Scaling aerosol assisted chemical vapour deposition: Exploring the relationship between growth rate and film properties

Thin films of fluorine doped tin oxide were deposited, by an aerosol assisted chemical vapour deposition route, to study the effect of scaling the growth rate. The effect of precursor concentration on the growth rate of the films and the properties of deposited films were compared. The films were characterised by X-ray diffraction, scanning electron microscopy, UV/vis spectroscopy, X-ray photoelectron spectroscopy and Hall effect measurements. A maximum film growth rate of ca. 100 nm min− 1 was observed, which is significantly faster than previously reported aerosol assisted studies. This method shows the ability of aerosol assisted methods to deliver high growth rates whilst maintaining the ease of doping and control over stoichiometry

Boron isotope insights into the origin of subduction signatures in continent-continent collision zone volcanism

We present the first boron abundance and δ11B data for young (1.5-0 Ma) volcanic rocks formed in an active continent-continent collision zone. The δ11B of post-collisional volcanic rocks (−5 to +2‰) from the Armenian sector of the Arabia-Eurasia collision zone are heavier than mid-ocean ridge basalts (MORB), confirming trace element and isotope evidence for their derivation from a subduction-modified mantle source. Based on the low B/Nb (0.03-0.25 vs 0.2-90 in arc magmas), as well as low Ba/Th and Pb/Ce, this source records a subduction signature which is presently fluid-mobile element depleted relative to most arc settings. The heavier than MORB δ11B of post-collision volcanic rocks argues against derivation of their subduction signature from a stalled slab, which would be expected to produce a component with a lighter than MORB δ11B, due to previous fluid depletion. Instead, the similarity of δ11B in Plio-Pleistocene post-collision to 41 Ma alkaline igneous rocks also from Armenia (and also presented in this study), suggests that the subduction signature is inherited from Mesozoic-Paleogene subduction of Neotethys oceanic slabs. The slab component is then stored in the mantle lithosphere in amphibole, which is consistent with the low [B] in both Armenian volcanic rocks and metasomatic amphibole in mantle xenoliths. Based on trace element and radiogenic isotope systematics, this slab component is thought to be dominated by sediment melts (or supercritical fluids). Previously published δ11B of metasediments suggests a sediment-derived metasomatic agent could produce the B isotope composition observed in Armenian volcanic rocks. The lack of evidence for aqueous fluids preserved over the 40 Myr since initial collision supports observations that this latter component is transitory, while the lifetime of sediment melts/supercritical fluids can be extended to >40 Myr

Evidence for enhanced chromospheric Ca II H & K emission in stars with close-in extrasolar planets

The planet-star interaction is manifested in many ways. It was found out that a close-in exoplanet causes small but measurable variability in the cores of a few lines in the spectra of several stars which corresponds to the orbital period of the exoplanet. Stars with and without exoplanets may have different properties. The main goal of our study is to search for influence which exoplanets might have on atmospheres of their host stars. Unlike the previous studies, we do not study changes in the spectrum of a host star or differences between stars with and without exoplanets. We aim to study a large number of stars with exoplanets, current level of their chromospheric activity and look for a possible correlation with the exoplanetary properties. To analyse the chromospheric activity of stars we exploit our own (2.2m ESO/MPG telescope) and publicly available archival spectra (Keck Observatory Archive), measure the equivalent widths of the cores of Ca II H and K lines and use them as a tracer of their activity. Subsequently, we search for their dependence on the orbital parameters and mass of the exoplanet. We found a statistically significant evidence that the equivalent width of the Ca II K line emission and log R'_{HK} activity parameter of the host star varies with the semi-major axis and mass of the exoplanet. Stars with T_eff <= 5500 K having exoplanets with semi-major axis a <= 0.15 AU (P_orb <= 20 days) have a broad range of Ca II K emissions and much stronger emission in general than stars at similar temperatures but with higher values of semi-major axes. Ca II K emission of cold stars (T_eff <= 5500 K) with close-in exoplanets (a <= 0.15 AU) is also more pronounced for more massive exoplanets. The overall level of the chromospheric activity of stars may be affected by their close-in exoplanets. Stars with massive close-in exoplanets may be more active.Comment: 9 pages, 8 figures, 1 tabl

Optimized Atmospheric-Pressure Chemical Vapor Deposition Thermochromic VO2 Thin Films for Intelligent Window Applications

Monoclinic vanadium(IV) oxide (VO2) has been widely studied for energy-efficient glazing applications because of its thermochromic properties, displaying a large change in transmission of near-IR wavelengths between the hot and cold states. The optimization of the reaction between VCl4 and ethyl acetate via atmospheric-pressure chemical vapor deposition (APCVD) was shown to produce thin films of monoclinic VO2 with excellent thermochromic properties (ΔTsol = 12%). The tailoring of the thermochromic and visible light transmission was shown to be possible by altering the density and morphology of the deposited films. The films were characterized by X-ray diffraction, atomic-force microscopy, scanning electron microscopy, ellipsometry, and UV–vis spectrometry. This article provides useful design rules for the synthesis of high-quality VO2 thin films by APCVD

A DFT study of addition reaction between fragment ion (CH2) units and fullerene (C60) molecule

The theoretical study of the interaction between CH2 and fullerene (C60) suggests the existence of an addition reaction mechanism; this feature is studied by applying an analysis of electronic properties. Several different effects are evident in this interaction as a consequence of the particular electronic transfer which occurs during the procedure. The addition or insertion of the methylene group results in a process, where the inclusion of CH2 into a fullerene bond produces the formation of several geometric deformations. A simulation of these procedures was carried out, taking advantage of the dynamic semi-classical Born-Oppenheimer approximation. Dynamic aspects were analyzed at different speeds, for the interaction between the CH2 group and the two bonds: CC (6, 6) and CC (6, 5) respectively on the fullerene (C60) rings. All calculations which involved electrons employed DFT as well as exchange and functional correlation. The results indicate a tendency for the CH2 fragment to attack the CC (6, 5) bond

Men and infant feeding: Perceptions of embarrassment, sexuality, and social conduct in white low-income British men

Copyright @ 2010 The Authors. This is the accepted version of the following article: Henderson, L., McMillan, B., Green, J. M. and Renfrew, M. J. (2011), Men and Infant Feeding: Perceptions of Embarrassment, Sexuality, and Social Conduct in White Low-Income British Men. Birth, 38: 61–70, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1111/j.1523-536X.2010.00442.x/abstract.Background:  The views of fathers have been shown to be important determinants of infant feeding decisions, but men’s perceptions of breastfeeding and formula feeding are rarely explored. Our objectives were to address this gap and examine cultural associations and beliefs concerning infant feeding practices among men. Methods:  Five focus groups were conducted with low-income men (n = 28) living in areas of social deprivation in Leeds, northeast of England, and low-income areas of Glasgow, west of Scotland. Participants were white British men, aged between 16 and 45 years, and included fathers, expectant fathers, and potential fathers. Results:  Overarching themes concerning sexuality, embarrassment, and social conduct were identified across all groups. Participants perceived breastfeeding as “natural” but problematic, whereas formula feeding was mainly considered as convenient and safe. Participants without direct experience of breastfeeding assumed that it involved excessive public exposure and attracted unwanted male attention. Underpinning these fears were strong cultural associations between breasts and sexuality and anxieties concerning appropriate gender roles. Conclusions:  In some communities few opportunities may occur to witness breastfeeding, and thus existing fears concerning the activity as attracting predatory male attention remain unchallenged. Perceptions of breastfeeding as a sexual activity and the dominant mass media emphasis on breasts as a sexual site may present additional obstacles to breastfeeding. Antenatal or perinatal education with men should address not only practical issues but also provide advice on tackling problems generated by wider sociocultural issues of sexuality and masculinity

Protocol of a systematic review and network meta-analysis for the prevention and treatment of perinatal depression

Introduction Perinatal depression is common and can often lead to adverse health outcomes for mother and child. Multiple pharmacological and non-pharmacological treatments have been evaluated against usual care or placebo controls in meta-analyses for preventing and treating perinatal depression compared. It is not yet established which of these candidate treatments might be the optimal approach for prevention or treatment. Methods and analysis A systematic review and Bayesian network meta-analyses will be conducted. Eight electronic databases shall be searched for randomised controlled trials that have evaluated the effectiveness of treatments for prevention and/or treatment of perinatal depression. Screening of articles shall be conducted by two reviewers independently. One network meta-analysis shall evaluate the effectiveness of interventions in preventing depression during the perinatal period. A second network meta-analysis shall compare the effectiveness of treatments for depression symptoms in women with perinatal depression. Bayesian 95% credible intervals shall be used to estimate the pooled mean effect size of each treatment, and surface under cumulative ranking area will be used to rank the treatments\u27 effectiveness. Ethics and dissemination We shall report our findings so that healthcare providers can make informed decisions on what might be the optimal approach for addressing perinatal depression to prevent cases and improve outcomes in those suffering from depression through knowledge exchange workshops, international conference presentations and journal article publications. PROSPERO registration number CRD42020200081

Healthcare-associated outbreak of meticillin-resistant Staphylococcus aureus bacteraemia: role of a cryptic variant of an epidemic clone

BACKGROUND New strains of meticillin-resistant Staphylococcus aureus (MRSA) may be associated with changes in rates of disease or clinical presentation. Conventional typing techniques may not detect new clonal variants that underlie changes in epidemiology or clinical phenotype. AIM To investigate the role of clonal variants of MRSA in an outbreak of MRSA bacteraemia at a hospital in England. METHODS Bacteraemia isolates of the major UK lineages (EMRSA-15 and -16) from before and after the outbreak were analysed by whole-genome sequencing in the context of epidemiological and clinical data. For comparison, EMRSA-15 and -16 isolates from another hospital in England were sequenced. A clonal variant of EMRSA-16 was identified at the outbreak hospital and a molecular signature test designed to distinguish variant isolates among further EMRSA-16 strains. FINDINGS By whole-genome sequencing, EMRSA-16 isolates during the outbreak showed strikingly low genetic diversity (P < 1 × 10(-6), Monte Carlo test), compared with EMRSA-15 and EMRSA-16 isolates from before the outbreak or the comparator hospital, demonstrating the emergence of a clonal variant. The variant was indistinguishable from the ancestral strain by conventional typing. This clonal variant accounted for 64/72 (89%) of EMRSA-16 bacteraemia isolates at the outbreak hospital from 2006. CONCLUSIONS Evolutionary changes in epidemic MRSA strains not detected by conventional typing may be associated with changes in disease epidemiology. Rapid and affordable technologies for whole-genome sequencing are becoming available with the potential to identify and track the emergence of variants of highly clonal organisms

Advances in ophthalmic drug delivery

Various strategies for ocular drug delivery are considered; from basic formulation techniques for improving availability of drugs; viscosity enhancers and mucoadhesives aid drug retention and penetration enhancers promote drug transport into the eye. The use of drug loaded contact lenses and ocular inserts allows drugs to be better placed where they are needed for more direct delivery. Developments in ocular implants gives a means to overcome the physical barriers that traditionally prevented effective treatment. Implant technologies are under development allowing long term drug delivery from a single procedure, these devices allow posterior chamber diseases to be effectively treated. Future developments could bring artificial corneas to eliminate the need for donor tissue and one-off implantable drug depots lasting the patient’s lifetime

Gain control network conditions in early sensory coding

Gain control is essential for the proper function of any sensory system. However, the precise mechanisms for achieving effective gain control in the brain are unknown. Based on our understanding of the existence and strength of connections in the insect olfactory system, we analyze the conditions that lead to controlled gain in a randomly connected network of excitatory and inhibitory neurons. We consider two scenarios for the variation of input into the system. In the first case, the intensity of the sensory input controls the input currents to a fixed proportion of neurons of the excitatory and inhibitory populations. In the second case, increasing intensity of the sensory stimulus will both, recruit an increasing number of neurons that receive input and change the input current that they receive. Using a mean field approximation for the network activity we derive relationships between the parameters of the network that ensure that the overall level of activity of the excitatory population remains unchanged for increasing intensity of the external stimulation. We find that, first, the main parameters that regulate network gain are the probabilities of connections from the inhibitory population to the excitatory population and of the connections within the inhibitory population. Second, we show that strict gain control is not achievable in a random network in the second case, when the input recruits an increasing number of neurons. Finally, we confirm that the gain control conditions derived from the mean field approximation are valid in simulations of firing rate models and Hodgkin-Huxley conductance based models