bluuebunny/crossref_metadata_2025 huggingface dataset:
Verstärken von Stahlbetonstützen mit textilbewehrtem Beton
Authors: Ortlepp Regine , Curbach Manfred
Published: September 2009

Der Aufsatz beschreibt die Ergebnisse experimenteller Untersuchungen zur Wirkung einer Textilbetonverstärkung an 2 m langen Stützen mit und ohne innen liegender Stahlbewehrung. Die Verstärkung mit textilbewehrtem Beton wurde auf zwei verschiedene Weisen ausgeführt, sowohl als vollständige Umwicklung über die gesamte Länge der Stützen als auch als teilweise Verstärkung über eine Länge von 30 cm in den Lasteinleitungsbereichen. Die einzelnen Anteile am Tragverhalten der verstärkten Stützen wurden untersucht. Ein einfaches Berechnungsmodell wird angegeben.

Strengthening of Columns using Textile Reinforced Concrete (TRC)

In the context of rehabilitation and repair works or in the course of usage changes of existing buildings the planning engineer frequently is confronted with the task of strengthening the loadbearing structure. This can become necessary, for example, if live loads are increased because of changes of use or if the structural safety of a building must be restored after a fire or earthquake. Particularly columns represent important components and elements of the static system for many buildings, whose main task is bearing normal forces.

The results of experimental tests on the effect of a strengthening from textile reinforced concrete at 2 m long columns, both with and without internal steel reinforcement, are described in this article. The strengthening with textile reinforced concrete was made both wrapping round completely along the full height of the columns and partly wrapping round the columns along 300 mm in the load introduction ranges. Related to the unstrengthened reference columns ultimate load increasings by up to 85% could thereby be achieved. The individual components of the load bearing properties are analysed. A simple calculation model is indicated.
Structures of Micelle‐Bound Selected Insect Neuropeptides and Analogues: Implications for Receptor Selection
Authors: Zdobinsky Tino , Scherkenbeck Jürgen , Zerbe Oliver , Antonicek Horst , Chen Heru
Published: September 2009

Neuropeptides control essential physiological processes in insects such as water balance and muscle activity. Due to their metabolic instability and adverse physiochemical properties, insect neuropeptides are unsuited for a direct application in plant protection. As a first approximation towards the biologically active conformation, the structures of selected neuropeptides from economically important pest insects were determined by NMR spectroscopy and fluorescence measurements in a membrane‐mimicking environment. A receptor binding model is suggested for the helicokinins and discussed in connection with biological activities and membrane‐bound conformations of linear and cyclic analogues.
“Doubly Selective” Antimicrobial Polymers: How Do They Differentiate between Bacteria?
Authors: Lienkamp Karen , Kumar Kushi‐Nidhi , Som Abhigyan , Nüsslein Klaus , Tew Gregory N.
Published: September 2009

We have investigated how doubly selective synthetic mimics of antimicrobial peptides (SMAMPs), which can differentiate not only between bacteria and mammalian cells, but also between Gram‐negative and Gram‐positive bacteria, make the latter distinction. By dye‐leakage experiments on model vesicles and complementary experiments on bacteria, we were able to relate the Gram selectivity to structural differences of these bacteria types. We showed that the double membrane of E. coli rather than the difference in lipid composition between E. coli and S. aureus was responsible for Gram selectivity. The molecular‐weight‐dependent antimicrobial activity of the SMAMPs was shown to be a sieving effect: while the 3000 g mol−1 SMAMP was able to penetrate the peptidoglycan layer of the Gram‐positive S. aureus bacteria, the 50000 g mol−1 SMAMP got stuck and consequently did not have antimicrobial activity.
Catalytic Carbanion Reactions: Formation and Reaction of Carbanions from Ester or Amide Equivalents Using Catalytic Amounts of Bases
Authors: Kobayashi Shu , Matsubara Ryosuke
Published: September 2009

We describe here carbanion reactions using catalytic amounts of bases. The carbanions formed are different from conventional carbanions in which stoichiometric amounts of bases are needed for the formation. Two types of reactions using such carbanions from amide (imido) and ester equivalents are discussed.
Cyclopentadienyl Ruthenium(II) Complexes with Bridging Alkynylphosphine Ligands: Synthesis and Electrochemical Studies
Authors: Di Credico Barbara , Fabrizi de Biani Fabrizia , Gonsalvi Luca , Guerri Annalisa , Ienco Andrea , Laschi Franco , Peruzzini Maurizio , Reginato Gianna , Rossin Andrea , Zanello Piero
Published: September 2009

The reaction of [CpRuCl(PPh3)2] (Cp=cyclopentadienyl) and [CpRuCl(dppe)] (dppe=Ph2PCH2CH2PPh2) with bis‐ and tris‐phosphine ligands 1,4‐(Ph2PC≡C)2C6H4 (1) and 1,3,5‐(Ph2PC≡C)3C6H3 (2), prepared by Ni‐catalysed cross‐coupling reactions between terminal alkynes and diphenylchlorophosphine, has been investigated. Using metal‐directed self‐assembly methodologies, two linear bimetallic complexes, [{CpRuCl(PPh3)}2(μ‐dppab)] (3) and [{CpRu(dppe)}2(μ‐dppab)](PF6)2 (4), and the mononuclear complex [CpRuCl(PPh3)(η1‐dppab)] (6), which contains a “dangling arm” ligand, were prepared (dppab=1,4‐bis[(diphenylphosphino)ethynyl]benzene). Moreover, by using the triphosphine 1,3,5‐tris[(diphenylphosphino)ethynyl]benzene (tppab), the trimetallic [{CpRuCl(PPh3)}3(μ3‐tppab)] (5) species was synthesised, which is the first example of a chiral‐at‐ruthenium complex containing three different stereogenic centres. Besides these open‐chain complexes, the neutral cyclic species [{CpRuCl(μ‐dppab)}2] (7) was also obtained under different experimental conditions. The coordination chemistry of such systems towards supramolecular assemblies was tested by reaction of the bimetallic precursor 3 with additional equivalents of ligand 2. Two rigid macrocycles based on cis coordination of dppab to [CpRu(PPh3)] were obtained, that is, the dinuclear complex [{CpRu(PPh3)(μ‐dppab)}2](PF6)2 (8) and the tetranuclear square [{CpRu(PPh3)(μ‐dppab)}4](PF6)4 (9). The solid‐state structures of 7 and 8 have been determined by X‐ray diffraction analysis and show a different arrangement of the two parallel dppab ligands. All compounds were characterised by various methods including ESIMS, electrochemistry and by X‐band ESR spectroscopy in the case of the electrogenerated paramagnetic species.
A Stereodivergent Synthesis of All Stereoisomers of Centrolobine: Control of Selectivity by a Protecting‐Group Manipulation
Authors: Schmidt Bernd , Hölter Frank
Published: September 2009

All stereoisomers of the natural product centrolobine are selectively synthesized, by starting from a common precursor. Key steps are an enantioselective allylation with enantiomerically pure allylsilanes, a tandem ring‐closing metathesis–isomerization reaction, and a Heck reaction by using an arene diazonium salt. By choosing appropriate conditions for the final deprotection step, either the cis‐configured centrolobines or their epimers are selectively obtained.
ChemInform Abstract: Superparamagnetism and Other Magnetic Features in Granular Materials: A Review on Ideal and Real Systems
Authors: Knobel M. , Nunes W. C. , Socolovsky L. M. , De Biasi E. , Vargas J. M. , Denardin J. C.
Published: October 2009

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Density Functional Theory Study of Hydrogen Bonds of Bipyridine with 1,3,5‐Benzenetricarboxylic Acid
Authors: Li Quan , Zhao Keqing
Published: September 2009

The hydrogen‐bonded dimer and trimer formed between 1,3,5‐benzenetricarboxylic acid and bipyridine have been investigated using a density functional theory (DFT) method and 6‐31++G** basis set. The interaction energies are −45.783 and −89.998 kJ·mol−1 for the most stable dimer and trimer, respectively, after the basis set superposition error and zero‐point corrections. The formation of O–H...N hydrogen bonds makes O–H symmetric stretching modes in the dimer and trimer red‐shifted relative to those of the 1,3,5‐benzenetricarboxylic acid monomer. The natural bond orbit analysis shows that the inter‐molecular charge transfers are 0.60475e and 1.20225e for the dimer and trimer, respectively. Thermodynamic analysis indicates that the formation of trimer is an exothermic and spontaneous process at low and room temperature. A supramolecule can be constructed through the strong N···H–O intermolecular hydrogen bonds between bipyridine and 1,3,5‐benzenetricarboxylic acid, which is in good agreement with the experimental results.
Theoretical Studies on Electronic Structures and NMR Spectra of Oligo(4‐vinylpyridine)
Authors: Zhao Hongjian , Zhou Jia , Hu Lingjing , Teng Qiwen
Published: September 2009

Poly(4‐vinylpyridine) was determined to possess conductivity in the experiment. In order to understand properties of the polymer, a series of 4‐vinylpyridine oligomers were designed. The structures of these oligomers were optimized using density function theory (DFT) at B3LYP/6‐31G(d) level. The energy gaps and thermal stabilities of the oligomers were decreased when the chain lengths were increased. These properties were also decreased owing to the protonation of the pyridine ring. The holes were easily injected into the oligomers in the presence of hydrochloride. The electrons were conducted in the side chain composed of the pyridine rings rather than the main chain owing to the saturation of the main chain. The 13C nuclear magnetic resonance (NMR) spectra and nucleus independent chemical shifts (NICS) of these compounds were calculated at B3LYP/6‐31G(d) level. The chemical shifts of the carbon atoms connected with the nitrogen atoms in the protonated pyridines were moved upfield in comparison with those of the pyridines. The addition of hydrochloride on the pyridine ring in the oligomers led to the increase of the aromaticities, namely the aromaticities of the oligomers were obviously improved when the pyridine rings were protonated.
Microwave‐assisted Synthesis of Pyrazolo[4,3‐f]quinolin‐7‐one Derivatives via Multi‐component Reactions
Authors: Peng Juhua , Hao Wenjuan , Wang Xiang , Tu Shujiang , Ma Ning , Zhang Ge
Published: September 2009

A series of new pyrazolo[4,3‐f]quinolin‐7‐one derivatives were synthesized by multi‐component reactions of equimolar amount of aromatic aldehydes with 2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione and 1H‐indazol‐5‐amine in ethylene glycol without catalyst under microwave irradiation. This one‐pot protocol has the advantage of good yields, simple workup procedure and shorter reaction time.
New Preparation Methodology of Functionalized Picolines
Authors: Nie Lifei , Yong Jianping , Ba Hang , Aisa Haji Akber
Published: September 2009

Under the organomagnesium complex n‐Bu2CH3MgLi conditions, picoline compounds provide a new entry to a broad range of polyfunctional picoline derivatives, after reaction with various electrophiles.
γ‐Irradiation Degradation of Methamidophos
Authors: Zhao Renbang , Bao Huaying , Xia Lingyun
Published: September 2009

The irradiation degradation of methamidophos in aqueous solutions by 60Co‐γ rays was investigated. The effects of absorbed doses, saturated gas, and the additive of H2O2 on the degradation were also studied. The results showed that the oxidative radical, such as ·OH, played an important role in the irradiation degradation of methamidophos; while the reductive radicals, e−aq and ·H, had no contribution to the degradation. The degradation rate of methamidophos increased with the increase of the irradiation dosage. At certain irradiation dosage, methamidophos could be degraded completely. The degradation rate of methamidophos in the solution saturated with oxygen was higher than those saturated with other gases, which reached 100% when the absorbed dose was 8 kGy. H2O2 degraded methamidophos slowly when it was used alone, but could accelerate the degradation obviously when it was used with irradiation together.
Binding Interaction of Captopril with Metal Ions: A Fluorescence Quenching Study
Authors: Siddiqi K. S. , Bano Shaista , Mohd Ayaz , Khan Aslam Aftab Parwaz
Published: September 2009

The binding interaction of captopril (CPL) with biologically active metal ions Mg2+, Ca2+, Mn2+, Co2+, Ni2+, Cu2+and Zn2+was investigated in an aqueous acidic medium by fluorescence spectroscopy. The experimental results showed that the metal ions quenched the intrinsic fluorescence of CPL by forming CPL‐metal complexes. It was found that static quenching was the main reason for the fluorescence quenching. The quenching constant in the case of Cu2+was highest among all quenchers, perhaps due to its high nuclear charge and small size. Quenching of CPL by metal ions follows the order Cu2+>Ni2+>Co2+>Ca2+>Zn2+>Mn2+>Mg2+. The quenching constantKsv, bimolecular quenching constantKq, binding constantKand the binding sites "n" were determined together with their thermodynamic parameters at 27 and 37°C. The positive entropy change indicated the gain in configurational entropy as a result of chelation. The process of interaction was spontaneous and mainly ΔS‐driven.
Removal of Naphthol Green B from Aqueous Solution by Calcined Layered Double Hydroxides: Adsorption Property and Mechanism Studies
Authors: Zhang Feng , Ni Zheming , Xia Shengjie , Liu Xiaoming , Wang Qiaoqiao
Published: September 2009

The adsorption of naphthol green B (NGB) by Mg/Al‐LDO (layered double oxides) with a Mg/Al molar ratio of 3:1 was investigated in a batch mode. Our study indicates that the maximum capacity of NGB adsorption at equilibrium is 193.4 mg and the percentage of absorption is 96.7%, with an adsorbent dose of 1.0 g/L under the following condition: 200 mg/L NGB concentration, temperature 298 K, pH 10.0 and an equilibrium time of 80 min. Langmuir and Freundlich adsorption models were used for fitting the isotherms, and the thermodynamic parameters have been calculated, which showed that the adsorption process was spontaneous and exothermic in nature. In the light of so called "memory effect", the Mg/Al‐LDO was found to recover their original layered structure after adsorption, and part of NGB ions intercalated into the interlayer of LDH (layered double hydroxides), which has been supported by XRD and FTIR. In addition, the competitive anions for adsorption and the regeneration of Mg/Al‐LDO have also been investigated.
New Azobenzene Dye Colorimetric and Ratiometric Chemosensors for Mercury(II) Ion
Authors: Guo Min , Xue Wei , Guan Mingyun , Sun Jianhua , Yin Gui
Published: September 2009

A new series of azobenzene dyes, which possessed colorimetric and ratiometric recognition to Hg2+ based on the mechanism of internal charge transfer (ICT), was developed and characterized. The molecules involving azo and imino functional groups can coordinate with Hg2+ to result in a large blue shift from 453 to 363 nm corresponding to a notable color change from orange to pale yellow in aqueous methanol solution (H2O/CH3OH=1/4, V/V), which can be applied to naked eye detection of Hg2+. The sensitivity, selectivity and binding mode of the sensors to Hg2+ were investigated by UV‐Vis spectroscopy.
Complexes of Diquat with Dibenzo‐24‐Crown‐8
Authors: Li Shijun , Huang Feihe , Slebodnick Carla , Ashraf‐khorassani Mehdi , Gibson Harry W.
Published: September 2009

The complexation between dibenzo‐24‐crown‐8 (1) and diquat (2) was investigated in detail by NMR, MS and X‐ray analysis. It was found that dibenzo‐24‐crown‐8 and diquat formed a 1:1 complex 1·2 in acetone with Ka=2.0×102 L·mol−1, but, as shown by X‐ray analysis, a crystalline 2:1 host:guest inclusion complex 12·2 was isolated, in which a single molecule of diquat is enclosed in the concave cavity provided by two dibenzo‐24‐crown‐8 host molecules. Both results are different from the previously assumed stoichiometry of the complexation between dibenzo‐24‐crown‐8 and diquat. This result enriches the range of host‐guest complexes based on dibenzo‐24‐ crown‐8 and provides new opportunities for developing more complicated structures and chemosensors for diquat.
Efficient and Mild Protocol for the Synthesis of 4(3)‐Substituted 3(4)‐Nitro‐1H‐pyrroles and 3‐Substituted 4‐Methyl‐2‐tosyl‐1H‐pyrroles from Nitroolefins and Tosylmethyl Isocyanide in Ionic Liquids
Authors: Qin Jie , Zhang Ji , Wu Bo , Zheng Zhangguo , Yang Meng , Yu Xiaoqi
Published: September 2009

A mild and convenient method for the synthesis of 4(3)‐substituted 3(4)‐nitro‐1H‐pyrroles and 3‐substituted 4‐methyl‐2‐tosyl‐1H‐pyrroles from nitroolefins and tosylmethyl isocyanide (TosMIC) in ionic liquid 1‐butyl‐3‐methylimidazolium bromide ([bmIm]Br) was developed. The reactions were performed at room temperature with KOH as base with good yields in a short time (about 2 h). Some tough conditions, such as absolutely anhydrous organic solvents, low temperature, hazardous and expensive strong base or organic base, were not needed. The yields of 4(3)‐substituted 3(4)‐nitro‐1H‐pyrroles were moderate, but excellent yields were achieved for the preparation of 3‐substituted 4‐methyl‐2‐tosyl‐1H‐pyrroles. This strategy was quite general and it worked in a broad range of nitroolefins with aromatic, aliphatic or heterocyclic substituents. The recovered ionic liquid could be reused as solvent for several times without significant decrease of reaction yields.
Chisiamols A–F, Triterpenoids from Chisocheton siamensis
Authors: Xie Bojun , Yang Shengping , Zhang Chen , Yue Jianmin
Published: September 2009

Six new apotirucallane‐type triterpenoids, chisiamols A–F (1–6), along with two known compounds, were isolated from the twigs of Chisocheton siamensis. The structures of compounds 1–6 were established on the basis of spectroscopic and chemical methods.
DRIVE—Dispatching Requests Indirectly through Virtual Environment
Authors: Choi Hyung Won , Kwak Hukeun , Sohn Andrew , Chung Kyusik
Published: September 2009

Dispatching a large number of dynamically changing requests directly to a small number of servers exposes the disparity between the requests and the machines. In this paper, we present a novel approach that dispatches requests to servers through virtual machines, called Dispatching Requests Indirectly through Virtual Environment (DRIVE). Client requests are first dispatched to virtual machines that are subsequently dispatched to actual physical machines. This buffering of requests helps to reduce the complexity involved in dispatching a large number of requests to a small number of machines. To demonstrate the effectiveness of the DRIVE framework, we set up an experimental environment consisting of a PC cluster and four benchmark suites. With the experimental results, we demonstrate that the use of virtual machines indeed abstracts away the client requests and hence helps to improve the overall performance of a dynamically changing computing environment. Copyright © 2009 John Wiley & Sons, Ltd.
The velocity structure of the hypocenter area of 2003 M6.2 and M6.1 Dayao earthquake
Authors: Zhou Long‐Quan , Ma Hong‐Sheng , Jiang Chang‐Sheng , Zhou Jun‐Jie
Published: September 2009

We determine the 2003 M6.2 and M6.1 Dayao earthquake sequence location and velocity structure of the hypocenter area by the simultaneous inversion of hypocenter location and velocity structure. The distribution of the M6.2 earthquake sequences shows the shape of a ‘V’ along the depth, which corresponds to the reversing triangle shape of low‐velocity structure, namely, the after‐shocks of M6.2 are distributed along the transitional zones of high‐ and low‐velocity structure. The zones of rupture of M6.2 and M6.1 are located on the southeast side of the reversing triangle shape of low‐velocity structure. The mainshock of M6.2 ruptures downwards and the mainshock of M6.1 ruptures upwards along the transitional zones of high‐ and low‐velocity structure. The velocity structure at the depth of 6 km shows that there is the quadrant of high‐ and low‐velocity structure and the aftershocks of M6.2 and M6.1 are distributed along the northwest transitional zones of high‐ and low‐velocity structure. The value of low‐velocity structure at the southeast side of M6.2 is higher than the value of the low‐velocity structure at the northwest side, which is disadvantageous to rupture southeastward for M6.2 and is advantageous to accumulate the energy for the occurrence of M6.1. Copyright © 2009 John Wiley & Sons, Ltd.
DNA‐Based Polymers as Chiral Templates for Second‐Order Nonlinear Optical Materials
Authors: Wanapun Duangporn , Hall Victoria J. , Begue Nathan J. , Grote James G. , Simpson Garth J.
Published: September 2009

The unique symmetry properties of chiral systems allow the emergence of coherent second harmonic generation in polymeric materials lacking polar order. Deoxyribonucleic acid (DNA) treated with the surfactant cetyltrimethylammonium (CTMA) was drop‐cast to spontaneously form films that are active for coherent second harmonic generation (SHG). SHG images acquired as a function of incident and exigent polarization are in good agreement with theoretical predictions assuming nonpolar D∞ symmetry for the double‐stranded DNA chains. Doping the DNA films with crystal violet substantially increases the efficiency of SHG, but does not significantly alter the polarization‐dependence, suggesting that the SHG generated upon doping arises from the same chiral‐specific origin, presumably templated by the DNA. These results raise the possibility of new design strategies for organic nonlinear optical materials based on soft chiral polymers that do not require polar order.
Selectivity versus Mobility: Separation of Anode and Cathode in Microbial Bioelectrochemical Systems
Authors: Harnisch Falk , Schröder Uwe
Published: September 2009

During the operation of a microbial bioelectrochemical system, charge balance must be maintained between the anode and the cathode. In an ideal scenario, the charge balance would be realized by the unhindered migration of H+ or OH−. At the same time, any kind of diffusion (crossover) between both electrode compartments should be avoided. However, as several studies have demonstrated, the experimental reality does not match this ideal picture. Crossover processes occur and H+/OH− migration only plays an inferior role in the charge‐balancing ion transfer, which results in significant losses in the performance of the microbial bioelectrochemical system. This Minireview summarizes the conflict of selectivity versus mobility and discusses principle strategies to cope with the resulting constraints, including pH‐static operation and the use of different separator materials and membrane‐free systems. Finally, we show that every setup compromises either selectivity or mobility, and no apparent ideal solution currently exists.
Immunohistochemical expression of E‐cadherin in sclerosing adenosis, ductal carcinoma in situ and invasive ductal carcinoma of the breast
Authors: Facina Gil , Lopes‐Costa Pedro Vitor , Dos Santos Alesse Ribeiro , De Vasconcelos‐Valença Rodrigo Jose , Pinho‐Sobral André Luis , Ferreira‐Filho Celso Pires , Alencar Airlane Pereira , Gebrim Luiz Henrique , Da Silva Benedito Borges
Published: September 2009

E‐cadherin (EC) is an important glycoprotein cell‐adhesion molecule that appears to play a significant role in the progression of breast lesions. The objective of this study was to evaluate EC expression in sclerosing adenosis, ductal carcinoma in situ and invasive ductal carcinoma. Samples of breast lesions from 44 women were used in this study, comprising cases of sclerosing adenosis (n = 11), ductal carcinoma in situ (DCIS) (n = 10) and invasive ductal carcinoma (n = 23). Immunohistochemical evaluation of EC expression was assessed semiquantitatively and considered negative (<10% of cells with stained cytoplasmic membranes), positive+ (10–50% of cells stained) or positive++ (> 50% of cells stained). Fisher's exact test was used to compare the distribution of staining intensity in the lesions (P< 0.05). There was a progressive loss of EC expression from benign to malignant lesions. This difference was statistically significant when sclerosing adenosis was compared with DCIS (P < 0.0002), when sclerosing adenosis was compared with invasive ductal carcinoma (P < 0.008) and when DCIS was compared with invasive ductal carcinoma (P < 0.007). The present findings point to a significant association between reduced EC expression and the progression and aggressivity of breast lesions. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.
RanBPM regulates the progression of neuronal precursors through M‐phase at the surface of the neocortical ventricular zone
Authors: Chang YoonJeung , Paramasivam Murugan , Girgenti Matthew J. , Walikonis Randall S. , Bianchi Elisabetta , LoTurco Joseph J.
Published: September 2009

Many of the mitoses that produce pyramidal neurons in neocortex occur at the dorsolateral surface of the lateral ventricles in the embryo. RanBPM was found in a yeast two‐hybrid screen to potentially interact with citron kinase (CITK), a protein shown previously to localize to the surface of the lateral ventricles and to be essential to neurogenic mitoses. Similar to its localization in epithelia, RanBPM protein is concentrated at the adherens junctions in developing neocortex. The biochemical interaction between CITK and RanBPM was confirmed in coimmunoprecipitation and protein overlay experiments. To test for a functional role of RanPBM in vivo, we used in utero RNAi. RanBPM RNAi decreased the polarization of CITK to the ventricular surface, increased the number of cells in mitosis, and decreased the number of cells in cytokinesis. Finally, the effect of RanBPM knockdown on mitosis was reversed in embryos mutant for CITK. Together, these results indicate that RanBPM, potentially through interaction with CITK, plays a role in the progression of neocortical precursors through M‐phase at the ventricular surface. © 2009 Wiley Periodicals, Inc. Develop Neurobiol, 2010
A novel H1N1 virus causes the first pandemic of the 21st century
Authors: Peiris J. S. Malik , Tu Wen‐wei , Yen Hui‐ling
Published: September 2009

A novel H1N1 virus of swine origin (H1N1v ) is currently spreading in humans, giving rise to the first pandemic in 40 years. The disease is of moderate severity but has notable differences from seasonal influenza. In contrast to seasonal influenza, those over 60 years are relatively spared, a likely consequence of the presence of H1N1v cross‐neutralizing antibody in this age group. Most patients appear to have mild influenza‐like illness and many of the complications leading to hospitalization and mortality occur in those with underlying disease conditions or pregnancy. Studies in animal models suggest that the novel H1N1v pandemic virus causes a more severe illness and appears to have a greater predilection for the alveolar epithelium than seasonal influenza viruses. As there are as yet little data on the pathogenesis and immunology of H1N1v infection in humans, we have reviewed relevant data from past pandemics, from seasonal influenza and avian influenza H5N1 to highlight key issues pertaining to pathogenesis and immunology.
Chains and Nanochannels Self‐Assembled from Carbido Clusters, Silver Ions and Heterocyclic Ligands – Crystal Structures of the 1D Coordination Polymers [{AgOC4H8{Rh6C(CO)15}AgOC4H8}pyz]∞ and [bipy{Ag2Ru6C(CO)16}(bipy)2{Ag2Ru6C(CO)16}·2C4H8O]∞
Authors: Della Pergola Roberto , Sironi Annalisa , Manassero Carlo , Manassero Mario
Published: September 2009

Two prototypical carbido anionic clusters, the prismatic [Rh6C(CO)15]2– and the octahedral [Ru6C(CO)16]2–, can add two electrophilic Ag–NCMe+ fragments, which were exploited to condense the clusters with bifunctional heterocyclic ligands, such as pyrazine (pyz) or 4,4′‐bipyridine (bipy), forming 1D chains of formula [{Ag(OC4H8){Rh6C(CO)15}Ag(OC4H8)}pyz]∞ and [bipy{Ag2Ru6C(CO)16}(bipy)2{Ag2Ru6C(CO)16}·2C4H8O]∞, both characterized by single‐crystal X‐ray diffraction. In the former, the two Ag+ ions are on opposite sides, and the chains are tightly packed. In the latter, the two silver ions are directly bound, and the metal clusters are connected alternatively by one and two linkers, giving rise to large channels.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Versatile Synthesis of Various Substituted Taurines from Vicinal Amino Alcohols and Aziridines
Authors: Chen Ning , Jia Weiyi , Xu Jiaxi
Published: October 2009

Taurine and structurally diverse substituted taurines have been synthesized by peroxyformic acid oxidation of the thiazolidine‐2‐thione intermediates generated from vicinal amino alcohols or aziridines and carbon disulfide. Thestereochemistry and mechanisms of the reactions are disscussed. The method is a salt‐free and versatile route, convenient in terms of purification, and can be used to synthesize optically active substituted taurines. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Diversity‐Oriented Synthesis of Chlorinated Arenes by One‐Pot Cyclizations of 4‐Chloro‐1,3‐bis(trimethylsilyloxy)buta‐1,3‐dienes
Authors: Wolf Verena , Adeel Muhammad , Reim Stefanie , Villinger Alexander , Fischer Christine , Langer Peter
Published: September 2009

A variety of 3‐chlorosalicylates were prepared by one‐potcyclizations of the first reported 4‐chloro‐1,3‐bis(trimethylsilyloxy)buta‐1,3‐dienes with various 1,3‐dielectrophiles. These include cyclizations with 3‐silyloxy‐2‐en‐1‐ones, 3‐aryl‐3‐silyloxy‐2‐en‐1‐ones, 1‐methoxy‐1‐en‐3‐ones, 1,1‐bis(methylthio)‐1‐en‐3‐ones, 3‐oxo orthoesters, 1,1,3,3‐tetraethoxypropanes, 1,1‐diacetylcyclopropane, and 3‐formylchromones. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Sensitively Electrochemical Sensing for Sequence‐Specific Detection of Phosphinothricin Acetyltransferase Gene: Layer‐by‐Layer Films of Poly‐L‐Lysine and Au‐Carbon Nanotube Hybrid
Authors: Du Meng , Yang Tao , Zhang Yongchun , Jiao Kui
Published: September 2009

An electrochemical DNA sensing film was constructed based on the multilayers comprising of poly‐L‐lysine (pLys) and Au‐carbon nanotube (Au‐CNT) hybrid. A precursor film of mercaptopropionic acid (MPA) was firstly self‐assembled on the Au electrode surface. pLys and Au‐CNT hybrid layer‐by‐layer assembly films were fabricated by alternately immersing the MPA‐modified electrode into the pLys solution and Au‐CNT hybrid solution. Cyclic voltammetry was used to monitor the consecutive growth of the multilayer films by utilizing [Fe(CN)6]3−/4− and [Co(phen)3]3+/2+ as the redox indicators. The outer layer of the multilayer film was the positively charged pLys, on which the DNA probe was easily linked due to the strong electrostatic affinity. The hybridization detection of DNA was accomplished by using methylene blue (MB) as the indicator, which possesses different affinities to dsDNA and ssDNA. Differential pulse voltammetry was employed to record the signal response of MB and determine the amount of the target DNA sequence. The established biosensor has high sensitivity, a relatively wide linear range from 1.0×10−10 mol/L to 1.0×10−6 mol/L and the ability to discriminate the fully complementary target DNA from single or double base‐mismatched DNA. The sequence‐specific DNA related to phosphinothricin acetyltransferase gene from the transgenically modified plants was successfully detected.
Bioelectrochemical Characterization of Horseradish and Soybean Peroxidases
Authors: Frasconi Marco , Favero Gabriele , Tortolini Cristina , Mazzei Franco
Published: September 2009

Heme peroxidase are ubiquitous enzymes catalyzing the oxidation of a broad range of substrates by hydrogen peroxide. In this paper the bioelectrochemical characterization of horseradish peroxidase (HRP) and soybean peroxidase (SBP), belonging to class III of the plant peroxidase superfamily, was studied. The homogeneous reactions between peroxidases and some common redox mediators in the presence of hydrogen peroxide have been carried out by cyclic voltammetry. The electrochemical characterization of the reactions involving enzyme, substrate and mediators concentrations allowed us to calculate the kinetic parameters for the substrate–enzyme reaction (KMS) and for the redox mediator–enzyme reaction (KMM). A full characterization of the direct electron transfer kinetic parameters between the electrode and enzyme active site was also performed by opportunely modeling data obtained from cyclic voltammetry and square wave voltammetry experiments. The experimental data obtained with immobilized peroxidases show enhanced direct electron transfer and excellent electrocatalytical performance for H2O2. Despite the structural similarities and common catalytic cycle, HRP and SBP exhibit differences in their substrate affinity and catalytic efficiency. Basing on our results, it can be concluded that peroxidase from soybean represents an interesting alternative to the classical and largely employed one obtained from horseradish as biorecognition element of electrochemical mediated biosensors.
Novel Solid‐Contact Ion‐Selective Microelectrodes for Localized Potentiometric Measurements
Authors: Lamaka Svetlana V. , Taryba Maryna G. , Zheludkevich Mikhail L. , Ferreira Mario G. S.
Published: September 2009

The design and properties of novel type of solid‐contact ionophore‐based ion‐selective microelectrodes are reported. The microelectrode is based on an insulated needle‐shaped metallic wire with an exposed apex. The ion‐to‐electron transducer is made of poly(3‐octylthiophene‐2,5‐diyl) and placed between an ion‐selective membrane and the metallic tip. The ion‐selective polyvinyl chloride‐based membrane is deposited atop the layer of conductive polymer. The length of the ion‐sensitive part of the electrode is less than 10 μm. pH and Mg2+‐selective microelectrodes were constructed and tested showing stable potential and fast response that are essential properties for the practical application of microelectrodes for localized scanning measurements.
Detection of Explosives Using Field‐Effect Transistors
Authors: Sharon Etery , Freeman Ronit , Willner Itamar
Published: September 2009

The gate surfaces of ion‐sensitive field‐effect transistor (ISFET) devices were functionalized with the π‐donor units, 6‐hydroxydopamine (1) or 4‐aminothiophenol (2). Concentration of trinitrotoluene, TNT, on the gate via π‐donor‐acceptor interactions yields charge‐transfer complexes that alter the gate potential. This enables the label‐free analysis of TNT with a detection limit corresponding to 1×10−7 M.
Electrochemical Sensing of NADH and Glutamate Based on Meldola Blue in 1,2‐Diaminobenzene and 3,4‐Ethylenedioxythiophene Polymer Films
Authors: Doaga Rodica , McCormac Timothy , Dempsey Eithne
Published: September 2009

The redox mediator Meldola blue (MB) was entrapped into two polymers, poly‐1,2‐diaminobenzene (p‐DAB) and poly‐3,4‐ethylenedioxythiophene (p‐EDOT) by potential cycling and films were applied to NADH oxidation with subsequent glutamate detection using immobilized glutamate dehydrogenase. Both polymer films were tested for electrocatalysis of NADH using amperometry at Eapp=0.1 V vs. Ag/AgCl and similar response characteristics were obtained with sensitivity values of 6.1 nA μM−1, linear range up to 0.5 mM (R2=0.9972) and LOD of 50 μM. Subsequent amperometric determination of glutamate resulted in sensitivity 0.7 nA μM−1, linearity 0–100 μM and detection limit of 2 μM glutamate.
Preparation and Characterization of Mixed‐Valent Osmium Hexacyanoferrate/Silicomolybdate Hybrid Films and Their Electrocatalytic Properties
Authors: Tung Chun‐Fang , Balamurugan A. , Chen Shen‐Ming
Published: September 2009

A polynuclear mixed‐valent osmium hexacyanoferrate/silicomolybdate film electrode has been prepared using repetitive cyclic voltammetry. The cyclic voltammograms have been recorded for the deposition of a mixed‐valent osmium hexacyanoferrate/silicomolybdate hybrid film directly from the mixture of Os3+, Fe(CN6)3−, and SiMo12O404− ions from the acidic aqueous solutions. The polynuclear mixed‐valent osmium hexacyanoferrate/silicomolybdate film exhibited four redox couples. The electrocatalytic properties of the osmium hexacyanoferrate/silicomolybdate film electrode have been studied. The modified electrode has shown good electrocatalytic properties towards the oxidation of dopamine, ascorbic acid, epinephrine, norepinephrine, and reduction of IO3−, Fe3+.
Modified Carbon Paste Electrode for Kinetic Investigation and Simultaneous Determination of Ascorbic and Uric Acids
Authors: Rodrigues Lima Phabyanno , Barbosa de Miranda Paulo Rogério , Bof de Oliveira Adriano , Oliveira Fonseca Goulart Marília , Tatsuo Kubota Lauro
Published: September 2009

The present work explores, for the first time, the electrocatalytic oxidation of ascorbic acid (AscH2) and its determination in the presence of uric acid (UA) on the in situ activated 4‐nitrophthalonitrile modified carbon paste electrode. The kinetic constant κ for the catalytic reaction for the electrocatalytic oxidation of ascorbic acid, evaluated by cyclic voltammetry, chronoamperometry and RDE voltammetry provided values around 106 L mol−1 s−1. The sensor provided a linear response range for AscH2 and UA from 5.0 up to 120.0 μmol L−1 with detection limits of 1.6 μmol L−1and 1.3 μmol L−1, respectively. The sensor was applied for the simultaneous determination of AscH2 and UA in urine samples and the average recoveries for these samples were 99.8 (±3.1)% and 99.9 (±2.1)%, respectively .
Selective and Sensitive Voltammetric Determination of Dopamine in Blood by Electrochemically Treated Pencil Graphite Electrodes
Authors: Özcan Ali , Şahin Yücel
Published: September 2009

Preparation of electrochemically treated pencil graphite (ETPG) electrode and its application for the determination of DA in the presence of ascorbic (AA) and uric (UA) acids were investigated. Several important parameters were worked to control the performance of the ETPG electrode which showed a high selectivity and sensitivity toward DA. A linear relationship was obtained for dopamine (DA) over the concentration range of 0.01 and 5.0 μM with a detection limit of 0.31 nM in the presence of AA and UA. The fabrication reproducibility of the ETPG electrodes (n=10) showed an acceptable reproducibility with a RSD of 2.0% for 5.0 μM DA. The determination of DA in blood serum without any pretreatment and dilution has been reported for the first time in this work.
Electrocatalytic Nitrite Reduction to Nitrogen Oxide by a Synthetic Analogue of the Active Site of Cu‐Containing Nitrite Reductase Incorporated in Nafion Film
Authors: Migita Yusaku , Yokoyama Hiroshi , Minami Akiko , Mori Takanori , Nojiri Masaki , Suzuki Shinnichiro , Yamaguchi Kazuya
Published: September 2009

The electrocatalytic reduction of nitrite to NO by [CuMe2bpa(H2O)(ClO4)]+ (1), which is a model for the active site of copper‐containing nitrite reductase, incorporated in Nafion film was investigated. The Cu complex in the Nafion matrix exhibits an intense band at 267 nm and a broad band around 680 nm, assigned to d–d and ligand field transitions, respectively. The 77‐K EPR spectrum of 1 in the Nafion matrix reveals the typical axial signals (g//=2.28, g$\rm{_\perp}$=2.08, A//=13.3 mT) of a tetragonal Cu2+ chromophore. The redox potential, which is related to the Cu+/Cu2+ couple, was −146 mV (ΔE=72 mV) at pH 5.5. The redox reaction of 1 in Nafion was not dependent on pH and was a diffusion‐controlled process. The electronic structure and redox properties of 1 in the negatively charged polymer matrix were almost the same as those in aqueous solution. In the presence of nitrite, an increase in the cathodic current was observed in the cyclic voltammogram of 1 in the Nafion matrix. The current increase was dependent on the nitrite concentration and pH in solution. Upon reaching −400 mV, a linear generation of NO was observed for the 1/Nafion film coated electrode. The relationship between the rate of NO generation and the nitrite concentration in solution was analyzed with the Michaelis–Menten equation, where Vmax=45.1 nM s−1 and Km=15.8 mM at pH 5.5. The Cu complex serves the function of both the catalyst and electron transport in the Nafion matrix. The sensitivity of the electrode was estimated to be 3.23 μA mM−1 in the range of 0.1–0.4 mM nitrite.
Cytogenetic genotoxicity of amoxicillin
Authors: İstifli Erman Salih , Topaktaş Mehmet
Published: September 2009

Amoxicillin (AMO), a drug used in the treatment of infections caused by susceptible bacteria, has been evaluated for its ability to induce genotoxicity in human peripheral blood lymphocytes. The potential genotoxic effects of AMO were investigated in vitro by the sister chromatid exchange (SCE), chromosomal aberration (CA), and micronucleus (MN) tests. The cells were treated with 400, 600, 800, and 1,000 μg/ml AMO in the presence and absence of a metabolic activator (S9 mix), respectively. In this study, AMO did not induce SCEs or CAs in human peripheral blood lymphocytes both in the presence and absence of the metabolic activator. AMO concentration‐dependently decreased the proliferation index (PI) in the absence of the metabolic activation for 24‐hr treatment period. Mitotic index (MI) was generally found to have been reduced when compared with the negative control but not with the solvent control in cultures treated with AMO for 24 hr. AMO did not decrease the PI and MI in the presence of the metabolic activator. Furthermore, AMO neither induced the formation of MN nor decreased the nuclear division index in human peripheral blood lymphocytes both in the presence and absence of the metabolic activator. According to the present results, we suggest that AMO does not pose genotoxic risk for patients who are under therapy against bacterial infections. Environ. Mol. Mutagen., 2010. © 2009 Wiley‐Liss, Inc.
Formaldehyde and leukemia: Epidemiology, potential mechanisms, and implications for risk assessment
Authors: Zhang Luoping , Freeman Laura E. Beane , Nakamura Jun , Hecht Stephen S. , Vandenberg John J. , Smith Martyn T. , Sonawane Babasaheb R.
Published: September 2009

Formaldehyde is widely used in the United States and other countries. Occupational and environmental exposures to formaldehyde may be associated with an increased risk of leukemia in exposed individuals. However, risk assessment of formaldehyde and leukemia has been challenging due to inconsistencies in human and animal studies and the lack of a known mechanism for leukemia induction. Here, we provide a summary of the symposium at the Environmental Mutagen Society Meeting in 2008, which focused on the epidemiology of formaldehyde and leukemia, potential mechanisms, and implication for risk assessment, with emphasis on future directions in multidisciplinary formaldehyde research. Updated results of two of the three largest industrial cohort studies of formaldehyde‐exposed workers have shown positive associations with leukemia, particularly myeloid leukemia, and a recent meta‐analysis of studies to date supports this association. Recent mechanistic studies have shown the formation of formaldehyde‐induced DNA adducts and characterized the essential DNA repair pathways that mitigate formaldehyde toxicity. The implications of the updated findings for the design of future studies to more effectively assess the risk of leukemia arising from formaldehyde exposure were discussed and specific recommendations were made. A toxicogenomic approach in experimental models and human exposure studies, together with the measurement of biomarkers of internal exposure, such as formaldehyde‐DNA and protein adducts, should prove fruitful. It was recognized that increased communication among scientists who perform epidemiology, toxicology, biology, and risk assessment could enhance the design of future studies, which could ultimately reduce uncertainty in the risk assessment of formaldehyde and leukemia. Environ. Mol. Mutagen., 2010. Published 2009 Wiley‐Liss, Inc.
The ‘humped’ soil production function: eroding Arnhem Land, Australia
Authors: Heimsath Arjun M. , Fink David , Hancock Greg R.
Published: September 2009

We report erosion rates and processes, determined from in situ‐produced beryllium‐10 (10Be) and aluminum‐26 (26Al), across a soil‐mantled landscape of Arnhem Land, northern Australia. Soil production rates peak under a soil thickness of about 35 cm and we observe no soil thicknesses between exposed bedrock and this thickness. These results thus quantify a well‐defined ‘humped’ soil‐production function, in contrast to functions reported for other landscapes. We compare this function to a previously reported exponential decline of soil production rates with increasing soil thickness across the passive margin exposed in the Bega Valley, south‐eastern Australia, and found remarkable similarities in rates. The critical difference in this work was that the Arnhem Land landscapes were either bedrock or mantled with soils greater than about 35 cm deep, with peak soil production rates of about 20 m/Ma under 35–40 cm of soil, thus supporting previous theory and modeling results for a humped soil production function. We also show how coupling point‐specific with catchment‐averaged erosion rate measurements lead to a better understanding of landscape denudation. Specifically, we report a nested sampling scheme where we quantify average erosion rates from the first‐order, upland catchments to the main, sixth‐order channel of Tin Camp Creek. The low (∼5 m/Ma) rates from the main channel sediments reflect contributions from the slowly eroding stony highlands, while the channels draining our study area reflect local soil production rates (∼10 m/Ma off the rocky ridge; ∼20 m/Ma from the soil mantled regions). Quantifying such rates and processes help determine spatial variations of soil thickness as well as helping to predict the sustainability of the Earth's soil resource under different erosional regimes. Copyright © 2009 John Wiley & Sons, Ltd.
Intermediate Temperature Anode‐Supported Fuel Cell Based on BaCe0.9Y0.1O3 Electrolyte with Novel Pr2NiO4 Cathode
Authors: Taillades G. , Dailly J. , Taillades‐Jacquin M. , Mauvy F. , Essouhmi A. , Marrony M. , Lalanne C. , Fourcade S. , Jones D. J. , Grenier J.‐C. , Rozière J.
Published: October 2009

A proton conducting ceramic fuel cell (PCFC) operating at intermediate temperature has been developed that incorporates electrolyte and electrode materials prepared by flash combustion (yttrium‐doped barium cerate) and auto‐ignition (praseodymium nickelate) methods. The fuel cell components were assembled using an anode‐support approach, with the anode and proton ceramic layers prepared by co‐pressing and co‐firing, and subsequent deposition of the cathode by screen‐printing onto the proton ceramic surface. When the fuel cell was fed with moist hydrogen and air, a high Open Circuit Voltage (OCV > 1.1 V) was observed at T > 550 °C, which was stable for 300 h (end of test), indicating excellent gas‐tightness of the proton ceramic layer. The power density of the fuel cell increased with temperature of operation, providing more than 130 mW cm–2 at 650 °C. Symmetric cells incorporating Ni‐BCY10 cermet and BCY10 electrolyte on the one hand, and Pr2NiO4 + δ and BCY10 electrolyte on the other hand, were also characterised and area specific resistances of 0.06 Ω cm2 for the anode material and 1–2 Ω cm2 for the cathode material were obtained at 600 °C.