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: Catalysis & Excited state. The organization has 3867 authors who have published 10457 publications receiving 220098 citations.

Myoblast differentiation of human mesenchymal stem cells on graphene oxide and electrospun graphene oxide-polymer composite fibrous meshes: importance of graphene oxide conductivity and dielectric constant on their biocompatibility

Abstract: Recently graphene and graphene based composites are emerging as better materials to fabricate scaffolds. Addition of graphene oxide (GO) nanoplatelets (GOnPs) in bioactive polymers was found to enhance its conductivity (σ) and, dielectric permittivity (ϵ) along with biocompatibility. In this paper, human cord blood derived mesenchymal stem cells (CB-hMSCs) were differentiated to skeletal muscle cells (hSkMCs) on spin coated thin GO sheets composed of GOnPs and on electrospun fibrous meshes of GO-PCL (poly-caprolactone) composite. Both substrates exhibited excellent myoblast differentiations and promoted self-alignedmyotubesformation similar to natural orientation. σ, ϵ, microstructural and vibration spectroscopic studies were carried out for the characterizations of GO sheet and the composite scaffolds. Significantly enhanced values of both σ and ϵ of the GO-PCL composite were considered to provide favourable cues for the formation of superior multinucleated myotubes on the electrospun meshes compared to those on thin GO sheets. The present results demonstrated that both substrates might be used as potential candidates for CB-hMSCs differentiation and proliferation for human skeletal muscle tissue regeneration.

Direct observation of intermediates formed during steady-state electrocatalytic O2 reduction by iron porphyrins

Abstract: Heme/porphyrin-based electrocatalysts (both synthetic and natural) have been known to catalyze electrochemical O2, H(+), and CO2 reduction for more than five decades. So far, no direct spectroscopic investigations of intermediates formed on the electrodes during these processes have been reported; and this has limited detailed understanding of the mechanism of these catalysts, which is key to their development. Rotating disk electrochemistry coupled to resonance Raman spectroscopy is reported for iron porphyrin electrocatalysts that reduce O2 in buffered aqueous solutions. Unlike conventional single-turnover intermediate trapping experiments, these experiments probe the system while it is under steady state. A combination of oxidation and spin-state marker bands and metal ligand vibrations (identified using isotopically enriched substrates) allow in situ identification of O2-derived intermediates formed on the electrode surface. This approach, combining dynamic electrochemistry with resonance Raman spectroscopy, may be routinely used to investigate a plethora of metalloporphyrin complexes and heme enzymes used as electrocatalysts for small-molecule activation.

Bifunctionalized Mesoporous SBA-15: A New Heterogeneous Catalyst for the Facile Synthesis of 5-Hydroxymethylfurfural

Abstract: Bifunctional porous nanomaterials are very demanding in the context of heterogeneous catalysis. A highly ordered 2D-hexagonal bifunctionalized mesoporous SBA-15 type material MPBOS (mesoporous bifunctionalized organosilica) has been synthesized via a post synthetic route. The surface of the SBA-15 has been functionalized with (3-chloropropyl)triethoxysilane to obtain MPCOS (mesoporous chloro-substituted organosilica) material, which undergoes an SN2 substitution reaction of the surface a grafted chloro group with the amine group of organic ligand 5-aminoisophthalic acid, in the presence of potassium carbonate under refluxing conditions, offering the bifunctional material MPBOS. The bifunctionalized material with exceptionally high Brunauer–Emmett–Teller (BET) surface area of 652 m2 g–1 and average pore diameter of 9.4 nm has been characterized thoroughly with powder X-ray diffraction (PXRD), N2 sorption analysis, solid state 13C cross-polarization magic angle spinning nuclear magnetic resonance (CP MAS NM...