| 1. |
- Sanchez-Vega, M., et al.
(author)
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Studies of quadrupole collectivity in the γ -soft 106Ru
- 2008
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In: European Physical Journal A. - 1434-6001 .- 1434-601X. ; 35:2, s. 159-165
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Journal article (peer-reviewed)abstract
- Various alternative models were used to describe the structure of 106Ru . For example, the General Collective Model (GCM) predicts shape-coexistence for 106Ru with a spherical and a triaxial minimum and strongly mixed structures, while in the IBA-2 calculations, where 106Ru was considered as transitional from vibrational U(5) to γ -soft O(6) , no need was found to include the shape-coexisting configurations. In order to provide additional constraints on the model interpretations, we have applied the Advanced Time-Delayed (ATD) βγγ(t) method to measure the level lifetimes of the excited levels in 106Ru . The new results include the half-lives of T 1/2 = 183(3) ps and 7.5(30)ps for the 2+ 1 and 2+ 2 states, respectively.
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| 2. |
- Araujo, C. M., et al.
(author)
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Electrical resistivity, MNM transition and band-gap narrowing of cubic GaN : Si
- 2002
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In: Microelectronics Journal. - 0026-2692. ; 33:4, s. 365-369
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Journal article (peer-reviewed)abstract
- The electrical resistivity of the Si-donor cubic GaN is investigated theoretically at low temperature. The critical impurity concentration, N-c, for the metal-nonmetal transition is estimated in three different ways: from using the generalized Drude approach (GDA) for the resistivity; from the vanishing of the chemical potential calculated using the dielectric function model with a Lorentz-Lorenz correction; from finding the crossing point between the energy in the insulating and metallic states. The bandgap narrowing (BGN) has been determined theoretically and experimentally above the MNM transition, The experimental data have been obtained with photoluminescence measurements. Theoretical and experimental results are in rough agreement in the range of impurity concentration of interest.
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| 3. |
- Fernandez, J. R. L., et al.
(author)
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Electrical resistivity and band-gap shift of Si-doped GaN and metal-nonmetal transition in cubic GaN, InN and AlN systems
- 2001
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In: Journal of Crystal Growth. - 0022-0248 .- 1873-5002. ; 231:3, s. 420-427
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Journal article (peer-reviewed)abstract
- The critical impurity concentration N-c of the metal-nonmetal (MNM) transition for the cubic GaN, InN and AIN systems. is calculated using the following two different criteria: vanishing of the donor binding energy and the crossing point between the energies in the metallic and insulating phases. A dielectric function model with a Lorentz-Lorenz correction is used for the insulating phase. The InN presents an order of magnitude increase in N-c as compared to the other two systems. The electrical resistivity of the Si-donor system GaN is investigated theoretically and experimentally from room temperature down to 10K. It presents a metallic character above a certain high impurity concentration identified as N-c. The samples were grown by plasma assisted molecular beam epitaxy (MBE) on GaAs (0 0 1) substrate. The model calculation is carried out from a recently proposed generalized Drude approach (GDA) presenting a very good estimation for the metallic region. The band-gap shift (BGS) of Si-doped GaN has also been investigated above the MNM transition where this shift is observed. Theoretical and experimental results have a rough agreement in a range of impurity concentration of interest.
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| 4. |
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| 5. |
- Bird, D. M., et al.
(author)
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Dynamics of the spin transition in the adsorption of hydrogen atoms on metals
- 2004
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In: Surface Science. - : Elsevier BV. - 0039-6028. ; 566-568:1-3 part 2, s. 761-766
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Journal article (peer-reviewed)abstract
- The time-dependent, mean-field Newns-Anderson model is solved in the wide-band limit. Equations for the time-evolution of the occupation of the spin-dependent adsorbate levels and for the rate of non-adiabatic energy transfer from adsorbate to substrate are derived. Numerical solutions are obtained in the region of space close to the transition point between spin-polarised and non-polarised ground states, for model parameters that correspond to an H-atom incident on the Cu(111) surface. Away from the spin transition the non-adiabatic energy transfer is in close agreement with the nearly-adiabatic limit. Near the transition, non-adiabatic effects are large and the nearly-adiabatic approximation fails.
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| 6. |
- Cederwall, Bo, et al.
(author)
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Evidence for a spin-aligned neutron-proton paired phase from the level structure of 92Pd
- 2011
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 469:7328, s. 68-71
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Journal article (peer-reviewed)abstract
- Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work(1) that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing(2-6), in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus Pd-92. Gamma rays emitted following the Ni-58(Ar-36,2n)Pd-92 fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution c-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction(2-6). We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling(7,8)) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.
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| 7. |
- Cibula, D., et al.
(author)
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Completion of radical hysterectomy does not improve survival of patients with cervical cancer and intraoperatively detected lymph node involvement : ABRAX international retrospective cohort study
- 2021
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In: European Journal of Cancer. - : Elsevier BV. - 0959-8049. ; 143, s. 88-100
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Journal article (peer-reviewed)abstract
- Background: The management of cervical cancer patients with intraoperative detection of lymph node involvement remains controversial. Since all these patients are referred for (chemo)radiation after the surgery, the key decision is whether radical hysterectomy should be completed as originally planned, taking into account an additional morbidity associated with extensive surgical dissection prior to adjuvant treatment. The ABRAX study investigated whether completing a radical uterine procedure is associated with an improved oncological outcome of such patients. Patients and methods: We performed retrospective analyses of 515 cervical cancer patients (51 institutions, 19 countries) who were referred for primary curative surgery between 2005 and 2015 (stage IA–IIB, common tumour types) in whom lymph node involvement was detected intraoperatively. Patients were stratified according to whether the planned uterine surgery was completed (COMPL group, N = 361) or abandoned (ABAND group, N = 154) to compare progression-free survival. Definitive chemoradiation was given to 92.9% patients in the ABAND group and adjuvant (chemo)radiation or chemotherapy to 91.4% of patients in the COMPL group. Results: The risks of recurrence (hazard ratio [HR] 1.154, 95% confidence intervals [CI] 0.799–1.666, P = 0.45), pelvic recurrence (HR 0.836, 95% CI 0.458–1.523, P = 0.56), or death (HR 1.064, 95% CI 0.690–1.641, P = 0.78) were not significantly different between the two groups. No subgroup showed a survival benefit from completing radical hysterectomy. Disease-free survival reached 74% (381/515), with a median follow-up of 58 months. Prognostic factors were balanced between the two groups. FIGO stage and number of pelvic lymph nodes involved were significant prognostic factors in the whole study cohort. Conclusion: We showed that the completion of radical hysterectomy does not improve survival in patients with intraoperatively detected lymph node involvement, regardless of tumour size or histological type. If lymph node involvement is confirmed intraoperatively, abandoning uterine radical procedure should be considered, and the patient should be referred for definitive chemoradiation. Clinical trials identifier: NCT04037124.
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| 8. |
- deSouza, Nandita M., et al.
(author)
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Validated imaging biomarkers as decision-making tools in clinical trials and routine practice: current status and recommendations from the EIBALL* subcommittee of the European Society of Radiology (ESR)
- 2019
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In: Insights into Imaging. - : SPRINGEROPEN. - 1869-4101. ; 10:1
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Journal article (peer-reviewed)abstract
- Observer-driven pattern recognition is the standard for interpretation of medical images. To achieve global parity in interpretation, semi-quantitative scoring systems have been developed based on observer assessments; these are widely used in scoring coronary artery disease, the arthritides and neurological conditions and for indicating the likelihood of malignancy. However, in an era of machine learning and artificial intelligence, it is increasingly desirable that we extract quantitative biomarkers from medical images that inform on disease detection, characterisation, monitoring and assessment of response to treatment. Quantitation has the potential to provide objective decision-support tools in the management pathway of patients. Despite this, the quantitative potential of imaging remains under-exploited because of variability of the measurement, lack of harmonised systems for data acquisition and analysis, and crucially, a paucity of evidence on how such quantitation potentially affects clinical decision-making and patient outcome. This article reviews the current evidence for the use of semi-quantitative and quantitative biomarkers in clinical settings at various stages of the disease pathway including diagnosis, staging and prognosis, as well as predicting and detecting treatment response. It critically appraises current practice and sets out recommendations for using imaging objectively to drive patient management decisions.
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| 9. |
- Falgarone, E., et al.
(author)
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CH+(1-0) and 13CH+(1-0) absorption lines in the direction of massive star-forming regions
- 2010
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 521:1
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Journal article (peer-reviewed)abstract
- We report the detection of the ground-state rotational transition of the methylidyne cation CH+ and its isotopologue (CH+)-C-13 toward the remote massive star-forming regions W33A, W49N, and W51 with the HIFI instrument onboard the Herschel satellite. Both lines are seen only in absorption against the dust continuum emission of the star-forming regions. The CH+ absorption is saturated over almost the entire velocity ranges sampled by the lines-of-sight that include gas associated with the star-forming regions (SFR) and Galactic foreground material. The CH+ column densities are inferred from the optically thin components. A lower limit of the isotopic ratio [(CH+)-C-12]/[(CH+)-C-13]> 35.5 is derived from the absorptions of foreground material toward W49N. The column density ratio, N(CH+)/N(HCO+), is found to vary by at least a factor 10, between 4 and > 40, in the Galactic foreground material. Line-of-sight 12CH+ average abundances relative to total hydrogen are estimated. Their average value, N(CH+)/NH > 2.6 x 10(-8), is higher than that observed in the solar neighborhood and confirms the high abundances of CH+ in the Galactic interstellar medium. We compare this result to the predictions of turbulent dissipation regions (TDR) models and find that these high abundances can be reproduced for the inner Galaxy conditions. It is remarkable that the range of predicted N(CH+)/ N(HCO+) ratios, from 1 to similar to 50, is comparable to that observed.
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| 10. |
- Gerin, M., et al.
(author)
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Hydride spectroscopy of the diffuse interstellar medium: new clues on the gas fraction in molecular form and cosmic ray ionization rate in relation to H-3(+)
- 2012
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In: Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. - : The Royal Society. - 1364-503X .- 1471-2962. ; 370:1978, s. 5174-5185
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Journal article (peer-reviewed)abstract
- The Herschel-guaranteed time key programme PRobing InterStellar Molecules with Absorption line Studies (PRISMAS)(1) is providing a survey of the interstellar hydrides containing the elements C, O, N, F and Cl. As the building blocks of interstellar molecules, hydrides provide key information on their formation pathways. They can also be used as tracers of important physical and chemical properties of the interstellar gas that are difficult to measure otherwise. This paper presents an analysis of two sight-lines investigated by the PRISMAS project, towards the star-forming regions W49N and W51. By combining the information extracted from the detected spectral lines, we present an analysis of the physical properties of the diffuse interstellar gas, including the electron abundance, the fraction of gas in molecular form, and constraints on the cosmic ray ionization rate and the gas density.
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