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Full-Text Articles in Physics
Protein Conformational Entropy Is Not Slaved To Water, Bryan S Marques, Matthew A Stetz, Christine Jorge, Kathleen G Valentine, A Joshua Wand, Nathaniel V Nucci
Protein Conformational Entropy Is Not Slaved To Water, Bryan S Marques, Matthew A Stetz, Christine Jorge, Kathleen G Valentine, A Joshua Wand, Nathaniel V Nucci
Faculty Scholarship for the College of Science & Mathematics
Conformational entropy can be an important element of the thermodynamics of protein functions such as the binding of ligands. The observed role for conformational entropy in modulating molecular recognition by proteins is in opposition to an often-invoked theory for the interaction of protein molecules with solvent water. The "solvent slaving" model predicts that protein motion is strongly coupled to various aspects of water such as bulk solvent viscosity and local hydration shell dynamics. Changes in conformational entropy are manifested in alterations of fast internal side chain motion that is detectable by NMR relaxation. We show here that the fast-internal side …
Comparative Study Of Silk-Based Magnetic Materials: Effect Of Magnetic Particle Types On The Protein Structure And Biomaterial Properties., Ye Xue, Samuel Lofland, Xiao Hu
Comparative Study Of Silk-Based Magnetic Materials: Effect Of Magnetic Particle Types On The Protein Structure And Biomaterial Properties., Ye Xue, Samuel Lofland, Xiao Hu
Faculty Scholarship for the College of Science & Mathematics
This study investigates combining the good biocompatibility and flexibility of silk protein with three types of widely used magnetic nanoparticles to comparatively explore their structures, properties and potential applications in the sustainability and biomaterial fields. The secondary structure of silk protein was quantitatively studied by infrared spectroscopy. It was found that magnetite (Fe3O4) and barium hexaferrite (BaFe12O19) can prohibit β-sheet crystal due to strong coordination bonding between Fe3+ ions and carboxylate ions on silk fibroin chains where cobalt particles showed minimal effect. This was confirmed by thermal analysis, where a high temperature degradation peak was found above 640 °C in …
Divergence Of The Dielectric Constant In Ultrathin Granular Metal Films Near The Percolation Threshold, H. Bakkali, E. Blanco, Samuel Lofland, M. Dominguez
Divergence Of The Dielectric Constant In Ultrathin Granular Metal Films Near The Percolation Threshold, H. Bakkali, E. Blanco, Samuel Lofland, M. Dominguez
Faculty Scholarship for the College of Science & Mathematics
We report on the electronic and optical properties of ultrathin granular films. We demonstrate that the static dielectric constant increases with thickness in the dielectric regime and diverges at the critical thickness, as predicted by classical percolation theory. However, for thicker samples, the dc conductivity does not obey scaling laws due to the presence of tunneling conduction. In this region the dielectric constant is positive, and the electronic transport is not metallic but can be described by Jonscher's universal power law, even though there is a Drude-like response indicating the presence of free charge carriers. Only for thicker films when …
In Situ Electric-Field Study Of Surface Effects In Domain Engineered Pb(In1/2nb1/2)O3-Pb(Mg1/3nb2/3)O3-Pbtio3 Relaxor Crystals By Grazing Incidence Diffraction, Markys G. Cain, Margo Staruch, Paul Thompson, Christopher Lucas, Didier Wermeille, Yves Kayser, Burkhard Beckhoff, Samuel Lofland, Peter Finkel
In Situ Electric-Field Study Of Surface Effects In Domain Engineered Pb(In1/2nb1/2)O3-Pb(Mg1/3nb2/3)O3-Pbtio3 Relaxor Crystals By Grazing Incidence Diffraction, Markys G. Cain, Margo Staruch, Paul Thompson, Christopher Lucas, Didier Wermeille, Yves Kayser, Burkhard Beckhoff, Samuel Lofland, Peter Finkel
Faculty Scholarship for the College of Science & Mathematics
In this work, we present a grazing incidence X-ray diffraction study of the surface of a 0.24Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) [011] poled rhombohedral single crystal. The near surface microstructure (the top several tens to hundreds of unit cells) was measured in situ under an applied electric field. The strains calculated from the change in lattice parameters have been compared to the macroscopic strain measured with a strain gauge affixed to the sample surface. The depth dependence of the electrostrain at the crystal surface was investigated as a function of temperature. The analysis revealed hidden sweet spots featuring unusually high strains that were …
Protein And Polysaccharide-Based Fiber Materials Generated From Ionic Liquids: A Review., Christopher R Gough, Ashley Rivera-Galletti, Darrel A Cowan, David Salas-De La Cruz, Xiao Hu
Protein And Polysaccharide-Based Fiber Materials Generated From Ionic Liquids: A Review., Christopher R Gough, Ashley Rivera-Galletti, Darrel A Cowan, David Salas-De La Cruz, Xiao Hu
Faculty Scholarship for the College of Science & Mathematics
Natural biomacromolecules such as structural proteins and polysaccharides are composed of the basic building blocks of life: amino acids and carbohydrates. Understanding their molecular structure, self-assembly and interaction in solvents such as ionic liquids (ILs) is critical for unleashing a flora of new materials, revolutionizing the way we fabricate multi-structural and multi-functional systems with tunable physicochemical properties. Ionic liquids are superior to organic solvents because they do not produce unwanted by-products and are considered green substitutes because of their reusability. In addition, they will significantly improve the miscibility of biopolymers with other materials while maintaining the mechanical properties of the …
The Impact Of Composition And Morphology On Ionic Conductivity Of Silk/Cellulose Bio-Composites Fabricated From Ionic Liquid And Varying Percentages Of Coagulation Agents., Bailey Blessing, Cory Trout, Abneris Morales, Karleena Rybacki, Stacy A Love, Guillaume Lamoureux, Sean M O'Malley, Xiao Hu, David Salas-De La Cruz
The Impact Of Composition And Morphology On Ionic Conductivity Of Silk/Cellulose Bio-Composites Fabricated From Ionic Liquid And Varying Percentages Of Coagulation Agents., Bailey Blessing, Cory Trout, Abneris Morales, Karleena Rybacki, Stacy A Love, Guillaume Lamoureux, Sean M O'Malley, Xiao Hu, David Salas-De La Cruz
Faculty Scholarship for the College of Science & Mathematics
Blended biocomposites created from the electrostatic and hydrophobic interactions between polysaccharides and structural proteins exhibit useful and unique properties. However, engineering these biopolymers into applicable forms is challenging due to the coupling of the material’s physicochemical properties to its morphology, and the undertaking that comes with controlling this. In this particular study, numerous properties of the Bombyx mori silk and microcrystalline cellulose biocomposites blended using ionic liquid and regenerated with various coagulation agents were investigated. Specifically, the relationship between the composition of polysaccharide-protein bio-electrolyte membranes and the resulting morphology and ionic conductivity is explored using numerous characterization techniques, including scanning …
Recent Advances In Electrospun Sustainable Composites For Biomedical, Environmental, Energy, And Packaging Applications., Hao Liu, Christopher R Gough, Qianqian Deng, Zhenggui Gu, Fang Wang, Xiao Hu
Recent Advances In Electrospun Sustainable Composites For Biomedical, Environmental, Energy, And Packaging Applications., Hao Liu, Christopher R Gough, Qianqian Deng, Zhenggui Gu, Fang Wang, Xiao Hu
Faculty Scholarship for the College of Science & Mathematics
Electrospinning has gained constant enthusiasm and wide interest as a novel sustainable material processing technique due to its ease of operation and wide adaptability for fabricating eco-friendly fibers on a nanoscale. In addition, the device working parameters, spinning solution properties, and the environmental factors can have a significant effect on the fibers' morphology during electrospinning. This review summarizes the newly developed principles and influence factors for electrospinning technology in the past five years, including these factors' interactions with the electrospinning mechanism as well as its most recent applications of electrospun natural or sustainable composite materials in biology, environmental protection, energy, …
Electrospun Silk-Boron Nitride Nanofibers With Tunable Structure And Properties., Ye Xue, Xiao Hu
Electrospun Silk-Boron Nitride Nanofibers With Tunable Structure And Properties., Ye Xue, Xiao Hu
Faculty Scholarship for the College of Science & Mathematics
In this study, hexagonal boron nitride (h-BN) nanosheets and Bombyx mori silk fibroin (SF) proteins were combined and electrospun into BNSF nanofibers with different ratios. It was found that the surface morphology and crosslinking density of the nanofibers can be tuned through the mixing ratios. Fourier transform infrared spectroscopy study showed that pure SF electrospun fibers were dominated by random coils and they gradually became α-helical structures with increasing h-BN nanosheet content, which indicates that the structure of the nanofiber material is tunable. Thermal stability of electrospun BNSF nanofibers were largely improved by the good thermal stability of BN, and …
Framework For The Natures Of Negativity In Introductory Physics, Suzanne White Brahmia, Alexis Olsho, Trevor Smith, Andrew Boudreaux
Framework For The Natures Of Negativity In Introductory Physics, Suzanne White Brahmia, Alexis Olsho, Trevor Smith, Andrew Boudreaux
Faculty Scholarship for the College of Science & Mathematics
Mathematical reasoning skills are a desired outcome of many introductory physics courses, particularly calculus-based physics courses. Novices can struggle to understand the many roles signed numbers play in physics contexts, and recent evidence shows that unresolved struggle can carry over to subsequent physics courses. Positive and negative quantities are ubiquitous in physics, and the sign carries important and varied meanings. The mathematics education research literature documents the cognitive challenge of conceptualizing negative numbers as mathematical objects—both for experts, historically, and for novices as they learn. We contribute to the small but growing body of research in physics contexts that examines …
Protein-Polysaccharide Composite Materials: Fabrication And Applications., Elizabeth J Bealer, Shola Onissema-Karimu, Ashley Rivera-Galletti, Maura Francis, Jason Wilkowski, David Salas-De La Cruz, Xiao Hu
Protein-Polysaccharide Composite Materials: Fabrication And Applications., Elizabeth J Bealer, Shola Onissema-Karimu, Ashley Rivera-Galletti, Maura Francis, Jason Wilkowski, David Salas-De La Cruz, Xiao Hu
Faculty Scholarship for the College of Science & Mathematics
Protein-polysaccharide composites have been known to show a wide range of applications in biomedical and green chemical fields. These composites have been fabricated into a variety of forms, such as films, fibers, particles, and gels, dependent upon their specific applications. Post treatments of these composites, such as enhancing chemical and physical changes, have been shown to favorably alter their structure and properties, allowing for specificity of medical treatments. Protein-polysaccharide composite materials introduce many opportunities to improve biological functions and contemporary technological functions. Current applications involving the replication of artificial tissues in tissue regeneration, wound therapy, effective drug delivery systems, and …
Quantitatively Ranking Incorrect Responses To Multiple-Choice Questions Using Item Response Theory, Trevor Smith, Kyle J. Louis, Bartholemew J. Ricci Iv, Nasrine Bendjilali
Quantitatively Ranking Incorrect Responses To Multiple-Choice Questions Using Item Response Theory, Trevor Smith, Kyle J. Louis, Bartholemew J. Ricci Iv, Nasrine Bendjilali
Faculty Scholarship for the College of Science & Mathematics
Research-based assessment instruments (RBAIs) are ubiquitous throughout both physics instruction and physics education research. The vast majority of analyses involving student responses to RBAI questions have focused on whether or not a student selects correct answers and using correctness to measure growth. This approach often undervalues the rich information that may be obtained by examining students’ particular choices of incorrect answers. In the present study, we aim to reveal some of this valuable information by quantitatively determining the relative correctness of various incorrect responses. To accomplish this, we propose an assumption that allows us to define relative correctness: students who …