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Introduction: Tenofovir alafenamide (TAF), a prodrug of tenofovir (TFV), is currently used for treatment of chronic hepatitis B as first line recommendation. The Vietnamese market is currently circulating a tenofovir alafenamide generic. This formulation has not been assessed for in vivo bioequivalence. This study has been performed with the aim of development, validation, and application of LC-MS/MS procedure for quantitation of TAF and TFV in human plasma. Methods: Internal standard (IS), and analytical parameters were investigated to find out the suitable IS and conditions. Chromatographic conditions were optimized by considering the column type, mobile phase component, concentration of the buffer solutions and strength, oven temperature, flow rate, and injection volume. Human plasma samples were treated by protein precipitation with acetonitrile. The assay was validated in compliance with US-FDA and EMA guidelines. This assay was applied to evaluate the bioequivalence of the generic and reference products of 25 mg TAF in the healthy Vietnamese subjects under fed conditions. Results: TAF, TFV, IS were ionized using ESI and detected by MRM mode to obtain molecular and fragment ions for quantification. The recovery of all analytes from human plasma was above 70%. The chromatographic conditions contained a C6-Phenyl column and mobile phase including acetonitrile and 0.5% formic acid. The specificity, precision, accuracy, matrix effect of all the analytes were in the acceptable range. Thirty six subjects finished the fed trial. The two products’ geometric mean ratios for AUC0-t, AUC0-∞, and Cmax (80.00% to 125.00%) met the bioequivalence acceptance criteria. Conclusions: A LC-MS/MS procedure for simultaneous quantitation of TAF and TFV in human plasma was developed, validated, applied.

Introduction: Several generic products containing simvastatin are circulating on the Vietnamese market at a more inexpensive price than that of a brand-name one. These formulations, however, have not been assessed for in vivo bioequivalence to the reference product. After oral administration, simvastatin (SIM) is extensively converted into an active metabolite, beta-hydroxy simvastatin acid (SIM-A) and a very low concentration of simvastatin can be found in plasma. Therefore, a method for quantification of simvastatin and its metabolite needs to be developed with a high specificity and sensitivity to detect these analytes in human plasma at such low concentrations. Our purpose was to develop a reliable LC-MS/MS (liquid chromatography-tandem mass spectrometry) method for simultaneous determination of simvastatin and metabolite of simvastatin, beta-hydroxy simvastatin acid, in human plasma and to apply this method to evaluate the bioequivalence of a test product in comparison with the reference product. Methods: Mass spectrometry, internal standard (IS), and chromatographic conditions were investigated to find out the suitable IS and conditions. Human plasma samples were treated by liquid-liquid extraction (LLE). The assay was validated in compliance with US-FDA (United States-Food and Drug Administration), and EMA (European Medicines Agency) guidelines. Results: LC-MS/MS with electrospray ionization interface in positive (for SIM and lovastatin as IS) and negative (for SIM-A) ionization mode performed under the multiple reaction monitoring mode was used for detection of the analytes. The transition of m/z is 436.00 → 285.15, 435.10 → 319.15, and 404.95 → 199.10 for SIM, SIM-A, and IS, respectively. Tert-buthyl methyl ether was used for extraction of analytes from human plasma by a simple LLE followed by addition of an ammonium acetate buffer. The developed method was fully validated with acceptable selectivity, linearity and linear range, matrix effect, lower limit of quantitation (LLOQ), carryover, dilution integrity, and intra- and inter-day accuracy and precision, free-thaw stability. Conclusions: The method can be applied for quantification of these compounds in human plasma for in vivo bioavailability and bioequivalence studies.

In this paper, the cavitation process on a grain boundary in polycrystalline Alloy 247 is simulated and modelled. The cavitation process includes mechanisms such as nucleation, growth and coalescence of creep pores and was used for characterization of polycrystalline Alloy 247 in terms of creep damage and especially creep pore sizes. Two main parameters were defined that are either responsible for pore nucleation or pore growth and that are calculated from simulation variables and material coefficients. Therefore, a Design of Experiment (DOE) was carried out to identify the effect of each material coefficient and simulation variable on the cavitation process as well as the ranges of the main parameters for pore nucleation and pore growth. As a result of the investigation, a series of Monte Carlo simulations was run with designated combinations of main parameters within the identified range. The simulation results were used as training and test data to create a model by machine learning methods. Different machine learning methods such as neural network, random forest tree and k-nearest neighbor were applied and compared to determine the best fitted model. Based on metallographic images, a first calibration of the model’s parameters has also been carried out. The resulting machine learning model allows the prediction of creep pore sizes in the grain boundary of Alloy 247 for any given temperature and stress.

This paper proposes a GAN-based denoising and super-resolution network for stereo images. The proposed network solves the two problems separately in an end-to-end training fashion. A matchability attention module are introduced to compute matching cost spaces and provide the stereo information between generated stereo images. In addition, the correlation loss is proposed to preserve the correspondence between a stereo pair. We evaluate the proposed network using the KITTI 2012 and KITTI 2015 datasets. In addition, we compare with state-of-the-art denoising and super-resolution methods. Experimental results show that the proposed method significantly outperforms the existing method both in terms of qualitative and quantitative analysis.

Minimizing distortion produced by embedding process is very important to improve the security of hidden message and maintain the high visual quality of stego images. To achieve these objectives, an effective strategy is to perform pixel selection which is well-known as a channel selection rule. In this approach, a pixel associated with the smallest image degradation is chosen to carry secret bits. From these facts, in this paper, a new secure channel selection rule for digital images in spatial domain is designed and proposed. In this new approach, the modified matrix embedding method is utilized as data hiding method because it introduces more than one embedding change to be performed. This enables us to select a suitable pixel to embed message bits with less degradation yielded in a stego-image. In pixel selection of the proposed method, a just noticeable difference value and gradient value of a considering pixel are employed together. The experimental results (which were conducted on 10,000 uncompressed images) indicate that stego images of the proposed approach achieve a higher perceptual quality and security than those of the stego-images created by the previous approaches.

The paper discusses on the effect that the growth in our energy consumption as a species is having upon the planet, and how the global lighting and telecommunications industries are major contributors. We demonstrate that through the adoption of LED based lighting combined with visible light communications, substantial economical and power savings by orders of magnitude can be made over existing technologies, contributing towards a greener more sustainable future. The future of LED technology is also discussed with a focus on organic technology, promising increased savings.

Agriculture is an important economic aspect of many Asian countries, including Vietnam. One major obstacle, which prevents Vietnam from exporting some fruit species to western countries such as mangoes, is the irregular quality of the harvested fruits. Various research aimed to solve this problem by proposing different methods of estimating the weights of the fruits to determine anomalies. However, most methods are only tested for their maximum accuracy under favorable conditions with expensive equipments, and are therefore often not suitable for the poor farming regions of the developing countries. In this paper, with the main focus being mangoes, we would like to study a simpler approach using a combination of images processing techniques and support vector machine (SVM) for determining the approximate weight range of the fruits. The target device, on which the approach will be tested, is a Raspberry Pi 3B, which is fairly affordable even in developing countries. This will examine the feasibility of the weight classification for agriculture using only cheap hardware.

In the food industry, most fruit species are D bounding box of the mangoes and the Monte Carlo evaluated based on many qualifications, among which weight is Integration [5] to calculate the approximation of a solid one. Various methods and approaches to weight estimation object whose surface area is known [6]. have been done using both 2-D and 3-D image analysis Fig. 2. The principal axes of bounding box [2] techniques. In Vietnam, the application of these approaches will bring tremendous benefits to the agriculture industry by automating the sorting process for exporting fruit to foreign countries. This paper will present an analysis of the performance contributions of the different geometric parameters to the weight estimation process, with the target fruit being Hoa Loc mango.

This study presents a multi-residue method for simultaneous qualitative and quantitative analysis of eight antibiotics from some common classes, including beta-lactam, tetracyclines, lincosamides, glycopeptides, and sulfonamides in 39 aquaculture and river water samples from the Mekong Delta (Vietnam) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). As a result, doxycycline (DXC), oxytetracycline (OTC), lincomycin (LCM), sulfamethoxazole (SMX), and sulfamethazine (SMZ) were detected with high frequency over 65% and an average concentration of 22.6&ndash, 76.8 ng&middot, mL&minus, 1. The result suggests that antibiotic residues in the aquaculture and river waters are considered as an emerging environmental problem of the region. To address this issue, we fabricated the well-defined TiO2 nanotube arrays (TNAs) and nanowires on nanotube arrays (TNWs/TNAs) using the anodization method. The TNAs had an inner tube diameter of ~95 nm and a wall thickness of ~25 nm. Meanwhile, the TNWs/TNAs had a layer of TiO2 nanowires with a length of ~6 &micro, m partially covering the TNAs. In addition, both TNAs and TNWs/TNAs had pure anatase phase TiO2 with (101) and (112) dominant preferred orientations. Moreover, the TNAs and TNWs/TNAs effectively and rapidly degraded the antibiotic residues under UV-VIS irradiation at 120 mW/cm2 and obtained over 95% removal at 20 min. Indeed, the photocatalytic reaction rate constants (k) were in the range of 0.14&ndash, 0.36 min&minus, 1 for TNAs, and 0.15&ndash, 0.38 min&minus, 1 for TNWs/TNAs. Noticeably, the k values of TNWs/TNAs were slightly higher than those of TNAs for LCM, DXC, OTC, SMZ, and SMX that could be attributed to the larger surface area of TNWs/TNAs than TNAs when TNWs/TNAs had an additional ~6&mu, m TNWs top layer.

Embedding a secret message into the pixels of a cover image yields a visual distortion if these pixels belong to smooth regions. Thus, this prompted the development of some edge-based approaches in which only the edge pixels are used to hide secret bits. As a result, the visual quality of stego images is improved. However, the capacity is limited due to some unused regions in cover images. In this paper, an adaptive multi bit-planes image steganography using block data-hiding (MPBDH) is proposed. This method employs more than one bit-plane and applies an adaptive complexity threshold computation to select the complex regions of a cover image used in data hiding. Consequently, the embedding capacity and security performance are significantly improved in comparison with previous approaches based on pixel and block complexity. The results, which are obtained from experiments performed on 10,000 natural gray-images, indicate that the embedding capacity and security introduced in the proposed approach overcome the problems of previous approaches. The proposed approach is hence suitable for secure communications.

The computational complexity of matrix embedding (ME)-based steganography is high due to the use of the Hamming parity check matrix and matrix multiplication. Furthermore, with only one embedding change solution, ME cannot minimize embedding distortions when applied to joint photographic experts group (JPEG) steganography. In this paper, we propose a novel block data-hiding (BDH) algorithm to improve the performance of JPEG steganography. BDH allows a byte of data to be hidden in a binary block by modifying a maximum of two bits of the binary block must be changed. Moreover, BDH can be applied to the new channel selection rule for JPEG steganography with more available embedding solutions and less computational complexity than modified matrix embedding (MME). In addition, to increase the security of hidden data against extraction attacks, the secret message is encrypted by a cipher based on cellular automata (CA). The bitwise XOR operator is employed in the encryption process to maintain speed and security when a non-repeating key stream is used. The experimental results indicate that the proposed approach has a high anti-detection property against ensemble classifiers (universal steganalyzers), high security against recovery attacks, and good perceptual quality.

Lotus leaves are a popular remedy in Asia to treat obesity, insomnia and mental impairment; alkaloids are considered most relevant for bioactivity. In this study the first CE method for the determination of all major alkaloids ((-)-nuciferine, (-)-nornuciferine, (-)-caaverine, (-)-armepavine, (+)-norarmepavine, (+)-isoliensinine and (+)-pronuciferine) in Nelumbo nucifera leaves was developed. The optimum buffer showed to be a solution of 100mM ammonium acetate in a mixture of methanol, acetonitrile and water, also containing 0.6% acid acetic. Applied voltage, temperature and detection wavelength were 25kV, 30°C and 225nm; the required analysis time was 15min. By CE-MS all standard compounds could be assigned in positive ESI mode, and two minor alkaloids were tentatively identified (n-nornuciferine and roemerine). A mixture of water, methanol and acetic acid served as sheath liquid in these experiments. The NACE assay was fully validated and utilized to analyze Lotus leaf samples collected in different parts of Vietnam. Respective results revealed significant qualitative and quantitative differences depending on growing area and season. Yet, in all samples (-)-nuciferine (0.34-0.63%), (-)-armepavine (0.13-0.20%), and (+)-isoliensinine (0.06-0.19%) were the most dominant alkaloids. The total alkaloid content varied from 0.72 to 1.41%.

The exact closed-form expressions for outage probability and bit error rate of spectrum sharing-based multi-hop decodeand- forward (DF) relay networks in non-identical Rayleigh fading channels are derived. We also provide the approximate closed-form expression for the system ergodic capacity. Utilizing these tractable analytical formulas, we can study the impact of key network parameters on the performance of cognitivemulti-hop relay networks under interference constraints. Using a linear network model, we derive an optimum relay position scheme by numerically solving an optimization problem of balancing average signal-to-noise ratio (SNR) of each hop. The numerical results show that the optimal scheme leads to SNR performance gains of more than 1 dB. All the analytical expressions are verified by Monte-Carlo simulations confirming the advantage ofmultihop DF relaying networks in cognitive environments., 11 pages, 8 figures, accepted on "Journal of Communications and Networks"

In the context of wireless sensor networks (WSN), a design of an energy efficient wireless data collecting network and a low power water level monitoring station have been proposed in this paper. Different low power consumption sub-Ghz wireless modules have been compared in this paper, and a most efficient wireless module have been selected in order to design a wireless sensor network. This power efficient wireless sensor network have been designed to connect to many water level monitoring stations and transmit its data to a remote centre. In order to ensure a longterm operation in environment without the grid power supply, solar power supply have been selected and a low power consumption design of a water level monitoring station is also proposed. Finally, the power consumption of the proposed station with wireless sensor network module has been calculated to prove the energy efficiency. With the advantage of a low power consumption and low cost design, the proposed wireless sensor network and water level monitoring station can be applied widely in urban environment in developing countries like Vietnam.

The traditional use of lotus leaves as an anti-inflammatory remedy is associated with the occurrence of phenolic compounds. In this study the first CE method for the analysis of all major phenolic constituents in Nelumbo nucifera leaves is presented. It permits the separation of nine relevant markers in less than 10 min. The optimized procedure was fully validated and then used to analyze diverse samples collected in Vietnam. They revealed significant qualitative and quantitative differences depending on growing area and season. Yet, in all of them, quercetin-3-O-β-D-glucuronide, hyperoside, and isoquercitrin were the most dominant flavonoids.

In a context of wireless smart grid network for building or user household, smart grid device hardware and wireless smart grid network are investigated in this paper. In this smart grid home network, a Smart Grid Home Gateway node can receive a billing information or data from Smart Grid center, and then control the End-device Controlling node to reduce the electricity consumption or minimize the consumption cost. Hardware analysis and design of a Smart Grid Home Gateway and End-device Controlling node are proposed with a goal of low cost and efficient energy consumption. Some low cost wireless transceiver for Smart Grid are investigated and a simple wireless network topology based on star routing protocol for Smart Grid Home Network are also proposed. Through a practical test and received signal strength measurement in an indoor environment, the reliability of data communications of this smart grid home network has been proved.

This paper presents a low power consumption and low cost automatic data collection network for water meter application. Based on transmission performance and power consumption, several low cost sub-GHz wireless transceivers are analyzed and compared, and consequently a suitable hardware is chosen. The associated network protocol stack is also examined. To construct the automatic collecting data mechanism, we consider a cluster based wireless sensor network (WSN) where routers and a GPRS gateway are used to link each cluster to a data collection center. Advantages of this proposed configuration are the simple implementation, low cost and low power consumption. By using the Monte Carlo simulation technique, packet delivery ratio and power consumption for different topologies are investigated. Based on obtained results, the optimum network topology for automatic water meter reading in a typical urban environment is finally proposed.

Poly(d,l-lactic-co-glycolic acid) (PLGA) nanoparticles with negative surface charge were reversed to positive by cationic surfactant-DDAB before being coated with an anionic polymer, hyaluronic acid, to improve their site-specific intracellular delivery against CD44 receptor overexpressing cancer cells. Incorporating artesunate (ART)—a promising anticancer drug into PLGA/HA nanoparticles, is expected not only to overcome its poor aqueous solubility and stability but also enhance the activities. The obtained particles were characterized by dynamic light scattering, zeta potential measurements, and transmission electron microscopy (TEM). Cancer cell internalization of the NPs was evaluated by flow cytometry and cytotoxicity of the NPs was tested by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay. PLGA/HA nanoparticles showed greater extent of cellular uptake to SCC-7 and MCF-7 cells, indicating their affinity with CD44 receptor-mediated endocytosis. Almost 60 % of ART was released into the outer media after 48 h. In vitro fluorescence sorting demonstrated that PLGA/HA had highly efficient targeting and accumulation into CD44 receptor overexpression cells. The significant reduction in cell viability as well as greater induction of apoptosis suggested a potential in anticancer therapy of ART loaded PLGA/HA.

This paper presents a wireless Smart Grid network for high-rise apartment building application. In order to construct Smart Grid network for building, a cluster based wireless network where Coordinator collects electricity usage information from end-nodes of its cluster. GPRS/3G gateway is used to link each cluster to Remote center. This configuration can deploy all services of Smart Grid application, advantages of this network are simple implementation, low cost and low consumption. Several low cost and low consumption wireless sub-GHz transceivers are studied in this paper, consequently an appropriate wireless hardware is chosen and a design of Smart Grid home gateway is presented. The cluster size of network is evaluated by a good transmission performance and latency based on NS-2 (network simulation 2) tool. Following obtained results, an optimum Smart Grid network for high-rise apartment building is finally proposed.

This paper presents a hardware design of smart grid home gateway that integrates smart home network to be compatible for smart grid integration. In this network, a Smart Grid Home Gateway can control the electrical appliances based on the programming schedule or data received from control center. Moreover, some low cost wireless transceivers for Smart Grid are investigated and a simple wireless network topology based on star routing protocol for Smart Grid Home Network is also proposed. Final, demonstration results display an actual SGHG prototype to verify the system.