ISOLATION AND SELECTION OF LIPASE-PRODUCING BACTERIA IN VIETNAM

Joint Research on Environmental Science and Technology for the Eart

An investigation of the academic consulting competence of high school teachers in Vietnam

High school students must grapple with a host of issues and encounter difficulties when studying at schools, such as peer pressure, test anxiety, cyberbullying, unhealthy relationships, psychological distress, depression and possibly domestic issues. These obstacles create the need for academic consulting in order for high school students to develop essential skills and then solve problems. This study aims to examine the high school teachers' perceptions and the quality of academic consulting competence in the Vietnamese educational context. This study surveyed 1089 high school students and 289 teachers in Ha Noi and Ho Chi Minh City in Vietnam with the 43-item questionnaire. The main results showed that academic consulting competence had been noticed and trained professionally for high school teachers. Additionally, both students and high school teachers recognized the essential role of high school teachers' academic consulting competence in educational settings

Microbial diversity in trace water of jet fuel in Vietnam

Joint Research on Environmental Science and Technology for the Eart

DIVERSITY OF MICROORGANISMS IN SOME FAMOUS BAYS OF VIETNAM AND THEIR ABILITY TO USE IN AQUACULTURE

Joint Research on Environmental Science and Technology for the Eart

DISTRIBUTION OF USEFUL AND HARMFUL MICROORGANISMS IN SHRIMP AQUACULTURE WATER IN TIEN HAI COASTAL OF THAI BINH PROVINCE

Joint Research on Environmental Science and Technology for the Eart

Using of response surface methodology for optimization of biohydrogen production by Clostridium sp. tr2 isolated in Vietnam

Biohydrogen is a clean, renewable, sustainable energy resource due to the highest energy density among all fuels and its combustion has no contribution to the environmental pollution and climate change. Biohydrogen production depends on a number of nutritional and environmental variables. The present paper is to determine the optimum condition for enhanced hydrogen production by a fermentative hydrogen-producing bacterium (designated as Clostridium sp. Tr2) isolated from buffalo-dung in Vietnam. The response surface methodology (RSM) was employed to determine the mutual effects of glucose, yeast extract and iron concentration on its hydrogen production in a batch condition. RSM analysis showed that the highest hydrogen production potential (Ps) was obtained under the condition of 10.18 g L-1 glucose, 2.5 g L-1 yeast extract and 58 mg L-1 FeSO4.7H2O. All three factors had significant influences on the Ps. Glucose and iron concentration, yeast extract and iron concentration were interdependent or there was a significant interaction on Ps. Glucose and yeast extract concentration was slightly interdependent, or their interactive effect on Ps was not significant. Under optimum conditions, the maximum H2 volume of 1080 ml (L medium)-1 were found after 22 h facultative anaerobic fermentation. The experiment results show that the RSM analysis with the central composite design was useful for optimizing the biohydrogen-producing process by newly isolated Clostridium sp. Tr2 in Vietnam

Genetic characterization of an H5N1 avian influenza virus from a vaccinated duck flock in Vietnam

This study reports the genetic characterization of a highly pathogenic avian influenza virus subtype H5N1 isolated from a moribund domestic duck in central Vietnam during 2012. In the moribund duck’s flock, within 6 days after vaccination with a commercial H5N1 vaccine (Re-5) to 59-day-old birds, 120 out of 2,000 ducks died. Genetic analysis revealed a substantial number of mutations in the HA gene of the isolate in comparison with the vaccine strains, Re-1 and Re-5. Similar mutations were also found in selected Vietnamese H5N1 strains isolated since 2009. Mutations in the HA gene involved positions at antigenic sites associated with antibody binding and also neutralizing epitopes, with some of the mutations resulting in the modification of N-linked glycosylation of the HA. Those mutations may be related to the escape of virus from antibody binding and the infection of poultry, interpretations which may be confirmed through a reverse genetics approach. The virus also carried an amino acid substitution in the M2, which conferred a reduced susceptibility to amantadine, but no neuraminidase inhibitor resistance markers were found in the viral NA gene. Additional information including vaccination history in the farm and the surrounding area is needed to fully understand the background of this outbreak. Such understanding and expanded monitoring of the H5N1 influenza viruses circulating in Vietnam is an urgent need to provide updated information to improve effective vaccine strain selection and vaccination protocols, aiding disease control, and biosecurity to prevent H5N1 infection in both poultry and humans.Japan Society for the Promotion of Science. Grant-in-Aid for the Bilateral Joint ProjectsHeiwa Nakajima FoundationNational Institute of Allergy and Infectious Diseases (U.S.) (Contract HHSN2662007000010C

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

Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions

Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke