bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Reactivity of Six‐Membered Oxa‐Nickelacycles: A Ring‐Opening Reaction of Cyclopropyl Ketones
Authors: Tamaki Takashi , Nagata Midue , Ohashi Masato , Ogoshi Sensuke 
Published: August 2009

AbstractCyclopropanecarboxaldehyde (1 a), cyclopropyl methyl ketone (1 b), and cyclopropyl phenyl ketone (1 c) were reacted with [Ni(cod)2] (cod=1,5‐cyclooctadiene) and PBu3 at 100 °C to give η2‐enonenickel complexes (2 a–c). In the presence of PCy3 (Cy=cyclohexyl), 1 a and 1 b reacted with [Ni(cod)2] to give the corresponding μ‐η2:η1‐enonenickel complexes (3 a, 3 b). However, the reaction of 1 c under the same reaction conditions gave a mixture of 3 c and cyclopentane derivatives (4 c, 4 c′), that is, a [3+2] cycloaddition product of 1 c with (E)‐1‐phenylbut‐2‐en‐1‐one, an isomer of 1 c. In the presence of a catalytic amount of [Ni(cod)2] and PCy3, [3+2] homo‐cycloaddition proceeded to give a mixture of 4 c (76 %) and 4 c′ (17 %). At room temperature, a possible intermediate, 6 c, was observed and isolated by reprecipitation at −20 °C. In the presence of 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr), both 1 a and 1 c rapidly underwent oxidative addition to nickel(0) to give the corresponding six‐membered oxa‐nickelacycles (6 ai, 6 ci). On the other hand, 1 b reacted with nickel(0) to give the corresponding μ‐η2:η1‐enonenickel complex (3 bi). The molecular structures of 6 ai and 6 ci were confirmed by X‐ray crystallography. The molecular structure of 6 ai shows a dimeric η1‐nickelenolate structure. However, the molecular structure of 6 ci shows a monomeric η1‐nickelenolate structure, and the nickel(II) 14‐electron center is regarded as having “an unusual T‐shaped planar” coordination geometry. The insertion of enones into monomeric η1‐nickelenolate complexes 6 c and 6 ci occurred at room temperature to generate η3‐oxa‐allylnickel complexes (8, 9), whereas insertion into dimeric η1‐nickelenolate complex 6 ai did not take place. The diastereoselectivity of the insertion of an enone into 6 c having PCy3 as a ligand differs from that into 6 ci having IPr as a ligand. In addition, the stereochemistry of η3‐oxa‐allylnickel complexes having IPr as a ligand is retained during reductive elimination to yield the corresponding [3+2] cycloaddition product, which is consistent with the diastereoselectivity observed in Ni0/IPr‐catalyzed [3+2] cycloaddition reactions of cyclopropyl ketones with enones. In contrast, reductive elimination from the η3‐oxa‐allylnickel having PCy3 as a ligand proceeds with inversion of stereochemistry. This is probably due to rapid isomerization between syn and anti isomers prior to reductive elimination.
Tetraaryl Tetradecahydroporphyrazins: Novel Porphyrin Derivatives Featuring a Cyclic Benzene‐Ring Tetramer
Authors: Janich Simon , Fröhlich Roland , Wakamiya Atsushi , Yamaguchi Shigehiro , Würthwein Ernst‐Ulrich 
Published: August 2009

AbstractTreatment of tetramethylsuccinonitrile 1 with aryl lithium compounds and subsequent quenching with chlorotrimethylsilane yields 5‐aryl‐3,3,4,4‐tetramethyl‐N‐(trimethylsilyl)‐3,4‐dihydropyrrol‐2‐imines 2 a–c in 49–71 % yield. Attempts to crystallise 2 a–c in the presence of wet air yielded the tetraaryl tetradecahydroporphyrazins 3 a–c in yields of 4–84 % as single diastereomers. X‐ray diffraction studies of 3 b and c showed that only the isomer with four aryl substituents pointing in the same direction was formed. The resulting four‐bladed pinwheel‐like structures were characterised by four intramolecular aromatic interactions, in which each phenyl ring points with its edge towards the centre of a neighbouring phenyl moiety, resembling the arrangement of benzene molecules in T‐shaped dimers. Temperature‐dependent NMR spectra give insight into the dynamic properties of the aryl substituents. Quantum chemical calculations that included dispersion corrections indicated the importance of aryl–aryl interactions for the diastereoselectivity of the reaction and for the structural properties of the single isomers observed.
The Stereospecific Ligand Exchange at a Pseudo‐Benzylic T‐4 Iridium Centre in Planar‐Chiral Cycloiridium (η6‐Arene)tricarbonylchromium Complexes
Authors: Djukic Jean‐Pierre , Boulho Cédric , Sredojevic Dusan , Scheeren Carla , Zaric Snezana , Ricard Louis , Pfeffer Michel 
Published: August 2009

AbstractThe stereospecificity of ligand exchange at the IrIII centre of a cycloiridium arenetricarbonylchromium complex has been established experimentally by various analytical methods as well as by X‐ray diffraction structural analysis and computational investigations. Two new cases of phenyl and methyl iridium(III) complexes have been prepared by reaction of (${S{{{\ast}\hfill \atop {\rm p}\hfill}}}$,${R{{{\ast}\hfill \atop {\rm Ir}\hfill}}}$)‐chlorido{2‐[(tricarbonyl)(η6‐phenylene‐κC1′)chromium(0)]pyridine‐κN}(pentamethylcyclopentadienyl)iridium(III) with PhMgBr and MeMgBr. The determining influence of electrostatic repulsion has been established by means of density functional theory at the Becke–Perdew/TZP(ZORA) level by using, among other means, energy partitioning analysis. It is also shown that the Cr(CO)3 fragment is likely to ease the ionic cleavage of the IrCl bond in chlorido cycloiridium tricarbonylchromium complexes in a way similar to that already established for the solvolysis of benzyl halide complexes, that is, through a direct interaction of the Cr0 centre with the cationic IrIII centre.
Copper‐Catalyzed Asymmetric Conjugate Addition with Chiral SimplePhos Ligands
Authors: Palais Laëtitia , Alexakis Alexandre 
Published: August 2009

AbstractSimplePhos ligands represent a novel class of monodentate chiral ligands based on a chiral amine moiety and flexible diaryl groups on the phosphorous atom. They can be easily prepared by two different pathways and they can be highly functionalised. Herein we report the copper‐catalysed asymmetric conjugate addition of diethyl zinc and trialkylaluminium reagents with SimplePhos ligands, which gives high enantioselectivity with cyclic enones, acyclic enones and nitro‐olefins, with up to 98.6 % ee. Of particular interest is the reaction of trialkylaluminium reagents with a wide range of 3‐substituted enones, thus allowing the formation of stereogenic quaternary carbon centres.
Myosin‐X is required for cranial neural crest cell migration in Xenopus laevis
Authors: Hwang Yoo‐Seok , Luo Ting , Xu Yanhua , Sargent Thomas D. 
Published: August 2009

AbstractMyosin‐X (MyoX) belongs to a large family of unconventional, nonmuscle, actin‐dependent motor proteins. We show that MyoX is predominantly expressed in cranial neural crest (CNC) cells in embryos of Xenopus laevis and is required for head and jaw cartilage development. Knockdown of MyoX expression using antisense morpholino oligonucleotides resulted in retarded migration of CNC cells into the pharyngeal arches, leading to subsequent hypoplasia of cartilage and inhibited outgrowth of the CNC‐derived trigeminal nerve. In vitro migration assays on fibronectin using explanted CNC cells showed significant inhibition of filopodia formation, cell attachment, spreading and migration, accompanied by disruption of the actin cytoskeleton. These data support the conclusion that MyoX has an essential function in CNC migration in the vertebrate embryo. Developmental Dynamics 238:2522–2529, 2009. © Published 2009 Wiley‐Liss, Inc.†
The relationships between body mass index and television viewing, internet use and cellular phone use: The moderating effects of socio‐demographic characteristics and exercise
Authors: Yen Cheng‐Fang , Hsiao Ray C. , Ko Chih‐Hung , Yen Ju‐Yu , Huang Chi‐Fen , Liu Shu‐Chun , Wang Shing‐Yaw 
Published: August 2009

AbstractObjectiveThis study aimed to examine the relationships between body mass index (BMI) and television viewing, Internet use and cellular phone use and the moderators for these relationships in adolescents.MethodThe relationship between BMI and the time spent on three kinds of sedentary activities and the moderators for these relationships were analyzed among 9,278 Taiwanese adolescents. The different relationships between BMI and various Internet and cellular phone‐related activities were analyzed.ResultsHigh television viewing and high Internet use were associated with increased BMI in adolescents. Exercising had a moderating effect on the relationship between BMI and television viewing. Several Internet and cellular phone‐related activities were associated with increased BMI.DiscussionThe results support the relationships between adolescent BMI and television viewing and Internet use. The moderating effect of exercise and various Internet and cellular phone‐related activities should be considered when developing intervention strategies for overweight adolescents. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010; 43:565–571
Factors associated with body dissatisfaction and disordered eating in women in midlife
Authors: McLean Siân A. , Paxton Susan J. , Wertheim Eleanor H. 
Published: August 2009

AbstractObjectiveIn this study, we examined developmentally appropriate factors that may be associated with body dissatisfaction and disordered eating in women in midlife.MethodParticipants were a community sample of 200 women aged 35–65. Outcome measures were the weight concern, shape concern, eating concern, and restraint subscales of the Eating Disorder Examination–Questionnaire (EDE‐Q). Independent variables were importance of appearance, importance of function, cognitive reappraisal (of aging changes to appearance), and body‐related self‐care.ResultsImportance of appearance, self‐care, and body mass index (BMI) accounted for variance in regression modeling for all EDE‐Q variables. In addition, cognitive reappraisal was related to shape concern and restraint, and importance of function and age were also associated with restraint. Participants identified as probable eating disorder cases had significantly higher BMI, importance of appearance and function, and significantly lower cognitive reappraisal and self‐care scores than participants identified as noncases.DiscussionThis study provides support for the role of developmentally relevant factors in body dissatisfaction and disordered eating in midlife women. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010; 43:527–536
Twenty‐year follow‐up of bulimia nervosa and related eating disorders not otherwise specified
Authors: Keel Pamela K. , Gravener Julie A. , Joiner Thomas E. , Haedt Alissa A. 
Published: August 2009

AbstractObjectiveThis study reports 20‐year outcome of bulimia nervosa (BN) and related eating disorders not otherwise specified (EDNOS) and point prevalence of BN and EDNOS for a cohort of women and men in late adolescence (mean age = 20 ± 2 years), adulthood (30 ± 2 years), and mid‐life (40 ± 2 years).MethodN = 654 women and men, 73% of those assessed in 1982, completed 20‐year follow‐up in a two‐stage design including questionnaires and structured clinical interviews.ResultsApproximately 75% of women with BN were in remission at 20‐year follow‐up, and outcome did not differ significantly between BN and EDNOS. Eating disorder point prevalence declined in women but not men from late adolescence to mid‐life.DiscussionDespite patterns of improvement in women, 4.5% reported a clinically significant eating disorder at mid‐life, suggesting the need for more research on potential risk factors in this age group, such as pressures for women to maintain a youthful appearance. © 2009 by Wiley Periodicals, Inc. Int J Eat Disord 2010; 43:492–497
Interpersonal problems in eating disorders
Authors: Hartmann Armin , Zeeck Almut , Barrett Marna S. 
Published: August 2009

AbstractObjective:Eating disorders are often chronic in nature and lead to a number of problems among which interpersonal issues are suggested to be central. Although research has shown that individuals with disturbed patterns of eating consistently report problems in social interactions, this study is unique in assessing a range of interpersonal problems among patients with all types of eating disorders before and after intensive hospital‐based treatment.Method:A total of 208 patients receiving a primary diagnosis of restrictive anorexia nervosa, bulimia nervosa, or anorexia nervosa of the binge/purging‐subtype were included in the study. Eating pathology, symptom severity, and interpersonal patterns were examined before and after treatment.Results:Patients with eating disorders exhibited a generally nonassertive, submissive interpersonal style, with anorexic patients of the binge/purging‐subtype reporting more difficulties with social inhibition and nonaffiliation. These patterns were found to change over the course of treatment with interpersonal problems at intake predictive of greater binge severity at discharge. Furthermore, issues of dominance and social avoidance predicted outcome for specific subgroups of patients.Discussion:Results underscore the importance of interpersonal problems in eating disorders and suggest that interpersonal patterns remain a focus of treatment and future research. © 2009 by Wiley Periodicals, Inc. (Int J Eat Disord 2010;)
Advances in the Universal NMR Database: Toward the Determination of the Relative Configurations of Large Polypropionates
Authors: Fleury Etienne , Lannou Marie‐Isabelle , Bistri Olivia , Sautel François , Massiot Georges , Pancrazi Ange , Ardisson Janick 
Published: August 2009

AbstractThe relative stereochemical determination of naturally occurring large polyketides has proved to be critical, especially when the polyketides are available only in small quantities. Difficulties are often circumvented by the tedious synthesis either of adapted compound libraries (databases) or of all the presumed structures, because both methods allow efficient NMR comparison. To predict the stereochemistries of these frameworks, we have developed a straightforward method requiring neither the derivatisation of the natural product nor the synthesis of a new database of model stereoisomers. With the aid of 13C NMR spectroscopy, the relative configurations of the considered polypropionate segments are determined through a statistical UDB analysis of each included tetrad subunit followed by superposition of all predicted relative configurations of these tetrads. Examination of the different tetrads by statistical analysis consists of alternatively ruling out the Δδ values at positions where γ and δ effects could interfere. In most cases this statistical 13C NMR UDB approach leads to the stereochemical assignment of large polypropionate structures in a reliable way. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Forecasting using targeted diffusion indexes
Authors: Dias Francisco , Pinheiro Maximiano , Rua António 
Published: August 2009

AbstractThe simplicity of the standard diffusion index model of Stock and Watson has certainly contributed to its success among practitioners, resulting in a growing body of literature on factor‐augmented forecasts. However, as pointed out by Bai and Ng, the ranked factors considered in the forecasting equation depend neither on the variable to be forecast nor on the forecasting horizon. We propose a refinement of the standard approach that retains the computational simplicity while coping with this limitation. Our approach consists of generating a weighted average of all the principal components, the weights depending both on the eigenvalues of the sample correlation matrix and on the covariance between the estimated factor and the targeted variable at the relevant horizon. This ‘targeted diffusion index’ approach is applied to US data and the results show that it outperforms considerably the standard approach in forecasting several major macroeconomic series. Moreover, the improvement is more significant in the final part of the forecasting evaluation period. Copyright © 2009 John Wiley & Sons, Ltd.
Executive function and error detection: The effect of motivation on cingulate and ventral striatum activity
Authors: Simões‐Franklin Cristina , Hester Robert , Shpaner Marina , Foxe John J. , Garavan Hugh 
Published: August 2009

AbstractReacting appropriately to errors during task performance is fundamental to successful negotiation of our environment. This is especially true when errors will result in a significant penalty for the person performing a given task, be they financial or otherwise. Error responses and monitoring states were manipulated in a GO/NOGO task by introducing a financial punishment for errors. This study employed a mixed block design alternating between punishment and no punishment (neutral) conditions, enabling an assessment of tonic changes associated with cognitive control as well as trial‐specific effects. Behavioural results revealed slower responses and fewer commission errors in the punishment condition. The dorsal anterior cingulate cortex (ACC) had equal trial‐specific activity for errors in the neutral and punishment conditions but had greater tonic activity throughout the punishment condition. A region of interest analysis revealed different activation patterns between the dorsal and the rostral parts of the ACC with the rostral ACC having only trial‐specific activity for errors in the punishment condition, an activity profile similar to one observed in the nucleus accumbens. This study suggests that there is a motivational influence on cognitive processes in the ACC and nucleus accumbens and hints at a dissociation between tonic proactive activity and phasic reactive error‐related activity. Hum Brain Mapp, 2010. © 2009 Wiley‐Liss, Inc.
Spreading of mesothelioma cells is rapamycin‐sensitive and requires continuing translation
Authors: Ranzato Elia , Grosso Stefano , Patrone Mauro , Betta Pier Giacomo , Viarengo Aldo , Biffo Stefano 
Published: August 2009

AbstractThe interaction of cancer cells with extracellular matrix (ECM) is important in metastasization. Here we identified the molecules of the ECM expressed by sarcomatous malignant mesothelioma, and their effect on adhesion and spreading. In addition, by analyzing the relationship between translation and attachment to matrix, we found that mesothelioma cells rely on continuing translation to efficiently attach to matrix, and rapamycin inhibition affects spreading and migration of cancer cells. Specifically, we found that sarcomatous cells produce high amounts of fibronectin, able to support the spreading of mesothelioma cells. Spreading of cancer cells on fibronectin does not require de novo transcription but is sensitive to cycloheximide, an inhibitor of protein synthesis. Next, we analyzed the involvement of the mammalian target of rapamycin (mTOR) pathway, a major pathway controlling translation. Cancer cells have a constitutively active mTOR pathway; surprisingly, inhibition of mTOR complex 1 (mTORC1) by rapamycin barely affects the global rate of translation and of initiation of translation, but deeply inhibits mesothelioma spreading on ECM. The effects of rapamycin and cycloheximide on spreading were observed in several mesothelioma cell lines, although with different magnitude. Overall, data suggest that adhesion and spreading of mesothelioma cells on ECM require the translation of pre‐synthesized mRNAs, and mTORC1 activity. We speculate that mTORC1 activity is required either for the translation of specific mRNAs or for the direct modulation of cytoskeletal remodeling. J. Cell. Biochem. 108: 867–876, 2009. © 2009 Wiley‐Liss, Inc.
Upregulation of MUC5AC gene expression by IL‐4 through CREB in Human airway epithelial cells
Authors: Kim Cheol Hong , Kim Kyu‐Earn , Yoon Joo‐Heon , Song Kyoung Seob 
Published: August 2009

AbstractMucus hypersecretion is an important characteristic feature of the pathogenesis of allergy. Although interleukin (IL)‐4 is known to be an inflammatory mediator in respiratory diseases, the mechanism by which IL‐4 induces MUC5AC gene expression has not been fully explored. The aim of this study was to investigate the mechanism by which IL‐4 induces MUC5AC gene expression in the airway. We examined the role of mitogen‐activated protein kinase (MAPK) signaling on MUC5AC gene expression in airway epithelium. We showed that phosphorylation of ERK1/2 increased after treatment of cells with IL‐4, whereas phosphorylation of p38 and JNK was not detected. In addition, pharmacologic and genetic inhibition of ERK1/2 abolished IL‐4‐induced MUC5AC gene expression. Moreover, we investigated the activation of p90 ribosomal S6 kinase 1 (RSK1) as a downstream signaling target of ERK1/2 in IL‐4 signaling. The activation of RSK1 was prevented by pretreatment with PD98059 or plasmid expressing a MEK1 dominant‐negative mutant. We also found that RSK1 mediated the IL‐4‐induced phosphorylation of cAMP response element‐binding protein (CREB) and the transcription of MUC5AC. Furthermore, the cAMP‐response element (CRE) in the MUC5AC promoter appears to be important for IL‐4‐induced MUC5AC gene expression in NCI‐H292 cells. J. Cell. Biochem. 108: 974–981, 2009. © 2009 Wiley‐Liss, Inc.
High affinity binding between Hsp70 and the C‐terminal domain of the measles virus nucleoprotein requires an Hsp40 co‐chaperone
Authors: Couturier Marie , Buccellato Matt , Costanzo Stéphanie , Bourhis Jean‐Marie , Shu Yaoling , Nicaise Magali , Desmadril Michel , Flaudrops Christophe , Longhi Sonia , Oglesbee Michael 
Published: August 2009

AbstractThe major inducible 70 kDa heat shock protein (hsp70) binds the measles virus (MeV) nucleocapsid with high affinity in an ATP‐dependent manner, stimulating viral transcription and genome replication, and profoundly influencing virulence in mouse models of brain infection. Binding is mediated by two hydrophobic motifs (Box‐2 and Box‐3) located within the C‐terminal domain (NTAIL) of the nucleocapsid protein, with NTAIL being an intrinsically disordered domain. The current work showed that high affinity hsp70 binding to NTAIL requires an hsp40 co‐chaperone that interacts primarily with the hsp70 nucleotide binding domain (NBD) and displays no significant affinity for NTAIL. Hsp40 directly enhanced hsp70 ATPase activity in an NTAIL‐dependent manner, and formation of hsp40–hsp70–NTAIL intracellular complexes required the presence of NTAIL Box‐2 and 3. Results are consistent with the functional interplay between hsp70 nucleotide and substrate binding domains (SBD), where ATP hydrolysis is rate limiting to high affinity binding to client proteins and is enhanced by hsp40. As such, hsp40 is an essential variable in understanding the outcome of MeV–hsp70 interactions. Copyright © 2009 John Wiley & Sons, Ltd.
Imaging of single GaN nanowires by tip‐enhanced Raman spectroscopy
Authors: Marquestaut N. , Talaga D. , Servant L. , Yang P. , Pauzauskie P. , Lagugné‐Labarthet F. 
Published: August 2009

AbstractRaman imaging of a single [110] GaN nanowire using a combination of an atomic force microscope (AFM) and an inverted confocal microscope was investigated. The Raman spectra and associated maps of this single object, the diameter of which was of 200 nm, were collected in both confocal mode and with the interaction of an AFM tip to benefit from local tip enhancement effect. Beyond the pure tip‐enhanced Raman scattering (TERS) effect, the setup was developed to integrate a commercial AFM and spectrometer to permit simultaneous topography and vibrational imaging with spatial and spectral resolutions determined by the respective instruments. Data exchange and communication of the Raman spectrometer and the AFM were optimized to display both height and Raman intensity for a set of Z positions at the AFM tip for each (x,y) position on the sample. The experiments were conducted with both a straight tip coated with gold at an excitation of λ = 647 nm and with a tilted tip coated with silver at an excitation wavelength of λ = 514 nm. The TERS signal was observed for a given phonon mode of the [110] nanowire, providing an optical resolution that corresponds to the size of the object. Copyright © 2009 John Wiley & Sons, Ltd.