Initial study of single nucleotide polymorphism genotyping of Epstein-barr nuclear antigen 1 (EBNA-1) from Vietnamese nasopharyngeal biopsy samples

Background: Epstein-Barr virus nuclear antigen (EBNA1), encoded by EBNA-1 gene, has been shown as one of the most frequently detected protein in Nasopharyngeal carcinoma (NPC), which the most common and highly incident cancer of head and neck cancer in Asian countries. The geographically-associated polymorphisms of EBNA-1 have been observed in East-Southern Asia, including Vietnam. The subtype V-val EBNA-1 has been demonstrated that it may contribute to the oncogenesis of NPC. This current study is initially performed to characterize the variations of EBNA-1 in NPC biopsy samples from Vietnamese patients. Methods: Nested PCR-sequencing was applied to amplify and characterize the C-terminal region of EBNA-1 gene by the designed oligonucleotide primers. Results: 10 NPC biopsy samples were enrolled, as the results, only two patterns of EBNA-1 variations: P-ala and V-val were observed. In addition, of these two subtypes, the frequency of V-val and P-ala were determined counting for 80% (8 of 10 cases) and 20% (2 of 10 cases), respectively. It indicated the V-val subtype preferentially exists in biopsy NPC samples, which collected from Vietnamese patients. Conclusion: We successfully designed the nested PCR-sequencing primer for detection of EBNA-1 variations based on the data collected from previous study. In our initial study, the sub-strain of EBV with V-val subtype of EBNA-1 infects NPC preferentially to those from biopsies of NPC patients. In further study, it is necessary for a larger number of samples and non-cancerous samples in order to confirm the characteristic of EBNA-1 variations, as well as determination of the association V-val subtype with NPC in Vietnamese patients

Bridging to mathematical modelling : Vietnamese students’ response to different levels of authenticity in contextualized tasks

To address the upcoming reform curriculum initiative following competency-based learning in Vietnam, this study examines how variations of a contextualized task allow students to experience the mathematical modelling process. We explore how Grade 10 students respond to tasks with different levels of authenticity when they first attempt such tasks. Adapting the Theory of Authentic Task Situations, we designed variations of the Goat Cage task and implemented them with six small groups of students. Results showed that the modelling processes that the students progressed through differed in mathematical models used and real-world considerations, with diverse approaches when solving the more-authentic variation. Not all phases of the modelling process were observed explicitly when they engaged in the tasks. Students showed a positive disposition towards tasks with more authentic contextual information. The study suggests ways to adapt contextualized tasks to make them more authentic, which allows students to experience a holistic modelling process

Factors Determining the Removal Efficiency of Procion MX in Waters Using Titanate Nanotubes Catalyzed by UV Irradiation

The treatment of wastewater from the textile industry containing organic dyes faces many challenges since these compounds resist the biodegradation process in conventional treatment units. Among the physicochemical processes, photocatalysis is considered a facile, cheap, and environmental-friendly technology for treating persistent organic pollutants in waters at low concentrations. This study investigated several physicochemical factors determining the photocatalytic activity of titanate nanotubes (TNTs) to remove Procion MX 032 (PMX), an azo dye, in waters. Degradation of PMX by photocatalytic oxidation process at room temperature (30°C) was set up with the UV irradiation in the presence of different types of photocatalyst such as ST-01 (100% anatase), industrial TiO2, TNTs calcined at 120°C and 500°C. Effect of reaction time, catalyst amount, pH, light wavelength and intensity, and oxidants was investigated. Consequently, TNTs calcined at 500°C provided the highest removal efficiency. The photocatalytic oxidation of PMX by TNT calcined at 500°C was affected by pH variation, getting the highest removal at pH of 8, and inhibited with the presence of H2O2 and O2. Particularly, the PMX degradation using titanate nanotubes was optimized under the UV-A intensity of 100 W/m2. The dye was degraded by more than 95% at the TNTs concentration of 75 mg/L and pH 8.0 after 90 min. The results suggest that photocatalysis using TNTs can be a simple but efficient treatment method to remove PMX and potentially be applied for the treatment of wastewaters containing dyes

Characterization of Co2+- and Fe3+-Codoped TiO2 Nanomaterials for Photocatalytic Degradation of Organic Pollutants under Visible Light Irradiation

In this study, TiO2 nanomaterials were prepared using a solvothermal method and codoped with Co2+ and Fe3+ ions for the photocatalytic degradation of organic pollutants under visible light. The physicochemical properties of the obtained materials were studied by powder X-ray diffraction, field emission electron scanning microscopy, energy-dispersive X-ray spectroscopy, and nitrogen adsorption isotherms. Optical absorption was characterized by UV-vis absorption spectroscopy. The photocatalytic activities of the prepared materials were evaluated through methylene blue (MB) degradation under visible light irradiation. Results showed the excellent performance of MB degradation investigated on TiO2 samples codoped with Co2+ and Fe3+ in comparison with undoped and Co2+-doped TiO2 samples. The codoped TiO2 samples degraded 85%–90% of MB after 120 min, whereas all the prepared TiO2 samples were composed of pure anatase phase and had a spherical-like shape and mean crystalline size ranging from 6.2 nm to 7.8 determined by Scherrer’s equation. The optical absorption of the TiO2 codoped with Co2+ and Fe3+ was significantly enhanced toward the visible light region. The pseudo-second-order kinetic model fits well for the degradation of MB on as-prepared TiO2 codoped with Co2+ and Fe3+

Feasibility of combining short tandem repeats (STRs) haplotyping with preimplantation genetic diagnosis (PGD) in screening for beta thalassemia

β-thalassemia is an autosomal recessive disease with the reduction or absence in the production of β-globin chain in the hemoglobin, which is caused by mutations in the Hemoglobin subunit beta (HBB) gene. In Vietnam, the number of β-thalassemia carriers range from 1.5 to 25.0%, depending on ethnic and geographical areas, which is much higher than WHO’s data worldwide (1.5%). Hence, preimplantation genetic diagnosis (PGD) plays a crucial role in reducing the rate of β-thalassemia affected patients/carriers. In this research, we report the feasibility and reliability of conducting PGD in combination with the use of short tandem repeat (STR) markers in facilitating the birth of healthy children. Six STRs, which were reported to closely linked with the HBB gene, were used on 15 couples of β-thalassemia carriers. With 231 embryos, 168 blastocysts were formed (formation rate of 72.73%), and 88 were biopsied and examined with STRs haplotyping and pedigree analysis. Thus, the results were verified by Sanger sequencing, as a definitive diagnosis. Consequently, 11 over 15 couples have achieved pregnancy of healthy or at least asymptomatic offspring. Only three couples failed to detect any signs of pregnancy such as increased Human Chorionic Gonadotropin (HCG) level, foetal sac, or heart; and one couple has not reached embryo transfer as they were proposed to continue with HLA-matching to screen for a potential umbilical cord blood donor sibling. Thus, these results have indicated that the combination of PGD with STRs analysis confirmed by Sanger sequencing has demonstrated to be a well-grounded and practical clinical strategy to improve the detection of β-thalassemia in the pregnancies of couples at-risk before embryo transfer, thus reducing β-thalassemia rate in the population

Side effects following first dose of COVID-19 vaccination in Ho Chi Minh City, Vietnam

Vaccines are strongly recommended globally as an effective measure to prevent serious illness from and spread of COVID-19. Concerns about safety following vaccination continue to be the most common reason that people do not accept the vaccine. This retrospective study was carried out on 4341 people who received the first dose of ChAdOx1 nCoV-19, BBIBP-CorV, or mRNA-1273 vaccine at Jio Health Clinic in Ho Chi Minh City, Vietnam. Post-injection side effects were either reported by participants or actively collected by health care staff by means of telemedicine. Local side effects were reported by 35.5% of all individuals, with pain being the most common symptom (33.3%). Systemic side effects were reported by 44.2% of individuals, with fever (25.3%) and fatigue (21.4%) being the most common. Age ≤60 years, female gender, and ChAdOx1 nCoV-19 were significant independent risk factors for both local and systemic side effects, while a history of allergy was significant as a risk factor for local side effects. A total of 43 individuals (1.0%) reported concerning symptoms of rare severe complications, which were addressed and treated by physicians via Jio Health app