Immunohistochemical evaluation of iron accumulation in term placenta of preeclamptic patients

Preeclampsia is a disease which involves hypertension and multisystem, it effects approximately 2 to 8% of all pregnancies and is a significant cause of maternal and newborn mortality and morbidity. It develops in the placenta and its pathogenesis is associated with placental abnormalities. Classical immunohistochemical studies on placenta have shown that there is a linear increase in iron storage in the placenta in the first half of a normal pregnancy, however, these stocks are decreased in normal 3rd trimester placenta. Iron accumulation in term placentas of preeclamptic and normal pregnancies were evaluated in this study. Ferritin immunostaining was observed to be more intense in preeclamptic group than in the control group, especially in Hofbauer cells, subtrophoblastic areas of stem villous, perivasculer stroma and villous stroma. Statistical analysis of the data was performed using SPSS software. Mann Whitney U test was used in the analysis and P values below 0.05 were statistically significant. In this study, iron accumulations in normotensif and preeclamptic placentas werecompared.Key words: Preeclampsia, placenta, immunohistochemistry, iron accumulation

Demixing in mesoscopic boson-fermion clouds inside cylindrical harmonic traps: quantum phase diagram and role of temperature

We use a semiclassical three-fluid thermodynamic model to evaluate the phenomena of spatial demixing in mesoscopic clouds of fermionic and bosonic atoms at high dilution under harmonic confinement, assuming repulsive boson-boson and boson-fermion interactions and including account of a bosonic thermal cloud at finite temperature T. The finite system size allows three different regimes for the equilibrium density profiles at T=0: a fully mixed state, a partially mixed state in which the overlap between the boson and fermion clouds is decreasing, and a fully demixed state where the two clouds have zero overlap. We propose simple analytical rules for the two cross-overs between the three regimes as functions of the physical system parameters and support these rules by extensive numerical calculations. A universal ``phase diagram'' expressed in terms of simple scaling parameters is shown to be valid for the transition to the regime of full demixing, inside which we identify several exotic configurations for the two phase-separated clouds in addition to simple ones consisting of a core of bosons enveloped by fermions and "vice versa". With increasing temperature the main role of the growing thermal cloud of bosons is to transform some exotic configurations into more symmetric ones, until demixing is ultimately lost. For very high values of boson-fermion repulsive coupling we also report demixing between the fermions and the thermally excited bosons.Comment: 11 pages, 8 figure

Collective excitations of a trapped boson-fermion mixture across demixing

We calculate the spectrum of low-lying collective excitations in a mesoscopic cloud formed by a Bose-Einstein condensate and a spin-polarized Fermi gas as a function of the boson-fermion repulsions. The cloud is under isotropic harmonic confinement and its dynamics is treated in the collisional regime by using the equations of generalized hydrodynamics with inclusion of surface effects. For large numbers of bosons we find that, as the cloud moves towards spatial separation (demixing) with increasing boson-fermion coupling, the frequencies of a set of collective modes show a softening followed by a sharp upturn. This behavior permits a clear identification of the quantum phase transition. We propose a physical interpretation for the dynamical transition point in a confined mixture, leading to a simple analytical expression for its location.Comment: revtex4, 9 pages, 8 postscript file

Back Reaction of Strings in Self-Consistent String Cosmology

We compute the string energy-momentum tensor and {\bf derive} the string equation of state from exact string dynamics in cosmological spacetimes. $1+1,~2+1$ and $D$-dimensional universes are treated for any expansion factor $R$. Strings obey the perfect fluid relation $p = (\gamma -1) \rho$ with three different behaviours: (i) {\it Unstable} for $R \to \infty$ with growing energy density $\rho \sim R^{2-D}$, {\bf negative} pressure, and $\gamma =(D-2)/(D-1)$; (ii){\it Dual} for $R \to 0$, with $\rho \sim R^{-D}$, {\bf positive} pressure and $\gamma = D/(D-1)$ (as radiation); (iii) {\it Stable} for $R \to \infty$ with $\rho \sim R^{1-D}$, {\bf vanishing} pressure and $\gamma = 1$ (as cold matter). We find the back reaction effect of these strings on the spacetime and we take into account the quantum string decay through string splitting. This is achieved by considering {\bf self-consistently} the strings as matter sources for the Einstein equations, as well as for the complete effective string equations. String splitting exponentially suppress the density of unstable strings for large $R$. The self-consistent solution to the Einstein equations for string dominated universes exhibits the realistic matter dominated behaviour $R \sim (X^0)^{2/(D-1)}\;$ for large times and the radiation dominated behaviour $R \sim (X^0)^{2/D}\;$ for early times. De Sitter universe does not emerge as solution of the effective string equations. The effective string action (whatever be the dilaton, its potential and the central charge term) is not the appropriate framework in which to address the question of string driven inflation.Comment: 29 pages, revtex, LPTHE-94-2

Friedel oscillations in a gas of interacting one-dimensional fermionic atoms confined in a harmonic trap

Using an asymptotic phase representation of the particle density operator $\hat{\rho}(z)$ in the one-dimensional harmonic trap, the part $\delta \hat{\rho}_F(z)$ which describes the Friedel oscillations is extracted. The expectation value $$ with respect to the interacting ground state requires the calculation of the mean square average of a properly defined phase operator. This calculation is performed analytically for the Tomonaga-Luttinger model with harmonic confinement. It is found that the envelope of the Friedel oscillations at zero temperature decays with the boundary exponent $\nu = (K+1)/2$ away from the classical boundaries. This value differs from that known for open boundary conditions or strong pinning impurities. The soft boundary in the present case thus modifies the decay of Friedel oscillations. The case of two components is also discussed.Comment: Revised version to appear in Journal of Physics B: Atomic, Molecular and Optical Physic

The effectiveness of two silicone dressings for sacral and heel pressure ulcer prevention compared with no dressings in high‐risk intensive care unit patients: a randomized controlled parallel‐group trial

Background There is a high incidence of pressure ulcers in high-risk settings such as intensive care. There is emerging evidence that the application of dressings to pressure ulcer predilection areas (sacrum and heels) improves prevention strategies. Objectives To determine whether preventive dressings, applied to the sacrum and heels of high-risk patients in intensive care units, in addition to standard prevention, reduces the incidence of pressure ulcers. Methods Between June 2015 and July 2018, a randomized, controlled, two-arm, superiority pragmatic study was performed with a concealed 1 : 1 allocation to the intervention and control group. Patients assigned to the intervention group had dressings applied to the sacrum and heels. Results In total, 7575 patients were screened for eligibility and 475 patients were included and allocated to both groups. Finally, 212 patients in the intervention group and 210 in the control group were analysed. The mean age was 63 center dot 5 years and the majority of patients were male (65 center dot 4%). The cumulative pressure ulcer incidence category II and above was 2 center dot 8% in the intervention, and 10 center dot 5% in the control group (P = 0 center dot 001). Compared with the control group, the relative risk in the intervention group was 0 center dot 26 [95% confidence interval (CI) 0 center dot 11-0 center dot 62] and the absolute risk reduction was 0 center dot 08 (95% CI 0 center dot 03-0 center dot 13). Conclusions The results indicate that the application of dressings, in addition to standard prevention, in high-risk intensive care unit patients is effective in preventing pressure ulcers at the heels and sacrum. What's already known about this topic? Pressure ulcers are severe soft tissue injuries and wounds, which occur worldwide in all healthcare settings. Despite preventive interventions, pressure ulcers still develop. There is emerging evidence that dressings help to prevent pressure ulcers. What does this study add? The incidence of pressure ulcers in intensive care units among high-risk patients remains high. The application of dressings to the sacrum and heels, in addition to standard preventive measures, reduces the relative and absolute risks for the development of pressure ulcers. The application of preventive dressings at the heels and sacrum seems to be feasible in intensive care settings

Collective ferromagnetism in two-component Fermi-degenerate gas trapped in finite potential

Spin asymmetry of the ground states is studied for the trapped spin-degenerate (two-component) gases of the fermionic atoms with the repulsive interaction between different components, and, for large particle number, the asymmetric (collective ferromagnetic) states are shown to be stable because it can be energetically favorable to increase the fermi energy of one component rather than the increase of the interaction energy between up-down components. We formulate the Thomas-Fermi equations and show the algebraic methods to solve them. From the Thomas-Fermi solutions, we find three kinds of ground states in finite system: 1) paramagnetic (spin-symmetric), 2) ferromagnetic (equilibrium) and 3) ferromagnetic (nonequilibrium) states. We show the density profiles and the critical atom numbers for these states obtained analytically, and, in ferromagnetic states, the spin-asymmetries are shown to occur in the central regions of the trapped gas, and grows up with increasing particle number. Based on the obtained results, we discuss the experimental conditions and current difficulties to realize the ferromagnetic states of the trapped atom gas, which should be overcome.Comment: submit to PR

Harmonically trapped fermion gases: exact and asymptotic results in arbitrary dimensions

We investigate the particle and kinetic energy densities of harmonically trapped fermion gases at zero temperature in arbitrary dimensions. We derive analytically a differential equation connecting these densities, which so far have been proven only in one or two dimensions, and give other interesting relations involving several densities or the particle density alone. We show that in the asymptotic limit of large particle numbers, the densities go over into the semi-classical Thomas-Fermi (TF) densities. Hereby the Fermi energy to be used in the TF densities is identified uniquely. We derive an analytical expansion for the remaining oscillating parts and obtain very simple closed forms for the leading-order oscillating densities. Finally, we show that the simple TF functional relation $\tau_{TF}[\rho]$ between kinetic and particle density is fulfilled also for the asymptotic quantum densities $\tau(r)$ and $\rho(r)$ including their leading-order oscillating terms.Comment: LaTeX, 22 pages with 6 figures (*.eps), to be submitted to J. Phys.

Circular String-Instabilities in Curved Spacetime

We investigate the connection between curved spacetime and the emergence of string-instabilities, following the approach developed by Loust\'{o} and S\'{a}nchez for de Sitter and black hole spacetimes. We analyse the linearised equations determining the comoving physical (transverse) perturbations on circular strings embedded in Schwarzschild, Reissner-Nordstr\"{o}m and de Sitter backgrounds. In all 3 cases we find that the "radial" perturbations grow infinitely for $r\rightarrow 0$ (ring-collapse), while the "angular" perturbations are bounded in this limit. For $r\rightarrow\infty$ we find that the perturbations in both physical directions (perpendicular to the string world-sheet in 4 dimensions) blow up in the case of de Sitter space. This confirms results recently obtained by Loust\'{o} and S\'{a}nchez who considered perturbations around the string center of mass.Comment: 24 pages Latex + 2 figures (not included). Observatoire de Paris, Meudon No. 9305

Two-dimensional gravitation and Sine-Gordon-Solitons

Some aspects of two-dimensional gravity coupled to matter fields, especially to the Sine-Gordon-model are examined. General properties and boundary conditions of possible soliton-solutions are considered. Analytic soliton-solutions are discovered and the structure of the induced space-time geometry is discussed. These solutions have interesting features and may serve as a starting point for further investigations.Comment: 23 pages, latex, references added, to appear in Phys.Rev.