909 research outputs found
49Cr: Towards full spectroscopy up to 4 MeV
The nucleus 49Cr has been studied analysing gamma-gamma coincidences in the
reaction 46Ti(alpha,n)49Cr at the bombarding energy of 12 MeV. The level scheme
has been greatly extended at low excitation energy and several new lifetimes
have been determined by means of the Doppler Shift Attenuation Method.
Shell model calculations in the full pf configuration space reproduce well
negative-parity levels. Satisfactory agreement is obtained for positive parity
levels by extending the configuration space to include a nucleon-hole either in
the 1d3/2 or in the 2s1/2 orbitals.
A nearly one-to-one correspondence is found between experimental and
theoretical levels up to an excitation energy of 4 MeV.
Experimental data and shell model calculations are interpreted in terms of
the Nilsson diagram and the particle-rotor model, showing the strongly coupled
nature of the bands in this prolate nucleus. Nine values of K(pi) are proposed
for the levels observed in this experiment.
As a by-result it is shown that the values of the experimental magnetic
moments in 1f7/2 nuclei are well reproduced without quenching the nucleon
g-factors.Comment: 13 pages, 8 figure
On the Backbending Mechanism of Cr
The mechanism of backbending in Cr is investigated in terms of the
Projected Shell Model and the Generator Coordinate Method. It is shown that
both methods are reasonable shell model truncation schemes. These two quite
different quantum mechanical approaches lead to a similar conclusion that the
backbending is due to a band crossing involving an excited band which is built
on simultaneously broken neutron and proton pairs in the ``intruder'' subshell
. It is pointed out that this type of band crossing is usually known
to cause the second backbending in rare-earth nuclei.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let
Solitary fibrous tumor of the pleura: surgery and clinical course in 18 cases
Solitary fibrous tumors of the pleura are very rare neoplasms that can sometimes present with malignant features. Between 1984 and 2007, 18 cases were treated in our institution. There were 7 men and 11 women, with a median age of 56 years (range, 33-77 years). All patients underwent surgical treatment. Except for one case with hemangiopericytic features, all tumors were histologically the fibrous type of pleural mesothelioma. Resections were radical and there were no recurrences. There was no perioperative mortality. The outcome was excellent, and all patients have been followed up continuously. Survival rates at 3, 5, and 10 years were calculated as 86.7%, 75%, and 66.7%. One patient died after 18 months (malignant type of solitary fibrous tumor), and 2 died of unrelated disease after 24 and 53 months. Surgery is the treatment of choice, and careful long-term clinical follow-up is required
Typical and atypical pulmonary carcinoids: our institutional experience
Pulmonary carcinoids are rare malignant neoplasms, accounting for 2-5% of all lung tumors, with an approximate annual incidence of 2.3-2.8 cases per million of the population. We relate our experience of 54 patients (21 male, 33 female, mean age 53+/-15 years) treated between July 1986 and April 2006. All the patients underwent preoperative fibrobronchoscopy: preoperative diagnosis was made in 28 patients (52%). Surgical treatment consisted of: 31 standard lobectomies, 6 pneumonectomies, 5 bilobectomies, 2 sleeve lobectomies, 2 anatomic segmentectomies, 6 wedge resections; two patients were managed with sleeve bronchial procedure of the left main bronchus without lung resection. Fifty-four patients were followed with a mean time of observation of 67 months: 6 (11%) deaths occurred, at a mean period of 49 months after surgery; there were no postoperative deaths. Overall, 5-year survival was 91%, 10 years 83%: 5-year survival was 91% for typical carcoinoids (TC) vs. 88% for atypical (AC), 10 years 91% for TC and 44% for AC (significant value, P=0.0487). Carcinoid tumors are a distinct group of neuroendocrine tumors with a good prognosis in most cases. Surgery currently represents the best treatment with good results at mid- and long-term survival, according to an acceptable risk
On the discrete spectrum of spin-orbit Hamiltonians with singular interactions
We give a variational proof of the existence of infinitely many bound states
below the continuous spectrum for spin-orbit Hamiltonians (including the Rashba
and Dresselhaus cases) perturbed by measure potentials thus extending the
results of J.Bruening, V.Geyler, K.Pankrashkin: J. Phys. A 40 (2007)
F113--F117.Comment: 10 pages; to appear in Russian Journal of Mathematical Physics
(memorial volume in honor of Vladimir Geyler). Results improved in this
versio
Transition rates and nuclear structure changes in mirror nuclei 47Cr and 47V
Lifetime measurements in the mirror nuclei 47Cr and 47V were performed by
means of the Doppler-shift attenuation method using the multidetector array
EUROBALL, in conjunction with the ancillary detectors ISIS and the Neutron
Wall. The determined transition strengths in the yrast cascades are well
described by full pf shell model calculations.Comment: Latex2e, 11 pages, 3 figure
A homeostatic function of CXCR2 signalling in articular cartilage
Funding This work was funded by Arthritis Research UK (grants 17859, 17971, 19654), INNOCHEM EU FP6 (grant LSHB-CT-2005-51867), MRC (MR/K013076/1) and the William Harvey Research FoundationPeer reviewedPublisher PD
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