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41.
Meisch H. -U. Kessler M. Reinle W. Wagner A. 《Cellular and molecular life sciences : CMLS》1986,42(5):537-542
Summary Annual rings of 140–160-year-old beeches (Fagus sylvatica) from St. Ingbert, Saarland (FRG) were prepared and analyzed for 14 metals by atomic absorption spectroscopy. According to the chronological variations of their concentrations, the elements could be divided into three groups: 1) Metals without any tendency for chronological changes. This was established for Na, K, Cu, Cr, Co, Ni, Pb, and Cd. 2) Metals with a recent decrease of their concentrations, appropriate for Ca, Mg, Mn, and Zn. 3) Metals with a recent tendency to increase, e.g. Fe and Al. These variations are discussed in connection with the industrial history of the Saarland region and the influence of acid immissions which may alter the soil and thereby the trace element metabolism of the trees with consequences for the vitality of the plants. 相似文献
42.
Zusammenfassung Kollodiumpartikel wurden mit Extrakten aus menschlichen Organen, wie Leber, Nieren und Myocard, sensibilisiert und damit Sera von Personen getestet, die an Krankheiten mit autoimmunisierenden Vorgängen in der Pathogenese litten. Die Ergebnisse dieser Versuche wurden mit denjenigen von Kontrollsera verglichen. 相似文献
43.
Bonardi V Pesaresi P Becker T Schleiff E Wagner R Pfannschmidt T Jahns P Leister D 《Nature》2005,437(7062):1179-1182
Illumination changes elicit modifications of thylakoid proteins and reorganization of the photosynthetic machinery. This involves, in the short term, phosphorylation of photosystem II (PSII) and light-harvesting (LHCII) proteins. PSII phosphorylation is thought to be relevant for PSII turnover, whereas LHCII phosphorylation is associated with the relocation of LHCII and the redistribution of excitation energy (state transitions) between photosystems. In the long term, imbalances in energy distribution between photosystems are counteracted by adjusting photosystem stoichiometry. In the green alga Chlamydomonas and the plant Arabidopsis, state transitions require the orthologous protein kinases STT7 and STN7, respectively. Here we show that in Arabidopsis a second protein kinase, STN8, is required for the quantitative phosphorylation of PSII core proteins. However, PSII activity under high-intensity light is affected only slightly in stn8 mutants, and D1 turnover is indistinguishable from the wild type, implying that reversible protein phosphorylation is not essential for PSII repair. Acclimation to changes in light quality is defective in stn7 but not in stn8 mutants, indicating that short-term and long-term photosynthetic adaptations are coupled. Therefore the phosphorylation of LHCII, or of an unknown substrate of STN7, is also crucial for the control of photosynthetic gene expression. 相似文献
44.
Porco CC Baker E Barbara J Beurle K Brahic A Burns JA Charnoz S Cooper N Dawson DD Del Genio AD Denk T Dones L Dyudina U Evans MW Fussner S Giese B Grazier K Helfenstein P Ingersoll AP Jacobson RA Johnson TV McEwen A Murray CD Neukum G Owen WM Perry J Roatsch T Spitale J Squyres S Thomas P Tiscareno M Turtle EP Vasavada AR Veverka J Wagner R West R 《Nature》2005,434(7030):159-168
Titan, the largest moon of Saturn, is the only satellite in the Solar System with a substantial atmosphere. The atmosphere is poorly understood and obscures the surface, leading to intense speculation about Titan's nature. Here we present observations of Titan from the imaging science experiment onboard the Cassini spacecraft that address some of these issues. The images reveal intricate surface albedo features that suggest aeolian, tectonic and fluvial processes; they also show a few circular features that could be impact structures. These observations imply that substantial surface modification has occurred over Titan's history. We have not directly detected liquids on the surface to date. Convective clouds are found to be common near the south pole, and the motion of mid-latitude clouds consistently indicates eastward winds, from which we infer that the troposphere is rotating faster than the surface. A detached haze at an altitude of 500 km is 150-200 km higher than that observed by Voyager, and more tenuous haze layers are also resolved. 相似文献
45.
A Toll-like receptor recognizes bacterial DNA 总被引:225,自引:0,他引:225
Hemmi H Takeuchi O Kawai T Kaisho T Sato S Sanjo H Matsumoto M Hoshino K Wagner H Takeda K Akira S 《Nature》2000,408(6813):740-745
DNA from bacteria has stimulatory effects on mammalian immune cells, which depend on the presence of unmethylated CpG dinucleotides in the bacterial DNA. In contrast, mammalian DNA has a low frequency of CpG dinucleotides, and these are mostly methylated; therefore, mammalian DNA does not have immuno-stimulatory activity. CpG DNA induces a strong T-helper-1-like inflammatory response. Accumulating evidence has revealed the therapeutic potential of CpG DNA as adjuvants for vaccination strategies for cancer, allergy and infectious diseases. Despite its promising clinical use, the molecular mechanism by which CpG DNA activates immune cells remains unclear. Here we show that cellular response to CpG DNA is mediated by a Toll-like receptor, TLR9. TLR9-deficient (TLR9-/-) mice did not show any response to CpG DNA, including proliferation of splenocytes, inflammatory cytokine production from macrophages and maturation of dendritic cells. TLR9-/- mice showed resistance to the lethal effect of CpG DNA without any elevation of serum pro-inflammatory cytokine levels. The in vivo CpG-DNA-mediated T-helper type-1 response was also abolished in TLR9-/- mice. Thus, vertebrate immune systems appear to have evolved a specific Toll-like receptor that distinguishes bacterial DNA from self-DNA. 相似文献
46.
夏海峰 《淮阴师范学院学报(自然科学版)》2002,1(4):14-16
本文指出仪洪勋和Brosch G在具有三个判别的CM公共值的亚纯函数的唯一性定理中,关于对数函数的导数是整函数的推导,可以用指数函数求导的方法来证明.改进了仪洪勋和Brosch G关于重值与唯一性定理. 相似文献
47.
A. Wagner N. Fortier A. Giroux J. Lukes L. M. Snyder 《Cellular and molecular life sciences : CMLS》1979,35(5):681-682
Summary Patients with iron deficiency whether uncomplicated or associated with other types of anemias, had plasma catecholamine levels which were significantly increased above normal controls. Patients with a variety of other anemias had no significant increase in catecholamine levels. Plasma catecholamine levels in uncomplicated iron deficient patients approached normal values as early as 3 h following oral FeSO4.Acknowledgment. Funded in part by an NIH grant No. R01 HL 19933. 相似文献
48.
A severe potentiating effects of methyl-ethyl-ketone (MEK) on the peripheral and central neurotoxicity of n-hexane could be demonstrated in a chronic inhalation study in rats. 相似文献
49.
V. Wagner V. Zavázal D. Kasalová V. Malý A. Mecl J. Prokop 《Cellular and molecular life sciences : CMLS》1959,15(1):24-25
Résumé On a contrôlé des femmes enceintes, atteintes d'éclampsie et, chez un groupe d'entre elles, la présence d'autoanticorps contre le placenta, le foie, les reins et le myocarde. On a constaté un taux significativement plus éleyé d'autoanticorps chez les femmes dont la grossesse a été compliquée d'éclampsie. 相似文献
50.