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Mobilization of Arsenic in Groundwater in the Southern Hanoi City (Vietnam) as Studied by Isotopic and Related Techniques

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Journal of Environmental Protection 2013年第7期4卷 68-74页

作者： Dang Duc nhan Doan Van Canh Pham Quy nhan Nguyen thi thanh Thuy Dinh thi Bich Lieu Vo thi Anh Dang Anh Minh Center for Water Resources Management Hanoi Vietnam Hanoi University of Mining and Geology Hanoi Vietnam Institute for Nuclear Science and Technology Hanoi Vietnam Vietnam Association of Hydrogeology Hanoi Vietnam Vietnam Atomic Energy Institute Hanoi Vietnam

Sixteen samples of surface and groundwater from the most southern part of the Hanoi city (Vietnam) has been taken and analyzed for the soluble major ions, namely Na+, K+, , Ca2+, Mg2+, Cl-, , and arsenic as well as molybdenum content along with isotopic composition of deuterium and oxygen (δ2H and δ18O), tritium activity, and δ13C in DIC. The stable isotopic composition of groundwater indicates the water in that area is recharged from the local meteoric and theRed River’s water sources. The mean residence time of the groundwater should be before 60-ies of the past century as its 3H activity ranged from LOD of the analytical technique (0.4 TU) to 2.1 TU only implying that As would not be related to its recent application. The concentrations of As in the water samples is weakly correlated with those of Fe2+ (R2 = 0.08) but it strongly did with the concentrations of bicarbonate (R2 = 0.80). Thus, bicarbonate seems to liberate As adsorbed on hydrous ferric oxides (Hfo) into water through the displacement mechanism. The surface adsorption-desorption of As could be proven by a strong correlation between As and Mo concentrations (R2 = 0.77). The bicarbonate formation in groundwater was thought to be, partly, due to the bio-mineralization of natural organic matter (NOM) by bacteria followed by the dissolution of calcite and/or dolomite present in the sediments. Evidence for the NOM bio-mineralization was found in the close relationship between δ13C and the concentration of bicarbonate in water. Therefore, the mobilization of As in groundwater of bicarbonate type in the southern part of Hanoi city seems to be not only due to the reductive dissolution of the Hfo but the bicarbonate displacement also should be considered.

关键词： Arsenic Mobilization Isotopic Technique Groundwater Nom Bio-Mineralization As-Bicarbonate Displacement

Changes of Food Expenditure and Food Consumption of People Living in Ba Vi District, Hanoi, Vietnam from 1999 to 2013

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Health 2015年第12期7卷 1696-1702页

作者： Huong Le thi Phuong Le Hong thanh Nguyen Hoang giang Nguyen Thu Xuan Le thi thanh Chuc Nguyen thi Kim Nga thi Thu Vu Institute for Preventive Medicine and Public Health Hanoi Medical University Hanoi Vietnam

Background: During the nutrition transition period which began in the early 1990s in Vietnam, dietary intake had been changed significantly because of changes in lifestyle and living standard. Objectives: this paper aims to describe the trend for food expenditure and the frequency of meat consumption in households in Ba Vi district, Hanoi, Vietnam from 1999 to 2013. Methods: this is a longitudinal study conducted in Ba Vi district, Hanoi. Semi-annual, face-to face interviews were conducted by well-trained interviewers with 11,922 households to collect data of the household’s income, spending for food and meat consumption. Chi-square test for trend was performed to evaluate the changes of food expenditure over the years. P-value under 0.05 was considered statistically significant. Results: There were ten times increase in household’s mean income and five times increase in mean food expenditure from 1999 to 2013. The percentage of household food expenditure per total family expenditure was really high (55% in 2013). The percentage of rice expenditure per total food expenditure decreased dramatically from 59.9% in 1999 to 33.1% in 2013 while spending for other animal-based, high-protein food was an upward trend, particularly meat (10.7% in 1999 to 24.2% in 2013). The percentage of rice expenditure in well-off households was lower than poor households (55% vs. 61.8% in 1999 and 31.4% vs. 36.5% in 2013). However, the percentage of spending for meat in well-off households were much higher than that of poor households (>10%). Conclusion: Our finding indicated that mean income and food expenditure, particularly meat intake, of households had increased dramatically from 1999 to 2013. The increase of meat intake requires reallocation and direction of Vietnam public health funding and strategy.

关键词： Vietnam Income Food Expenditure Meat Consumption

Direct Structural Evidences of Epitaxial Growth Ge<SUB>1-X</SUB>Mn<SUB>X</SUB>Nanocolumn Bi-Layers on Ge(001)

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Materials Sciences and Applications 2015年第6期6卷 533-538页

作者： thi giang Le Hong Duc University Thanh Hoa City Vietnam

Molecular Beam Epitaxy (MBE) system equipped with in-situ Reflection High-Energy Electron Diffraction (RHEED) has been used for (Ge, Mn) thin film growth and monitoring the surface morphology and crystal structure of thin films. Based on the observation of changes in RHEED patterns during nanocolumn growth, we used a real-time control approach to realize multilayer structures that consist of two nanocolumn layers separated by a Ge barrier layer. Transmission Electron Microscopy (TEM) has been used to investigate the structural properties of the GeMn nanocolumns and GeMn/Ge nanocolumns bi-layers samples.

关键词： GeMn Diluted Magnetic Semiconductors Muti-Layers GeMn Nanocolumns thin Film Epitaxial Growth

Pattern of smoking cessation and its associated factors in Vietnam

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Health 2012年第6期4卷 289-296页

作者： Le thi Huong Hoang Van Minh Kim Bao giang Le thi thanh Xuan Vu thi Thu Nga Pham Quynh Nga Phan thi Hai Jason Hsia Center for Disease Control and Prevention Atlanta USA Institute for Preventive Medicine and Public Health Hanoi Medical University Hanoi Vietnam Vietnam Steering Committee on Smoking and Health (VINACOSH) Hanoi Vietnam World Health Organization Office in Vietnam Hanoi Vietnam

Background: Even though the number of research on tobacco in Vietnam has recently increased rapidly, there remains a lack of reporting on the pattern of quit smoking and its correlates. It is necessary to have scientific evidence on this issue to help the policy makers and the Public Health sector to have appropriate intervention program to enhance the smoke cessation smoke program and improve the health status of the smokers. this study aims to: (1) Describe the pattern of smoking cessation in Vietnam 2010. (2) Examine the association between smoking cessation with some associated factors in Vietnam 2010. Methods: Data used in this paper were obtained from the Global Adult Tobacco Survey (GATS) conducted in Vietnam in 2010. A total of 11,142 households were selected for this survey using a two-phase sampling design analogous to a three-stage stratified cluster sampling. Both descriptive and analytical statistical analyses were carried out. Multivariate logistic regression modeling was performed to examine the association between the patterns of quit daily;quit smoke;attempt to quit and intend to quit among smokers with relevant factors. Results: The prevalence of the different type of cessation among male and female were 23.3% and 28.6% for quit daily;19.1% and 1.0% for quit;55.6% and 44.4% for attempt to quit and 29.6% and 19.3% for intend to quit respectively. The prevalence of quit daily and quit increased with age whereas attempt to quit decreased with age. Prevalence of cessation was highest among the group who were asked about smoking tobacco by health care providers. Some determinants of quit daily and quit include age, area, and knowledge of illnesses caused by smoking. There was no association between attempt and intend to quit with any socio-characteristic except for area. People in rural area were 2.1 and 1.7 times more likely attempt to quit and intend to quit than those in urban area, respectively. Conclusion: The GATS Vietnam 2010 showed that the prev

关键词： Cessation Socio-Demographic Factors Global Adult Tobacco Use Survey Vietnam

Preliminary Study on the Magnetic Properties of GeMn Nanocolumn/Ge Multilayers

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Materials Sciences and Applications 2020年第7期11卷 441-449页

作者： thi giang Le Minh Tuan Dau Department of Engineering and Technology Hong Duc University Thanh Hóa Vietnam Interdisciplinary Center of Nanoscience of Marseille (CINaM-CNRS) Aix-Marseille University Campus of Luminy Marseille France

Ge0.94Mn0.06 nanocolumn thin film is a unique phase of GeMn diluted magnetic semiconductors (DMS) which exhibit Curie temperature (TC) > 400 K. The multilayers of Ge0.94Mn0.06 nanocolumns separated by nano-scaled spacers represent great interests for spintronic applications, such as spin valves or giant magneto-resistance (GMR) multilayers. In this article, we present the results obtained from the preliminary study on the exchange coupling in two types of GeMn nanocolumn/Ge multilayers. All the samples have been grown using molecular beam epitaxy (MBE). The superconducting quantum interference device (SQUID) magnetometer has been used to determine the magnetic properties of the samples. In the multilayer system Ge/[Ge0.94Mn0.06(40 nm)/Ge(d nm)]9/Ge0.94Mn0.06(40 nm)/Ge, no exchange coupling can be observed. Inversely, exchange coupling between the layers exists and depends on the thickness of the Ge spacers for the GeMn nanocolumns/Ge multilayer spin valve systems. The exchange coupling in the nanocolumns multilayer systems has been shown to be complex due to the leakage field induced by neighboring nanocolumns and the magnetic anisotropy of nanocolumns.

关键词： Multilayers Ferromagnetic Semiconductor GeMn Nanocolumns Exchange Coupling thin Film

Eye Strain Detection During Online Learning

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Intelligent Automation & Soft Computing 2023年第3期35卷 3517-3530页

作者： Le Quang Thao Duong Duc Cuong Vu Manh Hung Le thanh Vinh Doan Trong Nghia Dinh Ha Hai Nguyen nhan Nhi Faculty of Physics VNU University of ScienceHanoi100000Vietnam University of Science Vietnam National UniversityHanoi100000Vietnam VNU-HUS High School for Gifted StudentsHanoi100000Vietnam Hanoi-Amsterdam High School for the Gifted Hanoi100000Vietnam

The recent outbreak of the coronavirus disease of 2019(Covid-19)has been causing many disruptions among the education systems worldwide,most of them due to the abrupt transition to online *** sudden upsurge in digital electronic devices usage,namely personal computers,laptops,tablets and smart-phones is unprecedented,which leads to a new wave of both mental and physical health problems among students,for example eye-related *** overexpo-sure to electronic devices,extended screen time usage and lack of outdoor sun-light have put a consequential strain on the student’s ophthalmic health because of their young age and a relative lack of responsibility on their own *** to take appropriate external measures to mitigate the negative effects of this pro-cess could lead to common ophthalmic illnesses such as myopia or more serious *** remedy this situation,we propose a software solution that is able to track and capture images of its users’eyes to detect symptoms of eye illnesses while simultaneously giving them warnings and even offering *** meet the requirements of a small and light model that is operable on low-end devices without information loss,we optimized the original MobileNetV2 model with depth-wise separable convolutions by altering the parameters in the last layers with an aim to minimize the resizing of the input image and obtained a new model which we call *** with applying the knowledge distillation tech-nique and ResNet-18 as a teacher model to train the student model,we have suc-cessfully increased the accuracy of the EyeNet model up to 87.16%and support the development of a model compatible with embedded systems with limited computing power,accessible to all students.

关键词： Digital eye strain Covid-19 online study knowledge distillation eye care EyeNet

Synthesis of cation exchange resin-supported iron and magnesium oxides/hydroxides composite for nitrate removal in water

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Chinese Journal of Chemical Engineering 2021年第4期34卷 378-384页

作者： Trung thanh Nguyen Vu Anh Khoa Tran Le Ba Tran Phuoc Toan Phan Minh Tan Nguyen Long giang Bach Surapol Padungthon Cong Khiem Ta Nhat Huy Nguyen Nanomaterial Laboratory An Giang University18 Ung Van Khiem St.Dong Xuyen DistLong Xuyen CityAn Giang ProvinceViet Nam Vietnam National University Ho Chi Minh City Linh Trung WardThu Duc DistrictHo Chi Minh CityViet Nam Faculty of Natural Resources and Environment Ho Chi Minh City University of Technology(HCMUT)268 Ly Thuong Kiet St.Dist.10Ho Chi Minh CityViet Nam Faculty of Engineering-Technology-Environment An Giang University18 Ung Van Khiem StDong Xuyen DistLong Xuyen CityAn Giang ProvinceViet Nam Department of Scientific Research and International Relation Bac Lieu University178 Vo Thi Sau St.Ward 8Bac Lieu CityBac Lieu ProvinceViet Nam NTT Institute of High Technology Nguyen Tat Thanh University298-300A Nguyen Tat ThanhHo Chi Minh CityViet Nam Department of Environmental Engineering Khon Kaen University123 Moo 16 Mittraphap Rd.Nai-MuangMuang DistrictKhon Kaen 40002Thailand

In this study,we reported on the concept and practical use of cation exchange resin(CER)for removing anions in water via pretreating the CER with metal *** cation exchange resinsupported iron and magnesium oxides/hydroxides composite(FeMg/CER)was synthesized and introduced as a new and potential adsorbent for selective removal of nitrate ion in the water *** of FeMg/CER were determined by techniques such as Fouriertransform infrared spectroscopy,scanning electron microscopy,and Xray *** results showed that FeMg/CER material had a high nitrate adsorption capacity of 200 mg NO_(3)^()·g^(1)with a fast equilibrium adsorption time of 30 min at pH *** addition,it had good durability of at least 10 times of regeneration,which could be applied to practical water and wastewater treatment.

关键词： Iron oxide/hydroxide Magnesium oxide/hydroxide Cation exchange resin Adsorption Environment Nanomaterials

Surface PEGylation of hollow mesoporous silica nanoparticles via aminated intermediate

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Progress in Natural Science:Materials International 2019年第6期29卷 612-616页

作者： thi Ngoc Tram Nguyen Diem-Huong Nguyen-Tran Long giang Bach Tran Hoang Du Truong Ngoc Thuy Trang Le Dai Hai Nguyen Tra Vinh University Institute of Applied Materials Science Vietnam Academy of Science and Technology Graduate University of Science and Technology Vietnam Academy of Science and Technology Nguyen Tat thanh University 5. Institute of Research and Development Duy Tan University

A hybrid of organic/inorganic system, hollow mesoporous silica nanoparticles functionalized with poly(ethylene glycol), was synthesized in the presence of coupling agent and aminated ends. Doxorubicin(DOX) was used as a model drug to evaluate the effect of PEGylation on the loading capacity and release pattern of the *** with transmission electron microscopy(TEM) and scanning electron microscopy(SEM), X-ray diffraction(XRD), nitrogen adsorption-desorption, thermogravimetric analysis(TGA) and Fourier transformed infrared(FTIR) confirmed the PEG conjugation, as well as the amorphous mesoporous nature of the synthesized particles. Due to the capping effect of PEG molecules over the pores in the silica structure, the synthesized system was able to retain higher amount of cargo and establish a controlled manner when releasing.

关键词： Hollow mesoporous silica nanoparticles mPEG PEGylation Surface modification

Optimal culture conditions for the generation of natural killer cell-induced dendritic cells for cancer immunotherapy

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Cellular & Molecular Immunology 2012年第1期9卷 45-53页

作者： thanh-nhan Nguyen-Pham Deok-Hwan Yang Truc-Anh thi Nguyen Mi-Seon Lim Cheol Yi Hong Mi-Hyun Kim Hyun Ju Lee Youn-Kyung Lee Duck Cho Soo-Young Bae Jae-Sook Ahn Yeo-Kyeoung Kim Ik-Joo Chung Hyeoung-Joon Kim Je-Jung Lee Research Center for Cancer Immunotherapy Chonnam National University Hwasun HospitalJeollanamdoKorea Department of Hematology-Oncology Chonnam National University Hwasun HospitalJeollanamdoKorea Vaxcell-Bio Therapeutics JeollanamdoKorea The Brain Korea 21 Project Center for Biomedical Human Resources at Chonnam National UniversityGwangjuKorea

Dendritic cell(DC)-based vaccines continue to be considered an attractive tool for cancer *** require an additional signal from the environment or other immune cells to polarize the development of immune responses toward T helper 1(Th1)or Th2 *** play a role in natural killer(NK)cell activation,and NK cells are also able to activate and induce the maturation of *** investigated the types of NK cells that can induce the maturation and enhanced function of DCs and the conditions under which these interactions *** that were activated by resting NK cells in the presence of inflammatory cytokines exhibited increased expression of several costimulatory molecules and an enhanced ability to produce *** cell-stimulated DCs potently induced Th1 polarization and exhibited the ability to generate tumor antigen-specific cytotoxic T lymphocyte *** data demonstrate that functional DCs can be generated by coculturing immature DCs with freshly isolated resting NK cells in the presence of Toll-like receptor agonists and proinflammatory cytokines and that the resulting DCs effectively present antigens to induce tumor-specific T-cell responses,which suggests that these cells may be useful for cancer immunotherapy.

关键词： cancer immunotherapy dendritic cells natural killer cells signal