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.     

IUCAA: genesis of a unique research centre

The European Physical Journal H - The Inter-University Centre for Astronomy and Astrophysics (IUCAA) is the second Inter-University Centre established by the Government of India for promotion of...     

Computational and experimental investigations on the effect of crystallinity and crystal size on Na-transport in nanoscaled Si: implications for Si-based anodes for Na-ion batteries

Journal of Solid State Electrochemistry - While Li transport in Si is well understood, little is known about Na transport, despite Si being considered a potential anode material for the upcoming...     

Si-decorated CNT network as negative electrode for lithium-ion battery

Journal of Solid State Electrochemistry - We have developed a method which is adaptable and straightforward for the production of a negative electrode material based on Si/carbon nanotube (Si/CNTs)...     

Modulation of Biophysical Cues in Nature Inspired Patterning of Porous Silk Fibroin Scaffold for Replenishable Controlled Drug Delivery

While a sticking plasteris enough for healing of most of the minor cuts they may get routinely, critical situations like surgical, gunshot, accidental or diabetic wounds;lacarations and other cutaneous deep cuts may require implants and simultaneous medications for healing. From the biophysical standpoint, an internal force-based physical surface stimulusis crucial for cellular sensing during wound repair. In this paper, the authors report the fabrication of a porous, biomimmetically patterned silk fibroin scaffold loaded with ampicillin, which exhibits controlled release of the drug along with possible replenishment of the same. In vitro swelling study reveals that the scaffolds with hierarchical surface patterns exhibit lower swelling and degradation than other types of scaffolds. The scaffolds, that show remarkable broad–spectrum antibacterial efficacy, exhibit Korsemeyer–Peppas model for the ampicillin release patterns due to the structural hydrophobicity imparted by the patterns. Four distinct cell-matrix adhesion regimes are investigated for the fibroblasts to eventually form cell sheets all over the hierarchical surface structures. 4',6–diamidino–2–phenylindole (DAPI) and Fluorescein Diacetate (FDA) fluorescent staining clearly demonstrate the superiority of patterned surface over its other variants. A comparative immunofluorescence study among collagen I, vinculin, and vimentin expressions substantiated the patterned surface to be superior to others.     

Solution to the Riemann problem for drift-flux model with modified Chaplygin two-phase flows

In this paper, we concern about the Riemann problem for compressible no-slip drift-flux model which represents a system of quasi-linear partial differential equations derived by averaging the mass and momentum conservation laws with modified Chaplygin two-phase flows. We obtain the exact solution of Riemann problem by elaborately analyzing characteristic fields and discuss the elementary waves namely, shock wave, rarefaction wave and contact discontinuity wave. By employing the equality of pressure and velocity across the middle characteristic field, two nonlinear algebraic equations with two unknowns as gas density ahead and behind the middle wave are formed. The Newton–Raphson method of two variables is applied to find the unknowns with a series of initial data from the literature. Finally, the exact solution for the physical quantities such as gas density, liquid density, velocity, and pressure are illustrated graphically.