316 research outputs found
Spherical Hartree-Fock calculations with linear momentum projection before the variation.Part II: Spectral functions and spectroscopic factors
The hole--spectral functions and from these the spectroscopic factors have
been calculated in an Galilei--invariant way for the ground state wave
functions resulting from spherical Hartree--Fock calculations with projection
onto zero total linear momentum before the variation for the nuclei 4He, 12C,
16O, 28Si, 32S and 40Ca. The results are compared to those of the conventional
approach which uses the ground states resulting from usual spherical
Hartree--Fock calculations subtracting the kinetic energy of the center of mass
motion before the variation and to the results obtained analytically with
oscillator occupations.Comment: 16 pages, 22 postscript figure
Nuclear symmetry energy effects on neutron stars properties
We construct a class of nuclear equations of state based on a schematic
potential model, that originates from the work of Prakash et. al.
\cite{Prakash-88}, which reproduce the results of most microscopic
calculations. The equations of state are used as input for solving the
Tolman-Oppenheimer-Volkov equations for corresponding neutron stars. The
potential part contribution of the symmetry energy to the total energy is
parameterized in a generalized form both for low and high values of the baryon
density. Special attention is devoted to the construction of the symmetry
energy in order to reproduce the results of most microscopic calculations of
dense nuclear matter. The obtained nuclear equations of state are applied for
the systematic study of the global properties of a neutron star (masses, radii
and composition). The calculated masses and radii of the neutron stars are
plotted as a function of the potential part parameters of the symmetry energy.
A linear relation between these parameters, the radius and the maximum mass of
the neutron star is obtained. In addition, a linear relation between the radius
and the derivative of the symmetry energy near the saturation density is found.
We also address on the problem of the existence of correlation between the
pressure near the saturation density and the radius.Comment: 17 pages, 25 figure
Синтез и антиинфекционное протективное действие β-циклогексилметил- и β-2-циклогексилэтилгликозидов мурамоилдипептида
Осуществлен синтез β-циклогексилметил- и β-2-циклогексилэтилгликозидов мурамоилдипептида. Исходные перацетилированные β-циклогексилалкилглюкозаминиды были получены оксазолиновым методом. Установлено, что β-циклогексилметил- и β-(2-циклогексилэтил)-МДП обладают высоким антиинфекционным протективным эффектом при поражении мышей летальной дозой Staphylococcus aureus.Здійснено синтез β-циклогексилметил- і β-2-циклогексилетил глікозиді в мурамоїлдипептиду. Вихідні перацетильовані (β-циклогексилалкілглюкозамініди були отримані за оксазоліновим методом. Встановлено, що β-циклогексилметил- і β-(2-циклогексилетил)-МДП володіють високим антиінфекційним протективним ефектом при поразці мишей летальною дозою Staphylococcus aureus.The synthesis of β-cyclohexylmethyl- and β-2-cyclohexylethylglycosides of muramyldipeptide has been carried out. The starting peracetates of β-cyclohexylalkylglucosaminides have been obtained by the oxazoline method. It been found that β-cyclohexylmethyl- and β-(2-cyclohexylethyl)-MDP have a high anti-infection protective effect against the lethal dose of Staphylococcus aureus in mice
The effects of multidisciplinary rehabilitation: RePCa-a randomised study among primary prostate cancer patients
BACKGROUND: The objective of this study is the effectiveness of multidisciplinary rehabilitation on treatment-related adverse effects after completed radiotherapy in patients with prostate cancer (PCa). METHODS: In a single-centre oncology unit in Odense, Denmark, 161 PCa patients treated with radiotherapy and androgen deprivation therapy were randomly assigned to either a programme of two nursing counselling sessions and two instructive sessions with a physical therapist (n=79) or to usual care (n=82). Primary outcome was Expanded Prostate Cancer Index Composite (EPIC-26) urinary irritative sum-score. Before radiotherapy, pre-intervention 4 weeks after radiotherapy, and after a 20-week intervention, measurements included self-reported disease-specific quality of life (QoL; EPIC-26, including urinary, bowel, sexual, and hormonal symptoms), general QoL (Short-form-12, SF-12), pelvic floor muscle strength (Modified Oxford Scale), and pelvic floor electromyography. Intension-to-treat analyses were made with adjusted linear regression. RESULTS: The intervention improved, as compared with controls, urinary irritative sum-score 5.8 point (Cohen's d=0.40; P=0.011), urinary sum-score (d=0.34; P=0.023), hormonal sum-score (d=0.19; P=0.018), and the SF-12 Physical Component Summary, d=0.35; P=0.002. Patients with more severe impairment gained most. Pelvic floor muscle strength measured by electromyography declined in both groups, P=0.0001. CONCLUSION: Multidisciplinary rehabilitation in irradiated PCa patients improved urinary and hormonal symptoms, and SF-12 physical QoL
Threshold Effects in Multi-channel Coupling and Spectroscopic Factors in Exotic Nuclei
In the threshold region, the cross section and the associated overlap
integral obey the Wigner threshold law that results in the Wigner-cusp
phenomenon. Due to flux conservation, a cusp anomaly in one channel manifests
itself in other open channels, even if their respective thresholds appear at a
different energy. The shape of a threshold cusp depends on the orbital angular
momentum of a scattered particle; hence, studies of Wigner anomalies in weakly
bound nuclei with several low-lying thresholds can provide valuable
spectroscopic information. In this work, we investigate the threshold behavior
of spectroscopic factors in neutron-rich drip-line nuclei using the Gamow Shell
Model, which takes into account many-body correlations and the continuum
effects. The presence of threshold anomalies is demonstrated and the
implications for spectroscopic factors are discussed.Comment: Accepted in Physical Review C Figure correcte
Two-neutron separation energies, binding energies and phase transitions in the interacting boson model
In the framework of the interacting boson model the three transitional
regions (rotational-vibrational, rotational--unstable and,
vibrational--unstable transitions) are reanalyzed. A new kind of plot
is presented for studying phase transitions in finite systems such as atomic
nuclei. The importance of analyzing binding energies and not only energy
spectra and electromagnetic transitions, describing transitional regions is
emphasized. We finally discuss a number of realistic examples.Comment: 34 pages, TeX (ReVTeX). 12 ps figures. 3 tables. Submitted to Nucl.
Phys.
Hyperon-nucleon scattering and hyperon masses in the nuclear medium
We analyze low-energy hyperon-nucleon scattering using an effective field
theory in next-to-leading order. By fitting experimental cross sections for
laboratory hyperon momenta below 200 MeV/c and using information from the
hypertriton we determine twelve contact-interaction coefficients. Based on
these we discuss the low-density expansion of hyperon mass shifts in the
nuclear medium.Comment: 10 pages, 2 figure
SU(3) realization of the rigid asymmetric rotor within the IBM
It is shown that the spectrum of the asymmetric rotor can be realized quantum
mechanically in terms of a system of interacting bosons. This is achieved in
the SU(3) limit of the interacting boson model by considering higher-order
interactions between the bosons. The spectrum corresponds to that of a rigid
asymmetric rotor in the limit of infinite boson number.Comment: 9 pages, 2 figures, LaTeX, epsfi
Relativistic Contributions to Deuteron Photodisintegration in the Bethe-Salpeter Formalism
In plane wave one-body approximation the reaction of deuteron
photodisintegration is considered in the framework of the Bethe-Salpeter
formalism for two-nucleon system. Results are obtained for deuteron vertex
function, which is the solution of the homogeneous Bethe-Salpeter equation with
a multi-rank separable interaction kernel, with a given analytical form. A
comparison is presented with predictions of non-relativistic, quasipotential
approaches and the equal time approximation. It is shown that important
contributions come from the boost in the arguments of the initial state vertex
function and the boost on the relative energy in the one-particle propagator
due to recoil.Comment: 29 pages, 6 figure
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