98 research outputs found
Proton-proton correlations observed in two-proton decay of 19Mg and 16Ne
Proton-proton correlations were observed for the two-proton decays of the ground states of 19Mg and 16Ne. The trajectories of the respective decay products, 17Ne+p+p and 14O+p+p, were measured by using a tracking technique with microstrip detectors. These data were used to reconstruct the angular correlations of fragments projected on planes transverse to the precursor momenta. The measured three-particle correlations reflect a genuine three-body decay mechanism and allowed us to obtain spectroscopic information on the precursors with valence protons in the sd shell.EURONS EC-I3MEC FPA2003-05958 FPA2006-13807-C02-0
Observation of narrow states in nuclei beyond the proton drip line: 15F and 16Ne
Two high-lying states in 15F and 16Ne, unbound with respect to one-proton (1p) and two-proton (2p) emissions, have been observed in the fragmentation of 17Ne at intermediate energies. They undergo mainly sequential emissions of protons via intermediate states in 14O and 15F and have decay energies of 7.8(2) and 7.6(2) MeV, respectively. The widths of the newly observed states in 15F and 16Ne are much smaller than the Wigner limits for single-particle configurations, of 0.4(4) and 0.8(+8-4) MeV, respectively. In addition, narrow widths of 0.2(2) MeV are derived for two other high-lying states in 15F with Qp of 4.9 and 6.4 MeV, which match features of the recently predicted narrow odd-parity 15F states with two valence protons in the sd shell. All energies and widths have been obtained by analyzing angular correlations of the decay products, p-p-14O and p-p-13N, whose trajectories have been measured by a tracking technique with silicon microstrip detectors.EURONS EC-I3España FPA2006-13807-C02-0
Tracing a phase transition with fluctuations of the largest fragment size: Statistical multifragmentation models and the ALADIN S254 data
A phase transition signature associated with cumulants of the largest
fragment size distribution has been identified in statistical
multifragmentation models and examined in analysis of the ALADIN S254 data on
fragmentation of neutron-poor and neutron-rich projectiles. Characteristics of
the transition point indicated by this signature are weakly dependent on the
A/Z ratio of the fragmenting spectator source. In particular, chemical
freeze-out temperatures are estimated within the range 5.9 to 6.5 MeV. The
experimental results are well reproduced by the SMM model.Comment: 7 pages, 3 figures, Proceedings of the International Workshop on
Multifragmentation and Related Topics (IWM2009), Catania, Italy, November
2009
Biomarkers in anal cancer: from biological understanding to stratified treatment
Squamous cell carcinomas of the anus and anal canal represent a model of a cancer and perhaps the first where level 1 evidence supported primary chemoradiotherapy (CRT) in treating locoregional disease with curative intent. The majority of tumours are associated with infection with oncogenic subtypes of human papilloma virus and this plays a significant role in their sensitivity to treatment. However, not all tumours are cured with CRT and there remain opportunities to improve outcomes in terms of oncological control and also reducing late toxicities. Understanding the biology of ASCC promises to allow a more personalised approach to treatment, with the development and validation of a range of biomarkers and associated techniques that are the focus of this review
Sources of mycosporine-like amino acids in planktonic Chlorella-bearing ciliates (Ciliophora)
Mycosporine-like amino acids (MAAs) are a family of secondary metabolites known to protect organisms exposed to solar UV radiation. We tested their distribution among several planktonic ciliates bearing Chlorella isolated from an oligo-mesotrophic lake in Tyrol, Austria. In order to test the origin of these compounds, the MAAs were assessed by high performance liquid chromatography in both the ciliates and their symbiotic algae.Considering all Chlorella-bearing ciliates, we found: (i) seven different MAAs (mycosporine-glycine, palythine, asterina-330, shinorine, porphyra-334, usujirene, palythene); (ii) one to several MAAs per species and (iii) qualitative and quantitative seasonal changes in the MAAs (e.g. in Pelagodileptus trachelioides). In all species tested, concentrations of MAAs were always <1% of ciliate dry weight.Several MAAs were also identified in the Chlorella isolated from the ciliates, thus providing initial evidence for their symbiotic origin. In Uroleptus sp., however, we found evidence for a dietary source of MAAs.Our results suggest that accumulation of MAAs in Chlorella-bearing ciliates represents an additional benefit of this symbiosis and an adaptation for survival in sunlit, UV-exposed waters
Invariant-mass and [gamma]-ray spectroscopy using secondary, radioactive ion beams
Coulomb excitation of secondary beams (5 < Z < 20) at energies
around 250 .1 MeV was explored at GSI. For low-lying states, 7-ray spectroscopy
was utilized, while high-lying excitations were investigated by
means of invariant-mass spectroscopy
Identification of Novel SNPs in Glioblastoma Using Targeted Resequencing
High-throughput sequencing opens avenues to find genetic variations that may be indicative of an increased risk for certain diseases. Linking these genomic data to other “omics” approaches bears the potential to deepen our understanding of pathogenic processes at the molecular level. To detect novel single nucleotide polymorphisms (SNPs) for glioblastoma multiforme (GBM), we used a combination of specific target selection and next generation sequencing (NGS). We generated a microarray covering the exonic regions of 132 GBM associated genes to enrich target sequences in two GBM tissues and corresponding leukocytes of the patients. Enriched target genes were sequenced with Illumina and the resulting reads were mapped to the human genome. With this approach we identified over 6000 SNPs, including over 1300 SNPs located in the targeted genes. Integrating the genome-wide association study (GWAS) catalog and known disease associated SNPs, we found that several of the detected SNPs were previously associated with smoking behavior, body mass index, breast cancer and high-grade glioma. Particularly, the breast cancer associated allele of rs660118 SNP in the gene SART1 showed a near doubled frequency in glioblastoma patients, as verified in an independent control cohort by Sanger sequencing. In addition, we identified SNPs in 20 of 21 GBM associated antigens providing further evidence that genetic variations are significantly associated with the immunogenicity of antigens
Mass measurement and isoscaling in Sn+Sn and Sn+Sn reactions at 600 AMeV
Isotopic effects in projectile spectator fragmentation at 600 AMeV have been investigated using data collected in recent experiments with SIS beams at the GSI laboratory and with the ALADiN forward-spectrometer. For this purpose, primary beams of 124Sn, as well as secondary beams of 124La and 107Sn produced at the FRS fragment separator have been used. Isoscaling in 124,107Sn+Sn reactions is investigated and results are compared with data taken with the INDRA multidetector for 12C+112,124Sn reactions
Coulomb breakup of 17Ne from the viewpoint of nuclear astrophysics
By the Coulomb breakup of 17Ne, the time-reversed reaction 15O(2p,γ)17Ne has been studied. This reaction might play an important role in the rp process, as a break-out reaction of the hot CNO cycle. The secondary 17Ne ion beam with an energy of 500 MeV/nucleon has been dissociated in a Pb target. The reaction products have been detected with the LAND-R3B experimental setup at GSI. The preliminary differential and integral Coulomb dissociation cross section sCoul has been determined, which then will be converted into a photo-absorption cross section sphoto, and a two-proton radiative capture cross section σcap. Additionally, information about the structure of the 17Ne, a potential two-proton halo nucleus, will be received. The analysis is in progress. \ua9 Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence
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