Study on conformational structure of tamarind seed polysaccharide and its sulfated derivative by light scattering method

The aim of this study was to study the conformational changing when sulfated groups were introduced to the molecular chain of native tamarind seed polysaccharide (TSP). Light Scattering (LS) method was used to determine conformation of TSP and its sulfated derivative TSPS. The results indicated that both TSP and TSPS have a highly branched and more sphere-like molecule; however, after sulfation, the TSPS became more branched structure than native polysaccharide. Keywords. Tamarind seed polysaccharide, conformation, light scattering

PRELIMINARY SURVEY OF WATER ENVIRONMENT PROBLEMS IN HCMC

Joint Research on Environmental Science and Technology for the Eart

Anticaries activity of mangiferin isolated from Mangifera indica leaves in Vietnam

Mangiferin (1) was isolated from Vietnamese Mangifera indica leaves. Its antimicrobial activities against the oral bacterium Streptococcus mutans GS-5 were evaluated in terms of inhibition of acid production and biofilm formation. The obtained results indicated that mangiferin at the concentration of 0.5 mM clearly inhibited acid production by this organism with a final pH value of 5.2 compared to 3.9 of the control. The reduction in biofilm biomass was found up to 92 % when it was treated with 1.0 mM mangiferin. Thus, mangiferin possesses moderate anticaries activity against S. mutans GS-5. Keywords. Mangifera indica, mangiferin, Streptococcus mutans, anticaries activity

Analyzing the farmers’ preferences of contract for farming and agricultural product consumption in Soc Trang province

Nghieân cöùu taäp trung phaân tích sôû thích cuûa noâng daân ñoái vôùi hôïp ñoàng canh taùc vaø tieâu thuï noâng saûn vôùi coâng ty thu mua thoâng qua phöông phaùp thöïc nghieäm löïa choïn vaø phoûng vaán tröïc tieáp 111 noâng daân troàng caây troàng caïn taïi tænh Soùc Traêng. Keát quaû nghieân cöùu cho thaáy, noâng daân thích caùc hôïp ñoàng coù giaù noâng saûn cao hôn giaù thò tröôøng. Vieäc coâng ty thu mua cung caáp ñaàu vaøo cho noâng daân trong quaù trình saûn xuaát cuõng laø moät yeáu toá quan troïng thu huùt noâng daân ñoàng yù tham gia hôïp ñoàng. Beân caïnh ñoù, noâng daân thích baùn noâng saûn taïi ruoäng hôn laø töï vaän chuyeån noâng saûn ñeán ñieåm thu mua

Structure, conformation in aqueous solution and antimicrobial activity of ulvan extracted from green seaweed <i>Ulva reticulata</i>

<p>The aim of this study is to elucidate the structure and investigate the antimicrobial activity of an ulvan obtained by water extraction from green seaweed <i>Ulva reticulata</i> collected at Nha Trang sea of Vietnam by using IR, NMR, SEC-MALLS and SAXS methods. The ulvan is composed of rhamnose, galactose, xylose, manose and glucose (mole ratio Rha: Gal: Xyl: Man: Glu = 1:0.12:0.1:0.06:0.03), uronic acid (22.5%) and sulphate groups (17.6%). Chemically structural determination showed that the ulvan mainly composed of disaccharide [→4)β-D-GlcA(1→4)α-L-Rha3S-(1→]. The results from SAXS indicated that ulvan under study has a rod-like bulky chain conformation. Ulvan from <i>U.</i> <i>reticulata</i> showed high antimicrobial activity, with inhibition zone diameter of 20 mm against <i>Enterobacter cloace</i> and 18 mm against <i>Escherichia</i> <i>coli</i>.</p

Efficient heat batteries for performance boosting in solar thermal cooking module

Heat batteries show outstanding charging and discharging thermal energy capability with the latent heat of fusion (Hm) for solar thermal application. In this work, novel magnesium nitrate hexahydrate (MNH) based heat batteries are fabricated and tested for 1000 sequential thermal cycles. The MNH heat batteries demonstrate a high level of operational stability with the least corrosive rate. Real-time performance of the heat batteries was studied by incorporating them in the parabolic solar thermal cooking module. The developed MNH heat batteries based solar cooking module illustrates excellent heat retention capacity over 6 h after the sunshine. Temperature profiles under no load and full load conditions reveal the moderation and enhancement in the solar thermal cooking module's operational efficiencies. The solar cooking module's efficiency with the heat batteries reaches a maximum of 22.8% and 42.5%, under no load and full load conditions, respectively. Real-time cooking capacity with different edible materials under both outdoor and indoor environments proves the effective performance. Further, it is estimated that MNH heat batteries can be in full performance for a minimum of 2 years with maintenance-free and emission-free operations