bluuebunny/crossref_metadata_2025_split huggingface dataset:
Residue‐Specific Dynamics and Local Environmental Changes in Aβ40 Oligomer and Fibril Formation
Authors: Liu Haiyang , Morris Clifford , Lantz Richard , Kent Thomas W. , Elbassal Esmail A. , Wojcikiewicz Ewa P. , Du Deguo 
Published: May 2018

AbstractElucidating local dynamics of protein aggregation is crucial for understanding the mechanistic details of protein amyloidogenesis. Herein, we studied the residue‐specific dynamics and local environmental changes of Aβ40 along the course of aggregation by using para‐cyanophenylalanine (PheCN) as a fluorescent and vibrational probe. Our results show that the PheCN residues introduced at various positions all exhibited an immediate decay of fluorescence intensity, indicating a relatively synergistic process in early oligomer formation. The fast decreases in the fluorescence intensities of residues 19 and 20 in the central hydrophobic core region and residue 10 in the N‐terminal region suggest that they play crucial roles in the formation of the oligomeric core. The PheCN4 residue exhibits a remarkably slower decrease in fluorescence intensity, implicating its dynamic conformational characteristics in oligomer and fibril formation. Our results also suggest that the N‐terminal residues in fibrils are surrounded by a relatively hydrophobic local environment, as opposed to being solvated.
Synthesis, Characterization, and Functionalization of 1‐Boraphenalenes
Authors: Kahan Rachel J. , Crossley Daniel L. , Cid Jessica , Radcliffe James E. , Ingleson Michael J. 
Published: May 2018

Abstract1‐Boraphenalenes have been synthesized by reaction of BBr3 with 1‐(aryl‐ethynyl)naphthalenes, 1‐ethynylnaphthalene, and 1‐(pent‐1‐yn‐1‐yl)naphthalene and they can be selectively functionalized at boron or carbon to form bench‐stable products. All of these 1‐boraphenalenes have LUMOs localized on the planar C12B core that are closely comparable in character to isoelectronic phenalenyl cations. In contrast to the comparable LUMOs, the aromatic stabilization of the C5B ring in 1‐boraphenalenes is dramatically lower than the C6 rings in phenalenyl cations. This is due to the occupied orbitals of π symmetry being less delocalised in the 1‐boraphenalenes.
A Bimetallic Zn/Fe Polyphthalocyanine‐Derived Single‐Atom Fe‐N4 Catalytic Site:A Superior Trifunctional Catalyst for Overall Water Splitting and Zn–Air Batteries
Authors: Pan Yuan , Liu Shoujie , Sun Kaian , Chen Xin , Wang Bin , Wu Konglin , Cao Xing , Cheong Weng‐Chon , Shen Rongan , Han Aijuan , Chen Zheng , Zheng Lirong , Luo Jun , Lin Yan , Liu Yunqi , Wang Dingsheng , Peng Qing , Zhang Qiang , Chen Chen , Li Yadong 
Published: May 2018

AbstractDeveloping an efficient single‐atom material (SAM) synthesis and exploring the energy‐related catalytic reaction are important but still challenging. A polymerization–pyrolysis–evaporation (PPE) strategy was developed to synthesize N‐doped porous carbon (NPC) with anchored atomically dispersed Fe‐N4 catalytic sites. This material was derived from predesigned bimetallic Zn/Fe polyphthalocyanine. Experiments and calculations demonstrate the formed Fe‐N4 site exhibits superior trifunctional electrocatalytic performance for oxygen reduction, oxygen evolution, and hydrogen evolution reactions. In overall water splitting and rechargeable Zn–air battery devices containing the Fe‐N4 SAs/NPC catalyst, it exhibits high efficiency and extraordinary stability. This current PPE method is a general strategy for preparing M SAs/NPC (M=Co, Ni, Mn), bringing new perspectives for designing various SAMs for catalytic application.
Watura Jurnti: A 42000–45000‐year‐long occupation sequence from the north‐eastern Pilbara
Authors: MARSH MICHAEL , HISCOCK PETER , WILLIAMS DOUGLAS , HUGHES PHILIP , SULLIVAN MARJORIE 
Published: May 2018

ABSTRACTWatura Jurnti (DAA #6287) was first occupied in 42000–45000 BP, with evidence of occupation continuing through the arid LGM and deglacial period to c.15000 BP. There was a very pronounced reduction in both occupation and deposition between c.15000 and 1500 BP. The small size and nature of the stone artefact assemblage indicates that use of the shelter has been intermittent and non‐intensive throughout most of the past 42–45 ka. Watura Jurnti is on an isolated ridge on the northern margin of the Pilbara and its occupational history shows that the more marginal areas of the arid zone, including the sandy and stony deserts of adjacent to the northern Pilbara, were subject to intermittent visitation before, during and after the LGM.
Large‐area high‐resolution ground‐penetrating radar measurements for archaeological prospection
Authors: Trinks Immo , Hinterleitner Alois , Neubauer Wolfgang , Nau Erich , Löcker Klaus , Wallner Mario , Gabler Manuel , Filzwieser Roland , Wilding Julia , Schiel Hannes , Jansa Viktor , Schneidhofer Petra , Trausmuth Tanja , Sandici Vlad , Ruß David , Flöry Sebastian , Kainz Jakob , Kucera Matthias , Vonkilch Alexandra , Tencer Tomáš , Gustavsen Lars , Kristiansen Monica , Bye‐Johansen Lise‐Marie , Tonning Christer , Zitz Thomas , Paasche Knut , Gansum Terje , Seren Sirri 
Published: May 2018

AbstractTraditionally, ground‐penetrating radar (GPR) measurements for near‐surface geophysical archaeological prospection are conducted with single‐channel systems using GPR antennae mounted in a cart similar to a pushchair, or towed like a sledge behind the operator. The spatial data sampling of such GPR devices for the non‐invasive detection and investigation of buried cultural heritage was, with very few exceptions, at best 25 cm in cross‐line direction of the measurement. With two or three persons participating in the fieldwork, coverage rates between a quarter hectare and half a hectare per day are common, while frequently considerably smaller survey areas at often coarse measurement spacing have been reported. Over the past years, the advent of novel multi‐channel GPR antenna array systems has permitted an enormous increase in survey efficiency and spatial sampling resolution. Using GPR antenna arrays with up to 16 channels operating in parallel, in combination with automatic positioning solutions based on real‐time kinematic global navigation satellite systems or robotic total‐stations, it has become possible to map several hectares per day with as little as 8 cm cross‐line and 4 cm in‐line GPR trace spacing. While this dramatic increase in coverage rate has a positive effect on the reduction of costs of GPR surveys, and thus its more widespread use in archaeology, the increased spatial sampling for the first time allows for the high‐resolution imaging of relatively small archaeological structures, such as for example 25 cm wide post‐holes of Iron Age buildings or the brick pillars of Roman floor heating systems, permitting much improved archaeological interpretations of the collected data. We present the state‐of‐the‐art in large‐scale high‐resolution archaeological GPR prospection, covering hardware and software technology and fieldwork methodology as well as the closely related issues of processing and interpretation of the huge data sets. Application examples from selected European archaeological sites illustrate the progress made.
Role of ADAMTS‐12 in Protecting Against Inflammatory Arthritis in Mice By Interacting With and Inactivating Proinflammatory Connective Tissue Growth Factor
Authors: Wei Jian‐lu , Fu Wenyu , Hettinghouse Aubryanna , He Wen‐jun , Lipson Kenneth E. , Liu Chuan‐ju 
Published: May 2018

ObjectiveIt has been reported that ADAMTS‐12 is a susceptibility gene for rheumatoid arthritis (RA) development, and its level is significantly increased in RA patients. In addition, ADAMTS‐12 is reported to be required for inflammation in otherwise healthy subjects. This study was undertaken to determine the role of ADAMTS‐12 and the underlying mechanisms in the pathogenesis of inflammatory arthritis.MethodsThe collagen‐induced arthritis (CIA) model was established in ADAMTS‐12–deficient mice and their control littermates to determine the role of ADAMTS‐12 in vivo. Micro–computed tomography scanning was used to demonstrate the destruction of the ankle joint; histologic analysis illustrated synovitis, pannus formation, and bone and cartilage destruction; enzyme‐linked immunosorbent assay was performed to measure serum levels of inflammatory cytokines; and protein–protein interaction assays were performed to detect the interactions of ADAMTS‐12 and its various deletion mutants with connective tissue growth factor (CTGF).ResultsDeficiency of ADAMTS‐12 led to accelerated inflammatory arthritis in the CIA mouse model. Loss of ADAMTS‐12 caused enhanced osteoclastogenesis. In vitro and in vivo protein–protein interaction assays demonstrated that ADAMTS‐12 bound and processed CTGF, a previously unrecognized substrate of ADAMTS‐12. In addition, deletion of ADAMTS‐12 enhanced, while overexpression of ADMATS‐12 reduced, CTGF‐mediated inflammation. Furthermore, ADAMTS‐12 regulation of inflammation was largely lost in CTGF‐deficient macrophages. Importantly, blocking of CTGF attenuated elevated inflammatory arthritis seen in the ADAMTS‐12–deficient CIA mouse model.ConclusionThis study provides evidence that ADAMTS‐12 is a critical regulator of inflammatory arthritis and that this is mediated, at least in part, through control of CTGF turnover.
Bivariate random‐effects meta‐analysis models for diagnostic test accuracy studies using arcsine‐based transformations
Authors: Negeri Zelalem F. , Shaikh Mateen , Beyene Joseph 
Published: May 2018

AbstractDiagnostic or screening tests are widely used in medical fields to classify patients according to their disease status. Several statistical models for meta‐analysis of diagnostic test accuracy studies have been developed to synthesize test sensitivity and specificity of a diagnostic test of interest. Because of the correlation between test sensitivity and specificity, modeling the two measures using a bivariate model is recommended. In this paper, we extend the current standard bivariate linear mixed model (LMM) by proposing two variance‐stabilizing transformations: the arcsine square root and the Freeman–Tukey double arcsine transformation. We compared the performance of the proposed methods with the standard method through simulations using several performance measures. The simulation results showed that our proposed methods performed better than the standard LMM in terms of bias, root mean square error, and coverage probability in most of the scenarios, even when data were generated assuming the standard LMM. We also illustrated the methods using two real data sets.
Multiple testing with discrete data: Proportion of true null hypotheses and two adaptive FDR procedures
Authors: Chen Xiongzhi , Doerge Rebecca W. , Heyse Joseph F. 
Published: May 2018

AbstractWe consider multiple testing with false discovery rate (FDR) control whenpvalues have discrete and heterogeneous null distributions. We propose a new estimator of the proportion of true null hypotheses and demonstrate that it is less upwardly biased than Storey's estimator and two other estimators. The new estimator induces two adaptive procedures, that is, an adaptive Benjamini–Hochberg (BH) procedure and an adaptive Benjamini–Hochberg–Heyse (BHH) procedure. We prove that the adaptive BH (aBH) procedure is conservative nonasymptotically. Through simulation studies, we show that these procedures are usually more powerful than their nonadaptive counterparts and that the adaptive BHH procedure is usually more powerful than the aBH procedure and a procedure based on randomizedp‐value. The adaptive procedures are applied to a study of HIV vaccine efficacy, where they identify more differentially polymorphic positions than the BH procedure at the same FDR level.
Preparative isolation of ganoderic acid S, ganoderic acid T and ganoderol B from Ganoderma lucidum mycelia by high‐speed counter‐current chromatography
Authors: Feng Na , Wei Yutian , Feng Jie , Tang Qingjiu , Zhang Zhong , Zhang Jingsong , Han Wei 
Published: May 2018

AbstractGanoderic acid S, ganoderic acid T and ganoderal B are the main bioactive triterpenes of Ganoderma lucidum. In this study, mycelia of G. lucidum were obtained by two‐stage fermentation and then extracted by ethanol and petroleum ether sequentially to obtain crude triterpenes. The crude sample was further purified by recycling high‐speed counter‐current chromatography with n‐hexane–ethyl acetate–methanol–water (7:12:11:5, v/v/v/v) as the optimized two‐phase solvent system. A 16.4 mg aliquot of ganoderol B with a purity of 90.4% was separated from 300 mg of the crude sample in a single run. After employing the recycling elution mode of HSCCC with n‐hexane–ethyl acetate–methanol–water (6:10:8:4.5, v/v/v/v) for five cycles, 25.7 mg ganoderic acid T and 3.7 mg ganoderic acid S with purities of 97.8 and 83.0%, respectively, were obtained. The purities of three compounds were determined by high‐performance liquid chromatography and their chemical structures were identified by NMR and MS data.
Sustainable development of small companies: Investors' perspectives
Authors: Siddique Salina P. , Sciulli Nick 
Published: May 2018

AbstractThe aim of this paper is to explore the sustainability choices of a group of investors relating to corporate environmental initiatives and disclosures given a case‐based scenario. Obtaining such an understanding is important because, as per signaling theory, investors' preferences for sustainable development initiatives and disclosures are one of the contributory factors in determining the quality of environmental disclosures. A web‐based survey of a group of investors was conducted. The questionnaire includes a hypothetical case‐based scenario presenting environmental versus economic consequences of pollution prevention initiatives for a small mining company. The findings indicate that a majority (52%) of the respondents failed to choose a dominant proenvironmental or profinancial strategy. The findings imply that making a decision about a sustainable initiative is complex and requires consideration of a range of contextual factors. The findings support the view that given the resource limitations of a small company, compliance with existing regulation is preferred by the investors over competitive advantage and reputation for undertaking prosustainability initiatives. Hence, one implication is that the regulators should examine tightening the current sustainability regulation status for small companies regarding their environmental policies and disclosures.
Synthesis of La and Ce Mixed MnO2 Nanostructure/rGO Composite for Supercapacitor Applications
Authors: Rajagopal Rajesh , Ryu Kwang‐Sun 
Published: May 2018

AbstractThis paper reports the synthesis of MnO2 nanorods by a facile hydrothermal method for supercapacitor applications. Lanthanum and cerium at different weight ratios were mixed to alter the morphology of the MnO2 nanomaterials. The crystalline nature and morphology of the synthesized MnO2 nanocomposites were examined by powder XRD and field emission scanning electron microscopy, respectively. Cyclic voltammetry, charge−discharge measurements, and electrochemical impedance spectroscopy were used to examine the electrochemical performance of La and Ce‐mixed MnO2 nanocomposite. The 1La3Ce−MnO2 nanocomposite electrode exhibited a high specific capacitance of 575.25 F g−1 at a current density of 1 A g−1. Carbon nanotubes, reduced graphene oxide, and activated carbon materials were mixed with the 1La3Ce−MnO2 nanocomposite to improve the electrochemical performance. Among the three different electrodes, the rGO‐mixed 1La3Ce−MnO2 nanocomposite electrode exhibited a relatively high specific capacitance of 951.25 F g−1 with a high energy density of 84.56 Wh kg−1 at a current density of 1 A g−1. A rGO@1La3Ce−MnO2/rGO@1La3Ce−MnO2 symmetric supercapacitor device was also fabricated and its electrochemical behavior was studied. The analyses showed that the rGO‐mixed 1La3Ce−MnO2 nanocomposite is a suitable material for supercapacitor electrode fabrication.
The Cooperativity of Fe3O4 and Metal‐Organic Framework as Multifunctional Nanocomposites for Laser Desorption Ionization Process
Authors: Fu Chung‐Wei , Lirio Stephen , Shih Yung‐Han , Liu Wan‐Ling , Lin Chia‐Her , Huang Hsi‐Ya 
Published: May 2018

AbstractA novel and facile strategy in developing a water stable magnetic metal‐organic framework nanocomposite (Fe3O4@MOF) is herein reported, in which a Keggin polyoxometalate, phosphotungstic acid (HPW), was encapsulated within the MOF framework via one‐pot synthesis method. The combination of HPW‐embedded MOF and Fe3O4 endowed the composite with high surface area, strong UV absorption, good hydrophilicity, and enhanced water stability. With these unique properties, the Fe3O4@MOF embedded HPW served as adsorbent as well as matrix for SALDI‐MS (surface‐assisted laser desorption ionization mass spectrometry) analysis of polar and non‐polar compounds. The synergistic effect of Fe3O4 and MOF showed an interference‐free background at low mass region than the pristine MOF or Fe3O4 counterparts. This simple approach can be used as new platform in developing magnetic MOF composites without the time consuming and labor‐intensive preparation.
Effect of Single‐walled Carbon Nanotube (SWCNT) Composition on Polyfluorene‐Based SWCNT Dispersion Selectivity
Authors: Liang Shuai , Li Han , Flavel Benjamin S. , Adronov Alex 
Published: May 2018

AbstractApplications of single‐walled carbon nanotubes (SWCNTs) are hampered by the mixtures of metallic and semiconducting SWCNTs that are present in commercial samples. Separation of SWCNTs according to electronic type is therefore extremely important. Recently, the selective interaction between the conjugated polymer, poly(9,9‐di‐n‐dodecyl‐fluorenyl‐2,7‐diyl) and semiconducting SWCNTs has been reported. However, the mechanism responsible for this selectivity is poorly understood. To determine whether this polymer is only selective for semiconducting SWCNTs, we exposed it to mixtures of metallic and semiconducting SWCNTs in different ratios. We found that the polymer is indeed selective for semiconducting SWCNTs in toluene, but only when the starting ratio is below 67:33 metallic:semiconducting. When the starting ratio is increased to 67:33 or higher, the amount of metallic SWCNTs dispersed dramatically increases. If the solvent is changed to THF, the threshold ratio at which metallic SWCNTs begin to be dispersed is much lower. This indicates that the polymer exhibits a preference for interaction with semiconducting SWCNTs, but is not precluded from interaction with metallic SWCNTs if exposed to a high enough concentration.
Molecular Manipulations of a Utility Nitrogen–Heterocyclic Carbene by Sodium Magnesiate Complexes and Transmetallation Chemistry with Gold Complexes
Authors: Hernán‐Gómez Alberto , Uzelac Marina , Baillie Sharon E. , Armstrong David R. , Kennedy Alan R. , Fuentes M. Ángeles , Hevia Eva 
Published: May 2018

AbstractExpanding the scope and applications of anionic N‐heterocyclic carbenes (NHCs), a novel series of magnesium NHC complexes is reported using a mixed sodium–magnesium approach. Sequential reactivity of classical imidazol‐ 2‐ylidene carbene IPr with NaR and MgR2 (R=CH2SiMe3) affords [(THF)3Na(μ‐IPr−)MgR2(THF)] (2) [IPr−=:C{[N(2,6‐iPr2C6H3)]2CHC] containing an anionic NHC ligand, whereas surprisingly sodium magnesiate [NaMgR3] fails to deprotonate IPr affording instead the redistribution coordination adduct [IPr2Na2MgR4] (1). Compound 2 undergoes selective C2‐methylation when treated with MeOTf furnishing novel abnormal NHC complex [{aIPrMeMgR2}2] (3). Dissolving 3 in THF led to the dissociation of this complex into MgR2 and aIPrMe with the latter isomerizing to the olefinic NHC IPr=CH2. The ability of 2 and 3 to transfer their anionic and abnormal NHC ligands, respectively to AuI metal fragments has been investigated allowing the isolation and structural characterization of [RAu(μ‐IPr−)MgR(THF)2] (4) and [aIPrMeAuR] (5) respectively. In both cases transfer of an alkyl R group is observed. However while 3 can also transfer its abnormal NHC ligand to give 5, in 4 the anionic NHC still remains coordinated to Mg via its C4 position, whereas the {AuR} fragment occupies the C2 position previously filled by a donor‐solvated {Na(THF)3}+ cation.
Synthetic and Mechanistic Investigation of an Oxime Ether Electrocyclization Approach to Heteroaromatic Boronic Acid Derivatives
Authors: Mora‐Radó Helena , Sotorríos Lia , Ball‐Jones Matthew P. , Bialy Laurent , Czechtizky Werngard , Méndez María , Gómez‐Bengoa Enrique , Harrity Joseph P. A. 
Published: May 2018

AbstractA range of functionalized heteroaromatic boronic acid derivatives are readily accessed by a diboration/6π‐electrocyclization sequence. This study revealed the surprising observation that there is a direct relationship between oxime ether stereochemistry and reactivity towards electrocyclization. Specifically, E‐oxime ethers are found to be significantly more reactive than their Z‐counterparts (stereochemistry relative to azatriene scaffold). In contrast, the configuration at the azatriene alkene terminus has little impact on reaction rates. Computational analysis offers a rationale for this observation; a Nlone pair→C=C π* orbital interaction lowers the energy of the transition state in the electrocyclization of E‐oxime ethers. Finally, unreactive Z‐oxime ethers can be converted to the corresponding heterocyclic products by a photolytically promoted E→Z isomerization and electrocyclization sequence.
DMSO as a Switchable Alkylating Agent in Heteroarene C−H Functionalization
Authors: Garza‐Sanchez R. Aleyda , Patra Tuhin , Tlahuext‐Aca Adrian , Strieth‐Kalthoff Felix , Glorius Frank 
Published: May 2018

AbstractHerein, we report a novel strategy for the activation of DMSO to act as a versatile alkylating agent in heteroarene C−H functionalization. This direct, simple, and mild switch between methylation/trideuteromethylation and methylthiomethylation of heteroarenes was achieved under reagent‐controlled photoredox catalysis conditions. The proposed mechanism is supported by both experimental and computational studies.
Aerobic Conditions Enhance the Photocatalytic Stability of CdS/CdOx Quantum Dots
Authors: Wakerley David W. , Ly Khoa H. , Kornienko Nikolay , Orchard Katherine L. , Kuehnel Moritz F. , Reisner Erwin 
Published: May 2018

AbstractPhotocatalytic H2 production through water splitting represents an attractive route to generate a renewable fuel. These systems are typically limited to anaerobic conditions due to the inhibiting effects of O2. Here, we report that sacrificial H2 evolution with CdS quantum dots does not necessarily suffer from O2 inhibition and can even be stabilised under aerobic conditions. The introduction of O2 prevents a key inactivation pathway of CdS (over‐accumulation of metallic Cd and particle agglomeration) and thereby affords particles with higher stability. These findings represent a possibility to exploit the O2 reduction reaction to inhibit deactivation, rather than catalysis, offering a strategy to stabilise photocatalysts that suffer from similar degradation reactions.