Risk factors and outcome of human immunodeficiency virus-infected patients with sporadic multidrug-resistant tuberculosis in New York City

The discovery of neuroendocrine differentiation in hormone-refractory prostatic adenocarcinoma has opened a potentially new therapeutic approach in this group of patients with a poor prognosis and few effective therapy modalities. Based on previous findings of increased uptake of 11C-5-hydroxytryptophan (11C-5-HTP) in neuroendocrine tumours using the PET technique, this tracer was applied in the study of 10 patients with metastatic hormone-refractory prostatic adenocarcinoma. In three patients, the study was repeated after treatment. An increased uptake of 11C-5-HTP was observed in all investigated skeletal lesions, although the magnitude of the uptake was moderate. The difference between the standard uptake values (SUV) in normal bone and metastatic lesions was significant (p < 0.001). A kinetic analysis of the uptake of 11C-5-HTP demonstrates an increase during the first minutes followed by a wash-out and a stabilization of the tissue/blood ratio at about 2. The Patlak plots demonstrated a gradual increase in the transport rate during the first 20 to 30 min, after which a constant level was observed. The SUV varied between patients and between lesions over time and treatment. The uptake of 11C-5-HTP discriminates metastatic lesions from normal bone and may thus aid in the diagnosis and, potentially, in treatment monitoring of metastatic hormone-refractory prostatic adenocarcinoma. Uptake kinetics are characterized by a wash-out and cannot alone be used as proof of neuroendocrine differentiation in hormone-refractory prostatic adenocarcinoma.     

Amplified spontaneous emission in dye-doped sol-gel amplifiers

Transversely pumped dye doped slab waveguides are investigated. A set of coupled-rate equations for the excited-state population and for the amplified spontaneous emission (ASE) power, at all wavelengths, is presented. The equations are solved numerically for the steady-state case. The results describe the dependence of ASE output power on pumping power, the spectral narrowing process, and the effect of waveguiding. The theoretical calculations are compared with the results of experiments, and good agreement is found     

Reformulation of the coupled-mode theory of multiwaveguide systems

We show that by proper reformulation the coupled-mode theory of Hardy and Streifer can be reconciled with that of Haus et al based on a variational principle. The new formulation has the merit of leading to simpler coupled-mode equations while giving marginally more accurate results.     

Nuclear susceptibility of liquid3He-4He solutions along the demixing line

Pulsed NMR measurements of the nuclear magnetic susceptibility of liquid³He-⁴He solutions at saturated vapor pressure are presented. They extend over the whole temperature range between 50 mK and 825 mK, for both concentrations of the coexisting dilute and³He-rich phases. The results have been compared to those obtained with pure³He, and the temperature dependence of the ratio of molar susceptibilities of coexisting phases is derived. The consequences on the efficiency of fractional distillation as a method to enhance nuclear polarization are discussed.     

THE ISOLATION OF PRECURSORS RESPONSIBLE FOR INSOLUBLES FORMATION IN MID-DISTILLATE DIESEL FUELS

Extraction of mid-distillate fuels with methanol has been found to reduce the tendency of the fuels tested to form insolubles under conditions of accelerated aging. The effect is most pronounced among those fuels which contain catalytically cracked light cycle oils. Extraction of four test fuels, 70/30 blends of straight run stocks and light cycle oils, with aqueous base indicated that base extraction had little to no effect on insolubles formation. A fuel blending experiment, which involved blending several straight runs with various light cycle oils, implicates the catalytically cracked light cycle oils as primary repositories of the precursor materials which bring about the formation of insolubles. The methanol extract may serve as a chemical probe for the sediment precursors and may thus function as an indicator for instability under long term storage conditions.