Facile synthesis of SnO2eZnO coreeshell nanowires for enhanced ethanol-sensing performance

Dang Thi Thanh Le,Do Dang Trung,Nguyen Duc Chinh,Bui Thi Thanh Binh,Hoang Si Hong,Nguyen Van Duya,Nguyen Duc Hoa,Nguyen Van Hieu 한국물리학회 2013 Current Applied Physics Vol.13 No.8

The design of coreeshell heteronanostructures is powerful tool to control both the gas selectivity and the sensitivity due to their hybrid properties. In this work, the SnO2eZnO coreeshell nanowires (NWs) were fabricated via two-step process comprising the thermal evaporation of the single crystalline SnO2 NWs core and the spray-coating of the grainy polycrystalline ZnO shell for enhanced ethanol sensing performance. The as-obtained products were investigated by X-ray diffraction, scanning electron microscopy,and photoluminescence. The ethanol gas-sensing properties of pristine SnO2 and ZnOeSnO2 core eshell NW sensors were studied and compared. The gas response to 500 ppm ethanol of the coreeshell NW sensor increased to 33.84, which was 12.5-fold higher than that of the pristine SnO2 NW sensor. The selectivity of the coreeshell NW sensor also improved. The response to 100 ppm ethanol was about 14.1,whereas the response to 100 ppm liquefied petroleum gas, NH3, H2, and CO was smaller, and ranged from 2.5 to 5.3. This indicates that the coreeshell heterostructures have great potential for use as gas sensing materials.

Impact of long COVID-19 on posttraumatic stress disorder as modified by health literacy: an observational study in Vietnam

Han Thi Vo,Tien Duc Dao,Tuyen Van Duong,Tan Thanh Nguyen,Binh Nhu Do,Tinh Xuan Do,Khue Minh Pham,Vinh Hai Vu,Linh Van Pham,Lien Thi Hong Nguyen,Lan Thi Huong Le,Hoang Cong Nguyen,Nga Hoang Dang,Trung 질병관리청 2024 Osong Public Health and Research Persptectives Vol.15 No.1

Objectives: The incidence of posttraumatic stress disorder (PTSD) has increased, particularly among individuals who have recovered from coronavirus disease 2019 (COVID-19) infection. Health literacy is considered a “social vaccine” that helps people respond effectively to the pandemic. We aimed to investigate the association between long COVID-19 and PTSD, and to examine the modifying role of health literacy in this association.Methods: A cross-sectional study was conducted at 18 hospitals and health centers in Vietnam from December 2021 to October 2022. We recruited 4,463 individuals who had recovered from COVID-19 infection for at least 4 weeks. Participants provided information about their sociodemographics, clinical parameters, health-related behaviors, health literacy (using the 12-item short-form health literacy scale), long COVID-19 symptoms and PTSD (Impact Event Scale-Revised score of 33 or higher). Logistic regression models were used to examine associations and interactions.Results: Out of the study sample, 55.9% had long COVID-19 symptoms, and 49.6% had PTSD. Individuals with long COVID-19 symptoms had a higher likelihood of PTSD (odds ratio [OR], 1.68; 95% confidence interval [CI], 1.63–2.12; p<0.001). Higher health literacy was associated with a lower likelihood of PTSD (OR, 0.98; 95% CI, 0.97–0.99; p=0.001). Compared to those with long COVID-19 symptoms and the lowest health literacy score, those with long COVID-19 symptoms and a 1-point health literacy increment had a 3% lower likelihood of PTSD (OR, 0.97; 95% CI, 0.96–0.99; p=0.001).Conclusion: Health literacy was found to be a protective factor against PTSD and modified the negative impact of long COVID-19 symptoms on PTSD.

Chitosan Oligomer as a Hopeful Adjuvant for H5n1 Influenza Vaccine

( Le Van Hiep ),( Mai Thi Thanh ),( Dang Thi Hong Van ),( Vo Thi Phuong Khanh ),( Nguyen Anh Dzung ) 한국키틴키토산학회 2008 한국키틴키토산학회지 Vol.13 No.1

Effect of Chitosan oligomer (dp = 8-16) and other adjuvant such as: Aluminum phosphate (AlPO4) and Freund on immune response of H5N1 influenza vaccine in Swiss mice has been investigated. The Swiss mice were twice vaccinated alternative 20 days with dose 0.1 ml/mouse. After 10, 20 and 30 days, the immune response of Swiss mice with H5N1 vaccine was detected. The result showed that after 20 days of the first vaccination, immune response of chitosan oligomer test and Freund was 100%, but Freund test reduced 80% after 30days of vaccination. Meanwhile, immune response of the control and AlPO4 test was very low, only 40%. The Effect of chitosan oligomer and the others on antibody titer has been also investigated. The result showed that the antibody titer of chitosan oligomer test was 60 HIU (Hemagglutination units), 70 HIUs after 10 and 20 days of the first vaccination, and increased up to 112 HIUs after 10 days of the second vaccination and the antibody titer of the chitosan oligomer test was higher than the others. Therefore, chitosan oligomer is a hopeful adjuvant for H5N1 influenza vaccine.

Factors Affecting Logistics Capabilities for Logistics Service Providers: A Case Study in Vietnam

Dinh Dao DANG,Dieu Linh HA,Van Bao TRAN,Van Tuan NGUYEN,Thi Lien Huong NGUYEN,Thuy Hong DANG,Thi Thai Ha LE 한국유통과학회 2021 The Journal of Asian Finance, Economics and Busine Vol.8 No.5

This study aimed to investigate the factors affecting Logistics capabilities for Logistics Service Providers in Vietnam. Researchers inherited and developed based on previous research to focus on analyzing and evaluating dynamics, measuring Logistics capabilities, and the factors affecting Logistics capabilities for Logistics Service Providers. The logistics capabilities Model is used based on three factors: customer demand management capability, innovation capability, and information management capability. The empirical analysis used data from the survey data of l90 managers of Logistics Service Providers in Hai Phong, Ho Chi Minh City, Da Nang, Hue, Hanoi with reliable tools (SPSS 26.0 software). The data were analyzed by frequencies, percentages, means, Pearson’s Linear Correlation Coefficient, exploratory factor analysis, and multi-linear regression model based on the survey data. The research results identified the following factors affecting Logistics capabilities for Logistics Service Providers: innovation capability has the strongest impact on Logistics capabilities; customer demand management capability has the following strong effects on Logistics capabilities; and finally, information management capability that affects Logistics capabilities. There is also a positive relationship between all factors and Logistics capabilities. Several recommendations are further suggested to enhance to improve Logistics capabilities for Logistics Service Providers in Vietnam.

Correlations between abnormalities of morphological details and DNA fragmentation in human sperm

Nguyen, Hiep Tuyet Thi,Dang, Hong Nhan Thi,Nguyen, Thai Thanh Thi,Nguyen, Trung Van,Dang, Thuan Cong,Nguyen, Quoc Huy Vu,Le, Minh Tam The Korean Society for Reproductive Medicine 2022 Clinical and Experimental Reproductive Medicine Vol.49 No.1

Objective: As the associations of sperm DNA fragmentation with morphology have not been examined in detail, this study aimed to investigate the relationship between abnormalities of morphological details and DNA integrity in human sperm. Methods: In this cross-sectional study, men from infertile couples were enrolled at Hue Center for Reproductive Endocrinology and Infertility, Vietnam. Conventional semen parameters, including morphological details, were analyzed following the World Health Organization 2010 criteria. Sperm DNA fragmentation was evaluated using a sperm chromatin dispersion assay. The relationships and correlations between semen parameters, sperm morphology, and the type of halosperm and the DNA fragmentation index (DFI) were analyzed. Results: Among 130 men in infertile couples, statistically significant differences were not found in the sperm halo type between the normal and abnormal sperm morphology groups. The percentage of round-head spermatozoa was higher in the DFI >15% group (16.98%±12.50%) than in the DFI ≤15% group (13.13% ±8.82%), higher values for amorphous heads were found in the DFI >15% group, and lower values for tapered heads were observed in the DFI ≤15% group; however, these differences were not statistically significant. Small-halo sperm and the DFI were positively correlated with round-head sperm (r=0.243, p=0.005 and r=0.197, p=0.025, respectively). Conclusion: The rate of general sperm morphological abnormalities in semen analysis was not related to sperm DNA integrity. However, round sperm heads were closely associated with sperm DNA fragmentation.

Profitability and the Distance to Default: Evidence from Vietnam Securities Market

Van Thuy Thi VU,Nhung Hong DO,Hung Ngoc DANG,Tram Ngoc NGUYEN 한국유통과학회 2019 The Journal of Asian Finance, Economics and Busine Vol.6 No.4

The paper examines the influence of profitability on distance to default (DD) in Vietnam securities market. The investigated sampl e consists of 211 companies listed on HOSE during 18 years from 2010 to 2017. We apply KMV model to calculate distance to d efault and use both macroeconomics factors and firm specific factors as independent variables. Using General Least Squared (GL S) method, we find evidence to confirm the positive relationship between profitability and distance to default. This result showed t hat, although profitability did not directly reflect the cash flow generated, a good profitable enterprise would be an important facto r to help facilitate and generate cash flow and at the same time debt was guaranteed when it was due. Besides, the test results rev ealed that the financial structure and sales on assets have the inverse effect on the distance to default at the significance level o f 5%. The results also revealed that a group of macro factors had an influence on the distance to default of businesses, including spre ad, GDP and trade balance (via exchange rates). Gross domestic income had certain impacts on the distance to default of businesse s. This was also a basic indicator measuring the national economic cycle.

Magnetism of Semi-Heusler Compounds CoMnSb<SUB>1-x</SUB>M<SUB>x</SUB> (M = Si, Al, Bi)

Dang Van Son,Hoang Duc Quang,Song Yeal Young,Phung Thi Hong Van 한국자기학회 2006 한국자기학회 학술연구발표회 논문개요집 Vol.16 No.1

Management of Antibiotic-Resistant Helicobacter pylori Infection: Perspectives from Vietnam

Vu Van Khien,Duong Minh Thang,Tran Manh Hai,Nguyen Quang Duat,Pham Hong Khanh,Dang Thuy Ha,Tran Thanh Binh,Ho Dang Quy Dung,Tran Thi Huyen Trang,Yoshio Yamaoka 거트앤리버 소화기연관학회협의회 2019 Gut and Liver Vol.13 No.5

Antibiotic resistance is the most important factor leading to the failure of eradication regimens. This review focuses on the prevalence of Helicobacter pylori primary and secondary resistance to clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and multidrug in Vietnam. We searched the PubMed, EMBASE, Vietnamese National Knowledge Infrastructure, and Vietnamese Biomedical databases from January 2000 to December 2016. The search terms included the following: H. pylori infection, antibiotic (including clarithromycin, metronidazole, amoxicillin, levofloxacin, tetracycline, and multidrug) resistance in Vietnam. The data were summarized in an extraction table and analyzed manually. Finally, Excel 2007 software was used to create charts. Ten studies (three studies in English and seven in Vietnamese) were included in this review. A total of 308, 412, 523, 408, 399, and 268 H. pylori strains were included in this review to evaluate the prevalence of H. pylori primary resistance to amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and multidrug resistance, respectively. Overall, the primary resistance rates of amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and multidrug resistance were 15.0%, 34.1%, 69.4%, 27.9%, 17.9% and 48.8%, respectively. Secondary resistance rates of amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and multidrug resistance were 9.5%, 74.9%, 61.5%, 45.7%, 23.5% and 62.3%, respectively. In Vietnam, primary and secondary resistance to H. pylori is increasing over time and affects the effectiveness of H. pylori eradication.

Regional Differences in Mitochondrial Anti-oxidant State during Ischemic Preconditioning in Rat Heart

Thu, Vu Thi,Cuong, Dang Van,Kim, Na-Ri,Youm, Jae-Boum,Warda, Mohamad,Park, Won-Sun,Ko, Jae-Hong,Kim, Eui-Yong,Han, Jin The Korean Society of Pharmacology 2007 The Korean Journal of Physiology & Pharmacology Vol.11 No.2

Ischemic preconditioning (IPC) is known to protect the heart against ischemia/reperfusion (IR)-induced injuries, and regional differences in the mitochondrial antioxidant state during IR or IPC may promote the death or survival of viable and infarcted cardiac tissues under oxidative stress. To date, however, the interplay between the mitochondrial antioxidant enzyme system and the level of reactive oxygen species (ROS) in the body has not yet been resolved. In the present study, we examined the effects of IR- and IPC-induced oxidative stresses on mitochondrial function in viable and infarcted cardiac tissues. Our results showed that the mitochondria from viable areas in the IR-induced group were swollen and fused, whereas those in the infarcted area were heavily damaged. IPC protected the mitochondria, thus reducing cardiac injury. We also found that the activity of the mitochondrial antioxidant enzyme system, which includes manganese superoxide dismutase (Mn-SOD), was enhanced in the viable areas compared to the infarcted areas in proportion with decreasing levels of ROS and mitochondrial DNA (mtDNA) damage. These changes were also present between the IPC and IR groups. Regional differences in Mn-SOD expression were shown to be related to a reduction in mtDNA damage as well as to the release of mitochondrial cytochrome c (Cyt c). To the best of our knowledge, this might be the first study to explore the regional mitochondrial changes during IPC. The present findings are expected to help elucidate the molecular mechanism involved in IPC and helpful in the development of new clinical strategies against ischemic heart disease.

Study on the Characteristics of X-ray Spectra in Imaging Diagnosis Using Monte Carlo Simulations

Khanh Ai Tran,Loan Thi Hong Truong,Nhon Van Mai,Phuong Nguyen Dang,Dung Thi Thuy Vo 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.69 No.7

X-rays are widely used in diagnostic imaging such as radiography and computed tomography. An understanding of the X-ray spectrum is essential for estimating the dose absorbed by the patient and for improving image quality. In this research, X-ray emission spectra were investigated by using two different approaches: a Monte Carlo method using the MCNP5 code and a semi-empirical calculation with SpekCalc software. The results were compared with each other to validate the Monte Carlo simulation of the X-ray spectra, so that the simulation model can be applied to estimating the dose rate distribution in X-ray imaging. The obtained results show good agreement between the two approaches, but some divergence is still observed in the characteristic X-ray peaks. In addition, the influence of X-ray tube parameters such as the peak voltage, filter, anode angle and target material on of the beam quality was investigated.