278 research outputs found
Unitary and analytic model of nucleon EM structure, the puzzle with JLab proton polarization data and new insight into proton charge distribution
The Unitary and analytic model of nucleon electromagnetic structure,
describing all existing nucleon form factor data, is briefly reviewed. Then in
the framework of this model the problem of inconsistency of older proton
electric form factor data in space-like region (obtained from process by the Rosenbluth technique) with recent Jefferson Lab data on
the ratio (measured in precise polarization
experiment) is suggested
to be solved in favour of the latter data which, however, unlike older data
cause an existence of the form factor zero, i.e. a difraction minimum in
around GeV. The new behaviour of
with the zero gives modified proton charge distribution with enlarged value of
the mean square charge radius.Comment: 9 pages, 11 eps figures. Talk presented at the workshop on Lepton
Scattering and the Structure of Hadrons and Nuclei, Erice (Italy), September
200
Polyacetylenes from Radix et Rhizoma Notopterygii Incisi with an Inhibitory Effect on Nitric Oxide Production In Vitro
Notopterygium roots (Qiang Huo) have been used in traditional Chinese medicine for treating colds, inflammatory diseases like rheumatoid arthritis, and as an analgesic. The anti-inflammatory activity of the roots ofNotopterygium incisum has been evaluated by testing the inhibitory activity on nitric oxide production by inducible nitric oxide synthase. The apparent authenticity of the sample was checked by DNA sequence comparison. Using activity-guided isolation, different compounds were isolated and structurally characterized by means of NMR and mass spectroscopy. Eight polyacetylenes could be identified and were tested on their inhibitory activity on nitric oxide production in RAW 264.7 mouse macrophages using the Griess assay. Different 3-hydroxy allyl polyacetylenes exhibited significant activity (IC50: 8-acetoxyfalcarinol, 20.1 µM; falcarindiol, 9.2 µM; 9-epoxyfalcarindiol, 8.8 µM; and crithmumdiol, 23.6 µM)
- …
