Structure of neutron-rich Be and C isotopes

The structure of neutron-rich beryllium isotopes has been investigated using different heavy-ion-induced transfer reactions. In neutron transfer reactions, the population of final states shows a strong sensitivity to the chosen core nucleus, i.e., the target nuclei ⁹Be or ¹⁰Be, respectively. Molecular rotational bands up to high excitation energies are observed with ⁹Be as the core due to its pronounced 2α-cluster structure, whereas only a few states at low excitation energies are populated with ¹⁰Be as the core. For ¹¹Be, a detailed investigation has been performed for the three states at 3.41, 3.89, and 3.96 MeV, which resulted in the most probable spin-parity assignments 3/2⁺, 5/2^?, and 3/2^?, respectively. Furthermore, we have studied particle-hole states of ¹⁶C using the ¹³C(¹²C, ⁹C)¹⁶C reaction and found 14 previously unknown states. Using the ¹²C(¹²C, ⁹C)¹⁵C reaction, five new states were observed for ¹⁵C.     

Measurement of biological parameters during fermentation processes

Efficient fermentation control requires the measurement of biological parameters. Three techniques were tested for monitoring. In the first, the NADH-fluorescence of micro-organisms was measured in batch and in continuous cultures under aerobic and anaerobic conditions, providing information on the metabolic status of the cells. The effects of cell concentration and of different substrates (glucose, ethanol and oxygen) were studied. The second technique is the calorimetric determination of various substrates, such as penicillin or enzymes, by an enzyme/thermistor device. With immobilized penicillin acylase (E.C. 3.5.1.11) or penicillinase (E.C. 3.5.2.6), penicillin was determined selectively in a fermentation broth. The thermistor was also used to measure penicillin acylase activity. The third technique is laser flow cytometry. A commercial double-beam flow cytometry system was used to determine cell size, light scattering and the protein, DNA and RNA contents of single cells. Flow cytometry allows rapid and sensitive control of fermentation processes with genetically modified E. coli 5K (pHM12) cells. The results of monitoring the cell size, light scattering, and protein and DNA contents of different micro-organisms during fermentation are outlined.     

Synthesis and metal ion complexing properties of novel chromogenic cryptands

Four novel chromogenic benzocryptands and one side-armed chromogenic cryptand have been synthesized and their complexing abilities for alkali metal cations are described.