bluuebunny/crossref_metadata_2025_split huggingface dataset:
Marine animals significantly increase tundra N2O and CH4emissions in maritime Antarctica
Authors: Zhu Renbin , Liu Yashu , Xu Hua , Ma Dawei , Jiang Shan 
Published: December 2013

AbstractMost studies on greenhouse gas emissions from animals concentrated on domestic animals, with limited data available from wild animals. The number of marine animals is potentially large in coastal Antarctica. In this paper, N2O and CH4emissions were investigated from a penguin colony, a seal colony, a skua colony, the adjacent animal‐lacking tundra, and background tundra sites to test the effects of marine animals on their fluxes in maritime Antarctica. Extremely high N2O emissions occurred in the penguin puddles (mean 392 µg N2O m−2h−1) and seal wallows (mean 579 µg N2O m−2h−1). The N2O emissions from animal colony tundra (13–57 µg N2O m−2h−1) are much higher than those from the animal‐lacking tundra, whereas the background tundra showed negligible N2O fluxes. Penguin puddles and seal wallows were stronger CH4emitters than animal colony tundra soils, while animal‐lacking tundra soils were strong CH4sinks. Overall high N2O and CH4emissions were modulated by soil physical and chemical processes associated with marine animal activities: sufficient supply of the nutrients NH4+–N and NO3−–N, total nitrogen, and total organic carbon from marine animal excreta, animal tramp, and high soil water‐filled pore space. Laboratory incubation experiments further confirmed that penguin and seal colony soils produced much higher N2O and CH4emissions than animal‐lacking tundra soils. Our results indicate that marine animal colonies are the hot spots for N2O and CH4emissions in maritime Antarctica, and even at the global scale, and current climate warming will further increase their emissions.
Highly Enantioselective Synthesis of Chiral Tetrahydroquinolines and Tetrahydroisoquinolines by Ruthenium‐Catalyzed Asymmetric Hydrogenation in Ionic Liquid
Authors: Ding Zi‐Yuan , Wang Tianli , He Yan‐Mei , Chen Fei , Zhou Hai‐Feng , Fan Qing‐Hua , Guo Qingxiang , Chan Albert S. C. 
Published: December 2013

AbstractAsymmetric hydrogenation reactions of quinolines and 3,4‐dihydroisoquinolines using the chiral cationic ruthenium complex Ru(TsDPEN) [TsDPEN=N‐(p‐toluenesulfonyl)‐1,2‐diphenylethylenediamine] as catalyst in neat imidazolium ionic liquids have been investigated. The catalytic performance was influenced by the anion of the ionic liquids for both substrate classes. A range of 2‐alkyl‐substituted 1,2,3,4‐tetrahydroquinolines and 1‐alkyl‐substituted 1,2,3,4‐tetrahydroisoquinolines was obtained in high yields with up to >99% ee. Interestingly, the hydrogenation of quinoline derivatives bearing a carbonyl group was selective for the CN (quinoline) over the CO (ketone) bonds, while such a unique chemoselectivity was not observed in methanol. Furthermore, the ruthenium catalysts could be easily recycled at least 5 times in the asymmetric hydrogenation of 3,4‐dihydroisoquinoline by solvent extraction. To further facilitate the recovery of catalyst and reduce the use of organic solvent, a thin film of ionic liquid containing Ru(TsDPEN) was supported on silica gels. This supported ionic liquid‐phase catalyst was effective in the asymmetric hydrogenation of quinoline, and could be recycled at least 6 times by simple filtration.magnified image
Enantiomerenbestimmung chiraler Moleküle in Stoffgemischen mittels Breitband‐Mikrowellenspektroskopie
Authors: Shubert V. Alvin , Schmitz David , Patterson David , Doyle John M. , Schnell Melanie 
Published: December 2013

AbstractWir analysieren Enantiomeren‐ und Konformerengemische von Carvon mittels chiralitätsselektiver Breitband‐Mikrowellenspektroskopie. Dabei können wir zeigen, dass wir Enantiomere voneinander unterscheiden, Enantiomerenüberschüsse messen und absolute Konfigurationen bestimmen können. Unsere Methode verwendet Drei‐Wellen‐Mischung im Mikrowellenfrequenzbereich und ist für die Untersuchung von Stoffgemischen hervorragend geeignet – ein Vorteil gegenüber anderen Techniken. Im Unterschied zur konventionellen Mikrowellenspektroskopie verwenden wir auch die Phase des Molekülsignals. Diese Phase hängt von den Vorzeichen der Dipolmomentskomponenten der Moleküle ab und erlaubt die Bestimmung des Überschussenantiomers, wohingegen sich die Höhe des Überschusses über die Signalamplitude bestimmen lässt. In unseren Experimenten untersuchen wir zwei Carvon‐Konformere gleichzeitig und zeigen damit die Eignung der Methode für die Mischungsanalyse. Aus quantenchemischen Berechnungen und den gemessenen Phasen können wir zudem die absoluten Konfigurationen der Enantiomere bestimmen.
Biodegradable Gold Nanovesicles with an Ultrastrong Plasmonic Coupling Effect for Photoacoustic Imaging and Photothermal Therapy
Authors: Huang Peng , Lin Jing , Li Wanwan , Rong Pengfei , Wang Zhe , Wang Shouju , Wang Xiaoping , Sun Xiaolian , Aronova Maria , Niu Gang , Leapman Richard D. , Nie Zhihong , Chen Xiaoyuan 
Published: December 2013

AbstractThe hierarchical assembly of gold nanoparticles (GNPs) allows the localized surface plasmon resonance peaks to be engineered to the near‐infrared (NIR) region for enhanced photothermal therapy (PTT). Herein we report a novel theranostic platform based on biodegradable plasmonic gold nanovesicles for photoacoustic (PA) imaging and PTT. The disulfide bond at the terminus of a PEG‐b‐PCL block‐copolymer graft enables dense packing of GNPs during the assembly process and induces ultrastrong plasmonic coupling between adjacent GNPs. The strong NIR absorption induced by plasmon coupling and very high photothermal conversion efficiency (η=37 %) enable simultaneous thermal/PA imaging and enhanced PTT efficacy with improved clearance of the dissociated particles after the completion of PTT. The assembly of various nanocrystals with tailored optical, magnetic, and electronic properties into vesicle architectures opens new possibilities for the construction of multifunctional biodegradable platforms for biomedical applications.
New Insights into Acrylic Polymer Precipitation by Supercritical Fluids
Authors: Montes Antonio , Gordillo M. Dolores , Pereyra Clara , Martínez de la Ossa Enrique J. 
Published: December 2013

AbstractNanosystems based on polymers have attracted much attention due to the almost infinite diversity. In the past decades, the application of supercritical fluids for polymeric particle precipitation has been developed as an alternative to conventional processes. Here, precipitation of an acrylic copolymer was attempted by the rapid expansion of supercritical solutions (RESS) and successful by supercritical antisolvent (SAS) processes. In addition, the nanoparticles were characterized with different techniques. The polymer concentration, pressure, temperature, liquid solution flow rate and nozzle diameter effects were also evaluated with regard to particle size and the particle size distribution of this polymer.
Competitive Gold‐Activation Modes in Terminal Alkynes: An Experimental and Mechanistic Study
Authors: Gimeno Ana , Cuenca Ana B. , Suárez‐Pantiga Samuel , de Arellano Carmen Ramírez , Medio‐Simón Mercedes , Asensio Gregorio 
Published: December 2013

AbstractThe competition between π‐ and dual σ,π‐gold‐activation modes is revealed in the gold(I)‐catalyzed heterocyclization of 1‐(o‐ethynylaryl)urea. A noticeable effect of various ligands in gold complexes on the choice of these activation modes is described. The cationic [Au(IPr)]+ (IPr=2,6‐bis(diisopropylphenyl)imidazol‐2‐ylidene) complex cleanly promotes the π activation of terminal alkynes, whereas [Au(PtBu3)]+ favors intermediate σ,π species.In this experimental and mechanistic study, which includes kinetic and cross‐over experiments, several σ‐gold, σ,π‐gold, and other gold polynuclear reaction intermediates have been isolated and identified by NMR spectroscopy, X‐ray diffraction, or MALDI spectrometry. The ligand control in the simultaneous or alternative π‐ and σ,π‐activation modes is also supported by deuterium‐labeling experiments.
Maintenance strategies for wireless sensor networks: from a reactive to a proactive approach
Authors: Azzaz Skander , Saidane Leila Azouz 
Published: December 2013

ABSTRACTIn this paper, we have introduced three proactive maintenance strategies for static wireless sensor networks (WSNs) using a limited number of mobile maintainer robots: the centralised proactive maintenance strategy denoted by CPMS, the fixed distributed proactive maintenance strategy denoted by FDPMS and the adaptive distributed proactive maintenance strategy denoted by ADPMS. The proposed maintenance strategies are based on a simple energy dissipation analytical model to estimate the occurrence times of the expected sensor failures in the network. Once identified, the anticipated failures are replaced by the available robots before they happen. To select the appropriate maintainer robot for each expected failure, CPMS opts for a centralised scheduling method based on the genetic algorithm fundamentals. However, the distributed maintenance strategies (FDPMS and ADPMS) use two different WSN area partitioning methods to share the sensor maintenance tasks among the available robots. Simulation results have shown that CPMS gives the minimal network dysfunction time representing the interruption service time induced by the detected faulted nodes. However, due to its significant signalling cost, we have remarked that CPMS can be deployed only in small scale WSNs. In large‐scale ones, ADPMS has demonstrated its efficiency in terms of the network dysfunction time, the robot travelled distance and the introduced signalling cost. In particular cases, when sensor failures are uniformly distributed on the network map, FDPMS has given the best performances. Copyright © 2013 John Wiley & Sons, Ltd.
Sequential Tape Casting of Anode‐Supported Solid Oxide Fuel Cells
Authors: Menzler N. H. , Malzbender J. , Schoderböck P. , Kauert R. , Buchkremer H. P. 
Published: December 2013

AbstractA novel route was developed to fabricate anode‐supported solid oxide fuel cells with a high throughput and low manufacturing costs. In contrast to classical manufacturing routes, this novel route starts with the tape casting of the thin electrolyte followed by the tape casting of the anode and anode support. All three layers were cast green‐on‐green and finally sintered to yield a gas‐tight electrolyte. By carefully selecting the raw materials for all three layers, it is possible to manufacture near‐net‐shape half‐cells. The half‐cells were characterized with respect to thickness, microstructure, bending behavior, electrolyte gas leakage, shrinkage, electrolyte residual stresses, and mechanical strength. Finally, the cathode was screen‐printed and fired, and the full cell characteristics were obtained in single‐cell and stack tests. Additionally, a scale‐up to cell sizes of 200 × 200 mm2 was verified. Electrolyte and anode thickness were around 20 μm, and the support was cast to 300–500 μm. The helium leak rates were better than the necessary internal threshold, and the characteristic bending strength obtained was in the range of 150–200 MPa. The single‐cell tests revealed current densities of 1.0 A cm–2 at 700 mV and 800 °C (H2/air). A first stack test proved their stackability and operational functionality.
Anwendung der Diskrete‐Elemente‐Methode zur Vorhersage von Kräften bei der Bodenbearbeitung
Authors: Obermayr Martin , Vrettos Christos 
Published: December 2013

AbstractIn dieser Arbeit wird ein Simulationsmodell zur Vorhersage von Kräften bei der Bodenbearbeitung auf Basis der Diskrete‐Elemente‐Methode (DEM) vorgestellt. Es werden Interaktionsgesetze für drei verschiedene Bodenarten mit kohäsionslosem, kohäsivem und zementiertem Materialverhalten beschrieben. Die Scherfestigkeit des Bodens wird dabei mithilfe von simulierten Triaxialversuchen kalibriert. Andere Parameter des Modells werden durch Annahmen oder dimensionslose Kennzahlen festgelegt. Laborversuche an einem geraden Schild, der bei konstanter Geschwindigkeit durch das Bodenmaterial gezogen wird, zeigen eine gute Übereinstimmung mit der Simulation. Obwohl für diesen Fall auch Handformeln auf Basis des passiven Erddrucks geeignet sind, erlaubt es die Partikelsimulation darüber hinaus, auch komplexe Geometrien und Trajektorien auf die gleiche Weise zu simulieren. Dies wird durch eine Messung an einem Mobilbagger, der in gebrochenem Kies arbeitet, bestätigt.Application of the Discrete Element Method for the prediction of draft forces in soil. In this paper, a numerical model for the prediction of soil‐tool interaction forces, based on the Discrete Element Method (DEM) is presented. Three different types of particle‐interaction laws for cohesionless, cohesive, and cemented soil are described. The shear strength of the soil is being calibrated by the use of simulated triaxial compression tests. Other parameters of the model are either chosen by experience or by the use of dimensionless numbers. Laboratory tests on a straight cutting blade, which is moved through the sample soil at constant speed, show good agreement with the results of the simulation. For this case, empirical formulas based on the passive earth pressure could be applied. Beyond that, the particle simulation can also be applied in the same manner to more complex tool geometries and trajectories. This is verified by measurements on a wheeled excavator that is working in crushed gravel.
A protocol for rheological characterization of hydrogels for tissue engineering strategies
Authors: Zuidema Jonathan M. , Rivet Christopher J. , Gilbert Ryan J. , Morrison Faith A. 
Published: December 2013

AbstractHydrogels are studied extensively for many tissue engineering applications, and their mechanical properties influence both cellular and tissue compatibility. However, it is difficult to compare the mechanical properties of hydrogels between studies due to a lack of continuity between rheological protocols. This study outlines a straightforward protocol to accurately determine hydrogel equilibrium modulus and gelation time using a series of rheological tests. These protocols are applied to several hydrogel systems used within tissue engineering applications: agarose, collagen, fibrin, Matrigel™, and methylcellulose. The protocol is outlined in four steps: (1) Time sweep to determine the gelation time of the hydrogel. (2) Strain sweep to determine the linear‐viscoelastic region of the hydrogel with respect to strain. (3) Frequency sweep to determine the linear equilibrium modulus plateau of the hydrogel. (4) Time sweep with values obtained from strain and frequency sweeps to accurately report the equilibrium moduli and gelation time. Finally, the rheological characterization protocol was evaluated using a composite Matrigel™‐methylcellulose hydrogel blend whose mechanical properties were previously unknown. The protocol described herein provides a standardized approach for proper analysis of hydrogel rheological properties. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1063–1073, 2014.
Metabolic activity measured on PET/CT correlates with clinical outcomes in patients with limb and girdle sarcomas
Authors: Skamene Sonia R. , Rakheja Rajan , Dalhstrom Kristina R. , Roberge David , Nahal Ayoub , Charest Mathieu , Turcotte Robert , Hickeson Marc , Freeman Carolyn 
Published: December 2013

AbstractObjectiveTo explore the relationship between metabolic activity and outcome in patients with extremity sarcomas.MethodsBetween June 2004 and December 2011, 120 patients with newly diagnosed limb and girdle sarcomas underwent FDG‐PET/CT for disease staging prior to curative intent treatment. The maximum standardized uptake value (SUVmax) was measured for each primary tumor and correlated with outcome. Progression‐free survival and overall survival (OS) were analyzed using the Kaplan–Meier method.ResultsSoft‐tissue sarcomas were more frequent (68%) than bone (27%) or cartilage (5%) tumors. Median follow‐up was 33.2 months. 51% of patients progressed during the follow‐up interval and 38% died. SUVmax was dichotomized with a cut‐point of 10.3. Patients with SUVmax < 10.3 had better DFS and OS compared with patients with SUVmax ≥ 10.3 (P < 0.001 and P < 0.001, respectively [log‐rank test]). Multivariate analysis confirmed that even after adjusting for age, sex, site, tumor type (bone vs. soft‐tissue), grade, and stage; an SUVmax ≥ 10.3 correlated with a twofold risk of progression and 2.4 times greater risk of death (hazard ratio [HR] 2.0, 95% CI, 1.1–3.7, and HR, 2.4, 95% CI, 1.1–4.9).ConclusionSUVmax is an independent adverse prognostic factor for both progression and OS in patients with extremity sarcomas. J. Surg. Oncol. 2014 109:410–414. © 2013 Wiley Periodicals, Inc.
Axillary reverse mapping using fluorescence imaging is useful for identifying the risk group of postoperative lymphedema in breast cancer patients undergoing sentinel node biopsies
Authors: Sakurai Takashi , Endo Mariko , Shimizu Ken , Yoshimizu Nobunari , Nakajima Kenichirou , Nosaka Kaori , Dai Yuuko , Iwao Akiko , Jinnai Yuki 
Published: December 2013

BackgroundAxillary reverse mapping (ARM) is a novel technique for preserving the upper extremity lymphatic pathways during axillary lymph node surgery. However, there is no evidence of the usefulness of ARM for patients undergoing sentinel lymph node biopsy (SNB).MethodsBetween August 2009 and July 2012, 372 patients who underwent the SNB procedure for breast cancer were enrolled in this study. Using the indocyanine green fluorescence technique and indigocarmine blue dye method, we studied the relationship between the upper extremity lymphatic flow and breast sentinel node (SN). Our aim of this study was the probability of postoperative lymphedema with respect to whether the upper extremity lymphatics corresponded to the breast SN.ResultsAmong the 327 patients who underwent the SNB procedure, the upper extremity lymphatics drainage into the breast SN in 76 (23.2%; corresponding group), and only 5 patients in this group developed lymphedema. In contrast, none of the patients in the noncorresponding group developed lymphedema.ConclusionsARM during SN biopsy can identify the group of patients who are at high risk for developing lymphedema. More risk‐focused guidance should be used for these patients. J. Surg. Oncol. 2014 109:612–615. © 2013 The Authors. Surgical Oncology Published by Wiley Periodicals, Inc.
Solid‐phase microextraction with a graphene‐composite‐coated fiber coupled with GC for the determination of some halogenated aromatic hydrocarbons in water samples
Authors: Zhang Guijiang , Li Zhi , Zang Xiaohuan , Wang Chun , Wang Zhi 
Published: December 2013

In this work, a graphene composite was coated onto etched stainless‐steel wire through a sol–gel technique and it was used as a solid‐phase microextraction (SPME) fiber. The prepared fiber was characterized by SEM, which revealed that the fiber had a highly porous structure. The application of the fiber was evaluated through the headspace SPME of five halogenated aromatic hydrocarbons (chlorobenzene, bromobenzene, 1,3‐dichlorobenzene, 1,2‐dichlorobenzene, and 1,2,4‐trichlorobenzene) in water samples followed by GC with flame ionization detection. The main factors influencing the extraction efficiency, including headspace volume, extraction time, extraction temperature, stirring rate, ionic strength of sample solution, and desorption conditions, were studied and optimized. Under the optimum conditions, the linearity of the method ranged from 2.5 to 800.0 μg/L for 1,2,4‐trichlorobenzene and from 2.5 to 500.0 μg/L for chlorobenzene, bromobenzene, 1,3‐dichlorobenzene, and 1,2‐dichlorobenzene, with the correlation coefficients (r) ranging from 0.9962 to 0.9980, respectively. The LODs (S/N = 3) of the method for the analytes were in the range between 0.5 and 1.0 μg/L. The recoveries of the method for the analytes obtained for the spiked water samples at 50.0 and 250.0 μg/L were from 76.0 to 104.0%.
Direct Pyrolysis ‐ Mass Spectrometry Analysis of Thermal Degradation of Thio‐Click‐Modified Poly(2‐oxazoline)
Authors: Atilkan Nurcan , Schlaad Helmut , Nur Yusuf , Hacaloglu Jale 
Published: December 2013

Poly(2‐(3‐butenyl)‐2‐oxazoline)s (PBOX) with glucose‐S‐butyl (Glc) and perfluoroalkyl‐S‐butyl (F) side chains (three samples: Glc/F = 100/0, 0/100, and 88/12) are synthesized by ring‐opening polymerization of 2‐butenyl‐2‐oxazoline and thiol‐ene click photochemistry, and their thermal properties are analyzed by direct‐pyrolysis mass spectrometry. Significant changes in the thermal stability and thermal‐degradation products are observed depending on the structure of the side chain. The thermal degradation of PBOX‐Glc and PBOX‐F homopolymers starts with loss of side chains at relatively low temperatures and successive cleavage along the side and main chains follows. The stability of the glucose units of the PBOX‐Glc/F copolymer is significantly increased by the presence of perfluoroalkyl groups, attributable to OH···F hydrogen bonding interactions during pyrolysis.
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Evaluation and prognostic significance of ACAT1 as a marker of prostate cancer progression
Authors: Saraon Punit , Trudel Dominique , Kron Ken , Dmitromanolakis Apostolos , Trachtenberg John , Bapat Bharati , van der Kwast Theodorus , Jarvi Keith A. , Diamandis Eleftherios P. 
Published: December 2013

INTRODUCTIONProstate cancer is the second leading cause of cancer‐related death among men in North America. While a majority of prostate cancer cases remain indolent, subsets of patients develop aggressive cancers, which may lead to death. The current methods of detection include digital rectal examination and the serum PSA test. However, due to lack of specificity, neither of these approaches is able to accurately discriminate between indolent and aggressive cancer, which is why there is a need for additional prognostic factors. Previously, we identified enzymes of the ketogenic pathway, particularly ACAT1, to be elevated in aggressive prostate cancer.METHODSIn the current study, we assessed the diagnostic and prognostic potential of ACAT1 by analyzing its expression using immunohistochemistry on a tissue microarray consisting of 251 clinically localized prostate cancer patients who have undergone radical prostatectomy.RESULTSUsing quantitative digital imaging software, we found that ACAT1 expression was significantly greater in cancerous cores compared to adjacent benign cores (P < 0.0001), in Gleason score (GS) ≥8 cancers versus GS≤6 cancers (P < 0.0001), GS≥8 cancers versus GS7 cancers (P = 0.001), as well as pT3/pT4 versus pT2 cancers (P = 0.001). In addition, ACAT1 predicted biochemical recurrence in univariate (HR, 1.81, CI = 1.13–2.9, P = 0.0128), and multivariate models (HR, 1.69, CI = 1.01–2.81, P = 0.0431) including pre‐operative PSA level, Gleason score and pathological stage. In univariate time‐to‐recurrence analysis, ACAT1 expression predicted recurrence in ERG negative cases (P = 0.0025), whereas ERG positive cases did not display any differences.DISCUSSIONTaken together, these findings indicate that ACAT1 expression could serve as a potential prognostic marker in prostate cancer, specifically in differentiating indolent and aggressive forms of cancer. Prostate 74:372–380, 2014. © 2013 Wiley Periodicals, Inc.