bluuebunny/crossref_metadata_2025_split huggingface dataset:
Screening and identification of hepatotoxic component in Evodia rutaecarpa based on spectrum–effect relationship and UPLC‐Q‐TOFMS
Authors: Li Wenlan , Sun Xiangming , Liu Bingmei , Zhang Lihui , Fan Ziquan , Ji Yubin 
Published: May 2016

AbstractEvodia rutaecarpa (E. rutaecarpa) has been used to treat aches, vomiting and dysentery in traditional Chinese medicine. However, as a mildly toxic herb its toxic components have not been elucidated. An attempt was made to illuminate the hepatotoxic constituents of E. rutaecarpa. The 50% ethanol extracts of E. rutaecarpa from 19 different sources were used to establish UPLC fingerprints and administered to mice at a dose of 35 g/kg (crude medicine weight/mouse weight) once daily for 14 days. Serum levels of alanine transaminase, aspartate aminotransferase and liver coefficient were used as indices of liver injury. Additionally, the characteristic peaks of 19 fingerprints were identified. Spectrum–effect relationships between fingerprints and hepatotoxic indicators were analyzed using bivariate correlation analysis (BCA). The UPLC fingerprints were established and a total of 28 main compounds were identified. Because of the inherent variations in chemical compositions, the liver injury levels were different among the E. rutaecarpa samples from 19 sites of production. BCA results indicated that compounds dihydrorutaecarpine, 6‐acetoxy‐5‐epilimonin, goshuyuamide I, 1‐methyl‐2‐[(Z)‐5‐undecenyl]‐4(1H)‐quinolone, 1‐methyl‐2‐[(4Z,7Z)‐4,7‐tridecadienyl]‐4(1H)‐quinolone, evocarpine and 1‐methyl‐2‐[(6Z,9Z)‐6,9‐pentadecadienyl]‐4(1H)‐quinolone were tentatively determined as the primary hepatotoxic components. The present study provides a valuable method for the discovery of hepatotoxic constituents by combination of fingerprints and hepatotoxicity index.
Carbon Flux Trapping: Highly Efficient Production of Polymer‐Grade d‐Lactic Acid with a Thermophilic d‐Lactate Dehydrogenase
Authors: Li Chao , Tao Fei , Xu Ping 
Published: May 2016

AbstractHigh production of polymer‐grade d‐lactic acid is urgently required, particularly for the synthesis of polylactic acid. High‐temperature fermentation has multiple advantages, such as lower equipment requirement and energy consumption, which are essential for lowering operating costs. We identified and introduced a unique d‐lactate dehydrogenase into a thermotolerant butane‐2,3‐diol‐producing strain. Carbon flux “trapping” was achieved by a “trapping point” created by combination of the introduced enzyme and the host efflux pump, which afforded irreversible transport of d‐lactic acid. The overall carbon flux of the engineered strain was significantly enhanced and was redistributed predominantly to d‐lactic acid. Under optimized conditions at 50 °C, d‐lactic acid reached the highest titer (226.6 g L−1) reported to date. This discovery allows us to extend the carbon flux trapping strategy to engineering complex metabolic networks.
Photocatalytic Activity of Zirconium‐ and Manganese‐Codoped Titania in Aqueous Media: The Role of the Metal Dopant and its Incorporation Site
Authors: Pliekhov Oleksii , Arčon Iztok , Tušar Nataša Novak , Štangar Urška Lavrenčič 
Published: May 2016

AbstractThe development of efficient TiO2‐based photocatalysts for water treatment is mainly performed by doping with transition metals or by establishing junctions between different phases, metal–semiconductor or semiconductor–semiconductor. We present, for the first time, the synthesis of Zr‐ and Mn‐modified TiO2 by a redesigned sol–gel technique that allows the formation of heterometallic bridges on the TiO2 surface. Cations of the doping metals are located in the pores of mesoporous anatase and attached to the crystalline TiO2 walls. The presence of the Zr enhances the photoactivity of the TiO2 catalyst. However, the introduction of Mn decreases the photocatalytic efficiency in a nonadditive manner. The inhibition effect was assigned to the side reaction between hydroxyl radicals and Mn ions. The fact that Mn effectively scavenges the hydroxyl radicals and, consequently, inhibits the whole oxidation process is direct proof that hydroxyl radicals are the main reactive species in the photocatalytic oxidative processes on TiO2 surfaces in aqueous media and the process of .OH generation is the rate‐determining step, which was confirmed using a method based on the decolorization of a commercial dye Bezaktiv Blau in a reaction with Fenton's reagent as a source of hydroxyl radicals.
The Influence of Hemicellulose Sugars on Product Distribution of Early‐Stage Conversion of Lignin Oligomers Catalysed by Raney Nickel
Authors: Chesi Claudio , de Castro Ilton B. D. , Clough Matthew T. , Ferrini Paola , Rinaldi Roberto 
Published: May 2016

AbstractWe recently introduced catalytic upstream biorefining, a fractionation process performed on whole lignocellulosic materials, based on the early‐stage conversion of lignin by hydrogen‐transfer reactions (using Raney Ni as the catalyst and 2‐PrOH as a hydrogen‐donor). The process fractionates lignocellulose, isolating lignin as an extensively depolymerised oil, opening up new avenues in the catalytic upgrading of bio‐derived phenolic streams to chemicals and fuels. In addition, highly delignified holocellulose pulps are obtained, holding potential as a feedstock for the production of paper, chemicals, and biofuels. Herein, we report our first results on the chemistry underlying this process under nearly neutral to slightly alkaline conditions achieved by the addition of inorganic bases. This report sheds light on the influence of hemicellulose sugars on the product distribution obtained from the early‐stage catalytic conversion of lignin oligomers released from lignocellulose. The increase in the pH value of the medium suppressed the hydrolysis of xylans. As a result, a dramatic increase in the xylans retention from 10 % (at pH 4.5) up to 60 % (at pH>7.5) was achieved. Interestingly, the pH value of the liquor did not affect the delignification extent of lignocellulose or the absolute content of glucans retained in the holocellulose. By enhancing xylans retention, we provide evidence that hemicellulose sugars decrease the activity of Raney Ni towards full hydrogenation of the aromatic species composing the lignin stream. In fact, the yield of selected cyclohexanols increases from 0.8 % (no added bases) to 4.4 % (added NaOH), whereas the yield of selected phenols decreases from 12.9 % (no added bases) to 7.2 % (added NaOH).
Study of Lanthanum Manganate and Yttrium‐Stabilized Zirconia‐Supported Palladium Dual‐Bed Catalyst System for the Total Oxidation of Methane: A Study by 18O2/16O2 Isotopic Exchange
Authors: Richard Mélissandre , Can Fabien , Gil Sonia , Giroir‐Fendler Anne , Duprez Daniel , Bion Nicolas 
Published: May 2016

AbstractThe front cover artwork for Issue 11/2016 is provided by researchers from IC2MP (University of Poitiers, CNRS) and IRCELYON (University of Lyon 1, CNRS). The image shows the enhancement of the methane oxidation activity on yttrium‐stabilized zirconia‐supported palladium implied by the exchange process occurring between gaseous oxygen and lattice oxygen atoms from lanthanum manganate. See the Full Paper itself at http://dx.doi.org/10.1002/cctc.201501398.
Per‐Substituted [8]Circulene and Its Non‐Planar Fragments: Synthesis, Structural Analysis, and Properties
Authors: Feng Chieh‐Ning , Hsu Wen‐Ching , Li Jen‐Yi , Kuo Ming‐Yu , Wu Yao‐Ting 
Published: May 2016

AbstractThe syntheses, structures, and physical properties of a full series of benzannulated tetraphenylenes are reported. The palladium‐catalyzed annulation of tetraiodo‐substituted 2,3,6,7,10,11,14,15‐octamethyltetraphenylene with insufficient di(4‐anisyl)ethyne yielded a mixture of per‐substituted [8]circulene and its non‐planar fragments, including mono‐, para‐di‐, ortho‐di‐, and triannulated products. Their structures were unambiguously verified by X‐ray crystallography. Successive benzannulations significantly affect the molecular geometries, dynamic behaviors, and physical properties of the compounds. In this series of compounds, [8]circulene is the most strained one, as reflected by the significant deplanarization of the phenanthrene moieties (ca. 63° in the bay region) and the fact that it has the highest strain energy (120.6 kcal mol−1). The dynamic behaviors of these compounds were examined both experimentally and theoretically. The ring flipping of per‐substituted [8]circulene is confirmed to proceed through pseudorotation with a barrier of around 21 kcal mol−1, whereas its non‐planar fragments require much more energy for the ring inversion. The photophysical and electrochemical properties of the investigated compounds depend strongly on the extent of efficient π conjugation. The successive benzannulations red‐shift both the absorption and the emission bands, and reduce the first oxidation potential.
Helicenes as All‐in‐One Organic Materials for Application in OLEDs: Synthesis and Diverse Applications of Carbo‐ and Aza[5]helical Diamines
Authors: Jhulki Samik , Mishra Abhaya Kumar , Chow Tahsin J. , Moorthy Jarugu Narasimha 
Published: May 2016

AbstractA set of eight helical diamines were designed and synthesized to demonstrate their relevance as all‐in‐one materials for multifarious applications in organic light‐emitting diodes (OLEDs), that is, as hole‐transporting materials (HTMs), EMs, bifunctional hole transporting + emissive materials, and host materials. Azahelical diamines function very well as HTMs. Indeed, with high Tg values (127–214 °C), they are superior alternatives to popular N,N′‐di(1‐naphthyl)‐N,N′‐diphenyl‐(1,1′‐biphenyl)‐4,4′‐diamine (NPB). All the helical diamines exhibit emissive properties when employed in nondoped as well as doped devices, the performance characteristics being superior in the latter. One of the carbohelical diamines (CHTPA) serves the dual function of hole transport as well as emission in simple double‐layer devices; the efficiencies observed were better by quite some margin than those of other emissive helicenes reported. The twisting endows helical diamines with significantly high triplet energies such that they also function as host materials for red and green phosphors, that is, [Ir(btp)2acac] (btp=2‐(2′‐benzothienyl)pyridine; acac=acetylacetonate) and [Ir(ppy)3] (ppy=2‐phenylpyridine), respectively. The results of device fabrications demonstrate how helicity/ helical scaffold may be diligently exploited to create molecular systems for maneuvering diverse applications in OLEDs.
Dependence of Mesomorphic Behaviour of Methylene‐Linked Dimers and the Stability of the NTB/NX Phase upon Choice of Mesogenic Units and Terminal Chain Length
Authors: Mandle Richard J. , Goodby John W. 
Published: May 2016

AbstractTwelve symmetrical dimeric materials consisting of a nonamethylene (C9) spacer and either phenyl 4‐(4′‐alkylphenyl)benzoate, phenyl 4‐(4′‐alkylcyclohexyl)benzoate or phenyl 4‐(4′‐alkylbicyclohexyl)carboxylate mesogenic units were prepared and their mesogenic behaviour characterised by POM, DSC and XRD. All of the materials exhibited nematic phases with clearing points in excess of 200 °C. Four compounds were found to exhibit the twist‐bend nematic phase, with one material exhibiting a transition from the NTB phase into an anticlinic smectic ‘X’ phase. Across all three series of compounds the length of terminal chain is seen to dictate, to some degree, the type of mesophase formed: shorter terminal chains favour nematic and NTB mesophases, whereas longer terminal aliphatic chains were found to promote smectic phases.
Iron(III)‐Catalyzed Arylation of Spiro‐Epoxyoxindoles with Phenols/Naphthols towards the Synthesis of Spirocyclic Oxindoles
Authors: Luo Mupeng , Yuan Rongju , Liu Xuesong , Yu Linqian , Wei Wanguo 
Published: May 2016

AbstractAn efficient and highly regioselective iron(III)‐catalyzed Friedel–Crafts‐type arylation of spiro‐epoxyoxindoles with phenols was developed for rapid access to 3‐(3‐indolyl)‐oxindole‐3‐methanols, which could be further elaborated into benzofuranyl‐spirooxindoles under Mitsunobu conditions. When spiro‐epoxyoxindoles were reacted with naphthols in the presence of a catalytic amount of FeCl3⋅6 H2O in dichloromethane, they underwent a tandem Friedel–Crafts‐type arylation and O‐cyclization to yield novel naphthofuranyl‐spirooxindoles in excellent yields. This method is applied to enable the efficient and highly regioselective synthesis of a small‐molecule inhibitor of the sodium channel Nav1.7 (±)‐XEN402, which is currently in a phase IIb clinical trial for the treatment of pain.
Enhanced Fluorescence Turn‐on Imaging of Hypochlorous Acid in Living Immune and Cancer Cells
Authors: Mulay Sandip V. , Choi Minsuk , Jang Yoon Jeong , Kim Youngsam , Jon Sangyong , Churchill David G. 
Published: May 2016

AbstractTwo closely related phenyl selenyl based boron‐dipyrromethene (BODIPY) turn‐on fluorescent probes for the detection of hypochlorous acid (HOCl) were synthesized for studies in chemical biology; emission intensity is modulated by a photoinduced electron‐transfer (PET) process. Probe 2 intrinsically shows a negligible background signal; however, after reaction with HOCl, chemical oxidation of selenium forecloses the PET process, which evokes a significant increase in fluorescence intensity. The fluorescence intensity of probes 1 and 2 with HOCl involves an ∼18 and ∼50‐fold enhancement compared with the respective responses from other reactive oxygen/nitrogen species (ROS/RNS) and low detection limits (30.9 nm for 1 and 4.5 nm for 2). Both probes show a very fast response with HOCl; emission intensity reached a maximum within 1 s. These probes show high selectivity for HOCl, as confirmed by confocal microscopy imaging when testing with RAW264.7 and MCF‐7 cells.
Enantiospecific Synthesis and Cytotoxicity Evaluation of Oximidine II Analogues
Authors: Schneider Christopher M. , Li Wei , Khownium Kriangsak , Lushington Gerald H. , Georg Gunda I. 
Published: May 2016

AbstractAnalogues of the anticancer natural product oximidine II were prepared and evaluated for cytotoxicity. One analogue of oximidine II that carries a C15 allylic amide side chain as well as two analogues with C15 vinyl sulfone side chains were found to lack cytotoxicity against the cancer cell line SK‐Mel‐5, thereby confirming the necessity of the C15 enamide side chain of oximidine II for cytotoxicity. Four analogues, designed by comparative molecular similarity index analysis (CoMSIA), that feature a less complex macrolactone scaffold were prepared and tested. The two analogues carrying a C15 vinyl sulfone group and the two analogues with a C15 oximidine II enamide side chain showed weak cytotoxicity against the SK‐Mel‐5 cell line and other cell lines, indicating that the designed simplified macrocycles cannot replace the oximidine II macrocycle.
Codon 13 KRAS mutation predicts patterns of recurrence in patients undergoing hepatectomy for colorectal liver metastases
Authors: Margonis Georgios A. , Kim Yuhree , Sasaki Kazunari , Samaha Mario , Amini Neda , Pawlik Timothy M. 
Published: May 2016

BACKGROUNDInvestigations regarding the impact of tumor biology after surgical management of colorectal liver metastasis have focused largely on overall survival. We investigated the impact of codon‐specific KRAS mutations on the rates and patterns of recurrence in patients after surgery for colorectal liver metastasis (CRLM).METHODSAll patients who underwent curative‐intent surgery for CRLM between 2002 and 2015 at Johns Hopkins who had available data on KRAS mutation status were identified. Clinico‐pathologic data, recurrence patterns, and recurrence‐free survival (RFS) were assessed using univariable and multivariable analyses.RESULTSA total of 512 patients underwent resection only (83.2%) or resection plus radiofrequency ablation (16.8%). Although 5‐year overall survival was 64.6%, 284 (55.5%) patients recurred with a median RFS time of 18.1 months. The liver was the initial recurrence site for 181 patients, whereas extrahepatic recurrence was observed in 162 patients. Among patients with an extrahepatic recurrence, 102 (63%) had a lung recurrence. Although overall KRAS mutation was not associated with overall RFS (P = 0.186), it was independently associated with a worse extrahepatic (P = 0.004) and lung RFS (P = 0.007). Among patients with known KRAS codon‐specific mutations, patients with codon 13 KRAS mutation had a worse 5‐year extrahepatic RFS (P = 0.01), whereas codon 12 mutations were not associated with extrahepatic (P = 0.11) or lung‐specific recurrence rate (P = 0.24). On multivariable analysis, only codon 13 mutation independently predicted worse overall extrahepatic RFS (P = 0.004) and lung‐specific RFS (P = 0.023).CONCLUSIONSAmong patients undergoing resection of CRLM, overall KRAS mutation was not associated with RFS. KRAS codon 13 mutations, but not codon 12 mutations, were associated with a higher risk for overall extrahepatic recurrence and lung‐specific recurrence. Cancer 2016. © 2016 American Cancer Society. Cancer 2016;122:2698–2707. © 2016 American Cancer Society.
Distinct subcellular localization of alternative splicing variants of EFA6D, a guanine nucleotide exchange factor for Arf6, in the mouse brain
Authors: Fukaya Masahiro , Ohta Shingo , Hara Yoshinobu , Tamaki Hideaki , Sakagami Hiroyuki 
Published: May 2016

ABSTRACTEFA6D (guanine nucleotide exchange factor for ADP‐ribosylation factor 6 [Arf6]D) is also known as EFA6R, Psd3, and HCA67. It is the fourth member of the EFA6 family with guanine nucleotide exchange activity for Arf6, a small guanosine triphosphatase (GTPase) that regulates endosomal trafficking and actin cytoskeleton remodeling. We propose a classification and nomenclature of 10 EFA6D variants deposited in the GenBank database as EFA6D1a, 1b, 1c, 1d, 1s, 2a, 2b, 2c, 2d, and 2s based on the combination of N‐terminal and C‐terminal insertions. Polymerase chain reaction analysis showed the expression of all EFA6D variants except for variants a and d in the adult mouse brain. Immunoblotting analysis with novel variant‐specific antibodies showed the endogenous expression of EFA6D1b, EFA6D1c, and EFA6D1s at the protein level, with the highest expression being EFA6D1s, in the brain. Immunoblotting analysis of forebrain subcellular fractions showed the distinct subcellular distribution of EFA6D1b/c and EFA6D1s. The immunohistochemical analysis revealed distinct but overlapping immunoreactive patterns between EFA6D1b/c and EFA6D1s in the mouse brain. In immunoelectron microscopic analyses of the hippocampal CA3 region, EFA6D1b/c was present predominantly in the mossy fiber axons of dentate granule cells, whereas EFA6D1s was present abundantly in the cell bodies, dendritic shafts, and spines of hippocampal pyramidal cells. These results provide the first anatomical evidence suggesting the functional diversity of EFA6D variants, particularly EFA6D1b/c and EFA6D1s, in neurons. J. Comp. Neurol. 524:2531–2552, 2016. © 2016 Wiley Periodicals, Inc.
Hematite Surface Activation by Chemical Addition of Tin Oxide Layer
Authors: Carvalho Waldemir M. , Souza Flavio L. 
Published: May 2016

AbstractIn this study, the effect of tin (Sn4+) modification on the surface of hematite electrodes synthesized by an aqueous solution route at different times (2, 5, 10, 18, and 24 h) is investigated. As confirmed from X‐ray diffraction results, the as‐synthesized electrode exhibits an oxyhydroxide phase, which is converted into a pure hematite phase after being subjected to additional thermal treatment at 750 °C for 30 min. The tin‐modified hematite electrode is prepared by depositing a solution of Sn4+ precursor on the as‐synthesized electrode, followed by thermal treatment under the same abovementioned conditions. This modification results in an enhancement of the photocurrent response for all hematite electrodes investigated and attains the highest values of around 1.62 and 2.3 mA cm−2 at 1.23 and 1.4 V versus RHE, respectively, for electrodes obtained in short synthesis times (2 h). Contact angle measurements suggest that the deposition of Sn4+ on the hematite electrode provides a more hydrophilic surface, which favors a chemical reaction at the interface between the electrode and electrolyte. This result generates new perspectives for understanding the deposition of Sn4+ on the hematite electrode surface, which is in contrast with several studies previously reported; these studies state that the enhancement in photocurrent density is related to either the induction of an increased donor charge density or shift in the flat‐band potential, which favors charge separation.
Fe/Fe3C/N‐Doped Carbon Materials from Metal–Organic Framework Composites as Highly Efficient Oxygen Reduction Reaction Electrocatalysts
Authors: Qian Yuhong , Cavanaugh Jack , Khan Inayat Ali , Wang Xuerui , Peng Yongwu , Hu Zhigang , Wang Yuxiang , Zhao Dan 
Published: May 2016

AbstractA series of Fe/Fe3C‐containing N‐doped porous carbon materials (Fe/NC) were prepared by pyrolyzing composites that contained a metal–organic framework (MIL‐88c‐Fe) with dicyandiamide. The Fe/NC obtained at 800 °C (Fe/NC800) showed comparable onset potential and kinetics to that of the commercial Pt/C catalyst in catalyzing the oxygen reduction reaction (ORR). Further measurements suggested that it has better durability and much higher methanol tolerance than Pt/C. Acid leaching was performed to reveal the critical role of Fe‐containing sites in ORR catalysis.
Homogeneous Photocatalytic H2 Production Using a RuII Bathophenanthroline Metal‐to‐Ligand Charge‐Transfer Photosensitizer
Authors: Khnayzer Rony S. , Olaiya Babatunde S. , El Roz Karim A. , Castellano Felix N. 
Published: May 2016

AbstractThe prototypical [Ru(bpy)3]2+ (bpy=2,2′‐bipyridine) photosensitizer has been previously demonstrated to be labile in aqueous photocatalytic solutions, especially in the presence of coordinating electron donors. Here, an alternative RuII molecular sensitizer, [Ru(dpp)3]2+ (dpp=4,7‐diphenyl‐1,10‐phenanthroline or bathophenanthroline), is described, which is considerably more stable than its bpy congener, allowing enhanced photocatalysis metrics in conjunction with a cobalt glyoxime ([Co(dmgH)2pyCl], dmgH=dimethylglyoxime, py=pyridine) water reduction catalyst and N,N‐dimethyl‐p‐toluidine (DMT) as the sacrificial donor in a 1:1 mixture of CH3CN/H2O. Photoluminescence studies revealed that DMT reductively quenches the excited state of [Ru(dpp)3]2+ with a bimolecular rate constant of kq=4.9×109 m−1 s−1. The rate constant measured for electron transfer from the reduced sensitizer to the [Co(dmgH)2pyCl] was found to be near the diffusion limit, kCo=2.4×109 m−1 s−1. H2 production by photocatalysis was independently monitored by using a high‐throughput photochemical reactor equipped with pressure transducers, gas chromatogram, and a mass spectrometer for detection; this illustrated that the composition yields high turnover numbers (TONs), approaching 10 000 (H2/Ru) with respect to the sensitizer and deuteration studies using D2O confirmed that H2 is primarily produced from protons derived from water in these systems.
Broadband matching via reflection function optimization
Authors: Şengül Metin 
Published: May 2016

SummaryIn this paper, a practical approach is presented for designing broadband matching networks via reflection function optimization. In the proposed algorithm, the input or output reflection function of the matching network is expressed in terms of three real polynomials describing the matching network, load and generator reflection coefficients. Next one of the polynomials is optimized to get minimum reflection function values in the passband. Then matching network topology and element values are obtained via the formed input reflection coefficient expression. Two examples are presented to explain the usage of the new approach. Copyright © 2016 John Wiley & Sons, Ltd.