2,751 research outputs found

    Melaena with Peutz-Jeghers syndrome: a case report

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    Introduction: Peutz-Jeghers syndrome (PJS) is a rare familial disorder characterised by mucocutaneous pigmentation, gastrointestinal and extragastrointestinal hamartomatous polyps and an increased risk of malignancy. Peutz-Jeghers polyps in the bowel may result in intussusception. This complication usually manifests with abdominal pain and signs of intestinal obstruction. Case Presentation: We report the case of a 24-year-old Caucasian male who presented with melaena. Pigmentation of the buccal mucosa was noted but he was pain-free and examination of the abdomen was unremarkable. Upper gastrointestinal endoscopy revealed multiple polyps. An urgent abdominal computed tomography (CT) scan revealed multiple small bowel intussusceptions. Laparotomy was undertaken on our patient, reducing the intussusceptions and removing the polyps by enterotomies. Bowel resection was not needed. Conclusion: Melaena in PJS needs to be urgently investigated through a CT scan even in the absence of abdominal pain and when clinical examination of the abdomen shows normal findings. Although rare, the underlying cause could be intussusception, which if missed could result in grave consequences

    Driven by speculation, not by impact - the effects of plastic on fish species.

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    Plastic products have facilitated the daily lives of an exponentially increasing world population for over 70 years, whilst inadvertently creating one of the most topical environmental issues of the 21st Century: the plastic pollution crisis. Since the mid-20th Century, plastic production has expanded continuously to global production levels of over 350 million tons in 2018 (Thompson et al. 2009; Plastics Europe, 2019). Articles surrounding the presence and impacts of plastic pollution on aquatic animals including fish species have become a regular occurrence on media platforms (Kramm et al. 2018) and scientific publications (Henderson & Green, 2020); however, while iconic pictures of individual fish and other taxa with variously attached or ingested plastics might make headlines, they do not of themselves prove impacts, absolute or relative, at population levels

    Stem cell differentiation increases membrane-actin adhesion regulating cell blebability, migration and mechanics

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    This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder in order to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/K. S. is funded by an EPSRC PhD studentship. S.T. is funded by an EU Marie Curie Intra European Fellowship (GENOMICDIFF)

    Surface acoustic wave modulation of quantum cascade lasers

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    In this work, a description is given of a simulation technique employed to model the interaction between surface acoustic waves and ridge-waveguide quantum cascade lasers (QCLs). Firstly, a finite-difference time-domain (FDTD) scheme for modelling acoustic wave propagation in arbitrary semiconductor structures is outlined, and verified by comparison with experimental measurements of the frequency response of surface acoustic wave transmission between interdigitated transmitters and receivers on a bulk crystal. The model is developed further to represent the ridge-waveguide as a prominence above the surface and the active region of the laser is accounted for by a free-charge region buried within the structure. The modulation of this free charge, or carrier concentration by the propagating surface acoustic wave, is then used as an input to a rate equation model of a QCL to show how the gain will be affected. It is this control of the gain through the amplitude of the surface acoustic wave which will allow for modulation of the mid-infrared or terahertz output of the laser and hence its incorporation in many new applications

    High Abundances of Microplastic Pollution in Deep-Sea Sediments: Evidence from Antarctica and the Southern Ocean.

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    Plastic pollution in Antarctica and the Southern Ocean has been recorded in scientific literature since the 1980s; however, the presence of microplastic particles (<5 mm) is less understood. Here, we aimed to determine whether microplastic accumulation would vary among Antarctic and Southern Ocean regions through studying 30 deep-sea sediment cores. Additionally, we aimed to highlight whether microplastic accumulation was related to sample depth or the sediment characteristics within each core. Sediment cores were digested and separated using a high-density sodium polytungstate solution (SPT) and microplastic particles were identified using micro-Fourier-transform infrared spectroscopy (μFTIR). Microplastic pollution was found in 93% of the sediment cores (28/30). The mean (±SE) microplastics per gram of sediment was 1.30 ± 0.51, 1.09 ± 0.22, and 1.04 ± 0.39 MP/g, for the Antarctic Peninsula, South Sandwich Islands, and South Georgia, respectively. Microplastic fragment accumulation correlated significantly with the percentage of clay within cores, suggesting that microplastics have similar dispersion behavior to low density sediments. Although no difference in microplastic abundance was found among regions, the values were much higher in comparison to less remote ecosystems, suggesting that the Antarctic and Southern Ocean deep-sea accumulates higher numbers of microplastic pollution than previously expected

    A bayesian meta-analysis of multiple treatment comparisons of systemic regimens for advanced pancreatic cancer

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    © 2014 Chan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Background: For advanced pancreatic cancer, many regimens have been compared with gemcitabine (G) as the standard arm in randomized controlled trials. Few regimens have been directly compared with each other in randomized controlled trials and the relative efficacy and safety among them remains unclear
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