1,721,021 research outputs found
RNA-conjugated template-switching RT-PCR method for generating an Escherichia coli cDNA library for small RNAs
No full textThe cDNA conversion of RNA molecules is a prerequisite for their analysis. In the case of prokaryotic RNAs, cDNA conversion is difficult due to a lack of the long poly(A) tails that are found in eukaryotic mRNAs. The full cDNAs for eukaryotic mRNAs can be amplified by the reverse transcription polymerase chain reaction (RT-PCR) using the template-switching method together with an oligo(dT) primer. To amplify the full cDNAs for prokaryotic RNAs, we modified the template-switching RT-PCR method by adopting an RNA linker at the 3' end of the target RNAs. Using this method, which we named as RNA-conjugated template-switching RT-PCR (RC/TS RT-PCR), we constructed a cDNA library for small RNAs from cold-shock-treated Escherichia coli cells. To confirm that the cDNAs were amplified by RC/TS RT-PCR without a loss of sequence information, clones carrying the 6S RNA sequence were analyzed from the cDNA library for small RNAs ranging from 130 to 350 nt. We found that the 6S RNA sequences were fully converted into the corresponding cDNAs, confirming that ROTS RT-PCR is a useful method for constructing a cDNA library for small RNAs in E. coli. This method can be also used to construct a cDNA library for non-poly(A)-containing RNAs from eukaryotic cells. (C) 2005 Elsevier B.V All rights reserved.Brain Korea 2
A two-dimensional model for polydisperse particles on the effective migration rate of the electrostatic precipitator with wider plate-spacing
No full textTHE CHI-SQUARE APPROXIMATION APPROACH TO RANKING AND SELECTION PROCEDURES UNDER TYPE-II CENSORING
No full textIn this paper we consider the problem of ranking and selection with respect to the largest scale parameter of gamma populations under Type-II censoring. Shape parameters of the gamma populations are assumed to be known and equal. Under the assumption of common sample size and censoring number, ranking and selection procedures are presented based on the total time on test (TTOT) statistic. Since the exact distribution of the TTOT statistic is not known in general, a two-moment chi-square approximation is used to derive expressions for the probability of correct selection and its infimum for each procedure. Monte Carlo studies are conducted to obtain coefficients for the chi-square approximation. Performances of the proposed approximate procedures are compared with those of existing ones for various legitimate cases
SWITCHED OPTIMAL PREDICTIVE CURRENT CONTROL TECHNIQUE FOR IMPROVED QUANTUM BOOST SRC
No full textA dynamic model and a switched optimal predictive current control technique for an improved quantum boost series resonant convertor (SRC) are proposed to overcome the inherent disadvantages of the quantum SRC. With this technique, the current ripple and the overshoot can be minimised and the buck-boost operation can also be achieved
Symbol-by-symbol based adaptive interference canceller for asynchronous DS/CDMA systems in multipath fading channels
No full textThe authors propose a new interference cancellation scheme called the symbol-by-symbol based adaptive interference canceller (SA1C), which adaptively estimates and removes both multiple access interference (MAI) and intersymbol interference (ISI) al the output of the Rake receiver. The SAIC is considerably simpler to implement than existing techniques; computer simulation results demonstrate that it can perform much better than conventional Rake receivers
A New Controller Design Method for Buck-Type Switching Regulator Satisfying the Time Domain Specifications
No full textProcessing of M1 RNA at the 3 end protects its primary transcript from degradation
No full textM1 RNA, the catalytic subunit of Escherichia coli RNase P, is an essential ribozyme that processes the 5' leader sequence of precursor tRNAs. It is generated by the removal of 36 nucleotides from the 3' end of the primary rnpB transcript (pM1 RNA), but the biological significance of this reaction in bacterial metabolism remains obscure. In this study, we constructed and analyzed bacterial strains carrying mutations in the rne-dependent site of their rnpB genes, showing that the 3' processing of M1 RNA is essential for cell viability. Furthermore, we demonstrate that pM1 RNA can undergo not only 3' processing but also poly(A)-dependent degradation. Therefore, our results suggest that the 3' processing of M1 RNA provides a functional mechanism for the protection of its primary transcript against degradation
Modeling and Inproved Current Control of Series Resonant Converter with Non-Periodic Integral Cycle Mode
No full textOptical characteristics of photo-curable methacryl-oligosiloxane nano hybrid thick films
No full textIn this paper, we report the fabrication the methacryl-oligosiloxane nano hybrid films from 3-(trimethoxysilyl)propyl methacrylate (MPTS) and diphenylsilanediol (DPSD), and the investigation of the tuneability of the optical characteristics of the films through the compositional change. The viscosity of the methacryl-oligosiloxane nano hybrid resin was altered at 10(2) intervals by the compositional modification without any drastic changes in the reaction parameters, and thickness-controlled (from 11 to 150 mu m) and uniformly coated (less than 1 nm root-mean-square roughness) films were obtained through a single coating step. The refractive indices were tunable from 1.506 to 1.543, depending on composition. On the other hand, the thermo-optic coefficients remained constant (-2 x 10(-4)/degrees C), independent of composition. Also, we demonstrated a thick (170 mu m) photo pattern with a high aspect ratio (3:1). Methacryl-oligosiloxane nano hybrid materials can be promising candidates for the optical applications due to easy and wide tuneability of their optical parameters.This work was supported by the Sol-Gel Innovation Project(SOLIP)of the Ministry of Commerce, Industry and Energy of Kore
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