Indian Association for the Cultivation of Science

About: Indian Association for the Cultivation of Science is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Excited state & Catalysis. The organization has 3867 authors who have published 10457 publications receiving 220098 citations.

Inhibition of Amyloid Fibril Growth and Dissolution of Amyloid Fibrils by Curcumin–Gold Nanoparticles

Abstract: Inhibition of amyloid fibrillation and clearance of amyloid fibrils/plaques are essential for the prevention and treatment of various neurodegenerative disorders involving protein aggregation. Herein, we report curcumin-functionalized gold nanoparticles (Au-curcumin) of hydrodynamic diameter 10-25 nm, which serve to inhibit amyloid fibrillation and disintegrate/dissolve amyloid fibrils. In nanoparticle form, curcumin is water-soluble and can efficiently interact with amyloid protein/peptide, offering enhanced performance in inhibiting amyloid fibrillation and dissolving amyloid fibrils. Our results imply that nanoparticle-based artificial molecular chaperones may offer a promising therapeutic approach to combat neurodegenerative disease.

Tuning the Size of CsPbBr3 Nanocrystals: All at One Constant Temperature

Abstract: For varying the size of perovskite nanocrystals, variation in the reaction temperature and tuning the ligand chain lengths are established as the key parameters for high-temperature solution-processed synthesis. These also require sharp cooling for obtaining desired dimensions and optical stability. In contrast, using preformed alkylammonium bromide salt as the precise dimension-controlling reagent, wide window size tunable CsPbBr3 nanocrystals were reported without varying the reaction temperature or changing the ligands. The size tunability even with ∼1 nm step growth regimes was achieved as a function of only the concentration of added alkylammonium bromide salt. Not only the cube shape but also the width varied in the sheet structures. Because these nanostructures lose their optical stability and crystal phase on prolonged annealing, stabilizing these in high-temperature synthesis for all-inorganic lead halide perovskites is important and remains challenging. In this aspect, this method proved to be m...

Transition-Metal Decoration Enhanced Room-Temperature Hydrogen Storage in a Defect-Modulated Graphene Sheet

Abstract: Using first-principles density functional calculations, we show that a transition-metal (TM)-doped defected graphene sheet with periodic repetition of a C atom vacancy (Vc) can be used as a promising system for hydrogen storage. The TM atoms adsorbed above and below the defected site are found to have a strong bonding to the graphene sheet, thereby circumventing the problem of TM clustering, which is the main impediment for efficient hydrogen storage in nanostructure systems. The results reveal that, when the vacancy-modulated graphene sheet is decorated on both sides by a combination of less than half-filled (TM1) and more than half-filled (TM2) elements, it results in the adsorption of molecular hydrogen with a binding energy lying in the desirable energy window. Among all the different TM1−TM2 combinations at a C vacancy site, Fe−Ti turns out to be the best choice where five H2 molecules get attached on each pair. To underscore the stability of these hydrogenated systems, we have performed an ab initio...

Complete Transmetalation in a Metal–Organic Framework by Metal Ion Metathesis in a Single Crystal for Selective Sensing of Phosphate Ions in Aqueous Media

Abstract: A complete transmetalation has been achieved on a barium metal-organic framework (MOF), leading to the isolation of a new Tb-MOF in a single-crystal (SC) to single-crystal (SC) fashion. It leads to the transformation of an anionic framework with cations in the pore to one that is neutral. The mechanistic studies proposed a core-shell metal exchange through dissociation of metal-ligand bonds. This Tb-MOF exhibits enhanced photoluminescence and acts as a selective sensor for phosphate anion in aqueous medium. Thus, this work not only provides a method to functionalize a MOF that can have potential application in sensing but also elucidates the formation mechanism of the resulting MOF.

Quest for mode of binding of 2-(4-(dimethylamino)styryl)-1-methylpyridinium iodide with calf thymus DNA.

Abstract: The mode of binding of 2-(4-(dimethylamino)styryl)-1-methylpyridinium iodide (DASPMI) with calf thymus DNA as revealed from different steady state and time-resolved emission spectroscopic measurements has been reported in this paper. Fluorescence enhancement of DASPMI and its quenching by potassium iodide (KI) points to groove binding of dye with ct-DNA, rather than intercalation in the ct-DNA helix. An increase in steady state anisotropy and fluorescence lifetime hints at binding with ct-DNA. The value of binding constant from emission and association constant from circular dichroic spectrum also indicates weak binding. The strong dependence on ionic strength or salt in controlling the binding of DASPMI with ct-DNA by electrostatic interaction confirms groove binding. The high semicone angle of DASPMI in ct-DNA certainly rules out the possibility of intercalated bonding. A theoretical modeling shows that the probe is bound to ct-DNA as a crescent with a curvature of 11.35 A, which is the previously known curvature of probe in the minor groove.