The Use of Poly(vinyl alcohol)-based Hydrogels in Biomedical Applications

Polymers have found increasing favor in biomedical applications due to the greater control that researchers can exert over their properties. Researchers have focused on the development of therapies using biologically compatible polymers due to their ability to limit potentially harmful interactions with the body. This research has led to advances in tissue engineering, controlled and targeted drug delivery, and other biomedical fields, with the goal of improving both the effectiveness and accessibility of health care. Poly(vinyl alcohol) (PVA) hydrogels possess several chemical properties that make them well suited for biomedical applications. These include inertness and stability, biocompatibility, and pH-responsiveness. As a result, PVA based materials have been studied for potential applications in areas of biomedicine such as targeted drug delivery, tissue engineering, and wound healing. This thesis examines the properties of PVA and seeks to understand how the chemical and physical structure affects their properties. It then examines how these properties enhance their utility in potential biomedical applications. Finally, it reviews the research into development of PVA based materials for three different biomedical applications.Chemical Engineerin

Sparkle: Hover Feedback with Touchable Electric Arcs

Many finger sensing input devices now support proximity input, enabling users to perform in-air gestures. While near-surface interactions increase the input vocabulary, they lack tactile feedback, making it hard for users to perform gestures or to know when the interaction takes place. Sparkle stimulates the fingertip with touchable electric arcs above a hover sensing device to give users in-air tactile or thermal feedback, sharper and more feelable than acoustic mid-air haptic devices. We present the design of a high voltage resonant transformer with a low-loss soft ferrite core and self-tuning driver circuit, with which we create electric arcs 6 mm in length, and combine this technology with infrared proximity sensing in two proof-of-concept devices with form factor and functionality similar to a button and a touchpad. We provide design guidelines for Sparkle devices and examples of stimuli in application scenarios, and report the results of a user study on the perceived sensations. Sparkle is the first step towards providing a new type of hover feedback, and it does not require users to wear tactile stimulators

JDLED: towards visio-tactile displays based on electrochemical locomotion of liquid-metal Janus droplets

An actuated shape-changing interface with fast response and small pixel size using a liquid material can provide real time tangible interaction with the digital world in physical space. To this end, we demonstrate an interface that displays userdefined patterns dynamically using liquid metal droplets as programmable micro robots on a flat surface. We built a prototype using an array of embedded electrodes and a switching circuit to control the jump of the droplets from electrode to electrode. The actuation and dynamics of the droplets under the finger provides mild tactile feedback to the user. Our demo is the first to show a planar visio-tactile display using liquid metal, and is a first step to make shape-changing physical ephemeral widgets on a tabletop interface

Chameleon Devices: Investigating More Secure and Discreet Mobile Interactions via Active Camouflaging

Many users value the ability to have quick and frequent sight of their mobiles when in public settings. However, in doing so, they expose themselves to potential risks, ranging from being targets of robbery to the more subtle social losses through being seen to be rude or inattentive to those around them. In nature, some animals can blend into their environments to avoid being eaten or to reduce their impact on the ecosystem around them. Taking inspiration from these evolved systems we investigate the notion of chameleon approaches for mobile interaction design. Our probes were motivated, inspired and refined through extended interactions with people drawn from contexts with differing ranges of security and privacy concerns. Through deployments on users’ own devices, our prototypes show the value of the concept. The encouraging results motivate further research in materials and form factors that can provide more effective automatic plain-sight hiding

An evaluation of a price transparency intervention for two commonly prescribed medications on total institutional expenditure: a prospective study

Importance: Providing cost feedback has been demonstrated to decrease demand from clinicians. Objective: We tested the hypothesis that providing the cost of drugs to clinicians would modify total expenditure. Design: A prospective study design with a step-wise intervention. Setting/Participants: Individuals who were admitted to the XXX from November 2013 to November 2015 under the physicians. Intervention: The cost of all antibiotics and inhaled corticosteroids was added to the electronic prescribing system. Main outcomes: The weekly cost for antibiotics and inhaled corticosteroids in the intervention period compared to baseline. Results: Mean weekly expenditure on antibiotics per patient decreased by £3.75 (95% confidence intervals CI: -6.52 to -0.98) after the intervention from a pre-intervention mean of £26.44, and then slowly increased subsequently by £0.10/week (95%CI: +0.02 to +0.18). Mean weekly expenditure on inhaled corticosteroids per patient did not substantially change after the intervention (-£0.03, 95%CI: -0.06 to -0.01 after the intervention from a pre-intervention mean of £5.29 per person). New clinical guidelines for inhaled corticosteroids were associated with a decrease in weekly expenditure. Conclusions and relevance: Provision of cost feedback resulted in no sustained change in institutional expenditure. However, clinical guidelines have potential for modifying clinical prescribing behaviour

Programmable liquid matter: 2D shape drawing of liquid metals by dynamic electric field

We present a programmable liquid matter which can dynamically transform its 2D shape into a variety of forms and present unique organic animations based on spatio-temporally controlled electric fields. We deployed a EGaIn (Gallium indium eutectic alloy) liquid metal as our smart liquid material since it features a superior electric conductivity in spite of a liquid state and presents a high dynamic range of surface tension and 2D area controlled by applied voltage strength and polarity. Our proposed liquid metal shape and motion control algorithms with dynamically patterned electric fields realize path tracing organic animation. We demonstrate an interactive 7x7 electrode array control system with a computer vision based GUI system to enable novice users to physically draw alphabet letters and 2D shapes by unique animatronics of liquid metals

Analysis of Fcγ receptor haplotypes in rheumatoid arthritis: FCGR3A remains a major susceptibility gene at this locus, with an additional contribution from FCGR3B

The Fcγ receptors play important roles in the initiation and regulation of many immunological and inflammatory processes, and genetic variants (FCGR) have been associated with numerous autoimmune and infectious diseases. The data in rheumatoid arthritis (RA) are conflicting and we previously demonstrated an association between FCGR3A and RA. In view of the close molecular proximity with FCGR2A, FCGR2B and FCGR3B, additional polymorphisms within these genes and FCGR haplotypes were examined to refine the extent of association with RA. Biallelic polymorphisms in FCGR2A, FCGR2B and FCGR3B were examined for association with RA in two well characterized UK Caucasian and North Indian/Pakistani cohorts, in which FCGR3A genotyping had previously been undertaken. Haplotype frequencies and linkage disequilibrium were estimated across the FCGR locus and a model-free analysis was performed to determine association with RA. This was followed by regression analysis, allowing for phase uncertainty, to identify the particular haplotype(s) that influences disease risk. Our results reveal that FCGR2A, FCGR2B and FCGR3B were not associated with RA. The haplotype with the strongest association with RA susceptibility was the FCGR3A–FCGR3B 158V-NA2 haplotype (odds ratio 3.18, 95% confidence interval 1.13–8.92 [P = 0.03] for homozygotes compared with all genotypes). The association was stronger in the presence of nodules (odds ratio 5.03, 95% confidence interval 1.44–17.56; P = 0.01). This haplotype was also more common in North Indian/Pakistani RA patients than in control individuals, but not significantly so. Logistic regression analyses suggested that FCGR3A remained the most significant gene at this locus. The increased association with an FCGR3A–FCGR3B haplotype suggests that other polymorphic variants within FCGR3A or FCGR3B, or in linkage disequilibrium with this haplotype, may additionally contribute to disease pathogenesis

III-V-on-silicon photonic devices for optical communication and sensing

In the paper, we review our work on heterogeneous III-V-on-silicon photonic components and circuits for applications in optical communication and sensing. We elaborate on the integration strategy and describe a broad range of devices realized on this platform covering a wavelength range from 850 nm to 3.85 μm

Techniques, Tricks and Algorithms for Efficient GPU-Based Processing of Higher Order Hyperbolic PDEs

GPU computing is expected to play an integral part in all modern Exascale supercomputers. It is also expected that higher order Godunov schemes will make up about a significant fraction of the application mix on such supercomputers. It is, therefore, very important to prepare the community of users of higher order schemes for hyperbolic PDEs for this emerging opportunity. We focus on three broad and high-impact areas where higher order Godunov schemes are used. The first area is computational fluid dynamics (CFD). The second is computational magnetohydrodynamics (MHD) which has an involution constraint that has to be mimetically preserved. The third is computational electrodynamics (CED) which has involution constraints and also extremely stiff source terms. Together, these three diverse uses of higher order Godunov methodology, cover many of the most important applications areas. In all three cases, we show that the optimal use of algorithms, techniques and tricks, along with the use of OpenACC, yields superlative speedups on GPUs! As a bonus, we find a most remarkable and desirable result: some higher order schemes, with their larger operations count per zone, show better speedup than lower order schemes on GPUs. In other words, the GPU is an optimal stratagem for overcoming the higher computational complexities of higher order schemes! Several avenues for future improvement have also been identified. A scalability study is presented for a real-world application using GPUs and comparable numbers of high-end multicore CPUs. It is found that GPUs offer a substantial performance benefit over comparable number of CPUs, especially when all the methods designed in this paper are used.Comment: 73 pages, 17 figure