282 results on '"van Zuijlen, P."'
Search Results
2. Automatic mental simulation in native and non-native speakers
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van Zuijlen, Samuel J. A., Singh, Sharon, Gunawan, Kevin, Pecher, Diane, and Zeelenberg, René
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- 2024
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3. Uniaxial mechanical stretch properties correlated with three-dimensional microstructure of human dermal skin
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Zhou, Mengyao, González, Patrick José, Van Haasterecht, Ludo, Soylu, Alperen, Mihailovski, Maria, Van Zuijlen, Paul, and Groot, Marie Louise
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- 2024
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4. Weakly self-avoiding walk in a pareto-distributed random potential
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König, Wolfgang, Pétrélis, Nicolas, Santos, Renato Soares dos, and van Zuijlen, Willem
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Mathematics - Probability - Abstract
We investigate a model of continuous-time simple random walk paths in $\mathbb{Z}^d$ undergoing two competing interactions: an attractive one towards the large values of a random potential, and a self-repellent one in the spirit of the well-known weakly self-avoiding random walk. We take the potential to be i.i.d.~Pareto-distributed with parameter $\alpha>d$, and we tune the strength of the interactions in such a way that they both contribute on the same scale as $t\to\infty$. Our main results are (1) the identification of the logarithmic asymptotics of the partition function of the model in terms of a random variational formula, and, (2) the identification of the path behaviour that gives the overwhelming contribution to the partition function for $\alpha>2d$: the random-walk path follows an optimal trajectory that visits each of a finite number of random lattice sites for a positive random fraction of time. We prove a law of large numbers for this behaviour, i.e., that all other path behaviours give strictly less contribution to the partition function. The joint distribution of the variational problem and of the optimal path can be expressed in terms of a limiting Poisson point process arising by a rescaling of the random potential. The latter convergence is in distribution and is in the spirit of a standard extreme-value setting for a rescaling of an i.i.d. potential in large boxes, like in \cite{KLMS09}.
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- 2023
5. The Early Childhood Development of Pediatric Burn Patients
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Maxime D. Cuijpers, Moniek Akkerman, Martin G. A. Baartmans, Paul P. M. van Zuijlen, and Anouk Pijpe
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burns ,children ,development ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 ,Nursing ,RT1-120 - Abstract
Our study aimed to provide a description of the early childhood development of pediatric burn patients relative to Dutch reference values, using both pre- and post-burn data from the Dutch Development Instrument and the D-score. Data from the Dutch Development Instrument were used to calculate the D-score and age-standardized D-score. Similar to a growth chart, the D-score was used to plot pediatric burn patients’ development relative to Dutch reference values for their age. Pediatric burn patients’ (n = 38) median age at the time of injury was 1.0 (1.0–2.0) years old. Burn size ranged from 1.0% to 36.0% of the total body surface area. Ninety-five percent (± 6.0%) of pediatric burn patients passed each of the age-appropriate developmental milestones at the target age. The mean age-standardized D-score was just above the Dutch average (+0.49 SD [0.18, 0.80]) and did not vary depending on sex (p = 0.06) or burn size (p = 0.41). In conclusion, among pediatric patients aged up to two-and-a-half years old, with non-full thickness burns, development was on track relative to the Dutch reference values. Our findings offer valuable first insights into the early childhood development of pediatric burn patients and may alleviate some parental concerns.
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- 2024
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6. Anderson Hamiltonians with singular potentials
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Matsuda, Toyomu and van Zuijlen, Willem
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Mathematics - Probability ,Mathematics - Spectral Theory ,Primary. 60H17, 60H25, 60L40, 82B44. Secondary. 35J10, 35P15 - Abstract
We construct random Schr\"odinger operators, called Anderson Hamiltonians, with Dirichlet and Neumann boundary conditions for a fairly general class of singular random potentials on bounded domains. Furthermore, we construct the integrated density of states of these Anderson Hamiltonians, and we relate the Lifschitz tails (the asymptotics of the left tails of the integrated density of states) to the left tails of the principal eigenvalues., Comment: Main text 48 pages. Appendix contains 33 pages (in total 81 pages)
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- 2022
7. Residual-based error estimation and adaptivity for stabilized immersed isogeometric analysis using truncated hierarchical B-splines
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Divi, Sai C., van Zuijlen, Pieter H., Hoang, Tuong, de Prenter, Frits, Auricchio, Ferdinando, Reali, Alessandro, van Brummelen, E. Harald, and Verhoosel, Clemens V.
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Mathematics - Numerical Analysis ,Mathematical Physics - Abstract
We propose an adaptive mesh refinement strategy for immersed isogeometric analysis, with application to steady heat conduction and viscous flow problems. The proposed strategy is based on residual-based error estimation, which has been tailored to the immersed setting by the incorporation of appropriately scaled stabilization and boundary terms. Element-wise error indicators are elaborated for the Laplace and Stokes problems, and a THB-spline-based local mesh refinement strategy is proposed. The error estimation .and adaptivity procedure is applied to a series of benchmark problems, demonstrating the suitability of the technique for a range of smooth and non-smooth problems. The adaptivity strategy is also integrated in a scan-based analysis workflow, capable of generating reliable, error-controlled, results from scan data, without the need for extensive user interactions or interventions., Comment: Submitted to Journal of Mechanics
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- 2022
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8. Where two keloids meet: Invasive confluent growth of chest keloids, a case report
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Grace C. Limandjaja, Rosemarijn E. van Meijeren-Hoogendoorn, Juliette M.I.M. Louter, Antoine J.M. van Trier, Frank B. Niessen, Albert Wolkerstorfer, Susan Gibbs, and Paul P.M. van Zuijlen
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Keloids ,Growth ,Confluent ,Invasive ,Case report ,Dermatology ,RL1-803 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Keloids are differentiated from hypertrophic scars by their invasive lateral growth vs. the expansive growth of hypertrophic scars. This case report demonstrates the dynamic nature of keloids and the importance of clinical follow-up on its natural progression over time, especially when differentiation from hypertrophic scars is difficult. Serial photographic documentation is an invaluable aid for follow-up evaluation.
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- 2024
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9. Timing of surgery in acute deep partial-thickness burns: A study protocol.
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Roos F C Salemans, Denise van Uden, Margriet E van Baar, Tjitske M Haanstra, Carine H M van Schie, Paul P M van Zuijlen, Ymke Lucas, Sonja M H J Scholten-Jaegers, Annebeth Meij-de Vries, Fiona M Wood, Dale W Edgar, Inge Spronk, Cornelis H van der Vlies, and National Burn Care, Education & Research group, the Netherlands
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Medicine ,Science - Abstract
For deep partial-thickness burns no consensus on the optimal treatment has been reached due to conflicting study outcomes with low quality evidence. Treatment options in high- and middle-income countries include conservative treatment with delayed excision and grafting if needed; and early excision and grafting. The majority of timing of surgery studies focus on survival rather than on quality of life. This study protocol describes a study that aims to compare long-term scar quality, clinical outcomes, and patient-reported outcomes between the treatment options. A multicentre prospective study will be conducted in the three Dutch burn centres (Rotterdam, Beverwijk, and Groningen). All adult patients with acute deep-partial thickness burns, based on healing potential with Laser Doppler Imaging, are eligible for inclusion. During a nine-month baseline period, standard practice will be monitored. This includes conservative treatment with dressings and topical agents, and excision and grafting of residual defects if needed 14-21 days post-burn. The subsequent nine months, early surgery is advocated, involving excision and grafting in the first week to ten days post-burn. The primary outcome compared between the two groups is long-term scar quality assessed by the Patient and Observer Scar Assessment Scale 3.0 twelve months after discharge. Secondary outcomes include clinical outcomes and patient-reported outcomes like quality of life and return to work. The aim of the study is to assess long-term scar quality in deep partial-thickness burns after conservative treatment with delayed excision and grafting if needed, compared to early excision and grafting. Adding to the ongoing debate on the optimal treatment of these burns. The broad range of studied outcomes will be used for the development of a decision aid for deep partial-thickness burns, to fully inform patients at the point of consent to surgery and support optimal person-centred care.
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- 2024
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10. An in silico modeling approach to understanding the dynamics of the post-burn immune response
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H. Ibrahim Korkmaz, Vivek M. Sheraton, Roland V. Bumbuc, Meifang Li, Anouk Pijpe, Patrick P. G. Mulder, Bouke K. H. L. Boekema, Evelien de Jong, Stephan G. F. Papendorp, Ruud Brands, Esther Middelkoop, Peter M. A. Sloot, and Paul P. M. van Zuijlen
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burns ,wound healing ,inflammation ,immune response ,computational modeling ,Immunologic diseases. Allergy ,RC581-607 - Abstract
IntroductionBurns are characterized by a massive and prolonged acute inflammation, which persists for up to months after the initial trauma. Due to the complexity of the inflammatory process, Predicting the dynamics of wound healing process can be challenging for burn injuries. The aim of this study was to develop simulation models for the post-burn immune response based on (pre)clinical data.MethodsThe simulation domain was separated into blood and tissue compartments. Each of these compartments contained solutes and cell agents. Solutes comprise pro-inflammatory cytokines, anti-inflammatory cytokines and inflammation triggering factors. The solutes diffuse around the domain based on their concentration profiles. The cells include mast cells, neutrophils, and macrophages, and were modeled as independent agents. The cells are motile and exhibit chemotaxis based on concentrations gradients of the solutes. In addition, the cells secrete various solutes that in turn alter the dynamics and responses of the burn wound system.ResultsWe developed an Glazier-Graner-Hogeweg method-based model (GGH) to capture the complexities associated with the dynamics of inflammation after burn injuries, including changes in cell counts and cytokine levels. Through simulations from day 0 – 4 post-burn, we successfully identified key factors influencing the acute inflammatory response, i.e., the initial number of endothelial cells, the chemotaxis threshold, and the level of chemoattractants.ConclusionOur findings highlight the pivotal role of the initial endothelial cell count as a key parameter for intensity of inflammation and progression of acute inflammation, 0 – 4 days post-burn.
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- 2024
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11. 20th Congress of the European Burns Association (EBA)
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Nadia Depetris, Alette De Jong, Clemens Schiestl, Franck Duteille, Jill Meirte, Joan P. Barret-Nerin, Paul Van Zuijlen, Jyrki Vuola, and Stian Almeland
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burns ,burn care ,burn center ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 ,Nursing ,RT1-120 - Abstract
Abstracts of the plenary and special interest sessions, workshops, and oral and poster presentations of the 20th EBA Congress in Nantes, France from 6–9 September 2023.
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- 2023
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12. Mastoid obliteration with hydroxyapatite vs. bone pâté in mastoidectomy surgery performed on patients with cholesteatoma and chronic suppurative otitis media: a retrospective analysis
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Lindeboom, Jantine J., van Kempen, P. M. W., Buwalda, J., Westerlaken, B. O., van Zuijlen, D. A., Bom, S. J. H., and van der Beek, F. B.
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- 2023
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13. Outcomes that matter most to burn patients: A national multicentre survey study in the Netherlands
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Spronk, I., van Uden, D., van Dammen, L., van Baar, M.E., Nieuwenhuis, M., Pijpe, A., Visser, I., van Schie, C., van Zuijlen, P., Haanstra, T., and Lansdorp, C.A.
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- 2024
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14. Thermal Imaging for Burn Wound Depth Assessment: A Mixed-Methods Implementation Study
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Jesse de Haan, Matthea Stoop, Paul P. M. van Zuijlen, and Anouk Pijpe
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thermography ,burn assessment ,burn centre ,healing potential ,implementation ,Medicine - Abstract
Background: Implementing innovations emerging from clinical research can be challenging. Thermal imagers provide an accessible diagnostic tool to increase the accuracy of burn wound depth assessment. This mixed-methods implementation study aimed to assess the barriers and facilitators, design implementation strategies, and guide the implementation process of thermal imaging in the outpatient clinic of a burn centre. Methods: This study was conducted between September 2022 and February 2023 in Beverwijk, The Netherlands. Semi-structured interviews with burn physicians guided by the Consolidated Framework for Implementation Research (CFIR) were conducted to identify barriers and facilitators. Based on the barriers, implementation strategies were developed with the CFIR-ERIC Matching Tool, and disseminated to support the uptake of the thermal imager. Subsequently, thermal imaging was implemented in daily practice, and an iterative RE-AIM approach was used to evaluate the implementation process. Results: Common facilitators for the implementation of the thermal imager were the low complexity, the relative advantage above other diagnostic tools, and benefits for patients. Common barriers were physicians’ attitude towards and perceived value of the intervention, the low compatibility with the current workflow, and a lack of knowledge about existing evidence. Six implementation strategies were developed: creating a formal implementation blueprint, promoting adaptability, developing educational materials, facilitation, conducting ongoing training, and identifying early adopters. These strategies resulted in the effective implementation of the thermal imager, reflected by a >70% reach among eligible patients, and >80% effectiveness and adoption. Throughout the implementation process, compatibility, and available resources remained barriers, resulting in low ratings on RE-AIM dimensions. Conclusions: This study developed implementation strategies based on the identified CFIR constructs that impacted the implementation of a thermal imager for burn wound assessment in our outpatient clinic. The experiences and findings of this study could be leveraged to guide the implementation of thermal imaging and other innovations in burn care.
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- 2024
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15. Materials In Paintings (MIP): An interdisciplinary dataset for perception, art history, and computer vision
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van Zuijlen, Mitchell J. P., Lin, Hubert, Bala, Kavita, Pont, Sylvia C., and Wijntjes, Maarten W. A.
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Computer Science - Human-Computer Interaction - Abstract
A painter is free to modify how components of a natural scene are depicted, which can lead to a perceptually convincing image of the distal world. This signals a major difference between photos and paintings: paintings are explicitly created for human perception. Studying these painterly depictions could be beneficial to a multidisciplinary audience. In this paper, we capture and explore the painterly depictions of materials to enable the study of depiction and perception of materials through the artists' eye. We annotated a dataset of 19k paintings with 200k+ bounding boxes from which polygon segments were automatically extracted. Each bounding box was assigned a coarse label (e.g., fabric) and a fine-grained label (e.g., velvety, silky). We demonstrate the cross-disciplinary utility of our dataset by presenting novel findings across art history, human perception, and computer vision. Our experiments include analyzing the distribution of materials depicted in paintings, showing how painters create convincing depictions using a stylized approach, and demonstrating how paintings can be used to build more robust computer vision models. We conclude that our dataset of painterly material depictions is a rich source for gaining insights into the depiction and perception of materials across multiple disciplines. The MIP dataset is freely accessible at https://materialsinpaintings.tudelft.nl
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- 2020
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16. What Can Style Transfer and Paintings Do For Model Robustness?
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Lin, Hubert, van Zuijlen, Mitchell, Pont, Sylvia C., Wijntjes, Maarten W. A., and Bala, Kavita
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Computer Science - Computer Vision and Pattern Recognition - Abstract
A common strategy for improving model robustness is through data augmentations. Data augmentations encourage models to learn desired invariances, such as invariance to horizontal flipping or small changes in color. Recent work has shown that arbitrary style transfer can be used as a form of data augmentation to encourage invariance to textures by creating painting-like images from photographs. However, a stylized photograph is not quite the same as an artist-created painting. Artists depict perceptually meaningful cues in paintings so that humans can recognize salient components in scenes, an emphasis which is not enforced in style transfer. Therefore, we study how style transfer and paintings differ in their impact on model robustness. First, we investigate the role of paintings as style images for stylization-based data augmentation. We find that style transfer functions well even without paintings as style images. Second, we show that learning from paintings as a form of perceptual data augmentation can improve model robustness. Finally, we investigate the invariances learned from stylization and from paintings, and show that models learn different invariances from these differing forms of data. Our results provide insights into how stylization improves model robustness, and provide evidence that artist-created paintings can be a valuable source of data for model robustness., Comment: CVPR 2021
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- 2020
17. Insights From A Large-Scale Database of Material Depictions In Paintings
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Lin, Hubert, Van Zuijlen, Mitchell, Wijntjes, Maarten W. A., Pont, Sylvia C., and Bala, Kavita
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Computer Science - Computer Vision and Pattern Recognition - Abstract
Deep learning has paved the way for strong recognition systems which are often both trained on and applied to natural images. In this paper, we examine the give-and-take relationship between such visual recognition systems and the rich information available in the fine arts. First, we find that visual recognition systems designed for natural images can work surprisingly well on paintings. In particular, we find that interactive segmentation tools can be used to cleanly annotate polygonal segments within paintings, a task which is time consuming to undertake by hand. We also find that FasterRCNN, a model which has been designed for object recognition in natural scenes, can be quickly repurposed for detection of materials in paintings. Second, we show that learning from paintings can be beneficial for neural networks that are intended to be used on natural images. We find that training on paintings instead of natural images can improve the quality of learned features and we further find that a large number of paintings can be a valuable source of test data for evaluating domain adaptation algorithms. Our experiments are based on a novel large-scale annotated database of material depictions in paintings which we detail in a separate manuscript., Comment: International Workshop on Fine Art Pattern Extraction and Recognition, ICPR 2020
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- 2020
18. A one-dimensional morphoelastic model for burn injuries: stability analysis, numerical validation and biological interpretation
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Egberts, Ginger, Vermolen, Fred, and van Zuijlen, Paul
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Mathematics - Numerical Analysis ,Physics - Biological Physics ,Quantitative Biology - Tissues and Organs ,35B20, 35B35, 35G20, 35L65, 35M10, 35Q74, 35Q80, 35Q92, 35R37, 65C05, 65C20, 65M12, 65M60, 65N12, 65N30, 74-10, 74L15, 92-10, 92C10, 92C17, 92C45 - Abstract
To deal with permanent deformations and residual stresses, we consider a morphoelastic model for the scar formation as the result of wound healing after a skin trauma. Next to the mechanical components such as strain and displacements, the model accounts for biological constituents such as the concentration of signaling molecules, the cellular densities of fibroblasts and myofibroblasts, and the density of collagen. Here we present stability constraints for the one-dimensional counterpart of this morphoelastic model, for both the continuous and (semi-) discrete problem. We show that the truncation error between these eigenvalues associated with the continuous and semi-discrete problem is of order $\mathcal{O}(h^2)$. Next, we perform numerical validation to these constraints and provide a biological interpretation of the (in)stability. For the mechanical part of the model, the results show the components reach equilibria in a (non) monotonic way, depending on the value of the viscosity. The results show that the parameters of the chemical part of the model need to meet the stability constraint, depending on the decay rate of the signaling molecules, to avoid unrealistic results., Comment: 38 pages, 5 figures
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- 2020
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19. A one-dimensional morphoelastic model for burn injuries: sensitivity analysis and a feasibility study
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Egberts, Ginger, Vermolen, Fred, and van Zuijlen, Paul
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Mathematics - Numerical Analysis ,Physics - Biological Physics ,Quantitative Biology - Tissues and Organs - Abstract
We consider a one-dimensional morphoelastic model describing post-burn scar contraction. This model describes the displacement of the dermal layer of the skin and the development of the effective Eulerian strain in the tissue. Besides these components, the model also contains components that play a major role in skin repair after trauma. These components are signaling molecules, fibroblasts, myofibroblasts, and collagen. We perform a sensitivity analysis for many parameters of the model and use the results for a feasibility study. In this study, we test whether the model is suitable for predicting the extent of contraction in different age groups. To this end, we conduct an extensive literature review to find parameter values. From the sensitivity analysis, we conclude that the most sensitive parameters are the equilibrium collagen concentration in the dermal layer, the apoptosis rate of fibroblasts and myofibroblasts, and the secretion rate of signaling molecules. Further, although we can use the model to simulate distinct contraction densities in different age groups, our results differ from what is seen in the clinic.
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- 2020
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20. Development of the Patient Scale of the Patient and Observer Scar Assessment Scale (POSAS) 3.0: a qualitative study
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Carrière, M. E., Mokkink, L. B., Tyack, Z., Westerman, M. J., Pijpe, A., Pleat, J., van de Kar, A. L., Brown, J., de Vet, H. C. W., and van Zuijlen, P. P. M.
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- 2023
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21. Sensitivity of a two-dimensional biomorphoelastic model for post-burn contraction
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Egberts, Ginger, Desmoulière, Alexis, Vermolen, Fred, and van Zuijlen, Paul
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- 2023
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22. Three decades of environmental change studies at alpine Finse, Norway: climate trends and responses across ecological scales
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Ruben E. Roos, Johan Asplund, Tone Birkemoe, Aud H. Halbritter, Siri Lie Olsen, Linn Vassvik, Kristel van Zuijlen, and Kari Klanderud
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alpine ecosystems ,climate change ,experimental manipulation ,International Tundra Experiment ,open top chamber ,within-site synthesis ,Environmental sciences ,GE1-350 ,Environmental engineering ,TA170-171 - Abstract
The International Tundra Experiment (ITEX) was established to understand how environmental change impacts Arctic and alpine ecosystems. The success of the ITEX network has allowed for several important across-site syntheses, and for some ITEX sites enough data have now been collected to perform within-site syntheses on the effects of environmental change across ecological scales. In this study, we analyze climate data and synthesize three decades of research on the ecological effects of environmental change at the ITEX site at Finse, southern Norway. We found a modest warming rate of +0.36 °C per decade and minor effects on growing season length. Maximum winter snow depth was highest in winters with a positive North Atlantic Oscillation. Our synthesis included 80 ecological studies from Finse, biased towards primary producers with few studies on ecological processes. Species distributions depended on microtopography and microclimate. Experimental warming had contrasting effects on abundance and traits of individual species and only modest effects at the community level above and below ground. In contrast, nutrient addition experiments caused strong responses in primary producer and arthropod communities. This within-site synthesis enabled us to conclude how different environmental changes (experimental and ambient warming, nutrient addition, and environmental gradients) impact across ecological scales, which is challenging to achieve with across-site approaches.
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- 2023
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23. Longtime asymptotics of the two-dimensional parabolic Anderson model with white-noise potential
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König, Wolfgang, Perkowski, Nicolas, and van Zuijlen, Willem
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Mathematics - Probability - Abstract
We consider the parabolic Anderson model (PAM) $\partial_t u = \frac12 \Delta u + \xi u$ in $\mathbb R^2$ with a Gaussian (space) white-noise potential $\xi$. We prove that the almost-sure large-time asymptotic behaviour of the total mass at time $t$, written $U(t)$, is given by $\log U(t)\sim \chi t \log t$ for $t \to \infty$, with the deterministic constant $\chi$ identified in terms of a variational formula. In earlier work of one of the authors this constant was used to describe the asymptotic behaviour $\boldsymbol \lambda_1(Q_t)\sim\chi\log t$ of the principal eigenvalue $\boldsymbol\lambda_1(Q_t)$ of the Anderson operator with Dirichlet boundary conditions on the box $Q_t= [-\frac{t}{2},\frac{t}{2}]^2$.
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- 2020
24. Quantitative heat kernel estimates for diffusions with distributional drift
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Perkowski, Nicolas and van Zuijlen, Willem
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Mathematics - Probability - Abstract
We consider the stochastic differential equation on $\mathbb{R}^d$ given by $$ \, \mathrm{d}X_t = b(t,X_t) \, \mathrm{d}t + \, \mathrm{d} B_t, $$ where $B$ is a Brownian motion and $b$ is considered to be a distribution of regularity $ > -\frac12$. We show that the martingale solution of the SDE has a transition kernel $\Gamma_t$ and prove upper and lower heat kernel bounds for $\Gamma_t$ with explicit dependence on $t$ and the norm of $b$.
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- 2020
25. Sketch-and-test: picture-centered research with p5.js assisted crowdsourcing
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Wijntjes, Maarten W. A. and van Zuijlen, Mitchell
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Computer Science - Human-Computer Interaction - Abstract
Relating human judgements to pictures is central to a wide variety of scientific disciplines. Pictures are used to evoke and study faculties of the human mind, while human input is used to label, understand and model pictorial representations. Human input is often collected through online crowdsourcing experiments. This paper discusses the usage of crowdsourcing in two major branches of picture-centered research, human and computer vision, and identifies novel directions such as art history and design. We demonstrate that a wide variety of experiments can be conducted by using p5.js, a library originally intended to facilitate visual creation. We report five complementary experimental paradigms to illustrated the accessibility and versatility of p5.js: Change blindness, BubbleView, 3D shape perception, Composition, and Perspective reconstruction. Results reveal that literature findings can be reproduced and novel insights can easily be achieved with the p5.js library. The creative freedom of p5.js combined with low threshold access to crowdsourcing seems like a powerful combination for all picture-centred research areas: perception, design, art history, communication, and beyond.
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- 2020
26. Tomaszewski's problem on randomly signed sums, revisited
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Boppana, Ravi B., Hendriks, Harrie, and van Zuijlen, Martien C. A.
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Mathematics - Combinatorics ,Mathematics - Probability ,60C05, 05A20 - Abstract
Let $v_1$, $v_2$, ..., $v_n$ be real numbers whose squares add up to 1. Consider the $2^n$ signed sums of the form $S = \sum \pm v_i$. Boppana and Holzman (2017) proved that at least 13/32 of these sums satisfy $|S| \le 1$. Here we improve their bound to $0.427685$., Comment: Now with three authors. 4 pages
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- 2020
27. An improvement of the Boppana-Holzman bound for Rademacher random variables
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Hendriks, Harrie and van Zuijlen, Martien C. A.
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Mathematics - Combinatorics - Abstract
Let $v_1,v_2,...,v_n$ be real numbers whose squares add up to $1$. Consider the $2^n$ signed sums of the form $S=\sum_{i=1}^n \pm v_i.$ Holzman and Kleitman (1992) proved that at least $\frac38=0.375$ of these sums satisfy $|S|\leq 1.$ By using bounds for appropriate moments of $S,$ Boppana and Holzman (2017) were able to improve the bound to $\frac{13}{32}=0.40625$ and even a bit better to $\frac{13}{32}+9\times10^{-6}.$ By following their approach, but using a key result of Bentkus and Dzindzalieta (2015), we will drastically improve (by more than 5\%) the latter barrier $\frac{13}{32}$ to $\frac{1}{2}-\frac{\Phi(-2)}{4\Phi(-\sqrt{2})}\approx 0.42768.$, Comment: Corrected Lemma 2 and the statement of Corollary 3
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- 2020
28. Intralesional corticosteroid administration in the treatment of keloids: a survey among Dutch dermatologists and plastic surgeons
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Qi Yin, Frank B. Niessen, Susan Gibbs, Oren Lapid, Juliette M. I. Louter, Paul P. M. van Zuijlen, and Albert Wolkerstorfer
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keloid ,corticosteroid ,triamcinolone ,injection ,scar ,Dermatology ,RL1-803 - Abstract
Background Intralesional corticosteroid administration (ICA) is a first-line therapy in keloid treatment. However, its clinical results are still highly variable and often suboptimal. Treatment results may strongly be influenced by various ways of ICA. Objective To explore the prevailing practice of ICA in keloid treatment among dermatologists and plastic surgeons in the Netherlands. Methods The survey was constructed based on a scoping review on ICA in keloid treatment. Members of the Dutch Society for Plastic surgery and the Dutch Society for Dermatology and Venereology were asked to participate. Results One hundred and thirty-six responses were obtained. One hundred and thirty (95.6%) participants used triamcinolone acetonide. The majority (54.7%) did not use local anesthesia for pain reduction. Reported corticosteroid dosing that one would inject in one specific keloid differed by a factor of 40. Treatment intervals varied from 1 week to more than 8 weeks. The keloid center was most often injected (46.9%), followed by subepidermal (18.0%). Conclusions A wide variety in ICA for keloids is noted among dermatologists and plastic surgeons, even in a limited geographic region and when evidence points toward an optimal way of treatment. Future studies and better implementation of existing evidence may reduce variation in ICA and optimize its treatment results.
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- 2023
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29. Complications during Pregnancy after Abdominal Burn Scars: A Review
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Zosha J. van Gelder, Annabel Snoeks, Paul P.M. van Zuijlen, Ralph de Vries, and Anouk Pijpe
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information ,burns ,pregnancy ,scars ,complications ,abdominal ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 ,Nursing ,RT1-120 - Abstract
Over the past decades, long-term sequelae of burns have gained increasing attention. Women of childbearing age, who sustained abdominal burns earlier in life, may have unmet information needs on scar-related complications they can expect during pregnancy. We performed a review of the literature to identify abdominal, foetal, and potential other complications during pregnancy in women with abdominal burn scars. PubMed, Embase, and Scopus were searched from inception to 1 July 2020 and updated once on 23 April 2021 (PROSPERO CRD42022187883). Main search terms included pregnancy, scar, burns, and abdominal. Studies on burns obtained during pregnancy have been excluded. Screening, data extraction and bias assessment were conducted by two investigators. We included 22 studies comprising 217 patients. The time between burn injury and first pregnancy varied between 7 and 32 years. Most of the women had normal pregnancies regarding delivery mode and duration of pregnancy. The most reported abdominal burn scar complications were an increased feeling of tightness, itch, pain, and scar breakdown. In some cases, scar release surgery was performed during or prior to pregnancy. Some cases of foetal complications were described. Complications during pregnancy after abdominal burn scars may be limited. More quantitative and qualitative research is needed to assess the maternal and foetal outcomes and complications. The results may be used to inform women and contribute to personalised obstetric management.
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- 2023
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30. Efficacy of Alkaline Phosphatase in Critically Ill Patients with COVID-19: A Multicentre Investigator-Initiated Double-Blind Randomised Placebo-Controlled Trial
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Anouk Pijpe, Stephan G. Papendorp, Joost W. van der Heijden, Ben Vermin, Iris Ertugrul, Michael W. J. Ritt, Björn Stessel, Ina Callebaut, Albertus Beishuizen, Marcel Vlig, Joost Jimmink, Henk J. Huijgen, Paul P. M. van Zuijlen, Esther Middelkoop, and Evelien de Jong
- Subjects
alkaline phosphatase ,COVID-19 ,mechanical ventilation ,inflammatory response ,Biology (General) ,QH301-705.5 - Abstract
Background: Efforts to identify therapies to treat hospitalised patients with COVID-19 are being continued. Alkaline phosphatase (AP) dephosphorylates pro-inflammatory adenosine triphosphate (ATP) into anti-inflammatory adenosine. Methods: In a randomised controlled trial, we investigated the safety and efficacy of AP in patients with SARS-CoV-2 infection admitted to the ICU. AP or a placebo was administered for four days following admission to the ICU. The primary outcome was the duration of mechanical ventilation. Mortality in 28 days, acute kidney injury, need for reintubation, safety, and inflammatory markers relevant to the described high cytokine release associated with SARS-CoV-2 infection were the secondary outcomes. Results: Between December 2020 and March 2022, 97 patients (of the intended 132) were included, of which 51 were randomised to AP. The trial was terminated prematurely based on meeting the threshold for futility. Compared to the placebo, AP did not affect the duration of mechanical ventilation (9.0 days vs. 9.3 days, p = 1.0). No safety issues were observed. After 28 days, mortality was 9 (18%) in the AP group versus 6 (13%) in the placebo group (p = 0.531). Additionally, no statistically significant differences between the AP and the placebo were observed for the other secondary outcomes. Conclusions: Alkaline phosphatase (AP) therapy in COVID-19 ICU patients showed no significant benefits in this trial.
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- 2024
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31. Dynamic Mesh Simulations in OpenFOAM: A Hybrid Eulerian–Lagrangian Approach
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Rention Pasolari, Carlos Simão Ferreira, Alexander van Zuijlen, and Carlos Fernando Baptista
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OpenFOAM ,dynamic meshes ,hybrid Eulerian–Lagrangian solvers ,vortex particle methods ,Thermodynamics ,QC310.15-319 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
The past few decades have witnessed a growing popularity in Eulerian–Lagrangian solvers due to their significant potential for simulating aerodynamic flows, particularly in cases involving strong body–vortex interactions. In this hybrid approach, the two component solvers are mutually coupled in a two-way fashion. Initially, the Lagrangian solver can supply boundary conditions to the Eulerian solver, while the Eulerian solver functions as a corrector for the Lagrangian solution in regions where the latter cannot achieve high accuracy. To utilize such tools effectively, it is vital for them to be capable of handling dynamic mesh movements. This study builds upon the previous research conducted by our team and extends the capabilities of the hybrid solver to handle dynamic meshes. While OpenFOAM, the Eulerian component of this hybrid code, incorporates built-in dynamic mesh properties, certain modifications are necessary to ensure its compatibility with the Lagrangian solver. More specifically, the evolution algorithm of the pimpleFOAM solver needs to be divided into two discrete steps: first, updating the mesh, and later, evolving the solution. This division enables a proper coupling between pimpleFOAM and the Lagrangian solver as an intermediate step. Therefore, the primary objective of this specific paper is to adapt the OpenFOAM solver to meet the demands of the hybrid solver and subsequently validate that the hybrid solver can effectively address dynamic mesh challenges using this approach. This approach introduces a pioneering method for conducting dynamic mesh simulations within the OpenFOAM framework, showcasing its potential for broader applications. To validate the approach, various test cases involving dynamic mesh movements are employed. Specifically, all these cases employ the Lamb–Oseen diffusing vortex, but each case incorporates different types of mesh movements, including translational, rotational, oscillational, and combinations thereof. The results from these cases demonstrate the effectiveness of the proposed OpenFOAM algorithm, with the maximum relative errors —when compared to the analytical solution across all presented cases—capped at 2.0% for the worst-case scenario. This affirms the algorithm’s capability to successfully handle dynamic mesh simulations with the proposed solver.
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- 2024
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32. Asymptotics of the eigenvalues of the Anderson Hamiltonian with white noise potential in two dimensions
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Chouk, Khalil and van Zuijlen, Willem
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Mathematics - Probability ,Primary 60H25, 60F15, 35J10, 35P15, Secondary 60F10 - Abstract
In this paper we consider the Anderson Hamiltonian with white noise potential on the box $[0,L]^2$ with Dirichlet boundary conditions. We show that all the eigenvalues divided by $\log L$ converge as $L\rightarrow \infty$ almost surely to the same deterministic constant, which is given by a variational formula., Comment: This version to appear in Annals of Probability: https://imstat.org/journals-and-publications/annals-of-probability/
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- 2019
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33. Can bryophyte groups increase functional resolution in tundra ecosystems?1
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Signe Lett, Ingibjörg S. Jónsdóttir, Antoine Becker-Scarpitta, Casper T. Christiansen, Heinjo During, Flemming Ekelund, Gregory H.R. Henry, Simone I. Lang, Anders Michelsen, Kathrin Rousk, Juha M. Alatalo, Katlyn R. Betway, Sara B. Rui, Terry Callaghan, Michele Carbognani, Elisabeth J. Cooper, J. Hans C. Cornelissen, Ellen Dorrepaal, Dagmar Egelkraut, Tatiana G. Elumeeva, Siri V. Haugum, Robert D. Hollister, Annika K. Jägerbrand, Frida Keuper, Kari Klanderud, Esther Lévesque, Xin Liu, Jeremy May, Pascale Michel, Martin Mörsdorf, Alessandro Petraglia, Christian Rixen, Bjorn J.M. Robroek, Agnieszka M. Rzepczynska, Nadejda A. Soudzilovskaia, Anne Tolvanen, Vigdis Vandvik, Igor Volkov, Irina Volkova, and Kristel van Zuijlen
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mosses ,Arctic–Alpine ,environmental change ,functional traits ,water holding capacity ,mousses ,Environmental sciences ,GE1-350 ,Environmental engineering ,TA170-171 - Abstract
The relative contribution of bryophytes to plant diversity, primary productivity, and ecosystem functioning increases towards colder climates. Bryophytes respond to environmental changes at the species level, but because bryophyte species are relatively difficult to identify, they are often lumped into one functional group. Consequently, bryophyte function remains poorly resolved. Here, we explore how higher resolution of bryophyte functional diversity can be encouraged and implemented in tundra ecological studies. We briefly review previous bryophyte functional classifications and the roles of bryophytes in tundra ecosystems and their susceptibility to environmental change. Based on shoot morphology and colony organization, we then propose twelve easily distinguishable bryophyte functional groups. To illustrate how bryophyte functional groups can help elucidate variation in bryophyte effects and responses, we compiled existing data on water holding capacity, a key bryophyte trait. Although plant functional groups can mask potentially high interspecific and intraspecific variability, we found better separation of bryophyte functional group means compared with previous grouping systems regarding water holding capacity. This suggests that our bryophyte functional groups truly represent variation in the functional roles of bryophytes in tundra ecosystems. Lastly, we provide recommendations to improve the monitoring of bryophyte community changes in tundra study sites.
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- 2022
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34. Stromal vascular fraction-enriched fat grafting as treatment of adherent scars: study design of a non-randomized early phase trial
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Linda Vriend, Joris A. van Dongen, Anouk Pijpe, Marianne K. Nieuwenhuis, Sandra J. M. Jongen, Martin C. Harmsen, Paul P. M. van Zuijlen, and Berend van der Lei
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Adherent scars ,Scar quality ,Burn scars ,Stromal vascular fraction ,Adipose-derived stromal cells ,ASC ,Medicine (General) ,R5-920 - Abstract
Abstract Background In the last decades, autologous fat grafting has been used to treat adherent dermal scars. The observed regenerative and scar-reducing properties have been mainly ascribed to the tissue-derived stromal vascular fraction (tSVF) in adipose tissue. Adipose tissue’s components augment local angiogenesis and mitosis in resident tissue cells. Moreover, it promotes collagen remodeling. We hypothesize that tSVF potentiates fat grafting-based treatment of adherent scars. Therefore, this study aims to investigate the effect of tSVF-enriched fat grafting on scar pliability over a 12-month period. Methods and design A clinical multicenter non-randomized early phase trial will be conducted in two dedicated Dutch Burn Centers (Red Cross Hospital, Beverwijk, and Martini Hospital, Groningen). After informed consent, 46 patients (≥18 years) with adherent scars caused by burns, necrotic fasciitis, or degloving injury who have an indication for fat grafting will receive a sub-cicatricic tSVF-enriched fat graft. The primary outcome is the change in scar pliability measured by the Cutometer between pre- and 12 months post-grafting. Secondary outcomes are scar pliability (after 3 months), scar erythema, and melanin measured by the DSM II Colormeter; scar quality assessed by the patient and observer scales of the Patient and Observer Scar Assessment Scale (POSAS) 2.0; and histological analysis of scar biopsies (voluntary) and tSVF quality and composition. This study has been approved by the Dutch Central Committee for Clinical Research (CCMO), NL72094.000.20. Conclusion This study will test the clinical efficacy of tSVF-enriched fat grafting to treat dermal scars while the underlying working mechanism will be probed into too. Trial registration Dutch Trial Register NL 8461. Registered on 16 March 2020
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- 2022
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35. Approaches to Surgical Debridement in Necrotizing Soft Tissue Infections: Outcomes of an Animated, Interactive Survey
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Suijker, Jaco, Hofmans, Fabienne A. C., van Zuijlen, Paul P. M., Cense, Huib A., Bonjer, H. Jaap, and Vries, Annebeth Meij-de
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- 2022
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36. A Hamilton-Jacobi point of view on mean-field Gibbs-non-Gibbs transitions
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Kraaij, Richard C., Redig, Frank, and van Zuijlen, Willem B.
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Mathematics - Probability ,Condensed Matter - Statistical Mechanics ,49L99, 60F10, 82C22, 82C27 - Abstract
We study the loss, recovery, and preservation of differentiability of time-dependent large deviation rate functions. This study is motivated by mean-field Gibbs-non-Gibbs transitions. The gradient of the rate-function evolves according to a Hamiltonian flow. This Hamiltonian flow is used to analyze the regularity of the time-dependent rate function, both for Glauber dynamics for the Curie-Weiss model and Brownian dynamics in a potential. We extend the variational approach to this problem of time-dependent regularity in order to include Hamiltonian trajectories with a finite lifetime in closed domains with a boundary. This leads to new phenomena, such a recovery of smoothness. We hereby create a new and unifying approach for the study of mean-field Gibbs-non-Gibbs transitions, based on Hamiltonian dynamics and viscosity solutions of Hamilton-Jacobi equations., Comment: This version to appear in Trans. AMS. Minor changes in the introduction and a few minor corrections
- Published
- 2017
37. In vitro responses of human dermal fibroblasts to mechanical strain: A systematic review and meta-analysis
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L. van Haasterecht, C. Dsouza, Y. Ma, H. I. Korkmaz, Y. de Jong, J. C. F. Ket, P. P. M. van Zuijlen, M. L. Groot, and S. V. Komarova
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skin ,biomechanics ,keloid ,hypertrophic scar ,mechanotransduction ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
In vitro research in the field of mechanotransducive regulation of dermal fibroblasts is characterized by highly variable methodology and contradictory results. The primary objective of this systematic review was to establish how in vitro mechanical stretch affects human dermal fibroblast function, by means of a quantitative synthesis of all available evidence. The secondary objectives were to examine the effects of covariates related to donor age, fibroblast origin, experimental treatments, and mechanical stimulation parameters on dermal fibroblast responsiveness to mechanical strain. Summary outcomes for fibroblast proliferation and collagen production were combined using a fixed-effects meta-analytical model. Subgroup analysis and meta-regression were used to investigate the effects of different conditions on the summary outcomes. Mechanical strain was found to not affect fibroblast proliferation in neonatal fibroblasts, while adult fibroblasts proliferation was significantly increased. Collagen production was significantly increased in response to mechanical stimulation, with Vitamin C stimulation as the most important covariate. Stretching frequency emerged as positively associated with fibroblast proliferation and negatively associated with collagen production. We conclude from this study that distinct differences exist in the effects of mechanical stretching between dermal fibroblasts from neonatal and adult donors, which will help to further elucidate the pathophysiological mechanism behind tension-induced scarring.
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- 2023
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38. Outcomes of Meek micrografting versus mesh grafting on deep dermal and full thickness (burn) wounds: Study protocol for an intra-patient randomized controlled trial.
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Danielle Rijpma, Anouk Pijpe, Karel Claes, Henk Hoeksema, Ignace de Decker, Jozef Verbelen, Paul van Zuijlen, Stan Monstrey, and Annebeth Meij-de Vries
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Medicine ,Science - Abstract
IntroductionAutologous split thickness skin grafting is the standard-of-care for most deep dermal and full thickness skin defects. Historically, mesh grafting is used to expand skin grafts for smaller defects and other techniques such as Meek micrografting is used to enable expansion for larger skin defects. Yet, Meek micrografting is increasingly used for smaller skin defects as well. Both techniques are frequently used, especially in burn centers, but evidence on which one is preferable for relative smaller skin defects is lacking. Therefore, an intra-patient randomized controlled trial was designed to adequately compare multiple outcomes of the Meek micrografting and mesh grafting techniques.Materials and methodsA multicenter intra-patient controlled randomized trial is being performed in two burn centers (the Netherlands and Belgium) to compare multiple outcomes of Meek micrografting and mesh grafting burns or skin defects. Study registration number (NL74274.029.20). Adult patients with a (burn) wound and an indication for surgical excision and skin grafting were screened for inclusion. In total 70 patients will be included and the primary outcome is scar quality twelve months post-surgery assessed by the Patient and Observer Scar Assessment Scale. Moreover, graft take, re-epithelialization, infection rate, donor site size and patients' preference are also measured within hospital admission, on 3 months and 12 months post-surgery.DiscussionThis is the first randomized trial that is intra-patient controlled, which enables a proper comparison between both skin expansion techniques. The results of this study will contribute to the clarification of the indications of both techniques and ample attention is paid for the patients' opinion on the surgical treatment options.
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- 2023
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39. High-speed predictions of post-burn contraction using a neural network trained on 2D-finite element simulations
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Ginger Egberts, Fred Vermolen, and Paul van Zuijlen
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machine learning ,post-burn scar contraction ,morphoelasticity ,feed–forward neural network ,online application ,Monte Carlo simulations ,Applied mathematics. Quantitative methods ,T57-57.97 ,Probabilities. Mathematical statistics ,QA273-280 - Abstract
Severe burn injuries often lead to skin contraction, leading to stresses in and around the damaged skin region. If this contraction leads to impaired joint mobility, one speaks of contracture. To optimize treatment, a mathematical model, that is based on finite element methods, is developed. Since the finite element-based simulation of skin contraction can be expensive from a computational point of view, we use machine learning to replace these simulations such that we have a cheap alternative. The current study deals with a feed-forward neural network that we trained with 2D finite element simulations based on morphoelasticity. We focus on the evolution of the scar shape, wound area, and total strain energy, a measure of discomfort, over time. The results show average goodness of fit (R2) of 0.9979 and a tremendous speedup of 1815000X. Further, we illustrate the applicability of the neural network in an online medical app that takes the patient's age into account.
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- 2023
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40. Quantitative Heat-Kernel Estimates for Diffusions with Distributional Drift
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Perkowski, Nicolas and van Zuijlen, Willem
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- 2022
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41. Stromal vascular fraction-enriched fat grafting as treatment of adherent scars: study design of a non-randomized early phase trial
- Author
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Vriend, Linda, van Dongen, Joris A., Pijpe, Anouk, Nieuwenhuis, Marianne K., Jongen, Sandra J. M., Harmsen, Martin C., van Zuijlen, Paul P. M., and van der Lei, Berend
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- 2022
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42. Linear combinations of Rademacher random variables
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Hendriks, Harrie and van Zuijlen, Martien C. A.
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Mathematics - Combinatorics ,60C05, 05A20 - Abstract
For a fixed unit vector $a=(a_1,a_2,\ldots,a_n)\in S^{n-1}$, we consider the $2^n$ sign vectors $\varepsilon=(\varepsilon^1,\varepsilon^2,\ldots,\varepsilon^n)\in \{+1,-1\}^n$ and the corresponding scalar products $\varepsilon\cdot a=\sum_{i=1}^n \varepsilon^ia_i$. In this paper we will solve for $n=1,2,\ldots,9$ an old conjecture stating that of the $2^n$ sums of the form $\sum\pm a_i$ it is impossible that there are more with $|\sum_{i=1}^n \pm a_i|>1$ than there are with $|\sum_{i=1}^n \pm a_i|\leq1$. Although the problem has been solved completely in case the $a_i$'s are equal, the more general problem with possible non-equal $a_i$'s remains open for values of $n\geq 10$. The present method can also be used for $n\geq 10$, but unfortunately the technical difficulties seem to grow exponentially with $n$ and no "induction type of argument" has been found. The conjecture has an appealing reformulation in probability theory and in geometry. In probability theory the results lead to upper bounds which are much better than for instance Chebyshevnequalities., Comment: 15 pages
- Published
- 2017
43. Sensitivity and feasibility of a one-dimensional morphoelastic model for post-burn contraction
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Egberts, Ginger, Vermolen, Fred, and van Zuijlen, Paul
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- 2021
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44. Burn-injured skin is marked by a prolonged local acute inflammatory response of innate immune cells and pro-inflammatory cytokines
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Patrick P.G. Mulder, Marcel Vlig, Esther Fasse, Matthea M. Stoop, Anouk Pijpe, Paul P.M. van Zuijlen, Irma Joosten, Bouke K.H.L. Boekema, and Hans J.P.M. Koenen
- Subjects
cell isolation ,immune cells ,flow cytometry ,neutrophils ,lymphocytes ,macrophages ,Immunologic diseases. Allergy ,RC581-607 - Abstract
The systemic and local immune response in burn patients is often extreme and derailed. As excessive inflammation can damage healthy tissues and slow down the healing process, modulation of inflammatory responses could limit complications and improve recovery. Due to its complexity, more detailed information on the immune effects of thermal injury is needed to improve patient outcomes. We therefore characterized and quantified subsets of immune cells and mediators present in human burn wound tissue (eschar), sampled at various time points. This study shows that after burn injury, the number of immune cells were persistently increased, unlike the normal wound healing process. There was an immediate, strong increase in neutrophils and a moderate increase in monocytes/macrophages and lymphocytes, especially in the second and third week post burn. The percentage of classical (CD14highCD16-) monocytes/macrophages demonstrated a steady decrease over time, whereas the proportion of intermediate (CD14highCD16+) monocytes/macrophages slowly increased. The absolute numbers of T cells, NK cells and B cells increased up to week 3, while the fraction of γδ T cells was increased only in week 1. Secretome profiling revealed high levels of chemokines and an overall pro-inflammatory cytokine milieu in burn tissue. The local burn immune response shows similarities to the systemic immune reaction, but differs in neutrophil maturity and lymphocyte composition. Altogether, the neutrophil surges, high levels of pro-inflammatory cytokines and limited immunosuppression might be key factors that prolong the inflammation phase and delay the wound healing process in burns.
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- 2022
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45. Outcome measures to evaluate the function of the hand after burns; a clinical initiative
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Saskia J.M Sizoo, Margriet E. van Baar, Natasja Jelsma, Paul P.M. van Zuijlen, and Marianne K. Nieuwenhuis
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Burns ,Hand ,Outcome assessment ,ICF ,Dermatology ,RL1-803 ,Medical emergencies. Critical care. Intensive care. First aid ,RC86-88.9 - Abstract
Background: Outcome assessment is essential to understand the impact and recovery of burns of the hand and tailor treatment. There is however, a large variety of measures and outcome assessment is often incomplete. The aim was therefore to initiate a set of outcome assessments for use in a clinical setting. Method: A concept set was drafted, based on the framework of the International Classification of Functioning, which distinguished two phases, three patient states and included both patient reported and clinical outcomes. Subsequently, potential assessments were allocated to the various outcomes. This concept was discussed during the European Burns Association congress in 2013 and revised. The revision was sent to 65 colleagues from 28 institutions, accompanied by a survey. Results: Eleven surveys were returned from 16 persons representing 9 institutions from 6 countries. Based on the feedback, final revisions were made. Points raised were time investment and translations of not all assessments already available. Conclusions: With multidisciplinary and international input, a multidimensional set of outcome assessments for burns of the hand has been established, covering almost all domains of functioning. This first step towards more uniform clinical evaluation, will contribute to knowledge on outcome and effectiveness of treatment of hand burns.
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- 2021
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46. Large deviations of continuous regular conditional probabilities
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van Zuijlen, Willem
- Subjects
Mathematics - Probability - Abstract
We study product regular conditional probabilities under measures of two coordinates with respect to the second coordinate that are weakly continuous on the support of the marginal of the second coordinate. Assuming that there exists a sequence of probability measures on the product space that satisfies a large deviation principle, we present necessary and sufficient conditions for the conditional probabilities under these measures to satisfy a large deviation principle. The arguments of these conditional probabilities are assumed to converge. A way to view regular conditional probabilities as a special case of product regular conditional probabilities is presented. This is used to derive conditions for large deviations of regular conditional probabilities. In addition, we derive a Sanov-type theorem for large deviations of the empirical distribution of the first coordinate conditioned on fixing the empirical distribution of the second coordinate.
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- 2016
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47. Bochner integrals in ordered vector spaces
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van Rooij, Arnoud and van Zuijlen, Willem
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Mathematics - Functional Analysis - Abstract
We present a natural way to cover an Archimedean directed ordered vector space $E$ by Banach spaces and extend the notion of Bochner integrability to functions with values in $E$. The resulting set of integrable functions is an Archimedean directed ordered vector space and the integral is an order preserving map.
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- 2016
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48. Integrals for functions with values in a partially ordered vector space
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van Rooij, Arnoud and van Zuijlen, Willem
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Mathematics - Functional Analysis - Abstract
We consider integration of functions with values in a partially ordered vector space, and two notions of extension of the space of integrable functions. Applying both extensions to the space of real valued simple functions on a measure space leads to the classical space of integrable functions.
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- 2015
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49. The Complexity of the Post-Burn Immune Response: An Overview of the Associated Local and Systemic Complications
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H. Ibrahim Korkmaz, Gwendolien Flokstra, Maaike Waasdorp, Anouk Pijpe, Stephan G. Papendorp, Evelien de Jong, Thomas Rustemeyer, Susan Gibbs, and Paul P. M. van Zuijlen
- Subjects
burn ,immune response ,inflammation ,complexity ,Cytology ,QH573-671 - Abstract
Burn injury induces a complex inflammatory response, both locally and systemically, and is not yet completely unravelled and understood. In order to enable the development of accurate treatment options, it is of paramount importance to fully understand post-burn immunology. Research in the last decades describes insights into the prolonged and excessive inflammatory response that could exist after both severe and milder burn trauma and that this response differs from that of none-burn acute trauma. Persistent activity of complement, acute phase proteins and pro- and anti-inflammatory mediators, changes in lymphocyte activity, activation of the stress response and infiltration of immune cells have all been related to post-burn local and systemic pathology. This “narrative” review explores the current state of knowledge, focusing on both the local and systemic immunology post-burn, and further questions how it is linked to the clinical outcome. Moreover, it illustrates the complexity of post-burn immunology and the existing gaps in knowledge on underlying mechanisms of burn pathology.
- Published
- 2023
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50. Turbulence-induced vibrations prediction through use of an anisotropic pressure fluctuation model
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van den Bos Nout, Zwijsen Kevin, van Zuijlen Alexander H., Frederix Edo M.A, and Roelofs Ferry
- Subjects
Nuclear engineering. Atomic power ,TK9001-9401 - Abstract
In nuclear fuel rod bundles, turbulence-induced pressure fluctuations caused by an axial flow can create small but significant vibrations in the fuel rods, which in turn can cause structural effects such as material fatigue and fretting wear. Fluid-structure interaction simulations can be used to model these vibrations, but for affordable simulations based on the URANS approach, a model for the pressure fluctuations must be utilised. Driven by the goal to improve the current state-of-the-art pressure fluctuation model, AniPFM (Anisotropic Pressure Fluctuation Model) was developed. AniPFM can model velocity fluctuations based on anisotropic Reynolds stress tensors, with temporal correlation through the convection and decorrelation of turbulence. From these velocity fluctuations and the mean flow properties, the pressure fluctuations are calculated. The model was applied to several test cases and shows promising results in terms of reproducing qualitatively similar flow structures, as well as predicting the root-mean-squared pressure fluctuations. While further validation is being performed, the AniPFM has already demonstrated its potential for affordable simulations of turbulence-induced vibrations in industrial nuclear applications.
- Published
- 2023
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