Cooling rates of olivine xenocrysts in the EET79001 shergottite

The chemical zoning profiles of olivine xenocrysts in lithology A of the Elephant Moraine (EET) 79001 basaltic shergottite have been measured in order to investigate its cooling history. Olivines are zoned from Fa_ in the cores to Fa_ in the rims. The major and minor element compositions of olivine xenocryst cores in EET79001 correspond to those of homogeneous olivines in the lherzolitic shergottites, reconfirming the previous studies. We assume that the initial profile of olivine was uniform and it was modified by atomic diffusion due to contact with the Fe-rich surrounding melt when olivine was incorporated as a xenocryst. Comparing the observed Fe zoning profiles with the calculated ones, we have estimated the minimum cooling rates of the xenocrystic olivines by numerically solving the diffusion equation. The inferred minimum cooling rates (0.07-0.5℃) are faster than that for Zagami estimated from the width of pyroxene lamella, consistent with a hypothesis that EET79001 experienced significant undercooling unlike Shergotty and Zagami. We also performed the calculations by applying two different Fe-Mg interdiffusion coefficients to evaluate them. There is no significant difference in the curvature of the calculated profiles between the two diffusion coefficients, whereas one gives roughly fivefold higher cooling rates than the other

Mineralogical comparison of Hammadah al Hamra 126 with some ureilites

Hammadah al Hamra 126 (HAH 126) is a new ureilite recovered from the Sahara desert in 1995. This meteorite experienced fairly extensive weathering in the desert environment. Olivines in HAH 126 are more intensely reduced than those in other ureilites which have been studied to date. We have obtained a cooling rate of 0.1-0.7℃/hour for the reduction rims of olivines using diffusion calculations. This cooling rate is slightly slower than those for other ureilites. Rims of pigeonite grains in HAH 126 often show high-Ca contents. These Ca-rich materials resemble those which are present at olivine rims in Y-74123 ureilite. This fact suggests that Ca-rich melt was present at grain boundaries (H. OGATa et al.; Meteoritics, 25,195,1991)

Exsolved kirschsteinite in angrite LEW86010 olivine

Mineralogy of kirschsteinite exsolution in olivine from Antarctic meteorite LEW86010 has been studied by single crustal X-ray diffraction technique. The LEW86010 olivine crystals have exsolution lamellae of kirschteinite about 15 microns wide. Determination of crystallographic orientation of exsolved kirschsteinite in an olivine grain has been made. Weak reflections of exsolved kirschsteinite share common crystallographic orientation with the host olivine. The cell dimensions of the exsolved phase (a - 4.87 plus or minus 0.05A, b - 11.14 plus or minus 0.10A, c - 6.36 plus or minus 0.05A) and intensities were in well accord with those of kirschsteinite previously reported. Oriented section perpendicular to the a axis shows exsolution lamellae in two directions parallel to (031) and (031). The lamellae are up to 10 microns in width and spacings between them are usually 50-100 microns

Chemical zoning of olivines in the Yamato-791717 CO3 chondrite

The chemical zoning profiles of olivines in the Yamato (Y)-791717 CO3 chondrite have been analyzed in order to explore its thermal history. Two alternative models were applied to distinguish igneous processes from metamorphic features; they are fractional crystallization and diffusive modification of primary composition. It was clarified that chemical zoning of olivines in Y-791717 has been formed by a diffusion process, suggesting that this meteorite has been thermally metamorphosed. Thermal metamorphism of Y-791717 we have shown is consistent with that proposed on the basis of thermoluminescence investigation. A diffusion model also allows us to examine its thermal history in a quantitative way. Using a diffusion model, we have most successfully reproduced measured zoning profiles in isolated and chondrule olivine grains from Y-791717 in the temperature range 800-300℃. The temperature range is broadly consistent with the previously proposed peak metamorphic temperatures for CO3 chondrites

Neocarzinostatin effect on immune response of mice 1. Effects on humoral immunity

Since tumor-antitumor agent-host correlation must be considered in the treatment of neoplasms, the qualitative change of serum protein and hemolytic plaque forming cell (HPFC) production against sheep red blood cells (SRBC) in mice were carefully studied in part 1 to investigate the effect of a new antileukemic agent, Neocarzinostatin (NCS), on humoral immunity. Serum gamma globulin significantly decreased by the 4(th) day and returned to normal by the 12th day after a single injection of NCS. After 4 consecutive days of NCS administration gamma globulin value showed no change, but after 7 consecutive days of NCS 0.50mg/kg/day administration marked gamma globulin reduction was observed. Marked reduction of HPFC was observed in the -8(th) and -4(th) day groups of the single injection of NCS, but the -12(th), O, +2(nd) and +4(th) day groups showed only moderate reduction (Immunization by SRBC was done on 0 day.). After 4 consecutive days of NCS injection only 0.50mg/kg/day group showed HPFC reduction. But after 7 consecutive days of NCS administration 0.005mg/kg/day group showed moderate and 0.05mg/kg/day group showed marked reduction of HPFC. All mice in 0.50mg/kg/day group died. These data suggest that NCS suppresses the humoral immunity of mice to some extent and it affects almost all phases of the immune response but mainly the afferent phase. Furthermore, immunosuppressive effects of NCS are related to the daily dose and the number of consecutive days of NCS administration

Neocarzinostatin effect on immune response of mice 2. Effects on cellular immunity

In part 2 peripheral lymphocyte count, the total number of spleen cells, the weight and histology of the spleen, in vitro proliferative response of spleen cells to phytohemagglutinin (PHA) and delayed cutaneous hypersensitivity to picryl chloride were studied to see the effects of a new antileukemic agent, Neocarzinostatin (NCS), on the cellular immunity of mice. A single administration of NCS decreased the peripheral lymphocyte count, the spleen weight, the total number of spleen cells and in vitro proliferative response to PHA on the 4(th) and 8(th) day after NCS administration but its suppressive effects on these factors almost disappeared on the 12(th) day. NCS suppressed the delayed cutaneous hypersensitivity to picryl chloride and its suppressive effect was dependent on the daily dose of NCS. But its suppressive effect weakened after 10 days of drug free interval. The above data suggest that NCS suppresses the cellular immunity of mice to a certain degree and its immunosuppressive effects are dependent on the daily dose and the number of consecutive days of NCS administration, and on the days of drug free interval