bluuebunny/crossref_metadata_2025 huggingface dataset:
Simple Breaker Index Formula Using Linear Model
Authors: Lee Kwang-Ho , Cho Yong-Hwan
Published: July 2021

Breaking waves generated by wave shoaling in coastal areas have a close relationship with various physical phenomena in coastal regions. Therefore, it is crucial to accurately predict breaker indexes such as breaking wave height and breaking depth when designing coastal structures. Many studies on wave breaking have been carried out, and many experimental data have been documented. Representative studies on wave breaking provide many empirical formulas for the prediction of breaking index, mainly through hydraulic model experiments. However, the existing empirical formulas for breaking index determine the coefficients of the assumed equation through statistical analysis of data under the assumption of a specific equation. This study presents an alternative method to estimate breaker index using representative linear-based supervised machine learning algorithms that show high predictive performance in various research fields related to regression or classification problems. Based on the used machine learning methods, a new simple linear equation for the prediction of breaker index is presented. The newly proposed breaker index formula showed similar predictive performance compared to the existing empirical formula, although it was a simple linear equation.
Automatic Segmentation of Mandible from Conventional Methods to Deep Learning—A Review
Authors: Qiu Bingjiang , van der Wel Hylke , Kraeima Joep , Glas Haye Hendrik , Guo Jiapan , Borra Ronald J. H. , Witjes Max Johannes Hendrikus , van Ooijen Peter M. A.
Published: July 2021

Medical imaging techniques, such as (cone beam) computed tomography and magnetic resonance imaging, have proven to be a valuable component for oral and maxillofacial surgery (OMFS). Accurate segmentation of the mandible from head and neck (H&N) scans is an important step in order to build a personalized 3D digital mandible model for 3D printing and treatment planning of OMFS. Segmented mandible structures are used to effectively visualize the mandible volumes and to evaluate particular mandible properties quantitatively. However, mandible segmentation is always challenging for both clinicians and researchers, due to complex structures and higher attenuation materials, such as teeth (filling) or metal implants that easily lead to high noise and strong artifacts during scanning. Moreover, the size and shape of the mandible vary to a large extent between individuals. Therefore, mandible segmentation is a tedious and time-consuming task and requires adequate training to be performed properly. With the advancement of computer vision approaches, researchers have developed several algorithms to automatically segment the mandible during the last two decades. The objective of this review was to present the available fully (semi)automatic segmentation methods of the mandible published in different scientific articles. This review provides a vivid description of the scientific advancements to clinicians and researchers in this field to help develop novel automatic methods for clinical applications.
Modeling Credit Risk: A Category Theory Perspective
Authors: Tran Cao Son , Nicolau Dan , Nayak Richi , Verhoeven Peter
Published: July 2021

This paper proposes a conceptual modeling framework based on category theory that serves as a tool to study common structures underlying diverse approaches to modeling credit default that at first sight may appear to have nothing in common. The framework forms the basis for an entropy-based stacking model to address issues of inconsistency and bias in classification performance. Based on the Lending Club’s peer-to-peer loans dataset and Taiwanese credit card clients dataset, relative to individual base models, the proposed entropy-based stacking model provides more consistent performance across multiple data environments and less biased performance in terms of default classification. The process itself is agnostic to the base models selected and its performance superior, regardless of the models selected.
The Relationship between Carry Trade and Asset Markets in South Africa
Authors: Bonga-Bonga Lumengo , Maake Tebogo
Published: July 2021

This paper investigates the extent of volatility or risk spillovers between the currency carry trade and asset markets, namely the equity and bond markets, in South Africa to infer the extent of the connectivity between the two markets. The carry trade operation examined in this paper involves two strategies, both of which use the South African rand as the investment currency, with the U.S. dollar and the Japanese yen as the funding currencies. The vector autoregressive BEKK-Generalised Autoregressive Conditional Heteroscedastic (multivariate VAR-BEKK-GARCH) model is used to this end. Moreover, the paper assesses the dynamic correlation between each currency carry trade and asset markets to infer the time-varying dependence between the two markets. The results of the empirical analysis show evidence of volatility spillover between the carry trade returns and the two asset market returns. The extent of the spillover depends on the choice of the funding currency, with the U.S. dollar-funded strategy transmitting more shocks to the South African equity market compared to the bond market. Moreover, the synchronisation of the dynamic correlation between each asset market and the currency carry trade returns shows that any possibility of arbitrage is precluded in the currency carry trade market.
Micro-Geographies of Information and Communication Technology Firms in a Shrinking Medium-Sized Industrial City of Ostrava (Czechia)
Authors: Ženka Jan , Krtička Luděk , Paszová Lenka , Pundová Tereza , Rudincová Kateřina , Šťastná Simona , Svetlíková Veronika , Matula Jan
Published: July 2021

We aimed to explain the spatial distribution of information and communication technology (ICT) firms in the city of Ostrava as an example of a medium-sized, shrinking, polycentric industrial city. The primary research question was to what extent micro-geographic location factors affect the current spatial clustering of ICT firms in polycentric cities characteristic by relatively weak urbanization economies and mostly routine character of ICT activities. We analyse and test the effects of the urban form at the level of urban blocks and individual buildings (considering their height, technical condition, age and dominant function) on the clustering of ICT firms of various sizes and ownership statuses. The inquiry was based on a detailed field mapping (using ArcGIS Collector) of ICT firms and physical/functional characteristics of the buildings and their immediate surroundings. ICT firms are significantly spatially concentrated in the historic city centre and inner city. Spatial patterns of ICT firms focused on less knowledge-intensive, routine and/or lower value-added functions do not differ fundamentally from innovative firms developing new products. Preference of denser, walkable, mixed-use neighbourhoods in urban cores/inner cities can be found in the group of firms focusing on routine functions: rather for larger than for smaller firms and domestic than foreign-owned firms.
A Potential Role and Contribution of Androgens in Placental Development and Pregnancy
Authors: Parsons Agata M. , Bouma Gerrit J.
Published: July 2021

Successful pregnancy requires the establishment of a highly regulated maternal–fetal environment. This is achieved through the harmonious regulation of steroid hormones, which modulate both maternal and fetal physiology, and are critical for pregnancy maintenance. Defects in steroidogenesis and steroid signaling can lead to pregnancy disorders or even fetal loss. The placenta is a multifunctional, transitory organ which develops at the maternal–fetal interface, and supports fetal development through endocrine signaling, the transport of nutrients and gas exchange. The placenta has the ability to adapt to adverse environments, including hormonal variations, trying to support fetal development. However, if placental function is impaired, or its capacity to adapt is exceeded, fetal development will be compromised. The goal of this review is to explore the relevance of androgens and androgen signaling during pregnancy, specifically in placental development and function. Often considered a mere precursor to placental estrogen synthesis, the placenta in fact secretes androgens throughout pregnancy, and not only contains the androgen steroid nuclear receptor, but also non-genomic membrane receptors for androgens, suggesting a role of androgen signaling in placental function. Moreover, a number of pregnancy disorders, including pre-eclampsia, gestational diabetes, intrauterine growth restriction, and polycystic ovarian syndrome, are associated with abnormal androgen levels and androgen signaling. Understanding the role of androgens in the placenta will provide a greater understanding of the pathophysiology of pregnancy disorders associated with androgen elevation and its consequences.
Joint Inventory Replenishment Planning of an E-Commerce Distribution System with Distribution Centers at Producers’ Locations
Authors: Dai Bo , Li Fenfen
Published: July 2021

In this study, joint inventory replenishment planning of an Alibaba distribution system is investigated, which contributes to the circular economy concept. The distribution system includes suppliers, central distribution centers, and front distribution centers. The total replenishment cost of the distribution system can be reduced by setting up distribution centers at producers’ locations (PDCs), which also helps to reduce the wastages of commodities during the transportation and CO2 emission released by transportation. The joint replenishments of multiple products are constrained by a maximum joint replenishment quantity. Trans-shipments happen among different distribution centers. The considered problem seeks to find the replenishment quantities of products among stocks, which can minimize the total replenishment cost of the system, and is formulated as a novel mathematical model. The effectiveness of our proposed model is validated by computational experiments based on Alibaba’s data. The results indicate that PDCs and trans-shipments can bring about lower replenishment costs if a common service level of the system is given.
Effect of Surface Treatment of Polypropylene (PP) Fiber on the Sulfate Corrosion Resistance of Cement Mortar
Authors: Hu Yanyan , Ma Linlin
Published: July 2021

Sulfate erosion is one of the most complex and harmful chemical corrosion actions. Following sulfate erosion, concrete expands, cracks, dissolves, peels off, and decreases in strength, which affects the durability of structures. Polypropylene fiber (PP) is widely used in various concrete structures because of its good mechanical properties and chemical corrosion resistance. However, PP fiber has a number of shortcomings, such as a smooth surface, poor hydrophilicity, lack of active groups in the molecular chain, and agglomeration and poor dispersion in cement-based materials. These issues limit its application in cement-based materials. Although the use of a silane coupling agent to modify the surface of PP fiber is effective, the influence of treated PP fiber on the sulfate resistance of cement-based materials is not significant. In this study, a PP fiber treated with a silane coupling agent was used to examine effects of different cement-to-sand ratios (C/S) and dosages of the treated PP fiber on the sulfate erosion resistance of cement mortar. Furthermore, the apparent morphology, mass loss rate, flexural strength, corrosion resistance coefficient, and microstructure of the concrete were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results revealed that the PP fiber became rough after modification. Active groups were introduced on the fiber surface, which were well dispersed in the mortar and formed a good network distribution structure in the cement mortar, thereby slowing the erosion rate of the PP fiber mortar in a sodium sulfate solution. At a C/S ratio of 1:1 and a treated fiber dosage of 0.6%, the treated fiber mortar has exhibited good sulfate resistance. In addition, the monofilament fiber immersion test revealed that a layer of sodium sulfate crystals was deposited on the fiber surface, thereby increasing the roughness of the fiber surface and the pull-out force of the fiber from the cement matrix, this result indicated that the interfacial adhesion between the treated PP fiber and cement matrix was improved, which in turn led to the improvement in the sulfate erosion resistance of the treated PP fiber.
Finance for the Environment: A Scientometrics Analysis of Green Finance
Authors: Cai Rui , Guo Jianluan
Published: July 2021

To protect environmental sustainability, organizations are moving their focus towards greening the business process. Similarly to any other business function, financial management has also turned to environmentally friendly activities. Green finance is a new financial pattern that integrates environmental protection and economic profits. This paper analyses the publications on green finance, and their intellectual structure and networking. The bibliometric data on green finance research have been extracted from the Scopus database. This study finds the most productive countries, universities, authors, journals, and most prolific publications in green finance, through examining the published works. Also, the study visualizes the intellectual network by mapping bibliographic coupling (BC) and co-citation. The study’s essential contribution is the analysis of green finance developments and trajectories that can help scholars and practitioners to appreciate the trend and future studies.
An Overview of Non-Destructive Testing of Goss Texture in Grain-Oriented Magnetic Steels
Authors: Faba Antonio , Quondam Antonio Simone
Published: July 2021

Grain oriented steels are widely used for electrical machines and components, such as transformers and reactors, due to their high magnetic permeability and low power losses. These outstanding properties are due to the crystalline structure known as Goss texture, obtained by a suitable process that is well-known and in widespread use among industrial producers of ferromagnetic steel sheets. One of the most interesting research areas in this field has been the development of non-destructive methods for the quality assessment of Goss texture. In particular, the study of techniques that can be implemented in industrial processes is very interesting. Here, we provide an overview of techniques developed in the past, novel approaches recently introduced, and new perspectives. The reliability and accuracy of several methods and equipment are presented and discussed.
Efficient Pre-Solve Algorithms for the Schwerin and Falkenauer_U Bin Packing Benchmark Problems for Getting Optimal Solutions with High Probability
Authors: Ábrahám Gyula , Dósa György , Dulai Tibor , Tuza Zsolt , Werner-Stark Ágnes
Published: July 2021

Bin Packing is one of the research areas of Operations Research with many industrial applications, as well as rich theoretical impact. In this article, the authors deal with Bin Packing on the practical side: they consider two Bin Packing Benchmark classes. These benchmark problems are often used to check the “usefulness”, efficiency of algorithms. The problem is well-known to be NP-hard. Instead of introducing some exact, heuristic, or approximation method (as usual), the problem is attacked here with some kind of greedy algorithm. These algorithms are very fast; on the other hand, they are not always able to provide optimal solutions. Nevertheless, they can be considered as pre-processing algorithms for solving the problem. It is shown that almost all problems in the considered two benchmark classes are, in fact, easy to solve. In case of the Schwerin class, where there are 200 instances, it is obtained that all instances are solved by the greedy algorithm, optimally, in a very short time. The Falkenauer U class is a little bit harder, but, here, still more than 91% of the instances are solved optimally very fast, with the help of another greedy algorithm. Based on the above facts, the main contribution of the paper is to show that pre-processing is very useful for solving such kinds of problems.
Multi-Step Inertial Hybrid and Shrinking Tseng’s Algorithm with Meir–Keeler Contractions for Variational Inclusion Problems
Authors: Wang Yuanheng , Yuan Mingyue , Jiang Bingnan
Published: July 2021

In our paper, we propose two new iterative algorithms with Meir–Keeler contractions that are based on Tseng’s method, the multi-step inertial method, the hybrid projection method, and the shrinking projection method to solve a monotone variational inclusion problem in Hilbert spaces. The strong convergence of the proposed iterative algorithms is proven. Using our results, we can solve convex minimization problems.
Membrane Reactor for Methanol Synthesis Using Si-Rich LTA Zeolite Membrane
Authors: Seshimo Masahiro , Liu Bo , Lee Hey Ryeon , Yogo Katsunori , Yamaguchi Yuichiro , Shigaki Nobuyuki , Mogi Yasuhiro , Kita Hidetoshi , Nakao Shin-ichi
Published: July 2021

We successfully demonstrated the effect of a membrane reactor for methanol synthesis to improve one-pass CO2 conversion. An Si-rich LTA membrane for dehydration from a methanol synthesis reaction field was synthesized by the seed-assisted hydrothermal synthesis method. The H2O permselective performance of the membrane showed 1.5 × 10−6 mol m−2 s−1 Pa−1 as H2O permeance and around 2000 as selectivity of H2O/MeOH at 473 K. From the results of membrane reactor tests, the CO2 conversion of the membrane reactor was higher than that of the conventional packed-bed reactor under the all of experimental conditions. Especially, at 4 MPa of reaction pressure, the conversion using the membrane reactor was around 60%. In the case of using a packed-bed reactor, the conversion was 20% under the same conditions. In addition, the calculated and experimental conversion were in good agreement in both the case of the membrane reactor and packed-bed reactor.
The Mechanical and Thermoelectric Properties of Bi2Te3-Based Alloy Prepared by Constrained Hot Compression Technique
Authors: Qian Dongsheng , Ye Ziyi , Pan Libo , Zuo Zhijiang , Yang Dongwang , Yan Yonggao
Published: July 2021

This study proposes a constrained hot compression-molding (CHCM) technique for preparing Bi2Te3-based alloys. This method overcomes the problem of easy cleavage and destruction for the zone-melted Bi2Te3-based alloy, which is beneficial to improve the material utilization rate and thermoelectric devices yield in the commercial manufacturing process. The stress field distribution inside the CHCM specimen is explored via finite element analysis. The compressive strength of the CHCM sample is above 44 MPa, which is about 38% higher than that of the zone melting (ZM) material. Meanwhile, the CHCM sample shows a much lower electrical conductivity and thermal conductivity, but a higher Seebeck coefficient than that of the ZM sample, which is mainly due to the increase of the line defect concentration induced by the CHCM process. Finally, a maximum thermoelectric figure of merit (ZT) value of 0.6 was achieved for CHCM sample.
Remote Cooling of Rolls in Hot Rolling; Applicability to Other Processes
Authors: Bohacek Jan , Raudensky Miroslav , Kotrbacek Petr
Published: July 2021

A novel method of cooling rolls in hot rolling is proposed. This method uses a combination of solid jet nozzles and specially shaped deflecting vanes. The vanes transform the incoming cylindrical water jet into a flat fan. Thereby, the coolant can be directed into hardly accessible locations whilst maintaining the optimal angle of impingement. The vanes allow for effectively cooling the roll surface near the rolling gap, which is otherwise not possible with classical flat fan nozzles. The jet impact is tangential due to the limited room for nozzle mounts or a coolant supply. The developed method was laboratory tested. A similar cooling efficiency was found between the vane and the flat fan nozzle. The latter was however mounted in a position impossible in the plant. The potential of the proposed cooling is, therefore, eminent. Apart from hot rolling, it could be exploited in other technological processes such as high pressure die casting, machining, turning, hot stamping, etc.
A Review on Plants and Biomass Wastes as Organic Green Corrosion Inhibitors for Mild Steel in Acidic Environment
Authors: Reza Norbaayah Ahmad , Akhmal Nor Hasrul , Fadil Nor Akmal , Taib Mohd Firdaus Mohd
Published: July 2021

Acid corrosion is a problem pertaining to corrosion that involves an acid solution. It is important to treat metal to preserve its integrity. Thus, acids are utilized to clean and treat metal surfaces. In return, this may lead to over-etching and metal degradation. Corrosion inhibitors were introduced as a solution for the issue. However, there are some problems associated with the usage of conventional corrosion inhibitors. Traces of nitrites and chromates that are present in the inhibitors may lead to serious health and environmental issues. As a solution, organic green corrosion inhibitors have been studied to replace the conventional corrosion inhibitors. These inhibitor molecules form a protective layer on top of the metal surface to suppress metal dissolution when added to the acid solution. This process prevents direct contact between the metal surfaces and the acid environment. This study explores the usage of natural resources and biomass wastes as the basis for organic green corrosion inhibitors. This study also provides some suggestions for new biomass wastes that can be studied as new organic corrosion inhibitors, and it is aimed at opening the perspective of researchers on exploring new organic inhibitors by using natural resources and biomass wastes.
Hierarchical Harmonization of Atom-Resolved Metabolic Reactions across Metabolic Databases
Authors: Jin Huan , Moseley Hunter N. B.
Published: July 2021

Metabolic models have been proven to be useful tools in system biology and have been successfully applied to various research fields in a wide range of organisms. A relatively complete metabolic network is a prerequisite for deriving reliable metabolic models. The first step in constructing metabolic network is to harmonize compounds and reactions across different metabolic databases. However, effectively integrating data from various sources still remains a big challenge. Incomplete and inconsistent atomistic details in compound representations across databases is a very important limiting factor. Here, we optimized a subgraph isomorphism detection algorithm to validate generic compound pairs. Moreover, we defined a set of harmonization relationship types between compounds to deal with inconsistent chemical details while successfully capturing atom-level characteristics, enabling a more complete enabling compound harmonization across metabolic databases. In total, 15,704 compound pairs across KEGG (Kyoto Encyclopedia of Genes and Genomes) and MetaCyc databases were detected. Furthermore, utilizing the classification of compound pairs and EC (Enzyme Commission) numbers of reactions, we established hierarchical relationships between metabolic reactions, enabling the harmonization of 3856 reaction pairs. In addition, we created and used atom-specific identifiers to evaluate the consistency of atom mappings within and between harmonized reactions, detecting some consistency issues between the reaction and compound descriptions in these metabolic databases.
Recent Development and Perspectives of Optimization Design Methods for Piezoelectric Ultrasonic Transducers
Authors: Chen Dongdong , Wang Linwei , Luo Xingjun , Fei Chunlong , Li Di , Shan Guangbao , Yang Yintang
Published: July 2021

A piezoelectric ultrasonic transducer (PUT) is widely used in nondestructive testing, medical imaging, and particle manipulation, etc., and the performance of the PUT determines its functional performance and effectiveness in these applications. The optimization design method of a PUT is very important for the fabrication of a high-performance PUT. In this paper, traditional and efficient optimization design methods for a PUT are presented. The traditional optimization design methods are mainly based on an analytical model, an equivalent circuit model, or a finite element model and the design parameters are adjusted by a trial-and-error method, which relies on the experience of experts and has a relatively low efficiency. Recently, by combining intelligent optimization algorithms, efficient optimization design methods for a PUT have been developed based on a traditional model or a data-driven model, which can effectively improve the design efficiency of a PUT and reduce its development cycle and cost. The advantages and disadvantages of the presented methods are compared and discussed. Finally, the optimization design methods for PUT are concluded, and their future perspectives are discussed.
Design and Implementation of Ultrasonic Impact Peening-Based Device for Stainless Steel Surface Texture Fabrication
Authors: Hu Wangjie , Zhang Qiang , Wang Xiaohui , Zhao Dongxu , Hu Zhenjiang , Zhao Xuesen , Shao Haiyan , Men Xiuhua , Sun Tao
Published: July 2021

The manufacturing of precise surface microstructures with low cost is needed for surface texturing-based surface engineering. In this paper, a device for the fabrication of surface microgroove texture on stainless steel based on ultrasonic impact peening (UIP) is proposed and investigated. First, the principle of applying the UIP into the fabrication of surface texture is analytically described. Then, the design of the UIP device, particularly the design of functional systems and mechanical structures, is carried out. Next, a UIP experimental device is built, and is further applied to fabricate microgroove textures on 316L stainless steel. The subsequent experimental characterization of microgroove morphology demonstrates the feasibility of the designed UIP device for the fabrication of stainless steel surface texture.
Clinical Characteristics of Patients with Tick-Borne Encephalitis (TBE): A European Multicentre Study from 2010 to 2017
Authors: Kohlmaier Benno , Schweintzger Nina , Sagmeister Manfred , Švendová Vendula , Kohlfürst Daniela , Sonnleitner Astrid , Leitner Manuel , Berghold Andrea , Schmiedberger Erich , Fazekas Franz , Pichler Alexander , Rejc-Marko Jana , Růžek Daniel , Dufková Lucie , Čejková Darina , Husa Petr , Pýchová Martina , Krbková Lenka , Chmelík Václav , Štruncová Věra , Zavadska Dace , Karelis Guntis , Mickiene Aukse , Zajkowska Joanna , Bogovič Petra , Strle Franc , Zenz Werner ,   the EU-TICK-BO STUDY GROUP
Published: July 2021

Tick-borne encephalitis (TBE) virus is a major cause of central nervous system infections in endemic countries. Here, we present clinical and laboratory characteristics of a large international cohort of patients with confirmed TBE using a uniform clinical protocol. Patients were recruited in eight centers from six European countries between 2010 and 2017. A detailed description of clinical signs and symptoms was recorded. The obtained information enabled a reliable classification in 553 of 555 patients: 207 (37.3%) had meningitis, 273 (49.2%) meningoencephalitis, 15 (2.7%) meningomyelitis, and 58 (10.5%) meningoencephalomyelitis; 41 (7.4%) patients had a peripheral paresis of extremities, 13 (2.3%) a central paresis of extremities, and 25 (4.5%) had single or multiple cranial nerve palsies. Five (0.9%) patients died during acute illness. Outcome at discharge was recorded in 298 patients. Of 176 (59.1%) patients with incomplete recovery, 80 (27%) displayed persisting symptoms or signs without recovery expectation. This study provides further evidence that TBE is a severe disease with a large proportion of patients with incomplete recovery. We suggest monitoring TBE in endemic European countries using a uniform protocol to record the full clinical spectrum of the disease.
Preventing Extinction of the Critically Endangered Dactylorhiza incarnata subsp. ochroleuca in Britain Using Symbiotic Seedlings for Reintroduction
Authors: Sarasan Viswambharan , Pankhurst Tim , Yokoya Kazutomo , Sriskandarajah Sridevy , McDiarmid Faye
Published: July 2021

The yellow early marsh-orchid (Dactylorhiza incarnata subsp. ochroleuca) is critically endangered in the UK. Reintroduction of this threatened orchid to former haunts that have been restored is a long-term objective of this study. Identifying germination-specific mycorrhizal fungus lineages from closely related species is used as a method due to the extremely small number of plants left in the wild. A putative orchid mycorrhizal fungus of the family Tulasnellaceae, isolated from Dactylorhiza praetermissa, supported in vitro seed germination to produce reintroduction-ready seedlings. Reintroduced symbiotic seedlings survived over the winter months in the flooded reintroduction site (RS). The comparative soil analysis for key nutrients before reintroduction showed that phosphorus content in the RS is very low compared to the soil collected from the wild site (WS) where the last viable population exists. On the other hand, C:N ratio in the soil at the WS and RS were not significantly different. To our knowledge, this is the first-ever report on the reintroduction of symbiotic seedlings of a threatened orchid back to the wild in the UK.
Disease-Alleviating Effects of Peroral Activated Charcoal Treatment in Acute Murine Campylobacteriosis
Authors: Bereswill Stefan , Mousavi Soraya , Weschka Dennis , Heimesaat Markus M.
Published: July 2021

Foodborne Campylobacter jejuni infections are on the rise and responsible for worldwide serious health issues. Increasing resistance of C. jejuni strains against antimicrobial treatments, necessitates antibiotics-independent treatment options for acute campylobacteriosis. Activated charcoal (AC) constitutes a long-known and safe compound for the treatment of bacterial enteritis. In this preclinical intervention study, we addressed potential anti-pathogenic and immune-modulatory effects of AC during acute experimental campylobacteriosis. Therefore, microbiota-depleted IL-10−/− mice were infected with C. jejuni by gavage and challenged with either AC or placebo via the drinking water starting on day 2 post-infection. On day 6 post-infection, AC as compared to placebo-treated mice did not only harbor lower intestinal pathogen loads but also presented with alleviated C. jejuni-induced clinical signs such as diarrhea and wasting symptoms. The improved clinical outcome of AC-treated mice was accompanied by less colonic epithelial cell apoptosis and reduced pro-inflammatory immune responses in the intestinal tract. Notably, AC treatment did not only alleviate intestinal, but also extra-intestinal and systemic immune responses as indicated by dampened pro-inflammatory mediator secretion. Given the anti-pathogenic and immune-modulatory properties of AC in this study, a short-term application of this non-toxic drug constitutes a promising antibiotics-independent option for the treatment of human campylobacteriosis.
Polytypism of Compounds with the General Formula Cs{Al2[TP6O20]} (T = B, Al): OD (Order-Disorder) Description, Topological Features, and DFT-Calculations
Authors: Aksenov Sergey M. , Kuznetsov Alexey N. , Antonov Andrey A. , Yamnova Natalia A. , Krivovichev Sergey V. , Merlino Stefano
Published: July 2021

The crystal structures of compounds with the general formula Cs{[6]Al2[[4]TP6O20]} (where T = Al, B) display order-disorder (OD) character and can be described using the same OD groupoid family. Their structures are built up by two kinds of nonpolar layers, with the layer symmetries Pc(n)2 (L2n+1-type) and Pc(a)m (L2n-type) (category IV). Layers of both types (L2n and L2n+1) alternate along the b direction and have common translation vectors a and c (a ~ 10.0 Å, c ~ 12.0 Å). All ordered polytypes as well as disordered structures can be obtained using the following partial symmetry operators that may be active in the L2n type layer: the 21 screw axis parallel to c [– – 21] or inversion centers and the 21 screw axis parallel to a [21 – –]. Different sequences of operators active in the L2n type layer ([– – 21] screw axes or inversion centers and [21 – –] screw axes) define the formation of multilayered structures with the increased b parameter, which are considered as non-MDO polytypes. The microporous heteropolyhedral MT-frameworks are suitable for the migration of small cations such as Li+, Na+ Ag+. Compounds with the general formula Rb{[6]M3+[[4]T3+P6O20]} (M = Al, Ga; T = Al, Ga) are based on heteropolyhedral MT-frameworks with the same stoichiometry as in Cs{[6]Al2[[4]TP6O20]} (where T = Al, B). It was found that all the frameworks have common natural tilings, which indicate the close relationships of the two families of compounds. The conclusions are supported by the DFT calculation data.
Geochemical Characteristics of Late Ordovician Shales in the Upper Yangtze Platform, South China: Implications for Redox Environmental Evolution
Authors: Lin Donglin , Tang Shuheng , Xi Zhaodong , Zhang Bing , Ye Yapei
Published: July 2021

Changes to the redox environment of seawater in the Late Ordovician affect the process of organic matter enrichment and biological evolution. However, the evolution of redox and its underlying causes remain unclear. This paper analyzed the vertical variability of main, trace elements and δ34Spy from a drill core section (well ZY5) in the Upper Yangtze Platform, and described the redox conditions, paleoproductivity and paleoclimate variability recorded in shale deposits of the P. pacificus zone and M. extraordinarius zone that accumulated during Wufeng Formation. The results showed that shale from well ZY5 in Late Ordovician was deposited under oxidized water environment, and there are more strongly reducing bottom water conditions of the M. extraordinarius zone compared with the P. pacificus zone. Excess silica (SiO2(exc)) and substitution index of paleoproductivity (Y) indicated that the P. pacificus zone had higher paleoproductivity whereas the M. extraordinarius zone was lower. The high productivity level controlled O2 release in the shallow water area as well as the oxidation degree of the P. pacificus zone. The decrease of productivity and the relatively stagnant water mass of the inner Yangtze Sea controlled the formation of relatively reduced water conditions in the M. extraordinarius zone. The chemical index of alteration (CIA) results suggested that palaeoclimatic conditions changed from warm and humid to cold and dry climate from the P. pacificus to the M. extraordinarius zones in the study area. A comparative analysis of the published Fe-S-C data for the Xiushan Datianba section showed that in the P. pacificus zone of the inner Yangtze Sea, warm and humid climate conditions drove high productivity, sulphate flux and low reactive iron flux, which promoted the expansion of oxic ocean-surface waters and mid-depth euxinic waters. In the M. extraordinarius zone, the cold and dry climate with significant uplift of the Xiang’e Submarine High led to the relative sea level decline, resulting in low productivity, sulfate flux and high reactive iron flux, which promoted the expansion of the mid-depth ferruginous waters and the shrinkage of oxic ocean-surface waters. The results offered new insights into the co-evolution of continents and oceans, and explained the role of continental weathering and uplift of the Xiang’e Submarine High in the exchange of sulfate flux and nutrients in the redox environment change of inner Yangtze Sea during the Late Ordovician.
A Criterion for Estimating the Strength of Flocculated Aggregates in Salt Solutions
Authors: Jeldres Matías , Ayala Luis , Robles Pedro , Gálvez Edelmira , Leiva Williams H. , Toledo Pedro G. , Jeldres Ricardo I.
Published: July 2021

A simple criterion is proposed to quantitatively estimate the resistance of aggregates based on incremental mechanical shear disturbances. Aggregate strength can be affected by the hydrodynamic conditions under which flocculation occurs; therefore, an experimental method is standardized to determine the resistance of aggregate structures that are formed under defined conditions of salinity (NaCl 0–0.1 M), mixing time (3 min), and mean shear rate (G = 273 s−1). Kaolin particles were flocculated in saline solutions with an anionic flocculant of high molecular weight. The method involves increasing the mean shear rate (G = 0–1516 s−1). Each increment represents a new experiment that starts from the base of 273 s−1. Target aggregates are increasingly fragmented as mechanical disturbance increases. The monotonic relationship between the mean shear rate increments (ΔG) and the final size of the aggregates is used for a quantitative estimate of the resistance of the target aggregates since this resistance underlies this relationship. The evolution of aggregate size is analyzed by the Focused Beam Reflectance Measurement (FBRM) method, which may capture the chord length distribution on concentrated slurries. To estimate and compare the resistance of the target aggregates in solutions with different salinities, a pseudo-first-order model that describes the rupture degree as a function of shear rate increments obtains the characteristic shear rate. The rupture percentage is reached with considerably lower agitation increments at higher salinity than at low salinity. This criterion is expected to help improve the efficiency of solid–liquid separation processes, especially in plants operating with seawater, be it raw or partially desalinated.
A Novel Energy-from-Waste Approach for Electrical Energy Production by Galvano–Fenton Process
Authors: Gasmi Intissar , Haddour Naoufel , Hamdaoui Oualid , Kerboua Kaouther , Alghyamah Abdulaziz , Buret François
Published: July 2021

A novel approach allowing the production of electrical energy by an advanced oxidation process is proposed to eliminate organic micropollutants (MPs) in wastewaters. This approach is based on associating the Galvano–Fenton process to the generation of electrical power. In the previous studies describing the Galvano–Fenton (GF) process, iron was directly coupled to a metal of more positive potential to ensure degradation of organic pollutants without any possibility of producing electrical energy. In this new approach, the Galvano–Fenton process is constructed as an electrochemical cell with an external circuit allowing recovering electrons exchanged during the process. In this study, Malachite Green (MG) dye was used as a model of organic pollutant. Simultaneous MG degradation and electrical energy production with the GF method were investigated in batch process. The investigation of various design parameters emphasis that utilization of copper as a low-cost cathode material in the galvanic couple, provides the best treatment and electrical production performances. Moreover, these performances are improved by increasing the surface area of the cathode. The present work reveals that the GF process has a potential to provide an electrical power density of about 200 W m−2. These interesting performances indicate that this novel Energy-from-Waste strategy of the GF process could serve as an ecological solution for wastewater treatment.
Research Progress and Development Trends of Acoustic Metamaterials
Authors: Song Hao , Ding Xiaodong , Cui Zixian , Hu Haohao
Published: July 2021

Acoustic metamaterials are materials with artificially designed structures, which have characteristics that surpass the behavior of natural materials, such as negative refraction, anomalous Doppler effect, plane focusing, etc. This article mainly introduces and summarizes the related research progress of acoustic metamaterials in the past two decades, focusing on meta-atomic acoustic metamaterials, metamolecular acoustic metamaterials, meta-atomic clusters and metamolecule cluster acoustic metamaterials. Finally, the research overview and development trend of acoustic metasurfaces are briefly introduced.
Solid-Phase “Self-Hydrolysis” of [Zn(NH3)4MoO4@2H2O] Involving Enclathrated Water—An Easy Route to a Layered Basic Ammonium Zinc Molybdate Coordination Polymer
Authors: Béres Kende Attila , Sajó István E. , Lendvay György , Trif László , Petruševski Vladimir M. , Barta-Holló Berta , Korecz László , Franguelli Fernanda Paiva , László Krisztina , Szilágyi Imre Miklós , Kótai László
Published: July 2021

An aerial humidity-induced solid-phase hydrolytic transformation of the [Zn(NH3)4]MoO4@2H2O (compound 1@2H2O) with the formation of [(NH4)xH(1−x)Zn(OH)(MoO4)]n (x = 0.92–0.94) coordination polymer (formally NH4Zn(OH)MoO4, compound 2) is described. Based on the isostructural relationship, the powder XRD indicates that the crystal lattice of compound 1@2H2O contains a hydrogen-bonded network of tetraamminezinc (2+) and molybdate (2−) ions, and there are cavities (O4N4(μ-H12) cube) occupied by the two water molecules, which stabilize the crystal structure. Several observations indicate that the water molecules have no fixed positions in the lattice voids; instead, the cavity provides a neighborhood similar to those in clathrates. The @ symbol in the notation is intended to emphasize that the H2O in this compound is enclathrated rather than being water of crystallization. Yet, signs of temperature-dependent dynamic interactions with the wall of the cages can be detected, and 1@2H2O easily releases its water content even on standing and yields compound 2. Surprisingly, hydrolysis products of 1 were observed even in the absence of aerial humidity, which suggests a unique solid-phase quasi-intramolecular hydrolysis. A mechanism involving successive substitution of the ammonia ligands by water molecules and ammonia release is proposed. An ESR study of the Cu-doped compound 2 (2#dotCu) showed that this complex consists of two different Cu2+(Zn2+) environments in the polymeric structure. Thermal decomposition of compounds 1 and 2 results in ZnMoO4 with similar specific surface area and morphology. The ZnMoO4 samples prepared from compounds 1 and 2 and compound 2 in itself are active photocatalysts in the degradation of Congo Red dye. IR, Raman, and UV studies on compounds 1@2H2O and 2 are discussed in detail.
Zanthoxylum Species: A Comprehensive Review of Traditional Uses, Phytochemistry, Pharmacological and Nutraceutical Applications
Authors: Okagu Innocent Uzochukwu , Ndefo Joseph Chinedu , Aham Emmanuel Chigozie , Udenigwe Chibuike C.
Published: July 2021

Zanthoxylum species (Syn. Fagara species) of the Rutaceae family are widely used in many countries as food and in trado-medicinal practice due to their wide geographical distribution and medicinal properties. Peer reviewed journal articles and ethnobotanical records that reported the traditional knowledge, phytoconstituents, biological activities and toxicological profiles of Z. species with a focus on metabolic and neuronal health were reviewed. It was observed that many of the plant species are used as food ingredients and in treating inflammation, pain, hypertension and brain diseases. Over 500 compounds have been isolated from Z. species, and the biological activities of both the plant extracts and their phytoconstituents, including their mechanisms of action, are discussed. The phytochemicals responsible for the biological activities of some of the species are yet to be identified. Similarly, biological activities of some isolated compounds remain unknown. Taken together, the Z. species extracts and compounds possess promising biological activities and should be further explored as potential sources of new nutraceuticals and drugs.
Effect of Modification on the Fluid Diffusion Coefficient in Silica Nanochannels
Authors: Chen Gengbiao , Liu Zhiwen
Published: July 2021

The diffusion behavior of fluid water in nanochannels with hydroxylation of silica gel and silanization of different modified chain lengths was simulated by the equilibrium molecular dynamics method. The diffusion coefficient of fluid water was calculated by the Einstein method and the Green–Kubo method, so as to analyze the change rule between the modification degree of nanochannels and the diffusion coefficient of fluid water. The results showed that the diffusion coefficient of fluid water increased with the length of the modified chain. The average diffusion coefficient of fluid water in the hydroxylated nanochannels was 8.01% of the bulk water diffusion coefficient, and the diffusion coefficients of fluid water in the –(CH2)3CH3, –(CH2)7CH3, and –(CH2)11CH3 nanochannels were 44.10%, 49.72%, and 53.80% of the diffusion coefficients of bulk water, respectively. In the above four wall characteristic models, the diffusion coefficients in the z direction were smaller than those in the other directions. However, with an increase in the silylation degree, the increased self-diffusion coefficient due to the surface effect could basically offset the decreased self-diffusion coefficient owing to the scale effect. In the four nanochannels, when the local diffusion coefficient of fluid water was in the range of 8 Å close to the wall, Dz was greater than Dxy, and beyond the range of 8 Å of the wall, the Dz was smaller than Dxy.
Silver Nanoparticle-Based Sensor for the Selective Detection of Nickel Ions
Authors: Rossi Andrea , Zannotti Marco , Cuccioloni Massimiliano , Minicucci Marco , Petetta Laura , Angeletti Mauro , Giovannetti Rita
Published: July 2021

Silver nanoparticles (AgNPs) can be used as a surface plasmon resonance (SPR) colorimetric sensor; the correlation between the SPR phenomenon and the aggregation state of nanoparticle allows the real-time detection of a target molecule. Surface functionalization of NPs with proper molecular baits is often performed to establish the selectivity of the sensor. This work reports on the synthesis of AgNPs under reducing conditions and on the functionalization thereof with mercaptoundecanoic acid (11-MUA). UV-VIS Spectroscopy confirmed the formation of AgNPs, eliciting a surface plasmon absorption band (SPAB) at 393 nm that shifted to 417 nm upon surface coating. Dynamic light scattering was used to investigate the surface coatings; moreover, pelleted AgNPs@11MUA nanoparticles were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analyzers (EDX), and infrared spectroscopy to corroborate the presence of 11MUA on the surface. Most interestingly, the resulting AgNPs@11MUA selectively detected micromolar levels of Ni2+, also in the presence of other cations such as Mn2+, Co2+, Cd2+, Cu2+, Zn2+, Fe2+, Hg2+, Pb2+, and Cr3+.
Au@Ag Dendritic Nanoforests for Surface-Enhanced Raman Scattering Sensing
Authors: Huang Hung Ji , Shiao Ming-Hua , Lin Yang-Wei , Lin Bei-Ju , Su James , Lin Yung-Sheng , Chang Han-Wei
Published: July 2021

The effects of Au cores in Ag shells in enhancing surface-enhanced Raman scattering (SERS) were evaluated with samples of various Au/Ag ratios. High-density Ag shell/Au core dendritic nanoforests (Au@Ag-DNFs) on silicon (Au@Ag-DNFs/Si) were synthesized using the fluoride-assisted Galvanic replacement reaction method. The synthesized Au@Ag-DNFs/Si samples were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, reflection spectroscopy, X-ray diffraction, and Raman spectroscopy. The ultraviolet-visible extinction spectrum exhibited increased extinction induced by the addition of Ag when creating the metal DNFs layer. The pure Ag DNFs exhibited high optical extinction of visible light, but low SERS response compared with Au@Ag DNFs. The Au core (with high refractive index real part) in Au@Ag DNFs maintained a long-leaf structure that focused the illumination light, resulting in the apparent SERS enhancement of the Ag coverage.