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Precise wavelength predictions are presented for the 3s3p^3P_1–3s3p^3P_2 magnetic-dipole transitions, the 3s3p^3P_0–3s3p^3P_2 electric-quadrupole transitions, and the 3s^2 1S_0–3s3p^3P_1 intercombination lines for all members of the Mg isoelectronic sequence with Z ≤ 45. Magnetic-dipole and intercombination transitions of this type have recently been observed in tokamak spectra and have applications for localized diagnostics in high-temperature plasmas. The predictions are based on interpolations and extrapolations of empirical regularities, which also provide insights into the dynamics of these atomic systems.

'General' objects, which are specially prepared to possess restricted spatial frequency spectra, have been used in the conventional Lau experiment to obtain experimental proof for the existence of lateral periodicity arising from axial periodicity, for a subclass of axially periodic wavefields in an incoherent situation.

Exact phase calculations for general squeezed states are presented. Results are given for different phase definitions, using number-state expansions. It is shown that the calculations based on the measured-phase-operator formalism leads to contrasting behavior compared with those based on the Susskind–Glogower, Lerner–Lynch, and Hermitian-phase-operator formalisms.

Polarization holographic and surface-relief gratings have been recorded in an amorphous azobenzene polyester by use of a frequency-doubled argon-ion laser beam at 257nm. Higher excited states of azobenzene in the trans and cis configurations contribute to the formation of a diffraction grating in this experiment. A combination of right and left circularly polarized writing beams has been found to give the highest diffraction efficiency. The contributions to the total phase difference that arise from anisotropy and surface relief have been separated experimentally, and it is shown that the surface-relief grating contributes a larger phase difference than that which is due to anisotropy.

A simple semiclassical model is used to describe the 1≥3 term energies in Cs I. The passive electrons are treated as a thin hollow shell of charge that can be polarized and penetrated by an active electron in a quantized Kepler orbit. The data are parameterized by weighted nonlinear least-squares adjustment of effective values for the dipole and quadrupole polarizabilities, the core radius, and the penetrated charge. The formulation represents the data well, permits predictive extrapolations, and provides intuitive insights into penetration effects. It is shown that apparent differences in the effective quadrupole polarizabilities inferred from the ƒ and g series are removed when penetration effects are included.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Membrane microdomains rich in cholesterol and sphingolipids, including gangliosides (GGs), are known to be important regions for cell signaling and binding sites for various pathogens. Cholesterol depletion inhibits the cellular entry of pathogens and also reduces inflammatory signals by disrupting microdomain structure. Our previous study showed that dietary gangliosides increased total ganglioside incorporation while decreasing cholesterol in the intestinal mucosa. We hypothesized that diet-induced reduction in cholesterol content in the intestinal mucosa disrupts microdomain structure resulting in reduced pro-inflammatory signals. Male weanling Sprague-Dawley rats were fed semipurified diets for 2 weeks. Experimental diets were formulated to include either ganglioside-enriched lipid (GG diet, 0.02% gangliosides [w/w of diet] ) or polyunsaturated fatty acid (PUFA diet, 1% arachidonic acid and 0.5% docosahexaenoic acid, w/w of total fat), in a control diet containing 20% fat. Levels of cholesterol, GG, caveolin, platelet activating factor (PAF), and diglyceride (DG) were measured in the microdomain isolated from the intestinal brush border. The GG diet increased total gangliosides by 50% with a relative increase in GD3 and a relative decrease in GM3. Cholesterol content was also reduced by 23% in the intestinal microdomain. These changes resulted in a significant decrease in the ratio of cholesterol to ganglioside. The GG diet and the PUFA diet were both associated with reduction in caveolin, PAF, and DG content in microdomains, whereas no change occurred in the ganglioside profile of animals fed the PUFA diet. Dietary gangliosides decrease the cholesterol/ganglioside ratio, caveolin, PAF and DG content in microdomains thus exerting a potential anti-inflammatory effect during gut development.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.