No abstract

Microstereolithography (MSL) is technology of fabrication of three-dimensional (3D) components by using layer-by-layer photopolymerization. Typical design goals of MSL system are: small features, high resolution, high speed of fabrication, and large overall size of component. This paper focuses on design and development of such a system to meet these optomechatronic requirements. We first analyze various optical scanning schemes used for MSL systems along with the proposed scheme via optical simulations and experiments. Next, selection criteria for various subsystems are laid down and appropriate design decisions for the proposed system are made. Further, mechanical design of the scanning mechanism is carried out to meet requirements of high speed and resolution. Finally, system integration and investigation in process parameters is carried out and fabrication of large microcomponent with high resolution is demonstrated. The proposed system would be useful for fabrication of multiple/large microcomponents with high production rate in various applications.

In Escherischia coli, AcrB is an inner membrane transporter that cooperates with a membrane fusionprotein, AcrA and an outer membrane channel TolC, to export a wide variety of drugs directly out of the cell, bypassing the periplasm. By overproducing such membrane transport proteins, E. coli and other human pathogenic bacteria are able to achieve multidrug resistance. In this paper, we have reported the virtual screening of five in silico small molecule libraries against the substrate recognition site situated in the porter domain of binding protomer of AcrB using tools of Schröding-er suite, which resulted in six potential hits. All these compounds favored hydrogen bonding interactions with mainly polar and aromatic residues such as Ser134, Phe178 and Ile671. From the observed results these ligands are suggested to be potent candidates for inhibiting AcrB. Docking simulations were also carried out with several known substrates and inhibitors in order to study their interactions with the binding site.