Determination of biomembrane bending moduli in fully atomistic simulations.

The bilayer bending modulus (Kc) is one of the most important physical constants characterizing lipid membranes, but precisely measuring it is a challenge, both experimentally and computationally. Experimental measurements on chemically identical bilayers often differ depending upon the techniques employed, and robust simulation results have previously been limited to coarse-grained models (at varying levels of resolution). This Communication demonstrates the extraction of Kc from fully atomistic molecular dynamics simulations for three different single-component lipid bilayers (DPPC, DOPC, and DOPE). The results agree quantitatively with experiments that measure thermal shape fluctuations in giant unilamellar vesicles. Lipid tilt, twist, and compression moduli are also reported

A New and Facile Route Using Electride Solutions To Intercalate Alkaline Earth Ions into Graphite

A series of new ternary graphite intercalation compounds (GICs) containing alkaline earth metal cations (M = Mg, Ca, Sr, Ba) and ethylenediamine (en) are reported. These GICs are deep blue to green in color and can be prepared as phase-pure compounds by the direct reaction of graphite powder with the metal in liquid en at mild temperatures (25-100 degrees C) under an inert atmosphere. X-ray diffraction and thermal analyses were employed to determine the structural and compositional details. [Mg-2(en)(2.0)] C-26 and [Ba-2(en)(2.0)]C-34 can be obtained as stage-1 GICs with gallery expansions of 0.55 and 0.46 nm, respectively, indicating the presence of intercalate monolayers with en cointercalates oriented perpendicular to the encasing graphene layers. Reactions with Ca and Sr metals form [Ca(en)(2.0)]C-26 and [Sr(en)(2.0)]C-22, which are stage-1 GICs with intercalate bilayers and gallery expansions of 0.76 nm. Titration indicates that each metal intercalate is associated with a 2-electron reduction process. Details on the effects of reaction time, temperature, and starting stoichiometry on reaction rates and product staging are reported

Program Overview and Assessment Methodology for Online Instruction in Chemistry at Oregon State University

Oregon State University offers a wide range of online chemistry courses. The courses are well subscribed, as of 2013 approximately 13% of our department’s student credit hours were awarded in online courses, and both the online enrollment totals and the fraction of effort devoted to online instruction continue to increase. In this article, we describe the program history, provide detailed course offering descriptions, indicate student populations and our program-level assessment plan in the program. Program and course level assessment methodologies include collecting and evaluating both instructor and student feedback, adding learning analytics to course content for chapter and lab-level assessment data, and comparison of formal course outcomes

The Electrochemical Synthesis of the Graphite Intercalation Compounds Containing Tetra-n-alkylammonium Cations

The electrochemical intercalation of tetra-n-alkylammonium (TAA) cations into graphite is investigated using galvanostatic reduction and cyclic voltammetry in TAABr/ dimethylsulfoxide (DMSO) electrolytes. Structural and compositional analyzes by X-ray diffraction, thermogravimetric and elemental analyzes show that stable graphite intercalation compounds (GICs) are formed with highly-flattened TAA cation bilayers for (C₅H₁₁)₄N⁺, (C₆H₁₃)₄N⁺, (C₇H₁₅)₄N⁺, (C₈H₁₇)₄N⁺, with gallery expansions of 0.81 nm. (C₄H₉)₄N⁺ forms a mixed-phase product including a stable GIC with monolayer TAA arrangement and a gallery expansion of 0.48 nm. The GICs with bilayer galleries incorporate 0.7–1.2 DMSO co-intercalate molecules per cation; the monolayer galleries contain relatively little DMSO. Although cyclic voltammetry shows that TAA cations smaller than (C₄H₉)₄N⁺ do intercalate into graphite, they do not form stable GICs. The GICs obtained by galvanostatic reduction are compared to those prepared using chemical ion-exchange reactions. A surface passivation model is introduced to explain the relative stabilities of GICs formed with larger TAA cation intercalates

Quantum Phase and Quantum Phase Operators: Some Physics and Some History

After reviewing the role of phase in quantum mechanics, I discuss, with the aid of a number of unpublished documents, the development of quantum phase operators in the 1960's. Interwoven in the discussion are the critical physics questions of the field: Are there (unique) quantum phase operators and are there quantum systems which can determine their nature? I conclude with a critique of recent proposals which have shed new light on the problem.Comment: 19 pages, 2 Figs. taken from published articles, LaTeX, to be published in Physica Scripta, Los Alamos preprint LA-UR-92-352

Comment on Higgs Inflation and Naturalness

We rebut the recent claim (arXiv:0912.5463) that Einstein-frame scattering in the Higgs inflation model is unitary above the cut-off energy Lambda ~ Mp/xi. We show explicitly how unitarity problems arise in both the Einstein and Jordan frames of the theory. In a covariant gauge they arise from non-minimal Higgs self-couplings, which cannot be removed by field redefinitions because the target space is not flat. In unitary gauge, where there is only a single scalar which can be redefined to achieve canonical kinetic terms, the unitarity problems arise through non-minimal Higgs-gauge couplings.Comment: 5 pages, 1 figure V3: Journal Versio

Drag in paired electron-hole layers

We investigate transresistance effects in electron-hole double layer systems with an excitonic condensate. Our theory is based on the use of a minimum dissipation premise to fix the current carried by the condensate. We find that the drag resistance jumps discontinuously at the condensation temperature and diverges as the temperature approaches zero.Comment: 12 pages, 1 Figure, .eps file attache

AR2, a novel automatic muscle artifact reduction software method for ictal EEG interpretation: Validation and comparison of performance with commercially available software.

Objective: To develop a novel software method (AR2) for reducing muscle contamination of ictal scalp electroencephalogram (EEG), and validate this method on the basis of its performance in comparison to a commercially available software method (AR1) to accurately depict seizure-onset location. Methods: A blinded investigation used 23 EEG recordings of seizures from 8 patients. Each recording was uninterpretable with digital filtering because of muscle artifact and processed using AR1 and AR2 and reviewed by 26 EEG specialists. EEG readers assessed seizure-onset time, lateralization, and region, and specified confidence for each determination. The two methods were validated on the basis of the number of readers able to render assignments, confidence, the intra-class correlation (ICC), and agreement with other clinical findings. Results: Among the 23 seizures, two-thirds of the readers were able to delineate seizure-onset time in 10 of 23 using AR1, and 15 of 23 using AR2 (

Intravesical rAd-IFNα/Syn3 for Patients With High-Grade, Bacillus Calmette-Guerin-Refractory or Relapsed Non-Muscle-Invasive Bladder Cancer: A Phase II Randomized Study.

Purpose Many patients with high-risk non-muscle-invasive bladder cancer (NMIBC) are either refractory to bacillus Calmette-Guerin (BCG) treatment or may experience disease relapse. We assessed the efficacy and safety of recombinant adenovirus interferon alfa with Syn3 (rAd-IFNα/Syn3), a replication-deficient recombinant adenovirus gene transfer vector, for patients with high-grade (HG) BCG-refractory or relapsed NMIBC. Methods In this open-label, multicenter (n = 13), parallel-arm, phase II study ( ClinicalTrials.gov identifier: NCT01687244), 43 patients with HG BCG-refractory or relapsed NMIBC received intravesical rAd-IFNα/Syn3 (randomly assigned 1:1 to 1 × 10(11) viral particles (vp)/mL or 3 × 10(11) vp/mL). Patients who responded at months 3, 6, and 9 were retreated at months 4, 7, and 10. The primary end point was 12-month HG recurrence-free survival (RFS). All patients who received at least one dose were included in efficacy and safety analyses. Results Forty patients received rAd-IFNα/Syn3 (1 × 10(11) vp/mL, n = 21; 3 × 10(11) vp/mL, n = 19) between November 5, 2012, and April 8, 2015. Fourteen patients (35.0%; 90% CI, 22.6% to 49.2%) remained free of HG recurrence 12 months after initial treatment. Comparable 12-month HG RFS was noted for both doses. Of these 14 patients, two experienced recurrence at 21 and 28 months, respectively, after treatment initiation, and one died as a result of an upper tract tumor at 17 months without a recurrence. rAd-IFNα/Syn3 was well tolerated; no grade four or five adverse events (AEs) occurred, and no patient discontinued treatment because of an adverse event. The most frequently reported drug-related AEs were micturition urgency (n = 16; 40%), dysuria (n = 16; 40%), fatigue (n = 13; 32.5%), pollakiuria (n = 11; 28%), and hematuria and nocturia (n = 10 each; 25%). Conclusion rAd-IFNα/Syn3 was well tolerated. It demonstrated promising efficacy for patients with HG NMIBC after BCG therapy who were unable or unwilling to undergo radical cystectomy