bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Characterization of Nanomaterias Using Scanning Electron Microscopy and Environmental Applications
Authors: OWOLABI DR JOSEPH 
Published: August 2022

Nano materials are classes of substances that have structural components smaller than 100nm and this includes nanoparticles with at least 2-D between 1 and 100nm in the Nano scale. Nano materials have small size which having at least 1-D 100nm or less. It can be Nano scale in 1-D, 2-D, or 3-D and exist in single, fused, aggregated forms with spherical, tubular and irregular shape. The samples of Nano materials were analyzed with scanning electron microscopy to provide images of Nano particles and their agglomerates in sufficient resolution that gives images of Nano materials with clearly identifiable particles. Nano materials have significant commercial impacts that can be increased in the future. Nano materials have good potential for developing the ways in which materials are generated that, the range and nature of functionalities can be accessed. Applications of Nano materials in the environment are different from one another depending on the type of devices used such as nanotechnologies in coatings for exterior surfaces, solar cells for renewable energy and de-colorization of dyes by the effect of Nano composites, medicine, textile, household, construction, chemical, automotive, electronics and engineering industries.
Laberiini, a new tribe of Tropiduchidae planthoppers from Madagascar (Hemiptera: Fulgoroidea)
Authors: Stroiński Adam , Bourgoin Thierry , Szwedo Jacek 
Published: August 2022

The tropiduchid monotypic genus Laberia Stål, 1866, endemic to Madagascar, is placed in a new tribe of its own Laberiini trib. nov. The tribe is placed in the subfamily Elicinae, and can be distinguished from other representatives of the subfamily by the unique combination of morphological characters of the head, tegmina, legs and genital structures. The genus Laberia and its only species Laberia palliata Stål, 1866 are redescribed, chresonymy is presented and nomenclatorial questions are clarified. Distributional data from Madagascar and doubtful presence of the taxon in Mauritius are discussed. Taxonomic content of Elicinae is briefly discussed.
Saudi Scientific Contribution to COVID-19 Published Research
Authors: Jahan Saulat , Al-Saigul Abdullah Mohammed , Kalevaru Chandra Sekhar 
Published: September 2022

Background: Credible scientific information plays a key role in the control of epidemics and pandemics.
Objectives: To determine the contribution of Saudi published research in Covid-19 scientific information as regards topics, study types, institutional and geographical distribution of Covid-19 research publications.
Methods: In this descriptive study, we conducted a literature search in Pubmed and Google Scholar by using the search terms: “Covid-19” OR “SARS-COV-2’’And “Saudi”. Abstracts of the articles were reviewed to identify relevant articles, and the data were analyzed using Epi Info statistical package.
Results: Out of the total 1,322 publications, 641 (48%) were review articles, 410 (31%) were original research articles and 195 (15%) were record-based clinical articles. Cross-sectional surveys comprised 84.6% of the original research; 57.9% of these surveys were conducted among the general population while 42.1% were among healthcare professionals. The highest proportion of publications was from universities (71%) and Riyadh (40.4%) province. The articles were published in 586 journals; among these 23 (3.9%) were Saudi journals.
Conclusion: Saudi researchers have made a significant contribution to COVID-19 publications. However, a scarcity of analytical and experimental studies was observed. Researchers need to focus on these study designs to better guide clinicians and policymakers for evidence-based guidelines and policies in the local context.
Supramolecular Assembly of Edge Functionalized Top‐Down Chiral Graphene Quantum Dots
Authors: Vázquez‐Nakagawa Mikiko , Rodríguez‐Pérez Laura , Martín Nazario , Herranz M. Ángeles 
Published: August 2022

AbstractThe construction of supramolecular assemblies of heterogeneous materials at the nanoscale is an open challenge in science. Herein, new chiral graphene quantum dots (GQDs) prepared by amidation reaction introducing chiral amide groups and pyrene moieties into the periphery of GQDs are described. The analytical and spectroscopic data show an efficient chemical functionalization and the morphological study of the supramolecular ensembles using SEM and AFM microscopies reveals the presence of highly ordered fibers of several micrometers length. Fluorescence studies, using emission spectroscopy and confocal microscopy, reveal that the fibers stem from the π‐π stacking of both pyrenes and GQDs, together with the hydrogen bonding interactions of the amide groups. Circular dichroism analysis supports the chiral nature of the supramolecular aggregates.
Diatomic Pd−Cu Metal‐Phosphorus Sites for Complete N≡N Bond Formation in Photoelectrochemical Nitrate Reduction
Authors: Sun Jie , Yang Hanxue , Gao Weiqi , Cao Tongcheng , Zhao Guohua 
Published: August 2022

AbstractThe synergistic effect of bimetallic heterogeneous catalysis in the reaction of nitrate reduction to nitrogen has been widely discussed, but it is still not clear how this effect works at the atomic scale, hindering the rational design of high‐performance catalysts. Here, for the first time, 2D phosphorene was used as a giant P ligand to confine high‐density PdCu dual‐atom to form a unique PdCuP4coordination structure, and this catalyst achieves 96.3 % NO3−removal rate and 95.2 % N2selectivity. In situ characterization combined with density functional theory (DFT) calculations show that the PdCu dual‐atom form covalent‐like bonds with adjacent P atoms, reducing the adsorption energy of the reactants. The synergistic effect of PdCu dual‐atom promotes the breaking of N−O bond, and the short bond length of ≈3 Å between PdCu atoms accelerates the transfer of NO2−, and eventually the two Pd−N adjacent to the surface of Pd rapidly combine to form N2.
A Thioether‐Catalyzed Cross‐Coupling Reaction of Allyl Halides and Arylboronic Acids
Authors: Xu Jingwei , He Zhiqi , Zhang Jiwei , Chen Jiean , Huang Yong 
Published: August 2022

AbstractC(sp3)−C(sp2) cross‐coupling reactions are an indispensable tool for organic synthesis. In these reactions transition metals have been extensively employed to promote the formation of valuable carbon‐carbon bonds. Herein, we report our recent discovery of a designer thioether as a highly active organocatalyst for reactions between an allyl bromide and an arylboronic acid. The cross‐coupling event occurred readily under mild condition in the presence of a weak inorganic base. Preliminary mechanistic studies suggested a sulfonium ylide mechanism.
Synthesis, Configurational Analysis, Molecular Recognition and Chirality Sensing of Methylene‐Bridged Naphthotubes
Authors: Wang Yan‐Fang , Yao Huan , Yang Liu‐Pan , Quan Mao , Jiang Wei 
Published: August 2022

AbstractMacrocyclic hosts with a well‐defined cavity are particularly appealing for supramolecular chemistry, but they are still rare. In this research, we reported a new class of macrocyclic hosts, namely methylene‐bridged naphthotubes, with well‐defined cavities. They were synthesized through TFA‐catalyzed Friedel–Crafts reactions between alkoxy‐substituted bisnaphthalenes and paraformaldehyde. A configurational selection was observed. Three‐membered macrocycles possess a single cavity, while four‐membered macrocycles adopt a double‐cavity conformation or a self‐filling conformation depending on the alkoxy length. The small homologue shows quite strong binding affinities (up to 108 M−1) to organic cations, which is better than structurally similar but flexible macrocycles. This demonstrates the advantage of a well‐defined cavity in molecular recognition. Moreover, these naphthotubes can be used as chirality sensors for chiral organic cations through different chirality transfer mechanisms.
Enantioselective Biocascade Catalysis with a Single Multifunctional Enzyme
Authors: Tseliou Vasilis , Faraone Adriana , Kqiku Laura , Vilím Jan , Simionato Gianluca , Melchiorre Paolo 
Published: August 2022

AbstractAsymmetric catalytic cascade processes offer direct access to complex chiral molecules from simple substrates and in a single step. In biocatalysis, cascades are generally designed by combining multiple enzymes, each catalyzing individual steps of a sequence. Herein, we report a different strategy for biocascades based on a single multifunctional enzyme that can promote multiple stereoselective steps of a domino process by mastering distinct catalytic mechanisms of substrate activation in a sequential way. Specifically, we have used an engineered 4‐oxalocrotonate tautomerase (4‐OT) enzyme with the ability to form both enamines and iminium ions and combine their mechanisms of catalysis in a complex sequence. This approach allowed us to activate aldehydes and enals toward the synthesis of enantiopure cyclohexene carbaldehydes. The multifunctional 4‐OT enzymes could promote both a two‐component reaction and a triple cascade characterized by different mechanisms and activation sequences.
Hybrid Germanium Bromide Perovskites with Tunable Second Harmonic Generation
Authors: Liu Yang , Gong Ya‐Ping , Geng Shining , Feng Mei‐Ling , Manidaki Despoina , Deng Zeyu , Stoumpos Constantinos C. , Canepa Pieremanuele , Xiao Zewen , Zhang Wei‐Xiong , Mao Lingling 
Published: August 2022

AbstractGe‐based hybrid perovskite materials have demonstrated great potential for second harmonic generation (SHG) due to the geometry and lone‐pair induced non‐centrosymmetric structures. Here, we report a new family of hybrid 3D Ge‐based bromide perovskitesAGeBr3,A=CH3NH3(MA), CH(NH2)2(FA), Cs and FAGe0.5Sn0.5Br3, crystallizing in polar space groups. These compounds exhibit tunable SHG responses, where MAGeBr3shows the strongest SHG intensity (5×potassium dihydrogen phosphate, KDP). Structural and theoretical analysis indicate the high SHG efficiency is attributed to the displacement of Ge2+along [111] direction and the relatively strong interactions between lone pair electrons of Ge2+and polar MA cations along thec‐axis. This work provides new structural insights for designing and fine‐tuning the SHG properties in hybrid metal halide materials.
Untersuchung der Ausziehtragfähigkeit von gewindeoptimierten Holzschrauben
Authors: Hölz Kevin , Bremer Frank , Giebel Maximilian , Matthiesen Sven 
Published: August 2022

AbstractDie Ausziehtragfähigkeit ist eine relevante Kenngröße für die Bemessung von Schrauben als Holzverbindungsmittel, sog. Holzschrauben. Diese wird, in Wechselwirkung mit den Holzeigenschaften, durch die Gewindegeometrie der Holzschraube beeinflusst. Bisherige Untersuchungen konnten die Einflüsse der Gewindeparameter auf die Ausziehtragfähigkeit noch nicht hinreichend ermitteln, um eine konstruktive Optimierung des Gewindes zu ermöglichen. In Versuchen mit Gewinde‐Testobjekten, welche gerade Gewindeflanken besitzen, konnte der Einfluss verschiedener Gewindeparameter auf die Tragfähigkeit ermittelt werden. Allerdings ist die Übertragbarkeit auf Holzschrauben bislang nicht untersucht worden. In diesem Beitrag wird die Untersuchung dieser Übertragbarkeit vorgestellt. Dazu wurden auf Basis der Ergebnisse zu den Gewinde‐Testobjekten zwei bezüglich der Ausziehtragfähigkeit optimierte Gewindegeometrien entworfen. Um die Übertragbarkeit der Ergebnisse zu prüfen, werden die Ausziehtragfähigkeiten von zwei Holzschraubenvarianten mit optimierten Gewindegeometrien, mit einer Referenzvariante sowie einer kommerziellen Holzschraube verglichen. Die zwei optimierten Holzschraubenvarianten weisen signifikant höhere Ausziehtragfähigkeiten gegenüber der Referenzvariante sowie der kommerziellen Schraubenvariante auf. Damit wird gezeigt, dass die Erkenntnisse der Gewinde‐Testobjekte übertragbar sind. Hersteller können diese daher zur Optimierung der Holzschraubengeometrie nutzen.
Facile spectrofluorimetric quantitation of octreotide, a synthetic peptide, in its pure form and pharmaceutical formulation; evaluation of the method’s greenness
Authors: Attia Tamer Z. , Abdulrazik Shrouk G. , Derayea Sayed M. 
Published: August 2022

AbstractA new, rapid, highly sensitive, and affordable spectrofluorimetric approach has been constructed and validated for the determination of octreotide in its authentic form and pharmaceutical dosage form. Octreotide is an important synthetic analog of the naturally occurring somatostatin hormone. The developed spectrofluorimetric approach is actually dependent on the measurement of octreotide native fluorescence at emission wavelength of 342 nm after excitation at 218 nm. At optimal reaction conditions, the calibration curve has been constructed over the concentration range 200–2000 ng ml−1, with excellent linearity. The limits of detection and quantitation values were found to be 55 and 169 ng ml−1, respectively. The developed approach has been effectively used to determine octreotide in its pharmaceutical ampoules, without interference from the excipients in the dosage form. The developed approach is simple, time‐saving, and does not require multiple pretreatment steps for samples, costly apparatus, or dangerous materials. As a result, it can be used to detect and quantify octreotide acetate in quality control laboratories.
Improvement of multicatalytic properties of nitrilase from Paraburkholderia graminis for efficient biosynthesis of 2‐chloronicotinic acid
Authors: Tang Xiao‐Ling , Li Yu‐Yi , Mao Yue , Zheng Ren‐Chao , Zheng Yu‐Guo 
Published: August 2022

AbstractNitrilases are promising biocatalysts to produce high‐value‐added carboxylic acids through hydrolysis of nitriles. However, since the enzymes always show low activity and sometimes with poor reaction specificity toward 2‐chloronicotinonitrile (2‐CN), very few robust nitrilases have been reported for efficient production of 2‐chloronicotinic acid (2‐CA) from 2‐CN. Herein, a nitrilase from Paraburkholderia graminis (PgNIT) was engineered to improve its catalytic properties. We identified the beneficial residues via computational analysis and constructed the mutant library. The positive mutants were obtained and the activity of the “best” mutant F164G/I130L/N167Y/A55S/Q260C/T133I/R199Q toward 2‐CN was increased from 0.14 × 10−3 to 4.22 U/mg. Its reaction specificity was improved with elimination of hydration activity. Molecular docking and molecular dynamics simulation revealed that the conformational flexibility, the nucleophilic attack distance, as well as the interaction forces between the enzyme and substrate were the main reason alternating the catalytic properties of PgNIT. With the best mutant as biocatalyst, 150 g/L 2‐CN was completely converted, resulting in 2‐CA accumulated to 169.7 g/L. When the substrate concentration was increased to 200 g/L, 203.1 g/L 2‐CA was obtained with yield of 85.7%. The results laid the foundation for industrial production of 2‐CA with the nitrilase‐catalyzed route.
Use of a 3D inkjet‐printed model to access dust particle toxicology in the human alveolar barrier
Authors: Kang Dayoon , Lee Hyomin , Jung Sungjune 
Published: August 2022

AbstractFine dust particles in the air travel into our body via the airway tract and cause severe respiratory diseases. Thus, the analysis of the effects of dust particles on the respiratory system has been receiving significant research interest. However, most studies on the toxicity of dust particles involve two‐dimensional (2D) cell cultures, animal models, and epidemiology. Here, we inkjet‐printed a three‐dimensional (3D) alveolar barrier model to study how dust particles cause respiratory diseases. The three‐layered in vitro model was exposed to A2 fine test dust with varying concentrations and exposure durations. The results highlighted the destruction of the tissue architecture along with apoptosis in the bioprinted alveolar barrier. The damage at the cellular level induced an increase in the amount of pro‐inflammatory cytokines secreted, followed by triggering of the signal transduction pathway and activation of transcription factors. As a consequence of the release of cytokines, the extracellular matrix was degraded, which led to the collapse of the cell structure, loss of cell polarity, and a decrease in barrier tightness. Further, the pulmonary surfactant protein‐related genes in the dust‐treated alveolar tissue were investigated to evaluate the possible role of dust particles in pulmonary surfactant dysfunction. This study demonstrated the use of 3D‐printed tissue model to evaluate the physiological impact of fine dust particles on cytotoxicity, alveolar barrier rigidity, and surfactant secretion of an alveolar barrier.
Differential metabolic profiles of ginsenosides in artificial gastric juice using ultra‐high‐pressure liquid chromatography coupled with linear ion trap‐Orbitrap mass spectrometry
Authors: Huang Juan , Gong Ming Jiong , Bai Jun Qi , Su He , Gong Lu , Huang Zhi Hai , Qiu Xiao Hui , Xu Wen , Zhang Jing 
Published: August 2022

AbstractGinsenosides have poor oral bioavailability and undergo rapid biological transformation in the complex gastrointestinal environment. Most studies on the metabolism of ginsenosides have focused on gut bacteria, yet gastric juice remains a nonnegligible factor. Metabolic profiles of ginsenoside monomers formed in artificial gastric juice were separately investigated and qualitatively identified using ultra‐high‐pressure liquid chromatography coupled with linear ion trap‐Orbitrap mass spectrometry (UHPLC‐LTQ‐Orbitrap MSn). A common pattern of their metabolic pathways was established, showing that ginsenosides were transformed via deglycosylation, hydration, and dehydration pathways. Two major structure types, 20(S), 20(R)‐protopanaxatriols and 20(S), 20(R)‐protopanaxadiols, basically shared similar transformation pathways and yielded deglycosylated, hydrated, and dehydrated products. Fragmentation patterns of major ginsenosides were also discussed. Consequently, gastric juice, as the primary link in ginsenoside metabolism and as important as the intestinal flora, produces considerable amounts of degraded ginsenosides, providing a partial explanation for the low bioavailabilities of primary ginsenosides.
Finite Element Analysis of Joints, Comparison of Results with the Component Method According to EN 1993‐1‐8:2005
Authors: Gómez Pablo , Gómez Amaya , Assis Paula 
Published: August 2022

SummaryThe current standards are based on the well‐known component method for the design of steel structure connections. This method proposes to analyse the joints as a set of more basic components. Its main drawback is the difficulty in extrapolating the method to perform the analysis of complex joints. As an alternative, it is possible to test the joints in the laboratory or to carry out finite element modelling. The purpose of this study is to compare the strength obtained on the basis of the Eurocode 3 criteria with the strength obtained from finite element models of two‐dimensional elements in order to validate a model which, a priori, is less accurate than the three‐dimensional element model.
Pedestrian & Cycling Bridge Over Calouste Gulbenkian Avenue, Lisbon – Conception, Design & Detailing
Authors: Fernandes Manuel Pera , Possolo Rafael 
Published: August 2022

ResumoThis article is about the general conception and design of a pedestrian and cycling viaduct in urban landscape, and its constraints characteristic of this kind of bridge, particularly concerning the positioning of the bridge, depending on topography and existing infrastructures, and the respective construction sequence.
A Novel Optimised Inter‐Locking Connection for Steel Modular Building Systems to Enable Reuse
Authors: Corfar Dan‐Adrian , Tsavdaridis Konstantinos Daniel 
Published: August 2022

AbstractA new inter‐module connection was developed, adopting structural topology optimisation (STO) and the inter‐locking method of joining. The structural performance of the connection was assessed through a series of monotonic and cyclic FE analyses. Results revealed that the structural behaviour of the new connection was comparable to that of other inter‐module joints in the literature, while managing to tackle their limitations by introducing both an easy‐to‐install and easy‐to‐disassemble configuration with promising opportunities for reuse, demonstrating that inter‐locking joints can be worthy competitors for traditional means of attachment in the future of modular construction.
Mechanical Performance of 17‐4PH Stainless Steel Produced Via Selective Laser Melting
Authors: Andreacola Francesca R. , Capasso Ilaria , Pilotti Letizia , Brando Giuseppe 
Published: August 2022

AbstractAdditive manufacturing is a production process in which elements and parts are created by depositing material layer‐by‐layer. Thanks to the rapid development of 3D printing methods, the most common metals typically used in engineering can also be employed to produce elements with outstanding structural properties. This paper shows the main outcomes of an experimental campaign focused on the mechanical characterisation of the 17‐4PH stainless steel, one of the metallic materials most widely used for Selective Laser Melting (SLM). Tensile tests, carried out to evaluate the mechanical properties of the material, are presented. Also the effect of annealing heat treatment on the residual stresses and the amount of residual austenite is discussed.
Complexe Sportive de Meudon – Structural Design and Construction
Authors: de Sousa João Faria , Neves Nuno 
Published: August 2022

AbstractThe “Complexe Sportive de Meudon” is a multisport venue in Trivaux – Paris, France, with a rectangular footprint of about 110 meters long by 70 meters wide. It includes an ice rink with 700No. seating places, a fitness centre, squash and padel courts, a climbing wall, and a full size 11‐aside football field, along with public and private parking space. The building's roof is entirely occupied by the football field, which is netted all around with a stainless‐steel cable mesh supported on discrete vertical steel elements, resembling “tuning forks”. A substantial part of the roof structure is supported off 12No. 45m long, varying depth plate girders, weighing 30tonnes each. This communication is focused on this part of the building's structure.
Fatigue Analysis of a Twin‐Girder Steel‐Concrete Railway Viaduct Based on the Master S‐N Curve Method
Authors: Alencar Guilherme S. , da Silva José Guilherme S. , de Jesus Abílio , Calçada Rui 
Published: August 2022

AbstractIn a recent research paper, Alencar et al. [1] demonstrated that the Master S‐N curve method (ASME) is also applicable for the fatigue analysis of welded bridge details. Thus, in this paper a methodology based on the Master S‐N curve for the fatigue analysis of welded railway bridges subjected to the railway traffic is proposed. A finite element model of a twin‐girder steel‐concrete railway viaduct over the river Sado was developed. The benefits of the proposed methodology are highlighted, such as the possibility to use a single S‐N curve.