Microspectrophotometric (msp) studies have shown that the colour-vision system of many bird species is based on four pigments with absorption peaks in the red, green, blue and UV regions of the spectrum. The existence of a fourth pigment (UV) is the major difference between the trichromacy of humans and the tetrachromacy of such birds, and recent studies have shown that it may play a determinin...

UV-visible absorption and AFM studies suggest that carboxyphenylethynyl zinc porphyrins aggregate on nanocrystalline TiO2 surfaces in an H-type fashion.

In this work we report the effects of continuous UV-light (276 nm, ~2.20 W.m(-2)) excitation of human insulin on its absorption and fluorescence properties, structure and functionality. Continuous UV-excitation of the peptide hormone in solution leads to the progressive formation of tyrosine photo-product dityrosine, formed upon tyrosine radical cross-linkage. Absorbance, fluorescence emission ...

UV-visible absorption spectroscopy is useful for probing the electronic and structural changes of protein active sites, and thus the on-line combination of X-ray diffraction and spectroscopic analysis is increasingly being applied. Herein, a novel absorption spectrometer was developed at SPring-8 BL26B2 with a nearly on-axis geometry between the X-ray and optical axes. A small prism mirror was ...

The Warm-Hot Intergalactic Medium (WHIM) arises from shock-heated gas collapsing in large-scale filaments and probably harbours a substantial fraction of the baryons in the local Universe. Absorption-line measurements in the ultraviolet (UV) and in the X-ray band currently represent the best method to study the WHIM at low redshifts. We here describe the physical properties of the WHIM and the ...

We have used UV resonance Raman and absorption spectroscopy to examine the secondary structure of angiotensin 11 ( AII) in aqueous solution and in phospholipid micelles. Absorption difference spectroscopic measurements are used to determine the association constant of A11 with dodecylphosphocholine (DPC) micelles, and the UV Raman spectral data are used to examine the secondary structure altera...

a new method for the synthesis of water soluble polyaniline (pani) using hemin chloride (h.c) in the presence of hydrogen peroxide (h.p) is presented. hemin chloride is an effective catalyst for the oxidative polymerization of aniline in the presence of hydrogen peroxide at room temperature. the uv- vis absorption spectra of the product show a distinct absorption peak at 430 nm in ph 4.0 b...

Light-absorbing and high-molecular-weight secondary organic products were observed to result from the reaction of glyoxal in mildly acidic (pH=4) aqueous inorganic salt solutions mimicking aqueous tropospheric aerosol particles. High-molecular-weight (500–600 amu) products were observed when ammonium sulfate ((NH4)2SO4) or sodium chloride (NaCl) was present in the aqueous phase. The products fo...

While structurally complex benthic egg capsules can lower the vulnerability of gastropod embryos to a variety of environmental risks, including predation, desiccation, osmotic shock, and bacterial attack, little is known about their ability to shield embryos from ultraviolet radiation (UV) I examined the exposure of benthic egg capsules of the marine intertidal gastropod Nucella emarginata to s...

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...