The bright X-ray binary pulsar Hercules X-1 has a 35-day cycle in hard x-ray intensity: ”Main High state – low state – Short High state – low state”. This is caused by a tilted-twisted precessing accretion disk. What is less well known is that during low states the soft x-rays and extreme ultraviolet radiation are modulated at the orbital period . This radiation is mainly due to reflection off ...

The advantages and disadvantages of sources emitting either a continuous or a discontinuous spectrum are considered in connection with the use of such lamps as a standard of ultraviolet radiation. It is shown that because of the high intensity and favorable distribution of the ultraviolet emission lines at 2967 to 3132 A, the quartz mercury-arc lamp is well adapted for standardizing photoelectr...

Changes in ultraviolet light radiation can act as a selective force on the genetic and physiological traits of a microbial community. Two strains of the common soil bacterium Pseudomonas stutzeri, isolated from aquifer cores and from human spinal fluid were exposed to ultraviolet light. Amplification length polymorphism analysis (AFLP) was used to genotype this bacterial species and evaluate th...

Phototherapy is the use of non-ionizing radiation, primarily in the ultraviolet spectrum, to treat disease. In dermatology, ultraviolet (UV) phototherapy remains an established, lower cost, and often preferred option for many common skin conditions, despite the introduction of newer potent biologics. This article introduces a principal therapeutic modality in the treatment of psoriasis, atopic ...

Clean air in the operating room is important during joint replacement surgery. We compared monochromatic ultraviolet radiation of254 nm with the use ofa Charnley-Howorth air enclosure by bacterial air-sampling during 113 total hip arthroplasties. Air samples were taken continuously at the edge of the wound and every 15 minutes at a site 130 cm from the operating table. We also tested the effect...

Squamous cell carcinoma (SCC) of the skin is one of the mostcommon non melanoma skin cancers (NMSC), along withbasal cell carcinoma (BCC). Besides ultraviolet radiation,exposure to industrial agents, ionizing radiation, and areas ofchronic inflammation are associated with the development ofSCC. Squamous cell carcinoma may also be associated withforeign bodies. We report a rare case of cutaneous...

background: despite their simplicity and the low-cost, the conventional non-contact uv systems have low efficiency in water disinfection. the purpose of this study was to examine the possibility of upgrading these systems by some modifications in order to maximize the water contact with the uv radiation and as a result a better disinfection.    methods: in this study, two enhanced models of non...

Rosemary is commonly used as a spice and a flavoring agent in food processing. Although the antioxidative properties of its extracts have been investigated, there have been few reports on the volatile components of rosemary. We designed a novel antioxidative system which can generate the volatile constituents in the gaseous phase from a rosemary extract and evaluated the gaseous antioxidative a...

The effect of ultraviolet light in delaying certain events in the cell division cycle has been examined. The time to fusion of the egg and sperm nucleus is not affected by doses of ultraviolet that cause considerable delay in other parts of the cycle. The principal delay occurs before anaphase. Between anaphase and cleavage there is only slight delay. The "refractory period" during which the ra...