497 research outputs found
TWO-PROTON RADIOACTIVITY: THE INTERESTING CASE OF 67Kr AND FURTHER STUDIES
We report on the observation of 67Kr that has been produced in an experiment
performed at the RIKEN/BigRIPS facility. The two-proton decay
of 67Kr has been evidenced and this nucleus is thus the fourth observed long
lived ground-state two-proton emitter, after 45Fe, 48Ni and 54Zn. In addition,
the decay of several isotopes in the mass region has been investigated.
While for previous cases of two-proton radioactivity, the theoretical models
could reproduce the measured data, this is not the case anymore for
67Kr. Two interpretations have been proposed to explain this discrepancy:
a transition between real two-proton and sequential decay or the influence
of deformation. These hypotheses will be tested in future experiments by
measuring the angular and energy correlations of the emitted proton
Bibliometric analysis as mesaure [sic] of long-term performance in pancreatic cancer research.
Introduction: Research on pancreatic cancer consists in basic, translational and clinical research. Bibliometric indexes as IF and H-Index have been proposed as measures of quality and performance for medical research. Our goal was to analyze the IF and the 5-years H-Index of the publications about pancreatic cancer research
transsphenoidal surgery for secreting pituitary microadenomas: results with intraoperative application of absolute alcohol
ABSTRACT
Background: Pituitary adenomas represent a quite frequent neurosurgical disease. Secreting pituitary adenomas are represented by PRL, GH, ACTH and TSH tumours; the rate of postoperative hormonal recurrence is not ineligible. Methods: We present 106 patients affected by secreting pituitary microadenomas operated through transsphenoidal approach from 1998 through to 2008; in 54 (group 1) patients, intraoperative absolute alcohol was applied, while in the other 52 (group 2) it was not employed. The indications and the intraoperative technique of absolute alcohol application are presented. Hormonal recurrence was treated by hypofractionated stereotactic radiotherapy and/or medical therapy. Results: Postoperative hormonal and clinical remission was achieved in 50 and 47 patients respectively of group one and group two. At the first follow-up control, after 3 months from surgery, no patient of both groups presented hormonal/clinical recurrence. Six months after surgery, no patient of group one presented hormonal recurrence, while two patients of group 2 presented hormonal recurrence. After 2 years from surgery, two patients of group 1 and 4 patients of group 2 presented hormonal recurrence. Three years after operation, hormonal hypersecretion recurred in three patients of group one and in six patients of group 2. At 5 years follow-up, six patients of group one and 8 of group two presented hormonal recurrence. Conclusions: Intraoperative application of absolute alcohol, in selected cases, resulted useful to achieve better results in secreting pituitary microadenomas concerning both postoperative hormonal recurrence and hormonal persistence
First observation of 54Zn and its decay by two-proton emission
The nucleus 54Zn has been observed for the first time in an experiment at the
SISSI/LISE3 facility of GANIL in the quasi-fragmentation of a 58Ni beam at 74.5
MeV/nucleon in a natNi target. The fragments were analysed by means of the
ALPHA-LISE3 separator and implanted in a silicon-strip detector where
correlations in space and time between implantation and subsequent decay events
allowed us to generate almost background free decay spectra for about 25
different nuclei at the same time. Eight 54Zn implantation events were
observed. From the correlated decay events, the half-life of 54Zn is determined
to be 3.2 +1.8/-0.8 ms. Seven of the eight implantations are followed by
two-proton emission with a decay energy of 1.48(2) MeV. The decay energy and
the partial half-life are compared to model predictions and allow for a test of
these two-proton decay models.Comment: 4 pages, 4 figures, accepted for publication in PR
Blurred femtoscopy in two-proton decay
We study the effects of final state interactions in two-proton emission by
nuclei. Our approach is based on the solution the time-dependent Schr\"odinger
equation. We show that the final relative energy between the protons is
substantially influenced by the final state interactions. We also show that
alternative correlation functions can be constructed showing large sensitivity
to the spin of the diproton system.Comment: 5 pages. 4 figures, accepted for publication in Phys. Lett.
First observation of 55,56Zn
In an experiment at the SISSI/LISE3 facility of GANIL, the most proton-rich
zinc isotopes 55,56Zn have been observed for the first time. The experiment was
performed using a high-intensity 58Ni beam at 74.5 MeV/nucleon impinging on a
nickel target. The identification of 55,56Zn opens the way to 54Zn, a good
candidate for two-proton radioactivity according to theoretical predictions.Comment: 2 pages, 1 figure, accepted for publication in Eur. Phys. J.
Decay of proton-rich nuclei between 39Ti and 49Ni
Decay studies of very neutron-deficient nuclei ranging from 39Ti to 49Ni have
been performed during a projectile fragmentation experiment at the GANIL/LISE3
separator. For all nuclei studied in this work, 39,40Ti, 42,43Cr, 46Mn,
45,46,47Fe and 49Ni, half-lives and decay spectra have been measured. In a few
cases, gamma coincidence measurements helped to successfully identify the
initial and final states of transitions. In these cases, partial decay scheme
are proposed. For the most exotic isotopes, 39Ti, 42Cr, 45Fe and 49Ni, which
are candidates for two-proton radioactivity from the ground state, no clear
evidence of this process is seen in our spectra and we conclude rather on a
delayed particle decay.Comment: 12 pages, 15 figures, submitted for publication in Eur. Phys. J.
Monosegment ALPPS hepatectomy preserving segment 4 for colorectal liver metastases : literature review and our experience
Peer reviewedPublisher PD
Beta-decay branching ratios of 62Ga
Beta-decay branching ratios of 62Ga have been measured at the IGISOL facility
of the Accelerator Laboratory of the University of Jyvaskyla. 62Ga is one of
the heavier Tz = 0, 0+ -> 0+ beta-emitting nuclides used to determine the
vector coupling constant of the weak interaction and the Vud quark-mixing
matrix element. For part of the experimental studies presented here, the
JYFLTRAP facility has been employed to prepare isotopically pure beams of 62Ga.
The branching ratio obtained, BR= 99.893(24)%, for the super-allowed branch is
in agreement with previous measurements and allows to determine the ft value
and the universal Ft value for the super-allowed beta decay of 62Ga
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