bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Insight in Copper‐Ion Binding to Human Islet Amyloid: The Contribution of Metal‐Complex Speciation To Reveal the Polypeptide Toxicity
Authors: Magrì Antonio , La Mendola Diego , Nicoletti Vincenzo Giuseppe , Pappalardo Giuseppe , Rizzarelli Enrico 
Published: August 2016

AbstractType‐2 diabetes (T2D) is considered to be a potential threat on a global level. Recently, T2D has been listed as a misfolding disease, such as Alzheimer's and Parkinson's diseases. Human islet amyloid polypeptide (hIAPP) is a molecule cosecreted in pancreatic β cells and represents the main constituent of an aggregated amyloid found in individuals affected by T2D. The trace‐element serum level is significantly influenced during the development of diabetes. In particular, the dys‐homeostasis of Cu2+ ions may adversely affect the course of the disease. Conflicting results have been reported on the protective role played by complex species formed by Cu2+ ions with hIAPP or its peptide fragments in vitro. The histidine (His) residue at position 18 represents the main binding site for the metal ion, but contrasting results have been reported on other residues involved in metal‐ion coordination, in particular those toward the N or C terminus. Sequences that encompass regions 17–29 and 14–22 were used to discriminate between the two models of the hIAPP coordination mode. Due to poor solubility in water, poly(ethylene glycol) (PEG) derivatives were synthesized. A peptide fragment that encompasses the 17–29 region of rat amylin (rIAPP) in which the arginine residue at position 18 was substituted by a histidine residue was also obtained to assess that the PEG moiety does not alter the peptide secondary structure. The complex species formed by Cu2+ ions with Ac‐PEG‐hIAPP(17–29)‐NH2, Ac‐rIAPP(17–29)R18H‐NH2, and Ac‐PEG‐hIAPP(14–22)‐NH2 were studied by using potentiometric titrations coupled with spectroscopic methods (UV/Vis, circular dichroism, and EPR). The combined thermodynamic and spectroscopic approach allowed us to demonstrate that hIAPP is able to bind Cu2+ ions starting from the His18 imidazole nitrogen atom toward the N‐terminus domain. The stability constants of copper(II) complexes with Ac‐PEG‐hIAPP(14–22)‐NH2 were used to simulate the different experimental conditions under which aggregate formation and oxidative stress of hIAPP has been reported. Speciation unveils: 1) the protective role played by increased amounts of Cu2+ ions on the hIAPP fibrillary aggregation, 2) the effect of adventitious trace amounts of Cu2+ ions present in phosphate‐buffered saline (PBS), and 3) a reducing fluorogenic probe on H2O2 production attributed to the polypeptide alone.
[62]Tetradecaphyrin and Its Mono‐ and Bis‐ZnII Complexes
Authors: Yoneda Tomoki , Soya Takanori , Neya Saburo , Osuka Atsuhiro 
Published: August 2016

AbstractA coiled structure of meso‐pentafluorophenyl‐substituted [62]tetradecaphyrin 1 was revealed by X‐ray structural analysis. Synthetic protocols were devised to form mono‐ and bis‐ZnII complexes, 1 Zn and 1 Zn2, selectively. The former displayed a trigonal‐bipyramidal pentacoordinated ZnII ion as a rare case and a cyclic voltammogram exhibiting eleven reversible redox waves. The latter showed a Ci‐symmetric structure with modest Hückel aromaticity owing to a 62 π‐electronic circuit as the largest aromatic molecule to date.
ChemInform Abstract: Ln2Ga[B3O6(OH)]2 [B7O9(OH)2] (CH3CO2)2 (Ln: Y, Sm, Eu, Gd, Dy): A Series of Lanthanide Galloborates Decorated by Acetate Anions.
Authors: Yang Hui , Hu Chun‐Li , Mao Jiang‐Gao 
Published: August 2016

AbstractLn2Ga[B3O6(OH)]2 [B7O9(OH)2](OAc)2 (Ln: Y (I), Sm (II), Eu (III), Gd (IV), Dy (V)) are prepared by hydrothermal reaction of a 1:1:2:1 molar mixture of Ln2O3, Ga(NO3)3, H3BO3, and (NH4)2B10O16 in aq.
ChemInform Abstract: Pentavalent Lanthanide Compounds: Formation and Characterization of Praseodymium(V) Oxides.
Authors: Zhang Qingnan , Hu Shu‐Xian , Qu Hui , Su Jing , Wang Guanjun , Lu Jun‐Bo , Chen Mohua , Zhou Mingfei , Li Jun 
Published: August 2016

AbstractThe complex (μ2‐O2)PrO2 and the linear core‐containing PrO2+ complexes are observed both in the gas phase by laser vaporization of Pr in He2 seeded with a pulsed 30—40% O2 stream (1‐1.2 MPa) and in solid Ar matrices analyzed by matrix isolation IR and IR photodissociation spectroscopy (0.2—0.5 mJ/pulse, 850—1600 cm‐1) with TOF‐MS‐selected [(PrO2)+(O2)n] cations.
ChemInform Abstract: The Two‐Dimensional Anion [Sb6Se10]2‐: Solvothermal Synthesis, Crystal Structure, and Properties of an Iron Selenidoantimonate(III) [Fe(phen)3]Sb6Se10.
Authors: Shen Yali , Liu Yun , Liu Shuzhen , Sun Peipei , Tang Chunying , Han Jingyu , Jia Dingxian 
Published: August 2016

Abstract[Fe(phen)3]Sb6Se10 is prepared by solvothermal reaction of a 1:2:6 molar mixture of Fe, Sb, Se with phen and DABCO in MeOH/H2O (3:1) mixed solvent (autoclave, 150 °C, 6 d).
ChemInform Abstract: HOTf‐Catalyzed Sustainable One‐Pot Synthesis of Benzene and Pyridine Derivatives under Solvent‐Free Conditions.
Authors: Zhang Xu , Wang Zhiqiang , Xu Kun , Feng Yuquan , Zhao Wei , Xu Xuefeng , Yan Yanlei , Yi Wei 
Published: August 2016

AbstractTitle compounds are efficiently synthesized using a versatile TfOH‐catalyzed and solvent‐free system.
ChemInform Abstract: Aerobic Copper‐Promoted Radical‐Type Cleavage of Coordinated Cyanide Anion: Nitrogen Transfer to Aldehydes to Form Nitriles.
Authors: Wu Qian , Luo Yi , Lei Aiwen , You Jingsong 
Published: August 2016

AbstractA new cleavage pattern for the cyanide ion is observed in this copper‐promoted CN‐triple bond cleavage of a coordinated cyanide anion in the presence of oxygen.
ChemInform Abstract: A Highly Stereoselective, Catalytic Four‐Component Synthesis of Dispiroindolo‐Pyrrolidines/‐Imidazolidines via Azomethine Ylides.
Authors: Muthusamy Sengodagounder , Kumar Singaravelan Ganesh 
Published: August 2016

AbstractThe regio‐, chemo‐, and diastereoselective title reaction between diazoamides, amines, aldehydes, and exomethylenes or imines succeeds in high yields.
ChemInform Abstract: Enantioselective Intramolecular Cyclization of Alkynyl Esters Catalyzed by a Chiral Broensted Base.
Authors: Kondoh Azusa , Tran Hoa Thi Quynh , Kimura Kyoko , Terada Masahiro 
Published: August 2016

AbstractAn enantioselective intramolecular cyclization of alkynyl esters yields dibenzofurans by employing a Broensted base catalyst generated in situ from a chiral Schiff base and tBuOK.
ChemInform Abstract: Exploiting the Bis‐Nucleophilicity of α‐Aminoboronates: Copper‐Catalyzed, Intramolecular Aminoalkylations of Bromobenzoyl Chlorides.
Authors: Dumas Aaron M. , Sieradzki Adrian J. , Donnelly Liam J. 
Published: August 2016

AbstractAn acylation/arylation cascade, utilizing 2‐bromobenzoyl chlorides as bis‐electrophiles in the reaction with α‐aminoboronates, provides isoindolinones.
ChemInform Abstract: A Direct Access to 7‐Aminoindoles via Iridium‐Catalyzed Mild C—H Amidation of N‐Pivaloylindoles with Organic Azides.
Authors: Kim Youyoung , Park Juhyeon , Chang Sukbok 
Published: August 2016

AbstractA straightforward protocol towards biologically important 7‐aminoindoles is developed.
ChemInform Abstract: A Palladium‐Catalyzed Double Carbonylation Approach to Isatins from 2‐Iodoanilines.
Authors: Laursen Simon R. , Jensen Mikkel T. , Lindhardt Anders T. , Jacobsen Mikkel F. , Skrydstrup Troels 
Published: August 2016

AbstractThe Pd‐catalyzed double carbonylation of 2‐iodoanilines using nearly stoichiometric amounts of CO, generated ex situ from solid CO‐surrogate SilaCogen, followed by acid promoted cyclization of intermediates (IV) affords isatine derivatives.
ChemInform Abstract: Catalytic Stereoselective Cascade Reactions of Quinols with Trifluoromethyl Ketones: Direct Access to CF3‐Containing 1,3‐Dioxolanes.
Authors: Li Feng , Wang Jingjing , Xu Mengmeng , Zhao Xiaobo , Zhou Xiaohong , Zhao Wen‐Xian , Liu Lantao 
Published: August 2016

AbstractThe products are obtained in high yields and with moderate to high diastereoselectivities.
ChemInform Abstract: Fe‐Catalyzed Synthesis of Substituted N‐Aryl Oxazolidines.
Authors: Murru Siva , Lott Charles Seth , McGough Brandon , Bernard Dakota M. , Srivastava Radhey S. 
Published: August 2016

AbstractThe reaction between allyl alcohols, paraformaldehyde, and aryl hydroxylamines provides 3‐aryl‐4‐propenyl oxazolidines in high yields which may be demethylenated to the corresponding allylamino alcohols in a one‐pot manner.
ChemInform Abstract: Copper(I)‐Catalyzed 3‐Position Methylation of Coumarins by Using Di‐tert‐butyl Peroxide as the Methylation Reagents.
Authors: Zhuang Huan , Zeng Runsheng , Zou Jianping 
Published: August 2016

AbstractThis novel methodology for the 3‐methylation of coumarins proceeds via a radical mechanism and tolerates a wide range of functional groups.
ChemInform Abstract: Multicomponent Access to Indolo[3,3a‐c]isoquinolin‐3,6‐diones: Formal Synthesis of (.+‐.)‐Plicamine.
Authors: Mijangos Marco V. , Miranda Luis D. 
Published: August 2016

AbstractA four component Ugi reaction followed by a one‐pot two‐step oxidative phenol coupling/Michael addition sequence offers access to seventeen indolo[3,3a‐c]isoquinolin‐3,6‐diones, isolated as a syn/anti mixture of diastereomers.
ChemInform Abstract: Rh(III)‐Catalyzed Relay Carbenoid Functionalization of Aromatic C—H Bonds: Access to π‐Conjugated Fused Heteroarenes.
Authors: Xie Ying , Chen Xun , Liu Xin , Su Shi‐Jian , Li Jianzhang , Zeng Wei 
Published: August 2016

AbstractA novel Rh(III)‐catalyzed cross‐coupling/cyclization cascade between arylketoimines and diazoesters is described.
ChemInform Abstract: Broensted Acid‐Catalyzed Chemodivergent Reactions of ortho‐Mercaptobenzyl Alcohols with 3‐Alkyl‐2‐vinylindoles and Styrenes: [5 + 2] Cyclization versus Hydroxysulfenylation.
Authors: Zhao Jia‐Jia , Tang Man , Zhang Hong‐Hao , Xu Meng‐Meng , Shi Feng 
Published: August 2016

AbstractThe BNPA‐catalyzed reaction of 2‐mercaptobenzyl alcohols (II) with 2‐vinylindoles (I) leads to benzoxathiepines (III), whilst reactions with indene (IV) and alkenes (VI) under similar conditions give rise to corresponding β‐hydroxy sulfides.
ChemInform Abstract: Intermolecular Three‐Component Arylsilylation of Alkynes under Palladium/Copper Cooperative Catalysis.
Authors: Shintani Ryo , Kurata Hiroki , Nozaki Kyoko 
Published: August 2016

AbstractAn efficient syn‐selective carbosilylation of internal aryl or alkyl substituted alkynes with aryl, hetaryl or alkyl bromides and dimethylphenylsilyl boronic acid pinacol ester is described.
ChemInform Abstract: Aryne‐Induced Dearomatized Phosphonylation of Electron‐Deficient Azaarenes.
Authors: Liu Kai , Liu Li‐Li , Gu Cheng‐Zhi , Dai Bin , He Lin 
Published: August 2016

AbstractAzaarenes such as (iso)quinolines, phenanthroline, and acridine are dearomatized via multicomponent reaction with arynes and dialkylphosphites to give corresponding dearomatized phosphonylated heterocycles.
ChemInform Abstract: Diketopiperazines from Costa Rican Endolichenic Fungus Colpoma sp. CR1465A
Authors: Lee Seulah , Tamayo‐Castillo Giselle , Pang Changhyun , Clardy Jon , Cao Shugeng , Kim Ki Hyun 
Published: August 2016

Abstractisolation, structure elucidation, antifungal and antimicrobial properties of three new diketopiperazines (I)—(III) along with five known diketopiperazines
ChemInform Abstract: Photovoltaics with Ferroelectrics: Current Status and Beyond
Authors: Paillard Charles , Bai Xiaofei , Infante Ingrid C. , Guennou Mael , Geneste Gregory , Alexe Marin , Kreisel Jens , Dkhil Brahim 
Published: August 2016

AbstractReview: 114 refs.
Structural basis for cholinergic regulation of neural circuits in the mouse olfactory bulb
Authors: Hamamoto Masakazu , Kiyokage Emi , Sohn Jaerin , Hioki Hiroyuki , Harada Tamotsu , Toida Kazunori 
Published: August 2016

ABSTRACTOdor information is regulated by olfactory inputs, bulbar interneurons, and centrifugal inputs in the olfactory bulb (OB). Cholinergic neurons projecting from the nucleus of the horizontal limb of the diagonal band of Broca and the magnocellular preoptic nucleus are one of the primary centrifugal inputs to the OB. In this study, we focused on cholinergic regulation of the OB and analyzed neural morphology with a particular emphasis on the projection pathways of cholinergic neurons. Single‐cell imaging of a specific neuron within dense fibers is critical to evaluate the structure and function of the neural circuits. We labeled cholinergic neurons by infection with virus vector and then reconstructed them three‐dimensionally. We also examined the ultramicrostructure of synapses by electron microscopy tomography. To further clarify the function of cholinergic neurons, we performed confocal laser scanning microscopy to investigate whether other neurotransmitters are present within cholinergic axons in the OB. Our results showed the first visualization of complete cholinergic neurons, including axons projecting to the OB, and also revealed frequent axonal branching within the OB where it innervated multiple glomeruli in different areas. Furthermore, electron tomography demonstrated that cholinergic axons formed asymmetrical synapses with a morphological variety of thicknesses of the postsynaptic density. Although we have not yet detected the presence of other neurotransmitters, the range of synaptic morphology suggests multiple modes of transmission. The present study elucidates the ways that cholinergic neurons could contribute to the elaborate mechanisms involved in olfactory processing in the OB. J. Comp. Neurol. 525:574–591, 2017. © 2016 Wiley Periodicals, Inc.
Ion Dynamics in a Mixed‐Cation Alkoxy‐Ammonium Ionic Liquid Electrolyte for Sodium Device Applications
Authors: Pope Cameron R. , Kar Mega , MacFarlane Douglas R. , Armand Michel , Forsyth Maria , O'Dell Luke A. 
Published: August 2016

AbstractThe ion dynamics in a novel sodium‐containing room‐temperature ionic liquid (IL) consisting of an ether‐functionalised quaternary ammonium cation and bis(trifluoromethylsulfonyl)amide [NTf2] anion with various concentrations of Na[NTf2] have been characterised using differential scanning calorimetry, impedance spectroscopy, diffusometry and NMR relaxation measurements. The IL studied has been specifically designed to dissolve a relatively large concentration of Na[NTf2] salt (over 2 mol kg−1) as this has been shown to improve ion transport and conductivity. Consistent with other studies, the measured ionic conductivity and diffusion coefficients show that the overall ionic mobility decreases with decreasing temperature and increasing salt content. NMR relaxation measurements provide evidence for correlated dynamics between the ether‐functionalised ammonium and Na cations, possibly with the latter species acting as cross‐links between multiple ammonium cations. Finally, preliminary cyclic voltammetry experiments show that this IL can undergo stable electrochemical cycling and could therefore be potentially useful as an electrolyte in a Na‐based device.
Oil‐in‐Water Emulsions Stabilized by Carboxymethylated Lignins: Properties and Energy Prospects
Authors: Li Shuai , Willoughby Julie A. , Rojas Orlando J. 
Published: August 2016

AbstractWe take advantage of the amphiphilic properties of technical lignin macromolecules and their inherent high calorific values to formulate oil‐in‐water (O/W) fuel emulsions with high internal‐phase ratios. For the oil phase, we used a combustible hydrocarbon (kerosene) with a measured equivalent alkane carbon number of 12. To adjust the balance of affinity with the oil and water phases and their surface activity, pine kraft lignins were carboxymethylated to different degrees, as quantified by13C NMR spectroscopy, potentiometric titrations, and zeta potential measurements. Carboxymethylated lignins (CMLs) with a degree of substitution of 30 % displayed a critical aggregation concentration of 3 %. The salinity and pH of the aqueous phase were chosen as formulation variables and adjusted within the Winsor framework. The O/W emulsions were produced by following standard protocols. The drop‐size distributions of emulsions with varying pH, degree of substitution, and composition (water‐to‐oil ratio, WOR) were determined, and the long‐term stabilities and rheological behavior of these emulsions were analyzed. Most of the obtained O/W fuel emulsions showed shear‐thinning behavior with a drop size of approximately 2.5 μm and were stable for over 30 days. The combustion of the lignins and their respective emulsions was performed, and their higher heating values (HHVs) were quantified. The HHVs of CML and a high‐internal‐phase (WOR=30:70) O/W emulsion were 20 and 30 MJ kg−1, respectively. Overall, we propose the stabilization of O/W fuel emulsions by lignin as an important avenue in the utilization of this abundant biomacromolecule.
Smart, Sustainable, and Ecofriendly Chemical Design of Fully Bio‐Based Thermally Stable Thermosets Based on Benzoxazine Chemistry
Authors: Froimowicz Pablo , R. Arza Carlos , Han Lu , Ishida Hatsuo 
Published: August 2016

AbstractInvited for this month′s cover are the groups at the Department of Macromolecular Science and Engineering, from Case Western Reserve University (CWRU), and Design and Chemistry of Macromolecules Group, from Institute of Technology in Polymers and Nanotechnology (ITPN), directed by Prof. Dr. Hatsuo Ishida and Prof. Dr. Pablo Froimowicz, respectively. The image symbolizes how in the ever‐growing ′Universe of Benzoxazines′ there is always room for new discoveries. The Full Paper itself is available at 10.1002/cssc.201600577.
A cross‐continental comparison of plant and beetle responses to retention of forest patches during timber harvest
Authors: Baker Susan C. , Halpern Charles B. , Wardlaw Timothy J. , Kern Christel , Edgar Graham J. , Thomson Russell J. , Bigley Richard E. , Franklin Jerry F. , Gandhi Kamal J. K. , Gustafsson Lena , Johnson Samuel , Palik Brian J. , Spies Thomas A. , Steel E. Ashley , Weslien Jan , Strengbom Joachim 
Published: August 2016

AbstractTimber harvest can adversely affect forest biota. Recent research and application suggest that retention of mature forest elements (retention forestry), including unharvested patches (or aggregates) within larger harvested units, can benefit biodiversity compared to clearcutting. However, it is unclear whether these benefits can be generalized among the diverse taxa and biomes in which retention forestry is practiced. Lack of comparability in methods for sampling and analyzing responses to timber harvest and edge creation presents a challenge to synthesis. We used a consistent methodology (similarly spaced plots or traps along transects) to investigate responses of vascular plants and ground‐active beetles to aggregated retention at replicate sites in each of four temperate and boreal forest types on three continents: Douglas‐fir forests in Washington, USA; aspen forests in Minnesota, USA; spruce forests in Sweden; and wet eucalypt forests in Tasmania, Australia. We assessed (1) differences in local (plot‐scale) species richness and composition between mature (intact) and regenerating (previously harvested) forest; (2) the lifeboating function of aggregates (capacity to retain species of unharvested forest); and whether intact forests and aggregates (3) are susceptible to edge effects and (4) influence the adjacent regenerating forest. Intact and harvested forests differed in composition but not richness of plants and beetles. The magnitude of this difference was generally similar among regions, but there was considerable heterogeneity of composition within and among replicate sites. Aggregates within harvest units were effective at lifeboating for both plant and beetle communities. Edge effects were uncommon even within the aggregates. In contrast, effects of forest influence on adjacent harvested areas were common and as strong for aggregates as for larger blocks of intact forest. Our results provide strong support for the widespread application of aggregated retention in boreal and temperate forests. The consistency of pattern in four very different regions of the world suggests that, for forest plants and beetles, responses to aggregated retention are likely to apply more widely. Our results suggest that through strategic placement of aggregates, it is possible to maintain the natural heterogeneity and biodiversity of mature forests managed for multiple objectives.
Explicit modeling of abiotic and landscape factors reveals precipitation and forests associated with aphid abundance
Authors: Stack Whitney Kaitlin , Meehan Timothy D. , Kucharik Christopher J. , Zhu Jun , Townsend Philip A. , Hamilton Krista , Gratton Claudio 
Published: August 2016

AbstractIncreases in natural or noncrop habitat surrounding agricultural fields have been shown to be correlated with declines in insect crop pests. However, these patterns are highly variable across studies suggesting other important factors, such as abiotic drivers, which are rarely included in landscape models, may also contribute to variability in insect population abundance. The objective of this study was to explicitly account for the contribution of temperature and precipitation, in addition to landscape composition, on the abundance of a widespread insect crop pest, the soybean aphid (Aphis glycines Matsumura), in Wisconsin soybean fields. We hypothesized that higher soybean aphid abundance would be associated with higher heat accumulation (e.g., growing degree days) and increasing noncrop habitat in the surrounding landscape, due to the presence of the overwintering primary hosts of soybean aphid. To evaluate these hypotheses, we used an ecoinformatics approach that relied on a large dataset collected across Wisconsin over a 9‐year period (2003–2011), for an average of 235 sites per year (n = 2,110 fields total). We determined surrounding landscape composition (1.5‐km radius) using publicly available satellite‐derived land cover imagery and interpolated daily temperature and precipitation information from the National Weather Service COOP weather station network. We constructed linear mixed models for soybean aphid abundance based on abiotic and landscape explanatory variables and applied model averaging for prediction using an information theoretic framework. Over this broad spatial and temporal extent in Wisconsin, we found that variation in growing season precipitation was positively related to soybean aphid abundance, while higher precipitation during the nongrowing season had a negative effect on aphid populations. Additionally, we found that aphid populations were higher in areas with proportionally more forest but were lower in areas where minor crops, such as small grains, were more prevalent. Thus, our findings support our hypothesis that including abiotic drivers increases our understanding of crop pest abundance and distribution. Moreover, by explicitly modeling abiotic factors, we may be able to explore how variable climate in tandem with land cover patterns may affect current and future insect populations, with potentially critical implications for crop yields and agricultural food webs.