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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.
241

Synthèse et évaluation biologique de dérivés hétérocyliques comme agents anti-cancéreux / Synthesis, biological evaluation of heterocyclic derivatives as anti-cancer agents

Do, Cong Viet 18 June 2013 (has links)
La combrétastatine A-4 est un produit naturel isolé d'un arbuste africain Combretum caffrum et qui possède de très intéressantes propriétés biologiques: inhibition de la polymérisation de la tubuline et propriétés antiprolifératives auprès de nombreuses cellules tumorales. Malheureusement, ce produit possède de propriétés pharmacocinétiques non optimales qui limitent son application clinique. Par conséquent de nombreux dérivés synthétiques ont été testés et parmi ceux-ci, l'isocombrétastatine A-4 (isoCA-4). Dans notre travail de thèse, nous avons donc synthétisé des analogues de l'isoCA-4 dont un des cycles aromatiques a été remplacé par des hétérocycles thiophènes et benzothiophènes diversement substitués. Certains de ces produits ont montré des activités du même ordre que la colchicine, substance de référence sur la polymérisation de la tubuline, et sur la prolifération de cellules mélanocytaires IC8. Les composés présentant une structure benzo[b]thiophène montrent une meilleure activité que ceux ayant une simple structure thiophène. De plus, les composés portant une chaine latérale en position 2 montrent une activité supérieure à ceux substitués en position 3.D'autre part, les stuctures indénoindoles sont connues comme étant de puissants inhibiteurs de la caséine kinase 2 (CK2), celle-ci joue un rôle important dans de nombreux processus cellulaires. A partir de cette structure indénoindole et, en utilisant une stratégie proche de celle utilisée pour la série précédente (par introduction d'un atome d'iode en position ortho et cyclisation pallado-catalysée), nous avons synthétisé des analogues indénohétérocycliquesen remplaçant le noyau indolepar des noyauxthiophèneetbenzo[b]thiophène. L'activité inhibitrice de ces dérivés vis-à-vis de la CK2 a été évaluée et l'un de ces composés a montré une forte activité / Isocombretastatin A-4 (isoCA-4), a modified combretastatin A-4 (CA-4), was recently discovered known as a strong activity compound to inhibit tubulin polymerization. The vinyl derivatives opened a new series which is hardly exploited. Based on the structure of isoCA-4, we synthesized isoheterocycles series by replacing the B-ring of isoCA-4 by thiophene and benzo[b]thiophene derivatives. These two series were evaluated in their ability to inhibit tubulin assembly. The benzo[b]thiophene derivativesshowed better activity than thiophene derivatives, the binding position 2 of benzo[b]thiophene showed higher activity than position 3. Indenoindoles was known as a potent series to inhibit casein kinase 2 which plays important role in many processes in cell. Based on the structure of indenoindole, we synthesized indenoheterocycles by replacing indole by thiophene and benzo[b]thiophene derivatives. These two series were evaluated in their ability to inhibit CK2. One of the compoundsshowed high activity
242

Regulation of ΔNp63α by TIP60 promotes cellular proliferation

Stacy, Andrew Jared 07 August 2020 (has links)
No description available.
243

Modelo tecnológico para el soporte al diagnóstico de lesiones cutáneas del tipo melanoma usando reconocimiento de imágenes / Technological model to support the diagnosis of skin lesions of the melanoma type using image recognition

Campos Poma, Jonathan Miguel, De La Cruz Dominguez, Emily Yanira 14 May 2021 (has links)
El cáncer de piel es el tipo de cáncer más común en todo el mundo. Más de 65.000 personas mueren cada año, por culpa de este cáncer de piel y cada año se diagnostican más de 13 millones de casos de cáncer de piel. En Perú es el cuarto tipo de cáncer con mayor incidencia en el país y anualmente 1200 peruanos son detectados con cáncer de la piel. Las regiones con mayores casos de cáncer de la piel son: Lima 45.9%, La Libertad 13.2%, Lambayeque 7.5%, Cajamarca 4.9%, Junín con 3.1% y otras regiones 25.4% (Sausa, 2017). Además, el 85% de los 130 especialistas oncológicos están concentrados en la capital y en algunas regiones no hay ninguno. En este proyecto se propone un modelo tecnológico para la detección temprana de cáncer de piel. Se busca reducir el tiempo de espera en la obtención de un diagnóstico, además, se ha digitalizado la función del dermatoscopio mediante el uso de Smartphone y lentes de aumento como accesorio del dispositivo móvil. El modelo propuesto está conformado por cinco fases: 1. Entrada. 2. Captura. 3. Canal. 4. Análisis y procesamiento. 5. Visualización. 6. Salida 7. Soporte. Este modelo fue validado en un grupo de 60 pacientes, donde 12 sufren de cáncer piel en etapa tardía, 28 en etapa temprana y 20 son pacientes sanos, en una red de clínicas de Lima, Perú. El resultado obtenido fue 97% de asertividad sobre las lesiones cutáneas analizadas y 90 % en los pacientes sanos (Campos Poma, De La Cruz, Armas-Aguirre, & Gutiérrez González, 2020). / Skin cancer is the most common type of cancer in the world. More than 65,000 people die each year because of this skin cancer and more than 13 million cases of skin cancer are diagnosed each year. In Peru is the fourth cancer with the highest incidence in the country and in the country 1200 Peruvians are detected with skin cancer. major: cases of skin cancer: Lima 45.9%, La Libertad 13.2%, Lambayeque 7.5%, Cajamarca 4.9%, Junin with 3.1% and other regions 25.4% (Sausa, 2017). In addition, 85% of the 130 specialists Oncologists are concentrated in the capital and in some regions, there are none. In this project, we proposed a technological model for the early detection of skin cancer. The purpose is reduce the waiting time to obtaining a diagnosis, in addition, the function of the dermatoscope has been digitized by using a Smartphone and magnifying lenses as an accessory the mobile device. The proposed model has five phases: 1) Input. 2) Screenshot. 3) Channel. 4) Analysis and processing. 5) Display. 6) Ouput. 7) Support. This model was validated in a group of 60 patients, where 12 suffer from skin cancer int the late stage, 28 un the early stage and 20 are healthy patients, in a network of clinics in Lima, Peru. The obtained result was 97% of assertiveness on the analyzed skin lesions and 90% in healthy patients (Campos Poma, De La Cruz, Armas-Aguirre, & Gutiérrez González, 2020). / Tesis
244

Estrogen receptor involvement in the response of human keratinocytes to ultraviolet B irradiation

Farrington, Daphne L. January 2014 (has links)
The signaling mechanisms involved in UVB-induced skin cancer are complex and although the scope of this work is inherently limited in focus, the findings may provide insight into how estrogen receptor signaling impacts cell growth, senescence, and apoptosis to protect keratinocytes. Additional signaling due to E2-activation of the estrogen receptor may provide back-up or redundant pathways in response to UVB.
245

”Ovisshet är det värsta som finns” : Ett förbättringsarbete som syftar till att förkorta svarstider för hudcancerdiagnostik och en kvalitativ studie kring kvalitet som strategi / “Uncertainty is the worst thing in the world” : An improvement project aimed to shorten the response times for skin cancer diagnosis and a qualitative study on quality as a strategy

Trabelsi, Felicia January 2023 (has links)
Cancer är den näst vanligaste dödsorsaken globalt och står för uppskattningsvis 9,6 miljoner dödsfall varje år, eller var sjätte dödsfall totalt sett. Detta innebär en enorm börda för de människor som drabbas. Allt fler överlever många typer av cancer tack vare tidig upptäckt och snabbt fastställande av diagnos. Hudcancer är efter prostatacancer den näst vanligaste cancerdiagnosen i Sverige och behovet för att ta hudbiopsier har därmed ökat till följd av mycket solande hos invånare.  Patologilaboratoriet i Jönköpings län har under 2020 till 2022 haft en långsamt växande kö av hudprover på grund av brist på patologer och att samarbete med extern underleverantör löpte ut. Syftet med förbättringsarbetet är att hitta sätt att förkorta svarstider för hudprover.  Region Jönköpings län har valt att använda sig av kvalitet som strategi för sin organisationsutveckling. Ambitionen är att värderingarna kring kvalitet ska genomsyra hela organisationen. För att lyckas med förbättringsarbeten krävs det att medarbetare både har fått kunskap och förutsättningar för att tillsammans driva verksamheten framåt.  Syftet med studien var att belysa medarbetares drivkrafter bakom ett framgångsrikt kvalitetsarbete och identifiera vilka strategier som leder till detta. Hörnstensmodellen tillämpas för att dra slutsatser kring resultatet och metoden är kvalitativ. Semistrukturerade intervjuer av medarbetare genomfördes.   Förbättringsarbetets resultat illustreras med hjälp av kvantitativ data och SMARTA målet uppnås redan innan slutdatum. Studien visar att det finns flera faktorer som är viktiga för att uppnå ett framgångsrikt kvalitetsarbete. Både engagerat ledarskap och medarbetares möjlighet till delaktighet är avgörande faktorer för att lyckas med kvalitet som strategi inom organisationer. Utöver detta är arbetet med att sätta upp mål en viktig strategi för att lyckas. Vidare kan studiens resultat användas i det fortsatta kvalitetsarbetet både inom verksamheten och utanför. / Cancer is the second largest leading cause of death globally and causes an estimated 9.6 million deaths each year, or one in six deaths in total. This means an enormous burden for the people affected. More and more people are surviving many types of cancer thanks to early detection and rapid diagnosis. Skin cancer is after prostate cancer the second most common cancer diagnosis in Sweden, and the need to take skin biopsies has increased due to a lot of sunbathing among residents.  From 2020 to 2022, the pathology laboratory in Jönköping County has had a slowly increasing queue of skin cancer samples due to a lack of pathologists and the fact that collaboration with an external subcontractor expired. The purpose of the improvement work is to find ways to shorten the response times for skin samples.  The County of Jönköping has chosen to use quality as strategy for its organizational development. The ambition is for the values around quality to permeate the entire organization. In order to succeed with improvement work, it is necessary that employees have both gained knowledge and that they have conditions to focus on improvement work.  The aim of the study is to shed light on employees' driving forces behind a successful work on quality and to identify which strategies lead to this. The “cornerstone model” is applied to draw conclusions on the findings while the method of the study is a qualitative one. Semi-structured interviews with employees were conducted.  The results of the improvement work are illustrated with the help of quantitative data and the goal is achieved before the deadline. The study shows that there are several factors that are important for achieving a successful quality work. Both leadership and employees’ opportunities to participate are decisive factors for success with quality as a strategy within organizations. In addition to this, the work of setting goals is an important strategy for success. The results of the study can be used in the continued quality improvement work both within the unit and outside.
246

A Comparison of Convolutional Neural Networks used in Melanoma Detection : With transfer learning on the PAD-UFES-20 and ISIC datasets

Gobena, Abdi January 2023 (has links)
Skin cancer is one of the most common forms of cancer, of which melanoma is the most lethal. Early detection is critical to long term survival rates. The use of machine learning to detect melanoma shows promising results in detecting malignant forms. The use of melanoma detecting models could potentially lead to faster diagnosis, and ensure treatment is applied before the melanoma has spread to other organs. In recent years, many studies have been made on the topic, especially on larger datasets such as ISIC, but there is a lack of studies on how machine learning perform on datasets containing smartphone images of skin lesions. PAD-UFES-20 is a dataset containing 2298 smartphone images of skin lesions, where the malignant forms are all clinically confirmed. The purpose of this thesis was to produce a comparison of the accuracy, precision, recall, and Area under the Curve metrics for several convolutional neural network models that were trained on the PAD-UFES-20 and ISIC datasets to differentiate between melanoma and benign lesions. The goal of this project is to contribute to the knowledge surrounding how neural networks perform in terms of melanoma detection. This is of interest for anyone getting started in the domain of melanoma detection using machine learning, building a melanoma detection application, and for anyone benefiting from earlier diagnosis. A qualitative and inductive approach with the support of quantitative data was adopted. Eight models were selected. They were designed using transfer learning, where the base model acted as a feature extractor, providing input to a dropout layer, and finally to the classification layer, which was retrained for 50 epochs, using the ADAM optimizer with a learning rate of 0.0003. These models were then evaluated against a test set for accuracy, precision, recall and AUC. The results of this study showed that the best performing models in terms of detecting melanoma on the PAD-UFES-20 dataset were Resnet_v2_50 and Mobilenet_v3_Large. Resnet_v2_50 achieved an accuracy of 0.9062, precision of 0.8, recall of 0.6667 and AUC of 0.8846. Mobilenet_v3_Large achieved accuracy of 0.9062, precision of 0.8, recall of 0.6667 and AUC of 0.9295. The best performing model on the ISIC dataset was the Inception_Resnet_v2 model with accuracy of 0.9342, precision of 0.9627, recall of 0.9018 and AUC of 0.9675. The conclusions of this study show that several models achieve promising results on the PAD-UFES-20 dataset. Overall, models that extracted a larger number of features from the base model performed better on the PAD-UFES-20 dataset, whereas this was not the general case on the larger ISIC dataset. It is not too futuristic to claim that machine learning can be applied as complement to standard diagnosis, but the study highlights the need for similar studies on larger and more diverse datasets of smartphone images, from which more transferable results can be obtained. / Hudcancer är en av de vanligaste formerna av cancer, där melanom är den mest dödliga. Tidig upptäckt är avgörande för långsiktiga överlevnadschanser. Användning av maskininlärning för att upptäcka melanom visar lovande resultat i att upptäcka maligna former av hudskador. Användning av modeller för att upptäcka melanom kan potentiellt leda till snabbare diagnos och säkerställa att behandling tillämpas innan melanomet har spridit sig till andra organ. De senaste åren har många studier gjorts inom ämnet, särskilt på större datamängder såsom ISIC datamängden, men det saknas studier om hur maskininlärning presterar på datamängder som innehåller smarttelefonbilder av hudskador. PAD-UFES-20 är en datamängd som innehåller 2298 smarttelefonbilder av hudskador, där de maligna formerna alla är kliniskt bekräftade. Syftet med denna studie var att producera en jämförelse av noggrannhet, precision, recall och Area under the Curve måtten för flera faltnings neuronnätverksmodeller som tränades på PAD-UFES-20 och ISIC-dataseten för att skilja mellan melanom och godartade hudskador. Målet med denna studie är att bidra till kunskapen om hur neurala nätverk presterar när det gäller upptäckt av melanom. Detta är av intresse för alla som börjar inom området för upptäckt av melanom med hjälp av maskininlärning och för alla som gynnas av en tidigare diagnos. En kvalitativ och induktiv ansats med stöd av kvantitativa data antogs. Åtta modeller valdes. De designades med hjälp av överföringsinlärning, där basmodellen fungerade som en producent av funktioner, som gav inmatning till ett Dropout lager och slutligen till klassificeringslagret, som tränades i 50 epoker, med hjälp av ADAM-optimeraren med en inlärningshastighet på 0.0003. Dessa modeller utvärderades sedan mot en test mängd för noggrannhet, precision, recall och AUC. Resultaten av denna studie visade att de bästa presterande modellerna när det gäller att upptäcka melanom på PAD-UFES-20-datasetet var Resnet_v2_50 och Mobilenet_v3_Large. Resnet_v2_50 uppnådde en noggrannhet på 0.9062, precision på 0.8, recall på 0.6667 och AUC på 0.8846. Mobilenet_v3_Large uppnådde noggrannhet på 0.9062, precision på 0.8, recall på 0.6667 och AUC på 0.9295. Den bäst presterande modellen på ISIC-datasetet var Inception_Resnet_v2-modellen med noggrannhet på 0.9342, precision på 0.9627, recall på 0.9018 och AUC på 0.9675. Slutsatserna av denna studie visar att flera modeller uppnår lovande resultat på PAD-UFES-20-datasetet. Sammantaget, presterade modeller som extraherade ett större antal funktioner från basmodellen, bättre på PAD-UFES-20-datasetet, medan detta inte var det generella fallet på det större ISIC-datasetet. Det är inte för långsökt att hävda att maskininlärning kan tillämpas som komplement till standarddiagnos metoder, men denna studie framhäver behovet av liknande studier på större och mer diversifierade datamängder av smarttelefonbilder, från vilka mer överförbara resultat kan erhållas.
247

Non-Invasive Skin Cancer Classification from Surface Scanned Lesion Images

Dhinagar, Nikhil J. 12 June 2013 (has links)
No description available.
248

Preventing Skin Cancer in Adolescent Girls Through Intervention with Their Mothers

Baker, Mary K 01 May 2013 (has links) (PDF)
Indoor tanning (IT) before the age of 35 increases one’s risk for melanoma by 75%, and epidemiological data show a 6.1% annual increase in the incidence of melanomas in white women younger than age 44 in the US. Population-based studies reveal that 15% of adolescents and 8% to 14% of their primary caregivers have engaged in IT in the past year. The compelling case for IT being a significant risk factor for melanoma, together with the high rates of IT in teen girls and their mothers, provided a strong rationale for conducting an antitanning intervention directed at mother-daughter dyads. This study evaluated a strategy designed to prevent skin cancer in adolescent girls by using mothers as change agents to effectively communicate the risks of IT and to encourage teens to avoid high risk IT behaviors. Mother-daughter dyads were recruited over the telephone, randomly assigned to the intervention or control group, and surveyed on IT risk constructs including tanning-specific knowledge and communication. Forty-two mother-daughter dyads completed baseline surveys in the summer of 2012. Mothers in the intervention group were given a handbook educating them on the dangers of IT and how to convey information about skin cancer prevention to their daughters and encouraged to talk with their daughters about the issues covered in the handbook over a 1-month period. Participants completed follow-up assessments in October 2012 and January 2013. Among teens, past 3-month IT frequency, intentions, and willingness decreased in intervention group teens, while intentions and willingness increased among control teens. Intervention teens exhibited lower IT attitudes and higher levels of perceived susceptibility to appearance damage and health effects from IT when compared to control teens. Intervention teens reported higher levels of maternal monitoring and lower levels of maternal permissiveness toward IT. Qualitative data indicated mothers responded positively to the handbook, and it encouraged tanning-specific discussions with their daughters. Mothers provided suggestions on how to improve the handbook, that once incorporated, should lead to improved intervention efficacy. Overall, study results indicated this intervention strategy is feasible, as mothers did communicate with their teens and were able to convey the antitanning messages.
249

Design, Synthesis, and Biological Evaluation of Melanocortin-1-Receptor Agonists for the Prevention of Skin Cancer

RUWE, ANDREW R. 24 September 2008 (has links)
No description available.
250

Delineating ΔNp63α's function in epithelial cells

Sakaram, Suraj January 2016 (has links)
No description available.

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