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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Improving Communication Between Cancer Patients and Providers During a 15-Minute Office Visit: A Systematic Review of the Literature

Manganelli, Dr. Tammy Elizabeth 01 January 2016 (has links)
Patients undergoing chemotherapy treatments for cancer often experience adverse side effects, including cognitive deficits. These deficits impact the patient's ability to communicate effectively with their oncology provider. Ineffective communication can adversely affect patient outcomes and decrease patient-provider satisfaction. The resulting poor communication can contribute to poor patient outcomes. This systematic literature review focused on assistive communication tools that could be used in an outpatient oncology setting to improve patient-provider communication. The literature review findings led to the development of a resource for providers that includes 15 communication tools that can be used to assess and improve communication in cancer care. Initially 4, 533 articles were identified using the search terms; cancer patient/providers, communication tools, chemo brain, and improving/ineffective communications. Articles were selected for inclusion that included communication tools, which assisted oncology providers in improving cancer care. Articles were excluded if they were not specific to cancer patients and did not contain communication tools. Analysis of the systematic review of the literature utilized Bandolier's hierarchy levels of evidence. The Health Promotion Model serves as the theoretical framework to guide the project. Oncology providers that utilized communication tools with patients found an 116% improvement in documentation of symptoms, adverse effects, and corresponding medical management compared to providers who did not use communication tools. Implementation of communication tools in outpatient oncology settings can result in a positive social change in the patient-provider relationship during cancer treatment.
22

Novel CMOS-Compatible Optical Platform

Pitera, Arthur J., Groenert, M. E., Yang, V. K., Lee, Minjoo L., Leitz, Christopher W., Taraschi, G., Cheng, Zhiyuan, Fitzgerald, Eugene A. 01 1900 (has links)
A research synopsis is presented summarizing work with integration of Ge and III-V semiconductors and optical devices with Si. III-V GaAs/AlGaAs quantum well lasers and GaAs/AlGaAs optical circuit structures have been fabricated on Si using Ge/GeSi/Si virtual substrates. The lasers fabricated on bulk GaAs showed similar output characteristics as those on Si. The GaAs/AlGaAs lasers fabricated on Si emitted at 858nm and had room temperature cw lifetimes of ~4hours. Straight optical links integrating an LED emitter, waveguide and detector exhibited losses of approximately 144dB/cm. A process for fabrication of a novel CMOS-compatible platform that integrates III-V or Ge layers with Si is demonstrated. Thin Ge layers have been transferred from Ge/GeSi/Si virtual substrates to bulk Si utilizing wafer bonding and an epitaxial Si CMP layer to facilitate virtual substrate planarization. A unique CMP-less method for removal of Ge exfoliation damage induced by the SmartCut™ process is also presented. / Singapore-MIT Alliance (SMA)
23

A Highly Sensitive, Integrable, Multimode, Evanescent-Wave Chem/bio Sensor

Lillie, Jeffrey J 07 June 2005 (has links)
A fully integrated optical chem/bio sensor complete with integrated source, chemically sensitive waveguide, detector arrays, and associated signal processing electronics on a Si-CMOS chip is a challenging, but highly desirable goal. An evanescent-wave multimode interferometric sensing element is a sensitive method for sensing, which is easily integrated on Si-CMOS. This work is concerned with the design, analysis, and demonstration of a planar multimode interferometric chem/bio sensor that is compatible with the fabrication constraints of Si-CMOS. A 4000-micron-long interferometric that can be adapted for different agents by a particular sensing layer has been fabricated on silicon using silicon dioxide and silicon oxynitride. Hexaflouro-isopropanol substituted polynorbornene is the sensing layer. This sensor has also been fabricated on a Si-CMOS circuit with embedded photodetectors. A sensor on silicon was demonstrated with a minimum detectable index change of 2.0x10-6 using an accurate gas delivery system and a custom hermetic waveguide test chamber. A modal pattern analysis strategy has also been developed to extract the optimal SNR from the measured modal patterns. An understanding of the noise processes and spatial bandwidth effects has enabled an experimentally-based prediction of the index sensitivity of a fully integrated multimode chem/bio sensor on Si-CMOS at 9.2 x10-7. Theoretically, the sensitivity enhancement of high over low index sensing layers and transverse-magnetic over transverse electric modes is described. Also, the sensitivity enhancement of higher-order-transverse modes has been quantified. The wide-angle beam propagation method has been used to simulate the sensor. This simulation showed the relation between the modal pattern repetition period and sensor sensitivity. Further, the modal coupling properties of the multimode y-junction have been described. A second multimode y-junction has been designed to change the modal excitation under the SL, and thus the sensitivity. The chemo-optic response of the `substituted polynorbornene' polymer., hexaflouro-isopropanol substituted polynorbornene to methanol, water, iso-propanol, and benzene has been measured. Also, its thermo-optic response has been measured. Athermal interferometric chem/bio sensors have then been suggested.
24

Modeling Microdomain Evolution on Giant Unilamellar Vesicles using a Phase-Field Approach

Embar, Anand Srinivasan January 2013 (has links)
<p>The surface of cell membranes can display a high degree of lateral heterogeneity. This non-uniform distribution of constituents is characterized by mobile nanodomain clusters called rafts. Enriched by saturated phospholipids, cholesterol and proteins, rafts are considered to be vital for several important cellular functions such as signalling and trafficking, morphological transformations associated with exocytosis and endocytosis and even as sites for the replication of viruses. Understanding the evolving distribution of these domains can provide significant insight into the regulation of cell function. Giant vesicles are simple prototypes of cell membranes. Microdomains on vesicles can be considered as simple analogues of rafts on cell membranes and offer a means to study various features of cellular processes in isolation. </p><p>In this work, we employ a continuum approach to model the evolution of microdomains on the surface of Giant Unilamellar Vesicles (GUVs). The interplay of species transport on the vesicle surface and the mechanics of vesicle shape change is captured using a chemo-mechanical model. Specifically, the approach focuses on the regime of vesicle dynamics where shape change occurs on a much faster time scale in comparison to species transport, as has been observed in several experimental studies on GUVs. In this study, shape changes are assumed to be instantaneous, while species transport, which is modeled by phase separation and domain coarsening, follows a natural time scale described by the Cahn--Hilliard dynamics.</p><p>The curvature energy of the vesicle membrane is defined by the classical Canham--Helfrich--Evans model. Dependence of flexural rigidity and spontaneous curvature on the lipid species is built into the energy functional. The chemical energy is characterized by a Cahn--Hilliard type density function that intrinsically captures the line energy of interfaces between two phases. Both curvature and chemical contributions to the vesicle energetics are consistently non-dimensionalized.</p><p>The coupled model is cast in a diffuse-interface form using the phase-field framework. The phase-field form of the governing equations describing shape equilibrium and species transport are both fourth-order and nonlinear. The system of equations is discretized using the finite element method with a uniform cubic-spline basis that satisfies global higher-order continuity. For shape equilibrium, geometric constraints of constant internal volume and constant surface area of the vesicle are imposed weakly using the penalty approach. A time-stepping scheme based on the unconditionally gradient-stable convexity-splitting technique is employed for explicit time integration of nonlocal integrals arising from the geometric constraints.</p><p>Numerical examples of axisymmetric stationary shapes of uniform vesicles are presented. Further, two- and three-dimensional numerical examples of domain formation and growth coupled to vesicle shape changes are discussed. Simulations qualitatively depicting curvature-dependent domain sorting and shape changes to minimize line tension are presented. The effect of capturing the difference in time scales is also brought out in a few numerical simulations that predict a starkly different pathway to equilibrium.</p> / Dissertation
25

CO₂ geological storage: hydro-chemo-mechanically coupled phenomena and engineered injection

Kim, Seunghee 08 August 2012 (has links)
Global energy consumption will increase in the next decades and it is expected to largely rely on fossil fuels. The use of fossil fuels is intimately related to CO₂ emissions and the potential for global warming. Geological CO₂ storage aims to mitigate the global warming problem by sequestering CO₂ underground. Coupled hydro-chemo-mechanical phenomena determine the successful operation and long term stability of CO₂ geological storage. This research explores various coupled phenomena, identifies different zones in the storage reservoir, and investigates their implications in CO₂ geological storage. Spatial patterns in mineral dissolution and precipitation are examined based on a comprehensive mass balance formulation. CO₂-dissolved fluid flow is modeled using a novel technique that couples laminar flow, advective and diffusive mass transport of species, mineral dissolution, and consequent pore changes to study the reactive fluid transport at the scale of a single rock fracture. The methodology is extended to the scale of a porous medium using pore network simulations to study both CO₂ reservoirs and caprocks. The two-phase flow problem between immiscible CO₂ and the formation fluid (water or brine) is investigated experimentally. Plug tests on shale and cement specimens are used to investigate CO₂ breakthrough pressure. Sealing strategies are explored to plug existing cracks and increase the CO₂ breakthrough pressure. Finally, CO₂-water-surfactant mixtures are evaluated to reduce the CO₂-water interfacial tension in view of enhanced sweep efficiency. Results can be used to identify optimal CO₂ injection and remediation strategies to maximize the efficiency of CO₂ injection and to attain long-term storage.
26

Effects of Chemotherapy on Neural Processes During Cognitive Functioning in Early-Stage Breast Cancer Patients: An fMRI Study

Wallis, Nancy J. 09 July 2013 (has links)
Functional Magnetic Resonance Imaging (fMRI) was used to examine brain activity in women with early stage Breast Cancer (BC) and to compare their neural profiles to a matched control group. This was accomplished as participants performed two working memory tasks, before and at two time points following the chemotherapy intervention of the BC group. Nineteen BC patients between the ages of 18 and 65 years were recruited from the Ottawa Hospital Regional Cancer Centre. The nineteen control participants were matched on sex, language, age and education. The results, from whole brain analyses, show significant differences in neural activity between BC patients and matched control participants during both verbal and visuospatial working memory tasks, before and right after chemotherapy. However, these differences were no longer observed one year post chemotherapy for verbal WM processing. Performance results were not significantly different between groups until the third imaging sessions when patients made significantly more errors of omission than controls for both tasks. Importantly, mood, anxiety and fatigue all played significant roles in the observed findings demonstrating the multifaceted nature of the impact of both cancer and chemotherapy on neural function during working memory. This is one of the first fMRI studies to measure neural activations during cognitive performance both before and after chemotherapy in BC patients and a control group while controlling for many potentially confounding variables. While BC patients should be made aware of the potential cognitive challenges they might face before, during and shortly after treatment, they can also feel reassured that these impairments may not be long lasting.
27

Kinase-driven metabolic signalling as a predictor of response to carboplatin–paclitaxel adjuvant treatment in advanced ovarian cancers

Sereni, Maria Isabella, Baldelli, Elisa, Gambara, Guido, Ravaggi, Antonella, Hodge, K Alex, Alberts, David S, Guillen-Rodriguez, Jose M, Dong, Ting, Memo, Maurizio, Odicino, Franco, Angioli, Roberto, Liotta, Lance A, Pecorelli, Sergio L, Petricoin, Emanuel F, Pierobon, Mariaelena 29 June 2017 (has links)
Background: The biological mechanisms underlying early-and advanced-stage epithelial ovarian cancers (EOCs) are still poorly understood. This study explored kinase-driven metabolic signalling in early and advanced EOCs, and its role in tumour progression and response to carboplatin-paclitaxel treatment. Methods: Tumour epithelia were isolated from two independent sets of primary EOC (n-72 and 30 for the discovery and the validation sets, respectively) via laser capture microdissection. Reverse phase protein microarrays were used to broadly profile the kinase-driven metabolic signalling of EOC with particular emphasis on the LBK1-AMPK and AKT-mTOR axes. Signalling activation was compared between early and advanced lesions, and carboplatin-paclitaxel-sensitive and -resistant tumours. Results: Advanced EOCs were characterised by a heterogeneous kinase-driven metabolic signature and decreased phosphorylation of the AMPK-AKT-mTOR axis compared to early EOC (P<0.05 for AMPK alpha T172, AMPK alpha 1 S485, AMPK beta 1 S108, AKT S473 and T308, mTOR S2448, p70S6 S371, 4EBP1 S65, GSK-3 alpha/beta S21/9, FOXO1 T24/FOXO3 T32, and FOXO1 S256). Advanced tumours with low relative activation of the metabolic signature and increased FOXO1 T24/FOXO3 T32 phosphorylation (P=0.041) were associated with carboplatin-paclitaxel resistance. Conclusions: If validated in a larger cohort of patients, the decreased AMPK-AKT-mTOR activation and phosphorylation of FOXO1 T24/FOXO3 T32 may help identify carboplatin-paclitaxel-resistant EOC patients.
28

Effects of Chemotherapy on Neural Processes During Cognitive Functioning in Early-Stage Breast Cancer Patients: An fMRI Study

Wallis, Nancy J. January 2013 (has links)
Functional Magnetic Resonance Imaging (fMRI) was used to examine brain activity in women with early stage Breast Cancer (BC) and to compare their neural profiles to a matched control group. This was accomplished as participants performed two working memory tasks, before and at two time points following the chemotherapy intervention of the BC group. Nineteen BC patients between the ages of 18 and 65 years were recruited from the Ottawa Hospital Regional Cancer Centre. The nineteen control participants were matched on sex, language, age and education. The results, from whole brain analyses, show significant differences in neural activity between BC patients and matched control participants during both verbal and visuospatial working memory tasks, before and right after chemotherapy. However, these differences were no longer observed one year post chemotherapy for verbal WM processing. Performance results were not significantly different between groups until the third imaging sessions when patients made significantly more errors of omission than controls for both tasks. Importantly, mood, anxiety and fatigue all played significant roles in the observed findings demonstrating the multifaceted nature of the impact of both cancer and chemotherapy on neural function during working memory. This is one of the first fMRI studies to measure neural activations during cognitive performance both before and after chemotherapy in BC patients and a control group while controlling for many potentially confounding variables. While BC patients should be made aware of the potential cognitive challenges they might face before, during and shortly after treatment, they can also feel reassured that these impairments may not be long lasting.
29

Chemo-mechanics of Li-ion batteries: in-situ and operando studies

Luize Scalco De Vasconcelos (9735527) 15 December 2020 (has links)
<div>Electrochemical energy storage devices play an integral role in the energy transition from fossil fuels to renewable. Still, technological breakthroughs are warranted to expand this progress and enable their use where hydrocarbons are still the dominant option. The requirements restricting further adoption of electrochemical devices are related to energy density, hampering costs of raw materials with the increased global demand, and safety in large scale operations. Furthermore, new applications in flexible electronics add new requisites to this list. Pushing these limits involves multidisciplinary efforts where the mechanics are a crucial part.</div><div> </div><div>This thesis explores the mechanical and kinetic behaviors of batteries at the nano to micro-meter scale through operando mechanical and optical characterization during ongoing electrochemical reactions. A unique experimental platform that enables simultaneous nanoindentation and electrochemical testing of active materials is developed. The validity of mechanical testing during operation in the customized liquid cell is systematically addressed. The evolution of the mechanical properties of electrodes as a function of lithium concentration is probed in real-time. This functional dependence between mechanical properties and composition is then used to introduce the concept of mechanics-informed chemical profiling. This new capability enables characterizing transport kinetics in a detailed and quantitative way, including the role of pressure gradients on diffusion. Pairing these experiments with multi-physics modeling led to a new understanding of the mechanisms regulating charging-rate capability and capacity loss in Li-ion batteries. Experiments on composite electrodes showed that liquid electrolytes change the mechanical properties of both conductive matrix and secondary particles. These observations help understand the interactions between the different components of a battery and demonstrate the need for in-situ mechanical characterization capabilities. </div>
30

Inhibition of Human Melonoma Cell Proliferation Using Small Molecule Uracil-DNA Glycosylase Inhibitors

Xiao, Mei, Zhu, Bi Ke, Yu, Lin Jiang 01 March 2008 (has links)
Four known small molecule uracil-DNA glycosylase (UNG) inhibitors were synthesized and tested against human melanoma cells, IgR3 and MM200. They were found to be effective against cell proliferation at micromolar concentrations and to operate through a nonapoptotic mechanism. Thus, small molecules that target UNG may be useful as potential chemotherapeutic agents against human melanoma.

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