77 research outputs found

    Retrieval study of cool, directly imaged exoplanet 51 Eri b

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    Retrieval methods are a powerful analysis technique for modelling exoplanetary atmospheres by estimating the bulk physical and chemical properties that combine in a forward model to best-fit an observed spectrum, and they are increasingly being applied to observations of directly-imaged exoplanets. We have adapted TauREx3, the Bayesian retrieval suite, for the analysis of near-infrared spectrophotometry from directly-imaged gas giant exoplanets and brown dwarfs. We demonstrate TauREx3's applicability to sub-stellar atmospheres by presenting results for brown dwarf benchmark GJ 570D which are consistent with previous retrieval studies, whilst also exhibiting systematic biases associated with the presence of alkali lines. We also present results for the cool exoplanet 51 Eri b, the first application of a free chemistry retrieval analysis to this object, using spectroscopic observations from GPI and SPHERE. While our retrieval analysis is able to explain spectroscopic and photometric observations without employing cloud extinction, we conclude this may be a result of employing a flexible temperature-pressure profile which is able to mimic the presence of clouds. We present Bayesian evidence for an ammonia detection with a 2.7σ\sigma confidence, the first indication of ammonia in an exoplanetary atmosphere. This is consistent with this molecule being present in brown dwarfs of a similar spectral type. We demonstrate the chemical similarities between 51 Eri b and GJ 570D in relation to their retrieved molecular abundances. Finally, we show that overall retrieval conclusions for 51 Eri b can vary when employing different spectral data and modelling components, such as temperature-pressure and cloud structures

    ARES. III. Unveiling the Two Faces of KELT-7 b with HST WFC3*

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    We present the analysis of the hot-Jupiter KELT-7 b using transmission and emission spectroscopy from the Hubble Space Telescope, both taken with the Wide Field Camera 3. Our study uncovers a rich transmission spectrum that is consistent with a cloud-free atmosphere and suggests the presence of H_{2}O and H^{−}. In contrast, the extracted emission spectrum does not contain strong absorption features and, although it is not consistent with a simple blackbody, it can be explained by a varying temperature–pressure profile, collision induced absorption, and H^{-}. KELT-7 b had also been studied with other space-based instruments and we explore the effects of introducing these additional data sets. Further observations with Hubble, or the next generation of space-based telescopes, are needed to allow for the optical opacity source in transmission to be confirmed and for molecular features to be disentangled in emission

    Surgical treatment of primitive gastro-intestinal lymphomas: a systematic review

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    Primitive Gastrointestinal Lymphomas (PGIL) are uncommon tumours, although time-trend analyses have demonstrated an increase. The role of surgery in the management of lymphoproliferative diseases has changed over the past 40 years. Nowadays their management is centred on systemic treatments as chemo-/radio- therapy. Surgery is restricted to very selected indications, always discussed in a multidisciplinary setting. The aim of this systematic review is to evaluate the actual role of surgery in the treatment of PGIL

    Brain metastases in gastro-oesophageal adenocarcinoma: Insights into the role of the human epidermal growth factor receptor 2 (HER2)

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    Background: Gastro-oesophageal adenocarcinomas rarely metastasize to the central nervous system (CNS). The role of the human epidermal growth factor receptor 2 (HER2) in patients with these cancers and CNS involvement is presently unknown.Patients and Methods: A multicentre registry was established to collect data from patients with gastro-oesophageal adenocarcinomas and CNS involvement both retrospectively and prospectively. Inclusion in the study required a predefined clinical data set, a central neuro-radiological or histopathological confirmation of metastatic CNS involvement and central assessment of HER2 by immunohistochemistry (IHC) and in situ hybridisation (ISH). In addition, expression of E-cadherin and DNA mismatch repair (MMR) proteins were assessed by IHC. Results: One hundred patients fulfilled the inclusion criteria. The population's median age was 59 years (interquartile range: 54-68), of which 85 (85%) were male. Twenty-five patients were of Asian and 75 of Caucasian origin. HER2 status was positive in 36% (95% CI: 26.6-46.2) of cases. Median time from initial diagnosis to the development of brain metastases (BMets) or leptomeningeal carcinomatosis (LC) was 9.9 months (95% CI: 8.5-15.0). Median overall survival from diagnosis was 16.9 months (95% CI: 14.0-20.7) and was not related to the HER2 status. E-cadherin loss was observed in 9% of cases and loss of expression in at least one DNA MMR proteins in 6%. Conclusions: The proportion of a positive HER2 status in patients with gastro-oesophageal adenocarcinoma and CNS involvement was higher than expected. The impact of anti-HER2 therapies should be studied prospectively

    Lymphoma incidence, survival and prevalence 2004–2014 : sub-type analyses from the UK’s Haematological Malignancy Research Network

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    Background: Population-based information about cancer occurrence and survival are required to inform clinical practice and research; but for most lymphomas data are lacking. Methods: Set within a socio-demographically representative UK population of nearly 4 million, lymphoma data (N ¼ 5796) are from an established patient cohort. Results: Incidence, survival (overall and relative) and prevalence estimates for 420 subtypes are presented. With few exceptions, males tended to be diagnosed at younger ages and have significantly (Po0.05) higher incidence rates. Differences were greatest at younger ages: the o15 year male/female rate ratio for all subtypes combined being 2.2 (95% CI 1.3–3.4). These gender differences impacted on prevalence; most subtype estimates being significantly (Po0.05) higher in males than females. Outcome varied widely by subtype; survival of patients with nodular lymphocyte predominant Hodgkin lymphoma approached that of the general population, whereas less than a third of those with other B-cell (e.g., mantle cell) or T-cell (e.g., peripheral-T) lymphomas survived for Z5 years. No males/female survival differences were detected. Conclusions: Major strengths of our study include completeness of ascertainment, world-class diagnostics and generalisability. The marked variations demonstrated confirm the requirement for ‘real-world’ data to inform aetiological hypotheses, health-care planning and the future monitoring of therapeutic changes

    The management of acute venous thromboembolism in clinical practice. Results from the European PREFER in VTE Registry

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    Venous thromboembolism (VTE) is a significant cause of morbidity and mortality in Europe. Data from real-world registries are necessary, as clinical trials do not represent the full spectrum of VTE patients seen in clinical practice. We aimed to document the epidemiology, management and outcomes of VTE using data from a large, observational database. PREFER in VTE was an international, non-interventional disease registry conducted between January 2013 and July 2015 in primary and secondary care across seven European countries. Consecutive patients with acute VTE were documented and followed up over 12 months. PREFER in VTE included 3,455 patients with a mean age of 60.8 ± 17.0 years. Overall, 53.0 % were male. The majority of patients were assessed in the hospital setting as inpatients or outpatients (78.5 %). The diagnosis was deep-vein thrombosis (DVT) in 59.5 % and pulmonary embolism (PE) in 40.5 %. The most common comorbidities were the various types of cardiovascular disease (excluding hypertension; 45.5 %), hypertension (42.3 %) and dyslipidaemia (21.1 %). Following the index VTE, a large proportion of patients received initial therapy with heparin (73.2 %), almost half received a vitamin K antagonist (48.7 %) and nearly a quarter received a DOAC (24.5 %). Almost a quarter of all presentations were for recurrent VTE, with >80 % of previous episodes having occurred more than 12 months prior to baseline. In conclusion, PREFER in VTE has provided contemporary insights into VTE patients and their real-world management, including their baseline characteristics, risk factors, disease history, symptoms and signs, initial therapy and outcomes

    Ariel: Enabling planetary science across light-years

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    A comprehensive overview of radioguided surgery using gamma detection probe technology

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    The concept of radioguided surgery, which was first developed some 60 years ago, involves the use of a radiation detection probe system for the intraoperative detection of radionuclides. The use of gamma detection probe technology in radioguided surgery has tremendously expanded and has evolved into what is now considered an established discipline within the practice of surgery, revolutionizing the surgical management of many malignancies, including breast cancer, melanoma, and colorectal cancer, as well as the surgical management of parathyroid disease. The impact of radioguided surgery on the surgical management of cancer patients includes providing vital and real-time information to the surgeon regarding the location and extent of disease, as well as regarding the assessment of surgical resection margins. Additionally, it has allowed the surgeon to minimize the surgical invasiveness of many diagnostic and therapeutic procedures, while still maintaining maximum benefit to the cancer patient. In the current review, we have attempted to comprehensively evaluate the history, technical aspects, and clinical applications of radioguided surgery using gamma detection probe technology
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