Cu-Doped KCl Unfolded Band Structure and Optical Properties Studied by DFT Calculations.

The unfolded band structure and optical properties of Cu-doped KCl crystals were computed by first principles within the framework of density functional theory, implemented in the ABINIT software program, utilizing pseudopotential approximation and a plane-wave basis set. From a theoretical point of view, Cu substitution into pristine KCl crystals requires calculation by the supercell (SC) method. This procedure shrinks the Brillouin zone, resulting in a folded band structure that is difficult to interpret. To solve this problem and gain insight into the effect of copper ions (Cu+) on electronic properties, the band structure of SC KCl:Cu was unfolded to make a direct comparison with the band structure of the primitive cell (PC) of pristine KCl. To understand the effect of Cu substitution on optical absorption, we calculated the imaginary part of the dielectric function of KCl:Cu through a sum-over-states formalism and broke it down into different band contributions by partially making an iterated cumulative sum (ICS) of selected valence and conduction bands. Consequently, we identified those interband transitions that give rise to the absorption peaks due to the Cu+ ion. These transitions involve valence and conduction bands formed by the Cu-3d and Cu-4s electronic states.

Luminescent Properties of Eu3+-Doped Hybrid SiO2-PMMA Material for Photonic Applications.

Hybrid organic-inorganic materials are of great interest for various applications. Here, we report on the synthesis and optical characterization of silica-PMMA samples with different Eu3+ molar concentrations. The optical properties of this material make it suitable for photonic applications. The samples were prepared using the sol-gel method, mixing tetraethyl orthosilicate (TEOS) as a silica glass precursor and methyl methacrylate (PMMA) as a polymer component. Europium nitrate pentahydrate was then added in six different molar concentrations (0.0, 0.1, 0.25, 0.5, 0.75, and 1%) to obtain as many different samples of the material. The absorption spectra were obtained applying the Kubelka⁻Munk formula to the diffuse reflectance spectra of the samples, all in the wavelength range between 240 and 2500 nm. The emission and excitation measurements were made in the visible range. Five bands could be identified in the emission spectra, related to electronic transitions of the ion Eu3+ (4D0→7Fi, i from 0 to 4). In the excitation spectra, the following bands were detected: 7F0→5G3 (379 nm), 7F0→5G2 (380 nm), 7F0→5L6 (392 nm), 7F0→5D3 (407 nm), 7F0→5D2 (462 nm), and 7F0→5D1 (530 nm). The emission decay times were measured for the different samples and showed an inverse dependence with the Eu3+ concentration.

Deficiencia de proteínas de superficie ancladas por glucosilfosfatidilinositol en células de pacientes mestizos mexicanos con hipoplasia medular / Clycosilphosphatidylinositol anchored cell surface proteins deficiency in mexican mestizo patients with aplastic anemia

Se estudiaron de manera prospectiva 10 sujetos con diagnóstico histológico de hipoplasia medular para identificar por medio de citometría de flujo las características de las moléculas de superficie CD55 y CD59, ancladas a la superficie celular a través de glucosilfosfatidilinositol (GPI). En cinco se identificó una distribución anormal de estas moléculas; las pruebas de hemólisis ácida, por insulina y sacarosa, así como la investigación de hemosiderinuria fueron anormales en dos de los cinco pacientes. Cinco de ellos fueron tratados con globulina antitimocito y ciclosporina-A y tres se encuentran en remisión completa, en tanto que cinco enfermos fueron tratados con andrógenos y ninguno logró la remisión. De los pacientes en remisión completa, uno tuvo trastornos en las moléculas ancladas por GPI ocurren con frecuencia en pacientes con hipoplasia medular, que la identificación de estas alteraciones es más sensible que las pruebas tradicionales para investigar hemoglobinuria paroxística nocturna (HPN), que las formas aplásticas de HPN son frecuentes en nuestro país y que el tratamiento con inmunosupresión intensa puede ser efectivos en algunas formas hipoplásicas de la HPN. La identificación citofluorográfica de las alteraciones en las moléculas ancladas por GPI debieran reemplazar a las pruebas ®tradicionales¼ para identificar a la HPN