Photostimulated Extended Nitric Oxide (NO) Release from Water-Soluble Block Copolymer to Enhance Antibacterial Activity.

-Nitrosamines are well established motifs to release nitric oxide (NO) under photoirradiation. Herein, a series of amphiphilic -nitrosamine-based block copolymers () are developed to attain controlled NO release under photoirradiation (365 nm, 3.71 mW/cm).

Aqueous spice extracts as alternative antimycotics to control highly drug resistant extensive biofilm forming clinical isolates of Candida albicans.

Candida albicans form biofilm by associating with biotic and abiotic surfaces. Biofilm formation by C. albicans is relevant and significant as the organisms residing within, gain resistance to conventional antimycotics and are therefore difficult to treat.

Polymicrobial Biofilm Dynamics of Multidrug-Resistant and Ampicillin-Resistant and Antimicrobial Inhibition by Aqueous Garlic Extract.

The polymicrobial biofilm of with exhibits a dynamic interspecies interaction and is refractory to conventional antimicrobials. In this study, a high biofilm-forming multidrug-resistant strain of overcomes inhibition by in a 24 h coculture. However, following treatment with whole Aqueous Garlic Extract (AGE), these individual biofilms of multidrug-resistant M-207 and Ampicillin-resistant ATCC 39936 and their polymicrobial biofilm were prevented, as evidenced by biochemical and structural characterization.

Candida albicans biofilm formation and growth optimization for functional studies using response surface methodology.

Aim: Optimization of Candida albicans growth and biofilm formation is essential for understanding the recalcitrance of this pathogen to advance functional analysis on hospital tools and material surfaces. Optimization and quantification of biofilm have always been a challenge using the conventional one variable at a time (OVAT) method. The present study uses central composite design-based response surface methodology for optimization of conditions to induce growth and biofilm formation in Candida albicans on polystyrene microtiter plates.

Fabrication of blue light-blocking optical interference coatings by the solgel method.

We report on the solgel method of fabrication of thin films of high optical quality and with tunable index of refraction. The resulting coatings are hard, durable and robust against humidity and common organic solvents. Bragg mirrors and edge filters have been made by stacking these films.

Linearly polarized Q-switched ceramic laser made with anisotropic nanostructured thin films.

A polarizing laser mirror was made of an alternating sequence of low and high refractive index layers of titanium oxide using glancing angle deposition (GLAD). Large refractive index contrast and large birefringence, reaching 0.5 and 0.

Compact linearly polarized ceramic laser made with anisotropic nanostructured thin films.

A novel method is proposed for the fabrication of polarizing laser mirrors for compact solid-state lasers using glancing angle deposition. Changing the inclination angle and the azimuthal orientation of the substrate during deposition allows one to create and control in-plane birefringence of a deposited thin film by changing its nanostructure. Principal refractive indices of tungsten trioxide films were determined for various deposition angles using transmission and reflection ellipsometry.

Fabrication of high-quality VO2 thin films by ion-assisted dual ac magnetron sputtering.

The technique of cathodic ac dual magnetron sputtering along with the high energy ionic bombardment is known to yield high-quality thin films in terms of their uniformity and high density. This technique has been applied for the first time to achieve thermochromic VO2 thin films that show a high optical and electrical contrast between normal and switched states. In this two-step process Vanadium metal films were deposited and subsequently oxidized in optimum conditions to achieve stoichiometric VO2 films.

Mid-IR laser beam quality measurement through vanadium dioxide optical switching.

We present a beam characterization system for infrared lasers which can measure both wavefront and beam profile with visible detectors. While previous studies demonstrated the conversion from the visible to the near infrared, this device exploits the wavelength conversion from the infrared to the visible, which is based on the refractive index change because of the optical switching of a vanadium dioxide layer. This technique can be applied over a broad spectral range from the visible to the infrared and potentially to the terahertz.

Mid-IR to near-IR image conversion by thermally induced optical switching in vanadium dioxide.

We demonstrate the image conversion from mid-IR to near-IR (NIR) exploiting high-contrast optical switching in vanadium oxide thin-film layers. The intensity distribution of a mid-IR beam is converted to NIR wavelengths exploiting the strong reflectivity changes induced by optical pumping in the mid-IR. We show an experimental setup in which the radiation of a Tm-doped fiber laser at 1940 microm and a carbon dioxide at 10.

Transmission and reflection ellipsometry of thin films and multilayer systems.

Ellipsometric studies are generally carried out in the reflection mode rather than in the transmission mode, requiring invariably opaque substrates or substrates in which the backreflection is minimized or suppressed by different methods. In the present research we used a transmission and reflection photoellipsometry method to study electrochromic materials and their multilayer systems deposited on thick substrates. The role of the substrate is examined carefully, and the contributions from multiple reflections in the substrate are taken into account in the theoretical treatment.

Design of a physical vapor transport cell for time controlled deposition of nucleation phase organic thin films.

A portable high vacuum chamber has been designed to implement a solenoid operated shutter used as a substrate cache during short duration deposition of organic thin films via the physical vapor transport (PVT) method. This PVT cell was designed for the study of gravity effects on nucleation phase organic thin films obtained in laboratory unit g conditions and especially low g conditions found onboard parabolic flights. The design challenges met were, notably, the timely control of deposition on the substrate during parabolas and maintenance of the experimental cell pressure during operation of the shutter.

Reflection-transmission photoellipsometry: theory and experiments.

We propose a method that uses reflection and transmission photoellipsometry to analyze samples consisting of thin films combined with semitransparent thick layers or substrates in the form of multilayer structures. Athick film or substrate is defined as a layer for which no interference effects can be observed for a given wavelength resolution, and contributions from multiple reflections in the substrate are taken into account in the theoretical treatment. An automatic reflection-transmission spectroscopic ellipsometer was built to test the theory, and satisfactory results have been obtained.