bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrothermal Synthesis of Na0.5La0.5TiO3–LaCrO3 Solid‐Solution Single‐Crystal Nanocubes for Visible‐Light‐Driven Photocatalytic H2 Evolution
Authors: Shi Jinwen , Ye Jinhua , Zhou Zhaohui , Li Mingtao , Guo Liejin 
Published: May 2011

AbstractCubic perovskite structure photocatalysts of Na0.5La0.5TiO3 and (Na0.5La0.5TiO3)1.00(LaCrO3)0.08 solid solution that consisted of well‐defined single‐crystal nanocubes were successfully prepared by means of facile and surfactant‐free hydrothermal reactions for the first time. The results from different instrumental characterizations and theoretical calculations consistently confirmed the formation of nanocubic single‐crystal solid solution of (Na0.5La0.5TiO3)1.00(LaCrO3)0.08, and clearly revealed the modification of its physicochemical properties compared with those of Na0.5La0.5TiO3. In particular, the effective narrowing of the bandgap (from 3.19 to 2.25 eV) by Cr3+ in the solid solution made it possible to utilize visible light. The solid‐solution configuration maintained the charge balance to preserve the valence of Cr3+ rather than Cr6+, and accommodated Cr3+ with high content to form new energy bands instead of localized impurity levels. The hydrothermal preparation strategy ensured the formation of single crystals with high purity, few defects, and regulated morphology; it also guaranteed the valences of Ti4+ and Cr3+ in the solid solution. Consequently, the recombination of photogenerated carriers could be effectively suppressed to benefit photocatalytic H2 evolution. (Na0.5La0.5TiO3)1.00(LaCrO3)0.08 nanocubic single‐crystal solid solution showed stable photocatalytic activity, and thus was proved to be a promising candidate for visible‐light‐driven photocatalytic H2 evolution.
Push–Pull Amino Succinimidyl Ester Thiophene‐Based Fluorescent Dyes: Synthesis and Optical Characterization
Authors: Sotgiu Giovanna , Galeotti Matteo , Samorí Cristian , Bongini Alessandro , Mazzanti Andrea 
Published: May 2011

AbstractThe design and synthesis of new fluorescent dyes with emission range at 490–650 nm are described. Their structural and electronic properties have been characterized by both experimental techniques and quantum‐chemical calculations. The chromophores are donor–π‐bridge–acceptor push–pull compounds with a π bridge of phenyl and thiophene rings and their combination. Compared with previous thiophene fluorophores, these dyes show significant redshift in the absorption and emission spectra and offer compact, red‐emitting fluorophores. The dyes have amino succinimidyl active ester and can be readily conjugated to proteins, polymers and other amino‐group‐containing materials.
Synthesis of 5‐Acetyloxazoles and 1,2‐Diketones from β‐Alkoxy‐β‐ketoenamides and Their Subsequent Transformations
Authors: Lechel Tilman , Gerhard Markus , Trawny Daniel , Brusilowskij Boris , Schefzig Luise , Zimmer Reinhold , Rabe Jürgen P. , Lentz Dieter , Schalley Christoph A. , Reissig Hans‐Ulrich 
Published: May 2011

AbstractLithiated alkoxyallenes, nitriles, and carboxylic acids have been employed as precursors in a three‐component reaction leading to highly substituted β‐alkoxy‐β‐ketoenamides. Upon treatment with trifluoroacetic acid, these enamides could be easily cyclized to 5‐acetyloxazole derivatives. The synthesis is very flexible with respect to the substitution pattern at C‐2 and C‐4 of the oxazole core. A mechanistic suggestion for the oxazole formation is presented on the basis of 18O‐labeled compounds and their mass spectrometric analysis. In several cases, 1,2‐diketones are formed as side products or even as major components. The acetyl moiety at C‐5 of the oxazole derivatives can efficiently be converted into alkenyl or alkynyl moieties, which allows a multitude of subsequent reactions. Condensation reactions of the acetyl group provided the expected oxime or hydrazone. By applying a Fischer reaction, the phenylhydrazone could be transferred into an indole, which emphasizes the potential of 5‐acetyloxazoles for the preparation of highly substituted (poly)heterocyclic systems. The alkynyl group at C‐2 is prone to addition reactions, providing an enamine with interesting photophysical properties. Sonogashira couplings were performed with 5‐alkynyl‐substituted oxazoles, furnishing the expected aryl‐substituted products. This alkynyl unit was employed for the preparation of a new, star‐shaped trisoxazole derivative. The ability of this multivalent compound to form self‐assembled monolayers between the basal plane of highly oriented pyrolytic graphite and 1‐phenyloctane was demonstrated by scanning tunneling microscopy (STM). The star‐shaped compound seems to prefer the C3‐symmetric arrangement in this two‐dimensional crystal. Two 1,2‐diketones were smoothly converted into functionalized quinoxaline derivatives.
Frequency‐Domain Fourier‐Transform Terahertz Spectroscopy of the Single‐Molecule Magnet (NEt4)[Mn2(5‐Brsalen)2(MeOH)2Cr(CN)6]
Authors: Dreiser Jan , Schnegg Alexander , Holldack Karsten , Pedersen Kasper S. , Schau‐Magnussen Magnus , Nehrkorn Joscha , Tregenna‐Piggott Philip , Mutka Hannu , Weihe Høgni , Bendix Jesper , Waldmann Oliver 
Published: May 2011

AbstractWe have investigated the novel single‐molecule magnet (NEt4)[Mn2(5‐Brsalen)2(MeOH)2Cr(CN)6] (1; 5‐Brsalen=N,N′‐ethylenebis(5‐bromosalicylidene)iminato anion) using spectroscopic as well as magnetization and susceptibility measurements. Frequency‐domain Fourier‐transform terahertz electron paramagnetic resonance (FDFT THz‐EPR) based on the generation of THz radiation from a synchrotron in combination with inelastic neutron scattering (INS) allows for the discrimination between intermultiplet and intramultiplet transitions. Together with ac/dc magnetic susceptibility measurements the obtained set of data provides a complete characterization of the lowest energetic magnetic excitations. We find that the new compound 1 exhibits much weaker intermolecular interactions than found in the closely related compound: K[Mn2(5‐Brsalen)2(H2O)2Cr(CN)6] (2). Furthermore, two phonon lines in the vicinity of the magnetic excitations are detected.
A quantitative measure of chirality inside nucleic acid databank
Authors: Pietropaolo Adriana , Parrinello Michele 
Published: May 2011

AbstractWe show the capability of a chirality index (Pietropaolo et al., Proteins 2008;70:667–677) to investigate nucleic acid structures because of its high sensitivity to helical conformations. By analyzing selected structures of DNA and RNA, we have found that sequences rich in cytosine and guanine have a tendency to left‐handed chirality, in contrast to regions rich in adenine or thymine which show strong negative, right‐handed, chirality values. We also analyze RNA structures, where specific loops and hairpin motifs are characterized by a well‐defined chirality value. We find that in nucleosome the chirality is exalted, whereas in ribosome it is reduced. Our results illustrate the sensitivity of this descriptor for nucleic acid conformations. Chirality 2011. © 2011 Wiley‐Liss, Inc.
Conversions of Cellobiose and Inulin to Deoxyfructosazine in Aqueous Solutions
Authors: Wu Suxiang , Fan Honglei , Zhang Qian , Cheng Yan , Wang Qian , Yang Guanying , Han Buxing 
Published: May 2011

AbstractThe conversion of the biomass into high value‐added chemicals is an attractive topic in green chemistry. In this work, we studied the synthesis of 2,6‐deoxyfructosazine (2,6‐DOF) and 2,5‐deoxyfructosazine (2,5‐DOF) from cellobiose and inulin, respectively, in aqueous solution by an one‐pot two‐step route. In this method, cellobiose or inulin was first hydrolyzed into glucose or fructose and then reacted directly with ammonium formate to form 2,6‐DOF or 2,5‐DOF. The effects of reaction temperature, reaction time, pH value on the yields of the products were studied. It was demonstrated that the cellobiose and inulin could be converted to 2,6‐DOF and 2,5‐DOF effectively at optimized condition.
Inputs to the midbrain dopaminergic complex in the rat, with emphasis on extended amygdala‐recipient sectors
Authors: Zahm Daniel S. , Cheng Anita Y. , Lee Tristan J. , Ghobadi Comeron W. , Schwartz Zachary M. , Geisler Stefanie , Parsely Kenneth P. , Gruber Clemens , Veh Ruediger W. 
Published: May 2011

AbstractThe midbrain dopaminergic neuronal groups A8, A9, A10, and A10dc occupy, respectively, the retrorubral field (RRF), substantia nigra compacta (SNc), ventral tegmental area (VTA), and ventrolateral periaqueductal gray (PAGvl). Collectively, these structures give rise to a mixed dopaminergic and nondopaminergic projection system that essentially permits adaptive behavior. However, knowledge is incomplete regarding how the afferents of these structures are organized. Although the VTA is known to receive numerous afferents from cortex, basal forebrain, and brainstem and the SNc is widely perceived as receiving inputs mainly from the striatum, the afferents of the RRF and PAGvl have yet to be assessed comprehensively. This study was performed to provide an account of those connections and to seek a better understanding of how afferents might contribute to the functional interrelatedness of the VTA, SNc, RRF, and PAGvl. Ventral midbrain structures received injections of retrograde tracer, and the resulting retrogradely labeled structures were targeted with injections of anterogradely transported Phaseolus vulgaris leucoagglutinin. Whereas all injections of retrograde tracer into the VTA, SNc, RRF, or PAGvl produced labeling in many structures extending from the cortex to caudal brainstem, pronounced labeling of structures making up the central division of the extended amygdala occurred following injections that involved the RRF and PAGvl. The anterograde tracing supported this finding, and the combination of retrograde and anterograde labeling data also confirmed reports from other groups indicating that the SNc receives robust input from many of the same structures that innervate the VTA, RRF, and PAGvl. J. Comp. Neurol. 519:3159–3188, 2011. © 2011 Wiley‐Liss, Inc.
Assembly properties of lamprey neurofilament subunits and their expression after spinal cord transection
Authors: Zhang Guixin , Jin Liqing , Selzer Michael E. 
Published: May 2011

AbstractIn mammals neurofilaments (NF) are formed by coassembly of three subunits: NFL, NFM, and NFH (light, medium, and heavy). It had been believed that lampreys have only one subunit, NF180. However, a previous study showed that NF180 could not self‐assemble but could coassemble with rat NFL, suggesting the existence of additional NF subunits in lamprey. More recently, we cloned three additional NF subunits. These new subunits and NF180 have now been transfected in combinations into SW13cl.2Vim− cells, which lack endogenous cytoplasmic intermediate filaments. None of the subunits could self‐assemble. No combination of NF subunits could form filaments in the absence of lamprey NFL (L‐NFL). Assembly occurred at 28°C, but not at 37°C. L‐NFL could form thick NF bundles with NF180 but not with NF132 and NF95, which formed only fine filamentous arrays. To determine which parts of the NF subunits are required for filament or bundle formation, we constructed deletion mutants of NF180 and cotransfected them with L‐NFL. As with mammalian NF, only constructs with intact head and core domains could form filaments with L‐NFL. However, the full length of NF180 was required to form NF bundles. As with NF180, in situ hybridization indicated that mRNA for L‐NFL and NF132 was downregulated in identified reticulospinal neurons by 5 weeks after spinal cord transection, but was reexpressed at 10 weeks selectively in those neurons whose axons have a high probability of regenerating. This is consistent with a possible role of NFs in the mechanism of axon regeneration. J. Comp. Neurol. 519:3657–3671, 2011. © 2011 Wiley‐Liss, Inc.
Subcellular localization of patched and smoothened, the receptors for sonic hedgehog signaling, in the hippocampal neuron
Authors: Petralia Ronald S. , Schwartz Catherine M. , Wang Ya‐Xian , Mattson Mark P. , Yao Pamela J. 
Published: May 2011

AbstractCumulative evidence suggests that, aside from patterning the embryonic neural tube, Sonic hedgehog (Shh) signaling plays important roles in the mature nervous system. In this study, we investigate the expression and localization of the Shh signaling receptors, Patched (Ptch) and Smoothened (Smo), in the hippocampal neurons of young and mature rats. Reverse transcriptase‐polymerase chain reaction and immunoblotting analyses show that the expression of Ptch and Smo remains at a moderate level in young postnatal and adult brains. By using immunofluorescence light microscopy and immunoelectron microscopy, we examine the spatial distribution of Ptch and Smo within the hippocampal neurons. In young developing neurons, Ptch and Smo are present in the processes and are clustered at their growth cones. In mature neurons, Ptch and Smo are concentrated in dendrites, spines, and postsynaptic sites. Synaptic Ptch and Smo often co‐exist with unusual structures—synaptic spinules and autophagosomes. Our results reveal the anatomical organization of the Shh receptors within both the young and the mature hippocampal neurons. J. Comp. Neurol. 519:3684‐3699, 2011. ©2011 Wiley‐Liss, Inc.
Redox‐Responsive Rhodocenium [O,O]‐, [N,O]‐, [N,N]‐, and [N,C,N]‐Metalloligands
Authors: Eisenstecken Daniela , Enk Barbara , Kopacka Holger , Wurst Klaus , Müller Thomas , Pevny Florian , Winter Rainer F. , Bildstein Benno 
Published: May 2011

AbstractAs we have recently shown, the doubly substituted [1,2‐O,O]H, [1,2‐O,N]H, [1,2‐N,N]H, and [1,3‐N,N]H pentafulvenes are convenient N/O‐functionalized cyclopentadienide (Cp) precursors. Deprotonation of the pentafulvenes by potassium hydride followed by reaction with [Cp*RhCl2]2 or [Cp*IrCl2]2 gave access to the first functionalized rhodocenium and iridocenium salts that contain two acyl and/or imidoyl substituents. These air‐stable compounds represent interesting bis(acyl/imidoyl) or mixed acyl/imidoyl metalloligand systems that combine an axially shielding, electrochemically active metallocene moiety with directly attached, conjugating oxygen and/or nitrogen donor sites. The structural properties of these novel metallocene metalloligands in solution and in the solid state were studied by NMR spectroscopy (1H, 13C, 103Rh) and by single‐crystal structure analysis. The electrochemical investigations on complexes 5a, 6b, and 7a showed the effect of the appended functional groups on the potential and on the reversibility of the rhodocenium/rhodocene reduction and provided evidence for the dimerization that followed the reduction. Further redox processes that were due to the heteroatom functions included the stepwise reduction of the 1,2‐diketo entity of 5a and the oxidation of the 1,2‐diimino moiety of 7a.
Electrochemical Studies of Ochratoxin A Mycotoxin at Gold Electrodes Modified with Cysteamine Self‐Assembled Monolayers. Its Ultrasensitive Quantification in Red Wine Samples
Authors: Perrotta Patricio René , Vettorazzi Nelio Roberto , Arévalo Fernando Javier , Granero Adrián Marcelo , Chulze Sofía Noemí , Zón María Alicia , Fernández Héctor 
Published: May 2011

AbstractThe quantification of ochratoxin A is studied at cysteamine self‐assembled monolayer modified gold electrodes in red wine samples by square wave voltammetry. Detection and quantification limits of 0.004 µg L−1 and 0.012 µg L−1, respectively, were determined. The recovery percentages were in the range from 146 % to 94.0 % at spiking levels ranging from 0.02 to 5 µg L−1. The variation coefficients for within‐laboratory repeatability varied from 31.4 to 11.5 % for spiked level from 0.02 to 2.0 µg L−1. The developed electrochemical method is efficient, reproducible, and ultrasensitive for the quantification of OTA in red wine samples.
Alcohol diagnoses among older Tennessee Medicare beneficiaries: race and gender differences
Authors: Kilbourne Barbara Jean , Cummings Sherry M. , Levine Robert 
Published: May 2011

BackgroundThese analyses bolster a sparse body of research focusing on the rate of alcohol disorders among older adults, particularly race and gender subgroups.MethodsWe based the study on cross‐sectional data from all Medicare billed physician/patient encounters. Analyses of these data included cross‐tabulations, difference of means tests, and difference of proportions tests, logistic regression and multinomial logistic regression. These analyses were based Medicare billing records from physician/patient encounters in Tennessee. Data included Tennessee Medicare billings beneficiaries enrolled in Medicare Part B, who saw a physician at least once in 2000. Patients with billings containing ICD‐9 codes: 303 (alcohol abuse), 305 (alcohol dependence), 291 (alcohol psychosis), or 571.1‐571.3 (alcohol‐related liver disease including cirrhosis of the liver) as to primary diagnosis were considered alcohol‐disordered.ResultsAnalyses reveal the overall rate of alcohol disorders, subgroup variation in rates and differences in pattern of specific disorders. Merely 0.04% of Tennessee Medicare beneficiaries were diagnosed with any type of alcoholism, a rate much lower than those reported in previous studies. Rates of alcohol disorders varied across groups, with significantly higher rates for Black men. The type alcohol disorder also varied across groups.ConclusionsMany encounters with the medical system result in missed opportunities to identify and treat alcohol disorders, a significant risk factor among older adults. Alcoholism both triggers and exacerbates many chronic conditions among older adults. The earlier in the disease trajectory the more of these conditions could be prevented or more efficiently managed, resulting in substantial savings in health care costs. Copyright © 2011 John Wiley & Sons, Ltd.
White matter integrity and behavioral activation in healthy subjects
Authors: Xu Jiansong , Kober Hedy , Carroll Kathleen M. , Rounsaville Bruce J. , Pearlson Godfrey D. , Potenza Marc N. 
Published: May 2011

AbstractIndividual differences in behavioral inhibition and behavioral activation may place certain people at greater risk for neuropsychiatric disorders and engagement in risky behaviors. Therefore, studying the neural correlates of behavioral inhibition and activation may help us understand neural mechanisms underlying risk behaviors in both clinical and non‐clinical populations. To investigate, we assessed the relationships between white matter integrity and measures of behavioral inhibition and behavioral activation in 51 healthy participants using diffusion tensor imaging (DTI) and the Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) scale. Scores on the Fun‐Seeking subscale of the BAS positively correlated with DTI fractional anisotropy in the left corona radiata and adjacent superior longitudinal fasciculus, and with mean diffusivity in the left inferior longitudinal fasciculus and inferior fronto‐occipital fasciculus after controlling for age, gender, and education. These findings suggest that the integrity of white matter connecting extensive brain regions implicated in self‐control and the processing of rewards and emotions are associated with individual differences in the motivation for seeking and participating in fun and novel experiences. Hum Brain Mapp , 2012. © 2011 Wiley Periodicals, Inc.
sLORETA allows reliable distributed source reconstruction based on subdural strip and grid recordings
Authors: Dümpelmann Matthias , Ball Tonio , Schulze‐Bonhage Andreas 
Published: May 2011

AbstractSource localization based on invasive recordings by subdural strip and grid electrodes is a topic of increasing interest. This simulation study addresses the question, which factors are relevant for reliable source reconstruction based on sLORETA. MRI and electrode positions of a patient undergoing invasive presurgical epilepsy diagnostics were the basis of sLORETA simulations. A boundary element head model derived from the MRI was used for the simulation of electrical potentials and source reconstruction. Focal dipolar sources distributed on a regular three‐dimensional lattice and spatiotemporal distributed patches served as input for simulation. In addition to the distance between original and reconstructed source maxima, the activation volume of the reconstruction and the correlation of time courses between the original and reconstructed sources were investigated. Simulations were supplemented by the localization of the patient's spike activity. For noise‐free simulated data, sLORETA achieved results with zero localization error. Added noise diminished the percentage of reliable source localizations with a localization error ≤15 mm to 67.8%. Only for source positions close to the electrode contacts the activation volume correctly represented focal generators. Time‐courses of original and reconstructed sources were significantly correlated. The case study results showed accurate localization. sLORETA is a distributed source model, which can be applied for reliable grid and strip based source localization. For distant source positions, overestimation of the extent of the generator has to be taken into account. sLORETA‐based source reconstruction has the potential to improve the localization of distributed generators in presurgical epilepsy diagnostics and cognitive neuroscience. Hum Brain Mapp , 2011. © 2011 Wiley‐Liss, Inc.
Overnight deprivation from smoking disrupts amygdala responses to fear
Authors: Onur Oezguer A. , Patin Alexandra , Mihov Yoan , Buecher Boris , Stoffel‐Wagner Birgit , Schlaepfer Thomas E. , Walter Henrik , Maier Wolfgang , Hurlemann René 
Published: May 2011

AbstractCigarette smoking, a major, yet avoidable, cause of disability and premature death, is the most prevalent form of nicotine addiction. An emerging theme in the neurobiology of nicotine addiction is the integrity of the amygdala. Using functional MRI, amygdala responses during a face perception task were compared between 28 chronic smokers [14 females, 14 males; age, 26.3 (2.8) years; age at onset of smoking, 15.8 (2.6) years; years smoked, 9.1 (2.1); cigarettes per day, 17.1 (3.7); Fagerström test for nicotine dependence score, 4.1 (1.9); exhaled carbon‐monoxide level, 17.8 (9.5) ppm] and 28 age‐ and education‐matched nonsmokers [14 females, 14 males; age, 26.9 (2.4) years]. Subjects underwent imaging on two separate occasions 1 week apart: smoking satiety versus overnight smoking deprivation, in a randomized counterbalanced order. Our results show no difference in amygdala responses to faces between nonsmokers and satiated smokers. However, overnight deprivation from smoking was associated with a significantly lowered amygdala response to fear, an effect that was probabilistically mapped to the basolateral amygdala. We suggest that aberrant amygdala reactivity in overnight‐deprived smokers may reflect a pre‐existing vulnerability to smoking and/or increase the risk of smoking relapse after a cessation attempt. Hum Brain Mapp, 2011. © 2011 Wiley‐Liss, Inc.
Acid/base‐catalyzed cyclization of O‐alkynylphenylphosphonic acid monoesters and (O‐hydroxyphenyl)ethynylphosphinates
Authors: Peng Ai‐Yun , Du Yidan , Wei Yingling , Xie Liang , Ding Yi‐Xiang 
Published: May 2011

AbstractIn this work, we found that acids (i.e., HCl and NaHSO3) rather than bases could catalyze the cyclization of o‐alkynylphenylphosphonic acid monoesters at slow rates and give phosphaisocoumarins in low to medium yields, whereas the cyclization of (o‐hydroxyphenyl)ethynylphosphinates proceeded very smoothly under basic conditions rather than acidic conditions, and a series of phosphachromones could be prepared in excellent yields at room temperature using K2CO3 as catalyst. This is the first example of the synthesis of phosphorus heterocycles via acid/base‐catalyzed intramolecular cyclization of alkynes. Possible mechanisms were discussed. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:649–652, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20728