bluuebunny/crossref_metadata_2025_split huggingface dataset:
Impacts of a mushy‐layer thermodynamic approach in global sea‐ice simulations using the CICE sea‐ice model
Authors: Turner Adrian K. , Hunke Elizabeth C. 
Published: January 2015

AbstractWe perform global simulations of the Los Alamos sea‐ice model, CICE, with a new thermodynamics component that has a fully prognostic, variable bulk salinity vertical profile based on mushy layer physics. The processes of gravity drainage, melt‐water flushing and snow‐ice formation are parameterized to allow the bulk salinity to evolve with time. We analyze the seasonal and spatial variation of sea‐ice bulk salinity, area, volume and thickness and compare these quantities to simulations using the previous thermodynamic component. Adjusting one of the gravity drainage parameters, we find good agreement between simulation results and fieldwork ice‐core observations of sea‐ice bulk salinity. As expected, bulk salinity is highest during periods of ice growth and lowest after periods of ice melt. In the northern hemisphere the new thermodynamics component produces thicker ice than the previous thermodynamics component. Of the nine major differences between the two models, differences in how salinities are calculated and how melt‐pond flushing is parameterized are the principal causes of this thickness difference. Thickness differences are smaller in the southern hemisphere than in the northern hemisphere since a greater fraction of ice melts, and differences cannot accumulate year‐on‐year. Model differences in how ice thickness changes and snow‐ice formation are calculated are the most important causes of the different thickness between the two thermodynamic components in the southern hemisphere. The melt‐pond area and volume are found to be highly sensitive to a parameter choice controlling drainage through macroscopic holes in the ice, in both hemispheres.
Process‐based assessment of an ensemble of climate projections for West Africa
Authors: James Rachel , Washington Richard , Jones Richard 
Published: January 2015

AbstractDetermining the level of confidence in regional climate model projections could be very useful for designing climate change adaptation, particularly for vulnerable regions. The majority of previous research to evaluate models has been based on the mean state, but for confidence in projections the plausibility of the mechanisms for change is just as, if not more, important. In this study we demonstrate a methodology for process‐based assessment of projections, whereby circulation changes accompanying future responses are examined and then compared to atmospheric dynamics during historical years in models and reanalyses. We apply this methodology to an ensemble of five global and regional model experiments and focus on West Africa, where these models project a strong drying trend. The analysis reveals that this drying is associated with anomalous subsidence in the upper atmosphere, and large warming of the Saharan heat low region, with potential feedback effects via the African easterly jet and West African monsoon. This mode occurs during dry years in the historical period, and dominates in the future experiments. However, the same mode is not found in dry years in reanalysis data, which casts doubt on the reasons for strong drying in these models. The regional models show a very similar response to their driving global models, and are therefore no more trustworthy in this case. This result underlines the importance of assessing model credibility on a case‐by‐case basis and implies that process‐based methodologies should be applied to other model projections before their outputs are used to inform decision making.
Validation of AIRS version 6 temperature profiles and surface‐based inversions over Antarctica using Concordiasi dropsonde data
Authors: Boylan Patrick , Wang Junhong , Cohn Stephen A. , Fetzer Eric , Maddy Eric S. , Wong Sun 
Published: January 2015

AbstractDuring the 2010 Concordiasi field experiment, 635 dropsondes were released from the lower stratosphere providing in situ atmospheric profiles from the release height (~60 hPa) to the surface over Antarctica. They provide a unique data set of high vertical resolution temperature profiles over the entire Antarctic continent and surrounding ocean. This study uses temperature profiles and derived surface‐based inversion (SBI) properties from the sonde data set to evaluate Atmospheric Infrared Sounder (AIRS) versions 5 (v5) and 6 (v6) temperature profiles. A total of 1486 matched pairs of profiles are available for analysis. The AIRS averaging kernel, representing the AIRS measurement sensitivity, is applied to the dropsonde profiles. The AIRS data are compared to kernel‐averaged dropsonde profiles and found, on average, to have a small cold bias (~0.5°C) (for v6) in the troposphere. AIRS v6 is improved over v5 with both profile‐averaged bias and root‐mean‐square errors reduced by over 25%. Compared to the kernel‐averaged dropsonde profiles, AIRS v6 accurately detects the existence of SBIs in 79% of the profiles and agrees on the inversion depth 79% of the time. AIRS correctly identifies SBIs in 59% of cases when compared to the full‐resolution sonde. AIRS systematically underestimates the SBI intensity. This is due to warmer reported AIRS surface air temperatures (Ta) than Ta measured with the dropsonde. Replacement of AIRS Ta with that measured by the dropsonde improves the agreement in both SBI detection and intensity. If AIRS Ta could be improved, AIRS has the potential to be a stand‐alone SBI detection tool over Antarctica.
Regions of significant influence on unforced global mean surface air temperature variability in climate models
Authors: Brown Patrick T. , Li Wenhong , Xie Shang‐Ping 
Published: January 2015

AbstractWe document the geographic regions where local variability is most associated with unforced global mean surface air temperature (GMT) variability in Coupled Model Intercomparison Project Phase 5 coupled global climate models (GCMs) at both the subdecadal and interdecadal timescales. For this purpose, Regions of Significant Influence on GMT are defined as locations that have a statistically significant correlation between local surface air temperature (SAT) and GMT (with a regression slope greater than 1), and where local SAT variation leads GMT variation in time. In both GCMs and observations, subdecadal timescale GMT variability is most associated with SAT variation over the eastern equatorial Pacific. At the interdecadal timescale, GMT variability is also linked with SAT variation over the Pacific in many GCMs, but the particular spatial patterns are GCM dependent, and several GCMs indicate a primary association between GMT and SAT over the Southern Ocean. We find that it is difficult to validate GCM behavior at the interdecadal timescale because the pattern derived from observations is highly depended on the method used to remove the forced variability from the record. The magnitude of observed GMT variability is near the ensemble median at the subdecadal timescale but well above the median at the interdecadal timescale. GCMs with a stronger subdecadal relationship between GMT and SAT over the Pacific tend to have more variable subdecadal GMT while GCMs with a stronger interdecadal relationship between GMT and SAT over parts of the Southern Ocean tend to have more variable GMT.
The rapid, living, anionic polymerization of 2‐vinylnaphthalene at ambient temperature: Characterization of an n‐butyllithium/tetrahydrofuran system in 1,2,3,4‐tetrahydronaphthalene
Authors: Natori Itaru , Natori Shizue , Ogino Kenji 
Published: January 2015

ABSTRACTWe report the first well‐controlled room temperature anionic polymerization of 2‐vinylnaphthalene (2‐VNP), using alkyllithium (RLi) initiators. The nucleophilicity and solubility of the RLi as well as that of the 2‐vinylnaphthalenyllithium (VNPLi) and poly(2‐vinylnaphthalenyl)lithium (PVNPLi) propagating species were found to be very important factors in this reaction. An initiator system composed of n‐butyllithium (n‐BuLi) with tetrahydrofuran (THF) in 1,2,3,4‐tetrahydronaphthalene (THN) was determined to be the most effective of the various systems examined. The n‐BuLi/THF complex initiates polymerization and the resulting VNPLi/THF and PVNPLi/THF complexes act as propagating species at room temperature. These species offer adequate nucleophilicity and stability without promoting side reactions. As a result, rapid anionic polymerization was achieved. Various poly(2‐VNP) products with well‐defined polymeric chain structures were synthesized by this process at room temperature. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41901.
Meta-analysis of the effect of postoperative in-hospital morbidity on long-term patient survival
Authors: Pucher P H , Aggarwal R , Qurashi M , Darzi A 
Published: January 2015

Abstract

Background
Major surgery is associated with high rates of postoperative complications, many of which are deemed preventable. It has been suggested that these complications not only present a risk to patients in the short term, but may also reduce long-term survival. The aim of this review was to examine the effects of postoperative complications on long-term survival.

Methods
MEDLINE, Web of Science and reference lists of relevant articles were searched up to July 2013. Studies assessing only procedure-specific, or technical failure-related, complications were excluded, as were studies of poor methodological quality. Meta-analysis was performed using a random-effects model. Risk of bias was assessed using funnel plots.

Results
Eighteen eligible studies were included, comprising results for 134 785 patients with an overall complication rate of 22·6 (range 10·6–69) per cent. The studies included operations for both benign and malignant disease. Median follow-up was 43 (range 28–96) months. Meta-analysis demonstrated reduced overall survival after any postoperative complication for ten studies with eligible data (20 755 patients), with a hazard ratio (HR) of 1·28 (95 per cent confidence interval 1·21 to 1·34). Similar results were found for overall survival following infectious complications: HR 1·92 (1·50 to 2·35). In analyses of disease-free survival the HR was 1·26 (1·10 to 1·42) for all postoperative complications and 1·55 (1·12 to 1·99) for infectious complications. Inclusion of poor-quality studies in a sensitivity analysis had no effect on the results.

Conclusion
Postoperative complications have a negative effect on long-term survival. This relationship appears to be stronger for infectious complications.
Knockdown of CTRP6 inhibits adipogenesis via lipogenic marker genes and Erk1/2 signalling pathway
Authors: Wu Wen‐jing , Mo De‐lin , Zhao Cun‐zhen , Zhao Chen , Chen Yao‐sheng , Pang Wei‐jun , Yang Gong‐she 
Published: January 2015

AbstractC1q/tumor necrosis factor‐related protein 6 (CTRP6), an adipose‐tissue secretory factor, plays an important role in inflammatory reaction and carcinogenesis. However, the biological function of CTRP6 in adipogenesis remains unclear. In this study, we examined the effects of CTRP6 knockdown on lipogenesis of 3T3‐L1 adipocytes. The results showed that after 3T3‐L1 adipocytes transfected with anti‐CTRP6 small interfering RNA (siRNA), not only levels of secreted CTRP6 protein in the culture medium but also the expression level of the CTRP6 protein in the 3T3‐L1 adipocytes was significantly reduced (P < 0.01). In addition, the number of lipid droplets in the adipocytes was reduced, as well as the OD values reflecting the fat content being significantly decreased (P < 0.01). Meanwhile the levels of adipogenic markers, including peroxisome proliferator activated receptor γ (PPARγ), CCAAT/enhancer‐binding protein α (C/EBPα), CCAAT/enhancer‐binding protein β (C/EBPβ) and adipocyte fatty acid‐binding protein 4 (aP2), were decreased after treatment with anti‐CTRP6 siRNA, whereas the expression of adipose triglyceride lipase (ATGL) and triacylglycerol hydrolase (TGH) were increased. Furthermore, after transfection, activity of phosphorylated Erk1/2 (p‐Erk1/2) was inhibited in the early stage of differentiation, but in terminal differentiation of adipocytes, its activity was activated. Taken together, the results indicate that knockdown of CTRP6 can inhibit adipogenesis of 3T3‐L1 adipocytes through lipogenic marker genes and Erk1/2 signaling pathway.
Controlling Two‐Step Multimode Switching of Dihydroazulene Photoswitches
Authors: Petersen Anne U. , Broman Søren L. , Olsen Stine T. , Hansen Anne S. , Du Lin , Kadziola Anders , Hansen Thorsten , Kjaergaard Henrik G. , Mikkelsen Kurt V. , Brøndsted Nielsen Mogens 
Published: January 2015

AbstractWe present the synthesis and switching studies of systems with two photochromic dihydroazulene (DHA) units connected by a phenylene bridge at either para or meta positions, which correspond to a linear or cross‐conjugated pathway between the photochromes. According to UV/Vis absorption and NMR spectroscopic measurements, the meta‐phenylene‐bridged DHA–DHA exhibited sequential light‐induced ring openings of the two DHA units to their corresponding vinylheptafulvenes (VHFs). Initially, the VHF–DHA species was generated, and, ultimately, after continued irradiation, the VHF–VHF species. Studies in different solvents and quantum chemical calculations indicate that the excitation of DHA–VHF is no longer a local DHA excitation but a charge‐transfer transition that involves the neighboring VHF unit. For the linearly conjugated para‐phenylene‐bridged dimer, electronic communication between the two units is so efficient that the photoactivity is reduced for both the DHA–DHA and DHA–VHF species, and DHA–DHA, DHA–VHF, and VHF–VHF were all present during irradiation. In all, by changing the bridging unit, we can control the degree of stepwise photoswitching.
Unsymmetrical Pyrene‐Fused Phthalocyanine Derivatives: Synthesis, Structure, and Properties
Authors: Pan Houhe , Chen Chao , Wang Kang , Li Wenjun , Jiang Jianzhuang 
Published: January 2015

AbstractNovel pyrene‐fused unsymmetrical phthalocyanine derivatives 2,3,9,10,16,17‐hexakis(2,6‐dimethylphenoxy)‐22,25‐diaza(2,7‐di‐tert‐butylpyrene)[4,5]phthalocyaninato zinc complex Zn[Pc(Pz‐pyrene)(OC8H9)6] (1) and 2,3,9,10‐tra(2,6‐dimethylphenoxy)‐15,18,22,25‐traza(2,7‐di‐tert‐butylpyrene)[4,5]phthalocyaninato zinc compound Zn[Pc(Pz‐pyrene)2(OC8H9)4] (2) were isolated for the first time. These unsymmetrical pyrene‐fused phthalocyanine derivatives have been characterized by a wide range of spectroscopic and electrochemical methods. In particular, the pyrene‐fused phthalocyanine structure was unambiguously revealed on the basis of single crystal X‐ray diffraction analysis of 1, representing the first structurally characterized phthalocyanine derivative fused with an aromatic moiety larger than benzene.
Convenient and Highly Efficient Routes to 2 H‐Chromene and 4‐Chromanone Derivatives: Iodine‐Promoted and p‐Toluenesulfonic Acid Catalyzed Cascade Cyclizations of Propynols
Authors: Qiu Yi‐Feng , Ye Yu‐Ying , Song Xian‐Rong , Zhu Xin‐Yu , Yang Fang , Song Bo , Wang Jia , Hua Hui‐Liang , He Yu‐Tao , Han Ya‐Ping , Liu Xue‐Yuan , Liang Yong‐Min 
Published: January 2015

AbstractA convenient strategy is presented for the easy preparation of a series of 2 H‐chromenes under mild conditions through iodocyclization of readily accessible propynols. In addition, various 4‐chromanones can be synthesized through a p‐toluenesulfonic acid catalyzed cascade cyclization with high efficiency (yields up to 99 %). Our developed reaction systems are proven to have good functional‐group applicability and can be scaled up to gram quantities in satisfactory yields. These systems also provide a new synthetic strategy for two types of important flavonoid skeleton without using costly and toxic metal catalysts. Additionally, the resulting halides could be further exploited in subsequent palladium‐catalyzed coupling reactions, so these compounds could act as potential intermediates for the construction of some valuable drug molecules.
Self‐Assembling Hydrogels Crosslinked Solely by Receptor–Ligand Interactions: Tunability, Rationalization of Physical Properties, and 3D Cell Culture
Authors: Thompson Michael S. , Tsurkan Mikhail V. , Chwalek Karolina , Bornhauser Martin , Schlierf Michael , Werner Carsten , Zhang Yixin 
Published: January 2015

AbstractWe report a novel, noncovalent hydrogel system crosslinked solely by receptor–ligand interactions between biotin and avidin. The simple hydrogel synthesis and functionalization together with the widespread use of biotinylated ligands in biosciences make this versatile system suitable for many applications. The gels possess a range of tunable physical properties, including stiffness, lifetime, and swelling. The erosion rates, unexpectedly fast compared to the kinetic parameters for biotin–avidin, are explored in terms of stretching tensions on the polymers, a concept well‐known on the single‐molecule level, but largely unexplored in supramolecular systems. As proof of utility, the gels were functionalized with different peptide sequences to control human mesenchymal stromal cell morphology in 3D culture.
Ökologische Bewertung von Produktionsprozessen in Mehrproduktbatchanlagen
Authors: Wesche Mandy , Häberl Michael , Kohnke Marco , Scholl Stephan 
Published: January 2015

AbstractFür die Gestaltung nachhaltiger Produktionsverfahren in allen Branchen der Prozessindustrie sind neben sozialen und ökonomischen auch ökologische Aspekte von entscheidender Bedeutung. Vorgestellt wird ein Ansatz auf Basis eines 3‐Ebenen‐Modells, der die Analyse von Produktionsprozessen in Mehrproduktanlagen im Hinblick auf Energie‐ und Ressourcenverbrauch verbunden mit ökologischen Betrachtungen ermöglicht sowie die Identifizierung und Quantifizierung von Verbesserungspotenzialen unterstützt. Der Ansatz ist modular aufgebaut und basiert auf einer Stoffstromnetzmodellierung der betrachteten Prozesse.
Novel Non‐Coplanar and Tertbutyl‐Substituted Polyimides: Solubility, Optical, Thermal and Dielectric Properties
Authors: Liu Chanjuan , Pei Xianglin , Huang Xiaohua , Wei Chun , Sun Xiaoyi 
Published: January 2015

AbstractA novel aromatic diamine monomer bearing tertbutyl and 4‐tertbutylphenyl groups, 3,3′‐ditertbutyl‐4,4′‐diaminodiphenyl‐4′′‐tertbutylphenylmethane (TADBP), was prepared and characterized. A series of non‐coplanar polyimides (PIs) were synthesized via a conventional one‐step polycondensation from TADBP and various aromatic dianhydrides including pyromellitic dianhydride (PMDA), 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA), 4,4′‐oxydiphthalic anhydride (OPDA), 3,3′,4,4′‐benzophenone tetracarboxylic dianhydride (BTDA) and 4,4′‐(hexafluoroisopropylidene)dipthalic anhydride (6FDA). All PIs exhibit excellent solubility in common organic solvents such as N,N‐dimethylformamide (DMF), N,N‐dimethylacetamide (DMAc), N‐methyl‐2‐pyrrolidone (NMP), dimethyl sulfoxide (DMSO), chloroform (CHCl3), tetrahydrofuran (THF), and so on. Furthermore, the obtained transparent, strong and flexible polyimide films present good thermal stability and outstanding optical properties. Their glass transition temperatures (Tgs) are in the range of 298 to 347°C, and 10% weight loss temperatures are in excess of 490°C with more than 53% char yield at 800°C in nitrogen. All the polyimides can be cast into transparent and flexible films with tensile strength of 80.5–101 MPa, elongation at break of 8.4%–10.5%, and Young's modulus of 2.3–2.8 GPa. Meanwhile, the PIs show the cutoff wavelengths of 302–356 nm, as well as low moisture absorption (0.30% –0.55%) and low dielectric constant (2.78–3.12 at 1 MHz).
Effect of Organo‐Modified Nanosepiolite on Fire Behaviors and Mechanical Performance of Polypropylene Composites
Authors: Zhang Junhao , de Juan Sergio , Esteban‐Cubillo Antonio , Santarén Julio , Wang De‐Yi 
Published: January 2015

AbstractThe objective of the study was to investigate the effect of the organo‐modified nanosepiolite (ONSep) on improving the fire safety of polypropylene (PP). The composites based on PP, flame retardant master batch (MB‐FR, 25 wt% PP+50 wt% decabromodiphenyl ether (DBDPE)+25% antimony trioxide (ATO)) and ONSep were prepared via melt blending. The results of the limiting oxygen index (LOI) and vertical burning rating (UL‐94) test indicated that PP/40 wt% MB composites had no rating with seriously dripping phenomenon, while the LOI value was only 22.5. However, as 4 wt% ONSep was added in PP/40 wt% MB composites, the composites achieved UL94 V‐0 rating and the LOI value was 24.3. In comparison, PP/50 wt% MB composites could not reach the V‐0 rating either. The TGA results revealed that the addition of ONSep enhanced the thermal stability of the PP/MB‐FR composites. The cone calorimeter results indicated that the heat release rate, average mass loss rate, smoke production rate and smoke temperature of the PP/40 wt% MB‐FR/4 wt% ONSep composites decreased in comparison with those of PP/40 wt% MB‐FR composites. Simultaneously, the Young modulus and impact strength were also much better improved with the increase of ONSep loading. Therefore, the synergistic flame retardancy of ONSep in PP/MB‐FR matrix significantly containing a halogen based flame retardant (DBDPE) significantly improved the fire safety and mechanical properties of the composites, and allowed to decrease the total amount of brominated fire retardants.
Prepivoting composite score statistics by weighted bootstrap iteration
Authors: Lunardon Nicola 
Published: January 2015

AbstractThe role played by the composite analogue of the log likelihood ratio in hypothesis testing and in setting confidence regions is not as prominent as it is in the canonical likelihood setting, since its asymptotic distribution depends on the unknown parameter. Approximate pivots based on the composite log likelihood ratio can be derived by using asymptotic arguments. However, the actual distribution of such pivots may differ considerably from the asymptotic reference, leading to tests, and confidence regions whose levels are distant from the nominal ones. The use of bootstrap rather than asymptotic distributions in the composite likelihood framework is explored. Prepivoted tests and confidence sets based on a suitable statistic turn out to be accurate and computationally appealing inferential tools.The Canadian Journal of Statistics43: 18–41; 2015 © 2015 Statistical Society of Canada
Elektrophile Substitutionsreaktionen an Aromaten verstehen – σ‐Komplexe als (experimentelle) Schlüsselstrukturen
Authors: Vorwerk Nora , Schmitt Catharina , Schween Michael 
Published: January 2015

AbstractElektrophile Substitutionsreaktionen sind der bei weitem wichtigste Reaktionstyp zur Funktionalisierung der wegen zahlreicher Alltags‐ und Technikbezüge so wichtigen Verbindungsklasse der Aromaten. Damit kommt ihnen auf jeden Fall in der universitären Lehrerbildung, aber auch im schulischen Unterricht auf Leistungskurs‐Niveau eine wichtige Rolle zu. Zudem bietet das Thema vielfältige Chancen zur Vernetzung mit anderen schulrelevanten Themen wie z. B. Farbstoffen und Farbigkeit. Diese Arbeit widmet sich der Erzeugung und dem Nachweis stabiler σ‐Komplexe, den Schlüsselstrukturen zum Verstehen des Reaktionsmechanismus′, mit schulischen Mitteln. Anhand ausgewählter Modellreaktionen wird experimentell und theoretisch ein Zusammenhang zwischen der vorhersagbaren Stabilität von Zwischenstufen und ihrer Bildungsgeschwindigkeit hergestellt.