Weak interactions: Potency for stabilization of molecule in solid state

Weak interactions usually show a versatile property to stabilize the molecular conformation and crystal packing in solid state. Crystal packing and conformational property of the synthesized compound 1(3‐cyano‐4,6‐dimethyl nicotinonitril‐1‐yl)‐3‐(phalimido‐1‐yl)‐1‐thioxyethane ( 2 ) is stabilized by CH···O, CH···N, and CH···π interactions. J. Heterocyclic Chem., 00 , 00 (2011).     

Optimization of corona discharge process using Box–Behnken design of experiments

The corona discharge process was studied using Box–Behnken design of experiments in conjunction with response surface methodology of analysis. The single as well as interaction effects of process factors namely applied voltage, time of charging, and distance between electrodes on the surface potential of meltblown nonwoven electret media were examined. The response surface model predicting the surface potential of the electrets displayed a very good correspondence with the experimental results. The optimized corona discharge process run by keeping the predicted levels of process factors yielded surface potential of the electret media very close to that predicted from the model.     

D-branes inpp-wave background

We show the existence of classical solutions ofD-branes as well as a system ofD3-branes oriented at an arbitrary angle with respect to each other, in a six-dimensionalpp-wave background obtained fromAdS ₃ × S³ ×R ⁴ , withR — R andNS — NS 3-from flux. The world volume coordinate of D5-brane lies along the six-dimensional pp-wave directions, whereas thepp-wave direction is transverse to the system of D3-branes. We also present moreD-brane bound state solutions by applyingT-duality symmetries. The system ofD3-branes oriented at an arbitrary angle is shown to preserve 1/16 supersymmetries. Finally a brief discussion of the open string construction is presented for both the cases.     

Study of a class of models for self-organization: equilibrium analysis

A new class of nonlinear stochastic models is introduced with a view to explore self-organization. The model consists of an assembly of anharmonic oscillators, interacting via a mean field of system size range, in presence of white, Gaussian noise. Its properties are explored in the overdamped regime (Smoluchowski limit). The single oscillator potential is such that for small oscillator displacements it leads to a highly nonlinear force but becomes asymptotically harmonic. The shape of the potential can be a single-or double-well and is controlled by a set of parameters. Through equilibrium statistical mechanical analysis, we study the collective behavior and the nature of phase transition. Much of the analysis is analytic and exact. The treatment is not restricted to the thermodynamic limit so that we are also able to discuss finite size effects in the model.     

Development of 1-(4-(Substituted)piperazin-1-yl)-2-((2-((4-methoxybenzyl)thio)pyrimidin-4-yl)oxy)ethanones That Target Poly (ADP-Ribose) Polymerase in Human Breast Cancer Cells

A number of uracil amides cleave poly (ADP-ribose) polymerase and therefore novel thiouracil amide compounds were synthesized and screened for the loss of cell viability in a human-estrogen-receptor-positive breast cancer cell line. The synthesized compounds exhibited moderate to significant efficacy against human breast cancer cells, where the compound 5e IC₅₀ value was found to be 18 μM. Thouracil amide compounds 5a and 5e inhibited the catalytical activity of PARP1, enhanced cleavage of PARP1, enhanced phosphorylation of H2AX, and increased CASPASE 3/7 activity. Finally, in silico analysis demonstrated that compound 5e interacted with PARP1. Hence, specific thiouracil amides may serve as new drug-seeds for the development of PARP inhibitors for use in oncology.     

Effect of Polymer and Surfactant‐Polymer Couples on the Acid-Catalyzed Hydrolysis of Phenyl Urea

The mechanism of the hydrolysis decomposition of phenyl urea in acid, polymer, and surfactant‐polymer media was investigated, the addition‐elimination mechanism with rate determining attack of water at N‐protonated substrate having already been studied. This study has introduced the polymer PEG (MW‐400) and (surfactant‐polymer) (ceteyl trimethyl ammonium bromide‐poly ethylene glycol) (CTAB‐PEG), (cetyl pyridinium bromide‐polyethylene glycol) (CPC‐PEG) (sodium dodecyl sulphate‐poly ethylene glycol) (SDS‐PEG), (Triton X‐100‐poly ethylene glycol) (TX‐100‐PEG), and (Brij35‐poly ethylene glycol) (Brij35‐PEG) in acid media. The results indicate that the presence of polymer and surfactant‐polymer enhances the rate of reaction at 80°C in the presence of 0.9 M H₂SO₄. Kinetic studies show that the reaction obeyed first‐order kinetics. The reaction kinetics can be well explained by micellar catalysis models like the PPIE.     

Supramolecular Barrel-Rosette Ion Channel Based on 3,5-Diaminobenzoic Acid for Cation-Anion Symport

The structural tropology and functions of natural cation-anion symporting channels have been continuously investigated due to their crucial role in regulating various physiological functions. To understand the physiological functions of the natural symporter channels, it is vital to develop small-molecule-based biomimicking systems that can provide mechanistic insights into the ion-binding sites and the ion-translocation pathways. Herein, we report a series of bis((R)-(−)-mandelic acid)-linked 3,5-diaminobenzoic acid based self-assembled ion channels with distinctive ion transport ability. Ion transport experiment across the lipid bilayer membrane revealed that compound 1 b exhibits the highest transport activity among the series, and it has interesting selective co-transporting functions, i.e., facilitates K⁺/ClO₄⁻ symport. Electrophysiology experiments confirmed the formation of supramolecular ion channels with an average diameter of 6.2±1 Å and single channel conductance of 57.3±1.9 pS. Selectivity studies of channel 1 b in a bilayer lipid membrane demonstrated a permeability ratio of , , and indicating the higher selectivity of the channel towards KClO₄ over KCl salt. A hexameric assembly of a trimeric rosette of 1 b was subjected to molecular dynamics simulations with different salts to understand the supramolecular channel formation and ion selectivity pattern.     

Anisotropic fluctuations in ordered copolymer phases

The random phase approximation is reformulated to investigate the anisotropic fluctuations about an ordered polymer phase. This very general method is applied to the lamellar phase of block copolymers. The calculated anisotropic scattering intensity captures the main features observed experimentally including the secondary peaks due to fluctuations with hexagonal symmetry. We also determined the limits of metastability of the lamellar phase as well as the bending and elastic moduli of the lamellae.