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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.
1

Need experienced by persons with late stage aids

Rabbets, Fred C. January 1997 (has links)
Dissertation submitted to the FacuIty ofArts for the Masters degree in Clinical Psychology in the Department of Psychology at the University of Zululand, 1997. / This report documents a qualitative description of the special needs expressed by persons with late stage AIDS in the Richards Bay area. A phenomenological research design and methods were employed to impose rigour on this event. Once the needs of persons with late stage AIDS had been made explicit, these were collated with services rendered or planned through state and welfare structures in the Richards Bay area in an effort to identify salient unfulfilled needs that could be addressed through the establishment of an AIDS Care Centre. This provided important cues regarding the types of services and facilities required at the AIDS Care Centre. Additionally the unstructured interviews employed in the research provided the interviewees with an opportunity to suggest a format of care at the AIDS Care Centre that would be most suitable for them.
2

Late-Stage Breast Cancer Diagnosis Among Haitian Women in the United States

Prosper, Marie-Hortence 01 January 2019 (has links)
Breast cancer is the 2nd leading cause of death among women. While a significant amount of research has been done to understand the different disparities related to this disease, there is still more to learn about the relationship between a person's nationality and the staging of breast cancer. Using the Surveillance, Epidemiology, and End Results Program as the data source, this retrospective cohort study was aimed at assessing late-stage breast cancer among Caribbean immigrants, specifically comparing Haitian women with Americans and other immigrant populations in the United States. The research questions addressed the link between nationality and the likelihood of late-stage breast cancer diagnosis as well as the risk factors associated with an advanced stage of breast cancer. Findings from logistic regression analyses indicated no statistically significant difference in Stage IV diagnosis between women born in Haiti and U.S.-born women, while the converse was true for women born in other foreign countries. The results also suggested that race, Hispanic ethnicity, marital status, insurance coverage, being unemployed, and language isolation were significant predictors of late-stage breast cancer diagnosis (p < 0.05). When stratifying the analyses by nationality, marital status and poverty were the common predictors of advanced breast cancer diagnosis among Haitian, foreign-born, and U.S.-born women. The observed disparities confirm the need for additional efforts that seek to improve screening rates among underserved groups and ultimately reduce the burden of late-stage breast cancer.
3

Development of Catalyst Systems for Regio- and Enantioselective Transformations of Amine and Ether C-H Bonds:

Yesilcimen, Ahmet Selman January 2022 (has links)
Thesis advisor: Masayuki Wasa / This dissertation describes the development of novel catalyst systems that could promote the regio- and enantioselective transformations of C-H bonds contained in N-alkylamines and ethers through Lewis acid-mediated hydride abstraction processes. The progress made in C-H functionalization of N-alkylamines and ethers that served as the intellectual foundation of this dissertation research are summarized in Chapter 1. Despite notable advances, the development of broadly applicable, enantioselective, and catalytic protocols to functionalize C-H bonds in N-alkylamines and ethers with high regio- and stereo-selectivity was regarded as an unsolved problem when we started this dissertation research. In an effort to overcome these fundamental limitations, we first identified a B(C6F5)3/Cu-PyBOX cooperative catalyst system for the enantioselective conversion of a-amino C-H bonds through the generation of an iminium by (F5C6)3B-catalyzed hydride abstraction process (Chapter 2). We then envisioned that in situ generated iminium ions could be further deprotonated to furnish an enamine intermediate, which may react with electrophilic species for a-amino C-H functionalization. The design and development of such a catalyst system were discussed in Chapter 3. Finally, we disclose enantioselective Cu–BOX-catalyzed hetero Diels-Alder reactions of enol ethers generated through Ph3C+-mediated oxidation of alkyl ethers. (Chapter 4). / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
4

Stereoselective Functionalization of Carbonyl Compounds and N-Alkylamines Promoted by Cooperative Catalysts:

Chan, Jessica Zee January 2020 (has links)
Thesis advisor: Masayuki Wasa / This dissertation describes the development of cooperative catalyst systems for the functionalization of monocarbonyl compounds and stereoselective transformations of alpha-C–H bonds of N-alkylamines, inspired by the concepts of frustrated Lewis pairs (FLPs). Prior to this dissertation research, practical and broadly applicable C–C and C–heteroatom bond forming reactions involving the FLP complexes that provide synthetically desirable products with high enantioselectivity remained to be developed. Chapter 1 of this dissertation describes the recent advances in the transformations involving FLPs and B(C₆F₅)₃-catalyzed reactions. Inspired by the unique capability of FLP catalysts to activate otherwise unreactive molecules, and circumvent undesirable acid–base complexation, we have developed potent cooperative acid/base catalysts for C–C bond forming reactions of various monocarbonyl compounds and an appropriate electrophile, which will be discussed in Chapter 2. Another reactivity of FLPs to be explored has to do with the catalytic and enantioselective reactions of N-alkylamines, where two Lewis acid catalysts with potentially overlapping functions, work cooperatively to activate alpha-amino C–H bonds and promote the enantioselective C–C bond forming reaction between N-alkylamines and a nucleophilic species. In Chapter 3, B(C₆F₅)₃-catalyzed union of N-alkylamines and silicon enolates followed by the enantioselective B(C₆F₅)₃/Mg–PyBOX-catalyzed alpha-alkylation of N-alkylamines and alpha,beta-unsaturated compounds to form beta-amino carbonyl compounds will be described. In Chapter 4, B(C₆F₅)₃/Cu–PyBOX-catalyzed alpha-C–H alkynylation of N-alkylamines and the applications in late-stage functionalization and stereoselective synthesis will be discussed. / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
5

The Influence of Social Determinants on Late Stage Breast Cancer and the Impact of the National Breast and Cervical Cancer Program on Late Stage Breast Cancer Diagnosis

Fortune, Melody L 09 December 2011 (has links)
This dissertation research focused on breast cancer and social determinants that have been shown to influence the outcomes of this devastating disease. Although heart disease is the leading cause of death for women, more women feel that they will die from breast cancer. Breast cancer is the most common diagnosed cancer in women exacting an emotional and economic hardship for many women. There are no known causes of breast cancer, but there are certain genetic and social factors that pre-dispose women to this disease. Also, diagnosis at later stages of disease has been shown to have adverse outcomes for many. This research examined the effects that social determinants had on breast cancer stage of diagnosis. The social determinants researched to examine their influence on breast cancer outcomes were race, geographical location, health insurance, and income. Also, this research examined the influence of Public Health Law, 101-354, enacted to decrease health disparity from breast and cervical cancer for minorities and medically underserved women had on breast cancer diagnosis for women enrolled in the Mississippi Breast and Cervical Cancer Program. Complimentary to PHL 101-354, Public Health Law 106-354, the Breast and Cervical Cancer Treatment Act, was enacted giving states the option of providing health insurance through Medicaid for eligible women with a diagnosis of cancer of the breast or cervix, including precancerous conditions, for treatment services. The results of this study revealed that race and health insurance were the two major factors that negatively impacted stages of breast cancer diagnoses. Although hypothesized, geographical location and income did not significantly affect late stage breast cancer rates.
6

Survivability of Planetary Satellites During Uranus-Neptune Ejection

Selan, Nicholas H. 04 December 2008 (has links)
No description available.
7

Adjunctive appliance wear and gender affect patients' oral health-related quality of life during the late stage of orthodontic treatment in adolescents

Dinh, Monica 01 November 2015 (has links)
Objective: This study was conducted to determine how oral health-related quality of life (OHQoL) changes during the late stage of comprehensive fixed orthodontic treatment in adolescents and what factors may be involved. Background: Completion of orthodontic treatment has been shown to improve patients’ OHQoL due to the changes in esthetics, function and emotional well-being. The levels of OHQoL fluctuate throughout treatment where an initial decrease within the first 6 months occurs followed by an improvement towards patients’ pre-treatment levels. At 18 months of fixed orthodontic treatment, the level is unclear. The aims of this study were to clarify the changes of OHQoL during this late stage of fixed orthodontic treatment beyond 18 months in adolescents and to identify factors, including dental extractions, patient compliance, use of adjunctive appliances, and patient demographics, which may contribute to the OHQoL. Methods: This case-control study consisted of 154 adolescent patients undergoing comprehensive fixed orthodontic treatment from the Nova Southeastern University orthodontic department. Subjects were selected based upon the number of months in comprehensive fixed orthodontic treatment. Completion of the Oral Health Impact Profile short form (OHIP-14) as well as occurrence of dental extraction during orthodontic treatment, use of adjunctive appliances, frequency of emergency and failed appointments, level of oral hygiene, and subjects’ age and gender were all recorded. Statistical analysis using structural equation modeling was used to determine the direct and indirect effects to subjects’ OHQoL. Results: The model accounted for 35% of the variance in OHQoL. There were no significant differences in average OHIP-14 scores between the initial stage of 5-7 months and final stage of 18 months and over in orthodontic treatment. The analysis of direct factors showed that females and subjects with adjunctive appliances possessed higher OHIP-14 scores. Conclusions: Treatment time beyond 18 months of treatment was not a significant factor affecting adolescents’ OHQoL. Female patients and those with adjunctive appliances expressed poorer levels of OHQoL. These factors may be attributed to the scores within the physical and psychological domains as these patients experienced pain and discomfort from appliance wear as well as negative impact on their self-esteem during comprehensive fixed orthodontics.
8

ANALYSIS OF LIQUID POOLING DURING LATE-STAGE SOLIDIFICATION

Ashraf, Rameez 10 1900 (has links)
<p>Grain structure and secondary phases play a critical role in determining the mechanical properties of industrial alloys. The spatial variation of such phases is very closely correlated to the liquid pooling established during late stage solidification and grain boundary coalescence. Obtaining a theory that correlates the evolution of length scales during grain boundary coalescence is a critical step toward the optimization of commercial alloys. This thesis highlights various phenomena that enter such a theory. They include coarsening and coalescence of dendrites, nucleation mechanisms and changes in composition of inter-dendritic liquid where second phases tend to initially form. Quantitative phase field models of solidification to simulate casting conditions and microstructure evolution are used in combination with characterization techniques to illustrate the connection between number, size, and distribution of liquid pools. Characterization techniques include spectral analysis, and clustering analysis by way of the Hoshen-Kopleman algorithm. By characterizing late-stage liquid pools, this thesis aims to be a first step towards developing a statistical scaling theory of length scale of liquid pooling.</p> / Master of Applied Science (MASc)
9

Streamlined synthesis of taxol analogues

Rodriguez, Patricia Fernandez January 2017 (has links)
This thesis centres on the synthesis of taxol analogues via late-stage hydroxylation with P450 enzymes. To accomplish this, the taxane core, specifically taxa-4(5),11(12)-dien-2-one, was synthesised by classical synthetic methods, and subsequently oxidised using P450<sub>BM3</sub> mutants. Chapter 1 introduces enzymatic catalysis, and the advantages and disadvantages of its application to organic synthesis. Additionally, an overview of taxol, including its discovery, mode of action, biosynthesis and large-scale production, and a summary of the previously reported approaches to the taxane core are described. Chapter 2 details the problems encountered and solutions implemented when reproducing Baran's route to taxa-4(5),11(12)-dien-2-one. Furthermore, approaches to some of its intermediates and an alternative route to taxa-4(5),11(12)-dien-2-one, which is based on Baran's, are discussed. Chapter 3 describes the development of a new, practical and short synthetic route to taxa-4(5),11(12)-dien-2-one which, ultimately, led to 1,3-di-epi-taxa-4(5),11(12)-dien-2-one. Additionally, the application of this route to the synthesis of a model compound and attempts to convert this racemic synthesis into an enantioselective route are reported. Finally, the enzymatic oxidation of taxa-4(5),11(12)-dien-2-one and related molecules using P450<sub>BM3</sub> mutants is explored in Chapter 4. A preliminary study to determine the substrate enantioselectivity of the mutants is also described, along with the biological assays of the oxidised compounds produced during the study.
10

Synthesis and reactivity of succinylthioimidazolium salts: A unified strategy for the preparation of thioethers

Böhm, Marvin Jeldrik 14 December 2020 (has links)
No description available.

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