Cardiovascular development: towards biomedical applicability: Regulation of cardiomyocyte differentiation of embryonic stem cells by extracellular signalling

Investigating the signalling pathways that regulate heart development is essential if stem cells are to become an effective source of cardiomyocytes that can be used for studying cardiac physiology and pharmacology and eventually developing cell-based therapies for heart repair. Here, we briefly describe current understanding of heart development in vertebrates and review the signalling pathways thought to be involved in cardiomyogenesis in multiple species. We discuss how this might be applied to stem cells currently thought to have cardiomyogenic potential by considering the factors relevant for each differentiation step from the undifferentiated cell to nascent mesoderm, cardiac progenitors and finally a fully determined cardiomyocyte. We focus particularly on how this is being applied to human embryonic stem cells and provide recent examples from both our own work and that of others

The assessment of pain in older people: UK National Guidelines

We are facing a huge increase in the older population over the next 30 years. This brings an anticipated increase in the prevalence of chronic pain and with this comes the challenge of assessment of pain in many varied settings. Our first iteration of this document was published in 2007. But there has been a proliferation of literature and research since then, so we have developed a new set of guidelines. Different patterns and sites of pain were seen in men and women. Age differences suggest that pain prevalence increased with age up to 85 years and then decreased. The available studies on barriers and attitudes to pain management point towards an adherence to bio-medically orientated beliefs about pain, concern amongst clinicians in relation to activity recommendations, and a negative orientation in general towards patients with chronic painful conditions. A multidisciplinary approach to the assessment and treatment of pain is essential, but the assessment is a complex process which is hampered by many communication issues, including cognitive ability and socio-cultural factors. Such issues are part of the UK ageing population. Structured pain education should be implemented that provides all health professionals (whether professionally or non-professionally trained) with standardised education and training in the assessment and management of pain according to level of experience. Although subjective, patient self-report is the most valid and reliable indicator of pain and it may be necessary to ask questions about pain in different ways in order to elicit a response. A number of valid and reliable self-report measures are available and can be used even when moderate dementia exists. The Numerical Rating Scale or verbal descriptors can be used with people who have mild to moderate cognitive impairment. For people with severe cognitive impairment Pain in Advanced Dementia (PAINAD) and Doloplus-2 are recommended. PAINAD and Doloplus-2 scales continue to show positive results in terms of reliability and validity. There has been no recent evaluation of the Abbey pain scale although it is widely used throughout the UK. There is a need for more research into pain assessment using the collaborative role of the multidisciplinary team in all care settings. Self-report questionnaires of function are limited in their ability to capture the fluctuations in capacity and ability. The concentration on items of relevance to the population of interest means that issues of personal relevance can be obscured. Strong associations were seen between pain and depressed mood with each being a risk factor for the other. Additionally, loneliness and social isolation were associated with an increased risk of pain. Clinicians should be cognisant that social isolation and or depressive signs and symptoms may be indicators of pre-existing pain or a predictor of future pain onset. There are a number of evidence based guidelines on pain assessment in older people with or without cognitive impairment from around the world, including Australia and Europe

Traitement du signal optimisé pour l’évaluation non linéaire non destructive des matériaux complexes et des tissus biologiques

In this thesis the possibility of nonlinear ultrasonic NDT is investigated for complex materials and biological tissues. The delayed TR-NEWS signal processing methodis developed, which is based on the TR-NEWS method. TR-NEWS is a method well-suited for materials with complex structure: it allows spatio-temporal focusing of a long ultrasonic chirp signal to the region near the receiving transducer, forming an impulse pulse. The received signal power and SNR are increased as a result.Delayed TR-NEWS allows the use of this focused wave pulse as a new basis for either the signal optimisation or, alternatively, for the detection of nonlinearity by the breakdown of linear superposition. This method is used in physical experiments and simulations. The physical experiments are made on an undamaged CFRP block and a porcine skin sample. The skin is tested in a synchronised acoustomechanical setup specially designed in the course of this thesis. In 1D pseudospectral simulations for CFRP, it is determined that while classical nonlinearity cannot probably be detected in ultrasonic NDT, it could be possible to detect nonclassical nonlinear effects such as those from cracks and microdamage.Physical experiments and 2D FEM simulations of linear, undamaged CFRP are compared for studying the delayed TR-NEWS method, its applicability in optimising the focused wave, and also for creating an interaction of waves at the focusing region with a linear superposition prediction. This suggests the possibility of detecting nonlinearities by comparing the actual signal from interaction to the linear prediction.Finally, more 2D simulations are conducted for CFRP with a single contact gap nonlinearity near the focusing region. The nonlinearity is measured by PI and delayed TR-NEWS. It is determined that delayed TR-NEWS is able to detect the defect at least as well as the PI method. It is ascertained that the PM hysteresis model could describe the nonclassical nonlinearity of damaged materials and biological tissues. Asynchronised acoustomechanical test setup is created to test such multiscale nonlinearity. The simultaneous mechanical load test and ultrasonic delayed TR-NEWS test can be used to measure the mechanical properties of skinNous proposons l’innovation «TR-NEWS retardée» comme une extension des méthodes TR-NEWS,issues de la symbiose du retournement temporel (RT) et des méthodes de spectroscopie d’ondes élastiques non linéaires (NEWS), avec pour principales applications le contrôle non destructif (CND) et l’imagerie ultrasonore médicale. Nous confirmons expérimentalement les bonnes performances des méthodes TR-NEWS pour : (i) des échantillons de composite CFRP aux propriétés dispersives ultrasonores autour de 10 MHz, favorisant ainsi la réverbérabilité de la propagation acoustique; (ii) des mesures de propriétés non classiques de la peau porcine par une instrumentation multi-échelles acousto-mécanique élaborée dans le cadre du projet PLET(Propriétés Locales Visco-Élastiques de la peau par TR-NEWS) financé par la Région Centre Val de Loire. via les simulations numériques 1D pseudo spectrales de propagations acoustiques non linéaires dans les CFRP, nous identifions et localisons les sources locales de défauts et de microendommagements. Elles valident l’identification d’un crack unique proche de la zone de focalisation. La non linéarité supposée de type contact acoustique (CAN),mesurée par «TR-NEWS retardée»et comparée aux techniques classiques d’inversion d’impulsion utilisées en imagerie médicale, permet une identification préservant la représentation temporelle de l’information. Ainsi, ce système d’instrumentation acousto-mécanique envisage la mesure de paramètres multi-échelles de non linéarité des tissus biologiques via les paramètres de Preisach-Mayergoyz (espaces PM) permettant de décrire leur vieillissement. Le chargement basse fréquence uniaxial (0.1-10Hz) synchronisé aux caractérisations ultrasonores haute fréquence (20MHz) via «TR-NEWS retardé» suggère une nouvelle classe de dispositifs dotée d’une perspective de multimodalité dédiée à l’imagerie ultrasonore non invasive des propriétés biomécaniques des organismes vivants

Does Routine Pain Assessment Result in Better Care?

BACKGROUND: Although a variety of national organizations such as the Canadian Pain Society, the American Pain Society and the Joint Commission on Accreditation of Health Care Organizations have advanced the idea that pain should be assessed on a routine basis, there is little evidence that systematic pain assessment information is used routinely by clinicians even when it is readily available

Acousto-mechanical instrumentation of multiscale hysteretic memristive properties of the skin with nonlinear time reversal imaging

International audienc

Nonlinear Time Reversal for Non Destructive Testing of complex medium : a review based on multi-physics experiments and signal processing strategies

International audienc