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11.
Proton relaxation times in human red bone marrow by volume selective magnetic resonance spectroscopy
F. Schick H. Bongers W. -I. Jung B. Eismann M. Skalej H. Einsele O. Lutz C. Claussen 《Applied magnetic resonance》1992,3(6):947-963
In hematological diseases the composition of red bone marrow shows alterations. The relaxation timesT 1 andT 2 of water and lipids in human hemopoietic bone marrow of 14 normal volunteers and 10 patients with acute leukemia and bone marrow carcinosis are determined using a double spin echo spectroscopy sequencein vivo. The volumes of interest (VOI) of (13 mm)3 in the center of vertebral bodies are examined using different measurement parameters. ForT 1 measurements an inversion-recovery method is used.T 2 is evaluated from spectra with differentTE. T 1 (water) is found in a range between 1000 and 1700 ms,T 1 (lipids) in a range between 260 and 320 ms in healthy volunteers.T 2 (water) is determined between 32 and 65 ms. In some cases phase distortions of the water signals occur in the spectra. Water flow within the VOI may be a possible reason.T 2 (lipids) is evaluated between 73 and 91 ms. The patients with acute leukemia exhibit clearly reduced lipid signals in their spectra. Lipid relaxation times could not be determined in these cases.T 2 (water) is prolonged in acute leukemia to 51–98 ms.T 1 (water) was not significantly different from values of healthy volunteers in our measurements. Results are discussed in comparison to relaxometric data from imaging and STEAM spectroscopic methods of other authors. 相似文献
12.
Katharina Habermann Lutz Habermann Paul Rosenthal 《Calculus of Variations and Partial Differential Equations》2007,30(2):137-152
A Yang–Mills theory in a purely symplectic framework is developed. The corresponding Euler–Lagrange equations are derived
and first integrals are given. We relate the results to the work of Bourgeois and Cahen on preferred symplectic connections. 相似文献
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O. Lutz R. Swinne J. C. Brünnich und F. Smith 《Fresenius' Journal of Analytical Chemistry》1913,52(3-4):226-227
Ohne Zusammenfassung 相似文献
15.
The π? p→e + e ? n and π+ n→e + e ? p reaction cross sections are calculated below and in the vicinity of the vector-meson (?0,ω) production threshold. These processes are largely responsible for the emission of e +e? pairs in pion-nucleus reactions and contribute to the dilepton spectra observed in relativistic heavy ion collisions. They are dominated by the decay of low-lying baryon resonances into vector-meson-nucleon channels. The vector mesons materialize subsequently into e + e? pairs. Using πN→?0 N and πN→ωN, amplitudes calculated in the center of mass energy interval 1.4 < √s<1.8 GeV, we compute the π? p→e + e ? n and π+ n→e + e ? p reaction cross sections in these kinematics. Below the vector-meson production threshold, the π0?ω interference in the e + e? channel appears largely destructive for the π? p→e + e ? n cross section and constructive for the π+ n→e + e ? p cross section. The pion beam and the HADES detector at GSI offer a unique possibility to measure these effects. Such data would provide strong constraints on the coupling of vector-meson-nucleon channels to low-lying baryon resonances. 相似文献
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Ohne Zusammenfassung 相似文献
20.
H. Fawcett S. Barlag H. Becker E. Belau T. Böhringer M. Bosman V. Castillo V. Chabaud D. Bucholz C. Damerell C. Daum G. De Rijk H. Dietl S. Gill A. Gillman R. Gilmore T. Gooch P. Gras Z. Hajduk E. Higon B. Hyams D. Kelsey J. Kemmer R. Klanner U. Kötz S. Kwan B. Lücking G. Lütjens G. Lutz J. Malos W. Männer E. Neugebauer H. Palka M. Pepé G. Polok J. Richardson M. Rozanska K. Rybicki H. Seebrunner U. Stierlin R. Tapper H. Tiecke M. Turala G. Waltermann S. Watts P. Weilhammer F. Wickens L. Wiggers A. Wylie T. Zeludziewicz ACCMOR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1990,46(4):513-519
The production of the neutralK ? (892) resonances by 200 GeVK ? andπ ? has been studied over the kinematic range 0.0<x f<1.0 andp t 2 <5.0 GeV2. Longitudinal and transverse momentum distributions are presented. In addition the decay angular distributions inK ? fragmentation to \(\bar K^{0*} \) have been investigated. 相似文献