bluuebunny/crossref_metadata_2025_split huggingface dataset:
Remarkable Effect of 4‐Substituted 2,2′‐Bipyridine Ligands on the Stereochemistry of Ruthenium(II) Complexes
Authors: Grabulosa Arnald , Beley Marc , Gros Philippe C. 
Published: March 2008

Abstract[RuL3](PF6)2 complexes containing 4‐alkoxycarbonyl‐substituted unsymmetrical bipyridine ligands (L) have been obtained exclusively as the fac isomers by simple reaction of L with ruthenium(III) chloride in ethylene glycol under microwave irradiation. The position of the alkoxycarbonyl group on the pyridine ring and its transesterification by ethylene glycol were found critical for stereocontrol during ruthenium coordination. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The role of retinoids and their receptors in metabolic disorders
Authors: Meissburger Bettina , Wolfrum Christian 
Published: March 2008

AbstractRetinoid derivatives are potent regulators of a wide variety of cellular functions through the modulation of nuclear receptor activity. Three distinct families of retinoid receptors have been identified so far, namely retinoic acid receptors, retinoic acid X receptors, and retinoic acid‐related orphan receptors. This review focuses on retinoid signaling and the regulation of metabolic processes by the family of retinoic acid receptors in relation to the development of metabolic disorders.
Nitrogen‐Containing Tricyclic and Tetracyclic Compounds by Stereoselective Samarium Diiodide Promoted Cyclizations of Quinolyl‐Substituted Ketones – A New Access to Azasteroids
Authors: Aulenta Francesca , Wefelscheid Ulrike K. , Brüdgam Irene , Reißig Hans‐Ulrich 
Published: March 2008

AbstractIn this report, we describe our experiments dealing withsamarium diiodide promoted cyclizations of quinolyl‐substituted ketones 6–12 and also the attempted reductive cyclization of carbazole‐containing ketone 13. These precursors were prepared by Heck‐type coupling reactions of the corresponding hetaryl nonaflates with adequately substituted olefins as a key step. The cyclization of compounds 7–12 led to nitrogen‐containing tri‐ and tetracyclic compounds 23–28 in moderate to good yields and generally proceeded in a highly diastereoselective fashion. The azatetracycles present steroid‐like skeletons but with unnatural cis–cis annulation of rings B, C and D. We also describe the chemical modification of the styrene‐type double bond of these products, which provided highly functionalized steroid‐type compounds such as 29, 30 and 32.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Chiral Sterically Congested Phosphane‐Amide Bifunctional Organocatalysts in Asymmetric Aza‐Morita–Baylis–Hillman Reactions of N‐Sulfonated Imines with Methyl and Ethyl Vinyl Ketones
Authors: Guan Xiao‐Yang , Jiang Ying‐Qing , Shi Min 
Published: March 2008

AbstractA series of chiral sterically congested phosphane‐amide bifunctional Lewis bases L1–L3 have been successfully synthesized and their application in asymmetric aza‐Morita–Baylis–Hillman (aza‐MBH) reactions of N‐sulfonated imines with activated olefins such as methyl and ethyl vinyl ketone has been investigated under mild conditions. The corresponding aza‐MBH adducts can be obtained in good‐to‐excellent yields (up to 98 %) and moderate‐to‐good enantioselectivities (up to 91 or 93 % ee) in dichloromethane at room temperature (20 °C) with these novel chiral bifunctional phosphane Lewis bases.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Two Stage Colour Modulation of Triarylmethine Dyes Derived from a Photochromic Naphthopyran
Authors: Gabbutt Christopher D. , Heron B. Mark , Kolla Suresh B. , Mcgivern Matthew 
Published: March 2008

AbstractThe synthesis of the unsymmetrical triarylmethine dyes 4derived from a lithiated naphthopyran and diaryl ketones is reported. In toluene solution 4 display a typical reversible photochromic response becoming coloured upon irradiation with UV light and fading upon cessation of irradiation. At low pH an intensely coloured dye cation is generated and UV irradiation of this solution results in a further colour change as a consequence of photochromic cycling of the naphthopyran unit.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Direct Electrochemistry of Myoglobin on a Room Temperature Ionic Liquid Modified Electrode and Its Application to Nitric Oxide Biosensing
Authors: Zhang Qiang , Wei Wei , Zhao Guang‐Chao 
Published: March 2008

AbstractMyoglobin (Myb) was successfully immobilized on a room temperature ionic liquid (RTIL), 1‐ethyl‐3‐methyl imidazolium tetrafluoroborate ([EMIM][BF4]) modified basal plane graphite (BPG) electrode. The electrochemical behavior of Myb on RTIL modified BPG electrode was explored and the results from cyclic voltammetry (CV) showed a well‐defined and quasi‐reversible CV peaks with a formal potential of −0.379 V (versus Ag/AgCl) in a phosphate buffer solution (pH 7.0). RTIL shows an obvious promotion for the direct electron‐transfer between Myb and BPG electrode. Myb adsorbed on electrode surface exhibits an obvious electrocatalytic activity for the reduction of nitric oxide (NO). The catalytic current is corresponding linearly to the NO concentration in the range of 7.0×10−7 to 7.0×10−6 M with a limit of detection of 2.0×10−7 M (three times the ratio of signal to noise, S/N=3).
Mental models and transformative learning: The key to leadership development?
Authors: Johnson Homer H. 
Published: March 2008

AbstractWhat separates successful leaders from unsuccessful ones is their mental models or meaning structures, not their knowledge, information, training, or experience per se. Thus the development of leaders should focus on acquisition of new mental models, models that offer more valid and useful ways for effectively dealing with the complex challenges of leadership. This article describes a process, based on transformative learning, that seems to be the key to assisting leaders in acquiring more useful mental models and in turn becoming more effective leaders.
Detection and identification of optical activity using polarimetry – applications to biophotonics, biomedicine and biochemistry
Authors: Bahar Ezekiel 
Published: March 2008

AbstractPolarized light that is reflected or transmitted through chiral specimens can be used to detect and identify biological and chemical materials including human tissue. The determination of the silent footprints of the chiral properties of the biological materials on scattered polarized light is the basis for these investigations. It is of primary importance to identify which combinations of the elements of the Mueller matrix for reflected or for transmitted light can be used to determine the optical activity of the biochemical materials. The optical activity of chiral materials is characterized by optical rotation and circular dichroism. The explicit analytical dependence of these specific elements of the Mueller matrix, upon the angles of incidence and scatter, upon the wavelength and upon the type of chirality has the potential to provide experimentalists with guidance in determining the optimum use of optical polarimetric scatterometers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Integrin α5‐induced EGFR activation by prothrombin triggers hepatocyte apoptosis via the JNK signaling pathway
Authors: Wang Ziqiu , Wang Meifang , Carr Brian I. 
Published: March 2008

AbstractWe have previously shown that prothrombin, a blood coagulation factor, can cause an inhibition of DNA synthesis in normal rat hepatocytes. To explore the mechanisms of this prothrombin action, we examined its effects on the activation of fibronectin receptor integrin α5, since fibronectin was found to be degraded by prothrombin actions in primary hepatocyte cultures. We found that prothrombin treatment of rat hepatocytes without addition of any growth factor induced tyrosine phosphorylation of integrin α5 and interaction of integrin α5 with epidermal growth factor receptor (EGFR), leading to EGFR tyrosine phosphorylation at tyrosine residues Tyr‐845 and Tyr‐1173. EGFR tyrosine phosphorylation triggered phosphorylation of its down‐stream target Shc and the activation of the c‐Jun N‐terminal kinase (JNK) pathway. Prothrombin also induced hepatocyte apoptosis, a change in cell shape and activation of caspase 3 pathway. The JNK pathway is most likely involved in prothrombin‐induced hepatocyte apoptosis, because pre‐treatment of hepatocytes with JNK kinase inhibitor II (SP600125) antagonized these prothrombin actions. The data suggest that integrin‐related EGFR activation by prothrombin can induce cell growth inhibition and apoptosis via an EGFR‐JNK signaling pathway. J. Cell. Physiol. 216: 551–557, 2008. © 2008 Wiley‐Liss, Inc.
The geodiamolide H, derived from brazilian sponge Geodia corticostylifera, regulates actin cytoskeleton, migration and invasion of breast cancer cells cultured in three‐dimensional environment
Authors: Freitas Vanessa M. , Rangel Marisa , Bisson Letícia F. , Jaeger Ruy G. , Machado‐Santelli Gláucia M. 
Published: March 2008

AbstractWe are investigating effects of the depsipeptide geodiamolide H, isolated from the Brazilian sponge Geodia corticostylifera, on cancer cell lines grown in 3D environment. As shown previously geodiamolide H disrupts actin cytoskeleton in both sea urchin eggs and breast cancer cell monolayers. We used a normal mammary epithelial cell line MCF 10A that in 3D assay results formation of polarized spheroids. We also used cell lines derived from breast tumors with different degrees of differentiation: MCF7 positive for estrogen receptor and the Hs578T, negative for hormone receptors. Cells were placed on top of Matrigel. Spheroids obtained from these cultures were treated with geodiamolide H. Control and treated samples were analyzed by light and confocal microscopy. Geodiamolide H dramatically affected the poorly differentiated and aggressive Hs578T cell line. The peptide reverted Hs578T malignant phenotype to polarized spheroid‐like structures. MCF7 cells treated by geodiamolide H exhibited polarization compared to controls. Geodiamolide H induced striking phenotypic modifications in Hs578T cell line and disruption of actin cytoskeleton. We investigated effects of geodiamolide H on migration and invasion of Hs578T cells. Time‐lapse microscopy showed that the peptide inhibited migration of these cells in a dose‐dependent manner. Furthermore invasion assays revealed that geodiamolide H induced a 30% decrease on invasive behavior of Hs578T cells. Our results suggest that geodiamolide H inhibits migration and invasion of Hs578T cells probably through modifications in actin cytoskeleton. The fact that normal cell lines were not affected by treatment with geodiamolide H stimulates new studies towards therapeutic use for this peptide. J. Cell. Physiol. 216: 583–594, 2008, © 2008 Wiley‐Liss, Inc.
The effect of solvents on the rate of catalytic hydrogenation of 6‐ethyl‐1,2,3,4‐tetrahydroanthracene‐9,10‐dione
Authors: Fajt Vojtěch , Kurc Ladislav , Červený Libor 
Published: March 2008

AbstractThe rate of hydrogenation of 6‐ethyl‐1,2,3,4‐tetrahydroanthracene‐9,10‐dione was investigated at 313 K and 0.1 MPa in 20 solvents. A multiple linear regression was used to describe the solvent effect. The regression of the reaction rates was carried out using two five‐parameter linear regression models: the Abraham–Kamlet–Taft (AKT) and the Koppel–Palm (KP) model. After the elimination of the insignificant terms from the regression models, it was found that the basic character of the solvent and its Hildebrand cohesion energy density were the most important attributes influencing the hydrogenation rate. The analysis of both models led to the same conclusion. The resultant simplified AKT model gave closer fitting in comparison to the KP model. The results could facilitate the solvent selection for the industrial process of hydrogen peroxide production by the anthraquinone method with respect to the kinetics of anthraquinone hydrogenation. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 240–252, 2008
Micellar effect on quinquivalent vanadium ion oxidation of D‐glucose in aqueous acid media: A kinetic study
Authors: Saha Bidyut , Sarkar Sucharita , Chowdhury Kiran M. 
Published: March 2008

AbstractVanadium(V) oxidation of D‐glucose shows first‐order dependence on D‐glucose, vanadium(V), H+, and HSO. These observations remain unaltered in the presence of externally added surfactants. The effect of the cationic surfactant (i.e., N‐cetylpyridinium chloride [CPC]), anionic surfactant (i.e., sodium dodecyl sulfate [SDS]), and neutral surfactant (i.e., Trion X‐100 [TX‐100]) has been studied. CPC inhibits the reactions, whereas SDS and TX‐100 accelerate the reaction to different extents. Observed effects have been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 282–286, 2008
Pulse compression techniques using highly nonlinear fibers
Authors: Inoue T. , Namiki S. 
Published: March 2008

AbstractWe review optical pulse compression techniques based on optical fibers. After discussing the fundamental issues on pulse compression, we summarize and categorize various kinds of techniques for pulse compression. We then focus on the use of highly nonlinear fiber (HNLF) in a pulse compressor to improve the performance. Introducing a figure of merit, we discuss which kind of HNLF of those recently reported is the most suitable for applications to pulse compression. As a HNLF‐based optical pulse compressor, we review the technologies of the comb‐like profiled fiber (CPF) which consists of alternate concatenations of HNLF and single‐mode fiber. Discussing the features of CPF, we show that CPF is a truly practical and flexible solution for optical pulse compression. Finally, we refer to a new class of pulse compression called “the stationary rescaled pulse (SRP)”, which is a characteristic nonlinear stationary pulse propagating through CPF. The propagation characteristics of the SRP provides a systematic and efficient design method of CPF as well as optical pulse compression that has never been achieved by conventional pulse compression schemes. As an example, a highly steep pulse compression in CPF is demonstrated, where a pulse is compressed by a factor of 2.1 per step of the CPF, and a 7.2 ps‐width optical pulse is compressed to 0.38 ps with a four‐step structure of CPF.
Recent progress in multiphoton microfabrication
Authors: Maruo S. , Fourkas J.T. 
Published: March 2008

AbstractMultiphoton microfabrication enables the production of three‐dimensional microstructures with sub‐100 nm resolution via direct laser writing using a femtosecond, pulsed laser beam. The range of materials available for multiphoton processing has increased steadily over the past decade, and the extent of potential applications has increased correspondingly. Current application areas include photonics, microelectromechanical systems, and microelectronics. We review the fundamentals of multiphoton microfabrication and recent progress on materials and applications. Approaches for the mass production of three‐dimensional structures created with multiphoton fabrication are also discussed.
A completeness theorem for a dissipative Schrödinger problem with the spectral parameter in the boundary condition
Authors: Ongun M. Yakít , Allahverdiev Bilender P. 
Published: March 2008

AbstractIn this paper we consider a dissipative Schrödinger boundary value problem in the limit‐circle case with the spectral parameter in the boundary condition. The approach is based on the use of the maximal dissipative operator, and the spectral analyzes of this operator is adequate for the boundary value problem to be solved. We construct a self‐adjoint dilation of the maximal dissipative operator and its incoming and outgoing spectral representations, which make it possible to determine the scattering matrix of the dilation. We also construct a functional model of the maximal dissipative operator and define its characteristic function in terms of solutions of the corresponding Schrödinger equation. We prove theorems on the completeness of the system of eigenvectors and associated vectors of the maximal dissipative operator and the Schrödinger boundary value problem. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure–property relationships of low dielectric constant, nanoporous, thermally stable polyimides via grafting of poly(propylene glycol) oligomers
Authors: Mehdipour‐Ataei Shahram , Saidi Samaneh 
Published: March 2008

AbstractSynthesis of high temperature polyimide foams with pore sizes in the nanometer range was developed. Foams were prepared by casting graft copolymers comprising a thermally stable block as the matrix and a thermally labile material as the dispersed phase. The copolyimides as the matrix material were prepared via polycondensation reactions of pyromellitic dianhydride with three new diamines (4BAP, 3BAP, and BAN) through the poly(amic acid) precursors. Functionalized poly(propylene glycol) (PPGBr‐1000 and PPGBr‐2500) as the labile oligomer was prepared via reaction of poly(propylene glycol) monobutyl ether with 2‐bromoacetyl bromide. Graft copolymers were prepared by the reaction of the poly(amic acid)s with these thermally labile constituents. Upon thermal treatment the labile blocks were subsequently removed leaving pores with the size and shape of the original copolymer morphology. The polyimides and foamed polyimides were characterized by some conventional methods including FTIR, H‐NMR, DSC, TGA, SEM, TEM, and dielectric constant. The average pore size of the polyimide nanofoams was in the range of 5–20 nm. The structure–property relationships of the prepared nanofoams were investigated based on the diamine structures and also molecular weights of labile groups. Copyright © 2008 John Wiley & Sons, Ltd.
Twin–twin transfusion syndrome: mathematical modelling
Authors: van den Wijngaard Jeroen P. H. M. , Umur Asli , Ross Michael G. , van Gemert Martin J. C. 
Published: March 2008

AbstractTwin–twin transfusion syndrome (TTTS) represents a pregnancy complication with a high risk for perinatal mortality and postnatal morbidity. Mathematical models have been utilized to examine the mechanisms of disease and potential treatment modalities. We developed four consecutive models based on pathophysiology mechanisms. Conceptually, these models remained simple, but with increased complexity in details. We present our models tutorially with the necessary equations expressed in words. The aetiology of TTTS was related to AV anastomoses from donor to recipient and their growth commensurate with placental growth. We assessed that natural growth of placenta and foetuses causes the diameter and length of the AV, as well as the AV's pressure gradient, to increase proportional to gestational age. The AV transfusion then increases faster than natural foetal growth. A progressively increasing discordance subsequently develops, not compensated for by foetal growth. A simulation is performed to show how this discordance in blood volumetric development causes successive discordances in other functions, particularly renal, circulatory, and cardio‐vascular, resulting in disease progression to the various stages of TTTS. In conclusion, mathematical modelling of TTTS has provided an understanding of the sequence of events that leads to the various presentations of TTTS stages as well as the efficacy of therapies. Copyright © 2008 John Wiley & Sons, Ltd.
Laser coagulation of placental anastomoses with a 30° fetoscope in severe mid‐trimester twin–twin transfusion syndrome with anterior placenta
Authors: Huber A. , Baschat A. A. , Bregenzer T. , Diemert A. , Tchirikov M. , Hackelöer B. J. , Hecher K. 
Published: March 2008

AbstractObjectiveTo assess outcome after fetoscopic laser coagulation (FLC) of placental vascular anastomoses with the 30° fetoscope in mid‐trimester severe twin‐to‐twin transfusion syndrome (TTTS) with completely anterior placenta compared with the regular 0° fetoscope in TTTS with other placental locations.MethodsThis was a prospective study of 176 consecutive monochorionic twin pregnancies undergoing FLC for severe TTTS. Of these, 51 patients required use of the 30° fetoscope (study group) and 125 placental locations permitted use of the 0° fetoscope (controls).ResultsThe two groups had very similar outcomes. The median gestational age at FLC in the study group vs. control group was 21.0 (range, 17.4–24.6) weeks vs. 20.6 (range, 15.9–24.6) weeks. Both fetuses survived in 58.8% (30/51) of study patients vs. 66.4% (83/125) of controls. At least one fetus survived in 84.3% (43/51) of study patients and 88.8% (111/125) of controls (P = 0.45). Study patients delivered at a median of 34.1 (range, 25.0–38.4) weeks and controls at 34.0 (range, 25.0–40.3) weeks' gestation.ConclusionsUse of a 30° fetoscope for FLC in cases of technically challenging extensive anterior placentation is associated with an outcome that is very similar to that achieved when a 0° fetoscope is used in cases of more favorable placental location. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Assessment of aerosol particles within the Rubens' House Museum in Antwerp, Belgium
Authors: Godoi Ricardo Henrique Moreton , Potgieter‐Vermaak Sanja , Godoi Ana Flavia Locateli , Stranger Marianne , Van Grieken Rene 
Published: March 2008

AbstractThe majority of researchers, conservators and curators recognise that atmospheric pollution is one of the major threats to works of art. In principle, all atmospheric particles, when deposited onto art objects can be considered harmful because of their potential in causing deterioration. Moreover, under certain conditions, particulate matter can induce and intensify surface damage, particularly because of its potential to serve as centre for moisture condensation and adsorbent of gaseous pollutants. To investigate the potential harm that these particles can cause, comprehensive characterisation of the particulate matter is necessary. Particulate matter was collected at the Rubens' House Museum in Antwerp, Belgium, where a unique exhibit of the paintings and living quarters of Peter Paul Rubens (1577–1640) are seen. Size segregated aerosol samples were collected for analyses of bulk and single particle elemental and molecular compositions. They were analysed by electron probe micro‐analysis, utilising facilities for low‐Z element determination, and by energy‐dispersive x‐ray fluorescence, to investigate the elemental composition of individual particles and bulk samples, and by micro Raman spectrometry, to elucidate the molecular composition. Results are interpreted separately and as a whole with the specific aim of identifying compounds that could contribute to the chemical reactions taking place on the surfaces of artefacts and which could potentially cause degradation of the objects. Copyright © 2008 John Wiley & Sons, Ltd.
The Saccharomyces cerevisiae CLB5 promoter contains two middle sporulation elements (MSEs) that are differentially regulated during sporulation
Authors: Raithatha Sheetal A. , Stuart David T. 
Published: March 2008

AbstractThe B‐type cyclins Clb5 and Clb6 are essential activators of DNA replication during sporulation in Saccharomyces cerevisiae. The expression of CLB5 is maximally induced during the middle phase of sporulation by the transcription factor Ndt80. We have performed an analysis of the CLB5 promoter and have identified two middle sporulation elements (MSEs) that act as binding sites for Ndt80. Although both MSE sequences bind Ndt80 in vitro, they display differential effectiveness in their ability to function as cis‐acting regulatory sequences in vivo. Mutation of both MSE sequences in the CLB5 promoter profoundly reduces the induction of CLB5 transcription during the middle phase of sporulation but results in no obvious defect in progression through meiosis and sporulation, implying that the Ndt80‐dependent induction of CLB5 is not required for effective DNA replication or chromosome division. Copyright © 2008 John Wiley & Sons, Ltd.