The resistance of three types of Bacillus cereus T spores to ultraviolet radiation corresponded to their dipicolinic acid (DPA) content. Photoprotection against ultraviolet light was observed in DPA-containing spores and in DPA-less spores irradiated through calcium dipicolinate.

An ultraviolet source may be used in light mi-croscopy to excite visible fluorescence, increase resolution, or differentiate absorbing materials. The last two aims require ultraviolet-transmitting optics, usually of quartz, and have infrequently been sought by bacteriologists, especially since electron microscopy with its vastly increased resolving power became available. However, ultraviolet l...

Acetate grown cells of Azotobacter, like sucrose grown cells (Stone and Wilson, 1952), are unadapted to the oxidation of succinic acid although possessing an enzyme system capable of oxidizing succinate. Hence the adaptation of these cells to succinic acid may be termed a functional change in the physiology of the organism. In contrast, glucose grown cells of Saccharomyces cerevisae are unadapt...

We have found that coupling between catharanthine and vindoline occurs non-enzymatically in the presence of flavin mononucleotide and manganese ions with near-ultraviolet light irradiation in vitro. The present study found that the concentrations of catharanthine and vindoline in Catharanthus roseus decreased and those of dimeric indole alkaloids increased under near-ultraviolet light at 4 degr...

An incipient advanced oxidation process, solar photocatalytic ozonation (SPO), is reviewed in this paper with the aim of clarifying the importance of this process as a more sustainable water technology to remove priority or emerging contaminants from water. The synergism between ozonation and photocatalytic oxidation is well known to increase the oxidation rate of water contaminants, but this h...

Solar radiation is the primary source of human exposure to ultraviolet (UV) radiation. Overexposure without suitable protection (i.e., sunscreen and clothing) has been implicated in mutagenesis and the onset of skin cancer. These effects are believed to be initiated by UV-mediated cellular damage, with proteins and DNA as primary targets due to a combination of their UV absorption characteristi...

The incidence of melanoma and nonmelanoma skin cancers is increasing worldwide. Ultraviolet light exposure is the most important risk factor for cutaneous melanoma and nonmelanoma skin cancers. Nonmelanoma skin cancer includes basal cell carcinoma and squamous cell carcinoma. Constitutive skin color and genetic factors, as well as immunological factors, play a role in the development of skin ca...

The shortest-wavelength color of light that is visible to the human eye is violet. As shown in Fig. 1, light with wavelengths shorter than 400 nm is called ultraviolet (UV) light: that from 300 to 400 nm is called near-UV light, that from 200 to 300 nm is called deep-UV light, and that shorter than 200 nm is called vacuum-UV light. Since vacuum-UV is absorbed by air, deep-UV light is the shorte...

We present optical and ultraviolet observations of 3C 273 covering the whole life of the IUE satellite. We analyze the variability properties of the light curves, and find that two variable components, written B and R respectively, must contribute to the blue-bump emission in this object. The B component produces most of the variability in the ultraviolet domain. A maximum time scale of variabi...

Light sensors are widely used to monitor light intensities, for instance in medical applications, agriculture or conservation of art. Most these electronic devices that record continuously but applications only require information integrated measured over a long time, could greatly benefit from an integrating dosimeter does not power supply. In this work wireless and quantitative is presented b...