bluuebunny/crossref_metadata_2025 huggingface dataset:
Diachronic Mapping of Soil Organic Matter in Eastern Croatia Croplands
Authors: Trevisani Sebastiano , Bogunovic Igor
Published: June 2022

The spatiotemporal analysis and mapping of soil organic matter (SOM) play a pivotal role for evaluating soil health and for implementing preservation and restoration actions. In this context, the first aim of the study is to furnish a high-resolution mapping of current SOM content in eastern Croatia. The second aim is to perform a diachronic analysis of SOM content, comparing two datasets characterized by an extreme data imbalance. The more recent dataset (SOM2010), representative of 2010s, comprises 19,386 samples and the older dataset (SOM1970), representative of the 1970s, comprises 152 samples. The marked data imbalance and the different modalities in soil sampling and laboratory analysis of the two datasets are taken into consideration in performing the comparison. The study reveals a general depletion trend of SOM from the 1970s to the 2010s, more evident in with regard to Fluvisols and Gleysols. At a regional scale, the SOM2010 is characterized by lower variability compared to SOM1970, indicating a process of homogenization of SOM spatial distribution in recent years. Considering the local scale, there is limited information for the 1970s; for the 2010s the SOM spatial distribution is characterized by a high short-range spatial variability, with a characteristic spotty appearance, likely related to agricultural practices.
Transforming the Use of Agricultural Premises under Urbanization Pressures: A Story from a Second-Tier Post-Socialist City
Authors: Klusáček Petr , Martinát Stanislav , Charvátová Klára , Navrátil Josef
Published: June 2022

Diverse aspects of de-agrarianization, which is manifested by the cessation or significant reduction in agricultural activities, have been clearly visible at the outskirts of large cities in Central Europe in recent decades. The key drivers behind this process include increased pressures to cover peri-urban agricultural land by new developments, inadequate protection of agricultural land, ineffective implementation of urban planning policies, low recognition of the importance of agriculture, and overall changes in people’s dietary habits. Urbanization pressures undoubtedly belong to the factors intensifying overall de-agrarianization, as urban farmers are usually not able to compete with other urban functions. This article focuses on more in-depth understanding of the driving forces behind de-agrarianization processes that are specific to post-socialist cities. As a case study, Brno, a second-tier city in the Czech Republic, was selected. In the first part, the conceptual framework and drivers of de-agrarianization are discussed specifically for the case of large Central European post-socialist cities. In the next part, we explore by means of a set of qualitative interviews the case study of the regeneration of the area of a former Cistercian monastery in Brno that was traditionally used for agricultural purposes, but recently was redeveloped for a university campus. Our findings signal procedural issues connected to the preservation of architectural heritage during the regeneration that frequently end up with only fragments being preserved. We also demonstrate a decline in the use of urban agricultural properties that are hastily transformed into a new urban environment under extremely strong urbanization pressures. We argue that even in economically prosperous cities with highly neoliberal competition between possible urban land uses, agriculture must be considered a relevant and highly important urban function and more protected by planning tools.
Land Use Change and Ecosystem Health Assessment on Shanghai–Hangzhou Bay, Eastern China
Authors: Xu Dan , Cai Zhuang , Xu Di , Lin Wenpeng , Gao Jun , Li Lubing
Published: June 2022

Reasonable quantitative assessment on urban ecosystem health is conducive to the sustainable development of the economy and human society. This paper quantitatively evaluated the impact of land use change on ecosystem services and ecosystem health by building a comprehensive evaluation system (vigor–organization–resilience–ecosystem services), and then analyzed the spatial-temporal pattern, evolution characteristics, and driving factors in the Shanghai–Hangzhou Bay area (SHB) over the 2000–2015 period. The results show that: the area of cropland and forest accounted for more than 65% and was mainly converted into built-up land in the past 15 years. The overall ESV showed a trend of first increasing and then decreasing. Forest accounted for the largest proportion of the total ESV, more than 60% in each year. The ecosystem health value of SBH decreased from 2000 to 2015. At the city scale, the ecosystem health was significantly deteriorated. All cities reached the lowest value by 2015. At the districts/counties scale, the number with the relatively well or well level decreased from 32 in 2000 to 20 in 2015 by 24.64% of the total area. Overall, inland regions of SBH had better ecosystem health situation than coastal areas. The rapid urbanization of population and economy were driving factors for the decline of the ecosystem health. The indicator system of integrating the vigor, organization, resilience, and ecosystem service for ecosystem health assessment is a potential method which could provide a quantitative and comprehensive way for evaluating ecological and environmental effects in the future.
Study on the Evolution, Driving Factors, and Regional Comparison of Innovation Patterns in the Yangtze River Delta
Authors: Yan Dongsheng , Sun Wei
Published: June 2022

The differences in innovation, and the resulting inefficient allocation of innovation resources, are key factors affecting the high-quality development of urban agglomerations. In the context of China’s upgrading of the integrated development of the Yangtze River Delta (YRD) to a national strategy, the study of innovation patterns and driving factors in this highly developed urban agglomeration provide references and experiences for high-quality development and innovation improvements in other urban agglomerations. Using prefecture-level patent data from 2000 to 2018, this study analyses the evolution characteristics of the innovation patterns in the YRD, from the perspective of innovation level and innovation growth, based on the coefficient of variation, locational Gini coefficient, and the relative development rate index. Then, using the knowledge production function, this study quantitatively explores the driving factors for innovation from multiple perspectives. The main findings are as follows. The differences in urban innovation levels decrease with improvements in the innovation level of urban agglomerations. In terms of the evolution of the spatial pattern of innovation levels, the “core–periphery” and “south–north” differences are highly stable; however, the innovation levels of some peripherical cities improve. The growth of urban innovation levels show significant regional differences, with fast-growing cities clustered in the core area, and high-value areas characterized by proximity diffusion. Based on the innovation level in different periods, cities are divided into low–low, low–high, high–low, and high–high types. There are spatio–temporal differences in the driving factors for innovation. On the one hand, different periods show an intensification of factor inputs and external linkage effects, as well as the differentiation of urban development state effects. On the other hand, there are differences among different types of cities, with low–low cities mainly driven by factor inputs, urban development state, and internal opening-up; low–high and high–high cities are greatly influenced by factor inputs and urban development state. By expanding on existing studies, the present research provides a refined reference for the formulation of scientific policies aimed at promoting innovation development in China.
Conflict or Coordination? Analysis of Spatio-Temporal Coupling Relationship between Urbanization and Eco-Efficiency: A Case Study of Urban Agglomerations in the Yellow River Basin, China
Authors: Ren Yuhan , Bai Yuping , Liu Yihan , Wang Jiale , Zhang Fan , Wang Zheng
Published: June 2022

The coordination and coupling of new urbanization and the ecological environment is of great significance for the high-quality development of the Yellow River basin, China. In this paper, the urbanization efficiency and ecological efficiency of seven urban agglomerations in the Yellow River basin, China, from 2006 to 2019 are calculated at the city level. Spatial correlation analysis between urbanization efficiency and ecological efficiency is carried out by applying the spatial association model. Then, the spatio-temporal coupling relationship is estimated based on the relative development and spatial coupling models. The results show that urbanization efficiency has been rising, from 0.83 in 2006 to 0.91 in 2019. Ecological efficiency first stabilized and then rose from 1.03 in 2006 to 1.23 in 2019. Spatially, cities with high urbanization efficiency development are increasing from west to east. Cities with high eco-efficient developments are increasing from northwest to southeast. The coupling relationship between the two is an N-type relationship, with the trend of first rising, then falling, and then rising. Spatially, the coupling degree of the upper and lower reaches of the Yellow River basin, China, is higher than that of the middle reaches of the Yellow River basin, China. Finally, this paper puts forward policy recommendations on the coordinated and coupling development of urban agglomerations in the Yellow River basin, China, from the perspective of the future differentiated development of different urban agglomerations.
Jeg Gotta Like Spille Fortnite, Men I Never Win the Game: Implementing Multilingual Pedagogies in a Norwegian Primary School
Authors: Schipor Delia
Published: June 2022

Teachers in Norway have been increasingly faced with the challenge of adapting their instruction methods to address the needs of minority-language students. The current body of research on the issue seems to indicate that multilingual practices are being introduced in Norwegian classrooms. However, they often rely on majority languages, such as English and Norwegian. Some teachers have been found to employ minority languages to support learners’ English writing in drafts. As a result, minority languages in Norwegian schools tend to be regarded as less valuable than Norwegian and English. However, more recent projects are being implemented in Norwegian schools to help teachers alter their ideologies of minority languages. This article adds to this body of research by presenting two teachers’ work with multilingual pedagogies, involving the active use of minority languages alongside Norwegian and English in student texts. The data were collected from: teacher reports, student materials, and mentorship meetings. The findings indicate that the teachers successfully implemented multilingual pedagogies by using language portraits, parallel translanguaging in multilingual posters and multimodal dictionaries, and complementary translanguaging in multilingual poetry. These multilingual practices enabled the students to showcase their linguistic identities and multilingual literacy practices. The implementation of multilingual pedagogies benefited from the long-term availability of scholarly input and guidance for teachers and the opportunity to share experiences in a professional network.
Validation of AmpliSeq NGS Panel for BRCA1 and BRCA2 Variant Detection in Canine Formalin-Fixed Paraffin-Embedded Mammary Tumors
Authors: Di Giacomo Daniela , Di Domenico Marco , Defourny Sabrina , Malatesta Daniela , Di Teodoro Giovanni , Martino Michele , Viola Antonello , D’Alterio Nicola , Cammà Cesare , Modesto Paola , Petrini Antonio
Published: June 2022

Mammary carcinomas are the most common neoplasms observed in women and in female dogs. Canine mammary tumors show epidemiological, clinical, genetic, and prognostic characteristics comparable to human breast cancers. The recent introduction of next generation sequencing (NGS) technologies has greatly improved research and diagnostics for humans, while these new tools still need to be implemented in animal models. In this study we developed and validated an AmpliSeq Panel assay for the identification of BRCA variants in twenty-two different dogs. The amplicon mean coverage was 5499× and uniformity was higher than 98% in all samples. The results of germline single nucleotide variants (SNVs) and insertions/deletions (INDELs) were fully concordant regardless of the types of samples considered (blood, fresh and FFPE tissues). Moreover, despite the high DNA degradation observed in older FFPE blocks (>5 years), the assay allowed full coverage of all amplicons for downstream analyses. We consider the NGS panel developed in this study as a useful tool for expanding information on BRCA genes in the veterinary field and for human health from a comparative oncology perspective.
Modification of 1-Hexene Vinylidene Dimer into Primary and Tertiary Alkanethiols
Authors: Kovyazin Pavel V. , Bikmeeva Almira Kh. , Palatov Eldar R. , Parfenova Lyudmila V.
Published: June 2022

Aliphatic thiols are in high demand in materials chemistry. Herein, a synthesis of thio-derivatives of 1-hexene vinylidene dimer is described. The approach, based on a hydroalumination reaction with further replacement of the organoaluminum function with sulfur using thiourea or dimethyl disulfide, provides anti-Markovnikov products, 2-butyloctane-1-thiol or 5-(methylsulfanylmethyl)undecane, in moderate yields. The reaction of a vinylidene dimer with phosphorus pentasulfide in the presence of catalytic amounts of (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) selectively gives the Markovnikov product, 5-methylundecane-5-thiol, with a yield of up to 77%.
2-((4-Phenyl-5-(2-(p-tolylamino)ethyl)-4H-1,2,4-triazol-3-yl)thio)-N′-(1-phenylethylidene)acetohydrazide
Authors: Šermukšnytė Aida , Jonuškienė Ilona , Kantminienė Kristina , Beresnevičius Zigmuntas Jonas , Tumosienė Ingrida
Published: June 2022

A synthesis of 2-((4-phenyl-5-(2-(p-tolylamino)ethyl)-4H-1,2,4-triazol-3-yl)thio)-N’-(1-phenylethylidene)acetohydrazide from 2-[(3-{2-[(4-methylphenyl)amino]ethyl}-4-phenyl-4,5-dihydro-1H-1,2,4-triazol-5-yl)sulfanyl]acetohydrazide and acetophenone is reported. The title compound has been tested to possess 1.5-fold higher antioxidant ability than the control, butylated hydroxytoluene, as determined by a Ferric reducing antioxidant power assay.
Adsorption of Rhodamine B from Simulated Waste Water onto Kaolin-Bentonite Composites
Authors: He Haijie , Chai Kuan , Wu Tao , Qiu Zhanhong , Wang Shifang , Hong Jie
Published: June 2022

Organic dye rhodamine B is one of the common organic pollutants in the water and soil environment. This study investigated the feasibility of removing rhodamine B from an aqueous solution through adsorption by kaolin, kaolin-sodium bentonite, and kaolin-organic bentonite. Batch adsorption test results showed that the maximum adsorption quantities of kaolin, kaolin-sodium bentonite, and kaolin-organic bentonite were 7.76 mg/g, 11.26 mg/g, and 12.68 mg/g, respectively, implying that the addition of bentonite to kaolin can effectively improve its adsorption capacity for rhodamine B. Moreover, the Langmuir isotherm model is suitable to describe the adsorption of rhodamine B by kaolin and kaolin-sodium bentonite, while it is preferable to use the Freundlich isotherm model in the case of kaolin-organic bentonite. The adsorption kinetic characteristics of rhodamine B, by these three adsorbents, are suitable to be described with a pseudo-second order kinetic model. Furthermore, the characteristics of the above three adsorbents were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The above results indicated that kaolin and organic bentonite can be used to design efficient adsorbents for organic pollutants similar to rhodamine B.
General Procedure for Servo-Axis Design in Multi-Degree-of-Freedom Machinery Subject to Mixed Loads
Authors: Righettini Paolo , Strada Roberto , Cortinovis Filippo
Published: June 2022

The motion performances of multi-axis machinery are strongly related to the proper design of the servo axes driving the actuated joints, which must fulfil motion requests in terms of speed and torque for the motion design task. Multi-degree-of-freedom machinery highlights, at the joint level, mixed-load conditions due to high dynamic movements and external working forces. Moreover, such systems have a dynamic coupling between the axes due to their mechanical configuration. This mixed-load condition makes the servo-axes design, whose result is the selection of the couple power drive system and transmission, not a trivial procedure. This paper proposes an extensive theoretical discussion that leads to a general procedure for the direct design of the servo axes of multi-degree-of-freedom machinery subject to a mixed-load condition and dynamic coupling between the mechanical joints. The proposed procedure starts with identifying the loads required on the actuated joints without distinguishing between the different contributions. Then, in a few steps, the methodology leads to the direct choice of the PDS/transmission units through a single graphical representation where the load’s peak, thermal and speed conditions are highlighted, along with the possible PDSs and transmissions. The graphical representation proposed also allows the easy and efficient analysis of the effect of transmission selection on the torque and speed margins. Finally, the paper presents the effectiveness of the proposed procedure, applied to the design of the servo axes of a linear delta robot.
Robust Image Matching Based on Image Feature and Depth Information Fusion
Authors: Yan Zhiqiang , Wang Hongyuan , Ning Qianhao , Lu Yinxi
Published: June 2022

In this paper, we propose a robust image feature extraction and fusion method to effectively fuse image feature and depth information and improve the registration accuracy of RGB-D images. The proposed method directly splices the image feature point descriptors with the corresponding point cloud feature descriptors to obtain the fusion descriptor of the feature points. The fusion feature descriptor is constructed based on the SIFT, SURF, and ORB feature descriptors and the PFH and FPFH point cloud feature descriptors. Furthermore, the registration performance based on fusion features is tested through the RGB-D datasets of YCB and KITTI. ORBPFH reduces the false-matching rate by 4.66~16.66%, and ORBFPFH reduces the false-matching rate by 9~20%. The experimental results show that the RGB-D robust feature extraction and fusion method proposed in this paper is suitable for the fusion of ORB with PFH and FPFH, which can improve feature representation and registration, representing a novel approach for RGB-D image matching.
An AI-Based Fast Design Method for New Centrifugal Compressor Families
Authors: Bicchi Marco , Biliotti Davide , Marconcini Michele , Toni Lorenzo , Cangioli Francesco , Arnone Andrea
Published: June 2022

Limiting global warming’s effects requires a sudden reduction of greenhouse gas emissions to pursue a net-zero carbon growth in the next decades. Along with this energy transition, drastic and rapid changes in demand are expected in many sectors, including the one for centrifugal compressors. In this context, new aerodynamic design processes exploiting the know-how of existing impeller families to generate novel centrifugal compressors could quickly react to demand variations and ensure companies’ success. Modifying the characteristics of existing compressors using a 1D single-zone model is a fast way to exploit this know-how. Besides, artificial intelligence could be useful to highlight relationships between geometrical parameters and performance, thus facilitating the achievement of optimized machines for new applications. Although the scientific literature shows several studies on mono-dimensional approaches, the joint use of a 1D single-zone model with an artificial neural network for designing new impellers from pre-engineered ones remains understudied. Such a model was provided in this paper. An application to the case study of an expander–compressor impeller family derived from other existing natural gas liquefaction one was presented. Results proved that the proposed model enabled developing a new family from an existing one, improving the performance while containing design time and computational efforts.
Design of a Piezoelectric Pump Driven by Inertial Force of Vibrator Supported by a Slotted Beam
Authors: Zhang Yong , Wang Xiaoliang , Liu Shanlin , Pan Qiaosheng
Published: June 2022

This paper introduces the design, manufacture, dynamic analysis, and experimental results of a piezoelectric pump driven by the inertial force of a vibrator supported by a slotted beam. The piezoelectric vibrator is composed of a mass block, displacement amplifier, and slotted beam fixed with both ends. In the resonant mode, the displacement amplifier drives the slotted beam to work, and produces amplitude and inertial force. In this paper, the design of the slotted beam optimizes the output of the displacement amplifier. In addition, the slotted beam supports the displacement amplifier and increases the elastic output. The pump body adopts polydimethylsiloxane (PDMS) check valves and compressible spaces to improve the output performance. This research studies the influence of stiffness and mass on the output performance by qualitatively analyzing the inertial output force of the vibrator. Nine kinds of slotted beams with different stiffnesses and different mass blocks are designed for comparison. Thereafter, an optimal structure of the piezoelectric pump is selected. The experimental results show that under a driving voltage of 700 Vpp , the maximum flowrate is 441 mL min−1 and the maximum back pressure is 25.3 kPa.
Rotor Strength Analysis of FeCo-Based Permanent Magnet High Speed Motor
Authors: Hou Peng , Ge Baojun , Tao Dajun , Pan Bo , Wang Yue
Published: June 2022

To solve the problem of tension stress caused by centrifugal force and caused by high-speed operation of permanent magnet (PM) rotor, a FeCo-based PM rotor structure model is proposed. Based on the thick-walled cylinder theory, the uniform analytical calculation formulas of strain field, displacement field, and stress field of high-speed permanent magnet rotor are derived, and the stresses of FeCo-based PM and sleeve are obtained. The correctness of analytical calculation method (ACM) is verified by finite element method (FEM). Based on the derived analytical formula, the influence of static interference, sleeve thickness, rotating shaft, and PM thermal expansion coefficient on the strength of high-speed permanent magnet rotor is analyzed, and the mechanical design law of high-speed permanent magnet rotor is summarized. Alloy sleeves are usually fitted outside the high-speed permanent magnet rotor to protect the PM from damage. In order to ensure safe operation of PM rotor under hot rotating conditions, strength calculation and check of sleeve and PM must be carried out. Based on the characteristics of slender structure of high-speed rotor, a high-speed permanent magnet motor (HSPMM) with a rated power of 100 kW and a rated speed of 18,000 r/min was produced, and a continuous operation test was carried out to verify the validity of the above theoretical analysis.
Stability and Dynamic Walk Control of Humanoid Robot for Robot Soccer Player
Authors: Jánoš Rudolf , Sukop Marek , Semjon Ján , Tuleja Peter , Marcinko Peter , Kočan Martin , Grytsiv Maksym , Vagaš Marek , Miková Ľubica , Kelemenová Tatiana
Published: June 2022

Robotic football with humanoid robots is a multidisciplinary field connecting several scientific fields. A challenging task in the design of a humanoid robot for the AndroSot and HuroCup competitions is the realization of movement on the field. This study aims to determine a walking pattern for a humanoid robot with an impact on its dynamic stability and behavior. The design of the proposed technical concept depends on its stability management mechanism, walking speed and such factors as the chosen stability approaches. The humanoid robot and its versatility, along with the adaptability of the terrain, are somewhat limited due to the complexity of the walking principle and the control of the robot’s movement itself. The technical concept uses dynamic stability as the potential force of the inertial bodies and their parts so that the humanoid robot does not overturn. The total height of the robot according to the rules of the competition will be 50 cm. In the performed experiment, only the lower part of the humanoid robot with added weight was considered, which is more demanding due to the non-use of the upper limbs for stabilization. The performed experiment verified the correctness of the design, where the torso of the robot performed eight steps in inclinations of a roll angle +4/−2° and a pitch angle +4/−6°.
Fractal Model of Contact Thermal Stiffness
Authors: Chen Yunshuai , Li Pengyang , Sun Jian , Shang Miao , Shao Limin
Published: June 2022

The continuity, self-similarity, and self-affinity of a microscopic contact surface can be described by the Weierstrass–Mandelbrot (W–M) function in fractal theory. To address the problems that the existing normal contact load fractal model does not take into account the effect of thermal stress and is not applicable to the temperature variation in the joint surface of the giant magnetostrictive ultrasonic vibration systems, a fractal model of thermal–elastic–plastic contact normal load fractal is established based on fractal theory. The model is an extension of the traditional model in terms of basic theory and application scope, and it takes into account the effects of temperature difference, linear expansion coefficient, fractal dimension, and other parameters. Finally, the effect of the temperature difference at the joint surface on the normal load of the thermoelastic contact is revealed through numerical simulations. The results show that the nonlinearity of the contact stiffness of the thermoelastic joint surface is mainly related to the surface roughness and the fractal dimension, while the effect of the temperature change on the joint surface properties within a certain range is linear.
Influence of a Constant Perpendicular High Magnetic Field on the Electrodeposition of Calcium Phosphate Coating
Authors: Daltin Anne-Lise , Chopart Jean-Paul
Published: June 2022

Calcium phosphate coatings were formed on a Ti6Al4V substrate by electrodeposition under a high magnetic field up to 16 T. The magnetic field was parallelly applied to the vertical surface electrode. Changes in crystal morphology of calcium phosphates were investigated as a function of the magnetic field amplitude, and the results are discussed in terms of magnetic field effects. Magnetohydrodynamic convection due to the Lorentz force could considerably reduce the formation of volcano-like structures and generate more uniform deposits without changing Ca/P ratios.
Quality Criteria and Method of Synthesis for Adversarial Attack-Resistant Classifiers
Authors: Gurina Anastasia , Eliseev Vladimir
Published: June 2022

The actual problem of adversarial attacks on classifiers, mainly implemented using deep neural networks, is considered. This problem is analyzed with a generalization to the case of any classifiers synthesized by machine learning methods. The imperfection of generally accepted criteria for assessing the quality of classifiers, including those used to confirm the effectiveness of protection measures against adversarial attacks, is noted. The reason for the appearance of adversarial examples and other errors of classifiers based on machine learning is investigated. A method for modeling adversarial attacks with a demonstration of the main effects observed during the attack is proposed. It is noted that it is necessary to develop quality criteria for classifiers in terms of potential susceptibility to adversarial attacks. To assess resistance to adversarial attacks, it is proposed to use the multidimensional EDCAP criterion (Excess, Deficit, Coating, Approx, Pref). We also propose a method for synthesizing a new EnAE (Ensemble of Auto-Encoders) multiclass classifier based on an ensemble of quality-controlled one-class classifiers according to EDCAP criteria. The EnAE classification algorithm implements a hard voting approach and can detect anomalous inputs. The proposed criterion, synthesis method and classifier are tested on several data sets with a medium dimension of the feature space.
Unsteady Separated Stagnation-Point Flow Past a Moving Plate with Suction Effect in Hybrid Nanofluid
Authors: Zainal Nurul Amira , Nazar Roslinda , Naganthran Kohilavani , Pop Ioan
Published: June 2022

Previous research has shown that incorporating stagnation-point flow in diverse manufacturing industries is beneficial due to its importance in thermal potency. Consequently, this research investigates the thermophysical properties of the unsteady separated stagnation-point flow past a moving plate by utilising a dual-type nanoparticle, namely a hybrid nanofluid. The impact of suction imposition on the entire hydrodynamic flow and heat transfer as well as the growth of boundary layers was also taken into account. A new mathematical hybrid nanofluid model is developed, and similarity solutions are obtained in the form of ordinary differential equations (ODEs). The bvp4c approach in MATLAB determines the reduced ODEs estimated solutions. The results show that increasing the stagnation strength parameters expands the skin friction coefficient and heat transfer rate. The addition of the suction parameter also resulted in an augmentation of thermal conductivity. Interestingly, reducing the unsteadiness parameter proportionately promotes heat-transfer performance. This significant involvement is noticeable in advancing industrial development, specifically in the manufacturing industries and operations systems.
Sliding Mode Control of Manipulator Based on Improved Reaching Law and Sliding Surface
Authors: Ji Peng , Li Chenglong , Ma Fengying
Published: June 2022

Aiming at the problem of convergence speed and chattering in sliding mode variable structure control of manipulator, an improved exponential reaching law and nonlinear sliding surface are proposed, and the Lyapunov function is used to analyze its stability. According to the dynamic model of the 6-DOF UR5 manipulator and the proposed reaching law and sliding surface, the corresponding control scheme is designed. The control performance of the proposed control scheme is verified by tracking the end trajectory of the manipulator on the MATLAB and CoppeliaSim robot simulation platform. The experimental results show that the proposed control scheme can not only significantly improve the convergence speed and make the system converge quickly, but also can effectively reduce the chattering of the system. Even in the presence of disturbance signals, fast and stable tracking can be achieved while ensuring the robustness of the system, and the chattering of the robotic arm system can be weakened to a certain extent. Compared with the classical control method based on the computational torque method and the traditional sliding mode control scheme based on the exponential reaching law, the proposed scheme has certain advantages in terms of tracking accuracy, convergence speed, and reducing system chattering, and effectively improves the overall control performance of the system.
Photoinduced Synthesis of Methylated Marine Cyclopeptide Galaxamide Analogs with Isoindolinone as Anticancer Agents
Authors: Xiao Shimei , Wang Zhiqiang , Zhang Huanli , Zhao Lei , Chang Qingran , Zhang Xiong , Yan Rui , Wu Xiaodan , Jin Yingxue
Published: June 2022

The methylation of amino acid residues has played an important role in the biological function of bioactive peptides. In this paper, various methyl-modified and stereostructural-modified marine cyclopeptide galaxamide analogs with isoindolinone were synthesized by a photoinduced single electron transfer cyclization reaction. It was found that the single-methyl substitution was beneficial for the bioactivity of cyclic analogs with isoindolinone fragments, and the influence of methylation on bioactivity is uncertain and is sometimes case-specific. The compound with a single methyl group at Gly5 (compound 8) showed the strongest antiproliferative activity against HepG-2 cells. The tumor cell apoptosis, cell cycle, mitochondrial membrane potential, intracellular Ca2+ concentration and lactate dehydrogenase activity have been studied extensively to evaluate the antitumor potential of compound 8. Western blotting tests showed that compound 8 could decrease the MDM2 level and increase p53 levels efficiently. Careful molecular docking suggested that cyclic peptide 8 could bind firmly with MDM2 oncoprotein, indicating that MDM2 may be a potential drug target of the prepared peptides.
Marine Chitooligosaccharide Alters Intestinal Flora Structure and Regulates Hepatic Inflammatory Response to Influence Nonalcoholic Fatty Liver Disease
Authors: Feng Jiayao , Liu Yongjian , Chen Jiajia , Bai Yan , He Jincan , Cao Hua , Che Qishi , Guo Jiao , Su Zhengquan
Published: June 2022

In this study, C57BL/6 mice were given an HFHSD diet for 8 weeks to induce hepatic steatosis and then given COSM solution orally for 12 weeks. The study found that the HFHSD diet resulted in steatosis and insulin resistance in mice. The formation of NAFLD induced by HFHSD diet was related to the imbalance of intestinal flora. However, after COSM intervention, the abundance of beneficial bacteria increased significantly, while the abundance of harmful bacteria decreased significantly. The HFHSD diet also induced changes in intestinal bacterial metabolites, and the content of short-chain fatty acids in cecal contents after COSM intervention was significantly higher than that in the model group. In addition, COSM not only improved LPS levels and barrier dysfunction in the ileum and colon but upregulated protein levels of ZO-1, occludin, and claudin in the colon and downregulated the liver LPS/TLR4/NF-κB inflammatory pathway. We concluded that the treatment of marine chitooligosaccharide COSM could improve the intestinal microflora structure of the fatty liver and activate an inflammatory signaling pathway, thus alleviating the intrahepatic lipid accumulation induced by HFHSD.
Seaweed-Derived Phlorotannins: A Review of Multiple Biological Roles and Action Mechanisms
Authors: Khan Fazlurrahman , Jeong Geum-Jae , Khan Mohd , Tabassum Nazia , Kim Young-Mog
Published: June 2022

Phlorotannins are a group of phenolic secondary metabolites isolated from a variety of brown algal species belonging to the Fucaceae, Sargassaceae, and Alariaceae families. The isolation of phlorotannins from various algal species has received a lot of interest owing to the fact that they have a range of biological features and are very biocompatible in their applications. Phlorotannins have a wide range of therapeutic biological actions, including antimicrobial, antidiabetic, antioxidant, anticancer, anti-inflammatory, anti-adipogenesis, and numerous other biomedical applications. The current review has extensively addressed the application of phlorotannins, which have been extensively investigated for the above-mentioned biological action and the underlying mechanism of action. Furthermore, the current review offers many ways to use phlorotannins to avoid certain downsides, such as low stability. This review article will assist the scientific community in investigating the greater biological significance of phlorotannins and developing innovative techniques for treating both infectious and non-infectious diseases in humans.
Antiviral Activity and Mechanisms of Seaweeds Bioactive Compounds on Enveloped Viruses—A Review
Authors: Lomartire Silvia , Gonçalves Ana M. M.
Published: June 2022

In the last decades, the interest in seaweed has significantly increased. Bioactive compounds from seaweed’s currently receive major attention from pharmaceutical companies as they express several interesting biological activities which are beneficial for humans. The structural diversity of seaweed metabolites provides diverse biological activities which are expressed through diverse mechanisms of actions. This review mainly focuses on the antiviral activity of seaweed’s extracts, highlighting the mechanisms of actions of some seaweed molecules against infection caused by different types of enveloped viruses: influenza, Lentivirus (HIV-1), Herpes viruses, and coronaviruses. Seaweed metabolites with antiviral properties can act trough different pathways by increasing the host’s defense system or through targeting and blocking virus replication before it enters host cells. Several studies have already established the large antiviral spectrum of seaweed’s bioactive compounds. Throughout this review, antiviral mechanisms and medical applications of seaweed’s bioactive compounds are analyzed, suggesting seaweed’s potential source of antiviral compounds for the formulation of novel and natural antiviral drugs.
Updated Trends on the Biodiscovery of New Marine Natural Products from Invertebrates
Authors: Calado Ricardo , Mamede Renato , Cruz Sónia , Leal Miguel C.
Published: June 2022

From 1990–2019, a total of 15,442 New Marine Natural Products from Invertebrates (NMNPIs) were reported. The 2010s saw the most prolific decade of biodiscovery, with 5630 NMNPIs recorded. The phyla that contributed most biomolecules were the Porifera (sponges) (47.2%, 2659 NMNPIs) and the Cnidaria (35.3%, 1989 NMNPIs). The prevalence of these two phyla as the main sources of NMNPIs became more pronounced in the 2010s. The tropical areas of the Pacific Ocean yielded more NMNPIs, most likely due to the remarkable biodiversity of coral reefs. The Indo-Burma biodiversity hotspot (BH) was the most relevant area for the biodiscovery of NMNPIs in the 2010s, accounting for nearly one-third (1819 NMNPIs) of the total and surpassing the top BH from the 1990s and the 2000s (the Sea of Japan and the Caribbean Islands, respectively). The Chinese exclusive economic zone (EEZ) alone contributed nearly one-quarter (24.7%) of all NMNPIs recorded during the 2010s, displacing Japan’s leading role from the 1990s and the 2000s. With the biodiscovery of these biomolecules steadily decreasing since 2012, it is uncertain whether this decline has been caused by lower bioprospecting efforts or the potential exhaustion of chemodiversity from traditional marine invertebrate sources.
nor 3′-Demethoxyisoguaiacin from Larrea tridentata Is a Potential Alternative against Multidrug-Resistant Bacteria Associated with Bovine Mastitis
Authors: Morales-Ubaldo Ana Lizet , Gonzalez-Cortazar Manases , Zaragoza-Bastida Adrian , Meza-Nieto Martín A. , Valladares-Carranza Benjamín , A. Alsayegh Abdulrahman , El-Saber Batiha Gaber , Rivero-Perez Nallely
Published: June 2022

Bovine mastitis is one of the most common diseases in dairy cows, and it causes significant economic losses in dairy industries worldwide. Gram-positive and Gram-negative bacteria can cause bovine mastitis, and many of them have developed antimicrobial resistance. There is an urgent need for novel therapeutic options to treat the disease. Larrea tridentata-derived compounds represent an important potential alternative treatment. The aim of the present study was to isolate and characterize antibacterial compounds from Larrea tridentata against multidrug-resistant bacteria associated with bovine mastitis. The L. tridentata hydroalcoholic extract (LTHE) exhibited antibacterial activity. The extract was subjected to a bipartition, giving an aqueous fraction (moderate antibacterial activity) and an organic fraction (higher antibacterial activity). Chromatographic separation of the organic fraction enabled us to obtain four active sub-fractions. Chemical analyses through HPLC techniques were conducted for the LTHE, fractions, and sub-fraction Ltc1-F3, from which we isolated two compounds, characterized by 1H and 13C NMR analyses. Compound nor-3 demethoxyisoguaiacin exhibited the best antibacterial activity against the evaluated bacteria (MIC: 0.01–3.12 mg/mL; MBC: 0.02–3.12 mg/mL). The results indicated that nor-3 demethoxyisoguaiacin can be used as an alternative treatment for multidrug-resistant bacteria associated with mastitis.
Interactive Effects of Molybdenum, Zinc and Iron on the Grain Yield, Quality, and Nodulation of Cowpea (Vignaunguiculata (L.) Walp.) in North-Western India
Authors: Dhaliwal Salwinder Singh , Sharma Vivek , Shukla Arvind Kumar , Kaur Janpriya , Verma Vibha , Kaur Manmeet , Singh Prabhjot , Brestic Marian , Gaber Ahmed , Hossain Akbar
Published: June 2022

Micronutrient deficiency is a major constraint for the growth, yield and nutritional quality of cowpea which results in nutritional disorders in humans. Micronutrients including molybdenum (Mo), iron (Fe) and zinc (Zn) play a pivotal role in crop nutrition, and their role in different metabolic processes in crops has been highlighted. In order to increase the nutritional quality of cowpea, a field experiment was conducted for two years in which the effect of Mo along with iron (Fe) and zinc (Zn) on productivity, nitrogen and micronutrient uptake, root length and the number of nodules in cowpea cultivation was investigated. It was found that the foliar application of Fe and Zn and their interaction with Mo application through seed priming as well as soil application displayed increased yield, nutrient concentration, uptake and growth parameters which helped to enhance the nutritional quality of cowpea for consumption by the human population. The results of the above experiments revealed that among all the treatments, the soil application of Mo combined with the foliar application of 0.5% each of FeSO4·7H2O and ZnSO4·7H2O (M2F3 treatment) enhanced the grain and stover yield of cowpea, exhibiting maximum values of 1402 and 6104.7 kg ha−1, respectively. Again, the M2F3 treatment resulted in higher Zn, Fe and Mo concentrations in the grain (17.07, 109.3 and 30.26 mg kg−1, respectively) and stover (17.99, 132.7 and 31.22 mg kg−1, respectively) of cowpea. Uptake of Zn, Fe and Mo by the grain (25.23, 153.3 and 42.46 g ha−1, respectively) as well as the stover (104.2, 809.9 and 190.6 g ha−1, respectively) was found to be maximum for the M2F3 treatment. The root length (30.5 cm), number of nodules per plant (73.0) and N uptake in grain and stover (55.39 and 46.15 kg ha−1) were also higher for this treatment. Overall, soil application of Mo along with the foliar application of FeSO4·7H2O (0.5%) and ZnSO4·7H2O (0.5%) significantly improved yield outcomes, concentration, uptake, root length, nodules plant−1 and N uptake of cowpea to alleviate the micronutrient deficiency.
Synthesis, Structure and Biological Evaluations of Zn(II) Pincer Complexes Based on S-Triazine Type Chelator
Authors: Refaat Heba M. , Alotaibi Atallh A. M. , Dege Necmi , El-Faham Ayman , Soliman Saied M.
Published: June 2022

2,4-bis (3,5-dimethyl-1H-pyrazol-1-yl)-6-methoxy-1,3,5-triazine (BPMT) pincer ligand was used to synthesize the new [Zn(BPMT)(NCS)2] (1) and [Zn(BPMT)(Br)2] (2) complexes by a reaction with Zn(NO3)2·6H2O in the presence of either KSCN or KBr, respectively. The structure of complex 1 has been exclusively confirmed using single crystal X-ray diffraction. In this neutral heteroleptic complex, the BPMT is a pincer chelate coordinating the Zn(II) ion via three interactions with the two pyrazole moieties and the s-triazine core. Hence, BPMT is a tridentate NNN-chelate. The coordination environment of Zn(II) is completed by two strong interactions with two terminal SCN− ions via the N-atom. Hence, the Zn(II) is penta-coordinated with a distorted square pyramidal coordination geometry. Hirshfeld analysis indicated the predominance of H…H, H…C and N…H intermolecular interactions. Additionally, the S…H, S…C and S…N contacts are the most significant. The free ligand has no or weak antimicrobial, antioxidant and anticancer activities while the studied Zn(II) complexes showed interesting biological activity. Complex 1 has excellent antibacterial activity against B. subtilis (2.4 μg/mL) and P. vulgaris (4.8 μg/mL) compared to Gentamycin (4.8 μg/mL). Additionally, complex 1 (78.09 ± 4.23 µg/mL) has better antioxidant activity than 2 (365.60 ± 20.89 µg/mL). In addition, complex 1 (43.86 ± 3.12 µg/mL) and 2 (30.23 ± 1.26 µg/mL) have 8 and 12 times the anticancer activity of the free BPMT ligand (372.79 ± 13.64 µg/mL).
Research on Very Volatile Organic Compounds and Odors from Veneered Medium Density Fiberboard Coated with Water-Based Lacquers
Authors: Wang Weidong , Shen Xiwei , Zhang Siqi , Lv Ruixue , Liu Ming , Xu Wang , Chen Yu , Wang Huiyu
Published: June 2022

Very volatile organic compounds (VVOCs) are a group of important odor pollutants affecting indoor air quality that have been shown to be harmful to human health. A 15 L environmental chamber, combined with multi-bed tube was used to collect gases. Fifteen very volatile organic compounds (VVOCs), including 12 odor compounds, were identified from veneered medium density fiberboard coated with water-based lacquer (WB-MDF) using gas chromatography–mass spectrometry/olfactometry (GC-MS/O). The total very volatile organic compound (TVVOC) and total odor intensity (TOI) showed a decreasing trend over time, reaching equilibrium on day 28. TVVOC showed an overall slow-fast-slow emission profile, from day 3 to day 7, with a maximum decay rate of 29.7%. TOI showed the greatest rate of decline from day 1 to day 3, at approximately 12%. Alkane and alcohol VVOCs were the more abundant compounds, accounting for at least 60% and even up to 80% of the total. The major odor impression was fruity, with a highest odor rating of 6.6, followed by sweet, with an odor rating of 6.1. Although the odor impression changed from sweet to fruity over time, it seemed pleasant overall. The odor contributors were mainly alkanes, alcohols, esters, and ethers, which had relatively high odor intensities. The main odor-contributing substances were dichloromethane, ethanol, ethyl acetate, 2-methylacrylic acid methyl ester, and tetrahydrofuran. When WB-MDF is used for furniture or other decorative materials, it is strongly recommended that it be stored under ventilation for at least 28 days and the adoption of substitute solvents of lacquers, modified adhesives, and low-odor wood raw materials is recommended. These possible initiatives would contribute to the aim of building an environmentally friendly indoor environment.
Coadsorption Interfered CO Oxidation over Atomically Dispersed Au on h-BN
Authors: Liu Xin , Zhang Xin , Meng Changgong
Published: June 2022

Similar to the metal centers in biocatalysis and homogeneous catalysis, the metal species in single atom catalysts (SACs) are charged, atomically dispersed and stabilized by support and substrate. The reaction condition dependent catalytic performance of SACs has long been realized, but seldom investigated before. We investigated CO oxidation pathways over SACs in reaction conditions using atomically dispersed Au on h-BN (AuBN) as a model with extensive first-principles-based calculations. We demonstrated that the adsorption of reactants, namely CO, O2 and CO2, and their coadsorption with reaction species on AuBN would be condition dependent, leading to various reaction species with different reactivity and impact the CO conversion. Specifically, the revised Langmuir–Hinshelwood pathway with the CO-mediated activation of O2 and dissociation of cyclic peroxide intermediate followed by the Eley–Rideal type reduction is dominant at high temperatures, while the coadsorbed CO-mediated dissociation of peroxide intermediate becomes plausible at low temperatures and high CO partial pressures. Carbonate species would also form in existence of CO2, react with coadsorbed CO and benefit the conversion. The findings highlight the origin of the condition-dependent CO oxidation performance of SACs in detailed conditions and may help to rationalize the current understanding of the superior catalytic performance of SACs.