bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental and Computational Studies on the Iridium Activation of Aliphatic and Aromatic CH Bonds of Alkyl Aryl Ethers and Related Molecules
Authors: Lara Patricia , Paneque Margarita , Poveda Manuel L. , Santos Laura L. , Valpuesta José E. V. , Carmona Ernesto , Moncho Salvador , Ujaque Gregori , Lledós Agustí , Álvarez Eleuterio , Mereiter Kurt 
Published: August 2009

AbstractReaction of the IrIII complex [(TpMe2)Ir(C6H5)2(N2)] (1⋅N2) with ortho‐cresol (2‐methylphenol) occurs with cleavage of the OH and two C(sp3)H bonds of the phenol and formation of the electrophilic hydride alkylidene derivative [(TpMe2)Ir(H){C(H)C6H4‐o‐O}] (2). The analogous reaction of 2‐ethylphenol gives a related product 3. Both 2 and 3 have been shown to be identical to the minor, unidentified products of the already reported reactions of 1 with anisole and phenetole, respectively. Thus, in addition to the route that leads to the known heteroatom‐stabilized hydride carbene [(TpMe2)Ir(H){C(H)OC6H4‐ o‐}] (B), anisole can react with 1 with cleavage of the OCH3 bond and formation of a new carbon–carbon bond. In contrast, only CH bond‐activation products with structures akin to B result from 1⋅N2 and 3,5‐dimethylanisole (complex 8) or 4‐fluoroanisole (9). Using anisole as a model, a computational study of the triple CH bond activation (two aliphatic CH bonds plus an ortho‐metalation reaction) that is responsible for the formation of these heteroatom‐stabilized hydride carbenes has been undertaken.
A Double Plug–Socket System Capable of Molecular Keypad Locks through Controllable Photooxidation
Authors: Jiang Wei , Han Min , Zhang Heng‐Yi , Zhang Zhi‐Jun , Liu Yu 
Published: August 2009

AbstractTwo robust divalent complexes have been successfully constructed by using complementary rigid spacers (anthracene vs. 1,4,5,8‐naphthalenediimide (NDI)) and two pairs of [24]crown‐8 ethers and secondary dialkylammonium functionalities as binding motifs. It was demonstrated that properly selected, rigid spacers are more efficient than flexible ones for achieving strong multivalent association. This is presumably due to the preorganization of the rigid spacers, the cooperation between charge‐transfer interactions of rigid spacers, and the complexation of the binding motifs. Furthermore, the intermolecular photoinduced electron transfer (PET) between rigid spacers in these robust complexes could be switched on and off by modulating their complexation through acid–base reactions, which is reminiscent of a plug–socket system capable of electron transfer. In addition, the self‐sensitized photooxidation of the divalent host with anthracene as a spacer can be completely inhibited after complexation with the divalent guests that contain NDI as spacers. This process could also be understood by invoking intermolecular PET and could be turned on and off through acid–base reactions. The photophysical and photochemical properties of these robust complexes have been interpreted as molecular keypad locks with alarm systems. Thus, a double plug–socket system and molecular keypad locks were successfully integrated inside robust multivalent systems and then the normal molecular devices were endowed with logic functions.
Remarkable Substituent Effects on the Activation Energy of Silylene Insertion into Silicon–Chlorine Bonds
Authors: Xu Zheng , Jin Juan , Li Zhifang , Qiu Huayu , Jiang Jianxiong , Lai Guoqiao , Kira Mitsuo 
Published: August 2009

AbstractInsertion reactions of dimethylsilylene (Me2Si:) into the silicon–chlorine bond of various substituted chlorosilanes have been computationally studied by using DFT calculations with a 6‐31++G(d,p) basis set. All of the insertions investigated herein were exothermic (more than 40 kcal mol−1) and proceeded via three‐membered cyclic transition states (TS) with one substituent of a chlorosilane in the ring plane and two other substituents out of the plane. Among the two possible concerted insertion pathways, the pathway via a TS with a silylene lone‐pair orbital approaching a chlorosilane silicon atom was preferred. Important nucleophilic interactions of silylene lone‐pair orbitals with anti‐bonding σ orbitals of SiY (in plane) were supported by carrying out a natural bond orbital (NBO) analysis of the reaction. A radical pathway through the initial abstraction of chlorine from chlorosilane by the silylene cannot compete with the preferred concerted pathway. Systematic calculations for SiMe2 insertion into various chlorosilanes (YR2SiCl; Y (in‐plane substituent)=H, Me, NH2, OH, F, SiH3, PH2, SH and Cl; R (out‐of‐plane substituent)=H, Me, iPr and tBu) have revealed remarkable substituent effects on activation free energies (ΔG≠). In‐plane (Y) substituent effects were mostly electronic. Electron‐withdrawing substituents accelerate the insertion through enhanced nucleophilic interaction between silylene lone‐pair orbitals with the σ*(SiY) orbital at the TS. The ΔG≠ values correlate with the σI constants as a scale of the inductive effect of Y. Out‐of‐plane (R) substituent effects are mainly steric, and bulky substituents increase the activation free energy . Correlation of the ΔG≠ values with Taft’s steric substituent constants (Es) was observed. There was no significant difference in the out‐of‐plane substituent effects between the electron‐withdrawing Cl and the electron‐donating Me groups.
Gerührt oder geschüttelt? James‐Bond‐Cocktail
Authors: Eckelmann Jens , Lüning Ulrich 
Published: August 2009

AbstractAusgehend von Perfluorheptan, gesättigter wässriger Kaliumcarbonatlösung, Methanol, Toluol und geeigneten Farbstoffen wird eine zunächst dreiphasige Mischung hergestellt, die sich nach Schütteln – nicht nur Rühren – in vier Phasen trennt. Zugabe von Pentan kehrt die Reihenfolge zweier Phasen um. Die Zugabe der Komponenten erfolgt über einen neu entwickelten Weg, und die gewählte Art der Durchmischung verdeutlicht dem Zuschauer die Komplexität mehrphasiger Lösungen.
Wie Mäuse Gefahr wittern
Authors: Groß Michael 
Published: August 2009

AbstractSäugetiere haben in ihren Nasen mindestens zwei Arten von Molekülsensoren. Die einen dienen dem Geruchssinn, und damit vor allem der Nahrungssuche, die anderen der Erkennung von Pheromonen von Artgenossen, und damit vor allem der sozialen und sexuellen Interaktion. Nun haben Forscher jedoch bei der Maus eine “dritte Nase” entdeckt, welche es den Nagern ermöglicht, Gefahrenquellen wie Krankheitserreger und kranke Artgenossen zu wittern.
Increase of intracellular Ca2+ by P2Y but not P2X receptors in cultured cortical multipolar neurons of the rat
Authors: Fischer Wolfgang , Nörenberg Wolfgang , Franke Heike , Schaefer Michael , Illes Peter 
Published: August 2009

AbstractThe expression and functionality of P2X/P2Y receptor subtypes in multipolar nonpyramidal neurons of mixed cortical cell cultures were investigated by means of immunocytochemistry and fura‐2 microfluorimetry. The morphological studies revealed that most of the neurons are immunoreactive for GABA and express a range of P2X/P2Y receptors, predominantly of the P2X2,4,6 and P2Y1,2 subtypes. P2X1 and P2X7 receptor immunoreactivity (IR) was found on thin axon‐like processes and presynaptic structures, respectively. Application of ATP caused a small concentration‐dependent increase in intracellular Ca2+ concentration ([Ca2+]i) in most investigated neurons, whereas only about the half of these cells responded to 2′,3′‐O‐(benzoyl‐4‐benzoyl)‐ATP (BzATP), ADPβS, 2MeSADP, or 2‐MeSATP and even fewer cells to UTP. In contrast, α,β‐meATP, UDP, and UDP‐glucose failed to produce any [Ca2+]i signaling. The response to ATP itself was inhibited by pyridoxal‐5′‐phosphate‐6‐azophenyl‐2′,4′‐disulfonic acid (PPADS), Reactive Blue 2, 2′‐deoxy‐N6‐methyl adenosine 3′,5′‐diphosphate (MRS2179), and suramin (300 μM) as well as by a cyclopiazonic acid‐induced depletion of intracellular Ca2+ stores. A Ca2+‐free external medium tended to decrease the ATP‐induced [Ca2+]i transients, although this action did not reach statistical significance. Various blockers of voltage‐sensitive Ca2+ channels and the gap junction inhibitor carbenoxolone did not interfere with the effect of ATP, whereas a combination of the ionotropic glutamate receptor antagonists D(–)‐2‐amino‐5‐phosphonopentanoic acid (AP5) and 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione disodium (CNQX) decreased it. Cross‐desensitization experiments between ADPβS or UTP and ATP suggested that ATP acts on the one hand via P2Y1,2 receptors and on the other hand by additional signaling mechanisms. These mechanisms may involve the release of glutamate (which in consequence activates ionotropic glutamate receptors) and the entry of Ca2+ via store‐operated Ca2+ channels. Evidence for the presence of functional P2X receptors, in particular P2X7, remains elusive. J. Comp. Neurol. 516:343–359, 2009. © 2009 Wiley‐Liss, Inc.
Comparison of color vision models based on spectral color representation
Authors: Jetsu Tuija , Heikkinen Ville , Pogosova Anahit , Jaaskelainen Timo , Parkkinen Jussi 
Published: August 2009

AbstractRecent break‐throughs in retinal imaging have raised new questions for color vision research, and the existing color vision models should be re‐evaluated. Many color vision models are based on an assumption that there are no differences in the detection phase, neither in the spatial configuration nor in the spectral sensitivities of cells. In this article, we have run experiments with four different color vision models. This evaluation gives us more knowledge about the essential properties of the models. We show how the tested color vision models are able to replicate the behaviour of human color vision by evaluating their performance in Farnsworth‐Munsell 100‐Hue color vision test. Also, the wavelength discrimination power of each model is presented and the properties of color spaces spanned by models are examined using samples from Munsell Book of Color. Our experiments show that there are large differences in the properties of different models. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 341–350, 2009
Analyzing the metrics of the perceptual space in a new multistage physiological colour vision model
Authors: Chorro Elísabet , Martínez‐Verdú Francisco Miguel , de Fez Dolores , Capilla Pascual , Luque Maria José 
Published: August 2009

AbstractIn this work, the metric of a new multistage colour vision model, ATTD05, is assessed and a new colour difference formula is suggested. Firstly, the uniformity of the ATTD05 colour space was compared with that of CIECAM02 for some Munsell samples, because if the model yields a uniform perceptual space, we will be able to implement a colour difference formula as a Euclidian distance between two points. Secondly, we developed a new space based on the perceptual descriptors of the model: brightness, hue, colourfulness, and saturation. After that, we calculated the free parameters of the space that better fit the measured and experimental data of two datasets (small‐magnitude and large‐magnitude colour differences), by minimizing the performance factor (PF/3). Finally, we compare colour differences calculated for ATTD05 and for other models. The PF/3 and the STRESS parameters were used to decide which model predicts better perceptual differences and, therefore, which model was the more uniform. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 359–366, 2009
Statistically q‐deformed and tau‐deformed systems
Authors: Badescu Viorel , Landsberg Peter 
Published: August 2009

AbstractTwo classes of statistically deformed systems are known in literature. They are, respectively, the q‐deformed systems (Lavagno and Narayana Swamy, Phys Rev E 2002, 65, 036101) and the κ‐deformed systems (Kaniadakis and Scarfone, Physica A 2002, 305, 69). In this article, a new class, i.e., the tau‐deformed systems, is introduced. For each of these systems, a consistent thermodynamics may be developed. A summary of the main similarities between the thermodynamic properties of q‐deformed and tau‐deformed systems is presented. The deformation outlined in this article is radically different from the nonextensive Tsallis statistics, where the structure of the entropy is rather arbitrary deformed via the logarithmic function. In contrast, the theory of tau‐deformed systems is developed on a purely physical basis. However, one finally shows that the tau‐systems may be described by using a new form of deformed logarithmic function. © 2009 Wiley Periodicals, Inc. Complexity, 2010
Atomic Layer Deposition of NiO by the Ni(thd)2/H2O Precursor Combination
Authors: Lindahl Erik , Ottosson Mikael , Carlsson Jan‐Otto 
Published: August 2009

AbstractPolycrystalline nickel oxide is deposited on SiO2 substrates by alternating pulses of bis(2,2,6,6‐tetramethylheptane‐3,5‐dionato)nickel(II) (Ni(thd)2) and H2O. The deposition process shows atomic layer deposition (ALD) characteristics with respect to the saturation behavior of the two precursors at deposition temperatures up to 275 °C. The growth of nickel oxide is shown to be highly dependent on surface hydroxide groups, and a large excess of H2O is required to achieve saturation. Throughout the deposition temperature range the amount of carbon in the film, originating from the metal precursor ligand, is in the range 1–2%. Above 275 °C ALD growth behavior is lost in favor of thermal decomposition of the metal precursor. The initial nucleation process is studied by atomic force microscopy (AFM) and reveals nucleation of well‐separated grains which coalesce to a continuous film after about 250 ALD cycles.
Flow cytometric detection of Pig‐A mutant red blood cells using an erythroid‐specific antibody: Application of the method for evaluating the in vivo genotoxicity of methylphenidate in adolescent rats
Authors: Dobrovolsky Vasily N. , Boctor Sherin Y. , Twaddle Nathan C. , Doerge Daniel R. , Bishop Michelle E. , Manjanatha Mugimane G. , Kimoto Takafumi , Miura Daishiro , Heflich Robert H. , Ferguson Sherry A. 
Published: August 2009

AbstractA modified flow cytometry assay for Pig‐A mutant rat red blood cells (RBCs) was developed using an antibody that positively identifies rat RBCs (monoclonal antibody HIS49). The assay was used in conjunction with a flow cytometric micronucleus (MN) assay to evaluate gene mutation and clastogenicity/aneugenicity in adolescent male and female rats treated with methylphenidate hydrochloride (MPH). Sprague‐Dawley rats were treated orally with 3 mg/kg MPH (70/sex) or water (40/sex) 3 × /day on postnatal days (PNDs) 29–50. Eight additional rats (4/sex) were injected i.p. with N‐ethyl‐N‐nitrosourea (ENU) on PND 28. Blood was collected on PNDs 29, 50, and 90, and used for determining serum MPH levels and/or conducting genotoxicity assays. On the first and last days of MPH treatment (PNDs 29 and 50), serum MPH levels averaged 21 pg/μl, well within the clinical treatment range. Relative to our previously published method (Miura et al. [2008]; Environ Mol Mutagen 49: 614–629), the HIS49 Pig‐A mutation assay significantly reduced the background RBC mutant frequency; in the experiments with ENU‐treated rats, the modification increased the overall sensitivity of the assay 2–3 fold. Even with the increased assay sensitivity, the 21 consecutive days of MPH treatment produced no evidence of Pig‐A mutation induction (measured at PND 90); in addition, MPH treatment did not increase MN frequency (measured at PND 50). These results support the consensus view that the genotoxicity of MPH in pediatric patients reported earlier (El‐Zein et al. [2005]: Cancer Lett 230: 284–291) cannot be reproduced in animal models, suggesting that MPH at clinically relevant levels may be nongenotoxic in humans. Environ. Mol. Mutagen. 2010. Published 2009 by Wiley‐Liss, Inc.
On the development of a triple‐preserving Maxwell's equations solver in non‐staggered grids
Authors: Sheu Tony W. H. , Hung Y. W. , Tsai M. H. , Chiu P. H. , Li J. H. 
Published: August 2009

AbstractWe present in this paper a finite difference solver for Maxwell's equations in non‐staggered grids. The scheme formulated in time domain theoretically preserves the properties of zero‐divergence, symplecticity, and dispersion relation. The mathematically inherent Hamiltonian can be also retained all the time. Moreover, both spatial and temporal terms are approximated to yield the equal fourth‐order spatial and temporal accuracies. Through the computational exercises, modified equation analysis and Fourier analysis, it can be clearly demonstrated that the proposed triple‐preserving solver is computationally accurate and efficient for use to predict the Maxwell's solutions. Copyright © 2009 John Wiley & Sons, Ltd.
Numerical analysis of the effect of boundary layer thickness on vortex structures and heat transfer in the wake behind a hill
Authors: Yanaoka Hideki , Inamura Takao , Suenaga Yosuke , Abe Keisuke 
Published: August 2009

AbstractThis study presents a three‐dimensional numerical analysis of the effect of boundary layer thickness on vortex structures and heat transfer behind a hill mounted in a laminar boundary layer. When the thickness of the velocity boundary layer is comparable to the hill height, a hairpin vortex is formed symmetrically to the center of the spanwise direction in the wake. A secondary vortex is formed between the legs, and horn‐shaped secondary vortices appear under the concave parts of the hairpin vortex. When the boundary layer thickness increases, the legs and horn‐shaped secondary vortices move toward the center of the spanwise direction, and thus heat transport and heat transfer increase there. At this time, high‐turbulence areas generated locally move toward the center of the spanwise direction with an increase in the boundary layer thickness. With a further increase in the boundary layer thickness, steady streamwise vortices are formed downstream of the hill, but the heat transfer decreases. © 2009 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20261
Processing of type I collagen gels using nonenzymatic glycation
Authors: Roy Rani , Boskey Adele , Bonassar Lawrence J. 
Published: August 2009

AbstractThis study focuses on the development of a novel method of nonenzymatic glycation of fibrillar collagen gels. In contrast to previous studies in which type I collagen gels were glycated in the solid state, this study presents a method for glycation in solution. The type I collagen in solution or gels was exposed to a range of ribose concentrations from 0 to 250 mM. The binding of ribose to collagen was documented using Fourier transform infrared (FTIR) spectroscopy. formation of advanced glycation end products (AGEs) was quantified by fluorescence measurement. The bulk compressive modulus and viscoelastic time constant of processed gels were determined in stress relaxation studies. Both methods of glycation enhanced ribose addition and AGE formation in a dose‐dependent manner, with glycation in the gel state being more efficient. Both methods enhanced mechanical properties similarly, with 250 mMribose treatment resulting in a 10‐fold increase in bulk modulus. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
The simplicity of males: Dwarf males of four species of Osedax (Siboglinidae; Annelida) investigated by confocal laser scanning microscopy
Authors: Worsaae Katrine , Rouse Greg W. 
Published: August 2009

AbstractDwarf males of the bone‐eating worms Osedax (Siboglinidae, Annelida) have been proposed to develop from larvae that settle on females rather than on bone. The apparent arrest in somatic development and resemblance of the males to trochophore larvae has been posited as an example of paedomorphosis. Here, we present the first investigation of the entire muscle and nervous system in dwarf males of Osedax frankpressi, O. roseus, O. rubiplumus, and O. “spiral” analyzed by multistaining and confocal laser scanning microscopy. Sperm shape and spermiogenesis, the sperm duct and internal and external ciliary patterns were likewise visualized. The males of all four species possess morphological traits typical of newly settled siboglinid larvae: a prostomium, a peristomium with a prototroch, one elongate segment and a second shorter segment. Each segment has a ring of eight long‐handled hooked chaetae. The longitudinal muscles are distributed as evenly spaced strands forming a grid with the thin outer circular muscles. Oblique protractor and retractor muscles are associated with each of the chaetal sacs. The nervous system comprises a cerebral ganglion, a prototroch nerve ring, paired dorsolateral longitudinal nerves, five ventral longitudinal nerves with paired, posterior ganglia and a terminal commissure, as well as a net of fine peripheral transverse plexuses surrounding the first segment. Internal ciliation occurs as paired ventrolateral bands along the first segment. The bands appear to lead the free mature sperm to a ciliated duct and seminal vesicle lying just behind the prototroch region. A duct then runs from the seminal vesicle into the dorsal part of the prostomium. The similarity of Osedax males to the larvae of Osedax and other siboglinid annelids as well as similarities shown here to the neuromuscular organization seen in other annelid larvae supports the hypothesis of paedomorphosis in males of Osedax. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.
Sulfur fertilization and light exposure during storage are critical determinants of the nutritional value of ready‐to‐eat friariello campano (Brassica rapa L. subsp. sylvestris)
Authors: Barbieri Giancarlo , Bottino Antonella , Orsini Francesco , De Pascale Stefania 
Published: August 2009

AbstractBACKGROUND: The nutritional value of fresh vegetables can be affected at different steps within the field‐to‐market pipeline. Both pre‐ and post‐harvest factors should be considered in order to increase the produce quality and to preserve it until final consumption. In this study the effects of sulfur nutrition during plant growth and light exposure during storage on the nutritional value of ready‐to‐eat friariello campano (Brassica rapa L. subsp. sylvestris L. Janch. var. esculenta Hort.) were studied.RESULTS: Fresh weight loss was higher in light‐storage treatment. During storage, light exposure reduced leaf nitrate content, although no effect could be attributed to sulfur nutrition. Sulfur increased both lipophilic and hydrophilic antioxidant activity. The hydrophilic antioxidant activity linearly decreased during storage, whereas the lipophilic activity increased over time. However, no differences could be attributed to light exposure during storage for this parameter. Results on colorimetric indexes and their relation with the chlorophyll content are also reported.CONCLUSIONS: Ready‐to‐eat friariello quality may be improved with an enhanced antioxidant activity and reduced nitrate content by combining, respectively, increased sulfur availability during plant growth and exposure to light during storage. On the other hand, light exposure caused a more rapid decline in produce fresh weight during storage. Copyright © 2009 Society of Chemical Industry
Galapagos: Darwin, evolution, and ENT
Authors: Bluestone Charles D. 
Published: August 2009

AbstractThis year is especially important in the history of the theory of evolution; 2009 is the bicentennial anniversary of the birth of Charles Darwin and the sesquicentennial anniversary of his publication, The Origin of Species. Darwin visited the Galapagos Islands as a young man, which greatly influenced his thinking. My son Jim and I had the good fortune to visit these islands in January 2009 and see firsthand what led Darwin to arrive at his monumental insights into the origins of life on this planet. I have described my observations and related some of this experience to the ear, nose, and throat, albeit with whimsy in several instances. Nonetheless, some of the adaptations in the animals on these unique islands may have bearing on my hypotheses related to the incidence and pathogenesis of otitis media in humans. It is hoped the reader will share my enthusiasm for the experience we had on these fantastic islands and tour them in the future. Laryngoscope, 2009