A novel numerical method to predict the transient track geometry and thermomechanical effects through in-situ modification of the process parameters in Direct Energy Deposition

© 2019 Elsevier B.V. Direct Energy Deposition (DED) is being widely used to repair damaged components to increase service life and economical operation. Process parameters including laser power, traverse speed and the mass flowrate of the feedstock material may be adapted in-situ. This allows bespoke repair strategies to be devised to match the variability in the condition of the parts supplied that require repair; however, there are limited modelling techniques that allow the adaptive control within the DED process to be represented. In this study, a novel modelling strategy is presented which allows the DED process to be modelled in a transient state. This allows varying process parameters to be included in the model, to predict the transient track geometry and the associated thermomechanical effects of the process. Here, a single-track deposition of IN718 with a varying cross section has been modelled utilising the proposed approach. The modelling methodology was validated with a corresponding experimental study on a deposition made using a Nd:YAG laser source with a coaxial nozzle. An in-situ modification was generated by variation of the laser power. The track profile was compared against focus variation microscopy images and the thermomechanical portion of the model was validated through in-situ temperature measurements, micrographs and residual stress, obtained from neutron diffraction measurements. A good agreement between the predicted and experimental findings were observed. The track height and width were predicted with a maximum error of 6.5% and 7.6% respectively. The peak temperature and residual stress were predicted within 6.2% and 11.4% respectively. Overall, the modelling method presented will allow complex and bespoke multi parameter repair strategies to be rapidly developed

The development and validation of an outcome measure for spiritual healing: A mixed methods study

Background: Spiritual healing, probably the oldest documented paramedical intervention, is a neglected area of research. In order to conduct further research into the effects of healing, a valid and reliable outcome measure is needed that captures the experience of individuals receiving healing (healees) and is not burdensome to complete. We aimed to develop such a measure. Methods: A mixed methods design was used. Focus groups and cognitive interviews were used to generate and refine questionnaire items grounded in the experiences and language of healees (Study 1). The resulting questionnaire was tested and its formal psychometric properties were evaluated (Study 2). Participants were recruited from a spiritual healing sanctuary and via individual healers (including registered spiritual healers, Reiki practitioners, healers affiliated with churches). Results: In Study 1, 24 participants took part in 7 focus groups and 6 cognitive interviews. 29 common effects were identified and grouped into 7 discrete dimensions that appeared to characterize potentially sustainable effects reported by participants following their experiences of spiritual healing. In Study 2, 393 participants returned completed baseline questionnaires, 243 of whom completed the questionnaire again 1–6 weeks later. Exploratory factor analysis generated 5 subscales, based on 20 of the items: outlook, energy, health, relationships and emotional balance. These subscales demonstrated acceptable internal consistency, convergent validity and test-retest reliability. Three of the subscales and the whole questionnaire demonstrated good sensitivity to change. Conclusions: We have produced a psychometrically sound healing impact questionnaire that is acceptable to healees, healers and researchers for use in future evaluations of spiritual healing.<br/

Progenitor Cell Therapy for the Treatment of Central Nervous System Injury: A Review of the State of Current Clinical Trials

Recent preclinical work investigating the role of progenitor cell therapies for central nervous system (CNS) injuries has shown potential neuroprotection in the setting of traumatic brain injury (TBI), spinal cord injury (SCI), and ischemic stroke. Mechanisms currently under investigation include engraftment and transdifferentiation, modulation of the locoregional inflammatory milieu, and modulation of the systemic immunologic/inflammatory response. While the exact mechanism of action remains controversial, the growing amount of preclinical data demonstrating the potential benefit associated with progenitor cell therapy for neurological injury warrants the development of well-controlled clinical trials to investigate therapeutic safety and efficacy. In this paper, we review the currently active or recently completed clinical trials investigating the safety and potential efficacy of bone marrow-derived progenitor cell therapies for the treatment of TBI, SCI, and ischemic stroke. Our review of the literature shows that while the preliminary clinical trials reviewed in this paper offer novel data supporting the potential efficacy of stem/progenitor cell therapies for CNS injury, a great deal of additional work is needed to ensure the safety, efficacy, and mechanisms of progenitor cell therapy prior to widespread clinical trials

Exploring the spectral diversity of low-redshift Type Ia supernovae using the Palomar Transient Factory

We present an investigation of the optical spectra of 264 low-redshift (z < 0.2) Type Ia supernovae (SNe Ia) discovered by the Palomar Transient Factory, an untargeted transient survey. We focus on velocity and pseudo-equivalent width measurements of the Si II 4130, 5972, and 6355 A lines, as well those of the Ca II near-infrared (NIR) triplet, up to +5 days relative to the SN B-band maximum light. We find that a high-velocity component of the Ca II NIR triplet is needed to explain the spectrum in ~95 per cent of SNe Ia observed before -5 days, decreasing to ~80 per cent at maximum. The average velocity of the Ca II high-velocity component is ~8500 km/s higher than the photospheric component. We confirm previous results that SNe Ia around maximum light with a larger contribution from the high-velocity component relative to the photospheric component in their Ca II NIR feature have, on average, broader light curves and lower Ca II NIR photospheric velocities. We find that these relations are driven by both a stronger high-velocity component and a weaker contribution from the photospheric Ca II NIR component in broader light curve SNe Ia. We identify the presence of C II in very-early-time SN Ia spectra (before -10 days), finding that >40 per cent of SNe Ia observed at these phases show signs of unburnt material in their spectra, and that C II features are more likely to be found in SNe Ia having narrower light curves.Comment: 18 page, 10 figures, accepted for publication in MNRA

Metamorphosis in the Cirripede Crustacean Balanus amphitrite

Stalked and acorn barnacles (Cirripedia Thoracica) have a complex life cycle that includes a free-swimming nauplius larva, a cypris larva and a permanently attached sessile juvenile and adult barnacle. The barnacle cyprid is among the most highly specialized of marine invertebrate larvae and its settlement biology has been intensively studied. By contrast, surprisingly few papers have dealt with the critical series of metamorphic events from cementation of the cyprid to the substratum until the appearance of a suspension feeding juvenile. This metamorphosis is both ontogenetically complex and critical to the survival of the barnacle. Here we use video microscopy to present a timeline and description of morphological events from settled cyprid to juvenile barnacle in the model species Balanus amphitrite, representing an important step towards both a broader understanding of the settlement ecology of this species and a platform for studying the factors that control its metamorphosis. Metamorphosis in B. amphitrite involves a complex sequence of events: cementation, epidermis separation from the cypris cuticle, degeneration of cypris musculature, rotation of the thorax inside the mantle cavity, building of the juvenile musculature, contraction of antennular muscles, raising of the body, shedding of the cypris cuticle, shell plate and basis formation and, possibly, a further moult to become a suspension feeding barnacle. We compare these events with developmental information from other barnacle species and discuss them in the framework of barnacle settlement ecology

Liver-Targeting of Interferon-Alpha with Tissue-Specific Domain Antibodies

PMCID: PMC3581439This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Changes in gene expression in space and time orchestrate environmentally mediated shaping of root architecture

Shaping of root architecture is a quintessential developmental response that involves the concerted action of many different cell types, is highly dynamic and underpins root plasticity. To determine to what extent the environmental regulation of lateral root development is a product of cell type preferential activities, we tracked transcriptomic responses to two different treatments that both change root development in Arabidopsis thaliana, at an unprecedented level of temporal detail. We found that individual transcripts are expressed with a very high degree of temporal and spatial specificity, yet biological processes are commonly regulated, in a mechanism we term response nonredundancy. Using causative gene network inference to compare the genes regulated in different cell types and during responses to nitrogen and a biotic interaction we found that common transcriptional modules often regulate the same gene families, but control different individual members of these families, specific to response and cell type. This reinforces that the activity of a gene cannot be defined simply as molecular function; rather, it is a consequence of spatial location, expression timing and environmental responsiveness

Human Skeletal Stem Cell Response to Multiscale Topography Induced by Large Area Electron Beam Irradiation Surface Treatment

The healthcare socio-economic environment is irreversibly changing as a consequence of an increasing aging population, consequent functional impairment, and patient quality of life expectations. The increasing complexity of ensuing clinical scenarios compels a critical search for novel musculoskeletal regenerative and replacement strategies. While joint arthroplasty is a highly effective treatment for arthritis and osteoporosis, further innovation and refinement of uncemented implants are essential in order to improve implant integration and reduce implant revision rate. This is critical given financial restraints and the drive to improve cost-effectiveness and quality of life outcomes. Multi-scale modulation of implant surfaces, offers an innovative approach to enhancement in implant performance. In the current study, we have examined the potential of large area electron beam melting to alter the surface nanotopography in titanium alloy (Ti6Al4V). We evaluated the in vitro osteogenic response of human skeletal stem cells to the resultant nanotopography, providing evidence of the relationship between the biological response, particularly Collagen type I and Osteocalcin gene activation, and surface nanoroughness. The current studies demonstrate osteogenic gene induction and morphological cell changes to be significantly enhanced on a topography Ra of ~40 nm with clinical implications therein for implant surface treatment and generation

Frailty, prefrailty and employment outcomes in Health and Employment After Fifty (HEAF) Study

Objectives Demographic changes are requiring people to work longer. No previous studies, however, have focused on whether the ‘frailty’ phenotype (which predicts adverse events in the elderly) is associated with employment difficulties. To provide information, we assessed associations in the Health and Employment After Fifty Study, a population-based cohort of 50–65-year olds.Methods Subjects, who were recruited from 24 English general practices, completed a baseline questionnaire on ‘prefrailty’ and ‘frailty’ (adapted Fried criteria) and several work outcomes, including health-related job loss (HRJL), prolonged sickness absence (&gt;20 days vs less, past 12 months), having to cut down substantially at work and difficulty coping with work's demands. Associations were assessed using logistic regression and population attributable fractions (PAFs) were calculated.Results In all, 3.9% of 8095 respondents were classed as ‘frail’ and 31.6% as ‘prefrail’. Three-quarters of the former were not in work, while 60% had left their last job on health grounds (OR for HRJL vs non-frail subjects, 30.0 (95% CI 23.0 to 39.2)). Among those in work, ORs for prolonged sickness absence, cutting down substantially at work and struggling with work's physical demands ranged from 10.7 to 17.2. The PAF for HRJL when any frailty marker was present was 51.8% and that for prolonged sickness absence was 32.5%. Associations were strongest with slow reported walking speed. Several associations were stronger in manual workers than in managers.Conclusions Fried frailty symptoms are not uncommon in mid-life and are strongly linked with economically important adverse employment outcomes. Frailty could represent an important target for prevention.</p