| 1. |
- Keller, H., et al.
(författare)
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Search for Forbidden Beta-Decays of the Drip-Line Nucleus Be-12
- 1994
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Ingår i: Zeitschrift fur Physik A Hadrons and Nuclei. - 1431-5831 .- 0939-7922. ; 348:1, s. 61-62
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Tidskriftsartikel (refereegranskat)abstract
- Beta-coincident gamma-rays have been measured from implanted pure samples of Be-12 separated at the LISE3 spectrometer at GANIL. An intensity of 0.040(26)% can be estimated for the branching ratio of the isospin forbidden pure-Fermi transition to the 0+ excited state of B-12 and of 0.008(6) % of the transition to the 1- excited state. Both are taken to represent upper limits. The halflife has been re-measured to be 26.1(2.4) ms.
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| 2. |
- Anne, R., et al.
(författare)
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Dissociation Reactions of the Be-11 One-Neutron Halo - the Interplay between Structure and Reaction-Mechanism
- 1993
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Ingår i: Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. - 0370-2693. ; 304:1-2, s. 55-59
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Tidskriftsartikel (refereegranskat)abstract
- The angular distributions of the forward neutrons in the exclusive (Be-10 + n) channel have been measured. They can be accounted for quantitatively and without free parameters in terms of Coulomb and diffraction dissociation. The results show that the transverse momentum distributions result from an interplay between the tail of the wave function (the halo) and the reaction mechanism.
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| 3. |
- Anne, R., et al.
(författare)
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Exclusive and Restricted-Inclusive Reactions Involving the Be-11 One-Neutron Halo
- 1994
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Ingår i: Nuclear Physics A. - : Elsevier BV. - 0375-9474. ; 575:1, s. 125-154
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Tidskriftsartikel (refereegranskat)abstract
- Reactions of a 41 MeV/u beam of the radioactive halo nucleus Be-11 have been studied with a counter telescope coupled to an array of neutron detectors covering angles up to 97-degrees. The technique allows to determine single-neutron inclusive and exclusive angular distributions. The targets (Be, Ti and Au) were chosen to illustrate the relative roles played by nuclear and Coulomb mechanisms. The channels leading to Be-10, the dissociation channels, correspond to impact parameters larger than the sum of the radii of the target and the Be-10 core. It is shown that for the dissociation process it is possible to account almost quantitatively for the integral, single- and double-differential cross sections from models without free parameters including the Coulomb, Serber and Glauber (diffraction-dissociation) mechanisms. The neutron distributions from the nondissociative reaction channels show little individuality and it is convenient to group them together as the channel ''neutron plus anything different from Be-10''. We refer to these as ''restricted-inclusive'' reactions. These seem to be a promising tool for obtaining accurate information on the halo wave function in momentum coordinates.
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| 4. |
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| 5. |
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| 6. |
- Gershenson, M. E., et al.
(författare)
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Quantum interference effects in percolated metal networks
- 1994
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Ingår i: Physica B: Condensed Matter. - : Elsevier BV. - 0921-4526. ; , s. 1109-1110
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Konferensbidrag (refereegranskat)abstract
- Quantum corrections (QC) to the resistivity due to weak localization (WL) and electron-electron interaction (EEI) have been measured for percolated metal networks with percolation coherence length z comparable to the quantum length scales-the phase-breaking length L and the thermal diffusion length LT. Far from the percolation metal-insulator transition (MIT) the `macroscopic' disorder is averaged over the quantum lengths (L,LTz) and the QC are of the universal two-dimensional (2D) type with R=R(z), where R(z) is the resistance per square at scales larger than z. A crossover 2D1D in the dimensionality of the QC and the Nyquist phase-braking mechanism is observed near the MIT, where zL,LT
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| 7. |
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| 8. |
- Landin-Olsson, Mona, et al.
(författare)
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Immunoreactive trypsin(Ogen) in the sera of children with recent-onset insulin-dependent diabetes and matched controls
- 1990
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Ingår i: Pancreas. - : Ovid Technologies (Wolters Kluwer Health). - 0885-3177. ; 5:3, s. 241-247
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the exocrine pancreatic function at the time of diagnosis of insulin-dependent diabetes mellitus, we determined immunoreactive an-odal and cathodal trypsin(ogen) levels in sera from almost all children (n = 375) 0-14 years of age in Sweden in whom diabetes developed during 1 year, and in sex-, age-, and geographically matched control subjects (n = 312). The median level of anodal trypsin(ogen) was 5 (quartile range, 3-7) µg/L in children with newly diagnosed diabetes, compared with a median level of 7 (quartile range, 4-8) µg/L in control subjects (p < 0.0001). Similarly, the median level of cathodal trypsin(ogen) was 8 (quartile range, 4-10) µg/L in children with diabetes, compared with a median level of 11 (quartile range, 7-15) µg/L in control subjects (p < 0.0001). The median of the individual ratios between cathodal and anodal trypsin(ogen) was 1.4 in the diabetic patients and 1.7 in the control children (p < 0.001). In a multivariate test, however, only the decrease in cathodal trypsin(ogen) concentration was associated with diabetes. The levels of trypsin(ogen)s did not correlate with levels of islet cell antibodies, present in 81% of the diabetic children. Several mechanisms may explain our findings, for example, similar pathogenetic factors may affect both the endocrine and exocrine pancreas simultaneously, a failing local trophic stimulation by insulin on the exocrine cells may decrease the trypsinogen production, and there may be an increased elimination of trypsin(ogen) because of higher filtration through the kidneys in the hyperglycemic state.
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| 9. |
- Montandon, A. J., et al.
(författare)
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Direct estimate of the haemophilia B (factor IX deficiency) mutation rate and of the ratio of the sex-specific mutation rates in Sweden
- 1992
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Ingår i: Human Genetics. - 0340-6717. ; 89:3, s. 319-322
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Tidskriftsartikel (refereegranskat)abstract
- Mutation rates for X-linked recessive diseases have so far been estimated indirectly by postulating an equilibrium between the loss of defective genes caused by the low reproductive fitness of affected males and the gain resulting from new mutations. Here, for the first time, we directly estimate both the overall and sex-specific mutation rates for haemophilia B by detecting the gene defect of the families registered at the Malmö Haemophilia Centre. These represent a complete sample of the Swedish haemophilia B population (45 out of 77 pedigrees) and contain 23 families with a single affected male. Fifteen of these males had mothers available for study, and of these mothers, 13 had parents available for study. We show that 3 of the above patients and 10 of their mothers carry new mutations, and by extrapolation calculate that 8 males and 98 females should carry new haemophilia B mutations in the Swedish population (8.52 × 106 individuals). This leads to the following estimate of the mutation rates: overall μ = 4.1 × 10-6; male specific v = 2.1 × 10-5; and female specific u = 1.9 × 10-6. The ratio of such male to female specific mutation rates is thus v/u = 11.
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| 10. |
- Nilsson, J, et al.
(författare)
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Competitive elution of protein A fusion proteins allows specific recovery under mild conditions.
- 1994
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Ingår i: European Journal of Biochemistry. - : Wiley. - 0014-2956 .- 1432-1033. ; 224:1, s. 103-8
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Tidskriftsartikel (refereegranskat)abstract
- A novel system is described for mild elution of fusion proteins by competitive elution. The approach is based on displacement of immobilized fusions containing a monovalent IgG-binding staphylococcal protein A fragment (Z) from an IgG-affinity matrix by a divalent fragment fused to a serum-albumin-binding region derived from streptococcal protein G. Using real-time interaction analysis, the binding (K(aff)) to polyclonal human IgG was found to be 3.3 (+/- 0.4) x 10(8) M-1 for divalent ZZ and 2.0 (+/- 0.1) x 10(7) M-1 for monovalent Z. This more than tenfold difference in binding strength ensures a high efficiency in the elution step. The competitor protein can specifically be removed and recovered from the elution mixture by subsequent passage through a human serum albumin(HSA)-affinity column, leaving only the target fusion protein in the flow-through fraction. Here, we show that a recombinant Klenow fragment of DNA polymerase I expressed in Escherichia coli can be recovered with high yield, and retained activity, from a crude bacterial lysate by IgG-affinity chromatography using mild conditions during both binding and elution.
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