M?ssbauer studies of hemoglobin in erythrocytes exposed to neutron radiation

We studied radiation effects on the stability of various states of hemoglobin (Hb) in red blood cells (RBC) irradiated with a very low dose of neutron rays, 50?μGy. We investigated RBCs isolated from blood of healthy donors. M?ssbauer spectroscopy was applied to monitor different forms of Hb. Our results show, for the first time, that oxyhemoglobin (OxyHb) and deoxyhemoglobin (DeoxyHb) are two Hb forms sensitive to such a low neutron radiation. Both Hbs change into a new Hb form (Hb_irr). Additionally, OxyHb transfers into HbOH/H₂O, which under our experimental conditions is resistant to the action of neutron rays.     

Supersymmetric dark matter sectors

We investigate the properties of a dark matter sector where supersymmetry is a good symmetry. In this context we find that the stability of the dark matter candidate is possible even when R-parity is broken in the visible sector. In order to illustrate the idea we investigate a simple scenario where the dark matter candidate is the lightest scalar field in the dark sector which annihilates mainly into two sfermions when these channels are available. We study the relic density constraints and the predictions for the dark matter detection experiments.     

γ Spectroscopy of 209Pb with deep inelastic reactions

High spin states in nuclei around ²⁰⁸Pb were populated in deep inelastic collisions of ⁷⁶Ge, ¹³⁶Xe, and ²⁰⁸Pb projectiles with ²⁰⁸Pb targets at beam energies about 12% above the Coulomb barrier. New states in ²⁰⁹Pb were found by measuring γ-γ-coincidences. They are interpreted as the yrast states that originate from the coupling of one neutron to the lowest excitations of the ²⁰⁸Pb core. The results are discussed in the frame of the shell model. Received: 22 November 1997     

Gamma spectroscopy of neutron-rich nuclei from the vicinity of the “island of inversion” atN=20

Neutron-richsdf shell nuclei produced by deep-inelastic processes in collision of 230 MeV³⁷Cl ions on a thick²⁰⁸Pb target have been studied via in-beam spectroscopic methods. Candidates for negative parity states in³²Si and³²Al have been identified. Yrast states with spins up to 13/2 have been located in the previously unknown³⁷P nucleus.     

Dynamical deformation of nuclei participating in deep-inelastic collisions

TheN/Z equilibration process taking place in deep-inelastic heavy ion collisions above the Coulomb barrier was studied by means of thick target gamma spectroscopy method. The analysis of gamma coincidence data obtained for four heavy ion systems gave complete distributions of primary reaction products which allowed to extract the most probableN/Z ratios as a function of mass. The comparison of experimentalN/Z values with expectations based on potential energy minimization leads to conclusion that during the crucial interaction time the involved nuclei are dynamically deformed.     

Decays of(vh_{11/2} ^n )^{10 + } and(\pi d_{5/2} vh_{11/2} ^n )^{25/2 + } isomers in even-A Sn and odd-A Sb nuclei

Isomeric decays in^{116, 118, 120}Sn and^{119, 120}Sb have been studied by measurements of delayedγ-rays following reactions of 26–40 MeV⁷Li ions on Cd targets. A 6.3 μs isomer of \((vh_{11/2} ^n )^{10 + } \) character in¹²⁰Sn is reported. The experimental variation inB(E2, 10⁺ → 8⁺) between \(vh_{11/2} ^n \) states in^{116, 118, 120, 128, 130}Sn is compared with the expected dependence on vh^11/2 subshell occupation number. Isomerism in Sb nuclei is also discussed, and a known high-spin isomer in¹¹⁹Sb is assigned the same seniority-three configuration \((\pi d_{5/2} vh_{11/2} ^n )^{25/2 + } \) as a well-established 340 μs isomer in¹¹⁷Sb.     

Structure and thermodynamic melting parameters of wheat starches with different amylose content

The hierarchical granule structure of starches with different amylose content extracted from winter wheat was investigated using light microscopy (LM), scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXS), high-sensitivity differential scanning calorimetry (HS DSC) and different thermodynamic approaches. Morphology (size, size distribution and shape), crystallinity of native granules with different amylose content (1.5-39.5%), as well as the cooperative melting unit, thickness of crystalline lamellae, heat capacity drop related to hydration during melting of native granules, and thermodynamic parameters related to the surface of crystalline lamellae were determined. The relationship between structure and thermodynamic properties of mutant wheat starches is discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Mobility of inorganic nanoparticles in soft matter

The 100 nm hematite Fe₂O₃ particles in gelatin gel, dense water solution of sugar, commercial paints, foam, cosmetic cream and friable powder exhibit the mobility in the range of mm/s which was determined from the analysis of the resonance absorption line shape. In the solution of sugar the movement is correlated for particle–particle distance less then 300 nm. The Mössbauer spectroscopy of the iron bearing nanoparticles is proposed as a novel experimental technique for the investigation of the dynamical and structural properties of the soft matter at the mesoscoipic scale.     

Magic nucleus 132Sn and its one-neutron-hole neighbor 131Sn

Prompt and delayed gamma-ray cascades in doubly magic 132Sn and its neighbor 131Sn have been studied at Gammasphere using a 248Cm fission source. Isotopic assignments of unknown gamma rays were based on coincidences with known transitions in A = 112-116 Pd fission partners. The yrast level spectra of both tin nuclei are interpreted using empirical nucleon-nucleon interactions from the 132Sn and 208Pb regions. Results include identification of the (nuf(7/2)h(-1)(11/2))9(+) aligned state in 132Sn and of extensive (nuf(7/2)h(-2)(11/2)), (nuf(7/2)d(-1)(3/2)h(-1)(11/2)) and (nuh(-1)(11/2)x3(-)) multiplets in 131Sn. The previously reported beta(-) decay of an unusual 131In high-spin isomer to levels in 131Sn is also elucidated.