Anticarcinogenic and Antioxidant Action of an Edible Aquatic Flora Jussiaea repens L. Using In Vitro Bioassays and In Vivo Zebrafish Model

Oxidative stress is the major cause of many health conditions, and regular consumption of antioxidants helped to encounter and prevent such oxidative stress-related diseases. Due to safety concerns over long-term uses of synthetic antioxidants, natural antioxidants are more preferred. The purpose of this study is to investigate the antioxidant and anticancer activities of Jussiaea repens L., a wild edible flora found in Manipur, India. The antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), Ferric reducing antioxidant power (FRAP) assay and DNA-nicking assay. The anticancer activity was tested using five cancer lines viz., SKOV3 cells (ovarian), HeLa (cervical), MDA-MB-231 (breast), PANC-1 (pancreatic), and PC3 (prostate). The toxicity, developmental effect, antiproliferative activity was further tested using zebrafish embryos. The methanolic plant extract had higher polyphenol content than flavonoids. The in vitro study demonstrated a promising antioxidant capacity and DNA protection ability of this plant. The extract also showed cytotoxic activity against SKOV3, HeLa, MDA-MB-23, and PANC-1 cancer cell lines. The in vivo studies on zebrafish embryos demonstrated the extract’s ability to suppress the developmental process and elicited more cytotoxicity to cancer cells than developing zebrafish embryos. Moreover, the in vivo studies on zebrafish embryos also indicated the antiproliferative activity of J. repens L. extract.     

Phenylboronic Acid Appended Pyrene‐Based Low‐Molecular‐Weight Injectable Hydrogel: Glucose‐Stimulated Insulin Release

A pyrene‐containing phenylboronic acid (PBA) functionalized low‐molecular‐weight hydrogelator was synthesized with the aim to develop glucose‐sensitive insulin release. The gelator showed the solvent imbibing ability in aqueous buffer solutions of pH values, ranging from 8–12, whereas the sodium salt of the gelator formed a hydrogel at physiological pH 7.4 with a minimum gelation concentration (MGC) of 5 mg mL^?1. The aggregation behavior of this thermoreversible hydrogel was studied by using microscopic and spectroscopic techniques, including transmission electron microscopy, FTIR, UV/Vis, luminescence, and CD spectroscopy. These investigations revealed that hydrogen bonding, π–π stacking, and van der Waals interactions are the key factors for the self‐assembled gelation. The diol‐sensitive PBA part and the pyrene unit in the gelator were judiciously used in fluorimetric sensing of minute amounts of glucose at physiological pH. The morphological change of the gel due to addition of glucose was investigated by scanning electron microscopy, which denoted the glucose‐responsive swelling of the hydrogel. A rheological study indicated the loss of the rigidity of the native gel in the presence of glucose. Hence, the glucose‐induced swelling of the hydrogel was exploited in the controlled release of insulin from the hydrogel. The insulin‐loaded hydrogel showed thixotropic self‐recovery property, which hoisted it as an injectable soft composite. Encouragingly, the gelator was found to be compatible with HeLa cells.     

The Calderón problem for variable coefficients nonlocal elliptic operators

In this paper, we introduce an inverse problem of a Schrödinger type variable nonlocal elliptic operator (???(A(x)?))^s+q), for 0<s<1. We determine the unknown bounded potential q from the exterior partial measurements associated with the nonlocal Dirichlet-to-Neumann map for any dimension n≥2. Our results generalize the recent initiative [18 Ghosh, T., Salo, M., Uhlmann, G. (2016). The Calderón problem for the fractional Schrödinger equation. arXiv preprint arXiv:1609.09248. [Google Scholar]] of introducing and solving inverse problem for fractional Schrödinger operator ((?Δ)^s+q) for 0<s<1. We also prove some regularity results of the direct problem corresponding to the variable coefficients fractional differential operator and the associated degenerate elliptic operator.     

Biomolecule induced nanoparticle aggregation: effect of particle size on interparticle coupling

Gold nanoparticles of variable sizes have been prepared by reducing HAuCl(4) with trisodium citrate by Frens' method. It has been found that the gold particles under consideration produce well-ordered aggregates upon interaction with a biomolecule, glutathione in variable acidic pH condition and exhibit pronounced changes in their optical properties arising due to electromagnetic interaction in the close-packed assembly. The effect of nanoparticle size on the nature of aggregation as well as the variation in the optical response due to variable degree of interparticle coupling effects amongst the gold particles have been investigated. The optical properties of the gold aggregates have been accounted in the light of Maxwell-Garnett effective medium theory considering the changes in the filling factor in different aggregates produced by variable sizes of gold colloids. The aggregates have been characterized by UV-vis spectroscopy, FTIR, Raman, XRD and TEM studies. It has been observed that a new peak appearing at a longer wavelength intensifies and shifts further to the red from the original peak position depends on the particle size, concentration of glutathione and pH of the solution. On the basis of the first appearance of a clearly defined new peak at longer wavelength, a higher sensitivity of glutathione detection has been achieved with gold nanoparticles of larger dimension.     

Phenol- and catechol-based ruthenium(II) polypyridyl complexes as colorimetric sensors for fluoride ions

We report two ruthenium(II) polypyridyl complexes with pendant phenol/catechol functionality that act as colorimetric sensors for fluoride ions. Experiments have revealed that hydrogen bond formation occurs with a slight excess of fluoride ion. However, in higher [F-], deprotonation of the O-H functionality resulted. Time-dependent (TD-DFT) calculations at the B3LYP/LANL2DZ level have shown that new bands appear at longer wavelengths upon complexation with fluoride ions. These are of mixed character, MLCT (dpi(Ru)-->pi*(L1/bpy)), and intra- and interligand [pi(L1)-->pi*(bpy) and pi(L1)-->pi*(L1)] transitions. These complexes also act as sensors for fluoride ions in solvent-water mixtures.     

PHYSICS INFORMED NEURAL NETWORKS (PINNs) FOR APPROXIMATING NONLINEAR DISPERSIVE PDEs

We propose a novel algorithm,based on physics-informed neural networks (PINNs) to efficiently approximate solutions of nonlinear dispersive PDEs such as the KdV-Kawahara,Camassa-Holm and Benjamin-Ono equations.The stability of solutions of these dispersive PDEs is leveraged to prove rigorous bounds on the resulting error.We present several numerical experiments to demonstrate that PINNs can approximate solutions of these dispersive PDEs very accurately.     

Higher order finite difference schemes for the magnetic induction equations

We describe high order accurate and stable finite difference schemes for the initial-boundary value problem associated with the magnetic induction equations. These equations model the evolution of a magnetic field due to a given velocity field. The finite difference schemes are based on Summation by Parts (SBP) operators for spatial derivatives and a Simultaneous Approximation Term (SAT) technique for imposing boundary conditions. We present various numerical experiments that demonstrate both the stability as well as high order of accuracy of the schemes.      

Self-assembly of silver nanoparticles: synthesis, stabilization, optical properties, and application in surface-enhanced Raman scattering

Silver nanoparticle aggregates were synthesized in large scale using resorcinol under alkaline condition to obtain an assembly of silver clusters. Stable dispersion of the cluster in aqueous medium has been examined out of resorcinol-capped silver nanoparticle assemblies. The UV-vis spectroscopy during the particle evolution has been studied in detail. From the high-resolution TEM (HRTEM) image and XRD pattern it was confirmed that the particles are made of pure silver only. The capping action of resorcinol has been authenticated from the FTIR spectra. UV-vis spectroscopy and TEM images reveal that the temperature, effect of vibrational energy, heat shock, and time-dependent particle evolution have unique bearing on the stability and surface properties of the clusters. The concentrations of silver nitrate, resorcinol, and NaOH have important influence on the particle evolution and its size. TEM images incite us to examine the aggregates to capitulate surface-enhanced Raman scattering (SERS) to the single molecular level using crystal violet (CV) and cresyl fast violet (CFV) as molecular probes. The SERS intensity of CV increases with increasing the size of the silver aggregate.     

Branching random walks,stable point processes and regular variation

Using the theory of regular variation, we give a sufficient condition for a point process to be in the superposition domain of attraction of a strictly stable point process. This sufficient condition is used to obtain the weak limit of a sequence of point processes induced by a branching random walk with jointly regularly varying displacements. Because of heavy tails of the step size distribution, we can invoke a one large jump principle at the level of point processes to give an explicit representation of the limiting point process. As a consequence, we extend the main result of Durrett (1983) and verify that two related predictions of Brunet and Derrida (2011) remain valid for this model.