排序方式: 共有72条查询结果,搜索用时 593 毫秒
31.
Modular aptameric sensors 总被引:7,自引:0,他引:7
We report the first examples of modular aptameric sensors, which transduce recognition events into fluorescence changes through allosteric regulation of noncovalent interactions with a fluorophore. These sensors consist of: (a) a reporting domain, which signals the binding event of an analyte through binding to a fluorophore; (b) a recognition domain, which binds the analyte; and (c) a communication module, which serves as a conduit between recognition and signaling domains. We tested recognition regions specific for ATP, FMN, and theophylline in combinations with malachite green binding aptamer as a signaling domain. In each case, we were able to obtain a functional sensor capable of responding to an increase in analyte concentration with an increase in fluorescence. Similar constructs that consist only of natural RNA could be expressed in cells and used as sensors for intracellular imaging. 相似文献
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We screened a series of RNA and DNA aptamers for their ability to serve in the dye displacement assays in which analytes compete
with TO dye. We conclude that, while the performance of the TO dye displacement approach is not always predictable, it is
still a simple and sensitive assay to detect binding between RNA aptamers and small molecules. In particular, we describe
efficient assays for tobramycin and theophylline, with up to 90% displacement of TO observed, and we describe the first aptameric
assay for cAMP.
Figure An RNA or DNA aptamer against a molecule (circle) binds TO dye, resulting in a fluorescent complex. Presence of free molecule in solution results in the displacement of TO
from the complex and a reduction in fluorescence
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Nonlinear Dynamics - Intensive research in the field of mathematical modeling of hydraulic servo systems has shown that their mathematical models have many important details which cannot be... 相似文献
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Yang KA Pei R Stefanovic D Stojanovic MN 《Journal of the American Chemical Society》2012,134(3):1642-1647
We report a straightforward evolutionary procedure to build an optimal sensor array from a pool of DNA sequences oriented toward three-way junctions. The individual sensors were mined from this pool under separate selection pressures to interact with four steroids, while allowing cross-reactivity, in a manner designed to achieve perfect classification of individual steroids. The resulting sensor array had three sensors and displayed discriminatory capacity between steroid classes over full ranges of concentrations. We propose that similar protocols can be used whenever we have two or more classes of samples, with individual classes being defined through gross differences in ratios of dominant families of responsive components. 相似文献
37.
The synthesis of a series of lanthanide tetracyanoplatinates all incorporating 2,2′:6′,2″-terpyridine (terpy) have been carried out by reaction of Ln3+ nitrate salts with terpy and potassium tetracyanoplatinate. The incorporation of different Ln3+ cations results in the isolation of [Ln(DMF)2(C15H11N3)(H2O)2(NO3)]Pt(CN)4 (Ln=La-Nd, Sm-Yb) under otherwise identical reaction conditions. These compounds have been isolated as single crystals and X-ray diffraction has been used to investigate their structural features. All of the reported compounds are isostructural. Crystallographic data for the representative Eu3+ compound (EuPt) are (MoKα, λ=0.71073 Å): monoclinic, space group P21/c, a=10.1234(4) Å, b=18.7060(7) Å, c=17.1642(5) Å, β=97.249(3)°, V=3224.4(2), Z=4, R(F)=2.78% for 426 parameters with 7724 reflections with I>2σ(I). The structure consists of a zero-dimensional, ionic salt containing complex [Eu(DMF)2(C15H11N3)(H2O)2(NO3)]2+ cations and anions. The complex cations contain the Eu3+ ions in a tri-capped trigonal prismatic coordination environment with one terdentate 2,2′:6′,2″-terpyridine molecule, one bidentate nitrate anion, two O-bound dimethylformamide molecules, and two coordinated water molecules. Photoluminescence data illustrate that EuPt displays intramolecular energy transfer from the coordinated terpy molecule to the Eu3+ cation. The uncoordinated tetracyanoplatinate anion also exhibits visible emission. 相似文献
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Gordana Stojanovic 《Geometriae Dedicata》2006,123(1):1-10
We introduce (k,l)-regular maps, which generalize two previously studied classes of maps: affinely k-regular maps and totally skew embeddings. We exhibit some explicit examples and obtain bounds on the least dimension of a
Euclidean space into which a manifold can be embedded by a (k,l)-regular map. The problem can be regarded as an extension of embedding theory to embeddings with certain non-degeneracy conditions
imposed, and is related to approximation theory. 相似文献
39.
Replacement of calcium with europium in the phases Ca21Ni2Zn36 and CaNi2Zn3 was attempted to explore the possibility of substitution in metal flux reactions and potential magnetic interactions between closely spaced Eu2+ ions. Limited substitution occurs when Eu is added to the reaction of nickel in a Ca/Zn flux mixture, up to stoichiometries of Eu5.8(3)Ca15.2(3)Ni2Zn36 and Eu0.42(8)Ca0.58(8)Ni2Zn3. Structural characterization and magnetic susceptibility studies on EuxCa21−xNi2Zn36 phases indicate that the Eu and Ca ions do not form an even solid solution on their sites, but instead segregate in separate regions of the crystals. The europium-rich regions of the samples order ferromagnetically, with TC dependent on the size of the clusters. If the concentration of Eu in the flux is raised above 20 mol%, a new compound Eu1.63(1)Ca1.37(1)Ni2Zn3 (Cmcm, a=4.1150(5) Å, b=16.948(2) Å, c=10.302(1) Å, Z=4, R1=0.0396) is produced. 相似文献
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Goran Stojanovic Mirjana Damnjanovic Vladan Desnica Ljiljana Zivanov Ramesh Raghavendra Pat Bellew Neil Mcloughlin 《Journal of magnetism and magnetic materials》2006
This paper describes the design, modeling, simulation and fabrication of zig-zag and meander inductors embedded in low- or high-permeability soft ferrite material. These microinductors have been developed with ceramic coprocessing technology. We compare the electrical properties of zig-zag and meander inductors structures installed as surface-mount devices. The equivalent model of the new structures is presented, suitable for design, circuit simulations and for prediction of the performance of proposed inductors. The relatively high impedance values allow these microinductors to be used in high-frequency suppressors. The components were tested in the frequency range of 1 MHz–3 GHz using an Agilent 4287A RF LCR meter. The measurements confirm the validity of the analytical model. 相似文献