An ?-uniform hybrid scheme for singularly perturbed delay differential equations

In this paper, a singularly perturbed delay differential equation of first order has been considered. The problem is solved by using a hybrid scheme on a Shishkin mesh. The difference scheme is shown to converge to the continuous solution uniformly with respect to the perturbation parameter. Truncation errors are obtained. Finally, numerical experiments are carried out on a test problem, confirming the effectiveness of the proposed technique.     

Anion‐Mediated Effects on the Size and Mechanical Properties of Enzymatically Crosslinked Suckerin Hydrogels

The suckerin family of proteins, identified from the squid sucker ring teeth assembly, offers unique mechanical properties and potential advantages over other natural biomaterials. In this study, a small suckerin isoform, suckerin‐12, is used to create enzymatically crosslinked, macro‐scale hydrogels. Upon exposure to specific salt conditions, suckerin‐12 hydrogels contracted into a condensed state where mechanical properties are found to be modulated by the salt anion present. The rate of contraction is found to correlate well with the kosmotropic arm of the Hofmeister anion series. However, the observed changes in hydrogel mechanical properties are better explained by the ability of the salt to neutralize charges in suckerin‐12 by deprotonization or charge screening. Thus, by altering the anions in the condensing salt solution, it is possible to tune the mechanical properties of suckerin‐12 hydrogels. The potential for suckerins to add new properties to materials based on naturally‐derived proteins is highlighted.     

First stereoselective total synthesis of decytospolides A and B

The first synthesis of bioactive decytospolides A and B adopting an oxa-Michael addition as the key step is reported.     

Ultrasound-assisted preparation and characterization of crystalline cellulose-ionic liquid blend polymeric material: a prelude to the study of its application toward the effective adsorption of chromium

The molecular interaction of biopolymers with an array of substrates offers interesting insight into the adsorption phenomenon. The present work proposes the preparation and characterization of cellulose-methyltrioctylammonium chloride (MeTOACl)-a room temperature ionic liquid (IL) blend polymeric sorbent and its application for the adsorption of carcinogenic chromium(VI). The blend adsorbent material was synthesized in a relatively green solvent (methylisobutylketone) medium by ultrasonication. The mechanism of interaction of biopolymer with the ionic liquid could be conceptualized as electrostatic attraction, hydrogen bonding, and Van der Waals force of attraction with the hydroxyl groups of cellulose as a bilayer assembly. The composition, crystallinity, and the surface area of the prepared material were comprehensively characterized using FT-IR, solid-state (13)C NMR, TGA, XRD, SEM, EDX, XPS, and BET isotherm study. The adsorption capacity of chromium(VI) calculated from Langmuir isotherm model was found to be 38.94 mg g(-1) with adherence to the second-order kinetics. The study of thermodynamic parameters that affect the sorption process indicated the spontaneity and exothermic nature of adsorption. The green aspect in the methodology is brought out in the regeneration of the adsorbent, where Cr(VI) could be effectively reduced to the less toxic Cr(III) using ascorbic acid.     

Thiacalix[4]arene based fluorescent probe for sensing and imaging of Fe3+ ions

A thiacalix[4]arene based fluorescent chemosensor 3 in the cone conformation has been synthesized and its recognition behaviour is evaluated toward various metal ions in mixed aqueous media. The chemosensor 3 showed high selectivity towards Fe(3+) ions by fluorescence quenching of excimer emission. Further, evaluation of the 3·Fe(3+) complex prepared in situ demonstrated great promise for the detection of the Fe(3+) ion in the presence of amino acids, blood serum and bovine serum albumin (BSA) solution. The compound 3 has suitable permeability into the PC3 cells and can be utilized as a Fe(3+) selective sensor in living cells (PC3 cells).     

HPTLC Quantification and Antimicrobial Activity of Ursolic Acid from Diospyros melanoxylon

JPC – Journal of Planar Chromatography – Modern TLC - An important bioactive molecule, ursolic acid was isolated from the leaves of Diospyros melanoxylon and characterized with help of...     

Formation of a tris-capsule and a tris-carceplex from a cyclic six-bowl assembly

A macrocycle composed of six cavitands was assembled into a tris-capsule and a tris-carceplex, each of which encapsulates three guest molecules.