bluuebunny/crossref_metadata_2025_split huggingface dataset:
First‐Principles Investigation of Anisotropic Electron and Hole Mobility in Heterocyclic Oligomer Crystals
Authors: Huang Jin‐Dou , Wen Shu‐Hao 
Published: May 2013

AbstractBased on quantum chemistry calculations combined with the Marcus–Hush electron transfer theory, we investigated the charge‐transport properties of oligothiophenes (nTs) and oligopyrroles (nPs) (n=6, 7, 8) as potential p‐ or n‐type organic semiconductor materials. The results of our calculations indicate that 1) the nPs show intrinsic hole mobilities as high as or even higher than those of nTs, and 2) the vertical ionization potentials (VIPs) of the nPs are about 0.6–0.7 eV smaller than the corresponding VIPs of the nTs. Based on their charge‐transport ability and hole‐injection efficiency, the nPs have potential as p‐type organic semiconducting materials. Furthermore, it was also found that the maximum values of the electron‐transfer mobility for the nTs are larger by one‐to‐two orders of magnitude than the corresponding maximum values of hole‐transfer mobility, which suggests that the nTs have the potential to be developed as promising n‐type organic semiconducting materials owing to their electron mobility.
Active Skeletal Ni Catalysts Prepared from an Amorphous Ni‐Zr Alloy in the Pre‐Crystallization State
Authors: Nozaki Ai , Kamegawa Takashi , Ohmichi Tetsutaro , Yamashita Hiromi 
Published: May 2013

AbstractSkeletal Ni catalysts were prepared from an amorphous Ni40Zr60 alloy (a‐NiZr) by heating at various temperatures under vacuum, followed by the selective extraction of Zr moieties by an HF treatment. Each sample was characterized by various spectroscopic methods, and the catalytic performance was tested in the hydrogenation of 1‐octene. The differences in preparation temperatures of a‐NiZr strongly affected the catalytic performance of the obtained catalysts, whereby those prepared from heated a‐NiZr in the pre‐crystallization state exhibited higher catalytic activity. Especially, moderate thermal treatment of a‐NiZr at a temperature slightly lower than that for its crystallization, that is, ∼573 K, resulted in a significant enhancement of the catalytic activity. Such prepared skeletal Ni catalyst can also be used efficiently for hydrogen generation from aqueous hydrazine.
pH‐ and Voltage‐Switchable Superhydrophobic Surfaces by Electro‐Copolymerization of EDOT Derivatives Containing Carboxylic Acids and Long Alkyl Chains
Authors: Darmanin Thierry , Guittard Frederic 
Published: May 2013

AbstractIn order to produce pH‐ and voltage‐switchable superhydrophobic surfaces, PEDOT derivatives containing various proportions of a EDOT monomer containing carboxylic groups (EDOTCOOH) and EDOT monomer‐containing dodecyl chains (EDOTOH12) are elaborated. The surface morphology and roughness depend highly on the proportion of the monomers. Superhydrophobic properties are reached for a mol % of EDOTCOOH between 0 and 25 %. It is possible to switch from superhydrophobic to hydrophilic (θwater until about 45°) by electrochemical reduction at low voltage (−1 V vs SCE) to remove the doping anions, following by treatment with NaOH to change the carboxylic groups into carboxylate. By elaborating smooth surfaces of each polymer, the effect of each treatment is reported. The reversibility of the reactions is also reported.
Atomic Layer Deposition of High Performance Ultrathin TiO2 Blocking Layers for Dye‐Sensitized Solar Cells
Authors: Kim Do Han , Woodroof Mariah , Lee Kyoungmi , Parsons Gregory N. 
Published: May 2013

AbstractDye‐sensitized solar cells (DSSCs) often use a thin insulating or semiconducting layer (typically TiO2) between the transparent conductive oxide and the mesoporous TiO2 to block electron/hole recombination at the conducting oxide/electrolyte interface. The blocking layer (BL) is essential to maintain efficient charge generation under low light conditions, at which DSSCs perform well compared to common semiconductor‐based photovoltaic devices. In this work, we show that atomic layer deposition (ALD) can produce ultrathin (<10 nm) BLs that significantly impede charge recombination in functional DSSCs, leading to improved photocurrents, open‐circuit photovoltages, and fill factors; this results in an increase in the overall efficiency from ≈7 % to ≈8.4 % under AM 1.5 G illumination. The 5–10 nm ALD BLs are the thinnest optimized DSSC BLs reported to date. The BL retards the open‐circuit voltage decay and extends the electron lifetime from ≈0.2 s to more than 10 s at 0.3 V, confirming that the ALD films significantly impede photogenerated charge recombination. By preparing BLs through other deposition techniques, we directly demonstrate that ALD results in better performance, even with thinner films, which is ascribed to the lower pinhole density of ALD materials.
A single transmission selection scheme for downlink distributed antenna system in multicell environment
Authors: Liu Yuxi , Liu Ju , Guo Weidong , Zheng Lina , Chen Peng 
Published: May 2013

SUMMARYIn this paper, based on maximum signal‐to‐interference‐plus‐noise ratio criterion at the receiver, we propose a single transmission selection scheme for distributed antenna system and investigate the corresponding ergodic capacity together with outage probability in multicell environment. Assuming that the channels suffer from independent non‐identical Nakagami‐m fading with integer values of fading severity parameter m, we derive exact closed‐form expressions for the ergodic capacity and outage probability. Monte‐Carlo simulations are carried out to validate the theoretical analysis. Simulation results show that the ergodic capacity and outage probability of the proposed single transmission selection scheme outperform that of blanket transmission scheme. Copyright © 2013 John Wiley & Sons, Ltd.
The Effect of C‐2 Substituents of Salicylaldehyde‐Based Thiosemicarbazones on the Synthesis, Spectroscopy, Structures, and Fluorescence of Nickel(II) Complexes
Authors: Lobana Tarlok S. , Kumari Poonam , Castineiras Alfonso , Butcher Ray J. 
Published: May 2013

AbstractThe aim of this investigation was to study the bonding patterns, geometry, and fluorescence properties of nickel(II) complexes with salicylaldehyde‐based thiosemicarbazones [(2‐OH‐5‐R1‐C6H3)C(R2)=NNHC(=S)NHR3, LH2] by invoking the effect of substituents at the C‐2 and N‐1 atoms of the thio ligands and by using bipyridines/phenanthrolines as auxiliary ligands. The methodology used for the preparation of complexes involved initial binding of NiII with a thio ligand in an organic solvent to yield an insoluble solid of empirical composition [NiL], which was reacted further with a N,N‐donor ligand. In this way, we have prepared a series of dinuclear complexes and two mononuclear complexes with stoichiometries [Ni2L2(bipy)(D)] [bipy = 2,2′‐bipyridine, L = L1 (R1, R2, R3 = H), D = H2O 1; L = L2 (R1, R2 = H, R3 = Me), D = CH3OH 2; L =L3 (R1, R2 = H, R3 = Et), D = CH3OH 4; L = L3, D = H2O 5; L = L4 (R1 = Me, R2 = H, R3 = Me), D = CH3OH 6], [Ni2L32(bipy)] (3), [Ni2L32(dmbipy)(H2O)] (7, dmbipy = 4,4′‐dimethyl‐2,2′‐bipyridine), [Ni2L52(bipy)2] (8, R1 = NO2, R2 = H, R3 = Me), [NiL6(bipy)] (9, R1 = NO2, R2 = H, R3 = Et), [NiL7(bipy)(H2O)] (10, R1 = H, R2 = Me, R3 = Et), [Ni2L32(4,4′‐bipy)] (11, 4,4′‐bipy = 4,4′‐bipyridine), and [Ni2L72(4,4′‐bipy)] (12). The dinuclear complexes involve (i) O,N3,S chelation with bridging N2 atoms to form trigonal‐bipyramidal/square‐planar complexes with a five‐coordinate and a four‐coordinate Ni center (3, 5:4‐coordination) and octahedral/square‐planar complexes (1, 2, 4–7, 6:4‐coordination), (ii) O,N3,S chelation with S bridges to form octahedral/octahedral complexes (8, 6:6‐coordination), and (iii) O,N3,S chelation to form square‐planar/square‐planar complexes (11, 12, 4:4‐coordiantion). The mononuclear complexes involve O, N3,S chelation and have square‐pyramidal (9) and octahedral (10) geometries. Complexes 1–10 are paramagnetic with μeff value in the range 2.97–3.38 μB. Complexes 2 and 3 exhibit fluorescence emission.
Spectral and Electrochemical Properties of Lanthanide Thiocyanate Complexes Ionic as Liquid Components
Authors: Ohaion T. , Kalisky Y. , Ben‐Eliyahu Y. , Becker J. Y. , Bettelheim Armand 
Published: May 2013

AbstractNew lanthanide‐containing ionic liquids (ILs) based on thiocyanate complexes of the type [BMIM]x–3[Ln(NCS)x(H2O)8–x] (BMIM = 1‐butyl‐3‐methylimidazolium; x = 6,7,8) have been reported in recent studies. These complexes are highly efficient for dissolving lanthanide complexes within ILs. Until now, only partial characterization of their properties has been reported. The present work describes the characterization of this type of complexes in both their pure liquid phase and in solution with EuIII and SmIII as the lanthanide ions. The number of water molecules as ligands was determined by luminescence measurements in the UV/Vis region. The composition of the complexes in solution was found to be similar to those in the solid state. The electrochemical behavior of the EuIII/EuII redox couple for [BMIM]5[Eu(NCS)8] at a glassy carbon electrode has been investigated in acetonitrile and in the [BMIM][SCN] IL. This couple is electrochemically quasireversible with E1/2 = –0.23 V [vs. normal hydrogen electrode (NHE)]. The diffusion coefficients of the complexes in solution were determined by cyclic voltammetry and chronopotentiometry and were found to be D = 1.1 ± 0.1 × 10–5 and 2.5 ± 0.3 × 10–8 cm2/s in acetonitrile and [BMIM][SCN], respectively. The diffusion coefficients of the reduced species were found to be D = 8.2 ± 0.4 × 10–6 and 2.1 ± 0.4 × 10–8 cm2/s in the two solvents, respectively. The standard rate constants of the single electron reduction were determined by cyclic voltammetry and found to be k0 = 1.2 ± 0.1 × 10–3 and 5.4 ± 0.8 × 10–5 cm/s in the two solvents, respectively.
Reactivity of (Dicarboxamide)MII–OH (M = Cu, Ni) Complexes – Reaction with Acetonitrile to Yield MII–Cyanomethides
Authors: Tehranchi Jacqui , Donoghue Patrick J. , Cramer Christopher J. , Tolman William B. 
Published: May 2013

AbstractThe complexes (Bu4N)(LMeMII–OH) (LMe = 2,6‐dimethylphenyl‐substituted pyridine(dicarboxamide); M = Cu or Ni) react with CH3CN to yield (Bu4N)(LMeM–CH2CN) cyanomethide complexes, which were fully characterized, including by X‐ray crystallography. These conversions contrast with the usual reactions of metal hydroxide complexes with nitriles, which typically involve attack at the nitrile carbon atom and formation of amides or carboxylic acids. Kinetic studies (M = Cu) revealed a first‐order dependence on the complex and a kinetic isotope effect [k(CH3CN)/k(CD3CN)] of 4. Various mechanisms involving either intra‐ or intermolecular deprotonation steps are proposed. In addition, (Bu4N)(LMeCu–OH) was oxidized by ferrocenium hexafluorophospate (FcPF6) to a proposed CuIII complex LMeCuOH at low temperature, and comparisons of its stability and reactivity with dihydroanthracene were drawn to its previously described congener with isopropyl substituents on the phenyl rings of the supporting ligand. The cyanomethide complex (Bu4N)(LMeCu(CH2CN)) was also reversibly oxidized both electrochemically (E1/2 = –0.345 V vs. Fc/Fc+) and chemically (FcPF6, –25 °C). The product was formulated as LMeCuIII(CH2CN), a new CuIII–alkyl complex relevant to such species proposed during copper‐catalyzed organic reactions.
Efficient Consecutive Four‐Component Synthesis of 5‐Acylpyrid‐2‐ones Initiated by Copper‐Free Alkynylation
Authors: Nordmann Jan , Breuer Natascha , Müller Thomas J. J. 
Published: May 2013

AbstractA one‐pot, consecutive, four‐component synthesis of 5‐acylpyrid‐2‐ones initiated by Pd/cataCXium® ABn catalysis proceeds under mild reaction conditions and in good yields, with a broad scope of three points of diversity. This sequence is superior to the initially proposed Pd/Cu‐catalyzed version because all four components can be employed in close to stoichiometric amounts.
Tandem Iminium/Copper Catalysis: Highly Enantioselective Synthesis of α,β‐Disubstituted Aldehydes
Authors: Kim Ju‐Hye , Park Eun‐Jin , Lee Hwa‐Jung , Ho Xuan‐Huong , Yoon Hyo‐Sang , Kim Pilsoo , Yun Hoseop , Jang Hye‐Young 
Published: May 2013

AbstractWith the goal of synthesizing biologically and synthetically valuable products under environmentally benign and economic conditions, an asymmetric organocatalytic reaction was combined with a copper catalytic reaction. This iminium/copper catalysis allowed highly optically active α,β‐disubstituted aldehydes to be synthesized with good yields in one‐pot fashion. The β‐substitution took place through iminium‐catalyzed Michael addition of nitromethane or diethyl malonate to the α,β‐unsaturated aldehydes, followed by copper‐assisted addition of TEMPO (2,2,6,6‐tetramethylpiperidin‐1‐yloxyl) at the aldehyde α‐position. An iminium/copper‐catalyzed tandem addition product was converted into a 3,4,5‐trisubstituted piperidine for X‐ray crystallographic analysis.
Determination of the Natural Dissolved Concentration of Zirconium in Seawater by Adsorptive Stripping Voltammetry
Authors: Schneider Alexandre B. , Nascimento Paulo C. , Bohrer Denise , de Carvalho Leandro M. , Guarda Ananda , Dias Daiane , Koschinsky Andrea 
Published: May 2013

AbstractA voltammetric method was developed for zirconium determination as Zr(IV)‐cupferron‐oxalate‐diphenylguanidine complex based on adsorptive accumulation at the HMDE (Epeak=−0.95 V). The supporting electrolyte was a mixture of acetate/acetic acid (pH 4.6) and ammonium acetate (pH 5.7) solutions. Eads=−0.6 V (vs. Ag/AgCl), tads=400 s, 10 mV s−1 scan rate, and DP mode were the main parameters. The linear range was 0.033 to 3.3×10−9 mol L−1, and the LOD and LOQ (tads=400 s) were 0.77 and 1.6×10−11 mol L−1, respectively. The method was adequate for seawater samples, although not sufficiently sensitive for surface waters.
Norfloxacin drug induces reproductive toxicity and alters androgen receptor gene expression in testes and cloacal gland of male Japanese quail (Coturnix Japonica)
Authors: Singh Ram P. , Sastry Kochiganti V.H. , Dubey Pawan K. , Agrawal Radha , Singh Renu , Pandey Nitin Kumar , Mohan Jag 
Published: May 2013

Abstract

In an attempt to investigate the reproductive toxicity of norfloxacin in Japanese quail, male quail were given norfloxacin at 20 mg/kg body weight for 14 d. Then reproductive function and androgen receptor (AR) gene expression was examined in treated and control birds. The results of the present study indicate that fertility, cloacal gland area, sperm concentration, and serum testosterone were reduced significantly (p &lt; 0.05) on day 14 in the norfloxacin-treated birds. Upregulation (p &lt; 0.05) of AR mRNA was also seen in the testes on the 14th d of treatment. A trend toward downregulation of AR mRNA was seen in the cloacal gland of norfloxacin-treated birds. Histological observations revealed that norfloxacin induces cellular atrophy in testes and changes in glandular tissue in the cloacal gland. The results of the present study demonstrate that norfloxacin induces testicular toxicity in Japanese quail. Environ Toxicol Chem 2013;32:2134–2138. © 2013 SETAC
Endogenous parathyroid hormone–related protein compensates for the absence of parathyroid hormone in promoting bone accrual in vivo in a model of bone marrow ablation
Authors: Zhu Qi , Zhou Xichao , Zhu Min , Wang Qian , Goltzman David , Karaplis Andrew , Miao Dengshun 
Published: May 2013

ABSTRACT

To assess the effect of hypoparathyroidism on osteogenesis and bone turnover in vivo, bone marrow ablation (BMXs) were performed in tibias of 8-week-old wild-type and parathyroid hormone–null (PTH−/−) mice and newly formed bone tissue was analyzed from 5 days to 3 weeks after BMX. At 1 week after BMX, trabecular bone volume, osteoblast numbers, alkaline phosphatase-positive areas, type I collagen-positive areas, PTH receptor–positive areas, calcium sensing receptor–positive areas, and expression of bone formation–related genes were all decreased significantly in the diaphyseal regions of bones of PTH−/− mice compared to wild-type mice. In contrast, by 2 weeks after BMX, all parameters related to osteoblastic bone accrual were increased significantly in PTH−/− mice. At 5 days after BMX, active tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts had appeared in wild-type mice but were undetectable in PTH−/− mice, Both the ratio of mRNA levels of receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) and TRAP-positive osteoclast surface were still reduced in PTH−/− mice at 1 week but were increased by 2 weeks after BMX. The expression levels of parathyroid hormone–related protein (PTHrP) at both mRNA and protein levels were upregulated significantly at 1 week and more dramatically at 2 weeks after BMX in PTH−/− mice. To determine whether the increased newly formed bones in PTH−/− mice at 2 weeks after BMX resulted from the compensatory action of PTHrP, PTH−/−PTHrP+/− mice were generated and newly formed bone tissue was compared in these mice with PTH−/− and wild-type mice at 2 weeks after BMX. All parameters related to osteoblastic bone formation and osteoclastic bone resorption were reduced significantly in PTH−/−PTHrP+/− mice compared to PTH−/− mice. These results demonstrate that PTH deficiency itself impairs osteogenesis, osteoclastogenesis, and osteoclastic bone resorption, whereas subsequent upregulation of PTHrP in osteogenic cells compensates by increasing bone accrual. © 2013 American Society for Bone and Mineral Research
Polyploidy Is Genetic Hence May Cause Non‐Adaptive Radiations, Whereas Pseudopolyploidy Is Genomic Hence May Cause Adaptive Non‐Radiations
Authors: GORELICK ROOT , OLSON KRYSTLE 
Published: May 2013

ABSTRACTThere are two ways eukaryotes double number of chromosomes: (1) whole genome duplication (polyploidy), in which all nuclear DNA is replicated, and (2) karyotypic fission (pseudopolyploidy), in which all chromosomes are physically bifurcated. We contrast polyploidy with pseudopolyploidy, highlighting when it is crucial to look at genetic vs. genomic levels. We review history of pseudopolyploidy, including recent mechanisms by which chromosomal bifurcation may occur and outline methods for detecting such genomic changes. We then delve into the evolutionary implications, with particular focus on adaptive potential, of these two forms of doubling chromosome numbers. We address the common assertion that polyploidy induces adaptive radiations, which contains three fallacies. First, while polyploidy causes quantum speciation, evolutionary theory implies that these radiations should be non‐adaptive. Polyploidy causes reproductive isolation, minute effective population sizes, and increased mutation rates, which all imply a diminished role for selection. Second, due to lack of karyotyping in recent decades and lack of distinction between genomic and genetic effects, it is usually impossible to detect pseudopolyploids. Third, pseudopolyploids lack minority cytotype exclusion because they readily backcross with their progenitors, which thereby means no reproductive isolation for newly formed pseudopolyploids. Pseudopolyploidy will thereby not result in radiations until pseudopolyploid descendants undergo subsequent chromosome rearrangements or grow new centromeres. Pseudopolyploids may have a modest selective advantage over their progenitors due to diminished linkage disequilibrium. Thus, pseudopolyploidy may induce adaptive non‐radiations. We encourage a renaissance of karyotyping to distinguish between these two mechanisms and a renaissance in genomic perspectives in evolution. J. Exp. Zool. (Mol. Dev. Evol.) 320B:286–294, 2013. © 2013 Wiley Periodicals, Inc.
Correlation of late gadolinium enhancement MRI and quantitative T2 measurement in cardiac sarcoidosis
Authors: Yang Yuesong , Safka Katherine , Graham John J. , Roifman Idan , Zia Mohammad I. , Wright Graham A. , Balter Meyer , Dick Alexander J. , Connelly Kim A. 
Published: May 2013

PurposeTo investigate the potentially improved detection and quantification of cardiac involvement using novel late‐gadolinium‐enhancement (LGE) cardiac magnetic resonance imaging (MRI) and quantitative T2 measurement to achieve better myocardial tissue characterization in systemic sarcoidosis.Materials and MethodsTwenty‐eight patients with systemic sarcoidosis underwent a cardiac magnetic resonance imaging (CMR) study on a 1.5T system. Precontrast CMR included left ventricular (LV) and right ventricular (RV) function and quantitative T2 measurement. Postcontrast LGE‐MRI included inversion‐recovery fast‐gradient‐echo (IR‐FGRE) and multicontrast late‐enhancement imaging (MCLE).ResultsLV functional parameters were normal in all patients (LVEF = 61.2 ± 8.5%) including with cardiac involvement (LVEF = 59.4 ± 12.1%) and without (LVEF = 61.7 ± 7.5%) while the average RV function was comparatively decreased (RVEF = 48.0 ± 6.6%, P < 0.0001). 21.4% of patients had cardiac involvement showing patchy or multiple focal hyperenhancement patterns in LV free wall, papillary muscles (PM), or interventricular septum. In two cases with PM involvement, the PM abnormal LGE foci were only observed on MCLE. For precontrast T2 measurements, a significantly decreased T2 measurement was observed in regions demonstrating LGE, compared to the LGE‐negative group (focal LGE‐positive regions vs. negative: 40.0 ± 2.4 msec vs. 53.0 ± 2.6 msec, P < 0.0001).ConclusionLGE‐MRI can identify cardiac involvement in systemic sarcoidosis. MCLE might be more sensitive at detecting subtle myocardial lesion. The decreased T2 observed in cardiac sarcoid may reflect its inactive phase, thus might provide a noninvasive method for monitoring disease activity or therapy. J. Magn. Reson. Imaging 2014;39:609–616. © 2013 Wiley Periodicals, Inc.
Insights into the Ring‐Expansion Polymerization of Thiiranes with 2,4‐Thiazolidinedione
Authors: Schuetz Jan‐Hendrik , Sandbrink Lennart , Vana Philipp 
Published: May 2013

AbstractThe behavior of the ring‐expansion homopolymerization of 2 (phenoxymethyl)thiirane (PMT) and propylene sulfide (PS), respectively, with thiazolidine‐2,4‐dione (TZD) as a cyclic initiator is investigated. The polymerizations show steadily growing molar masses with increasing monomer conversions. In addition, reversible merging reactions between rings are observed, with up to six merged macrocycles formed. The degree of merging is strongly dependent on the initial monomer concentration, whereas temperature has only a small impact. Under optimized conditions, ring‐poly(PMT) polymer with values of Mn up to 50 250 g mol−1 and dispersities down to 1.11 can be synthesized. DSC and ESI‐MS measurements of the novel ring‐poly(PS) prove the formation of ring polymer having topological purity above 95%.magnified image