bluuebunny/crossref_metadata_2025 huggingface dataset:
Blockchain Applications to Improve Operation and Security of Transportation Systems: A Survey
Authors: Khoshavi Navid , Tristani Gabrielle , Sargolzaei Arman
Published: March 2021

Blockchain technology continues to grow and extend into more areas with great success, which highlights the importance of studying the fields that have been, and have yet to be, fundamentally changed by its entrance. In particular, blockchain technology has been shown to be increasingly relevant in the field of transportation systems. More studies continue to be conducted relating to both fields of study and their integration. It is anticipated that their existing relationships will be greatly improved in the near future, as more research is conducted and applications are better understood. Because blockchain technology is still relatively new as compared to older, more well-used methods, many of its future capabilities are still very much unknown. However, before they can be discovered, we need to fully understand past and current developments, as well as expert observations, in applying blockchain technology to the autonomous vehicle field. From an understanding and discussion of the current and potential future capabilities of blockchain technology, as provided through this survey, advancements can be made to create solutions to problems that are inherent in autonomous vehicle systems today. The focus of this paper is mainly on the potential applications of blockchain in the future of transportation systems to be integrated with connected and autonomous vehicles (CAVs) to provide a broad overview on the current related literature and research studies in this field.
The Characteristics of Aluminum-Gallium-Zinc-Oxide Ultraviolet Phototransistors by Co-Sputtering Method
Authors: Huang Wei-Lun , Chang Sheng-Po , Li Cheng-Hao , Chang Shoou-Jinn
Published: March 2021

In this thesis, Aluminum-Gallium-Zinc oxide (AGZO) photo thin film transistors (PTFTs) fabricated by the co-sputtered method are investigated. The transmittance and absorption show that AGZO is highly transparent across the visible light region, and the bandgap of AGZO can be tuned by varying the co-sputtering power. The AGZO TFT demonstrates high performance with a threshold voltage (VT) of 0.96 V, on/off current ratio of 1.01 × 107, and subthreshold swing (SS) of 0.33 V/dec. Besides, AGZO has potential for solar-blind applications because of its wide bandgap. The AGZO PTFT of this research can achieve a rejection ratio of 4.31 × 104 with proper sputtering power and a rising and falling time of 35.5 s and 51.5 s.
An Experimental Investigation into the Stress-Strain Characteristic under Static and Quasi-Static Loading for Partially Embedded Rock Bolts
Authors: Skrzypkowski Krzysztof
Published: March 2021

This article deals with a static and quasi-static load using the maximum power of a hydraulic pump. Additionally, quasi-static coefficients for the partially embedded rock bolts were determined. The laboratory tests included 2.2 m long bolts, which were embedded segmentally on the lengths of 0.05 m, 0.3 m and 0.9 m and were tested. To fix the ribbed bolt rods in the steel cylinders, resin cartridges with a length of 0.45 m long were used. The main aim of the research was to determine the load-displacement characteristics. Knowing the bolt rod tensile mechanism, the points of failure in the material continuity were identified, on the basis of which stress-strain characteristics are made. Particular attention was paid to the definition of: tensile stress for the yield point (σ1), maximum stress (σ2), stress at failure (σ3), strain in the elastic range (ε1), strain for maximum stress (ε2) and strain corresponding to the failure (ε3).
Photovoltaic Inverter Profiles in Relation to the European Network Code NC RfG and the Requirements of Polish Distribution System Operators
Authors: Chmielowiec Krzysztof , Topolski Łukasz , Piszczek Aleks , Hanzelka Zbigniew
Published: March 2021

The presently observed rapid increase in photovoltaic (PV) micro-installation connections to low-voltage networks, resulting from numerous financial support programmes, European Union (EU) energy policy and growing social awareness of environmental and economic issues, raise the question if PV inverters widely available in EU market fulfil the numerous technical requirements specified in European and Polish regulations. The paper presents the results of an experimental study carried out on three PV Inverters widely available in the EU in accordance with the EU network code NC RfG, standard EN 50549-1:2019 and internal Polish distribution system operators’ (DSOs’) regulations, governing PV inverter cooperation with the low-voltage distribution network. The laboratory test stand scheme and its description are presented. In each test, at least one of the inverters encountered issues, either with the operation in required frequency ranges (one PV inverter), activating reactive power control modes (all three PV inverters), maintaining required power generation gradient after tripping (one PV inverter) or under-voltage ride through immunity (one PV inverter). The obtained results have shown that all tested PV inverters did not meet requirements that are the key to maintaining reliable and safe operation of transmission and distribution electrical networks.
Testing Stability of Digital Filters Using Optimization Methods with Phase Analysis
Authors: Trofimowicz Damian , Stefański Tomasz P.
Published: March 2021

In this paper, novel methods for the evaluation of digital-filter stability are investigated. The methods are based on phase analysis of a complex function in the characteristic equation of a digital filter. It allows for evaluating stability when a characteristic equation is not based on a polynomial. The operation of these methods relies on sampling the unit circle on the complex plane and extracting the phase quadrant of a function value for each sample. By calculating function-phase quadrants, regions in the immediate vicinity of unstable roots (i.e., zeros), called candidate regions, are determined. In these regions, both real and imaginary parts of complex-function values change signs. Then, the candidate regions are explored. When the sizes of the candidate regions are reduced below an assumed accuracy, then filter instability is verified with the use of discrete Cauchy’s argument principle. Three different algorithms of the unit-circle sampling are benchmarked, i.e., global complex roots and poles finding (GRPF) algorithm, multimodal genetic algorithm with phase analysis (MGA-WPA), and multimodal particle swarm optimization with phase analysis (MPSO-WPA). The algorithms are compared in four benchmarks for integer- and fractional-order digital filters and systems. Each algorithm demonstrates slightly different properties. GRPF is very fast and efficient; however, it requires an initial number of nodes large enough to detect all the roots. MPSO-WPA prevents missing roots due to the usage of stochastic space exploration by subsequent swarms. MGA-WPA converges very effectively by generating a small number of individuals and by limiting the final population size. The conducted research leads to the conclusion that stochastic methods such as MGA-WPA and MPSO-WPA are more likely to detect system instability, especially when they are run multiple times. If the computing time is not vitally important for a user, MPSO-WPA is the right choice, because it significantly prevents missing roots.
Resistance Separation of Polymer Electrolyte Membrane Fuel Cell by Polarization Curve and Electrochemical Impedance Spectroscopy
Authors: Choi Jaehyeon , Sim Jaebong , Oh Hwanyeong , Min Kyoungdoug
Published: March 2021

The separation of resistances during their measurement is important because it helps to identify contributors in polymer electrolyte membrane (PEM) fuel cell performance. The major methodologies for separating the resistances are electrochemical impedance spectroscopy (EIS) and polarization curves. In addition, an equivalent circuit was selected for EIS analysis. Although the equivalent circuit of PEM fuel cells has been extensively studied, less attention has been paid to the separation of resistances, including protonic resistance in the cathode catalyst layer (CCL). In this study, polarization curve and EIS analyses were conducted to separate resistances considering the charge transfer resistance, mass transport resistance, high frequency resistance, and protonic resistance in the CCL. A general solution was mathematically derived using the recursion formula. Consequently, resistances were separated and analyzed with respect to variations in relative humidity in the entire current density region. In the case of ohmic resistance, high frequency resistance was almost constant in the main operating load range (0.038–0.050 Ω cm2), while protonic resistance in the CCL exhibited sensitivity (0.025–0.082 Ω cm2) owing to oxygen diffusion and water content.
Mathematical Analysis of Line Intersection and Shortest Distance Algorithms
Authors: Pradhan Sajina , Hwang Suk-seung , Lee Dongbin
Published: March 2021

The time of arrival (TOA) trilateration is one of the representative location detection technologies (LDT) that determines the true location of a mobile station (MS) using a unique intersection point of three circles based on three radii corresponding to distances between MS and base stations (BSs) and center coordinates of BSs. Since the distance between MS and BS is estimated by using the number of time delays, three circles based on the estimated radii are generally increased and they may not meet at a single point, resulting in the location estimation error. In order to compensate this estimation error and to improve estimation performance, we present two advanced TOA trilateration localization algorithms with detail mathematical expressions. The considered algorithms are the shortest distance algorithm, which calculates an average of three interior intersection points among an entire six intersection points from three intersecting circles, and the line intersection algorithm, which calculates an intersection point of three lines connecting two intersection points of two circles among the three circles, as the estimated location of the MS. In this paper, we present both algorithms with detailed mathematical expressions. The computer simulation results are provided to compare the location estimation performance of both algorithms. In addition, in this paper, mathematical analysis is provided to indicate the relation between the line intersection algorithm and the shortest distance algorithm. In this analysis, we verify that line equations based on the intersection points obtained from the shortest distance algorithm are identical to those obtained from the line intersection algorithm.
Solar Thermochemical Green Fuels Production: A Review of Biomass Pyro-Gasification, Solar Reactor Concepts and Modelling Methods
Authors: Abanades Stéphane , Rodat Sylvain , Boujjat Houssame
Published: March 2021

This paper addresses the solar thermochemical conversion of biomass or waste feedstocks based on pyro-gasification for the clean production of high-value and energy-intensive fuels. The utilization of solar energy for supplying the required process heat is attractive to lower the dependence of gasification processes on conventional energy resources and to reduce emissions of CO2 and other pollutants for the production of high-value chemical synthetic fuels (syngas). Using concentrated solar energy to drive the endothermal reactions further allows producing more syngas with a higher gas quality, since it has not been contaminated by combustion products, while saving biomass resources. The solar-driven process is thus a sustainable and promising alternative route, enabling syngas yield enhancement and CO2 mitigation, thereby potentially outperforming the performance of conventional processes for syngas production. This review presents relevant research studies in the field and provides the scientific/technical knowledge and background necessary to address the different aspects of the solar gasification process. An overview of the available solar concentrating technologies and their performance metrics is first introduced. The solar gasifier concepts and designs that were studied from lab to industrial scale are presented, along with their main benefits and limitations. The different management strategies proposed to deal with solar energy variations are also outlined, as well as the major pilot-scale applications and large-scale system level simulations. A specific emphasis is provided on the spouted bed technology that appears promising for the gasification process. Finally, the main modeling approaches of pyro-gasification and kinetics for simulation of gasifiers are described. This study thus provides a detailed overview of the efforts made to enhance the thermochemical performance of solar-assisted biomass gasification for synthetic fuel production.
Generalized Behavioral Modelling Methodology of Switch-Diode Cell for Power Loss Prediction in Electromagnetic Transient Simulation
Authors: Xu Yanming , Ho Carl Ngai Man , Ghosh Avishek , Muthumuni Dharshana
Published: March 2021

Modern wide-bandgap (WBG) devices, such as silicon carbide (SiC) or gallium nitride (GaN) based devices, have emerged and been increasingly used in power electronics (PE) applications due to their superior switching feature. The power losses of these devices become the key of system efficiency improvement, especially for high-frequency applications. In this paper, a generalized behavioral model of a switch-diode cell (SDC) is proposed for power loss estimation in the electromagnetic transient simulation. The proposed model is developed based on the circuit level switching process analysis, which considers the effects of parasitics, the operating temperature, and the interaction of diode and switch. In addition, the transient waveforms of the SDC are simulated by the proposed model using dependent voltage and current sources with passive components. Besides, the approaches of obtaining model parameters from the datasheets are given and the modelling method is applicable to various semiconductors such Si insulated-gate bipolar transistor (IGBT), Si/SiC metal–oxide–semiconductor field-effect transistor (MOSFET), and GaN devices. Further, a multi-dimensional power loss table in a wide range of operating conditions can be obtained with fast speed and reasonable accuracy. The proposed approach is implemented in PSCAD/ Electromagnetic Transients including DC, EMTDC, (v4.6, Winnipeg, MB, Canada) and further verified by the hardware setups including different daughter boards for different devices.
Investigation of the Churning Loss Reduction in 2D Motion-Converting Mechanisms
Authors: Ding Chuan , Huang Yu , Zhang Lichao , Ruan Jian
Published: March 2021

In recent years, two dimensional (2D) hydraulic components have significantly flourished. After a brief development introduction of the 2D pump and 2D flowmeter, it could be concluded that the churning loss, which is caused by the rotational motion of 2D motion-converting mechanisms, has an increasing effect on reducing energy losses. This paper first presents a new 2D motion-converting mechanism and introduces its structure and working principles. To compare it with the former 2D motion-converting mechanism, the same working conditions were applied when designing the new one. Afterward, the generated churning loss by the active parts of the mechanism, such as the new rotor, was well studied by establishing a simplified CFD simulation model and was also verified to have a smaller churning loss than that of the former mechanism. As another key simulation result, the influence of the axial motion of the new rotor was found to be negligible for the churning loss even when the rotational speed was high enough. A test rig was subsequently built up to prove the simulation by monitoring the torque at various rotational speeds. As a result, the churning losses that took place in the new 2D motion-converting mechanism were certainly reduced, and the potential reasons for that were analyzed, as shown in the conclusion section.
A Solution to Pressure Equation with Its Boundary Condition of Combining Tangential and Normal Pressure Relations
Authors: Xiao Hui , Liu Wei
Published: March 2021

Pressure is a physical quantity that is indispensable in the study of transport phenomena. Previous studies put forward a pressure constitutive law and constructed a partial differential equation on pressure to study the convection with or without heat and mass transfer. In this paper, a numerical algorithm was proposed to solve this pressure equation by coupling with the Navier-Stokes equation. To match the pressure equation, a method of dealing with pressure boundary condition was presented by combining the tangential and normal direction pressure relations, which should be updated dynamically in the iteration process. Then, a solution to this pressure equation was obtained to bridge the gap between the mathematical model and a practical numerical algorithm. Through numerical verification in a circular tube, it is found that the proposed boundary conditions are applicable. The results demonstrate that the present pressure equation well describes the transport characteristics of the fluid.
NMR-Based Study of the Pore Types’ Contribution to the Elastic Response of the Reservoir Rock
Authors: Golsanami Naser , Zhang Xuepeng , Yan Weichao , Yu Linjun , Dong Huaimin , Dong Xu , Cui Likai , Jayasuriya Madusanka Nirosh , Fernando Shanilka Gimhan , Barzgar Ehsan
Published: March 2021

Seismic data and nuclear magnetic resonance (NMR) data are two of the highly trustable kinds of information in hydrocarbon reservoir engineering. Reservoir fluids influence the elastic wave velocity and also determine the NMR response of the reservoir. The current study investigates different pore types, i.e., micro, meso, and macropores’ contribution to the elastic wave velocity using the laboratory NMR and elastic experiments on coal core samples under different fluid saturations. Once a meaningful relationship was observed in the lab, the idea was applied in the field scale and the NMR transverse relaxation time (T2) curves were synthesized artificially. This task was done by dividing the area under the T2 curve into eight porosity bins and estimating each bin’s value from the seismic attributes using neural networks (NN). Moreover, the functionality of two statistical ensembles, i.e., Bag and LSBoost, was investigated as an alternative tool to conventional estimation techniques of the petrophysical characteristics; and the results were compared with those from a deep learning network. Herein, NMR permeability was used as the estimation target and porosity was used as a benchmark to assess the reliability of the models. The final results indicated that by using the incremental porosity under the T2 curve, this curve could be synthesized using the seismic attributes. The results also proved the functionality of the selected statistical ensembles as reliable tools in the petrophysical characterization of the hydrocarbon reservoirs.
A Comparison of Partial Admission Axial and Radial Inflow Turbines for Underwater Vehicles
Authors: Wang Hanwei , Chao Yue , Tang Tian , Luo Kai , Qin Kan
Published: March 2021

The metal fueled steam Rankine cycle has been successfully applied to Unmanned Underwater Vehicles. However, the suitable turbine configuration is yet to be determined for this particular application. In this paper, the mean-line design approach based on the existing empirical correlations is first described. The corresponding partial admission axial and radial inflow turbines are then preliminarily designed. To assess the performance of designed turbines, the three-dimensional Computational Fluid Dynamics (CFD) simulations and steady-state structural analysis are performed. The results show that axial turbines are more compact than radial inflow turbines at the same output power. In addition, since radial inflow turbines can reduce the exit energy loss, this benefit substantially offsets the increment of the rotor losses created by the low speed ratios and supersonic rotor inlet velocity. On the contrary, due to the large volume of dead gas and strong transient effects caused by the high rotor blade length of radial inflow turbines, the overall performance between axial and radial inflow turbines is comparable (within 4%). However, the strength of radial inflow turbines is slightly superior because of lower blade inlet height and outlet hub radius. This paper confirms that the axial turbine is the optimal configuration for underwater vehicles in terms of size, aerodynamics and structural performance.
An Integrated Approach for the Valorization of Cheese Whey
Authors: Barba Francisco J.
Published: March 2021

Taking into account the large amount of whey that is produced during the cheese production process and the constant demand by society for more sustainable processes, in accordance with Sustainable Development Goals (SDGs) and the circular economy concept, it is necessary to adapt two-unit operations into a single process, allowing us to not only valorize a part of the whey but the whole process, which is known as bioprocess integration. In this sense, the adaptation of different processes, for example, physicochemical (micro, ultra and nanofiltration) and fermentation, that are commonly used to obtain proteins, lactose and other compounds with different activities (antioxidant, antifungal, etc.) could be integrated to achieve a complete recovery of the cheese whey. Likewise, keeping in mind that one of the main drawbacks of cheese whey is the great microbial load, some innovative processing technologies, such as high hydrostatic pressures, electrotechnologies and ultrasound, can allow both the development of new foods from whey as well as the improvement of the nutritional and organoleptic properties of the final products prepared with cheese, and thus reducing the microbial load and obtaining a safe product could be incorporated in the cheese whey valorization process.
Increases of Lipophilic Antioxidants and Anticancer Activity of Coix Seed Fermented by Monascus purpureus
Authors: Zeng Haiying , Qin Likang , Liu Xiaoyan , Miao Song
Published: March 2021

Lipophilic tocols, γ-oryzanol, and coixenolide in coix seed before and after fermentation by Monascus purpureus were determined. Antioxidant and anticancer activities of raw and fermented coix seed were evaluated using free-radical-scavenging assays and polyunsaturated fatty acid oxidation model, and human laryngeal carcinoma cell HEp2, respectively. Compared to the raw seed, the tocols, γ-oryzanol, and coixenolide contents increased approximately 4, 25, and 2 times, respectively, in the fermented coix seed. Especially, γ-tocotrienol and γ-oryzanol reached 72.5 and 655.0 μg/g in the fermented coix seed. The lipophilic extract from fermented coix seed exhibited higher antioxidant activity in scavenging free radicals and inhibiting lipid oxidation. The inhibitory concentrations for 50% cell survival (IC50) of lipophilic extract from fermented coix seed in inhibiting HEp2 cells decreased by 42%. This study showed that coix seed fermented by M. purpureus increased free and readily bioavailable lipophilic antioxidants and anticancer activity. Therefore, fermentation could enhance the efficacy of the health promoting function of coix seeds.
Trace Element Concentration and Stable Isotope Ratio Analysis in Blueberries and Bilberries: A Tool for Quality and Authenticity Control
Authors: Klavins Linards , Maaga Inessa , Bertins Maris , Hykkerud Anne Linn , Karppinen Katja , Bobinas Česlovas , Salo Heikki M. , Nguyen Nga , Salminen Henriikka , Stankevica Karina , Klavins Maris
Published: March 2021

Vaccinium genus berries—wild bilberries (Vaccinium myrtillus L.) and cultivated highbush blueberries (Vaccinium corymbosum L.)—are consumed worldwide, and their consumption has a trend of stable increase. Thus, considering their wide use in ethnomedicine, for juice and jam production, as functional food, as well as their use in preparations of extracts which have application potential in pharmaceutical and cosmetics industries, studies regarding the composition of these berries are of special importance. The aim of this study is to characterise the elemental and isotopic composition, as well as variation in element concentration in bilberries gathered from different sites in Northern Europe and in commercially available blueberry samples from across the World. Furthermore, our aim was to develop tools for authenticity and quality control of these berries. The elemental composition of berries was analysed using inductively coupled plasma with optical emission detection (ICP-OED), while isotope ratio mass spectrometry (IRMS) was used for the determination of isotope ratio values. The results demonstrated detectable differences between macro- and microelement values in bilberries. IRMS analysis of blueberries revealed significant differences in isotope ratios based on the place of origin, indicating the possibility to use this analytical method for authenticity testing. In none of the samples, pollution was detected, even though there were indications of different growth conditions and geochemical differences affecting bilberry composition.
Applications of Natural Antimicrobials in Food Packaging and Preservation
Authors: Rodrigo Dolores , Palop Alfredo
Published: March 2021

In the food science field, the term “antimicrobial” basically refers to active substances of synthetic or natural origin, that are directly or indirectly present in a specific food, packaging material or food contact surface that affect the viability or the growth of microorganisms in that matrix [...]
Is Green the New Red? Marxism, Ecology, and Contemporary Architectural Theory
Authors: Swope Curtis
Published: March 2021

This essay examines the role of Marxist concepts in recent architectural theories of ecology using two architecture firms, Estudio Teddy Cruz and Sauerbruch Hutton (SH), as case studies. In their writings, Cruz and SH mobilize the critique of capital, a dialectical materialist understanding of history, and the Frankfurt School’s critique of functionalist culture for the theorization of sustainable design. Their work has two vital ramifications for current sustainability discourses in two different fields which this essay seeks to bridge. For Marxist theorists concerned about ecology but averse to Western Marxism because of its supposed idealism, Cruz and SH show anew the importance of aesthetic concerns to conceptions of the environment. For design scholars accustomed to thinking of Marxism as having been absorbed into broader debates about cultural studies, the architects’ theories have the potential to recentralize the left-wing inheritance through its adaptation to concerns of ecology. In addition, in the essay’s conclusion, I reflect briefly, as a suggestion for further research, on how Cruz’s and SH’s architectural practice and theories might productively be analyzed in light of the terms of the Adorno-Benjamin debate of the 1930s over the political status of the cultural products of capital. Can eighty-year old discussions of the potentially revolutionary and retrograde qualities of mass cultural objects be relevant to radical thought in the age of climate change.
The Participation of Older People in the Concept and Design Phases of Housing in The Netherlands: A Theoretical Overview
Authors: van Hoof Joost , Rusinovic Katja M. , Tavy Zsuzsu. K. C. T. , van den Hoven Rudy F. M. , Dikken Jeroen , van der Pas Suzan , Kruize Hanneke , de Bruin Simone R. , van Bochove Marianne E.
Published: March 2021

In the Netherlands, there is a growing need for collective housing for older people to bridge the gap between ageing-in-place and institutional care facilities. Participation of older people in the concept and design phases is important to tune the market supply to the needs of (future) residents, yet social entrepreneurs find it challenging to involve older people. This commentary explores various ways older people can participate in the development of new housing initiatives. The ladder of citizen participation is applied to explore different roles that (future) residents could play with levels of influence varying from non-participation to citizen power. Considerations for meaningful participation are discussed, in order to show how collaborations can be formed between (future) residents and decision makers.
Depressive Symptoms among Patients with Diabetes in Qatar: Frequency and Potential Determinants
Authors: Bawadi Hiba , Al-Shahwani Alanood , Arafeh Dana , Al-Asmar Daniah , Moawad Joyce , Shi Zumin , Daher-Nashif Suhad
Published: March 2021

Background: Diabetes is a highly prevalent chronic disease that is associated with major complications. Findings regarding risk of depression among patients with diabetes are controversial. This study aimed to determine the prevalence and determinants of depressive symptoms among Qatari patients with type 2 diabetes. Methods: This cross-sectional study was based on Qatar Biobank (QBB) data of 2448 Qatari adults with diabetes aged 21–60 years old. Data regarding age, gender, education, income, body mass index (BMI), medication use, glycated hemoglobin (HbA1c) were retrieved. Patients’ responses to the Patient Health Questionnaire-9 (PHQ-9) were also obtained. Data analyses was performed using STATA 16, and statistical significance was considered at a p-value of <0.05. Results: Of the 2448 participants, 15.4% (n = 378) had self-reported depressive symptoms. Depressive symptoms were frequent among females (69.6%), smokers (15.9%), and participants with a higher level of education (47.1%). Average age of participants who reported depressive symptoms was significantly less that among participants without depressive symptoms (44.8 vs. 52.9 years). Qatari women with diabetes seem to be at higher risk of depression when compared to men (OR = 1.819, 95% CI: 1.42–2.33); The odds of reporting depressive symptoms were 35% higher among patients with more advanced educational qualifications (OR = 1.351, 95% CI: 1.00, 1.82). Smokers were twice as likely to report depressive symptoms as their non-smoking counterparts. There was no significant relationship between depression and poor glycemic control, physical activity, BMI, or insulin use. Conclusions: In summary, the study results suggest that several sociodemographic factors, such as age, gender, and level of education were associated with the risk of depressive symptoms among Qataris with diabetes.
Submaximal Elastic Resistance Band Tests to Estimate Upper and Lower Extremity Maximal Muscle Strength
Authors: Haraldsson Bjarki T. , Andersen Christoffer H. , Erhardsen Katrine T. , Zebis Mette K. , Micheletti Jéssica K. , Pastre Carlos M. , Andersen Lars L.
Published: March 2021

Muscle strength assessment is fundamental to track the progress of performance and prescribe correct exercise intensity. In field settings, simple tests are preferred. This study develops equations to estimate maximal muscle strength in upper- and lower-extremity muscles based on submaximal elastic resistance tests. Healthy adults (n = 26) performed a maximal test (1 RM) to validate the ability of the subsequent submaximal tests to determine maximal muscle strength, with elastic bands. Using a within-group repeated measures design, three submaximal tests of 40%, 60%, and 80% during (1) shoulder abduction, (2) shoulder external rotation, (3) hip adduction, and (4) prone knee flexion were performed. The association between number of repetitions and relative intensity was modeled with both 1st and 2nd order polynomials to determine the best predictive validity. For both upper-extremity tests, a strong linear association between repetitions and relative intensity was found (R2 = 0.97–1.00). By contrast, for the lower-extremity tests, the associations were fitted better with a 2nd order polynomial (R2 = 1.00). The results from the present study provide formulas for predicting maximal muscles strength based on submaximal resistance in four different muscles groups and show a muscle-group-specific association between repetitions and intensity.
Important Dependency-Associated Community Resources among Elderly Individuals with a Low Level of Social Support in China
Authors: Li Ying , Pan Yiyang , Chen Yuan , Cui Pingyu
Published: March 2021

Background: The prevalence of dependency personality disorder is high among elderly individuals with a low level of social support. The objective of this study was to explore the dependency associated with important community resources among elderly individuals with a low level of social support from the perspective of resource demand. Methods: The population-based cross-sectional study was conducted in 22 locations in China. A total of 950 participants aged ≥60 years were selected using a complex multistage sampling design. All the data were collected using questionnaires via face-to-face interviews. The dependency was assessed using the standardized Chinese version of the Minnesota Multiphasic Personality Inventory-II. Community resources were assessed using 43 items. Logistic regression analysis was used to evaluate the association between dependency and important community resources. Results: Bivariate analysis showed that the level of social support was negatively associated with levels of income (p < 0.001) and education (p = 0.008) and was positively associated with social communication and interactions (p < 0.001). The logistic regression analysis showed that the emergency call or survival monitoring system (ECSMS) was the most important community resource that was significantly associated with the levels of dependency; the odds ratio was 2.64 (95% CI, 1.07–3.91; p = 0.031) among elderly individuals with a low level of social support. Conclusions: The levels of dependency were most significantly associated with the ECSMS among elderly individuals with a low level of social support. Our results suggest that improving the ECSMS can be the main problem in the development of community resources.
Exploring Factors That Could Potentially Have Affected the First 1000 Days of Absent Learners in South Africa: A Qualitative Study
Authors: van Zyl Carien , van Wyk Carlien
Published: March 2021

Background: The first 1000 days of life—from conception to the second birthday of children —is widely recognized as the most crucial development phase, which could have long lasting effects on the health and well-being of children throughout their lives. Purpose: The purpose of this study was to qualitatively explore and describe factors that could potentially have affected the first 1000 days of absent learners in the Foundation Phase within the Paarl-East community in the Western Cape of South Africa. Methods: The data for this qualitative descriptive study were collected through semi-structured interviews with 18 biological mothers of absent learners in the Foundation Phase, who resided in Paarl East. The transcribed texts were analyzed by making use of a thematic data analysis. Results: The findings revealed six predominant themes that played a role during the first 1000 days of the lives of these absent learners. Conclusion: It was concluded from the findings in this study that factors, such as health and nutrition of both the mothers and their children, substance use/abuse during pregnancy, toxic stress, support received by the mothers and their children, attachment, attentive care, and stimulation and play, could have affected the first 1000 days of the absent learners in this study. Since this study did not aim to confirm a correlation between the first 1000 days and absenteeism, but solely to explore factors affecting the first 1000 days, conclusions regarding cause and effect was not possible.
Depression, Anxiety and Eating Disorder-Related Impairment: Moderators in Female Adolescents and Young Adults
Authors: Sander Johanna , Moessner Markus , Bauer Stephanie
Published: March 2021

Adolescents and young adults, particularly females, are highly vulnerable to the development of anxiety disorders, depression, and eating disorders. Comorbid anxiety disorder or depression in eating disorders are associated with greater symptom severity, poorer prognosis, and burden of illness. Nonetheless, studies on what affects the relationship between anxiety, depression, and eating disorders in female at-risk samples are scarce. Using hierarchical linear modeling, the present study examined potential moderators to explain between-person differences in the association between anxiety, depression, and eating disorder-related impairment within 12- to 25-year-old females (N = 320). High impairment in anxiety/depression was associated with more severe eating disorder symptoms. Older age as well as greater impairment in mood dysregulation, self-esteem, and perfectionism were linked to more severe eating disorder symptomatology. Whereas mood dysregulation, self-esteem, and perfectionism had no statistically significant moderating effects, younger age appeared to augment the association of anxiety/depression and eating disorder symptomatology. Preventive care in particular needs to consider age-related effects as eating disorder symptoms are associated more strongly with symptoms of anxiety and depression in early adolescence.
A Meta-Analytical Comparison of the Effects of Small-Sided Games vs. Running-Based High-Intensity Interval Training on Soccer Players’ Repeated-Sprint Ability
Authors: Clemente Filipe Manuel , Ramirez-Campillo Rodrigo , Afonso José , Sarmento Hugo , Rosemann Thomas , Knechtle Beat
Published: March 2021

This systematic review with a meta-analysis was conducted to compare the effects of small-sided games (SSGs)-based interventions with the effects of running-based high-intensity interval training (HIIT) interventions on soccer players’ repeated sprint ability (RSA). The data sources utilized were Web of Science, Scopus, SPORTDiscus, and PubMed. The study eligibility criteria were: (i) parallel studies (SSG-based programs vs. running-based HIIT) conducted in soccer players with no restrictions on age, sex, or competitive level; (ii) isolated intervention programs (i.e., only SSG vs. only running-based HIIT as individual forms) with no restrictions on duration; (iii) a pre–post outcome for RSA; (iv) original, full-text, peer-reviewed articles written in English. An electronic search yielded 513 articles, four of which were included in the present study. There was no significant difference between the effects of SSG-based and HIIT-based training interventions on RSA (effect size (ES) = 0.30; p = 0.181). The within-group analysis revealed no significant effect of SSG-based training interventions (ES = −0.23; p = 0.697) or HIIT-based training interventions (ES = 0.08; p = 0.899) on RSA. The meta-comparison revealed that neither SSGs nor HIIT-based interventions were effective in improving RSA in soccer players, and no differences were found between the two types of training. This suggests that complementary training may be performed to improve the effects of SSGs and HIIT. It also suggests that different forms of HIIT can be used because of the range of opportunities that such training affords.
Development of a Patient-Oriented Intervention to Support Patient-Provider Conversations about Unnecessary Lower Back Pain Imaging
Authors: Madani Larijani Maryam , Dumba Cindy , Thiessen Heather , Palen Angie , Carr Tracey , Vanstone Jason R. , Fourney Daryl R. , Hartness Collin , Parker Robert , Groot Gary
Published: March 2021

Background: despite the efforts of multiple stakeholders to promote appropriate care throughout the healthcare system, studies show that two out of three lower back pain (LBP) patients expect to receive imaging. We used the Choosing Wisely Canada patient-oriented framework, prioritizing patient engagement, to develop an intervention that addresses lower back pain imaging overuse. Methods: to develop this intervention, we collaborated with a multidisciplinary advisory team, including two patient partners with lower back pain, researchers, clinicians, healthcare administrators, and the Choosing Wisely Canada lead for Saskatchewan. For this qualitative study, data were collected through two advisory team meetings, two individual interviews with lower back pain patient partners, and three focus groups with lower back pain patient participants. A lower back pain prescription pad was developed as an outcome of these consultations. Results: participants reported a lack of interactive and informative communication was a significant barrier to receiving appropriate care. The most cited content information for inclusion in this intervention was treatments known to work, including physical activity, useful equipment, and reliable sources of educational material. Participants also suggested it was important that benefits and risks of imaging were explained on the pad. Three key themes derived from the data were also used to guide development of the intervention: (a) the role of imaging in LBP diagnosis; (b) the impact of the patient-physician relationship on LBP diagnosis and treatment; and (c) the lack of patient awareness of Choosing Wisely Canada and their recommendations. Conclusions: the lower back pain patient-developed prescription pad may help patients and clinicians engage in informed conversations and shared decision making that could support reduce unnecessary lower back pain imaging.
Extracellular Vesicles as Biomarkers Carriers in Bladder Cancer: Diagnosis, Surveillance, and Treatment
Authors: Georgantzoglou Natalia , Pergaris Alexandros , Masaoutis Christos , Theocharis Stamatios
Published: March 2021

Exosomes are extracellular vesicles, enriched in biomolecular cargo consisting of nucleic acids, proteins, and lipids, which take part in intercellular communication and play a crucial role in both physiologic functions and oncogenesis. Bladder cancer is the most common urinary malignancy and its incidence is steadily rising in developed countries. Despite the high five-year survival in patients diagnosed at early disease stage, survival substantially drops in patients with muscle-invasive or metastatic disease. Therefore, early detection of primary disease as well as recurrence is of paramount importance. The role that exosomal biomarkers could play in bladder cancer patient diagnosis and surveillance, as well as their potential therapeutic applications, has not been extensively studied in this malignancy. In the present review, we summarize all relevant data obtained so far from cell lines, animal models, and patient biofluids and tissues. Current literature suggests that urine is a rich source of extracellular vesicle-derived biomarkers, compared with blood and bladder tissue samples, with potential applications in bladder cancer management. Further studies improving sample collection procedures and optimizing purification and analytical methods should augment bladder cancer diagnostic, prognostic, and therapeutic input of extracellular vesicles biomarkers in the future.
The Addition of Transdermal Delivery of Neostigmine and Glycopyrrolate by Iontophoresis to Thrice Weekly Bowel Care in Persons with Spinal Cord Injury: A Pilot Study
Authors: Bauman William A. , Sabiev Anton , Shallwani Shahzad , Spungen Ann M. , Cirnigliaro Christopher M. , Korsten Mark A.
Published: March 2021

Persons with spinal cord injury (SCI) have neurogenic bowel disorders characterized by difficulty with evacuation (DWE), fecal incontinence, and discoordination of defecation. Six medically stable in-patients with SCI with a mean age of 57 ± 10 years (range: 39–66 years) and time since injury of 18 ± 17 years (range: 3–47 years) were investigated. Standard of care (SOC) for bowel care was followed by two weeks of SOC plus neostigmine (0.07 mg/kg) and glycopyrrolate (0.014 mg/kg) administered transcutaneously by iontophoresis thrice weekly for two weeks while patients continued to receive SOC. The primary endpoint was time to bowel evacuation. Body weights and abdominal radiographs were obtained. Ten questions related to bowel function and the Treatment Satisfaction Questionnaire for Medication were acquired after each arm. Bowel evacuation time decreased after the dual drug intervention arm (106.9 ± 68.4 vs. 40.8 ± 19.6 min; p < 0.0001). Body weight decreased (2.78 ± 0.98 kg; p < 0.0001), a finding confirmed on abdominal radiograph. Both questionnaires demonstrated improvement after the dual drug intervention arm. No major adverse events occurred. The addition of neostigmine and glycopyrrolate by transcutaneous administration to SOC for bowel care in persons with SCI and DWE resulted in the safe, effective, and predictable bowel evacuation with subjective improvement in bowel care.
Prognostic Markers for Chorioamnionitis: IL-6, TNF-α, and MMP-8 in Vaginally Obtained Amniotic Fluid
Authors: Balciuniene Greta , Gulbiniene Violeta , Dumalakiene Irena , Viliene Rita , Bartkeviciene Daiva , Pilypiene Ingrida , Drasutiene Grazina S. , Ramasauskaite Diana
Published: March 2021

Background. Earlier chorioamnionitis diagnosis is crucial to improve maternal and neonatal health outcomes. This study was conducted to evaluate the inlerleukin-6 (IL-6), tumor necrosis factor α (TNF-α), and matrix metalloproteinase 8 (MMP-8) levels in vaginally obtained amniotic fluid to investigate their prognostic value and to determine the most appropriate cut-off values for the prediction of chorioamnionitis. Methods. This case control study included women who were diagnosed with preterm premature rupture of the membranes before 34 weeks of gestation and were admitted to Vilnius University Hospital Santaros Klinikos. Free-leaking amniotic fluid was obtained vaginally with a sterile speculum less than 48h before delivery. Amniotic fluid IL-6, TNF-α, and MMP-8 levels were determined by the Enzyme Linked Immunosorbent Assay. Diagnosis of chorioamnionitis was confirmed by histological examination of the placenta and membranes after delivery. Results. The study included 156 women, 65 patients in the histological chorioamnionitis group (Group I) and 91 in a group without diagnosed histological chorioamnionitis (Group II). The median concentrations of IL-6, MMP-8, and TNF-α in amniotic fluid were statistically significantly higher in Group I than in Group II (p-value < 0.001). The area under the curve of TNF-α and MMP-8 were higher than the area under the curve of IL-6 (0.91, 0.89, and 0.81, respectively). No statistically significant difference was found when comparing the receiver operating characteristic (ROC) curves of TNF-α and MMP-8. The optimum cut-off values for the prediction of chorioamnionitis were found to be 1389.82 pg/mL for IL-6, 21.17 pg/mL for TNF-α, and 172.53 ng/mL for MMP-8. The sensitivity, specificity, positive prognostic value (PPV), and negative prognostic value (NPV) of the IL-6 cut-off for chorioamnionitis were 88%, 70%, 67%, and 89%, respectively. The sensitivity, specificity, PPV, and NPV of the TNF-α cut-off were 88%, 84%, 79%, and 90%, respectively. The sensitivity, specificity, PPV, and NPV of the MMP-8 cut-off were 80%, 87%, 81%, and 86%, respectively. Conclusions. The vaginally obtained amniotic fluid IL-6, MMP-8, and TNF-α seem to be good predictors for chorioamnionitis of patients with preterm premature rupture of membranes before 34 weeks of gestation. The noninvasive technique of sampling amniotic fluid could be alternative method to invasive amniocentesis.