bluuebunny/crossref_metadata_2025 huggingface dataset:
Large Eddy Simulation of Flow Over a Hemispherical Obstacle Within a Cylindrical Tube
Authors: Sharma Amit , Ghia Urmila , Turkevich Leonid A.
Published: October 2020

Motivated by recent experiments on the dustiness of nanoscale powders, this research addresses the modeling of powder aerosolization within the Venturi Dustiness Test (VDT) apparatus. As a first step in such modeling, we investigate the flow over a hemispherical (powder) hill, at the operating Reynolds number Re ∼ 20,000, in the powder holding tube attached to the VDT. The powder holding tube is idealized as a cylindrical tube, obstructed by a hemispherical (powder) hill.

The upstream flow field is characterized by the presence of a horse-shoe vortex, formed due to the separation of the boundary layer from the wall of the tube. A stagnation point occurs at the lower front surface of the bump. Strong near-wall vorticity is generated midway up the bump, and the flow is separated near the top of the bump. Kelvin-Helmholtz vortices are produced due to the strong shear-layer vorticity, and these then travel downstream with the flow. The upstream near-wall flow is dominated by a horseshoe vortex forming a necklace pushed out into the wake area. The flow detaches from the bump at the separation line, leading to vortex ‘roll-up’. These rolled-up vortices merge with the horseshoe vortices to form a large entangled hairpin vortex. The arch-type vortices shed with a frequency consistent with the Strouhal estimate fSt ∼ 6700 Hz.
A Phase Field Method for Numerical Simulation of Boiling Heat Transfer
Authors: Wang Zhicheng , Zheng Xiaoning , Karniadakis George
Published: October 2020

The Cahn-Hilliard phase field method for two-phase flow has gained particular attention due to its unique features including its flexibility for complex morphological and topological changes, the intrinsic property of conserving mass, and the natural approach to account for the surface tension. The essential idea of the method is to use a phase field function to describe the two-phase system, while a thin smooth transition layer (interfacial area) connects the two immiscible fluids, where the value of phase field function varies continuously. The application of phase field method to two-phase flows has become more widespread recently, but to the best of our knowledge, very little progress has been made for the method being applied to the two-phase flows with phase change. This includes evaporation, condensation and boiling, which plays an important role in enhanced heat transfer in power electronics, energy, and aerospace engineering. In previous work, in order to face the challenge of large density contrast and high Reynolds number of practical engineering problems, we developed a stabilized phase field method that can handle two-phase flow with density ratio over 1000, at high Reynolds number over 10,000, and applied the method to simulate slug initiation in a long circular pipe. In this paper, inspired by the boiling model widely used in the level-set method, we propose a new boiling model that assumes that boiling takes place in the whole interfacial layer. The method is then used to solve the non-solenoidal Navier-Stokes equations. The boiling model is validated by simulating a vapor bubble growing in super-heated liquid. For this case, the growth rate of the bubble has an analytical solution, and it is used as a benchmark case in volume of fluid (VOF) and level-set methods extensively. For three different refrigerants, namely water, R134a and HFE7100, our phase field method with the boiling model can obtain accurate simulation results. Moreover, the method and model are applied to predict the three-dimensional boiling heat transfer in a rectangular micro-channel that contains a water vapor bubble with various inlet super-heat conditions. We found that the predicted bubble shape is very similar to that visualized in existing experiment. From our simulation of boiling flow using the phase field method, We have found that the required mesh resolution for the phase field method is comparable with that of VOF and level-set methods.
Experimental Validation of Fluid-Structure Interaction Co-Simulations Using ANSYS via Wind Tunnel Testing of Cantilevered Plate
Authors: Shepard Thomas G. , Schneider Kyle , Baxter Sarah , Schwartz William
Published: October 2020

Validation of numerical simulations is a key step in gaining confidence in the fidelity of computational models for a given application. These simulations take on additional complexity in fluid structure interactions when the body being studied experiences flow-induced deformation. In this study, experiments are conducted on a cantilevered aluminum plate mounted in a wind tunnel. Experimentally, deflections are measured using Digital Image Correlation and axial bending strains are measured using strain gages and. These values are compared to a coupled fluid-structure interaction simulation, which co-simulated the structural (Lagrangian FEA) and fluid (Navier-Stokes CFD) computational methods. Within the simulations, FEA parameters including mesh size, mapping method, and mesh type were varied; CFD parameters that were varied include turbulence theory, mesh sizing, inflation layer, mapping method, and Courant Number. Values were varied to study their effects on the simulation solution, as well as to ensure mesh independence of the solution relative to both simulation domains. Experiments were conducted on an Aluminum (6061-T6) plate measuring 152.4 × 50.8 × 0.61 mm. The plate was positioned in the wind tunnel at two different angles relative to the oncoming flow and Reynolds numbers of 98,000–247,000 were considered. The numerical simulation demonstrates agreement with DIC displacements and good agreement with measured strains with deflections up to ∼ 11 mm. Future steps are discussed.
Investigation of the Flow Instabilities of a Low Specific Speed Pump-Turbine: Part 1 — Experimental and Numerical Analysis
Authors: Deniz Sabri , Del Rio Armando , von Burg Martin , Tiefenthaler Manuel
Published: October 2020

This is the first part of a two-part paper focusing on the flow instabilities of low-specific pump turbines. In this part, results of the CFD simulations and experiments of the research carried out on a low specific speed model pump-turbine at HSLU (Lucerne University of Applied Sciences) Switzerland are presented.

The requirements of a stable and reliable pump-turbine operation under continuously expanding operating ranges, challenges the hydraulic design and requires new developments. Previous research at the HSLU [1] analyzed the instabilities of a medium specific speed (i.e. nq = 45) pump turbine. This paper presents the results of experimental (model pump-turbine at the test rig) and numerical (CFD) investigations of the pump-turbine instabilities of a low specific speed (nq = 25) pump-turbine in the turbine operating mode in the region of S-shaped characteristics (that is where the pump-turbine is synchronized and oscillations may occur during load rejection). The four-quadrant characteristics of a low specific speed model pump-turbine with two similar runners differentiating in the size (diameter) are measured. Testing of both runners with the same guide vane system provided information about the effects of the increased vaneless space (the distance between the guide vanes and runner) on the pump-turbine performance and stability both in turbine- and pump operating modes.

A CFD methodology by using different numerical approaches and applying several turbulence models is developed in order to accurately predicting the characteristics of the reversible pump-turbines in the S-shaped region (speed no load conditions) as well as analyzing the flow features especially at off-design conditions. This CFD model is validated against the experimental data at 6° and 18° guide vane openings in turbine operating mode.

With the measured data of the unsteady pressure measurements and detailed investigation of unstable ranges on the pump-turbine characteristics, flow instabilities in the low-specific speed model pump-turbine are analyzed. Relevant frequencies such as rotating stall, steady and unsteady vortex formations are determined. Based on the analysis of the experimental data and CFD results focusing especially on the flow features in the vaneless space and at the runner inlet, the onset and development of the flow instabilities are explored.
Numerical Investigation and Performance Characterization of Oscillating Foil Energy Harvesting
Authors: Pannell James , Walters D. Keith
Published: October 2020

Oscillating foil energy harvesting devices are increasingly being considered as a sustainable energy alternative, especially in rivers and tidal areas. This paper applies CFD to an oscillating foil power generation device in order to explore the effects of pitching amplitude, the ratio of heaving amplitude to chord length, and the reduced frequency to the energy harvesting efficiency. Ansys Fluent 17.2 was used for this study, and the results are compared to experimental results that have been previously documented in the open literature. Configurations examined included pitching amplitudes of 65, 70, 75, and 80 degrees; heaving ratios of 0.4, 0.6, and 0.8; and reduced frequencies of 0.1, 0.12, 0.14, and 0.16. Results seems to indicate that the optimal reduced frequency is related to the heaving ratio, with the pitching amplitude only creating slight variations in the power produced by the foil. In the data, configurations with a heaving ratio of 0.4 have highest efficiency at reduced frequencies of either 0.14 or 0.16, but efficiency remains high at both points, which indicates the possibility of a peak in between the two points. Configurations with heaving ratio of 0.6 peak at reduced frequency 0.14 with a significant drop off at reduced frequency of 0.16. Finally, configurations with a heaving ratio of 0.8 show a peak at 0.12 reduced frequency and a significant drop at 0.14 and 0.16. These results suggest that OFEH devices can be effectively optimized for different and potentially varying operating conditions that may be encountered during practical implementation of OFEH technology.
A Solution for Experimental Modeling the Axial Fans With High Efficiency and Reduced Noise
Authors: Radulescu Victorita
Published: October 2020

Present paper describes some experimental results obtained for modeling an axial fan with newly designed blade profiles, having high efficiency, low vibrations and noise. The axial fan was firstly designed by computational method, during a research project with our industrial partner SAVEB SA. One of the company objectives is represented by the production of the axial industrial fans, dedicated to different users to eliminate the smoke and the air pollutants from industrial halls, according to their specific needs. In the beginning, are presented some aspects of the theoretical aspects used in the numerical modeling for designing the rotor blades. Some considerations concerning the selection of the incidence angles of 10°, 15°, and 20° are mentioned. The profiles were selected from the recommended schemes, for different industrial applications, as the industrial halls for the air or gas circulation without corrosive, abrasive, or toxic agents, metallic dust, or with crowding/sticking suspensions contents. For this type of axial fan, the content of suspensions should not exceed 50 mg/m3. Further is presented the experimental stand, in conformity with actual standards, STAS 7466-84 and DIN 24163, equipped with a hydrometer with an error less than 3%, barometer with an error less than 1 mm Hg, stroboscope and tachometer with an error less 0,5% from the total rotation velocity, two voltmeters, with an error less 0,5, two wattmeters, etc. For the experimental tests was selected a fan with a diameter of 630 mm, which as standard execution has a maximum efficiency of 56%, in six different constructive variants: a rotor with 12 profiles and directory device with 11 blades, with 6 blades and directory device, etc. As the first variant of the rotor’s profiles has been used two solutions for the realization as two technological options, both of them tested in the laboratory. There are detailed some schemes adopted for the measurements and tests, and finally the adopted solution for measuring different characteristic parameters like efficiency, noise, and vibrations produced by the axial fan. Next are illustrated part of the measurement reports and the corresponding charts. Of the total amount of experimental results were selected for measuring scheme III and IV for their optimum energetic characteristics and high efficiency. All four diagrams are presented for both selected solutions used in the realization of the fan rotor blades. Finally, some conclusions and references are presented.
Flow Boiling on Heterogeneous Wetting Surface in a Vertical Narrow Microchannel
Authors: Lin Yuhao , Li Junye , Zhou Kan , Li Wei , Sheng Kuang , Shao Shuai
Published: October 2020

The micro structured surfaces have significant impact on the flow patterns and heat transfer mechanisms during the flow boiling process. The hydrophobic surface promotes bubble nucleation while the hydrophilic surface supplies liquid to a heating surface, thus there is a trade-off between a hydrophobic and a hydrophilic surface. To examine the effect of heterogeneous wetting surface on flow boiling process, an experimental investigation of flow boiling in a rectangular vertical narrow microchannel with the heterogeneous wetting surface was conducted with deionized water as the working fluid. The heat transfer characteristics of flow boiling in the microchannel was studied and the flow pattern was photographed with a high-speed camera. The onset of flow boiling and heat transfer coefficient were discussed with the variation of heatfluxes and mass fluxes, the trends of which were analyzed along with the flow patterns. During the boiling process, the dominated heat transfer mechanism was nucleate boiling, with numerous nucleate sites between the hydrophilic/hydrophobic stripes and on the hydrophobic ones. In the meantime, after the merged bubbles were constrained by the channel walls, it would be difficult for them to expand towards upstream since they were restricted by the contact line between hydrophilic/hydrophobic stripes, thereby reduce the flow instability and achieve remarkable heat transfer performance.
Multi-resolution estimation of the interference spectrum per pair of modes in the frequency domain
Authors: Gao Wei , Li Xiaolei , Wang Haozhong
Published: October 2020

A multi-resolution estimation method for interference spectrum separation from a one-dimensional broadband acoustic intensity is presented in this letter. The key of the proposed method is the recursion reconstruction and singular value decomposition of a 2×L Hankel matrix, which is constructed by a broadband intensity data sequence of length L + 1. Numerical simulation results show that this method can be used to achieve the zero-phase-shift estimation of each interference spectrum without any prior environmental information.
Distribution of the two-point product of complex amplitudes in the fully saturated scattering regime
Authors: Wilson D. Keith , Ostashev Vladimir E. , Pettit Chris L.
Published: October 2020

This Letter considers probability density functions (pdfs) involving products of the complex amplitudes observed at two points (which may, in general, involve separations in space, time, or frequency) in conditions of fully saturated scattering. First, the pdf is derived for the product of the complex amplitude at one point with the conjugate of the complex amplitude at another point. It is shown that the real and imaginary parts of this product each have a variance gamma pdf. Second, expressions are derived for several joint pdfs involving complex amplitude products and powers at two points.
ROS-responsive chitosan-SS31 prodrug for AKI therapy via rapid distribution in the kidney and long-term retention in the renal tubule
Authors: Liu Di , Shu Gaofeng , Jin Feiyang , Qi Jing , Xu Xiaoling , Du Yan , Yu Hui , Wang Jun , Sun Mingchen , You Yuchan , Zhu Minxia , Chen Meixuan , Zhu Luwen , Shen Qiying , Ying Xiaoying , Lou Xuefang , Jiang Saiping , Du Yongzhong
Published: October 2020

An SS31 prodrug improved AKI therapy via rapid distribution in the kidney and long-term retention in the renal tubule.
Carriage of Extended-Spectrum-Beta-Lactamase- and AmpC Beta-Lactamase-Producing Escherichia coli Strains from Humans and Pets in the Same Households
Authors: Toombs-Ruane Leah J. , Benschop Jackie , French Nigel P. , Biggs Patrick J. , Midwinter Anne C. , Marshall Jonathan C. , Chan Maggie , Drinković Dragana , Fayaz Ahmed , Baker Michael G. , Douwes Jeroen , Roberts Mick G. , Burgess Sara A.
Published: October 2020

Enterobacteriaceae
that produce extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases (ACBLs) are important pathogens and can cause community-acquired illnesses, such as urinary tract infections (UTIs). Fecal carriage of these resistant bacteria by companion animals may pose a risk for transmission to humans. Our work evaluated the sharing of ESBL- and ACBL-producing
E. coli
isolates between humans and companion animals. We found that in some households, dogs carried the same strain of ESBL-producing
E. coli
as the household member with a UTI. This suggests that transmission events between humans and animals (or vice versa) are likely occurring within the home environment and, therefore, the community as a whole. This is significant from a health perspective, when considering measures to minimize community transmission, and highlights that in order to manage community spread, we need to consider interventions at the household level.
Bacterial Cell Wall Quality Control during Environmental Stress
Authors: Mueller Elizabeth A. , Levin Petra Anne
Published: October 2020

Nearly all bacteria are encased in a peptidoglycan cell wall, an essential polysaccharide structure that protects the cell from osmotic rupture and reinforces cell shape. The integrity of this protective barrier must be maintained across the diversity of environmental conditions wherein bacteria replicate. However, at the cell surface, the cell wall and its synthesis machinery face unique challenges that threaten their integrity. Directly exposed to the extracellular environment, the peptidoglycan synthesis machinery encounters dynamic and extreme physicochemical conditions, which may impair enzymatic activity and critical protein-protein interactions. Biotic and abiotic stressors—including host defenses, cell wall active antibiotics, and predatory bacteria and phage—also jeopardize peptidoglycan integrity by introducing lesions, which must be rapidly repaired to prevent cell lysis. Here, we review recently discovered mechanisms that promote robust peptidoglycan synthesis during environmental and acute stress and highlight the opportunities and challenges for the development of cell wall active therapeutics.
Rich Repertoire of Quorum Sensing Protein Coding Sequences in CPR and DPANN Associated with Interspecies and Interkingdom Communication
Authors: Bernard Charles , Lannes Romain , Li Yanyan , Bapteste Éric , Lopez Philippe
Published: October 2020

The selection of predicted genes for interspecies communication within the CPR and DPANN genomes sheds some light onto the underlying mechanisms supporting their inferred symbiotic lifestyle. Also, considering the lack of core pathways such as the
de novo
synthesis of nucleotides or amino acids in the CPR and DPANN lineages, the persistence of these genes highlights how determinant social traits can be for the survival of some microorganisms. Finally, the considerable number of variants of QS proteins identified among the 69 CPR and DPANN phyla substantially expands our knowledge of prokaryotic communication across the tree of life and suggests that the multiplicity of “dialects” in the microbial world is probably larger than previously appreciated.
Trends in match injury risk in professional male rugby union: a 16-season review of 10 851 match injuries in the English Premiership (2002–2019): the Professional Rugby Injury Surveillance Project
Authors: West Stephen W , Starling Lindsay , Kemp Simon , Williams Sean , Cross Matthew , Taylor Aileen , Brooks John H M , Stokes Keith A
Published: October 2020

Objectives

The Professional Rugby Injury Surveillance Project is the largest and longest running rugby union injury surveillance project globally and focuses on the highest level of rugby in England.

Methods

We examined match injuries in professional men’s rugby over the period 2002/2003 to 2018/2019 and described trends in injuries over this time.

Results

Over the period 2002/2003–2018/2019, 10 851 injuries occurred in 1 24 952 hours of match play, equating to a mean of 57 injuries per club per season and one injury per team per match. The mean incidence, severity (days absence) and burden (days absence/1000 hours) of injury were 87/1000 hours (95% CI 82 to 92), 25 days (95% CI 22 to 28) and 2178 days/1000 hours (95% CI 1872 to 2484), respectively. The tackle accounted for 43% injuries with running the second most common activity during injury (12%). The most common injury location was the head/face with an incidence of 11.3/1000 hours, while the location with the highest overall burden was the knee (11.1 days/1000 hours). Long-term trends demonstrated stable injury incidence and proportion of injured players, but an increase in the mean and median severity of injuries. Concussion incidence, severity and burden increased from the 2009/2010 season onwards and from 2011 to 2019 concussion was the most common injury.

Conclusion

The rise in overall injury severity and concussion incidence are the most significant findings from this work and demonstrate the need for continued efforts to reduce concussion risk as well as a greater understanding of changes in injury severity over time.
Impact of National Drug Pricing Policy 2018 on access to medicines in Lahore division, Pakistan: a pre-post survey study using WHO/HAI methodology
Authors: Saeed Amna , Saeed Hamid , Saleem Zikria , Yang Caijun , Jiang Minghuan , Zhao Mingyue , Ji Wenjing , Aziz Muhammad Majid , Khan Faiz Ullah , Gillani Ali Hassan , Atif Naveel , Fang Yu , Babar Zaheer Ud Din
Published: October 2020

Objective

To evaluate the impact of new National Drug Pricing Policy (NDPP) 2018 on access to medicines in terms of prices, availability and affordability.

Design

Two cross-sectional surveys were undertaken before and after the launch of NDPP 2018, using a modified WHO/Health Action International (WHO/HAI) methodology.

Setting

Four districts of Lahore division, Pakistan.

Participants

16 public sector hospitals and 16 private sector retail pharmacies.

Measures

The pre and post survey data on prices and availability of lowest price generics (LPGs) and originator brands (OBs) of 50 medicines were obtained by visiting the same public and private sector health facilities (n=32). Out of 50, 46 surveyed medicines were from the National Essential Medicines List. Inflation-adjusted median unit prices (MUPs) and median price ratios (MPRs) from 2019 were used for price comparison. Affordability was calculated in terms of number of days’ wages required to get a standard treatment by the lowest paid unskilled government worker.

Results

The overall mean percent availabilities remained poor in both years, that is, far less than 80%. In the public sector, the mean percent availability of OBs improved from 6.8% to 33.1%, whereas, in the case of LPGs, it was reduced from 35.1% to 9%. In the private sector, the mean percent availability of both OBs and LPGs demonstrated slight improvements in 2019, that is, 55.0%–58.3% and 20.3%–32.3%. The adjusted MUPs and MPRs of OBs significantly increased by a median of 4.29% (Wilcoxon test p=0.001, p=0.0001), whereas the adjusted MUPs and MPRs of LPGs increased by a median of 15.7% (p=0.002, p=0.0002). Overall, the affordability of many medicines for common ailments was reduced significantly in 2019.

Conclusions

The availability of medicines slightly improved, except in the case of LPGs, which was reduced in the public sector. The implementation of NDPP 2018 led to increase in drug prices, making the standard treatment for some of the most prevalent ailments unaffordable. So verily, the drug pricing policy must be reviewed to ensure access to essential medicines.
Single assessment of delirium severity during postacute intensive care of chronically critically ill patients and its associated factors: post hoc analysis of a prospective cohort study in Germany
Authors: Wintermann Gloria-Beatrice , Weidner Kerstin , Strauss Bernhard , Rosendahl Jenny
Published: October 2020

Objectives

To assess the delirium severity (DS), its risk factors and association with adverse patient outcomes in chronically critically ill (CCI) patients.

Design

A prospective cohort study.

Setting

A tertiary care hospital with postacute intensive care units (ICUs) in Germany.

Participants

N=267 CCI patients with critical illness polyneuropathy and/or critical illness myopathy, aged 18–75 years, who had undergone elective tracheotomy for weaning failure.

Interventions

None.

Measures

Primary outcomes: DS was assessed using the Confusion Assessment Method for the Intensive Care Unit-7 delirium severity score, within 4 weeks (t1) after the transfer to a tertiary care hospital. In post hoc analyses, univariate linear regressions were employed, examining the relationship of DS with clinical, sociodemographic and psychological variables.Secondary outcomes: additionally, correlations of DS with fatigue (using the Multidimensional Fatigue Inventory-20), quality of life (using the Euro-Quality of Life) and institutionalisation/mortality at 3 (t2) and 6 (t3) months follow-up were computed.

Results

Of the N=267 patients analysed, 9.4% showed severe or most severe delirium symptoms. 4.1% had a full-syndromal delirium. DS was significantly associated with the severity of illness (p=0.016, 95% CI −0.1 to −0.3), number of medical comorbidities (p<0.001, 95% CI .1 to .3) and sepsis (p<0.001, 95% CI .3 to 1.0). Patients with a higher DS at postacute ICU (t1), showed a higher mental fatigue at t2 (p=0.008, 95% CI .13 to .37) and an increased risk for institutionalisation/mortality (p=0.043, 95% CI 1.1 to 28.9/p=0.015, 95% CI 1.5 to 43.2).

Conclusions

Illness severity is positively associated with DS during postacute care in CCI patients. An adequate management of delirium is essential in order to mitigate functional and cognitive long-term sequelae following ICU.

Trial registration number

DRKS00003386.
Effectiveness and cost-effectiveness of a progressive, individualised walking and education programme for prevention of low back pain recurrence in adults: study protocol for the WalkBack randomised controlled trial
Authors: Pocovi Natasha Celeste , Lin Chung-Wei C , Latimer Jane , Merom Dafna , Tiedemann Anne , Maher Christopher , van Tulder Maurits W , Macaskill Petra , Clavisi Ornella , Tong Shuk Yin Kate , Hancock Mark J
Published: October 2020

Introduction

Low back pain (LBP) is recognised globally as a prevalent, costly and disabling condition. Recurrences are common and contribute to much of the burden of LBP. Current evidence favours exercise and education for prevention of LBP recurrence, but an optimal intervention has not yet been established. Walking is a simple, widely accessible, low-cost intervention that has yet to be evaluated. This randomised controlled trial (RCT) aims to establish the effectiveness and cost-effectiveness of a progressive and individualised walking and education programme (intervention) for the prevention of LBP recurrences in adults compared with no treatment (control).

Methods and analysis

A pragmatic, two-armed RCT comparing walking and education (n=349) with a no treatment control group (n=349). Inclusion criteria are adults recovered from an episode of non-specific LBP within the last 6 months. Those allocated to the intervention group will receive six sessions (three face to face and three telephone delivered) with a trained physiotherapist to facilitate a progressive walking programme and education over a 6-month period. The primary outcome will be days to first recurrence of an episode of activity-limiting LBP. The secondary outcomes include days to recurrence of an episode of LBP, days to recurrence of an episode of LBP leading to care seeking, disability and quality of life measured at 3, 6, 9 and 12 months and costs associated with LBP recurrence. All participants will be followed up monthly for a minimum of 12 months. The primary intention-to-treat analysis will assess difference in survival curves (days to recurrence) using the log-rank statistic. The cost-effectiveness analysis will be conducted from the societal perspective.

Ethics and dissemination

Approved by Macquarie University Human Research Ethics Committee (Reference: 5201949218164, May 2019). Findings will be disseminated through publication in peer-reviewed journals and conference presentations.

Trial registration number

ACTRN12619001134112.
Skin and wound care for individuals with graft versus host disease: a scoping review protocol
Authors: Campbell Jill , Gavin Nicole , Button Elise , Roberts Natasha
Published: October 2020

Introduction

Graft versus host disease (GVHD) is a major cause of morbidity and mortality following allogenic haematopoietic stem cell transplantation. It is an immunological reaction, involving many organs, leading to a wide range of clinical manifestations. Cutaneous manifestations are the most common sign of GVHD, as well as pain, vulnerability to infection and impaired quality of life.

Despite the burdens that cutaneous GVHD presents for patients, their carers and the healthcare system, limited evidence is available to guide day to day supportive skin care and wound management. Our objective is to conduct a scoping review to map the evidence for skin and wound management and identify evidence-practice gaps for individuals with acute or chronic cutaneous GVHD.

Methods and analysis

Our review will follow the scoping review methodological framework developed by Arksey and O’Malley and further refined by the Joanna Briggs Institute Scoping Review Methods Manual. Databases to be searched include; PubMed, EMBASE, PsycINFO, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Web of Science and MEDLINE from 1970 to February 2020. Database searches will be supplemented with searches from relevant reference lists and grey literature. Descriptive statistical analyses will be performed.

Ethics and dissemination

This scoping review does not require ethical approval. Findings will be disseminated through a peer-reviewed publication and conference presentation.
Safety and efficacy of larval therapy on treating leg ulcers: a protocol for systematic review and meta-analysis
Authors: Fan Weijing , Yang Baozhong , Hu Xiaoming , Yang Xiao , Shi Chenyan , Liu Guobin
Published: October 2020

Introduction

Leg ulcers (LUs) not only seriously affect life and work of patients, but also bring huge economic burden to the society. As a potential underused biological debridement, larval therapy provides help for the treatment of LUs. The purpose of our research is to assess whether patients with LUs can benefit from larval therapy.

Methods and analysis

The following electronic databases will be searched: PubMed, EMBASE, Web of Science, the Cochrane Library, China National Knowledge Infrastructure Database, Wanfang Database and Chinese Biological Medicine. Randomised controlled trials are eligible for inclusion. There will be no restrictions with respect to language and search date is up to June 2020. Primary outcomes investigated are complete healing rate after treatment, time to ulcer healing, reduction of wound surface area and adverse events. Risk ratios will be used for categorical data; weighted mean difference will be used for measurement data. Subgroup analysis and sensitivity analysis will be considered if heterogeneity exists. The results of data synthesis will be performed by narrative summary and quantitative analysis.

Ethics and dissemination

This systematic review does not require the approval of the ethics committee because individual data on patients are not collected. The results of the study will be disseminated in peer-reviewed journals.

PROSPERO registration number

CRD42020176953.
Mortality and pulmonary complications in patients undergoing upper extremity surgery at the peak of the SARS-CoV-2 pandemic in the UK: a national cohort study
Authors: Dean Benjamin John Floyd
Published: October 2020

Introduction

This study reports the 30-day mortality, SARS-CoV-2 complication rate and SARS-CoV-2-related hospital processes at the peak of the first wave of the pandemic in the UK.

Methods

This national, multicentre, cohort study at 74 centres in the UK included all patients undergoing any surgery below the elbow at the peak of the UK pandemic. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The secondary outcomes were SARS-CoV-2 complication rates and overall complication rates. A clinician survey relating to SARS-CoV-2 safety processes was carried out for each participating centre.

Results

This analysis includes 1093 patients who underwent upper limb surgery from the 1 to 14 April 2020 inclusively. The overall 30-day mortality was 0.09% (1 pre-existing SARS-CoV-2 pneumonia) and the mortality of day case surgery was zero. Most centres (96%) screened patients for symptoms prior to admission, only 22% routinely tested for SARS-CoV-2 prior to admission. The SARS-CoV-2 complication rate was 0.18% (2 pneumonias) and the overall complication rate was 6.6% (72 patients). Both SARS-CoV-2-related complications occurred in patients who had been hospitalised for a prolonged period before their surgery and a total of 19 patients (1.7%) were SARS-CoV-2 positive.

Conclusions

The SARS-CoV-2-related complication rate for upper limb surgery even at the peak of the UK pandemic was low at 0.18% and the mortality was zero for patients admitted on the day of surgery. Urgent surgery should not be delayed pending the results of SARS-CoV-2 testing. Routine SARS-CoV-2 testing for day case upper limb surgery not requiring general anaesthesia may be excessive and have unintended negative impacts.
CASPA (CArdiac Sarcoidosis in PApworth) improving the diagnosis of cardiac involvement in patients with pulmonary sarcoidosis: protocol for a prospective observational cohort study
Authors: Quijano-Campos Juan Carlos , Williams Lynne , Agarwal Sharad , Tweed Katharine , Parker Robert , Lalvani Ajit , Chiu Yi-Da , Dorey Kane , Devine Thomas , Stoneman Victoria , Toshner Mark , Thillai Muhunthan
Published: October 2020

Introduction

Sarcoidosis is a multisystem disease, predominantly affecting the lungs but can involve the heart, resulting in cardiac sarcoidosis (CS). Patients require MRI/Positron Emission Tomography (PET) scans for diagnosis. Echocardiography, ECG and Holter monitoring may be indicative but not diagnostic alone. Patients can present late with conduction defects, heart failure or sudden death. The CASPA (CArdiac Sarcoidosis in PApworth) study protocol aims to (1) use MRI to identify CS prevalence; (2) use speckle-tracking echocardiography, signal averaged ECG and Holter monitoring to look for diagnostic pathways; and (3) identify serum proteins which may be associated with CS.

Methods and analysis

Participants with pulmonary sarcoidosis (and no known cardiac disease) from Royal Papworth Hospital will have the following: cardiac MRI with late gadolinium, two-dimensional transthoracic echocardiography with speckle tracking, signal averaged ECG and 24-hour Holter monitor. They will provide a serum sample for brain natriuretic peptide levels and proteomics by liquid chromatography coupled to high-resolution mass spectrometry. All data will be collected on OpenClinica platform and analysed approximately 6 months after final patient recruitment.

Ethics and dissemination

The Camden & Kings Cross Research Ethics Committee approved the protocol (REC number: 17/LO/0667). Integrated Research Approval System (IRAS) 222 720. Dissemination of findings will be via conference presentations and submitted to peer-reviewed journals.
Cluster cross-over randomised trial of paediatric airway management devices in the simulation lab and operating room among paramedic students
Authors: Hansen Matthew Lee , Wagner Adam , Schnapp Ashley , Lin Amber , Le Nancy , Deverman Sarah , Pedigo Elizabeth , Johnson Andrea , Cusick Jordan , Gries Heike , Kato Meredith
Published: October 2020

Objectives

The objective of this study was to compare paediatric emergency airway management strategies in the simulation lab and operating room environments.

Methods

This was a two-part cluster cross-over randomised trial including simulation lab and operating room environments conducted between January 2017 and June 2018 in Portland, Oregon, USA. In simulated infant cardiac arrests, paramedic students placed an endotracheal tube, an i-gel or a laryngeal mask airway in random order. In the operating room, paramedic students placed a laryngeal mask airway or i-gel device in random order in sequential patients. The primary outcome for both portions of the study was time to ventilation. In the operating room portion, we also evaluated leak pressures and average initial tidal volumes.

Results

There were 58 paramedic students who participated in the simulation lab and 22 who participated in the operating room study. The mean time to airway placement in the simulation lab was 48.5 s for the i-gel, 68.9 s for the laryngeal mask and 129.5 s for the endotracheal tube. In the operating room, mean time to i-gel placement was 34.3 s with 45.2 s for the laryngeal mask. In multivariable analysis of the simulation study, the laryngeal mask and i-gel were significantly faster than the endotracheal tube, and the i-gel was faster than the laryngeal mask. In the operating room, there was no significant difference in time to placement, leak pressure and average volume of the first five breaths between the i-gel and laryngeal mask.

Conclusions

We found that paramedic students were able to place supraglottic devices rapidly with high success rates in simulation lab and operating room environments. Supraglottic devices, particularly the i-gel, were rated as easy to use. The i-gel may be easiest to use since it lacks an inflable cuff and requires fewer steps to place.
Prevalence of mismatch repair deficiency and Lynch syndrome in a cohort of unselected small bowel adenocarcinomas
Authors: Suerink Manon , Kilinç Gül , Terlouw Diantha , Hristova Hristina , Sensuk Lily , van Egmond Demi , Farina Sarasqueta Arantza , Langers Alexandra M J , van Wezel Tom , Morreau Hans , Nielsen Maartje
Published: October 2020

Aims

Previous estimates of the prevalence of mismatch repair (MMR) deficiency and Lynch syndrome in small bowel cancer have varied widely. The aim of this study was to establish the prevalence of MMR deficiency and Lynch syndrome in a large group of small bowel adenocarcinomas.

Methods

To this end, a total of 400 small bowel adenocarcinomas (332 resections, 68 biopsies) were collected through the Dutch nationwide registry of histopathology and cytopathology (Pathologisch-Anatomisch Landelijk Geautomatiseerd Archief (PALGA)). No preselection criteria, such as family history, were applied, thus avoiding (ascertainment) bias. MMR deficiency status was determined by immunohistochemical staining of MMR proteins, supplemented byMLH1promoter hypermethylation analysis and next generation sequencing of the MMR genes.

Results

MMR deficiency was observed in 22.3% of resected and 4.4% of biopsied small bowel carcinomas. Prevalence of Lynch syndrome was 6.2% in resections and 0.0% in biopsy samples. Patients with Lynch syndrome-associated small bowel cancer were significantly younger at the time of diagnosis than patients with MMR-proficient and sporadic MMR-deficient cancers (mean age of 54.6 years vs 66.6 years and 68.8 years, respectively, p<0.000).

Conclusions

The prevalence of MMR deficiency and Lynch syndrome in resected small bowel adenocarcinomas is at least comparable to prevalence in colorectal cancers, a finding relevant both for treatment (immunotherapy) and family management. We recommend that all small bowel adenocarcinomas should be screened for MMR deficiency.
Serum IgG anti-GD1a antibody and mEGOS predict outcome in Guillain-Barré syndrome
Authors: Yamagishi Yuko , Kuwahara Motoi , Suzuki Hidekazu , Sonoo Masahiro , Kuwabara Satoshi , Yokota Takanori , Nomura Kyoichi , Chiba Atsuro , Kaji Ryuji , Kanda Takashi , Kaida Ken-ichi , Mutoh Tatsuro , Yamasaki Ryo , Takashima Hiroshi , Matsui Makoto , Nishiyama Kazutoshi , Sobue Gen , Kusunoki Susumu
Published: October 2020

Objective

Approximately 15%–20% of patients with Guillain-Barré syndrome (GBS) are unable to walk independently at 6 months from the onset of neurological symptom. The modified Erasmus GBS outcome score (mEGOS) has been reported as a prognostic tool.

Herein we investigated the association between a poor outcome, inability to walk independently at 6 months and presence of antiganglioside antibodies.

Methods

The clinical and serological data of 177 patients with GBS were retrospectively collected in Japan to assess the associations between a poor outcome and serum IgG antibodies against each ganglioside (GM1, GD1a, GalNAc-GD1a, GQ1b and GT1a). In addition, we investigated whether the combination of mEGOS and serum IgG antibodies against gangliosides is useful in predicting a poor outcome.

Results

The patients with IgG anti-GD1a antibodies more frequently showed poor outcomes than those without these antibodies (9 (36%) of 25 vs 8 (6%) of 127 patients, p<0.001). Particularly, 80% showed a poor outcome when they had both serum IgG anti-GD1a antibody and a high mEGOS of ≥10 on day 7 of admission.

Conclusions

The combination of serum IgG anti-GD1a antibodies and a high mEGOS could help in making a more accurate prognosis of patients than mEGOS alone, especially for predicting poor outcomes.
Anomalous erosion patterns on the cheek teeth of babirusa (genus Babyrousa)
Authors: Macdonald A.A.
Published: October 2020

Two types of anomalous erosive wear, designated “Wear” and “Groove”, were found in the molar teeth of adult babirusa (genus Babyrousa Perry, 1811) species from Buru or the Sula Islands and Sulawesi, Indonesia. A survey of 590 specimens of babirusa crania and mandibles from international museums and private collections revealed their presence in 20 of 187 specimens from Buru or the Sula Islands, in 99 of 391 specimens from Sulawesi, and in 4 of 31 subfossil specimens from South Sulawesi. “N_Wear” comprised a discrete indentation or almost circular erosion of the enamel and underlying dentine in a molar tooth; “W_Wear” comprised tooth indentations of irregular shape larger than 7 mm × 7 mm in size; “E_Wear” comprised extensive tooth indentation. “Wear” anomalies were found on 10% of specimens from Buru or the Sula Islands and on 17% of all Sulawesi crania and mandibles. It was hypothesised that tooth grinding of the abrasive seeds of the wild banana (Musa balbisiana Colla) initiated this anomaly. Groove was a deep, oval-shaped cleft cut into the enamel and dentine between two molar teeth. Groove anomalies were evident in 3% of Buru or the Sula Islands specimens and in 12% of all Sulawesi specimens. No conclusion was reached regarding the initiator of the Groove anomaly.
Feshbach–Villars equation in a κ-Minkowski spacetime
Authors: Hamil B. , Merad M.
Published: October 2020

In this paper, by using the Dirac derivatives the Klein–Gordon (K-G) equation is determined in a [Formula: see text]-Minkowski spacetime. The dispersion relation and the first-order approximation case are deduced. The Feshbach–Villars (FV) equation is derived by applying the new linearization process to the time. We then study the effect of magnetic interaction on energies spectrum in a [Formula: see text]-Minkowski spacetime as an application, as a result we found that the energies spectrum are not symmetrical. We also study the case of hydrogen atom in non-relativistic limit by using perturbation theory. The upper bound of the [Formula: see text]-deformation parameter is evaluate, on the basis of the experimental data for [Formula: see text] transition frequency.
Numerical solutions to Giovannini’s parton branching equation up to TeV energies at the LHC
Authors: Ong Z. , Agarwal P. , Ang H. W. , Chan A. H. , Oh C. H.
Published: October 2020

The full Giovannini parton branching equation is integrated numerically using the fourth-order Runge-Kutta method. Using a simple hadronization model, a charged-hadron multiplicity distribution is obtained. This model is then fitted to various experimental data up to the TeV scale to study how the Giovannini parameters vary with collision energy and type. The model is able to describe hadronic collisions up to the TeV scale and reveals the emergence of gluonic activity as the center-of-mass energy increases. A prediction is made for [Formula: see text].
A modified filter-based model for simulation of unsteady cavitating flows around a NACA66 hydrofoil
Authors: Zhang Shuwei , Chen Hongxun , Ma Zheng
Published: October 2020

Unsteady cavitating turbulent flow around a NACA66 hydrofoil was simulated using a mass transfer cavitation model and a modified filter-based turbulence model in this paper. The modified filter-based turbulence model can accurately predict the pressure coefficient in midplane and shedding frequency of the unsteady cloud cavitation than standard [Formula: see text]–[Formula: see text] model and filter-based turbulence model. The time evolution of transient cavitation cloud structure predicted by the three-turbulence model was compared. The result which was predicted by the modified filter-based turbulence model is in good agreement with the experimental results. The time evolution of re-entrant jet had been analyzed. The instantaneous wall-pressure evolution on the suction surface (SS) predicted by the modified filter-based turbulence model had been analyzed. The cavitation-vortex interaction had been analyzed in this study. The different effects on the cavitation-vortex interaction of the vortex stretching term, vortex dilatation term and baroclinic torque term in the transport equation of vorticity had been discussed.
Who are My Family Members? A Solution Based on Image Processing and Machine Learning
Authors: Kiley Matthew R. , Hossain Md Shafaeat
Published: October 2020

Image creation and retention are growing at an exponential rate. Individuals produce more images today than ever in history and often these images contain family. In this paper, we develop a framework to detect or identify family in a face image dataset. The ability to identify family in a dataset of images could have a critical impact on finding lost and vulnerable children, identifying terror suspects, social media interactions, and other practical applications. We evaluated our framework by performing experiments on two facial image datasets, the Y-Face and KinFaceW, comprising 37 and 920 images, respectively. We tested two feature extraction techniques, namely PCA and HOG, and three machine learning algorithms, namely K-Means, agglomerative hierarchical clustering, and K nearest neighbors. We achieved promising results with a maximum detection rate of 94.59% using K-Means, 89.18% with agglomerative clustering, and 77.42% using K-nearest neighbors.