Trifostigmanoside I,an Active Compound from Sweet Potato,Restores the Activity of MUC2 and Protects the Tight Junctions through PKCα/β to Maintain Intestinal Barrier Function

Sweet potato (Ipomoea batata) is considered a superfood among vegetables and has been consumed for centuries. Traditionally, sweet potato is used to treat several illnesses, including diarrhea and stomach disorders. This study aimed to explore the protective effect of sweet potato on intestinal barrier function, and to identify the active compounds of sweet potato and their underlying mechanism of action. To this purpose, bioactivity-guided isolation, Western blotting, and immunostaining assays were applied. Interestingly, our bioactivity-guided approach enabled the first isolation and identification of trifostigmanoside I (TS I) from sweet potato. TS I induced mucin production and promoted the phosphorylation of PKCα/β in LS174T human colon cancer cells. In addition, it protected the function of tight junctions in the Caco-2 cell line. These findings suggest that TS I rescued the impaired abilities of MUC2, and protected the tight junctions through PKCα/β, to maintain intestinal barrier function.     

Design and fabrication of low cost solar water heaters

We designed two types of very low cost solar water heaters which do not need a water supply connection. The first one consisted of two plastic bowls, one inside the other with 5 cm thickness of insulation in between. A transparent plastic cover was tied around the smaller vessel. It was found that water placed inside the smaller vessel had its temperature raised by 18°C from the ambient temperature within four hours when the average insolation was about 600 kWh/m². The second one consisted of two earthen vessels in place of plastic bowls. The water temperature rise was 20°C under the same radiation. If either of the heaters was covered with cotton-wool insulation in the afternoon, the temperature remains 13°C above the ambient early next morning. The cost of the material was around US$ 4.50 for the plastic bowl heater while this is around US$ 3.50 for the earthen vessel water heater.     

Parametric Investigation and Design of Junctionless Nanowire Tunnel Field Effect Transistor

Silicon - An integrated design based on Gate-All-Around (GAA) silicon Junctionless (JL) vertical profile Nanowire (NW) structure has been proposed for JL-NW-Tunnel-Field Effect Transistor...     

Study of Antibacterial Activity of Metal Nanoparticle Absorbed Fly‐Ash based Ceramics

The bactericidal action of silver nanoparticles has been observed by many researchers since few years. In this study, we have developed an antibacterial ceramics (ACs) by absorbing synthesized silver nanoparticles within the ceramic matrix developed by us from an abundantly available coal fly ash, an extremely hazardous by‐product of thermal power plants. Nanoparticles dispersions of different particle sizes were made absorbed in to the ceramic matrix to evaluate its bactericidal activity against both Staphylococcus aureus (Gram‐positive) and Escherichia coli (Gram‐negative) bacteria, taken as the model microorganisms. This study showed that the total bactericidal action of ACs depends on the size of absorbed nanoparticles and the content of nanoparticles in the dispersions within the ceramic matrix. ACs thus developed release very slowly a minute amount of nanoparticles and show strong and prolonged bactericidal activity against pathogenic strain of both types of bacteria. The concentration of prepared nanoparticles in dispersion and the concentration of released nanoparticles in aqueous medium from the absorbed ceramic matrix were measured using inductively coupled plasma spectrophotometer. The mechanism of the antibacterial action was also studied using transmission electron microscopy image analysis of the bacterial cross‐section of both types of bacteria.     

Influence of calcium substitution on structural and electrical properties of substituted barium titanate

Ba_0.80−xCa_xPb_0.20Ti_0.90Zr_0.10O₃ ceramics (x = 0, 0.10 and 0.20) were synthesized by solid state reaction. Samples microstructure and dielectric, ferroelectric and piezoelectric properties were studied. Dielectric constant (?), coercive field (E_c), remanent polarization (P_r) and ratio of remanent to spontaneous polarization (P_r/P_s) were studied at different temperatures. Sample with x = 0.10 was found to have maximum and comparatively more stable P_r/P_s ratio over a wide temperature range. Dielectric loss was found to improve with increase in x whereas piezoelectric charge coefficient d₃₃ was found to decrease with increase in x.     

New antimicrobial agents: The synthesis of Schiff base polymers containing transition metals and their characterization and applications

A new polymeric Schiff base containing formaldehyde and 2‐thiobarbituric acid moieties was synthesized by the condensation of a monomeric Schiff base derived from 2‐hydroxyacetophenone and hydrazine. Polymer–metal complexes were also synthesized by the reaction of the polymeric Schiff base with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) acetate. The polymeric Schiff base and its polymer–metal complexes were characterized with magnetic moment measurements, elemental analyses, and spectral techniques (infrared, ¹H‐NMR, and ultraviolet–visible). The thermal behaviors of these coordination polymers were studied by thermogravimetric analysis in a nitrogen atmosphere up to 800°C. The thermal data revealed that all of the polymer–metal complexes showed higher thermal stabilities than the polymeric Schiff base and also ascribed that the Cu(II) polymer–metal complex showed better heat resistant properties than the other polymer–metal complexes. The antimicrobial activity was screened with the agar well diffusion method against various selected microorganisms, and all of the polymer–metal complexes showed good antimicrobial activity. Among all of the complexes, the antimicrobial activity of the Cu(II) polymer–metal complex showed the highest zone of inhibition because of its higher stability constant and may be used in biomedical applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and characterization of new polybenzoxazines from renewable resources for bio‐composite applications

Renewable natural resources such as eugenol, furfurylamine, stearylamine, and jute fiber were used to prepare polybenzoxazine composites. The purity of eugenol which is extracted from clove was confirmed by gas chromatography. FTIR, ¹H, and ¹³C NMR spectroscopic analysis were used to determine the structure of eugenol and the benzoxazine monomers namely 6‐allyl‐3‐furfuryl‐8‐methoxy‐3,4‐dihydro‐2H‐1,3‐benzoxazine (EF‐Bz) and 6‐allyl‐3‐octadecyl‐8‐methoxy‐3,4 dihydro‐2H‐1,3‐benzoxazine (ES‐Bz) synthesized from it. The curing analysis from differential scanning calorimetric analysis shows that the onset of curing is shifted to lower temperature (161°C) for EF‐Bz, when compared with ES‐Bz (174°C). The thermal stability analyzed from thermogravimetric analysis shows that the polybenzoxazine EF‐Pbz has higher thermal stability (T_5% = 361°C) with that of ES‐Pbz (T_5% = 313°C). The storage modulus, tensile, and flexural strength of the EF‐Bz/Jute fiber composite show high value when compared with ES‐Bz/Jute fiber composites. POLYM. COMPOS., 37:1821–1829, 2016. © 2014 Society of Plastics Engineers     

Direct esterification of fatty acids with phenylalkanols by using dicyclohexylcarbodiimide

A mild one‐pot esterification method of fatty acids with alcohols at room temperature is described. The reaction of undec‐10‐enoic acid (I) with 1‐phenylethanol in the presence of N,N'‐di‐cyclohexylcarbodiimide and 4‐(N,N‐dimethylamino)pyridine gave 1'‐phenylethyl undec‐10‐enoate in quantitative yield. Similar reactions were also carried out with (Z)‐octadec‐9‐enoic acid, (Z)‐12‐hydroxyoctadec‐9‐enoic and (Z)‐9‐hydroxyoctadec‐12‐enoic acids. In addition, compound (I) was allowed to react with diphenyl methanol to form its corresponding ester. The structure elucidation of the prepared esters is based on the elemental analysis and spectral data (IR, ¹H‐ and ¹³C‐NMR, MS).     

People versus Power: The Geopolitics of Kaptai Dam in Bangladesh

This paper examines the impacts of the Kaptai dam, in the Chittagong Hill Tracts of Bangladesh, on the tribal communities of that area. Kaptai dam is the only hydropower source in Bangladesh, with an installed capacity of 230 MW; about 5% of the electricity consumed in the country is produced there. When the dam was built in 1962, some 100 000 people were displaced and few of them received adequate compensation. Recently, the Power Development Board (PDB) of Bangladesh has announced a plan to install two new 50 MW units that will bring the capacity of the dam to 330 MW. This plan will cause the reservoir water level to rise and may take away about 7500 ha of the fringe land, which the tribal people use for rice cultivation during the April-August period each year. As before, the PDB has not discussed this plan with the potentially affected tribal groups, who are concerned about losing the fringe land and an important source of income. The paper discusses the original displacement issue and this recent development in the light of the geopolitical history of this region. It attempts to present an objective analysis of these issues and views held by various concerned parties. It then proposes a scheme for managing the Kaptai reservoir based on a participatory approach that will ensure both economic efficiency and social equity.