1,308 research outputs found

    Endovascular repair for acute traumatic transection of the descending thoracic aorta: experience of a single centre with a 12-years follow up

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    Background: Most blunt aortic injuries occur in the proximal proximal descending aorta causing acute transection of this vessel. Generally, surgical repair of the ruptured segment of aorta is associated with high rates of morbidity and mortality and in this view endovascular treatment seems to be a valid and safer alternative. Aim of this article is to review our experience with endovascular approach for the treatment of acute traumatic rupture of descending thoracic aorta. Methods: From April 2002 to November 2014, 11 patients (9 males and 2 females) were referred to our Department with a diagnosis of acute transection of thoracic aorta. Following preoperative Computed Tomography (CT) evaluation, thoracic endovascular aortic repair (TEVAR) with left subclavian artery coverage was performed. Follow-up consisted clinical and instrumental (CT, Duplex ultrasound) controls at discharge, 1, 3 and 6 months and yearly thereafter. Results: At 12-year follow up, the overall survival for the entire patients cohort was 100 %, no major or minor neurological complications and no episode of left arm claudication occurred. Cardiovascular, respiratory and bleeding complications, in the early period, was represented by minor, non fatal events. No stent graft failure, collapse, leak or distal migration were detected at CT scan during the entire follow up period. Conclusions: According to our experience, despite the small number of patient population, TEVAR procedure with with left subclavian artery coverage, performed in emergency settings, seems to provide excellent long term results. Trials registration: The protocol was registered at a public trials registry, www.clinicaltrials.gov (trial identifier NCT02376998)

    Spatio-temporal Bounded Noises, and transitions induced by them in solutions of real Ginzburg-Landau model

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    In this work, we introduce two spatio-temporal colored bounded noises, based on the zero-dimensional Cai-Lin and Tsallis-Borland noises. We then study and characterize the dependence of the defined bounded noises on both a temporal correlation parameter τ\tau and on a spatial coupling parameter λ\lambda. The boundedness of these noises has some consequences on their equilibrium distributions. Indeed in some cases varying λ\lambda may induce a transition of the distribution of the noise from bimodality to unimodality. With the aim to study the role played by bounded noises on nonlinear dynamical systems, we investigate the behavior of the real Ginzburg-Landau time-varying model additively perturbed by such noises. The observed phase transitions phenomenology is quite different from the one observed when the perturbations are unbounded. In particular, we observed an inverse "order-to-disorder" transition, and a re-entrant transition, with dependence on the specific type of bounded noise.Comment: 12 (main text)+5 (supplementary) page

    Unstable Dynamics, Nonequilibrium Phases and Criticality in Networked Excitable Media

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    Here we numerically study a model of excitable media, namely, a network with occasionally quiet nodes and connection weights that vary with activity on a short-time scale. Even in the absence of stimuli, this exhibits unstable dynamics, nonequilibrium phases -including one in which the global activity wanders irregularly among attractors- and 1/f noise while the system falls into the most irregular behavior. A net result is resilience which results in an efficient search in the model attractors space that can explain the origin of certain phenomenology in neural, genetic and ill-condensed matter systems. By extensive computer simulation we also address a relation previously conjectured between observed power-law distributions and the occurrence of a "critical state" during functionality of (e.g.) cortical networks, and describe the precise nature of such criticality in the model.Comment: 18 pages, 9 figure

    Impact of monopolar and bipolar endometrial resection on abnormal uterine bleeding

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    Study Objective. To compare two procedures for endometrial resection: resectoscopy with monopolar knife versus resectoscopy with bipolar knife. Patients and methods. 76 perimenopausal patients affected by DUB (Dysfunctional Uterine Bleeding), no longer wishing to remain pregnant and having failed to respond to pharmacological treatment, underwent endometrial ablation with monopolar loop (group A: 38 women) or bipolar loop (group B: 38 women). Operative parameters, complication rate, menstrual outcome were considered. Results. Operative time was no different between groups. The amount of distention fluid adsorbed was significantly higher in group A than in group B, and late cumulative complication rate was 44% in group A and 24% in group B. Menstrual cycle was, overall, controlled in both groups. Conclusions. Bipolar electrode is as effective as monopolar electrode for endometrial resection, but was safer than monopolar knif

    Gonadotrophin-releasing hormone analogue or dienogest plus estradiol valerate to prevent pain recurrence after laparoscopic surgery for endometriosis: a multi-center randomized trial.

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    Abstract Objectives To evaluate the efficacy of dienogest + estradiol valerate (E2V) and gonadotrophin-releasing hormone analogue (GnRH-a) in reducing recurrence of pain in patients with chronic pelvic pain due to laparoscopically diagnosed and treated endometriosis. Design Multi-center, prospective, randomized study. Setting Three university departments of obstetrics and gynecology in Italy. Population Seventy-eight women who underwent laparoscopic surgery for endometriosis combined with chronic pelvic pain. Methods Post-operative administration of dienogest + E2V for 9 months (group 1) or GnRH-a monthly for 6 months (group 2). Main outcome measures A visual analogue scale was used to test intensity of pain before laparoscopic surgery at 3, 6 and 9 months of follow up. A questionnaire to investigate quality of life was administered before surgery and at 9 months of follow up. Results The visual analogue scale score did not show any significant differences between the two groups (p = 0.417). The questionnaire showed an increase of scores for all women compared with pre-surgery values, demonstrating a marked improvement in quality of life and health-related satisfaction with both treatments. No significant differences were found between the groups. The rate of apparent endometriosis recurrence was 10.8% in group 1 and 13.7% in group 2 (p = 0.962). Conclusion Both therapies seemed equally efficacious in preventing endometriosis-related chronic pelvic pain recurrence in the first 9 months of follow-up

    Self-organization without conservation: Are neuronal avalanches generically critical?

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    Recent experiments on cortical neural networks have revealed the existence of well-defined avalanches of electrical activity. Such avalanches have been claimed to be generically scale-invariant -- i.e. power-law distributed -- with many exciting implications in Neuroscience. Recently, a self-organized model has been proposed by Levina, Herrmann and Geisel to justify such an empirical finding. Given that (i) neural dynamics is dissipative and (ii) there is a loading mechanism "charging" progressively the background synaptic strength, this model/dynamics is very similar in spirit to forest-fire and earthquake models, archetypical examples of non-conserving self-organization, which have been recently shown to lack true criticality. Here we show that cortical neural networks obeying (i) and (ii) are not generically critical; unless parameters are fine tuned, their dynamics is either sub- or super-critical, even if the pseudo-critical region is relatively broad. This conclusion seems to be in agreement with the most recent experimental observations. The main implication of our work is that, if future experimental research on cortical networks were to support that truly critical avalanches are the norm and not the exception, then one should look for more elaborate (adaptive/evolutionary) explanations, beyond simple self-organization, to account for this.Comment: 28 pages, 11 figures, regular pape
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