Learning curve in robotic-assisted lobectomy for non-small cell lung cancer is not steep after experience in video-assisted lobectomy; single-surgeon experience using cumulative sum analysis

Publisher Copyright: © 2021Background: Robotic assistance in lung lobectomy has been suggested to enhance the adoption of minimally invasive techniques among surgeons. However, little is known of learning curves in different minimally invasive techniques. We studied learning curves in robotic-assisted versus video- assisted lobectomies for lung cancer. Methods: A single surgeon performed his first 75 video-assisted thoracic surgery (VATS) lobectomies from April 2007 to November 2012, and his 75 first robotic-assisted thoracic surgery (RATS) lobectomies between August 2011 and May 2018. A retrospective chart review was done. Cumulative sum (CUSUM) analysis was used to identify the learning curve. Results: No operative deaths occurred for VATS patients or RATS patients. Conversion-to-open rate was significantly lower in the RATS group (2.7% vs. 13.3%, p = 0.016). Meanwhile, 90-day mortality (1.3% vs. 5.3%, p = 0.172), postoperative complications (24% vs. 24%, p = 0.999), re- operation rates (4% vs. 5.3%, p = 0.688), operation time (170±56 min vs. 178±66 min, p = 0.663) and length of stay (8.9 ± 7.9 days vs. 8.2 ± 5.8 days, p = 0.844) were similar between the two groups. Based on CUSUM analysis, learning curves were similar for both procedures, although slightly shorter for RATS (proficiency obtained with 53 VATS cases vs. 45 RATS cases, p = 0.198). Conclusions: Robotic-assisted thoracoscopic lung lobectomy can be implemented safely and efficiently in an expert center with earlier experience in VATS lobectomies. However, there seems to be a learning curve of its own despite the surgeon's previous experience in conventional thoracoscopic surgery.Peer reviewe

Strategisches Handeln von Startups im Kontext der Mediatisierung

Junge Gründer und Start-ups müssen sich in einer schnell wandelnden und mediatisierten Wettbewerbsumwelt behaupten. Ihr Handeln wird geprägt von sozialen Netzwerkmedien wie Facebook, LinkedIn oder Instagram. Um auf diesen Medien-plattformen erfolgreich zu sein, müssen Markenführung und Markenkommunikation strategisch verankert sein. Der Aufsatz präsentiert daher eine qualitative Analyse empirischer Daten aus dem Kontext des Start-up-Incubator neudeli der Bauhaus-Universität Weimar und verdeutlicht, dass die Mediatisierung grundlegend in die strategische Entwicklung der Marke von jungen Gründern und Start-ups eingreift. Die Studie verdeutlicht das Verständnis strategischer Markenführung in mediatisierten Kontexten und zeigt, dass drei idealtypische Praktiken zur Markenführung und strategischen Entwicklung beitragen: 1) Bürokratische Medienarbeit, 2) Mediale Kreativarbeit, 3) Netzwerkarbeit durch Medien

Polythermal glacier studies in Svalbard determined by ground-penetrating radar

Abstract The overall aim of this Thesis is to emphasise how Ground Penetrating Radar (GPR) can be used in different glaciological studies: in mapping the inner structure, determining accumulation rates, estimating water contents, mapping drainage channels and superimposed ice. The Thesis also aims to improve current knowledge on Svalbard polythermal glaciers: their hydrothermal properties, drainage and behaviour in the changing climate. Six glaciers were studied: four tidewater glaciers, one ice-field and one valley glacier. The hydrothermal structure of Hansbreen was mapped with GPR at high lateral and vertical resolution. The hydrothermal structure of the glacier is highly variable and complex. In general the temperate ice contains 1-2% water, but water contents of about 4% are associated with englacial water channels or water-filled near surface crevasses or moulins. Hydrothermal properties determined from detailed GPR surveys of Hansbreen, Werenskioldbreen, Nordenskjöldbreen and Kongsvegen show similar structures such as foliations and superimposed ice in the firn-ice transition area, though with different emphasis on each glacier. The overall extent of superimposed ice was difficult to measure accurately because of the limited resolution and the sporadic nature of the reflections. However there is encouraging similarity between GPR and satellite imagery of superimposed ice extent. Hydraulic geometry models of the subglacial hydrology of Hansbreen and Werenskioldbreen suggest that the water pressure is generally close to ice-overburden pressure but varies greatly depending on local conditions. GPR data and data from three ice-cores were used to determine spatial and temporal variation of snow accumulation on a longitudinal profile of Nordenskjöldbreen. Spatial variations of 40-60% in snow accumulation over short distances along the profile were observed. The results indicate a 12% increase in accumulation rate during the late 1980s and 1990s. Hornbreen and Hambergbreen and several surrounding glaciers in southern Svalbard were mapped with GPR together with a DGPS (Differential Global Positioning System) in 2000. The data were compared to glacier surface height and glacier front length data from 1936 and 1901. The results show that the low-lying glaciated valley filled with Hornbreen and Hambergbreen may become a partially inundated ice-free isthmus within the next 100-150 years

GPR investigations of glacier and sea ice in the Scandinavian arctic

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Novel polypyrrole-coated polylactide scaffolds enhance adipose stem cell proliferation and early osteogenic differentiation

An electrically conductive polypyrrole (PPy) doped with a bioactive agent is an emerging functional biomaterial for tissue engineering. We therefore used chondroitin sulfate (CS)-doped PPy coating to modify initially electrically insulating polylactide resulting in novel osteogenic scaffolds. In situ chemical oxidative polymerization was used to obtain electrically conductive PPy coating on poly-96L/4D-lactide (PLA) nonwoven scaffolds. The coated scaffolds were characterized and their electrical conductivity was evaluated in hydrolysis. The ability of the coated and conductive scaffolds to enhance proliferation and osteogenic differentiation of human adipose stem cells (hASCs) under electrical stimulation (ES) in three-dimensional (3D) geometry was compared to the noncoated PLA scaffolds. Electrical conductivity of PPy-coated PLA scaffolds (PLA-PPy) was evident at the beginning of hydrolysis, but decreased during the first week of incubation due to de-doping. PLA-PPy scaffolds enhanced hASC proliferation significantly compared to the plain PLA scaffolds at 7 and 14 days. Furthermore, the alkaline phosphatase (ALP) activity of the hASCs was generally higher in PLA-PPy seeded scaffolds, but due to patient variation, no statistical significance could be determined. ES did not have a significant effect on hASCs. This study highlights the potential of novel PPy-coated PLA scaffolds in bone tissue engineering