This PhD project aimed to investigate the possibility of using Odorant Binding Proteins (OBPs) as sensing layers of chemical sensors, for the detection of organic compounds in both vapour and liquid phases. OBPs are small soluble proteins present in high concentrations in the olfactory system of vertebrates and insects. OBPs are attractive in the biosensor field since they can bind odorants and pheromones in a reversible way. They are resistant to high temperatures and protease activity and they can be easily expressed in large amounts. OBPs belonging to different species of mammals and insects were utilised for developing biosensors relied on different transduction mechanisms. Recombinant OBPs were grafted on the gold electrode of transducers by using Self-assembled monolayers (SAMs) of alkanethiols. The efficiency of the immobilisation method was proved by using electrochemical techniques. Quartz crystal microbalances (QCMs), screen-printed electrodes (SPEs) and interdigitated electrodes (IDEs) were employed for developing three types of OBP-based biosensors. I. QCMs functionalised with OBPs were tested against pheromones (i.e. bombykol and bombykal) and volatile compounds found in foodstuffs (i.e. pyrazine derivatives and geosmin) in vapour phase. The QCM based biosensors showed a good degree of selectivity and a detection limit of the order of parts per billion, in air. II. In liquid phase, impedimetric biosensors based on SPEs also showed a good selectivity and sensitivity being able to detect analyte concentrations of the order of 10-9 M. III. OBPs immobilised on the gold electrodes of IDEs were instead tested against S-(+) carvone vapour, proving that the binding activity of the proteins was preserved in vapour phase and can be quantified as variation of capacitance. The developed OBP biosensors showed good selectivity, sensitivity and stability over time in both liquid and vapour phase. The responses of the sensors were reversible, allowing to the device to be used several times. Moreover, the biosensors were label-free, hence the interaction between OBPs and ligand was directly detected without using auxiliary probes/species. With these findings, we envisage the use of our biosensors in several applications, including monitoring of the quality of food along the transportation and storage, controlling of pests and useful insects in agriculture, or as analytical devices for studying the dynamics in binding processes.

Healthcare associated infections (HAIs) cost the US healthcare system over $45 billion to treat and cause millions of deaths annually. A large subset of HAIs are associated with medical devices that are meant to improve and save lives. Infected devices are treated using traditional antibiotics, contributing to development of antibiotic resistance. Antibiotic resistance is expected to cost $100 trillion and kill more people a year than cancer by 2050; thus, new alternative antimicrobials for the treatment of device-associated HAIs are critically needed. Antimicrobial peptides (AMPs), such as 26 amino-acid (aa), marine-derived Chrysophsin-1 (CHY1), are poised to reduce HAIs due to their broad antimicrobial activity and unique mechanisms of action that do not promote bacterial resistance. AMPs are short (12-50aa), positively charged (+2-+9) proteins found in the innate immune systems of many different species. Their high separation of hydrophilic and hydrophobic residues leads to many unique mechanisms derived from many unique secondary and tertiary structures that are not yet well understood. Despite the discovery of over 2000 natural AMPs and many more synthetically designed AMPs, none have been successfully commercialized for healthcare applications due to challenges surrounding cytotoxicity, short in vivo half-life (degradation), high costs of production and effectiveness in physiological environments (such as those with high-salt). Several strategies have been investigated to overcome these challenges, for example, truncation of cytotoxic sequences or D-amino acid substitution to improve AMP toxicity and stability; however, many of these strategies can reduce antimicrobial effectiveness. A unique strategy of increasing stability, reducing cytotoxicity, and maintaining antimicrobial activity that is relevant for medical devices is the covalent tethering (binding) of AMPs via a flexible tethering molecule to the surface. However, the effect of tethering parameters on resulting AMP mechanisms and activity is still widely debated. AMP activity can vary widely by utilizing different tethering strategies, which include additional variables such as: (1) peptide choice and properties (such as native mechanism, concentration, charge, and structure), (2) tether choice and properties (such as chemical composition, length, charge, surface density, and flexibility), and (3) testing conditions (such as temperature, solvent composition and substrate type). Some studies suggest that AMP performance may be tether-dependent, for example some AMPs require longer tethers while others do not and some need a flexible tether. Thus, models for predicting successful tethering strategies for different AMP properties, which currently do not exist, must be developed. Further, complicated and often destructive techniques, such as XPS and SEM, are typically implemented to study the relationship of all these parameters vs. antimicrobial activity, which are labor-intensive and limited in scope. Predictive models guiding tether strategy need to be constructed, but also new techniques to study tethering be developed. If these technical milestones are achieved they can serve as a predicate for commercial implementation of a host of new therapies targeted at reducing device-associated HAIs. The overall goal of this thesis was to study the relationship between antimicrobial activity of tethered C-CHY1 examining both spacer length and peptide surface density and the development of a feasible clinical business case for tethered AMPs. To achieve this goal, a traditional entrepreneurial approach was taken in which a minimally-viable product was first designed and business case analyzed, followed by studies to better optimize and understand the underlying structure-mechanism relationships. CHY1 with a C-terminus cysteine to allow for surface-binding (C-CHY1) was tethered onto a silicon dioxide surface via a flexible poly(ethylene glycol) (PEG) tether, and then both surface binding behavior and antimicrobial success of C-CHY1 were examined as a function of tether properties and reaction conditions. For these studies, quartz-crystal microbalance with dissipation (QCM-D) was the primary technique, a real-time, non-destructive flow method that was then coupled with downstream characterization techniques: fluorescent microscopy and contact angle measurements. In parallel a deep dive into domestic and international business models for commercializing AMP technologies. Specifically, tether length and surface density effects on C-CHY1 mechanisms were studied, followed by the effect of temperature, type of microbe, and salt concentration on the antimicrobial mechanisms of tethered C-CHY1. QCM-D was used to measure binding of C-CHY1 via three different length tethers, PEG molecular weight (MW) 866, 2000 and 7500, followed by microscopy to measure antimicrobial effectiveness against two model microbes Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Modeling of QCM-D data allowed for surface density and thickness to be calculated and related to C-CHY1 antimicrobial activity. PEG 7500 allowed proper C-CHY1 orientation and mobility, allowing for its native pore-forming mechanism and highest activity while PEG 866 tethers led to denser grafting and an effective, yet non-native ion displacement mechanism. The QCM-D was used to characterize the effect of salt concentration and temperature reaction conditions on the grafting density of C-CHY1 tethered via PEG 866 and PEG 7500, which was then related to antimicrobial activity. For PEG MW 866, neither temperature nor salt concentration increases significantly altered the grafting density of C-CHY1 while for PEG 7500 increasing temperature allowed for significantly increased grafting density. C-CHY1 density had no significant effect on antimicrobial activity against either microbe. Temperature of bacterial incubation did demonstrate microbe-specific changes in C-CHY1 antimicrobial activity. These results demonstrated that small changes in reaction conditions can drastically change membrane selectivity of C-CHY1. An in-depth investigation of the effects of bacterial membrane composition and temperature on soluble C-CHY1 mechanism was implemented to better understand the molecular membrane- and temperature-dependent selectivity and structure-function of C-CHY1. Supported lipid bilayers (SLBs) formed in QCM-D can be used as model membranes to elucidate AMP action mechanisms against membranes of different compositions. Two and three component SLBs representative of Gram-negative phosphatidylethanolamine (PE) and phosphatidyglycerol acid (PG) with and without charged lipopolysaccharide, LPS and Gram-positive bacteria phosphatidylcholine (PC) and PG with and without charged lipoteichoic acid, (LTA) were formed at both 23°C and 37°C. C-CHY1 at 5 µM was exposed to the different membranes and mechanistic surface action was studied. The membranes formed highly different baseline responses in QCM-D, indicative of vastly different membrane structures, thicknesses and deposition behaviors on SiO2, warranting future studies. Further, significant effects of LTA incorporation were observed in both peptide interaction and deposition. There were measurable effects of temperature on membrane formation as well as peptide interaction kinetics and even mode of interaction. Lastly, business models for the commercialization of novel medical device technologies such as surface-tethered C-CHY1 were investigated. While this technology has the potential to solve many unmet needs, there must a commercialization plan implemented in order to have an impact. There is a clear disconnect between technology development in academia and technology commercialization in industry that must be connected. Development of an entrepreneurial mindset at the graduate school level, can help bridge the gap. A thorough investigation of domestic and international business models for commercializing AMP technologies was carried out and distilled in the form of the Business Model Canvas developed by Alexander Osterwalder that can be used as a roadmap for commercialization efforts. Using the QCM-D a relationship between both spacer length and peptide surface density and the antimicrobial activity of tethered C-CHY1 was determined. A business plan was developed in order to increase the impact of this and other AMP based work. This work provides a roadmap for future researchers to quickly develop and commercial novel AMP based coating technology.

Analysis of quartz c-axis fabrics and microstructures from ductily deformed rocks allows for the examination of the kinematics associated with crustal deformation. This thesis expands on the current knowledge of the kinematic evolution of the Himalayas and Scottish Caledonides, by examining samples from the Main Central Thrust (MCT) (Himalayas) and the Sgurr Beag Thrust (SBT) (Scottish Caledonides).  Metamorphic temperatures (Tm) associated above the MCT are inverted; chapter one attempts to test if deformation temperatures (Td) correlate to Tm, indicating that ductile shearing occurred during peak Tm. In the Scottish Caledonides, Td and Tm increase from foreland to hinterland, potentially indicating a right way up thermal structure;  chapter two presents Td and Tm associated with the region around the SBT. Above the MCT, quartz c-axis fabrics yield Td ranging between 500-650 "C, corresponding to the temperatures of dynamic recrystallization for subgrain rotation (SGR) and grain boundary migration (GBM). Up to 1000m above the MCT, Td and Tm are within error of each other, suggesting that shearing occurred during peak Tm; while further away from the MCT  Tm is significantly hotter than Td, suggesting that shearing continued past Tm. Deformation associated with the upper part of the Moine thrust sheet and the SBT yields quartz c-axis fabrics with Td ranging between 395-583 "C, corresponding to the regional dynamic recrystallization. Tm calculations original to this study yield pressure-temperature constraints of 4.8-5.8 kbar and 586-625 "C. Tm is within error of Td, suggesting that deformation and metamorphism were synchronous. / Master of Science

Silica bricks is a refractory building material which contains at least 93 % of silicon dioxide in polymorphic forms, mostly -tridymite, -cristobalite and unreacted -quartz. In glass industry is used for building crowns of glass tanks and in coke industry is used for building coke oven batteries. The advantage is the high refractoriness under load, high resistance to acidic melts. The disadvantage is the low resistance to changes in temperature below 600 °C. The thesis deals with the influence of repeated firing on the silica bricks and to its porous structure and mineralogical composition.

This diploma work is devoted to the preparation and analytical testing of modified gold electrodes in QCM. The sensitivity and selectivity response towards selected aromatic analytes in aqueous phase was monitored. Studied analytes were 1-methylnaphthalene, 2-methylnaphthalene, naphthalene, o-xylene and toluene. These compounds are frequently used in chemistry industry and other industrial branches and, are known to be harmful to human organism and environment. Using QCM method it is possible to detect them rapidly and relatively easily.

Healthcare associated infections (HAIs) cost the US healthcare system over $45 billion to treat and cause millions of deaths annually. A large subset of HAIs are associated with medical devices that are meant to improve and save lives. Infected devices are treated using traditional antibiotics, contributing to development of antibiotic resistance. Antibiotic resistance is expected to cost $100 trillion and kill more people a year than cancer by 2050; thus, new alternative antimicrobials for the treatment of device-associated HAIs are critically needed. Antimicrobial peptides (AMPs), such as 26 amino-acid (aa), marine-derived Chrysophsin-1 (CHY1), are poised to reduce HAIs due to their broad antimicrobial activity and unique mechanisms of action that do not promote bacterial resistance. AMPs are short (12-50aa), positively charged (+2-+9) proteins found in the innate immune systems of many different species. Their high separation of hydrophilic and hydrophobic residues leads to many unique mechanisms derived from many unique secondary and tertiary structures that are not yet well understood. Despite the discovery of over 2000 natural AMPs and many more synthetically designed AMPs, none have been successfully commercialized for healthcare applications due to challenges surrounding cytotoxicity, short in vivo half-life (degradation), high costs of production and effectiveness in physiological environments (such as those with high-salt). Several strategies have been investigated to overcome these challenges, for example, truncation of cytotoxic sequences or D-amino acid substitution to improve AMP toxicity and stability; however, many of these strategies can reduce antimicrobial effectiveness. A unique strategy of increasing stability, reducing cytotoxicity, and maintaining antimicrobial activity that is relevant for medical devices is the covalent tethering (binding) of AMPs via a flexible tethering molecule to the surface. However, the effect of tethering parameters on resulting AMP mechanisms and activity is still widely debated. AMP activity can vary widely by utilizing different tethering strategies, which include additional variables such as: (1) peptide choice and properties (such as native mechanism, concentration, charge, and structure), (2) tether choice and properties (such as chemical composition, length, charge, surface density, and flexibility), and (3) testing conditions (such as temperature, solvent composition and substrate type). Some studies suggest that AMP performance may be tether-dependent, for example some AMPs require longer tethers while others do not and some need a flexible tether. Thus, models for predicting successful tethering strategies for different AMP properties, which currently do not exist, must be developed. Further, complicated and often destructive techniques, such as XPS and SEM, are typically implemented to study the relationship of all these parameters vs. antimicrobial activity, which are labor-intensive and limited in scope. Predictive models guiding tether strategy need to be constructed, but also new techniques to study tethering be developed. If these technical milestones are achieved they can serve as a predicate for commercial implementation of a host of new therapies targeted at reducing device-associated HAIs. The overall goal of this thesis was to study the relationship between antimicrobial activity of tethered C-CHY1 examining both spacer length and peptide surface density and the development of a feasible clinical business case for tethered AMPs. To achieve this goal, a traditional entrepreneurial approach was taken in which a minimally-viable product was first designed and business case analyzed, followed by studies to better optimize and understand the underlying structure-mechanism relationships. CHY1 with a C-terminus cysteine to allow for surface-binding (C-CHY1) was tethered onto a silicon dioxide surface via a flexible poly(ethylene glycol) (PEG) tether, and then both surface binding behavior and antimicrobial success of C-CHY1 were examined as a function of tether properties and reaction conditions. For these studies, quartz-crystal microbalance with dissipation (QCM-D) was the primary technique, a real-time, non-destructive flow method that was then coupled with downstream characterization techniques: fluorescent microscopy and contact angle measurements. In parallel a deep dive into domestic and international business models for commercializing AMP technologies. Specifically, tether length and surface density effects on C-CHY1 mechanisms were studied, followed by the effect of temperature, type of microbe, and salt concentration on the antimicrobial mechanisms of tethered C-CHY1. QCM-D was used to measure binding of C-CHY1 via three different length tethers, PEG molecular weight (MW) 866, 2000 and 7500, followed by microscopy to measure antimicrobial effectiveness against two model microbes Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Modeling of QCM-D data allowed for surface density and thickness to be calculated and related to C-CHY1 antimicrobial activity. PEG 7500 allowed proper C-CHY1 orientation and mobility, allowing for its native pore-forming mechanism and highest activity while PEG 866 tethers led to denser grafting and an effective, yet non-native ion displacement mechanism. The QCM-D was used to characterize the effect of salt concentration and temperature reaction conditions on the grafting density of C-CHY1 tethered via PEG 866 and PEG 7500, which was then related to antimicrobial activity. For PEG MW 866, neither temperature nor salt concentration increases significantly altered the grafting density of C-CHY1 while for PEG 7500 increasing temperature allowed for significantly increased grafting density. C-CHY1 density had no significant effect on antimicrobial activity against either microbe. Temperature of bacterial incubation did demonstrate microbe-specific changes in C-CHY1 antimicrobial activity. These results demonstrated that small changes in reaction conditions can drastically change membrane selectivity of C-CHY1. An in-depth investigation of the effects of bacterial membrane composition and temperature on soluble C-CHY1 mechanism was implemented to better understand the molecular membrane- and temperature-dependent selectivity and structure-function of C-CHY1. Supported lipid bilayers (SLBs) formed in QCM-D can be used as model membranes to elucidate AMP action mechanisms against membranes of different compositions. Two and three component SLBs representative of Gram-negative phosphatidylethanolamine (PE) and phosphatidyglycerol acid (PG) with and without charged lipopolysaccharide, LPS and Gram-positive bacteria phosphatidylcholine (PC) and PG with and without charged lipoteichoic acid, (LTA) were formed at both 23°C and 37°C. C-CHY1 at 5 µM was exposed to the different membranes and mechanistic surface action was studied. The membranes formed highly different baseline responses in QCM-D, indicative of vastly different membrane structures, thicknesses and deposition behaviors on SiO2, warranting future studies. Further, significant effects of LTA incorporation were observed in both peptide interaction and deposition. There were measurable effects of temperature on membrane formation as well as peptide interaction kinetics and even mode of interaction. Lastly, business models for the commercialization of novel medical device technologies such as surface-tethered C-CHY1 were investigated. While this technology has the potential to solve many unmet needs, there must a commercialization plan implemented in order to have an impact. There is a clear disconnect between technology development in academia and technology commercialization in industry that must be connected. Development of an entrepreneurial mindset at the graduate school level, can help bridge the gap. A thorough investigation of domestic and international business models for commercializing AMP technologies was carried out and distilled in the form of the Business Model Canvas developed by Alexander Osterwalder that can be used as a roadmap for commercialization efforts. Using the QCM-D a relationship between both spacer length and peptide surface density and the antimicrobial activity of tethered C-CHY1 was determined. A business plan was developed in order to increase the impact of this and other AMP based work. This work provides a roadmap for future researchers to quickly develop and commercial novel AMP based coating technology.

Quartz Crystal Microbalance (QCM) is a sensitive and effective technique to analyze mass changes at the interface between a solid material and a liquid environment. In this Master thesis, QCM was employed for evaluating the interactions between selected degradable polymers and nanodiamond particles (nDP), fibronectin and the growth factor BMP-2.   Many parameters must be adapted to allow QCM measurements involving degradable polymers. These parameters were then tailored to allow QCM measurements with PLA, poly(LLA-co-CL), poly(TMC-D-LA) and PS.   Moreover, QCM provides quantitative measurements of protein adsorption on degradable polymers. The behavior of PLA and poly(LLA-co-CL) was further evaluated and compared with respect to protein adsorption. This behavior was demonstrated to be different for the two polymers considered and to be dependent on protein concentration in solution.   Eventually, exploiting QCM it was also possible to assess the relationship between nDP and the adsorption of fibronectin and BMP-2 onto PLA and poly(LLA-co-CL).

Electrochemical quartz crystal microbalance has been employed to investigate electro-responsiveness of an ionic liquid as an additive in lubricant oils on a gold surface. Polarisation of the surface reveals changes in frequency where an increase in magnitude amplified the observed response, corresponding to a controllable alternation of the ionic liquid configuration on the surface as a function of applied potential. The frequency changes are due to different packing of the anion and cation, respectively, on the surface as their mass densities and geometries are different. Relaxation of the system was reversible to the application of a potential and it was also found to be diffusion dependent, where the ratio between the ion diffusivities could be extracted from the results. Measurement of the system relaxation reveals a potential decay of that of a discharging capacitor, with an internal resistance inducing an initial potential drop due to the resistivity of the oil medium. The discharge behaviour was also proven to show high internal reproducibility validity within experiments. This newly discovered insight in responsive differences of ion packing is of importance, not only for ionic liquid additives in tribology, but for understanding and exploiting ionic liquids in an array of electrochemical applications.

Fluids play a vital role in essentially all geologic environments and processes, and are the principal media of heat and mass transfer in the Earth. The properties of geologic fluids can be diverse, as fluids occur at conditions ranging from ambient temperatures and pressures at Earth's surface, to extreme temperatures and pressures in Earth's deep interior. Regardless the wide ranges of conditions at which geologic fluids occur, fluid properties are described and governed by the same fundamental thermodynamic relationships. Thus, application of thermodynamic principles and methods allows us to decipher the properties and roles of geologic fluids, to help understand geologic processes. Fluid inclusions in minerals provide one of the best available tools to study the compositions of geological fluids. Compositions of fluid inclusions can be determined from microthermometric measurements, based on the vapor-saturated liquidus conditions of model chemical systems, or by various microanalytical techniques. The vaporsaturated liquidus relations of the system H2O-NaCl-CaCl2 have been modeled to allow estimation of fluid inclusion compositions by either microthermometric or microanalytical methods. Carbon capture and storage (CCS) in deep saline formations represents one option for reducing anthropogenic CO2 emissions into Earth's atmosphere. Availability of storage volume in deep saline formations is a significant component of injection and storage planning. Investigation of the volumetric properties of CO2, brine and CO2-saturated brine reveals that storage volume requirements are minimized when CO2 dissolves into brine. These results suggest that a protocol involving brine extraction, CO2 dissolution and re-injection may optimize CCS in deep saline formations. Numerical modeling of quartz dissolution and precipitation in a sub-seafloor hydrothermal system was used to understand the role of fluid-phase immiscibility ("boiling") on quartz-fluid interactions, and to predict where in the system quartz could deposit and trap fluid inclusions. The spatial distribution of zones of quartz dissolution and precipitation is complex, owing to the many inter-related factors controlling quartz solubility. Immiscibility exerts a strong control over the occurrence of quartz precipitation in the deeper regions of fluid circulation. / Ph. D.

Current dissolution apparatuses require several hundred milligrams of sample per trial, measure dissolution rate indirectly via concentration sampling, and cannot maintain sink conditions throughout the duration of a test. This work describes a novel dissolution testing methodology developed using a commercial quartz crystal microbalance (QCM) system to measure dissolution rates of drugs while overcoming the limitations of current dissolution methods. The apparatus was characterized for a sample drug system of benzoic acid dissolved using a dissolution medium of deionized water at flow rates of 1000, 100, 50, and 10 &mgr;L/min. Using an analysis method that combines the responses of resonance frequency and resistance of the quartz crystal during dissolution, the dissolution rate of benzoic acid was found to be 4.029 ± 0.743, 2.026 ± 0.913, 1.565 ± 0.349, and 1.060 ± 0.103 % mass/s, for each flow rate, respectively. The QCM dissolution apparatus method can be used to measure drug dissolution directly by quantifying mass loss (rather than indirectly via concentration changes as with current methods), reduce sample sizes compared with current methods by three orders of magnitude onto the microgram scale, and maintain sink conditions throughout the duration of the test.