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W Görner

Publications and source records attributed to W Görner.

9 recordsLinked to original sources
PubMed2001

Determination of elements by nuclear analytical methods.

The working principle of nuclear analytical methods (NAMs) is not influenced by the chemical bond. Consequently, they are independent counterparts to the well-known chemical procedures. NAMs obey fundamental laws or can be described and understood thoroughly. This qualifies them as candidates for reference methods. Although following similar nuclear reaction schemes, they comprise bulk analyzing capability (neutron and photon activation analysis) as well as detection power in surface near regions of solids (ion beam techniques). Prominent features of NAMs are sensitivity, selectivity, multielement determination and linearity of the calibration function covering a concentration range of several orders of magnitude. Moreover, ion beam techniques allow depth profiling with nm-resolution in several cases while the ion microprobe additionally offers a lateral resolution in the micron-scale. As NAMs require expensive apparatus (nuclear reactor, accelerator in radioactive control areas) their availability is restricted to a small number of suitably equipped institutes. However, they are able to solve complex analytical tasks, take part in key comparisons and play an essential role in the certification of reference materials.

Journal Article↗
PubMed2001

Characterization of neutron transmuted zinc traces in pure copper materials by isotope dilution mass spectrometry.

The neutron transmutation doping (NTD) of highly pure copper with zinc was investigated as a promising means of achieving controlled gradation of the zinc content in the range 1-20 microg g(-1). The doping process leads to the enrichment of two stable isotopes 64Zn and 66Zn in a ratio which differs from that of natural isotopic distribution. Mass spectrometric investigations by thermal ionization mass spectrometry (TIMS) were performed to validate the results obtained by gamma spectrometry. The investigations included both determination of the isotopic ratios of the doped zinc isotopes and the analysis of the accumulated zinc contents by isotope dilution (ID) analysis. Thereby a sample-specific correction of the blank could be performed because the isotope 68Zn was not influenced, because of the transmutation process. The results obtained by TIMS prove the strict proportionality of the doped zinc content, in the range 5 to 20 microg g(-1), to the neutron fluence. Comparison with gamma spectrometric results showed a very good agreement within the uncertainties.

Journal Article↗
PubMed1999

Being at the right place at the right time: the role of nuclear transport in dynamic transcriptional regulation in yeast.

As a consequence of compartmentalization in eukaryotic cells, the transcriptional response to extracellular stimuli requires signals to be transmitted from the cytoplasm to the nucleus. Thus, nuclear import and export of signal transduction and transcription factors provide an important level of transcriptional control in eukaryotes. Recent investigations have illustrated the importance of this control for dynamic gene expression, as will be discussed on transcriptional activators and repressors (Mac1p, Mig1p, Msn2p/4p, Swi5p) and protein kinases (Hog1p, Sty1/Spc1, protein kinase A).

Animals↗
PubMed1998

Nuclear localization of the C2H2 zinc finger protein Msn2p is regulated by stress and protein kinase A activity.

Msn2p and the partially redundant factor Msn4p are key regulators of stress-responsive gene expression in Saccharomyces cerevisiae. They are required for the transcription of a number of genes coding for proteins with stress-protective functions. Both Msn2p and Msn4p are Cys2His2 zinc finger proteins and bind to the stress response element (STRE). In vivo footprinting studies show that the occupation of STREs is enhanced in stressed cells and dependent on the presence of Msn2p and Msn4p. Both factors accumulate in the nucleus under stress conditions, such as heat shock, osmotic stress, carbon-source starvation, and in the presence of ethanol or sorbate. Stress-induced nuclear localization was found to be rapid, reversible, and independent of protein synthesis. Nuclear localization of Msn2p and Msn4p was shown to be correlated inversely to cAMP levels and protein kinase A (PKA) activity. A region with significant homologies shared between Msn2p and Msn4p is sufficient to confer stress-regulated localization to a SV40-NLS-GFP fusion protein. Serine to alanine or aspartate substitutions in a conserved PKA consensus site abolished cAMP-driven nuclear export and cytoplasmic localization in unstressed cells. We propose stress and cAMP-regulated intracellular localization of Msn2p to be a key step in STRE-dependent transcription and in the general stress response.

Amino Acid Sequence↗
PubMedDate not supplied

Determination of the beta- branching ratio of 64Cu by mass spectrometric investigations of the decay products in neutron transmuted copper.

The beta- branching ratio of 64Cu was determined by investigating the resulting decay products in copper doped by neutron transmutation. The numbers of 64Zn and 64Ni atoms were analyzed using isotope dilution analysis combined with thermal ionization mass spectrometry. A beta- branching ratio of (38.06+/-0.30)% was obtained, which agrees with the study of Kawada (Appl. Radiat. Isot. 37 (1) (1986) 7) to a higher accuracy. However, our result differs from the value cited in the NUDAT database of (39.0+/-0.3)%.

Journal Article↗