Seroprevalence of anti-diphtheria toxoid antibody and implications for vaccination policy in Vietnam's South-central coast: a cross-sectional study.

BACKGROUND: Diphtheria is a re-emerging infectious disease and public health concern worldwide and in Vietnam with increasing cases in recent years. This study aimed to assess the anti-diphtheria toxoid antibodies status in Khanh Hoa Province and identify factors contributing to the vaccination policy in the south-central coast of Vietnam. METHODS: This was a cross-sectional study to evaluate the seroprevalence of anti-diphtheria toxoid antibodies among 1,195 participants, aged 5 - 40 years in Khanh Hoa Province, Vietnam. Immunoglobulin G antibody levels against diphtheria were detected using a commercial anti-diphtheria toxoid enzyme-linked immunosorbent assay (SERION ELISA classic Diphtheria Immunoglobulin G) and were categorized following the World Health Organization guidelines. RESULTS: The mean anti-diphtheria toxoid antibody levels were 0.07 IU/ml (95% Confidence Interval: 0.07-0.08). Anti-diphtheria toxoid antibody levels were found to be associated with age and history of diphtheria vaccination. The 5-15 years age group had the highest levels (0.09 IU/ml), while the older age group had the lowest antibody level (p < 0.001). Individuals who received three doses (adjusted Odds ratio: 2.34, 95%CI: 1.35 - 4.07) or 4+ doses (adjusted Odds ratio: 2.45, 95%CI: 1.29 - 4.64) had a higher antibody level compared to those who received only one dose regardless of age. CONCLUSION: It is crucial to promote routine vaccination coverage to over 95% for children under one year of age with three primary doses of the diphtheria-containing vaccine, including additional doses at 18 months and 7 years of age. Booster doses should be promoted and administered to adolescents and adults every 10 years.

Progress in Sensors for Monitoring Reinforcement Corrosion in Reinforced Concrete Structures-A Review.

Non-destructive monitoring methods and continuous monitoring systems based on them are crucial elements of modern systems for the management and maintenance of assets which include reinforced concrete structures. The purpose of our study was to summarise the data on the most common sensors and systems for the non-destructive monitoring of reinforced concrete structures developed over the past 20 years. We considered systems based on electrochemical (potentiometry, methods related to polarisation) and physical (electromagnetic and ultrasonic waves, piezoelectric effect, thermography) examination methods. Special focus is devoted to the existing sensors and the results obtained using these sensors, as well as the advantages and disadvantages of their setups or other equipment used. The review considers earlier approaches and available commercial products, as well as relatively new sensors which are currently being tested.

Navigating critical barriers for green bond markets using A fuzzy multi-criteria decision-making model: Case study in Vietnam.

As potent financial instruments channeling capital into climate and environmental projects, green bonds' issuance is frustrated by myriad obstacles. Therefore, this study aims to explore the critical barriers to green bond issuance in Vietnam. This study elucidates the salient barriers by utilizing an integrated multi-criteria decision-making methodology synthesizing the Fuzzy set theory-based Delphi, Decision-Making Trial and Evaluation Laboratory (DEMATEL), and DEMATEL-based Analytic Network Process (DANP). An extensive literature review of green bonds delineates five key dimensions related to impediments: Policy, Market, Financial, Capacity, and Awareness, with 38 discrete indicators representing potential obstacles. Firstly, employing a Fuzzy Delphi survey of 16 experts, 32 indicators are distilled for further analysis. Then, Fuzzy DEMATEL modeling evaluates the interrelationships and interactions among barriers. Finally, DANP is applied to obtain the relative importance of key barriers. Results unveil the five most formidable barriers as a weak regulatory framework and infrastructure (PO1), Limited availability of green bond issuance guidelines and templates (PO2), Insufficient incentives or tax benefits for green bond issuers (PO3), Limited coordination and alignment with international green bond standards (PO5), Lack of investor confidence in the quality and credibility of green projects (AW4), and Capacity constraints among issuers, particularly in smaller organisations or government agencies (CA1). The research contributes to the broader literature on green finance and offers valuable insights for promoting sustainable finance practices in Vietnam and other developing economies.

Polysiloxane Coatings Biodeterioration in Nature and Laboratory.

Objects and structures made of organic glass require protection from damage caused by external factors. Light, humidity, temperature, dust pollution and, undoubtedly, microorganisms lead to the deterioration of optical and mechanical properties. Polysiloxane-based protective coatings, consisting of silicon-oxygen backbones linked together with organic side groups attached to the silicon atoms, are widely used. However, the polysiloxane coatings themselves also cannot avoid deterioration during operation that implies the constant development of new protective materials. Here, we created a new cross-linked polysiloxane that covers organic glasses to enhance their resistance to aggressive external factors, and investigated its own resistance to damage induced by micromycetes in natural tropical conditions and in the laboratory. It has been established that the surface of coatings in the tropics is prone to fouling with micromycetes, mainly of the genera Aspergillus and Penicillium, which produce oxalic, malic, lactic, and citric acids contributing to the biodeterioration of polysiloxane. The testing of monolithic polycarbonate, polymethyl methacrylate, and triplex coated with polysiloxane showed that they retained significant resistance to abrasion and transparency at a level of more than 90% under aggressive natural conditions. Under artificial laboratory conditions, the infection of samples with micromycete spores also revealed their growth on surfaces and a similar trend of damage.

Water treatment and re-use at temporary events using a mobile constructed wetland and drinking water production system.

Temporary events such as music festivals are often organized in places that are not connected to a sewage network. As such, the waste (water) generated and discharged can place a heavy burden on the environment. A mobile vertical flow constructed wetland (MCW) with an area of 15 m2 was constructed, optimized and operated for three years treating grey water (GW) as well as grey and black water (GW + BW) at different festival locations to tackle this problem. During the initial development phase, the appropriate influent type (GW and/or GW + BW) was determined and challenge tests with pre-settled diluted domestic waste water (mimicking GW) were carried out to determine the maximal allowable loading rate. The MCW was able to treat both types of water. However, for further experiments GW was selected as the discharge limits could not be met when treating GW + BW. The challenge tests demonstrated that the MCW could be operated at a maximal allowable hydraulic loading rate of 1.1 m3·m-2·d-1, corresponding to mass loading rates of 68 gTSS·m-2·d-1, 160 gCOD·m-2·d-1 and 137 gBOD·m-2·d-1. During treatment of GW, the MCW achieved effluent concentrations for respectively chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS) and total phosphorus (TP) of 43 mg·L-1, 16 mg·L-1, 2.7 mg·L-1 and 1.7 mgP·L-1. This corresponds to a removal of 90% (COD), 95% (BOD), 97% (TSS) and 76% (TP) respectively. Total nitrogen removal was 25% (from 45 mgN·L-1 to 34 mgN·L-1) as particularly denitrification was not complete. As a further development, the MCW was coupled to a drinking water treatment system using ultrafiltration and reverse osmosis (UF-RO) membranes to produce potable water on site. The drinking water system produced potable water that met the legislative criteria. As such, a sustainable and mobile water treatment system aiming at producing potable water at temporary events was demonstrated.