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Huyện Sông Thao, Vietnam

Thanh N.D.,University of science | Van H.T.K.,Viet Tri University of Industry | Thu T.T.,University of science
Journal of Carbohydrate Chemistry

A set of reaction conditions, including ionic liquids as catalysts, water as solvent and microwave-assisted heating method, had been investigated for the synthesis of hepta-O-acetyl-β-D-lactosyl thiosemicarbazones. Based on optimized conditions, namely, [HO(CH2)2NH3][OAc] as catalyst, water as solvent and 300 W microwave power, a series of substituted benzaldehyde hepta-O-acetyl-β-D-lactosyl thiosemicarbazones was synthesized by reaction of hepta-O-acetyl-β-D-lactosyl thiosemicarbazide with the corresponding substituted benzaldehydes. The high yields of 90-97% were achieved. Almost all of the obtained thiosemicarbazones exhibited remarkable antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis, Enterobacter, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumonia in comparison with sulphamethoxazole and trimethoprim as drug references and antifungal activity against Aspergillus Niger, Candida albicans and Saccharomyces cerevisiae in comparison with clotrimazole as drug reference. MIC values of the compounds range from 39.1 to 2500 μg/mL for bacterial activity and from 0.25 to 25.6 μg/mL for fungal activity. © Copyright 2015 Taylor & Francis Group, LLC. Source

Jin H.,Korea University | Lee K.W.,Korea University | Khi N.T.,Korea University | Khi N.T.,Viet Tri University of Industry | And 9 more authors.

Shape-controlled Pt-based seeds lead to completely different M/Pt (M = Ru or Rh) structures of nanobox or octapod. Unusually high catalytic activities of Pt@Ru octapod toward the oxygen evolution reaction are observed due to a core-shell effect. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Ohki K.,Fukui Prefectural University | Le N.Q.T.,Japan Advanced Institute of Science and Technology | Yoshikawa S.,Fukui Prefectural University | Kanesaki Y.,Tokyo University of Agriculture | And 3 more authors.
Journal of Applied Phycology

A unicellular cyanobacterium that produces a large amount of exopolysaccharide (EPS) was isolated from a rice field in Phu Tho Province, Vietnam. Morphological characteristics and phylogenetic analysis using a partial sequence of the 16S rRNA gene revealed that the isolate was closely related to the genus Cyanothece. The isolate, named Cyanothece sp. Viet Nam 01, grew at a wide range of temperatures (25-40 °C), but was not viable below 20 °C. The isolate had an ability of aerobic nitrogen fixation. The EPS was purified using NaOH extraction and ethanol precipitation, and the absolute molecular weight was estimated to be 4.5 × 104 kDa. The pattern of the Fourier transform infrared spectrum indicated that the EPS had carbonyl and sulfate groups, as well as the typical functional groups of sugars. The uronic acid and sulfur contents were 23 and 8.4 mol% per total monosaccharide, respectively. The EPS constituent monosaccharides were rhamnose, glucose, galactose, xylose, mannose, fucose, arabinose, ribose, and unknown sugar, with molar compositions of 38.6:13.8:4.8:4.8:2.4:3.5:2.0:0.6:6.5, respectively. © 2013 Springer Science+Business Media Dordrecht. Source

Khi N.T.,Korea University | Khi N.T.,Viet Tri University of Industry | Park J.,Korea University | Baik H.,Korea Basic Science Institute | And 3 more authors.

Facet-controlled dendritic nanostructures are expected to exhibit excellent catalytic properties because both aggregation-free nature and controlled facet-originated activity and selectivity can be accomplished. However, such examples are extremely rare due to the incompatibility of the dendrite formation process with the usage of surface-stabilizing moieties, which are typically used to control facets. Herein, we demonstrate that regiospecific growth on a facet-controlled core nanoparticle can induce the facet-control of the branch nanoparticles. Specifically, facet-controlled dendritic nanostructures of {100}Rh-Pt and {100}Pt-Pt can be conveniently prepared by transferring the crystallographic behaviour of the {100}Pt dendritic core nanocube to the {100}Rh or {100}Pt branch nanocubes. This journal is © The Royal Society of Chemistry. Source

An H.,Korea University | Khi N.T.,Korea University | Khi N.T.,Viet Tri University of Industry | Yoon J.,Korea University | And 4 more authors.

Simultaneously growing multiple nanocrystallites in a crowded space can cause a shortage of precursors, and this can lead to a vertical growth of nanocrystallites on a given substrate. The presence of surfactant-surfactant interactions among adjacent nanocrystals can also place a unique structural constraint on the growing nanocrystallites, resulting in novel nanocrystal facet control. Herein, we report the growth of Rh on Au@Pt nanowires with multiple twinning boundaries, which are found along the entire nanowire length. The Au@Pt nanowires exhibit numerous bead-like structures, resulting from the preferred Pt deposition on the twinning boundaries, which can serve as nucleation sites for Rh. The heteroepitaxial growth of Rh on the Au@Pt nanowires results in unusual crystal growth behaviours. First, novel morphologies of Rh nanorods, nanoplates, and tangled manes are obtained temperature-dependently, which are not obtained in the absence of the Au@Pt nanowire substrate. Secondly, the thickness of vertically grown nanorods and nanoplates is tightly controlled. We also report the structure-catalytic activity relationship on the catalytic hydrogenation of phthalimides by the new Rh nanostructures. This journal is © The Royal Society of Chemistry. Source

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