154 research outputs found

    In-beam fast-timing measurements in 103,105,107Cd

    Full text link
    Fast-timing measurements were performed recently in the region of the medium-mass 103,105,107Cd isotopes, produced in fusion evaporation reactions. Emitted gamma-rays were detected by eight HPGe and five LaBr3:Ce detectors working in coincidence. Results on new and re-evaluated half-lives are discussed within a systematic of transition rates. The 7/21+7/2_1^+ states in 103,105,107Cd are interpreted as arising from a single-particle excitation. The half-life analysis of the 11/21−11/2_1^- states in 103,105,107Cd shows no change in the single-particle transition strength as a function of the neutron number

    Exploring the logic of mobile search

    Get PDF
    After more than a decade of development work and hopes, the usage of mobile Internet has finally taken off. Now, we are witnessing the first signs of evidence of what might become the explosion of mobile content and applications that will be shaping the (mobile) Internet of the future. Similar to the wired Internet, search will become very relevant for the usage of mobile Internet. Current research on mobile search has applied a limited set of methodologies and has also generated a narrow outcome of meaningful results. This article covers new ground, exploring the use and visions of mobile search with a users' interview-based qualitative study. Its main conclusion builds upon the hypothesis that mobile search is sensitive to a mobile logic different than today's one. First, (advanced) users ask for accessing with their mobile devices the entire Internet, rather than subsections of it. Second, success is based on new added-value applications that exploit unique mobile functionalities. The authors interpret that such mobile logic involves fundamentally the use of personalised and context-based services

    Ruthenium polypyridyl complexes and their modes of interaction with DNA : is there a correlation between these interactions and the antitumor activity of the compounds?

    Get PDF
    Various interaction modes between a group of six ruthenium polypyridyl complexes and DNA have been studied using a number of spectroscopic techniques. Five mononuclear species were selected with formula [Ru(tpy) L1L2](2-n)?, and one closely related dinuclear cation of formula [{Ru(apy)(tpy)}2{l-H2N(CH2)6NH2}]4?. The ligand tpy is 2,20:60,200-terpyridine and the ligand L1 is a bidentate ligand, namely, apy (2,20-azobispyridine), 2-phenylazopyridine, or 2-phenylpyridinylmethylene amine. The ligand L2 is a labile monodentate ligand, being Cl-, H2O, or CH3CN. All six species containing a labile L2 were found to be able to coordinate to the DNA model base 9-ethylguanine by 1H NMR and mass spectrometry. The dinuclear cationic species, which has no positions available for coordination to a DNA base, was studied for comparison purposes. The interactions between a selection of four representative complexes and calf-thymus DNA were studied by circular and linear dichroism. To explore a possible relation between DNA-binding ability and toxicity, all compounds were screened for anticancer activity in a variety of cancer cell lines, showing in some cases an activity which is comparable to that of cisplatin. Comparison of the details of the compound structures, their DNA binding, and their toxicity allows the exploration of structure–activity relationships that might be used to guide optimization of the activity of agents of this class of compounds

    Identification of the crossing point at N=21 between normal and intruder configurations

    Get PDF
    The beta(-) decay of Mg-34 was used to study the Al-34 nucleus through. spectroscopy at the Isotope Separator On-Line facility of CERN. Previous studies identified two beta-decaying states in Al-34 having spin-parity assignments J(pi) = 4(-) dominated by the normal configuration pi(d(5/2))(-1)circle times nu(f(7/2)) and J(pi) = 1(+) by the intruder configuration pi(d(5/2))(-1) circle times nu(d(3/2))(-1) (f(7/2))(2). Their unknown ordering and relative energy have been the subject of debate for the placement of Al-34 inside or outside the N = 20 "island of inversion." We report here that the 1(+) intruder lies only 46.6 keV above the 4(-) ground state. In addition, a new half-life of T-1/2 = 44.9(4) ms, that is twice as long as the previously measured 20(10) ms, has been determined for Mg-34. Large-scale shell-model calculations with the recently developed SDPF-U-MIX interaction are compared with the new data and used to interpret the mechanisms at play at the very border of the N = 20 island of inversion.Peer reviewe

    Correction:Microwave gallium-68 radiochemistry for kinetically stable bis(thiosemicarbazone) complexes: Structural investigations and cellular uptake under hypoxia (Dalton Transactions (2016) 45 (144-155))

    Get PDF
    We report the microwave synthesis of several bis(thiosemicarbazones) and the rapid gallium-68 incorporation to give the corresponding metal complexes. These proved kinetically stable under ‘cold’ and ‘hot’ biological assays and were investigated using laser scanning confocal microscopy, flow cytometry and radioactive cell retention studies under normoxia and hypoxia. (68)Ga complex retention was found to be 34% higher in hypoxic cells than in normoxic cells over 30 min, further increasing to 53% at 120 min. Our data suggests that this class of gallium complexes show hypoxia selectivity suitable for imaging in living cells and in vivo tests by microPET in nude athymic mice showed that they are excreted within 1 h of their administration

    Synthesis, radiolabelling and in vitro imaging of multifunctional nanoceramics

    Get PDF
    Molecular imaging has become a powerful technique in preclinical and clinical research aiming towards the diagnosis of many diseases. In this work, we address the synthetic challenges in achieving lab‐scale, batch‐to‐batch reproducible copper‐64‐ and gallium‐68‐radiolabelled metal nanoparticles (MNPs) for cellular imaging purposes. Composite NPs incorporating magnetic iron oxide cores with luminescent quantum dots were simultaneously encapsulated within a thin silica shell, yielding water‐dispersible, biocompatible and luminescent NPs. Scalable surface modification protocols to attach the radioisotopes 64Cu (t1/2=12.7 h) and 68Ga (t1/2=68 min) in high yields are reported, and are compatible with the time frame of radiolabelling. Confocal and fluorescence lifetime imaging studies confirm the uptake of the encapsulated imaging agents and their cytoplasmic localisation in prostate cancer (PC‐3) cells. Cellular viability assays show that the biocompatibility of the system is improved when the fluorophores are encapsulated within a silica shell. The functional and biocompatible SiO2 matrix represents an ideal platform for the incorporation of 64Cu and 68Ga radioisotopes with high radiolabelling incorporation

    Beta-delayed proton emission from 20Mg

    Get PDF
    Beta-delayed proton emission from 20 Mg has been measured at ISOLDE, CERN, with the ISOLDE Decay Station (IDS) setup including both charged-particle and gamma-ray detection capabilities. A total of 27 delayed proton branches were measured including seven so far unobserved. An updated decay scheme, including three new resonances above the proton separation energy in 20 Na and more precise resonance energies, is presented. Beta-decay feeding to two resonances above the Isobaric Analogue State (IAS) in 20 Na is observed. This may allow studies of the 4032.9(2.4)keV resonance in 19 Ne through the beta decay of 20 Mg, which is important for the astrophysically relevant reaction 15O( α \alpha , γ \gamma )19Ne . Beta-delayed protons were used to obtain a more precise value for the half-life of 20 Mg, 91.4(1.0)ms

    Fast-timing study of the l -forbidden 12+→32+ M1 transition in Sn 129 FAST-TIMING STUDY of the l -FORBIDDEN ⋯ R. LICǎ et al.

    Get PDF
    © 2016 authors. Published by the American Physical Society.The levels in Sn129 populated from the ÎČ- decay of In129 isomers were investigated at the ISOLDE facility of CERN using the newly commissioned ISOLDE Decay Station (IDS). The lowest 12+ state and the 32+ ground state in Sn129 are expected to have configurations dominated by the neutron s12 (l=0) and d32 (l=2) single-particle states, respectively. Consequently, these states should be connected by a somewhat slow l-forbidden M1 transition. Using fast-timing spectroscopy we have measured the half-life of the 12+ 315.3-keV state, T12= 19(10) ps, which corresponds to a moderately fast M1 transition. Shell-model calculations using the CD-Bonn effective interaction, with standard effective charges and g factors, predict a 4-ns half-life for this level. We can reconcile the shell-model calculations to the measured T12 value by the renormalization of the M1 effective operator for neutron holes
    • 

    corecore