TY - JOUR A1 - Tomasch, Janine A1 - Maleiner, Babette A1 - Heher, Philipp A1 - Rufin, Manuel A1 - Andriotis, Orestis G. A1 - Thurner, Philipp J. A1 - Redl, Heinz A1 - Fuchs, Christiane A1 - Teuschl-Woller, Andreas H. T1 - Changes in Elastic Moduli of Fibrin Hydrogels Within the Myogenic Range Alter Behavior of Murine C2C12 and Human C25 Myoblasts Differently JF - Froniers in Bioengineering and Biotechnology N2 - Fibrin hydrogels have proven highly suitable scaffold materials for skeletal muscle tissue engineering in the past. Certain parameters of those types of scaffolds, however, greatly affect cellular mechanobiology and therefore the myogenic outcome. The aim of this study was to identify the influence of apparent elastic properties of fibrin scaffolds in 2D and 3D on myoblasts and evaluate if those effects differ between murine and human cells. Therefore, myoblasts were cultured on fibrin-coated multiwell plates (“2D”) or embedded in fibrin hydrogels (“3D”) with different elastic moduli. Firstly, we established an almost linear correlation between hydrogels’ fibrinogen concentrations and apparent elastic moduli in the range of 7.5 mg/ml to 30 mg/ml fibrinogen (corresponds to a range of 7.7–30.9 kPa). The effects of fibrin hydrogel elastic modulus on myoblast proliferation changed depending on culture type (2D vs 3D) with an inhibitory effect at higher fibrinogen concentrations in 3D gels and vice versa in 2D. The opposite effect was evident in differentiating myoblasts as shown by gene expression analysis of myogenesis marker genes and altered myotube morphology. Furthermore, culture in a 3D environment slowed down proliferation compared to 2D, with a significantly more pronounced effect on human myoblasts. Differentiation potential was also substantially impaired upon incorporation into 3D gels in human, but not in murine, myoblasts. With this study, we gained further insight in the influence of apparent elastic modulus and culture type on cellular behavior and myogenic outcome of skeletal muscle tissue engineering approaches. Furthermore, the results highlight the need to adapt parameters of 3D culture setups established for murine cells when applied to human cells. KW - Tissue Engineering KW - Fibrin KW - Hydrogel KW - Biomaterials KW - Cell Culture Y1 - VL - 10 SP - 836520 ER - TY - JOUR A1 - Angelova, Liliya A1 - Daskalova, Albena A1 - Filipov, Emil A1 - Monforte Vila, Xavier A1 - Tomasch, Janine A1 - Avdeev, Georgi A1 - Teuschl-Woller, Andreas Herbert A1 - Buchvarov, Ivan T1 - Optimizing the Surface Structural and Morphological Properties of Silk Thin Films via Ultra-Short Laser Texturing for Creation of Muscle Cell Matrix Model JF - Polymers N2 - Temporary scaffolds that mimic the extracellular matrix's structure and provide a stable substratum for the natural growth of cells are an innovative trend in the field of tissue engineering. The aim of this study is to obtain and design porous 2D fibroin-based cell matrices by femtosecond laser-induced microstructuring for future applications in muscle tissue engineering. Ultra-fast laser treatment is a non-contact method, which generates controlled porosity-the creation of micro/nanostructures on the surface of the biopolymer that can strongly affect cell behavior, while the control over its surface characteristics has the potential of directing the growth of future muscle tissue in the desired direction. The laser structured 2D thin film matrices from silk were characterized by means of SEM, EDX, AFM, FTIR, Micro-Raman, XRD, and 3D-roughness analyses. A WCA evaluation and initial experiments with murine C2C12 myoblasts cells were also performed. The results show that by varying the laser parameters, a different structuring degree can be achieved through the initial lifting and ejection of the material around the area of laser interaction to generate porous channels with varying widths and depths. The proper optimization of the applied laser parameters can significantly improve the bioactive properties of the investigated 2D model of a muscle cell matrix. Keywords: biopolymers; femtosecond laser processing; muscle cell matrix 2D model; muscle tissue engineering; silk fibroin. KW - Tissue Engineering KW - Muscle Cell matrix Model KW - Silk Scaffold KW - Surface Structure Y1 - VL - 2022 IS - 14(13), 2584 ER - TY - JOUR A1 - Munsch, Nicolas A1 - Gruarin, Stefanie A1 - Nateqi, Jama A1 - Lutz, Thomas A1 - Binder, Michael A1 - Aberle, Judith H. A1 - Martin, Alistair A1 - Knapp, Bernhard T1 - Symptoms associated with a COVID-19 infection among a non-hospitalized cohort in Vienna JF - Wiener Klinische Wochenschrift / The Central European Journal of Medicine N2 - Background: Most clinical studies report the symptoms experienced by those infected with coronavirus disease 2019 (COVID-19) via patients already hospitalized. Here we analyzed the symptoms experienced outside of a hospital setting. Methods: The Vienna Social Fund (FSW; Vienna, Austria), the Public Health Services of the City of Vienna (MA15) and the private company Symptoma collaborated to implement Vienna's official online COVID-19 symptom checker. Users answered 12 yes/no questions about symptoms to assess their risk for COVID-19. They could also specify their age and sex, and whether they had contact with someone who tested positive for COVID-19. Depending on the assessed risk of COVID-19 positivity, a SARS-CoV‑2 nucleic acid amplification test (NAAT) was performed. In this publication, we analyzed which factors (symptoms, sex or age) are associated with COVID-19 positivity. We also trained a classifier to correctly predict COVID-19 positivity from the collected data. Results: Between 2 November 2020 and 18 November 2021, 9133 people experiencing COVID-19-like symptoms were assessed as high risk by the chatbot and were subsequently tested by a NAAT. Symptoms significantly associated with a positive COVID-19 test were malaise, fatigue, headache, cough, fever, dysgeusia and hyposmia. Our classifier could successfully predict COVID-19 positivity with an area under the curve (AUC) of 0.74. Conclusion: This study provides reliable COVID-19 symptom statistics based on the general population verified by NAATs. Keywords: Chatbot; Machine learning; Self-reported; Symptom assessment; Symptom checker. KW - COVID-19 KW - Chatbot KW - Machine learning KW - Self-reported KW - Symptom assessment Y1 - VL - 2022 IS - 134 (9-10) SP - 344 EP - 350 PB - Springer ER - TY - GEN A1 - Hrastansky, Thomas T1 - Phishing: Targeting YouTube Content Creators N2 - Vortrag im Zuge des Security Monats in Form des FHTW Security Potpourri 2022 KW - Phishing KW - IT-Security KW - YouTube Y1 - ER - TY - JOUR A1 - Kuba, Markus A1 - Panholzer, Alois T1 - On bucket increasing trees, clustered increasing trees and increasing diamonds JF - Combinatorics, Probability and Computing N2 - In this work we analyse bucket increasing tree families. We introduce two simple stochastic growth processes, generating random bucket increasing trees of size n, complementing the earlier result of Mahmoud and Smythe (1995, Theoret. Comput. Sci.144 221–249.) for bucket recursive trees. On the combinatorial side, we define multilabelled generalisations of the tree families d-ary increasing trees and generalised plane-oriented recursive trees. Additionally, we introduce a clustering process for ordinary increasing trees and relate it to bucket increasing trees. We discuss in detail the bucket size two and present a bijection between such bucket increasing tree families and certain families of graphs called increasing diamonds, providing an explanation for phenomena observed by Bodini et al. (2016, Lect. Notes Comput. Sci.9644 207–219.). Concerning structural properties of bucket increasing trees, we analyse the tree parameter Kn . It counts the initial bucket size of the node containing label n in a tree of size n and is closely related to the distribution of node types. Additionally, we analyse the parameters descendants of label j and degree of the bucket containing label j, providing distributional decompositions, complementing and extending earlier results (Kuba and Panholzer (2010), Theoret. Comput. Sci.411(34–36) 3255–3273.). KW - bucket-increasing-trees KW - clustered-trees KW - stochastic-growth-processes KW - descendants KW - nodedegrees Y1 - 2021 IS - Volume 31 , Issue 4 SP - 629 EP - 661 ER - TY - JOUR A1 - Huber, Albert T1 - Remark on the quasilocal calculation of tidal heating: Energy transfer through the quasilocal surface JF - American Physical Society - Physical Review D N2 - In this paper, using the quasilocal formalism of Brown and York, the flow of energy through a closed surface containing a gravitating physical system is calculated in a way that augments earlier results on the subject by Booth and Creighton. To this end, by performing a variation of the total gravitational Hamiltonian (bulk plus boundary part), it is shown that associated tidal heating and deformation effects generally are larger than expected. This is because the aforementioned variation leads to previously unrecognized correction terms, including a bulk-to-boundary inflow term that does not appear in the original calculation of the time derivative of the Brown-York energy and leads to corrective extensions of Einstein’s quadrupole formula in the large sphere limit. KW - gravitation KW - cosmology KW - fields Y1 - VL - 105 IS - 2 ER - TY - JOUR A1 - Mairhofer, Lukas A1 - Passon, Oliver T1 - Reconsidering the Relation Between “Matter Wave Interference” and “Wave–Particle Duality” JF - Foundations of Physics N2 - Interference of more and more massive objects provides a spectacular confirmation of quantum theory. It is usually regarded as support for “wave–particle duality” and in an extension of this duality even as support for “complementarity”. We first give an outline of the historical development of these notions. Already here it becomes evident that they are hard to define rigorously, i.e. have mainly a heuristic function. Then we discuss recent interference experiments of large and complex molecules which seem to support this heuristic function of “duality”. However, we show that in these experiments the diffraction of a delocalized center-of-mass wave function depends on the interaction of the localized structure of the molecule with the diffraction element. Thus, the molecules display “dual features” at the same time, which contradicts the usual understanding of wave–particle duality. We conclude that the notion of “wave–particle duality” deserves no place in modern quantum physics. KW - Quantenmechanik KW - Welle-Teilchen-Dualismus KW - Interferenz Y1 - IS - 52/32 PB - Springer ER - TY - JOUR A1 - Kuba, Markus T1 - On multisets, interpolated multiple zeta values and limit laws. JF - Electronic Journal of Combinatorics N2 - In this work we discuss a parameter σ on weighted k-element multisets of [n]={1,…,n}. The sums of weighted k-multisets are related to k-subsets, k-multisets, as well as special instances of truncated interpolated multiple zeta values. We study properties of this parameter using symbolic combinatorics. We rederive and extend certain identities for ζtn({m}k). Moreover, we introduce random variables on the k-element multisets and derive their distributions, as well as limit laws for k or n tending to infinity. KW - k-multisets KW - k-subsets KW - truncated-multiple-zeta-values KW - interpolated-multiple-zeta-values KW - harmonic-numbers Y1 - IS - Vol. 29, Issue 1 ER - TY - GEN A1 - Mairhofer, Lukas A1 - Maiwöger, Mira T1 - Entanglement: From Philosophy to Quantum Information - and back Experiments on Bell-inequalties - threat to the Theory of Relativity? KW - Quantenphysik KW - Bell-Ungleichungen KW - Verschränkung Y1 - ER - TY - GEN A1 - Mairhofer, Lukas T1 - From foundational research to application - Training Quantum Engineers KW - Didaktik KW - Quantentechnologien KW - Quantencomputer KW - Quantenkryptographie Y1 - ER -