328 research outputs found
EFFICACY OF Ageratum LEAF EXTRACT ON POSTHARVEST ROT CAUSED BY Aspergillus niger AND Colletotrichum sp. ON CHILLI FRUITS
Abstract: The damage of chilli, an important spice fruit, comes from fungal diseases caused mainly by Aspergillus niger and Colletotrichum sp. The fungi on chilli fruits would directly harm consumers’ health. Plant extracts containing bio-active compounds with antimicrobial properties could be a good possible solution to deal with the fungi. This study aims to evaluate the in vitro and in vivo efficacy of aqueous extracts from the leaves of Ageratum plants against A. niger and Colletotrichum sp. The results show that the optimal efficacy of the treatment of Ageratum leaf extract is at a concentration of 6%, with the efficacy of Ageratum leaf extract on colonial diameter at approximately 43–44% for the two fungi at 96 hours after inoculation. The 6% Ageratum leaf extract has a high efficacy (~54.23%) on limiting the development of Aspergillus rot lesions on chilli fruits 4 days after inoculation. Meanwhile, the efficacy of the extract on Colletotrichum lesions is 11.34%, lower than that of Aspergillus rot.Keywords: Ageratum leaf extract, chilli fruit, rot lesio
Ecpoc: an evolutionary computation-based proof of criteria consensus protocol
Recently, blockchain technology has been applied in many domains in our life. Blockchain networks typically utilize a consensus protocol to achieve consistency among network nodes in a decentralized environment. Delegated Proof of Stake (DPoS) is a popular mechanism adopted in many networks such as BitShares, EOS, and Cardano because of its speed and scalability advantages. However, votes that come from nodes on a DPoS network tend to support a set of specific nodes that have a greater chance of becoming block producers after voting rounds. Therefore, only a small group of nodes can be selected to become block producers. To address this issue, we propose a new protocol called Evolutionary Computation-based Proof of Criteria (ECPoC), which uses ten criteria to evaluate and select a new block procedure in each round. Next, a set of optimal weights used for maximizing the network’s decentralization level is identified through the use of evolutionary computation algorithms. The experimental results show that our consensus significantly enhances the degree of decentralization in the selection process of witness nodes compared to DPoS. As a result, ECPoC facilitates fairness between nodes and creates momentum for blockchain network developmen
The effect of polyamine 70000 (BT70) on the zinc plating process in the non-cyanide alkaline plating bath
The effect of polyamine having molecular weight 70,000u (BT70) in the non-cyanide alkaline plating bath on the morphological zinc electrodeposited coating was investigated. The obtained results from the reflectance of electrodeposited zinc coating by a suitable range of electro-current density and SEM images showed that BT70 had effect on the zinc plating in comparison with the zinc deposits from plating bath without BT70. The electrodeposited coating surface was rough and poor adhesion. However, adding BT70 into the plating bath led to the surface roughness of electrodeposited coating and grand size being reduced. Zinc electrodeposited coating from a plating bath containing BT70 at 0.5 g/L, respectively, experienced the highest reflectance, equal 46 % of the electrodeposited coating from the bath containing commercial additives. Hull method showed that the zinc deposited coating surface became smoother with the presence of polyamine in non-cyanide alkaline zinc plating solution. The zinc deposited coating had a semi-gloss scope at 10 A/dm2. If the BT70 content increased, the semi-gloss scop and the gloss of samples’ surfaces also grew up. Keywords. Polyamine, additive, non-cyanide alkaline zinc plating, zinc coating
Carrot hairy roots (Daucus carota L.) characterisation and optimisation for high β‐carotene extraction
Hairy roots are widely known as a biological system for the production of highly diverse biomolecules. β‐carotene – a precursor for vitamin A – is known to be an anti‐oxidant and anti‐gastric cancer and protection agent against cardiovascular disease, heart disease and stroke. β‐carotene has been chemically synthesised and consumed by humans. However, the chemical process often produces a by‐product that may be harmful to human health. Therefore, this study established a protocol to induce hairy roots (HRs) from a Vietnamese carrot variety and produce natural β‐carotene. The Rhizobium rhizogenes ATCC15834 harbouring Ri plasmid and a Vietnamese carrot variety were used as materials for genetic transformation and HR induction studies. The result showed that approximately 50 HR lines were obtained. Culture medium supplemented with 30 mg/L of sucrose that gave the highest biomass of HR was shown in carrot HR line 30, which had a doubling time of 6.5 days. The highest content of β‐carotene extraction, at 128 mg/100g hairy roots, was achieved with a ratio volume (v/v) of 2‐propanol and plant samples of 20:1, followed by two hours’ incubation with 2‐propanol at 60 °C. Our study reveals a highly efficient protocol for Vietnamese carrot hairy root establishment and multiplication. A very efficient protocol for β‐carotene extraction from the hairy root was established to produce natural β‐carotene that achieves the same β‐carotene quantity as that produced by normal roots. This study provides new insight into the production of high‐content and natural β‐carotene for therapeutic application
Chemical composition and antibacterial activities of essential oils from fruits of Melicope pteleifolia (Champ. Ex Benth.) T.G. Hartley grown in Lam Dong Province, Vietnam
In the present study, chemical composition and antibacterial properties of essential oil obtained from the aerial parts of the Melicope pteleifolia (Champ. ex Benth.) T.G Hartley in Dalat were evaluated. Essential oil was isolated through hydro-distillation. Twenty-nine constituents comprising 100% of the essential oil were characterized by gas chromatography/mass spectrometry (GC-MS) techniques. The major compounds in the essential oil were (+)-Sabinene (34.73%), Cis-α-bergamotene (13.15%), Z-α-trans-bergamotol (5.28%), β-mycrene (4.98%), and 1,3,6-octatriene, 3,7-dimethyl-(4.71%). Antibacterial activities of Melicope pteleifolia essential oil were investigated against Gram-positive and-negative bacteria. Results showed significant activities against Streptococcus pyogenes and Escherichia coli using an agar well diffusion method. The application of this essential oil in preventing and eliminating bacteria could be useful in fields as medicine and cosmetics.
Об одном подходе к построению математической модели сложной системы по ее формальному описанию
В данной работе представлена методика и технология объектно-ориентированного
моделирования сложных систем. Разработана технология построения математической
модели системы по ее формальному описанию.The methods and the technique of object-oriented complex system modeling is presented
in the paper. The technique of building the mathematical model of the system according to its
formal description has been developed
Depression and its associated factors among pregnant women in central Vietnam.
To date, little attention has been given to prenatal depression, especially in low and middle-income countries. The aim of this research was to assess the prevalence of depression and its associated factors amongst pregnant women in a central Vietnamese city. This cross-sectional study included 150 pregnant women from 29 to 40 weeks of gestation, from eight wards of Hue city, via quota sampling from February to May 2019. We employed the Patient Health Questionnaire (PHQ-9) to assess depression. Findings suggest the need to provide routine screening of pregnant women in primary care for depressive symptoms and other mental health problems.This is part of the EBLS proejct of which Prof Eisner is PI. Botnar Fondation is the sponso
Effect of enzyme-assisted extraction on yield, composition, and antimicrobial activity of essential oils from Rosmarinus officinalis L. grown in Lam Dong Province, Viet Nam
In the present study, viscozyme L pre-treatment for aerial parts of Rosmarinus officinalis L. (rosemary), grown in Lam Dong province, was performed to evaluate the effective extraction of essential oils by hydro-distillation. Enzymatic pre-treatment with 1 g viscozyme L enzyme mixed with 5 mL sodium chloride 15% at 50oC for 1 hour, followed by hydro-distillation, was seen to slightly increase the yield of rosemary essential oils from 0.96% to 1.08%. GC/MS analysis showed the presence of 32 compounds in rosemary essential oils, of which the major components were α-pinene (29.71 - 32.17%) and cineol (17.55 - 18.74%) in both the control and the enzymatically treated samples. The results also revealed that rosemary essential oils obtained from both the control and the enzymatically treated samples exhibited moderate antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans in all tested concentrations
Validity of two physical activity questionnaires (IPAQ and PAQA) for Vietnamese adolescents in rural and urban areas
<p>Abstract</p> <p>Background</p> <p>Although physical activity is recognised to be an important determinant of health and nutritional status, few instruments have been developed to assess physical activity in developing countries. The aim of this study was to compare the validity of the short form of the International Physical Activity Questionnaire (IPAQ) and a locally adapted version of the Physical Activity Questionnaire for Adolescents (PAQA) for use in school going adolescents in rural and urban areas in Vietnam.</p> <p>Methods</p> <p>Sixteen year old adolescents from rural areas (n = 137) and urban areas (n = 90) completed the questionnaires in 2006. Test-retest reliability was assessed by comparing registrations after 2 weeks. Criterion validity was assessed by comparison with 7 days continuous accelerometer logging. Validity of the two methods was assessed using Spearman correlation coefficient, intra class correlation coefficients (ICC) and Kappa statistics.</p> <p>Results</p> <p>Reliability of both questionnaires was poor for both the IPAQ (ICC = 0.37) and the PAQA (ICC = 0.40). Criterion validity of both questionnaires was acceptable and similar for the IPAQ (ρ = 0.21) and the PAQA (ρ = 0.27) but a significantly lower validity was observed in rural areas. Both forms poorly estimated time spent on light, moderate and vigorous physical activity. Agreement of both questionnaires to classify individuals was also low but the IPAQ performed better than the PAQA.</p> <p>Conclusion</p> <p>Both questionnaires have a similar and overall poor validity to be used as a population instrument in Vietnam. Low reliability and classification properties in rural areas call for further research for specific use in such settings.</p
Decoding the capability of Lactobacillus plantarum W1 isolated from soybean whey in producing an exopolysaccharide
This study aims at producing exopolysaccharides (EPS) from a lactic acid bacterial strain. The soybean whey-isolated Lactobacillus plantarum W1 (EPS-W1), which belongs to genus Lactobacillus, is identified using the phenylalanyl-tRNA sequencing method. Of all the examined strains, R-49778 (as numbered by BCCM/LMG Bacteria Collection, Ghent University, Belgium) showed the highest capability of producing exopoly-saccharides. Structural characterization revealed a novel exopolysaccharide consisting of repeating units of -> 6)-D-Glcp-(1 ->; -> 3)-D-Manp-(1 ->; -> 3)-6-Glcp-(1 -> and a branch of -> 6)-D-Manp-(1 ->; -> 2)-D-Glcp-(1 ->. This discovery opens up avenues for the production of EPS for food industries, functional foods, and biomedical applications
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