A study on the corrosive inhibition ability of CT3 steel in 1 M HCl solution by caffeine and some characteristics of the inhibition process

Caffeine was isolated from dry green tea leaves and used as corrosion inhibitor. The aim of this paper is to study the corrosion inhibition behavior of caffeine with its different concentrations (from 0.01 g/L to 3.00 g/L) for CT3 steel in 1M HCl solution by the curve polarization measurements and surface examination studies. Experiment result showed that: as the concentration of caffeine increases, the inhibition efficiency increases; %IE max is approximately 83.27% at concentration of caffeine 3.00 g/L. The experimental data from all measurements was found to  fit well with the Langmuir caffeine adsorption isotherm. Calculated values of free energy of adsorption DGads are -14.71 kJ/mol. It shown that, the adsorption is spontaneous and consistent with the mechanism of physical adsorption. It showed that, the adsorption is spontaneous and consistent with the mechanism of physical adsorption. As temperature increase from 298 to 318 K, the inhibition efficiency is relatively stable: decrease slightly from 83.27 % down 78.50 %. Calculated values of the heat of adsorption DHads are ranged from -6.38 kJ/mol to -19.89 kJ/mol, indicating  that  the adsorption of caffeine on the surface of CT3 steel is exothermic. The increasing of activation energy  in corrosion process which presents caffeine 3.00 g/L compared to absent caffeine proved that caffeine have corrosion occurred more difficult

Natural Frequencies of Exponential Functionally Graded Beams based on Classical Beam Theory

In this paper, the natural frequencies of exponential functionally graded beams are determined from two separate formulations, one based on an analytical approach and the other based on a numerical approach. The classical beam theory is carried out with various boundary conditions. The results obtained in this paper are presented and compared with other results in the references to verify the correctness in implementing the formula and writing the Matlab code. This paper can help researchers have an overview of the vibration characteristics of the exponential functionally graded beams. Furthermore, they can enhance their research by modifying more advanced materials such as beams reinforced by graphene platelets, beams' shape, etc. Last but not least, with the strong application of the functionally graded material in real life, it would be good if there were more data related to this issue

Drought stress - related functional characterization of transcription factor GmNAC085 in soybean

Studies on soybean GmNAC085 transcription factor revealed that the gene expression in plants was induced by water shortage treatments and its overexpression in the model plant Arabidopsis displayed improved plant tolerance characteristics towards drought stress. In this study, we continued analyzing the biological functions of GmNAC085 using transgenic soybean system overexpressing GmNAC085 gene, by targeting at a number of plant physiological features and biochemical activities in response to limited water growing condition. Compared to the wild-type, the transgenic line demonstrated that it possessed stress tolerance characters, including enhanced elongation of taproot, minimized reduction of shoot growth, lower intracellular H2O2 content and stronger peroxidase enzyme activity under drought condition. The results of this study therefore suggest the transgenic plants had better drought tolerance and the GmNAC085 plays important role in aiding plants to cope with water deficit condition, probably via regulating the growth of roots and shoots, and activities of reactive-oxygen-species- scavenging enzymes

Role of GmNAC019 transcription factor in salinity and drought tolerance of transgenic Arabidopsis thaliana

Increasingly severe drought and salinity stress due to global climate change have made these stresses bigger threats to ecosystem and agriculture. Previous studies reported that GmNAC019, a soybean NAC transcription factor - encoding gene, displayed induced expression upon drought treatment in wild-type cultivars. In this study, drought and salinity stresses were applied on GmNAC019-overexpressing Arabidopsis plants to verify the contribution of GmNAC019 in regulating plant response to the stress conditions. Results from the water loss rate and survival rate assays revealed that the transgenic line conferred improved tolerance to drought stress as evidenced by lower leaf water loss and significantly higher rate of survival than seen in the wild-type plants. Similarly, the survival rate assay for testing salinity effects on plants by growing the plants on MS medium supplemented with different NaCl concentrations also indicated that the transgenic plants had a better tolerance to salt stress as they displayed lower rate of root growth inhibition and higher survival rate. Taken these results altogether, it is suggested that GmNAC019 might play important role in aiding plant response to drought and salinity stresses. Specific functions of this gene should be elaborated in future studies to evaluate its potential application for crop improvement

Growth and development of transgenic peanut (Arachis hypogaea) lines containing chitinase 42 kDa gene from Trichoderma asperellum SH16

Peanut (Arachis hypogaea L.) is vulnerable to many diseases. Vietnam and other regions where peanut is widely cultivated have a high threat of fungal and other plant diseases. Various fungicides are available to control the fungal disease but these have various harmful effects on the natural flora, fauna, and environment. Transgenic peanut lines which possess antifungal activity provide a possible solution in managing fungal diseases apart from the traditional resistance and fungicide usage. Therefore, this study evaluated the probable growth and development of chitinase transgenic peanut lines against Sclerotium rolfsii, a pathogen that causes “southern blight” in plants, under greenhouse conditions. This study provided evidence that through Agrobacterium itumefaciens mediated transformation, 42 kDa chitinase genes from Trichoderma asperellum, which is under the regulation of 35S promoter, were successfully incorporated into the peanut’s (A. hypogaea L.) genome and expressed in their plants. This evidence also demonstrated that transgenic peanut lines were suitable for growing and developing in the greenhouse. Further, it was reported that transgenic peanut lines took approximately 133 to 145 days from planting to maturity. These results also revealed that various growth characteristics of transgenic peanut lines having two synthetic genes (syncod Chi42-2 i.e. S2-2, S2-4, S2-6, and syncod Chi42-1 i.e. S1-1, S1-2, S1-3) were greater than that from the wild-type Chi42 (WT-1, WT-2, and WT-3). In addition, yield-related parameters including the number of mature pods, 100 pods weight and 100 seeds weight for all the transgenic peanut lines were higher than that of the non-transformed plant. Among the transgenic lines, line S2-4 exhibited significantly higher growth and yield than the other transgenic lines. These results demonstrated that 42 kDa chitinase genes overexpressing peanut lines could be a candidate for improvement against plants to phytopathogenic fungus S. rolfsii and high yield.

Assessment of Antioxidant and Antibacterial Activities of Lactobacillus farciminis HN11 as a Probiotic Candidate

Background and Objective: Lactobacillus farciminis is an obligate homofermentative bacterial species in fermented foods. Although other species such as Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus casei and Lactobacillus rhamnosus in Lactobacillus genus have been well characterized, probiotic characteristics of Lactobacillus farciminis still need to investigate. Thus, the objective of this study was to investigate probiotic characteristics and antibacterial activity of Lactobacillus farciminis HN11 isolated from Solanum macrocarpon sauces in Hue city, Vietnam. Material and Methods: Lactobacillus farciminis HN11 was cultured in Rogosa and Sharpe media and antibacterial activity of the free-cell suspension was assessed against Escherichia coli, Vibrio parahaemolyticus K5, Vibrio parahaemolyticus KS-02, Vibrio owensii KS-05, Vibrio alginolyticus KS-08, Vibrio alginolyticus A1-1 and Staphylococcus aureus using agar well diffusion method. Various probiotic characteristics of the isolate including antibacterial and antioxidant activities, autoaggregation and coaggregation were assessed. Furthermore, hemolytic and amino-acid dercarboxylase activities were assessed for biosafety assessment. The strain abilities to resist sodium chloride and bile salts were assessed as well. Results and Conclusion: Lactobacillus farciminis HN11 exhibited significant resistance to NaCl and bile salts. The strain expressed high coaggregation abilities for Escherichia coli, significant autoaggregation abilities and antibacterial activities against Vibrio spp. and Escherichia coli. Antioxidant assessment showed that Lactobacillus farciminis HN11 contained high antioxidant activities. This strain was negative for hemolytic and amino-acid dercarboxylase activities. Moreover, ampicillin and chloramphenicol inhibited growth of Lactobacillus farciminis HN11. This study assessed characteristics of Lactobacillus farciminis HN11 and showed its great potentials as a probiotic in fermented foods, enhancing antioxidant and decreasing harmful foodborne bacteria. Although, encapsulation of the strain within acid resistance materials is suggested to better protect it against high-acid contents of the stomach. Conflict of interest: The authors declare no conflict of interest

GENETIC POLYMORPHISM OF 23 Y-CHROMOSOME SHORT TANDEM REPEAT LOCI IN THE KINH POPULATION OF VIETNAM

Y-chromosome microsatellites or short tandem repeats (STRs) have been proved to be ideal markers to delineate the differences between individuals in human population. Nowadays, Y-STR testing using the PowerPlex® Y23 amplification kit is considered as an extremely sensitive analysis method and has the potential to be used to perform forensic caseworks, and to explore the complexity in population substructures. However, little is known about the forensic Y-chromosome databases in the Vietnam population. In this study, 23 Y-STR loci (DYS576, DYS389I, DYS389 II, DYS448, DYS19, DYS391, DYS481, DYS549, DYS533, DYS438, DYS437, DYS570, DYS635, DYS390, DYS439, DYS392, DYS393, DYS458 DYS456, DYS643, YGATAH4, and DYS385a/b) were investigated in 120 non-related males of the Kinh population in Northern Vietnam using PowerPlex® Y23 system kit (Promega). Our results showed that allele frequencies of 23 loci in the sample population, with the calculated average gene diversity (GD) for each locus, ranged from 0.24 (DYS438) to 0.92 (DYS385a/b). In addition, a total of 120 different haplotypes were found, all of them were unique. Therefore, we found that the haplotype diversity was 1 with a discrimination capacity of 100%, which serves as an essential prerequisite for using Y-chromosomal STR with PowerPlex® Y23 System kit in forensic application in Vietnam. We also compared genetic distances between Kinh population and 10 other neighboring populations from Y-chromosome haplotype reference database (YHRD). The Kinh population is significantly different from other populations. In conclusion, it was indicated that the 23 Y-STR loci were highly genetically polymorphic in the Kinh population in Vietnam and might be of great value in forensic application

In vitro bioactivities of Codonopsis javanica root extract from Kon Tum province, Vietnam

Dangshen Codonopsis javanica exhibits invaluable medicinal properties in herbal remedies; however, there has currently not been much specific analysis of the phytochemicals and bioactivities of this plant. The root ethanol extract of C. javanica contains substances such as saponins, phenolic acids, terpenoids, and alkaloids. It displays an antibacterial effect against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus cereus with the IC50 values of 150, 100, 150, and 90 μg/mL, respectively. The antioxidant capacity of the root extract was also observed with an IC50 value of 46.8 ± 6.8 μg/mL. Furthermore, the extract exhibits activity on human cancer cell lines HepG2 (IC50 = 83.6 ± 2.7 μg/mL) and MCF-7 (IC50 = 95.3 ± 2.3 μg/mL). Hence, this study provides the basic data for further research on the bioactivities of natural compounds of Dangshen C. javanica for the first time

Surface water quality modelling with data scarcity in semi-enclosed coastal regions encompassed distributed islands

Water quality variation in semi-enclosed urban coastal areas with different pollutant sources is a substantial issue. Pollutant entrapment has a significant impact on the lives of the local people. Surface water quality modelling often requires large datasets covering bathymetry, fluid and pollutants boundary conditions, sources and sinks. This is particularly challenging in regions with complex features and poor data availability, such as coastal water bodies featuring a large number of widely distributed islands and estuaries. In this paper, we developed a model of surface water quality and hydrodynamics for Ha Long Bay, in the North of Vietnam and includes 1969 islands, for a one-year period using a water quality dataset obtained for this study. The model utilized extracted bathymetric and geometric data from Admiralty Charts and Admiralty Tide Tables. Water quality coupled with the TELEMAC Model (WAQTEL) Biomass Module was employed to predict pollutant transport in the domain using point and diffused sources while field studies were conducted to collect data for the setting up and calibration of the water quality model. Thirty scattered sampling points were selected, and the water quality parameters were measured during two campaigns. The predicted water level and velocity values matched the local observation data well with a small error (RMSE = 0.19 and 0.16). Both NO3−-N and PO43--P were high near the shoreline and decrease gradually offshore. The maximum concentrations of NO3−-N and PO43--P reached 0.476 mg/L and 0.048 mg/L at the end of 2021 with the RMSE = 0.13 and 0.011, respectively. The levels of NO3−-N and PO43--P and their distributions showed that Ha Long Bay was eutrophic even during the COVID-19 lockdown period

Vegetable seed systems for ethnic minorities in northern Vietnam for enhanced nutrition and income

Vegetables are a main source of nutrition and income for ethnic minority farmers in Vietnam’s Northern highlands. While the consumption of vegetables and value chains for fresh retail produce and seed markets offer huge opportunities for household nutrition security and development, and particularly women inclusion, current smallholder systems suffer from multiple problems. The Integrated vegetable seed systems development project addressed these issues by elucidating how, and under what conditions, increased access and use of high-quality seed translates into enhanced smallholder nutrition and income security. This poster provides the project highlights presented at the NL-CGIAR Conference, 2-3 November 2022