Spectrally resolved polarization angle across the motional Stark effect spectrum.

A new diagnostic technique has been developed that couples a spectrometer and an image-intensified camera into the traditional motional Stark effect (MSE) system on DIII-D. The image-intensified camera syncs with the photo-elastic modulators to spectrally resolve the Stokes parameters across the Stark multiplet. Polarization dependent phase shift, likely from a plasma facing mirror, leads to the spectropolarimeter measuring a variation in the polarization angle across the MSE spectrum of ∼8°.

Asymmetries in the motional Stark effect emission on the DIII-D tokamak.

Spectrometer measurements and filter upgrades to a motional Stark effect polarimeter measuring the outer half-radius of the DIII-D tokamak helped to identify asymmetries in the polarization angle of Stark-split emission. The measured polarization angle of the π components differs and is not orthogonal to the σ component. These differences persist over a range of densities and with low levels of background light. It is suggested that the difference in the polarization angle between components is from a change in the ellipticity of the emitted light across the Stark components coupled with imperfect polarization preservation from an in-vessel mirror.

A photoelastic-modulator-based motional Stark effect polarimeter for ITER that is insensitive to polarized broadband background reflections.

A motional Stark effect polarimeter insensitive to polarized broadband light is proposed. Partially polarized background light is anticipated to be a significant source of systematic error for the ITER polarimeter. The proposed polarimeter is based on the standard dual photoelastic modulator approach, but with the introduction of a birefringent delay plate, it generates a sinusoidal spectral filter instead of the usual narrowband filter. The period of the filter is chosen to match the spacing of the orthogonally polarized Stark effect components, thereby increasing the effective signal level, but resulting in the destructive interference of the broadband polarized light. The theoretical response of the system to an ITER like spectrum is calculated and the broadband polarization tolerance is verified experimentally.

Plasma lipid profiles and antihypertensive agents: effects of lisinopril, enalapril, nitrendipine, hydralazine, and hydrochlorothiazide.

Previous studies have documented potentially adverse effects of diuretics and beta-blocking agents on plasma lipid profiles. This study was designed to establish the effects on lipid profiles of the angiotensin-converting enzyme inhibitors lisinopril and enalapril, alone and in combination with hydrochlorothiazide (HCTZ), the calcium-channel blocker nitrendipine, HCTZ, and hydralazine. After a two-week, single-blind, placebo phase, 77 patients with essential hypertension were given active agent as monotherapy in a double-blind fashion for 8-20 weeks. The dose of each agent was titrated to achieve diastolic blood pressure less than 90 mm Hg. At the end of placebo and treatment phases, plasma was analyzed for triglycerides, total cholesterol, and high-(HDL), and low-density lipoprotein (LDL) cholesterol. Overall, few changes in lipid contents were noted. Total cholesterol decreased during therapy with hydralazine but increased in patients receiving the combination of lisinopril and HCTZ. HDL cholesterol was depressed in those taking HCTZ alone and in combination with lisinopril. LDL cholesterol was lowered during therapy with hydralazine but was otherwise unaffected by all other agents. None of the agents evaluated significantly affected triglyceride concentrations. Thus, monotherapy with lisinopril, enalapril, and nitrendipine do not affect plasma lipid concentrations. Hydralazine lowers total and LDL cholesterol. If these findings are confirmed in trials with larger numbers of patients, these effects on lipid profiles may influence choice of agent in the therapy of essential hypertension.

Lisinopril versus lisinopril plus hydrochlorothiazide in essential hypertension.

The efficacy of a new angiotensin converting enzyme inhibitor, lisinopril, used alone (group A) was compared with lisinopril plus hydrochlorothiazide (group B) in 26 patients with essential hypertension. Therapy with both regimens was equally effective in lowering blood pressure compared to placebo. Mean antihypertensive dose of lisinopril was lower when given in combination with hydrochlorothiazide than when given alone (48 +/- 6 vs 68 +/- 12 mg daily). Plasma renin activity increased in both groups of patients, but more in group B (p less than 0.05). Plasma aldosterone concentrations and serum uric acid levels were also higher in the group receiving lisinopril plus hydrochlorothiazide (p less than 0.05). Serum potassium concentrations were unaffected in either group. The incidence of side effects was similar in groups A and B (44% and 38%, respectively). This study suggests that lisinopril alone or in combination with hydrochlorothiazide effectively lowers blood pressure in patients with essential hypertension without any major side effects.