114 research outputs found

    An atomic force microscope operating at hypergravity for in situ measurement of cellular mechano-response

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    We present a novel atomic force microscope (AFM) system, operational in liquid at variable gravity, dedicated to image cell shape changes of cells in vitro under hypergravity conditions. The hypergravity AFM is realized by mounting a stand-alone AFM into a large-diameter centrifuge. The balance between mechanical forces, both intra- and extracellular, determines both cell shape and integrity. Gravity seems to be an insignificant force at the level of a single cell, in contrast to the effect of gravity on a complete (multicellular) organism, where for instance bones and muscles are highly unloaded under near weightless (microgravity) conditions. However, past space flights and ground based cell biological studies, under both hypogravity and hypergravity conditions have shown changes in cell behaviour (signal transduction), cell architecture (cytoskeleton) and proliferation. Thus the role of direct or indirect gravity effects at the level of cells has remained unclear. Here we aim to address the role of gravity on cell shape. We concentrate on the validation of the novel AFM for use under hypergravity conditions. We find indications that a single cell exposed to 2 to 3 × g reduces some 30–50% in average height, as monitored with AFM. Indeed, in situ measurements of the effects of changing gravitational load on cell shape are well feasible by means of AFM in liquid. The combination provides a promising technique to measure, online, the temporal characteristics of the cellular mechano-response during exposure to inertial forces

    Sustainability metrics for coal power generation in Australia

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    The basis of this work was to investigate the relative environmental impacts of various power generators knowing that all plants are located in totally different environments and that different receptors will experience different impacts. Based on IChemE sustainability metrics paradigm, we calculated potential environmental indicators (P-EI) that represent the environmental burden of masses of potential pollutants discharged into different receiving media. However, a P-EI may not be of significance, as it may not be expressed at all in different conditions, so to try and include some receiver significance we developed a methodology to take into account some specific environmental indicators (S-EI) that refer to the environmental attributes of a specific site. In this context, we acquired site specific environmental data related to the airsheds and water catchment areas in different locations for a limited number of environmental indicators such as human health (carcinogenic) effects, atmospheric acidification, photochemical (ozone) smog and eutrophication. The S-EI results from this particular analysis show that atmospheric acidification has highest impact value while health risks due to fly ash emissions are considered not to be as significant. This is due to the fact that many coal power plants in Australia are located in low population density air sheds. The contribution of coal power plants to photochemical (ozone) smog and eutrophication were not significant. In this study, we have considered emission related data trends to reflect technology performance (e.g., P-EI indicators) while a real sustainability metric can be associated only with the specific environmental conditions of the relevant sites (e.g., S-EI indicators)

    Voice outcome after unilateral ELS type III or bilateral type II resections for T1-T2 glottic carcinoma: Results after 1 year

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    Abstract Background: Voice outcome was assessed in patients with extended T1 and limited T2 glottic carcinoma, treated with a unilateral type III or a bilateral type II resection according to the European Laryngological Society (ELS) classification. Methods: Objective evaluation (acoustic and aerodynamic parameters), perceptual evaluation (GRBAS), and patients' self-assessment (voice handicap index [VHI]) were performed before and 1 year after treatment. Results were evaluated according to ELS resection type and the involvement of the anterior commissure. Results: The majority of voice parameters in all resection subgroups showed an improvement of the mean score 1 year postoperatively. Grade of dysphonia varied between 1.15 and 1.66 postoperatively and VHI score varied from 23.3 to 24.5. Conclusion: Voice outcome after ELS unilateral type III or a bilateral type II resection for extended T1 and limited T2 glottic carcinoma is good with mild to very moderate perceptive dysphonia and low self-reported voice impairment

    Influence of Conversion and Anastomotic Leakage on Survival in Rectal Cancer Surgery; Retrospective Cross-sectional Study

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    Towards a definition of safety for individual drivers lane behavior

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    To assess lateral control performance in drivers, lane behaviour indicators such as the mean lane position, standard deviation of lane position and time-to-line-crossing are the most frequently used measures. For lane position, the commonly accepted (qualitative) proposition is that increased lane swerving indicates reduced vehicle control and hence a decreased level of safety. For time-to-line-crossing, a rule of thumb is that a value of less than 1s implies a decreased level of safety (e.g. an increased risk of lane exceedance). However, a quantitative relationship with safety similar to the one between speed and safety or between speed variability and safety does not yet exist for lane behaviour indicators. In the current study, we intend to establish a link between this type of driving behaviour in individual drivers and the level of safety, using data from both studies related to impaired driving and studies not related to impaired driving. The results from this study can be a first step in ultimately setting cut-off values for safe driving based on individual behavioural indicators
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