E-Health Cloud Security Using Timing Enabled Proxy Re-Encryption

Mobile Networks and Applications - In the present era of Information Technology, almost all big and small scale companies are moving towards cloud to store and manage the data. Cloud computing is a...     

New barium,strontium and strontium‐doped barium squarates: synthesis,crystal structures and DNA/BSA binding,antioxidant and in vitro cytotoxicity studies

A new set of differently hydrated barium and strontium squarates, namely poly[[triaqua(μ‐1,2‐dioxocyclobut‐3‐ene‐1,2‐diolato)barium] monohydrate], {[Ba(C₄O₄)(H₂O)₃]·H₂O}_n ( 1 ), poly[[diaqua(μ‐1,2‐dioxocyclobut‐3‐ene‐1,2‐diolato)strontium] monohydrate], {[Sr(C₄O₄)(H₂O)₂]·H₂O}_n ( 2 ), and poly[[triaqua(μ‐1,2‐dioxocyclobut‐3‐ene‐1,2‐diolato)barium/strontium(0.85/0.15)] monohydrate], {[Ba_0.85Sr_0.15(C₄O₄)(H₂O)₃]·H₂O}_n ( 3 ), is reported. The study of their crystal structures indicates that all the complexes crystallize in the triclinic space group P. Complexes 1 and 3 have a rare combination of squarate units coordinated through monodentate O atoms to two different metal atoms and through two bidentate O atoms to three different metal atoms. Furthermore, they have three coordinated water molecules to give a coordination number of nine. The squarate ligands in complex 2 exhibit two different coordination modes: (i) monodentate O atoms coordinated to four different Sr atoms and (ii) two monodentate O atoms coordinated to two different metal atoms with the other two O atoms bidentate to four different Sr atoms. All the compounds decompose to give the respective carbonates when heated to 800 °C, as evidenced by thermogravimetry/differential thermal analysis (TG‐DTA), which are clusters of nanoparticles. Complexes 1 and 3 show additional endothermic peaks at 811 and 820 °C, respectively, indicating the phase transition of BaCO₃ from an orthorhombic (α‐Pmcn) to a trigonal phase (β‐R3m). All three complexes have significant DNA‐binding constants, ranging from 2.45 × 10⁴ to 9.41 × 10⁴ M^?1 against EB‐CT (ethidium bromide–calf thymus) DNA and protein binding constants ranging from 1.1 × 10⁵ to 8.6 × 10⁵ with bovine serum albumin. The in vitro cytotoxicity of the complexes is indicated by the IC₅₀ values, which range from 128.8 to 261.3 µg ml^?1. Complex 3 shows better BSA binding, antioxidant activity against the DPPH radical and cytotoxicity than complexes 1 and 2 .