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61.
A cost-driving factor in Pyrosequencing is the need for single-stranded PCR products that are usually obtained by biotin-labeling of one primer. We designed new universal primers that allow the introduction of biotin during the specific PCR at either the forward or the reverse primer in a single reaction. When converting five human single nucleotide polymorphism assays from the standard format into the universal format, we obtained pyrograms of similar good quality. Although the universal nonhuman sequences are unlikely to form loop structures, we mostly failed to establish assays without using the proprietary software from Biotage AB. Nevertheless, our universal primer pair adds flexibility to the process of assay design due to optional strand selection and contributes to the reduction of genotyping costs. 相似文献
62.
Miniaturised ultrasonic solvent extraction procedure was developed for the determination of selected polychlorinated biphenyls (PCBs) in soil samples by gas chromatography-mass-selective detection by using 23 factorial experimental design. Recoveries of PCBs from fortified soil samples are over 90% for three different fortification levels between 40 and 120 μg kg−1, and relative standard deviations of the recoveries are below 7%. The limits of detection (LODs) ranged from 0.003 to 0.006 μg kg−1. The performance of the proposed method was compared to traditional shake flask extraction method on the spiked real soil sample and extraction methods showed comparable efficiencies. Proposed miniaturised ultrasonic solvent extraction offers several advantages, i.e., reducing sample requirement for measurement of target compound, less solvent consumption and reducing the costs associated with solvent purchase and waste disposal. 相似文献
63.
We consider perturbed linear systems of difference equations with periodic coefficients. The zero solution of a nonperturbed system is assumed asymptotically stable, i.e., all eigenvalues of the monodromy matrix belong to the unit disk {||<1}. We obtain conditions on the perturbation of this system under which the zero solution of the system is asymptotically stable and also establish continuous dependence of one class of numeric characteristics of asymptotic stability of solutions on the coefficients of the system. 相似文献
64.
Imamoglu Mustafa Aydin Ali Osman Dundar Mustafa S. 《Central European Journal of Chemistry》2005,3(2):252-262
A preconcentration method of gold, palladium and copper based on the sorption of Au (III), Pd (II) and Cu (II) ions on a column
packed with 3-(2-aminoethylamino)propyl bonded silica gel is described. The modified silica gel was synthesized and characterized
by FT-IR and C, H, N elemental analysis. At column preconcentration, the effects of parameters such as pH, volume, flow rate,
matrix constituents of solutions and type of eluent on preconcentration of gold, palladium and copper were studied. The recoveries
of Au (III), Pd (II) and Cu (II) were 98.93±0.51, 98.81±0.36 and 99.21±0.42 % at 95 % confidence level, respectively. The
detection limits (δ) of the elements were 0.032, 0.016 and 0.012 μg ml−1, respectively. The preconcentration method was applied for determination of gold and palladium in certified reference material
SARM 7B and copper in river and synthetic seawater by FAAS. Gold, palladium and copper were determined with relative error
lower than 10 %. 相似文献
65.
E.D. Aydin S. Katsimichas 《Journal of Quantitative Spectroscopy & Radiative Transfer》2005,95(3):349-363
In this paper, the finite-element-spherical harmonics (FE-PN) method is applied to the solution of transient Boltzmann transport equation. Firstly, transport and diffusion calculations are obtained for homogeneous and inhomogeneous circular regions. Results are compared in order to show the effects of different absorption coefficient values on the propagation of photons. Significant differences between two theories are shown to occur especially in cases when the absorption is increased. Secondly, to validate the FE-PN method, results from this method are compared with Monte Carlo calculations for different cases. Comparisons show good agreements between FE-transport and Monte Carlo solutions and demonstrate the correctness of the results obtained. 相似文献
66.
This paper abstracts some results of M. Bresar and J. Vukman [1] on the orthogonal derivations of semiprime rings to (σ, τ)-derivations and generalized (σ, τ)-derivations. 相似文献
67.
We report true left-handed (LH) behavior in a composite metamaterial consisting of a periodically arranged split ring resonator (SRR) and wire structures. We demonstrate the magnetic resonance of the SRR structure by comparing the transmission spectra of SRRs with those of closed SRRs. We have confirmed experimentally that the effective plasma frequency of the LH material composed of SRRs and wires is lower than the plasma frequency of the wires. A well-defined LH transmission band with a peak value of -1.2 dB (-0.3 dB/cm) was obtained. The experimental results agree extremely well with the theoretical calculations. 相似文献
68.
Cubukcu E Aydin K Ozbay E Foteinopoulou S Foteinopolou S Soukoulis CM 《Physical review letters》2003,91(20):207401
We experimentally and theoretically demonstrate single-beam negative refraction and superlensing in the valence band of a two-dimensional photonic crystal operating in the microwave regime. By measuring the refracted electromagnetic waves from a slab shaped photonic crystal, we find a refractive index of -1.94 that is very close to the theoretical value of -2.06. A scanning transmission measurement technique is used to measure the spatial power distribution of the focused electromagnetic waves that radiate from a point source. The full width at half maximum of the focused beam is measured to be 0.21 lambda, which is in good agreement with the finite difference time domain method simulations. We also report a subwavelength resolution for the image of two incoherent point sources, which are separated by a distance of lambda/3. 相似文献
69.
70.
The Bilinear Programming Problem is a structured quadratic programming problem whose objective function is, in general, neither convex nor concave. Making use of the formal linearity of a dual formulation of the problem, we give a necessary and sufficient condition for optimality, and an algorithm to find an optimal solution.Research partially supported by the Office of Naval Research under Contract N00014-69-A-0200-1010 with the University of California. 相似文献