Bidding Strategies in Agent-Based Continuous Double Auctions

http://repository.vnu.edu.vn/handle/VNU_123/26782

Biologically-Inspired Collaborative Computing

	http://repository.vnu.edu.vn/handle/VNU_123/26836

Bioinformatics Research and Development

http://repository.vnu.edu.vn/handle/VNU_123/26810

Network and Parallel Computing

http://repository.vnu.edu.vn/handle/VNU_123/27278

Natural Computing

http://repository.vnu.edu.vn/handle/VNU_123/27261

Chiến lược giá cả và chất lượng sản phẩm nhằm tăng trưởng xuất khẩu thủy sản Việt Nam vào thị trường Nhật Bản : Luận văn ThS. Quản trị Kinh doanh : 60 34 05

http://repository.vnu.edu.vn/handle/VNU_123/47420

Một số biên pháp để tăng cường hoạt động tiêu thụ sản phẩm của Công ty cổ phần Bia Sài Gòn Hà Nội giai đoạn 2014 -2019 : Luận văn ThS. Quản trị kinh doanh : 60 34 05

http://repository.vnu.edu.vn/handle/VNU_123/47418

Hoàn thiện công tác tạo động lực cho lực lượng bán hàng tại Công ty TNHH Thương mại FPT : Luận văn ThS. Quản trị Kinh doanh : 60 34 05

http://repository.vnu.edu.vn/handle/VNU_123/47424

Giải pháp Marketing nhằm thu hút đầu tư vào khu công nghiệp của công ty TNHH VSIP Hải Phòng : Luận văn ThS. Quản trị Kinh doanh : 60 34 05

http://repository.vnu.edu.vn/handle/VNU_123/47422

Hoàn thiện chính sách đãi ngộ nhân lực tại chi nhánh Giải Phóng – Công ty cổ phần ô tô Trường Hải : Luận văn ThS. Quản trị kinh doanh : 60 34 05

http://repository.vnu.edu.vn/handle/VNU_123/47425

The optical properties and energy transition process in nanocomposite of polyvinyl-pyrrolidone polymer and Mn-doped ZnS

This study has been carried out on the optical properties of polyvinyl-pyrrolidone (PVP), the energy transition process in nanocomposite of PVP capped ZnS:Mn nanocrys-talline and the influence of the PVP concentration on the optical properties of the PVP capped ZnS:Mn nanocrystalline thin films synthesized by the wet chemical method. The microstructures of the samples were investigated by X-ray diffraction, the atomic absorption spectroscopy, and transmission electron microscopy. The results showed that the prepared samples belonged to the sphalerite structure with the average particle size of about 2–3 nm. The optical properties of samples are studied by measuring absorption, photoluminescence (PL) spectra and time-resolved PL spectra in the wavelength range from 200 to 700 nm at 300 K. From data of the absorption spectra, the absorption edge of PVP polymer was found about of 230 nm. The absorption edge of PVP capped ZnS:Mn nanoparticles shifted from 322 to 305 nm when the PVP concentration increases. The luminescence spectra of PVP showed a blue emission with peak maximum at 394 nm. The luminescence spectra of ZnS:Mn–PVP exhibits a blue emission with peak maximum at 437 nm and an orange–yellow emission of ion Mn 2+ with peak maximum at 600 nm. While the PVP coating did not affect the micro-structure of ZnS:Mn nanomaterial, the PL spectra of the PVP capped ZnS:Mn samples were found to be affected strongly by the PVP concentration

 http://link.springer.com/article/10.1007/s11082-012-9611-y
http://repository.vnu.edu.vn/handle/VNU_123/32892

The Tongking Gulf through History

http://www.upenn.edu/pennpress/book/14844.html
http://repository.vnu.edu.vn/handle/VNU_123/32894

SUPERCHARACTERS AND PATTERN SUBGROUPS IN THE UPPER TRIANGULAR GROUPS

Abstract LetUn(q) denote the upper triangular group of degree nover the finite field Fq withq elements. It is known that irreducible constituents of supercharacters partition the set of all irreducible characters Irr(Un(q)). In this paper we present a correspondence between supercharacters and pattern subgroups of the formUk(q)∩wUk(q), wherewis a monomial matrix in GLk(q) for somek<n

http://link.springer.com/article/10.1007/s10801-011-0293-5
http://repository.vnu.edu.vn/handle/VNU_123/32926

Stereocomplexation of low molecular weight poly(L-lactic acid) and high molecular weight poly(D-lactic acid), radiation crosslinking PLLA/PDLA stereocomplexes and their characterization

Poly(L-lactic acid)s (PLLAx) were synthesized from L-lactic acid by polycondensation. Different stereocomplexes were also obtained with equimolar mixtures of synthesized PLLAx and a commercial PDLA. The stereocomplexes were crosslinked with triallyl isocyanurate (TAIC) by gamma irradiation. Crosslinking density increased with radiation doses, the heavier the crosslinking network, the lower its swelling degree. The crosslinking structures were introduced in the stereocomplexes inhibiting the mobility for crystallization of PLLA molecules. Thermal and mechanical properties of PLA stereocom-plexes were remarkably enhanced by radiation induced crosslinking. PLA stereocomplex does not seem to be degraded by PLLA degrading microorganisms existing in compost at room temperature, but the synthesized PLLA was significantly degraded

 http://repository.vnu.edu.vn/handle/VNU_123/32928

Charge transfer at organic-inorganic interface of surface-activated PbS by DFT method

Electronic structure of a surface-activated PbS by a bio-active molecule 4-aminothiophenol (4-ATP) was in-vestigated using density functional theory (DFT). The obtained results demonstrated the importance of charge transfer which accounted for theflipping of surface rumpling and the nature of the binding between the activated surface and the capping agent. The influence of 4-ATP–PbS topology on bonding nature between surface atoms was discussed. The capping-induced bonding nature shift was interpreted as surface core level shifts (SCLSs) of PbS.

 http://www.sciencedirect.com/science/article/pii/S0039602812003445
http://repository.vnu.edu.vn/handle/VNU_123/32941

Ultimate Displacement of Reinforced Concrete Columns with Light Transverse Reinforcement

This article presents the analytical and experimental investigations carried out on reinforced con-crete (RC) columns with light transverse reinforcement. A semi-empirical model is developed to estimate the ultimate displacement (displacement at axial failure) of RC columns with light transverse reinforcement subjected to simulated seismic loading. The developed model is calibrated using the collected data of RC columns tested to the point of axial failure. A series of experiments is conducted on five RC columns with light transverse reinforcement to validate the applicability and accuracy of the developed model. It is concluded from the study that the mean ratios of the experimental to predicted ultimate displacement and its coefficient of variation are 1.077 and 0.194, respectively, showing a good correlation between the developed model and the experimental data

http://www.tandfonline.com/doi/abs/10.1080/13632469.2012.730117 http://repository.vnu.edu.vn/handle/VNU_123/32945

Fast pyrolysis of palm kernel cake using a fluidized bed reactor: Design of experiment and characteristics of bio-oil

http://www.sciencedirect.com/science/article/pii/S1226086X12002390 http://repository.vnu.edu.vn/handle/VNU_123/32975 In this study, the central composite rotatable design (CCRD) was employed to investigate the effects of the feedstock feed rate, biomass particle size, pyrolysis temperature, and residence time on the fast pyrolysis of palm kernel cake. A mathematical model for the liquid product yield was developed and applied to obtain a maximum yield of 49.5 wt%. The GC–MS analyses of the bio-oils at the two different temperatures of 400 and 500 8C showed that they were a complex mixture composed of mostly oxygenated compounds including b-D-allose, derivatives of furan and phenol, and a considerable amount of fatty acids

The finite Hartley new convolutions and solvability of the integral equations with Toeplitz plus Hankel kernels

The main aim of this work is to consider integral equations of convolution type with the Toeplitz plus Hankel kernels firstly posed by Tsitsiklis and Levy (1981) [11]. By constructing eight new generalized convolutions for the finite Hartley transforms we obtain a necessary and sufficient condition for the solvability and unique explicit L 2 -solution of those equations. Thanks to this convolution approach the solvability conditionobtainedhere is remarkablydifferent fromthose inTsitsiklis andLevy (1981) [11] and in other papers

 http://www.sciencedirect.com/science/article/pii/S0022247X1200604X
http://repository.vnu.edu.vn/handle/VNU_123/32979

Investigation of polyethylene oxide-based prolonged release solid dispersion containing isradipine

The aim of the study was to press a synergistic act of a formulation: (1) enhancing the dissolution rate of a poorly water-soluble drug; (2) controlling the release rate of the drug. There is still little published research on such a formulation. The model drug used in the current study is isradipine (IS), a calcium channel blocker of the dihydropyridine class. To fulfill the expected target, solid dispersion containing IS was first prepared with the carrier polyethylene glycol 6000 (PEG 6000) with the melting method and then polyethylene oxide N-60K (PEO N-60K) was utilized to induce drug release in a controlled manner. Physicochemical properties of the solid dispersion and physical mixture were character-ized by powder x-ray diffraction (PXRD) and Fourier transform infrared (FTIR) spectroscopy to investigate the structural behavior of drug and IS-PEG interactions, respectively. Preparation of such a formulation not only enhanced but also controlled the drug dissolution rate in both simulated gastric (pH 1.2) and intestinal (pH 6.8) media. This result should be a consideration for pharmaceutical scientists in maintaining the desired blood levels of drugs with narrow therapeutic fluctuation ranges for extended periods of time after a single administration.

http://www.sciencedirect.com/science/article/pii/S1773224713500402 http://repository.vnu.edu.vn/handle/VNU_123/32982

ON FOUR-VARIABLE EXPANDERS IN FINITE FIELDS

Letf : F l q →Fq be a given function. We say thatf is a moderate expanderif there exists an >0 such that for|A| q 1− one has that|f(A,.. .,A)| q. We show that x1x2+(x3−x4) 2 , f(x1)+g(x2)+x3x4, f(x1)+g(x2)+ (x3−x4) 2 , f(x1)g(x2)+x3x4,and f(x1)g(x2)+ (x3−x4) 2 are moderate expanders with the threshold =3/8 for various polynomials f, g∈Fq[x]

 http://epubs.siam.org/doi/abs/10.1137/120892015
http://repository.vnu.edu.vn/handle/VNU_123/32986

STABILITY AND ROBUST STABILITY OF LINEAR TIME-INVARIANT DELAY DIFFERENTIAL-ALGEBRAIC EQUATIONS

Necessary and sufficient conditions for exponential stability of linear time-invariant delay differential-algebraic equations are presented. The robustness of this property is studied when the equation is subjected to structured perturbations and a computable formula for the structured stability radius is derived. The results are illustrated by several example

 http://epubs.siam.org/doi/abs/10.1137/130926110
http://repository.vnu.edu.vn/handle/VNU_123/32988

Design of photocontrolled biomolecules based on azobenzene derivatives

This review focuses on methods of designing photocontrolled proteins and nucleic acids. Data on prep-aration and modification of proteins and nucleic acids with azobenzene derivatives are summarized. Examples of using photoswitchable proteins, their substrates, inhibitors and ligands containing azobenzene, as well as azobenzene deriv-atives of nucleic acids, for design of nanomachines are considered. The bibliography includes 122 references

http://iopscience.iop.org/article/10.1070/RC2013v082n10ABEH004355/meta http://repository.vnu.edu.vn/handle/VNU_123/32990

Vectored DSL: Potential, Implementation Issues and Challenges

This paper investigates specific techniques suitable for Vectored DSL, their performance, complexity and practical implementation. More specifically, various Vectored DSL tech-niques for both upstream and downstream transmission are discussed, including the Tomlinson-Harashima Pre-coder (THP), Diagonalizing Pre-coder (DP), Zero-Forcing (ZF) canceller, and Decision-Feedback (DF) canceller. A thorough discussion on some of the practical implementation aspects of Vectored DSL is provided. In particular, various implementation challenges are discussed, including computational load, memory storage, line management, partial crosstalk cancellation, and the effect of imperfect channel knowledge. As well, the potential gains and challenges of combining Phantom DSL and Vectored DSL are also discussed. Illustrative examples are provided based on both measured data and channel models to compare the various Vectored DSL techniques and their practical implementation challenges.

 http://ieeexplore.ieee.org/document/6422286/
http://repository.vnu.edu.vn/handle/VNU_123/32991

Treatment of tapioca starch wastewater by a novel combination of physical and biological processes

A pilot plant combining dissolved airflotation, anaerobic degradation in an expanded granular sludge bed (EGSB) reactor and aerobic post-treatment in a verticalflow constructed wetland has been used to treat tapioca starch wastewater for more than 2.25 years. It is demonstrated that organic matter (chemical oxygen demand by>98%), nitrogen (Kjeldahl-N by>90%) and cyanide (total cyanide by>99%) can be removed very efficiently under stable operating conditions. The removal efficiency for phosphorus is lower (total-P by 50%). The treatment concept, which includes several sustainable aspects, e.g. production of energy to be used on-site, low operation demands and minimal use of chemicals, could be interesting for small- and middle-sized tapioca processing plants

https://www.ncbi.nlm.nih.gov/pubmed/24056422
http://repository.vnu.edu.vn/handle/VNU_123/32995

First-principles modeling of C-60-Cr-graphene nanostructures for supporting metal clusters

We present a first-principles modeling study of a new class of nanomaterials in which buckminsterfullerene (C 60 ) and graphene (G) are bridged by Cr via coordination bonds. Two nanostructures denoted as G(C 54 )–Cr–C60 and G(C150 )–Cr–C 60 are investigated, which share many similarities in the configuration geometries but differ in the distribution densities of Cr–C 60 on the graphene surface. The binding energies between C 60 and the rest of the system in these complexes are 10 calculated to be 2.59 and 2.10 eV, respectively, indicative of their good structural stability. Additional spin-polarized calculations indicate that G(C54 )–Cr–C 60 is weakly ferromagnetic, which is chiefly due to the contribution from the 3dshell of Cr. We then investigate three model complexes of C 60 –Cr–G(C 54 ) and a metal cluster (Ni4 , Pd 4 , or Pt 4 ). The binding energies of these three nanostructures are significantly large (3.57, 2.38, and 4.35 eV, respectively). Electron density analysis along the Ni–C, Pd–C, and Pt–C 15 bonds consistently affirms that the Pt–C bond is the strongest while the Pd–C bond is the weakest. The strong Pt–C bond is attributed to the effective overlap of 2 5 z d (Pt) and 2p z (C) orbitals. Partial density of states analysis indicates that Ni4 and Pd4 substantially contribute to the strong ferromagnetism of the complexes, whereas Pt4 is observed to be non-magnetic even when the spin-orbit coupling is taken into account. H2 dissociation relatively low (0.76 eV

 http://pubs.rsc.org/en/Content/ArticleLanding/2013/CP/c3cp53529k#!divAbstract
http://repository.vnu.edu.vn/handle/VNU_123/32996

Recent Chinese Migration to Vietnam

Based on fieldwork conducted in various locations in Vietnam, this article examines the different types of Chinese migration to Vietnam since the normalization of Vietnam-China relations in 1990. The article notes differ-ences between the old and new Chinese migration. Recent Chinese migra-tion is characterized by the diversity in the composition of migrants. Furthermore, recent Chinese migration is fuelled by the government’s “go-out strategy” and is closely linked with increasing flows of investments, economic aid, trade and culture from China

 http://journals.sagepub.com/doi/abs/10.1177/011719681302200102
http://repository.vnu.edu.vn/handle/VNU_123/33017

Red blood cells decorated with functionalized core-shell magnetic nanoparticles: elucidation of the adsorption mechanism

The decoration of red blood cells (RBCs) with aminated and carboxylated core–shell magnetic nanoparticles (CSMNs) was studied and elucidated. It was demonstrated that only aminated CSMNs could decorate the RBCs and their adsorption interaction is mainly ruled by electrostatic attraction between the positively charged amino groups on CSMNs and the abundant sialic acidgroups on the outer surface of RBCs

 http://pubs.rsc.org/en/content/articlelanding/2013/cc/c3cc41513a/unauth#!divAbstract
http://repository.vnu.edu.vn/handle/VNU_123/33033

What can corporate governance build in shipping companies?

This empirical inquiry into shipping companies in Vietnam seeks to discern whether corporate governance influences organisational culture and leadership, which in turn influences upward influence behaviour. Structural equation modeling (SEM) was utilised for the analysis of 418 responses returned from self-administered structured questionnaires sent to 710 middle level managers. From the findings emerged the linkage pattern of strong corporate governance and its organisational outcomes such as adhocracy, market, and clan cultures or transformational leadership. Adhocracy, market, and clan cultures and transformational leadership were also found to cultivate organisationally beneficial upward influence strategies.

 http://www.inderscienceonline.com/doi/abs/10.1504/IJSTL.2013.053232
http://repository.vnu.edu.vn/handle/VNU_123/33034

Converse magnetoelectric effect in PZT/NiFe/CoFe nanocomposites

Magnetoelectric effect has attracted considerable interest due to the promising approach towards novel spintronics device. In this work, we study the converse magnetoelectric properties of PZT/NiFe/CoFe nanocomposites in which the piezoelectric substrate is transversely polarised and the thickness of the NiFe layer is varied. In these structures, the magnetic behaviour significantly changes under an applied voltage thanks to magnetoelectric coupling between the layers. By changing the NiFe thickness, this change in magnetisation reaches up to 245% at low bias magnetic field. Besides, the investigation of voltage controlled magnetisation switching is expounded. These results are discussed in term of a stress-induced anisotropy field model and magnetoelectric coupling between two phases.

 http://www.inderscienceonline.com/doi/abs/10.1504/IJNT.2013.053133
http://repository.vnu.edu.vn/handle/VNU_123/33035

Characteristics of colloidal copper particles prepared by using polyvinyl pyrrolidone and polyethylene glycol in chemical reduction method

A simple chemical reduction method is used to prepare colloidal copper nanoparticles where polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) are used as stabiliser, size controller and capping agents. The main purpose of this paper is to report about the large improvement in replacing PEG by PVP in the reduction synthesis ofcopper nanoparticles. From the TEM results it was found that colloidal copper nanoparticles prepared by using PVP and PEG are well-dispersed. From the UV-vis results, surface plasmon peak is very stable over time at 561 nm whereas when using (PEG) the peak shifts from 561 to 572 nm. This comparison also shows that copper nanoparticles in the solution using (PVP) have a less dispersed size distribution while presenting an equivalent mean diameter. Then it is observed that the oxidation time of copper nanoparticles at room temperature for solution using (PVP) is tenfold that of (PEG) capped nanoparticles

 http://www.inderscienceonline.com/doi/abs/10.1504/IJNT.2013.053143
http://repository.vnu.edu.vn/handle/VNU_123/33036

Ferroelectric-based nanocomposites: fabrication and characteristic properties

Ferroelectric ceramics are widely used in a variety of applications, ranging from high dielectric capacitors, mechanical actuators, micro-transducers to memory devices. Here we present chemical and physical processes to obtain nanocomposites based on ferroelectric perovskites, from metal-oxide to dual-phase oxide materials. The changes in the structural, dielectric and magnetic properties are studied. Interesting observations such as the percolation effect and anomaly in temperature dependence of magnetisation are also mentioned. The results are discussed in view of effects of the spatial distribution of each phase, the stress-induced structural phase transition and the ferroelectric-magnetic coupling. Additionally, recent results on epitaxial growth of PZT film on Si are presented.

http://www.inderscienceonline.com/doi/abs/10.1504/IJNT.2013.053149?journalCode=ijnt
http://repository.vnu.edu.vn/handle/VNU_123/33037

Rhenium mixed-ligand complexes with S,N, S-tridentate thiosemicarbazone/thiosemicarbazide ligands

Rhenium(V) complexes containing tridentate thiosemicarbazones/thiosemicarbazides (H2L1) derived from N-[N’,N’-dialkylamino(thiocarbonyl)]benzimidoyl chlorides with 4,4-dialkylthiosemicarbazides have been synthesized by ligand-exchange reactions starting from [ReOCl(L1)]. The chlorido ligand of [ReOCl-(L1)] (4) is readily replaced and reactions with ammonium thiocyanate or potassium cyanide give [ReO-(NCS)(L1)] (6) and [ReO(CN)(L1)] (7), respectively. The reaction of (NBu4)[ReOCl4] with H2L1 and two equivalents of ammonium thiocyanate, however, gives in a one-pot reaction [ReO(NCS)2(HL1)] (8), in which the pro-ligand H2L1 is only singly deprotonated. An oxo-bridged, dimeric nitridorhenium(V) com-pound of the composition [{ReN(HL1)}2O] (11) is obtained from a reaction of (NBu4)[ReOCl4], H2L1 and sodium azide. The six-coordinate complexes [ReO(L1)(Ph2btu)] (12), where HPh2btu isN,N-diphenyl-N’-benzoylthiourea, can be obtained by treatment of [ReOCl(L1)] with HPh2btu in the presence of NEt3. Studies of the antiproliferative effects of the [ReOX(L1)] system (X = Cl − , NCS − or CN − ) on breast cancer cells show that the lability of a monodentate ligand seems to play a key role in the cytotoxic activity of the metal complexes, while the substitution of this ligand by the chelating ligand Ph2btu − completely terminates the cytotoxicity.

 http://pubs.rsc.org/en/content/articlelanding/2013/dt/c3dt32950j#!divAbstract
http://repository.vnu.edu.vn/handle/VNU_123/33038

TRIGGER USING TRACK SEARCH AND KINENIATICAL ANALYSIS FOR RARE DECAY CHANNELS AT HIGH RATES

http://repository.vnu.edu.vn/handle/VNU_123/33039

We report on the definition and construction of the trigger system for the CP violation experiment with tagged K° (PS195) at LEAR, the low energy antiproton machine at CERN . The beam is assumed to have a continuous intensity of 2 x 10 6 antiprotons per second. The requirements for fast and efficient rejection are stringent .

Quantum chemical investigation of epoxide and ether groups in graphene oxide and their vibrational spectra

We present a detailed analysis of the factors influencing the formation of epoxide and ether groups in graphene nanoflakes using conventional density functional theory (DFT), the density-functional tight-binding (DFTB) method,p-Hu ¨ckel theory, and graph theoretical invariants. The relative thermodynamic stability associated with the chemisorption of oxygen atoms at various positions on hexagonal graphene flakes (HGFs) of D6h-symmetry is determined by two factors – viz. the disruption of the p-conjugation of the HGF and the geometrical deformation of the HGF structure. The thermodynamically most stable structure is achieved when the former factor is minimized, and the latter factor is simultaneously maximized. Infrared (IR) spectra computed using DFT and DFTB reveal a close correlation between the relative thermodynamic stabilities of the oxidized HGF structures and their IR spectral activities. The most stable oxidized structures exhibit significant IR activity between 600 and 1800 cm 1 , whereas less stable oxidized structures exhibit little to no activity in this region. In contrast, Raman spectra are found to be less informative in this respect.

http://pubs.rsc.org/en/Content/ArticleLanding/2013/CP/c3cp00094j#!divAbstract http://repository.vnu.edu.vn/handle/VNU_123/33040

Contamination of indoor dust and air by polychlorinated biphenyls and brominated flame retardants and relevance of non-dietary exposure in Vietnamese informal e-waste recycling sites

This study investigated the occurrence of polychlorinated biphenyls (PCBs), and several additive brominated flame retardants (BFRs) in indoor dust and air from two Vietnamese informal e-waste recycling sites (EWRSs) and an urban site in order to assess the relevance of these media for human exposure. The levels of polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), 1,2-bis-(2,4,6-tribromophenoxy) ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) in settled house dust from the EWRSs (130–12,000, 5.4–400, 5.2–620 and 31–1400 ng g −1 , respectively) were significantly higher than in urban house dust but the levels of PCBs (4.8–320 ng g −1 ) were not higher. The levels of PCBs and PBDEs in air at e-waste recycling houses (1000–1800 and 620–720 pg m −3 , respectively), determined using passive sampling, were also higher compared with non-e-waste houses. The composition of BFRs in EWRS samples suggests the influence from high-temperature processes and occurrence of waste materials containing older BFR formulations. Results of daily intakeestimation for e-waste recyclingworkers are ingoodagreementwith the accumulationpatterns pre-viously observed in human milk and indicate that dust ingestion contributes a large portion of the PBDE intake (60%–88%), and air inhalation to the low-chlorinated PCB intake (>80% for triCBs) due to their high levels in dust and air, respectively. Further investigation of both indoor dust and air as the exposure media for other e-waste recycling-relatedcontaminants andassessment of health risk associated withexposure to these contam-inant mixtures is necessary

 http://www.sciencedirect.com/science/article/pii/S0160412012002437
http://repository.vnu.edu.vn/handle/VNU_123/33042

A new lupane triterpene from Tetracera scandens L., xanthine oxidase inhibitor

From the MeOH extract of the stem ofTetracera scandensL., a newnor-lupane triterpene, 28-O-�-D-glucopyranosyl ester of platanic acid (1), has been isolated together with six known compounds. Their structures were elucidated on the basis of spectroscopic data. Compounds1–6displayed significant xanthine oxidase inhibitory activity in a concentration-dependent manner, and compound 4 showed more potent inhibitory activity with an IC50value of 1.9mM than that of a positive control allopurinol (IC502.5mM)

http://repository.vnu.edu.vn/handle/VNU_123/33043

Performance Evaluation of a Multi-User MIMO System With Prediction of Time-Varying Indoor Channels

In this paper, the performance of a multi-user multiple-input multiple-output (MIMO) system in time-varying channels is evaluated using measurement data. We consider the multi-user MIMO systemusing a block diagonalization (BD) schemeandaneigenbeam-space division multiplexing (E-SDM) technique. In an ideal case, the BD scheme eliminates inter-user interference, and the E-SDM technique suppresses inter-stream interference. In actual radio environments, however, channels change over time. This causes interference in the multi-user MIMO system even though the BD scheme and the E-SDM technique are used. To overcome this problem, the authors have developed a simple channel prediction scheme on the basis of alinear extrapolation and have demonstrated its effectiveness by computer simulations assumingthe Jakes’ model. To verify the performance of the channel prediction scheme in actual environments, we conducted a measurement campaign in indoor environments and measured a large amount of channel data. Using these data, we examined the channel transition and channel tracking with the prediction method. Then we obtained the bit-error rate (BER) performance. The prediction technique was shown to track the channel and improve the BER performance almost to that in the ideal time invariant case.

 http://ieeexplore.ieee.org/document/6280628/
http://repository.vnu.edu.vn/handle/VNU_123/33045

Self-absorption correction in determining the U-238 activity of soil samples via 63.3 keV gamma ray using MCNP5 code

The essential issue in analyzing the activity of 238 U in an HPGe detector based gamma spectrometer via 63.3 keV line is relating to the strong self-absorption of this weak gamma ray in sample material. The present work suggests a method of the self-absorption corrections for 63.3 keV gamma rays by a combination of experimental measurements and Monte Carlo MCNP5 calculations. The effects of sample chemical composition, density and geometry were calculated in terms of self-attenuation factors. The method, developed for a cylindrical sample geometry, accounted for variable sample heights and densities. The analysis of 238 U activity was applied for three main soil types in Vietnam, which are grey, alluvial and red soils. The results obtained with the above outlined method were in good agreement with those derived by other methods

 http://ieeexplore.ieee.org/document/6280628/
http://repository.vnu.edu.vn/handle/VNU_123/33047

Graphene sheets synthesized by ionic-liquid-assisted electrolysis for application in water purification

A facile and green synthesis of graphene sheets by ionic-liquid-assisted electrolysis was investigated in this work. The synthesized graphene sheets have been studied using transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray powder diffraction (XRD), Raman spectroscopy (Raman) and Fourier transform infrared (FTIR) analysis. The obtained graphene was used for the adsorption of Fe 2+ whose presence in the drinking water in wide areas of South Asia has been widely known. The result shows that the graphene could absorb Fe 2+ with a capacity of 299.3 mg/g which is 6 times higher than that of graphite oxide. The adsorption properties of metal ions on graphene and the effects of various factors on the adsorption capacity were also investigated in detail. The research results suggest a novel material for developing highly efficient water purification materials for the developing economies

 http://www.sciencedirect.com/science/article/pii/S0169433212017473
http://repository.vnu.edu.vn/handle/VNU_123/33049

Analysis of APC and IGFBP7 promoter gene methylation in Swedish and Vietnamese colorectal cancer patients

The tumour suppressor gene adenomatous polyposis coli (APC) is a key component that drives colorectal carci-nogenesis. The reported DNA methylation in the promoter of APC varies greatly among studies of colorectal cancer (CRC) in different populations. Insulin-like growth factor binding protein 7 (IGFBP7), also known as IGFBP-related protein 1 (IGFBP-rP1), is expressed in various tissue types, including the lung, brain, prostate and gastrointestinal tract, and has been suggested to play a tumour suppressor role against colorectal carcinogenesis. Studies have indicated that IGFBP7 is inacti-vated by DNA methylation in human colon, lung and breast cancer. In the present study, we used the methylation‑specific polymerase chain reaction to study the methylation status of the APC and IGFBP7 gene promoters in cancerous and paired normal tissue to evaluate its impact on clinical factors and association with ethnicity, represented by Swedish and Vietnamese CRC patients. We also investigated the distri-bution of CpG islands and the CpG dinucleotide density of each CpG island in the regions which were the subject of our investigation. Overall, normal tissue from Swedish patients exhibited a significantly higher frequency of IGFBP7 gene methylation in comparison with that of Vietnamese patients. Moreover, a significantly higher number of cancer tissues from Vietnamese individuals showed higher levels of methylation versus the paired normal tissue compared with that of Swedish patients. When we studied the methylation in cancer compared with the matched normal tissue in individuals, we found that a significantly higher number of Vietnamese patients had a higher degree of IGFBP7 gene methylation in cancer versus matched normal tissue in comparison with Swedish patients. Taken together, our results suggest that the methylation of the APC and IGFBP7 gene promoter region in cancerous tissue, in combination with the predominance of methylation in normal tissue, may serve as a prognostic factor in CRC patients

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3525353/
http://repository.vnu.edu.vn/handle/VNU_123/33051