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1. Time dependency of bone density estimation from computed tomography with intravenous contrast agent administration

Author

Michael Scheel, K. Acu, and A. S. Issever

Subjects
Adult, Male, medicine.medical_specialty, Time Factors, Bone density, Endocrinology, Diabetes and Metabolism, Osteoporosis, Contrast Media, Computed tomography, Drug Administration Schedule, Sex Factors, Lumbar, Bone Density, Hounsfield scale, medicine, Humans, Time dependency, Quantitative computed tomography, Infusions, Intravenous, Osteoporosis, Postmenopausal, Aged, Retrospective Studies, Bone mineral, Lumbar Vertebrae, medicine.diagnostic_test, business.industry, Age Factors, Middle Aged, medicine.disease, Female, Radiology, Tomography, X-Ray Computed, Nuclear medicine, business
Abstract

Our study has demonstrated that in contrast-enhanced multi-detector computed tomography (MDCT)-based bone density measurements, the scan delay time after contrast agent administration is a statistically significant variable for the derivation of quantitative computed tomography (QCT)-equivalent bone mineral density (BMD) values. Earlier investigators have proposed to derive QCT-equivalent BMD values from contrast-enhanced MDCT scans by using a merely density-based conversion equation. The purpose of this study was to investigate whether the scan delay after intravenous (IV) contrast agent administration might affect BMD values derived in this way. A retrospective data analysis was performed on 198 subjects who underwent standardized biphasic MDCT. Average densities values (in Hounsfield units) of lumbar vertebral bodies 1 to 3 (L1–L3) were compared between phases I and II of the biphasic MDCT scan. Furthermore, QCT-equivalent BMD (BMDQCT) values were calculated using a previously published conversion equation. Paired t-test analysis revealed that IV contrast agent administration leads to a statistically significant increase (8.6 %; p

Published
2013
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2. Diffuse idiopathic skeletal hyperostosis (DISH): relation to vertebral fractures and bone density

Author

E. Barrett-Connor, Tm M. Link, K. Peters, Eric S. Orwoll, As S. Issever, F. Engelken, Gerd Diederichs, Dm M. Black, Bernd Hamm, and Lm M. Marshall

Subjects
musculoskeletal diseases, Male, Hyperostosis, medicine.medical_specialty, Bone density, MrOS, Endocrinology, Diabetes and Metabolism, Osteoporosis, Thoracic Vertebrae, 03 medical and health sciences, DISH, 0302 clinical medicine, Absorptiometry, Photon, Bone Density, Ankylosing hyperostosis, medicine, Humans, Diffuse Idiopathic Skeletal Hyperostosis, Aged, 030203 arthritis & rheumatology, Bone mineral, DXA, Aged, 80 and over, Hyperostosis, Diffuse Idiopathic Skeletal, Lumbar Vertebrae, business.industry, musculoskeletal, neural, and ocular physiology, Calcinosis, medicine.disease, musculoskeletal system, Vertebra, medicine.anatomical_structure, Cross-Sectional Studies, Diffuse idiopathic skeletal hyperostosis (DISH), Spinal Fractures, Original Article, Radiology, Vertebral fracture, business, Tomography, X-Ray Computed, QCT, 030217 neurology & neurosurgery, Osteoporotic Fractures
Abstract

Summary: Radiographs and spinal bone mineral density (BMD) were evaluated from 342 elderly men regarding possible effects of diffuse idiopathic skeletal hyperostosis (DISH) on vertebral fractures and densitometry measurements. Prevalent vertebral fractures were more frequent among men with DISH compared to men with no DISH even after fracture prevalence was adjusted for BMD. Paravertebral calcifications should be considered in patients with DISH when interpreting BMD measurements because both dual X-ray absorptiometry (DXA) and quantitative CT (QCT) densitometry may not be reliable. Introduction: The purpose of this study is to evaluate the prevalence of DISH in older men and its association with vertebral fractures and with BMD determined by DXA and QCT. Methods: Lateral radiographs of the spine were analyzed in a sample of 342 men aged ≥65 years participating in the MrOS Study concerning the presence and grade of DISH and vertebral fractures. Lumbar BMD was measured by both DXA (areal, grams per square centimeter) and QCT (volumetric, grams per cubic centimeter). The association between DISH, BMD, and presence of fractures was studied using χ2and t tests. Results: DISH was present in 52% (178/342) of the men. Men with DISH were older (mean, 75.1 vs 73.3, p

Published
2010
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3. Neue Techniken in der Osteoporosediagnostik

Author

A. S. Issever and Thomas M. Link

Subjects
Diagnostic Imaging, Gynecology, medicine.medical_specialty, Structure analysis, business.industry, Health economy, Image Enhancement, Trabecular bone, Practice Guidelines as Topic, Humans, Osteoporosis, Medicine, Radiology, Nuclear Medicine and imaging, Lumbar spine, Practice Patterns, Physicians', business
Abstract

In der vorliegenden Arbeit werden die aktuellen Entwicklungen und Anwendungen auf dem Gebiet der radiologischen Osteoporosediagnostik vorgestellt. Weiterentwicklungen bzgl. der dualen Rontgenabsorptiometrie (dual energy x-ray absorptiometry, DXA) beinhalten geometrische Parameter des proximalen Femurs wie die „hip axis length“ und neue Zielregionen (regions of interest, ROIs) zur Messung der Knochenmineraldichte (bone mineral density, BMD). Im Bereich der quantitativen Computertomographie (QCT) wurde gezeigt, dass nach Anwendung eines Konversionsfaktors die BMD auch aus klinischen abdominellen CTs ahnlich der QCT erfasst werden kann. Auch werden zunehmend volumetrische Methoden der BMD-Messung an der Wirbelsaule und dem proximalen Femur eingesetzt. In den letzten Jahren war im Rahmen des neu entwickelten Knochenqualitatskonzepts die Bestimmung der Knochenarchitektur ein zentraler Fokus. Die trabekulare Strukturanalyse mittels hochauflosender Verfahren wie der Magnetresonanztomographie und neuer computertomographischer Techniken wird daher in Zukunft fur die Osteoporose an Bedeutung zunehmen. Mit dem quantitativen Ultraschall steht eine relativ preiswerte Methode zur Diagnostik der Knochenqualitat zur Verfugung. Mit diesen neuen Techniken ist in den nachsten Jahren von einem Paradigmenwechsel in der quantitativen Osteoporosediagnostik auszugehen.

Published
2006
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4. Inclusive V production cross sections from 920 GeV fixed target proton-nucleus collisions

Author

Imma Riu, F. Sanchez, Hernan Wahlberg, L. Garrido, B. Bobchenko, N. Tesch, Brian Petersen, I. Kisel, C. Stegmann, C. B. Krauss, Mikhail Zavertyaev, O. Barsukova, J. L. Rosen, O. Steinkamp, Ulrich Werthenbach, D. Ryzhikov, F. Klefenz, D. Dujmic, I. Belotelov, H. Kapitza, H. Thurn, Yu. Pavlenko, P. Kreuzer, Jenny Ivarsson, Pietro Faccioli, M. Beck, I. Golutvin, V. Aushev, R. Wurth, T. Perschke, Mauro Villa, D. Broemmelsiek, M. Chmeissani, H. Sun, J. Yang, A. Michetti, Paul Edmund Karchin, A. Stanovnik, H. Fleckenstein, M. Ouchrif, S. Korpar, J. Luidemann, M. Spahn, K. Hofner, A. Kaoukher, Helmut Wolters, V. Saveliev, L. Sozuer, V. Vagnoni, J. Chamanina, A. Bogatyrev, Farid Ould-Saada, Kwong Lau, B. Lewende, M. Mevius, Yu.V. Mikhailov, L. Seybold, Ramon Miquel, J. D. Hansen, Søren Schmidt, Peter Robmann, Wolfgang Wagner, R. van Staa, R Stdenis, S. Hausmann, R. Chistov, D. Samtleben, B. Lomonosov, K. Berkhan, V. Rusinov, V. Eiges, M. Medinnis, D. C. Goulart, Dmitry Emeliyanov, S. Schaller, Z. Ke, I. Belyaev, A. Zhelezov, Samim Erhan, W. Ruckstuhl, A. Moshkin, V. Popov, Werner Hofmann, P.E. Schlein, J. Glass, R. F. Schwitters, Valery Pugatch, S. Essenov, J.J. Wang, D. Wegener, J. Rieling, Roberto Spighi, R. Mankel, A. Lange, D. Krücker, S. Nowak, D. Pose, J. Bastos, A. Belkov, Hyun-Chul Kim, N.N. Karpenko, W. Schmidt-Parzefall, Umberto Marini Bettolo Marconi, S. Steinbeck, V. Souvorov, A. Schreiner, Thomas Hamacher, B. Dolgoshein, W. Gradl, M. A. Pleier, C. Borgmeier, A. S. Schwarz, K. T. Knöpfle, B. Schwenninger, K. E. K. Gerndt, Antonio Zoccoli, Y. Guilitsky, Y. Vassiliev, U. Straumann, Yu.T. Kiryushin, I. Gorbounov, F. Saadi-Ludemannm, M. Dressel, M. Poli, D. Peralta, T. Lohse, I. Negri, M. Capeans, A. Bertin, Antonio Sbrizzi, Z. Zheng, S. Karabekyan, Y. Bagaturia, S. Ramachandran, G. Leffers, A. Vitale, I. Vukotic, S. Semenov, J. Zweizig, K. M. Danielsen, Benedetto Giacobbe, A. Gellrich, X. Dong, S. Shuvalov, Reinhard Männer, B. Schwingenheuer, B. Fominykh, F. Khasanov, M. Nörenberg, V. Rybnikov, M. Funcke, M. Walter, Nicola Semprini-Cesari, M. Bruinsma, M. Bargiotti, P. Pakhlov, C. van Eldik, H. Deppe, David Gascon, M. Hildebrandt, Kendall Reeves, I. C. Legrand, Vasco Amaral, S. Fourletov, M. Rietz, J. Shiu, O. Gouchtchine, J. Pyrlik, S. Solunin, W. Fallot-Burghardt, S. Keller, S. F. Takach, Christian Bauer, T. Glebe, Andrej Gorišek, D. Galli, H. Schröder, M. Ispiryan, M. Titov, G. Bohm, V. Bassetti, T. Fuljahn, Hermann Kolanoski, L. Matchikhilian, F Sciacca, Klaus Dehmelt, S. Gradl, R. Pernack, S. Issever, H. Itterbeck, V. Kochetkov, T. Zeuner, D. Skrk, I. Abt, B. X. Chen, M. Sang, P. Truöl, W. Hulsbergen, R. Baghshetsyan, P. J. Weyers, R. Wanke, J. Spengler, B. Schmidt, K. Ehret, Yuriy Pylypchenko, R. Pestotnik, Y. Jia, T. Buran, R. Loke, F. Sun, Ulrich Husemann, J. Flammer, M. Böcker, A. Pose, C. Jiang, A. Spiridonov, A. Christensen, M. Symalla, R. Eckmann, A. Golutvin, S. J. Aplin, João Carvalho, U. Trunk, M. S. Atiya, I. Tsakov, S. Nam, Olga Igonkina, V. Balagura, R. Muresan, M. Feuerstack-Raible, Y. Wang, C. Hast, G. Zech, A. Mohapatra, H. B. Dreis, M. Buchler, Mogens Dam, I. Arino, R. Mizuk, U. Schwanke, Laura Fabbri, S. De Castro, M. Danilov, P. Krizan, S. Masciocchi, A. H. Walenta, D. Goloubkov, K. Riechmann, B. Moshous, A. Lanyov, G. Medin, Z. Zhu, H. Deckers, A. Soldatov, T. Zivko, Marcus Hohlmann, A. Arefiev, F. Ratnikov, I. Tikhomirov, H. Albrecht, R. Zimmermann, I. Massa, A. Garcia, R. F. Harr, M. T. N. P. de Vera, T. Oest, D. Ressing, V. Egorytchev, A. Oliveira, A. Wurz, M. Bräuer, C. Rothe, H. D. Schultz, António Amorim, Peter Buchholz, T. Kvaratskheliia, Th.S. Bauer, T. Walter, M. Starič, A. Somov, M. Adams, E. Sexauer, M. Negodaev, Yang Liu, A. J. Schwartz, D. Stieler, Jose M Hernandez, M. Bruschi, M. Piccinini, A. Hoscher, G.J. Wagner, I. Siccama, M. Schmelling, S. Barsuk, S. Spratte, F. Eisele, M. Capponi, T. Hott, P. Conde, T. Jagla, S. Somov, Yu. Zaitsev, C. Cruse, C. Padilla, S. Xella-Hansen, A. Abyzov, and U. Uwer

Subjects
Physics, Physics and Astronomy (miscellaneous), Proton, 010308 nuclear & particles physics, Sigma, HERA, Lambda, 7. Clean energy, 01 natural sciences, Atomic mass, Nuclear physics, 0103 physical sciences, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, Nucleon, 010303 astronomy & astrophysics, Engineering (miscellaneous), HERA-B, Bar (unit)
Abstract

Inclusive differential cross sections dsigma(pA)/dx(F) and dsigma(pA)/dp(t)(2) for the production of K-S(0), Lambda, and (U) over bar particles are measured at HERA in proton-induced reactions on C, Al, Ti, and W targets. The incident beam energy is 920 GeV, corresponding to roots = 41.6 GeV in the proton-nucleon system. The ratios of differential cross sections dsigma(pA)(K-S(0))/dsigma(pA)(Lambda) and dsigma(pA)((U) over bar)/dsigma(pA) (Lambda) are measured to be 6.2 +/- 0.5 and 0.66 +/- 0.07, respectively, for x(F) approximate to -0.06. No significant dependence upon the target material is observed. Within errors, the slopes of the transverse momentum distributions da,Ald t also show no significant dependence upon the target material. The dependence of the extrapolated total cross sections sigma(pA) on the atomic mass A of the target material is discussed, and the deduced cross sections per nucleon sigma(pN) are compared with results obtained at other energies.

Published
2003
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5. J/psi production via chi(c) decays in 920 GeV pA interactions

Author

Samim Erhan, P. Kreuzer, M. Noerenberg, M. T. Nunez Pardo de Vera, R. Muresan, B. Schmidt, L. Garrido, H. B. Dreis, K. Berkhan, T. Hott, A. Stanovnik, U. Uwer, Sebastian Nowak, V. Rusinov, D. Wegener, R. Mizuk, C. Borgmeier, W. Gradl, M. Walter, D. Ryzhikov, Peter Robmann, M. Hildebrandt, S. Schmidt, B. A. Petersen, V. Saveliev, O. Gouchtchine, R. vanStaa, K. Riechmann, J. Yang, Pietro Faccioli, I. Massa, V. Aushev, J.D. Hansen, M. Spahn, C. Cruse, H. Wahlberg, D. Dujmic, J. Glaess, G. Bohm, C. Hast, Hermann Kolanoski, M. Dressel, A. Somov, G. Medin, J. Chamanina, J. Zweizig, P.E. Schlein, K. M. Danielsen, R. F. Schwitters, R. Eckmann, P. Conde, D. Kruecker, Igor Golutvin, M. Boecker, T. Jagla, S. Schaller, A. Moshkin, R. Wanke, A. Zhelezov, Yu. Zaitsev, Y. Pylypchenko, O. Steinkamp, T. Zivko, L. Sozuer, F. Sanchez, Jenny Ivarsson, M. Capponi, D. Goloubkov, K. T. Knöpfle, Kwong Lau, A. Gellrich, W. Schmidt-Parzefall, R. Spighi, Thomas Hamacher, Y. Vassiliev, I. Negri, G. Leffers, Rok Pestotnik, M. Symalla, S. J. Aplin, H. Schroeder, S. Essenov, A. Michetti, Paul Edmund Karchin, Y. Guilitsky, S. Steinbeck, S. Solunin, W. Fallot-Burghardt, U. Werthenbach, Yu.V. Mikhailov, A. Kaoukher, G.J. Wagner, B. Lewendel, David Gascon, S. F. Takach, M. Titov, T. Zeuner, A. H. Walenta, Y. Wang, J. Spengler, A. Belkov, L. Matchikhilian, O. Barsukova, S. Karabekyan, R Stdenis, U. Trunk, A. J. Schwartz, D. Stieler, Jose M Hernandez, I. Siccama, I. Abt, H. Itterbeck, Ramon Miquel, R. Baghshetsyan, D. C. Goulart, D. Galli, V. Popov, Werner Hofmann, Imma Riu, Mikhail Zavertyaev, B. Dolgoshein, V. Kochetkov, Ch. Rothe, B. Schwenninger, B. Giacobbe, S. Shuvalov, B. Bobchenko, M. Capeans, Yu. Pavlenko, Hyun-Chul Kim, A. Arefiev, S. De Castro, A. Wurz, Yu.T. Kiryushin, Laura Fabbri, L. Seybold, A. Lanyov, F. Klefenz, B. Lomonosov, V. Eiges, M. Feuerstack-Raible, C. Jiang, A. Spiridonov, V. Rybnikov, A. Golutvin, C. Padilla, W. Ruckstuhl, F. Ratnikov, I. Tikhomirov, S. Nam, Nicola Semprini-Cesari, Mauro Villa, M. Schmelling, M. A. Pleier, K. Höpfner, A. Christensen, Y. Bagaturia, Christian Bauer, D. Peralta, V. Bassetti, R. Wurth, B. Moshous, U. Schwanke, P. Truöl, C. B. Krauss, T. Oest, S. Barsuk, Samo Korpar, M. Poli, M. Adams, N. Tesch, U. Marconi, Fouzia Saadi-Lüdemann, Antonio Zoccoli, Jian Wang, M. Chmeissani, João Carvalho, Antonio Sbrizzi, J. Lüdemann, S. Spratte, E. Sexauer, D. Ressing, F. Khasanov, Robert Harr, S. Hausmann, I. Vukotic, S. Xella-Hansen, A. Bogatyrev, M. Bruinsma, U. Husemann, M. Negodaev, Kendall Reeves, T. Glebe, S. Fourletov, V. Souvorov, J. Bastos, T. Buran, I. Kisel, M. Buchler, I. Belyaev, Maurizio Piccinini, Y. Goloubkov, A. Gorisek, Dmitry Emeliyanov, T. Perschke, I. Tsakov, S. Gradl, A. Schreiner, S. Ramachandran, S. Keller, Vasco Amaral, X. Chen, F Sciacca, Klaus Dehmelt, Mogens Dam, X. Dong, R. Pernack, S. Issever, M. Sang, A. S. Schwarz, Th. S. Bauer, J. L. Rosen, A. Bertin, K. Ehret, N.N. Karpenko, D. Broemmelsiek, P. J. Weyers, R. Loke, K. E. K. Gerndt, Yunpeng Liu, Peter Buchholz, B. Schwingenheuer, A. Pose, W. Hulsbergen, Y. Jia, Z. Zheng, Marco Bruschi, A. Holscher, T. Walter, Thomas Lohse, J. Pyrlik, F. Eisele, A. Soldatov, Marcus Hohlmann, S. Somov, M. Ispiryan, J. Flammer, M. Bargiotti, B. Fominykh, Helmut Wolters, Farid Ould-Saada, M. Ouchrif, I. Arino, Wolfgang Wagner, M. Beck, Olga Igonkina, R. Zimmermann, P. Krizan, V. Balagura, H. Deckers, M. Danilov, I. Gorbounov, G. Zech, A. Mohapatra, T. Kvaratskheliia, R. Mankel, M. Funcke, I. C. Legrand, H. Albrecht, M. Starič, D. Skrk, V. Egorytchev, A. Oliveira, A. Lange, D. Pose, M. Braeuer, Mike Medinnis, C. van Eldik, Z. Ke, H. Deppe, J. Rieling, H. D. Schultz, Vincenzo Vagnoni, M. Rietz, C. Stegmann, A. Vitale, S. Semenov, António Amorim, T. Fuljahn, A. Garcia, R. Maenner, M. Mevius, H. Fleckenstein, R. Chistov, D. Samtleben, I. Belotelov, H. Kapitza, H. Thurn, Valery Pugatch, M. S. Atiya, S. Masciocchi, Z. Zhu, Geometry, (Astro)-Particles Physics, Mathematical Analysis, and Business Web and Media

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, 010308 nuclear & particles physics, 01 natural sciences, 7. Clean energy, High Energy Physics - Experiment, Nuclear physics, 0103 physical sciences, Radiative transfer, High Energy Physics::Experiment, 010306 general physics, Nuclear Experiment, HERA-B
Abstract

Using data collected by the HERA-B experiment, we have measured the fraction of J\psi's produced via radiative chi_c decays in interactions of 920 GeV protons with carbon and titanium targets. We obtained R_{\chi_c} = 0.32 \pm 0.06_{stat} \pm 0.04_{sys} for the fraction of J\psi from chi_c decays averaged over proton-carbon and proton-titanium collisions. This result is in agreement with previous measurements and is compared with theoretical predictions., Comment: 16 pages, 5 figs

Published
2003
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6. Measurement of the $b\overline{b}$ production cross section in 920 GeV fixed-target proton-nucleus collisions

Author

R. Spighi, Dmitry Emeliyanov, H. Fleckenstein, Jian Wang, R. van Staa, S. Hausmann, Y. Pylypchenko, T. Glebe, Antonio Zoccoli, R. Chistov, D. Samtleben, I. Siccama, Imma Riu, C. B. Krauss, B. Bobchenko, A. Hoscher, T. Zeuner, I. C. Legrand, W. Hulsbergen, Y. Jia, Z. Zheng, J. Flammer, R. Baghshetsyan, A. Bogatyrev, D. Broemmelsiek, Olga Igonkina, K. E. K. Gerndt, D. Skrk, Y. Vassiliev, M. Hildebrandt, V. Balagura, J. Bastos, G. Zech, A. Mohapatra, A. Belkov, Valery Pugatch, M. Bräuer, G.J. Wagner, H. Kapitza, M. A. Pleier, S. Gradl, A. Schreiner, Maurizio Piccinini, H. Thurn, Sebastian Nowak, V. Rusinov, Th. S. Bauer, B. X. Chen, R. Mizuk, V. Souvorov, T. Buran, D. Wegener, W. Gradl, S. Essenov, L. Seybold, Søren Schmidt, K. Riechmann, R. Pernack, S. Issever, S. Karabekyan, J. Rosen, Z. Ke, B. Lomonosov, J. Rieling, V. Eiges, H. Albrecht, Vincenzo Vagnoni, P. J. Weyers, R. Loke, S. Somov, M. Ouchrif, H. Wahlberg, M. Böcker, A. Pose, I. Belyaev, A. Lange, K. M. Danielsen, Jenny Ivarsson, M. Capponi, M. Atiya, V. Amaral, I. Massa, A. Abyzov, T. Oest, G. Medin, D. Galli, F. Eisele, Hyun-Chul Kim, Samim Erhan, T. Zivko, U. Marconi, S. Masciocchi, D. Pose, M. Symalla, S. J. Aplin, F. Sanchez, C. van Eldik, Marco Bruschi, H. Sun, A. Michetti, Paul Edmund Karchin, H. Deppe, A. Kaoukher, W. Ruckstuhl, D. Peralta, Z. Zhu, B. Moshous, Peter Robmann, S. De Castro, I. Vukotic, V. Egorytchev, A. Oliveira, M. Rietz, A. Arefiev, P. Kreuzer, J. Shiu, S. Xella-Hansen, David Gascon, U. Schwanke, Ramon Miquel, C. Rothe, H. D. Schultz, H. B. Dreis, K. Berkhan, T. Hott, Peter E. Schlein, J. Luidemann, Y. Wang, C. Stegmann, A. Vitale, Andrej Gorišek, A. Bertin, M. Walter, S. Semenov, C. Borgmeier, M. Poli, Helmut Wolters, Farid Ould-Saada, T. Fuljahn, L. Garrido, F. Ratnikov, I. Tikhomirov, C. Jiang, O. Barsukova, A. Spiridonov, A. Stanovnik, O. Gouchtchine, S. Shuvalov, F. Klefenz, Ulrich Werthenbach, D. Ryzhikov, Wolfgang Wagner, A. Christensen, Mike Medinnis, O. Steinkamp, S. Steinbeck, J. Glass, R. F. Schwitters, R. Pestotnik, M. T. N. P. de Vera, Robert Harr, V. Saveliev, G. Bohm, M. Spahn, Hermann Kolanoski, B. Schwingenheuer, Nicola Semprini-Cesari, M. Schmelling, Pietro Faccioli, V. Aushev, Y. Guilitsky, B. Dolgoshein, M. Capeans, J. Yang, R. Wanke, F. Sun, M. Mevius, Christian Bauer, Laura Fabbri, F. Saadi-Ludemannm, Thomas Hamacher, Antonio Sbrizzi, C. Padilla, U. Uwer, I. Belotelov, M. Nörenberg, T. Perschke, H. Schröder, A. Wurz, J. Zweizig, S. F. Takach, J. Chamanina, M. Titov, J. D. Hansen, X. Dong, B. A. A. Petersen, Mogens Dam, L. Sozuer, K. Hofner, P. Krizan, D. Goloubkov, Y. Bagaturia, I. Negri, G. Leffers, S. Barsuk, M. Beck, M. Bargiotti, B. Fominykh, S. Solunin, A. Soldatov, F Sciacca, Marcus Hohlmann, Klaus Dehmelt, W. Schmidt-Parzefall, W. Fallot-Burghardt, M. Ispiryan, D. Dujmic, I. Tsakov, L. Matchikhilian, S. Spratte, D. Ressing, R. Zimmermann, H. Itterbeck, V. Kochetkov, R. Eckmann, P. Conde, Igor Golutvin, T. Jagla, A. Garcia, N. N. Karpenko, A. Amorim, A. Moshkin, T. Walter, Ulrich Husemann, I. Arino, João Carvalho, Yu. Zaitsev, D. Krucker, H. Deckers, M. Danilov, C. Cruse, R Stdenis, M. Dressel, Peter Buchholz, A. H. Walenta, I. Gorbounov, R. Mankel, Kwong Lau, A. Gellrich, M. Funcke, T. Kvaratskheliia, R. Wurth, M. Chmeissani, B. Lewende, S. Ramachandran, A. S. Schwarz, R. Manner, A. J. Schwartz, A. Golutvin, S. Nam, M. Bruinsma, P. Pakhlov, Kendall Reeves, M. Sang, K. Ehret, I. Kisel, M. Buchler, F. Khasanov, Thomas Lohse, S. Fourletov, S. Keller, I. Abt, J. Spengler, U. Trunk, A. Lanyov, A. Zhelezov, K. T. Knöpfle, Yang Liu, U. Straumann, D. Stieler, Jose M Hernandez, B. Giacobbe, M. Adams, N. Tesch, E. Sexauer, Yu.V. Mikhailov, M. Negodaev, Mikhail Zavertyaev, D. C. Goulart, M. Starič, A. Somov, Yu. Pavlenko, S. Schaller, V. Popov, Werner Hofmann, J. Pyrlik, B. Schwenninger, Mauro Villa, Samo Korpar, Yu.T. Kiryushin, M. Feuerstack-Raible, V. Rybnikov, V. Bassetti, P. Truöl, B. Schmidt, R. Muresan, C. Hast, Geometry, (Astro)-Particles Physics, Mathematical Analysis, and Business Web and Media

Subjects
Physics, Particle physics, Physics and Astronomy (miscellaneous), Proton, 010308 nuclear & particles physics, Nuclear Theory, High Energy Physics::Phenomenology, Sigma, HERA, 01 natural sciences, Bottom quark, High Energy Physics - Experiment, Nuclear physics, Cross section (physics), 0103 physical sciences, High Energy Physics::Experiment, Production (computer science), Nuclear Experiment, 010306 general physics, Engineering (miscellaneous), HERA-B, Bar (unit)
Abstract

Using the HERA-B detector, the b-bbar production cross section has been measured in 920 GeV proton collisions on carbon and titanium targets. The b-bbar production was tagged via inclusive bottom quark decays into J/psi, by exploiting the longitudinal separation of J/psi->ll decay vertices from the primary proton-nucleus interaction. Both $e^+e^-$ and $\mu^+\mu^-$ channels have been reconstructed and the combined analysis yields the cross section $\sigma(b \bar b) = 32 ^{+14}_{-12} (stat) ^{+6}_{-7} (sys) nb/nucleon$., Comment: 22 pages, 10 Postscript figures

Published
2003
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7. Observation of coasting beam at the HERA proton-ring

Author

K Ehret, M Funcke, S Issever, T Jagla, T Lohse, S Schaller, S Spratte, M Symalla, Y Vassiliev, D Wegener, J Klute, and C Montag

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Proton, FOS: Physical sciences, HERA, Ring (chemistry), High Energy Physics - Experiment, Nuclear physics, High Energy Physics - Experiment (hep-ex), Physics::Accelerator Physics, High Energy Physics::Experiment, Nuclear Experiment, Instrumentation, Physics::Atmospheric and Oceanic Physics, Storage ring, Beam (structure)
Abstract

We present data collected with the HERA-B wire target which prove the existence of coasting beam at the HERA proton storage ring. The coasting beam is inherently produced by the proton machine operation and is not dominated by target effects., Comment: 17 pages (Latex), 12 figures (Enc. Postscript)

Published
2001
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8. [Radiological diagnosis of osteoporosis]

Author

A S, Issever and T M, Link

Subjects
Radiographic Image Enhancement, Absorptiometry, Photon, X-Ray Film, Humans, Osteoporosis, Tomography, X-Ray Computed
Abstract

Having at their disposal a wide range of imaging techniques, radiologists play a crucial role in the diagnostic evaluation of patients with osteoporosis. The radiological tests range from dual energy X-ray absorptiometry (DXA), which is the only reference method accepted by the WHO, to conventional radiographs for fracture characterization, to more recent techniques for analyzing trabecular structure, and the findings are decisive in initiating correct management of osteoporosis patients. This review provides an overview of established radiological techniques and an outline of new diagnostic approaches.

Published
2011

9. Lattice polymers: behaviour far from θ-conditions

Author

Ersin Yurtsever and S. Issever

Subjects
chemistry.chemical_classification, Polymers and Plastics, Chemistry, Computation, Organic Chemistry, Monte Carlo method, Thermodynamics, Polymer, Large range, Parameter space, Condensed Matter::Soft Condensed Matter, Lattice (order), Intramolecular force, Materials Chemistry, Scaling
Abstract

Two-dimensional Monte-Carlo simulations of lattice polymers were carried out employing Lennard-Jones (LJ) type intramolecular interactions. The shape-dependent properties of these polymers were studied over a large range of interaction parameters and temperatures. The variation of the critical constant was also analysed. Two-dimensional surfaces of sections were used to determine the portions of the parameter space which corresponded to θ-conditions. The behaviour of LJ polymers far from θ-conditions was determined. The investigations were facilitated by a simple scaling argument which resulted in considerable time savings in computations.

Published
1992
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10. Evaluation of correction methods for coil-induced intensity inhomogeneities and their influence on trabecular bone structure parameters from MR images

Author

Jenny, Folkesson, Roland, Krug, Janet, Goldenstein, Ahi S, Issever, Charles, Fang, Thomas M, Link, and Sharmila, Majumdar

Subjects
Aged, 80 and over, Male, Risk, Phantoms, Imaging, Equipment Design, Magnetic Resonance Imaging, Bone and Bones, Fractures, Bone, Cadaver, Image Processing, Computer-Assisted, Humans, Female, Femur, Tomography, X-Ray Computed, Aged
Abstract

Magnetic resonance (MR) imaging-based quantitative trabecular bone structure analysis has gained increasing interest in osteoporotic fracture risk assessment and treatment evaluation related to osteoporosis. In vivo MR images of anatomic regions such as the proximal femur and distal tibia are generally acquired with a surface coil in order to obtain sufficient sensitivity and resolution for quantification of the trabeculae. However, these coils introduce intensity inhomogeneities which affect the trabecular bone structure analysis. This work evaluates the applicability of a fully automatic coil correction by nonparametric nonuniform intensity normalization (N3) in the analysis of trabecular bone parameters. The ability to correct for coil-induced intensity inhomogeneity was evaluated ex vivo on proximal femur specimens scanned with both a surface coil and a volume coil, which allowed for a direct evaluation of the performance of the coil correction methods without any major confounding factors. In addition, trabecular bone parameter values were correlated with values from high-resolution peripheral computed tomography (HR-pQCT) scans, and the reproducibility of trabecular bone parameters was evaluated in an in vivo study of repeat hip MR scans. The trabecular bone parameters determined from MR surface coil scans processed with the N3 coil correction method showed significant correlation (p0.05) with corresponding values from homogeneous intensity data in the ex vivo study. This can be compared to the correlation without coil correction (p0.5), and coil correction using low-pass filtering (LPF) (p0.53). The in vivo interscan variability was reduced from 8.9% to 12.8% using LPF-based to 3.6%-8.4% (CV) using N3 coil correction; hence the results showed that N3 is advantageous to LPF-based coil correction. No significant differences in correlation to HR-pQCT data were found for the coil correction methods. The significant correlations with volume coil data and high reproducibility of the N3 processed data imply that N3 coil correction preserve image information while accurately correcting for coil-induced intensity inhomogeneities, which makes it suitable for quantitative analysis of trabecular bone structure from MR images acquired with surface coils.

Published
2009

11. A micro-computed tomography study of the trabecular bone structure in the femoral head

Author

A S, Issever, A, Burghardt, V, Patel, A, Laib, Y, Lu, M, Ries, and S, Majumdar

Abstract

The goal of this study was to characterize the trabecular microarchitecture of the femoral head using micro-computed tomography (ICT). Femoral head specimens were obtained from subjects following total hip replacement. Cylindrical cores from the specimens were scanned to obtain 3-D images with an isotropic resolution of 26 Im. Bone structural parameters were evaluated on a per millimeter basis: relative bone volume (BV/TV), trabecular number (Tb.N), thickness (Tb.Th) and separation (Tb.Sp), structure model index (SMI), and connectivity (Conn.D). The ICT data show that the first two millimeters, starting at the joint surface, are characterized by more plate-like trabeculae, and are significantly denser than the underlying trabecular bone. Regional differences in the trabecular architecture reveal that the superior pole has significantly higher BV/TV, Tb.N and Tb.Th values, with lower Tb.Sp compared to the inferior and side poles. Because subchondral bone is essential in the load attenuation of joints, the difference in bone structure between the subchondral and trabecular bone might arise from the different functions each have within joint-forming bones. The denser trabecular structure of the superior pole as compared to the inferior pole can be interpreted as a functional adaptation to higher loading in this area.

Published
2005

12. Transverse beam tail shaping in HERA-B by means of tune modulation

Author

S. Issever, K. Ehret, M. Funcke, and C. Montag

Subjects
Physics, Luminosity (scattering theory), ZEUS (particle detector), Proton, law.invention, Nuclear physics, Transverse plane, law, Modulation, Physics::Accelerator Physics, High Energy Physics::Experiment, Atomic physics, Collider, Beam (structure), HERA-B
Abstract

The HERA-B experiment utilizes an internal wire target in the halo of the stored proton beam in order to study CP violation. As operational experience shows, interaction rates tend to be extremely sensitive to tiny orbit jitter amplitudes. In order to stabilize these interaction rates, various methods have been studied to increase diffusion in the transverse proton beam tails without affecting the luminosity at the electron-proton collider experiments ZEUS and H1. Tune modulation was found to be a promising method for this task. The present status of these experiments will be reported.

Published
2002
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14. Imidazolidin-4-ones via (3+2) cycloadditions of aza-oxyallyl cations onto ( E )- N arylideneanilines.

Author

Eyilcim O, Issever S, Ocal N, Gronert S, and Erden I

Abstract

In the course of our studies on the chemistry of oxyallyl species we uncovered a new (3+2) cycloaddition of aza-oxyallyl systems, generated in situ from N -benzyloxy-2-chloroamides in the presence of NEt 3 , onto N -arylimines yielding imidazolidin-4-ones in moderate to good yields. The cycloadditions are regioselective. Computational modelling using DFT at the M062×/6-311+G** level is in support the observed regioselectivities. Although the path to the trans imidazolin-4-one is favored, the cis product is preferred by almost 8 kcal/mol and could be formed by base-catalyzed epimerization. All products were isolated by chromatography and characterized by means of their FTIR, NMR and HRMS data.

Published
2018
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15. Ligase-independent cloning of amylase gene from a local Bacillus subtilis isolate and biochemical characterization of the purified enzyme.

Author

Tuzlakoglu Ozturk M, Akbulut N, Issever Ozturk S, and Gumusel F

Subjects
Ammonium Compounds pharmacology, Amylases chemistry, Amylases isolation & purification, Chelating Agents pharmacology, Enzyme Stability, Escherichia coli genetics, Genome, Bacterial genetics, Hydrogen-Ion Concentration, Metals pharmacology, Polymerase Chain Reaction, Recombinant Proteins chemistry, Recombinant Proteins genetics, Recombinant Proteins isolation & purification, Recombinant Proteins metabolism, Substrate Specificity, Surface-Active Agents pharmacology, Temperature, Amylases genetics, Amylases metabolism, Bacillus subtilis enzymology, Bacillus subtilis genetics, Cloning, Molecular methods
Abstract

Five hundred ninety-seven bacterial isolates from Turkish hot spring water sources were screened for their ability to produce extracellular α-amylase. Among them, a high enzyme-producing Bacillus subtilis isolate, A28, was selected, and its α-amylase gene was cloned and expressed in Escherichia coli by a ligase-independent method. α-Amylase from the recombinant strain was purified to homogeneity by Q-Sepharose anion exchange and Sephacryl S-100 gel filtration chromatographies. The final yield of the enzyme was about 22.5 % of the initial activity, with a 16.4-fold increase in specific activity compared with the culture lysate. The optimum temperature and pH of the enzyme were 70 °C and 6.0, respectively. The enzyme was highly active at acidic-neutral pH range of 4.5-7.0. The amy28 α-amylase retained 100 % of its activity after incubation at 50 °C for 90 min. Co(+2), Cu(2+), Fe(2+), Fe(3+), Ni(+2), and Zn(+2) caused significant inhibition in enzyme activity, which was not affected by Na(+), Mg(2+), Li(+), and Ba(2+). The activity was inhibited about 70 % upon treatment of the enzyme with 10 mM ethylenediaminetetraacetic acid. However, Ca(2+) ions known as high temperature stabilizer for other amylases did not stimulate the activity of the enzyme. Due to pH stability and thermostability of the recombinant amylase, this enzyme may be suitable in starch processing, brewing, and food industries.

Published
2013
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