10,136 research outputs found

    Adjuvant and post-surgical treatment in high-grade epithelial ovarian cancer

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    Cytoreductive surgery is the mainstay of treatment for high-grade epithelial ovarian cancer. Although for early stage disease outcomes following surgery alone are good, the risk of recurrence necessitates adjuvant chemotherapy for the majority of patients. Post-operative chemotherapy in advanced-stage disease, or neoadjuvant chemotherapy followed by surgery has improved progression-free survival (PFS) and overall survival (OS). However, despite the use of chemotherapy, the rate of recurrence remains high. In recent years, there has been considerable increase in knowledge regarding the biology of ovarian cancer, which has led to a journey of drug discovery, facilitating the use of novel targeted agents such as VEGF inhibitors and, more recently, PARP inhibitors in the first-line treatment of ovarian cancer. Here, we outline the current evidence-based guidance for systemic therapies in ovarian cancer and highlight the ongoing research to improve patient outcome

    The effect of recent fire history on the abundance and viability of large seeds in the soil of sclerophyll forest in Tasmania, Australia

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    There are few data on the effects of recent fire history on the composition of soil seed banks in sclerophyll forest communities. We predicted that the abundance and viability of soil-stored seeds would vary with fire history. Soils were sampled from areas with six different fire histories on Mt Nelson, Tasmania, Australia. Large seeds were extracted by hand separation and tested for viability. Responses to at least one of the two strongly-correlated components of fire history were detected in several taxa and for native and exotic seed. Native seeds, exotic seeds, Astroloma humifusum seed and Exocarpos cupressiformis seed were all more abundant in the soils of areas with one or less fires in the last 60 years than in the soils of areas burnt five times over the last 60 years. The viability of A. humifusum seeds decreased with fire frequency. These results support the hypothesis that frequent and recent fire can deplete the soil seed bank, and reduce soil seed viability, at least for some large-seeded species and species groups

    High‑temperature structural phase transitions in neighborite: a high‑resolution neutron powder diffraction investigation

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    The nature of the apparently continuous structural phase transition at 1,049 K in the perovskite-structured, MgSiO3 isomorph, neighborite (NaMgF3), from the orthorhombic (Pbnm) hettotype phase to the cubic ( Pm3¯m ) aristotype structure, has been re-investigated using high-resolution, time-of-flight neutron powder diffraction. Using data collected at 1 K intervals close to the nominal phase transition temperature, the temperature dependence of the intensities of superlattice reflections at the M point (2πa[12,12,0]) and the R point (2πa[12,12,12]) of the pseudocubic Brillouin zone indicate the existence of a new intermediate tetragonal phase in space group P4/mbm, with a narrow phase field extending from ~1,046.5 to ~1,048.5 K, at ambient pressure. Group theoretical analysis shows that the structural transitions identified in this study, Pbnm–P4/mbm, and P4/mbm– Pm3¯m , are permitted to be second order. The observation of the tetragonal phase resolves the longstanding issue of why the high-temperature phase transition, previously identified as Pbnm– Pm3¯m , and which would be expected to be first order under Landau theory, is in fact found to be continuous. Analysis of the pseudocubic shear strain shows it to vary with a critical exponent of 0.5 implying that the phase transition from Pbnm to P4/mbm is tricritical in character. The large librational modes that exist in the MgF6 octahedron at high temperature, and the use of Gaussian probability density functions to describe atomic displacements, result in apparent bond shortening in the Mg–F distances, making mode amplitude determination an unreliable method for determination of the critical exponent from internal coordinates. Crystal structures are reported for the three phases of NaMgF3 at 1,033 K (Pbnm), 1,047 K (P4/mbm) and 1,049 K ( Pm3¯m )

    Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management

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    Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor) to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i) food quantity, (ii) food quality, and (iii) the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems

    Sail optimization for upwind sailing: application in a Tornado, the Olympic class catamaran.

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    A study of a boat’s motion is carried out in order to analyze the aerodynamic properties of the optimal sail for obtaining the maximum velocity when sailing to windward. The mechanics study shows the optimal CL and CD for a given sail and how the shape of the aerodynamic polar of the sail should be. A parametrical analysis of the aerodynamics of a sail is then carried out varying the maximum camber, position of the maximum camber in the chord direction and position of the maximum camber in the mast direction. The parametric analysis is done numerically with a vortex lattice method (VLM) and experimentally in a wind tunnel. The results show that the influence of the relevant parameters studied can be reduced to the variation of two parameters, A and B, defining the polar of the sail, CD = B + A2CL 2; and the influence of parameters A and B on the maximum VMG obtainable are calculated

    The acute inflammatory response to intranigral α-synuclein differs significantly from intranigral lipopolysaccharide and is exacerbated by peripheral inflammation

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    <p>Abstract</p> <p>Background</p> <p>Activated microglia are a feature of the host response to neurodegeneration in Parkinson's disease (PD) and are thought to contribute to disease progression. Recent evidence suggests that extracellular α-synuclein (eSNCA) may play an important role in the pathogenesis of PD and that this may be mediated by a microglial response.</p> <p>Methods</p> <p>We wished to discover whether the host response to eSNCA would be sufficient to induce significant cytokine production. <it>In vitro </it>cultured BV-2 microglia were used to determine the basic inflammatory response to eSNCA. <it>In vivo</it>, 8-week old Biozzi mice were subjected to a single intranigral injection of either 3 μg SNCA, lipopolysaccharide (LPS) or serum protein (BSA) and allowed to recover for 24 hours. A second cohort of animals were peripherally challenged with LPS (0.5 mg/kg) 6 hours prior to tissue collection. Inflammation was studied by quantitative real-time PCR for a number of pro-inflammatory genes and immunohistochemistry for microglial activation, endothelial activation and cell death.</p> <p>Results</p> <p><it>In vitro </it>data showed a robust microglial response to SNCA, including a positive NFĸB response and the production of pro-inflammatory cytokines. Direct injection of SNCA into the substantia nigra resulted in the upregulation of mRNA expression of proinflammatory cytokines, the expression of endothelial markers of inflammation and microglial activation. However, these results were significantly different to those obtained after direct injection of LPS. By contrast, when the animals were injected intracerebrally with SNCA and subsequently challenged with systemic LPS, the level of production of IL-1β in the substantia nigra became comparable to that induced by the direct injection of LPS into the brain. The injection of albumin into the nigra with a peripheral LPS challenge did not provoke the production of a significant inflammatory response. Direct injection of LPS into the substantia nigra also induces cell death in a more robust manner than direct injection of either SNCA or BSA.</p> <p>Conclusion</p> <p>These results suggest that the presence of eSNCA protein 'primes' microglia, making them susceptible to environmental proinflammatory challenge. For this reason, we hypothesise that where 'inflammation' contributes to the disease progression in PD, it does so in a punctuate manner (on-off) as a result of systemic events.</p

    The impact of surgery for vulval cancer upon health-related quality of life and pelvic floor outcomes during the first year of treatment: A longitudinal, mixed methods study

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    © 2015 The Authors.Objective: To measure the long-term impact of surgical treatment for vulval cancer upon health-related quality of life and pelvic floor outcomes during the first year of therapy. Methods: Prospective, longitudinal, mixed-methods study. Twenty-three women aged >18 years with a new diagnosis of vulval cancer were recruited. The EORTC QLQ C30, SF-36 and an electronic pelvic floor assessment questionnaire (ePAQ-PF) were administered at baseline (pre-treatment) and 3, 6, 9 and 12 months post-treatment. Mixed effects repeated measures models (all adjusted for age and BMI) were used to investigate changes over time and differences between cancer stage. Qualitative interviews were carried out with 11 of the women and analysed using a thematic approach. Results: Mean age was 59.9 years (SD=15.3; range=23.8-86.6 yrs). Mean BMI was 30.0 (SD=4.5; range=24.4-38.2). Sixteen women had early (Stage 1 to 2B), and seven women had advanced stage disease (Stage 3 to 4B). Questionnaire scores revealed that physical and social functioning, fatigue, pain and general sex life were significantly worse at 12 months than pre-treatment (p=< 0.05). Qualitative analysis revealed multiple treatment side effects which were perceived as severe and enduring. Women with advanced vulval cancer had significantly worse SF-36 mental health scores at 12 months compared to women with early stage disease (p=0.037). Conclusions: Surgery for vulval cancer has long-term implications which can be persistent 12 months post-treatment. High rates of morbidity relating to lymphoedema and sexual function re-enforce the need for specialist clinics to support women who suffer these complications
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