ABSTRACT
The novel poly(cytosine)-modified glassy carbon electrode-based electrochemical sensor was fabricated potentiodynamically for the detection of Guanine (G) in clinical and biological samples. The surface of the electrode was successfully activated by electropolymerization, and about a 7.5-fold current improvement due to modification was achieved. From the analysis of the dependence of peak current and peak potential on a scan rate, a higher R 2 for the peak current on the square root of scan rate (R 2 = 0.999) than the dependence of peak current on scan rate (R 2 = 0.982) indicated that the oxidation of G at poly(cytosine)/GCE was predominantly diffusion controlled. The oxidative peak response of the electrode revealed a high linear range of G concentration (0.1-200 µM) under optimized conditions. The detection limit and limit of quantification were 6.10 and 20.13 nM, respectively, associated with the %RSD of under 1%. The validation of the developed electrochemical sensor for the determination of G was investigated by analyzing human urine DNA and serum samples with spike recovery results in the range of 98.20-103.70% with the interferent recovery percentage in the range of 97.86-103.10% containing 50-300% of potential interferents. The newly designed sensor demonstrated the highest level of performance for the G detection in real samples.
ABSTRACT
Existing literatures on combined effects of blast-impact loadings on steel-concrete composite beams are limited. In this study, behavior of steel-concrete composite beam subjected to combined blast-impact loading was investigated using LS-DYNA nonlinear FEA software program. The accuracy and reliability of developed FEA model was validated using experimental data reported in literature. Parametric studies were performed on impacting speed, concrete strength, various characteristics of H-structural steel, yield strength of studs and steel rebars to get insight into performance of composite beam subjected to combined blast impact loading. FEA results revealed that increase in specified cylindrical compressive strength of concrete, yield stress, flange and web thicknesses of H-type structural steel beam significantly improved dynamic response of a steel-concrete composite beam under combined impact-blast load case whereas yield stress of studs, and reinforcement steel bars showed insignificant contribution. Moreover, increasing impactor's initial velocity significantly affects dynamic response of a SCC beam under combined blast-impact loading.
ABSTRACT
The failure of column, which is a critical compressive structural member of a building, may lead to devastating progressive collapses. The present numerical study involves investigation on the performance of as-built and strengthened RC columns using 0°/90° CFRP layers under blast loading. A nonlinear FEA program, LS-DYNA was employed to study the RC columns response when subjected to blast loading. Blast field test data from recent literatures was employed for validation and further parametric studies. Variables considered were different charge masses, height of bursts, concrete compressive strengths, standoff distances, tie spacings, transverse reinforcement steel detail schemes, and 0°/90° CFRP layers. It was revealed that scaled distance parameters had a significant effect on the behaviour of RC columns under blast loading. Compared to as-built column, 0°/90° CFRP strengthened RC columns displayed excellent blast resistance. Transverse reinforcement steel details had a significant effect on lateral displacement response and failure modes of RC columns. Compared to conventionally-detailed columns, seismically-detailed columns and transverse reinforcement steel bars accompanied with square-diamond shaped ties exhibited enormous blast resistance capacity.
ABSTRACT
Plant viruses affect crop production both quantitatively and qualitatively. The viral genome consists of either DNA or RNA. However, most plant viruses are positive single-strand RNA viruses. MicroRNAs are involved in gene regulation and affect development as well as host-virus interaction. They are non-coding short with 20-24 nucleotides long capable of regulating gene expression. The miRNA gene is transcribed by RNA polymerase II to form pri-miRNA which will later cleaved by Dicer-like 1 to produce pre-miRNA with the help of HYPONASTIC LEAVES1 and SERRATE which finally methylated and exported via nucleopore with the help of HASTY. The outcome of plant virus interaction depends on the effectiveness of host defense and the ability of a virus counter-defense mechanism. In plants, miRNAs are involved in the repression of gene expression through transcript cleavage. On the other hand, viruses use viral suppressors of RNA silencing (VSRs) which affect RISC assembly and subsequent mRNA degradation. Passenger strands, miRNA*, have a significant biological function in plant defense response as well as plant development.
