bluuebunny/crossref_metadata_2025_split huggingface dataset:
Beyond leaf color: Comparing camera‐based phenological metrics with leaf biochemical, biophysical, and spectral properties throughout the growing season of a temperate deciduous forest
Authors: Yang Xi , Tang Jianwu , Mustard John F. 
Published: January 2014

AbstractPlant phenology, a sensitive indicator of climate change, influences vegetation‐atmosphere interactions by changing the carbon and water cycles from local to global scales. Camera‐based phenological observations of the color changes of the vegetation canopy throughout the growing season have become popular in recent years. However, the linkages between camera phenological metrics and leaf biochemical, biophysical, and spectral properties are elusive. We measured key leaf properties including chlorophyll concentration and leaf reflectance on a weekly basis from June to November 2011 in a white oak forest on the island of Martha's Vineyard, Massachusetts, USA. Concurrently, we used a digital camera to automatically acquire daily pictures of the tree canopies. We found that there was a mismatch between the camera‐based phenological metric for the canopy greenness (green chromatic coordinate, gcc) and the total chlorophyll and carotenoids concentration and leaf mass per area during late spring/early summer. The seasonal peak of gcc is approximately 20 days earlier than the peak of the total chlorophyll concentration. During the fall, both canopy and leaf redness were significantly correlated with the vegetation index for anthocyanin concentration, opening a new window to quantify vegetation senescence remotely. Satellite‐ and camera‐based vegetation indices agreed well, suggesting that camera‐based observations can be used as the ground validation for satellites. Using the high‐temporal resolution dataset of leaf biochemical, biophysical, and spectral properties, our results show the strengths and potential uncertainties to use canopy color as the proxy of ecosystem functioning.
Predicting Alzheimer disease with β‐amyloid imaging: Results from the Australian imaging, biomarkers, and lifestyle study of ageing
Authors: Rowe Christopher C. , Bourgeat Pierrick , Ellis Kathryn A. , Brown Belinda , Lim Yen Ying , Mulligan Rachel , Jones Gareth , Maruff Paul , Woodward Michael , Price Roger , Robins Peter , Tochon‐Danguy Henri , O'Keefe Graeme , Pike Kerryn E. , Yates Paul , Szoeke Cassandra , Salvado Olivier , Macaulay S. Lance , O'Meara Timothy , Head Richard , Cobiac Lynne , Savage Greg , Martins Ralph , Masters Colin L. , Ames David , Villemagne Victor L. 
Published: January 2014

ObjectiveBiomarkers for Alzheimer disease (AD) can detect the disease pathology in asymptomatic subjects and individuals with mild cognitive impairment (MCI), but their cognitive prognosis remains uncertain. We aimed to determine the prognostic value of β‐amyloid imaging, alone and in combination with memory performance, hippocampal atrophy, and apolipoprotein E ε4 status in nondemented, older individuals.MethodsA total of 183 healthy individuals (age = 72.0 ± 7.26 years) and 87 participants with MCI (age = 73.7 ± 8.27) in the Australian Imaging, Biomarkers, and Lifestyle study of ageing were studied. Clinical reclassification was performed after 3 years, blind to biomarker findings. β‐Amyloid imaging was considered positive if the 11C‐Pittsburgh compound B cortical to reference ratio was ≥1.5.ResultsThirteen percent of healthy persons progressed (15 to MCI, 8 to dementia), and 59% of the MCI cohort progressed to probable AD. Multivariate analysis showed β‐amyloid imaging as the single variable most strongly associated with progression. Of combinations, subtle memory impairment (Z score = −0.5 to −1.5) with a positive amyloid scan was most strongly associated with progression in healthy individuals (odds ratio [OR] = 16, 95% confidence interval [CI] = 3.7–68; positive predictive value [PPV] = 50%, 95% CI = 19–81; negative predictive value [NPV] = 94%, 95% CI = 88–98). Almost all amnestic MCI subjects (Z score ≤ −1.5) with a positive amyloid scan developed AD (OR = ∞; PPV = 86%, 95% CI = 72–95; NPV = 100%, 95% CI = 80–100). Hippocampal atrophy and ε4 status did not add further predictive value.InterpretationSubtle memory impairment with a positive β‐amyloid scan identifies healthy individuals at high risk for MCI or AD. Clearly amnestic patients with a positive amyloid scan have prodromal AD and a poor prognosis for dementia within 3 years. Ann Neurol 2013;74:905–913
Multivalente synthetische Glycopeptid‐Lipopeptid‐Antitumorvakzine: Auswirkung des Cluster‐Effekts auf das Abtöten von Tumorzellen
Authors: Cai Hui , Sun Zhan‐Yi , Chen Mei‐Sha , Zhao Yu‐Fen , Kunz Horst , Li Yan‐Mei 
Published: January 2014

AbstractMultivalente synthetische Vakzine wurden durch Festphasensynthese von tumorassoziierten MUC1‐Glycopeptidantigenen und deren Kupplung an ein Pam3Cys‐Lipopeptid durch Klick‐Reaktion gewonnen. Diese Vakzine lösen in Mäusen Immunreaktionen aus, ohne dass externe Adjuvantien angewendet werden. Die vier MUC1‐Sialyl‐TN‐Antigene enthaltende Vakzine zeigte einen signifikanten Cluster‐Effekt. Sie induzierte in Mäusen vorwiegend IgG2a‐Antikörper, die an MCF‐7‐Brusttumorzellen binden und diese Tumorzellen durch Aktivierung des Complement‐abhängigen Cytotoxizitätskomplexes (CDC) abtöten.
Polymerization of Ethylene by Silica‐Supported Dinuclear CrIII Sites through an Initiation Step Involving CH Bond Activation
Authors: Conley Matthew P. , Delley Murielle F. , Siddiqi Georges , Lapadula Giuseppe , Norsic Sébastien , Monteil Vincent , Safonova Olga V. , Copéret Christophe 
Published: January 2014

AbstractThe insertion of an olefin into a preformed metal–carbon bond is a common mechanism for transition‐metal‐catalyzed olefin polymerization. However, in one important industrial catalyst, the Phillips catalyst, a metal–carbon bond is not present in the precatalyst. The Phillips catalyst, CrO3 dispersed on silica, polymerizes ethylene without an activator. Despite 60 years of intensive research, the active sites and the way the first CrC bond is formed remain unknown. We synthesized well‐defined dinuclear CrII and CrIII sites on silica. Whereas the CrII material was a poor polymerization catalyst, the CrIII material was active. Poisoning studies showed that about 65 % of the CrIII sites were active, a far higher proportion than typically observed for the Phillips catalyst. Examination of the spent catalyst and isotope labeling experiments showed the formation of a Si–(μ‐OH)–CrIII species, consistent with an initiation mechanism involving the heterolytic activation of ethylene at CrIIIO bonds.
Block copolymers for protein ordering
Authors: Malmström Jenny , Travas‐Sejdic Jadranka 
Published: January 2014

ABSTRACTLarge scale production of sub‐micrometer features aids vital understanding of the interactions present at that scale in the biological world as well as the interactions with artificial surfaces. Considerable research efforts have been put into the study and control of block copolymer self‐assembly, both in bulk phase and as thin films. Well‐ordered block copolymer films can be used for pattern transfer through etching or evaporation and have also been explored as templates for directed nanoparticle assembly and as hosts for proteins. This review is focused on the emerging area of using block copolymer films for the creation of ordered arrays of protein or peptides. The work done in the field is reviewed and focus is being put on how the systems have been characterized as this is an inherent difficulty of such systems. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40360.
Gas Sorption Studies on a Microporous Coordination Polymer Assembled from 2D Grid Layers by Strong π–π Interactions
Authors: Lv Xiaoxia , Li Liangjun , Sun Xiaoming , Zhang Hongyu , Cai Jinjun , Wang Chao , Tang Sifu , Zhao Xuebo 
Published: January 2014

AbstractThe microporous coordination polymer [Co(H2L)(bipy)0.5]⋅2 H2O (1, bipy=4,4′‐bipyridine) was synthesized on the basis of the V‐shaped flexible diphosphonate ligand (2,4,6‐trimethyl‐1,3‐phenylene)bis(methylene)diphosphonic acid (H4L) and the auxiliary bipy ligand under hydrothermal conditions. The structure of this compound was characterized by single‐crystal X‐ray diffraction. By joining the diphosphonate ligands and bipy through tetrahedral [CoO3N] clusters, a 2D square grid layered network was formed. Further stacking of these layers on the basis of π–π interactions resulted in a pseudo‐3D microporous network with 1D channels running through the a axis. Gas sorption studies for CO2, H2, CH4, N2, and O2 on this coordination polymer were performed, and the results revealed interesting dynamic and hysteresis sorption behavior toward H2 at low temperature.
Teaching the structure of immunoglobulins by molecular visualization and SDS‐PAGE analysis
Authors: Rižner Tea Lanišnik 
Published: January 2014

AbstractThis laboratory class combines molecular visualization and laboratory experimentation to teach the structure of the immunoglobulins (Ig). In the first part of the class, the three‐dimensional structures of the human IgG and IgM molecules available through the RCSB PDB database are visualized using freely available software. In the second part, IgG and IgM are studied using electrophoretic methods. Through SDS‐PAGE analysis under reducing conditions, the students determine the number and molecular masses of the polypeptide chains, while through SDS‐PAGE under nonreducing conditions, the students assess the oligomerization of these Ig molecules. The aims of this class are to expand upon the knowledge and understanding of the Ig structure that the students have gained from classroom lectures. The combination of this molecular visualization of the Ig molecules and the SDS‐PAGE experimentation ensures variety in the teaching techniques, while the implication of the Ig molecules in human disease promotes interest for biomedical students. © 2014 by The International Union of Biochemistry and Molecular Biology, 42(2):152–159, 2014.
An educational software tool to teach hyper‐heuristics to engineering students based on the bubble breaker puzzle
Authors: Salcedo‐Sanz S. , Jiménez‐Fernández S. , Matías‐Román J. M. , Portilla‐Figueras J. A. 
Published: January 2014

ABSTRACTThis paper presents an educational software tool to teach Artificial Intelligence (AI) techniques, specifically Hyper‐heuristics, to Engineering students. This tool is based on the “Bubble Breaker” puzzle, an addictive game consisting in an M × M matrix of colored bubbles. These balls, when forming sets of two or more same colored balls, can be popped and cleared out. Thus, this puzzle can be solved by setting many different low‐level heuristics and applying a global search procedure (i.e., evolutionary algorithm) that conforms a robust hyper‐heuristic technique. The hyper‐heuristic decides what low‐level heuristics are the best, and the sequential way in which they have to be applied to gain the highest score. This approach has proven an interesting method to teach AI techniques, since simple heuristics, evolutionary algorithms, and its combination are studied in an increasing manner. © 2014 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:277–285, 2015; View this article online at wileyonlinelibrary.com/journal/cae; DOI 10.1002/cae.21597
Control of Plant Defense Mechanisms and Fire Blight Pathogenesis through the Regulation of 6‐Thioguanine Biosynthesis in Erwinia amylovora
Authors: Coyne Sébastien , Litomska Agnieszka , Chizzali Cornelia , Khalil Mohammed N. A. , Richter Klaus , Beerhues Ludger , Hertweck Christian 
Published: January 2014

AbstractFire blight is a devastating disease of Rosaceae plants, such as apple and pear trees. It is characterized by necrosis of plant tissue, caused by the phytopathogenic bacterium Erwinia amylovora. The plant pathogen produces the well‐known antimetabolite 6‐thioguanine (6TG), which plays a key role in fire blight pathogenesis. Here we report that YcfR, a member of the LTTR family, is a major regulator of 6TG biosynthesis in E. amylovora. Inactivation of the regulator gene (ycfR) led to dramatically decreased 6TG production. Infection assays with apple plants (Malus domestica cultivar Holsteiner Cox) and cell cultures of Sorbus aucuparia (mountain ash, rowan) revealed abortive fire blight pathogenesis and reduced plant response (biphenyl and dibenzofuran phytoalexin production). In the presence of the ΔycfR mutant, apple trees were capable of activating the abscission machinery to remove infected tissue. In addition to unveiling the regulation of 6TG biosynthesis in a major plant pathogen, we demonstrate for the first time that this antimetabolite plays a pivotal role in dysregulating the plant response to infection.
Nickel Boosts Ring‐Opening Activity of Iridium
Authors: Ziaei‐Azad Hessam , Semagina Natalia 
Published: January 2014

AbstractA variety of bimetallic Ni–Ir catalysts were synthesised by preforming nanoparticles in the presence of polyvinylpyrrolidone, followed by deposition on γ‐alumina and high‐temperature polymer removal. The Ni–Ir (1:1 molar ratio) nanoparticles prepared by the hydrogen‐sacrificial technique (Ir reduction on the preformed Ni nanoparticles with surface Ni hydride) allowed increasing indane ring opening activity per total amount of Ir as compared to monometallic Ir. The simultaneous reduction of Ni and Ir precursors was not as efficient. The catalysts were characterised with UV/Vis spectroscopy, TEM, temperature‐programmed reduction, CO2 temperature‐programmed desorption, CO diffuse reflectance Fourier transform spectroscopy, X‐ray photoelectron spectroscopy and CHN analysis. The study only explored the catalyst’s metal function and allows saving rare and expensive iridium without loss of its outstanding performance as a ring‐opening catalyst.
Cereus‐Shaped Mesoporous Rutile TiO2 Formed in Ionic Liquid: Synthesis and Li‐Storage Properties
Authors: Suo Liumin , Sallard Sébastien , Hu Yong‐Sheng , Smarsly Bernd M. , Chen Liquan 
Published: January 2014

AbstractMesoporous rutile TiO2 with a cereus‐shaped structure was synthesized through a low‐temperature sol‐gel synthesis approach in a bromide ionic liquid/water mixture. The electrochemical Li‐storage performance of the annealed material exhibits a high reversible capacity, long cycling stability, and excellent rate capability.
Copper‐Catalyzed Cascade Cyclization Reaction of 2‐Haloaryltriazenes and Sodium Azide: Selective Synthesis of 2 H‐Benzotriazoles in Water
Authors: Shang Xiaobo , Zhao Shixian , Chen Wanzhi , Chen Chao , Qiu Huayu 
Published: January 2014

AbstractA new approach to the synthesis of 2 H‐benzotriazoles is described. This strategy is based on the copper‐catalyzed CN coupling of 2‐haloaryltriazenes or 2‐haloazo compounds with sodium azide and the intramolecular addition of nitrene to NN bonds. This approach allows the synthesis of various N‐amino‐ and N‐aryl‐2 H‐benzotriazoles in water, in good to excellent yields. The procedure is simple and the starting materials and catalyst are easily available, offering a practical and convenient synthetic route to 2‐substituted benzotriazoles.
Insertion of a Single‐Molecule Magnet inside a Ferromagnetic Lattice Based on a 3D Bimetallic Oxalate Network: Towards Molecular Analogues of Permanent Magnets
Authors: Clemente‐León Miguel , Coronado Eugenio , Gómez‐García Carlos J. , López‐Jordà Maurici , Camón Agustín , Repollés Ana , Luis Fernando 
Published: January 2014

AbstractInvited for the cover of this issue are the groups of Eugenio Coronado at the Universidad de Valencia and Fernando Luis at the CSIC‐Universidad de Zaragoza. The image depicts a hybrid crystalline lattice formed by an anisotropic single‐molecule magnet. Read the full text of the article at 10.1002/chem.201303044.
Mind the Methyl: Methyllysine Binding Proteins in Epigenetic Regulation
Authors: Wagner Tobias , Robaa Dina , Sippl Wolfgang , Jung Manfred 
Published: January 2014

AbstractEpigenetics is defined as the phenomenon of heritable phenotypic traits that are not governed by alteration of the genetic code. Major epigenetic control mechanisms include DNA methylation and post‐translational modifications of histones, such as reversible histone acetylation and methylation of lysine residues. Methyllysine binding proteins recognize various levels of lysine methylation and mediate the signaling events that are induced by histone methylation. Therefore, they are also referred to as readers of the epigenetic code. In this article we review the current literature on the structure and biology of methyllysine binding proteins, especially with regard to their potential as drug targets. We also present the available inhibitors that block the interaction of methylated histones with their binding proteins.
Anomalously Enhanced Hydration of Aqueous Electrolyte Solution in Hydrophobic Carbon Nanotubes to Maintain Stability
Authors: Ohba Tomonori 
Published: January 2014

AbstractAn understanding of the structure and behavior of electrolyte solutions in nanoenvironements is crucial not only for a wide variety of applications, but also for the development of physical, chemical, and biological processes. We demonstrate the structure and stability of electrolyte in carbon nanotubes using hybrid reverse Monte Carlo simulations of X‐ray diffraction patterns. Hydrogen bonds between water are adequately formed in carbon nanotubes, although some hydrogen bonds are restricted by the interfaces of carbon nanotubes. The hydrogen bonding network of water in electrolyte in the carbon nanotubes is further weakened. On the other hand, formation of the ion hydration shell is significantly enhanced in the electrolyte in the carbon nanotubes in comparison to ion hydration in bulk electrolyte. The significant hydrogen bond and hydration shell formation are a result of gaining stability in the hydrophobic nanoenvironment.
Synthesis of Carbon Materials–TiO2 Hybrid Nanostructures and Their Visible‐Light Photo‐catalytic Activity
Authors: Li Qian , Bian Juncao , Zhang Li , Zhang Ruiqin , Wang Guozhong , Ng Dickon H. L. 
Published: January 2014

AbstractActivated carbon, graphene, carbon nanotubes and fullerene were incorporated into TiO2 by a solvothermal approach and thermal annealing to produce carbon materials–TiO2 hybrid nanostructures. The carbon materials–TiO2 products were characterised by using SEM, TEM, XRD, Raman spectroscopy, X‐ray photo‐electron spectroscopy, UV‐visible spectroscopy and photo‐luminescence. The aim was to study the interactions between the main TiO2 phase and the carbon components, and the relationships between morphology, structure and photo‐degradation of the rhodamine B (RhB) dye. An enhanced photo‐catalytic degradation of RhB was achieved when using these nanocomposites over that for only using pure TiO2. The superiority in photo‐catalytic activities on the RhB molecules resulted from contributions from the excellent adsorption property, favourable chemical bond formation (TiOC), narrower band gap, smaller particle size and effective charge‐carrier separation of the nanocomposites. Compared with the graphene–, carbon nanotube– and fullerene–TiO2 products, activated carbon–TiO2 exhibited weaker interactions between carbon and titania, lower adsorption for RhB and a larger band gap, which led to lower photo‐catalytic activity of RhB.
Mechanisms for Enhanced Performance of Platinum‐Based Electrocatalysts in Proton Exchange Membrane Fuel Cells
Authors: Su Liang , Jia Wenzhao , Li Chang‐Ming , Lei Yu 
Published: January 2014

AbstractAs a new generation of power sources, fuel cells have shown great promise for application in transportation. However, the expensive catalyst materials, especially the cathode catalysts for oxygen reduction reaction (ORR), severely limit the widespread commercialization of fuel cells. Therefore, this review article focuses on platinum (Pt)‐based electrocatalysts for ORR with better catalytic performance and lower cost. Major breakthroughs in the improvement of activity and durability of electrocatalysts are discussed. Specifically, on one hand, the enhanced activity of Pt has been achieved through crystallographic control, ligand effect, or geometric effect; on the other hand, improved durability of Pt‐based cathode catalysts has been realized by means of the incorporation of another noble metal or the morphological control of nanostructures. Furthermore, based on these improvement mechanisms, rationally designed Pt‐based nanoparticles are summarized in terms of different synthetic strategies such as wet‐chemical synthesis, Pt‐skin catalysts, electrochemically dealloyed nanomaterials, and Pt‐monolayer deposition. These nanoparticulate electrocatalysts show greatly enhanced catalytic performance towards ORR, aiming not only to outperform the commercial Pt/C, but also to exceed the US Department of Energy 2015 technical target ($30/kW and 5000 h).
Rhenium Complexes with Red‐Light‐Induced Anticancer Activity
Authors: Wähler Kathrin , Ludewig Anja , Szabo Patrick , Harms Klaus , Meggers Eric 
Published: January 2014

AbstractRhenium(I) pyridocarbazole complexes with photoinduced antiproliferative activity are reported. The substitutionally inert complexes induce cell death by singlet oxygen generation upon irradiation with red light (λ ≥ 620 nm), whereas only weak background cytotoxicity is observed in the dark. Owing to their ability to inhibit protein kinases (nanomolar IC50 values against Pim1 at 10 μM ATP), this class of rhenium complexes point in the direction of dual function antiproliferative therapy with a single drug in which photodynamic therapy is combined with the inhibition of cancer‐related protein kinases.
Use of protein profiles established by CZE to predict the cultivar of olive leaves and pulps
Authors: Vergara‐Barberán María , Lerma‐García María Jesús , Herrero‐Martínez José Manuel , Simó‐Alfonso Ernesto Francisco 
Published: January 2014

Intact protein profiles established by CZE have been used to predict the cultivar of olive leaves and pulps. For this purpose, proteins were extracted using a mild enzyme‐assisted extraction method, which provided higher protein recoveries and a lower environmental impact than other previously described methods. These extracts were subjected to CZE determination under basic conditions using a BGE composed of 50 mM phosphate, 50 mM tetraborate and 0.1% PVA at pH 9. Nine and 14 common peaks, for leaf and pulp samples, respectively, were identified in the nine cultivars studied in this work. In addition, and using linear discriminant analysis of the CZE data, olive leaf and pulp samples belonging to nine cultivars from different Spanish regions were correctly classified with an excellent resolution among all categories, which demonstrated that intact protein profiles are characteristic of each cultivar.
Assessment of adulteration of soybean proteins in dairy products by 2D microchip‐CE device
Authors: Wu Ruige , Wang Zhiping , Fung Ying Sing , Peng Seah Daphne Yen , Yeung William Shu‐Biu 
Published: January 2014

To determine the adulteration of soybean proteins in dairy product, a microchip‐CE device was developed to isolate selected fraction of soybean and milk proteins in pI range from 5.5∼7.0 by 1D IEF, followed by ITP/CZE in the embedded capillary for preconcentration, separation and UV detection at 280 nm. Compared to IEF‐CZE without ITP preconcentration, the enhancement factor (EF) in detection of soybean proteins was 20 times. Adulteration of 0.1% soybean protein in total dairy proteins can be detected in less than 10 min.