bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of recent sea surface temperature trends on the Arctic stratospheric vortex
Authors: Garfinkel C. I. , Hurwitz M. M. , Oman L. D. 
Published: May 2015

AbstractComprehensive chemistry‐climate model experiments and observational data are used to show that up to half of the satellite era early springtime cooling trend in the Arctic lower stratosphere was caused by changing sea surface temperatures (SSTs). An ensemble of experiments forced only by changing SSTs is compared to an ensemble of experiments in which both the observed SSTs and chemically and radiatively active trace species are changing. By comparing the two ensembles, it is shown that warming of Indian Ocean, North Pacific, and North Atlantic SSTs and cooling of the tropical Pacific have strongly contributed to recent polar stratospheric cooling in late winter and early spring. When concentrations of ozone‐depleting substances and greenhouse gases are fixed, polar ozone concentrations show a small but robust decline due to changing SSTs. Ozone loss is larger in the presence of changing concentrations of ozone‐depleting substances and greenhouse gases. The stratospheric changes can be understood by examining the tropospheric height and heat flux anomalies generated by the anomalous SSTs. Finally, recent SST changes have contributed to a decrease in the frequency of late winter stratospheric sudden warmings.
Organic tracers of primary biological aerosol particles at subtropical Okinawa Island in the western North Pacific Rim
Authors: Zhu Chunmao , Kawamura Kimitaka , Kunwar Bhagawati 
Published: May 2015

AbstractPrimary biological aerosol particles (PBAPs) play an important role in affecting atmospheric physical and chemical properties. Aerosol samples were collected at Cape Hedo, Okinawa Island, Japan, from October 2009 to February 2012 and analyzed for five primary saccharides and four sugar alcohols as PBAP tracers. We detected high levels of sucrose in spring when blossoming of plants happens and prolifically emits pollen to the air. Concentrations of glucose, fructose, and trehalose showed levels higher than the other saccharides in spring in 2010. In comparison, primary saccharide levels were mutually comparable in spring, summer, and autumn in 2011, indicating the interannual variability of their local production in subtropical forests, which is driven by local temperature and radiation. High trehalose events were found to be associated with Asian dust outflows, indicating that Asian dust also contributes to PBAPs at Okinawa. Sugar alcohols peaked in summer and correlated with local precipitation and temperature, indicating high microbial activities. Positive matrix factorization analysis confirmed that the PBAPs are mainly derived from local vegetation, pollen, and fungal spores. A higher contribution of PBAP tracers to water‐soluble organic carbon (WSOC) was found in summer (14.9%). The annual mean ambient loadings of fungal spores and PBAPs were estimated as 0.49 µg m−3 and 4.12 µg m−3, respectively, using the tracer method. We report, for the first time, year‐round biomarkers of PBAP and soil dust and their contributions to WSOC in the subtropical outflow region of the Asian continent.
Identifying multiple time scale rainfall controls on Mojave Desert ecohydrology using an integrated data and modeling approach for Larrea tridentata
Authors: Ng Gene‐Hua Crystal , Bedford David R. , Miller David M. 
Published: May 2015

AbstractThe perennial shrub Larrea tridentata is widely successful in North American warm deserts but is also susceptible to climatic perturbations. Understanding its response to rainfall variability requires consideration of multiple time scales. We examine intra‐annual to multiyear relationships using model simulations of soil moisture and vegetation growth over 50 years in the Mojave National Preserve in southeastern California (USA). Ecohydrological model parameters are conditioned on field and remote sensing data using an ensemble Kalman filter. Although no specific periodicities were detected in the rainfall record, simulated leaf‐area‐index exhibits multiyear dynamics that are driven by multiyear (∼3 years) rains, but with up to a 1 year delay in peak response. Within a multiyear period, Larrea tridentata is more sensitive to winter rains than summer. In the most active part of the root zone (above ∼80 cm), >1 year average soil moisture drives vegetation growth, but monthly average soil moisture is controlled by root uptake. Moisture inputs reach the lower part of the root zone (below ∼80 cm) infrequently, but once there they can persist over a year to help sustain plant growth. Parameter estimates highlight efficient plant physiological properties facilitating persistent growth and high soil hydraulic conductivity allowing deep soil moisture stores. We show that soil moisture as an ecological indicator is complicated by bidirectional interactions with vegetation that depend on time scale and depth. Under changing climate, Larrea tridentata will likely be relatively resilient to shorter‐term moisture variability but will exhibit higher sensitivity to shifts in seasonal to multiyear moisture inputs.
Biocomposites based on poly(lactic acid) and seaweed wastes from agar extraction: Evaluation of physicochemical properties
Authors: Madera‐Santana Tomás J. , Freile‐Pelegrín Yolanda , Encinas José C. , Ríos‐Soberanis Carlos R. , Quintana‐Owen Patricia 
Published: May 2015

ABSTRACTSeaweed waste (SWW) is a residue or by‐product from the filtration step of the agar extraction process, and it has been explored as an inexpensive and effective filler for incorporation by melt blending into a poly(lactic acid) (PLA) matrix. PLA‐SWW biocomposites were manufactured with various contents of SWW (0, 5, 10, 15, and 20 wt %) using a sheet extrusion process. PLA was functionalized with maleic anhydride (MAH) by reactive extrusion using dicumyl peroxide (DCP) as an initiator, and it was extruded using 0, 5, and 20 wt %. SWW content. The mechanical, thermal, structural, and morphological properties of the processed biocomposites were investigated. Regarding the mechanical behavior, a slight increase in the tensile modulus was observed at low SWW content. The thermal properties indicated that the rigid amorphous phase content was enhanced in the biocomposites. This work suggests that SWW can be used as filler to develop environmental friendly biocomposites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42320.
Generation of nanofibers via electrostatic‐Induction‐assisted solution blow spinning
Authors: Tang Dingyou , Zhuang Xupin , Zhang Chan , Cheng Bowen , Li Xiaojie 
Published: May 2015

ABSTRACTIncreasing attention has been given to nanofiber fabrication techniques. Solution blow spinning (SBS) is an innovative, simple, and effective method for producing nanofibers, and it only uses the drawing force of high‐velocity airflow. However, solution‐blown nanofibers easily form bundles; this results in an uneven distribution of nanofibers and an inhomogeneity of nanofiber mats. In this study, electrostatic‐induction‐assisted solution blow spinning (EISBS) was established by the introduction of an additional electrostatic field with an induction circle electrode into the SBS system. The effects of the electrostatic force on the fiber configuration and structure were examined. The results indicate that the electrostatic field effectively separated the fibers. Response surface methodology, based on the four‐factor, three‐level Box–Behnken design, was used to facilitate a more systematic understanding of the processing parameters of EISBS. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42326.
High efficiency antimicrobial cellulose‐based nanocomposite hydrogels
Authors: Abou‐Yousef Hussein , Kamel Samir 
Published: May 2015

ABSTRACTCarboxymethyl cellulose hydrogels were developed through crosslinking process using maleic, succinic, or citric acids. The swelling capacities of the obtained hydrogels have been controlled through variation of the crosslinking reaction conditions. Further enhancement of the swelling properties was achieved by additional blending step of the carboxymethyl cellulose with polyethylene glycol. Biofunctionalization of the hydrogels was achieved through “in situ” incorporation of the silver nanoparticles during the crosslinked reaction. Chemical structure verifications and morphological characterizations of the hydrogels were performed using FTIR, XRD, EDX, and SEM analyses. Finally, the antimicrobial activity of the loaded silver hydrogels against G+ve, G−ve, and yeastCandida albicanswas demonstrated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2015,132, 42327.
Structure and property development of aromatic copolysulfonamide fibers during wet spinning process
Authors: Yu Jinchao , Tian Feng , Chen Shenghui , Wang Xiaofeng , Zhang Yumei , Wang Huaping 
Published: May 2015

ABSTRACTThe structure and performance changes of aromatic copolysulfonamide (co‐PSA) fibers that occurred during wet spinning process have been studied. While using different length scale characterization, including scan electron microscopy (SEM), wide‐angle X‐ray scattering (WAXS), and small‐angle X‐ray scattering (SAXS), it was found that the molecular chains of co‐PSA formed an isotropic network during coagulation which further lead to extension and orientation of these chains during the subsequent stretching. As a result, only after heat stretching and heat setting the molecular chains tended to pack into crystal lattice in the fibrils. This gave rise to a much denser structure along the spinning line and the glass transition temperature of co‐PSA fibers increased a little after heat setting. Before heat stretching, the co‐PSA fibers were in amorphous state, and only the amorphous orientation was observed within the fibers. After heat stretching at the temperature higher than Tg, the fraction of amorphous region decreased, and the crystal structure formed in the fibers, which became more perfect during heat setting. The structure development during spinning process contributed toward the improvement of thermo‐mechanical stability, tenacity and modulus of the co‐PSA fibers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42343.
High performance of the linked visible photoinitiator for free radical polymerization based on erythrosine B derivative
Authors: Nan Xuying , Huang Yi , Fan Qinguo , Shao Jianzhong 
Published: May 2015

ABSTRACTA novel erythrosine B derivative linked with a tertiary amine used as a visible light initiator for free radical polymerization was synthesized and characterized. For comparison, the free hydrophobic erythrosine B derivative was also synthesized and its combination with the tertiary amine was used as the separated two component photoinitiator. The linked initiator exhibited higher photoinitiator efficiency in high viscosity monomer than in low viscosity one, compared with the separated counterpart. Especially, when it was combined with iodonium salt, the further promotion of the photoinitiator efficiency was observed, compared with the separated three component system. It was found that as iodonium salt together with tertiary amine was continuously added to the formula with the linked initiator, the photoinitiator efficiency was dramatically enhanced compared with the same addition to the formula with the separated counterpart, revealing the application potential of the linked initiator. And the continuous addition of either the iodium salt or the tertiary amine to the formula only leaded to the small size increase of the photoinitiator efficiency. These results suggested that there existed an interdependent relationship between iodonium salt and tertiary amine in promoting the photoinitiator efficiency of the dye/amine/iodonium salt system. For these, the corresponding synergistic mechanism was proposed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42361.
Product Control in Alkene Trifluoromethylation: Hydrotrifluoromethylation, Vinylic Trifluoromethylation, and Iodotrifluoromethylation using Togni Reagent
Authors: Egami Hiromichi , Usui Yoshihiko , Kawamura Shintaro , Nagashima Sayoko , Sodeoka Mikiko 
Published: May 2015

AbstractHydrotrifluoromethylation, vinylic trifluoromethylation, and iodotrifluoromethylation of simple alkenes have been achieved by using Togni reagent in the absence of any transition metal catalyst. These reactions were readily controllable by selection of appropriate salts and solvents. The addition of K2CO3 afforded the hydrotrifluoromethylation product, with DMF acting not only as a solvent, but also as the hydrogen source. In contrast, the use of tetra‐n‐butylammonium iodide (TBAI) in 1,4‐dioxane resulted in vinylic trifluoromethylation, while the use of KI afforded the iodotrifluoromethylation product. The vinylic trifluoromethylation product was obtained by treatment of the iodotrifluoromethylation product with ammonium 2‐iodobenzoate, indicating that it was formed through an elimination reaction of the in‐situ‐generated iodotrifluoromethylation product, and the solubility of the resulting 2‐iodobenzoate salt plays a key role in the product switching. A radical‐clock experiment showed that these reactions proceed via radical intermediates.
Separation in flowering time contributes to the maintenance of sympatric cryptic plant lineages
Authors: Michalski Stefan G. , Durka Walter 
Published: May 2015

AbstractSympatric cryptic lineages are a challenge for the understanding of species coexistence and lineage diversification as well as for management, conservation, and utilization of plant genetic resources. In higher plants studies providing insights into the mechanisms creating and maintaining sympatric cryptic lineages are rare. Here, using microsatellites and chloroplast sequence data, morphometric analyses, and phenological observations, we ask whether sympatrically coexisting lineages in the common wetland plant Juncus effusus are ecologically differentiated and reproductively isolated. Our results show two genetically highly differentiated, homoploid lineages within J. effusus that are morphologically cryptic and have similar preference for soil moisture content. However, flowering time differed significantly between the lineages contributing to reproductive isolation and the maintenance of these lineages. Furthermore, the later flowering lineage suffered less from predispersal seed predation by a Coleophora moth species. Still, we detected viable and reproducing hybrids between both lineages and the earlier flowering lineage and J. conglomeratus, a coexisting close relative. Flowering time differentiation between the lineages can be explained by neutral divergence alone and together with a lack of postzygotic isolation mechanisms; the sympatric coexistence of these lineages is most likely the result of an allopatric origin with secondary contact.
Length of hospital stay and 30‐day readmission following heart failure hospitalization: insights from the EVEREST trial
Authors: Khan Hassan , Greene Stephen J. , Fonarow Gregg C. , Kalogeropoulos Andreas P. , Ambrosy Andrew P. , Maggioni Aldo P. , Zannad Faiez , Konstam Marvin A. , Swedberg Karl , Yancy Clyde W. , Gheorghiade Mihai , Butler Javed ,   on behalf of the EVEREST Trial Investigators
Published: May 2015

AimsPrevious reports have provided conflicting data regarding the relationship between length of stay (LOS) and subsequent readmission risk among patients hospitalized for heart failure (HF).Methods and resultsWe performed a post‐hoc analysis of the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study with Tolvaptan (EVEREST) trial to evaluate the differences in LOS overall and between geographic regions (North America, South America, Western Europe, and Eastern Europe) in association with all‐cause and cause‐specific [HF, cardiovascular (CV) non‐HF, and non‐CV] readmissions within 30 days of discharge after HF hospitalization. The present analysis included 4020 patients enrolled from 20 countries who were alive at discharge. Median [interquartile range (IQR)] LOS was 8 (4–11) days. The 30‐day readmission rates were 15.7% [95% confidence interval (CI) 14.6–16.8] for all‐cause; 5.6% (95% CI 4.9–6.3) for HF; 4.4% (95% CI 3.8–5.1) for CV non‐HF; and 5.8% (95% CI 5.1–6.6) for non‐CV readmissions. There was a positive correlation between LOS and all‐cause readmissions (r = 0.09, 95% CI 0.06–0.12). The adjusted odds ratio for the top (≥14 days) vs. the bottom (≤3 days) quintile for LOS was 1.39 (95% CI 0. 92–2.11) for all‐cause readmissions, 0.43 (95% CI 0.24–0.79) for HF, 2.99 (95% CI 1.49–6.02) for CV non‐HF, and 1.72 (95% CI 1.05–2.81) for non‐CV readmissions. With the exception of Western Europe, these findings remained largely consistent across geographic regions.ConclusionIn this large multinational cohort of hospitalized HF patients, longer LOS was associated with a higher risk for all‐cause, CV non‐HF, and non‐CV readmissions, but a lower risk of HF readmissions within 30 days of discharge. These results may inform strategies to reduce readmissions.
Minor genomic differences between related B6 and B10 mice affect severity of schistosome infection by governing the mode of dendritic cell activation
Authors: Smith Patrick M. , Sproule Thomas J. , Philip Vivek M. , Roopenian Derry C. , Stadecker Miguel J. 
Published: May 2015

Infection with the helminth Schistosoma mansoni results in hepatointestinal granulomatous inflammation mediated by CD4 T cells directed against parasite eggs. The severity of disease varies greatly in humans and mice; however, the genetic basis of such a heterogenous immune response remains poorly understood. Here we show that, despite their close genetic relationship, C57BL/10SnJ (B10) mice developed significantly more pronounced immunopathology and higher T helper 17 cell responses than C57BL/6J (B6) mice. Similarly, live egg‐stimulated B10‐derived dendritic cells (DCs) produced significantly more IL‐1β and IL‐23, resulting in higher IL‐17 production by CD4 T cells. Gene expression analysis disclosed a heightened proinflammatory cytokine profile together with a strikingly lower expression of Ym1 in B10 versus B6 mice, consistent with failure of B10 DCs to attain alternative activation. To genetically dissect the differential response, we developed and analyzed congenic mouse strains that capture major regions of allelic variation, and found that the level of inflammation was controlled by a relatively small number of genes in a locus mapping to chromosome 4 117–143 MB. Our study has thus identified novel genomic regions that regulate the severity of the schistosome infection by way of controlling the mode of DC activation and consequent CD4 T‐cell subset development.
Erosion of a high‐altitude, low‐relief area on the Korean Peninsula: implications for its development processes and evolution
Authors: Byun Jongmin , Heimsath Arjun M. , Seong Yeong Bae , Lee Soo Yong 
Published: May 2015

AbstractThe processes involved in the development of high‐altitude, low‐relief areas (HLAs) are still poorly understood. Although cosmogenic nuclides have provided insights into the evolution of HLAs interpreted as paleo‐surfaces, most studies focus on estimating how slowly they erode and thereby their relative stability. To understand actual development processes of HLAs, we applied several techniques of cosmogenic nuclides in the Daegwanryeong Plateau, a well‐known HLA in the Korean Peninsula. Our denudation data from strath terraces, riverine sediments, soils, and tors provide the following conclusions: (1) bedrock incision rate in the plateau (~127 m Myr−1) is controlled by the incision rate of the western part of the Korean Peninsula, and is similar to the catchment‐wide denudation rate of the plateau (~93 m Myr−1); (2) the soil production function we observed shows weak depth dependency that may result from highly weathered bedrock coupled with frequent frost action driven by alpine climate; (3) a discrepancy between the soil production and catchment‐wide denudation rates implies morphological disequilibrium in the plateau; (4) the tors once regarded as fossil landforms of the Tertiary do not reflect Tertiary processes; and (5) when compared with those of global paleo‐surfaces (<20 m Myr−1), our rapid denudation rates suggest that the plateau cannot have maintained its probable initial paleo landscape, and thus is not a paleo‐surface. Our data contribute to understanding the surface processes of actively eroding upland landscapes as well as call into question conventional interpretations of supposed paleo‐surfaces around the world. Copyright © 2015 John Wiley & Sons, Ltd.
The use of core‐shell high‐performance liquid chromatography column technology to improve biogenic amine quantification in wine
Authors: Berbegal Carmen , Pardo Isabel , Ferrer Sergi 
Published: May 2015

AbstractBACKGROUNDHPLC column technology has been improved, providing better resolution of closely eluting compounds, better analyte sensitivity, and shorter analysis times. The core‐shell technology columns offer a faster analysis through the use of shorter columns without compromising resolution. The aim of this work was to improve the methods for determination of biogenic amines (BAs) in wine using the new HPLC PFP core‐shell column technology.RESULTSTwo different elution programs were designed to quantify BAs with the core‐shell PFP column. Program I flow rate was 2 mL min−1. The total elution time was 10 min. In elution program II, the flow rate was 0.8 mL min−1 and the total elution time was 25 min. The two elution programs used with the core‐shell PFP HPLC column showed differences related mainly to the histamine peak. The chromatograms showed that when a temporary isocratic elution was added in the gradient (program II), the histamine peak was eluted later, causing its isolation, and therefore its quantification was easier.CONCLUSIONSCompared to the previous C18 HPLC column for the BAs determination in wine, the main advantage of the presented technique is the reduction of the run times and solvent volumes, and has a better sensitivity and selectivity as peaks are higher and sharper. © 2015 Society of Chemical Industry
(Anti)mutagenic and immunomodulatory properties of quercetin glycosides
Authors: Valentová Kateřina , Šíma Petr , Rybková Zuzana , Křížan Jiří , Malachová Kateřina , Křen Vladimír 
Published: May 2015

AbstractBACKGROUNDQuercetin‐3‐O‐β‐d‐glucopyranoside (isoquercitrin) and quercetin‐3‐O‐rutinoside (rutin) are common components of a normal human diet and are increasingly used in food supplements. Here their effect on mutagenesis and immunity is shown.RESULTSThe in vitro (anti)mutagenic potential was compared with that of quercetin using the Ames test in Salmonella typhimurium His− strains TA100, TA98 and TA102. Isoquercitrin only slightly increased the number of revertants, while rutin was totally non‐mutagenic. On the other hand, all compounds displayed dose‐dependent protective activity against H2O2‐ and tert‐butyl hydroperoxide‐induced oxidative damage to the TA102 strain and at 75 µmol L−1 inhibited H2O2/Fe2+‐induced formation of the open circular and linear forms of the DNA plasmid pBSIISK(−). In mice, none of the flavonols (0.86 µmol day−1, 34 days) induced harmful effects. In immunized animals, all compounds enhanced ex vivo B cell proliferation; quercetin stimulated lymphocyte basal proliferation and increased the number of IgM‐producing lymphocytes. Rutin promoted NK cytotoxic activity, supported T cells and enhanced gut epithelium renewal. No effect on IgG‐forming cells was found.CONCLUSIONIsoquercitrin displayed negligible and rutin no mutagenicity, but both showed significant antimutagenic and DNA‐protective effects against oxidative damage. In vivo, they supported the readiness of the immune system for specific humoral immune response. © 2015 Society of Chemical Industry