bluuebunny/crossref_metadata_2025_split huggingface dataset:
Counter-Propagating Rotating Stall of Vaned Diffuser in a Centrifugal Compressor Near Design Condition
Authors: Du Yu , Dou Hua-Shu , Lu Fuan 
Published: October 2020

Abstract
Unstable flow in the vaned diffuser of a centrifugal compressor stage near design condition is investigated by numerical simulation. The simulation is performed with the unsteady Navier–Stokes equations and three different turbulence models. Comparisons of the characteristic curves of the stage have been carried out between simulation and experiment, and good agreement is obtained. The fluctuation signals near the interface between the impeller and the diffuser are also quantitatively analyzed from macro and micro scales under a series of mass flow conditions. The simulation results show that an abnormal counter-propagating rotating stall in the vaned diffuser is detected near design condition. The rotating stall displays that four stall cells near the shroud side of the vaned diffuser propagate slowly at a rate of approximately 0.675% of the impeller rotating frequency along the opposite direction of the impeller rotation. The propagation speed increases as the mass flow decreases. The generation and propagation mechanisms of this phenomenon are elucidated, respectively. It is found that flow separation near the diffuser shroud side is produced due to the spanwise variation of flow angles near the impeller exit, which leads to the generation of stall cells in the diffuser. The circumferential propagation of the rotating stall cells is propelled by the accumulation and release of the fluid energy from impeller passages. Further studies show that this phenomenon can be restrained by modifying the installation angle of diffuser vanes.
Buoyancy Control Device Enabled by Reversible Proton Exchange Membrane Fuel Cells for Fine Depth Control
Authors: Yazji Jalal , Keow Alicia Li Jen , Zaidi Hamza , Torres Luke T. , Leroy Christopher , Chen Zheng 
Published: October 2020

Abstract
Fine buoyancy control is essential for underwater robots to maintain neutral buoyancy despite dynamic changes in environmental conditions. This paper introduces a novel buoyancy control system that uses reversible fuel cells (RFC) as a mass-to-volume engine to change the underwater robots' buoyancy. The RFC uses both the water electrolysis process and fuel cell reaction to produce and consume gases in a flexible bladder for volume change. Unlike conventional actuators such as motors and pistons used in buoyancy control, this mechanism is silent, compact, and energy-efficient. A dynamic model that described the dynamics of the RFC-enabled buoyancy change is presented. Then, a proportional-derivative (PD) controller is designed to position the device at any depth underwater. A prototype device is built to validate the dynamic model and the performance of the feedback controller. Experimental results demonstrate a fine depth control performance with 4 cm accuracy and 90 s settling time. The compact buoyancy design is readily integrable with small underwater robots for fine depth change allowing the robots to save actuation energy.
Evaluating the Shinumo-Sespe drainage connection: Arguments against the “old” (70–17 Ma) Grand Canyon models for Colorado Plateau drainage evolution
Authors: Karlstrom Karl E. , Jacobson Carl E. , Sundell Kurt E. , Eyster Athena , Blakey Ron , Ingersoll Raymond V. , Mulder Jacob A. , Young Richard A. , Beard L. Sue , Holland Mark E. , Shuster David L. , Winn Carmen , Crossey Laura 
Published: October 2020

AbstractThe provocative hypothesis that the Shinumo Sandstone in the depths of Grand Canyon was the source for clasts of orthoquartzite in conglomerate of the Sespe Formation of coastal California, if verified, would indicate that a major river system flowed southwest from the Colorado Plateau to the Pacific Ocean prior to opening of the Gulf of California, and would imply that Grand Canyon had been carved to within a few hundred meters of its modern depth at the time of this drainage connection. The proposed Eocene Shinumo-Sespe connection, however, is not supported by detrital zircon nor paleomagnetic-inclination data and is refuted by thermochronology that shows that the Shinumo Sandstone of eastern Grand Canyon was &gt;60 °C (∼1.8 km deep) and hence not incised at this time. A proposed 20 Ma (Miocene) Shinumo-Sespe drainage connection based on clasts in the Sespe Formation is also refuted. We point out numerous caveats and non-unique interpretations of paleomagnetic data from clasts. Further, our detrital zircon analysis requires diverse sources for Sespe clasts, with better statistical matches for the four “most-Shinumo-like” Sespe clasts with quartzites of the Big Bear Group and Ontario Ridge metasedimentary succession of the Transverse Ranges, Horse Thief Springs Formation from Death Valley, and Troy Quartzite of central Arizona. Diverse thermochronologic and geologic data also refute a Miocene river pathway through western Grand Canyon and Grand Wash trough. Thus, Sespe clasts do not require a drainage connection from Grand Canyon or the Colorado Plateau and provide no constraints for the history of carving of Grand Canyon. Instead, abundant evidence refutes the “old” (70–17 Ma) Grand Canyon models and supports a &lt;6 Ma Grand Canyon.
Effectiveness of pelvic floor muscle training with and without electromyographic biofeedback for urinary incontinence in women: multicentre randomised controlled trial
Authors: Hagen Suzanne , Elders Andrew , Stratton Susan , Sergenson Nicole , Bugge Carol , Dean Sarah , Hay-Smith Jean , Kilonzo Mary , Dimitrova Maria , Abdel-Fattah Mohamed , Agur Wael , Booth Jo , Glazener Cathryn , Guerrero Karen , McDonald Alison , Norrie John , Williams Louise R , McClurg Doreen 
Published: October 2020

AbstractObjectiveTo assess the effectiveness of pelvic floor muscle training (PFMT) plus electromyographic biofeedback or PFMT alone for stress or mixed urinary incontinence in women.DesignParallel group randomised controlled trial.Setting23 community and secondary care centres providing continence care in Scotland and England.Participants600 women aged 18 and older, newly presenting with stress or mixed urinary incontinence between February 2014 and July 2016: 300 were randomised to PFMT plus electromyographic biofeedback and 300 to PFMT alone.InterventionsParticipants in both groups were offered six appointments with a continence therapist over 16 weeks. Participants in the biofeedback PFMT group received supervised PFMT and a home PFMT programme, incorporating electromyographic biofeedback during clinic appointments and at home. The PFMT group received supervised PFMT and a home PFMT programme. PFMT programmes were progressed over the appointments.Main outcome measuresThe primary outcome was self-reported severity of urinary incontinence (International Consultation on Incontinence Questionnaire-urinary incontinence short form (ICIQ-UI SF), range 0 to 21, higher scores indicating greater severity) at 24 months. Secondary outcomes were cure or improvement, other pelvic floor symptoms, condition specific quality of life, women’s perception of improvement, pelvic floor muscle function, uptake of other urinary incontinence treatment, PFMT self-efficacy, adherence, intervention costs, and quality adjusted life years.ResultsMean ICIQ-UI SF scores at 24 months were 8.2 (SD 5.1, n=225) in the biofeedback PFMT group and 8.5 (SD 4.9, n=235) in the PFMT group (mean difference −0.09, 95% confidence interval −0.92 to 0.75, P=0.84). Biofeedback PFMT had similar costs (mean difference £121 ($154; €133), −£409 to £651, P=0.64) and quality adjusted life years (−0.04, −0.12 to 0.04, P=0.28) to PFMT. 48 participants reported an adverse event: for 23 this was related or possibly related to the interventions.ConclusionsAt 24 months no evidence was found of any important difference in severity of urinary incontinence between PFMT plus electromyographic biofeedback and PFMT alone groups. Routine use of electromyographic biofeedback with PFMT should not be recommended. Other ways of maximising the effects of PFMT should be investigated.Trial registrationISRCTN57756448.
From words to actions: systematic review of interventions to promote sexual and reproductive health of persons with disabilities in low- and middle-income countries
Authors: Hameed Shaffa , Maddams Alexander , Lowe Hattie , Davies Lowri , Khosla Rajat , Shakespeare Tom 
Published: October 2020

IntroductionPersons with disabilities have the same sexual and reproductive health and rights (SRHR) as non-disabled persons. Yet they face numerous barriers in their access to sexual and reproductive health services and their rights are often not met. Evidence on SRHR for persons with disabilities is sparse, particularly evaluations of interventions demonstrating ‘what works.’ This systematic review assessed interventions to promote SRHR for persons with disabilities in low- and middle-income countries.MethodsWe searched for qualitative, quantitative or mixed method observational studies representing primary research, published between 2010 and 2019, using MEDLINE, Embase, PubMed, Global Health and CINAHL Plus. Search strings were compiled for different elements of SRHR and for all forms of disability. 24,919 records were screened, leading to over 380 relevant papers, most of which were descriptive, focussing on needs and barriers to SRHR needs being fulfilled. Of the 33 full-text articles assessed for eligibility, 18 were included in the synthesis. All included studies were assessed for bias and quality of evidence, using STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) and RATS (relevance, appropriateness, transparency andsoundness) tools. Among the 16 interventions (from 18 articles), 25% had low risk of bias, 31% had moderate risk of bias and 44% had high risk of bias. Data analysis used narrative synthesis; a method suited for systematic reviews with heterogeneous studies. We used Levesque healthcare access model to analyse the focus of interventions.Results11 interventions were from upper middle-income settings; two from lower-income settings; only one operated in rural areas. Interventions addressed intellectual impairment (6), visual impairment (6), hearing impairment (4), mental health conditions (2) and physical impairments (2). Most interventions (15/16) focus on information provision and awareness raising. We could not identify any intervention promoting access to maternal health, family planning and contraception, or safe abortion for people with disabilities.ConclusionThis systematic review has highlighted stark gaps in evidence. More rigorous evaluations are needed.
Cost-effectiveness of internet-based vestibular rehabilitation with and without physiotherapy support for adults aged 50 and older with a chronic vestibular syndrome in general practice
Authors: van Vugt Vincent A , Bosmans Judith E , Finch Aureliano P , van der Wouden Johannes C , van der Horst Henriëtte E , Maarsingh Otto R 
Published: October 2020

ObjectivesTo evaluate the cost-effectiveness of stand-alone and blended internet-based vestibular rehabilitation (VR) in comparison with usual care (UC) for chronic vestibular syndromes in general practice.DesignEconomic evaluation alongside a three-armed, individually randomised controlled trial.Setting59 Dutch general practices.Participants322 adults, aged 50 years and older with a chronic vestibular syndrome.InterventionsStand-alone VR consisted of a 6-week, internet-based intervention with weekly online sessions and daily exercises. In blended VR, this intervention was supplemented with face-to-face physiotherapy support. UC group participants received usual general practice care without restrictions.Main outcome measuresSocietal costs, quality-adjusted life years (QALYs), Vertigo Symptom Scale—Short Form (VSS-SF), clinically relevant response (≥3 points VSS-SF improvement).ResultsMean societal costs in both the stand-alone and blended VR groups were statistically non-significantly higher than in the UC group (mean difference (MD) €504, 95% CI −1082 to 2268; and €916, 95% CI −663 to 2596). Both stand-alone and blended VR groups reported non-significantly more QALYs than the UC group (MD 0.02, 95% CI −0.00 to 0.04; and 0.01, 95% CI −0.01 to 0.03), and significantly better VSS-SF Scores (MD 3.8 points, 95% CI 1.7 to 6.0; and 3.3 points, 95% CI 1.3 to 5.2). For stand-alone VR compared with UC, the probability of cost-effectiveness was 0.95 at a willingness-to-pay ratio of €24 161/QALY, €600/point improvement in VSS-SF and €8000/clinically relevant responder in VSS-SF. For blended VR versus UC, the probability of cost-effectiveness was 0.95 at a willingness-to-pay ratio of €123 335/QALY, €900/point improvement in VSS-SF and €24 000/clinically relevant responder in VSS-SF.ConclusionStand-alone and blended internet-based VR non-significantly increased QALYs and significantly reduced vestibular symptoms compared with UC, while costs in both groups were non-significantly higher. Stand-alone VR has the highest probability to be cost-effective compared with UC.Trial registration numberThe Netherlands Trial Register NTR5712.
Publication bias in pediatric emergence delirium: a cross-sectional analysis of ClinicalTrials.gov and ClinicalTrialsRegister.eu
Authors: Meyburg Jochen , Ries Markus 
Published: October 2020

ObjectivesEmergence delirium (ED) is a frequent and potentially serious complication of general anaesthesia in children. Although there are various treatment strategies, no general management recommendations can be made. Selective reporting of study results may impair clinical decision-making. We, therefore, analysed whether the results of completed registered clinical studies in patients with paediatric ED are publicly available or remain unpublished.DesignCross-sectional analysis.SettingClinicalTrials.gov and ClinicalTrialsRegister.eu.Participants and outcome measuresWe determined the proportion of published and unpublished studies registered at ClinicalTrials.gov and ClinicalTrialsRegister.eu that were marked as completed by 1st September 2018. The major trial and literature databases were used to search for publications. In addition, the study investigators were contacted directly. For published trials, time to publication was calculated as the difference in months between study completion date and publication date.ResultsOf the 44 registered studies on paediatric ED, only 24 (54%) were published by September 2019. Published trials contained data from n=2556 patients, whereas n=1644 patients were enrolled in unpublished trials. Median time to publication was 19 months. Studies completed in recent years were published faster, but still only 9 of 24 trials were published within 12 months of completion.ConclusionThere is a distinct publication gap in clinical research in paediatric ED that may have an impact on meta-analyses and clinical practice.
Ghost ileostomy versus conventional loop ileostomy in patients undergoing low anterior resection for rectal cancer (DRKS00013997): protocol for a randomised controlled trial
Authors: Hüttner Felix J , Probst Pascal , Mihaljevic André , Contin Pietro , Dörr-Harim Colette , Ulrich Alexis , Schneider Martin , Büchler Markus W , Diener Markus K , Knebel Phillip 
Published: October 2020

IntroductionAnastomotic leakage is the most important complication in colorectal surgery occurring in up to 20% after low anterior rectal resection. Therefore, a diverting ileostomy is usually created during low anterior resection to protect the anastomosis or rather to diminish the consequences in case of anastomotic leakage. The so-called virtual or ghost ileostomy is a pre-stage ostomy that can be easily exteriorised, if anastomotic leakage is suspected, in order to avoid the severe consequences of anastomotic leakage. On the other hand, an actual ileostomy can be avoided in patients, who do not develop anastomotic leakage.Methods and analysisThe GHOST trial is a randomised controlled pilot trial comparing ghost ileostomy with conventional loop ileostomy in patients undergoing low anterior resection with total mesorectal excision for rectal cancer. After screening for eligibility and obtaining informed consent, a total of 60 adult patients are included in the trial. Patients are intraoperatively randomised to the trial groups in a 1:1 ratio after assuring that none of the intraoperative exclusion criteria are present. The main outcome parameter is the comprehensive complication index as a measure of safety. Further outcomes include specific complications, stoma-related complications, complications of ileostomy closure, frequency of transformation of ghost ileostomy into conventional ileostomy, frequency of terminal ostomy creation, proportion of patients with an ostomy at 6 months after index surgery, anorectal function (Wexner score) and quality of life assessed by the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 and CR29 questionnaires. Follow-up for each individual patient will be 6 months.Ethics and disseminationThe GHOST trial has been approved by the Medical Ethics Committee of Heidelberg University (reference number S-694/2017). If the intervention proves to be safe, loop ileostomy could be spared in a large proportion of patients, thus also avoiding stoma-related complications and a second operation (ileostomy closure) with its inherent complications in these patients.Trial registration numberGerman Clinical Trials Registry (DRKS00013997); Universal Trial Number: U1111-1208-9742.
Industry ties and evidence in public comments on the FDA framework for modifications to artificial intelligence/machine learning-based medical devices: a cross sectional study
Authors: Smith James Andrew , Abhari Roxanna E , Hussain Zain , Heneghan Carl , Collins Gary S , Carr Andrew J 
Published: October 2020

ObjectivesTo determine the extent and disclosure of financial ties to industry and use of scientific evidence in comments on a US Food and Drug Administration (FDA) regulatory framework for modifications to artificial intelligence/machine learning (AI/ML)-based software as a medical device (SaMD).DesignCross-sectional study.SettingWe searched all publicly available comments on the FDA ‘Proposed Regulatory Framework for Modifications to Artificial Intelligence/Machine Learning (AI/ML)-Based Software as a Medical Device (SaMD)—Discussion Paper and Request for Feedback’ from 2 April 2019 to 8 August 2019.Main outcome measuresThe proportion of articles submitted by parties with financial ties to industry, disclosing those ties, citing scientific articles, citing systematic reviews and meta-analyses, and using a systematic process to identify relevant literature.ResultsWe analysed 125 comments submitted on the proposed framework. 79 (63%) comments came from parties with financial ties; for 36 (29%) comments, it was not clear and the absence of financial ties could only be confirmed for 10 (8%) comments. No financial ties were disclosed in any of the comments that were not from industry submitters. The vast majority of submitted comments (86%) did not cite any scientific literature, just 4% cited a systematic review or meta-analysis and no comments indicated that a systematic process was used to identify relevant literature.ConclusionsFinancial ties to industry were common and undisclosed, and scientific evidence, including systematic reviews and meta-analyses, were rarely cited. To ensure regulatory frameworks best serve patient interests, the FDA should mandate disclosure of potential conflicts of interest (including financial ties) in comments, encourage the use of scientific evidence, and encourage engagement from non-conflicted parties.
Associations between hormonal contraception use, sociodemographic factors and mental health: a nationwide, register-based, matched case–control study
Authors: Toffol Elena , But Anna , Heikinheimo Oskari , Latvala Antti , Partonen Timo , Haukka Jari 
Published: October 2020

ObjectivesSociodemographic and mental health characteristics are associated with contraceptive choices. We aimed to describe the sociodemographic, reproductive and mental health characteristics of all fertile-aged women in Finland who used hormonal contraception (HC) in 2017.DesignA nationwide, register-based study.SettingAll women living in Finland in 2017; data from the Care Register of Health Care, Medical Birth Register, Population Register Centre, Prescription Centre, Register of Induced Abortions.ParticipantsAll women aged 15–49 with one redeemed HC prescription in 2017 (n=294 356), and a same-sized, age-matched and residence-matched, control group of non-users.OutcomesRates of HC use; associations between HC use and mental disorders, sociodemographic and reproductive characteristics.Results25.8% of women aged 15–49 years used HC. Women with the lowest socioeconomic levels had lower odds of using HC than women with upper-level statuses (OR, 95% CI students: 0.97, 0.94 to 0.99; entitled to pension: 0.66, 0.63 to 0.69; other: 0.87, 0.85 to 0.89; unknown: 0.90, 0.85 to 0.90). Women with the highest education (secondary: 1.46, 1.43 to 1.48; tertiary: 1.64, 1.58 to 1.70; academic: 1.60, 1.56 to 1.63) and income (second quarter: 1.57, 1.54 to 1.60; third quarter: 1.85, 1.82 to 1.89; fourth quarter: 2.01, 1.97 to 2.06), and unmarried women had higher odds of using HC than women with the lowest education and income levels, and married (0.61, 0.60 to 0.62), divorced (0.86, 0.84 to 0.88), widowed (0.73, 0.65 to 0.83) or other marital status women (0.26, 0.22 to 0.30).Parous women (0.70, 0.69 to 0.71), those with previous induced abortion(s) (0.91, 0.89 to 0.92) or recent eating (0.68, 0.62 to 0.75) or personality (0.89, 0.79 to 0.97) disorders had lower odds of HC use. Absolute risk differences between women with and without mental disorders ranged from 3.1% (anxiety disorders) to 10.1% (eating disorders).ConclusionsA quarter of the fertile-aged women use HC in Finland. Sociodemographic disparities persist in relation to HC use, although of small effect size. HC use is less common among women suffering from severe to moderate psychiatric disorders, especially eating disorders.
Progression/remission of COVID-19: data-driven recommendations for repeating SARS-CoV-2 nucleic acid amplification tests
Authors: Williams Nathan , Idriss Reed , Dodge Jessica , Barasch Samuel 
Published: October 2020

AimsThis short study was performed to better understand the time frame associated with changes in SARS-CoV-2 nucleic acid testing and provide recommendations for repeat testing. Recommendations are useful as little guidance is available for repeat testing in patients being followed expectantly for changes in disease.MethodsA review of laboratory data of tests for SARS-CoV-2 nucleic acid was performed selecting patients who had changing results. Time between changes in test results was determined to provide guidance for repeat testing.ResultsThe Interquartile Range (IQR) of data for patients who had a negative to positive change in laboratory testing (progression) was 6–16 days (median=9 days). The IQR of data for patients who had a positive to negative change in test results (remission) was 9–21 days (median=14 days).ConclusionBecause sampling of the nares or nasopharynx can be variable, repeat testing should be performed swiftly when symptomatic patients are negative. The data in this short study vary widely, so authors recommend repeat testing during a period of time associated with the IQR or median (see results above).