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DNA Sequencing (2011)

Zwacka, R. ; Mohr, A. ; Herr, I. ; Weiher, H.

Biomaterials and mesenchymal stem cells for regenerative medicine (2010)

Zippel, Nina ; Schulze, Margit ; Tobiasch, Edda

Transient up-regulation of P2 receptors influence differentiation of human mesenchymal stem cells (2012)

Zippel, Nina ; Limbach, Christian ; Pansky, Andreas ; Tobiasch, Edda

Purinergic Receptors Influence the Differentiation of Human Mesenchymal Stem Cells (2012)

Zippel, Nina ; Limbach, Christian Andreas ; Ratajski, Nadine ; Urban, Christian ; Luparello, Claudio ; Pansky, Andreas ; Kassack, Matthias Ullrich ; Tobiasch, Edda

Adult stem cells, including adipose tissue-derived mesenchymal stem cells (MSCs) or ectomesenchymal dental follicle cells (DFCs), attract considerable attention for their potential to differentiate into lineages, which are of major interest in the field of Regenerative Medicine. Purinergic receptors exert a wide range of biological actions in many cell and tissue types through extracellular nucleotides. Little is known about P2 receptors in adult stem cells and changes in their expression levels during differentiation. All known P2 receptors have been investigated, and a variety of P2X and P2Y receptor subtypes were detected in MSCs. Studies investigating intracellular calcium levels on receptor stimulation demonstrated that the found P2 receptors are metabolically active. Interestingly, up- or downregulation of several P2 receptor subtypes at gene and protein level was observed during adipogenic and osteogenic differentiation, and the effect on differentiation was directly influenced by both the application of agonists/antagonists and apyrase-induced nucleotide cleavage. Here, we show for the first time that the combination of several P2 receptors plays a role in the differentiation of adult stem cells. The expression pattern of the P2 receptors, as well as their fate in differentiation, varies in stem cells of mesenchymal origin if compared with stem cells of ectomesenchymal origin. The subtypes P2X6, P2Y4, and P2Y14 seem to be pivotal regulators in MSC commitment, as they are regulated in both adipogenic and osteogenic differentiation of adipose tissue-derived stem cells and DFCs. These findings provide new insights into the differentiation processes and might reveal novel options to influence stem cell fate in future applications.

The influence of simulated microgravity on purinergic signaling is different between individual culture and endothelial and smooth muscle cell coculture (2014)

Zhang, Yu ; Lau, Patrick ; Pansky, Andreas ; Kassack, Matthias ; Hemmersbach, Ruth ; Tobiasch, Edda

Exposure to microgravity conditions causes cardiovascular deconditioning in astronauts during spaceflight. Until now, no specific drugs are available for countermeasure, since the underlying mechanism is largely unknown. Endothelial cells (ECs) and smooth muscle cells (SMCs) play key roles in various vascular functions, many of which are regulated by purinergic 2 (P2) receptors. However, their function in ECs and SMCs under microgravity conditions is still unclear. In this study, primary ECs and SMCs were isolated from bovine aorta and verified with specific markers. We show for the first time that the P2 receptor expression pattern is altered in ECs and SMCs after 24 h exposure to simulated microgravity using a clinostat. However, conditioned medium compensates this change in specific P2 receptors, for example, P2X7. Notably, P2 receptors such as P2X7 might be the important players during the paracrine interaction. Additionally, ECs and SMCs secreted different cytokines under simulated microgravity, leading into a pathogenic proliferation and migration. In conclusion, our data indicate P2 receptors might be important players responding to gravity changes in ECs and SMCs. Since some artificial P2 receptor ligands are applied as drugs, it is reasonable to assume that they might be promising candidates against cardiovascular deconditioning in the future.

Mechanisms Underlying the Osteo-and Adipo-Differentiation of Human Mesenchymal Stem Cells (2012)

Zhang, Yu ; Khan, Dilaware ; Delling, Julia ; Tobiasch, Edda

Human mesenchymal stem cells (hMSCs) are considered a promising cell source for regenerative medicine, because they have the potential to differentiate into a variety of lineages among which the mesoderm-derived lineages such adipo- or osteogenesis are investigated best. Human MSCs can be harvested in reasonable to large amounts from several parts of the patient’s body and due to this possible autologous origin, allorecognition can be avoided. In addition, even in allogenic origin-derived donor cells, hMSCs generate a local immunosuppressive microenvironment, causing only a weak immune reaction. There is an increasing need for bone replacement in patients from all ages, due to a variety of reasons such as a new recreational behavior in young adults or age-related diseases. Adipogenic differentiation is another interesting lineage, because fat tissue is considered to be a major factor triggering atherosclerosis that ultimately leads to cardiovascular diseases, the main cause of death in industrialized countries. However, understanding the differentiation process in detail is obligatory to achieve a tight control of the process for future clinical applications to avoid undesired side effects. In this review, the current findings for adipo- and osteo-differentiation are summarized together with a brief statement on first clinical trials.

Purinergic signalling in mesenchymal stem cell proliferation and differentiation (2014)

Zhang, Yu ; Kaebisch, Constanze ; Schipper, Dorothee ; Babczyk, Patrick ; Gueneri, Dilek ; Tobiasch, Edda

P2 Receptors Influence hMSCs Differentiation towards Endothelial Cell and Smooth Muscle Cell Lineages (2020)

Zhang, Yu ; Babczyk, Patrick ; Pansky, Andreas ; Kassack, Matthias Ulrich ; Tobiasch, Edda

Background: Human mesenchymal stem cells (hMSCs) have shown their multipotential including differentiating towards endothelial and smooth muscle cell lineages, which triggers a new interest for using hMSCs as a putative source for cardiovascular regenerative medicine. Our recent publication has shown for the first time that purinergic 2 receptors are key players during hMSC differentiation towards adipocytes and osteoblasts. Purinergic 2 receptors play an important role in cardiovascular function when they bind to extracellular nucleotides. In this study, the possible functional role of purinergic 2 receptors during MSC endothelial and smooth muscle differentiation was investigated. Methods and Results: Human MSCs were isolated from liposuction materials. Then, endothelial and smooth muscle-like cells were differentiated and characterized by specific markers via Reverse Transcriptase-PCR (RT-PCR), Western blot and immunochemical stainings. Interestingly, some purinergic 2 receptor subtypes were found to be differently regulated during these specific lineage commitments: P2Y4 and P2Y14 were involved in the early stage commitment while P2Y1 was the key player in controlling MSC differentiation towards either endothelial or smooth muscle cells. The administration of natural and artificial purinergic 2 receptor agonists and antagonists had a direct influence on these differentiations. Moreover, a feedback loop via exogenous extracellular nucleotides on these particular differentiations was shown by apyrase digest. Conclusions: Purinergic 2 receptors play a crucial role during the differentiation towards endothelial and smooth muscle cell lineages. Some highly selective and potent artificial purinergic 2 ligands can control hMSC differentiation, which might improve the use of adult stem cells in cardiovascular tissue engineering in the future.

Establishment of a Blood Vessel Cell Culture Model, Testing its Applicability in Microgravity and Drug Research and Examination of the Underlying Signaling Pathways (2014)

Zhang, Yu

During space missions astronauts suffer from cardiovascular deconditioning, when they are exposed to microgravity conditions. Until now, no specific drugs are available for effective countermeasures, since the underlying mechanism is not completely understood. Endothelial cells (ECs) and smooth muscle cells (SMCs) play crucial roles in a variety of cardiovascular functions, many of which are regulated via P2 receptors. However, their function in ECs and SMCs under microgravity condition is still unknown. In this study, ECs and SMCs were isolated from bovine aorta and differentiated from human mesenchymal stem cells (hMSCs), respectively. Subsequently, the cells were verified based on specific markers. An altered P2 receptor expression pattern was detected during the commitment of hMSC towards ECs and SMCs. The administration of natural and artificial P2 receptor agonists and antagonists directly affected the differentiation process. By using EC growth medium as conditioned medium, a vessel cell model was created to culture SMCs and vice versa. Within this study, we were able to show for the first time that the expression of some P2 receptors were altered in ECs and SMCs grown for 24h under simulated microgravity conditions. On the other hand, in some P2 receptor expressions such as P2X7 conditioned medium compensated this change. In conclusion, our data show that P2 receptors play an important functional role in hMSC differentiation towards ECs and SMCs. Since some P2 receptor artificial ligands are already used as drugs for patients with cardiovascular diseases, it is reasonable to assume that in the future they might be promising candidates for treating cardiovascular deconditioning.

p53 acts as a major regulator in human mesenchymal stem cell differentiation towards various cell lineages (2013)

Zhang, Y. ; John, T. ; Liu, K. ; Pansky, A. ; Tobiasch, E.

Effects of Heavy Ion Particle Irradiation on Spore Germination of Bacillus spp. from Extremely Hot and Cold Environments (2020)

Zammuto, Vincenzo ; Rizzo, Maria G. ; Plano, Laura M. de ; Franco, Domenico ; Guglielmino, Salvatore ; Caccamo, Maria T. ; Magazù, Salvatore ; Fujimori, Akira ; Lo Giudice, Angelina ; Guglielmin, Mauro ; McAlpin, Kevin Roderick ; Moeller, Ralf ; Gugliandolo, Concetta

Extremophiles are optimal models in experimentally addressing questions about the effects of cosmic radiation on biological systems. The resistance to high charge energy (HZE) particles, and helium (He) ions and iron (Fe) ions (LET at 2.2 and 200 keV/µm, respectively, until 1000 Gy), of spores from two thermophiles, Bacillushorneckiae SBP3 and Bacilluslicheniformis T14, and two psychrotolerants, Bacillus sp. A34 and A43, was investigated. Spores survived He irradiation better, whereas they were more sensitive to Fe irradiation (until 500 Gy), with spores from thermophiles being more resistant to irradiations than psychrotolerants. The survived spores showed different germination kinetics, depending on the type/dose of irradiation and the germinant used. After exposure to He 1000 Gy, D-glucose increased the lag time of thermophilic spores and induced germination of psychrotolerants, whereas L-alanine and L-valine increased the germination efficiency, except alanine for A43. FTIR spectra showed important modifications to the structural components of spores after Fe irradiation at 250 Gy, which could explain the block in spore germination, whereas minor changes were observed after He radiation that could be related to the increased permeability of the inner membranes and alterations of receptor complex structures. Our results give new insights on HZE resistance of extremophiles that are useful in different contexts, including astrobiology.

Induction of Autophagy: Role of Endoplasmic Reticulum Stress and Unfolded Protein Response (2015)

Yeganeh, Behzad ; Jäger, Richard ; Gorman, Adrienne M. ; Samali, Afshin ; Ghavami, Saeid

Apparent activation energies of protein–protein complex dissociation in the gas–phase determined by electrospray mass spectrometry (2017)

Yefremova, Yelena ; Melder, F. Teresa I. ; Danquah, Bright D. ; Opuni, Kwabena F. M. ; Koy, Cornelia ; Ehrens, Alexandra ; Frommholz, David ; Illges, Harald ; Koelbel, Knut ; Sobott, Frank ; Glocker, Michael O.

Determination of sinapine in rapeseed pomace extract: Its antioxidant and acetylcholinesterase inhibition properties (2019)

Yates, Kyari ; Pohl, Franziska ; Busch, Maike ; Mozer, Annika ; Watters, Louis ; Shiryaev, Andrey ; Kong Thoo Lin, Paul

Non-Cytotoxic Agarose/Hydroxyapatite Composite Scaffolds for Drug Release (2019)

Witzler, Markus ; Ottensmeyer, Patrick Frank ; Gericke, Martin ; Heinze, Thomas ; Tobiasch, Edda ; Schulze, Margit

Healing of large bone defects requires implants or scaffolds that provide structural guidance for cell growth, differentiation, and vascularization. In the present work, an agarose-hydroxyapatite composite scaffold was developed that acts not only as a 3D matrix, but also as a release system. Hydroxyapatite (HA) was incorporated into the agarose gels in situ in various ratios by a simple procedure consisting of precipitation, cooling, washing, and drying. The resulting gels were characterized regarding composition, porosity, mechanical properties, and biocompatibility. A pure phase of carbonated HA was identified in the scaffolds, which had pore sizes of up to several hundred micrometers. Mechanical testing revealed elastic moduli of up to 2.8 MPa for lyophilized composites. MTT testing on Lw35human mesenchymal stem cells (hMSCs) and osteosarcoma MG-63 cells proved the biocompatibility of the scaffolds. Furthermore, scaffolds were loaded with model drug compounds for guided hMSC differentiation. Different release kinetic models were evaluated for adenosine 5′-triphosphate (ATP) and suramin, and data showed a sustained release behavior over four days.

Single-Particle-ICP-MS Nanoparticle Analysis in Fruit Juices (2016)

Witzler, Markus ; Hirtz, Annika ; Kuellmer, Fabian ; Guenther, Klaus

Novel hybrid agarose hydrogels for bone tissue engineering and drug delivery (2017)

Witzler, Markus ; Gericke, Martin ; Heinze, Thomas ; Ottensmeyer, Patrick ; Tobiasch, Edda ; Schulze, Margit

Recent approaches in scaffold engineering for bone defects feature hybrid hydrogels made of a polymeric network (retains water and provides light and porous structures) and inorganic ceramics (add mechanical strength and improve cell-adhesion). Innovative scaffold materials should also induce bone tissue formation and incorporation of stem cells (osteogenic differentiation) and/or growth factors (inducing/supporting differentiation). Recently, purinergic P2X and P2Y receptors have been found to significantly influence the osteogenic differentiation process of human mesenchymal stem cells (hMSC). (1) Aim of this work is to develop polysaccharide (PS) composites to be used as scaffolds containing complementary receptor ligands to enable guided stem cell differentiation towards bone formation.

Polysaccharide-Based Systems for Targeted Stem Cell Differentiation and Bone Regeneration (2019)

Witzler, Markus ; Büchner, Dominik ; Shoushrah, Sarah Hani ; Babczyk, Patrick ; Baranova, Juliana ; Witzleben, Steffen ; Tobiasch, Edda ; Schulze, Margit

Bone tissue engineering is an ever-changing, rapidly evolving, and highly interdisciplinary field of study, where scientists try to mimic natural bone structure as closely as possible in order to facilitate bone healing. New insights from cell biology, specifically from mesenchymal stem cell differentiation and signaling, lead to new approaches in bone regeneration. Novel scaffold and drug release materials based on polysaccharides gain increasing attention due to their wide availability and good biocompatibility to be used as hydrogels and/or hybrid components for drug release and tissue engineering. This article reviews the current state of the art, recent developments, and future perspectives in polysaccharide-based systems used for bone regeneration.

Lignin-Derived Biomaterials for Drug Release and Tissue Engineering (2018)

Witzler, Markus ; Alzagameem, Abla ; Bergs, Michel ; El Khaldi-Hansen, Basma ; Klein, Stephanie E. ; Hielscher, Dorothee ; Kamm, Birgit ; Kreyenschmidt, Judith ; Tobiasch, Edda ; Schulze, Margit

Renewable resources are gaining increasing interest as a source for environmentally benign biomaterials, such as drug encapsulation/release compounds, and scaffolds for tissue engineering in regenerative medicine. Being the second largest naturally abundant polymer, the interest in lignin valorization for biomedical utilization is rapidly growing. Depending on its resource and isolation procedure, lignin shows specific antioxidant and antimicrobial activity. Today, efforts in research and industry are directed toward lignin utilization as a renewable macromolecular building block for the preparation of polymeric drug encapsulation and scaffold materials. Within the last five years, remarkable progress has been made in isolation, functionalization and modification of lignin and lignin-derived compounds. However, the literature so far mainly focuses lignin-derived fuels, lubricants and resins. The purpose of this review is to summarize the current state of the art and to highlight the most important results in the field of lignin-based materials for potential use in biomedicine (reported in 2014⁻2018). Special focus is placed on lignin-derived nanomaterials for drug encapsulation and release as well as lignin hybrid materials used as scaffolds for guided bone regeneration in stem cell-based therapies.

Quantification of Cement Phases and Cement Replacement Materials by Rietveld Refinement Starting from Hydrated Cement Phases in Non-Ambient Conditions (2018)

Witzleben, Steffen ; Walbrück, Katharina ; Mundo, Federico

Investigation of Temperature Dependency of Morphological Properties of Thermoplastic Polyurethane using WAXS and SAXS Monitoring (2015)

Witzleben, Steffen Thomas ; Walbrueck, Katharina ; Klein, Stephanie Elisabeth ; Schulze, Margit

Polyether and polyether/ester based TPU (thermoplastic polyurethanes) were investigated with wide-angle XRD (X-ray diffraction) and SAXS (small angle X-ray scattering). Furthermore, SAXS measurements were performed in the temperature range of 30 °C to 130 °C. Polyether based polymers exhibit only one broad diffraction signal in a region of 2 θ 15° to 25°. In case of polyurethanes with ether/ester modification, the broad diffraction signal arises with small sharp diffraction signals. SAXS measurements of polymers reveal the size and shape of the crystalline zones of the polymer. Between 30 °C and 130 °C the size of the crystalline zone changes significantly. The size decreases in most of investigated TPU. In the case of Desmopan 9365D an increase of the particle size was observed.

Temperature Dependency of Morphological Structure of Thermoplastic Polyurethane using WAXS and SAXS (2016)

Witzleben, Steffen Thomas ; Walbrueck, Katharina

Polyurethanes achieved an exceptional position among the most important organic polymers due to their highly specific technological application areas. Polyurethanes represent a polyaddition product of isocyanate and diols. In terms of their enormous industrial importance, the chemistry of isocyanates has been extensively studied.

Influence of Amino Acids on the Crystallization of Calcium Silicates Hydrates (2017)

Witzleben, Steffen Thomas ; Leiendecker, Alexander ; Wenzel, Michael

Acceleration of Portland cement with lithium, sodium and potassium silicates and hydroxides (2020)

Witzleben, Steffen Thomas

Schlussbericht zu FH Invest-Projekt [my]-Focus XRD 2D (2016)

Witzleben, Steffen

Möglichkeiten und Grenzen der Baustoffanalytik und anwendungstechnische Prüfungen an Objekten (2018)

Witzleben, Steffen

Feldemissions-Elektronenmiskroskop mit Computertomographie-System für Materialentwicklungen und Sicherheitstechnologien FE-SEM-[my]CT : Schlussbericht zu FH Invest-Projekt (2019)

Witzleben, Steffen

Investigations into the influence of chemical activators and templates on cement hydration (2019)

Witzleben, Steffen

Untersuchungen zum Einfluss von chemischen Aktivatoren und Templaten auf die Zementhydratation (2018)

Witzleben, S. T. ; Leiendecker, A. ; Thelen, M.

Galectin‑3 promotes the adhesion, but not the migration of thyroid carcinoma cells in a β‑galactoside‑specific manner (2021)

Winter, Jochen ; Glassmann, Alexander ; Kraus, Dominik ; Frede, Stilla ; Veit, Nadine ; Probstmeier, Rainer

In thyroid carcinoma cells, the soluble βgalactosidespecific lectin, galectin3, is extra and intracellularly expressed and plays a significant role in thyroid cancer diagnosis. The functional relevance of this molecule, particularly in its extracellular environment however, warrants further elucidation. To gain insight into this topic, the present study characterized principal functional properties of galectin3 in 3 commonly used thyroid carcinoma cell lines (BCPAP, Cal62 and FTC133) that express the molecule intra and extracellulary. Cellintrinsic galectin3 harbors a functional carbohydrate recognition domain as determined by affinity purification. Moreover, cell surface expressed galectin3 can be partially removed by treatment with lactose or asialofetuin, but not with sucrose. Thyroid carcinoma cells adhere to substratebound galectin3 in a βgalactosidespecific manner, whereby only cell adhesion, but not cell migration is promoted. Thus, thyroid tumor cells harbor functional active galectin3 that, inter alia, specifically interacts with cell surfaceexpressed molecular ligands in a βgalactosidedependent manner, whereby the molecule can at least interfere with cell adhesion. The modulation of galectin3 expression level or its ligands in such tumor cells could be of therapeutic interest and needs further experimental clarification.

Apple Replant Disease: Causes and Mitigation Strategies (2018)

Winkelmann, Traud ; Smalla, Kornelia ; Amelung, Wulf ; Baab, Gerhard ; Grunewaldt-Stöcker, Gisela ; Kanfra, Xorla ; Meyhöfer, Rainer ; Reim, Stefanie ; Schmitz, Michaela ; Vetterlein, Doris ; Wrede, Andreas ; Zühlke, Sebastian ; Grunewaldt, Jürgen ; Weiß, Stefan ; Schloter, Michael

After replanting apple (Malus domestica Borkh.) on the same site severe growth suppressions, and a decline in yield and fruit quality are observed in all apple producing areas worldwide. The causes of this complex phenomenon, called apple replant disease (ARD), are only poorly understood up to now which is in part due to inconsistencies in terms and methodologies. Therefore we suggest the following definition for ARD: ARD describes a harmfully disturbed physiological and morphological reaction of apple plants to soils that faced alterations in their (micro-) biome due to the previous apple cultures. The underlying interactions likely have multiple causes that extend beyond common analytical tools in microbial ecology. They are influenced by soil properties, faunal vectors, and trophic cascades, with genotype-specific effects on plant secondary metabolism, particularly phytoalexin biosynthesis. Yet, emerging tools allow to unravel the soil and rhizosphere (micro-) biome, to characterize alterations of habitat quality, and to decipher the plant reactions. Thereby, deep insights into the reactions taking place at the root rhizosphere interface will be gained. Counteractions are suggested, taking into account that culture management should emphasize on improving soil microbial and faunal diversity as well as habitat quality rather than focus on soil disinfection.

Application of camelid heavy-chain variable domains (VHHs) in prevention and treatment of bacterial and viral infections (2018)

Wilken, Lucas ; McPherson, Anne

Camelid heavy-chain variable domains (VHHs) are the smallest, intact, antigen-binding units to occur in nature. VHHs possess high degrees of solubility and robustness enabling generation of multivalent constructs with increased avidity - characteristics that mark their superiority to other antibody fragments and monoclonal antibodies. Capable of effectively binding to molecular targets inaccessible to classical immunotherapeutic agents and easily produced in microbial culture, VHHs are considered promising tools for pharmaceutical biotechnology. With the aim to demonstrate the perspective and potential of VHHs for the development of prophylactic and therapeutic drugs to target diseases caused by bacterial and viral infections, this review article will initially describe the structural features that underlie the unique properties of VHHs and explain the methods currently used for the selection and recombinant production of pathogen-specific VHHs, and then thoroughly summarize the experimental findings of five distinct studies that employed VHHs as inhibitors of host-pathogen interactions or neutralizers of infectious agents. Past and recent studies suggest the potential of camelid heavy-chain variable domains as a novel modality of immunotherapeutic drugs and a promising alternative to monoclonal antibodies. VHHs demonstrate the ability to interfere with bacterial pathogenesis by preventing adhesion to host tissue and sequestering disease-causing bacterial toxins. To protect from viral infections, VHHs may be employed as inhibitors of viral entry by binding to viral coat proteins or blocking interactions with cell-surface receptors. The implementation of VHHs as immunotherapeutic agents for infectious diseases is of considerable potential and set to contribute to public health in the near future.

Robot-based laser drilling system for the detection of concealed threats (2014)

Wild, Dominik ; Theiß, Cathrin ; Kaul, Peter ; Holl, Gerhard

Akustische und optische Echtzeitüberwachung von Bohrprozessen mit passiv-gütegeschaltetem Nd:YAG Laser (2015)

Wild, Dominik ; Kaul, Peter ; Holl, Gerhard

In der vorliegenden Arbeit wird ein neuartiges Verfahren zur Echtzeitüberwachung von Laserbohrprozessen vorgestellt. Die Untersuchungen werden an unterschiedlichen Materialien unter Einsatz eines passiv-gütegeschalteten Nd:YAG Lasers durchgeführt. Prozessbegleitend findet eine Aufzeichnung der akustischen Emissionen mit anschließender Analyse durch schnelle Fourier-Transformation statt. Hierdurch lassen sich der Durchbruch beim Bohren durch ein Material sowie der Materialübergang mehrschichtiger Systeme detektieren. Die akustischen Messungen werden durchAuswertung der Pulsfolge des Lasers mittels einer Fotodiode gestützt. Hierbei zeigt sich eine gute Übereinstimmung der im akustischen Spektrum dominanten Frequenz mit der jeweils im Laserburstauftretenden Pulsfrequenz. Das vorgestellte Verfahren ermöglicht eine Echtzeitüberwachung beim Laserbohren mittels kostengünstiger und einfacher Hardware. Zudem zeichnet es sich im Gegensatz zu bestehenden Verfahren durch eine hohe Robustheit gegen äußere Störeinflüsse aus, da eine frequenzbasierte Auswertung stattfindet.

Zivile Sicherheit: Detektion von Explosivstoffen mittels Laserbohren (2017)

Wild, Dominik ; Kaul, Peter ; Holl, Gerhard

Die Detektion von Explosivstoffen stellt ein zentrales Feld der zivilen Sicherheitsforschung dar. Eine besondere Herausforderung liegt hierbei in dem Nachweis verpackter Substanzen, wie es bei Unkonventionellen Spreng- und Brandvorrichtung (USBV) häufig der Fall ist. Derzeit eingesetzte Verfahren arbeiten meist mit bildgebenden Techniken, durch die sich ein Anfangsverdacht ergibt. Der tatsächliche chemische Inhalt der USBV lässt sich jedoch nicht exakt ermitteln. Eine genaue Beurteilung der Gefährdung durch solche Substanzen ist allerdings von großer Bedeutung, insbesondere wenn die Entschärfung des Objekts in bewohntem Gebiet stattfinden muss. In der vorliegenden Arbeit wird ein Verfahren vorgestellt, das sich als Verifikationsverfahren bei bestehendem Anfangsverdacht gezielt einsetzen lässt. Hierzu wird mittels Laserbohrtechnik zunächst die äußere Hülle des zu untersuchenden Gegenstandes durchdrungen. Anschließend finden eine lasergestützte Probenahme des Inhalts sowie die Detektion unter Verwendung geeigneter Analysemöglichkeiten statt. Der Bohr- und Probenahmefortschritt wird über verschiedene spektroskopische und sensorische Verfahren begleitend überwacht. Zukünftig soll das System abstandsfähig auf Entschärfungsrobotern eingesetzt werden.

Laserbohrverfahren zur Detektion verpackter Gefahrstoffe (2018)

Wild, Dominik

Gegenstand dieser Arbeit sind Untersuchungen zur Detektion von verpackten Gefahrstoffen wie beispielsweise Explosivstoffen. Hierzu wird in einem ersten Schritt die Verpackung mittels Laserbohrens durchdrungen, um anschließend den nun freiliegenden Gefahrstoff nachweisen zu können. Dies geschieht einerseits durch eine lasergestützte Probenahme und anschließende Detektion mit gängigen chemisch-analytischen Verfahren sowie direkt bei der Wechselwirkung zwischen Laser und Gefahrstoff mittels Ramanspektroskopie. Zudem werden schnelle in situ-Techniken im Hinblick auf ihre Eignung zur Überwachung des Laserbohrprozesses untersucht. Hier werden kostengünstige und kompakte Sensortechniken (Messung der Prozessgase durch Halbleitergassensoren, Messung des Luftschalls mittels Kondensatormikrofon) mit aufwendigeren und komplexeren spektroskopischen Verfahren (Plasma- und Ramanspektroskopie) bewertend verglichen. Anhand ausgewählter Modellsysteme in verkleinertem Maßstab werden die unterschiedlichen Verfahren unter Verwendung gängiger Verpackungs- und Hüllenmaterialien sowie anhand ausgewählter Explosivstoffe charakterisiert. Für das Laserverfahren kommen gepulste Nd:YAG Laser mit unterschiedlichen Emissionswellenlängen zum Einsatz.

Remote laser drilling and sampling system for the detection of concealed explosives (2017)

Wild, D. ; Pschyklenk, L. ; Theiß, C. ; Holl, G.

Evolution of Epithelial Sodium Channels - current concepts and hypotheses (2020)

Wichmann, Lukas ; Althaus, Mike

Dem lieben Gott ins Handwerk pfuschen: Risiken und Chancen der Gentechnik (2004)

Weisshaar, Maria-Paz

Die Diskussion über Nutzen und Risiken der Biound Gentechnik beherrschte die Jahre von 1998 bis 2001. Die „grüne Gentechnik“ kämpfte auch 1997 gegen wachsende Widerstände. Erst als sich im Jahr 2001 die Medien mit der „roten“ Gentechnik befassten, sank der Anteil kritischer Vorbehalte und stieg die Akzeptanz gegenüber gentechnisch herstellten Medikamenten in der Bevölkerung. Die Entschlüsselung der menschlichen Erbanlage und die Diskussion um das Klonen von Menschen sowie die Forschung mit embryonalen Stammzellen führte neue Aspekte in die öffentliche Diskussion ein. Die Debatte findet seither auf allen politischen Ebenen statt. Im Zusammenhang mit der Genforschung werden in den Medien immer häufiger Moral und Ökonomie gegenübergestellt und gegeneinander abgewogen. In diesem Wirrwarr von unterschiedlichen und häufig auch widerstreitenden Interessen ist es nicht einfach, sich zurechtzufinden und schließlich zu einer eigenen Position zu gelangen. Umso wichtiger ist daher eine nüchterne Darstellung der Sachverhalte.

Role of exosomes in the management of cellular disease in the geneticsusceptible participants in the Chilean population (2020)

Weisshaar, Maria Paz ; Ghanam, Jamal ; Barra, Rafael ; Rioscan, Miguel ; Escobard, Jorge

Inflammatory molecules are cell-to-cell transported by exosomes in the anti-inflammatory human autologous conditioned serum (2018)

Weisshaar, Maria ; Ghanam, Jamal ; Irsen, Stephan ; Reinecke, Julio ; Wehling, Peter

Background: Local injection of autologous conditioned serum (ACS) is a well-known therapy for inflammatory diseases (IDs). While patients’ blood is incubated to generate ACS (with subsequent centrifugation), immune cells produce high amounts of growth factors and cytokines. This include, amongst others, interleukin-1 receptor antagonist (IL-1ra), interleukins 6 and 10, tumour necrosis factor alpha (TNF-α) and transforming growth factor beta 1 (TGF-β1). The aim of this study was to analyse exosomes release into ACS as well as their cytokine cargo.

Autologous blood derived signaling proteins (sp) for tendon and muscle therapy in sports medicine. Higher concentration of growth factors (gf) and cytokines in orthokine vs in acp (2013)

Weisshaar, M. P. ; Gaji, S.

System accuracy assessments with a blood glucose meter with combined glucose and ß-hydroxybutyrate measurement capabilities (2019)

Weissenbacher, Sylvia ; Yang, Chen-Yu ; Kuan, Tang-Chin ; Demircik, Filiz ; Hanna, Mina ; Pfützner, Andreas

Comparative evaluation of the stada glucocheck monitoring device (2008)

Weise, A. ; Scherze, J. ; Grenningloh, M. ; Schöndorf, T. ; Hauth, W. ; Lipfert, B. ; Forst, T. ; Pfützner, A.

Kriminalistik (2014)

Weihmann, Robert ; Vries, Hinrich de

Vitamin D3-24-Hydroxylase (CYP24) as a Potential Target for Intervention with Diabetic and Nondiabetic Nephropathy (2007)

Weiher, Hans ; Zwacka, Ralf M.

A monoclonal antibody raised against bacterially expressed MPV17 sequences shows peroxisomal, endosomal and lysosomal localisation in U2OS cells (2016)

Weiher, Hans ; Pircher, Haymo ; Jansen-Dürr, Pidder ; Hegenbarth, Silke ; Knolle, Percy ; Grunau, Silke ; Vapola, Miia ; Hiltunen, J. Kalervo ; Zwacka, Ralf M. ; Schmelzer, Elmon ; Reumann, Kerstin ; Will, Hans

Recessive mutations in the MPV17 gene cause mitochondrial DNA depletion syndrome, a fatal infantile genetic liver disease in humans. Loss of function in mice leads to glomerulosclerosis and sensineural deafness accompanied with mitochondrial DNA depletion. Mutations in the yeast homolog Sym1, and in the zebra fish homolog tra cause interesting, but not obviously related phenotypes, although the human gene can complement the yeast Sym1 mutation. The MPV17 protein is a hydrophobic membrane protein of 176 amino acids and unknown function. Initially localised in murine peroxisomes, it was later reported to be a mitochondrial inner membrane protein in humans and in yeast. To resolve this contradiction we tested two new mouse monoclonal antibodies directed against the human MPV17 protein in Western blots and immunohistochemistry on human U2OS cells. One of these monoclonal antibodies showed specific reactivity to a protein of 20 kD absent in MPV17 negative mouse cells. Immunofluorescence studies revealed colocalisation with peroxisomal, endosomal and lysosomal markers, but not with mitochondria. This data reveal a novel connection between a possible peroxisomal/endosomal/lysosomal function and mitochondrial DNA depletion.

Chromatography and Electrophoresis of Nucleic Acids (2011)

Weiher, H. ; Zwacka, R. ; Herr, I.

Hybridization of Nucleic Acids (2011)

Weiher, H. ; Zwacka, R. ; Herr, I.

Isolation of DNA and RNA (2011)

Weiher, H. ; Zwacka, R. ; Herr, I.

Reporting of light irradiation conditions in 300 laboratory studies of resin-composites (2019)

Watts, David C. ; Kaiser, Christina ; O'Neill, Catherine ; Price, Richard Bengt

Detection of triacetone triperoxide using temperature cycled metal-oxide semiconductor gas sensors (2015)

Warmer, Johannes ; Wagner, Patrick ; Schöning, Michael J. ; Kaul, Peter

A distributed sensing platform for the detection of evaporated hazardous material released from moving sources (2009)

Warmer, A. J. ; Mitrovics, J. ; Kaul, P. ; Becher, C.

Safety and security applications often need to gather data from distributed locations and a multitude of instruments and sensors. We have developed a gas sensing platform that communicates via a wireless sensor network based on IEEE 802.15.4 and/or Ethernet. The data form this network is aggregated via a central server that feeds its information over TCP/IP into subsequent data fusion software.

PTEN mutations do not cause nuclear β-catenin accumulation in endometrial carcinomas (2004)

Wappenschmidt, B. ; Wardelmann, E. ; Gehrig, A. ; Schöndorf, T. ; Maass, N. ; Bonatz, G. ; Gassel, A.-M. ; Pietsch, T. ; Mallmann, P. ; Weber, B.H.F. ; Schmutzler, R. K.

Neuartige Geopolymer-gebundene Dämmstoffe aus nachwachsenden Rohstoffen (2019)

Walbrück, Katharina ; Witzleben, Steffen ; Stephan, Dietmar

Entwicklung neuartiger Geopolymer-gebundener Dämmstoffe aus nachwachsenden Rohstoffen (2020)

Walbrück, Katharina ; Witzleben, Steffen

Natural Fiber-Stabilized Geopolymer Foams—A Review (2020)

Walbrück, Katharina ; Maeting, Felicitas ; Witzleben, Steffen ; Stephan, Dietmar

The development of sustainable, environmentally friendly insulation materials with a reduced carbon footprint is attracting increased interest. One alternative to conventional insulation materials are foamed geopolymers. Similar to foamed concrete, the mechanical properties of geopolymer foams can also be improved by using fibers for reinforcement. This paper presents an overview of the latest research findings in the field of fiber-reinforced geopolymer foam concrete with special focus on natural fibers reinforcement. Furthermore, some basic and background information of natural fibers and geopolymer foams are reported. In most of the research, foams are produced either through chemical foaming with hydrogen peroxide or aluminum powder, or through mechanical foaming which includes a foaming agent. However, previous reviews have not sufficiently addresses the fabrication of geopolymer foams by syntactic foams. Finally, recent efforts to reduce the fiber degradation in geopolymer concrete are discussed along with challenges for natural fiber reinforced-geopolymer foam concrete.

Synthesis and Characterization of PVP-Stabilized Palladium Nanoparticles by XRD, SAXS, SP-ICP-MS, and SEM (2019)

Walbrück, Katharina ; Kuellmer, Fabian ; Witzleben, Steffen ; Guenther, Klaus

Due to increased emissions of palladium nanoparticles in recent years, it is important to develop analytical techniques to characterize these particles. The synthesis of defined and stable particles plays a key role in this process, as there are not many materials commercially available yet which could act as reference materials. Polyvinylpyrrolidone- (PVP-) stabilized palladium nanoparticles were synthesized through the reduction of palladium chloride by tetraethylene glycol (TEG) in the presence of KOH. Four different methods were used for particle size analysis of the palladium nanoparticles. Palladium suspensions were analyzed by scanning electron microscopy (SEM), small angle X-ray scattering (SAXS), single-particle ICP-MS (SP-ICP-MS), and X-ray diffraction (XRD). Secondary particles between 30 nm and 130 nm were detected in great compliance with SAXS and SP-ICP-MS. SEM analysis showed that the small particulates tend to form agglomerates.

Structure Investigation of Lignin-based Polyurethanes using WAXS (2017)

Walbrück, Katharina ; Klein, Stefanie ; Rumpf, Jessica ; Schulze, Margit ; Witzleben, Steffen

Factors influencing thermal conductivity and compressive strength of natural fiber-reinforced geopolymer foams (2021)

Walbrück, Katharina ; Drewler, Lisabeth ; Witzleben, Steffen ; Stephan, Dietmar

New sustainable, environmentally friendly materials for thermal insulation of buildings are necessary to reduce their carbon footprints. In this study, Miscanthus fiber-reinforced geopolymer composites, foamed with sodium dodecyl sulfate (SDS), were developed using fly ash as a geopolymer precursor. The effects of fiber content, fiber size, curing temperature, foaming agent content, fumed silica specific surface area and fumed silica content on thermal conductivity and compressive strength were evaluated using a Plackett-Burman design of experiment. Furthermore, the microstructure of geopolymer composites was investigated using X-ray diffraction (XRD), X-ray micro-computed tomography (μCT) and scanning electron microscopy (SEM). The measured characteristic values were in the following ranges: Thermal conductivity 0.057 W (m K)−1 to 0.127 W (m K)−1, compressive strength 0.007 MPa–0.719 MPa and porosity 49 vol% to 76 vol%. The results reveal an enhancement of thermal conductivity by elevated fiber size and foaming agent content. In contrast, the compressive strength is enhanced by high fiber content. Additionally, SEM images indicate a good interaction between the fibers and the geopolymer matrix, because nearly the whole fiber surface is covered by the geopolymer.

Untersuchungen zur Hydrophobierung von Miscanthus X giganteus für den Einsatz in Dämmstoffsystemen (2018)

Walbrück, K. ; Witzleben, S.

Temperature Dependency of Conventional Thermoplastic Polyurethanes and Lignin-based PUR using WAXS (2016)

Walbrueck, Katharina ; Klein, Stephanie ; Rumpf, Jessica ; Schulze, Margit ; Witzleben, Steffen

Polyurethanes (PU) are synthesized through the polyaddition reaction of isocyanates and diols/polyols. Due to their chemical structure and related physical properties, there is a wide range of applications, such as coatings, adhesives, foams for construction and packaging.

Neuer Studiengang Forensik - Zur Einrichtung im Fachbereich Angewandte Naturwissenschaften an der Hochschule Bonn-Rhein-Sieg (2009)

Vries, Hinrich de

Rechtssätze und Erfahrungssätze: Das Verhältnis von Strafrecht und Kriminalistik (2017)

Vries, Hinrich de

Einführung in die Kriminalistik für die Strafrechtspraxis (2015)

Vries, Hinrich de

Mit dieser "Einführung in die Kriminalistik" erhält der Leser eine Übersicht zu den zahlreichen Facetten der Sachverhaltserforschung im Strafrecht.

OCTs, OATs, and OCTNs: structure and function of the polyspecific organic ion transporters of the SLC22 family (2013)

Volk, Christopher

Endoplasmic reticulum stress and the unfolded protein response: targeting the Achilles heel of multiple myeloma (2013)

Vincenz, Lisa ; Jäger, Richard ; O'Dwyer, Michael ; Samali, Afshin

Multiple myeloma is characterized by the malignant proliferating antibody-producing plasma cells in the bone marrow. Despite recent advances in therapy that improve the survival of patients, multiple myeloma remains incurable and therapy resistance is the major factor causing lethality. Clearly, more effective treatments are necessary. In recent years it has become apparent that, as highly secretory antibody-producing cells, multiple myeloma cells require an increased capacity to cope with unfolded proteins and are particularly sensitive to compounds targeting proteostasis such as proteasome inhibitors, which represent one of the most prominent new therapeutic strategies. Because of the increased requirement for dealing with secretory proteins within the endoplasmic reticulum, multiple myeloma cells are heavily reliant for survival on a set of signaling pathways, known as the unfolded protein response (UPR). Thus, directly targeting the UPR emerges as a new promising therapeutic strategy. Here, we provide an overview of the current understanding of the UPR signaling in cancer, and outline its important role in myeloma pathogenesis and treatment. We discuss new therapeutic approaches based on targeting the protein quality control machinery and particularly the IRE1α/XBP1 axis of the UPR.

Mass Spectrometry | Pyrolysis (2005)

Twyman, Richard M. ; Kusch, Peter

Mass Spectrometry: Pyrolysis (2019)

Twyman, Richard M. ; Kusch, Peter

Acylpeptide hydrolase (APEH) sequence variants with potential impact on the metabolism of the antiepileptic drug valproic acid (2019)

Tsortouktzidis, Despina ; Grundke, Kathleen ; Till, Claudia ; Korwitz-Reichelt, Anne ; Sass, Jörn Oliver

Mesenchymal Stem Cells (2020)

Tonk, Christian Horst ; Witzler, Markus ; Schulze, Margit ; Tobiasch, Edda

This chapter focuses on mesenchymal stem cells (MSCs), a multipotent stem cell type that has been found in a variety of tissues and organs of the human body since their discovery in 1970. Their main function is to maintain and repair the respective tissue in vivo. Mesenchymal stem cells can be easily isolated from different tissues and can undergo extensive self-proliferation prior to differentiation into various mesodermal cell types such as osteoblasts, chondrocytes, adipocytes, tenocytes, myocytes, and fibroblasts. Because of this vast differentiation potential, mesenchymal stem cells are a promising tool for regenerative medicine approaches. They could play an important role in cellular therapy, tissue replacement and regeneration in the future. Mesenchymal stem cells will be compared for their application and differentiation potential to embryonic stem cells and induced pluripotent stem cells and the limitations and challenges using scaffolds for tissue repair will be presented. In addition, legal and ethical aspects of the use of mesenchymal stem cells will be discussed. Moreover, isolation protocols for mesenchymal stem cells from the most common sources namely bone marrow, adipose tissue and umbilical cord are included.

P2 receptors influence differentiation in human mesenchymal and ectomesenchymal stem cells (2010)

Tobiasch, Edda ; Zippel, Nina ; Scholze, Nadine ; Limbach, Christian ; Urban, Christian ; Luparello, Claudio ; Pansky, Andreas ; Kassack, Matthias

The Artificial Purinergic Receptor Antagonists A 740003 and MRS 2500 Enhance Mesenchymal Stem Cell Differentiation Towards Osteoblasts via P2X7 and P2Y1 Receptors (2017)

Tobiasch, Edda ; Ottensmeyer, Patrick ; Witzler, Markus ; Schulze, Margit

A major threat of the ageing population is the risk of fractures on account of osteoporosis where an imbalance between bone formation via osteoblasts and bone degradation by osteoclasts is present that is prone to the latter.

Purinergic signaling in mesenchymal stem cell differentiation (2018)

Tobiasch, Edda ; Hielscher, Dorothee ; Ottensmeyer, Patrick ; Babczyk, Patrick ; Zhang, Yu ; Schulze, Margit

Enhanced Osteogenesis and Angiogenesis for Putative Bone Grafts by Activating Purinergic Receptor Signaling During Mesenchymal Stem Cell Differentiation (2019)

Tobiasch, Edda ; Bröker, Vanessa ; Shoushrah, Sarah ; Schulze, Margit

Differentiation Potential of Adult Human Mesenchymal Stem Cells (2011)

Tobiasch, Edda

Adult Human Mesenchymal Stem Cells as Source for Future Tissue Engineering (2009)

Tobiasch, Edda

Embryonic stem cells (ES) have the potential of long-term viability, selfrenewal and pluripotency which makes them interesting candidates for tissue engineering and gene therapy applications. On the other hand ethical and political issues arise while using theses cells and severe problems such as their tumorgenicity have not been solved yet. In the last couple of month a new source of cells with stem cell character was developed, the induced pluripotent stem cells (iPS). These cells are derived from differentiated adult cells via transduction of three transcription factors and show features similar to embryonic stem cells. Unfortunately, this includes the tumorgenicity which is even higher in those cells since the transcription factor transduction needed until now, is performed with retrovial vectors, which have a tumor potential on their own. Thus, adult stem cells are investigated extensively as alternative source of self-renewing cells. Human mesenchymal stem cells (HMSCs), which have in addition the advantage of potential autologous transplantation, can be found in various differentiated tissues since they are needed for maintenance and repair. They can be differentiated in chondrogenic, osteogenic, adipogenic and myogenic lineages which makes them an excellent tool for future tissue replacement strategies.

Untersuchung zur Rolle ausdifferenzierender Adipozyten bei der Pathogenese des Diabetes mellitus Typ 2, Kurztitel: AdiPaD (2010)

Tobiasch, Edda

Insulin und Proinsulin haben eine vergleichbare adipogenetische Potenz bei der Ausdifferenzierung mesenchymaler Stammzellen in vitro (2006)

Tobiasch, E. ; Pansky, A. ; Maiworm, A. ; Scherer, S. ; Forst, T. ; Pfützner, A.

Solar-mediated degradation of linezolid and tedizolid under simulated environmental conditions: Kinetics, transformation and toxicity (2020)

Timm, Alexander ; Abendschön, Patrick ; Tölgyesi, László ; Horn, Harald ; Borowska, Ewa

Genetic CD21 deficiency is associated with hypogammaglobulinemia (2012)

Thiel, Jens ; Kimmig, Lucas ; Salzer, Ulrich ; Grudzien, Magdalena ; Lebrecht, Dirk ; Hagena, Tina ; Draeger, Ruth ; Voelxen, Nadine ; Völxen, Nadine ; Bergbreiter, Astrid ; Jennings, Stephanie ; Gutenberger, Sylvia ; Aichem, Annette ; Illges, Harald ; Hannan, Jonathan P. ; Kienzler, Anne-Kathrin ; Rizzi, Marta ; Eibel, Hermann ; Peter, Hans-Hartmut ; Warnatz, Klaus ; Grimbacher, Bodo ; Rump, Jörg-Andres ; Schlesier, Michael

DNA profiling of sperm cells by using micromanipulation and whole genome amplification (2017)

Theunissen, Glenn M. G. ; Rolf, Burkhard ; Gibb, Andrew ; Jäger, Richard

DNA profiling of single sperm cells and single skin flakes in forensics using micromanipulation and whole genome amplification (2020)

Theunissen, Glenn M. G.

In forensic DNA profiling, the occurrence of complex mixed profiles is currently a common issue. Cases involving intimate swabs or skin flake tape liftings are prone to mixed profiles, because of more than one donor contributing to a DNA sample. By DNA profiling of single spermatozoa and skin flakes, problems associated with mixed profile could ideally be overcome. However, PCR is not a sensitive enough method to generate DNA profiles by STRs on single cells. Moreover, high quality intact DNA is required, but is not always available in skin flakes due to degradation. Additionally, single skin flakes are difficult to discriminate from other similar looking particles on tape liftings used to secure DNA samples from evidence. The main purpose of this study was to develop a method that enables DNA profiling of single sperm cells and skin flakes. After studying multiple whole genome amplification (WGA) protocols, REPLI-g Single Cell WGA was selected due to its suitability in the pre-amplification step of template DNA. Micromanipulation was used to isolate single spermatozoa. Furthermore, micromanipulation in combination with REPLI-g Single Cell WGA resulted in successful DNA profiling of single spermatozoa by using autosomal STRs as well as X- and Y-chromosomal STRs. The single spermatozoa DNA profiling method described in this thesis was successfully used to identify male contributors from mock intimate swabs with a mixture of semen from multiple male contributors. Different dyes were analysed to develop a staining method to discriminate skin flakes from other particles including particles such as those from hair cosmetic products. From all dyes tested, Orange G was the only dye which successfully discriminated skin flakes from hair product particles. Also, an alkaline based lysis protocol was developed that allowed PCR to be carried out directly on the lysates of single skin flakes. Furthermore, REPLI-g Single Cell WGA was tested on single skin flakes. In contrast to the single spermatozoa, REPLI-g Single Cell WGA was not successful in DNA profiling of single skin flakes. The single skin flake DNA profiling method described in this thesis was successfully used in correctly identifying contributors from mock mixed DNA evidence. Additionally, a small amplicon-based NGS method was tested on single skin flakes. Compared to the PCR and CE approach, the small amplicon-based NGS method improved DNA profiling of single skin flakes, giving a significant increase in allele recovery. In conclusion, this study shows circumventing mixtures is possible by DNA profiling of single spermatozoa, using micromanipulation and WGA. Furthermore, DNA profiling of single skin flakes has been improved by the staining of tape liftings methodology with Orange G, alkaline lysis, direct-PCR and a small amplicon-based NGS approach. Nonetheless, future work is required to assess the performance of the single spermatozoa method on mock swabs with more diluted semen. Also, commercially available NGS kits should be tested with single skin flakes and compared with the in-house NGS method.

d-Glyceric aciduria does not cause nonketotic hyperglycinemia: A historic co-occurrence (2017)

Swanson, Michael A. ; Garcia, Stephanie M. ; Spector, Elaine ; Kronquist, Kathryn ; Creadon-Swindell, Geralyn ; Walter, Melanie ; Christensen, Ernst ; van Hove, Johan L.K. ; Sass, Jörn Oliver

Spatial patterning of nanofibrous collagen scaffolds modulates fibroblast morphology (2021)

Suter, Naiana ; Stebel, Sophie ; Rianna, Carmela ; Radmacher, Manfred ; Brüggemann, Dorothea

Current knowledge about cell-biomaterial interactions is often based on 2D cell culture systems like protein-coated glass slides. However, such smooth surfaces cannot mimic the nanofibrous environment of the native extracellular matrix (ECM). It is therefore a major challenge to transfer the results from 2D surfaces to 3D protein scaffolds with biomimetic nanofiber architecture. To understand the influence of different protein topographies on the cell response we introduce a new process to fabricate binary collagen scaffolds of variable thickness with spatially controlled regions of nanofibrous and smooth topography. We used pH-induced self-assembly to prepare collagen nanofibers with diameters between 130 and 150 nm on glass surfaces, which were partly covered with a polymer mask. After cross-linking with glutaraldehyde, smooth collagen films were prepared on the remaining glass regions. Atomic force microscopy revealed a much lower surface roughness of smooth collagen compared to nanofibers.

Designer Drugs and Trace Explosives Detection with the Help of Very Recent Advancements in Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) (2012)

Sulzer, Philipp ; Jürschik, Simone ; Agarwal, Bishu ; Kassebacher, Thomas ; Hartungen, Eugen ; Edtbauer, Achim ; Petersson, Fredrik ; Warmer, Johannes ; Holl, Gerhard ; Perry, Dave ; Mayhew, Christopher A. ; Märk, Tilmann D.

At the "Future Security 2011" we presented an overview of our studies on the "Detection and Identification of Illicit and Hazardous Substances with Proton-Transfer-Reaction Mass Spectrometry (PTR-MS)" including first results on explosives, chemical warfare agents and illicit and prescribed drugs detection. Since then we have considerably extended these preliminary studies to the detection of defined traces of some of the most common explosives, namely TNT, PETN, TATP, and DATP deposited into aluminum foam bodies, and to the detection of a number of novel and widely unknown designer drugs: ethylphenidate, 4-fluoroamphetamine and dimethocaine. Moreover, we have dramatically improved our time-of-flight based PTR-MS instruments by substantially increasing their sensitivity and hence lowering the detection limit, making them even more suitable and applicable to threat agents with extremely low vapour pressures. Data from measurements on certified gas standards are presented in order to underline these statements. The data demonstrate that, in comparison to the first generation instruments, a gain of one order of magnitude in terms of sensitivity and detection limit has been obtained.

Tamoxifen treatment in breast cancer induces a cytoplasmic complex consisting of endothelin-1, estrogen receptors, and Tamoxifen leading to nuclear transmigration, and transcription of target genes involved in metastatic spread (2013)

Straube, Julia ; Brandenstein, Melanie von ; Geisbuesch, Christina ; Ozretic, Luca ; Depping, Reinhard ; Fries, Jochen W. U.

Tamoxifen therapy of invasive breast cancer has been associated with increased levels of endothelin-1 (ET-1) so that an endothelin-1 receptor (ETR) blockade has been suggested as a new therapeutic approach. This study analyzed the relationship between Tamoxifen and ET-1 signalling in invasive breast cancer. Using paraffinized tissue from 50 randomly chosen cases of invasive and in-situ ductal carcinoma from our archive, the expression of ETRs was analyzed by immune histology. ETRs were regularly detectable in normal breast tissue, but rarely in adjacent tumor areas (3/50 cases). By immunoprecipitation, a complex was found consisting of ET-1, estrogen receptors and Tamoxifen. Consequently, transcription of several target genes of ET-1 and estrogen receptors was detectable (interleukin-6, wnt-11 and a vimentin spliceform). In particular, the combination of Tamoxifen, ET-1, and estrogen receptors induced further increasing levels of these target genes. Some of these genes have been found upregulated in metastatically spreading breast cancer cells. We conclude: i) ETRs do not play a role in invasive or in-situ ductal breast cancer; ii) estrogen receptors and Tamoxifen build a complex with ET-1; and iii) upregulated transcription of target genes by ET-1–estrogen receptor–Tamoxifen complex may negatively influence breast cancer prognosis. These results indicate a role for ET-1 in Tamoxifen treated breast cancer patients leading to a potentially worsening prognosis.

Genotoxicity testing on the international space station: Preparatory work on the SOS-LUX test as part of the space experiment TRIPLE-LUX (2005)

Stojicic, Nevena ; Walrafen, David ; Baumstark-Khan, Christa ; Rabbow, Elke ; Rettberg, Petra ; Weisshaar, Maria-Paz ; Horneck, Gerda

Essential Roles of Raf/Extracellular Signal-regulated Kinase/Mitogen-activated Protein Kinase Pathway, YY1, and Ca2+ Influx in Growth Arrest of Human Vascular Smooth Muscle Cells by Bilirubin (2012)

Stoeckius, Marlon ; Erat, Anna ; Fujikawa, Tatsuya ; Hiromura, Makoto ; Koulova, Anna ; Otterbein, Leo ; Bianchi, Cesario ; Tobiasch, Edda ; Dagon, Yossi ; Sellke, Frank W. ; Usheva, Anny

CIK Cells and HDAC Inhibitors in Multiple Myeloma (2017)

Stephan, David ; Weiher, Hans ; Schmidt-Wolf, Ingo G. H.

Multiple myeloma is the second most common hematological malignancy. Despite all the progress made in treating multiple myeloma, it still remains an incurable disease. Patients are left with a median survival of 4-5 years. The combined treatment of multiple myeloma with histone deacetylase inhibitors and cytokine-induced killer cells provides a promising targeted treatment option for patients. This study investigated the impact of a combined treatment compared to treatment with histone deacetylase inhibitors. The experiments revealed that a treatment with histone deacetylase (HDAC) inhibitors could reduce cell viability to 59% for KMS 18 cell line and 46% for the U-266 cell line. The combined treatment led to a decrease of cell viability to 33% for KMS 18 and 27% for the U-266 cell line, thus showing a significantly better efficacy than the single treatment.

Entwicklung von wissenschaftlichen Kriterien zur Bewertung der Suchleistung geruchsdifferenzierender Hunde (2017)

Stelzig, S. ; Al Jabri, A. ; Holl, G.

Vor Gericht werden Einsätze geruchsdifferenzierender Hunde derzeit nur unter bestimmten Voraussetzungen als Indizien-Beweis zugelassen (dokumentierter, ausreichender Ausbildungsstand des Hundes, Bestätigung der Suche durch zweiten Hund). Oft sind Leistungsgrenzen der Hunde hinsichtlich Alter der Geruchsspur, Einfluss bestimmter Witterungsbedingungen (Temperatur, Feuchtigkeit, etc.) auf die Detektierbarkeit menschlicher Geruchsspuren unklar und umstritten. Auch ist bis heute nicht wissenschaftlich untersucht, welche Bestandteile und Einzelsubstanzen des humanen Geruchs für die Hunde tatsächlich wahrnehmbar und wichtig zur Personensuche und -identifikation sind. Daher widmet sich ein aktuelles Promotionsprojekt im Institut für Detektionstechnologien der Erforschung dieser Fragen.

Dielectric analysis of depth dependent curing behavior of dental resin composites (2014)

Steinhaus, Johannes ; Moeginger, Bernhard ; Grossgarten, Mandy ; Rosentritt, Martin ; Hausnerova, Berenika

Application of Pyrolysis–Gas Chromatography–Mass Spectrometry for the Identification of Polymeric Materials (2014)

Steinhaus, Johannes ; Knupp, Gerd ; Fink, Wolfgang ; Obst, Volker ; Schroeder-Obst, Dorothee ; Kusch, Peter

The analytical pyrolysis technique hyphenated to gas chromatography–mass spectrometry (GC–MS) has extended the range of possible tools for the characterization of synthetic polymers and copolymers. Pyrolysis involves thermal fragmentation of the analytical sample at temperatures of 500–1400 °C. In the presence of an inert gas, reproducible decomposition products characteristic for the original polymer or copolymer sample are formed. The pyrolysis products are chromatographically separated using a fused-silica capillary column and are subsequently identified by interpretation of the obtained mass spectra or by using mass spectra libraries. The analytical technique eliminates the need for pretreatment by performing analyses directly on the solid or liquid polymer sample. In this article, application examples of analytical pyrolysis hyphenated to GC–MS for the identification of different polymeric materials in the plastic and automotive industry, dentistry, and occupational safety are demonstrated. For the first time, results of identification of commercial light-curing dental filling material and a car wrapping foil by pyrolysis–GC–MS are presented.

Das Härtungsverhalten verschiedener Dentalkomposite - Vergleichende Untersuchung mittels dielektrischer Analyse (DEA) (2017)

Steinhaus, Johannes ; Kehret, Lara ; Wieland, Michael ; Möginger, Bernhard

Dentalkomposite sind hochkomplexe Materialsysteme. Bei der Materialentwicklung gilt es in der Regel, die wichtigen Eigenschaften wie Aushärtungszeit, Schrumpfung, Verarbeitbarkeit, Einhärtetiefe, finale mechanische Eigenschaften, Polierbarkeit sowie die Biokompatibilität zu verbessern.

Characterization of the auto-curing behavior of rapid prototyping materials for three-dimensional printing using dielectric analysis (2015)

Steinhaus, Johannes ; Hausnerova, Berenika ; Moeginger, Bernhard ; Harrach, Mohamed ; Guenther, Daniel ; Moegele, Florian

Correlation of shear and dielectric ion viscosity of dental resins – Influence of composition, temperature and filler content (2016)

Steinhaus, Johannes ; Hausnerova, Berenika ; Haenel, Thomas ; Selig, Daniela ; Duvenbeck, Fabian ; Moeginger, Bernhard

Curing kinetics of visible light curing dental resin composites investigated by dielectric analysis (DEA) (2014)

Steinhaus, Johannes ; Hausnerova, Berenika ; Haenel, Thomas ; Großgarten, Mandy ; Möginger, Bernhard

Dielectric Analysis of Short-Term and Long-Term Curing of Novel Photo-Curing Dental Filling Materials (2010)

Steinhaus, Johannes ; Frentzen, Matthias ; Rosentritt, Martin ; Möginger, Bernhard

Correlating mechanical rubber properties with moving die rheometer vulcanization curves under consideration of the material composition (2019)

Steinhaus, Johannes ; Almeida, Andre ; Lantermann, Ulrich ; Moeginger, Bernhard

Real-time Investigation of Curing Mechanisms of Thermoset Resins for Medical and Technical Applications (2015)

Steinhaus, Johannes

In this doctoral thesis the curing process of visible light-curing (VLC) dental composites and 3D printing rapid prototyping (RP) materials are investigated with the focus on dielectric analysis (DEA). This method is able to monitor the curing of resins in an alternating electric fringe field with adjustable frequencies and is often used for cure control of composites manufacturing in the aviation and automotive industry but hardly established in dental science or RP method development. It is capable of investigating very fast initiation and primary curing processes using high frequencies in the kHz-range. The aim of the Thesis is a better understanding of the curing processes with respect to curing parameters such as resin composition, viscosity, temperature, and for light-curing composites also light intensity and irradiation depth. Due to the nature of both dental and RP systems an application of specific experimental set-up had to be designed allowing for the generation of reproducible and valid results. Subsequently, different evaluation methods were developed to characterize the curing behavior of both material types. A special focus was paid to the determination of kinetic parameters from DEA measurements. Reaction rates of the curing of the corresponding thermosets were calculated and applied to the ion viscosity curves measured by DEA to evaluate reaction kinetic parameters. For the dental composites it could be clearly shown that the initial curing rate is directly proportional to light intensity and not to its square root as proposed by many others authors. A good description of the curing behaviour of 3DP RP materials was also achieved assuming a reaction order smaller than one. This data provides the base for the kinetic modeling of polymerization and curing processes proposed within the Thesis.

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