Smartphone indoor positioning based on enhanced BLE beacon multi-lateration

In this paper, we introduce a smartphone indoor positioning method using bluetooth low energy (BLE) beacon multilateration. At first, based on signal strength analysis, we construct a distance calculation model for BLE beacons. Then, with the aims to improve positioning accuracy, we propose an improved lateral method (range-based method) which is applied for 4 nearby beacons. The method is intended to design a real-time system for some services such as emergency assistance, personal localization and tracking, location-based advertising and marketing, etc. Experimental results show that the proposed method achieves high accuracy when compared with the state of the art lateral methods such as geometry-based (conventional trilateration), least square estimation-based (LSE-based) and weighted LSE-based

iBeacon-based indoor positioning system: from theory to practical deployment

Developing an indoor positioning system became essential when global positioning system signals could not work well in indoor environments. Mobile positioning can be accomplished via many radio frequency technology such as Bluetooth low energy (BLE), wireless fidelity (Wi-Fi), ultra-wideband (UWB), and so on. With the pressing need for indoor positioning systems, we, in this work, present a deployment scheme for smartphone using Bluetooth iBeacons. Three main parts, hardware deployment, software deployment, and positioning accuracy assessment, are discussed carefully to find the optimal solution for a complete indoor positioning system. Our application and experimental results show that proposed solution is feasible and indoor positioning system is completely attainable

Electrodeposition of HAp coatings on Ti6Al4V alloy and its electrochemical behavior in simulated body fluid solution

Hydroxyapatite (HAp) coatings were prepared on Ti6Al4V substrate by electrodeposition method from electrolyte solution containing Ca(NO3)2, NH4H2PO4 and NaNO3. The results show that the HAp coatings were single phase crystals of HAp. Scanning electron microscope (SEM) images present that HAp/Ti6Al4V have flake shapes which arrange to form like-coral agglomerates. In vitro test of the Ti6Al4V and HAp/Ti6Al4V in simulated body fluid (SBF) solution was investigated with different immersion times. pH of SBF solution decreased and the mass of materials increased. SEM images prove the formation of apatite on the surface of Ti6Al4V and HAp/Ti6Al4V. The corrosion current density during immersion time of substrate is always higher than the one of HAp/Ti6Al4V because the deposited HAp can protect well for the substrate

Penetrating Keratoplasty for Keratoconus in Vietnamese Patients

BACKGROUND: Keratoconus is an ectatic corneal disorder that can impair the visual acuity. Up to now, penetrating keratoplasty (PK) remains the most common surgical procedure to treat severe keratoconus. In Vietnam, most keratoconus patients come to visit doctor at severe stage and were treated by PK, so we conduct this study. AIM: To evaluate the results of PK for keratoconus in Vietnamese patients. METHODS: This was a retrospective study of 31 eyes with keratoconus who underwent PK in VNIO from January 2005 to December 2014. RESULTS: The average visual acuity was 0.86 ± 0.37 logMAR (20/145). In the group of patients without amblyopia, best spectacle-corrected visual acuity of 20/60 or better was recorded in 75.9% of eyes and 93.1% of eyes achieved a best corrected visual acuity with hard contact lenses of 20/40 or better. Mean postoperative corneal power was 43.8 ± 4.5D. Mean corneal astigmatism was 5.9 ± 2.7D. 94.6% of grafts remained clear. Posterior subcapsular cataract developed in 22.6% of eyes. Graft rejection was recognized in 12.9% of eyes. CONCLUSION: PK is an effective procedure with high rate of graft survival for keratoconus patients. However, patients should be aware of the necessary of optical correction to gain the best VA after surgery

Some preliminary results of paleo-tsunami study in the coastal region of the Nghe An province, Vietnam

In the coastal region of the Nghe An province, the geomorphology is characterized by appearances of fields of arca granosa with placura placenta and hills of placura placenta with arca granosa, namely: The hills of placura placenta with the arca granosa shells in the Quynh Van and Nghi Tien communes; the fields of arca granosa with the placura placenta: deep-seated in the Quynh Nghia, Dien Chau and along the Nghi Yen coast  which have age of 4,500 - 4,300 yrs.; The appearance of the placura placenta-arca granosa shell’s fields and hills which do not originate from either marine transgression in the Holocene epoch, tectonic movement or artificiality; Our results suggest that there were three tsunami events occurring in the past during the periods of 4,500 - 4,300; 4,100 - 3,900 and 900 - 600 yrs., respectively in the region

The Epidemiology of Interpandemic and Pandemic Influenza in Vietnam, 2007–2010: The Ha Nam Household Cohort Study I

Prospective community-based studies have provided fundamental insights into the epidemiology of influenza in temperate regions, but few comparable studies have been undertaken in the tropics. The authors conducted prospective influenza surveillance and intermittent seroprevalence surveys in a household-based cohort in Vietnam between December 2007 and April 2010, resulting in 1,793 person-seasons of influenza surveillance. Age- and sex-standardized estimates of the risk of acquiring any influenza infection per season in persons 5 years of age or older were 21.1% (95% confidence interval: 17.4, 24.7) in season 1, 26.4% (95% confidence interval: 22.6, 30.2) in season 2, and 17.0% (95% confidence interval: 13.6, 20.4) in season 3. Some individuals experienced multiple episodes of infection with different influenza types/subtypes in the same season (n = 27) or reinfection with the same subtype in different seasons (n = 22). The highest risk of influenza infection was in persons 5–9 years old, in whom the risk of influenza infection per season was 41.8%. Although the highest infection risk was in school-aged children, there were important heterogeneities in the age of infection by subtype and season. These heterogeneities could influence the impact of school closure and childhood vaccination on influenza transmission in tropical areas, such as Vietnam

Experiência de aprendizagem de estudantes de enfermagem na prevenção e controlo de infeções associadas aos cuidados de saúde (PC-IACS) em países asiáticos: um estudo qualitativo exploratório

Background: Healthcare-associated infection prevention and control (HAI-PC) education programs in Asian countries seem limited and require improvement and support. Objective: This study explored students’ learning experiences with HAI-PC education programs in Asian countries (two Vietnamese and two Cambodian universities) to support a pedagogical model in HAI-PC. Method: A qualitative exploratory study design was employed, and inductive content analysis was conducted. Students were selected to participate in the focus group to investigate their experiences with HAI-PC using five structured questions. There were 48 nursing students in total from four universities, 28 from 2 universities in Cambodia, and 20 from two universities in Vietnam. Results: The summary results gained from the four universities were synthesized by grouping them into sub-categories and four primary categories, which were students’ HAI-PC competence, students’ current learning methods in HAI-PC Education, the HAI-PC teaching and learning environment, students’ capacity, and entrepreneurial skills in HAI-PC development. Conclusion: This study revealed evidence to improve nursing education in HAI-PC in Asian countries. The new learning method of the simulation scenario and the model fascinated the students; they were happy and more confident about their future careers in practicing HAI-PC skills in their clinical practicum and hospital practice. The current HAI-PC education faces issues related to education and healthcare systems in Asian countries, highlighting the need for improvement.Enquadramento: Os programas de educação em prevenção e controlo de infeções associadas aos cuidados de saúde (PC-IAS) em países asiáticos parecem ser limitados e necessitam de melhorias e apoio. Objetivo: Este estudo explorou as experiências de aprendizagem dos estudantes com programas de educação em PC-IAS em países asiáticos (duas universidades vietnamitas e duas universidades cambojanas) para apoiar um modelo pedagógico em PC-IAS. Método: Foi utilizado um desenho de estudo exploratório qualitativo, e foi realizada uma análise de conteúdo indutiva. Os estudantes foram selecionados para participar no grupo focal para investigar as suas experiências com PC-IAS usando cinco perguntas estruturadas. No total, participaram 48 estudantes de enfermagem de quatro universidades, sendo 28 de duas universidades no Camboja e 20 de duas universidades no Vietname. Resultados: Os resultados resumidos das quatro universidades foram sintetizados agrupando-os em subcategorias e quatro categorias principais, que eram competência dos estudantes em PC-IAS, métodos de aprendizagem atuais dos estudantes em Educação em PC-IAS, ambiente de ensino e aprendizagem em PC-IAS, capacidade dos estudantes e habilidades empreendedoras no desenvolvimento de PC-IAS. Conclusão: Este estudo revelou evidências para melhorar a educação em enfermagem em PC-IAS em países asiáticos. O novo método de aprendizagem do cenário de simulação e o modelo cativaram os estudantes; eles ficaram felizes e mais confiantes em relação às suas futuras carreiras na prática de habilidades em PC-IAS no estágio clínico e na prática hospitalar. A educação atual em PC-IAS enfrenta questões relacionadas aos sistemas de educação e saúde em países asiáticos, destacando a necessidade de melhorias

Simulação como método de ensino na formação em enfermagem na prevenção e controlo de infeções associadas aos cuidados de saúde em países asiáticos: um estudo qualitativo

Background: Applying simulation for nursing education, especially in healthcare-associated infection prevention and control (HAI-PC) in developing countries has limited evidence. The study was conducted to explore educators’ perceptions of simulation as a teaching method for nursing education in HAI-PC in two Vietnamese and two Cambodian universities. Methods: An exploratory qualitative design was applied. A focus group of 37 educators from four universities was conducted for data collection. Inductive and deductive qualitative content analysis was applied in analysing the data. Results: The core category was constructed to reflect educators’ perception of scenario-based simulation (SBS) as a teaching method for nursing education in HAI prevention and control. This main category included three subcategories: (i) enhancing nursing competence; (ii) preparing students for simulation; and [1] promoting simulation pedagogy competence. Conclusions: The findings identified the importance and benefits of applying simulation as a teaching method in nursing education. Additionally, it emphasized the necessity of enhancing knowledge associated with HAIs and providing additional training on simulation for educators to improve the quality of conducting simulations.Enquadramento: A aplicação da simulação no ensino de enfermagem, especialmente na prevenção e controlo de infeções associadas aos cuidados de saúde (IACS), em países em desenvolvimento, tem evidências limitadas. O estudo foi conduzido para explorar as perceções dos educadores sobre a simulação como método de ensino para a formação em enfermagem na prevenção e controlo de IACS em duas universidades vietnamitas e duas universidades cambojanas. Métodos: Foi aplicado um desenho qualitativo exploratório. Um grupo de discussão com 37 educadores de quatro universidades foi conduzido para a recolha de dados. A análise qualitativa de conteúdo indutiva e dedutiva foi aplicada na análise dos dados. Resultados: A categoria central foi construída para refletir a perceção dos educadores sobre a simulação baseada em cenários (SBC) como método de ensino para a formação em enfermagem na prevenção e controlo de IACS. Esta categoria principal incluiu três subcategorias: (i) aprimoramento da competência em enfermagem; (ii) preparação dos estudantes para a simulação; e [1] promoção da competência em pedagogia de simulação. Conclusões: Os resultados identificaram a importância e benefícios da aplicação da simulação como método de ensino na formação em enfermagem. Além disso, enfatizou a necessidade de aprimorar o conhecimento associado às ICACS e fornecer treinamento adicional sobre simulação para educadores, visando melhorar a qualidade da condução das simulações

Experiências do estudante de enfermagem na aprendizagem da prevenção e controlo de IACS em países asiáticos através do uso de simulação baseada em cenários: um estudo qualitativo exploratório

Background: Healthcare-associated infections (HAIs) have posed a major threat to both patients and to the safety healthcare personnel worldwide. According to the World Health Organization, 10% of hospitalized patients are affected by HAIs worldwide. Objective: The objective of this study was to explore the experiences of nursing students in learning HAIs prevention and control by the application of the scenario-based simulation pedagogy now in use in two Vietnamese and two Cambodian universities. Methods: A qualitative study was conducted among 160 nursing students from 2 Cambodian universities and 2 Vietnamese universities, and by using the purposive-sampling method. The data were collected through a focus group discussion and analyzed by the Graneheim and Lundman method (Graneheim & Lundman, 2004). Results: Two themes and six categories were generated. 1) First theme: factors for enhancing student learning on the prevention and control of HAIs by use of scenario-based simulation; and 2) Second theme: factors hindering students learning on HAI prevention and control by use of scenario-based simulation. Conclusion: The findings showed that SBS is an effective learning method for nursing students that can be applied to enhance the quality of nursing education in the Asian countries as SBS not only improves the clinical skills, but also the soft skills of nursing students. However, the effective outcomes and impacts can only be achieved in the context with the appropriate learning materials and equipment, simulation facilities and the instructors with pedagogical skills.Enquadramento: As infeções associadas a cuidados de saúde (IACS) têm representado uma grande ameaça tanto para os pacientes quanto para a segurança dos profissionais de saúde em todo o mundo. De acordo com a Organização Mundial da Saúde, 10% dos pacientes hospitalizados são afetados por IACS em todo o mundo. Objetivo: O objetivo deste estudo foi explorar as experiências dos estudantes de enfermagem na aprendizagem da prevenção e controlo de IACS através da aplicação da pedagogia de simulação baseada em cenários, atualmente em uso em duas universidades vietnamitas e duas universidades cambojanas. Métodos: Um estudo qualitativo foi conduzido entre 160 estudantes de enfermagem de duas universidades cambojanas e duas universidades vietnamitas, utilizando o método de amostragem propositada. Os dados foram recolhidos através de uma discussão em grupo focal e analisados pelo método de Graneheim e Lundman (Graneheim & Lundman, 2004). Resultados: Dois temas e seis categorias foram gerados. 1) Primeiro tema: fatores que contribuem para a aprendizagem dos estudantes na prevenção e controlo de IACS pelo uso de simulação baseada em cenários; e 2) Segundo tema: fatores que impedem a aprendizagem dos estudantes na prevenção e controlo de IACS pelo uso de simulação baseada em cenários (SBC). Conclusão: Os resultados demonstraram que a SBC é um método de aprendizagem eficaz para estudantes de enfermagem que pode ser aplicado para melhorar a qualidade da educação em enfermagem nos países asiáticos, uma vez que a SBC não só melhora as habilidades clínicas, mas também as habilidades interpessoais dos estudantes de enfermagem. No entanto, os resultados e impactos efetivos só podem ser alcançados no contexto com os materiais e equipamentos de aprendizagem apropriados, instalações de simulação e instrutores com habilidades pedagógicas

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