[en] Motivated by attemp to explain the strong variation in energy of the excited O⁺ state in even Ge isotopes in terms of a simple collective configuration, a boson mapping is introduced for proton, neutron and proton-neutron pairing

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[en] Aim: Some organogermanium compounds, such as Ge-132 and spirogermanium, have been proved to have antitumor activity and have been used for cancer therapy. The aim of this study is searching for more effective antitumor agents from organogermanium sesquioxides and establishing basis for further elucidating their structure-effect relationship. Methods: Seven new organogermanium sesquioxides have been synthesized and characterized by elemental analysis and IR spectra. Antitumor activities against KB, HCT and Bel cells in vitro were tested. A rapid method is described for the labelling three of the compounds (compound 3,4,6) with Tc-99m and the optimum labelling conditions are investigated. The biodistribution of the three compounds labelled with Tc-99m was measured. Results: Compound 6 (gamma-thiocarbamido triethyl germanium sesquioxide) shows excellent antitumor activities, its inhibition yield to KB, HCT and Bel is 92.9%, 84.9% and 70.9%, respectively. The labelling yield is above 90% in pH 7.0 ∼ 8.0, T = 20 deg. C, t > 10 min, 1 mg of the germanium sesquioxides and 0.1 mg of stannous chloride. The biodistribution of the three compounds in normal mice shows that the compounds are mainly taken up by liver, kidney and lung. The biodistribution of compound 6 in nude mice bearing human colonic xenografts shows that the tumor uptakes are 0.734, 0.970, 0.886 and 0.615 ID%/g at 1 h, 3 h, 6 h and 20 h post injection, respectively. T/NT is 18.3 for tumor versus brain and 5.81 for tumor versus muscle at 20 h post injection. The tumor clearance is slow. Conclusion: The results show that compound 6 may be developed to be a suitable cancer therapeutic agent. The in vivo antitumor effects and the structure-effect relationship of the organogermanium sesquioxides need to be further investigated

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[en] Traditional ways of centrifugation of silicon and germanium tetrafluorides using for isotope separation and so chloride schemes of the processes are represented. Experiments conducted with germanium tetrachloride show stability of this working substance in separation equipment. To increase efficiency of silicon-28 preparation it is proposed to use trichlorosilane as working substance in centrifugal separation process

[en] Short note. 2 refs

No abstract available

[en] It was assumed that there are the only two-body interactions among the nucleons. According to this assumption we derived the equation of neutron separation energy for a given nuclei, and calculated the neutron separation energies of Ge-, Sr-, and Zr- isotopes. From the results of calculations we determined the single particle energy and the pairing energy of a given shell. (Author)

[en] It was assumed that there are the only two-body interactions among the nucleons. According to this assumption we derived the equation of neutron separation energy for a given nuclei, and calculated the neutron separation energies of Ge-, Sr-, and Zr- isotopes. From the results of calculations we determined the single particle energy and the pairing energy of a given shell. (Author)

[en] The strong variation in energy of the first excited 0⁺ state in the even-even Ge isotopes is investigated with pairing type interactions in various model spaces. Although it had been possible in previous work to describe this variation in a BCS--random-phase-approximation (RPA) calculation in the neutron configuration only, the corresponding exact diagonalization disagrees with the BCS-RPA results and experiment. It is furthermore shown that the behavior of the first excited 0⁺ state cannot be obtained by a reasonable variation of parameters in the exact neutron pair calculations. This suggests that the model space be enlarged to include proton, neutron, and proton-neutron pairing. The construction of the corresponding basis is then simplified by performing a boson mapping and employing the ideal collective boson basis. This, however, may lead to the occurrence of spurious states, even at fairly low energies, and three separate methods by means of which they can be identified are discussed. Although the enlarged model space gives a desired lowering of excitation energy of the first excited 0⁺ states in an exact diagonalization, the strong experimental variation could not be achieved with this simple interaction. Nevertheless, the analysis yields further and new insight into applications of boson mappings, specifically about how and when spurious states may be identified in calculations which are performed in a truncated space not invariant under a given collective algebra