bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental investigation of optical anisotropy of polymethyl methacrylate aligned by metal–organic framework via in situ polymerization and direct chain‐introduction
Authors: Wang Lele , Wei Shuli , Wang Xianling , Lu Yunqing , Zhou Xinhui , Wang Jin 
Published: April 2022

AbstractEncapsulating polymer materials into metal–organic frameworks (MOFs) is an effective strategy to enhance the optical anisotropy of polymers, by aligning the polymer chains within the ordered MOF channels. At present, the main methods to encapsulate polymers into the MOF channels are the in situ polymerization and the direct chain‐introduction. In this work, we use these two methods to incorporate and align polymethyl methacrylate (PMMA) chains in MOFs, and selectively remove the MOF template to obtain PMMAs. Through the experimental characterization of the encapsulation efficiency and the optical anisotropy, the fundamental difference and influence on the optical anisotropy of these two methods are analyzed. The results show that the adsorption capacity of PMMA chain encapsulated in the MOF channels via the in situ polymerization method is higher than that via the direct chain‐introduction method. Also, the morphology and structure of the isolated PMMA products are more regular and the optical anisotropy is stronger in the case of in situ polymerization.
Healable and reprocessable silica/poly(oxime‐urethane) composite elastomer with high mechanical robustness and exceptional damage‐tolerant capacity
Authors: Wang Hui , Xu Junhuai , Xing Dongming , Du Xiaosheng , Wang Haibo , Du Zongliang , Cheng Xu 
Published: April 2022

AbstractA new generation of elastomer is expected to incorporate exceptional healing, reprocessing, damage‐tolerant capacity and outstanding strength and toughness in view of a sustainable society. To search a suitable method to perfectly match the overall performance is yet a formidable challenge. Here, a thermal‐triggered self‐healing polyurethane composite elastomer was fabricated by crosslinking isocyanate terminated polyurethane with amidoxime‐modified silica particles. The rigid fillers (silica particles) can effectively dissipate energy under an external force. The prepared particles and elastomer were detailly characterized by various instruments. The developed elastomer (POUs@2SiPs) had great tensile strength (39.47 MPa), decent elongation at break (1056.51%), excellent toughness (170.58 MJ m−3) and outstanding fracture energy (81.14 KJ m−2). Meanwhile, the well‐designed healing capability enabled the material to regain its original mechanical performance and integrity after damage. In addition, the reprocessibility granted material reusability to extend the service lifespan. This work is supposed to provide a meaningful strategy for developing the elastomer, which can effectively balance those conflict properties of mechanical strength, damage‐tolerant capacity and self‐healing.
Atomic Fe−N Doped Multi‐Cavity Hollow Carbon Nanoreactor as an Efficient Electrocatalyst for Lithium‐Sulfur Batteries
Authors: Shi Haodong , Su Panpan , Dong Cong , Liu Jian , Wu Zhong‐Shuai 
Published: April 2022

AbstractLithium‐sulfur (Li−S) batteries have been highly praised for the key rechargeable batteries due to their numerous advantages. However, the sluggish conversion and shuttling effect of polysulfides restrict their practicality. Here we rationally design the multi‐cavity hollow carbon spheres doped with atomic Fe−N sites (Fe−N/MCHCS) as physically/chemically double‐confined catalytic nanoreactors for the efficient sulfur host materials. The Fe−N/MCHCS with hierarchical porous structure and high pore volume ensures the high loading mass, and the multi‐cavity structures significantly buffer the volume expansion of sulfur and enhance the electronic contact. Meanwhile, atomic Fe offers chemical binding site and efficiently catalyzes the conversion of polysulfides during cycling, thus immobilizing and alleviating the shutting effect of polysulfides. Consequently, the Fe−N/MCHCS nanoreactor based Li−S batteries deliver a long cycling life of 1135 mAh g−1 after 300 cycles at 0.5 C and high‐rate capability of 1055 mAh g−1 at 8 C. Even under practical conditions with a high sulfur mass loading of 5.0 mg cm−2, a steady areal capacity of 4.85 mAh cm−2 is attained. This strategy combing multi‐cavity hollow carbon with single atom catalysis opens a reliable route to design highly stable and high‐performance Li−S batteries.
Hypernatremia in brain‐dead patients
Authors: Guo Weixin , Wang Shouhong , Wang Zhonghua , Hu Peihang , Wei Xuebiao , Liao Xiaolong 
Published: April 2022

AbstractObjectivesHypernatremia often occurs in patients with brain death. This study summarizes its characteristics.MethodsWe recorded 57 patient's highest blood sodium value, as well as daily NT‐proBNP, blood creatinine, and urine output. Further, we analyzed the time of the first rise in blood sodium, and the relationship between NT‐proBNP, serum creatinine, urine output, and serum sodium.ResultsThere was no hyponatremia in these patients, and only seven of the 53 patients registered blood sodium between 137 and 150 mmol/L. We found that blood sodium started to rise at 36.0 (28.5–52.3) h, reaching the highest value in 79.0 (54.0–126.0) h. Urine volume and creatinine have no correlation with serum sodium level, while NT‐proBNP has a significant correlation with serum sodium level.ConclusionIt is necessary to conduct volume assessments and urine electrolyte testing on patients with brain death. BNP has a protective effect on water and electrolytes to prevent hypernatremia.
Photocatalytic Biorefinery to Lactic Acid: A Carbon Nitride Framework with O Atoms Replacing the Graphitic N Linkers Shows Fast Migration/Separation of Charge
Authors: Ma Jiliang , Yang Xiaopan , Yao Shuangquan , Guo Yanzhu , Sun Runcang 
Published: April 2022

AbstractThe rational regulation of the structure of photocatalysts with an enhanced visible‐light absorption property and rapid charge dynamics is promising and challenging. Here, a facile method was developed for preparing oxygen‐doped carbon nitride bundles with porous hollow trunk‐shaped structures (Ox@CNB) using melamine with assistance of hydrochloric acid. Experimental results and density functional theory (DFT) calculations indicated that Ox@CNB exhibited controllable bandgaps (2.20–2.60 eV) and a low photoluminescence intensity. Interestingly, Ox@CNB displayed excellent photocatalytic activity for the synthesis of lactic acid (81.4 %) and universality for the reforming of biomass‐derived monosaccharides to lactic acid. The oxidation active species of h+, ⋅OH, ⋅O2− and 1O2 all promoted the lactic acid production, and h+ played a major role. A possible reaction mechanism of lactic acid synthesis was proposed by combining the experimental with the DFT results. A one‐thousand‐fold up‐scaled experiment demonstrated the significant application potential of the system for the industrial production of lactic acid.
Regulating Surface‐Interface Structures of Zn‐Incorporated LiAl‐LDH Supported Ru Catalysts for Efficient Benzene Hydrogenation to Produce Cyclohexene
Authors: Song Yihui , Sun Zhi , Fan Guoli , Yang Lan , Li Feng 
Published: April 2022

AbstractIn the heterogeneous catalysis, adsorption and desorption behaviors of reactants and products on the surface of catalysts can remarkably impact their catalytic activities and product selectivities. Here, series of Ru‐based catalysts supported on Zn‐incorporated Li−Al layered double hydroxides (Ru/LDH) were developed and employed in the selective benzene hydrogenation to produce cyclohexene without the use of any additional zinc salt additives. It was demonstrated that as‐constructed supported Ru catalyst bearing a Zn/(Li+Zn) molar ratio of 0.075 in the LDH support gave a higher cyclohexene yield of 43.2 % than those over other Ru‐based ones. Combining structural characterizations and catalytic hydrogenation reactions with temperature‐programmed desorption and in situ Fourier transform infrared spectroscopy of benzene and cyclohexene, it was revealed that the generation of appropriate surficial/interfacial Ru0/Ruδ+−O−Zn structures, as well as the existence of abundant hydroxyl groups on LDH supports, could facilitate the benzene adsorption and the cyclohexene desorption, thereby remarkably promoting the formation of cyclohexene. The present findings not only give a profound insight into the roles of surface‐interface structures of supported Ru catalysts for efficient benzene hydrogenation to produce cyclohexene but also simultaneously provide a promising guide to design high‐performance Ru‐based catalysts.
Palladium/Brønsted Acid Catalysis for Hydrofunctionalizations of Alkynes: From Tsuji‐Trost Allylations to Stereoselective Methodologies
Authors: Cera Gianpiero , Maestri Giovanni 
Published: April 2022

AbstractAlkynes are one of the most abundant feedstocks for chemical transformations. By merging palladium and Brønsted acid catalysts, they are converted into reactive allylmetal species, which become suitable for Tsuji‐Trost functionalizations with complete atom‐economy. This approach, which overcomes the limitations of traditional methods that suffer from the formation of over‐stoichiometric amounts of by‐products, has been disclosed for developing new C−C and C−Het bond forming methodologies. Within this review, we aim to survey the latest advancements in this area including applications in polymer chemistry, deuterium‐labeling and stereoselective catalysis.
Insights into Substituent Effects of Benzaldehyde Derivatives in a Heterogeneous Organocatalyzed Aldol Reaction
Authors: Di Carmine Graziano , Pesciaioli Fabio , Wang Simeng , Sinibaldi Arianna , Giorgianni Giuliana , Parlett Christopher M. A. , Carlone Armando , D'Agostino Carmine 
Published: April 2022

AbstractOrganocatalyst immobilization onto solid supports represents a promising method for enabling asymmetric organocatalysis while retaining the advantages of heterogeneous catalysts, including catalyst separation, recycling, and the use of fixed‐bed reactors. Understanding how such heterogenized catalytic systems work is fundamental to develop and tailor more efficient ones. Herein, we have elucidated the role of reactant molecular structure on surface interactions and reactivity for asymmetric aldol reactions between benzaldehyde derivatives and hydroxyacetone catalyzed by SBA‐15 immobilized L‐proline. NMR relaxation time analysis reveals that a stronger interaction between the aldehyde and the catalyst surface reduces catalytic reactivity, which is attributed to reduced access of hydroxyacetone to the L‐proline surface sites, hence inhibiting the formation of the enamine intermediate between hydroxyacetone and L‐proline. The results show that surface phenomena in these systems are important considerations for reactant selection, opening up new directions to explore in this area of research.
Investigating the Role of Sulfate Groups for the Binding of Gd3+ Ions to Glycosaminoglycans with NMR Relaxometry
Authors: Werner Patrick , Schuenke Patrick , Krylova Oxana , Nikolenko Heike , Taupitz Matthias , Schröder Leif 
Published: April 2022

AbstractGlycosaminoglycans (GAGs) are highly negatively charged macromolecules with a large cation binding capacity, but their interaction potential with exogeneous Gd3+ ions is under‐investigated. These might be released from chelates used as Gadolinium‐based contrast agents (GBCAs) for clinical MR imaging due to transmetallation with endogenous cations like Zn2+. Recent studies have quantified how an endogenous GAG sequesters released Gd3+ ions and impacts the thermodynamic and kinetic stability of some GBCAs. In this study, we investigate and compare the chelation ability of two important GAGs (heparin and chondroitin sulfate), as well as the homopolysaccharides dextran and dextran sulfate that are used as models for alternative macromolecular chelators. Our combined approach of MRI‐based relaxometry and isothermal titration calorimetry shows that the chelation process of Gd3+ into GAGs is not just a long‐range electrostatic interaction as proposed for the Manning model, but presumably a site‐specific binding. Furthermore, our results highlight the crucial role of sulfate groups in this process and indicate that the potential of a specific GAG to engage in this mechanism increases with its degree of sulfation. The transchelation of Gd3+ ions from GBCAs to sulfated GAGs should thus be considered as one possible explanation for the observed long‐term deposition of Gd3+ in vivo and related observations of long‐term signal enhancements on T1‐weighted MR images.
Children's shyness and frontal electroencephalogram delta–beta correlation in the pediatric surgical setting
Authors: Sriranjan Jhanahan , Chow Cheryl H.T. , Poole Kristie L. , Hassan Raha , Mirabelli James , Buckley Norman , Van Lieshout Ryan J. , Schmidt Louis A. 
Published: April 2022

AbstractThe prospect of surgery is a unique psychologically threatening context for children, often leading to experiences of preoperative anxiety. Recent research suggests that individual differences in children's temperament may influence responses to the surgical setting. In the present study, we examined whether individual differences in shyness were related to differences in frontal electroencephalogram (EEG) delta–beta correlation, a proposed neural correlate of emotion regulation and dysregulation, among children anticipating surgery. Seventy‐one children (36 boys, Mage = 10.3 years, SDage = 1.7 years) undergoing elective surgery self‐reported on their own shyness, and their parents also reported on their child's shyness. Using a mobile, dry sensor EEG headband, frontal EEG measures were collected and self‐ and observer‐reported measures of state anxiety were obtained at the children's preoperative visit (Time 1) and on the day of surgery (Time 2). A latent cluster analysis derived classes of low shy (n = 37) and high shy (n = 34) children using the child‐ and parent‐reported shyness measures. We then compared the two classes on frontal EEG delta–beta correlation using between‐ and within‐subjects analyses. Although children classified as high versus low in shyness had higher self‐ and observer‐reported state anxiety across both time periods, frontal EEG delta–beta correlation increased from T1 to T2 only among low shy children using a between‐subjects delta–beta correlation measure. We discuss the interpretation of a relatively higher delta–beta correlation as a correlate of emotion regulatory versus dysregulatory strategies for some children in a “real‐world,” surgical context.
Electrochemical Trifluoromethylselenolation of Activated Alkyl Halides
Authors: Grollier Kevin , Ghiazza Clément , Tlili Anis , Billard Thierry , Médebielle Maurice , Vantourout Julien C. 
Published: April 2022

AbstractA practical electrochemical method for the generation of CF3Se− anion from a shelf‐stable reagent (TsSeCF3) is reported allowing the metal‐free trifluoromethylselenolation of activated alkyl halides. Trifluoromethylselenolated compounds have been obtained in modest to excellent yields under the optimized reaction conditions. Finally, cyclic voltammetric and 19F NMR studies are presented and allowed to gain insight into the reaction mechanism.
Microsatellite mutation frequencies in river otters (Lontra Canadensis) from the Athabasca Oil Sands region are correlated to polycyclic aromatic compound tissue burden
Authors: Gyasi Helina , Curry Jory , Browning Jared , Ha Kelsey , Thomas Philippe J. , O'Brien Jason M. 
Published: April 2022

AbstractMining activities in the Athabasca oil sands region (AOSR) have contributed to an increase of polycyclic aromatic compounds (PACs) locally. However, many PACs found in the AOSR, and the combined effects of PAC mixtures have not been evaluated for genotoxicity in wildlife. Here, we examine whether mutation frequencies in AOSR river otters are correlated to PAC tissue burdens. We used single‐molecule polymerase chain reaction (SM‐PCR) to measure the mutant frequency of unstable DNA microsatellite loci in the bone marrow of wild river otters (n = 11) from the AOSR. Microsatellite mutation frequencies were regressed against liver PAC burden (total, low/high molecular weight [LMW/HMW], and parent/alkylated PACs), and to the distances from where the samples were collected to nearby bitumen upgraders. We found that microsatellite mutation frequency was positively correlated with total liver PAC burden. LMW and alkylated PACs were detected at higher levels and had a stronger positive relationship with mutation frequency than HMW (alkylated and parent) PACs. There were no significant relationships detected between mutation frequency and LMW parent PACs or the distance from bitumen upgraders. Furthermore, pyrogenic and petrogenic signatures suggest PACs in animals with high mutation frequencies were associated with combustion processes; although further investigation is warranted, due to limitations of diagnostic ratio determination with biotic models. Our findings support the hypothesis that PACs found in the AOSR increase mutation frequency in wildlife. Further investigation is required to determine if the elevated PAC levels associated with higher mutation frequency are due to natural exposure or elevated human activity.
Comparative thermoeconomic optimization and exergoenvironmental analysis of an ejector refrigeration cycle integrated with a cogeneration system utilizing waste exhaust heat recovery
Authors: Fazeli Atabak , Zandi Sina , Golbaten Mofrad Kamyar , Salehi Gholamreza , Khoshgoftar Manesh Mohammad Hassan , Shirmohammadi Reza 
Published: April 2022

AbstractTwo cogeneration cycles based on gas turbines have been compared by means of thermoeconomic and environmental analyses. The analyzed cogeneration systems are gas turbine, organic Rankine cycle (GT + ORC) and an integrated system including gas turbine, organic Rankine cycle, and ejector refrigeration cycle (GT + ORC + ERC). This work has focused on environmental considerations and thermoeconomic evaluation to decrease destruction cost and environmental impacts. The examination of cycles is conducted from energy, exergy, exergoeconomic, and exergoenvironmental (4E) perspectives. A computer MATLAB program is used to generate the simulation results, and the REFPROP 9.1 database is utilized to get thermodynamic properties of the working fluids. The use of the refrigeration evaporator in GT + ORC + ERC increased energy and exergy efficiencies. Multi‐objective optimization results indicate that the waste heat utilization in the trigeneration system is more effective in all aspects. In optimal conditions, the exergy efficiency and destruction cost of the GT + ORC + ERC system reached 40.76% and 151.95$ h−1, respectively. Moreover, optimization is performed by means of energy efficiency and destruction environmental impact as objective functions, and the optimum values are obtained at 30.67% and 46,918.30 mpts h−1, respectively.
Enantioselective Ecotoxicity of Venlafaxine in Aquatic Organisms: Daphnia and Zebrafish
Authors: Ribeiro Ondina , Félix Luís , Ribeiro Cláudia , Castro Bruno , Tiritan Maria Elizabeth , Monteiro Sandra Mariza , Carrola João Soares 
Published: April 2022

Abstract
Venlafaxine is a chiral antidepressant detected in aquatic compartments. It was recently included in the 3rd Watch List from the European Union. The present study aimed to investigate venlafaxine toxicity effects, targeting possible enantioselective effects, using two aquatic organisms, daphnia (Daphnia magna) and zebrafish (Danio rerio). Specimens were exposed to both racemate, (R,S)-venlafaxine (VEN), and to pure enantiomers. Acute assays with daphnia showed that up to 50 000 μg/L of the (R,S)-VEN induced no toxicity. Organisms were also exposed to sublethal concentrations (25–400 μg/L) of (R,S)-, (R)- and (S)-VEN, for 21 days. No significant effects on mortality, age at first reproduction, and size of the first clutch were observed. However, a decrease in fecundity was observed for both enantiomers at the highest concentration. Regarding zebrafish, the effects of venlafaxine on mortality, embryo development, behavior, biochemistry, and melanin pigmentation were investigated after 96 h of exposure to the range of 0.3–3000 μg/L. (R)-VEN significantly increased the percentage of malformations in comparison with (S)-VEN. Behavior was also enantiomer dependent, with a decrease in the total distance moved and an increase in avoidance behavior observed in organisms exposed to (R)-VEN. Despite the biochemical variations, no changes in redox homeostasis were observed. (R)-VEN also led to an increase in zebrafish pigmentation. The different susceptibility to venlafaxine and enantioselective effects were observed in zebrafish. Our results suggest that at environmental levels (R,S)-VEN and pure enantiomers are not expected to induce harmful effects in both organisms, but (R)-VEN increased malformations in zebrafish larvae, even at reported environmental levels. These results highlight the importance of including enantioselective studies for an accurate risk assessment of chiral pollutants. Environ Toxicol Chem 2022;41:1851–1864. © 2022 SETAC
Abstract
Venlafaxine (VEN) is a chiral antidepressant excreted by urine and/or leaked by inappropriate disposal and reach aquatic compartments. The present study investigated venlafaxine toxicity effects, targeting possible enantioselective effects, using daphnia (Daphnia magna) and zebrafish (Danio rerio) using several endpoints.
Evaluation and identification of morphological characters suitable for delimitation of Taraxacum species distributed in northeastern China
Authors: Jie Wu , Qun Liu , Cheng Haitao , Ning Wei , Cao Wei 
Published: April 2022

AbstractTaraxacum germplasm resources in northeastern China are not current and do not accurately reflect the actual distribution of the species. The objective of this study was to investigate the morphological traits of Taraxacum species distributed in northeastern China and identify those that will facilitate their classification in this region. Leaf, flower, and achene characteristics of 18 species were used for morphological classification. Scanning electron microscopy (SEM) was used to examine pollen morphology. Internal transcribed spacer (ITS) sequences were analyzed to determine sequence differences among the species and their utility in delimitation. Taxa were classified into groups based on their morphology. The ITS sequence analysis supported the taxon classification, but the genetic distances among the taxa did not reflect morphological differences. Phylogenetic analysis was used to divide the 18 species into three groups. Group I: T. coreanum (which has white flowers). Group Ⅱ: T. heterolepis, T. sinomongolicum, T. variegatum, T. asiaticum var. lonchophyllum, T. falcilobum, T. brassicaefolium, and T. erythropodium (outer involucre bracts, narrow membranous or nonmembranous). Group Ⅲ: T. formosanum, T. liaotungense, T. mongolicum, T. borealisinense, T. ohwianum, T. platypecidum, T. urbanum, T. antungense, T. asiaticum, and T. junpeianum (outer involucre bracts, broad membranous). The main taxonomic characteristics of Taraxacum floral organs and achene morphology.