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131.
Mariner 9 and Viking spacecraft images revealed that the polar regions of Mars, like those of Earth, record the planet's climate history. However, fundamental uncertainties regarding the materials, features, ages and processes constituting the geologic record remained. Recently acquired Mars Orbiter Laser Altimeter data and Mars Orbiter Camera high-resolution images from the Mars Global Surveyor spacecraft and moderately high-resolution Thermal Emission Imaging System visible images from the Mars Odyssey spacecraft permit more comprehensive geologic and climatic analyses. Here I map and show the history of geologic materials and features in the north polar region that span the Amazonian period (approximately 3.0 Gyr ago to present). Erosion and redeposition of putative circumpolar mud volcano deposits (formed by eruption of liquefied, fine-grained material) led to the formation of an Early Amazonian polar plateau consisting of dark layered materials. Crater ejecta superposed on pedestals indicate that a thin mantle was present during most of the Amazonian, suggesting generally higher obliquity and insolation conditions at the poles than at present. Brighter polar layered deposits rest unconformably on the dark layers and formed mainly during lower obliquity over the past 4-5 Myr (ref. 20). Finally, the uppermost layers post-date the latest downtrend in obliquity <20,000 years ago. 相似文献
132.
T-cell-mediated regulation of osteoclastogenesis by signalling cross-talk between RANKL and IFN-gamma 总被引:44,自引:0,他引:44
Takayanagi H Ogasawara K Hida S Chiba T Murata S Sato K Takaoka A Yokochi T Oda H Tanaka K Nakamura K Taniguchi T 《Nature》2000,408(6812):600-605
133.
Inhibitory PAS domain protein is a negative regulator of hypoxia-inducible gene expression. 总被引:28,自引:0,他引:28
Y Makino R Cao K Svensson G Bertilsson M Asman H Tanaka Y Cao A Berkenstam L Poellinger 《Nature》2001,414(6863):550-554
134.
K. Mizoguchi M. Tanaka H. Yokoo M. Yoshida A. Tsuda 《Cellular and molecular life sciences : CMLS》1992,48(11-12):1133-1134
The effect of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) on dopamine (DA) release and metabolism in the striatum was studied in freely moving rats by intracerebral microdialysis techniques. The DA level as well as the levels of 3,4-dihydroxyphenylacetic acid and homovanillic acid were significantly decreased 140 min after the administration of L-threo-DOPS (50 mg/kg intraperitoneally). The results suggest that L-threo-DOPS inhibits the release and metabolism of DA in the striatum. 相似文献
135.
S Shiozawa K Shiozawa S Shimizu Y Tanaka I Morimoto Y Kuroki R Yoshihara T Fujita 《Experientia》1989,45(8):764-765
A sensitive radioimmunoassay showed that circulating alpha-interferon in the plasma of healthy individuals was low in children and reached the highest level in the young adult, then declined gradually with age. Circulating alpha-interferon was 0.201 +/- 0.059 ng/ml in males (n = 19) and 0.184 +/- 0.076 ng/ml in females (n = 14) at ages 30-39 years old. It was noted that circulating alpha-interferon was maintained up to a certain level even in elderly individuals. 相似文献
136.
During diapause O2 consumption in fly pupae is a cyclic event (4-day periodicity at 25 degrees C) driven by cycles of juvenile hormone activity. Levels of juvenile hormone esterase activity change systematically during the cycle, with highest activity observed at the nadir of the O2 consumption cycle. 相似文献
137.
A novel and sensitive noncompetitive enzyme immunoassay for kassinin is described. Kassinin was biotinylated using sulfosuccinimidyl-6-(biotinamido)hexanoate. The biotinylated kassinin was trapped on anti-kassinin IgG-coated polystyrene balls and, after washing to eliminate other biotinylated substances, was eluted with HCl. The biotinylated kassinin eluted was reacted with anti-kassinin Fab'-peroxidase conjugate and trapped onto streptavidin-coated polystyrene balls. Peroxidase activity bound to the polystyrene balls was assayed by fluorimetry. The detection limit of kassinin was 0.13 pg (0.1 fmol)/tube or 0.065 microgram/l of rat plasma, which was 750-fold or 15-fold lower than that for competitive radioimmunoassay. 相似文献
138.
K. Saito H. Ohkura T. Kashima H. Katanasako H. Tanaka 《Cellular and molecular life sciences : CMLS》1982,38(3):359-360
Summary Decreased resting potential and prolonged duration of the action potential were observed in left ventricular muscles of dystrophic mice, while there was no change in myocardial potassium content.This study was supported in part by a Research Grant for Cardiomyopathy from the Ministry of Health and Welfare, Japan. 相似文献
139.
Summary An endogenous, heat-stable inhibitor of high mol. wt (approximately 3×105) was found to be present in rat brain, which inhibited Ca2+-dependent neutral protease specifically but not due to its binding of Ca2+ in the medium. 相似文献
140.
Gel filtration of antral extract of adult rats revealed gastrin-17 and gastrin-34. Gel filtration of anterior pituitary extract showed CCK8 and gastrin-17, whereas posterior pituitary extract showed only a CCK8. Antral gastrin-like immunoreactivity (G-LI) increased after milk feeding and especially after weaning was started. Changes in diet may exert a profound influence on the ontogenic development of antral G-LI, but not pituitary CCK8/G-LI. 相似文献