4,372 research outputs found

    A Simple PCR Method for Rapid Genotype Analysis of the TH-MYCN Transgenic Mouse

    Get PDF
    BACKGROUND: The TH-MYCN transgenic mouse is the most widely used murine model of human neuroblastoma, in which a human MYCN oncogene is targeted to neuroectodermal cells of developing mice under the influence of the rat tyrosine hydroxylase promoter. So far, homozygous transgenic mice have been identified by either Southern blot or quantitative real-time PCR. PRINCIPAL FINDINGS: To establish a simple and reliable genotyping method by conventional PCR, we confirmed the integration of the transgene in the TH-MYCN transgenic mouse by Southern blot and inverse PCR analyses. Our results showed that either five or six copies were found to be inserted in a head-to-tail tandem configuration at a single locus. The MYCN transgene/host DNA junction was sequenced and the integration site was identified at chromosome 18qE4. Finally, we succeeded in designing rapid, simple and reliable genotyping method by common PCR using primers flanking the integrated TH-MYCN transgene. CONCLUSION: We established a simple and reliable genotyping PCR method for determining the integration site of the TH-MYCN transgene that enables all possible genotypes to be distinguished within several hours. TH-MYCN mice are excellent model for human neuroblastoma study, thus our results will largely be useful for facilitating the pace of neuroblastoma study, including in the study of the tumourigenic process, and in the development of therapies to treat patients suffering from neuroblastoma

    Stabilising Lyme Regis – a strategic approach

    Get PDF
    Coastal erosion and landslides have been a constant threat to Lyme Regis in West Dorset, UK for over 250 years. By the 1980s, the frequency and scale of coastal erosion and land instability had reached a point whereby the local council realised that a change from the previous ad hoc repair and protection approach was needed to secure the long-term future of the town. An environmental improvements initiative was developed from then onwards to provide a strategic and integrated programme of coast protection and cliff stabilisation measures designed to mitigate the increasing threat of climate change, coastal erosion and landslides, while respecting the site’s unique heritage and environmental interests. This paper outlines the background and principal phases of the project that have been successfully delivered over the period 1990–2015

    Prioritise safety, optimise success! Return to rugby postpartum

    Get PDF
    Pregnancy and childbirth involve substantial physical, physiological and psychological changes. As such, postpartum rugby players should be supported and appropriately prepared to return to the demands of rugby alongside the additional demands of motherhood. This review aims to discuss specific perinatal considerations that inform a rugby player's readiness to return-to-sport postpartum and present an approach to rehabilitation. Before engaging in full rugby training and matchplay, postpartum players should have progressed through the initial phases of rehabilitation and graded sports-specific training to prepare them for the loads they will be exposed to. Additional rehabilitation considerations include minimising deconditioning during pregnancy; medical concerns; the abdominal wall; the pelvic floor; perinatal breast changes, breastfeeding and risk of contact breast injury; body mass; nutritional requirements; hormonal considerations; athlete identity and psychological considerations; joining team training; return to contact and tackle training; evaluating player load tolerance and future research, policy and surveillance needs. A whole-systems, biopsychosocial approach following an evidence informed return-to-sport framework is recommended when rehabilitating postpartum rugby players. Health and exercise professionals are encouraged to use the perinatal-specific recommendations in this review to guide the development of postpartum rehabilitation protocols and resources

    Current pain and the visual analogue scale as a predictor of quality of life in individuals with osteoporosis

    Get PDF
    Poster11th Conference of the National-Osteoporosis-Society, JUN 25-28, 2006, Harrogate, ENGLANDPosterGuy’s and St Thomas’ Charitable Foundatio

    The effect of S-substitution at the O6-guanine site on the structure and dynamics of a DNA oligomer containing a G:T mismatch

    Get PDF
    The effect of S-substitution on the O6 guanine site of a 13-mer DNA duplex containing a G:T mismatch is studied using molecular dynamics. The structure, dynamic evolution and hydration of the S-substituted duplex are compared with those of a normal duplex, a duplex with Ssubstitution on guanine, but no mismatch and a duplex with just a G:T mismatch. The S-substituted mismatch leads to cell death rather than repair. One suggestion is that the G:T mismatch recognition protein recognises the S-substituted mismatch (GS:T) as G:T. This leads to a cycle of futile repair ending in DNA breakage and cell death. We find that some structural features of the helix are similar for the duplex with the G:T mismatch and that with the S-substituted mismatch, but differ from the normal duplex, notably the helical twist. These differences arise from the change in the hydrogen-bonding pattern of the base pair. However a marked feature of the S-substituted G:T mismatch duplex is a very large opening. This showed considerable variability. It is suggested that this enlarged opening would lend support to an alternative model of cell death in which the mismatch protein attaches to thioguanine and activates downstream damage-response pathways. Attack on the sulphur by reactive oxygen species, also leading to cell death, would also be aided by the large, variable opening

    Topological Surface States Protected From Backscattering by Chiral Spin Texture

    Get PDF
    Topological insulators are a new class of insulators in which a bulk gap for electronic excitations is generated by strong spin orbit coupling. These novel materials are distinguished from ordinary insulators by the presence of gapless metallic boundary states, akin to the chiral edge modes in quantum Hall systems, but with unconventional spin textures. Recently, experiments and theoretical efforts have provided strong evidence for both two- and three-dimensional topological insulators and their novel edge and surface states in semiconductor quantum well structures and several Bi-based compounds. A key characteristic of these spin-textured boundary states is their insensitivity to spin-independent scattering, which protects them from backscattering and localization. These chiral states are potentially useful for spin-based electronics, in which long spin coherence is critical, and also for quantum computing applications, where topological protection can enable fault-tolerant information processing. Here we use a scanning tunneling microscope (STM) to visualize the gapless surface states of the three-dimensional topological insulator BiSb and to examine their scattering behavior from disorder caused by random alloying in this compound. Combining STM and angle-resolved photoemission spectroscopy, we show that despite strong atomic scale disorder, backscattering between states of opposite momentum and opposite spin is absent. Our observation of spin-selective scattering demonstrates that the chiral nature of these states protects the spin of the carriers; they therefore have the potential to be used for coherent spin transport in spintronic devices.Comment: to be appear in Nature on August 9, 200

    Gauge-theoretic invariants for topological insulators: A bridge between Berry, Wess-Zumino, and Fu-Kane-Mele

    Full text link
    We establish a connection between two recently-proposed approaches to the understanding of the geometric origin of the Fu-Kane-Mele invariant FKMZ2\mathrm{FKM} \in \mathbb{Z}_2, arising in the context of 2-dimensional time-reversal symmetric topological insulators. On the one hand, the Z2\mathbb{Z}_2 invariant can be formulated in terms of the Berry connection and the Berry curvature of the Bloch bundle of occupied states over the Brillouin torus. On the other, using techniques from the theory of bundle gerbes it is possible to provide an expression for FKM\mathrm{FKM} containing the square root of the Wess-Zumino amplitude for a certain U(N)U(N)-valued field over the Brillouin torus. We link the two formulas by showing directly the equality between the above mentioned Wess-Zumino amplitude and the Berry phase, as well as between their square roots. An essential tool of independent interest is an equivariant version of the adjoint Polyakov-Wiegmann formula for fields T2U(N)\mathbb{T}^2 \to U(N), of which we provide a proof employing only basic homotopy theory and circumventing the language of bundle gerbes.Comment: 23 pages, 1 figure. To appear in Letters in Mathematical Physic

    Critical appraisal of artificial intelligence-based prediction models for cardiovascular disease

    Get PDF
    The medical field has seen a rapid increase in the development of artificial intelligence (AI)-based prediction models. With the introduction of such AI-based prediction model tools and software in cardiovascular patient care, the cardiovascular researcher and healthcare professional are challenged to understand the opportunities as well as the limitations of the AI-based predictions. In this article, we present 12 critical questions for cardiovascular health professionals to ask when confronted with an AI-based prediction model. We aim to support medical professionals to distinguish the AI-based prediction models that can add value to patient care from the AI that does not
    corecore