4,417 research outputs found
Information theory of quantum systems with some hydrogenic applications
The information-theoretic representation of quantum systems, which
complements the familiar energy description of the density-functional and
wave-function-based theories, is here discussed. According to it, the internal
disorder of the quantum-mechanical non-relativistic systems can be quantified
by various single (Fisher information, Shannon entropy) and composite (e.g.
Cramer-Rao, LMC shape and Fisher-Shannon complexity) functionals of the
Schr\"odinger probability density. First, we examine these concepts and its
application to quantum systems with central potentials. Then, we calculate
these measures for hydrogenic systems, emphasizing their predictive power for
various physical phenomena. Finally, some recent open problems are pointed out.Comment: 9 pages, 3 figure
Quantum Entanglement in -Spherium
There are very few systems of interacting particles (with continuous
variables) for which the entanglement of the concomitant eigenfunctions can be
computed in an exact, analytical way. Here we present analytical calculations
of the amount of entanglement exhibited by -states of \emph{spherium}. This
is a system of two particles (electrons) interacting via a Coulomb potential
and confined to a -sphere (that is, to the surface of a -dimensional
ball). We investigate the dependence of entanglement on the radius of the
system, on the spatial dimensionality , and on energy. We find that
entanglement increases monotonically with , decreases with , and also
tends to increase with the energy of the eigenstates. These trends are
discussed and compared with those observed in other two-electron atomic-like
models where entanglement has been investigated.Comment: 14 pages, 6 figures. J. Phys. A (2015). Accepte
Quantum entanglement in exactly soluble atomic models: The Moshinsky model with three electrons, and with two electrons in a uniform magnetic field
We investigate the entanglement-related features of the eigenstates of two exactly soluble atomic models: a one-dimensional three-electron Moshinsky model, and a three-dimensional two-electron Moshinsky system in an external uniform magnetic field. We analytically compute the amount of entanglement exhibited by the wavefunctions corresponding to the ground, first and second excited states of the three-electron model. We found that the amount of entanglement of the system tends to increase with energy, and in the case of excited states we found a finite amount of entanglement in the limit of vanishing interaction. We also analyze the entanglement properties of the ground and first few excited states of the two-electron Moshinsky model in the presence of a magnetic field. The dependence of the eigenstates' entanglement on the energy, as well as its behaviour in the regime of vanishing interaction, are similar to those observed in the three-electron system. On the other hand, the entanglement exhibits a monotonically decreasing behavior with the strength of the external magnetic field. For strong magnetic fields the entanglement approaches a finite asymptotic value that depends on the interaction strength. For both systems studied here we consider a perturbative approach in order to shed some light on the entanglement's dependence on energy and also to clarify the finite entanglement exhibited by excited states in the limit of weak interactions. As far as we know, this is the first work that provides analytical and exact results for the entanglement properties of a three-electron model.Fil: Bouvrie, P. A.. Universidad de Granada; EspañaFil: Majtey, Ana Paula. Universidad de Granada; España. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Plastino, Ángel Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata; ArgentinaFil: Sánchez Moreno, P.. Universidad de Granada; EspañaFil: Dehesa, J. S.. Universidad de Granada; Españ
Changes in cell/tissue organization and peroxidase activity as markers for early detection of graft incompatibility in peach/plum combinations
9 páginas, 3 figuras, 4 tablas -- PAGS nros. 9-17Changes in cell and tissue organization and in peroxidase activity have been analyzed to find early markers to predict graft incompatibility occurrence in peach/plum combinations (Prunus persica/Prunus spp.) at 5 months after grafting in the dormancy period. Different compatible and incompatible peach/plum grafts were grown for 5 months in a nursery. The cellular study of the graft interface revealed structural changes associated with graft incompatibility symptoms. The main structural features were cambium cell disorganization, less differentiation of vascular tissues, degeneration of phloem and xylem cells, and accumulation of phenols at the graft interface after 5 months of graft development. The peroxidase study was performed during dormancy and the vegetative growth period, and revealed a significant increase in peroxidase activity in the incompatible unions, with significant differences between compatible and incompatible grafts. Analysis of gel profiles of nonbudded rootstocks and scions revealed an anodal isoperoxidase band [relative front (Rf) = 0.48] present in scions and compatible rootstocks, and another isoperoxidase band (Rf = 0.53) only present in the incompatible rootstocks. Our results show that the analysis of cell organization to detect early structural events and the evaluation of peroxidase activity at graft unions constituted feasible and convenient methods for early diagnosis of graft incompatibility. Also, it was suggested that the presence of band Rf = 0.48 in plum rootstocks and peach cultivars could be used as a marker to predict graft compatibility for peach scions and plum rootstocksFinancial support was provided by Comisión Interministerial de Ciencia y Tecnología (project nos. AGL2005-05533 and AGL2008-00283/AGR, partially founded by BFU2008-00203 and AGL2008-04255), by the CONSID-DGA A 44, and by a fellowship granted to O.Z. from the Agencia Española de Cooperación Internacional (AECI)Peer reviewe
Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide Versus Dolutegravir/Abacavir/Lamivudine in Antiretroviral-Naive Adults (SYMTRI): A Multicenter Randomized Open-Label Study (PReEC/RIS-57)
Background. Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) is the reference for combination therapy
based on protease inhibitors due to its efficacy, tolerability, and convenience. Head-to-head randomized comparisons between
D/C/F/TAF and combination therapy based on integrase inhibitors in antiretroviral-naive patients are lacking.
Methods. Adult (>18 years old) human immunodeficiency virus-infected antiretroviral-naive patients (HLA-B∗5701 negative
and hepatitis B virus negative), with viral load (VL) ≥500 c/mL, were centrally randomized to initiate D/C/F/TAF or dolutegravir/
abacavir/lamivudine (DTG/3TC/ABC) after stratifying by VL and CD4 count. Clinical and analytical assessments were performed
at weeks 0, 4, 12, 24, and 48. The primary endpoint was VL <50 c/mL at week 48 in the intention-to-treat (ITT)-exposed population
(US Food and Drug Administration snapshot analysis, 10% noninferiority margin).
Results. Between September 2018 and 2019, 316 patients were randomized and 306 patients were included in the ITT-exposed
analysis (151 D/C/F/TAF and 155 DTG/3TC/ABC). Almost all (94%) participants were male and their median age was 35 years.
Forty percent had a baseline VL >100 000 copies/mL, and 13% had <200 CD4 cells/μL. Median weight was 73 kg and median body
mass index was 24 kg/m2
. At 48 weeks, 79% (D/C/F/TAF) versus 82% (DTG/3TC/ABC) had VL <50 c/mL (difference, −2.4%; 95%
confidence interval [CI], −11.3 to 6.6). Eight percent versus four percent experienced virologic failure but no resistance-associated
mutations emerged. Four percent versus six percent had drug discontinuation due to adverse events. In the per-protocol analysis,
94% versus 96% of patients had VL <50 c/mL (difference, −2%; 95% CI, −8.1 to 3.5). There were no differences in CD4 cell count or
weight changes.
Conclusions. We could not demonstrate the noninferiority of D/C/F/TAF relative to DTG/ABC/3TC as initial antiretroviral
therapy, although both regimens were similarly well tolerated
Bisphenol A induces coronary endothelial cell necroptosis by activating RIP3/CamKII dependent pathway.
Epidemiological studies link long term exposure to xenoestrogen Bisphenol-A to adverse cardiovascular effects. Our previous results show that BPA induces hypertension by a mechanism involving CamKII activation and increased redox stress caused by eNOS uncoupling. Recently, CamKII sustained activation has been recognized as a central mediator of programmed cell death in cardiovascular diseases, including necroptosis. However, the role of necroptosis in cardiac response to BPA had not yet been explored. Mice exposed to BPA for 16 weeks showed altered heart function, electrical conduction, and increased blood pressure. Besides, a stress test showed ST-segment depression, indicative of cardiac ischemia. The hearts exhibited cardiac hypertrophy and reduced vascularization, interstitial edema, and large hemorrhagic foci accompanied by fibrinogen deposits. BPA initiated a cardiac inflammatory response, up-regulation of M1 macrophage polarization, and increased oxidative stress, coinciding with the increased expression of CamKII and the necroptotic effector RIP3. In addition, cell death was especially evident in coronary endothelial cells within hemorrhagic areas, and Evans blue extravasation indicated a vascular leak in response to Bisphenol-A. Consistent with the in vivo findings, BPA increased the necroptosis/apoptosis ratio, the expression of RIP3, and CamKII activation in endothelial cells. Necrostatin-1, an inhibitor of necroptosis, alleviated BPA induced cardiac dysfunction and prevented the inflammatory and hemorrhagic response in mice. Mechanistically, silencing of RIP3 reversed BPA-induced necroptosis and CamKII activation in endothelial cells, while inhibition of CamKII activation by KN-93 had no effect on RIP3 expression but decreased necroptotic cell death suggesting that BPA induced necroptosis is mediated by a RIP 3/CamKII dependent pathway. Our results reveal a novel pathogenic role of BPA on the coronary circulation. BPA induces endothelial cell necroptosis, promotes the weakening of coronary vascular wall, which caused internal ventricular hemorrhages, delaying the reparative process and ultimately leading to cardiac dysfunction.post-print4043 K
- …