Introduction: Normal exposure to sunlight results in the production of vitamin D in human body, which happens because of the interaction between ultraviolet radiation and cholesterol in skin. Exposure to sunlight is responsible for 90 percent of vitamin D needed for the body. Studies show that Iran is a country with high percentage of lack of vitamin D (83 percent). Based on pr...

It has recently been shown that polarisation modulated differential surface plasmon sensing can be used to monitor refractive index changes f approximately 2× 10−7 refractive index units. The information for these measurements is carried by a small-modulated light component and relatively large constant background signal. These measurements have, hitherto, only been carried out as point measure...

Reflection is a natural phenomenon that occurs when light passes the interface between materials with different refractive index. In many applications, such as solar cells or photodetectors, reflection is an unwanted loss process. Many ways to reduce reflection from a substrate have been investigated so far, including dielectric interference coatings, surface texturing, adiabatic index matching...

Optical fiber Bragg gratings (FBG) are key devices for optical communication and sensors. FBGs are based on a periodic variation in the refractive index of the fiber core and allow for the reflection of a narrowband signal centered at a specific Bragg wavelength. Over the last two decades, FBGs have been manufactured mainly by modifying the core refractive index using interferometric or point-b...

BACKGROUND Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are thought to be associated with the pathogenesis and spread of psoriatic disease. This study was designed to investigate the plasma levels of MMP-3, MMP-9 and TIMP-3 in plaque psoriasis patients prior to and following a course of ultraviolet B narrowband treatment with respect to disease advancement. METHODS Pla...

background: light is an important and adjustable physical factor in the job environment.this study aimed to determine the intensity of natural and mixed light and also the level of ultraviolet radiation in libraries and computer sites of ilam universities in spring 2011.   methods: in this cross-sectional study, 10 libraries, 16 study saloons, and 7 computer sites were selected. luminosity asse...

Abstract Unique technique is currently demonstrated for preparation of ultraviolet protective cotton fabrics with full shielding effect, via self-implantation palladium (Pd) nanoclusters. Palladium nanoclusters were in-situ immobilized within native and cationized using two different concentrations precursor (20 60 mM) under strong acidic (pH 2) basic 11.5) media. Cationization (50 100%) was pe...

The incidences of malignant melanoma in situ (MMIS) and invasive malignant melanoma are rising in the United States, but few studies have examined risk factors for MMIS. We evaluated the risk of MMIS according to the host phenotype and the ultraviolet index of the state of residence. Prospective data were collected via biennial questionnaires from 250,151 women and men aged ≥20 years in the Nur...

Introduction: Solar radiation has a major role in design, utilization, development, and planning of solar energy. The most important source of natural ultraviolet radiation is the sun, which has an important role in many biologic processes. Some of these processes are useful, like the production of vitamin D in the body, or curing rickets, and some of them are not, such as ski...

cerium oxide (ceria) nano particle, as photodegradation prevention agent was studied in water-based polyurethane clear coat  systems. polyurethane coatings show superior weathering resistance compared with acrylic melamine systems. however, any chemical change has detrimental effects on the property profile of pu coatings. coatings containing various amounts of cerium oxide nanoparticles were p...