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Irradiated Area (irradiated + area)

Distribution by Scientific Domains

Polymers and Materials Science	50%

Selected Abstracts

Pattern Formation of Silver Nanoparticles in 1-, 2-, and 3D Microstructures Fabricated by a Photo- and Thermal Reduction Method

ADVANCED FUNCTIONAL MATERIALS, Issue 14 2010
Jong-Jin Park
Abstract One-, two-, and three-dimensional microstructures with dispersed silver nanoparticles are fabricated by a combination of photopatterning and thermal treatment from a silver salt containing photosensitive epoxy resin. Ultraviolet photo-irradiation and subsequent thermal treatment are combined to control the rate of silver salt reduction, the size and the arrangement of nanoparticles, as well as the reticulation of the epoxy resin. This approach allows the creation of high resolution 1-, 2-, and 3D patterns containing silver nanoparticles, with a homogeneous distribution of nanoparticles regardless of the irradiated area. [source]

Light-Induced Reorganization in Self-Assembled Liquid Crystal Gels: Electrically Switchable Diffraction Gratings,

ADVANCED MATERIALS, Issue 17 2003
Y. Zhao
Electrically switchable diffraction gratings can be formed in the self-assembled cholesteric liquid crystal gels prepared using an azobenzene-containing gelator. The grating formation (see Figure) results from a light-induced reorganization process in these materials, which leads to the removal of the nanometer-sized fibrous aggregates of the gelator from the irradiated area to the non-irradiated area. [source]

Long-term results after reconstruction of full thickness scalp defects with a dermal regeneration template

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 5 2010
J Faulhaber
Abstract Objective, Large scalp defects in which the pericranium has to be resected can be reliably reconstructed using Integra®. In the present study, we retrospectively analysed the long-term outcome of our patients. Methods, Nineteen patients were included who had received Integra® dermal regeneration template for treatment of full thickness scalp defects after resection of various malignant tumours. All patients were followed up with a mean follow-up time of 31 months (14,72). Results, All transplants were on almost equal levels with the surrounding skin. Cosmetic results were acceptable and scars were stable. Nodal ultrasound status was negative in all patients. During the follow-up period of up to 72 months, no local recurrences were observed. One patient with a leiomyosarcoma received radiotherapy after transplantation. In the irradiated area, multiple small regular-shaped round ulcerations and later on partial necrosis of the transplant occurred when the patient developed renal failure 29 months after the initial operation. Five patients died of disease not related to the primary skin tumour. All other patients are alive and free of disease without any complications. Conclusion, After reconstruction of full thickness scalp defects with Integra®, the cosmetic results are appealing and we observed no local recurrences during the follow-up period. [source]

Polychromatic Light Similar to the Terrestrial Solar Spectrum Without its UV Component Stimulates DNA Synthesis in Human Peripheral Blood Lymphocytes In Vivo and In Vitro

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 5 2006
Natalya A. Zhevago
ABSTRACT Immunosuppressive effects of the minor component of the terrestrial solar spectrum, UV radiation, have been substantiated over the past several years. This raises the question of what influence the dominant part of the solar spectrum,visible and IR light,would have on the human immune system. In the present randomized, placebo-controlled double-blind study a small area of the body surface of volunteers was irradiated with polychromatic light (480,3400 nm), simulating the significant part of the terrestial sunlight irradiance spectrum and its power density. An average 2.5-fold to three-fold increase in spontaneous and phytohemagglutinin-induced DNA synthesis in peripheral blood lymphocytes (Lym) was revealed at 0.5,24 h after irradiation at a therapeutic dose (12 J/cm2) in subjects with low preirradiation levels of both processes. The in vivo findings were echoed in parallel in vitro experiments, when blood drawn from the same subjects was directly irradiated (2.4 J/cm2), or when the irradiated blood was mixed 1:10 with nonirradiated autolo-gous blood to model events in the circulation following transcutaneous blood photomodification. Our data suggest that exposure of the human body to polychromatic visible + IR light may photomodify blood in the dermal vasculature of the irradiated area to lead to an immediate transfer of the light-induced effects to Lym of the entire circulating blood, which can result in modulation of Lym functional state at the systemic level. [source]

Grayscale Photopatterning of an Amorphous Polymer Thin Film Prepared by Photopolymerization of a Bisanthracene-Functionalized Liquid-Crystalline Monomer

ADVANCED FUNCTIONAL MATERIALS, Issue 10 2010
Hideyuki Kihara
Abstract A method for grayscale photopatterning of an amorphous polymer film derived from a bisanthracene-functionalized liquid-crystalline monomer is developed. Solution photopolymerization of a monomer with two anthracene moieties, one at each end, affords an amorphous polymer. A combination of irradiation with patterned UV light and heating results in photopatterning on thin films prepared from the polymer. On non-irradiated areas of the film, the polymer reverts to the monomer owing to the thermal back-reaction of the anthracene photodimer, forming an ordered phase. On irradiated areas remaining in the amorphous phase, the thermal back-reaction is suppressed. This phenomenon results in a clear contrast and visual images on the film under polarized light. Grayscale photopatterning is also made possible for the solution-polymerized polymer by controlling the intensity of exposure. In addition, rewritable photopatterning can be achieved by melt photopolymerization of the monomer. The new photopatterning is essentially nondestructive because it needs neither image development nor anthracene-excitation light for reading. [source]

Laser local oxidation of porous silicon: a FTIR spectroscopy investigation

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2005
M. Rocchia
Abstract The local oxidation of porous silicon (PS), induced by a focused laser beam, could represent an alternative method for patterning PS through direct writing. Important phase changes take place on PS when irradiated by a focused laser beam and moreover a complete confinement of the oxidized areas can be achieved due to the very low thermal conductivity of PS. We present a detailed Fourier Transform InfraRed (FTIR) study of the irradiated areas to understand the degree of oxidation and the type of oxide obtained at different laser powers. An interpretation of the low wavenumber range, below 1300 cm,1, in terms of Fröhlich interactions will be discussed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]