Several proposals to construct artificial photoresponsive polymer systems have been described. chromophores in the backbone reversibly changed the conformation by ultraviolet light irradiation(410 > > 350 nm), which causes the trans to cis isomerization of the chromophores. Aqueous solutions of poly(N-isopropylacrylamide) with pendant azobenzene chromophores showed a photostimulated phase separ...

The structural changes associated with the ultraviolet-induced bleaching of light-grown cells of Euglena gracilis were investigated. Our lightand electron-microscopic observations of the bleaching process indicate that there is a continuity of plastid structure in cells 5 generations after receiving a bleaching dose of ultraviolet light. There seems to be a continuous dilution of the plastid th...

Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are...

The ichthyotoxin of Prymnesium parvum is inactivated by visible (400 to 510 mmu) as well as by ultraviolet light (255 mmu). The changes in the absorption spectrum of purified (pigment-free) ichthyotoxin during this process indicate that different mechanisms may be involved in the inactivation by visible or ultraviolet light. Photoinactivation is not affected by the presence of cells, cell pigme...

C3N4/TiO2 hybrid photocatalysts with highly enhanced photocatalytic performance were prepared by a facile ball milling method. A layered structure of g-C3N4 was formed on the surface of TiO2. The mechanochemical process can promote the dispersion of C3N4 on the surface of TiO2 particles, to form a single layer hybrid structure and a multi-layer core-shell structure. The photocatalytic activitie...

The effect of light scattering on measurement of UV absorbance and penetration of germicidal UVC irradiance in a UV reactor were studied. Using a standard spectrophotometer, absorbance measurements exhibited significant error when particles that scatter light were present but could be corrected by integrating sphere spectroscopy. Particles from water treatment plants and wastewater effluents ex...

Action spectra for delayed light production by several algae were determined from 250 to 750 mmicro incident light. In the visible portion of the spectrum the action spectra resemble those reported by previous workers for photosynthesis and light emission. Blue-green algae had a maximum at 620 mmicro, red algae at 550 mmicro, whereas green and brown algae have action spectra corresponding to ch...

Exposure to X-rays, high-intensity visible light or ultraviolet radiation results in alterations to protein structure such as the breakage of disulfide bonds, the loss of electron density at electron-rich centres and the movement of side chains. These specific changes can be exploited in order to obtain phase information. Here, a case study using insulin to illustrate each step of the radiation...

Ultraviolet is an important component of the photic environment. It is used by a wide variety of animals and plants in mutualistic communication, especially in insect and flower inter-relationships. Ultraviolet reflections and sensitivity are also becoming well considered in the relationships between vertebrates and their environment. The relative importance of ultraviolet vis à vis other prima...