66 research outputs found

    Synthesis of ZnO nanorod for immunosensor application

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    This paper reported a facile method to synthesize ZnO nanorods for immunosensor application. The ZnO nanorods were synthesized by hydrothermal reaction. Synthesis time affecting on morphology of nanorods was also studied. The immobilization of anti-rotavirus onto ZnO nanorod-deposited sensor was performed via absorption method. The electrochemical responses of the immunosensor were studied by cyclic voltammetry (C-V) method with [Fe(CN)6]3−/4− as redox probe. A linear decreased response in C-V for cell of rotavirus concentration was found in the range of 7.8×105 CFU/mL to 7.8×108 CFU/mL. The detection limit of the immunosensor was 7.8×105 CFU/mL. The results indicated application of ZnO nanorod sensor for label-free real-time detection of a wide dynamics range of biological species

    Graptolites from Silurian (Llandovery Series) sedimentary deposits attributed to a forearc setting, Co To Formation, Co To archipelago, northeast Vietnam

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    Newly collected graptolites from the Co To Formation, Co To archipelago, NE Vietnam, comprise assemblages indicative of two biostratigraphical levels within the lower Silurian, Llandovery Series, Telychian Stage: the co-occurrence of Spirograptus turriculatus and Torquigraptus proteus? suggests an interval most likely within the upper part of the Spirograptus turriculatus Biozone or 'Monograptus' crispus Biozone, whilst Oktavites spirally and Monoclimacis cf. suhgeinitzi identify the Oktavites spiralis Biozone. The graptolites provide important biostratigraphical evidence for the age of the upper part of the lower Co To Formation, biostratigraphical ties between the NE Vietnamese succession of the Bac Bo Region and graptolite assemblages of the Long Dai Formation in the Viet-Lao Region of central Vietnam, and include the new species Monograptus hanutlus sp. nov. co-occurring with S. turriculatus, which is perhaps an ancestral form to the later Telychian species Monograptus drepanoformis. We also report the lirst chitinozoans, including Belonechitina, from the Co To Formation

    Uptake capacity of metals (Al, Cu, Pb, Sn, Zn) by Vetiveria Zizanioides in contaminated water in the Dong Xam metal production trade village, Thai Binh, Vietnam

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    This study presents an experiment of metal contaminated water treatment under controlled environment conditions to investigate the uptake capacity of metals by Vetiveria Zizanioides to treat contaminated water from a metal production trade village, Dong Xam, Thai Binh, Vietnam. Vetiver was grown in two pot culture experiments TB10, TB6 with solutions containing respective concentrations of Al, Cu, Pb, Sn and Zn of 2.5, 55.6, 0.15, 7.7 and 24.4 mg from contaminated water in the Dong Xam metal production trade village for a period of 36 days. Vetiver has the higher tolerance to Al, Cu, Pb, Sn and Zn than other plant species. The roots (hereafter R) are high Al hyperaccumulators, concentrating 17 up to 30 folds more than “reference plant”. The upper parts of shoots (hereafter S1, S2, and S3) are 1.2 folds higher. Cu concentration in the root and shoot is up to 660 and 46.2 mg/kg, respectively. Vetiver can withstand and survive at Cu concentration of 46 mg/L in contaminated water that is markedly higher than other plants that can last only in solution with Cu concentration ranging 20-100 mg/kg. The translocation of Pb from root to shoot was 41%. Sn is more accumulated in the top, in which shoot/root ratio varied from 82% to 277% in the top, and increased to the top (by order S3/RS2/RS1/R). Zn could be translocated from roots and accumulated in shoots of vetiver. The ratio shoot/root obtains up to 46%. The present results demonstrated that vetiver had the high tolerance to trace metals Al, Cu, Pb, Sn and Zn in vegetation. This plant has a potential phytoremediation of metals in contaminated soil and wastewater from trade villages of Vietnam and other countries.References Adriano D.C., 1992. Biochemistry of trace metals. Lewis Publishers. Boca Raton, New York. 513 pp. Baker D.E., 1976. Acid soils. In Proc. of Workshop on Plant Adaptation to Mineral Stress in Problem Soils. 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    Pro-poor intervention strategies in irrigated agriculture in Asia: poverty in irrigated agriculture: issues and options: Vietnam

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    Irrigated farming / Poverty / Farm income / Irrigation management / Institutions / Legal aspects / Water rates / User charges / Participatory management / Privatization / Participatory rural appraisal / Performance indexes / Irrigation programs / Irrigation systems / Pumping / Irrigation canals / Social aspects / Economic aspects / Rivers / Hydrology / Dams / Households / Income / Regression analysis / Drainage / Cooperatives / Water delivery / Water distribution / Rice / Financing / Drought / Vietnam / Red River Delta / Nam Duong Irrigation System / Nam Thach Han Irrigation System / Han River

    BioCaster: detecting public health rumors with a Web-based text mining system

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    Summary: BioCaster is an ontology-based text mining system for detecting and tracking the distribution of infectious disease outbreaks from linguistic signals on the Web. The system continuously analyzes documents reported from over 1700 RSS feeds, classifies them for topical relevance and plots them onto a Google map using geocoded information. The background knowledge for bridging the gap between Layman's terms and formal-coding systems is contained in the freely available BioCaster ontology which includes information in eight languages focused on the epidemiological role of pathogens as well as geographical locations with their latitudes/longitudes. The system consists of four main stages: topic classification, named entity recognition (NER), disease/location detection and event recognition. Higher order event analysis is used to detect more precisely specified warning signals that can then be notified to registered users via email alerts. Evaluation of the system for topic recognition and entity identification is conducted on a gold standard corpus of annotated news articles

    Extreme temperature impairs growth and productivity in a common tropical marine copepod

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    Abstract Shallow, tropical marine ecosystems provide essential ecosystem goods and services, but it is unknown how these ecosystems will respond to the increased exposure to the temperature extremes that are likely to become more common as climate change progresses. To address this issue, we tracked the fitness and productivity of a key zooplankton species, the copepod Pseudodiaptomus annandalei, acclimated at two temperatures (30 and 34 °C) over three generations. 30 °C is the mean temperature in the shallow water of the coastal regions in Southeast Asia, while 34 °C simulated a temperature extreme that occurs frequently during the summer period. For each generation, we measured the size at maturity and reproductive success of individuals. In all three generations, we found strong negative effects of warming on all measured fitness-related parameters, including prolonged development time, reduced size at maturity, smaller clutch sizes, lower hatching success, and reduced naupliar production. Our results suggest that P. annandalei are already exposed to temperatures that exceed their upper thermal optimum. Increased exposure to extreme temperatures may reduce the abundance of these tropical marine copepods, and thus reduce the availability of resources to higher trophic levels

    Seroepidemiology and Carriage of Diphtheria in Epidemic-Prone Area and Implications for Vaccination Policy, Vietnam

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    In 2019, a community-based, cross-sectional carriage survey and a seroprevalence survey of 1,216 persons 1–55 years of age were conducted in rural Vietnam to investigate the mechanism of diphtheria outbreaks. Seroprevalence was further compared with that of an urban area that had no cases reported for the past decade. Carriage prevalence was 1.4%. The highest prevalence, 4.5%, was observed for children 1–5 years of age. Twenty-seven asymptomatic Coerynebacterium diphtheriae carriers were identified; 9 carriers had tox gene–bearing strains, and 3 had nontoxigenic tox gene–bearing strains. Child malnutrition was associated with low levels of diphtheria toxoid IgG, which might have subsequently increased child carriage prevalence. Different immunity patterns in the 2 populations suggested that the low immunity among children caused by low vaccination coverage increased transmission, resulting in symptomatic infections at school-going age, when vaccine-induced immunity waned most. A school-entry booster dose and improved infant vaccination coverage are recommended to control transmissions

    Mapping inequalities in exclusive breastfeeding in low- and middle-income countries, 2000–2018

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    Exclusive breastfeeding (EBF)—giving infants only breast-milk for the first 6 months of life—is a component of optimal breastfeeding practices effective in preventing child morbidity and mortality. EBF practices are known to vary by population and comparable subnational estimates of prevalence and progress across low- and middle-income countries (LMICs) are required for planning policy and interventions. Here we present a geospatial analysis of EBF prevalence estimates from 2000 to 2018 across 94 LMICs mapped to policy-relevant administrative units (for example, districts), quantify subnational inequalities and their changes over time, and estimate probabilities of meeting the World Health Organization’s Global Nutrition Target (WHO GNT) of ≥70% EBF prevalence by 2030. While six LMICs are projected to meet the WHO GNT of ≥70% EBF prevalence at a national scale, only three are predicted to meet the target in all their district-level units by 2030

    Taxonomy and diversity of coelobite bryozoans from drift coral cobbles on Co To Island, northern Vietnam

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    Dick, Matthew H., Ngai, Nguyen Danh, Doan, Hung Dinh (2020): Taxonomy and diversity of coelobite bryozoans from drift coral cobbles on Co To Island, northern Vietnam. Zootaxa 4747 (2): 201-252, DOI: 10.11646/zootaxa.4747.2.
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