383 research outputs found

    A Hypervisor-Based Bus System for Usage Control

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    Data usage control is concerned with requirements on data after access has been granted. In order to enforce usage control requirements, it is necessary to track the different representations that the data may take (among others, file, window content, network packet). These representations exist at different layers of abstraction. As a consequence, in order to enforce usage control requirements, multiple data flow tracking and usage control enforcement monitors must exist, one at each layer. If a new representation is created at some layer of abstraction, e.g., if a cache file is created for a picture after downloading it with a browser, then the initiating layer (in the example, the browser) must notify the layer at which the new representation is created (in the example, the operating system). We present a bus system for system-wide usage control that, for security and performance reasons, is implemented in a hypervisor. We evaluate its security and performance

    Porcine-derived collagen peptides promote re-epithelialisation through activation of integrin signalling

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    \ua9 2024 The Authors. Wound Repair and Regeneration published by Wiley Periodicals LLC on behalf of The Wound Healing Society.Chronic non-healing cutaneous wounds represent a major burden to patients and healthcare providers worldwide, emphasising the continued unmet need for credible and efficacious therapeutic approaches for wound healing. We have recently shown the potential for collagen peptides to promote proliferation and migration during cutaneous wound healing. In the present study, we demonstrate that the application of porcine-derived collagen peptides significantly increases keratinocyte and dermal fibroblast expression of integrin α2β1 and activation of an extracellular signal-related kinase (ERK)-focal adhesion kinase (FAK) signalling cascade during wound closure in vitro. SiRNA-mediated knockdown of integrin β1 impaired porcine-derived collagen peptide-induced wound closure and activation of ERK-FAK signalling in keratinocytes but did not impair ERK or FAK signalling in dermal fibroblasts, implying the activation of differing downstream signalling pathways. Studies in ex vivo human 3D skin equivalents subjected to punch biopsy-induced wounding confirmed the ability of porcine-derived collagen peptides to promote wound closure by enhancing re-epithelialisation. Collectively, these data highlight the translational and clinical potential for porcine-derived collagen peptides as a viable therapeutic approach to promote re-epithelialisation of superficial cutaneous wounds

    Predictive indicators for revisional surgery in nasal reconstruction after Mohs surgery

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    Background: Reconstruction of nasal lesions is complex due to the topography, mobile free margins and borders of anatomical subunits. Reconstructive challenges can lead to multiple revisional surgeries to achieve the final aesthetic result. This study aimed to evaluate risk factors and predictors of revisional surgery in patients undergoing reconstruction after Mohs micrographic surgery for nasal tumours. Methods: This was a prospective cohort study from April 2, 2008 to February 26, 2019. The study population included all consecutive patients who underwent Mohs micrographic surgery for nasal skin cancer. Resection and reconstruction of nasal skin cancer was performed by the Mohs team. Results: A total of 988 cases met our study inclusion criteria with 64 (6.5%) cases requiring unplanned surgical revision. Revision rates were highest in the ala (9.0%, p < 0.05) and complex anatomical subunits (16.7%, p < 0.0001). In contrast, revision rates for dorsum lesions were lowest (1.8%, p < 0.001). In terms of reconstructive modalities, local flaps resulted in significantly higher rates of revision when compared to grafts (relative risk, 2.37; 95% CI, 1.15–5.0; p < 0.01). In terms of histological diagnosis, squamous cell carcinoma had significantly higher revision rates when compared to basal cell carcinoma (p < 0.05). Conclusions: To our knowledge, this is the first study to report the risk factors and predictors of revision surgery in patients undergoing MMS for nasal tumours. This study highlights that the reconstructive modality utilised affects the functional and cosmetic outcome of MMS. We note that ala complex subunit lesions, squamous cell carcinoma and flap reconstruction were associated with an increased risk of revision after Mohs reconstruction of nasal lesions. Level of evidence: Level III, risk/prognostic; therapeutic study. Trial registration number: (Ref: PLA-19-20_A03) 04/02/2020

    Cellular Therapy for Wounds: Applications of Mesenchymal Stem Cells in Wound Healing

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    Despite progress in wound treatment including gene therapy, biological dresses and engineered skin equivalents, present treatment options for chronic wounds are restricted and not always effective. For example, inability to get consistent product from the introduced gene, biological covers may give rise to hypoxic conditions and engineered skin models are limited by their construction from substances which are hard to be degraded, and do not always result in complete replication into normal uninjured skin. A growing body of evidence suggests mesenchymal stem cells (MSCs), and their secreted growth factors and microvesicles, may potentiate the wound‐healing process and as such their addition to novel wound‐healing treatments may improve the efficacy of current therapeutic strategies. Recent studies report the ability of bone marrow‐derived MSCs (BM‐MSCs) to migrate and differentiate into skin cells in vivo

    Analysis of metal oxide varistor arresters for protection of multiconductor transmission lines using unconditionally-stable Crank-Nicolson FDTD

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    Surge arresters may represent an efficient choice for limiting lightning surge effects, significantly reducing the outage rate of power lines. The present work firstly presents an efficient numerical approach suitable for insulation coordination studies based on an implicit Crank-Nicolson finite difference time domain method; then, the IEEE recommended surge arrester model is reviewed and implemented by means of a local implicit scheme, based on a set of non-linear equations, that are recast in a suitable form for efficient solution. The model is proven to ensure robustness and second-order accuracy. The implementation of the arrester model in the implicit Crank-Nicolson scheme represents the added value brought by the present study. Indeed, its preserved stability for larger time steps allows reducing running time by more than 60% compared to the well-known finite difference time domain method based on the explicit leap-frog scheme. The reduced computation time allows faster repeated solutions, which need to be looked for on assessing the lightning performance (randomly changing, parameters such as peak current, rise time, tail time, location of the vertical leader channel, phase conductor voltages, footing resistance, insulator strength, etc. would need to be changed thousands of times)

    Behavioral Impact of the Regulation of the Brain 2-Oxoglutarate Dehydrogenase Complex by Synthetic Phosphonate Analog of 2-Oxoglutarate: Implications into the Role of the Complex in Neurodegenerative Diseases

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    Decreased activity of the mitochondrial 2-oxoglutarate dehydrogenase complex (OGDHC) in brain accompanies neurodegenerative diseases. To reveal molecular mechanisms of this association, we treated rats with a specific inhibitor of OGDHC, succinyl phosphonate, or exposed them to hypoxic stress. In males treated with succinyl phosphonate and in pregnancy-sensitized females experiencing acute hypobaric hypoxia, we revealed upregulation of brain OGDHC (within 24 hours), with the activity increase presumably representing the compensatory response of brain to the OGDHC inhibition. This up-regulation of brain OGDHC was accompanied by an increase in exploratory activity and a decrease in anxiety of the experimental animals. Remarkably, the hypoxia-induced elevation of brain OGDHC and most of the associated behavioral changes were abrogated by succinyl phosphonate. The antagonistic action of hypoxia and succinyl phosphonate demonstrates potential therapeutic significance of the OGDHC regulation by the phosphonate analogs of 2-oxoglutarate

    Technology-delivered undergraduate medical education involving patients and carers: A rapid systematic review

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    Background: Involving patients and carers in medical education centralises their voice in healthcare and supports students to develop key professional and person-centred skills. Medical schools are increasingly using technology to deliver educational activities. No review currently exists to establish the variety of technologies and their uses in undergraduate medical education when patients and/or carers are involved. / Methods: Ovid MEDLINE, Ovid EMBASE and medRxiv were searched in October 2020 and reference lists of key articles were hand searched. Eligible studies reported technology-assisted education, in any setting, involving authentic patients and/or carers. Studies in foreign languages, or describing actors or non-authentic patients were excluded. Study quality was assessed using the Mixed Methods Appraisal Tool (MMAT). Levels of patient involvement were assessed using Towle et al (2010) taxonomy. / Results: Twenty studies were included. The majority involved patients and/or carers via pre-recorded videos or online scenarios, with no student-interaction. Four studies evaluated remote consultations using telehealth technology, involving real-time interactions with authentic patients. Technology-supported teaching sessions involving patients and/or carers were found to be acceptable to students, educationally valuable (to students and educators), and enhanced student engagement, patient-centred attitudes, knowledge of specific patient groups, and communication and clinical skills. Two studies describing real-time remote interactions with authentic patients indicated potential barriers for students (reduced ability to build relationship with patients and examine them), educators (reduced ability to build rapport with students) and patients (issues with using or accessing telehealth). / Conclusions: No studies directly measured the perspective of patients or carers involved in technology-delivered medical education. Future research should establish barriers and facilitators to patients and carers taking up a role in medical students education when technology is used, and evaluate PPI activities at Levels 3 and above as described by Towle et al taxonomy

    Differential effects of retinoic acid isomers on the expression of nuclear receptor co-regulators in neuroblastoma

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    AbstractRetinoic acid modulates growth and induces differentiation and apoptosis of neuroblastoma cells in vitro, with the all-trans and 9-cis isomers having different biological properties. Transcriptional activation in response to retinoic acid isomers is mediated by retinoic acid receptors and retinoid X receptors. The differential expression of co-activators and co-repressors which preferentially interact with retinoic acid receptors or retinoid X receptors may be a mechanism leading to different cellular responses to 9-cis and all-trans retinoic acid. To test this hypothesis, we have studied the expression of the nuclear receptor co-regulators TIF1α, TIF1β, SUG1 and SMRT in the N-type and S-type neuroblastoma cell lines SH SY 5Y and SH S EP. Transcripts for all four co-regulators were expressed in these neuroblastoma cells. The expression of TIF1α, TIF1β and SUG1 did not change in response to retinoic acid; however, SMRT was induced in both neuroblastoma cell lines, but particularly by all-trans retinoic acid in SH S EP cells. An additional co-activator, Trip3, was isolated by differential mRNA display and shown to be preferentially induced by 9-cis retinoic acid in SH SY 5Y and SH S EP cells. These data suggest that retinoic acid isomer-specific induction of nuclear receptor co-regulators may determine, in part, the differential biological effects of retinoic acid isomers

    Unpacking the complexity of the UK plastic packaging value chain: A stakeholder perspective

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    The pace to achieving a sustainable plastics economy remains noticeably slow. This could be due to a lack of understanding of the role and importance of stakeholder dynamics in the plastic packaging system. Therefore, this study aims to unpack and assess the role of stakeholders in improving the plastics recycling rate and circularity in the UK, using polyethylene terephthalate (PET) drinks bottles value chain as a case study. Via the theoretical lens of stakeholder theory the study identifies and groups the stakeholders in the PET drinks bottles value chain, and tries to make sense of, and analyse, their complex interactions via the use of the Complex Value Optimisation for Resource Recovery (CVORR) systems thinking approach. This integrated approach reveals, that even though external stakeholders (e.g. NGOs, trade associations) engage with internal stakeholders (e.g. suppliers, consumers, investors), and vice versa, at different levels and scales in promoting the circularity in the PET drink bottles value chain, there is a strong drive in incentivising the production and consumption processes. This is driven by the significant lobbying power of internal stakeholders operating upstream of the PET bottles value chain (i.e. producers and brand owners), that is supported by financial institutions, and which, strongly influences national and local government policies and decision-making processes. Meanwhile, the waste management processes are short-sighted, being unable to gain improved momentum and increase the PET bottles recycling rates. This dynamic conceals, and somewhat retains, the prevailing resistance in removing the infrastructural, regulatory and technological lock-ins. A collaboration between internal and external stakeholders is paramount to sustainably managing PET drinks bottles in the UK and achieving a transition to a sustainable circular plastics economy. Creating a level playing field and fostering a closer collaboration between all stakeholders involved in the system can aid the development of new value networks, and support new policy interventions that can improve circularity in the plastic packaging sector
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