202 research outputs found

    Surgical Outcomes after Full Thickness Chest Wall Resection Followed by Immediate Reconstruction:A 7-Year Observational Study of 42 Cases

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    Introduction: Reconstruction of full thickness chest wall defects is challenging and is associated with a considerable risk of complications. Therefore, the aim of this study was to investigate the surgical outcomes and their associations with patient and treatment characteristics following full thickness chest wall reconstruction. Patients and methods: A retrospective observational study was performed by including patients who underwent reconstruction of full thickness chest wall defect at the Erasmus MC between January 2014 and December 2020. The type of reconstruction was categorized into skeletal and soft tissue reconstructions. For skeletal reconstruction, only non-rigid prosthetic materials were used. Patient and surgical characteristics were retrieved and analyzed for associations with postoperative complications. Results: Thirty-two women and 10 men with a mean age of 60 years were included. In 26 patients (61.9%), the reconstruction was performed using prosthetic material and a soft tissue flap, in nine cases (21.4%) only a soft tissue flap was used, and in seven other patients (16.7%) only the prosthetic material was used. Pedicled musculocutaneous latissimus dorsi flaps were used most often (n=17), followed by pectoralis major flaps (n=8) and free flaps (n=8). Twenty-two patients (52.4%) developed at least one postoperative complication. Wounds (21.4%) and pulmonary (19.0%) complications occurred most frequently. Five (11.9%) patients required reoperation. There were no associations between patient and treatment characteristics and the occurrence of major complications. There was no mortality. Conclusions: Reconstruction of full thickness chest wall defects using only non-rigid prosthetic material for skeletal reconstruction appears safe with an acceptable reoperation rate and low mortality, questioning the need for rigid fixation techniques.</p

    Surgical Outcomes after Full Thickness Chest Wall Resection Followed by Immediate Reconstruction:A 7-Year Observational Study of 42 Cases

    Get PDF
    Introduction: Reconstruction of full thickness chest wall defects is challenging and is associated with a considerable risk of complications. Therefore, the aim of this study was to investigate the surgical outcomes and their associations with patient and treatment characteristics following full thickness chest wall reconstruction. Patients and methods: A retrospective observational study was performed by including patients who underwent reconstruction of full thickness chest wall defect at the Erasmus MC between January 2014 and December 2020. The type of reconstruction was categorized into skeletal and soft tissue reconstructions. For skeletal reconstruction, only non-rigid prosthetic materials were used. Patient and surgical characteristics were retrieved and analyzed for associations with postoperative complications. Results: Thirty-two women and 10 men with a mean age of 60 years were included. In 26 patients (61.9%), the reconstruction was performed using prosthetic material and a soft tissue flap, in nine cases (21.4%) only a soft tissue flap was used, and in seven other patients (16.7%) only the prosthetic material was used. Pedicled musculocutaneous latissimus dorsi flaps were used most often (n=17), followed by pectoralis major flaps (n=8) and free flaps (n=8). Twenty-two patients (52.4%) developed at least one postoperative complication. Wounds (21.4%) and pulmonary (19.0%) complications occurred most frequently. Five (11.9%) patients required reoperation. There were no associations between patient and treatment characteristics and the occurrence of major complications. There was no mortality. Conclusions: Reconstruction of full thickness chest wall defects using only non-rigid prosthetic material for skeletal reconstruction appears safe with an acceptable reoperation rate and low mortality, questioning the need for rigid fixation techniques.</p

    Emergence of scale-free close-knit friendship structure in online social networks

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    Despite the structural properties of online social networks have attracted much attention, the properties of the close-knit friendship structures remain an important question. Here, we mainly focus on how these mesoscale structures are affected by the local and global structural properties. Analyzing the data of four large-scale online social networks reveals several common structural properties. It is found that not only the local structures given by the indegree, outdegree, and reciprocal degree distributions follow a similar scaling behavior, the mesoscale structures represented by the distributions of close-knit friendship structures also exhibit a similar scaling law. The degree correlation is very weak over a wide range of the degrees. We propose a simple directed network model that captures the observed properties. The model incorporates two mechanisms: reciprocation and preferential attachment. Through rate equation analysis of our model, the local-scale and mesoscale structural properties are derived. In the local-scale, the same scaling behavior of indegree and outdegree distributions stems from indegree and outdegree of nodes both growing as the same function of the introduction time, and the reciprocal degree distribution also shows the same power-law due to the linear relationship between the reciprocal degree and in/outdegree of nodes. In the mesoscale, the distributions of four closed triples representing close-knit friendship structures are found to exhibit identical power-laws, a behavior attributed to the negligible degree correlations. Intriguingly, all the power-law exponents of the distributions in the local-scale and mesoscale depend only on one global parameter -- the mean in/outdegree, while both the mean in/outdegree and the reciprocity together determine the ratio of the reciprocal degree of a node to its in/outdegree.Comment: 48 pages, 34 figure

    A Fast Panel Code for Complex Actuator Disk Flows

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    A fast, linear scaling vortex method is presented to study inviscid incompressible flow problems involving one or more actuator disks. Building upon previous efforts that were limited to axi-symmetric flow cases, the proposed methodology is able to handle arbitrary configurations with no symmetry constraints. Applications include the conceptual study of wake interaction mechanisms in wind farms, and the correction of wind tunnel blockage effects in test sections of arbitrary shape. Actuator disks represent wind turbines through the shedding of a deformable vortex wake, discretized with a plaid of triangular distributed dipole singularities. An iterative method is adopted to align the wake with the local flow field, which is reconstructed from the vorticity field with a Green function approach. Interactions are computed with a Fast Multipole Method (FMM), effectively overcoming the quadratic scaling of computational time associated with traditional panel methods. When compared to direct computation, the use of an FMM algorithm reduced solution time by a factor 30 when studying the wake of a single actuator disk with 60000 panels. In the same case, the mass flux of the actuator streamtube was conserved to 0:002%. Finally, the presence of round and square impermeable walls around the actuator is considered to demonstrate the code applicability to wind tunnel wall interference correction problems

    Spawning of bluefin tuna in the black sea: historical evidence, environmental constraints and population plasticity

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    <div><p>The lucrative and highly migratory Atlantic bluefin tuna, <em>Thunnus thynnus</em> (Linnaeus 1758<em>;</em> Scombridae), used to be distributed widely throughout the north Atlantic Ocean, Mediterranean Sea and Black Sea. Its migrations have supported sustainable fisheries and impacted local cultures since antiquity, but its biogeographic range has contracted since the 1950s. Most recently, the species disappeared from the Black Sea in the late 1980s and has not yet recovered. Reasons for the Black Sea disappearance, and the species-wide range contraction, are unclear. However bluefin tuna formerly foraged and possibly spawned in the Black Sea. Loss of a locally-reproducing population would represent a decline in population richness, and an increase in species vulnerability to perturbations such as exploitation and environmental change. Here we identify the main genetic and phenotypic adaptations that the population must have (had) in order to reproduce successfully in the specific hydrographic (estuarine) conditions of the Black Sea. By comparing hydrographic conditions in spawning areas of the three species of bluefin tunas, and applying a mechanistic model of egg buoyancy and sinking rate, we show that reproduction in the Black Sea must have required specific adaptations of egg buoyancy, fertilisation and development for reproductive success. Such adaptations by local populations of marine fish species spawning in estuarine areas are common as is evident from a meta-analysis of egg buoyancy data from 16 species of fish. We conclude that these adaptations would have been necessary for successful local reproduction by bluefin tuna in the Black Sea, and that a locally-adapted reproducing population may have disappeared. Recovery of bluefin tuna in the Black Sea, either for spawning or foraging, will occur fastest if any remaining locally adapted individuals are allowed to survive, and by conservation and recovery of depleted Mediterranean populations which could through time re-establish local Black Sea spawning and foraging.</p> </div

    Pentecostalism, economics, capitalism: putting the Protestant Ethic to work

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    In recent years, academic interest in the nexus between Pentecostalism, economics, and capitalism has grown significantly. Notably, the vast majority of publications that have addressed this interface are to some degree conceptually framed by Max Weber’s The Protestant Ethic and the Spirit of Capitalism. In this article I consider what The Protestant Ethic might contribute to our understanding of the relationship between Pentecostalism and capitalism. First, I assess a particularly noteworthy attempt to draw Pentecostalism into Weber’s genealogical account which draws a series of parallels between Pentecostalism and ascetic Protestantism. Second, I discuss the merits of an approach that is not primarily genealogical but remains indebted to the concepts that Weber introduces, elaborating a new affinity between Pentecostalism and capitalism in its present iteration. With this article, I seek to comprehensively extend the scope and sharpen the conceptual underpinnings of future analysis and empirical work in this area

    Efficacy of a decision aid in breast cancer patients considering immediate reconstruction: results of a randomized controlled trial

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    PURPOSE: Breast cancer patients face complex decisions about immediate breast reconstruction (BR) after mastectomy. We evaluated the efficacy of an online decision aid in improving the decision-making process, decision quality and health outcomes in breast cancer patients considering immediate BR. METHODS: In a multicenter randomized controlled trial, patients were allocated to either the intervention group receiving care-as-usual (CAU) with access to an online decision aid, or the control group receiving CAU with an information leaflet. The primary outcome was decisional conflict. Secondary outcomes assessed the process of decision making (e.g. preparation for decision making, satisfaction with information), decision quality (decision regret, knowledge) and health outcomes (e.g. satisfaction with BR outcomes, body image). Patients completed questionnaires at baseline (T0), 1 week after consultation with a plastic surgeon (T1), 3 months (T2), and 12 months post-surgery (T3). RESULTS: We included 250 patients. Decisional conflict decreased over time in both groups, with no between group differences. Intervention participants felt better prepared for decision making than controls (P = .002). At T2, 87% of intervention participants were (very) satisfied with the information about BR, compared to 73% of control participants (P = .011). No significant between group differences were observed in any other outcome. CONCLUSION: Our online decision aid was as effective in reducing decisional conflict as an information leaflet about immediate BR after mastectomy. However, the decision aid substantially improved the decision-making process by better preparing breast cancer patients for decisions about immediate BR
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