Dual expression recombinase based (DERB) single vector system for high throughput screening and verification of protein interactions in living cells

Identification of novel protein interactions and their mediators is fundamental in understanding cellular processes and is necessary for protein-targeted therapy. Evidently high throughput formatting of these applications in living cells would be beneficial, however no adequate system exists. We present a novel platform technology for the high throughput screening and verification of protein interactions in living cells. The platform's series of Dual Expression Recombinase Based (DERB) destiny vectors individually encode two sets of recombinase recognizable sequences for inserting the protein open reading frame (ORF) of interest, two sets of promoters and reporter tags in frame with the ORFs for detecting interactions. Introduction into living cells (prokaryotic and eukaryotic) enables the detection of protein interactions by fluorescence resonance energy transfer (FRET) or bimolecular fluorescence complementation (BiFC). The DERB platform shows advantages over current commercialized systems by DERB vectors validated through proof-of-principle experiments and the identification of an unknown interaction

On the formal verification of ATM switches

Because of the difficulty of adequately simulating large digital designs, there has been a surge of interest in formal verification, in which a mathematical model of the design is proved to satisfy a precise specification. Model Checking and Equivalence Checking , which have the advantage of automatic verification, are two main formal verification techniques that people are working on. The main problem of model checking and sequential equivalence checking is the state space explosion. Another drawback of model checking is lack of methods on establishing an environment and expressing a property. In this thesis, we propose Property Division techniques which avoid the state space explosion problem by deducing a property from several sub-properties. A number of methods on establishing an environment and expressing a property are illustrated. Although ATM hardware is hard to design due to its high speed and various features. the applications of model checking and equivalence checking on ATM hardware verification are few. In this thesis, Fairisle ATM switch fabric, Fairisle ATM null port controller, Input FIFO of RCMP-800 and Concentrator of Knockout ATM switch are developed. With the techniques we propose, all these ATM hardware designs are formally verified in the formal verification tools called Verification Interacting with Synthesis ( VIS

Dependency of image quality on system configuration parameters in a stationary digital breast tomosynthesis system

Purpose: In principle, a stationary digital breast tomosynthesis (s-DBT) system has better image quality when compared to continuous motion DBT systems due to zero motion blur of the source. The authors have developed a s-DBT system by using a linear carbon nanotube x-ray source array. The purpose of the current study was to quantitatively evaluate the performance of the s-DBT system;and investigate the dependence of imaging quality on the system configuration parameters. Methods: Physical phantoms were used to assess the image quality of each configuration including inplane resolution as measured by the modulation transfer function (MTF), inplane contrast as measured by the signal difference to noise ratio (SdNR), and depth resolution as measured by the z-axis artifact spread function. Five parameters were varied to create five groups of configurations: (1) total angular span; (2) total number of projection images; (3) distribution of exposure (mAs) across the projection images; (4) entrance dose; (5) detector pixel size. Results: It was found that the z-axis depth resolution increased with the total angular span but was insensitive to the number of projection images, mAs distribution, entrance dose, and detector pixel size. The SdNR was not affected by the angular span or the number of projection images. A decrease in SdNR was observed when the mAs was not evenly distributed across the projection images. As expected, the SdNR increased with entrance dose and when larger pixel sizes were used. For a given detector pixel size, the inplane resolution was found to be insensitive to the total angular span, number of projection images, mAs distribution, and entrance dose. A 25% increase in the MTF was observed when the detector was operating in full resolution mode (70 μm pixel size) compared to 2 × 2 binned mode (140 μm pixel size). Conclusions: The results suggest that the optimal imaging configuration for a s-DBT system is a large angular span, an intermittent number of projection views, and a uniform mAs distribution over all views. With the detector operating at full resolution, a stationary DBT system can achieve an inplane resolution of 5.1 cycles per mm, which is significantly better than continuous motion DBT systems