72 research outputs found
Modeling of PCI with SystemVerilog
Deep submicron semiconductor technology has enabled system-level IC design
complexity to exceed millions of gates. This presents a major design and verification
challenge that intensifies the demand for system-level design languages. A major impact in solving this problem has been the development and standardization of an Hardware Description and Verification Language like SystemVerilog which caters all the needs for design as well as verification.Master of Science (Integrated Circuit Design
Ion-Implant Isolation of InP/InGaAs HBTs
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Differential Selection and Mutation Shape Codon Usage of Escherichia coli ssDNA and dsDNA Bacteriophages
Bacteriophages (hereafter referred as phages) can translate their mRNAs efficiently by maximizing the use of codons decoded by the most abundant tRNAs of their bacterial hosts. Translation efficiency directly influences phage fitness and evolution. Reengineered phages find application in controlling their host population in both health and industry. The objective of this thesis work is to examine the factors shaping codon choices of single stranded DNA (ssDNA) and double stranded DNA (dsDNA) Escherichia coli phages. In chapter two, we employed two indices, rRSCU (correlation in relative synonymous codon usage between phages and their hosts) and CAI (codon adaptation index) to measure codon adaptation in phages. None of the analyzed ssDNA phages encode tRNAs while some dsDNA phages encode their own tRNAs. Both rRSCU and CAI are negatively correlated with number of tRNA genes encoded by these dsDNA phages. We observed significantly greater rRSCU for dsDNA phages (without tRNAs) than ssDNA phages. In addition, we propose that ssDNA phages have evolved a novel codon adaptation strategy to overcome the disruptive effect of their high C→T mutation rates in codon adaptation with host. In chapter three, we formulated an index phi to measure selection by host translation machinery and to present explicit linear and nonlinear models to characterize the effect of C→T mutation and host-tRNA-mediated selection on phage codon usage. The effect of selection (phi) on codon usage is detectable in most dsDNA and ssDNA phage species. C→T mutations also interfere with nonsynonymous substitutions at second codon positions, especially in ssDNA phages. Strand asymmetry along with the accompanying local variation in mutation bias can significantly affect codon adaptation in both dsDNA and ssDNA phages
Mechanism of protection of rat hepatocytes from acetaminophen-induced cellular damage by ethanol extract of Aerva lanata
The aim of this study is to evaluate the protective effect of ethanol extract of Aerva lanata (EEAL) in preventing acetaminophen induced liver toxicity. EEAL was prepared and its hepatoprotective effect was studied in both isolated primary hepatocytes in vitro and in Sprague Dawley rats in vivo. For in vivo studies, the animals were grouped as Group I – Control; Group II – ACN (2 g/kg b.w.); Group III – EEAL (50 mg/kg b.w.) + ACN (2 g/kg b.w.), Group IV – EEAL (100 mg/kg b.w.) + ACN (2 g/kg b.w.). Extracellular activities of the enzymes liver aminotransferease (GOT, GPT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in isolated hepatocytes and rat plasma were studied colorimetrically. Expression of GST, Nrf2, COX 1 & COX2 genes in rat liver were evaluated by RT-PCR. The results showed that ACN induced down-regulation of Nrf2 and upregulation of GST gene expression, which were modulated by EEAL treatment. GOT, GPT, ALP and LDH levels were found to be lowered in both hepatocyte culture media and plasma following EEAL treatment. In addition, the medium GOT and GPT levels were diminished following EEAL treatment only. Moreover, only ALP and LDH in serum appeared to be at normal level following EEAL treatment, whereas GOT and GPT showed levels lower than control. ACN treatment increased the expression of pro-inflammatory COX 1 and COX 2 genes and the levels of these genes were reduced by EEAL treatment. EEAL pre-treated rats exposed to ACN were found to retain normal hepatic structure compared to ACN alone treated rats. From these results it can be concluded that ethanol extract of A. lanata possesses both anti-inflammatory and hepatoprotective activity
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