Magnetic-field effects on the size of vortices below the surface of NbSe2 detected using low energy beta-NMR.

A low energy radioactive beam of polarized 8Li has been used to observe the vortex lattice near the surface of superconducting NbSe2. The inhomogeneous magnetic-field distribution associated with the vortex lattice was measured using depth-resolved beta-detected NMR. Below Tc, one observes the characteristic line shape for a triangular vortex lattice which depends on the magnetic penetration depth and vortex core radius.

beta-NMR of isolated lithium in nearly ferromagnetic palladium.

The temperature dependence of the frequency shift and spin-lattice relaxation rate of isolated, nonmagnetic (8)Li impurities implanted in a nearly ferromagnetic host (Pd) are measured by means of beta-detected nuclear magnetic resonance (beta-NMR). The shift is negative, very large, and increases monotonically with decreasing T in proportion to the bulk susceptibility of Pd for T > T* approximately 100 K. Below T*, an additional shift occurs which we attribute to the response of Pd to the defect.

Near-surface structural phase transition of SrTiO3 studied with zero-field beta-detected nuclear spin relaxation and resonance.

We demonstrate that zero-field beta-detected nuclear quadrupole resonance and spin relaxation of low energy (8)Li can be used as a sensitive local probe of structural phase transitions near a surface. We find that the transition near the surface of a SrTiO(3) single crystal occurs at T(c) approximately 150K, i.e.

Depth-controlled beta-NMR of 8Li in a thin silver film.

Depth-controlled beta-NMR can be used to probe the magnetic properties of thin films and interfaces on a nanometer length scale. A 30 keV beam of highly spin-polarized 8Li+ ions was slowed down and implanted into a 50 nm film of Ag deposited on a SrTiO3 substrate. A novel high field beta-NMR spectrometer was used to observe two well resolved resonances which are attributed to Li occupying substitutional and octahedral interstitial sites in the Ag lattice.

Glycogen storage: illusions of easy weight loss, excessive weight regain, and distortions in estimates of body composition.

Glycogen is stored in the liver, muscles, and fat cells in hydrated form (three to four parts water) associated with potassium (0.45 mmol K/g glycogen). Total body potassium (TBK) changes early in very-low-calorie diets (VLCDs) primarily reflect glycogen storage.

Long-term outcome of a self-help very-low-calorie-diet weight-loss program.

This paper presents 90-wk data on five seriously overweight subjects originally brought together for 1-2 wk in simple residential accommodation to share the experience of beginning a program of very-low-calorie dieting. All subjects have remained well below their starting weight; four of the five subjects have continued to lose weight (weight losses 33.7-66.

Across-the-day monitoring of mood and energy intake before, during, and after a very-low-calorie diet.

Mood, hunger, and energy intake were monitored in eight obese women before, during, and after 2 wk on a very-low-calorie diet (VLCD). Energy intake was significantly lower by approximately 30% in the week after the VLCD compared with the prediet week, both from food diaries and at a controlled ad libitum test meal. There was a gradual reduction in hunger, irritability, and urge to eat after 1 wk on the VLCD, which persisted through the postdiet week.

Changes in total body nitrogen during weight reduction by very-low-calorie diets.

Body composition measurements, including total body nitrogen (TBN) by in vivo neutron activation analysis, were made on 11 female volunteers before and after an 11-wk very-low-calorie diet (VLCD) [1695 kJ (405 kcal) 6.7 g N]. Mean body mass index (BMI) changed from 32.

Dependence of weight loss during very-low-calorie diets on total energy expenditure rather than on resting metabolic rate, which is associated with fat-free mass.

The assumption that total energy expended is related to resting metabolic rate (RMR) has not been validated. Intuitively, weight lost should be determined by the difference between the total energy consumed and the total energy expended. The ratio of actual daily energy usage to RMR by subjects dieting for 11 wk on a 1695-kJ (405-kcal) very-low-calorie diet (VLCD) was variable 1.

Factors influencing body composition during very-low-calorie diets.

Apparent body composition changes with weight loss on very-low-calorie diet (VLCD) can depend on the method of fat-free mass estimation. In this report the implications of differences in measurement by direct versus indirect methods are examined. The nitrogen sparing and protein economy associated with ketosis is relevant and results of clinical trials with diets of varying composition are presented.

Effect of diet-induced weight loss on total body bone mass.

1. Total body areal bone mineral density was measured by dual-energy X-ray absorptiometry in eight women before and 10 weeks after a very-low-calorie diet [405 kcal (1701 kJ)/day]. 2.

Effect of very low calorie diet on body composition and exercise response in sedentary women.

The effect of very low calorie diet (VLCD) on fat-free mass (FFM) and physiological response to exercise is a topic of current interest. Ten moderately obese women (aged 23-57 years) received VLCD (1695 kJ.day-1) for 6 weeks.

Effect of changes of water and electrolytes on the validity of conventional methods of measuring fat-free mass.

Fat-free mass was measured by hydrodensitometry, electrical impedance and total body potassium before and after water and electrolyte loss induced by (a) the administration of the diuretic frusemide, and (b) sweat loss. All methods of measuring fat-free mass were shown by pilot experiments to have procedural reliability. The diuretic caused a reduction in apparent fat-free mass of 2.