1,354 research outputs found

    Characterisation of a phantom for multiwavelength quantitative photoacoustic imaging

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    Quantitative photoacoustic imaging (qPAI) has the potential to provide high- resolution in vivo images of chromophore concentration, which may be indicative of tissue function and pathology. Many strategies have been proposed recently for extracting quantitative information, but many have not been experimentally verified. Experimental phantom-based validation studies can be used to test the robustness and accuracy of such algorithms in order to ensure reliable in vivo application is possible. The phantoms used in such studies must have well-characterised optical and acoustic properties similar to tissue, and be versatile and stable. Polyvinyl chloride plastisol (PVCP) has been suggested as a phantom for quality control and system evaluation. By characterising its multiwavelength optical properties, broadband acoustic properties and thermoelastic behaviour, this paper examines its potential as a phantom for qPAI studies too. PVCP's acoustic properties were assessed for various formulations, as well as its intrinsic optical absorption, and scattering with added TiO2, over a range of wavelengths from 400-2000 nm. To change the absorption coefficient, pigment-based chromophores that are stable during the phantom fabrication process, were used. These yielded unique spectra analogous to tissue chromophores and linear with concentration. At the high peak powers typically used in photoacoustic imaging, nonlinear optical absorption was observed. The Grüneisen parameter was measured to be Γ\Gamma   =  1.01  ±  0.05, larger than typically found in tissue, though useful for increased PA signal. Single and multiwavelength 3D PA imaging of various fabricated PVCP phantoms were demonstrated

    Mapping and assessment of ecosystems and their services. Urban ecosystems

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    Action 5 of the EU Biodiversity Strategy to 2020 requires member states to Map and Assess the state of Ecosystems and their Services (MAES). This report provides guidance for mapping and assessment of urban ecosystems. The MAES urban pilot is a collaboration between the European Commission, the European Environment Agency, volunteering Member States and cities, and stakeholders. Its ultimate goal is to deliver a knowledge base for policy and management of urban ecosystems by analysing urban green infrastructure, condition of urban ecosystems and ecosystem services. This report presents guidance for mapping urban ecosystems and includes an indicator framework to assess the condition of urban ecosystems and urban ecosystem services. The scientific framework of mapping and assessment is designed to support in particular urban planning policy and policy on green infrastructure at urban, metropolitan and regional scales. The results are based on the following different sources of information: a literature survey of 54 scientific articles, an online-survey (on urban ecosystems, related policies and planning instruments and with participation of 42 cities), ten case studies (Portugal: Cascais, Oeiras, Lisbon; Italy: Padua, Trento, Rome; The Netherlands: Utrecht; Poland: Poznań; Spain: Barcelona; Norway: Oslo), and a two-day expert workshop. The case studies constituted the core of the MAES urban pilot. They provided real examples and applications of how mapping and assessment can be organized to support policy; on top, they provided the necessary expertise to select a set of final indicators for condition and ecosystem services. Urban ecosystems or cities are defined here as socio-ecological systems which are composed of green infrastructure and built infrastructure. Urban green infrastructure (GI) is understood in this report as the multi-functional network of urban green spaces situated within the boundary of the urban ecosystem. Urban green spaces are the structural components of urban GI. This study has shown that there is a large scope for urban ecosystem assessments. Firstly, urban policies increasingly use urban green infrastructure and nature-based solutions in their planning process. Secondly, an increasing amount of data at multiple spatial scales is becoming available to support these policies, to provide a baseline, and to compare or benchmark cities with respect to the extent and management of the urban ecosystem. Concrete examples are given on how to delineate urban ecosystems, how to choose an appropriate spatial scale, and how to map urban ecosystems based on a combination of national or European datasets (including Urban Atlas) and locally collected information (e.g., location of trees). Also examples of typologies for urban green spaces are presented. This report presents an indicator framework which is composed of indicators to assess for urban ecosystem condition and for urban ecosystem services. These are the result of a rigorous selection process and ensure consistent mapping and assessment across Europe. The MAES urban pilot will continue with work on the interface between research and policy. The framework presented in this report needs to be tested and validated across Europe, e.g. on its applicability at city scale, on how far the methodology for measuring ecosystem condition and ecosystem service delivery in urban areas can be used to assess urban green infrastructure and nature-based solutions

    Rituximab versus tocilizumab and B-cell status in TNF-alpha inadequate-responder rheumatoid arthritis patients: the R4-RA RCT

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    BackgroundAlthough biological therapies have transformed the outlook for those with rheumatoid arthritis, there is a lack of any meaningful response in approximately 40% of patients. The role of B cells in rheumatoid arthritis pathogenesis is well recognised and is supported by the clinical efficacy of the B-cell-depleting agent rituximab (MabThera, F. Hoffman La-Roche Ltd, Basel, Switzerland). Rituximab is licensed for use in rheumatoid arthritis following failure of conventional synthetic disease-modifying antirheumatic drugs and tumour necrosis factor inhibitor therapy. However, over 50% of patients show low/absent synovial B-cell infiltration, suggesting that, in these patients, inflammation is driven by alternative cell types. This prompted us to test the hypothesis that, in synovial biopsy B-cell-poor patients, tocilizumab (RoActemra, F. Hoffman La-Roche Ltd, Basel, Switzerland) (targeting interleukin 6) is superior to rituximab (targeting CD20+/B cells).DesignThe R4–RA (A Randomised, open-labelled study in anti-TNFalpha inadequate responders to investigate the mechanisms for Response, Resistance to Rituximab versus Tocilizumab in Rheumatoid Arthritis patients) trial is a 48-week Phase IV, open-label, randomised controlled trial conducted in 19 European centres that recruited patients failing on or intolerant to conventional synthetic disease-modifying antirheumatic drug therapy and at least one tumour necrosis factor inhibitor.ParticipantsSynovial tissue was obtained at trial entry and classified histologically as B-cell rich or B-cell poor to inform balanced stratification. Patients were randomised on a 1 : 1 basis to receive standard therapy with rituximab or tocilizumab. B-cell-poor/-rich molecular classification was also carried out. The study was powered to test the superiority of tocilizumab over rituximab at 16 weeks in the B-cell-poor population.Main outcome measuresThe primary end point was defined as an improvement in the Clinical Disease Activity Index (CDAI) score of ≥ 50% from baseline. In addition, patients were considered to be non-responders if they did not reach an improvement in CDAI score of ≥ 50% and a CDAI score of ResultsIn total, 164 patients were randomised: 83 patients received rituximab and 81 received tocilizumab. Eighty-one out of 83 rituximab patients and 73 out of 81 tocilizumab patients completed treatment up to week 16 (primary end point). Baseline characteristics were comparable between the treatment groups. In the histologically classified B-cell-poor population (n = 79), no significant difference was observed in the primary outcome, an improvement in CDAI score of ≥ 50% from baseline (risk ratio 1.25, 95% confidence interval 0.80 to 1.96). A supplementary analysis of the CDAI-MTR, however, did reach statistical significance (risk ratio 1.96, 95% confidence interval 1.01 to 3.78). In addition, when B-cell-poor classification was determined molecularly, both the primary end point and the CDAI-MTR were statistically significant (risk ratio 1.72, 95% confidence interval 1.02 to 2.91, and risk ratio 4.12, 95% confidence interval 1.55 to 11.01, respectively). Moreover, a larger number of secondary end points achieved significance when classified molecularly than when classified histologically. In the B-cell-rich population, there was no significant difference between treatments in the majority of both primary and secondary end points. There were more adverse events and serious adverse events, such as infections, in the tocilizumab group than in the rituximab group.ConclusionTo our knowledge, this is the first biopsy-based, multicentre, randomised controlled trial of rheumatoid arthritis. We were unable to demonstrate that tocilizumab was more effective than rituximab in patients with a B-cell-poor pathotype in our primary analysis. However, superiority was shown in most of the supplementary and secondary analyses using a molecular classification. These analyses overcame possible unavoidable weaknesses in our original study plan, in which the histological method of determining B-cell status may have misclassified some participants and our chosen primary outcome was insufficiently sensitive. Given the significant results observed using the molecular classification, future research will focus on refining this stratification method and evaluating its clinical utility.Trial registrationCurrent Controlled Trials ISRCTN97443826.FundingThis project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a Medical Research Council and National Institute for Health and Care Research (NIHR) partnership. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 9, No. 7. See the NIHR Journals Library website for further project information

    Inter-hemispheric EEG coherence analysis in Parkinson's disease : Assessing brain activity during emotion processing

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    Parkinson’s disease (PD) is not only characterized by its prominent motor symptoms but also associated with disturbances in cognitive and emotional functioning. The objective of the present study was to investigate the influence of emotion processing on inter-hemispheric electroencephalography (EEG) coherence in PD. Multimodal emotional stimuli (happiness, sadness, fear, anger, surprise, and disgust) were presented to 20 PD patients and 30 age-, education level-, and gender-matched healthy controls (HC) while EEG was recorded. Inter-hemispheric coherence was computed from seven homologous EEG electrode pairs (AF3–AF4, F7–F8, F3–F4, FC5–FC6, T7–T8, P7–P8, and O1–O2) for delta, theta, alpha, beta, and gamma frequency bands. In addition, subjective ratings were obtained for a representative of emotional stimuli. Interhemispherically, PD patients showed significantly lower coherence in theta, alpha, beta, and gamma frequency bands than HC during emotion processing. No significant changes were found in the delta frequency band coherence. We also found that PD patients were more impaired in recognizing negative emotions (sadness, fear, anger, and disgust) than relatively positive emotions (happiness and surprise). Behaviorally, PD patients did not show impairment in emotion recognition as measured by subjective ratings. These findings suggest that PD patients may have an impairment of inter-hemispheric functional connectivity (i.e., a decline in cortical connectivity) during emotion processing. This study may increase the awareness of EEG emotional response studies in clinical practice to uncover potential neurophysiologic abnormalities

    Vineyard microclimate and yield under different plastic covers.

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    The use of plastic cover in vineyards minimizes effects of adverse weather conditions. The northwest of São Paulo State is one of the largest grape producing regions in Brazil; however, few studies investigate the effects of different plastic covers on vineyards in this region. This study compared the effect of black shading screen (BSS) and braided polypropylene film (BPF) on BRS Morena vineyard microclimate, grown on an overhead trellis system in the northwestern São Paulo. The experiments were carried out during three growing seasons (2012 ? 2014). BSS allowed superior incoming solar radiation (SR) transmissivity, resulting in higher net radiation (Rn), and higher ratio between photosynthetically active (PAR) and SR. No differences were observed between the average air temperatures (T) and relative humidity (RH) of covered environments (BPF and BSS) and outside condition (automatic weather station ? AWS), due to high air circulation, despite wind speed (WS) reduction caused by plastic covers. BPF provided better conditions for vineyard growth with higher fruit yield than vineyard under BSS regarding the number of shoots with bunches per plant, bunch and stem weights, longitudinal diameter of berries, quantity of fertile buds per shoot, and yield per shoot and per plant. BPF covers also influenced leaf size and growth speed of plants in vineyards. Keywords Black shading screen . Braided polypropylene film . BRS Morena . Leaf wetness duration . Yiel
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