نتایج جستجو برای: uv exposure

تعداد نتایج: 372933  

2002

Schoolchildren in their everyday school life are exposed to solar ultraviolet (UV) radiation. This may be through time spent outdoors whilst having meal breaks, physical education classes or other outdoor class orientated activities. This research, conducted at the University of Southern Queensland, investigates the UV exposure of schoolchildren and the effect real-time UV irradiances data and ...

2006
Michael Y. Roleda Margaret N. Clayton Christian Wiencke

The functional significance of phlorotannins as ultraviolet radiation screens in brown algae is presented. Spectral analysis of zoospore suspensions of the three Arctic Laminariales Saccorhiza dermatodea, Alaria esculenta and Laminaria digitata showed strong absorption in the UV waveband, characteristic of phlorotannins. An induction in the synthesis of the UV-absorbing compound in zoospore sus...

2015

Constant reduction of stratospheric ozone layer and the increase of ultraviolet radiation intensity were observed in last twenty years of the 20th century. Four tree species; Acacia amplicepsis, Acacia gerradii, Casuarina glauca and Eucalyptus intertexta grown in Experimental station of Food and Agriculture Sciences Collage, King Saud University were used to study the impact of UV-C on potentia...

Journal: :Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 2004
Juan Ramos Jaime Villa Abigail Ruiz Roy Armstrong Jaime Matta

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), known as nonmelanoma skin cancer (NMSC), are the most common cancers worldwide. Although many factors are involved in the pathogenesis of NMSC, UV radiation is an important risk factor. A fundamental question in skin cancer research is whether varying doses of total UV radiation influence key characteristics of NMSC. The hypothesis t...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2002
nezameddin daneshvar daryoosh salari mohammad ali behnasuady

anionic dbs surfactant can be photodegraded in a tio2 dispersion and h2o2 solution under an hg-lamp (15 w) uv illumination or solar exposure. degradation process has been monitored through cleavage of aromatic moiety. degradation of the detergent was small when the photolysis was carried out in the absence of tio2 and h2o2 and it was negligible in the absence of light. most of the curves repres...

Journal: :Photodermatology, photoimmunology & photomedicine 2005
H Maier G Schauberger B S Martincigh K Brunnhofer H Hönigsmann

BACKGROUND Photoinstability of sunscreens because of ultraviolet (UV) exposure is a well-known and common phenomenon. Recently, it was also shown that sunscreens with complex filter combinations are photoinactivated by UV exposures, which can easily be acquired by solar exposure over several hours. OBJECTIVES To assess the change of the spectral transmission after UV exposure (UV-challenged p...

Journal: :Journal of bacteriology 1968
F W Adair

Ultraviolet (UV) irradiation inhibited sulfur oxidation by cells of Thiobacillus thiooxidans. Sulfur-oxidizing activity decreased as the exposure time to UV light increased. A loss of the ability of cells of fix CO(2) paralleled the loss of sulfur-oxidizing activity. UV light photoinactivated ubiquinone purified from T. thiooxidans. The same percentage of sulfur-oxidizing activity and ubiquinon...

Journal: :Mutagenesis 2012
Visalini Nair-Shalliker Michael Fenech Peta M Forder Mark S Clements Bruce K Armstrong

The ultraviolet (UV)-B spectrum in solar UV radiation is essential for stimulating the epidermal production of vitamin D but also damages DNA and causes cancer in exposed cells. We examined the role of solar UV in inducing DNA damage in blood lymphocytes and the possible modulation of this damage by serum 25-hydroxy vitamin D (25(OH)D) in 207 male and female participants from South Australia. P...

Journal: :Aquatic toxicology 2012
Sreejith Kottuparambil Woongghi Shin Murray T Brown Taejun Han

The effects of ultraviolet B (UV-B; 295-320 nm) radiation on certain vital physiological (photosynthesis), biochemical (production of reactive oxygen species - ROS) and behavioral (motility and orientation) characteristics were investigated in the unicellular photoautotroph, Euglena agilis Carter. The photosynthetic performance of E. agilis was recorded after exposure of between 15 and 60 min f...

Journal: :Indian journal of experimental biology 2013
J K Sahu M Simek

The effect of UV-C radiation on thylakoid arrangement, chlorophyll-a and carotenoid content and nitrogenase activity of the cyanobacterium Microchaete sp. was studied. Chlorophyll-a and carotenoid content increased gradually up to 48 h of UV-C exposure but declined with longer exposures. Nitrogenase activity decreased moderately with 6 to 12 h exposure and decreased substantially afterwards. Wh...

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