Vibrational spectroscopic studies and computational study of 4-fluoro-N-(2'-hydroxy-4'-nitrophenyl)phenylacetamide

Fourier-transform infrared (FT-IR) and FT-Raman spectra of 4-fluoro-N-(2'-hydroxy-4'-nitrophenyl)phenylacetamide were recorded and analyzed. A surface-enhanced Raman scattering (SERS) spectrum was recorded in silver colloid. The vibrational wavenumbers and corresponding vibrational assignments were examined theoretically using quantum mechanical calculations. The red shift of the NH stretching wavenumber in the IR spectrum from the calculated wavenumber indicates the weakening of NH bond resulting in proton transfer to the neighboring oxygen atom. The presence of CH(2) and NO(2) modes in the SERS spectrum indicates the nearness of these groups to the metal surface, which affects the orientation and metal molecule interaction. The presence of phenyl ring deformation bands, show a tilted orientation of the molecule with respect to the silver surface. The first hyperpolarizability and predicted infrared intensities are reported. The calculated first hyperpolarizability is comparable with the reported values of similar structures and is an attractive object for further studies of nonlinear optics. (c) 2011 Elsevier B.V. All rights reserved

Either taking it easy or feeling too tired: old Cory's shearwaters display reduced activity levels while at sea

It has long been known that birds change their behaviour, reproductive performance and survival as they mature, including in the first few years after recruitment into the breeding population. However, and contrasting with the description of patterns of actuarial and reproductive senescence in later years, there are surprisingly few studies documenting changes in behaviour in old individuals. Such studies are important, as birds provide particularly interesting models for studying the biology of senescence. It has been suggested that, unlike mammals, birds may remain physically fit until an advanced age, yet this has limited empirical support. In this paper, we used activity (immersion) loggers to show that old (>26 years) Cory’s Shearwaters Calonectris diomedea are less active when foraging at sea, spend more time resting on the water and have a smaller number of take-offs and landings during darkness, when compared to experienced mid-aged individuals (13–20 years old). Old individuals also tended to have reduced immune response against an experimental challenge using phytohaemagglutinin. These results are in line with observed reductions in activity levels with age in a wide range of non-avian taxa, and may suggest that old seabirds are physically less fit than younger individuals. Alternatively, old birds might simply be more experienced and their reduction in activity might reflect a strategic regulation of investment in different activities. Our study illustrates the potential for gaining insights into avian aging patterns and processes by looking into the behaviour of model organisms. We therefore encourage more research focusing on behavioural parameters that may reflect variations in physical condition or strategic choices, during both the breeding and non-breeding seasons

Effects of europium polyoxometalate encapsulated in silica nanoparticles (nanocarriers) in soil invertebrates

Polyoxometalates (POMs) are metal oxo clusters that have been investigated for several applications in material sciences, catalysis, and biomedicine; these gained increasing interest in the field of nanotechnology as nanocarriers for drug delivery. Associated to the increasing applications, there is the need for information regarding the effects on the environment of these compounds, which is completely absent in the literature. In the present study, the effects of europium polyoxometalates encapsulated into silica nanoparticles (Eu-POM/SiO2 NPs) were assessed on the soil representative Enchytraeus crypticus. The individual materials were also assessed (Eu-POMs and SiO2 NPs). Toxicity was evaluated in various test media with increasing complexity: water, soil/water extracts, and soil. Toxicity was only observed for Eu-POM/SiO2 NPs and in the presence of soil components. Despite the fact that effects were observed for concentrations higher than current predicted environmental concentration (PEC), attention should be given to the growing use of these compounds. The present study shows the importance of assessing the effects in soil media, also compared to water. Moreover, results of \"no effect\" are critically needed and often unpublished. The present study can contribute to the improvement of the OECD guidelines for safety of manufactured nanomaterials on environmental toxicity in the soil compartment providing an improved test alternative