bluuebunny/crossref_metadata_2025_split huggingface dataset:
Direct Growth of Edge‐Rich Graphene with Tunable Dielectric Properties in Porous Si3N4 Ceramic for Broadband High‐Performance Microwave Absorption
Authors: Ye Fang , Song Qiang , Zhang Zhenchuang , Li Wei , Zhang Shouyang , Yin Xiaowei , Zhou Yuzhao , Tao Huiwen , Liu Yongsheng , Cheng Laifei , Zhang Litong , Li Hejun 
Published: February 2018

AbstractHigh‐performance graphene microwave absorption materials are highly desirable in daily life and some extreme situations. A simple technique for the direct growth of graphene as absorption fillers in wave‐transmitting matrices is of paramount importance to bring it to real‐world application. Herein, a simple chemical vapor deposition (CVD) route for the direct growth of edge‐rich graphene (ERG) with tailored structures and tunable dielectric properties in porous Si3N4 ceramics using only methyl alcohol (CH3OH) as precursor is reported. The large O/C atomic ratio of CH3OH helps to build a mild oxidizing atmosphere and leads to a unique structure featuring open graphite nanosteps and freestanding nanoplanes, endowing the ERG/Si3N4 hybrid with an appropriate balance between good impedance matching and strong loss capacity. Accordingly, the prepared materials exhibit superior electromagnetic wave absorption, far surpassing that of traditional CVD graphene and reduced graphene oxide‐based materials, achieving an effective absorption bandwidth of 4.2 GHz covering the entire X band, with a thickness of 3.75 mm and a negligibly low loading content of absorbents. The results provide new insights for developing novel microwave absorption materials with strong reflection loss and wide absorption frequency range.
Quantum Emitters in Hexagonal Boron Nitride Have Spectrally Tunable Quantum Efficiency
Authors: Schell Andreas W. , Svedendahl Mikael , Quidant Romain 
Published: February 2018

AbstractUnderstanding the properties of novel solid‐state quantum emitters is pivotal for a variety of applications in research fields ranging from quantum optics to biology. Recently discovered defects in hexagonal boron nitride are especially interesting, as they offer much desired characteristics such as narrow emission lines and photostability. Here, the dependence of the emission on the excitation wavelength is studied. It is found that, in order to achieve bright single‐photon emission with high quantum efficiency, the excitation wavelength has to be matched to the emitter. This is a strong indication that the emitters possess a complex level scheme and cannot be described by a simple two or three‐level system. Using this excitation dependence of the emission, further insight to the internal level scheme is gained and it is demonstrated how to distinguish different emitters both spatially as well as in terms of their photon correlations.
Engineering Extracellular Vesicles with the Tools of Enzyme Prodrug Therapy
Authors: Fuhrmann Gregor , Chandrawati Rona , Parmar Paresh A. , Keane Timothy J. , Maynard Stephanie A. , Bertazzo Sergio , Stevens Molly M. 
Published: February 2018

AbstractExtracellular vesicles (EVs) have recently gained significant attention as important mediators of intercellular communication, potential drug carriers, and disease biomarkers. These natural cell‐derived nanoparticles are postulated to be biocompatible, stable under physiological conditions, and to show reduced immunogenicity as compared to other synthetic nanoparticles. Although initial clinical trials are ongoing, the use of EVs for therapeutic applications may be limited due to undesired off‐target activity and potential “dilution effects” upon systemic administration which may affect their ability to reach their target tissues. To fully exploit their therapeutic potential, EVs are embedded into implantable biomaterials designed to achieve local delivery of therapeutics taking advantage of enzyme prodrug therapy (EPT). In this first application of EVs for an EPT approach, EVs are used as smart carriers for stabilizing enzymes in a hydrogel for local controlled conversion of benign prodrugs to active antiinflammatory compounds. It is shown that the natural EVs' antiinflammatory potential is comparable or superior to synthetic carriers, in particular upon repeated long‐term incubations and in different macrophage models of inflammation. Moreover, density‐dependent color scanning electron microscopy imaging of EVs in a hydrogel is presented herein, an impactful tool for further understanding EVs in biological settings.
The long‐tail of online grocery shopping
Authors: Richards Timothy J. , Rabinovich Elliot 
Published: February 2018

AbstractThe “retail long tail” effect implies that both the level and concentration of sales moves to slower selling products in online environments, and total sales rise. We analyze the effect of assortment variation on store sales using data from an online food seller in the Eastern United States. We find that the long‐tail effect is more important in niche categories, deeper assortments are associated with a flatter distribution of sales, and total sales rise with variety. Our findings support the existence of a long tail in online food retailing. [EconLit citations: L16, L81, M31]
Design, Synthesis, and Application of Chiral C2‐Symmetric Spiroketal‐Containing Ligands in Transition‐Metal Catalysis
Authors: Argüelles Alonso J. , Sun Siyuan , Budaitis Brenna G. , Nagorny Pavel 
Published: February 2018

AbstractWe present an expedient and economical route to a new spiroketal‐based C2‐symmetric chiral scaffold, termed SPIROL. Based on this spirocyclic scaffold, several chiral ligands were generated. These ligands were successfully employed in an array of stereoselective transformations, including in iridium‐catalyzed hydroarylations (up to 95 % ee), palladium‐catalyzed allylic alkylations (up to 97 % ee), intermolecular palladium‐catalyzed Heck couplings (up to 94 % ee), and rhodium‐catalyzed dehydroalanine hydrogenation (up to 93 % ee).
Spectroscopic and Computational Characterization of Diethylenetriaminepentaacetic Acid/Transplutonium Chelates: Evidencing Heterogeneity in the Heavy Actinide(III) Series
Authors: Deblonde Gauthier J.‐P. , Kelley Morgan P. , Su Jing , Batista Enrique R. , Yang Ping , Booth Corwin H. , Abergel Rebecca J. 
Published: February 2018

AbstractThe chemistry of trivalent transplutonium ions (Am3+, Cm3+, Bk3+, Cf3+, Es3+…) is usually perceived as monotonic and paralleling that of the trivalent lanthanide series. Herein, we present the first extended X‐ray absorption fine structure (EXAFS) study performed on a series of aqueous heavy actinide chelates, extending past Cm. The results obtained on diethylenetriaminepentaacetic acid (DTPA) complexes of trivalent Am, Cm, Bk, and Cf show a break to much shorter metal–oxygen nearest‐neighbor bond lengths in the case of Cf3+. Corroborating those results, density functional theory calculations, extended to Es3+, suggest that the shorter Cf−O and Es−O bonds could arise from the departure of the coordinated water molecule and contraction of the ligand around the metal relative to the other [MIIIDTPA(H2O)]2− (M=Am, Cm, Bk) complexes. Taken together, these experimental and theoretical results demonstrate inhomogeneity within the trivalent transplutonium series that has been insinuated and debated in recent years, and that may also be leveraged for future nuclear waste reprocessing technologies.
Dual C(sp3)−H Bond Functionalization of N‐Heterocycles through Sequential Visible‐Light Photocatalyzed Dehydrogenation/[2+2] Cycloaddition Reactions
Authors: Xu Guo‐Qiang , Xu Ji‐Tao , Feng Zhi‐Tao , Liang Hui , Wang Zhu‐Yin , Qin Yong , Xu Peng‐Fei 
Published: February 2018

AbstractHerein we describe a mild method for the dual C(sp3)−H bond functionalization of saturated nitrogen‐containing heterocycles through a sequential visible‐light photocatalyzed dehydrogenation/[2+2] cycloaddition procedure. As a complementary approach to the well‐established use of iminium ion and α‐amino radical intermediates, the elusive cyclic enamine intermediates were effectively generated by photoredox catalysis under mild conditions and efficiently captured by acetylene esters to form a wide array of bicyclic amino acid derivatives, thus enabling the simultaneous functionalization of two vicinal C(sp3)−H bonds.
Rapid Analysis of Cell–Nanoparticle Interactions using Single‐Cell Raman Trapping Microscopy
Authors: Steinke Maria , Zunhammer Florian , Chatzopoulou Elisavet I. , Teller Henrik , Schütze Karin , Walles Heike , Rädler Joachim O. , Grüttner Cordula 
Published: February 2018

AbstractIron oxide nanoparticles have been used in preclinical studies to label stem cells for non‐invasive tracking and homing. The search continues for novel particle candidates that are suitable for clinical applications. Since standard analyses to investigate cell–particle interactions and safety are labor‐intensive, an efficient procedure is required to guide future particle development and to exclude adverse health effects. The application of combined Raman trapping microscopy with fluidic chips is reported for the analysis of single cells labeled with different types of aminated iron oxide particles. Multivariate data analysis revealed Raman signal differences that could be clearly assigned to cell–particle interactions and cytotoxicity, respectively. A validation dataset verified that more than 95 % of the spectra were correctly classified. Thus, our approach enables rapid discrimination of non‐hazardous from cytotoxic nanoparticles as a prerequisite for safe clinical applications.
Metal‐Free Dehydrogenation of N‐Heterocycles by Ternary h‐BCN Nanosheets with Visible Light
Authors: Zheng Meifang , Shi Jiale , Yuan Tao , Wang Xinchen 
Published: February 2018

AbstractAn efficient metal‐free catalytic system has been developed based on hexagonal boron carbon nitride (h‐BCN) nanosheets for the dehydrogenation of N‐heterocycles with visible light; hydrogen gas is released in the process, and thus no proton acceptor is needed. This acceptorless dehydrogenation of hydroquinolines, hydroisoquinolines, and indolines to the corresponding aromatic N‐heterocycles occurred in excellent yield under visible‐light irradiation at ambient temperature. With h‐BCN as the photocatalyst and water as the solvent, this environmentally benign protocol shows broad substitution tolerance and high efficiency.
Chaotropic Monovalent Anion‐Induced Rectification Inversion at Nanopipettes Modified by Polyimidazolium Brushes
Authors: He Xiulan , Zhang Kailin , Liu Yang , Wu Fei , Yu Ping , Mao Lanqun 
Published: February 2018

AbstractA nonintuitive observation of monovalent anion‐induced ion current rectification inversion at polyimidazolium brush (PimB)‐modified nanopipettes is presented. The rectification inversion degree is strongly dependent on the concentration and species of monovalent anions. For chaotropic anions (for example, ClO4−), the rectification inversion is easily observed at a low concentration (5 mm), while there is no rectification inversion observed for kosmotropic anions (Cl−) even at a high concentration (1 m). Moreover, at the specific concentration (for example, 10 mm), the variation of rectification ratio on the type of anions is ranged by Hofmeister series (Cl−≥NO3−>BF4−>ClO4−>PF6−>Tf2N−). Estimation of the electrokinetic charge density (σek) demonstrates that rectification inversion originates from the charge inversion owing to the over‐adsorption of chaotropic monovalent anion. To qualitatively understand this phenomenon, a concentration‐dependent adsorption mechanism is proposed.
Fluoride‐Catalyzed Deblocking: A Route to Polymeric Urethanes
Authors: Sheri Madhu , Choudhary Umesh , Grandhee Sunitha , Emrick Todd 
Published: February 2018

AbstractWe report a fluoride‐catalyzed deblocking of urethanes as “blocked” isocyanates. Organic and inorganic sources of fluoride ion proved effective for deblocking urethanes and for converting polyurethanes to small molecules. Distinct from conventional deblocking chemistry involving organometallic compounds and high temperatures, the method we describe is metal‐free and operates at or slightly above room temperature. The use of fluorescent blocking agents enabled visual and spectroscopic monitoring of blocking/deblocking reactions, and the selected conditions proved applicable to urethanes containing a variety of blocking groups. The method additionally enabled a one pot deblocking and polymerization with α,ω‐diols. Overall, this deblocking/polymerization strategy offers a convenient and efficient solution to problems that have limited the breadth of applications of polyurethane chemistry.
Pathway Complexity Versus Hierarchical Self‐Assembly in N‐Annulated Perylenes: Structural Effects in Seeded Supramolecular Polymerization
Authors: Greciano Elisa E. , Matarranz Beatriz , Sánchez Luis 
Published: February 2018

AbstractStudies were carried out on the hierarchical self‐assembly versus pathway complexity of N‐annulated perylenes 1–3, which differ only in the nature of the linking groups connecting the perylene core and the side alkoxy chains. Despite the structural similarity, compounds 1 and 2 exhibit noticeable differences in their self‐assembly. Whereas 1 forms an off‐pathway aggregate I that converts over time (or by addition of seeds) into the thermodynamic, on‐pathway product, 2 undergoes a hierarchical process in which the kinetically trapped monomer species does not lead to a kinetically controlled supramolecular growth. Finally, compound 3, which lacks the amide groups, is unable to self‐assemble under identical experimental conditions and highlights the key relevance of the amide groups and their position to govern the self‐assembly pathways.
Preparation of sound‐insulating material based on discarded cow hair
Authors: Zhang Yiwei , Zhang Benmin , Shan Zhihua 
Published: February 2018

ABSTRACTIn this article, we report a study on new functional materials based on the structural features of hair. In this study, discarded cow hair was treated with acid and hydrogen peroxide, dried, and pulverized to obtain a hair powder (HP). A sound‐insulating film (SIF) was prepared via the mixing of HP with acrylic resin [poly(acrylic acid) (PAA)]. On the basis of the function for the SIF, the formation conditions, including the HP weight percentage, film‐forming temperature, and solvent, were investigated. The sound‐insulating properties were studied and compared with commercially available sound‐insulating materials. The SIF had an equivalent sound‐insulating power to that of an asphalt‐based or a rubber‐based board but a better power than that of a polyurethane (PU)‐foam‐based board with identical thicknesses in the 20–20,000 Hz sound wave. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46332.
Rheological characterization and modeling of vulcanization kinetics of natural rubber/starch blends
Authors: Alwaan Ismaeel Moslam 
Published: February 2018

ABSTRACTVulcanization kinetics of natural rubber/starch (NR/ST) blends was investigated by oscillating disc rheometer. The scorch and cure times are significantly reduced with the loading of starch in all blends from 1.15 and 2.22 to 0.91 and 1.88 min, respectively, to improve curing rate. Meanwhile, the maximum torque values and the maximum vulcanization rate of NR/ST blend increase with the starch loading from 1.51 N m and 0.387 min−1 to 2.224 N m and 0.492 min−1 respectively. The results of vulcanization kinetics of NR and its blends revealed that it is controlled by two‐stages, chemical and diffusion. The experimental data of the vulcanization rate of NR/ST blends did not fit with autocatalytic kinetic model except the pure natural rubber. Therefore, the Criado method was used and it was observed that the reaction kinetic model of pure NR and its blends with starch is best described by the D diffusion model (D2). © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46347.
Stabilization of the Pentazolate Anion in Three Anhydrous and Metal‐Free Energetic Salts
Authors: Xu Yuangang , Lin Qiuhan , Wang Pengcheng , Lu Ming 
Published: February 2018

AbstractAccording to previous reports, metal cations or water molecules are necessary for the stabilization of pentazolate anion (cyclo‐N5−) at ambient temperature and pressure. Seeking a new method to stabilize N5− is a big challenge. In this work, three anhydrous, metal‐free energetic salts based on cyclo‐N5− 3,9‐diamino‐6,7‐dihydro‐5 H‐bis([1,2,4]triazolo)[4,3‐e:3′,4′‐g][1,2,4,5] tetrazepine‐2,10‐diium, N‐carbamoylguanidinium, and oxalohydrazinium (oxahy+) pentazolate were synthesized and isolated. All salts were characterized by elemental analysis, IR spectroscopy, 1H, 13C, and (in some cases) 15N NMR spectroscopy, thermal analysis (TGA and DSC), and single‐crystal XRD analysis. Computational studies associated with heats of formation and detonation performance were performed by using Gaussian 09 and Explo5 programs, respectively. The sensitivity of the salts towards impact and friction was determined, and overall the real N5 explosives showed promising energetic properties.
Sugar yield and composition of tubers from Jerusalem Artichoke (Helianthus tuberosus) irrigated with saline waters
Authors: Bhagia Samarthya , Ferreira Jorge F. S. , Kothari Ninad , Nunez Angelica , Liu Xuan , da Silva Dias Nildo , Suarez Donald L. , Kumar Rajeev , Wyman Charles E. 
Published: February 2018

AbstractCurrently, major biofuel crops are also food crops that demand fertile soils and good‐quality water. Jerusalem artichoke (Helianthus tuberosus, Asteraceae) produces high tonnage of tubers that are rich in sugars, mainly in the form of inulin. In this study, plants of the cultivar “White Fuseau” grown under five salinity levels were evaluated for tuber yield. Results indicated that this cultivar is moderately salt‐tolerant if the goal is tuber production. Hydraulic pressings of the tubers produced juice that contained 15% (wet weight) or 55% (dry weight) free sugars, with 70% of these in the form of inulin and the rest as fructose, sucrose, and glucose. Importantly, salinity did not affect the total free sugar or inulin content of the tubers. Tubers were composed of about 12% dry washed bagasse (wet weight) or 44% (dry matter basis) and bagasse retained such high quantities of free sugars after pressing that washing was required for complete sugar recovery. Chemical composition analysis of tuber bagasse suggested that it had low lignin content (11–13 wt%), and its structural sugar composition was similar to chicory root bagasse. Because of the high hemicellulose and pectin content of the bagasse, adding xylanase and pectinase to cellulase substantially improved sugar yields from enzymatic hydrolysis compared to at the same protein loading as cellulase alone. In addition to the high total sugar yield of tuber, these first findings on the sugar and lignin content and enzymatic hydrolysis of tuber bagasse can lead to low‐cost production of ethanol for transportation fuels.
Quantitative determination of risperidone, paliperidone and olanzapine in human serum by liquid chromatography–tandem mass spectrometry coupled with on‐line solid‐phase extraction
Authors: Ruan Can‐Jun , Guo Wei , Zhou Miao , Guo Gui‐Xin , Wang Chuan‐Yue , Li Wen‐Biao , de Leon Jose 
Published: February 2018

AbstractA recent guideline recommends therapeutic drug monitoring for risperidone, paliperidone and olanzapine, which are frequently used second‐generation antipsychotics. We developed a simple high‐performance liquid chromatography–tandem mass spectrometry coupled with an online solid‐phase extraction method that can be used to measure risperidone, paliperidone and olanzapine using small (40 μL) samples. The analytes were extracted from serum samples automatically pre‐concentrated and purified by C8 (5 μm, 2.1 × 30 mm) solid‐phase extraction cartridges, then chromatographed on an Xbidge™ C18 column (3.5 μm, 100 × 2.1 mm) thermostatted at 30°C with a mobile phase consisting of 70% acetonitrile and 30% ammonium hydroxide 1% solution at an isocratic flow rate of 0.3 mL/min, and detected with tandem mass spectrometry. The assay was validated in the concentration range from 2.5 to 160 ng/mL. Intra‐ and inter‐day precision for all analytes was between 1.1 and 8.2%; method accuracy was between 6.6 and 7.6%. The risperidone and paliperidone assay was compared with a high‐performance liquid chromatography‐ultraviolet assay currently used in our hospital for risperidone and paliperidone therapeutic drug monitoring, and the results of weighted Deming regression analysis showed good agreement. For the olanzapine assay, we compared 20 samples in separate re‐assays on different days; all the relative errors were within the 20% recommended limit.
Secondary stakeholder pressures and organizational adoption of sustainable operations practices: The mediating role of primary stakeholders
Authors: Shubham  , Charan Parikshit , Murty L.S. 
Published: February 2018

AbstractOrganizations face increasing pressure from stakeholder groups to adopt sustainable practices and improve their environmental performance. Contemporary frameworks on corporate environmental responsibility observe that stakeholders positively influence organizational response in the form of adoption of sustainable operations practices. However, these frameworks provide little evidence on the distinction between the influences of different stakeholder groups on shaping organizations’ environmental responses. This paper proposes and empirically tests how different stakeholder groups, directly and indirectly, influence organizational adoption of sustainable operations practices. Based on a sample from an emerging economy, we show that the primary stakeholders, because of the reciprocal and direct transactional relationship with the firm, directly influence an organization's environmental policies. By contrast, secondary stakeholders try to influence organizations indirectly via primary stakeholders. The results indicate that there is a distinction between different stakeholder groups, and secondary stakeholders can exercise their influence over organizational environmental decisions via primary stakeholders.
Nonprecious‐metal Fe/N/C Catalysts Prepared from π‐Expanded Fe Salen Precursors toward an Efficient Oxygen Reduction Reaction
Authors: Tanaka Yuta , Onoda Akira , Okuoka Shin‐ichi , Kitano Tomoyuki , Matsumoto Koki , Sakata Takao , Yasuda Hidehiro , Hayashi Takashi 
Published: February 2018

AbstractThe front cover artwork for issue 4/2018 represents research conducted in a collaboration between Osaka University (Japan) and Nippon Shokubai Co., Ltd. (Japan). The image illustrates the preparation of the Fe/N/C catalysts by pyrolysis of π‐expanded Fe(Salen) precursors for the oxygen reduction reaction. See the Full Paper itself at https://doi.org/10.1002/cctc.201701629.
Spacer Length‐Independent Shuttling of the Pillar[5]arene Ring in Neutral [2]Rotaxanes
Authors: Ogoshi Tomoki , Kotera Daisuke , Nishida Shungo , Kakuta Takahiro , Yamagishi Tada‐aki , Brouwer Albert M. 
Published: February 2018

AbstractFor a series of neutral [2]rotaxanes consisting of a pillar[5]arene ring and axles possessing two stations separated by flexible spacers of different lengths, the free energies of activation for the ring shuttling between the stations were found to be independent of the spacer length. The constitution of the spacer affects the activation energies: replacement of CH2 groups by repulsive oxygen atoms in the axle increases the barrier. The explanation for the observed length‐independence lies in the presence of a barrier for re‐forming the stable co‐conformation, which makes the ring travel back and forth along the thread in an intermediate state.