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1. Systematic Review and Meta-Analysis on Colorectal Anastomotic Techniques

Author

Steger J, Jell A, Ficht S, Ostler D, Eblenkamp M, Mela P, and Wilhelm D

Subjects
anastomotic technique, postoperative complications, ideal anastomosis, intraoperative trauma, Therapeutics. Pharmacology, RM1-950
Abstract

Jana Steger,1 Alissa Jell,1,2 Stefanie Ficht,3 Daniel Ostler,1 Markus Eblenkamp,3 Petra Mela,3 Dirk Wilhelm1,2 1Technical University of Munich, TUM School of Medicine, Chair of Research Group Minimally Invasive Interdisciplinary Therapeutical Intervention (MITI), Munich, Germany; 2Technical University of Munich, TUM School of Medicine, Clinic and Polyclinic for Surgery, Munich, Germany; 3Technical University of Munich, TUM School of Engineering and Design, Department of Mechanical Engineering and Munich Institute of Biomedical Engineering, Chair of Medical Materials and Implants, Garching, GermanyCorrespondence: Jana Steger, Tel +49 89 4140-5898, Email jana.steger@tum.dePurpose: Anastomosis creation after resective gastrointestinal surgery is a crucial task. The present review examines the techniques and implants currently available for anastomosis creation and analyses to which extent they already address our clinical needs, with a special focus on their potential to enable further trauma minimization in visceral surgery.Methods: A multi-database research was conducted in MEDLINE, Scopus, and Cochrane Library. Comparative controlled and uncontrolled clinical trials dealing with anastomosis creation techniques in the intestinal tract in both German and English were included and statistically significant differences in postoperative complication incidences were assessed using the RevMan5.4 Review Manager (Cochrane Collaboration, Oxford, UK).Results: All methods and implant types were analyzed and compared with respect to four dimensions, assessing the techniques’ current performances and further potentials for surgical trauma reduction. Postoperative outcome measures, such as leakage, stenosis, reoperation and mortality rates, as well as the tendency to cause bleeding, wound infections, abscesses, anastomotic hemorrhages, pulmonary embolisms, and fistulas were assessed, revealing the only statistically significant superiority of hand-suture over stapling anastomoses with respect to the occurrence of obstructions.Conclusion: Based on the overall complication rates, it is concluded that none of the anastomosis systems addresses the demands of operative trauma minimization sufficiently yet. Major problems are furthermore either low standardization potentials due to dependence on the surgeons’ levels of experience, high force application requirements for the actual anastomosis creation, or large and rigid device designs interfering with flexibility demands and size restrictions of the body’s natural access routes. There is still a need for innovative technologies, especially with regard to enabling incisionless interventions.Keywords: anastomotic technique, postoperative complications, ideal anastomosis, intraoperative trauma

Published
2022

8. Understanding and predicting ciprofloxacin minimum inhibitory concentration in Escherichia coli with machine learning

Author

Pataki B. A., Matamoros S., van der Putten B. C. L., Remondini D., Giampieri E., Aytan-Aktug D., Hendriksen R. S., Lund O., Csabai I., Schultsz C., Janes V., Clausen P., Aarestrup F. M., Koopmans M., Pataki B., Visontai D., Steger J., Szalai-Gindl J. M., Pakseresht N., Rossello M., Silvester N., Amid C., Cochrane G., Pradel F., Westeel E., Fuchs S., Kumar S. M., Xavier B. B., Ngoc M. N., Pasquali F., Petrovska L., Ajayi D., Nielsen E. M., Trung N. V., Hoa N. T., Ishii Y., Aoki K., McDermott P., Virology, Pataki B.A., Matamoros S., van der Putten B.C.L., Remondini D., Giampieri E., Aytan-Aktug D., Hendriksen R.S., Lund O., Csabai I., Schultsz C., Janes V., Clausen P., Aarestrup F.M., Koopmans M., Pataki B., Visontai D., Steger J., Szalai-Gindl J.M., Pakseresht N., Rossello M., Silvester N., Amid C., Cochrane G., Pradel F., Westeel E., Fuchs S., Kumar S.M., Xavier B.B., Ngoc M.N., Pasquali F., Petrovska L., Ajayi D., Nielsen E.M., Trung N.V., Hoa N.T., Ishii Y., Aoki K., McDermott P., Medical Microbiology and Infection Prevention, Global Health, AII - Infectious diseases, Graduate School, and APH - Global Health

Subjects
0301 basic medicine, Antibiotics, lcsh:Medicine, computer.software_genre, medicine.disease_cause, DNA gyrase, Genome, Machine Learning, Ciprofloxacin, Escherichia coli Protein, lcsh:Science, 0303 health sciences, Multidisciplinary, Phylogenetic tree, Escherichia coli Proteins, Intracellular Signaling Peptides and Proteins, Anti-Bacterial Agents, 3. Good health, DNA Gyrase, Mutation (genetic algorithm), medicine.drug, FASTQ format, medicine.drug_class, 030106 microbiology, Biology, Machine learning, Microbiology, DNA sequencing, Article, Inhibitory Concentration 50, 03 medical and health sciences, Minimum inhibitory concentration, Antibiotic resistance, Toxicity Tests, Anti-Bacterial Agent, Drug Resistance, Bacterial, Escherichia coli, medicine, 030304 developmental biology, Whole genome sequencing, Molecular epidemiology, 030306 microbiology, business.industry, lcsh:R, Computational biology and bioinformatics, Toxicity Test, 030104 developmental biology, Intracellular Signaling Peptides and Protein, Genes, Bacterial, Mutation, lcsh:Q, Artificial intelligence, business, computer
Abstract

2.AbstractA possible way to tackle the crisis of antimicrobial resistance development is a strict policy when prescribing antibiotics. Thus, it is important that prescriptions are based on antimicrobial susceptibility data to ensure effective treatment outcomes. The increasing availability of next-generation sequencing (NGS), bacterial whole genome sequencing (WGS) can facilitate a more reliable and faster alternative to traditional phenotyping for the detection and surveillance of AMR.This work proposes a machine learning approach that can predict the minimum inhibitory concentration (MIC) for a given antibiotic, here ciprofloxacin, on the basis of both genome-wide mutation profiles and profiles of acquired antimicrobial resistance genes (ARG). We analysed 704 Escherichia coli genomes combined with their respective MIC measurements for ciprofloxacin originating from different countries. The four most important predictors found by the model, mutations in gyrA residues Ser83 and Asp87, a mutation in parC residue Ser80 and presence of any qnrS gene, have been experimentally validated before. Using only these four predictors in a linear regression model, 65% and 92% of the test samples’ MIC were correctly predicted within a two- and a four-fold dilution range, respectively. The presented work goes further than the typical predictions that use machine learning as a black box model concept. The recent progress in WGS technology in combination with machine learning analysis approaches indicates that in the near future WGS of bacteria might become cheaper and faster than a MIC measurement.3.Impact statementWhole genome sequencing has become the standard approach to study molecular epidemiology of bacteria. However, the application of WGS in the clinical microbiology laboratory as part of individual patient diagnostics still requires significant steps forward, in particular with respect to prediction of antibiotic susceptibility based on DNA sequence. Whilst the majority of studies of prediction of susceptibility have used a binary outcome (susceptible/resistant), a quantitative prediction of susceptibility, such as the MIC, will allow for earlier detection of trends in increasing resistance as well as the flexibility to follow potential adjustments in definitions of susceptible (wild type) and resistant (non-wild type) categories (breakpoints/ epidemiological cut-off values).4.Data summaryIn this study, 704 E. coli genomes combined with MIC measurement for ciprofloxacin were analysed (24). Paired-end sequencing was performed on all isolates and the results were stored in FASTQ format. The isolates originated from five countries, Denmark, Italy, USA, UK, and Vietnam. The MIC distribution for these isolates is depicted in Table 1. Out of 704, 266 E. coli genomes had no country metadata available and were used as an independent test set. All data were deposited in the AMR Data Hub (24) which consists of raw sequencing data, ciprofloxacin minimum inhibitory concentrations, and additional metadata such as the origin of the samples.TABLE 1The collected and used data in the analysis grouped by country and MIC values.Publicly available sequencing data was used from projects PRJEB21131, PRJNA266657, PRJNA292901, PRJNA292904, PRJNA292902, PRJDB7087, PRJEB21880, PRJEB21997, PRJEB14086 and PRJEB16326.Download and analysis scripts are available at https://github.com/patbaa/AMR_ciprofloxacin. iTOL phylogenetic tree is available at https://itol.embl.de/tree/14511722611491391569485969.The authors confirm all supporting data, code and protocols have been provided within the article or through supplementary data files.

Published
2019
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12. Training and education of young physicians and engineers in the field of endoscopy and laparoscopy – a review of Germany-wide joint cooperation and training possibilities

Author

Wichmann Dörte, Duckwort-Mothes Benedikt, Hirt Bernhard, Wilhelm Dirk, Steger Jana, Zweimüller Martin, Küllmer Armin, Raithel Martin, Maiss Jürgen, Pott Peter, and Wittenberg Thomas

Subjects
endoscopy, laparoscopy, education, hands-on training, interdisciplinary cooperation, Medicine
Abstract

Introduction: Application-related (hands-on) training and instruction is an essential component in the advanced education of physicians in residency. To teach and train required endoscopic examinations and interventions in a standardized manner, courses are offered by various societies. Within these courses the assistant endoscopists learn and train how to use the technical equipment and how to perform the examinations and related interventions. Similarly, for graduate biomedical engineering students with a job- or research-related interest in the field of endoand laparoscopy, an early involvement and practical introduction to the instrumentation and techniques - if possible already during their studies - can generate a fundamental understanding of the technical requirements as well needs of the physicians. Objective: As various such (hands-on) training-courses for flexible and rigid endoscopy specifically addressing young physicians, surgeons as well as engineers are offered by numerous institutes, this contribution tries do provide a structured overview on/over these possibilities. Material: Known cross-institutional courses in the field of endo- and laparoscopy currently offered in Germany in cooperation of physicians and engineers are listed and briefly described. Results: A total of n = 4 crossinstitutional courses for the introduction and training in flexible and rigid endoscopy have been identified. Discussion: The cross-institutional courses for physicians and technicians in the field of endo- and laparoscopy presented serve to provide a better understanding of the subject matter and the field of either discipline. Questions that arise in the field of endoscopy from physicians can be addressed at an early stage and, if necessary, worked on with little effort. Ideas for new instruments and even new interventions can arise and be pursued through an intensive exchange between technicians and physicians. Collaborations are established on a local basis which will foster national activities in this field and which allow to develop competencies relevant for the industrial sector of medical engineering.

Published
2023
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13. The decline of native molluscs on the Israeli shallow shelf

Author

Albano, Paolo.G., Steger, J., Bošnjak, M., Dunne, B., Guifarro, Z., Hinterplattner, A., Galil, B., and Zuschin, M

Subjects
molluscs, shelf, Mediterranean Sea, Israel
Abstract

The Levantine basin in the eastern-most Mediterranean Sea hosts hundreds of non- indigenous species introduced after the opening of the Suez Canal. An equally dramatic phenomenon is the disappearance of native molluscs. Here we quan-tify this decline on the IsraeliMediterranean soft-substrate shelf based on samplingalong two transects off northern and southern Israel in Autumn 2016 and Spring 2017 at 10-40 mdepth. We compared the living assemblages with 1) a comprehensive literature- based checklist of Israelimolluscs filtered by appropriate substrate and depth, and 2) the compo-sition of the death-assemblagecollected with the living organisms. We used a smallmesh size (0.5 mm) to retain small sized and juvenile individuals and deployed an intense identificationeffort, including tracing the morphology of early post-larval stages. Our sampling intercepted only 24% of the historically recorded species, notwithstanding a sample coverage of 99.4%. At individual sites, the living assemblage native richness is between 2.9%and 18.5% of the death assemblage native richness.By contrast, we intercepted 54% of the his-torically recorded non-indigenous species. At individualsites, the living assemblage non- indigenous richnessranges between 7.1% and 80.2% (mean 42%) of the death assem-blage, with lower values in deeperstations. The abundance of native species peaks in spring (80%, 934 individuals) but drops in autumn to only 15% (279 individuals, not-withstanding that two additional replicates were collected) suggesting a mass mortality during summer. The comparison of size-frequency distributions from living and death assemblages showed that most native species are represented by small living individuals that do not reach the large sizes of the past, suggesting that while recruit-ment does occur, death occurs prematurely, for some species possibly before maturity. By contrast, for most non- indigenousspecies the size range of living individuals overlapswith the dead ones. These two results combinedsuggest that current environmental conditions(likely including the locally rapid climate warming) disproportionally favour non-indigenous species andthat native species reproduction may be hindered, with recruitment potentially coming from deeperwaters or other sectors of the basin.

Published
2019

14. Worldwide human mitochondrial haplogroup distribution from urban sewage

Author

Pipek, OA, Medgyes-Horvath, A, Dobos, L, Steger, J, Szalai-Gindl, J, Visontai, D, Kaas, RS, Koopmans, Marion, Hendriksen, RS, Aarestrup, FM, Csabai, I, Pipek, OA, Medgyes-Horvath, A, Dobos, L, Steger, J, Szalai-Gindl, J, Visontai, D, Kaas, RS, Koopmans, Marion, Hendriksen, RS, Aarestrup, FM, and Csabai, I

Published
2019

18. Ozone Loss in the Arctic Stratosphere as Observed by Match

Author

Rex, M, von der Gathen, P, Schulz, A, Steger, J, Gernandt, H, Harris, N, Reimen, E, Bech, A, Alfier, A, Chippertield, M, Kilbane-Dawe, I, Allart, M, Alpers, M, De Bacher, H, Balis, D, Bojkou, B, Brahthen, G, Cisneros, J, and Clandeetar, H

Subjects
Geophysics
Abstract

We present box model calculations of ozone loss rates corresponding to the results of the Match experiment 1991/92.

Published
1999

19. Reduction of Eyedrop Volume for Topical Ophthalmic Medications with the Nanodropper Bottle Adaptor

Author

St. Peter DM, Steger JS, Patnaik JL, Davis N, Kahook MY, and Seibold LK

Subjects
ophthalmic medication, medication delivery, dry eye syndrome, glaucoma medications, medication adherence, drop assist devices, Medical technology, R855-855.5
Abstract

Deidre M St. Peter,1 Jennifer S Steger,2 Jennifer L Patnaik,1 Nicole Davis,1 Malik Y Kahook,1 Leonard K Seibold1 1Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, USA; 2Nanodropper, Inc, Rochester, MN, USACorrespondence: Leonard K Seibold, Department of Ophthalmology, University of Colorado School of Medicine, 1675 Aurora Court, Aurora, CO, 80045, USA, Tel +1 720-848-2020, Fax +1 720-848-5079, Email Leonard.seibold@cuanschutz.eduPurpose: To determine the drop volume and total number of dispensed drops using the Nanodropper eyedrop bottle adaptor (Nanodropper, Inc.) compared to drops dispensed from stock bottles to potentially limit ocular toxicity of these eyedrops and prolong bottle use.Patients and Methods: Six topical ocular hypotensive medications (5 solutions, 1 suspension), one steroid (suspension) and two artificial tears emulsions were selected for this study. An analytical balance was used to determine the mass per 10 drops with and without the volume-reducing adaptor and repeated until the bottles were completely emptied. The density of each product was determined using the calculated density. The average drop volume and number of drops per bottle for the nine medications were compared with and without the adaptor with paired t-testing.Results: When all medications were assessed, the drops delivered with the adaptor were 62.1% smaller than eyedrops administered from standard bottles. Compared to stock bottle eyedrops, which had a mean volume of 39.8 ± 2.1 μL, the adaptor resulted in drops with a mean volume of 15.1 ± 1.0 μL, p< 0.0001. The adaptor delivered 2.6x the number of drops dispensed from a standard 2.5 mL bottle (184.1 ± 15.1 drops with adaptor and 69.8 ± 4.9 drops from stock bottle, p< 0.0001).Conclusion: The Nanodropper eyedrop bottle adaptor can significantly reduce drop volume and increase the overall number of drops dispensed compared with stock eyedrop bottles. Further studies are needed to elucidate the clinical impact of utilizing decreased drop volume with direct comparison to current standards of care.Keywords: ophthalmic medication, medication delivery, dry eye syndrome, glaucoma medications, medication adherence, drop assist devices

Published
2023

20. Verwendung von 'Hidden Markov Models' zur Sprecherunabhängigen Einzelworterkennung

Author

Steger, J., Hoffmann, G., Holzmann, D., Jäger, F., Riedling, K., Schwuttke, G. H., Pandelisev, K. A., White, R. C., Holzmann, H., Kausel, W., Nanz, G., Selberherr, S., Pötzl, H., Leopold, H., Röhrer, R., Winkler, G., Thurner, M., Seiner, K., Tritremmel, W., Walther, G., Schoitsch, Erwin, Hertl, S., Schaffar, G., Schmidt, K., Steinbrecher, H., Voggenberger, F., Windischhofer, W., Turba, R., Grabner, J., Aberl, H., Seifert, F., Buschbeck, F., Wallisch, K., Eichtinger, Ch., Wach, P., Bittinger, W., Kainz, A., Jestl, M., Beinstingl, W., Berthold, K., Köck, A., Gornik, E., Kloiber, G., Kreid, F., Schröcker, K. P., Schrödl, M., Brazda, E., Niedrist, G., Dietz, K., Fey, P., Frenkenberger, S., Furtner, M., Dejneka, B., Goiser, A., Sust, M., Kowatsch, M., Jorde, Ch., Thallinger, G. G., Mothwurf, E., Schubert, E., Steger, J., Trzeba, E., Awramow, I., Pucher, R., Auer, L. M., Schuy, S., Schima, H., Huber, L., Prodinger, A., Schmallegger, H., Thoma, H., Stöhr, H., Mayr, W., Steiner, R., Wiedenbauer, O., List, G., Wießpeiner, G., Petsch, Th., Doblhoff, G., Kirchner, D., Koudelka, O., Gierlinger, A., Ullrich, A., Braune, B., Horvat, H., Mayer, U., Gauby, A., Richter, A., Spiess, K. R., Klösch, W., Böck, N., Rosenkranz, H., Mitter, H., Hengl, M., Nussbaum, G., Gutternigh, K., Hahn, H., Koutny, P., Pühringer, K., Schwabach, H., Hirschler, M., Haas, M., Renner, A., Bratengeyer, E., Scholz-Nauendorff, C. C., Lebutsch, K., Volkmann, W., Gerner, H., Girsch, W., Holle, J., Kluger, P., Meister, B., Moritz, E., Schwanda, G., Prager, L., Wieβpeiner, G., Grübler, R., Dorfer, E., Oitzl, E., Pribyl, W., Bähring, M., Harter, J., and Sommer, D.

Published
1987
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21. Computed Flow About The Integrated Space Shuttle, Revisited

Author

Buning, P. G, Obayashi, S, Steger, J. L, Chiu, I. T, Martin, F. W., Jr, Meakin, R. L, Rizk, Y. M, and Yarrow, M

Subjects
Mechanics
Abstract

Report discusses numerical simulations of flow of air about integrated space shuttle (complete space shuttle assembly including orbiter, solid rocket boosters, and external tank) in ascent. Updated version of report described in "Computed Flow About The Integrated Space Shuttle" (ARC-12685). Goal of studies to improve understanding of, and ability to predict how integrated space shuttle performs during both nominal and aborted ascent under various conditions.

Published
1996

22. Dual-Potential Formulation Of Navier-Stokes Equations

Author

Gegg, S. G, Pletcher, R. H, and Steger, J. L

Subjects
Mechanics
Abstract

Report discusses research on dual-potential formulation of Navier-Stokes equations. Purpose of study to extend capability of dual-potential method to computation of unsteady flows of viscous, compressible fluids.

Published
1992

23. Computed Flow About The Integrated Space Shuttle

Author

Buning, P. G, Chiu, I. T, Obayashi, S, Rizk, Y. M, and Steger, J. L

Subjects
Mechanics
Abstract

Report discusses numerical simulations of flow of air about integrated Space Shuttle in ascent. Goal: to improve understanding of, and ability to predict, how integrated Space Shuttle will perform during both nominal and aborted ascent under various conditions. These and other numerical simulations intended both to supplement wind-tunnel data, corrupted to some extent by scaling and wall-interference effects, and to compensate for scarcity of valid flight data.

Published
1991

24. Calculating Viscous/Inviscid Interactions

Author

Van Dalsem, W. R, Steger, J. L, and Rao, K. V

Subjects
Mechanics
Abstract

Report describes some experiences in numerical simulation of compressible, viscous flows by finite-difference approximations of Navier-Stokes equations. Focuses upon viscous/inviscid-interaction approach, in which flow mathematically modeled with interacting zones, within each of which different model of viscous or inviscid flow applies. Reduces task of computation by taking advantage of simpler models and coarser grids in some of zones.

Published
1991

26. On computations of the integrated space shuttle flowfield using overset grids

Author

Chiu, I-T, Pletcher, R. H, and Steger, J. L

Subjects
Space Transportation
Abstract

Numerical simulations using the thin-layer Navier-Stokes equations and chimera (overset) grid approach were carried out for flows around the integrated space shuttle vehicle over a range of Mach numbers. Body-conforming grids were used for all the component grids. Testcases include a three-component overset grid - the external tank (ET), the solid rocket booster (SRB) and the orbiter (ORB), and a five-component overset grid - the ET, SRB, ORB, forward and aft attach hardware, configurations. The results were compared with the wind tunnel and flight data. In addition, a Poisson solution procedure (a special case of the vorticity-velocity formulation) using primitive variables was developed to solve three-dimensional, irrotational, inviscid flows for single as well as overset grids. The solutions were validated by comparisons with other analytical or numerical solution, and/or experimental results for various geometries. The Poisson solution was also used as an initial guess for the thin-layer Navier-Stokes solution procedure to improve the efficiency of the numerical flow simulations. It was found that this approach resulted in roughly a 30 percent CPU time savings as compared with the procedure solving the thin-layer Navier-Stokes equations from a uniform free stream flowfield.

Published
1990

31. Persistence of nasal colonization with human pathogenic bacteria and associated antimicrobial resistance in the German general population

Author

Köck, R., primary, Werner, P., additional, Friedrich, A.W., additional, Fegeler, C., additional, Becker, K., additional, Bindewald, O., additional, Bui, T.T., additional, Eckhoff, C., additional, Epping, R., additional, Kähmann, L., additional, Meurer, M., additional, Steger, J., additional, and von Auenmüller, L., additional

Published
2016
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32. 'Hybrid' scientific conference: lessons learned from the digital annual meeting of the CARS international conference during the Covid-19 pandemic

Author

Ostler Daniel, Steger Jana, Bernhard Lukas, Yu Kevin, Hartwig Regine, Feussner Hubertus, and Wilhelm Dirk

Subjects
covid-19 pandemic, digital conferences, feasibility of digital communication, scientific communication, Surgery, RD1-811
Abstract

Due to the coronavirus disease 2019 (Covid-19) pandemic, all scientific conferences in the year 2020 had to be adapted in their form of presence to accommodate for safety regulations, postponed, or canceled entirely. As organizers of the annual Computer Assisted Radiology & Surgery International Conference & Exhibition (CARS)-Conference 2020, we decided to hold a “hybrid” conference, i.e., a virtual conference with partial presence to mitigate the drawbacks of a purely virtual conference. It is the purpose of this paper to describe the results and experience gained by our first hybrid conference.

Published
2021
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33. Knockdown of parathyroid hormone related protein in smooth muscle cells alters renal hemodynamics but not blood pressure

Author

Raison, D. (Denis), Coquard, C. (Catherine), Hochane, M. (Mazène), Steger, J. (Jacques), Massfelder, T. (Thierry), Moulin, B. (Bruno), Karaplis, A. (A) C. (C), Metzger, D. (Daniel), Chambon, P. (Pierre), Helwig, J. (Jean-Jacques) J. (J), and Barthelmebs, M. (Mariette)

Subjects
Sciences du Vivant [q-bio]/Médecine humaine et pathologie, hormones, hormone substitutes, and hormone antagonists
Abstract

Parathyroid hormone-related protein (PTHrP) belongs to vasoactive factors that regulate blood pressure and renal hemodynamics both by reducing vascular tone and raising renin release. PTHrP is expressed in systemic and renal vasculature. Here, we wanted to assess the contribution of vascular smooth muscle cell endogenous PTHrP to the regulation of cardiovascular and renal functions. We generated a mouse strain (SMA-CreERT2/PTHrPL2/L2 or premutant PTHrPSM-/-), which allows temporally controlled, smooth muscle-targeted PTHrP knockdown in adult mice. Tamoxifen treatment induced efficient recombination of PTHrP-floxed alleles and decreased PTHrP expression in vascular and visceral smooth muscle cells of PTHrPSM-/- mice. Blood pressure remained unchanged in PTHrPSM-/- mice, but plasma renin concentration and creatinine clearance were reduced. Renal hemodynamics were further analyzed during clearance measurements in anesthetized mice. Conditional knockdown of PTHrP decreased renal plasma flow and glomerular filtration rate with concomitant reduction in filtration fraction. Similar measurements were repeated during acute saline volume expansion. Saline volume expansion induced a rise in renal plasma flow and reduced filtration fraction; both were blunted in PTHrPSM-/- mice leading to impaired diuresis. These findings show that endogenous vascular smooth muscle PTHrP controls renal hemodynamics under basal conditions, and it is an essential factor in renal vasodilation elicited by saline volume expansion.

Published
2013

40. Electromagnets for an endoscopic anastomosis tool in the colon

Author

Steger Jana, Zimmermann Anne, Wittenberg Thomas, and Wilhelm Dirk

Subjects
anastomosis, endoscopic intervention, magnets, electromagnets, colon, Medicine
Abstract

The goal of our research work is the development of a novel endoscopic anastomosis device for the colon. One of the main challenges in this context is the application of forces at the endoscope tip to rejoin the two bowel endings. Thus, we focus on a magnetic two-part compression implant approach. The implant halves are detached from the applicator units by means of electromagnets. In this contribution we present the results of our experiments to determine the implant design with special focus on tissue compression forces and the resultant electromagnet dimensioning to estimate size requirements of the application/detachment system. To achieve the targeted compression forces derived from literature, we used cubic N52 magnetized neodymium magnets1 with a side length of 5 mm and mild steel screws. For these magnets, we evaluated a required electromagnetic repulsion force of 4.1 N. For the electromagnetic detachment system this led to the need for 166 windings for the coils on oral side, and 146 windings for the coils at the aboral side. Based on these requirements, a colonoscope diameter (~14 mm) increase of 10.6 mm on the oral side and of 12 mm on the aboral side due to the application device must be assumed. Nevertheless, this diameter still remains within the size range of other colonoscopic tools, such as e.g., circular staplers.

Published
2021
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41. Toward a holistic federated future internet experimentation environment: the experience of NOVI research and experimentation

Author

Maglaris, V., primary, Papagianni, C., additional, Androulidakis, G., additional, Grammatikou, M., additional, Grosso, P., additional, Van Der Ham, J., additional, De Laat, C., additional, Pietrzak, B., additional, Belter, B., additional, Steger, J., additional, Laki, S., additional, Campanella, M., additional, and Sallent, S., additional

Published
2015
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43. Cross wedge rolling to preform light metal forgings

Author

Neugebauer, Reimund, Lorenz, B., Steger, J., and Publica

Subjects
light-metal-forging, Leichtmetallschmiedestück, Titanlegierung, preforming, resource management, titanium, cross wedge rolling, Querkeilwalzen, Masseverteilungszwischenform
Abstract

The forging of a component with oblong shape and complex geometry can not be realized in a single forming operation. Preforming operations are applied to ensure complete cavity filling with smallest amount of material loss, to avoid forging defects and to keep loads and wear of the dies low. In preforming the distribution of the material along the main axis can be realized either by displacement or by accumulation. In accumulation processes the cross section of a forging is increased while the length is reduced. The process limit is characterized by the failure mechanisms of outward bending and buckling.

Published
2009
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46. Mikroelektronik 87

Author

Hoffmann, G., primary, Holzmann, D., additional, Jäger, F., additional, Riedling, K., additional, Schwuttke, G. H., additional, Pandelisev, K. A., additional, White, R. C., additional, Holzmann, H., additional, Kausel, W., additional, Nanz, G., additional, Selberherr, S., additional, Pötzl, H., additional, Leopold, H., additional, Röhrer, R., additional, Winkler, G., additional, Thurner, M., additional, Seiner, K., additional, Tritremmel, W., additional, Walther, G., additional, Schoitsch, Erwin, additional, Hertl, S., additional, Schaffar, G., additional, Schmidt, K., additional, Steinbrecher, H., additional, Voggenberger, F., additional, Windischhofer, W., additional, Turba, R., additional, Grabner, J., additional, Aberl, H., additional, Seifert, F., additional, Buschbeck, F., additional, Wallisch, K., additional, Eichtinger, Ch., additional, Wach, P., additional, Bittinger, W., additional, Kainz, A., additional, Jestl, M., additional, Beinstingl, W., additional, Berthold, K., additional, Köck, A., additional, Gornik, E., additional, Kloiber, G., additional, Kreid, F., additional, Schröcker, K. P., additional, Schrödl, M., additional, Brazda, E., additional, Niedrist, G., additional, Dietz, K., additional, Fey, P., additional, Frenkenberger, S., additional, Furtner, M., additional, Dejneka, B., additional, Goiser, A., additional, Sust, M., additional, Kowatsch, M., additional, Jorde, Ch., additional, Thallinger, G. G., additional, Mothwurf, E., additional, Schubert, E., additional, Steger, J., additional, Trzeba, E., additional, Awramow, I., additional, Pucher, R., additional, Auer, L. M., additional, Schuy, S., additional, Schima, H., additional, Huber, L., additional, Prodinger, A., additional, Schmallegger, H., additional, Thoma, H., additional, Stöhr, H., additional, Mayr, W., additional, Steiner, R., additional, Wiedenbauer, O., additional, List, G., additional, Wießpeiner, G., additional, Petsch, Th., additional, Doblhoff, G., additional, Kirchner, D., additional, Koudelka, O., additional, Gierlinger, A., additional, Ullrich, A., additional, Braune, B., additional, Horvat, H., additional, Mayer, U., additional, Gauby, A., additional, Richter, A., additional, Spiess, K. R., additional, Klösch, W., additional, Böck, N., additional, Rosenkranz, H., additional, Mitter, H., additional, Hengl, M., additional, Nussbaum, G., additional, Gutternigh, K., additional, Hahn, H., additional, Koutny, P., additional, Pühringer, K., additional, Schwabach, H., additional, Hirschler, M., additional, Haas, M., additional, Renner, A., additional, Bratengeyer, E., additional, Scholz-Nauendorff, C. C., additional, Lebutsch, K., additional, Volkmann, W., additional, Gerner, H., additional, Girsch, W., additional, Holle, J., additional, Kluger, P., additional, Meister, B., additional, Moritz, E., additional, Schwanda, G., additional, Prager, L., additional, Wieβpeiner, G., additional, Grübler, R., additional, Dorfer, E., additional, Oitzl, E., additional, Pribyl, W., additional, Bähring, M., additional, Harter, J., additional, and Sommer, D., additional

Published
1987
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