排序方式: 共有21条查询结果,搜索用时 15 毫秒
1.
Kossen K Vaish NK Jadhav VR Pasko C Wang H Jenison R McSwiggen JA Polisky B Seiwert SD 《Chemistry & biology》2004,11(6):807-815
Many reports have suggested that target-activated ribozymes hold potential value as detection reagents. We show that a "half"-ribozyme ligase is activated similarly by three unstructured oligoribonucleotides representing the major sequence variants of a hepatitis C virus 5'-untranslated region (5'-UTR) target and by a structured RNA corresponding to the entire 5'-UTR. Half-ribozyme ligation product was detected both in an ELISA-like assay and in an optical immunoassay through the use of hapten-carrying substrate RNAs. Both assay formats afford a limit of detection of approximately 1 x 10(6) HCV molecules (1.6 attomol, 330 fM), a sensitivity which compares favorably to that provided by standard immunoassays. These data suggest that target-activated ribozyme systems are a viable approach for the sensitive detection of viral nucleic acids using high-throughput platforms. 相似文献
2.
M. Niyaz Ahamad Rahul Vaish K. B. R. Varma 《Journal of Thermal Analysis and Calorimetry》2011,105(1):239-243
Glasses of the composition 2TeO2–V2O5 were fabricated via the conventional melt-quenching technique. The amorphous and the glassy nature of the as-quenched samples
were confirmed by X-ray powder diffraction (XRD) and differential scanning calorimetry (DSC), respectively. The glass transition
and crystallization parameters were evaluated under non-isothermal conditions using DSC. X-ray diffraction studies confirmed
the presence of partially oriented crystallites in the heat-treated glasses. Kauzmann temperature (lower bound for the kinetically
observed glass transition) was deduced from the heating rate dependent glass transition and crystallization temperatures. 相似文献
3.
Optically clear glasses in the ZnO–Bi2O3–B2O3 (ZBBO) system were fabricated via the conventional melt-quenching technique. Dielectric constant and loss measurements carried out on ZBBO glasses unraveled nearly frequency (1 kHz–10 MHz)-independent dielectric characteristics associated with significantly low loss (D?=?0.004). However, weak temperature response was found with temperature coefficient of dielectric constant 18?±?4 ppm °C?1 in the 35–250 °C temperature range. The conduction and relaxation phenomena were rationalized using universal AC conductivity power law and modulus formalism respectively. The activation energy for relaxation determined using imaginary parts of modulus peaks was 2.54 eV which was close to that of the DC conduction implying the involvement of similar energy barriers in both the processes. Stretched and power exponents were temperature dependent. The relaxation and conduction in these glasses were attributed to the hoping and migration of Bi3+ cations in their own and different local environment. 相似文献
4.
The channelling of 3 MeV protons in the 〈110〉 direction of silicon has been simulated using Vineyard model taking into account
thermally vibrating nuclei and energy loss due to ion-electron interactions. A beam made up of constant energy particles but
with spatial divergence has been simulated for the purpose. The values of the minimum scattering yield and half width of the
channelling dip are shown to be depth sensitive and agree well with the measured values. The dependence of yield on the angle
of incidence has been found to give information of all three types of channelling. The critical angles for the three types
of channelling and wavelength of planar oscillations are consistent with the previous calculations. 相似文献
5.
Numerical Algorithms - Our focus in this paper is on introducing an iterative scheme based on the generalized implicit method and viscosity approximation method with Meir-Keeler contraction for... 相似文献
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A Gurtu P K Malhotra I S Mittra P M Sood SC Gupta VK Gupta GL Kaul LK Mangotra Y Prakash NK Rao ML Sharma 《Pramana》1974,3(5):311-322
This is a continuation of our earlier investigation (Gurtuet al 1974Phys. Lett. 50 B 391) on multiparticle production in proton-nucleus collisions based on an exposure of emulsion stack to 200 GeV/c beam at the NAL. It is found that the ratioR em = 〈n s〉/〈n ch〉, where 〈n ch〉 is the charged particle multiplicity in pp-collisions, increases slowly from about 1 at 10 GeV/c to 1·6 at 68 GeV/c and attains a constant value of 1·71 ± 0·04 in the region 200 to 8000 GeV/c. Furthermore,R em = 1·71 implies an effectiveA-dependence ofR A =A 0.18,i.e., a very weak dependence. Predictions ofR em on various models are discussed and compared with the emulsion data. Data seem to favour models of hadron-nucleon collisions in which production of particles takes place through adouble step mechanism,e.g., diffractive excitation, hydrodynamical and energy flux cascade as opposed to models which envisage instantaneous production. 相似文献
9.
The dielectric constant and the electrical conductivity of the transparent glasses in the composition 3Na2O-7B2O3 (NBO) were investigated in the 100 Hz–10 MHz frequency range at various temperatures. The activation energy associated with
the electrical relaxation determined from the electric modulus spectra was found to be 0.76 ± 0.02 eV, close to that (0.74 ± 0.02 eV)
obtained from DC conductivity studies. The frequency-dependent electrical conductivity was analyzed using Jonscher’s power
law. Temperature-dependent behavior of the frequency exponent (n) suggested that the correlated-barrier hopping model was the most appropriate to rationalize the electrical transport phenomenon
in NBO glasses. 相似文献
10.
Satendra K Vaish 《Journal of Mathematical Analysis and Applications》1984,101(1):23-29
In this paper we obtain a growth relation for entire functions of qth order with respect to the distribution of its zeros. We also derive certain relations between the qth convergence exponents of two or more entire functions. The most striking result of the paper is: If f(z) has at least one zero, then , where n(r) is the number of zeros of f(z) in and . 相似文献