1,089 research outputs found
Fitting Skyrme functionals using linear response theory
Recently, it has been recently shown that the linear response theory in
symmetric nuclear matter can be used as a tool to detect finite size
instabilities for different Skyrme functionals. In particular it has been shown
that there is a correlation between the density at which instabilities occur in
infinite matter and the instabilities in finite nuclei. In this article we
present a new fitting protocol that uses this correlation to add new additional
constraint in Symmetric Infinite Nuclear Matter in order to ensure the
stability of finite nuclei against matter fluctuation in all spin and isospin
channels. As an application, we give the parameters set for a new Skyrme
functional which includes central and spin-orbit parts and which is free from
instabilities by construction.Comment: Proceeding of 19th Nuclear Physics Workshop "Marie & Pierre Curie"
Kazimierz 201
Generalized seniority for the shell model with realistic interactions
The generalized seniority scheme has long been proposed as a means of
dramatically reducing the dimensionality of nuclear shell model calculations,
when strong pairing correlations are present. However, systematic benchmark
calculations, comparing results obtained in a model space truncated according
to generalized seniority with those obtained in the full shell model space, are
required to assess the viability of this scheme. Here, a detailed comparison is
carried out, for semimagic nuclei taken in a full major shell and with
realistic interactions. The even-mass and odd-mass Ca isotopes are treated in
the generalized seniority scheme, for generalized seniority v<=3. Results for
level energies, orbital occupations, and electromagnetic observables are
compared with those obtained in the full shell model space.Comment: 13 pages, 8 figures; published in Phys. Rev.
The tensor part of the Skyrme energy density functional. III. Time-odd terms at high spin
This article extends previous studies on the effect of tensor terms in the
Skyrme energy density functional by breaking of time-reversal invariance. We
have systematically probed the impact of tensor terms on properties of
superdeformed rotational bands calculated within the cranked
Hartree-Fock-Bogoliubov approach for different parameterizations covering a
wide range of values for the isoscalar and isovector tensor coupling constants.
We analyze in detail the contribution of the tensor terms to the energies and
dynamical moments of inertia and study their impact on quasi-particle spectra.
Special attention is devoted to the time-odd tensor terms, the effect of
variations of their coupling constants and finite-size instabilities.Comment: 28 pages, 34 figure
Quadrupole collective variables in the natural Cartan-Weyl basis
The matrix elements of the quadrupole collective variables, emerging from
collective nuclear models, are calculated in the natural Cartan-Weyl basis of
O(5) which is a subgroup of a covering structure. Making
use of an intermediate set method, explicit expressions of the matrix elements
are obtained in a pure algebraic way, fixing the -rotational structure
of collective quadrupole models.Comment: submitted to Journal of Physics
The role of HLA-DP mismatches and donor specific HLA-DP antibodies in kidney transplantation : a case series
BACKGROUND:
The impact of HLA-DP mismatches on renal allograft outcome is still poorly understood and is suggested to be less than that of the other HLA loci. The common association of HLA-DP donor-specific antibodies (DSA) with other DSA obviates the evaluation of the actual effect of HLA-DP DSA.
METHODS:
From a large multicenter data collection, we retrospectively evaluated the significance of HLA-DP DSA on transplant outcome and the immunogenicity of HLA-DP eplet mismatches with respect to the induction of HLA-DP DSA. Furthermore, we evaluated the association between the MFI of HLA-DP antibodies detected in Luminex assays and the outcome of flowcytometric/complement-dependent cytotoxicity (CDC) crossmatches.
RESULTS:
In patients with isolated pretransplant HLA-DP antibodies (N = 13), 6 experienced antibody-mediated rejection (AMR) and 3 patients lost their graft. In HLAMatchmaker analysis of HLA-DP mismatches (N = 72), HLA-DP DSA developed after cessation of immunosuppression in all cases with 84DEAV (N = 14), in 86% of cases with 85GPM (N = 6/7), in 50% of cases with 56E (N = 6/12) and in 40% of cases with 56A mismatch (N = 2/5). Correlation analysis between isolated HLA-DP DSA MFI and crossmatches (N = 90) showed negative crossmatch results with HLA-DP DSA MFI <2000 (N = 14). Below an MFI of 10,000 CDC crossmatches were also negative (N = 33). Above these MFI values both positive (N = 35) and negative (N = 16) crossmatch results were generated.
CONCLUSIONS:
Isolated HLA-DP DSA are rare, yet constitute a significant risk for AMR. We identified high-risk eplet mismatches that can lead to HLA-DP DSA formation. We therefore recommend HLA-DP typing to perform HLA-DP DSA analysis before transplantation. HLA-DP DSA with high MFI were not always correlated with positive crossmatch results
Probing pairing correlations in Sn isotopes using Richardson-Gaudin integrability
Pairing correlations in the even-even A=102-130 Sn isotopes are discussed,
based on the Richardson-Gaudin variables in an exact Woods-Saxon plus reduced
BCS pairing framework. The integrability of the model sheds light on the
pairing correlations, in particular on the previously reported sub-shell
structure.Comment: Proceedings of the XX International School on Nuclear Physics,
Neutron Physics and Applications, Varna, Bulgaria, 16-22 September, 201
Configuration mixing in Pb : band structure and electromagnetic properties
In the present paper, we carry out a detailed analysis of the presence and
mixing of various families of collective bands in Pb. Making use of the
interacting boson model, we construct a particular intermediate basis that can
be associated with the unperturbed bands used in more phenomenological studies.
We use the E2 decay to construct a set of collective bands and discuss in
detail the B(E2)-values. We also perform an analysis of these theoretical
results (Q, B(E2)) to deduce an intrinsic quadrupole moment and the associated
quadrupole deformation parameter, using an axially deformed rotor model.Comment: submitted to pr
Spectral properties of a tractable collective Hamiltonian
The spectral properties of a tractable collective model Hamiltonian are
studied. The potential energy is truncated up to quartic terms in the
quadrupole deformation variables, incorporating vibrational,
-independent rotational and axially deformed rotational structures.
These physically significant limits are analysed in detail and confronted with
well-established approximation schemes. Furthermore, transitional Hamiltonians
in between the limits are presented and discussed. All results are obtained
within a recently presented Cartan-Weyl based framework to calculate
embedded quadrupole collective observables.Comment: submitted to PR
Prognostic value of bcl-2 expression in invasive breast cancer.
Expression of the bcl-2 proto-oncogene was studied immunohistochemically in 251 invasive ductal breast carcinomas (median follow-up time 91 months, range 24-186 months) and the results were correlated with clinicopathological data and prognostic variables. Sixty-three (25%) tumours were scored bcl-2 negative and 188 (75%) tumours were bcl-2 positive. No relationship could be observed between bcl-2 status and tumour grade, pTNM staging or menopausal status. A strong positive relationship was demonstrated between bcl-2 immunoreactivity and oestrogen receptor status (P < 0.001) and progesterone receptor status (P < 0.001). No prognostic value was demonstrated for bcl-2 expression on disease-free survival and overall survival in axillary node-negative breast cancer patients. However, in axillary node-positive breast cancer patients multivariate analysis demonstrated absence of bcl-2 expression to be independently related to shortened disease-free survival (P = 0.003) and shortened overall survival (P < 0.001). Our results suggest a potential important role for bcl-2 expression as a modulator of response to adjuvant therapy in breast cancer
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