objective(s): the structure- activity relationship of a series of 36 molecules, showing l-type calcium channel blocking was studied using a qsar (quantitative structure–activity relationship) method. materials and methods: structures were optimized by the semi-empirical am1 quantum-chemical method which was also used to find structure-calcium channel blocking activity trends. several types of d...

water alternating gas (wag) technique is used in the petroleum industry to inject carbon dioxide (co2) into underground formations either for sequestration or enhanced oil recovery (eor) processes. co2 injection causes reactions with formation brine or aquifer and produces carbonic acid, the acid dissolves calcite and changes flow behavior significantly. modeling and investigating effects of co...

residual gas saturation is one of the most important parameter in determining recovery factor of water-drive gas reservoir. visual observation of processes occurring at the pore level in micromodels can give an insight to fluid displacements at the larger scale and also help the interpretation of production performance at reservoir scale. in this study experimental tests in a glass micromodel w...

Many pathogens utilize the formation of transmembrane pores in target cells in the process of infection. A great number of pore-forming proteins, both bacterial and viral, are considered to be important virulence factors, which makes them attractive targets for the discovery of new therapeutic agents. Our research is based on the idea that compounds designed to block the pores can inhibit the a...

We have investigated the reduction of steady state sodium channel currents by a monovalent and a divalent guanidinium analogue. The amount of block by the divalent compound at a constant membrane potential was dramatically reduced by an increase in the internal salt concentration. Channel block by the monovalent molecule was a less steep function of salt concentration. These results would be ex...

Voltage-gated K(+) (Kv) channel activation depends on interactions between voltage sensors and an intracellular activation gate that controls access to a central pore cavity. Here, we hypothesize that this gate is additionally responsible for closed-state inactivation (CSI) in Kv4.x channels. These Kv channels undergo CSI by a mechanism that is still poorly understood. To test the hypothesis, w...

INTRODUCTION In our previous study, we found that negatively charged gold nanoparticles with spermidine have the potential of blocking inwardly rectifying potassium channels (Kir), both at the cellular and the tissue level. METHODS For the purpose of the present study, we purified the cytoplasmic domain of the Kir 3.1 receptor from Escherichia coli. Using single particles with surface coating...

This study compared membrane fouling in a sponge-submerged membrane bioreactor (SSMBR) and a conventional membrane bioreactor (CMBR) based on sludge properties when treating synthetic domestic wastewater. In the CMBR, soluble microbial products (SMP) in activated sludge were a major contributor for initial membrane fouling and presented higher concentration in membrane cake layer. Afterwards, m...

Each species from bacteria to human has a distinct genetic fingerprint. Therefore, a mechanism that detects a single molecule of DNA represents the ultimate analytical tool. As a first step in the development of such a tool, we have explored using a nanometer-diameter pore, sputtered in a nanometer-thick inorganic membrane with a tightly focused electron beam, as a transducer that detects singl...

Polyamines block the retinal cyclic nucleotide-gated channel from both the intracellular and extracellular sides. The voltage-dependent mechanism by which intracellular polyamines inhibit the channel current is complex: as membrane voltage is increased in the presence of polyamines, current inhibition is not monotonic, but exhibits a pronounced damped undulation. To understand the blocking mech...