bluuebunny/crossref_metadata_2025 huggingface dataset:
Políticas tributarias y acceso a créditos en el sector microempresarial, periodo 2014-2019
Authors: Delgado-Olaya Ruth Maryury , Zambrano-Morales Ángel Alberto , Guamarriga-Valdez Katherine del Cisne , Sánchez-Valle Paulina Esperanza
Published: January 2022

La presente investigación, tiene por finalidad analizar las políticas tributarias y de acceso a créditos que contribuyen al desarrollo de las microempresas en la provincia de El Oro, período 2014-2019. La metodología utilizada fue cuantitativa con un enfoque descriptivo-prospectiva. La recopilación de datos se realizó a través de una revisión bibliográfica de los beneficios económicos emitidas por las políticas tributarias con relación al RISE y Régimen de Microempresas en Ecuador; revisión  de las bases de datos de las páginas del Instituto Nacional de Estadísticas y Censos (INEC); la Asociación de Bancos Privados del Ecuador y el Servicio de Rentas Internas cuya información permitió un análisis comparativo entre el volumen de crédito otorgado en la provincia de El Oro y los microcréditos; asimismo, una proyección promedio de los montos concedidos a los microempresarios desde el 2016 al 2019; de igual manera se identifica la sección de mayor otorgamiento de microcréditos. Entre los hallazgos se evidenció en materia tributaria que el Régimen Impositivo Simplificado Ecuatoriano ha beneficiado a 26.912 pequeños negocios en el año 2018 pasando de la informalidad a la formalidad y la oportunidad de acceder a un crédito justificando sus ingresos. Por otra parte; la inversión en créditos concedidos por la banca privada y la SEPS; ha ido aumentando, con una excepción en el año 2019 que disminuyó. El nuevo régimen de microempresas y los altos porcentajes de interés establecidos para créditos al sector microempresarial, influyen en los flujos del disponible que se tornan indispensables para fortalecer la liquidez en las empresas, el capital de trabajo y el ingreso.
Quantification of Dust Emissions during Tillage Operations in Steep Slope Vineyards in the Moselle Area
Authors: Marzen Miriam , Porten Matthias , Ries Johannes B.
Published: January 2022

Measurements of dust emissions and the modeling of dissipation dynamics and total values are related to great uncertainties. Agricultural activity, especially soil cultivation, may be an essential component to calculate and model local and regional dust dynamics and even connect to the global dust cycle. To budget total dust and to assess the impact of tillage, measurement of mobilized and transported dust is an essential but rare basis. In this study, a simple measurement concept with Modified Wilson and Cook samplers was applied for dust measurements on a small temporal and spatial scale on steep-slope vineyards in the Moselle area. Without mechanical impact, a mean horizontal flux of 0.01 g m2 min−1 was measured, while row tillage produced a mean horizontal flux of 5.92 g m2 min−1 of mobilized material and 4.18 g m2 min−1 emitted dust from site (=soil loss). Compared on this singular-event basis, emissions during tillage operations generated 99.89% of total emitted dust from the site under low mean wind velocities. The results also indicate a differing impact of specific cultivation operations, mulching, and tillage tools as well as the additional influence of environmental conditions, with highest emissions on dry soil and with additional wind impact. The dust source function is strongly associated with cultivation operations, implying highly dynamic but also regular and thus predictable and projectable emission peaks of total suspended particles. Detailed knowledge of the effects of mechanical impulses and reliable quantification of the local dust emission inventory are a basis for analysis of risk potential and choice of adequate management options.
Evaluating the Fertilising Potential of Blended Recovered Nutrients in Horticultural Growing Medium on Viola x wittrockiana L.
Authors: Robles-Aguilar Ana A. , Grunert Oliver , Meers Erik , Jablonowski Nicolai D.
Published: January 2022

Viola x wittrockiana L. is an ornamental plant in high demand in horticulture. It is becoming more critical for greenhouse growers to focus on sustainable production to enhance plant quality while reducing negative environmental impacts. Therefore, assessing the effect of recycled phosphorous (P) and nitrogen (N) sources on the growth of viola could become very useful for producers in terms of sustainability. This experiment analysed the optimal fertiliser composition to grow viola using recovered fertilisers in a greenhouse trial under controlled conditions. Well-rooted viola plugs were grown in a standard peat-based growing medium. Using recycled sources of P and N as struvite and potassium struvite, ammonium sulphate, and ammonium nitrate, 14 fertiliser blends were prepared, tested, and compared with the slow-release commercial fertiliser Osmocote. Plants treated with ammonium nitrate showed healthy growth and optimal plant N concentrations. In contrast, most blends using the recovered ammonium sulphate resulted in an unacceptable increase of ammonium concentrations in the growing medium. The combination of ammonium sulphate and potassium sulphate caused an increase in the electrical conductivity in the growing medium, negatively affecting plant growth. However, blend 13 containing struvite, ammonium sulphate and potassium struvite expressed the best chemical composition with non-significant differences in the biomass from the positive controls, as it reduced the amount of potassium sulphate needed. Our results indicate that fertiliser blends containing P as struvite, N as ammonium nitrate or reduced amount of ammonium sulphate, and K as potassium struvite can substitute the use of mineral fertiliser blends to grow ornamental plant species as viola.
Validation of Rapid and Low-Cost Approach for the Delineation of Zone Management Based on Machine Learning Algorithms
Authors: Denora Michele , Fiorentini Marco , Zenobi Stefano , Deligios Paola A. , Orsini Roberto , Ledda Luigi , Perniola Michele
Published: January 2022

Proximal soil sensors are receiving strong attention from several disciplinary fields, and this has led to a rise in their availability in the market in the last two decades. The aim of this work was to validate agronomically a zone management delineation procedure from electromagnetic induction (EMI) maps applied to two different rainfed durum wheat fields. The k-means algorithm was applied based on the gap statistic index for the identification of the optimal number of management zones and their positions. Traditional statistical analysis was performed to detect significant differences in soil characteristics and crop response of each management zones. The procedure showed the presence of two management zones at both two sites under analysis, and it was agronomically validated by the significant difference in soil texture (+24.17%), bulk density (+6.46%), organic matter (+39.29%), organic carbon (+39.4%), total carbonates (+25.34%), total nitrogen (+30.14%), protein (+1.50%) and yield data (+1.07 t ha−1). Moreover, six unmanned aerial vehicle (UAV) flight missions were performed to investigate the relationship between five vegetation indexes and the EMI maps. The results suggest performing the multispectral images acquisition during the flowering phenological stages to attribute the crop spatial variability to different soil proprieties.
Assessment of the Working Performance of an Innovative Prototype to Harvest Hemp Seed in Two Different Conditions of Terrain Slope
Authors: Baraniecki Przemysław , Latterini Francesco , Stefanoni Walter , Frankowski Jakub , Wielgusz Katarzyna , Pari Luigi
Published: January 2022

After many decades when its cultivation was prohibited, hemp is regaining its position as one of the most versatile cultivated crops. Multiplication of monoecious hemp varieties requires manual male plants rouging to keep a high share of monoecious plants in the population. It forces relatively small multiplication fields usually oscillating around 5 ha, where the use of big harvesting machines is not economically feasible. The B-800 mower prototype for hemp panicles proved to be a good alternative to harvest seeds of tall fibrous hemp. The test results of the mower analyzed in this study show that although seed loss on a moderate slope (0.37%) was significantly higher than on a flat slope (0.13%), it was still much lower than in the case of harvesting hemp seed with a combined harvester. Moreover, the field efficiency of 93% is very satisfactory as it is reported for much bigger machines. Finally, the harvesting costs proved to be much lower than most of the machines used for harvesting hemp seed.
Sustainable Intensification of Beef Production in the Tropics: The Role of Genetically Improving Sexual Precocity of Heifers
Authors: Fernandes Júnior Gerardo Alves , Silva Delvan Alves , Mota Lucio Flavio Macedo , de Melo Thaise Pinto , Fonseca Larissa Fernanda Simielli , Silva Danielly Beraldo dos Santos , Carvalheiro Roberto , Albuquerque Lucia Galvão
Published: January 2022

Increasing productivity through continued animal genetic improvement is a crucial part of implementing sustainable livestock intensification programs. In Zebu cattle, the lack of sexual precocity is one of the main obstacles to improving beef production efficiency. Puberty-related traits are complex, but large-scale data sets from different “omics” have provided information on specific genes and biological processes with major effects on the expression of such traits, which can greatly increase animal genetic evaluation. In addition, genetic parameter estimates and genomic predictions involving sexual precocity indicator traits and productive, reproductive, and feed-efficiency related traits highlighted the feasibility and importance of direct selection for anticipating heifer reproductive life. Indeed, the case study of selection for sexual precocity in Nellore breeding programs presented here show that, in 12 years of selection for female early precocity and improved management practices, the phenotypic means of age at first calving showed a strong decreasing trend, changing from nearly 34 to less than 28 months, with a genetic trend of almost −2 days/year. In this period, the percentage of early pregnancy in the herds changed from around 10% to more than 60%, showing that the genetic improvement of heifer’s sexual precocity allows optimizing the productive cycle by reducing the number of unproductive animals in the herd. It has a direct impact on sustainability by better use of resources. Genomic selection breeding programs accounting for genotype by environment interaction represent promising tools for accelerating genetic progress for sexual precocity in tropical beef cattle.
Is Antibiotic Prophylaxis Necessary before Dental Implant Procedures in Patients with Orthopaedic Prostheses? A Systematic Review
Authors: Salgado-Peralvo Angel-Orión , Peña-Cardelles Juan-Francisco , Kewalramani Naresh , Garcia-Sanchez Alvaro , Mateos-Moreno María-Victoria , Velasco-Ortega Eugenio , Ortiz-García Iván , Jiménez-Guerra Álvaro , Végh Dániel , Pedrinaci Ignacio , Monsalve-Guil Loreto
Published: January 2022

As the population ages, more and more patients with orthopaedic prostheses (OPs) require dental implant treatment. Surveys of dentists and orthopaedic surgeons show that prophylactic antibiotics (PAs) are routinely prescribed with a very high frequency in patients with OPs who are about to undergo dental procedures. The present study aims to determine the need to prescribe prophylactic antibiotic therapy in patients with OPs treated with dental implants to promote their responsible use and reduce the risk of antimicrobial resistance. An electronic search of the MEDLINE database (via PubMed), Web of Science, LILACS, Google Scholar, and OpenGrey was carried out. The criteria used were those described by the PRISMA® Statement. No study investigated the need to prescribe PAs in patients with OPs, so four studies were included on the risk of infections of OPs after dental treatments with varying degrees of invasiveness. There is no evidence to suggest a relationship between dental implant surgeries and an increased risk of OP infection; therefore, PAs in these patients are not justified. However, the recommended doses of PAs in dental implant procedures in healthy patients are the same as those recommended to avoid infections of OPs.
Dietary Vitamin A Improved the Flesh Quality of Grass Carp (Ctenopharyngodon idella) in Relation to the Enhanced Antioxidant Capacity through Nrf2/Keap 1a Signaling Pathway
Authors: Wu Pei , Zhang Li , Jiang Weidan , Liu Yang , Jiang Jun , Kuang Shengyao , Li Shuwei , Tang Ling , Tang Wuneng , Zhou Xiaoqiu , Feng Lin
Published: January 2022

Fish is an important animal-source food for humans. However, the oxidative stress-induced by intensive aquaculture usually causes deterioration of fish meat quality. The nutritional way has been considered to be a useful method for improving fish flesh quality. This study using the same growth experiment as our previous study was conducted to investigate whether vitamin A could improve flesh quality by enhancing antioxidative ability via Nrf2/Keap1 signaling in fish muscle. Six diets with different levels of vitamin A were fed to grass carp (Ctenopharyngodon idella) (262.02 ± 0.45 g) for 10 weeks. Dietary vitamin A significantly improved flesh sensory appeal and nutritional value, as evident by higher pH24h value, water-holding capacity, shear force, contents of protein, lipid, four indispensable amino acids (lysine, methionine, threonine, and arginine) and total polyunsaturated fatty acid in the muscle. Furthermore, dietary vitamin A reduced oxidative damage, as evident by decreased levels of muscle reactive oxygen species, malondialdehyde, and protein carbonyl, enhanced activities of antioxidative enzyme (catalase, copper/zinc superoxide dismutase (CuZnSOD), MnSOD, glutathione peroxidase, and glutathione reductase), as well as increased content of glutathione, which was probably in relation to the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling. These findings demonstrated that dietary vitamin A improved flesh quality probably by enhancing antioxidant ability through Nrf2/Keap 1a signaling in fish.
Nrf2 in the Field of Dentistry with Special Attention to NLRP3
Authors: Schieffer Lisa , Manzl Claudia , Schatz Christoph , Haybaeck Johannes , Crismani Adriano
Published: January 2022

The aim of this review article was to summarize the functional implications of the nuclear factor E2-related factor or nuclear factor (erythroid-derived 2)-like 2 (Nrf2), with special attention to the NACHT (nucleotide-binding oligomerization), LRR (leucine-rich repeat), and PYD (pyrin domain) domains-containing protein 3 (NLRP3) inflammasome in the field of dentistry. NLRP3 plays a crucial role in the progression of inflammatory and adaptive immune responses throughout the body. It is already known that this inflammasome is a key regulator of several systemic diseases. The initiation and activation of NLRP3 starts with the oral microbiome and its association with the pathogenesis and progression of several oral diseases, including periodontitis, periapical periodontitis, and oral squamous cell carcinoma (OSCC). The possible role of the inflammasome in oral disease conditions may involve the aberrant regulation of various response mechanisms, not only in the mouth but in the whole body. Understanding the cellular and molecular biology of the NLRP3 inflammasome and its relationship to Nrf2 is necessary for the rationale when suggesting it as a potential therapeutic target for treatment and prevention of oral inflammatory and immunological disorders. In this review, we highlighted the current knowledge about NLRP3, its likely role in the pathogenesis of various inflammatory oral processes, and its crosstalk with Nrf2, which might offer future possibilities for disease prevention and targeted therapy in the field of dentistry and oral health.
Research on Key Factors of Sealing Performance of Combined Sealing Ring
Authors: Cheng Heming , Chen Xinyuan , Chen Xiaolan , Liu Hucheng
Published: January 2022

In this study, the mechanical properties of a combined seal ring under different loads were numerically calculated using ANSYS. The effect of the working pressure and pre-compression ratio of a rubber O-ring on the contact stress of the combined seal ring was studied. The influence of the wear ring’s chamfer, thickness, and width on the contact stress and contact force of the combined seal ring was analyzed. Studies have shown that it is particularly important to select a compression ratio that is suitable for the working conditions. Under the same conditions of working pressure and compression ratio, upon increasing the wear ring chamfer, the contact pressure is decreased due to the decreasing contact bandwidth between the wear ring and the cylinder wall. This has little effect on the contact stress of the combined seal ring as well as the contact force, while the width of the wear ring is proportional to the latter.
Object-Aware Adaptive Convolution Kernel Attention Mechanism in Siamese Network for Visual Tracking
Authors: Yuan Dongliang , Li Qingdang , Yang Xiaohui , Zhang Mingyue , Sun Zhen
Published: January 2022

As a classic framework for visual object tracking, the Siamese convolutional neural network has received widespread attention from the research community. This method uses a convolutional neural network to obtain the object features and to match them with the search area features to achieve object tracking. In this work, we observe that the contribution of each convolution kernel in the convolutional neural network for object tracking tasks is different. We propose an object-aware convolution kernel attention mechanism. Based on the characteristics of each object, the convolution kernel features are dynamically weighted to improve the expression ability of object features. The experiments performed using OTB and VOT benchmark datasets show that the performance of the tracking method fused with the convolution kernel attention mechanism is significantly better compared with the original method. Moreover, the attention mechanism can also be integrated with other tracking frameworks as an independent module to improve the performance.
Development of a Stock Price Prediction Framework for Intelligent Media and Technical Analysis
Authors: Mndawe Sibusiso T. , Paul Babu Sena , Doorsamy Wesley
Published: January 2022

Equity traders are always looking for tools that will help them maximise returns and minimise risk, be it fundamental or technical analysis techniques. This research integrates tools used by equity traders and uses them together with machine learning and deep learning techniques. The presented work introduces a South African-based sentiment classifier to extract sentiment from new headlines and tweets. The experimental work uses four machine learning models for fundamental analysis and six long short-term memory model architectures, including a developed encoder-decoder long short-term memory model for technical analysis. Data used in the experiments is mined and collected from news sites, tweets from Twitter and Yahoo Finance. The results from 2 experiments show an accuracy of 96% in predicting one of the major telecommunication companies listed on the JSE closing price movement while using the linear discriminant analysis model and an RMSE of 0.023 in predicting a significant telecommunication company closing price using encoder-decoder long short-term memory. These findings reveal that the sentiment feature contains an essential fundamental value, and technical indicators also help move closer to predicting the closing price.
Biomechanical Performance Analysis of the Monolateral External Fixation Devices with Steel and Composite Material Frames under the Impact of Axial Load
Authors: Pervan Nedim , Mešić Elmedin , Muminović Adis J. , Delić Muamer , Muratović Enis , Trobradović Mirsad , Hadžiabdić Vahidin
Published: January 2022

This paper describes comparative analysis of the biomechanical performances conducted on the external fixation devices whose frames are made out of two different material (stainless steel and composite material). Biomechanical properties were determined with experimental and FEM (finite element method) models which are used to study the movement of the fracture crack, establish stiffness of the design solutions and monitor generated stresses on the zones of interest. Geometric modeling of two fixation devices configurations B50 and C50 is used as a basis for structural analysis under the impact of axial load. Structural analysis results are confirmed with an experimental setup. Analyzed deflection values in the load and fracture zones are used to define the exact values of the stiffness for the construction design and fracture, respectively. The carbon frame device configuration has 28% lower construction stiffness than the one with the steel frame (for B50 configuration), i.e., 9% (for C50 configuration). In addition, fracture stiffness values for the composite frame application are approximately 23% lower (B50 configuration), i.e., 13% lower (C50 configuration), compared to steel frame. The carbon frame device has about 33% lower stresses at the critical zones compared to the steel frame at the control zone MM+ and, similarly, 35% lower stresses at the control zone MM-. With an exhausting analysis of the biomechanical properties of the fixation devices, it can be concluded that steel frame fixation device is superior, meaning it has better biomechanical characteristics compared to carbon frame fixation device, regarding obtained data for stresses and stiffnesses of the frame construction and fracture. Considering stresses at the critical zones of the fixation device construction, the carbon frame device has better biomechanical performances compared to steel frame devices.
Modular Robotic Design and Reconfiguring Path Planning
Authors: Dai Ye , Xiang Chao-Fang , Liu Zhao-Xu , Li Zhao-Long , Qu Wen-Yin , Zhang Qi-Hao
Published: January 2022

The modular robot is becoming a prevalent research object in robots because of its unique configuration advantages and performance characteristics. It is possible to form robot configurations with different functions by reconfiguring functional modules. This paper focuses on studying the modular robot’s configuration design and self-reconfiguration process and hopes to realize the industrial application of the modular self-reconfiguration robot to a certain extent. We design robotic configurations with different DOF based on the cellular module of the hexahedron and perform the kinematic analysis of the structure. An innovative design of a modular reconfiguration platform for conformational reorganization is presented, and the collaborative path planning between different modules in the reconfiguration platform is investigated. We propose an optimized ant colony algorithm for reconfiguration path planning and verify the superiority and rationality of this algorithm compared with the traditional ant colony algorithm for platform path planning through simulation experiments.
Regression Analysis of Rectal Cancer and Possible Application of Artificial Intelligence (AI) Utilization in Radiotherapy
Authors: Alnowami Majdi , Abolaban Fouad , Hijazi Hussam , Nisbet Andrew
Published: January 2022

Artificial Intelligence (AI) has been widely employed in the medical field in recent years in such areas as image segmentation, medical image registration, and computer-aided detection. This study explores one application of using AI in adaptive radiation therapy treatment planning by predicting the tumor volume reduction rate (TVRR). Cone beam computed tomography (CBCT) scans of twenty rectal cancer patients were collected to observe the change in tumor volume over the course of a standard five-week radiotherapy treatment. In addition to treatment volume, patient data including patient age, gender, weight, number of treatment fractions, and dose per fraction were also collected. Application of a stepwise regression model showed that age, dose per fraction and weight were the best predictors for tumor volume reduction rate.
Fabry-Perot Interferometer Based on Suspended Core Fiber for Detection of Gaseous Ethanol
Authors: Paixão Tiago , Nunes Ana Sofia , Bierlich Jörg , Kobelke Jens , Ferreira Marta S.
Published: January 2022

An optical fiber tip sensor based on a Fabry–Perot interferometer is proposed for the detection of ethanol in the gas phase. The sensor is fabricated by fusion splicing one end of the suspended core fiber to a single mode fiber, whereas the other end is kept open to enable the interaction between the light propagating in the suspended core and the ethanol gas molecules. The sensor was tested with different percentages of ethanol, exhibiting a linear response between 0 and 100 wt.%, with a sensitivity of 3.9 pm/wt.%. The proposed sensor, with a length of a few hundred micrometers, can be an alternative solution for the detection of gaseous ethanol in foods or beverages, such as wines and distilled drinks.
Usefulness of Digital Language Resources in Improving Native Language among Adults
Authors: Žilič Fišer Suzana , Pavlič Jani , Kožuh Ines
Published: January 2022

Important keys to effective communication are language competences, which can be supported by using digital language resources. These usually assist the acquisition of a second language, despite their potential for improving one’s native language. Our study was, thus, aimed at raising awareness about the possibilities of improving the native language of an adult population by using digital language resources for the Slovenian language. We conducted workshops, a survey and, partly, semi-structured interviews with 124 participants. We examined whether the perceived usefulness and ease of using digital language resources depends on age, education, self-assessed language proficiency, and experience with language training. The analysis revealed that self-initiative use of analogue language resources is related positively to using digital ones for seeking information, improving language use, as well as for study or work. Moreover, self-assessed proficiency in language was found to affect the perceived ease of using digital language resources. These findings may help language professionals support developing language skills by using digital language resources and preserving language in an adult population.
Assessment of the Feedstock Availability for Covering EU Alternative Fuels Demand
Authors: Prussi Matteo , Panoutsou Calliope , Chiaramonti David
Published: January 2022

Modern economies rely on the efficiency of their transportation sector; however, the environmental impact of the sector remains a growing concern. Among the various proposed solutions, the production and deployment of alternative fuels is a major option. However, concerns exist that the actual availability of sustainable feedstock might lower the current level of ambition. This paper addresses this issue by reviewing recent studies and policy targets, to match forecasts for expected demand and feedstock availability for road, aviation, and maritime sectors in the EU in 2030. The existing literature is fragmented and based on a variety of different approaches, and a consistent assessment of the potential overall demand for transport is still missing. In spite of the challenges posed by the numerous uncertainties, this research provides an estimate of potential European demand for alternative fuels that ranges between 20 and 33 Mtoe. We aimed to answer the question about the availability of sustainable feedstock to cover this potential demand. The analysis confirmed, even under very conservative assumptions, that feedstock may not be the major barrier today. Other issues, such as the feedstock costs, the price volatilities, the existing logistical infrastructures, etc., are relevant aspects contributing to the puzzle. Whilst feedstock is present across European regions, a critical element which requires detailed analysis at the implementation value chain level is the effectiveness of its sustainable mobilisation alongside the synergies and trade-offs that may arise.
IoT-Ready Temperature Probe for Smart Monitoring of Forest Roads
Authors: Gaspar Gabriel , Dudak Juraj , Behulova Maria , Stremy Maximilian , Budjac Roman , Sedivy Stefan , Tomas Boris
Published: January 2022

Currently, we are experiencing an ever-increasing demand for high-quality transportation in the distinctive natural environment of forest roads, which can be characterized by significant weather changes. The need for more effective management of the forest roads environment, a more direct, rapid response to fire interventions and, finally, the endeavor to expand recreational use of the woods in the growth of tourism are among the key factors. A thorough collection of diagnostic activities conducted on a regular basis, as well as a dataset of long-term monitored attributes of chosen sections, are the foundations of successful road infrastructure management. Our main contribution to this problem is the design of a probe for measuring the temperature profile for utilization in stand-alone systems or as a part of an IoT solution. We have addressed the design of the mechanical and electrical parts with emphasis on the accuracy of the sensor layout in the probe. Based on this design, we developed a simulation model, and compared the simulation results with the experimental results. An experimental installation was carried out which, based on measurements to date, confirmed the proposed probe meets the requirements of practice and will be deployed in a forest road environment.
Research on Real-Time Model of Turboshaft Engine with Surge Process
Authors: Zhang Xinglong , Li Lingwei , Zhang Tianhong
Published: January 2022

The main data source for the verification of surge detection methods still rely on test rigs of the compressor or the whole engine, which makes the development of models of the whole engine surge process an urgent need to replace the high-cost and high-risk surge test. In this paper, a novel real-time surge model based on the surge mechanism is proposed. Firstly, the turboshaft engine component level model (CLM) and the classic surge dynamic model, Moore-Greitzer (MG) model is established. Then the stability of the MG model is analyzed and the compressor characteristics in the classical MG model are extended to establish the extended MG model. Finally, this paper considers the coupling relationship of the compressor’s rotor speed, mass flow and pressure between CLM and the extended MG model to establish the real-time model of the turboshaft engine with surge process. The simulation results show that this model can realize the whole surge process of the turboshaft engine under multiple operating states. The change characteristics of the rotor speed, compressor outlet pressure, mass flow, exhaust gas temperature and other parameters are consistent with the test data, which means that the model proposed can be further applied to the research of surge detection and anti-surge control.
Dynamic Characteristics Analysis of a Rigid Body System with Spatial Multi-Point Supports
Authors: Zhu Qingyu , Han Qingkai , Yang Xiaodong , Lin Junzhe
Published: January 2022

This paper presents the dynamic characteristics analysis of a rigid body system with spatial multi-point elastic supports, as well as the sensitivity analysis of support parameters. A rigid object is characterized by six degrees-of-freedom (DOFs) motions and considering the spatial location vector decomposition of elastic supports, a rigid body system dynamic model with spatial multi-point elastic supports is derived via the Lagrangian energy method. The system modal frequencies are calculated, and to be verified by finite element modal analysis results. Next, based on the above-mentioned model, system modal frequencies are obtained under different support locations, where the support stiffness components are different. Interpolate the stiffness components corresponding to each support location, calculate system modal frequencies, and the response surface model (RSM) for system modal frequencies is established. Further, based on the RSM modal analysis results, the allowable support location for the system modal insensitive area can be obtained. At last, a lubricating oil-tank system with four supports is taken as an example, and the effects of support spatial locations and stiffness components on the system inherent characteristics are discussed. This present work can provide a basis for the dynamic design of the spatial location and stiffness for this type of installation structures.
Uncertainty Analysis and Experimental Validation of Identifying the Governing Equation of an Oscillator Using Sparse Regression
Authors: Ren Yaxiong , Adams Christian , Melz Tobias
Published: January 2022

In recent years, the rapid growth of computing technology has enabled identifying mathematical models for vibration systems using measurement data instead of domain knowledge. Within this category, the method Sparse Identification of Nonlinear Dynamical Systems (SINDy) shows potential for interpretable identification. Therefore, in this work, a procedure of system identification based on the SINDy framework is developed and validated on a single-mass oscillator. To estimate the parameters in the SINDy model, two sparse regression methods are discussed. Compared with the Least Squares method with Sequential Threshold (LSST), which is the original estimation method from SINDy, the Least Squares method Post-LASSO (LSPL) shows better performance in numerical Monte Carlo Simulations (MCSs) of a single-mass oscillator in terms of sparseness, convergence, identified eigenfrequency, and coefficient of determination. Furthermore, the developed method SINDy-LSPL was successfully implemented with real measurement data of a single-mass oscillator with known theoretical parameters. The identified parameters using a sweep signal as excitation are more consistent and accurate than those identified using impulse excitation. In both cases, there exists a dependency of the identified parameter on the excitation amplitude that should be investigated in further research.
Ultrasonic Inspection for Welds with Irregular Curvature Geometry Using Flexible Phased Array Probes and Semi-Auto Scanners: A Feasibility Study
Authors: Lim Seong Jin , Kim Young Lae , Cho Sungjong , Park Ik Keun
Published: January 2022

Pipes of various shapes constitute pipelines utilized in industrial sites. These pipes are coupled through welding, wherein complex curvatures such as a flange, an elbow, a reducer, and a branch pipe are often found. Using phased array ultrasonic testing (PAUT) to inspect weld zones with complex curvatures is faced with different challenges due to parts that are difficult to contact with probes, small-diameter pipes, spatial limitations due to adjacent pipes, nozzles, and sloped shapes. In this study, we developed a flexible PAUT probe (FPAPr) and a semi-automatic scanner that was improved to enable stable FPAPr scanning for securing its inspection data consistency and reproducibility. A mock-up test specimen was created for a flange, an elbow, a reducer, and a branch pipe. Artificial flaws were inserted into the specimen through notch and hole processing, and simulations and verification experiments were performed to verify the performance and field applicability of the FPAPr and semi-automatic scanner.
PCA-Based Identification of Built Environment Factors Reducing PM2.5 Pollution in Neighborhoods of Five Chinese Megacities
Authors: Chen Ming , Dai Fei
Published: January 2022

Air pollution, especially PM2.5 pollution, still seriously endangers the health of urban residents in China. The built environment is an important factor affecting PM2.5; however, the key factors remain unclear. Based on 37 neighborhoods located in five Chinese megacities, three relative indicators (the range, duration, and rate of change in PM2.5 concentration) at four pollution levels were calculated as dependent variables to exclude the background levels of PM2.5 in different cities. Nineteen built environment factors extracted from green space and gray space and three meteorological factors were used as independent variables. Principal component analysis was adopted to reveal the relationship between built environment factors, meteorological factors, and PM2.5. Accordingly, 24 models were built using 32 training neighborhood samples. The results showed that the adj_R2 of most models was between 0.6 and 0.8, and the highest adj_R2 was 0.813. Four principal factors were the most important factors that significantly affected the growth and reduction of PM2.5, reflecting the differences in green and gray spaces, building height and its differences, relative humidity, openness, and other characteristics of the neighborhood. Furthermore, the relative error was used to test the error of the predicted values of five verification neighborhood samples, finding that these models had a high fitting degree and can better predict the growth and reduction of PM2.5 based on these built environment factors.
Small-Sized Nanophosphorus Has a Positive Impact on the Performance of Fenugreek Plants under Soil-Water Deficit Stress: A Case Study under Field Conditions
Authors: Abou-Sreea Alaa I. B. , Kamal Marwa , El Sowfy Dalia M. , Rady Mostafa M. , Mohamed Gamal F. , Al-Dhumri Sami A. , AL-Harbi Mohammad S. , Abdou Nasr M.
Published: January 2022

Phosphorus (P) is an essential macronutrient necessary for plant growth, development, and reproduction. Two field experiments were carried out in 2018/2019 and 2019/2020 on P-deficient soil to evaluate the impact of foliar fertilization with nanophosphorus (nP) on growth, yield, and physio-biochemical indices, as well as trigonelline content of fenugreek plants under deficient irrigation (dI) stress (a deficit of 20 and 40% of crop evapotranspiration; dI-20 and dI-40). The growth and yield traits, leaf integrity (relative water content and membrane stability index), photosynthetic pigment contents, leaf and seed P contents, and stem and leaf anatomical features significantly decreased under dI-20, with greater reductions recorded under dI-40. In contrast, water-use efficiency, osmoprotective compounds, including free amino acids, soluble sugars, proline, and trigonelline, along with antioxidant contents (ascorbate, glutathione, phenolics, and flavonoids) and their activity increased significantly under both dI-20 and dI-40. However, foliar feeding with nano-P considerably increased plant growth and yield traits, leaf integrity, photosynthetic pigments contents, leaf and seed P contents, and anatomical features. Besides, water-use efficiency, osmoprotectant contents, and antioxidant content and activity were further increased under both dI-20 and dI-40. The positive effects were more pronounced with the smaller nP (25 nm) than the larger nP (50 nm). The results of this study backed up the idea of using foliar nourishment with nP, which can be effective in modulating fenugreek plant growth and seed production.
Implantable Cardioverter Defibrillator Multisensor Monitoring during Home Confinement Caused by the COVID-19 Pandemic
Authors: Ziacchi Matteo , Calò Leonardo , D’Onofrio Antonio , Manzo Michele , Dello Russo Antonio , Santini Luca , Giubilato Giovanna , Carriere Cosimo , Santobuono Vincenzo Ezio , Savarese Gianluca , La Greca Carmelo , Arena Giuseppe , Talarico Antonello , Pisanò Ennio , Giammaria Massimo , Pangallo Antonio , Campari Monica , Valsecchi Sergio , Diemberger Igor
Published: January 2022

Aims: The utilization of remote monitoring platforms was recommended amidst the COVID-19 pandemic. The HeartLogic index combines multiple implantable cardioverter defibrillator (ICD) sensors and has proved to be a predictor of impending heart failure (HF) decompensation. We examined how multiple ICD sensors behave in the periods of anticipated restrictions pertaining to physical activity. Methods: The HeartLogic feature was active in 349 ICD and cardiac resynchronization therapy ICD patients at 20 Italian centers. The period from 1 January to 19 July 2020, was divided into three phases: pre-lockdown (weeks 1–11), lockdown (weeks 12–20), post-lockdown (weeks 21–29). Results: Immediately after the implementation of stay-at-home orders (week 12), we observed a significant drop in median activity level whereas there was no difference in the other contributing parameters. The median composite HeartLogic index increased at the end of the Lockdown. The weekly rate of alerts was significantly higher during the lockdown (1.56 alerts/week/100 pts, 95%CI: 1.15–2.06; IRR = 1.71, p = 0.014) and post-lockdown (1.37 alerts/week/100 pts, 95%CI: 0.99–1.84; IRR = 1.50, p = 0.072) than that reported in pre-lockdown (0.91 alerts/week/100 pts, 95%CI: 0.64–1.27). However, the median duration of alert state and the maximum index value did not change among phases, as well as the proportion of alerts followed by clinical actions at the centers and the proportion of alerts fully managed remotely. Conclusions: During the lockdown, the system detected a significant drop in the median activity level and generated a higher rate of alerts suggestive of worsening of the HF status.
Comparison of Antiplatelet Effects of Phenol Derivatives in Humans
Authors: Hrubša Marcel , Alva Raúl , Parvin Mst Shamima , Macáková Kateřina , Karlíčková Jana , Fadraersada Jaka , Konečný Lukáš , Moravcová Monika , Carazo Alejandro , Mladěnka Přemysl
Published: January 2022

Flavonoids are associated with positive cardiovascular effects. However, due to their low bioavailability, metabolites are likely responsible for these properties. Recently, one of these metabolites, 4-methylcatechol, was described to be a very potent antiplatelet compound. This study aimed to compare its activity with its 22 close derivatives both of natural or synthetic origin in order to elucidate a potential structure–antiplatelet activity relationship. Blood from human volunteers was induced to aggregate by arachidonic acid (AA), collagen or thrombin, and plasma coagulation was also studied. Potential toxicity was tested on human erythrocytes as well as on a cancer cell line. Our results indicated that 17 out of the 22 compounds were very active at a concentration of 40 μM and, importantly, seven of them had an IC50 on AA-triggered aggregation below 3 μM. The effects of the most active compounds were confirmed on collagen-triggered aggregation too. None of the tested compounds was toxic toward erythrocytes at 50 μM and four compounds partly inhibited proliferation of breast cancer cell line at 100 μM but not at 10 μM. Additionally, none of the compounds had a significant effect on blood coagulation or thrombin-triggered aggregation. This study hence reports four phenol derivatives (4-ethylcatechol, 4-fluorocatechol, 2-methoxy-4-ethylphenol and 3-methylcatechol) suitable for future in vivo testing.
Plasmalemmal V-ATPase as a Potential Biomarker for Lactoferrin-Based Anticancer Therapy
Authors: Santos-Pereira Cátia , Rodrigues Lígia R. , Côrte-Real Manuela
Published: January 2022

Lactoferrin (Lf) is a milk-derived protein with well-recognized potential as a therapeutic agent against a wide variety of cancers. This natural protein exhibits health-promoting effects and has several interesting features, including its selectivity towards cancer cells, good tolerability in humans, worldwide availability, and holding a generally recognized as safe (GRAS) status. To prompt the rational clinical application of this promising anticancer compound, previous works aimed to unveil the molecular mechanisms underlying its selective anticancer activity, where plasmalemmal V-ATPase was identified as an Lf target in cancer cells. V-ATPase is a proton pump critical for cellular homeostasis that migrates to the plasma membrane of highly metastatic cancer cells contributing to the acidity of the tumor microenvironment. Cancer cells were found to be susceptible to Lf only when this proton pump is present at the plasma membrane. Plasmalemmal V-ATPase can thus be an excellent biomarker for driving treatment decisions and forecasting clinical outcomes of Lf-based anticancer strategies. Future research endeavors should thus seek to validate this biomarker by thorough preclinical and clinical studies, as well as to develop effective methods for its detection under clinical settings.
Disposable Stainless-Steel Wire-Based Electrochemical Microsensor for In Vivo Continuous Monitoring of Hydrogen Peroxide in Vein of Tomato Leaf
Authors: Huo Doudou , Li Daodong , Xu Songzhi , Tang Yujie , Xie Xueqian , Li Dayong , Song Fengming , Zhang Yali , Li Aixue , Sun Lijun
Published: January 2022

As one of the pivotal signal molecules, hydrogen peroxide (H2O2) has been demonstrated to play important roles in many physiological processes of plants. Continuous monitoring of H2O2 in vivo could help understand its regulation mechanism more clearly. In this study, a disposable electrochemical microsensor for H2O2 was developed. This microsensor consists of three parts: low-cost stainless-steel wire with a diameter of 0.1 mm modified by gold nanoparticles (disposable working electrode), an untreated platinum wire with a diameter of 0.1 mm (counter electrode), and an Ag/AgCl wire with a diameter of 0.1 mm (reference electrode), respectively. The microsensor could detect H2O2 in levels from 10 to 1000 µM and exhibited excellent selectivity. On this basis, the dynamic change in H2O2 in the vein of tomato leaf under high salinity was continuously monitored in vivo. The results showed that the production of H2O2 could be induced by high salinity within two hours. This study suggests that the disposable electrochemical microsensor not only suits continuously detecting H2O2 in microscopic plant tissue in vivo but also reduces the damage to plants. Overall, our strategy will help to pave the foundation for further investigation of the generation, transportation, and elimination mechanism of H2O2 in plants.
The Effects of Intraoperative Hypothermia on Postoperative Cognitive Function in the Rat Hippocampus and Its Possible Mechanisms
Authors: Xu Guangyan , Li Tianjia , Huang Yuguang
Published: January 2022

Intraoperative hypothermia is a common complication during operations and is associated with several adverse events. Postoperative cognitive dysfunction (POCD) and its adverse consequences have drawn increasing attention in recent years. There are currently no relevant studies investigating the correlation between intraoperative hypothermia and POCD. The aim of this study was to assess the effects of intraoperative hypothermia on postoperative cognitive function in rats undergoing exploratory laparotomies and to investigate the possible related mechanisms. We used the Y-maze and Morris Water Maze (MWM) tests to assess the rats’ postoperative spatial working memory, spatial learning, and memory. The morphological changes in hippocampal neurons were examined by haematoxylin-eosin (HE) staining and hippocampal synaptic plasticity-related protein expression. Activity-regulated cytoskeletal-associated protein (Arc), cyclic adenosine monophosphate-response element-binding protein (CREB), S133-phosphorylated CREB (p-CREB [S133]), α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor 1 (AMPAR1), and S831-phosphorylated AMPAR1 (p-AMPAR1 [S831]) were evaluated by Western blotting. Our results suggest a correlation between intraoperative hypothermia and POCD in rats and that intraoperative hypothermia may lead to POCD regarding impairments in spatial working memory, spatial learning, and memory. POCD induced by intraoperative hypothermia might be due to hippocampal neurons damage and decreased expression of synaptic plasticity-related proteins Arc, p-CREB (S133), and p-AMPAR1 (S831).