Synthesis and Structural Studies of 6-（2,5-Dimethyl-1H-pyrrol-1-yl）pyridin-2-amine

6-(2,5-Dimethyl-1H-pyrrol-1-yl)pyridin-2-amine (1) was synthesized and characte-rized by elemental analyses,1H-NMR and 13C-NMR,FTIR,Uv-Vis,mass spectral studies and single-crystal X-ray diffraction.All data obtained from spectral studies support the structural properties of 1.Intermolecular N-H…N hydrogen bonds produce an R22(8) ring.An extensive three-dimensional network formed by C-H…π and N-H…π-facial hydrogen bonds is responsible for the crystal stabilization.The combination of C-H…π interactions produces R33(12),R43(19) and R44(20) rings.     

Swelling of <Emphasis Type="Italic">N</Emphasis>-vinylcaprolactam-dodecyl methacrylate gel in {heptane + toluene} mixtures

A copolymer gel has been synthesized from N-vinylcaprolactam and dodecyl methacrylate in ethanol using the free radical cross-linking polymerization method. Characterizations of the gel were performed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA) techniques. Swelling behavior of the gel was investigated in heptane, toluene, and their binary mixtures with different compositions. Swelling value in toluene is higher than that in heptane and swelling value increases with the increasing initial content of toluene in the binary mixture with heptane. The swelling values are correlated by the first- and second-order differential equations, and the best model correlating the experimental results is a second-order one. Diffusion coefficients have also been calculated for heptane and toluene at each concentration by power-law and first-order equations. While the diffusion mechanism of the gel in heptane is a Fickian one, the gel swelled in toluene exhibits a non-Fickian character. Diffusion mechanisms of the gels in binary mixtures are much more complicated. Because of the higher swelling degree in toluene compared to that in heptane, selectivity of the gel in different {heptane + toluene} mixtures with selectivity close to 1 has also been taken into consideration.     

Centri-voltammetry for biosensing systems: biocentri-voltammetric xanthine detection

Centri-voltammetry is a method that combines centrifugation and voltammetry. This method, developed by our group in 2003, yielded promising results when applied to trace analysis of metal ios. We demonstrate here the first application of centri-voltammetry to biosensing systems. A xanthine biosensor was constructed by immobilizing xanthine oxidase on a planar platinum electrode which then was placed at the bottom of a centri-voltammetric cell. The experimental parameters were optimized to give two linear ranges. The first is from 0.1 to 1???M, and the second from 5 to 50???M. The RSD is 3.4 (n?=?5). The biosensor was applied to the determination of xanthine in wine and in urine. Calculated recoveries are 101?±?0.61% (n?=?3) for wine samples, and 102?±?0.556% (n?=?3) for urine samples.

Live Cell Imaging With Biocompatible Fluorescent Carbon Quantum Dots Derived From Edible Mushrooms Agaricus bisporus,Pleurotus ostreatus,and Suillus luteus

In the study, fluorescent imaging of live cells was performed using fluorescent carbon quantum dots derived from edible mushrooms species; Agaricus bisporus, Pleurotus ostreatus, and Suillus luteus as a fluorophore agent. Carbon quantum dots were synthesized through a facile and low-cost method based on microwave irradiation of dried mushroom samples in hydrogen peroxide solution under optimized conditions (microwave energy, solution type, duration of microwave treatment, amount of mushroom). Upon purification with centrifugation, microfiltration, and dialysis, the lyophilized carbon quantum dots were identified through UV–visible, fluorescence and FT-IR, X-ray photoelectron spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy, and quantum yield calculation. Cell viability assessment of the carbon quantum dots was evaluated against human epithelial cell line PNT1A using the Alamar Blue Assay. In vitro fluorescence cell imaging studies demonstrated that the carbon dots could dynamically penetrate the cell membrane and nuclear membrane and localize in both the cytoplasm and the nucleus.

     

The investigation of 0<Superscript>+</Superscript> ↔ 0<Superscript>−</Superscript><Emphasis Type="Italic">β</Emphasis> decay in some spherical nuclei

The 0⁺ ↔ 0⁻ first-forbidden β decay transitions have been investigated for some spherical nuclei. The theoretical framework is based on a proton-neutron quasiparticle random phase approximation (pnQRPA). The Woods-Saxon potential basis has been used in our calculations. The transition probabilities have been calculated within the ξ approximation. The relativistic β moment matrix element has been calculated both directly without any assumption and assuming that it is proportional to the non-relativistic one.     

Soft set theory and uni–int decision making

We firstly redefine the operations of Molodtsov’s soft sets to make them more functional for improving several new results. We also define products of soft sets and uni–int decision function. By using these new definitions we then construct an uni–int decision making method which selects a set of optimum elements from the alternatives. We finally present an example which shows that the method can be successfully applied to many problems that contain uncertainties.     

Optimal ship navigation with safety distance and realistic turn constraints

We consider the optimal ship navigation problem wherein the goal is to find the shortest path between two given coordinates in the presence of obstacles subject to safety distance and turn-radius constraints. These obstacles can be debris, rock formations, small islands, ice blocks, other ships, or even an entire coastline. We present a graph-theoretic solution on an appropriately-weighted directed graph representation of the navigation area obtained via 8-adjacency integer lattice discretization and utilization of the A^∗ algorithm. We explicitly account for the following three conditions as part of the turn-radius constraints: (1) the ship’s left and right turn radii are different, (2) ship’s speed reduces while turning, and (3) the ship needs to navigate a certain minimum number of lattice edges along a straight line before making any turns. The last constraint ensures that the navigation area can be discretized at any desired resolution. Once the optimal (discrete) path is determined, we smoothen it to emulate the actual navigation of the ship. We illustrate our methodology on an ice navigation example involving a 100,000 DWT merchant ship and present a proof-of-concept by simulating the ship’s path in a full-mission ship handling simulator.     

Potential of mean force calculations of ligand binding to ion channels from Jarzynski's equality and umbrella sampling

Potential of mean force (PMF) calculations provide a reliable method for determination of the absolute binding free energies for protein-ligand systems. The common method used for this purpose -- umbrella sampling with weighted histogram analysis -- is computationally very laborious, which limits its applications. Recently, a much simpler alternative for PMF calculations has become available, namely, using Jarzynski's equality in steered molecular dynamics simulations. So far, there have been a few comparisons of the two methods and mostly in simple systems that do not reflect the complexities of protein-ligand systems. Here, we use both methods to calculate the PMF for ion permeation and ligand binding to ion channels. Comparison of results indicate that Jarzynski's method suffers from relaxation problems in complex systems and would require much longer simulation times to yield reliable PMFs for protein-ligand systems.     

Di- and tetranuclear copper(II) complexes of a novel binucleating tetrathioether-tetrathiol ligand

A novel bi-tetradentate polythioether ligand, 6,6-methylene-bis(5- mercapto-3-thiahexyl)-4,8-dithiaundecane-1, 11-dithiol (H4L) was synthesized, and its di- and tetranuclear copper(II) complexes were prepared, and characterized by elemental analyses, magnetic moments, 1H-n.m.r., i.r., and Uv/vis spectra. The i.r. data show that the ligand acts in a tetradentate manner and coordinates via one S atom of the thioether and thiol groups. The geometry of the metal chelates is discussed with the help of magnetic and spectroscopic measurements. The elemental analyses, stoichiometry, and spectroscopic data of the complexes indicate that the copper(II) ions are coordinated to the bi-dianion of the ligand. The function of the thiol ligand is to release protons to form copper(II) complexes, (Cu2L).