Functional near-infrared spectroscopy (fNIRS) is a non-invasive technique utilized to measure hemoglobin concentration of human brain signal. Temporal resolution of this method is high (aproximately 1 ms). However, its spatial resolution is limited (approximately 10 mm) compared with other non-invasive techniques. Therefore, in the present study, fNIRS based 32-optodes are utilized to measure human brain hemodynamic response of 5 male participants with arithmetic tasks. Coordinates of 256 voxels are computed based on the optode geometry. Coefficient of differential path-length factor in Beer-Lambert equation is estimated as a distance function to compute absorption coefficients. The mean concentration of Oxy- and deOxy-hemoglobin obtained from absorption coefficients is utilized to reconstruct 3-dimension brain imaging. The experimental results showed that the proposed method can detect the brain activity with higher spatial resolution than that using conventional approach.

Besides being the source of anticancer compounds, the yew (Taxus wallichiana) is also rich in other various potential secondary metabolitics which have been applied in agriculture and aquaculture. Among of them, b-ecdysone, a hormone in moulting induction in insects and crustaceans. By using chromatographys, 1D and 2D nuclear magnetic resonance (NMR) spectral analysis and comparison with standard b-ecdysone compound, b-ecdysone was isolated from the yew leaves, growing in Da Lat city, Lam Dong province. After extracted by segmental shaking with ethyl acetate and analysed by high performance liquid chromatography (HPLC), the b-ecdysone concentration was determined by 55 mg/kg of dried leaves.

Hydrocarbons such as benzene, toluene, and xylene (BTX) have been widely used in life and especially, they are the major components in many petroleum products. BTX have been considered as the environmental contaminants as they pose hamful effects on living organisms as well as on human health. The aims of this study were isolation and screening for indigenous bacteria capable of effectively degrading BTX compounds. Twenty-one bacterial isolates isolated from five sediment samples in a wastewater tank of a petroleum refining plant grew in minimal salt medium supplemented with BTX compounds as the only carbon source. Among these, two bacterial isolates BTX-S21 and BTX-S22 were capable of producing higher biomass as compared to others on minimal salt medium supplemented with different concentrations of BTX including 0.01; 0.025; 0.05; 0.1; 0.25; 0.5 and 1% (v/v) for each compound. In the liquid media containing four different concentrations of BTX compounds such as 0.01; 0.05; 0.1 and 0.25% (v/v), BTX-S21 degraded 100% benzene, 100% toluene and more than 92% xylene after 24 hours of inoculation.

Heterocyclic compounds containing 1,3,4-oxadiazole or benzimidazole core substructures have been known to possess diverse bioactivities such as antimicrobial, antifungal, analgesic, anti-inflammatory, antiviral, anticancer, anti-hypertensive, anti-diabetes and antioxidant and are considered to be important candidates for further development of new medicines. Combination of these two structural features is, therefore, expected to produce more potently bioactive compounds. In this research, a synthetic path way has been successfully developed for the synthesis of hybrid 1,3,4-oxadiazole/benzimidazole derivatives. The strong points of this synthetic method come from the simpleness, effectiveness, and cheapness and environmental friendliness thank to using non-toxic oxidants including MnO2 and I2/K2CO3. Based on this method, four hybrid 1,3,4-oxadiazole/benzimidazole derivatives were successfully synthesized in good yields (63-67 %).

In this theoretical study, the structures and energetic properties of several closo-hydroborate dianions BnHn2– (n = 5 - 12) and gold clusters AuN (N = 2 - 20) are systematically investigated by means of DFT calculations. Global equilibrium geometries are determined or confirmed, and the growth mechanism is then established. Several thermodynamic parameters including atomization energy, heat of formation, ionization potential and electron affinity are also computed to evaluate their stability pattern. Computed results show among investigated species that some specific systems are exceptionally stable with closed-shell electronic structures. Their valence electrons generate magic numbers that can be understood using the phenomenological shell model.

In this paper, we give some new explicit sufficient conditions for exponential ultimate boundedness of a class of nonlinear Volterra difference systems with finite delays. The obtained results are generalizations of some existing results in the literature as our particular cases. An example is given to illustrate the obtained results.

The environmental inbiotic factors and the plant growth phases can considerably change the contents of phytosubstances in higher plants. The present study was performed to evaluate the effects of light intensity and plant growth stages on the contents of some biocompounds in plantain (Plantago major L.). As results, the “specific agent reaction” helped find 8 types of biosubstances (flavonoid, alkaloid, phenolic, tannin, coumarine, terpenoid, saponin and glycoside) in the plantain. Spectrometric method showed that the growth stages and light intensity considerably effected on the total contents of phenolic, tannin, and flavonoids compounds in this plant. For growth stages, the total contents of phenol, tannin and flavonoid in the 4-month-old plantain (6.58, 9.03 and 5.98 mg/g FW, respectively) are higher than those in 6-month-old one (2.88, 2.79 and 4.98 mg/g FW, respectively). For light condition, the plantains grew at 75% light intensity possess the highest total contents of these compounds (7.92, 4.25 and 6.74 mg/g FW, respectively), which are significantly different from those at other light conditions. In addition, the result showed the significant interaction between light intensity and plant growth stages on these found biosubstances in the plantain.

In traditional survey, the difference in height between two points is determined by geometric levelling method, which is suitable in case of short distance between two points. When the distance between two points is hundreds of km long, the cost of surveying may become very high. In this paper, two other methods for calculating the difference in height between two points will be introduced. Based on GNSS received data, differences in height are calculated by two methods: (1) subtracting two equipotential surfaces at two points or (2) subtracting the elevations of two points. An experiment was conducted (at Nha Trang and Ho Chi Minh city) in order to verify given formulas. Results showed that errors are acceptable as they do not exceed Acceptable Error Limits, given by Technical Normative Standard, and hence, GNSS would have been a better choice than Geometric Levelling method in some cases.

In this paper, a variant of the balanced optimization problem, where the knapsack constraint is associated, is considered. To solve this problem, a special structure of the feasible solutions is explored. Based on this investigation, a dynamic approach is developed to solve the mentioned problem in linear time.

Nitrogen based heterocyclic compounds containing quinazolin-4-one scaffold have been known to be possess diverse biological activities. In this research, six compounds including three quinazolin-4-one (3a-c) and three N-acetamidyl quinazolin-4-one (8a-c) derivatives were successfully synthesized in good yields. The synthetic process is simple, effective and environmentally friendly using air as the only oxidizing agent.

The chemical composition of Gao trang leaves (Neolamarckia cadamba (Roxb.) Bosser) contained alkaloids, flavonoids, glycosides, polyphenols, tannins and triterpenoids. The total polyphenol and flavonoid contents of N. cadamba were equivalent to 376.43±2.22 mg GAE/g and 613.53±90.39 mg QE/g, respectively. The antioxidant activities of the extract of  N. cadamba leaves were investigated by DPPH free radical scavenging and reducing power (RP) assays. The leaf extract possessed relatively high antioxidant activity, with EC50 value of 52.69 µg/mL and OD0.5 value of 89.68 µg/mL, which were higher than that of references as vitamin C and BHA 1.13 times and 2.97 times, respectively. The hepatoprotective activity of the leaf extract was investigated in mice which were previously treated with CCl4 to induce liver damage. The leaf extract at the dose of 100, 200 and 400 mg/kg body weight effectively reduced the level of alanine transaminase and aspartate transaminase in serum. The leaf extract also improved the oxidative stress status in mice liver through effective reduction of malondialdehyde level and increasing of glutathione level in the liver.

Chalcone derivatives exhibit a wide range of biological activities including: antimalarial, antiinflammatory, antibacterial and anticancer. In this study, a one step procedure for the synthesis of five chalcone derivatives 3A, 3B, 3D, 3E and 3F has been successfully developed with two new compounds (E)-3-(2,5-dimethoxyphenyl)-1-(thiophen-3-yl)prop-2-en-1-one (3E) and (E)-3-(pyridin-4-yl)-1-(1H-pyrrol-2-yl)prop-2-en-1-one (3F). The synthesis method was performed by Claisen-Schmidt condensation reaction between methyl ketone and aromatic aldehyde derivatives in the presence of NaOH as the catalyst in ethanol as the solvent. The obtained yields of 3A, 3B, 3D, 3E and 3F were 70%, 73%, 75%, 90% and 86%, respectively. The structures of these compounds were fully determined by FT-IR, MS, 1H-NMR and 13C-NMR spectroscopy methods. The cytotoxicity assay indicated that compounds 3E and 3F were the most active against Hep-G2 cell line with IC50 of 10,46±0,09 μg/mL and 6,82±0,21 μg/mL, respectively.

The clinical study of bitches with pyometra and the effects of hormonal medroxyprogesterone acetate (MPA) were performed from 8/2016 to 12/2018 by means of a case-control study. The study is aimed to investigate the situation of bitches with pyometra, evaluate the effects of hormonal MPA contraceptives on the increased risk of endometritis in dogs. The results of the study showed that bitches with uterus inflammation in the surveyed area were 12.76%, in which the proportion of dogs with hormonal MPA contraception was 60.22%. In which, the percentage of bitches with uterus inflammation that was injected with MPA hormone once time was 23.21%, with two times was 26.79% and high increasing was 50% with more than two times with MPA hormone injection. Clinically, the symptoms of heavy drinking, vaginal fluids, abnormal abdomen or licking the vulva are reliable clinical signs that guide the diagnosis of uterine inflammation in dogs. The results of a description of the correlation of risk factors based on case-control studies with OR differences also showed a strong correlation between risk factors and disease incidence. The risk of disease in dogs with progesterone was 4.29 times higher than that of non-injected dogs.

Four methods for extracting DNA in cocoa-derived products (cocoa powder, cocoa butter, cocoa mass, and dark chocolate) are described. These DNA extraction methods included four commercial kits DNeasy Plant kit, DNeasy Plant kit with polyvinyl polypyrrolidone (PVPP), QIAamp DNA Stool kit, Wizard Genomic DNA Purification kit. The DNA yield, purity, and quality for four different cocoa matrices are discussed. The yield and purity were determined through spectrophotometry: DNA concentration, DNA purity and PCR positive amplification. Three different conventional PCR reactions were used to assess the quality of the DNA extracted. The Wizard Genomic DNA Purification kit was found to be the best for DNA quality and PCR detection in cocoa powder and dark chocolate ([DNA] = 44.83 (ng/µL); A260/A280 = 1.4-1.7, PCR positive amplification) and ([DNA] = 29.34 (ng/µL) and A260/A280 = 1.4-1.7, PCR positive result, respectively). The cocoa butter matrix gave the lowest DNA yield, and negative amplification results for three the examined extraction methods DNeasy Plant kit with PVPP, DNeasy Plant kit without PVPP, and QIAamp DNA Stool kit [DNA]

Oral vaccine is one of the most potential strategies for gastrointestinal infection due to significant advantages over parenteral vaccines. In order to overcome exsiting hurdles in oral vaccine, namely oral tolerance and antigen dispersion, gut-associated M cell is a target for vaccine delivery. Cellular prion protein (PrPC), an M cell receptor, was experimentally proven to interact with heat shock protein Hsp60. In the previous in sillico studies, two Hsp60-deprived peptides have been predicted to be key-players in this interaction. Therefore, providing PrPC for in vitro binding assay with Hsp60 is desired to confirm the binding activity of the two predicted peptides. In this study, murine PrPC-encoding gene (mPrPc) was cloned into pET-gst to generate recombinant vector namedly pET-gst-mPrPc. Next, the vector was transformed into expression host Escherichia coli (E. coli) BL21 (DE3) for protein expression. SDS-PAGE and Western blot probed with anti-GST antibodies showed the protein expressed in inclusion bodies and hence was subsequently solubilized and refolded. After refolding, GST-mPrPC protein was harvested in soluble form with the refolding efficiency reached 88.33%.

The study was to evaluate the affect of fresh spent coffee ground (FSCG) on growth and yields of maize, soybean and rice and as well soil microbial properties under the greenhouse conditions. Maize, soybean and rice were rotationally cultivated in the same soil type (grey degraded soil) from Moc Hoa, Long An with 4 replicates and 7 different treatments including the control (no fertilization) and five levels (2, 4, 6, 8 and 10%) of FSCG applied (w/w, based on the soil mass) and the treatment with recommended inorganic NPK fertilizer application.  Height of plant, numbers of leaf, tillers of rice, numbers of bacteria and fungi in soil were sampled at day 30, 45 (60), 60 (90) after seedling. Yield of crops and the structure of bacterial community in soil at the end of the study were also collected. The results showed that applying FSCG at doses of 6 and 10% enhanced the growth and yields of soybean and rice, but no maize as compared to the recommended inorganic NPK fertilizer application treatment, increased signicifcantly the numbers of soil bacteria, fungi, nitrogen fixing bacteria and phosphate solubilizing bacteria as compared to other treatments, especially at the end of maize season and during the whole soybean season. Moreover, the structure of soil bacterial community in these two treatments was more diversified than others. Thus, based on the present study it is recommended that fresh SCG can be applied with a dose of 6% or 10% into soil as a soil clean amender to improve soil fertility and crop yield for sustainably agricultural development.

Study on the effect of different feeding frequencies in nursing mud crab was done in order to determine the appropriate feeding frequency for the best growth performance and survival rate of mud crab larvae. The experiment was randomly set up with three treatments such as (i) feeding 4 times a day; (ii) 6 times a day and (iii) 8 times a day. Each treatment was triplicated. Experimental tanks volume was 120 L (100 L of culture volume), stocking density was 450 individuals/L and s water salinity was 30‰. After 12 days of rearing at larvae zoae 4 stage, larvae were transfered to the 500L tank (culture volume of 300L). The survival rate ranged from 42.9 – 51.0%, but there was no statistically significant difference among treatments (p>0.05). After 26 days of rearing, the metamorphic rate of crab1 were 100% andlarvae stage index of larvae in all treatments were not significant difference (p>0.05). Besides, the survival rate of crab1 in the treatments range from 2.6 – 3.0% and there were no significant difference (p>0.05).

Studying on basa catfish (Pangasius bocourti) cultured in cage system in An Giang province was conducted from May to October 2018 through interviewing 55 households in Chau Doc city (20 households), Tan Chau district (20 households) and An Phu district (15 households) culturing basa about technical and economic aspects and advantages and disadvantages of basa cage system. The results showed that each farming household had 3.36 cages with average volume of 623 m3/cage. Fingering fish has the size and stocking density of 61.9 g/fish and 151 fish/m3 respectively. After a culture period of 308 days, the fish reached an average size of 940 g/fish, yield of 1,457 kg/10 m3/crop, achieved a survival rate of 89.1% and an FCR of 1.85. The cost of investing in cage farming is very high, averaging 19.8 million VND/10 m3. With the total cost for 1 crop is 33.3 million VND/10 m3/crop, farmers get profit of 10.75 million VND/10 m3/crop and the benefit ratio is 0.32 times. The greatest difficulties of catfish farming in cage are polluted water, unstable selling price and lack of investment capital for production.

Brown seaweed species of genus Sargassum are of high economic value. However, there was limited information of their distribution and species composition around the Phu Quoc island, Vietnam. The study aimed to provide basic information on the status and composition of the brown seaweed species in Phu Quoc Island. In this study, quadrat method for collecting samples, sampling and analytical methods, species identification, species richness, similarity index to achieve the study’s objective. Nine of the 13 study sites witnessed the presence of 15 species including S. henslowianum, S. muticum, S. binderi, S. fusiforme, S. pallidum, Sargassum sp., S. swartzii, S. hemiphyllum, S. ilicifolium, S. ecuadoreanum, S. brachyphyllum, S. polycystum, S. cinereum, S. siliquosum, and S. wightii. The index of species richness (H’) among the brown seaweed species is high, with a fluctuation between 0.693 and 1.380. S. polycystum and S. brachyphyllum had the highest frequency of co-occurrence with 99.6%. Meanwhile, the brown seaweed species had a relatively high level of similarity index (J’), ranging between 0.985 and 1.000. Additional studies and proper plans are needed to conserve and wisely use brown seaweed resources in Phu Quoc.

The study of supplemented chitosan in feed of striped catfish is aimed to evaluate the effect of chitosan on some non-specific immune parameters of this catfish. The experiment was randomly designed with three replication of four treatments (0, 1, 5 and 10 g/kg of feed), triplication for each treatment. Blood samples were collected in week 2 and 4 after chitosan administration. Then, fish were challenged with Edwardsiella ictaluri. The effect of chitosan on immune response was evaluated through: (i) hematological parameters including total red blood cells, total white blood cells, monocyte, neutrophil, lymphocyte and thrombocyte and lysozyme activity in fish serum; (ii) mortality rate of fish after infection with the E. ictaluri bacterium. The results showed that hematological parameters, lysozyme and complement activity of supplemented chitosan treatments were significantly higher than control in both sampling times. After challenge with E. ictaluri, the mortality of fish in supplemented chitosan treatments was lower than the control treatment (60%). Treatment supplemented 1 g chitosan/kg feed displayed the lowest mortality (40%). The results revealed that suplemented chitosan at level 1 g/kg feed can stimulate the immune response of striped catfish and increase the bacterial resistance of fish.

The objective of this study was to determine the effects of different calcium contents in diet on the maturation and reproductive efficiency of black apple snail (Pila polita). Snail broodstocks were fed with 5 calcium levels; triplicates for each as follow 1% (Ca1); 3% (Ca3); 5% (Ca5); 7% (Ca7) and 9% (Ca9). Snail broodstock with shell height of 35.5 – 42.4 mm were reared in the tarpaulin tanks (1 × 1 × 1 m) with the density of 60 snails/tank and the ratio of male: female was 1: 1. After 90 days of culture, mean GSI of snails in Ca5 (6.3% in male; 13.0% in female) was higher than that of Ca7 (5.7%; 10.2%) and significantly different (p

Scientific research (Research) is not only an important factor enhancing the education quality but also creating new knowledge for university students. A total of 345 students of college of Economics, Can Tho University participated in this research. The result indicated that most of the students just know at some degree about research activities for the students in which 14% of the students did not know anything about the research activities, 81% of them heard but did not find out, and the remaining of 5% have some knowledge about the activities. Besides, almost 5% of the students have ever had and been doing some research and the remaning of more than 95% have not ever done it before. This study also found difficulties and factors affecting scientific research activities of economics students. From this study, solutions are proposed to boost the research activities in the students.

Cultural heritage is a valuable asset of the nation and the institutions. Culture heritage plays a significant role in the process of building and maintaining the country. In the history of our nation, Han Nom culture has become an important part of Vietnam's cultural heritage. In particular, many Han Nom documents are also recognized as world cultural heritage. Han Nom cultural heritage in An Giang province is quite rich and diverse compared to that in other provinces in the Mekong Delta. It is a valuable tourism resource that needs to be preserved and promoted. Therefore, Han Nom cultural heritage could create a special tourism product which contributes to development of An Giang tourism as one of the key tourism destinations in the Mekong Delta, as well as the whole country.

The article shows Vietnamese character explicitly in Thach Lam’s short stories It is one of the outstanding values of the content in his short stories, making his short story both humane and deeply national. Thach Lam’s short stories are like lyric poems to praise the beauty of personality and quality of Vietnamese people in life. Thach Lam has had many artistic creation to depict the character of the Vietnamese identity in his short stories.

Tourism human resources play a decisive role in tourism development. In recent years, the number of international tourists to Vietnam has increased dramatically, requiring the development of international tourism human resources, including French tourism labours. In fact, French speaking labours in tourism are mostly graduates in French Language. Therefore, raising awareness of tourism for French Language students will contribute to responding the demand of French speaking human resources in tourism. This study surveyed career awareness of the tourism industry of 120 French language students at Can Tho University. Research outcomes showed that most of students realize employment opportunities in the tourism industry, but still lack of knowledge and skills about tourism. For that reason, these students need to be equipped with more knowledge and skills about tourism, as well as need to link French language training with tourism training. Since then, a number of solutions were proposed to improve career awareness for students of French Language, meeting the requirements of French speaking tourism human resources in the current international integration trend.

Economic efficiency of  rice production at household level in the Mekong Delta is estimated through marginal profit function of Cobb-Douglas in association with one-step non-economic efficiency estimation. Primary data of 470 rice households were analysed by software of Frontier 4.1 version. Results shows that economic efficiency reached 77.9% and 82.8% in Summer-Autumn 2017 and Winter-Spring 2017-2018 seasons, respectively. Price of seeds (in Summer-Autumn season), fertilizer price (in Winter-Spring season) and pesticide expense in both seasons have causedprofits reduction. Rice household characteristics influencing profits are age of head, experience, education level of household head, technical training attendance and family labour force. In addition, the buyers who consume rice output as well as rice variety category selected for sowing also affect the economic efficiency. Hence, in order to improve economic efficiency of rice production in the Mekong Delta, appropriated use of inputs corresponding to their prices, selecting good channel for selling rice output as well as improving household characteristics must be taken into account.

Access to loan program for social houses attracts people’s attention but not many studies focused on this subject. This paper aims to analyze factors affecting accessibility to the loan program for social houses in Can Tho city. The results from Heckman 2-step model showed that marriage, academic level, income, number of dependents, and unofficial loans significantly influence low income borrowers’ accessibility to bank loans for social houses in Can Tho city. Meanwhile, factors affecting the amount of loans for social houses for low-income people include age, gender, marriage, income, equity gearing and construction area. The results also showed that access to bank loans for social houses by low-income people positively associates with the loan amount. Based on the results, some recommendations to promote low income borrowers accessibility to bank loans for social houses in Can Tho City include mobilizing capital from domestic and foreign sources to supply long-term loans for the low income borrowers, and reforming administrative procedures related to bank loans for investment in construction and purchase of social houses.

This study is aimed to determine factors that influence Winter-Spring rice yield at Agro-ecological zone of West Sea Coastal region, the MeKong Delta, Viet Nam. There were 224 households who plant rice with 295 rice fields in Ca Mau and Kien Giang provinces selected during the interview.The multiple linear regression analysis was used to assess variables significantly influencing rice yield. The result illustrated that rice yield was affected by seven variables; namely number of fertilizer application, number of herbicide application, farm status, irrigation, salinization status, seeding method, and harvest method. Results also showed that rice yields increased with raising number of fertilizer  or herbicide applications. Besides, application of the monoculture field had higher level of productivity than that of inter-cropping or multi-cropping. The fields with water irrigation system yielded more than those without irrigation investment. As a result, mechanizing rice harvest and direct seeding method had a positively effect to rice productivity. Nevertheless, this paper also showed that salinization negatively affected to the Winter-Spring rice yield.

The estimation results from the surveyed data of Central institute of economic management (CIEM) in 2013 indicate that bank loans and number of labor are possitively ralated to the investment of micro, small and medium enterprises. In contrast, fixed assets and competition factors negatively affect the invesment of enterprises. The findings also show that the determinants of profit, experience (age) of enterprises, education level of owners, household enterprises, cooperatives, private enterprises, and limited enterprises do not impact investment decision while joint stock enterprises possitively affect the investment.

In this paper, the factors affecting the Vietnamese enterprise’s implementation of green consumption policies were tested. The study was conducted in 2018 on the sample of 205 enterprises in the Mekong Delta (Vietnam). The Binary Logistic regression model and the group analysis model were used to determine the impact of independent variables on the dependent variable. The result showed that the implementation of green consumption policies in enterprises depends on a variety of factors such as: (1) The awareness and attitudes factors of business leaders for green consumption policies; (2) Institutional and policy factors; (3) Enterprise resources.

The East Coast region of the Mekong Delta includes Tien Giang, Ben Tre, Vinh Long and Tra Vinh provinces. Although the region has a lot of tourism potentials, tourists and revenue from tourism activities are not commensurate with the tourism potential of each locality. Understanding the factors that constitute the ability to attract tourists is an important issue for the exploitation and promotion of tourism strengths. Based on the research model of Hu and Ritchie (1993) and primary data collectted from 164 questionnaires. The results of linear regression analysis show that the factors affecting the tourist attractability of the East Coast of the Mekong Delta Delta, from high to low levels of influence, are: natural factors, socio-culture factors and support characteristics.