bluuebunny/crossref_metadata_2025_split huggingface dataset:
The embryonic expression patterns and the knockdown phenotypes of zebrafish ADP‐ribosylation factor‐like 6 interacting protein gene
Authors: Huang Hsing‐Yen , Dai En‐Sheng , Liu Jeng‐Ting , Tu Chi‐Tung , Yang Tzu‐Ching , Tsai Huai‐Jen 
Published: December 2008

AbstractADP‐ribosylation factor‐like 6 (Arl6) mutation is linked to human disease and Arl6 interacts with Arl6 interacting protein (Arl6ip). However, the expression pattern and function of Arl6ip during embryogenesis are unknown. To confirm whether abnormal Arl6ip function might result in embryonic defects in zebrafish, we examined the expression patterns of arl6ip during embryogenesis, and they were maternally expressed and exhibited in the brain, optic primordia, hypochord, spinal cord, myotome, heart, fin‐bud, kidney, trunk, and retina. Knockdown of Arl6ip revealed the following phenotypic defects: microphthalmia, disorganized pigment pattern, flat head, defective tectum, deficient pectoral fins, abnormal pneumatic duct, pericardial edema, and deformed trunk. Particularly, histological dissection of the retinae of arl6ip‐morphants revealed that neuronal differentiation is severely delayed, resulting in no formation of retinal layers. We further confirmed that opsins of arl6ip‐morphants were not transcribed. Based on this evidence, Arl6ip may play important roles in zebrafish ocular, heart, and fin‐bud development. Developmental Dynamics 238:232–240, 2009. © 2008 Wiley‐Liss, Inc.
Osterix‐mCherry transgenic medaka for in vivo imaging of bone formation
Authors: Renn Joerg , Winkler Christoph 
Published: December 2008

AbstractIntramembranous and chondral bone formation by osteoblasts is found in all vertebrates. The genetic network controlling osteoblast differentiation is highly conserved and regulated by a small number of key factors, including the zinc‐finger transcription factor Osterix. Expression analysis of osterix in the teleost model medaka revealed a highly restricted expression in skeletal regions. For in vivo imaging, we generated transgenic medaka expressing mCherry under control of the osterix promoter. We show that the transgene becomes expressed in early osteoblasts, which have not yet mineralized bone matrix, and remains high in matured and mineralizing osteoblasts. Life imaging of transgenic larvae provided insight into the appearance and behavior of early osteoblasts during development of the teleost cranium, vertebrae, and caudal fin. In summary, osterix‐mCherry transgenic medaka enable us to analyze osteoblasts during different maturation phases in vivo and represent a unique tool to study osteoblast behavior in vertebrate embryos and adults. Developmental Dynamics 238:241–248, 2009. © 2008 Wiley‐Liss, Inc.
Requirement for a core 1 galactosyltransferase in the Drosophila nervous system
Authors: Lin Yuh‐Ru , Reddy B.V.V.G. , Irvine Kenneth D. 
Published: December 2008

AbstractA Drosophila embryo triply stained to reveal neurons, hemocytes, and O‐glycosylation. The O‐glycosylation is required for nervous system morphogenesis. See Lin et al., Developmental Dynamics 237:3703‐3714. Developmental Dynamics, 2009. © 2008 Wiley‐Liss, Inc.
A Carbazole‐Containing Difunctional RuII Complex That Functions as a pH‐Induced Emission Switch and an Efficient Sensitizer for Solar Cells
Authors: Fan Su‐Hua , Wang Ke‐Zhi , Yang Wei‐Chun 
Published: December 2008

AbstractA heteroleptic ruthenium(II) complex of [Ru(Hecip)(Hdcbpy) (NCS)2]–·[N(C4H9)4]+ (where Hecip = 2‐(9‐ethyl‐9H‐carbazol‐3‐yl)‐1H‐imidazo[4,5‐f][1,10]phenanthroline and Hdcbpy = monodeprotonated 2,2′‐bipyridyl‐4,4′‐dicarboxylic acid) has been synthesized and characterized by elementary analysis, cyclic voltammetry, MALDI‐TOF mass spectrometry, and 1H NMR, IR, UV/Vis absorption, and emission spectroscopy. The ground‐ and excited‐state acid–base properties of the complex have been studied by means of UV/Vis absorption spectrophotometric and spectrofluorimetric titrations in a Britton–Robinson/DMF (v/v, 4:1) buffer solution. The complex was found to act as pH‐induced off‐on‐off/on‐off‐on‐off‐type emission switch, when excited at 530/470 nm, with a protonation/deprotonation reaction taking place near the physiological pH range. The performance of the complex‐sensitized TiO2 nanocrystalline solar cell with 0.05 M I2 and 0.5 M LiI in 50 % acetonitrile and 50 % propylene carbonate (PC) as the electrolyte solution and a platinum film as the counter electrode has also been studied, and was compared to that of the cis‐[Ru(H2dcbpy)2(NCS)2] (N3)‐sensitized solar cell under the same experimental conditions.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Construction and Photoluminescence of Monophase Hybrid Materials Derived from a Urea‐Based Bis‐Silylated Bipyridine
Authors: Li Huanrong , Lin Nana , Wang Yige , Feng Yu , Gan Quanying , Zhang Hongjie , Dong Qinglin , Chen Yuhuan 
Published: December 2008

AbstractA urea‐based bis‐silylated bipyridine ligand derived from 4,4′‐diamino‐2,2′‐bipyridine has been prepared. Organic–inorganic hybrid materials with a high loading of lanthanide 2,2‐bipyridine moieties were obtained by using the silylated bipyridine as the only siloxane network precursor in the presence of lanthanide ions (or lanthanide complexes). The in‐situ formation of lanthanide complexes from lanthanide ions and the silylated bipyridine during the sol–gel processing was confirmed by the luminescence behavior of the obtained hybrid materials and that of the corresponding pure lanthanide complex [Ln(bpy)2Cl3·2H2O]. Tris(2‐thenoyltrifluoroacetonato)europium(III) dihydrate complexes were coupled to the hybrid materials via adduct formation with the nitrogen atoms from bis‐silylated bipyridine, and the coordinated water molecules were expelled from the first coordination sphere of the lanthanide(III) ion as revealed by the much longer lifetime of the hybrid material compared with that of the pure tris(2‐thenoyltrifluoroacetonato)europium(III). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Oligonucleotide Duplexes with Tethered Photoreactive Ruthenium(II) Complexes: Influence of the Ligands and Their Linker on the Photoinduced Electron Transfer and Crosslinking Processes of the Two Strands
Authors: Deroo Stéphanie , Le Gac Stéphane , Ghosh Sumana , Villien Mathilde , Gerbaux Pascal , Defrancq Eric , Moucheron Cécile , Dumy Pascal , Kirsch‐De Mesmaeker Andrée 
Published: December 2008

AbstractThe photoreactivity of new RuII‐oligonucleotide conjugates is investigated in the presence of their complementary strands. The goal is to determine the origins of different effects of parameters that control the photocrosslinking process of the two strands. Therefore, two RuII compounds, either [Ru(tap)3]2+or [Ru(tap)2phen]2+ (tap = 1,4,5,8‐tetraazaphenanthrene, phen = 1,10‐phenanthroline) with different oxidation powers, were tethered with different linkers to either the 5′‐ or 3′‐phosphate end of the probe strand before hybridization with the complementary strand. These systems were studied by time‐resolved emission spectroscopy, UV/Vis absorption experiments, PAGE and MS (ESI) analyses. The best yields of photocrosslinking (45 %) obtained with [Ru(tap)3]2+ tethered to the 3′‐position are due to (i) a higher oxidation power of the complex and (ii) its attachment at the 3′‐position. Indeed, this tethering favours the interaction of the Ru compound with the duplex and, therefore, inhibits its photodechelation. This work allows better design of sequence‐specific DNA photodamaging agents prior to biological applications.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Reactions of 2,2‐Diphenyl‐1‐picrylhydrazyl (DPPH) with Two Syringylic Phenols or One Aroxide Derivative
Authors: Hristea Elena N. , Covaci‐Cîmpeanu Irina C. , Ioniţaǎ Gabriela , Ioniţaǎ Petre , Draghici Constantin , Caǎproiu Miron T. , Hillebrand Mihaela , Constantinescu Titus , Balaban Alexandru T. 
Published: December 2008

AbstractThe reactions between excess 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and either 4‐hydroxy‐3,5‐dimethoxybenzaldehyde (syringaldehyde, 1) or methyl 4‐hydroxy‐3,5‐dimethoxybenzoate (methyl syringate, 2) afford different products from those obtained with the corresponding aroxide (3) of 1. In the former case (with the free phenols) the aryloxy (syringyl) group substitutes the 4‐nitro group of DPPH, yielding dinitro products 7 and 8 (new stable free radicals) and 9 and 10 (corresponding hydrazines), whereas in the latter case (with the sodium aroxide 3) the aryloxy (syringyl) group substitutes one of the phenyl groups of DPPH in the para position, forming trinitro products 14 (new stable free radical) and 15 (corresponding hydrazine). Accompanying products were isolated by TLC and identified by their 1H NMR, 13C NMR, UV/Vis, and EPR spectra. The reaction mechanisms involving hydrazyl and aroxyl free radicals are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Is the Elimination of Lithium Alkoxide Easier from a Vinyllithium or from an Alkyllithium? A DFT Study of the Aromatization of 3‐Vinylidene‐2,3‐dihydrobenzofurans to Benzofurans
Authors: Fressigné Catherine , Girard Anne‐Lise , Durandetti Muriel , Maddaluno Jacques 
Published: December 2008

AbstractA possible mechanism for the last step of a cascade transformation in which lithiated propargyl ether 2 is converted into 3‐vinylbenzofuran 7 is described. Starting from the lithiated E olefin 3A, our DFT computations show that the final departure of lithium alkoxide is not easy unless an excess of nBuLi, the importance of which has been noted experimentally, prompts a second deprotonation. This theoretical evidence was further supported by a complementary experiment involving dihydrobenzofuran 10. The deprotonation of this latter compound by nBuLi elicits a spontaneous syn elimination, probably through monolithiated intermediates 10Li and 6, regioisomers of 3A. The activation barriers calculated for these various transformations indicate that the elimination of lithium methoxide from β‐lithiated acetals requires around 10 times more energy when the precursor is a vinyllithium rather than an alkyllithium. A route passing through a sigmatropic rearrangement was also considered. This triggers the elimination of a molecule of methanol, which acts as a shuttle to transfer a proton from the heterocycle to the vinyl position. However, with the set of reaction coordinates considered, this mechanism passes through high‐lying activation barriers unless the conformation of the exocyclic double bond in 3 is Z (isomer 3B).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
An Efficient Molybdenum(VI)‐Catalyzed Direct Substitution of Allylic Alcohols with Nitrogen, Oxygen, and Carbon Nucleophiles
Authors: Yang Hongwei , Fang Ling , Zhang Ming , Zhu Chengjian 
Published: December 2008

AbstractDirect nucleophilic substitution of allylic alcohols with various nitrogen, oxygen, and carbon nucleophiles catalyzed by MoO2(acac)2 was realized. The corresponding products were obtained in moderate‐to‐excellent yields. Studies of the reaction mechanism showed that a carbenium intermediate was formed in the transition state. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of Symmetric Dinitro‐Functionalised Tröger's Base Analogues
Authors: Bhuiyan M. Delower H. , Mahon Andrew B. , Jensen Paul , Clegg Jack K. , Try Andrew C. 
Published: December 2008

AbstractThe synthesis of six new examples of 2,8‐dinitro‐substituted Tröger's base analogues are reported, together with the first examples of 1,7‐, 3,9‐ and 4,10‐dinitro Tröger's base analogues and the first example of a tetranitro Tröger's base compound. Several of these dinitro compounds lack substituents at the 2‐ and 8‐positions and therefore provide further examples of Tröger's base analogues derived from anilines lacking a para substituent. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of Substituted 5‐(Pyrrolidin‐2‐yl)tetrazoles and Their Application in the Asymmetric Biginelli Reaction
Authors: Wu Yong‐Yong , Chai Zhuo , Liu Xin‐Yuan , Zhao Gang , Wang Shao‐Wu 
Published: December 2008

AbstractA series of chiral substituted 5‐(pyrrolidin‐2‐yl)tetrazoles have been synthesized and evaluated as organocatalysts for the asymmetric Biginelli reaction. The relationship between catalytic activity and the different catalyst structures is briefly discussed. By using the optimized catalyst C10 (10 mol‐%), a series of 3,4‐dihydropyrimidin‐2(1H)‐one (DHPM) derivatives have been obtained in 63–88 % yields and 68–81 % ee values within 24 h at room temperature. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Metalated Nitriles: Internal 1,3‐Asymmetric Induction
Authors: Fleming Fraser F. , Liu Wang 
Published: December 2008

AbstractStereoselective alkylations of acyclic, metalated nitriles are intimately controlled by a remote stereocenter. Probing the optimal steric demand through alkylations with a series of substituted pentanenitriles reveal the fundamental requirements for 1,3‐asymmetric induction. Relaying these requirements into a predictive model suggests that the stereoselectivity arises from a preferential electrophilic attack on the more stable diamond lattice conformation of the metalated nitrile. Using this strategy a series of metalated alkanenitriles selectively intercept a diverse range of electrophiles in alkylations that efficiently install new quaternary centers. The metalated nitrile alkylations provide fundamental insight for remote stereoinduction and a solid foundation for further advances in stereoselective alkylations of flexible nucleophiles having a defined shape.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Multicomponent Access to Functionalized Mesoionic Structures Based on TFAA Activation of Isocyanides: Novel Domino Reactions
Authors: Arévalo María José , Kielland Nicola , Masdeu Carme , Miguel Miriam , Isambert Nicolas , Lavilla Rodolfo 
Published: December 2008

AbstractThe reactions of azines (isoquinolines, pyridine) with TFAA and isocyanides in a new domino process yield mesoionic acid fluorides with an imidazo[1,2‐a]azine core. This multicomponent reaction has a general character, tolerating a wide range of substitution patterns on each component, and displays an unprecedented arrangement of reaction pathways. The protocol allows the incorporation of a fourth synthetic input by the reaction of a suitable nucleophile (alcohols, thiols, amines) with the acid fluoride moiety.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
The Dependence of the Sensitivity and Reliability of Contactless Conductivity Detection on the Wall Thickness of Electrophoretic Fused‐Silica Capillaries
Authors: Tůma Petr , Samcová Eva , Štulík Karel 
Published: December 2008

AbstractA contactless conductivity detector (C4D) performance has been tested on a simple capillary electrophoretic separation in a standard fused‐silica capillary with an external diameter of 360 μm and in a thin‐walled capillary (an external diameter of 150 μm); the internal diameters of the two capillaries were identical, equal to 75 μm. Potassium and sodium ions have been separated in a morpholinoethanesulfonic acid/histidine background electrolyte (MES/His), over a wide range of its concentrations (0–100 mM). At low MES/His concentrations, the C4D response, obtained from the height of the potassium peak, is by 100 to 200 per cent higher for the thin‐walled capillary and the calibration dependences are linear, in contrast to the thick‐walled capillary. These differences between the two capillaries decrease with increasing MES/His concentration, the C4D response in the thin‐walled capillary is then higher by mere 20 per cent and the calibration dependences are linear in both the capillaries. The highest sensitivities have been obtained at a MES/His concentration of 50 mM, with LOD values for potassium ion of 2.0 and 2.6 μM, in the thin‐ and thick‐walled capillaries, respectively. The signal‐to‐noise ratios and the plate counts are generally similar for the two capillaries. It follows from the results that special thin‐walled capillaries can be advantageous when background electrolytes with very low conductivities must be employed.
Effects of Reduced Glutathione, Surface Active Agents, and Ionic Strength on the Detection of Metallothioneins by Using of Brdicka Reaction
Authors: Krizkova Sona , Fabrik Ivo , Adam Vojtech , Kukacka Jiri , Prusa Richard , Trnkova Libuse , Strnadel Jan , Horak Vratislav , Kizek Rene 
Published: December 2008

AbstractWe investigated the effects of two surface active agents (sodium dodecyl sulfate, SDS, and polyoxyethylene sorbitol, Tween‐20), ionic strength and reduced glutathione (GSH) on MT signals measured by adsorptive transfer stripping differential pulse voltammetry Brdicka reaction. If we compared the GSH and MT signals at the accumulation time of 120 s, the MT signal was more than two hundred times higher than the GSH one. The influence of Tween‐20 was investigated in a broad concentration range (from 10−8 to 10−11 %, v/v). We found that the catalytic Cat2 signal decreased for more than 60% with increasing Tween‐20 content. In the case of using SDS (10−3–10−6 M), the increase of Cat2 peak in the presence of the highest SDS concentration was determined. The height of Cat2 peak enhanced with increasing ionic strength mimicking by NaCl concentration. Based on the enhancement of the Cat2 peak we determined the ionic strength of fibroblasts sample and recalculated the concentration of MT determined there.
A Highly Selective Amperometric Hydrogen Peroxide Sensor Based on Silicomolybdate‐Doped‐Glutaraldehyde‐Cross‐Linked Poly‐L‐Lysine Film Modified Glassy Carbon Electrode
Authors: Wu Yu‐Ching , Thangamuthu R. , Chen Shen‐Ming 
Published: December 2008

AbstractSilicomolybdate‐doped‐glutaraldehyde‐cross‐linked poly‐L‐lysine (PLL‐GA‐SiMo) film modified glassy carbon electrode was prepared by means of electrostatically trapping the silicomolybdate anion in the cationic film. The PLL‐GA‐SiMo film was stable and the charge transport through the film was fast. The modified electrode shows excellent electrocatalytic activity towards hydrogen peroxide reduction with significant reduction of overpotential, however, not responded to potential interferrents such as dopamine, ascorbic acid and uric acid. This unique feature of PLL‐GA‐SiMo modified electrode allowed for the development of a highly selective method for the determination of H2O2 in the presence of interferents.
Electrochemical Synthesis of Polypyrrole in the Presence of Congo Red; Application to Selective Voltammetric Determination of Dopamine in the Presence of Ascorbic Acid
Authors: Shahrokhian Saeed , Zare‐Mehrjardi Hamid Reza 
Published: December 2008

AbstractThe electrosynthesis of polypyrrole (PPy) film has been achieved on glassy carbon electrode (GCE) in aqueous medium of Congo red (CR) by means of cyclic voltammetry (CV). The modified electrode exhibits high electrocatalytic activity toward dopamine (DA) oxidation, with drastic enhancement of the reversibility and peak currents. This modified electrode, due to electrostatic interactions, is capable to mask the response of ascorbic acid (AA) completely and provide an effective method for the detection of minor amounts of dopamine in the presence of high concentrations of AA. The electrochemical response of the film modified electrode is strongly dependent to the switching potential applied in the CV procedure of the electro‐polymerization. The results show that by increasing the switching potential more than 0.75 V, the peak of AA is gradually disappeared. This peak in potential of 0.85 V is reached to capacitive background current. With respect to the destruction of the conjugated structure of ppy and lowering the conductivity of the film at the surface of modified electrode, higher switching potentials cannot be suitable for electropolymerization procedure. The effects of various experimental parameters such as, number of polymerization cycles, switching potential, pH and potential sweep rate on the voltammetric response of dopamine were also investigated. The modified electrode shows a linear response to DA in the range of 0.5 to 100 μM with a detection limit of 0.1 μM. The prepared modified electrode does not show any considerable response toward sulfhydryl compounds, such as, cysteine, penicillamine and glutathione, revealing a good selectivity for voltammetric response to DA. The effective electrocatalytic property, ability for masking the voltammetric responses of the other biological reducing agents together with high reproducibility and stability make the modified electrode suitable for selective and sensitive voltammetric detection of sub‐micromolar amounts of DA in clinical and pharmaceutical preparations.
Selective Detection of Ascorbic Acid Using Octacyanomolybdate‐Doped‐Glutaraldehyde‐Cross‐Linked Poly‐L‐Lysine Film Modified Glassy Carbon Electrode
Authors: Thangamuthu R. , Wu Yu‐Ching , Chen Shen‐Ming 
Published: December 2008

AbstractThe present work describes oxidation of ascorbic acid (AA) at octacyanomolybdate‐doped‐glutaraldehyde‐cross‐linked poly‐L‐lysine (PLL‐GA‐Mo(CN)$\rm{ {_{8}^{4-}}}$ film modified glassy carbon electrode in 0.1 M H2SO4. The modified electrode has been successfully prepared by means of electrostatically trapping Mo(CN)$\rm{ {_{8}^{4-}}}$ mediator in the cationic film of glutaraldehyde‐cross‐linked poly‐L‐lysine. The dependence of peak current of modified electrode in pure supporting indicates that the charge transfer in the film was a mixed process at low scan rates (5 to 200 mV s−1), and kinetically restrained at higher scan rates (200 to 1000 mV s−1). Cyclic voltammetry and rotating disk electrode (RDE) techniques are used to investigate the electrocatalytic oxidation of ascorbic acid and compared with its oxidation at bare and undoped PLL‐GA film coated electrodes. The rate constant of catalytic reaction k obtained from RDE analysis was found to be 9.5×105 cm3 mol−1 s−1. The analytical determination of ascorbic acid has been carried out using RDE technique over the physiological interest of ascorbic acid concentrations with a sensitivity of 75 μA mM−1. Amperometric estimation of AA in stirred solution shows a sensitivity of 15 μA mM−1 over the linear concentration range between 50 and 1200 μM. Interestingly, PLL‐GA‐Mo(CN)$\rm{ {_{8}^{4-}}}$ modified electrode facilitated the oxidation of ascorbic acid but not responded to other electroactive biomolecules such as dopamine, uric acid, NADH, glucose. This unique feature of PLL‐GA‐Mo(CN)$\rm{ {_{8}^{4-}}}$ modified electrode allowed for the development of a highly selective method for the determination of ascorbic acid in the presence of interferents.
Recent progress in analytical capillary ITP
Authors: Gebauer Petr , Malá Zdena , Boček Petr 
Published: December 2008

AbstractITP is an electrophoretic technique that has been attracting constant attention for many years due to its pronounced capability to concentrate trace analytes by several orders of magnitude. In practice, it is used predominantly in capillary format, where the capillaries used have id ranging between 0.02 and 0.8 mm. The volumes of the samples introduced may be up to several tens of microliters and trace analytes diluted in such a volume are concentrated into zones having volumes in the range of picoliters. Moreover, it offers simultaneously efficient separation of the analytes. That is why ITP retains its important position in many current multistage and multidimensional separation schemes where it is used always as the starting step that brings preseparation and concentration of sample components. This article links up previous reviews on the topic and summarizes the progress of analytical capillary ITP since 2006; 90 reviewed papers include theory and methodological novelties as well as analytical applications. Papers using ITP as part of multistage separation schemes are also included.