67 research outputs found
Bakhtiari, Leskinen and Torma Reply
This is a Reply to: Comment on "Spectral Signatures of the
Fulde-Ferrell-Larkin-Ovchinnikov Order Parameter in One-Dimensional Optical
Lattices" R. A. Molina J. Dukelksy, and P. Schmitteckert, Phys. Rev. Lett. 102,
168901 (2009)Comment: 1 page, published versio
Pomeranchuk effect and spin-gradient cooling of Bose-Bose mixtures in an optical lattice
We theoretically investigate finite-temperature thermodynamics and
demagnetization cooling of two-component Bose-Bose mixtures in a cubic optical
lattice, by using bosonic dynamical mean field theory (BDMFT). We calculate the
finite-temperature phase diagram, and remarkably find that the system can be
heated from the superfluid into the Mott insulator at low temperature,
analogous to the Pomeranchuk effect in 3He. This provides a promising many-body
cooling technique. We examine the entropy distribution in the trapped system
and discuss its dependence on temperature and an applied magnetic field
gradient. Our numerical simulations quantitatively validate the spin-gradient
demagnetization cooling scheme proposed in recent experiments.Comment: 9 pages, 8 figure
Dynamical arrest of ultracold lattice fermions
We theoretically investigate the thermodynamics of an interacting
inhomogeneous two-component Fermi gas in an optical lattice. Motivated by a
recent experiment by L. Hackerm\"uller et al., Science, 327, 1621 (2010), we
study the effect of the interplay between thermodynamics and strong
correlations on the size of the fermionic cloud. We use dynamical mean-field
theory to compute the cloud size, which in the experiment shows an anomalous
expansion behavior upon increasing attractive interaction. We confirm this
qualitative effect but, assuming adiabaticity, we find quantitative agreement
only for weak interactions. For strong interactions we observe significant
non-equilibrium effects which we attribute to a dynamical arrest of the
particles due to increasing correlations.Comment: 4.5 pages, 5 figures (slightly different from published version
Spectral signatures of the Fulde-Ferrell-Larkin-Ovchinnikov order parameter in one-dimensional optical lattices
We address an imbalanced two-component atomic Fermi gas restricted by a
one-dimensional (1D) optical lattice and an external harmonic potential, within
the mean-field Bogoliubov-de Gennes (BdG) formalism. We show that
characteristic features of the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state
are visible in the RF-spectra and in the momentum resolved photoemission
spectra of the gas. Specially, Andreev states or mid-gap states can be clearly
resolved, which gives a direct experimentally observable signature of the
oscillating order parameter.Comment: published versio
Global, regional, and national burden of chronic kidney disease, 1990–2017 : a systematic analysis for the Global Burden of Disease Study 2017
Background
Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout.
Methods
The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function.
Findings
Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, −1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, −1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function.
Interpretation
Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI
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