2,275 research outputs found

    Theoretical studies on structural and decay properties of Z=119Z=119 superheavy nuclei

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    In this manuscript, we analyze the structural properties of Z=119Z=119 superheavy nuclei in the mass range of 284 ≤\le A ≤\le 375 within the framework of deformed relativistic mean field theory (RMF) and calculate the binding energy, radii, quadrupole deformation parameter, separation energies and density profile. Further, a competition between possible decay modes such as α−\alpha-decay, β−\beta-decay and spontaneous fission (SF) of the isotopic chain of Z=119Z=119 superheavy nuclei under study is systematically analyzed within self-consistent relativistic mean field model. Moreover, our analysis confirmed that α−\alpha-decay is restricted within the mass range 284 ≤\leq A ≤\leq 296 and thus being the dominant decay channel in this mass range. However, for the mass range 297 ≤\leq A ≤\leq 375 the nuclei are unable to survive fission and hence SF is the principal mode of decay for these isotopes. There is no possibility of β−\beta-decay for the considered isotopic chain. In addition, we forecasted the mode of decay 284−296^{284-296}119 as one α\alpha chain from 284^{284}119 and 296^{296}119, two consistent α\alpha chains from 285^{285}119 and 295^{295}119, three consistent α\alpha chains from 286^{286}119 and 294^{294}119, four consistent alpha chains from 287^{287}119, six consistent alpha chains from 288−293^{288-293}119. Also from our analysis we inferred that for the isotopes 264−266,269^{264-266,269}Bh both α\alpha decay and SF are equally competent and can decay via either of these two modes. Thus, such studies can be of great significance to the experimentalists in very near future for synthesizing Z=119Z=119 superheavy nuclei.Comment: 14 pages, 6 figures. arXiv admin note: text overlap with arXiv:1611.00232, arXiv:1704.0315

    Structural and decay properties of Z=132,138Z=132,138 superheavy nuclei

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    In this paper, we analyze the structural properties of Z=132Z=132 and Z=138Z=138 superheavy nuclei within the ambit of axially deformed relativistic mean-field framework with NL3∗3^{*} parametrization and calculate the total binding energies, radii, quadrupole deformation parameter, separation energies, density distributions. We also investigate the phenomenon of shape coexistence by performing the calculations for prolate, oblate and spherical configurations. For clear presentation of nucleon distributions, the two-dimensional contour representation of individual nucleon density and total matter density has been made. Further, a competition between possible decay modes such as α\alpha-decay, β\beta-decay and spontaneous fission of the isotopic chain of superheavy nuclei with Z=132Z=132 within the range 312 ≤\le A ≤\le 392 and 318 ≤\le A ≤\le 398 for Z=138Z=138 is systematically analyzed within self-consistent relativistic mean field model. From our analysis, we inferred that the α\alpha-decay and spontaneous fission are the principal modes of decay in majority of the isotopes of superheavy nuclei under investigation apart from β\beta decay as dominant mode of decay in 318−322138^{318-322}138 isotopes.Comment: 16 pages, 10 figures , 8 table

    Seasonality of cognitive function in the general population:the Rotterdam Study

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    Seasonal variation in cognitive function and underlying cerebral hemodynamics in humans has been suggested, but not consistently shown in previous studies. We assessed cognitive function in 10,276 participants from the population-based Rotterdam Study, aged 45 years and older without dementia, at baseline and at subsequent visits between 1999 and 2016. Seasonality of five cognitive test scores and of a summary measure of global cognition were determined, as well as of brain perfusion. Using linkage with medical records, we also examined whether a seasonal variation was present in clinical diagnoses of dementia. We found a seasonal variation of global cognition (0.05 standard deviations [95% confidence interval: 0.02–0.08]), the Stroop reading task, the Purdue Pegboard test, and of the delayed world learning test, with the best performance in summer months. In line with these findings, there were fewer dementia diagnoses of dementia in spring and summer than in winter and fall. We found no seasonal variation in brain perfusion. These findings support seasonality of cognition, albeit not explained by brain perfusion. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11357-021-00485-0

    Formation of Medium-Heavy Elements in Rapid Neutron Capture Process

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    We predict the neutron drip-line and simulate the r—process path for Cu — Sn, based on the calculation of binding energy in the frame-work of relativistic and non-relativistic mean field formalisms. We also compare the quadrupole deformation parameterβ2, and one neutron separation energy Sn of these isotopic series with the results of finite range droplet model (FRDM) prediction. the results produced by RMF and ShF are comparable to each other and also agreeable with the FRDM model

    Skin autofluorescence, reflecting accumulation of advanced glycation end products, and the risk of dementia in a population-based cohort

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    Conditions such as hyperglycemia and oxidative stress lead to the formation of advanced glycation end products (AGEs), which are harmful compounds that have been implicated in dementia. Within the Rotterdam Study, we measured skin AGEs as skin autofluorescence, reflecting long-term accumulation of AGEs, and determined their association with the risk of dementia and with brain magnetic resonance imaging (MRI) measures. Skin autofluorescence was measured between 2013 and 2016 in 2922 participants without dementia. Of these, 1504 also underwent brain MRI, on which measures of brain atrophy and cerebral small vessel disease were assessed. All participants were followed for the incidence of dementia until 2020. Of 2922 participants (mean age 72.6 years, 57% women), 123 developed dementia. Higher skin autofluorescence (per standard deviation) was associated with an increased risk of dementia (hazard ratio 1.21 [95% confidence interval 1.01–1.46]) and Alzheimer’s disease (1.19 [0.97–1.47]), independently of age and other studied potential confounders. Stronger effects were seen in apolipoprotein E (APOE) ε4 carriers (1.34 [0.98–1.82]) and in participants with diabetes (1.35 [0.94–1.94]). Participants with higher skin autofluorescence levels also had smaller total brain volumes and smaller hippocampus volumes on MRI, and they had more often lacunes. These results suggest that AGEs may be involved in dementia pathophysiology.</p
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