1,662 research outputs found

    Evidence for quantum confinement in the photoluminescence of porous Si and SiGe

    Get PDF
    We have used anodization techniques to process porous surface regions in p-type Czochralski Si and in p-type Si0.85Ge0.15 epitaxial layers grown by molecular beam epitaxy. The SiGe layers were unrelaxed before processing. We have observed strong near-infrared and visible light emission from both systems. Analysis of the radiative and nonradiative recombination processes indicate that the emission is consistent with the decay of excitons localized in structures of one or zero dimensions

    Do sperm and lubricants gel well with each other?:A systematic review

    Get PDF
    Vaginal lubricants are commonly used to aid sexual pleasure and/or to help combat vaginal dryness and dyspareunia. Several studies have reported their impact on sperm function, however there are no published guidelines to help healthcare professionals and couples select a vaginal lubricant that is 'sperm-safe'. To address this, we conducted a literature search using both PubMed and Scopus to identify and appraise manuscripts that reported the impact of lubricants on sperm function. We did not restrict the literature search by year of publication, and we only included manuscripts that looked at the impact of vaginal lubricants on human sperm. The quality of the eligible studies was assessed using the Björndahl et al., (2016) checklist for semen analysis, as most of the studies reported the findings of a basic semen analysis. A total of 24 articles were eligible for analysis with a total of 35 vaginal lubricants (that were available to buy over the counter) being included, 2 of which studied the effect of vaginal lubricants on sperm function in vivo, and 22 being conducted in vitro. KY Jelly, PreSeed and Astroglide were most studied, with most manuscripts focussing on their impact on sperm motility. A paucity of data on most lubricants combined with methodological variations between studies and limited/no reporting on pregnancy outcomes means greater efforts are required before an evidence-based guideline can be published.</p

    Oxidised micrometeorites as evidence for low atmospheric pressure on the early Earth

    Get PDF
    Reconstructing a record of the partial pressure of molecular oxygen in Earth’s atmosphere is key for understanding macroevolutionary and environmental change over geological history. Recently, the oxidation state of iron in micrometeorites has been taken to imply the presence of modern Earth concentrations of oxygen in the upper atmosphere at 2.7 Ga, and therefore a highly chemically stratified atmosphere (Tomkins et al., 2016). We here explore the possibility that the mixing ratio of oxygen in Earth’s upper atmosphere, that probed by micrometeorites, may instead be sensitive to the surface atmospheric pressure. We find that the concentrations of oxygen in the upper atmosphere required for micrometeorite oxidation are achieved for a 0.3 bar atmosphere. In this case, significant water vapour reaches high up in the atmosphere and is photodissociated, leading to the formation of molecular oxygen. The presence of oxidised iron in micrometeorites at 2.7 Ga may therefore be further evidence that the atmospheric pressure at the surface of the early Earth was substantially lower than it is today

    The impact of different liaison psychiatry models on the emergency department: A systematic review of the international evidence

    Get PDF
    Objective This review aimed to evaluate the current evidence for what impact different Liaison Psychiatry (LP) services are having on Emergency Departments (ED). Mental Health (MH) problems contribute to 12 million annual US ED attendances and 5% in the UK. Methods Databases were searched for articles describing LP services for adult MH patients attending EDs which reported ED care-related outcomes, published since 2000. Articles were screened and relevant articles quality assessed and narratively synthesized. Results 3653 articles were identified and 17 included in the review. Study designs were overall of poor-moderate quality, using retrospective before-and-after study designs. LP services were categorized into four models. Models with MH personnel integrated into the ED team or triage reduced patient waiting time to be seen, may reduce patients leaving without being seen and have high staff satisfaction. Co-located MH space or personnel reduced patient waiting times. Care agreements with existing psychiatry teams don't affect waiting times or ED length of stay. Transferring patients to external services reduces patients' time in the ED. There is insufficient evidence about patient satisfaction, costs, and onward care. Conclusions Waiting times are shortened by MH personnel integrated into the ED and are more satisfactory to staff than other LP models. The involvement of a psychiatrist in the LP team improves the care quality. All models may improve safety for patients but most evaluations are of poor quality and therefore there is still insufficient evidence to recommend one service model over another and further robust research is required

    Poly(n-butyl Methacrylate) with Primary Amine End Groups for Supporting Cell Adhesion and Proliferation of Renal Epithelial Cells

    Get PDF
    Polymer coatings that support epithelial cell culture have been developed. Ozonolysis and subsequent work up of poly(butyl methacrylate-co-butadiene) copolymers is used to form oligomers with carboxylic acid end groups, which are then further reacted with diamines to provide poly(butyl methacrylate)s with primary amine end groups. The polymers are cast as films and used as cell culture substrates for human dermal fibroblasts and human renal epithelial cells. Fibroblast and epithelial cells adhere and proliferate on acid functional materials but on amine functional films epithelial cells show greater viability than fibroblasts
    corecore