9,333 research outputs found

    Concentration and size distribution data of silicon nitride nanoparticles measured using nanoparticle tracking analysis

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    This article refers to the paper “A novel method for isolation and recovery of ceramic nanoparticles and metal wear debris from serum lubricants at ultra-low wear rates” (Lal et al., 2016) [1] and describes the concentration and size distribution data of silicon nitride nanoparticles measured using nanoparticle tracking analysis (NTA). A NanoSight LM10 instrument was used to capture the video data of silicon nitride nanoparticles moving under Brownian motion in the water. The video data was then analyzed using the NanoSight NTA software. This article also describes a methodology for calculating the percentage recovery of a nanoparticle isolation process

    Benthic foraminifera show some resilience to ocean acidification in the northern Gulf of California, Mexico.

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    The version on PEARL: Corrected proofs are Articles in Press that contain the authors' corrections. Final citation details, e.g., volume/issue number, publication year and page numbers, still need to be added and the text might change before final publication. Although corrected proofs do not have all bibliographic details available yet, they can already be cited using the year of online publication and the DOI , as follows: author(s), article title, journal (year), DOIExtensive CO2 vents have been discovered in the Wagner Basin, northern Gulf of California, where they create large areas with lowered seawater pH. Such areas are suitable for investigations of long-term biological effects of ocean acidification and effects of CO2 leakage from subsea carbon capture storage. Here, we show responses of benthic foraminifera to seawater pH gradients at 74-207m water depth. Living (rose Bengal stained) benthic foraminifera included Nonionella basispinata, Epistominella bradyana and Bulimina marginata. Studies on foraminifera at CO2 vents in the Mediterranean and off Papua New Guinea have shown dramatic long-term effects of acidified seawater. We found living calcareous benthic foraminifera in low pH conditions in the northern Gulf of California, although there was an impoverished species assemblage and evidence of post-mortem test dissolution

    Biological Impact of Silicon Nitride for Orthopaedic Applications: Role of Particle Size, Surface Composition and Donor Variation

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    The adverse biological impact of orthopaedic wear debris currently limits the long-term safety of human joint replacement devices. We investigated the role of particle size, surface composition and donor variation in influencing the biological impact of silicon nitride as a bioceramic for orthopaedic applications. Silicon nitride particles were compared to the other commonly used orthopaedic biomaterials (e.g. cobalt-chromium and Ti-6Al-4V alloys). A novel biological evaluation platform was developed to simultaneously evaluate cytotoxicity, inflammatory cytokine release, oxidative stress, and genotoxicity potential of particles using peripheral blood mononuclear cells (PBMNCs) from individual human donors. Irrespective of the particle size, silicon nitride did not cause any adverse responses whereas cobalt-chromium wear particles caused donor-dependent cytotoxicity, TNF-α cytokine release, oxidative stress, and DNA damage in PBMNCs after 24 h. Despite being similar in size and morphology, silicon dioxide nanoparticles caused the release of significantly higher levels of TNF-α compared to silicon nitride nanoparticles, suggesting that surface composition influences the inflammatory response in PBMNCs. Ti-6Al-4V wear particles also released significantly elevated levels of TNF-α cytokine in one of the donors. This study demonstrated that silicon nitride is an attractive orthopaedic biomaterial due to its minimal biological impact on human PBMNCs

    Wear simulation of a polyethylene-on-metal cervical total disc replacement under different concentrations of bovine serum lubricant

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    Metal-on-polyethylene total disc replacements have been an alternative to spinal fusion in the lumbar spine under certain indications for more than a decade. Recently, cervical total disc replacement has also become an alternative to cervical fusion. Knowledge acquired from years of in vitro simulator studies on other joint replacements has highlighted the risks associated with premature wear due to unforeseen adverse clinical conditions and the effect of particulate debris on surrounding natural tissues. Having no evidence of the type and composition of the lubricating fluid that will result after spinal arthroplasty, a study on the effects of lubricant serum concentration was undertaken. The wear rate was shown to be inversely proportional to protein content of the serum over a range of 50%–3% bovine serum to water concentration

    Validation of a novel particle isolation procedure using particle doped tissue samples.

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    A novel particle isolation method for tissue samples was developed and tested using particle-doped peri-articular tissues from ovine cadavers. This enabled sensitivity of the isolation technique to be established by doping tissue samples of 0.25 g with very low particle volumes of 2.5 µm 3 per sample. Image analysis was used to verify that the method caused no changes to particle size or morphologies

    The retrieval of fingerprint friction ridge detail from elephant ivory using reduced-scale magnetic and non-magnetic powdering materials

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    An evaluation of reduced-size particle powdering methods for the recovery of usable fingermark ridge detail from elephant ivory is presented herein for the first time as a practical and cost-effective tool in forensic analysis. Of two reduced-size powder material types tested, powders with particle sizes≤40μm offered better chances of recovering ridge detail from unpolished ivory in comparison to a conventional powder material. The quality of developed ridge detail of these powders was also assessed for comparison and automated search suitability. Powder materials and the enhanced ridge detail on ivory were analysed by scanning electron microscopy and energy dispersive X-ray spectroscopy and interactions between their constituents and the ivory discussed. The effect of ageing on the quality of ridge detail recovered showed that the best quality was obtained within 1week. However, some ridge detail could still be developed up to 28days after deposition. Cyanoacrylate and fluorescently-labelled cyanoacrylate fuming of ridge detail on ivory was explored and was less effective than reduced-scale powdering in general. This research contributes to the understanding and potential application of smaller scale powdering materials for the development of ridge detail on hard, semi-porous biological material typically seized in wildlife-related crimes

    General practitioner provision of preventive child health care: analysis of routine consultation data

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    <b>Background</b> GPs contribute to preventive child health care in various ways, including provision of child health surveillance (CHS) reviews, opportunistic preventive care, and more intensive support to vulnerable children. The number of CHS reviews offered in Scotland was reduced from 2005. This study aimed to quantify GPs’ provision of different types of preventive care to pre-school children before and after the changes to the CHS system.<p></p> <b>Methods</b> GP consultation rates with children aged 0–4 years were examined for the 2½ years before and after the changes to the CHS system using routinely available data from 30 practices in Scotland. Consultations for CHS reviews; other aspects of preventive care; and all reasons were considered.<p></p> <b>Results:</b> Prior to the changes to the CHS system, GPs often contributed to CHS reviews at 6–8 weeks and 8–9 and 39–42 months. Following the changes, GP provision of the 6–8 week review continued but other reviews essentially ceased. Few additional consultations with pre-school children are recorded as involving other aspects of preventive care, and the changes to CHS have had no impact on this. In the 2½ years before and after the changes, consultations recorded as involving any form of preventive care accounted for 11% and 7.5% respectively of all consultations with children aged 0–4 years, with the decline due to reductions in CHS reviews.<p></p> <b>Conclusions:</b> Effective preventive care through the early years can help children secure good health and developmental outcomes. GPs are well placed to contribute to the provision of such care. Consultations focused on preventive care form a small minority of GPs’ contacts with pre-school children, however, particularly since the reduction in the number of CHS reviews
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