No abstract available.
Ultraviolet Rays*

No abstract available.
Animals ; Mice* ; Ultraviolet Rays*

No abstract available.
Autoradiography* ; DNA* ; Ultraviolet Rays*

OBJECTIVESolar ultraviolet (UV) radiation is an important environmental factor that affects human health. The understanding of diurnal variations of UV radiation at anatomical sites may be helpful in developing ways to protect humans from the harmful effects of UV radiation.

METHODSIn order to characterize the diurnal variations, the UV exposure values were measured at 30 min intervals by using Solar-UV Sensors and a rotating manikin in Shenyang city of China (41 degrees 51'N, 123 degrees 27'E). Measurement data for four representative days (in each of the four seasons respectively) were analyzed.

RESULTSThe diurnal variations in solar UV radiation at the shoulder, the forehead and the chest were similar to those associated with a horizontal control measurement. However, the diurnal variations at the eye and the cheek exhibited bimodal distributions with two peaks in spring, summer and autumn, and a unimodal distribution in winter. The UV exposure peaks at the eye and the cheek were measured at solar elevation angles (SEA) of about 30 degrees and 40 degrees , respectively.

CONCLUSIONThe protection of some anatomical sites such as the eye from high UV exposure should not be focused solely on the periods before and after noon, especially in the places and seasons with high SEA.

Having studied in vitro the effect of UVR on the two species of microorganisms which are most common as agents of surgical infection, we realized the closer the distance from the irradiation lamp and the longer the irradiation time, the stronger the bactericidal effect of UVR. When UVR is applied for air disinfection within the distance of more than 2 meters from the sunlamp irradiation, it can also reduce significantly the number of microorganisms in the air. It is due to the fact that there is a continuous air exchange between the upper and the lower part of the room. Previous studies and the experiments on petri dishes show that the use of UVR for cleaning infected wounds and preventing infection is an effective, simple and safe measure
Ultraviolet Rays ; Blood Bactericidal Activity

Three-dimensional thermoluminescence (TL) spectra from MgAl2O4 irradiated with UV light were measured over 300~600 K and 300~800 nm. The peak positions of TL glow curves were shifted to lower temperature with increasing the exposure time of UV light. The 476 K TL glow curve is due to the second kinetics and its activation energy and escape frequency factor are calculated to be 0.85 eV and 1.92x10(6) sec(-1), respectively. The TL spectra were split into 530 nm and 700 nm emission bands which were associated with V(2+) and Cr(2+), respectively. The linearity range of 700 nm emission band is smaller than that of 530 nm emission band, but the saturation time of 700 nm emission band is longer than that of 530 nm emission band.
Aluminum* ; Kinetics ; Magnesium* ; Ultraviolet Rays ; United Nations

BACKGROUND: Solar furnaces are used worldwide to conduct experiments to demonstrate the feasibility of solar–chemical processes with the aid of concentrated sunlight, or to qualify high temperature-resistant components. In recent years, high-flux solar simulators (HFSSs) based on short-arc xenon lamps are more frequently used. The emitted spectrum is very similar to natural sunlight but with dangerous portions of ultraviolet light as well. Due to special benefits of solar simulators the increase of construction activity for HFSS can be observed worldwide. Hence, it is quite important to protect employees against serious injuries caused by ultraviolet radiation (UVR) in a range of 100 nm to 400 nm. METHODS: The UV measurements were made at the German Aerospace Center (DLR), Cologne and Paul-Scherrer-Institute (PSI), Switzerland, during normal operations of the HFSS, with a high-precision UV-A/B radiometer using different experiment setups at different power levels. Thus, the measurement results represent UV emissions which are typical when operating a HFSS. Therefore, the biological effects on people exposed to UVR was investigated systematically to identify the existing hazard potential. RESULTS: It should be noted that the permissible workplace exposure limits for UV emissions significantly exceeded after a few seconds. One critical value was strongly exceeded by a factor of 770. CONCLUSION: The prevention of emissions must first and foremost be carried out by structural measures. Furthermore, unambiguous protocols have to be defined and compliance must be monitored. For short-term activities in the hazard area, measures for the protection of eyes and skin must be taken.
Compliance ; Skin ; Sunlight ; Switzerland ; Ultraviolet Rays ; Xenon*

Radiational injury to ultra-violet rays has brought to acute flash-eye of occupational type in four patients who didnt used the protective eye-wear; Case 1, a medical physician. 29 yr old male, was occurred the symptoms after exposure of about 3 hrs to ultra-violet lamp in the laboratory. Case 2, a trainee of welding, 19 yr old male, was occurred from electric welding. Cases 3 and 4, all electricians of 38 and 26 yrs old males, were occurred typical photophthalmia from the spark of electric arc. They all revealed prominent hyperemia especially in exposed area of the bulbar conjunctiva.
Conjunctiva ; Humans ; Hyperemia ; Male ; Ultraviolet Rays ; Welding

The color change of maxillofacial silicone has been attributed to certain environmental factors such as exposure to the UV component of natural sunlight, wetting and drying of the elastomer, and surface abrasion resulting from the application and removal of cosmetics. The purpose of this study was to evaluate the color change of maxillofacial silicone (Silastic MDX4-4210) according to type of pigment (cadmium yellow, titanium white, cosmetic red), and UV absorber application method after 200, 400, and 600 hours of 350nm UV light irradiation. The results were as follows. 1. According to type of pigments, after 200 hours cosmetic red showed significantly larger color change than cadmium yellow and titanium white, and after 400 and 600 hours color change significantly decreased in the order of cosmetic red, cadmium yellow, and titanium white (p<0.05). 2. In the cadmium yellow group, after 200 hours, the non-treatment group showed significantly larger color change, but after 400 and 600hours, color change significantly decreased in the order of non-treatment, surface application and mixed group (p<0.05). 3. In the titanium white group, there was no significant color change difference between the three groups after 200 and 400 hours, but after 600 hours, the mixed group showed significantly smaller color change than the non-treatment and surface application groups (p<0.05). 4. In the cosmetic red group, there was significant decrease in color change in the order non-treatment, surface application and mixed group (p<0.05). From the results above, the effect of UV light absorber differed according to the type of pigment, but mixing UV light aborber with maxillofacial silicone is thought to give superior resistance against UV light irradiation in the long run.
Cadmium ; Elastomers ; Silicones* ; Sunlight ; Titanium ; Ultraviolet Rays*

In search of suitable long wave ultraviolet light source which is not available in Korea for photopatch tests and for the treatment of vitiligo and psoriasis. We picked high pressure mercury lamp used for out-door illumination for evaluation. On spectrophotometric examinatio., it is disclosed that the lamp emitted enough long wave ultraviolet rays for our purpose. It requires 6 minutes for photopatch tests at 50 cm for 200 watt bulb. It is recommanded that the commercially available cheap out door illumination lamp should be used for dermatological parposes until equivalent medical equipment is available. The construction and principle of mercury vapor lamp is reviewed.
Korea ; Lighting* ; Psoriasis ; Ultraviolet Rays ; Vitiligo