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991.
992.
Ryan C. Branski Clark A. Rosen Katherine Verdolini Patricia A. Hebda 《Journal of voice》2005,19(2):283-289
This study seeks to determine the ability of enzyme-linked immunosorbent assays (ELISAs) of vocal fold secretions to detect and describe the acute tissue response to injury in a rabbit vocal fold model. Vocal fold secretions were collected before the induction of a unilateral surgical injury to the vocal fold and at 6 timepoints after injury (1, 5, 7, 10, 14, and 21 days). Secretions were then subjected to ELISAs to assess concentrations of interleukin-1 beta (IL-1beta) and prostaglandin-E2 (PGE-2). The results indicate that ELISAs may be useful in documenting fluctuations in these markers associated with the wound healing process in the rabbit model. The temporal expression of both IL-1beta and PGE-2 was consistent with their proposed roles in the wound healing cascade in other systems, pointing to the potential that surface secretions may be at least partial indicators of wound healing events within the tissue. 相似文献
993.
Teresa Velilla Katherine Delgado Raúl Quijada Daniela Bianchini Griselda Barrera Galland João Henrique Z. Dos Santos Diana P. Fasce Roberto J. J. Williams 《Journal of polymer science. Part A, Polymer chemistry》2007,45(23):5480-5486
We report the synthesis of a supported metallocene catalyst that exhibits the same activity as a homogeneous catalyst for ethylene polymerization reactions. The key to this new catalytic system is a hybrid organic–inorganic polymer obtained by the cocondensation of an organotrialkoxysilane (OTAS; 40 mol %) with tetraethoxysilane (TEOS; 60 mol %). The particular organic group of OTAS enabled us to avoid gelation when the hydrolytic condensation was performed with a thermal cycle attaining 150 °C. The resulting product [soluble functionalized silica (SFS)] was a glass at room temperature that was soluble in several organic solvents such as tetrahydrofuran and toluene. The 29Si NMR spectrum of SFS showed that the OTAS units were fully condensed (T3 species), whereas the TEOS units were mainly present as tricondensed (Q3) and tetracondensed (Q4) units. SFS was grafted onto activated silica through a reaction of silanol groups. The metallocene [(nBuCp)2ZrCl2] was covalently bonded to the SFS‐modified support. The polymerization of ethylene was carried out in toluene in the presence of methylaluminoxane. The activity of the supported catalyst was similar to that of the metallocene catalyst in solution. The simplest explanation accounting for this fact is that most of the metallocene was grafted to SFS species issuing from the surface of the support through a reaction with their silanol groups. This improved the accessibility of the monomer to the reaction sites. Specific interactions of the metallocene species with neighboring organic branches of SFS might also affect the catalytic activity. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5480–5486, 2007 相似文献
994.
A. Sibirtsev H. -W. Hammer U. -G. Meißner A. W. Thomas 《The European Physical Journal A - Hadrons and Nuclei》2006,29(2):209-220
We study coherent and incoherent φ-meson photoproduction from nuclei. The available data are analyzed in terms of single-
and coupled-channel photoproduction. It is found that the data on coherent photoproduction can be well reproduced within a
single-channel optical model and show only little room for ω-φ mixing. These data indicate a normal distortion of the φ-meson
in nuclei, which is compatible with the results obtained through the vector meson dominance model. The data on incoherent
φ-meson photoproduction show an anomalous A-dependence resulting in a very strong φ-meson distortion. These data can be explained by a coupled-channel effect through
the dominant contribution from the ω↦φ or the π↦φ transition or, more speculative, through the excitation of a cryptoexotic
B
φ-baryon. 相似文献
995.
Experimental facts attesting to a two-phase (liquid-metal-vapor) state of the matter in the core produced in a high-power
discharge through thin wires are presented. The modern technique of multiframe x-ray shadow photography has made it possible
to observe vapor bubbles in the core and their interaction with the shock wave penetrating from the corona.
Pis’ma Zh. éksp. Teor. Fiz. 69, No. 5, 349–354 (10 March 1999) 相似文献
996.
T. Hammer 《等离子体物理论文集》1999,39(5):441-462
997.
Let π1(C) be the algebraic fundamental group of a smooth connected affine curve, defined over an algebraically closed field of characteristic
p > 0 of countable cardinality. Let N be a normal (respectively, characteristic) subgroup of π
1(C). Under the hypothesis that the quotient π
1(C)/N admits an infinitely generated Sylow p-subgroup, we prove that N is indeed isomorphic to a normal (respectively, characteristic) subgroup of a free profinite group of countable cardinality.
As a consequence, every proper open subgroup of N is a free profinite group of countable cardinality.
Amílcar Pacheco and Pavel Zalesskii were partially supported by CNPq research grants 305731/2006-8 and 307823/2006-7, respectively.
They were also supported by Edital Universal CNPq 471431/2006-0. 相似文献
998.
Gareth W. Lamb Katherine E. Jolley Jonathan M.J. Williams 《Tetrahedron letters》2009,50(26):3374-1864
Alcohols have been converted into a range of protected amines including sulfonamides and N-alkylbenzylamine derivatives. Representative examples of deprotection to afford primary amines are also provided. 相似文献
999.
The optical properties of slab-like photonic crystals are often discussed on the basis of effective index (EI) approximations,
where a 2-D effective refractive index profile replaces the actual 3-D structure. Our aim is to assess this approximation
by analogous steps that reduce finite 2-D waveguide Bragg-gratings (to be seen as sections through 3-D PC slabs and membranes)
to 1-D problems, which are tractable by common transfer matrix methods. Application of the EI method is disputable in particular
in cases where locally no guided modes are supported, as in the holes of a PC membrane. A variational procedure permits to
derive suitable effective permittivities even in these cases. Depending on the structural properties, these values can well
turn out to be lower than one, or even be negative. Both the “standard” and the variational procedures are compared with reference
data, generated by a rigorous 2-D Helmholtz solver, for a series of example structures. 相似文献
1000.
Andrew McGlashon Weimin Zhang Detlef M. Smilgies Maxim Shkunov Kristijonas Genevicius Katherine S. Whitehead Aram Amassian George G. Malliaras Donal D.C. Bradley Martin Heeney Alasdair J. Campbell 《Current Applied Physics》2012
3′-methyl-(5,5′′-bis[3-ethyl-3-(6-phenyl-hexyloxymethyl)-oxetane])-2,2′:5′,2′′-terthiophene (5T(Me)Ox) is a solution processable small molecule semiconductor displaying smectic-C and nematic liquid crystal phases. The pendant oxetane group can be polymerized in situ in the presence of a suitable photoacid at concentrations ≥1% by weight. Spin-coated films of pure 5T(Me)Ox and 5T(Me)Ox doped with the soluble photoacid were characterized by absorption and photoluminescent spectroscopy. Thick pristine films showed absorption and emission from a crystalline phase. Thin monolayer (<5 nm) films, as well as thicker photoacid doped films, instead showed absorption from an H-aggregate phase and emission from an excimer. Optical microscopy showed a significant change in film structure upon addition of the photoacid; large and well-orientated crystals being replaced by much smaller domains which appear to vary in thickness. Grazing Incidence Wide Angle X-Ray Scattering (GIWAXS) was used to characterize the packing and orientation of molecules in the crystalline and doped samples. The results are consistent with the photoacid doped samples forming layers of H-aggregate phase monolayer sheets parallel to the substrate where the photoacid inhibits the transition into the three-dimensionally ordered crystalline phase. Field-effect transistors and light emitting diodes were constructed incorporating 5T(Me)Ox as the active layer. Pure 5T(Me)Ox field-effect transistors showed good, p-type device characteristics, but the morphological changes upon doping result in a loss of transistor action. In the diodes, curing through melting and exposure to UV light followed by photoacid removal resulted in an increase in current density but a decrease in light emission. These results indicate that the presence of the photoacid (≥1% by weight) can have a dramatic effect on the structure, morphology and device performance of ordered, photopatternable materials for organic electronics. 相似文献