bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of a Molecular Hourglass: Synthesis and Magnetic Characterisation of a Cyclic Dodecanuclear {Cr10Cu2} Complex
Authors: Shanmugam Muralidharan , Engelhardt Larry P. , Larsen Finn K. , Luban Marshall , McInnes Eric J. L. , Muryn Christopher A. , Overgaard Jacob , Rentschler Eva , Timco Grigore A. , Winpenny Richard E. P. 
Published: September 2006

AbstractThe synthesis, structure, EPR, and magnetic studies of two dodecanuclear heterometallic cyclic clusters are reported. The compounds have the general formula [R2NH2]2[Cr10Cu2F14(O2CCMe3)22] (R=Me, 1 or iPr, 2). Both structures contain an array of metal centers which describe an approximate “hourglass”, with an ammonium cation in the center of each half of the figure. The chromium sites are all six‐coordinate, with the two copper sites five‐coordinate. The majority of metal–metal edges are bridged by a single fluoride and two pivalate ligands, while two CrCu edges are bridged by a single fluoride and a single pivalate. Magnetic studies show that 1 and 2 exhibit similar (but not identical) behavior, which can be attributed to ten antiferromagnetic and two ferromagnetic exchange interactions around the ring which gives an S=0 ground state. Quantum Monte Carlo calculations have been used to quantify the exchange interactions by successfully simulating the susceptibility for the full temperature range and thus clarifying the distinction between 1 and 2. EPR spectroscopy shows signals due to excited states, and a variable‐temperature study has provided an estimate of the energy gap between the first excited state (S=1) and second excited state (S=2) for 1 that is consistent with the value obtained using the QMC method.
Mo15S20: First Evidence of a New Molybdenum Cluster Type in a Metastable Solid‐State Compound
Authors: Salloum Dialla , Gautier Régis , Potel Michel , Gougeon Patrick 
Published: September 2006

AbstractThe Mo15S20 compound was obtained by thermal decomposition of the metastable binary Mo15S19 in sealed silica tube at temperatures above 500 °C. Its crystal structure was solved and refined from a two‐component composite crystal by X‐ray diffraction in the hexagonal space group P63/m and consists of an equal mixture of the original Mo9S27 cluster unit and the classical one Mo6S8S6 interconnected through MoS bonds. The Mo core of the Mo9S27 unit is totally new and formed a tricapped trigonal prism. Quantum chemical calculations carried out in order to understand these trends as well as magnetic susceptibility measurements are also reported. The title compound becomes superconducting below 5 K.
Cultured endothelial cells display endogenous activation of the canonical Wnt signaling pathway and express multiple ligands, receptors, and secreted modulators of Wnt signaling
Authors: Goodwin Anne M. , Sullivan Kaitlyn M. , D'Amore Patricia A. 
Published: September 2006

AbstractA growing body of evidence implicates Wnt signaling in the control of angiogenesis. To better understand the role of the Wnt/β‐catenin pathway in endothelial cells (EC), we examined endogenous signaling activity and signaling component expression in vascular cells. We observed stabilization of cytosolic β‐catenin and activation of a T‐cell factor (TCF) ‐luciferase promoter, hallmarks of canonical Wnt signaling activity, in cultured EC. This activity was increased in subconfluent EC, which are known to display characteristics of angiogenic EC, compared with confluent EC, which have a more differentiated phenotype. Endogenous TCF activity was inhibited by transfection with a secreted inhibitor of canonical Wnt signaling. A systematic analysis of Wnt, Fzd, SFRP, and Dkk gene expression in human EC (cultured and freshly isolated), smooth muscle cells (cultured), and aorta demonstrated that numerous Wnt signaling components are expressed by vascular cells. We conclude that Wnt signaling components are expressed and active in cultured EC. Developmental Dynamics 235:3110–3120, 2006. © 2006 Wiley‐Liss, Inc.
The RNA binding protein Zfp36l1 is required for normal vascularisation and post‐transcriptionally regulates VEGF expression
Authors: Bell Sarah E. , Sanchez Maria Jose , Spasic‐Boskovic Olivera , Santalucia Tomas , Gambardella Laure , Burton Graham J. , Murphy John J. , Norton John D. , Clark Andrew R. , Turner Martin 
Published: September 2006

AbstractThe Zfp36l1 gene encodes a zinc finger‐containing mRNA binding protein implicated in the posttranscriptional control of gene expression. Mouse embryos homozygous for a targeted mutation in the Zfp36l1 locus died mid‐gestation and exhibited extraembryonic and intraembryonic vascular abnormalities and heart defects. In the developing placenta, there was a failure of the extraembryonic mesoderm to invaginate the trophoblast layer. The phenotype was associated with an elevated expression of vascular endothelial growth factor (VEGF)‐A in the embryos and in embryonic fibroblasts cultured under conditions of both normoxia and hypoxia. VEGF‐A overproduction by embryonic fibroblasts was not a consequence of changes in Vegf‐a mRNA stability; instead, we observed enhanced association with polyribosomes, suggesting Zfp36l1 influences translational regulation. These data implicate Zfp36l1as a negative regulator of Vegf‐a gene activity during development. Developmental Dynamics 235:3144–3155, 2006. © 2006 Wiley‐Liss, Inc.
Quantitative volumetric analysis of cardiac morphogenesis assessed through micro‐computed tomography
Authors: Butcher Jonathan T. , Sedmera David , Guldberg Robert E. , Markwald Roger R. 
Published: September 2006

AbstractWe present a method to generate quantitative embryonic cardiovascular volumes at extremely high resolution without tissue shrinkage using micro‐computed tomography (Micro‐CT). A CT dense polymer (Microfil, Flow Tech, Inc.) was used to perfuse avian embryonic hearts from Hamburger and Hamilton stage (HH) 15 through HH36, which solidified to create a cast within the luminal space. Hearts were then scanned at 10.5 μm3 voxel resolution using a VivaCT scanner, digital slices were contoured for regions of interest, and computational analysis was conducted to quantify morphogenetic parameters. The three‐dimensional morphology was compared with that of scanning electron microscopy (SEM) images and serial section reconstruction of similarly staged hearts. We report that Microfil‐perfused hearts swelled to maximum end‐diastolic volume with negligible shrinking after polymerization. Comparison to SEM revealed good agreement of cardiac chamber proportions and intracardiac tissue structures (i.e., valves and septa) at the stages of development assessed. Quantification of changes in chamber volume over development revealed several notable results that confirm earlier hypotheses. Heart chamber volumes grow over two orders of magnitude during the 1‐week developmental period analyzed. The atrioventricular canal comprised a significant proportion of the early heart volume. While left atrium/left ventricular volume ratios approached 1 in later development, right atrium/right ventricle ratios increase to over 2.5. Quantification of trabeculation patterns confirmed that the right and left ventricles are similarly trabeculated before HH27, after which the right ventricle became quantitatively coarser than that of the left ventricle. These results demonstrate that Micro‐CT can be used to image and quantify cardiovascular structures during development. Developmental Dynamics 236:802–809, 2007. © 2006 Wiley‐Liss, Inc.
Dact1 presomitic mesoderm expression oscillates in phase with Axin2 in the somitogenesis clock of mice
Authors: Suriben Rowena , Fisher Daniel A. , Cheyette Benjamin N.R. 
Published: September 2006

AbstractDuring segmentation (somitogenesis) in vertebrate embryos, somites form in a rostral‐to‐caudal sequence according to a species‐specific rhythm called the somitogenesis clock. The expression of genes participating in somitogenesis oscillates in the presomitic mesoderm (PSM) in time with this clock. We previously reported that the Dact1 gene (aka Dpr1/Frd1/ThyEx3), which encodes a Dishevelled‐binding intracellular regulator of Wnt signaling, is prominently expressed in the PSM as well as in a caudal‐rostral gradient across the somites of mouse embryos. This observation led us to examine whether Dact1 expression oscillates in the PSM. We have found that Dact1 PSM expression does indeed oscillate in time with the somitogenesis clock. Consistent with its known signaling functions and with the “clock and wavefront” model of signal regulation during somitogenesis, the oscillation of Dact1 occurs in phase with the Wnt signaling component Axin2, and out of phase with the Notch signaling component Lfng. Developmental Dynamics 235:3177–3183, 2006. © 2006 Wiley‐Liss, Inc.
Expression of the AmphiTcf gene in amphioxus: Insights into the evolution of the TCF/LEF gene family during vertebrate evolution
Authors: Lin Hsiu‐Chin , Holland Linda Z. , Holland Nicholas D. 
Published: September 2006

AbstractT‐cell factor (TCF) and lymphoid enhancer factors (LEF) genes encode proteins that are transcription factors mediating β‐catenin/Wnt signaling. Whereas mammals have four such genes, the Florida amphioxus (Branchiostoma floridae) apparently has only one such gene (AmphiTcf). From cleavage through early gastrula, cytoplasmic maternal transcripts of this gene are localized toward the animal pole. In gastrulae, AmphiTcf expression begins in the mesendoderm. In neurulae, there is expression in the pharynx, hindgut, anterior notochord, somites, and at the anterior end of the neural plate. In early larvae, expression is detectable in the floor of the diencephalon, notochord, tail bud, forming somites, pharynx, and ciliated pit (a presumed homolog of the vertebrate adenohypophysis). Phylogenetic analysis of TCF/LEF proteins placed AmphiTcf as the sister group of a clade comprising vertebrate Tcf1, Lef1, Tcf3, and Tcf4. Comparison of developmental expression for amphioxus AmphiTcf and vertebrate TCF/LEF genes indicates that this gene family has undergone extensive subfunctionalization and neofunctionalization during vertebrate evolution. Developmental Dynamics 235:3396–3403, 2006. © 2006 Wiley‐Liss, Inc.
Transgenic mice for Cre‐inducible overexpression of the oncogenes c‐MYC and Pim‐1 in multiple tissues
Authors: Roh Meejeon , Kim Jongchan , Song Chisu , Wills Marcia , Abdulkadir Sarki A. 
Published: September 2006

AbstractThe transcription factor c‐MYC and the serine‐threonine kinase Pim‐1 have multiple roles in development and cancer, including in lymphomagenesis and prostate tumorigenesis. In some cancers, MYC and Pim‐1 oncogenes are co‐expressed and show marked cooperativity. To facilitate the analysis of the pathological roles of MYC and Pim‐1 in specific cell types and developmental stages, we generated mice carrying Cre‐inducible MYC/Pim‐1 transgenes. The mice carry a constitutively expressed lacZ marker and silent MYC/Pim‐1 genes. Cre‐mediated recombination results in deletion of the lacZ marker and concurrent activation of the MYC/Pim‐1 transgene. In addition, the Pim‐1 mice harbor an alkaline phosphatase gene as a positive marker for recombination. Mouse lines for each gene were established, which show distinct patterns of expression in multiple tissues. In vivo recombination was confirmed for all lines by breeding to Cre transgenic mice. These mice provide a valuable resource for investigating the significance of MYC and Pim‐1 overexpression in various tissues. genesis 44:447–453, 2006. © 2006 Wiley‐Liss, Inc.
Summary of ‘Interventions for promoting booster seat use in four to eight year olds traveling in motor vehicles’
Authors: Milne Andrea 
Published: September 2006

AbstractThis is a summary of a Cochrane review, published in this issue of EBCH, first published as: Ehiri JE, Ejere HOD, Magnussen L, Emusu D, King W, Osberg JS. Interventions for promoting booster seat use in four to eight year olds traveling in motor vehicles. Cochrane Database of Systematic Reviews 2006, Issue 1. Art. No.: CD004334. DOI: 10.1002/14651858.CD004334.pub2.Further information for this Cochrane review is available in this issue of EBCH in the accompanying Expert Commentary and Characteristics and Key Findings Tables articles. Copyright © 2006 John Wiley & Sons, Ltd.
Commentary on ‘EMLA and Amethocaine for reduction of children's pain associated with needle insertion’
Authors: van Dijk Monique 
Published: September 2006

AbstractThis is a commentary on a Cochrane review, published in this issue of EBCH, first published as: Lander JA, Weltman BJ, So SS. EMLA and Amethocaine for reduction of children's pain associated with needle insertion. Cochrane Database of Systematic Reviews 2006, Issue 3. Art. No.: CD004236. DOI: 10.1002/14651858.CD004236.pub2.Further information for this Cochrane review is available in this issue of EBCH in the accompanying EBCH Summary and Characteristics and Key Findings Tables articles. Copyright © 2006 John Wiley & Sons, Ltd.
Characteristics and key findings for ‘Interventions for promoting booster seat use in four to eight year olds traveling in motor vehicles’
Authors: van Dalen Elvira , Offringa Martin , Kremer Leontien 
Published: September 2006

AbstractThese are the characteristics and key findings for a Cochrane review, published in this issue of EBCH, first published as: Ehiri JE, Ejere HOD, Magnussen L, Emusu D, King W, Osberg JS. Interventions for promoting booster seat use in four to eight year olds traveling in motor vehicles. Cochrane Database of Systematic Reviews 2006, Issue 1. Art. No.: CD004334. DOI: 10.1002/14651858.CD004334.pub2.Further information for this Cochrane review is available in this issue of EBCH in the accompanying EBCH Summary and Expert Commentary articles. Copyright © 2006 John Wiley & Sons, Ltd.
Informational intra‐group influence: the effects of time pressure and group size
Authors: Bonner Bryan L. , Baumann Michael R. 
Published: September 2006

AbstractThe judgments of groups have immense impact on our daily lives. This paper theorizes that three families of intra‐group influence affect the collective estimation process. These different forms of influence map to different levels of task demonstrability, or the extent to which correct answers are transparent to problem‐solvers. When demonstrability is low, group estimates are disproportionately influenced by proposals closer to the intra‐group mean (centrality). When demonstrability is high and groups are small, group decisions are disproportionately influenced by proposals closer to the correct answer (accuracy). Finally, when demonstrability is high and groups are larger, group decisions are disproportionately influenced by proposals offered by generally more accurate individuals across a set of judgments (expertise). Three laboratory studies support our predictions with regard to informational influence in cooperative groups. Copyright © 2006 John Wiley & Sons, Ltd.
Der Beitrag deutscher Botaniker an der Erforschung von Flora und Vegetation in der Mongolei
Authors: Hilbig Werner 
Published: September 2006

AbstractIn der Arbeit wird ein Überblick über die Forschungen deutscher Botaniker in der Mongolei gegeben. Beginnend mit Hinweisen auf deutsche Naturforscher in russischen Diensten im 18. und 19. Jahrhundert wird vor allem über die intensiven Forschungen während der letzten 40 Jahre und ihre Ergebnisse berichtet.Seit den 1960‐er Jahren führten vor allem Biologen der Akademie der Wissenschaften der DDR und der Martin‐Luther‐Universität Halle‐Wittenberg in Zusammenarbeit mit mongolischen Kollegen zahlreiche Untersuchungen in verschiedenen Teilen der Mongolei durch. Seit 1990 sind nunmehr Vertreter weiterer deutscher Universitäten an den Forschungen beteiligt. Die Forschungen auf Expeditionen und in Forschungsstationen führten zu internationalen Tagungen, zu zahlreichen Publikationen und zu Qualifizierungsarbeiten deutscher und mongolischer Expeditionsteilnehmer. Die vielen Publikationen werden zitiert.Die floristischen Untersuchungen erbrachten zahlreiche Neufunde von höheren Pflanzen, Moosen, Flechten und Pilzen sowie Neubeschreibungen von Arten. Am Institut für Biochemie der Pflanzen Halle der Akademie der Wissenschaften wurden viele Pflanzenarten chemisch analysiert. In den Herbarien der Universität Halle (HAL) und des Instituts für Pflanzengenetik und Kulturpflanzenforschung Gatersleben (GAT) wurden umfangreiche Mongolei‐Sammlungen aufgebaut.Die vegetationskundlichen und ökologischen Untersuchungen erbrachten detaillierte Vegetationsbeschreibungen von Teilgebieten der Mongolei und einen Überblick über die Vegetationseinheiten des Landes und ihre Standortsverhältnisse. Für die Naturschutzarbeit der Mongolei konnten Hinweise, speziell zur Schutzgebietsplanung, gegeben werden. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vegetationskundliche Untersuchungen in der Borzongijn‐ und Galbyn‐Gobi (Ömnögov Aimak, Mongolei)
Authors: Hilbig W. , Tungalag R. 
Published: September 2006

AbstractWährend der im August 2005 von Zoologen der Georg‐August‐Universität Göttingen durchgeführten 4. “Gobi Desert Vertebrates”‐Expedition in den Ömnögov Aimak der Mongolei, an der wir teilnehmen konnten, wurden von uns Vegetationsuntersuchungen in den pflanzengeographischen Bezirken Ost‐Gobi und Alašan‐Gobi durchgeführt. Dabei widmeten wir uns im Wesentlichen den weitverbreiteten zonalen Pflanzengesellschaften der Wüsten und Halbwüsten. Aber auch der Vegetation der grundwassernahen Standorte und der anthropogenen Vegetation wurde Beachtung geschenkt. Einige floristische Neunachweise für die genannten Bezirke konnten erbracht werden. Solanum physalifolium wurde in der Mongolei neu gefunden. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The identity of the three earliest binomials in BomareaMirb. (Alstroemeriaceae)
Authors: Hofreiter A. 
Published: September 2006

AbstractThe identity of the three Bomarea ‐species (B. multiflora, B. ovata and B. salsilla) used by Mirbel (1804) to set up the genus, is clarified. All synonyms and the variability and distribution of the species are discussed. The types are illustrated and epitype is chosen for B. salsilla. The type of B. ovata is identified. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel combination therapy against metastatic and androgen‐independent prostate cancer by using gefitinib, tamoxifen and etoposide
Authors: Mimeault Murielle , Venkatraman Ganesh , Johansson Sonny L. , Moore Erik , Henichart Jean‐Pierre , Depreux Patrick , Lin Ming‐Fong , Batra Surinder K. 
Published: September 2006

AbstractIn this study, we evaluated, for the first time, the antiproliferative and cytotoxic effects induced by a combination of a selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, gefitinib, with other chemotherapeutic drugs including estrogen receptor‐beta (ER‐β) antagonist (tamoxifen) and topoisomerase II inhibitor (etoposide) on some metastatic prostate cancer (PC) cell lines. Immunohistochemial analyses revealed that EGFR expression was enhanced in 38% of primary prostatic adenocarcinomas (Gleason scores 4–10) as compared to the corresponding normal tissues of the same prostate gland from 32 PC patients. The RT‐PCR and Western blot data have also indicated the higher expression levels of EGFR and ER‐β transcripts and proteins in metastatic LNCaP, DU145 and PC3 cells relative to nonmalignant normal prostate cells. Moreover, the results from MTT and FACS analyses revealed that the drugs, alone or in combination at lower concentrations, inhibited the growth of 17β‐estradiol (E2) plus EGF and serum‐stimulated androgen‐responsive LNCaP‐C33 and androgen‐independent LNCaP‐C81, DU145 and PC3 cells. Importantly, the combined gefitinib, tamoxifen and etoposide also caused a higher rate of apoptotic death of PC cells as compared to single agents. The cytotoxic effects induced by these drugs in PC3 cells appear to be mediated through the accumulation of cellular ceramide and activation of caspase cascades via a mitochondrial pathway. These findings indicate that the combined use of inhibitors of EGF‐EGFR and E2‐ER‐β signaling with etoposide, which act by increasing the cellular ceramide levels and caspase activity, represents a promising strategy for a more effective treatment of metastatic PC forms. © 2006 Wiley‐Liss, Inc.
Correlation between hypermethylation of the RASSF2A promoter and K‐ras/BRAF mutations in microsatellite‐stable colorectal cancers
Authors: Park Hye‐Won , Kang Hio Chung , Kim Il‐Jin , Jang Sang‐Geun , Kim Kun , Yoon Hyun‐Ju , Jeong Seung‐Yong , Park Jae‐Gahb 
Published: September 2006

AbstractRecently, RASSF2A was identified as a potential tumor suppressor epigenetically inactivated in human cancers. Here, we evaluated the methylation status of RASSF2A in colorectal cancer (CRC) and analyzed its correlation with K‐ras/BRAF mutations, microsatellite instability status and other clinicopathological features. Using methylation‐specific PCR and bisulfite sequencing, we analyzed the methylation status in primary CRC, adenomas and corresponding normal tissues and then compared it with the presence of K‐ras and BRAF mutations. We also examined the expression and methylation status of RASSF2A in CRC cell lines. We found that aberrant methylation of RASSF2A promoter regions is associated with gene silencing in CRC cell lines. In primary CRC, the frequency of RASSF2A methylation was 72.6%, and it was found in 16 of 16 (100%) adenomas. In addition, there was a positive correlation between K‐ras/BRAF mutations and RASSF2A methylation in primary CRC. Furthermore, a significant positive correlation between K‐ras/BRAF mutations and RASSF2A methylation was also observed in microsatellite‐stable (p = 0.033) and distal CRC (p = 0.025). These results show that RASSF2A methylation is a frequent event in colorectal tumorigenesis and positively correlates with K‐ras/BRAF mutation in microsatellite‐stable or distal CRC. © 2006 Wiley‐Liss, Inc.
Hypoxia leads to necrotic hepatocyte death
Authors: Smith Molly K. , Mooney David J. 
Published: September 2006

AbstractHepatocyte transplantation is being investigated as a therapy for liver disease; however, its success has been limited by rapid death of the cells following transplantation. This study was dedicated to elucidating the mode of death responsible for loss of transplanted hepatocytes in order to guide future strategies for promoting their survival. Using a tissue engineering model, it was found that the environment within polymer scaffolds containing transplanted cells was hypoxic after 5 daysin vivo, with (90 ± 3)% of hepatocytes existing at pO2< 10 mmHg. The primary mode of hepatocyte death in response to hypoxic conditions of 0 or 2 vol % oxygen was then determinedin vitro. Several assays for features of apoptosis and necrosis demonstrated that hepatocytes cultured in an anoxic environment died via necrosis, while culture at 2% oxygen inhibited proliferation. These results suggest it will not be possible to prevent hepatocyte death by interfering with the apoptotic process, and hypoxic conditions in the transplants must instead be addressed. The finding that the environment within cell transplantation scaffolds is hypoxic is likely applicable to many cell‐based therapies, and a similar analysis of the primary mode of death for other cell types in response to hypoxia may be valuable in guiding future strategies for their transplantation. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007