bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization and multilineage differentiation of embryonic stem cells derived from a buffalo parthenogenetic embryo
Authors: Sritanaudomchai Hathaitip , Pavasuthipaisit Kanok , Kitiyanant Yindee , Kupradinun Piengchai , Mitalipov Shoukhrat , Kusamran Thanit 
Published: February 2007

AbstractEmbryonic stem (ES) cells derived from mammalian embryos have the ability to form any terminally differentiated cell of the body. We herein describe production of parthenogenetic buffalo (Bubalus Bubalis) blastocysts and subsequent isolation of an ES cell line. Established parthenogenetic ES (PGES) cells exhibited diploid karyotype and high telomerase activity. PGES cells showed remarkable long‐term proliferative capacity providing the possibility for unlimited expansion in culture. Furthermore, these cells expressed key ES cell‐specific markers defined for primate species including stage‐specific embryonic antigen‐4 (SSEA‐4), tumor rejection antigen‐1‐81 (TRA‐1‐81), and octamer‐binding transcription factor 4 (Oct‐4). In vitro, in the absence of a feeder layer, cells readily formed embryoid bodies (EBs). When cultured for an extended period of time, EBs spontaneously differentiated into derivatives of three embryonic germ layers as detected by PCR for ectodermal (nestin, oligodendrocytes, and tubulin), mesodermal (scleraxis, α‐skeletal actin, collagen II, and osteocalcin) and endodermal markers (insulin and α‐fetoprotein). Differentiation of PGES cells toward chondrocyte lineage was directed by supplementing serum‐containing media with ascorbic acid, β‐glycerophosphate, and dexamethasone. Moreover, when PGES cells were injected into nude mice, teratomas with derivatives representing all three embryonic germ layers were produced. Our results suggest that the cell line isolated from a parthenogenetic blastocyst holds properties of ES cells, and can be used as an in vitro model to study the effects of imprinting on cell differentiation and as an a invaluable material for extensive molecular studies on imprinted genes. Mol. Reprod. Dev. 74: 1295–1302, 2007. © 2007 Wiley‐Liss, Inc.
Dynamics of lamin A/C in porcine embryos produced by nuclear transfer
Authors: Lee Kiho , Fodor William L. , Machaty Zoltan 
Published: February 2007

AbstractThis study was conducted to investigate the presence of lamin A/C in porcine nuclear transfer embryos and to determine whether lamin A/C can serve as a potential marker for nuclear reprogramming. First, lamin A/C was studied in oocytes and embryos produced by fertilization or parthenogenetic oocyte activation. We found that lamin A/C was present in the nuclear lamina of oocytes at the germinal vesicle stage while it was absent in mature oocytes. Lamin A/C was detected throughout preimplantation development in both in vivo‐derived and parthenogenetic embryos. Incubation of the activated oocytes in the presence of α‐amanitin (an inhibitor of RNA polymerase II), or cycloheximide (a protein synthesis inhibitor) did not perturb lamin A/C assembly, indicating that the assembly resulted from solubilized lamins dispersed in the cytoplasm. In nuclear transfer embryos, the lamin A/C signal that had previously been identified in fibroblast nuclei disappeared soon after fusion. It became detectable again after the formation of the pronucleus‐like structure, and all nuclear transfer embryos displayed lamin A/C staining during early development. Olfactory bulb progenitor cells lacked lamin A/C; however, when such cells were fused with enucleated oocytes, the newly formed nuclear envelopes stained positive for lamin A/C. These findings suggest that recipient oocytes remodel the donor nuclei using type A lamins dispersed in the ooplasm. The results also indicate that lamin A/C is present in the nuclear envelope of pig oocytes and early embryos and unlike in some other species, its presence after nuclear transfer is not an indicator of erroneous reprogramming. Mol. Reprod. Dev. 74: 1221–1227, 2007. © 2007 Wiley‐Liss, Inc.
Design and Implementation of a Novel Quench Flow Reactor for the Study of Nascent Olefin Polymerisation
Authors: Di Martino Audrey , Broyer Jean‐Pierre , Schweich Daniel , de Bellefon Claude , Weickert Guenter , McKenna Timothy F. L. 
Published: February 2007

AbstractA novel stopped flow reactor system is described in the current work, along with the underlying design philosophy. While the concept of stopped flow technology is not recent, this system is the first to be designed with the objective of studying particle morphology, and to work at extremely short (40 ms) residence times. It is shown that traditional chemical engineering principles are required to properly design and operate this type of reactor, and that when correctly design, it is a very flexible tool for the study of nascent polymerisation of olefins.magnified image
Vibration of axisymmetric composite piezoelectric shells coupled with internal fluid
Authors: Larbi W. , Deü J.‐F. , Ohayon R. 
Published: February 2007

AbstractThis paper presents the theoretical and finite element formulations of piezoelectric composite shells of revolution filled with compressible fluid. The originality of this work lies (i) in the development of a variational formulation for the fully coupled fluid/piezoelectric structure system, and (ii) in the finite element implementation of an inexpensive and accurate axisymmetric adaptive laminated conical shell element. Various modal results are presented in order to validate and illustrate the efficiency of the proposed fluid–structure finite element formulation. Copyright © 2007 John Wiley & Sons, Ltd.
External quality assessment of rapid prenatal detection of numerical chromosomal aberrations using molecular genetic techniques: 3 years experience
Authors: Ramsden S. C. , Mann K. , McConnell C. , Hastings R. 
Published: February 2007

AbstractObjectivesPrenatal diagnosis using rapid molecular genetic techniques is now a widely used method for detecting the most prevalent chromosomal aneuploidies. The object of this work was to develop a methodology for delivering external quality assessment (EQA) appropriate to the needs of routine diagnostic testing laboratories.MethodsWe have provided three rounds of EQA using 15 different samples over 3 years. The scheme has developed to assess both the genotyping accuracy of the results and the appropriateness of the clinical reports issued to the referring clinician.ResultsParticipation in the EQA scheme has increased from 9 to 27 laboratories from across Europe over the three sample distributions. All laboratories have used quantitative fluorescence‐PCR (QF‐PCR) to analyse these samples except for a sole participant in 2006 who used multiplex ligation‐dependent probe amplification (MLPA). In total 265 samples have been distributed, of which four (1.5%) were not reported due to technical failures and one (0.4%) was reported incorrectly and must be regarded as a genotyping error.ConclusionsWe have demonstrated a significant and increasing demand for EQA in the rapid detection of aneuploidies in UK and other European laboratories. Using the methodologies described, we have had a very low rate of technical failures and demonstrated a high level of genotyping accuracy. However, the quality of the clinical reports was variable and suggestions are made for improvement. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of molecular weight on shape memory behavior in polyurethane films
Authors: Chen Shaojun , Hu Jinlian , Liu Yeqiu , Liem Haiming , Zhu Yong , Meng Qinghao 
Published: February 2007

AbstractUnderstanding the relationship between the number‐average molecular weight (Mn) and the shape memory behavior of polymers is crucial for a complete picture of their thermomechanical properties, and hence for the development of smart materials, and, in particular, in textile technology. We report here on the study of shape memory properties as a function of Mn of polymers. Shape memory polyurethanes (SMPUs) of different Mn were synthesized, with various catalyst contents or molar ratio(r = NCO/OH) in the composition. In particular, two types of SMPU, namely Tm and Tg types according to their switch temperature type, were synthesized to compare the influence of Mn on their shape memory behavior. X‐ray diffraction, differential scanning calorimetry, dynamic mechanical analysis, and shape memory behavior results for the SMPUs are presented. The results indicate that the melting temperature (Tm), the glass transition temperature (Tg), the crystallinity, and the crystallizability of the soft segment in SMPUs are influenced significantly by Mn, before reaching a critical limit around 200 000 g mol−1. Characterization of the shape memory effect in PU films suggests that the Tm‐type films generally show higher shape fixities than the Tg‐type films. In addition, this shape fixity decreases with increasing Mn in the Tg‐type SMPU, but the shape recovery increases with Mn in both types of SMPU. The shape recovery temperature, in contrast, decreases with Mn as suggested by the result of their thermal strain recovery. It is concluded that a higher molecular weight (Mn > 200 000 g mol−1) is a prerequisite for SMPUs to exhibit higher shape recovery at a particular temperature. Copyright © 2007 Society of Chemical Industry
SNi fragmentations of alkoxychlorocarbenes – a perspective
Authors: Moss Robert A. , Fu Xiaolin , Sauers Ronald R. 
Published: February 2007

AbstractAfter a review of the early literature concerning SNi fragmentations of alkyl chlorosulfites and chloroformates, we present experimental and computational results for the SNi fragmentations of alkoxychlorocarbenes. Examples include cyclohexyloxychlorocarbene, 7‐norbornyloxychlorocarbene, 3‐nortricyclyloxychlorocarbene, exo‐5‐norbornenyl‐2‐oxychlorocarbene, and endo‐5‐norbornenyl‐2‐oxychlorocarbene. Computations generate a ‘family’ of closely related charge‐separated SNi structures which approximate asynchronous, polar, concerted transition states and tight, short‐lived ion pair intermediates. The precise description and behavior of these species in a given reaction depends on the identities of the alkyl group, the potential counterion, and the solvent. Copyright © 2007 John Wiley & Sons, Ltd.
Assessing the transport properties of organic penetrants in low‐density polyethylene using free volume models
Authors: Ritums J. E. , Neway B. , Doghieri F. , Bergman G. , Gedde U. W. , Hedenqvist M. S. 
Published: February 2007

AbstractThree models, two of them relying on free volume—the Cohen–Turnbull–Fujita (CTF) model and the Vrentas–Duda (VD) model, and the third being empirical using an exponential concentration dependence of the diffusivity, were applied to desorption data for a series of alkane penetrants (2,2‐dimethylbutane, cyclohexane, n‐hexane, n‐decane, and n‐tetradecane) in low‐density polyethylene. The CTF model described the desorption data very well and better than the exponential diffusion law. The VD model with the attractive feature of being based on independently determined parameters was unsuccessful in describing the desorption data. Diffusivity data indicated that the three components outside the crystal core were less accessible to n‐tetradecane than to the other penetrants. This indication was further substantiated by solubility data. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 723–734, 2007
Electrical conductivity and polarization processes in nanocomposites based on isotactic polypropylene and modified synthetic clay
Authors: Motori Antonio , Montanari Gian Carlo , Saccani Andrea , Patuelli Francesca 
Published: February 2007

AbstractThe direct‐current and alternating‐current electrical behavior of nanocomposites, formed by isotactic polypropylene partially modified with maleic anhydride and filled with different amounts of modified synthetic clay, has been studied; moreover, the conduction mechanisms and the relaxation processes that take place in the materials have been investigated. The nanocomposites containing small clay contents exhibit direct‐current insulating properties comparable to or even higher than those observed in the polymeric matrix. However, as the synthetic clay content increases, the ionic contribution to conductivity becomes considerable. The nanocomposites also show a slightly higher permittivity and loss factor than the host material because of the appearance of a thermally activated relaxation process in the frequency range of 10−2 to 102 Hz at the investigated temperatures. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 705–713, 2007
Absence of epidermal growth factor receptor gene mutations in patients with hormone refractory prostate cancer not responding to gefitinib
Authors: Curigliano Giuseppe , Pelosi Giuseppe , De Pas Tommaso , Renne Giuseppe , De Cobelli Ottavio , Manzotti Michela , Spitaleri Gianluca , de Braud Filippo 
Published: February 2007

AbstractBACKGROUNDMutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene in human cancers are associated with increased sensitivity to anilinoquinazoline EGFR inhibitors. To our knowledge no data have been reported on EGFR gene mutations in hormone refractory prostate cancer (HRPC).METHODSBetween March 2003 and December 2004, 23 patients with HRPC received 250 mg oral gefitinib daily in addition to antiandrogen plus luteinizing hormone‐releasing hormone (LH‐RH) analog for at least 2 months or until disease progression. Patients with unresected prostate cancer prospectively underwent trans‐rectal biopsy of primary tumor (before starting gefitinib treatment).RESULTSNone of the patients demonstrated PSA or objective response to gefitinib. We sequenced exons 18–21 of the EGFR TK domain from genomic DNA isolated from 8 HRPC patients. No patient showed EGFR TK domain mutations.CONCLUSIONSOur results show EGFR mutations did not occur in these patients suggesting that gefitinib is unlikely to be effective in patients with tumors not harboring specific EGFR TK domain. Prostate 67: 603–604, 2007. © 2007 Wiley‐Liss, Inc.
Fusion characteristics of rigid PVC/wood‐flour composites by torque rheometry
Authors: Matuana Laurent M. , Kim Jae‐Woo 
Published: February 2007

AbstractThis study was aimed at examining the effects of wood flour contents, wood species (softwood vs. hardwood), and particle size on the fusion characteristics (fusion time, fusion temperature, fusion torque, and fusion energy) of rigid PVC/wood‐flour composites in a torque rheometer. Neat rigid PVC exhibited one fusion peak, whereas the addition of wood flour into the PVC matrix led to two fusion peaks. Increased wood flour content caused a significant increase in the time, temperature, and energy at which fusion between the primary particles started, thereby leading to increased fusion torque, irrespective of the wood flour species. These results implied that rigid PVC filled with wood flour must be processed at higher temperatures than neat resin. Although fusion characteristics of the composites were influenced by the wood species, a clear trend between softwood and hardwood species could not be established. However, finer particles fused more quickly and needed less energy than coarse ones. J. VINYL ADDIT. TECHNOL., 13:7–13, 2007. © 2007 Society of Plastics Engineers.
Ultrasound‐aided extrusion process for preparation of polypropylene–clay nanocomposites
Authors: Lapshin Sergey , Isayev A. I. 
Published: February 2007

AbstractTwo methods for the fabrication of polypropylene/clay nanocomposites using a continuous ultrasound assisted process are compared. In the first approach, a two‐stage process was implemented. The nanocomposites were prepared by using a corotating twin‐screw extruder followed by a single‐screw extruder equipped with an ultrasonic die attachment. In the second method, a single‐stage process was used. The nanocomposites were compounded by using a single‐screw extruder with mixing elements and an ultrasonic die attachment. Two regimens of feeding were realized, namely, starved and flood feeding. The gap size in the ultrasonic treatment zone was varied. Die pressure and power consumption were measured. Similarities and differences of nanocomposites obtained by these two methods are discussed on the basis of their rheological and mechanical properties and their structural characteristics. J. VINYL ADDIT. TECHNOL., 13:40–45, 2007. © 2007 Society of Plastics Engineers.
The 3D Supramolecular Compound {[Cu2(L‐val)2(4,4′‐bipy)(H2O)2](NO3)2}n (L‐val = L‐valine anion, 4,4′‐bipy = 4,4′‐bipyridine)
Authors: Lou Benyong , Huang Xiaodong , Lin Xiangchao 
Published: February 2007

Abstract{[Cu2(L‐val)2(4,4′‐bipy)(H2O)2](NO3)2}n was synthesized and its crystal structure was determined by X‐ray diffraction. In the presence of 4,4′‐bipyridine, deprotoned L‐valine chelates CuII ions into coordination layers which were linked into a framework by hydrogen‐bonded chains resulting from nitrate anions and water molecules.
Synthesis, Structure and Magnetic Property of an “Adamantane” Type Tetranuclear Iron(III) Complex
Authors: Tian Jin‐Lei , Gu Wen , Yan Shi‐Ping , Liao Dai‐Zheng , Jiang Zong‐Hui 
Published: February 2007

AbstractA new tetranuclear complex [Fe4L2(μ‐O)2(μ‐>OH)2](ClO4)4·H2O (1), (HL = N,N,N′,N′‐tetrakis‐[(2‐pyridyl)methyl]‐2‐hydroxypropane‐1,3‐diamine) has been synthesized and its crystal structure and magnetic properties are shown. X‐ray crystallography reveals that complex 1 contains a quadruply‐charged, tetranuclear iron(III) cation and four perchlorate anions. In 1, the Fe4O6 core is composed of a tetrahedron of iron atoms bridged by six oxygen atoms (two oxo, two hydroxo, and two alkoxo groups from L). This results in an adamantane‐type geometry with the iron atoms occupying the bridgehead positions. Susceptibility data of 1 indicate strong intramolecular antiferromagnetic coupling of high‐spin FeIII atoms.
Hydrolysis and Oxidation of a 1‐Boryl‐1‐silyl‐alkene. Molecular Structures of 9‐Hydroxy‐9‐borabicyclo[3.3.1]nonane and a Bicyclic Oxasilabora‐heptadecane B2(OSiPh2OSiPh2O)3
Authors: Wrackmeyer Bernd , Khan Ezzat , Kempe Rhett 
Published: February 2007

AbstractSlow hydrolysis and oxidation of (Z)‐9‐[1‐chlorodiphenylsilyl)‐2‐phenyl‐vinyl]‐9‐borabicyclo[3.3.1]nonane (1) afforded 9‐hydroxy‐9‐borabicyclo[3.3.1]nonane (2) and the bicyclic oxasilabora‐heptadecane B2(OSiPh2OSiPh2O)3 (3), both of which could be isolated as crystalline materials and studied by X‐ray analysis. Molecules of 2 are associated in the crystal lattice by O‐H‐O bridging. The molecular structure of the diborabicyclo[5.5.5]heptadecane 3 is built by 12‐membered rings with the boron atoms in bridge head positions. The gas phase structures of 2 (2a) and of the parent 3a, B2(OSiH2OSiH2O)3, were optimized at the B3LYP/6‐311+G(d,p) level of theory.
Nickel(II) Complexes of 1‐Alkyl‐1‐azonia‐3,5‐diaza‐7‐phosphatricyclo[3.3.1.13,7]decane – Synthesis and Solid‐State Structures
Authors: Mebi Charles A. , Frost Brian J. 
Published: February 2007

AbstractComplexes [NiI3(mpta)2]I (1) and [NiI3(ppta)2]I (2) have been synthesized by reaction of nickel(II) halide salts with ‐1‐methyl‐1‐azonia‐3,5‐diaza‐7‐phosphatricyclo[3.3.1.13,7]decane iodide (mpta+I−) and 1‐(n‐propyl)‐1‐azonia‐3,5‐diaza‐7‐phosphatricyclo[3.3.1.13,7]decane bromide (ppta+Br−) respectively. The crystal structures of compounds 1 and 2 are described and are similar, with both compounds crystallizing in monoclinic space groups. The geometry about both nickel atoms is that of a trigonal bipyramid with the cationic phosphine ligands found in the axial positions and the iodide ligands arranged in the equatorial plane.
Synthesis, Molecular Structure, Optical Properties and Electrical Conductivity of Zwitterionic Ferrocenyldithiophosphonates
Authors: Karakus Mehmet , Aydogdu Yıldırım , Celik Omer , Kuzucu Veysel , Ide Semra , Hey‐Hawkins Evamarie 
Published: February 2007

AbstractFerrocenyldithiodiphosphetane [FcPS(μ‐S)]2 [Fc = Fe(η5‐C5H4)(η5‐C5H5)] reacts with the aminoethanol derivatives 1‐ethyl‐3‐pyrrolidinol and 2‐(piperazin‐1‐yl)ethanol to give the zwitterionic (O‐ethylammonium)ferrocenyldithiophosphonates $\rm [FcP(S)S(\overline{C_{4}H_{7}N}HEt)]$ (2) and $\rm [FcP(S)S(OC_{2}H_{4}\overline{NHC_{4}H_{8}N}H)]$ (3), which were fully characterized by elemental analysis, IR and NMR spectroscopy and mass spectrometry. The optical and electrical properties of 2 and 3 as well as those of the previously reported [FcP(S)S(OC2H4NHEt2)] (1) were studied. A molecular structure determination of 1 is also reported.
Atomistic Simulation Study of Calcium, Phosphate and Fluoride Ion Association to the Teleopeptide‐Tails of Collagen – Initial Steps to Biomineral Formation
Authors: Schepers Thorsten , Brickmann Jürgen , Hochrein Oliver , Zahn Dirk 
Published: February 2007

AbstractThe attachment of single ions to putative adsorption sites in the tails of collagen fibers is investigated by means of molecular dynamics simulations and discussed with respect to the very early steps of apatite/collagen biomineral formation. Our studies clearly demonstrate an increased flexibility of the tails of the triple‐helical collagen protein. Apart from the termini of the backbone, several side chains were also observed to be freely accessible to ion attachment from aqueous solution. The teleopeptide was systematically scanned for suitable adsorption sites for calcium, phosphate and fluoride ions. Association of these ions was then explored from potential of mean force calculations. The resulting energy profiles reveal a variety of favorable protein‐ion bonds and hint at the suitability of the collagen tails to promote apatite aggregation.
Arachidonic acid regulates the binding of human interferon in human skin fibroblasts
Authors: Menon Sree Devi , Yap W. H. , Lim Andrew , Tan Y. H. 
Published: February 2007

AbstractThe induction of the antiviral state in human fibroblasts by human interferon is inhibited by arachidonic acid, its analogues 5,8,11,14‐eicosatetraynoic and 5,8,11‐eicosatriynoic acids, as well as by sodium arachidonate. The fatty acids myristic or oleic acid and sodium palmitate do not inhibit the antiviral action of interferon. Experiments were conducted to investigate the mechanism by which arachidonic acid could inhibit the action of interferon. No correlation between cellular lipoxygenase activities and the inhibition of antiviral action of interferon was observed in the fatty acid treated cells. Likewise, the cyclooxygenase inhibitors indomethacin and oxyphenylbutazone do not inhibit the interferon‐induced antiviral state. Taken together, the inhibition of interferon action by arachidonates is unlikely to be mediated by cyclooxygenase or lipoxygenase‐generated intermediates, even though arachidonates are known to affect the activity of these enzymesin vitro. Measurement of interferon receptors in the fatty acid treated cells showed that arachidonic acid sodium arachidonate and its analogues decreased the number of human type I interferon receptors available for binding, and inhibited the transcription of the interferon‐induced 6–16 gene and the induction of cellular (2′–5′)‐oligoadenylate synthetase, suggesting the mechanism of inhibition is mediated at the level of the interferon receptor. The significance of the finding that arachidonic acid, a common fatty acid of cells and serum, can affect the antiviral action of interferon is discussed.