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2. Laser-driven x-ray and proton micro-source and application to simultaneous single-shot bi-modal radiographic imaging.

Author

Ostermayr, TM, Kreuzer, C, Englbrecht, FS, Gebhard, J, Hartmann, J, Huebl, A, Haffa, D, Hilz, P, Parodi, K, Wenz, J, Donovan, ME, Dyer, G, Gaul, E, Gordon, J, Martinez, M, Mccary, E, Spinks, M, Tiwari, G, Hegelich, BM, and Schreiber, J

Subjects
Animals, Gryllidae, Protons, Radiography, Lasers, X-Rays, Multimodal Imaging
Abstract

Radiographic imaging with x-rays and protons is an omnipresent tool in basic research and applications in industry, material science and medical diagnostics. The information contained in both modalities can often be valuable in principle, but difficult to access simultaneously. Laser-driven solid-density plasma-sources deliver both kinds of radiation, but mostly single modalities have been explored for applications. Their potential for bi-modal radiographic imaging has never been fully realized, due to problems in generating appropriate sources and separating image modalities. Here, we report on the generation of proton and x-ray micro-sources in laser-plasma interactions of the focused Texas Petawatt laser with solid-density, micrometer-sized tungsten needles. We apply them for bi-modal radiographic imaging of biological and technological objects in a single laser shot. Thereby, advantages of laser-driven sources could be enriched beyond their small footprint by embracing their additional unique properties, including the spectral bandwidth, small source size and multi-mode emission.

Published
2020

3. Water-Window X-Ray Pulses from a Laser-Plasma Driven Undulator.

Author

Maier, AR, Kajumba, N, Guggenmos, A, Werle, C, Wenz, J, Delbos, N, Zeitler, B, Dornmair, I, Schmidt, J, Gullikson, EM, Krausz, F, Schramm, U, Kleineberg, U, Karsch, S, and Grüner, F

Abstract

Femtosecond (fs) x-ray pulses are a key tool to study the structure and dynamics of matter on its natural length and time scale. To complement radio-frequency accelerator-based large-scale facilities, novel laser-based mechanisms hold promise for compact laboratory-scale x-ray sources. Laser-plasma driven undulator radiation in particular offers high peak-brightness, optically synchronized few-fs pulses reaching into the few-nanometer (nm) regime. To date, however, few experiments have successfully demonstrated plasma-driven undulator radiation. Those that have, typically operated at single and comparably long wavelengths. Here we demonstrate plasma-driven undulator radiation with octave-spanning tuneability at discrete wavelengths reaching from 13 nm to 4 nm. Studying spontaneous undulator radiation is an important step towards a plasma-driven free-electron laser. Our specific setup creates a photon pulse, which closely resembles the plasma electron bunch length and charge profile and thus might enable novel methods to characterize the longitudinal electron phase space.

Published
2020

4. Dual-energy electron beams from a compact laser-driven accelerator

Author

Wenz, J., Khrennikov, K., Döpp, A., Gilljohann, M., Ding, H., Goetzfried, J., Schindler, S., Buck, A., Xu, J., Heigoldt, M., Helml, W., Veisz, L., and Karsch, S.

Subjects
Physics - Accelerator Physics, Physics - Optics, Physics - Plasma Physics
Abstract

Ultrafast pump-probe experiments open the possibility to track fundamental material behaviour like changes in its electronic configuration in real time. To date, most of these experiments are performed using an electron or a high-energy photon beam, which is synchronized to an infrared laser pulse. Entirely new opportunities can be explored if not only a single, but multiple synchronized, ultra-short, high-energy beams are used. However, this requires advanced radiation sources that are capable of producing dual-energy electron beams, for example. Here, we demonstrate simultaneous generation of twin-electron beams from a single compact laser wakefield accelerator. The energy of each beam can be individually adjusted over a wide range and our analysis shows that the bunch lengths and their delay inherently amount to femtoseconds. Our proof-of-concept results demonstrate an elegant way to perform multi-beam experiments in future on a laboratory scale.

Published
2018
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5. Research towards high-repetition rate laser-driven X-ray sources for imaging applications

Author

Götzfried, J., Döpp, A., Gilljohann, M., Ding, H., Schindler, S., Wenz, J., Hehn, L., Pfeiffer, F., and Karsch, S.

Subjects
Physics - Medical Physics, Physics - Accelerator Physics, Physics - Optics, Physics - Plasma Physics
Abstract

Laser wakefield acceleration of electrons represents a basis for several types of novel X-ray sources based on Thomson scattering or betatron radiation. The latter provides a high photon flux and a small source size, both being prerequisites for high-quality X-ray imaging. Furthermore, proof-of-principle experiments have demonstrated its application for tomographic imaging. So far this required several hours of acquisition time for a complete tomographic data set. Based on improvements to the laser system, detectors and reconstruction algorithms, we were able to reduce this time for a full tomographic scan to 3 minutes. In this paper, we discuss these results and give a prospect to future imaging systems.

Published
2018
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6. Dual-energy electron beams from a compact laser-driven accelerator

Author

Wenz, J, Döpp, A, Khrennikov, K, Schindler, S, Gilljohann, MF, Ding, H, Götzfried, J, Buck, A, Xu, J, Heigoldt, M, Helml, W, Veisz, L, and Karsch, S

Subjects
Affordable and Clean Energy, Mathematical Sciences, Physical Sciences, Optoelectronics & Photonics
Abstract

Ultrafast pump–probe experiments open the possibility to track fundamental material behaviour, such as changes in electronic configuration, in real time. To date, most of these experiments are performed using an electron or a high-energy photon beam that is synchronized to an infrared laser pulse. Entirely new opportunities can be explored if not only a single, but multiple synchronized, ultrashort, high-energy beams are used. However, this requires advanced radiation sources that are capable of producing dual-energy electron beams, for example. Here, we demonstrate simultaneous generation of twin-electron beams from a single compact laser wakefield accelerator. The energy of each beam can be individually adjusted over a wide range and our analysis shows that the bunch lengths and their delay inherently amount to femtoseconds. Our proof-of-concept results demonstrate an elegant way to perform multi-beam experiments in the future on a laboratory scale.

Published
2019

7. Quick X-ray microtomography using a laser-driven betatron source

Author

Döpp, A., Hehn, L., Goetzfried, J., Wenz, J., Gilljohann, M., Ding, H., Schindler, S., Pfeiffer, F., and Karsch, S.

Subjects
Physics - Optics, Physics - Medical Physics
Abstract

Laser-driven X-ray sources are an emerging alternative to conventional X-ray tubes and synchrotron sources. We present results on microtomographic X-ray imaging of a cancellous human bone sample using synchrotron-like betatron radiation. The source is driven by a 100-TW-class titanium-sapphire laser system and delivers over $10^8$ X-ray photons per second. Compared to earlier studies, the acquisition time for an entire tomographic dataset has been reduced by more than an order of magnitude. Additionally, the reconstruction quality benefits from the use of statistical iterative reconstruction techniques. Depending on the desired resolution, tomographies are thereby acquired within minutes, which is an important milestone towards real-life applications of laser-plasma X-ray sources.

Published
2017

8. Quantitative X-Ray Phase-Contrast Microtomography from a Compact Laser Driven Betatron Source

Author

Wenz, J., Schleede, S., Khrennikov, K., Bech, M., Thibault, P., Heigoldt, M., Pfeiffer, F., and Karsch, S.

Subjects
Physics - Plasma Physics
Abstract

X-ray phase-contrast imaging has recently led to a revolution in resolving power and tissue contrast in biomedical imaging, microscopy and materials science. The necessary high spatial coherence is currently provided by either large-scale synchrotron facilities with limited beamtime access or by microfocus X-ray tubes with rather limited flux. X-rays radiated by relativistic electrons driven by well-controlled high-power lasers offer a promising route to a proliferation of this powerful imaging technology. A laser-driven plasma wave accelerates and wiggles electrons, giving rise to brilliant keV X-ray emission. This so-called Betatron radiation is emitted in a collimated beam with excellent spatial coherence and remarkable spectral stability. Here we present the first phase-contrast micro-tomogram revealing quantitative electron density values of a biological sample using betatron X-rays, and a comprehensive source characterization. Our results suggest that laser-based X-ray technology offers the potential for filling the large performance gap between synchrotron- and current X-ray tube-based sources., Comment: 16 pages, 5 figures, submitted to Nature Communication

Published
2014
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9. Tunable, all-optical quasi-monochromatic Thomson X-ray source

Author

Khrennikov, K., Wenz, J., Buck, A., Xu, J., Heigoldt, M., Veisz, L., and Karsch, S.

Subjects
Physics - Plasma Physics, Physics - Accelerator Physics
Abstract

Brilliant X-ray sources are of great interest for many research fields from biology via medicine to material research. The quest for a cost-effective, brilliant source with unprecedented temporal resolution has led to the recent realization of various high-intensity-laser-driven X-ray beam sources. Here we demonstrate the first all-laser-driven, energy-tunable and quasi-monochromatic X-ray source based on Thomson backscattering. This is a decisive step beyond previous results, where the emitted radiation exhibited an uncontrolled broad energy distribution. In the experiment, one part of the laser beam was used to drive a few-fs bunch of quasi-monoenergetic electrons from a Laser-Wakefield Accelerator (LWFA), while the remainder was scattered off the bunch in a near-counter-propagating geometry. When the electron energy was tuned from 10-50 MeV, narrow-bandwidth X-ray spectra peaking at 5-35keV were directly measured, limited in photon energy by the sensitivity curve of our X-ray detector. Due to the ultrashort LWFA electron bunches, these beams exhibit few-fs pulse duration., Comment: Submitted to Nature Photonics on 12.09.2013

Published
2014

10. Temporal evolution of longitudinal bunch profile in a laser wakefield accelerator

Author

Heigoldt, M., Bajlekov, S. I., Popp, A., Khrennikov, K., Wenz, J., Chou, S. W., Schmidt, B., Hooker, S. M., and Karsch, S.

Subjects
Physics - Plasma Physics, Physics - Accelerator Physics
Abstract

Due to their ultra-short duration and peak currents in the kA range, laser-wakefield accelerated electron bunches are promising drivers for ultrafast X-ray generation in compact free-electron-lasers (FELs), Thomson-scattering or betatron sources. Here we present the first single-shot, high-resolution measurements of the longitudinal bunch profile obtained without prior assumptions about the bunch shape. Our method allows complex features, such as multi-bunch structures, to be detected. Varying the length of the gas target, and thus the acceleration length, enables an assessment of the bunch profile evolution during the acceleration process. We find a minimum bunch duration of 4.2 fs (full width at half maximum) with shot-to-shot fluctuation of 11% rms. Our results suggest that after depletion of the laser energy, a transition from a laser-driven to a particle-driven wakefield occurs, associated with the injection of a secondary bunch. The resulting double-bunch structure might act as an elegant approach for driver-witness type experiments, i.e. allowing a non-dephasing-limited acceleration of the secondary bunch in a plasma-afterburner stage.

Published
2014
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15. Water-Window X-Ray Pulses from a Laser-Plasma Driven Undulator

Author

Maier, A. R., Kajumba, N., Guggenmos, A., Werle, C., Wenz, J., Delbos, N., Zeitler, B., Dornmair, I., Schmidt, J., Gullikson, E. M., Krausz, F., (0000-0003-0390-7671) Schramm, U., Kleineberg, U., Karsch, S., Gruner, F., Maier, A. R., Kajumba, N., Guggenmos, A., Werle, C., Wenz, J., Delbos, N., Zeitler, B., Dornmair, I., Schmidt, J., Gullikson, E. M., Krausz, F., (0000-0003-0390-7671) Schramm, U., Kleineberg, U., Karsch, S., and Gruner, F.

Abstract

Femtosecond (fs) x-ray pulses are a key tool to study the structure and dynamics of matter on its natural length and time scale. To complement radio-frequency accelerator-based large-scale facilities, novel laser-based mechanisms hold promise for compact laboratory-scale x-ray sources. Laser-plasma driven undulator radiation in particular offers high peak-brightness, optically synchronized few-fs pulses reaching into the few-nanometer (nm) regime. To date, however, few experiments have successfully demonstrated plasma-driven undulator radiation. Those that have, typically operated at single and comparably long wavelengths. Here we demonstrate plasma-driven undulator radiation with octave-spanning tuneability at discrete wavelengths reaching from 13 nm to 4 nm. Studying spontaneous undulator radiation is an important step towards a plasma-driven free-electron laser. Our specific setup creates a photon pulse, which closely resembles the plasma electron bunch length and charge profile and thus might enable novel methods to characterize the longitudinal electron phase space.

Published
2020

19. Dual-energy electron beams from a compact laser-driven accelerator

Author

Wenz, J., Döpp, A., Khrennikov, K., Schindler, S., Gilljohann, M. F., Ding, H., Götzfried, J., Buck, A., Xu, J., Heigoldt, M., Helml, W., Veisz, Laszlo, Karsch, S., Wenz, J., Döpp, A., Khrennikov, K., Schindler, S., Gilljohann, M. F., Ding, H., Götzfried, J., Buck, A., Xu, J., Heigoldt, M., Helml, W., Veisz, Laszlo, and Karsch, S.

Abstract

Ultrafast pump–probe experiments open the possibility to track fundamental material behaviour, such as changes in electronic configuration, in real time. To date, most of these experiments are performed using an electron or a high-energy photon beam that is synchronized to an infrared laser pulse. Entirely new opportunities can be explored if not only a single, but multiple synchronized, ultrashort, high-energy beams are used. However, this requires advanced radiation sources that are capable of producing dual-energy electron beams, for example. Here, we demonstrate simultaneous generation of twin-electron beams from a single compact laser wakefield accelerator. The energy of each beam can be individually adjusted over a wide range and our analysis shows that the bunch lengths and their delay inherently amount to femtoseconds. Our proof-of-concept results demonstrate an elegant way to perform multi-beam experiments in the future on a laboratory scale.

Published
2019
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25. Laser interactions with micro-targets for imaging applications

Author

Ostermayr, T. M., primary, Kreuzer, C., additional, Englbrecht, F., additional, Hartmann, J., additional, Gebhard, J., additional, Speicher, M., additional, Haffa, D., additional, Hilz, P., additional, Bin, J., additional, McCary, E., additional, Stork, S., additional, Dyer, G., additional, Donovan, M. E., additional, Ditmire, T., additional, Hegelich, B. M., additional, Martinez, M., additional, Gaul, E., additional, Wenz, J., additional, Parodi, K., additional, Gordon, J., additional, Spinks, M., additional, Bolton, P. R., additional, and Schreiber, J., additional

Published
2017
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26. Collective Deceleration of Laser-Driven Electron Bunches

Author

Chou, Shao-wei, Xu, J., Khrennikov, K., Cardenas, Daniel E., Wenz, J., Heigoldt, M., Hofmann, L., Veisz, Laszlo, Karsch, S., Chou, Shao-wei, Xu, J., Khrennikov, K., Cardenas, Daniel E., Wenz, J., Heigoldt, M., Hofmann, L., Veisz, Laszlo, and Karsch, S.

Abstract

Few-fs electron bunches from laser wakefield acceleration (LWFA) can efficiently drive plasma wakefields (PWFs), as shown by their propagation through underdense plasma in two experiments. A strong and density-insensitive deceleration of the bunches has been observed in 2 mm of 1018 cm−3 density plasma with 5.1 GV=m average gradient, which is attributed to a self-driven PWF. This observation implies that the physics of PWFs, usually relying on large-scale rf accelerators as drivers, can be studied by tabletop LWFA electron sources.

Published
2016
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30. Tunable All-Optical Quasimonochromatic Thomson X-Ray Sourcein the Nonlinear Regime

Author

Khrennikov, K., Wenz, J., Buck, A., Xu, Jiancai, Heigoldt, M., Veisz, Laszlo, Karsch, S., Khrennikov, K., Wenz, J., Buck, A., Xu, Jiancai, Heigoldt, M., Veisz, Laszlo, and Karsch, S.

Abstract

We present an all-laser-driven, energy-tunable, and quasimonochromatic x-ray source based on Thomson scattering from laser-wakefield-accelerated electrons. One part of the laser beam was used to drive a few-fs bunch of quasimonoenergetic electrons, while the remainder was backscattered off the bunch at weakly relativistic intensity. When the electron energy was tuned from 17–50 MeV, narrow x-ray spectra peaking at 5–42 keV were recorded with high resolution, revealing nonlinear features. We present a large set of measurements showing the stability and practicality of our source.

Published
2015
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31. How strict is galactose restriction in adults with galactosaemia? International practice

Author

Adam, Siddig Momin, Akroyd, R., Bernabei, S., Bollhalder, S., Boocock, S., Burlina, A., Coote, T., Corthouts, K., Dalmau, Judith, Dawson, S., Defourny, S., Meyer, A., Desloovere, A., Devlin, Y., Diels, M., Dokoupil, K., Donald, S., Evans, S., Fasan, I., Ferguson, C., Ford, S., Forga, M., Gallo, G., Grünert, S.C., Heddrich-Ellerbrok, M., Heidenborg, C., Jonkers, C.F., Lefebure, K., Luyten, K., MacDonald, A., Meyer, U., Micciche, A., Müller, E., Portnoi, P., Ripley, S., Robert, C.M., Robertson, L.V., Rosenbaum-Fabian, S., Sahm, K., Schultz, Erica S, Singleton, K., Sjöqvist, E., Stoelen, L., Terry, A., Thompson, S., Timmer, C., Vande Kerckhove, K., van den Ploeg, L., Van Driessche, M., van Rijn, M., van Teeffelen-Heithoff, A., Vitoria, I., Voillot, C., Wenz, J., Westbrook, M., Wildgoose, J., Zweers, H., Adam, Siddig Momin, Akroyd, R., Bernabei, S., Bollhalder, S., Boocock, S., Burlina, A., Coote, T., Corthouts, K., Dalmau, Judith, Dawson, S., Defourny, S., Meyer, A., Desloovere, A., Devlin, Y., Diels, M., Dokoupil, K., Donald, S., Evans, S., Fasan, I., Ferguson, C., Ford, S., Forga, M., Gallo, G., Grünert, S.C., Heddrich-Ellerbrok, M., Heidenborg, C., Jonkers, C.F., Lefebure, K., Luyten, K., MacDonald, A., Meyer, U., Micciche, A., Müller, E., Portnoi, P., Ripley, S., Robert, C.M., Robertson, L.V., Rosenbaum-Fabian, S., Sahm, K., Schultz, Erica S, Singleton, K., Sjöqvist, E., Stoelen, L., Terry, A., Thompson, S., Timmer, C., Vande Kerckhove, K., van den Ploeg, L., Van Driessche, M., van Rijn, M., van Teeffelen-Heithoff, A., Vitoria, I., Voillot, C., Wenz, J., Westbrook, M., Wildgoose, J., and Zweers, H.

Published
2015

32. How strict is galactose restriction in adults with galactosaemia? International practice

Author

Adam, S., Akroyd, R., Bernabei, S., Bollhalder, S., Boocock, S., Burlina, A., Coote, T., Corthouts, K., Dalmau, J., Dawson, S., Defourny, S., Meijer, A, Desloovere, A., Devlin, Y., Diels, M., Dokoupil, K., Donald, S., Evans, S., Fasan, I., Ferguson, C., Ford, S., Forga, M., Gallo, G., Grunert, S.C., Heddrich-Ellerbrok, M., Heidenborg, C., Jonkers, C., Lefebure, K., Luyten, K., Macdonald, A., Meyer, U., Micciche, A., Muller, E., Portnoi, P., Ripley, S., Robert, M., Robertson, L.V., Rosenbaum-Fabian, S., Sahm, K., Schultz, S., Singleton, K., Sjoqvist, E., Stoelen, L., Terry, A., Thompson, S., Timmer, C., Kerckhove, K. Vande, Ploeg, L. van der, Driessche, M. Van, Rijn, M. van de, Teeffelen-Heithoff, A. van, Vitoria, I., Voillot, C., Wenz, J., Westbrook, M., Wildgoose, J., Zweers, H.E., Adam, S., Akroyd, R., Bernabei, S., Bollhalder, S., Boocock, S., Burlina, A., Coote, T., Corthouts, K., Dalmau, J., Dawson, S., Defourny, S., Meijer, A, Desloovere, A., Devlin, Y., Diels, M., Dokoupil, K., Donald, S., Evans, S., Fasan, I., Ferguson, C., Ford, S., Forga, M., Gallo, G., Grunert, S.C., Heddrich-Ellerbrok, M., Heidenborg, C., Jonkers, C., Lefebure, K., Luyten, K., Macdonald, A., Meyer, U., Micciche, A., Muller, E., Portnoi, P., Ripley, S., Robert, M., Robertson, L.V., Rosenbaum-Fabian, S., Sahm, K., Schultz, S., Singleton, K., Sjoqvist, E., Stoelen, L., Terry, A., Thompson, S., Timmer, C., Kerckhove, K. Vande, Ploeg, L. van der, Driessche, M. Van, Rijn, M. van de, Teeffelen-Heithoff, A. van, Vitoria, I., Voillot, C., Wenz, J., Westbrook, M., Wildgoose, J., and Zweers, H.E.

Abstract

Item does not contain fulltext, Dietary management of 418 adult patients with galactosaemia (from 39 centres/12 countries) was compared. All centres advised lactose restriction, 6 restricted galactose from galactosides +/- fruits and vegetables and 12 offal. 38% (n=15) relaxed diet by: 1) allowing traces of lactose in manufactured foods (n=13) or 2) giving fruits, vegetables and galactosides (n=2). Only 15% (n=6) calculated dietary galactose. 32% of patients were lost to dietetic follow-up. In adult galactosaemia, there is limited diet relaxation.

Published
2015

33. How strict is galactose restriction in adults with galactosaemia? International practice

Author

Afdeling Dietetiek, Other research (not in main researchprogram), Adam, Siddig Momin, Akroyd, R., Bernabei, S., Bollhalder, S., Boocock, S., Burlina, A., Coote, T., Corthouts, K., Dalmau, Judith, Dawson, S., Defourny, S., Meyer, A., Desloovere, A., Devlin, Y., Diels, M., Dokoupil, K., Donald, S., Evans, S., Fasan, I., Ferguson, C., Ford, S., Forga, M., Gallo, G., Grünert, S.C., Heddrich-Ellerbrok, M., Heidenborg, C., Jonkers, C.F., Lefebure, K., Luyten, K., MacDonald, A., Meyer, U., Micciche, A., Müller, E., Portnoi, P., Ripley, S., Robert, C.M., Robertson, L.V., Rosenbaum-Fabian, S., Sahm, K., Schultz, Erica S, Singleton, K., Sjöqvist, E., Stoelen, L., Terry, A., Thompson, S., Timmer, C., Vande Kerckhove, K., van den Ploeg, L., Van Driessche, M., van Rijn, M., van Teeffelen-Heithoff, A., Vitoria, I., Voillot, C., Wenz, J., Westbrook, M., Wildgoose, J., Zweers, H., Afdeling Dietetiek, Other research (not in main researchprogram), Adam, Siddig Momin, Akroyd, R., Bernabei, S., Bollhalder, S., Boocock, S., Burlina, A., Coote, T., Corthouts, K., Dalmau, Judith, Dawson, S., Defourny, S., Meyer, A., Desloovere, A., Devlin, Y., Diels, M., Dokoupil, K., Donald, S., Evans, S., Fasan, I., Ferguson, C., Ford, S., Forga, M., Gallo, G., Grünert, S.C., Heddrich-Ellerbrok, M., Heidenborg, C., Jonkers, C.F., Lefebure, K., Luyten, K., MacDonald, A., Meyer, U., Micciche, A., Müller, E., Portnoi, P., Ripley, S., Robert, C.M., Robertson, L.V., Rosenbaum-Fabian, S., Sahm, K., Schultz, Erica S, Singleton, K., Sjöqvist, E., Stoelen, L., Terry, A., Thompson, S., Timmer, C., Vande Kerckhove, K., van den Ploeg, L., Van Driessche, M., van Rijn, M., van Teeffelen-Heithoff, A., Vitoria, I., Voillot, C., Wenz, J., Westbrook, M., Wildgoose, J., and Zweers, H.

Published
2015

34. Das BH3-Mimetikum Obatoclax verhindert das Tumorwachstum im orthotopen Mausmodell für Hepatoblastome

Author

Lieber, J, Ellerkamp, V, Vogt, F, Wenz, J, Warmann, S, Fuchs, J, and Armeanu-Ebinger, S

Subjects
ddc: 610, 610 Medical sciences, Medicine
Abstract

Einleitung: Sowohl Resistenzen auf Chemotherapeutika als auch die Metastasierung repräsentieren die größten Herausforderungen bei der Behandlung von hoch-Risiko Hepatoblastomen (HB) und erfordern neue Behandlungsalternativen. Apoptose-Modulatoren wie die BH3-Mimetika Obatoclax und ABT-737[for full text, please go to the a.m. URL], 130. Kongress der Deutschen Gesellschaft für Chirurgie

Published
2013
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35. It doesn't take longer to keep good health records on dairies

Author

Giebel, S. K., Wenz, J. R., Poisson, S. A., Moore, D. A., and Schneider, C. S.

Subjects
Consistency (negotiation), Health management system, Medical record, media_common.quotation_subject, Operations management, Quality (business), Business, Disease, Culling, Health records, Dairy cattle, media_common
Abstract

For those attempting to understand risks for disease and how to make genetic improvement in the health of dairy cattle, on-farm health records are generally perceived to be of poor quality and limited utility. However, a survey of WA and ID dairies found that 83% of 237 respondents were satisfied with the quality and usefulness of their health records, which were used primarily for making individual cow culling and treatment decisions. Additionally, treatment records are viewed as an important tool to avoid drug residues in meat and milk. In a study of 50 herds, only 56%, 30%, and 30% of the dairies entered treatments given when recording mastitis, metritis, and lameness events, respectively. Taken together; these facts indicate that 'Good Health Records' must address three important functions: individual cow health management decision making, drug residue avoidance and regulatory compliance, and herd health management decision making. Current user-defined dairy health records often lack the necessary accuracy and consistency required of 'Good Health Records'. Until common dairy management software define health data entry in a similar manner as that for reproduction data entry, dairies will need to implement standard health data entry protocols to achieve 'Good Health Records'. Many dairy producers are concerned that implementation of standard health data entry protocols will take too much time. The objective of this study was to determine the change in time required to capture and enter health data following implementation of standard health data entry protocols and determine the amount of feedback required to achieve protocol compliance., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2012

Published
2012
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36. Preliminary Evaluation of Two Methods for Estimating Lameness Prevalence on Western US Dairies

Author

Hoffman, A. C., Wenz, J. R., Vanegas, J., and Moore, D. A.

Subjects
business.industry, Lameness, Herd management, Statistics, Medicine, Sampling (statistics), business, Herd prevalence, Milking
Abstract

The sampling strategy using milking parlor exit order was effective at estimating herd prevalence when samples from all pens were combined. Pen level variation requires sampling all pens. The presence of an arched-back position in cows in lock-ups predicts lameness in those cows, but these preliminary data suggest that this lameness assessment strategy underestimates herd prevalence. However, lameness assessment using arched-back position has promise for wide adoption, as it could easily be incorporated into routine herd management procedures. Further work is needed to refine and validate the arched-back method., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2011

Published
2011
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40. How strict is galactose restriction in adults with galactosaemia? International practice

Author

Adam, S., primary, Akroyd, R., additional, Bernabei, S., additional, Bollhalder, S., additional, Boocock, S., additional, Burlina, A., additional, Coote, T., additional, Corthouts, K., additional, Dalmau, J., additional, Dawson, S., additional, Defourny, S., additional, De Meyer, A., additional, Desloovere, A., additional, Devlin, Y., additional, Diels, M., additional, Dokoupil, K., additional, Donald, S., additional, Evans, S., additional, Fasan, I., additional, Ferguson, C., additional, Ford, S., additional, Forga, M., additional, Gallo, G., additional, Grünert, S.C., additional, Heddrich-Ellerbrok, M., additional, Heidenborg, C., additional, Jonkers, C., additional, Lefebure, K., additional, Luyten, K., additional, MacDonald, A., additional, Meyer, U., additional, Micciche, A., additional, Müller, E., additional, Portnoi, P., additional, Ripley, S., additional, Robert, M., additional, Robertson, L.V., additional, Rosenbaum-Fabian, S., additional, Sahm, K., additional, Schultz, S., additional, Singleton, K., additional, Sjöqvist, E., additional, Stoelen, L., additional, Terry, A., additional, Thompson, S., additional, Timmer, C., additional, Vande Kerckhove, K., additional, van der Ploeg, L., additional, Van Driessche, M., additional, van Rijn, M., additional, van Teeffelen-Heithoff, A., additional, Vitoria, I., additional, Voillot, C., additional, Wenz, J., additional, Westbrook, M., additional, Wildgoose, J., additional, and Zweers, H., additional

Published
2015
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41. Descriptive Epidemiology of Adult Dairy Cow Mortalities on a Modern Colorado Dairy

Author

Severidt, J. A., Garry, F. B., Gould, D. H., Wenz, J. R., and Lombard, J. E.

Subjects
Mortality rate, Environmental health, Specific risk, Classification scheme, Biology, Descriptive epidemiology, Dairy cattle
Abstract

Studies have reported that mortality rates for adult dairy cows have been increasing over the past couple of decades and are now between 4 and 12% at the state level. None of these studies looked closely at the causes or specific risk factors associated with death. The objectives of this study were 1) to determine the causes of death of adult dairy cattle on a modern dairy farm and 2) to identify a classification scheme that facilitates directed management changes to reduce mortality., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2006

Published
2006
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42. Association between Local (Udder) Clinical Signs and Important Outcomes of Clinical Mastitis Episodes in Dairy Cattle

Author

Wenz, J. R., Elia, R., Whitman, K., and Garry, F. B.

Subjects
Systemic disease, medicine.medical_specialty, medicine.anatomical_structure, Infectious disease (medical specialty), business.industry, Internal medicine, Mammary gland, medicine, Udder, medicine.disease, business, Dairy cattle, Mastitis
Abstract

Clinical mastitis (CM) is the most common infectious disease of dairy cattle and is responsible for significant economic losses. There are many local clinical signs associated with inflammatory changes of the mammary gland during bacterial infection. Treatment and prognosis of CM is often decided based on one or more of these clinical signs, however, there have been no studies evaluating the association of important outcomes associated with CM and the presence of these signs in cows with mild systemic disease., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2005

Published
2005
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44. X-ray Generation by Relativistic Laser-Accelerated Electrons

Author

Karsch, S., primary, Wenz, J., additional, Khrennikov, K., additional, Heigoldt, M., additional, Popp, A., additional, Buck, A., additional, Xu, J., additional, Veisz, L., additional, Chou, S-W., additional, Maier, A., additional, Kajumba, N., additional, Seggebrock, T., additional, Grüner, F., additional, Guggenmos, A., additional, Kleineberg, U., additional, Schleede, S., additional, Bech, M., additional, Thibault, P., additional, and Pfeiffer, F., additional

Published
2014
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45. Epidemic of Mycoplasma Mastitis in a Colorado Dairy Herd Following Expansion from 350 to 2,500 Milking Cows

Author

Hirst, H., Garry, F., and Wenz, J.

Subjects
education.field_of_study, Veterinary medicine, Animal health, Biosecurity, Population, Outbreak, medicine.disease, Milking, Mastitis, Geography, Herd, medicine, Mycoplasma mastitis, education
Abstract

Over the past two decades, dairies in the Western United States (US) have been expanding by purchasing cattle from various sources within the country.1 During year 2001, cow numbers in the West increased by 72,000 head, while the dairy cow population in the rest of the country declined by a total of 163,000 head.2 The National Animal health Monitoring System (NAHMS) study conducted in 1996 reported that 44% of operations brought cattle onto their dairies during 1995. Among herds with 200 or more milk cows, 65% of herds brought cattle onto the dairy from an outside source.3 Avoidance of severe losses from introduction and spread of disease requires biosecurity practices at multiple checkpoints, plus a plan for handling problems that occur. The objective of this herd report was to describe an epidemic of Mycoplasma (Myco) mastitis in a recently expanded Colorado dairy herd and to analyze reasons for the outbreak., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2003

Published
2003
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46. Use of a Cow-side Antibiotic Susceptibility Test to Predict Gram Staining Characteristics of Clinical Mastitis Pathogens of Dairy Cattle

Author

Wenz, J., Elia, R., Lawson, S., and Garry, F.

Subjects
business.industry, medicine.drug_class, Antibiotics, medicine.disease, Mastitis, law.invention, Microbiology, Rapid identification, Gram staining, law, Medicine, business, Pathogen, Dairy cattle, Susceptibility pattern
Abstract

Gram-staining characteristics of mastitis pathogens are an important consideration when developing mastitis treatment protocols. Rapid identification of clinical episodes due to gram-negative pathogens could reduce the use of intramammary mastitis (IMM) treatments with poor efficacy, while ensuring treatment of environmental streptococci infections. The objective of this study was to determine if the MASTiK® cow-side antibiotic susceptibility test could be used to predict whether a clinical mastitis episode was caused by a gram-negative pathogen, based on the susceptibility pattern obtained from the test, with the assumption that gram-negative clinical mastitis would not be treated with intramammary antibiotics., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2003

Published
2003
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47. Shock-Front Injector for High-Quality Laser-Plasma Acceleration

Author

Buck, A., Wenz, J., Xu, Jiancai, Khrennikov, K., Schmid, K., Heigoldt, M., Mikhailova, J. M., Geissler, M., Shen, B., Krausz, F., Karsch, S., Veisz, László, Buck, A., Wenz, J., Xu, Jiancai, Khrennikov, K., Schmid, K., Heigoldt, M., Mikhailova, J. M., Geissler, M., Shen, B., Krausz, F., Karsch, S., and Veisz, László

Abstract

We report the generation of stable and tunable electron bunches with very low absolute energy spread (ΔE≈5 MeV) accelerated in laser wakefields via injection and trapping at a sharp downward density jump produced by a shock front in a supersonic gas flow. The peak of the highly stable and reproducible electron energy spectrum was tuned over more than 1 order of magnitude, containing a charge of 1–100 pC and a charge per energy interval of more than 10 pC/MeV. Laser-plasma electron acceleration with Ti:sapphire lasers using this novel injection mechanism provides high-quality electron bunches tailored for applications.

Published
2013
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48. Shock-Front Injector for High-Quality Laser-Plasma Acceleration

Author

Buck, A., primary, Wenz, J., additional, Xu, J., additional, Khrennikov, K., additional, Schmid, K., additional, Heigoldt, M., additional, Mikhailova, J. M., additional, Geissler, M., additional, Shen, B., additional, Krausz, F., additional, Karsch, S., additional, and Veisz, L., additional

Published
2013
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49. Investigation of GeV-scale electron acceleration in a gas-filled capillary discharge waveguide

Author

Walker, P A, primary, Bourgeois, N, additional, Rittershofer, W, additional, Cowley, J, additional, Kajumba, N, additional, Maier, A R, additional, Wenz, J, additional, Werle, C M, additional, Karsch, S, additional, Grüner, F, additional, Symes, D R, additional, Rajeev, P P, additional, Hawkes, S J, additional, Chekhlov, O, additional, Hooker, C J, additional, Parry, B, additional, Tang, Y, additional, and Hooker, S M, additional

Published
2013
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