Gamma spectra were measured and activities of the detected isotopes were analyzed for 206 high-activity particles (hot particles, HPs) found in northeastern Poland after the Chernobyl accident. The isotopic composition of HPs observed in gamma-activity is compared with that of the general fallout and core inventory calculations. Particle formation and a process of depletion in Ru and Cs isotopes are discussed. On the basis of a search performed a year later, some comments on the behavior of HPs in the soil are made.

Calf skin collagen and three amino acids essential for its structure, namely glycine, L-proline and 4-hydroxyl-L-proline, were irradiated with gamma rays up to a dose of 10 kGy. Conversion of radicals over time or after thermal annealing to selected temperatures was monitored by X-band electron paramagnetic resonance (EPR) spectroscopy. Some experimental spectra were compared with signals simulated based on literature data from the electron nuclear double resonance (ENDOR) studies. The following phenomena were confirmed in the tested amino acids: abstraction of hydrogen atom (glycine, proline, hydroxyproline, collagen), deamination (glycine, hydroxyproline), decarboxylation (hydroxyproline). Chain scission at glycine residues, radiation-induced decomposition of side groups and oxidative degradation were observed in irradiated collagen. The decay of radicals in collagen saturated with water occurred at lower temperatures than in macromolecules having only structural water. The paramagnetic centres were the most stable in an oxygen-free atmosphere (vacuum). Radical processes deteriorated the structure of collagen; hence, radiation sterilization of skin grafts requires careful pros and cons analysis.

Veresterung des Lysinderivates (II) mit dem Aminoethanol (Ia)‐Derivat (Ib) gibt den Ester (IIIa) [nachfolgende Schutzgruppenabspaltung ‐ (IIIb), nachfolgende Acylierung ‐ (IIIc)]; (IIIb) wird weiter in die Dipeptidderivate (Va), (Vb) bzw. (Vc) übergeführt; aus (Vb) sind in analoger Reaktionsfolge die Tripeptidderivate (VIa), (VIb) bzw. (VIc) erhältlich.

Ausgehend von Phenylalaninamid oder Phenylalaninmethylester wird das Tetrapeptidamid (I) synthetisiert.

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