[en] A dispersion-strengthened ferritic alloy is provided which has high-temperature strength and is readily fabricable at ambient temperatures, and which is useful as structural elements of liquid-metal fast breeder reactors. 4 tables

[en] A ferritic alloy has been found foruse in liquid metal fast breder reactors which not only has the desirable properties attributable to ferritic alloys but also has high temperature mechanical strength and is readily fabricable at ambient temperatures. It is a mechanically-alloyed dispersion-strengthened ferritic alloy which consists essentially of, by weight, about 13 percent to about 25 percent chromium, about 0.2 percent to less than 2 percent titaniu, up to 2 percent molybedenum, and up to about 1.5 percent of a refactory stable compound which may be a metal oxide, metal nitrate or metal carbide, preferably yttria. The balance, apart from residual elements, is essentially iron. The alloy is of uniform composition and has a high degree of dispersion uniformity. (LL)

[en] A historical review of conventional fractionation offers little confidence that such treatment is optimal for all tumors. Thus manipulation of time-dose schedules may provide a relatively inexpensive yet potentially useful technique for improving therapeutic results in radiation therapy. Consideration of basic radiobiological principles and animal model data illustrates the complex and heterogeneous nature of normal tissue and tumor response to time-dose effects and supports the hypothesis that better time-dose prescriptions can be found in clinical practice. The number of possible time-dose prescriptions is very large, and a review of the clinical trials using nonconventional fractionation demonstrates that the sampled portion of the total three-dimensional space of time, fraction number, and dose has been very small. Only carefully designed clinical trials can establish the therapeutic advantage of a new treatment schedule, and methods for selecting the most promising schedules are discussed. The use of simple data reduction formulas for time-dose effects should be discarded since they ignore the very complexity and heterogeneity of tissues and tumors which may form the basis of improved clinical results

[en] The collagen inhibitor D-penicillamine was evaluated as a potential radiation reaction preventive agent by studying its effect on deaths attributed to pulmonary damage in mice. Long-term administration of D-penicillamine at a rate of 100 mg/kg/day had no significant effect on the LD/sub 50/160/ in mice following pulmonary irradiation

[en] Studies to determine the structural and geohydrological properties of the Passaic Formation were performed at two sites. Both sites are located in northeastern New Jersey, within the Juro-Triassic-aged Newark Basin. The Passaic Formation rocks are described in the literature as a reddish brown, thin to massively bedded, sedimentary deposit with lithology ranging from claystone through conglomerate. A fractured open-quotes layer cakeclose quotes model has been proposed (and is generally accepted) to describe the prevailing geohydrological conditions. The Formation MicroScanner tool was used in four wells drilled for these projects (two at each site). In addition to this microresistivity tool, a suite of other oil field geophysical tools (Gamma, Induction, Dipmeter, Temperature, and Neutron probes) were also utilized. The data collected with the Formation MicroScanner were correlated with detailed logs and the continuous core retrieved from three of the wells. Pump test data was also obtained at both sites. The geophysical data obtained at both sites allowed the direct identification of fractures and their orientation in relation to bedding. Fracture and bedding aperture size and orientation were measured. The results, as presented in this paper, show a high degree of inhomogeneity at both sites rather than the conventional layer cake model. For appropriate site analyses it was necessary to significantly refine the previously assumed Passaic Formation geohydrological and structural model. 14 refs., 4 figs

[en] Cycloheximide is a known inhibitor of protein synthesis. When administered intraperitoneally to the rat, the drug protected against radiation-induced skin and structural damage to the hind limbs. It was maximally protective when given 12 to 24 hrs prior to single radiation doses

[en] The proliferative response of rat aortic endothelial cells following irradiation was measured using autoradiography of tritiated thymidine-labeled ''hautchen'' preparations. No increase in labeling index was observed for periods as long as 15 weeks following radiation doses of up to 2000 rad

[en] Beta-aminopropionitrile (BAPN), an inhibitor of collagen maturation, was tested as a radiation reaction preventive agent (RRPA) using radiation-induced lung fibrosis in rats and mice as a model. Following pulmonary irradiation, treatment with BAPN significantly prevented an increase in collagen content as measured by hydroxyproline analysis. This effect persisted during BAPN maintenance for periods of up to 10 weeks but was lost when the drug was discontinued. BAPN administration did not increase the mouse lung LD/sub 50/160/ in the drug doses employed in this study. Other possible RRPAs deserving further study include D-penicillamine and beclomethasone dipropionate

[en] The random nature of cell killing by ionizing radiations sets an upper limit on the steepness of the dose--response (D--R) curve for tumor cure. This theoretical limit was approached but not reached in a carefully controlled experimental system using experimental rat rhabdomyosarcomas. It would seem unlikely that this result could be achieved in clinical practice because of the potential importance of tumor heterogeneity and treatment error in decreasing the slope of the D--R curve. In attempting to achieve a high degree of precision in treatment administration, the therapist, particularly in a multitreatment course, is aided by certain statistical rules which are applicable to random errors. (auth)

No abstract available