Development of the large neutron imaging system for inertial confinement fusion experiments.

Inertial confinement fusion (ICF) requires a high resolution (~10 µm) neutron imaging system to observe deuterium and tritium (DT) core implosion asymmetries. A new large (150 mm entrance diameter: scaled for Laser MégaJoule [P. A. Holstein, F. Chaland, C. Charpin, J. M. Dufour, H. Dumont, J. Giorla, L. Hallo, S. Laffite, G. Malinie, Y. Saillard, G. Schurtz, M. Vandenboomgaerde, and F. Wagon, Laser and Particle Beams 17, 403 (1999)]) neutron imaging detector has been developed for such ICF experiments. The detector has been fully characterized using a linear accelerator and a (60)Co γ-ray source. A penumbral aperture was used to observe DT-gas-filled target implosions performed on the OMEGA laser facility. [T. R. Boehly, D. L. Brown, R. S. Craxton, R. L. Keck, J. P. Knauer, J. H. Kelly, T. J. Kessler, S. A. Kumpan, S. J. Loucks, S. A. Letzring, F. J. Marshall, R. L. McCrory, S. F. B. Morse, W. Seka, J. M. Soures, and C. P. Verdon, Opt. Commun. 133, 495 (1997)] Neutron core images of 14 MeV with a resolution of 15 µm were obtained and are compared to x-ray images of comparable resolution.

The pathologic physiology of chronic Bright's disease. An exposition of the "intact nephron hypothesis".

Clinical and experimental data relating to the functional capacity of the surviving nephrons of the chronically diseased kidney for the most part support the thesis that these nephrons retain their essential functional integrity regardless of the nature of the underlying form of chronic Bright's disease. There are instances in which specific alterations of function correlate with pathologic involvement of a particular site of the nephron but these appear to represent the exceptions, and in general the more advanced the disease becomes, the less evident are the differentiating features. Studies on dogs with unilateral renal disease indicate that the functional capacity of the nephrons of the diseased kidney parallels that of the nephrons of the contralateral normal kidney. These data tend to exclude widespread intrinsic damage to the functioning nephrons by the underlying pathologic processes. From these observations, as well as from certain supporting clinical and experimental observations, it is suggested that the majority of surviving nephrons in the patient with bilateral renal disease similarly are functionally intact. Concepts of the pathologic physiology of the kidney, based on the "intact nephron hypothesis", are presented. Within the framework of this hypothesis it is concluded that (1) the diseased kidney consists of a diminished number of nephrons, most of which retain essentially normal functional abilities; (2) certain of the apparent abnormalities in function in bilateral renal disease may relate to adaptive changes imposed by the decreased nephron population and the attendant derangements in body fluids rather than to structural distortion of nephrons; (3) the over-all flexibility of the diseased kidney decreases as the number of constituent nephrons decreases; but (4) there is an orderly and predictable pattern of excretion for all substances.

Use of a comprehensive programme of external cueing to enhance procedural memory in a patient with dense amnesia.

This case study describes rehabilitation efforts with a 24-year-old woman who exhibited dense amnesia secondary to status epilepticus following a motor vehicle accident. She was 20 months post-injury upon entry into our day treatment programme. The functional severity of her amnesia was reflected in numerous ways, including no recall of what she wore from day to day and an inability to find the toilet after 2 weeks in the programme. A multidisciplinary comprehensive programme of external cueing was established to exploit her preserved procedural memory. Objective measures of functional compliance were gathered over time and contrasted with both standard neuropsychological test scores and early levels of functioning in rehabilitation. Results demonstrated enhanced functioning via utilization of procedural memory. In addition, the patient actually demonstrated increased independent generalization of strategies and techniques over time. Practical treatment implications are reviewed and discussed.

Fatal airway obstruction caused by a mucous ball from a transtracheal oxygen catheter.

A 50-year-old man with pulmonary fibrosis and COPD presented with worsening cough, dyspnea, chest pain, and hypoxemia of no readily apparent etiology, approximately four weeks after insertion of a transtracheal oxygen therapy catheter. Despite vigorous bronchial hygiene therapy, the patient died. Autopsy revealed obstruction of the trachea by a large mucous ball. We point out the nonspecificity of physical and radiologic findings associated with this condition and suggest that serial flow-volume loop analysis or earlier use of fiberoptic bronchoscopy might have been of assistance in premortem diagnosis of the mucous plug.