bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generation Mechanism of Broadband Whoosh Noise in an Automotive Turbocharger Centrifugal Compressor
Authors: Dehner Rick , Sriganesh Pranav , Selamet Ahmet , Miazgowicz Keith 
Published: May 2021

Abstract
The present study focuses on the acoustics of a turbocharger centrifugal compressor from a spark-ignition internal combustion engine. Whoosh noise is typically the primary concern for this type of compressor, which is loosely characterized by a broadband sound elevation in the 4–13 kHz range. To identify the generation mechanism of broadband whoosh noise, the present study combines three approaches: three-dimensional (3D) computational fluid dynamics (CFD) predictions, experiments, and modal decomposition of 3D CFD results. After establishing the accuracy of predictions, flow structures and time-resolved pressures are closely examined in the vicinity of the main blade leading edge. This reveals the presence of rotating instabilities that may interact with the rotor blades to generate noise. An azimuthal modal decomposition is performed on the predicted pressure field to determine the number of cells and the frequency content of these rotating instabilities. The strength of the rotating instabilities and the frequency range in which noise is generated as a consequence of the rotor-rotating instability interaction correspond well with the qualitative trend of the whoosh noise that is measured several duct diameters upstream of the rotor blades. The variation of the whoosh frequency range between low and high rotational speeds is interpreted through this analysis. It is also found that the whoosh noise primarily propagates along the duct as acoustic azimuthal modes. Hence, the inlet duct diameter, which governs the cut-off frequency for multi-dimensional acoustic modes, determines the lower frequency bound of the broadband noise.
Study on Lifted Flame Stabilization Under Different Background Pressures
Authors: Qin Qiushi , Wu Zhijun , Ferrari Alessandro 
Published: May 2021

Abstract
A numerical experimental investigation is presented for a steady methane lifted flame and a nonreaction jet flow in a co-flow of hot combustion products from lean premixed air-hydrogen combustion. The main objective has been to analyze the dependence of methane jet flame stability on the background pressure: a pressurized vitiated co-flow burner (PVCB) has been used to study the methane lifted flame and nonreaction jet flow under different background pressures (1–1.5 bars). The lifted flame is characterized by a liftoff height, which has been measured with a high-speed camera, and a central jet flow defined by the jet velocity, which has been measured by means of a high-sensitivity Schlieren imaging system. The experimental results show that the liftoff height decreases for an increment in the background pressure (from 1 to 1.5 bar at 1073 K) and in the co-flow temperature (from 1058 K to 1118 K at 1 bar). The standard deviation of the liftoff height also reduces for an increase in either the background pressure or the co-flow temperature, which indicates that the liftoff height is more stable at higher background pressures and co-flow temperatures. As far as the experimental tests on the nonreaction jet flow is concerned, the jet velocity becomes extinct faster as the background pressure rises, which is consistent with the decrease in the liftoff height as the background pressure grows. The evolution of the jet velocity has been proved to be another important factor that affects the liftoff height under different background pressures (physical factor), in addition to the fuel autoignition delay (chemical factor). The simulation data led with a Reynolds-averaged Navier–Stokes (RANS)/probability density function (PDF) model show that an increment in the background pressure makes the temperatures increase and induces a brighter yellow part of lifted flame, which leads to more soot production. This proves that the flame is not completely premixed. On the other hand, the Schlieren images of the non-reaction jet flow highlight that the flame is partially premixed, since the edge of the jet is not well defined, as the jet penetration increases with time. The liftoff height values of the flame in the numerical simulations were found to be generally higher than those measured in the corresponding experiments. This discrepancy was caused by an appreciable radiation heat loss at the thermocouple. A correlation was therefore developed for the thermocouple temperature measurement in order to correct the inaccuracy.
OP0267 SHORT-TERM CHANGES IN THE RADIOGRAPHIC EXTENT OF INTERSTITIAL LUNG DISEASE PREDICT LONG-TERM MORTALITY IN SYSTEMIC SCLEROSIS
Authors: Volkmann E. , Tashkin D. , Roth M. , Goldin J. , Kim G. 
Published: May 2021

Background:The forced vital capacity (FVC) is often used as the primary endpoint in treatment trials for systemic sclerosis-interstitial lung disease (SSc-ILD), and while trends in FVC have been found to predict mortality in SSc-ILD,1,2 FVC measurements are also influenced by extra-pulmonary factors, such as cutaneous sclerosis, myopathy, and patient/technician effort. Change in the quantitative extent of ILD (QILD) on HRCT is an emerging endpoint in clinical trials; however, no studies have evaluated whether changes in radiographic extent ILD predict mortality in SSc-ILD.Objectives:To evaluate the relationship between changes QILD in the whole lung (WL) and long-term survival in patients who participated in the Scleroderma Lung Study (SLS) I3 and II.4Methods:SLS I randomized 158 SSc-ILD patients to 12 months of cyclophosphamide (CYC) vs. placebo. SLS II randomized 142 SSc-ILD patients to 12 months of CYC, followed by 12 months of placebo vs. 24 months of mycophenolate (MMF). QILD-WL scores were calculated at baseline and 12 months (SLS I) and 24 months (SLS II). Participants were followed for up to 12 (SLS I) and 8 years (SLS II). Using landmark survival analysis, Kaplan Meier curves were generated to compare survival between participants who had worse QILD-WL scores (≥2% increase) and those who had stable/improved QILD-WL scores (<2% increase). Cox proportional hazards models were created to determine whether the change in QILD-WL scores predicted survival after controlling other variables found to affect survival in these cohorts.Results:Among all the SLS I and II participants, 82 and 90 had follow up HRCT scans, respectively, and were included in these analyses. SLS I participants with an increase in QILD-WL scores of ≥2% at 12 months had significantly worse long-term survival (P= 0.01; Figure). Similarly, SLS II participants with an increase in QILD-WL scores of ≥2% at 24 months had significantly worse long-term survival (P= 0.019; Figure). After adjusting for baseline FVC, age, and modified Rodnan skin score (mRSS), an increase in QILD-WL scores of ≥2% remained associated with worse long-term survival in SLS I (trend: P=0.089) and SLS II (P=0.014).Conclusion:Progression of the radiographic extent of ILD of ≥2% was associated with worse long-term survival in two independent SSc cohorts with extensive long-term follow up. The findings provide compelling evidence that short-term changes in the radiographic extent of ILD may serve as a surrogate endpoint for mortality in patients with SSc.References:[1]Goh NS, et al. Arthritis Rheum 2017.[2]Volkmann ER, et al. Ann Rheum Dis 2019.[3]Tashkin DP, et al. NEJM 2006.[4]Tashkin DP, et al. Lancet Resp Med 2016.Disclosure of Interests:Elizabeth Volkmann Consultant of: Boehringer Ingelheim, Grant/research support from: Forbius, Corbus, Donald Tashkin: None declared, Michael Roth Grant/research support from: Genentech/Roche, Jonathan Goldin: None declared, Grace Kim: None declared
POS1179 POST COVID ARTHRITIS; REACTIVE ARTHRITIS OR RHEUMATIC DISEASE FLARE OR BOTH
Authors: Fayed F. , Abdelkarim E. 
Published: May 2021

Background:Reactive arthritis (ReA) is an emerging arthritis after viral infection especially respiratory and gastrointestinal related viruses. In 2020, SARS-COV2 virus is sweeping worldwide with diverse symptoms and prolonged post-Covid manifestations in which are arthralgia and myalgia are frequently present for days and even months. Interestedly, arthritis in covid era is a part of ReA or a flare of autoimmune disease, it is challenging.(1)Objectives:Our objective was to determine the frequency of musculoskeletal symptoms with SARS-COV2 virus and after recovery as well as its relation to autoimmune diseases flares.Methods:A Prospective study was done on 241 patients who admitted to the Rheumatology clinic from March 2020 to January 2021, complaining from new onset of musculoskeletal symptoms. Detailed history, Examination of systems including Musculoskeletal, laboratory investigation, past history of existing rheumatic disease, and history of infection with covid 19.Results:Among 241 patients with median age 34.4, 36.92% had an existing Rheumatic disease while 63.08% are not. Moreover, 39% of patients had a post history with covid 19 within weeks. The most frequent Musculoskeletal symptoms are myalgia (74.56%), arthralgia (69.36%), and arthritis (10.78%). Furthermore, ReA (Post covid arthritis) accounted (2.07%) especially monoarthritis of Ankle (68.75%) while rheumatic diseases flares (24.48%) as well as new onset rheumatic diseases (39.68%). (p ≤0.001) patients of ReA improved on NSAID and intrarticular injection of glucocorticosteroid.Conclusion:Covid 19 is one of environmental triggers for development of rheumatic disease as well as reactive arthritis post viral infections. ReA is commonly affected the Ankle joint mainly monoarthritis and had improved on oral NSAID and intrarticular injection of Glucocorticosteroid.References:[1]Schett, G., Manger, B., Simon, D. et al. COVID-19 revisiting inflammatory pathways of arthritis. Nat Rev Rheumatol16, 465–470 (2020).Disclosure of Interests:None declared.
POS1127 ULTRASOUND ASSESSMENT OF GOUT LESIONS IN AN ALGERIAN POPULATION WITH ASYMPTOMATIC HYPERURICEMIA
Authors: Bengana B. , Ladjouze-Rezig A. , Ayoub S. , Raaf N. B. , Aimeur C. , Boukabous A. , Lefkir S. 
Published: May 2021

Background:Hyperuricemia is a common biological abnormality, often clinically asymptomatic. However, it can announce a gout and be linked to many diseases such as metabolic syndrome, high blood pressure or kidney disease.In fact, the majority of learned societies do not recommend any urate lowering therapy (ULT) as long as the hyperuricemia remains asymptomatic. But it turns out that part of the population with asymptomatic hyperuricemia (AH) develops a gout after a few years particularly with genetic predisposition, but also on certain risk factors that need to be confirmed.By this way, musculoskeletal ultrasound (MUS) can detect “asymptomatic gout” by visualizing signs of urate deposits (UD) in subjects with AH.Objectives:Our main objective is already to estimate the prevalence of specific signs of gout in Algerian population with AH and assess the factors exposing to UD.Methods:This is a descriptive cross-sectional study from January 2017 to February 2019, with the recruitment of subjects with AH and serum urate level > 60 mg / L, who do not take any ULT and have not associated any chronic inflammatory rheumatism, where we performed a MUS of the knees, metatarsophalangeal joints MTP1, MTP2 and metacarpophalangeal joint MCP2 and MCP3 with the Achilles, patellar and quadricipital tendons.Results:We retained 258 subjects with AH, 132 women and 126 men (sex ratio = 0.95), the mean age was 59 years, the mean body mass index (BMI) was 28.4 kg / m2, 42 patients were under diuretics, 37 patients reported being on low-dose of aspirin 100 mg daily.The mean rate of serum urate levels was 78 ± 10 mg / L, the prevalence of UD found at the MUS was 22% (n = 58), among them 36 % (21/58) had a sign of the double contour DC on the MTP1 and 29% (17/58) on the knee, 7% (4/58) had tophi on the MTP1 and 3% (2/58) had urate aggregates. The factors reported to be linked to UD in the sample were: the male gender (p = 0.0016); the high uric acid level (p= 0.0355); BMI (p = 0.0427); taking diuretics for women (p= 0.0002).Conclusion:Through this work, it is clear that elementary ultrasound lesions related to gout disease are common in a population with AH and concerned one fifth of subjects in our study with a higher risk in men and subjects with obesity and high uric acid level, but also in women taking diuretics. These results need to be enhanced with a randomized controlled study in order to better determine the predisposing factors for gout in any subject with AH.Disclosure of Interests:None declared.
POS0916 SAFETY OF BIOLOGIC TREATMENTS IN SOLID ORGAN TRANSPLANT RECIPIENTS: A SYSTEMATIC REVIEW
Authors: Frederic M. , Delphine W. V. , Prati C. , Wendling D. , Verhoeven F. 
Published: May 2021

Background:The management of a broad spectrum of autoimmune/inflammatory diseases has been transformed with the development of biological treatments. However, little is known about their use in solid organ transplant recipients, a group of patients with high risk of serious infections and malignancies.Objectives:To evaluate complications occurring with biologic treatments in solid-organ transplant recipients.Methods:A systematic review of the literature was performed on the PubMed including Medline, Embase and Cochrane databases, up to 01/10/2020, to identify published case reports/series regarding the use of biologic treatments in solid organ transplant recipients in the context of chronic inflammatory diseases. Collected data were patient’s characteristics (age, sex, reason for transplantation, antirejection regimen, type of biological treatment used, autoimmune/inflammatory disease treated, time between transplantation and biotherapy initiation, treatment duration) and their reported complications (deaths, infections, malignancies, graft dysfunction).Results:55 papers were included, representing 177 patients (131 liver, 42 kidney, 3 heart, and 1 liver-kidney transplant recipients). Inflammatory bowel diseases represented largely the most common indication of biologic treatment initiation (80.2%), followed by rheumatic diseases (7.3%), hereditary periodic fever syndromes (6.2%) and psoriasis (5.1%). Anti-TNFα were mainly used (81.4%) before anti- α4β7 integrin Vedolizumab (23.7%) and anti-IL1R Anakinra (7.3%). 25/177 patients had several lines of different treatments. Median treatment duration was 13.5 months. Infections occurred in 48 patients (27.1%) through 76 recorded flares (mostly bacterial 68.4% and viral 19.7%). No therapeutic or epidemiological factor was associated with the occurrence of an infection. 16 patients (9.0%) developed malignancies, especially colorectal (4 cases, 2.3%) and skin cancers (4 cases, 2.3%) or Post-transplantation lymphoproliferative disorders (3 cases, 1.7%). Acute graft rejections occurred in 5 patients (2.8%), mostly in kidney transplants (4/5). Among a total of 177 patients, 6 deaths were identified (3.4%).Conclusion:This review gathers, to our knowledge, the largest number of published case series/reports about the use of biological treatments in solid organ transplant recipients, providing data about their safety. Caution must be taken about eventual publication bias and the necessity of further head-to-head analysis comparing complications occurring in solid organ transplant recipients cohorts with and without biologic treatments.Disclosure of Interests:None declared
POS0045 LEAST SIGNIFICANT CHANGE IN BONE DENSITOMETRY IN PATIENTS WITH OBESITY
Authors: Claire D. , Geoffroy M. , Kanagaratnam L. , Isabelle C. , Hittinger A. , Loïs B. , Clément C. , Salmon J. H. 
Published: May 2021

Background:Dual energy X-ray absoprtiometry is the reference method to mesure bone mineral density (1). Loss of bone mineral density is significant if it exceeds the least significant change. The threshold value used in general population is 0,03 g/cm2 (2). Patients with obesity are known for having a higher bone mineral density due to metabolism and physiopathology characteristics (3,4).Objectives:The aim of our study was to determine the least significant change in bone densitometry in patients with obesity.Methods:We conducted an interventionnal study in 120 patients with obesity who performed a bone densitometry. We measured twice the bone mineral density at the lumbar spine, the femoral neck and the total hip in the same time (5,6). We determined the least significant change in bone densitometry from each pair of measurements, using the Bland and Altman method. We also determined the least significant change in bone densitometry according to each stage of obesity.Results:The least significant change in bone densitometry in patients with obesity is 0,046g/cm2 at the lumbar spine, 0.069 g/cm2 at the femoral neck and 0.06 g/cm2 at the total hip.Conclusion:The least significant change in bone densitometry in patients with obesity is higher than in general population. These results may improve DXA interpretation in this specific population, and may personnalize their medical care.References:[1]Lees B, Stevenson JC. An evaluation of dual-energy X-ray absorptiometry and comparison with dual-photon absorptiometry. Osteoporos Int. mai 1992;2(3):146-52.[2]Briot K, Roux C, Thomas T, Blain H, Buchon D, Chapurlat R, et al. Actualisation 2018 des recommandations françaises du traitement de l’ostéoporose post-ménopausique. Rev Rhum. oct 2018;85(5):428-40.[3]Shapses SA, Pop LC, Wang Y. Obesity is a concern for bone health with aging. Nutr Res N Y N. mars 2017;39:1-13.[4]Savvidis C, Tournis S, Dede AD. Obesity and bone metabolism. Hormones. juin 2018;17(2):205-17.[5]Roux C, Garnero P, Thomas T, Sabatier J-P, Orcel P, Audran M, et al. Recommendations for monitoring antiresorptive therapies in postmenopausal osteoporosis. Jt Bone Spine Rev Rhum. janv 2005;72(1):26-31.[6]Ravaud P, Reny JL, Giraudeau B, Porcher R, Dougados M, Roux C. Individual smallest detectable difference in bone mineral density measurements. J Bone Miner Res. août 1999;14(8):1449-56.Disclosure of Interests:None declared.
POS0957 THE PREVALENCE AND FACTORS RELATED TO SLEEP APNOEA IN ANKYLOSING SPONDYLITIS
Authors: Forsblad-D’elia H. , Wiginder A. , Sahlin-Ingridsson C. , Geijer M. , Franklin K. , Blomberg A. 
Published: May 2021

Background:An increased prevalence of obstructive sleep apnoea (OSA) has been suggested in ankylosing spondylitis (AS), but few controlled studies have been performed.Objectives:We thus aimed to study the prevalence of OSA in patients with AS compared to controls and to study if disease-related and non-disease-related factors were determinants of OSA in AS patients.Methods:One hundred and fifty-five patients with AS were included in the Backbone study that investigates severity and comorbidities in AS. Controls were recruited from the Swedish CardioPulmonary bioImage Study (SCAPIS). Participants were asked to be examined with a home sleep-monitoring device during one night’s sleep to evaluate the presence of OSA. For each AS patient, 45-70 years, four controls were matched for sex, age, weight and height. OSA was defined as an apnoea-hypopnea-index ≥5 events/hour.Results:In total, 63/155(40.6%) patients with AS were examined with a home sleep-monitoring device out of which 46 patients were 45-70 years and therefore matched (mean age 57.2±7.5years, 30(65.2%) men) with 179 controls (mean age 57.2±4.5years, 123(68.7%) men). Twenty-two out of 46(47.8%) patients with AS vs. 91/179(50.8%) controls had OSA, p=0.72. No differences measurements evaluating OSA were noted in AS vs. controls. In logistic regression analysis, based on all 63 examined AS-patients, several AS-related variables were associated with OSA but after adjusting for age and sex, only higher age and BMI, remained to be significant determinants of OSA, Table 1.Table 1.Univariable and age- and sex-adjusted logistic regression analyses with obstructive sleep apnoea as dependent variable in 63 patients with ankylosing spondylitis.VariablesUnivariable logistic regression analyses, Odds Ratio (95%CI)PAge- and sex-adjusted logistic regression analyses,Odds Ratio (95%CI)PSex, male1.9(0.6-5.5)0.251.5(0.4-4.8)0.53Age1.1(1.0-1.2)0.0021.1(1.0-1.2)0.002BMI1.4(1.1-1.7)0.0011.6(1.2- 2.2)0.001Duration of symptoms1.1(1.0-1.1)0.0281.0(0.9-1.1)0.79BASMI1.9(1.3-2.9)0.0021.5(0.9 -2.5)0.87BASFI1.4(1.0-2.0)0.0381.3(0.9-2.0)0.88≥1 Syndesmophyte3.9(1.3-12.2)0.0173.0(0.8-11.3)0.10mSASSS1.0(1.0-1.1)0.0471.0(0.98-1.05)0.25Metabolic syndrome4.3(1.5-12.9)0.0081.4(0.3-6.6)0.69Epworth Sleep Scale1.2(1.0-1-3)0.0231.2(1.0-1.4)0.29Conclusion:In this case-control study, patients with AS did not have a higher prevalence of OSA compared to controls. AS patients with OSA had higher BMI and were older compared to patients without OSA.Disclosure of Interests:None declared.
Economic evaluation of robot-assisted training versus an enhanced upper limb therapy programme or usual care for patients with moderate or severe upper limb functional limitation due to stroke: results from the RATULS randomised controlled trial
Authors: Fernandez-Garcia Cristina , Ternent Laura , Homer Tara Marie , Rodgers Helen , Bosomworth Helen , Shaw Lisa , Aird Lydia , Andole Sreeman , Cohen David , Dawson Jesse , Finch Tracy , Ford Gary , Francis Richard , Hogg Steven , Hughes Niall , Krebs H I , Price Christopher , Turner Duncan , Van Wijck Frederike , Wilkes Scott , Wilson Nina , Vale Luke 
Published: May 2021

ObjectiveTo determine whether robot-assisted training is cost-effective compared with an enhanced upper limb therapy (EULT) programme or usual care.DesignEconomic evaluation within a randomised controlled trial.SettingFour National Health Service (NHS) centres in the UK: Queen’s Hospital, Barking, Havering and Redbridge University Hospitals NHS Trust; Northwick Park Hospital, London Northwest Healthcare NHS Trust; Queen Elizabeth University Hospital, NHS Greater Glasgow and Clyde; and North Tyneside General Hospital, Northumbria Healthcare NHS Foundation Trust.Participants770 participants aged 18 years or older with moderate or severe upper limb functional limitation from first-ever stroke.InterventionsParticipants randomised to one of three programmes provided over a 12-week period: robot-assisted training plus usual care; the EULT programme plus usual care or usual care.Main economic outcome measuresMean healthcare resource use; costs to the NHS and personal social services in 2018 pounds; utility scores based on EQ-5D-5L responses and quality-adjusted life years (QALYs). Cost-effectiveness reported as incremental cost per QALY and cost-effectiveness acceptability curves.ResultsAt 6 months, on average usual care was the least costly option (£3785) followed by EULT (£4451) with robot-assisted training being the most costly (£5387). The mean difference in total costs between the usual care and robot-assisted training groups (£1601) was statistically significant (p<0.001). Mean QALYs were highest for the EULT group (0.23) but no evidence of a difference (p=0.995) was observed between the robot-assisted training (0.21) and usual care groups (0.21). The incremental cost per QALY at 6 months for participants randomised to EULT compared with usual care was £74 100. Cost-effectiveness acceptability curves showed that robot-assisted training was unlikely to be cost-effective and that EULT had a 19% chance of being cost-effective at the £20 000 willingness to pay (WTP) threshold. Usual care was most likely to be cost-effective at all the WTP values considered in the analysis.ConclusionsThe cost-effectiveness analysis suggested that neither robot-assisted training nor EULT, as delivered in this trial, were likely to be cost-effective at any of the cost per QALY thresholds considered.Trial registration numberISRCTN69371850.