microRNAs (miRNAs) are small, functional, non-coding RNAs. miRNAs are transcribed as long primary transcripts (primary precursors) that are processed to the approximately 75 nt precursors (pre-miRNAs) by the nuclear enzyme Drosha. The approximately 22 nt mature miRNA is processed from the pre-miRNA by the RNase III Dicer. The vast majority of published studies to date have used northern blotting to detect the expression of miRNAs. We describe here a sensitive, high throughput, real-time PCR assay to monitor the expression of miRNA precursors. Gene-specific primers and reverse transcriptase were used to convert the primary precursors and pre-miRNAs to cDNA. The expression of 23 miRNA precursors in six human cancer cell lines was assayed using the PCR assay. The miRNA precursors accumulated to different levels when compared with each other or when a single precursor is compared in the various cell lines. The precursor expression profile of three miRNAs determined by the PCR assay was identical to the mature miRNA expression profile determined by northern blotting. We propose that the PCR assay may be scaled up to include all of the 150+ known human miRNA genes and can easily be adaptable to other organisms such as plants, Caenorhabditis elegans and Drosophila.
Apparent molar volumes V Φ,S and viscosity B-coefficients for D-(+)-glucose, D-(+)-galactose, D-(+)-xylose, and D-(-)-ribose in aqueous amino acid (glycine or L-alanine) solutions have been determined respectively from density and viscosity measurements at 298.15 K. Infinite-dilution apparent molar volumes for the saccharides V Φ,S 0 in aqueous glycine or L-alanine solutions have been evaluated, together with the standard transfer volumes ∆ t V Φ,S 0 of the saccharides from water to aqueous amino acid solutions. It is shown that values of transfer volumes and viscosity B-coefficients are positive and increase with increasing amino acid contents. Volumetric parameters indicating the interactions of saccharides with amino acids in water have been obtained from the transfer volumes of the saccharides. The interactions between saccharides and amino acids are discussed in terms of the structural interaction model and the stereo structure of monosaccharide molecules.
Pseudomonas putida KT2442 could accumulate medium-chain-length poly(hydroxyalkanoate)s (PHA) consisting of 3-hydroxyhexanoate, 3-hydroxyoctanoate, 3-hydroxydecanoate, and 3-hydroxydodecanoate from a wide range of carbon sources. In this study, the PHA synthase pha operon (phaC1-phaZ-phaC2) was knocked out and the vgb gene encoding vitreoscilla hemoglobin protein (VHb), which could enhance oxygen uptake rate especially at low oxygen concentration, was integrated into the P. putida KT2442 genome to replace the deleted fragment. The resulting mutant P. putida KTOY01 or gene-replaced mutant KTOY02 was used as the host to study PHA synthase properties and PHA production. Different PHA polymerase (PhaC) genes, phaC(Re) from Rastonia eutropha H16, phaC(Ac) from Aeromonas cavie, and phaC2(Ps) from Pseudomonas stutzeri 1317, were expressed in the mutant strains to test the PhaC enzyme substrate specificity. The result showed P. putida KTOY01 or KTOY02 could provide not only mcl PHA monomers but also 3-hydroxybutyrate from fatty acids, which may allow the production of copolyesters poly(3HB-co-mcl 3HA). Plasmid pCJY10 containing phaC2(Ps), phbA, and phbB genes encoding PHA polymerase, beta-ketothiolase, and acetoacetyl-CoA reductase, respectively, were transformed into P. putida KTOY01 and KTOY02. Shake-flask culture showed P. putida KTOY01 or KTOY02 (pCJY10) could accumulate poly(3HB-co-mcl 3HA) from glucose. The above result showed pha operon knockout mutant of P. putida KT2442 was a very useful host of great potential not only for studying PhaC synthase, but also for microbial production of copolyesters poly(3HB-co-mcl 3HA), which is very difficult to obtain.
Here, a complete set of recombinant fission yeast strains that coexpress each of the 57 human cytochrome P450 (CYP) enzymes together with their natural human electron transfer partner(s) was cloned. This strain collection was tested with two luminogenic probe substrates, and 31 human CYPs (including the orphan enzymes CYP2A7, CYP4A22 and CYP20A1) were found to metabolize at least one of these. Since other substrates are known for the remaining enzymes, all human CYPs are now shown to be active. Interestingly, CYP5A1 was found for the first time to work on a substrate other than prostaglandin H2, and, moreover, to catalyze an aliphatic hydroxylation reaction that consumes molecular oxygen. Also, the ability of CYP11A1 to catalyze an aryl hydroxylation is another unexpected result.
To cite this article: Daqi Zhu , Qian Liu & Zhen Hu (2011) Fault-tolerant control algorithm of the manned submarine with multi-thruster based on quantum-behaved particle swarm optimisationA thruster reconfiguration control approach of manned submarine with 7000 m operation depth based on quantum-behaved particle swarm optimisation (QPSO) is presented in this article. The manned submarine has eight thrusters. When thruster faults happen, the corresponding weight matrix is updated to restrict the usage of the faulty thruster. But the solution with this method may become unfeasible (exceed the rated valve of the thruster) and cannot be directly applied to the thrusters. In order to complete an appropriate control law reconfiguration, a novel control reallocation method based on QPSO is proposed. Not only is the solution obtained by the approach of QPSO limited in the whole feasible space, but also the control error of the fault-tolerant control is very small. Eight dimensions of the particles are used in this article, and each particle represents the components of the control vector, it searches in the range of the restricted factor value to make sure that all the reconfiguration control solutions are feasible. Compared to the weighted pseudo-inverse method, the error of the obtained control vector with the QPSO is very small. Finally, simulation examples of multi-uncertain faults are given to illustrate the advantages of the proposed method.
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