dispersive liquid-liquid microextraction method (dllme) combined with high-performance liquid chromatography-ultraviolet detection (hplc-uv) was used to determine thiamine (b1), nicotinamide (b3) and pyridoxine (b6) in sour cherry juice. this method was rapid, simple and sensitive. separation was accomplished using a c18 column. the optimum chromatographic conditions were found to be: mobile ph...

in this study, a computational fluid dynamics (cfd) model was developed to evaluate ultraviolet disinfection applesauce reactor. to simulate uv reactors, three sets of equations, including hydrodynamics, radiation and species mass conservation were solved simultaneously. the realizable k-e turbulence model and the discrete ordinate method were used to find the uv radiation profile through the r...

xerodermapigmentosum (xp), is an autosomal recessivegenetic disorder of dna repair in which the ability to repair damage caused by ultraviolet (uv) light is deficient. the oxidative stress caused by decline catalase activity as an antioxidant enzyme, has been illustrated in these patients. this is the first case report of dilated cardiomyopathy in two patients with xp, a 26 year old girl and he...

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...

We have found evidence for ultraviolet visual capabilities in a Lake Malawi cichlid fish, Metriaclima zebra. Microspectrophotometry of single cones revealed a visual pigment with peak sensitivity at 368+/-4 nm. M. zebra also expresses a putative ultraviolet opsin gene whose sequence is closely related to the SWS-1 opsin for other fishes. Several other African cichlids have a functional copy of ...

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...

Ultraviolet radiation is known to inhibit photosynthesis, induce DNA destruction and cause damage to a wide variety of proteins and lipids. In particular, UV radiation between 200-300 nm becomes energetically very damaging to most of the terrestrial biological systems. On the other hand, UV radiation is usually considered one of the most important energy source on the primitive Earth for the sy...

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...