This study presents the effectiveness of the rebar ratio and the arrangement of reinforced concrete (RC) structures on the structural behavior of nuclear buildings under aircraft impact using a finite element (FE) approach. A simplified model of a fictitious nuclear building using RC structures was fully modeled. The aircraft model of a Boeing 767-400 was used for impact simulation and was developed and verified with a conventional impact force–time history curve. The IRIS Punching test was used to validate the damage prediction capabilities of the RC wall under impact loading. With regard to the different rebar ratios and rebar arrangements of a nuclear RC building, the structural behavior of a building under aircraft impact was investigated. The structural behavior investigated included plastic deformation, displacement, energy dissipation, perforation/penetration depth and scabbing area. The results showed that the rebar ratio has a significant effect on withstanding aircraft impact and reducing local damage. With four layers of rebar, the RC wall absorbed and dissipated the impact energy more than once with only two layers of rebar for the same rebar ratio.

This chapter describes sample preparation for gel-based proteomics, capillary electrophoresis and capillary electrophoresis coupled with mass spectrometry. Two dimensional gel electrophoresis (2D-PAGE) remains one of the most commonly used separation techniques for complex protein mixtures. Stringent and consistent sample preparation is essential for reproducible and high quality 2D-PAGE analysis of complex protein mixtures. The goal of this step is to produce homogeneous sample, free from contaminants and with consistent chemical parameters (pH, salt concentration etc) that will allow the user to generate reproducible results. Capillary electrophoresis (CE) separates analytes from a complex mixture with high resolution based on differential migration through a liquid filled capillary in a strong electric field. CE is easily automated and lends itself well to microfluidic device technology. The evolution of these microfluidic devices allows the potential for the hyphenation of CE to other separation and identification methods like gel chromatography, high performance liquid chromatography (HPLC) and mass spectrometry.

2-DE remains one of the most commonly used separation techniques for complex protein mixtures. This article describes a new approach to 2-DE sample assessment using SDS capillary gel electrophoresis (in Beckman Coulter sieving medium) combined with multi-pixel detection. The performance of this platform was investigated using protein samples prepared for 2-DE. The capability to characterize 2-DE sample was tested and the results show that the repeatability of peak migration time and intensity are better than 2% RSD. The system gives good resolution, accurate molecular mass assignment, as well as absolute and relative quantification of proteins. Notably, this study also demonstrates the use of this platform to screen the quality of simple and complex 2-DE samples. Implementation of this technique in the proteomics workflow will not only improve the success rate of 2-DE, but will also enable sample verification before 2-DE and allow the relative quantification of proteins. The validation of differential protein expression is also demonstrated using the combined information of relative molecular mass and relative quantification. It is the first time that a rapid and visual evaluation method is reported for the quality assessment of 2-DE samples.

To realise effective size separations of nucleic acid fragments using CE, gel-based matrices are commonly employed. The separation of label-free dsDNA ladders and plasmid fragments in an uncross-linked semi-dilute poly (ethylene) oxide solution using multi-pixel UV detection at 254 nm is reported. Improvements in the sensitivity of UV detection of dsDNA using signal averaging over multiple pixels is demonstrated. Separations performed using a diode array detector also allow the progress of the separation to be monitored as a function of time. Several polymers were examined including methyl cellulose, linear polyacrylamide, hydroxy (propyl) methylcellulose and polyethylene oxide. Operations parameters investigated included UV transparency, self-coating capacity and separation efficiency. The results show complete resolution of all fragments under a range of conditions, including short separation lengths.

Capillary electrophoresis has been used in the analysis of peptides for decades, however traditional methods show excessive variability due to composition and sequence of the peptide, and variation in the interaction of the peptide with the separation medium. Multi-pixel detection along with the associated data analysis software improves reproducibility and sensitivity beyond current methods using UV absorption detection. The reproducibility of the data and the sensitivity of this 'no-label' multi-pixel detection approach are investigated using a mixture of known peptides. In the near future this will enable peptide mass finger printing based on the ability to assign molecular weight values to the peptides separated by charge.

The major packaging signal of human immunodeficiency virus type 1 (HIV-1) RNA has been localised to the region 3′ to the major splice donor within the leader sequence. Secondary structural studies for this region of the HIV-1 genome have shown the existence of a stem-loop structure capped by a purine-rich tetraloop. Extensive mapping data presented here lead to the complete characterisation of the structure of the stem-loop, including a new purine-rich internal loop in the lower part of the structure and the previously established GGAG tetraloop at its tip. Biochemical analysis reveals that both internal loop and tetraloop are primary sites for interaction with Gag polyprotein, and that binding of Gag protein leads to a conformational change which alters the RNA structure. NMR spectroscopy has been used to determine the three-dimensional structure of this complete stem-loop structure. The structural analysis reveals a significant difference between the apical part of the stem-loop structure, which adopts a well-defined conformation, and the purine-rich internal loop, which is instead very flexible. In contrast to what is generally observed for internal loop structures in RNA, this region of the encapsidation signal adopts a structure lacking stable interstrand interactions capable of stabilising a unique conformation. We suggest that the stem-loop structure represents a nucleation site for Gag protein binding, and that the protein exploits the flexibility of the internal loop to initiate the unwinding of the structure with successive addition of Gag molecules interacting with the RNA and each other through conserved I (interaction) domains.