bluuebunny/crossref_metadata_2025_split huggingface dataset:
FGF alters epithelial competence for EGF at the initiation of branching morphogenesis of mouse submandibular gland
Authors: Nitta Mari , Kume Toshiaki , Nogawa Hiroyuki 
Published: November 2008

AbstractEmbryonic day 13 mouse submandibular gland (E13‐SMG) rudiments with two to four clefts have been commonly used in culture experiments to show that growth factors, such as epidermal growth factor (EGF) ‐family and fibroblast growth factor (FGF) ‐family ligands, are involved in branching morphogenesis. In the present study, we focused on E12 rudiments and attempted to elucidate the roles of EGF‐ and FGF‐family ligands in SMG development from E12 to E13. In mesenchyme‐free, Matrigel‐embedded cultures, EGF + lysophosphatidic acid (LPA) induced branching in E13 epithelium, whereas E12 epithelium remained spherical and no branching occurred under the same culture conditions; however, both E12 and E13 epithelia elongated in response to FGF10. Reverse transcriptase‐polymerase chain reaction studies showed that the expression of ErbB1 among four EGF receptors and Lpa3 among three LPA receptors was lower in E12 than in E13 epithelia. Fgf10, Fgf7, and their major receptor Fgfr2b were highly and equally expressed in E12 and E13 rudiments. After 24 hr of mesenchyme‐free culture with FGF10 or FGF7, E12 epithelium was primed to initiate branching morphogenesis in response to EGF + LPA coincident with ErbB1 and Lpa3 up‐regulation. These results suggest that the EGF‐family ligand–receptor system is undeveloped at E12 and that it becomes primed on E13 by the FGF ligand–receptor system to play an important role in the induction of branching morphogenesis. Developmental Dynamics 238:315–323, 2009. © 2008 Wiley‐Liss, Inc.
Effect of bone morphogenetic protein signaling on development of the jaw skeleton
Authors: Hu Diane , Colnot Celine , Marcucio Ralph S. 
Published: November 2008

AbstractBone morphogenetic proteins (BMPs) regulate many aspects of development including skeletogenesis. Here, we examined the response of neural crest‐derived cells to ectopic BMP signaling by infecting avian embryos with retroviruses encoding Bmp‐2 or Bmp‐4 at various times of development. Infection at stages 10 and 15 transformed large areas of the skull into cartilage by day 13. At this time cartilage condensations were still forming, which revealed the presence of uncommitted mesenchymal cells. By day 19, hypertrophic chondrocytes were present in the cartilage possibly due to changes in the perichondrium that relieved repression on hypertrophy. While these cells expressed Sox9, Collagen‐2, Runx2, Ihh, Noggin, and Collagen‐10, cartilage was not replaced by bone. Whether this is an intrinsic property of the skull cartilage, or results from sustained Bmp signaling is not known. Developmental Dynamics 237:3727–3737, 2008. © 2008 Wiley‐Liss, Inc.
To β or not to β: Canonical β‐catenin signaling pathway and ovarian development
Authors: Tevosian Sergei G. , Manuylov Nikolay L. 
Published: November 2008

AbstractThe mammalian embryonic gonad is a unique organ primordium in that it can adopt two different developmental fates—namely, differentiate as either a testis or an ovary—with dramatic consequences for an individual. While a molecular cascade culminating in testis development is well characterized, the ovarian pathways still remain enigmatic. The canonical Wnt/β‐catenin signaling implements a conserved mechanism of regulating gene expression that is integral to development of all metazoans. In this review, we summarize the recent evidence that suggests a central role for this signaling pathway in the development of the mammalian female. Developmental Dynamics 237:3672–3680, 2008. © 2008 Wiley‐Liss, Inc.
Semaphorin and neuropilin expression during early morphogenesis of Xenopus laevis
Authors: Koestner Ulrich , Shnitsar Iryna , Linnemannstöns Karen , Hufton Andrew L. , Borchers Annette 
Published: November 2008

AbstractSemaphorins are major regulators of morphogenesis and are involved in a variety of processes ranging from the guidance of cell migration to the development of cancer. Since semaphorins were first characterized as repulsive neuronal guidance cues, their expression has been best documented in the nervous system. However, broader studies are lacking. Here, we describe the expression of 13 members of the semaphorin family and two neuropilin receptors during early Xenopus laevis development. No particular expression pattern defines any of the semaphorin classes, but many are dynamically expressed in distinct areas undergoing morphogenetic cell movements like the developing mesoderm and the migrating neural crest. Furthermore, the complementary expression patterns of Sema3A/Nrp1 and Sema3F/Nrp2 are maintained across hundreds of millions of years, possibly indicating a conserved role in the guidance of migrating neural crest cells. Developmental Dynamics 237:3853–3863, 2008. © 2008 Wiley‐Liss, Inc.
Dnm3os, a non‐coding RNA, is required for normal growth and skeletal development in mice
Authors: Watanabe Tokumitsu , Sato Takahiro , Amano Tomokazu , Kawamura Yumiko , Kawamura Naohiro , Kawaguchi Hiroshi , Yamashita Naohide , Kurihara Hiroki , Nakaoka Takashi 
Published: November 2008

AbstractDnm3os, a gene that is transcribed into a non‐coding RNA (ncRNA), contains three micro RNAs (miRNAs), miR‐199a, miR‐199a*, and miR‐214, whose functions remain unknown in mammals. In this study, we introduced the lacZ gene into the Dnm3os locus to recapitulate its expression pattern and disrupt its function. Dnm3os+/lacZ heterozygous embryos showed β‐galactosidase activity, which reflected the authentic expression pattern of Dnm3os RNA. Most of the Dnm3oslacZ/lacZ homozygous pups died within one month of birth. After birth, Dnm3oslacZ/lacZ mice exhibited several skeletal abnormalities, including craniofacial hypoplasia, defects in dorsal neural arches and spinous processes of the vertebrae, and osteopenia. Importantly, the expression of miR‐199a, miR‐199a*, and miR‐214 was significantly down‐regulated in Dnm3oslacZ/lacZ embryos, supporting the assumption that Dnm3os serves as a precursor of these three miRNAs. Thus, Dnm3os has emerged as an miRNA‐encoding gene that is indispensable for normal skeletal development and body growth in mammals. Developmental Dynamics 237:3738–3748, 2008. © 2008 Wiley‐Liss, Inc.
Sandwich‐Type Heteroleptic opposite‐(Diazaporphyrinato)cerium Complexes: Synthesis, Spectroscopy, Structure, and Electrochemistry
Authors: Pan Na , Bian Yongzhong , Yokoyama Masaki , Li Renjie , Fukuda Takamitsu , Neya Saburo , Jiang Jianzhuang , Kobayashi Nagao 
Published: November 2008

AbstractTwo sandwich‐type heteroleptic tetrapyrrole cerium complexes, Ce2(dap)2(pc) (1) [dap = 2,8,12,18‐tetraethyl‐3,7‐13,17‐tetramethyl‐5,15‐diazaporphyrinate; pc = phthalocyaninate] and Ce(dap)(oep) (2) (oep = octaethylporphyrinate), were prepared by a one‐pot reaction of [Ce(acac)3]·nH2O (acac = acetylacetonate), metal‐free diazaporphyrin H2dap, and Li2pc or H2oep in refluxing 1,2,4‐trichlorobenzene. These sandwich double‐ and triple‐decker complexes were characterized by a wide range of spectroscopic methods in addition to elemental analysis. Their electrochemistry was also studied by cyclic voltammetry and differential pulse voltammetry. The molecular structure of Ce2(dap)2(pc) (1) was determined by X‐ray diffraction analysis, indicating an unexpected asymmetrical disposition of the ligands, with two adjacent dap moieties and one outer pc ring.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
[Ru(PPh3)3Cl2]‐Mediated Transformation of –CH3 into =CHPHPh3 in Biacetylmonoxime Acetyl‐/Aroylhydrazones: Ruthenium(III) Complexes with the Transformed Ligands
Authors: Raveendran Raji , Pal Samudranil 
Published: November 2008

AbstractRuthenium(III) complexes of general formula trans‐[Ru(tL)(PPh3)Cl2] have been isolated in 58–73 % yields from reactions between [Ru(PPh3)3Cl2] and tridentate Schiff bases (H2L) derived from biacetylmonoxime and acid hydrazides in methanol. The X‐ray structures of the complexes reveal unprecedented conversions of methyl groups in the biacetyl fragments of the Schiff bases into triphenyl‐vinyl‐λ5‐phosphane (=CHPHPh3) moieties in the transformed ligands (tL–). The metal centre in each complex is in a distorted octahedral N2OPCl2 coordination sphere made up of the meridionally spanning N,N,O‐donor tL–, PPh3 and two mutually trans‐oriented chlorides. In their electronic spectra, the complexes each display four absorptions due to ligand‐to‐metal and ligand‐centred transitions in the 463–260 nm range. All the complexes are one‐electron paramagnetic (μeff. at 298 K = 1.81–2.06 μB) and display rhombic EPR spectra in frozen (120 K) dichloromethane/toluene (1:1) solutions. Cyclic voltammograms of the complexes in dimethylformamide solutions show substituent‐sensitive, quasi‐reversible RuIV/RuIII and RuIII/RuII couples in the potential ranges of 0.46 to 0.54 V and –0.53 to –0.42 V (vs. Ag/AgCl), respectively.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Theoretical Description of Substituent Effects in Electrophilic Aromatic Substitution Reactions
Authors: Schwabe Tobias , Grimme Stefan 
Published: November 2008

AbstractThe ability of the current Kohn–Sham density functional theory (DFT) to compute the change of the proton affinity (PA) of phenol derivatives due to substitution is investigated. These systems can be used as models to predict reactivities in electrophilic aromatic substitution reactions. The complexity of the problem is increased systematically by introducing successively up to four substituents in five typical cases (methyl, cyano, fluorine, chlorine, and bromine). Our investigation can be regarded as representative for an important class of problems consistently encountered in the DFT modeling of organic reactions. High‐level theoretical reference data from CCSD(T) and SCS‐MP2 wave‐function calculations are presented, and the PAs are compared to those obtained by a series of density functionals (DFs). It is shown that not all DFs are capable of quantitatively reproducing the substituent effects. These can be simply linear in the number of substituents or show more complicated patterns. Especially for halogens, some DFs even fail completely. In these cases, linearly increasing errors with the number of groups are observed. Reliable results are obtained with hybrid DFs or the even more accurate double‐hybrid DF approach. The errors are attributed to the common self‐interaction (over‐delocalization) error in part of the DFs. Comparison with Hartree–Fock results shows that a reliable account of electron correlation is necessary to compute the PA of unsaturated and highly substituted molecules with chemical accuracy.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Synthesis of 1‐Amino‐1H‐indole‐3‐carboxylates by Copper(I)‐Catalyzed Intramolecular Amination of Aryl Bromides
Authors: Melkonyan Ferdinand , Topolyan Artyom , Yurovskaya Marina , Karchava Alexander 
Published: November 2008

AbstractA simple route to variousN‐substituted 1‐amino‐1H‐indole‐3‐carboxylates by use of copper(I)‐catalyzed intramolecularN‐arylation has been established. For the preparation ofN‐monosubstituted andN‐unsubstituted derivatives, the cyclization of Boc‐protected enehydrazines and subsequent deprotection were applied. Furthermore, 1‐alkoxyindole‐3‐carboxylates can be synthesized by use of the same protocol(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Are Ionic Liquids Suitable Media for Organocatalytic Reactions?
Authors: Toma Štefan , Mečiarová Mária , Šebesta Radovan 
Published: November 2008

AbstractRecent developments in organocatalysis have shown that these reactions can be advantageously performed in nonclassical media, such as ionic liquids or water. Among many organocatalysts, proline and its derivatives have attracted enormous attention, and these compounds have recently also been efficiently utilized in ionic liquids. Performing organocatalytic reactions in such media offer possibilities for easy catalyst recovery and reuse, on top of simplified product isolation.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis, Optical Resolution and Enantiomeric Recognition Ability of Novel, Inherently Chiral Calix[4]arenes: Trial Application to Asymmetric Reactions as Organocatalysts
Authors: Shirakawa Seiji , Moriyama Akihiro , Shimizu Shoichi 
Published: November 2008

AbstractNewly designed, inherently chiral calix[4]arenes containing amino phenol structures have been synthesized and resolved to optically pure forms. The enantiomeric recognition ability of one chiral calix[4]arene was examined with mandelic acid by 1H NMR spectroscopy, and we found that the inherently chiral calix[4]arene could be used as a chiral NMR solvating agent to determine the enantiopurity of mandelic acid at ambient temperature. In addition, the chiral calix[4]arenes were used as organocatalysts in asymmetric Michael‐type addition reactions of thiophenols, and high catalytic efficiency with low enantioselectivity was observed.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Kinetic Resolution of Racemic Carboxylic Acids Using Achiral Alcohols by the Promotion of Benzoic Anhydrides and Tetramisole Derivatives: Production of Chiral Nonsteroidal Anti‐Inflammatory Drugs and Their Esters
Authors: Shiina Isamu , Nakata Kenya , Onda Yu‐suke 
Published: November 2008

AbstractA variety of optically active carboxylic esters were produced by kinetic resolution of racemic carboxylic acids by using achiral alcohols, benzoic anhydrides, and Birman's tetramisole‐type catalysts. Bis(α‐naphthyl)methanol is a very effective reagent for producing the corresponding esters with high ee values in the presence of 4‐methoxybenzoic anhydride (PMBA) as the coupling reagent by promotion of benzotetramisole derivatives (BTM, α‐Np‐BTM, and β‐Np‐BTM). This protocol directly provides chiral carboxylic esters from free carboxylic acids and achiral alcohols by utilizing a transacylation process to generate the mixed anhydrides from the acid components with benzoic anhydride derivatives in the presence of chiral catalysts.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Protein extraction and 2‐DE of water‐ and lipid‐soluble proteins from bovine pericardium, a low‐cellularity tissue
Authors: Griffiths Leigh G. , Choe Leila , Lee Kelvin H. , Reardon Kenneth F. , Orton E. Christopher 
Published: November 2008

AbstractBovine pericardium (BP) is an important biomaterial used in the production of glutaraldehyde‐fixed heart valves and tissue‐engineering applications. The ability to perform proteomic analysis on BP is useful for a range of studies, including investigation of immune rejection after implantation. However, proteomic analysis of fibrous tissues such as BP is challenging due to their relative low‐cellularity and abundance of extracellular matrix. A variety of methods for tissue treatment, protein extraction, and ;fractionation were investigated with the aim of producing high‐quality 2‐DE gels for both water‐ and lipid‐soluble BP proteins. Extraction of water‐soluble proteins with 3‐(benzyldimethylammonio)‐propanesulfonate followed by n‐dodecyl β‐D‐maltoside extraction and ethanol precipitation for lipid‐soluble proteins provided the best combination of yield, spot number, and resolution on 2‐DE gels (Protocol E2). ESI‐quadrupole/ion trap or MALDI‐TOF/TOF MS protein identifications were performed to confirm bovine origin and appropriate subcellular prefractionation of resolved proteins. Twenty‐five unique, predominantly cytoplasmic bovine proteins were identified from the water‐soluble fraction. Thirty‐two unique, predominantly membrane bovine proteins were identified from the lipid‐soluble fraction. These results demonstrated that the final protocol produced high‐quality proteomic data from this important tissue for both cytoplasmic and membrane proteins.
Heat Effects of Dehydration of Human Serum Albumin in Hydrophilic Organic Solvents
Authors: Sirotkin V. A. , Sukhov A. V. , Dudkina E. V. 
Published: November 2008

AbstractA thermochemical model for describing the transfer of water from the protein phase to the organic solvent liquid phase and for determining how the solvation ability of organic solvents affects this process was developed. Enthalpy changes on the interaction of dried and hydrated human serum albumin (HSA) with hydrophilic organic solvents (dimethyl sulfoxide, formamide, ethanol, methanol and acetic acid) and water were measured by isothermal calorimetry at 25 °C. The initial hydration level of human serum albumin was varied in the entire water content range from 0–30 % [g water/g HSA]. The dependence of the interaction enthalpies on the initial water content is complex. The interaction enthalpies of the dried HSA with organic solvents are exothermic. At low water contents (less than 0.1 g/g), there is a sharp increase in the interaction enthalpy values. At the highest water contents (more than 0.2 g/g), the interaction enthalpies are endothermic for acetic acid and formamide and exothermic for DMSO, methanol, and ethanol. These thermochemical data were analyzed in conjunction with the results for the water adsorption in organic solvents to calculate the molar enthalpies of dehydration of HSA in organic liquids. It was found that the dehydration enthalpy changes may be endothermic or exothermic depending on the initial water content and the water solvation enthalpy value. From the results obtained, it can be concluded that: (i) only the solvation of water by hydrophilic organic solvent determines the changes in the dehydration enthalpy values, and (ii) the data for the enthalpies of solvation of water by the solvent at infinite dilution reflect this effect.
Accurate magnetic field evaluation due to underground power cables
Authors: Machado V. Maló , Almeida M. E. , Neves M. Guerreiro das 
Published: November 2008

AbstractExposure to low frequency magnetic fields has been a matter of health concern and controversy over the past years. These aspects motivated the development of methods and algorithms for the magnetic field evaluation due to power transmission lines and cables. In this paper special attention is given to buried power transmission cables. Results for different values of frequency and different values for the magnetic permeability of the soil are obtained, presented and compared with a standard approximation. Results confirm the importance of the method developed in this paper, not only as a reference method but also as a mandatory method for higher values of the soil magnetic permeability and higher values of the frequency. Copyright © 2008 John Wiley & Sons, Ltd.
Estimation of the critical clearing time using MLP and RBF neural networks
Authors: Karami Ali 
Published: November 2008

AbstractThis paper presents multi‐layer perceptron (MLP) and radial basis function (RBF) neural networks (NNs) based methods for the estimation of the critical clearing time (tcr) as an index for power systems transient stability analysis (TSA). The tcr evaluation involves elaborate computations that often include time‐consuming solutions of nonlinear on‐fault and post‐fault systems equations. Knowing that for a particular fault scenario (contingency), the tcr is a function of the pre‐fault system operating point, the objective of this paper is to show how one may develop the MLP and the RBF NNs based methods for estimating the tcr by using only the pre‐fault operating conditions as the inputs of the NNs. The paper uses the proposed MLP and RBF NNs based methods to estimate the tcr under different topological as well as operating conditions of the 10‐machane 39‐bus New England test power system, and results are given. The simulation results show that both NNs are able to retain past learned information almost instantaneously. However, compared to the RBF NN, the MLP NN makes us have a more accurate estimation for the tcr. Copyright © 2008 John Wiley & Sons, Ltd.
Some improvements on free surface simulation by the particle finite element method
Authors: Tang B. , Li J. F. , Wang T. S. 
Published: November 2008

AbstractThe Lagrangian method has become increasingly popular in numerical simulation of free surface problems. In this paper, after a brief review of a recent Lagrangian method, namely the particle finite element method, some issues are discussed and some improvements are made. The least‐square finite element method is adopted to simplify the solving of the Navier–Stokes equations. An adaptive time method is derived to obtain suitable time steps. A mass correction procedure is imported to improve the mass conservation in long time calculations and time discretization scheme is adopted to decrease the pressure oscillations during the calculations.Finally, the method is used to simulate a series of examples and the results are compared with the commercial FLOW3D code. Copyright © 2008 John Wiley & Sons, Ltd.
Implicit meanflow–multigrid algorithms for Reynolds stress model computation of 3‐D anisotropy‐driven and compressible flows
Authors: Gerolymos G. A. , Vallet I. 
Published: November 2008

AbstractThe present paper investigates the multigrid (MG) acceleration of compressible Reynolds‐averaged Navier–Stokes computations using Reynolds‐stress model 7‐equation turbulence closures, as well as lower‐level 2‐equation models. The basic single‐grid SG algorithm combines upwind‐biased discretization with a subiterative local‐dual‐time‐stepping time‐integration procedure. MG acceleration, using characteristic MG restriction and prolongation operators, is applied on meanflow variables only (MF–MG), turbulence variables being simply injected onto coarser grids. A previously developed non‐time‐consistent (for steady flows) full‐approximation‐multigrid (s–MG) is assessed for 3‐D anisotropy‐driven and/or separated flows, which are dominated by the convergence of turbulence variables. Even for these difficult test cases CPU‐speed‐ups rCPUSUP∈[3, 5] are obtained. Alternative, potentially time‐consistent approaches (unsteady u–MG), where MG acceleration is applied at each subiteration, are also examined, using different subiterative strategies, MG cycles, and turbulence models. For 2‐D shock wave/turbulent boundary layer interaction, the fastest s–MG approach, with a V(2, 0) sawtooth cycle, systematically yields CPU‐speed‐ups of 5±½, quasi‐independent of the particular turbulence closure used. Copyright © 2008 John Wiley & Sons, Ltd.
Simulation of a turbulent channel flow with an entropic Lattice Boltzmann method
Authors: Spasov M. , Rempfer D. , Mokhasi P. 
Published: November 2008

AbstractThe Lattice Boltzmann method (LBM) is used to simulate turbulent channel flow. Two simulations are performed. One uses high enough grid resolution in order for it to be considered a direct numerical simulation (DNS). LBM in its traditional form is adopted for this simulation. The other simulation uses lower resolution for which the original method becomes unstable. An entropy condition is used to render this simulation stable. Results from these two numerical experiments are compared with the results from a DNS performed with traditional numerical techniques. It is concluded that LBM can be used as tool to simulate turbulent flows and entropy stabilized LBM schemes can be used to achieve accurate results with reasonably low grid resolution. Copyright © 2008 John Wiley & Sons, Ltd.