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31.
Emrys A. Jones Nicholas P. Lockyer John C. Vickerman 《International journal of mass spectrometry》2007,260(2-3):146
Recent developments in desorption/ionisation mass spectrometry techniques have made their application to biological analysis a realistic and successful proposition. Developments in primary ion source technology, mainly through the advent of polyatomic ion beams, have meant that the technique of secondary ion mass spectrometry (SIMS) can now access the depths of information required to allow biological imaging to be a viable option.Here the role of the primary ion C60+ is assessed with regard to molecular imaging of lipids and pharmaceuticals within tissue sections. High secondary ion yields and low surface damage accumulation are demonstrated on both model and real biological samples, indicating the high secondary ion efficiency afforded to the analyst by this primary ion when compared to other cluster ion beams used in imaging. The newly developed 40 keV C60+ ion source allows the beam to be focused such that high resolution imaging is demonstrated on a tissue sample, and the greater yields allow the molecular signal from the drug raclopride to be imaged within tissue section following in vivo dosing.The localisation shown for this drug alludes to issues regarding the chemical environment affecting the ionisation probability of the molecule; the importance of this effect is demonstrated with model systems and the possibility of using laser post-ionisation as a method for reducing this consequence of bio-sample complexity is demonstrated and discussed. 相似文献
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Consider a semigroup generated by matrices associated with an edge-coloring of a strongly connected, aperiodic digraph. We
call the semigroup Lie-solvable if the Lie algebra generated by its elements is solvable. We show that if the semigroup is
Lie-solvable then its kernel is a right group. Next, we study the Lie algebra generated by the kernel. Lie algebras generated
by two idempotents are analyzed in detail. We find that these have homomorphic images that are generalized quaternion algebras.
We show that if the kernel is not a direct product, then the Lie algebra generated by the kernel is not solvable by describing
the structure of these algebras. Finally, we discuss an infinite class of examples that are shown to always produce strongly
connected aperiodic digraphs having kernels that are not right groups. 相似文献
34.
The binding of heterobidentate P∧S ligands introduces metal-centered chirality to the planar chiral parent complex Ru(η6:η1-NMe2C6H4C6H4PCy2)Cl2. Observed diastereomeric ratios for the kinetic product vary dramatically depending upon ring size of the chelate formed with the P∧S ligand. The complexes epimerize very slowly to thermodynamic product ratios that are substantially different from the kinetic product ratios. 相似文献
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