385 research outputs found

    Controlling Dynamic Stability and Active Compliance to Improve Quadrupedal Walking

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    Summary. It is widespread the idea that animal legged locomotion improves wheeled locomotion on very rough terrain. However, the use of legs as locomotion system for vehicles and robots is still far away from competing with wheels and trucks even on natural ground. Walking robots feature two main disadvantages. One is the lack of reacting capabilities from external disturbances, and the other is the very slow walking motion. Both obstacles prevent walking mechanisms from being introduced in industrial processes and from being part of service and assistance robotics. This paper is aimed at solving the two above obstacles by combining a dynamic stability margin that quantifies the impact energy that a robot can withstand, and either controlling a dynamic walk by means of active compliance, which helps the robot react to disturbances. Experiments performed on the SILO4 quadruped robot show a relevant improvement on the walking gait.This work has been partially funded by CICYT (Spain) through Grant DPI2004-05824. The first author is supported by a postdoctoral CSIC-I3P contract granted by the European Social Fund.Peer reviewe

    Endoscopic submucosal dissection for early esophageal squamous cell carcinoma:long-term results from a Western cohort

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    Background Although endoscopic submucosal dissection (ESD) is established as first-choice treatment for early esophageal squamous cell carcinoma (ESCC) worldwide, most data are derived from Asian studies. We aimed to evaluate the long-term outcomes of ESD for patients with early ESCC in a Western cohort. Methods In this retrospective cohort study, patients with early ESCC amenable to ESD were included from four tertiary referral hospitals in the Netherlands between 2012 and 2017. All ESD procedures were performed by experienced endoscopists, after which the decision for additional treatment was made on a per-patient basis. Outcomes were curative resection rate, ESCC-specific survival, and overall survival. Results Of 68 included patients (mean age 69 years; 34 males), ESD was technically successful in 66 (97%; 95%CI 93%-100%), with curative resection achieved in 34/66 (52%; 95%CI 39%-64%). Among patients with noncurative resection, 15/32 (47%) underwent additional treatment, mainly esophagectomy (n = 10) or definitive chemoradiation therapy (n = 4). Endoscopic surveillance was preferred in 17/32 patients (53%), based on severe comorbidities or patient choice. Overall, 31/66 patients (47%) died during a median follow-up of 66 months; 8/31 (26%) were ESCC-related deaths. The 5-year overall and ESCC-specific survival probabilities were 62% (95%CI 52%-75%) and 86% (95%CI 77%-96%), respectively. Conclusion In this Western cohort with long-term follow-up, the effectiveness and safety of ESD for early ESCC was confirmed, although the rate of noncurative resections was substantial. Irrespective of curative status, the long-term prognosis of these patients was limited mainly due to competing mortality

    European Guideline on Achalasia - UEG and ESNM recommendations

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    Altres ajuts: These guidelines have been developed and funded within the United European Gastroenterology.Achalasia is a primary motor disorder of the oesophagus characterised by absence of peristalsis and insufficient lower oesophageal sphincter relaxation. With new advances and developments in achalasia management, there is an increasing demand for comprehensive evidence-based guidelines to assist clinicians in achalasia patient care. Guidelines were established by a working group of representatives from United European Gastroenterology, European Society of Neurogastroenterology and Motility, European Society of Gastrointestinal and Abdominal Radiology, and the European Association of Endoscopic Surgery in accordance with the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument. A systematic review of the literature was performed and the certainty of the evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology. Recommendations were voted upon using a nominal group technique. These guidelines focus on the definition of achalasia, treatment aims, diagnostic tests, medical, endoscopic and surgical therapy, management of treatment failure, follow-up and oesophageal cancer risk. These multidisciplinary guidelines provide a comprehensive evidence-based framework with recommendations on the diagnosis, treatment and follow-up of adult achalasia patients

    Novel cryoballoon 180° ablation system for treatment of Barrett's esophagus-related neoplasia:a first-in-human study

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    Background The novel 180 degrees cryoballoon (CbAS (180) ) enables semicircumferential treatment over a length of 3cm per application. This first-in-human study evaluates its feasibility, efficacy, and safety for the treatment of Barrett's esophagus (BE) neoplasia. Methods This multicenter study consisted of dose-finding and extension phases. Dose-finding started with the lowest dose possible (1.0mm/s). For each dose, six patients were treated circumferentially over a 3-cm length. The dose was increased until the median BE regression was >= 60% without serious adverse events (SAEs). In the extension phase, the dose was confirmed in 19 new patients. The outcomes were technical success, BE regression after one treatment, and SAEs. Results 25 patients (median Prague C0M3) were included (6 dose-finding/19 extension). In two patients, the CbAS (180) could not be applied because of unstable balloon positioning. The technical success rate was 96% (22/23). In the six dose-finding patients, the starting dose resulted in median BE regression of 94% (95% confidence interval [CI] 60%-97%) without SAEs and was thus considered effective. Overall median BE regression was 80% (95%CI 60%-90%). Conclusion Single-session CbAS (180) seems feasible, safe, and effective, and is a promising technique for the treatment of patients with BE neoplasia

    A novel cryoballoon ablation system for eradication of dysplastic Barrett's esophagus:a first-in-human feasibility study

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    BACKGROUND:  Endoscopic cryoablation for Barrett's esophagus (BE) might offer advantages over heat-based ablation. Focal cryoballoon ablation has been promising for short-segment BE, whereas the novel 90°-swipe cryoballoon ablation system (CbSAS90) ablates larger areas in a single step (90° over 3 cm). The system allows for dose adjustment. CbSAS90 has been feasible and safe in animal and pre-esophagectomy studies. This is the first clinical study to assess feasibility, safety, and efficacy of CbSAS90 for eradication of dysplastic BE. METHODS:  In this prospective study in dysplastic BE patients, dose finding started with semi-circumferential treatment at 0.8 mm/s (dose 1). The dose was escalated by reducing speed by 0.1 mm/s in six patients until BE surface regression was ≥ 80 % without complications ("effective dose"). The effective dose was subsequently confirmed with circumferential treatment in 12 new patients. Post-procedural pain (0 - 10) and dysphagia (0 - 4) were evaluated. Outcomes were feasibility, safety, and BE surface regression. RESULTS:  25 patients were included, with technically successful treatment in 92 % (95 %CI 73 % - 99 %). Median (95 %CI) BE surface regression was 78 % (50 % - 85 %) for dose 1 and 85 % (55 % - 95 %) for dose 2 (0.7 mm/s), which was defined as the effective dose. Circumferential treatment resulted in 93 % (88 % - 96 %) regression. Two of 12 patients with circumferential treatment developed strictures that required dilation. Median pain and dysphagia scores were low (0 - 3 and 0, respectively). CONCLUSIONS: CbSAS90 was feasible and effective for ablating larger BE areas. The optimal dose for circumferential treatment that balances safety and efficacy requires further evaluation

    Еволюція історичних уявлень про Україну в середньовічній Франції до середини ХVІІ ст.

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    У статті розглянуто стан ознайомлення французької громадськості ХІ-ХVІІ ст. з Україною, проаналізовано причини цікавості французів до цієї країни на тлі історичних взаємин України та Франції. Автор простежує еволюцію французьких історичних досліджень про Україну у Франції.The author considers the state of acquaintance of the French society of the XVII century with Ukraine, analyses the reasons of the interest the French took in this country on the phone of the historical relations between Ukraine and France and traces the evolution of the French historical studies in Ukraine

    Endoscopic Resection Without Subsequent Ablation Therapy for Early Barrett's Neoplasia:Endoscopic Findings and Long-Term Mortality

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    INTRODUCTION: After endoscopic resection (ER) of neoplasia in Barrett's esophagus (BE), it is recommended to ablate the remaining BE to minimize the risk for metachronous disease. However, we report long-term outcomes for a nationwide cohort of all patients who did not undergo ablation of the remaining BE after ER for early BE neoplasia, due to clinical reasons or performance status. METHODS: Endoscopic therapy for BE neoplasia in the Netherlands is centralized in 8 expert centers with specifically trained endoscopists and pathologists. Uniformity is ensured by a joint protocol and regular group meetings. We report all patients who underwent ER for a neoplastic lesion between 2008 and 2018, without further ablation therapy. Outcomes include progression during endoscopic FU and all-cause mortality. RESULTS: Ninety-four patients were included with mean age 74 (± 10) years. ER was performed for low-grade dysplasia (LGD) (10%), high-grade dysplasia (HGD) (25%), or low-risk esophageal adenocarcinoma (EAC) (65%). No additional ablation was performed for several reasons; in 73 patients (78%), the main argument was expected limited life expectancy. Median C2M5 BE persisted after ER, and during median 21 months (IQR 11-51) with 4 endoscopies per patient, no patient progressed to advanced cancer. Seventeen patients (18%) developed HGD/EAC: all were curatively treated endoscopically. In total, 29/73 patients (40%) with expected limited life expectancy died due to unrelated causes during FU, none of EAC. CONCLUSION: In selected patients, ER monotherapy with endoscopic surveillance of the residual BE is a valid alternative to eradication therapy with ablation

    Extending treatment criteria for Barrett's neoplasia:results of a nationwide cohort of 138 ESDs

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    BACKGROUND:  The use of endoscopic submucosal dissection (ESD) is gradually expanding for treatment of neoplasia in Barrett's esophagus (BE). We aimed to report outcomes of all ESDs for BE neoplasia performed in the Netherlands. METHODS:  Retrospective assessment of outcomes, using treatment and follow-up data from a joint database. RESULTS:  130/138 patients had complete ESDs, with 126/130 (97 %) en bloc resections. Median (interquartile range (IQR)) procedure time was 121 minutes (90-180). Pathology findings were high grade dysplasia (HGD) (5 %) or esophageal adenocarcinoma (EAC) T1a (43 %) or T1b (52 %; 19 % sm1, 33 % ≥ sm2). Among resections of HGD or T1a EAC lesions, 87 % (95 %CI 75 %-92 %) were both en bloc and R0; the corresponding value for T1b EAC lesions was 49 % (36 %-60 %). Among R1 resections, 10/34 (29 %) showed residual cancer, all detected at first endoscopic follow-up. The remaining 24 patients (71 %) showed no residual neoplasia. Six of these patients underwent surgery with no residual tumor; the remaining 18 underwent endoscopic follow-up during median 31 months with 1 local recurrence (annual recurrence rate 2 %). Among R0 resections, annual local recurrence rate during median 27 months was 0.5 %. CONCLUSION:  In expert hands, ESD allows safe removal of bulky intraluminal neoplasia and submucosal cancer. ESD of the latter showed R1 resection margins in 50 %, yet only one third had persisting neoplasia at follow-up. To better stratify R1 patients with an indication for additional surgery, repeat endoscopy after healing of the ESD might be a helpful possible prognostic factor for residual cancer

    Analysis of metastases rates during follow-up after endoscopic resection of early "high-risk" esophageal adenocarcinoma

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    BACKGROUND AND AIMS: After endoscopic resection (ER) of early esophageal adenocarcinoma (EAC), the optimal management of patients with high-risk histological features for lymph node metastases (LNM) (i.e., submucosal invasion, poor differentiation grade, or lymphovascular invasion (LVI)), remains unclear. We aimed to evaluate outcomes of endoscopic follow-up after ER for high-risk EAC. METHODS: For this retrospective cohort study, data was collected from all Dutch patients managed with endoscopic follow-up (endoscopy, endoscopic ultrasound) after ER for high-risk EAC between 2008 and 2019. We distinguished 3 groups: intramucosal cancers with high-risk features, submucosal cancers with low-risk features, and submucosal cancers with high-risk features. Primary outcome was the annual risk for metastases during follow-up, stratified for baseline histology. RESULTS: A total of 120 patients met the selection criteria. Median FU was 29 months (IQR 15-48). Metastases were observed in 5/25 (annual risk 6.9%; 95% CI 3.0-15), 1/55 (annual risk 0.7%; 95% CI 0-4.0) and 3/40 (annual risk 3.0%; 95% CI 0-7.0) in high-risk intramucosal, low-risk submucosal, and high-risk submucosal cancers, respectively. CONCLUSIONS: Whereas the annual metastasis rate for high-risk submucosal EAC (3.0%) was somewhat lower than expected in comparison with previous reported percentages, the annual metastasis rate of 6.9% for high-risk intramucosal EAC is new and worrisome. This calls for further prospective studies and suggests that strict follow-up of this small subgroup is warranted until prospective data are available
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