Iron speciation in human cancer cells by K-edge total reflection X-ray fluorescence–X-ray absorption near edge structure analysis

X-ray absorption near edge structure (XANES) analysis in combination with synchrotron radiation induced total reflection X-ray fluorescence (SR-TXRF) acquisition was used to determine the oxidation state of Fe in human cancer cells and simultaneously their elemental composition by applying a simple sample preparation procedure consisting of pipetting the cell suspension onto the quartz reflectors.XANES spectra of several inorganic and organic iron compounds were recorded and compared to that of different cell lines. The XANES spectra of cells, independently from the phase of cell growth and cell type were very similar to that of ferritin, the main Fe store within the cell. The spectra obtained after CoCl₂ or NiCl₂ treatment, which could mimic a hypoxic state of cells, did not differ noticeably from that of the ferritin standard. After 5-fluorouracil administration, which could also induce an oxidative-stress in cells, the absorption edge position was shifted toward higher energies representing a higher oxidation state of Fe. Intense treatment with antimycin A, which inhibits electron transfer in the respiratory chain, resulted in minor changes in the spectrum, resembling rather the N-donor Fe-α,α′-dipyridyl complex at the oxidation energy of Fe(III), than ferritin. The incorporation of Co and Ni in the cells was followed by SR-TXRF measurements.     

Erklärung der unregelmäßigen Kataphorese der Eiweiß-Methylenblauadsorbate mit Hilfe der Hydronentheorie

Colloid and Polymer Science -     

Die Adsorption von Hefephosphorprotein durch verschiedene Adsorbentien und die Elution der Adsorbate

Ohne Zusammenfassung     

An Efficient Method for using Molecular Symmetry. In Advance Selection of Zero Integrals

The molecular symmetry has previously been used in an effective way for the reduction of the number of two-electron integrals to be calculated. Here the method is further developed in such a way that the zero integrals due to the molecular symmetry can be easily selected in advance. It is pointed out, that this method, without using indices for the integrals does not need extra computational effort. The gain in computer time has been shown in the case of normal saturated hydrocarbons.     

Isolation of Some Antimicrobial Compounds of Red Wine by OPLC Flowing Eluent Wall Technique

The first results of the combination of BioArena and OPLC with flowing eluent wall technique (FEW) show an especially attractive solution of the detection of antimicrobial activity and compound isolation based on peak collection. Because of the different separation mechanisms applied for on-line FEW–OPLC isolation of red wine constituents and for further off-line OPLC investigation of fractions, the combined system yields high selectivity.     

Ueber die Natur des peptidspaltenden Fermentes in Erbsenmazeraten

Ohne Zusammenfassung