bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temporal solar radiation change at high elevations in Hawai‘i
Authors: Longman Ryan J. , Giambelluca Thomas W. , Alliss Randall J. , Barnes Mallory L. 
Published: May 2014

AbstractTrends in downwelling global solar irradiance were evaluated at high‐elevation sites on the island of Maui, Hawai‘i. Departures from monthly means were assessed for the 6 month Hawaiian wet and dry seasons over the period 1988 to 2012. Linear regression analysis was used to characterize trends in each season. For the dry season (May–October), statistically significant (p ≤ 0.05) positive trends of 9–18 W m−2 (3–6%) per decade were found at all four high‐elevation stations tested. Wet season trends were not significant, except at the highest‐elevation station, which had a significant negative trend. No consistent trends in aerosol concentrations have been observed at high elevations in Hawai‘i; therefore, the observed dry season brightening is most likely the result of decreasing cloud cover. Supporting this hypothesis, analysis of 15 years (1997–2012) of high temporal resolution Geostationary Operational Environmental Satellite (GOES) imagery over the Hawaiian Islands showed a statistically significant decrease in leeward cloud cover amounting to 5–11% per decade over the stations. In addition, analysis of Moderate Resolution Imaging Spectroradiometer data were in general agreement with the GOES trends, although statistically significant dry season trends were found at only one of the four stations.
Two‐dimensional/three‐dimensional waveform modeling of subducting slab and transition zone beneath Northeast Asia
Authors: Wang Tao , Revenaugh Justin , Song Xiaodong 
Published: May 2014

AbstractSubduction plays a fundamental role in dynamics of the mantle convection and in material circulations of the Earth's interior. Slabs have been imaged to subduct near horizontally in the transition zone (TZ) beneath the Northeast Asia in seismic tomography. Triplication waveform modeling is an effective tool to study the detailed seismic structure in the TZ. However, TZ triplication modeling has traditionally relied on 1‐D models. In this study, we use the spectral element method to explore influences of 2‐D/3‐D slab structure on TZ triplication waveforms and to model, for the first time, the slab and TZ structures beneath the Northeast Asia. Synthetic tests suggest that, for a subduction zone earthquake, slab structure can have important influences on TZ triplication waveforms and that, even in a narrow azimuth range, the effects from 2‐D/3‐D slab structure on the wave propagation can lead to erroneous conclusions with 1‐D modeling. Our data are high‐quality triplicated SH waveforms (at distances of 10°–32°) from a deep event (below 410 km discontinuity) in the Pacific subducting slab. Our 2‐D/3‐D waveform modeling results suggest that a simple model of the subducting slab (+5% high‐velocity anomaly and ~100 km thick down to 560 km) but normal below 560 km can match most of the observed waveforms remarkably well. The bottom of the TZ of the sampling region (north of the Yellow Sea) contains a patch of very slow anomaly. The results indicate that subhorizontal slab above the 660 discontinuity is not everywhere beneath Northeast Asia and the subducting slab is not everywhere continuous to the bottom of the TZ. Compared with the traditional 1‐D modeling, our new 2‐D/3‐D approach provides better fits to the data and allows us to constrain the slab geometry and to separate TZ structure from slab structure
Synthesis of the Tetrahydropyran Fragment of Bistramide D
Authors: Bates Roderick W. , Li Lu , Palani Kalpana , Phetsang Wanida , Loh Joanna Kejun 
Published: May 2014

AbstractA synthesis of the tetrahydropyran (THP) moiety of bistramide D has been completed by using cross‐metathesis and kinetically controlled intramolecular oxa‐Michael addition to form the ring with excellent trans selectivity. The C9 methyl substituent was introduced by using an unsaturated sulfone building block, which can be most effectively prepared through a combination of diastereoselective allylation and alkene isomerisation. The effect of this methyl group on subsequent cross‐metathesis reactions can be mitigated by careful choice of reaction conditions.
Brief communication: Cineradiographic analysis of the chimpanzee (Pan troglodytes) talonavicular and calcaneocuboid joints
Authors: Thompson Nathan E. , Holowka Nicholas B. , O'Neill Matthew C. , Larson Susan G. 
Published: May 2014

ABSTRACTDuring terrestrial locomotion, chimpanzees exhibit dorsiflexion of the midfoot between midstance and toe‐off of stance phase, a phenomenon that has been called the “midtarsal break.” This motion is generally absent during human bipedalism, and in chimpanzees is associated with more mobile foot joints than in humans. However, the contribution of individual foot joints to overall foot mobility in chimpanzees is poorly understood, particularly on the medial side of the foot. The talonavicular (TN) and calcaneocuboid (CC) joints have both been suggested to contribute significantly to midfoot mobility and to the midtarsal break in chimpanzees. To evaluate the relative magnitude of motion that can occur at these joints, we tracked skeletal motion of the hindfoot and midfoot during passive plantarflexion and dorsiflexion manipulations using cineradiography. The sagittal plane range of motion was 38 ± 10° at the TN joint and 14 ± 8° at the CC joint. This finding indicates that the TN joint is more mobile than the CC joint during ankle plantarflexion–dorsiflexion. We suggest that the larger range of motion at the TN joint during dorsiflexion is associated with a rotation (inversion–eversion) across the transverse tarsal joint, which may occur in addition to sagittal plane motion. Am J Phys Anthropol 154:604–608, 2014. © 2014 Wiley Periodicals, Inc.
Brief Communication: An enigmatic enamel alteration on the anterior maxillary teeth in a prehistoric North Italian population
Authors: Dori Irene , Moggi‐Cecchi Jacopo 
Published: May 2014

ABSTRACTIn this paper we describe a hitherto undocumented modification of the dental enamel surface observed in an Early Bronze Age population from northern Italy. The defect, which can be described as a curvilinear groove, is located on the lingual surface of incisors and canines in the upper jaw. This groove, documented both in the permanent and deciduous dentition, is located at approximately 1 mm from the cervix and extends from the mesiolingual to the distolingual surface. The occurrence of the groove is not related to the sex of the affected individuals, but its degree of expression is related to age at death. Because of its morphology, the groove cannot be considered as a result of disruptions in the process of enamel deposition. At the present stage of research we suggest that the groove might have been the result of some kind of dental erosion caused by as yet unidentified chemical factors. Am J Phys Anthropol 154:609–614, 2014. © 2014 Wiley Periodicals, Inc.
Serine‐Selective Aerobic Cleavage of Peptides and a Protein Using a Water‐Soluble Copper–Organoradical Conjugate
Authors: Seki Yohei , Tanabe Kana , Sasaki Daisuke , Sohma Youhei , Oisaki Kounosuke , Kanai Motomu 
Published: May 2014

AbstractThe site‐specific cleavage of peptide bonds is an important chemical modification of biologically relevant macromolecules. The reaction is not only used for routine structural determination of peptides, but is also a potential artificial modulator of protein function. Realizing the substrate scope beyond the conventional chemical or enzymatic cleavage of peptide bonds is, however, a formidable challenge. Here we report a serine‐selective peptide‐cleavage protocol that proceeds at room temperature and near neutral pH value, through mild aerobic oxidation promoted by a water‐soluble copper–organoradical conjugate. The method is applicable to the site‐selective cleavage of polypeptides that possess various functional groups. Peptides comprising D‐amino acids or sensitive disulfide pairs are competent substrates. The system is extendable to the site‐selective cleavage of a native protein, ubiquitin, which comprises more than 70 amino acid residues.
Reversible Redox Reaction Between Antiaromatic and Aromatic States of 32π‐Expanded Isophlorins
Authors: Gopalakrishna Tullimilli Y. , Anand Venkataramanarao G. 
Published: May 2014

Abstract32π‐antiaromatic expanded isophlorins with a varying number of thiophene and furan rings adopt either planar, ring‐inverted, or twisted conformations depending on the number of furan rings in the macrocycle. However, they exhibit identical reactivity with respect to their oxidation to aromatic 30π‐dicationic species under acidic conditions. These 32π‐antiaromatic macrocycles can also be oxidized with [Et3O+SbCl6−]and NOBF4 to generate dications, thus confirming ring oxidation of macrocycles. Furthermore, they can be reduced back to their parent 32π‐antiaromatic state by triethylamine, Zn, or FeCl2. Single‐crystal X‐ray diffraction analysis confirmed a figure‐eight conformation for a hexafuran system, which opens to a planar structure upon oxidation.
Synthesis of Poly(ethylene oxide) Approaching Monodispersity
Authors: Maranski Krzysztof , Andreev Yuri G. , Bruce Peter G. 
Published: May 2014

AbstractPolydispersity in polymers hinders fundamental understanding of their structure–property relationships and prevents them from being used in fields like medicine, where polydispersity affects biological activity. The polydispersity of relatively short‐chain poly(ethylene oxide) [(CH2CH2O2)n; PEO] affects its biological activity, for example, the toxicity and efficacy of PEOylated drugs. As a result, there have been intensive efforts to reduce the dispersity as much as possible (truly monodispersed materials are not possible). Here we report a synthetic procedure that leads to an unprecedented low level of dispersity. We also show for the first time that it is possible to discriminate between PEOs differing in only 1 ethylene oxide (EO) unit, essential in order to verify the exceptionally low levels of dispersity achieved here. It is anticipated that the synthesis of poly(ethylene oxide) approaching monodispersity will be of value in many fields where the applications are sensitive to the distribution of molar mass.
Monitoring Endocytic Trafficking of Anthrax Lethal Factor by Precise and Quantitative Protein Labeling
Authors: Zheng Siqi , Zhang Gong , Li Jie , Chen Peng R. 
Published: May 2014

AbstractCoupling the genetic code expansion technique with bioorthogonal reactions enables precise control over the conjugation site as well as the choice of fluorescent probes during protein labeling. However, the advantages of this strategy over bulky and rigid fluorescent proteins (FPs) remain to be fully explored. Here we applied site‐specific bioorthogonal labeling on anthrax lethal factor (LF) to visualize its membrane translocation inside live cells. In contrast to the previously reported FP tags that significantly perturbed LF’s membrane trafficking, our precisely and quantitatively labeled LF exhibited an endocytic activity comparable to wild‐type LF. This allowed time‐lapse imaging of LF’s natural translocation process from host cell membrane to cytosol, which revealed molecular details of its virulence mechanism. Our strategy is generally applicable for monitoring intracellular protein membrane translocation that is difficult to access using conventional protein labeling methodologies.
Tuning the Composition of AuPt Bimetallic Nanoparticles for Antibacterial Application
Authors: Zhao Yuyun , Ye Chunjie , Liu Wenwen , Chen Rong , Jiang Xingyu 
Published: May 2014

AbstractWe show that bimetallic nanoparticles (NPs) of AuPt without any surface modification are potent antibiotic reagents, while pure Au NPs or pure Pt NPs display no antibiotic activities. The most potent antibacterial AuPt NPs happen to be the most effective catalysts for chemical transformations. The mechanism of antibiotic action includes the dissipation of membrane potential and the elevation of adenosine triphosphate (ATP) levels. These bimetallic NPs are unique in that they do not produce reactive oxygen species as most antibiotics do. Being non‐toxic to human cells, these bimetallic noble NPs might open an entry to a new class of antibiotics.
Discovery of Clostrubin, an Exceptional Polyphenolic Polyketide Antibiotic from a Strictly Anaerobic Bacterium
Authors: Pidot Sacha , Ishida Keishi , Cyrulies Michael , Hertweck Christian 
Published: May 2014

AbstractGenome mining of the strictly anaerobic bacterium Clostridium beijerinckii, an industrial producer of solvents, revealed the presence of several cryptic gene clusters for secondary metabolite biosynthesis. To unearth its metabolic potential, a C. beijerinckii strain was cultured under various conditions, which led to the discovery of a deep purple pigment. This novel metabolite, named clostrubin (1), was isolated and its structure was fully elucidated. The pentacyclic polyphenol features a benzo[a]tetraphene ring topology that is unprecedented for natural products. Stable‐isotope labeling experiments showed that 1 is an aromatic polyketide that folds in a noncanonical manner to form the unusual perifused ring system. In addition to being the first reported polyketide from an anaerobic bacterium, 1 is a potent antibiotic with pronounced activity against various pathogenic bacteria, such as MRSA, VRE, and mycobacteria, with minimum inhibitory concentrations (MIC) of 0.12–0.97 μM.
Design and Synthesis of Copper–Cobalt Catalysts for the Selective Conversion of Synthesis Gas to Ethanol and Higher Alcohols
Authors: Prieto Gonzalo , Beijer Steven , Smith Miranda L. , He Ming , Au Yuen , Wang Zi , Bruce David A. , de Jong Krijn P. , Spivey James J. , de Jongh Petra E. 
Published: May 2014

AbstractCombining quantum‐mechanical simulations and synthesis tools allows the design of highly efficient CuCo/MoOx catalysts for the selective conversion of synthesis gas (CO+H2) into ethanol and higher alcohols, which are of eminent interest for the production of platform chemicals from non‐petroleum feedstocks. Density functional theory calculations coupled to microkinetic models identify mixed Cu–Co alloy sites, at Co‐enriched surfaces, as ideal for the selective production of long‐chain alcohols. Accordingly, a versatile synthesis route is developed based on metal nanoparticle exsolution from a molybdate precursor compound whose crystalline structure isomorphically accommodates Cu2+ and Co2+ cations in a wide range of compositions. As revealed by energy‐dispersive X‐ray nanospectroscopy and temperature‐resolved X‐ray diffraction, superior mixing of Cu and Co species promotes formation of CuCo alloy nanocrystals after activation, leading to two orders of magnitude higher yield to high alcohols than a benchmark CuCoCr catalyst. Substantiating simulations, the yield to high alcohols is maximized in parallel to the CuCo alloy contribution, for Co‐rich surface compositions, for which Cu phase segregation is prevented.
Multiple Phases of Molybdenum Carbide as Electrocatalysts for the Hydrogen Evolution Reaction
Authors: Wan Cheng , Regmi Yagya N. , Leonard Brian M. 
Published: May 2014

AbstractMolybdenum carbide has been proposed as a possible alternative to platinum for catalyzing the hydrogen evolution reaction (HER). Previous studies were limited to only one phase, β‐Mo2C with an Fe2N structure. Here, four phases of Mo‐C were synthesized and investigated for their electrocatalytic activity and stability for HER in acidic solution. All four phases were synthesized from a unique amine–metal oxide composite material including γ‐MoC with a WC type structure which was stabilized for the first time as a phase pure nanomaterial. X‐ray photoelectron spectroscopy (XPS) and valence band studies were also used for the first time on γ‐MoC. γ‐MoC exhibits the second highest HER activity among all four phases of molybdenum carbide, and is exceedingly stable in acidic solution.
Dramatic Increase in the Oxygen Reduction Reaction for Platinum Cathodes from Tuning the Solvent Dielectric Constant
Authors: Fortunelli Alessandro , Goddard William A. , Sha Yao , Yu Ted H. , Sementa Luca , Barcaro Giovanni , Andreussi Oliviero 
Published: May 2014

AbstractHydrogen fuel cells (FC) are considered essential for a sustainable economy based on carbon‐free energy sources, but a major impediment are the costs. First‐principles quantum mechanics (density functional theory including solvation) is used to predict how the energies and barriers for the mechanistic steps of the oxygen reduction reaction (ORR) over the fcc(111) platinum surface depend on the dielectric constant of the solvent. The ORR kinetics can be strongly accelerated by decreasing the effective medium polarizability from the high value it has in water. Possible ways to realize this experimentally are suggested. The calculated volcano structure for the dependence of rate on solvent polarization is considered to be general, and should be observed in other electrochemical systems.
Screw‐Dislocation‐Driven Bidirectional Spiral Growth of Bi2Se3 Nanoplates
Authors: Zhuang Awei , Li Jia‐Jun , Wang You‐Cheng , Wen Xin , Lin Yue , Xiang Bin , Wang Xiaoping , Zeng Jie 
Published: May 2014

AbstractBi2Se3 attracts intensive attention as a typical thermoelectric material and a promising topological insulator material. However, previously reported Bi2Se3 nanostructures are limited to nanoribbons and smooth nanoplates. Herein, we report the synthesis of spiral Bi2Se3 nanoplates and their screw‐dislocation‐driven (SDD) bidirectional growth process. Typical products showed a bipyramid‐like shape with two sets of centrosymmetric helical fringes on the top and bottom faces. Other evidence for the unique structure and growth mode include herringbone contours, spiral arms, and hollow cores. Through the manipulation of kinetic factors, including the precursor concentration, the pH value, and the amount of reductant, we were able to tune the supersaturation in the regime of SDD to layer‐by‐layer growth. Nanoplates with preliminary dislocations were discovered in samples with an appropriate supersaturation value and employed for investigation of the SDD growth process.
Effect of physical and chemical crosslinking structure on fatigue behavior of styrene butadiene elastomer
Authors: Liu Yuxin , Chen Jian , Li Guangxian , Liu Xiaolin , Liao Xia , Yang Qi 
Published: May 2014

ABSTRACTThe fatigue behavior of two styrene butadiene rubbers, thermoplastic elastomer (SBS) with physical crosslinking structure and vulcanized styrene butadiene rubber (SBR) with chemical crosslinking structure, was investigated. The fatigue lives of SBS and SBR were greatly affected by the fatigue frequency, amplitude, and temperature. The fatigue lives of both SBS and SBR decreased with the increasing fatigue frequency and amplitude. However, the effect of fatigue temperature on the fatigue life of SBS was different from that of SBR. With the increasing fatigue temperature, the fatigue life of SBS first decreased and then increased, however, the fatigue life of SBR showed continuous decreasing trend. The tensile strength of SBS first increased and then decreased with the increase of fatigue time, but the tensile strength of SBR was not significantly influenced by the fatigue time. The fatigue amplitude had greater effect on the tensile strength of SBS than that of SBR. The permanent deformation of both SBS and SBR increased with temperature; however, the parameter for the former rubber was higher than that of the latter. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40917.
From the Perceiving Soma to the Phantasized Body
Authors: Joannidis Christo 
Published: May 2014

AbstractThis article attempts to convey a psychoanalytic understanding of the movement from a body‐state where the perceptive – biological – reflex reactions are paramount to a body‐state where this is intertwined with the emerging presence of psychic representations and the mentalization processes. The central position of sexuality and gender identification in all this, is highlighted. Through the use of two clinical vignettes, a putative link is attempted between early infantile experiences and psychic constitutions in adult life. Finally the influence of environmental/societal factors on the shaping of individual sexuality is emphasized. Copyright © 2014 John Wiley & Sons, Ltd.
Estimation of bus dwell time using univariate time series models
Authors: Rashidi Soroush , Ranjitkar Prakash 
Published: May 2014

SummaryA significant proportion of bus travel time is contributed by dwell time for passenger boarding and alighting. More accurate estimation of bus dwell time (BDT) can enhance efficiency and reliability of public transportation system. Regression and probabilistic models are commonly used in literatures where a set of independent variables are used to define the statistical relationship between BDT and its contributing factors. However, due to technical and monetary constraints, it is not always feasible to collect all the data required for the models to work. More importantly, the contributing factors may vary from one bus route to another. Time series based methods can be of great interest as they require only historical time series data, which can be collected using a facility known as automatic vehicle location (AVL) system. This paper assesses four different time series based methods namely random walk, exponential smoothing, moving average (MA), and autoregressive integrated moving average to model and estimate BDT based on AVL data collected from Auckland. The performances of the proposed methods are ranked based on three important factors namely prediction accuracy, simplicity, and robustness. The models showed promising results and performed differently for central business district (CBD) and non‐CBD bus stops. For CBD bus stops, MA model performed the best, whereas for non‐CBD bus stops, ARIMA model performed the best compared with other time series based models. Copyright © 2014 John Wiley & Sons, Ltd.
Tenascin‐C is increased in atherothrombotic stroke patients and has an anti‐inflammatory effect in the human carotid artery
Authors: Clancy Paula , Lincz Lisa F. , Maguire Jane , McEvoy Mark , Koblar Simon A. , Golledge Jonathan 
Published: May 2014

AbstractTenascin‐C (Tn‐C) is an endogenous ligand of toll‐like receptor‐4 (TLR‐4); a key signalling molecule associated with chronic inflammatory conditions. Both Tn‐C and TLR‐4 are increased in unstable human atheroma, but their effects on local inflammatory conditions have not been investigated. The aim of the present study was to investigate the association and functional implications of Tn‐C/TLR‐4 signalling in large artery atherosclerotic stroke. Plasma Tn‐C was measured by ELISA and found to be higher in recent stroke patients (n = 336; median 12.77 µg/mL, inter‐quartile range 10.23–15.74 µg/mL) than in controls (n = 321; median 11.31 µg/mL, inter‐quartile range 8.89–13.90 µg/mL), P < 0.001. Plasma Tn‐C was also independently positively associated with stroke (odds ratio for highest Tn‐C quartile 2.27, 95% confidence interval 1.37–3.76). Assessment of Tn‐C associated chronic cytokine secretion was performed in vitro using paired, human, macroscopically disease matched, carotid atheroma tissue biopsies obtained from five patients undergoing carotid endarterectomy. A 4‐day incubation with specific Tn‐C blocking antibodies (Abs) increased secretion of TLR‐4‐associated cytokines, interleukin (IL)‐8, IL‐1β, tumour necrosis factor and C‐C motif chemokine (CCL)3 and expression of TLR‐4 in the tissue. These results suggest with Tn‐C blockade another endogenous TLR‐4 ligand upregulates TLR‐4 expression and subsequent cytokine secretion. Titration of the Tn‐C Abs also dose dependently increased secretion of IL‐6, IL‐8, IL‐1β, and CCL3 in mixed, healthy, primary vascular cell culture. In summary, circulating concentrations of Tn‐C are higher in patients with a recent history of atherosclerotic stroke and may play an anti‐inflammatory role by reducing pro‐inflammatory cytokine release from atheroma. © 2014 BioFactors, 40(4):448–457, 2014