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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.
371

Exploring physical properties of nanoparticles for biomedical applications

Dani, Raj Kumar January 1900 (has links)
Doctor of Philosophy / Department of Chemistry / Viktor Chikan / The research work in this thesis aims at investigating the basic physic-chemical properties of magnetic and metal nanoparticles (NPs) for biomedical applications such as magnetic hyperthermia and controlled drug release. Magneto-plasmonic properties of magnetic NPs are important to evaluate potential applications of these materials. Magnetic property can be used to control, monitor and deliver the particles using a magnetic field while plasmonic property allows the tracking of the position of the particles, but aggregation of NPs could pose a problem. Here, the aggregation of NPs is investigated via the Faraday rotation of gold coated Fe[subscript]2O[subscript]3 NPs in alternating magnetic fields. In addition, the Faraday rotation of the particles is measured in pulsed magnetic fields, which can generate stronger magnetic fields than traditional inductive heaters used in the previous experiments. In the second project, the formation of protein-NPs complexes is investigated for hyperthermia treatment. The interactions between gold and iron-platinum NPs with octameric mycobacterial porin A from Mycobacterium smegmatis (MspA) and MspA[superscript])cys protein molecules are examined to assemble a stable, geometrically suitable and amphiphilic proteins-NPs complex. Magnetic NPs show promising heating effects in magnetic hyperthermia to eliminate cancer cells selectively in the presence of alternating magnetic field. As a part of investigation, the heating capacity of a variety of magnetic NPs and the effects of solvent viscosity are investigated to obtain insight into the heating mechanism of these particles. Finally, the controlled drug release of magnetic NPs loaded liposomes by pulsed magnetic field is investigated. The preliminary data indicate about 5-10% release of drug after the application of 2 Tesla magnetic pulses. The preliminary experiments will serve as the initial stage of investigation for more effective magnetic hyperthermia treatment with the help of short magnetic pulses.
372

Targeted squalenoyl nanomedicines for pancreatic cancer treatment / Nanoparticules à base du squalene pour le traitement ciblé du cancer du pancréas

Valetti, Sabrina 24 March 2014 (has links)
Le cancer pancréatique représente la cinquième cause de décès par cancer dans les pays occidentaux. Son mauvais pronostic (survie à 5 ans inférieure à 3,5 % des cas) est dû à l’absence de facteurs de risques spécifiques interdisant une prévention efficace, et à un diagnostic tardif qui révèle un cancer agressif chez environ 90% des patients. Actuellement, le seul traitement curatif de ce cancer est la chirurgie, mais celle-ci ne peut être envisagée que dans 10 à 15 % des cas. L’adressage de molécules thérapeutiques vers l’organe, le tissu ou la cellule malade constitue aujourd’hui un défi majeur pour le traitement des maladies humaines notamment infectieuses, cancéreuses ou d’origine génétique. C’est pour ces raisons que le développement de nanotechnologies, en tant que vecteurs de médicaments, a pris un essor considérable au cours des dernières années. Dans ce contexte, le concept de squalènisation repose sur le couplage chimique entre le squalène (SQ), un lipide naturel précurseur de la synthèse du cholestérol, et des principes actifs (notamment des molécules anticancéreuses). Les bioconjugués ainsi formés sont alors capables de s’auto-assembler en solution aqueuse pour former des nanoparticules stables de diamètres compris entre 100 et 300 nm. L’exemple de référence dans ce domaine est la nanoparticule de gemcitabine-squalène (SQdFdC) qui a donné lieu à des résultats spectaculaires in vitro sur des lignées de cellules cancéreuses humaines In vivo, les nanoparticules de gemcitabine-squalène se sont avérées beaucoup plus efficaces que la gemcitabine libre sur des tumeurs solides greffées par voie sous-cutanée ainsi que sur des modèles murins de leucémies agressives métastatiques.Au vu de ces résultats encourageants, le projet de thèse a été développé autour de deux axes de recherche. (I) Dans un premier temps, les nanoparticules de gemcitabine-squalène ont été fonctionnalisées par un peptide capable de reconnaître et de cibler spécifiquement les cellules cancéreuses pancréatiques. (II) Le deuxième axe de recherche a visé l’encapsulation d’un second principe actif au sein des nanoparticules de gemcitabine-squalène afin de développer le concept de nanoparticule « multi-thérapeutique ». / Pancreatic cancer is a lethal disease with the worst prognosis among all solid tumors. In the last decades, progresses in pancreatic cancer therapy had remained exceedingly slow and disappointing offering minimal benefits in median survival which remains of less than 6 months and the maximum of 5 years in the 6% of patients. One of the major requirements for a successful cancer therapy is its ability to selectively kill cancer cells with minimal damage to healthy tissues. In this context, a great deal of attention focused on advanced nanoscale systems (i.e., nanomedicines) with the aim to overcome the limits associated to the traditional drug delivery modalities. Nanomedicines can indeed enhance drug properties by (i) offering protection from degradation, (ii) enabling controlled release and distribution and increasing bioavailability while reducing undesired side effects.In the current work we aimed to propose novel nanoscale-based strategies to optimize pancreatic cancer treatment taking into account the specific physio-pathology of this tumor. The first approach relied on the design of a targeted nanomedicine able to specifically bind receptors mainly expressed onto pancreatic cancer cells in order to selectively increase drug accumulation in these cells saving healthy ones.In a second approach, by combining two therapeutic agents in the same nanoparticle we constructed a multi-therapeutic drug delivery system capable to increase the therapeutic index of the combined therapy. In particular, taking advantages from the “squalenoylation prodrug approach”, the research activity of this Ph.D. work lead to the to design of (i) a novel peptide-functionalized squalenoyl gemcitabine nanoparticle and (ii) a tyrosine kinase inhibitor-loaded squalenoyl gemcitabine nanoparticle. Obtained nanoparticles were investigated with respect to their physico-chemical properties and in vitro antitumor activity. The efficacy of peptide-functionalized nanoparticles in impairing tumor growth was assessed in vivo on an experimental model of pancreatic cancer.
373

Exploring appropriate offset values for pencil beam and Monte Carlo dose optimization in lung stereotactic body radiotherapy encompassing the effects of respiration and tumor location

Unknown Date (has links)
Evaluation of dose optimization using the Pencil Beam (PB) and Monte Carlo (MC) algorithms may allow physicists to apply dosimetric offsets to account for inaccuracies of the PB algorithm for lung cancer treatment with Stereotactic Body Radiotherapy (SBRT). 20 cases of Non-Small Cell Lung Cancer (NSCLC) were selected. Treatment plans were created with Brainlab iPlanDose® 4.1.2. The D97 of the Planning Target Volume (PTV) was normalized to 50 Gy on the Average Intensity Projection (AIP) using the fast PB and compared with MC. This exact plan with the same beam Monitor Units (MUs) was recalculated over each respiratory phase. The results show that the PB algorithm has a 2.3-2.4% less overestimation at the maximum exhalation phase than the maximum inhalation phase when compared to MC. Significantly smaller dose difference between PB and MC is also shown in plans for peripheral lesions (7.7 ± 0.7%) versus central lesions (12.7±0.8%)(p< 0.01). / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
374

Phantom Study Incorporating A Diode Array Into The Treatment Planning System For Patient-Specific Quality Assurance

Unknown Date (has links)
The purpose of this research is to accurately match the calculation environment, i.e. the treatment planning system (TPS) with the measurement environment (using a 2-D diode array) for lung Stereotactic Body Radiation Therapy (SBRT) patient-specific quality assurance (QA). Furthermore, a new phantom was studied in which the 2-D array and heterogeneities were incorporated into the patient-specific QA process for lung SBRT. Dual source dual energy computerized tomography (DSCT) and single energy computerized tomography (SECT) were used to model phantoms incorporating a 2-D diode array into the TPS. A water-equivalent and a heterogeneous phantom (simulating the thoracic region of a patient) were studied. Monte Carlo and pencil beam dose distributions were compared to the measured distributions. Composite and individual fields were analyzed for normally incident and planned gantry angle deliveries. The distributions were compared using γ-analysis for criteria 3% 3mm, 2% 2mm, and 1% 1mm. The Monte Carlo calculations for the DSCT modeled phantoms (incorporating the array) showed an increase in the passing percentage magnitude for 46.4 % of the fields at 3% 3mm, 85.7% at 2% 2mm, and 92.9% at 1% 1mm. The Monte Carlo calculations gave no agreement for the same γ-analysis criteria using the SECT. Pencil beam calculations resulted in lower passing percentages when the diode array was incorporated in the TPS. The DSCT modeled phantoms (incorporating the array) exhibited decrease in the passing percentage magnitude for 85.7% of the fields at 3% 3mm, 82.1% at 2% 2mm, and 71.4% at 1% 1mm. In SECT modeled phantoms (incorporating the array), a decrease in passing percentage magnitude were found for 92.9% of the fields at 3% 3mm, 89.3% at 2% 2mm, and 82.1% at 1% 1mm. In conclusion, this study demonstrates that including the diode array in the TPS results in increased passing percentages when using a DSCT system with a Monte Carlo algorithm for patient-specific lung SBRT QA. Furthermore, as recommended by task groups (e.g. TG 65, TG 101, TG 244) of the American Association of Physicists in Medicine (AAPM), pencil beam algorithms should be avoided in the presence of heterogeneous materials, including a diode array. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
375

Sexuell hälsa hos kvinnor efter gynekologisk cancer : En litteraturöversikt / Sexual health of women following gynecological cancer : A literature review

Blom, Sofie, Löfgren, Ellinor January 2019 (has links)
Bakgrund: Varje år insjuknar cirka 3000 kvinnor i gynekologisk cancer i Sverige, vilket innebär cancer i de kvinnliga könsorganen. Behandling mot gynekologisk cancer medför olika fysiska biverkningar. Sexuell hälsa är individuell och påverkas av faktorer som könsroller, njutning, könsidentitet och erotik. Sexuell lust, upphetsning och orgasm är delar av den sexuella hälsan. Sjuksköterskans roll innefattar personcentrerad vård med ett holistiskt perspektiv, där alla aspekter av patientens behov ingår, vilket innefattar den sexuella hälsan. Syfte: Syftet var att belysa upplevelsen av sexuell hälsa hos kvinnor som behandlats för gynekologisk cancer. Metod: Litteraturöversikten baserades på 11 kvalitativa artiklar som inhämtades från databaserna CINAHL Complete, Nursing and Allied health database och PubMed. Artiklarna som valdes att ingå i litteraturöversikten granskades i syfte att tematisera likheter och skillnader. Detta mynnade ut i litteraturöversiktens resultat. Resultat: Resultatet sammanställdes till fyra huvudteman som benämndes; Upplevelsen av ett förändrat sexuellt liv, En förändrad syn på sig själv, Förhållanden och En ny syn på sexuell hälsa. Under Upplevelsen av ett förändrat sexuellt liv identifierades två underteman; Den sexuella lusten och Den sexuella akten. Under En förändrad syn på sig själv identifierades Kvinnlighetens betydelse för kvinnan och Kroppsuppfattning som två underteman. Diskussion: En diskussion har förts kring metoden som användes i litteraturöversikten. Callista Roys adaptionsmodell, tidigare forskning och egna reflektioner har diskuterats i relation till litteraturöversiktens resultat för att stödja samt utöka förståelsen för resultatet. / Background: In Sweden approximately 3000 women fall ill in gynecological cancer each year. Gynecological cancer occurs in women’s genitals. Treatment for gynecological cancer can have different side effects. Sexual health is unique for each individual and is influenced by gender roles, identity, pleasure and erotism. Sexual desire, arousal and orgasm are segments of sexual health. The nurse’s role includes person centered care with a holistic perspective. All aspects of the patient’s needs should be included; therefore, sexual health should not be excluded.  Aim: The aim was to illustrate the experience of sexual health in women who have been treated for gynecological cancer. Method: The literature review was based on 11 qualitative studies collected from CINAHL Complete, Nursing and Allied health database and PubMed. The articles were reviewed in order to find similarities and differences. Results: The results were categorized into four main themes; The experience of a changed sexual life, An altered view on oneself, Relationship and A new view on sexual health. Within The experience of a changed sexual life two subthemes were identified; The sexual desire and The sexual act. Further on, two subthemes were identified in An altered view on oneself; The meaning of womanhood for women and Body image. Discussion: The chosen method for the literature review was discussed. To create understanding and support for the results Callista Roys adaptation model, previous research and our own thoughts were used to discuss the findings of the literature review.
376

Avaliação longitudinal dos ácidos graxos séricos durante tratamento oncológico na neoplasia de esôfago e estômago / Longitudinal evaluation of serum fatty acids in oncological treatment in the esophageal and gastric cancer

Taverna, Lívia Giolo 10 November 2015 (has links)
Introdução: Além do catabolismo protéico acentuado, o paciente com câncer apresenta alterações no metabolismo lipídico. Objetivo: o objetivo do estudo foi avaliar as concentrações séricas de ácidos graxos (AG) antes, durante e após o tratamento oncológico de pacientes com neoplasia de estômago ou de esôfago. Casuística: O estudo prospectivo longitudinal foi conduzido com 14 pacientes com neoplasia de estômago ou de esôfago [62,1 anos (IC95% 55,6-68,6)], sob tratamento oncológico em unidade especializada. O estudo incluiu também 15 voluntários saudáveis [61,0 anos (IC95% 57,1-65,0)]. Métodos: Foram aplicados os questionários de ingestão alimentar (Recordatórios de 24h) e inquéritos relacionados com efeitos adversos e de toxicidade (CTCAE) que potencialmente interferem na ingestão alimentar e no estado nutricional. Foram feitas as medidas antropométricas, a impedância bioelétrica e coleta de sangue para os exames laboratoriais. Os AG foram determinados por cromatografia gasosa e expressos como porcentagem da área total. No Grupo Câncer, os procedimentos foram feitos antes do início, na metade e ao término do tratamento oncológico; o Grupo Controle foi submetido às mesmas avaliações em apenas uma ocasião. A análise estatística foi feita por meio do software Statistica 8.0, usando testes estatísticos não paramétricos. Resultados: As reações adversas relacionadas ao tratamento oncológico foram redução da ingestão de alimentos, saliva espessa com alteração no paladar e náuseas. Antes do início do tratamento, os pacientes com câncer já haviam perdido 17% do peso em relação ao usual; o peso corporal e o IMC reduziram entre a primeira e a terceira avaliação, mas não houve alteração na composição de massa corporal magra e gorda, na ingestão energética e da maioria dos macronutrientes no decorrer do estudo. Em relação ao Grupo Controle, o ácido nervônico foi maior enquanto que os ácidos gama-linolênico e alfalinolênico foram menores no Grupo Câncer. Na avaliação longitudinal, o ácido lignocérico reduziu durante o tratamento oncológico. Conclusão: os pacientes com câncer de esôfago e de estômago apresentam alteração discreta na concentração dos AG séricos em relação aos controles e o tratamento oncológico teve pouco impacto no perfil de AG circulantes / Introduction: In addition to enhanced protein catabolism, the cancer patient has alterations in lipid metabolism. Objective: The objective of the study was to evaluate serum concentrations of fatty acids (FA) before, during and after cancer treatment of patients with gastric or esophageal cancer. Subjects: The prospective longitudinal study was conducted with 14 patients with gastric or esophageal cancer [62.1 years (95% CI 55.6 to 68.6)], under cancer treatment in a specialized unit. The study also included 15 healthy volunteers [61.0 years (95% CI 57.1 to 65.0)]. Methods: The food intake questionnaires were applied (24-hour Dietary Recall) and inquiries related adverse effects and toxicity (CTCAE) that potentially interfere with food intake and nutritional status. Anthropometric measurements were made, the bioelectrical impedance and blood collection for laboratory tests. Gas chromatography determined the FA that was expressed as a percentage of the total area. In Cancer Group, the procedures were done before the start, the middle and at the end of cancer treatment; the control group underwent the same evaluations on only one occasion. Statistical analysis was performed using Statistica 8.0 software, using non-parametric statistical tests. Results: Adverse reactions related to cancer treatment have been reduced food intake, thick saliva with altered taste and nausea. Before the treatment, the patients with cancer had already lost 17% of weight with respect to the usual. Body weight and BMI reduced between the first and the third evaluation, but there was no change in the composition of lean and fat mass, energy intake and macronutrient most during the study. Compared to the control group, the nervonic acid was higher while the gamma-linolenic and alpha-linolenic acids were lower in the cancer group. In the longitudinal evaluation, the lignoceric acid reduced during cancer treatment. Conclusion: Patients with esophageal and stomach cancer have a mild change in the concentration of serum FA compared to controls and cancer treatment had little impact on the current FA profile
377

Investigation of Mathematical Modeling for the general treatment of Glioblastoma

Unknown Date (has links)
The purpose of this research is to validate various forms of mathematical modeling of glioblastoma multiforme (GBM) expressed as differential equations, numerically. The first work was involved in the numerical solution of the reaction-convection model, efficacy of which is expressed in terms of survival time. It was calculated using simple numerical scheme for the standard-of-care treatment in clinics which includes surgery followed by the radiation and chemotherapy. Survival time using all treatment options increased significantly to 57 weeks compared to that of surgery close to 14 weeks. It was also observed that survival time increased significantly to 90 weeks if tumor is totally resected. In reaction-diffusion model using simple numerical scheme, tumor cell density patterns due to variation in patient specific tumor parameters such as net proliferation rate and diffusion coefficient were computed. Significant differences were observed in the patterns while using dominant diffusion and proliferation rate separately. Numerical solution of the tumor growth model under the anti-angiogenic therapy revealed some impacts in optimum tumor growth control however it was not significant. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
378

Anticarcinogenic effects of genistein and anthocyanin extract in MCF-7 human breast cancer cells

Unknown Date (has links)
This study investigated potential apoptotic and anti-proliferative effects of the phytochemicals, genistein and anthocyanin extract, as single and combined treatments in MCF-7 human breast cancer cells. Cells were exposed to single and combined treatments with the phytochemiclas for 48 and 72 hours. Cell viability was assessed using the MTT bioassay. Apoptosis induction was assessed using acridine orange ethidium bromide and rhodamine 123 ethidium bromide fluorescence assays. Both singe and combination treatments induced dose- and time-dependent apoptotic cell death in MCF-7 cells. The percentage of apoptosis was higher in combination treatments than single treatments with either phytochemical, although the difference was not statistically significant. The combination of genistein and anthocyanin extract peaked in efficacy at 48 hours of treatment, to exhibit significantly greater (P<. O5) dose- and time-dependent cell cytotoxicity than single treatments. This study reveals potential chemopreventive implications for the complementary effects of genistein and anthocyanin extract. / by Corine M. Stinson. / Thesis (M.S.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.
379

Empirical beam angle optimization for lung cancer intensity modulated radiation therapy

Unknown Date (has links)
Empirical methods of beam angle optimization (BAO) are tested against the BAO that is currently employed in Eclipse treatment planning software. Creating an improved BAO can decrease the amount of time a dosimetrist spends on making a treatment plan, improve the treatment quality and enhance the tools an inexperienced dosimetrist can use to develop planning techniques. Using empirical data created by experienced dosimetrists from 69 patients treated for lung cancer, the most frequently used gantry angles were applied to four different regions in each lung to gather an optimal set of fields that could be used to treat future lung cancer patients. This method, given the moniker FAU BAO, is compared in 7 plans created with the Eclipse BAO choosing 5 fields and 9 fields. The results show that the conformality index improved by 30% or 3% when using the 5 and 9 fields. The conformation number was better by 12% from the 5 fields and 9% from the 9 fields. The organs at risk (OAR) were overall more protected to produce fewer nonstochastic effects from the radiation treatment with the FAU BAO. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
380

A Feminist Cultural Study of Identity, Hair Loss, and Chemotherapy

Unknown Date (has links)
The main aim of this dissertation is to discuss the way women negotiate the cultural meaning of hair loss, alopecia, as a result of undergoing chemotherapy, and to understand, accordingly, how cancer's cultural effects regarding women can be deeply different from those of men. Very few studies have been done about the cultural impact and resonance of alopecia. It is often regarded as "secondary" to other effects of chemotherapy. Because, in many cultures, head hair for women expresses or manifests attractiveness and power, to be bald is to be deprived of the ability to fit into society, whether in the public or private sphere. The study examines the representation of such women in the media, audience/subject responses to these representations, and interrogates women's identities and representations in terms of Laura Mulvey's theory of the male gaze. Women who have experienced chemotherapy-induced alopec ia were interviewed in this regard. Other contributive feminist, cultural and/or media studies works, such as those by Suzanna Walters, Susan Bordo, Naomi Wolf, Donna Haraway, Stuart Hall, Kimberle Crenshaw, and Judith Butler, help facilitate the analysis. From these perspectives, a historical analysis takes into consideration the symbolic dimension of hair, especially women's head hair, within Western cultural history, particularly in France and a multicultural America. In addition, a textual analysis looks at women, cancer, and hair loss as represented in popular culture characters and personalities. The study insists on the necessity for women to resist to the culture industries and deconstruct the male gaze, as well as the female gaze, which can both contribute to, and perpetuate women's objectification. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

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