bluuebunny/crossref_metadata_2025 huggingface dataset:
Therapeutic Ophthalmic Lenses: A Review
Authors: Toffoletto Nadia , Saramago Benilde , Serro Ana Paula
Published: December 2020

An increasing incidence of eye diseases has been registered in the last decades in developed countries due to the ageing of population, changes in lifestyle, environmental factors, and the presence of concomitant medical conditions. The increase of public awareness on ocular conditions leads to an early diagnosis and treatment, as well as an increased demand for more effective and minimally invasive solutions for the treatment of both the anterior and posterior segments of the eye. Despite being the most common route of ophthalmic drug administration, eye drops are associated with compliance issues, drug wastage by lacrimation, and low bioavailability due to the ocular barriers. In order to overcome these problems, the design of drug-eluting ophthalmic lenses constitutes a non-invasive and patient-friendly approach for the sustained drug delivery to the eye. Several examples of therapeutic contact lenses and intraocular lenses have been developed, by means of different strategies of drug loading, leading to promising results. This review aims to report the recent advances in the development of therapeutic ophthalmic lenses for the treatment and/or prophylaxis of eye pathologies (i.e., glaucoma, cataract, corneal diseases, or posterior segment diseases) and it gives an overview of the future perspectives and challenges in the field.
ApoE-Targeting Increases the Transfer of Solid Lipid Nanoparticles with Donepezil Cargo across a Culture Model of the Blood–Brain Barrier
Authors: Topal Gizem Rüya , Mészáros Mária , Porkoláb Gergő , Szecskó Anikó , Polgár Tamás Ferenc , Siklós László , Deli Mária A. , Veszelka Szilvia , Bozkir Asuman
Published: December 2020

Pharmacological treatment of central nervous system (CNS) disorders is difficult, because the blood–brain barrier (BBB) restricts the penetration of many drugs into the brain. To solve this unmet therapeutic need, nanosized drug carriers are the focus of research efforts to develop drug delivery systems for the CNS. For the successful delivery of nanoparticles (NPs) to the brain, targeting ligands on their surface is necessary. Our research aim was to design a nanoscale drug delivery system for a more efficient transfer of donepezil, an anticholinergic drug in the therapy of Alzheimer’s disease across the BBB. Rhodamine B-labeled solid lipid nanoparticles with donepezil cargo were prepared and targeted with apolipoprotein E (ApoE), a ligand of BBB receptors. Nanoparticles were characterized by measurement of size, polydispersity index, zeta potential, thermal analysis, Fourier-transform infrared spectroscopy, in vitro release, and stability. Cytotoxicity of nanoparticles were investigated by metabolic assay and impedance-based cell analysis. ApoE-targeting increased the uptake of lipid nanoparticles in cultured brain endothelial cells and neurons. Furthermore, the permeability of ApoE-targeted nanoparticles across a co-culture model of the BBB was also elevated. Our data indicate that ApoE, which binds BBB receptors, can potentially be exploited for successful CNS targeting of solid lipid nanoparticles.
Role of Silicon in Mediating Phosphorus Imbalance in Plants
Authors: Hu An Yong , Xu Shu Nan , Qin Dong Ni , Li Wen , Zhao Xue Qiang
Published: December 2020

The soil bioavailability of phosphorus (P) is often low because of its poor solubility, strong sorption and slow diffusion in most soils; however, stress due to excess soil P can occur in greenhouse production systems subjected to high levels of P fertilizer. Silicon (Si) is a beneficial element that can alleviate multiple biotic and abiotic stresses. Although numerous studies have investigated the effects of Si on P nutrition, a comprehensive review has not been published. Accordingly, here we review: (1) the Si uptake, transport and accumulation in various plant species; (2) the roles of phosphate transporters in P acquisition, mobilization, re-utilization and homeostasis; (3) the beneficial role of Si in improving P nutrition under P deficiency; and (4) the regulatory function of Si in decreasing P uptake under excess P. The results of the reviewed studies suggest the important role of Si in mediating P imbalance in plants. We also present a schematic model to explain underlying mechanisms responsible for the beneficial impact of Si on plant adaption to P-imbalance stress. Finally, we highlight the importance of future investigations aimed at revealing the role of Si in regulating P imbalance in plants, both at deeper molecular and broader field levels.
Metabolic Engineering of Isoflavonoid Biosynthesis by Expressing Glycine max Isoflavone Synthase in Allium cepa L. for Genistein Production
Authors: Malla Ashwini , Shanmugaraj Balamurugan , Srinivasan Balamurugan , Sharma Ashutosh , Ramalingam Sathishkumar
Published: December 2020

Isoflavonoids, the diverse group of secondary metabolites derived from the phenylpropanoid pathway, are distributed predominantly in leguminous plants and play a vital role in promoting human health. Genetic engineering of the metabolite synthesis pathway has turned out to be an attractive approach for the production of various secondary metabolites. In our study, we attempted to produce the isoflavone genistein, a well-known health-promoting metabolite, in Allium cepa L. (onion) by introducing Glycine max Isoflavone synthase (GmIFS). The GmIFS gene was cloned into the pEarleyGate 102 HA vector and transformed into onion by Agrobacterium-mediated and biolistic methods. The presence of GmIFS in transgenic onion was confirmed by PCR, dot blot, and Southern hybridization. Analysis of the transgenic onion calli lines demonstrated that the expression of the GmIFS gene led to the production of isoflavone genistein in in vitro tissues. The biolistic stable transformed calli with transformation efficiency of 73% (62.65 nM/g FW) accumulated more genistein than the Agrobacterium stable transformed calli with transformation efficiency of 56% (42.5 nM/g FW). Overall, heterologous gene expression of GmIFS was demonstrated by modifying the secondary metabolite pathway in onion tissues for the production of isoflavone genistein that can boost up human health with its health-promoting properties.
Population Structure and Genetic Diversity of Cucurbita moschata Based on Genome-Wide High-Quality SNPs
Authors: Lee Hea-Young , Jang Siyoung , Yu Chea-Rin , Kang Byoung-Cheorl , Chin Joong-Hyoun , Song Kihwan
Published: December 2020

Pumpkins (Cucurbita moschata) are one of the most important economic crops in genus Cucurbita worldwide. They are a popular food resource and an important rootstock resource for various Cucurbitaceae. Especially, C. moschata is widely used as a rootstock for the commercial production of bloomless cucumbers in East Asia. Since the genetic diversity of the commercial rootstock varieties is narrow, there has been an increasing demand for the trait development of abiotic and biotic stress tolerance breeding. In this study, 2071 high-quality SNPs that were distributed evenly across 20 chromosomes of pumpkins were discovered through the genotyping-by-sequencing (GBS) analysis of 610 accessions of C. moschata germplasm with a global origin. Using these SNPs, various analyses of the genetic diversity and the population structure were performed. Three subgroups were clustered from the germplasm collection, which included East Asia, Africa, and America, and these areas were included the most in each subgroup. Among those groups, accessions from Africa and South Asia showed the highest genetic diversity, which was followed by the Mexico accessions. This result reflected that large gene pools that consist of various native landraces have been conserved in those of countries. Based on the genetic diversity, we finally constructed the C. moschata core collection, which included 67 representative accessions from the 610 germplasms. Five morphological traits that are important in commercial grafting and rootstock seed production, which include the cotyledon length, the cotyledon width, the hypocotyl length, the internode length, and the number of female flowers, were investigated for three years and used to confirm the validity of the core collection selection. The results are expected to provide valuable information about the genetic structure of the worldwide C. moschata germplasm and help to create new gene pools to develop genetically diverse rootstock breeding materials.
Encapsulation of the Natural Product Tyrosol in Carbohydrate Nanosystems and Study of Their Binding with ctDNA
Authors: Pontillo Antonella Rozaria Nefeli , Konstanteli Evangelia , Bairaktari Maria M. , Detsi Anastasia
Published: December 2020

Tyrosol, a natural product present in olive oil and white wine, possesses a wide range of bioactivity. The aim of this study was to optimize the preparation of nanosystems encapsulating tyrosol in carbohydrate matrices and the investigation of their ability to bind with DNA. The first encapsulation matrix of choice was chitosan using the ionic gelation method. The second matrix was β-cyclodextrin (βCD) using the kneading method. Coating of the tyrosol-βCD ICs with chitosan resulted in a third nanosystem with very interesting properties. Optimal preparation parameters of each nanosystem were obtained through two three-factor, three-level Box-Behnken experimental designs and statistical analysis of the results. Thereafter, the nanoparticles were evaluated for their physical and thermal characteristics using several techniques (DLS, NMR, FT-IR, DSC, TGA). The study was completed with the investigation of the impact of the encapsulation on the ability of tyrosol to bind to calf thymus DNA. The results revealed that tyrosol and all the studied systems bind to the minor groove of ctDNA. Tyrosol interacts with ctDNA via hydrogen bond formation, as predicted via molecular modeling studies and corroborated by the experiments. The tyrosol-chitosan nanosystem does not show any binding to ctDNA whereas the βCD inclusion complex shows analogous interaction with that of free tyrosol.
Modulation of Macrophages M1/M2 Polarization Using Carbohydrate-Functionalized Polymeric Nanoparticles
Authors: Andrade Raquel G. D. , Reis Bruno , Costas Benjamin , Lima Sofia A. Costa , Reis Salette
Published: December 2020

Exploiting surface endocytosis receptors using carbohydrate-conjugated nanocarriers brings outstanding approaches to an efficient delivery towards a specific target. Macrophages are cells of innate immunity found throughout the body. Plasticity of macrophages is evidenced by alterations in phenotypic polarization in response to stimuli, and is associated with changes in effector molecules, receptor expression, and cytokine profile. M1-polarized macrophages are involved in pro-inflammatory responses while M2 macrophages are capable of anti-inflammatory response and tissue repair. Modulation of macrophages’ activation state is an effective approach for several disease therapies, mediated by carbohydrate-coated nanocarriers. In this review, polymeric nanocarriers targeting macrophages are described in terms of production methods and conjugation strategies, highlighting the role of mannose receptor in the polarization of macrophages, and targeting approaches for infectious diseases, cancer immunotherapy, and prevention. Translation of this nanomedicine approach still requires further elucidation of the interaction mechanism between nanocarriers and macrophages towards clinical applications.
Thermal Behaviour of Common Thermoresponsive Polymers in Phosphate Buffer and in Its Salt Solutions
Authors: Otulakowski Łukasz , Kasprów Maciej , Strzelecka Aleksandra , Dworak Andrzej , Trzebicka Barbara
Published: December 2020

Thermoresponsive polymers are a promising material for drug nanocarrier preparation, which makes the study of their aggregation in physiological conditions very important. In this paper, the thermal behaviour of the thermoresponsive polymers poly(N-isopropylacrylamide), poly(2-isopropyl-2-oxazoline-co-2-n-propyl-2-oxazoline) and poly[(2-hydroxyethyl methacrylate)-co-oligo(ethylene glycol) methyl ether methacrylate] were studied in phosphate buffer (PBS) and solutions of its salts in concentration as in PBS. The thermal response of the polymers was measured using UV-Vis and dynamic light scattering (DLS). The salts shifted the cloud point temperature (TCP) of the (co)polymers to higher values compared to the TCP of aqueous polymer solutions. In PBS and NaCl solutions, all polymers exhibited an unexpected and previously unreported transmittance profile. During heating, an additional aggregation of polymers appeared above the TCP accompanied by the formation of a precipitate. In monosodium phosphate solutions and pure water, the studied polymers showed lower critical solution temperature (LCST-type) behaviour. DLS measurements showed that a salt influenced the size of the resulting polymer particles. The sizes and stability of particles depended on the heating rate. In PBS and NaCl solutions, the size of particles in the dispersion decreased above 60 °C, and the precipitate appeared on the bottom of the cuvette. The additional aggregation of polymer and its falling out of solution may hinder the removal of carriers from the body and has to be taken into account when preparing nanocarriers.
Optimization of the Electrochemical Performance of a Composite Polymer Electrolyte Based on PVA-K2CO3-SiO2 Composite
Authors: Abdulkadir Bashir Abubakar , Ojur Dennis John , Al-Hadeethi Yas , Shukur Muhammad Fadhlullah Bin Abd. , Mkawi E. M. , Al-Harbi Nuha , Ibnaouf K. H. , Aldaghri O. , Usman Fahad , Abbas Adam Abdullahi
Published: December 2020

Composite polymer electrolyte (CPE) based on polyvinyl alcohol (PVA) polymer, potassium carbonate (K2CO3) salt, and silica (SiO2) filler was investigated and optimized in this study for improved ionic conductivity and potential window for use in electrochemical devices. Various quantities of SiO2 in wt.% were incorporated into PVA-K2CO3 complex to prepare the CPEs. To study the effect of SiO2 on PVA-K2CO3 composites, the developed electrolytes were characterized for their chemical structure (FTIR), morphology (FESEM), thermal stabilities (TGA), glass transition temperature (differential scanning calorimetry (DSC)), ionic conductivity using electrochemical impedance spectroscopy (EIS), and potential window using linear sweep voltammetry (LSV). Physicochemical characterization results based on thermal and structural analysis indicated that the addition of SiO2 enhanced the amorphous region of the PVA-K2CO3 composites which enhanced the dissociation of the K2CO3 salt into K+ and CO32− and thus resulting in an increase of the ionic conduction of the electrolyte. An optimum ionic conductivity of 3.25 × 10−4 and 7.86 × 10−3 mScm−1 at ambient temperature and at 373.15 K, respectively, at a potential window of 3.35 V was observed at a composition of 15 wt.% SiO2. From FESEM micrographs, the white granules and aggregate seen on the surface of the samples confirm that SiO2 particles have been successfully dispersed into the PVA-K2CO3 matrix. The observed ionic conductivity increased linearly with increase in temperature confirming the electrolyte as temperature-dependent. Based on the observed performance, it can be concluded that the CPEs based on PVA-K2CO3-SiO2 composites could serve as promising candidate for portable and flexible next generation energy storage devices.
Separation and Semi-Empiric Modeling of Ethanol–Water Solutions by Pervaporation Using PDMS Membrane
Authors: Bermudez Jaimes John , Torres Alvarez Mario , Bannwart de Moraes Elenise , Wolf Maciel Maria , Maciel Filho Rubens
Published: December 2020

High energy demand, competitive fuel prices and the need for environmentally friendly processes have led to the constant development of the alcohol industry. Pervaporation is seen as a separation process, with low energy consumption, which has a high potential for application in the fermentation and dehydration of ethanol. This work presents the experimental ethanol recovery by pervaporation and the semi-empirical model of partial fluxes. Total permeate fluxes between 15.6–68.6 mol m−2 h−1 (289–1565 g m−2 h−1), separation factor between 3.4–6.4 and ethanol molar fraction between 16–171 mM (4–35 wt%) were obtained using ethanol feed concentrations between 4–37 mM (1–9 wt%), temperature between 34–50 ∘C and commercial polydimethylsiloxane (PDMS) membrane. From the experimental data a semi-empirical model describing the behavior of partial-permeate fluxes was developed considering the effect of both the temperature and the composition of the feed, and the behavior of the apparent activation energy. Therefore, the model obtained shows a modified Arrhenius-type behavior that calculates with high precision the partial-permeate fluxes. Furthermore, the versatility of the model was demonstrated in process such as ethanol recovery and both ethanol and butanol dehydration.
Preparation and Characterization of Starch/Empty Fruit Bunch-Based Bioplastic Composites Reinforced with Epoxidized Oils
Authors: Yang Jianlei , Ching Yern Chee , Chuah Cheng Hock , Liou Nai-Shang
Published: December 2020

This study examined the development of starch/oil palm empty fruit bunch-based bioplastic composites reinforced with either epoxidized palm oil (EPO) or epoxidized soybean oil (ESO), at various concentrations, in order to improve the mechanical and water-resistance properties of the bio-composites. The SEM micrographs showed that low content (0.75 wt%) of epoxidized oils (EOs), especially ESO, improved the compatibility of the composites, while high content (3 wt%) of EO induced many voids. The melting temperature of the composites was increased by the incorporation of both EOs. Thermal stability of the bioplastics was increased by the introduction of ESO. Low contents of EO led to a huge enhancement of tensile strength, while higher contents of EO showed a negative effect, due to the phase separation. The tensile strength increased from 0.83 MPa of the control sample to 3.92 and 5.42 MPa for the composites with 1.5 wt% EPO and 0.75 wt% ESO, respectively. EOs reduced the composites’ water uptake and solubility but increased the water vapor permeability. Overall, the reinforcing effect of ESO was better than EPO. These results suggested that both EOs can be utilized as modifiers to prepare starch/empty-fruit-bunch-based bioplastic composites with enhanced properties.
On the Use of the Discrete Constant pH Molecular Dynamics to Describe the Conformational Space of Peptides
Authors: Privat Cristian , Madurga Sergio , Mas Francesc , Rubio-Martínez Jaime
Published: December 2020

Solvent pH is an important property that defines the protonation state of the amino acids and, therefore, modulates the interactions and the conformational space of the biochemical systems. Generally, this thermodynamic variable is poorly considered in Molecular Dynamics (MD) simulations. Fortunately, this lack has been overcome by means of the Constant pH Molecular Dynamics (CPHMD) methods in the recent decades. Several studies have reported promising results from these approaches that include pH in simulations but focus on the prediction of the effective pKa of the amino acids. In this work, we want to shed some light on the CPHMD method and its implementation in the AMBER suitcase from a conformational point of view. To achieve this goal, we performed CPHMD and conventional MD (CMD) simulations of six protonatable amino acids in a blocked tripeptide structure to compare the conformational sampling and energy distributions of both methods. The results reveal strengths and weaknesses of the CPHMD method in the implementation of AMBER18 version. The change of the protonation state according to the chemical environment is presumably an improvement in the accuracy of the simulations. However, the simulations of the deprotonated forms are not consistent, which is related to an inaccurate assignment of the partial charges of the backbone atoms in the CPHMD residues. Therefore, we recommend the CPHMD methods of AMBER program but pointing out the need to compare structural properties with experimental data to bring reliability to the conformational sampling of the simulations.
Dynamic Stability Analysis in Hybrid Nanocomposite Polymer Beams Reinforced by Carbon Fibers and Carbon Nanotubes
Authors: Keshtegar Behrooz , Kolahchi Reza , Eyvazian Arameh , Trung Nguyen-Thoi
Published: December 2020

The objective of this innovative research is assessment of dynamic stability for a hybrid nanocomposite polymer beam. The considered beam formed by multiphase nanocomposite, including polymer–carbon nanotubes (CNTs)–carbon fibers (CFs). Hence, as to compute the effective material characteristics related to multiphase nanocomposite layers, the Halpin–Tsai model, as well as micromechanics equations are employed. To model the structure realistically, exponential shear deformation beam theory (ESDBT) is applied and using energy methods, governing equations are achieved. Moreover, differential quadrature method (DQM) as well as Bolotin procedures are used for solving the obtained governing equations and the dynamic instability region (DIR) relative to the beam is determined. To extend this novel research, various parameters pinpointing the influences of CNT volume fraction, CFs volume percent, boundary edges as well as the structure’s geometric variables on the dynamic behavior of the beam are presented. The results were validated with the theoretical and experimental results of other published papers. The outcomes reveal that increment of volume fraction of CNT is able to shift DIR to more amounts of frequency. Further, rise of carbon fibers volume percent leads to increase the excitation frequency of this structure.
Antibacterial Activity of N,O-Acylated Chitosan Derivative
Authors: Piegat Agnieszka , Żywicka Anna , Niemczyk Agata , Goszczyńska Agata
Published: December 2020

The antibacterial activity of N,O-acylated chitosan derivative with linoleic acid (CH_LA) was tested by disc and well diffusion, agar impregnation and microdilution methods against Staphylococcus aureus, Escherichia coli and Helicobacter pylori strains. Hydrophobically modified chitosan (HMC) was expected to exhibit enhanced antibacterial activity and specific mucin interactions. Although diffusion tests have not indicated the antibacterial potential of chitosan (CH) or CH_LA, the results of the microdilution method demonstrated that tested polymers significantly reduced the amount of living bacteria cells in different concentrations depending on the microorganism. Additionally, CH_LA was characterized by enhanced antibacterial activity compared to CH, which may suggest a different mechanism of interaction with S. aureus and H. pylori. Furthermore, the UV-VIS analysis revealed that the amphiphilic character of derivative led to strong CH_LA–mucin interactions. The study proved the high potential of CH_LA in antibacterial applications, especially for the gastrointestinal tract.
Expression of the Thermobifida fusca β-1,3-Glucanase in Yarrowia lipolytica and Its Application in Hydrolysis of β-1,3-Glucan from Four Kinds of Polyporaceae
Authors: Chen Wei-Lin , Hsu Jo-Chieh , Lim Chui-Li , Chen Cheng-Yu , Yang Chao-Hsun
Published: December 2020

The gene encoding a thermostable β-1,3-glucanase was cloned from Thermobifida fusca and expressed constitutively by Yarrowia lipolytica using plasmid pYLSC1. The expression level of the recombinant β-1,3-glucanase reached up to 270 U/mL in the culture medium. After a treatment with endo-β-N-acetyl-glucosaminidase H, the recombinant protein appeared as a single protein band, with a molecular size of approximately 66 kDa on the SDS-polyacrylamide gel. The molecular weight was consistent with the size predicted from the nucleotide sequence. The optimum temperature and pH of the transformant β-1,3-glucanase were 60 °C and pH 8.0, respectively. This β-1,3-glucanase was tolerant to 10% methanol, ethanol, and DMSO, retaining 70% activity. The enzyme markedly hydrolyzed Wolfiporia cocos and Pycnoporus sanguineus glucans. The DPPH and ABTS scavenging potential, reducing power and total phenolic contents of these two Polyporaceae hydrolysates, were significantly increased after 18 h of the enzymatic reaction. The present results indicate that T. fusca β-1,3-glucanase from Y. lipolytica transformant (pYLSC1-13g) hydrolyzes W. cocos and P. sanguineus glucans and improves the antioxidant potential of the hydrolysates.
Fabrication and Analysis of Polydimethylsiloxane (PDMS) Microchannels for Biomedical Application
Authors: Tayyaba Shahzadi , Ashraf Muhammad Waseem , Ahmad Zubair , Wang Ning , Afzal Muhammad Javaid , Afzulpurkar Nitin
Published: December 2020

In this research work, Polydimethylsiloxane (PDMS) has been used for the fabrication of microchannels for biomedical application. Under the internet of things (IoT)-based controlled environment, the authors have simulated and fabricated bio-endurable, biocompatible and bioengineered PDMS-based microchannels for varicose veins implantation exclusively to avoid tissue damaging. Five curved ascending curvilinear micro-channel (5CACMC) and five curved descending curvilinear micro-channels (5CDCMC) are simulated by MATLAB (The Math-Works, Natick, MA, USA) and ANSYS (ANSYS, The University of Lahore, Pakistan) with actual environments and confirmed experimentally. The total length of each channel is 1.6 cm. The diameter of both channels is 400 µm. In the ascending channel, the first to fifth curve cycles have the radii of 2.5 mm, 5 mm, 7.5 mm, 10 mm, and 2.5 mm respectively. In the descending channel, the first and second curve cycles have the radii of 12.5 mm and 10 mm respectively. The third to fifth cycles have the radii of 7.5 mm, 5 mm, and 2.5 mm respectively. For 5CACMC, at Reynolds number of 185, the values of the flow rates, velocities and pressure drops are 19.7 µLs−1, 0.105 mm/s and 1.18 Pa for Fuzzy simulation, 19.3 µLs−1, 0.1543 mm/s and 1.6 Pa for ANSYS simulation and 18.23 µLs−1, 0.1332 mm/s and 1.5 Pa in the experiment. For 5CDCMC, at Reynolds number 143, the values of the flow rates, velocities and pressure drops are 15.4 µLs−1, 0.1032 mm/s and 1.15 Pa for Fuzzy simulation, 15.0 µLs−1, 0.120 mm/s and 1.22 Pa for ANSYS simulation and 14.08 µLs−1, 0.105 mm/s and 1.18 Pa in the experiment. Both channels have three inputs and one output. In order to observe Dean Flow, Dean numbers are also calculated. Therefore, both PDMS channels can be implanted in place of varicose veins to have natural blood flow.
A Discrete Element Method Study of Solids Stress in Cylindrical Columns Using MFiX
Authors: Marchelli Filippo , Di Felice Renzo
Published: December 2020

Friction phenomena play a key role in discrete element method (DEM) modeling. To analyze this aspect, we employed the open-source program MFiX to perform DEM simulations of cylindrical vertical columns filled with solid particles. These are still associated with and described by the pioneering model by the German engineer H.A. Janssen. By adapting the program’s code, we were able to gather numerous insights on the stress distribution within the solids. The column was filled with different amounts of solids and, after the system had stabilized, we assessed the pressure in the vertical and radial directions and the distribution of the friction force for all particles. An analysis of the bottom pressure for varying particle loads allowed us to infer that the program can correctly predict the expected asymptotical behavior. After a detailed assessment of the behavior of a single system, we performed a sensitivity analysis taking into account several of the variables employed in the simulations. The friction coefficient and filling rate seem to affect the final behavior the most. The program appears suitable to describe friction phenomena in such a static system.
Bandwidth Detection of Graph Signals with a Small Sample Size
Authors: Xie Xuan , Feng Hui , Hu Bo
Published: December 2020

Bandwidth is the crucial knowledge to sampling, reconstruction or estimation of the graph signal (GS). However, it is typically unknown in practice. In this paper, we focus on detecting the bandwidth of bandlimited GS with a small sample size, where the number of spectral components of GS to be tested may greatly exceed the sample size. To control the significance of the result, the detection procedure is implemented by multi-stage testing. In each stage, a Bayesian score test, which introduces a prior to the spectral components, is adopted to face the high dimensional challenge. By setting different priors in each stage, we make the test more powerful against alternatives that have similar bandwidth to the null hypothesis. We prove that the Bayesian score test is locally most powerful in expectation against the alternatives following the given prior. Finally, numerical analysis shows that our method has a good performance in bandwidth detection and is robust to the noise.
How Does Inter-Organizational Cooperation Impact Organizations’ Scientific Knowledge Generation? Evidence from the Biomass Energy Field
Authors: Li Liu , Tang Chaoying
Published: December 2020

Previous studies have demonstrated that accessing external knowledge is important for organizations’ knowledge generation. The main purpose of this study is to investigate how the diversity and amount of organizations’ external scientific knowledge influence their scientific knowledge generation. We also consider the moderating effect of the redundant industrial scientific knowledge and the amount of technical knowledge from external technical cooperators. The social network analysis method is used to establish both ego- and industrial-scientific cooperation network, and ego-technical cooperation network in order to analyze the external scientific knowledge and technical knowledge. The empirical analysis is based on patent and article data of 106 organizations in the biomass energy industry (including firms, universities and research institutes), and the results show that organizations’ structural holes and degree centrality of scientific cooperation network have positive effects on their scientific knowledge generation. In addition, organizations’ degree centrality of technical cooperation network positively moderates the relationship between their degree centrality of scientific cooperation network and scientific knowledge generation. Furthermore, density of industrial scientific cooperation network decreases the positive effect of organizations’ structural holes on their scientific knowledge generation, while it strengthens the positive effect of degree centrality of scientific cooperation network on their scientific knowledge generation. Academic contributions and practical suggestions are discussed.
Transportation Carbon Emissions from a Perspective of Sustainable Development in Major Cities of Yangtze River Delta, China
Authors: Liu Jialin , Zhu Yi , Zhang Qun , Cheng Fangyan , Hu Xi , Cui Xinhong , Zhang Lang , Sun Zhenglin
Published: December 2020

Since the late 1990s, the Yangtze River Delta (YRD) has experienced profound growth in economic scales and urban size. However, it is still unclear how much energy is consumed from both fossil fuel and electricity usage for transportation sectors (TCO2). We take 10 sampled cities in the YRD as examples and examine their city-level sustainable levels from 1990 to 2018. Then, we observed that SHSN (Shanghai, Suzhou, Nanjing) are in leading positions, followed by WCN (Wuxi, Changzhou, Ningbo) and NXH (Nantong, Xuzhou, Hefei). We found that the cumulative TCO2 in SHSN from 1990 to 2018 is the highest among groups, which is mainly due to the earlier industrialization in history. In 2018, SHSN had the highest TCO2 (623.9 × 104 t), WCN was 311.9 × 104 t, and NXH was 166.4 × 104 t. TCO2 per capita in SHSN reached its minimal (≈0.12 t) in 2018 among 29 years, while WCN and NXH shared the same levels (≈0.07 t). This could be attributed to the dense population and a series of low carbon policies announced in SHSN and WCN. NXH is still in the stage of high demands on economic-centered development. The primary source for TCO2 in the YRD is fossil fuels. The TCO2 contributed by transportation electricity usage is continually increasing, especially after 2010. This phenomenon represents that electricity can be a significant part of the YRD’s transportation sectors’ energy consumption shortly. A complex estimation model uncovers the complexity between the economy, environment, and carbon emissions in the YRD, which indicated that the decrease of TCO2 in YRD could not be regulated solely by economic or environmental interventions. This study highlighted the urgency for socio-economic adjustments from carbonized to decarbonized structures in the YRD.
Deciphering Soil Spatial Variability through Geostatistics and Interpolation Techniques
Authors: AbdelRahman Mohamed A. E. , Zakarya Yasser M. , Metwaly Mohamed M. , Koubouris Georgios
Published: December 2020

Detailed knowledge of soil properties is fundamentally important for optimizing agriculture practices and management. Meanwhile, the spatial distribution of soil physicochemical properties is considered a fundamental input of any sustainable agricultural planning. In the present study, ordinary kriging, regression kriging and IDW were chosen for deciphering soil spatial variability and mapping soil properties in a reclaimed area of the Behera Governorate of Egypt where soil arose from two different types, one sandstone and the other limestone. Geostatistics were used to show the interrelationships and conditions of soil properties (available phosphorus, potassium and nitrogen, EC, pH, Sp, ESP, CEC, OC, SAR, and CaCO3). The results of mapping spatial soil variability by Geostatistics could be used for precision agriculture applications. Based on the soil test results, nutrient management recommendations should be applied regarding variable rates of fertilizers. The performance of the maps was evaluated using Mean square error (MSE). Inverse distance weight (IDW) showed higher efficiency than Kriging as a prediction method for mapping the studied soil properties in the study area. The results of the present study suggest that the application of the selected fit model worldwide in any relevant study of soil properties of different geological sources is feasible.
Analysis of Factors Affecting the Environmental Impact of Concrete Structures
Authors: Wałach Daniel
Published: December 2020

Concrete is the one of the most important construction materials not only in terms of its global consumption but also environmental impact. However, there are many possibilities to reduce the environmental impact of concrete structures. This paper presents a set of factors determining the environmental impact of subsequent stages in the life cycles of concrete objects. In the research, the method of deduction and mathematical logic was applied to identify the parameters. Using the DEMATEL method, the significance of the identified factors was determined. An influential relation map allowed to specify a set of important parameters (causes) that affect the impact of the structure on the environment. The most important causes include: Concrete class, structural loads, static of the structure, materials used, and their suppliers as well as the volume of structural elements. The results of the analysis both confirmed the previous findings, as well as shows a set of indicators not previously highlighted. The cause-and-effect relationships between the parameters, and its significance was also determined. The results enable to indicate further directions of reducing the environmental impact of the concrete structure.
Using Travel Times for Optimization Numbers of Medical Rescue Service Points—Case Study from Slovakia
Authors: Strohmandl Jan , Tomek Miroslav , Molnár Vieroslav , Jakubčeková Júlia Mihoková , Fedorko Gabriel , Maláková Silvia
Published: December 2020

Health care and protection is one of the fundamental human rights, which apply to all people of the world. Life and health threats can occur at any place and time, both at times of peace and security and at times of emergencies of any kind. In many cases, provision of urgent medical care creates a time strain. Emergency medical care in the Slovak Republic is provided by a medical rescue service, including mobile emergency care and ambulances, with or without a doctor. The present article deals with the purpose and role of medical rescue service with an emphasis on mobile emergency care provision by ambulances. The following part defines selected factors affecting medical rescue service station locations and numbers of ambulances. Emphasis is laid on an analysis of theoretical assumptions for optimization of the number of medical rescue service stations and ambulances used by them for the purpose of securing care of life and health of the population and addressing emergencies within selected territorial units in the Self-Governing Region of Žilina. The proposed optimization of the number of medical rescue service stations in municipalities is addressed theoretically as a location issue. The resulting theoretical variant of the proposed new distribution of medical rescue service ambulance stations is a mathematical consideration of assurance of emergency medical care provision within 15 min from each event reporting. The mathematical algorithm used for the proposal of medical rescue service ambulance station distribution is applicable in different regions and countries with a defined time to provision of first aid and emergency medical care.
The Spatial Correlation and Explanation of the Evolution of China’s Regional Human Capital Structure—Based on Network Analysis Method
Authors: Dai Xiao , Yan Liang
Published: December 2020

Human capital is an important catalyst for technology to play its role and the key to ensuring regional sustainable development. The current research on human capital mainly considers the imbalance of its stock and regional distribution without of the overall description of human capital structure and an analysis of its spatial correlation. Therefore, this article first builds a model of human capital structure evolution (HCSE) based on primary human capital, advanced human capital combined with economic geographic weight matrix, then uses the network analysis method to make a new deconstruction of the spatial correlation characteristics and the factors of China’s regional HCSE from 2009 to 2018. The results show that: (1) China’s HCSE has experienced regional accumulation in 2012, 2015, and 2018, having more prominent path dependence characteristics, which moreover vary significantly with China’s provinces, that is, the eastern region is dominated by the path of outward overflow, and the central and western regions alternate inward input and outward output; (2) The spatial network of HCSE in China is stable and multi-superimposed. During the sample investigation period, the overall network density first increased and then decreased, the largest regional clustering coefficient and transmission efficiency appeared in 2014; (3) The eastern region (Beijing, Shanghai, and Guangdong as the core) is at the center of network spillover, playing a pivotal role as well as an intermediary and bridge role; conversely, the western region plays a central role in promoting the spatial network of HCSE to the direction of external dependence, while most of the central region has a diminished role in the evolution of spatial association networks; (4) The spatial correlation of HCSE in China is mainly affected by three types of factors: the urbanization level, the investment scale, and the degree of regional development. The greater the difference in urbanization levels is, the closer the spatial correlation of HCSE and the higher its network efficiency is; while the difference in investment scale and regional development has the opposite effect.
Feeding Models to Optimize Dairy Feed Rations in View of Feed Availability, Feed Prices and Milk Production Scenarios
Authors: Alqaisi Othman , Schlecht Eva
Published: December 2020

In the global dairy production sector, feed ingredient price and availability are highly volatile; they may shape the composition of the feed ration and, in consequence, impact feed cost and enteric methane (CH4) emissions. The objective of this study is to explore the impact of changes in feed ingredients’ prices and feed ingredients’ availability on dairy ration composition, feed cost and predicted methane yield under different levels of milk production. To meet the research aim, a series of multi-period linear programming models were developed. The models were then used to simulate 14 feed rations formulations, each covering 162 months and three dairy production levels of 10, 25 and 35 kg milk/d, representing a total of 6804 feed rations altogether. Across milk production levels, the inclusion of alfalfa hay into the feed rations declined from 55% to 38% when daily milk production increased from 10 to 35 kg, reflecting the cows’ increased energy requirements. At a daily milk production level of 35 kg, CH4 production (per kg milk) was 21% and 53% lower than in average and low milk producing cows, respectively, whereas at 10 kg of milk production the potential to reduce CH4 production varied between 0.6% and 5.5% (average = 3.9%). At all production levels, a reduction in CH4 output was associated with an increase in feed costs. Overall, and considering feeding scenarios in low milk producing cows, feed cost per kg milk was 30% and 37% higher compared to that of average and high milk production, respectively. The feed ration modeling approach allows us to account for the interaction between feed ingredients over time, taking into consideration volatile global feed prices. Overall, the model provides a decision-making tool to improve the use of feed resources in the dairy sector.
New Business Models from Prescriptive Maintenance Strategies Aligned with Sustainable Development Goals
Authors: Grijalvo Martín Mercedes , Pacios Álvarez Antonia , Ordieres-Meré Joaquín , Villalba-Díez Javier , Morales-Alonso Gustavo
Published: December 2020

The industry has entered on the Fourth Industrial Revolution, the so-called Industry 4.0, with global markets and strong competition, some traditional manufacturing firms are implementing new maintenance innovations and policies, based on digitalisation and data driven approach, but also based on servitisation. The implementation of these new equipment maintenance business models, could require new organisational approach at different levels. Different sorts of integration are arranged, in vertical with a flat structure of intelligent, flexible and autonomous units working integrated, in horizontal with a strong external and internal supply chain integration, and in transverse, with an integrated approach that link internal and external stakeholders. A new prescriptive maintenance business model for equipment exploiting digitalisation opportunities, including stakeholder relationship is proposed. Different perspectives such as organisational, innovation and sustainability have been adopted to discuss the implications of the proposal. The social value potentially gained as well as the alignment with the SDGs are discussed as well.
Analysis of Heteronormativity and Gender Roles in EFL Textbooks
Authors: Ruiz-Cecilia Raúl , Guijarro-Ojeda Juan Ramón , Marín-Macías Carmen
Published: December 2020

This paper examines the current representations of gender roles and heteronormativity in a corpus of textbooks used to teach English as a Foreign Language (EFL) in Spanish high schools. Several studies have documented the importance of recognizing problems of homophobic harassment and gender bias which may result in a significant number of students feeling excluded. It is notable that textbook publishers have failed to address this issue despite its relevance to the United Nations’ Sustainable Development Goals (SDGs), raising the question of why this continues to go unnoticed by textbook publishers. The corpus selected comprises two sets of textbooks printed by leading publishers in the area of EFL. In order to gain insight into this issue, we have conducted a qualitative study analyzing the role of textbooks in perpetuating heteronormativity and stereotyped gender roles by exemplifying the naturalized heterosexual and male/female identities. Data were coded under two broad variables: heteronormativity and gender, which in turn were broken down into different units of analysis. The results suggested that heteronormativity still permeates the whole curriculum and that attempts to gender-balance need to be improved by reducing the number of male protagonists. Textbooks fell into some of the same clichés with regard to gender-related stereotypes, such as almost exclusively linking women with shopping and fashion. It is evidently clear from the findings that textbooks should be revised to ensure the right to quality education for all and to make students aware of SDGs, since 7 out of 17 are related to the target topics.
Fixed Point of Interpolative Rus–Reich–Ćirić Contraction Mapping on Rectangular Quasi-Partial b-Metric Space
Authors: Gautam Pragati , Sánchez Ruiz Luis Manuel , Verma Swapnil
Published: December 2020

The purpose of this study is to introduce a new type of extended metric space, i.e., the rectangular quasi-partial b-metric space, which means a relaxation of the symmetry requirement of metric spaces, by including a real number s in the definition of the rectangular metric space defined by Branciari. Here, we obtain a fixed point theorem for interpolative Rus–Reich–Ćirić contraction mappings in the realm of rectangular quasi-partial b-metric spaces. Furthermore, an example is also illustrated to present the applicability of our result.
Testing Symmetrical Knot Tracing for Cognitive Priming Effects Rules out Analytic Analogy
Authors: Vahedi Zahra , Pelkey Jamin , Park Sari , Walsh Matthews Stéphanie
Published: December 2020

Ritual knots are symmetrical crisscrossing designs that appear in distant cultures around the world. Their independent emergence is plausibly due to shared features of human cognition and experience that such patterns represent. Since empirical investigation of this possibility is lacking in the literature, our aim is to open up this research area. We do so by asking whether the cultural production and appreciation of ritual knots could be conditioned or motivated by alignments and affordances linked to creative human cognition—advanced analogical modeling processes that are themselves often discussed in terms of bidirectional blending and symmetrical mapping. If manual tracing of a traditional knot design had positive priming effects on such reasoning processes, as we hypothesize, this would suggest an explanatory link between the two. To begin testing this hypothesis, we selected a basic, traditional knot design from Tibet, along with three established measures of formal analogical reasoning and one original measure of syntactic preference involving reciprocal constructions. We then undertook a series of cognitive trials testing for potential cognitive benefits of manually tracing the design. We contrasted prime condition results with a control group and an anti-prime condition group. The data show observable effects of time across multiple measures but no significant effects of time or condition, controlling for reported mindfulness. While this rules out the short-term priming effects of enhanced analogical reasoning at the analytic level following brief manual tracing of this design, the research opens the way for further empirical experimentation on the nature and emergence of symmetrical knots and their potential relationships with patterns of human thought.