Vectorial characterization of surface wave via one-dimensional photonic-atomic structure.

Quantitative assessment of polarization properties of waves opens up the way for effective exploitation of them in many amazing applications. Tamm surface waves (TSW) that propagate on the interface of periodic dielectric media are proposed for many applications in numerous reports. The polarization state of TSW is not simply intuitive and would not be extracted from reflection spectra. Here considering orientation sensitive nature of the interaction between polarized electromagnetic wave and atom, we try to quantitatively characterize the polarization state of TSWs, excited on the surface of the 1D photonic crystal. To do this we performed direct contact between TSW and rubidium atomic gas by fabrication of a one-dimensional photonic crystal-atomic vapor cell and applied a moderate external magnetic field to create geometrical meaning and a sense of directionality to dark lines in reflection intensity. Our experimental results indicate that transition lines in the reflection spectrum of our hybrid system modify dependent on the orientation of the applied magnetic field and the transverse spin of TSW. We have used these changes to redefine the geometry of Voigt and Faraday for evanescent waves, especially Tamm surface waves. In the end, we performed simple mathematical operations on absorption spectra and extract the ratio of longitudinal and transverse electric field components of the polarization vector of TSW equal to [Formula: see text].

Bloch surface wave-atom coupling in one-dimensional photonic crystal structure.

Considering efforts for hot atomic vapor-nanophotonics integration as a new paradigm in quantum optics, in this paper, we introduce 1D photonic crystal-Rb vapor cell as structure with miniaturized interaction volume. The Bloch surface wave (BSW) excited on surface of a photonic crystal as electromagnetic hosting photonic mode, and altered the optical response of Rb atoms in the vicinity of surface. Coupling of atomic states with BSW confined modes would lead to quantum interference effects and results in nonlinearities in resonant coupling of atoms with BSW. We show Bloch surface wave induced transparency is highly stable under a change of incidence angle. Our results show slight changes in transitions detuning's due to nonlinear interactions like the Casimire-Polder effect under change of localized density of optical states.

Block ionomer micellar nanoparticles from double hydrophilic copolymers, classifications and promises for delivery of cancer chemotherapeutics.

A class of double hydrophilic copolymers comprising ionic and nonionic water-soluble blocks, which are also called block ionomers, represent an interesting type of polymer assembly forming stable, homogeneous core-corona dispersions. They exhibit the solution behavior of normal polyelectrolytes, whereas assembly into micelle, vesicle or disk morphology happens by an external stimulus (pH, temperature or ionic strength) or complex formation with metal ions, ionic surfactants, polyelectrolytes, etc. Temperature, pH, redox or salt sensitivity affords a unique opportunity to control the triggered release of payloads accommodated through electrostatic interaction, coordination or chemical conjugation. Moreover, the non-ionic block provides the surface passivation, prolongation of the blood circulation and tumor accumulation, supporting targeted delivery of chemotherapeutic agents based on pathophysiology of tumor microenvironment. Potentiation of antitumor activity, sensitization of the resistant tumors, increased tolerated dose and translation into clinical practice are among their most intriguing characteristics. Their high functionality has been suggested for co-delivery of multiple agents for reversal of chemo-resistance as well as simultaneous therapy and diagnostics. Nevertheless, some stability concerns may be raised due to the polymer disassembly beyond a critical concentration of pH, salt and polyion concentration that can be modulated by introducing crosslinks between the polymer chains (Nano-networks).

Preparation and assessment of chitosan-coated superparamagnetic Fe3O4 nanoparticles for controlled delivery of methotrexate.

In this study, Fe3O4 superparamagnetic nanoparticles were synthesized and stabilized by chitosan. Then the nanoparticles were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy (TEM). Particle size distribution and Zeta potential of the particles also was assessed using Malvern Zetasizer. The paramagnetic behaviors of the uncoated and chitosan coated nanoparticles were measured using vibrating scanning magnetometry Particles morphology and size ranges of uncoated iron oxide nanoparticles were evaluated by TEM, showing uniform and narrow size distribution about 10 nm. After coating nanoparticles with chitosan and loading of methotrexate (MTX), the change in size was assessed using Zetasizer. Considerable increase in size was observed following the coating of the particles with chitosan and loading with MTX (the average size was 152 nm). Paramagnetic properties of the uncoated and chitosan-coated particles were assessed showing significant decrease in paramagnetic behavior after coating with chitosan, but it was enough to respond to the magnetic field. Finally loading efficiency, release rate and cytotoxicity of MTX were assessed indicating slow release behavior with the same levels of cell toxicity in SK-BR-3 cell lines, suggesting this formulation as a good candidate for the controlled delivery of MTX.