301 research outputs found

    From Nanoethics to the Normativity of Technological Visions

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    Although the variety of different ethical concerns regarding nanotechnologies has been recognized, there is a diffused dissatisfaction in the debate. Nanoethics has been often reduced to a mere check list of concerns or to a sophisticated form of risk and benefit analysis. The debate is not innovative anymore and suffers from repetition. Although the traditional tools of bioethical analysis can be useful for dealing with nanotechnological applications which are already existent or in the pipeline, for a deep engagement with future possible applications the ethical analysis should go beyond the idea of applying abstract ethical principles. Aims of this paper is to propose an alternative way for the normative reflection on those (nano)technological applications which are still at the level of visions. It will be argued that a reflection of the challenges of the future for the current (present) discourse on technological developments is a new and promising field of reflection. Longer detached from an engagement solely with the consequences of technological development, the new analysis will be more comprehensive and lie at the interface between epistemology, ethics and politics

    Contesting Animal Experiments through Ethics and Epistemology: In Defense of a Political Critique of Animal Experimentation

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    Generally, an animal experiment can be defined as an intervention on an animal, which causes suffering, harm, and distress, for scientific purposes. In this definition, animal experiments differ from more general scientific investigations concerning animals, such as observational studies in the wild in the fields of ethology or conservation, in which animals are involved but may not be harmed. Nowadays, the use of the term vivisection, in the case of animal experiments, is very controversial. This term originally referred to the cutting of living bodies for scientific purposes and has a long conceptual history (Maehle, 1992). In ancient times, it was used for referring to experiments on animals as well as on humans. Only in modern times, it became a colloquial term for all animal experiments and was much used by opponents in the nineteenth century, as the criticism of animal experiments became organized in a political movement (Maehle, 1990). Many opponents to animal experiments, nowadays, use the term deliberately in a political sense, connecting to past animal protection movements (e.g., the international Citizens’ Initiative Stop Vivisection, cf. Rippe, 2009). Animal experimenters, on the other hand, oppose the term on the grounds that there is no chirurgical exploration of living animals in experiments (e.g., German Research Foundation, dfg, 2016)

    A slug capturing method in unconventional scenarios: The 5ESCARGOTS code applied to non-Newtonian fluids, high viscous oils and complex geometries

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    Abstract Previous work showed that a one-dimensional, hyperbolic, transient five-equation two-fluid model can predict automatically the formation, growth, and subsequent development of slugs in horizontal and near-horizontal flow. This method was implemented in a finite volume numerical scheme – called 5ESCARGOTS code. Comparison with experimental data showed that it can be used to predict the flow pattern and statistical characteristics (slug velocity, length, and frequency). However, the capabilities of this approach have been tested only for water-air flows in a straight horizontal pipe. In this work, we validate the application of the code to some unconventional problems. Firstly, we test the possibility of slug capturing approach to describe and predict the relevant features of air/high viscosity oils or air/non-Newtonian fluids flows. Comparisons between some slug characteristics and empirical correlations, available in literature, are discussed. Then, we move from simple geometries toward more complex conditions that may be representative of actual application cases, also employing high viscous oils as liquid phase. Comparison against experimental data shows results in reasonable agreement

    Ethik des Essens: In-vitro-Fleisch und „verbesserte Tiere“

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    Velocity profiles description and shape factors inclusion in a hyperbolic, one-dimensional, transient two-fluid model for stratified and slug flow simulations in pipes

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    In a previous work it has been shown that a one-dimensional, hyperbolic, transient five equations two-fluid model is able to numerically describe stratified, wavy, and slug flow in horizontal and near-horizontal pipes. Slug statistical characteristics can be numerically predicted with results in good agreement with experimental data and well-known empirical relations. In this model some approximated and simplified assumptions are adopted to describe shear stresses at wall and at phase interface.In this paper, we focus on the possibility to account for the cross sectional flow by inserting shape factors into the momentum balance equations of the aforementioned model. Velocity profiles are obtained by a pre-integrated model and they are computed at each time step and at each computational cell. Once that the velocity profiles are known, the obtained shape factors are inserted in the numerical resolution. In this way it is possible to recover part of the information lost due to the one-dimensional flow description.Velocity profiles computed in stratified conditions are compared against experimental profiles measured by PIV technique; a method to compute the velocity profile during slug initiation and growth has been developed and the computed velocity distribution in the liquid phase was compared against the one-seventh power law. Keywords: Multi-phase pipeline transport, Oil & gas, Hyperbolic two-fluid model, Velocity profiles, Shape factor

    Clinical outcomes under hydroxyurea treatment in polycythemia vera: a systematic review and meta-analysis

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    H ydroxyurea is the standard treatment in high-risk patients with polycythemia vera. However, estimates of its effect in terms of clinical outcomes (thrombosis, bleeding, hematologic transformations and mortality) are lacking. We performed a meta-analysis to determine the absolute risk of events in recent cases of patients under hydroxyurea treatment. We searched for relevant articles or abstracts in the following databases: Medline, EMBASE, clinicaltrials.gov, WHO International Clinical Trials Registry, LILACS. Sixteen studies published from 2008 to 2018 reporting number of events using World Health Organization diagnosis for polycythemia vera were selected. Through a random effect logistic model, incidences, study heterogeneity and confounder effects were estimated for each outcome at different follow ups. Overall, 3,236 patients were analyzed. While incidences of thrombosis and acute myeloid leukemia were stable over time, mortality and myelofibrosis varied depending on followup duration. Thrombosis rates were 1.9%, 3.6% and 6.8% persons/year at median ages 60, 70 and 80 years, respectively. Higher incidence of arterial events was predicted by previous cardiovascular complication. Leukemic transformation incidence was 0.4% persons/year. Incidence of transformation to myelofibrosis and mortality were significantly dependent on age and follow-up duration. For myelofibrosis, rates were 5.0 at five years and 33.7% at ten years; overall mortality was 12.6% and 56.2% at five and ten years, respectively. In conclusion, we provide reliable risk estimates for the main outcomes in polycythemia vera patients under hydroxyurea treatment. These findings can help design comparative clinical trials with new cytoreductive drugs and prove the feasibility of using critical end points for efficacy, such as major thrombosis

    a computer assisted robotic platform for vascular procedures exploiting 3d us based tracking

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    AbstractBackground: Cardiovascular diseases are the first cause of death globally: an estimated 17.5 million people died in 2012. By combining the benefits of magnetic navigation and ultrasound (US) imaging, the authors proposed a robotic platform (i.e. the MicroVAST platform) for intravascular medical procedures.Methods: A 3D imaging US-based tracking algorithm is implemented for the navigation of a magnetic-dragged soft-tethered device. Tests were performed to evaluate the algorithm in terms of tracking error and precision of locomotion.Results: The 3D imaging US-based algorithm tracked the endovascular device with an error of 6.4 ± 2.8 pixels and a mean displacement between the endovascular device and the preoperative path of 13.6 ± 4.5 mm (computational time of 12.2 ± 1.5 ms and 30.7 ± 6.1 matched features).Conclusions: The MicroVAST platform includes innovative solutions for navigation allowing for an assisted magnetic locomotion of medical devices in the cardiovascular district by combining a 3D ima..
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