210 research outputs found

    STUDY ON ANTIOXIDANT ACTIVITIES OF THE AERIAL PARTS AND SOME COMPOUNDS ISOLATED FROM Archidendron clypearia ((Jack) I. Niels Part 2. ISOLATING, DETERMINING STRUCTURE AND ANTIOXIDANT CAPABILITY OF SOME COMPOUNDS FROM ETHYL ACETATE EXTRACT

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    The antioxidant activity in vitro of methanol extract of Archidendron clypearia was evaluated by in vitro tests on isolated liver cells of mouses with ED50 value ​​ of 2.18 μg/mL compared to that of curcumin of 1.87 µg/mL. Using combined chromatographic methods, four compounds were isolated from chloroform extract of the Archidendron clypearia. Their structures were elucidated to be daucosterol, 1-octacosanol, docosenoic acid, and methyl gallate by 1D- and 2D-NMR spectroscopic methods and in comparison with those reported in the literature. This is the first report of these compounds from the plant. All four compounds showed quite high antioxidant activity, for which methyl gallate was the highest one

    Using fly ash treated by NaOH and H2SO4 solutions for Hg2+ and Cd2+ ion adsorption.

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    This paper presents the results of adsorption ability of heavy metal ions (Hg2+ and Cd2+) by fly ash (FA) before and after treatment using NaOH and H2SO4 solutions.  Original- and treated FA were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM). Specific surface area of FA before and after treatment was calculated by Brunauer – Emmett – Teller (BET) isotherm equation. The obtained results indicated that the morphology and specific surface area of FA changed clearly after treatment by acid or alkaline solutions. Adsorption capacity the Hg2+ and Cd2+ ion by FA was determined from data of UV-Vis spectra. After treatment, the adsorption capacity of ions by FA increased remarkably in comparison with non-treated FA. The FA treated by NaOH solution has the adsorption capacity higher than FA treated by H2SO4 solution. The maximum adsorption capacity of the FA treated by NaOH solution for Cd2+ and Hg2+ ions at room temperature is 28.97 and 14.60 mg/g, respectively. The equilibrium adsorption data were described by the Langmuir and Freundlich isotherm models. The results showed that equilibrium data were fitted well to the Langmuir isotherm. Keywords. Fly ash, treatment, adsorption capacity, heavy metal, Langmuir isotherm

    Ho Chi Minh's Thoughts On Control Of The State's Power And Lessons For Vietnam

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    In Vietnam, the State’s power is unified, agencies shall assign, coordinate and control each other in the exercises of the legislative, executive, and judicial powers. This is necessary to prevent abuse of power and ensure the state’s power. The Constitution 1946 was written by Ho Chi Minh (1890 -1969) and created a mechanism and foundation to control the state’s power in Vietnam. Nearly, in the Constitution 2013, the issue of controlling state power is recorded. The assignment and control are reflected in the assignment of the scope of power to each state agency. From the approach of philosophical, social philosophy, and political philosophy, through research and analysis documents in Ho Chi Minh Complete Collection; of previous researchers and policies, legal of Vietnam’s Government on control of the state's power and lessons for Vietnam today. The result shows that Ho Chi Minh’s thought on controlling power has shown the basic contents related to asserting that the power owner belongs to the people and focusing on supervision; use the Constitution to limit state power. The article also gives experiences when studying Ho Chi Minh's thoughts on state power control over Vietnam today

    Investigating the diversity of arbuscular mycorrhizal fungi from Gymnema sylvestre and Curcuma longa in Vietnam

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    Arbuscular mycorrhizal (AM) fungi are soil eukaryotes that belong to phylum Glomeromycota and have symbiosis with the vast majority of higher plants’ roots. AM fungi are believed to be coevolved with terrestrial plants, the abundance and diversity of AM fungal communities as a result are host plant dependent. A survey of AM fungi from the rhizospheres of medicinal plants in Northern Vietnam including gurma Gymnema sylvestre and turmeric Curcuma longa was carried out. From the extracted total DNAs of the medicinal plants’ rhizosphere soil samples, 35 mycorrhizal fungal species were identified by analyzing small subunit rRNA gene sequences. Result revealed that genus Glomus is the most abundant in the AM communities of G. sylvestre and C. longa, followed by Gigaspora and Acaulospora. Besides, AM species belonging to genera Scutellospora, Diversispora and Rhizophagus were observed in almost all rhizosphere soil samples. The spore counting by wet sieving and decanting method uncovered a variation in AM spore density of gurma and turmeric rhizosphere. In general, AM species were found more abundantly and more diverse in collected rhizome soil samples of C. longa (27 species belonging to 10 genera) than of G. sylvestre (17 species found belonging to 7 genera). The observed difference in AM communities of G. sylvestre and C. longa supports evidence for the dependence of AM fungal species on host plants, and indicates that AM fungi may have relation to the host plants’ secondary metabolite production

    Development of a nutritional model to define the energy and protein requirements of cobia, Rachycentron canadum

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    This study assessed the protein and energy requirements of Cobia (Rachycentron canadum) using a bio-energetic factorial approach. Using a series of inter-related studies, several parameters were defined to enable the construction of a bio-energetic factorial model for this species. The studies included two controlled laboratory experiments and also extensive field-data collection from commercial and research farms in Vietnam. The devised model includes parameters for both maintenance and protein demands; the effect of fish live-weight on maintenance protein (LW0.697), lipid (LW0.972), and energy demands (LW0.815); the efficiencies of protein, lipid and energy utilisation at various protein, lipid and energy intake levels; and the variability in whole body composition with varying live-weight. The protein utilisation efficiencies (0.456·[protein intake]−0.445), lipid utilisation efficiencies (1.292·[lipid intake]−1.120) and energy utilisation efficiencies (0.651·[energy intake]−48.41) were similar to other carnivorous fish species. However, the maintenance requirements for both energy (74.3kJ/kgBW0.8/d−at 28°C) and protein (0.99g/kgBW0.7/d at 27.9°C) were about double to other species. Using this modelling approach it was possible to iteratively derive optimal dietary protein and energy specifications for this species

    A community participatory intervention model to reduce the health risks from biogas wastewater in Hanam Province, Vietnam

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    In Vietnam, using biogas to treat livestock waste is common, in particular on small holder farms. However, most small holder farms do not know how to use biogas correctly and wastewater can affect health and the environment. Using a participatory approach with farmers and other stakeholders we developed and implemented a set of interventions in Hanam province to reduce health risks from biogas wastewater. Twenty-four pig farmers were selected as a "core group" to be instrumental in developing the interventions and training other farmers to correctly use biogas. The intervention model was piloted for 6 months. Several outputs were obtained including i) approval and enforcement of a "huong uoc - village law" on environmental protection; ii) training of 24 farmers from the core group in communication skills to share information on using biogas; iii) development of a 6-step program of pig cage cleaning to limit waste loaded to biogas to improve the efficiency of biogas production; iv) a health monitoring books for humans and animals for use by families in the community. The results provided evidence that applying the participatory approach can lead to improved knowledge and practices of farmer using biogas and can reduce the health risks from biogas wastewater
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