327 research outputs found
IDENTIFICATION AND CHARACTERIZATION OF A PURPLE NONSULFUR BACTERIUM ISOLATED FROM COASTAL AREA OF HAI PHONG FOR USING IN PRODUCTION OF UNSATURATED FATTY ACID (OMEGA 6, 7, 9)
Purple nonsulfur bacteria are a group that has so much biotechnological applications, particularly in producing of functional food rich with unsaturated fatty acids. A purple nonsulfur bacterium (named HPB.6) was chosen based on its strong growth, high lipid and synthesis of unsaturated fatty acid (omega 6,7,9). Studying on basic biological characteristics showed that the cells of HPB.6 were observed as ovoid-rod shape, none motility, Gram negative staining. The diameter of single bacterium was about 0.8-1.0 µm. The cells divide by binary fission and had bacteriochlorophyll a (Bchl a). This bacterium grew well on medium with carbon and nitrogen sources such as acetate, succinate, pyruvate, butyrate, glutamate, arginine, leucine, tyrosine, alanine, methionine, threonine, glutamine, yeast extract and NH4Cl. This selected strain grew well on medium with salt concentrations from 1.5 - 6.0% (optimum 3%), pH from 5.0 to 8.0 (optimum at pH 6.5) and could withstand Na2S at 4.0 - 5.2 mM. Based on morphological, physiological properties and 16S rRNA analysis received demonstrated that HPB.6 strain belongs to the species Rhodovulum sulfidophilum
MACRO-ZOOPLANKTON ABUNDANCE IN RELATION TO METAL ACCUMULATION AND WATER QUALITY IN TRUC BACH LAKE
Urban lake pollution is one of the serious issues due to suffering of waste discharged from householders. However, there is a gap of knowledge about the diversity of zooplankton species and how metals accumulate in zooplankton in urban ecosystems. We addressed this by determining the rule of blooming macro-zooplankton in Truc Bach lake and levels of two essential metals: copper (Cu), and zinc (Zn) and of three non-essential metals: arsenic (As), and lead (Pb) in water samples were determined. The results showed that Cladocerans and copepods are macro-zooplankton dominant species in Truc Bach Lake. Water temperature significantly affects the variety of copepod blooming. Arsenic concentration in water collected from the lake exceeded the safety level of current Vietnamese regulation. As concentration in macro-zooplankton positively correlated with metal concentrations in the water (p 0.05) while the concentration of Cu, Zn, and Pb in water has no significant correlation with the metal in zooplankton’s body. The relative abundance of adult copepods in Truc Bach lake had a negative correlation with As concentration in water (p = 0.01). The higher As concentration in water, the lower relative abundance of copepods was found in the sample
Study on pathogenicity of Colletotrichum gloeosporioides on Coffee in North of Vietnam
Coffee is an important crop in Vietnam and it has recently brought a lot of benefit for the country through export. After coffee leaf rust, anthracnose is the second destructive disease for coffee production and is caused primarily by Colletotrichum gloeosporioides. In order to investigate the pathogenicity of C. gloeosporioides on coffee in the North of Vietnam, we carried out isolation of C. gloeosporioides species from different coffee plantations and found that C. gloeosporioides presents in different parts of coffee including leaf, twig, ripe berry and green berry. The pathogenicity of a total of twenty eight C. gloeosporioides isolates was tested on green berry in laboratory. Interestingly, two most pathogenic isolates were originated from green berry. In detail, the rate of green berry infection by C. gloeosporioides isolates varied from 4.44% to 76.67% and the variation of infection rate was also observed clearly among C. gloeosporioides isolates originating from leaf (14.40% to 45.56%), twig (4.44% to 58.89%), ripe berry (22.20% to 61.10%) and green berry (24.40% to 76.67%). Three selected pathogenic isolates representing for C. gloeosporioides isolates originated from twig, ripe berry and green berry were further tested for pathogenicity on hypocotyl seedling in greenhouse. The rate of hypocotyl seedling infection by C. gloeosporioides isolates originated from twig, green berry and ripe berry is 48.89%, 37.78 and 23.33% respectively. Our data suggests that pathogenicity of C. gloeosporioides is variable and specific among isolates, parts of coffee
A Study on Environmental Costs in Coal Mining Production in Vietnam
This study is conducted to identify and present environmental costs of mining production in the context of sustainable development (SD) and a lifecycle of coal mining firms. This aim is accompanied by two research questions as (i) What are the environmental costs of mining production in theory and practice in a lifecycle of coal mining firms?; and (ii) What are the key determinants of environmental costs of coal mining production in a lifecycle of coal mining firms? In order to achieve this aim, the process of coal mining production is described from the long-term perspective including projecting, building, operating and liquidation stage of a coal mine. On the basis of process analysis the identification of environmental costs is conducted in a model approach. Environmental costs of mining production are analyzed using international case studies and theoretical and practical assumptions regarding environmental costs management in mining production are formulated. The results show that the environmental costs of mining production are varied in the lifecycle of a coal mine and that they also depend on the geographical location of mining firms. Environmental costs of mining production have to be predicted in a long-term perspective including also post-liquidation costs together with taking into account the sources of their covering and models of financing. Keywords: Coal mining production, mine, lifecycle of a mine, environmental costs. DOI: 10.7176/RJFA/11-18-09 Publication date:September 30th 202
Targeting effect of folate on cancer cell through curcumin carrier nano-system
Folate receptor (FR) is well known for its overexpression on surface of various cancer cell lines, which is identical to normal tissue. Folic-based targeting drug delivery systems, therefore, are one of the most effective targeting carriers that effectively bind to FR up-regulated cancer cells. Curcumin was used both for labeling and chemotherapy. The materials were characterized and structurally confirmed by FT-IR spectra, fluorescent images and FE-SEM images. Bioassays were conducted on HeLa and HT29 cancer cell lines after 4 and 12 hours. Results show that folic acid significantly enhanced both targeting efficiency and internalization of curcumin to FR-expressing cancer cells
Synthesis of new simplified hemiasterlin derivatives with α,β-unsaturated carbonyl moiety.
International audienceIn this Letter, we report a convenient and efficient method for the synthesis of new simplified derivatives of hemiasterlin in which the α,α-dimethylbenzylic moiety A is replaced by α,β-unsaturated aryl groups as Michael acceptor. Most of these derivatives have a strong cytotoxic activity on three human tumor cell lines (KB, Hep-G2 and MCF7). Analogs 17b and 17f showed a high cytotoxicity against KB and Hep-G2 cancer cell lines comparable to paclitaxel and ellipticine
Synthesis of new bioisosteric hemiasterlin analogues with extremely high cytotoxicity
International audienceIn this article, we report a convenient and efficient method for the synthesis of new simplified derivativesof hemiasterlin in which the α,α-dimethylbenzylic moiety A is replaced by α,β-unsaturated aryl groupsas Michael acceptor. Most of these derivatives have a strong cytotoxic activity on three human tumorcell lines (KB, Hep-G2 and MCF7). Analogs 17b and 17f showed a high cytotoxicity against KB andHep-G2 cancer cell lines comparable to paclitaxel and ellipticine
Effect of deposition time on gold nanodendrite porous structure and on signals of Hg(II) in environment
The influences of deposition time (tdep) for Au nanodendrite preparation on carbon cloth electrodes on the surface structure, electrochemical behavior and voltammetric signal for Hg(II) detection have been studied. The obtained results showed that from 60 s to 300 s, the longer deposition time, the larger dendrite length as well as the more increased density of dendrite structure became. Calculated from data showed that the electroactive surface area approached to the maximum value of 3.686 cm2 with tdep = 300 s. The typical electrochemical behaviour of the prepared electrodes was mass transfer diffusion to the electrode surface and being considered as planar diffusion. Using DPASV technique, the peak height of Hg(II) could appoach to 52 µA with tdep = 60 s. Keywords. Gold nanodendrite, deposition time, surface structure, electrochemical properties, mercury
The politics of numbers and additionality governing the national Payment for Forest Environmental Services scheme in Vietnam: A case study from Son La province
Payments for forest environmental services (PFES) is a major breakthrough policy in the Vietnamese forestry sector because it contributes 25% of the total investments in the forestry sector and serves as the first market-based instrument employed to protect forests. However, there is little empirical evidence of its effectiveness. Is the policy meeting the core objectives of improving forest cover and forest quality and is it also achieving its claims of supporting local livelihoods? This paper analyses the environmental, social, and economic impacts of PFES in Son La province, the longest standing implementation of a PFES scheme in Vietnam. Our study uses a sampling method that incorporates pre-matching and a before-after-control-intervention approach. Data was collected from government statistics, remote sensing analysis, focus group discussions involving 236 people, surveys with a total of 240 households, and key informant interviews with 45 people. Our findings show that additionality of PFES in Son La is controversial and depends on who collects the data and what data is used to evaluate the impacts of PFES. Data collection is also politicized to serve central, provincial and district government interests. Evidence shows that PFES has provided little additional income to individual villagers to protect forests in Son La. However, total PFES revenue paid to communities generates significant income for village communities. Moreover, not all villagers can receive continuous payments from PFES, meaning that PFES has not become a stable source of income, rendering the permanence of PFES limited. Improving monitoring and evaluation policies coupled with transparent, inclusive, independent mechanisms are essential to providing a more accurate reflection of impacts from PFES in Vietnam
THE AMOUNT AND SPECIATION OF TRACE ELEMENTS TRANSPORTED FROM RICE FIELD TO CANAL DURING A FLOODING EVENT
Trace element pollution of soils, sediments and surface water can pose a risk for the local population and the environment of Vietnam. Rice fields can be affected by storm events, which cause the release of trace elements into surface water and transport them into drinking wells. The aim of this study was to investigate if dissolved and suspended As, Pb and Zn concentrations in surface water of a paddy rice fields and an irrigation canals increased during a flooding event and exceed the Vietnamese Surface Water Quality Standards and WHO Guidelines for Drinking-water Quality. The study site is a rice field area in the Thanh Hoa province in Central Vietnam, which experiences an average of 2.4 storms every year causing overflow of streams and low-order canals. Concentrations of As increased during the flooding event with dissolved As being the prevailing fraction, which followed a late flush behavior. Lead showed no significant difference in concentration over time. Zn concentrations only increased significantly in the canal upstream the field in the morning of the first day. Suspended Zn dominated at that time, following the first flush behavior of TSS concentrations. Concentrations of As, Pb and Zn did not exceed the Vietnamese Surface Water Quality Standards or WHO Guidelines for Drinking-water Quality at any time and they are therefore of no concern for the health of the local populatio
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