bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics and mechanism of oxidation of indole by HSO
Authors: Meenakshisundaram Subbiah , Sarathi N. 
Published: October 2006

AbstractMechanistic studies on the oxidation of indole [IND] by HSO in aqueous CH3CN medium (80:20 v/v) have been carried out, and the reaction is characterized by the rate law −d[HSO]/dt = k[IND][HSO]HSO and SO are probably the respective electrophiles in acidic and basic mediums. Nucleophilic attack of the ethylenic bond on the persulfate oxygen is envisaged to explain the reactivity. The reaction fails to initiate polymerization, and a radical mechanism is ruled out. Thermodynamic parameters very much suggest a bimolecular process. No significant catalytic activity is observed for the reaction system in the presence of Ag+, Cu2+, and heteroaromatic N‐bases. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 39: 46–51, 2007
Kinetics of Demixing and Remixing Transitions in Aqueous Solutions of Poly(N‐isopropylacrylamide): A Temperature‐Jump1H NMR Study
Authors: Yushmanov Pavel V. , Furó István , Iliopoulos Ilias 
Published: October 2006

AbstractSummary:The time course of the coil‐to‐globule collapse and intermolecular aggregation of poly(N‐isopropylacrylamide) in aqueous solution upon exceeding the lower critical solution temperature (LCST) are investigated by temperature‐jump1H NMR spectroscopy. After the temperature jump, we record the time dependences of (i) the mobile fraction of the polymer chain as revealed by the intensity of the liquid‐like NMR signal, (ii) the local mobility of those chains as revealed by the transverse relaxation timeT2, and (iii) their self‐diffusion coefficientD. The same data are also reported at their temperature‐dependent long‐time limits. The results suggest a sudden, faster than one second, collapse and intermolecular aggregation into globules and a slower reorganization/redistribution of the individual chains among and within the globular and mobile states. We found that all molecular changes are reversible if the temperature remains less than ca. 6–8 K above the LCST for less than a few minutes; under those conditions, experiments upon sudden temperature quench below the LCST show that the aggregates disintegrate and swell into coils in less than a few seconds.1H NMR signal intensity of the methyl groups of 1 wt.‐% PNIPAM dissolved in 0.1MNaCl solution in D2O in a temperature‐jump experiment from 300 to 312 K. The data were recorded by the 90°−τ–(180°−2τ‐)n‐detection of the CPMG pulse sequence.magnified image1H NMR signal intensity of the methyl groups of 1 wt.‐% PNIPAM dissolved in 0.1MNaCl solution in D2O in a temperature‐jump experiment from 300 to 312 K. The data were recorded by the 90°−τ–(180°−2τ‐)n‐detection of the CPMG pulse sequence.
Polymerization of Methyl Acrylate by a 2,6‐Bis(2‐benzimidazyl)pyridine Zirconium Dichloride/MAO Catalyst System
Authors: Cho Hyun Yong , Tarte Naresh Hiraral , Cui Liqiang , Hong Dae Sik , Woo Seong Ihl , Gong Young‐Dae 
Published: October 2006

AbstractSummary: A novel non‐metallocene Zr(IV) complex bearing a bianionic form of the ligand 2,6‐bis(2‐benzimidazolyl)pyridine is synthesized. This Zr complex is an active catalyst for the polymerization of MA via coordination polymerization in the presence of methylaluminoxane MAO. The activity and MWD are increased as the polymerization temperature increases. The maximum activity is observed at Al/Zr molar ratio of 100 and the deactivation is shown above 100, resulting from an inactive bimetallic complex between catalyst and free TMA presented in MAO. Decrease in MWD is observed with higher MAO concentration due to its role in chain transfer during the chain propagation.The reaction of the ligand and catalyst synthesis.magnified imageThe reaction of the ligand and catalyst synthesis.
Cell cycle analysis and interspecies nuclear transfer of in vitro cultured skin fibroblasts of the Siberian tiger (Panthera tigris Altaica)
Authors: Hashem Md. Abul , Bhandari Dilip P. , Kang Sung Keun , Lee Byeong Chun 
Published: October 2006

AbstractThe present study was conducted to examine the effect of cell culture conditions, antioxidants, protease inhibitors (PI), and different levels of dimethylsulfoxide (DMSO) for the promotion of synchronization of different cell cycles of Siberian tiger skin fibroblasts. We also compared the ability of somatic cell nuclei of the Siberian tiger in pig cytoplasts and to support early development after reconstruction. Cell cycle synchronization between nuclear donor and recipient cells is considered to be one of the most crucial factors for successful cloning. Five experiments were performed each with a one‐way completely randomized design involving three replicates of all treatments. Least significant difference (LSD) was used to determine variation among treatment groups. Experiment I focused in the effects of cycling, serum starved and fully confluent stages of Siberian tiger cells on different cell cycles. In Experiment II, the effects of different antioxidants like β‐Mercaptoethanol (β‐ME, 10 µM), cysteine (2 mM), and glutathione (2 mM) were examined after cells were fully confluent without serum starvation for 4 hr. In Experiment III, three PI, namely 6‐dimethylaminopurine (6‐DMAP, 2 mM), cycloheximide (7.5 µg/ml) and cytochalasin B (7.5 µg/ml) were used in the sane manner as in Experiment II. In Experiment IV, different levels of DMSO at 0%, 0.5%, 1.0%, and 2.5% were tested on different cell cycle stages of Siberian tiger examined by Flowcytometry (FACS). In Experiment I, 67.2% of the Siberian tiger skin fibroblasts reached the G0/G1stage (2C DNA content) in fully confluent conditions which was more than the cycling (49.8%) and serum starved (SS) medium (65.5%;P < 0.05). Among the chemically treated group, glutathione (72.6%) and cycloheximide (71.3%) had little bit better results for the synchronization of G0 + G1phases than serum starved and fully confluent. After nuclear transfer we did not see any significant differences on the development of tiger‐porcine reconstructed embryos at cycling, SS and fully confluent. Data indicate that prolonged culture of cells in the absence of serum as well as using different chemicals for this experiment does not imply a shift in the percentage of cells that enter G0/G1and that confluency is sufficient to induce quiescence. This finding can be beneficial in nuclear transfer programs in Siberian tiger, because there are negative effects, such as apoptosis associated with serum starvation. Mol. Reprod. Dev. 74: 403–411, 2007. © 2006 Wiley‐Liss, Inc.
Survivin acts as anti‐apoptotic factor during the development of bovine pre‐implantation embryos
Authors: Park Sae Young , Kim Eun Young , JeOn Kilsoo , Cui Xiang‐Shun , Lee Won Don , Kim Nam‐Hyung , Park Se Pill , Lim Jin Ho 
Published: October 2006

AbstractSurvivin, an inhibitor of apoptotic protein containing a single baculoviral inhibit apoptotic protein repeat domain, is a bifunctional protein that suppresses apoptosis and regulates cell division. Thus, we used double stranded RNA (dsRNA) interference to manipulate survivin expression in bovine embryos and analyze its role in blocking apoptosis and facilitating development of pre‐implantation embryos. In vitro fertilized embryos (1‐cell) were injected with survivin dsRNA, and expression of survivin mRNA was evaluated by real‐time quantitative RT‐PCR. To analyze survivin protein expression, we performed immunocytochemistry using a rabbit anti‐bovine suvivin antibody. Expression levels of survivin mRNA and protein were decreased in the dsRNA group compared to the sham group. Rates of in vitro blastocyst development were lower in the survivin dsRNA‐injected group than in the sham‐injected group. Also, the total cell number seen in blastocysts was decreased in the dsRNA group. TUNEL assays of DNA fragmentation indicated an increased apoptotic index in the dsRNA group compared to the sham group. These results indicate that survivin is important for optimal development of bovine blastocysts and confirm that survivin expression suppresses apoptosis of pre‐implantation embryos. Mol. Reprod. Dev. 74: 582–590, 2007. © 2006 Wiley‐Liss, Inc.
Numerical instability in linearized planing problems
Authors: Wang Xuelian , Day Alexander H. 
Published: October 2006

AbstractThe hydrodynamics of planing ships are studied using a finite pressure element method. In this method, a boundary value problem (BVP) is formulated based on linear planing theory; the planing ship is represented by the pressure distribution acting on the wetted bottom of the ship, and the magnitude of this pressure distribution is evaluated using a boundary element method. The pressure is discretized using overlapping pressure pyramids, known as tent functions, so that the resulting distribution is piece‐wise continuous in both longitudinal and transverse directions. A set of linear algebraic equations for the determination of the pressure is then established using a collocation technique.It is found that the matrix of the linear equations is ill conditioned; this leads to oscillatory behaviour of the predicted pressure distribution if the direct solution method of LU decomposition or Gaussian elimination is used to solve the system of linear equations. In the current study, this numerical instability is analysed in detail. It is found that the problem can be addressed by adopting singular value decomposition (SVD) technique for the solution of the linear equations. Using this method, the hydrodynamic results for flat‐bottomed and prismatic planing ships are calculated and a good agreement is demonstrated with Savitsky's empirical relations. Copyright © 2006 John Wiley & Sons, Ltd.
Numerical solution of the heat equation with nonlinear boundary conditions in unbounded domains
Authors: Koleva Miglena , Vulkov Lubin 
Published: October 2006

AbstractThe numerical solution of the heat equation in unbounded domains (for a 1D problem‐semi‐infinite line and for a 2D one semi‐infinite strip) is considered. The artificial boundaries are introduced and the exact artificial boundary conditions are derived. The original problems are transformed into problems on finite domains. The space semi‐discretization by finite element method and the full approximation by the implicit‐explicit Euler's method are presented. The solvability of the full discretization schemes is analyzed. Computational examples demonstrate the accuracy and the efficiency of the algorithms. Also, the behavior of blowing up solutions is examined numerically. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 379–399, 2007
Finite difference approximate solutions for the Cahn‐Hilliard equation
Authors: Khiari N. , Achouri T. , Ben Mohamed M.L. , Omrani K. 
Published: October 2006

AbstractIn this article, we analyze a Crank‐Nicolson‐type finite difference scheme for the nonlinear evolutionary Cahn‐Hilliard equation. We prove existence, uniqueness and convergence of the difference solution. An iterative algorithm for the difference scheme is given and its convergence is proved. A linearized difference scheme is presented, which is also second‐order convergent. Finally a new difference method possess a Lyapunov function is presented. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 437–455, 2007
Symbolic computation of the potential in a nonlinear Schrödinger equation
Authors: Kaçar Ahmet , Terzi̇oğlu Ömer 
Published: October 2006

AbstractOur purpose in this article is to find a time‐dependent potential of the problem of conducting given initial data to given terminal data in a nonlinear Schrödinger equation. We get a condition for existence of a transferring potential. Using Maple, we give symbolic computations of equations for potential. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 23: 475–483, 2007
Ossification of the interosseous ligaments between the metapodials in horses: a new recording methodology and preliminary study
Authors: Bendrey R. 
Published: October 2006

AbstractThis article presents a methodology for recording and quantifying the ossification of the interosseous ligaments between the metapodials in horses, including a scoring system for defining stages in the development of this lesion. The method is applied to a sample of ten Przewalski's horse skeletons from the National Museum, Prague. This case study demonstrates the nature of this lesion in a sample of unworked animals and presents a preliminary sample for comparison with archaeological assemblages. The results show that the condition can occur in animals that are not worked. They also indicate that age is an important factor in the development of the lesion. The expression of the pathology in this sample appears to be linked to how the weight of the animal acts through the legs, in that it occurs earliest, and is generally more advanced, in the areas that support a greater burden. Copyright © 2006 John Wiley & Sons, Ltd.
Spondylolysis in non‐adult skeletons excavated from a medieval rural archaeological site in England
Authors: Mays S. A. 
Published: October 2006

AbstractSpondylolysis is studied in a large series of non‐adult skeletons, ranging in age at death from 28 weeks gestation to 18 years old, from the deserted medieval village of Wharram Percy. The aim is to shed light on the age of occurrence of the lesion. Among those with complete lumbar spines, the prevalence of spondylolysis is 0.7%. The prevalence in adults from this group is 12% with no age patterning. Age of occurrence of spondylolysis in this population is inferred generally to be during late adolescent or early adult life. This contrasts with a published study of a modern reference group, unselected for activity patterns or medical complaints, which reported that in most cases spondylolytic defects had already formed by 6 years of age. The Wharram Percy group appeared to resemble rather more the pattern seen today in those involved in strenuous activities, such as competitive sports, both in the relatively late age of occurrence of defects and in the eventual high prevalence. This may be consistent with the observation that, during adolescence, individuals in medieval rural communities were beginning to take on adult tasks which would have been physically strenuous. However, it is unclear why individuals from Wharram Percy did not also form defects in early childhood as modern children appear to. A late age of occurrence appears consistent with published data which suggest a paucity of cases in non‐adults in British archaeological populations. Copyright © 2006 John Wiley & Sons, Ltd.
Novel candidate tumour suppressor gene loci on chromosomes 11q23–24 and 22q13 involved in human insulinoma tumourigenesis
Authors: Jonkers YMH , Claessen SMH , Feuth T , Geurts van Kessel A , Ramaekers FCS , Veltman JA , Speel E‐JM 
Published: October 2006

AbstractInsulinomas represent the predominant syndromic subtype of endocrine pancreatic tumours. Previous molecular studies have shown that gain of chromosome 9q rather than MEN1 gene mutation is an important early event in tumour development and that chromosomal instability is associated with metastatic disease. In order to identify new gene loci and to define further the critical genetic events in insulinoma tumourigenesis, 27 insulinomas were investigated by array‐based comparative genomic hybridization (array CGH) on 3.7 k genomic BAC arrays (resolution ≤1 Mb). Fluorescence in situ hybridization was used to validate alterations in a subset of tumours. Array CGH most frequently detected loss of chromosomes 11q and 22q and gains of chromosome 9q. The chromosomal regions of interest (CRI) included 11q24.1 (56%), 22q13.1 (67%), 22q13.31 (56%), and 9q32 (63%). Evaluation of the simultaneous occurrence of these aberrations in the individual tumours revealed that gain of 9q32 and loss of 22q13.1 are early genetic events in insulinomas, occurring independently of the other alterations. In tumours with increased genomic complexity, these alterations were often detected simultaneously, occurring in the same tumour cells. Losses of 11q24.1 and 22q13.31 were also associated with these more advanced tumour cases. The CRIs identified most likely harbour crucial candidate genes important in insulinoma tumourigenesis. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Field and thermionic‐field transport in GaAs/AlGaAs/GaAs heterojunction barriers
Authors: Morgan D. V. , Porch A. , Krishna R. 
Published: October 2006

AbstractThis paper considers the transport of conduction band electrons as a result of tunneling through a triangular potential barrier fabricated within a GaAs/Alx Ga1–x As/GaAs heterojunction. The triangular barrier was formed by the composition grading of the Alx Ga1–x As region from x = 0 to x = 0.3, which forms part of a cathode emitter in a commercial Gunn diode. The experimental data for the current–voltage characteristics obtained for a range of temperatures from 77 to 273 K were used to test a simplified thermionic‐field model. Good agreement has been obtained between theory and experiment, thus confirming the usefulness of this simple model for device evaluation. The comparison of the data over the experimental temperature range shows that the thermionic‐field emission observed at 273 K gives way to field emission at 77 K. This is a result of the removal of the more energetic electrons in the conduction band at lower temperatures. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structural and optical properties of InSb quantum dots for mid‐IR applications
Authors: Tasco V. , Deguffroy N. , Baranov A. N. , Tournié E. , Satpati B. , Trampert A. 
Published: October 2006

AbstractWe investigate the MBE growth and properties of Sb‐based nanostructures, very promising candidates as active material for mid infrared light sources operating between 3 and 5 μm. We show that the key feature for the fabrication of highly dense and optically efficient InSb quantum dots is the control of In‐adatoms mobility. We obtain defect‐free nanostructures with a density as high as 8 × 1010 dots/cm2 together with improved performance in terms of optical emission. Photoluminescence and electroluminescence emissions, peaked at around 360 meV, have been measured which exhibit a linewidth of 47 meV at 90 K. The emission is detected up to room temperature, with an intensity quenching factor as low as 4 from 90 K to 300 K, demonstrating good thermal stability of the material. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Depression of excitonic energy transfer by freezing molecular vibrations in meta ‐linked branching dendrimers
Authors: Akai I. , Kato T. , Okada A. , Kanemoto K. , Karasawa T. , Kimura M. , Ohashi M. , Shinoda S. , Tsukube H. 
Published: October 2006

AbstractThe temperature dependence of excitonic energy transfer is investigated in both small and large dendrimers having meta ‐linked light‐harvesting peripheries. In these dendrimers, highly efficient excitonic energy transfer takes place from peripheries to core at room temperature and gives rise to intense core photoluminescence (PL) upon selective excitation of the peripheries. Upon direct photo‐excitation of the core chromophore, the intensity of core‐PL increases monotonically with decreasing temperature. However, during selective excitation of the peripheries, the enhancement of the core‐PL is markedly suppressed at temperatures lower than 100 K in both dendrimers. This result demonstrates that torsional vibrations of adjoining aromatic rings in the peripheries mediate excitonic energy transfer, and that the freezing of such vibrations at low temperature strongly inhibits the transfer in these meta ‐linked dendrimers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Morphology changes of CuCl thin films induced by photo‐irradiation
Authors: Hasuo Masahiro , Shimamoto Atsuyoshi , Fujiwara Takeshi 
Published: October 2006

AbstractWe have irradiated CuCl films, which are prepared by a vacuum vapor deposition method, with pico‐second light pulses of 82 MHz repetition rate at the photon energy of 3.290 eV. After a long time of photo‐irradiation, the photo‐irradiated region is recognized by eye for thin films. We observe the surface morphology by atomic force microscopy at room temperature. For a 50 nm thick film, surface structure changes such as surface smoothing, nanometer‐scale and micrometer‐scale structures formation are observed, which depend on the position in the photo‐irradiated region, while such changes are not detected for a 200 nm thick film. The effects of ablation and local heating by the photo‐irradiation are excluded for the mechanism of the observed morphology change. The abundance change of Cu and Cl in the film is also detected by the Auger microprobe measurement. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
First principles calculation of optical and electronic properties with inclusion of exciton effects
Authors: Ismail‐Beigi Sohrab 
Published: October 2006

AbstractFirst principles theory and methodology have made rapid advances in their ability to describe electronic excitations and optical properties from first principles. Here we present an overview of the progress in this field. We illustrate with results for three systems that exhibit interesting excitonic behavior: single‐walled carbon nanotubes, single‐walled gallium nitride nanotubes, and self‐trapped excitons in silica. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The role of breathers in the anomalous decay of luminescence
Authors: Mihóková Eva , Schulman Lawrence S. 
Published: October 2006

AbstractLuminescence of alkali halides doped by heavy ns2 ions exhibits an anomaly in the slow component emission decay. The anomaly is explained by the formation of a discrete breather in the immediate neighborhood of the impurity. We study properties of these breathers, their phase space structure, robustness, and propensity for formation. Under a wide range of parameters and interionic potentials they form 2‐dimensional Kolmogorov‐Arnold‐Moser tori (less than generic) in phase space. We show strobed views of these tori, useful in quantization. All features support the thesis of breather formation as the explanation for the luminescence decay anomaly that first motivated our breather proposal. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ultrafast time‐resolved infrared luminescence spectroscopy in halogen‐bridged Pd complexes
Authors: Takahashi Youtarou , Kitagawa Hiroshi , Suemoto Tohru 
Published: October 2006

AbstractThe ultrafast luminescence spectroscopy on [PdBr(chxn=cyclohexanediamine)2]Br2 was performed from near to mid infrared region. The instantaneous luminescence with a large Stokes shift indicated the ex‐istence of the large lattice relaxation in excited states. The temporal waveform of the luminescence showed ultrafast decay and the decay time constant is smaller than 300 fs in low energy region. This tendency of the waveform is different from that of self‐trapped exciton and consistent with the wavepacket motion on the potential surface with no barrier. The result suggests the appearance of a excited state that is different from the ordinary self‐trapped exciton. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Laser‐induced oxygen vacancy formation and diffusion on TiO2 (110) surfaces probed by photoemission electron microscopy
Authors: Xiong Gang , Joly Alan G. , Beck Kenneth M. , Hess Wayne P. 
Published: October 2006

AbstractPhotoemission electron microscopy is used to probe photon‐induced oxygen vacancies generated on TiO2 (110)‐(1×2) surfaces. An increased oxygen vacancy concentration within the irradiated region leads to an increase of local photoelectron emission. The local oxygen deficient region can be compensated by exposing the surface to molecular oxygen at 1×10–5 Torr, or via surface diffusion at 450 K in vacuum. The surface diffusion coefficient is estimated to be on the order of 10–12 m2/s. Photoemission electron microscopy allows in situ studies of surface electronic defect formation and removal. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)