Health impact of exposure to arsenic-contaminated drinking water in Vietnam

The public health situation of the population of Hanam Province in Vietnam is of great concern, as it is exposed daily to arsenic-contaminated drinking water. Optimising arsenic (As) removal efficiency of current sand filters at household level or switching to cleaner or As-free water sources is crucial to prevent or reduce community health risks

Investigation of the estrogenic activity of Pueraria candollei variety mirifica extract on rats

Background: Pueraria candollei variety mirifica (PM) has been widely used as ingredient in many rejuvenating products. In this study, we aimed to assess the estrogenic activity of PM extract grown in Vietnam.Methods: Estrogenic activity of PM extract was estimated on immature female rats by using uterotrophic method to measure the weight of the reproductive organs. Estrogenic activity of PM extract also was investigated in mature female ovariectomized rats by evaluating the vaginal cells growth, reproductive organs weight, serum estradiol concentration.Results: Our results showed that PM extract at doses of 100 mg/kg, 200 mg/kg had increased the reproductive organs weight in immature rats and female ovariectomized rats. In addition, PM extract had increased the serum estradiol concentration and the vaginal cells growth by increasing the percentage of keratinocytes in female ovariectomized rats.Conclusions: Our results showed that PM extract has strong estrogenic activity in rats

Invited review. Natural rubber nanocomposites.

Natural rubber (NR) is a valuable and important polymer material that has wide and various applications. Therefore the investigations for NR improvement, particularly for special applications are in continuous development. In this trend, preparation of NR nanocomposites using nanofillers of both organic and inorganic origination is one of leading directions. In this paper, NR nanocomposites with the most popular and promising nanofillers were reviewed. These nanofillers are nanosilica and layered silicate as the most important fillers for NR industry after carbon black, and nanocellulose as a new abundant and environmental friendly filler. Methods of NR nanocomposites preparation were briefly summarized. The main attention was paid to the establishment of nanostructures in NR composites. Based on limited (about 80) references, mostly in recent 15 years, the improvement of NR nanocomposite properties was analyzed in connection with their nanostructure. Keywords. Natural rubber, nanocellulose, nanosilica, nanoclay, nanocomposite

Dynamic response analysis of truss bridges under the effect of moving vehicles

With the characteristics of heavy and concentrated loads, the influence of moving loads on the dynamic response of the bridges is significant. Therefore, in this paper, the dynamic response of a large-scale truss bridge is studied to consider the effect of the various parameters of moving loads. The considered main parameters consist of moving mass, moving velocity, and type of moving loads. The nonlinear dynamics of the bridge based on time history analysis are obtained using the Wilson-  method. four time history – based dynamic analysis method including modal superposition in frequency domain, modal superposition in time domain; direct time integration, and direct solution in the frequency domain are employed to analysis the obtained results. To compare the effectiveness of the aforementioned method. A large-scale railway truss bridge is employed for dynamic response analysis. The obtained results give more insight into the nature of the problem and help to determine the significant parameters of moving load affecting the bridge response

Assessment of impacts of utilization on water resources in the basin of trans-boundary Red river system

The Red river system is the large trans-boundary river system, there has been no united system of hydrology stations as well as integrated plan for the water use and management in the whole basin. The trend of water resources change in the Red river system basin has been assessed on the basic of statistic analyses of data observed during the studies, especially in the time when the exploitation of water resources has been intensified for the multisectoral development. This paper shows some of the results from considerations of the water use in the highlands that is influential in water resources in the Red river system basin and the planned reservoirs which are built in the basin of Red river system. The results include the assessment of the state and trend of water resources in the Red river system basin, the trend of water level lowering in the lowlands and its impacts

Study on spatial distribution of coral reefs in Nam Yet island by using GIS and remote sensing techniques

Research and application of GIS and remote sensing techniques combined with field survey in coastal areas of Nam Yet island had been carried out to establish the distribution map of submarine habitats. Depth-invariant index was used to correct water column’s effects on spectral reflectance of each habitat. The results of satellite image classification showed that area with well-developed coral at great depths accounted for 12%, area with well-developed coral at small depths accounted for 9%, area with poorly-developed coral accounted for 13%, dead coral area accounted for 15% and area of sand, grit, pebbles and weathered coral accounted for 51%. The assessment after classification showed that the overall accuracy of the satellite image interpretation process was 94% and the kappa coefficient was 0.93

HỢP TÁC VIỆT - NGA TRONG CHẾ TẠO VÀ THỬ NGHIỆM MÁY THĂM DÒ ĐIỆN TỔ HỢP TEC-2 PHỤC VỤ KHẢO SÁT MÔI TRƯỜNG ĐỊA CHẤT TẦNG NÔNG

The geophysical investigation system named TEC-2 (Tomography Electric Complex-2) was designed, installed and tested in Institute of Marine Geology and Geophysics. This TEC-2 is the scientific cooperation product of Geomagnetic and Geoelectric Department of and POI and Geo - environmental Department of IMGG-VAST. The test results using TEC-2 show the capability of investigating by using certain pole system, short investigation time, high stability, the accuracy of two investigation times being more than 92%. The distributed design of electric poles, measuring operation, parameter selection, … are programmed and controlled automatically by computer. The TEC-2 system was used for investigating the weak structures in islands of Song Tu Tay, Son Ca, Nam Yet and Sinh Ton in Truong Sa Archipelagos and shallow geological environment in the area of Red River bank in Son Tay Hanoi. The acquired data  contributed to the success of the scientific projects managed by IMGG in the National Program of Bien Dong and islands in the period of 2011 - 2013 and VAST’s research project in the period of 2013 - 2014.Máy đo điện tổ hợp TEC-2 (Tomography Electric Complex-2)  được thiết kế, lắp ráp và thử nghiệm tại Viện Địa chất và Địa vật lý biển là sản phẩm hợp tác khoa học giữa phòng Địa từ điện của Viện Hàn lâm Khoa học Nga chi nhánh Viễn Đông (POI) và phòng Địa môi trường thuộc Viện Địa chất và Địa vật lý biển (IMGG). Kết quả đo thử nghiệm máy TEC-2 cho thấy khả năng đo tổ hợp nhiều phương pháp trên hệ điện cực bố trí sẵn, thời gian đo nhanh, độ ổn định của kết quả đo cao, độ chính xác giữa hai lần đo đạt trên 92%. Các thiết kế hệ điện cực, thao tác đo, chọn tham số được lập trình và điều khiển tự động bằng máy tính. Máy TEC-2 đã được sử dụng để nghiên cứu các đới cấu trúc yếu thuộc các đảo san hô Song Tử Tây, Cơn Ca, Nam Yết và Sinh Tồn thuộc quần đảo Trường Sa và môi trường địa chất tầng nông khu vực ven bờ Sông Hồng khu vực Sơn Tây Hà Nội. Các kết quả thu thập được đã đóng góp một phần quan trọng cho sự thành công của đề tài nghiên cứu do Viện Địa chất và Địa Vật lý biển chủ trì thuộc Chương trình Biển Đông và Hải đảo giai đoạn 2011 - 2013 và đề tài cấp Viện Hàn lâm Khoa học và Công nghệ Việt Nam giai đoạn 2013 - 2014

Research on marine environment and coral distribution on Nam Yet island using VNRedsat-1 and QuickBird images

Based on the processing of VNRedsat-1 and QuickBird images in the area of Truong Sa archipelago, the research results showed the efficiency of assessing marine environmental characteristics in surroundings of these islands. In this paper, we presented the research results on Nam Yet island and adjacent area. The marine parameters in this research include sea surface temperature (SST) and chlorophyll-a concentration in the surface layer as well as in the deep layers of 20m and 40m, the distributions of the ground objects such as coral shelf, sand accumulation, coral reef combined with seagrass and seaweed. The accuracy of assessment of supervised and unsupervised classified results is approximate of 87.8%. The research results allowed assessing the environmental characteristics, warning of the risk of erosion and coastal line change in the study area

Application of satellite images and VNREDSAT-1 images in study on marine environment in Truong Sa region

The remote sensing images, including images of MODIS, VNREDSAT-1 and altimeter, are applied for researching marine environment with the different resolutions. On the basis of different time remote sensing images, we concentrated on the assessment of several characteristics including the SST, chlorophyll-a concentration and sea surface current at the different depths in different monsoons as well. With the large areas, we used the images of MODIS and altimeter. The detailed research area focuses on the Nam Yet island, and the images of VNREDSAT-1 are used. The analysis method of environmental parameters of SST and chlorophyll-a used the regression functions based on the single and combined bands to enhance the accuracy of the analysis result. The marine parameters collected at different depths in the latest field surveys on Truong Sa archipelago in the years of 2015 and 2018 are presented in this paper. On the basis of these parameters, we can analyse the relationships and compare the real field survey data and corresponding results interpreted from remote sensing images

COMO É QUE OS ESTUDANTES DE MEDICINA E ENFERMAGEM VEEM A TECNOLOGIA DE SAÚDE? UM ESTUDO DE VALIDAÇÃO PSICOMÉTRICA DO QUESTIONÁRIO DE AVALIAÇÃO DE USABILIDADE EM BANGLADESH

The modernization of healthcare delivery is a reality in various international settings. To ensure efficient and safe use of the diverse forms of healthcare technology available, professionals and students must be receptive to incorporating such tools into their practice. Currently, there is no instrument in Bangladesh to assess healthcare students’ technology acceptance. Objective: To translate, culturally adapt, and validate the Usability Evaluation Questionnaire (UtEQ) among Bangladeshi healthcare students. Method: A cross-sectional study with a methodological approach was conducted in two phases. The first phase involved the translation of the UtEQ questionnaire to Bengali, following the six stages proposed by Beaton et al. In the second phase, the psychometric properties of the questionnaire were evaluated using a non-probability sample of 486 undergraduate healthcare students from three higher education institutions in Bangladesh. Confirmatory factor analysis was performed, and the Cronbach’s alpha coefficient was estimated to find out the internal consistency. Results: Internal consistency was found to be excellent for all scale dimensions, ranging from 0.88 to 0.92, while confirmatory factor analysis showed adequate goodness-of-fit indicators. Conclusion: The UtEQ-B provides a reliable and valid method for healthcare educators and researchers to assess technology acceptance among healthcare students during clinical training in Bangladesh.A modernização da prestação de cuidados de saúde é uma realidade em vários contextos internacionais. Para garantir a utilização eficiente e segura das diversas formas de tecnologia em saúde disponíveis, os profissionais e estudantes devem estar receptivos à incorporação dessas ferramentas na sua prática. Atualmente, não existe em Bangladesh um instrumento para avaliar a aceitação da tecnologia pelos estudantes de saúde. Objetivo: Traduzir, adaptar culturalmente e validar o Questionário de Avaliação da Usabilidade (UtEQ) entre estudantes de saúde de Bangladesh. Método: Foi realizado um estudo transversal com uma abordagem metodológica em duas fases. A primeira fase envolveu a tradução do questionário UtEQ para bengali, seguindo as seis etapas propostas por Beaton et al. Na segunda fase, foram avaliadas as propriedades psicométricas do questionário usando uma amostra não probabilística de 486 estudantes de graduação em saúde de três instituições de ensino superior em Bangladesh. Foi realizada uma análise fatorial confirmatória e estimou-se o coeficiente alfa de Cronbach para verificar a consistência interna. Resultados: Foi encontrada uma consistência interna excelente para todas as dimensões da escala, variando de 0,88 a 0,92, enquanto a análise fatorial confirmatória mostrou indicadores adequados de ajuste. Conclusão: O UtEQ-B fornece um método confiável e válido para educadores e pesquisadores em saúde avaliarem a aceitação da tecnologia entre estudantes de saúde durante o treinamento clínico em Bangladesh