86 research outputs found
Boson stars and oscillatons in an inflationary universe
Spherically symmetric gravitationally bound, oscillating scalar lumps (boson
stars and oscillatons) are considered in Einstein's gravity coupled to massive
scalar fields in 1+D dimensional de Sitter-type inflationary space-times. We
show that due to inflation bosons stars and oscillatons lose mass through
scalar radiation, but at a rate that is exponentially small when the expansion
rate is slow.Comment: 19 pages, 5 figure
Mass loss and longevity of gravitationally bound oscillating scalar lumps (oscillatons) in D-dimensions
Spherically symmetric oscillatons (also referred to as oscillating soliton
stars) i.e. gravitationally bound oscillating scalar lumps are considered in
theories containing a massive self-interacting real scalar field coupled to
Einstein's gravity in 1+D dimensional spacetimes. Oscillations are known to
decay by emitting scalar radiation with a characteristic time scale which is,
however, extremely long, it can be comparable even to the lifetime of our
universe. In the limit when the central density (or amplitude) of the
oscillaton tends to zero (small-amplitude limit) a method is introduced to
compute the transcendentally small amplitude of the outgoing waves. The results
are illustrated in detail on the simplest case, a single massive free scalar
field coupled to gravity.Comment: 23 pages, 2 figures, references on oscillons added, version to appear
in Phys. Rev.
Computation of the radiation amplitude of oscillons
The radiation loss of small amplitude oscillons (very long-living, spatially
localized, time dependent solutions) in one dimensional scalar field theories
is computed in the small-amplitude expansion analytically using matched
asymptotic series expansions and Borel summation. The amplitude of the
radiation is beyond all orders in perturbation theory and the method used has
been developed by Segur and Kruskal in Phys. Rev. Lett. 58, 747 (1987). Our
results are in good agreement with those of long time numerical simulations of
oscillons.Comment: 22 pages, 9 figure
Persistence with statin therapy in Hungary
Introduction: Persistence with lipid-lowering drug therapy by cardiovascular patients in Hungary has not been studied previously. This study was designed to determine the rate with which Hungarian patients with hyperlipidemia persist in taking lipid-lowering agents, and to compare this with rates reported from other countries.
Material and methods: This was a retrospective study that utilized data from the Institutional Database of the National Health Insurance Fund to analyze persistence rates with statins and ezetimibe. The study included data for patients who started lipid-lowering therapy between January 1, 2007, and March 31, 2009. Variables included type of lipid-lowering therapy, year of therapy start, and patient age. Main outcome measures were medians of persistence in months, percentages of patients persisting in therapy for 6 and 12 months, and Kaplan-Meier persistence plots.
Results: The percentage of patients who persisted with overall statin therapy was 46% after 1 month, 40.3% after 2 months, 27% after 6 months, and 20.1% after 12 months. Persistence was slightly greater for statin therapy started during 2008 than during 2007. Older patients were more persistent with therapy than younger patients. Persistence with the combination of ezetimibe-statin therapy was greater than with statin or ezetimibe monotherapy.
Conclusions: Persistence with statin therapy by patients in Hungary was low compared with other countries. Low persistence may have negated potential clinical benefits of long-term statin therapy
Fractal-based analysis of optical coherence tomography data to quantify retinal tissue damage
BACKGROUND: The sensitivity of Optical Coherence Tomography (OCT) images to identify retinal tissue morphology characterized by early neural loss from normal healthy eyes is tested by calculating structural information and fractal dimension. OCT data from 74 healthy eyes and 43 eyes with type 1 diabetes mellitus with mild diabetic retinopathy (MDR) on biomicroscopy was analyzed using a custom-built algorithm (OCTRIMA) to measure locally the intraretinal layer thickness. A power spectrum method was used to calculate the fractal dimension in intraretinal regions of interest identified in the images. ANOVA followed by Newman-Keuls post-hoc analyses were used to test for differences between pathological and normal groups. A modified p value of <0.001 was considered statistically significant. Receiver operating characteristic (ROC) curves were constructed to describe the ability of each parameter to discriminate between eyes of pathological patients and normal healthy eyes. RESULTS: Fractal dimension was higher for all the layers (except the GCL + IPL and INL) in MDR eyes compared to normal healthy eyes. When comparing MDR with normal healthy eyes, the highest AUROC values estimated for the fractal dimension were observed for GCL + IPL and INL. The maximum discrimination value for fractal dimension of 0.96 (standard error =0.025) for the GCL + IPL complex was obtained at a FD <= 1.66 (cut off point, asymptotic 95% Confidence Interval: lower-upper bound = 0.905-1.002). Moreover, the highest AUROC values estimated for the thickness measurements were observed for the OPL, GCL + IPL and OS. Particularly, when comparing MDR eyes with control healthy eyes, we found that the fractal dimension of the GCL + IPL complex was significantly better at diagnosing early DR, compared to the standard thickness measurement. CONCLUSIONS: Our results suggest that the GCL + IPL complex, OPL and OS are more susceptible to initial damage when comparing MDR with control healthy eyes. Fractal analysis provided a better sensitivity, offering a potential diagnostic predictor for detecting early neurodegeneration in the retina
Cellular immune response in Dupuytren\u27s disease
Uvod: Patogeneza Dupuytrenove bolesti je nejasna, no mogu se pretpostaviti upalni mehanizmi u njenoj pozadini.
Materijali i metode: Mjerili smo udjele različitih podvrsta monocita i lim-focita u perifernoj krvi prema stadiju bolesti kod 39 bolesnika oboljelih od Dupuytrenove bolesti. Rezultate smo usporedili s rezultatima 29 zdravih kontrolnih ispitanika iz iste dobne skupine. Mjerenja su napravljena pomoću protočne citometrije.
Rezultati: U aktivnom su stadiju bolesnici imali bitno povišen udio monocita, NK-stanica sličnih T-limfocitima, dok je udio B-limfocita bio značajno snižen, uključujući CD5+ B-limfocite. Udjeli CD4+, CD8+ T-limfocita i B-limfocita nisu se znatno promijenili. U naprednom su stadiju bolesti udjeli monocita i B-limfocita ostali konstantnima, no značajno su se snizili udjeli T-limfocita. U četiri slučaja među bolesnicima koji boluju od Dupuytrenove bolesti pojavile su se limfoidne neoplazme zrelih B- ili T-limfocita.
Zaključci: Naši rezultati podupiru prijašnja mišljenja da su limfociti povezani s patogenezom Dupuytrenove bolesti te pojačavaju ulogu monocita, NK-stanica sličnih T-limfocitima i promjenu imunosnog odgovora između stadija bolesti.Background: The pathogenesis of Dupuytren\u27s disease is unclear, but inflammatory mechanisms might be supposed in the background.
Materials and methods: The ratios of the subsets of monocytes and lymphocytes in the peripheral blood were measured according to the stage of the disease of 39 Dupuytren\u27s patients. They were compared with those of 29 healthy, age-matched controls. The measurements were accomplished by flow-cytometry.
Results: In an active stage, the patients had significantly increased ratios of monocytes, NK-like T-cells, whereas significantly decreased ratio of B-lymphocytes, including CD5+ B-cells. The ratios of CD4+, CD8+ T-cells and NK-cells did not change significantly. In the advanced stage, the ratios of monocytes and B-lymphocytes remained constant, but the ratios of T-cells decreased significantly. In four cases among Dupuytren\u27s patients, mature B- or T-cell lymphoid malignancies occurred.
Conclusions: Our results support the previous considerations that lymphocytes are involved in the pathogenesis of Dupuytren\u27s disease and enhance the role of monocytes, NK-like T-cells and the alteration of immune response between the stages of the disease
Cellular immune response in Dupuytren\u27s disease
Uvod: Patogeneza Dupuytrenove bolesti je nejasna, no mogu se pretpostaviti upalni mehanizmi u njenoj pozadini.
Materijali i metode: Mjerili smo udjele različitih podvrsta monocita i lim-focita u perifernoj krvi prema stadiju bolesti kod 39 bolesnika oboljelih od Dupuytrenove bolesti. Rezultate smo usporedili s rezultatima 29 zdravih kontrolnih ispitanika iz iste dobne skupine. Mjerenja su napravljena pomoću protočne citometrije.
Rezultati: U aktivnom su stadiju bolesnici imali bitno povišen udio monocita, NK-stanica sličnih T-limfocitima, dok je udio B-limfocita bio značajno snižen, uključujući CD5+ B-limfocite. Udjeli CD4+, CD8+ T-limfocita i B-limfocita nisu se znatno promijenili. U naprednom su stadiju bolesti udjeli monocita i B-limfocita ostali konstantnima, no značajno su se snizili udjeli T-limfocita. U četiri slučaja među bolesnicima koji boluju od Dupuytrenove bolesti pojavile su se limfoidne neoplazme zrelih B- ili T-limfocita.
Zaključci: Naši rezultati podupiru prijašnja mišljenja da su limfociti povezani s patogenezom Dupuytrenove bolesti te pojačavaju ulogu monocita, NK-stanica sličnih T-limfocitima i promjenu imunosnog odgovora između stadija bolesti.Background: The pathogenesis of Dupuytren\u27s disease is unclear, but inflammatory mechanisms might be supposed in the background.
Materials and methods: The ratios of the subsets of monocytes and lymphocytes in the peripheral blood were measured according to the stage of the disease of 39 Dupuytren\u27s patients. They were compared with those of 29 healthy, age-matched controls. The measurements were accomplished by flow-cytometry.
Results: In an active stage, the patients had significantly increased ratios of monocytes, NK-like T-cells, whereas significantly decreased ratio of B-lymphocytes, including CD5+ B-cells. The ratios of CD4+, CD8+ T-cells and NK-cells did not change significantly. In the advanced stage, the ratios of monocytes and B-lymphocytes remained constant, but the ratios of T-cells decreased significantly. In four cases among Dupuytren\u27s patients, mature B- or T-cell lymphoid malignancies occurred.
Conclusions: Our results support the previous considerations that lymphocytes are involved in the pathogenesis of Dupuytren\u27s disease and enhance the role of monocytes, NK-like T-cells and the alteration of immune response between the stages of the disease
Semi-local quantum liquids
Gauge/gravity duality applied to strongly interacting systems at finite
density predicts a universal intermediate energy phase to which we refer as a
semi-local quantum liquid. Such a phase is characterized by a finite spatial
correlation length, but an infinite correlation time and associated nontrivial
scaling behavior in the time direction, as well as a nonzero entropy density.
For a holographic system at a nonzero chemical potential, this unstable phase
sets in at an energy scale of order of the chemical potential, and orders at
lower energies into other phases; examples include superconductors and
antiferromagnetic-type states. In this paper we give examples in which it also
orders into Fermi liquids of "heavy" fermions. While the precise nature of the
lower energy state depends on the specific dynamics of the individual system,
we argue that the semi-local quantum liquid emerges universally at intermediate
energies through deconfinement (or equivalently fractionalization). We also
discuss the possible relevance of such a semi-local quantum liquid to heavy
electron systems and the strange metal phase of high temperature cuprate
superconductors.Comment: 31 pages, 7 figure
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