bluuebunny/crossref_metadata_2025_split huggingface dataset:
Observational evidence of the influence of Antarctic stratospheric ozone variability on middle atmosphere dynamics
Authors: Venkateswara Rao N. , Espy P. J. , Hibbins R. E. , Fritts D. C. , Kavanagh A. J. 
Published: September 2015

AbstractModeling results have suggested that the circulation of the stratosphere and mesosphere in spring is strongly affected by the perturbations in heating induced by the Antarctic ozone hole. Here using both mesospheric MF radar wind observations from Rothera Antarctica (67°S, 68°W) as well as stratospheric analysis data, we present observational evidence that the stratospheric and mesospheric wind strengths are highly anti‐correlated, and show their largest variability in November. We find that these changes are related to the total amount of ozone loss that occurs during the Antarctic spring ozone hole and particularly with the ozone gradients that develop between 57.5°S and 77.5°S. The results show that with increasing ozone loss during spring, winter conditions in the stratosphere and mesosphere persist longer into the summer. These results are discussed in the light of observations of the onset and duration of the Antarctic polar mesospheric cloud season.
The origin of water vapor rings in tropical oceanic cold pools
Authors: Langhans Wolfgang , Romps David M. 
Published: September 2015

AbstractTropical deep convection over the ocean is found to grow preferentially from thermodynamically preconditioned regions of high specific humidity and, thus, high moist static energy. For this reason, rings of enhanced specific humidity at the leading edges of evaporatively driven cold pools have recently received considerable attention. The prevailing theory explains these rings by the water vapor source from the evaporation of rain drops below cloud base. Their origin is studied in this letter using large‐eddy simulations of individual cumulus clouds that rise into a tropical atmosphere over ocean. It is demonstrated that—in contrast to this theory—water vapor rings are primarily explained by surface latent heat fluxes rather than by the evaporation of rain. This finding implies that conceptual models used in subgrid‐scale parameterizations of deep convection should consider the formation of rings of increased specific humidity by the cold‐pool‐induced enhancement of surface fluxes.
Clusters, deformation, and dilation: Diagnostics for material accumulation regions
Authors: Huntley Helga S. , Lipphardt B. L. , Jacobs Gregg , Kirwan A. D. 
Published: September 2015

AbstractClusters of material at the ocean surface have been frequently observed. Such accumulations of material play an important role in a variety of applications, from biology to pollution mitigation. Identifying where clusters will form can aid in locating, for example, hotspots of biological activity or regions of high pollutant concentration. Here cluster strength is introduced as a new metric for defining clusters when all particle positions are known. To diagnose regions likely to contain clusters without the need to integrate millions of particle trajectories, we propose to use dilation, which quantifies area changes of Lagrangian patches. Material deformation is decomposed into dilation and area‐preserving stretch processes to refine previous approaches based on finite‐time Lyapunov exponents (FTLE) by splitting the FTLE into fundamental kinematic properties. The concepts are developed theoretically and illustrated in the context of a state‐of‐the‐art data‐assimilating predictive ocean model of the Gulf of Mexico. Regions of dilation less than one are shown to be much more likely (6 times more likely in the given example) to be visited by particles than those of dilation greater than one. While the relationship is nonlinear, dilation and cluster strength exhibit a fairly good correlation. In contrast, both stretch and Eulerian divergence are found to be uncorrelated with cluster strength. Thus, dilation maps can be used as guides for identifying cluster locations, while saving some of the computational cost of trajectory integrations.
Upper ocean response and feedback to spring weather over the Kuroshio in the East China Sea: A coupled atmosphere‐ocean model study
Authors: Kueh Mien‐Tze , Lin Pay‐Liam 
Published: September 2015

AbstractThis study investigated the air‐sea interaction over the Kuroshio in the East China Sea by focusing on the response and feedback of the ocean to typical spring weather events. The Weather Research and Forecasting Model was coupled with the HYbrid Coordinate Ocean Model for use in the study. The study period comprised a sequence of typical weathers in the area: prevailing southwesterly winds, the passage of a cold front and the ensuing cold‐air outbreak, and the development of a Taiwan low. The air‐sea interaction operated on a diurnal time scale under conditions of moderate wind speeds, high insolation, and a shallow oceanic mixed layer. The sea surface temperature and upper ocean heat content increased progressively prior to the frontal passage. The model reproduced the retreat of Kuroshio in response to the strong wind during the cold‐air outbreak. The diurnal cycle vanished at high wind speeds. Wind stirring eroded the upper seasonal thermocline and deepened the oceanic mixed layer. The upper ocean heat content decreased because of entrainment cooling and surface heat losses. Surface restratification was subsequently suppressed in the thick and weakly stratified remnant layer. The consequently insufficient recovery of upper ocean heat content may have preconditioned a stagnation of the Taiwan low. The recovery of upper ocean heat content was discussed to derive the implication for climate simulations.
Investigation on thermal behavior and sulfur release characteristics from rice husk and bituminous coal co‐firing under O2/CO2 atmosphere
Authors: Huang Yaji , Zhang Lihui , Duan Feng 
Published: September 2015

AbstractThe synergistic interaction of rice husk (RH), Huaibei bituminous coal (HB coal), and their blends was investigated under O2/CO2 combustion condition by thermogravimetric analysis. The RH was blended with HB coal in the range of 20–40 wt% to investigate the co‐combustion profile. Meanwhile, a horizontal tube furnace was used to study the sulfur release characteristics of blended fuels under O2/CO2 atmosphere. Results showed that the synergistic interaction between RH and HB coal improved the char catalytic effect and alkali metals melt‐induced effect on the decomposition of HB coal. Burnout temperature (Tb) of blended fuels decreases significantly with an increase of RH ratio and oxygen ratio, ignition temperature (Ti) decreases with increases of RH ratio, while there is a minor decrease in Ti at higher oxygen ratio. Combustion characteristic indexes of blended fuel increase with an increase of RH ratio and oxygen ratio. The SO2 peak values decrease with increases of RH ratio, and increase with an increase of oxygen ratio and temperature. However, the mean SO2 emissions and fuel‐S conversions show the inverse trend. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd.
Self‐Sustained Resistance to Suppression of CD8+ Teff Cells at the Site of Autoimmune Inflammation Can Be Reversed by Tumor Necrosis Factor and Interferon‐γ Blockade
Authors: Petrelli Alessandra , Wehrens Ellen J. , Scholman Rianne C. , Prakken Berent J. , Vastert Sebastian J. , van Wijk Femke 
Published: September 2015

ObjectiveResistance of Teff cells to Treg cell–mediated suppression contributes to the breakdown of peripheral tolerance in the inflamed joints of patients with juvenile idiopathic arthritis (JIA). However, unanswered questions are whether this resistant phenotype is self‐sustained and whether CD8+ and CD4+ Teff cells share the same mechanism of resistance to suppression. We undertook this study to investigate intrinsic resistance of CD8+ Teff cells to suppression and to determine how this can be targeted therapeutically.MethodsCD8+ or CD4+ Teff cells were cultured with or without antigen‐presenting cells (APCs) in Treg cell–dependent and –independent suppression assays. Synovial fluid (SF)–derived Teff cells were crosscultured with peripheral blood (PB) Treg cells from JIA patients or healthy controls. Tumor necrosis factor (TNF) or interferon‐γ (IFNγ) blocking agents were used to restore Teff cell responsiveness to suppression.ResultsSuppression of cell proliferation and cytokine production in CD8+ Teff cells from the SF of JIA patients was severely impaired compared to that in CD8+ Teff cells from the PB of JIA patients, regardless of the presence of APCs and CD4+ Teff cells. Similar to CD4+ Teff cells, impaired suppression of CD8+ Teff cells was shown to be an intrinsic feature of this cell population. While TNF blockade restored both CD8+ and CD4+ Teff cell susceptibility to suppression, autocrine release of IFNγ selectively sustained CD8+ Teff cell resistance, which could be relieved by IFNγ blockade.ConclusionUnlike CD4+ Teff cells, resistance of CD8+ Teff cells to suppression at the site of autoimmune inflammation is maintained by autocrine release of IFNγ, and blockade of IFNγ restores CD8+ Teff cell responsiveness to suppression. These findings indicate a potential therapeutic value of blocking IFNγ to restore immune regulation in JIA.
Opioid Use and Risk of Nonvertebral Fractures in Adults With Rheumatoid Arthritis: A Nested Case–Control Study Using Administrative Databases
Authors: Acurcio Francisco A. , Moura Cristiano S. , Bernatsky Sasha , Bessette Louis , Rahme Elham 
Published: September 2015

ObjectiveTo assess the risk of nonvertebral fractures in patients with rheumatoid arthritis (RA) who were exposed to opioids.MethodsA population‐based, nested case–control study was conducted using health services administrative databases (Quebec, Canada) from 1997 to 2012. Among RA patients, cases of nonvertebral fractures from 2007 to 2012 were identified using a validated algorithm. The date of the first fracture was the index date for the case and his/her matched control. Controls were selected using incidence density sampling and were matched 5:1 to cases for age, sex, and date of RA diagnosis. Opioid exposure was classified as current use, recent past use, remote past use, and nonuse. Conditional logistic regression was used to assess the association of nonvertebral fractures with opioid exposure, adjusting for comorbidity, indicators of RA severity, drugs influencing fracture risk, and health care utilization.ResultsIn total, 1,723 cases and 8,046 controls were identified. Among these patients, 2,595 (722 cases and 1,873 controls) had been exposed to opioids. Current use (versus nonuse) increased the risk of nonvertebral fracture. Cumulative current use of opioids according to the quartile distribution was also associated with the risk of nonvertebral fracture: for continuous use for 1–20 days before the index date, odds ratio (OR) 11.49 (95% confidence interval [95% CI] 8.81–14.99); for 21–155 days, OR 1.75 (95% CI 1.31–2.33); for 156–355 days, OR 1.54 (95% CI 1.17–2.04); and for ≥356 days, OR 1.73 (95% CI 1.31–2.30). No association between the risk of nonvertebral fractures and recent past use or remote past use of opioids was observed.ConclusionAmong RA patients, the risk of nonvertebral fracture is increased in those treated with opioids.
Derepression of MicroRNA‐138 Contributes to Loss of the Human Articular Chondrocyte Phenotype
Authors: Seidl Christine I. , Martinez‐Sanchez Aida , Murphy Christopher L. 
Published: September 2015

ObjectiveTo investigate the function of microRNA‐138 (miR‐138) in human articular chondrocytes (HACs).MethodsThe expression of miR‐138 in intact cartilage and cultured chondrocytes and the effects of miR‐138 overexpression on chondrocyte marker genes were investigated. Targets of miR‐138 relevant to chondrocytes were identified and verified by overexpression of synthetic miRNA mimics and inhibitors, luciferase assays, chromatin immunoprecipitation, and RNA immunoprecipitation of native argonaute 2, using quantitative polymerase chain reaction, Western blotting, and luciferase assays.ResultsExpression levels of miR‐138 were maintained at relatively low levels in intact human cartilage but were greatly increased upon loss of the differentiated phenotype in culture, with a concomitant decrease in the major cartilage extracellular matrix component COL2A1. We showed that miR‐138 is able to repress the expression of COL2A1 by directly targeting Sp‐1 and hypoxia‐inducible factor 2α (HIF‐2α), 2 transcription factors that are essential for COL2A1 transcription. We further demonstrated a direct association of these targets with miR‐138 in the RNA‐induced silencing complex and confirmed binding of Sp‐1 to the COL2A1 promoter region in HACs.ConclusionWe propose that an evolutionary pressure helps to suppress expression levels of miR‐138 in human cartilage, thus enabling expression of appropriate tissue‐specific matrix genes. Inhibition of miR‐138 may serve as a potential therapeutic strategy to maintain the chondrocyte phenotype or reduce the progression of dedifferentiation in cultured HACs.
Cation‐tunable blue phosphor Ca2PO4Cl:Eu2+: enhancive emission and site occupancy
Authors: Chen Wanping , Zhou Ahong 
Published: September 2015

AbstractA series of blue phosphors Ca1.98–xMxPO4Cl:0.02Eu2+ (M = Mg and Sr) with different values of x were synthesized using a high‐temperature solid‐state reaction. X‐Ray diffraction and photoluminescence measurements were used to study the phase structure and luminescence properties. Ca2PO4Cl:0.02Eu2+ exhibits a tunable emission intensity and color due to the incorporation of Sr2+ or Mg2+. The incorporation of Sr2+ reduces the luminescence intensity and results in a slight red shift in the emission band. The incorporation of Mg2+ results in enhanced emission and a clear blue shift in the emission band along with a tunable chromatic coordination. Under excitation at λ = 334 nm, the emission intensity of the Mg2+‐doped Ca2PO4Cl:0.02Eu2+ is found to be 250% that of Ca2PO4Cl:0.02Eu2+. The luminescence behaviors of the as‐synthesized phosphors are discussed according to the host crystal structure and site occupancy of Eu2+. The results indicate that Mg2+‐doped Ca2PO4Cl:Eu2+ is more applicable as a near‐UV‐convertible blue phosphor for white light‐emitting diodes. Copyright © 2015 John Wiley & Sons, Ltd.
Rapidly progressive sarcomatoid malignant mesothelioma of the pleura mimicking pulmonary empyema
Authors: Fujita Kohei , Kim Young Hak , Nakatani Koichi , Mio Tadashi 
Published: September 2015

Key Clinical MessageRefractory empyema occasionally reflects hidden malignant disease. We presented a rare case of rapidly progressive malignant mesothelioma of the pleura (MPM) mimicking empyema. Physicians should be aware of MPM when patients with empyema are refractory to the standard treatment, and PET‐CT may be helpful in establishing a precise diagnosis in such cases.
Aliphatic Hydrocarbons from Lignocellulose by Pyrolysis over Cesium‐Modified Amorphous Silica Alumina Catalysts
Authors: Zabeti Masoud , Sai Sankar Gupta Karthick Babu , Raman Ganesan , Lefferts Leon , Schallmoser Stefan , Lercher Johannes A. , Seshan K. 
Published: September 2015

AbstractCesium‐modified amorphous silica alumina (Cs/ASA) is a promising catalyst for the production of hydrocarbons through pyrolysis of biomass. Catalytic pyrolysis of pinewood over Cs/ASA in a pyrolyzer system in conjunction with a gas chromatograph and mass spectrometer resulted in a 22 % yield of hydrocarbons containing more than 50 % aliphatic hydrocarbons. Factors such as the nature of the support and the concentration of Cs+ ions influenced the catalyst activity for the production of hydrocarbons. Physicochemical characterization showed that the cesium exists in the form of Cs2CO3, which interacts strongly with the ASA support.
Functionalization of CnH2n+2 Alkanes: Supercritical Carbon Dioxide Enhances the Reactivity towards Primary Carbon–Hydrogen Bonds
Authors: Gava Riccardo , Olmos Andrea , Noverges Bárbara , Varea Teresa , Funes‐Ardoiz Ignacio , Belderrain Tomás R. , Caballero Ana , Maseras Feliu , Asensio Gregorio , Pérez Pedro J. 
Published: September 2015

AbstractThe functionalization of the primary sites of alkanes is one of the more challenging areas in catalysis. In this context, a novel effect has been discovered that is responsible for an enhancement in the reactivity of the primary C−H bonds of alkanes in a catalytic system. The copper complex
Cu(NCMe) (
=hydrotris{[3,5‐bis(trifluoromethyl)‐4‐bromo]‐pyrazol‐1‐yl}borate) catalyzes the functionalization of CnH2n+2 with ethyl diazoacetate upon inserting the CHCO2Et unit into C−H bonds. In addition, the selectivity of the reaction toward the primary sites significantly increased relative to that obtained in neat alkane upon using supercritical carbon dioxide as the reaction medium. This was attributed to the effect of the carbon dioxide molecules that withdraw electron density from the fluorine atoms of the ligand, which enhances the electrophilic nature of the metal center. DFT studies validated this proposal.
A Green Chemoenzymatic Process for the Synthesis of Azoxybenzenes
Authors: Yang Fengjuan , Wang Zhi , Zhang Xiaowen , Jiang Liyan , Li Yazhuo , Wang Lei 
Published: September 2015

AbstractAn efficient chemoenzymatic process for the synthesis of azoxybenzenes was developed. A peracid was generated in situ by Novozym 435, and then a range of anilines were oxidized by the produced peracid to afford azoxybenzenes in yields ranging from 63.1 to 94.1 %. This method expands the application of lipase in organic synthesis and provides an alternative method for the synthesis of azoxybenzenes.
Monitoring and Understanding the Paraelectric–Ferroelectric Phase Transition in the Metal–Organic Framework [NH4][M(HCOO)3] by Solid‐State NMR Spectroscopy
Authors: Xu Jun , Lucier Bryan E. G. , Sinelnikov Regina , Terskikh Victor V. , Staroverov Viktor N. , Huang Yining 
Published: September 2015

AbstractThe paraelectric–ferroelectric phase transition in two isostructural metal–organic frameworks (MOFs) [NH4][M(HCOO)3] (M=Mg, Zn) was investigated by in situ variable‐temperature 25Mg, 67Zn, 14N, and 13C solid‐state NMR (SSNMR) spectroscopy. With decreasing temperature, a disorder–order transition of NH4+ cations causes a change in dielectric properties. It is thought that [NH4][Mg(HCOO)3] exhibits a higher transition temperature than [NH4][Zn(HCOO)3] due to stronger hydrogen‐bonding interactions between NH4+ ions and framework oxygen atoms. 25Mg and 67Zn NMR parameters are very sensitive to temperature‐induced changes in structure, dynamics, and dielectric behavior; stark spectral differences across the paraelectric–ferroelectric phase transition are intimately related to subtle changes in the local environment of the metal center. Although 25Mg and 67Zn are challenging nuclei for SSNMR experiments, the highly spherically symmetric metal‐atom environments in [NH4][M(HCOO)3] give rise to relatively narrow spectra that can be acquired in 30–60 min at a low magnetic field of 9.4 T. Complementary 14N and 13C SSNMR experiments were performed to probe the role of NH4+–framework hydrogen bonding in the paraelectric–ferroelectric phase transition. This multinuclear SSNMR approach yields new physical insights into the [NH4][M(HCOO)3] system and shows great potential for molecular‐level studies on electric phenomena in a wide variety of MOFs.
Synthesis, Structure, and Reactivities of Iminosulfane‐ and Phosphane‐Stabilized Carbones Exhibiting Four‐Electron Donor Ability
Authors: Morosaki Tomohito , Wang Wei‐Wei , Nagase Shigeru , Fujii Takayoshi 
Published: September 2015

AbstractIminosulfane(phosphane)carbon(0) derivatives (iSPCs; Ar3P→C←SPh2(NMe); Ar=Ph (1), 4‐MeOC6H4 (2), 4‐(Me2N)C6H4 (3)) have been successfully synthesized and the molecular structure of 3 characterized. Carbone 3 is the first thermally and hydrolytically stable carbone stabilized by phosphorus and sulfur ligands. DFT calculations reveal the electronic structures of 1–3, which have two lone pairs of electrons at the carbon center. First and second proton affinity values are theoretically calculated to be in the range of 286.8–301.1 and 189.6–208.3 kcal mol−1, respectively. Cyclic voltammetry measurements reveal that the HOMO energy levels follow the order of 3>2>1 and the HOMO of 3 is at a higher energy than those of bis(chalcogenane)carbon(0) (BChCs). The reactivities of these lone pairs of electrons are demonstrated by the C‐diaurated and C‐proton‐aurated complexes. These results are the first experimental evidence of phosphorus‐ and sulfur‐stabilized carbones behaving as four‐electron donors. In addition, the reaction of hydrochloric salts of the carbones with Ag2O gives the corresponding AgI complexes. The resulting silver(I) carbone complexes can be used as carbone transfer agents. This synthetic protocol can also be used for moisture‐sensitive carbone species.
Gas‐Phase Partial Oxidation of Lignin to Carboxylic Acids over Vanadium Pyrophosphate and Aluminum–Vanadium–Molybdenum
Authors: Lotfi Samira , Boffito Daria C. , Patience Gregory S. 
Published: September 2015

AbstractLignin is a complex polymer that is a potential feedstock for aromatic compounds and carboxylic acids by cleaving the β‐O‐4 and 5‐5′ linkages. In this work, a syringe pump atomizes an alkaline solution of lignin into a catalytic fluidized bed operating above 600 K. The vanadium heterogeneous catalysts convert all the lignin into carboxylic acids (up to 25 % selectivity), coke, carbon oxides, and hydrogen. Aluminum–vanadium–molybdenum mostly produced lactic acid (together with formic acid, acrylic acid, and maleic anhydride), whereas the vanadium pyrophosphate catalyst produced more maleic anhydride.