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21.
22.
In this paper, the p-ranks and characteristic polynomials of cyclic difference sets are derived by expanding the trace expressions of their characteristic sequences. Using this method, it is shown that the 3-ranks and characteristic polynomials of the Helleseth–Kumar–Martinsen (HKM) difference set and the Lin difference set can be easily obtained. Also, the p-rank of a Singer difference set is reviewed and the characteristic polynomial is calculated using our approach. 相似文献
23.
Ryan J. Weiss Philip L. S. M. Gordts Dzung Le Ding Xu Jeffrey D. Esko Yitzhak Tor 《Chemical science》2015,6(10):5984-5993
Surfen, bis-2-methyl-4-amino-quinolyl-6-carbamide, was previously reported as a small molecule antagonist of heparan sulfate (HS), a key cell-surface glycosaminoglycan found on all mammalian cells. To generate structure–activity relationships, a series of rationally designed surfen analogs was synthesized, where its dimeric structure, exocyclic amines, and urea linker region were modified to probe the role of each moiety in recognizing HS. An in vitro assay monitoring inhibition of fibroblast growth factor 2 binding to wild-type CHO cells was utilized to quantify interactions with cell surface HS. The dimeric molecular structure of surfen and its aminoquinoline ring systems was essential for its interaction with HS, and certain dimeric analogs displayed higher inhibitory potency than surfen and were also shown to block downstream FGF signaling in mouse embryonic fibroblast cells. These molecules were also able to antagonize other HS–protein interactions including the binding of soluble RAGE to HS. Importantly, selected molecules were shown to neutralize heparin and other heparinoids, including the synthetic pentasaccharide fondaparinux, in a factor Xa chromogenic assay and in vivo in mice. These results suggest that small molecule antagonists of heparan sulfate and heparin can be of therapeutic potential for the treatment of disorders involving glycosaminoglycan–protein interactions. 相似文献
24.
In this paper we discuss fully symmetric integration rules of degree 7 and 9 for the 4-cube. In particular we are interested in good rules. (i.e. rules with all the evaluation points inside the cube and all the weights positive).This work was supported by the Norwegian Research Council for Sciences and Humanities. 相似文献
25.
A Spectrofluorometric method for microdetermination of H2O2 has been developed. The method is based on the oxidation of hydrogen peroxide with ceric ion in acid solution and measurement of the fluorescence during titration of the Ce(III) ions produced. The fluorescent species have excitation and emission maxima at 260 and 360 nm, respectively. The detection limit of measurement by this method was 0.1 ppm hydrogen peroxide. 相似文献
26.
27.
Hilde Lea Lein Øystein Skottun Andersen Per Erik Vullum Edgar Lara-Curzio Randi Holmestad Mari-Ann Einarsrud Tor Grande 《Journal of Solid State Electrochemistry》2006,10(8):635-642
Young’s modulus, strain–stress behavior, fracture strength, and fracture toughness of (0≤×≤1) materials have been investigated in the temperature range 20–1,000°C. Young’s moduli of and , measured by resonant ultrasound spectroscopy, were 130±1 and 133±3 GPa, respectively. The nonlinear stress–strain relationship
observed by four-point bending at room temperature was inferred as a signature of ferroelastic behavior of the materials.
Above the ferroelastic to paraelastic transition temperature, the materials showed elastic behavior, but due to high-temperature
creep, a nonelastic respond reappeared above ∼800°C. The room temperature fracture strength measured by four-point bending
was in the range 107–128 MPa. The corresponding fracture toughness of , measured by single edge V-notch beam method, was 1.16±0.12 MPa·m1/2. The measured fracture strength and fracture toughness were observed to increase with increasing temperature. The fracture
mode changed from intragranular at low temperature to intergranular at high temperature. Tensile stress gradient at the surface
of the materials caused by a frozen-in gradient in the oxygen content during cooling was proposed to explain the low ambient
temperature fracture strength and toughness. 相似文献
28.
In this paper, we investigate the permutation behavior of a class of quadrinomials. Each term of these quadrinomials has a Niho-type exponent, and two sets of coefficient triples making the quadrinomials to be permutations are obtained. We use a substitution to transform the permutation problem into the root distribution problem in the unit circle of certain quadratic and cubic equations. 相似文献
29.
Tor A. Kwembe 《Nonlinear Analysis: Theory, Methods & Applications》2010,73(10):3162-3170
In this paper we consider a semilinear equation with a generalized Wentzell boundary condition. We prove the local well-posedness of the problem and derive the conditions of the global existence of the solution and the conditions for finite time blow-up. We also derive an estimate for the blow-up time. 相似文献
30.
Paul T. Ludford III Shenghua Yang Marcela S. Bucardo Prof. Yitzhak Tor 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(13):e202104472
A new fluorescent ribonucleoside alphabet (mthN) consisting of pyrimidine and purine analogues, all derived from methylthieno[3,4-d]pyrimidine as the heterocyclic core, is described. Large bathochromic shifts and high microenvironmental susceptibility of their emission relative to previous alphabets derived from thieno[3,4-d]pyrimidine (thN) and isothiazole[4,3-d]pyrimidine (tzN) scaffolds are observed. Subjecting the purine analogues to adenosine deaminase, guanine deaminase and T7 RNA polymerase indicate that, while varying, all but one enzyme tolerate the corresponding mthN/mthNTP substrates. The robust emission quantum yields, high photophysical responsiveness and enzymatic accommodation suggest that the mthN alphabet is a biophysically viable tool and can be used to probe the tolerance of nucleoside/tide-processing enzymes to structural perturbations of their substrates. 相似文献