Combined Theoretical and Experimental Study of the Moiré Dislocation Network at the SrTiO-(La,Sr)(Al,Ta)O Interface.

Recently, a highly ordered Moiré dislocation lattice was identified at the interface between a SrTiO (STO) thin film and the (LaAlO)(SrTaAlO) (LSAT) substrate. A fundamental understanding of the local ionic and electronic structures around the dislocation cores is crucial to further engineer the properties of these complex multifunctional heterostructures. Here, we combine experimental characterization via analytical scanning transmission electron microscopy with results of molecular dynamics and density functional theory calculations to gain insights into the structure and defect chemistry of these dislocation arrays.

Conversion of LaTiO to LaTiON ammonolysis: a first-principles investigation.

Perovskite oxynitrides are, due to their reduced band gap compared to oxides, promising materials for photocatalytic applications. They are most commonly synthesized from {110} layered Carpy-Galy (ABO) perovskites thermal ammonolysis, the exposure to a flow of ammonia at elevated temperature. The conversion of the layered oxide to the non-layered oxynitride must involve a complex combination of nitrogen incorporation, oxygen removal and ultimately structural transition by elimination of the interlayer shear plane.

Photochemical anisotropy and direction-dependent optical absorption in semiconductors.

Photochemical reactions on semiconductors are anisotropic, since they occur with different rates on surfaces of different orientations. Understanding the origin of this anisotropy is crucial to engineering more efficient photocatalysts. In this work, we use hybrid density functional theory to identify the surfaces associated with the largest number of photo-generated carriers in different semiconductors.

Ferroelectricity promoted by cation/anion divacancies in SrMnO.

We investigate the effect of polar Sr-O vacancy pairs on the electric polarization of SrMnO (SMO) thin films using density functional theory (DFT) calculations. This is motivated by indications that ferroelectricity in complex oxides can be engineered by epitaxial strain but also the defect chemistry. Our results suggest that intrinsic doping by cation and anion divacancies can induce a local polarization in unstrained non-polar SMO thin films and that a ferroelectric state can be stabilized below the critical strain of the stoichiometric material.

TGF Beta Induces Vitamin D Receptor and Modulates Mitochondrial Activity of Human Pancreatic Cancer Cells.

The inflammatory cytokine TGFβ is both a tumor suppressor during cancer initiation and a promoter of metastasis along cancer progression. Inflammation and cancer are strictly linked, and cancer onset often correlates with the insufficiency of vitamin D, known for its anti-inflammatory properties. In this study, we investigated the interplay between TGFβ and vitamin D in two models of human pancreatic cancer, and we analyzed the metabolic effects of a prolonged TGFβ treatment mimicking the inflammatory environment of pancreatic cancer in vivo.