Rapid Detection of SARS-CoV-2 Antigens and Antibodies Using OFET Biosensors Based on a Soft and Stretchable Semiconducting Polymer.

In the midst of the COVID-19 pandemic, adaptive solutions are needed to allow us to make fast decisions and take effective sanitation measures, e.g., the fast screening of large groups (employees, passengers, pupils, etc.). Although being reliable, most of the existing SARS-CoV-2 detection methods cannot be integrated into garments to be used on demand. Here, we report an organic field-effect transistor (OFET)-based biosensing device detecting of both SARS-CoV-2 antigens and anti-SARS-CoV-2 antibodies in less than 20 min. The biosensor was produced by functionalizing an intrinsically stretchable and semiconducting triblock copolymer (TBC) film either with the anti-S1 protein antibodies (S1 Abs) or receptor-binding domain (RBD) of the S1 protein, targeting CoV-2-specific RBDs and anti-S1 Abs, respectively. The obtained sensing platform is easy to realize due to the straightforward fabrication of the TBC film and the utilization of the reliable physical adsorption technique for the molecular immobilization. The device demonstrates a high sensitivity of about 19%/dec and a limit of detection (LOD) of 0.36 fg/mL for anti-SARS-Cov-2 antibodies and, at the same time, a sensitivity of 32%/dec and a LOD of 76.61 pg/mL for the virus antigen detection. The TBC used as active layer is soft, has a low modulus of 24 MPa, and can be stretched up to 90% with no crack formation of the film. The TBC is compatible with roll-to-roll printing, potentially enabling the fabrication of low-cost wearable or on-skin diagnostic platforms aiming at point-of-care concepts.

The global COVID-19 vaccine surplus: tackling expiring stockpiles.

BACKGROUND: A global surplus of coronavirus disease 2019 (COVID-19) vaccines exists as a result of difficulties in aligning the demand and supply for vaccine manufacturing and delivery. World leaders have accelerated vaccine development, approval, production and distribution as a pragmatic approach to addressing the immediate public health challenges of the first two and a half years of the pandemic. MAIN BODY: The currently predominant, highly transmissible Omicron variant of severe acute respiratory syndrome coronavirus 2 has brought us closer to the threshold required to achieve herd immunity by greatly increasing rates of natural infection. Paradoxically, in parallel with rising vaccination levels in industrialized nations, this indirectly reduces the need for mass vaccine campaigns. Principal concerns that contribute to low vaccination rates which persist in several other countries, particularly of the Global South, are vaccine hesitancy and unequal access to vaccination. Social uncertainty fueled by fake news, misinformation, unfounded lay opinions and conspiracy theories has inevitably led to an erosion of public trust in vaccination. CONCLUSION: To address the current mismatch between supply and demand of COVID-19 vaccines, there should be a focus on three principles: decelerating vaccine production, increasing distribution across communities, and optimizing cost-effectiveness of distribution logistics. Slowing down and switching from large-scale production to effectively 'made to order' is a feasible option, which should be commensurate with management capacity. Transparent and evidence-based data should be widely and freely disseminated to the public through multimedia channels to mitigate miscommunication and conspiracy theories. Use of soon-to-expire stockpiles should be prioritized not only to enhance booster dose rollouts in adults but to expand immunization campaigns to children (especially those aged 5-11 years), subject to national approval. Future research should ideally aim to develop vaccines that only require basic, affordable storage and maintenance procedures as opposed to sophisticated and expensive protocols.

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.

Evaluating the Impact of COVID-19 on the Behaviour of Pedestrians

The COVID-19 pandemic has considerably impacted pedestrians' perceived comfort in a public setting. The virus's transmissibility and social distancing restrictions have resulted in a shift in pedestrians' perceived comfort, with more pedestrians becoming more conscious of other pedestrians and the distance between pedestrians. The changes in pedestrians' perception have resulted in the Pedestrian Level Of Service (PLOS) models becoming outdated. The models may not accurately portray the actual status of pedestrians' Level Of Service (LOS) according to the pedestrian needs during a pandemic, which generally lasts for a couple of years. These pandemics will happen in the future;hence, their impact on pedestrian comfort on sidewalks is worth considering. This research aims to analyse the effect of COVID-19 on PLOS by compiling data using a face-to-face questionnaire survey in the Melbourne Central Business District (CBD). From the 445 completed surveys, 72% of respondents extensively considered social distancing due to COVID-19 when commuting in the CBD, and 49% preferred a 1-1.5 m distance between pedestrians. In conjunction with an in-depth analysis of the data, an ordinal regression model has been used to analyse the factors that influence the perceived comfort of the pedestrians and estimate the PLOS. The model results show that pedestrian density, COVID-19 social distancing, continuous footpath, and pedestrian flow in opposite directions on the sidewalk greatly impacted the walking comfort of pedestrians during the pandemic.

Experience and insights from the emergency multiday take-home dose methadone dispensing in Ho Chi Minh City in context of COVD-19.

Introduction: We aimed to assess the uptake of the pilot multiday take-home dose methadone program during COVID-19 by the patients and document the experience with this novel approach to Methadone Maintenance Treatment (MMT) in Vietnam through this operational research.Materials and methods: A total of 10 clinics were identified randomly using the PPS method. A total of 502 patients were selected from the clinics using a simple randomization technique. The information was collected from the administrative and treatment records and direct face-to-face interview with the patients.Results: None of the clinics reported an incidence of overdose. A large majority of the patients reported that take home methadone program as being convenient (79.6%) and agreed that they shall like to join the multiday take-home dose in future (98.7%).Conclusions: The findings of the current study suggested that the multiday take-home methadone program was feasible and well accepted by the patients in Ho Chi Minh City. It helped ensure continuity of care to patients on MMT during the COIVD-19 pandemic.

Guillain-Barré syndrome after COVID-19 vaccination: report of two cases from Vietnam.

Coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization in March 2020 and since then it has spread to almost every country around the world. Vaccines against COVID-19 are considered an essential measure to curb this pandemic. However, side effects, including local and systemic reactions, after administering the COVID-19 vaccine have been defined, and some side effects have been reported. We present two cases of Guillain-Barré Syndrome (GBS) after receiving the ChAdOx1 nCoV-19 vaccine (Oxford- AstraZeneca). Both cases were admitted to the 108 Military Central Hospital, Vietnam, and received plasmapheresis therapy with satisfactory recovery after treatment.

HOSPITALITY LEADERSHIP COMPETENCIES AND EMPLOYEE COMMITMENT: NEW INSIGHTS FROM THE BOOMING HOTEL INDUSTRY IN VIETNAM

Purpose - The purpose of this study is to examine how the leadership competencies of frontline managers influence the organizational commitment of their subordinates. The study further examines the relationship between the dominant (strongest) competency and organizational commitment and how this relationship is mediated by leadership consistency. Design - Data were collected from employees in seven hotels in two cities using a multilevel scale for competencies and standardized scales for leadership consistency and commitment. Construct validity of the hospitality leadership competency model (HLCM) was tested by confirmatory factor analysis. A stepwise analysis was run to identify dominant competencies (predictors). Finally, a moderated mediation model was tested. Methodology - This research adopted a quantitative approach to collect and analyse the data. Findings - All competencies were highly and positively related to organizational commitment, with team leadership being the dominant competency and predictor. A moderated mediation mechanism analysis shows that leadership consistency mediated the relationship between team leadership and organizational commitment, but this relationship was slightly attenuated by team size. Originality - The study contributes to (1) validating the HLCM at the frontline level and from the employees perspective, (2) quantifying the relationships between organizational commitment and leadership competencies, especially team leadership under the mediating effect of leadership consistency, and (3) creating several evidence-based implications for hospitality educators, employers, and managers.

Pulmonary arteriovenous malformation and inherent complications with solitary lung nodule biopsy-literature overview and case report.

Pulmonary arteriovenous malformation, also known as an arteriovenous fistula, is typically a congenital disease caused by structural deficiencies, particularly the lack of capillary wall development, leading to the abnormal dilation of the pulmonary capillaries. The majority of pulmonary arteriovenous malformation cases are associated with Rendu-Osler-Weber syndrome, also known as hereditary hemorrhagic telangiectasia. Pulmonary arteriovenous malformation rarely occurs due to chest trauma. Pulmonary arteriovenous malformations are long-lasting and often first diagnosed in adults. More than two-thirds of pulmonary arteriovenous malformation lesions are found in the lower lung lobe and the subpleural area, and the vast majority of cases present with the monofocal form. The initial diagnosis is often based on the identification of a solitary pulmonary nodule. However, a solitary nodule detected on chest computed tomography that is not correctly diagnosed as pulmonary arteriovenous malformation, even after intravenous contrast injection, can lead to the performance of a transthoracic biopsy. Biopsy of pulmonary arteriovenous malformations can lead to stroke occurrence, during which the patient often presents with severe pleural bleeding, which can have lifelong consequences if not immediately treated. We report a case of pulmonary arteriovenous malformation that was discovered incidentally in an adult patient who underwent non-contrast computed tomography. Misdiagnosis occurred, and transthoracic lung biopsy was performed. Complications were discovered late, and the patient underwent surgical pulmonary arteriovenous malformation removal and was treated for hemothorax.

COVID-19 Social Science and Public Engagement Action Research in Vietnam, Indonesia and Nepal (SPEAR): protocol for a mixed methods study exploring the experiences and impacts of COVID-19 for healthcare workers and vulnerable communities

Background: When the novel coronavirus - SARS-CoV-2 - started to spread globally, there was a call for social and behavioral scientists to conduct research to explore the wider socio-cultural contexts of coronavirus disease 2019 (COVID-19), to understand vulnerabilities, as well as to increase engagement within communities to facilitate adoption of public health measures. In this manuscript, we describe the protocol for a study conducted in Indonesia, Nepal, and Vietnam. In the study, we explore how the COVID-19 pandemic is affecting individuals and their communities. We focus on the wider health and economic impacts of COVID-19, in particular emerging and increased burden on mental health, as well as new or deepened vulnerabilities in the communities. The introduction of vaccines has added another layer of complexity and highlights differences in acceptance and inequalities around access.

No one left behind: risk communication to the street vendors during COVID-19 social distancing

Purpose>COVID-19 presents a serious and unprecedented challenge around the globe. Street vendors are the most vulnerable group during this pandemic regarding livelihood loss and contagion risk. This research aims to examine the roles of risk communication work in enhancing COVID-19 risk perceptions and adoption of COVID-19 preventive behaviors among street vendors.Design/methodology/approach>The data were collected from the street vendors in urban Vietnam. A binary probit model was used for analyzing the relationships among exposure to risk communication, risk perception and adoption of preventive behaviors.Findings>The analysis reveals the outreach of risk communication work to the street vendors. A rather large proportion of the respondents perceive high risks associated with COVID-19. All respondents adopt COVID-19 preventive behaviors;however, the proportion of regular adoption is moderate and even very low for most behaviors. Their frequent exposure to risk communication significantly raises their risk perceptions and encourages their regular adoption of preventive behaviors, particularly regarding the measures that are affordable and less detrimental to their livelihood.Originality/value>This research is among the first attempts to examine risk communication to the vulnerable group, how they perceive risks and the extent to which they adopt preventive behaviors during a public health crisis. This research draws some implications for risk communication and social welfare policies to obtain sustainable development goals.

Renewable energy consumption, nonrenewable energy consumption, CO2 emissions and economic growth in Vietnam

PurposeThis study intended to analyze the impact of nonrenewable energy consumption, renewable energy consumption, CO2 emissions on per capita income growth in Vietnam in the period 1990–2019.Design/methodology/approachThe present study adopts the technique of the Autoregressive Distributed Lag (ARDL) cointegration for the annual data collection of Vietnam.FindingsThe results of the study show that in the long term, nonrenewable energy consumption increases per capita income, but CO2 emissions reduce per capita income. In the short run, changes in nonrenewable energy consumption and renewable energy consumption promote per capita income growth in Vietnam. However, changes in nonrenewable energy consumption in the past have had a negative impact on the current income growth of Vietnamese people.Originality/valueThe current study provides new insights into the growth effect of nonrenewable energy consumption, renewable energy consumption and CO2 emissions. The papers suggests important implications to Vietnam in setting the long-run policies to boost the effect of energy consumption and CO2 emissions on growth in Vietnam in the coming time.

Hybrid simulation modelling of networks of heterogeneous care homes and the inter-facility spread of Covid-19 by sharing staff.

Although system dynamics [SD] and agent-based modelling [ABM] have individually served as effective tools to understand the Covid-19 dynamics, combining these methods in a hybrid simulation model can help address Covid-19 questions and study systems and settings that are difficult to study with a single approach. To examine the spread and outbreak of Covid-19 across multiple care homes via bank/agency staff and evaluate the effectiveness of interventions targeting this group, we develop an integrated hybrid simulation model combining the advantages of SD and ABM. We also demonstrate how we use several approaches adapted from both SD and ABM practices to build confidence in this model in response to the lack of systematic approaches to validate hybrid models. Our modelling results show that the risk of infection for residents in care homes using bank/agency staff was significantly higher than those not using bank/agency staff (Relative risk [RR] 2.65, 95% CI 2.57-2.72). Bank/agency staff working across several care homes had a higher risk of infection compared with permanent staff working in a single care home (RR 1.55, 95%CI 1.52-1.58). The RR of infection for residents is negatively correlated to bank/agency staff's adherence to weekly PCR testing. Within a network of heterogeneous care homes, using bank/agency staff had the most impact on care homes with lower intra-facility transmission risks, higher staff-to-resident ratio, and smaller size. Forming bubbles of care homes had no or limited impact on the spread of Covid-19. This modelling study has implications for policy makers considering developing effective interventions targeting staff working across care homes during the ongoing and future pandemics.

Preclinical Immune Response and Safety Evaluation of the Protein Subunit Vaccine Nanocovax for COVID-19.

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health concern. The development of vaccines with high immunogenicity and safety is crucial for controlling the global COVID-19 pandemic and preventing further illness and fatalities. Here, we report the development of a SARS-CoV-2 vaccine candidate, Nanocovax, based on recombinant protein production of the extracellular (soluble) portion of the spike (S) protein of SARS-CoV-2. The results showed that Nanocovax induced high levels of S protein-specific IgG and neutralizing antibodies in three animal models: BALB/c mouse, Syrian hamster, and a non-human primate (Macaca leonina). In addition, a viral challenge study using the hamster model showed that Nanocovax protected the upper respiratory tract from SARS-CoV-2 infection. Nanocovax did not induce any adverse effects in mice (Mus musculus var. albino) and rats (Rattus norvegicus). These preclinical results indicate that Nanocovax is safe and effective.

Analyzing and Forecasting Tourism Demand in Vietnam with Artificial Neural Networks

Vietnam has experienced a tourism expansion over the last decade, proving itself as one of the top tourist destinations in Southeast Asia. The country received more than 18 million international tourists in 2019, compared to only 1.5 million twenty-five years ago. Tourist spending has translated into rising employment and incomes for Vietnam’s tourism sector, making it the key driver to the socio-economic development of the country. Following the COVID-19 pandemic, only 3.8 million international tourists visited Vietnam in 2020, plummeting by 78.7% year-on-year. The latest outbreak in early summer 2021 made the sector continue to hit bottom. Although Vietnam’s tourism has suffered extreme losses, once the contagion is under control worldwide, the number of international tourists to Vietnam is expected to rise again to reach pre-pandemic levels in the next few years. First, the paper aims to provide a summary of Vietnam’s tourism characteristics with a special focus on international tourists. Next, the predictive capability of artificial neural network (ANN) methodology is examined with the datasets of international tourists to Vietnam from 2008 to 2020. Some ANN architectures are experimented with to predict the monthly number of international tourists to the country, including some lockdown periods due to the COVID-19 pandemic. The results show that, with the correct selection of ANN architectures and data from the previous 12 months, the best ANN models can be forecast for next month with a MAPE between 7.9% and 9.2%. As the method proves its forecasting accuracy, it would serve as a valuable tool for Vietnam’s policymakers and firm managers to make better investment and strategic decisions.

Direct Viral RNA Detection of SARS-CoV-2 and DENV in Inactivated Samples by Real-Time RT-qPCR: Implications for Diagnosis in Resource Limited Settings with Flavivirus Co-Circulation.

The RT-qPCR method remains the gold standard and first-line diagnostic method for the detection of SARS-CoV-2 and flaviviruses, especially in the early stage of viral infection. Rapid and accurate viral detection is a starting point in the containment of the COVID-19 pandemic and flavivirus outbreaks. However, the shortage of diagnostic reagents and supplies, especially in resource-limited countries that experience co-circulation of SARS-CoV-2 and flaviviruses, are limitations that may result in lesser availability of RT-qPCR-based diagnostic tests. In this study, the utility of RNA-free extraction methods was assessed for the direct detection of SARS-CoV-2 and DENV-2 in heat-inactivated or chemical-inactivated samples. The findings demonstrate that direct real-time RT-qPCR is a feasible option in comparison to conventional real-time RT-qPCR based on viral genome extraction-based methods. The utility of heat-inactivation and direct real-time RT-qPCR for SARS-CoV-2, DENV-2 viral RNA detection was demonstrated by using clinical samples of SARS-CoV-2 and DENV-2 and spiked cell culture samples of SARS-CoV-2 and DENV-2. This study provides a simple alternative workflow for flavivirus and SARS-CoV-2 detection that includes heat inactivation and viral RNA extraction-free protocols, with aims to reduce the risk of exposure during processing of SARS-CoV-2 biological specimens and to overcome the supply-chain bottleneck, particularly in resource limited settings with flavivirus co-circulation.

Discrepancies in Infectivity of Flavivirus and SARS-CoV-2 Clinical Samples: An Improved Assay for Infectious Virus Shedding and Viremia Assessment.

Infectivity and neutralizing antibody titers of flavivirus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are frequently measured using the conventional plaque assay. While the assay is useful in the determination of infectivity, conventional plaque assays generally possess lower sensitivity and are time-consuming compared to nucleic acid amplification tests. In this study, a microcrystalline cellulose (MCC), Avicel, was evaluated as an alternative to the conventional virus overlay medium, methylcellulose, for a plaque assay. The plaque assay was performed using dengue and COVID-19 clinical samples and laboratory-established flavivirus and SARS-CoV-2 strains. In virus titration of clinical samples, the plaques were significantly larger, and the virus titers were higher when Avicel MCC-containing overlay medium was used than with conventional methylcellulose overlay medium. In addition, for some clinical samples and laboratory virus strains, infectious particles were detected as plaques in the Avicel MCC-containing medium, but not in the conventional methylcellulose medium. The results suggest that the viremia titer determined using the new overlay medium containing Avicel MCC may better reflect the innate infectious and plaque-forming capabilities of clinical samples and better reflect virus infectivity.

Impact of visitation and cohorting policies to shield residents from covid-19 spread in care homes: an agent-based model.

BACKGROUND: This study examines the impact of visitation and cohorting policies as well as the care home population size upon the spread of COVID-19 and the risk of outbreak occurrence in this setting. METHODS: Agent-based modelling RESULTS: The likelihood of the presence of an outbreak in a care home is associated with the care home population size. Cohorting of residents and staff into smaller, self-contained units reduces the spread of COVID-19. Restricting the number of visitors to the care home to shield its residents does not significantly impact the cumulative number of infected residents and risk of outbreak occurrence in most scenarios. Only when the community prevalence where staff live is considerably lower than the prevalence where visitors live (the former prevalence is less than or equal to 30% of the latter), relaxing visitation increases predicted infections much more significantly than it does in other scenarios. Maintaining a low infection probability per resident-visitor contact helps reduce the effect of allowing more visitors into care homes. CONCLUSIONS: Our model predictions suggest that cohorting is effective in controlling the spread of COVID-19 in care homes. However, according to predictions shielding residents in care homes is not as effective as predicted in a number of studies that have modelled shielding of vulnerable population in the wider communities.

In Vitro Activity of a Novel Siderophore-Cephalosporin LCB10-0200 (GT-1), and LCB10-0200/Avibactam, against Carbapenem-Resistant Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa Strains at a Tertiary Hospital in Korea.

The siderophore-antibiotic conjugate LCB10-0200 (a.k.a. GT-1) has been developed to combat multidrug-resistant Gram-negative bacteria. In this study, the in vitro activity of LCB10-0200 and LCB10-0200/avibactam (AVI) has been investigated against carbapenem-resistant Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. Minimal inhibitory concentrations (MICs) of LCB10-0200, LCB10-0200/AVI, aztreonam, aztreonam/AVI, ceftazidime, ceftazidime/AVI, and meropenem were measured using the agar dilution method. Whole genome sequencing was performed using Illumina and the resistome was analyzed. LCB10-0200 displayed stronger activity than the comparator drugs in meropenem-resistant E. coli and K. pneumoniae, and the addition of AVI enhanced the LCB10-0200 activity to MIC ≤ 0.12 mg/L for 90.5% of isolates. In contrast, whereas LCB10-0200 alone showed potent activity against meropenem-resistant A. baumannii and P. aeruginosa at MIC ≤ 4 mg/L for 84.3% of isolates, the combination with AVI did not improve its activity. LCB10-0200/AVI was active against CTX-M-, SHV-, CMY-, and KPC- producing E. coli and K. pneumoniae, while LCB10-0200 alone was active against ADC-, OXA-, and VIM- producing A. baumannii and P. aeruginosa. Both LCB10-0200 and LCB10-0200/AVI displayed low activity against IMP- and NDM- producing strains. LCB10-0200 alone exhibited strong activity against selected strains. The addition of AVI significantly increased LCB10-0200 activity against carbapenem-resistant E. coli, K. pneumoniae.