567 research outputs found

    Surgical glues: are they really adhesive?

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    Objective: The aim of this study is to create a standard test to approve the efficacy of a surgical sealant. An industrial test, the bulge-and-blister test, which is very convenient for measuring adhesion energy, is applied to the surgical field to quantify adhesion of bioadhesives. Methods: Samples were composed of two circular layers of equine pericardium glued by the surgical sealant studied. The sample was fixed to a support with an industrial glue. The support and the bottom layer were perforated in the centre to allow injection of pressurised water. Water was progressively introduced through the hole in the support and the bottom layer to create a blister with constant radius, increasing height and internal pressure during this first step. At a critical pressure, delamination started, the radius and height of the blister increased and the pressure decreased. At this point, the adhesion energy could be determined. The experimental parameters were measured with a pressure sensor and an optical profilometry device for deflection. Results: Adhesion testing was carried out in eight paired equine pericardium samples bonded with a Dermabond® cyanoacrylate glue. The average value of the practical adhesion energy is 2.3Jm−2 with a standard deviation of 1.5Jm−2. Conclusion: Application of the bulge-and-blister test to the surgical field was achieved and allowed a quantification of adhesion of a surgical glue. Such information is essential to compare the different surgical glues presently available. The study of the impact of bonding conditions such as pressure, hygrometry or setting conditions will provide a better understanding of the characteristics of adhesion in the surgical fiel

    Informed consent for suspension microlaryngoscopy:what should we tell the patient? A consensus statement of the European Laryngological Society

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    Introduction: Informed consent for any surgical intervention is necessary, as only well-informed patients can actively participate in the decision-making process about their care, and better understand the likely or potential outcomes of their treatment. No consensus exists on informed consent for suspension microlaryngoscopy (SML). Materials and methods: Informed consent procedures in nine countries on five continents were studied. Results: Several risks can be discerned: risks of SML as procedure, anesthesiologic risks of SML, specific risks of phonosurgery, risks of inadequate glottic exposure or unexpected findings, risks of not treating. SML has recognized potential complications, that can be divided in temporary (minor) complications, and lasting (major) complications. Conclusion: SML is a safe procedure with low morbidity, and virtually no mortality. Eleven recommendations are provided

    Refractive elastic scattering of carbon and oxygen nuclei: The mean field analysis and Airy structures

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    The experimental data on the 16^{16}O+12+^{12}C and 18^{18}O+12+^{12}C elastic scatterings and their optical model analysis are presented. Detailed and complete elastic angular distributions have been measured at the Strasbourg Vivitron accelerator at several energies covering the energy range between 5 and 10 MeV per nucleon. The elastic scattering angular distributions show the usual diffraction pattern and also, at larger angles, refractive effects in the form of nuclear rainbow and associated Airy structures. The optical model analysis unambiguously shows the evolution of the refractive scattering pattern. The observed structure, namely the Airy minima, can be consistently described by a nucleus-nucleus potential with a deep real part and a weakly absorptive imaginary part. The difference in absorption in the two systems is explained by an increased imaginary (mostly surface) part of the potential in the 18^{18}O+12+^{12}C system. The relation between the obtained potentials and those reported for the symmetrical 16^{16}O+16+^{16}O and 12^{12}C+12+^{12}C systems is drawn.Comment: 10 pages, 9 figures, Phys. rev. C in pres

    Five-Year Outcomes of the SuperB Trial:A Multicenter Randomized Controlled Trial Comparing Heparin-Bonded Endograft to Surgical Femoropopliteal Bypass

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    Objective: This study aims to compare the 5-year outcomes of endoluminal bypass (EB) using heparin-bonded self-expanding covered stents versus bypass surgery for extensive femoropopliteal disease, including technical and clinical outcomes and health status. Background: The surgical femoropopliteal bypass was the gold standard to treat peripheral arterial disease (PAD) for decades; however, endovascular treatment modalities are now recommended for most femoropopliteal lesions. One-year data of a randomized controlled trial comparing EB with surgical bypass (SB) have shown a faster recovery, less morbidity, and comparable patency rates between the two techniques. To date, long-term randomized controlled data regarding both techniques are lacking. Methods: Five-year results of a multicenter randomized controlled trial comparing EB with SB in patients with femoropopliteal artery disease were evaluated based on intention-to-treat and per-protocol analyses. Results: At 5-year follow-up, primary, primary-assisted, and secondary patency rates were 36.2%, 52.4%, and 68.1% for EB and 49.4%, 72.2%, and 77.8% for SB, respectively (p=0.608). Freedom from target lesion revascularization (fTLR) was 34.1% for EB and 57.6% for SB (p=0.365). In both groups, the ankle-brachial index, Rutherford classification, and walking distance significantly improved compared with baseline without differences between groups at follow-up. Freedom from major amputation rate was 92.6% in the EB group and 96.2% in the SB group (p=0.361). The 36-Item Short-Form Health Survey showed no significant differences between groups. Conclusion: Treatment of extensive femoropopliteal disease with self-expanding covered stents provides comparable clinical-related and health-related questionnaire outcomes when compared with SB through 5 years of follow-up. However, the EB is related to a higher number of reinterventions. Clinical Impact: This present study is the first to report five-year outcomes comparing an endoluminal (EB) using heparin-bonded self-expanding covered stents with surgical bypass (SB) for long and complex femoropopliteal disease. Although the advantages of treatment with EB are mostly seen in the early period after treatment, the outcomes support the use of EB for this indication and seems to be a valid and safe alternative for bypass surgery. Future trials comparing various endovascular strategies may provide further guidance for the development of an evidence-based treatment algorithm.</p

    LERW as an example of off-critical SLEs

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    Two dimensional loop erased random walk (LERW) is a random curve, whose continuum limit is known to be a Schramm-Loewner evolution (SLE) with parameter kappa=2. In this article we study ``off-critical loop erased random walks'', loop erasures of random walks penalized by their number of steps. On one hand we are able to identify counterparts for some LERW observables in terms of symplectic fermions (c=-2), thus making further steps towards a field theoretic description of LERWs. On the other hand, we show that it is possible to understand the Loewner driving function of the continuum limit of off-critical LERWs, thus providing an example of application of SLE-like techniques to models near their critical point. Such a description is bound to be quite complicated because outside the critical point one has a finite correlation length and therefore no conformal invariance. However, the example here shows the question need not be intractable. We will present the results with emphasis on general features that can be expected to be true in other off-critical models.Comment: 45 pages, 2 figure

    Time-ordering and a generalized Magnus expansion

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    Both the classical time-ordering and the Magnus expansion are well-known in the context of linear initial value problems. Motivated by the noncommutativity between time-ordering and time derivation, and related problems raised recently in statistical physics, we introduce a generalization of the Magnus expansion. Whereas the classical expansion computes the logarithm of the evolution operator of a linear differential equation, our generalization addresses the same problem, including however directly a non-trivial initial condition. As a by-product we recover a variant of the time ordering operation, known as T*-ordering. Eventually, placing our results in the general context of Rota-Baxter algebras permits us to present them in a more natural algebraic setting. It encompasses, for example, the case where one considers linear difference equations instead of linear differential equations
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