Study of transfer reaction properties with stable and unstable heavy ion beams

The main subject of this thesis is to show that transfer reactions with the neutron-rich unstable beams and the heavy targets could be very adequate for the production of the neutron-rich heavy nuclei. To that purpose, the measurement of $^{94}$Rb + $^{208}$Pb transfer reaction has been performed at the energy of about 30% above the Coulomb barrier, provided by the radioactive ion beam facility of CERN (HIE-ISOLDE). The high-resolution and high-efficiency experimental set-up consisted of a large $\gamma$-array MINIBALL, coupled to the CD fragment detector of wide angular range. From the measured particle-$\gamma$ and particle-$\gamma$-$\gamma$ coincidences, the characteristic $\gamma$ transitions were attributed to $^{207}$Pb, $^{208}$Pb, $^{209}$Pb and $^{210}$Pb, and their binary partners, the isotopes of Rb. Based on the attributed $\gamma$ transitions, the total cross sections in Pb isotopes were successfully constructed. In particular, in channels populated by transfer of neutrons from $^{94}$Rb beam to $^{208}$Pb target, the cross section of 138(8) mb was evaluated in $^{209}$Pb, and 41(7) mb in $^{210}$Pb. These significant values quantify the production of the moderately neutron-rich heavy nuclei for the first time in the transfer reaction induced by an unstable beam. The obtained results were fairly reproduced with the semi-classical model GRAZING, thus encouraging the use of the presented approach for the population of the neutron-rich heavy nuclei. This thesis strongly suggests that the presently available experimental techniques and radioactive ion beam intensities are very suitable to extend the reaction mechanism and the nuclear structure studies farther from the valley of stability

Analytical techniques for multiplex analysis of protein biomarkers

Katrlik, Jaroslav/0000-0002-2876-9298; Brun, Virginie/0000-0002-9098-8707; Pascual Garcia, Cesar/0000-0002-0526-2507; Burzynska-Pedziwiatr, Izabela/0000-0002-3629-0981; Corrales, Fernando/0000-0002-0231-5159; Martinez-Caceres, Eva M/0000-0002-6762-8025WOS: 000536384300001PubMed: 32427033Introduction: the importance of biomarkers for pharmaceutical drug development and clinical diagnostics is more significant than ever in the current shift toward personalized medicine. Biomarkers have taken a central position either as companion markers to support drug development and patient selection, or as indicators aiming to detect the earliest perturbations indicative of disease, minimizing therapeutic intervention or even enabling disease reversal. Protein biomarkers are of particular interest given their central role in biochemical pathways. Hence, capabilities to analyze multiple protein biomarkers in one assay are highly interesting for biomedical research. Areas covered: We here review multiple methods that are suitable for robust, high throughput, standardized, and affordable analysis of protein biomarkers in a multiplex format. We describe innovative developments in immunoassays, the vanguard of methods in clinical laboratories, and mass spectrometry, increasingly implemented for protein biomarker analysis. Moreover, emerging techniques are discussed with potentially improved protein capture, separation, and detection that will further boost multiplex analyses. Expert commentary: the development of clinically applied multiplex protein biomarker assays is essential as multi-protein signatures provide more comprehensive information about biological systems than single biomarkers, leading to improved insights in mechanisms of disease, diagnostics, and the effect of personalized medicine.European cooperation in science and technology - COST actionEuropean Cooperation in Science and Technology (COST) [CA16113]This paper was funded by the European cooperation in science and technology -COST action No. CA16113 - CliniMARK: `good biomarker practice' to increase the number of clinically validated biomarkers

Sub-barrier Fusion Of Si + Si Systems: Does The Deformation Of 28^{28}Si Play A Role?

International audienceThis contribution reports on the results of measurements of near- and sub-barrier fusion cross sections in the system 30Si+30Si performed at the Laboratori Nazionali di Legnaro of INFN. The 30Si beam of the XTU Tandem accelerator in the energy range of 47 - 90 MeV, was delivered on a metallic 30Si target (50 µg/cm2 ) enriched to 99.64 % in mass 30. A beam electrostatic de- flector was used for the detection of evaporation residues. The excitation function obtained for 30Si+30Si has been compared with the previous data on 28Si+28Si and Coupled Channels (CC) calculations using the M3Y+repulsion potential, taking into account the low lying 2+ and 3− excitations. Reproducing the low-energy 28Si+28Si excitation function was only possible by using a weak imaginary potential, probably simulating the oblate deformation of this nucleus. On the contrary, the data on 30Si+30Si are nicely reproduced by the CC calculations without any imaginary potential (30Si has a spherical shape). The astrophysical S-factor does not show a maximum, so that there is no evidence for hindrance in the measured energy range. The logarithmic derivative of the two excitation functions highlights the difference between the two systems. Even above the barrier the two systems behave differently. This is best seen by comparing the two barrier distributions where the high energy peak observed for 28Si+28Si is not found for 30Si+30Si. This is presumably due to the stronger couplings present in 28Si and further theoretical analyses are in progress

Study of fusion hindrance in the system 12^{12}C+24^{24}Mg

International audienceThe phenomenon of fusion hindrance may have important consequences on the nuclear processes occurring in astrophysical scenarios, if it is a general behaviour of heavy-ion fusion at extreme sub-barrier energies, including reactions involving lighter systems, e.g. reactions in the carbon and oxygen burning stages of heavy stars. The hindrance is generally identified by the observation of a maximum of the S-factor vs. energy. Whether there is an S-factor maximum at very low energies for systems with a positive fusion Q-value is an experimentally challenging question. Our aim has been to search evidence for fusion hindrance in 12C + 24Mg which is a medium-light systems with positive Q-value for fusion, besides the heavier cases where hindrance is recognised to be a general phenomenon. The experiment has been performed at the XTU Tandem accelerator of LNL by directly detecting the fusion evaporation residues at very forward angles. The excitation function has been extended down to sime10μb, i.e. 4 orders of magnitude lower than previous measurements and we observe that the S-factor develops a clear maximum vs. energy. Coupled-Channels calculations using a Woods-Saxon potential give a good account of the data near and above the barrier but over predict the cross sections at very low energies. Therefore the hindrance phenomenon is clearly recognised in 12 C + 24 Mg with an energy threshold that nicely fits the systematics in several medium-light systems. The fusion cross sections at the hindrance threshold show that the highest value (as=1.6mb) is indeed found for this system. It may be possible to extend the measurements further down in energy