Expression of SUMO and NF-κB genes in hepatitis B virus-associated hepatocellular carcinoma patients: An observational study.

Alterations in signaling pathways and modulation of cell metabolism are associated with the pathogenesis of cancers, including hepatocellular carcinoma (HCC). Small ubiquitin-like modifier (SUMO) proteins and NF-κB family play major roles in various cellular processes. The current study aims to determine the expression profile of SUMO and NF-κB genes in HCC tumors and investigate their association with the clinical outcome of HCC. The expression of 5 genes - SUMO1, SUMO2, SUMO3, NF-κB p65, and NF-κB p50 - was quantified in tumor and adjacent non-tumor tissues of 58 HBV-related HCC patients by real-time quantitative PCR and was analyzed for the possible association with clinical parameters of HCC. The expression of SUMO2 was significantly higher in HCC tumor tissues compared to the adjacent non-tumor tissues (P = .01), while no significant difference in SUMO1, SUMO3, NF-κB p65, and NF-κB p50 expression was observed between HCC tumor and non-tumor tissues (P > .05). In HCC tissues, a strong correlation was observed between the expression of SUMO2 and NF-κB p50, between SUMO3 and NF-κB p50, between SUMO3 and NF-κB p65 (Spearman rho = 0.83; 0.82; 0.772 respectively; P < .001). The expression of SUMO1, SUMO2, SUMO3, NF-κB p65, and NF-κB p50 was decreased in grade 3 compared to grades 1 and 2 in HCC tumors according to the World Health Organization grades system. Our results highlighted that the SUMO2 gene is upregulated in tumor tissues of patients with HCC, and is related to the development of HCC, thus it may be associated with the pathogenesis of HCC.

Mechanical, Durability, and Microstructure Assessment of Wastepaper Fiber-Reinforced Concrete Containing Metakaolin.

This study evaluates the potential use of discarded plasterboard paper as fibers from buildings to reinforce concrete. Various concentrations of wastepaper fibers (0.5%, 1%, 1.5%, 2%, and 2.5% by weight of the binder) were investigated in this research. To mitigate the water absorption effect of the paper fibers, metakaolin was employed as a partial cement replacement. The results demonstrate that the inclusion of the wastepaper fiber enhances the mechanical and durability performance of the concrete. The optimal fiber proportion was identified as 1%, leading to a 29% increase in the compressive strength, a 38% increase in the splitting tensile strength, a 12% decrease in the water absorption, and a 23% decrease in the drying shrinkage with respect to the concrete containing 20% metakaolin. However, exceeding this optimal fiber content results in decreased mechanical and durability properties due to the fiber agglomeration and non-uniform fiber distribution within the concrete matrix. Based on the microstructural analysis, the improved performance of the concrete is ascribed to decreased porosity, more refined pore structure, and reduced propagation of microcracks within the concrete matrix in the presence of wastepaper fiber. According to the results, concrete containing 20% metakaolin and 1% wastepaper fiber exhibits durability and mechanical properties comparable to those of the traditional concrete. This finding highlights the significant promise of reducing dependency on conventional cement and incorporating suitable recycled materials, such as discarded plasterboard, and secondary by-products like metakaolin. Such a strategy encourages the preservation of resources, reduction in carbon dioxide emissions, and a decrease in the ecological footprint resulting from concrete production.

Epidural injection-related pneumorrhachis: A case report with cauda equina syndrome.

Pneumorrhachis (PR) is an uncommon condition characterized by the accumulation of air within the spinal canal. This finding may occur due to various causes, mostly after trauma and medical procedures. It can manifest with various features depending on the underlying cause, the location, and the extent of the air trapped. Clinically, the symptoms in affected patients can span a spectrum, ranging from being asymptomatic to manifesting as radiculopathies resulting from compression. The pneumorrhachis-related cauda equina syndrome is incredibly rare and typically appears as a large volume of air causing compression or irritation of the nerve roots in the lower spinal cord. In this report, we present a female patient whose cauda equina syndrome developed as a result of accidental extradural pneumorrhachis after epidural injection in the lumbar spine.

Radiologic Manifestations of Mycobacterium chimaera Infection After Open Heart Surgery.

PURPOSE: The objective of this study is to identify and detail the radiologic manifestations of surgical site and disseminated Mycobacterium chimaera (MC) infection. The aim is to facilitate early identification and diagnosis of MC, considering its indolent nature and the challenges involved in clinically and pathologically establishing the diagnosis. PATIENTS AND METHODS: This was a retrospective cohort study reviewing computed tomography (CT), positron emission tomography (PET)/CT, and magnetic resonance imaging examinations in patients over the age of 18 years with a history of open heart surgery and a clinical or pathologic diagnosis of MC. Two radiology residents, a fellowship-trained nuclear medicine radiologist, and a fellowship-trained cardiothoracic radiologist performed consensus reads to determine the imaging findings seen in MC infection. RESULTS: Twenty-five patients were included. Localized, surgical site infection was more common than disseminated disease. Typical CT findings included peristernal soft tissue thickening, sinus tracts often extending to the cutaneous surface, slowly enlarging fluid collections, and sternal osteolysis. PET/CT findings demonstrated hypermetabolic activity in nearly all patients localized to sites of infection. Imaging findings for disseminated infection included hepatosplenomegaly, lymphadenopathy, involvement of the central nervous system, discitis/osteomyelitis, and distant abscesses. CONCLUSIONS: Imaging plays a vital role in suggesting possible surgical sites and disseminated MC infection acquired from open heart surgery. Radiologists must keep a high index of suspicion given the indolent nature and subtle imaging change over time. PET/CT is most useful in diagnosis and helps in differentiating between a sterile postoperative fluid collection or scarring and active MC infection and helps provide a target for debridement.

A Fluorescent Chemosensor for Detection pH and Cu2+ Ion Base on 7-((2-Aminoethyl)amino)-5-Bromo-6-Hydroxy-1-Methylquinolin-1-ium-3-Sulfonate: Experimental and DFT Calculation.

A quinoline derivative 7-((2-aminoethyl)amino)-5-bromo-6-hydroxy-1-methylquinolin-1-ium-3-sulfonate (QEt) containing quinoline ring, -[Formula: see text] sulfonate, -OH phenol, and amine groups was synthesized and studied luminescence properties. The aqueous solutions QEt 10µM change luminescence color from green (λem = 490 nm) to yellow (λem = 563 nm) as increasing pH and the intensity at a peak of 563 nm is linearly proportional with pH value in the range of pH = 3,0-4,0. The QEt solution can be used as a chemosensor for Cu2+ with an LOD value at 0.66 [Formula: see text]. Along with the experiment, the structure, absorption and emission spectra of QEt have been investigated by TD-DFT calculation. The result shows that the absorption band centered at 420 nm is due to the electron transition from HOMO to LUMO (π → π*). The results also help to assign emission band centered at 490 nm is due to the S1 → S0 transition (LUMO → HOMO singlet transition), at 563 nm is due to the T1 → S0 transition (LUMO → HOMO triplet transition). The dependence of the relative intensity of each emission peak on pH, which is experimentally recorded, is explained based on the results of theoretical TD-DFT calculation.

Endovascular treatment for life-threatening hemoptysis due to rupture of descending thoracic aortic aneurysm: A case series.

INTRODUCTION AND IMPORTANCE: Aortic aneurysm is an uncommon but life-threatening cause of hemoptysis. Treatments include surgery and/or endovascular intervention, each with its own advantages and disadvantages. Endovascular intervention is associated with good early and medium-term outcomes. CASE PRESENTATIONS: We report three cases of hemoptysis due to ruptured thoracic aortic aneurysm who underwent endovascular intervention. In all three cases, endovascular grafts were placed in the descending thoracic aorta, the number of grafts used was 1, the average time to stop hemoptysis was 4 to 5 days, and the length of hospital stay was between 6 and 8 days. No intravascular fistula, renal failure, prolonged mechanical ventilation and other major cardiovascular events were reported. CLINICAL DISCUSSION: Endovascular treatment for descending TAA has been demonstrated to be safe and effective, particularly in emergencies in which patients presented with life-threatening hemoptysis, due to its rapid access to the aorta. In our experience at a tertiary hospital in southern Vietnam, the procedural time for a thoracic endovascular aortic repair is relatively brief and can last between 15 and 30 min. Thus, endovascular treatment for ruptured TAA can substantially improve patient prognosis, reduce mortality and complications. CONCLUSION: The implementation of endovascular intervention can help improve prognosis, reduce mortality and complications in patients with hemoptysis due to ruptured thoracic aortic aneurysm.

Transforming stress program on medical students' stress mindset and coping strategies: a quasi-experimental study.

OBJECTIVE: Stress is a significant concern in medical education, and identifying effective ways to deal with stress may help with students' mental health and professional development. This study aimed to examine the effects of the Transforming Stress Program (TSP) amongst first-year medical students on their stress mindset and coping strategies when confronted with stressors. METHODS: We conducted a quasi-experimental study at the University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam. A total of 409 first-year students at the Faculty of Medicine were divided into intervention group (205 students) and control group (204 students). The 10-week TSP was delivered as an extra-curricular course. The training adopts psychoeducation based on Dialectical Behavioral Therapy with mindfulness as a fundamental practice incorporated into each component of the program. The intervention group received the training in the first semester; the control group received identical program in the second semester. Stress Mindset Measurement and Brief Coping Orientation to Problems Experienced were measured before the intervention (T0), immediately after intervention on Intervention group (T1), and six months after intervention on Intervention group (T2). RESULTS: At T1, the intervention group showed 65% improvements in stress mindset scores and increases in coping strategies scores in six domains (Problem solving, Social support, Humor, Religion, Venting, and Self-distraction) and decreases in three (Avoidance, Substance use, and Self-blame). The effect sizes were significant in all outcomes (Cohen's d > 0.2). Measurements of the control group did not change significantly in the same period. At T2, effects of the TSP were found decreased in some domains (Avoidance, Substance use, and Self-blame) compared to T1, but largely remained significantly better than T0. CONCLUSIONS: The TSP is a feasible and effective approach that significantly enhanced medical students' stress mindset and coping strategies. Some effects were still observable 6 months after the intervention. The relatively intensive intervention requires support of the school administration and staff.

Impact of physical and social living environments on pro-environmental intentions.

The living environment might play an important role in shaping the pro-environmental intentions of the people. However, there was limited research on how the living environments influenced the pro-environmental intentions of people. The objectives of this study are to evaluate the direct effects of physical and social environments on pro-environmental intentions as well as the mediating effects of environmental attitudes and life satisfaction. Structural Equation Modeling was used with data extracted from the 2020 Taiwan Social Change Survey database (n = 1671). Results showed direct positive associations of both physical and social environments with pro-environmental intentions (ß = 0.133 and ß = 0.076, respectively) as well as indirect positive associations via the life satisfaction-mediating pathway (ß = 0.031 and ß = 0.044, respectively). The physical environment negatively influenced pro-environmental intentions through the environmental attitude pathway (ß = - 0.255) with unpleasant neighborhood enhancing the pro-environmental intentions of residents. Taken together, the overall effect of the physical environment was negative (ß = - 0.093) while that of the social environment was positive (ß = 0.109). The most important factors for the physical and social environments were disturbance and livability in north, central and south Taiwan, neighborhood pollution and interestingness in east Taiwan. Accordingly, minimizing disturbance and neighborhood pollution of the physical environment could have the highest effect on pro-environmental intentions enhancement in western and eastern Taiwan, respectively. For the social environment, improving livability in the west and interestingness in the east would have an even larger impact on pro-environmental intentions. This study emphasized the importance of neighborhood environment on the environmental intentions of the people. The study also identified the important factors for policymakers to target to achieve the best effect on improving environmental intentions.

Characterization of Shigella flexneri in northern Vietnam in 2012-2016.

Introduction: Shigellosis remains a considerable public health concern in developing countries. Shigella flexneri and Shigella sonnei are prevalent worldwide and S. sonnei has been replacing S. flexneri . Gap Statement: S. flexneri still causes outbreaks of shigellosis in northern Vietnam but limited information is available on its genetic characteristics. Aim: This study aimed to characterize the genetic characteristics of S. flexneri strains from northern Vietnam. Methodology: This study used 17 isolates from eight incidents, collected in northern Vietnam between 2012 and 2016. The samples were subjected to whole genome sequencing, molecular serotyping, cluster analysis and identification of antimicrobial resistance genes. Additionally, phylogenetic analysis was performed including isolates from previous studies. Results: Clusters were identified according to spatiotemporal backgrounds. The results suggested that two incidents in Yen Bai province in 2015 and 2016 were derived from a very recent common ancestor. All isolates belonged to phylogroup (PG) 3, which was divided into two sub-lineages. Thirteen of 17 isolates, including those from the Yen Bai incidents, belonged to sub-lineage Sub-1 and were serotyped as 1a. The remaining four isolates belonged to sub-lineage Sub-2 and were the globally predominant serotype 2a. The Sub-1 S. flexneri isolates possessed the gtrI gene, which encodes the glycosyl transferase that determines serotype 1a, with bacteriophage elements in the vicinity. Conclusion: This study revealed two PG3 sub-lineages of S. flexneri in northern Vietnam, of which Sub-1 might be specific to the region.

Anatomic characteristics and novel transplantation model of the canine uterus.

Background: In Vietnam, the rate of absolute uterine factor infertility is increasing, but no study has been published on uterine transplantation. The present study was designed to comprehensively observe the canine uterine anatomy and to examine the possibility of using a living canine donor for uterine transplantation training and further research. Methods: Ten female Vietnamese mixed-breed dogs were sacrificed for anatomical research, and 15 additional pairs were used to evaluate the novel uterine transplant model. Results: The anatomic features of the canine uterus differed considerably from those of the human uterus, with the uterine vessels originating from branches of the pudendal vessels (also known as the vaginal vessels). The uterine vascular pedicle had a small diameter (1 to 1.5 mm for arteries and 1.2 to 2.0 mm for veins) and required manipulation under a microscope. To perform uterine transplantation, the donor specimen's artery and vein lengths were successfully reconstructed by anastomosis between both sides of the vasculature using autologous Y-shaped subcutaneous veins. The living-donor uterine transplantation model constructed in this study was feasible, with the transplanted uterus surviving in 86.7% of cases (13/15). Conclusions: Uterine transplantation was successfully performed in a Vietnamese canine living donor model. This model could be helpful in uterine transplantation training and improve the transplantation success rate in humans.

Acute edematous pancreatitis caused by Fasciola hepatica infection: A rare case report.

Acute edematous pancreatitis is a medical emergency characterized by a sudden pancreas inflammation. It can be caused by various factors, primarily gallstones, alcohol consumption, or medication. Acute edematous pancreatitis caused by Fasciola hepatica infection is exceptionally rare and could be overlooked. We report a case of a 24-year-old female patient who presented with onsets of clinical and paraclinical signs of acute pancreatitis (AP). The patient was diagnosed with Fasciola hepatica-induced edematous pancreatitis, a rare parasitic infection that can cause AP. This case highlights the importance of considering parasitic infections in the differential diagnosis of edematous pancreatitis, particularly in young patients with no significant medical history.

Estimating the daily average concentration variations of PCDD/Fs in Taiwan using a novel Geo-AI based ensemble mixed spatial model.

It is generally established that PCDD/Fs is harmful to human health and therefore extensive field research is necessary. This study is the first to use a novel geospatial-artificial intelligence (Geo-AI) based ensemble mixed spatial model (EMSM) that integrates multiple machine learning algorithms and geographic predictor variables selected using SHapley Additive exPlanations (SHAP) values to predict spatial-temporal fluctuations in PCDD/Fs concentrations across the entire island of Taiwan. Daily PCDD/F I-TEQ levels from 2006 to 2016 were used for model construction, while external data was used for validating model dependability. We utilized Geo-AI, incorporating kriging, five machine learning, and ensemble methods (combinations of the aforementioned five models) to develop EMSMs. The EMSMs were used to estimate long-term spatiotemporal variations in PCDD/F I-TEQ levels, considering in-situ measurements, meteorological factors, geospatial predictors, social and seasonal influences over a 10-year period. The findings demonstrated that the EMSM was superior to all other models, with an increase in explanatory power reaching 87 %. The results of spatial-temporal resolution show that the temporal fluctuation of PCDD/F concentrations can be a result of weather circumstances, while geographical variance can be the result of urbanization and industrialization. These results provide accurate estimates that support pollution control measures and epidemiological studies.

A Numerical Modelling Framework for Investigating the Ballistic Performance of Bio-Inspired Body Armours.

Biological structures possess excellent damage tolerance, which makes them attractive for ballistic protection applications. This paper develops a finite element modelling framework to investigate the performance of several biological structures that are most relevant for ballistic protection, including nacre, conch, fish scales, and crustacean exoskeleton. Finite element simulations were conducted to determine the geometric parameters of the bio-inspired structures that can survive projectile impact. The performances of the bio-inspired panels were benchmarked against a monolithic panel with the same 4.5 mm overall thickness and projectile impact condition. It was found that the biomimetic panels that were considered possessed better multi-hit resistant capabilities compared to the selected monolithic panel. Certain configurations arrested a fragment simulating projectile with an initial impact velocity of 500 m/s, which was similar to the performance of the monolithic panel.

Genomic characterization of endemic diarrheagenic Escherichia coli and Escherichia albertii from infants with diarrhea in Vietnam.

BACKGROUND: Diarrheagenic Escherichia coli (DEC) is a group of bacterial pathogens that causes life-threatening diarrhea in children in developing countries. However, there is limited information on the characteristics of DEC isolated from patients in these countries. A detailed genomic analysis of 61 DEC-like isolates from infants with diarrhea was performed to clarify and share the characteristics of DEC prevalent in Vietnam. PRINCIPAL FINDINGS: DEC was classified into 57 strains, including 33 enteroaggregative E. coli (EAEC) (54.1%), 20 enteropathogenic E. coli (EPEC) (32.8%), two enteroinvasive E. coli (EIEC) (3.3%), one enterotoxigenic E. coli (ETEC), and one ETEC/EIEC hybrid (1.6% each), and surprisingly into four Escherichia albertii strains (6.6%). Furthermore, several epidemic DEC clones showed an uncommon combination of pathotypes and serotypes, such as EAEC Og130:Hg27, EAEC OgGp9:Hg18, EAEC OgX13:H27, EPEC OgGp7:Hg16, and E. albertii EAOg1:HgUT. Genomic analysis also revealed the presence of various genes and mutations associated with antibiotic resistance in many isolates. Strains that demonstrate potential resistance to ciprofloxacin and ceftriaxone, drugs recommended for treating childhood diarrhea, accounted for 65.6% and 41%, respectively. SIGNIFICANCE: Our finding indicate that the routine use of these antibiotics has selected resistant DECs, resulting in a situation where these drugs do not provide in therapeutic effects for some patients. Bridging this gap requires continuous investigations and information sharing regarding the type and distribution of endemic DEC and E. albertii and their antibiotic resistance in different countries.

Design, Development, and Deployment of an Electronic Immunization Registry: Experiences From Vietnam, Tanzania, and Zambia.

INTRODUCTION: There is growing interest among low- and middle-income countries to introduce electronic immunization registries (EIRs) that capture individual-level vaccine data. We compare the design, development, and deployment of EIRs in Vietnam, Tanzania, and Zambia. Through desk review and the authors' firsthand implementation experiences, we describe experiences related to timeline, partnerships, financial costs, and technology and infrastructure. IMPLEMENTATION EXPERIENCE: The country cases highlight the multi-year timeline required to implement an EIR at scale and the benefit of multiple iterative cycles to pilot and redesign the system before achieving scale. Of the 3 countries, only Vietnam has achieved nationwide scale of the EIR, which took 7 years. In all 3 countries, national government leadership as part of an interdisciplinary team (with experience in leadership, technology, and immunization) was important to ensure country ownership and sustainability. Where international software developers were contracted, partnering with a local software company helped improve responsiveness and sustainability. Across all 3 countries, governments contributed significant in-kind time in addition to investments from donors. Cost savings were observed in Tanzania and Zambia, largely driven by health worker time savings from using the EIR. All 3 case countries underscore the need to understand the local technology and infrastructure context and design the EIR to fit the context. In Vietnam, an initial landscape assessment was conducted to assess technology and infrastructure, whereas in Tanzania and Zambia, user advisory groups provided insights. Existing infrastructure informed EIR design decisions, such as choosing a system with offline functionality in Tanzania and Zambia. All 3 countries have a local partner to provide ongoing technical support. CONCLUSION: Comparing implementation factors across these cases highlights practical experience and recommendations that complement existing EIR guidance documents. The findings and recommendations from this study can inform other countries considering or in the process of implementing an EIR.

ATP7B-Deficient Hepatocytes Reveal the Importance of Protein Misfolding Induced at Low Copper Concentration.

Copper is a transition metal essential for human life. Its homeostasis is regulated in the liver, which delivers copper to the whole body and excretes its excess outside the organism in the feces through the bile. These functions are regulated within hepatocytes, and the ATP7B copper transporter is central to making the switch between copper use and excretion. In Wilson disease, the gene coding for ATP7B is mutated, leading to copper overload, firstly, in the liver and the brain. To better understand the role of ATP7B in hepatocytes and to provide a smart tool for the development of novel therapies against Wilson disease, we used the CrispR/Cas9 tool to generate hepatocyte cell lines with the abolished expression of ATP7B. These cell lines revealed that ATP7B plays a major role at low copper concentrations starting in the micromolar range. Moreover, metal stress markers are induced at lower copper concentrations compared to parental cells, while redox stress remains not activated. As shown recently, the main drawback induced by copper exposure is protein unfolding that is drastically exacerbated in ATP7B-deficient cells. Our data enabled us to propose that the zinc finger domain of DNAJ-A1 would serve as a sensor of Cu stress. Therefore, these Wilson-like hepatocytes are of high interest to explore in more detail the role of ATP7B.

Density Functional Study of Size-Dependent Hydrogen Adsorption on Ag n Cr (n = 1-12) Clusters.

Increasing interest has been paid for hydrogen adsorption on atomically controlled nanoalloys due to their potential applications in catalytic processes and energy storage. In this work, we investigate the interaction of H2 with small-sized Ag n Cr (n = 1-12) using density functional theory calculations. It is found that the cluster structures are preserved during the adsorption of H2 either molecularly or dissociatively. Ag3Cr-H2, Ag6Cr-H2, and Ag9Cr-H2 clusters are identified to be relatively more stable from computed binding energies and second-order energy difference. The dissociation of adsorbed H2 on Ag2Cr, Ag3Cr, Ag6Cr, and Ag7Cr clusters is favored both thermodynamically and kinetically. The dissociative adsorption is unlikely to occur because of a considerable energy barrier before reaching the final state for Ag4Cr or due to energetic preferences for n = 1, 5, and 8-12 species. Comprehensive analysis shows that the geometric structure of clusters, the relative electronegativity, and the coordination number of the Cr impurity play a decisive role in determining the preferred adsorption configuration.

Novel synthetic clot analogs for in-vitro stroke modelling.

PURPOSE: The increased demand for training of mechanical thrombectomy in ischemic stroke and development of new recanalization devices urges the creation of new simulation models both for training and device assessment. Clots properties have shown to play a role in procedural planning and thrombectomy device effectiveness. In this study, we analyzed the characteristics and applicability of completely synthetic, animal-free clots in the setting of an in-vitro model of mechanical thrombectomy for training and device assessment. METHODS: Synthetic clots based on agarose (n = 12) and silicone (n = 11) were evaluated in an in-vitro neurointervention simulation of mechanical thrombectomy with clot extraction devices. Calcified clots of mixed nature were simulated with addition of 3D printed structures. 9 clots were excluded due to insufficient vessel occlusion and failure to integrate with clot extraction device. Synthetic thrombi were characterized and compared using a categorical score-system on vessel occlusion, elasticity, fragmentation, adherence and device integration. RESULTS: Both agarose-based and silicone-based clots demonstrated relevant flow arrest and a good integration with the clot extraction device. Silicone-based clots scored higher on adherence to the vessel wall and elasticity. CONCLUSION: Selected synthetic clots can successfully be implemented in an in-vitro training environment of mechanical thrombectomy. The clots' different properties might serve to mimic fibrin-rich and red blood cell-rich human thrombi.

Characteristics and health impacts of PM2.5-bound PCDD/Fs in three Asian countries.

Polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) were ubiquitous, persistent chemical compounds attached to particulate matter in the atmosphere. We aimed to study the characteristics of these pollutants in atmospheric PM2.5 of three Asian countries, including Taiwan (Taipei), Thailand (Chiang Mai), and Vietnam (Hanoi). We carried out a source apportionment analysis to determine significant PCDD/F contributors in these areas. Multiple media model was conducted to access the health impact assessment. The PM2.5 concentration in Taipei (n = 7), Chiang Mai (n = 20), and Hanoi (n = 10) were 18.4 ± 6.21 µg/m3, 133 ± 49.5 µg/m3, and 88.1 ± 12.6 µg/m3, respectively. The PCDD/Fs level in Hanoi was 92.4 ± 67.3 fg I-TEQ/m3, and in Taipei and Chiang Mai was 5.01 ± 2.39 fg I-TEQ/m3 and 14.4 ± 13.1 fg I-TEQ/m3, respectively, which showed that the higher PM2.5 concentration was not necessary to follow with higher PCDD/Fs level. In all three cities, the effect of traffic on ambient PCDD/F level was significant (23-25 %). However, we also observed the specific sources of PCDD/Fs in each city during the sampling periods, namely long-range transport (Taipei, 55 %), Biomass/open burning (Chiang Mai, 77 %), and industrial activities (Hanoi, 34 %). In the carcinogenic risk estimation, the highest median total carcinogenic risk was in Hanoi (5.87 × 10-6), followed by Chiang Mai (1.06x10-6), and Taipei (2.95 × 10-7). Although diet was the major absorption pathway, the food contributor of exposure differed among the three areas due to the difference in food consumption composition.