29 research outputs found

    De Sitter ground state of scalar-tensor gravity and its primordial perturbation

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    Scalar-tensor gravity is one of the most competitive gravity theory to Einstein's relativity. We reconstruct the exact de Sitter solution in scalar-tensor gravity, in which the non-minimal coupling scalar is rolling along the potential. This solution may have some relation to the early inflation and present acceleration of the universe. We investigated its primordial quantum perturbation around the adiabatic vacuum. We put forward for the first time that exact de Sitter generates non-exactly scale invariant perturbations. In the conformal coupling case, this model predicts that the tensor mode of the perturbation (gravity wave) is strongly depressed.Comment: 9 page

    The mu problem and sneutrino inflation

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    We consider sneutrino inflation and post-inflation cosmology in the singlet extension of the MSSM with approximate Peccei-Quinn(PQ) symmetry, assuming that supersymmetry breaking is mediated by gauge interaction. The PQ symmetry is broken by the intermediate-scale VEVs of two flaton fields, which are determined by the interplay between radiative flaton soft masses and higher order terms. Then, from the flaton VEVs, we obtain the correct mu term and the right-handed(RH) neutrino masses for see-saw mechanism. We show that the RH sneutrino with non-minimal gravity coupling drives inflation, thanks to the same flaton coupling giving rise to the RH neutrino mass. After inflation, extra vector-like states, that are responsible for the radiative breaking of the PQ symmetry, results in thermal inflation with the flaton field, solving the gravitino problem caused by high reheating temperature. Our model predicts the spectral index to be n_s\simeq 0.96 due to the additional efoldings from thermal inflation. We show that a right dark matter abundance comes from the gravitino of 100 keV mass and a successful baryogenesis is possible via Affleck-Dine leptogenesis.Comment: 27 pages, no figures, To appear in JHE

    Study protocol of KLIMOP: a cohort study on the wellbeing of older cancer patients in Belgium and the Netherlands

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    <p>Abstract</p> <p>Background</p> <p>Cancer is mainly a disease of older patients. In older cancer patients, additional endpoints such as quality of survival and daily functioning might be considered equally relevant as overall or disease free survival. However, these factors have been understudied using prospective designs focussing on older cancer patients. Therefore, this study will focus on the impact of cancer, ageing, and their interaction on the long-term wellbeing of older cancer patients.</p> <p>Methods/Design</p> <p>This study is an observational cohort study. We aim to recruit 720 cancer patients above 70 years with a new diagnosis of breast, prostate, lung or gastrointestinal cancer and two control groups: one control group of 720 patients above 70 years without a previous diagnosis of cancer and one control group of 720 cancer patients between 50 - 69 years newly diagnosed with breast, prostate, lung or gastrointestinal cancer. Data collection will take place at inclusion, after six months, after one year and every subsequent year until death or end of the study. Data will be collected through personal interviews (consisting of socio-demographic information, general health information, a comprehensive geriatric assessment, quality of life, health locus of control and a loneliness scale), a handgrip test, assessment of medical records, two buccal swabs and a blood sample from cancer patients (at baseline). As an annex study, caregivers of the participants will be recruited as well. Data collection for caregivers will consist of a self-administered questionnaire examining depression, coping, and burden.</p> <p>Discussion</p> <p>This extensive data collection will increase insight on how wellbeing of older cancer patients is affected by cancer (diagnosis and treatment), ageing, and their interaction. Results may provide new insights, which might contribute to the improvement of care for older cancer patients.</p

    Geriatric oncology: comparing health related quality of life in head and neck cancer patients

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    Background: Population ageing is increasing the number of people annually diagnosed with cancer worldwide, once most types of tumours are age-dependent. High-quality healthcare in geriatric oncology requires a multimodal approach and should take into account stratified patient outcomes based on factors other than chronological age in order to develop interventions able to optimize oncology care. This study aims to evaluate the Health Related Quality of Life in head and neck cancer patients and compare the scores in geriatric and younger patients. Methods. Two hundred and eighty nine head and neck cancer patients from the Oncology Portuguese Institute participated in the Health Related Quality of Life assessment. Two patient groups were considered: the geriatric ( 65 years old, n = 115) and the younger (45-60 years old, n= 174). The EORTC QLQ-C30 and EORTC QLQ-H&N35 questionnaires were used. Results: Head and neck cancer patients were mostly males, 77.4% within geriatric group and 91.4% among younger patients group. The most frequent tumour locations were similar in both groups: larynx, oral cavity and oropharynx - base of the tongue. At the time of diagnosis, most of younger male patients were at disease stage III/IV (55.9%) whereas the majority of younger female patients were at disease stage I/II (83.4%). The geriatric patient distribution was found to be similar in any of the four disease stages and no gender differences were observed. We found that age (geriatrics scored generally worse), gender (females scored generally worse), and tumour site (larynx tumours denounce more significant problems between age groups) clearly influences Health Related Quality of Life perceptions. Conclusions: Geriatric oncology assessments signalize age-independent indicators that might guide oncologic geriatric care optimization. Decision-making in geriatric oncology must be based on tumour characteristics and chronological age but also on performance status evaluation, co-morbidity, and patient reported outcomes assessment.info:eu-repo/semantics/publishedVersio

    Resistance to chemotherapy: new treatments and novel insights into an old problem

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    Resistance to cancer chemotherapeutic treatment is a common phenomenon, especially in progressive disease. The generation of cellular models of drug resistance has been pivotal in unravelling the main effectors of resistance to traditional chemotherapy at the molecular level (i.e. intracellular drug inactivation, detoxifying systems, defects in DNA repair, apoptosis evasion, membrane transporters and cell adhesion). The development of targeted therapies has also been followed by resistance, reminiscent of an evolutionary arms race, as exemplified by imatinib and other BCR-ABL inhibitors for the treatment of chronic myelogenous leukaemia. Although traditionally associated with the last stages of the disease, recent findings with minimally transformed pretumorigenic primary human cells indicate that the ability to generate drug resistance arises early during the tumorigenic process, before the full transformation. Novel technologies, such as genome profiling, have in certain cases predicted the outcome of chemotherapy and undoubtedly have tremendous potential for the future. In addition, the novel cancer stem cell paradigm raises the prospect of cell-targeted therapies instead of treatment directed against the whole tumour

    Comprehensive geriatric assessment in 326 older women with early breast cancer

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    Background: One-third of new early breast cancer diagnoses occur in women over 70 years old. However, older women are less likely to receive radical curative treatments. This study prospectively evaluated a cohort of older women using a Comprehensive Geriatric Assessment (CGA) to determine whether fitness explained the apparent under-treatment in this patient group. Methods: In this multi-centre prospective study, patients aged >= 70 years with Stages I-III breast cancer underwent a pretreatment baseline CGA consisting of eight assessment tools. Patients were defined as 'fit' if they had normal score in seven out of eight of the assessment tools. 'High risk' patients were defined as those with grade 3, ER negative, HER2 positive, or node positive breast cancer. Results: Data on 326 patients were available for full analysis. The median age was 77 years. In all, 182 (56%) of the total population were defined as high risk, with 49%, 61% and 53% of those in the 70-74, 75-84 and >= 85 years age groups respectively having high risk tumours. A total of 301 patients had sufficient CGA records of whom 131 (44%) were reported as fit, with 34%, 54% and 12% of them in the 70-74, 75-84 and >= 85 years age groups respectively. More fit than unfit patients underwent primary breast surgery (100% vs 91%, P = 0.0002), axillary surgery (92% vs 84%, P = 0.0340), and adjuvant chemotherapy for high-risk disease (51% vs 20%, P = 0.0001). Rates of adjuvant radiotherapy after wide local excision were not significantly different (88% vs 90% respectively, P = 0.8195). Conclusions: In this study, all women >= 70 years deemed fit by CGA underwent primary surgery. Nearly 50% of fit women with high-risk disease did not receive adjuvant chemotherapy suggesting under treatment in this group
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