bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigating the Influence of Interfacial Contact Properties on Open Circuit Voltages in Organic Photovoltaic Performance: Work Function Versus Selectivity
Authors: Ratcliff Erin L. , Garcia Andres , Paniagua Sergio A. , Cowan Sarah R. , Giordano Anthony J. , Ginley David S. , Marder Seth R. , Berry Joseph J. , Olson Dana C. 
Published: February 2013

AbstractThe role of work function and thermodynamic selectivity of hole collecting contacts on the origin of open circuit voltage (VOC) in bulk heterojunction organic photovoltaics is examined for poly(N‐9′‐heptadecanyl‐2,7‐carbazole‐alt‐5,5‐(4′,7′‐di‐2‐thienyl‐2′,1′,3′‐benzothiadiazole) (PCDTBT) and [6,6]‐phenyl‐C71 butyric acid methyl ester (PC71BM) solar cells. In the absence of a charge selective, electron blocking contact, systematic variation of the work function of the contact directly dictates the VOC, as defined by the energetic separation between the relative Fermi levels for holes and electrons, with little change in the observed dark saturation current, J0. Improving the charge selectivity of the contact through an increased barrier to electron injection from the fullerene in the blend into the hole contact results in a decreased reverse saturation current (decreased J0 and increased shunt resistance, RSH) and improved VOC. Based on these observations, we provide a set of contact design criteria for tuning the VOC in bulk heterojunction organic photovoltaics.
A mathematical basis for plant patterning derived from physico‐chemical phenomena
Authors: Beleyur Thejasvi , Abdul Kareem Valiya Kadavu , Shaji Anil , Prasad Kalika 
Published: February 2013

AbstractThe position of leaves and flowers along the stem axis generates a specific pattern, known as phyllotaxis. A growing body of evidence emerging from recent computational modeling and experimental studies suggests that regulators controlling phyllotaxis are chemical, e.g. the plant growth hormone auxin and its dynamic accumulation pattern by polar auxin transport, and physical, e.g. mechanical properties of the cell. Here we present comprehensive views on how chemical and physical properties of cells regulate the pattern of leaf initiation. We further compare different computational modeling studies to understand their scope in reproducing the observed patterns. Despite a plethora of experimental studies on phyllotaxis, understanding of molecular mechanisms of pattern initiation in plants remains fragmentary. Live imaging of growth dynamics and physicochemical properties at the shoot apex of mutants displaying stable changes from one pattern to another should provide mechanistic insights into organ initiation patterns.Editor's suggested further reading in BioEssays Computer simulation: The imaginary friend of auxin transport biology Abstract
Extended Sediment Quality Rating for Trace Elements in Urban Waters – Case Study Klinke, Germany
Authors: von Tümpling Wolf , Scheibe Norbert , Einax Jürgen Werner 
Published: February 2013

AbstractThe European Water Framework Directive (WFD) commits European Union member states to achieving good ecological status in all water bodies by 2015. For sediments the definition of good chemical status is based on numerical sediment quality guidelines. The aqua regia fraction is thus used for the evaluation of heavy metal concentrations in sediments. The chemical constituents in sediments responsible for mobility and toxicity are not considered generally. This article presents the combining of the sequential BCR procedure, for determining the chemical species of relevant elements, with the geoaccumulation index principle a numerical classification method for sediment quality guidelines. Using the BCR method it can be demonstrated that changes in element speciation can lead to more highly mobile species of trace elements which may affect the hazardous potential of sediments despite the “good chemical status” classification for aqua regia digestions. The Klinke stream is an urban surface water body located in Magdeburg, the state capital of Saxony‐Anhalt, Germany. Using this stream as an example it is shown that this additional information helps to describe the dynamics and discharge of the trace elements Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Rb, Sr, Mo, Pd, Cd, Sb, Ba, Pb, Bi, and U into the Elbe River from urban water bodies.
Feasibility of Solid‐State Fermentation Using Spent Fungi‐Substrate in the Biodegradation of PAHs
Authors: Rosales Emilio , Pazos Marta , Ángeles Sanromán M. 
Published: February 2013

AbstractThe ability of Trametes versicolor and Pleurotus ostreatus to grow on agroindustrial wastes, such as orange peels, and to degrade model polycyclic aromatic hydrocarbons (PAHs) in solid‐state fermentation (SSF) was evaluated. Best results in laccase production were obtained with T. versicolor cultures (3000 U L−1), however, P. ostreatus (2700 U L−1) showed higher ability to degrade the tested PAHs phenanthrene (PHE) and pyrene (PYR). Moreover, orange peels can be used as biofertilizer and the oxidative ability of the spent fungus and substrate obtained in SSF can be used in the remediation of polluted soil. The results obtained confirm this hypothesis. Thus, the decontamination achieved in soils polluted with PYR was around 43% (after 30 days) by addition of spent fungus and substrate from SSF.
Determination of cocaine, cocaine metabolites and cannabinoids in single hairs by MALDI Fourier transform mass spectrometry – preliminary results
Authors: Musshoff Frank , Arrey Tabiwang , Strupat Kerstin 
Published: February 2013

In a preliminary test, four single hairs of a drug abuser were analyzed for the presence of drugs by MALDI Fourier transform mass spectrometry (MALDI‐FTMS). Washed hair strains were directly fixed on a sample plate using pressure stable, double‐sided adhesive tape; α‐cyano‐4‐hydroxycinnamic acid matrix was manually spotted onto the hair strains. FTMS full scans were obtained moving from the hair root region towards the hair tip.Cocaine (accurate m/z ratio 304.15433) was identified mostly from the root of the hair and then later again towards the hair tip. This was confirmed by analysis of a second hair. Additionally cocaine metabolites with m/z ratio 290.13868 (benzoylecgonine), and m/z 318.16998 (cocaethylene) were detected for plausibility control. Using the MALDI technique, time‐related information was obtained concerning the behavioural pattern of the consumer with high resolution compared to conventional procedures. However, in two hairs of the same individual which were analyzed under the same conditions, negative results were achieved.These preliminary results confirm the applicability of MALDI‐MS for the determination of drugs and pharmaceuticals in hair samples being useful in forensic toxicology. The high chronological resolution allows an enhanced interpretation concerning the periods of drug administration. However, the negative results with two negative hairs have also demonstrated that hair analysis of single hairs can lead to misinterpretation. Different growth rates have to be considered, and particularly the phenomenon of different growth phases (anagen, catagen, telogen) require attention. Copyright © 2013 John Wiley & Sons, Ltd.
Asymmetric 1,4‐Michael Addition Reactions Catalyzed by a Cinchona Alkaloid Derived Primary Amine: A Theoretical Investigation of the Reaction Mechanism and Enantioselectivity
Authors: Su Zhishan , Lee Hai Whang , Kim Chan Kyung 
Published: February 2013

AbstractThe mechanism and enantioselectivity of the asymmetric 1,4‐Michael addition of malononitrile to unsaturated aryl ketones catalyzed by a cinchona alkaloid derived primary amine have been investigated by DFT and ONIOM methods. The calculations indicated that three continuous stages are involved in the overall reaction: 1) The formation of a (ket)iminium intermediate, 2) an addition reaction between the iminium and malononitrile, and 3 ) hydrolysis and regeneration of the catalyst. The proton from an acidic additive plays an important role in the formation of the key ketiminium ion intermediate in which the protonated tertiary amine of the alkaloid not only activates the carbonyl substrate through hydrogen bonding, but also facilitates the condensation of the primary amine catalyst by participating in the formation of water molecules. The calculations also indicated that steric interactions between the aromatic substituent, the quinoline ring, and the alkene moiety of the unsaturated ketone force the key ketiminium ion intermediate to adopt a preferred conformation to achieve more accessibleRe‐face attack of the substrate. These results are in good agreement with experimental observations.
The Fe‐Catalysed Phosphono‐Allylation of Activated Olefins
Authors: Rommel Susanne , Dieskau André P. , Plietker Bernd 
Published: February 2013

AbstractPhosphonates are useful building blocks for organic synthesis, and are also bioactive compounds. Traditionally, they are prepared by nucleophilic substitution under thermal conditions. The preparation of more densely functionalized phosphonates is still a synthetic challenge. In this paper, we present a convenient one‐pot three‐component phosphono‐allylation of activated olefins to give phosphonates bearing a variety of functional groups.
Modeling and simulation of three‐dimensional extrusion swelling of viscoelastic fluids with PTT, Giesekus and FENE‐P constitutive models
Authors: Mu Yue , Zhao Guoqun , Chen Anbiao , Wu Xianghong 
Published: February 2013

SUMMARYThe investigation of the extrusion swelling mechanism of viscoelastic fluids has both scientific and industrial interest. However, it has been traditionally difficult to afford theoretical and experimental researches to this problem. The numerical methodology based on the penalty finite element method with a decoupled algorithm is presented in the study to simulate three‐dimensional extrusion swelling of viscoelastic fluids flowing through out of a circular die. The rheological responses of viscoelastic fluids are described by using three kinds of differential constitutive models including the Phan‐Thien Tanner model, the Giesekus model, and the finite extensible nonlinear elastic dumbbell with a Peterlin closure approximation model. A streamface‐streamline method is introduced to adjust the swelling free surface. The calculation stability is improved by using the discrete elastic‐viscous split stress algorithm with the inconsistent streamline‐upwind scheme. The essential flow characteristics of viscoelastic fluids are predicted by using the proposed numerical method, and the mechanism of swelling phenomenon is further discussed.Copyright © 2013 John Wiley & Sons, Ltd.
Io's volcanism controls Jupiter's radio emissions
Authors: Yoneda M. , Tsuchiya F. , Misawa H. , Bonfond B. , Tao C. , Kagitani M. , Okano S. 
Published: February 2013

AbstractJupiter's sodium nebula showed an enhancement in late May through the beginning of June 2007. This means Io's volcanic activity and the magnetosphere's plasma content increased during this period. On the other hand, Jupiter's radio emission called HOM became quiet after the sodium nebula enhancement. The HOM emission is considered to be related to the activity of aurorae on Jupiter. These observation results therefore suggest that the increase in plasma supply from Io into Jupiter's magnetosphere weakens its field‐aligned current, which generates the radio emissions and aurorae on Jupiter. By comparing our observation results to recent model and observation results, we add supporting evidence to the possibility that Io's volcanism controls Jupiter's magnetospheric activity.
Estimation of 2006 Northern Hemisphere contrail coverage using MODIS data
Authors: Duda David P. , Minnis Patrick , Khlopenkov Konstantin , Chee Thad L. , Boeke Robyn 
Published: February 2013

AbstractA modified automated contrail detection algorithm (CDA) using five infrared channels available from the Moderate Resolution Imaging Spectrometer onboard the Aqua satellite is used to determine linear contrail coverage over the Northern Hemisphere during 2006. Commercial aircraft flight data are employed to filter false contrail detections by the CDA. The Northern Hemisphere annual mean linear contrail coverage ranges from 0.07% to 0.40% for three different CDA sensitivities. Based on visual analyses, the medium sensitivity CDA provides the best estimate of linear contrail coverage, which averages 0.13%. If scaled to the Southern Hemisphere, the global mean coverage would be 0.07%. Coverage is greatest during winter and least during the summer with maximum coverage over the North Atlantic. Less coverage is observed over heavy European and American traffic areas, likely as a result of difficulties in detecting linear contrails that overlap with each other and with older contrail cirrus. These results are valuable for evaluating the representation of contrails and contrail cirrus within global climate models and for retrieving contrail optical properties and radiative forcing.
Spatial relationship between lightning narrow bipolar events and parent thunderstorms as revealed by phased array radar
Authors: Wu Ting , Takayanagi Yuji , Yoshida Satoru , Funaki Tsuyoshi , Ushio Tomoo , Kawasaki Zen 
Published: February 2013

AbstractPhased array radar with unprecedented high temporal and spatial resolution is used for the first time to analyze structures of thunderstorms producing lightning narrow bipolar events (NBEs). Locations of NBEs generally correspond well with the deepest convection, but in some thunderstorms extending higher than 15 km, positive NBEs cluster around, rather than right at the center of the core of deep convection. Negative NBEs are generally higher than positive NBEs and are usually produced at the cloud top of the thunderstorm. Positive NBEs, on the other hand, are always located well inside the thundercloud. It seems that negative NBEs can only be produced in very vigorous thunderstorms with cloud tops higher than about 14 km. Numerous thunderstorms with lower height produce few negative NBEs, indicating a height threshold for NBE production. On the basis of these findings, it becomes very convenient and accurate to monitor severe thunderstorms with negative NBEs.
Puzzling over the dynamics of the Lofoten Basin ‐ a sub‐Arctic hot spot of ocean variability
Authors: Volkov Denis L. , Belonenko Tatyana V. , Foux Victor R. 
Published: February 2013

AbstractA sub‐Arctic “hot spot” of intense synoptic‐scale variability is observed in the Lofoten Basin (LB) of the Norwegian Sea. Using ERS‐1/2 and Envisat satellite altimetry measurements, we discover a cyclonic propagation of the synoptic‐scale sea surface height anomalies around the center of the LB. Surface drifter trajectories do not reveal an associated coherent near‐surface cyclonic flow suggesting that the propagating signals have a wavelike nature. We identify a dipole and a quadrupole wave modes rotating around the center of the LB, obtain analytic dispersion relations for these modes, and demonstrate that the observed propagation is a manifestation of topographic Rossby waves. Most of the observed waves have a wavelength of about 500 km and phase speeds ranging from 2 to 10 km/day. We show that these waves are largely responsible for the localization and amplification of sea surface height variability in the center of the LB.
Lateral entorhinal cortex is critical for novel object‐context recognition
Authors: Wilson David I.G. , Langston Rosamund F. , Schlesiger Magdalene I. , Wagner Monica , Watanabe Sakurako , Ainge James A. 
Published: February 2013

AbstractEpisodic memory incorporates information about specific events or occasions including spatial locations and the contextual features of the environment in which the event took place. It has been modeled in rats using spontaneous exploration of novel configurations of objects, their locations, and the contexts in which they are presented. While we have a detailed understanding of how spatial location is processed in the brain relatively little is known about where the nonspatial contextual components of episodic memory are processed. Initial experiments measured c‐fos expression during an object‐context recognition (OCR) task to examine which networks within the brain process contextual features of an event. Increased c‐fos expression was found in the lateral entorhinal cortex (LEC; a major hippocampal afferent) during OCR relative to control conditions. In a subsequent experiment it was demonstrated that rats with lesions of LEC were unable to recognize object‐context associations yet showed normal object recognition and normal context recognition. These data suggest that contextual features of the environment are integrated with object identity in LEC and demonstrate that recognition of such object‐context associations requires the LEC. This is consistent with the suggestion that contextual features of an event are processed in LEC and that this information is combined with spatial information from medial entorhinal cortex to form episodic memory in the hippocampus. © 2013 Wiley Periodicals, Inc.
Constructions of Nested Orthogonal Arrays
Authors: Wang Kun , Li Yang 
Published: February 2013

AbstractA symmetric nested orthogonal array, denoted by NOA, is an OA which contains an OA as a subarray, where . Nested orthogonal arrays are useful in designing an experimental setup consisting of two experiments, the expensive one of higher accuracy being nested in a relatively less expensive one of lower accuracy. In this paper, some combinatorial constructions of nested orthogonal arrays are provided. By employing these constructions, the existence spectrum of NOA is completely determined.
Oncogenic cooperation between PI3K/Akt signaling and transcription factor Runx2 promotes the invasive properties of metastatic breast cancer cells
Authors: Pande Sandhya , Browne Gillian , Padmanabhan Srivatsan , Zaidi Sayyed K. , Lian Jane B. , van Wijnen Andre J. , Stein Janet L. , Stein Gary S. 
Published: February 2013

AbstractThe serine/threonine kinase Akt/PKB promotes cancer cell growth and invasion through several downstream targets. Identification of novel substrates may provide new avenues for therapeutic intervention. Our study shows that Akt phosphorylates the cancer‐related transcription factor Runx2 resulting in stimulated DNA binding of the purified recombinant protein in vitro. Pharmacological inhibition of the PI3K/Akt pathway in breast cancer cells reduces DNA‐binding activity of Runx2 with concomitant reduction in the expression of metastasis‐related Runx2 target genes. Akt phosphorylates Runx2 at three critical residues within the runt DNA‐binding domain to enhance its in vivo genomic interactions with a target gene promoter, MMP13. Mutation of these three phosphorylation sites reduces Runx2 DNA‐binding activity. However, Akt signaling does not appear to interefere with CBFβ‐Runx2 interactions. Consequently, expression of multiple metastasis‐related genes is decreased and Runx2‐mediated cell invasion is supressed. Thus, our work identifies Runx2 as a novel and important downstream mediator of the PI3K/Akt pathway that is linked to metastatic properties of breast cancer cells. J. Cell. Physiol. 228: 1784–1792, 2013. © 2013 Wiley Periodicals, Inc.
Buried soil organic inclusions in non‐sorted circles fields in northern Sweden: Age and Paleoclimatic context
Authors: Becher Marina , Olid Carolina , Klaminder Jonatan 
Published: February 2013

AbstractAlthough burial of surface organic soil horizons into deeper mineral soil layers helps drive the long‐term buildup of carbon in arctic soils, when and why buried horizons formed as result of cryoturbation in northern Sweden remain unclear. In this study, we used 14C and 210Pb dating to assess when organic matter was buried within non‐sorted circles fields near Abisko in northern Sweden. In addition, we used aerial photos from 1959 and 2008 to detect eventual trends in cryogenic activities during this period. We found that organic matter from former organic horizons (stratigraphically intact or partly fragmented) corresponds to three major periods: 0–100 A.D., 900–1250 A.D., and 1650–1950 A.D. The latter two periods were indicated by several dated samples, while the extent of the oldest period is more uncertainty (indicated by only one sample). The aerial photos suggest a net overgrowth by shrub vegetation of previously exposed mineral soil surfaces since 1959. This overgrowth trend was seen in most of the studied fields (92 out of 137 analyzed fields), indicating that the cryogenic activity has mainly decreased in studied non‐sorted circles fields since the 1950s. This latter interpretation is also supported by the absence of buried organic layers formed during the last decades. We suggest that the organic matter was buried during the transition from longer cold periods to warmer conditions. We believe these climatic shifts could have triggered regional scale burial of soil organic matter and thus affected how these soils sequestered carbon.
Subcompartmentalization of extracellular extravascular space (EES) into permeability and leaky space with local arterial input function (AIF) results in improved discrimination between high‐ and low‐grade glioma using dynamic contrast‐enhanced (DCE) MRI
Authors: Sahoo Prativa , Rathore Ram K.S. , Awasthi Rishi , Roy Bhaswati , Verma Sanjay , Rathore Divya , Behari Sanjay , Husain Mazhar , Husain Nuzhat , Pandey Chandra M. , Mohakud Sudipta , Gupta Rakesh K. 
Published: February 2013

Purpose:To modify the generalized tracer kinetic model (GTKM) by introducing an additional tissue uptake leakage compartment in extracellular extravascular space (LTKM). In addition, an implicit determination of voxel‐wise local arterial input function (AIF) Cp(t) was performed to see whether these changes help in better discrimination between low‐ and high‐grade glioma using dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI).Materials and Methods:The modified model (LTKM) was explored and fitted to the concentration–time curve C(t) of each voxel, in which the local AIF Cp(t) could be estimated by a time invariant convolution approximation based on a separately measured global AIF Ca(t). A comparative study of tracer kinetic analysis was performed on 184 glioma patients using DCE‐MRI data on 1.5T and 3T MRI systems.Results:The LTKM analysis provided more accurate pharmacokinetic parameters as evidenced by their relative constancy with respect to the length of concentration–time curve used. In addition, LTKM with local AIF resulted in improved discrimination between low‐grade and high‐grade gliomas.Conclusion:LTKM with local AIF provides more accurate estimation of physiological parameters and improves discrimination between low‐grade and high‐grade gliomas as compared with GTKM. J. Magn. Reson. Imaging 2013;38:677–688. © 2013 Wiley Periodicals, Inc.