Rapid identification of SARS-CoV-2 strains via isothermal enzymatic recombinase amplification and nanopore sequencing.

Surveillance of the SARS-CoV-2 genome has become a crucial technique in the management of COVID-19, aiding the pandemic response and supporting effective public health interventions. Typically, whole-genomic sequencing is used along with PCR-based target enrichment techniques to identify SARS-CoV-2 variants, which is a complicated and time-consuming process that requires central laboratory facilities. Thus, there is an urgent need to develop rapid and cost-effective tools for precise on-site detection and identification of SARS-CoV-2 strains. In this study, we demonstrate the rapid diagnosis of COVID-19 and identification of SARS-CoV-2 variants by amplification and sequencing of the entire SARS-CoV-2 S gene using isothermal enzymatic recombinase amplification combined with the advanced Oxford nanopore sequencing technique. The entire procedure, from sampling to sequencing, takes less than 8 hours and can be performed with limited resources. The newly developed method has noteworthy implications for examining the transmission dynamics of the virus, detecting novel genetic variants, and assessing the effect of mutations on diagnostic approaches, antiviral treatments, and vaccines.

Mother-to-Child Transmission of HBV Infection by Preventive Interventions in Southern Vietnam's Hospitals.

INTRODUCTION: The World Health Organization (WHO) recommends tenofovir disoproxil fumarate (TDF) for pregnant women with hepatitis B virus (HBV) presenting with HBV DNA levels of 106 copies/mL or more to hinder mother-to-child transmission (MTCT). Moreover, it is suggested that neonates of HBV-infected mothers receive an HBV vaccine birth dose within 24 hours of birth to mitigate transmission risk. METHODOLOGY: The study included 661 HBV-infected pregnant women and 316 infants from 3 hospitals in Southern Vietnam between October 2019 and November 2020. Infants were classified on the basis of their mothers' TDF prophylaxis into I-TDF (+) group (107 infants) whose mothers received TDF; I-TDF (-) group (56 infants) whose mothers missed TDF; and I-NTDF group (153 infants) whose mothers did not necessitate TDF. Almost all infants received an HBV vaccine birth dose with HBIG administered on the basis of parents' financial standing. RESULTS: MTCT was found in 2.2% of the cases. The respective MTCT rates for I-TDF (+), I-TDF (-), and I-NTDF groups were 2.8%, 5.4%, and 0.7%. Immune response rates to the HBV vaccination in the total cohort, I-TDF (+), I-TDF (-), and I-NTDF groups, were 88.6%, 87.9%, 85.7%, and 90.2%, respectively. Vaccinated infants exhibited a statistically lower risk of HBV infection postbirth (aRR = 0.1; 95% confidence interval, 0.0-0.6; P = .01). CONCLUSION: TDF can equate the MTCT risk in pregnant women with HBV DNA levels of 106 copies/mL or more to those with lower levels. Early administration of the HBV vaccine postbirth also effectively curtails MTCT. Thus, expanding TDF prophylaxis and vaccine coverage is pivotal to impede MTCT.

Construction of S-scheme CdS/g-C3N4 nanocomposite with improved visible-light photocatalytic degradation of methylene blue.

Within moderate band gap, g-C3N4 and CdS are both promising visible light driven photocatalysts. However, their intrinsic high recombination rate of photo-induced electron-hole pairs along with the poor susceptibility in photocorrosion of CdS is main limitations hindering their practical application. In this study, the CdS/g-C3N4 composites with various weight ratios of CdS to g-C3N4 were solvothermal prepared from the dispersion of components, g-C3N4 and CdS, in ethanol. The physicochemical characterizations demonstrate the success in the fabrication of well-dispersed CdS nanoparticles in the g-C3N4 matrix. The enhanced photocatalytic activity of the g-C3N4/CdS composite over the degradation of methylene blue under visible light was ascribed to the effective photo-induced electron-hole separation via the step scheme (S-scheme) pathway in which the main contribution of high oxidative hydroxyl radicals (•OH) was demonstrated. Furthermore, via S-scheme model, we also clarify the depletion of photo-induced holes on CdS which is ascribed as the reason for improvement in resistance to photocorrosion of composites.

Correlation Between the Amount of Extracellular Polymeric Substances and the Survival Rate to Freeze-Drying of Probiotics.

To demonstrate that the amount of extracellular polymeric substances (EPS) and the freeze-dried viability of probiotics are correlated. Three strains of probiotics including Lactiplantibacillus plantarum, Lactobacillus acidophilus, and Bifidobacterium bifidum were subjected to environmental challenges, such as temperature, pH, and carbon dioxide. The results indicated that the challenges could stimulate the EPS synthesis of the probiotics. The experimental correlation between the amount of synthesized EPS and the freeze-dried survival rate was also analyzed, and the viability of each of the three strains was represented by the following functions in which the equation of L. plantarum is y = - 0.0336x2 + 2.7059x - 14.849 with R2 = 0.9699, the B. bifidum's equation is y = - 0.0554x2 + 2.6243x - 13.654 with R2 = 0.9554, and the L. acidophilus's one was y = 0.0346x2 + 0.5862x - 9.1339 with R2 = 0.9733. This could be a new approach to determining the freeze-dried viability of probiotic strains based on the measured EPS content.

Research and Development Prospects for Sugarcane Industry in Vietnam.

Sugarcane is one of the most important industrial crops in Vietnam and covers a total of 127,000 hectares of plantation area. In the season 2020-2021, Vietnam has produced 0.763 million tons of sugar (accounting for 0.34% total world sugar production). A current sugarcane production of 7.498 million tons is being used mainly for sugar production for direct consumption, ethanol production, bio-electricity and fertilization. To ensure crop sustainability, various policies and plans have been implemented. Crop breeding and zoning improvement programme significantly influence sugarcane production and sugar yield. Over 25 years since the programme "one million ton of sugar" was promoted, Vietnam currently possesses 25 sugar mills with a total capacity of 110,000 tons of sugarcane per day. Major problems of sugarcane industry as well as research and development have been discussed in this review. Recent research and development work focused on the added values of co-products to ensure sustainability of the sugarcane industry. Molasses will be used for ethanol production, and bagasse is used as the biomass for the alternative energy. Sugarcane and sugar would be the main feedstocks for those bio-economy growths in Vietnam. To keep the sustainable development of the sugar industry, and to meet the demand of the food and non-food requirements, it is necessary to upgrade the sugar value chain through the adoption and the development of co-products of the sugar industry.

Transcriptional memory of cells of origin overrides ß-catenin requirement of MLL cancer stem cells.

While ß-catenin has been demonstrated as an essential molecule and therapeutic target for various cancer stem cells (CSCs) including those driven by MLL fusions, here we show that transcriptional memory from cells of origin predicts AML patient survival and allows ß-catenin-independent transformation in MLL-CSCs derived from hematopoietic stem cell (HSC)-enriched LSK population but not myeloid-granulocyte progenitors. Mechanistically, ß-catenin regulates expression of downstream targets of a key transcriptional memory gene, Hoxa9 that is highly enriched in LSK-derived MLL-CSCs and helps sustain leukemic self-renewal. Suppression of Hoxa9 sensitizes LSK-derived MLL-CSCs to ß-catenin inhibition resulting in abolishment of CSC transcriptional program and transformation ability. In addition, further molecular and functional analyses identified Prmt1 as a key common downstream mediator for ß-catenin/Hoxa9 functions in LSK-derived MLL-CSCs. Together, these findings not only uncover an unexpectedly important role of cells of origin transcriptional memory in regulating CSC self-renewal, but also reveal a novel molecular network mediated by ß-catenin/Hoxa9/Prmt1 in governing leukemic self-renewal.

Survival after out-of-hospital cardiac arrest, Viet Nam: multicentre prospective cohort study.

OBJECTIVE: To investigate factors associated with survival after out-of-hospital cardiac arrest in Viet Nam. METHODS: We did a multicentre prospective observational study of people (> 18 years) presenting with out-of-hospital cardiac arrest (not caused by trauma) to three tertiary hospitals in Viet Nam from February 2014 to December 2018. We collected data on characteristics, management and outcomes of patients with out-of-hospital cardiac arrest and compared these data by type of transportation to hospital and survival to hospital admission. We assessed factors associated with survival to admission to and discharge from hospital using logistic regression analysis. FINDINGS: Of 590 eligible people with out-of-hospital cardiac arrest, 440 (74.6%) were male and the mean age was 56.1 years (standard deviation: 17.2). Only 24.2% (143/590) of these people survived to hospital admission and 14.1% (83/590) survived to hospital discharge. Most cardiac arrests (67.8%; 400/590) occurred at home, 79.4% (444/559) were witnessed by bystanders and 22.3% (124/555) were given cardiopulmonary resuscitation by a bystander. Only 8.6% (51/590) of the people were taken to hospital by the emergency medical services and 32.2% (49/152) received pre-hospital defibrillation. Pre-hospital defibrillation (odds ratio, OR: 3.90; 95% confidence interval, CI: 1.54-9.90) and return of spontaneous circulation in the emergency department (OR: 2.89; 95% CI: 1.03-8.12) were associated with survival to hospital admission. Hypothermia therapy during post-resuscitation care was associated with survival to discharge (OR: 5.44; 95% CI: 2.33-12.74). CONCLUSION: Improvements are needed in the emergency medical services in Viet Nam such as increasing bystander cardiopulmonary resuscitation and public access defibrillation, and improving ambulance and post-resuscitation care.

Expression of genes involved in exopolysaccharide synthesis in Lactiplantibacillus plantarum VAL6 under environmental stresses.

Environmental factors can alter exopolysaccharide biosynthesis in lactic acid bacteria (LAB). To further clarify this potential relationship, the mRNA expression of genes involved in exopolysaccharide synthesis such as glmU, pgmB1, cps4E, cps4F, cps4J, and cps4H in Lactiplantibacillus plantarum VAL6 under different conditions including temperature, pH, sodium chloride (NaCl), and carbon dioxide (CO2) intensification culture was studied. The transcriptomic data revealed that the exposure of L. plantarum VAL6 at pH 3 increased the expression level of cps4H but decreased the expression levels of pgmB1 and cps4E. Under pH 8, cps4F and cps4E were significantly upregulated, whereas pgmB1 was downregulated. Similarly, the expression levels of cps4F, cps4E, and cps4J increased sharply under stresses at 42 or 47 °C. In the case of NaCl stress, glmU, pgmB1, cps4J, and cps4H were downregulated in exposure to NaCl at 7 and 10% concentrations while cps4E and cps4F were upregulated at 1 h of 10%-NaCl treatment and at 5 h of 4%-NaCl treatment. Remarkably, CO2 intensification culture stimulated the expression of all tested genes. In addition, simultaneous changes in expression of cps4E and cps4F under environmental challenges may elicit the possibility of an association between the two genes. These findings indicated that the expression level of eps genes is responsible for changes in the yield and monosaccharide composition of exopolysaccharides under environmental stresses.

Multi-Robot 2.5D Localization and Mapping Using a Monte Carlo Algorithm on a Multi-Level Surface.

Most indoor environments have wheelchair adaptations or ramps, providing an opportunity for mobile robots to navigate sloped areas avoiding steps. These indoor environments with integrated sloped areas are divided into different levels. The multi-level areas represent a challenge for mobile robot navigation due to the sudden change in reference sensors as visual, inertial, or laser scan instruments. Using multiple cooperative robots is advantageous for mapping and localization since they permit rapid exploration of the environment and provide higher redundancy than using a single robot. This study proposes a multi-robot localization using two robots (leader and follower) to perform a fast and robust environment exploration on multi-level areas. The leader robot is equipped with a 3D LIDAR for 2.5D mapping and a Kinect camera for RGB image acquisition. Using 3D LIDAR, the leader robot obtains information for particle localization, with particles sampled from the walls and obstacle tangents. We employ a convolutional neural network on the RGB images for multi-level area detection. Once the leader robot detects a multi-level area, it generates a path and sends a notification to the follower robot to go into the detected location. The follower robot utilizes a 2D LIDAR to explore the boundaries of the even areas and generate a 2D map using an extension of the iterative closest point. The 2D map is utilized as a re-localization resource in case of failure of the leader robot.

Robust Position Control of an Over-actuated Underwater Vehicle under Model Uncertainties and Ocean Current Effects Using Dynamic Sliding Mode Surface and Optimal Allocation Control.

Underwater vehicles (UVs) are subjected to various environmental disturbances due to ocean currents, propulsion systems, and un-modeled disturbances. In practice, it is very challenging to design a control system to maintain UVs stayed at the desired static position permanently under these conditions. Therefore, in this study, a nonlinear dynamics and robust positioning control of the over-actuated autonomous underwater vehicle (AUV) under the effects of ocean current and model uncertainties are presented. First, a motion equation of the over-actuated AUV under the effects of ocean current disturbances is established, and a trajectory generation of the over-actuated AUV heading angle is constructed based on the line of sight (LOS) algorithm. Second, a dynamic positioning (DP) control system based on motion control and an allocation control is proposed. For this, motion control of the over-actuated AUV based on the dynamic sliding mode control (DSMC) theory is adopted to improve the system robustness under the effects of the ocean current and model uncertainties. In addition, the stability of the system is proved based on Lyapunov criteria. Then, using the generalized forces generated from the motion control module, two different methods for optimal allocation control module: the least square (LS) method and quadratic programming (QP) method are developed to distribute a proper thrust to each thruster of the over-actuated AUV. Simulation studies are conducted to examine the effectiveness and robustness of the proposed DP controller. The results show that the proposed DP controller using the QP algorithm provides higher stability with smaller steady-state error and stronger robustness.

An Advanced Noise Reduction and Edge Enhancement Algorithm.

Complementary metal-oxide-semiconductor (CMOS) image sensors can cause noise in images collected or transmitted in unfavorable environments, especially low-illumination scenarios. Numerous approaches have been developed to solve the problem of image noise removal. However, producing natural and high-quality denoised images remains a crucial challenge. To meet this challenge, we introduce a novel approach for image denoising with the following three main contributions. First, we devise a deep image prior-based module that can produce a noise-reduced image as well as a contrast-enhanced denoised one from a noisy input image. Second, the produced images are passed through a proposed image fusion (IF) module based on Laplacian pyramid decomposition to combine them and prevent noise amplification and color shift. Finally, we introduce a progressive refinement (PR) module, which adopts the summed-area tables to take advantage of spatially correlated information for edge and image quality enhancement. Qualitative and quantitative evaluations demonstrate the efficiency, superiority, and robustness of our proposed method.

Survival after traumatic out-of-hospital cardiac arrest in Vietnam: a multicenter prospective cohort study.

BACKGROUND: Pre-hospital services are not well developed in Vietnam, especially the lack of a trauma system of care. Thus, the prognosis of traumatic out-of-hospital cardiac arrest (OHCA) might differ from that of other countries. Although the outcome in cardiac arrest following trauma is dismal, pre-hospital resuscitation efforts are not futile and seem worthwhile. Understanding the country-specific causes, risk, and prognosis of traumatic OHCA is important to reduce mortality in Vietnam. Therefore, this study aimed to investigate the survival rate from traumatic OHCA and to measure the critical components of the chain of survival following a traumatic OHCA in the country. METHODS: We performed a multicenter prospective observational study of patients (> 16 years) presenting with traumatic OHCA to three central hospitals throughout Vietnam from February 2014 to December 2018. We collected data on characteristics, management, and outcomes of patients, and compared these data between patients who died before hospital discharge and patients who survived to discharge from the hospital. RESULTS: Of 111 eligible patients with traumatic OHCA, 92 (82.9%) were male and the mean age was 39.27 years (standard deviation: 16.38). Only 5.4% (6/111) survived to discharge from the hospital. Most cardiac arrests (62.2%; 69/111) occurred on the street or highway, 31.2% (29/93) were witnessed by bystanders, and 33.7% (32/95) were given cardiopulmonary resuscitation (CPR) by a bystander. Only 29 of 111 patients (26.1%) were taken by the emergency medical services (EMS), 27 of 30 patients (90%) received pre-hospital advanced airway management, and 29 of 53 patients (54.7%) were given resuscitation attempts by EMS or private ambulance. No significant difference between patients who died before hospital discharge and patients who survived to discharge from the hospital was found for bystander CPR (33.7%, 30/89 and 33.3%, 2/6, P > 0.999; respectively) and resuscitation attempts (56.3%, 27/48, and 40.0%, 2/5, P = 0.649; respectively). CONCLUSION: In this study, patients with traumatic OHCA presented to the ED with a low rate of EMS utilization and low survival rates. The poor outcomes emphasize the need for increasing bystander first-aid, developing an organized trauma system of care, and developing a standard emergency first-aid program for both healthcare personnel and the community.

Therapeutic effect of prolonged testosterone pretreatment in women with poor ovarian response: A randomized control trial.

PURPOSE: This study compared the therapeutic effects of transdermal testosterone gel (TTG) application at 4 and 6 weeks before controlled ovarian hyperstimulation (COH) in women with poor ovarian response (POR). METHODS: In this randomized control trial, infertile women with POR who underwent in vitro fertilization (IVF) were recruited and randomly classified into 4 week (n = 42) and 6 week (n = 38) TTG treatment groups and control group (n = 42). The primary outcome was total number of retrieved mature oocytes. The secondary outcomes were the biochemical pregnancy rate, clinical pregnancy rate, and ongoing pregnancy rate. RESULTS: No significant differences were observed in the number of oocytes retrieved, mature oocytes and embryos between all groups. Human chorionic gonadotropin (hCG) positive, clinical, and ongoing pregnancy rates were significantly higher in the TTG pretreatment groups than in the control group but no differences were observed between the 4- and 6 week groups. CONCLUSIONS: Applying TTG in infertile women with POR may ameliorate the outcomes of IVF. The extended application of TTG to 6 weeks did not improve the response to ovarian stimulation regarding the number of retrieved oocytes nor pregnancy outcomes compared to the 4 week pretreatment.

Neutralizing Antibodies against Enteroviruses in Patients with Hand, Foot and Mouth Disease.

Hand, foot and mouth disease (HFMD) is an emerging infection with pandemic potential. Knowledge of neutralizing antibody responses among its pathogens is essential to inform vaccine development and epidemiologic research. We used 120 paired-plasma samples collected at enrollment and >7 days after the onset of illness from HFMD patients infected with enterovirus A71 (EV-A71), coxsackievirus A (CVA) 6, CVA10, and CVA16 to study cross neutralization. For homotypic viruses, seropositivity increased from <60% at enrollment to 97%-100% at follow-up, corresponding to seroconversion rates of 57%-93%. Seroconversion for heterotypic viruses was recorded in only 3%-23% of patients. All plasma samples from patients infected with EV-A71 subgenogroup B5 could neutralize the emerging EV-A71 subgenogroup C4. Collectively, our results support previous reports about the potential benefit of EV-A71 vaccine but highlight the necessity of multivalent vaccines to control HFMD.

Plans for Nationwide Serosurveillance Network in Vietnam.

In recent years, serosurveillance has gained momentum as a way of determining disease transmission and immunity in populations, particularly with respect to vaccine-preventable diseases. At the end of 2017, the Oxford University Clinical Research Unit and the National Institute of Hygiene and Epidemiology held a meeting in Vietnam with national policy makers, researchers, and international experts to discuss current seroepidemiologic projects in Vietnam and future needs and plans for nationwide serosurveillance. This report summarizes the meeting and the plans that were discussed to set up nationwide serosurveillance in Vietnam.

Low-cost and versatile analytical tool with purpose-made capillary electrophoresis coupled to contactless conductivity detection: Application to antibiotics quality control in Vietnam.

In this study, the development of our purpose-made capacitively coupled contactless conductivity detection (C4 D) for CE is reported. These systems have been employed as a simple, versatile, and cost-effective analytical tool. CE-C4 D devices, whose principle is based on the control of the ion movements under an electrical field, can be constructed even with a modest financial budget and limited infrastructure. A featured application was developed for quality control of antimicrobial drugs using CE-C4 D, with most recent work on determination of aminoglycoside and glycopeptide antibiotics being communicated. For aminoglycosides, the development of CE-C4 D methods was adapted to two categories. The first one includes drugs (liquid or powder form) for intravenous injection, containing either amikacin, streptomycin, kanamycin A, or kanamycin B. The second one covers drugs for eye drops (liquid or ointment form), containing either neomycin, tobramycin, or polymyxin. The CE-C4 D method development was also made for determination of some popular glycopeptide antibiotics in Vietnam, including vancomycin and teicoplanin. The best detection limit achieved using the developed CE-C4 D methods was 0.5 mg/L. Good agreement between results from CE-C4 D and the confirmation method (HPLC- Photometric Diode Array ) was achieved, with their result deviations less than 8% and 13% for aminoglycoside and glycopeptide antibiotics, respectively.

A preliminary investigation of 942 organic micro-pollutants in the atmosphere in waste processing and urban areas, northern Vietnam: Levels, potential sources, and risk assessment.

Of 942 organic micro-pollutants screened, 167 compounds were detected at least once in the atmosphere in some primitive waste processing sites and an urban area in northern Vietnam by using a polyurethane foam-based passive air sampling (PUF-PAS) method and an Automated Identification and Quantification System with a Database (AIQS-DB) for GC-MS. Total concentrations of organic pollutants were higher in samples collected from an urban area of Hanoi city (2300-2600 ng m-3) as compared with those from an end-of-life vehicle (ELV) dismantling area in Bac Giang (900-1700 ng m-3) and a waste recycling cooperative in Thai Nguyen (870-1300 ng m-3). Domestic chemicals (e.g., n-alkanes, phthalate ester plasticizers, and synthetic phenolic antioxidants) dominated the organic pollutant patterns in all the samples, especially in the urban area. Pesticides (e.g., permethrins, chlorpyrifos, and propiconazole) were found in the atmosphere around the ELV sites at more elevated concentrations than the other areas. Levels of polycyclic aromatic hydrocarbons and their derivatives in the Bac Giang and Thai Nguyen facilities were significantly higher than those measured in Hanoi urban houses, probably due to the waste processing activities. Daily intake doses of organic pollutants via inhalation were estimated for waste processing workers and urban residents. This study shall provide preliminary data on the environmental occurrence, potential emission sources, and effects of multiple classes of organic pollutants in urban and waste processing areas in northern Vietnam.

The Use of Magnetic Orientation as a Pinning Modality for Investigation of Photon-Magnon Interactions in Magnetic Nanoparticle Systems.

In this work, an experimental setup to study the dependence of a visible-light transmission through a magnetic granular film on the magnetic field direction was presented. The results measured the transmission (T) of the visible light, with the wavelengths λ were in the range from 560 to 695 nm, by the magnetic nanogranular films Cox-(Al2O3)100-x system, with Co compositions are x = 10 ÷ 45 at.%, as a function of the magnetic field direction were reported. These investigations were carried out under an external magnetic field of H = 400 Oe, which directs to the normal of the sample surface by an angle varied in the range of φ = 0° ÷ 45°, to magnetize the magnetization direction of all the Co particles following this direction. Consequently, the angle φ between the magnetization direction with the incident-light direction, which sets as the optical axis of the system and always keeps fixedly to the normal of the sample surface, is established. The experimental results showed the different dependencies of T on the angle φ, the magnetic field H, the Co composition x, and the wavelength λ. These dependencies attributed to a behavior that relates to so-called photon-magnon interaction.

Evolution and Spatiotemporal Dynamics of Enterovirus A71 Subgenogroups in Vietnam.

Background: Enterovirus A71 (EV-A71) is the major cause of severe hand, foot, and mouth disease and viral encephalitis in children across the Asia-Pacific region, including in Vietnam, which has experienced a high burden of disease in recent years. Multiple subgenogroups (C1, C4, C5, and B5) concurrently circulate in the region with a large variation in epidemic severity. The relative differences in their evolution and epidemiology were examined within Vietnam and globally. Methods: A total of 752 VP1 gene sequences were analyzed (413 generated in this study combined with 339 obtained from GenBank), collected from patients in 36 provinces in Vietnam during 2003-2013, along with epidemiological metadata. Globally representative VP1 gene datasets of subgenogroups were used to coestimate time-resolved phylogenies and relative genetic diversity to infer virus origins and regional transmission network. Results: Despite frequent virus migration between countries, the highest genetic diversity of individual subgenogroups was maintained independently for several years in specific Asian countries representing genogroup-specific sources of EV-A71 diversity. Conclusion: This study highlights a persistent transmission network of EV-A71, with specific Asian countries seeding other countries in the region and beyond, emphasizing the need for improved EV-A71 surveillance and detailed genetic and antigenic characterization.

Polybrominated diphenyl ethers in plastic products, indoor dust, sediment and fish from informal e-waste recycling sites in Vietnam: a comprehensive assessment of contamination, accumulation pattern, emissions, and human exposure.

Residue concentrations of polybrominated diphenyl ethers (PBDEs) in different kinds of samples including consumer products, indoor dust, sediment and fish collected from two e-waste recycling sites, and some industrial, urban and suburban areas in Vietnam were determined to provide a comprehensive assessment of the contamination levels, accumulation pattern, emission potential and human exposure through dust ingestion and fish consumption. There was a large variation of PBDE levels in plastic parts of obsolete electronic equipment (from 1730 to 97,300 ng/g), which is a common result observed in consumer plastic products reported elsewhere. PBDE levels in indoor dust samples collected from e-waste recycling sites ranged from 250 to 8740 ng/g, which were markedly higher than those in industrial areas and household offices. Emission rate of PBDEs from plastic parts of disposed electronic equipment to dust was estimated to be in a range from 3.4 × 10-7 to 1.2 × 10-5 (year-1) for total PBDEs and from 2.9 × 10-7 to 7.2 × 10-6 (year-1) for BDE-209. Some fish species collected from ponds in e-waste recycling villages contained elevated levels of PBDEs, especially BDE-209, which were markedly higher than those in fish previously reported. Overall, levels and patterns of PBDE accumulation in different kinds of samples suggest significant emission from e-waste sites and that these areas are potential sources of PBDE contamination. Intakes of PBDEs via fish consumption were generally higher than those estimated through dust ingestion. Intake of BDE-99 and BDE-209 through dust ingestion contributes a large proportion due to higher concentrations in dust and fish. Body weight normalized daily intake through dust ingestion estimated for the e-waste recycling sites (0.10-3.46 ng/day/kg body wt.) were in a high range as compared to those reported in other countries. Our results highlight the potential releases of PBDEs from informal recycling activities and the high degree of human exposure and suggest the need for continuous investigations on environmental pollution and toxic impacts of e-waste-related hazardous chemicals.