Discrete population balance models of random agglomeration and cleavage in polymer pyrolysis

The processes of random agglomeration and cleavage (both of which are important for the development of new models of polymer combustion, but are also applicable in a wide range of fields including atmospheric physics, radiation modelling and astrophysics) are analysed using population balance methods. The evolution of a discrete distribution of particles is considered within this framework, resulting in a set of ordinary differential equations for the individual particle concentrations. Exact solutions for these equations are derived, together with moment generating functions. Application of the discrete Laplace transform (analogous to the Z-transform) is found to be effective in these problems, providing both exact solutions for particle concentrations and moment generating functions. The combined agglomeration-cleavage problem is also considered. Unfortunately, it has been impossible to find an exact solution for the full problem, but a stable steady state has been identified and computed

Cancer Survivors’ Social Context in the Return to Work Process:Narrative Accounts of Social Support and Social Comparison Information

Purpose: Returning to work is a process that is intertwined with the social aspects of one’s life, which can influence the way in which that person manages their return to work and also determines the support available to them. This study aimed to explore cancer patients’ perceptions of the role of their social context in relation to returning to work following treatment. Methods: Twenty-three patients who had received a diagnosis of either urological, breast, gynaecological, or bowel cancer participated in semi-structured interviews examining general perceptions of cancer, work values and perceptions of the potential impact of their cancer diagnosis and treatment on work. Interviews were analysed using the iterative process of Framework Analysis. Results: Two superordinate themes emerged as influential in the return to work process: Social support as a facilitator of return to work (e.g. co-workers’ support and support outside of the workplace) and Social comparison as an appraisal of readiness to return to work (e.g. comparisons with other cancer patients, colleagues, and employees in other organisations or professions). Conclusions: Two functions of the social context of returning to work after cancer were apparent in the participants’ narrative: the importance of social support as a facilitator of returning to work and the utilisation of social comparison information in order to appraise one’s readiness to return to work. The role of social context in returning to work has largely been absent from the research literature to date. The findings of this study suggest that social support and social comparison mechanisms may have a significant impact on an individual’s successful return to the workplace

Prevalence of BRCA1 and BRCA2 mutations in unselected breast cancer patients from Greece

<p>Abstract</p> <p>Background</p> <p>Inheritance of a mutation in either <it>BRCA1 </it>or <it>BRCA2 </it>accounts for approximately 5% of all breast cancer cases, but varies by country. Investigations into the contribution of <it>BRCA </it>mutations to breast cancer incidence in Greece have been, for the most part, limited by small sample sizes and by the use of cases selected for their family history of cancer. The aim of the current study was to estimate <it>BRCA </it>mutation frequencies in breast cancer patients unselected for family history.</p> <p>Methods</p> <p>To do so, we enrolled 127 unselected women with breast cancer from the Alexandra Hospital in Athens, Greece, a large public hospital in the city. Mutations in <it>BRCA1 </it>and <it>BRCA2 </it>were detected using a combination of techniques and were confirmed by direct sequencing. Two large genomic deletions were sought using mutation-specific assays. A detailed family history of cancer was obtained from each patient.</p> <p>Results</p> <p>We were able to successfully complete testing on samples from 127 women. Among these, six mutations were identified (four in <it>BRCA1 </it>and two in <it>BRCA2</it>) representing 4.7% of the total or 9.5% of cases diagnosed before age forty. None of the mutation carriers had a family history of breast or ovarian cancer. Three of the four <it>BRCA1 </it>mutations were in exon 20: two were a G5331A mutation and the third was a 3.2 kb deletion. The fourth <it>BRCA1 </it>mutation was the 3819delGTAAA in exon 11. The two <it>BRCA2 </it>mutations were in exon 11 (3782del10 and 4512insT).</p> <p>Conclusions</p> <p>The G5331A mutation in <it>BRCA1 </it>appears to be a founder mutation in the Greek population.</p

Temporomandibular joint arthritis: Possible etiologic factors and arthritis classification

Aim: The aim of this paper was to classify the signs of the various types of arthritis that are related to the TMJ according to the etiologic factors. TMJ Arthritis classification is presented according to the levels of inflammation, in order to summarize current knowledge about the inflammatory theory, with emphasis on recent research on pathophysiology and radiographic differential diagnosis of TMJ arthritis types: Osteoarthritis (low- inflammatory arthritic condition), results from increased pressure on a particular joint or fragility of the cartilage matrix and represents a destructive process by which the bony articular surfaces of the condyle and fossa become altered. Osteoarthrosis (non-inflammatory arthritic condition) is an adaptive stage, involving morphologic changes of the articular structures, not associated with significant alterations in the mechanical joint function. Altered articular surfaces of the TMJ may be considered as normal adaptive responses to increased loading, rather than pathological degenerative changes. Polyarthritis or polyarticular arthritis (high-inflammatory arthritic conditions), present similar symptoms and clinical findings as osteoarthritis but have different causes. The classic type of high-inflammatory arthritis is rheumatoid arthritis. Conclusion: The clinician must be aware of the various systemic conditions that may affect the TMJ and the stomatognathic system as a whole. In this way the proposed dental treatment plan can and should be adjusted to the needs of the patient taking under consideration the manifestations of the disease in the stomatognathic system. © 2020 ARIESDUE

“Trust people you’ve never worked with” – A social network visualization of teamwork, cohesion, social support, and mental health in NHS Covid personnel

Background: The unprecedented rapid re-deployment of healthcare workers from different care pathways into newly created and fluid COVID-19 teams provides a unique opportunity to examine the interaction of many of the established non-technical factors for successful delivery of clinical care and teamwork in healthcare settings. This research paper therefore aims to address these gaps by qualitatively exploring the impact of COVID work throughout the pandemic on permanent and deployed personnel’s experiences, their ability to effectively work together, and the effect of social dynamics (e.g., cohesion, social support) on teamwork and mental health. Methods: Seventy-five interviews were conducted across the UK between March and December 2021 during wave 2 and 3 of COVID-19 with 75 healthcare workers who were either permanent staff on Intensive Care/High Dependency Units used as COVID wards, had been rapidly deployed to such a ward, or had managed such wards. Work Life Balance was measured using the WLB Scale. Interview transcripts were qualitatively coded and thematic codes were compared using network graph modeling. Results: Using thematic network analysis, four overarching thematic clusters were found, (1) teamwork, (2) organizational support and management, (3) cohesion and social support, and (4) psychological strain. The study has three main findings. First, the importance of social factors for teamwork and mental health, whereby team identity may influence perceptions of preparedness, collaboration and communication, and impact on the collective appraisal of stressful events and work stressors. Secondly, it demonstrates the positive and negative impact of professional roles and skills on the development of teamwork and team identity. Lastly the study identifies the more pronounced negative impact of COVID work on deployed personnel’s workload, mental health, and career intentions, exacerbated by reduced levels of social support during, and after, their deployment. Conclusion: The thematic network analysis was able to highlight that many of the traditional factors associated with the successful delivery of patient care were impeded by pandemic constraints, markedly influencing personnel’s ability to work together and cope with pandemic work stressors. In this environment teamwork, delivery of care and staff well-being appear to depend on relational and organizational context, social group membership, and psycho-social skills related to managing team identity. While results hold lessons for personnel selection, training, co-location, and organizational support during and after a pandemic, further research is needed into the differential impact of pandemic deployment on HCWs mental health and teamwork

Contribution of BRCA1 germ-line mutations to breast cancer in Greece: a hospital-based study of 987 unselected breast cancer cases

Background:In most Western populations, 5-10% of all breast cancer cases can be attributed to major genetic factors such as predisposing mutations in BRCA1 and BRCA2, with early-onset cases generally considered as an indicator of genetic susceptibility. Specific BRCA1 and BRCA2 mutations or different mutation frequencies have been identified in specific populations and ethnic groups. Previous studies in Greek breast and/or ovarian cancer patients with family history have shown that four specific BRCA1 mutations, c.5266dupC, G1738R, and two large genomic rearrangements involving deletions of exons 20 and 24, have a prominent function in the population&apos;s BRCA1 and BRCA2 mutation spectrum.Methods:To estimate the frequency of the above mutations in unselected Greek breast cancer women, we screened 987 unselected cases independently of their family history, collected from major Greek hospitals.RESULTS: Of the 987 patients, 26 (2.6%) were found to carry one of the above mutations in the BRCA1 gene: 13 carried the c.5266dupC mutation (1.3%), 6 carried the exon 24 deletion (0.6%), 3 carried the exon 20 deletion (0.3%), and 4 carried the G1738R mutation (0.4%). Among 140 patients with early-onset breast cancer (40 years), 14 carried one of the four mutations (10.0%).Conclusion:These results suggest that a low-cost genetic screening for only the four prominent BRCA1 mutations may be advisable to all early-onset breast cancer patients of Greek origin. © 2009 Cancer Research