46 research outputs found
A TAXONOMIC KEY FOR YELLOW CAMELLIAS IN THE CENTRAL HIGHLANDS OF VIETNAM
Eighteen yellow Camellia species are found in the Central Highlands of Vietnam. Their morphological characteristics are described and illustrated. Based on the morphological characteristics of the leaves, flowers, and fruit, a dichotomous key has been constructed
ヴェトナムのインフラ事業におけるPPPスキームの発展過程
学位の種別: 課程博士審査委員会委員 : (主査)東京大学教授 小澤 一雅, 東京大学教授 元橋 一之, 東京大学教授 堀田 昌英, 東京大学教授 加藤 浩徳, 東京大学准教授 清家 剛University of Tokyo(東京大学
GENETIC DIVERSITY IN THE NATURAL POPULARIONS OF Pinus dalatensis Ferre’ (PINACEAE) ASSESSED BY SSSR MARKERS
Pinus dalatensis Ferre’(Family: Pinaceae) is an endemic plant with restricted habitats at higher altitudes in Vietnam highland. The species are now near threatened by over-exploitation and habitat destruction. The genetic variation within and among populations of P. dalatensis was investigated by 41 microsatellite (single sequence repeat, SSR) primers, but only 11 SSR primers showed polymorphism bands. In all, 70 sampled trees from six populations in Vietnam highland were analyzed in this study, samples were collected from populations located in different altitude. A total of 40 allelic variants have been detected. The mean number of alleles per locus was 2.197. The SSR data showed a genetic diversity parameters within populations with an average of I = 0.524, Ho = 0.222, He = 0.317, Fis =0.333 and Ap = 0.106. The number private alleles (Ap) was only found in four populations, the Hoa Son population showed the highest (0.273), followed by Da Chay (0.182), and value of 0.091 for all Ngoc Linh and A Yun. Analysis of molecular variance analysis showed that most genetic variation was within populations of 57.504 % and among population of 42.496 %. The population pairwise differentiations indicated that most of the populations were significantly differentiated p 0.001 with Fst values ranged from 0.195 to 0.418. This study highlights the importance of conserving the genetic resources of P. dalatensis specie
STUDY ON THE EFFECT OF CALCIUM-ALGINATE AND WHEY PROTEIN ON THE SURVIVAL RATE OF Bifidobacterium bifidum IN MAYONNAISE
ABSTRACT – QMFS 2019The functional food development by adding probiotic bacteria is getting a lot of concern. In this study, Bifidobacterium bifidum AS 1.1886 was encapsulated in calcium-alginate 2% w/v (C sample) or the mix of calcium-alginate 2% (w/v) and whey protein 1% (w/v) (CW sample) or calcium-alginate 2% (w/v) coated by whey protein 1% (w/v) (CcW sample) by extrusion method, and added to mayonnaise product. The pH changes, the survival rate of probiotic bacteria, and total yeast and mold count during storage, as well as the probiotic survival in simulated gastric medium, were evaluated. The result showed that the pH changes were not significantly different in all mayonnaise samples in this test. The viability of the free probiotic cell was significant decrease about 5.85 log CFU/g compared to 0.26 ÷ 1.14 log CFU/g in encapsulated cell samples after four weeks of storage. None of the free cells survived after six weeks of storage. The total yeast and mold count in samples related to the probiotic count, the viability of probiotic cells higher 6 log CFU/g might be controlling the growth of yeast and molds in mayonnaise. Whey protein has been shown to significantly improve the survival rate of B.bifidum and calcium-alginate coated by whey protein, indicating the most effective protection. The result showed that the application potential of encapsulated probiotic in mayonnaise product
Biocompatible chitosan-functionalized upconverting nanocomposites
Simultaneous integration of photon emission and biocompatibility into nanoparticles is an interesting strategy to develop applications of advanced optical materials. In this work, we present the synthesis of biocompatible optical nanocomposites from the combination of near-infrared luminescent lanthanide nanoparticles and water-soluble chitosan. NaYF4:Yb,Er upconverting nanocrystal guests and water-soluble chitosan hosts are prepared and integrated together into biofunctional optical composites. The control of aqueous dissolution, gelation, assembly, and drying of NaYF4:Yb,Er nanocolloids and chitosan liquids allowed us to design novel optical structures of spongelike aerogels and beadlike microspheres. Well-defined shape and near-infrared response lead upconverting nanocrystals to serve as photon converters to couple with plasmonic gold (Au) nanoparticles. Biocompatible chitosan-stabilized Au/NaYF4:Yb,Er nanocomposites are prepared to show their potential use in biomedicine as we find them exhibiting a half-maximal effective concentration (EC50) of 0.58 mg mL–1 for chitosan-stabilized Au/NaYF4:Yb,Er nanorods versus 0.24 mg mL–1 for chitosan-stabilized NaYF4:Yb,Er after 24 h. As a result of their low cytotoxicity and upconverting response, these novel materials hold promise to be interesting for biomedicine, analytical sensing, and other applications
CONTAMINATION BY PERSISTENT ORGANIC POLLUTANTS AND ENDOCRINE DISRUPTING CHEMICALS IN VIETNAM : PATTERNS, BEHAVIOR, TRENDS AND TOXIC POTENTIAL
Joint Research on Environmental Science and Technology for the Eart
Persistent organochlorines in environment of coastal area, a case study in Vietnam
Abstracts of 2nd UNU-ORI joint international workshop for marine environment第2回海洋環境国際ワークショップ講演要
Widespread contamination by persistent toxic substances in Vietnam and their implications on environmental quality and human health
Vietnam is a developing country located in the central part of the Southeast Asian tropical region. The country comprises the Red River and Mekong River Delta, inhabiting more than 30 million people, which is one of the most populous areas in the world. These deltas have become one of the most productive agricultural regions in Southeast Asia. Agrochemicals have been used extensively in the past and until very recently for agricultural purposes and malaria eradication program. The present paper provides a comprehensive overview of the environmental distribution, patterns and trends of contamination of toxic substances including persistent organochlorines (OCs) and endocrine active compounds (EACs) in different environmental compartments from Vietnam. Monitoring data reported during the 1990s demonstrated widespread and elevated contamination of DDTs in air, water, sediments and soils from in Vietnam. Recent studies in frame of the Asia-Pacific Mussel Watch Program have also revealed that fish, mussels and resident birds from Vietnam contained higher concentrations of DDTs as compared to other countries in region, suggesting the role of Vietnamese environment as a significant emission source of DDT in the Southeast Asian region. Subsequent surveys on coastal lines from north and middle part of Vietnam likewise demonstrated that contamination of some endocrine active compounds such as alkylphenols and phthalates are ubiquitous. In particular, relatively high concentrations of bis-phenol A were found in some locations in Red River delta, comparable or higher than those reported for several locations in developed nations in Western Europe and North America. A case study on seasonal variation of alkylphenols and phthalates in surface water of river delta and estuary of north and central Vietnam indicated the differences in distribution of these compounds between dry and rainy seasons. Higher concentrations of alkylphenols and phthalates were found in dry season in estuary; while the contrasting pattern was observed in the river delta, showing elevated residues in rainy season. This result suggests the different behavior of alkylphenols and phthalates in river delta and in coastal environment. The temperature dependence in tropical ecosystem and the influence of the specific local sources may be reasons for the observed results in the seasonal variations. To our knowledge, this is the first extensive study on the widespread contamination of EACs in Vietnam. Regarding the trends of contamination by OCs, preliminary survey conducted in Read River delta water and sediments indicated a rapid decline trend in water and a slow decrease in sediments during 1995-2001. From ecotoxicological and human health perspectives, concentrations of bis-phenol A and di (2-ethylhexyl) phthalates in surface water from some locations in Vietnam exceeded the guideline values for Ecotoxicological Effects and the Environmental Risk Limit, respectively, suggesting potential for toxic implications on aquatic wildlife. Human exposure to persistent organic pollutants indicated that DDT residues levels in human breast milk from both Hanoi and Hochiminh city were among the highest values reported for Asian developing countries as well as developed nations. Daily intakes estimating based on the exposure through sea-foods indicates that intakes of DDTs by Vietnamese populations were among the highest rank in Asia-Pacific countries, suggesting potential risk for human exposure to elevated DDT pollution. Future studies should be focused on the time trends of POPs and EACs in biota of Vietnam with view of predicting the future trend of contamination and to reveal new clues for understanding possible toxic impacts on aquatic organisms
Widespread contamination by persistent toxic substances in Vietnam and their implications on environmental quality and human health
Vietnam is a developing country located in the central part of the Southeast Asian tropical region. The country comprises the Red River and Mekong River Delta, inhabiting more than 30 million people, which is one of the most populous areas in the world. These deltas have become one of the most productive agricultural regions in Southeast Asia. Agrochemicals have been used extensively in the past and until very recently for agricultural purposes and malaria eradication program. The present paper provides a comprehensive overview of the environmental distribution, patterns and trends of contamination of toxic substances including persistent organochlorines (OCs) and endocrine active compounds (EACs) in different environmental compartments from Vietnam. Monitoring data reported during the 1990s demonstrated widespread and elevated contamination of DDTs in air, water, sediments and soils from in Vietnam. Recent studies in frame of the Asia-Pacific Mussel Watch Program have also revealed that fish, mussels and resident birds from Vietnam contained higher concentrations of DDTs as compared to other countries in region, suggesting the role of Vietnamese environment as a significant emission source of DDT in the Southeast Asian region. Subsequent surveys on coastal lines from north and middle part of Vietnam likewise demonstrated that contamination of some endocrine active compounds such as alkylphenols and phthalates are ubiquitous. In particular, relatively high concentrations of bis-phenol A were found in some locations in Red River delta, comparable or higher than those reported for several locations in developed nations in Western Europe and North America. A case study on seasonal variation of alkylphenols and phthalates in surface water of river delta and estuary of north and central Vietnam indicated the differences in distribution of these compounds between dry and rainy seasons. Higher concentrations of alkylphenols and phthalates were found in dry season in estuary; while the contrasting pattern was observed in the river delta, showing elevated residues in rainy season. This result suggests the different behavior of alkylphenols and phthalates in river delta and in coastal environment. The temperature dependence in tropical ecosystem and the influence of the specific local sources may be reasons for the observed results in the seasonal variations. To our knowledge, this is the first extensive study on the widespread contamination of EACs in Vietnam. Regarding the trends of contamination by OCs, preliminary survey conducted in Read River delta water and sediments indicated a rapid decline trend in water and a slow decrease in sediments during 1995-2001. From ecotoxicological and human health perspectives, concentrations of bis-phenol A and di (2-ethylhexyl) phthalates in surface water from some locations in Vietnam exceeded the guideline values for Ecotoxicological Effects and the Environmental Risk Limit, respectively, suggesting potential for toxic implications on aquatic wildlife. Human exposure to persistent organic pollutants indicated that DDT residues levels in human breast milk from both Hanoi and Hochiminh city were among the highest values reported for Asian developing countries as well as developed nations. Daily intakes estimating based on the exposure through sea-foods indicates that intakes of DDTs by Vietnamese populations were among the highest rank in Asia-Pacific countries, suggesting potential risk for human exposure to elevated DDT pollution. Future studies should be focused on the time trends of POPs and EACs in biota of Vietnam with view of predicting the future trend of contamination and to reveal new clues for understanding possible toxic impacts on aquatic organisms
Blood pressure percentiles and systemic hypertension-associated factors among children aged between 6 and 15 years in Southern Vietnam
Background: The present study determined blood pressure percentiles in children aged between 6 and 15 years in Southern Vietnam.
Material and methods: Blood pressure was measured in a random sample of 1080 students aged 6–15 years who was studying at primary and secondary high schools in My Tho city, Vietnam. A descriptive cross-sectional study was conducted from November 2019 to June 2020. To diagnose children systemic hypertension, the blood pressure must be above the 95th percentile. Data were analyzed by IBM SPSS statistics software version 20.0. The Chi-squared test was employed to evaluate the relationship between systemic hypertension and child demographic characteristics including gender and obesity.
Results: The results showed that the 95th percentiles of systolic and diastolic blood pressure of the children was 110/70 mm Hg in the 6-year-old group, 120/75 mm Hg in the 7 to12-year-old group and 125/80 mm Hg in the 13 to 15-year-old group, respectively. The rate of systemic hypertension in the children was 10% whereas boys had a 1.2 time higher risk of systemic hypertension than girls (p > 0.05). Obese children had an 8.6 time higher risk of systemic hypertension than non-obese ones (p < 0.001).
Conclusion: The blood pressure percentile chart of school children aged 6–15 years were reported here for the first time in Vietnam. The results provided useful information in early diagnosis and timely treatment of systemic hypertension in children