Influences of non-selective interactions of nucleic acids on response rates of nucleic acid fiber optic biosensors

The immobilization of oligonucleotides to solid surfaces can provide a platform of chemistry that is suitable for the development of biosensor and microarray technologies. Experiments were performed using a fiber optic nucleic acid biosensor based on total internal reflection fluorescence to examine the effects of the presence of non-complementary DNA on the detection of hybridization of complementary target DNA. The work has focused on the rates and extent of hybridization in the presence and absence of non-selective adsorption using fluorescein-labeled DNA. A stop-flow system of 137 microL volume permitted rapid introduction and mixing of each sample. Response times measured were on the order of seconds to minutes. Non-selective adsorption of non-complementary oligonucleotides (ncDNA) was found to occur at a significantly faster rate than hybridization of complementary oligomers (cDNA) in all cases. The presence of ncDNA oligonucleotides did not inhibit selective interactions between immobilized DNA and cDNA in solution. The presence of high concentrations of non-complementary genomic DNA had little effect on the extent of hybridization of complementary oligonucleotides, but actually reduced the response times of sensors to cDNA oligonucleotides.     

Tunable infrared generation in KTA and applications

Noncollinear difference frequency mixing of dye laser and Nd:YAG second harmonic (fundamental) radiation from a commercial laser system is employed for the generation of 2.7–5.3 μm (1.6–1.7 μm) radiations in a flux-grown KTiOAsO₁ crystal. The generated radiation is used to scan the methane absorption in the fundamental (v ₃) and its first overtone (2v ₃) band at pressure 90 torr in a laboratory made single pass gas cell of length 33 cm.     

关于K个复相关矩阵相等的检验

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Influences of non-selective interactions of nucleic acids on response rates of nucleic acid fiber optic biosensors

The immobilization of oligonucleotides to solid surfaces can provide a platform of chemistry that is suitable for the development of biosensor and microarray technologies. Experiments were performed using a fiber optic nucleic acid biosensor based on total internal reflection fluorescence to examine the effects of the presence of non-complementary DNA on the detection of hybridization of complementary target DNA. The work has focused on the rates and extent of hybridization in the presence and absence of non-selective adsorption using fluorescein-labeled DNA. A stop-flow system of 137 μL volume permitted rapid introduction and mixing of each sample. Response times measured were on the order of seconds to minutes. Non-selective adsorption of non-complementary oligonucleotides (ncDNA) was found to occur at a significantly faster rate than hybridization of complementary oligomers (cDNA) in all cases. The presence of ncDNA oligonucleotides did not inhibit selective interactions between immobilized DNA and cDNA in solution. The presence of high concentrations of non-complementary genomic DNA had little effect on the extent of hybridization of complementary oligonucleotides, but actually reduced the response times of sensors to cDNA oligonucleotides. Received: 26 September 2000 / Revised: 24 November 2000 / Accepted: 30 November 2000     

QCD phase transition in rotating neutron star,neutrino beaming and gamma-ray bursters

We have studied the emission of neutrinos from a rotating hybrid star. We find that the emission is predominantly confined to a very small angle, provided the core of the star is in a mixed phase of quarks and hadrons and the size of such a mixed phase is small. Annihilation of neutrinos to produce gamma rays has been discussed. The estimated duration of the burst is found to be within the observational range.     

Study of theS-matrix near bound states in the continuum

The behaviour ofS-matrix for potentials generating bound states in continuum in the neighbourhood of the positive bound state energies is studied. It is shown that unlike the case of usual negative energy bound states, theS-matrix does not have a pole at the positive bound state energy but becomes unity at the energy corresponding to bound states in continuum. Calculations ofS-waveS-matrix for a local potential constructed by Stillinger and Herrick and a separable nonlocal potential constructed by the present authors verify these results. Our results indicate that the bound states embedded in continuum constructedvia the von Neumann and Wigner procedure cannot be interpreted as resonances with zero width.