51 research outputs found
Camellia sinensis extract delays microbiological and oxidative changes in striped catfish fillets during frozen storage
peer reviewedThis study investigated the effects of tea leaf (Camellia sinensis) extract on the quality of striped catfish (Pangasianodon hypophthalmus) fillets during 18-months of frozen storage (-20 ± 2 °C). Fillet samples were submitted to the treatments Control (cold tap water), CS 7.63 (C. sinensis extract solution 7.63 µg/mL) and CS 625 (C. sinensis extract 625 µg/mL) and stored for 18 months, with collections performed at 0, 1, 3, 6, 9, 12 and 18 months. Total viable count, physicochemical parameters (water holding capacity, total volatile basic nitrogen, peroxide value, thiobarbituric acid reactive substances, moisture and pH), sensory properties and color measurement were evaluated. Results showed that fillets treated with C.a sinensis extracts slightly reduced lipid oxidation, inhibited bacterial growth and improved sensory properties compared to untreated samples, without causing significant changes in the other quality indicators. The findings indicated that the green tea leaf extract immersion treatments, contributed to the improved quality preservation of striped catfish fillets during frozen storage
ẢNH HƯỞNG CỦA MỘT SỐ YẾU TỐ ĐẾN QUÁ TRÌNH CHẾ TẠO NANO BẠC SỬ DỤNG DỊCH CHIẾT LÁ VỐI LÀM TÁC NHÂN KHỬ
In this study, we use the aqueous extract of Robusta plant leaves as a reducing agent and alginate as a surfactant to synthesize silver nanoparticles from silver nitrate (AgNO3). The influence of extraction time and the solid-liquid ratio, the concentration of AgNO3, the volume ratio between silver nitrate solution and the extract of Robusta leaves, and the reaction time on the synthesis were investigated. The optimal conditions are as follows: 15 g of leaves/200 mL, silver nitrate concentration 4 mM, Vextract/VAgNO3 4:100, 1% sodium alginate solution, and reaction time 45 minutes. The obtained solution of silver nanoparticles has a yellow-brown color. The TEM, XRD, and FT-IR measurements of the samples show that the silver nanoparticles have been successfully synthesized. The particles are spherical with an even size and 19.0-26.6 nm in diameter.Trong nghiên cứu này, chúng tôi trình bày phương pháp điều chế dung dịch nano bạc (Ag) từ bạc nitrate (AgNO3) sử dụng dịch chiết lá vối làm tác nhân khử và alginate là chất hoạt động bề mặt. Chúng tôi khảo sát ảnh hưởng của nồng độ AgNO3, tỷ lệ thể tích giữa AgNO3 và dịch chiết lá vối và thời gian phản ứng đến quá trình tạo nano Ag. Điều kiện tối ưu để tổng hợp nano Ag sử dụng dịch chiết lá vối gồm nồng độ AgNO3 4 mM, tỷ lệ thể tích Vdịch chiết /VAgNO3 = 4:100, nồng độ alginate 1%, thời gian phản ứng 45 phút tại nhiệt độ phòng. Dung dịch nano Ag thu được có màu vàng nâu đồng nhất. Kết quả đo TEM, SEM, XRD và FT-IR của các mẫu cho thấy nano Ag đã được tổng hợp thành công; hạt nano có dạng hình cầu, cấu trúc đồng đều với kích thước hạt khoảng 19,0–26,6 nm
XÂY DỰNG BỘ CHỈ TIÊU PHÁT TRIỂN BỀN VỮNG VỀ CÁC LĨNH VỰC KINH TẾ, XÃ HỘI VÀ MÔI TRƯỜNG CÁC TỈNH TÂY NGUYÊN
A sustainable development indication set plays a very important role for assessing, monitoring the sustainable development status in a region, supporting policy, decision makers to propose confident decisions to control economic, social, and environmental themes toward sustainable developmet. The content, procedure, methodology, and methods to establish the sustainable development indicator set in Tay Nguyen (SDI) were figured out; proposing a list of sustainable development indicators for Tay Nguyen consisting of 77 indicators at regional scale, 70 indicators at provincial scale, 49 indicators at district scale. The SDI could comprehensively show overall development process toward sustainable by 13 themes (economic field - 3 themes; social field - 5 themes; and environmental field - 5 themes). The paper outlined the SDI’s definition and indicated SDI’s significance through linkages between the sustainable development indicators and sustainable development themes.ReferencesLê Thạc Cán, Trần Thùy Chi, Nguyễn Thế Chinh, Nguyễn Viết Thịnh, Ngô Đăng Trí, Nguyễn Thanh Tuấn, Trần Văn Ý và James Hennessy, 2013. Kết quả bước đầu của Đề tài “Nghiên cứu xây dựng Bộ chỉ tiêu phát triển bền vững các lĩnh vực kinh tế xã hội và môi trường các tỉnh Tây Nguyên”, Tạp chí Khoa học Công nghệ Việt Nam, ISSN 1859-4794. No14, 2013, p 61-64. Dhakal S. 2002. Report on Indicator related research for Kitakyushu Initiative. Ministry of Environment, Japan. Harold A. Linstone, Murray Turoff, 2002. The Delphi Method: Techniques and Applications. Hui-Chun Chu, Gwo-Jen Hwang, 2008. A Delphi-based approach to developing expert systems with the cooperation of multiple experts, Expert Systems with Applications, 34(4), 2826- 840. (SCI). Jean Hugé, Hai Le Trinh, Pham Hoang Hai, Jan Kuilman and Luc Hens, 2009. Sustainability indicators for clean development mechanism projects in Vietnam, Springer Netherlands. Environment, Development and Sustainability, August 2010, Volume 12, Issue 4, pp 561-571. Trần Văn Ý, Lê Thạc Cán, Trần Thùy Chi, Nguyễn Thế Chinh, Ngô Đăng Trí, Nguyễn Viết Thịnh, Nguyễn Thanh Tuấn, 2013. Bộ chỉ tiêu phát triển bền vững về các lĩnh vực kinh tế, xã hội và môi trường các tỉnh Tây Nguyên. Kỷ yếu hội thảo quốc tế lần thứ tư, Việt Nam học, Nhà xuất bản Khoa học xã hội, Hà Nội, ngày 26-28/11/2012, tập IV, 386-400. Bộ Kế hoạch và Đầu tư, 2010. Hệ thống chỉ tiêu thống kê quốc gia (Ban hành theo Quyết định số 43/2010/QĐ/TTg ngày 02 tháng 6 năm 2010 của Thủ tướng Chính phủ). UNDP và MPI, 2005. Identification of a sustainable development indicators set and mechanism for building a sustainable development database in Vietnam (Project VIE/01/021 “Implementation of Vietnam Agenda 21”) United Nations, 2007. Indicators of Sustainable Development: Guidelines and Methodologies. Thủ tướng Chính phủ, 2012. Các chỉ tiêu giám sát và đánh giá phát triển bền vững Việt Nam giai đọan 2011-2020 (Ban hành kèm theo Quyết định số 432/QĐ-TTg ngày 12 tháng 4 năm 2012 của Thủ tướng Chính phủ). Thủ tướng Chính phủ, 2013. Bộ chỉ tiêu giám sát, đánh giá phát triển bền vững địa phương giai đoạn 2013-2020 (Ban hành kèm theo Quyết định số 2157/QĐ-TTg ngày 11 tháng 11 năm 2013 của Thủ tướng Chính phủ). A sustainable development indication set plays a very important role for assessing, monitoring the sustainable development status in a region, supporting policy, decision makers to propose confident decisions to control economic, social, and environmental themes toward sustainable developmet. The content, procedure, methodology, and methods to establish the sustainable development indicator set in Tay Nguyen (SDI) were figured out; proposing a list of sustainable development indicators for Tay Nguyen consisting of 77 indicators at regional scale, 70 indicators at provincial scale, 49 indicators at district scale. The SDI could comprehensively show overall development process toward sustainable by 13 themes (economic field - 3 themes; social field - 5 themes; and environmental field - 5 themes). The paper outlined the SDI’s definition and indicated SDI’s significance through linkages between the sustainable development indicators and sustainable development themes
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Clinical features, antimicrobial susceptibility patterns and genomics of bacteria causing neonatal sepsis in a children's hospital in Vietnam: protocol for a prospective observational study.
INTRODUCTION: The clinical syndrome of neonatal sepsis, comprising signs of infection, septic shock and organ dysfunction in infants ≤4 weeks of age, is a frequent sequel to bloodstream infection and mandates urgent antimicrobial therapy. Bacterial characterisation and antimicrobial susceptibility testing is vital for ensuring appropriate therapy, as high rates of antimicrobial resistance (AMR), especially in low-income and middle-income countries, may adversely affect outcome. Ho Chi Minh City (HCMC) in Vietnam is a rapidly expanding city in Southeast Asia with a current population of almost 8 million. There are limited contemporary data on the causes of neonatal sepsis in Vietnam, and we hypothesise that the emergence of multidrug resistant bacteria is an increasing problem for the appropriate management of sepsis cases. In this study, we aim to investigate the major causes of neonatal sepsis and assess disease outcomes by clinical features, antimicrobial susceptibility profiles and genome composition. METHOD AND ANALYSIS: We will conduct a prospective observational study to characterise the clinical and microbiological features of neonatal sepsis in a major children's hospital in HCMC. All bacteria isolated from blood subjected to whole genome sequencing. We will compare clinical variables and outcomes between different bacterial species, genome composition and AMR gene content. AMR gene content will be assessed and stratified by species, years and contributing hospital departments. Genome sequences will be analysed to investigate phylogenetic relationships. ETHICS AND DISSEMINATION: The study will be conducted in accordance with the principles of the Declaration of Helsinki and the International Council on Harmonization Guidelines for Good Clinical Practice. Ethics approval has been provided by the Oxford Tropical Research Ethics Committee 35-16 and Vietnam Children's Hospital 1 Ethics Committee 73/GCN/BVND1. The findings will be disseminated at international conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: ISRCTN69124914; Pre-results
An Outbreak of Severe Infections with Community-Acquired MRSA Carrying the Panton-Valentine Leukocidin Following Vaccination
Background: Infections with community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) are emerging
worldwide. We investigated an outbreak of severe CA-MRSA infections in children following out-patient vaccination.
Methods and Findings: We carried out a field investigation after adverse events following immunization (AEFI) were reported. We reviewed the clinical data from all cases. S. aureus recovered from skin infections and from nasal and throat swabs were analyzed by pulse-field gel electrophoresis, multi locus sequence typing, PCR and microarray. In May 2006, nine children presented with AEFI, ranging from fatal toxic shock syndrome, necrotizing soft tissue infection, purulent abscesses, to fever
with rash. All had received a vaccination injection in different health centres in one District of Ho Chi Minh City. Eight children had been vaccinated by the same health care worker (HCW). Deficiencies in vaccine quality, storage practices, or preparation and delivery were not found. Infection control practices were insufficient. CA-MRSA was cultured in four children and from nasal and throat swabs from the HCW. Strains from children and HCW were indistinguishable. All carried the Panton-Valentine leukocidine (PVL), the staphylococcal enterotoxin B gene, the gene complex for staphylococcal-cassette-chromosome mec type V, and were sequence type 59. Strain HCM3A is epidemiologically unrelated to a strain of ST59 prevalent in the USA, althoughthey belong to the same lineage.
Conclusions. We describe an outbreak of infections with CA-MRSA in children, transmitted by an asymptomatic colonized HCW during immunization injection. Consistent adherence to injection practice guidelines is needed to prevent CA-MRSA transmission in both in- and outpatient settings
Microplastic in atmospheric fallouts of a developing Southeast Asian megacity under tropical climate
International audienceMicroplastics in atmospheric fallouts from a developing megacity influenced by a tropical monsoon climate were investigated during a year. Three sites were selected according to the surrounding population density, the land use and occupation. The microplastic deposition fluxes varied between of 71–917 items m−2 d−1, for an observation size range of 300–5000 μm. Fibers predominated while fragments were observed occasionally. Unexpectedly, contrary to available scientific literature, deposition fluxes did not vary temporally with rainfall and wind intensity or direction, showing no effect of the tropical climate. Variations were observed between sites and were attributed to their environmental characteristics: population density and occupation space. The median length of fibers also differed between sites and could be related to in-situ fragmentation processes due to occupation space (solid waste treatment facility). Those first results from tropical climate region are showing interesting insights and are opening new perspectives on the understanding of microplastics fate from atmospheric fallouts
Baseline concentration of microplastics in surface water and sediment of the northern branches of the Mekong River Delta, Vietnam
International audienceThe Mekong River Delta in Vietnam, is conce rned by numerous micropl astic-related issues such as a lack of waste wate r tre atment facilities and mismanage ment of plastic waste released from agriculture, aquacult ure and related activities. This study ai med to examine the presence of microplastics in surface water and sedi ment by collecting samples from siX sites along the Tien River and its distributaries in February 2019. The results showed that the average concentration of microplastics over the entire area was 53.8 ± 140.7 items m-3 in surface water and 6.0 ± 2.0 items g-1 dried wei ght in sedi ment, wi th a pre domi nance of microplastic fibres rat he r t han fragments, respectively 85 % and 98 % in surface water and sediment. In t he main flow of surface wate r, t he concentration of microplastics was stable; however, in t he sedi ment, micropl astic concent ration was affected by the high dynamic flow regime rather than the sources where microplastics are released
Novel Approaches for Improving the Power Consumption Models in Correlation Analysis
Abstract. Differential Power Analysis (DPA) is a powerful technique for revealing secret data of cryptographic algorithms such as DES, AES and RSA implemented on a specific platform. In recent years, Correlation Power Analysis (CPA) allowed to better formalize the differential approaches of DPA with the use of a power model. We propose here two methods in order to optimize the power model for the targeted bits of the analysed algorithm. We will consider that all the targeted bits do not give the same contribution to the power consumption. Our first method consists in finding out the optimal ratio among the bits of a specific device. The second method is based on a statistical analysis of attack results while applying different possible ratios among the bits. The experimental electromagnetic radiation signals intercepted from an ASIC during DES operations show that our proposed methods allow to improve significantly the attack performance.
Baseline concentration of microplastics in surface water and sediment of the northern branches of the Mekong River Delta, Vietnam
International audienceThe Mekong River Delta in Vietnam, is conce rned by numerous micropl astic-related issues such as a lack of waste wate r tre atment facilities and mismanage ment of plastic waste released from agriculture, aquacult ure and related activities. This study ai med to examine the presence of microplastics in surface water and sedi ment by collecting samples from siX sites along the Tien River and its distributaries in February 2019. The results showed that the average concentration of microplastics over the entire area was 53.8 ± 140.7 items m-3 in surface water and 6.0 ± 2.0 items g-1 dried wei ght in sedi ment, wi th a pre domi nance of microplastic fibres rat he r t han fragments, respectively 85 % and 98 % in surface water and sediment. In t he main flow of surface wate r, t he concentration of microplastics was stable; however, in t he sedi ment, micropl astic concent ration was affected by the high dynamic flow regime rather than the sources where microplastics are released
Microplastic accumulation in oysters: Insights from aquaculture and laboratory conditions
International audienceMicroplastics, emerging pollutants, are present in seafood and pose a potential health risk to consumers. The objective of this study was to assess microplastic concentrations in the surface water, sediments, and oysters of the Cha Va River, an aquaculture production area in southern Vietnam. Laboratory experiments were also conducted to examine rates of ingestion by and bioconcentration of microplastics in oysters. Microparticles including microplastics were measured in all samples collected from the field, and presented 9-27 items m − 3 in surface water, 3300-8000 items kg − 1 dry weight in sediments, and 0.67-8.33 items ind − 1 or 0.02-0.33 items g − 1 wet weight in oysters. Fibre shapes and blue colour were the most common while polypropylene, polyester, polyethylene, and polyethylene terephthalate acrylate, alkyd were identified. The presence of microparticles in surface water and sediment was influenced by the complex vertical motion characteristic of tidal environments whereas the microparticles in natural oysters seemed to be closer related to those in sediment than in the surface water. Laboratory experiments showed that oysters incubated in 10 and 1000 microplastics L − 1 tanks accumulated 4.1 ± 2.0 and 19.0 ± 11.0 microplastics per individual, respectively. However, bioconcentration of microplastics in oysters was higher (12.37 ± 6.95) in tanks with lower microplastic concentrations than in tanks with higher microplastic concentrations (0.62 ± 0.35). It is a high potential human health risk to the local oysterconsumers because of the annually microparticle ingestion from 657 to 3942 items per person. We suggested further studies on the severity of this potential health risk and policies for minimising microplastic emissions into the environment in Vietnam
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