936 research outputs found

    Gratings photowritten in ion-exchanged glass channel waveguides

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    Gratings are photowritten in ion-exchanged glass channel waveguides. The transmission of these waveguides shows a rejection dip of almost 20dB. The polarisation dependence of these waveguide gratings is measured and discussed

    Grating formation in BGG31 glass by UV exposure

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    A three-dimensional index variation grating in bulk BGG31 glass written using neither hydrogen loading nor germanium doping is demonstrated. This material is useful for fabricating ion-exchanged waveguides, and its photosensitivity to ultraviolet (UV) radiation at 248nm has not been previously explored. Intensity measurements of the Bragg diffracted spots indicated a maximum index variation (Delta n) of similar to 4 x 10(-5)

    Long Covid at the crossroads: Comparisons and lessons from the treatment of patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)

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    Whilst parallels have been drawn between Long Covid and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), there is a well-documented history of negative stereotyping and marginalisation of patients with ME/CFS. A socio-politically oriented comparison of scientific, clinical and societal responses to Long Covid and ME/CFS is thus important to prevent similar harms arising among Long Covid patients. We identify four reasons for injustices in the treatment of ME/CFS patients, and discuss the risk of Long Covid following a similar trajectory. We conclude with policy and practice recommendations to help prevent such injustices arising again, including consideration of critical reflexivity in medical education

    Articular Cartilage Repair Using Marrow Stimulation Augmented with a Viable Chondral Allograft: 9-Month Postoperative Histological Evaluation

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    Marrow stimulation is frequently employed to treat focal chondral defects of the knee. However, marrow stimulation typically results in fibrocartilage repair tissue rather than healthy hyaline cartilage, which, over time, predisposes the repair to failure. Recently, a cryopreserved viable chondral allograft was developed to augment marrow stimulation. The chondral allograft is comprised of native viable chondrocytes, chondrogenic growth factors, and extracellular matrix proteins within the superficial, transitional, and radial zones of hyaline cartilage. Therefore, host mesenchymal stem cells that infiltrate the graft from the underlying bone marrow following marrow stimulation are provided with the optimal microenvironment to undergo chondrogenesis. The present report describes treatment of a trochlear defect with marrow stimulation augmented with this novel chondral allograft, along with nine month postoperative histological results. At nine months, the patient demonstrated complete resolution of pain and improvement in function, and the repair tissue consisted of 85% hyaline cartilage. For comparison, a biopsy obtained from a patient 8.2 months after treatment with marrow stimulation alone contained only 5% hyaline cartilage. These outcomes suggest that augmenting marrow stimulation with the viable chondral allograft can eliminate pain and improve outcomes, compared with marrow stimulation alone

    A logistic regression analysis of risk factors in ME/CFS pathogenesis

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    Background: Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex disease, whose exact cause remains unclear. A wide range of risk factors has been proposed that helps understanding potential disease pathogenesis. However, there is little consistency for many risk factor associations, thus we undertook an exploratory study of risk factors using data from the UK ME/CFS Biobank participants. We report on risk factor associations in ME/CFS compared with multiple sclerosis participants and healthy controls. Methods: This was a cross-sectional study of 269 people with ME/CFS, including 214 with mild/moderate and 55 with severe symptoms, 74 people with multiple sclerosis (MS), and 134 healthy controls, who were recruited from primary and secondary health services. Data were collected from participants using a standardised written questionnaire. Data analyses consisted of univariate and multivariable regression analysis (by levels of proximity to disease onset). Results: A history of frequent colds (OR = 8.26, P <= 0.001) and infections (OR = 25.5, P = 0.015) before onset were the strongest factors associated with a higher risk of ME/CFS compared to healthy controls. Being single (OR = 4.41, P <= 0.001), having lower income (OR = 3.71, P <= 0.001), and a family history of anxiety is associated with a higher risk of ME/CFS compared to healthy controls only (OR = 3.77, P < 0.001). History of frequent colds (OR = 6.31, P < 0.001) and infections before disease onset (OR = 5.12, P = 0.005), being single (OR = 3.66, P = 0.003) and having lower income (OR = 3.48, P = 0.001), are associated with a higher risk of ME/CFS than MS. Severe ME/CFS cases were associated with lower age of ME/CFS onset (OR = 0.63, P = 0.022) and a family history of neurological illness (OR = 6.1, P = 0.001). Conclusions: Notable differences in risk profiles were found between ME/CFS and healthy controls, ME/CFS and MS, and mild-moderate and severe ME/CFS. However, we found some commensurate overlap in risk associations between all cohorts. The most notable difference between ME/CFS and MS in our study is a history of recent infection prior to disease onset. Even recognising that our results are limited by the choice of factors we selected to investigate, our findings are consistent with the increasing body of evidence that has been published about the potential role of infections in the pathogenesis of ME/CFS, including common colds/flu

    Biomechanical considerations for optimising subretinal injections

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    \ua9 2024 The AuthorsSubretinal injection is the preferred delivery technique for various novel ocular therapies and is widely used because of its precision and efficient delivery of gene and cell therapies; however, choosing an injection point and defining delivery parameters to target a specified retinal location and area is an inexact science. We provide an overview of the key factors that play important roles during subretinal injections to refine the technique, enhance patient outcomes, and minimise risks. We describe the role of anatomical and physical variables that affect subretinal bleb propagation and shape and their impact on retinal integrity. We highlight the risks associated with subretinal injections and consider strategies to mitigate reflux and retinal trauma. Finally, we explore the emerging field of robotic assistance in improving intraocular manouvrability and precision to facilitate the injection procedure

    Evaluation of a culture-based pathogen identification kit for bacterial causes of bovine mastitis

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    Accurate identification of mastitis-causing bacteria supports effective management and can be used to implement selective use of antimicrobials for treatment. The objectives of this study were to compare the results from a culture-based mastitis pathogen detection test kit (‘VetoRapid’, Vétoquinol) with standard laboratory culture and to evaluate the potential suitability of the test kit to inform a selective treatment programme. Overall 231 quarter milk samples from five UK dairy farms were collected. The sensitivity and specificity of the test kit for the identification of Escherichia coli, Staphylococcus aureus, coagulase-negative staphylococci, Streptococcus uberis and Enterococcus spp. ranged from 17 per cent to 84 per cent and 92 per cent to 98 per cent, respectively. In total, 23 of 68 clinical samples were assigned as meeting the requirement for antimicrobial treatment (Gram-positive organism cultured) according to standard culture results, with the test kit results having sensitivity and specificity of 91 per cent and 78 per cent, respectively. Several occurrences of misidentification are reported, including S. aureus being misidentified as coagulase-negative staphylococci and vice versa. The test kit provides rapid preliminary identification of five common causes of bovine mastitis under UK field conditions and is likely to be suitable for informing selective treatment of clinical mastitis caused by Gram-positive organisms

    Supporting Self-management Among Young People With Acne Vulgaris Through a Web-Based Behavioral Intervention: Development and Feasibility Randomized Controlled Trial

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    Background: Acne is a common skin condition that is most prevalent in young people. It can have a substantial impact on the quality of life, which can be minimized with the appropriate use of topical treatments. Nonadherence to topical treatments for acne is common and often leads to treatment failure. Objective: The aim of this study is to develop a web-based behavioral intervention to support the self-management of acne and to assess the feasibility of recruitment, retention, and engagement of users with the intervention. Methods: The intervention was developed iteratively using the LifeGuide software and following the person-based approach for intervention development. The target behavior was appropriate use of topical treatments. Barriers and facilitators identified from the qualitative research and evidence from the wider literature were used to identify techniques to improve and promote their use. Young people with acne aged 14-25 years who had received treatment for acne in the past 6 months were invited to participate through mail-out from primary care practices in the South of England in a parallel, unblinded randomized trial. Participants were automatically randomized using a computer-generated algorithm to usual care or to usual care plus access to the web-based intervention. Usage data was collected, and a series of questionnaires, including the primary outcome measure for skin-specific quality of life (Skindex-16), were collected at baseline and at the 4- and 6-week follow-ups. Results: A total of 1193 participants were invited, and 53 young people with acne were randomized to usual care (27/53, 51%) or usual care plus intervention (26/53, 49%). The response rate for the primary outcome measure (Skindex-16) was 87% at 4 weeks, 6 weeks, and at both time points. The estimate of mean scores between groups (with 95% CI) using linear regression showed a trend in the direction of benefit for the web-based intervention group in the primary outcome measure (Skindex-16) and secondary measures (Patient Health Questionnaire-4 and the Problematic Experiences of Therapy Scale). Intervention usage data showed high uptake of the core module in the usual care plus web-based intervention group, with 88% (23/26) of participants completing the module. Uptake of the optional modules was low, with less than half visiting each (myth-busting quiz: 27%; living with spots or acne: 42%; oral antibiotics: 19%; what are spots or acne: 27%; other treatments: 27%; talking to your general practitioner: 12%). Conclusions: This study demonstrated the feasibility of delivering a trial of a web-based intervention to support self-management in young people with acne. Additional work is needed before a full definitive trial, including enhancing engagement with the intervention, recruitment, and follow-up rates

    How to prevent burnout in cardiologists? A review of the current evidence, gaps and future directions

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    Burnout is rising in all physicians and cardiologists are not an exemption. Cardiology is a very popular specialty among medical students as it is associated with outstanding training standards and high prestige and income. In this review, we critically summarize the evidence on consequences, causes, and evidence-based interventions for burnout with a view towards recommending the best strategies for promoting wellness in cardiologists. Only a handful of studies have examined burnout specifically in cardiologists. Evidence therefore was mainly extrapolated by larger studies in all physicians and other physician specialties. Burnout in cardiologists has serious negative personal and professional consequences and is associated with suboptimal healthcare outcomes for patients. Burnout in cardiologists is primarily driven by professional and healthcare system demands and inefficiencies such as excessive workload and role complexity, training and certification demands, inefficient compensation models and lack of resources, computerization and loss of autonomy. Moreover, loss of connectedness with patients, difficulties in balancing work and personal life and overvaluing compulsiveness and perfectionism in medical practice further increase the risk for burnout. Burnout among cardiologists may be best mitigated by organizational strategies complemented by individual stress reduction and reflection techniques under the resilience-based approach. Large-scale strategies are needed to mitigate burnout and promote physician wellness as a shared responsibility of healthcare systems and individuals and be committed in creating a new culture in medicine

    Implantation of a Novel Cryopreserved Viable Osteochondral Allograft for Articular Cartilage Repair in the Knee

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    Restoration and repair of articular cartilage injuries remain a challenge for orthopaedic surgeons. The standard first-line treatment of articular cartilage lesions is marrow stimulation; however, this procedure can often result in the generation of fibrous repair cartilage rather than the biomechanically superior hyaline cartilage. Marrow stimulation is also often limited to smaller lesions, less than 2 cm2. Larger lesions may require implantation of a fresh osteochondal allograft, though a short shelf life, size-matched donor requirements, potential challenges of bone healing, limited availability, and the relatively high price limit the wide use of this therapeutic approach. We present a straightforward, single-stage surgical technique of a novel reparative and restorative approach for articular cartilage repair with the implantation of a cryopreserved viable osteochondral allograft (CVOCA). The CVOCA contains full-thickness articular cartilage and a thin layer of subchondral bone, and maintains the intact native cartilage architecture with viable chondrocytes, growth factors, and extracellular matrix proteins to promote articular cartilage repair. We report the results of a retrospective case series of three patients who presented with articular cartilage lesions more than 2 cm2 and were treated with the CVOCA using the presented surgical technique. Patients were followed up to 2 years after implantation of the CVOCA and all three patients had satisfactory outcomes without adverse events. Controlled randomized studies are suggested for evaluation of CVOCA efficacy, safety, and long-term outcomes
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