bluuebunny/crossref_metadata_2025 huggingface dataset:
The IRC Indices of Transformation and Derived Graphs
Authors: Luo Haichang , Hayat Sakander , Zhong Yubin , Peng Zhongyuan , Réti Tamás
Published: March 2022

An irregularity index IR(Γ) of a graph Γ is a nonnegative numeric quantity (i.e., IR(Γ)≥0) such that IR(Γ)=0 iff Γ is a regular graph. In this paper, we show that IRC closely correlates with the normal boiling point Tbp and the standard heat of formation ΔHfo of lower benzenoid hydrocarbons. The correlation models that fit the data efficiently for both Tbp and ΔHfo are linear. We develop further mathematical properties of IRC by calculating its exact expressions for the recently introduced transformation graphs as well as certain derived graphs, such as the total graph, semi-total point graph, subdivision graph, semi-total line graph, double, strong double, and extended double cover graphs. Some open problems are proposed for further research on the IRC index of graphs.
Schrödinger Harmonic Functions with Morrey Traces on Dirichlet Metric Measure Spaces
Authors: Shen Tianjun , Li Bo
Published: March 2022

Assume that (X,d,μ) is a metric measure space that satisfies a Q-doubling condition with Q>1 and supports an L2-Poincaré inequality. Let 𝓛 be a nonnegative operator generalized by a Dirichlet form E and V be a Muckenhoupt weight belonging to a reverse Hölder class RHq(X) for some q≥(Q+1)/2. In this paper, we consider the Dirichlet problem for the Schrödinger equation −∂t2u+𝓛u+Vu=0 on the upper half-space X×R+, which has f as its the boundary value on X. We show that a solution u of the Schrödinger equation satisfies the Carleson type condition if and only if there exists a square Morrey function f such that u can be expressed by the Poisson integral of f. This extends the results of Song-Tian-Yan [Acta Math. Sin. (Engl. Ser.) 34 (2018), 787-800] from the Euclidean space RQ to the metric measure space X and improves the reverse Hölder index from q≥Q to q≥(Q+1)/2.
On Ostrowski Type Inequalities via the Extended Version of Montgomery’s Identity
Authors: Khan Asif R. , Nabi Hira , Pečarić Josip E.
Published: March 2022

In this paper, we obtain new Ostrowski type inequalities by using the extended version of Montgomery identity and Green’s functions. We also give estimations of the difference between two integral means.
Numerical Results on Slip Effect over an Exponentially Stretching/Shrinking Cylinder
Authors: Najib Najwa , Bachok Norfifah , Dzulkifli Nor Fadhilah , Pop Ioan
Published: March 2022

An investigation is conducted to study the flow and heat transfer on stagnation point over an exponentially stretching/shrinking cylinder filled with nanofluid in the presence of slip at the boundary. By using the appropriate exponential similarity transformation, the governing equations are converted into nonlinear ordinary differential equations and then solved computationally using bvp4c in Matlab software. The results of skin friction coefficient, heat transfer coefficient, velocity and temperature profiles on slip parameter, curvature parameter, nanoparticles as well as nanoparticle volume fraction parameter are presented graphically. The presence of slip and curvature parameters cause the region of dual solutions to expand and at once enhance the heat transfer rate at the surface but somehow the heat transfer rate at the surface decreases rapidly when cylinder is shrunk. The aim of this paper is to investigate the effect of slip parameter on nanofluid as well as on the stretching/shrinking surface. The new findings of the effects of skin friction and heat transfer coefficient on different nanoparticles and nanoparticle volume fraction were discussed. Since there are dual solutions in the flow characteristics, we carry out a stability analysis to verify which solution is in a stable state and can be realized physically.
Riemannian Formulation of Pontryagin’s Maximum Principle for the Optimal Control of Robotic Manipulators
Authors: Rojas-Quintero Juan Antonio , Dubois François , Ramírez-de-Ávila Hedy César
Published: March 2022

In this work, we consider robotic systems for which the mass tensor is identified to be the metric in a Riemannian manifold. Cost functional invariance is achieved by constructing it with the identified metric. Optimal control evolution is revealed in the form of a covariant second-order ordinary differential equation featuring the Riemann curvature tensor that constrains the control variable. In Pontryagin’s framework of the maximum principle, the cost functional has a direct impact on the system Hamiltonian. It is regarded as the performance index, and optimal control variables are affected by this fundamental choice. In the present context of cost functional invariance, we show that the adjoint variables are the first-order representation of the second-order control variable evolution equation. It is also shown that adding supplementary invariant terms to the cost functional does not modify the basic structure of the optimal control covariant evolution equation. Numerical trials show that the proposed invariant cost functionals, as compared to their non-invariant versions, lead to lower joint power consumption and narrower joint angular amplitudes during motion. With our formulation, the differential equations solver gains stability and operates dramatically faster when compared to examples where cost functional invariance is not considered.
Bioactive Compounds from Marine Sediment Derived Fungi
Authors: Yurchenko Ekaterina A.
Published: March 2022

Marine sediment derived fungi are a very interesting source of biologically active compounds [...]
Microstructure and Properties of Novel Mg-Al-Zn-Mn-Ca-Ni Dissoluble Alloy Fabricated by Industrial Two-Step Extrusion Method
Authors: Wang Jian , Li Hongxiang , Wang Jinhui , Liu Yaohong , Zhang Jishan
Published: March 2022

Dissoluble magnesium alloys for fabrication of fracturing tools have received increasing attention in recent years. However, most of the existing research is focused on the small-sized samples prepared in the laboratory, and there is almost no report on the industrial dissoluble magnesium alloys. In this study, large-scale Mg-Al-Zn-Mn-Ca-Ni alloys with a diameter of 110 mm were prepared by a semi-continuous casting and two-step extrusion method, and the corresponding microstructure and mechanical and corrosion properties were also investigated. It was found that after two-step extrusion, the mainly precipitate phases in the Mg-Al-Zn-Mn-Ca-Ni alloy are bulk-like AlMnNi, strip-like Al3Ni, and granular-like and lamellar-like Mg17Al12 phases. Due to the combined effects of grain refinement and precipitation strengthening, the Mg-Al-Zn-Mn-Ca-Ni alloy obtained excellent mechanical properties after two-step extrusion, and its ultimate tensile strength, yield strength, and elongation were 314.6 MPa, 191.2 MPa, and 13.1%, respectively. Moreover, the corrosion rate of the alloy in 3 wt.% KCl at 93 °C was as high as 97.61 mg·cm−2·h−1. This work provides a high-performance, low-cost, and large-scale alloy product for the fabrication of dissoluble fracturing tools.
Alkaline Decomposition of Solid Solution of Ammonium-Sodium Jarosite with Arsenic
Authors: Flores Víctor H. , Patiño Francisco , Roca Antoni , Flores Mizraim U. , Reyes Iván A. , Reyes Martin , Islas Hernán
Published: March 2022

In this study, a solid solution of arsenical ammonium-sodium jarosite, with the approximate formula [(NH4)0.72 Na0.06(H3O)0.21]Fe3(2.52)(SO4)1.85 (AsO4)0.15 [(OH)4.41 (H2O)1.59], was synthesized. The precipitate particle main size was 38 µm, with spherical morphology. A decomposition reaction in alkaline media was carried out; this decomposition comprised three stages: an induction period, a progressive conversion and a stabilization period. The process was controlled by the chemical reaction, and the progressive conversion period was consistent with the shrinking core model. The dissolution reactions of the compound in NaOH media were characterized by an ash layer formed by solid residues made of Fe(OH)3 with adsorbed arsenate surrounding an unreacted core through which Na+, NH4+ and SO42− ions diffused into the solution. At the same time, OH− ions diffused from the solution into the reaction front until the core disappeared, indicating the end of the reaction.
Deformation Lenses in a Bonding Zone of High-Alloyed Steel Laminates Manufactured by Cold Roll Bonding
Authors: Seleznev Mikhail , Renzing Christoph , Schmidtchen Matthias , Prahl Ulrich , Biermann Horst , Weidner Anja
Published: March 2022

The combination of strength of transformation-induced plasticity (TRIP) steel and ductility of twinning-induced plasticity (TWIP) steel can be achieved by manufacturing laminated composites via cold roll bonding (CRB). Work hardening of the surface before CRB produces deformation lenses (DLs), which play significant role in bonding, but are reported rarely in the literature. The present work aimed to study the DLs at the bonding interface of the laminated composite made of high-alloy TRIP and TWIP steels manufactured by CRB. The DLs and interfaces were investigated by means of scanning and transmission electron microscopy, roughness measurement, tensile and peel tests. Laminates showed ultimate tensile strength up to 900 MPa and elongation up to 45% maintaining the layer’s integrity up to failure. The TWIP–TWIP interface has shown higher maximum peel strength (up to 195 N/cm) than that of a TRIP–TWIP interface (up to 130 N/cm), which was found to be in direct proportion to the overall area of DLs. Bonding of the laminate layers was found to occur between DL fragments.
Effect of Reaction Temperature and Heat Treatment Time on Electrical and Mechanical Performance of TiB2 Particles and TiB Whiskers Reinforced Copper Matrix Composites
Authors: Cao Fei , Zhang Xingde , Cai Pengtao , Jiang Yihui , Gao Fan , Liang Shuhua
Published: March 2022

In order to achieve a reasonable balance between the high electrical conductivity and high tensile strength of TiB2 particles (TiB2p) and TiB whiskers (TiBw) reinforced copper matrix composites prepared by in situ reaction casting, the effects of reaction temperature and heat treatment time on the electrical conductivity and tensile strength of composites were studied. The results show that the electrical conductivity increased while the tensile strength decreased with the increase in reaction temperature from 1300 °C to 1500 °C. With the increase in heat treatment time, the electrical conductivity increased, while the tensile strength of the composites increased first and then decreased. The electrical conductivity and tensile strength of composites are related to the degree of in situ reaction at liquid or solid state, and the reasons for the improved performance are also discussed. Finally, two optimized preparation processes are proposed by cooperative controlling the reaction temperature and heat treatment time, the comprehensive properties of (TiB2p+TiBw)/Cu composites are 79.6% IACS/603 MPa and 83.7% IACS/602 MPa, respectively.
Improving Effect of Graphene on Electrochemical Properties of Fe2O3 Anode Materials
Authors: Zhu Guanglin , Gao Bo , Tu Ganfeng , Liu Haifeng , Wang Ming
Published: March 2022

Transition metal oxides have a high initial charge-discharge capacity of 800–1000 mAh/g, the electrochemical performance, cyclic performance and rate performance of the composite of transition metal oxide and graphene have been improved due to the unique two-dimensional structure and excellent electrical conductivity of graphene. In this paper, iron oxides materials with different morphs were prepared by different hydrothermal reaction temperatures, and rGO/Fe2O3-175 °C composites with different graphene ratios were synthesized and used in the anode of lithium ion batteries. The results show that nanorod-shaped Fe2O3 had better electrochemical performance than spherical Fe2O3. 0.2rGO/Fe2O3-175 °C had the best cyclic performance, the first cyclic discharge capacity reaches 1372 mAh/g under the current density of 100 mA/g, and the cyclic reversible capacity remained at about 435 mAh/g after 50 cycles, illustrating that nanorods Fe2O3 and graphene composites can greatly buffer the volume expansion of Fe2O3.
Electric-Driven Polarization Meta-Optics for Tunable Edge-Enhanced Images
Authors: Cheng Cheng , Ou Kai , Yang Hui , Wan Hengyi , Wei Zeyong , Wang Zhanshan , Cheng Xinbin
Published: March 2022

In this study, we demonstrate an electrically driven, polarization-controlled metadevice to achieve tunable edge-enhanced images. The metadevice was elaborately designed by integrating single-layer metalens with a liquid-crystal plate to control the incident polarization. By modulating electric-driven voltages applied on the liquid-crystal plate, the metalens can provide two polarization-dependent phase profiles (hyperbolic phase and focusing spiral phase). Therefore, the metalens can perform two-dimensional focusing and spatial differential operation on an incident optical field, allowing dynamic switching between the bright-field imaging and the edge-enhanced imaging. Capitalizing on the compactness and dynamic tuning of the proposed metadevice, our scheme carves a promising path to image processing and biomedical imaging technology.
Three-Dimensional Large-Scale Fused Silica Microfluidic Chips Enabled by Hybrid Laser Microfabrication for Continuous-Flow UV Photochemical Synthesis
Authors: Zhang Aodong , Xu Jian , Li Yucen , Hu Ming , Lin Zijie , Song Yunpeng , Qi Jia , Chen Wei , Liu Zhaoxiang , Cheng Ya
Published: March 2022

We demonstrate a hybrid laser microfabrication approach, which combines the technical merits of ultrafast laser-assisted chemical etching and carbon dioxide laser-induced in situ melting for centimeter-scale and bonding-free fabrication of 3D complex hollow microstructures in fused silica glass. With the developed approach, large-scale fused silica microfluidic chips with integrated 3D cascaded micromixing units can be reliably manufactured. High-performance on-chip mixing and continuous-flow photochemical synthesis under UV irradiation at ~280 nm were demonstrated using the manufactured chip, indicating a powerful capability for versatile fabrication of highly transparent all-glass microfluidic reactors for on-chip photochemical synthesis.
Thin Film Encapsulation for LCP-Based Flexible Bioelectronic Implants: Comparison of Different Coating Materials Using Test Methodologies for Life-Time Estimation
Authors: Pak Anna , Nanbakhsh Kambiz , Hölck Ole , Ritasalo Riina , Sousa Maria , Van Gompel Matthias , Pahl Barbara , Wilson Joshua , Kallmayer Christine , Giagka Vasiliki
Published: March 2022

Liquid crystal polymer (LCP) has gained wide interest in the electronics industry largely due to its flexibility, stable insulation and dielectric properties and chip integration capabilities. Recently, LCP has also been investigated as a biocompatible substrate for the fabrication of multielectrode arrays. Realizing a fully implantable LCP-based bioelectronic device, however, still necessitates a low form factor packaging solution to protect the electronics in the body. In this work, we investigate two promising encapsulation coatings based on thin-film technology as the main packaging for LCP-based electronics. Specifically, a HfO2–based nanolaminate ceramic (TFE1) deposited via atomic layer deposition (ALD), and a hybrid Parylene C-ALD multilayer stack (TFE2), both with a silicone finish, were investigated and compared to a reference LCP coating. T-peel, water-vapour transmission rate (WVTR) and long-term electrochemical impedance spectrometry (EIS) tests were performed to evaluate adhesion, barrier properties and overall encapsulation performance of the coatings. Both TFE materials showed stable impedance characteristics while submerged in 60 °C saline, with TFE1-silicone lasting more than 16 months under a continuous 14V DC bias (experiment is ongoing). The results presented in this work show that WVTR is not the main factor in determining lifetime, but the adhesion of the coating to the substrate materials plays a key role in maintaining a stable interface and thus longer lifetimes.
An Accelerometer Based on All Silica In-Line Fiber Fabry-Perot Etalon for High Temperature up to 800 °C
Authors: Qian Jiang , Jia Pinggang , Ren Qianyu , Liu Hua , Qin Li , Xiong Jijun
Published: March 2022

High-temperature accelerometers have been widely used in aerospace, nuclear reactors, automobile technologies, etc. In this paper, a fiber-optic Fabry–Perot accelerometer (FOFPA) with a cantilever beam for high temperature is designed and experimentally demonstrated. The FOFPA is formed by bonding an all-silica in-line fiber Fabry–Perot etalon (ILFFPE) to one surface of the uniform cantilever beam with the lumped mass at the free end for acceleration measurement. The all silica in-line fiber FP etalon is made by welding two gold-coat single-mode fiber (GSMF) and a hollow silica glass tube (HST). The research results indicate that the sensitivity of the FOFPA is 0.02328rad/g, and the resonance frequency is 1146.6 Hz in the range of 1 g ~ 10 g. The high-temperature performance of the FOFPA was also evaluated. From 20 °C to 800 °C, the temperature drift is about 0.3178 nm/°C. The FOFPA has the potential of being applicable in higher temperatures compared to conventional accelerometers.
Photosynthesis, Respiration, and Growth of Five Benthic Diatom Strains as a Function of Intermixing Processes of Coastal Peatlands with the Baltic Sea
Authors: Prelle Lara R. , Karsten Ulf
Published: March 2022

In light of climate change, renaturation of peatlands has become increasingly important, due to their function as carbon sinks. Renaturation processes in the Baltic Sea include removal of coastal protection measures thereby facilitating exchange processes between peatland and Baltic Sea water masses with inhabiting aquatic organisms, which suddenly face new environmental conditions. In this study, two Baltic Sea and three peatland benthic diatom strains were investigated for their ecophysiological response patterns as a function of numerous growth media, light, and temperature conditions. Results clearly showed growth stimulation for all five diatom strains when cultivated in peatland water-based media, with growth dependency on salinity for the Baltic Sea diatom isolates. Nutrient availability in the peatland water resulted in higher growth rates, and growth was further stimulated by the carbon-rich peatland water probably facilitating heterotrophic growth in Melosira nummuloides and two Planothidium sp. isolates. Photosynthesis parameters for all five diatom strains indicated low light requirements with light saturated photosynthesis at <70 µmol photons m−2 s−1 in combination with only minor photoinhibition as well as eurythermal traits with slightly higher temperature width for the peatland strains. Growth media composition did not affect photosynthetic rates.
Deep Learning Based Granularity Detection Network for Mine Dump Materials
Authors: Cai Zhen , Lei Shaogang , Lu Xiaojuan
Published: March 2022

The granularity distribution of mine dump materials has received extensive attention as an essential research basis for dump stability and mine land reclamation. Image analysis is widely used as the fastest and most efficient method to obtain the granularity distribution of the dump materials. This article proposes a deep learning-based approach for granularity detection and identification of mine dump material, conglomerate, and clay. Firstly, a Conglomerate and Clay Dataset (CCD) is proposed to study the granularity of the mine dump. A typical study area is selected for field sampling, and the sampled conglomerate and clay is photographed and labeled. In addition, this article proposes a keypoint-based detection algorithm for the conglomerate and clay detection. The algorithm considers the scale variation of conglomerate and clay in orthophoto images and adopts center point detection to avoid the difficulty of localization. On this basis, dense convolution is introduced in feature extraction to reduce the computational redundancy to conduct detection more efficiently. Finally, the corresponding granularity distributions of conglomerate and clay are obtained by geometric calculation in the deep learning-based detection results. The proposed algorithm is validated on the proposed dataset CCD, and the experiments demonstrate the effectiveness of the proposed algorithm and its application to the granularity analysis of mine dump material.
Colorimetric Nanoparticle-Embedded Hydrogels for a Biosensing Platform
Authors: Lee Taeha , Kim Changheon , Kim Jiyeon , Seong Jung Bae , Lee Youngjeon , Roh Seokbeom , Cheong Da Yeon , Lee Wonseok , Park Jinsung , Hong Yoochan , Lee Gyudo
Published: March 2022

Hydrogels containing colorimetric nanoparticles have been used for ion sensing, glucose detection, and microbial metabolite analyses. In particular, the rapid chemical reaction owing to both the hydrogel form of water retention and the sensitive color change of nanoparticles enables the rapid detection of target substances. Despite this advantage, the poor dispersibility of nanoparticles and the mechanical strength of nanoparticle–hydrogel complexes have limited their application. In this study, we demonstrate a milliliter agarose gel containing homogeneously synthesized polyaniline nanoparticles (PAni-NPs), referred to as PAni-NP–hydrogel complexes (PNHCs). To fabricate the optimal PNHC, we tested various pH solvents based on distilled water and phosphate-buffered saline and studied the colorimetric response of the PNHC with thickness. The colorimetric response of the prepared PNHC to the changes in the pH of the solution demonstrated excellent linearity, suggesting the possibility of using PNHC as a pH sensor. In addition, it was verified that the PNHC could detect minute pH changes caused by the cancer cell metabolites without cytotoxicity. Furthermore, the PNHC can be stably maintained outside water for approximately 12 h without deformation, indicating that it can be used as a disposable patch-type wearable biosensing platform.
D-Pinitol—Active Natural Product from Carob with Notable Insulin Regulation
Authors: Azab Abdullatif
Published: March 2022

Carob is one of the major food trees for peoples of the Mediterranean basin, but it has also been traditionally used for medicinal purposes. Carob contains many nutrients and active natural products, and D-Pinitol is clearly one of the most important of these. D-Pinitol has been reported in dozens of scientific publications and its very diverse medicinal properties are still being studied. Presently, more than thirty medicinal activities of D-Pinitol have been reported. Among these, many publications have reported the strong activities of D-Pinitol as a natural antidiabetic and insulin regulator, but also as an active anti-Alzheimer, anticancer, antioxidant, and anti-inflammatory, and is also immune- and hepato-protective. In this review, we will present a brief introduction of the nutritional and medicinal importance of Carob, both traditionally and as found by modern research. In the introduction, we will present Carob’s major active natural products. The structures of inositols will be presented with a brief literature summary of their medicinal activities, with special attention to those inositols in Carob, as well as D-Pinitol’s chemical structure and its medicinal and other properties. D-Pinitol antidiabetic and insulin regulation activities will be extensively presented, including its proposed mechanism of action. Finally, a discussion followed by the conclusions and future vision will summarize this article.
Molecular Detection and Genetic Characterization of Potential Zoonotic Swine Enteric Viruses in Northern China
Authors: Werid Gebremeskel Mamu , Ibrahim Yassein M. , Chen Hongyan , Fu Lizhi , Wang Yue
Published: March 2022

Despite significant economic and public health implications, swine enteric viruses that do not manifest clinical symptoms are often overlooked, and data on their epidemiology and pathogenesis are still scarce. Here, an epidemiological study was carried out by using reverse transcription-polymerase chain reaction (RT-PCR) and sequence analysis in order to better understand the distribution and genetic diversity of porcine astrovirus (PAstV), porcine encephalomyocarditis virus (EMCV), porcine kobuvirus (PKV), and porcine sapovirus (PSaV) in healthy pigs reared under specific pathogen-free (SPF) or conventional farms. PKV was the most prevalent virus (51.1%, 247/483), followed by PAstV (35.4%, 171/483), then PSaV (18.4%, 89/483), and EMCV (8.7%, 42/483). Overall, at least one viral agent was detected in 300 out of 483 samples. Out of the 300 samples, 54.0% (162/300), 13.0% (39/300), or 1.0% (3/300) were found coinfected by two, three, or four viruses, respectively. To our knowledge, this is the first report of EMCV detection from porcine fecal samples in China. Phylogenetic analysis revealed genetically diverse strains of PAstV, PKV, and PSaV circulating in conventional and SPF farms. Detection of swine enteric viruses with a high coinfection rate in healthy pigs highlights the importance of continuous viral surveillance to minimize future economic and public health risks.
Synonymous Codon Pattern of Cowpea Mild Mottle Virus Sheds Light on Its Host Adaptation and Genome Evolution
Authors: Yang Siqi , Liu Ye , Wu Xiaoyun , Cheng Xiaofei , Wu Xiaoxia
Published: March 2022

Cowpea mild mottle virus (CpMMV) is an economically significant virus that causes severe disease on several legume crops. Aside from recombination, other factors driving its rapid evolution are elusive. In this study, the synonymous codon pattern of CpMMV and factors shaping it were analyzed. Phylogeny and nucleotide composition analyses showed that isolates of different geography or hosts had very similar nucleotide compositions. Relative synonymous codon usage (RSCU) and neutrality analyses suggest that CpMMV prefers A/U-ending codons and natural selection is the dominative factor that affects its codon bias. Dinucleotide composition and codon adaptation analyses indicate that the codon pattern of CpMMV is mainly shaped by the requirement of escaping of host dinucleotide-associated antiviral responses and translational efficiency.
Hydrogen Sulfide Promotes Adventitious Root Development in Cucumber under Salt Stress by Enhancing Antioxidant Ability
Authors: Liu Yayu , Wei Lijuan , Feng Li , Zhang Meiling , Hu Dongliang , Tie Jianzhong , Liao Weibiao
Published: March 2022

As a gas signal molecule, hydrogen sulfide (H2S) can enhance plant stress resistance. Here, cucumber (Cucumis sativus ‘Xinchun NO. 4’) explants were used to investigate the role of H2S in adventitious root development under salt stress. The results show that sodium chloride (NaCl) at 10 mM produced moderate salt stress. The 100 µM sodium hydrosulfide (NaHS) treatment, a H2S donor, increased root number and root length by 38.37% and 66.75%, respectively, indicating that H2S effectively promoted the occurrence of adventitious roots in cucumber explants under salt stress. The results show that under salt stress, NaHS treatment reduced free proline content and increased the soluble sugar and soluble protein content during rooting. Meanwhile, NaHS treatment enhanced the activities of antioxidant enzymes [peroxidase (POD), superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT)], increased the content of ascorbic (ASA) and glutathione (GSH), reduced the content of hydrogen peroxide (H2O2) and the rate of superoxide radical (O2−) production, and decreased relative electrical conductivity (REC) and the content of malondialdehyde (MDA). However, the NaHS scavenger hypotaurine (HT) reversed the above effects of NaHS under salt stress. In summary, H2S promoted adventitious root development under salt stress through regulating osmotic substance content and enhancing antioxidant ability in explants.
Responses of Physiology, Photosynthesis, and Related Genes to Saline Stress in Cornus hongkongensis subsp. tonkinensis (W. P. Fang) Q. Y. Xiang
Authors: Yuan Jia-Qiu , Sun Da-Wei , Lu Qiang , Yang Ling , Wang Hao-Wei , Fu Xiang-Xiang
Published: March 2022

Cornus hongkongensis subsp. tonkinensis (W. P. Fang) Q. Y. Xiang is a native evergreen species with high ornamental value for abundant variations in leaf, bract, fruit, and tree gesture. To broaden its cultivation in coastal saline soil, salt damage and survival rate, physiological responses, photosynthetic performance, and related genes were evaluated for annual seedlings exposed to 0.3% salt (ST) concentrations for 60 days. Syndromes of salt damage were aggravated, and the survival rate decreased with prolonged stress duration; all stressed seedlings displayed salt damage, and 58.3% survived. Under short-term saline stress (5 d), marked increases in malondialdehyde (MDA), relative electrical conductivity (REC), and decreases in superoxide dismutase (SOD), photosynthetic rate (Pn), stomatal conductance (gs), and internal carbon dioxide concentration (Ci) were recorded. The stable leaf water use efficiency (WUE) and chlorophyll content were positive physiological responses to ensure photosynthetic performance. Meanwhile, the expression levels of genes related to photosystem II (psbA) and photorespiration (SGAT and GGAT) were upregulated, indicating the role of photorespiration in protecting photosynthesis from photoinhibition. After 30 days of stress (≥30 d), there was a significant increase in MDA, REC, soluble sugar (SS), soluble protein (SP), and Ci, whereas descending patterns in Pn, gs, WUE, the maximal photochemical efficiency of photosystem II (Fv/Fm), and potential activities of PSII (Fv/F0) occurred in salt-stressed seedlings, compared with CK. Meanwhile, the expression levels of related genes significantly dropped, such as psbA, LFNR, GGAT, GLYK, and PGK, indicating photoinhibition and worse photosynthetic performance. Our results suggest that the moderate salt tolerance of C. hongkongensis subsp. tonkinensis mostly lies in a better photosynthetic system influenced by active photorespiration. Hence, these results provide a framework for better understanding the photosynthetic responses of C. hongkongensis subsp. tonkinensis to salt stress.
Nanomicelles of Radium Dichloride [223Ra]RaCl2 Co-Loaded with Radioactive Gold [198Au]Au Nanoparticles for Targeted Alpha–Beta Radionuclide Therapy of Osteosarcoma
Authors: Souza Bárbara Nayane Rosário Fernandes , Ribeiro Elisabete Regina Fernandes Ramos , da Silva de Barros Aline Oliveira , Pijeira Martha Sahylí Ortega , Kenup-Hernandes Hericka Oliveira , Ricci-Junior Eduardo , Diniz Filho Joel Félix Silva , dos Santos Clenilton Costa , Alencar Luciana Magalhães Rebelo , Attia Mohamed F. , Gemini-Piperni Sara , Santos-Oliveira Ralph
Published: March 2022

Alpha and beta particulate radiation are used for non-treated neoplasia, due to their ability to reach and remain in tumor sites. Radium-223 (223Ra), an alpha emitter, promotes localized cytotoxic effects, while radioactive gold (198Au), beta-type energy, reduces radiation in the surrounding tissues. Nanotechnology, including several radioactive nanoparticles, can be safely and effectively used in cancer treatment. In this context, this study aims to analyze the antitumoral effects of [223Ra]Ra nanomicelles co-loaded with radioactive gold nanoparticles ([198Au]AuNPs). For this, we synthesize and characterize nanomicelles, as well as analyze some parameters, such as particle size, radioactivity emission, dynamic light scattering, and microscopic atomic force. [223Ra]Ra nanomicelles co-loaded with [198Au]AuNPs, with simultaneous alpha and beta emission, showed no instability, a mean particle size of 296 nm, and a PDI of 0.201 (±0.096). Furthermore, nanomicelles were tested in an in vitro cytotoxicity assay. We observed a significant increase in tumor cell death using combined alpha and beta therapy in the same formulation, compared with these components used alone. Together, these results show, for the first time, an efficient association between alpha and beta therapies, which could become a promising tool in the control of tumor progression.
Synthesis and Vulcanization of Polymyrcene and Polyfarnesene Bio-Based Rubbers: Influence of the Chemical Structure over the Vulcanization Process and Mechanical Properties
Authors: Banda-Villanueva Arnulfo , González-Zapata José Luis , Martínez-Cartagena Manuel Eduardo , Magaña Ilse , Córdova Teresa , López Ricardo , Valencia Luis , Medina Sergio García , Rodríguez Alejandro Medina , Soriano Florentino , Díaz de León Ramón
Published: March 2022

The overuse of fossil-based resources to produce thermoplastic materials and rubbers is dramatically affecting the environment, reflected in its clearest way as global warming. As a way of reducing this, multiple efforts are being undertaken including the use of more sustainable alternatives, for instance, those of natural origin as the main feedstock alternative, therefore having a lower carbon footprint. Contributing to this goal, the synthesis of bio-based rubbers based on β-myrcene and trans-β-farnesene was addressed in this work. Polymyrcene (PM) and polyfarnesene (PF) were synthesized via coordination polymerization using a neodymium-based catalytic system, and their properties were compared to the conventional polybutadiene (PB) and polyisoprene (PI) also obtained via coordination polymerization. Moreover, different average molecular weights were also tested to elucidate the influence over the materials’ properties. The crosslinking of the rubbers was carried out via conventional and efficient vulcanization routes, comparing the final properties of the crosslinking network of bio-based PM and PF with the conventional fossil-based PB and PI. Though the mechanical properties of the crosslinked rubbers improved as a function of molecular weight, the chemical structure of PM and PF (with 2 and 3 unsaturated double bonds, respectively) produced a crosslinking network with lower mechanical properties than those obtained by PB and PI (with 1 unsaturated double bond). The current work contributes to the understanding of improvements (in terms of crosslinking parameters) that are required to produce competitive rubber with good sustainability/performance balance.
Soft Tissue Hybrid Model for Real-Time Simulations
Authors: Moreno-Guerra Mario R. , Martínez-Romero Oscar , Palacios-Pineda Luis Manuel , Olvera-Trejo Daniel , Diaz-Elizondo José A. , Flores-Villalba Eduardo , da Silva Jorge V. L. , Elías-Zúñiga Alex , Rodriguez Ciro A.
Published: March 2022

In this article, a recent formulation for real-time simulation is developed combining the strain energy density of the Spring Mass Model (SMM) with the equivalent representation of the Strain Energy Density Function (SEDF). The resulting Equivalent Energy Spring Model (EESM) is expected to provide information in real-time about the mechanical response of soft tissue when subjected to uniaxial deformations. The proposed model represents a variation of the SMM and can be used to predict the mechanical behavior of biological tissues not only during loading but also during unloading deformation states. To assess the accuracy achieved by the EESM, experimental data was collected from liver porcine samples via uniaxial loading and unloading tensile tests. Validation of the model through numerical predictions achieved a refresh rate of 31 fps (31.49 ms of computation time for each frame), achieving a coefficient of determination R2 from 93.23% to 99.94% when compared to experimental data. The proposed hybrid formulation to characterize soft tissue mechanical behavior is fast enough for real-time simulation and captures the soft material nonlinear virgin and stress-softened effects with high accuracy.
Recent Strategies for the Immobilization of Therapeutic Enzymes
Authors: Zhu Chen-Yuan , Li Fei-Long , Zhang Ye-Wang , Gupta Rahul K. , Patel Sanjay K. S. , Lee Jung-Kul
Published: March 2022

Therapeutic enzymes play important roles in modern medicine due to their high affinity and specificity. However, it is very expensive to use them in clinical medicine because of their low stability and bioavailability. To improve the stability and effectiveness of therapeutic enzymes, immobilization techniques have been employed to enhance the applications of therapeutic enzymes in the past few years. Reported immobilization techniques include entrapment, adsorption, and covalent attachment. In addition, protein engineering is often used to improve enzyme properties; however, all methods present certain advantages and limitations. For carrier-bound immobilization, the delivery and release of the immobilized enzyme depend on the properties of the carrier and enzyme. In this review, we summarize the advantages and challenges of the current strategies developed to deliver therapeutic enzymes and provide a future perspective on the immobilization technologies used for therapeutic enzyme delivery.
Energy Release Characteristics and Reaction Mechanism of PTFE/Al/Bi2O3 Reactive Materials under Drop-Hammer Test
Authors: Jiang Chunlan , Hu Rong , Mao Liang , Wang Zaicheng , Xu Wenyu , Hu Wanxiang
Published: March 2022

To obtain the influence of the Bi2O3 particle content of a PTFE/Al/Bi2O3 reactive material (later referred to as PAB) on its shock-induced chemical reaction (SICR) characteristics, five kinds of PAB with different Bi2O3 contents were prepared; the reaction process in a drop-hammer test, recorded using a high-speed camera, was analyzed. The ignition and reaction mechanisms of PAB under mechanical impact were analyzed based on the thermochemical reaction characteristics and the microstructure. The results show that with an increase in Bi2O3 content, the shock-induced chemical reaction duration and the sensitivity of PAB increase, and then decrease. When the Bi2O3 content is 9%, the impact sensitivity is the highest and the reaction duration is the longest. The heating at the crack tip is responsible for PAB ignition under long-pulse low-velocity impact. During ignition, PAB undergoes several physicochemical changes such as the melting of PTFE, a PTFE/Bi2O3 reaction, an Al/Bi2O3 reaction, pyrolysis of the melted PTFE, and a C2F4/Al reaction; moreover, the presence of Bi2O3 decreases the excitation threshold of the reactive material, which facilitates the propagation of the reaction and improves the degree of the reaction and overall energy release of the reactive material.
Flexural Behavior on Damaged Steel Beams Strengthened with CFRP Sheets Subjected to Overloading
Authors: Hou Wenyu , Huang Fulong , Zhang Kexin
Published: March 2022

This paper presents results of testing and numerical analyses of damaged steel beams strengthened with carbon-fiber reinforced polymer (CFRP) sheet and subjected to overloading. The test results showed that as cyclic times increase, the yield load and stiffness increase, but the ultimate bearing capacity decreases to a certain extent. Applying prestress could improve the ductility of the girder. The damage level greatly influenced the girders with overloading, and the increase in damage degree reduced the stiffness, yield load and ultimate load. The numerical calculation showed that the yield load would decrease by 0.4–0.8 kN when the cyclic times increase by 100 times. The yield load would increase by 1–2 kN and the ultimate bearing capacity would decrease by 0.6–1.2 kN when the overloading amplitude increased by 0.02 Pu. The increase in damage degree would obviously reduce the yield load and ultimate bearing capacity of the steel beam after overloading. The yield load and ultimate bearing capacity could be increased by approximately 3 kN when the CFRP sheet thickness increases by 0.05 mm.
The Effect of Spray Parameters on the Survival of Bacteriophages
Authors: Wessels Kirsten , Rip Diane , Gouws Pieter
Published: March 2022

There have been numerous studies highlighting the efficacy of various bacteriophages (phages) and phage cocktails in the reduction of pathogens in food. Despite approval from legislative bodies permitting phage use in food processing environments, applied via spray or dip, there is still no information on which spray parameters should be used for successful implementation. The study here investigates phage survival diluted to 1% in distilled water (dH2O) and prepared bottled water (PBW), followed by a subsequent spray application through a fixed nozzle (530 μm) and strainer size (74 × 74 μm), with pressures of 3, 5, and 6 Bar. The survival of the phage was determined through sampling the outputs of the spray system and performing double agar overlay plaque assays. PBW decreased the phage concentration (p = 0.18) more than the dH2O (p = 0.73) prior to spray application. It was found that the PBW phage solution was less affected by the various spray parameters (p = 0.045) than the dH2O (p = 0.011). The study showed that unchlorinated water (dH2O), as well as a pressure of 3 Bar, had the highest output phage concentration through the nozzle and strainer, providing valuable information for industrial implementation.
Modeling and Optimization of the Flue Gas Heat Recovery of a Marine Dual-Fuel Engine Based on RSM and GA
Authors: Meng Deyu , Gan Huibing , Wang Huaiyu
Published: March 2022

Implementation of flue gas waste heat recovery is an effective way to improve the energy utilization of marine engines. This paper aims to model and optimize a marine four-stroke dual-fuel (DF) engine coupled with a flue gas waste heat recovery system. Firstly, the DF engine and waste heat recovery system were respectively modeled in GT-Power and Simulink environments and verified with experimental data. Then, a regression model was built using the response surface method, with the intake temperature, compression ratio, and pilot fuel injection timing as input parameters and parametric analysis was performed. Finally, multi-objective optimization of the waste heat recovery system was performed using a genetic algorithm. The result showed that the optimal solution is obtained when the intake temperature is 306.18 K, the geometric compression ratio is 14.4, and the pilot fuel injection timing is −16.68 °CA after the top dead center. The corresponding brake-specific fuel consumption was 155.18 g/kWh, reduced by 3.24%, and the power was 8025.62 kW, increased by 0.32%. At the same time, 280.98 kW of flue gas waste heat generation was obtained.
Non-Invasive Muscular Atrophy Causes Evaluation for Limb Fracture Based on Flexible Surface Electromyography System
Authors: Pei Xiachuan , Yan Ruijian , Jiang Guangyao , Qi Tianyu , Jin Hao , Dong Shurong , Feng Gang
Published: March 2022

Muscular atrophy after limb fracture is a frequently occurring complication with multiple causes. Different treatments and targeted rehabilitation procedures should be carried out based on the causes. However, bedside evaluation methods are invasive in clinical practice nowadays, lacking reliable non-invasive methods. In this study, we propose a non-invasive flexible surface electromyography system with machine learning algorithms to distinguish nerve-injury and limb immobilization-related atrophy. First, a flexible surface electromyography sensor was designed and verified by in vitro tests for its robustness and flexibility. Then, in vivo tests on rats proved the reliability compared with the traditional invasive diagnosis method. Finally, this system was applied for the diagnosis of muscular atrophy in 10 patients. The flexible surface electromyography sensor can achieve a max strain of 12.0%, which ensures close contact with the skin. The in vivo tests on rats show great comparability with the traditional invasive diagnosis method. It can achieve a high specificity of 95.28% and sensitivity of 98.98%. Application on patients reaches a relatively high specificity of 89.44% and sensitivity of 91.94%. The proposed painless surface electromyography system can be an easy and accurate supplementary for bedside muscular atrophy causes evaluation, holding excellent contact with the body.
Visual Sensor Networks for Indoor Real-Time Surveillance and Tracking of Multiple Targets
Authors: Giordano Jacopo , Lazzaretto Margherita , Michieletto Giulia , Cenedese Angelo
Published: March 2022

The recent trend toward the development of IoT architectures has entailed the transformation of the standard camera networks into smart multi-device systems capable of acquiring, elaborating, and exchanging data and, often, dynamically adapting to the environment. Along this line, this work proposes a novel distributed solution that guarantees the real-time monitoring of 3D indoor structured areas and also the tracking of multiple targets, by employing a heterogeneous visual sensor network composed of both fixed and Pan-Tilt-Zoom (PTZ) cameras. The fulfillment of the twofold mentioned goal was ensured through the implementation of a distributed game-theory-based algorithm, aiming at optimizing the controllable parameters of the PTZ devices. The proposed solution is able to deal with the possible conflicting requirements of high tracking precision and maximum coverage of the surveilled area. Extensive numerical simulations in realistic scenarios validated the effectiveness of the outlined strategy.
A Systematic Literature Review on Distributed Machine Learning in Edge Computing
Authors: Filho Carlos Poncinelli , Marques Elias , Chang Victor , dos Santos Leonardo , Bernardini Flavia , Pires Paulo F. , Ochi Luiz , Delicato Flavia C.
Published: March 2022

Distributed edge intelligence is a disruptive research area that enables the execution of machine learning and deep learning (ML/DL) algorithms close to where data are generated. Since edge devices are more limited and heterogeneous than typical cloud devices, many hindrances have to be overcome to fully extract the potential benefits of such an approach (such as data-in-motion analytics). In this paper, we investigate the challenges of running ML/DL on edge devices in a distributed way, paying special attention to how techniques are adapted or designed to execute on these restricted devices. The techniques under discussion pervade the processes of caching, training, inference, and offloading on edge devices. We also explore the benefits and drawbacks of these strategies.
Sensors Allocation and Observer Design for Discrete Bilateral Teleoperation Systems with Multi-Rate Sampling
Authors: Ghavifekr Amir Aminzadeh , De Fazio Roberto , Velazquez Ramiro , Visconti Paolo
Published: March 2022

This study addresses sensor allocation by analyzing exponential stability for discrete-time teleoperation systems. Previous studies mostly concentrate on the continuous-time teleoperation systems and neglect the management of significant practical phenomena, such as data-swap, the effect of sampling rates of samplers, and refresh rates of actuators on the system’s stability. A multi-rate sampling approach is proposed in this study, given the isolation of the master and slave robots in teleoperation systems which may have different hardware restrictions. This architecture collects data through numerous sensors with various sampling rates, assuming that a continuous-time controller stabilizes a linear teleoperation system. The aim is to assign each position and velocity signals to sensors with different sampling rates and divide the state vector between sensors to guarantee the stability of the resulting multi-rate sampled-data teleoperation system. Sufficient Krasovskii-based conditions will be provided to preserve the exponential stability of the system. This problem will be transformed into a mixed-integer program with LMIs (linear matrix inequalities). These conditions are also used to design the observers for the multi-rate teleoperation systems whose estimation errors converge exponentially to the origin. The results are validated by numerical simulations which are useful in designing sensor networks for teleoperation systems.