Implementation of focused ion beam (FIB) system in characterization of nuclear fuels and materials.

Beginning in 2007, a program was established at the Idaho National Laboratory to update key capabilities enabling microstructural and micro-chemical characterization of highly irradiated and/or radiologically contaminated nuclear fuels and materials at scales that previously had not been achieved for these types of materials. Such materials typically cannot be contact handled and pose unique hazards to instrument operators, facilities, and associated personnel. Over the ensuing years, techniques have been developed and operational experience gained that has enabled significant advancement in the ability to characterize a variety of fuel types including metallic, ceramic, and coated particle fuels, obtaining insights into in-reactor degradation phenomena not achievable by any other means. The following article describes insights gained, challenges encountered, and provides examples of unique results obtained in adapting dual beam FIB technology to nuclear fuels characterization.

An unusual case of Wilson's disease.

A man of 61 with a 26-year history of progressive cerebellar ataxia was admitted to hospital. He was found to have chronic liver disease and died 22 days after admission. A diagnosis of hepatolenticular degeneration (Wilson's disease) was supported by clinical investigations and confirmed at autopsy, when tissue copper studies were performed. Several unusual features were present, including a unilateral Kayser-Fleischer ring, a hepatocellular carcinoma, peripheral neuropathy, pontine demyelination and calcification of neurones in the medulla. The significance of these findings is discussed with a review of the relevant literature.

The management of acute thermal injuries to the upper extremity.

In summary, although thermal injuries of the upper extremity can produce permanent functional compromise, intelligent management of burns of the hands and fingers can produce fully functional and cosmetically acceptable hands. When the dorsal aspects of the hands alone are injured by thermal insult, the immediate excision of the burned tissue and replacement by split-thickness skin grafts will produce functional and esthetically satisfying results. Should immediate excision and grafting be contraindicated because of massive burns of the body, management by application of topical antibacterial agents and dressings is possible. With this treatment, carefully supervised exercises are mandatory. Revisions of hypertrophic and contracted scars can be done at a later date. The stiff and painful hand is not the direct consequence of thermally destroyed skin, but is due instead to the metabolic and biologic complications of unhealed burn wounds. It follows, therefore, that the burn illness should preferably be terminated by prompt excision of the eschar and wound closure by the application of split-thickness skin grafts.

Septicaemia in the elderly.

A retrospective study was made of 44 elderly patients with bacteraemia treated in the period 1974-1980. Positive blood cultures in 5 cases were considered clinically insignificant. Twenty-six of the remaining 39 patients were found to have a Gram-negative bacteraemia, mainly associated with urinary tract infection. Abnormalities of liver function were common but 5 jaundiced patients with Gram-negative infection were shown to have stones in the common bile duct. The value of blood cultures as a diagnostic aid in the non-specifically ill elderly patient is emphasized.

Administration of beta-aminopropionitrile to human beings with urethral strictures: A prelimary report.

(1) No toxic signs or symptoms and no unusual laboratory determinations were observed in five patients with posterior urethral strictures treated by dilatation of the urethra and administration of 1 gm per day of beta-aminopropionitrile (BAPN) for twenty-one days. (2) Patients treated with 1 gm daily of BAPN for twenty-one days showed an increase in cold saline-extractable and acid-extractable collagen in proplast sponge-collected and dermal scar tissue comparable with that reported previously after doses of 3 to 5 gm of BAPN daily. (3) Significant reduction in the breaking strength of newly synthesized connective tissue was observed in patients treated with BAPN. (4) None of the patients in this study showed abnormalities in net collagen synthesis or in synthesis of noncollagenous protein. (5) The difference in the results of this study and two previous trials of BAPN in human beings which were discontinued because of toxic and or hypersensitivity signs and symptoms is hypothesized to be the result of development of highly purified BAPN fumarate.

Soft tissue response to Proplast: quantitation of scar ingrowth.

We compared, histologically and biochemically, the effects of blood pretreatment vs. no pretreatment on the ingrowth of scar into subcutaneously implanted blocks of Proplast in rats. No significant differences were found.

Morphologic aspects of experimental esophageal lye strictures. II. Effect of steroid hormones, bougienage, and induced lathyrism on acute lye burns.

Among 77 dogs surviving standardized transmural esophageal lye injury for at least 2 weeks and as long as 12 weeks, 24 were untreated, 26 received corticosteroids and bougienage (S&B), and 27 received only the lathyrogen beta-aminoproprionitrile (BAPN). Stricture frequency was reduced markedly and significantly in the S&B and BAPN groups when compared to the controls (p less than 0,01). Strictures resulted from inward circumferential remodeling of all mural layers, not proliferating bulky scar tissue, and persistent ulceration was apparently not an influential factor in any group. The S&B dogs invariably showed reduction of the internal or mucosal length of the injured segment as compared to the outer length; these relations were quite variable in the other two groups so that mean internal shortening was significantly greater (p less than 0.01) in the S&B group. Marked mural thinning in the injured zone was present in all three groups but was most frequent in the BAPN-treated animals. The major conclusion is that BAPN-induced changes in the physical properties of reparative tissue can increase the ultimate caliber of an injured hollow viscus without resort to mechanical bougienage. In addition, the data suggest that wound contraction may play a role in stricture formation in this model.

Soft tissue response to blood-impregnated Proplast.

The effects of Proplast implants on the soft tissues of rats were studied. The effects from Proplast implants which had been impregnated with blood, plasma, or saline were compared to the effects from implants which had received no pretreatment. No significant differences were found.

Presence of modified fibroblasts in ischemic contracture of the intrinsic musculature of the hand.

Biopsies of fibrotic interosseous muscles were obtained from three patients with ischemic contracture of the intrinsic muscles of the hand. Control biopsies were taken from normal contralateral interossei and from normal interossei crushed three weeks earlier. Examination of the specimens from the affected muscles under the electron microscope demonstrated large numbers of modified fibroblasts with ultrastructural features of both fibroblasts and smooth muscle cells. The atypical fibroblasts observed resembled myofibroblasts seen in contracting wounds, Dupuytren's contracture, stenosing tenosynovitis, and idiopathic carpel tunnel syndrome. Biopsies from normal muscle and crushed normal muscle contained normal fibroblasts and smooth muscle cells but no modified fibroblasts. Active contraction of modified fibroblasts could be responsible for progressive muscle shortening seen in intrinsic contracture.