Global oceanic emission of ammonia: constraints from seawater and atmospheric observations

Current global inventories of ammonia emissions identify the ocean as the largest natural source. This source depends on seawater pH, temperature, and the concentration of total seawater ammonia (NHx(sw)), which reflects a balance between remineralization of organic matter, uptake by plankton, and nitrification. Here we compare [NHx(sw)] from two global ocean biogeochemical models (BEC and COBALT) against extensive ocean observations. Simulated [NHx(sw)] are generally biased high. Improved simulation can be achieved in COBALT by increasing the plankton affinity for NHx within observed ranges. The resulting global ocean emissions is 2.5 TgN a−1, much lower than current literature values (7–23 TgN a−1), including the widely used Global Emissions InitiAtive (GEIA) inventory (8 TgN a−1). Such a weak ocean source implies that continental sources contribute more than half of atmospheric NHx over most of the ocean in the Northern Hemisphere. Ammonia emitted from oceanic sources is insufficient to neutralize sulfate aerosol acidity, consistent with observations. There is evidence over the Equatorial Pacific for a missing source of atmospheric ammonia that could be due to photolysis of marine organic nitrogen at the ocean surface or in the atmosphere. Accommodating this possible missing source yields a global ocean emission of ammonia in the range 2–5 TgN a−1, comparable in magnitude to other natural sources from open fires and soils

Intrarater reliability and agreement of linear encoder derived heel-rise endurance test outcome measures in healthy adults

publisher: Elsevier articletitle: Intrarater reliability and agreement of linear encoder derived heel-rise endurance test outcome measures in healthy adults journaltitle: Journal of Electromyography and Kinesiology articlelink: http://dx.doi.org/10.1016/j.jelekin.2017.07.004 content_type: article copyright: © 2017 Elsevier Ltd. All rights reserved

Progressive functional exercise versus best practice advice for adults aged 50 years or over after ankle fracture: protocol for a pilot randomised controlled trial in the UK - the Ankle Fracture Treatment: Enhancing Rehabilitation (AFTER) study

Introduction Ankle fractures result in significant morbidity in adults, with prognosis worsening with increasing age. Previous trials have not found evidence supporting supervised physiotherapy sessions, but these studies have not focused on older adults or tailored the exercise interventions to the complex needs of this patient group. The Ankle Fracture Treatment: Enhancing Rehabilitation study is a pilot randomised controlled trial to assess feasibility of a later definitive trial comparing best-practice advice with progressive functional exercise for adults aged 50 years and over after ankle fracture. The main objectives are to assess: (i) patient engagement with the trial, measured by the participation rate of those eligible; (ii) establish whether the interventions are acceptable to participants and therapists, assessed by intervention adherence levels, participant interviews and a therapist focus group; (iii) participant retention in the trial, measured by the proportion of participants providing outcome data at 6 months; (iv) acceptability of measuring outcomes at 3 and 6 month follow-up. Methods and analysis A multicentre pilot randomised controlled trial with an embedded qualitative study. At least 48 patients aged 50 years and over with an ankle fracture requiring surgical management, or non-operative management by immobilisation for at least 4 weeks, will be recruited from a minimum of three National Health Service hospitals in the UK. Participants will be allocated 1:1 via a central web-based randomisation system to: (i) best-practice advice (one session of face-to-face self-management advice delivered by a physiotherapist and up to two optional additional sessions) or (ii) progressive functional exercise (up to six sessions of individual face-to-face physiotherapy). An embedded qualitative study will include one-to-one interviews with up to 20 participants and a therapist focus group. Ethics and dissemination Hampshire B Research Ethics Committee (18/SC/0281) gave approval on 2nd July 2018. Trial registration number ISRCTN1661233

Experience of patients and physiotherapists within the AFTER pilot randomised trial of two rehabilitation interventions for people aged 50 years and over post ankle fracture: a qualitative study.

This is the final version. Available from BMJ Publishing via the DOI in this record. Data availability statement: Data are available upon reasonable request.OBJECTIVES: To explore patient and staff experience of best-practice rehabilitation advice (one session of face-to-face self-management advice with up to two additional optional sessions) compared with progressive functional exercise (up to six sessions of face-to-face physiotherapy) after ankle fracture. DESIGN: The study drew on phenomenology using interviews and a focus group. SETTING: Participants were from three NHS Trusts in England, UK. PARTICIPANTS: A purposive sample of 20 patients with ankle (malleolar) fractures from the Ankle Fracture Treatment: Enhancing Rehabilitation-pilot trial (now completed) were interviewed (median 50 min) from May 2019 to January 2020. They were 6 months post injury, over 50 years of age, (median 66, 12 females) and had received surgical or non-surgical treatment (seven internal fixation surgery, seven close contact casting, six walking boot). A focus group of five physiotherapists who had provided the study interventions (2.5 hours) was undertaken. RESULTS: The findings show the acceptability of both interventions through the themes, 'being helped' (for patients) and 'developing expertise' (for staff) with subthemes of choosing and progressing. Progressive exercise added value with a perceived increase in strength, motion, ability to undertake activities and continued use of the workbook. Both staff and patients valued physiotherapy expertise demonstrated through interpersonal skills, advice, individualised exercise plans and active monitoring of progression. Best practice advice was particularly helpful in the early stages of recovery and with the use of mobility aids. CONCLUSION: Both interventions were acceptable but progressive exercise was highly valued by patients. Developing expertise through experiential learning enabled staff to facilitate progression. Adjustments to the workbook and the addition of exercises for continued recovery in the best practice advice would enhance a future study. Research during treatment provision may provide further insights into the challenges of facilitating progression of exercise. TRIAL REGISTRATION: ISRCTN16612336; AFTER-pilot trial).National Institute for Health Researc

Platelet rich Plasma in Achilles Tendon Healing 2 (PATH-2) trial: protocol for a multicentre, participant and assessor-blinded, parallel-group randomised clinical trial comparing platelet-rich plasma (PRP) injection versus placebo injection for Achilles tendon rupture

BackgroundAchilles tendon injuries give rise to substantial long-lasting morbidity and pose considerable challenges for clinicians and patients during the lengthy healing period. Current treatment strategies struggle to curb the burden of this injury on health systems and society due to lengthy rehabilitation, work absence and reinjury risk. Platelet-rich plasma (PRP) is an autologous preparation that has been shown to improve the mechanobiological properties of tendons in laboratory and animal studies. The use of PRP in musculoskeletal injuries is on the increase despite the lack of adequately powered clinical studies.Methods and designThis is a multicentre randomised controlled trial to evaluate the efficacy and mechanism of PRP in patients with acute Achilles tendon rupture (ATR). All adults with acute ATR presenting within 12 days of the injury who are to be treated non-operatively are eligible. A total of 230 consenting patients will be randomly allocated via a remote web-based service to receive PRP injection or placebo injection to the site of the injury. All participants will be blinded to the intervention and will receive standardised rehabilitation to reduce efficacy interference.Participants will be followed up with blinded assessments of muscle–tendon function, quality of life, pain and overall patient’s functional goals at 4, 7, 13, 24 weeks and 24 months post-treatment. The primary outcome is the heel-rise endurance test (HRET), which will be supervised by a blinded assessor at 24 weeks. A subgroup of 16 participants in one centre will have needle biopsy under ultrasound guidance at 6 weeks. Blood and PRP will be analysed for cell count, platelet activation and growth factor concentrations.Ethics and disseminationThe protocol has been approved by the Oxfordshire Research Ethics Committee (Oxfordshire Research Ethics Committee A, reference no 14/SC/1333). The trial will be reported in accordance with the CONSORT statement and published in peer-reviewed scientific journals.Trial registration numberISRCTN: 54992179, assigned 12 January 2015. ClinicalTrials.gov:NCT02302664, received 18 November 2014. UK Clinical Research Network Study Portfolio Database: ID 17850.</jats:sec

Platelet rich plasma injection for acute Achilles tendon rupture: PATH-2 randomised, placebo controlled, superiority trial

This is the final version. Available on open access from BMJ Publishing via the DOI in this record. Objective To determine whether an injection of platelet rich plasma improves outcomes after acute Achilles tendon rupture. Design Randomised, placebo controlled, two arm, parallel group, participant and assessor masked, superiority trial. Setting Secondary care trauma units across 19 hospitals in the United Kingdom's health service. Participants Recruitment commenced in July 2015 and follow-up was completed in March 2018. 230 adults aged 18 years and over were included, with acute Achilles tendon rupture presenting within 12 days of injury and managed with non-surgical treatment. Exclusions were injury at the insertion or musculotendinous junction, major leg injury or deformity, diabetes mellitus, platelet or haematological disorder, systemic corticosteroids, anticoagulation treatment, and other contraindicating conditions. Interventions Participants were randomised 1:1 to platelet rich plasma (n=114) or placebo (dry needle; n=116) injection. All participants received standard rehabilitation care (ankle immobilisation followed by physiotherapy). Main outcomes and measures Primary outcome was muscle tendon function at 24 weeks, measured objectively with the limb symmetry index (injured/uninjured×100) in maximal work done during the heel rise endurance test (an instrumented measure of repeated single leg heel rises until fatigue). Secondary outcomes included patient reported function (Achilles tendon rupture score), quality of life (short form 12 version 2®), pain (visual analogue scale), goal attainment (patient specific functional scale), and adverse events. A central laboratory analysed the quality and content of platelet rich plasma. Analyses were by modified intention to treat. Results Participants were 46 years old on average, and 57 (25%) of 230 were female. At 24 weeks, 202 (88%) participants completed the heel rise endurance test and 216 (94%) the patient reported outcomes. The platelet rich plasma was of good quality, with expected growth factor content. No difference was detected in muscle tendon function between participants receiving platelet rich plasma injections and those receiving placebo injections (limb symmetry index, mean 34.7% (standard deviation 17.7%) v 38.5% (22.8%); adjusted mean difference -3.9% (95% confidence interval -10.5% to 2.7%)) or in any secondary outcomes or adverse event rates. Complier average causal effect analyses gave similar findings. Conclusions There is no evidence to indicate that injections of platelet rich plasma can improve objective muscle tendon function, patient reported function, or quality of life after acute Achilles tendon rupture compared with placebo, or that they offer any patient benefit. Trial registration ISRCTN54992179.Efficacy and Mechanism Evaluation programme, a Medical Research Council (MRC) and National Institute for Health Research (NIHR) partnershi

Platelet-rich plasma injection for adults with acute Achilles tendon rupture: the PATH-2 RCT

BACKGROUND:Achilles tendon rupture (ATR) has a long healing period, which is challenging for patients and clinicians. Platelet-rich plasma (PRP) is an autologous concentration of platelets thought to improve tendon function recovery. Although preliminary research has indicated positive effects, there is, as yet, no evidence of clinical efficacy from adequately powered robust clinical trials. OBJECTIVES:The objectives were to determine the clinical efficacy of PRP in patients with acute ATR using an objective mechanical muscle–tendon function measure and patient-reported outcome measures (PROMs), and to determine which PRP components contribute to its mechanism. DESIGN:This was a multicentre, parallel-group, participant- and outcome assessor-blinded randomised controlled trial (RCT) comparing PRP with placebo. Two embedded substudies investigated the PRP’s quality and composition and its effects on healing tendon tissues. SETTING:This trial was set in trauma and orthopaedic surgery departments in 19 NHS hospitals in England and Wales. PARTICIPANTS:Adults with acute ATR presenting within 12 days of injury to be treated non-surgically were eligible. Patients with platelet dysfunction or leg functional deficiency were excluded. INTERVENTIONS:Participants were randomised 1 : 1 to the PRP injection group or the placebo group (dry needle in the rupture gap) by central computer-based randomisation using minimisation, stratified by centre and age. MAIN OUTCOME MEASURES:The primary outcome measure was the Limb Symmetry Index (LSI) of work during the heel-rise endurance test at 24 weeks. Secondary outcomes measures, collected at 4, 7, 13 and 24 weeks, were repetitions, maximum heel-rise height, Achilles tendon Total Rupture Score (ATRS), quality of life (as measured using the Short Form questionnaire-12 items version 2), pain and participant goal attainment. Needle biopsies of the affected tendon zone were taken under ultrasound guidance at 6 weeks from 16 participants from one centre. Whole blood was analysed for cell count. PRP was analysed for cell count, platelet activation and growth factor concentration. The primary analysis was intention to treat. RESULTS:A total of 230 participants were randomised: 114 to the PRP group (103 treated) and 116 to the placebo group (all treated). One participant withdrew after randomisation but before the intervention. At 24 weeks, 201 out of 230 participants (87.4%) completed the primary outcome and 216 out of 230 participants (93.9%) completed the PROMs. The treatment groups had similar participant characteristics. At 24 weeks, there was no difference in work LSI (mean difference –3.872; 95% confidence interval –10.454 to 2.710; p = 0.231), ATRS, pain or goal attainment between PRP- and placebo-injected participants. There were no differences between the groups in any PROM at any time point or in complication rates, including re-rupture and deep-vein thrombosis. There was no correlation between work LSI and platelet activation in PRP, or erythrocyte, leucocyte or platelet counts in whole blood or PRP. Biopsies showed similar cellularity and vascularity between groups. CONCLUSIONS:This trial design and standardised PRP preparation gives the first robust RCT evidence about PRP’s role in managing ATR, which suggests that PRP offers no patient benefit. Equally robust evidence to investigate PRP application in tendon and soft tissue injuries is required. The 24-month follow-up will be completed in April 2020. TRIAL REGISTRATION:Current Controlled Trials ISRCTN54992179. FUNDING:This project was funded by the Efficacy and Mechanism Evaluation programme, a Medical Research Council and National Institute for Health Research (NIHR) partnership. The trial was supported by the NIHR Biomedical Research Centre, Oxford, and the NIHR Fellowship programme

Lower limb muscle strength and balance in older adults with a distal radius fracture: a systematic review.

This is the final version. Available from BMC via the DOI in this record. Data Availability: The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.BACKGROUND: Distal radius fractures are common fractures in older adults and associated with increased risk of future functional decline and hip fracture. Whether lower limb muscle strength and balance are impaired in this patient population is uncertain. To help inform rehabilitation requirements, this systematic review aimed to compare lower limb muscle strength and balance between older adults with a distal radius fracture with matched controls, and to synthesise lower limb muscle strength and balance outcomes in older adults with a distal radius fracture. METHODS: We searched Embase, MEDLINE, and CINAHL (1990 to 25 May 2022) for randomised and non-randomised controlled clinical trials and observational studies that measured lower limb muscle strength and/or balance using instrumented measurements or validated tests, in adults aged ≥ 50 years enrolled within one year after distal radius fracture. We appraised included observational studies using a modified Newcastle-Ottawa Scale and included randomised controlled trials using the Cochrane risk-of-bias tool. Due to the clinical and methodological heterogeneity in included studies, we synthesised results narratively in tables and text. RESULTS: Nineteen studies (10 case-control studies, five case series, and four randomised controlled trials) of variable methodological quality and including 1835 participants (96% women, mean age 55-73 years, median sample size 82) were included. Twelve included studies (63%) assessed strength using 10 different methods with knee extension strength most commonly assessed (6/12 (50%) studies). Five included case-control studies (50%) assessed lower limb strength. Cases demonstrated impaired strength during functional tests (two studies), but knee extension strength assessment findings were conflicting (three studies). Eighteen included studies (95%) assessed balance using 14 different methods. Single leg balance was most commonly assessed (6/18 (33%) studies). All case-control studies assessed balance with inconsistent findings. CONCLUSION: Compared to controls, there is some evidence that older adults with a distal radius fracture have impaired lower limb muscle strength and balance. A cautious interpretation is required due to inconsistent findings across studies and/or outcome measures. Heterogeneity in control participants' characteristics, study design, study quality, and assessment methods limited synthesis of results. Robust case-control and/or prospective observational studies are needed. REGISTRATION: International prospective register of systematic reviews (date of registration: 02 July 2020, registration identifier: CRD42020196274).National Institute for Health Research (NIHR)NIHR Biomedical Research Centr

Ecological momentary assessment of fatigue, sleepiness, and exhaustion in ESKD

Background: Many patients on maintenance dialysis experience significant sleepiness and fatigue. However, the influence of the hemodialysis (HD) day and circadian rhythms on patients' symptoms have not been well characterized. We sought to use ecological momentary assessment to evaluate day-to-day and diurnal variability of fatigue, sleepiness, exhaustion and related symptoms in thrice-weekly maintenance HD patients. Methods. Subjects used a modified cellular phone to access an interactive voice response system that administered the Daytime Insomnia Symptom Scale (DISS). The DISS assessed subjective vitality, mood, and alertness through 19 questions using 7- point Likert scales. Subjects completed the DISS 4 times daily for 7 consecutive days. Factor analysis was conducted and a mean composite score of fatigue-sleepiness- exhaustion was created. Linear mixed regression models (LMM) were used to examine the association of time of day, dialysis day and fatigue, sleepiness, and exhaustion composite scores. Results: The 55 participants completed 1,252 of 1,540 (81%) possible assessments over the 7 day period. Multiple symptoms related to mood (e.g., feeling sad, feeling tense), cognition (e.g., difficulty concentrating), and fatigue (e.g., exhaustion, feeling sleepy) demonstrated significant daily and diurnal variation, with higher overall symptom scores noted on hemodialysis days and later in the day. In factor analysis, 4 factors explained the majority of the observed variance for DISS symptoms. Fatigue, sleepiness, and exhaustion loaded onto the same factor and were highly intercorrelated. In LMM, mean composite fatigue-sleepiness-exhaustion scores were associated with dialysis day (coefficient and 95% confidence interval [CI] 0.21 [0.02 - 0.39]) and time of day (coefficient and 95% CI 0.33 [0.25 - 0.41]. Observed associations were minimally affected by adjustment for demographics and common confounders. Conclusions: Maintenance HD patients experience fatigue-sleepiness-exhaustion symptoms that demonstrate significant daily and diurnal variation. The variability in symptoms may contribute to poor symptom awareness by providers and greater misclassification bias of fatigue related symptoms in clinical studies. © 2014 Abdel-Kader et al.; licensee BioMed Central Ltd

Platelet-rich plasma injection for acute Achilles tendon rupture : two-year follow-up of the PATH-2 randomized, placebo-controlled, superiority trial

This is the final version. Available on open access from the British Editorial Society of Bone and Joint Surgery via the DOI in this recordAIMS: To determine whether platelet-rich plasma (PRP) injection improves outcomes two years after acute Achilles tendon rupture. METHODS: A randomized multicentre two-arm parallel-group, participant- and assessor-blinded superiority trial was undertaken. Recruitment commenced on 28 July 2015 and two-year follow-up was completed in 21 October 2019. Participants were 230 adults aged 18 years and over, with acute Achilles tendon rupture managed with non-surgical treatment from 19 UK hospitals. Exclusions were insertion or musculotendinous junction injuries, major leg injury or deformity, diabetes, platelet or haematological disorder, medication with systemic corticosteroids, anticoagulation therapy treatment, and other contraindicating conditions. Participants were randomized via a central online system 1:1 to PRP or placebo injection. The main outcome measure was Achilles Tendon Rupture Score (ATRS) at two years via postal questionnaire. Other outcomes were pain, recovery goal attainment, and quality of life. Analysis was by intention-to-treat. RESULTS: A total of 230 participants were randomized, 114 to PRP and 116 to placebo. Two-year questionnaires were sent to 216 participants who completed a six-month questionnaire. Overall, 182/216 participants (84%) completed the two-year questionnaire. Participants were aged a mean of 46 years (SD 13.0) and 25% were female (57/230). The majority of participants received the allocated intervention (219/229, 96%). Mean ATRS scores at two years were 82.2 (SD 18.3) in the PRP group (n = 85) and 83.8 (SD 16.0) in the placebo group (n = 92). There was no evidence of a difference in the ATRS at two years (adjusted mean difference -0.752, 95% confidence interval -5.523 to 4.020; p = 0.757) or in other secondary outcomes, and there were no re-ruptures between 24 weeks and two years. CONCLUSION: PRP injection did not improve patient-reported function or quality of life two years after acute Achilles tendon rupture compared with placebo. The evidence from this study indicates that PRP offers no patient benefit in the longer term for patients with acute Achilles tendon rupture.Medical Research Council (MRC)National Institute for Health and Care Research (NIHR)Scar Free Foundatio