The mechanism of Cd2+ block of Ca2+ currents (ICa) was explored in squid neurons using whole-cell patch clamp. Control currents activated sigmoidally, more rapidly at more positive potentials, and did not inactivate significantly. External Cd2+ up to 250 microM reduced ICa reversibly. For small depolarizations, the current for a step of 10 ms increased to a maintained value, resembling the cont...

background: the purpose of this study was to evaluate the fallopian tube of women with infertility and to observe whether there are any significant differences in the hysterosalpingogram findings with regard to prevalence of tubal block in women with primary and secondary infertility. methods: a retrospective study of unilateral and bilateral tubal obstruction in hysterosalpingogram of women wi...

Organic pollutants (e.g. polyaromatic hydrocarbons (PAH)) strongly sorb to carbonaceous sorbents such as black carbon and activated carbon (BC and AC, respectively). For a creosote-contaminated soil (Sigma15PAH 5500 mg kg(dry weight(dw))(-1)) and an urban soil with moderate PAH content (Sigma15PAH 38 mg kg(dw)(-1)), total organic carbon-water distribution coefficients (K(TOC)) were up to a fact...

Reversible blockage of the voltage-dependent anion channel (VDAC) of the mitochondrial outer membrane by dimeric tubulin is being recognized as a potent regulator of mitochondrial respiration. The tubulin-blocked state of VDAC is impermeant for ATP but only partially closed for small ions. This residual conductance allows studying the nature of the tubulin-blocked state in single-channel recons...

A current hypothesis for the pathology of Alzheimer's disease (AD) proposes that amyloid-β (Aβ) peptides induce uncontrolled, neurotoxic ion flux across cellular membranes. The mechanism of ion flux is not fully understood because no experiment-based Aβ channel structures at atomic resolution are currently available (only a few polymorphic states have been predicted by computational models). St...

Design, synthesis, and study of a synthetic barrel-stave supramolecule with p-octiphenyl "staves," beta-sheet "hoops," and hydrophobic exterior as well as internal carboxylate clusters are reported. Ion transport experiments indicate the formation of transmembrane pores at 5 < pH < 7 with nanomolar activity. Blockage of dye efflux from spherical bilayers by external Mg(OAc)(2) and internal 8-am...

Hexylene-bridged periodic mesoporous polysilsesquioxanes (HBPMS) are a promising new class of adsorbent for the removal of organic contaminants from aqueous solutions. These hybrid organic-inorganic materials have a larger BET surface area of 897 m2·g-1 accessible through a cubic, isotropic network of 3.82-nm diameter pores. The hexylene bridging group provides enhanced adsorption of organic mo...