bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linguistic evidence supports date for Homeric epics
Authors: Altschuler Eric Lewin , Calude Andreea S. , Meade Andrew , Pagel Mark 
Published: February 2013

AbstractThe Homeric epics are among the greatest masterpieces of literature, but when they were produced is not known with certainty. Here we apply evolutionary‐linguistic phylogenetic statistical methods to differences in Homeric, Modern Greek and ancient Hittite vocabulary items to estimate a date of approximately 710–760 BCE for these great works. Our analysis compared a common set of vocabulary items among the three pairs of languages, recording for each item whether the words in the two languages were cognate – derived from a shared ancestral word – or not. We then used a likelihood‐based Markov chain Monte Carlo procedure to estimate the most probable times in years separating these languages given the percentage of words they shared, combined with knowledge of the rates at which different words change. Our date for the epics is in close agreement with historians' and classicists' beliefs derived from historical and archaeological sources.
New Pyran‐2‐ones from Alkalophilic Actinomycete, Nocardiopsis alkaliphila sp. Nov. YIM‐80379
Authors: Wang Zhiying , Fu Peng , Liu Peipei , Wang Pei , Hou Jiabo , Li Wenjun , Zhu Weiming 
Published: February 2013

AbstractTwo new pyran‐2‐ones, nocardiopyrones A and B (1 and 2, resp.), along with four known compounds, pyridinols 3–5, and 1‐acetyl‐β‐carboline (6) were isolated from the alkalophilic actinomycete Nocardiopsis alkaliphila sp. nov. YIM‐80379. Their structures were established on the basis of spectroscopic analysis, CD spectra, and the quantum‐chemical ECD calculation. Pyridinols 3–5 were isolated from a natural source for the first time. Compounds 1 and 2 showed weak antibacterial activities against Pseudomonas aeruginosa, Enterobacter aerogenes, and Escherichia coli with MIC values of 20–48 μM. Compound 2 showed weak antimicrobial activities against Candida albicans and Staphylococcus aureus with MIC values of 24 and 48 μM, respectively.
On‐Line Activity Screening for Radical Scavengers from Baccharis chilco
Authors: Argoti Juan C. , Linares‐Palomino Pablo J. , Salido Sofía , Ramírez Bernardo , Insuasty Braulio , Altarejos Joaquín 
Published: February 2013

AbstractBaccharis plants have been used since ancient times in American traditional medicine. Baccharis chilco is a perennial shrub of temperate regions of South America that grows well in rainfall forests of Colombia. Neither chemical composition nor biological studies of this plant have ever been reported. Two caffeoylquinic acid (CQA) derivatives, 5‐O‐[(E)‐caffeoyl]quinic acid (1) and 3,5‐di‐O‐[(E)‐caffeoyl]quinic acid (3), and rosmarinic acid (2) have been isolated from B. chilco growing wild in Colombia, using the on‐line HPLC‐DAD‐DPPH radical‐scavenging detection technique as guidance. In the course of the purification work, L‐chiro‐inositol (4) was also isolated. Structures of the four isolated compounds were determined by spectroscopic methods. Antioxidants 2 and 3 exhibited high antiradical activities evaluated by the 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH.) assay, although somewhat lower than that of the reference compound ascorbic acid. The on‐line HPLC‐DAD‐DPPH technique allowed a rapid pinpointing of antioxidants in the studied EtOH extract, and the facile guided isolation of the target molecules.
Reactive Distillation for Multiple Reaction Systems
Authors: Keller Tobias , Holtbrügge Johannes , Niesbach Alexander , Górak Andrzej 
Published: February 2013

AbstractDie Reaktivdestillation (RD) wird gegenwärtig vor allem zur Umsatzsteigerung in gleichgewichtslimitierten Reaktionssystemen verwendet, die häufig nur eine Hauptreaktion aufweisen. Diese Arbeit hingegen beschäftigt sich mit dem Einsatz der RD in chemischen Systemen mit mehr als einer Hauptreaktion. In solchen Multi‐Reaktionssystemen ist nicht nur der Umsatz der Edukte, sondern auch die Selektivität des Zielprodukts durch das chemische Gleichgewicht begrenzt. Ungeachtet, ob das Zielprodukt als Zwischenprodukt oder nach mehreren aufeinanderfolgenden Reaktionen gebildet wird, kann die RD zur Überwindung solcher Selektivitätslimitierungen beitragen. Dieses Potenzial wird am Beispiel der konsekutiven Umesterung von Dimethylcarbonat mit Ethanol untersucht. Die Ergebnisse umfassender experimenteller Studien in einer Technikumskolonne werden präsentiert, um den Einfluss entscheidender Betriebsparameter auf das Prozessverhalten zu untersuchen.
Visible‐Light‐Active Elemental Photocatalysts
Authors: Liu Gang , Niu Ping , Cheng Hui‐Ming 
Published: February 2013

AbstractSeeking visible‐light‐active photocatalysts for efficient solar‐energy conversion has become an intensifying endeavor worldwide. In this concept paper, general requirements for finding new visible‐light‐active photocatalysts are briefly introduced, and recent progress in exploring elemental photocatalysts for clean‐energy generation and environmental remediation are reviewed. Finally, opportunities and challenges facing elemental photocatalysts are discussed.
Graphene Oxide‐Dispersed Pristine CNTs Support for MnO2 Nanorods as High Performance Supercapacitor Electrodes
Authors: You Bo , Li Na , Zhu Hongying , Zhu Xiaolan , Yang Jun 
Published: February 2013

AbstractA MnO2–CNT–graphene oxide (MCGO) nanocomposite is fabricated using graphene oxide (GO) as a surfactant to directly disperse pristine carbon nanotubes (CNTs) for the subsequent deposition of MnO2 nanorods. The resulting MCGO nanocomposite is used as a supercapacitor electrode that shows ideal capacitive behavior (i.e., rectangular‐shaped cyclic voltammograms), large specific capacitance (4.7 times higher than that of free MnO2) even at high mass loading (3.0 mg cm−2), high energy density (30.4–14.2 Wh kg−1), large power density (2.6–50.5 kW kg−1), and still retains approximately 94 % of the initial specific capacitance after 1000 cycles. The advanced capacity, rate capability, and cycling stability may be attributed to the unique architecture, excellent ion wettability of GO with enriched oxygen‐containing functional groups, high conductivity of CNTs, and their synergistic effects when combined with the other components. The results suggest that the MnO2–CNT–GO hybrid nanocomposite architecture is very promising for next generation high‐performance energy storage devices.
N‐Heterocyclic Carbene Dirhodium(II) Complexes as Catalysts for Allylic and Benzylic Oxidations
Authors: Coelho Jaime A. S. , Trindade Alexandre F. , Wanke Riccardo , Rocha Bruno G. M. , Veiros Luis F. , Gois Pedro M. P. , Pombeiro Armando J. L. , Afonso Carlos A. M. 
Published: February 2013

AbstractThe experimental conditions (solvent, base, temperature and oxidant) for allylic and benzylic oxidation reactions catalyzed by dirhodium(II)/N‐heterocyclic carbene (NHC) complexes were optimized for the first time in this work. The oxidations of cyclohexene and fluorene were used as model reactions. Two optimized experimental conditions for both types of oxidations were found, which resulted in their ketone [aerobic conditions, 40 °C, 1 equiv. tBuOOH (TBHP)] or tert‐butyl peroxide derivatives (anaerobic conditions, 25 °C, 2 equiv. TBHP). The dirhodium(II) complexes undergo a single‐electron reversible oxidation by cyclic voltammetry in CH2Cl2, which is assigned to the Rh24+/Rh25+ redox couple at an oxidation potential that is lowered upon sequential axial coordination of further ligands to the Rh–Rh centre. The oxidation potential is discussed in terms of the electron‐donor character of the NHC ligand, which was shown to act as an effective electron‐releaser to the Rh24+ centre, and the electrochemical behaviour is compared to the observed catalytic activity.
NavMol 2.0 – A Molecular Structure Navigator/Editor for Blind and Visually Impaired Users
Authors: Fartaria Rui P. S. , Pereira Florbela , Bonifácio Vasco D. B. , Mata Paulina , Aires‐de‐Sousa João , Lobo Ana M. 
Published: February 2013

AbstractThe NavMol 2.0 program, a software that enables the navigation of molecular structures and chemical reactions by blind and visually impaired (BVI) users, is presented. The software enables BVI users to interpret and edit molecular structures by making use of common accessibility tools. NavMol 2.0 uses voice synthesizers and time clock polar type coordinates to communicate with the blind user and, at the same time, displays a conventional chemical sketch on the screen for sighted users. The new version of the program is based on the Chemistry Development Kit (CDK) that provides a chemoinformatics infrastructure. In order to help the navigation, automatic perception of structural features and their location were implemented, including functional groups, rings, and reaction centers. The editing features enable the building of chemical structures that can be exported and subsequently utilized in other software packages. This software is especially suited to be used by BVI researchers or in “inclusive classrooms”, providing BVI students equal opportunities, greatly enhancing the communication between BVI and fellow sighted students, as well as teachers.
New Potentiometric Sensors for Picrate Determination Using Flow‐Through System: Application to Kinetic Assessment of Se(IV)
Authors: Hassan Saad S. M. , Badr Ibrahim H. A. , Kamel Ayman H. , Mohamed Mona S. 
Published: February 2013

AbstractTwo new selective and sensitive poly(vinyl chloride) membrane sensors are developed for measuring picrate ions based on the use of nitron picrate [(Nit)(Pic)] and iron(II)‐bathophenanthroline picrate [Fe(bphen)3)(Pic)2] ion pairs in plasticized poly(vinyl chloride) membrane. The sensors display Nernstian response with slopes of −57.2±0.8 and −58.8±0.5 mV decade−1 over the range of 3.0×10−5 to −1.0×10−2 and 4.6×10−6–1.0×10−2 mol L−1 and detection limits of 7.4×10−6 and 3.07×10−6 mol L−1 for [(Nit)(Pic)] and [Fe(bphen)3)(Pic)2] membrane‐based sensors, respectively. The sensors exhibit long life‐span, long term potential stability, high reproducibility, fast response and good discrimination ability towards picrate ions in comparison with many other anions. A tubular detector based on [Fe(bphen)3][Pic]2 was further developed and coupled to a flow‐injection system for picrate (Pic) determination. Under optimized conditions, the linearity range is 1.0×10−5–1.0×10−1 mol L−1, with a slope of −47.9±0.1 mV decade−1 and a reproducibility of ±0.3 mV (n=5). The sensor is utilized for a kinetic quantification of selenium in pharmaceutical preparations. The alkaline solution of picrate is allowed to react in a batch system with Na2S, in the presence of selenium(IV) as a catalyst. The changes in potential, resulting from the decrease of the picrate anions are monitored with the picrate sensor. The calibration curve of Se is linear in the concentration range 0.14–0.7 µg mL−1, with a lower limit of detection of 1.0 ng mL−1.
Natural gas matters: Gas to liquids coming on strong in United States
Authors: Smead Richard G. 
Published: February 2013

AbstractThere has been a robust debate over the use of the nation's natural gas abundance to support liquefied natural gas (LNG) exports. As has been explained here before, and as the Department of Energy appears to recognize, the value of stable, growing demand such as LNG destined for international markets is essential to stabilizing the course of development of the major shale gas plays.
Dynamic Combinatorial Libraries of Macrocyclic Imines and Their Applications
Authors: Fischmann Svenja , Lüning Ulrich 
Published: February 2013

AbstractThe reversibility of imine formation from amines and carbonyl compounds, such as aldehydes and ketones, allows the generation of dynamic combinatorial libraries (DCLs). By applying templates to these DCLs, members matching these templates can be amplified. Starting from the very same DCLs, the addition of different templates allows the synthesis of different products. The nature of the template alone determines which product is amplified. The template can also protect the imine bond from hydrolysis. Thus, imines can be generated in the presence of water. In mixtures of water and hydrophobic layers, transport has been observed. In contrast to most transport experiments, in which suitable ion carriers have to be added, in the systems described here, the ions act as templates for the formation of their own carriers.
STRATEGY THEME ‘SYSTEMS’: A DISCUSSION PAPER
Authors: Backeberg Gerhard R. 
Published: February 2013

ABSTRACTTechnical activities of the International Commission on Irrigation and Drainage (ICID) are organised under four Strategy Themes of ‘Basin’, ‘Systems’, ‘On‐farm’ and ‘Knowledge’. On request of ICID, an appraisal of gaps, vision and future direction of the Strategy Theme ‘Systems’ was undertaken as a basis for discussion. For this purpose, definitions of key terms are provided to correctly place Strategy Themes within the Water System, which enables an outward focus on farmers and consumers that should be served by experts. Assessment of Work Bodies allocated under this specific Strategy Theme shows that overall, the performance does not fully support in achieving the mission of ICID. It is advisable that the allocation must be reconsidered within the conceptual framework of Complex Adaptive Systems. Effective operations must ensure adherence to the mandate, work plan, activities and reporting by participating members representing various National Committees. Proposals are made for the conclusion of activities of existing Work Bodies and for the establishment of new Work Bodies, with priority attention to irrigation and drainage water management within a renamed Strategy Theme ‘Schemes’. The incentives for participation in Work Bodies by ICID member countries are emphasized and the future strategic direction with action plans for the next three years is recommended. Copyright © 2013 John Wiley & Sons, Ltd.
ECONOMIC ANALYSIS OF DRIP‐IRRIGATED KINNOW MANDARIN ORCHARD UNDER DEFICIT IRRIGATION AND PARTIAL ROOT ZONE DRYING
Authors: Panigrahi P. , Sharma R. K. , Parihar S. S. , Hasan M. , Rana D. S. 
Published: February 2013

ABSTRACTThe profitability of regulated deficit irrigation (RDI), sustained deficit irrigation (SDI), and SDI with partial root zone drying (PRD) strategies was compared to that with full irrigation (FI: 100% crop evapotranspiration) in drip‐irrigated Kinnow mandarin in northern India. RDI was scheduled with two irrigation levels: no irrigation and 50% crop evapotranspiration (ETc.) imposed in the early fruit growth period (EFGP) and final fruit growth period (FFGP) singly and in combination, whereas SDI was scheduled at 50% ETc and 75% ETc with and without the PRD technique. The highest fruit yield was recorded with FI, which was statistically on a par (p > 0.05) with that with SDI at 50% ETc with PRD (PRD50). Economic‐based comparison shows that all the treatments were economically viable since their profitability (net return, INR 137 000–1 300 000 ha‐1 and benefit–cost ratio, 2.1–14.3) were viable. The net return generated with PRD50 was statistically (p > 0.05) at par with that generated with FI. However, the benefit–cost ratio and economic water productivity calculated with PRD50 were found to be significantly (p < 0.05) higher (36 and 87%, respectively) than that with FI. These results lead us to conclude that the PRD50 strategy could be used to improve irrigation water productivity substantially in commercial Kinnow mandarin orchards in sandy loam soil. Copyright © 2013 John Wiley & Sons, Ltd.
Diatom assemblages and limnological variables from 40 lakes and ponds on Bathurst Island and neighboring high Arctic islands
Authors: Hadley Kristopher R. , Douglas Marianne S. V. , Lim Darlene , Smol John P. 
Published: February 2013

AbstractWe examined the influence of catchment geology, specifically differences in buffering capacity, on the limnological characteristics and surface sediment diatom assemblages from lakes and ponds from Bathurst Island, High Arctic Canada. Differences in buffering capacity exist on Bathurst Island due to a geological gradient that spans from carbonate‐bearing limestone in the east, to more stable quartz sandstone, siltstone, and shale in the west. We collected physical and chemical limnological data, as well as surface sediment diatom assemblages from nine ponds on the poorly buffered western portion of the island and combined these observations with a previously published dataset of 31 lakes and ponds, from the well‐buffered eastern region. The addition of these nine ponds expanded the pH gradient of the existing Bathurst Island dataset (pH 8.0–8.6) to pH 6.8–8.6. A regional, weighted average diatom‐inferred pH model was developed and showed strength similar to other Arctic calibration sets (, root‐mean‐squared‐error of prediction (RMSEP) = 0.298). Given the links between climate and pH shifts in the High Arctic, the ability to reconstruct pH should be a valuable tool for future paleolimnological studies.
Key Trends and Challenges in Corporate Governance
Authors: Sherman Andrew J. 
Published: February 2013

AbstractThe events of the past 10 years have placed corporate governance under a microscope. Both share‐holders and the markets are challenging corporate boards to be accountable‐and to carefully follow best practices. The author takes a look at the key trends and challenges facing governance as we move forward. What vital questions must corporate leaders answer? © 2013 Andrew J. Sherman
Immunolocalization of Keratin‐Associated Beta‐Proteins (Beta‐Keratins) in Pad Lamellae of Geckos Suggest that Glycine–Cysteine‐Rich Proteins Contribute to Their Flexibility and Adhesiveness
Authors: ALIBARDI LORENZO 
Published: February 2013

AbstractThe epidermis of digital pads in geckos comprises superficial microornamentation from the oberhautchen layer that form long setae allowing these lizards to climb vertical surfaces. The beta‐layer is reduced in pad lamellae but persists up to the apical free margin. Setae are made of different proteins including keratin‐associated beta‐proteins, formerly indicated as beta‐keratins. In order to identify specific setal proteins the present ultrastructural study on geckos pad lamellae analyzes the immunolocalization of three beta‐proteins previously found in the epidermis and adhesive setae of the green anolis. A protein rich in glycine but poor in cysteine (HgG5‐like) is absent or masked in gecko pad lamellae. Another protein rich in glycine and cysteine (HgGC3‐like) is weakly present in setae, oberhautchen and beta‐layer. A glycine and cysteine medium rich beta‐protein (HgGC10‐like) is present in the lower part of the beta‐layer but is absent in the oberhautchen, setae, and mesos layer. The latter two proteins may form intermolecular bonds that contribute to the flexibility of the corneous material sustaining the setae. The pliable alpha‐layer present beneath the thin beta‐layer and in the hinge region of the pad lamellae also contains HgGC10‐like proteins. Based on the possibility that some HgGC3‐like or other cys‐rich beta‐proteins are charged in the setae it is suggested that their charges influence the mechanism of adhesion increasing the induction of dipoles on the substrate and enhancing attractive van der Waals forces. J. Exp. Zool. 319A:166–178, 2013. © 2013 Wiley Periodicals, Inc.
Becoming a Tourist
Authors: McKercher Bob , Lui Sau‐Lai 
Published: February 2013

ABSTRACTThis paper explores the processes of entry into and disentanglement from touristhood by a group of inexperienced long haul tourists making their first pleasure trip to Asia. Tourism is seen as an activity that occurs in liminal time and space, enabling the participant to adopt a new role with a different set of social structures and expected behaviors, to a greater or lesser extent, when he or she travels. While the original paper investigating this topic written by Jafai (1987) infers that the process of engagement and disentanglement is relatively quick and seamless, this study found both processes were much more complex, prolonged and subtle than previously envisioned. Copyright © 2013 John Wiley & Sons, Ltd.
Gelatin‐Methacrylamide Hydrogels as Potential Biomaterials for Fabrication of Tissue‐Engineered Cartilage Constructs
Authors: Schuurman Wouter , Levett Peter A. , Pot Michiel W. , van Weeren Paul René , Dhert Wouter J. A. , Hutmacher Dietmar W. , Melchels Ferry P. W. , Klein Travis J. , Malda Jos 
Published: February 2013

AbstractGelatin‐methacrylamide (gelMA) hydrogels are shown to support chondrocyte viability and differentiation and give wide ranging mechanical properties depending on several cross‐linking parameters. Polymer concentration, UV exposure time, and thermal gelation prior to UV exposure allow for control over hydrogel stiffness and swelling properties. GelMA solutions have a low viscosity at 37 °C, which is incompatible with most biofabrication approaches. However, incorporation of hyaluronic acid (HA) and/or co‐deposition with thermoplastics allows gelMA to be used in biofabrication processes. These attributes may allow engineered constructs to match the natural functional variations in cartilage mechanical and geometrical properties.magnified image
Exzitonen — Resonanzen des Festkörpers
Authors: Treusch Joachim 
Published: February 2013

AbstractDie erste über die Einteilchennäherung hinausgehende Beschreibung der möglichen Anregungszustände eines Halbleiters ist das „Exzitonenbild”︁: In ihm wird berücksichtigt, daß das ins Leitungsband angehobene Elektron mit dem im Valenzband hinterlassenen Loch wechselwirkt und auf diese Weise ein Analogon zum Wasserstoffatom bildet, das „Exziton ”︁. Die Wechselwirkungen dieses polarisierbaren Zweiteilchengebildes mit dern Rest des Festkörpers und äußeren Feldern werden in ihrer theoretischen Konzeption und ihrer experimentellen Realisierung beschrieben.
Wasserstoff in Metallen
Authors: Peisl Hans 
Published: February 2013

AbstractWasserstoff ist in vielen Metallen in hoher Konzentration löslich. Dabei ergeben sich interessante physikalische Fragestellungen, die von Grundlagenproblemen bis hin zu technologischen Anwendungen reichen. Anhand des Systems Niob/Wasserstoff wird gezeigt, wie neue physikalische Konzepte zum Verständnis von Phasenübergängen in diesem System beitragen.
Proteomic analysis of the aqueous humor in patients with wet age‐related macular degeneration
Authors: Yao Jiaqi , Liu Xiaoyi , Yang Qin , Zhuang Min , Wang Feng , Chen Xi , Hang Hui , Zhang Weiwei , Liu Qinghuai 
Published: February 2013

PurposeA number of studies have shown that the levels of some proteins in the aqueous humor (AH) are altered and correlate with the mechanisms or prognosis of many eye diseases. To identify the possible mechanisms that lead to the development of wet age‐related macular degeneration (AMD), a proteomic analysis of the AH composition from wet AMD patients was performed and compared with that from non‐AMD cataract patients.Experimental designSix wet AMD and six non‐AMD cataract patients were enrolled. A proteomic approach which included two‐dimensional electrophoresis coupled with MS and bioinformatics methods were used to identify AH proteins with altered expression in wet AMD compared with non‐AMD patients. An ELISA was used to validate the proteomic results.ResultsWe separated 78 protein spots and identified 68 that were differently expressed in the wet AMD group and controls. Numerous proteins identified in this study are implicated in inflammation, apoptosis, angiogenesis, and oxidative stress.Conclusions and clinical relevanceThe AH protein composition was significantly different between wet AMD and non‐AMD patients. The proteins identified in this study may be potential biomarkers of wet AMD development and might play a role in the mechanisms of wet AMD.