Identification of hidden orbital contributions in the La_{0.65} Sr_{0.35} MnO_{3} valence band

Hybridization of electronic states and orbital symmetry in transition metal oxides are generally considered key ingredients in the description of both their electronic and magnetic properties. In the prototypical case of La_{0.65} Sr_{0.35} MnO_{3} (LSMO), a landmark system for spintronics applications, a description based solely on Mn 3d and O 2p electronic states is reductive. We thus analyzed elemental and orbital distributions in the LSMO valence band through a comparison between density functional theory calculations and experimental photoelectron spectra in a photon energy range from soft to hard x rays. We reveal a number of hidden contributions, arising specifically from La 5p, Mn 4s, O 2s orbitals, considered negligible in previous analyses; our results demonstrate that all these contributions are significant for a correct description of the valence band of LSMO and of transition metal oxides in general

Distinct behavior of localized and delocalized carriers in anatase TiO2 (001) during reaction with O-2

Two-dimensional (2D) metallic states induced by oxygen vacancies ( V O s ) at oxide surfaces and interfaces provide opportunities for the development of advanced applications, but the ability to control the behavior of these states is still limited. We used angle resolved photoelectron spectroscopy combined with density-functional theory (DFT) to study the reactivity of V O -induced states at the (001) surface of anatase TiO 2 , where both 2D metallic and deeper lying in-gap states (IGs) are observed. The 2D and IG states exhibit remarkably different evolutions when the surface is exposed to molecular O 2 : while IGs are almost completely quenched, the metallic states are only weakly affected. DFT calculations indeed show that the IGs originate from surface V O s and remain localized at the surface, where they can promptly react with O 2 . In contrast, the metallic states originate from subsurface vacancies whose migration to the surface for recombination with O 2 is kinetically hindered on anatase TiO 2 (001), thus making them much less sensitive to oxygen dosing

Risk factors of one year increment of coronary calcifications and survival in hemodialysis patients

<p>Abstract</p> <p>Background</p> <p>Heart and coronary calcifications in hemodialysis patients are of very common occurrence and linked to cardiovascular events and mortality. Several studies have been published with similar results. Most of them were mainly cross-sectional and some of the prospective protocols were aimed to evaluate the results of the control of altered biochemical parameters of mineral disturbances with special regard to serum calcium, phosphate and CaxP with the use of calcium containing and calcium free phosphate chelating agents. The aim of the present study was to evaluate in hemodialysis patients classic and some non classic risk factors as predictors of calcification changes after one year and to evaluate the impact of progression on survival.</p> <p>Methods</p> <p>81 patients on hemodialysis were studied, with a wide age range and HD vintage. Several classic parameters and some less classic risk factors were studied like fetuin-A, CRP, 25-OHD and leptin. Calcifications, as Agatston scores, were evaluated with Multislice CT basally and after 12-18 months.</p> <p>Results</p> <p>Coronary artery calcifications were observed in 71 of 81 patients. Non parametric correlations between Agatston scores and Age, HD Age, PTH and CRP were significant. Delta increments of Agatston scores correlated also with serum calcium, CaxP, Fetuin-A, triglycerides and serum albumin. Logistic regression analysis showed Age, PTH and serum calcium as important predictors of Delta Agatston scores. LN transformation of the not normally distributed variables restricted the significant correlations to Age, BMI and CRP. Considering the Delta Agatston scores as dependent, significant predictors were Age, PTH and HDL. A strong association was found between basal calcification scores and Delta increment at one year. By logistic analysis, the one year increments in Agatston scores were found to be predictors of mortality. Diabetic and hypertensive patients have significantly higher Delta scores.</p> <p>Conclusions</p> <p>Progression of calcification is of common occurrence, with special regard to elevated basal scores, and is predictive of survival. Higher predictive value of survival is linked to the one year increment of calcification scores. Some classic and non classic risk factors play an important role in progression. Some of them could be controlled with appropriate management with possible improvement of mortality.</p

Young-onset and late-onset Parkinson's disease exhibit a different profile of fluid biomarkers and clinical features

Young-onset Parkinson's disease (YOPD) is a relevant condition whose neurobiology is questioned if different from those of typical late-onset Parkinson's disease (LOPD). Here, we explored whether the clinical-biochemical profile of Parkinson's disease (PD) could be affected by the age-of-onset (AO), as a possible result of a distinct neurodegenerative process. A panel of fluid biomarkers (CSF lactate, 42-amyloid-β peptide, total and 181-phosphorylated tau; serum uric acid) and the standard scores for motor and nonmotor signs were assessed in 76 idiopathic PD patients (genetic cases excluded; YOPD, AO ≤ 50, n&nbsp;= 44; LOPD, AO &gt; 50, n&nbsp;= 32) and 75 sex/age-matched controls, adjusting the models for the main confounding factors. In PD, AO directly correlated to either CSF lactate and tau proteins or the nonmotor symptoms scale score. Specifically, a younger AO was associated with lower levels of biomarkers and minor burden of nonmotor symptoms. Our findings indicate that clinical-biochemical features of idiopathic PD may vary depending on the AO, accounting for different profiles in YOPD and LOPD whose recognition is fundamental for further pathophysiological implications and clinical applications