Optimization of a high work function solution processed vanadium oxide hole-extracting layer for small molecule and polymer organic photovoltaic cells

We report a method of fabricating a high work function, solution processable vanadium oxide (V2Ox(sol)) hole-extracting layer. The atmospheric processing conditions of film preparation have a critical influence on the electronic structure and stoichiometry of the V2Ox(sol), with a direct impact on organic photovoltaic (OPV) cell performance. Combined Kelvin probe (KP) and ultraviolet photoemission spectroscopy (UPS) measurements reveal a high work function, n-type character for the thin films, analogous to previously reported thermally evaporated transition metal oxides. Additional states within the band gap of V2Ox(sol) are observed in the UPS spectra and are demonstrated using X-ray photoelectron spectroscopy (XPS) to be due to the substoichiometric nature of V2Ox(sol). The optimized V2Ox(sol) layer performance is compared directly to bare indium–tin oxide (ITO), poly(ethyleneoxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and thermally evaporated molybdenum oxide (MoOx) interfaces in both small molecule/fullerene and polymer/fullerene structures. OPV cells incorporating V2Ox(sol) are reported to achieve favorable initial cell performance and cell stability attributes

Imperfections in a two-dimensional hierarchical structure

Hierarchical and fractal designs have been shown to yield high mechanical efficiency under a variety of loading conditions. Here a fractal frame is optimized for compressive loading in a two-dimensional space. We obtain the dependence of volume required for stability against loading for which the structure is optimized and a set of scaling relationships is found. We evaluate the dependence of the Hausdorff dimension of the optimal structure on the applied loading and establish the limit to which it tends under gentle loading. We then investigate the effect of a single imperfection in the structure through both analytical and simulational techniques. We find that a single asymmetric perturbation of beam thickness, increasing or decreasing the failure load of the individual beam, causes the same decrease in overall stability of the structure. A scaling relationship between imperfection magnitude and decrease in failure loading is obtained. We calculate theoretically the limit to which the single perturbation can effect the overall stability of higher generation frames

Blue laser cooling transitions in Tm I

We have studied possible candidates for laser cooling transitions in $^{169}$Tm in the spectral region 410 -- 420 nm. By means of saturation absorption spectroscopy we have measured the hyperfine structure and rates of two nearly closed cycling transitions from the ground state $4\textrm{f}^{13}6\textrm{s}^2(^2\textrm{F}_0)(J_g=7/2)$ to upper states $4\textrm{f}^{12}(^3\textrm{H}_5)5\textrm{d}_{3/2}6\textrm{s}^2(J_e=9/2)$ at 410.6 nm and $4\textrm{f}^{12}(^3\textrm{F}_4)5\textrm{d}_{5/2}6\textrm{s}^2(J_e=9/2)$ at 420.4 nm and evaluated the life times of the excited levels as 15.9(8) ns and 48(6) ns respectively. Decay rates from these levels to neighboring opposite-parity levels are evaluated by means of Hartree-Fock calculations. We conclude, that the strong transition at 410.6 nm has an optical leak rate of less then $2\cdot10^{-5}$ and can be used for efficient laser cooling of $^{169}$Tm from a thermal atomic beam. The hyperfine structure of two other even-parity levels which can be excited from the ground state at 409.5 nm and 418.9 nm is also measured by the same technique. In addition we give a calculated value of $7(2)$ s$^{-1}$ for the rate of magnetic-dipole transition at 1.14 $\mu$m between the fine structure levels $(J_g=7/2)\leftrightarrow(J'_g=5/2)$ of the ground state which can be considered as a candidate for applications in atomic clocks.Comment: 8 pages, 5 figure

Investigating the association between obesity and asthma in 6- to 8-year-old Saudi children:a matched case-control study

Background: Previous studies have demonstrated an association between obesity and asthma, but there remains considerable uncertainty about whether this reflects an underlying causal relationship. Aims: To investigate the association between obesity and asthma in pre-pubertal children and to investigate the roles of airway obstruction and atopy as possible causal mechanisms. Methods: We conducted an age- and sex-matched case–control study of 1,264 6- to 8-year-old schoolchildren with and without asthma recruited from 37 randomly selected schools in Madinah, Saudi Arabia. The body mass index (BMI), waist circumference and skin fold thickness of the 632 children with asthma were compared with those of the 632 control children without asthma. Associations between obesity and asthma, adjusted for other potential risk factors, were assessed separately in boys and girls using conditional logistic regression analysis. The possible mediating roles of atopy and airway obstruction were studied by investigating the impact of incorporating data on sensitisation to common aeroallergens and measurements of lung function. Results: BMI was associated with asthma in boys (odds ratio (OR)=1.14, 95% confidence interval (CI), 1.08–1.20; adjusted OR=1.11, 95% CI, 1.03–1.19) and girls (OR=1.37, 95% CI, 1.26–1.50; adjusted OR=1.38, 95% CI, 1.23–1.56). Adjusting for forced expiratory volume in 1 s had a negligible impact on these associations, but these were attenuated following adjustment for allergic sensitisation, particularly in girls (girls: OR=1.25; 95% CI, 0.96–1.60; boys: OR=1.09, 95% CI, 0.99–1.19). Conclusions: BMI is associated with asthma in pre-pubertal Saudi boys and girls; this effect does not appear to be mediated through respiratory obstruction, but in girls this may at least partially be mediated through increased risk of allergic sensitisation

Tolerance to bronchodilation during treatment with long-acting beta-agonists, a randomised controlled trial

BACKGROUND: Regular use of beta-agonists leads to tolerance to their bronchodilator effects. This can be demonstrated by measuring the response to beta-agonist following bronchoconstriction using methacholine. However most studies have demonstrated tolerance after a period of beta-agonist withdrawal, which is not typical of their use in clinical practice. This study assessed tolerance to the bronchodilator action of salbutamol during ongoing treatment with long-acting beta-agonist. METHODS: Random-order, double-blind, placebo-controlled, crossover trial. After 1 week without beta-agonists, 13 asthmatic subjects inhaled formoterol 12 μg twice daily or matching placebo for 1 week. Eight hours after the first and last doses subjects inhaled methacholine to produce a 20% fall in FEV(1). Salbutamol 100, 200 and 400 μg (cumulative dose) was then given at 5-minute intervals and FEV(1 )was measured 5 minutes after each dose. After a 1 week washout subjects crossed over to the other treatment. Unscheduled use of beta-agonists was not allowed during the study. The main outcome variable was the area under the salbutamol response curve. RESULTS: The analysis showed a significant time by treatment interaction indicating that the response to salbutamol fell during formoterol therapy compared to placebo. After 1 week of formoterol the area under the salbutamol response curve was 48% (95% confidence interval 28 to 68%) lower than placebo. This reduction in response remained significant when the analyses were adjusted for changes in the pre-challenge FEV(1 )and dose of methacholine given (p = 0.001). CONCLUSION: The bronchodilator response to salbutamol is significantly reduced in patients taking formoterol. Clinically relevant tolerance to rescue beta-agonist treatment is likely to occur in patients treated with long-acting beta-agonists

Technical Report: Review and Simulate Climate and Catchment Responses at Burrishoole (RESCALE)

Lead Partner: Department of Geography, National University of Ireland Maynooth Project Partners: School of Natural Sciences, Trinity College Dublin Marine Institute, Furnace, Newport, Co. MayoThis report demonstrates that the projected changes in the climate conditions of the Burrishoole catchment, if realised, will have wide ranging implications for all aspects of the catchment system, including water temperature and quality, stream flow hydrology, soil processes, and most notably the well-being of its aquatic environment. While the projected changes in climate and their implications, outlined in this report, are specific to the Burrishoole, they are illustrative of likely changes in similar characteristic catchments along the west coast of Ireland.Funder: Marine Institut

Atrial Heterogeneity Generates Re-entrant Substrate during Atrial Fibrillation and Anti-arrhythmic Drug Action: Mechanistic Insights from Canine Atrial Models

Anti-arrhythmic drug therapy is a frontline treatment for atrial fibrillation (AF), but its success rates are highly variable. This is due to incomplete understanding of the mechanisms of action of specific drugs on the atrial substrate at different stages of AF progression. We aimed to elucidate the role of cellular, tissue and organ level atrial heterogeneities in the generation of a re-entrant substrate during AF progression, and their modulation by the acute action of selected anti-arrhythmic drugs. To explore the complex cell-to-organ mechanisms, a detailed biophysical models of the entire 3D canine atria was developed. The model incorporated atrial geometry and fibre orientation from high-resolution micro-computed tomography, region-specific atrial cell electrophysiology and the effects of progressive AF-induced remodelling. The actions of multi-channel class III anti-arrhythmic agents vernakalant and amiodarone were introduced in the model by inhibiting appropriate ionic channel currents according to experimentally reported concentration-response relationships. AF was initiated by applied ectopic pacing in the pulmonary veins, which led to the generation of localized sustained re-entrant waves (rotors), followed by progressive wave breakdown and rotor multiplication in both atria. The simulated AF scenarios were in agreement with observations in canine models and patients. The 3D atrial simulations revealed that a re-entrant substrate was typically provided by tissue regions of high heterogeneity of action potential duration (APD). Amiodarone increased atrial APD and reduced APD heterogeneity and was more effective in terminating AF than vernakalant, which increased both APD and APD dispersion. In summary, the initiation and sustenance of rotors in AF is linked to atrial APD heterogeneity and APD reduction due to progressive remodelling. Our results suggest that anti-arrhythmic strategies that increase atrial APD without increasing its dispersion are effective in terminating AF

High body mass index is not associated with atopy in schoolchildren living in rural and urban areas of Ghana

<p>Abstract</p> <p>Background</p> <p>Factors which determine the development of atopy and the observed rural-urban gradient in its prevalence are not fully understood. High body mass index (BMI) has been associated with asthma and potentially atopy in industrialized countries. In developing countries, the transition from rural to urban areas has been associated with lifestyle changes and an increased prevalence of high BMI; however, the effect of high BMI on atopy remains unknown in this population. We therefore investigated the association between high BMI and atopy among schoolchildren living in rural and urban areas of Ghana.</p> <p>Methods</p> <p>Data on skin prick testing, anthropometric, parasitological, demographic and lifestyle information for 1,482 schoolchildren aged 6-15 years was collected. Atopy was defined as sensitization to at least one tested allergen whilst the Centres for Disease Control and Prevention (CDC, Atlanta) growth reference charts were used in defining high BMI as BMI ≥ the 85^thpercentile. Logistic regression was performed to investigate the association between high BMI and atopy whilst adjusting for potential confounding factors.</p> <p>Results</p> <p>The following prevalences were observed for high BMI [Rural: 16%, Urban: 10.8%, p < 0.001] and atopy [Rural: 25.1%, Urban: 17.8%, p < 0.001]. High BMI was not associated with atopy; but an inverse association was observed between underweight and atopy [OR: 0.57, 95% CI: 0.33-0.99]. Significant associations were also observed with male sex [Rural: OR: 1.49, 95% CI: 1.06-2.08; Urban: OR: 1.90, 95% CI: 1.30-2.79], and in the urban site with older age [OR: 1.76, 95% CI: 1.00-3.07], family history of asthma [OR: 1.58, 95% CI: 1.01-2.47] and occupational status of parent [OR: 0.33, 95% CI: 0.12-0.93]; whilst co-infection with intestinal parasites [OR: 2.47, 95% CI: 1.01-6.04] was associated with atopy in the rural site. After multivariate adjustment, male sex, older age and family history of asthma remained significant.</p> <p>Conclusions</p> <p>In Ghanaian schoolchildren, high BMI was not associated with atopy. Further studies are warranted to clarify the relationship between body weight and atopy in children subjected to rapid life-style changes associated with urbanization of their environments.</p

Chemical Proteomics-Based Analysis of Off-target Binding Profiles for Rosiglitazone and Pioglitazone: Clues for Assessing Potential for Cardiotoxicity

Drugs exert desired and undesired effects based on their binding interactions with protein target(s) and off-target(s), providing evidence for drug efficacy and toxicity. Pioglitazone and rosiglitazone possess a common functional core, glitazone, which is considered a privileged scaffold upon which to build a drug selective for a given target—in this case, PPARγ. Herein, we report a retrospective analysis of two variants of the glitazone scaffold, pioglitazone and rosiglitazone, in an effort to identify off-target binding events in the rat heart to explain recently reported cardiovascular risk associated with these drugs. Our results suggest that glitazone has affinity for dehydrogenases, consistent with known binding preferences for related rhodanine cores. Both drugs bound ion channels and modulators, with implications in congestive heart failure, arrhythmia, and peripheral edema. Additional proteins involved in glucose homeostasis, synaptic transduction, and mitochondrial energy production were detected and potentially contribute to drug efficacy and cardiotoxicity

A survey of combustible metals, thermites, and intermetallics for pyrotechnic applications

Thermite mixtures, intermetallic reactants, and metal fuels have long been used in pyrotechnics. Advantages include high energy density, impact insensitivity, high combustion temperature, and a wide range of gas production. They generally exhibit high temperature stability and possess insensitive ignition properties. This paper reviews the applications, benefits, and characteristics of thermite mixtures, intermetallic reactants, and metal fuels. 50 refs, tables