bluuebunny/crossref_metadata_2025_split huggingface dataset:
2‐Phenylquinoline‐Based Cyclometalated Platinum(II) Complexes: Synthesis and Structure–Photoelectric Properties Relationship in Oxygen Sensing
Authors: Liu Chun , Song Xinlong , Wang Zhonggang , Qiu Jieshan 
Published: July 2014

AbstractNovel 2‐phenylquinoline‐based cyclometalated PtII complexes are synthesized and fully characterized. 2‐Phenylquinoline derivatives with a functional group at the 4‐position of the phenyl ring are prepared through an efficient Pd‐catalyzed ligand‐free and aerobic Suzuki reaction of 2‐bromoquinoline with arylboronic acids. The photophysical properties of the complexes demonstrate that the introduction of a diphenylamino group at the 4‐position of the phenyl ring affects the HOMO level of the PtII complex significantly, resulting in a marked decrease in energy gap. The emission or energy gap is not influenced clearly by other substituents (methyl, cyano, fluoro, trifluoromethyl, methoxyl, carbazol‐9‐yl) at the 4‐position of the phenyl ring. All the complexes show redshifted room‐temperature phosphorescence emission (at 578–599 nm) relative to the model complex Pt(ppy)acac (at 486 nm). The oxygen sensitivity of the complexes is evaluated quantitatively in a polymer film. The films containing the PtII complexes are sensitive to O2, and the luminescence changes gradually and reversibly with O2 concentration. The PtII complex with a triphenylamino moiety exhibits the highest sensitivity (${K{{app\hfill \atop SV\hfill}}}$=0.020 Torr−1). The 2‐phenylquinoline‐based PtII complexes are potential candidates for efficient luminescent oxygen sensing. The present results provide a systematic study on the structure–property relationship between the 2‐phenylquinoline‐based PtII complexes and oxygen sensing.
In situ Observation of Radicals and Molecular Products During Lignin Pyrolysis
Authors: Bährle Christian , Custodis Victoria , Jeschke Gunnar , van Bokhoven Jeroen A. , Vogel Frédéric 
Published: July 2014

AbstractLignin pyrolysis is a promising method for the sustainable production of phenolic compounds from biomass. However, detailed knowledge about the radicals involved in this process and their influence on the molecular products is missing. Herein, we report on the pyrolysis of hard‐ and softwood Klason lignins under inert gas conditions in a temperature range between 350–550 °C. During the pyrolysis process, the formed radicals were detected by in situ high‐temperature electron paramagnetic resonance spectroscopy. The overall formation of volatile products during lignin pyrolysis was determined using thermogravimetric analysis. The volatile molecular products were characterized and quantified using GC–MS analysis. Major differences were observed between hardwood and softwood lignins. Hardwood lignins form more radicals and volatile products than softwood lignins at temperatures from 350 to 450 °C. In the late stages of the pyrolysis process at 550 °C radical quenching reactions become dominant in hardwood lignins. We identified the disproportionation of two semiquinone radicals to quinone and hydroquinone species as the most likely quenching reaction. Our results show that both the pyrolysis temperature and the type of lignin source have a major influence on radical formation and the molecular products during the depolymerization of lignin.
Coumarin 6 as a fluorescent model drug: How to identify properties of lipid colloidal drug delivery systems via fluorescence spectroscopy?
Authors: Finke Jan Henrik , Richter Claudia , Gothsch Thomas , Kwade Arno , Büttgenbach Stephanus , Müller‐Goymann Christel C. 
Published: July 2014

In the development of colloidal lipid drug delivery systems (DDS), the localization of the drug within the DDS, the protective potential of the DDS as well as the compatibility of the drug with the excipients are of special interest. In this study, Coumarin 6 (C6), a fluorescent dye frequently used to facilitate the traceability of DDS in vitro, is demonstrated as a tool to gain insight into the aforementioned properties by fluorescence spectroscopy. Both ways of loading C6 to solid colloidal DDS (pre‐loading to the lipid matrix or post‐loading to the ready DDS after its processing) led to a localization of C6 in the interfacial layer between solid lipid nanoparticles (SLN) and aqueous medium. In the case of pre‐loading, C6 is homogenously distributed in emulsion droplets and expelled from the lipid matrix due to crystallization. Nanoemulsions distributed C6 in the liquid lipid matrix itself and cause a hypsochromic shift of fluorescence spectra. Larger surface areas of emulsion droplets due to smaller droplet sizes displayed more interaction of C6 with the aqueous phase as a bathochromic shoulder in fluorescence spectra. Measured fluorescence intensity was linearly dependent on light scattering of colloidal DDS of the same excipients. A simple method to evaluate the protective properties of DDS was presented and displayed that (i) nanoemulsions provide more protection compared with SLN and (ii) higher phospholipid concentration improve the protection within SLN.Practical applications: In the development of colloidal DDS, it is important to identify the localization and distribution of a (model) drug in compartments within the disperse system. The simple approach by fluorescence spectroscopy presented in this study supplies information about the localization of drug substances with properties comparable with the fluorescent probe used. The results assist formulation development as a quick screening tool to elucidate (i) the localization of the probe, (ii) the microenvironment of the probe (e.g., differentiation of the physical state of the disperse phase), and (iii) the protection of the probe against damaging agents from the aqueous phase.The fluorescent dye Coumarin 6 was applied as model drug in colloidal lipid drug delivery systems. Fluorescence spectroscopy proved able to identify the localization of the model compound, the physical state of the dispersed phase, and the protective potential of the DDS, especially dependent on phospholipid concentration.
Influence of Charging Current and Potential Drop on the Propagation of the Change in the Membrane Potential
Authors: Kushida Yuki , Shirai Osamu , Kitazumi Yuki , Kano Kenji 
Published: July 2014

AbstractPropagation of a change in a potential difference between two aqueous phases (W1 and W2) across a membrane was examined by using three membrane cells (A, B and C). At first, the cell A was electrically connected with the cell B by controlling the ionic compositions. By changing the connection with the cell A from the cell B to the cell C indicating the different membrane potential, the change of the membrane potential was propagated. The delay and decrement of the propagation was observed by setting capacitors or resistors in the electric circuit.
Detection and reconstruction of large‐scale coherent flow structures in gravel‐bed rivers
Authors: Franca Mário J. , Lemmin Ulrich 
Published: July 2014

ABSTRACTLarge‐scale flow structures (LSFS) in the streamwise direction are important features of gravel‐bed river flows, because they may contribute to sediment transport and gas exchange. In the present study, these structures are detected using Huang's empirical mode decomposition and reconstructed with phase‐averaging techniques based on a Hilbert transform of the velocity signal. The analysis is based on the fluctuating component of 15 quasi‐instantaneous velocity profiles measured with a three‐dimensional (3D) acoustic Doppler velocity profiler (ADVP) in an armoured gravel‐bed river with a low relative submergence of 2.9 (ratio between flow depth and bed grain diameter). LSFS were identified in most of the measured profiles and consistently showed similar features. We were able to characterize the geometry of these large‐scale coherent structures: the front has a vertical linear shift in the time domain and a vertical profile corresponding to a first quarter moon with the apex situated at z/h ≈ 0.4. In the vertical, the front scales with flow depth h, and in the streamwise direction, LSFS scale with three to seven times the mean flow depth. On the bed, the effect of LSFS is a periodic non‐linear variation of the friction velocity on average between 0.90 and 1.10 times the mean value. A model for the friction velocity cycle resulting from LSFS oscillation is presented. Copyright © 2014 John Wiley & Sons, Ltd.
The effect of El Niño Southern Oscillation cycles on the decadal scale suspended sediment behavior of a coastal dry‐summer subtropical catchment
Authors: Gray Andrew B. , Pasternack Gregory B. , Watson Elizabeth B. , Warrick Jonathan A. , Goñi Miguel A. 
Published: July 2014

AbstractRivers display temporal dependence in suspended sediment–water discharge relationships. Although most work has focused on multi‐decadal trends, river sediment behavior often displays sub‐decadal scale fluctuations that have received little attention. The objectives of this study were to identify inter‐annual to decadal scale fluctuations in the suspended sediment–discharge relationship of a dry‐summer subtropical river, infer the mechanisms behind these fluctuations, and examine the role of El Niño Southern Oscillation climate cycles. The Salinas River (California) is a moderate sized (11 000 km2), coastal dry‐summer subtropical catchment with a mean discharge (Qmean) of 11.6 m3 s−1. This watershed is located at the northern most extent of the Pacific coastal North America region that experiences increased storm frequency during El Niño years. Event to inter‐annual scale suspended sediment behavior in this system was known to be influenced by antecedent hydrologic conditions, whereby previous hydrologic activity regulates the suspended sediment concentration–water discharge relationship. Fine and sand suspended sediment in the lower Salinas River exhibited persistent, decadal scale periods of positive and negative discharge corrected concentrations. The decadal scale variability in suspended sediment behavior was influenced by inter‐annual to decadal scale fluctuations in hydrologic characteristics, including: elapsed time since small (~0.1 × Qmean), and moderate (~10 × Qmean) threshold discharge values, the number of preceding days that low/no flow occurred, and annual water yield. El Niño climatic activity was found to have little effect on decadal‐scale fluctuations in the fine suspended sediment–discharge relationship due to low or no effect on the frequency of moderate to low discharge magnitudes, annual precipitation, and water yield. However, sand concentrations generally increased in El Niño years due to the increased frequency of moderate to high magnitude discharge events, which generally increase sand supply. Copyright © 2014 John Wiley & Sons, Ltd.
Effects of single and multiple applications of glyphosate or aminopyralid on simple constructed plant communities
Authors: Pfleeger Thomas , Blakeley-Smith Matthew , Lee E. Henry , King George , Plocher Milton , Olszyk David 
Published: July 2014

Abstract

To determine effects of multiple applications of herbicides on small constructed plant communities, Prunella vulgaris L.var. lanceolata Fern, Festuca roemeri (Pavlick) Alexeev, Clarkia amoena (Lehm.) Nels., and Cynosurus echinatus L. were grown together in small field plots. Plants were treated with glyphosate at target concentrations of 0 × , 0.01 × , 0.1 × , and 0.2× a field application rate (FAR) of 1122 g ha−1 active ingredient (a.i.) for 3 yr in 1 location, and for 2 yr in a second location. Plants also were treated with aminopyralid at 0 × , 0.037 × , 0.136 × , and 0.5× FAR of 123 g ha−1 a.i. for 2 yr in 2 locations. Plants received 1, 2, or 3 applications of each herbicide each year. Species and community responses depended on herbicide concentration and number of applications. With glyphosate, plant volume (modified formula for a cone) tended to decrease for all species (especially C. echinatus), and the decreases generally became larger with more applications. Plant communities exposed to the 2 greatest concentrations initially differed from controls but then appeared to recover. With aminopyralid, C. amoena was essentially eliminated from the communities, especially at the 2 greatest FARs, whereas the other 3 species tended to have significant increases in volume, especially at the 2 smallest FARs. With aminopyralid, increasing numbers of applications produced variable results, and the plant community volume never tended to recover. Environ Toxicol Chem 2014;33:2368–2378. Published 2014 Wiley Periodicals Inc., on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.
Methylated phenanthrenes are more potent than phenanthrene in a bioassay of human aryl hydrocarbon receptor (AhR) signaling
Authors: Sun Yue , Miller Charles A. , Wiese Thomas E. , Blake Diane A. 
Published: July 2014

Abstract

Alkylated polycyclic aromatic hydrocarbons (APAHs) are abundant in petroleum, but data regarding their toxicological properties are limited. A survey of all monomethylated phenanthrene structures revealed that they were 2 times to 5 times more potent than phenanthrene for activation of human aryl hydrocarbon receptor in a yeast bioassay. Phenanthrenes with equatorial methyl groups had the greatest potency. The greater potency of the methylated phenanthrenes highlights the need for more toxicological data on APAHs. Environ Toxicol Chem 2014;33:2363–2367. © 2014 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.
Lead toxicity to Lemna minor predicted using a metal speciation chemistry approach
Authors: Antunes Paula M.C. , Kreager Nancy J. 
Published: July 2014

Abstract

In the present study, predictive measures for Pb toxicity and Lemna minor were developed from bioassays with 7 surface waters having varied chemistries (0.5–12.5 mg/L dissolved organic carbon, pH of 5.4–8.3, and water hardness of 8–266 mg/L CaCO3). As expected based on water quality, 10%, 20%, and 50% inhibitory concentration (IC10, IC20, and IC50, respectively) values expressed as percent net root elongation (%NRE) varied widely (e.g., IC20s ranging from 306 nM to &gt;6920 nM total dissolved Pb), with unbounded values limited by Pb solubility. In considering chemical speciation, %NRE variability was better explained when both Pb hydroxides and the free lead ion were defined as bioavailable (i.e., f{OH}) and colloidal Fe(III)(OH)3 precipitates were permitted to form and sorb metals (using FeOx as the binding phase). Although cause and effect could not be established because of covariance with alkalinity (p = 0.08), water hardness correlated strongly (r2 = 0.998, p &lt; 0.0001) with the concentration of total Pb in true solution ([Pb]T_True solution). Using these correlations as the basis for predictions (i.e., [Pb]T_True solution vs water hardness and %NRE vs f{OH}), IC20 and IC50 values produced were within a factor of 2.9 times and 2.2 times those measured, respectively. The results provide much needed effect data for L. minor and highlight the importance of chemical speciation in Pb-based risk assessments for aquatic macrophytes. Environ Toxicol Chem 2014;33:2225–2233. © 2014 SETAC
Hydrological footprints of urban developments in the Lake Simcoe watershed, Canada: a combined paired‐catchment and change detection modelling approach
Authors: Oni Stephen K. , Futter Martyn N. , Buttle James , Dillon Peter J. 
Published: July 2014

AbstractUrban sprawl and regional climate variability are major stresses on surface water resources in many places. The Lake Simcoe watershed (LSW) Ontario, Canada, is no exception. The LSW is predominantly agricultural but is experiencing rapid population growth because of its proximity to the Greater Toronto area. This has led to extensive land use changes that have impacted its water resources and altered run‐off patterns in some rivers draining to the lake. Here, we use a paired‐catchment approach, hydrological change detection modelling and remote sensing analysis of satellite images to evaluate the impacts of land use change on the hydrology of the LSW (1994 to 2008). Results show that urbanization increased up to 16% in Lovers Creek, the most urban‐impacted catchment. Annual run‐off from Lovers Creek increased from 239 to 442 mm/year in contrast to the reference catchment (Black River at Washago) where run‐off was relatively stable with an annual mean of 474 mm/year. Increased annual run‐off from Lovers Creek was not accompanied by an increase in annual precipitation. Discriminant function analysis suggests that early (1992–1997; pre‐major development) and late (2004–2009; fully urbanized) periods for Lovers Creek separated mainly based on model parameter sets related to run‐off flashiness and evapotranspiration. As a result, parameterization in either period cannot be used interchangeably to produce credible run‐off simulations in Lovers Creek because of greater scatter between the parameters in canonical space. Separation of early and late‐period parameter sets for the reference catchment was based on climate and snowmelt‐related processes. This suggests that regional climatic variability could be influencing hydrologic change in the reference catchment, whereas urbanization amplified the regional natural hydrologic changes in urbanizing catchments of the LSW. Copyright © 2014 John Wiley & Sons, Ltd.
Osteogenic Cell Cultures Cannot Utilize Exogenous Sources of Synthetic Polyphosphate for Mineralization
Authors: Ariganello Marianne B. , Omelon Sidney , Variola Fabio , Wazen Rima M. , Moffatt Pierre , Nanci Antonio 
Published: July 2014

ABSTRACTPhosphate is critical for mineralization and deficiencies in the regulation of free phosphate lead to disease. Inorganic polyphosphates (polyPs) may represent a physiological source of phosphate because they can be hydrolyzed by biological phosphatases. To investigate whether exogenous polyP could be utilized for mineral formation, mineralization was evaluated in two osteogenic cell lines, Saos‐2 and MC3T3, expressing different levels of tissue non‐specific alkaline phosphatase (tnALP). The role of tnALP was further explored by lentiviral‐mediated overexpression in MC3T3 cells. When cells were cultured in the presence of three different phosphate sources, there was a strong mineralization response with β‐glycerophosphate (βGP) and orthophosphate (Pi) but none of the cultures sustained mineralization in the presence of polyP (neither chain length 17‐Pi nor 42‐Pi). Even in the presence of mineralizing levels of phosphate, low concentrations of polyP (50 μM) were sufficient to inhibit mineral formation. Energy‐dispersive X‐ray spectroscopy confirmed the presence of apatite‐like mineral deposits in MC3T3 cultures supplemented with βGP, but not in those with polyP. While von Kossa staining was consistent with the presence or absence of mineral, an unusual Alizarin staining was obtained in polyP‐treated MC3T3 cultures. This staining pattern combined with low Ca:P ratios suggests the persistence of Ca‐polyP complexes, even with high residual ALP activity. In conclusion, under standard culture conditions, exogenous polyP does not promote mineral deposition. This is not due to a lack of active ALP, and unless conditions that favor significant processing of polyP are achieved, its mineral inhibitory capacity predominates. J. Cell. Biochem. 115: 2089–2102, 2014. © 2014 Wiley Periodicals, Inc.
Contrast‐enhanced endoscopic ultrasonography can predict a higher malignant potential of gastrointestinal stromal tumors by visualizing large newly formed vessels
Authors: Yamashita Yasunobu , Kato Jun , Ueda Kazuki , Nakamura Yasushi , Abe Hiroko , Tamura Takashi , Itonaga Masahiro , Yoshida Takeichi , Maeda Hiroki , Moribata Kosaku , Niwa Toru , Maekita Takao , Iguchi Mikitaka , Tamai Hideyuki , Ichinose Masao 
Published: July 2014

ABSTRACTBackgroundThe aim of this study was to elucidate the histologic and clinical implications of detection of intratumoral vessels on contrast‐enhanced endoscopic ultrasonography (CE‐EUS) in gastrointestinal stromal tumors (GISTs).MethodsThirteen patients with a GIST, all of whom were referred for surgery, underwent presurgical CE‐EUS. The malignant potential, assessed according to the modified Fletcher risk classification system, and the histologic degree of angiogenesis were compared with the presence or absence of intratumoral vessels on CE‐EUS.ResultsOf the six tumors with intratumoral vessels observed on CE‐EUS, five were intermediate‐ or high‐risk GISTs, and the remaining seven negative cases were categorized as very low risk or low risk. The presence of intratumoral vessels on CE‐EUS was significantly correlated with a higher‐risk classification (p = 0.005). On histologic examination, all GISTs having visualized vessels incorporated vessels of more than 500 μm in diameter. The large intratumoral vessels of the five intermediate‐ or high‐risk GISTs lacked elastic fibers, suggesting that they were neovascular in nature. These higher‐risk tumors were also found, by immunohistochemical analysis, to have high expression of vascular endothelial growth factor.ConclusionsIntratumoral vessels observed in GISTs on CE‐EUS are correlated with a higher degree of angiogenesis, resulting in higher malignant potential. © 2014 Wiley Periodicals, Inc. J Clin Ultrasound, 43:89–97, 2015
In vivo monitoring of intracellular chloroplast movements in intact leaves of c4 plants using two‐photon microscopy
Authors: Ryu Jeongeun , Nam Hyoseok , Kim Hae Koo , Joo Yongjoon , Lee Sang Joon , Kim Ki Hean 
Published: July 2014

ABSTRACTDynamic changes in the spatial distribution of chloroplasts are essential for optimizing photosynthetic capacity under changing light conditions. Light‐induced movement of chloroplasts has been widely investigated, but most studies were conducted on isolated tissues or protoplasts. In this study, a two‐photon microscopy (TPM) system was adapted to monitor the intracellular 3‐dimensional (3D) movements of chloroplasts in intact leaves of plants during dark to light transitions. The TPM imaging was based on autofluorescence of chlorophyll generated by a femto‐second Ti:Sapphire laser. All chloroplasts did not exhibit the same motion in response to irradiation variation. In the sub‐epidermal mesophyll cells, chloroplasts generally moved away from the surface following blue light treatment, however many chloroplasts did not show any movement. Such spatial heterogeneity in chloroplast motility underlines the importance of monitoring intracellular orientation and movement of individual chloroplasts across intact leaves. Our investigation shows that the 3D imaging of chloroplasts using TPM can help to understand the changes in local photosynthetic capacity in intact leaves under changing environmental conditions. Microsc. Res. Tech. 77:806–813, 2014. © 2014 Wiley Periodicals, Inc.
Current approaches in evolution: From molecules to cells and organisms
Authors: Thattai Mukund , Peisajovich Sergio G. 
Published: July 2014

ABSTRACTThis is an exciting time to be an evolutionary biologist. Indeed, it is difficult to keep up with all the studies that fall under the broad category of “Evolution” since they span species, traits, and scales of organization. This special issue gives a flavor of exciting new approaches in evolutionary biology, but also emphasizes universal themes. The reviews contained here discuss important aspects of molecular evolution at multiple scales, from individual proteins to complex regulatory networks, as well as from unicellular organisms to macroscopic traits in animals. Though the model systems are diverse, the issues addressed are fundamental: the origin of evolutionary novelties, and the forces that drive them to fixation. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 465–467, 2014. © 2014 Wiley Periodicals, Inc.