Utra Violet Radiation

Prevention of solar ultraviolet radiation in organisms involves the generation of secondary metabolites, such as pigments that absorb ultraviolet and visible light. In this study, Antarctic bacteria, Janthinobacterium sp. From. The vioA gene of tryptophan 2-monooxygenase involved in biosynthesis pathway of violet-like purple purple (PVP) was cloned and sequenced. Ant 5-2. A colorless vioA mutant was obtained after mutagenesis of the mini Tn10 transposon, which produced a small amount of exopolymer (EPS) and showed impaired survival of the freeze-thaw cycle at 4 ° C.

This study shows that the mechanical properties of polyurea's low strain rate are a function of the duration of ultraviolet irradiation. Polyurea samples were cast and continuously exposed to UV light for 15 weeks to simulate direct sunlight exposure of about 9,200 hours. Each sample (unexposed and exposed) was uniaxially tested according to ASTM D 638-8 with semi-static tension. Stress-strain data were used to calculate the elastic modulus of polyurea, 0.2% offset yield stress, shear modulus and stress at 250% strain. In addition, UV - Vis and scanning electron spectroscopy (SEM) were used to study the optical properties and surface topography of polyurea, respectively. Finally, we apply stress-strain data to Ogden's superelastic model. Ogden's fitting parameter is due to UV exposure time

The sun is the main source of ultraviolet radiation, and some artificial sources include welding machines, tanned beds, lasers and so on. Most people know the harmful effects of ultraviolet rays of the skin, but many people do not know that ultraviolet rays can hurt the eyes and eyesight. In fact, UV-C, UV-A, UV-B have three kinds of ultraviolet rays. It is said that UV - C is absorbed by the ozone layer and is not harmful. On the other hand, UV-A and UV-B radiation are said to cause short-term and long-term damage to eyes and vision.

People using XP are very sensitive to ultraviolet rays (UV) from the sun. This includes UV A and UV B. Even a very small amount of ultraviolet radiation can cause severe sunburn and blisters from very young age. Sensitivity to ultraviolet light leads to areas where lighter freckles and skin pigmentation are lighter. They may also have very dry skin. The risk of skin cancer and melanoma of squamous epithelial cells and basal cells is high. People with XP, especially eyelids, also have eye problems. Just like their skin, their eyes are also very sensitive to light, which increases the risk of their eye cancer. Cancer of lips, mouth, tongue has also been reported. In addition, people with XP may have neurological complications including developmental disorders, mental retardation, and high frequency hearing loss causing hearing loss.