The driving force for liquid metal corrosion is the equilization of chemical potential for dissolution of all solid surfaces in contact with the liquid. In any practical system, this is an impossible goal; therefore, one observes several mass transfer processes.

Since the end of the last century (Tarknow, 1896) radiation effect o the nervous tissue has been studied in experimental animals and humans by numerous investigators, using mostly pathomorphological changes as a parameter of radiosensitivity . With increasing time intervals following radiation, pathomorphological changes are more evident, which has been known for quite some time.

In the summer of 1960 one of the little used wells on the Brookhaven National Laboratory site became accidentally contaminated with radioactive material. The contamination was discovered during a routine sampling of all wells in the waste disposal area, so there was a period of several weeks between the time of discharge.

Radiation and annealing mechanisms for dimensional and c-axis changes in which the di-interstitial can be mobile at any or all temperatures above absolute zero are shown to be concordant with earlier work used to determine the migration energy energy of single interstitials and the absolute rate of displacing atoms in graphite. The mechanisms account for the stability of c-axis and dimensional changes with time in the absence of irradiation and with observed c-axis annealing at room temperature following irradiation at low temperatures.

Electron-transfer reactions involving bridged transition states are examined from the point of view of adiabatic electron transfer theory. One important function of the bridging group is to decrease the effective dipole moment of the charge system of the reaction ions. The effect on the activation energy is different for outer-sphere and inner-sphere reactions. Trends in the halide and hydroxide catalysis of isotopic exchange reactions of transition metal ions are discussed.

Since 1940 it has been known that extra salt (i.e. sodium chloride) facilitated the development of experimental hypertension induced by various sterols; subsequently hypertension was induced by desoxycorticosterone acetate plus sodium chloride; then hypertension was produced by using hypertonic saline as the sole source of liquid; and finally, in 1953, Menesly and his associates reported that chronic ingestion of excess dietary salt alone would produce hypertension in rats. Furthermore, in conformity with general pharmacologic experience relating dose response to successive increments of a drug, as the average daily salt intake increased, the average systolic, blood pressure increased.

Kalanchoe seedlings were exposed to 330 r/20 hrs/day from a Co60 source. Samples were harvested weekly. No new leaves were produced after initial exposure to irradiation. Mitosis in the apical meristem appears to have been suppressed. However, the axillary meristem and the cambium continue their activity. This results in a much broadened stem tip with enlarged cells, supported by a stout internode in which cell size has remained relatively normal but cell number has increased. After about 26 days of exposure, meristematic activity in the shoot apex region appears to resume. This results in the formation of growth centers which can give rise to leaves or malformed structures. The original phyllotaxy is not recovered. It is suggested that this resumption of growth may be an instance of adaptation to irradiation.

This paper will first note briefly the place and status of radiobiotopical investigations with fast neutrons. The monoenergetic (fast) neutron technique employed at this laboratory will be then described and results of studies with various criteria-of-effect in the mouse will be reviewed. Finally, certain general patterns of response for these systems will be pointed out as functions of neutron energy.

It has been established by chromosome marker studies, histochemical, immunological, and cytological methods that the hemopoietic tissues of animals exposed to lethal doses of whole-body irradiation can be repopulated by transfused autologous, homologous or heterologous bone marrow cells. However, the morphology of the cell responsible for the regeneration of hematopoietic activity in the various hemopoietic organs has not been identified. It has been shown that the bone marrow contains the cell or cells capable of regenerating all types of hemopoietic tissues. In order to identify transfused cells, one must have a label which persists through successive divisions. Odell and Smith labeled the donors with S35 methionin and were thus able to follow the accumulation of the donor marrow cells in the recipients lungs and subsequently their releases to the bone marrow and spleen. However, this compound has a relatively rapid turnover in the labeled cells and thus a relatively limited capability of serial studies to observe mitosis and differentiation. Tritiated thymidine is ideal for this purpose since it is incorporated solely into DNA and is diluted only by mitosis. In addition the high resolution with tritium makes it certain that one is observing nuclear labeling. Bond et al. have studied …

Previous attempts by the present authors to compare the behavior of orally administered vitamin B12 with that of injected material have been inconclusive. Thus, 30 days after administration to normal humans, 0.19% of a tracer amount (0.5 μg) of injected radioactive vitamin B12 is excreted per day; and in an independent study, the eventual daily output was found to be 0.23% of a 3 μg dose. By contrast the total excretion rate of normal vitamin B12 from body stores appears to be only ≈0.03% per day. Such a divergence may result from incomplete mixing of radioactive vitamin B12 and body stores of the vitamin. Alternatively it may actually reflect the functioning of different compartments attending the several modes of administration involved. The possibility of degradation or transformation of vitamin within tissues and organs must also be considered.

Seven lysogenic strains - three of Rhizobium Leguminosarum and four of R-trifolii - were identified among a total of 54 strains from these two species and R. phascoli. The R. leguminosarum strain may be multiply lysogenic; two of them also produce lethal agents resembling bacteriocins in their effects. Lysogeny was confirmed by standard criteria of UV-inducibility, self-immunity, and reproductive ability. Lysogenic conversion involving symbiotic characteristics was not observed. A minimum of six different temperate phage were identified. The host range includes strains of the above three rhizobial species, but not of R. mclilotii. Variation in host specificity of some phage following host passage is under investigation.

It has been known for many years that bone growth may be retarded by relatively large doses of therapeutic radiation. Similar doses of radiation have also shown retarded growth in animals. More recently, reports of studies of Japanese children exposed to the Atomic Bomb Detentions at Hiroshima and Nagasaki and Marshallese children exposed to radiation in the fallout accident of 1954 have indicated some impairment in their growth and development, possibly related to radiation exposure. Since the doses of radiation received by these children were lower than would be expected to produce retardation of bone growth by direct irradiation, it was considered that indirect mechanisms might play a part. This preliminary report summarizes investigations of possible indirect effects of X-irradiation in bone growth in rats.

Our earlier in vitro studies have suggested that malignant tumors may not produce new cells more rapidly than normal cells are produced in the "steady state" equilibrium. Obviously tumors of all typed represent a diversion from "steady state" production with a net gain in mass of tissue. However, the increase in mass is not necessarily constant and may fluctuate in the natural history of the disorder. DNA labeling with tritiated thymidine had made it possible to characterize normal "steady state" hemopoietic growth parameters. We therefore thought it mandatory to extend these techniques to the study of growth rates of human leukemic cells. Also, since current therapy is more or less closely tied to a concept of unrestrained rapid growth, which we in part have begun to question, it appeared wise to look back at the historical development of knowledge about tumor growth. The existence of tumors in man has been known for millenia.

Previous investigations that the pancreas is a radioresistant organ. Ivy in 1924 noted the presence of a fibrotic atrophic pancreas in a dog which had received one erythema dose to the epigastrium. Fisher in 1923 reported that four to five erythema doses delivered in a single application caused complete disappearance of the irradiated pancreatic remnant in about two months. These dogs died because of uncontrolled diabetes. One dog that received four erythema doses (possibly 200 r) was sacrificed after five months. At autopsy the irradiated pancreas had disappeared, but 275 mgm of regenerated pancreas were found at the base of the main duct and 100 mgm at the base of the accessory duct. Leven in 1933 implanted radon seeds into the pancreas. Dosages varied from 528 to 1584 millicurie hours. At postmorten the pancreas surrounding the seeds demonstrated fibrous atropy and foci of necrosis. The islets appeared normal but were relatively larger in size. Rauch in 1952 reported that dogs given 200 r in air over the pancreas on alternate days until a total of 1600 r was received failed to show any histological changes after two months. Lushbaugh and Spalding and Lushbaugh reported that over 1500 r of whole-body …

Periodically irradiated and annealed graphites show property changes that are markedly different from the changes after the first irradiation and anneal. Evidence is presented indicating the existence of consecutive reactions between interstitial complexes that lead to steady state concentrations of the intermediate species in a chain. The steady state concentrations result in dimensional recoveries and stored energy releases that do not increase with irradiation as they do in continuously irradiated graphites. Interstitial complexes, formed by a thermal anneal, interact through an integral chain via mobile single interstitials. Kinetic equations of chains reacting at one or both ends are described. The calculations for chains reacting at both ends show that large complexes can decompose to form smaller ones. Experimental evidence supporting the calculations shows that periodic removal of the smaller complexes of large amounts of damage associated with the layer interstitials.

Recent reports (1, 2, 3, 4, 5) suggest that the crystalline structure of ice permits unusual forms of energy relationships and that the structured state of water may be of importance in the whole cell. A number of biologically interesting compounds show significantly altered responses to the excitation energy of ultraviolet light in ice as compared to the liquid state. This paper describes the effect of a change in phase state on a biologically active nucleoprotein, a bacteriophage particle. Phage is found to be much more sensitive to inactivation by ultraviolet light when irradiated in frozen aqueous suspension than when irradiated at room temperature (7): the sensitive target appears to be the phage DNA.

In the analysis of the effect of ionizing radiation on living systems, the problem is complicated by the interaction of one part of the system with other parts. If an entire mouse is subjected to radiation, only a few of the most radiosensitive organs, the "weak links," react to the insult and essentially limit the size of the dose delivered since there is little to be learned from irradiating a dead mouse. Thus an insensitive organ like muscle will not respond at all to a total body dose. Likewise, every organ is composed of several different kinds of cells, and the most radiosensitive cells in the organ will determine the reaction observed.

Cell proliferation on the actively growing periosteal surface of the femur of rabbits aged two weeks, has been investigated using autoradiographic techniques. Injections of tritiated glycine and tritiated thymidine were given simultaneously and the animals sacrificed at intervals from one hour to 5 days after injection. The glycine labelled the position of the bone surface at the time of injection and the thymidine labelled the cells which were synthesizing DNA . The rate of increase in the cell population was determined by counting the number of cells beyond the glycine label at different times after injection. The cell kinetics of the fibroblast--pre-osteoblast--osteoblast--osteocyte system has been studied. The fibroblasts are relatively unimportant from the point of view of increase in the cell population. The main site of cell proliferation is the layer of preosteoblasts on the periosteal surface. The rate of movement of cells from the pre-osteoblast to the osteoblast and osteocyte compartments has been measured. The incorporation of osteoblasts into the bone is not a random process, but it appears that the osteoblast must spend a certain time on the periosteal surface before becoming either an osteocyte or a relatively inactive osteoblast lining a haversian canal. During its most active …

A study of the cell kinetics on the actively growing periosteal surface of the femur of rabbits ages two weeks has been continues. A single injection of tritiated thymidine was given and the rabbits killed from one hour to four days after injection. The grain count spectra of the different cell types, pre-osteoblast, osteoblast and osteocyte, have been compared at different times after injection. The results showed evidence for the uptake of thymidine in nuclei which is not associated with cell division. A small percentage of osteoblasts was initially labelled at one hour and there was evidence that the majority of these had not divided by 3 or 4 days after injection. Some thymidine labelled cells had also become osteocytes without division. Furthermore, it appeared that a considerable fraction of the initially labelled pre-osteoblasts did not divide. The S-period for the pre-osteoblasts and osteoblasts was measured using a double-labelled thymidine technique.

The problem of separation of beams of particles of different masses but of the same momentum at Bev energies is the subject of a great deal of study at several high energy laboratories. In this note we shall describe the problem and tabulate a few of the cogent parameters. Frequently the student of high energy interactions is faced with a beam of miscellaneous particles coming from an accelerator. By standard techniques this beam can be rendered approximately parallel and an inch or so in diameter. By passage through a magnetic field the beam can be analyzed in momentum. Now it frequently happens that the particles in which the experimenter is particularly interested make up only a small fraction of the beam and the exigencies of the proposed experiment may well demand that the background of undesired particles be drastically reduced. The problem is difficult because the velocities of the various particles are almost equal to each other and to the velocity of lights; this makes time-of-flight techniques relatively ineffective. The energies of the particles are almost equal so electrostatic separation also is difficult. Since the beam is already analyzed in momentum, further separation by magnetic means is impossible.

Cowley's measurements of the short-range order parameters, αi, in Cu3Au at T=405°C have been re-evaluated taking into account the effects of thermal vibrations and static displacements due to differing atomic sizes. The separate corrections for the thermal vibrations and the first-neighbor atomic size factor are found to be quite large, demonstrating their importance in the usual experiments. When combined, the corrections in this case largely cancel, and only the values of α1 and α3 are appreciably changed. The corrected values are: α1= -.113, α2= +.185, α3= -.009, α4= +.082, α5= -.058.

An isochronal differential-type microcalorimeter has been designed and constructed. As a result of its simple design it is very easy to handle the samples and assemble the calorimeter. Important to the operation of the calorimeter is a program, also working on the differential principle, that provides linear temperature rise of the samples. This calorimeter is used to measure very small energy releases such as those found in precipitation, stored energy, etc. It is demonstrated that the calorimeter is easily capable of measuring 0.0005 cal with a probable error of the order of 1% to 2%.

The purpose of this paper is to present tables of the perturbed wave functions which have been recently obtained in a calculation of the quadruple antishielding factors γ∞ for the Mn+2, Fe+3, Ga+3, and Ag+ ions. The wave functions v'1(nℓ-ℓ) which are tabulated represent the effect of the perturbation due to a nuclear quadruple moment Q on the wave functions of the outermost electrons of the ion core.

For an experiment to measure the magnetic moment of the Λ hyperon, it was necessary to extract the external beam of the Cosmotron with maximum efficiency and with minimum time duration. To accomplish this end, the standard external beam of the machine was supplemented with the Rapid Beam Ejector. It was found that, unfortunately, the ejection efficiency of the beam was less than normal when the RBE was used. Measurements of the ejection efficiency were made by irradiating polyethylene foils at the second focus of Beam 1 with 3 BeV protons. The external beam was tuned up and optimized in a standard manner. It was found that the ratio of the number of protons ejected with the RBE to the number ejected without the RBE was 0.3 in one run and 0.22 in another try. It was also observed that the RBE did not shift the position of the external proton beam focus to within ± 1/8 in.