Chapter 1 : The impact of modernization on the basic functions of traditional Vietnamese family

2016年度調査研究報告

Structure and physico-chemical properties of silica gels doped with optically activated Er3+ ions by sol-gel process

This paper is devoted  to the study of the relationship between structure and optical properties of silica glasses doped with optically active Er3+ ions and reported the influence of the suitably selected heat treatment on the optical properties of silica glasses. The physico-chemical properties of Er3+doped silica are presented, which has been related with the effects of hydroxyl groups on the luminescence property  of Er3+ in the host matrix of silica

Double RIS-Assisted MIMO Systems Over Spatially Correlated Rician Fading Channels and Finite Scatterers

This paper investigates double RIS-assisted MIMO communication systems over Rician fading channels with finite scatterers, spatial correlation, and the existence of a double-scattering link between the transceiver. First, the statistical information is driven in closed form for the aggregated channels, unveiling various influences of the system and environment on the average channel power gains. Next, we study two active and passive beamforming designs corresponding to two objectives. The first problem maximizes channel capacity by jointly optimizing the active precoding and combining matrices at the transceivers and passive beamforming at the double RISs subject to the transmitting power constraint. In order to tackle the inherently non-convex issue, we propose an efficient alternating optimization algorithm (AO) based on the alternating direction method of multipliers (ADMM). The second problem enhances communication reliability by jointly training the encoder and decoder at the transceivers and the phase shifters at the RISs. Each neural network representing a system entity in an end-to-end learning framework is proposed to minimize the symbol error rate of the detected symbols by controlling the transceiver and the RISs phase shifts. Numerical results verify our analysis and demonstrate the superior improvements of phase shift designs to boost system performance.Comment: 15 pages, 9 figures, accepted by IEEE Transactions on Communication

Influences of the mole ratio SnO2/NaOH on the growth of SnO2 nanorods

SnO2 nanorods have been successfully prepared by hydrothermal method at low temperature. The mole ratio of SnO2/ NaOH plays important role in the morphology and diameter of SnO2 nanorod. Besides, the possible growth mechanisms of SnO2 nanorods are also discussed. Structural properties and surface morphologies of the SnO2 nanorods were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results show that diameters of the nanorods are around 100 nm to 300 nm with lengths of several micrometers. With the success of preparing SnO2 nanorods, which will improve in the research and preparation of gas sensor based on SnO2 materials. Keywords: SnO2, nanorods, hydrothermal method

The effect of polyamine 70000 (BT70) on the zinc plating process in the non-cyanide alkaline plating bath

The effect of polyamine having molecular weight 70,000u (BT70) in the non-cyanide alkaline plating bath on the morphological zinc electrodeposited coating was investigated. The obtained results from the reflectance of electrodeposited zinc coating by a suitable range of electro-current density and SEM images showed that BT70 had effect on the zinc plating in comparison with the zinc deposits from plating bath without BT70. The electrodeposited coating surface was rough and poor adhesion. However, adding BT70 into the plating bath led to the surface roughness of electrodeposited coating and grand size being reduced. Zinc electrodeposited coating from a plating bath containing BT70 at 0.5 g/L, respectively, experienced the highest reflectance, equal 46 % of the electrodeposited coating from the bath containing commercial additives. Hull method showed that the zinc deposited coating surface became smoother with the presence of polyamine in non-cyanide alkaline zinc plating solution. The zinc deposited coating had a semi-gloss scope at 10 A/dm2. If the BT70 content increased, the semi-gloss scop and the gloss of samples’ surfaces also grew up. Keywords. Polyamine, additive, non-cyanide alkaline zinc plating, zinc coating

Electrochemical DNA sensor for label-free soybean transgenic detection

This paper describes the development of electrochemical label- free DNA sensor for detection of transgenic in Round–up Ready Soybean (herbicide tolerance). Two pairs of electrodes which the optimized dimension is 70µm x 30µm (the width of electrode x inter-distance between fingers), were fabricated on a chip for differential measures. The DNA probe (35S 5’-GCT CCT ACA AAT GCC ATC A-3) was designed in such a way that it can hybridize with the CaMV 35S promoter of Roundup Ready soybean. The DNA was immobilized on the surface of the sensor by the mean of (3-aminopropyl)triethoxysilane (APTS) polymer. The response time of DNA sensor is less than 1 second; in case of 100% matching level, the sensitivity is 2 mV/µM. The activity of DNA sensor remains unchanged after 9 months of storage at -4oC in DI water. Some random soybean samples were collected, extracted and tested by the DNA sensor and the results were well matched with the of PCR method

Preoperative magnetic resonance imaging of anal fistulas with scrotal extension: a retrospective study

IntroductionThis study aimed to elucidate the magnetic resonance (MR) characteristics of anal fistulas extending to the scrotum, and the applicable rules, and to correlate MR features with surgical findings.MethodsWe conducted a retrospective study in 150 consecutive patients with anal fistulas extending into the scrotum, who were diagnosed and underwent surgery at University Medical Center Ho Chi Minh City between January 2017 and April 2022. MR findings were evaluated and compared with surgical findings using Cohens kappa coefficient (k) with a 95% confidence interval.Results150 patients (mean age 37.6 ± 10.9 years) with 166 fistulas, including 150 anal fistulas with scrotal extension. Most fistulas were low transsphincteric (80.0%, 120/150 patients). There was a strong agreement for primary tract classification and detecting the location of internal openings between MRI and surgical findings with k = 0.83 (0.780.87) and k = 0.89 (0.85 0.93) (p<0.001), respectively. There is a significant correlation between the location of internal openings and the type of fistula (p<0.05). Low transsphincteric fistulas were predominant in the anterior group (103/122 patients vs. 10/19 patients), while in the posterior group, it was more common in the high transsphincteric fistulas (7/19 patients vs. 14/122 patients), and the intersphincteric fistulas (1/19 patients vs. 5/122 patients); and the suprasphincteric fistulas were only seen in the posterior group (1 patient).ConclusionAnal fistulas with scrotal extension are exceptions to Goodsalls rule. Albeit long-tract fistulas, most are low transsphincteric and have anterior internal openings

LƯỢNG GIÁ KINH TẾ GIÁ TRỊ DU LỊCH TỪ CÁC HỆ SINH THÁI BIỂN VÙNG ĐẢO BẠCH LONG VĨ, HẢI PHÒNG

Bach Long Vi island is an offshore district in the centre of the Gulf of Tonkin in Vietnam and administratively belongs to Hai Phong city. The island surrounded by abundant marine ecosystems with high biodiversity is one of 16 marine protected areas approved by the Prime Minister of Vietnam on 26/5/2010 according to the Decision No.742/QD-TTg. Currently, in addition to the main service of economic activities as fishery logistics, Bach Long Vi island still remains the wild features with beautiful scenery, fresh air and the diversity of marine species that are suitable for the development of eco-tourism and resorts. Although tourism at present is not developed yet, its potentials are promising. Deploying zone travel cost method (ZTCM), tourism potentials based on ecosystem services of Bach Long Vi island were estimated at 5.4 billion VND (Vietnamese currency). The value can be much higher if the infrastructure of the island is improved and the island is accessible more easily. Tourism potential valuation and identification of the advantages of the island strongly support tourism planning in the future.Đảo Bạch Long Vĩ là đảo xa bờ nhất của Việt Nam trong vịnh Bắc Bộ và về mặt hành chính là một huyện đảo trực thuộc thành phố Hải Phòng. Đảo có hệ sinh thái biển bao quanh khá phong phú, đa dạng sinh học cao, là một trong số 16 khu bảo tồn thiên nhiên biển Việt Nam đã được Thủ tướng chính phủ phê duyệt lựa chọn vào ngày 26/5/2010 theo Quyết định số 742/QĐ-TTg. Hiện nay, ngoài hoạt động kinh tế dịch vụ chính là hậu cần nghề cá, huyện đảo Bạch Long Vĩ vẫn giữ nguyên được nét hoang sơ với cảnh quan đẹp, không khí trong lành và sự đa dạng của các loài hải sản thích hợp với phát triển du lịch sinh thái, nghỉ dưỡng. Mặc dù hiện tại du lịch chưa phát triển ở vùng đảo, tuy nhiên tiềm năng du lịch rất lớn. Bằng phương pháp tính chi phí du lịch theo vùng (ZTCM), giá trị tiềm năng du lịch trên nền tảng các dịch vụ hệ sinh thái của đảo Bạch Long Vĩ được ước tính là 5,4 tỷ đồng/năm. Giá trị này còn cao hơn nhiều nếu hạ tầng cơ sở của đảo và khả năng đi lại thuận tiện. Ước tính giá trị tiềm năng du lịch và xác định cụ thể những yếu tố thuận lợi giúp khu vực này phát triển tốt du lịch trong tương lai

Security and Reliability Analysis of Satellite-Terrestrial Multi-Relay Networks with Imperfect CSI

This work investigates the security and reliabil- ity analysis for a novel satellite-terrestrial (SatTer) network. Specifically, a satellite attempts to transmit confidential infor- mation to a ground user (GU) via the support of multiple relay nodes in the presence of an eavesdropper that tries to overhear the information. A friendly jammer is deployed to improve the secure transmission between the satellite and the relays. Furthermore, satellite-to-relay generalized Rician fading channels and imperfect channel state information (CSI) are deployed to examine a general system model. In this context, the closed-formed expressions for the outage probability (OP) and intercept probability (IP) are derived corresponding to an amplify-and-forward (AF)-based relaying scheme, which is challenging and has not been studied before. Finally, the exactness of the mathematical analyses is validated through Monte Carlo simulations. Furthermore, the effects of various key parameters (e.g., channel estimation errors, satellite’s transmit power, relay’s transmit power, number of relays, and fading severity parameter) are examine

A Phase 2/3 double blinded, randomized, placebo-controlled study in healthy adult participants in Vietnam to examine the safety and immunogenicity of an inactivated whole virion, alum adjuvanted, A(H5N1) influenza vaccine (IVACFLU-A/H5N1)

Abstract Background A global shortfall of vaccines for avian influenza A(H5N1) would occur, especially in low- and-middle income countries, if a pandemic were to occur. To address this issue, development of a pre-pandemic influenza vaccine was initiated in 2012, leveraging a recently established influenza vaccine manufacturing capacity in Vietnam. Methods This was a Phase 2/3, double-blinded, randomized, placebo-controlled study to test the safety and immunogenicity of IVACFLU-A/H5N1 vaccine in healthy adults. Phase 2 was a dose selection study, in which 300 participants were randomized to one of the three groups (15 mcg, 30 mcg, or placebo). Safety and immunogenicity were assessed in all participants. In Phase 3, 630 participants were randomized to receive the IVACFLU-A/H5N1 vaccine dose selected in Phase 2 (15 mcg, n = 525) or placebo (n = 105). Safety was assessed in all Phase 3 participants and immunogenicity was measured in a subset of participants. Results The vaccine was well tolerated and most of the adverse events were mild and of short duration. Mild pain at the injection site was the most common adverse event seen in 60 percent of participants in the vaccine group in Phase 3. In Phase 2, both 15 mcg and 30 mcg doses were immunogenic, so the lower dose was selected for further testing in Phase 3. In Phase 3 overall seroconversion rates were 68 percent for hemagglutination inhibition (HI), 51 percent for microneutralization (MN) and 56 percent for single radial hemolysis (SRH). The seroprotection rates were 44 percent for HI, 41 percent for MN and 55 percent for SRH. The GMT ratio was 5.31 and 3.7 for HI and MN respectively; GMA was 4.75 for the SRH. Conclusion The IVACFLU A/H5N1 was safe and immunogenic. Development of this pandemic avian influenza vaccine is a welcome addition to the limited global pool of these vaccines. ClinicalTrials.gov register NCT02612909