Challenges and strategies: treating spontaneous pneumothorax in massive pulmonary langerhans cell histiocytosis in children.

Objective: The objective of this study was to report two cases of successive multiple spontaneous bilateral pneumothorax in children with massive lung involvement due to Langerhans cell histiocytosis (LCH), emphasizing the possibility of this differential diagnosis for the general pediatrician. Additionally, published cases describing pediatric patients with pulmonary manifestations of LCH were reviewed in the literature.

Case Description: Case #1: A 3-year-old male patient with a sudden episode of spontaneous right-sided pneumothorax, surgically drained.

The structural inhomogeneity of lead-cadmium fluoride systems and its implications.

In this paper we present a detailed study of structural and dynamical properties of the CdF(2)-PbF(2) systems. Particular attention is devoted to the processes involving the phase separation, a phenomenon of fundamental importance in the correct description of some dynamical properties, as introduced in our previous works. We show here, that the phase separation trend is observed in the undercooled melt, whether by cooling the liquid below its melting point, or by heating a homogeneous glass at temperatures above T(g).

Local order around rare earth ions during the devitrification of oxyfluoride glasses.

Erbium L(3)-edge extended x-ray absorption fine structure (EXAFS) measurements were performed on rare earth doped fluorosilicate and fluoroborate glasses and glass ceramics. The well known nucleating effects of erbium ions for the crystallization of cubic lead fluoride (based on x-ray diffraction measurements) and the fact that the rare earth ions are present in the crystalline phase (as indicated by Er(3+) emission spectra) seem in contradiction with the present EXAFS analysis, which indicates a lack of medium range structural ordering around the Er(3+) ions and suggests that the lead fluoride crystallization does not occur in the nearest neighbor distance of the rare earth ion. Molecular dynamics simulations of the devitrification process of a lead fluoride glass doped with Er(3+) ions were performed, and results indicate that Er(3+) ions lower the devitrification temperature of PbF(2), in good agreement with the experimental results.

Structural ordering in Cd(x)Pb(1-x)F2 alloys: a combined molecular dynamics and solid state NMR study.

Molecular dynamics (MD) simulations of binary Cd(x)Pb(1-x)F(2) alloys have been carried out, using a two-body Buckingham interaction potential, leading to a correct description of structural properties as a function of composition and pointing towards an understanding of the eutectic phenomenon. The simulation data can be analyzed in terms of five local fluorine environments Q((n)) (4> or =n> or =0), where n is the number of Pb nearest-neighbor environments. The results suggest a highly nonstatistical population distribution, suggesting an intrinsic phase segregation tendency in the undercooled melt, during the cooling process.

Molecular dynamics simulations on the local order of liquid and amorphous ZnTe.

Molecular dynamics studies of structural and dynamical correlations of molten and vitreous states under several conditions of density and temperature were performed. We use an effective recently proposed interatomic potential, consisting of two- and three-body covalent interactions which has successfully described the structural, dynamical, and structural phase transformation induced by pressure in ZnTe [D. S.

New insight on the structural trends of polyphosphate coacervation processes.

In this study new compositions of polyphosphate coacervates were obtained with the ions Ni (2+) and Co (2+). Samples of the glassy systems were prepared with proportions P/M (+2) varying between 0.5 and 10.

Molecular dynamics simulation study of erbium induced devitrification in vitreous PbF2.

Molecular dynamics simulations of the devitrification process of a lead fluoride glass doped with Er(3+) ions were carried out. This technique appears to be a relevant way to perform systematic analysis of the system structure and to study the influence of defects on PbF2 crystallization. We modeled the total enthalpy, the radial distribution functions, and the diffracted intensities of systems containing different amounts of Er(3+) ions.

Molecular dynamics simulation on devitrification: isothermal devitrification and thermodynamics of PbF2 glasses.

The vitrification and devitrification features of lead fluoride are investigated by means of molecular dynamic simulations. The influence of heating rate on the devitrification temperature as well as the dependence of the glass properties on its thermal history, i.e.