1,473 research outputs found

    A Rare Presentation of Aggressive Angiomyxoma as a Cervical Polyp

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    A rare case of aggressive angiomyxoma (AAM) is reported here for its unusual presentation as a cervical polyp, in a 45‑year‑old woman. It is a soft tissue tumor. Preoperative diagnosis was uterine cervical polyp. Surgical excision was done. Histopathology examination revealed vascular, poorly circumscribed tumor mass composed of spindle cells embedded in myxoid stroma. In the reviewed literature, a single case of AAM mimicking cervical polyp has been reported. Our case may be the second rare case of AAM presenting as a cervical polyp.Keywords: Aggressive angiomyxoma, angiomyofibroblastoma, cervical polyp, superficial angiomyxom

    Biomechanics and the thermotolerance of development

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    Successful completion of development requires coordination of patterning events with morphogenetic movements. Environmental variability challenges this coordination. For example, developing organisms encounter varying environmental temperatures that can strongly influence developmental rates. We hypothesized that the mechanics of morphogenesis would have to be finely adjusted to allow for normal morphogenesis across a wide range of developmental rates. We formulated our hypothesis as a simple model incorporating time-dependent application of force to a viscoelastic tissue. This model suggested that the capacity to maintain normal morphogenesis across a range of temperatures would depend on how both tissue viscoelasticity and the forces that drive deformation vary with temperature. To test this model we investigated how the mechanical behavior of embryonic tissue (Xenopus laevis) changed with temperature; we used a combination of micropipette aspiration to measure viscoelasticity, electrically induced contractions to measure cellular force generation, and confocal microscopy to measure endogenous contractility. Contrary to expectations, the viscoelasticity of the tissues and peak contractile tension proved invariant with temperature even as rates of force generation and gastrulation movements varied three-fold. Furthermore, the relative rates of different gastrulation movements varied with temperature: the speed of blastopore closure increased more slowly with temperature than the speed of the dorsal-to-ventral progression of involution. The changes in the relative rates of different tissue movements can be explained by the viscoelastic deformation model given observed viscoelastic properties, but only if morphogenetic forces increase slowly rather than all at once. © 2014 von Dassow et al

    Extraction and sensitive detection of toxins A and B from the human pathogen Clostridium difficile in 40 seconds using microwave-accelerated metal-enhanced fluorescence.

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    Clostridium difficile is the primary cause of antibiotic associated diarrhea in humans and is a significant cause of morbidity and mortality. Thus the rapid and accurate identification of this pathogen in clinical samples, such as feces, is a key step in reducing the devastating impact of this disease. The bacterium produces two toxins, A and B, which are thought to be responsible for the majority of the pathology associated with the disease, although the relative contribution of each is currently a subject of debate. For this reason we have developed a rapid detection assay based on microwave-accelerated metal-enhanced fluorescence which is capable of detecting the presence of 10 bacteria in unprocessed human feces within 40 seconds. These promising results suggest that this prototype biosensor has the potential to be developed into a rapid, point of care, real time diagnostic assay for C. difficile

    Hybrid Mechanical Systems

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    We discuss hybrid systems in which a mechanical oscillator is coupled to another (microscopic) quantum system, such as trapped atoms or ions, solid-state spin qubits, or superconducting devices. We summarize and compare different coupling schemes and describe first experimental implementations. Hybrid mechanical systems enable new approaches to quantum control of mechanical objects, precision sensing, and quantum information processing.Comment: To cite this review, please refer to the published book chapter (see Journal-ref and DOI). This v2 corresponds to the published versio

    Influence of Nano-/Microfiller Addition on Mechanical and Morphological Performance of Kenaf/Glass Fibre-Reinforced Hybrid Composites

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    Natural-based composite’s progress as carriers has revealed many benefits in biomedicine, notably in the construction field, synthetic biology, and genetic engineering. Compared to analogous composites without nanoparticles, incorporating nanoparticles into polymeric materials improved architectural performance, physiological connections, and ecological features. The major goal of the current investigation is to determine the impact of nano-/micro-TiO2 on the mechanical characteristics of kenaf/glass/epoxy hybrids. The samples have been created using a hand layup method and a variety of filler loading and stacking sequences. The addition of nano-/microfiller significantly improved the mechanical performance of the epoxy/hybrid composite material. It was discovered that nanofiller-added composite materials fared better when composites were compared to and without microfilter-added composites. SEM was used to investigate the microstructure of the interfaces to ensure a good understanding of interfacial adherence between the reinforcement and their matrix. Compared to pure epoxy resin, the 15 wt% of microfiller additions of glass-kenaf-kenaf-glass type composites exhibit a 39.48% improvement in tensile and a 42.88% improvement in flexural. Similarly, 5 wt% nanofiller addition reveals a 44.214% improvement in tensile and a 50.50% improvement in flexural

    Kinetic modelling of competition and depletion of shared miRNAs by competing endogenous RNAs

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    Non-conding RNAs play a key role in the post-transcriptional regulation of mRNA translation and turnover in eukaryotes. miRNAs, in particular, interact with their target RNAs through protein-mediated, sequence-specific binding, giving rise to extended and highly heterogeneous miRNA-RNA interaction networks. Within such networks, competition to bind miRNAs can generate an effective positive coupling between their targets. Competing endogenous RNAs (ceRNAs) can in turn regulate each other through miRNA-mediated crosstalk. Albeit potentially weak, ceRNA interactions can occur both dynamically, affecting e.g. the regulatory clock, and at stationarity, in which case ceRNA networks as a whole can be implicated in the composition of the cell's proteome. Many features of ceRNA interactions, including the conditions under which they become significant, can be unraveled by mathematical and in silico models. We review the understanding of the ceRNA effect obtained within such frameworks, focusing on the methods employed to quantify it, its role in the processing of gene expression noise, and how network topology can determine its reach.Comment: review article, 29 pages, 7 figure

    A systematic analysis of host factors reveals a Med23-interferon-λ regulatory axis against herpes simplex virus type 1 replication

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    Herpes simplex virus type 1 (HSV-1) is a neurotropic virus causing vesicular oral or genital skin lesions, meningitis and other diseases particularly harmful in immunocompromised individuals. To comprehensively investigate the complex interaction between HSV-1 and its host we combined two genome-scale screens for host factors (HFs) involved in virus replication. A yeast two-hybrid screen for protein interactions and a RNA interference (RNAi) screen with a druggable genome small interfering RNA (siRNA) library confirmed existing and identified novel HFs which functionally influence HSV-1 infection. Bioinformatic analyses found the 358 HFs were enriched for several pathways and multi-protein complexes. Of particular interest was the identification of Med23 as a strongly anti-viral component of the largely pro-viral Mediator complex, which links specific transcription factors to RNA polymerase II. The anti-viral effect of Med23 on HSV-1 replication was confirmed in gain-of-function gene overexpression experiments, and this inhibitory effect was specific to HSV-1, as a range of other viruses including Vaccinia virus and Semliki Forest virus were unaffected by Med23 depletion. We found Med23 significantly upregulated expression of the type III interferon family (IFN-λ) at the mRNA and protein level by directly interacting with the transcription factor IRF7. The synergistic effect of Med23 and IRF7 on IFN-λ induction suggests this is the major transcription factor for IFN-λ expression. Genotypic analysis of patients suffering recurrent orofacial HSV-1 outbreaks, previously shown to be deficient in IFN-λ secretion, found a significant correlation with a single nucleotide polymorphism in the IFN-λ3 (IL28b) promoter strongly linked to Hepatitis C disease and treatment outcome. This paper describes a link between Med23 and IFN-λ, provides evidence for the crucial role of IFN-λ in HSV-1 immune control, and highlights the power of integrative genome-scale approaches to identify HFs critical for disease progression and outcome

    A survey of security issue in multi-agent systems

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    Multi-agent systems have attracted the attention of researchers because of agents' automatic, pro-active, and dynamic problem solving behaviors. Consequently, there has been a rapid development in agent technology which has enabled us to provide or receive useful and convenient services in a variety of areas such as banking, transportation, e-business, and healthcare. In many of these services, it is, however, necessary that security is guaranteed. Unless we guarantee the security services based on agent-based systems, these services will face significant deployment problems. In this paper, we survey existing work related to security in multi-agent systems, especially focused on access control and trust/reputation, and then present our analyses. We also present existing problems and discuss future research challenges. © Springer Science+Business Media B.V 2011

    Non invasive ventilation after extubation in paediatric patients: a preliminary study

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    <p>Abstract</p> <p>Background</p> <p>Non-invasive ventilation (NIV) may be useful after extubation in children. Our objective was to determine postextubation NIV characteristics and to identify risk factors of postextubation NIV failure.</p> <p>Methods</p> <p>A prospective observational study was conducted in an 8-bed pediatric intensive care unit (PICU). Following PICU protocol, NIV was applied to patients who had been mechanically ventilated for over 12 hours considered at high-risk of extubation failure -elective NIV (eNIV), immediately after extubation- or those who developed respiratory failure within 48 hours after extubation -rescue NIV (rNIV)-. Patients were categorized in subgroups according to their main underlying conditions. NIV was deemed successful when reintubation was avoided. Logistic regression analysis was performed in order to identify predictors of NIV failure.</p> <p>Results</p> <p>There were 41 episodes (rNIV in 20 episodes). Success rate was 50% in rNIV and 81% in eNIV (p = 0.037). We found significant differences in univariate analysis between success and failure groups in respiratory rate (RR) decrease at 6 hours, FiO<sub>2 </sub>at 1 hour and PO<sub>2</sub>/FiO<sub>2 </sub>ratio at 6 hours. Neurologic condition was found to be associated with NIV failure. Multiple logistic regression analysis identified no variable as independent NIV outcome predictor.</p> <p>Conclusions</p> <p>Our data suggest that postextubation NIV seems to be useful in avoiding reintubation in high-risk children when applied immediately after extubation. NIV was more likely to fail when ARF has already developed (rNIV), when RR at 6 hours did not decrease and if oxygen requirements increased. Neurologic patients seem to be at higher risk of reintubation despite NIV use.</p

    Effects of an H3R Antagonist on the Animal Model of Autism Induced by Prenatal Exposure to Valproic Acid

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    Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders primarily characterized by impaired social interaction and communication, and by restricted repetitive behaviors and interests. Ligands of histamine receptor 3 (H3R) are considered potential therapeutic agents for the treatment of different brain disorders and cognitive impairments. Considering this, the aim of the present study is to evaluate the actions of ciproxifan (CPX), an H3R antagonist, on the animal model of autism induced by prenatal exposure to valproic acid (VPA). Swiss mice were prenatally exposed to VPA on embryonic day 11 and assessed for social behavior, nociceptive threshold and repetitive behavior at 50 days of life. The treatment with CPX (3 mg/kg) or saline was administered 30 minutes before each behavioral test. The VPA group presented lower sociability index compared to VPA animals that were treated with CPX. Compared to the Control group, VPA animals presented a significantly higher nociceptive threshold, and treatment with CPX was not able to modify this parameter. In the marble burying test, the number of marbles buried by VPA animals was consistent with markedly repetitive behavior. VPA animals that received CPX buried a reduced amount of marbles. In summary, we report that an acute dose of CPX is able to attenuate sociability deficits and stereotypies present in the VPA model of autism. Our findings have the potential to help the investigations of both the molecular underpinnings of ASD and of possible treatments to ameliorate the ASD symptomatology, although more research is still necessary to corroborate and expand this initial data
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