1,993 research outputs found
A possible cosmological application of some thermodynamic properties of the black body radiation in dimensional Euclidean spaces
In this work we present the generalization of some thermodynamic properties
of the black body radiation (BBR) towards an dimensional Euclidean space.
For this case the Planck function and the Stefan-Boltzmann law have already
been given by Landsberg and de Vos and some adjustments by Menon and Agrawal.
However, since then no much more has been done on this subject and we believe
there are some relevant aspects yet to explore. In addition to the results
previously found we calculate the thermodynamic potentials, the efficiency of
the Carnot engine, the law for adiabatic processes and the heat capacity at
constant volume. There is a region at which an interesting behavior of the
thermodynamic potentials arise, maxima and minima appear for the BBR
system at very high temperatures and low dimensionality, suggesting a possible
application to cosmology. Finally we propose that an optimality criterion in a
thermodynamic framework could have to do with the nature of the universe.Comment: 9 pages, 8 figure
Artificial escape from XCI by DNA methylation editing of the CDKL5 gene.
A significant number of X-linked genes escape from X chromosome inactivation and are associated with a distinct epigenetic signature. One epigenetic modification that strongly correlates with X-escape is reduced DNA methylation in promoter regions. Here, we created an artificial escape by editing DNA methylation on the promoter of CDKL5, a gene causative for an infantile epilepsy, from the silenced X-chromosomal allele in human neuronal-like cells. We identify that a fusion of the catalytic domain of TET1 to dCas9 targeted to the CDKL5 promoter using three guide RNAs causes significant reactivation of the inactive allele in combination with removal of methyl groups from CpG dinucleotides. Strikingly, we demonstrate that co-expression of TET1 and a VP64 transactivator have a synergistic effect on the reactivation of the inactive allele to levels >60% of the active allele. We further used a multi-omics assessment to determine potential off-targets on the transcriptome and methylome. We find that synergistic delivery of dCas9 effectors is highly selective for the target site. Our findings further elucidate a causal role for reduced DNA methylation associated with escape from X chromosome inactivation. Understanding the epigenetics associated with escape from X chromosome inactivation has potential for those suffering from X-linked disorders
A Multinational Pharmacoeconomic Evaluation of Acute Major Depressive Disorder (MDD): a Comparison of Cost-Effectiveness Between Venlafaxine, SSRIs and TCAs
AbstractMethodsWe conducted a multinational pharmacoeconomic evaluation comparing the immediate release form of a new class of serotonin norepinephrine reuptake inhibitor (SNRI), venlafaxine IR to the selective serotonin reuptake inhibitors (SSRIs) and the tricyclic antidepressants (TCAs) in the treatment of acute major depressive disorder (MDD) in 10 countries (Germany, Italy, Netherlands, Poland, Spain, Sweden, Switzerland, United Kingdom, United States, and Venezuela). We designed a decision analytic model assessing the acute phase of MDD treatment within a 6-month time horizon. Six decision tree models were customized with country-specific estimates from a clinical management analysis, meta-analytic rates from two published meta-analyses, and a resource valuation of treatment costs representing the inpatient and outpatient settings within each country. The meta-analyses provided the clinical rates of success defined as a 50% reduction in depression scores on the Hamilton Depression Scale (HAM-D) or the Montgomery-Asberg Depression Rating Scale (MADRS). Treatment regimen costs were determined from standard lists, fee schedules, and communication with local health economists in each country. The meta-analytic rates were applied to the decision analytic model to calculate the expected cost and expected outcomes for each antidepressant comparator. Cost-effectiveness was determined using the expected values for both a successful outcome, and a composite measure of outcome termed symptom-free days. A policy analysis was conducted to examine the health system budget impact in each country of increasing the utilization of the most effective antidepressant found in our study.ResultsInitiating treatment of MDD with venlafaxine IR yielded a lower expected cost compared to the SSRIs and TCAs in all countries except Poland in the inpatient setting, and Italy and Poland within the outpatient settings. The weighted average expected cost per patient varied from US5647 (US) in the six-month acute phase treatment of MDD. The estimated total budgetary impact for each 1% of venlafaxine utilization, assuming a population of one million MDD patients, ranged from US29,049 (US).ConclusionsWithin the inpatient and outpatient treatment settings, venlafaxine IR was a more cost-effective treatment of MDD compared to the SSRIs and TCAs. Additionally, the results of this investigation indicate that increased utilization of venlafaxine in most settings across Europe and the Americas will have favorable impact on health care payer budgets.ADR, adverse drug reaction; CMA, clinical management analysis; ECT, electroconvulsive therapy; HAM-D, Hamilton Depression Scale; MADRS, Montgomery-Asberg depression rating scale; MDD, major depressive disorder; SFD, symptom-free day; SNRI, serotonin-norepinephrine reuptake inhibitor; SSRI, selective serotonin reuptake inhibitor; TCA, tricyclic antidepressant; WHO, world health organization
Evidence for mass renormalization in LaNiO$"" sub 3_: an in situ soft x-ray photoemission study of epitaxial films
We investigate the electronic structure of high-quality single-crystal
LaNiO (LNO) thin films using in situ photoemission spectroscopy (PES). The
in situ high-resolution soft x-ray PES measurements on epitaxial thin films
reveal the intrinsic electronic structure of LNO. We find a new sharp feature
in the PES spectra crossing the Fermi level, which is derived from the
correlated Ni 3 electrons. This feature shows significant enhancement
of spectral weight with decreasing temperature. From a detailed analysis of
resistivity data, the enhancement of spectral weight is attributed to
increasing electron correlations due to antiferromagnetic fluctuations.Comment: 4 pages, 4 figures. submitted to Phys. Rev.
Inertial domain wall characterization in layered multisublattice antiferromagnets
The motion of a Neel-like 180 degrees domain wall induced by a time-dependent staggered spin-orbit field in the layered collinear antiferromagnet Mn2Au is explored. Through an effective version of the two sublattice nonlinear a-model which does not take into account the antiferromagnetic exchange interaction directed along the tetragonal c-axis, it is possible to replicate accurately the relativistic and inertial traces intrinsic to the magnetic texture dynamics obtained through atomistic spin dynamics simulations for quasistatic processes. In the case in which the steady-state magnetic soliton motion is extinguished due to the abrupt shutdown of the external stimulus, its stored relativistic exchange energy is transformed into a complex translational mobility, being the rigid domain wall profile approximation no longer suitable. Although it is not feasible to carry out a detailed follow-up of its temporal evolution in this case, it is possible to predict the inertial-based distance travelled by the domain wall in relation to its steady-state relativistic mass. This exhaustive dynamical characterization for different time-dependent regimes of the driving force is of potential interest in antiferromagnetic domain wall-based device applications.R.R.-E., K.Y.G., and R.M.O. thanks O. Chubykalo-Fesenko, S. Khmelevskyi, A. A. Sapozhnik, M. Jourdan, A. K. Zvezdin, and B. A. Ivanov for the fruitful discussions that have helped us to improve this manuscript. The work of R.M.O. and K.Y.G. was partially supported by the STSM Grants from the COST Action CA17123 "Ultrafast opto-magneto-electronics for non-dissipative information technology''. K.Y.G. acknowledges support by IKERBASQUE (the Basque Foundation for Science) and the Spanish Ministry of Science and Innovation under grant PID2019-108075RB-C33/AEI/10.13039/501100011033
Effective magnetization damping for a dynamical spin texture in metallic ferromagnet
An additional magnetization damping for an inhomogeneous spin texture in metallic ferromagnets is calculated
on the basis of the s–d exchange model. The effect of conduction electrons on the magnetization dynamics is
accounted for the case of slowly varying spin texture within adiabatic approximation by using a coordinate transformation
to the local quantization axis. The moving magnetic vortex in a circular nanodot made of permalloy is
considered as an example. The dependence of the damping on the dot geometrical sizes is obtained. It is found
that the additional damping can reach up to 50% of magnitude of the phenomenological Gilbert damping in the
Landau–Lifshitz equation of magnetization motion and should be taken into account for any inhomogeneous
spin texture dynamics in ferromagnetic metals
Radial migration of the Sun in galactic disk
Physics of the gravitational effect of the galactic bar and spiral structure
is presented. Physical equations differ from the conventionally used equations.
Application to the motion of the Sun is treated. The speed of the Sun is
taken to be consistent with the Oort constants.
Galactic radial migration of the Sun is less than +- 0.4 kpc for the
four-armed spiral structure. The Sun remains about 75 % of its existence within
galactocentric distances (7.8 - 8.2) kpc and the results are practically
independent on the spiral structure strength. Thus, the radial distance changes
only within 5 % from the value of 8 kpc.
Galactic radial migration of the Sun is less than +- (0.3 - 1.2) kpc, for the
two-armed spiral structure. The Sun remains (29 - 95) % of its existence within
galactocentric distances (7.8 - 8.2) kpc and the results strongly depend on the
spiral structure strength and the angular speed of the spiral arms. The radial
distance changes within (3.8 - 15.0) % from the value of 8 kpc.
If observational arguments prefer relevant radial migration of the Sun, then
the Milky Way is characterized by the two-arm spiral structure.Comment: 9 page
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