Thermoluminescence study of ordinary chondrites by TL spatial distribution readout system

The thermoluminescence (TL) image reading technique by the TL spatial distribution readout system is improved 1) to obtain a quantitative glow curve in any part of the TL image, 2) to get fine structure of a TL image and 3) to heat a sample to a higher temperature. This technique is applied to measure the natural and artificial TL glow curves of chondrules in ordinary chondrites, ALH-77294 (H5) and ALH-77216 (L3.8). The fluctuation in the natural LT/HT (region) ratios (LT(region); photons counted in a low temperature region, HT (region); in a high temperature region) of the equilibrated chondrite ALH-77294 is small though that in the unequilibrated chondrite ALH-77216 is large. The equivalent doses of ALH-77294 and ALH-77216 can be estimated from the correlation between natural LT (region) and artificial LT (region) to be about 240krad and 16krad respectively, and are consistent with isotopic ages

金属/ゲルマニウム界面におけるフェルミレベルピンニングの研究

学位の種別: 論文博士審査委員会委員 : （主査）東京大学教授 鳥海 明, 東京大学教授 渡邉 聡, 東京大学教授 近藤 高志, 東京大学教授 木村 薫, 千葉大学教授 中山 隆史University of Tokyo(東京大学

FFC Ceramic Water(TM) Enhances Plant Apyrase Activity

The FFC ceramics(TM) from FFC Japan Co., Ltd. are now widely used in the fields of agriculture, fishery and food industry in Japan. Recently the FFC ceramic beads-based technology has been also applied to meet several environmental problems including pollution in sea, lakes and rivers. In this study the FFC ceramic water was tested for effect on plant enzyme, potato apyrase (EC 3.6.1.5; ATP-diphosphohydrolase), which hydrolyses nucleoside triphosphate (NTP) and -diphosphate (NDP) to produce corresponding nucleoside monophosphate (NMP) and inorganic phosphate (Pi). Addition of the FFC ceramic water to the enzyme reaction mixture markedly enhanced ATP-hydrolyzing activity, when used as ATP as substrate. However, the concomitant presence of Ca(2+) chelator, EGTA (O,O'-bis(2-aminoethyl)ethyleneglycol-N,N,N',N'-tetraacetic acid) with the FFC ceramic water, completely abolished the enzyme activation. In fact, exogenous calcium ion such as CaSO4 mimicked the FFC ceramic water. These results indicate that apyrase activation by the FFC ceramic water largely depends on calcium ions. On the other hand, when the FFC ceramic water prepared from "used" ceramics was tested for the apyrase activity, the enhanced effect on apyrase was decreased compared to the FFC ceramic water from "new" ones. This result, consistent with our present data covering concentration of calcium ions and conductivity, indicates that long and/or successive usage of the ceramic beads results in decrease of contents of released minerals, especially calcium ions. The apyrase-based enzyme assay presented here is probably applicable to estimate and quantify the effect of FFC ceramic water.本報は，FFC セラミックス(TM)（㈱エフエフシー・ジャパン）で調製した FFC セラミック水（FFC 水）の植物アピラーゼ（EC 3.6.1.5）の活性に及ぼす直接的な作用について調べたものである．FFC 水はアピラーゼがもつ ATP加水分解活性を促進し，その作用は反応液への添加量に依存した．先の無機元素分析結果から，FFC 水に含まれる主要な塩類はCa(2＋)であることが判明している．そこで，Ca(2＋)キレート剤EGTAを反応液へ加え，その影響について調べたところ，FFC 水による活性化作用は消失することが明らかとなった．また，FFC 水と類似の作用は，硫酸カルシウム，塩化カルシウムまたは硝酸カルシウムの添加で認められ，陰イオンの種類によって明確な違いはなかった．これらの結果から，FFC 水が植物アピラーゼに及ぼす活性化作用の一因は，セラミックスから遊離する Ca(2＋)に依存しているものと推察された．一方，アピラーゼ活性を指標として，使用済のセラミックスから調製した FFC 水の効果について検討したところ，未使用からの水と比べて，カルシウム濃度ならびに活性化作用の顕著な低下が認められた．このことは，継続的な使用によってセラミックスから遊離する塩類，特にカルシウムの溶出量が大きく変わることを意味し，アピラーゼを用いた本検定が，FFC 水の効果を定量的に確かめる方法の一つとして利用できると考えられた．以上，これらの結果を総合して，FFC水の植物酵素への直接的作用，ならびに植物への施用によって効果が現れる耐病性獲得作用との関連について考察した

Thermoluminescence characteristics and chemical compositions of mesostases in ordinary chondrites

Induced thermoluminescence (TL) images of ordinary chondrites, ALH-77214 (L3.4-3.5), Y-74191 (L3.6), ALH-77216 (L3.8) and ALH-78043 (L6), were measured by the TL spatial distribution readout system combined with a microscope and TL characteristics [peak temperature and peak width] of mesostases were analyzed. Their chemical compositions were also analyzed by an electron probe X-ray microanalyzer. We found that; (1) The mesostasis was responsible for much of the TL in the ordinary chondrites, (2) A mesostasis of normative anorthite compositions showed low peak temperature (∿90℃) and narrow width (∿65℃), while a mesostasis of normative albite compositions showed high peak temperature (∿125℃) and wide width (∿100℃), (3) A main phosphor in a low petrologic grade chondrite 3.5 was a high albite mesostasis, (4) Some chondrules in the same fragments of the type 3 chondrites showed no or weak TL emission and these mesostases had high normative albite. These facts suggest that in type 3 ordinary chondrites; (1) The post-accretional metamorphism cannot account for the coexistence of high albite mesostases with TL emission and no emission and a high anorthite mesostasis with TL emission, (2) Low petrologic grade chondrites 3.5 have a large population of slowly cooled chondrules

Thermoluminescence of chondrules in primitive ordinary chondrites,Semarkona and Bishunpur

The spatial distribution of the induced thermoluminescence (TL) and TL glow curves of the primitive ordinary chondrites, Semarkona (LL3.0) and Bishunpur (LL3.1), were investigated over a wide range of wavelengths using a TL spatial distribution readout system. Although bulk samples of Semarkona and Bishunpur have very low TL sensitivity, individual chondrules show a wide variety of induced TL intensity and glow curve shape. Chondrules with anorthite-normative mesostases have especially high induced TL intensity, and their TL is produced at wavelengths >480nm, compared with <480nm for the sensitivity range of the usual TL measuring systems. Some of the metamorphism-dependent TL sensitivity of type 3 ordinary chondrite therefore results in changes in the spectrum of the light produced

Effects of pulsing procedure of interleukin-12 in combination with interleukin-2 on the activation of peripheral blood lymphocytes derived from patients with hepatocellular carcinoma.

In patients with hepatocellular carcinoma (HCC), natural killer (NK) cell activity decreases significantly, and the reduced activity may be associated with the progression of HCC. In this study we evaluated the effects of pulsing with interleukin (IL)-2 and/or IL-12 on the activation of freshly isolated peripheral blood lymphocytes (PBL) derived from patients with HCC. PBL obtained from 9 HCC patients, 4 liver cirrhosis patients, and 9 normal subjects were cultured in the presence of IL-2 and/or IL-12. After 24 h of incubation, the levels of interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha presented in the supernatants were determined by enzyme-linked immunosorbent assay (ELISA). The IFN-gamma and TNF-alpha production of PBL pulsed by a combination of IL-2 and IL-12 was significantly higher than those of PBL stimulated by either IL-2 or IL-12 alone. The mRNA encoding perforin, granzyme B, as well as IFN-gamma and TNF-alpha, were markedly enhanced in PBL stimulated with a combination of IL-12 and IL-2. The pulsing procedure of IL-12 in combination with IL-2 resulted in the increase of IFN-gamma and TNF-alpha, and the expression of perforin and granzyme B mRNA in PBL obtained from HCC patients, as well as in those obtained from normal subjects. These results indicate that adoptive immunotherapy based on PBL pulsed with a combination of IL-2 and IL-12 may be a promising adjunctive strategy for HCC treatment.</p

Suppressive effects of transforming growth factor-beta1 produced by hepatocellular carcinoma cell lines on interferon-gamma production by peripheral blood mononuclear cells.

Transforming growth factor-beta1 (TGF-beta1) exerts potent immunosuppressive effects. In this study, we investigated the potential role of TGF-beta1 produced by hepatocellular carcinoma (HCC) cell lines in immunosuppression mechanisms. Using the Mv1Lu cell-growth inhibition assay and an enzyme-linked immunosorbent assay (ELISA), we detected optimal levels of TGF-beta1 in the culture supernatants conditioned by the HCC cell lines PLC/PRF/5, Hep3B, and HepG2. To determine the biological activity of TGF-beta1 in the supernatants, we examined the effects of the culture supernatants on the production of interferon (IFN)-gamma induced during the culture of peripheral blood mononuclear cells (PBMCs) stimulated with interleukin (IL)-12. IFN-gamma production of IL-12-stimulated PBMCs in the 1:1 dilution of the acid-activated conditioned medium of PLC/PRF/5, Hep3B, and HepG2 reduced to 14.7 +/- 0.8, 17.3 +/- 9.0, and 35.9 +/- 14.6%, respectively, compared with the value in the culture with control medium (complete culture medium). These results suggest that HCC cells producing TGF-beta1 may reduce the generation or activation of cytotoxic T lymphocytes (CTL) and natural killer (NK) cells, and thus could enhance their ability to escape immune-mediated surveillance.</p