350 research outputs found

    Energy Deposition in Adjacent LHC Superconducting Magnets from Beam Loss at LHC Transfer Line Collimators

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    Injection intensities for the LHC are over an order of magnitude above the damage threshold. The collimation system in the two transfer lines is designed to dilute the beam sufficiently to avoid damage in case of accidental beam loss or mis-steered beam. To maximise the protection for the LHC most of the collimators are located in the last 300 m upstream of the injection point where the transfer lines approach the LHC machine. To study the issue of possible quenches following beam loss at the collimators part of the collimation section in one of the lines, TI 8, together with the adjacent part of the LHC has been modeled in FLUKA. The simulated energy deposition in the LHC for worst-case accidental losses and as well as for losses expected during a normal filling is presented

    Photon echo quantum memories in inhomogeneously broadened two level atoms

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    Here we propose a solid-state quantum memory that does not require spectral holeburning, instead using strong rephasing pulses like traditional photon echo techniques. The memory uses external broadening fields to reduce the optical depth and so switch off the collective atom-light interaction when desired. The proposed memory should allow operation with reasonable efficiency in a much broader range of material systems, for instance Er3+ doped crystals which have a transition at 1.5 um. We present analytic theory supported by numerical calculations and initial experiments.Comment: 7 pages, 8 figure

    The Unmet Need for Interpreting Provision in UK Primary Care

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    Background: With increasing globalisation, the challenges of providing accessible and safe healthcare to all are great. Studies show that there are substantial numbers of people who are not fluent in English to a level where they can make best use of health services. We examined how health professionals manage language barriers in a consultation.Methods and Findings: This was a cross-sectional study in 41 UK general practices. Health professionals completed a proforma for a randomly allocated consultation session. Seventy-seven (63%) practitioners responded, from 41(59%) practices. From 1008 consultations, 555 involved patients who did not have English as a first language; 710 took place in English; 222 were in other languages, the practitioner either communicating with the patient in their own language/using an alternative language. Seven consultations were in a mixture of English/patient's own language. Patients' first languages numbered 37 (apart from English), in contrast to health practitioners, who declared at least a basic level of proficiency in 22 languages other than English. The practitioner's reported proficiency in the language used was at a basic level in 24 consultations, whereas in 21, they reported having no proficiency at all. In 57 consultations, a relative/friend interpreted and in 6, a bilingual member of staff/community worker was used. Only in 6 cases was a professional interpreter booked. The main limitation was that only one random session was selected and assessment of patient/professional fluency in English was subjective.Conclusions: It would appear that professional interpreters are under-used in relation to the need for them, with bilingual staff/family and friends being used commonly. In many cases where the patient spoke little/no English, the practitioner consulted in the patient's language but this approach was also used where reported practitioner proficiency was low. Further research in different setting is needed to substantiate these findings

    Experimental realization of light with time separated correlations by rephasing amplified spontaneous emission

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    Amplified spontaneous emission is a common noise source in active optical systems, it is generally seen as being an incoherent process. Here we excite an ensemble of rare earth ion dopants in a solid with a {\pi}-pulse, resulting in amplified spontaneous emission. The application of a second {\pi}-pulse leads to a coherent echo of the amplified spontaneous emission that is correlated in both amplitude and phase. For small optical thicknesses, we see evidence that the amplified spontaneous emission and its echo are entangled.Comment: 6 pages, 5 figures, the supplementary information pdf was uploaded with latex source files. This version accepted for publication in PR

    Is looped nasogastric tube feeding more effective than conventional nasogastric tube feeding for dysphagia in acute stroke?

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    Background: Dysphagia occurs in up to 50% of patients admitted to hospital with acute strokes with up to 27% remaining by seven days. Up to 8% continue to have swallowing problems six months after their stroke with 1.7% still requiring enteral feeding. Nasogastric tubes (NGT) are the most commonly used method for providing enteral nutrition in early stroke, however they are easily and frequently removed leading to inadequate nutrition, early PEG (Percutaneous Endoscopic Gastrostomy) insertion or abandoning of feeding attempts. Looped nasogastric tube feeding may improve the delivery of nutrition to such patients. Methods: Three centre, two arm randomised controlled trial, with 50 participants in each arm comparing loop (the intervention) versus conventional nasogastric tube feeding. The primary outcome measure is proportion of intended feed delivered in the first 2 weeks. The study is designed to show a mean increase of feed delivery of 16% in the intervention group as compared with the control group, with 90% power at a 5% significance level. Secondary outcomes are treatment failures, mean volume of feed received, adverse events, cost-effectiveness, number of chest x-rays, number of nasogastric tubes and tolerability

    Four decades of overdose prevention centres: lessons for the future from a realist review

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    Background: Overdose prevention centres (OPCs) are spaces where people can consume previously obtained illicit drugs under the supervision of staff who can intervene to prevent and manage overdose. They have been provided in Europe and elsewhere for nearly 40 years, initially in response to the epidemic of HIV/AIDS. We can learn from their operation history to inform future developments in harm reduction services. Methods: We carried out a realist review of 391 documents, reported according to the RAMESES I guidelines, and carried out realist synthesis of these documents. Results: We present a full realist programme theory of OPCs, with a diagrammatic logic model, of how the contexts and mechanisms of OPCs combine to produce various outcomes for service users and their communities in different settings. Three specific causal pathways were evidenced through which OPCs produce their outcomes for particular groups in specific contexts of housing status, gender identity and ethnicity, and local drug markets, with frequency of use, legal and political contexts, and stigma as overlapping contextual factors. Key OPC interventions include the provision of a safe and hygienic consumption space, safe consumption education, timely overdose response, and protection from drug scene and gender-based violence. These can trigger the underlying mechanisms of safety, trust, social inclusion, engagement, autonomy, and empowerment when supported with health care and other services, including detoxification and opioid agonist treatment. The combinations of these contexts and mechanisms create important outcomes for individual service users, for the communities they live in, and for wider society. We also describe causal pathways that can lead to unintended, adverse outcomes. Conclusion: This review provides useful information for policy makers, practitioners, and researchers on how to implement and evaluate OPCs in future to maximise their benefits; an important task in the context of the ongoing public health crises of drug poisoning deaths in North America and the UK, and the possibility of increasing deaths from synthetic opioids in Europe and elsewhere

    Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS): a randomised, open-label, phase 3 superiority trial

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    Background: Intensive antiplatelet therapy with three agents might be more effective than guideline treatment for preventing recurrent events in patients with acute cerebral ischaemia. We aimed to compare the safety and efficacy of intensive antiplatelet therapy (combined aspirin, clopidogrel, and dipyridamole) with that of guideline-based antiplatelet therapy. Methods: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using computer randomisation to receive loading doses and then 30 days of intensive antiplatelet therapy (combined aspirin 75 mg, clopidogrel 75 mg, and dipyridamole 200 mg twice daily) or guideline-based therapy (comprising either clopidogrel alone or combined aspirin and dipyridamole). Randomisation was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using the modified Rankin Scale) or TIA within 90 days, as assessed by central telephone follow-up with masking to treatment assignment, and analysed by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN47823388. Findings: 3096 participants (1556 in the intensive antiplatelet therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did not differ between intensive and guideline therapy (93 [6%] participants vs 105 [7%]; adjusted common odds ratio [cOR] 0·90, 95% CI 0·67–1·20, p=0·47). By contrast, intensive antiplatelet therapy was associated with more, and more severe, bleeding (adjusted cOR 2·54, 95% CI 2·05–3·16, p<0·0001). Interpretation: Among patients with recent cerebral ischaemia, intensive antiplatelet therapy did not reduce the incidence and severity of recurrent stroke or TIA, but did significantly increase the risk of major bleeding. Triple antiplatelet therapy should not be used in routine clinical practice
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