242 research outputs found

    Optimization of Monte-Carlo calculations of the effective potential

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    We study Monte Carlo calculations of the effective potential for a scalar field theory using three techniques. One of these is a new method proposed and tested for the first time. In each case we extract the renormalised quantities of the theory. The system studied in our calculations is a one component ϕ4\phi^4 model in two dimensions. We apply these methods to both the weak and strong coupling regime. In the weak coupling regime we compare our results for the renormalised quantities with those obtained from two-loop lattice perturbation theory. Our results are verified in the strong coupling regime through comparison with the strong coupling expansion. We conclude that effective potential methods, when suitably chosen, can be accurate tools in calculations of the renormalised parameters of scalar field theories.Comment: 26 pages of LaTeX, uses psfig.sty with 6 figures. Entire manuscript available as a postscript file via WWW at http://www.physics.adelaide.edu.au/theory/papers/ADP-97-13.T250-abs.html or via anonymous ftp at ftp://bragg.physics.adelaide.edu.au/pub/theory/ADP-97-13.T250.p

    A patient with hypereosinophilic syndrome that manifested with acquired hemophilia and elevated IgG4: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Hypereosinophilic syndrome is defined as a prolonged state (more than six months) of eosinophilia (greater than 1500 cells/μL), without an apparent etiology and with end-organ damage. Hypereosinophilic syndrome can cause coagulation abnormalities. Among hypereosinophilic syndrome types, the lymphocytic variant (lymphocytic hypereosinophilic syndrome) is derived from a monoclonal proliferation of T lymphocytes. Here, we describe the case of a patient with lymphocytic hypereosinophilic syndrome who presented with a coagulation abnormality. To the best of our knowledge, this is the first such report including a detailed clinical picture and temporal cytokine profile.</p> <p>Case presentation</p> <p>A 77-year-old Japanese man presented to our facility with massive hematuria and hypereosinophilia (greater than 2600 cells/μl). His eosinophilia first appeared five years earlier when he developed femoral artery occlusion. He manifested with multiple hematomas and prolonged activated partial thromboplastin time. His IgG4 level was remarkably elevated (greater than 2000 mg/dL). Polymerase chain reaction tests of peripheral blood and bone marrow identified lymphocytic hypereosinophilic syndrome. His prolonged activated partial thromboplastin time was found to be due to acquired hemophilia. Glucocorticoids suppressed both the hypereosinophilia and coagulation abnormality. However, tapering of glucocorticoids led to a relapse of the coagulation abnormality alone, without eosinophilia. Tumor necrosis factor α, interleukin-5, and/or eotaxin-3 may have caused the hypereosinophilia, and interleukin-10 was correlated with the coagulation abnormality.</p> <p>Conclusions</p> <p>To the best of our knowledge, this is the first case in which lymphocytic hypereosinophilic syndrome and IgG4-related disease have overlapped. In addition, our patient is only the second case of hypereosinophilic disease that manifested with acquired hemophilia. Our patient relapsed with the coagulation abnormality alone, without eosinophilia. This report shows that the link between eosinophilia, IgG4, and clinical manifestations is not simple and provides useful insight into the immunopathology of hypereosinophilic syndrome and IgG4-related disease.</p

    Combination therapy with PEG-IFN-α and 5-FU inhibits HepG2 tumour cell growth in nude mice by apoptosis of p53

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    When the tumour suppressor p53 is activated by DNA damage, it stimulates the transcription of its target genes, which then induce cell cycle arrest or apoptosis. Here, we examined the role p53 plays in the antitumour effect of combination treatment with pegylated interferon (PEG-IFN)-α and 5-fluorouracil (5-FU), which has been shown to effectively treat advanced hepatocellular carcinoma (HCC). Nude mice were injected subcutaneously with cultured HepG2 cells, in which p53 is functional. They were treated a week later with PEG-IFN and/or 5-FU for 7 weeks, after which we measured and examined their tumours. Combination groups showed significantly lower tumour volumes and higher tumour cell apoptosis than the other groups. Combination treatment and PEG-IFN monotherapy also significantly elevated the p53 protein and mRNA levels in the tumour but only combination treatment increased the degree of p53 phosphorylation at serine46 and induced p53-regulated apoptosis-inducing protein 1 (p53AIP1) expression. The antitumour effects of combination treatment is due in part to the elevation by PEG-IFN of p53 protein and mRNA expression and in part to the DNA damage that is generated by 5-FU, which induces p53 serine46 phosphorylation, which in turn upregulates p53AIP1 expression

    GMO detection using a bioluminescent real time reporter (BART) of loop mediated isothermal amplification (LAMP) suitable for field use

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    <p>Abstract</p> <p>Background</p> <p>There is an increasing need for quantitative technologies suitable for molecular detection in a variety of settings for applications including food traceability and monitoring of genetically modified (GM) crops and their products through the food processing chain. Conventional molecular diagnostics utilising real-time polymerase chain reaction (RT-PCR) and fluorescence-based determination of amplification require temperature cycling and relatively complex optics. In contrast, isothermal amplification coupled to a bioluminescent output produced in real-time (BART) occurs at a constant temperature and only requires a simple light detection and integration device.</p> <p>Results</p> <p>Loop mediated isothermal amplification (LAMP) shows robustness to sample-derived inhibitors. Here we show the applicability of coupled LAMP and BART reactions (LAMP-BART) for determination of genetically modified (GM) maize target DNA at low levels of contamination (0.1-5.0% GM) using certified reference material, and compare this to RT-PCR. Results show that conventional DNA extraction methods developed for PCR may not be optimal for LAMP-BART quantification. Additionally, we demonstrate that LAMP is more tolerant to plant sample-derived inhibitors, and show this can be exploited to develop rapid extraction techniques suitable for simple field-based qualitative tests for GM status determination. We also assess the effect of total DNA assay load on LAMP-BART quantitation.</p> <p>Conclusions</p> <p>LAMP-BART is an effective and sensitive technique for GM detection with significant potential for quantification even at low levels of contamination and in samples derived from crops such as maize with a large genome size. The resilience of LAMP-BART to acidic polysaccharides makes it well suited to rapid sample preparation techniques and hence to both high throughput laboratory settings and to portable GM detection applications. The impact of the plant sample matrix and genome loading within a reaction must be controlled to ensure quantification at low target concentrations.</p

    Understanding Marine Mussel Adhesion

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    In addition to identifying the proteins that have a role in underwater adhesion by marine mussels, research efforts have focused on identifying the genes responsible for the adhesive proteins, environmental factors that may influence protein production, and strategies for producing natural adhesives similar to the native mussel adhesive proteins. The production-scale availability of recombinant mussel adhesive proteins will enable researchers to formulate adhesives that are water-impervious and ecologically safe and can bind materials ranging from glass, plastics, metals, and wood to materials, such as bone or teeth, biological organisms, and other chemicals or molecules. Unfortunately, as of yet scientists have been unable to duplicate the processes that marine mussels use to create adhesive structures. This study provides a background on adhesive proteins identified in the blue mussel, Mytilus edulis, and introduces our research interests and discusses the future for continued research related to mussel adhesion
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