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G de Angelis

Publications and source records attributed to G de Angelis.

12 recordsLinked to original sources
PubMed2006

Observation of 54Ni: cross-conjugate symmetry in f7/2 mirror energy differences.

Gamma decays from excited states up to Jpi=6+ in the N=Z-2 nucleus 54Ni have been identified for the first time. Level energies are compared with those of the isobars 54Co and 54Fe and of the cross-conjugate nuclei of mass A=42. The good but puzzling f7/ cross-conjugate symmetry in mirror and triplet energy differences is analyzed. Shell model calculations reproduce the new data but the necessary nuclear charge-dependent phenomenology is not fully explained by modern nucleon-nucleon potentials.

Journal Article↗
PubMed2006

Transition probabilities in 134Pr: a test for chirality in nuclear systems.

Exited states in 134Pr were populated in the fusion-evaporation reaction 119Sn(19F,4n)134Pr. Recoil distance Doppler-shift and Doppler-shift attenuation measurements using the Euroball spectrometer, in conjunction with the inner Bismuth Germanate ball and the Cologne plunger, were performed at beam energies of 87 MeV and 83 MeV, respectively. Reduced transition probabilities in 134Pr are compared to the predictions of the two quasiparticle + triaxial rotor and interacting boson fermion-fermion models. The experimental results do not support the presence of static chirality in 134Pr underlying the importance of shape fluctuations. Only within a dynamical context the presence of intrinsic chirality in 134Pr can be supported.

Journal Article↗
PubMed2005

Evidence for nontermination of rotational bands in 74Kr.

Three rotational bands in 74Kr were studied up to (in one case one transition short of) the maximum spin I(max) of their respective single-particle configurations. Their lifetimes have been determined using the Doppler-shift attenuation method. The deduced transition quadrupole moments reveal a modest decrease, but far from a complete loss of collectivity at the maximum spin I(max). This feature, together with the results of mean field calculations, indicates that the observed bands do not terminate at I = I(max).

Journal Article↗
PubMed2004

Effective charges in the fp shell.

Following the heavy-ion fusion-evaporation reaction 32S+24Mg at 95 MeV beam energy the lifetimes of analogue states in the T(z)=+/-1/2 A=51 mirror nuclei 51Fe and 51Mn have been measured using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The deduced B(E2;27/2(-)-->23/2(-)) values afford a unique opportunity to probe isoscalar and isovector polarization charges and to derive effective proton and neutron charges, epsilon(p) and epsilon(n), in the fp shell. A comparison between the experimental results and several different large-scale shell-model calculations yields epsilon(p) approximately 1.15e and epsilon(n) approximately 0.80e.

Journal Article↗
PubMed2004

Unusual isospin-breaking and isospin-mixing effects in the A=35 mirror nuclei.

Excited states have been studied in 35Ar following the 16O(24Mg,1alpha1n)35Ar fusion-evaporation reaction at 60 MeV using the Ge-detector array GASP. A comparison with the mirror nucleus 35Cl shows two remarkable features: (i) A surprisingly large energy difference for the 13/2(-) states, in which the hitherto overlooked electromagnetic spin-orbit term is shown to play a major role, and (ii) a very different decay pattern for the 7/2(-) states, which provides direct evidence of isospin mixing.

Journal Article↗
PubMed2001

Coulomb energy differences in t = 1 mirror rotational bands in (50)Fe and (50)Cr.

Gamma rays from the N = Z-2 nucleus (50)Fe have been observed, establishing the rotational ground state band up to the state J(pi) = 11+ at 6.994 MeV excitation energy. The experimental Coulomb energy differences, obtained by comparison with the isobaric analog states in its mirror (50)Cr, confirm the qualitative interpretation of the backbending patterns in terms of successive alignments of proton and neutron pairs. A quantitative agreement with experiment has been achieved by exact shell model calculations, incorporating the differences in radii along the yrast bands, and properly renormalizing the Coulomb matrix elements in the pf model space.

Journal Article↗
PubMed2001

Predictive laboratory diagnostics in oncology utilizing blood-borne cancer cells--current best practice and unmet needs.

The aim of laboratory diagnostics in oncology is to improve the clinical outcome of cancer by allowing earlier detection. Molecular knowledge of cancer should increase the number of risk and prognostic factors and will allow development of methods for detection and elimination of even very small tumors. Thus, the race for the specific tumor antigen in peripheral blood and the race for the blood-borne cancer cell happened simultaneously. The direct detection of the cells which have the highest probability to harbor all the properties mandatory to be life-threatening, conceivably metastatic, would be the most promising way to find the target structure of malignancy. Methods applying enrichment techniques based on density, morphology, tissue specific protein and tumor-associated protein detection enabled multi-parametric analysis of those blood-borne cancer cells. In exemplary studies it was demonstrated that the count of cell clusters positive for the tissue-specific proteins cytokeratin and prostate-specific antigen (PSA) from the peripheral blood of prostate cancer patients and a combination of a tissue-specific protein, a oncogenic receptor protein cytokeratin and p185(c-erbB-2) from the peripheral blood of breast cancer patients is related to the stage of the diseases. Breast cancer patients who presented with cytokeratin/p185(c-erbB-2) positive cell clusters showed a decrease of those cells under adriamycin adjuvant therapy. Nevertheless, additional molecular markers are required to characterize the functional properties of blood-borne cancer cells. Therefore, the genome of the cells can be investigated using a procedure for indirectly detecting aberrations of defined gene locations, i.e. multiplex microsatellite polymerase chain reaction. Up to now, the methods applied to the separation of blood-borne cancer cells are time-consuming and rather expensive. They consist of an initial enrichment step of density gradient centrifugation or buffy coat preparation followed by a specific isolation step using superparamagnetic microbeads coupled to antibodies, filter techniques or multi-parametric flow cytometry. Novel technologies have to be applied using miniaturization, integration and parallel-processing techniques based on those used in the computer industry to overcome the drawbacks.

Antigens, Neoplasm↗
PubMed2001

Duodenal IgE-positive cells and elimination diet responsiveness in children with atopic dermatitis.

BACKGROUND: Parameters for identifying eczematous children who could respond to an elimination diet are needed. In children with food allergy, duodenal IgE-containing cells are enhanced. OBJECTIVE: To determine the presence of duodenal mucosal IgE-positive cells in atopic dermatitis and to determine whether duodenal IgE-positive cells may identify eczematous children who will benefit from an elimination diet. METHODS: Thirty-one children with severe eczema underwent gastrointestinal endoscopy because of gastrointestinal symptoms and were treated with an elimination diet. A clinical score to skin lesions was given before and after diet. All subjects were skin-prick tested with food antigens and aeroallergens. Serum IgE levels were measured. Duodenal IgE-positive cells were investigated in 18 control subjects and in all eczematous children before diet. RESULTS: The number of duodenal IgE-positive cells in children with atopic dermatitis was significantly increased compared with that of control group (P < 0.001). Nineteen (61%) eczematous children improved on a few food diet. Diet-responsive children had significantly higher IgE-positive cells compared with both nondiet-responsive and controls. Positive predictive accuracy of duodenal IgE-positive cells was poor, whereas negative predictive accuracy was high at the cutoff level of 50 IgE-positive cells/10 visual fields. Diagnostic accuracy both of SPT reactions with foods and of food-specific serum IgE antibodies was poor. CONCLUSIONS: An intestinal IgE-mediated reaction occurred in children with severe atopic dermatitis who underwent intestinal endoscopy because of gastrointestinal symptoms. In these eczematous children, the number of IgE-positive cells in the duodenal mucosa might be helpful for excluding a positive response to the elimination diet.

Adolescent↗
PubMed1985

[Guillain-Barre syndrome in pregnancy].

Three cases of Landry-Guillain-Barré syndrome in association with pregnancy are reported. In two, the polyradiculoneuritis occurred once. The third patient presented relapsing episodes during pregnancy and when taking oral contraceptives. The evolution of the disease in relation with pregnancy, labour and the possible effects on the foetus are examined. The relapsing polyradiculoneuritis provides a most appropriate case to investigate the relationship between hormonal and humoral modifications of pregnancy and the pathophysiology and etiology of polyradiculoneuritis.

Adult↗