Sleep Quality and Poor Sleep-related Factors Among Healthcare Workers During the COVID-19 Pandemic in Vietnam

Thang Phan,Ha Phan Ai Nguyen,Cao Khoa Dang,Minh Tri Phan,Vu Thanh Nguyen,Van Tuan Le,Binh Thang Tran,Chinh Van Dang,Tinh Huu Ho,Minh Tu Nguyen,Thang Van Dinh,Van Trong Phan,Binh Thai Dang,Huynh Ho Ngo The Korean Society for Preventive Medicine 2023 예방의학회지 Vol.56 No.4

Objectives: The coronavirus disease 2019 (COVID-19) pandemic has increased the workload of healthcare workers (HCWs), impacting their health. This study aimed to assess sleep quality using the Pittsburgh Sleep Quality Index (PSQI) and identify factors associated with poor sleep among HCWs in Vietnam during the COVID-19 pandemic. Methods: In this cross-sectional study, 1000 frontline HCWs were recruited from various healthcare facilities in Vietnam between October 2021 and November 2021. Data were collected using a 3-part self-administered questionnaire, which covered demographics, sleep quality, and factors related to poor sleep. Poor sleep quality was defined as a total PSQI score of 5 or higher. Results: Participants' mean age was 33.20±6.81 years (range, 20.0-61.0), and 63.0% were women. The median work experience was 8.54±6.30 years. Approximately 6.3% had chronic comorbidities, such as hypertension and diabetes mellitus. About 59.5% were directly responsible for patient care and treatment, while 7.1% worked in tracing and sampling. A total of 73.8% reported poor sleep quality. Multivariate logistic regression revealed significant associations between poor sleep quality and the presence of chronic comorbidities (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.17 to 5.24), being a frontline HCW directly involved in patient care and treatment (OR, 1.59; 95% CI, 1.16 to 2.16), increased working hours (OR, 1.84; 95% CI,1.37 to 2.48), and a higher frequency of encountering critically ill and dying patients (OR, 1.42; 95% CI, 1.03 to 1.95). Conclusions: The high prevalence of poor sleep among HCWs in Vietnam during the COVID-19 pandemic was similar to that in other countries. Working conditions should be adjusted to improve sleep quality among this population.

Preparation and Characterization of Nanocomposites Based on Poly(ethylene-co-vinyl acetate), Polylactic Acid, and TiO₂ Nanoparticles

Do Van Cong,Nguyen Thi Thu Trang,Nguyen Vu Giang,Tran Huu Trung,Nguyen Thuy Chinh,Mai Duc Huynh,Thai Hoang,Jun Seo Park(박준서) 한국고분자학회 2016 폴리머 Vol.40 No.3

This study describes the preparation and characterization of nanocomposites obtained by melt-mixing of poly (ethylene-co-vinyl acetate) (EVA), polylactic acid (PLA), and TiO₂ nanoparticles (TNPs) via three different methods of direct mixing, one-step, and two-step methods. Vinyltrimethoxysilane was used as a surface modifier for the TNPs. The one-step method showed the best suitability for the preparation of EVA/PLA/TiO₂ nanocomposites. The increase in torque and the adhesion of the TNPs with EVA/PLA matrix in these nanocomposites showed enhanced interfacial interactions between EVA, PLA chains, and TNPs. The tensile strength, Young’s modulus, dynamic storage modulus, and thermooxidative stability of the one-step prepared nanocomposites were higher than those of two other nanocomposites and that of the EVA/PLA blend, reaching maximum values at 2.0 wt% of TNPs.

Some geomorphic indices in the North Central Vietnam

Nguyen Anh Duong,Vu Van Chinh 한국지질과학협의회 2021 Geosciences Journal Vol.25 No.6

We have applied geomorphology to investigate the tectonic fault in the North Central Vietnam. At the local scale, the active tectonic possibility of fault zones in the study area is geomorphologically assessed for the first time. The results show the geomorphic indices of drainage basin asymmetry (AF = 0–34), valley floor width-to-height ratio (Vf = 0.21–1.71) applied to 50 drainage basins and mountain-front sinuosity (Smf = 1.07–1.58) calculated along 17 tectonic fault zones. The geomorphic analysis indicates that the modern activity of faults in the study area is moderate–weak. Only a few segments of the Truong Son and Dakrong-Hue faults are assessed as strongly active. The tectonic activity of this area is assessed with an average uplifting rate of about 0.2 mm/year according to the Smf and Vf analyses. In order to prove the existence of faults as well as their active possibility, the field survey has also been carried out by structural geological and geomorphological methods. The survey was conducted at 369 outcrops and approximately 12,000 fractures were measured. Based on the data on displacement and the processing of data on slip observed at the outcrops, we have identified the strike-slip tectonic stress state of Pliocene–Quaternary period with the sub-longitudinal compressional direction and the slip mechanism of fault zones in this period. It is a new finding of the contemporary crustal stress orientation of North Central Vietnam. The results of this study provided the geomorphic evidence to evaluate the potential seismic hazards of the North Central Vietnam.

Design, Synthesis and In Vitro Cytotoxic Activity Evaluation of New Mannich Bases

Bui, Trung Hieu,Le, Thi Thuy,Vu, Thu Thuy,Hoang, Xuan Tien,Luu, Van Chinh,Vu, Dinh Hoang,Tran, Khac Vu Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.5

A series of Novel Mannich bases has been synthesized and evaluated $in$ $vitro$ cytotoxic activity against the human hepatocellular carcinoma (HepG2), human lung carcinoma (SK-LU-1), and human breast cancer (MCF-7). Compound $\mathbf{9f}$ was found to be most potent against three cell lines with $IC_{50}$ values of 1.57, 1.16 and 1.21 ${\mu}g$/mL, respectively. In addition, compounds $\mathbf{9g}$, $\mathbf{10f}$ exhibited very significant activity against MCF-7 cell line with $IC_{50}$ values of 2.0 ${\mu}g$/mL.

The potential efficacy of the E2-subunit vaccine to protect pigs against different genotypes of classical swine fever virus circulating in Vietnam

Ha Thi Thanh Tran,Duc Anh Truong,Viet Duc Ly,Hao Thi Vu,Tuan Van Hoang,Chinh Thi Nguyen,Nhu Thi Chu,Vinh The Nguyen,Duyen Thuy Nguyen,Kohtaroh Miyazawa,Takehiro Kokuho,Hoang Vu Dang 대한백신학회 2020 Clinical and Experimental Vaccine Research Vol.9 No.1

Purpose: To date, many kinds of classical swine fever (CSF) vaccines have been developed to protect against this disease. However, the efficacy of these vaccines to protect the pig against field CSF strains needs to be considered, based on circulating strains of classical swine fever virus (CSFV). Materials and Methods: Recombinant E2-CSFV protein produced by baculovirus/insect cell system was analyzed by western blots and immunoperoxidase monolayer assay. The effect of CSFV-E2 subunit vaccines was evaluated in experimental pigs with three genotypes of CSFV challenge. Anti-E2 specific and neutralizing antibodies in experimental pigs were analyzed by blocking enzyme-linked immunosorbent assay and neutralization peroxidize-linked assay. Results: The data showed that CSFV VN91-E2 subunit vaccine provided clinical protection in pigs against three different genotypes of CSFV without noticeable clinical signs, symptoms, and mortality. In addition, no CSFV was isolated from the spleen of the vaccinated pigs. However, the unvaccinated pigs exhibited high clinical scores and the successful virus isolation from spleen. These results showed that the E2-specific and neutralizing antibodies induced by VN91-E2 antigen appeared at day 24 after first boost and a significant increase was observed at day 28 (p<0.01). This response reached a peak at day 35 and continued until day 63 when compared to controls. Importantly, VN91-E2 induced E2-specific and neutralizing antibodies protected experimental pigs against high virulence of CSFVs circulating in Vietnam, including genotype 1.1, 2.1, and 2.2. Conclusion: These findings also suggested that CSFV VN91-E2 subunit vaccine could be a promising vaccine candidate for the control and prevention of CSFV in Vietnam.

An improvement of real-time polymerase chain reaction system based on probe modification is required for accurate detection of African swine fever virus in clinical samples in Vietnam

Tran Ha Thi Thanh,Dang Anh Kieu,Ly Duc Viet,Vu Hao Thi,Hoang Tuan Van,Nguyen Chinh Thi,Chu Nhu Thi,Nguyen Vinh The,Nguyen Huyen Thi,Truong Anh Duc,Pham Ngoc Thi,Dang Hoang Vu 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.10

Objective: The rapid and reliable detection of the African swine fever virus (ASFV) plays an important role in emergency control and preventive measures of ASF. Some methods have been recommended by FAO/OIE to detect ASFV in clinical samples, including real-time polymerase chain reaction (PCR). However, mismatches in primer and probe binding regions may cause a false-negative result. Here, a slight modification in probe sequence has been conducted to improve the qualification of real-time PCR based on World Organization for Animal Health (OIE) protocol for accurate detection of ASFV in field samples in Vietnam. Methods: Seven positive confirmed samples (four samples have no mismatch, and three samples contained one mutation in probe binding sites) were used to establish novel real-time PCR with slightly modified probe (Y = C or T) in comparison with original probe recommended by OIE. Results: Both real-time PCRs using the OIE-recommended probe and novel modified probe can detect ASFV in clinical samples without mismatch in probe binding site. A high correlation of cycle quantification (Cq) values was observed in which Cq values obtained from both probes arranged from 22 to 25, suggesting that modified probe sequence does not impede the qualification of real-time PCR to detect ASFV in clinical samples. However, the samples with one mutation in probe binding sites were ASFV negative with OIE recommended probe but positive with our modified probe (Cq value ranked between 33.12-35.78). Conclusion: We demonstrated for the first time that a mismatch in probe binding regions caused a false negative result by OIE recommended real-time PCR, and a slightly modified probe is required to enhance the sensitivity and obtain an ASF accurate diagnosis in field samples in Vietnam.