bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of graphene structure/polyurethane membrane in pervaporative desulfurization
Authors: Peng Ping , Lan Yongqiang , Zhang Qinman , Luo Juxiang 
Published: August 2021

AbstractPervaporation (PV) desulphurization based on membrane technology has a great perspective for sulfur removal from transportation fuels. Herein, a unique two‐dimensional structure material–graphene egg yolk‐shell nanostructure (GYSNs) with high‐specific surface area and high dispersibility was prepared. In addition, the resultant GYSNs was incorporated into polyurethane (PU) matrix to fabricate mixed matrix membranes (MMMs). The MMMs were adopted to permselectively pervaporate thiophene with a thiophene/n‐octane solution as the model gasoline system and presented an elevated overall desulfurization performance as compared to the pristine PU membrane. Effects of GYSNs loading and operational variables including feed sulfur concentration, feed temperature, and operating time on the desulfurization performance were discussed. It was found that the MMMs with 0.8 wt% GYSNs loading had a permeation flux of 1411 g·m−2·h−1 and an enrichment factor of 4.32 at 303 K for PV desulfurization of a 1312 ppm thiophene/n‐octane mixture. Noteworthy was that the as‐fabricated MMMs displayed long‐term operation stability. This is a positive step forward for practical applications of MMMs in gasoline desulfurization.
Study of theself‐healingproperties of agedasphalt‐binderregenerated using residualsoybean‐oil
Authors: Zhang Xiaorui , Zhou Xinxing , Zhang Fan , Ji Wei , Otto Frédéric 
Published: August 2021

AbstractTo improve the self‐healing properties and reduce the reaction energy barrier during the self‐healing process of aged asphalt‐binders, this study utilized residual oil extracted from soybean to regenerate the aged asphalt‐binder and enhance its rheological properties including the self‐recovery potential. The self‐healing properties from the reaction energy barrier and chemical structure were characterized using molecular dynamic simulations. In addition, the rheological properties were measured and quantified using the dynamic shear rheometer test device. From the study results, the least reaction energy (30.16 kcal·mol−1) barrier registered during the self‐healing process of the regenerated asphalt‐binder occurred at 5.8 wt% residual Soybean‐oil, and was thus, deemed as the optimum oil content. The results further indicated that the residual soybean‐oil had a significant influence on the spatial configuration of the molecules in the aged asphalt‐binder, particularly on the saturates and aromatics components. Overall, the study findings indicated that residual Soybean‐oil can potentially reduce the reaction energy barrier of aged asphalt‐binders and enhance the self‐healing properties including fatigue life.
Highly Dispersed CoNi Alloy Embedded in N‐doped Graphitic Carbon for Catalytic Transfer Hydrogenation of Biomass‐derived Furfural
Authors: Wu Jun , Yan Xinyue , Wang Wenrui , Jin Ming , Xie Yuhang , Wang Chengbing 
Published: August 2021

AbstractThe development of efficient, stable, and cost‐effective heterogeneous catalysts for catalytic transfer hydrogenation (CTH) of biomass‐derived furfural (FAL) is highly desired. Herein, series of N‐doped graphitic carbon embedded CoNi bimetallic alloy nanoparticles were fabricated and used for the CTH of FAL to value‐added furfuryl alcohol (FOL) with renewable isopropanol as hydrogen donor. Intrinsic catalytic activity examination indicated the catalytic performance of NixCoy@NGC (x:y=1 : 3, 1 : 1, 3 : 1) nanocatalysts were sensitive to their chemical compositions. The optimal Ni1Co1@NGC nanocatalyst with Ni/Co mole ratio of 1 : 1 afforded a largest FOL yield of 89.3% with nearly full conversion of FAL. The synergistic effect enabled by bimetallic alloys and the abundant N‐based Lewis base sites and surface Co−N active species were revealed based on systematic structural characterization, responsible for the excellent catalytic efficiency of bimetallic Ni1Co1@NGC nanocatalyst for CTH of FAL.
Synthesis of Conjugated Polymers via Transition Metal Catalysed C−H Bond Activation
Authors: Chua Ming Hui , Png Zhuang Mao , Zhu Qiang , Xu Jianwei 
Published: August 2021

AbstractTransition metal catalysed C−H bond activation chemistry has emerged as an exciting and promising approach in organic synthesis. This allows us to synthesize a wider range of functional molecules and conjugated polymers in a more convenient and more atom economical way. The formation of C−C bonds in the construction of pi‐conjugated systems, particularly for conjugated polymers, has benefited much from the advances in C−H bond activation chemistry. Compared to conventional transition‐metal catalysed cross‐coupling polymerization such as Suzuki and Stille cross‐coupling, pre‐functionalization of aromatic monomers, such as halogenation, borylation and stannylation, is no longer required for direct arylation polymerization (DArP), which involve C−H/C−X cross‐coupling, and oxidative direct arylation polymerization (Ox‐DArP), which involves C−H/C−H cross‐coupling protocols driven by the activation of monomers’ C(sp2)−H bonds. Furthermore, poly(annulation) via C−H bond activation chemistry leads to the formation of unique pi‐conjugated moieties as part of the polymeric backbone. This review thus summarises advances to date in the synthesis of conjugated polymers utilizing transition metal catalysed C−H bond activation chemistry. A variety of conjugated polymers via DArP including poly(thiophene), thieno[3,4‐c]pyrrole‐4,6‐dione)‐containing, fluorenyl‐containing, benzothiadiazole‐containing and diketopyrrolopyrrole‐containing copolymers, were summarized. Conjugated polymers obtained through Ox‐DArP were outlined and compared. Furthermore, poly(annulation) using transition metal catalysed C−H bond activation chemistry was also reviewed. In the last part of this review, difficulties and perspective to make use of transition metal catalysed C−H activation polymerization to prepare conjugated polymers were discussed and commented.
Moment‐based analysis of pinning synchronization in complex networks
Authors: Xiang Linying , Yu Yanying , Zhu Jiawei 
Published: August 2021

AbstractIn this paper, pinning synchronization of complex networks is investigated from a moment‐based analysis approach. The analytical expressions for the first three expected moments of the coupling and control matrix for an ER random graph, a Chung‐Lu random network, and an NW small‐world network are derived, respectively. The shape of the eigenvalue distribution of the coupling and control matrix can be estimated based on the obtained expected moments and thus used to predict pinning synchronization in the network. It is shown that the expected moments are associated with the local structural properties of the network and the control mechanism. This allows us to bound the smallest and largest eigenvalues of the spectral distribution without computing the Laplacian eigenvalues of a large‐scale network. Numerical simulations of the above three representative networks composing of chaotic systems, respectively, are shown for illustration and verification.
Front‐line treatment patterns in multiple myeloma: An analysis of U.S.‐based electronic health records from 2011 to 2019
Authors: Kumar Shaji , Williamson Mellissa , Ogbu Uzor , Surinach Andy , Arndorfer Stella , Hong Wan‐Jen 
Published: August 2021

AbstractMultiple myeloma (MM) treatment options have evolved rapidly, but how new agents are incorporated into treatment decisions in current practice is not well understood. This study examined prescribing trends of physicians treating newly diagnosed MM and treatment outcomes in the United States. Electronic health record data from 6271 adult patients diagnosed with MM and receiving initial treatment between 1 January 2011 and 31 January 2020 were derived from the Flatiron Health electronic‐health record de‐identified database. The number/types of agents included in therapy regimens, time to next treatment (TTNT), and overall survival (OS) were assessed. Subgroups were analyzed by the International Staging System (ISS) disease stage at diagnosis, stem cell transplant eligibility and timing, and practice type. Exploratory prognostic models evaluated the association between baseline covariates and time‐to‐event outcomes. The proportion of patients receiving triplet therapies increased from 2011 (36%) to 2019 (72%) as those receiving initial monotherapy or doublet therapy decreased. Overall, the most prevalent triplet regimen consisted of an immunomodulatory drug (IMiD), a proteasome inhibitor, and a steroid. From 2017 to 2019, median TTNT from front‐line to second‐line was longer in patients with ISS stage I versus stages II/III, and in those receiving IMiD‐containing doublet or triplet therapies versus other combinations. Overall median OS was 56 months and increased from 2011 to 2014, after which median OS was not yet reached. Age, ISS stage, and high‐risk status were prognostic for both OS and TTNT, while sex, practice type, and ECOG status were prognostic for OS only.
Cost‐effectiveness of ipilimumab versus high‐dose interferon as an adjuvant therapy in resected high‐risk melanoma
Authors: Salans Mia , Courtney Patrick Travis , Yip Anthony , Murphy James D. 
Published: August 2021

AbstractBackgroundAdjuvant ipilimumab was found to improve the overall survival and reduce toxicity compared to high‐dose interferon (HDI) in patients with resected, high‐risk melanoma. However, the cost of ipilimumab is substantially higher than HDI. This study evaluates the cost‐effectiveness of ipilimumab as an adjuvant treatment in melanoma from a healthcare perspective.MethodsWe designed a Markov model simulating resected, high‐risk melanoma patients receiving either ipilimumab or HDI. Transition probabilities, including risks of survival, disease progression, and toxicity, were ascertained from clinical trial data. Costs and quality of life measurements (health utilities) were extracted from the literature. Incremental cost‐effectiveness ratios (ICERs), defined as incremental costs divided by incremental quality‐adjusted life‐years (QALYs), assessed cost‐effectiveness. ICERs <$100,000/QALY were deemed cost‐effective. We measured model uncertainty with one‐way and probabilistic sensitivity analyses.ResultsIn our base case model, ipilimumab increased costs by $107,100 and increased effectiveness by 0.43 QALY, yielding an ICER of $392,600/QALY. Our model was moderately sensitive to the costs of ipilimumab, though the cost of ipilimumab would need to decrease by 44% for ipilimumab to become cost‐effective compared to HDI. The model was not sensitive to survival, toxicity, or other costs. Probabilistic sensitivity analysis showed that HDI would remain the cost‐effective treatment option 96.2% of the time at a willingness‐to‐pay threshold of $100,000/QALY.ConclusionsAdjuvant ipilimumab increases the survival and decreases the toxicity compared to HDI in resected, high‐risk melanoma patients, though this would not be considered cost‐effective due to the high price of ipilimumab.
Two New Alkaloids from Fuzi and Their Metabolites Study
Authors: Liu Sisi , Deng Pei , Long Yihong , Yang Shushu , Zhu Junshuo , Li Kunsheng , Lai Changjiangsheng , Yang Weiran , Chen Jinlong 
Published: August 2021

AbstractFormer study suggests alkaloids from herbs of Aconitum genus plants possess excellent bioactivities, which exert great value for related deeper chemical constituent investigation. Herein, chemical isolation was performed and four alkaloids were isolated from Fuzi, of which two were new ones, and the other two were reported NMR data for the first time. Their chemical structures were identified by NMR data, high resolution MS, UV and IR analysis. Additionally, the MS fragmentation patterns were explored, formerly, that of hetisane alkaloid was rarely reported, and fragmentation mechanism of the diagnostic ion was proposed. Based on these fragment pathway, metabolites and metabolic pathways of four compounds were investigated in rat liver microsomes using UPLC−Q/TOF−MS, and dehydrogenation product was firstly found from metabolites of hetisane alkaloid.
Barks of Three Wild Pyrus Taxa: Phenolic Constituents, Antioxidant Activity, and in Vitro and in Silico Investigations of α‐Amylase and α‐Glucosidase Inhibition
Authors: Ušjak Ljuboš J. , Milutinović Violeta M. , Đorđić Crnogorac Marija J. , Stanojković Tatjana P. , Niketić Marjan S. , Kukić‐Marković Jelena M. , Petrović Silvana D. 
Published: August 2021

AbstractDry MeOH extracts of the twig barks of Pyrus communis subsp. pyraster, P. spinosa and their hybrid P.×jordanovii nothosubsp. velenovskyi, collected in wild in Serbia, were analyzed. By LC/MS, the contents of arbutin (99.9–131.0 mg/g), chlorogenic acid (2.2–6.3 mg/g), catechin (1.0–5.3 mg/g) and total dimeric and trimeric procyanidins (42.2–61.3 mg/g), including procyanidin B2 (8.9–17.2 mg/g), were determined. Colorimetrically, high contents of total phenolics (436.2–533.4 mg GAE/g) and tannins (339.4–425.7 mg GAE/g), as well as strong total antioxidant activities (FRAP values 4.5–5.9 mmol Fe2+/g), and DPPH (SC50=6.6–7.1 μg/ml) and hydroxyl radical (SC50=447.1–727.7 μg/ml) scavenging abilities were revealed. In vitro, all extracts exhibited notable inhibition of α‐amylase (IC50=310.8–617.7 μg/ml) and particularly strong inhibition of α‐glucosidase (IC50=2.1–3.7 μg/ml). Molecular docking predicted that among identified compounds procyanidin B2 is the best inhibitor of these carbohydrate‐digesting enzymes. Obtained results showed that the barks of investigated Pyrus hybrid and its parent taxa have similar composition and bioactivity.
Less is More: A Comprehensive Study on the Effects of the Number of Gas Diffusion Layers on Air–Cathode Microbial Fuel Cells
Authors: Sánchez‐Peña Pilar , Rodriguez Jesús , Montes Raquel , Baeza Juan Antonio , Gabriel David , Baeza Mireia , Guisasola Albert 
Published: August 2021

AbstractAir‐cathode microbial fuel cells (AC‐MFC) use a gas‐diffusion‐layer (GDL) coating based on polytetrafluoroethylene applied to the cathode to prevent electrolyte leakage. However, this type of GDL can also lead to a decrease in MFC performance due to electron‐transfer limitation, mass‐transfer limitation or catalyst availability. This study provides a comprehensive understanding of the significance of the GDL coating, demonstrating the interaction between the number of GDL coatings and the external resistance (Rext) used. An experimental design in 28 mL AC‐MFCs was prepared and conducted using two different Rext (10 and 249 Ω) and four different GDL coatings (1 to 4 layers). The coating effect was not significant when operating with a high Rext, where the electron transfer was the limiting process. However, when the Rext was low, the amount of polytetrafluoroethylene limited the cathode performance due to a significant decrease in the Pt availability on the catalytic surface. Thus, GDL‐1 with 10 Ω as Rext reached 0.96 mA/cm2, 3‐fold higher than that obtained with 249 Ω as Rext (ca. 0.30 mA/cm2). Besides, the current density did not vary noticeably in the other cathodes with 249 Ω as Rext. Contrarily, the current density with 10 Ω as Rext decreased as the number of GDL increased (0.74, 0.57 and 0.37 for GDL‐2, GDL‐3 and GDL‐4 respectively). These values agreed with those of the polarization curve. Furthermore, limitations were also observed in electrochemical impedance spectroscopy measurements: the charge resistance increased with the number of GDL, related to the ease of electron flow. These values were18 Ω, 22 Ω, 53 Ω and 58 Ω for GDL‐1, GDL‐2, GDL‐3 and GDL‐4, respectively, for both 10 and 249 Ω cathodes.
Application of Multinuclear MAS NMR for the in situ Monitoring of Hydrothermal Synthesis of Zeolites
Authors: Ivanova Irina I. , Kolyagin Yury G. 
Published: August 2021

AbstractIn situ MAS NMR studies on the monitoring of hydrothermal synthesis of zeolites are reviewed. The first part of the review contains information on the experimental techniques used for the in situ NMR studies in static and MAS conditions. In the second part, the main capabilities of the in situ 1H, 11B, 13C, 14N, 19F, 23Na, 27Al, 29Si and 31P MAS NMR for the elucidation of the mechanism of hydrothermal synthesis of zeolites are examined and the data on NMR lines identification are summarized. In the last part the main application areas of the techniques are considered and illustrated with examples taken from the mechanistic studies of zeolites A, X, MFI and BEA synthesis. A cross‐reference index between the materials studied, the experimental approaches used, the mechanistic information obtained, and the corresponding literature sources is established.
A Structural Diversity of Molecular Alkaline‐Earth‐Metal Polyphosphides: From Supramolecular Wheel to Zintl Ion
Authors: Yadav Ravi , Weber Martin , Singh Akhil K. , Münzfeld Luca , Gramüller Johannes , Gschwind Ruth M. , Scheer Manfred , Roesky Peter W. 
Published: August 2021

AbstractA series of molecular group 2 polyphosphides has been synthesized by using air‐stable [Cp*Fe(η5‐P5)] (Cp*=C5Me5) or white phosphorus as polyphosphorus precursors. Different types of group 2 reagents such as organo‐magnesium, mono‐valent magnesium, and molecular calcium hydride complexes have been investigated to activate these polyphosphorus sources. The organo‐magnesium complex [(DippBDI−Mg(CH3))2] (DippBDI={[2,6‐iPr2C6H3NCMe]2CH}−) reacts with [Cp*Fe(η5‐P5)] to give an unprecedented Mg/Fe‐supramolecular wheel. Kinetically controlled activation of [Cp*Fe(η5‐P5)] by different mono‐valent magnesium complexes allowed the isolation of Mg‐coordinated formally mono‐ and di‐reduced products of [Cp*Fe(η5‐P5)]. To obtain the first examples of molecular calcium‐polyphosphides, a molecular calcium hydride complex was used to reduce the aromaticcyclo‐P5ring of [Cp*Fe(η5‐P5)]. The Ca‐Fe‐polyphosphide is also characterized by quantum chemical calculations and compared with the corresponding Mg complex. Moreover, a calcium coordinated Zintl ion (P7)3−was obtained by molecular calcium hydride mediated P4reduction.
Enhanced Catalytic Performance of Quasi‐HKUST‐1 for the Tandem Imine Formation
Authors: Bagheri Minoo , Melillo Arianna , Ferrer Belen , Masoomi Mohammad Yaser , Garcia Hermenegildo 
Published: August 2021

AbstractCopper‐based metal‐organic framework (Cu3(BTC)2(H2O)3]n⋅nH2OMeOH (HKUST‐1) has been subjected to thermolysis under air atmosphere at different temperatures ranging from 100 to 300 °C. This treatment produces the partial removal of ligands, the generation of structural defects and additional porosity in a controlled way. The resulting defective materials denoted according to the literature as quasi‐MOFs, were subsequently employed as heterogeneous catalysts in the one pot synthesis of N‐benzylideneaniline from aniline and benzyl alcohol in open air as terminal oxidant at 70 °C under base‐ and dehydrating agent‐free conditions. The Q‐HKUST catalysts calcined at 240 °C (QH‐240) was the most efficient in the series, promoting imine synthesis. Data from Knoevenagel condensation of malononitrile shows that in QH‐240 the distances of Cu ions in HKUST‐1 cavities are preserved, increasing the Knoevenagel activity, but a strong rearrangement takes place at 300 °C or above. The unsaturated copper active sites with simultaneous presence of micro‐ and mesopores in QH‐240 are responsible for this excellent catalytic performance. The effective parameters on catalytic activity of QH‐240 including deligandation temperature, the amount of catalyst, the ratio of reactants, and reaction temperature as well as the stability and recyclability of the catalyst were also investigated. The possible mechanism used by QH‐240 follows alcohol aerobic oxidation and subsequent anaerobic condensation of aldehyde intermediate with aniline.
Comparative study of different chiral ligands for dynamic kinetic resolution of amino acids
Authors: Nagaoka Keita , Nakano Arina , Han Jianlin , Sakamoto Tsubasa , Konno Hiroyuki , Moriwaki Hiroki , Abe Hidenori , Izawa Kunisuke , Soloshonok Vadim A. 
Published: August 2021

AbstractDynamic kinetic resolution (DKR) of unprotected amino acids (AAs), via intermediate formation of Ni(II) complexes, is currently a leading methodology for preparation of natural and tailor‐made AAs in enantiomerically pure form. In this work, we conduct a comparative case study of synthetic performance of four different ligands in DKR of six AAs representing aryl‐, benzyl‐, alkyl‐, and long alkyl‐type derivatives. The results of this study allow for rational selection of ligand/AA type to develop a practical procedure for preparation of target enantiomerically pure AAs.
Visible‐Light‐Catalyzed N‐Radical‐Enabled Cyclization of Alkenes for the Synthesis of Five‐Membered N‐Heterocycles
Authors: Wang Hui‐Zhi , Li Jiao‐Zhe , Guo Zhiyong , Zheng Hongxing , Wei Wen‐Ting 
Published: August 2021

AbstractFive‐membered N‐heterocycles play an important role in organic synthesis and material chemistry, as they are widespread through pharmaceutical molecules and natural products. Chemists have developed many synthetic strategies for constructing five‐membered N‐heterocycles from N‐centered radicals, but the availability of mild and green methods for these transformations is still limited. The cyclization of visible‐light‐generated N‐centered radicals with alkenes has emerged as a powerful tool to enable these chemical transformations in recent years. Through chosen representative examples, the significant developments in this promising field were outlined, including the selection of catalysts, substrate scope, mechanistic understanding (especially density functional theory calculations), and applications. The contents of this Minireview are categorized by intramolecular cyclization and intermolecular N‐centered radical addition/cyclization reactions.
An equivalent electrical circuit for the Hindmarsh‐Rose model
Authors: Ochs Karlheinz , Jenderny Sebastian 
Published: August 2021

SummaryHardware realizations of neural networks can pave the way towards a new generation of processors due to the biological role model being superior in terms of speed and energy‐efficiency compared to today's processors. This can be achieved by deriving novel design principles for circuits being obtainable when replicating and investigating real biological neural networks in depth. This has, for example, been done by utilizing the Hindmarsh‐Rose model, offering a rich repertoire of neuronal firing patterns. Our aim is to synthesize a theoretical, equivalent electrical circuit of the Hindmarsh‐Rose model being well interpretable in terms of biology, since this supports the derivation of design principles from biology and can serve as a basis for a systematic circuit simplification. We do this by starting from a linearized model because this allows for a systematic approach and then first derive a linear and afterwards a nonlinear equivalent electrical circuit. The resulting circuit has a structure similar to conductance‐based models, where a deployed negative impedance converter can be seen as a deeper modeling of ion pump activity. Simulation results of the proposed circuits show the functionality of the equivalent circuits.