Prevalence and severity of hepatopulmonary syndrome and its influence on survival in cirrhotic patients evaluated for liver transplantation.

The prevalence of hepatopulmonary syndrome (HPS) and its influence on survival before and after liver transplantation (LT) remain controversial. Additionally, the chronology of post-LT reversibility is unclear. This study prospectively analyzed 316 patients with cirrhosis who were evaluated for LT in 2002-2007; 177 underwent LT at a single reference hospital. HPS was defined by a partial pressure of arterial oxygen (PaO2 ) <70 mmHg and/or an alveolar-arterial oxygen gradient (A-a PO2 ) ≥20 mmHg in the supine position and positive contrast echocardiography. The prevalence of HPS was 25.6% (81/316 patients), and most patients (92.6%) had mild or moderate HPS. High Child-Pugh scores and the presence of ascites were independently associated with HPS. Patients with and without HPS did not significantly differ in LT waiting list survival (mean 34.6 months vs. 41.6 months, respectively; log-rank, p = 0.13) or post-LT survival (mean 45 months vs. 47.6 months, respectively; log-rank, p = 0.62). HPS was reversed in all cases within 1 year after LT. One-fourth of the patients with cirrhosis who were evaluated for LT had HPS (mostly mild to moderate); the presence of HPS did not affect LT waiting list survival. HPS was always reversed after LT, and patient prognosis did not worsen.

Local coordination of Fe(3+) in layered LiCo(1-y)Al(y)O(2) oxides determined by high-frequency electron paramagnetic resonance spectroscopy.

The local coordination of Fe(3+) spin probes in trigonal LiAl(y)Co(1-y)O(2) was studied using high-frequency electron paramagnetic resonance spectroscopy. This technique allows the determination of Fe(3+) ions in respect to axial and rhombic zero-field splitting parameters (ZFS). After the progressive replacement of Co by Al, the axial D parameter of Fe(3+) increases from +0.0548 to +0.2802 cm(-1). On the same order, the rhombic E parameter decreases. Structural information about the Fe(3+) site in layered LiAl(y)Co(1-y)O(2) oxides was based on modeling of the magnitude of the ZFS parameters by means of the Newman superposition model. It was found that the first metal coordination sphere including Co(3+) and Al(3+) ions gave rise to differentiation of the Fe(3+) dopants in respect to local trigonal and rhombic distortion. The maximum trigonal distortion for the FeO(6) octahedron was achieved when Fe(3+) spin probes were surrounded by Al only, while the Co environment yields a rhombic distortion of the FeO(6) octahedron.

A counterfactual impact evaluation of a bilingual program on students' grade point average at a spanish university.

This observational study intends to estimate the causal effects of an English as a Medium of Instruction (EMI) program (as predictor) on students Grade Point Average (GPA) (as outcome) at a particular University in Spain by using a Counterfactual Impact Evaluation (CIE). The need to address the crucial question of causal inferences in EMI programs to produce credible evidences of successful interventions contrasts, however, with the absence of experimental or quasi-experimental research and evaluation designs in the field. CIE approach is emerging as a methodologically viable solution to bridge that gap. The program evaluated here consisted in delivering an EMI program in a Primary Education Teacher Training Degree group. After achieving balance on the observed covariates and recreating a situation that would have been expected in a randomized experiment, three matching approaches such as genetic matching, nearest neighbor matching and Coarsened Exact Matching were used to analyze observational data from a total of 1288 undergraduate students, including both treatment and control group. Results show unfavorable effects of the bilingual group treatment condition. Potential interpretations and recommendations are provided in order to strengthen future causal evidences of bilingual education programs' effectiveness in Higher Education.

X-ray Diffraction and (119)Sn Mössbauer Spectroscopy Study of a New Phase in the Bi(2)Se(3)-SnSe System: SnBi(4)Se(7).

First studies of the ternary system SnSe-Bi(2)Se(3) developed in 1960s and 1970s have revealed the existence of a nonstoichiometric trigonal phase with a wide range of compositions. In this study, an almost stoichiometric phase, corresponding to the composition SnBi(4)Se(7), has been identified and isolated. The structure has been determined by X-ray diffraction and the local environment of Sn atoms analyzed by Mössbauer spectroscopy. This phase has a rhombohedral structure, space group R&thremacr;m, with hexagonal lattice parameters a = 4.1602(5) Å and c = 38.934(3) Å. The unit cell contains three slabs, each one composed of seven atomic layers according to the sequence Se-Bi-Se-(Bi,Sn)-Se-Bi-Se. Bismuth atoms partially occupy two sites, 3a (0, 0, 0) and 6c (0, 0, z) with z = 0.4285, while tin atoms partially occupy only one site, 3a. Selenium atoms are placed in two different 6c sites, with z(1) = 0.1350 and z(2) = 0.7108.