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Iterative Size Reduction of Bead Placement in Nanosphere Lithography

Description

Nanosphere lithography is a high throughput procedure that has important implications
for facile, low cost scaling of nanostructures. However, current benchtop experiments have
limitations based on the placement of molecular species that exhibit greater than singlemolecular binding. In addition, reliance

Nanosphere lithography is a high throughput procedure that has important implications
for facile, low cost scaling of nanostructures. However, current benchtop experiments have
limitations based on the placement of molecular species that exhibit greater than singlemolecular binding. In addition, reliance upon bottom-up self-assembly of close-packed
nanospheres makes it problematic to resolve images using low-cost light microscopes due to the
spacing limitations smaller in magnitude than light wavelength. One method that is created to
resolve this issue is iterative size reduction (ISR), where repetitive ‘iterative’ processes are
employed in order to increase the precision at which single molecules bind to a given substrate.
ISR enables inherent separation of nanospheres and therefore any subsequent single molecule
binding platforms. In addition, ISR targets and encourages single-molecule binding by
systematically reducing binding site size. Results obtained pursuing iteratively reduced
nanostructures showed that many factors are needed to be taken into consideration, including
functionalization of nanosphere particles, zeta potential, and protonation-buffer reactions.
Modalities used for observation of nanoscale patterning and single-molecule binding included
atomic force microscopy (AFM) and ONI super-resolution and fluorescence microscopy. ISR
was also used in conjunction with zero mode waveguides, which are nanoapertures enabling realtime single molecule observation at zeptoliter volumes. Although current limitations and
obstacles still exist with reproducibility and scalability of ISR, it nonetheless exhibits limitless
potential and flexibility in nanotechnology applications.

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2020-05

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Does chronic unpredictable restraint produce dendritic retraction in long-shaft CA3 hippocampal neurons?

Description

Major Depressive Disorder (MDD) is a widespread mood disorder that affects more than 300 million people worldwide and yet, high relapse rates persist. This current study aimed to use an animal model for depression, unpredictable intermittent restraint (UIR), to investigate

Major Depressive Disorder (MDD) is a widespread mood disorder that affects more than 300 million people worldwide and yet, high relapse rates persist. This current study aimed to use an animal model for depression, unpredictable intermittent restraint (UIR), to investigate changes in a subset of neurons within the hippocampus, a region of high susceptibility in MDD. Adult male and female Sprague-Dawley rats were randomly assigned to four treatment groups based on sex (n = 48, n = 12/group). Half of the rats underwent UIR that involved restraint with orbital shaking (30 min or 1 h) for 2-6 consecutive days, followed by one or two days of no stressors; the other half of the rats were undisturbed (CON). UIR rats were stressed for 28 days (21 days of actual stressors) before behavioral testing began with UIR continuing between testing days for nearly 70 days. Rats were then euthanized between 9 and 11 days after the last UIR session. Brains were processed for Golgi stain and long-shaft (LS) neurons within the hippocampal CA3a and CA3b regions were quantified for dendritic complexity using a Camera Lucida attachment. Our findings failed to support our hypothesis that UIR would produce apical dendritic retraction in CA3 hippocampal LS neurons in both males and females. Given that UIR failed to produce CA3 apical dendritic retraction in males, which is commonly observed in the literature, we discuss several reasons for these findings including, time from the end of UIR to when brains were sampled, and the effects of repeated cognitive testing. Given our published findings that UIR impaired spatial ability in males, but not females, we believe that UIR holds validity as a chronic stress paradigm, as UIR attenuated body weight gain in both males and females and produced reductions in thymus gland weight in UIR males. These findings corroborate UIR as an effective stressor in males and warrant further research into the timing of UIR-induced changes in hippocampal CA3 apical dendritic morphology.

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2020-12

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Towards Purification of human TRPV1 Pore Domain

Description

The transient receptor potential channel subfamily V member 1 (TRPV1) functions as the heat and capsaicin receptor. It can be activated by heat, protons, pungent chemicals, and a variety of other endogenous mediators of nociception. TRPV1 is a non-selective cation

The transient receptor potential channel subfamily V member 1 (TRPV1) functions as the heat and capsaicin receptor. It can be activated by heat, protons, pungent chemicals, and a variety of other endogenous mediators of nociception. TRPV1 is a non-selective cation channel consisting of 6 transmembrane domains (S1-S6), with helices S1-S4 forming the sensing domain and the S5-S6 helices forming the pore domain. Understanding the TRPV1 channel is imperative due to its relation to a variety of human diseases, including cancer, type II diabetes, hyper and hypothermia, and inflammatory disorders of the airways and bladder. Although TRPV1 is the best-studied thermosensitive-TRP channels of all the 28 family members, the molecular underpinning and the contributions of the human TRPV1 pore domain in thermo-sensing remains elusive. Recently, the human TRPV1 sensing domain was found to contribute to heat activation. It was found to undergo a non-denaturing temperature-dependent conformational change. This finding triggered interest in studying the function and the role of the human TRPV1 pore domain in the heat activation process. Specifically, to identify whether heat activation is intrinsic to the pore domain. This thesis paper explores and optimizes the purification protocol of the human TRPV1 pore domain through three different methods. The first method was using a denaturant, the second method was increasing the length of the histidine tags through Q5 insertion, and the third method was incorporating the protein construct into nanodiscs. In addition to the above three methods, size exclusion chromatography and ion-exchange chromatography were utilized after thrombin cleavage to separate the human TRPV1 pore domain from the cleaved MBP deca-histidine tags as well as the impurities.

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2020-12

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Optical Response of a TiN Kinetic Inductance Detector (KID)

Description

This research compares shifts in a SuperSpec titanium nitride (TiN) kinetic inductance detector's (KID's) resonant frequency with accepted models for other KIDs. SuperSpec, which is being developed at the University of Colorado Boulder, is an on-chip spectrometer designed with a

This research compares shifts in a SuperSpec titanium nitride (TiN) kinetic inductance detector's (KID's) resonant frequency with accepted models for other KIDs. SuperSpec, which is being developed at the University of Colorado Boulder, is an on-chip spectrometer designed with a multiplexed readout with multiple KIDs that is set up for a broadband transmission of these measurements. It is useful for detecting radiation in the mm and sub mm wavelengths which is significant since absorption and reemission of photons by dust causes radiation from distant objects to reach us in infrared and far-infrared bands. In preparation for testing, our team installed stages designed previously by Paul Abers and his group into our cryostat and designed and installed other parts necessary for the cryostat to be able to test devices on the 250 mK stage. This work included the design and construction of additional parts, a new setup for the wiring in the cryostat, the assembly, testing, and installation of several stainless steel coaxial cables for the measurements through the devices, and other cryogenic and low pressure considerations. The SuperSpec KID was successfully tested on this 250 mK stage thus confirming that the new setup is functional. Our results are in agreement with existing models which suggest that the breaking of cooper pairs in the detector's superconductor which occurs in response to temperature, optical load, and readout power will decrease the resonant frequencies. A negative linear relationship in our results appears, as expected, since the parameters are varied only slightly so that a linear approximation is appropriate. We compared the rate at which the resonant frequency responded to temperature and found it to be close to the expected value.

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2018-05

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Golf Courses in Maricopa County: An Application of the Hedonic Pricing Method

Description

This study estimates the capitalization effect of golf courses in Maricopa County using the hedonic pricing method. It draws upon a dataset of 574,989 residential transactions from 2000 to 2006 to examine how the aesthetic, non-golf benefits of golf courses

This study estimates the capitalization effect of golf courses in Maricopa County using the hedonic pricing method. It draws upon a dataset of 574,989 residential transactions from 2000 to 2006 to examine how the aesthetic, non-golf benefits of golf courses capitalize across a gradient of proximity measures. The measures for amenity value extend beyond home adjacency and include considerations for homes within a range of discrete walkability buffers of golf courses. The models also distinguish between public and private golf courses as a proxy for the level of golf course access perceived by non-golfers. Unobserved spatial characteristics of the neighborhoods around golf courses are controlled for by increasing the extent of spatial fixed effects from city, to census tract, and finally to 2000 meter golf course ‘neighborhoods.’ The estimation results support two primary conclusions. First, golf course proximity is found to be highly valued for adjacent homes and homes up to 50 meters way from a course, still evident but minimal between 50 and 150 meters, and insignificant at all other distance ranges. Second, private golf courses do not command a higher proximity premia compared to public courses with the exception of homes within 25 to 50 meters of a course, indicating that the non-golf benefits of courses capitalize similarly, regardless of course type. The results of this study motivate further investigation into golf course features that signal access or add value to homes in the range of capitalization, particularly for near-adjacent homes between 50 and 150 meters thought previously not to capitalize.

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2018-05

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Fundamentals of Blockchain in the Supply Chain

Description

The objective of this paper is to provide an educational diagnostic into the technology of blockchain and its application for the supply chain. Education on the topic is important to prevent misinformation on the capabilities of blockchain. Blockchain as a

The objective of this paper is to provide an educational diagnostic into the technology of blockchain and its application for the supply chain. Education on the topic is important to prevent misinformation on the capabilities of blockchain. Blockchain as a new technology can be confusing to grasp given the wide possibilities it can provide. This can convolute the topic by being too broad when defined. Instead, the focus will be maintained on explaining the technical details about how and why this technology works in improving the supply chain. The scope of explanation will not be limited to the solutions, but will also detail current problems. Both public and private blockchain networks will be explained and solutions they provide in supply chains. In addition, other non-blockchain systems will be described that provide important pieces in supply chain operations that blockchain cannot provide. Blockchain when applied to the supply chain provides improved consumer transparency, management of resources, logistics, trade finance, and liquidity.

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2018-05

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Integrated Breast Biopsy Bioimpedance Sensor

Description

Breast microcalcifications are a potential indicator of cancerous tumors. Current visualization methods are either uncomfortable or impractical. Impedance measurement studies have been performed, but not in a clinical setting due to a low sensitivity and specificity. We are hoping to

Breast microcalcifications are a potential indicator of cancerous tumors. Current visualization methods are either uncomfortable or impractical. Impedance measurement studies have been performed, but not in a clinical setting due to a low sensitivity and specificity. We are hoping to overcome this challenge with the development of a highly accurate impedance probe on a biopsy needle. With this technique, microcalcifications and the surrounding tissue could be differentiated in an efficient and comfortable manner than current techniques for biopsy procedures. We have developed and tested a functioning prototype for a biopsy needle using bioimpedance sensors to detect microcalcifications in the human body. In the final prototype a waveform generator sends a sin wave at a relatively low frequency(<1KHz) into the pre-amplifier, which both stabilizes and amplifies the signal. A modified howland bridge is then used to achieve a steady AC current through the electrodes. The voltage difference across the electrodes is then used to calculate the impedance being experienced between the electrodes. In our testing, the microcalcifications we are looking for have a noticeably higher impedance than the surrounding breast tissue, this spike in impedance is used to signal the presence of the calcifications, which are then sampled for examination by radiology.

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2018-05

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Assessing the Navigational Abilities of an Acoustically Active Cannula

Description

The purpose of this thesis experiment was to design and create an Acoustically Active Cannula (AAC), which is furnished by a piezoelectric crystal placed at its tip that produces an acoustic navigation signal. I tested the functionality of the cannula

The purpose of this thesis experiment was to design and create an Acoustically Active Cannula (AAC), which is furnished by a piezoelectric crystal placed at its tip that produces an acoustic navigation signal. I tested the functionality of the cannula in vitro and demonstrated its navigational abilities in vivo in anesthetized pigs. This experiment was based upon ultrasound science and technology, and thus some practical experience with conventional (B-mode) and Doppler ultrasound was achieved as well. The results of bench and experimental animal studies indicated proper functionality of the AAC for identification and spatial navigation of its tip with color Doppler ultrasound imaging.

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2018-05

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Evaluation of an Original Design for a Cost-Effective Wheel-Mounted Dynamometer for Road Vehicles

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This thesis evaluates the viability of an original design for a cost-effective wheel-mounted dynamometer for road vehicles. The goal is to show whether or not a device that generates torque and horsepower curves by processing accelerometer data collected at the

This thesis evaluates the viability of an original design for a cost-effective wheel-mounted dynamometer for road vehicles. The goal is to show whether or not a device that generates torque and horsepower curves by processing accelerometer data collected at the edge of a wheel can yield results that are comparable to results obtained using a conventional chassis dynamometer. Torque curves were generated via the experimental method under a variety of circumstances and also obtained professionally by a precision engine testing company. Metrics were created to measure the precision of the experimental device's ability to consistently generate torque curves and also to compare the similarity of these curves to the professionally obtained torque curves. The results revealed that although the test device does not quite provide the same level of precision as the professional chassis dynamometer, it does create torque curves that closely resemble the chassis dynamometer torque curves and exhibit a consistency between trials comparable to the professional results, even on rough road surfaces. The results suggest that the test device provides enough accuracy and precision to satisfy the needs of most consumers interested in measuring their vehicle's engine performance but probably lacks the level of accuracy and precision needed to appeal to professionals.

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2018-05

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Ambassador Communities, Hybrid Spectatorship, and Other Indicators of Success in eSports

Description

The academic study of eSports, or professional competition through the medium of video games, has tended to focus on players' motivations to play and watch eSports as well as marketing concerns of huge eSports corporations. Instead of utilizing marketing or

The academic study of eSports, or professional competition through the medium of video games, has tended to focus on players' motivations to play and watch eSports as well as marketing concerns of huge eSports corporations. Instead of utilizing marketing or psychology to analyze this phenomenon, I investigate three areas of focus in accordance with available literature: the fans and their characteristics, the design of the game itself, and the relationship between fans and the game's developer. This investigation was conducted by first examining existing literature surrounding eSports fans, then collecting public domain data such as Reddit posts, forum posts, and YouTube videos, and last by studying interviews with developers and players. With this thesis, I apply a fan studies approach to eSports by creating a series of indicators based in each of the three focus areas which can be utilized as a systematic method of evaluating an eSport's popularity and growth.

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2018-05