THE TRITERPENOID AND STEROID FROM THE FRUITING BODY OF Ganoderma applanatum (Pers.) Pat. IN VIETNAM

Five compounds, ergosterol (1), 5α,8α-epidioxy-22E-ergosta-6,22-dien-3β-ol (2); ergosta-7,22-dien-3β-ol (3); lanosta-7,9(11),24-triene-3,26-diol (4) and 3β-hydroxy-5α-lanosta-7,9,24(E)-trien-26-oic acid (5) were isolated from fruiting body of Ganoderma applanatum (Pers.) Pat.  (Ganodermataceae). The structures of the isolated compounds were established by spectroscopic methods (UV, IR, MS, 1H-NMR, 13C-NMR, DEPT, COSY, HSQC and HMBC). These compounds were isolated from the Vietnamese fungi for the first time. Moreover, the lanosta-7,9(11),24-triene-3,26-diol is the first compound was found in the fungi

Strengthen roles of commercial banks in vietnam economy– a case of eximbank

Is it the time for us to evaluate roles of Vietnam commercial banks and importance of risk management activities? This paper uses both quantitative analysis with statistical data and charts, combined with qualitative analysis including synthesis, inductive and explanatory methods in order to estimate and compare market risk via beta CAPM of Eximbank (EIB) and Asia Commercial Bank (ACB), 2 big listed joint stock banks in Vietnam. Research findings show us that market risk of Eximbank is higher and increase during post-low (L) inflation stage, compared to pre-L inflation time. Results may be used for policy implications and research models can be references for other countries including emerging markets

How to Support Poor Vietnamese Consumers to Deal with Food Price Volatility and Food Safety Issues

With 66 per cent of the population living in rural areas, over half depending on farm activities, food security and food safety are now two sides of the government effort to ensure food accessibility for the poor in Vietnam. While people living on low incomes may have to choose cheaper food over safer food, they are now more aware of food safety issues, and need more support to access safe food. After a long time of focusing on increasing food security in terms of quantities, new efforts are now needed to change the practice and awareness of stakeholders to move to quality?oriented production and consumption, including creating reasonable incentives for food producers, socialising of food safety monitoring and improving food safety inspection in Vietnam

Energy-efficient Trajectory Design for UAV-enabled Wireless Communications with Latency Constraints

This paper studies a new energy-efficient unmanned aerial vehicle (UAV)-enabled wireless communications, where the UAV acts as a flying base station (BS) to serve the ground users (GUs) within some predetermined latency limitations, e.g., requested timeout (RT). Our goal is to design the UAV trajectory to minimize the total energy consumption while satisfying the RT requirement from every GU, which is accomplished via two consecutive subproblems: traveling time minimization and energy minimization problems. Firstly, we propose two exhaustive search and heuristic algorithms based on the traveling salesman problem with time window (TSPTW) in order to minimize the UAV’s traveling time without violating the GUs’ RT requirements. While the exhaustive algorithm achieves the best performance at a high computation cost, the heuristic algorithm achieves a trade-off between the performance and complexity. Secondly, we minimize the total energy consumption, for a given trajectory, via a joint optimization of the UAV’s velocity along subsequent hops. Finally, numerical results are presented to demonstrate the effectiveness of our proposed algorithms. In particular, it is shown that the proposed solutions outperform the reference in terms of both energy consumption and outage performance

UAV Relay-Assisted Emergency Communications in IoT Networks: Resource Allocation and Trajectory Optimization

In this paper, a UAV is deployed as a flying base station to collect data from time-constrained IoT devices and then transfer the data to a ground gateway (GW). In general, the latency constraint at IoT users and the limited storage capacity of UAV highly hinder practical applications of UAV-assisted IoT networks. In this paper, full-duplex (FD) technique is adopted at the UAV to overcome these challenges. In addition, half-duplex (HD) scheme for UAV-based relaying is also considered to provide a comparative study between two modes. In this context, we aim at maximizing the number of served IoT devices by jointly optimizing bandwidth and power allocation, as well as the UAV trajectory, while satisfying the requested timeout (RT) requirement of each device and the UAV's limited storage capacity. The formulated optimization problem is troublesome to solve due to its non-convexity and combinatorial nature. Toward appealing applications, we first relax binary variables into continuous values and transform the original problem into a more computationally tractable form. By leveraging inner approximation framework, we derive newly approximated functions for non-convex parts and then develop a simple yet efficient iterative algorithm for its solutions. Next, we attempt to maximize the total throughput subject to the number of served IoT devices. Finally, numerical results show that the proposed algorithms significantly outperform benchmark approaches in terms of the number of served IoT devices and the amount of collected data.Comment: 30 pages, 11 figure

Some properties of the positive boolean dependencies in the database model of block form

The report proposes the concept of positive boolean dependency in the database model of block form, proving equivalent theorem of three derived types, necessary and sufficient criteria of the derived type, the member problem... In addition, some properties related to this concept in the case of block r degenerated into relation are also expressed and demonstrated here

A HOPANE TRITERPENOID FROM THE MYCELIUM OF Isaria japonica IN VIETNAM

A hopane triterpenoid (11b, 22-dihydroxyhopane) was isolated from the methanol extract of the mycelium of Isaria japonica in Vietnam. The structure of this compound was elucidated using a combination of 1D and 2D NMR techniques (1H-, 13C-NMR, COSY, HSQC and HMBC). In the study, we reported the comprehensive 1H- and 13C-NMR spectral data of 11b, 22-dihydroxyhopane for the first time

N-Methyl-N-styrylcinnamamide (lansamide) from Clausena lansium in Vietnam

The title compound, C18H17NO, was isolated from the seeds of Clausena lansium (wampee) (Rutaceae). The X-ray crystal structure analysis confirmed its chemical identity and revealed that it is solvent-free, in contrast to the previously reported monohydrate [Huang, Ou & Tang (2006 ▶). Acta Cryst. E62, o1987–o1988]. The mol­ecular structures are practically identical but the mol­ecules pack differently. In contrast to the monohydrate in which the water molecule generates two hydrogen bonds, no such intermolecular contacts are present in the title compound. The dihedral angle between the cinnamamide and the styryl group is 53.1 (1)°

Study on the effect of processing methods on the total polyphenol, 2,3,5,4’-tetrahydroxystilben-2-O-β-D-glucoside, and physcion contents in Fallopia multiflora Thunb. Haraldson root

This study investigated the changes in the ingredients in Fallopia multiflora Thunb. Haraldson (FMT) root after processing it with different methods such as soaking, stewing, and steaming or combined methods. The total polyphenol, 2,3,5,4′-tetrahydroxystilben-2-O-β-D-glucoside (THSG), and physcion contents in FMT products after processing were determined using high-performance liquid chromatography (HPLC) and ultraviolet-visible (UV-VIS) methods. The results demonstrated that the processing method and time significantly affected the contents of polyphenol, THSG, and physcion. The physcion and total polyphenol content increased or decreased during processing depending upon the processing time, while the THSG content gradually decreased with an increase in the processing time. The content of physcion (a substance that can cause liver toxicity) was analysed, and the suitable conditions for processing of the FMT products were determined as initial soaking in rice swill for 24 h and subsequent stewing with black beans and water for 12 h