37th Annual WKU Student Research Conference

Western Kentucky University 38th Annual Student Research Conference program and student abstracts. Saturday, April 12, 2008, Carroll Knicely Conference Center, Bowling Green, Kentucky

Factors Affecting the Outcomes in Bilateral Total Knee Arthroplasty: A Case Report

The purpose of this case study was to determine the effects of femoral nerve block use during total knee arthroplasty on the return of quadriceps activation and functional outcomes in a single patient. This case study focused on an individual case consisting of simultaneous bilateral knee replacement. The individual received a femoral nerve block in one knee and traditional anesthesia in the other. We considered the improvement in functional outcomes following surgery. It was expected that the femoral nerve block will delay the activation of the quadriceps muscle and the return of functional measures. However, the femoral nerve block will modulate pain more successfully compared to the standard pain control procedures. This case study will also address the effect of femoral nerve blocks on quadriceps, particularly Vastus Medialis Oblique, reactivation following TKA. If so, for how long is quadriceps activation delayed. Is return of balance and proprioceptive control delayed following use of a femoral nerve block during TKA

The plug-based nanovolume Microcapillary Protein Crystallization System (MPCS)

The Microcapillary Protein Crystallization System (MPCS) is a new protein-crystallization technology used to generate nanolitre-sized crystallization experiments for crystal screening and optimization. Using the MPCS, diffraction-ready crystals were grown in the plastic MPCS CrystalCard and were used to solve the structure of methionine-R-sulfoxide reductase

Superconducting properties and Hall Effect of epitaxial NbN thin films

We have measured the magnetotransport properties and Hall effect of a series of epitaxial NbN films grown on (100) oriented single crystalline MgO substrate under different conditions using reactive magnetron sputtering. Hall effect measurements reveal that the carrier density in NbN thin films is sensitive to the growth condition. The carrier density increases by a factor of 3 between the film with highest normal state resistivity (rho_n~3.83micro-Ohm-m) and lowest transition temperature (Tc~9.99K) and the film with lowest normal state resistivity (rho_n~0.94micro-Ohm-m) and highest transition temperature (Tc~16.11K) while the mobility of carriers does not change significantly except for the most resistive films. Our results show that the Tc of NbN is governed primarily by the carrier density rather than disorder scattering. By varying the carrier concentration during growth we can vary the effective disorder (kF_l) from the moderately clean limit to the dirty limit which makes this system ideal to study the interplay of carrier density and disorder on the superconducting properties of an s-wave superconductor.Comment: ps files with figures (accepted for publication in Phys. Rev. B

Effect of machining velocity on the crystallographic textures in a diamond turned aluminium single crystal

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Hydrocarbon chain conformation in an intercalated surfactant monolayer and bilayer

Cetyl trimethyl ammonium (CTA) ions have been confined within galleries of layered CdPS3 at two different grafting densities. Low grafting densities are obtained on direct intercalation of CTA ions into CdPS3 to give Cd0.93PS3(CTA)0.14. Intercalation occurs with a lattice expansion of 4.8 Å with the interlamellar surfactant ion lying flat forming a monolayer. Intercalation at higher grafting densities was effected by a two-step ion-exchange process to give Cd0.83PS3(CTA)0.34, with a lattice expansion of 26.5 Å. At higher grafting densities the interlamellar surfactant ions adopt a tilted bilayer structure. 13C NMR and orientation-dependent IR vibrational spectroscopy on single crystals have been used to probe the conformation and orientation of the methylene 'tail' of the intercalated surfactant in the two phases. In the monolayer phase, the confined methylene chain adopts an essentially all-trans conformation with most of the trans chain aligned parallel to the gallery walls. On lowering the temperature, molecular plane aligns parallel, so that the methylene chain lies flat, rigid and aligned to the confining surface. In the bilayer phase, most bonds in the methylene chain are in trans conformation. It is possible to identify specific conformational sequences containing a gauche bond, in the interior and termini of the intercalated methylene. These high energy conformers disappear on cooling leaving all fifteen methylene units of the intercalated cetyl trimethyl ammonium ion in trans conformational registry at 40 K

Scalable Nano Particle Production of Low Bioavailability Pharmaceuticals for Augmented Aqueous Solubility

The billion dollar pharmaceutical research and development pipeline suffers greatly from high attrition rates of novel therapeutic compounds within pre-clinical and clinical trials. Poor bioavailability in many new drugs, originating in the various methodologies of high throughput screening, may explain part of these growing failure rates. One interpretation of this phenomenon relies on bioavailability\u27s correlation with aqueous solubility; much modern processing allows chemicals to fully develop without touching water, yielding upwards of 90% of new chemical entities practically insoluble in aqueous media. Thus, one approach to alleviating bioavailability and potentially clinical attrition rates necessitates augmented aqueous solubility. The amorphous nanoparticle presents the largest boost in aqueous solubility of a chemical through processing alone. In this contribution, we propose electrospray as a novel, competitive candidate to produce pharmaceutical amorphous nanoparticles with the intent of augmenting solubility. Electrospray represents an idyllic nominee for three reasons: repeatability, flexibility, and scalability. Electrospray offers low batch to batch variation with less than 30% relative standard deviation between various droplets. This triumphs over the several orders of magnitude in variation in pneumatic sprays. Electrospray\u27s flexibility draws from its ability to attain diameters over several orders of magnitude, ranging from hundreds of microns to several nanometers; in this contribution droplets are produced between 500 nm and 1[micro]m. Finally, electrospray displays scalability to any industrial requirement; though a single nozzle operates at mere microliters per hour, a single multiplexed array of emitters may increase this throughput by several orders of magnitude. This exploration, utilizing Indomethacin as a model low solubility chemical, verifies electrospray as a compatible processing tool for the pharmaceutical industry. Scanning electron microscopy coupled with the image analysis software ImageJ gleans the size and shape of emitted (and dried) particles. Amorphicity verification of particles employs grazing angle x-ray diffraction. Finally, ultraviolet and visual spectrum spectroscopy evaluates the solubility advantage of particles