When Plasmonic Colloids Meet Optical Vortices -- A Brief Review

Structured light has emerged as an important tool to interrogate and manipulate matter at micron and sub-micron scale. One form of structured light is an optical vortex beam. The helical wavefront of these vortices carry orbital angular momentum which can be transferred to a Brownian colloid. When the colloid is made of metallic nanostructures, such as silver and gold, resonant optical effects play a vital role, and the interaction leads to complex dynamics and assembly. This brief review aims to discuss some recent work on trapping plasmonic colloids with optical vortices and their lattices. The role of optical scattering and absorption has important implications on the underlying forces and torques, which is specifically enunciated. The effect of spin and orbital angular momentum in an optical vortex can lead to spin-orbit coupling dynamics, and these effects are highlighted with examples from the literature. In addition to assembly and dynamics, enhanced Brownian motion of plasmonic colloids under the influence of a vortex-lattice is discussed. The pedagogical aspects to understand the interaction between optical vortex and plasmonic colloids is emphasized.Comment: Comments welcome. Invited review article (150 references). Submitted to Indian Journal of Physics and Applied Physics (IJPAP) - special issue on nanophotonic

Differential genotypical expression of a NEDD9 in normal and tumor tissues: a possible pharmacological target

Background: Neural precursor cell expressed developmentally down regulated-9 (NEDD9) is a scaffolding metastatic marker protein in multiple cancer types. Generally, the expression occurs during the embryonic development and depletes in adults. Expression of NEDD9 in adults leads to the progression of tumor which is sufficient for the cellular invasion. Elevated behavior of the gene mediates metastatic movement which includes protease dependent neovessel formation, invasion and migration of tumor cells from the site of origin to the distant tissues.Methods: The current study involves the screening and elucidation of differential expression of NEDD9 in normal and tumor subtypes with various tissues of mice by immunohistochemistry.Results: The validating approaches in the study, low expression of NEDD9 was observed in the normal tissues and predominance in the tumor subsets.Conclusions: The experimental analysis proven that NEDD9 expression is merely associated with tumor progression and the molecular mechanism of NEDD9 is restricted in the establishment of metastatic cascade. NEDD9 association in tumor prognosis which helps in the emergence of diagnostic and therapeutic approaches