25 results on '"Nguyen Van Trang"'
Search Results
2. Spatiotemporal variation in risk of Shigella infection in childhood: a global risk mapping and prediction model using individual participant data
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Hamada S Badr, PhD, Josh M Colston, PhD, Nhat-Lan H Nguyen, BA, Yen Ting Chen, MD, Eleanor Burnett, MPH, Syed Asad Ali, MPH, Ajit Rayamajhi, MD, Syed M Satter, MPH, Nguyen Van Trang, PhD, Daniel Eibach, PD, Ralf Krumkamp, DrPH, Jürgen May, MD, Ayola Akim Adegnika, PhD, Gédéon Prince Manouana, PhD, Peter Gottfried Kremsner, MD, Roma Chilengi, MSc, Luiza Hatyoka, PhD, Amanda K Debes, PhD, Jerome Ateudjieu, PhD, Abu S G Faruque, MPH, M Jahangir Hossain, MSc, Suman Kanungo, PhD, Karen L Kotloff, MD, Inácio Mandomando, PhD, M Imran Nisar, PhD, Richard Omore, PhD, Samba O Sow, MSc, Anita K M Zaidi, SM, Nathalie Lambrecht, PhD, Bright Adu, PhD, Nicola Page, MPH, James A Platts-Mills, MD, Cesar Mavacala Freitas, MD, Tuula Pelkonen, PhD, Per Ashorn, PhD, Kenneth Maleta, PhD, Tahmeed Ahmed, PhD, Pascal Bessong, PhD, Zulfiqar A Bhutta, PhD, Carl Mason, MD, Estomih Mduma, PhD, Maribel P Olortegui, MPH, Pablo Peñataro Yori, MPH, Aldo A M Lima, PhD, Gagandeep Kang, PhD, Jean Humphrey, ScD, Robert Ntozini, MPH, Andrew J Prendergast, DPhil, Kazuhisa Okada, PhD, Warawan Wongboot, PhD, Nina Langeland, PhD, Sabrina J Moyo, PhD, James Gaensbauer, MD, Mario Melgar, MD, Matthew Freeman, PhD, Anna N Chard, MPH, Vonethalom Thongpaseuth, MD, Eric Houpt, MD, Benjamin F Zaitchik, PhD, and Margaret N Kosek, MD
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Public aspects of medicine ,RA1-1270 - Abstract
Summary: Background: Diarrhoeal disease is a leading cause of childhood illness and death globally, and Shigella is a major aetiological contributor for which a vaccine might soon be available. The primary objective of this study was to model the spatiotemporal variation in paediatric Shigella infection and map its predicted prevalence across low-income and middle-income countries (LMICs). Methods: Individual participant data for Shigella positivity in stool samples were sourced from multiple LMIC-based studies of children aged 59 months or younger. Covariates included household-level and participant-level factors ascertained by study investigators and environmental and hydrometeorological variables extracted from various data products at georeferenced child locations. Multivariate models were fitted and prevalence predictions obtained by syndrome and age stratum. Findings: 20 studies from 23 countries (including locations in Central America and South America, sub-Saharan Africa, and south and southeast Asia) contributed 66 563 sample results. Age, symptom status, and study design contributed most to model performance followed by temperature, wind speed, relative humidity, and soil moisture. Probability of Shigella infection exceeded 20% when both precipitation and soil moisture were above average and had a 43% peak in uncomplicated diarrhoea cases at 33°C temperatures, above which it decreased. Compared with unimproved sanitation, improved sanitation decreased the odds of Shigella infection by 19% (odds ratio [OR]=0·81 [95% CI 0·76–0·86]) and open defecation decreased them by 18% (OR=0·82 [0·76–0·88]). Interpretation: The distribution of Shigella is more sensitive to climatological factors, such as temperature, than previously recognised. Conditions in much of sub-Saharan Africa are particularly propitious for Shigella transmission, although hotspots also occur in South America and Central America, the Ganges–Brahmaputra Delta, and the island of New Guinea. These findings can inform prioritisation of populations for future vaccine trials and campaigns. Funding: NASA, National Institutes of Health–The National Institute of Allergy and Infectious Diseases, and Bill & Melinda Gates Foundation.
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- 2023
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3. Prevalence and Characterization of Gastroenteritis Viruses among Hospitalized Children during a Pilot Rotavirus Vaccine Introduction in Vietnam
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Chu Thi Ngoc Mai, Le Thi Khanh Ly, Yen Hai Doan, Tomoichiro Oka, Le Thi Phuong Mai, Nguyen Tu Quyet, Tran Ngoc Phuong Mai, Vu Dinh Thiem, Lai Tuan Anh, Le Van Sanh, Nguyen Dang Hien, Dang Duc Anh, Umesh D. Parashar, Jacqueline E. Tate, and Nguyen Van Trang
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gastroenteritis viruses ,rotavirus vaccine ,Rotavin-M1 ,Vietnam ,rotavirus ,norovirus ,Microbiology ,QR1-502 - Abstract
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 ®, Meridian Bioscience, Inc., Cincinnati, OH, USA) was used to detect RV, and two multiplex real-time RT-PCR assays were used for the detection of NoV, SaV and HAstV. The prevalence of RV (single infection) was reduced from 41.6% to 22.7% (p < 0.0001) between pre- and post-vaccination periods, while the single NoV infection prevalence more than doubled from 8.8% to 21.8% (p < 0.0001). The SaV and HAstV prevalences slightly increased from 1.9% to 3.4% (p = 0.03) and 2.1% to 3.3% (p = 0.09), respectively, during the same period. Viral co-infections decreased from 7.2% to 6.0% (p = 0.24), mainly due to a reduction in RV infection. Among the genotypeable samples, NoV GII.4, SaV GI.1, and HAstV-1 were the dominant types, representing 57.3%, 32.1%, and 55.0% among the individual viral groups, respectively. As the prevalence of RV decreases following the national RV vaccine introduction in Vietnam, other viral pathogens account for a larger proportion of the remaining diarrhea burden and require continuing close monitoring.
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- 2023
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4. Anal human papillomavirus prevalence and risk factors among men who have sex with men in Vietnam
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Le Anh Tuan, MD, PhD, Kiesha Prem, PhD, Quang Duy Pham, MD, PhD, Zheng Quan Toh, PhD, Hau Phuc Tran, MD, PhD, Phuc Duy Nguyen, MSc, Chu Thi Ngoc Mai, BSc, Le Thi Khanh Ly, BSc, Van Cao, PhD, Tam-Duong Le-Ha, PhD, Nguyen Anh Tuan, PhD, Mark Jit, PhD, Kathryn Bright, BN, Marc Brisson, PhD, Thuong Vu Nguyen, MD, PhD, Suzanne Garland, MD, PhD, Dang Duc Anh, PhD, Nguyen Van Trang, PhD, and Kim Mulholland, MD, PhD
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Men who have sex with men ,MSM ,HPV ,Risk factors ,Vietnam ,Infectious and parasitic diseases ,RC109-216 - Abstract
Objectives: Men who have sex with men (MSM) are at risk of human papillomavirus (HPV)-related cancers, while published data are scarce. This study determined HPV prevalence and risk factors in MSM in Vietnam to inform HPV prevention strategies in this key population. Methods: A cross-sectional study of 799 MSM aged 16-50 years was conducted in Vietnam in 2017-2018. Information was collected on risk behaviours, and knowledge of HPV and anal cancer; rectal swabs were taken to detect anal HPV infection. An in-house polymerase chain reaction and Genoflow HPV array test kit were used for HPV detection and genotyping. Results: The median age of the study participants was 25 years (range 18-52). Overall prevalence of any HPV and HPV16/18 infection was 32.3% and 11.0%, respectively. A higher prevalence of high-risk HPV infection to all 14 types tested was found in Ho Chi Minh City (30.9%) than in Hanoi (18.4%). High-risk HPV infection was associated with inconsistent condom use and history of engaging in sex under the influence of drugs (adjusted odds ratio (aOR), 2.27; 95% CI, 1.48-10.67), as well as having multiple sexual partners (aOR, 1.01; 95% CI, 1.00–1.02). Conclusions: High-risk anal HPV infections in Vietnamese MSM were significantly associated with risky sexual behaviours. A targeted HPV vaccination strategy would have substantial benefit for MSM in Vietnam.
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- 2021
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5. Investigating and Implementing a Student Vocational Education Model for Educational Innovation
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Ho, Van-Thong, Tran, Huy-Hoang, Nguyen, Van-De, and Nguyen, Van-Trang
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The development of each student's awareness serves as the governing principle for high school vocational education programs. This awareness then becomes the driving force behind the progression of the educational process. Career education activities for students are the relationships between the objectives, contents, methods and forms of organization of educational activities that are directly and constantly influenced by the educational environment. Student career education activities are the relationships between these aspects of educational activities as determined by research into the programs, textbooks, systematization and theoretical analysis of these activities. This investigation focuses on the following areas: (1) Developing preschool and high school teachers in the province of Dong Thap to meet the criteria of the new educational program (2) Developing models of applying local educational material for students in the province of Dong Thap. Both of these initiatives are part of the Dong Thap Educational Development Project. Findings: Assess the current state of activities for students in the province of Dong Thap that are related to vocational education between 2018-2021. Develop a model for carrying out activities for students participating in vocational education in the province of Dong Thap to fulfill educational innovation requirements.
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- 2023
6. Theoretical Study of a Class of Organic D‐π‐A Dyes for Polymer Solar Cells: Influence of Various π‐Spacers
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Nguyen Van Trang, Tran Ngoc Dung, Ngo Tuan Cuong, Le Thi Hong Hai, Daniel Escudero, Minh Tho Nguyen, and Hue Minh Thi Nguyen
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d-π-a dyes ,pbdts-tznt and pbdtsf-tznt ,dts ,polymer solar cells ,pces ,dft calculations ,Crystallography ,QD901-999 - Abstract
A class of D-π-A compounds that can be used as dyes for applications in polymer solar cells has theoretically been designed and studied, on the basis of the dyes recently shown by experiment to have the highest power conversion efficiency (PCE), namely the poly[4,8-bis(5-(2-butylhexylthio)thiophen-2-yl)benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl-alt-TZNT] (PBDTS-TZNT) and poly[4,8-bis(4-fluoro-5-(2-butylhexylthio)thiophen-2-yl)benzo[1,2-b:4,5-b’]dithiophene-2,6-diyl-alt-TZNT] (PBDTSF-TZNT) substances. Electronic structure theory computations were carried out with density functional theory and time-dependent density functional theory methods in conjunction with the 6−311G (d, p) basis set. The PBDTS donor and the TZNT (naphtho[1,2-c:5,6-c]bis(2-octyl-[1,2,3]triazole) acceptor components were established from the original substances upon replacement of long alkyl groups within the thiophene and azole rings with methyl groups. In particular, the effects of several π-spacers were investigated. The calculated results confirmed that dithieno[3,2-b:2′,3′-d] silole (DTS) acts as an excellent π-linker, even better than the thiophene bridge in the original substances in terms of well-known criteria. Indeed, a PBDTS-DTS-TZNT combination forms a D-π-A substance that has a flatter structure, more rigidity in going from the neutral to the cationic form, and a better conjugation than the original compounds. The highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energy gap of such a D-π-A substance becomes smaller and its absorption spectrum is more intense and red-shifted, which enhances the intramolecular charge transfer and makes it a promising candidate to attain higher PCEs.
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- 2020
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7. High protective efficacy of probiotics and rice bran against human norovirus infection and diarrhea in gnotobiotic pigs
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Shaohua Lei, Ashwin Ramesh, Erica Twitchell, Ke Wen, Tammy Bui, Mariah Weiss, Xingdong Yang, Jacob Kocher, Guohua Li, Ernawati Giri-Rachman, Nguyen Van Trang, Xi Jiang, Elizabeth P Ryan, and Lijuan Yuan
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Diarrhea ,Probiotics ,Rice bran ,Human norovirus ,gnotobiotic pigs ,Microbiology ,QR1-502 - Abstract
Probiotics have been recognized as vaccine adjuvants and therapeutic agents to treat acute gastroenteritis in children. We previously showed that rice bran reduced human rotavirus diarrhea in gnotobiotic pigs. Human noroviruses (HuNoVs) are the major pathogens causing nonbacterial acute gastroenteritis worldwide. In this study, Lactobacillus rhamnosus GG (LGG) and Escherichia coli Nissle 1917 (EcN) were first screened for their ability to bind HuNoV P particles and virions derived from clinical samples containing HuNoV genotype GII.3 and GII.4, then the effects of LGG+EcN and rice bran on HuNoV infection and diarrhea were investigated using the gnotobiotic pig model. While LGG+EcN colonization inhibited HuNoV shedding, probiotic cocktail regimens in which rice bran feeding started 7 days prior to or 1 day after viral inoculation in the LGG+EcN colonized gnotobiotic pigs exhibited high protection against HuNoV diarrhea and shedding, characterized by significantly reduced incidence (89% versus 20%) and shorter mean duration of diarrhea (2.2 versus 0.2 days), as well as shorter mean duration of virus shedding (3.2 versus 1.0 days). In both probiotic cocktail groups, the diarrhea reduction rates were 78% compared with the control group, and diarrhea severity was reduced as demonstrated by the significantly lower cumulative fecal scores. The high protective efficacy of the probiotic cocktail regimens was attributed to stimulation of IFN-γ+ T cell responses, increased production of intestinal IgA and IgG, and maintenance of healthy intestinal morphology (manifested as longer villi compared with the control group). Therefore, probiotic cocktail regimens containing LGG+EcN and rice bran may represent highly efficacious strategies to prevent and treat HuNoV gastroenteritis, and potentially other human enteric pathogens.
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- 2016
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8. Effects of various defects on the mechanical properties of black phosphorene
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Nguyen, Danh-Truong, Le, Minh-Quy, Nguyen, Van-Trang, and Bui, Thanh-Lam
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- 2017
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9. Solving a Multi-Objective Optimization Problem of a Two-Stage Helical Gearbox with Second-Stage Double Gear Sets Using the MAIRCA Method.
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Vu, Duc-Binh, Tran, Huu-Danh, Dinh, Van-Thanh, Vu, Duong, Vu, Ngoc-Pi, and Nguyen, Van-Trang
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GEARBOXES ,HELICAL gears ,MULTIPLE criteria decision making - Abstract
This paper provides a novel application of the multi-criteria decision-making (MCDM) method to the multi-objective optimization problem (MOOP) of creating a two-stage helical gearbox (TSHG) with second-stage double gear sets (SDGSs). The aim of the study is to determine the optimum major design components for enhancing the gearbox efficiency while reducing the gearbox volume. In this work, three primary design parameters are chosen to accomplish this: the gear ratio of the first stage and the coefficients of the wheel face width (CWFW) of the first and second stages. Additionally, the study is conducted with two distinct objectives in mind: the lowest gearbox volume and the maximum gearbox efficiency. Moreover, phase 1 and phase 2, respectively, are the two stages of the MOOP. Phase 2 handles the MOOP to identify the ideal primary design factors as well as the single-objective optimization problem to minimize the difference between the variable levels. Additionally, the Multi-Attributive Ideal–Real Comparative Analysis (MAIRCA) approach is selected to deal with the MOOP. The results of the study are utilized to determine the ideal values for three crucial design parameters in order to create a TSHG with SDGSs. [ABSTRACT FROM AUTHOR]
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- 2024
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10. Genomic characterization of endemic diarrheagenic Escherichia coli and Escherichia albertii from infants with diarrhea in Vietnam.
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Iguchi, Atsushi, Takemura, Taichiro, Ogura, Yoshitoshi, Nguyen, Thi Thu Huong, Kikuchi, Taisei, Okuno, Miki, Tokizawa, Asako, Iwashita, Hanako, Pham, Hong Quynh Anh, Doan, Thi Hang, Tran, Na Ly, Tran, Thi Luong, Nguyen, Thi Hang, Tran, Thi Hien, Pham, Tuyet Ngoc Linh, Dao, Trung Duc, Vu, Thi My Hanh, Nguyen, Thi Nga, Vu, Hieu, and Nguyen, Van Trang
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ESCHERICHIA coli ,DIARRHEA ,INTESTINAL diseases ,GENOMICS ,INFANTS ,CRYPTOSPORIDIUM ,KLEBSIELLA pneumoniae - Abstract
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. Author summary: Diarrhea is a leading cause of morbidity and mortality in children under five years of age in developing countries, and diarrheagenic Escherichia coli (DEC) is a group of bacterial pathogens that cause a wide variety of intestinal diseases. To control the epidemic of DECs, it is necessary to understand the characteristics of prevalent strains in each region and propose appropriate treatment methods for them. This study reports detailed genomic analysis results of DEC-like strains isolated from infant diarrhea patients in Vietnam. The results suggested that many of the DECs prevalent in this country are uncommon types, and that Escherichia albertii, an emerging diarrheal pathogen, is the cause of diarrhea. Furthermore, comprehensive genome analysis revealed that these DECs are developing serious drug resistance. We believe that the results of this study will be the basis for improving treatment methods for patients with diarrhea and for tracking the evolution of this pathogenic group. [ABSTRACT FROM AUTHOR]
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- 2023
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11. Prevalence and risk factors for human papillomavirus infection among female sex workers in Hanoi and Ho Chi Minh City, Viet Nam: a cross-sectional study.
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Quang Duy Pham, Kiesha Prem, Tuan Anh Le, Nguyen Van Trang, Jit, Mark, Tuan Anh Nguyen, Van Cao, Tam-Duong Le-Ha, Mai Thi Ngoc Chu, Ly Thi Khanh Le, Zheng Quan Toh, Brisson, Marc, Suzanne Garland, Murray, Gerald, Bright, Kathryn, Duc Anh Dang, Hau Phuc Tran, and Mulholland, Edward Kim
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PAPILLOMAVIRUS diseases ,SEX workers ,CROSS-sectional method ,LIVING alone ,GENITAL warts ,HUMAN papillomavirus vaccines - Abstract
Objective: Female sex workers (FSWs) are at high risk of human papillomavirus (HPV) infections and cervical cancer due to their high number of sexual partners. The objectives of this study were to determine the prevalence of HPV and identify risk factors for high-risk HPV infection among FSWs in Hanoi and Ho Chi Minh City (HCMC), Viet Nam. Methods: A cross-sectional study was conducted in Hanoi and HCMC between December 2017 and May 2018. We surveyed and screened 699 FSWs aged ≥18 years for HPV infection and abnormal cytology. A multivariable modified Cox regression model was used to determine risk factors for high-risk HPV infection. Results: The overall prevalence of any HPV, high-risk HPV and HPV-16/18 infection in the 699 FSWs was 26.3%, 17.6% and 4.0%, respectively, and were similar in both cities. Multiple infections were identified in 127 participants (69.0%). HPV-52 was the most prevalent (7%), followed by HPV-58 (6%). Abnormal cytology was detected in 91 participants (13.0%). FSWs who are divorced (adjusted prevalence ratio [aPR]: 1.96, 95% confidence interval [CI]: 1.01--3.81), widowed (aPR: 3.26, 95% CI: 1.49--7.12) or living alone (aPR: 1.85, 95% CI: 1.01--3.39) were associated with a higher prevalence of high-risk HPV infection. Discussion: Almost one in five FSWs in Viet Nam are infected with high-risk HPV. This highlights the importance of prevention strategies such as HPV vaccination and screening in this high-risk group. [ABSTRACT FROM AUTHOR]
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- 2022
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12. Prevalence and Determinants of Vaginal Infection With Human Papillomavirus Among Female University Students in Vietnam.
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NGUYEN VAN TRANG, KIESHA PREM, ZHENG QUAN TOH, BUI THI VIET HA, PHAM THI NGOC LAN, HAU PHUC TRAN, QUANG DUY PHAM, NGHIA VAN KHUU, MARK JIT, DUNG THI LUU, LE THI KHANH LY, VAN CAO, TAM-DUONG LE-HA, KATHRYN BRIGHT, SUZANNE M. GARLAND, DANG DUC ANH, and KIM MULHOLLAND
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VAGINAL diseases ,HUMAN papillomavirus vaccines ,WOMEN college students ,HUMAN sexuality - Abstract
Background/Aim: Cervical cancer is the second most common malignancy among women in Vietnam, but the country is yet to introduce a national human papillomavirus (HPV) vaccine programme targeted at adolescents. We determined HPV prevalence and HPV vaccine knowledge among female university students in Vietnam. Patients and Methods: We surveyed and screened 1,491 female university students in Hanoi, Hue, and Ho Chi Minh City for their sexual behaviours, HPV knowledge and low- and high-risk HPV infection. Results: The prevalence of any HPV infection and any high-risk HPV infection were 4.2% (95%CI=3.3%- 5.4%) and 3.4% (95%CI=2.5%-4.4%), respectively. Being sexually active [adjusted prevalence ratio (aPR): 6.22; 95%CI=3.4-11.37] and having ever been pregnant (aPR: 4.82; 95%CI=1.93-12.04) were positively associated with high-risk HPV infection. Whilst 60% of participants had heard of HPV vaccine, only 4.6% had received the vaccine. Conclusion: The low HPV prevalence found in university students in Vietnam indicates that they can benefit from HPV vaccination, along with a well-designed HPV health promotion programme. [ABSTRACT FROM AUTHOR]
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- 2022
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13. Emotional quality-of-life and patient-reported limitation in sports participation in children with uncorrected congenital and acquired heart disease in healthcare-restricted settings in low- and middle-income countries.
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Kolt, Gali S, Ferdman, Barbara R, Choi, Jessica Y, Henson, Janine, Nguyen, Van-Trang, Farkas, Emily A, Nina, Vinicius JDS, Nina, Rachel VAH, CiFuentes, Renzo O, Zeman, William F, Connett, John E, and Marath, Aubyn
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- 2020
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14. Bending of boron nitride nanotubes: An atomistic study.
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Nguyen, Van-Trang, Nguyen, Danh-Truong, and Le, Minh-Quy
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BORON nitride , *NANOTUBES , *TUBE bending , *FINITE element method , *MOLECULAR dynamics - Abstract
The present work investigates through molecular dynamics finite element method with Tersoff potential the buckling behavior of boron nitride (BN) armchair and zigzag nanotubes under bending. The critical bending buckling angle, moment, and curvature are studied and discussed with respect to the tube length-diameter ratios from 10 to 50. Effects of a Stone-Wales defect in the middle tube on the bending behavior are also examined. The bending buckling mechanism is governed by the local instabilities and bond breaking in the compressive zone of the tubes. Results are useful for the design of nanocomposites and nano-devices with BN nanotubes. [ABSTRACT FROM AUTHOR]
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- 2019
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15. Isoflavones and Isoflavone Glycosides: Structural-Electronic Properties and Antioxidant Relations—A Case of DFT Study.
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Ninh The, Son, Do Minh, Thanh, and Nguyen Van, Trang
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ISOFLAVONES ,ABSTRACTION reactions ,GLYCOSIDES ,BOND energy (Chemistry) ,ISOFLAVONOIDS ,ANTIOXIDANTS - Abstract
Isoflavonoids and isoflavonoid glycosides have drawn much attention because of their antioxidant radical-scavenging capacity. Based on computational methods, we now present the antioxidant potential results of genistein (1), biochanin A (2), ambocin (3), and tectorigenin 7-O-[β-D-apiofuranosyl-(1-6)-β-D-glucopyranoside] (4). The optimized structures of the neutral and radical forms have been determined by the DFT-B3LYP method with the 6-311G(d) basis set. From the findings and thermodynamic point of view, the ring B system of isoflavones is considered as an active center in facilitating antioxidant reactions. Antioxidant activities are mostly driven by O-H bond dissociation enthalpy (BDE) following hydrogen atom transfer (HAT) mechanism. Antioxidant ability can be arranged in the following order: compounds (4) > (3) > (2) > (1). Of comprehensive structural analysis, flavonoids with 4′-methylation and 6-methoxylation, especially 7-glycosylation would claim responsibility for antioxidant enhancement. [ABSTRACT FROM AUTHOR]
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- 2019
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16. IMPACT OF RARE EARTH OXIDES ON THE STRUCTURE AND ELECTRICAL PROPERTIES OF ZnO-Bi2O3−BASED VARISTOR CERAMICS: A COMPARATIVE ANALYSIS OF Y2O3 AND CeO2
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Nguyen Trung Huy, Nguyen Van Trang, Cao Thi Hong, Nguyen Thi Xuyen, Vo Thi Kieu Anh, Nguyen Quang Duong, Nguyen Tuan Anh, Le Dang Quang, Do Quang Tham
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electrical properties ,rare earth oxides ,znobi2o3-based varistor ,ceo2 ,y2o3 ,Technology ,Social sciences (General) ,H1-99 - Abstract
Zinc oxide (ZnO)-based varistor ceramics, incorporating varying amounts of Y2O3/CeO2, were fabricated through a twostep solid-state reaction method involving pre-calcination and subsequent sintering processes. ZnO powder and corresponding additives served as raw materials in the production. The investigation of phase composition, microstructure, and electrical properties employed techniques such as X-ray diffractometry (XRD), scanning electron microscopy (SEM), and direct current electrical measurement. The findings revealed that varistor ceramics sintered at 950°C, using powder pre-calcined at 800°C and doped with an appropriate amount of Y2O3, exhibited enhanced electrical properties. Conversely, the introduction of varying concentrations of CeO2 did not contribute to the improvement of the electrical characteristics. The CeO2-doped samples displayed lower breakdown voltages and nonlinear coefficients compared to the undoped sample (M0). The addition of Y2O3 proved effective in improving the nonlinear coefficient but resulted in a decrease in the breakdown voltage withstand capability of the samples. A Y2O3 content of 0.5% was identified as a suitable compromise, balancing both factors. Notably, ZnO varistors doped with 0.5 mol% Y2O3 demonstrated optimal comprehensive electrical properties, featuring a breakdown field of 620 V/mm and a nonlinear coefficient of 45. These results suggest that Y2O3 doping holds promise as a viable strategy for achieving varistor ceramics with outstanding electrical performance.
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- 2024
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17. HIỆU QUẢ CỦA NƯỚC NÓNG TRONG PHÒNG NGỪA BỆNH CHAI BÔNG DO TUYẾN TRÙNG APHELENCHOIDES BESSEYI GÂY RA TRÊN CÂY HUỆ TRẮNG VÙNG ĐỒNG BẰNG SÔNG CỬU LONG
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Cúc Nguyễn Thị Thu, Trần Minh Trung, Nguyễn Văn Tràng, Lâm Minh Đăng, Marc Pilon, and Nguyễn Thanh Sơn
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Aphelenchoides besseyi ,cây huệ trắng ,đồng bằng sông Cửu Long ,nước nóng ,Polianthes tuberosa ,sự lưu tồn ,Science - Abstract
Huệ trắng (Polianthes tuberosa) là một loại cây hoa được trồng từ củ, có giá trị kinh tế cao của nhiều vùng thuộc đồng bằng sông Cửu Long (ĐBSCL). Tuy nhiên, cây huệ thường bị nhiễm bệnh chai bông do Aphelenchoides besseyi gây ra, loài tuyến trùng này lưu tồn trong củ và có thể gây thất thu năng suất trầm trọng cho cây huệ. Bài báo này trình bày các nghiên cứu so sánh hiệu quả của nước nóng và các hóa chất bảo vệ thực vật trong việc xử lý củ để phòng trừ bệnh chai bông trên cây huệ. Kết quả cho thấy biện pháp xử lý củ với nước nóng có hiệu quả cao nhất.
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- 2010
18. 1620: IMPACT OF SURGERY BY A VISITING TEAM ON QUALITY OF LIFE INDICATORS IN PATIENTS WITH CONGENITAL OR ACQUIRED HEART DISEASE IN NATIONS WITH LIMITED HEALTHCARE RESOURCES.
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Marath, Aubyn, Schiff, Laura, Gustafson, Chrisanna, Henson, Janine, Nguyen, Van-Trang, Connett, John, Rudser, Kyle, Lowry, Susan, Kochilas, Lazaros, and St. Louis, James
- Published
- 2013
19. 1650: A CARDIOSTART (CS) PERFORMANCE AND COMPLIANCE SCORING SYSTEM FOR EMERGING PAEDIATRIC AND ADULT CARDIOTHORACIC AND VASCULAR HEALTHCARE PROGRAMMMES.
- Author
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Marath, Aubyn, Schiff, Laura, Gustafson, Chrisanna, Nguyen, Van-Trang, Connett, John, Rudser, Kyle, Lowry, Susan, Henson, Janine, Kochilas, Lazaros, and St. Louis, James
- Published
- 2013
20. Transcervical approach for carotid artery stenting without flow reversal: A case report
- Author
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Nguyen-Luu Giang, MD, Tran Chi Cuong, MD, PhD, Le Minh Thang, MD, Ngo Minh Tuan, MD, Nguyen-Dao Nhat Huy, MD, Duong-Hoang Linh, MD, Mai-Van Muong, MD, Do Duc Thang, MD, Nguyen-Van Trang, MD, and Nguyen Minh Duc, MD
- Subjects
Transcervical approach ,Carotid artery stenting ,Ischemic stroke ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 - Abstract
ABSTRACT: Current treatment options for high-risk patients with severe carotid artery stenosis include transcarotid artery revascularization, transfemoral carotid artery stenting, and carotid endarterectomy. Transfemoral carotid artery stenting is associated with high perioperative stroke risk, and recent studies and trials have identified transcarotid artery revascularization as a new technique able to minimize the stroke risk associated with high-risk procedures. Moreover, the transcervical approach allows easy access to the carotid artery in cases with an anatomically tortuous aortic arch. Therefore, determining the optimal approach to achieve arterial access during carotid stenting is important for successful procedures and positive outcomes. We report a clinical case of ischemic stroke due to severe stenosis of the left internal carotid artery indicated for stent deployment. After transfemoral carotid artery stenting failure, the patient's symptoms progressed from minor stroke to hemiplegia and Broca's aphasia. The transcervical approach was used to perform transcarotid artery revascularization after several days. The procedure was both safe and prevented recurrent stroke occurrence. Although transfemoral access is the classic approach used for carotid stenting, the transcervical approach can be used as an alternative and safe choice in cases with complex vascular anatomy, such as the one described here.
- Published
- 2022
- Full Text
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21. Psychological ownership and knowledge sharing: Key psychological drivers of sustainable tourist behavior.
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Nguyen TH, Nguyen GT, Tučková Z, and Hoang SD
- Subjects
- Humans, Male, Female, Adult, Intention, Motivation, Vietnam, Social Media, Middle Aged, Trust, Young Adult, Conservation of Natural Resources, Knowledge, Ownership, Tourism
- Abstract
As the green transformation sweeps across industries in the digital age, tourism stakeholders face a pressing need to utilize online platforms and digital influencers for sustainability messaging. Drawing on the Motivation-Opportunity-Ability framework, this study investigates the influence of green ownership psychology and green knowledge sharing on tourists' repatronage intentions. It focuses on the mediating role of cooperative green activity programs and the moderating impact of tourists' green trust in social media influencers. Results from a two-wave survey of 602 tourists in Vietnam show that green practices directly increase repatronage intentions. Cooperative green activity programs significantly mediate this relationship, enhancing the impact of green marketing practices on repatronage intentions. Furthermore, tourists' green trust in social media influencers is a crucial moderating factor. It increases the effectiveness of green ownership psychology and green knowledge sharing in influencing repatronage intentions through cooperative green activity programs. The study highlights how the emotional and cognitive aspects of green marketing contribute to tourists' decisions to revisit or continue using tourism services. Offering original insights into the interplay of these elements in green marketing within the tourism industry, this research enriches the application of the Motivation-Opportunity-Ability framework. It provides valuable implications for tourism companies aiming to foster sustainable practices and enhance customer loyalty, highlighting the role of digital influencer engagement and cooperative sustainability initiatives in green marketing strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2025
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22. Novel Thiosemicarbazone Quantum Dots in the Treatment of Alzheimer's Disease Combining In Silico Models Using Fingerprints and Physicochemical Descriptors.
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Minh Quang N, Tran Thai H, Le Thi H, Duc Cuong N, Hien NQ, Hoang D, Ngoc VTB, Ky Minh V, and Van Tat P
- Abstract
Searching for thiosemicarbazone derivatives with the potential to inhibit acetylcholinesterase for the treatment of Alzheimer's disease (AD) is an important current goal. The QSAR
KPLS , QSARANN , and QSARSVR models were constructed using binary fingerprints and physicochemical (PC) descriptors of 129 thiosemicarbazone compounds screened from a database of 3791 derivatives. The R2 and Q2 values for the QSARKPLS , QSARANN , and QSARSVR models are greater than 0.925 and 0.713 using dendritic fingerprint (DF) and PC descriptors, respectively. The in vitro pIC50 activities of four new design-oriented compounds N1 , N2 , N3 , and N4 , from the QSARKPLS model using DFs, are consistent with the experimental results and those from the QSARANN and QSARSVR models. The designed compounds N1 , N2 , N3 , and N4 do not violate Lipinski-5 and Veber rules using the ADME and BoiLED-Egg methods. The binding energy, kcal mol-1 , of the novel compounds to the 1ACJ-PDB protein receptor of the AChE enzyme was also obtained by molecular docking and dynamics simulations consistent with those predicted from the QSARANN and QSARSVR models. New compounds N1 , N2 , N3 , and N4 were synthesized, and the experimental in vitro pIC50 activity was determined in agreement with those obtained from in silico models. The newly synthesized thiosemicarbazones N1 , N2 , N3 , and N4 can inhibit 1ACJ-PDB, which is predicted to be able to cross the barrier. The DFT B3LYP/def-SV(P)-ECP quantization calculation method was used to calculate EHOMO and ELUMO to account for the activities of compounds N1 , N2 , N3 , and N4 . The quantum calculation results explained are consistent with those obtained in in silico models. The successful results here may contribute to the search for new drugs for the treatment of AD., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)- Published
- 2023
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- View/download PDF
23. Quantitative Structure-Property Relationships for the Electronic Properties of Polycyclic Aromatic Hydrocarbons.
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Nguyen LH and Truong TN
- Abstract
This study presents a development in quantitative structure-property relationships (QSPRs) for research in organic semiconductor materials by introducing a new structural descriptor called "degree of π-orbital overlap" based on two-dimensional structure information of aromatic molecules. Application of this method to predict the electronic properties of polycyclic aromatic hydrocarbon (PAH) molecules, which are known to be the core component of many organic semiconductor materials, is presented. Results demonstrated that QSPRs based on the new descriptor can predict rather accurate band gaps, ionization potentials and electron affinities for a large number of PAHs compared to those explicitly calculated by density functional theory method. This research opens new possibilities for developing QSPRs for other organic semiconductor classes in future., Competing Interests: The authors declare no competing financial interest.
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- 2018
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24. Fabrication of Phosphor-Free III-Nitride Nanowire Light-Emitting Diodes on Metal Substrates for Flexible Photonics.
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Rajan Philip M, Choudhary DD, Djavid M, Bhuyian MN, Bui THQ, Misra D, Khreishah A, Piao J, Nguyen HD, Le KQ, and Nguyen HPT
- Abstract
In this paper, we report our study on high-performance III-nitride nanowire light-emitting diodes (LEDs) on copper (Cu) substrates via the substrate-transfer process. Nanowire LED structures were first grown on silicon-on-insulator (SOI) substrates by molecular beam epitaxy. Subsequently, the SOI substrate was removed by combining dry- and wet-etching processes. Compared to conventional nanowire LEDs on Si, the nanowire LEDs on Cu exhibit several advantages, including more efficient thermal management and enhanced light-extraction efficiency (LEE) because of the usage of metal reflectors and highly thermally conductive metal substrates. The LED on Cu, therefore, has stronger photoluminescence, electroluminescence intensities, and better current-voltage characteristics compared to the conventional nanowire LED on Si. Our simulation results further confirm the improved device performance of LEDs on Cu, compared to LEDs on Si. The LEE of the nanowire LED on Cu is nine times higher than that of the LED on Si at the same nanowire radius of 60 nm and spacing of 130 nm. Moreover, by engineering the device-active region, we achieved high-brightness phosphor-free LEDs on Cu with highly stable white-light emission and high color-rendering index of ∼95, showing their promising applications in general lighting, flexible displays, and wearable applications., Competing Interests: The authors declare no competing financial interest.
- Published
- 2017
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25. A dose-escalation safety and immunogenicity study of a new live attenuated human rotavirus vaccine (Rotavin-M1) in Vietnamese children.
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Dang DA, Nguyen VT, Vu DT, Nguyen TH, Nguyen DM, Yuhuan W, Baoming J, Nguyen DH, and Le TL
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- Administration, Oral, Adolescent, Adult, Antibodies, Viral blood, Drug-Related Side Effects and Adverse Reactions epidemiology, Female, Human Experimentation, Humans, Immunoglobulin A blood, Infant, Male, Middle Aged, Rotavirus Vaccines administration & dosage, Vaccines, Attenuated administration & dosage, Vaccines, Attenuated adverse effects, Vaccines, Attenuated immunology, Vietnam, Virus Shedding, Young Adult, Rotavirus Infections prevention & control, Rotavirus Vaccines adverse effects, Rotavirus Vaccines immunology, Vaccination methods
- Abstract
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. The vaccine was administered in low titer (10(6.0)FFU/dose) on a 2-dose schedule given 2 months apart (Group 2L) and on a 3-dose schedule given 1 month apart (Group 3L) and in high titer (10(6.3)FFU/dose) in 2 doses 2 months apart (Group 2H) and in 3 doses 1 month apart (Group 3H). For comparison, 40 children (group Rotarix™) were given 2 doses of the lyophilized Rotarix™ vaccine (10(6.5)CCID(50)/dose) 1 month apart. All infants were followed for 30 days after each dose for clinical adverse events including diarrhea, vomiting, fever, abdominal pain, irritability and intussusception. Immunogenicity was assessed by IgA seroconversion and viral shedding was monitored for 7 days after administration of each dose. Two doses of Rotavin-M1 (10(6.3)FFU/dose) were well tolerated in adults. Among infants (average 8 weeks of age at enrollment), administration of Rotavin-M1 was safe and did not lead to an increased rate of fever, diarrhea, vomiting or irritability compared to Rotarix™, indicating that the candidate vaccine virus had been fully attenuated by serial passages. No elevation of levels of serum transaminase, blood urea, or blood cell counts were observed. The highest rotavirus IgA seroconversion rate (73%, 95%CI (58-88%)) was achieved in group 2H (2 doses--10(6.3)FFU/dose, 2 months apart). The 2 dose schedules performed slightly better than the 3 dose schedules and the higher titer doses performed slightly better than the lower titer doses. These rates of seroconversion were similar to that of the Rotarix™ group (58%, 95%CI (42-73%)). However more infants who received Rotarix™ (65%) shed virus in their stool after the first dose than those who received Rotavin-M1 (44-48%) (p<0.05) and the percent shedding decreased after subsequent doses of either vaccine. Rotavin-M1 vaccine is safe and immunogenic in Vietnamese infants. A trial in progress will assess the safety, immunogenicity and efficacy of Rotavin-M1 (2 doses at 10(6.3)FFU/dose) in a larger number of infants. The trial registration numbers are NCT01375907 and NCT01377571., (Copyright © 2011 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
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