bluuebunny/crossref_metadata_2025 huggingface dataset:
Scale dependence of Hortonian rainfall‐runoff processes in a semiarid environment
Authors: Chen L. , Sela S. , Svoray T. , Assouline S.
Published: June 2016

Scale dependence of Hortonian rainfall‐runoff processes has received much attention in the literature but has not been fully resolved. To further explore this issue, a recently developed model was applied to simulate rainfall‐infiltration‐runoff processes at multiple spatial scales. The model consists of the coupling between a two‐dimensional runoff routing module and a two‐layer infiltration module, thus accounting for spatial variability in soil properties, soil surface sealing, topography, and partial vegetation cover. A 76 m2 semiarid experimental plot with sparse cover of vegetation patches and a sealed soil surface in inter‐patch bare areas was used as a representative elementary area (REA). A series of four larger artificial plots of different areas was created based on this REA to examine the scale dependence of rainfall‐runoff relationships in the case of stationary heterogeneity. Results show that runoff depth (or runoff coefficient) decreases with increasing scale. This trend is more prominent at scales less than 10 times the REA length. Power law relationships can quantitatively describe the scaling law. The major mechanism of the scale effect is run‐on infiltration. However, rainfall intensity and soil properties can both affect the scaling trend through their interaction with run‐on. Higher intensity and less temporal variability of rainfall can both reduce the scale effect. Temporally intermittent rainfall may produce spatially oscillating infiltration rates at large scales. Vegetation patterns are another factor that may affect the scaling. Random‐vegetation patterns, compared with regular patterns with similar statistical properties, change the spatial distributions, but do not significantly change either the total amount and statistical properties of infiltration and runoff or the scale dependence of the rainfall‐runoff process.
Role of meteorological controls on interannual variations in wet‐period characteristics of wetlands
Authors: Liu Yanlan , Kumar Mukesh
Published: June 2016

Many ecological functions of wetlands are influenced by wet‐periods, i.e., the time interval when groundwater table (GWT) is continuously near the land surface. Hence, there is a crucial need to understand the controls on interannual variations of wet‐periods. Given the scarcity of long‐term measurements of GWT in wetlands, understanding variations in wet‐periods using a measurement approach alone is challenging. Here we used a physically based, fully distributed hydrologic model, in synergy with publicly available hydrologic data, to simulate long‐term wet‐period variations in 10 inland forested wetlands in a southeastern US watershed. A Bayesian regression and variable selection framework was then implemented to (a) evaluate the extent to which the simulated wet‐periods can be estimated and predicted by precipitation (Ppt) and potential evapotranspiration (PET) and (b) infer the relative roles of seasonal Ppt and PET. Our results indicate that wet‐period start date and duration could vary by more than 6 months during the 32 year simulation period. Remarkably, 60–90% of these variations could be captured using regressions based on seasonal Ppt and PET in most wetlands. Effects of seasonal meteorological conditions on wet‐period variations were found to be nonuniform, which indicate that the annual variables may not explain interannual variations in wet‐periods. The Bayesian framework was able to predict wet‐period variations with errors smaller than 1 month at a 90% confidence level. The presented framework provides a minimalistic approach for estimating and predicting wet‐period variations in wetlands and may be used to understand the future responses of associated ecological functions in wetlands.
Relevance of dissolved organic nutrients for the Arctic Ocean nutrient budget
Authors: Torres‐Valdés Sinhué , Tsubouchi Takamasa , Davey Emily , Yashayaev Igor , Bacon Sheldon
Published: June 2016

We ask whether dissolved organic nitrogen (DON) and phosphorus (DOP) could account for previously identified Arctic Ocean (AO) inorganic nutrient budget imbalances. We assess transports to/from the AO by calculating indicative budgets. Marked DON:DOP ratio differences between the Amerasian and Eurasian AO reflect different physical and biogeochemical pathways. DON and DOP are exported to the North Atlantic via Davis Strait potentially being enhanced in transit from Bering Strait. Fram Strait transports are balanced. Barents Sea Opening transports may provide an additional nutrient source to the Barents Sea or may be locked within the wider AO Atlantic Water circulation. Gaps in our knowledge are identified and discussed.
The plasma structure of coronal hole solar wind: Origins and evolution
Authors: Borovsky Joseph E.
Published: June 2016

Whereas slow solar wind is known to be highly structured, the fast (coronal hole origin) wind is usually considered to be homogeneous. Using measurements from Helios 1 + 2, ACE, Wind, and Ulysses, structure in the coronal hole origin solar wind is examined from 0.3 AU to 2.3 AU. Care is taken to collect and analyze intervals of “unperturbed coronal hole plasma.” In these intervals, solar wind structure is seen in the proton number density, proton temperature, proton specific entropy, magnetic field strength, magnetic field to density ratio, electron heat flux, helium abundance, heavy‐ion charge‐state ratios, and Alfvenicity. Typical structure amplitudes are factors of 2, far from homogeneous. Variations are also seen in the solar wind radial velocity. Using estimates of the motion of the solar wind origin footpoint on the Sun for the various spacecraft, the satellite time series measurements are converted to distance along the photosphere. Typical variation scale lengths for the solar wind structure are several variations per supergranule. The structure amplitude and structure scale sizes do not evolve with distance from the Sun from 0.3 to 2.3 AU. An argument is quantified that these variations are the scale expected for solar wind production in open magnetic flux funnels in coronal holes. Additionally, a population of magnetic field foldings (switchbacks, reversals) in the coronal hole plasma is examined: this population evolves with distance from the Sun such that the magnetic field is mostly Parker spiral aligned at 0.3 AU and becomes more misaligned with distance outward.
Sensitivity of volcanic aerosol dispersion to meteorological conditions: A Pinatubo case study
Authors: Jones Anthony C. , Haywood James M. , Jones Andy , Aquila Valentina
Published: June 2016

Using a global climate model (Hadley Centre Global Environment Model version 2‐Carbon Cycle Stratosphere ) with a well‐resolved stratosphere, we test the sensitivity of volcanic aerosol plume dispersion to meteorological conditions by simulating 1 day Mount Pinatubo‐like eruptions on 10 consecutive days. The dispersion of the volcanic aerosol is found to be highly sensitive to the ambient meteorology for low‐altitude eruptions (16–18 km), with this variability related to anomalous anticyclonic activity along the subtropical jet, which affects the permeability of the tropical pipe and controls the amount of aerosol that is retained by the tropical reservoir. Conversely, a high‐altitude eruption scenario (19–29 km) exhibits low meteorological variability. Overcoming day‐to‐day meteorological variability by spreading the emission over 10 days is shown to produce insufficient radiative heating to loft the aerosol into the stratospheric tropical aerosol reservoir for the low eruption scenario. This results in limited penetration of aerosol into the southern hemisphere (SH) in contrast to the SH transport observed after the Pinatubo eruption. Our results have direct implications for the accurate simulation of past/future volcanic eruptions and volcanically forced climate changes, such as Intertropical Convergence Zone displacement.
The Predictive Utility of a Working Memory Span Task Depends on Processing Demand and the Cognitive Task
Authors: Kanerva Kaisa , Kalakoski Virpi
Published: June 2016

The relationship between performance in working memory (WM) span tasks, scholastic skills and fluid intelligence was investigated to determine how WM span is related to higher order cognition. The predictive utility of two WM span tasks differing in the demand of the processing task was studied with controlled presentation times and a broad set of academic criterion tasks. Sixty‐eight adolescents (mean age 16 years) completed two WM span tasks, Raven's Progressive Matrices and several scholastic performance measures. The results showed that the more demanding WM span task predicted fluid intelligence, but did not contribute uniquely in explaining scholastic performance. In contrast, the less demanding WM task predicted scholastic performance. The results suggest that the strength of the relation between WM performance and higher order cognition varies in conjunction with both the demand of the WM span task and the type of higher order cognition measure.Copyright © 2016 John Wiley & Sons, Ltd.
Ultrafast Assembly of PS‐PDMS Block Copolymers on 300 mm Wafers by Blending with Plasticizers
Authors: Arias‐Zapata Javier , Böhme Sophie , Garnier Jérôme , Girardot Cécile , Legrain Antoine , Zelsmann Marc
Published: June 2016

Next‐generation lithography techniques based on the self‐assembly of block copolymers (BCPs) are promising methods for high‐resolution pattering. BCPs with a high incompatibility (high‐χ), such as polystyrene‐polydimethylsiloxane (PS‐PDMS), show encouraging results in terms of resolution. In the strong segregation regime, the high diffusive energy barrier of PS‐PDMS excessively reduces the self‐assembly kinetics; this is why solvent–vapor annealing is typically adopted to shorten the self‐assembly time. Plasticizers are generally used to reduce the glass transition temperature (Tg) of polymers. In this study, commercial plasticizers such as dioctylsebacate and diisooctyl adipate are blended with PS‐PDMS polymers, and their influence on the self‐assembly process is investigated. The intrinsic PS selectivity of the plasticizers brings the BCP to form PS‐PDMS micelles, which results in highly ordered self‐assembled body‐centered cubic spherical PS‐PDMS after spin‐coating without any annealing. The negligible vapor pressure of plasticizers and the decrease ofTgallow the high mobility of PS‐PDMS micelles in thin films. A transition into a stable horizontal cylindrical morphology is then possible by ultrafast thermal annealing (30 s). The complete process, from the BCP deposition to the final pattern transfer into Si, is presented on 300 mm standard wafers, which makes this method promising for microelectronic industrial integration.
Catalytic Asymmetric Chlorinative Dearomatization Reaction of Benzofurans
Authors: Liang Xiao‐Wei , Zheng Chao , You Shu‐Li
Published: June 2016

A catalytic asymmetric chlorinative dearomatization reaction of benzofuran derivatives was achieved by using hydroquinidine 1,4‐phthalazinediyl diether [(DHQD)2PHAL] as the catalyst and N‐chlorophthalimide (NCP) as the chlorinating reagent. A series of chlorinated spiro[benzofuran‐2,5′‐oxazole]s bearing two contiguous stereogenic centers was obtained in high yields (up to 99%) with excellent enantioselectivity (up to 99% ee).

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Copper‐Catalyzed CNH2 Arylation of 2‐Aminobenzimidazoles and Related C‐Amino‐NH‐azoles
Authors: Rao Desaboini Nageswar , Rasheed Sk. , Kumar Karampoori Anil , Reddy Annem Siva , Das Parthasarathi
Published: June 2016

A copper(II)‐catalyzed selective CNH2 arylation of 2‐aminobenzimidazoles and related C‐amino‐NH‐azoles was achieved in presence of 2,2′‐bipyridine and cesium carbonate at 60 °C under open air conditions and this is first method for the copper‐catalyzed selective CNH2 arylation in the presence of other reactive nucleophilic sites. Previously unexplored heteroaromatics possessing multiple nucleophilic sites that are selectively arylated at the CNH2 position are obtained, providing an exceptional tool for rapid delivery of a diverse array of medicinally important CNH(aryl) derivatives of aminoazoles without any protection/deprotection of ring NH bonds. It is first example for the selective CNH2 arylation of 5‐aminoindazole, 4‐aminopyrazole, 5‐aminopyrazole, 9H‐purine‐6‐amine, and 1H‐pyrazolo[3,4‐d]pyrimidin‐4‐amine derivatives.

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Electron‐Poor, Fluoro‐Containing Arylboronic Acids as Efficient Coupling Partners for Bis(1,5‐cyclooctadiene)nickel(0)/Tricyclohexylphosphine‐Catalyzed Cross‐Coupling Reactions of Aryl Arenesulfonates
Authors: Chen Wen‐Bo , Xing Chun‐Hui , Dong Jie , Hu Qiao‐Sheng
Published: June 2016

The use of electron‐poor, fluoro‐containing arylboronic acids as general coupling partners for nickel(0)/tricyclohexylphosphine‐catalyzed cross‐coupling of aryl arenesulfonates is described. Electron‐poor fluoro‐containing arylboronic acids were found to react faster than electron‐rich/neutral arylboronic acids, with (4‐methoxyphenyl)(4‐methylbenzenesulfonato‐κO)bis(tricyclohexylphosphine)nickel. Bis(1,5‐cyclooctadiene)nickel(0)/tricyclohexylphosphine, (4‐methoxyphenyl)(4‐methylbenzenesulfonato‐κO)bis(tricyclohexylphosphine)nickel and bis(tricyclohexylphosphine)nickel(II) bromide were all found to be efficient catalysts/catalyst precursors.

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Vanadyl Acetylacetonate Catalyzed Methylenation of Imidazo[1,2‐a]pyridines by Using Dimethylacetamide as a Methylene Source: Direct Access to Bis(imidazo[1,2‐a]pyridin‐3‐yl)methanes
Authors: Kaswan Pinku , Nandwana Nitesh Kumar , DeBoef Brenton , Kumar Anil
Published: June 2016

An efficient protocol has been developed for the methylenation of imidazo[1,2‐a]pyridines using dimethylacetamide (DMA) as methylene source in the presence of vanadyl acetylacetonate [VO(acac)2] as the catalyst and iodobenzene diacetate as the oxidant. The reaction involves coupling of sp3‐ and sp2‐hybridized carbons and proceeds through the formation of an iminium ion. A wide variety of imidazo[1,2‐a]pyridines were converted to bis(imidazo[1,2‐a]pyridin‐3‐yl)methanes in good to excellent yields. A gram‐scale reaction demonstrated the potential for the scale‐up processes.

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The Reactivity of Difluorocarbene with Hydroxylamines: Synthesis of Carbamoyl Fluorides
Authors: Baars Hannah , Engel Julien , Mertens Lucas , Meister Daniela , Bolm Carsten
Published: June 2016

Carbamoyl fluorides are formed in reactions of hydroxylamines with difluorocarbene generated from sodium bromodifluoroacetate as readily available and non‐toxic carbene precursor. The process shows a high functional group tolerance, and the reaction path has been rationalized by computational calculations.

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Effect of Molecular Structure Parameters on Crystallinity and Environmental Stress Cracking Resistance of High‐Density Polyethylene/TiO2 Nanocomposites
Authors: Shirkavand Mohammad Javad , Azizi Hamed , Ghasemi Ismaeil , Karabi Mohammad
Published: June 2016

The correlation between molecular microstructure with crystallization behavior and environmental stress cracking resistance (ESCR) for three commercial grades of high‐density polyethylene and their nanocomposites has been investigated. Molecular architecture was characterized using high‐temperature gel permeation chromatography (GPC) test. Qualitative comparison of crystallinity and side chain branches of neat high‐density polyethylenes (HDPEs) has been performed using FTIR test and results were in good accordance with GPC results. Investigation of crystallinity and effect of side chain branches on the crystallite's dimensions has been carried out by DSC and XRD tests. Moreover, it was found that addition of nano‐TiO2 to HDPE causes an increase in crystal content and a decrease in crystal size, simultaneously. It was concluded from ESCR characterization that molecular weight and side chain branches are the most important structural parameters affecting ESCR properties of HDPE. The significance of side chain branches is higher compared to molecular weight.
Intracemetery biological variation at the fort ancient sunwatch village
Authors: Sciulli Paul W. , Cook Robert A.
Published: June 2016

Objectives

We investigate intracemetery biological variation at the Fort Ancient SunWatch village (800–500 BP.) to test the hypothesis that the SunWatch population consisted of spatially structured biologically differentiated kin groups consisting of distinct local Late Woodland and non‐local Mississippian biological populations.

Material and Methods

The SunWatch sample contains 166 individuals: 63 adults and 103 subadults. We analyze intracemetery biological variation using two feature sets: the buccolingual diameters of the polar teeth in the permanent (n = 37) and deciduous (n = 26) dentitions. We apply matrix correlation models to biodistance and grave distance matrices in both data sets, evaluate burial outliers and individuals exhibiting a rare dental feature with interindividual biological distances, and evaluate potential cultural subgroups with Mahalanobis' distance.

Results

Matrix correlation analyses for both feature sets as well as interindividual and subgroup distances indicate the SunWatch village cemetery was kin structured, contained a single primary biological population, and also contained a small number of non‐local individuals most of whom were from closely related populations. We thus reject the hypothesis that the SunWatch population consisted of biologically distinct Late Woodland and Mississippian biological populations.

Discussion

Although SunWatch village exhibited cultural attributes characteristic of both local Late Woodland and non‐local Mississippian groups, biologically the village was composed of one primary population. The lack of evidence for marked biological differentiation in the SunWatch village area at about 800–500 BP. suggests diffusion and acculturation may account for Mississippian cultural characteristics in southwestern Ohio Fort Ancient villages. If gene flow or migrations from biologically distinct Mississippian populations into southwestern Ohio occurred, either or both likely occurred well before 800 BP. This would have allowed the process of admixture time to produce a relatively homogeneous, nondifferentiated population. The latter alternative is consistent with the appearance in southwestern Ohio of non‐local individuals at one site linked to surrounding Mississippian regions at about 950 BP. Am J Phys Anthropol 160:719–728, 2016. © 2016 Wiley Periodicals, Inc.
Prospective, open‐label safety study of intravenous recombinant tissue plasminogen activator in wake‐up stroke
Authors: Barreto Andrew D. , Fanale Christopher V. , Alexandrov Andrei V. , Gaffney Kevin C. , Vahidy Farhaan S. , Nguyen Claude B. , Sarraj Amrou , Rahbar Mohammad , Grotta James C. , Savitz Sean I. ,   for the Wake‐Up Stroke Investigators
Published: June 2016

Objective

It is estimated that one of four ischemic strokes are noticed upon awakening and are not candidates for intravenous recombinant tissue plasminogen activator (rtPA) because their symptoms are >3 hours from last seen normal (LSN). We tested the safety of rtPA in a multicenter, single‐arm, prospective, open‐label study (NCT01183533) in patients with wake‐up stroke (WUS).

Methods

We aimed to enroll 40 WUS patients with disabling deficits. Patients were 18 to 80 years of age, National Institutes of Health Stroke Scale (NIHSS) ≤25, and selected only on the appearance of noncontrast computed tomography (ie, over one‐third middle cerebral artery territory hypodensity). Standard‐dose (0.9mg/kg) intravenous rtPA had to be started ≤3 hours of patient awakening. The primary safety outcome was symptomatic intracerebral hemorrhage (sICH) with preplanned stopping rules and data safety board oversight. Other endpoints included: asymptomatic intracerebral hemorrhage; clinical improvement in NIHSS; and 90‐day modified Rankin Scale (mRS) score.

Results

Between October 2010 and October 2013, all 40 preplanned patients were enrolled (50% men) at five stroke centers. Four patients (10%) were subsequently determined to be mimics. Patients had a mean age of 60.8, median NIHSS of 6.5 (range, 2–24), and received thrombolysis at a mean time of 10.3 ± 2.6 LSN and 2.6 ± 0.6 hours from awakening with deficits. No sICH or parenchymal hematomas occurred. At 3 months, 20 of 38 (52.6%) patients achieved excellent recovery with mRS scores of 0 or 1 (2 patients were lost to follow‐up).

Interpretation

Intravenous thrombolysis was safe in this prospective WUS study of patients selected by noncontrast CT. A randomized effectiveness trial appears feasible using a similar, pragmatic design. Ann Neurol 2016;80:211–218
Self‐Assembly of Measles Virus Nucleocapsid‐like Particles: Kinetics and RNA Sequence Dependence
Authors: Milles Sigrid , Jensen Malene Ringkjøbing , Communie Guillaume , Maurin Damien , Schoehn Guy , Ruigrok Rob W. H. , Blackledge Martin
Published: June 2016

Measles virus RNA genomes are packaged into helical nucleocapsids (NCs), comprising thousands of nucleo‐proteins (N) that bind the entire genome. N‐RNA provides the template for replication and transcription by the viral polymerase and is a promising target for viral inhibition. Elucidation of mechanisms regulating this process has been severely hampered by the inability to controllably assemble NCs. Here, we demonstrate self‐organization of N into NC‐like particles in vitro upon addition of RNA, providing a simple and versatile tool for investigating assembly. Real‐time NMR and fluorescence spectroscopy reveals biphasic assembly kinetics. Remarkably, assembly depends strongly on the RNA‐sequence, with the genomic 5′ end and poly‐Adenine sequences assembling efficiently, while sequences such as poly‐Uracil are incompetent for NC formation. This observation has important consequences for understanding the assembly process.
Formation of a Double Diamond Cubic Phase by Thermotropic Liquid Crystalline Self‐Assembly of Bundled Bolaamphiphiles
Authors: Zeng Xiangbing , Prehm Marko , Ungar Goran , Tschierske Carsten , Liu Feng
Published: June 2016

A quaternary amphiphile with swallow‐tail side groups displays a new bicontinuous thermotropic cubic phase with symmetry Pn
m and formed by two interpenetrating networks where cylindrical segments are linked by H bonds at tetrahedral junctions. Each network segment contains two bundles, each containing 12 rod‐like mesogens, lying along the segment axis. This assembly leads to the first thermotropic structure of the “double diamond” type. A quantitative geometric model is proposed to explain the occurrence of this rare phase.
Practical and Broadly Applicable Catalytic Enantioselective Additions of Allyl‐B(pin) Compounds to Ketones and α‐Ketoesters
Authors: Robbins Daniel W. , Lee KyungA , Silverio Daniel L. , Volkov Alexey , Torker Sebastian , Hoveyda Amir H.
Published: June 2016

A set of broadly applicable methods for efficient catalytic additions of easy‐to‐handle allyl‐B(pin) (pin=pinacolato) compounds to ketones and acyclic α‐ketoesters was developed. Accordingly, a large array of tertiary alcohols can be obtained in 60 to >98 % yield and up to 99:1 enantiomeric ratio. At the heart of this development is rational alteration of the structures of the small‐molecule aminophenol‐based catalysts. Notably, with ketones, increasing the size of a catalyst moiety (tBu to SiPh3) results in much higher enantioselectivity. With α‐ketoesters, on the other hand, not only does the opposite hold true, since Me substitution leads to substantially higher enantioselectivity, but the sense of the selectivity is reversed as well.
Cross‐Platform DNA Encoding for Single‐Cell Imaging of Gene Expression
Authors: Zrazhevskiy Pavel , Akilesh Shreeram , Tai Wanyi , Queitsch Konstantin , True Lawrence D. , Fromm Jonathan , Wu David , Nelson Peter , Stamatoyannopoulos John A. , Gao Xiaohu
Published: June 2016

Integration of imaging data across different molecular target types can provide in‐depth insight into cell physiology and pathology, but remains challenging owing to poor compatibility between target‐type‐specific labeling methods. We show that cross‐platform imaging analysis can be readily achieved through DNA encoding of molecular targets, which translates the molecular identity of various target types into a uniform in situ array of ssDNA tags for subsequent labeling with complementary imaging probes. The concept was demonstrated through multiplexed imaging of mRNAs and their corresponding proteins with multicolor quantum dots. The results reveal heterogeneity of cell transfection with siRNA and outline disparity in RNA interference (RNAi) kinetics at the level of both the mRNA and the encoded protein.
A Supramolecularly Activated Radical Cation for Accelerated Catalytic Oxidation
Authors: Jiao Yang , Li Wan‐Lu , Xu Jiang‐Fei , Wang Guangtong , Li Jun , Wang Zhiqiang , Zhang Xi
Published: June 2016

Tuning the activity of radicals is crucial for radical reactions and radical‐based materials. Herein, we report a supramolecular strategy to accelerate the Fenton reaction through the construction of supramolecularly activated radical cations. As a proof of the concept, cucurbit[7]uril (CB[7]) was introduced, through host–guest interactions, onto each side of a derivative of 1,4‐diketopyrrolo[3,4‐c]pyrrole (DPP), a model dye for Fenton oxidation. The DPP radical cation, the key intermediate in the oxidation process, was activated by the electrostatically negative carbonyl groups of CB[7]. The activation induced a drastic decrease in the apparent activation energy and greatly increased the reaction rate. This facile supramolecular strategy is a promising method for promoting radical reactions. It may also open up a new route for the catalytic oxidation of organic pollutants for water purification and widen the realm of supramolecular catalysis.
Oil‐Soluble Polymer Brush Grafted Nanoparticles as Effective Lubricant Additives for Friction and Wear Reduction
Authors: Wright Roger A. E. , Wang Kewei , Qu Jun , Zhao Bin
Published: June 2016

The development of high performance lubricants has been driven by increasingly growing industrial demands and environmental concerns. Herein, we demonstrate oil‐soluble polymer brush‐grafted inorganic nanoparticles (hairy NPs) as highly effective lubricant additives for friction and wear reduction. A series of oil‐miscible poly(lauryl methacrylate) brush‐grafted silica and titania NPs were synthesized by surface‐initiated atom transfer radical polymerization. These hairy NPs showed exceptional stability in poly(alphaolefin) (PAO) base oil; no change in transparency was observed after being kept at −20, 22, and 100 °C for ≥55 days. High‐contact stress ball‐on‐flat reciprocating sliding tribological tests at 100 °C showed that addition of 1 wt % of hairy NPs into PAO led to significant reductions in coefficient of friction (up to ≈40 %) and wear volume (up to ≈90 %). The excellent lubricating properties of hairy NPs were further elucidated by the characterization of the tribofilm formed on the flat. These hairy NPs represent a new type of lubricating oil additives with high efficiency in friction and wear reduction.
Selective tetrahydropyranylation of alcohols and phenols using titanium(IV) salophen trifluoromethanesulfonate as an efficient catalyst
Authors: Yadegari Maryam , Moghadam Majid
Published: June 2016

Titanium(IV) salophen trifluoromethanesulfonate, [TiIV(salophen)(OSO2CF3)2], as a catalyst enables selective tetrahydropyranylation of alcohols and phenols with 3,4‐dihydro‐2H‐pyran. Using this catalytic system, primary, secondary and tertiary alcohols, as well as phenols, were converted to their corresponding tetrahydropyranyl ethers in high yields and short reaction times at room temperature. Investigation of the chemoselectivity of this method showed discrimination between the activity of primary alcohols in the presence of secondary and tertiary alcohols and phenols. This heterogenized catalyst could be reused several times without loss of its catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.
Study of carbonization behavior of polyacrylonitrile/tin salt as anode material for lithium‐ion batteries
Authors: Wang Haiying , Zhang Xiu , Zhang Yaojie , Cheng Na , Yu Tingyue , Yang Yang , Yang Gang
Published: June 2016

Using polyacrylonitrile (PAN) as a template, a composite of tin salt/PAN nanofiber is facilely produced by an electrospinning technique. Under high‐temperature heat treatment, the carbonization of PAN and the crystal growth of tin oxide proceed simultaneously to form a composite structure of tin nanoparticles wrapped in carbon nanofibers (tin@CNF). The composite structure of tin@CNF is controllable by the precursor ratio of PAN with tin salt and the carbonization temperature. The sample Sn1Pan1_700, synthesized from the precursor with weight ratio of SnCl2:PAN = 1:1 and carbonized at 700 °C, delivers the initial capacity of 1329.8 mAh g−1 and remains at 741.1 mAh g−1 at the 40th cycle. The proper morphology of tin nanoparticles wrapped in carbon nanofibers plays an important role in specific capacity and cyclic performance, because the proper structure of carbon fiber hinders the aggregation of tin nanoparticles during the lithiation and delithiation processes. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016
A methacrylate monomer bearing nitro, aryl, and hydroxyl side groups: Homopolymerization, characterization, dielectric, and thermal degradation behaviors
Authors: Biryan Fatih , Demirelli Kadir
Published: June 2016

2‐Hydroxy‐3‐(4‐nitrophenoxy)propyl methacrylate (HNPPMA) monomer was synthesized. The poly(HNPPMA) was prepared by free radical polymerization (FRP) method. The characterization of poly(HNPPMA) was carried out using FT‐IR, NMR, differential scanning calorimetry, and GPC techniques. The thermal stability and degradation behavior of this polymer have been studied by using thermogravimetry (TG), GC‐MS, NMR, and FT‐IR. The results were in comparison to poly[2‐hydroxy‐3‐(1‐naphtyloxy)propyl methacrylate] sample with α‐naphtyloxy side group prepared by the same method in the our previous study. The effect of thermal activation on non‐isothermal decomposition kinetics of poly(HNPPMA) was investigated using thermogravimetric analysis according to Flynn‐Wall‐Ozawa method. The dielectric measurements of poly(HNPPMA) and doped with europium(III)chloride (EuCI3) were investigated by impedance analyzer technique in range of 10–4000 Hz frequency by depending on the alternating current conductivities. The mode of thermal degradation including formation of the main products of poly(HNPPMA) degraded from ambient temperature to 500 °C was identified. S°, the cold ring fraction (CRF) was collected from room temperature to 500 °C. The structure of the degradation products has also been studied depending on the GC‐MS analysis. The thermal degradation mechanism for poly(HNPPMA) with radical degradation processes thought to dominate at high temperature was proposed based on GC/MS, NMR, FT‐IR, and taking into account the new products and differences in stability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43925.
Polypyrrole‐wrapped Pd nanoparticles hollow capsules as a catalyst for reduction of 4‐nitroaniline
Authors: Zou Hanzhi , Shang Mengyin , Ren Guohong , Wang Wenqin
Published: June 2016

In this study, by in situ reduction of Pd2+ ions attached on the surface of the sulfonated polystyrene (PS‐SO3H) spheres, complete and dense palladium (Pd) nanoparticles (NPs) layer were deposited around PS‐SO3H spheres. The PS@Pd spheres were wrapped by polypyrrole (PPy) shell, which could avoid escaping of Pd NPs. After selectively etching the PS core, the hollow structures with Pd NPs embedded in PPy capsule shell were obtained. The as‐prepared Pd@PPy hollow capsules showed excellent catalytic activity toward the reduction of 4‐nitroaniline because of the high Pd NPs loading. Furthermore, good reusabilty was demonstrated seven times without any detectible loss in activity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43933.
Development and characterization of green composites from bio‐based polyethylene and peanut shell
Authors: Garcia‐Garcia Daniel , Carbonell‐Verdu Alfredo , Jordá‐Vilaplana Amparo , Balart Rafael , Garcia‐Sanoguera David
Published: June 2016

In the present work, different compatibilizers, namely polyethylene‐graft‐maleic anhydride (PE‐g‐MA), polypropylene‐graft‐maleic anhydride (PP‐g‐MA), and polystyrene‐block‐poly(ethylene‐ran‐butylene)‐block‐polystyrene‐graft‐maleic anhydride (SEBS‐g‐MA) were used on green composites derived from biobased polyethylene and peanut shell (PNS) flour to improve particle–polymer interaction. Composites of high‐density polyethylene/peanut shell powder (HDPE/PNS) with 10 wt % PNS flour were compatibilized with 3 wt % of the abovementioned compatibilizers. As per the results, PP‐g‐MA copolymer lead to best optimized properties as evidenced by mechanical characterization. In addition, best particle–matrix interface interactions with PP‐g‐MA were observed by scanning electron microscopy (SEM). Subsequently HDPE/PNS composites with varying PNS flour content in the 5–30 wt % range with PP‐g‐MA compatibilizer were obtained by melt extrusion and compounding followed by injection molding and were characterized by mechanical, thermal, and morphological techniques. The results showed that PNS powder, leads to an increase in mechanical resistant properties (mainly, flexural modulus, and strength) while a decrease in mechanical ductile properties, that is, elongation at break and impact absorbed energy is observed with increasing PNS flour content. Furthermore, PNS flour provides an increase in thermal stability due to the natural antioxidant properties of PNS. In particular, composites containing 30 wt % PNS powder present a flexural strength 24% and a flexural modulus 72% higher than the unfilled polyethylene and the thermo‐oxidative onset degradation temperature is increased from 232 °C up to 254 °C thus indicating a marked thermal stabilization effect. Resultant composites can show a great deal of potential as base materials for wood plastic composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43940.
Preparation and characterization of the modulus intermediate layer in carbon fiber/epoxy composites by depositing sepiolites
Authors: Yang Qing , Zhang Qingjie , Chen Xin , Deng Xi , Qi Shengli , Sui Gang , He Zhouwen , Lan Fengtao , Wu Dezhen , Yang Xiaoping
Published: June 2016

An important aspect in development of multi‐scale reinforced composites is their mass production which can be easily realized. In this article, the sepiolites (Si12O30Mg8(OH)4(OH2)4·8H2O) are directly deposited onto the surface of JH‐T800 carbon fibers for the first time with no need for removal of the commercial sizing agent. The sepiolites adhering to the carbon fibers are uniformly distributed with random orientation, and participated in the formation of high modulus intermediate layer encompassing the carbon fiber. After the deposition of sepiolites, the interfacial shear strengths (IFSS) of the carbon fiber/epoxy composites are significantly improved as shown in single‐fiber composite fragmentation tests. Compared to the commercial carbon fiber composites, the sepiolite‐deposited fiber composites also exhibit obvious improvement in the interlaminar shear strength and flexural strength. As a new kind of multi‐scale reinforcement with industrial application value, the sepiolite‐deposited carbon fibers can further raise the level of mechanical properties of the existing carbon fiber reinforced composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43955.
Statins and Risk of Rheumatoid Arthritis: A Nested Case–Control Study
Authors: Tascilar Koray , Dell'Aniello Sophie , Hudson Marie , Suissa Samy
Published: June 2016

Objective

Statins have antiinflammatory/immunomodulatory effects that may be useful in preventing rheumatoid arthritis (RA), but previous observational studies about the risk of RA with statin use yielded conflicting results. The aim of this study was to determine whether high‐intensity statin treatment is associated with reduced risk of RA.

Methods

Using data from the UK Clinical Practice Research Datalink, we performed a nested case–control analysis in a population‐based cohort of patients who began receiving statins between 1997 and 2009 and were followed up until a first diagnosis of RA, death, end of registration with the physician's practice, or end of January 2011. For each case of RA, 10 age‐, sex‐, and calendar year–matched controls were randomly selected from risk sets. We estimated the hazard ratio (HR) of incident RA in the highest quintile of duration‐weighted average statin intensity compared to the lowest, using conditional logistic regression. Models were adjusted for smoking status, total cholesterol level, obesity, history of cardiovascular disease, coexistent autoimmune disease, hypothyroidism, and persistence with treatment.

Results

The cohort included 528,654 new users of statins, with 1,357 new cases of RA occurring during a mean follow‐up of 3.3 years, for an incidence rate of 7.9 per 10,000 person‐years. Cases were more likely to be smokers, to have other autoimmune diseases, and to have had lower total cholesterol levels at baseline. The incidence of RA was lower in the highest statin intensity quintile (adjusted HR 0.77 [95% confidence interval 0.63–0.95]) in comparison to the lowest quintile.

Conclusion

In this large population‐based study, high‐intensity statin treatment was associated with a reduced risk of RA in comparison to low‐intensity statin treatment.
Evaluation of the effectiveness of 3D vascular stereoscopic models in anatomy instruction for first year medical students
Authors: Cui Dongmei , Wilson Timothy D. , Rockhold Robin W. , Lehman Michael N. , Lynch James C.
Published: June 2016

The head and neck region is one of the most complex areas featured in the medical gross anatomy curriculum. The effectiveness of using three‐dimensional (3D) models to teach anatomy is a topic of much discussion in medical education research. However, the use of 3D stereoscopic models of the head and neck circulation in anatomy education has not been previously studied in detail. This study investigated whether 3D stereoscopic models created from computed tomographic angiography (CTA) data were efficacious teaching tools for the head and neck vascular anatomy. The test subjects were first year medical students at the University of Mississippi Medical Center. The assessment tools included: anatomy knowledge tests (prelearning session knowledge test and postlearning session knowledge test), mental rotation tests (spatial ability; presession MRT and postsession MRT), and a satisfaction survey. Results were analyzed using a Wilcoxon rank‐sum test and linear regression analysis. A total of 39 first year medical students participated in the study. The results indicated that all students who were exposed to the stereoscopic 3D vascular models in 3D learning sessions increased their ability to correctly identify the head and neck vascular anatomy. Most importantly, for students with low‐spatial ability, 3D learning sessions improved postsession knowledge scores to a level comparable to that demonstrated by students with high‐spatial ability indicating that the use of 3D stereoscopic models may be particularly valuable to these students with low‐spatial ability. Anat Sci Educ 10: 34–45. © 2016 American Association of Anatomists.
Prüfung der Standorteignung für Windenergieanlagen: Ein pragmatischer Ansatz
Authors: Rodenhausen Moritz , Moser Wolfgang , Hülsmann Christian , Bergemann Constantin , Könker Michael , McKenna Russell
Published: June 2016

Die baurechtlichen Anforderungen an Windenergieanlagen (WEA) in Deutschland verlangen eine Prüfung der Standorteignung für sowohl neue WEA als auch bestehende, benachbarte WEA. Unter Verwendung der bisherigen Verfahren ist es nicht möglich, die Prüfung der Standorteignung für alle WEA durchzuführen, wenn der Windpark aus WEA verschiedener Hersteller besteht. Um die Standorteignung für die bestehenden WEA dennoch zu gewährleisten und den Anforderungen der Behörden Genüge zu tun, werden die neuen WEA zunehmend mit reduzierter Leistung betrieben. Dieser Beitrag stellt eine Erweiterung des bisherigen Verfahrens für die Standorteignung nach DIBt 2012 vor. Aufwändige Lastberechnungen durch die Hersteller können vermieden werden. Das Verfahren kann neben den Herstellern auch durch Dritte angewandt werden, was beispielswiese die Prüfung der Standorteignung durch unabhängige Sachverständige erlaubt.
t‐boc synthesis of huwentoxin‐i through native chemical ligation incorporating a trifluoromethanesulfonic acid cleavage strategy
Authors: Thapa Parashar , Cabalteja Chino C. , Philips Edwin E. , Espiritu Michael J. , Peigneur Steve , Mille Bea G. , Tytgat Jan , Cummins Theodore R. , Bingham Jon‐Paul
Published: June 2016

Tert‐butyloxycarbonyl (t‐Boc)‐based native chemical ligation (NCL) techniques commonly employ hydrogen fluoride (HF) to create the thioester fragment required for the ligation process. Our research aimed to assess the replacement of HF with Trifluoromethanesulfonic acid (TFMSA). Here we examined a 33 amino acid test peptide, Huwentoxin‐I (HwTx‐I) as a novel candidate for our TFMSA cleavage protocol. Structurally HwTx‐I has an X‐Cys16‐Cys17‐X sequence mid‐region, which makes it an ideal candidate for NCL. Experiments determined that the best yields (16.8%) obtained for 50 mg of a thioester support resin were achieved with a TFMSA volume of 100 μL with a 0.5‐h incubation on ice, followed by 2.0 h at room temperature. RP‐HPLC/UV and mass spectra indicated the appropriate parent mass and retention of the cleaved HwTx‐I N‐terminal thioester fragment (Ala1‐Cys16), which was used in preparation for NCL. The resulting chemically ligated HwTx‐I was oxidized/folded, purified, and then assessed for pharmacological target selectivity. Native‐like HwTx‐I produced by this method yielded an EC50 value of 340.5 ± 26.8 nM for Nav1.2 and an EC50 value of 504.1 ± 81.3 nM for Nav1.3, this being similar to previous literature results using native material. This article represents the first NCL based synthesis of this potent sodium channel blocker. Our illustrated approach removes potential restrictions in the advancement of NCL as a common peptide laboratory technique with minimal investment, and removes the hazards associated with HF usage. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 737–745, 2016.
Copy‐number variation of MCL1 predicts overall survival of non‐small‐cell lung cancer in a Southern Chinese population
Authors: Yin Jieyun , Li Yangkai , Zhao Hao , Qin Qin , Li Xiaorong , Huang Jiao , Shi Yun , Gong Shufang , Liu Li , Fu Xiangning , Nie Shaofa , Wei Sheng
Published: June 2016

BCL2L1 and MCL1 are key anti‐apoptotic genes, and critical for cancer progression. The prognostic values of BCL2L1 and MCL1 copy‐number variations (CNVs) in non‐small‐cell lung cancer (NSCLC) remain largely unknown. Somatic CNVs in BCL2L1 and MCL1 genes were tested in tumor tissues from 516 NSCLC patients in southern China; afterward, survival analyses were conducted with overall survival (OS) as outcome. Additionally, the associations between CNVs and mRNA expression levels were explored using data from 986 NSCLC patients in the Cancer Genome Atlas project. It was found that amplifications of BCL2L1 and MCL1 were associated with unfavorable OS of NSCLC, with adjusted hazards ratio of 1.62 (95% confident interval [CI] = 1.10–2.40; P = 0.015) and 1.39 (95% CI = 1.05–1.84; P = 0.020), respectively. Amplifications of MCL1, but not BCL2L1, were related with higher mRNA expression levels of corresponding gene, compared with non‐amplifications (P = 0.005). Interestingly, after incorporating with MCL1 CNV status, clinical variables (age, sex, TNM stage, and surgical approach) showed an improved discriminatory ability to classify OS (area under curve increased from 72.2% to 74.1%; P = 0.042, DeLong's test). Overall, MCL1 CNV might be a prognostic biomarker for NSCLC, and additional investigations are needed to validate our findings.
Bioactive Secondary Metabolites from Schizogyne sericea (Asteraceae) Endemic to Canary Islands
Authors: Venditti Alessandro , Bianco Armandodoriano , Muscolo Camilla , Zorzetto Christian , Sánchez‐Mateo Candelaria C. , Rabanal Rosa M. , Quassinti Luana , Bramucci Massimo , Damiano Silvia , Iannarelli Romilde , Lupidi Giulio , Papa Fabrizio , Petrelli Dezemona , Vitali Luca A. , Vittori Sauro , Maggi Filippo
Published: June 2016

Schizogyne sericea (Asteraceae) is a halophytic shrub endemic to the Canary Islands and traditionally employed as analgesic, astringent, anti‐inflammatory, and vulnerary. A comprehensive phytochemical investigation was conducted on the flowering aerial parts by analyzing both essential oil constituents and polar compounds. The essential oil was dominated by p‐cymene, with the noteworthy occurrence of β‐pinene and thymol esters. From the EtOH extract, eight compounds were isolated and structurally elucidated. Essential oil, polar fractions, and isolates (2), (4), and (5) were separately in vitro assayed for antiproliferative activity on human tumor cell lines (A375, MDA‐MB 231, and HCT116) by MTT assay, for antioxidant potential by DPPH, ABTS, and FRAP assays, and for antimicrobial activity by the agar disk diffusion method. Results revealed that essential oil and compounds 1 and 2 exert a strong inhibition on tumor cells, and in some cases, higher than that of cisplatin. Fractions containing thymol derivatives (1 and 2) and caffeoylquinic acid derivatives 4 and 5 displayed antioxidant activity comparable to that of Trolox, making S. sericea extract an interesting natural product with potential applications as preservative or in the treatment of diseases in which oxidative stress plays an important role.
Molecular Phylogeny, Diversity, and Bioprospecting of Endophytic Fungi Associated with wild Ethnomedicinal North American Plant Echinacea purpurea (Asteraceae)
Authors: Carvalho Camila R. , Wedge David E. , Cantrell Charles L. , Silva‐Hughes Alice F. , Pan Zhiqiang , Moraes Rita M. , Madoxx Victor L. , Rosa Luiz H.
Published: June 2016

The endophytic fungal community associated with the ethnomedicinal plant Echinacea purpurea was investigated as well as its potential for providing antifungal compounds against plant pathogenic fungi. A total of 233 endophytic fungal isolates were obtained and classified into 42 different taxa of 16 genera, of which Alternaria alternata, Colletotrichum dematium, and Stagonosporopsis sp. 2 are the most frequent colonizers. The extracts of 29 endophytic fungi displayed activities against important phytopathogenic fungi. Eight antifungal extracts were selected for chemical analysis. Forty fatty acids were identified by gas chromatography‐flame‐ionization detection (GC‐FID) analysis. The compounds (–)‐5‐methylmellein and (–)‐(3R)‐8‐hydroxy‐6‐methoxy‐3,5‐dimethyl‐3,4‐dihydroisocoumarin were isolated from Biscogniauxia mediterraneaEPU38CA crude extract. (–)‐5‐Methylmellein showed weak activity against Phomopsis obscurans, P. viticola, and Fusarium oxysporum, and caused growth stimulation of C. fragariae, C. acutatum, C. gloeosporioides, and Botrytis cinerea. (–)‐(3R)‐8‐Hydroxy‐6‐methoxy‐3,5‐dimethyl‐3,4‐dihydroisocoumarin appeared slightly more active in the microtiter environment than 5‐methylmellein. Our results indicate that E. purpurea lives symbiotically with different endophytic fungi, which are able to produce bioactive fatty acids and aromatic compounds active against important phytopathogenic fungi. The detection of the different fatty acids and aromatic compounds produced by the endophytic community associated with wild E. purpurea suggests that it may have intrinsic mutualistic resistance against phytopathogen attacks in its natural environment.