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111.
A facile chemical synthesis of 1-methylpseudouridine has been accomplished by direct methylation of pseudouridine. 相似文献
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E. A. Maier M. L. Sargentini-Maier F. Rastegar C. Christophe C. Ruch R. Heimburger M. J. F. Leroy 《Fresenius' Journal of Analytical Chemistry》1988,331(1):58-60
Summary The energy dispersive X-ray fluorescence spectrometer (EDXRF) developped together with the Siemens Company (FRG) allows to perform rapid multi-elemental analysis of biological fluids without pretreatment of the samples. The performance of this technique and its features are reported in two different fields: blood analysis and pulmonary investigations. Blood and plasma analysis were performed for more than 2500 patients and a statistical treatment of the data lead to the normal concentrations of trace elements Se, Rb, Cu, Zn, Fe, Ca, Br, K. Toxic elements such as Hg or Pb and also drugs like Au and Pt compounds can be detected even after a long period after treatment. To illustrate the performance of the spectrometer we report the influence of Cis-Pt treatment on the trace element concentrations in plasma of patients with anemia.The EDXRF spectrometry was also used to investigate the inorganic composition of the broncho-alveolar lavage fluids. After determination of the normal concentration range, it was possible to characterize some typical pulmonary diseases due to occupational exposure. Some examples of detected pneumoconiosis and for some patients the presence in the alveoli of elements due to special medication (Amiodarone, Aurothiopropanol-sulfonate) are mentioned.Other fields are being investigated such as: follow-up of Mn dependent enzymes in neuronal and glial cells in culture; origin of lead in dental tissues or composition of lyophilized food powders. They will be briefly discussed.
Energie-dispersive Röntgenfluorescenz in der biomedizinischen Analyse相似文献
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In this paper we present a critical discussion of perturbation theory in the temporal gauge in the framework of the finite-time formulation given by Rossi and Testa.We find an interesting intrinsic freedom in the definition of the Feynman rules which nevertheless can be unambiguously derived. We compute the vacuum expectation value of a rectangular Wilson loop to order g4, proving the expected exponentiation of its time dependence. 相似文献
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Theoretical expressions and their approximate formulae for the intensities of light diffracted by two adjacent ultrasonic beams are discussed and compared with experimental data for the case when the second beam is an even harmonic of the first (fundamental). In the special case of the fundamental and its second or fourth harmonic, relatively simple formulae are found for the first and second diffraction orders describing the variation of light intensity with phase shift and intensity ratio.The approximate formulae describe the experiments satisfactorily only for small values of ζ1 and αn. For higher values the exact formulae give better agreement. Only the Raman-Nath region is considered. 相似文献
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A theoretical study of substituent effects on 1,3-dipolar cycloadditions has been carried out by the LCAO-SCF-MO method. The potential energy hypersurfaces for ten reactions and the electronic and energetic properties of the transition states have been investigated. 相似文献