The rapid shape change in Zr isotopes near neutron number N=60 is identified to be caused by type II shell evolution associated with massive proton excitations to its 0g_{9/2} orbit, and is shown to be a quantum phase transition. Monte Carlo shell-model calculations are carried out for Zr isotopes of N=50-70 with many configurations spanned by eight proton orbits and eight neutron orbits. Energy levels and B(E2) values are obtained within a single framework in good agreement with experiment, depicting various shapes in going from N=50 to 70. The novel coexistence of prolate and triaxial shapes is suggested.

Background: Type II shell evolution has recently been identified as a microscopic cause for nuclear shape coexistence.

The altered N-glycosylation of glycoproteins has been suggested to play an important role in the behavior of malignant cells. Using glycomics technology, we attempted to determine the specific and detailed N-glycan profile for hepatocellular carcinoma (HCC) and investigate the prognostic capabilities. From 1999 to 2011, 369 patients underwent primary curative hepatectomy in our facility and were followed up for a median of 60.7 months. As normal controls, 26 living Japanese related liver transplantation donors were selected not infected by hepatitis B and C virus. Their mean age was 40.0 and 15 (57.7%) were male. We used a glycoblotting method to purify N-glycans from preoperative blood samples from this cohort (10 lL serum) which were then identified and quantified using mass spectrometry (MS). Correlations between the N-glycan levels and the clinicopathologic characteristics and outcomes for these patients were evaluated. Our analysis of the relative areas of all the sugar peaks identified by MS, totaling 67 N-glycans, revealed that a proportion had higher relative areas in the HCC cases compared with the normal controls. Fourteen of these molecules had an area under the curve of greater than 0.80. Analysis of the correlation between these 14 N-glycans and surgical outcomes by univariate and multivariate analysis identified G2890 (m/z value, 2890.052) as a significant recurrence factor and G3560 (m/z value, 3560.295) as a significant prognostic factor. G2890 and G3560 were found to be strongly correlated with tumor number, size, and vascular invasion. Conclusion: Quantitative glycoblotting based on whole serum N-glycan profiling is an effective approach to screening for new biomarkers. The G2890 and G3560 N-glycans determined by tumor glycomics appear to be promising biomarkers for malignant behavior in HCCs. (HEPATOLOGY 2013;57:2314-2325 H epatocellular carcinoma (HCC) is a common and fatal malignancy with a worldwide occurrence.1 Liver resection has shown the highest level of control among the local treatments for HCC and is associated with a good survival rate.2,3 However, the recurrence rates for HCC are still high even when a curative hepatectomy is performed. 4 Many factors associated with the prognosis and recurrence of HCC have now been reported. Vascular invasion of the portal vein and/or hepatic vein and tumor differentiation are important factors affecting survival and recurrence in HCC cases after a hepatectomy. 5,6 However, microvascular invasion and differentiation can only be detected by pathological examination just after a hepatectomy, and cannot be diagnosed preoperatively, and thus cannot be identified preoperatively either. Hence, the serum biomarkers alpha-fetoprotein (AFP) and protein induced by vitamin K absence-II (PIVKA-II) are used as prognostic markers 7,8 and also as surrogate markers for microvascular invasion and tumor differentiation.9,10 AFP is associated with grade differentiation, 11 whereas PIVKA-II is related to vascularAbbreviations: AFP, alpha-fetoprotein; AFP-L3, lens cul...

Rapid shape changes are observed for neutron-rich nuclei with A around 100. In particular, a sudden onset of ground-state deformation is observed in the Zr and Sr isotopic chains at N=60: low-lying states in N≤58 nuclei are nearly spherical, while those with N≥60 have a rotational character. Nuclear lifetimes as short as a few ps can be measured using fast-timing techniques with LaBr 3 (Ce)-scintillators, yielding a key ingredient in the systematic study of the shape evolution in this region. We used neutron-induced fission of 241 Pu and 235 U to study lifetimes of excited states in fission fragments in the A∼100 region with the EXILL-FATIMA array located at the PF1B cold neutron beam line at the Institut Laue-Langevin. In particular, we applied the generalized centroid difference method to deduce lifetimes of low-lying states for the nuclei 98 Zr (N=58), 100 Zr and 102 Zr (N≥60). The results are discussed in the context of the presumed phase transition in the Zr chain by comparing the experimental transition strengths with the theoretical calculations using the Interacting Boson Model and the Monte Carlo Shell Model.

The lifetimes of first excited 2 + , 4 + and 6 + states in 98 Zr were measured with the Recoil-Distance Doppler-Shift method in an experiment performed at GANIL. Excited states in 98 Zr were populated using the fission reaction between a 6.2 MeV/u 238 U beam and a 9 Be target. The γ rays were detected with the EXOGAM array in correlation with the fission fragments identified in mass and atomic number in the VAMOS++ spectrometer. Our result shows very small B(E2; 2 + 1 → 0 + 1 ) value in 98 Zr thereby confirming the very sudden onset of collectivity at N = 60. The experimental results are compared to large-scale Monte Carlo Shell model and beyond mean field calculations. The present results indicate coexistence of two additional deformed shapes in this nucleus along with the spherical ground state.The study of various modes of excitations and the associated evolution of nuclear shapes along spin and isospin axes in atomic nuclei is one of the fundamental quests in nuclear physics. While nuclei with "magic numbers" of protons and/or neutrons have spherical ground states, as one moves away, the polarizing effect of added nucleons leads to deformation. Throughout the nuclear landscape, this onset of deformation is usually a gradual process, however in neutron rich nuclei around mass A ∼ 100 the shape change is rather drastic and abrupt. The ground states of Sr and Zr isotopes with N ranging from the magic number N = 50 up to N < 60 are weakly deformed, however, they undergo a rapid shape transition from nearly spherical to well deformed prolate deformations as N = 60 is approached. The sudden nature of shape transition in Sr and Zr isotopes is evident from the abrupt changes in the two neutron separation energies [1] and mean-square charge radii [2, 3], but also from the excitation energies of 2 + 1 states and B(E2) values [4]. On the other hand, in isotopes with Z ≥ 42 the shape change is rather gradual [1,5] showing also characteristic signatures of triaxiality. This strong dependence of the observed spectroscopic properties, both on the number of protons and neutrons, makes the neutron-rich A ∼ 100 nuclei an excellent mass region for testing various theoretical models.Many experimental and theoretical studies have already been reported on the structure of these nuclei. More specifically for the Zr isotopes, the onset of deformation at N = 60 has been described by a number of theoretical models [6][7][8][9][10][11][12][13][14][15][16][17][18][19], however, none of the models have been able to successfully reproduce the aforementioned rapid change. Very recently, the abrupt shape changes were correctly described by large-scale Monte-Carlo Shell Model (MCSM) calculations [20,21]. In the so-called type-II shell evolution scenario, the (prolate) deformed states in the isotopes with N ≥ 60 are associated with proton excitations to the 0g 9/2 orbital. Driven by the central and tensor components of the effective (proton-neutron) interactions, these excitations result in a lowering and subsequent filling of the neutron 0g ...