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71.
The simplified sialyl Lewisx mimic 5 containing a D ‐arabinose, a 3‐cyclohexyl‐2‐hydroxypropanoate, and a tetrahydropyran building block instead of L ‐fucose, sialic acid, and N‐acetylglucosamine, respectively was synthesized. Compound 5 was 10‐fold more potent than sLex in a static E‐selectin binding assay and showed at 50 μM 75% inhibition in a dynamic‐flow assay in which sLex did not inhibit neutrophil rolling at up to 1000 μM . Compound 7 with a lactic acid instead of sialic acid building block showed threefold improved potency compared to sLex. 相似文献
72.
Irradiation of dicarbonyl(η5-cyclopentadienyl)iron dimer 1 or decacarbonyldimanganese ( 2 ) in the presence of alkyl halides leads to C-centered radicals which can be trappedby alkenes and yields saturated and/or unsaturated addition products. Carbon radicals are generated via halogen abstraction by the initially formed metal-centered radicals resulting from homolysis of the metal-metal bond of dimeric mediators 1 and 2 . No reaction occurs using octacarbonyldicobalt ( 3 ). 相似文献
73.
Volha A. Matylitskaya Wolfgang Bock Klaus Thoma Bernd O. Kolbesen 《Mikrochimica acta》2006,156(1-2):33-37
The oxidation and nitridation processes of niobium films in a rapid thermal processing (RTP) – system were investigated. 200
and 500 nm niobium films were deposited via sputtering on sapphire-(1-102)-substrate. At first niobium films were oxidized
in molecular oxygen at temperatures ranging from 350 to 500 °C and for times of 1, 2 and 5 min and then nitridated in ammonia
at 1000 °C for 1 min using an RTP system. For characterisation of the niobium films complementary analytical methods were
used: X-ray diffraction (XRD) for phase analysis, secondary ion mass spectrometry (SIMS) for determining the elemental depth
profiles of the films, scanning electron microscopy (SEM) and atomic force microscopy (AFM) for characterisation of the surface
morphology of the films. The influence of the substrate, single crystalline sapphire, on the reactivity of the niobium films
was studied in dependence of temperature, time of reaction and film thickness. The possibility of existence of niobium oxynitride
phase was investigated. According to XRD and SIMS data, there is evidence that an oxynitride phase is formed after oxidation
and subsequent nitridation in the bulk of some Nb films. In some of the experiments crack formation in the films or even delamination
of the Nb films from the substrates was observed. 相似文献
74.
Zusammenfassung Es wird über Apparatur zur Untersuchung der chemischen Reaktionen des Schwefelmonoxyds mit flüssigen Reaktionspartnern berichtet.Es werden mit Hilfe dieser Apparatur die Reaktionen des SO mit einer größeren Zahl org. Substanzen untersucht.Es wird im einzelnen berichtet, daß SO mit der überwiegenden Anzahl der untersuchten org. Substanzen, sowohl cyclischen als auch anderen, unter Bildung von Sulfonsäuren reagiert. Außerdem konnte auch das Oxydationsvermögen des SO an Hand der Oxydation des Methanols zum Formaldehyd und des Benzylalkohols zum Benzaldehyd und zur Benzoesäure konstatiert werden.Eine weitere eigenartige Reaktion ist die Bildung von Dibenzamid aus Benzonitril.Weiterhin wurde im Anisol ein indifferentes Lösungsmittel für Schwefelmonoxyd aufgefunden.Mit 1 Abbildung. 相似文献
75.
Transport in Porous Media - The possibility of broaching, or the release of fluids at the seafloor due to a damaged or faulty well, is a hazard that must be assessed in the well permitting process.... 相似文献
76.
Weichao Shi Wei Li Kris T. Delaney Glenn H. Fredrickson Edward J. Kramer Christos Ntaras Apostolos Avgeropoulos Nathaniel A. Lynd 《Journal of polymer science. Part A, Polymer chemistry》2016,54(2):169-179
Here, we report the morphology variation in a series of PS-b-PI-b-PS' asymmetric triblock copolymer and PS homopolymer (hPS) blends, where PS' and PS are polystyrene blocks with a molecular weight ratio of approximately 0.11 and PI is poly(isoprene). We find that adding a small amount of hPS results in significant order–order transition (OOT) boundary deflection toward higher PS volume fractions fPS, which is accompanied by morphology re-entry. For example, the neat triblock copolymer with a PS + PS' volume fraction of fPS = 0.38 exhibits a lamellar microphase; adding a small amount of hPS reverts the morphology into a hexagonal phase with PS cylinders, while further increasing the hPS fraction leads to normal OOTs from PS cylinders to lamellae, to PI cylinders and finally to spheres. The morphology variation reported here is significantly different from that reported in binary blends of diblock or symmetric triblock copolymer with homopolymer. While the domain features of the LAM structure can be correctly reproduced by self-consistent field theory (SCFT), the observed morphology re-entry is absent in the theoretical SCFT phase diagram. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016, 54, 169–179 相似文献
77.
A. Thoma 《Archiv der Mathematik》2000,74(1):22-25
The binomial arithmetical rank of a binomial ideal I is the smallest integer s for which there exist binomials f1,..., fs in I such that rad (I) = rad (f1,..., fs). We completely determine the binomial arithmetical rank for the ideals of monomial curves in PKnP_K^n. In particular we prove that, if the characteristic of the field K is zero, then bar (I(C)) = n - 1 if C is complete intersection, otherwise bar (I(C)) = n. While it is known that if the characteristic of the field K is positive, then bar (I(C)) = n - 1 always. 相似文献
78.
Roser Sabater i Serra Apostolos Kyritsis Jorge L. Escobar Ivirico Andreu Andrio Balado Jose Luis Gómez Ribelles Polykarpos Pissis Manuel Salmerón-Sánchez 《Colloid and polymer science》2010,288(5):555-565
Poly(L-lactide) networks (PmLA) hydrophilized with different amounts of 2-hydroxyethyl acrylate (HEA) were investigated by
dielectric relaxation spectroscopy, thermally stimulated depolarization currents, and differential scanning calorimetry. The
incorporation of HEA units in the PmLA network, with the aim of modulating the water sorption capacity of the system, results
in a material with a complex behavior. The system consists of phase-separated microdomains richer in one or the other comonomers
that constitute the network. Initially, the addition of smalls amount of HEA units in the network gives rise to a one-phase,
two-component system; however, when the amount of HEA in the system increases, a new phase (HEA-rich one) is formed containing
some mLA chains that modify the main relaxation mode of these domains and the local dynamics of the system. The structure
of the system has been analyzed by comparing the relaxational modes in the PmLA and PHEA homonetworks with those in the copolymer
networks. 相似文献
79.
Stathis Chadjiconstantinidis Apostolos D. Papaioannou 《Insurance: Mathematics and Economics》2009,45(3):470-484
In this paper we consider a risk model with two independent classes of insurance risks. We assume that the two independent claim counting processes are, respectively, the Poisson and the generalized Erlang(2) process. We prove that the Gerber-Shiu function satisfies some defective renewal equations. Exact representations for the solutions of these equations are derived through an associated compound geometric distribution and an analytic expression for this quantity is given when the claim severities have rationally distributed Laplace transforms. Further, the same risk model is considered in the presence of a constant dividend barrier. A system of integro-differential equations with certain boundary conditions for the Gerber-Shiu function is derived and solved. Using systems of integro-differential equations for the moment-generating function as well as for the arbitrary moments of the discounted sum of the dividend payments until ruin, a matrix version of the dividends-penalty is derived. An extension to a risk model when the two independent claim counting processes are Poisson and generalized Erlang(ν), respectively, is considered, generalizing the aforementioned results. 相似文献
80.
Chiotellis A Tsoukalas C Pelecanou M Papadopoulos A Raptopoulou C Terzis A Pirmettis I Papadopoulos M Chiotellis E 《Inorganic chemistry》2006,45(14):5635-5640
The present paper deals with the synthesis and structural characterization of novel neutral oxorhenium(V) complexes of the general formula ReO[SNO][NN]. The simultaneous action of the tridentate SNO ligand, N-(2-mercaptoacetyl)glycine (1), and the bidentate NN ligand, N-phenylpyridine-2-aldimine (2), on ReOCl3(PPh3)2 leads to the formation of two isomers 4a and 4b of the general formula ReO[SNO][NN], as a result of the different orientations of the NN ligand. In both cases, the SNO donor atoms of the tridentate ligand occupy the three positions in the equatorial plane of the distorted octahedron, whereas the oxo group is always directed toward one of the apical positions. In the first isomer, 4a, the imino nitrogen of the NN ligand occupies the fourth equatorial position and the pyridine type nitrogen is directed trans to the oxo group, while in the second isomer, 4b, the imino nitrogen of the NN ligand occupies the apical position trans to the oxo group and the pyridine type nitrogen completes the equatorial plane of the distorted octahedron. The [SNO][NN] mixed-ligand system was applied in the synthesis of the oxorhenium complex 5 in which the 1-(2-methoxyphenyl)piperazine moiety, a fragment of the true 5-HT1A antagonist WAY 100635, has been incorporated in the NN bidentate ligand (NN is N-{3-[4-(2-methoxyphenyl)piperazin-1-yl]propyl}pyridine-2-aldimine). In this case, high-performance liquid chromatography and NMR showed the existence of one isomer, 5, in which the pyridine nitrogen is trans to the oxo core, as demonstrated by crystal structure analysis. 相似文献