bluuebunny/crossref_metadata_2025 huggingface dataset:
An Impedance-Control Based Teleoperation System for Live-Line Maintenance Robot
Authors: Wang Yang , Wu Hui , Mai Xiaoming
Published: September 2021

Robotic operation is an effective way to upgrade the live-line maintenance safety, efficiency, and quality. This paper proposes an impedance control-based teleoperation system to improve the adaptability of live-line maintenance robot in outdoors environment. The key technology of this system is utilizing three virtual spring-damper systems to model the elastic connection between the end-effector of slave manipulator and the environment, between the end-effector of slave manipulator and the counterpart of master haptic device, and between the end-effector of master haptic device and its base, respectively. Experiment results show that, under control of our proposed teleoperation system, the slave manipulator is able to track the motion of master haptic device and the robot is able to complete a set of complex action to peel the coat off the cable.
Prediction of Process Parameters of New Injection Molding Products Based on Historical Qualified Product Data
Authors: Niu Shiyin , Yu Junhe , Zhan Hongfei , Wang Rui
Published: September 2021

In the field of thermoplastic injection molding, there are a large number of qualified product data, mining and analyzing these data is of great significance to enterprise production. At present, most scholars do optimization research around given process parameters, and cannot fundamentally solve the problem of process parameter setting values. To this end, this article proposes a new method, through the analysis of the material, structure and process of historical qualified products, from the perspective of the product, find the factors that affect the process parameters, and use the BP neural network model to train the non-linear mapping relationship between the product and several main process parameters, and predict the main process parameter values of the new product. For inexperienced manufacturers of injection products, this method can greatly improve their productivity.
Grey-Box Technique of Software Integration Testing Based on Message
Authors: TanLi Mengqing , Zhang Ying , Wang Yulin , Jiang Yan
Published: September 2021

In the software integration testing, the combined exploding problem was appeared for GUI (Graphic User Interface) software with many advantages. Based on the engineering thinking of staging and the feature of GUI software, the grey technique of integration testing for GUI Software based on message is proposed to solve this problem, in which, the white-box method is used to deal with the consistent and unified part and black-box method is mainly engaged to dispose the difficult and varied part of software testing. By analysis of basic GUI software, the application of this grey technique will improve the testing efficiency with 333% according to testing executed number, and the efficiency in terms of testing executed time will be 438%. An actual example in product quality monitoring software has verified the approach and its efficiency of the grey technique.
Design of Toxic Environment Monitoring System for Industrial Sites Based on Wireless Sensor Networks
Authors: Zhang Xinrong , Chang Bo
Published: September 2021

In view of the actual demand of toxic gas monitoring in the production, storage and use field environment of chemical enterprises, considering the large amount of monitoring data and the difficulty of real-time transmission of information, a toxic gas environment monitoring system is designed. The system based on low-power microcontroller chip CC2530 by using wireless sensor intelligent information processing and data communication technology, which evaluates and improves the ambient air conditions and provides theoretical basis and technical support. The sensor node collects the concentration data of CO, formaldehyde, ozone, SO2 and other toxic gases in real time, processes them and sends them to the receiving end. According to the stored data, the receiver monitors the air quality of the industrial production and storage environment in real time, and effectively solves the problems of complex wiring and maintenance difficulties of traditional cable sensors to reduce the risk of accidents or early warning and reduce the hazards of accidents. The test results show that the system has stable performance, can effectively detect industrial toxic environmental parameters, and can be widely used in various fields, especially in unattended or inaccessible environment for monitoring tasks.
Research of Adaptive Frequency Search Based on Dichotomy
Authors: Mao Weiwei , Zhu Ru , Jin Xiaoyu , Li Zonghao , Zhang Zhiguo
Published: September 2021

In order to solve the problem of finding out the frequency of signal through adaptive filter as soon as possible, the adaptive frequency search of adaptive filter has been focused in this paper. According to the change of the signal frequency, the proposed adaptive filter based on the technology of dichotomy decides the frequency of the input signal, realizes the narrowband filtering and the large dynamic variation of specific frequency signal. And the single frequency sinusoidal signal has been theoretically analyzed by the way of DTFT and discrete Fourier transform. Finally, the estimated value of the signal frequency has been preliminary measured by the method of DFT, then based on the characteristic of DFT, the dichotomy search for the real signal frequency has been designed so that the accuracy of frequency measurement would be guaranteed within 2Hz.
A flexible control system for reconfigurable assembly lines
Authors: Xiao Leicai , Jing Xinghui , Zeng Long , Liu Xueping
Published: September 2021

With the rising demand for customized and frequently updated products, the current assembly systems require a higher level of reconfigurability and flexibility. Thus we proposed a scheme of reconfigurable assembly line and hierarchical control system. To increase the flexibility of control systems, a communication method and control strategy is presented in this paper. This approach will endow the reconfigurable assembly system with flexibility by encapsulating the ladder diagram program and providing an external interface for the control software to call. This approach is validated with one assembly unit assembling shuttle valve, which takes 40s during the process. The control system can not only monitor the assembling process, but also control the action of the actuator via control panel or control commands.
The Control System and Application Based on ROS Elevating Fire-Fighting Robot
Authors: Gan Zhijian , Huang Guofang , Zhang Jing , Liu Xiaoming , Shan Chao
Published: September 2021

Nowadays, fire accident is happening frequently which brings serious damages to people’s lives and properties; at present, fire-fighting robot is unable to perform targeted fire-fighting and combustion source at high places has brought difficulties to fire control and fighting; therefore, fire-fighting and assistance are facing unprecedented challenges. In view of this, the paper researched and developed an automatic control system for elevating fire-fighting robot, so as to solve the key difficulties and problems for fire control and fighting of fire-fighting robots. The research target consists of three aspects, firstly, the system has realized the elevating fire control and fighting function; secondly, we have designed an automatic control system for elevating fire-fighting robot based on ROS structure; thirdly, the paper has established the automatic control strategy play for raise arm of the elevating fire-fighting robot featured with stable and controllable operation, so as to solve the problem of unsteadiness in the elevating process and speed up application and popularization of fire-fighting and disaster rescue of the fire-fighting robot.
Prototype of a Solar-powered Fix-winged Unmanned Aerial Vehicle
Authors: Li Ziheng
Published: September 2021

The usage of solar power is a plausible and environment-friendly solution to solve the problem of limited duration of operation of current Unmanned Aerial Vehicle (UAVs) in market. Based on the state-of-the-art experiments in integrating solar power into aircraft and the basic theoretical calculations, this study investigates an attempt to construct a remote control solar-panel powered autopilot fixed-wing aircraft with technology accessible for home crafting. The aircraft is designed to recharge itself using sunlight within the duration of its operation and execute certain simple autopilot routes. The success of this model sheds light for further research and investment in making small-scale aircrafts solar-powered.
Dynamic Characteristics Analysis of Cover System
Authors: Zong Xiaorui , Yu Wenhui , Rui Guangchao , Jia Haijie , Zhang Xiang
Published: September 2021

Up to now, although a lot of research has been done on the control algorithm of cover motion, no systematic analysis has been carried out on the trajectory planning of cover opening yet. In order to improve the dynamic characteristics of the cover in the process of cover opening, a velocity planning algorithm based on trigonometric function is proposed in this paper, which improves the poor smoothness of the acceleration curve of the traditional S-shaped feedrate planning algorithm. The simulation model of the cover system is established to verify the effectiveness of the algorithm, and the results show that the algorithm is effective.
Research on wheel rail system based on Dissipative Structure Theory
Authors: Zhou Suxia , Jiang Hua , Liu Jingyuan
Published: September 2021

At present, the research on wheel-rail system is usually to analyze a problem separately, and draw a conclusion through experiments and simulations. This analysis result has certain accuracy, but it often cannot meet the requirements of optimization analysis of wheel-rail complex system. In this paper, by analyzing the characteristics of openness, away from equilibrium and fluctuation of wheel-rail system, a method of constructing element set based on information entropy is put forward. Entropy is used as a parameter to find out the inflow trend of wheel-rail system, and negative entropy flow and positive entropy flow are input to keep the system stable and orderly. The viewpoint of system engineering is put forward for the optimization of wheel-rail system.
Design and Development of the Flammability Tester
Authors: Xu Xiaoguang , Zhang Qiang , Chen Jian , Zhang Dong , Mai Baohua , Deng Shaojun
Published: September 2021

Among the international toy safety standards and national toy safety standards, the types of toys which need to be tested for flammability include: toys to be worn on the head, toy disguise costumes, toys intended to be entered by children, soft filled toys, and different types of toys have different flammability test methods. Based on the different test requirements, combined with PLC control technology and the working principle of high performance step-in motor, a multi-function flammability tester of toys is designed and developed. The function design, structure design and control principle of the flammability tester are discussed. It is pointed out that the use of this tester can not only solve the difficult problems in the test work of toys, but also greatly improve the quality and efficiency of toy safety test, and improve the automation level of the test work.
Multi-objective Reliability Optimization Design of Planetary Transmission Cutter Mechanism
Authors: Zhang Huipeng
Published: September 2021

Traditional planetary cutter mechanism design needs repeated trial and verification to determine a design scheme that meets the given conditions, and the scheme is generally not the best; The conventional single objective optimization design usually only aims at a certain requirement to achieve a certain optimal performance, neglecting the optimal comprehensive performance of the product. In order to solve the above problems, the reliability theory and optimization design technology are applied, and the compact structure, transmission efficiency, transmission stability and bearing capacity of the planetary cutter mechanism are comprehensively considered. Taking the minimum volume, maximum efficiency and maximum coincidence degree of the mechanism as the objective function, a multi-objective optimization design mathematical model different from the existing models is established by using the safety factor method and other constraints, Matlab software is used for optimization calculation. The results show that compared with the conventional design, the volume of the multi-objective optimization design is reduced by 79.97% and the coincidence degree is increased by 2.64% under the premise of almost constant transmission efficiency; Compared with the conventional single objective optimization design, although the single index is not optimal, the indexes are more balanced and the optimization effect is obvious.
Research and Design of MES System for Intelligent Production Line of Prefabricated Building Components
Authors: Zhou FuLiang , Chen YaJuan
Published: September 2021

Due to the national mandatory requirements for building assembly rate, more and more production enterprises have invested in prefabricated building component production. Because of the low intelligence of production line and the lack of advanced production management system, the problems of component production in terms of standard, quality, efficiency and energy consumption are gradually revealed. Based on the information management, combined with the new generation of information technology, this paper studies the technology, functional requirements and system architecture of MES system of intelligent production line, in order to promote the fine management and information management and control of PC intelligent production line.
Optimized Design of Internal Mixing Nozzle for Asphalt Oil Based on Fluent
Authors: Tai Weiheng , Ge Rongyu , Fu Xiuli , Chen Liwen
Published: September 2021

The design of the nozzle has an important influence on the atomization effect of asphalt oil in the road maintenance process. Fluent is used to numerically analyze the atomization process of asphalt oil in an internal mixing nozzle. The physical model of the nozzle was established, and the influence of the gas inlet pressure on the atomization cone angle and the SMD of atomized droplets was discussed. At the same time, the SMD of atomized droplets in different cross-sections downstream of the nozzle was studied. The results show that with the increase of the gas inlet pressure, the atomization cone angle of the asphalt oil gradually increases first and then decreases, and the SMD of the droplets gradually becomes smaller. As the distance between the cross-section and the nozzle outlet becomes larger, the SMD of the droplets on the cross-section first gradually becomes smaller and then remains basically unchanged. According to this rule, it provides a reference for the design of the internal mixing nozzle.
Based on the QT embedded data acquisition system design
Authors: Wan Jun , Wang HuaJun , Wang ZhenHeng , Yang Yao , Ma Yu , Huang Cong
Published: September 2021

The design of embedded data acquisition system based on QT is to use QT for embedded development, which can develop a data acquisition system with low cost, good effect and high practicability. This design is composed of temperature and humidity acquisition system module, camera acquisition module, buzzer alarm module, motor and fan module. The debugging and verification of the embedded system show that the data acquisition system has perfect function and stable operation. It can better meet the needs of practical application. QT based embedded data acquisition system has the advantages of high efficiency and reliability.
Design of socket with load identification and control
Authors: Xu Kai , Li Yilong , Jiang Zisong , Feng Xianyu
Published: September 2021

Under the background of demand-side power management, one solution to the problem of seasonal and intermittent power shortages is to involve residential users. The power supply company can sense and control the energy-consuming equipment such as air conditioners and water heaters in residential users’ homes. A socket with load identification and control functions is designed in the article. Through this socket, it is possible to sense and control the loads such as air conditioners and water heaters connected behind it. The socket adopts a combination of “sensing core” and “measurement core”, uses an algorithm based on events and Gaussian model to identify the load, uses a magnetic latching relay for control, and has protection functions such as overvoltage and overcurrent. In terms of installation method, it is fully compatible with the 86-size ordinary panel sockets used in residential houses on a large scale, and has certain application value.
An intelligently controlled tilting drum type kitchen waste in-situ processing device
Authors: Rong Lishan , Yu Feng , Huang Yaqin , Chen Ziqian , Wang Xinyue , Shi Ling , Gong Wei
Published: September 2021

Aiming at food waste, this project designs a set of innovative equipment based on realtime monitoring of biochemical processes, high-efficiency microbial aerobic fermentation and intelligent control of scenes to realize the resource utilization of food waste in situ. Focusing on the temperature and oxygen concentration in the fermentation process of kitchen waste, the two major parameters in the biochemical process will be monitored and intelligently controlled by the monitor on the cloud platform to solve the main problems in the process of resource utilization of kitchen waste. The indicators of parameters are not monitored in time, the production cycle of aerobic fermentation is long, and the traditional experience is mainly based on manual problems. In the later stage, it can be made into a vehicle-mounted mobile device to carry out community services.
Safety Evaluation of Hydraulic Steel Gate Based on TOPSIS Model
Authors: Shi Y.J , Shao Y.Y , Zhang Z.M , Jiang Y , Qi L
Published: September 2021

The paper aims to evaluate the safety of spillway’s steel gates in Xiaoling Reservoir. The weight of each evaluation index was obtained by analytic hierarchy process. Based on the detected data, TOPSIS model was used to evaluate the safety of main components for each gate. And then the comprehensive safety evaluation for spillway’s gates was carried out on this basis. The results were as follows. The coating of supporting arm was thin for gate 1. The coating of main beam and supporting arm was thin for gate 2. The coating of supporting arm was thin and the corrosion was serious for gate 3. The order of the three gates safety was gate 2 > gate 1 > gate 3. The results can reveal the safety situation of the gates and provide a reference for engineering maintenance.
Features and differences between Desay SV and Ford in the solution of C-V2X Technology
Authors: He Anxiang
Published: September 2021

C-V2X (means cellular vehicle to everything) is a vehicle wireless communication technology based on cellular network. In the early days of V2X, it was mainly based on DSRC. Its full name is dedicated short range communication, a dedicated short-range communication technology. C-V2X technology supports various vehicle networking applications including vehicle, vehicle road, vehicle person and vehicle network through device to device and cellular communication. C-V2X is a global standard formulated by 3GPP organization, including lte-V2X and 5g-V2X. Among them, LTE-V2X mainly carries basic traffic safety business. The standard has been formulated since 2015 and R14 version has been released in 2017; 5g-V2X, based on 5g NR technology, is mainly aimed at carrying automatic driving business, and will be released in 3GPP R16 at the end of 2019. This paper will compare the characteristics of C-V2X technology solutions of Ford and Desay SV, and explore the differences between Desay SV and Ford in C-V2X technology solutions [1].
Research on resolution of underwater acoustic imaging
Authors: Wu YangShuang , Lv ZhiYong , Fang QingPing
Published: September 2021

In order to study the influence of underwater material on the resolution of acoustic imaging, the Rayleigh resolution limit is proposed for the acoustic imaging system. Based on the realization form of Bessel function, the theoretical calculation formula of sound field scattered by a rigid sphere is obtained. Based on the boundary element theory, the scattering sound field of the small ball is simulated by COMSOL software, and the feasibility of the simulation is verified. Finally, the applicability of Rayleigh resolution limit in acoustic imaging system is verified by underwater simulation experiment with sonar. The research results provide theoretical support for improving the resolution of underwater acoustic imaging, and have important guiding significance for the research and development of underwater detection equipment.
Design of Monitoring System for Urban Low-Lying Water
Authors: Chen Shuaihua , Wang Xiaoping
Published: September 2021

The Internet of things technology is applied to establish a low-lying ponding monitoring system, which includes information acquisition system and information management system. This GPRS, 4G, Java, Internet of things and large database technology are applying to build a data acquisition hardware platform. On this basis, the basic database of road ponding and the monitoring and early warning system of road ponding in low-lying land are established. Thus, the application requirements of road ponding information query, management, monitoring, water level change analysis and water level overrun alarm based on map are realized. At the same time, the control of relevant drainage facilities has been integrated. The modern management means of road low-lying land ponding monitoring has been improved. And the management and control level of municipal road ponding has been comprehensively improved.
Research and application of small target detection method
Authors: Wang Zhenheng , Wang Huajun , Wan Jun , Ma Yu , Huang Cong , Yang Yao
Published: September 2021

With the advent of the big data era, more and more data are used in image detection. In order to solve the problem of small target detection in traditional image detection algorithms, this paper proposes an improved target detection algorithm based on YOLO-v5. The algorithm proposes to connect two models in series, using the former model for target pre-positioning, and the latter model for target detection. This method trains two different model parameters, tests them separately, and finally connects them for target detection. The test results show that the improved algorithm improves the ability in small target detection, and at the same time has a speed advantage.
Environmental Engineering Deformation Control of High-speed Railway Shield Tunnel Under Crossing Bridge Piles
Authors: Wu Nan
Published: September 2021

With the continuous acceleration of my country’s high-speed rail construction, it is inevitable to cross the existing engineering structure during the construction process. During the construction of high-speed railway, the control of the influence and deformation of the existing structure is a subject that needs to be studied in environmental engineering. Hangzhou metro line 1 is designed to cross under the Hu-Hang high-speed railway. According to the design, the shield tunnel is very close (minimum distance 5.19m) to the bridge piles of the Hu-Hang high-speed railway. Therefore, how to control the deformation of the bridge piles is a big problem in the shield tunnel excavation. Before construction, the method of the bored piles coupled with the jet grouting piles was proposed. The 3D numerical model was built to study the deformation of the bridge piles with the cases of the shield tunnel excavation without soil consolidation, the construction of the bored piles coupled with the jet grouting piles and the shield tunnel excavation with soil consolidation. The results show that the method of the bored piles coupled with the jet grouting piles can control the deformation of the bridge piles in the shield tunnel excavation effectively. Then, the deformation monitoring of the bridge piles was performed in the process of construction. The monitored data were close to the calculated results, which implies that the method of the bored piles coupled with the jet grouting piles is effective.
Research on Drilling Depth Measurement Technology based on Drilling Rig Parameter Monitoring
Authors: Gao Jun
Published: September 2021

In view of the problem that the drilling depth is measured by manually counting drill pipes in the process of underground drilling construction in coal mine, combined with the multi-channel sensor parameters loaded on the parameter monitoring device of mining tunnel drilling rig, a new drilling depth measurement method is proposed. This method mainly relies on multiple pressure sensors assembled on the drilling rig to reflect different drilling rig operation states, and the drilling depth is obtained by increasing or decreasing the displacement parameters of the power head. It is suitable for tunnel drilling rig equipped with drilling rig parameter monitoring device. It not only saves hardware cost, but also adds a monitoring function of the device. At the same time, it provides a new technical path for accurate and reliable drilling depth measurement.
Effect of different inlet pressures of vortex tube on internal flow field
Authors: Xu Qijun , Xie Jing
Published: September 2021

Numerical simulations were used to investigate the distribution of the internal pressure, velocity, and temperature fields in the vortex tube (VOTU) at inlet pressures of 1-4 MPa to reveal the causes of temperature separation. A three-dimensional model with a nozzle flow channel number of 5 was drawn, and the simulation was performed in Fluent 19.0 with CO2 as the working fluid. The simulation results show that when the inlet pressure of the VOTU is greater than 2 MPa, the temperature separation between the hot and cold air streams of the VOTU gradually increases with the increase of the inlet pressure. The maximum temperature is 285 K and the minimum temperature is 257 K at an inlet pressure of 1.0 MPa, and the maximum temperature is 319 K and the minimum temperature is 243 K at an inlet pressure of 4.0 MPa. As the inlet pressure increases, the temperature difference inside the VOTU will also increase. In the high-pressure condition, the wall thickness and sealing degree of the VOTU design should be increased accordingly, while the inner wall side of the VOTU needs to use wear-resistant materials to delay the long-term scouring of the VOTU caused by high-speed airflow. The results of the study have certain guiding significance for the design and manufacture of VOTUs.
Analysis and Selection of Shipping Route in Ocean
Authors: Jie Junwu , Miao Congjin
Published: September 2021

This electronic document is a “live” template. Ocean navigation is a long-distance cross ocean navigation. There are three kinds of ocean routes in common use: great circle route, rhumb line route and mixed route. The great circle route is usually used when ships are sailing in the ocean, but sometimes in the mid latitude sea area, the rhumb line route is a choice in the mid latitude sea area. Combined with the calculation of a navigation example, this paper makes some analysis on the selection of ocean routes in mid latitude sea area, illustrates the advantages and disadvantages of these three ocean routes with data, and draws a conclusion on how to choose the routes.
Analysis of Flexible Plate Motion Based on Co-Simulation of STAR-CCM + and ABAQUS
Authors: Shu Linzhao , Yang Guang , Ji Nan , Qian Zhipeng
Published: September 2021

By the advantages of the fluid dynamics software STAR-CCM + and the structure simulation software ABAQUS in their respective fields, this paper adopts the FEM algorithm for structural deformation, and based on the RANS equation for fluid simulation, the accuracy of the co-simulation method of Fluid-Structure Interaction(FSI) was proved by comparing the simulation results under typical conditions with the experimental results. Then the deformations of a large flexible plate with fixed bottom end at high flow rate were numerically analyzed. The co-simulation method can obtain more accurate and detailed flow field and structural deformation, and has certain application value for related theoretical research, engineering structure design and safety evaluation.
In-pixel automatic threshold calibration for the CMS Endcap Timing Layer readout chip
Authors: Sun H. , Gong D. , Edwards C. , Huang G. , Huang X. , Liu C. , Liu T. , Liu T. , Olsen J. , Sun Q. , Wu J. , Ye J. , Zhang L. , Zhang W.
Published: September 2021

We present the implementation and verification of an
in-pixel automatic threshold calibration circuit for the CMS Endcap
Timing Layer (ETL) in the High-Luminosity LHC upgrade. The
discriminator threshold of the ETL readout chip (ETROC) needs to be
calibrated regularly to mitigate the circuit baseline
change. Traditional methods need a lot of communication through a
slow control system hence are time-consuming. This paper describes
an in-pixel automatic scheme with improvements in operating time and
usability. In this scheme, a sample-accumulation circuit is used to
measure the average discriminator output. A binary successive
approximation and linear combination scan are applied to find the
equivalent baseline. The actual calibration procedure has been first
implemented in FPGA firmware and tested with the ETROC front-end
prototype chip (ETROC0). The calibration circuit has been
implemented with Triple Modular Redundancy (TMR) and verified with
Single Event Effects (SEEs) simulation. A complete calibration
process lasts 35 ms with a 40 MHz clock. In the worst case, the
dynamic and static power consumption are estimated to be
300 μW and 10.4 μW, respectively. The circuit design,
implemented in a 65 CMOS technology, will be integrated into ETROC2,
the next iteration of the ETROC with a 16 × 16 pixel matrix.
Adaptations to High-Altitude Hypoxia
Authors: Beall Cynthia M. , Strohl Kingman P.
Published: September 2021

Biological anthropologists aim to explain the hows and whys of human biological variation using the concepts of evolution and adaptation. High-altitude environments provide informative natural laboratories with the unique stress of hypobaric hypoxia, which is less than usual oxygen in the ambient air arising from lower barometric pressure. Indigenous populations have adapted biologically to their extreme environment with acclimatization, developmental adaptation, and genetic adaptation. People have used the East African and Tibetan Plateaus above 3,000 m for at least 30,000 years and the Andean Plateau for at least 12,000 years. Ancient DNA shows evidence that the ancestors of modern highlanders have used all three high-altitude areas for at least 3,000 years. It is necessary to examine the differences in biological processes involved in oxygen exchange, transport, and use among these populations. Such an approach compares oxygen delivery traits reported for East African Amhara, Tibetans, and Andean highlanders with one another and with short-term visitors and long-term upward migrants in the early or later stages of acclimatization to hypoxia. Tibetan and Andean highlanders provide most of the data and differ quantitatively in biological characteristics. The best supported difference is the unelevated hemoglobin concentration of Tibetans and Amhara compared with Andean highlanders as well as short- and long-term upward migrants. Moreover, among Tibetans, several features of oxygen transfer and oxygen delivery resemble those of short-term acclimatization, while several features of Andean highlanders resemble the long-term responses. Genes and molecules of the oxygen homeostasis pathways contribute to some of the differences.
Care-seeking delay of imported malaria to China: implications for improving post-travel healthcare for migrant workers
Authors: Lu Guangyu , Cao Yuanyuan , Chen Qi , Zhu Guoding , Müller Olaf , Cao Jun
Published: September 2021

Background

Imported malaria cases continue to pose major challenges in China as well as in other countries having achieved elimination. Our study aims to identify the factors influencing the timing of care-seeking after symptom onset among migrant workers with imported malaria, in order to develop innovative interventions to improve access and provision of post-travel healthcare for returning migrants.

Methods

We analysed the timing and types of healthcare service utilization after symptom onset among patients with imported malaria between 2012 and 2019 in Jiangsu Province, China. Moreover, decision tree models were used to explore the factors influencing the care-seeking timing after symptom onset among patients with imported malaria.

Results

A total of 2255 cases of imported malaria were identified from 1 June 2012 through 31 December 2019. Patients with malaria imported into China were mainly male migrant labourers returning from sub-Saharan Africa (96.8%). A substantial number of patients with imported malaria sought healthcare >3 days after symptom onset, which clearly represented delayed healthcare-seeking behaviour. According to the decision tree analysis, initial healthcare seeking from healthcare facilities at higher administrative levels, infection with Plasmodium vivax and absence of malaria infection history were significantly associated with delayed healthcare seeking in patients with imported malaria.

Conclusion

The delay in seeking of medical care among migrant workers with imported malaria should be considered and addressed by specific interventions. In addition to increasing awareness about these issues among health care professionals, improved access to healthcare facilities at higher administrative levels as well as improved diagnostic capacity of healthcare facilities at lower administrative levels should be developed. Moreover, education programs targeting populations at risk of malaria importation and delayed healthcare seeking should be improved to facilitate early healthcare seeking and service use.
When to depart from a stopover site? Time since arrival matters more than current weather conditions
Authors: Roques Sébastien , Henry Pierre-Yves , Guyot Gaétan , Bargain Bruno , Cam Emmanuelle , Pradel Roger
Published: September 2021

On the journey to wintering sites, most migratory birds alternate between flights and stopovers, where they rest and refuel. In contrast to the time-minimization strategy commonly assumed to drive the pre-breeding migration, birds are rather expected to follow an energy minimization during post-breeding migration. It is the cumulative duration of flights and stopovers that determines the total energy requirements and duration of the journey. Since migrating birds actually spend most of the time at stopovers sites, selection to minimize the amount of energy or time spent on migration is likely to operate on the effectiveness of stopover rest and refueling. Here, we address the relative contribution of factors acting on departure decisions from a stopover site during the post-breeding migration in a long-distance migratory songbird. When capture probability is low, it is impossible to measure fattening over the entire duration of the stopover. To get around this limitation, we use time since arrival (TSA) as a proxy for the progressive temporal change occurring in the internal state of an individual (i.e. rest, physiological recovery, and fuel loading) during the stopover. We develop a capture–recapture model to address the respective effects of estimated TSA and of weather conditions on departure probability. Using a 20-year dataset for Sedge Warblers (Acrocephalus schoenobaenus), we show that TSA served as a surrogate of the most important information that birds use when deciding to depart from a stopover site, while low humidity and rising atmospheric pressure only slightly increase daily departure probability. Hence, a bird would resume migration mainly according to the time it had to rest and refuel, and then fine-tuning departure decision according to weather conditions. The generality of these results needs to be assessed by applying this modeling framework to other migratory species and at sites or times with greater weather variability.
Descriptions of Hearing Aids Influence the Experience of Listening to Hearing Aids
Authors: Rakita Lori , Goy Huiwen , Singh Gurjit
Published: September 2021

Objectives:

Experiences can be strongly influenced by expectations. In hearing healthcare, previous studies have shown that descriptions of hearing aids or contextual factors during the hearing aid fitting process can change subjective and even objective outcomes with hearing aids via the placebo effect. Personality factors have also been shown to affect susceptibility to placebo effects. The purposes of the present study were to (a) investigate the effects of communicating narratives designed to foster positive, negative, or neutral expectations about hearing aids on short-term patient outcomes, and (b) to determine if the degree to which the narratives affected end-user outcomes could be predicted by personality factors.

Design:

Nineteen adults between the ages of 54 and 81 (mean age = 68.5, SD = 8.9) had 3 separate research appointments, each exposing them to a different narrative condition: positive, negative, or neutral. the appointment was designed to look and feel like a “traditional” hearing aid fitting appointment, during which the experimenter introduced (i.e., the narrative condition) and fit a pair of hearing aids, the participant was asked to provide their initial feedback about the hearing aids, and the participant performed speech-in-noise testing. Unbeknownst to the research participant, the hearing aids fitted at all three appointments were the same, and the only difference between the three appointments was the way the hearing aids were described to the participants.

Results:

The results of this study showed that communication of a positive narrative about hearing aids before a hearing aid fitting led to better speech-in-noise performance on the QuickSIN as compared with performance following the negative or neutral narrative conditions. Also, the positive narrative led to the perception that acclimatization to the hearing aids would occur faster than the negative or neutral narrative conditions. Notably, the effect of communication of a positive narrative was stronger for individuals who scored higher on agreeableness, and susceptibility to positive and negative messaging was stronger for individuals low in neuroticism.

Conclusions:

The study suggests that short-term evaluations of hearing aids can be strongly influenced by narratives as provided by the hearing healthcare provider at the time of a hearing aid fitting.
Thiamine, Ascorbic Acid, and Hydrocortisone As a Metabolic Resuscitation Cocktail in Sepsis: A Meta-Analysis of Randomized Controlled Trials With Trial Sequential Analysis*
Authors: Assouline Benjamin , Faivre Anna , Verissimo Thomas , Sangla Frédéric , Berchtold Lena , Giraud Raphaël , Bendjelid Karim , Sgardello Sebastian , Elia Nadia , Pugin Jérôme , de Seigneux Sophie , Legouis David
Published: September 2021

OBJECTIVES:

Sepsis is a common condition in the ICU. Despite much research, its prognosis remains poor. In 2017, a retrospective before/after study reported promising results using a combination of thiamine, ascorbic acid, and hydrocortisone called “metabolic resuscitation cocktail” and several randomized controlled trials assessing its effectiveness were performed.

DESIGN:

We conducted a systematic review and meta-analysis of randomized controlled trials in septic ICU patients to assess the effects of this combination therapy.

SETTING:

PubMed, Embase, and the Cochrane library databases were searched from inception to March of 2021. Data were extracted independently by two authors. The main outcome was the change in Sequential Organ Failure Assessment score within 72 hours. Secondary outcomes included renal composite endpoints (acute kidney injury) Kidney Disease - Improving Global Outcome organization stage 3 or need for renal replacement therapy, vasopressor duration, and 28-day mortality.

SUBJECTS:

We included randomized controlled trials with patients admitted to the ICU with sepsis or septic shock.

INTERVENTION:

The trials compared a combination of thiamine, ascorbic acid, and hydrocortisone to standard care or placebo in patients admitted to ICU with sepsis or septic shock.

MEASUREMENTS AND MAIN RESULTS:

We included eight randomized controlled trials (n = 1,335 patients). Within 72 hours, the median of mean improvement was –1.8 and –3.2 in the control and intervention groups, respectively (eight randomized controlled trials, n = 1,253 patients); weighted mean difference –0.82 (95% CI, –1.15 to –0.48). Data were homogeneous and the funnel plot did not suggest any publication bias. Duration of vasopressor requirement was significantly reduced in the intervention group (six randomized controlled trials). There was no evidence of a difference regarding the ICU mortality and the renal composite outcome (acute kidney injury KDIGO 3 or need for renal replacement therapy, seven randomized controlled trials).

CONCLUSIONS:

Metabolic resuscitation cocktail administrated in ICU septic patients improves change in Sequential Organ Failure Assessment score within 72 hours. However, this improvement is modest and its clinical relevance is questionable. The impact on renal failure and mortality remains unclear.
Modified Gundersen Flap Using Inferior Palpebral–Bulbar Conjunctiva
Authors: Mekonnen Bethlehem , Kossler Andrea L. , Lin Charles C.
Published: September 2021

Purpose:

The purpose of this article was to describe a modification to the traditional Gundersen flap technique that expands eligible eyes to include those with severe conjunctival scarring and to report results from a clinical case.

Methods:

A 68-year-old woman with a history of herpes simplex keratitis, multiple failed penetrating keratoplasties, lagophthalmos, persistent epithelial defect, and low visual potential in the left eye presented for the evaluation of a Gundersen flap. Severe superior bulbar conjunctival scarring precluded a traditional approach. A modified Gundersen flap technique using a contiguous flap of inferior palpebral–bulbar conjunctiva extending from the inferior tarsal border to the limbus was devised and performed.

Results:

The modified Gundersen flap technique successfully stabilized the ocular surface, obviating the need for a cosmetically disfiguring permanent tarsorrhaphy or an evisceration.

Conclusions:

This modified Gundersen flap technique expands the indications to eyes with severe conjunctival scarring and can be offered in eyes with previous trabeculectomies, glaucoma drainage implants, and scleral buckles, which were previously excluded from the globe-preserving option.
Deep Learning for Discrimination Between Fungal Keratitis and Bacterial Keratitis: DeepKeratitis
Authors: Ghosh Amit Kumar , Thammasudjarit Ratchainant , Jongkhajornpong Passara , Attia John , Thakkinstian Ammarin
Published: September 2021

Purpose:

Microbial keratitis is an urgent condition in ophthalmology that requires prompt treatment. This study aimed to apply deep learning algorithms for rapidly discriminating between fungal keratitis (FK) and bacterial keratitis (BK).

Methods:

A total of 2167 anterior segment images retrospectively acquired from 194 patients with 128 patients with BK (1388 images, 64.1%) and 66 patients with FK (779 images, 35.9%) were used to develop the model. The images were split into training, validation, and test sets. Three convolutional neural networks consisting of VGG19, ResNet50, and DenseNet121 were trained to classify images. Performance of each model was evaluated using precision (positive predictive value), sensitivity (recall), F1 score (test's accuracy), and area under the precision–recall curve (AUPRC). Ensemble learning was then applied to improve classification performance.

Results:

The classification performance in F1 score (95% confident interval) of VGG19, DenseNet121, and RestNet50 was 0.78 (0.72–0.84), 0.71 (0.64–0.78), and 0.68 (0.61–0.75), respectively. VGG19 also demonstrated the highest AUPRC of 0.86 followed by RestNet50 (0.73) and DenseNet (0.60). The ensemble learning could improve performance with the sensitivity and F1 score of 0.77 (0.81–0.83) and 0.83 (0.77–0.89) with an AUPRC of 0.904.

Conclusions:

Convolutional neural network with ensemble learning showed the best performance in discriminating FK from BK compared with single architecture models. Our model can potentially be considered as an adjunctive tool for providing rapid provisional diagnosis in patients with microbial keratitis.
TearCare for the Treatment of Meibomian Gland Dysfunction in Adult Patients With Dry Eye Disease: A Masked Randomized Controlled Trial
Authors: Gupta Preeya K. , Holland Edward J. , Hovanesian John , Loh Jennifer , Jackson Mitchell A. , Karpecki Paul M. , Dhamdhere Kavita
Published: September 2021

Purpose:

The aim of this study was to demonstrate the safety and effectiveness of a single TearCare procedure compared with a single LipiFlow procedure in treatment of the dry eye disease associated with meibomian gland dysfunction.

Methods:

In a multicenter, masked, randomized controlled trial, 135 subjects received a single TearCare (TC) treatment (n = 67) or a single LipiFlow (LF) treatment (n = 68) at baseline and were followed up for 1 month posttreatment. Tear film breakup time, meibomian gland function, and corneal and conjunctival staining scores were assessed as dry eye signs at baseline, 2 weeks, and 1 month; dry eye symptoms were assessed using the Ocular Surface Disease Index, Symptom Assessment in Dry Eye, and eye dryness questionnaires at baseline and 1 month.

Results:

At 1 month posttreatment, both groups demonstrated significant improvements (P < 0.0001) in mean tear film breakup time and meibomian gland secretion score to 3.0 ± 4.4 and 11.2 ± 11.1 in the TC group and 2.6 ± 3.3 and 11.0 ± 10.4 in the LF group, respectively. The mean eye dryness, Symptom Assessment in Dry Eye, and Ocular Surface Disease Index scores were significantly reduced (P < 0.0001) by 35.4 ± 34.1, 38.2 ± 31.0, and 27.9 ± 20.5 in the TC group and 34.9 ± 26.9, 38.0 ± 25.9, and 23.4 ± 17.7 in the LF group, respectively. There were no statistically significant differences for any result between the groups. However, the TC group demonstrated numerically greater improvements consistently in all signs and symptoms. Device-related ocular adverse events were reported in 3 patients in the TC group (superficial punctate keratitis, chalazion, and blepharitis) and 4 patients in the LF group (blepharitis, 2 cases of foreign body sensation, and severe eye dryness).

Conclusions:

A single TearCare treatment significantly alleviates the signs and symptoms of dry eye disease in patients with meibomian gland dysfunction and is equivalent in its safety and effectiveness profile to LipiFlow treatment as shown in this 1-month follow-up study.
Balancing Training Opportunities and Patient Outcomes
Authors: Mughal Maleeha , Sleiwah Aseel , Townley William
Published: September 2021

Microvascular free tissue transfer is the criterion standard of reconstruction post–oncological resections of the head and neck region. We present a consultant's first 200 consecutive microvascular head and neck reconstructions in independent practice. A retrospective analysis of a prospectively collected database of all head and neck reconstructions performed in the first 3 years of practice was performed. These included 200 consecutive microvascular head and neck reconstructions performed by a single surgeon at a tertiary referral center. We review the results and complications in this series and discuss factors significant for successful outcomes in head and neck reconstruction. We also highlight that different parts of the surgery in the majority of cases were performed by a trainee under the supervision of the senior surgeon and thus discuss the need for training future plastic surgeons with an interest in head and neck reconstruction.