46 research outputs found
Effect of surface functionalized titanium implants with sustained release characteristics of strontium in healthy and osteoporotic bone conditions – "in vivo" investigations
No full textZielstellung
Aufbauend auf dem Wissen um das osteoinduktive Potential von Strontium (Sr), war das Ziel dieser Studie die Entwicklung einer bioaktiven Implantatoberfläche, welche durch kontrollierte Sr – Freisetzung zu einer verbesserten Osseointegration führen soll.
Material und Methode
Verschiedene experimentelle Gruppen wurden mittels Physical Vapor Deposition (PVD) hergestellt und hinsichtlich Zusammensetzung, Morphologie, mechanischer Stabilität und Sr – Freisetzungsprofilen evaluiert. In vivo Untersuchungen wurden an gesunden bzw. ovariektomierten weiblichen Wistar Ratten mittels bikortikaler Insertion von funktionalisierten Titanimplantaten in beide Femora bzw. proximale Tibia durchgeführt. Die histomorphometrische Auswertung bezüglich „bone-to-implant contact“ (BIC) und „bone apposition“ (BA) erfolgte nach 30-tägiger bzw. 6-wöchiger Einheilungsphase.
Ergebnisse
Strukturelle Unterschiede, basierend auf Sr – Konzentration von 5,2 at.% bis 9,1 at.% in der Oberfläche, wurden festgestellt. Daraus resultierten verschiedene Sr – Freisetzungsprofile mit signifikanten Unterschieden innerhalb der experimentellen Gruppen. Die erhöhte Knochenanlagerung und -neubildung in vivo korreliert mit der Höhe des freigesetzten Sr in vitro.
Schlussfolgerung
Die vorgelegten Untersuchungen zeigen den osteoinduktiven Effekt kontrollierter Sr – Freisetzung an der Implantatoberfläche auf Knochenneubildung und –anlagerung.
Die Entwicklung einer neuen bioaktiven Oberfläche mittels PVD-Coating mit einer prolongierten Freisetzung von Sr ist ein neuer Ansatz zur Verbesserung der Osseointegration mit potentiellen Anwendungsmöglichkeiten in der orthopädischen und dentalen Implantologie.Objective: Studies have shown that incorporation of strontium (Sr) into implant surfaces may enhance osseointegration. Thus, we suggested that a sustained Sr release from implant surfaces could improve bone healing and thereby accelerate osseointegration. The performed studies evaluate and further investigate the effect of a novel Ti-Sr-O functionalized implant surface prepared from a magnetron co-sputtering platform with a continuous release of Sr and its impact on osseointegration in rodent models with healthy and osteoporotic bone conditions.
Material and methods: Several experimental Ti-Sr-O groups were tested throughout 3 conducted in vivo studies. These groups differed from each other in Sr contents and pre-wash procedures. Implants were prepared with a Ti-Sr-O coating by means of magnetron co-sputtering and compared to an uncoated Grade 4 titanium reference. Composition, morphology and mechanical stability of the coatings were analysed; Sr release data were gained from in vitro washout experiments. In vivo investigations were carried out in rat models and analyzed histologically regarding bone-to-implant contact and new bone formation 30 days and 6 weeks after implantation.
Results: Structural differences were detected between the developed Ti-Sr-O coatings with Sr contents ranging from 5.2 at.% to 9.1 at.%. As a result of the varying Sr contents in the surface different release profiles were observed with significant discrepancy within the experimental groups. The increase in new bone formation in vivo was found to correlate with the amount of Sr released in vitro.
Conclusion: The results show that sputtered Ti-Sr-O coatings with sustained release of Sr may improve osseointegration, and could thus have impact on practical applications for medical devices in orthopedic and dental implantology.Vincent OffermannsInnsbruck, Med. Univ., Diss., 201
Effect of surface functionalized titanium implants with sustained release characteristics of strontium in healthy and osteoporotic bone conditions – "in vivo" investigations
No full textZielstellung
Aufbauend auf dem Wissen um das osteoinduktive Potential von Strontium (Sr), war das Ziel dieser Studie die Entwicklung einer bioaktiven Implantatoberfläche, welche durch kontrollierte Sr – Freisetzung zu einer verbesserten Osseointegration führen soll.
Material und Methode
Verschiedene experimentelle Gruppen wurden mittels Physical Vapor Deposition (PVD) hergestellt und hinsichtlich Zusammensetzung, Morphologie, mechanischer Stabilität und Sr – Freisetzungsprofilen evaluiert. In vivo Untersuchungen wurden an gesunden bzw. ovariektomierten weiblichen Wistar Ratten mittels bikortikaler Insertion von funktionalisierten Titanimplantaten in beide Femora bzw. proximale Tibia durchgeführt. Die histomorphometrische Auswertung bezüglich „bone-to-implant contact“ (BIC) und „bone apposition“ (BA) erfolgte nach 30-tägiger bzw. 6-wöchiger Einheilungsphase.
Ergebnisse
Strukturelle Unterschiede, basierend auf Sr – Konzentration von 5,2 at.% bis 9,1 at.% in der Oberfläche, wurden festgestellt. Daraus resultierten verschiedene Sr – Freisetzungsprofile mit signifikanten Unterschieden innerhalb der experimentellen Gruppen. Die erhöhte Knochenanlagerung und -neubildung in vivo korreliert mit der Höhe des freigesetzten Sr in vitro.
Schlussfolgerung
Die vorgelegten Untersuchungen zeigen den osteoinduktiven Effekt kontrollierter Sr – Freisetzung an der Implantatoberfläche auf Knochenneubildung und –anlagerung.
Die Entwicklung einer neuen bioaktiven Oberfläche mittels PVD-Coating mit einer prolongierten Freisetzung von Sr ist ein neuer Ansatz zur Verbesserung der Osseointegration mit potentiellen Anwendungsmöglichkeiten in der orthopädischen und dentalen Implantologie.Objective: Studies have shown that incorporation of strontium (Sr) into implant surfaces may enhance osseointegration. Thus, we suggested that a sustained Sr release from implant surfaces could improve bone healing and thereby accelerate osseointegration. The performed studies evaluate and further investigate the effect of a novel Ti-Sr-O functionalized implant surface prepared from a magnetron co-sputtering platform with a continuous release of Sr and its impact on osseointegration in rodent models with healthy and osteoporotic bone conditions.
Material and methods: Several experimental Ti-Sr-O groups were tested throughout 3 conducted in vivo studies. These groups differed from each other in Sr contents and pre-wash procedures. Implants were prepared with a Ti-Sr-O coating by means of magnetron co-sputtering and compared to an uncoated Grade 4 titanium reference. Composition, morphology and mechanical stability of the coatings were analysed; Sr release data were gained from in vitro washout experiments. In vivo investigations were carried out in rat models and analyzed histologically regarding bone-to-implant contact and new bone formation 30 days and 6 weeks after implantation.
Results: Structural differences were detected between the developed Ti-Sr-O coatings with Sr contents ranging from 5.2 at.% to 9.1 at.%. As a result of the varying Sr contents in the surface different release profiles were observed with significant discrepancy within the experimental groups. The increase in new bone formation in vivo was found to correlate with the amount of Sr released in vitro.
Conclusion: The results show that sputtered Ti-Sr-O coatings with sustained release of Sr may improve osseointegration, and could thus have impact on practical applications for medical devices in orthopedic and dental implantology.Vincent OffermannsInnsbruck, Med. Univ., Diss., 201
Effect of surface functionalized titanium implants with sustained release characteristics of strontium in healthy and osteoporotic bone conditions – "in vivo" investigations
No full textZielstellung
Aufbauend auf dem Wissen um das osteoinduktive Potential von Strontium (Sr), war das Ziel dieser Studie die Entwicklung einer bioaktiven Implantatoberfläche, welche durch kontrollierte Sr – Freisetzung zu einer verbesserten Osseointegration führen soll.
Material und Methode
Verschiedene experimentelle Gruppen wurden mittels Physical Vapor Deposition (PVD) hergestellt und hinsichtlich Zusammensetzung, Morphologie, mechanischer Stabilität und Sr – Freisetzungsprofilen evaluiert. In vivo Untersuchungen wurden an gesunden bzw. ovariektomierten weiblichen Wistar Ratten mittels bikortikaler Insertion von funktionalisierten Titanimplantaten in beide Femora bzw. proximale Tibia durchgeführt. Die histomorphometrische Auswertung bezüglich „bone-to-implant contact“ (BIC) und „bone apposition“ (BA) erfolgte nach 30-tägiger bzw. 6-wöchiger Einheilungsphase.
Ergebnisse
Strukturelle Unterschiede, basierend auf Sr – Konzentration von 5,2 at.% bis 9,1 at.% in der Oberfläche, wurden festgestellt. Daraus resultierten verschiedene Sr – Freisetzungsprofile mit signifikanten Unterschieden innerhalb der experimentellen Gruppen. Die erhöhte Knochenanlagerung und -neubildung in vivo korreliert mit der Höhe des freigesetzten Sr in vitro.
Schlussfolgerung
Die vorgelegten Untersuchungen zeigen den osteoinduktiven Effekt kontrollierter Sr – Freisetzung an der Implantatoberfläche auf Knochenneubildung und –anlagerung.
Die Entwicklung einer neuen bioaktiven Oberfläche mittels PVD-Coating mit einer prolongierten Freisetzung von Sr ist ein neuer Ansatz zur Verbesserung der Osseointegration mit potentiellen Anwendungsmöglichkeiten in der orthopädischen und dentalen Implantologie.Objective: Studies have shown that incorporation of strontium (Sr) into implant surfaces may enhance osseointegration. Thus, we suggested that a sustained Sr release from implant surfaces could improve bone healing and thereby accelerate osseointegration. The performed studies evaluate and further investigate the effect of a novel Ti-Sr-O functionalized implant surface prepared from a magnetron co-sputtering platform with a continuous release of Sr and its impact on osseointegration in rodent models with healthy and osteoporotic bone conditions.
Material and methods: Several experimental Ti-Sr-O groups were tested throughout 3 conducted in vivo studies. These groups differed from each other in Sr contents and pre-wash procedures. Implants were prepared with a Ti-Sr-O coating by means of magnetron co-sputtering and compared to an uncoated Grade 4 titanium reference. Composition, morphology and mechanical stability of the coatings were analysed; Sr release data were gained from in vitro washout experiments. In vivo investigations were carried out in rat models and analyzed histologically regarding bone-to-implant contact and new bone formation 30 days and 6 weeks after implantation.
Results: Structural differences were detected between the developed Ti-Sr-O coatings with Sr contents ranging from 5.2 at.% to 9.1 at.%. As a result of the varying Sr contents in the surface different release profiles were observed with significant discrepancy within the experimental groups. The increase in new bone formation in vivo was found to correlate with the amount of Sr released in vitro.
Conclusion: The results show that sputtered Ti-Sr-O coatings with sustained release of Sr may improve osseointegration, and could thus have impact on practical applications for medical devices in orthopedic and dental implantology.Vincent OffermannsInnsbruck, Med. Univ., Diss., 201
A comparative in vivo study of strontium-functionalized and SLActive™ implant surfaces in early bone healing
No full textVincent Offermanns,1 Ole Z Andersen,2 Michael Sillassen,2 Klaus P Almtoft,3 Inge H Andersen,3 Frank Kloss,4 Morten Foss2,5 1Department of Cranio-Maxillofacial and Oral Surgery, Medical University of Innsbruck, Innsbruck, Austria; 2Interdisciplinary Nanoscience Center (iNANO), Faculty of Science and Technology, Aarhus University, Aarhus, Denmark; 3Tribology Center, Danish Technological Institute, Aarhus, Denmark; 4Private Practice, Lienz, Austria; 5Department of Physics and Astronomy, Faculty of Science and Technology, Aarhus University, Aarhus, Denmark Purpose: Studies have shown that strontium-doped medical applications benefit bone metabolism leading to improved bone healing and osseointegration. Based on this knowledge, the aim of the study was to evaluate the performance of an implant surface, functionalized by a physical vapor deposition (PVD) coating (Ti-Sr-O), designed to yield predictable release of strontium. The Ti-Sr-O functionalized surface is compared to a routinely used, commercially available surface (SLActive™) with respect to bone-to-implant contact (BIC%) and new bone formation (BF%) in two defined regions of interest (ROI-I and ROI-II, respectively).Materials and methods: Ti-Sr-O functionalized, SLActive, and Grade 4 titanium implants were inserted in the femoral condyle of adult male New Zealand White rabbits. The PVD magnetron-sputtered Ti-Sr-O surface coating was characterized using scanning electron microscopy (SEM) for morphology and coating thickness. Strontium release and mechanical stability of the coating, under simulated insertion conditions, were evaluated. Furthermore, histomorphometrical BIC and BF were carried out 2 weeks after insertion.Results: Histomorphometry revealed increased bone formation of Ti-Sr-O with significant differences compared to SLActive and Grade 4 titanium in both regions of interest, ROI-I and ROI-II, at 0–250 µm and 250–500 µm distance from the implant surfaces. Analogous results of bone-to-implant contact were observed for the two modified surfaces. Conclusion: The results show that a nanopatterned Ti-Sr-O functionalized titanium surface, with sustained release of strontium, increases peri-implant bone volume and could potentially contribute to enhancement of bone anchorage of osseointegrated implants. Keywords: biofunctionalization, wettability, physical vapor deposition, bioactive, surface modification, bone 
Dataset of Publication "Malware Communication in Smart Factories: A Network Traffic Data Set"
No full text<p><strong>Note: If you use this dataset, please cite the following paper: </strong></p>
<p>Brenner, B., Fabini, J., Offermanns, M., Semper, S., & Zseby, T. (2024). Malware communication in smart factories: A network traffic data set. Computer Networks, 255, 110804.</p>
<p>or in BibTeX:</p>
<p>@article{brenner2024malware,<br> title={Malware communication in smart factories: A network traffic data set},<br> author={Brenner, Bernhard and Fabini, Joachim and Offermanns, Magnus and Semper, Sabrina and Zseby, Tanja},<br> journal={Computer Networks},<br> volume={255},<br> pages={110804},<br> year={2024},<br> publisher={Elsevier}<br>}</p>
<p> </p>
<h3>Context and methodology</h3>
<p>Machine learning-based intrusion detection requires suitable and realistic data sets for training and testing. However, data sets that originate from real networks are rare. Network data is considered privacy-sensitive, and the purposeful introduction of malicious traffic is usually not possible.</p>
<p>In this paper, we introduce a labeled data set captured at a smart factory located in Vienna, Austria, during normal operation and during penetration tests with different attack types. The data set contains 173 GB of PCAP files, representing 16 days (395 hours) of factory operation. It includes MQTT, OPC UA, and Modbus/TCP traffic.</p>
<p>The captured malicious traffic originated from a professional penetration tester who performed two types of attacks:<br>(a) Aggressive attacks that are easier to detect.<br>(b) Stealthy attacks that are harder to detect.</p>
<p>Our data set includes the raw PCAP files and extracted flow data. Labels for packets and flows indicate whether they originated from a specific attack or from benign communication. </p>
<p>We describe the methodology for creating the dataset, conduct an analysis of the data, and provide detailed information about the recorded traffic itself. The dataset is freely available to support reproducible research and the comparability of results in the area of intrusion detection in industrial networks.</p>
<p> </p>
<h3>Technical details</h3>
<ul>
<li>readme.txt
<ul>
<li>Information about the data collection, format, necessary software and versions to access it.</li>
</ul>
</li>
<li>license.txt:
<ul>
<li>Licensing information.</li>
</ul>
</li>
<li>a_day1, a_day2, s_day1, s_day2, tf_a, and tf_s:
<ul>
<li> Main dataset, where files starting with "tf" are training files containing only benign, <br> operational data. All other files are attack files containing both operational data and <br> attack data.</li>
</ul>
</li>
<li>images.zip:
<ul>
<li>Contains descriptive images about the data.</li>
</ul>
</li>
<li>extractions.zip:
<ul>
<li>Contains extracted packets and flows in both labeled and unlabeled form.</li>
</ul>
</li>
<li>a_day_tuesday_dos.zip:
<ul>
<li>An additional day of attack traffic containing benign and attack data, including a DoS attack. This day is not labeled.</li>
</ul>
</li>
<li>list_of_extracted_features:
<ul>
<li>A complete list of features we extracted from the PCAP Files. All flow files contain these features.</li>
</ul>
</li>
<li>list_of_identified_protocols.csv:
<ul>
<li>A complete list of all protocols that we could identify within the PCAP files provided.</li>
</ul>
</li>
</ul>
<div> </div>
Bone regenerating effect of surface-functionalized titanium implants with sustained-release characteristics of strontium in ovariectomized rats
No full textVincent Offermanns,1 Ole Zoffmann Andersen,2 Gregor Riede,1 Inge Hald Andersen,3 Klaus Pagh Almtoft,3 Søren Sørensen,3 Michael Sillassen,2 Christian Sloth Jeppesen,3 Michael Rasse,1 Morten Foss,2 Frank Kloss1 1Department of Cranio-, Maxillofacial and Oral Surgery, Medical University Innsbruck, Innsbruck, Austria; 2Interdisciplinary Nanoscience Center (iNANO), Faculty of Science and Technology, Aarhus University, Aarhus, Denmark; 3Tribology Centre, Danish Technological Institute, Aarhus, Denmark Abstract: Since strontium (Sr) is known for its anabolic and anticatabolic effect on bone, research has been focused on its potential impact on osseointegration. The objective of this study was to investigate the performance of nanotopographic implants with a Sr-functionalized titanium (Ti) coating (Ti–Sr–O) with respect to osseointegration in osteoporotic bone. The trial was designed to examine the effect of sustained-release characteristics of Sr in poor-quality bone. Three Ti–Sr–O groups, which differed from each other in coating thickness, Sr contents, and Sr release, were examined. These were prepared by a magnetron sputtering process and compared to uncoated grade 4 Ti. Composition, morphology, and mechanical stability of the coatings were analyzed, and Sr release data were gained from in vitro washout experiments. In vivo investigation was carried out in an osteoporotic rat model and analyzed histologically, 6 weeks and 12 weeks after implantation. Median values of bone-to-implant contact and new bone formation after 6 weeks were found to be 84.7% and 54.9% (best performing Sr group) as compared to 65.2% and 23.8% (grade 4 Ti reference), respectively. The 12-week observation period revealed 84.3% and 56.5% (best performing Sr group) and 81.3% and 39.4% (grade 4 Ti reference), respectively, for the same measurements. The increase in new bone formation was found to correlate with the amount of Sr released in vitro. The results indicate that sputtered nanostructured Ti–Sr–O coatings showed sustained release of Sr and accelerate osseointegration even in poor-quality bone, and thus, may have impact on practical applications for medical implants. Keywords: nanotopography, osteoinduction, osseointegration, osteoporosis, roden
Analysis of the Distribution of Fracture Toughness Values measured with 1T C(T) Specimens at Loading Rates higher than dK/dt=105 MPa√m s-1
No full textAbstractIn a research project investigating the correlation of dynamic crack initiation and crack arrest, funded by the German government, tests at -20 °C on specimens of 22 NiMoCr 3 7 steel (A 508 Cl.2) were performed with different specimen geometries and loading devices in the range of dK/dt=105 MPa√m s-1, Mayer (2012), Böhme et al. (2013), Mayer and Offermanns (2013). New results were obtained in the current follow-up joint IWM-MPA project in a temperature range from -20 °C to +20 °C from test series in this range of loading rates, Mayer (2015). Results from tests with 1T C(T)-specimen tested at MPA Stuttgart at loading rates higher than dK/dt=105 MPa√m s-1 are analyzed. This analysis shows the need of modifications to the standard evaluation method in ASTM E1921 if used for tests at elevated loading rates. The assumed distribution of the fracture toughness values and the form of the master curve has to be adapted and a more precise correlation of the measured reference temperature T0,X to the loading rate at fracture initiation has to be considered. Suggestions for suitable changes in the annex of ASTM E1921 for the evaluation of elevated loading rate data are presented
Deformation and Failure Mechanisms of Austenitic Piping Under the Influence of Oxyhydrogen Reactions
No full textThe present paper deals with the deformation and failure mechanisms of austenitic piping under the influence of oxyhydrogen reactions for the safety evaluation of incident scenarios in technical installations based on previous work of the author [1–5].
For the characterization of the processes, detonation tests performed at the Materials Testing Institute University of Stuttgart (MPA Stuttgart) have been used. The aim of these experiments was to study the detonation processes in head spray cooling piping of boiling water reactors. The experiments were performed on austenitic pipes with an outer diameter of O. D. = 114.3 mm and various wall thicknesses. Oxyhydrogen was used in its stoichiometric ratio of 2H2+O2 mixed with various amounts of an inert gas component. These tests have shown that less amounts of reactive gas may result in a stronger reaction of the pipe structure. This observation is attributed to the influence of the so-called overdriven detonation.
Depending on the ratio of oxyhydrogen to the inert gas component and the pipe-wall thickness, adiabatic shear bands can occur in the piping structure. Adiabatic shear bands are very narrow zones with intense localized shear deformations due to the conversion of a significant portion of strain energy into heat.
In order to describe this phenomenon numerically, a strain-based failure model was used which can reflect material damage over a wide range of different stress states. However, it has shown that damage of the studied material depends significantly on the Lode angle. Furthermore, no clear dependence of the failure limit on the loading rate has been found for the studied material.
For the constitutive description of the material behavior under the occurring loading rates and temperatures suitable material models were selected and the required parameters have been evaluated experimentally and verified by numerical methods. With the aid of this constitutive description of the material behavior and the failure model numerical simulations of the detonation tests were carried out.</jats:p
Design, synthesis and pharmacological evaluation of original nitrobenzenesulfonylureas and sulfonylcyanoguanidines as thromboxane A2 receptor antagonists/Conception, synth\ue8se et \ue9valuation pharmacologique de nitrobenz\ue8nesulfonylur\ue9es et sulfonylcyanoguanidines en tant qu'antagonistes des r\ue9cepteurs au thromboxane A2
No full textComparison of allogeneic and autogenous bone grafts for augmentation of alveolar ridge defects—A 12‐month retrospective radiographic evaluation
No full text
