2,612 research outputs found

    Diffusion bonding of TiC or TiB reinforced Ti–6Al–4V matrix composites to conventional Ti–6Al–4V alloy

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    The diffusion bonding of conventional alloy Ti–6Al–4V (Ti-64) and composites of this alloy with 10% of TiC or TiB fabricated using blended elemental powder metallurgy was successfully carried out at 850–1000°C, with a holding time of 60 min under 0.7–1.5 MPa pressure. The metallographic and electron backscattered diffraction studies as well as the bending and microhardness tests across the bonds are presented as the evidence of joint integrity. The selected experimental parameters do not cause undesirable structural changes (degradation) in the base metals adjacent to the bond interface. Particle reinforcement at ∼10% did not appear to modify bonding parameters when compared to the unreinforced Ti-64 alloy

    Using mixed methods evaluation to assess the feasibility of online clinical training in evidence based interventions : a case study of cognitive behavioural treatment for low back pain

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    Background: Cognitive behavioural (CB) approaches are effective in the management of non-specific low back pain (LBP). We developed the CB Back Skills Training programme (BeST) and previously provided evidence of clinical and cost effectiveness in a large pragmatic trial. However, practice change is challenged by a lack of treatment guidance and training for clinicians. We aimed to explore the feasibility and acceptability of an online programme (iBeST) for providing training in a CB approach. Methods: This mixed methods study comprised an individually randomised controlled trial of 35 physiotherapists and an interview study of 8 physiotherapists. Participants were recruited from 8 National Health Service departments in England and allocated by a computer generated randomisation list to receive iBeST (n = 16) or a face-to-face workshop (n = 19). Knowledge (of a CB approach), clinical skills (unblinded assessment of CB skills in practice), self-efficacy (reported confidence in using new skills), attitudes (towards LBP management), and satisfaction were assessed after training. Engagement with iBeST was assessed with user analytics. Interviews explored acceptability and experiences with iBeST. Data sets were analysed independently and jointly interpreted. Results: Fifteen (94 %) participants in the iBeST group and 16 (84 %) participants in the workshop group provided data immediately after training. We observed similar scores on knowledge (MD (95 % CI): 0.97 (−1.33, 3.26)), and self-efficacy to deliver the majority of the programme (MD (95 % CI) 0.25 (−1.7; 0.7)). However, the workshop group showed greater reduction in biomedical attitudes to LBP management (MD (95 % CI): −7.43 (−10.97, −3.89)). Clinical skills were assessed in 5 (33 %) iBeST participants and 7 (38 %) workshop participants within 6 months of training and were similar between groups (MD (95 % CI): 0.17(−0.2; 0.54)). Interviews highlighted that while initially sceptical, participants found iBeST acceptable. A number of strategies were identified to enhance future versions of iBeST such as including more skills practice. Conclusions: Combined quantitative and qualitative data indicated that online training was an acceptable and promising method for providing training in an evidence based complex intervention. With future enhancement, the potential reach of this training method may facilitate evidence-based practice through large scale upskilling of the workforce

    Coccolithophore biodiversity controls carbonate export in the Southern Ocean

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    Southern Ocean waters are projected to undergo profound changes in their physical and chemical properties in the coming decades. Coccolithophore blooms in the Southern Ocean are thought to account for a major fraction of the global marine calcium carbonate (CaCO3) production and export to the deep sea. Therefore, changes in the composition and abundance of Southern Ocean coccolithophore populations are likely to alter the marine carbon cycle, with feedbacks to the rate of global climate change. However, the contribution of coccolithophores to CaCO3 export in the Southern Ocean is uncertain, particularly in the circumpolar subantarctic zone that represents about half of the areal extent of the Southern Ocean and where coccolithophores are most abundant. Here, we present measurements of annual CaCO3 flux and quantitatively partition them amongst coccolithophore species and heterotrophic calcifiers at two sites representative of a large portion of the subantarctic zone. We find that coccolithophores account for a major fraction of the annual CaCO3 export, with the highest contributions in waters with low algal biomass accumulations. Notably, our analysis reveals that although Emiliania huxleyi is an important vector for CaCO3 export to the deep sea, less abundant but larger species account for most of the annual coccolithophore CaCO3 flux. This observation contrasts with the generally accepted notion that high particulate inorganic carbon accumulations during the austral summer in the subantarctic Southern Ocean are mainly caused by E. huxleyi blooms. It appears likely that the climate-induced migration of oceanic fronts will initially result in the poleward expansion of large coccolithophore species increasing CaCO3 production. However, subantarctic coccolithophore populations will eventually diminish as acidification overwhelms those changes. Overall, our analysis emphasizes the need for species-centred studies to improve our ability to project future changes in phytoplankton communities and their influence on marine biogeochemical cycles.info:eu-repo/semantics/publishedVersio

    Optimising use of electronic health records to describe the presentation of rheumatoid arthritis in primary care: a strategy for developing code lists

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    Background Research using electronic health records (EHRs) relies heavily on coded clinical data. Due to variation in coding practices, it can be difficult to aggregate the codes for a condition in order to define cases. This paper describes a methodology to develop ‘indicator markers’ found in patients with early rheumatoid arthritis (RA); these are a broader range of codes which may allow a probabilistic case definition to use in cases where no diagnostic code is yet recorded. Methods We examined EHRs of 5,843 patients in the General Practice Research Database, aged ≥30y, with a first coded diagnosis of RA between 2005 and 2008. Lists of indicator markers for RA were developed initially by panels of clinicians drawing up code-lists and then modified based on scrutiny of available data. The prevalence of indicator markers, and their temporal relationship to RA codes, was examined in patients from 3y before to 14d after recorded RA diagnosis. Findings Indicator markers were common throughout EHRs of RA patients, with 83.5% having 2 or more markers. 34% of patients received a disease-specific prescription before RA was coded; 42% had a referral to rheumatology, and 63% had a test for rheumatoid factor. 65% had at least one joint symptom or sign recorded and in 44% this was at least 6-months before recorded RA diagnosis. Conclusion Indicator markers of RA may be valuable for case definition in cases which do not yet have a diagnostic code. The clinical diagnosis of RA is likely to occur some months before it is coded, shown by markers frequently occurring ≥6 months before recorded diagnosis. It is difficult to differentiate delay in diagnosis from delay in recording. Information concealed in free text may be required for the accurate identification of patients and to assess the quality of care in general practice

    Whole-Genome Sequencing of Retinoblastoma Reveals the Diversity of Rearrangements Disrupting RB1 and Uncovers a Treatment-Related Mutational Signature.

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    The development of retinoblastoma is thought to require pathological genetic changes in both alleles of the RB1 gene. However, cases exist where RB1 mutations are undetectable, suggesting alternative pathways to malignancy. We used whole-genome sequencing (WGS) and transcriptomics to investigate the landscape of sporadic retinoblastomas derived from twenty patients, sought RB1 and other driver mutations and investigated mutational signatures. At least one RB1 mutation was identified in all retinoblastomas, including new mutations in addition to those previously identified by clinical screening. Ten tumours carried structural rearrangements involving RB1 ranging from relatively simple to extremely complex rearrangement patterns, including a chromothripsis-like pattern in one tumour. Bilateral tumours obtained from one patient harboured conserved germline but divergent somatic RB1 mutations, indicating independent evolution. Mutational signature analysis showed predominance of signatures associated with cell division, an absence of ultraviolet-related DNA damage and a profound platinum-related mutational signature in a chemotherapy-exposed tumour. Most RB1 mutations are identifiable by clinical screening. However, the increased resolution and ability to detect otherwise elusive rearrangements by WGS have important repercussions on clinical management and advice on recurrence risks

    Recurrent mutation of IGF signalling genes and distinct patterns of genomic rearrangement in osteosarcoma

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    Osteosarcoma is a primary malignancy of bone that affects children and adults. Here, we present the largest sequencing study of osteosarcoma to date, comprising 112 childhood and adult tumours encompassing all major histological subtypes. A key finding of our study is the identification of mutations in insulin-like growth factor (IGF) signalling genes in 8/112 (7%) of cases. We validate this observation using fluorescence in situ hybridization (FISH) in an additional 87 osteosarcomas, with IGF1 receptor (IGF1R) amplification observed in 14% of tumours. These findings may inform patient selection in future trials of IGF1R inhibitors in osteosarcoma. Analysing patterns of mutation, we identify distinct rearrangement profiles including a process characterized by chromothripsis and amplification. This process operates recurrently at discrete genomic regions and generates driver mutations. It may represent an age-independent mutational mechanism that contributes to the development of osteosarcoma in children and adults alike

    Biologic treatment response among adults with juvenile idiopathic arthritis: results from the British Society for Rheumatology Biologics Register

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    Abstract Objective. To describe the use of and response to biologic therapies commenced in adults with JIA. Methods. Patients with arthritis onset <16 years were identified from the British Society for Rheumatology Biologics Register for rheumatoid arthritis (BSRBR-RA) and stratified into ILAR JIA subtypes. Patterns of biologic use and treatment persistence were explored, with disability levels (HAQ) and remission rates [28-Joint Disease Activity Score (DAS28)] evaluated at 6 and 12 months. Results. Arthritis with an onset of <16 years was confirmed in 225 patients and the ILAR subtype was determined in 154 (68%). Only 58 (26%) patients had a diagnosis of JIA recorded in the BSRBR-RA. The median age at biologic commencement was 31 years [interquartile range (IQR) 2339] and 76% were female. The biologic therapies were etanercept (49%), infliximab (28%), adalimumab (22%) and anakinra (1%). Fifty per cent of patients received more than one biologic during follow-up (2 agents, n = 64; 53 agents, n = 49). Treatment persistence at 1 year was 78% (95% CI 71%, 82%), falling to 42% (95% CI 34%, 49%) at 5 years. Both the HAQ and DAS28 improved significantly at 6 months, with 21% and 28% of patients in remission (DAS28 < 2.6) at 6 and 12 months, respectively. Conclusion. This study describes patterns and identifies outcomes of biologic use in a national cohort of adults with JIA. With no national guidance currently available in this area, the choice of first biologic was inconsistent, although treatment outcomes were good. These data confirm that biologic therapies are an important treatment option in adults with active JIA in adulthood

    Parsing neurobiological heterogeneity of the clinical high-risk state for psychosis: A pseudo-continuous arterial spin labelling study

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    The impact of the clinical high-risk for psychosis (CHR-P) construct is dependent on accurately predicting outcomes. Individuals with brief limited intermittent psychotic symptoms (BLIPS) have higher risk of developing a first episode of psychosis (FEP) compared to individuals with attenuated psychotic symptoms (APS). Supplementing subgroup stratification with information from candidate biomarkers based on neurobiological parameters, such as resting-state, regional cerebral blood flow (rCBF), may help refine risk estimates. Based on previous evidence, we hypothesised that individuals with BLIPS would exhibit increased rCBF compared to APS in key regions linked to dopaminergic pathways. Data from four studies were combined using ComBat (to account for between-study differences) to analyse rCBF in 150 age- and sex-matched subjects (n=30 healthy controls [HCs], n=80 APS, n=20 BLIPS and n=20 FEP). Global grey matter (GM) rCBF was examined in addition to region-of-interest (ROI) analyses in bilateral/left/right frontal cortex, hippocampus and striatum. Group differences were assessed using general linear models: i) alone; ii) with global GM rCBF as a covariate; iii) with global GM rCBF and smoking status as covariates. Significance was set at pNo significant group differences were found in global (F(3,143)=1,41, p=0.24), bilateral frontal cortex (F(3,143)=1.01, p=0.39), hippocampus (F(3,143)=0.63, p=0.60) or striatum (F(3,143)=0.52, p=0.57) rCBF. Similar null findings were observed in lateralised ROIs (p&gt;0.05). All results were robust to addition of covariates (p&gt;0.05). No significant clusters were identified in whole-brain voxel-wise analyses (p&gt;0.05FWE). Weak-to-moderate evidence was found for an absence of rCBF differences between APS and BLIPS in Bayesian ROI analyses.On this evidence, APS and BLIPS are unlikely to be neurobiologically distinct. Due to this and the weak-to-moderate evidence for the null hypothesis, future research should investigate larger samples of APS and BLIPS through collaboration across large-scale international consortia.<br/

    Patient perspectives of managing fatigue in ankylosing spondylitis, and views on potential interventions: a qualitative study

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    &lt;p&gt;Background: Fatigue is a major component of living with ankylosing spondylitis (AS), though it has been largely over-looked, and currently there are no specific agreed management strategies.&lt;/p&gt; &lt;p&gt;Methods: This qualitative exploratory study involved participants who are members of an existing population-based ankylosing spondylitis (PAS) cohort. Participants residing in South West Wales were invited to participate in a focus group to discuss; (1) effects of fatigue, (2) self-management strategies and (3) potential future interventions. The focus groups were audio-recorded and the transcripts were analysed using thematic analysis.&lt;/p&gt; &lt;p&gt;Results: Participants consisted of 3 males/4 females (group 1) and 4 males/3 females (group 2), aged between 35 and 73 years (mean age 53 years). Three main themes were identified: (1) The effects of fatigue were multi-dimensional with participants expressing feelings of being ‘drained’ (physical), ‘upset’ (emotional) and experiencing ‘low-mood’ (psychological); (2) The most commonly reported self-management strategy for fatigue was a balanced combination of activity (exercise) and rest. Medication was reluctantly taken due to side-effects and worries over dependency; (3) Participants expressed a preference for psychological therapies rather than pharmacological for managing fatigue. Information on Mindfulness-Based Stress Reduction (MBSR) was received with interest, with recommendations for delivery in a group format with the option of distance-based delivery for people who were not able to attend a group course.&lt;/p&gt; &lt;p&gt;Conclusions: Patients frequently try and manage their fatigue without any formal guidance or support. Our research indicates there is a need for future research to focus on psychological interventions to address the multi-faceted aspects of fatigue in AS.&lt;/p&gt
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