bluuebunny/crossref_metadata_2025 huggingface dataset:
Four‐phase interleaved TCM DC‐DC buck converter with matrix inductor in battery charging application
Authors: Nguyen Anh Dung , Chen Shu‐Xin , Chen Yang , Chen Cheng‐Wei , Han Byeongcheol , Lai Jih‐Sheng
Published: December 2020

In this paper, a 1‐kW DC‐DC buck converter with a four‐phase interleaved matrix inductor is proposed for battery charging applications. It is well‐known that the DC bias on the inductor will cause high core loss as it changes the B–H characteristic. Typically, the transient conduction mode employed in high voltage applications for zero‐voltage‐switching of devices would cause higher inductor current ripple. The conventional approach to reduce the effect of DC bias and inductor current ripple is employing multi‐phases. However, the cost and size of the converter will increase significantly. This paper proposes the matrix inductor which has a small volume and reduces the effect of the DC bias by flux sharing and flux cancellation at the same time, results in low inductor core loss. With the interleaved operations the output current ripple can be lower which is suitable for battery charging application. Besides, the comparison of the synchronous and interleaved operation is presented. A 1‐kW prototype is built and the experimental results show that the peak efficiency is 99.1% and 99.2% for synchronous and interleaved control, respectively. Additionally, the output current ripple of the interleaved operation is reduced by 85% in comparison with the synchronous operation.
Voltage unbalances mitigation in bipolar DC microgrids using a novel three‐port multidirectional buck–boost converter
Authors: Ahmadi Taha
Published: December 2020

This study proposes a new three‐port multidirectional DC‐DC converter (TMC) to integrate an energy storage system (ESS) or main grid to a bipolar DC microgrid (BDCMG). This converter provides a voltage balancing function and controls the input and output power of the BDCMG so that during overload conditions injects power to the BDCMG and in low‐load conditions saves the available power to an ESS or transfers to the main grid. Given this integration of activities, the total number of converters in the BDCMG can be decreased. This feature enables that the converter can be used in portable systems where the overall efficiency and weight of the system are important. In the study, the performance of the proposed converter is analysed. Simulation studies are performed and a BDCMG laboratory setup is implemented in order to evaluate the performance of the proposed TMC.
Space‐vector current control of cascaded half‐bridge three‐phase three‐wire voltage source inverter
Authors: Rawa Muhyaddin , Belkamel Hamza , Bassi Hussain , Abusorrah Abdullah , Mekhilef Saad
Published: December 2020

Current controllers for voltage source inverters give better control of current waveform and also provide compensation for load transients and non‐linearities. Despite the increasing employment of multilevel inverters in high‐power medium voltage applications and its superior performance compared to two‐level inverters, the extension of hysteresis current controllers to multilevel voltage source inverters is much less established. In this study, a current error space vector‐based hysteresis controller is implemented on a three‐phase cascaded half‐bridge voltage source inverter. The vector‐based method measures the current error in a space vector form and keeps the error within the assigned tolerance region. It has been observed from the simulation tests and experimental verifications that the implemented current regulator maintains the load current as close as possible to the set reference current with a significantly minimised error. Another attractive feature in the implemented closed‐loop current controller is that the number of voltage levels is maintained as the output of the inverter with a fast dynamic response.
Design of a switched‐capacitor boost converter utilizing magnetic coupling with capability of right‐half plane zero elimination
Authors: Goudarzian Alireza , Mirzaeian Dehkordi Behzad , Abjadi Navidreza , Adib Ehsan
Published: December 2020

The dynamic operation of the conventional boost converters is limited in the continuous conduction mode, due to the presence of
at least one right‐half plane (RHP) zero in their control transfer function which can limit the open‐loop bandwidth of the converter. This problem complicates the control design for the output voltage regulation and conversely influences the closed‐loop system stability. To cancel this problem, a new step‐up boost converter using the magnetic coupling and the switched capacitor (SC) is presented. In the proposed converter the effect of the RHP zero can be successfully eliminated, the voltage transfer ratio can be enhanced and the circumstances are provided to reach a small operating duty cycle as well as stress reduction of the diodes and power switch. Using the averaging technique, the state‐space model of the converter is analytically studied and the essential conditions are given for achieving a minimum‐phase structure. Based on the mentioned advantage, a simple classical PI controller for the output voltage regulation is designed. To confirm the theoretical analysis of the proposed converter, simulations and practical results are presented. Also, the performance of the proposed converter is compared with the other boost converters without RHP zero.
Undervoltage compensation of pantograph catenary arc
Authors: Zou Dan Dan , Wang Meng Yao , Hu Ping Zi , Cui Chunmei
Published: December 2020

This paper describes the design of a new type of pantograph-catenary arc simulation test device and simulation of the arc generated by the pantograph during operation under laboratory conditions. The influence of the burning position of the pantograph-catenary arc on the overvoltage of the traction system is studied. Corresponding suppression measures for the arcs are proposed, and the dynamics of the arc processes are carried out by theoretical simulation. The characteristics of the pantograph-catenary arc and the discharge process are analyzed, and the relationship between the characteristics of the pantograph and the arc is explored.
Ta/CoFeB/MgO analysis for low power nanomagnetic devices
Authors: Riente F. , Mendisch S. , Gnoli L. , Ahrens V. , Roch M. Ruo , Becherer M.
Published: December 2020

The requirement of high memory bandwidth for next-generation computing systems moved the attention to the development of devices that can combine storage and logic capabilities. Domain wall-based spintronic devices intrinsically combine both these requirements making them suitable both for non-volatile storage and computation. Co\Pt and Co\Ni were the technology drivers of perpendicular Nano Magnetic Logic devices (pNML), but for power constraints and depinning fields, novel CoFeB\MgO layers appear more promising. In this paper, we investigate the Ta2\CoFeB1\MgO2\Ta3 stack at the simulation and experimental level, to show its potential for the next generation of magnetic logic devices. The micromagnetic simulations are used to support the experiments. We focus, first, at the experimental level measuring the switching field distribution of patterned magnetic islands, Ms via VSM and the domain wall speed on magnetic nanowires. Then, at the simulation level, we focus on the magnetostatic analysis of magnetic islands quantifying the stray field that can be achieved with different layout topologies. Our results show that the achieved coupling is strong enough to realize logic computation with magnetic islands, moving a step forward in the direction of low power perpendicularly magnetized logic devices.
Effect of applied magnetic field on permeability and heating efficiency of multifunctional micro/nano-magnetic particles for hyperthermia therapy
Authors: Tonthat Loi , Yamamoto Yoshiyuki , Mitobe Kazutaka , Yabukami Shin
Published: December 2020

Hyperthermia using magnetic particles is a very promising cancer therapy. In previous studies, we developed a mixture of magnetic micro/nanoparticles with high heating efficiency for tumor treatment and considerable change in permeability around therapeutic temperature for monitoring its temperature and position during heating. In this study, we examined experimentally the effect of applied magnetic field on the heating and permeability properties of the proposed mixture by manipulating the amplitude and frequency (H = 1.8–7.1 kA/m, f = 500 kHz, and H = 4.8 kA/m, f = 200–1000 kHz). It was found that the specific absorption rate (SAR) of the mixture increased with the amplitude and frequency (SAR α H1.68×f). Its intensity of magnetization (μ0M) at 20°C changed linearly with the amplitude, whereas it remained almost unchanged with the frequency. The results obtained here may enable us to find the optimal conditions of the applied magnetic field and the amount of magnetic particles required to treat a tumor of a given size.
Development of android-based learning module in metal fabrication techniques for vocational high school 2 Klaten
Authors: Nuryanto A , Erestio D , Pamungkas A , Pratiwi H
Published: December 2020

This study aims to develop an android-based learning module and find out the level of feasibility of learning module development in vocational high school 2 Klaten. This study uses ADDIE models, which are analysis, design, development, implementation, and evaluation. This study involved 37 respondents (students) to determine the feasibility of the android-based learning module that was developed. Data was obtained by the questionnaire and analysed by changing the average score into a percentage. The result of this study was android based learning module products on metal fabrication techniques subject for XI grade students. The feasibility test showed that the feasibility level of learning module validated by media experts obtained 77.90% with the category of eligible. The feasibility validated by material experts showed an overall average of 86.39% with the category very eligible, and from the results of the user obtained an overall average of 78.53% with the eligible category. From the feasibility test it could be concluded that the android module development could be used as one of the learning media in metal fabrication subject.
Multimedia interactive learning of pictorial projection mechanical engineering skills in vocational high schools
Authors: Pardjono P , Syauqi K , Prasetya W A , Baihaqi S
Published: December 2020

This research aims to develop interactive learning multimedia for learning pictorial projection in Mechanical Engineering Drawing. This study is a research and development using the ADDIE development model, namely: Analysis, Design, Development, Implementation, and Evaluation. The results of the material expert’s assessment on the material quality aspect received a percentage of 86.25% in the Very Appropriate category, and on the aspect of material benefit, a percentage of 75% was obtained in the Eligible category. The results of the media expert’s assessment on the program design aspect received a percentage of 90% in the Very Appropriate category, and in the multimedia design aspect, a percentage of 86.9% was obtained in the Very feasible category. The media developed was tested on 35 students of class X Vocational High School 2 Klaten. The results of the trial on students got a percentage of 80.33% in the Very feasible category. Thus the pictorial projection learning multimedia was feasible to use as a learning medium for class X Vocational High Schools in mechanical engineering expertise.
The development of turning machine module in vocational high school 2 Yogyakarta
Authors: Pratiwi H , Andreas E , Paryanto P , Wijayanti A N
Published: December 2020

This study has been conducted in order to produce a learning module of lathe machining in vocational high school 2 Yogyakarta. Furthermore, the feasibility of the module and the user response are also evaluated. The method that used in this research was research and development using 4D model. The instrument collection data used in this research was questionnaire. Questionnaire is used at the stage of validation and assessment product by experts and students as product user. From the feasibility test, it could be concluded that the learning media produced is in very feasible level based on all validation score from material expert lecture, material expert teacher, learning media expert lecturer, and students as users.
Job profile of welding and machining in the ship industry of Penataran Angkatan Laut Company Indonesia
Authors: Sugiyono S , Syauqi K , Badranaya M I , Nugraha Y
Published: December 2020

This study aims to describe the Penataran Angkatan Laut company’s modern shipping industry’s job profile and its relevance to the Mechanical Engineering Education Study Program curriculum, Faculty of Engineering, Yogyakarta State University 2014. The research is focused on the job profile of a welder level for the field welding and operator level for the machining plane. The research was conducted using a descriptive qualitative model with the research subject of Penataran Angkatan Laut company Indonesia Surabaya, East Java. Data collection techniques used include interviews, documentation, and observation. The data is then analyzed using the percentage method—checking the validity of the data used triangulation of sources and techniques. This study’s results indicate that the curriculum is a relevant category in the welding field with a 64.74% value and 91.67%, a very relevant category in machining.
Optimization of pocket cycle machining process in computer numerically controlled milling machining
Authors: Wijanarka B S , Sutopo S , Widarto W , Nuchron N , Sitorus T P W , Pranyoto A Y
Published: December 2020

The objectives of this study were: (1) to analyze the ratio of the time required for the roughing process of making a pocket (pocket) from several different strategies for the roughing process, and (2) to analyze the wear of cutting tools for the roughing process of making a pocket from several kinds of roughing cutting method. The research method used was experiment. The materials used are the work piece of mild steel (ST37) and the cutting tool HSS End mill with a diameter of 10 mm with 2 flutes. The machine used was a CNC milling machine and the software used was Master Cam X7. Retrieval of data using a built-in time-measuring instrument, vernier caliper, micrometer, and a digital micrometer with a magnification of 600x to 1000X. Data were analyzed by comparing the time required for each cutting method (8 kinds of methods) on CADCAM and the time on the actual CNC milling machine. The results showed: the fastest time required for roughing the pocket size 80 mm x 80 mm in 6 mm was the zigzag cutting method with straight-in feed (41 minutes 46.68 seconds in the CAM simulation and 42 minutes in machining using a CNC Milling machine), and the longest time is the true spiral cutting method with a ramping in-feed (62 minutes 20.59 seconds in the Master Cam X7 simulation and 62 minutes 21 seconds in the machining process using a CNC Milling machine). The wear of tools for the zigzag cutting method is greater than the true spiral cutting method. The optimization of the pocket making process in a CNC milling machine is calculated based on time and wear, if machining time is the goal, the zigzag cutting method is chosen and if the durability of the cutting tool is the goal, the true spiral cutting method is chosen.
Kinesthetic intelligence in welding practice lectures
Authors: Marwanto A , Wibowo Y E , Djatmiko R D , Wijaya R C
Published: December 2020

This study aims to determine the student’s kinesthetic intelligence, the level of student’s kinesthetic intelligence and to measure the relationship between kinesthetic intelligence and the learning outcomes of welding practice lectures in the Undergraduate Program of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University. The method used is a survey. The research was carried out in the Undergraduate Program of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University. The research was conducted from April to July 2020. The research subjects were students of the 2018 batch of Undergraduate Program of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University. The research variables are students’ linguistic intelligence (independent) and the learning outcomes of welding practice lectures (dependent). The results showed that the students’ verbal-linguistic intelligence was 72.02%. 6.49% or as many as 5 students make kinesthetic intelligence the highest value compared to other intelligence. The significance value (Sig.) Is 0.416 and greater than 0.05, so it can be concluded that Ha is rejected, and H0 is accepted with kinesthetic intelligence that does not have a significant effect on the learning outcomes of students in the Undergraduate Program of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University. The value of R Square is 0.011, which means that the influence of kinesthetic intelligence possessed by students (X) on learning outcomes of welding practice students of the Undergraduate Program of Mechanical Engineering Education, Faculty of Engineering, Yogyakarta State University (Y) is only 1.1% while 98.9% is influenced by other variables.
Automatization of fog lamp based on LED sensor and photo dioda
Authors: Ratnawati Dianna , Purnomo Sigit , Handoyono Nurcholish Arifin , Subagyo  , Suyitno
Published: December 2020

Accidents due to misuse of fog lamps are traffic violations. To help minimize the misuse of fog lamps, the automatic fog lamp design is indispensable for car drivers to be applied directly to vehicles that still use manual fog lamps. This study aims to produce the design / prototype automatic fog lights with control LED and photo diode sensors that can work effectively, efficiently and economically and is able to function when the fog began to emerge through the simulation of CO2 solid (dry ice). This research method uses experiments with implementation stages including (1) designing an automatic fog lamp circuit, (2) simulating the validity of the design, (3) refining the design until the final design is obtained, (4) product manufacturing, (5) product testing, (6) automatic fog lamp prototype. Design media using PCB (Printed Circuit Board). While the main components needed are batteries, switches, resistors, LEDs, photo diodes, transistors, relays, fog lamps, and cables. From the test results, the automatic fog lamp circuit design with the substitution of the light sensor is able to turn the fog lamp on and off automatically. The efficient distance for placing the LED and photo diode is 4.5 cm. Thus, the LED-based automatic fog lamp and photo diode can be used as an alternative to support the safety factor for vehicle users.
Developing Wiper and Washer System Electronics Learning Module for Automotive Engineering Education Students
Authors: Kurniawan H A , Siswanto I , Sampurno Y G , Sudarwanto  , Syafiq A
Published: December 2020

This research aims to develop and determine the feasibility of wiper and washer electronics learning module for Automotive Engineering Students. The development method consists of seven stages including (1) problem analysis, (2) product design, (3) product development, (4) product trials, (5) product revisions, (6) trial test, and (7) final product. The module were validated by two material experts and two media experts. Furthermore, there were 30 students participated in the trial tests. The results of this study is the electronics learning module of the wiper and washer system with a file size of 30.6MB and APK package format so that it can be operated using an android with a minimum specification of 2GB RAM. Electronics learning module contains basic theories, animations, and quizzes of the wiper and washer system. The expert validation showed that the content is very good (120) and the appearance is good (91), while the students who try to use the module rated it as very feasible (123.97). The result indicates that the electronics module of wiper and washer system are feasible to use and need to be implemented for further action research.
Design and Torsional Rigidity Analysis on Frame of Formula Garuda 17 Based on Student Formula Japan 2017 Rules
Authors: Arifin Z , Yoga I N , Zain J F
Published: December 2020

The objective of this study are to: (1) Produce the design of the Formula Garuda 17 car that complies with Student Formula Japan 2017. (2) Produce the frame design of the Formula Garuda 17 car that has a torsional rigidity that can withstand bending and twisting loads. The type of research used is research and development, also known as R & D, and the development model of the Formula Garuda 17 car frame, which is a model for developing Analysis, Design, Development, Implementation, and Evaluation (ADDIE). The results showed that the frame design was in accordance with Student Formula Japan 2017 regulation, and the torsional rigidity value met the target of 1,026.7NM / degree while the Factor of safety value in the bending force was 3.3 so that this frame was categorized as safe for the race.
The Development of Computer-Based Personality and Social Competency Test Questions for Teacher Professional Education (TPE) Participants Automotive Engineering
Authors: Martubi  , Suhartanta  , Yudantoko A
Published: December 2020

The purpose of this study is to develop a computer-based personality and social competency test questions. This research was carried out with a research and development approach to the Borg and Gall model by simplifying the steps according to the needs and situations that affect the timing of this research, especially the occurrence of the Covid-19 pandemic outbreak. To analyze the quality of the results of this development, the Anates 4.0 program was used, and validity analysis was also carried out using the product-moment correlation coefficient test statistical technique, while the reliability of the items was tested by calculating the Cronbach Alpha correlation coefficient. The results of this study are: (1) the development of computer-based personality and social competency test questions for TPE participants with automotive engineering expertise is carried out through five stages, (2) the main steps in the process of creating a computer program for this personality and social competency in general consist of four stages, (3) the items of the personality and social competency test items have met the requirements, either through rational analysis of the material, construction and language aspects as well as empirical analysis which includes validity, reliability, difficulty level and distinguishing power, although there are still some items that need to be improved.
The Development of Training Kit For Basic Electronic Control on Automotive Field
Authors: Tafakur  , Sukaswanto  , Solikin M , Wardani F R
Published: December 2020

This study aims to determine: (1) the material needed by students in the Basic Practice of Electronic Control Systems in the automotive field, (2) the design of the Basic Electronic Control System Training Kit in the automotive field, (3) the results of the development of the Basic Electronic Control System training kit in the automotive field., (4) eligibility of the basic training kit for the Electronic Control System in the automotive sector, and (5) users responses to the development results of the Basic Electronic Control System training kit. This study uses the research and development (RND) method. The research was carried out in 5 stages, namely: (1) the needs analysis stage, (2) the product design stage, (3) the product development stage, (4) the product use implementation stage, and (5) the product evaluation stage. Retrieval of data using documentation and questionnaires. The results showed that: (1) The materials needed by students in the basic practice of automotive electronic control systems include: understanding the use of simulation software, functions, arrays and looping on Arduino, serial communication, use of LCDs, use of interrupts, use of analog to digital converters, infrared sensor, ultrasonic sensor, pulse width modulation, lookup table function and EEPROM data writing, and arduino applications in the automotive sector; (2) The development product of the training kit is in the form of educational props containing parts of the power supply system, various kinds of input variations, the process system with Arduino Uno, and the output section in the form of lamps, buzzers, electric motors, solenoids, 7 segment displays, LCD, relays, and driver transistor. The model is packaged in a box for individual or group learning of 2-3 people; (3) The developed training kit was declared very feasible according to media experts and material experts; (4) The developed training kit received a positive response from users/students.
Medical Instrument Skill Competency in Vocational High Schools Based on Legal Rules in Indonesia
Authors: Purwanto  , Pardjono
Published: December 2020

The application of electronic instrument technology to the health sector requires more detailed quality assurance and is guaranteed in the use, maintenance, repair and/or development of medical instrument devices. Improving the quality and quantity of medical instrument needs to be supported by an increase medical instrument personnel. This research was conducted to examine more about Indonesian medical/electromedical instrument personnel, specifically at vocational high school level in 2020 in an effort to overcome the challenges of the development of instrumental technology in the health sector. The lack of medical instrument personnel must be completed immediately without leaving its quality. Currently, there are regulations regarding the implementation of medical instrument education at the vocational high schools level, but vocational high schools are still constrained by regulations regarding the minimum qualifications for medical instrument education in the applicable regulations. This condition causes vocational high schools to date to have not implemented competency in medical device expertise even though it has been mapped on the spectrum of ministries. In fact, regulations serve as guarantees of operation quality, guarantee of competency criteria, guarantee of work quality, and guarantees for medical instrument personnel.
Design of seed paper coaster for sustainable engineering and environmental education in kaxabu niumian community
Authors: Peng Li-Hsun , LIN Ai-Yung , Indarti
Published: December 2020

The consumption of natural resources in the world is increasing. People consume a lot of energy in daily products, such as air and water, cause soil pollution, consumption of natural resources, and the Kaxabu Niumian tribe from a natural pollution-free environment the current excessive development and disintegration of agricultural waste materials. Therefore, it is necessary to understand and promote the entire educational process of new environmental protection technologies. Through the learning of school science and technology education, everyone can inspire ideas, starting from the community and school’s environmental education, making products that do not harm the environment, and continue to operate the environmental technology market through technology to improve the living environment. The material used in this product’s design is made of natural bamboo or environmentally friendly PVA material shared in the community, so there is almost no burden on the environment. The principle of use will be made through diversified geometric shapes and high-pressure forming of customized shapes. Starting from elementary school education, the primary school students collect water drops on the coaster to become a small potted plant. The water resources are recycled, and the coaster has new functions. This product design principle is taught as a whole set of environmental protection and sustainable engineering methods. The ultimate goal of this research is to integrate technology into education to understand the use of environmentally friendly materials in life, achieve innovative and sustainable energy technologies, and promote environmental awareness.
Learning media using the tie-dye technique
Authors: Rahmania Sera Syarifah , Triyanto Triyanto
Published: December 2020

The ready to wear clothes are developed through two stages, namely clothes designing and producing based on Martello Fort. The process of designing starts with first, the designing process which includes studying the references (idea, style, look), constructing the mood board, sketching, and designing motif. Then, producing which includes: a) preparation stage involving creating the work design, measuring the size, making the 1:4 scale pattern and the large pattern, designing the material, and estimating the product price; b) implementation stage involving creating the abstract motive using tie-dye technique, placing the pattern on the materials, cutting, adding stitching lines, basting stitching and sewing; and c) evaluation stage involving evaluation process I, evaluation process II, and final evaluating of the result. The result of the study is in the form of design of ready to wear abstract motive clothes inspired by Martello Fort. The design has a T silhouette consisting of three pieces, namely: a dress, obi belt, and jacket. The production of ready to wear clothes is not as simple as what it seems since this high-quality concept has an elegant and edgy design. The clothes are targeted for fearless urban teenagers within the middle and upper classes because most of these classes are interested in high-quality products and trend changes.
Overturns the traditional craftsmanship of seediq tribe’s fashion design with sustainable engineering and educational technology
Authors: Peng Li-Hsun , Chung Pei-Shan , Kieu Tran Thi Minh
Published: December 2020

The Seediq, who possessed superb weaving skills, was forced to move to Chuanzhong Island (Qingliu tribe) after the Wushe incident in the 1930s. The Japanese banned weaving, coupled with the rapid development of the textile industry at that time, leading to the ramie weaving culture disappearing in the tribe for nearly 50 years. Therefore, this research will combine the weaving patterns of the Seediq tribe with fashion design through design, a fusion of traditional and modern design elements, and give the work unique cultural creativity and fashion flavor. In the hope that through design education, we will learn about tribal products and permanent Continue the value of the business and circular economy, create a tribal fashion culture, complete a series of innovative design works of the Seediq, and achieve the research purpose of sustainable engineering and technology.
Utilization of Virtual Laboratory “Calculation of Motor Vehicle Exhaust Emissions” to Study Air Pollution
Authors: Widowati Asri , Setuju  , Utami Danik Noor
Published: December 2020

Air pollution is a crucial problem that must be minimized because air is a major component in life. One of the causes of air pollution is the result of exhaust gas emissions from motorized vehicles. Therefore, calculating motor vehicle exhaust emissions is one of the important things that students must master to foster environmental awareness. Efforts to make mathematical learning of the calculation of exhaust gas emissions interesting and fun, namely by using virtual laboratory media. In this case, discussed how the virtual media packaging Laboratory “Motor Vehicle Exhaust Emission Calculation” to study Air Pollution
SARS–CoV-2 Receptor ACE2 Gene Is Associated with Hypertension and Severity of COVID 19: Interaction with Sex, Obesity, and Smoking
Authors: Hamet Pavel , Pausova Zdenka , Attaoua Redha , Hishmih Camil , Haloui Mounsif , Shin Jean , Paus Tomas , Abrahamowicz Michal , Gaudet Daniel , Santucci Lara , Kotchen Theodore A , Cowley Allen W , Hussin Julie , Tremblay Johanne
Published: December 2020

BACKGROUND

Angiotensin-converting enzyme 2 (ACE2) has been identified as the entry receptor for coronaviruses into human cells, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19). Since hypertension (HT) is a leading comorbidity in non-survivors of COVID-19, we tested for association between ACE2 gene and HT in interaction with specific pre-existing conditions known to be associated with COVID-19 severity.

METHODS

Genetic analysis of ACE2 gene was conducted in French-Canadian (FC) and British populations.

RESULTS

In FC individuals, the T allele of the single nucleotide polymorphism rs2074192 of ACE2 gene was a risk factor for HT in adult obese males [odds ratio (OR) = 1.39, 95% confidence interval (CI) 1.06–1.83)] and even more so in obese males who smoked (OR = 1.67, CI: 1.24–2.55), but not in lean males, non-smoker males or females. The T allele was significantly associated with severity of HT and with earlier penetrance of HT in obese smoking males. Significant interaction between the T allele and obesity was present in both sexes. The association of ACE2 (rs233575) genotype with blood pressure was also seen in adolescents but the interaction with obesity was present only in females. Several variants in ACE2 gene were found to be associated with HT in obese, smoking males in British individuals of the UK Biobank. In addition, we observed more severe outcomes to COVID-19 in association with ACE2 risk alleles in obese, smoking males.

CONCLUSIONS

This is the first report that ACE2 variants are associated with earlier penetrance and more severe HT and with more severe outcomes of COVID-19 in obese smoking males.
UPLC–MS/MS for the Simultaneous Determination of Sildenafil and N-Desmethyl Sildenafil
Authors: Zhu Wen Ling , Zheng Chao , Xiong Wen Gang , Chen Cai Li , Yi Jin Ling , Zhang Xiu Jin , Luo Xi
Published: December 2020

A sensitive high-performance liquid chromatography–tandem mass spectrometry method was established for the simultaneous determination of sildenafil and N-desmethyl sildenafil in human plasma. The protein precipitation was used for extraction and the gradient elution of the mobile phase A of water (containing 0.01% formic acid) and the mobile phase B of acetonitrile, and methanol (V:V = 1:1, containing 0.01% formic acid) was used for chromatographic separation on a C18 column. Quantification was performed by multiple reaction monitoring mode to monitor the precursor-to-product ion transitions of m/z 475.4 → m/z 283.3 for sildenafil, m/z 461.4 → m/z 283.2 for N-desmethyl sildenafil, m/z 483.3 → m/z 108.1 for sildenafil-d8 (IS) and m/z 469.2 → m/z 283.3 for N-desmethyl sildenafil-d8 (IS) at the positive ionization mode. The intra- and inter-day relative standard deviations were less than 6.8% and 4.1% for sildenafil and N-desmethyl sildenafil, respectively. Accuracy at four levels ranged from 93.1% to 115.9% for sildenafil and 95.6% to 112.5% for N-desmethyl sildenafil. The present method was sensitive and reliable for simultaneous quantification of sildenafil and its active metabolite and was successfully applied to a pharmacokinetic study of an oral low dose of sildenafil in Chinese healthy volunteers.
‘The War Rages On’: Expanding Concepts of Decolonization in International Law
Authors: Storr Cait
Published: December 2020

The Battle for International Law is a forceful collection that addresses the seismic challenges to the international legal order posed by the formal decolonization movements of the mid-20th century. The editors borrow from Reinhart Koselleck to frame the decades between the Bandung Conference in 1955 and the declaration of a New International Economic Order in 1974 as a Sattelzeit, or ‘bridging period’, between two eras of Western domination. The concept provides a coherent, flexible frame for a strong field of 19 chapters, organized around concepts, institutions, protagonists and regional perspectives emblematic of the period in question. At a time when exhibitionist defences of colonialism and imperialism are resurgent, this collection’s solidarist restatement of key themes of Third World Approaches to International Law (TWAIL) and Marxist international law is timely. However, in reproducing international law’s long-critiqued statist concept of decolonization, the editors effectively consign the politics of decolonization to the past, and to the South. This does not reflect contemporary debates on the meaning of decolonization as an on-going struggle with material and epistemic dimensions. As a result, the volume leaves a crucial question open for consideration: How might contemporary international lawyers conceive of their relationship to decolonization, understood not as an era of the 20th century, but as an unresolved challenge for the 21st?
Determinants of out-of-district health facility bypassing in East Java, Indonesia
Authors: Putri Nuzulul Kusuma , Wulandari Ratna Dwi , Syahansyah Robeth Jabbar , Grépin Karen A
Published: December 2020

Background

Several large-scale reforms, including policies aimed at achieving universal health coverage, have been implemented to overcome health disparities in Indonesia. However, access to health services remains unequal. Many people ‘bypass’ health services in their home district to access health services in neighbouring districts, even though their health insurance does not cover such services. This study aims to identify the factors that are associated with this out-of-district bypassing behaviour.

Methods

We surveyed 500 respondents living in the outermost districts of East Java province. We used data on education, income, district, age, gender, household size, district accessibility, insurance coverage status and satisfaction with health facilities in the home district and logistic regression analysis to model the predictors of out-of-district health facility bypassing.

Results

The most important predictors of the bypassing behaviour were education and poor access to health facilities in the home district. Open-ended data also found that the most important reason for seeking care in another district was mostly geographic. In contrast, health insurance coverage does not appear to be a significant predictor.

Conclusions

Education and geographic factors are the main predictors of out-of-district bypassing behaviour, which appears to be how border communities express their health facility preferences. Local and central governments should continue their work to reduce inequality in access to health facilities in Indonesia's geographically challenged districts.
Parasitism and Predation on Sentinel Egg Masses of Three Stink Bug Species (Hemiptera: Pentatomidae) in Native and Exotic Ornamental Landscapes
Authors: Cornelius Mary L , Herlihy Megan V , Vinyard Bryan T , Weber Donald C , Greenstone Matthew H
Published: December 2020

This study evaluated parasitism and predation on sentinel egg masses of three stink bug species, the spined soldier bug, Podisus maculiventris (Say), the brown stink bug, Euschistus servus (Say), and the invasive brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), in ornamental landscapes composed of either native or exotic plants. This study also compared the species composition of parasitoids attacking two native stink bug species (P. maculiventris and E. servus) with those attacking the invasive BMSB on the same tree species in the same habitat. Overall, egg parasitism and predation were much higher on the two native stink bug species compared with BMSB, with an average parasitism rate of 20.6% for E. servus, 12.7% for P. maculiventris, and only 4.2% for H. halys and an average predation rate of 8.2% for E. servus,17.7% for P. maculiventris, and 2.3% for H. halys. Egg predation was also significantly higher on P. maculiventris than on E. servus eggs. Eight parasitoid species attacked sentinel stink bug eggs in the ornamental landscaped plots. Trissolcus euschisti (Ashmead) (Hymenoptera: Scelionidae) was the predominant parasitoid for all three stink bug species. There were no significant differences in parasitism and predation rates on any of the stink bug species between native and exotic plots. Therefore, there is no evidence that ornamental landscapes composed of native plants increased parasitism or predation rates of sentinel egg masses of two native stink bug species or the invasive BMSB, compared with those composed entirely of exotic plants.
Potential Efficacy of Multimodal Mixed Reality in Epilepsy Surgery
Authors: Iizuka Kazuki , Sato Yosuke , Imaizumi Yohichi , Mizutani Tohru
Published: December 2020

BACKGROUND

Mixed reality (MR) technology, which can fuse things in real and virtual space in real time, has been used mainly for simulation in neurosurgical training.

OBJECTIVE

To develop MR technology into multimodal MR for intraoperative guidance during epilepsy surgery.

METHODS

A 33-yr-old male patient suffered from intractable general tonic seizures due to left temporal meningoencephalocele. Preoperative scalp electroencephalograms localized interictal epileptic activity on the left temporal lobe. Iomazenil single photon emission tomography revealed temporal lobe lateralization. Magnetic resonance imaging (MRI) demonstrated left basal temporal meningoencephalocele extending into the pterygopalatine fossa through a bone defect at the base of the greater sphenoid wing. A 3-dimensional model was created for MR based on multimodal data including computed tomography, MRI tractography, and digital subtraction angiography, which enabled 3-dimensional visualization of abnormal subcortical fiber connections between the meningoencephalocele and the epileptic focus.

RESULTS

By using intraoperative multimodal MR, we were able to safely remove the meningoencephalocele and perform epileptic focus resection. The patient was seizure-free postoperatively, and no adverse effects were noted.

CONCLUSION

Intraoperative multimodal MR was a feasible and effective technique, and it can be applied for a wide range of epilepsy surgeries.
Socioeconomic factors and the probability of death by Covid-19 in Brazil
Authors: De Negri F , Galiezz R , Miranda P , Koeller P , Zucoloto G , Costa J , Farias C M , Travassos G H , Medronho R A
Published: December 2020

Background

To design better measures to contain the Covid-19 epidemics, it is relevant to know whether socioeconomic factors are associated with a higher risk of death by Covid-19. This work estimates the effects of individual socioeconomic characteristics on the risk of death by Covid-19.

Methods

Logistic models were estimated to assess the effect of socioeconomic characteristics (income, race/ethnicity, schooling, occupation and economic activity) on the risk of death from Covid-19. For this purpose, Covid-19 individual death records in Rio de Janeiro state, Brazil were combined with the Annual Register of Social Information, which contains socioeconomic information about formal workers.

Findings

Workers employed in establishments in the health and public safety sectors present a risk of dying 2.46 and 2.25 times higher than those employed in other activities. Non-white people, men, and those who work in the Metropolitan Region are also more likely to die from Covid-19. People with higher education are 44% less likely to die from the disease.

Conclusions

Some population groups are more vulnerable to the Covid-19 pandemic and individual socioeconomic conditions play a relevant role in the probability of death by the disease. That should be considered in the design of prevention policies to be adopted.
Global Health Education in the Time of COVID-19: An Opportunity to Restructure Relationships and Address Supremacy
Authors: Rabin Tracy L. , Mayanja-Kizza Harriet , Barry Michele
Published: December 2020

Global health and its predecessors, tropical medicine and international health, have historically been driven by the agendas of institutions in high-income countries (HICs), with power dynamics that have disadvantaged partner institutions in low- and middle-income countries (LMICs). Since the 2000s, however, the academic global health community has been moving toward a focus on health equity and reexamining the dynamics of global health education (GHE) partnerships. Whereas GHE partnerships have largely focused on providing opportunities for learners from HIC institutions, LMIC institutions are now seeking more equitable experiences for their trainees. Additionally, lessons from the COVID-19 pandemic underscore already important lessons about the value of bidirectional educational exchange, as regions gain new insights from one another regarding strategies to impact health outcomes. Interruptions in experiential GHE programs due to COVID-19-related travel restrictions provide an opportunity to reflect on existing GHE systems, to consider the opportunities and dynamics of these partnerships, and to redesign these systems for the equitable benefit of the various partners. In this commentary, the authors offer recommendations for beginning this process of change, with an emphasis on restructuring GHE relationships and addressing supremacist attitudes at both the systemic and individual levels.
The changing landscape of nephrology physician assistants and nurse practitioners
Authors: Davis Jane , Zuber Kim
Published: December 2020

Background:

Physician assistants (PAs) and nurse practitioners (NPs) have expanded roles in nephrology as both the patient load and acuity of care needed for this population have increased.

Purpose:

To evaluate workforce patterns of PAs and NPs working in nephrology over the past decade.

Methods:

Using the biannual survey from the National Kidney Foundation Council of Advanced Practitioners, data were collected and analyzed over the past decade.

Results:

Surveys of nephrology practitioners show the evolution of the dialysis-centralized practitioner to one encompassing all aspects of nephrology: hospital, intensive care unit, research, office, and all types of dialysis. Salaries and benefits have increased to compensate for the expansion of responsibilities.

Implications for practice:

Physician assistants and NPs in nephrology have the opportunity to use their skills and training in caring for this high-risk population.
Physical Therapy Management of Children With Developmental Coordination Disorder: An Evidence-Based Clinical Practice Guideline From the Academy of Pediatric Physical Therapy of the American Physical Therapy Association
Authors: Dannemiller Lisa , Mueller Melinda , Leitner Adrah , Iverson Erin , Kaplan Sandra L.
Published: December 2020

Background:

Developmental coordination disorder (DCD), classified as a neurodevelopmental disorder in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), affects approximately 5% to 6% of school-aged children. Characteristics of DCD include poor motor coordination and delayed development of motor skills, not explained by other conditions. Motor deficits negatively affect school productivity, performance in activities of daily living, and recreation participation. Children with coordination problems, at risk for or diagnosed with DCD, should be evaluated by a team of professionals, including a physical therapist (PT).

Purpose:

This clinical practice guideline (CPG) provides management strategies for PTs and informs clinicians and families about DCD. It links 13 action statements with specific levels of evidence through critical appraisal of the literature and provides recommendations for implementation.

Results/Conclusions:

The DCD CPG addresses examination, referral, first choice and supplemental interventions, discharge, compliance audits, implementation, and research recommendations. Supplemental tools are provided to support PT management.