Background: Currently, tracking, monitoring insecticide resistance of mosquitoes transmitting disease is an urgent need.\r\n', u'Objectives: To evaluate resistance to insecticide of three mosquito species: Aedes Aegypti, Culex quinquefasciatus and culex tritaenyorhynchus in Ha Noi\r\n', u'Subject and method: Aedes Aegypti, Culex quinquefasciatus culex tritaenyorhynchus mosquito species was collected from some districts of Ha Noi city. These mosquito species was tested sensitivity with 4 insecticides: permethrin 0.75%, lambda-cyhalothrin 0.05%, alpha-cypermethrin 30mg/m2 and DDT 4.0%.\r\n', u'Results: Three main vectors of Dengue fever, Japanese Encephalic and Filariasis mosquitoes were found in a very high density in some areas of Ha Noi City. Aedes aegypti mosquitoes in the districts of Thanh Xuan (TX), Dong Da (DD) and Hoang Mai (HM) was found highly resistant to permethrin, alpha - cypermethrin, lambda - cyhalothrin and DDT with the mortalities rates of 51 % (TX) and 59%(DD); 70%(HM); 90%, 82% and 96%; 74%, 54% and 59%; 1 %, 8% and 32%, respectively. \r\n', u'Culex tritaenyorhynchus was found also highly resistant to permethrin with the mortality rate of 29%, alphacypermethrin - 18%, lambdacyhalothrin - only 3% and DDT x36%. Culex quinquefasciatus was found also highly resistant to those insecticides. \r\n', u'Conclusion: Other insecticides should choose to replace the chemicals used in this experiment to control, kill mosquitoes when epidemics occur.\r\n', u'
Insecticides ; resistance ; Aedes Aegypti ; Culex quinquefasciatus ; culex tritaenyorhynchus

OBJECTIVES: General health examinations (GHE) have become an increasingly common measure for preventive medicine in Vietnam. However, little is known about the factors among Viet-namese people who attend or miss GHE. Budget or time constraints remain to be evaluated for better-informed policy making. This study investigates factors affecting behaviors in attending periodic GHE. The main objectives are as follows: (1) to explore empirical relationships between influencing factors and periodic GHE frequencies, and (2) to predict the probabilities of attending GHE under associated conditions. METHODS: The study used a 2,068-observational dataset, obtained from a Vietnamese survey in 2016. The analysis was then performed using the methods of baseline-category logits for establishing relationships between predictor and response variables. RESULTS: Significant relationships were found among the expenditure and time consumption, health priority and sensitivity to health data, insurance status, and frequency of GHE, with most p-values = 0.01. CONCLUSION: Generally, people attended the GHE when they had the resources and health priorities (72.7% probability). Expenditure and time remain key obstacles to the periodic GHE. Health priority and health data are important in improving rates for GHEs. Health insurance should play a positive role in promoting the GHE.
Asian Continental Ancestry Group* ; Budgets ; Cross-Sectional Studies* ; Dataset ; Health Expenditures ; Health Priorities ; Humans ; Insurance Coverage ; Insurance, Health ; Policy Making ; Preventive Medicine ; Vietnam

OBJECTIVE: This study was aimed at comparing the mandibular arch forms of Korean and Vietnamese patients by using facial axis (FA) points on three-dimensional (3D) models. METHODS: Mandibular casts of 68 Korean (Class I malocclusion, 30; Class II malocclusion, 38) and 78 Vietnamese (Class I malocclusion, 41; Class II malocclusion, 37) patients were scanned in their occluded positions and grouped according to arch form (tapered, ovoid, and square). The FA point of each tooth was digitized on the 3D mandibular models. The measurements and frequency distributions of the arch forms were compared between the ethnic groups. RESULTS: The Vietnamese patients had significantly greater intercanine depth and intercanine and intermolar width-to-depth ratios than the Korean patients (p < 0.05). The frequency distributions of the arch forms were also significantly different (p = 0.038), but no sexual dimorphism was found. CONCLUSIONS: Vietnamese people tend to have deeper and wider arches than Korean people. The three arch forms are evenly distributed in Korean people, but Vietnamese people frequently have square arches. Clinicians should identify the correct arch form of an ethnic group before initiating orthodontic treatment.
Asian Continental Ancestry Group* ; Axis, Cervical Vertebra* ; Ethnic Groups ; Humans ; Malocclusion ; Tooth

OBJECTIVE: The purposes of this study were to measure the palatal soft tissue thickness at popular placement sites of temporary anchorage devices (TADs) by cone-beam computed tomography (CBCT) and evaluate the age, gender, and positional differences in this parameter. METHODS: The study sample consisted of 23 children (10 boys and 13 girls; mean age, 10.87 +/- 1.24 years; range, 6.7 to 12.6 years) and 27 adults (14 men and 13 women; mean age, 21.35 +/- 1.14 years; range, 20.0 to 23.8 years). Nine mediolateral and nine anteroposterior intersecting reference lines were drawn on CBCT scans of the 50 subjects, and the resultant measurement areas were designated according to their mediolateral (i.e., lateral, medial, and sutural) and anteroposterior (i.e., anterior, middle, and posterior) positions. Repeated-measures analysis of variance was performed to analyze intragroup and intergroup differences. RESULTS: No significant age and gender differences were found (p = 0.309 and 0.124, respectively). Further, no significant anteroposterior change was observed (p = 0.350). However, the lateral area presented the thickest soft tissue whereas the sutural area had the thinnest soft tissue (p < 0.001). CONCLUSIONS: Clinical selection of the placement sites of TADs should be guided by knowledge of the positional variations in the palatal soft tissue thickness in addition to other contributing factors of TAD stability.
Adult ; Child ; Cone-Beam Computed Tomography ; Humans ; Male

This study was conducted to determine the prevalence and characteristics of pathogenic Escherichia (E.) coli strains from diarrheic calves in Vietnam. A total of 345 E. coli isolates obtained from 322 diarrheic calves were subjected to PCR and multiplex PCR for detection of the f5, f41, f17, eae, sta, lt, stx1, and stx2 genes. Of the 345 isolates, 108 (31.3%) carried at least one fimbrial gene. Of these 108 isolates, 50 carried genes for Shiga toxin and one possessed genes for both enterotoxin and Shiga toxin. The eae gene was found in 34 isolates (9.8%), 23 of which also carried stx genes. The Shiga toxin genes were detected in 177 isolates (51.3%) and the number of strains that carried stx1, stx2 and stx1/stx2 were 46, 73 and 58, respectively. Among 177 Shiga toxin-producing E. coli isolates, 89 carried the ehxA gene and 87 possessed the saa gene. Further characterization of the stx subtypes showed that among 104 stx1-positive isolates, 58 were the stx1c variant and 46 were the stx1 variant. Of the 131 stx2-positive strains, 48 were stx2, 48 were stx2c, 11 were stx2d, 17 were stx2g, and seven were stx2c/stx2g subtypes. The serogroups most prevalent among the 345 isolates were O15, O20, O103 and O157.
Animals ; Cattle ; Cattle Diseases/epidemiology/*microbiology ; DNA, Bacterial/chemistry/genetics ; Diarrhea/epidemiology/microbiology/*veterinary ; Escherichia coli/genetics/*isolation & purification/pathogenicity ; Escherichia coli Infections/epidemiology/microbiology/*veterinary ; Feces/microbiology ; Fimbriae, Bacterial/genetics ; Polymerase Chain Reaction/veterinary ; Polymorphism, Restriction Fragment Length ; Vietnam/epidemiology ; Virulence Factors/*genetics

Background: Vietnam is among the few countries that were successful in the fight against the first wave of coronavirus disease 2019 (COVID-19). However, subsequent domestic outbreaks of COVID-19 continue to occur. To sharp the community education program to guarantee the final success in the fight against COVID-19 in Vietnam and comparable countries, we examined the levels of COVID-19 knowledge and associated predictors among university students in Vietnam. Materials and Methods: A cross-sectional study was conducted on all students enrolling at Phenikaa University using a self-developed questionnaire consisted of 20 questions regarding COVID-19's risk factors, transmission routes, symptoms, and prevention. Results: Among 728 participants, 40.9% were male, 63.2% studied health-related majors, and 18.1% lived alone. Correct response rates ranged from 25.3% to 98.9% across 20 questions. Only 51.9% (378/728) of participants had good knowledge levels. Studying health majors (adjusted odds ratio [AOR] 0.547, 95% confidence interval [CI] 0.398 - 0.751, P <0.001), and living with the seniors (AOR 0.612, 95% CI 0.389 - 0.963, P= 0.034) or with friends (AOR 0.405, 95% CI 0.252 – 0.650, P <0.001) were negatively associated with a poor level of COVID-19 knowledge. Conclusion The proportion of university students having good knowledge levels is suboptimal. It is essential to improve the quality of COVID-19 education with a more focus on not only the preventive measures, but also the disease itself. More studies are needed to improve the level of COVID-19 knowledge among those living alone or do not study healthrelated majors.

Background: Vietnam is among the few countries that were successful in the fight against the first wave of coronavirus disease 2019 (COVID-19). However, subsequent domestic outbreaks of COVID-19 continue to occur. To sharp the community education program to guarantee the final success in the fight against COVID-19 in Vietnam and comparable countries, we examined the levels of COVID-19 knowledge and associated predictors among university students in Vietnam. Materials and Methods: A cross-sectional study was conducted on all students enrolling at Phenikaa University using a self-developed questionnaire consisted of 20 questions regarding COVID-19's risk factors, transmission routes, symptoms, and prevention. Results: Among 728 participants, 40.9% were male, 63.2% studied health-related majors, and 18.1% lived alone. Correct response rates ranged from 25.3% to 98.9% across 20 questions. Only 51.9% (378/728) of participants had good knowledge levels. Studying health majors (adjusted odds ratio [AOR] 0.547, 95% confidence interval [CI] 0.398 - 0.751, P <0.001), and living with the seniors (AOR 0.612, 95% CI 0.389 - 0.963, P= 0.034) or with friends (AOR 0.405, 95% CI 0.252 – 0.650, P <0.001) were negatively associated with a poor level of COVID-19 knowledge. Conclusion The proportion of university students having good knowledge levels is suboptimal. It is essential to improve the quality of COVID-19 education with a more focus on not only the preventive measures, but also the disease itself. More studies are needed to improve the level of COVID-19 knowledge among those living alone or do not study healthrelated majors.

In the present study, rutile phase titanium dioxide nanoparticles (R-TiO₂ NPs) were prepared by hydrolysis of titanium tetrachloride in an aqueous solution followed by calcination at 900℃. The composition of R-TiO₂ NPs was determined by the analysis of X-ray diffraction data, and the characteristic features of R-TiO₂ NPs such as the surface functional group, particle size, shape, surface topography, and morphological behavior were analyzed by Fourier-transform infrared spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy, transmission electron microscopy, dynamic light scattering, and zeta potential measurements. The average size of the prepared R-TiO₂ NPs was 76 nm, the surface area was 19 m²/g, zeta potential was −20.8 mV, and average hydrodynamic diameter in dimethyl sulfoxide (DMSO)–H₂O solution was 550 nm. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and morphological observations revealed that R-TiO₂ NPs were cytocompatible with oral cancer cells, with no inhibition of cell growth and proliferation. This suggests the efficacy of R-TiO₂ NPs for the aesthetic white pigmentation of teeth.
Dimethyl Sulfoxide ; Dynamic Light Scattering ; Hydrodynamics ; Hydrolysis ; Microscopy, Electron, Scanning ; Microscopy, Electron, Transmission ; Mouth Neoplasms ; Nanoparticles ; Particle Size ; Pigmentation ; Spectrometry, X-Ray Emission ; Spectrum Analysis ; Titanium ; Tooth ; X-Ray Diffraction

Background: In recent years, there has been an increase in reports of perioral vascular complications resulting from filler injections, such as necrosis of the lip or alar rim, occlusion, and in severe cases, blindness. Conversely, the use of perioral arterial flaps is becoming more prevalent in the treatment of cleft lips, cancer, and trauma. A thorough understanding of perioral arteries is essential to minimize complications and maximize the success of these flaps. However, the course of the facial artery (FA) in the perioral region remains incompletely understood. The aim of this study was to describe the variations of the FA in the perioral region. Methods: We dissected 52 embalmed and formaldehyde-fixed Vietnamese cadavers. We then studied the size and distribution of perioral arteries in 102 specimens. Results: The superior labial artery (SLA) was the most common branch, occurring in 87.25% of cadavers, followed by the inferior labial artery (ILA) at 78.43%. The SLA primarily originated above the mouth corner (cheilion), accounting for 91.01% of cases, and predominantly exhibited a tortuous course within the submucosa (78.65%). The ILA’s branching pattern varied, but it was primarily located below the cheilion (91.25%). The ILA also followed a twisted path, generally within the submucosa. The ILA exhibited two patterns: the typical pattern, distributed at the vermilion border of the lower lip (8.82%), and the horizontal labiomental artery pattern, which ran horizontally in the middle of the lower lip area (69.61%). At their origin, the SLA and ILA had average external diameters of 1.29 mm and 1.28 mm, respectively. Conclusion Numerous anatomical variations in the FA in the perioral region were found. A detailed anatomic description, suggested landmarks, and angiography before the procedure will be useful to help doctors avoid complications.