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  • 1
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    Online Resource
    Benthic cyanobacteria composition and microcystin concentration in the sediment of the Tri An Reservoir
    Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications) ; 2022
    In:  Vietnam Journal of Biotechnology Vol. 20, No. 1 ( 2022-03-30), p. 163-171
    Details
    In: Vietnam Journal of Biotechnology, Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications), Vol. 20, No. 1 ( 2022-03-30), p. 163-171
    Abstract: The occurrence of cyanobacterial blooms (CYBs) associated with cyanotoxins has been reported worldwide. While planktonic cyanobacteria and the contamination of microcystin (MC) in the water column have been the subject of many investigations, little attention is paid to the benthic cyanobacterial communities and MC concentration in the benthic environment. This study aimed to investigate the benthic cyanobacterial composition and MC concentration accumulated in sediment from the Tri An Reservoir (TAR), Dong Nai province. Benthic cyanobacterial communities and sediment were collected at five sites in dry and rainy seasons. The benthic cyanobacterial communities were morphological observation and identification. Different nitrogen, phosphorus species, and chlorophyll-a (Chl-a) in sediment were analyzed. MCs concentration in sediment was quantified by High-Performance Liquid Chromatography (HPLC). Results indicated that the sediment from the TAR was contaminated with nitrogen. A total of 19 species belonging to 12 genera, 3 orders of cyanobacteria were identified. In which, Anabaena, Oscillatoria, and Microcystis were the three most commonly found in the samples. Surface sediment samples contained high densities of colonial Microcystis. The Chl-a concentration in sediment in dry and rainy seasons ranged from 1.96–3.45 and 0.71–3.15 µg/g fresh weight (FW), respectively. MC was detected in sediment at all sites in both dry and rainy seasons with a concentration up to 191.4±14.2 ng/g FW. The outcome of this study provides basic knowledge on MC and potential MC-producing cyanobacteria in a drinking water supply. Further investigation on the toxic producing ability of the benthic cyanobacteria species from the Tri An Reservoir is required.
    Type of Medium: Online Resource
    ISSN: 1811-4989 , 1811-4989
    URL: Article
    DOI: 10.15625/1811-4989/15367
    Language: Unknown
    Publisher: Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications)
    Publication Date: 2022
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  • 2
    Online Resource
    Online Resource
    Chronic Effects of Silver Nanoparticles on Micro-Crustacean Daphnia lumholtzi
    Vietnam National University Journal of Science ; 2020
    In:  VNU Journal of Science: Natural Sciences and Technology Vol. 36, No. 2 ( 2020-06-26)
    Details
    In: VNU Journal of Science: Natural Sciences and Technology, Vietnam National University Journal of Science, Vol. 36, No. 2 ( 2020-06-26)
    Abstract: This study aimed to enhance our insight on the potential toxicological effects of silver nanoparticles (AgNPs)  into the aquatic environment. To investigate the chronic toxicity of nanoparticles, freshwater micro-crustacean Daphnia lumholtzi was exposed to different concentrations of 0.2, 0.5 µg/l AgNPs, and control, for 21 days. Toxicological endpoints at different growing stages such as the maturation and reproduction were recorded. The reproduction rate of D. lumholtzi exposed to both AgNPs concentrations (0.2 and 0.5 µg/l ) was significantly lower than that of control. In turn, the maturation exposed to both AgNPs concentrations was not significantly different from the control treatment. This result indicates that AgNPs (with a concentration lower than 0.5 µg/l) did not have an adverse effect on the maturation of D. lumholtzi, but AgNPs with a concentration higher than 0.2 caused a toxic effect on the reproduction rate of D. lumholtzi during 21 days of the exposure period. In conclusion, the present results showed that AgNPs have toxic effects on D. lumholtzi and it has the potential to use as good freshwater aquatic zooplankton for assessment on the toxicity of nanomaterials in tropics. The future study should pay more attention to the effect of AgNPs on survival, growth rate, and multiple generations of daphnids to better understand the effects of nanoparticles in general and AgNPs in particular.
    Type of Medium: Online Resource
    ISSN: 2588-1140 , 2615-9317
    URL: Article
    DOI: 10.25073/2588-1140/vnunst.4967
    Language: Unknown
    Publisher: Vietnam National University Journal of Science
    Publication Date: 2020
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  • 3
    Online Resource
    Online Resource
    Investigation of anti-allergic activity of piceatannol from Rhodomyrtus tomentosa fruits
    Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications) ; 2021
    In:  Vietnam Journal of Biotechnology Vol. 19, No. 1 ( 2021-07-18), p. 119-128
    Details
    In: Vietnam Journal of Biotechnology, Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications), Vol. 19, No. 1 ( 2021-07-18), p. 119-128
    Abstract: Piceatannol is a naturally occurring polyphenolic stilbene found in various fruits and vegetables. It has been reported to possess various pharmaceutical properties and health benefit effects such as anticancer, antidiabetes, antioxidant, anti-inflammation, and anti-obesity activities. Recently, Rhodomyrtus tomentosa fruits have been determined to contain a large amout of piceatannol. In this study, piceatannol was extracted and isolated from R. tomentosa fruits collected from Phu Quoc district. Moreover, the anti-allergic activity of piceatannol was investigated using RBL-2H3 cells as an in vitro experimental model. Firstly, piceatannol was isolated from ethyl acetate extract of R. tomentosa fruit powder via using a column chromatography and high performance liquid chromatography eluted by several types of binary solvent systems with different polarity. Subsequently, the characterization of the isolated compound was identified by using the mass spectrometer and nuclear magnetic resonance methods. The degranulation of mast cellls was examined via measuring the release of β-hexsosaminidase in the culture supernatant. Moreover, observation of cell morphology was conducted under the inverted microscope as the RBL-2H3 cells treated with 40 µM of piceatannol. In addition, the cytotoxic effect of piceatannol at the concentration treatment of 40 µM was also tested via MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. As the result, piceatannol treatment significantly inhibited the mast cell degranulation via reducing the β-hexsosaminidase release to 44% at the concentration of 40 µM. Moreover, piceatannol exhibited the protective effect against calcium ionophore-induced morphological change of the RBL-2H3 cells. Notably, no significant cytotoxic effect at the concentration treatment up to 40 µM of piceatannol was observed on RBL-2H3 cells. Therefore, piceatannol from the R. tomentosa fruits could be suggested as a potential anti-allergic agent for future therapeutics.
    Type of Medium: Online Resource
    ISSN: 1811-4989 , 1811-4989
    URL: Article
    DOI: 10.15625/1811-4989/14892
    Language: Unknown
    Publisher: Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications)
    Publication Date: 2021
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  • 4
    Online Resource
    Online Resource
    Using free-living nematode communities as biological monitoring of environmental quality status in Ben Tre city
    Viet Nam National University Ho Chi Minh City ; 2020
    In:  Science and Technology Development Journal - Natural Sciences Vol. 4, No. 4 ( 2020-11-01), p. First-
    Details
    In: Science and Technology Development Journal - Natural Sciences, Viet Nam National University Ho Chi Minh City, Vol. 4, No. 4 ( 2020-11-01), p. First-
    Abstract: Nematode communities were used as a tool to assess the environmental quality status of sediment of the water bodies in Ben Tre city. Eight locations in the main canals and river in the city were surveyed during the rainy season (September). The study recorded 51 genera belonging to 33 families, 10 orders (Araeolaimida, Chromadorida, Desmodorida, Dorylaimida, Enoplida, Monhysterida, Mononchida, Plectida, Rhabditida, and Triplonchida), 2 classes (Chromadorea and Enoplia). The density of nematode communities at most survey locations is quite high, ranging from 29.88 +/- 38.01 to 1172.08 +/- 659.74 individuals/10 cm2. However, the biodiversity is quite low, species richness index (S) ranged from 5.33 1.15 to 18.33 4.72, and Shannon diversity index (H') from 1.28 +/- 0.12 to 3.19 +/- 0.50 and Pielou's evenness index (J') from 0.47 +/- 0.04 to 0.93 +/- 0.04. The Maturity Index (MI) of nematode communities was applied to assess the environmental quality status of sediment. The results showed that the environmental quality status of sediment recorded disturbances, classified as bad to moderate. The colonizer-persister (c-p) combined with the MI is a potential tool in biological monitoring of environmental quality status. However, to increase the reliability of evaluation conclusions, the combination of MI and biological indicators as well as physical-chemical parameters is necessary.
    Type of Medium: Online Resource
    ISSN: 2588-106X , 2588-106X
    URL: Article
    DOI: 10.32508/stdjns.v4i4.866
    Language: Unknown
    Publisher: Viet Nam National University Ho Chi Minh City
    Publication Date: 2020
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  • 5
    Online Resource
    Online Resource
    Using quantitative real-time polymerase chain reaction (qRT-PCR) for detection microcystin producing cyanobacteria
    Viet Nam National University Ho Chi Minh City ; 2021
    In:  Science and Technology Development Journal Vol. 24, No. 2 ( 2021-05-12), p. first-
    Details
    In: Science and Technology Development Journal, Viet Nam National University Ho Chi Minh City, Vol. 24, No. 2 ( 2021-05-12), p. first-
    Abstract: Introduction: Cyanobacterial blooms (CBs) have become a growing concern worldwide. In the natural environment, potentially toxic (can produce toxins) and non-toxic (can not produce toxins) colonies often co-exist within a bloom. Methods: The present study aimed to quantify toxic and non-toxic cells of cyanobacteria in the Tri An Reservoir (TAR) using a quantitative real-time polymerase chain reaction (qRT-PCR). Results: Results showed that the Microcystis genus dominated the cyanobacterial communities in the TAR. Microcystis was also the primary microcystins (MC) producing cyanobacteria in the water. Total cyanobacteria and Microcystis cells ranged from 152103 to 27106 copy/L and from 105103 to 19106 copy/L, respectively. The cell number of potentially MC-producing cyanobacteria (corresponding to the Microcystis mcyD gene) varied from 27103 to 13106 copy/L. MC concentrations often present in raw water with a concentration of up to 4.8 mg/L. Our results showed that the MC concentration in raw water was positively correlated with the mcyD copy number, suggesting that Microcystis spp. are the main toxin producers in the TAR's surface water. Conclusion: Our study suggested that qRT-PCR techniques and traditional count are comparable and could be used to quantify cyanobacteria. In addition, the qRT-PCR techniques can determine the toxic cyanobacterial cells and could be used as a tool for early monitoring of toxic cyanobacteria in lakes and reservoirs.
    Type of Medium: Online Resource
    ISSN: 1859-0128
    URL: Article
    DOI: 10.32508/stdj.v24i2.2523
    Language: Unknown
    Publisher: Viet Nam National University Ho Chi Minh City
    Publication Date: 2021
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  • 6
    Online Resource
    Online Resource
    Assessing Changes in Ecological Quality Status of Sediment in Tri An Reservoir (Southeast Vietnam) by using Indicator of Nematode Communities
    Vietnam National University Journal of Science ; 2020
    In:  VNU Journal of Science: Natural Sciences and Technology Vol. 36, No. 1 ( 2020-03-30)
    Details
    In: VNU Journal of Science: Natural Sciences and Technology, Vietnam National University Journal of Science, Vol. 36, No. 1 ( 2020-03-30)
    Abstract: Nematode communities in Tri An Reservoir (Dong Nai Province, Southeast Vietnam) were explored in the dry season (March) and pre-rainy season (July) of 2019 and analyzed to evaluate their usage as bioindicators for ecological quality status of sediment. Nematode communities consisted of 23 genera belonging to 19 families, 8 orders for the dry and 24 genera, 17 families, 8 orders for the pre-rainy season. Several genera dominated in Tri An Reservoir such as Daptonema, Rhabdolaimus, Udonchus, and Neotobrilus indicated for organic enrichment conditions. The percentage of cp3 & 4 and MI (Maturity Index) value in the dry season was higher than that in the pre-rainy season expressed the ecological quality status of sediment in the dry season were better than those in the pre-rainy season. Furthermore, the result revealed that MI and c-p% composition can be used to evaluate the ecological quality status of sediment efficiently. Keywords: Bioindicator, ecological quality status of sediment, freshwater habitats, maturity index, nematodes, reservoir.
    Type of Medium: Online Resource
    ISSN: 2588-1140 , 2615-9317
    URL: Article
    DOI: 10.25073/2588-1140/vnunst.4973
    Language: Unknown
    Publisher: Vietnam National University Journal of Science
    Publication Date: 2020
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  • 7
    Online Resource
    Online Resource
    Effects of non-toxic filamentous cyanobacteria isolated from tri an reservoir on 〈i〉Daphnia〈/i〉
    Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications) ; 2020
    In:  Academia Journal of Biology Vol. 42, No. 3 ( 2020-08-26)
    Details
    In: Academia Journal of Biology, Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications), Vol. 42, No. 3 ( 2020-08-26)
    Abstract: This study is aimed to examine whether the presence of non-toxic filamentous cyanobacteria can cause toxic effects on Daphnia magna. Six strains of Oscillatoria perornata were isolated from the Tri An Reservoir and cultured in our laboratory for investigation. The results revealed that all strains were negative with the mcyA moleculer marker. The high performance liquid chromatography (HPLC) results showed that toxin was not detected in their culture products, indicating that these strains corresponded to non-toxin producing strains. However, the results of chronic assay indicated that these non-toxin producing O. perornata conferred toxic effects on the tested animals. The age at first reproduction of D. magna was delayed and the survival of D. manga decreased in proportional with the increase of the density of cells of O. perornata exposed. Significant differences in the life history responses were observed for D. mangna exposed to O. perornata. These results suggested that bioactive secondary metabolites other than microcystins produced by the filamentous cyanobacteria O. perornata may contribute to the toxic effects on Daphnia. Besides cyanotoxins, other secondary metabolites must be taken into account when investigating the toxic effects of cyanobacteria.   
    Type of Medium: Online Resource
    ISSN: 2615-9023 , 2615-9023
    URL: Article
    DOI: 10.15625/2615-9023/v42n3.13900
    Language: Unknown
    Publisher: Publishing House for Science and Technology, Vietnam Academy of Science and Technology (Publications)
    Publication Date: 2020
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  • 8
    Online Resource
    Online Resource
    The Interactive Effects of Natural Factor and Pollution Source on Surface Water Quality in the Lower Mekong River Basin, Southwestern Vietnam
    Pleiades Publishing Ltd ; 2020
    In:  Water Resources Vol. 47, No. 5 ( 2020-09), p. 865-876
    Details
    In: Water Resources, Pleiades Publishing Ltd, Vol. 47, No. 5 ( 2020-09), p. 865-876
    Type of Medium: Online Resource
    ISSN: 0097-8078 , 1608-344X
    URL: Article
    DOI: 10.1134/S0097807820050024
    Language: English
    Publisher: Pleiades Publishing Ltd
    Publication Date: 2020
    detail.hit.zdb_id: 2058341-2
    SSG: 14
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  • 9
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    Online Resource
    The habitat preferences of nematode assemblages in relation to the sediment granulometry in the Ba Lai estuary, Vietnam
    Elsevier BV ; 2022
    In:  Regional Studies in Marine Science Vol. 56 ( 2022-11), p. 102641-
    Details
    In: Regional Studies in Marine Science, Elsevier BV, Vol. 56 ( 2022-11), p. 102641-
    Type of Medium: Online Resource
    ISSN: 2352-4855
    URL: Article
    DOI: 10.1016/j.rsma.2022.102641
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2022
    detail.hit.zdb_id: 2835364-X
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  • 10
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    Online Resource
    A Comprehensive Study on Fish Species Composition, Diversity, Migration, Threatened Status, Economic Value and Endemism in the Co Chien River, Ben Tre Province (Mekong Delta), Vietnam
    Springer Science and Business Media LLC ; 2022
    In:  Ocean Science Journal Vol. 57, No. 1 ( 2022-03), p. 69-90
    Details
    In: Ocean Science Journal, Springer Science and Business Media LLC, Vol. 57, No. 1 ( 2022-03), p. 69-90
    Type of Medium: Online Resource
    ISSN: 1738-5261 , 2005-7172
    URL: Article
    DOI: 10.1007/s12601-021-00047-7
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 2219186-0
    detail.hit.zdb_id: 2198426-8
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