bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nuclear β‐catenin promotes non‐neural ectoderm and posterior cell fates in amphioxus embryos
Authors: Holland Linda Z. , Panfilio Kristen A. , Chastain Roger , Schubert Michael , Holland Nicholas D. 
Published: June 2005

AbstractIn vertebrate development, Wnt/β‐catenin signaling has an early role in specification of dorsal/anterior identity and a late one in posterior specification. To understand the evolution of these roles, we cloned β‐catenin from the invertebrate chordate amphioxus. The exon/intron organization of β‐catenin is highly conserved between amphioxus and other animals including a cnidarian, but notDrosophila. In development, amphioxus β‐catenin is concentrated in all nuclei from the 16‐cell stage until the onset of gastrulation when it becomes undetectable in presumptive mesendoderm. Li+, which up‐regulates Wnt/β‐catenin signaling, had no detectable effect on axial patterning when applied before the late blastula stage, suggesting that a role for β‐catenin in specification of dorsal/anterior identity may be a vertebrate innovation. From the mid‐gastrula through the neurula stage, the highest levels of nuclear β‐catenin are around the blastopore. In the early neurula, β‐catenin is down‐regulated in the neural plate, but remains high in adjacent non‐neural ectoderm. Embryos treated with Li+at the late blastula stage are markedly posteriorized and lack a neural plate. These results suggest that in amphioxus, as in vertebrates, down‐regulation of Wnt/β‐catenin signaling in the neural plate is necessary for maintenance of the neuroectoderm and that a major evolutionarily conserved role of Wnt/β‐catenin signaling is to specify posterior identity and pattern the anterior/posterior axis. Developmental Dynamics 233:1430–1443, 2005. © 2005 Wiley‐Liss, Inc.
Identification of new netrin family members in zebrafish: Developmental expression of netrin2 and netrin4
Authors: Won Park Kye , Urness Lisa D. , Senchuk Megan M. , Colvin Carrie J. , Wythe Joshua D. , Chien Chi‐Bin , Li Dean Y. 
Published: June 2005

AbstractNetrin1 is a diffusible factor that attracts commissural axons to the floor plate of the spinal cord. Recent evidence indicates that Netrin1 is widely expressed and functions in the development of multiple organ systems. In mammals, there are three genes encoding Netrins, whereas in zebrafish, only the Netrin1 orthologs netrin1a and netrin1b have been identified. Here, we have cloned two new zebrafish Netrins, netrin2 and netrin4, and present a comparative sequence and expression analysis. Despite significant sequence similarity with netrin1a/netrin1b, netrin2 displays a unique expression pattern. Netrin2 transcript is first detected in the notochord and in developing somites at early somitogenesis. By late somitogenesis, netrin2 is expressed in the fourth rhombomere and is subsequently expressed in the hindbrain and otic vesicles. In contrast, netrin4 is detected only at very low levels during early development. The nonoverlapping expression patterns of these four Netrins suggest that they may play unique roles in zebrafish development. Developmental Dynamics 234:726–731, 2005. © 2005 Wiley‐Liss, Inc.
Platelet‐derived growth factors in the developing avian heart and maturating coronary vasculature
Authors: Van Den Akker Nynke M.S. , Lie‐Venema Heleen , Maas Saskia , Eralp Ismail , DeRuiter Marco C. , Poelmann Robert E. , Gittenberger‐De Groot Adriana C. 
Published: June 2005

AbstractPlatelet‐derived growth factors (PDGFs) are important in embryonic development. To elucidate their role in avian heart and coronary development, we investigated protein expression patterns of PDGF‐A, PDGF‐B, and the receptors PDGFR‐α and PDGFR‐β using immunohistochemistry on sections of pro‐epicardial quail–chicken chimeras of Hamburger and Hamilton (HH) 28–HH35. PDGF‐A and PDGFR‐α were expressed in the atrial septum, sinus venosus, and throughout the myocardium, with PDGFR‐α retreating to the trabeculae at later stages. Additionally, PDGF‐A and PDGFR‐α were present in outflow tract cushion mesenchyme and myocardium, respectively. Small cardiac nerves and (sub)epicardial cells expressed PDGF‐B and PDGFR‐β. Furthermore, endothelial cells expressed PDGF‐B, while vascular smooth muscle cells and interstitial epicardium‐derived cells expressed PDGFR‐β, indicating a role in coronary maturation. PDGF‐B is also present in ventricular septal development, in the absence of any PDGFR. Epicardium‐derived cells in the atrioventricular cushions expressed PDGFR‐β. We conclude that all four proteins are involved in myocardial development, whereas PDGF‐B and PDGFR‐β are specifically important in coronary maturation. Developmental Dynamics 233:1579–1588, 2005. © 2005 Wiley‐Liss, Inc.
Wideband multi‐beam forming method using delayed array sensors and two‐dimensional digital filter
Authors: Nishikawa Kiyoshi 
Published: June 2005

AbstractIn this paper, a method is proposed for multi‐beam forming of wideband signals by means of delay processors and two‐dimensional fan filters. Only one axially symmetric two‐dimensional fan filter is used. Multi‐beam forming is carried out by multiplexing the delay processors for two‐dimensional signals for each beam direction. The delay processing here corresponds to a rotation of the two‐dimensional spectra in the two‐dimensional frequency domain and provides a delay proportional to the sensor location to each sensor output. Since each delay is a fractional delay, a method of digital signal processing based on high‐speed sampling and thinning is used for realization. A design method for multi‐beam forming is given and a study of expanding the receiving angle range is carried out. It is shown that excellent multi‐beam forming is possible if the method is used within an appropriate receiving signal range, although the beam width is slightly different depending on the beam direction. Finally, a difference of the method from multi‐beam forming by the use of several two‐dimensional fan filters is discussed. The positioning of this method and its effectiveness are clarified. © 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 88(12): 1–12, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20175
Luminescence and Theoretical Studies of Cu(tripod)X [tripod = 1,1,1‐Tris(diphenylphosphanylmethyl)ethane; X– = Halide, Thiophenolate, Phenylacetylide]
Authors: Pawlowski Valeri , Knör Günther , Lennartz Christian , Vogler Arnd 
Published: June 2005

AbstractComplexes of the type CuI(tripod)X [tripod = 1,1,1‐tris(diphenylphosphanylmethyl)ethane; X– = Br–, I–, PhS–, PhC≡C–]are phosphorescent in solution and in the solid state (λmax ≈ 465 nm). Calculations show that the emissive triplet is of mixed MLCT/LLCT character. The emission is facilitated by the rigid tetrahedral structure, which is imposed by the tripod ligand. Accordingly, a distortion towards a square‐planar geometry, which should occur upon MLCT excitation, is prevented. On the other hand, in the triplet state the phenyl substituents of the phosphane ligands undergo a rotation which favours radiationless deactivation. As a result, the emission efficiency is relatively small in solution, but much higher in the solid state owing to the rigidity of the lattice. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Silanes/Oxygen/(Water): Green High‐Energy‐Density Materials
Authors: Hong Ding Yi , Inagaki Satoshi 
Published: June 2005

AbstractDesign of green high‐energy‐density materials as powerful as the well‐known H2/O2 and N2H4/O2 systems is a never‐ending goal. Here, we study the energetic properties of reactions of silanes with oxygen (and gaseous water) by the bond energy procedure and high‐level quantum chemistry calculations. The silanes/oxygen/(water) reactions finally lead to the green products, namely silica and water or silicic acids that exist in nature. The energy densities of these systems with respect to silica and water are higher than those of the conventional H2/O2 and N2H4/O2 systems. Their energy densities with respect to silicic acids are also higher than or comparable to that of the N2H4/O2 system. We propose that silanes/oxygen/(water) could be powerful green high‐energy‐density materials. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis, Crystal Structure and Characterisation of a Novel Chiral Mixed‐Valence Vanadium Oxide Hybrid, [V5O11(dien)3]
Authors: Fu Ming‐Lai , Guo Guo‐Cong , Wu A‐Qing , Liu Bin , Cai Li‐Zhen , Huang Jin‐Shun 
Published: June 2005

AbstractThe novel chiral mixed‐valence vanadium oxide hybrid [V5O11(dien)3] (1) (dien = NH2C2H4NHC2H4NH2) has been synthesised by a hydrothermal reaction of V2O5 and dien in aqueous solution and characterised by elemental analysis, IR spectroscopy, TG‐DSC analysis, magnetism, EPR spectroscopy, single‐crystal X‐ray diffraction and powder XRD. The X‐ray diffraction analysis revealed that the structure of 1 can be regarded as being constructed from two [VVO4]3– groups bicapping three [VIVO(dien)]2+ units to form a discrete asymmetric pentanuclear vanadium complex with the dien ligands coordinating directly to the vanadium(IV) centres. Compound 1 exhibits an interesting tube‐like 3D supramolecular structure due to abundant hydrogen‐bonding interactions between the oxygen atoms of the inorganic backbone and the hydrogen atoms of the dien ligands from adjacent molecules. The variable‐temperature magnetic susceptibility data of 1 suggest a weak ferromagnetic interaction among V4+ ions in the cluster. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A Straightforward Route to Copper/Zinc Oxide Nanocomposites: The Controlled Thermolysis of Zn[Cu(CN)3]
Authors: Guo Yanzhi , Weiss Rainer , Epple Matthias 
Published: June 2005

AbstractCopper–zinc nanocomposites were prepared by thermolysis of copper–zinc cyanides under mild conditions. Two different routes were used for the preparation of the cyanide complex: A batch precipitation method and the continuous overflow precipitation method. The thermolysis of the cyanides was studied in‐situ by thermogravimetry coupled with infrared spectroscopy (TG‐IR) and by thermogravimetry coupled with mass spectroscopy (TG‐MS). The structure of the nanocomposites was investigated by X‐ray powder diffraction (XRD) and extended X‐ray absorption fine structure (EXAFS). Geometric models were suggested on the atomic scale based on EXAFS results for the precursor, the mixed oxides (CuO/ZnO), and the reduced copper–zinc samples (Cu/ZnO, i. e. catalyst for methanol synthesis). In the batch precipitation method, the influence of temperature on the morphology of the thermolysis products was explored. In the continuous overflow method, the morphology of the Cu–Zn cyanide complex was investigated as a function of concentration and residence time. A high solution concentration and a short residence time (equivalent to a high flow rate) led to smaller particles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Synthesis and Characterization of Heterotrinuclear Complexes of Nickel and Palladium with Pyridinecarboxylate as Bridging Ligands
Authors: Ruiz José , Santana María Dolores , Lozano Abel , Vicente Consuelo , García Gabriel , López Gregorio , Pérez José , García Luis 
Published: June 2005

AbstractHeterotrinuclear pyridinecarboxylate complexes of nickel(II) and palladium(II) of the types [Ni(mcN3)(pyridinecarboxylate)]2{μ‐[Pd(C6F5)2]}(PF6)2 [mcN3 = 2,4,4‐trimethyl‐1,5,9‐triazacyclododec‐1‐ene (Me3‐mcN3) or 2,4,4,9‐tetramethyl‐1,5,9‐triazacyclododec‐1‐ene (Me4‐mcN3)] have been prepared by two different routes. The corresponding monomeric pyridinecarboxylate complexes of nickel and the monomeric pyridinecarboxylic acid/ester complexes of palladium have also been prepared. The crystal structures of two precursors [Ni(Me4‐mcN3)(NC5H4‐3‐COO)]PF6 and cis‐[Pd(C6F5)2(NC5H4‐4‐CH2COOCH3)2] have been established by X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Heparin structures in FGF‐2–dependent morphological transformation of astrocytes
Authors: Nagayasu Toshie , Miyata Seiji , Hayashi Noriko , Takano Ryo , Kariya Yutaka , Kamei Kaeko 
Published: June 2005

AbstractFibroblast growth factor‐2 (FGF‐2) participates in the morphological transformation of astrocytes (stellation) during the formation of glial scars in injured brains. In the current study, we used quantitative morphometric analysis to investigate the structural requirements for heparin's enhancement of FGF‐2‐induced stellation of cultured cortical astrocytes. Native heparin significantly promoted FGF‐2‐dependent astrocytic stellation, whereas heparin hexasaccharide inhibited FGF‐2‐dependent stellation. Furthermore, 2‐O‐, 6‐O‐, and N‐desulfated heparins were unable to promote FGF‐2‐dependent stellation. The stellation induced by FGF‐2 or by a combination of FGF‐2 and native heparin was inhibited by SU5402, an FGF receptor inhibitor. These results demonstrate that the length and sulfated position of heparin are important for its enhancement of FGF‐2‐dependent astrocyte stellation. In addition, our findings show that heparin oligosaccharides are useful for regulating the FGF‐2‐dependent astrocytic transformation. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Simple and accurate fracture toughness testing methods for pyrolytic carbon/graphite composites used in heart‐valve prostheses
Authors: Kruzic J. J. , Kuskowski S. J. , Ritchie R. O. 
Published: June 2005

AbstractThe fracture toughness is a critical material property for the pyrolytic carbon materials used in mechanical heart‐valve prostheses; however, making accurate toughness measurements has traditionally been problematic due to difficulties in fatigue precracking specimens. In this work, a simple, effective, and reliable precracking method is presented where a sharp precrack is “popped in” from a razor micronotch, which allows significant savings of time and materials relative to fatigue precracking methods. It is further shown that equivalent results may be obtained using razor micronotched specimens directly without precracking, provided the notch is sufficiently sharp. Indeed, mean toughness values of 1.46 ± 0.13 and 1.35 ± 0.09 MPa√m were obtained for the pyrolytic carbon‐coated graphite materials, using precracked and razor micronotched specimens, respectively. The difference between these mean values proved to be statistically insignificant, and these values are in general agreement with published fracture toughness results obtained using fatigue precracked specimens. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2005
Effect of hybrid layer on stress distribution in a premolar tooth restored with composite or ceramic inlay: An FEM study
Authors: Belli Sema , Eskitaşcioǧlu Gürcan , Eraslan Oǧuz , Senawongse Pisol , Tagami Junji 
Published: June 2005

AbstractThe aim of this finite elemental stress analysis study was to evaluate the effect of hybrid layer on distribution and amount of stress formed under occlusal loading in a premolar tooth restored with composite or ceramic inlay. The mandibular premolar tooth was selected as the model based on the anatomical measurements suggested by Wheeler. The analysis is performed by using a Pentium II IBM compatible computer with the SAP 2000 structural analysis program. Four different mathematical models including the following structures were evaluated: 1) composite inlay, adhesive resin, and tooth structure; 2) composite inlay, adhesive resin, hybrid layer, and tooth structure; 3) ceramic inlay, adhesive resin, and tooth structure; 4) ceramic inlay, adhesive resin, hybrid layer, and tooth structure. Loading was applied from the occlusal surface of the restoration, and shear stresses under loading were evaluated. The findings were drawn by the Saplot program, and the results were analyzed by graphical comparison method. The output indicated that the hybrid layer acts as a stress absorber in models 2 and 4. The hybrid layer has also changed mathematical values of stress on cavity floors in both restoration types. Ceramic inlay collected the stress inside the body of the material, but the composite inlay directly transferred the stress through dental tissues. As a result, it was concluded that the hybrid layer has an effect on stress distribution under loading in a premolar tooth model restored with composite or ceramic inlay. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Permeability of adhesive resin films
Authors: Hashimoto Masanori , Tay Franklin R. , Ito Shuichi , Sano Hidehiko , Kaga Masayuki , Pashley David H. 
Published: June 2005

AbstractThe purpose of this study was to quantify the permeability of adhesive resin films to water by measuring convective flow across thin films. Cured resin films were prepared with the use of five commercially available adhesive resins and an experimental resin. Two types of resin films were prepared from solvated comonomer blends within each product; resin films made before or after evaporation of solvent (10 s of drying with air‐syringe). The permeability of the resin films was measured 30 min or 24 h after polymerization by placing the films in a split‐chamber device. Fluid filtration rate through the resin films was measured with the use of 20 cm of water pressure. Osmotically induced water movement was measured by applying hypertonic aqueous solutions of CaCl2 or HEMA to the resin films. The results showed that evaporation of solvent before polymerization reduced the permeability of adhesive resin films, compared to permeabilities obtained without solvent evaporation. The cured adhesive resin films were all permeable to water, but to varying degrees. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2005
Genome size and endonuclear DNA replication in spiders
Authors: Rasch Ellen M. , Connelly Barbara A. 
Published: June 2005

AbstractAlthough genome sizes (C‐values) are now available for 115 arachnid species (Gregory and Shorthouse [2003] J Hered 94:285–290), the extent of genome amplification (endonuclear DNA replication or polyploidization) accompanying tissue differentiation in this diverse and abundant class of invertebrates remains unknown. To explore this aspect of arachnid development, samples of hemolymph and other tissues were taken from wild‐caught specimens as air‐dried smears, stained with the Feulgen reaction for DNA, and assayed using both scanning and image analysis densitometry. Cells from midgut diverticula and Malpighian tubules of Argiope and Lycosa (=Pardosa) often showed giant nuclei with 50–100 pg of DNA per nucleus, reflecting at least four cycles of endonuclear DNA replication when compared to the DNA content of hemocytes or sperm from the same specimen. Nuclei with markedly elevated DNA levels also appeared, but far less frequently, in tissue samples from several other arachnid species (Antrodiaetus, Hypochilus, Latrodectus, Liphistus and Loxosceles), but revealed no correlation with differences in somatic cell (2C) genome sizes. Our data show that several DNA classes of polysomatic nuclei regularly arise during tissue differentiation in some species of spiders and may provide an interesting model system for further study of patterns of tissue‐specific variation in DNA endoreduplication during development. J. Morphol. © 2005 Wiley‐Liss, Inc.
Isomerization of the protonated acetone dimer in the gas phase
Authors: Norrman K. , Sølling T. I. , McMahon T. B. 
Published: June 2005

AbstractMass spectrometry‐based methods have been employed in order to study the reactions of non‐ (h6/h6), half (d6/h6), and fully (d6/d6) deuterium labeled protonated dimers of acetone in the gas phase. Neither kinetic nor thermodynamic isotope effects were found. From MIKES experiments (both spontaneous and collision‐induced dissociations), it was found that the relative ion yield (m/z 65 vs m/z 59) from the dissociation reaction of half deuterium labeled (d6/h6) protonated dimer of acetone is dependent on the internal energy. A relative ion yield (m/z 65 vs m/z 59) close to unity is observed for cold, nonactivated, metastable ions, whereas the ion yield is observed to increase (favoring m/z 65) when the pressure of the collision gas is increased. This is in striking contrast to what would be expected if a kinetic isotope effect were present. A combined study of the kinetics and the thermodynamics of the association reaction between acetone and protonated acetone implicates the presence of at least two isomeric adducts. We have employed G3(MP2) theory to map the potential energy surface leading from the reactants, acetone and protonated acetone, to the various isomeric adducts. The proton‐bound dimer of acetone was found to be the lowest‐energy isomer, and protonated diacetone alcohol the next lowest‐energy isomer. Protonated diacetone alcohol, even though it is an isomer hidden behind many barriers, can possibly account for the observed relative ion yield and its dependence on the mode of activation. Copyright © 2005 John Wiley & Sons, Ltd.
MALDI‐TOF mass spectrometric analysis for the characterization of the 5,10,15,20‐tetrakis‐ (m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) photoproducts in biological environment
Authors: Lassalle Henri‐Pierre , Lourette Natacha , Maunit Benoît , Muller Jean‐François , Guillemin François , Bezdetnaya‐Bolotine Lina 
Published: June 2005

AbstractPhotoproducts formation upon irradiation (739 nm) of 5,10,15,20‐tetrakis(m‐hydroxyphenyl)bacteriochlorin (m‐THPBC) in phosphate buffer saline (PBS) supplemented with human serum albumin (HSA) were studied by means of absorption spectroscopy and MALDI‐TOF mass spectrometry. The experiments were performed with a freshly prepared PBS–HSA solution of m‐THPBC and with a PBS–HSA m‐THPBC solution incubated for 6 h at 37 °C. The incubation of m‐THPBC solution leads to the dye monomerisation, whereas in the freshly prepared solution, m‐THPBC is under an aggregated form. Regardless of the incubation condition, photobleaching experiments carried out by absorption spectroscopy demonstrate the degradation of the photosensitizer and its phototransformation in m‐THPC. Moreover, m‐THPC was the sole photoproduct detected using absorption spectroscopy. Together with a degradation of m‐THPBC and formation of m‐THPC, MALDI‐TOF mass spectrometry evidenced several other photoinduced modifications. Photoproducts such as dihydroxy m‐THPBC and dihydroxy m‐THPC were detected in both conditions; however, the formation of hydroxylated photoproducts was significantly greater in incubated solution. In addition, small molecules arising from the degradation of the photosensitizer and identified as dipyrin derivatives and dipyrrolic synthon were observed. Copyright © 2005 John Wiley & Sons, Ltd.