bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Model for the Fast Determination of Modal Sound Transmission of Large Rectangular Opening
Authors: Li Jiazhu , Zhang Rui , Chen Shen , Li Can , Chen Jian 
Published: March 2020

Abstract
The existence of openings affects the sound insulation performance of structures significantly. The determination of sound transmission through large rectangular openings is often time-consuming, because of the large number of modes, especially if there is a need to go to high frequencies. A model is proposed and detailed based on three-dimensional wave equations, the transfer matrix method, and modal superposition. The viscous and thermal boundary layer effects have been concerned; hence, the model accuracy for narrow slits was improved. The computational effort is significantly decreased by neglecting the cross-modal sound transmission. The accuracy of this model is validated by comparing it with the existing model, the measurement, and the acoustic finite element method. The study of sound transmission behavior of higher-order modes is performed. The modal sound transmission is predicted and compared for several modes. The phenomenon that is different from that of the plane wave situation is found and discussed.
Experimental Analysis of an Ultra-Compact Combustor Powered Turbine Engine
Authors: Bohan Brian T. , Polanka Marc D. 
Published: March 2020

Abstract
The innovative ultra-compact combustor (UCC) is an alternative to traditional turbine engine combustors and has been shown to reduce the combustor length and offer potential improvements in combustion efficiency. Prior UCC configurations featured a circumferential combustion cavity positioned around the outside diameter (OD) of the engine. This configuration would be difficult to implement in a vehicle with a small, fixed diameter and had difficulty migrating the hot combustion products at the OD radially inward across an axial core flow to present a uniform temperature distribution to the first turbine stage. This study draws from preliminary computational analysis which enabled experimental testing of a new UCC configuration that featured a smaller diameter circumferential cavity that exhausted axially into a dilution zone positioned just upstream of the nozzle guide vanes. The combustor was sized as a replacement burner for the JetCat P90 RXi small-scale turbine engine and fit inside the engine casing. This combustor configuration achieved a 33% length reduction compared to the stock JetCat combustor and achieved comparable engine performance across a limited operating range. Self-sustained engine operation was achieved with a rotating compressor and turbine making this study the first to achieve operation of a UCC-powered turbine engine.
Extended Environmental Contour Methods for Long-Term Extreme Response Analysis of Offshore Wind Turbines1
Authors: Chen Xiaolu , Jiang Zhiyu , Li Qinyuan , Li Ye , Ren Nianxin 
Published: March 2020

AbstractEnvironmental contour method is an efficient method for predicting the long-term extreme response of offshore structures. The traditional environmental contour is obtained using the joint distribution of mean wind speed, significant wave height, and spectral peak period. To improve the accuracy of traditional environmental contour method, a modified method was proposed considering the non-monotonic aerodynamic behavior of offshore wind turbines. Still, the modified method assumes constant wind turbulence intensity. In this paper, we extend the existing environmental contour methods by considering the wind turbulence intensity as a stochastic variable. The 50-year extreme responses of a monopile-based offshore wind turbine are compared using the extended environmental contour methods and the full long-term method. It is found that both the environmental contour method and the modified environmental contour method, with the wind turbulence intensity included as an individual variable, give more accurate predictions compared with those without. Using the full long-term method as a benchmark, this extended approach could reduce the nonconservatism of the environmental contour method and conservatism of the modified environmental contour method. This approach is effective under wind-dominated or combined wind-wave loading conditions, but may not be as important for wave-dominated conditions.
Study protocol for SFX-01 after subarachnoid haemorrhage (SAS): a multicentre randomised double-blinded, placebo controlled trial
Authors: Zolnourian Ardalan H , Franklin Stephen , Galea Ian , Bulters Diederik Oliver 
Published: March 2020

IntroductionSubarachnoid haemorrhage (SAH) from a ruptured cerebral aneurysm carries high morbidity and mortality. Despite huge advances in techniques to secure the aneurysm, there has been little progress in the treatment of the deleterious effects of the haemorrhage.Sulforaphane is an Nrf2 inducer with anti-oxidant and anti-inflammatory properties. It has been shown to improve clinical outcome in experimental models of SAH, but is unstable. SFX-01 (Evgen Pharma) is a novel composition comprised of synthetic sulforaphane stabilised within an α-cyclodextrin complex. On ingestion, the complex releases sulforaphane making SFX-01 an ideal vehicle for delivery of sulforaphane.Methods and analysisThe objective of the study is to assess the safety, pharmacokinetics and efficacy of SFX-01. This is a prospective, multicentre, randomised, double-blind placebo-controlled trial in patients aged 18–80 years with aneurysmal subarachnoid haemorrhage in the previous 48 hours. 90 patients will be randomised to receive SFX-01 (300 mg) or placebo two times per day for up to 28 days.Safety will be assessed using blood tests and adverse event reporting.Pharmacokinetics will be assessed based on paired blood and cerebrospinal fluid (CSF) sulforaphane levels on day 7. A subgroup will have hourly samples taken during 6 hours post-dosing on days 1 and 7. Pharmacodynamics will be assessed by haptoglobin and malondialdehyde levels, and maximum flow velocity of middle cerebral artery will be measured by transcranial Doppler ultrasound.Clinical outcomes will be assessed at days 28, 90 and 180 with modified Rankin Scale, Glasgow Outcome Score, SAH Outcome Tool, Short Form-36, Brain Injury Community Rehabilitation Outcome Scales and Check List for Cognitive and Emotional consequences following stroke. MRI at 6 months including quantitative susceptibility mapping and volumetric T1 will measure iron deposition and cortical volume.Safety, CSF sulforaphane concentration and middle cerebral artery flow velocity will be primary outcomes and all others secondary.Ethics and disseminationEthical approval was obtained from South Central Hampshire A committee. Outcomes of the trial will be submitted for publication in a peer-reviewed journal.Trial registration numberNCT02614742.
Effect of face-to-face verbal feedback compared with no or alternative feedback on the objective workplace task performance of health professionals: a systematic review and meta-analysis
Authors: Johnson Christina Elizabeth , Weerasuria Mihiri P , Keating Jennifer L 
Published: March 2020

ObjectiveVerbal face-to-face feedback on clinical task performance is a fundamental component of health professions education. Experts argue that feedback is critical for performance improvement, but the evidence is limited. The aim of this systematic review was to investigate the effect of face-to-face verbal feedback from a health professional, compared with alternative or no feedback, on the objective workplace task performance of another health professional.DesignSystematic review and meta-analysis.MethodsWe searched the full holdings of Ovid MEDLINE, CENTRAL, Embase, CINAHL and PsycINFO up to 1 February 2019 and searched references of included studies. Two authors independently undertook study selection, data extraction and quality appraisal. Studies were included if they were randomised controlled trials investigating the effect of feedback, in which health professionals were randomised to individual verbal face-to-face feedback compared with no feedback or alternative feedback and available as full-text publications in English. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations approach. For feedback compared with no feedback, outcome data from included studies were pooled using a random effects model.ResultsIn total, 26 trials met the inclusion criteria, involving 2307 participants. For the effect of verbal face-to-face feedback on performance compared with no feedback, when studies at high risk of bias were excluded, eight studies involving 392 health professionals were included in a meta-analysis: the standardised mean difference (SMD) was 0.7 (95% CI 0.37 to 1.03; p<0.001) in favour of feedback. The calculated SMD prediction interval was −0.06 to 1.46. For feedback compared with alternative feedback, studies could not be pooled due to substantial design and intervention heterogeneity. All included studies were summarised, and key factors likely to influence performance were identified including components within feedback interventions, instruction and practice opportunities.ConclusionsVerbal face-to-face feedback in the health professions may result in a moderate to large improvement in workplace task performance, compared with no feedback. However, the quality of evidence was low, primarily due to risk of bias and publication bias. Further research is needed. In particular, we found a lack of high-quality trials that clearly reported key components likely to influence performance.Trial registration numberCRD42017081796.
Neighbourhood effects on obesity: scoping review of time-varying outcomes and exposures in longitudinal designs
Authors: Letarte Laurence , Pomerleau Sonia , Tchernof André , Biertho Laurent , Waygood Edward Owen D , Lebel Alexandre 
Published: March 2020

Context and objectivesNeighbourhood effect research on obesity took off in the early 2000s and was composed of mostly cross-sectional observational studies interested in various characteristics of the built environment and the socioeconomic environment. To limit biases related to self-selection and life course exposures, many researchers apply longitudinal designs in their studies. Until now, no review has specifically and exclusively examined longitudinal studies and the specific designs of these studies. In this review, we intend to answer the following research question: how are the temporal measurements of contextual exposure and obesity outcomes integrated into longitudinal studies that explore how neighbourhood-level built and socioeconomic environments impact adult obesity?DesignA systematic search strategy was designed to address the research question. The search was performed in Embase, Web of Science and PubMed, targeting scientific papers published before 1 January 2018. The eligible studies reported results on adults, included exposure that was limited to neighbourhood characteristics at the submunicipal level, included an outcome limited to obesity proxies, and reported a design with at least two exposure measurements or two outcome measurements.ResultsThis scoping review identified 66 studies that fit the eligibility criteria. A wide variety of neighbourhood characteristics were also measured, making it difficult to draw general conclusions about associations between neighbourhood exposure and obesity. We applied a typology that classified studies by whether exposure and outcome were measured as varying or fixed. Using this typology, we found that 32 studies reported both neighbourhood exposure and obesity outcomes that were varying in time; 28 reported varying outcomes but fixed exposures; and 6 had fixed outcomes and varying exposures.ConclusionOur typology illustrates the variety of longitudinal designs that were used in the selected studies. In the light of our results, we make recommendations on how to better report longitudinal designs and facilitate comparisons between studies.
Management of haemorrhoids: protocol of an umbrella review of systematic reviews and meta-analyses
Authors: Chen Min , Tang Tai-Chun , He Tao-Hong , Du Yong-Jun , Qin Di , Zheng Hui 
Published: March 2020

IntroductionThe prevalence of haemorrhoidal diseases was high in general population, and many treatments are proposed for the management of haemorrhoids. The treatments include conservative and surgical interventions; the credibility and strength of current evidence of their effectiveness are not comprehensively evaluated. We aim to evaluate the credibility of systematic reviews and meta-analyses that assess the effectiveness of the treatments for haemorrhoidal diseases through an umbrella review.Methods and analysisWe will search Ovid Medline, Embase, Cochrane library and Web of Science from inception to March 2020 without any language restriction. We will include meta-analyses that examine the effectiveness of treatments in the management of haemorrhoids. Two reviewers will independently screen the titles and abstracts of retrieved articles, and they will extract data from the included meta-analyses. For each meta-analysis, we will estimate the effect size of a treatment through the random-effect model and the fixed-effect model, and we will evaluate between-study heterogeneity (Cochrane’s Q and I2statistics) and small-study effect (Egger’s test); we will also estimate the evidence of excess significance bias. Evidence of each treatment will be graded according to prespecified criteria. Methodological quality of each meta-analysis will be evaluated by using Assessment of Multiple Systematic Reviews 2. The corrected cover area method will be used to assess the impact of overlap in reviews on the findings of the umbrella review.Ethics and disseminationWe will present the results of the umbrella review at conferences and publish the final report in a peer-reviewed journal. The umbrella review does not require ethical approval.PROSPERO registration numberCRD42019140702.
Investigation of an extensive outbreak of HIV infection among children in Sindh, Pakistan: protocol for a matched case–control study
Authors: Siddiqui Amna R , Ali Nathwani Apsara , Abidi Syed H , Mahmood Syed Faisal , Azam Iqbal , Sawani Sobiya , Kazi Abdul M , Hotwani Aneeta , Memon Sikander Ali , Soomro Jamila , Shaikh Saqib Ali , Achakzai Baseer , Saeed Quaid , Simms Victoria , Khan Palwasha , Ferrand Rashida , Mir Fatima 
Published: March 2020

IntroductionIn April 2019, 14 children were diagnosed with HIV infection by a private healthcare provider in Larkana district, Sindh province, Pakistan. Over the next 3 months, 930 individuals were diagnosed with HIV, >80% below 16 years, the largest ever outbreak of HIV in children in Pakistan. In this protocol paper, we describe research methods for assessing likely modes of HIV transmission in this outbreak and investigate spatial and molecular epidemiology.Methods and analysisA matched case–control study will be conducted with 406 cases recruited. Cases will be children aged below 16 years registered for care at the HIV treatment centre at Shaikh Zayed Children Hospital in Larkana City. Controls will be children who are HIV-uninfected (confirmed by a rapid HIV test) matched 1:1 by age (within 1 year), sex and neighbourhood. Following written informed consent from the guardian, a structured questionnaire will be administered to collect data on sociodemographic indices and exposure to risk factors for parenteral, vertical and sexual (only among those aged above 10 years) HIV transmission. A blood sample will be collected for hepatitis B and C serology (cases and controls) and HIV lineage studies (cases only). Mothers of participants will be tested for HIV to investigate the possibility of mother-to-child transmission. Conditional logistic regression will be used to investigate the association of a priori defined risk factors with HIV infection. Phylogenetic analyses will be conducted. Global positioning system coordinates of participants’ addresses will be collected to investigate concordance between the genetic and spatial epidemiology.Ethics and disseminationEthical approval was granted by the Ethics Review Committee of the Aga Khan University, Karachi. Study results will be shared with Sindh and National AIDS Control Programs, relevant governmental and non-governmental organisations, presented at national and international research conferences and published in international peer-reviewed scientific journals.
Improving the documentation quality of point-of-care ultrasound scans in the emergency department
Authors: Aziz Shadman , Bottomley James , Mohandas Vasant , Ahmad Arif , Morelli Gemma , Thenabadu Sam 
Published: March 2020

A point-of-care ultrasound scan (POCUS) is a core element of the Royal College of Emergency Medicine (RCEM) specialty training curriculum. However, POCUS documentation quality can be poor, especially in the time-pressured environment of the emergency department (ED). A survey of 10 junior ED clinicians at the Princess Royal University Hospital (PRUH) found that total POCUS documentation was as low as 38% in some examinations.This quality improvement project aimed to increase the coverage and quality of POCUS documentation in the ED. This was done by using a plan-do-study-act (PDSA) regime to improve the quality of POCUS documentation from the original baseline to 80%. There were three discreet PDSA cycles and the interventions included improving education and training about POCUS documentation and the introduction of an original proforma, which incorporated six minimum requirements for POCUS documentation as per the joint RCEM and Royal College of Radiologists (RCR) guidelines for POCUS documentation (patient details, indications, findings, conclusions, signature and date).The project team audited the quality of all documented scans in the resuscitation department of the PRUH against the RCEM/RCR guidelines at baseline and following three discrete PDSA cycles. This was done over an 8-week period, spanning 696 attendances to the resuscitation area of the ED and 42 documented POCUS examinations.Quality recording of the six RCEM/RCR elements of POCUS documentation was poor at baseline but improved following three successful PDSA cycles. There was a demonstrated improvement in five of six documentation elements: patient details on POCUS documentation increased from 53.3% to the 66.7%, indication from 60.0% to 66.7%, conclusion from 13.0% to 83.0%, signature from 86.7% to 100.0% and date from 46.7% to 66.7%.These results suggest that the introduction of a proforma and a vigorous education strategy are effective ways to improve the quality of documentation of ED POCUS.
Epidemiological, clinical and virological characteristics of 74 cases of coronavirus-infected disease 2019 (COVID-19) with gastrointestinal symptoms
Authors: Jin Xi , Lian Jiang-Shan , Hu Jian-Hua , Gao Jianguo , Zheng Lin , Zhang Yi-Min , Hao Shao-Rui , Jia Hong-Yu , Cai Huan , Zhang Xiao-Li , Yu Guo-Dong , Xu Kai-Jin , Wang Xiao-Yan , Gu Jue-Qing , Zhang Shan-Yan , Ye Chan-Yuan , Jin Ci-Liang , Lu Ying-Feng , Yu Xia , Yu Xiao-Peng , Huang Jian-Rong , Xu Kang-Li , Ni Qin , Yu Cheng-Bo , Zhu Biao , Li Yong-Tao , Liu Jun , Zhao Hong , Zhang Xuan , Yu Liang , Guo Yong-Zheng , Su Jun-Wei , Tao Jing-Jing , Lang Guan-Jing , Wu Xiao-Xin , Wu Wen-Rui , Qv Ting-Ting , Xiang Dai-Rong , Yi Ping , Shi Ding , Chen Yanfei , Ren Yue , Qiu Yun-Qing , Li Lan-Juan , Sheng Jifang , Yang Yida 
Published: March 2020

ObjectiveThe SARS-CoV-2-infected disease (COVID-19) outbreak is a major threat to human beings. Previous studies mainly focused on Wuhan and typical symptoms. We analysed 74 confirmed COVID-19 cases with GI symptoms in the Zhejiang province to determine epidemiological, clinical and virological characteristics.DesignCOVID-19 hospital patients were admitted in the Zhejiang province from 17 January 2020 to 8 February 2020. Epidemiological, demographic, clinical, laboratory, management and outcome data of patients with GI symptoms were analysed using multivariate analysis for risk of severe/critical type. Bioinformatics were used to analyse features of SARS-CoV-2 from Zhejiang province.ResultsAmong enrolled 651 patients, 74 (11.4%) presented with at least one GI symptom (nausea, vomiting or diarrhoea), average age of 46.14 years, 4-day incubation period and 10.8% had pre-existing liver disease. Of patients with COVID-19 with GI symptoms, 17 (22.97%) and 23 (31.08%) had severe/critical types and family clustering, respectively, significantly higher than those without GI symptoms, 47 (8.14%) and 118 (20.45%). Of patients with COVID-19 with GI symptoms, 29 (39.19%), 23 (31.08%), 8 (10.81%) and 16 (21.62%) had significantly higher rates of fever >38.5°C, fatigue, shortness of breath and headache, respectively. Low-dose glucocorticoids and antibiotics were administered to 14.86% and 41.89% of patients, respectively. Sputum production and increased lactate dehydrogenase/glucose levels were risk factors for severe/critical type. Bioinformatics showed sequence mutation of SARS-CoV-2 with m6A methylation and changed binding capacity with ACE2.ConclusionWe report COVID-19 cases with GI symptoms with novel features outside Wuhan. Attention to patients with COVID-19 with non-classic symptoms should increase to protect health providers.
Preoperative detection of malignancy in fine-needle aspiration cytology (FNAC) smears with indeterminate cytology (Bethesda III, IV) by a combined molecular classifier
Authors: Titov Sergei , Demenkov Pavel S , Lukyanov Sergei A , Sergiyko Sergei V , Katanyan Gevork A , Veryaskina Yulia A , Ivanov Mikhail K 
Published: March 2020

AimsAnalysis of molecular markers in addition to cytological analysis of fine-needle aspiration (FNA) samples is a promising way to improve the preoperative diagnosis of thyroid nodules. Previously, we have developed an algorithm for the differential diagnosis of thyroid nodules by means of a small set of molecular markers. Here, we aimed to validate this approach using FNA cytology samples of Bethesda categories III and IV, in which preoperative detection of malignancy by cytological analysis is impossible.MethodsA total of 122 FNA smears from patients with indeterminate cytology (Bethesda III: 13 patients, Bethesda IV: 109 patients) were analysed by real-time PCR regarding the preselected set of molecular markers (theBRAFV600E mutation, normalised concentrations ofHMGA2mRNA, 3 microRNAs, and the mitochondrial/nuclear DNA ratio). The decision tree–based classifier was used to discriminate between benign and malignant tumours.ResultsThe molecular testing detected malignancy in FNA smears of indeterminate cytology with 89.2% sensitivity, 84.6% positive predictive value, 92.9% specificity and 95.2% negative predictive value; these characteristics are comparable with those of more complicated commercial tests. Residual risk of malignancy for the thyroid nodules that were shown to be benign by this molecular method did not exceed the reported risk of malignancy for Bethesda II histological diagnosis. Analytical-accuracy assessment revealed required nucleic-acid input of ≥5 ng.ConclusionsThe study shows feasibility of preoperative differential diagnosis of thyroid nodules of indeterminate cytology using a small panel of molecular markers of different types by a simple PCR-based method using stained FNA smears.