Abstract This study was undertaken to identify mechanisms of adhesion of intraocular lenses (IOLs) to the capsular bag after cataract surgery and IOL implantation. It was also done to challenge the sandwich theory presented for posterior capsular opacification (PCO): If the IOL is made of a bioactive material it would allow a single lens epithelial cell layer to bond both to the IOL and the posterior capsule at the same time. This would produce a sandwich pattern including the IOL, the cell monolayer and the posterior capsule. The sealed sandwich structure would prevent further epithelial ingrowth. The degree of bioactivity of the IOL could explain the basic difference in the incidence of PCO and capsulotomy rates with different IOL materials. The sandwich theory was put forward on the basis of a search for a keratoprosthesis material, which would allow maximal adhesion of the prosthesis to corneal tissue. Titanium and glass-ceramic coated titanium were found to develop better adhesion than poly (methyl methacrylate) (PMMA). The adhesion of PMMA to the corneal stromal tissue was loose, and down growth of corneal epithelial cells was seen around the prosthesis. The differences between various IOL materials were first tested with rabbit corneal tissue cultures. There was better adhesion of corneal tissue to soft, hydrophobic acrylate than to PMMA, heparin surface modified (HSM)-PMMA, silicone or hydrogel IOLs. To assess differences in protein adhesion to IOL surfaces, different IOLs were incubated for 24 hours with radioactive iodine labeled fibronectin. Soft hydrophobic acrylate (AcrySof®) showed the highest binding of fibronectin, and the differences relative to all the other materials were significant (p < 0.01-0.001), except to PMMA (p = 0.31). The sandwich theory and the results with rabbit corneal tissue cultures and the protein adhesion study in vitro were evaluated against the results found in pseudophakic autopsy eyes. Altogether, 70 autopsy eyes were analyzed. From 38 autopsy eyes containing PMMA, silicone, soft hydrophobic acrylate or hydrogel IOLs histological sections were prepared from the capsular bag and immunohistochemical analyses were performed for fibronectin, vitronectin, laminin and collagen type IV. A total of 152 specimens were analyzed. From 32 autopsy eyes containing IOLs made of PMMA, silicone, acrylate or hydrogel, IOLs were explanted from the capsular bag and immunohistochemical analysis was done on both sides of the IOLs for fibronectin, vitronectin, laminin or collagen type IV. Soft hydrophobic acrylate IOLs had significantly more adhesion of fibronectin to their surfaces than PMMA or silicone IOLs. Also, more vitronectin was attached to acrylate IOLs than to the other IOL materials. Silicone IOLs had more collagen type IV adhesion in comparison to the other IOL materials studied. In histologic sections a sandwich-like structure (anterior or posterior capsule-fibronectin-one cell layer-fibronectin-IOL surface) was seen significantly more often in eyes with acrylate IOLs than in PMMA, silicone or hydrogel IOL eyes. These studies support the sandwich theory for posterior capsule opacification after cataract surgery with IOLs. The results suggest that fibronectin may be the major extracellular protein responsible for the attachment of acrylate IOLs to the capsular bag. This may represent a true bioactive bond between the IOL and the lens epithelial cells, and between the IOL and the capsular bag. This may explain the reason for clinical observations of less posterior capsular opacification and lower capsulotomy rates with the soft hydrophobic acrylate material of AcrySof® IOLs compared to the other IOL materials studied.

This document presents the modelling and characterization of novel photonic devices based on periodic arrays of multiwalled carbon nanotubes. Multiwalled carbon nanotubes are mostly metallic in nature and interesting plasmonic effects are observed when nanotubes are grown close together, with spacing of about 400 nm. The effective electronic mass on the nanotubes changes, due to mutual coupling between them and they start displaying dielectric properties which are inherently different from the their own, forming metamaterials. We present a plasmonic high pass filtering application of carbon nanotube based metamaterials. Some promising modelling and experimental results are demonstrated showing a strong cut-off filtering effect at the plasma frequency displayed by the periodic arrays of multiwalled carbon nanotubes. The artificial negative dielectric constant displayed by the nanotube arrays was also successfully utilised for producing micron-scaled applications like optical waveguides and negative lenses for overcoming the diffraction limit. The fabrication of these optical devices using the arrays of silicon nanopillars was also considered. These arrays when fabricated at nano-scaled dimensions (of about 400 nm) present a greater degree of periodicity and require a simpler fabrication process compared to carbon nanotubes. We report the detailed computational analysis on silicon nanopillars based photonic crystals, waveguides and metamaterials which operate well within in the optical regime. However, due to the fabrication limitations, the fabricated Si nanopillars presented an inverted cone shape profile along their lengths. These inverted nanocone structures were successfully utilised for enhancing reflection from Si surfaces for applications in photovoltaic devices. Lastly we present a novel application of carbon nanotube arrays for producing micron-scale Fresnel lens arrays. Forests of carbon nanotubes were utilised as absorbing media on top of a bare silicon substrate. Optical diffraction of light across the nanotube forests produced strong focusing of light, at focal lengths of order 125 microns. Numerical simulations were in excellent agreement with the measured results.

The Grängesberg Mining District (GMD) is located in the western part of the Bergslagen province in south central Sweden, and is the only known apatite-iron oxide mineralization south of Norrbotten. The Grängesberg deposit is the largest of the mineralizations along GMD and consists of a line of steeply to moderately dipping 20-100 m wide lenses extending to a depth of 1.7 km. It is hosted by felsic volcanic rocks that are phyllosilicate altered in the vicinity of the ore. Field relationships indicate that a competent granitoid was structurally emplaced on top of the ore during D2, and that the less competent phyllosilicate-rich host rocks accommodated large parts of the strain. These D2 structures described from the area around the ore bodies in Grängesberg include stretching lineation at the tapering edges of the lenses, asymmetric folds with opposite vergence along strike, sheath folds and possibly fold interference patterns. These structures are proposed to have formed in response to the competence contrast and the reverse movements on a large scale. The hypothesis is that the competence contrast between the competent ore and granitoid and the less competent host rocks could explain the formation and location of the key D2-structures in Grängesberg. To test the hypothesis, four analogue tectonic models were run in the centrifuge at the Hans Ramberg Tectonic Laboratory (HRTL), Uppsala University. The competent bodies were represented by an acrylic glass wedge with two lenses corresponding to the ore lenses, with an inclination of either 60° or 45° mimicking the approximate dip of the ore. Plasticine was used as the less competent host rocks. On the top surface, circles and squares were printed and used as strain markers. The models were run at c. 300-400 G until penetrative deformation and shortening ranging from 32.5 to 39.2% was reached. During centrifuging, the wedge indented the plasticine, resembling the possible deformation during thrusting of the deep granitoid. The models were then cut to reveal the structures formed, and one model was digitalized using the software Move. After shortening, the strain markers had deformed to show a change in direction of strain around the lenses. Vertical sections perpendicular to the shortening direction showed that stretching lineation developed between the lenses. Horizontal sections revealed asymmetric non-cylindrical folds with opposite vergence along strike and fold interference patterns. These results show that the observed field relationships were reproducible with the model setup, and that the competence contrast between the ore bodies, the granitoid and the host rocks could be the controlling factor for localization of shear and sites of stretching in the area.

Le concept de l'optique de transformation qui permet de contrôler le trajet des ondes électromagnétiques à volonté en appliquant une variation spatiale judicieusement définie dans les paramètres constitutifs, est exploré pour concevoir des nouveaux types d'antennes et de dispositifs micro-ondes. Dans une première partie, basée sur la transformation de coordonnées, un dispositif d'illusion capable de modifier l'apparence d'une émission électromagnétique et de la délocaliser, est validé par le biais de simulations numériques. Un dispositif de transition de guide d'ondes, permettant d'assurer une transmission quasi totale entre deux guides d'ondes de sections transversales différentes est également conçu et validé expérimentalement par l'utilisation des résonateurs à métamatériaux. Dans une seconde partie, la transformation de l'espace basée sur l'équation de Laplace est étudiée pour concevoir des lentilles pour les applications antennaires. Une lentille de focalisation capable de restaurer les émissions en phase d'un réseau conforme d'éléments rayonnants et une lentille à dépointage qui permet de dévier la direction du faisceau rayonné d'une antenne sont conçues. Des prototypes fabriqués à partir d'un matériau isotrope tout-diélectrique grâce à la technologie d'impression en trois dimensions (3D) permettent de valider expérimentalement la fonctionnalité des lentilles sur une large bande de fréquence. / The concept of transformation optics which can control electromagnetic waves at will by applying a judiciously defined spatial variation in the constitutive parameters is explored to design novel type antennas and microwave devices. In a first part, based on coordinate transformation, an illusion device able to modify the appearance of an electromagnetic emission and then delocalize it is validated through numerical simulations. A waveguide tapering device allowing to assure quasi-total transmission between two waveguides of different cross-sections is also designed and validated experimentally through the use of metamaterial resonators. In a second part, space transformation based on Laplace's equation is studied to design lenses for antenna applications. A beam focusing lens able to restore in-phase emissions from a conformal array of radiators and a beam steering lens that allows deflecting the radiated bema of an antenna are designed. Prototypes fabricated by an all-dielectric isotropic material through three-dimensional (3D) polyjet printing technology allow to experimentally validate the functionality of the lenses on a wide frequency range.

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This dissertation contributes to IS research by explaining user intentions while using AR features in mobile social networking and retail app contexts. It consists of three essays, which use partial least squares modeling to analyze different consumer behavior models. The first essay examines the influence of quality, human, and environmental factors on AR reuse intention in a mobile social networking context. The second essay introduces position relevance, a new construct essential to AR research in e-commerce, and it looks at the influence of this construct and app involvement on user purchase intention, while using view-in-room features on mobile retail apps. The third essay examines the influence of service quality and visual quality on recommendation intention of mobile retail apps while using view-in-room features compared to shopping without using these AR features.

Human tear film is an accessible biospecimen rich with useful biological information. As tear protein biomarkers for both ocular and systemic diseases have been identified in tears, efforts are being made to create point-of-care tests useful for clinical diagnoses. However, there are significant obstacles to tear diagnostics, including inadequate sampling methods and biomarkers with insufficient sensitivity and specificity. Furthermore, tear film diagnostics are particularly challenging for dry eye disease (DED) patients, where low tear volume makes sampling more difficult and the multifactorial nature of DED makes identifying the exact pathological subtype very complex. As soft contact lenses (SCLs) are designed for optimal ocular surface interaction and concentrate proteins on the eye regardless of tear volume, we hypothesized that we could improve tear sampling methods for research and diagnostic purposes. We further hypothesized that we could identify new and existing and DED biomarkers using SCL tear film sampling. To begin, we demonstrate SCL sampling in vitro and then compare SCLs to other current tear sampling methods in vivo. Objectively, we observe that SCLs do not show signs of ocular surface irritation, regardless of previous SCL use. We also see that SCLs sample similar types and amounts of proteins relative to other methods. Subjective assessments of tear sampling methods are also made by subjects. Our results indicate that training and experience in tear sampling are key components which may significantly impact subject experience as well as the tear type collected. Next, we optimized our tear sampling method by comparing different SCLs materials in search of an ideal lens. Our data show that certain combinations of SCL materials and mass spectrometry (MS) sample preparation methods can lead to significant polymer contamination in MS. Furthermore, we observe individual protein binding specificity based on SCL chemistry. Our experiments reveal etafilcon A and verofilcon A lenses as the optimal SCL materials for tear film sampling. Finally, a pilot study in DED candidates using SCL sampling confirms the presence of previously reported biomarkers in DED subjects as well as identifies new biomarkers for future validation studies. We also correlate clinical metrics to biochemical findings and identify correlations between tear film homeostasis and pathologic phenotypes. Ultimately, these studies demonstrate SCL sampling is an advantageous alternative to current tear film sampling methods, useful for biomarker discovery, and potentially, clinical diagnostics.

The development of compact imaging systems capable of transmitting high-resolution images in real-time while covering a wide field-of-view (FOV) is critical in a variety of military and civilian applications: surveillance, threat detection, target acquisition, tracking, remote operation of unmanned vehicles, etc. Recently, optical foveated imaging using liquid crystal (LC) spatial light modulators (SLM) has received considerable attention as a potential approach to reducing size and complexity in fast wide-angle lenses. The fundamental concept behind optical foveated imaging is reducing the number of elements in a fast wide-angle lens by placing a phase SLM at the pupil stop to dynamically compensate aberrations left uncorrected by the optical design. In the recent years, considerable research and development has been conducted in the field of optical foveated imaging based on the LC SLM technology, and several foveated optical systems (FOS) prototypes have been built. However, most research has been focused so far on the experimental demonstration of the basic concept using off the shelf components, without much concern for the practicality or the optical performance of the systems. Published results quantify only the aberration correction capabilities of the FOS, often claiming diffraction limited performance at the region of interest (ROI). However, these results have continually overlooked diffraction effects on the zero-order efficiency and the image quality. The research work presented in this dissertation covers the methods and results of a detailed theoretical research study on the diffraction analysis, image quality, design, and optimization of fast wide-angle FOSs based on the current transmissive LC SLM technology. The amplitude and phase diffraction effects caused by the pixelated aperture of the SLM are explained and quantified, revealing fundamental limitations imposed by the current transmissive LC SLM technology. As a part of this study, five different fast wide-angle lens designs that can be used to build practical FOSs were developed, revealing additional challenges specific to the optical design of fast wide-angle systems, such as controlling the relative illumination, distortion, and distribution of aberrations across a wide FOV. One of the lens design examples was chosen as a study case to demonstrate the design, analysis, and optimization of a practical wide-angle FOS based on the current state-of-the-art transmissive LC SLM technology. The effects of fabrication and assembly tolerances on the image quality of fast wide-angle FOSs were also investigated, revealing the sensitivity of these fast well-corrected optical systems to manufacturing errors. The theoretical study presented in this dissertation sets fundamental analysis, design, and optimization guidelines for future developments in fast wide-angle FOSs based on transmissive SLM devices.

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