bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lewis Pair Catalyzed Regioselective Polymerization of (E,E)‐Alkyl Sorbates for the Synthesis of (AB)n Sequenced Polymers
Authors: Zhao Wuchao , Li Fukuan , Li Chengkai , He Jianghua , Zhang Yuetao , Chen Changle 
Published: September 2021

AbstractIn this contribution, Lewis pairs (LPs) composed of N‐heterocyclic olefins (NHOs) with different steric hindrance and nucleophilicity as Lewis bases (LBs) and Al‐based compounds with comparable acidity but different steric hindrance as Lewis acids (LAs) were applied for 1,4‐selective polymerization of (E,E)‐methyl sorbate (MS) and (E,E)‐ethyl sorbate (ES). The effects of steric hindrance, electron‐donating ability, and acidity of LPs on MS and ES polymerization were systematically investigated. High catalytic activity and high initiation efficiency can be achieved, leading to the formation of PMS with 100 % 1,4‐selectivity, tunable molecular weight (Mw up to 333 kg mol−1), and narrow molecular weight distribution (MWD). Block copolymerization of ES and methyl methacrylate (MMA) was also realized. Meanwhile, this system can be applied to other homologous conjugated diene substrates. Furthermore, simple chemical reactions can efficiently convert PMS to different polymers with strict (AB)n sequence structures, such as poly(sorbic acid), poly(propylene‐alt‐methyl acrylate), poly(propylene‐alt‐acrylic acid), poly(propylene‐alt‐allyl alcohol), and poly(ethylene‐alt‐2‐butylene).
Recent advances in computational fluid dynamics simulation of flotation: a review
Authors: Wang Hainan , Yan Xiaokang , Li Danlong , Zhou Ruoqian , Wang Lijun , Zhang Haijun , Liu Qingxia 
Published: September 2021

AbstractFlotation process is a multi‐phase and multi‐scale complex flow system, in which hydrodynamics plays an indispensable role. In recent years, computational fluid dynamics (CFD) numerical simulation has gradually become a powerful tool for studying flotation. In this review, the theories of CFD numerical simulation in flotation research were reviewed, involving various turbulence models and multi‐phase flow simulation approaches. An attempt has been made to analyze and discuss the characteristics and applicability of different turbulence models and multi‐phase flow simulation approaches in flotation researches in detail. The CFD simulation of two commonly used flotation devices, that is, mechanically agitated flotation machine and flotation column, has been reviewed in detail. The detailed principles, operation, and hydrodynamic of flotation devices were discussed from the viewpoint of CFD. The advances made in CFD simulation for studying flotation process, including particle suspension, bubble dispersion, particle–bubble collision, attachment, and detachment subprocesses have been critically analyzed. Focused analysis was given on the influence mechanism of turbulence on the particle–bubble interactions. Finally, the gaps in the available literature are discussed and potential research directions are also proposed.
Fabrication and insights into the mechanisms of collagen‐based hydrogels with the high cell affinity and antimicrobial activity
Authors: Zhu Shichen , Yu Jiehang , Xiong Shanbai , Ding Yuting , Zhou Xuxia , Hu Yang , Chen Wenxin , Lin Yuanli , Dao Linrui 
Published: September 2021

AbstractIn this study, the adhesive collagen‐based hydrogels with antibacterial ability were prepared via arginine and dopamine modification, and the corresponding characterizations were also performed. A significant increase of N atom content from guanidine group was found via X‐ray photoelectron spectroscopy (XPS), suggesting the guanidine groups were successfully introduced into the systems. The XRD and FTIR patterns indicated that arginine and dopamine did not interrupt the intact triple‐helix conformation of collagen. Both the thermal stability and dynamic modulus of collagen hydrogels first increased and then decreased with the rising introduction of arginine. The increasing attachment of arginine retarded the further aggregations of collagen molecules due to the enhanced electrostatic repulsion, which was also confirmed by the microstructure observed by SEM. The antimicrobial activity of hydrogels modulus intensified significantly with the initial introduction of arginine (0.07 ~ 0.28 mM) (p < 0.05) via the measurements of inhibition zone diameter and OD260 value. However, the further addition of arginine did not result in the significant changes in the antibacterial performance. The biocompatibility of collagen hydrogels was not compromised, while the cell adhesiveness was improved. This work may provide a new strategy for the design of collagen‐based antibacterial hydrogels for the wound dressing applications.
A kelp‐inspired polyester fabric surface of UV grafted hydrogel for drag reduction
Authors: Dai Xianghui , Yu Xia , Zheng Jian , Yang Xiaoxu , Pan Jianjun , Zhang Xiaoting , Min Jie 
Published: September 2021

AbstractThe resorcinol diglycidyl acrylate (RDA) is firmly introduced to the surface of polyester (PET) fibers by a simple dip‐rolling and baking method, and a free radical polymerization reaction is initiated on the surface of PET fabrics under ultraviolet light (UV) light to obtain three hydrogel layers with different structure, including polyacrylamide (PAAM), polyacrylic acid (PAAC) and poly‐N‐isopropylacrylamide (PNIPAAM). It is shown that the pretreatment‐UV grafting method can be used to obtain hydrogel layers with porous structure on the surface of PET fabric, and all three hydrogel layers have better frictional properties than kelp. Among them, the friction coefficient of PET‐PAAM surface can reach 0.02, which is 17% of the friction coefficient of kelp surface and 83% lower than that of the untreated PET fabric surface, giving the PET fabric surface excellent interfacial drag reduction characteristics. It can be applied to the surface of underwater activity equipment as well as ships to improve moving efficiency and reduce energy consumption.
Modification of wood with copolymers based on glycidyl methacrylate and alkyl methacrylates for imparting superhydrophobic properties
Authors: Kolyaganova OlgaV. , Klimov Viktor V. , Bryuzgin Evgeny V. , Le Mahn D. , Kharlamov Valentin O. , Bryuzgina Ekaterina B. , Navrotsky Alexander V. , Novakov Ivan A. 
Published: September 2021

AbstractWood is an irreplaceable structural and biodegradable material, which is subject to swelling, shrinkage, significant deformation of structural elements, and products when its moisture content changes. This paper proposes wood surface modification with reactive copolymers based on glycidyl methacrylate and alkyl methacrylates to impart superhydrophobic properties with initial contact angles up to 166°. Scanning electron microscopy and energy dispersive X‐ray spectroscopy were used to study the features of polymer coating formation and to determine the modifier penetration depth, which was more than 1000 μm. It has been shown that copolymers do not fill the initial capillary system of wood. Modified wood is characterized by stable water‐repellent properties with low‐water diffusion rates, with the water absorption rate reduced by more than three times compared to that of initial wood. Polymer coatings provide water repellency, retain the appearance of original wood, and provide increased buoyancy.
Smoke suppression and thermal conductivity of epoxy resin modified byAl2O3and hyperbranched flame retardant
Authors: Qiao Huawei , Lin Xiuhuang , Zhong Wei , Lan Jiashui , Zhang Huagui , Chen Mingfeng 
Published: September 2021

AbstractIn this work, aluminum oxide (Al2O3) was added to hyperbranched flame retardant (PTDOB) modified epoxy resin (EP) system to develop a novel EP thermoset (Al2O3‐PTDOB/EP) with superior comprehensive performance. Al2O3‐PTDOB/EP exhibited excellent flame retardancy, smoke‐suppressing effects, and enhanced mechanical properties due to the crack pinning effects caused by the introduction of Al2O3. In detail, the limiting oxygen index (LOI) and UL‐94 rating of Al2O3‐PTDOB/EP‐3 reached 34.6% and V‐0 rating, respectively. Cone calorimeter test showed that the total heat release, total smoke production (TSP) and average effective heat of combustion of Al2O3‐PTDOB/EP‐3 were reduced by 14.5, 27.3 and 19.2% in comparison to PTDOB/EP, respectively. Furthermore, the impact, tensile and flexural strengths of Al2O3‐PTDOB/EP‐3 were significantly improved by 16.7 28.4 and 10.7%, respectively, because the addition of Al2O3provided the carbon layer barrier and crack pinning effect for the EP matrix. Moreover, thermal conductivity of Al2O3‐PTDOB/EP was also improved due to the excellent thermal conductivity of Al2O3, which had broadened its application in the field of electronic packaging.
Preparation and properties of nonionic waterborne epoxy resin
Authors: Wang Kaijie , Li Yuanyuan , Sang Shilin , Zhang Shijie , Chen Lilin , Tang Jialing 
Published: September 2021

AbstractMost waterborne epoxy resin emulsifiers are inactive, and the free emulsifier will precipitate out during the curing of the coating film, which will seriously affect the water resistance, solvent resistance, and hardness of the coating film. Herein we prepared a new type of nonionic active epoxy emulsifier. First, 1,4‐butanediol diglycidyl ether reacts with polyethylene glycol at a higher temperature to form an epoxy‐terminated modified hydrophilic segment. Then 2,4‐toluene diisocyanate link the hydrophilic segment and the epoxy resin E‐31 (according the reactivity of the hydroxyl group on the epoxy resin E‐31) to obtain an emulsifier for emulsifying epoxy resins. The synthesized emulsifier's cloud point is 89°C and hydrophilic–lipophilic balance is about 13.1. The most suitable condition of the phase inversion is that the emulsification temperature is 60°C and the stirring speed is 1500 r min−1. The coating films obtained from synthesized emulsifier is dense and uniform with excellent mechanical properties.
Heritage as an affective and meaningful information literacy practice: An interdisciplinary approach to the integration of asylum seekers and refugees
Authors: Le Louvier Kahina , Innocenti Perla 
Published: September 2021

AbstractInformation studies have identified numerous needs and barriers to the integration of asylum seekers and refugees; however, little emphasis has been placed thus far on their need to keep their own culture, values, and traditions alive. In this work, we use ethnographic constructivist grounded theory to explore the place of heritage in the information experience of people who have sought asylum in the United Kingdom. Based on our findings, we propose to conceptualize heritage as an affective and meaningful information literacy practice. Such conceptualization fosters integration by allowing people to simultaneously maintain their own ways of knowing and adapt to local ones. Our research approach provides scholars with a conceptual tool to holistically explore affective, meaningful, and cultural information practices. This study also reveals implications for policymakers, third sector organizations, and cultural institutions working toward the more sustainable integration of asylum seekers and refugees.
Design, Synthesis and Late‐Stage Modification of Indane‐Based Peptides via [2+2+2] Cyclotrimerization
Authors: Kotha Sambasivarao , Kumar Gupta Naveen , Sreevani Gaddamedi , Rao Panguluri Nageswara 
Published: September 2021

AbstractHere, we prepared several dipeptides containing 2‐aminoindane‐2‐carboxylic acid (Aic) and carried out further synthetic transformations. Synthesis and purification of modified peptides by using [2+2+2] cyclotrimerization is a challenging task. We are able to modify the unusual amino acids and peptide derivatives by late‐stage incorporation of benzylhalo functionality. To incorporate benzylhalo moiety we used [2+2+2] cyclotrimerization in the presence of Mo(CO)6. These halo derivatives are potential substrates for further modification by Sonogashira reaction, Suzuki–Miyaura cross‐coupling, sultine formation, and the Diels–Alder reaction sequence.
Supramolecular Enantiodifferentiating Photocyclodimerization of 2‐Anthracenecarboxylic Acid Mediated by Bridged β‐Cyclodextrins: Critical Effects of the Host Structure, pH and Co‐Solvents
Authors: Wang Xiaoqian , Ji Jiecheng , Rao Ming , Wu Wanhua , Yang Cheng 
Published: September 2021

AbstractSeveral sulfoxide‐ and sulfone‐bridged β‐cyclodextrin (CD) dimers were synthesized for mediating the enantiodifferentiating [4+4] photocyclodimerization of 2‐anthracenecarboxylic acid (AC). The complexation behavior of these chiral hosts with AC was investigated by UV‐vis, circular dichroism, fluorescence, and NMR spectroscopies and certified the formation of 1 : 1 and 1 : 2 host‐guest complexes. The product distribution and enantioselectivity of the photoreaction turned out to be a critical function of the chemical structure of bridged CDs. Comparing to the sulfur‐bridged 2AX−3GX β‐CD dimer 7, the conversion of the photolyzes with sulfoxide‐bridged was significantly improved, and the ee of cyclodimer 2 was remarkably increased from −82.8% with 7 to −96.7% with the sulfoxide‐bridged 2AX−3GX β‐CD dimer 8. The relative yields and ee values of the slipped cyclodimers 5 and 6 were greatly enhanced in the presence of 6 M CsCl. The reaction selectivity is susceptible to the pH variation of the aqueous buffer solution, demonstrating that the supramolecular photochirogenesis is controlled by multidimensional factors, including the chemical structure of the chiral host, solvent, and pH conditions.
Plasmonic Au‐Metal Oxide Nanocomposites for High‐Temperature and Harsh Environment Sensing Applications
Authors: Keerthana L. , Ahmad Dar Mushtaq , Dharmalingam Gnanaprakash 
Published: September 2021

AbstractNoble metal nanoparticles like Au have long been admired for their brilliant colour, significantly influenced by plasmon resonance. When embedded in metal oxides, they exhibit unique properties which make them an excellent choice for sensing in high‐temperature and harsh environment atmospheres. In this review, the various morphologies of Au nanoparticles (AuNPs) used in combination with metal oxides for sensing gases at temperatures greater than 300 °C are discussed. Theoretical discussions on the plasmon resonance properties of AuNPs as well as computational techniques like finite difference time domain (FDTD), are often used for understanding and correlating their extinction spectra and are briefed initially. The sensing properties of AuNPs embedded on a metal oxide matrix (such as TiO2, SiO2, NiO etc) for quantifying multiple analytes are then elucidated. The effect of high temperature as well as gas environments including corrosive atmospheres on such nanocomposites, and the different approaches to comprehend them are presented. Finally, techniques and methods to improve on the challenges associated with the realization and integration such Au‐metal oxide plasmonic nanostructures for applications such as combustion monitoring, fuel cells, and other applications are discussed.
A comprehensive distribution‐free scheme for tri‐aspect surveillance of complex processes
Authors: Mukherjee Amitava , Qiu Peihua , Marozzi Marco 
Published: September 2021

AbstractDistribution‐free charting schemes for process monitoring are more robust and reliable than their parametric counterparts when the process distributions are unknown and complicated. Most of the existing control charts are uni‐aspect schemes because they can detect a shift in only one aspect of the process distribution, like location or scale. Research on schemes for simultaneous surveillance of location and scale parameters has been very active in recent years, leading to many bi‐aspect schemes. These schemes do not explicitly deal with the shape of the process distribution. However, a shift in the shape parameter with or without a location or scale shift can occur in practice, especially in production or time‐to‐event processes. Note that there are nonparametric schemes for detecting general shifts based on goodness‐of‐fit test statistics or empirical likelihood ratio statistics, which cannot isolate if there is a shift in location, scale, shape, or combination of these parameters. This article introduces a new distribution‐free process monitoring scheme that can detect a shift in the location, scale or shape parameters, or any combinations of them. The new scheme is based on a combined statistic designed via Euclidean distance of the standardized Wilcoxon statistic for location, the standardized Ansari–Bradley statistic for scale, and the standardized Savage‐type statistic for shape. We discuss the implementation design using the average run‐length as the performance metric and investigate the proposed scheme's in‐control performance. It is shown that the new charting scheme is in‐control robust irrespective of the underlying process distribution and therefore applicable to monitor any univariate continuous processes. An out‐of‐control performance comparison study of the new scheme with many existing schemes shows that the new scheme is preferable to the existing schemes. We illustrate the proposed chart with real data to monitor a passenger train's arrival delays in Italy's regional route. The proposed scheme is comprehensive because it integrates the follow‐up procedure via integrated sub‐charts for classifying the signaling component.
Microbial production of hyaluronic acid: the case of an emergent technology in the bioeconomy
Authors: Ciriminna Rosaria , Scurria Antonino , Pagliaro Mario 
Published: September 2021

AbstractIn 1988 a novel fermentation route to high molecular weight hyaluronan mediated by Streptococcus zooepidemicus was first reported. In a few years, following rapidly expanding demand for hyaluronan as a key ingredient of facial dermal fillers, streptococcal production was commercialized, first in Western Europe and North America, and subsequently in China. Outlining the case for the microbial production of hyaluronan, an emergent technology in the bioeconomy, the purpose of this study is to further advance the field of sustainable, high‐added‐value, biobased production. The study recounts how this bioproduction actually developed, its advantages, and its current limitations. The research and educational outcomes of the study offer useful lessons to bioeconomy scholars and practitioners. © 2021 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Industrial Chemistry and John Wiley & Sons Ltd.
Bifunctionalized isotopologs as calibrants for standard‐free quantitation of drug metabolites in plasma by liquid chromatography coupled with radiometry and mass spectrometry
Authors: Gong Yong , Chen Jie , Lim Heng‐Keang , Weng Naidong , Salter Rhys 
Published: September 2021

AbstractThe reported method involves a novel workflow that eliminates the need for authentic reference standards for the quantitation of drug metabolites in biological samples using a single multi‐isotopically labeled compound bearing both radio and stable isotopes. The resulting radio and stable bifunctionalized isotopolog (RADSTIL) of the parent drug is employed as a substrate for in vitro biotransformation to targeted RADSTILs of metabolites as calibrants. Inclusion of a radio label enables both radiometric and mass spectrometric detection. The addition of stable labels ensures the subsequent isotopic interference‐free quantitation of unlabeled metabolites in preclinical and clinical samples. This affords a more accurate quantitation workflow compared with the current semi‐quantitation method, which utilizes isotopic interfering radio isotopologs of metabolites alone as calibrants. The proof‐of‐concept is illustrated with (14C,13C2)‐acetaminophen where in vitro biotransformation produced (14C,13C2)‐sulfate and (14C,13C2)‐glucuronide calibrants. Absolute quantitation of the acetaminophen metabolites was then achieved by liquid chromatography coupled with radiometry and mass spectrometry. Quantitative data obtained by this method fell within 82–86% of the values from conventional LC–MS/MS method.
Pharmacokinetic and metabolic analysis of an Alzheimer's disease therapeutic in rat serum via microfluidic CZE–MS
Authors: Kelley Zachary D. , Lovell Mark A. , Lynn Bert C. 
Published: September 2021

AbstractSensitive, high‐throughput methods for pharmacokinetic (PK) profiling are essential for potential therapeutics during critical stages of clinical trials. The application of a microfluidic capillary zone electrophoresis mass spectrometry (CZE–MS) method for PK profiling allows for rapid, sensitive and in‐depth analysis of multiple samples within a short timeframe. Here, a CZE–MS approach for PK analysis was compared with a traditional UHPLC–MS approach when analyzing serum extracts from rats treated with a potential Alzheimer's disease therapeutic, BNC‐1. Resulting PK data generated from both methods displayed statistical similarities. Additionally, the separation efficiency attributed to the use of the CZE–MS method provided substantial metabolic regulation data that was not apparent in the UHPLC–MS method. Additionally, the coupling of the CZE–MS method to the data processing software, MZmine2, was used to monitor changes in metabolism and observe putative BNC‐1‐derived metabolites. The ability to perform fast analyses without sacrificing sensitivity or metabolic information suggests that this CZE–MS method is ideal for metabolomics‐inclusive, high‐throughput PK profiling.
Ectodermal disturbance in development shared by anorexia and schizophrenia may reflect neurodevelopmental abnormalities
Authors: Remberk Barbara , Niwiński Piotr , Brzóska‐Konkol Ewa , Borowska Anna , Papasz‐Siemieniuk Anna , Brągoszewska Joanna , Bażyńska Anna Katarzyna , Szostakiewicz Łukasz , Herman Anna 
Published: September 2021

AbstractMinor physical abnormalities (MPA) are subtle dysmorphic features of bodily structures that have little or no impact on function. Most MPA develop during the first gestational trimester and are considered as important indicators of neuroectodermal deficiencies emerging during early brain development. A higher frequency of MPA was confirmed in schizophrenia patients and their relatives, when compared to controls. These findings are consistent with the neurodevelopmental model of schizophrenia. A neurodevelopmental component amongst other risk factors has also been recently proposed for anorexia nervosa (AN). The current study aimed to assess MPA frequency in adolescent inpatients with either schizophrenia spectrum disorders (SSD) or AN as compared to healthy controls (HC). The Waldrop Scale was used for assessing MPA. The mean MPA total score and mean head subscore was significantly higher in both test groups than in HC. There were no statistically significant differences between SSD and AN groups. The MPA profile (not frequency) was similar in all three groups. This finding is consistent both with widely acknowledged neurodevelopmental schizophrenia hypothesis as well as with more recent neurodevelopmental model of AN. Nevertheless, the findings should not be overgeneralized and further studies are warranted.