Honeycomb and triangular domain wall networks in heteroepitaxial systems

© 2016 Author(s).A comprehensive study is presented for the influence of misfit strain, adhesion strength, and lattice symmetry on the complex Moiré patterns that form in ultrathin films of honeycomb symmetry adsorbed on compact triangular or honeycomb substrates. The method used is based on a complex Ginzburg-Landau model of the film that incorporates elastic strain energy and dislocations. The results indicate that different symmetries of the heteroepitaxial systems lead to distinct types of domain wall networks and phase transitions among various surface Moiré patterns and superstructures. More specifically, the results show a dramatic difference between the phase diagrams that emerge when a honeycomb film is adsorbed on substrates of honeycomb versus triangular symmetry. It is also shown that in the small deformation limit, the complex Ginzburg-Landau model reduces to a two-dimensional sine-Gordon free energy form. This free energy can be solved exactly for one dimensional patterns and reveals the role of domains walls and their crossings in determining the nature of the phase diagrams

An optical fibre-based sensor for real-time monitoring of clinical linear accelerator radiotherapy delivery

A novel real-time optical fibre X-Ray dosimeter for monitoring the radiation pulses delivered from a clinical linear accelerator (Linac) is presented. The primary focus of the sensor is to measure low doses of ionising X-ray radiation in real time (limited to 0.1-ms gate time of the detector). The sensor tip material scintillates upon exposure to X-ray energy and the resultant low-level visible light signal is coupled to a polymethyl methacrylate plastic optical fibre, which is used to guide it towards a distal avalanche photodiode-based detector. The detector measures the low-level scintillating light from the sensor, thereby converting the ionizing radiation energy to a measurable signal with a time resolution of 0.1 ms. Results show that the scintillating optical fibre X-ray dosimeter is capable of capturing the individual X-Ray pulses delivered by the Linac during normal operation. Further examination of the results demonstrates that the sensor is capable of measuring dose rate and, hence, dose with a linearity (R-2 = 0.9995 - 0.9999) and in a highly repeatable manner for dose rates in the range 100 to 600 monitor units/min

Imbalance between proliferation and apoptosis-related impaired GPR30 expression is involved in preeclampsia.

The proliferation and apoptosis of cells in the placenta play a critical role in preeclampsia (PE) in which estrogen has been implicated via estrogen receptors (ERs). A novel ER, G-protein-coupled receptor 30 (GPR30), has recently been shown to be involved in PE. We investigated the basic levels of proliferation and apoptosis in normal placentae and placentae with PE and compared GPR30 expression levels between the two groups. We demonstrated that low GPR30 expression levels, more apoptosis, and less proliferation were associated with PE. Moreover, our in vitro study showed that both the selective GPR30 agonist G1 and the general ER agonist 17-β-estradiol were able to protect the placenta from hypoxia-reoxygenation injuries, resulting in decreased apoptosis and increased proliferation. Furthermore, this protective effect was abolished by the addition of the selective GPR30 inhibitor G15. These results provide evidence that (1) GPR30 is involved in regulating cell proliferation and apoptosis; (2) pharmacologic upregulation of GPR30 is beneficial for PE management; (3) GPR30 may therefore be an interventional target for pregnancies complicated by PE

Interfacial Effects in ε‑Li_<i>x</i>VOPO₄ and Evolution of the Electronic Structure

The epsilon polymorph of vanadyl phosphate ε-VOPO₄ is a promising cathode material for high-capacity Li ion batteries, owing to its demonstrated ability to reversibly incorporate two lithium ions per redox center. As lithium is inserted into the nanosized particles within the cathode, the electrochemical reaction can be largely affected by the interfacial chemistry at the nanoparticle surface. We performed X-ray photoelectron spectroscopy using both soft (XPS) and hard (HAXPES) X-rays to chemically distinguish and depth-resolve the interfacial phase transitions in ε-VOPO₄ electrodes as a function of electrochemical discharge. Our analysis shows that the second lithium reaction begins before the full incorporation of the first lithium. This results in a pronounced lithium gradient within the nanoparticles, with the ε-Li₂VOPO₄ phase only forming near the surface. These results indicate that a disruption of the kinetics are limiting the realized capacity in our hydrothermally synthesized ε-VOPO₄. Moreover, from inspection of the valence band region, we were able to monitor the evolution of ε-VOPO₄ to ε-Li₂VOPO₄ at the surface of our nanoparticles. These assignments are confirmed by hybrid density functional theory of the three end phases

Genome-wide association analyses for lung function and chronic obstructive pulmonary disease identify new loci and potential druggable targets

Chronic Obstructive Pulmonary Disease (COPD) is characterised by reduced lung function and is the third leading cause of death globally. Through genome-wide association discovery in 48,943 individuals, selected from extremes of the lung function distribution in UK Biobank, and follow-up in 95,375 individuals, we increased the yield of independent signals for lung function from 54 to 97. A genetic risk score was associated with COPD susceptibility (odds ratios per standard deviation of the risk score (~6 alleles) (95% confidence interval) 1.24 (1.20-1.27), P=5.05x10^-49) and we observed a 3.7 fold difference in COPD risk between highest and lowest genetic risk score deciles in UK Biobank. The 97 signals show enrichment in development, elastic fibres and epigenetic regulation pathways. We highlight targets for drugs and compounds in development for COPD and asthma (genes in the inositol phosphate metabolism pathway and CHRM3) and describe targets for potential drug repositioning from other clinical indications