This paper investigates a particular type of wormhole. The wormhole solutions studied are obtained by sewing together two static, spherically symmeric, charged black-hole metrics at their horizons. The charged wormholes are in a background Kalb-Ramond field, which is the source of the necessary tension in the gravitational field. The metric-tensor elements are studied by numerically solving Einstein's equations with stress-energy-tensor elements given by the combination of static electric and Kalb-Ramond fields. For a certain range of electric charge the tension is positive away from the wormhole throat, but the tension is negative near the throat, making it nontraversable. The wormholes are found to be quasistable against decay via gravitational instanton tunneling.

The statistical mechanics of a gas of Einstein-Kalb-Ramond wormholes is studied in this paper. The wormholes studied are the result of sewing together two Reissner-Nordstrom-type black hole metrics at their horizons. By requiring the stress-energy tensor associated with this geometry to be that of a Kalb-Ramond field, we obtain the mass and Kalb-Ramond `charge` of the wormholes in terms of the parameters describing the mass density, tension and pressure. We investigate the statistical mechanics of this system of wormholes within the context of the statistical bootstrap model. A gas of such wormholes is found to obey the bootstrap condition only for an extreme, non-thermodynamic, energy and `charge` distribution among the particles. We comment briefly on the scattering of quantum wormholes.

An ultrasound nebuliser with variable delivery temperature and nebulisation volume was tested for particle size distribution, efficiency, and application in a clinical environment. The results obtained comply with our criteria for a general purpose radioaerosol generating system for use in evaluating various parameters of lung function.

The recommended protocol for Tc99m tetrofosmin myocardial imaging suggests either a one- or two day imaging protocol so that stress and rest studies are sufficiently separated in time to allow optimum myocardium to background uptake ratios to differentiate between myocardial ischaemia and/or infarction. The biokinetic data for tetrofosmin suggest that no significant changes occur in myocardial distribution up to 180 minutes post injection. It is, therefore, necessary for two doses of the radiopharmaceutical and two separate studies to evaluate the myocardial status during stress and rest. This study assessed the differences between the 1 and 4 hour post injection SPET images obtained following peak exercise in 20 consecutively chosen patients. In addition, these images were compared to the rest images obtained on the following day after a second dose of the radiopharmaceutical was administered. In 4 patients, a one and four hour post injection study was also done during the rest phase. The results demonstrate significant changes in Tc-99m tetrofosmin distribution between the one hour and four hour post injection images. These differences are present during the stress as well as rest studies.

s of the British Nuclear Medicine Society Autumn Meeting: DUBLIN, 10 - 11 DECEMBER 1992: SESSION 3: LUNG AND ORGANIZATION: PDF Only

The impact of the new tau decay data on the various $τ$ puzzles and on the possibility of approximate supersymmetry is discussed. The most economical solution of the problems in $τ$ decay and that favored by recent new data supports the existence of gluinos below one GeV.

Summary: As the myocardial carnitine content, a key control factor in myocardial oxidative metabolism and energy transfer, is reduced in heart failure, administration of L-propionylcarnitine (LPC), a potent analogue of L-carnitine, potentially may improve cardiac function, possibly through a positive inotropic effect. As its hemodynamic profile is unknown in humans, 32 fasting normotensive patients with coronary artery disease received either 15 mg/kg of LPC (n = 16) or vehicle (mannitol/acetate, n = 16) infused over 5 min. Hemodynamic, radionuclide [peak ejection and filling rates (PER and PFR, respectively)], and metabolic variables (myocardial O2, lactate, and carnitine uptake) were studied at baseline and 1, 3, 5, 10, 15, and 45 min post drug. The baseline ejection fraction was depressed in LPC patients (40 ± 3% vs. 48 ± 4% in the vehicle group, p < 0.05) as a result of a significant high incidence of previous infarctions. Immediately following LPC, the cardiac total carnitine uptake changed from 102 ± 181 to 5,335 ± 1,761 μmol/L (p < 0.05). In both groups, left ventricular systolic and end-diastolic pressures increased significantly by 5 and 20%, respectively, during the first 5 min. In the vehicle group, contractility decreased by 5%, accompanied by a significant 11% fall in the stroke volume. In contrast, following LPC, isovolumetric contractility indices remained unaltered. Instead, both the PER and PFR improved by 16% at 45 min. Moreover, the cardiac output increased by 8%. LPC did not affect systemic or coronary hemodynamics. Lactate uptake increased by 42%, but myocardial O2 consumption did not change. Thus, despite the negative inotropic effects of its vehicle, LPC improves myocardial contractility and relaxation and cardiac pump function in patients with pre-existing ventricular dysfunction. As neither O2 consumption nor demand are affected, but instead glycolysis improves, LPC may be potentially useful in ischemic cardiomyopathy.

L'agence internationale sur l'energie atomique a organise une reunion consultative pour definir les criteres de base du controle de qualite des radiomedicaments produits par cyclotron et pour etablir les principes de leur manipulation. Ce controle de qualite est rendu necessaire pour assurer l'efficacite et l'inocuite des preparations juste avant leur administration

The stability of 99mTc-DTPA (diethylenetriamine-pentaacetic acid) and 99mTc-HIDA (2,6-diethylacetanilido-iminodiacetic acid) were evaluated following ultrasonic nebulisation. The results confirm that either of these radiopharmaceuticals can be used in our nebuliser without significant radiochemical breakdown.

The worst case radiation dose to tissue due to inadvertent intravenous injection of a radiopharmaceutical was estimated for the most commonly utilised radioisotopes. The probability of radiation injury induction was examined for the various radionuclides considering the maximal specific activity values encountered in diagnostic practice. A possible approach to the management of incidents involving extravasal activity deposition is discussed.

Pulmonary mean transit time was assessed in 32 patients. A significant difference in this parameter is demonstrated between normals and those patients who have received radiotherapy.

A composite filter has been developed to reduce the extraneous effects of photopeak imaging whereby a significant improvement in contrast resolution is achieved.

First-pass left ventricular ejection fraction was determined in 21 patients using 195mAu. The technical aspects of the application are discussed with particular reference to the thin crystal (1/4 in.) gamma camera. The use of diverse catheter types and combinations were also investigated so that optimal administration of the radionuclide could be achieved.

The recent review of pancreas scintigraphy by Agnew et al. (1976) serves to emphasize how much this procedure Upper left: lower border of liver visualized with 99Tcm phytate. Lower left: 75Se-L-selenomethionine scintigram with liver, pancreas and intestinal accumulation of activity. Upper right: visualization of proximal small intestine and stomach with oral 99Tcm colloid. Lower right: superposition of colloid scintigram on selenium scintigram to demonstrate intestinal selenium uptake and localize pancreas associated activity.

The recent review of bone-scanning reagents by Merrick (1975) raises a number of points with regard to technetium polyphosphate complexes which are open to discussion. Whilst it is reported that phosphates labelled with 32P or chelated with 51Cr localize in bone, the fact that 51Cr phosphate chelates accumulate in bone to a greater extent than non-chelated phosphates is overlooked (Anghileri and Miller, 1971).