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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.
171

Modèles de minimisation d'énergies discrètes pour la cartographie cystoscopique / Discrete energy minimization models for cystoscopic cartography

Weibel, Thomas 09 July 2013 (has links)
L'objectif de cette thèse est de faciliter le diagnostic du cancer de la vessie. Durant une cystoscopie, un endoscope est introduit dans la vessie pour explorer la paroi interne de l'organe qui est visualisée sur un écran. Cependant, le faible champ de vue de l'instrument complique le diagnostic et le suivi des lésions. Cette thèse présente des algorithmes pour la création de cartes bi- et tridimensionnelles à large champ de vue à partir de vidéo-séquences cystoscopiques. En utilisant les avancées récentes dans le domaine de la minimisation d'énergies discrètes, nous proposons des fonctions coût indépendantes des transformations géométriques requises pour recaler de façon robuste et précise des paires d'images avec un faible recouvrement spatial. Ces transformations sont requises pour construire des cartes lorsque des trajectoires d'images se croisent ou se superposent. Nos algorithmes détectent automatiquement de telles trajectoires et réalisent une correction globale de la position des images dans la carte. Finalement, un algorithme de minimisation d'énergie compense les faibles discontinuités de textures restantes et atténue les fortes variations d'illuminations de la scène. Ainsi, les cartes texturées sont uniquement construites avec les meilleures informations (couleurs et textures) pouvant être extraites des données redondantes des vidéo-séquences. Les algorithmes sont évalués quantitativement et qualitativement avec des fantômes réalistes et des données cliniques. Ces tests mettent en lumière la robustesse et la précision de nos algorithmes. La cohérence visuelle des cartes obtenues dépassent celles des méthodes de cartographie de la vessie de la littérature / The aim of this thesis is to facilitate bladder cancer diagnosis. The reference clinical examination is cystoscopy, where an endoscope, inserted into the bladder, allows to visually explore the organ's internal walls on a monitor. The main restriction is the small field of view (FOV) of the instrument, which complicates lesion diagnosis, follow-up and treatment traceability.In this thesis, we propose robust and accurate algorithms to create two- and three-dimensional large FOV maps from cystoscopic video-sequences. Based on recent advances in the field of discrete energy minimization, we propose transformation-invariant cost functions, which allow to robustly register image pairs, related by large viewpoint changes, with sub-pixel accuracy. The transformations linking such image pairs, which current state-of-the-art bladder image registration techniques are unable to robustly estimate, are required to construct maps with several overlapping image trajectories. We detect such overlapping trajectories automatically and perform non-linear global map correction. Finally, the proposed energy minimization based map compositing algorithm compensates small texture misalignments and attenuates strong exposure differences. The obtained textured maps are composed by a maximum of information/quality available from the redundant data of the video-sequence. We evaluate the proposed methods both quantitatively and qualitatively on realistic phantom and clinical data sets. The results demonstrate the robustness of the algorithms, and the obtained maps outperform state-of-the-art approaches in registration accuracy and global map coherence
172

The impact of genetic counselling for familial breast cancer on women's psychological distress, risk perception and understanding of BRCA testing

Elliott, Diana January 2008 (has links)
[Truncated abstract] Background: A review of the literature indicated there was a need for more long-term randomised controlled studies on the effects of BRCA counselling/testing on high risk women, including improved strategies for risk communication. Reviews have also shown women are confused about the significance of inconclusive or non informative results with a need for more research in this area. Aims: The general aim of this study was to evaluate the impact of breast cancer genetic counselling on psychological distress levels, perception of risk, genetic knowledge and understanding of BRCA testing/test results in a cohort of 207 women from high risk breast cancer families who were referred for genetic counselling in Perth during the period 1997 to 2001. Short- and long-term impact of BRCA genetic counselling/testing was determined in women with and without cancer in a randomised controlled trial as part of which women were randomised to either receive immediate versus delayed genetic counselling. This included family communication patterns before BRCA testing, anticipated outcomes of testing on oneself and family including intentions for result disclosure. Comprehension of index and predictive BRCA testing with possible results was assessed both in the short- and the long-term and understanding of individual or family BRCA test results was evaluated at long-term. The effect of genetic counselling on breast cancer risk perception in unaffected women was evaluated. This study considered a theoretical framework of educational learning theories to provide a basis for risk communication with possible relevance for future research. ... Only 25% of the original study population (52/207) reported BRCA results and women's understanding of results is concerning. Key findings were: 1. The majority of affected women received an inconclusive result. 2. Out of twelve unaffected women who reported results, seven were inconclusive which are not congruent with predictive testing. This implies that these women did not understand their test result. 3. A minority of untested relatives did not know whether a family mutation had or had not been found in their tested family member or what their actual test result was. This implies either a lack of disclosure or that woman did not understand the rationale for and significance of testing for a family mutation. 4. Three relatives did not understand a positive result was a mutation. Conclusion: The implication of this research for breast cancer counselling and testing services is that women who wait for counselling are no worse off in terms of short- or long-term general psychological distress than women who receive the intervention early. There is a suggestion that unaffected women without the disease found counselling more advantageous than affected women. The meaning of BRCA results as reported by women is concerning particularly women's understanding of negative and inconclusive results and further research is needed in this area. Too much information presented at counselling may affect women's comprehension of risk, BRCA testing and future test results and further research is required to evaluate the effects of information overload.
173

Cervical cancer screening related knowledge, attitude and behavior: a comparison between South Asian andChinese women in Hong Kong

Gurung, Sharmila. January 2004 (has links)
published_or_final_version / Medical Sciences / Master / Master of Medical Sciences
174

Cervical screening among Southern Alberta First Nations women living off-reserve

Jensen-Ross, Christine, University of Lethbridge. School of Health Sciences January 2006 (has links)
First Nations women face nearly three times the risk of cervical cancer and mortality rates of up to six times higher than their non-Aboriginal counterparts. While cervical cancer is almost completely preventable, Southern Alberta First Nations women seldom access cervical screening services. The purpose of this qualitative focused ethnography was to gain an understanding of the cervical screening needs of un- and under-served First Nations women living off-reserve. Thirteen purposefully selected First Nations women participated in three focus groups utilizing semi-structured interviews. Personal self-worth and cervical screening awareness and relevance are essential to the pursuit of cervical screening. Barriers and incentives for screening and opportunities for acceptability and sustainability are explored. A holistic approach, intersectoral collaboration and cultural safety are described by focus group participants as foundational for optimal service delivery. / xii, 223 leaves ; 29 cm.
175

Análise de tecido mamário neoplásico canino a partir da técnica de difração de Raios X / Canine neoplastic breast tissue analysis using X-ray difraction.

Lopes, Liza Macedo 23 March 2017 (has links)
CAPES / As neoplasias mamárias de canídeos constituem aproximadamente 52% de todas as neoplasias que acometem as fêmeas desta espécie. Atualmente, estudos realizados com tumores mamários humanos têm mostrado que o uso da técnica de difração de raios X possibilita a identificação e diferenciação de estruturas moleculares de tecidos. Porém, são escassos os trabalhos que usam desta técnica para estudar a carcinogênese mamária canina. Com intuito de identificar alterações nas estruturas moleculares de tecidos mamários caninos saudáveis, 101 amostras distribuídas em 26 tecidos normais, 33 tecidos neoplásicos malignos e 42 tecidos neoplásicos benignos conservadas em formol 10% , com laudos prescritos por especialistas, foram submetidas à técnica de difração de raios X. As amostras foram irradiadas no difratômetro de raios X próprio para pó SHIMADZU XRD 7000 composto por uma fonte de raios X de ânodo Cu com energia Kα= 8,04 keV, utilizado no modo reflexão. Os ângulos de incidência dos fótons sobre a amostra variaram de 3° a 37° e com esta variação angular os feixes espalhados pela amostra foram detectados em passos de 1/3 de grau com tempo de contagem de 20 s. Foram aplicados fatores de correção associados ao arranjo experimental com a finalidade de corrigir o perfil de espalhamento medido e possibilitar a identificação de alterações estruturais dos tecidos. A partir das correções foram determinados perfis de espalhamento típicos para cada grupo de amostras e identificadas alterações por meio das posições e intensidade relativa dos picos. Ainda pode-se verificar que os os resultados obtidos neste trabalho apresentaram semelhanças aos encontrados na literatura expondo assim a existência de semelhanças entre tecidos mamários caninos e tecidos mamários humanos. Esta técnica aplicada em neoplasias caninas apresenta potencial para estudo do câncer de mama da humano. / Canine mammary neoplasms represent approximately 52 % of all neoplasms that affect females of this species. Currently studies with human mammary tumors have shown that the use of X-ray diffraction technique allows the identification and differentiation of molecular structures of tissues. However, few studies have used this technique to study canine mammary carcinogenesis. In order to identify alterations in the molecular structures of healthy canine mammary tissues 101 samples distributed among 26 normal tissues, 33 malignant neoplastic tissues and 42 benign neoplastic tissues preserved in 10% formaldehyde, with reports prescribed by specialists, were submitted to a diffraction technique. The samples were irradiated by the SHIMADZU XRD 7000 powder-specific X-ray diffractometer composed of an X-ray anode of Cu with an energy of Kα= 8.04 keV, used in the reflection mode. The angles of incidence of the photons on the sample ranged from 3° to 37° and, with in this angular variation the beams scattered around the sample were detected in steps of a third of degree with a time of counting of 20 seconds. In order to correct the scattering profile provided by the equipment software and to allow the identification of alterations at the molecular level of the tissues submitted to the technique, correction factors associated to the experimental arrangement were calculated. After corrections for each group of samples, were obtained and molecular changes were identified by the peak positions and relative intensity of the peaks. The findings of this work presented similarities to those found in the literature for humans thus suggesting the possibility for ussing canine tissue as a model for diagnostic and therapy studies. This technique applied to canine neoplasias presents a potential for the study of the woman's breast cancer.
176

Optimization of an X-ray diffraction imaging system for medical and security applications / Optimisation d'un système d'imagerie en diffraction X pour des applications médicales et en contrôle de sécurité

Marticke, Fanny 19 July 2016 (has links)
L’imagerie basée sur la diffraction des rayons X est une technique non-invasive puissante pour l’identification et caractérisation de matériaux différents. Comparée aux techniques traditionnelles utilisant la transmission des rayons X, elle permet d’extraire des informations beaucoup plus caractéristiques pour le matériau inspecté, comme les positions des pics de Bragg pour des matériaux cristallins et le facteur de forme moléculaire pour les matériaux amorphes. Le potentiel de cette méthode a été reconnu par de nombreuses équipes de recherche et de nombreuses applications comme l’inspection de bagage, le contrôle non-destructif, la détection de drogue et la caractérisation de tissus biologiques ont été proposées. La méthode par dispersion d’énergie (EDXRD) est particulièrement adaptée à ce type d’application car elle permet l’utilisation d’un tube à rayons X conventionnel, l’acquisition du spectre entier en une fois et des architectures parallélisées pour l’inspection d’un objet entier en un temps raisonnable. L’objectif de ce travail est d’optimiser toute la chaîne de caractérisation. L’optimisation comprend deux aspects : l’optimisation du système d’acquisition et du traitement des données. La dernière concerne particulièrement la correction des spectres de diffraction dégradés par le processus d’acquisition. Des méthodes de reconstruction sont proposées et validées sur des spectres simulés et expérimentaux. L’optimisation du système est réalisée en utilisant des facteurs de mérite comme l’efficacité quantique de détection (DQE), le rapport contraste sur bruit (CNR) et les courbes de caractéristiques opérationnelles de réception (ROC).La première application choisie, c’est l’imagerie du sein basée sur la diffraction qui a pour but de distinguer des tissus cancéreux des tissus sains. Deux configurations de collimation sans multiplexage combinant EDXRD et ADXRD sont proposées suite au processus d’optimisation. Une étude de simulation du système entier et d’un fantôme de sein a été réalisée afin de déterminer la dose requise pour la détection d’un petit carcinome de 4 mm. La deuxième application concerne la détection de matériaux illicites pendant le contrôle de sécurité. L’intérêt possible d’un système de collimation multiplexé a été étudié. / X-ray diffraction imaging is a powerful noninvasive technique to identify or characterize different materials. Compared to traditional techniques using X-ray transmission, it allows to extract more material characteristic information, such as the Bragg peak positions for crystalline materials as well as the molecular form factor for amorphous materials. The potential of this technique has been recognized by many researchers and numerous applications such as luggage inspection, nondestructive testing, drug detection and biological tissue characterization have been proposed.The method of energy dispersive X-ray diffraction (EDXRD) is particularly suited for this type of applications as it allows the use of a conventional X-ray tube, the acquisition of the whole spectrum at the same time and parallelized architectures to inspect an entire object in a reasonable time. The purpose of the present work is to optimize the whole material characterization chain. Optimization comprises two aspects: optimization of the acquisition system and of data processing. The last one concerns especially the correction of diffraction pattern degraded by acquisition process. Reconstruction methods are proposed and validated on simulated and experimental spectra. System optimization is realized using figures of merit such as detective quantum efficiency (DQE), contrast to noise ratio (CNR) and receiver operating characteristic (ROC) curves.The first chosen application is XRD based breast imaging which aims to distinguish cancerous tissues from healthy tissues. Two non-multiplexed collimation configurations combining EDXRD and ADXRD are proposed after optimization procedure. A simulation study of the whole system and a breast phantom was realized to determine the required dose to detect a 4 mm carcinoma nodule. The second application concerns detection of illicit materials during security check. The possible benefit of a multiplexed collimation system was examined.
177

The experience of African women diagnosed with both HIV/AIDS and cervical cancer

Maboko, Emmanuel 03 1900 (has links)
This qualitative study explored and described the experience of African women diagnosed with both HIV/AIDS and cervical cancer in order to gain an understanding of the experience of both illnesses as lived by these women. Phenomenological research methods were employed using in-depth semi-structured interviews. Communication as a strategy facilitating diagnosis, disclosure, acceptance and support for women with HIV/AIDS and cervical cancer emerged as the main theme, followed by the experience of physical symptoms and emotional experiences. The study shows the importance of communication in the management and support of these women attending public health institutions and in the community. For communication to occur the relationship between healthcare professionals and women diagnosed with HIV/AIDS and cervical cancer is very important. Treatment approaches in radiation therapy need to be developed for women diagnosed with HIV/AIDS and cervical. More research is needed in this area (HIV/AIDS and cervical cancer). / Health Studies / M.A. (Public Health)
178

A mixed method approach on the perspectives of cervical cancer screening in Makhuduthamaga sub-district, Sekhukhune district, Limpopo Province, South Africa

Makunyane, Coshiwe Matildah 02 1900 (has links)
Cervical cancer remains the leading cause of cancer mortality among women worldwide, a burden in the developing countries and commonly detected through symptoms at later invasive stages. The study aimed at establishing knowledge and awareness of the importance of cervical cancer screening in the Makhuduthamaga Sub-district by exploring the perceptions of women and professional nurses and through the review of the National Cervical Cancer Screening Policy (2013). Recommendations to address the gap in knowledge and to inform the National Cervical Cancer Screening Policy were developed based on the study findings. A mixed-method approach was used in this study through a sequential explanatory design, which is quantitatively driven was used. Quantitative data were obtained by using a researcher developed checklist. The checklist was developed from variables stated in the National Cervical Cancer Screening Policy and was used to review its implementation. Qualitative data was obtained through in-depth interviews with individual women and focus group discussions with professional nurses. The study was conducted in ten randomly selected clinics of Makhuduthamaga Sub-district. Purposive sampling was done to obtain qualitative data. An average score of 9.7 was obtained for all ten clinics that participated in the study with regard to the evaluation of the implementation of the National Cervical Cancer Screening Policy. Only 6 (60%) clinics implemented the policy whereas 4 (40%) clinics did not implement the policy. Women and professional nurses perceived cervical cancer screening as important. Lack of knowledge among women regarding cervical cancer screening contributed to the majority of women not screening for cervical cancer. Lack of resources, the 10 year interval of normal cervical cancer screening, the use of disposable vaginal speculums and brushes, lack of standardized cervical cancer screening training, centralization of cytology laboratories came out as factors that negatively influence the uptake of cervical cancer screening. Cervical cancer screening awareness campaigns, availability of resources and standardized in-service trainings on cervical cancer screening were recommended to enhance the cervical cancer screening uptake. / Health Studies / D. Litt. et Phil. (Health Studies)
179

Knowledge of cervical cancer and awareness of screening regimes/routines among HIV positive women in Swaziland

Chili, Thembisile 02 1900 (has links)
Background Cervical cancer is one of the common cancers worldwide. Despite the available screening services, the uptake of cancer of the cervix is very low. The incidence and mortality in western countries has reduced greatly due to the introduction of cervical cancer screening programmes. However, this is not the same in Africa where cervical cancer is more prevalent in lower resource countries to lack of access to effective screening and services that enhances early detection and treatment. Purpose/Aim of the study The purpose of this research is to determine knowledge of cervical cancer and the level of awareness of screening regimes/routines among HIV positive women in Swaziland. The study was conducted at one hospital specifically at the HIV Care Unit and Public Health Unit between January and June 2015. Methods The questionnaire was administered to collect data and consisted both open and close-ended questions. The questionnaire comprises of three sections: Section A: Socio-demographic data and Section B: Awareness on Cervical Cancer. Section C: Awareness/knowledge on cervical cancer screening. The sample consisted of 123 HIV positive who are on antiretroviral therapy (ART) or ART naive. The mean age for the respondents was 35 years. Results From this study, N=28 (23%) out of 123 (77%) reported to have received annual Pap smear for cervical cancer screening. A low proportion of the respondents (45%) had knowledge on cervical cancer screening. In addition, 63% of those who got information about cervical cancer screening through the radio perceived themselves to be at risk of getting cervical cancer. Only 4% heard about cervical cancer at the ART clinic, despite having been followed up for their care at the HIV clinic. Those who screened for cervical cancer were younger in age 25-34 years (80%). This study also revealed that education increased the changes of a woman to be screened for cervical cancer. If a woman had a university or high school education, she perceived herself to be at risk of getting cervical cancer. Conclusion Knowledge is power, cervical cancer campaigns should be conducted at national level in order to promote prevention through screening. Cervical cancer screening should be fully integrated into HIV services / Health Studies / M.A. (Public Health)
180

Perceptions, knowledge and attitudes of women undergoing cervical cancer screening in Omaheke, Namibia

Zengwe, Sithembiso 02 1900 (has links)
Text in English / The purpose of the study was to explore perceptions, knowledge and attitudes of women undergoing cervical cancer screening in Omaheke, Namibia. A qualitative exploratory study was conducted. Data were collected from a purposive sample of eight participants using a self-developed interview guide. Data were analysed using Tesch’s descriptive method of open coding. Three themes were identified namely; cervical cancer as a disease, perception of cervical cancer and service delivery at the facility. The findings also revealed some suggestions for the facility that could improve screening uptake. The study proposes a community education programme on cervical cancer and related topics to be covered during health education sessions. In addition the study recommends the Omaheke directorate to look into operational issues in order to facilitate access to cervical cancer screening. / Health Studies / M.P.H.

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