Cochin University of Science and Technology

About: Cochin University of Science and Technology is a education organization based out in Kochi, Kerala, India. It is known for research contribution in the topics: Thin film & Natural rubber. The organization has 5382 authors who have published 7690 publications receiving 103827 citations. The organization is also known as: CUSAT & Cochin University.

Brønsted acidic ionic liquids derived from alkylamines as catalysts and mediums for Fischer esterification: Study of structure–activity relationship

Abstract: Esterification of acetic acid with 1-octanol was studied using a series of alkylammonium salts as Bronsted acidic ionic liquids. The following ionic liquids were prepared and used as catalysts and mediums in the esterification reaction; [Et3NH][HSO4], [Et3NH][H2PO4], [Et3NH][BF4], [Et3NH][p-CH3C6H4SO3], [Et2(PhCH2)NH][HSO4], [n-Bu3NH][HSO4], [n-Oct3NH][HSO4], [Et2NH2][HSO4], [Et2NH2][H2PO4], [Et2NH2][BF4], [i-Pr2NH2][HSO4], [EtNH3][HSO4], [EtNH3][H2PO4], and [EtNH3][BF4]. Higher acidity of the anion in the ionic liquid resulted in high yield of the ester. Yield of the ester decreased with increase in the size of the cation. There was no phase separation in the reactions where size of anion and/or cation was bigger.

Effect of the excitation source on the quantum-yield measurements of rhodamine B laser dye studied using thermal-lens technique.

Abstract: A dual-beam transient thermal-lens technique was employed for the determination of absolute fluorescence quantum-yield measurements of Rhodamine B laser dye in different solvents. We investigated the effect of excitation on the absolute fluorescence quantum yield of Rhodamine B. 514 nm radiation from an argon ion laser was used as a cw excitation source and 532 nm pulses from a Q-switched Nd:YAG laser were used as a pulsed excitation source. The fluorescence quantum-yield values were found to be strongly influenced by environmental effects as well as the transient nature of the excitation beam. Our results also indicate that parameters, like the concentration of the dye solution, aggregate formation and excited state absorption, affect the absolute values of the fluorescence yield significantly.

Phage Display Identification of CD100 in Human Atherosclerotic Plaque Macrophages and Foam Cells

Abstract: Atherosclerosis is a complex disease in which vessels develop plaques comprising dysfunctional endothelium, monocyte derived lipid laden foam cells and activated lymphocytes. Considering that humans and animal models of the disease develop quite distinct plaques, we used human plaques to search for proteins that could be used as markers of human atheromas. Phage display peptide libraries were probed to fresh human carotid plaques, and a bound phage homologous to plexin B1, a high affinity receptor for CD100, was identified. CD100 is a member of the semaphorin family expressed by most hematopoietic cells and particularly by activated T cells. CD100 expression was analyzed in human plaques and normal samples. CD100 mRNA and protein were analyzed in cultured monocytes, macrophages and foam cells. The effects of CD100 in oxLDL-induced foam cell formation and in CD36 mRNA abundance were evaluated. Human atherosclerotic plaques showed strong labeling of CD100/SEMA4D. CD100 expression was further demonstrated in peripheral blood monocytes and in in vitro differentiated macrophages and foam cells, with diminished CD100 transcript along the differentiation of these cells. Incubation of macrophages with CD100 led to a reduction in oxLDL-induced foam cell formation probably through a decrease of CD36 expression, suggesting for the first time an atheroprotective role for CD100 in the human disease. Given its differential expression in the numerous foam cells and macrophages of the plaques and its capacity to decrease oxLDL engulfment by macrophages we propose that CD100 may have a role in atherosclerotic plaque development, and may possibly be employed in targeted treatments of these atheromas.