In this paper, the magneto-optical transport (MOT) properties of III-nitride Pöschl-Teller quantum well (QW) semiconductors, including AlN, GaN, and InN, resulting from the acoustic phonon interaction are thoroughly investigated and compared by applying the technique of operator projection. In particular, a comparison is made between the Pöschl-Teller QW results and the square QW ones. The findings demonstrate that the MOT properties of III-nitride QW semiconductors resulting from acoustic phonon scattering are strongly influenced by the quantum system (QS) temperature, applied magnetic field, and QW width.
View Article and Find Full Text PDFIntroduction: This study provides an analysis of head and neck cancer (HNC) cases over a 20-year period in Ho Chi Minh City, Vietnam. It aims to shed light on HNC's characteristics and trends in this highly populated urban region.
Methods: The analysis encompasses 8974 HNC cases, emphasising incidence rates, gender distribution, and the prevalence of different subtypes, including oral cavity, nasopharyngeal, oropharyngeal, and laryngeal/pharyngeal cancers.
Rotavirus (RV), norovirus (NoV), sapovirus (SaV), and human astrovirus (HAstV) are the most common viral causes of gastroenteritis in children worldwide. From 2016 to 2021, we conducted a cross-sectional descriptive study to determine the prevalence of these viruses in hospitalized children under five years old in Nam Dinh and Thua Thien Hue provinces in Vietnam during the pilot introduction of the RV vaccine, Rotavin-M1 (POLYVAC, Hanoi, Vietnam). We randomly selected 2317/6718 (34%) acute diarrheal samples from children <5 years of age enrolled at seven sentinel hospitals from December 2016 to May 2021; this period included one year surveillance pre-vaccination from December 2016 to November 2017.
View Article and Find Full Text PDFBackground: Half of diarrhea hospitalizations in children aged <5 years in Vietnam are due to rotavirus. Following introduction of a locally developed and licensed oral rotavirus vaccine, Rotavin-M1, into the routine immunization program in two Vietnamese provinces, Nam Dinh and TT Hue, we describe changes in rotavirus positivity among children hospitalized for diarrhea and calculate vaccine effectiveness against moderate-to-severe rotavirus hospitalizations.
Methods: Active rotavirus surveillance among children <5 years began in December 2016 at sentinel hospitals in districts where rotavirus vaccine was introduced in December 2017.
Two-dimensional (2D) structures can stably exist in different allotropes. In this manuscript, we propose a new series of Janus structures based on the β-phase of germanium monochalcogenides, namely, β-GeXY (X/Y = S, Se, and Te) monolayers. Our calculations indicate that Janus β-GeXY monolayers have a stable crystal structure and possess anisotropic mechanical properties.
View Article and Find Full Text PDFBackground: Chicken infectious anemia (CIA) caused by the CIA virus (CIAV) is considered one of the most important immunosuppressive diseases affecting chickens and recently poses a great economic burden to the poultry industry worldwide.
Aim: This study aims to identify the presence of CIAV in the Mekong Delta (MD), Vietnam, and to determine genotypes of CIAVs that are currently circulating in this area.
Methods: Organ samples (spleen, liver, and thymus) of 144 chickens suspected with CIA from 47 poultry farms were collected.
The objectives of this study were to describe the epidemiology of African swine fever (ASF) and to identify factors that increased commune-level risk for ASF in Can Tho, a province in the Mekong River Delta of Vietnam. In 2019, a total of 2377 of the 5220 pig farms in Can Tho were ASF positive, an incidence risk of 46 (95% CI 44-47) ASF positive farms for every 100 farms at risk. Throughout the outbreak ASF resulted in either the death or culling of 59,529 pigs out of a total population size of 124,516 (just under half of the total pig population, 48%).
View Article and Find Full Text PDFDue to the breaking of the mirror symmetry, two-dimensional layered Janus materials possess many extraordinary mechanical and electronic properties that cannot exist in symmetric structures. In this paper, we propose and investigate the structural and electronic properties of Janus T'-RuXY (X/Y = S, Se, and Te) monolayers using the first-principles simulations. Our calculated results indicate that the T'-RuXY is found to be dynamically and mechanically stable through the phonon dispersion analysis and examination of elastic properties.
View Article and Find Full Text PDFThe objective of this study is to report the complete-genome sequence of a field African swine fever (ASF) virus (ASFV), namely ASF/VN/CanTho-OM/2021, which caused a fatal outbreak in domestic pigs in the Mekong Delta. Complete-genome sequencing detected an 18 bp nucleotide deletion in the EP402R gene (encoding for serotype-specific proteins CD2v) of ASF/VN/CanTho-OM/2021, which was determined to belong to genotype 2 and serotype 8. This mutation pattern was confirmed as unique in GenBank; thus, ASF/VN/CanTho-OM/2021 can be considered a novel variant, with a potential change of sero-characteristics within genotype 2.
View Article and Find Full Text PDFMarek's disease (MD) is a common lymphomatous and neuropathic disease of birds, especially chickens, and has caused significant losses to chicken production as a result of high mortality and morbidity. This study aims to determine the status of MD in backyard flocks in the Mekong Delta of Vietnam and to analyze clinical cases occurring during a year. The study was carried out from August 2018 to July 2019, during which time 16 suspected cases of chicken flocks with MD were observed, 40 chickens were subjected to anatomopathological examination, and PCR was performed for diagnosis of MD and determination of Marek's disease virus (MDV) serotypes.
View Article and Find Full Text PDFWe theoretically address the electronic structure of mono- and simple bi-layer armchair graphene nanoribbons (AGNRs) when they are infected by extrinsic charged dilute impurity. This is done with the aid of the modified tight-binding method considering the edge effects and the Green's function approach. Also, the interplay of host and guest electrons are studied within the full self-consistent Born approximation.
View Article and Find Full Text PDFMeasles-associated deaths have been reported in infants <9 months during outbreaks. A cohort study was conducted on 210 infants aged 6-8 months to evaluate the immunogenicity and safety of the AIK-C measles vaccine containing 10 plaque-forming units (PFU)/0.5 mL produced in Vietnam.
View Article and Find Full Text PDFThe development of live-attenuated vaccines against Dengue virus (DENV) has been problematic. Dengvaxia, licensed in several countries where DENV is endemic, has shown low efficacy profiles and there are safety concerns prohibiting its administration to children younger than 9 years old, and the live-attenuated tetravalent vaccine (LATV) developed by NIAID has proven too reactogenic during clinical trialing. In this work we examined whether the combination of TV005, a LATV-derived formulation, with Tetra DIIIC, a subunit vaccine candidate based on fusion proteins derived from structural proteins from all four DENV serotypes, can overcome the respective limitations of these two vaccine approaches.
View Article and Find Full Text PDFOne of the major problems faced for the development of a vaccine against Dengue virus is the lack of a suitable animal model. Although non-human primates do not show overt signs of disease, these animals develop viremia after the infection and are the best model to evaluate vaccine candidates against this pathogen. However, for that purpose, the screening of all animals is mandatory to discard those with previous natural immunity.
View Article and Find Full Text PDFBackground/aims: To compare treatment outcomes with and without silicone oil tamponade in patients undergoing pars plana vitrectomy (PPV) for severe endogenous bacterial endophthalmitis (BEE).
Methods: One hundred and eight consecutive patients with severe BEE (defined by the absence of pupil red reflex at presentation and/or dense vitreous opacity on ultrasound and no improvement after 24-36 hours of medical treatment) were randomly assigned to two treatment groups: Group 1, standard PPV with intravitreal antibiotics; and Group 2, PPV with intravitreal antibiotics and silicone tamponade. Overall success was defined as: a visual acuity ≥ count fingers at 1 meter, with an attached retina, and no intraocular oil.
We tested a candidate live, oral, rotavirus vaccine (Rotavin-M1™) derived from an attenuated G1P [8] strain (KH0118-2003) isolated from a child in Vietnam. The vaccine was tested first for safety in 29 healthy adults. When deemed safe, it was further tested for safety and immunogenicity in 160 infants (4 groups) aged 6-12 weeks in a dose and schedule ranging study.
View Article and Find Full Text PDFWe examined clinical and nutritional predictors of weight change over two consecutive 6-month intervals among 99 HIV-positive male injection drug users initiating antiretroviral therapy (ART) in Hanoi, Vietnam. The average weight gain was 3.1 ± 4.
View Article and Find Full Text PDFBackground: The relationships between the infecting dengue serotype, primary and secondary infection, viremia and dengue severity remain unclear. This cross-sectional study examined these interactions in adult patients hospitalized with dengue in Ha Noi.
Methods And Findings: 158 patients were enrolled between September 16 and November 11, 2008.
Certain mutations in the connection subdomain and RNase H domain of reverse transcriptase (RT) of subtype B HIV-1 contribute to resistance to nucleoside reverse transcriptase inhibitors (NRTIs). However, the impact of non-B subtype polymorphisms in this region on drug resistance remains unclear. In this study, we determined the frequencies of drug resistance mutations of the entire RT in patients with treatment failure from a cohort of Circulating recombinant form (CRF) 01_AE HIV-1-infected patients in Hanoi, Viet Nam.
View Article and Find Full Text PDFTrichinellosis outbreaks occur occasionally in Vietnam following the consumption of undercooked pork. Diagnosing trichinella can be problematic because fever and myalgia are nonspecific, and diagnosis may be delayed. We describe 5 Vietnamese patients in whom trichinellosis was diagnosed after several weeks of illness.
View Article and Find Full Text PDFBackground: The first cases of avian influenza A (H5N1) in humans in Vietnam were detected in early 2004, and Vietnam has reported the second highest number of cases globally.
Methods: We obtained retrospective clinical data through review of medical records for laboratory confirmed cases of influenza A (H5N1) infection diagnosed in Vietnam from January 2004 through December 2006. Standard data was abstracted regarding clinical and laboratory features, treatment, and outcome.
We performed a retrospective case-series study of patients with influenza A (H5N1) admitted to the National Institute of Infectious and Tropical Diseases in Hanoi, Vietnam, from January 2004 through July 2005 with symptoms of acute respiratory tract infection, a history of high-risk exposure or chest radiographic findings such as pneumonia, and positive findings for A/H5 viral RNA by reverse transcription-PCR. We investigated data from 29 patients (mean age 35.1 years) of whom 7 (24.
View Article and Find Full Text PDFIn the absence of a parenteral drug, oral oseltamivir is currently recommended by the WHO for treating H5N1 influenza. Whether oseltamivir absorption is adequate in severe influenza is unknown. We measured the steady state, plasma concentrations of nasogastrically administered oseltamivir 150 mg bid and its active metabolite, oseltamivir carboxylate (OC), in three, mechanically ventilated patients with severe H5N1 (male, 30 yrs; pregnant female, 22 yrs) and severe H3N2 (female, 76 yrs).
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