bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Designed α‐GalCer Analog Promotes Considerable Th1 Cytokine Response by Activating the CD1d‐iNKT Axis and CD11b‐Positive Monocytes/Macrophages
Authors: Ma Juan , He Peng , Zhao Chuanfang , Ren Quanzhong , Dong Zheng , Qiu Jiahuang , Jing Yang , Liu Sijin , Du Yuguo 
Published: June 2020

AbstractSelective helper T cell 1 (Th1) priming agonists are a promising area of investigation for immunotherapeutic treatment of various diseases. α‐galactosylceramide (α‐GalCer, KRN7000), a well‐studied Th1‐polarizer, simultaneously induces helper T cell 2 (Th2)‐type responses, which is a major drawback for its clinical applications. Based on surflex‐docking computation, α‐GalCer‐diol, with added hydroxyl groups in the acyl chain, is designed and synthesized. Structural analyses reveal stronger affinity between α‐GalCer‐diol and cluster of differentiation 1d (CD1d), leading to enhanced antigen presentation by dendritic cells (DCs) and self‐activation, as reflected by tight binding of the T‐cell receptor (TCR)/KRN7000/CD1d ternary complex and elevated production of interleukin 12 (IL‐12) and interferon‐γ (IFN‐γ). Consequently, invariant natural killer T cells (iNKTs) are activated and exhibit an improved Th1‐type cytokine profile ex vivo and in vivo. Different from KRN7000, α‐GalCer‐diol markedly boosts the expansion of the CD11b+ subpopulation and enhances IFN‐γ content in CD11b+ cells. These reinforced Th1‐type responses collectively endow α‐GalCer‐diol more robust antitumor activity in a xenograft animal model using B16‐F10 melanoma cells. Together, the data demonstrate a new mechanism through which α‐GalCer‐diol induces stronger Th1‐type responses by stimulating CD11b+ leukocyte expansion and DC‐conducted CD1d‐restricted and TCR‐mediated iNKT activation. Hence, this study may facilitate the development of novel Th1 priming agonists.
The Role of Tricellulin in Epithelial Jamming and Unjamming via Segmentation of Tricellular Junctions
Authors: Lohmann Sophie , Giampietro Costanza , Pramotton Francesca M. , Al‐Nuaimi Dunja , Poli Alessandro , Maiuri Paolo , Poulikakos Dimos , Ferrari Aldo 
Published: June 2020

AbstractCollective cellular behavior in confluent monolayers supports physiological and pathological processes of epithelial development, regeneration, and carcinogenesis. Here, the attainment of a mature and static tissue configuration or the local reactivation of cell motility involve a dynamic regulation of the junctions established between neighboring cells. Tricellular junctions (tTJs), established at vertexes where three cells meet, are ideally located to control cellular shape and coordinate multicellular movements. However, their function in epithelial tissue dynamic remains poorly defined. To investigate the role of tTJs establishment and maturation in the jamming and unjamming transitions of epithelial monolayers, a semi‐automatic image‐processing pipeline is developed and validated enabling the unbiased and spatially resolved determination of the tTJ maturity state based on the localization of fluorescent reporters. The software resolves the variation of tTJ maturity accompanying collective transitions during tissue maturation, wound healing, and upon the adaptation to osmolarity changes. Altogether, this work establishes junctional maturity at tricellular contacts as a novel biological descriptor of collective responses in epithelial monolayers.
Methanol as Hydrogen Source: Transfer Hydrogenation of Aldehydes near Room Temperature
Authors: Chen Zhenyu , Chen Guanhong , Aboo Ahmed H. , Iggo Jonathan , Xiao Jianliang 
Published: June 2020

AbstractA cyclometalated rhodium complex has been found to show excellent activity in dehydrogenation of methanol at room temperature. This feature allows for the catalytic transfer hydrogenation of various aldehydes with methanol as both hydrogen source and solvent under very mild conditions. A hydroxy functionality on the ligand is shown to be critical for this unusual activity.
Dielectric Chiral Metasurfaces for Second‐Harmonic Generation with Strong Circular Dichroism
Authors: Kim Kwang‐Hyon , Kim Ju‐Ryong 
Published: June 2020

AbstractDielectric chiral metasurfaces can generate harmonic waves with high efficiency and strong circular dichroism (CD), when they are supported by metallic substrates. Numerical results show that the second‐harmonic generation (SHG) efficiency of about 10−3% for a peak pump intensity of about 5 GW cm−2 can be achieved in the blue‐UV, and the SHG CD reaches up to about 1.8, from a metasurface of Z‐shaped lithium niobate nanoantenna array supported by gold substrate. Highly efficient and strong circular dichroic nonlinear responses are attributed to the plasmon‐assisted local field enhancement in the dielectric chiral nanoantennae adjacent to the metallic substrate.
Quantendefekte als Werkzeugkasten für die kovalente Funktionalisierung von Kohlenstoffnanoröhren mit Peptiden und Proteinen
Authors: Mann Florian A. , Herrmann Niklas , Opazo Felipe , Kruss Sebastian 
Published: June 2020

AbstractEinwandige Kohlenstoffnanoröhren (SWCNTs) sind ein 1D‐Nanomaterial, das im nahen Infrarot (NIR, >800 nm) fluoresziert. In der Vergangenheit wurde kovalente Chemie zur Funktionalisierung von SWCNTs wenig genutzt, da sie die NIR‐Emission beeinträchtigt. Es sind jedoch bestimmte sp3‐Defekte (Quantendefekte) im Kohlenstoffgitter beobachtet worden, die die NIR‐Fluoreszenz erhalten und sogar zu einer neuen, rotverschobenen Emission führen. Hier berichten wir über Quantendefekte, die mittels lichtinduzierter Diazoniumchemie eingeführt wurden und als Ankerpunkte für Peptide und Proteine dienen. Wir zeigen, dass Maleimid‐Anker die Konjugation Cystein‐haltiger Proteine, z. B. eines GFP‐bindenden Nanobodys, ermöglichen. Darüber hinaus fungiert ein Fmoc‐geschützter Phenylalanin‐Defekt als Ausgangspunkt für die Konjugation von sichtbaren Fluorophoren zur Erzeugung mehrfarbiger SWCNTs und In‐situ‐Peptidsynthese direkt auf dem Nanoröhren. Daher stellen diese Quantendefekte eine vielseitige Plattform dar, um sowohl die photophysikalischen Eigenschaften der Nanoröhren als auch ihre Oberflächenchemie anzupassen.
Crystalline Red Phosphorus Nanoribbons: Large‐Scale Synthesis and Electrochemical Nitrogen Fixation
Authors: Liu Qian , Zhang Xue , Wang Jiahong , Zhang Yanli , Bian Shi , Cheng Ziqiang , Kang Ning , Huang Hao , Gu Shuang , Wang Yun , Liu Danni , Chu Paul K. , Yu Xue‐Feng 
Published: June 2020

AbstractTwo dimensional (2D) nanoribbons constitute an emerging nanoarchitecture for advanced microelectronics and energy conversion due to the stronger size confinement effects compared to traditional nanosheets. Triclinic crystalline red phosphorus (cRP) composed by a layered structure is a promising 2D phosphorus allotrope and the tube‐like substructure is beneficial to the construction of nanoribbons. In this work, few‐layer cRP nanoribbons are synthesized and the effectiveness in the electrochemical nitrogen reduction reaction (NRR) is investigated. An iodine‐assisted chemical vapor transport (CVT) method is developed to synthesize circa 10 g of bulk cRP lumps with a yield of over 99 %. With the aid of probe ultrasonic treatment, high‐quality cRP microcrystals are exfoliated into few‐layer nanoribbons (cRP NRs) with large aspect ratios. As non‐metallic materials, cRP NRs are suitable for the electrochemical nitrogen reduction reaction. The ammonia yield is 15.4 μg h−1 mgcat.−1 at −0.4 V vs. reversible hydrogen electrode in a neutral electrolyte under ambient conditions and the Faradaic efficiency is 9.4 % at −0.2 V. Not only is cRP a promising catalyst, but also the novel strategy expands the application of phosphorus‐based 2D structures beyond that of traditional nanosheets.
Transition‐Metal Catalysis of Triene 6π Electrocyclization: The π‐Complexation Strategy Realized
Authors: Qin Pengjin , Wang Li‐An , O'Connor Joseph M. , Baldridge Kim K. , Li Yifan , Tufekci Burak , Chen Jiyue , Rheingold Arnold L. 
Published: June 2020

AbstractTriene 6π electrocyclization, wherein a conjugated triene undergoes a concerted stereospecific cycloisomerization to a cyclohexadiene, is a reaction of great historical and practical significance. In order to circumvent limitations imposed by the normally harsh reaction conditions, chemists have long sought to develop catalytic variants based upon the activating power of metal–alkene coordination. Herein, we demonstrate the first successful implementation of such a strategy by utilizing [(C5H5)Ru(NCMe)3]PF6 as a precatalyst for the disrotatory 6π electrocyclization of highly substituted trienes that are resistant to thermal cyclization. Mechanistic and computational studies implicate hexahapto transition‐metal coordination as responsible for lowering the energetic barrier to ring closure. This work establishes a foundation for the development of new catalysts for stereoselective electrocyclizations.
Induced Fitting and Polarization of a Bromine Molecule in an Electrophilic Inorganic Molecular Cavity and Its Bromination Reactivity
Authors: Kikukawa Yuji , Seto Kensuke , Watanabe Daiki , Kitajima Hiromasa , Katayama Misaki , Yamashita Shohei , Inada Yasuhiro , Hayashi Yoshihito 
Published: June 2020

AbstractDodecavanadate, [V12O32]4− (V12), possesses a 4.4 Å cavity entrance, and the cavity shows unique electrophilicity. Owing to the high polarizability, Br2 was inserted into V12, inducing the inversion of one of the VO5 square pyramids to form [V12O32(Br2)]4− (V12(Br2)). The inserted Br2 molecule was polarized and showed a peak at 185 cm−1 in the IR spectrum. The reaction of V12(Br2) and toluene yielded bromination of toluene at the ring, showing the electrophilicity of the inserted Br2 molecule. Compound V12(Br2) also reacted with propane, n‐butane, and n‐pentane to give brominated alkanes. Bromination with V12(Br2) showed high selectivity for 3‐bromopentane (64 %) among the monobromopentane products and preferred threo isomer among 2‐,3‐dibromobutane and 2,3‐dibromopenane. The unique inorganic cavity traps Br2 leading the polarization of the diatomic molecule. Owing to its new reaction field, the trapped Br2 shows selective functionalization of alkanes.
Quantum Defects as a Toolbox for the Covalent Functionalization of Carbon Nanotubes with Peptides and Proteins
Authors: Mann Florian A. , Herrmann Niklas , Opazo Felipe , Kruss Sebastian 
Published: June 2020

AbstractSingle‐walled carbon nanotubes (SWCNTs) are a 1D nanomaterial that shows fluorescence in the near‐infrared (NIR, >800 nm). In the past, covalent chemistry was less explored to functionalize SWCNTs as it impairs NIR emission. However, certain sp3defects (quantum defects) in the carbon lattice have emerged that preserve NIR fluorescence and even introduce a new, red‐shifted emission peak. Here, we report on quantum defects, introduced using light‐driven diazonium chemistry, that serve as anchor points for peptides and proteins. We show that maleimide anchors allow conjugation of cysteine‐containing proteins such as a GFP‐binding nanobody. In addition, an Fmoc‐protected phenylalanine defect serves as a starting point for conjugation of visible fluorophores to create multicolor SWCNTs and in situ peptide synthesis directly on the nanotube. Therefore, these quantum defects are a versatile platform to tailor both the nanotube's photophysical properties as well as their surface chemistry.
Unilaterally Fluorinated Acenes: Synthesis and Solid‐State Properties
Authors: Hofmann Philipp E. , Tripp Matthias W. , Bischof Daniel , Grell Yvonne , Schiller Anna L. C. , Breuer Tobias , Ivlev Sergei I. , Witte Gregor , Koert Ulrich 
Published: June 2020

AbstractThe rapid development of organic electronics is closely related to the availability of molecular materials with specific electronic properties. Here, we introduce a novel synthetic route enabling a unilateral functionalization of acenes along their long side, which is demonstrated by the synthesis of 1,2,10,11,12,14‐hexafluoropentacene (1) and the related 1,2,9,10,11‐pentafluorotetracene (2). Quantum chemical DFT calculations in combination with optical and X‐ray absorption spectroscopy data indicate that the single‐molecule properties of 1 are a connecting link between the organic semiconductor model systems pentacene (PEN) and perfluoropentacene (PFP). In contrast, the crystal structure analysis reveals a different packing motif than for the parent molecules. This can be related to distinct F⋅⋅⋅H interactions identified in the corresponding Hirshfeld surface analysis and also affects solid‐state properties such as the exciton binding energy and the sublimation enthalpy.
Dinickelaferrocene: A Ferrocene Analogue with Two Aromatic Nickeloles Realized by Electron Back‐Donation from Iron
Authors: Huang Zhe , Zheng Yu , Zhang Wen‐Xiong , Ye Shengfa , Deng Liang , Xi Zhenfeng 
Published: June 2020

AbstractThe first example of ferrocene analogues with two transition‐metal metallole ligands of the general formula (η5‐C4R4M)2Fe in a sandwich structure are reported. Specifically, dinickelaferrocene 2, a type of dimetallametallocene, is efficiently synthesized from the reaction of dilithionickelole 1 with FeBr2 or FeCl2, presumably via a redox process, and is subjected to detailed experimental (single‐crystal X‐ray structural analysis, ICP‐OES, magnetometry, 57Fe Mössbauer, XPS) and theoretical (MOs, CDA, NICS, ICSS, and AICD) characterizations. Unlike ferrocene and its Cp ligands, the aromaticity of dinickelaferrocene and its nickelole ligands is accomplished by electron back‐donation from the Fe 3d orbitals to the π* orbitals of nickelole. Taken together, this work describes a new class of metallaferrocene sandwich complexes and provides a novel approach to effect aromaticity that will contribute to further development of metallocene chemistry.
The Mechanism of the Magnetodielectric Response in a Molecule‐Based Trinuclear Iron Cluster Material
Authors: Li Dong , Wang Xuan , Zhao Hai‐Xia , Ren Yan‐Ping , Zhuang Gui‐Lin , Long La‐Sheng , Zheng Lan‐Sun 
Published: June 2020

AbstractMagnetodielectric response mechanisms are critical for the rational design and synthesis of molecule‐based magnetodielectric materials. Herein, the magnetodielectric response was investigated in the molecule‐based material [Fe3O(CH3COO)6(py)3](py) (1). Its magnetodielectric coefficient (MD) is −2.8 % for phase transition III and −4.1 % for phase transition I. Study of the mechanism of the magnetodielectric response in 1 reveals that its magnetodielectric response at phase transition I is induced by the charge‐frustration of the trinuclear iron cluster, while that at phase transition III is attributed to the spin‐frustration of the trinuclear iron cluster, providing a new route for the design of magnetodielectric materials.
Feasibility of lime‐modified carbonate soil for highway subgrade filling
Authors: Zheng Yuxin , Li Chunyan , Ma Qingqing 
Published: June 2020

AbstractFor the lime modified carbonate rock soil road subgrade of port highway, after the lime modified carbonate rock filler is used to treat it, the particle discrete unit has the characteristics of sparsity, and the particle gradation is caused by the seepage of soil mass, and with the increase in load, overload load occurs. It is therefore necessary to establish relevant mathematical models to analyze the load variation of lime‐modified carbonate roadbed under boundary conditions. The probability mathematical model of the load overload of lime‐modified carbonate fill was studied, and a feasibility analysis model of lime‐modified carbonate soil used in port city highway subgrade filling was put forward based on the discrete hysteretic characteristic curve method. The load characteristics of lime‐modified carbonate soil were analyzed within the limited area distribution range of adjacent two holes. The load energy transfer model of lime‐modified carbonate packing in foundation soil was analyzed in PFC3D software. The foundation stress reinforcement method was used to improve the carbonate soil foundation construction and, combined with the seepage model of the radial consolidation of the foundation, a filling feasibility analysis of the urban highway subgrade of lime‐modified carbonate soil port was carried out. The simulation results show that this method can effectively realize the load overload analysis of lime‐modified carbonate packing, improve the load capacity of subgrade filler for port city highway, and improve the load property of highway subgrade of port city. Keep the soil particles in close contact. This study provides a feasible basis for future highway construction and the application of lime‐modified carbonate.
A correlation between morphology and mechanical performance of injected‐molded PE/EVA/clay nanocomposites: Insight into phase miscibility and interfacial phenomena
Authors: Hosseiny Seyed Majid , Jafari Seyed Hassan , Khonakdar Hossein Ali , Hemmati Farkhondeh , Kalaee Mohammad Reza 
Published: June 2020

AbstractIn this study, the correlations between the mechanical performance and structural properties of injected‐molded polyethylene (PE)/ethylene‐vinyl acetate copolymer (EVA)/nanoclay (NC) nanocomposites are investigated by revisiting the interfacial phenomena and miscibility state of the component pairs. The effects of different parameters including the injection molding temperature, mixing sequence in melt‐compounding process, blend composition, and nanoclay loading are studied. A great complexity arises in the filling and cooling process of the injected‐molded parts owing to the phase behavior of the polyolefin blend, crystallization, and morphological changes. The injection molding temperature positively influences the elastic modulus, tensile strength and impact strength of PE/EVA/NC systems through the improvements in the PE/EVA partial miscibility, mutual solubility, and interfacial interactions of PE/clay and PE/EVA pairs. By applying a two‐step mixing process before the injection molding, more nanoclay stacks with smaller thicknesses and larger clay interlayer spacing are formed. The stronger pinning effect of nanoparticles in the second mixing sequence retards the phase separation phenomenon of PE/EVA blend during the cooling stage. As a result of improved mutual PE/EVA solubility, the elastic modulus and tensile strength decrease and the impact resistance increases in the PE‐rich systems. On the other hand, an opposite trend for these properties is found for the EVA‐rich systems.
Synthesis, characterization, and cytotoxicity of PCL–PEG–PCL diacrylate and agarose interpenetrating network hydrogels for cartilage tissue engineering
Authors: Su Zih‐Cheng , Lin Shih‐Jie , Chang Yu‐Hsuan , Yeh Wen‐Ling , Chu I‐Ming 
Published: June 2020

AbstractHydrogels are suitable biomaterials for cartilage tissue engineering due to the excellent ability to retain water to provide suitable environment for the tissue, however, the insufficient mechanical properties often prevent their wider applications. The objective of this study was to fabricate biocompatible hydrogels with good mechanical performance, high‐water content, and porous microstructure for cartilage regeneration. Photocrosslinked hydrogels are one of the most widely used systems in tissue engineering due to the superior mechanical properties. In this study, block copolymer, poly(ε ‐caprolactone)‐poly(ethylene)‐poly(ε‐caprolactone) diacrylate (PCL–PEG–PCL; PEC), was prepared by ring‐opening polymerization, and PEC hydrogels were made through free radical crosslinking mechanism. Agarose network is chosen as another component of the hydrogels, because of the high‐swelling behavior and cartilage‐like microstructure, which is helpful for chondrocytes growth. Interpenetrating networks (IPN) were fabricated by diffusing PEC into agarose network followed by photo‐crosslinking process. It was noted that incorporating PEC into the agarose network increased the elastic modulus and the compressive failure properties of individual component networks. In addition, high‐swelling ratio and uniform porosity microstructures were found in the IPN hydrogels. IPN and PEC showed low cytotoxicity and good biocompatibility in elution test method. The results suggest promising characteristics of IPN hydrogels as a potential biomaterial for cartilage tissue engineering.
SPEEK‐Tin dioxide proton conducting membranes: Effect of modifying agent of tin dioxide particles surface
Authors: de Aguiar Liz Contino Vianna , de Ramos Filho Florêncio Gomes , Dahmouche Karim , Perez Gerônimo , Archanjo Braulio Soares , Kawaguti Carla Akimi , de Souza Gomes Ailton 
Published: June 2020

AbstractProton‐conducting membranes based on sulphonated poly (ether ether ketone) (SPEEK) polymer matrix and tin dioxide have been synthesized. Their local structure has been studied by FTIR and XRD whereas their structural features at nanometer scale has been investigated by Small‐Angle X‐ray Scattering (SAXS) and transmission electron microscopy (TEM). SAXS and TEM results show that incorporation of the inorganic particles in SPEEK promotes dispersion of the hydrophilic sulfonic groups in the polymer matrix, inhibiting the formation of the water‐filled ionic clusters usually observed in hydrated SPEEK membranes. The changes in SPEEK nanostructure are induced by incorporation of particles modified by Tiron that promotes the connectivity between hydrated channels and reduces diffusion of alcohol, as evidenced by permeability measurements. The resulting increase of proton conductivity compared to pristine SPEEK, particularly at medium temperature (80°C), combined to an improved dimensional stability, make this family of membranes very promising for future applications in fuel cell.
Synthesis of hydrogels with a gradient crosslinking structure by electron beam radiation to an aqueous solution of poly(sodium acrylate)
Authors: Dohi Shunsuke , Matsumoto Akikazu 
Published: June 2020

AbstractHydrogels were prepared by electron beam (EB) radiation to the aqueous solutions of poly(sodium acrylate) in the presence of potassium and ammonium peroxodisulfates. The effects of EB radiation dose, as well as polymer, and initiator concentrations on the formation of gels, were investigated. On the basis of the storage modulus, loss modulus, and complex viscosity of the isolated gels determined by rheological measurement, the relationship between the radiation conditions and the rheological properties of the gels was discussed. Furthermore, hydrogels with a gradient crosslinking structure in a depth direction were synthesized by controlling EB radiation dose.