Rotavirus (RV), Norovirus (NV), Sapovirus (SaV) and Astrovirus (Ast) are the leading causes of gastroenteritis and mortality in children worldwide. RV vaccines help to reduce the burden of diarrhea while the importance of other viruses is increasing. Therefore, we conducted a cross-sectional descriptive study to determine prevalence of these viruses in hospitalized children under 5 years old in Nam Dinh province with approximately 80% of RV vaccine coverage. We randomly selected 579 (25%) among diarrheal samples collected in 4 district hospitals from Dec. 2017 to Nov. 2019. An ELISA kit was employed to detect RV and the multiplex real-time RT-PCR with specific primers to detect NV, SaV and Ast. These viruses were found among 64.3% of hospitalized children, of which NV and RV were present in 28.5% and 21.4%, respectively, while SaV and Ast were detected in 3.3% and 2.6%, respectively. Co-infections accounted for 8.5%, mainly among RV and 3 other viruses. There is a significant difference in RV and NV positive rates between vaccinated and unvaccinated groups (p < 0.001 and p = 0.008, respectively). This study contributed to the understanding of the potential impact of rotavirus vaccine on other diarheal pathogens and emphasize the need for further epidemiological studies when the nationwide RV vaccination in Vietnam is implementing.

The COVID-19 pandemic has led to disruptions in consumers' lifestyles and purchases, as well as businesses' online business models. Online platforms are increasingly used for shopping purposes. To evaluate and choose an e-commerce platform requires using many criteria and decision makers. Therefore, the process of evaluating and selecting an e-commerce platform is viewed as a multi-criteria decision-making problem. The objective of this study is to develop a multi-criteria decision-making model to help consumers evaluating the e-commerce platforms. In the proposed model, the ratings of alternatives and the weights of the criteria are evaluated using the linguistic variable. Simulation examples are used to show the effectiveness of the model in practice.  Keywords: Fuzzy TOPSIS, E-Commerce Platform, Mcdm, Fuzzy Sets.

Because of the great benefits overseas investment brings, countries and businesses are increasingly concerned with the question of an ideal investment destination. Many studies have shown that, factors of the consumption market, the infrastructure and resources, economic and political environment have a significant impact on the decision to choose an investment location, however the priority order of these factors are different for various research spaces. By studying the specific case of Viettel Group - one of the largest telecommunications groups in Vietnam that is having many international investment activities in recent years, the study has been verified the priority order of factors influencing the decision to choose an overseas investment location of this corporation. The research outcomes show that the group of factors that have the most influence on investment decisions is the group "Consumption market", more specifically, the sub-factor "Market Size" is considered more than the others.    Keywords: Investment Destinations, Foreign Investment Decision, Analytic Hierarchy Process.