TY - JOUR A1 - Mandl, Thomas A1 - Meyerspeer, Martin A1 - Reichel, Martin A1 - Kern, Helmut A1 - Hofer, Christian A1 - Mayr, Winfried A1 - Moser, Ewald T1 - Functional electrical stimulation of long-term denervated, degenerated human skeletal muscle: estimating activation using T2-parameter magnetic resonance imaging methods JF - Artif Organs KW - Electrical Stimulation KW - Muscle Stimulation Y1 - 2019 IS - 32(8) SP - 604 EP - 608 ER - TY - JOUR A1 - Lanmüller, Hermann A1 - Ashley, Z. A1 - Unger, E. A1 - Sutherland, H. A1 - Reichel, Martin A1 - Russold, M. A1 - Jarvis, J. A1 - Mayr, Winfried A1 - Salmons, S. T1 - Implantable device for long-term electrical stimulation of denervated muscles in rabbits JF - Med Biol Eng Comput KW - Electrical Stimulation KW - Muscle Stimulation KW - Muscle Denervation Y1 - 2019 VL - 43 IS - 4 SP - 535 EP - 540 ER - TY - JOUR A1 - Pucher, Robert A1 - Holweg, Gerd A1 - Mandl, Thomas A1 - Salzbrunn, Benedikt T1 - Optimizing higher education for the professional student. The example of Computer Science education at the University of Applied Sciences Technikum Wien JF - Digital Universities. International Best Practices and Applications KW - Education KW - Computer Science Y1 - 2018 ER - TY - JOUR A1 - Maleiner, Babette A1 - Tomasch, Janine A1 - Heher, Philipp A1 - Spadiut, Oliver A1 - Rünzler, Dominik A1 - Fuchs, Christiane T1 - The Importance of Biophysical and Biochemical Stimuli in Dynamic Skeletal Muscle Models. JF - Frontiers in Physiology N2 - Classical approaches to engineer skeletal muscle tissue based on current regenerative and surgical procedures still do not meet the desired outcome for patient applications. Besides the evident need to create functional skeletal muscle tissue for the repair of volumetric muscle defects, there is also growing demand for platforms to study muscle-related diseases, such as muscular dystrophies or sarcopenia. Currently, numerous studies exist that have employed a variety of biomaterials, cell types and strategies for maturation of skeletal muscle tissue in 2D and 3D environments. However, researchers are just at the beginning of understanding the impact of different culture settings and their biochemical (growth factors and chemical changes) and biophysical cues (mechanical properties) on myogenesis. With this review we intend to emphasize the need for new in vitro skeletal muscle (disease) models to better recapitulate important structural and functional aspects of muscle development. We highlight the importance of choosing appropriate system components, e.g., cell and biomaterial type, structural and mechanical matrix properties or culture format, and how understanding their interplay will enable researchers to create optimized platforms to investigate myogenesis in healthy and diseased tissue. Thus, we aim to deliver guidelines for experimental designs to allow estimation of the potential influence of the selected skeletal muscle tissue engineering setup on the myogenic outcome prior to their implementation. Moreover, we offer a workflow to facilitate identifying and selecting different analytical tools to demonstrate the successful creation of functional skeletal muscle tissue. Ultimately, a refinement of existing strategies will lead to further progression in understanding important aspects of muscle diseases, muscle aging and muscle regeneration to improve quality of life of patients and enable the establishment of new treatment options. KW - Bioreactor KW - Muscle KW - Biomaterial Y1 - ER - 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 - Schuh, Christina A1 - Heher, Philipp A1 - Weihs, Anna A1 - Fuchs, Christiane A1 - Gabriel, Christian A1 - Wolbank, Susanne A1 - Mittermayr, Rainer A1 - Redl, Heinz A1 - Rünzler, Dominik A1 - Teuschl, Andreas T1 - In vitro extracorporeal shock wave treatment enhances stemness and preserves multipotency of rat and human adipose-derived stem cells JF - Journal of Cytotherapy KW - Shockwave Y1 - ER - TY - JOUR A1 - Unterkofler, Karl A1 - Teschl, Susanne T1 - On the influence of inhaled volatile organic compounds (VOCs) on exhaled VOCs concentrations JF - Proceedings of the 10. Forschungsforum der Österreichischen Fachhochschulen KW - Organic Compounds Y1 - 2018 ER - TY - JOUR A1 - Kubinger, Wilfried A1 - Sommer, Roland T1 - Industrie 4.0 - Auswirkungen von Digitalisierung und Internet auf den Industriestandort JF - e&i Elektrotechnik und Informationstechnik KW - Industry 4.0 KW - Digitalisation KW - Industry Location Y1 - 2018 VL - 133 IS - 7 SP - 330 EP - 333 ER - TY - JOUR A1 - Urbauer, Philipp T1 - The Social Platform: Profiling FHIR to Support Community-Dwelling Older Adults JF - Journal of Medical Systems KW - Elderly People KW - eHealth KW - Residential Care KW - Integrated Care KW - FHIR Y1 - VL - 4 IS - 43 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 - JOUR A1 - Pucher, Robert A1 - Tesar, Michael A1 - Mandl, Thomas A1 - Holweg, Gerd A1 - Schmöllebeck, Fritz T1 - Improving Didactics in Computer Science - The Example of the GEMIS and the QUADRO Projects JF - International Journal of Education and Information Technologies KW - Didactics KW - Computer Science KW - Education Y1 - 2019 VL - 1 IS - 5 ER - TY - JOUR A1 - Pucher, Robert A1 - Lehner, Martin T1 - Project Based Learning in Computer Science JF - Procedia - Social and Behavioral Sciences, Volume 29, 2011, Pages 1561-1566, ISSN 1877-0428, KW - Project Based Learning KW - Computer Science Y1 - 2019 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 - Huber, Albert T1 - The gravitational field of a massless particle on the horizon of a stationary black hole JF - Classical and Quantum Gravity N2 - In this work, the field of a gravitational shockwave generated by a massless point-like particle is calculated at the event horizon of a stationary Kerr–Newman black hole. Using the geometric framework of generalized Kerr–Schild deformations in combination with the spin-coefficient formalism of Newman and Penrose, it is shown that the field equations of the theory, at the event horizon of the black hole, can be reduced to a single linear ordinary differential equation for the so-called profile function of the geometry. This differential relation is solved exactly. Based on the results obtained, a physical interpretation is given for the found shockwave spacetime, and it is clarified how these results lead back to those of previous works on the subject, which deal with the much simpler cases of gravitational shockwaves in static black hole backgrounds. KW - Gravitation Y1 - 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 - JOUR A1 - Hoffmann, Michael E. A1 - Kuba, Markus T1 - Logarithmic integrals, zeta values, and tiered binomial coeffcients JF - Monatshefte fuer Mathematik KW - Integrals KW - Binomial KW - Coefficient Y1 - ER - TY - JOUR A1 - Belkacem, Kévin A1 - Kupka, Friedrich A1 - Philidet, Jordan A1 - Samadi, Réza T1 - Surface effects and turbulent pressure. Assessing the Gas-Γ1 and Reduced-Γ1 empirical models. JF - Astronomy & Astrophysics KW - Surface KW - Pressure Y1 - ER - TY - JOUR A1 - Kialka, Filip A1 - Stickler, Benjamin A1 - Hornberger, Klaus A1 - Fein, Yaakov A1 - Geyer, Philipp A1 - Mairhofer, Lukas A1 - Gerlich, Stefan A1 - Arndt, Markus T1 - Concepts for long-baseline, high-mass matter-wave interferometry JF - Physica Scripta N2 - Designing experiments which delocalize ever more complex and more massive particles requires a quantitative assessment of new interferometer configurations. Here, we introduce a figure of merit which quantifies the difference between a genuine quantum interference pattern and a classical shadow and use it to compare a number of near-field interferometer schemes. This allows us to identify the most promising setups for future tests of the quantum superposition principle, and to discuss the perspectives of interferometry with complex molecules and clusters. KW - Matter wave optics KW - Quantum optics in phase space KW - Meteorology Y1 - IS - 94, 2019 ER - TY - JOUR A1 - Huber, Albert T1 - Junction Conditions and local Spacetimes in General Relativity JF - The European Physical Journal C N2 - In the present work, a theoretical framework focussing on local geometric deformations is introduced in order to cope with the problem of how to join spacetimes with different geometries and physical properties. This framework is used to show that two Lorentzian manifolds can be matched by considering local deformations of the associated spacetime metrics. Based on the fact that metrics can be suitably matched in this way, it is shown that the underlying geometric approach allows the characterization of local spacetimes in general relativity. Furthermore, it is shown that said approach not only extends the conventional thin shell formalism, but also allows the treatment of geometric problems that cannot be treated with standard gluing techniques. KW - Relativity Y1 - ER - TY - JOUR A1 - Schätti, Jonas A1 - Köhler, Valentin A1 - Mayor, Marcel A1 - Fein, Yaakov A1 - Geyer, Philipp A1 - Mairhofer, Lukas A1 - Gerlich, Stefan A1 - Arndt, Markus T1 - Matter-wave interference and deflection of tripeptides decorated with fluorinated alkyl chains JF - Journal of Mass Spectrometry KW - interference KW - quantum KW - meteorology Y1 - IS - Vol 55, issue 6 ER - TY - JOUR A1 - Fein, Yaakov A1 - Shayeghi, Armin A1 - Mairhofer, Lukas A1 - Kialka, Filip A1 - Rieser, Philipp A1 - Geyer, Philipp A1 - Gerlich, Stefan A1 - Arndt, Markus T1 - Quantum-Assisted Measurement of Atomic Diamagnetism JF - Physical Review KW - diamagnetism KW - quantum KW - meteorology Y1 - IS - Volume 10, Issue 1 ER - TY - JOUR A1 - Hoffman, Michael E. A1 - Kuba, Markus A1 - Levy, Moti A1 - Louchard, Guy T1 - An Asymptotic Series for an Integral JF - Ramanujan Journal KW - asymtotic KW - integral Y1 - 2020 ER - TY - JOUR A1 - Hoffmann, Michael E. A1 - Kuba, Markus A1 - Levy, Moti A1 - Louchard, Guy T1 - An Asymptotic Series for an Integral JF - Ramanujan Journal KW - Asymptotic KW - Integral Y1 - ER - TY - JOUR A1 - Kuba, Markus A1 - Panholzer, Alois T1 - A Note on Harmonic number identities, Stirling series and multiple zeta values JF - International Journal of Number Theory KW - Multiple zeta values KW - Harmonic numbers KW - Arakawa–Kaneko zeta function KW - Stirling series Y1 - 2020 VL - 15 IS - 07 SP - 1323 EP - 1348 ER - TY - JOUR A1 - Mairhofer, Lukas A1 - Eibenberger, Sandra A1 - Shayeghi, Armin A1 - Arndt, Markus T1 - A quantum ruler for magnetic deflectometry JF - Entropy KW - Magnetic deflectometry KW - Matter-waves KW - Metrology Y1 - VL - 20 IS - 7 CY - Basel ER - TY - JOUR A1 - Kuba, Markus A1 - Panholzer, Alois T1 - Stirling permutations containing a single pattern of length three JF - The Australasian Journal of Combinatorics KW - Stirling permutations Y1 - 2020 VL - 74 IS - 2 SP - 216 EP - 239 ER - TY - JOUR A1 - Kuba, Markus T1 - A Note on the generating function of p-Bernoulli numbers JF - Quaestiones Mathematicae KW - Mathematics Y1 - ER - TY - JOUR A1 - Teschl, Susanne A1 - Unterkofler, Karl A1 - Mochalski, Pawel A1 - Teschl, Gerald A1 - Ager, C. A1 - Mayhew, C.A. A1 - King, Julian T1 - Modeling-based determination of physiological parameters of systemic VOCs by breath gas analysis, part 2. JF - Journal of Breath Research KW - Breath KW - Gas KW - Analysis Y1 - VL - 12 ER - TY - JOUR A1 - Mairhofer, Lukas A1 - Eibenberger, Sandra A1 - Cotter, Joe A1 - Romirer, Marion A1 - Shayeghi, Armin A1 - Arndt, Markus T1 - Quantum-assisted metrology of neutral vitamins in the gas-phase JF - Angewandte Chemie International Edition N2 - It has recently been shown that matter-wave interferometry can be used to imprint a periodic nanostructure onto a molecular beam, which provides a highly sensitive tool for beam displacement measurements. Herein, we used this feature to measure electronic properties of provitamin A, vitamin E, and vitamin K1 in the gas phase for the first time. The shift of the matter-wave fringes in a static electric field encodes the molecular susceptibility and the time-averaged dynamic electric dipole moment. The dependence of the fringe pattern on the intensity of the central light-wave diffraction grating was used to determine the molecular optical polarizability. Comparison of our experimental findings with molecular dynamics simulations and density functional theory provides a rich picture of the electronic structures and dynamics of these biomolecules in the gas phase with β-carotene as a particularly interesting example. KW - Deflectometry KW - Electronic structure KW - Interferometry Y1 - ER - TY - JOUR A1 - Geyer, Philipp A1 - Sezer, Ugur A1 - Rodewald, Jonas A1 - Mairhofer, Lukas A1 - Dörre, Nadine A1 - Haslinger, Philipp A1 - Eibenberger, Sandra A1 - Brand, Christian A1 - Arndt, Markus T1 - Perspectives for Quantum Interference with Biomolecules and Biomolecular Clusters JF - Physica Scripta KW - Quanteninterferenz KW - Biomoleküle Y1 - VL - 91 IS - 6 ER - TY - JOUR A1 - Kuba, Markus A1 - Sulzbach, Henning T1 - On martingale tail sums in affine two-color urn models with multiple drawings JF - Journal of Applied Probability KW - Probability Calculation Y1 - 2018 VL - 54 IS - 1 SP - 96 EP - 117 ER - TY - JOUR A1 - Cotter, Joe A1 - Eibenberger, Sandra A1 - Mairhofer, Lukas A1 - Cheng, Xiaxi A1 - Asenbaum, Peter A1 - Arndt, Markus A1 - Walter, Kai A1 - Nimmrichter, Stefan A1 - Hornberger, Klaus T1 - Coherence in the presence of absorption and heating in a molecule interferometer JF - Nature Communications KW - Quantenphysik KW - Molekülinterferometer Y1 - IS - 6 ER - TY - JOUR A1 - Unterkofler, Karl A1 - King, Julian A1 - Mochalski, Pawel A1 - Jandacka, Martin A1 - Koc, Helin A1 - Teschl, Susanne A1 - Amann, Anton A1 - Teschl, Gerald T1 - Modeling-based determination of physiological parameters of systemic VOCs by breath gas analysis: a pilot study JF - Journal of Breath Research KW - Breath Gas KW - Analysis Y1 - ER - TY - JOUR A1 - Kuba, Markus A1 - Panholzer, Alois T1 - Combinatorial families of multilabelled increasing trees and hook-length formulas. JF - Discrete Mathematics KW - Mathematical Trees KW - Mathematics Y1 - 2018 ER - TY - JOUR A1 - Kuba, Markus A1 - Panholzer, Alois T1 - On moment sequences and mixed Poisson distributions. JF - Probability Surveys KW - Mathematics KW - Statistical Distributions Y1 - 2018 ER - TY - JOUR A1 - Teschl, Susanne A1 - Batzel, J. A1 - Kappel, F. T1 - Modeling the human cardiovascular-respiratory control system with two state delays: an application to congestive heart failure JF - Technical Report 191, Spezialforschungsbereich F-003 Bericht, Karl-Franzens-Universitat KW - Modeling KW - Cardiovascular Y1 - ER - TY - JOUR A1 - Teschl, Susanne A1 - Batzel, J. A1 - Kappel, F. T1 - Modeling the human cardiovascular-respiratory control system: an optimal control application to the transition to non-REM sleep JF - Technical Report 190, Spezialforschungsbereich F-003, Karl-Franzens-Universität KW - Modeling KW - Cardiovascular KW - Sleep Y1 - ER - TY - JOUR A1 - Purtscher, Michaela A1 - Rothbauer, Mario A1 - Kratz, Sebastian Rudi Adam A1 - Bailey, Andrew A1 - Lieberzeit, Peter A1 - Ertl, Peter T1 - A microfluidic impedance-based extended infectivity assay: combining retroviral amplification and cytopathic effect monitoring on a single lab-on-a-chip platform JF - Lab on a Chip N2 - Detection, quantification and monitoring of virus – host cell interactions are of great importance when evaluating the safety of pharmaceutical products. With the wide usage of viral based vector systems in combination with mammalian cell lines for the production of biopharmaceuticals, the presence of replication competent viral particles needs to be avoided and potential hazards carefully assessed. Consequently, regulatory agencies recommend viral clearance studies using plaque assays or TCID50 assays to evaluate the efficiency of the production process in removing viruses. While plaque assays provide reliable information on the presence of viral contaminations, they are still tedious to perform and can take up to two weeks to finish. To overcome some of these limitations, we have automated, miniaturized and integrated the dual cell culture bioassay into a common lab-on-a-chip platform containing embedded electrical sensor arrays to enrich and detect infectious viruses. Results of our microfluidic single step assay show that a significant reduction in assay time down to 3 to 4 days can be achieved using simultaneous cell-based viral amplification, release and detection of cytopathic effects in a target cell line. We further demonstrate the enhancing effect of continuous fluid flow on infection of PG-4 reporter cells by newly formed and highly active virions by M. dunni cells, thus pointing to the importance of physical relevant viral–cell interactions. KW - Tissue Engineering KW - Microfluidics KW - Lab on Chip Y1 - 2021 VL - 2021 IS - Issue 7 SP - 1364 EP - 1372 ER - TY - JOUR A1 - Zupkovitz, Gordin A1 - Kabiljo, Julijan A1 - Kothmayer, Michael A1 - Schlick, Katharina A1 - Schöfer, Christian A1 - Lagger, Sabine A1 - Pusch, Oliver T1 - Analysis of Methylation Dynamics Reveals a Tissue-Specific, Age-Dependent Decline in 5-Methylcytosine Within the Genome of the Vertebrate Aging Model Nothobranchius furzeri. JF - Frontiers in Molecular Biosciences N2 - Erosion of the epigenetic DNA methylation landscape is a widely recognized hallmark of aging. Emerging advances in high throughput sequencing techniques, in particular DNA methylation data analysis, have resulted in the establishment of precise human and murine age prediction tools. In vertebrates, methylation of cytosine at the C5 position of CpG dinucleotides is executed by DNA methyltransferases (DNMTs) whereas the process of enzymatic demethylation is highly dependent on the activity of the ten-eleven translocation methylcytosine dioxygenase (TET) family of enzymes. Here, we report the identification of the key players constituting the DNA methylation machinery in the short-lived teleost aging model Nothobranchius furzeri. We present a comprehensive spatio-temporal expression profile of the methylation-associated enzymes from embryogenesis into late adulthood, thereby covering the complete killifish life cycle. Data mining of the N. furzeri genome produced five dnmt gene family orthologues corresponding to the mammalian DNMTs (DNMT1, 2, 3A, and 3B). Comparable to other teleost species, N. furzeri harbors multiple genomic copies of the de novo DNA methylation subfamily. A related search for the DNMT1 recruitment factor UHRF1 and TET family members resulted in the identification of N. furzeri uhrf1, tet1, tet2, and tet3. Phylogenetic analysis revealed high cross-species similarity on the amino acid level of all individual dnmts, tets, and uhrf1, emphasizing a high degree of functional conservation. During early killifish development all analyzed dnmts and tets showed a similar expression profile characterized by a strong increase in transcript levels after fertilization, peaking either at embryonic day 6 or at the black eye stage of embryonic development. In adult N. furzeri, DNA methylation regulating enzymes showed a ubiquitous tissue distribution. Specifically, we observed an age-dependent downregulation of dnmts, and to some extent uhrf1, which correlated with a significant decrease in global DNA methylation levels in the aging killifish liver and muscle. The age-dependent DNA methylation profile and spatio-temporal expression characteristics of its enzymatic machinery reported here may serve as an essential platform for the identification of an epigenetic aging clock in the new vertebrate model system N. furzeri. KW - Tissue Engineering KW - Killifish KW - Aging Model Y1 - VL - 8 IS - 627143 ER - TY - JOUR A1 - Deininger, Christian A1 - Wagner, Andrea A1 - Heimel, Patrick A1 - Salzer, Elias A1 - Monforte Vila, Xavier A1 - Weißenbacher, Nadja A1 - Grillari, Johannes A1 - Redl, Heinz A1 - Wichlas, Florian A1 - Freude, Thomas A1 - Tempfer, Herbert A1 - Teuschl-Woller, Andreas A1 - Traweger, Andreas T1 - Enhanced BMP-2-Mediated Bone Repair Using an Anisotropic Silk Fibroin Scaffold Coated with Bone-like Apatite JF - Int. J. Mol. Sci. N2 - The repair of large bone defects remains challenging and often requires graft material due to limited availability of autologous bone. In clinical settings, collagen sponges loaded with excessive amounts of bone morphogenetic protein 2 (rhBMP-2) are occasionally used for the treatment of bone non-unions, increasing the risk of adverse events. Therefore, strategies to reduce rhBMP-2 dosage are desirable. Silk scaffolds show great promise due to their favorable biocompatibility and their utility for various biofabrication methods. For this study, we generated silk scaffolds with axially aligned pores, which were subsequently treated with 10× simulated body fluid (SBF) to generate an apatitic calcium phosphate coating. Using a rat femoral critical sized defect model (CSD) we evaluated if the resulting scaffold allows the reduction of BMP-2 dosage to promote efficient bone repair by providing appropriate guidance cues. Highly porous, anisotropic silk scaffolds were produced, demonstrating good cytocompatibility in vitro and treatment with 10× SBF resulted in efficient surface coating. In vivo, the coated silk scaffolds loaded with a low dose of rhBMP-2 demonstrated significantly improved bone regeneration when compared to the unmineralized scaffold. Overall, our findings show that this simple and cost-efficient technique yields scaffolds that enhance rhBMP-2 mediated bone healing. KW - Tissue Engineering KW - Biomaterials KW - silk scaffold KW - bone regeneration KW - pseudoarthrosis Y1 - VL - 23 IS - 1 / 283 ER - TY - JOUR A1 - Hackethal, Johannes A1 - Dungel, Peter A1 - Teuschl, Andreas Herbert T1 - Frequently Used Strategies to Isolate Extracellular Matrix Proteins from Human Placenta and Adipose Tissue JF - Tissue Engineering Part C: Methods N2 - The natural extracellular matrix (ECM) provides the optimal environment for cells. Many enzymatic or non-enzymatic based strategies to extract ECM proteins from tissues were published over the past years. However, every single isolation strategy reported so far is associated with specific bottlenecks. In this study, frequently used strategies to isolate ECM from human placenta or adipose tissue using Tris-, serum-, or pepsin-based buffers were compared. The resulting ECM proteins were biochemically characterized by analysis of cellular remnants using Hoechst DNA staining, glycosaminoglycan (GAG) content by dimethylmethylene blue, visualization of protein bands using sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis combined with amino acid quantification, and assessment of the proangiogenic profile using an angiogenesis array. Tris-NaCl-extracted ECM proteins showed a high heterogenic degree of extracted proteins, bioactive growth factors, and GAGs, but no collagen-I. Active serum-extracted ECM showed significant lower DNA remnants when compared with the Tris-NaCl isolation strategy. Pepsin-extracted ECM was rich in collagen-I and low amounts of remaining bioactive growth factors. This strategy was most effective to reduce DNA amounts when compared with the other isolation strategies. Pepsin-extracted ECM from both tissues easily gelled at 37°C, whereas the other extracted ECM strategies did not gel at 37°C (Tris-NaCl: liquid; serum: sponge). All relevant characteristics (DNA residues, ECM diversity and bioactivity, shape) of the extracted ECM proteins highly depend on its isolation strategy and could still be optimized. Impact statement The natural human extracellular matrix (ECM) is the ideal cell niche. Various strategies were reported to isolate human ECM components from various sources. In this article, we compared frequently used methods and compared their characteristics (DNA remnants, glycosaminoglycan content, sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, amino acid quantification, angiogenesis array, and gel formation). We conclude that more research is still necessary to optimize current isolation approaches for in vitro or in vivo applications of human ECM. KW - Tissue Engineering KW - Biomaterials KW - Adipose Tissue KW - extracellular matrix KW - human placenta Y1 - VL - 27 IS - 12 SP - 649 EP - 660 ER - TY - JOUR A1 - Khimich, Margarita A. A1 - Prosolov, Konstantin A. A1 - Mishurova, Tatiana A1 - Evsevleev, Sergej A1 - Monforte, Xavier A1 - Teuschl, Andreas H. A1 - Slezak, Paul A1 - Ibragimov, Egor A. A1 - Saprykin, Alexander A. A1 - Kovalevskaya, Zhanna G. A1 - Dmitriev, Andrey I. A1 - Bruno, Giovanni A1 - Sharkeev, Yurii P. T1 - Advances in Laser Additive Manufacturing of Ti-Nb Alloys: From Nanostructured Powders to Bulk Objects JF - Nanomaterials (Basel) N2 - The additive manufacturing of low elastic modulus alloys that have a certain level of porosity for biomedical needs is a growing area of research. Here, we show the results of manufacturing of porous and dense samples by a laser powder bed fusion (LPBF) of Ti-Nb alloy, using two distinctive fusion strategies. The nanostructured Ti-Nb alloy powders were produced by mechanical alloying and have a nanostructured state with nanosized grains up to 90 nm. The manufactured porous samples have pronounced open porosity and advanced roughness, contrary to dense samples with a relatively smooth surface profile. The structure of both types of samples after LPBF is formed by uniaxial grains having micro- and nanosized features. The inner structure of the porous samples is comprised of an open interconnected system of pores. The volume fraction of isolated porosity is 2 vol. % and the total porosity is 20 vol. %. Cell viability was assessed in vitro for 3 and 7 days using the MG63 cell line. With longer culture periods, cells showed an increased cell density over the entire surface of a porous Ti-Nb sample. Both types of samples are not cytotoxic and could be used for further in vivo studies. KW - Tissue Engineering KW - Biomaterials KW - Laser Additive Manufacturing KW - Bulk Objects Y1 - VL - 11 IS - 5 / 1159 ER - TY - JOUR A1 - Farokhi, Maryam A1 - Aleemardani, Mina A1 - Solouk, Atefeh A1 - Mirzadeh, Hamid A1 - Teuschl, Andreas Herbert A1 - Redl, Heinz T1 - Crosslinking strategies for silk fibroin hydrogels: promising biomedical materials JF - Biomedical Materials N2 - Due to their strong biomimetic potential, silk fibroin (SF) hydrogels are impressive candidates for tissue engineering, due to their tunable mechanical properties, biocompatibility, low immunotoxicity, controllable biodegradability, and a remarkable capacity for biomaterial modification and the realization of a specific molecular structure. The fundamental chemical and physical structure of SF allows its structure to be altered using various crosslinking strategies. The established crosslinking methods enable the formation of three-dimensional (3D) networks under physiological conditions. There are different chemical and physical crosslinking mechanisms available for the generation of SF hydrogels (SFHs). These methods, either chemical or physical, change the structure of SF and improve its mechanical stability, although each method has its advantages and disadvantages. While chemical crosslinking agents guarantee the mechanical strength of SFH through the generation of covalent bonds, they could cause some toxicity, and their usage is not compatible with a cell-friendly technology. On the other hand, physical crosslinking approaches have been implemented in the absence of chemical solvents by the induction of β-sheet conformation in the SF structure. Unfortunately, it is not easy to control the shape and properties of SFHs when using this method. The current review discusses the different crosslinking mechanisms of SFH in detail, in order to support the development of engineered SFHs for biomedical applications. KW - Tissue Engineering KW - hydrogels KW - Biomaterials KW - silk fibroin Y1 - VL - 16 IS - 2 SP - 022004 ER - TY - JOUR A1 - Schanda, Jakob A1 - Keibl, Claudia A1 - Heimel, Patrick A1 - Monforte, Xavier A1 - Feichtinger, Xaver A1 - Teuschl, Andreas A1 - Baierl, Andreas A1 - Muschitz, Christian A1 - Redl, Heinz A1 - Fialka, Christian A1 - Mittermayr, Rainer T1 - Zoledronic Acid Substantially Improves Bone Microarchitecture and Biomechanical Properties After Rotator Cuff Repair in a Rodent Chronic Defect Model JF - Am J Sports Med N2 - Background: Bone mineral density at the humeral head is reduced in patients with chronic rotator cuff tears. Bone loss in the humeral head is associated with repair failure after rotator cuff reconstruction. Bisphosphonates (eg, zoledronic acid) increase bone mineral density. Hypothesis: Zoledronic acid improves bone mineral density of the humeral head and biomechanical properties of the enthesis after reconstruction of chronic rotator cuff tears in rats. Study design: Controlled laboratory study. Methods: A total of 32 male Sprague-Dawley rats underwent unilateral (left) supraspinatus tenotomy with delayed transosseous rotator cuff reconstruction after 3 weeks. All rats were sacrificed 8 weeks after rotator cuff repair. Animals were randomly assigned to 1 of 2 groups. At 1 day after rotator cuff reconstruction, the intervention group was treated with a single subcutaneous dose of zoledronic acid at 100 µg/kg bodyweight, and the control group received 1 mL of subcutaneous saline solution. In 12 animals of each group, micro-computed tomography scans of both shoulders were performed as well as biomechanical testing of the supraspinatus enthesis of both sides. In 4 animals of each group, histological analyses were conducted. Results: In the intervention group, bone volume fraction (bone volume/total volume [BV/TV]) of the operated side was higher at the lateral humeral head (P = .005) and the medial humeral head (P = .010) compared with the control group. Trabecular number on the operated side was higher at the lateral humeral head (P = .004) and the medial humeral head (P = .001) in the intervention group. Maximum load to failure rates on the operated side were higher in the intervention group (P < .001). Cortical thickness positively correlated with higher maximum load to failure rates in the intervention group (r = 0.69; P = .026). Histological assessment revealed increased bone formation in the intervention group. Conclusion: Single-dose therapy of zoledronic acid provided an improvement of bone microarchitecture at the humeral head as well as an increase of maximum load to failure rates after transosseous reconstruction of chronic rotator cuff lesions in rats. Clinical relevance: Zoledronic acid improves bone microarchitecture as well as biomechanical properties after reconstruction of chronic rotator cuff tears in rodents. These results need to be verified in clinical investigations. KW - Tissue Engineering KW - Rotator Cuff Tears Y1 - VL - 2020 Jul IS - 48 (9) SP - 2151 EP - 2160 ER - TY - JOUR A1 - Bachmann, Barbara A1 - Spitz, Sarah A1 - Schädl, Barbara A1 - Teuschl, Andreas A1 - Redl, Heinz A1 - Nürnberger, Sylvia A1 - Ertl, Peter T1 - Stiffness Matters: Fine-Tuned Hydrogel Elasticity Alters Chondrogenic Redifferentiation JF - Froniers in Bioengineering and Biotechnology N2 - Biomechanical cues such as shear stress, stretching, compression, and matrix elasticity are vital in the establishment of next generation physiological in vitro tissue models. Matrix elasticity, for instance, is known to guide stem cell differentiation, influence healing processes and modulate extracellular matrix (ECM) deposition needed for tissue development and maintenance. To better understand the biomechanical effect of matrix elasticity on the formation of articular cartilage analogs in vitro, this study aims at assessing the redifferentiation capacity of primary human chondrocytes in three different hydrogel matrices of predefined matrix elasticities. The hydrogel elasticities were chosen to represent a broad spectrum of tissue stiffness ranging from very soft tissues with a Young's modulus of 1 kPa up to elasticities of 30 kPa, representative of the perichondral-space. In addition, the interplay of matrix elasticity and transforming growth factor beta-3 (TGF-β3) on the redifferentiation of primary human articular chondrocytes was studied by analyzing both qualitative (viability, morphology, histology) and quantitative (RT-qPCR, sGAG, DNA) parameters, crucial to the chondrotypic phenotype. Results show that fibrin hydrogels of 30 kPa Young's modulus best guide chondrocyte redifferentiation resulting in a native-like morphology as well as induces the synthesis of physiologic ECM constituents such as glycosaminoglycans (sGAG) and collagen type II. This comprehensive study sheds light onto the mechanobiological impact of matrix elasticity on formation and maintenance of articular cartilage and thus represents a major step toward meeting the need for advanced in vitro tissue models to study both re- and degeneration of articular cartilage. KW - Tissue Engineering KW - Chondrogenic Redifferentiation KW - Biomaterials Y1 - 2021 VL - 2020 IS - 8 SP - 373 ER - TY - JOUR A1 - Simböck, Elisabeth A1 - Marksteiner, Jessica A1 - Machacek, Thomas A1 - Wiessner, Katharina A1 - Gepp, Barbara A1 - Jesenberger, Veronika A1 - Weihs, Anna A1 - Leitner, Rita T1 - The Power of Problem Based Learning beyond its Didactic Attributes JF - Journal of Problem Based Learning in Higher Education (JPBLHE) N2 - Hybrid courses with a focus on practice-orientated education and self-guided learning phases are on the rise on the higher education sector. Disciplines in Life Sciences implicate a high degree of practical laboratory expertise. The University of Applied Sciences (UAS) in Vienna, Austria, has thus been endeavoured offering students a high qualitative education integrating hybrid courses based on PBL principles, which consist of on-site (including the transmission of necessary background and practical laboratory training) and off-site (including self-study phases) sessions. As practical laboratory units are central in those courses, the restrictive measures, including the transition to a complete online teaching format due to the first Covid-19-pandemic lock-down, had severe effects on the implementation and the quality of the curriculum. According to surveys made specifically to address this problematic situation, it can be concluded that on-site practical units are fundamental for certain disciplines such as Life Sciences. KW - Problem-based Learning KW - Life Science didactics KW - Hybrid PBL-methods KW - COVID-19 KW - Life Science Education Y1 - VL - 9 IS - 1 SP - 109 EP - 130 ER - TY - JOUR A1 - Ziadlou, Reihane A1 - Rotman, Stijn A1 - Teuschl, Andreas A1 - Salzer, Elias A1 - Barbero, Andrea A1 - Martin, Ivan A1 - Alini, Mauro A1 - Eglin, David A1 - Grad, Sibylle T1 - Optimization of hyaluronic acid-tyramine/silk-fibroin composite hydrogels for cartilage tissue engineering and delivery of anti-inflammatory and anabolic drugs JF - Materials Science and Engineering: C N2 - Injury of articular cartilage leads to an imbalance in tissue homeostasis, and due to the poor self-healing capacity of cartilage the affected tissue often exhibits osteoarthritic changes. In recent years, injectable and highly tunable composite hydrogels for cartilage tissue engineering and drug delivery have been introduced as a desirable alternative to invasive treatments. In this study, we aimed to formulate injectable hydrogels for drug delivery and cartilage tissue engineering by combining different concentrations of hyaluronic acid-tyramine (HA-Tyr) with regenerated silk-fibroin (SF) solutions. Upon enzymatic crosslinking, the gelation and mechanical properties were characterized over time. To evaluate the effect of the hydrogel compositions and properties on extracellular matrix (ECM) deposition, bovine chondrocytes were embedded in enzymatically crosslinked HA-Tyr/SF composites (in further work abbreviated as HA/SF) or HA-Tyr hydrogels. We demonstrated that all hydrogel formulations were cytocompatible and could promote the expression of cartilage matrix proteins allowing chondrocytes to produce ECM, while the most prominent chondrogenic effects were observed in hydrogels with HA20/SF80 polymeric ratios. Unconfined mechanical testing showed that the compressive modulus for HA20/SF80 chondrocyte-laden constructs was increased almost 10-fold over 28 days of culture in chondrogenic medium which confirmed the superior production of ECM in this hydrogel compared to other hydrogels in this study. Furthermore, in hydrogels loaded with anabolic and anti-inflammatory drugs, HA20/SF80 hydrogel showed the longest and the most sustained release profile over time which is desirable for the long treatment duration typically necessary for osteoarthritic joints. In conclusion, HA20/SF80 hydrogel was successfully established as a suitable injectable biomaterial for cartilage tissue engineering and drug delivery applications. KW - Tissue Engineering KW - Cartilage KW - Mechanical Testing KW - Biomaterials KW - Chondrocytes Y1 - VL - 120 IS - 111701 ER -