a nanocomposite membrane cu2+ ion-selective electrode has been constructed using a new compound ethyl 1,2,3,4-tetrahydro-4-(4-methoxyphenyl)-6-methyl-2-oxopyrimidine-5-carboxylat (etmoc) as a neutral ionophore. the electrode works properly. it responds to cu2+ ion with a sensitivity of 29.5 ± 0.2 mv/decade over the range 1.0 × 10−9 to 5.0 × 10−1m at ph 3.0-8.0. the limit of detection was 4.5 × ...

60 Garden Street, Cambridge, Massachusetts 02138 (March 1, 1999) About fifty years ago two important papers appeared describing novel interactions. One, by Casimir, discussed the case of two interacting walls [1] and the other, by Casimir and Polder, considered the interactions between an atom and a wall and between two atoms [2]. The history and some of the many interesting aspects of these in...

The interaction of ions with interfaces and, in particular, the high specificity of these interactions to the particular ions considered, are central questions in the field of surface forces. Here we study the effect of different salts (NaI, NaCl, CaCl₂ and MgCl₂) on monolayers made of cholesterol molecules, both experimentally (surface area vs. lateral pressure isotherms measured by a Langmuir...

The hydration interaction is responsible for the colloidal stability observed in protein-coated particles at high ionic strengths. The origin of this non-DLVO interaction is related not only to the local structure of the water molecules located at the surface but also to the structure of those molecules involved in the hydration of the ions that surround the colloidal particles. Ruckenstein and...

Co2VO4 with Co tetrahedrons and octahedrons of transition metal oxides has achieved progress in electrocatalysts batteries. However, high metal-metal interactions make it challenging to maintain reactivity as well increase the conductivity stability supercapacitors. In this work, spinel-structured CoZn0.5V1.5O4 a specific surface area was synthesized through an ion-exchange process from metal-o...

Electrostatic forces, acting between helices and modulated by the presence of the ion atmosphere, are key determinants in the energetic balance that governs RNA folding. Previous studies have employed Poisson-Boltzmann (PB) theory to compute the energetic contribution of these forces in RNA folding. However, the complex interaction of these electrostatic forces with RNA features such as tertiar...

The interaction between nanoparticles and biomolecules such as protein andDNA is one of the major instructions of nanobiotechnology research. In this study,we have explored the interaction of adenine nucleic base with a representativegolden cluster (Au13) by using dispersion corrected density functional theory(DFT-D3) within GGA-PBE model of theory. Various active sites ...

ion channels are naturally occurring pores through the proteins that regulate the passage of ions and thus maintain the concentration of ions inside and outside the cell. the ion channels control many physiological functions and they can show selectivity for a specific ion. ion channels are mostly observed in nerve cells and muscle cells. the influx of ions into cells can be regulated by a gate...

The large electrostatic repulsion arising from the negatively charged backbone of RNA molecules presents a large barrier to folding. Solution counterions assist in the folding process by screening this electrostatic repulsion. While early research interpreted the effect of these counterions in terms of an empirical ligand-binding model, theories based on physical models have supplanted them and...

In close interaction with photoreceptors, the retinal pigment epithelium (RPE) plays an essential role for visual function. The analysis of RPE functions, specifically ion channel functions, provides a basis to understand many degenerative diseases of the retina. The invention of the patch-clamp technique significantly improved the knowledge of ion channel structure and function, which enabled ...