Asymptotic and Partial Asymptotic Hankel Operators on $$H^2(\mathbb{D}^n)$$ H 2 ( D n ) )

In this paper, we generalize the concept of asymptotic Hankel operators on H²(D) to the Hardy space H²(Dⁿ) (over polydisk) in terms of asymptotic Hankel and partial asymptotic Hankel operators and investigate some properties in case of its weak and strong convergence. Meanwhile, we introduce i^th-partial Hankel operators on H²(Dⁿ) and obtain a characterization of its compactness for n > 1. Our main results include the containment of Toeplitz algebra in the collection of all strong partial asymptotic Hankel operators on H²(Dⁿ). It is also shown that a Toeplitz operator with symbol φ is asymptotic Hankel if and only if φ is holomorphic function in L^∞(Tⁿ).     

Synthesis and Biological Activity of New Resveratrol Derivative and Molecular Docking: Dynamics Studies on NFkB

Resveratrol (RVS) is a naturally occurring antioxidant, able to display an array of biological activities. In the present investigation, a new derivative of RVS, RVS(a), was synthesized, and its biological activity was determined on U937 cells. It was observed that RVS(a) showed pronounced activity on U937 cells than RVS. RVS(a) is able to induce apoptosis in tumor cell lines through subsequent DNA fragmentation. From the EMSA results, it was evident that RVS(a) was able to suppress the activity of NFkB by interfering its DNA binding ability. Furthermore, the molecular interaction analysis (docking and dynamics) stated that RVS(a) has strong association with the IkB-alpha site of NFkB compared with RVS; this binding nature of RVS(a) might be prevent the NFkB binding ability with DNA. The present findings represent the potential activity of propynyl RVS on U937 cells and signifying it as a one of putative chemotherapeutic drugs against cancer.     

Biocompatibility studies on polyaniline and polyaniline-silver nanoparticle coated polyurethane composite

Biocompatibility of medical grade polyurethane coated with polyaniline (PANi) and polyaniline-silver nanoparticle composite (PANi-AgNp) is reported here. These modified films showed 23 and 18% of 3T3 L1 cell death when compared to 41% with virgin polyurethane (PU) after 48h of incubation, respectively. All the surfaces elucidated inflammatory response in the form of enhanced expressions of the proinflammatory cytokines genes, TNF-α and IL-6. But these values were less (by 20%) on modified films than on the bare PU. Attachment of Pseudomonas and Bacillus were markedly less on PANi-AgNp coated surface (by 90.6 and 50.5%, respectively) when compared to the uncoated PU. As the CFU counts decreases on the nanoparticle coated PU, the adsorbed carbohydrate as well as protein content on to the surface of polymer decreases accordingly, indicating less attachment. A 20% reduction in the thickness of biofilm was observed in PANi-AgNp coated PU surface. A very strong positive correlation is observed between the contact angles of the polymers and the various biological parameters (namely colony forming units, protein, carbohydrate, cell death and inflammatory response), indicating hydrophilic surfaces prevent bacterial biofilm as well as are compatible to cells when compared to hydrophobic surfaces. Coating PU with PANi and PANi+AgNp renders the surface conductive, suggesting potential application in electrochemical biosensors. In addition, these modifications make the surface more biocompatible than the original PU.     

Multivariate analysis of combined Raman and fibre‐optic reflectance spectra for the identification of binder materials in simulated medieval paints

The non‐invasive identification of paint materials used in works of art is essential, both for preserving and restoring them, and also for understanding and verifying the history surrounding their creation. As such, the development of suitable non‐invasive techniques has received much interest in recent years. We have investigated the use of Fourier transform (FT)‐Raman spectroscopy and fibre‐optic reflectance spectroscopy (FORS), together with multivariate principal‐component analysis (PCA) techniques, in order to identify the pigment and binding materials used in made‐up samples representative of real artwork. We demonstrate that both types of spectroscopy provide complementary information which can be used to identify the pigments and binders in paint samples. We show that PCA with FT‐Raman spectra can be used to assist in the identification of oil‐based binders, and that the additional data provided by FORS spectra enables PCA on combined spectra to identify more complex proteinaceious and polysaccharide‐based binding media. The results presented here demonstrate that multivariate analyses of lead‐based paints, using data measured by FT‐Raman and FORS in conjunction, have much potential for identifying individual pigments and binders in paint samples. This provides a path towards computer‐assisted characterisation of paint materials on artwork. Copyright © 2013 John Wiley & Sons, Ltd.