5 research outputs found

    Ion-Specific Induced Fluctuations and Free Energetics of Aqueous Protein Hydrophobic Interfaces: Toward Connecting to Specific-Ion Behaviors at Aqueous Liquid–Vapor Interfaces

    No full text
    We explore anion-induced interface fluctuations near protein–water interfaces using coarse-grained representations of interfaces as proposed by Willard and Chandler (J. Phys. Chem. B 2010, 114, 1954−1958). We use umbrella sampling molecular dynamics to compute potentials of mean force along a reaction coordinate bridging the state where the anion is fully solvated and one where it is biased via harmonic restraints to remain at the protein–water interface. Specifically, we focus on fluctuations of an interface between water and a hydrophobic region of hydrophobin-II (HFBII), a 71 amino acid residue protein expressed by filamentous fungi and known for its ability to form hydrophobically mediated self-assemblies at interfaces such as a water/air interface. We consider the anions chloride and iodide that have been shown previously by simulations as displaying specific-ion behaviors at aqueous liquid–vapor interfaces. We find that as in the case of a pure liquid–vapor interface, at the hydrophobic protein–water interface, the larger, less charge-dense iodide anion displays a marginal interfacial stability compared with that of the smaller, more charge-dense chloride anion. Furthermore, consistent with the results at aqueous liquid–vapor interfaces, we find that iodide induces larger fluctuations of the protein–water interface than chloride

    H-Atom Position as Pattern-Determining Factor in Arenethiol Films

    No full text
    The evolution of a low coverage of benzenethiol molecules on Cu(111) during annealing shows the prevalence of S···H hydrogen bonds involving hydrogen atoms in the ortho position. The row and pattern formation of (methylated) anthracenethiols indicates intermolecular interactions in which hydrogen atoms at the terminal position of the aromatic moiety dominate. In combination, this leads to the notion that pattern formation in classes of arenethiol molecules is each governed by optimization of the intermolecular interactions of the hydrogen atom at one particular position on the arene. This may provide a general guiding principle for the design of arenethiol films

    H-Atom Position as Pattern-Determining Factor in Arenethiol Films

    No full text
    The evolution of a low coverage of benzenethiol molecules on Cu(111) during annealing shows the prevalence of S···H hydrogen bonds involving hydrogen atoms in the ortho position. The row and pattern formation of (methylated) anthracenethiols indicates intermolecular interactions in which hydrogen atoms at the terminal position of the aromatic moiety dominate. In combination, this leads to the notion that pattern formation in classes of arenethiol molecules is each governed by optimization of the intermolecular interactions of the hydrogen atom at one particular position on the arene. This may provide a general guiding principle for the design of arenethiol films

    Clinical progression of ocular injury following arsenical vesicant lewisite exposure

    No full text
    <p>Ocular injury by lewisite (LEW), a potential chemical warfare and terrorist agent, results in edema of eyelids, inflammation, massive corneal necrosis and blindness. To enable screening of effective therapeutics to treat ocular injury from LEW, useful clinically-relevant endpoints are essential. Hence, we designed an efficient exposure system capable of exposing up to six New-Zealand white rabbits at one time, and assessed LEW vapor-induced progression of clinical ocular lesions mainly in the cornea. The right eye of each rabbit was exposed to LEW (0.2 mg/L) vapor for 2.5, 5.0, 7.5 and 10.0 min and clinical progression of injury was observed for 28 days post-exposure (dose–response study), or exposed to same LEW dose for 2.5 and 7.5 min and clinical progression of injury was observed for up to 56 days post-exposure (time–response study); left eye served as an unexposed control. Increasing LEW exposure caused corneal opacity within 6 h post-exposure, which increased up to 3 days, slightly reduced thereafter till 3 weeks, and again increased thereafter. LEW-induced corneal ulceration peaked at 1 day post-exposure and its increase thereafter was observed in phases. LEW exposure induced neovascularization starting at 7 days which peaked at 22–35 days post-exposure, and remained persistent thereafter. In addition, LEW exposure caused corneal thickness, iris redness, and redness and swelling of the conjunctiva. Together, these findings provide clinical sequelae of ocular injury following LEW exposure and for the first time establish clinically-relevant quantitative endpoints, to enable the further identification of histopathological and molecular events involved in LEW-induced ocular injury.</p
    corecore