77 research outputs found

    Liquid phase diffusion growth of SiGe single crystals under magnetic fields

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    The manuscript presents the results of a combined experimental and modeling study on the Liquid Phase Diffusion (LPD) growth of single crystal SixGe1-x on Germanium with and with the application of magnetic fields. Although the LPD process is mainly diffusion driven through out the growth period, strong natural thermosolutal convection occurs in the first five hours of growth, and the growth interface is concave to the melt. Applied rotating and static magnetic fields were considered to examine the growth and silicon dissolution processes in the LPD system. Results show that the application of a combined applied magnetic is beneficial

    Mathematical modeling of the dissolution process of silicon into germanium melt

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    Numerical simulations were carried out to study the thermosolutal and flow structures observed in the dissolution experiments of silicon into a germanium melt. The dissolution experiments utilized a material configuration similar to that used in the Liquid Phase Diffusion (LPD) and Melt-Replenishment Czochralski (Cz) crystal growth systems. In the present model, the computational domain was assumed axisymmetric. Governing equations of the liquid phase (Si-Ge mixture), namely the equations of conservation of mass, momentum balance, energy balance, and solute (species) transport balance were solved using the Stabilized Finite Element Methods (ST-GLS for fluid flow, SUPG for heat and solute transport). Measured concentration profiles and dissolution height from the samples processed with and without the application of magnetic field show that the amount of silicon transported into the melt is slightly higher in the samples processed under magnetic field, and there is a difference in dissolution interface shape indicating a change in the flow structure during the dissolution process. The present mathematical model predicts this difference in the flow structure. In the absence of magnetic field, a flat stable interface is observed. In the presence of an applied field, however, the dissolution interface remains flat in the center but curves back into the source material near the edge of the wall. This indicates a far higher dissolution rate at the edge of the silicon source.We gratefully acknowledge the financial support provided by the Canadian Space Agency (CSA), Canada Research Chairs (CRC) Program, and the Natural Sciences and Engineering Research Council (NSERC) of Canada.Publisher's Versio

    Self-management strategies to consider to combat endometriosis symptoms during the COVID-19 pandemic

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    The care of patients with endometriosis has been complicated by the coronavirus disease 2019 (COVID-19) pandemic. Medical and allied healthcare appointments and surgeries are being temporarily postponed. Mandatory self-isolation has created new obstacles for individuals with endometriosis seeking pain relief and improvement in their quality of life. Anxieties may be heightened by concerns over whether endometriosis may be an underlying condition that could predispose to severe COVID-19 infection and what constitutes an appropriate indication for presentation for urgent treatment in the epidemic. Furthermore, the restrictions imposed due to COVID-19 can impose negative psychological effects, which patients with endometriosis may be more prone to already. In combination with medical therapies, or as an alternative, we encourage patients to consider self-management strategies to combat endometriosis symptoms during the COVID-19 pandemic. These self-management strategies are divided into problem-focused and emotion-focused strategies, with the former aiming to change the environment to alleviate pain, and the latter address the psychology of living with endometriosis. We put forward this guidance, which is based on evidence and expert opinion, for healthcare providers to utilize during their consultations with patients via telephone or video. Patients may also independently use this article as an educational resource. The strategies discussed are not exclusively restricted to consideration during the COVID-19 pandemic. Most have been researched before this period of time and all will continue to be a part of the biopsychological approach to endometriosis long after COVID-19 restrictions are lifted

    An Aotearoa New Zealand survey of the impact and diagnostic delay for endometriosis and chronic pelvic pain

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    Chronic pelvic pain (CPP) causes important negative effects on quality of life. Endometriosis is the most common cause of CPP in females, and diagnostic delay is over six years internationally. Data remain scarce for CPP impact or diagnostic delay in Aotearoa New Zealand. This study used an online survey to explore the impact of CPP on various life domains for those aged over 18. Additionally, for those with an endometriosis diagnosis, diagnostic delay and factors affecting this over time were explored. There were 800 respondent (620 with self-reported endometriosis). CPP symptoms, irrespective of final diagnosis, started prior to age 20 and negatively impacted multiple life domains including employment, education, and relationships. Mean diagnostic delay for those with endometriosis was 8.7 years, including 2.9 years between symptom onset and first presentation and 5.8 years between first presentation and diagnosis. Five doctors on average were seen prior to diagnosis. However, there was a reduction in the interval between first presentation and diagnosis over time, from 8.4 years for those presenting before 2005, to two years for those presenting after 2012. While diagnostic delay is decreasing, CPP, irrespective of aetiology, continues to have a significant negative impact on the lives of those affected

    Endometriosis and the Coronavirus (COVID-19) Pandemic: Clinical Advice and Future Considerations

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    The COVID-19 pandemic has led to a dramatic shift in the clinical practice of women’s health and routine care for endometriosis has been severely disrupted. Endometriosis is defined as an inflammatory disease characterized by lesions of endometrial-like tissue outside the uterus that is associated with pelvic pain and/or infertility (1). It affects ∼10% of reproductive age women worldwide, is diagnosed by surgical visualization or by radiological imaging, and is managed with hormone treatments or by laparoscopic removal of lesions (2–4). At the time of writing, under the guidance of international gynecological organizations (5–7), many centers temporarily ceased offering outpatient appointments, diagnostic imaging for nonacute pelvic pain, surgery for endometriosis, and fertility treatments. In the absence of routine care pathways and uncertainty about when health services will be available again, endometriosis sufferers are likely to feel vulnerable and that resultant stress and anxiety may contribute to a worsening of symptoms. The pandemic poses several important questions for healthcare providers on how best to deliver care within these restrictions. Herein, we present clinical advice on the management of endometriosis during the COVID-19 pandemic and future considerations

    Anxiety, distress tolerance, and the relationship between complex posttraumatic stress disorder symptoms and alcohol use in veterans

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    Objectives: Little is known about whether distress tolerance and anxiety mediate the relationship between comorbid complex posttraumatic stress disorder (CPTSD) and alcohol use among military veterans. Here, we investigated the contribution of distress tolerance and anxiety on the strength of the CPTSD and alcohol use association. We hypothesized that the impact of a two‐factor model of CPTSD derived from subscale scores on the International Trauma Questionnaire (ITQ)—namely ITQ PTSD and ITQ Disturbances in Self Organization (DSO; e.g., issues with affective regulation/self‐belief and shame)—on alcohol use severity would be mediated by anxiety but not by distress tolerance. Methods: Participants included 403 community‐dwelling United Kingdom (UK) veterans (91.64% male, Mage = 51.15 years, SD = 12.48) recruited as part of a larger, online study. Results: Findings indicated that the influence of CPTSD symptoms on alcohol use severity was mediated by anxiety, not by distress tolerance, with greater relative impact due to ITQ DSO status than ITQ PTSD status. Conclusions: We identified the mediational influence of anxiety and distress tolerance on the association between CPTSD subscales and alcohol use in UK veterans. Interventions for anxiety may be adapted for reducing problematic alcohol use and the impact of CPTSD symptoms in veterans with comorbid PTSD and alcohol use disorder

    Professionalism, Golf Coaching and a Master of Science Degree: A commentary

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    As a point of reference I congratulate Simon Jenkins on tackling the issue of professionalism in coaching. As he points out coaching is not a profession, but this does not mean that coaching would not benefit from going through a professionalization process. As things stand I find that the stimulus article unpacks some critically important issues of professionalism, broadly within the context of golf coaching. However, I am not sure enough is made of understanding what professional (golf) coaching actually is nor how the development of a professional golf coach can be facilitated by a Master of Science Degree (M.Sc.). I will focus my commentary on these two issues

    Physician Compensation from Salary and Quality of Diabetes Care

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    OBJECTIVE: To examine the association between physician-reported percent of total compensation from salary and quality of diabetes care. DESIGN: Cross-sectional analysis. PARTICIPANTS: Physicians (n = 1248) and their patients with diabetes mellitus (n = 4200) enrolled in 10 managed care plans. MEASUREMENTS: We examined the associations between physician-reported percent compensation from salary and processes of care including receipt of dilated eye exams and foot exams, advice to take aspirin, influenza immunizations, and assessments of glycemic control, proteinuria, and lipid profile, intermediate outcomes such as adequate control of hemoglobin A1c, lipid levels, and systolic blood pressure levels, and satisfaction with provider communication and perceived difficulty getting needed care. We used hierarchical logistic regression models to adjust for clustering at the health plan and physician levels, as well as for physician and patient covariates. We adjusted for plan as a fixed effect, meaning we estimated variation between physicians using the variance within a particular health plan only, to minimize confounding by other unmeasured health plan variables. RESULTS: In unadjusted analyses, patients of physicians who reported higher percent compensation from salary (>90%) were more likely to receive 5 of 7 diabetes process measures and more intensive lipid management and to have an HbA1c<8.0% than patients of physicians who reported lower percent compensation from salary (<10%). However, these associations did not persist after adjustment. CONCLUSIONS: Our findings suggest that salary, as opposed to fee-for-service compensation, is not independently associated with diabetes processes and intermediate outcomes

    The dynamics of ovine gastrointestinal nematode infections within ewe and lamb cohorts on three Scottish sheep farms

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    Gastrointestinal nematodes (GIN) are a serious concern for sheep producers worldwide. However, there is a paucity of evidence describing the epidemiology of GIN on modern UK sheep farms. The aim of this paper was to understand whether expected seasonal variations of infection are still found in ewes and lambs under varying management strategies in temperate climates. Faecal egg counts (FEC) were conducted on freshly voided samples collected from groups of ewes and lambs every third week for twelve months on three farms in southeast Scotland. The patterns of egg output have been described here in relation to management practices undertaken on the farms. Despite changes in farming practice and climatic conditions, the findings complement historical studies detailing the epidemiology of GIN. Findings include a periparturient rise in ewe FEC on two of the farms, while lambing time treatment appeared to suppress this on the third farm. On the same two farms lamb FEC increased during the summer, reaching a peak in the autumn. The work also highlights how the ad hoc use of anthelmintics does little to impact these patterns
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