Antimicrobial Nitric Oxide Releasing Creams/Devices Based on a Novel Reaction Between S-Nitrosoglutathione and Zinc Oxide Nanoparticles

In recent years, a small diatomic free radical gas molecule known as nitric oxide (NO) has gained much attention by the biomedical community due to its potential use as a therapeutic agent. In this dissertation, a NO donor (S-Nitrosoglutathione (GSNO)) is incorporated into newly devised NO releasing topical creams to potentially treat wound or skin infections, and within novel NO releasing insert devices for disinfecting the hub region of tunnel dialysis catheters (TDCs). GSNO is used throughout this research because it is an endogenous carrier of NO in the human body and is therefore likely to be non-toxic for potential biomedical applications. In Chapter 2, GSNO is shown to be stabilized when mixed in Vaseline and stored under dry conditions for 300+ days. Also, it is demonstrated that a commercial ZnO-containing cream, when combined with the GSNO in Vaseline mixture, enhances the NO release rate from GSNO. In Chapter 3, the antimicrobial effects of the NO releasing creams are shown to exhibit significant antimicrobial activity versus S. aureus, S. epidermidis, and P. aeruginosa. A NO releasing cream modified by the addition of NaHCO3 to achieve a neutral pH cream also exhibits similar antimicrobial effects. In Chapter 4, solution phase studies reveal that ZnO is the primary component responsible in the commercial ZnO cream for the enhanced NO release rate from GSNO. Further studies show that 30 nm size ZnO nanoparticles increase NO release rate by a factor of 2.78 compared to no ZnO present. Surface analysis of ZnO suggests no evidence of Zn-S bond formation or thiol attachment after interaction with GSNO. In Chapter 5, a NO releasing insert device is introduced as an innovative method to disinfect the hub region of TDCs. A short-term shelf-life stability study shows minimal GSNO degradation within the insert device after 56 d of dry/dark storage after H2O2 sterilization. Once wetted up by soaking in saline solution, the NO releasing insert device exhibits significant antimicrobial effects against S. aureus and P. aeruginosa present in the liquid of catheter hubs. Two 14 d long sheep studies demonstrate that the NO releasing insert device is exceptionally potent at preventing bacteria/biofilm growth on the inner lumen walls of the catheters compared normal caps and a chlorhexidine cap. Significant achievements showcased in this thesis include creation of potent antimicrobial NO releasing creams, discovery of increased NO release from GSNO using ZnO nanoparticles, and creation of NO releasing insert devices capable of preventing bacteria and biofilm growth in catheters. The NO releasing creams provide an attractive alternative method to antibiotic creams to treat dermal infections. The NO releasing insert devices have the potential to significantly lower the number of infections caused by TDCs and other intravascular catheters.PHDChemistryUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/163025/1/joshdov_1.pd

A nuclear magnetic resonance study of deuterated poly(vinylidene fluoride) and a copolymer of deuterated vinylidene fluoride and tetrafluoroethylene

Pulsed deuterium NMR experiments have been performed on deuterated samples of poly(vinylidene fluoride), PVF(,2), repeat unit CH(,2)CF(,2) and the copolymer poly(vinylidene fluoride)-tetrafluoroethylene (80-20), (PVF(,2)-F(,4)E). A deuterium line shape study has been employed to characterize the orientational distribution of the dipole moments in both poled and unpoled samples. In addition, the orientational distributions of chain axis alignment has been measured in stretched samples.;PVF(,2) and PVF(,2)-F(,4)E exhibit unique piezoelectric and pyroelectric properties which are due to their crystalline components (approximately 50% in typical material). Four crystalline phases exist in the homopolymer PVF(,2), the (alpha), (beta), (gamma), and the (delta). The relatively electrically inactive, melt solidified (alpha) phase can be transformed into the ferroelectric (beta) phase by mechanical deformation (stretching) or by application of large electric fields (poling- 200 Mv/meter). The copolymer melt solidifies directly into the (beta) phase. The (beta) phase is characterized by a net dipole moment per unit cell due to the parallel alignment of the CF(,2) dipole moments in the unit cell. The orthorhombic unit cell dimensions of the (beta) phase render a nearly pseudohexagonal packing structure of the molecular chains and is thought to allow for dipole reorientations via 60(DEGREES) steps during the poling process.;The orientationally dependent quadrupole interaction has been used to characterize the orientational distributions of the molecular dipole moments about the poling direction in both poled and unpoled samples of PVF(,2) and PVF(,2)-F(,4)E. No orientational dependence was found in either the poled or unpoled samples. This is in contrast to recent x-ray results which report substantial orientational anisotropy in rolled, poled protonated films. We have also measured the degree of chain axis alignment in stretched samples of both PVF(,2) and PVF(,2)-F(,4)E. Alignment in both samples is characterized by a gaussian distribution function about the stretch direction with a half width 1/e maximum of 22(DEGREES) and 18(DEGREES) respectively.;The characterization of the experimental results was done by comparing computer simulated line shapes with the experimental line shapes

Introduction to the Special Issue on Policing: Examining the Role of Testing and Assessment

Prepared in response to the weight and seriousness of social concerns with regard to the state and future of policing, this special issue was developed in order to feature research that examined a wide range of personnel and assessment decisions relating to policing. The focus was broad in scope, welcoming conceptual/theoretical papers, quantitative or qualitative reviews, empirical papers, and think pieces. To address the questions and areas identified in the initial call for papers, six articles are presented covering the themes of individual differences in personnel selection group composition and macro-level influences on policing, and practical recommendations and the future of policing. It is our expectation that these manuscripts will serve as a wellspring for further discussion and consideration of the role of psychology and assessment in improving police departments

Predicting the impacts on residential property values from changes in water quality

Eutrophication is the accelerated aging process of a lake which generally decreases the water quality in terms of aesthetic and recreational uses. At Liberty Lake, near Spokane, Washington, eutrophication has become a problem. Many individuals and agencies are interested in the benefits that occur when the lake's water quality has improved. In this research the benefits to private property owners were measured at Liberty Lake. Three methods — present sales, appraised value and personal interview — were compared and empirically tested to determine the economic benefits to private property owners as well as the overall community impact. For this study property was defined as land, buildings and other improvements. Current market sales and appraised values at six different lakes, each with different water quality levels, were used as the dependent variables for the present sales and appraised value methods. The dependent variables were regressed against several factors including physical (.housing, neighborhood, accessibility, and environmental characteristics) to estimate the effect water quality had on property values. A quadratic and double logarithmic function were examined. In the results a positive relationship was found between water quality and the dependent variables. A 100 percent increase in the water quality ranking resulted in a $3,800 increase in the sales price per lot and$884 increase in the appraised value per lot for the quadratic function. Separate equations were determined for vacant lots. The dependent variables were the same, but only neighborhood, accessibility and environmental characteristics were used to estimate the effect water quality had on property values. In the quadratic form with a 100 percent increase in the water quality ranking, sales price increased $556 per lot and appraised value increased$782 per lot. In the personal interview method home owners at Liberty Lake were interviewed and asked for how much they would be willing to buy and sell a particular home at different water quality levels. The differences between the two buying and selling prices were the estimated impact of a change in water quality and totaled $4,795 and$5,679, respectively. Both differences were significant at the one percent level. The buying price difference was used when comparing the personal interview method to the other methods, since it was less likely to overestimate the water quality effect. This research used the best water quality index available, but there is a definite need for future research to develop a uniform water quality index

Negative ion detachment cross sections

During past year, we have measured cross sections for associative and collisional detachment for several negative ions in collisions with atomic hydrogen. Additional experiments have been performed in which the formation of secondary negative ions and electrons by means of low energy ion impact on surfaces has been studied. Brief descriptions of these activities along with future plans for the project follow

An Evaluation of a STEM Program for Middle School Students on Learning Disability Related IEPs

A year long Science, Technology, Engineering and Math (STEM) program was developed for middle schools students on Individualized Education Programs (IEPs) involving learning disabilities. The workshops were designed to encourage students both on IEPs and not on IEPs to explore STEM as a future career choice by building their knowledge and confidence. The participants in the workshops included 11 students on IEPs and 15 students not on IEPs. Parents also provided feedback regarding their attitudes toward the program. The results indicated that there were increases in student participant knowledge and career interest for both the students not on IEPs and the students on IEPs. Overall, reactions to the program from both students and parents were quite positive

High School Bridge Program: A Multidisciplinary STEM Research Program

A Science, Technology, Engineering and Math (STEM) summer Bridge Program was developed for high school students. The program was designed to encourage students to consider choosing an engineering major in college and to explore STEM as a future career. This was accomplished through a 10-week program involving multidisciplinary research activities. The participants in the program included 33 high school students. Among former participants in position to make a choice in terms of attending college, 100% had chosen to continue on in college, and 86% had chosen to major in a STEM area. The results indicated that that the program had enhanced their confidence in STEM and motivated them in choosing careers in STEM areas. Overall, the participants were very positive about the program and expressed appreciation for the opportunity

Fundamental processes in low energy collisions of alkali anions and atoms

Negative ion sources often employ alkali metal atoms in one way or another in order to increase their yield. Models which describe equilibrium conditions or the nature of energy transport within these sources require, among other things, information about the two-body cross sections for various scattering channels which involve either alkali negative ions or alkali atoms. The purpose of this report is to provide a brief summary of recent experimental observations in which collisions of alkali anions (M/sup -/) with various atoms and molecules and collisions of H/sup -/ and D/sup -/ with alkali atoms (M) have been investigated. The energy range of the experiments, 5 < E < 500 eV, includes those kinetics energies often found in discharge-type ion sources. The specific experiments which will be discussed focus upon measurements of total cross sections for collisional electron detachment and charge transfer of negative ions. 16 refs., 7 figs