221 research outputs found

    Product state control of bi-alkali chemical reactions

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    We consider ultracold, chemically reactive scattering collisions of the diatomic molecules KRb. When two such molecules collide in an ultracold gas, we find that they are energetically forbidden from reacting to form the trimer species K2_2Rb or Rb2_2K, hence can only react via the bond-swapping reaction 2KRb →\to K2_2 + Rb2_2. Moreover, the tiny energy released in this reaction can in principle be set to zero by applying electric or microwave fields, implying a means of controlling the available reaction channels in a chemical reaction.Comment: 4 pages double column, 2 figures, 2 table

    Anti-phospholipid syndrome leading to digital ischaemia and rare organ complications in systemic sclerosis and related disorders

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    Antiphospholipid syndrome (APS) is an acquired, autoimmune thrombophilia that can occur as a primary disorder (with no associated disease) or secondary to infection, medication usage and autoimmune rheumatic diseases (ARDs). The association between APS and systemic lupus erythematosus (SLE) is well established, and practicing rheumatologists check for APS antibodies in the routine assessment of SLE, particularly if clinical features such as thrombotic events or pregnancy loss are present. APS secondary to systemic sclerosis (SSc)-related disorders is less widely recognised and easily overlooked. We describe 5 cases that highlight the varied breadth of clinical manifestations of APS in the context of SSc and related disorders. These cases range from uncomplicated Raynaud’s phenomenon, digital ulceration/necrosis, critical digital ischaemia/gangrene and rare internal organ complications of APS in SSc-spectrum disorders. To our knowledge, our cases include the first reported case of secondary APS contributing to digital necrosis in the context of RACAND syndrome (Raynaud’s phenomenon, anti-centromere antibodies and necrosis of the digits) and the first reported case of secondary APS in SSc causing posterior reversible encephalopathy syndrome (PRES). The case series is accompanied by a comprehensive review of the literature relevant to each case. Rheumatologists should be alert to the possibility of APS in SSc-spectrum disorders and should routinely check APS antibodies in all patients at diagnosis, and again later in the disease course if new features emerge that could indicate the presence of thrombotic events or other recognised APS manifestations.Key points• APS should be considered in all patients with digital ischaemic symptoms.• APS may be an important driver of SSc-related digital ulceration/necrosis.• Identification of SSc-associated APS opens up new therapeutic options for acute management and secondary prevention.</p

    Pauling and Frech reply

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    We thank Dr. Hughes for his interest1 in our article2 reporting factors influencing Raynaud phenomenon (RP) symptom reporting in patients with systemic sclerosis (SSc). We presented data demonstrating differences in Raynaud symptom reporting using the Raynaud Condition Score (RCS) diary depending on season of enrollment2.</p

    Behaviour change interventions for the management of Raynaud's phenomenon : a systematic review protocol

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    Introduction Raynaud's phenomenon (RP) describes excessive peripheral vasospasm to cold exposure and/or emotional stress. RP episodes are associated with digital colour changes, pain and reduced quality of life. Pharmacological interventions are of low to moderate efficacy and often result in adverse effects such as facial flushing and headaches. Recommended lifestyle and behavioural interventions have not been evaluated. The objectives of the proposed systematic review are to assess the comparative safety and efficacy of behaviour change interventions for RP and identify what we can learn to inform future interventions. Methods and analysis Studies eligible for inclusion include randomised controlled trials testing behaviour change interventions with a control comparator. A comprehensive search strategy will include peer review and grey literature up until 30 April 2017. Search databases will include Medline, Embase, PsychINFO and Cochrane. Initial sifting, eligibility, data extraction, risk of bias and quality assessment will be subject to review by two independent reviewers with a third reviewer resolving discrepancies. Risk of bias assessment will be performed using Cochrane risk of a bias assessment tool with quality of evidence assessed using Grading of Recommendations Assessment, Development and Evaluation(GRADE). A meta-analysis will be performed if there are sufficient data. Two subgroup analyses are planned: primary versus secondary RP outcomes; comparison of theoretically informed interventions with pragmatic interventions. Ethics and dissemination This review does not require ethical approval as it will summarise published studies with non-identifiable data. This protocol complies with the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) guidelines. Findings will be disseminated in peer-reviewed articles and reported according to PRISMA. This review will make a significant contribution to the management of RP where no review of behaviour-change interventions currently exist. The synopsis and protocol for the proposed systematic review is registered in the International Prospective Register of Systematic Reviews (registration number CRD42017049643)

    The challenge of establishing treatment efficacy for cutaneous vascular manifestations of systemic sclerosis

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    INTRODUCTION: The cutaneous vascular manifestations of systemic sclerosis (SSc) comprise Raynaud's phenomenon, cutaneous ulceration, telangiectasia formation and critical digital ischaemia; each of which are associated with significant disease-related morbidity. Despite the availability of multiple classes of vasodilator therapy, many of which have been the subject of RCTs, a limited number of pharmacological interventions are currently approved for the management of cutaneous vascular manifestations of SSc. Areas covered: A major challenge has been demonstrating treatment efficacy with examples of promising therapies yielding contrasting results in controlled trial settings. Differences between consensus best-practice guidelines, evidence-based recommendations and marketing approvals in different jurisdictions has resulted in geographic variation in clinical practice concerning the management of cutaneous vascular manifestations of SSc. Difficulty demonstrating treatment efficacy risks waning industry engagement for drug development programmes in this field. This article highlights the key challenges in establishing treatment efficacy and barriers that must be overcome to support successful clinical trial programmes across the spectrum of cutaneous vascular manifestations of SSc. Expert commentary: The paucity of approved treatments for cutaneous vascular manifestations of SSc relates as much to challenges in clinical trial design and the need for reliable clinical trial endpoints, as to lack of therapeutic options.</p

    Impact of Covid-19 on clinical care and lived experience of systemic sclerosis:An international survey from EURORDIS-Rare Diseases Europe

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    INTRODUCTION: Outcomes related to Covid-19 in systemic sclerosis patients could be influenced by internal organ involvement and/or immunosuppressive treatment, leading to efforts to shield patients from Covid-19 transmission. We examined the impact of Covid-19 on the lived experience of systemic sclerosis with regards to other aspects of daily living including occupation and emotional well-being. METHOD: Individuals with systemic sclerosis or relatives/carers participated in an online survey, disseminated through international patient associations and social media pages, designed to examine the impact of Covid-19 on living with a rare disease. RESULTS: Responses from 121 individuals (98% were patients with systemic sclerosis) from 14 countries were evaluable. Covid-19 was considered a probable/definite personal threat (93%) or threat for the individual they care for (100%). Approximately two-thirds of responders reported either cancellation or postponement/delay to appointments, diagnostic tests, medical therapies at home (e.g. infusions), surgery or transplant, psychiatry follow-up or rehabilitation services. Twenty-six percent reported at least one systemic sclerosis medicine/treatment had been unavailable, and 6% had to either stop taking usual medications or use an alternative. Most reported online consultations/telemedicine via phone (88%) and online (96%) as being ‘fairly’ or ‘very’ useful. Respondents reported tensions among family members (45%) and difficulty overcoming problems (48%). Restrictions on movement left around two-thirds feeling isolated (61%), unhappy and/or depressed (64%), although the majority (85%) reported a strengthening of the family unit. CONCLUSION: Covid-19 has resulted in significant impact on the clinical-care and emotional well-being of systemic sclerosis patients. Changes to clinical care delivery have been well-received by patients including telemedicine consultations

    Does nailfold capillaroscopy help predict future outcomes in systemic sclerosis?:A systematic literature review

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    BACKGROUND: Nailfold capillaroscopy (NC) is an important diagnostic tool in systemic sclerosis (SSc). Confirmation of NC as a prognostic factor could facilitate earlier intervention and slow disease progression in SSc. We undertook a systematic literature review to evaluate the prognostic value of NC in predicting SSc disease progression.METHODS: Standardised searches of EMBASE and MEDLINE were undertaken to identify longitudinal studies of adult subjects with SSc reporting the prognostic value of NC for any aspect of disease progression and/or survival. Non-English, non-original research, animal studies, non-adult studies and non-full length reports were excluded from the analysis (PROSPERO 2017:CRD42017071719). Wide heterogeneity in study design, prognostic factor measurement and study outcomes necessitated a qualitative data synthesis. The "QUality In Prognosis Studies" (QUIPS) risk-of-bias tool was used to assess study quality. Study selection, data extraction and risk-of-bias assessment were each undertaken independently by 2 reviewers and consensus reached where necessary.RESULTS: Of 942 retrieved articles, 18 studies fulfilled the inclusion criteria. The majority of studies (17/18, 94%) reported positive associations between baseline NC appearances (using a variety of qualitative, semi-quantitative and quantitative NC endpoints) and clinical outcomes including digital ulcer (DU) occurrence/healing, survival, disease progression (using domains of Medsger disease severity scale), calcinosis, skin progression, pulmonary arterial hypertension (PAH), and/or a composite analysis of "cardiovascular events". Application of the QUIPS tool identified a moderate-high risk of potential bias in 6/18 studies for study participation, 3/18 studies for study attrition, 10/18 for prognostic factor measurement, 5/18 for outcome measurement, 13/18 for confounders and 13/18 for statistical analyses. Study quality limited the strength of the conclusions drawn from these studies. The most important source of potential bias across the studies was insufficient adjustment for potential confounders; such as existing DU disease in studies evaluating future DU occurrence. Recent work suggests NC evolution is an important predictor of disease progression in SSc.CONCLUSIONS: High levels of potential bias relating to study confounding and statistical analysis make it difficult to draw conclusions regarding the prognostic role of NC in SSc. There is strong evidence supporting an association between NC abnormalities (particularly capillary loss) and disease severity (particularly vascular manifestations such as DU, calcinosis and PAH). Evolution of NC appearances may represent a more important predictor of disease progression which could have important implications for the future use of NC in the routine longitudinal assessment and management of SSc.</p
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