TY - JOUR A1 - Baroud, G. A1 - Wu, J.Z. A1 - Bohner, M A1 - Sponagel, Stefan A1 - Steffen, T. T1 - How to determine the permeability for cement infiltration into osteoporotic cancellous bone JF - Medical Engineering & Physics. 25 (2003), H. 4 N2 - Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm4/N.s) reduced to approximately 63% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice. KW - Osteoporose KW - Permeabilität KW - Viskose Strömung KW - Viskosität KW - Vertebroplastie KW - Cement infiltration KW - Vertebroplasty KW - Osteoporosis KW - Permeability KW - Experiment KW - Analysis KW - Viscous flow Y1 - 2003 SN - 1350-4533 SP - 283 EP - 288 ER - TY - JOUR A1 - Eggert, Mathias A1 - Kling, Rene T1 - How to distribute charging requests of electronic vehicles? A reservation-based approach JF - International Journal of Intelligent Transportation Systems Research N2 - The number of electronic vehicles increase steadily while the space for extending the charging infrastructure is limited. In particular in urban areas, where parking spaces in attractive areas are famous, opportunities to setup new charging stations is very limited. This leads to an overload of some very attractive charging stations and an underutilization of less attractive ones. Against this background, the paper at hand presents the design of an e-vehicle reservation system that aims at distributing the utilization of the charging infrastructure, particularly in urban areas. By applying a design science approach, the requirements for a reservation-based utilization approach are elicited and a model for a suitable distribution approach and its instantiation are developed. The artefact is evaluated by simulating the distribution effects based on data of real charging station utilizations. KW - Simulation KW - Parking KW - Charging station KW - Utilization improvement KW - Reservation system KW - Electronic vehicle Y1 - 2023 U6 - https://doi.org/10.1007/s13177-023-00367-z SN - 1868-8659 N1 - Corresponding author: Mathias Eggert VL - 21 IS - 2023 SP - 437 EP - 460 PB - Springer CY - Berlin, Heidelberg, New York ER - TY - JOUR A1 - Klettke, Tanja A1 - Homburg, Carsten A1 - Gell, Sebastian T1 - How to measure analyst forecast effort JF - European Accounting Review N2 - We introduce a new way to measure the forecast effort that analysts devote to their earnings forecasts by measuring the analyst's general effort for all covered firms. While the commonly applied effort measure is based on analyst behaviour for one firm, our measure considers analyst behaviour for all covered firms. Our general effort measure captures additional information about analyst effort and thus can identify accurate forecasts. We emphasise the importance of investigating analyst behaviour in a larger context and argue that analysts who generally devote substantial forecast effort are also likely to devote substantial effort to a specific firm, even if this effort might not be captured by a firm-specific measure. Empirical results reveal that analysts who devote higher general forecast effort issue more accurate forecasts. Additional investigations show that analysts' career prospects improve with higher general forecast effort. Our measure improves on existing methods as it has higher explanatory power regarding differences in forecast accuracy than the commonly applied effort measure. Additionally, it can address research questions that cannot be examined with a firm-specific measure. It provides a simple but comprehensive way to identify accurate analysts. Y1 - 2015 U6 - https://doi.org/10.1080/09638180.2014.909291 SN - 0963-8180 VL - 24 IS - 1 SP - 129 EP - 146 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Dotzauer, Martin A1 - Pfeiffer, Diana A1 - Lauer, Markus A1 - Pohl, Marcel A1 - Mauky, Eric A1 - Bär, Katharina A1 - Sonnleitner, Matthias A1 - Zörner, Wilfried A1 - Hudde, Jessica A1 - Schwarz, Björn A1 - Faßauer, Burkhardt A1 - Dahmen, Markus A1 - Rieke, Christian A1 - Herbert, Johannes A1 - Thrän, Daniela T1 - How to measure flexibility – Performance indicators for demand driven power generation from biogas plants JF - Renewable Energy Y1 - 2019 U6 - https://doi.org/10.1016/j.renene.2018.10.021 SN - 0960-1481 SP - 135 EP - 146 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Görgens, Stefan A1 - Greubel, Steffen A1 - Moosdorf, Andreas T1 - How to mobilize 20,000 people: Perspectives on retail and consumer goods Y1 - 2013 SP - 52 EP - 58 ER - TY - JOUR A1 - Schuba, Marko A1 - Reichl, Peter A1 - Hoff, Simon T1 - How to Model Complex Periodic Traffic with TES / Reichl, Peter ; Schuba, Marko ; Hoff, Simon JF - Proc. of 13th United Kingdom Workshop on Performance Engineering, Edinburgh, UK, July 1997 Y1 - 1997 SP - 17/1 EP - 17/11 ER - TY - JOUR A1 - Schuba, Marko A1 - Reichl, Peter T1 - How to Place Connectionless Servers in ATM Networks / Schuba, Marko ; Reichl, Peter JF - Proc. of Fourth IFIP Workshop on Performance Modelling and Evaluation of ATM Networks Y1 - 1996 N1 - Fourth IFIP Workshop on Performance Modelling and Evaluation of ATM Networks, Ilkley, West Yorkshire, U.K., July 1996 SP - 09/1 EP - 09/10 ER - TY - JOUR A1 - Richter, Charlotte A1 - Braunstein, Bjoern A1 - Winnard, Andrew A1 - Nasser, Mona A1 - Weber, T. T1 - Human Biomechanical and Cardiopulmonary Responses to Partial Gravity – A Systematic Review JF - Frontiers in physiology Y1 - 2017 U6 - https://doi.org/10.3389/fphys.2017.00583 IS - 8, article 583 ER - TY - JOUR A1 - Ross, Jillian A1 - Plummer, Simon M. A1 - Rode, Anja A1 - Scheer, Nico A1 - Bower, Conrad C. A1 - Vogel, Ortwin A1 - Henderson, Colin J. A1 - Wolf, C. Roland A1 - Elcombe, Clifford R. T1 - Human constitutive androstane receptor (CAR) and pregnane X receptor (PXR) support the hypertrophic but not the hyperplastic response to the murine nongenotoxic hepatocarcinogens phenobarbital and chlordane in vivo JF - Toxicological Sciences N2 - Mouse nongenotoxic hepatocarcinogens phenobarbital (PB) and chlordane induce hepatomegaly characterized by hypertrophy and hyperplasia. Increased cell proliferation is implicated in the mechanism of tumor induction. The relevance of these tumors to human health is unclear. The xenoreceptors, constitutive androstane receptors (CARs), and pregnane X receptor (PXR) play key roles in these processes. Novel “humanized” and knockout models for both receptors were developed to investigate potential species differences in hepatomegaly. The effects of PB (80 mg/kg/4 days) and chlordane (10 mg/kg/4 days) were investigated in double humanized PXR and CAR (huPXR/huCAR), double knockout PXR and CAR (PXRKO/CARKO), and wild-type (WT) C57BL/6J mice. In WT mice, both compounds caused increased liver weight, hepatocellular hypertrophy, and cell proliferation. Both compounds caused alterations to a number of cell cycle genes consistent with induction of cell proliferation in WT mice. However, these gene expression changes did not occur in PXRKO/CARKO or huPXR/huCAR mice. Liver hypertrophy without hyperplasia was demonstrated in the huPXR/huCAR animals in response to both compounds. Induction of the CAR and PXR target genes, Cyp2b10 and Cyp3a11, was observed in both WT and huPXR/huCAR mouse lines following treatment with PB or chlordane. In the PXRKO/CARKO mice, neither liver growth nor induction of Cyp2b10 and Cyp3a11 was seen following PB or chlordane treatment, indicating that these effects are CAR/PXR dependent. These data suggest that the human receptors are able to support the chemically induced hypertrophic responses but not the hyperplastic (cell proliferation) responses. At this time, we cannot be certain that hCAR and hPXR when expressed in the mouse can function exactly as the genes do when they are expressed in human cells. However, all parameters investigated to date suggest that much of their functionality is maintained. Y1 - 2010 U6 - https://doi.org/10.1093/toxsci/kfq118 SN - 1096-0929 VL - 116 IS - 2 SP - 452 EP - 466 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Whitehead, Mark A1 - Öhlschläger, Peter A1 - Almajhdi, Fahad N. A1 - Alloza, Leonor A1 - Marzábal, Pablo A1 - Meyers, Ann E. A1 - Hitzeroth, Inga I. A1 - Rybicki, Edward P. T1 - Human papillomavirus (HPV) type 16 E7 protein bodies cause tumour regression in mice JF - BMC cancer Y1 - 2014 U6 - https://doi.org/10.1186/1471-2407-14-367 SN - 1471-2407 IS - 14:367 SP - 1 EP - 15 PB - BioMed Central CY - London ER -