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Characterization of Lamellar Liquid Crystal Emulsifiers in Topical Creams Containing a Novel Solvent
No full textDiethylene glycol monoethyl ether (DEGEE) is a promising solvent component in topical cream formulations due to its superior solubilizing abilities with certain active pharmaceutical ingredients. One of the goals of this study is to characterize the effects of pH on the physical and chemical stabilities of topical cream formulations containing particularly high concentrations of DEGEE by characterizing a full topical pH profile of 3.5 – 9.0. The second goal is to evaluate the presence, amount, and characteristics of lyotropic liquid crystals (LLCs), molecularly structured in a lamellar phase, in a model cream emulsion utilizing polarized light microscopy (PLM). The presence of lamellar structured LLCs has been found to improve the overall character and stability of cream formulations. In this study, it was found that the oil-in-water emulsion is physically stable at pH values under the inflection point. Chemical stability was confirmed by an accelerated temperature condition at 40°C where the pH value was stable throughout the topical profile. The presence and abundance of lamellar LLCs at the oil-water interface were found to be more abundant at pH values below the inflection point. The introduction of thermal studies provided interesting results when lamellar LLCs were heated and slow cooled to ambient conditions. It is possible a different crystalline structure was produced upon cooling the sample; however, continued research is needed to definitively determine these results
Elderly Consumers and Grocery Store Patronage: A Determinant Attribute Model
No full textThe article discusses articles and essays on Missouri in the U.S. Civil War that appeared in the journal from 1977 to 2008. Articles discussed include The Significant Skirmish: The Battle of Boonville, June 17, 1861, by Paul Rorvig, \u27I Acted From Principle\u27: William Marcellus McPheeters, Confederate Surgeon, by Cynthia DeHaven Pitcock and Bill J. Gurley, and \u27 A Friend of the Enemy\u27: Federal Efforts to Suppress Disloyalty in St. Louis During the Civil War, by Louis S. Gerteis. Topics of other articles include the legacy of U.S. President Abraham Lincoln in Missouri, an 1863 raid at Cape Girardeau, Missouri, and the massacre of German Americans by guerrillas on October 10, 1864
Colossal intrinsic exchange bias from interfacial reconstruction in epitaxial CoFe2 O4/Al2 O3 thin films
No full textWe have studied the epitaxial CoFe2O4 (111) films grown on Al2O3 (0001) substrates of different thickness at various temperature and discovered colossal intrinsic exchange bias up to 7 ± 2 kOe. X-ray and electron diffraction clearly indicate an interfacial layer about 2 nm of different crystal structure from the bulk part of the CoFe2O4 film. The thickness dependence of the exchange bias suggests a hidden antiferromagnetic composition in the interfacial layer that couples to the ferrimagnetic bulk part of the CoFe2O4 film as the origin of the exchange bias. Considering the structural, magnetic, and electronic structure, CoO has been identified as the most likely candidate of the antiferromagnetic composition in the interfacial layer. This work suggests a path for enhancing intrinsic exchange bias using combination of film and substrate of large structural differences, highlighting the role of interfacial atomic and electronic reconstructions
Exploring students’ perceptions of identity and helper heuristics in the online classroom discussion board
No full textAlthough applied to numerous communication contexts, affordance approaches have yet to receive sustained attention in the instructional literature. The ongoing migration to online pedagogy suggests a need to examine the impact of technological affordances and communication in Learning Management Systems. To that end, an experimental study investigated the responses of undergraduate students to a course management page, in which the presence or absence of peer identity and the helper heuristic on evaluations of fellow students were manipulated. The results suggest that the helper heuristic—but not identity cues—positively impacted perceptions of source credibility, attractiveness, perceptions of an assignment-related message, and student rapport. Findings are discussed in terms of both theoretical and instructional relevance
Teaching Tennis Footwork Techniques in School Physical Education
No full textThe purpose of this article is to present a content map and sequenced learning tasks to teach tennis footwork techniques in a physical education setting
Discovery of an olivine-type lithium manganese thiophosphate, LiMnPS, a building block approach
No full textAn olivine-type orthothiophospate LiMnPS has been synthesized for the first time through a building block approach by reacting preformed ternary lithium thiophospate with MnCl. Diffuse reflectance measurements show an optical band gap of 2.36 eV, which is further confirmed by DFT calculations. Irreversible weak ferromagnetic ordering and metamagnetism are verified through preliminary magnetic measurements
Life, Love, and Loss: Redefining the Trauma
No full textThis thesis begins with a critical introduction analyzing the use of defamiliarization and the Dostoevskian hero in literature as a catalyst for a change in perception for victims of trauma. I create a relationship between the theories of Viktor Shklovsky and Mikhail Bakhtin as applied to both my own and published works. Short stories from Carmen Maria Machado and Marly Swick and Margaret Atwood’s novel The Handmaid’s Tale help to situate my own writing within this theoretical approach. The basis of my hypothesis lies in the blurred effect that trauma can have on the individual, causing an automatic response to any incidence similar to the primary trauma. The act of defamiliarization grants a perspective toward the initial trauma, breaking the automatic response (Shklovsky) and allowing the recovery process to begin. This new perspective helps the victim to broaden self-consciousness and transforms them from victim to hero (Bakhtin). Literature that defamiliarizes trauma allows a safe vantage point for sufferers and creates a place for recovery
New Solids in As-O-Mo, As(P)-O-Mo(W) and As(P)-O-Nb(W) Systems That Exhibit Nonlinear Optical Properties
No full textInteractions between well-mixed fine powders of As2O3, P2O5, MoO3, WO3 and Nb2O5 at different stoichiometry in quartz ampoules under vacuum at ~1000 °C in the presence of metallic molybdenum (or niobium), over several weeks, led to shiny dichroic crystalline materials being formed in cooler parts of the reaction vessel. An addition of small quantities of metals-Mo or Nb-was made with the aim of partially reducing their highly oxidized Mo(VI), W(VI) or Nb(V) species to corresponding Mo(V), W(V) and Nb(IV) centers, in order to form mixed valence solids. Sublimed crystals of four new compounds were investigated using a variety of techniques, with prime emphasis on the X-ray analysis, followed by spectroscopy (diffusion reflectance, IR, Raman and EPR), second harmonic generation (SHG), thermal analysis under N2 and air atmosphere, and single crystals electrical conductivity studies. The results evidenced the formation of new complex solids of previously unknown compositions and structures. Three out of four compounds crystallized in non-centrosymmetric space groups and represent layered 2D polymeric puckered structures that being stacked on each other form 3D lattices. All new solids exhibit strong second-harmonic-generation (SHG effect; based on YAG 1064 nm tests with detection of 532 nm photons), and a rare photosalient effect when crystals physically move in the laser beam. Single crystals\u27 electrical conductivity of the four new synthesized compounds was measured, and the results showed their semiconductor behavior. Values of band gaps of these new solids were determined using diffusion reflectance spectroscopy in the visible region. Aspects of new solids\u27 practical usefulness are discussed
Global Stability Analysis of a General Model of Zika Virus
No full textMathematical models of Zika virus dynamics are relatively new, and they mostly focus on either vector and horizontal, or vector and vertical transmission only. In this work,we first revisit a recent model that considers vector and vertical transmission, and we provide an alternative proof on the global stability of the disease-free equilibrium point. Then, a new and general model is presented which includes vector, horizontal and vertical transmission. For this new model, existence of both a disease-free and an endemic equilibrium is studied. Using matrix and graph-theoretic methods, appropriate Lyapunov functions are constructed and results on the global stability properties of both equilibria are established
Metal-Free Polymer-Based Affinity Medium for Selective Purification of His6-Tagged Proteins
No full textWe report a metal free synthetic hydrogel copolymer with affinity and selectivity for His6-tagged peptides and proteins. Small libraries of copolymers incorporating charged and hydrophobic functional groups were screened by an iterative process for His6 peptide affinity. The monomer selection was guided by interactions found in the crystal structure of an anti-His tag antibody-His6 peptide antigen complex. Synthetic copolymers incorporating a phenylalanine-derived monomer were found to exhibit strong affinity for both His6-containing peptides and proteins. The proximity of both aromatic and negatively charged functional groups were important factors for the His6 affinity of hydrogel copolymers. His6 affinity was not compromised by the presence of enzyme cleavage sequences. The His6-copolymer interactions are pH sensitive: the copolymer selectively captured His6 peptides at pH 7.8 while the interactions were substantially weakened at pH 8.6. This provided mild conditions for releasing His6-tagged proteins from the copolymer. Finally, a synthetic copolymer coated chromatographic medium was prepared and applied to the purification of a His6-tagged protein from an E. coli expression system. The results establish that a synthetic copolymer-based affinity medium can function as an effective alternative to immobilized metal ion columns for the purification of His6-tagged proteins