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  • Author: Sabine Becker x
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Intermolecular activation of carbon-hydrogen bonds has been accomplished by reduction with sodium amalgam of (sip3)(Me3P)RuCl2, 1, [“sip3” = MeSi(CH2PMe)2)3] in aromatic hydrocarbons, such as benzene and substituted derivatives thereof. In these reactions, the 16e equivalent (sip3XMe3P)Ru(O) thus generated exhibits a preference for insertion across the unhindered metaand para-C-H bonds to produce complexes of composition (sip3)(Me3P)RuH(C6H3RR′) [R = R′ = H, 2; R = H, R′ = CH3, 3; R = R′ = CH3 (3,4-xylyl), 4; R = R′ = CH3 (3,5-xylyl), 5; R = H, R′ = CF3, 6], of which 3, 4, and 6 were isolated as mixtures of meta/para-isomers and Ru-aryl rotamers, respectively. Reaction of the phenyl hydride 2 with 4-MeC6H4NCE (E = O, S) leads to insertion of the heteroallenes into the Ru-Η bond to give (sip3)(Me3P)Ru[N(C6H4Me-4)C(O)H]C6H5, 8, and (sip3)(Me3P)Ru[SC(=NC6H4Me-4)H]C6H5, 10, as the primary products. While the latter forms (sip3), 11, by loss of PMe3, the former reacts with another molecule of isocyanate to afford the acyl compound (sip3)9, as the ultimate product. Treatment of 2 with CO2 results in the formation of a carbonato derivative, (sip3)(Me3P)Ru(O2CO), 7.

Essays and Letters of Carl L. Becker

Definitions for the terms "metallome" and "metallomics" are proposed. The state of the art of analytical techniques and methods for systematic studies of metal content, speciation, localization, and use in biological systems is briefly summarized and critically evaluated.

Abstract

One fundamental component of early warning systems for natural hazards is displacement monitoring. Spaceborne SAR Interferometry has proven to be a powerful remote sensing tool for this task. Lately new ground-based SAR instruments are available. Their application field is wide and they combine high resolution and accuracy with the classical benefits of remote sensing techniques.

Here, the principles of the microwave interferometer IBIS are presented, as well as its advantages and disadvantages compared to common monitoring techniques. IBIS can be operated in two modes: IBIS-S is a microwave interferometer capable of high frequency displacement monitoring of buildings and structures (up to 200 Hz); IBIS-L is a ground-based SAR for long-term displacement monitoring of buildings and natural phenomena as landslides, glaciers, etc.

Exemplary three applications are presented: the use of IBIS-S for dynamic monitoring of a chimney; the use of IBIS-L for displacement monitoring in an active quarry and the long-term operation of IBIS-L as part of a “Volcano Fast Response System” (VFRS) on an active volcano.

Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has become established as a very efficient and sensitive trace, ultratrace, and surface analytical technique in the life sciences. We have developed a new analytical imaging technique using LA-ICP-MS to study element distribution in biological tissues. Nowadays, LA imaging ICP-MS using double-focusing sector field (LA-ICP-SFMS) or quadrupole-based mass spectrometers (LA-ICP-QMS) can be applied as an exciting tool providing new information on the pathophysiology, pharmacology, and toxicology of elements of interest in biological systems. The quantitative determination of elements (e.g., Cu, Fe, Zn, Se, and others) in biological tissues is of growing interest especially in brain research (e.g., for studying neurodegenerative diseases such as Alzheimer's or Parkinson's disease). LA-ICP-SFMS was employed to produce images of detailed regionally specific element distributions in thin tissue sections of different sizes (such as control human or rat brain tissues or tumor regions). In addition, imaging MS using LA-ICP-QMS was applied to study the uptake and transport of nutrient and toxic elements in plant tissues.

Besides the quantitative imaging of essential and toxic elements in tissues, powerful analytical techniques are also required for the determination and characterization of phosphoproteins and metal-containing proteins within a large pool of proteins, after electrophoretic separation (e.g., blue native, BN and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, SDS-PAGE) into 1D and 2D gels. LA-ICP-MS was used to detect metalloproteins in protein bands of 1D gels or protein spots separated after 2D gel electrophoresis (2D-GE). In addition to elemental determination by LA-ICP-MS, matrix-assisted laser desorption/ionization (MALDI)-MS was employed to identify metal-containing proteins. Recent progress will be discussed in applying LA-ICP-MS in the life sciences, including the imaging of thin slices of tissue and applications in proteome analysis in combination with MALDI-MS to investigate phosphoproteins and metal-containing proteins.