W ith protein biologics, it is critical to accurately determine an absorptivity constant. The constant is then used when routinely measuring protein concentration by ultraviolet (UV) spectrophotometry. The yield of product during manufacture and the product content and potency on the label are dependent on this constant. There have been several approaches in the past to determining the constant...

Stratospheric ozone depletion and the concomitant increase in irradiance of ultraviolet-B radiation (UVB) at the earth’s surface represent major threats to terrestrial and aquatic ecosystems. In costal rocky shore environments, seaweeds constitute a group of organisms of particular significance to ecosystem function. Thus, impairment of seaweed performance by UVB-exposure may result in severe c...

We report the demonstration of a scanning probe coherent diffractive imaging method (also known as ptychographic CDI) using a compact and partially coherent gas-discharge plasma source of extreme ultraviolet (EUV) radiation at a 17.3 nm wavelength. Until now, CDI has been mainly carried out with coherent, high-brightness light sources, such as third generation synchrotrons, x-ray free-electron ...

A considerable reduction in stratospheric ozone concentration above different latitudes due to the increased ultraviolet-B radiation has been reported by NASA experts. The enhanced ultraviolet radiation affects major metabolic processes in living organisms and causes damages to many organic molecules including DNA. Deep understanding of ultraviolet-B rays impact on plants and animals, is a matt...

Quantification of ocular exposure to ultraviolet-B radiation (UV-B) has become an important public health issue, with reports that the ozone layer is being depleted worldwide. Ocular exposure to UV-B is determined by ambient UV-B levels, the duration of outdoor exposure, the proportion of ambient UV-B that reaches the eye, and the use of ocular protection. We have developed a simplified model f...

INTRODUCTION Anti-oxidant activities of adrenergic β-blockers are proposed in various organs. The aim of the present study was to investigate the effect of carteolol hydrochloride, an adrenergic β-blocker, on the production of reactive oxygen species (ROS) and the viable cell number after ultraviolet irradiation of cultured lens epithelial cells (LECs). MATERIALS AND METHODOLOGY Cultured LECs...

We provide an overview of geoengineering by stratospheric sulphate aerosols. The state of understanding about this topic as of early 2008 is reviewed, summarizing the past 30 years of work in the area, highlighting some very recent studies using climate models, and discussing methods used to deliver sulphur species to the stratosphere. The studies reviewed here suggest that sulphate aerosols ca...

This paper examines the potential of polysulphone film (PSF) as a dosimeter for unweighted solar ultraviolet-B radiation (UVB; 280 to 320 nm) in different seawater conditions in tropical latitudes. PSF's accuracy is determined by water type and depth range. The film may be used over a depth range of 7 m with measurement errors of less than 5 % in oceanic type waters, such as are found around co...

A polar metabolite of 24,ZSdihydroxyvitamin DS has been generated both in vivo in rats from 25-hydroxyvitamin D3 and in vitro from 24,25-dihydroxyvitamin DS with chicken kidney homogenates. This metabolite has been isolated in pure form and identified as 1,24,25-trihydroxyvitamin Da by means of ultraviolet absorption spectrophotometry, mass spectrometry and its reactivity to periodate treatment...

The degradation behavior of cefixime trihydrate was investigated under different stress conditions of acidic hydrolysis, alkaline hydrolysis and oxidation using spectrophotometry. Stability indicating spectrophotometric methods were developed that could separate the drug from its degradation products formed under these stress conditions. The UV spectral characteristics of the drug and degraded ...