detection strip based on an immunochromatography; this technique is an highly sensitive, rapid, easy for use and storage.
The association between gsto1 polymorphisms and arsenic methylation of prenatal arsenic exposed infants
Authors: Tạ Thị Bình Tạ Thị Bình Tạ Thị Bình , Thảo Trần Phương , Hải Nguyễn Khắc , Hoàng Nguyễn Huy
Published: April 2018

The trace element arsenic naturally presents in the environment. Arsenic is the essential factor to the human body at low level, however it causes environmental pollution and have negative effects to health at high level. Recently, arsenic contamination as well as its effects on public health, especially infants and children is increasingly becoming important and serious issues in worldwide. Glutathione S-transferase omega-1 (GSTO1) is a phase II enzymatic detoxification of xenobiotics in variety of animals including humans; to catalyze the arsenic methylation. The difference of urinary arsenic component in each individual may relate to the genetic polymorphism. To evaluate the variations of single nucleotide polymorphisms of GSTO1, PCR-RFLP technology was ultilized. Single nucleotide polymorphisms (SNPs) genotype of 150 cohort blood samples at GSTO1 Thr->Asn (rs15032), GSTO1 Ala->Val (rs11509439) and GSTO1 Ala->Asp (rs4925) were detected. The association between GSTO1 polymorphisms and prenatal arsenic exposure was evaluated by statistical analysis such as SPSS software version 20, t-test and oneway ANOVA. The results showed that GSTO1 Ala->Asp (rs4925) was statistically associated with MMA/iAs (p = 0.041). Differences between ratio of MMA/iAs and genotypes were checked by Tukey-Kramer method, along with oneway ANOVA showed that Individuals taking the AA genotype had higher MMA/ iAs ratio than individuals carrying the CC genotype, with a statistically significant association (p = 0.044), also clearly higher than the individuals carrying AC genotype, significant at p = 0.046. Therefore, it is possible that individuals carrying the AA genotype in the polymorphism have higher arsenic excretion than individuals with CC and AC genotypes
Identification of PSORS1C3 variants in Vietnamese patients with psoriasis disease
Authors: Liên Nguyễn Thị Kim , Việt Lê Bắc , Kỳ Lê Đình , Biển Nguyễn Văn , Bền Nguyễn Văn , Hoàng Nguyễn Huy
Published: April 2018

Psoriasis is an immune disorder disease which has genetic cause. It is benign disease, and usually lies in dormant status in the body until the patient triggered by a variety of factors such as environment, lifestyle and diet. The disease has an effect on the aesthetic, many serious complications and affects a large number of the world population. Until now, there are no specific method of cure only treatment of disease stabilization, avoidance complications and improvement quality of life for patients. Genetic studies of psoriasis have been identified 13 loci associated to susceptibility of disease. Among them, the PSORS1 region on chromosome 6p21.3 was identified as highest relevant to susceptibility of disease. In this study, blood samples of the Vietnamese patients with psoriasis disease were collected and investigated. Exons in PSORS1C3 gene, one gene in locus PSORS1, in psoriasis patients were amplified by using specific primer pairs. The single nucleotide polymorphisms (SNP) of PSORS1C3 gene were determined by sequencing and comparing with the reference sequence in Ensembl. We found out 14 SNPs including of 6 SNPs rs3868542, rs11507945, rs11507946, rs3871247, rs11507947, rs3871246 on exon 1; 2 SNPs rs3099189, rs3132517 on exon 2; 6 SNPs rs887467, rs887468, rs1061503, rs2269711, rs11507948 and rs11507949 on exon 3 of PSORS1C3 gene in Vietnamese patients with psorisis disease. The results showed that there was one SNP rs3871246 have significant association to susceptibility of disease with p
Study on some properties of the hybrid cell B4D10C9 producing the anti B monoclonal antibody which was agglutinated the b antigens on the surface of red blood cells
Authors: Trung Nguyễn Thị , Hải Trương Nam
Published: April 2018

The B4D10C9 hybridoma cell line producing the monoclonal antibody which was specifically agglutinated red blood cells B group, belongs to the IgM class and kappa light chains that have been created in our previous study. This study presents some biological charateristics of B4D10C9 such as the capability of growth, anti B monoclonal antibody producing, the stability of growth and cell line and antibody secreting of this cell line. The hybridoma cells grew well in the DMEM medium added with fetal bovine serum (FBS) at the final concentration of 1% or 10%. However, the maximum density of cells reached 9,9 x 105 cells per ml after 50 hours post incubation only when it was cultured in the medium containing 10% of FBS. The maximum antibody titers in the supernatant that collected after 150 hours of culture reached 1/512. In contrast to that, the maximum density of cells only reached 3,4 x 105 cells/ml after 72 hours post incubation when was cultured in DMEM medium containing 1% FBS. The maximum antibody titer was 1/64 after 50 hours post incubation. These cells were cultured through 3 different generations and the ability of antibody production in each generation was evaluated. As a result, this cell line had continuous growth stability and antibody secretion through 3 generations. The quantity of monoclonal antibody obtained from the supenantant of the culture medium at 150 hours of incubation was about 100 micrograms per ml. Thus, the growth of the cell line B4D10C9 and its ability of secretion of anti B monoclonal antibody were better when was cultured in the DMEM medium containing 10% fetal bovine serum. Preservation, storage and recovery does not affect to the growth and antibody producing of this cell line.
The antioxidant and in vitro hepatoprotective activities of some chemical fractions from Phyllanthus reticulates Poir. plant
Authors: Nguyễn Thị Cúc Nguyễn Thị Cúc Nguyễn Thị Cúc , Trâm Nguyễn Công Thùy , Phương Đỗ Thị , Phương Vũ Thị Thu , Nga Nguyễn Thị , Truan Gilles , Thảo Đỗ Thị
Published: April 2018

The Phen-den plant (Phyllanthus reticulatus Poir.) has been widely used in Vietnamese tradional medicine for detoxification, antiseptic, diuretic, anti-inflammation treatments…However, there is still lack of studies on this plant’s antioxidant and in vitro hepatoprotective activities in Vietnam. Recently, the use of liver enzymes such as CYP450 reductase (CPR) in determining the in vitro hepatoprotective activities of potential compounds, which are originated from herbal plants, is increasing based on its high efficiency and short duration. Furthermore, the other in vitro assays such as DPPH (2,2-diphenyl-1-picryl-hydrazylhydrate) scavenging, inhibition of lipid peroxidation (MDA) are popularly employed for determination of antioxidant activities. With the success in isolation of CPR from Saccharomyces cerevisiae WR1A2 strain (5 litres/batch), we set up the assay for screening potential samples which could be able to induce CPR for in vitro hepatoprotective action. The obtained results from this CPR screening assay showed the similarity to those of other popular antioxidant assays such as DPPH or MDA. The resulted from our assay showed that the water extract of Phen-den plant had the highest ability to induce CPR supporting the hepatoprotective activities. Also, the water extract, EtOAc extract and total extract exhibited very strong antioxidant activities through DPPH scavenging assay and inhibition of lipid peroxidation with the SC50 values ranging at 13.84 µg/ml, 37.64 µg/ml, 28.31 µg/ml and the IC50 values ranging at 5.99 µg/ml, 4.77 µg/ml, 27.58 µg/ml, respectively.
1Institute of Biotechnology, Vietnam Academy of Science and Technology
Authors: Dũng Nguyễn Tiến , Anh Đỗ Thị Vân , Phương Nguyễn Thị Minh , Huyền Bùi Thị , Minh Phạm Đình , Chí Đỗ Hữu , Liên Nguyễn Thị Phương , Chi Phan Văn , Thảo Lê Thị Bích
Published: April 2018

Wasp venoms are complex mixtures of various types of compounds, of which proteins and peptides are major components. Beside its toxicity, wasp venom is potential for treatment of diseases. Characterization of venom proteins and peptides is the first and most important step toward its applications in medicine. Vietnam possesses many valuable materials, of which venoms could be used in medicine. In the present work, we aim to identify proteins and peptides in the venom of Vespa velutina (V. velutina), a species of social wasp indigenous to Southeast Asia including Vietnam using proteomic techniques. The venom isolated from V. velutina by manual extraction was digested with trypsin via the FASP (Filter Aided Sample Preparation) method and analyzed with liquid chromatography tandem - mass spectrometry (LC-MS/MS). The following protein identification, protein validation, and peptide de novo sequencing were carried out using the Peaks software. In total, we detected 36 proteins from V. velutina venom and many of them had been reported as venom-specific proteins. According to Gene Ontology Annotation (GOA), V. velutina venom proteins were functionally classified into five categories: binding proteins (53%), catalytic proteins (33%), structural proteins (8%), antioxidants (4%), and proteins with other functions (2%). In addition, 81 peptides were detected in the venom of V. velutina by de novo sequencing, of which 34 peptides (42%) are potential venom peptides. We introduced for the first time the collection of proteins and peptides from V. velutina venom, providing the basis for its further application in medicine.
An assessment of the domestication impact on levels of genetic diversity in a synthetic line of giant freshwater prawn (Macrobrachium rosenbergii) for a stock improvement program in Vietnam
Authors: Thành Nguyễn Minh , Mather Peter
Published: April 2018

Six microsatellites were used to characterize genetic diversity in three purebred giant freshwater prawn (Macrobrachium rosenbergii) strains that originated from a diallel cross among two wild Vietnamese strain (Dong Nai and Mekong) and a third domesticated Hawaiian strain. All three purebred strains showed relatively high levels of genetic diversity with average number of alleles per locus (A) ranging from 13 to 15. Average observed (Ho) and expected (He) heterozygosities across loci were 0.84 to 0.89 and 0.87 to 0.89, respectively. Microsatellite data from the three purebred strains were pooled together as a basis for estimating the levels of genetic diversity in an synthetic hatchery population and this compared with data for genetic diversity in the three wild populations combined. No significant differences were observed in the relative levels of genetic diversity between the two combined populations. Average A, Ho, and He for the experimental vs. wild reference populations were 24.33 vs. 24.33, 0.87 vs. 0.90, and 0.94 vs. 0.95, respectively. Therefore, an experimental population formed by combining the genetic resources from three purebred strains showed non-significant loss of genetic diversity as a consequence of domestication process. Thus such a synthetic line can provide an important genetically diverse resource for the planned development of GFP culture in Vietnam.
The effect of biotic and abiotic elicitors on biomass and saponin production of secondary root cultivated in shake flasks Panax vietnamensis adventitious root
Authors: Linh Nguyễn Thị Nhật , Tùng Hoàng Thanh , Lộc Nguyễn Hoàng , Nhựt Dương Tấn
Published: April 2018

Panax vietnamensis Ha et Grushv. is an endemic ginseng of Vietnam which has highly nutraceutical, medicinal and comercial values. Many its special saponins provide resistance to stress, disease and exhaustion. In this study, the biotic elicitors (yeast extract and chitosan) at concentrations from 50 – 200 mg/l and abiotic elicitors (jasmonic acid, abscisic acid and salicylic acid) at concentrations from 50 – 200 µl/l were used to evaluate the possibility of increasing secondary root’s biomass and saponin in Panax vietnamensis adventitious root cultures. This cultures were maintained on Innova 2100 shaker shaker plantform at a speed of 100 rpm, and its modified MS medium (NH4+/NO3-: 7.19/18.5 mM/mM) were supplemented with 7 mg/l IBA, 0.5 mg/l BA and 3% sucrose. Results after 56 days of cultured showed that most elicitors significantly reduced dry biomass of secondary roots as compared to control (exception the addition of 50 – 100 mg/l yeast extract or 50 µl/l salicylic acid). However, all elicitors increased saponin-accumulation, and abiotic elicitor is more effective saponin-accumulation than those biotic elicitors. Jasmonic acid obviously gave the best results; with total amount of 3 saponins at 150 µl/l, Rg1 at 100 µl/l, Rb1 at 50 µl/l and MR2 at 200 µl/l and Rg1 (3.22%), significantly higher than other concentration of elicitor. However, for accumulating saponins and developing secondary root, 150 mg/l YE is the most real effective in all elicitors (0.88 mg).
In vitro micropropagation of Anthurium andraeanum through thin cell layer culture
Authors: Lan Trần Thị Ngọc , Anh Trần Thị Hoàn
Published: April 2018

Anthurium is a kind of major cut flower species and economically important genera in the family Araceae. A regeneration system of Anthurium andreanum from callus culture is studied along with improving propagation process. Optimal medium for callus formation from the longitudinal thin cell layer leaf culture was ½ MS (Murashige, Skoog, 1962) supplemented with 30 g/l sucrose, 1 g/l casein hydrolysate (CH), 8 g/l agar, 1.5 mg/1 BA and 0.2 mg/1 2,4-D (the induction callus rate of 77.33%). Calli multiplied with 21.45-fold fresh mass increase when they were subcultured once 60 days on the ½ MS supplemented with 1 g/l CH, 30 g/l sucrose, 1,5 mg/l BA and 8 g/l agar. The highest ratio of shoot induced from callus culture was also on this medium (18.54 shoots per explants). The medium ½ MS supplemented with 20 g/l sucrose, 1 g/l AC, 8 g/l agar and without plant growth regulators is the most suitable one for root formation of these multiple-shoots. The highest survival rate is observed with substrate mixture of fern moss and rice husk ash in the ratio of 1:1 (gave the best regeneration rate of 100% in the ex vitro culture) and no morphological variations were observed in these plantlets after about thirty days,acclimatized in the greenhouse. Histological observation showed that these calli contained embryogenic cells with their fast growth.It could be an alternative tool for propagation and preservation of Anthurium andreanum, a valuable cultivar.
Evaluation of the genetic diversity of maize lines by microsatellite markers
Authors: Thu Nguyễn Thị , Tuấn Ngô Anh , Ngọc Vũ Thị , Linh Ngô Thị Thùy , Minh Vương Huy , Thủy Lê Thị Bích
Published: April 2018

Recently, quantitative trait loci (QTLs) have been identified for resistance to ear rot. Techniques to ensure accurate phenotyping of Fusarium ear rot have been developed and validated. DNA marker technologies have matured and become economically feasible for some DNA marker assisted selection programs. Research and breeding efforts aimed at improving resistance to the Fusarium ear rot, identifying sources of resistance and characterizing the inheritance of ear rot. Resistance to Fusarium ear rot is under genetic control, but no complete resistance has been identified in maize. Once suitable sources of resistance have been identified, inheritance of resistance should be considered before selecting a breeding strategy, so evaluation of genetic diversity of maize lines is necessary for cross combination. Genetic diversity analysis of 71 inbred lines by 10 SSR markers detected 10 loci with a total of 42 alleles and average of 4.2 alleles per locus, the number of alleles on a locus varied from 3 to 6. Polymorphic Information Content (PIC) varied from 0.5783 to 0.8088, average of 0.6981. The Umc1196 marker revealed the highest polymorphism, the Umc1249 marker gave the lowest polymorphism. 71 inbred lines were divided into seven main groups. The genetic similarity among 71 lines ranged from 0.333 to 0.976. H3062 line maize had the lowest genetic similarity coefficient (0.333). The lowest genetic similarity coefficient was recorded in H3062 and H84 (0.333). Two lines H161 and KC161 had the highest genetic similarity coefficient (0.976). Almost maize lines had high genetic similarity coefficient showing the same similarity in genetic relationship.
Construction an expression vector and Agrobacterium tumefaciens strain carrying ZmbZIP72 gene isolated from maize
Authors: Hằng Phạm Thị , Hạnh Hà Hồng , Linh Nguyễn Thùy , Hiền Lê Thị Thu , Hải Nông Văn , Huệ Huỳnh Thị Thu
Published: April 2018

In plants, members of bZIP transcription factors are involved in various biological processes such as organ and tissue differentiation or vascular development. Moreover, the basic leucine zipper (bZIP) is one of the largest transcription factor families which play an important role in environmental stress responses. However, few bZIP genes are related to abiotic stress responses. Some studies have found that transgenic plants overexpressing the bZIP genes enhanced tolerance to abiotic stresses. Several of stress-related genes in maize have been identified and characterized. A ZmbZIP72 gene belonged to A group could be strongly induced by ABA and abiotic stresses. Some previous studies have shown that overexpression of the ZmbZIP72 gene resulted in improved drought and salt tolerance of a transgenic Arabidopsis. In this work, the ZmbZIP72 gene from drought-treated maize was isolated and sequenced with 894 bp in full-length of the coding region. Nucleotide comparison of the ZmbZIP72 gene and a GenBank sequence (accession number HQ328839) revealed that two changes were found at positions 486 (A to C) and 493 (C to T), respectively. Changes in predicted amino acid sequence were at positions 102 (Lys>Asp) and 105 (Pro>Ser). The newly isolated ZmbZIP72 gene was ligated with RD29A promoter and 35S terminator to create a RD29::ZmbZIP72::35S cassette in pRTL2 vector. Afterwards, this cassette was constructed into pCAMBIA1301 and the new recombinant pCAMBIA1301 vector carrying ZmbZIP72 construct has transformed into A. tumefaciens strain EHA105 which is material for plant transformation.
Cloning and constructing transformation vector carrying IbOr from the sweetpotato (Impomea batatas L.) involved in accumulation of carotenoids
Authors: Hương Hồ Thị , Ninh Nguyễn Thùy , Thành Nguyễn Đức
Published: April 2018

The Orange gene (Or gene) is known as a gene encoding the protein containing a cysteine-rich Zinc finger domain. The Or protein is an important component of the structure that involes in accumulation of carotenoids and enhancing the resistant ability of plant to enviromental stresses. In an attempt to improve the nutritional quality and resistance to adverse environmental conditions of maize, in this article, we present the results on cloning IbOr gene from the sweetpotato cultivar Hoang Long and constructing transformation vectors carrying cloned IbOr gene under control of Ubiquitin (Ubi) or Globulin 1 (Glo1) promoter. The cloned IbOr gene was 942 bp in size and had similarity level of 100% comparing to the IbOr gene that was deposited in GenBank with Accession number HQ828087.1. The IbOr gene from sweedpotato Hoang Long was registered in GenBank under Accession number KX792094.1. The deduced protein consisted of 313 amino acids having Zin finger domain of DnaJ and HSP40 proteins. We have also constructed two transformation vectors pCambia2300/Ubiquitin/IbOr/Nos and pCambia2300/Glo1/IbOr/Nos. These vectors were transformed successfully into Agrobacterium tumefaciens strain C58. The presence of the target gene (IbOr) and promoter (Ubi or Glo1) in the A. tumefaciens strains were confirmed by colony-PCR amplification with respective specific primer pairs and digested by suitable restriction enzymes. These vectors will provide important materials for further gene transfer research for the expression of IbOr gene and production of transgenic maize with ability to accumulate high carotenoids.
Study on antifungal activity of silver/bentonite nanomaterials on soybean phytopathogenic fungi
Authors: Châu Nguyễn Hoài , Thúy Nguyễn Thị , Hiền Đào Trọng , Mai Hoàng Thị , Quang Nguyễn Văn , Long Phạm Hoàng , Ngọc Nguyễn Thị Bích , Thêu Trần Thị Phương
Published: April 2018

In the present study, silver nanoparticles were synthesized by chemical reduction method route into the lamellar space of bentonite (Ag/CTS/Bentonite). Silver nitrate (AgNO3) was taken as a metal precursor, sodium borohydride (NaBH4) as a reducing agent, reduction of Ag+ ions and the subsequent formation of Ag nanoparticles, chitosan as a natural polymeric stabilizer and was sticked silver nanoparticles to the surface of bentonite particles, respectively. Manipulating the size and shape of Ag/CTS/Bentonite nanomaterial was characterized using transmission electron microscopy (TEM), spherical silver nanoparticles, as depicted by TEM, were found to have a wide particle size distribution from 5 nm to 90 nm. Meanwhile, the X-Ray flourescence (XRF) spectrum indicated the presence of silver on bentonite particles. Antifungal activity of the synthesized Ag/CTS/Bentonite nanomaterial was investigated against crop pathogenic fungi (Fusarium oxysporium (F. oxysporium) and Rhizoctonia solani (R. solani)) isolated from infected soybean plant in Bac Ninh province by the Plant Protection Research Institute. The assessment of fungicidal activity of the Ag/CTS/Bentonite nanomaterial showed that this product exhibited strong antifungal activity towards soybean pathogenic fungi. At highest nanosilver concentration of the Ag/CTS/Bentonite nanocomposite (400 ppm) sclerotial germination of F. oxysporum was almost inhibited, after 7 days the inhibition effect on sclerotial germination attained 66.70%. For the case of R. solani, after 2 days at 400 ppm silver nanoparticles concentration the inhibition effect on sclerotial germination attained 92.82%. The obtained results suggested that the synthesized Ag/CTS/Bentonite nanomaterial acts as an effective antifungal agent. Thus, it could be used in developing novel antifungal agents for potential applications in agriculture.
Promoters of the dhs-21 gene encoding dicarbonyl/l-xylulose reductase in Caenorhabditis elegans
Authors: Sơn Lê Thọ , Ahnn Joohong , Cho Jeong Hoon , Hoàng Nguyễn Huy
Published: April 2018

Dicarbonyl/L-xylulose (DCXR) was identified as a dehydrogenase. This type of enzyme was presented in

various forms of lives including bacteria, fungi, plants and animals. Generally, it converts L-xylulose to xylitol in the presence of either cofactor NADH or NADPH in vitro. Previous studies reported the biochemistry properties and crystal structure but largely uncovered biological roles of DCXRs. It was impossible to dissect the functions in mice or human cells that had many DCXR homologs in their genomes. Interestingly, the wild-type Caenorhabditis elegans, a well-known model organism in biological research, has only nuclear genomic dhs-21 that encodes a unique homologous DCXR. Thus Ce.dhs-21 and the host C. elegans were relevant for investigation of the physiologically-vital functions of the DCXR. This research aimed to the expression of dhs-21 in vivo. We defined three promoters , manipulated three relative reporter-constructs that conjugated the dhs-21 gene and Green Flouresent Protein (known as GFP) one. The construct vectors were transferred into wild-type C. elegans N2 and as well as the hermaphroditic loss of function dhs-21(jh129) by microinjection. In the results, we found that the expression pattern of dhs-21 under the only p2-promoter construct was stable and similar to immunogold Electric Microscopy (EM) images. The dhs-21 gene was expressed in both sexes of at all larval stages till the deaths of worms. DHS-21 was expressed in the cytosol of the intestinal, gonad sheath and uterous seam cell (utse).
Investigation of methods for extraction of bacterial DNA metagenome from goat rumen
Authors: Giang Lê Ngọc , Ly Lưu Hàn , Phương Nguyễn Mai , Lâm Lê Tùng , Huyền Đỗ Thị , Nguyệt Phùng Thu , Hải Trương Nam
Published: April 2018

Microorganisms, particularly bacteria, in the ruminant's rumen are valuable genetic resources that many scientists interested in. In recent years, the application of next-generation sequencing technologies allows direct decoding an extracted DNA metagenome in each ecological community without culture, increasing the efficiency of exploiting interested genes. Notably, the quantity and quality of extracted DNA play an important role in getting a reliable metagenome database. In this study, DNA metagenome from goat rumen fluid was extracted by five different methods RBB (repeated bead beating plus column), RBBC (repeated bead beating), PSP1, PSP2 (PSP®Spin Stool DNA Kit, protocol 1, 2, Germany) và QIA (QIAamp® DNA Stool Mini Kit, Germany). The results showed that DNA metagenome obtained by all methods had A260/280 greater than 1.8. DNA extracted by the RBB method had high DNA concentration but low A260/230 values (less than 1.4) and still contained Taq polymerase inhibitor. After purifying by QIA column, A260/230 values of RBB-extracted DNA significantly increased up to 2.0 and Taq polymerase inhibitor in samples were removed. However, the concentrations decreased by 57% that nearly equivalent to concentration of DNA metagenome obtained by QIA. The method using PSP®Spin Stool DNA kit produced the highest DNA concentrations (from 149.7 to 195.5 ng/µl) with A260/280 ratios of 1.9 and A260/230 ratios of 1.8 to 1.9. Morever, this method was able to remove polymerase inhibitor and be performed on short time. Therefore, the PSP®Spin Stool DNA kit is a suitable method for DNA metagenome extraction of bacteria from goat rumen. DNA obtained by this method fulfilled all criteria about quality and concentration for sequencing by next-generation sequencing Illumina.
A METHOD OF BEARING FAULT DIAGNOSIS USING SINGULAR SPECTRUM ANALYSIS, SPARSE FILTERING AND ANFIS
Authors: Nguyen Dung Sy , Nguyen Van Hiep
Published: April 2018

Bearing is an important machine detail participating in almost mechanical systems. Estimating online its operating condition to exploit actively the systems, therefore, is one of the most urgent requirements. This paper presents an online bearing damage identifying method named ASBDIM based on ANFIS (Adaptive Neuro-Fuzzy Inference System), Singular Spectrum Analysis (SSA) and sparse filtering. This is an online estimating process operated via two phases, offline and online one. In the offline period, by using SSA and sparse filtering, a database signed Off_DaB is built whose inputs are features extracted from the measured data stream typed big data, while its outputs are values encoding the surveyed bearing damage statuses. The ANFIS is then employed to identify the dynamic response of the mechanical system corresponding to the bearing damage statuses reflected by the Off_DaB. In the online period, first, at each estimating time, another database called On_DaB is established using the way similar to the one used for building the Off_DaB. The On_DaB participates as inputs of the ANFIS to generate its outputs which are then compared with the corresponding encoded outputs to specify bearing real status at this time. Survey results based on different data sources showed the effectiveness of the proposed method.
B-Codes and their relationship with alternative codes
Authors: Ngo Hien Thi
Published: April 2018

Codes of bounded words (b-codes,  <>-codes), an extension of the notion of ordinary codes, have been first introduced and considered by P. T. Huy et al. in 2009. In this note, we consider some new subclasses of b-codes. In particular, characteristic properties of such codes are established. Also, relationship between b-codes, alternative codes and their subclasses are considered.
GMM FOR EMOTION RECOGNITION OF VIETNAMESE
Authors: Thủy Đào Thị Lệ , Loan Trinh Van , Quang Nguyen Hong
Published: April 2018

This paper presents the results of GMM-based recognition for four basic emotions of Vietnamese such as neutral, sadness, anger and happiness. The characteristic parameters of these emotions are extracted from speech signals and divided into different parameter sets for experiments. The experiments are carried out according to speaker-dependent or speaker-independent and content-dependent or content-independent recognitions. The results showed that the recognition scores are rather high with the case for which there is a full combination of parameters as MFCC and its first and second derivatives, fundamental frequency, energy, formants and its correspondent bandwidths, spectral characteristics and F0 variants. In average, the speaker-dependent and content-dependent recognition scrore is 89.21%. Next, the average score is 82.27% for the speaker-dependent and content-independent recognition. For the speaker-independent and content-dependent recognition, the average score is 70.35%. The average score is 66.99% for speaker-independent and content-independent recognition. Information on F0 has significantly increased the score of recognition
NGHIÊN CỨU MỘT SỐ YẾU TỐ ẢNH HƯỞNG ĐẾN SỰ HÌNH THÀNH HOA IN VITRO Ở CÂY TORENIA (TORENIA FOURNIERI L.)
Authors: Nhựt Dương Tấn
Published: April 2018

Sự chuyển đổi từ giai đoạn sinh dưỡng sang sinh sản (giai đoạn ra hoa) phụ thuộc vào những yếu tố hóa học, vật lý, các yếu tố vi lượng độ tuổi của mẫu và các chất điều hòa sinh trưởng. Trong nghiên cứu này, chúng tôi tiến hành kiểm tra một vài yếu tố ảnh hưởng đến khả năng biệt hóa của những chồi hoa Torenia fournieri L. in vitro. Kết quả chỉ ra rằng những chồi già hơn cho tỷ lệ hình thành hoa cao hơn. Các chồi 60 ngày tuổi có tỷ lệ hình thành hoa là cao nhất (65 %) sau 30 ngày nuôi cấy. Hơn thế nữa, hàm lượng khoáng vi lượng, khoáng đa lượng, nồng độ đường, các chất điều hòa sinh trưởng, than hoạt tính và điều kiện chiếu sáng cũng có ảnh hưởng đáng kể đến khả năng ra hoa. Những chồi được nuôi cấy trên môi trường ¼MS không bổ sung chất điều hòa sinh trưởng, có bổ sung thêm 60 g/l sucrose, 1 g/l than hoạt tính với chu kỳ chiếu sáng là 10 giờ sáng (45 µmol.m-2.s-1)/14 giờ tối cho tỷ lệ ra hoa là cao nhất 87,18 % với 2,8 nụ hoa/mẫu cấy. Các hoa in vitro và ex vitro không có sự khác biệt về hình thái và màu sắc.
EFFECT OF VARIOUS FACTORS ON THE FORMATION OF AMINOREDUCTONE DURING THE MAILLARD REACTION
Authors: Trang Vu Thu
Published: April 2018

To create a basis for the production of aminoreductone (AR) followed by the use of it as a functional ingredient in food supplements, the effects of heating temperature, heating time, buffer concentration and reducing sugar/amino compound ratio on the formation of aminoreductone (AR), a product formed during the initial stage of the Maillard reaction,were investigated. In the model solution of lactose (262 mM) and butylamine (1.16 M) in 1.28 M phosphate buffer (pH 7.0), AR formation increased during the prolongation of the heating time at heating temperature less than 100oC. In the heated model solution at 100 oC, the maximum amount of AR was obtained as soon after 10 min of heating time. After that, the decreases of the AR formation was observed by the progress of the advanced reactions of AR. The rates of AR formation increased with the increasing phosphate buffer concentration. Moreover, the increasing in AR formation incorporated in the increase of the butylamine/lactose ratio from 0.1 to 5. Our results might give more insight in the discovery of Maillard reactions in food because it suggested tendency of the AR formation and to control the formation of AR during food processing and model system base on the control of initial constituents and reaction conditions.
NGHIÊN CỨU HIỆU ỨNG KÍCH KHÁNG BỆNH CỦA β-GLUCAN CẮT MẠCH BẰNG PHƯƠNG PHÁP CHIẾU XẠ ĐỐI VỚI CÁ RÔ PHI
Authors: Duy Nguyễn Ngọc
Published: April 2018

β-glucan khối lượng phân tử thấp (LMWβG) và dung dịch oligoβ-glucan đã được chế  tạo bằng phương pháp hấp thủy nhiệt kết hợp với phương pháp chiếu xạ tia gamma Co-60. Ảnh hưởng quá trình cắt mạch đến sự thay đổi khối lượng phân tử (KLPT) đã được xác định bằng sắc kí gel thấm qua (GPC). Kết quả thu được cho thấy KLPT giảm khi tăng thời gian hấp, nồng độ H2O2 và liều xạ. Đối với LMWβG KLPT giảm từ 296.600 Da xuống 44.400 Da khi nồng độ H2O2 tăng từ 0 lên tới 10 % và đối với oligoβ-glucan KLPT giảm từ 56.700 xuống còn 7.100 Da khi chiếu xạ dung dịch β-glucan/1 % H2O2 tại liều xạ 16 kGy. Cá rô phi được cho ăn thức ăn có bổ sung LMWβ và oligoβ-glucan ở hàm lượng 100 mg/kg thức ăn trong vòng 45 ngày và sau đó được gây nhiễm bệnh với vi khuẩn Streptococcus agalactiae để khảo sát hiệu ứng kích kháng bệnh. Kết quả cho thấy oligoβ-glucan có hiệu ứng kích kháng bệnh cao hơn LMWβ và tại hàm lượng 150 mg/kg thức ăn, tỉ lệ cá sống sót sau khi gây nhiễm bệnh đạt cao nhất (76,75 %) đối với oligoβ-glucan
DESIGN OPTIMIZATION OF EXTREMELY SHORT-CHANNEL GRADED SI/SIGE HETEROJUNCTION TUNNEL FIELD-EFFECT TRANSISTORS FOR LOW POWER APPLICATIONS
Authors: Chien Nguyen Dang
Published: April 2018

This study investigates, by a two-dimensional simulation, the design optimization of a proposed 8 nm tunnel field-effect transistor (TFET) for low standby power (LSTP) applications utilizing graded Si/SiGe heterojunction with device parameters based on the ITRS specifications. The source Ge mole fraction should be designed approximately 0.8 because using lower Ge fractions causes severe short-channel effects while with higher values does not significantly improve the device performance but may create big difficulties in fabrication. Based on simultaneously optimizing the subthreshold swing, on- and off-currents, optimum values of source doping, drain doping and length of the proposed device are approximately 1020 cm-3,                1018 cm-3, and 10 nm, respectively. The 8 nm graded Si/SiGe TFET with optimized device parameters demonstrates high on-current of 360 μA/μm, low off-current of 0.5 pA/μm, low threshold voltage of 85 mV and very steep subthreshold swing of sub-10 mV/decade. The designed TFET with graded Si/SiGe heterojunction exhibits an excellent performance and makes it an attractive candidate for future LSTP technologies because of its reality to be fabricated with existing FET and SiGe growth techniques.
ASSESSMENT OF ARSENIC CONTAMINATION IN THE RED RIVER: HIGH RESOLUTION MONITORING COUPLED WITH SPATIAL ANALYSIS BY GIS
Authors: Hà Dang Thi
Published: April 2018

The Red River (China/Vietnam, A = 155 000 km2) is a typical humid tropics river originating from the mountainous area of Yunan Province in China. Based on two sampling campaigns covering the whole Vietnamese watershed in 40 sites at low and high water levels during 2009, the seasonal and spatial variations of As concentrations in dissolved and particulate phases were determined. The dissolved As concentrations in rainy season were relatively lower than in dry season, suggesting the dilution effect of less arsenic-contaminated water. In contract, the particulate As concentrations during low water level were clearly lower than that during high water level, demonstrating a change phenomenon in As source(s) with hydrology. In addition, in order to assess spatial distribution of the As contamination in the Red River watershed and localize geochemical anomalies, multidimensional statistical analyses combined with As maps generated by GIS tool were used. The results showed that the highest As concentrations are originated from the upstream catchment and strongly decrease from upstream to downstream. Finally, the comparison between dissolved As concentrations from the Red River watershed and the national technical regulation on surface water (QCVN 08:2008/BTNMT) indicated that the quality of water in the Vietnamese Red River watershed can be classified as poor quality in the upstream part and as mediocre quality in the downstream part.
STUDY ON INFLUENCE OF TEMPERATURE AND DURATION OF HYDROTHERMAL TREATMENT TO PROPERTIES OF NANO FERRITE NiFe2O4 MATERIALS
Authors: Dat Tran Quang
Published: April 2018

NiFe2O4 superparamagnetic nanoparticles have been prepared by the method of spraying - co-precipitation subsequent by hydrothermal treatment. This procedure allowed to produce efficiently nanoparticles with high performances. Different techniques such as XRD, TEM, EDX, VSM were used to investigate the morphology, structure and magnetic properties of the obtained materials. It is shown that the materials have face-centered cubic trevorite structure, and their degree of crystallinity and magnetic properties improved with increasing temperature and time of hydrothermal treatment. After 32 hours of hydrothermal treatment at 160°C, NiFe2O4 nanomaterial has particle size of about 23 nm and saturation magnetization (Ms) of 49 emu/g.
THE PHYSICS OF SPIN-1/2 XY MODEL WITH FOUR-SITE EXCHANGE INTERACTION ON THE KAGOME LATTICE
Authors: Kim Anh Nguyen Thi
Published: April 2018

The quantum spin liquid (QSL) state, proposed more than three decades ago by Fazekas and Anderson remains surprisingly elusive. Although recent experiments provide a strong evidence of their existence in the frustrated spin systems, the microscopic model for this state is still rare. The extensive theoretical framework, developed over decades, continues to extend further motivated by these and other discoveries from large-scale computer simulations of a relatively small number of models. In this work, we discuss the physics of the ground-state phase diagram of a two-dimensional Kagome lattice spin-1/2 XY model with a four-site ring-exchange interaction using quantum Monte Carlo simulation. We found the second order phase transition from superfluid state to a Z2 quantum spin liquid phase driven by the four-site ring exchange interaction. We have characterized the QSL by its vanishing order parameters such as the spin-spin structure factor, the plaquette-plaquette structure factor. Moreover, we have found the large anomalous exponent ηXY* ≈ 1.325 which belongs to a different universality class other than 3D XY universality class. There is no signal of supersolid phase intervening between the superfluid state and QSL state.
EFFECT OF Ag NANOPARTICLE ON THE PHOTOCATALYTIC ACTIVITY OF TIO2 NANOTUBES
Authors: Ngoc Tu Le Thi
Published: April 2018

The TiO2 nanotubes were fabricated by the hydrothermal method. Then, Ag nanoparticles with the varying ratio were attached on the TiO2 nanotubes by photoreduction. The characteristics of structure, morphology, chemical composition and of TiO2 nanotubes modified Ag (Ag-TNTs) was investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and the absorption spectral of Methylene blue (MB) solution. The results showed that Ag-TNTs have fairly uniform length with Ag particles immobilized on the tube. The photocatalysis TiO2 nanotubes (TNTs) is higher than Ag-TNTs in UV range and lower than Ag-TNTs in the visible light. And the photocatalytic activity of Ag-TNTs with 5 wt.% Ag is highest in the visible range.
HIGHLY ANISOTROPIC MnBi MAGNETS
Authors: Vuong Nguyen Van
Published: April 2018

The rare-earth-free MnBi magnetic material is promising for high-temperature (150 200 oC) application of permanent magnets because of its large magnetocrystalline energy and especially the positive thermal coefficient of coercivity (dHc/dT > 0). Because of the moderate value of the spontaneous magnetization Ms 74 emu/g, the anisotropy of MnBi bulk magnets should be investigated to enhance the remanence Mr. With large ratio Mr/Ms and appropriate microstructure, the squareness of MnBi magnets should have high value leading the remanent coercivity bHc close to the intrinsic coercivity iHc, thus enhancing the energy product (BH)max. The paper presents an approach to loading and compacting of MnBi powders in the 18 kOe magnetic field oriented perpendicular to the pressing direction where MnBi grains can be freely rotated and oriented parallel to the field direction. Based on the energy minimization of the assembly of magnetized grains, the compacting pressure was chosen to optimize two parameters, the mass density and the coercivity iHc of magnets. The prepared MnBi bulk magnet had 8.4 g/cm3, Mr/Ms 0.92, 0.89 and (BH)max reached 8.4 MGOe.
OPTICAL PROPERTIES OF Eu3+ IONS IN LaF3 NANOCRYSTALS
Authors: Ha Hoang Manh
Published: April 2018

LaF3 nanocrystals doped with different concentrations of Eu3+ ions were synthesized by hydrothermal method. The XRD, luminescence and excitation spectra have been studied at room temperature. The ratio of the 5D0→7F2 electric dipole transition intensity to the 5D0→7F1 magnetic dipole transition intensity (R) was used to evaluate the asymmetry of Eu3+ site. Judd-Ofelt parameters were calculated from emission spectra and were used to predict the radiative properties of 5D0→7FJ transitions also the lifetime of 5D0 level. The small values of Ω2 parameter and R ratio relate to high degree of symmetry of ligand around Eu3+ site in this material.