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1.
Reinhard Oertel Norman Arenz Sten Gunnar Zeitz Jörg Pietsch 《Biomedical chromatography : BMC》2015,29(8):1290-1296
With screening methods in the legal medicine drugs were often detected in autopsy material. In this study the antiarrhythmic and the local anesthetic drug lidocaine could be proved in fifty‐one cases and determined in different autopsy materials. For the first time the comparison of so many distribution patterns of lidocaine in human compartments was possible. A liquid‐liquid extraction procedure, a standard addition method and LC/MS/MS were used for analytics. The measured concentrations in blood were in the therapeutic range or lower. The time between lidocaine application and death was given in twenty‐nine cases. These data were very helpful to estimate and interpret the distribution process of lidocaine between application and death. This time exerted a crucial influence on the distribution of lidocaine in the compartments. Most of the intravenous applicated lidocaine was found in heart blood after a very short time of distribution. Afterwards the highest concentrations were measured in brain. Later the highest concentration was found in the kidney samples or in urine. If the time between lidocaine application and death is known, the results of this study can be used to deepen the knowledge of its pharmacokinetics. If this time is unknown, the circumstances and the causes of death can be better explained. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
2.
Dr. Agnes Kütt Prof. Dr. Gunnar Jeschke Dr. Lauri Toom Dr. Jaak Nerut Prof. Christopher A. Reed 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(41):8871-8874
Hydride abstraction from diarylamines with the trityl ion is explored in an attempt to generate a stable diarylnitrenium ion, Ar2N+. Sequential H-atom abstraction reactions ensue. The first H-atom abstraction leads to intensely colored aminium radical cations, Ar2NH.+, some of which are quite stable. However, most undergo a second H-atom abstraction leading to ammonium ions, Ar2NH2+. In the absence of a ready source of H-atoms, a unique self-abstraction reaction occurs when Ar=Me5C6, leading to a novel iminium radical cation, Ar=N.+Ar, which decays via a second self H-atom abstraction reaction to give a stable iminium ion, Ar=N+HAr. These products differ substantially from those derived via photochemically produced diarylnitrenium ions. 相似文献
3.
Jörg Wolfram Anselm Fischer Andreas Brenig Dr. Daniel Klose Prof. Dr. Jeroen Anton van Bokhoven Dr. Vitaly L. Sushkevich Prof. Dr. Gunnar Jeschke 《Angewandte Chemie (International ed. in English)》2023,62(34):e202303574
Cu-exchanged mordenite (MOR) is a promising material for partial CH4 oxidation. The structural diversity of Cu species within MOR makes it difficult to identify the active Cu sites and to determine their redox and kinetic properties. In this study, the Cu speciation in Cu-MOR materials with different Cu loadings has been determined using operando electron paramagnetic resonance (EPR) and operando ultraviolet-visible (UV/Vis) spectroscopy as well as in situ photoluminescence (PL) and Fourier-transform infrared (FTIR) spectroscopy. A novel pathway for CH4 oxidation involving paired [CuOH]+ and bare Cu2+ species has been identified. The reduction of bare Cu2+ ions facilitated by adjacent [CuOH]+ demonstrates that the frequently reported assumption of redox-inert Cu2+ centers does not generally apply. The measured site-specific reaction kinetics show that dimeric Cu species exhibit a faster reaction rate and a higher apparent activation energy than monomeric Cu2+ active sites highlighting their difference in the CH4 oxidation potential. 相似文献
4.
Julie E. Bolding Alexander L. Nielsen Iben Jensen Tobias N. Hansen Line A. Ryberg Samuel T. Jameson Pernille Harris Günther H. J. Peters John M. Denu Joseph M. Rogers Christian A. Olsen 《Angewandte Chemie (International ed. in English)》2023,62(49):e202314597
The sirtuins are NAD+-dependent lysine deacylases, comprising seven isoforms (SIRT1–7) in humans, which are involved in the regulation of a plethora of biological processes, including gene expression and metabolism. The sirtuins share a common hydrolytic mechanism but display preferences for different ϵ-N-acyllysine substrates. SIRT7 deacetylates targets in nuclei and nucleoli but remains one of the lesser studied of the seven isoforms, in part due to a lack of chemical tools to specifically probe SIRT7 activity. Here we expressed SIRT7 and, using small-angle X-ray scattering, reveal SIRT7 to be a monomeric enzyme with a low degree of globular flexibility in solution. We developed a fluorogenic assay for investigation of the substrate preferences of SIRT7 and to evaluate compounds that modulate its activity. We report several mechanism-based SIRT7 inhibitors as well as de novo cyclic peptide inhibitors selected from mRNA-display library screening that exhibit selectivity for SIRT7 over other sirtuin isoforms, stabilize SIRT7 in cells, and cause an increase in the acetylation of H3 K18. 相似文献
5.
A variety of different low-coordinate iron selenide complexes is reported. These are obtained by reaction of the linear iron(I) silylamide K{18c6}[Fe(N(Dipp)SiMe3)2] (Dipp=2,6-diisopropylphenyl) with red selenium. Careful adjustment of the reaction conditions results in the formation of unique low-coordinate selenido iron complexes, namely a monoselenide bridged [2Fe−1Se]2+ complex, as well as mononuclear iron per- and triselenides. Further, C−H bond activation of one of the silylamide ligands by a putative terminal iron monoselenide is observed. 相似文献
6.
Christian Schneider Dr. Serhiy Demeshko Prof. Dr. Franc Meyer Dr. C. Gunnar Werncke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(20):6348-6353
A [Fe-S-Fe] subunit with a single sulfide bridging two low-coordinate iron ions is the supposed active site of the iron-molybdenum co-factor (FeMoco) of nitrogenase. Here we report a dinuclear monosulfido bridged diiron(II) complex with a similar complex geometry that can be oxidized stepwise to diiron(II/III) and diiron(III/III) complexes while retaining the [Fe-S-Fe] core. The series of complexes has been characterized crystallographically, and electronic structures have been studied using, inter alia, 57Fe Mössbauer spectroscopy and SQUID magnetometry. Further, cleavage of the [Fe-S-Fe] unit by CS2 is presented. 相似文献
7.
Grégoire Sieg Quentin Pessemesse Sascha Reith Stefan Yelin Prof. Dr. Christian Limberg Prof. Dr. Dominik Munz Dr. C. Gunnar Werncke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(67):16760-16767
Carbonyl and iminyl based radical anions are reactive intermediates in a variety of transformations in organic synthesis. Herein, the isolation of ketyl, and more importantly unprecedented ketiminyl and aldiminyl radical anions coordinated to cobalt and iron complexes is presented. Insights into the electronic structure of these unusual metal bound radical anions is provided by X-Ray diffraction analysis, NMR, IR, UV/Vis and Mössbauer spectroscopy, solid and solution state magnetometry, as well as a by a detailed computational analysis. The metal bound radical anions are very reactive and facilitate the activation of intra- and intermolecular C−H bonds. 相似文献
8.
D. Mathur N. Rana C. E. Olsen V. S. Parmar A. K. Prasad 《Journal of heterocyclic chemistry》2015,52(3):701-710
A small library of thirty‐two 2′‐triazolyl uridine and 2′‐triazolyl‐5‐methyluridine has been synthesized by Cu(I)‐catalyzed condensation of 2′‐azido‐2′‐deoxyuridine and 2′‐azido‐2′‐deoxy‐5‐methyluridine with different alkynes and aryl propargyl ethers in almost quantitative yields. Triazolo‐nucleoside conjugates, which can be evaluated for different biological activity for suitable drug development, were unambiguously identified on the basis of 1H NMR, 13C NMR, IR, and HRMS data analysis. These compounds have been synthesized for the first time and have not been reported in the literature earlier. 相似文献
9.
Thermodynamics is developed for a class of thermo-hypo-elastic materials. It is shown that materials of this class obey the laws of thermodynamics, but are not elastic.
Table of Symbols
Latin Letters A ijkl tensor-valued function of t ij appearing in hypo-elastic constitutive relation - B ijkl another tensor-valued function. See equation (4.2) - B the square of - d ij rate of deformation tensor - d ij deviator of rate of deformation - f, k functions of pressure, p - g, h functions of the invariant - p pressure - q i heat flux vector - s ij stress deviator - ij co-rotational derivative of stress deviator - t time - t 1 t 2 specific values of time - t ij stress tensor - t ij 0 a specific value of stress - T Temperature - T 0 a specific value of temperature - u i velocity - V(t) a material volume as a function of time, t - V 0 a material volume at a reference configuration - W work (W = work done in a deformation—section 5) Sript Letters Specific internal energy - Specific Helmholtz free energy - G Specific Gibbs function Greek Letters an invariant of the stress deviator—see eq. (2.4) - ij kroneker delta - (W = work done in a deformation—section 5) - specific entropy - hypo-elastic potential - hypo-elastic potential - mass density - 0 mass density in a reference configuration - specific volume = 1/ - a function of p - ijkl a constant tensor—see eq. (2.5) - –G/ - ij rate of rotation tensor This work is dedicated to Jerald L. Ericksen, without whose influence it would not have been possible 相似文献10.
Toke Meier Carlsen Søren Eilers Eduard Ortega Gunnar Restorff 《Journal of Mathematical Analysis and Applications》2019,469(2):1088-1110
We give conditions for when continuous orbit equivalence of one-sided shift spaces implies flow equivalence of the associated two-sided shift spaces. Using groupoid techniques, we prove that this is always the case for shifts of finite type. This generalises a result of Matsumoto and Matui from the irreducible to the general case. We also prove that a pair of one-sided shift spaces of finite type are continuously orbit equivalent if and only if their groupoids are isomorphic, and that the corresponding two-sided shifts are flow equivalent if and only if the groupoids are stably isomorphic. As applications we show that two finite directed graphs with no sinks and no sources are move equivalent if and only if the corresponding graph -algebras are stably isomorphic by a diagonal-preserving isomorphism (if and only if the corresponding Leavitt path algebras are stably isomorphic by a diagonal-preserving isomorphism), and that two topological Markov chains are flow equivalent if and only if there is a diagonal-preserving isomorphism between the stabilisations of the corresponding Cuntz–Krieger algebras (the latter generalises a result of Matsumoto and Matui about irreducible topological Markov chains with no isolated points to a result about general topological Markov chains). We also show that for general shift spaces, strongly continuous orbit equivalence implies two-sided conjugacy. 相似文献