Synthesis of Rutile Nb: TiO2 Free-Standing Thin Film at the Liquid-Air Interface

One‐step hydrothermal synthesis of the niobium doped rutile TiO2 free standing film at the liquid–air interface without the use of a template is presented. Film is flexible within first few minutes of removal from the solution and allows application on various shaped objects and substrates

Phase quantification by X-ray photoemission valence band analysis applied to mixed phase TiO2 powders

A method of quantitative phase analysis using valence band X-ray photoelectron spectra is presented and applied to the analysis of TiO 2 anatase-rutile mixtures. The valence band spectra of pure TiO 2 polymorphs were measured, and these spectral shapes used to fit valence band spectra from mixed phase samples. Given the surface sensitive nature of the technique, this yields a surface phase fraction. Mixed phase samples were prepared from high and low surface area anatase and rutile powders. In the samples studied here, the surface phase fraction of anatase was found to be linearly correlated with photocatalytic activity of the mixed phase samples, even for samples with very different anatase and rutile surface areas. We apply this method to determine the surface phase fraction of P25 powder. This method may be applied to other systems where a surface phase fraction is an important characteristic

Particle size, morphology and phase transitions in hydrothermally produced VO2(D)

Different morphologies and sizes of VO 2 (D) particles were synthesised via hydrothermal synthesis using ammonium metavanadate (NH 4 VO 3 ) or vanadium pentoxide (V 2 O 5 ) as a vanadium precursor. By adjusting the concentration of vanadium precursors and the pH of the starting solution, a variety of morphologies and sizes of VO 2 (D) particles from 20 nm to 3 μm could be produced. A flower-shape morphology was obtained under strongly acidic conditions, passing through star-shape particles of 1 μm at pH 2.5 and finally obtaining homogeneous round balls of around 3 μm at pH 6.9. Nanoparticles were produced hydrothermally using V 2 O 5 as a precursor and hydrazine as a reducing agent. The transition from VO 2 (D) to thermochromic VO 2 (R) in micron scale particles occurred at 350 °C under vacuum. However, the nanoparticles of VO 2 (D) had a significantly lower VO 2 (D) to thermochromic VO 2 (R) transition temperature of 165 °C after annealing for only a few minutes. This is, to our knowledge, the lowest annealing temperature and time reported in the literature in order to obtain a thermochromic VO 2 material via another VO 2 phase. After the conversion of VO 2 (D) microparticles to thermochromic VO 2 (R), the metal to insulator transition temperature is 61 ± 1 °C for the heating cycle and 53 ± 1 °C for the cooling cycle. However, VO 2 (R) nanoparticles showed a significantly reduced metal insulator transition temperature of 59 ± 1 °C and 42 ± 1 °C for the cooling cycle lower than that reported in the literature for bulk VO 2 . This is important due to the need for having a compound with a switching temperature closer to room temperature to be used in smart window devices for energy consumption. W-VO 2 (D) star shape microparticle samples were prepared using 2-7 at% of the dopant (using ammonium metavanadate as a precursor), although unexpectedly this does not seem to be a viable route to a reduced metal to insulator transition in this system

Women and Primary Biliary Cirrhosis

Primary biliary cirrhosis occurs more frequently in women, and previous studies indicated that the average age of primary biliary cirrhosis (PBC) onset makes pregnancy in PBC patients uncommon. However, more recently, improved diagnostic testing has enabled detection of PBC in younger women, including those of childbearing age. This has led investigators to become increasingly interested in the relationship between the ontogeny of PBC and pregnancy. Published cases indicate that the typical age for pregnant women to be diagnosed with PBC is in the early 30s, and that during gestation, pruritus and jaundice are the most common symptoms. During gestation, susceptible women may experience onset of PBC resulting from the drastic changes in female hormones; this would include not only the mitochondrial damage due to accumulation of bile acids but also changes in the immune response during the different stages of pregnancy that might play an important role in the breakdown of self-tolerance. The mechanisms underlying the potential relationship between PBC and pregnancy warrant further investigation. For women first diagnosed with PBC during gestation, or those for whom first appearance of a flare up occurs during and postpartum, investigation of the immune response throughout gestation could provide new avenues for immunologic therapeutic intervention and the discovery of new treatment strategies for PBC