Central University of Kerala

About: Central University of Kerala is a education organization based out in Kāsaragod, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 556 authors who have published 881 publications receiving 7474 citations.

On square sum graphs

Abstract: A (p, q)-graph G is said to be square sum, if there exists a bijection f : V(G) — {0,1, 2,...,p — 1} such that the induced function f * : E(G) — N given by f * (uv) = (f (u))2 + (f (v))2 for every uv G E(G) is injective. In this paper we initiate a study on square sum graphs and prove that trees, unicyclic graphs, mCn,m > 1,cycle with a chord, the graph obtained by joining two copies of cycle Cn by a path Pk and the graph defined by path union of k copies of Cn, when the path Pn = P2 are square sum.

Cytotoxicity of nanoparticles - Are the size and shape only matters? or the media parameters too?: a study on band engineered ZnS nanoparticles and calculations based on equivolume stress model.

Abstract: Size dependent cytotoxicity of ZnS nanoparticles (NPs) was investigated in Human embryonic kidney (HEK-293) cell lines by MTT assay. The cells were incubated with varying concentration of ZnS NPs of sizes 4 nm, 10 nm and 25 nm for 48 h under different (cell culture) media viscosity conditions. The results showed that the toxicity is decreased with the particle size while it is negatively correlated with the viscosity of the media. Theoretical calculations were performed, by assuming equivolume stress model and the same is explained with schematics. Similarly, the effect of particle size and shape on toxicity is explained based on the theoretical calculation of the stress. The calculations showed that out of the possible cellular entry mechanisms for the cubic or cage shaped NPs, the highest toxicity is predicted for the entry through the corners while the lowest toxicity is predicted for the entry through the faces. The experimental observations depicting the cytotoxicity as a function of the viscosity of cell culture media was also validated by stress calculations and are found to be consistent. Studies on size and shape dependence of semiconductor NPs like ZnS is rather scarce, while the role of viscosity of cell culture media on the cytotoxicity is being reported for the first time. In summary, the study indicates that the cytotoxicity is an integral function of size and shape of NPs, physical parameters of the cell culture media in addition to the post entry biochemical interactions with the host cell.