bluuebunny/crossref_metadata_2025 huggingface dataset:
New Design Concepts for the Tribological Contact of Cylinder Block and Valve Plate
Authors: Geffroy Stefan , Wegner Stephan , Gels Stefan , Murrenhoff Hubertus , Schmitz Katharina
Published: October 2020

Axial piston machines are the most widely used type of hydraulic displacement machines and are characterized by their high reliability and efficiency. However, in order to ensure the high efficiency, the tribological contacts have to be precisely optimized. One of the three essential contacts in axial piston machines is the contact of valve plate and cylinder block, which is the subject of this paper. In a previous research project, a simulation model was built up specifically for the tribological contact of valve plate and cylinder block. A test rig was developed and installed for the validation of the simulation results. Both, the experimental and the simulation results show that the cylinder block tilts to the high-pressure side. It holds this preferred position nearly constantly for the different load situations over one revolution with four or five pistons pressurized with high pressure at the same time. The tilting increases the danger of solid body contact in the area of minimum gap height. In addition, it leads to temperature hot spots. Both effects necessitate the use of coatings as alternatives to the commonly used leaded alloys. This paper presents new design concepts for the optimization of the tribological contact of valve plate and cylinder block. Additional pressure pockets in the valve plate’s high-pressure kidney generate a torque and thus reduce the tilt angle of the cylinder block. By implementing additional pressure pockets at the cylinder block an imbalance results, which prevents a constant preferred position. Both concepts have the aim to reduce the heat concentration and improving the overall behavior of the tribological contact. The development and comparison of these concepts are based on a numerical analysis.
Study on an Underwater Flexible Manipulator Based on Hydraulic Drive
Authors: Li Xin , Xu He , Yang Chen , Wang Haihang , Yu Fengshu
Published: October 2020

The underwater flexible robot is a field of continuous exploration and innovation. An underwater flexible manipulator with the functions of bending and grasping is presented in this paper, which is driven by the water hydraulic. The flexible manipulator is consisted mainly of three sets of transverse and three sets of longitudinal Mckibben artificial muscles (MAM) equidistantly arranged. The motions of the manipulator were driven by accurately controlling the length of each MAM that was changed by controlling the internal pressure, which was provided by the hydraulic power subsystem. The flexible manipulator was controlled remotely by the control subsystem. The inverse kinematics of the flexible manipulator was studied based on the neural network in this paper. The feasibility of the neural network inverse kinematics was proved by the data analysis. The three-dimensional virtual model of the flexible manipulator was projected into the captured real scene by the augmented reality (AR) technology to judge the bending degree of the manipulator operation, which could be seen in the experiment image.
Methodology for the Evaluation of Gear Pump Performance
Authors: Williams Logan T.
Published: October 2020

Currently, most performance curves of gear pumps present volumetric efficiency as a function of one or more operating conditions. However, the nature of gear pumps is that volumetric efficiency is dependent on pump speed, pump pressure rise, and fluid viscosity. This dependency on multiple parameters impedes direct comparisons between pumps tested at disparate operating conditions or on different testbeds. A new method has been developed that formulates the volumetric efficiency as a function of a single parameter that captures pump speed, pressure, and fluid viscosity. The characteristics of the pump is then captured by curve fitting two constants to empirical data. This method allows extrapolation of pump performance beyond empirical data and direct comparison of the volumetric efficiency curves of two pumps tested under disparate conditions within a single plot. This work describes the analytical derivation of the methodology and the empirical data used for validations. Additionally, several possible applications of this method are presented.
Impact of Dynamics on the Losses at Radial Ball Piston Pump Interfaces
Authors: Bohach Garrett , Nahin Md Minal , Severson Eric , Van de Ven James D.
Published: October 2020

This paper presents a mathematical model of a radial ball piston pump/motor. The specific application of the pump is for direct integration with a high speed electric motor for use in off highway vehicles. The pump/motor must operate across all four quadrants with high flow rates at a low pressure differential. The model captures the major mechanical and volumetric losses within the hydraulic machine with specific attention given to the ball-cylinder interface and the pintle-rotor interface. The leakage and shear at the ball piston interface are dependent on the position of the ball piston in the cylinder; therefore, the dynamics of the ball piston are calculated. The pintle-rotor model includes the port geometry, which influences the flow rates into and out of the pump/motor. Leakage and shear at the interface are dependent on the gap height between the two surfaces; consequently, the model calculates the radial forces acting on the rotor and uses journal bearing theory to predict the eccentricity. This eccentricity balances the other forces and is necessary to determine the interface losses. Lastly, the importance of these dynamics is evaluated to determine which are needed in a future optimization framework. It is shown that considering the dynamics of both interfaces captures significantly more losses and results in a more accurate model than an earlier simplified one.
Development of a Physical Analog Excavator for Studies in Interactions Between Hydraulic Equipment and Human Operators
Authors: Wiens Travis , Klarkowski Madison , Zahabi Nima
Published: October 2020

This paper presents a scale model excavator intended to allow for studies on human-machine interactions. In the past, this work has been performed on full-scale equipment which can be dangerous and costly to acquire and operate, or fully in simulation, which requires high precision models of complex effects such as soil forces (e.g. using the Discrete Element Method, DEM, simulating thousands of particles). Also simulation models with scenes projected on computer monitors or in virtual reality may not be realistic enough for the human operator to be fully immersed and behave in a realistic manner. The motion of the small-scale excavator presented here is directed by a digital model of a hydraulic machine given inputs of operator commands and actuator forces, allowing it to mimic the behavior of various hydraulic architectures (e.g. pressure compensated load sensing vs open center vs closed center systems). The excavator is used to dig in physical soils, generating realistic soil-tool interaction forces (which are fed back into the digital machine model) without the need for computationally expensive DEM models. This allows for rapid, low-cost evaluation of various hardware modifications as well as human-machine interaction effects. We also present some preliminary data from a pilot study investigating energy efficiency.
On/Off Valves Synchronization and Reliability Evaluation of a Digital Hydraulic Actuator
Authors: Mantovani Ivan J. , Kagueiama Heitor A. , Gama Artur T. de C. , Dell' Amico Alessandro , Krus Petter , De Negri Victor J.
Published: October 2020

The development of actuators for flight control surfaces based on electrical technologies had a breakthrough in the last decade. Nevertheless, servo-hydraulic systems are still widely used. Servo Hydraulic Actuators (SHA) have the advantages of precise positioning, high dynamic response and being a jam-free solution in case of failures, but they present low energy efficiency. Digital hydraulics has become a topic of interest in improving energy efficiency in the fluid power community. A Digital Hydraulic Actuator (DHA) for aircraft is being developed to be used in primary flight control surfaces. The DHA concept is based on secondary control with multi-chamber cylinders and shows an energy efficiency gain with a similar response when compared to SHA. However, the opening and closing times of on/off valves are different and uncertain. These aspects may result in short circuits, bringing energy losses, or in blocked chambers, which may cause pressure peaks or cavitation. Consequently, the DHA system may have a lower energy efficiency or presents vibration due to fluid blocking. The present paper presents a solution for these issues and the reliability evaluation of the DHA. The opening and closing times issues are addressed using the synchronization between on/off valves through a method to find the correct time for valve opening control. As a result, the synchronization of pressure shifting without knowledge of the response times of on/off valves was accomplished. Moreover, when used periodically, this method can estimate future failures in valves due to a change of the required time delay. In order to evaluate the system reliability, FTA models were developed considering valve and pressure line failures, modelling how the failures affect force availability to move the control surfaces. The resulting FTAs were reduced to the minimum cut-sets that lead to force profiles that are insufficient for a safe flight and also may lead to an aircraft crash. Considering that the on/off valves have similar failure rates to those of servo valves, the results show that DHA and SHA have comparable reliability levels.
Valve Timing and Area Profile Selection for Hydraulic Pumps and Motors
Authors: Boyce-Erickson Grey C. , Chase Thomas R. , Van de Ven James D.
Published: October 2020

A significant amount of research has been conducted to select valve timing and area profiles that create efficient and quiet hydraulic pumps and motors. Numerous active valve architectures have been modeled and optimized, but the rationale for the final solution is often unclear. The solution is usually highly dependent on the modeled valve geometry constraints and the duty cycle of the pump or motor for which the valve was optimized. In contrast, this paper proposes a methodology for designing efficient valving that is not constrained to any specific valve geometry, operating point, parameterization, or physical system limitation. An idealized valve area profile is formulated using a piston-cylinder model with variable valve openings. A working fluid that has a pressure dependent bulk modulus is utilized in the model. The valve timing is idealized by constraining it to produce a specified constant pressure drop across the valve. The idealized area profile is synthesized by modeling the piston-cylinder as a pump with passive (check) valves. A representation of the idealized timing is demonstrated for positive pressure differential and positive rotation direction, also known as the first quadrant. The effect of varying pressure on valve timing is shown for the first quadrant, but the trend can be extrapolated for all quadrants of operation. The idealized valve area profile is implemented as fixed valve timing in a pump-motor, meaning the valve area is only a function of the timing angle of the rotating group. Fixed valve timing is preferred to variable valve timing as it can often be implemented mechanically, increasing reliability. The pump-motor is simulated in one rotation direction through a pressure range. Performance is high in pumping operation, but when the pressure differential is reversed, cylinder pressure spikes ensue. Two strategies to modify an idealized valve area profile are presented: timing grooves and a pressure shifted valve timing. Timing grooves reduce pressure spikes and cavitation in the cylinder but generally increase throttling losses. A pressure shifted valve timing has lower throttling energy losses, making it the favored solution.
A Design Procedure for Multistage External Gear Pumps
Authors: Guerra Davide , Polastri Marco , Battarra Mattia , Suman Alessio , Mucchi Emiliano , Pinelli Michele
Published: October 2020

In this work, the authors present a robust and integrated procedure for the design of multi-stage gear pumps to be used in dry sump system applications. Based on the target delivery flow rate, rotational speed and fluid properties, the developed iterative method enables to directly obtain the geometrical features and the working parameters of the pump components, such as gearpair specifics, shaft and journal bearing dimensions, clearance values. The methodology is then applied to a case study in order to highlight its features and detail the achievable outcomes. Quality of the results is assessed by means of a CFD analysis, demonstrating the capability to obtain the expected volumetric efficiency.
Fast Calculation of Stiff Hydraulic Models Using the Modified Pseudo-Dynamic Solver
Authors: Malysheva Julia , Handroos Heikki
Published: October 2020

The work addresses the problem of the fast and accurate calculation of the mathematically stiff hydraulic models using the modified pseudo-dynamic solver (PDS). In particular, it studies which of the numerical integration methods inside the modified PDS ensure efficient calculation of the stiff hydraulic model. In the work, the operating principle of the modified PDS is described. The effect of the three different fixed-step integration methods (Euler, Runge-Kutta of fourth order, and modified Heun’s method) are considered. The numerical stability of the modified Heun’s method is improved by substituting the purely turbulent orifice model with the two-regime orifice model. The two-regime orifice accounts for both the turbulent and laminar flows and thus allows to avoid the numerical problems related to the small pressure drops. As a numerical example of the mathematically stiff hydraulic model a hydraulic circuit with the two-way flow control valve which contains small volume is employed. As the implementation environment for the developed simulation models the compiled C language that supports the real-time simulation is chosen. The solutions obtained for the numerical example using the modified PDS based on the three integration methods, their accuracies and calculation speeds are presented in comparison with the solution obtained using conventional integration procedure. The obtained results show that, in general, the modified PDS allows to solve numerically stiff hydraulic models in a very efficient way ensuring accelerated simulation with the high solution accuracy. It is also shown that the simulation speed-up can be obtained not only by the complexity reduction of the numerical integration method employed inside the modified PDS but also by increasing its numerical stability.
Collecting data with a mobile phone: Studies of mechanical laws such as energy and momentum conservation
Authors: Hart Maximillian , Kuzyk Mark G.
Published: October 2020

We use videos taken with a mobile phone to study conservation of energy, conservation of momentum, and the work-energy theorem by analyzing the collision of a cue ball and the eight ball. A video of the full time sequence, starting from before the cue ball is struck until well after the collision, is recorded with a mobile phone. The video is imported into Origin (free to teachers and students taking a class) [OriginLab Corporation, Origin, Version 2020 (OriginLab Corporation, Northampton, MA, USA, 2020)], where the coordinates of the balls are digitized frame-by-frame using the free Video Extractor app. From these data, the velocities are determined as a function of time and used to determine the energy and momentum of each ball. The data suggest that the balls slip through part of their motion when rotating at an angular velocity different than the rolling angular velocity, so angular momentum and frictional torque must be considered. Such experiments require no specialized equipment other than a device to take a video, and the act of digitizing the data provides the student with visual reinforcement of the physics. Experimentation by students outside of campus can be fun for them and provides a useful alternative to classes when in-lab experiments are not practical. Use of a mobile phone in this way is generally applicable to any other mechanical phenomena that involve motion.
Evaluation of capacitive micromachined ultrasonic transducers for passive monitoring of microbubble-assisted ultrasound therapies
Authors: Dauba Ambre , Goulas Jordane , Colin Laurent , Jourdain Laurène , Larrat Benoit , Gennisson Jean-Luc , Certon Dominique , Novell Anthony
Published: October 2020

Passive cavitation detection can be performed to monitor microbubble activity during brain therapy. Microbubbles under ultrasound exposure generate a response characterized by multiple nonlinear emissions. Here, the wide bandwidth of capacitive micromachined ultrasonic transducers (CMUTs) was exploited to monitor the microbubble signature through a rat skull and a macaque skull. The intrinsic nonlinearity of the CMUTs was characterized in receive mode. Indeed, undesirable nonlinear components generated by the CMUTs must be minimized as they can mask the microbubble harmonic response. The microbubble signature at harmonic and ultra-harmonic components (0.5–6 MHz) was successfully extracted through a rat skull using moderate bias voltage.
HSB-1/HSF-1 pathway modulates histone H4 in mitochondria to control mtDNA transcription and longevity
Authors: Sural Surojit , Liang Chung-Yi , Wang Feng-Yung , Ching Tsui-Ting , Hsu Ao-Lin
Published: October 2020

HSB-1/HSF-1 modulates longevity and mitochondrial function by mediating histone H4-dependent regulation of mtDNA gene expression.
A quasi-paired cohort strategy reveals the impaired detoxifying function of microbes in the gut of autistic children
Authors: Zhang Mengxiang , Chu Yanan , Meng Qingren , Ding Rui , Shi Xing , Wang Zuqun , He Yi , Zhang Juan , Liu Jing , Zhang Jie , Yu Jun , Kang Yu , Wang Juan
Published: October 2020

Impairment in gut microbial detoxification is correlated with mitochondrial dysfunction and disease severity in autistic children.
Dynamic brain-to-brain concordance and behavioral mirroring as a mechanism of the patient-clinician interaction
Authors: Ellingsen Dan-Mikael , Isenburg Kylie , Jung Changjin , Lee Jeungchan , Gerber Jessica , Mawla Ishtiaq , Sclocco Roberta , Jensen Karin B. , Edwards Robert R. , Kelley John M. , Kirsch Irving , Kaptchuk Ted J. , Napadow Vitaly
Published: October 2020

Brain activity concordance between patients and clinicians supports therapeutic alliance and treatment relief of pain.
Decellularized extracellular matrix scaffolds identify full-length collagen VI as a driver of breast cancer cell invasion in obesity and metastasis
Authors: Wishart Andrew L. , Conner Sydney J. , Guarin Justinne R. , Fatherree Jackson P. , Peng Yifan , McGinn Rachel A. , Crews Rebecca , Naber Stephen P. , Hunter Martin , Greenberg Andrew S. , Oudin Madeleine J.
Published: October 2020

Collagen VI, an ECM protein up-regulated in triple-negative breast cancer and obese individuals, drives breast cancer metastasis.
A continuous pathway for fresh water along the East Greenland shelf
Authors: Foukal Nicholas P. , Gelderloos Renske , Pickart Robert S.
Published: October 2020

The East Greenland Coastal Current connects fresh water from the arctic to the subpolar North Atlantic.
Slowing down of dynamics and orientational order preceding crystallization in hard-sphere systems
Authors: Lehmkühler Felix , Hankiewicz Birgit , Schroer Martin A. , Müller Leonard , Ruta Beatrice , Sheyfer Dina , Sprung Michael , Tono Kensuke , Katayama Tetsuo , Yabashi Makina , Ishikawa Tetsuya , Gutt Christian , Grübel Gerhard
Published: October 2020

Dynamics in dense hard-sphere systems close to crystallization and vitrification is governed by their orientational order.
Increased ecological resource variability during a critical transition in hominin evolution
Authors: Potts Richard , Dommain René , Moerman Jessica W. , Behrensmeyer Anna K. , Deino Alan L. , Riedl Simon , Beverly Emily J. , Brown Erik T. , Deocampo Daniel , Kinyanjui Rahab , Lupien Rachel , Owen R. Bernhart , Rabideaux Nathan , Russell James M. , Stockhecke Mona , deMenocal Peter , Faith J. Tyler , Garcin Yannick , Noren Anders , Scott Jennifer J. , Western David , Bright Jordon , Clark Jennifer B. , Cohen Andrew S. , Keller C. Brehnin , King John , Levin Naomi E. , Brady Shannon Kristina , Muiruri Veronica , Renaut Robin W. , Rucina Stephen M. , Uno Kevin
Published: October 2020

Adaptations characteristic of early
Homo sapiens
prevailed during a shift to unstable environment and less predictable resources.
Mucosal immunity and the eradication of polio
Authors: Donlan Alexandra N. , Petri William A.
Published: October 2020

Completing global polio eradication will require a new oral vaccine
Learning quadrupedal locomotion over challenging terrain
Authors: Lee Joonho , Hwangbo Jemin , Wellhausen Lorenz , Koltun Vladlen , Hutter Marco
Published: October 2020

A learning-based locomotion controller enables a quadrupedal ANYmal robot to traverse challenging natural environments.
Metagenomes of Maize Rhizosphere Samples after Different Fertilization Treatments at Molelwane Farm, Located in North-West Province, South Africa
Authors: Babalola Olubukola Oluranti , Enebe Matthew Chekwube
Published: October 2020

The need for sustainable agriculture is a global issue that requires urgent attention, particularly in the areas of soil fertility enhancement and management. In this study, the effects of organic and inorganic fertilizers on the rhizosphere microbial communities of maize plants were evaluated.
Additive effects of green tea and coffee on all-cause mortality in patients with type 2 diabetes mellitus: the Fukuoka Diabetes Registry
Authors: Komorita Yuji , Iwase Masanori , Fujii Hiroki , Ohkuma Toshiaki , Ide Hitoshi , Jodai-Kitamura Tamaki , Yoshinari Masahito , Oku Yutaro , Higashi Taiki , Nakamura Udai , Kitazono Takanari
Published: October 2020

Introduction

The impact of consuming green tea or coffee on mortality in patients with diabetes is controversial. We prospectively investigated the impact of each beverage and their combination on mortality among Japanese patients with type 2 diabetes.

Research design and methods

In all, 4923 patients (2790 men, 2133 women) with type 2 diabetes (mean age, 66 years) were followed prospectively (median, 5.3 years; follow-up rate, 99.5%). We evaluated the amount of green tea and coffee consumed using self-administered questionnaires.

Results

During the follow-up period, 309 participants died. The consumption of green tea, coffee, and a combination of the beverages was associated with reduced all-cause mortality. Multivariable-adjusted hazard ratios (95% CIs) for green tea were as follows: none 1.0 (referent); 0.85 (0.60–1.22) for ≤1 cup/day; 0.73 (0.51–1.03) for 2–3 cups/day; 0.60 (0.42–0.85) for ≥4 cups/day; and P for trend, 0.002. For coffee, they were: none 1.0 (referent); 0.88 (0.66–1.18) for <1 cup/day; 0.81 (0.58–1.13) for 1 cup/day; 0.59 (0.42–0.82) for ≥2 cups/day; P for trend, 0.002. With the combination they were 1.0 (referent) for no consumption of green tea and coffee; 0.49 (0.24–0.99) for 2–3 cups/day of green tea with ≥2 cups/day of coffee; 0.42 (0.20–0.88) for ≥4 cups/day of green tea with 1 cup/day of coffee; and 0.37 (0.18–0.77) for ≥4 cups/day of green tea with ≥2 cups/day of coffee.

Conclusions

Higher consumption of green tea and coffee was associated with reduced all-cause mortality: their combined effect appeared to be additive in patients with type 2 diabetes.
Artificial intelligence-enabled screening for diabetic retinopathy: a real-world, multicenter and prospective study
Authors: Zhang Yifei , Shi Juan , Peng Ying , Zhao Zhiyun , Zheng Qidong , Wang Zilong , Liu Kun , Jiao Shengyin , Qiu Kexin , Zhou Ziheng , Yan Li , Zhao Dong , Jiang Hongwei , Dai Yuancheng , Su Benli , Gu Pei , Su Heng , Wan Qin , Peng Yongde , Liu Jianjun , Hu Ling , Ke Tingyu , Chen Lei , Xu Fengmei , Dong Qijuan , Terzopoulos Demetri , Ning Guang , Xu Xun , Ding Xiaowei , Wang Weiqing
Published: October 2020

Introduction

Early screening for diabetic retinopathy (DR) with an efficient and scalable method is highly needed to reduce blindness, due to the growing epidemic of diabetes. The aim of the study was to validate an artificial intelligence-enabled DR screening and to investigate the prevalence of DR in adult patients with diabetes in China.

Research design and methods

The study was prospectively conducted at 155 diabetes centers in China. A non-mydriatic, macula-centered fundus photograph per eye was collected and graded through a deep learning (DL)-based, five-stage DR classification. Images from a randomly selected one-third of participants were used for the DL algorithm validation.

Results

In total, 47 269 patients (mean (SD) age, 54.29 (11.60) years) were enrolled. 15 805 randomly selected participants were reviewed by a panel of specialists for DL algorithm validation. The DR grading algorithms had a 83.3% (95% CI: 81.9% to 84.6%) sensitivity and a 92.5% (95% CI: 92.1% to 92.9%) specificity to detect referable DR. The five-stage DR classification performance (concordance: 83.0%) is comparable to the interobserver variability of specialists (concordance: 84.3%). The estimated prevalence in patients with diabetes detected by DL algorithm for any DR, referable DR and vision-threatening DR were 28.8% (95% CI: 28.4% to 29.3%), 24.4% (95% CI: 24.0% to 24.8%) and 10.8% (95% CI: 10.5% to 11.1%), respectively. The prevalence was higher in female, elderly, longer diabetes duration and higher glycated hemoglobin groups.

Conclusion

This study performed, a nationwide, multicenter, DL-based DR screening and the results indicated the importance and feasibility of DR screening in clinical practice with this system deployed at diabetes centers.

Trial registration number

NCT04240652.
Reusability of filtering facepiece respirators after decontamination through drying and germicidal UV irradiation
Authors: Vernez David , Save Jonathan , Oppliger Anne , Concha-Lozano Nicolas , Hopf Nancy B , Niculita-Hirzel Hélène , Resch Grégory , Michaud Véronique , Dorange-Pattoret Laurie , Charrière Nicole , Batsungnoen Kiattisak , Suarez Guillaume
Published: October 2020

Introduction

During pandemics, such as the SARS-CoV-2, filtering facepiece respirators plays an essential role in protecting healthcare personnel. The recycling of respirators is possible in case of critical shortage, but it raises the question of the effectiveness of decontamination as well as the performance of the reused respirators.

Method

Disposable respirators were subjected to ultraviolet germicidal irradiation (UVGI) treatment at single or successive doses of 60 mJ/cm2after a short drying cycle (30 min, 70°C). The germicidal efficacy of this treatment was tested by spiking respirators with two staphylococcal bacteriophages (vB_HSa_2002 and P66 phages). The respirator performance was investigated by the following parameters: particle penetration (NaCl aerosol, 10–300 nm), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry and mechanical tensile tests.

Results

No viable phage particles were recovered from any of the respirators after decontamination (log reduction in virus titre >3), and no reduction in chemical or physical properties (SEM, particle penetrations <5%–6%) were observed. Increasing the UVGI dose 10-fold led to chemical alterations of the respirator filtration media (FTIR) but did not affect the physical properties (particle penetration), which was unaltered even at 3000 mJ/cm2(50 cycles). When respirators had been used by healthcare workers and undergone decontamination, they had particle penetration significantly greater than never donned respirators.

Conclusion

This decontamination procedure is an attractive method for respirators in case of shortages during a SARS pandemic. A successful implementation requires a careful design and particle penetration performance control tests over the successive reuse cycles.
Students’ perceptions on their use of an EHR: pilot questionnaire study
Authors: Ellis Beverley S , Quayle Susan , Bailey Ian , Tishkovskaya Svetlana , Spencer Joseph , Richardson Robin
Published: October 2020

Introduction

Many clinical education programmes have not incorporated the use of the electronic health record (EHR) into their curriculum. It is important to incorporate technologies that will be used in real-world settings to better prepare students for clinical practice.

Objectives

To undertake a review of literature to identify a training evaluation framework; to conduct a self-completion survey, pretraining and post-training, to determine students’ perceptions on the benefit of using EHR training system.

Setting

Nursing School, University, North West England, UK; University Ethic Committee Approval Received.

Participants

Registered nurses undertaking a validated return to practice course; 24 participants for the first cohort who completed pretraining questionnaire and 23 for the second post-training cohort.

Results

The statistical results show that the students perceived that the training improved their capability in employing digital systems with statistically significant difference in the assessed preproficiency and post proficiency in the use of digital clinical systems (premedians and post medians are 2 and 5 on 10-point Likert scale, p=0.041). There was also an indication of an improvement in the knowledge of EHR systems although not statistically significant. Most students perceived it increased their knowledge on digital systems.

Conclusion

Students perceived an increase in proficiency with the EHR. There was evidence of improvement in confidence in the use of the EHR, but this confidence would be enhanced by additional use of the system. Some desire to increase confidence further and to develop knowledge of digital systems was expressed.
Atrial fibrillation dashboard evaluation using the think aloud protocol
Authors: de Lusignan Simon , Liyanage Harshana , Sherlock Julian , Ferreira Filipa , Munro Neil , Feher Michael , Hobbs Richard
Published: October 2020

Background

Atrial fibrillation (AF) is a common cardiac arrhythmia which is a major risk factor for stroke, transient ischaemic attacks and increased mortality. Primary care management of AF can significantly reduce these risks. We carried out an evaluation to asses the usability of an AF dashboard developed to improve data quality and the quality of care.

Method

We developed an online dashboard about the quality of AF management for general practices of the Oxford Royal College of General Practitioners Research and Surveillance Centre network. The dashboard displays (1) case ascertainment, (2) a calculation of stroke and haemorrhage risk to assess whether the benefits of anticogulants outweigh their risk, (3) prescriptions of different types of anticoagulant and (4) if prescribed anticoagulant is at the correct dose. We conducted the think aloud evaluation, involving 24 dashboard users to improve its usability.

Results

Analysis of 24 transcripts received produced 120 individual feedback items (ie, verbalised tasks) that were mapped across five usability problem classes. We enhanced the dashboard based on evaluation feedback to encourage adoption by general practices participating in the sentinel network.

Conclusions

The think aloud evaluation provided useful insights into important usability issues that require further development. Our enhanced AF dashboard was acceptable to clinicians and its impact on data quality and care should be assessed in a formal study.
Effectiveness of virtual reality-based gait education in enhancing the rehabilitation outcomes of injured military personnel
Authors: Houston Andrew David , Coppack R J , Bennett A N
Published: October 2020

Introduction

Correcting adverse biomechanics is key in rehabilitating musculoskeletal injuries. Verbal instruction remains the primary method for correcting biomechanics and therefore a patient’s understanding of these instructions is believed to directly influence treatment outcomes. The aim of this study was to establish the patients’ perceptions of virtual reality-based gait education (VR-GEd) and to assess its influence on the standard military rehabilitation outcomes.

Methods

A retrospective analysis using routinely collected data was performed. Twenty patients with lower-limb musculoskeletal injuries undertook a VR-GEd session on the commencement of a 3-week, multidisciplinary, inpatient course of rehabilitation. Patient outcomes were compared with a group of matched controls, completing the same standardised course of inpatient treatment.

Results

The VR-GEd group exhibited greater reductions the interference pain had on their mood (p=0.022). Improvements in generalised anxiety (p=0.029) were greater in the VR-GEd group but were not large enough to be clinically meaningful. VR-GEd did not influence functional outcomes. Patients rated the sessions highly in terms of enjoyment and perceived value. Patient feedback highlighted that they understood their injury better and felt the session could positively influence their recovery.

Conclusion

VR-GEd was proven to be an enjoyable and valued means of educating military inpatients about their injury mechanics. This study found no contraindications for the inclusion of VR-GEd in current rehabilitation programmes. However, current evidence suggests a single VR-GEd session cannot act as a replacement for biofeedback interventions, due to the lack of enhanced improvement across rehabilitation outcomes.
Simulation-based education programme for upskilling non-critical care nurses for COVID-19 deployment
Authors: Almomani Emad , Sullivan Jacqueline , Hajjieh Majed , Leighton Kim
Published: October 2020

Background

The coronavirus disease 2019 (COVID-19) crisis created pressure on healthcare institutions to be prepared with maximum workforce and bed capacity. Clinical education during COVID-19 has high risk of disease transmission to learners due to contamination of equipment, supplies and surfaces, in addition to increased clinical-related stress and fear. Simulation-based education (SBE) has potential to help manage the pandemic by rapidly upskilling nurses’ clinical responsibilities.

Methods

Upskilling of 445 non-critical care nurses was conducted using SBE between 14th March and 30 May 2020. Training consisted of completing a mandatory online critical care awareness module, followed by 3 hours of critical care simulation-based scenarios using demonstration and return-demonstration approach.

Results

All 445 non-critical care nurses completed required modules and simulation experiences. The critical care simulation-based upskilling programme was evaluated as an effective way to learn how to manage critically ill patients. The majority of evaluation items were rated over 95% for effectiveness of the education; four items were less than 95% (88–94%). Lower rated items considered training and practice time, improved competency and commitment to apply learning.

Conclusion

Rapidly developed and implemented upskilling of critical care nurses was effectively accomplished with SBE. However, learners noted the need for longer learning times and increased practice opportunity to improve competency. Lack of intent to apply the patient care techniques requires further study. SBE has potential as an effective educational method for rapid preparedness in future crisis.
Total knee arthroplasty under quadruple nerve block with ropivacaine 0.32%: effect of addition of intravenous dexmedetomidine to intravenous dexamethasone on analgesic duration
Authors: Chassery Clement , Marty Philippe , Rontes Olivier , Chaubard Martine , Vuillaume Corine , Basset Bertrand , Merouani Mehdi , Marquis Constance , De Lussy Anne , Delbos Marie-Claude , Casalprim Julie , Bataille Benoit , Naudin Cecile , Ferre Fabrice , Delbos Alain
Published: October 2020

Background and objectives

Peripheral nerve blocks reduce postoperative pain and enhance recovery after total knee arthroplasty (TKA). This study aims to assess the benefits of addition of intravenous dexmedetomidine (DexM) to intravenous dexamethasone on the analgesic duration of quadruple nerve blocks.

Methods

This double-blind, randomized, controlled trial prospectively enrolled 90 patients scheduled for TKA under quadruple nerve blocks (sciatic, femoral, obturator, and lateral femoral cutaneous nerves blocks) with 70 mL, 0.32% ropivacaine. All patients received systemic dexamethasone 10 mg. Patients were randomized to receive DexM (2 µg/kg, intravenous) or placebo (1:1 ratio). The primary endpoint was the duration of analgesia defined as the time to first request for rescue analgesia (oxycodone).

Results

Kaplan-Meier curves for the first analgesic request were similar between groups (log-rank test; p=0.27). Median (IQR) duration of analgesia was similar between placebo (1575 min (1211–1952)) and DexM (1470 min (1263–1700)) groups (p=0.56). Cumulative consumption of oxycodone at the 48th hour was 20 mg (10–30) and 30 mg (20–40) in placebo and DexM groups, respectively (p=0.14). The day after surgery, 93% and 89% of patients were able to walk in placebo and DexM groups, respectively (p=0.46). Intravenous DexM was associated with bradycardia, hypotension and longer recovery room stay (p<0.05 for all comparisons).

Conclusions

In a multimodal analgesic regimen, addition of systemic DexM (2 µg/kg) to systemic dexamethasone does not prolong the analgesic duration of quadruple nerve block with ropivacaine 0.32% after TKA.

Trial registration number

NCT03834129.
Canine acute eosinophilic dermatitis with oedema (Wells‐like syndrome) associated with T‐cell multicentric lymphoma
Authors: Alves Pedro , Foale Robert , Cerundolo Rosario , Valls Sànchez Ferran
Published: October 2020

A nine‐year‐old female neutered Boxer in clinical remission from T‐cell multicentric lymphoma was presented for further investigation of multiple, non‐painful, non‐pruritic, oedematous, erythematous, serpiginous plaques. On examination, a very mild right superficial cervical lymphadenomegaly was also detected. Initial glucocorticoid treatment for a suspected hypersensitivity reaction was unsuccessful and the patient presented a week later with worsening of the dermatological signs. Cytology of peripheral lymph nodes was consistent with lymphoma relapse. Histopathology of skin biopsies was compatible with canine acute eosinophilic dermatitis with oedema, also known as Wells‐like syndrome. Complete clinical resolution of the skin lesions and the peripheral lymphadenomegaly was achieved with six weeks of lomustine chemotherapy. To the authors’ knowledge, this is the first description of canine acute eosinophilic dermatitis with oedema suspected to be triggered by a multicentric lymphoma in a dog.
Emerging insights in weight management and prevention: implications for practice and research
Authors: Doucet Eric , Hall Kevin , Miller Andrea , Taylor Valerie H. , Ricupero Maria , Haines Jess , Brauer Paula , Gudzune Kimberly A. , House James D. , Dhaliwal Rupinder
Published: October 2020

Recent advances in foundational research on energy balance and weight loss shed new light on earlier findings. Emerging evidence and insights around mental illness and client-centred, weight-inclusive approaches have implications for practitioners. This paper provides an overview of opinions from invited experts who presented at the Canadian Nutrition Society Thematic Conference in January 2019.

Novelty: Weight loss involves an interplay of multiple factors, not diet alone. There is no “best diet” or treatment approach for weight loss. Future research should involve minimizing weight loss countermeasures and new health system-based approaches aimed at improving health.
Sugars in space: a quantum chemical study on the barrierless formation of dihydroxyacetone in the interstellar medium
Authors: Kong Aristo , Guljas Andrea , Csizmadia Imre G. , Fournier René , Fiser Béla , Rágyanszki Anita
Published: October 2020

Among many theories on the life’s origins, the regions between star systems in a galaxy are hypothesized to provide prebiotic material on Earth. Simple sugars, including glycolaldehyde, are confirmed to exist in interstellar medium (ISM) and can be intermediates in the formose reaction to form dihydroxyacetone (DHA). In the studied segment of the formose reaction, hydroxy carbene is sequentially added to formaldehyde, forming glycolaldehyde (hydroxyacetaldehyde) after the first addition and glycerone in the second addition. The proposed theoretical mechanism was validated through quantum chemical calculations. An exothermic and exergonic pathway favourable in ISM conditions was found, giving a possible explanation for glycerone formation. The products in question participate in biological processes like energy production, the phosphorylated form of glycerone (DHA-P) participates in glycolysis, and energy storage while glycerone is the source of the glycerine backbone in lipids. The studied reaction is a segment of the formose reaction and further polymerization can lead to pentose and hexose, which participate in the formation of RNA and DNA. Hence, this research explores the exogenous production and delivery of prebiotic material to Earth, building up to the conditions allowing the formation of rudimentary lifeforms.
Competition among juvenile brown trout, grayling, and landlocked Atlantic salmon in flumes — predicting effects of interspecific interactions on salmon reintroduction success
Authors: Hagelin Anna , Bergman Eva
Published: October 2020

Worldwide declines in salmonid populations have generated major interest in conservation and restoration of wild populations and riverine habitats. Species reintroductions to previous habitats raise questions about their potential impact on these systems. In River Klarälven, landlocked Atlantic salmon (Salmo salar) have been extinct from upper reaches for over 50 years due to hydropower dams. Here we study competitive interactions among juvenile salmon, grayling (Thymallus thymallus), and brown trout (Salmo trutta) that occur in the upper reaches of the river. We examine foraging rates, aggression, and activity of juvenile fish in allopatry at three different densities and in sympatry with one or both potential competitors in laboratory flumes. Salmon captured prey less frequently in the presence of brown trout and grayling, whereas grayling and brown trout were unaffected by salmon, but affected each other. Grayling was the most aggressive and active species, whereas salmon the least. Consequently, reintroduction of salmon probably will have little impact on grayling and brown trout, whereas grayling and brown trout could affect the success of reintroducing salmon.
A biocompatible technique for magnetic field sensing at (sub)cellular scale using Nitrogen-Vacancy centers
Authors: Bernardi Ettore , Moreva Ekaterina , Traina Paolo , Petrini Giulia , Ditalia Tchernij Sviatoslav , Forneris Jacopo , Pastuović Željko , Degiovanni Ivo Pietro , Olivero Paolo , Genovese Marco
Published: October 2020

We present an innovative experimental set-up that uses Nitrogen-Vacancy centres in diamonds to measure magnetic fields with the sensitivity of $\eta =68\pm 3~\mathrm{nT}/\sqrt{\mathrm{Hz}}$
η
=
68
±
3

nT
/

Hz

at demonstrated (sub)cellular scale. The presented method of magnetic sensing, utilizing a lock-in based ODMR technique for the optical detection of microwave-driven spin resonances induced in NV centers, is characterized by the excellent magnetic sensitivity at such small scale and the full biocompatibility. The cellular scale is obtained using a NV-rich sensing layer of 15 nm thickness along z axis and a focused laser spot of $(10 \times 10)~\mu\mathrm{m}^{2}$
(
10
×
10
)

μ

m
2

in x-y plane. The biocompatibility derives from an accurate choice of the applied optical power. For this regard, we also report how the magnetic sensitivity changes for different applied laser power and discuss the limits of the sensitivity sustainable with biosystem at such small volume scale. As such, this method offers a whole range of research possibilities for biosciences.
Context-Dependent Feature Values in Text Categorization
Authors: Dang Edward Kai Fung , Luk Robert Wing Pong , Allan James
Published: October 2020

Feature engineering is one aspect of knowledge engineering. Besides feature selection, the appropriate assignment of feature values is also crucial to the performance of many software applications, such as text categorization (TC) and speech recognition. In this work, we develop a general method to enhance TC performance by the use of context-dependent feature values (aka term weights), which are obtained by a novel adaptation of a context-dependent adjustment procedure previously shown to be effective in information retrieval. The motivation of our approach is that the general method can be used with different text representations and in combination of other TC techniques. Experiments on several test collections show that our context-dependent feature values can improve TC over traditional context-independent unigram feature values, using a strong classifier like Support Vector Machine (SVM), which past works have found to be hard to improve. We also show that the relative performance improvement of our method over the context-independent baseline is comparable to the levels attained by recent word embedding methods in the literature, while an advantage of our approach is that it does not require the substantial training needed to learn word embedding representations.
Serial Verb Constructions
Authors: Lovestrand Joseph
Published: October 2020

In a serial verb construction (SVC), two or more verbs combine in a single clause without any morphosyntactic marking of linking or subordination. However, the way in which different linguists interpret and diagnose this description is a continual source of controversy. There are different assumptions about the nature of verbhood and clausehood as well as disagreements over how to interpret morphosyntactic marking in particular languages. Despite the fuzzy nature of the category, SVCs are often found to have similar functions in many languages—for example, to express closely linked sequences of events; to indicate directional and prior motion; to show concurrent aspects of a single event, such as posture, alongside another activity; and to express particular semantic roles or aspectual meaning. The morphosyntactic complexity and diversity found in SVCs continue to challenge conceptions of the clause that are assumed in both generative and comparative approaches to syntax.