@article{SponagelBaroudFalketal.2004, author = {Sponagel, Stefan and Baroud, Gamal and Falk, R. and Crookshank, M.}, title = {Experimental and theoretical investigation of directional permeability of human vertebral cancellous bone for cement infiltration. G. Baroud, R. Falk, M. Crookshank, S. Sponagel, T. Steffen}, series = {Journal of Biomechanics. 37 (2004), H. 2}, journal = {Journal of Biomechanics. 37 (2004), H. 2}, isbn = {0021-9290}, pages = {189 -- 196}, year = {2004}, language = {en} } @article{DigelWehlitzKayseretal.2018, author = {Digel, Ilya and Wehlitz, V. and Kayser, Peter and Figiel-Lange, A. and Bassam, Rasha and Rundstedt, F. von}, title = {Suspension depletion approach for exemption of infected Solanum jasminoides cells from pospiviroids}, series = {Plant Pathology}, volume = {67}, journal = {Plant Pathology}, number = {2}, publisher = {Wiley}, address = {Oxford}, issn = {1365-3059}, doi = {10.1111/ppa.12750}, pages = {358 -- 365}, year = {2018}, abstract = {Despite numerous studies, viroid elimination from infected plants remains a very challenging task. This study introduces for the first time a novel 'suspension depletion' approach for exemption of Solanum jasminoides plants from viroids. The proposed method implies initial establishment of suspension cultures of the infected plant cells. The suspended cells were then physically treated (mild thermotherapy, 33 °C), which presumably delayed the replication of the viroid. The viroid concentration in the treated biomass was monitored weekly using pospiviroid-specific PCR. After 10-12 weeks of continuous treatment, a sufficient decrease in viroid concentration was observed such that the infection became undetectable by PCR. The treated single cells then gave rise to microcolonies on a solid culture medium and the obtained viroid-negative clones were further promoted to regenerate into viroid-free plants. Three years of accumulated experimental data suggests feasibility, broad applicability, and good efficacy of the proposed approach.}, language = {en} } @article{StaatBaroudTopcuetal.2008, author = {Staat, Manfred and Baroud, Gamal and Topcu, M. and Sponagel, Stefan}, title = {Soft Materials in Technology and Biology - Characteristics, Properties, and Parameter Identification}, series = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)}, journal = {Bioengineering in Cell and Tissue Research / Artmann, Gerhard M. ; Chien, Shu (Eds.)}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-540-75408-4}, pages = {253 -- 315}, year = {2008}, language = {en} } @article{TemizArtmannYalcinResmietal.2002, author = {Temiz Artmann, Ayseg{\"u}l and Yalcin, Ozlem and Resmi, Halil and Ba{\c{s}}kurt, Oǧuz Kerim}, title = {Can white blood cell activation be one of the major factors that affect hemorheological parameters during and after exercise?}, series = {Clinical Hemorheology and Microcirculation. 26 (2002), H. 3}, journal = {Clinical Hemorheology and Microcirculation. 26 (2002), H. 3}, isbn = {1386-0291}, pages = {189 -- 193}, year = {2002}, language = {en} } @article{SponagelBaroudFalketal.2004, author = {Sponagel, Stefan and Baroud, Gamal and Falk, R. and Crookshank, M.}, title = {Corrigendum to "Experimental and theoretical investigation of directional permeability of human vertebral cancellous bone for cement infiltration". Baroud, G.; Falk, R.; Crookshank, M.; Sponagel, S.; Steffen, T.}, series = {Journal of Biomechanics. 37 (2004), H. 2}, journal = {Journal of Biomechanics. 37 (2004), H. 2}, isbn = {0021-9290}, pages = {1802}, year = {2004}, language = {en} } @article{SponagelBaroudSteffenetal.2002, author = {Sponagel, Stefan and Baroud, Gamal and Steffen, T. and Wu, J.}, title = {Parameter identification for cement infiltration of osteoporotic bone}, series = {Poromechanics II : Proceedings of the Second Biot Conference on Poromechanics Grenoble, France 26 - 28 August 2002 / ed. by J.-L. Auriault ...}, journal = {Poromechanics II : Proceedings of the Second Biot Conference on Poromechanics Grenoble, France 26 - 28 August 2002 / ed. by J.-L. Auriault ...}, publisher = {Balkema}, address = {Lisse [u.a.]}, isbn = {90-5809-394-8}, pages = {55 -- 58}, year = {2002}, language = {en} } @article{ScholzLeyDachwaldetal.2010, author = {Scholz, A. and Ley, Wilfried and Dachwald, Bernd and Miau, J. J. and Juang, J. C.}, title = {Flight results of the COMPASS-1 picosatellite mission}, series = {Acta Astronautica}, volume = {76}, journal = {Acta Astronautica}, number = {9-10}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0094-5765}, doi = {10.1016/j.actaastro.2010.06.040}, pages = {1289 -- 1298}, year = {2010}, abstract = {The mission of the COMPASS-1 picosatellite is to take pictures of the earth, to validate a space-borne GPS receiver developed by the German Aerospace Center, and to verify the proper operation of the magnetic attitude control system in orbit. The spacecraft was launched on April 28, 2008 from the Indian space port Sriharikota, as part of the PSLV-C9 world record launch that simultaneously brought ten satellites into orbit. The mission operations were carried out from the ground stations in Aachen and Tainan. Arising difficulties in the communication link were overcome with the support of individuals from the amateur radio community. After several months of mission operation, abundant housekeeping and mission data has been commanded, received and analyzed and is presented in this paper.}, language = {en} } @article{OrtnerHauserSchmadereretal.2019, author = {Ortner, Marion and Hauser, Christine and Schmaderer, Christoph and Muggenthaler, Claudia and Hapfelmeier, Alexander and Sorg, Christian and Diehl-Schmid, Janine and Kurz, Alexander and F{\"o}rstl, Hans and Ikenberg, Benno and Kotliar, Konstantin and Holger, Poppert and Grimmer, Timo}, title = {Decreased vascular pulsatility in Alzheimer's disease dementia measured by transcranial color-coded duplex sonography}, series = {Neuropsychiatric disease and treatment}, journal = {Neuropsychiatric disease and treatment}, number = {15}, publisher = {Dove Medical Press}, address = {Albany, Auckland}, issn = {1178-2021}, doi = {10.2147/NDT.S225754}, pages = {3487 -- 3499}, year = {2019}, abstract = {Purpose: Impaired paravascular drainage of β-Amyloid (Aβ) has been proposed as a contributing cause for sporadic Alzheimer's disease (AD), as decreased cerebral blood vessel pulsatility and subsequently reduced propulsion in this pathway could lead to the accumulation and deposition of Aβ in the brain. Therefore, we hypothesized that there is an increased impairment in pulsatility across AD spectrum. Patients and Methods: Using transcranial color-coded duplex sonography (TCCS) the resistance and pulsatility index (RI; PI) of the middle cerebral artery (MCA) in healthy controls (HC, n=14) and patients with AD dementia (ADD, n=12) were measured. In a second step, we extended the sample by adding patients with mild cognitive impairment (MCI) stratified by the presence (MCI-AD, n=8) or absence of biomarkers (MCI-nonAD, n=8) indicative for underlying AD pathology, and compared RI and PI across the groups. To control for atherosclerosis as a confounder, we measured the arteriolar-venular-ratio of retinal vessels. Results: Left and right RI (p=0.020; p=0.027) and left PI (p=0.034) differed between HC and ADD controlled for atherosclerosis with AUCs of 0.776, 0.763, and 0.718, respectively. The RI and PI of MCI-AD tended towards ADD, of MCI-nonAD towards HC, respectively. RIs and PIs were associated with disease severity (p=0.010, p=0.023). Conclusion: Our results strengthen the hypothesis that impaired pulsatility could cause impaired amyloid clearance from the brain and thereby might contribute to the development of AD. However, further studies considering other factors possibly influencing amyloid clearance as well as larger sample sizes are needed.}, language = {en} } @article{BandlitzNakhoulKotliar2022, author = {Bandlitz, Stefan and Nakhoul, Makram and Kotliar, Konstantin}, title = {Daily variations of corneal white-to-white diameter measured with different methods}, series = {Clinical and experimental optometry}, journal = {Clinical and experimental optometry}, number = {14}, publisher = {Taylor \& Francis}, address = {London}, issn = {0816-4622}, doi = {10.2147/OPTO.S360651}, pages = {173 -- 181}, year = {2022}, abstract = {Purpose: A precise determination of the corneal diameter is essential for the diagnosis of various ocular diseases, cataract and refractive surgery as well as for the selection and fitting of contact lenses. The aim of this study was to investigate the agreement between two automatic and one manual method for corneal diameter determination and to evaluate possible diurnal variations in corneal diameter. Patients and Methods: Horizontal white-to-white corneal diameter of 20 volunteers was measured at three different fixed times of a day with three methods: Scheimpflug method (Pentacam HR, Oculus), placido based topography (Keratograph 5M, Oculus) and manual method using an image analysis software at a slitlamp (BQ900, Haag-Streit). Results: The two-factorial analysis of variance could not show a significant effect of the different instruments (p = 0.117), the different time points (p = 0.506) and the interaction between instrument and time point (p = 0.182). Very good repeatability (intraclass correlation coefficient ICC, quartile coefficient of dispersion QCD) was found for all three devices. However, manual slitlamp measurements showed a higher QCD than the automatic measurements with the Keratograph 5M and the Pentacam HR at all measurement times. Conclusion: The manual and automated methods used in the study to determine corneal diameter showed good agreement and repeatability. No significant diurnal variations of corneal diameter were observed during the period of time studied.}, language = {en} } @inproceedings{DachwaldXuFeldmannetal.2011, author = {Dachwald, Bernd and Xu, Changsheng and Feldmann, Marco and Plescher, Engelbert and Digel, Ilya and Artmann, Gerhard}, title = {Development and testing of a subsurface probe for detection of life in deep ice : [abstract]}, year = {2011}, abstract = {We present the novel concept of a combined drilling and melting probe for subsurface ice research. This probe, named "IceMole", is currently developed, built, and tested at the FH Aachen University of Applied Sciences' Astronautical Laboratory. Here, we describe its first prototype design and report the results of its field tests on the Swiss Morteratsch glacier. Although the IceMole design is currently adapted to terrestrial glaciers and ice shields, it may later be modified for the subsurface in-situ investigation of extraterrestrial ice, e.g., on Mars, Europa, and Enceladus. If life exists on those bodies, it may be present in the ice (as life can also be found in the deep ice of Earth).}, subject = {Eisschicht}, language = {en} } @article{DachwaldMikuckiTulaczyketal.2014, author = {Dachwald, Bernd and Mikucki, Jill and Tulaczyk, Slawek and Digel, Ilya and Espe, Clemens and Feldmann, Marco and Francke, Gero and Kowalski, Julia and Xu, Changsheng}, title = {IceMole : A maneuverable probe for clean in situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems}, series = {Annals of Glaciology}, volume = {55}, journal = {Annals of Glaciology}, number = {65}, publisher = {Cambridge University Press}, address = {Cambridge}, issn = {1727-5644}, doi = {10.3189/2014AoG65A004}, pages = {14 -- 22}, year = {2014}, abstract = {There is significant interest in sampling subglacial environments for geobiological studies, but they are difficult to access. Existing ice-drilling technologies make it cumbersome to maintain microbiologically clean access for sample acquisition and environmental stewardship of potentially fragile subglacial aquatic ecosystems. The IceMole is a maneuverable subsurface ice probe for clean in situ analysis and sampling of glacial ice and subglacial materials. The design is based on the novel concept of combining melting and mechanical propulsion. It can change melting direction by differential heating of the melting head and optional side-wall heaters. The first two prototypes were successfully tested between 2010 and 2012 on glaciers in Switzerland and Iceland. They demonstrated downward, horizontal and upward melting, as well as curve driving and dirt layer penetration. A more advanced probe is currently under development as part of the Enceladus Explorer (EnEx) project. It offers systems for obstacle avoidance, target detection, and navigation in ice. For the EnEx-IceMole, we will pay particular attention to clean protocols for the sampling of subglacial materials for biogeochemical analysis. We plan to use this probe for clean access into a unique subglacial aquatic environment at Blood Falls, Antarctica, with return of a subglacial brine sample.}, language = {en} } @article{StaatSponagelNguyen2010, author = {Staat, Manfred and Sponagel, Stefan and Nguyen, Nhu Huynh}, title = {Experiment and material model for soft tissue materials}, series = {Constitutive models for rubber VI}, journal = {Constitutive models for rubber VI}, publisher = {Taylor \& Francis}, address = {London}, isbn = {9780429206597 (eBook)}, doi = {10.1201/NOE0415563277-90}, pages = {6 Seiten}, year = {2010}, abstract = {Biomechanics studies biological soft tissue materials (growth, remodeling) in vivo. For this objective, the detailed information of material properties must be well defined to construct reliable constitutive models. In the paper, the bulge test is carried out with elastomers in order to develop a test method. Then, application of the test for soft tissue materials is straightforward due to the similarities between elastomers with soft tissue materials as proved in Holzapfel 2005, Ogden 2009. It means, after the preliminary experiments and parameter identification with rubber materials has been setup, experiments on soft tissue materials can be similarly carried out. Elastomers have a complex behavior which strongly depends on the largest previous load cycle. For simplicity we consider only the first loading.}, language = {en} } @article{MurganBeyerKotliaretal.2013, author = {Murgan, Ilina and Beyer, Sonja and Kotliar, Konstantin and Weber, Lutz and Bechtold-Dalla Pozza, Susanne and Dalla Pozza, Robert and Wegner, Aharon and Sitnikova, Diana and Stock, Konrad and Heemann, Uwe and Schmaderer, Christoph and Baumann, Marcus}, title = {Arterial and Retinal Vascular Changes in Hypertensive and Prehypertensive Adolescents}, series = {American Journal of Hypertension}, volume = {26}, journal = {American Journal of Hypertension}, number = {3}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1941-7225}, pages = {400 -- 408}, year = {2013}, language = {de} } @techreport{BlandfordDachwaldDigeletal.2015, author = {Blandford, Daniel and Dachwald, Bernd and Digel, Ilya and Espe, Clemens and Feldmann, Marco and Francke, Gero and Hiecke, Hannah and Kowalski, Julia and Lindner, Peter and Plescher, Engelbert and Sch{\"o}ngarth, Sarah}, title = {Enceladus Explorer : Schlussbericht — Version: 1.0}, publisher = {FH Aachen}, address = {Aachen}, doi = {10.2314/GBV:86319950X}, year = {2015}, language = {de} } @article{KotliarHanssenEberhardtetal.2013, author = {Kotliar, Konstantin and Hanssen, Henner and Eberhardt, Karla and Vilser, Walthard and Schmaderer, Christoph and Halle, Martin and Heemann, Uwe and Baumann, Marcus}, title = {Retinal pulse wave velocity in young male normotensive and mildly hypertensive subjects}, series = {Microcirculation}, journal = {Microcirculation}, publisher = {Wiley}, address = {Malden}, issn = {1549-8719}, year = {2013}, language = {en} } @article{KowalskiLinderZierkeetal.2016, author = {Kowalski, Julia and Linder, Peter and Zierke, S. and Wulfen, B. van and Clemens, J. and Konstantinidis, K. and Ameres, G. and Hoffmann, R. and Mikucki, J. and Tulaczyk, S. and Funke, O. and Blandfort, D. and Espe, Clemens and Feldmann, Marco and Francke, Gero and Hiecker, S. and Plescher, Engelbert and Sch{\"o}ngarth, Sarah and Dachwald, Bernd and Digel, Ilya and Artmann, Gerhard and Eliseev, D. and Heinen, D. and Scholz, F. and Wiebusch, C. and Macht, S. and Bestmann, U. and Reineking, T. and Zetzsche, C. and Schill, K. and F{\"o}rstner, R. and Niedermeier, H. and Szumski, A. and Eissfeller, B. and Naumann, U. and Helbing, K.}, title = {Navigation technology for exploration of glacier ice with maneuverable melting probes}, series = {Cold Regions Science and Technology}, journal = {Cold Regions Science and Technology}, number = {123}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0165-232X}, doi = {10.1016/j.coldregions.2015.11.006}, pages = {53 -- 70}, year = {2016}, abstract = {The Saturnian moon Enceladus with its extensive water bodies underneath a thick ice sheet cover is a potential candidate for extraterrestrial life. Direct exploration of such extraterrestrial aquatic ecosystems requires advanced access and sampling technologies with a high level of autonomy. A new technological approach has been developed as part of the collaborative research project Enceladus Explorer (EnEx). The concept is based upon a minimally invasive melting probe called the IceMole. The force-regulated, heater-controlled IceMole is able to travel along a curved trajectory as well as upwards. Hence, it allows maneuvers which may be necessary for obstacle avoidance or target selection. Maneuverability, however, necessitates a sophisticated on-board navigation system capable of autonomous operations. The development of such a navigational system has been the focal part of the EnEx project. The original IceMole has been further developed to include relative positioning based on in-ice attitude determination, acoustic positioning, ultrasonic obstacle and target detection integrated through a high-level sensor fusion. This paper describes the EnEx technology and discusses implications for an actual extraterrestrial mission concept.}, language = {en} } @inproceedings{DupratDachwaldHilchenbachetal.2013, author = {Duprat, J. and Dachwald, Bernd and Hilchenbach, M. and Engrand, Cecile and Espe, C. and Feldmann, Marco and Francke, Gero and G{\"o}r{\"o}g, Mark and L{\"u}sing, N. and Langenhorst, Falko}, title = {The MARVIN project: a micrometeorite harvester in Antarctic snow}, series = {44th Lunar and Planetary Science Conference}, booktitle = {44th Lunar and Planetary Science Conference}, year = {2013}, abstract = {MARVIN is an automated drilling and melting probe dedicated to collect pristine interplanetary dust particles (micrometeorites) from central Antarctica snow.}, language = {en} } @inproceedings{DachwaldMikuckiTulaczyketal.2012, author = {Dachwald, Bernd and Mikucki, Jill A. and Tulaczyk, Slawek and Digel, Ilya and Feldmann, Marco and Espe, Clemens and Plescher, Engelbert and Xu, Changsheng}, title = {IceMole - a maneuverable probe for clean in-situ analysis and sampling of subsurface ice and subglacial aquatic ecosystems : extended abstract / SCAR Open Science Conference 2012, Session 29: Advancing Clean Technologies for Exploration of Glacial Aquatic Ecosystems}, year = {2012}, abstract = {The "IceMole" is a novel maneuverable subsurface ice probe for clean in-situ analysis and sampling of subsurface ice and subglacial water/brine. It is developed and build at FH Aachen University of Applied Sciences' Astronautical Laboratory. A first prototype was successfully tested on the Swiss Morteratsch glacier in 2010. Clean sampling is achieved with a hollow ice screw (as it is used in mountaineering) at the tip of the probe. Maneuverability is achieved with a differentially heated melting head. Funded by the German Space Agency (DLR), a consortium led by FH Aachen currently develops a much more advanced IceMole probe, which includes a sophisticated system for obstacle avoidance, target detection, and navigation in the ice. We intend to use this probe for taking clean samples of subglacial brine at the Blood Falls (McMurdo Dry Valleys, East Antarctica) for chemical and microbiological analysis. In our conference contribution, we 1) describe the IceMole design, 2) report the results of the field tests of the first prototype on the Morteratsch glacier, 3) discuss the probe's potential for the clean in-situ analysis and sampling of subsurface ice and subglacial liquids, and 4) outline the way ahead in the development of this technology.}, subject = {Eisschicht}, language = {en} } @article{MikuckiSchulerDigeletal.2023, author = {Mikucki, Jill Ann and Schuler, C. G. and Digel, Ilya and Kowalski, Julia and Tuttle, M. J. and Chua, Michelle and Davis, R. and Purcell, Alicia and Ghosh, D. and Francke, G. and Feldmann, Marco and Espe, C. and Heinen, Dirk and Dachwald, Bernd and Clemens, Joachim and Lyons, W. B. and Tulaczyk, S.}, title = {Field-Based planetary protection operations for melt probes: validation of clean access into the blood falls, antarctica, englacial ecosystem}, series = {Astrobiology}, volume = {23}, journal = {Astrobiology}, number = {11}, publisher = {Liebert}, address = {New York, NY}, issn = {1557-8070 (online)}, doi = {10.1089/ast.2021.0102}, pages = {1165 -- 1178}, year = {2023}, abstract = {Subglacial environments on Earth offer important analogs to Ocean World targets in our solar system. These unique microbial ecosystems remain understudied due to the challenges of access through thick glacial ice (tens to hundreds of meters). Additionally, sub-ice collections must be conducted in a clean manner to ensure sample integrity for downstream microbiological and geochemical analyses. We describe the field-based cleaning of a melt probe that was used to collect brine samples from within a glacier conduit at Blood Falls, Antarctica, for geomicrobiological studies. We used a thermoelectric melting probe called the IceMole that was designed to be minimally invasive in that the logistical requirements in support of drilling operations were small and the probe could be cleaned, even in a remote field setting, so as to minimize potential contamination. In our study, the exterior bioburden on the IceMole was reduced to levels measured in most clean rooms, and below that of the ice surrounding our sampling target. Potential microbial contaminants were identified during the cleaning process; however, very few were detected in the final englacial sample collected with the IceMole and were present in extremely low abundances (∼0.063\% of 16S rRNA gene amplicon sequences). This cleaning protocol can help minimize contamination when working in remote field locations, support microbiological sampling of terrestrial subglacial environments using melting probes, and help inform planetary protection challenges for Ocean World analog mission concepts.}, language = {en} } @article{GermanMikuckiWelchetal.2021, author = {German, Laura and Mikucki, Jill A. and Welch, Susan A. and Welch, Kathleen A. and Lutton, Anthony and Dachwald, Bernd and Kowalski, Julia and Heinen, Dirk and Feldmann, Marco and Francke, Gero and Espe, Clemens and Lyons, W. Berry}, title = {Validation of sampling antarctic subglacial hypersaline waters with an electrothermal ice melting probe (IceMole) for environmental analytical geochemistry}, series = {International Journal of Environmental Analytical Chemistry}, volume = {101}, journal = {International Journal of Environmental Analytical Chemistry}, number = {15}, publisher = {Taylor \& Francis}, address = {London}, issn = {0306-7319}, doi = {10.1080/03067319.2019.1704750}, pages = {2654 -- 2667}, year = {2021}, abstract = {Geochemical characterisation of hypersaline waters is difficult as high concentrations of salts hinder the analysis of constituents at low concentrations, such as trace metals, and the collection of samples for trace metal analysis in natural waters can be easily contaminated. This is particularly the case if samples are collected by non-conventional techniques such as those required for aquatic subglacial environments. In this paper we present the first analysis of a subglacial brine from Taylor Valley, (~ 78°S), Antarctica for the trace metals: Ba, Co, Mo, Rb, Sr, V, and U. Samples were collected englacially using an electrothermal melting probe called the IceMole. This probe uses differential heating of a copper head as well as the probe's sidewalls and an ice screw at the melting head to move through glacier ice. Detailed blanks, meltwater, and subglacial brine samples were collected to evaluate the impact of the IceMole and the borehole pump, the melting and collection process, filtration, and storage on the geochemistry of the samples collected by this device. Comparisons between melt water profiles through the glacier ice and blank analysis, with published studies on ice geochemistry, suggest the potential for minor contributions of some species Rb, As, Co, Mn, Ni, NH4+, and NO2-+NO3- from the IceMole. The ability to conduct detailed chemical analyses of subglacial fluids collected with melting probes is critical for the future exploration of the hundreds of deep subglacial lakes in Antarctica.}, language = {en} }