112 research outputs found

    Force transmission in a packing of pentagonal particles

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    We perform a detailed analysis of the contact force network in a dense confined packing of pentagonal particles simulated by means of the contact dynamics method. The effect of particle shape is evidenced by comparing the data from pentagon packing and from a packing with identical characteristics except for the circular shape of the particles. A counterintuitive finding of this work is that, under steady shearing, the pentagon packing develops a lower structural anisotropy than the disk packing. We show that this weakness is compensated by a higher force anisotropy, leading to enhanced shear strength of the pentagon packing. We revisit "strong" and "weak" force networks in the pentagon packing, but our simulation data provide also evidence for a large class of "very weak" forces carried mainly by vertex-to-edge contacts. The strong force chains are mostly composed of edge-to-edge contacts with a marked zig-zag aspect and a decreasing exponential probability distribution as in a disk packing

    Recommandations pour l’utilisation de la toxine botulinique de type A (Botox®) dans l’hyperactivité vésicale réfractaire idiopathique

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    RésuméObjectifsDéfinir des recommandations pour l’utilisation pratique de la toxine botulinique de type A (BoNTA) dans l’hyperactivité vésicale réfractaire idiopathique (HAVRI).MéthodeÉlaboration de recommandations de bonne pratique par consensus formalisé, validées par un groupe de 13 experts puis par un groupe de lecture indépendant.RésultatsEn cas d’infection urinaire celle-ci doit être traitée et l’injection reportée. Avant l’injection, il est recommandé de s’assurer de la faisabilité et de l’acceptabilité de l’auto-sondage. L’injection peut être réalisée après une anesthésie locale urétro-vésicale (lidocaïne), éventuellement complétée par l’inhalation de protoxyde d’azote et parfois sous anesthésie générale. L’injection sera réalisée au bloc opératoire ou en salle d’endoscopie. La vessie ne doit pas être trop remplie (risque de perforation). Le traitement doit être appliqué en 10 à 20 injections de 0,5 à 1mL réparties de manière homogène dans la vessie en restant à distance des méats urétéraux. Il n’est pas recommandé de laisser en place une sonde vésicale sauf en cas d’hématurie importante. Le patient doit être surveillé jusqu’à la reprise mictionnelle. Une note d’information sur les effets indésirables éventuels doit lui être remise à sa sortie. Une consultation doit être prévue 3 mois après la première injection (calendrier mictionnel, débitmétrie, résidu post-mictionnel et examen cytobactériologique des urines). Un résidu >200mL et/ou symptomatique doit faire discuter des auto-sondages. Une nouvelle injection pourra être envisagée lorsque le bénéfice clinique de la précédente s’estompe (entre 6 et 9 mois).ConclusionsLe respect de ces recommandations devrait permettre une utilisation optimale de la BoNTA.Niveau de preuve3.SummaryObjectivesProvide guidelines for practical usage of botulinum toxin type A (BoNTA) for refractory idiopathic Overactive Bladder management.Patients and methodsGuidelines using formalized consensus guidelines method. These guidelines have been validated by a group of 13 experts quoting proposals, subsequently reviewed by an independent group of experts.ResultsIn the case of patients with urinary tract infection, it must be treated and injection postponed. Before proposing an injection, it is recommended to ensure the feasibility and acceptability of self-catheterisation by patient. The injection can be performed after local anesthesia of the bladder and urethra (lidocaine), supplemented where necessary by nitrous oxide inhalation and sometimes under general anesthesia. Injection is performed in the operating room or endoscopy suite. The bladder should not be too filled (increased risk of perforation). Treatment should be applied in 10 to 20 injections of 0.5 to 1mL homogeneously distributed in the bladder at a distance from the urethral orifices. It is not recommended to leave a urinary catheter in place except in cases of severe hematuria. The patient should be monitored until resumption of micturition. After the first injection, an appointment must be scheduled within 3 months (micturition diary, uroflowmetry, measurement of residual urine and urine culture). Performance of self-catheterisation should be questioned in the case of a symptomatic post-void residual and/or a residue>200mL. A new injection may be considered when the clinical benefit of the previous injection diminishes (between 6 and 9 months). A period of three months must elapse between each injection.ConclusionsImplementation of these guidelines may promote best practice usage of BoNTA with optimal risk/benefit ratio

    Marxism Lost and Found: Alasdair MacIntyre and the Contemporary Debate

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    This paper examines the changing nature of debates that focus on the philosophy of Alasdair MacIntyre. Whilst outlining the history of MacIntyre’s engagement with Marxism and some of his key ideas, it argues that it is only recently that such debates have begun to rightfully recognise the continued relevance of Marxism to such discussions. I note that crucial aspects of MacIntyre’s politics and philosophy, particularly his opposition to capitalism, are now integral to the contemporary debate which helps in generating a shared vision of radical politics. Nevertheless, I point out that key disagreements still remain as to the role of Marxism within such debates, the validity of MacIntyre’s critique of Marxism, as well as the potentially problematic post-Marxist practice that MacIntyre advocates in After Virtue and beyond

    Institutionalising Kant's political philosophy: Foregrounding cosmopolitan right

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    There exists a longstanding debate over the global institutional implications of Immanuel Kant's political philosophy: does such a philosophy entail a federal world government, or instead only a confederal ‘league of nations’? However, while the systematic nature of Kant's tripartite ‘doctrine of right' is well recognised, this debate has been conducted with all but exclusive focus on ‘international right' in particular. This article, by contrast, brings ‘cosmopolitan right' firmly into view. It proceeds by way of engagement with the two Kantian arguments made in defence of a ‘league of nations’ in discussion of international right, each of which appeals to aspects of states’ supposed ‘personhood’: the first appeals to states’ distinctive moral personality; the second to states’ physical manifestation. The article considers what happens when we assess these arguments not just in light of the demands of international right, but also in light of cosmopolitan right, and thus in light of public right more comprehensively. The answer is that such arguments cannot succeed as full defences of a league of nations. Indeed, when we assess such arguments with cosmopolitan right in view, they point instead – either tentatively or definitively – in the direction of world government

    Radical prostatectomy after vascular-targeted photodynamic therapy (VTP) with TOOKAD® : feasibility, early and intermediate results

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    Purpose: Vascular targeted photodynamic therapy with TOOKAD® is a new therapeutic option for localized prostate cancer management. The objectives of this study were to assess the feasibility of radical prostatectomy after vascular targeted photodynamic therapy and describe functional and oncologic outcomes. Materials and Methods: We retrospectively included in study 45 patients who underwent salvage radical prostatectomy after vascular targeted photodynamic therapy for recurrent prostate cancer at a total of 14 surgical centers in Europe between October 2008 and March 2017. Of the 42 radical prostatectomies performed 16 were robot-assisted, 6 were laparoscopic and 20 were open surgery. Primary end points were morbidity and technical difficulties. Secondary end points were early and intermediate postoperative functional and oncologic outcomes. Results: Median operative time was 180 minutes (IQR 150-223). Median blood loss was 200 ml (IQR 155-363). According to the surgeons the surgery was easy in 29 patients (69%) and difficult in 13 (31%). Nerve sparing was feasible in 14 patients (33%). Five postoperative complications (12%) were found, including 2 Clavien I, 2 Clavien II and 1 Clavien IIIB complications. Of the cases 13 (31%) were pT3 and 21 (50%) were pT2c. Surgical margins were positive in 13 patients (31%). Prostate specific antigen was undetectable at 6 to 12 months in 37 patients (88%). Nine patients underwent complementary radiotherapy. Four patients had final prostate specific antigen greater than 0.2 ng/ml at a median followup of 23 months (IQR 12-36). At 1 year 27 patients (64%) were completely continent (no pads) and 10 (24%) had low incontinence (1 pad). Four patients (11%) recovered potency without treatment and 23 (64%) recovered potency with appropriate treatment. Conclusions: Salvage radical prostatectomy after vascular targeted photodynamic therapy treatment was feasible and safe without difficulty for most of the surgeons

    Oligomerization of Monoolefins by Homogeneous Catalysts

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    In this article are summarized the different mechanistic pathways for the oligomerization of monoolefins by homogeneous catalysts, particularly for ethylene and alpha olefins. The major topics are: the production of non regioselective and also regioselective olefin dimers, the production of linear alpha olefins by ethylene oligomerization as well as the selective dimerization of ethylene and its selective trimerization. Several industrial developments initiated by IFP are presented to illustrate this topic
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