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This paper examines the life and work of T. C. Chamberlin, a prominent glacial geologist who developed an interest in interdisciplinary earth science. His work on the geological agency of the atmosphere informed his understanding of climate change and other terrestrial phenomena and led him to propose a new theory of the formation of the Earth and the solar system.Chamberlin's graduate seminar at the University of Chicago in 1896 contained all the themes that informed his research programme over the next three decades. These included the carbon dioxide theory of climate change in its relationship to diastrophism and oceanic circulation, the role of water vapour feedbacks in the climate system, and the relationship between multiple glaciations, the climate system, and the formation of the planet.  相似文献   

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To study the origins of biologically active substances in marine sponges, a carotenoid produced by a marine bacterium,Pseudomonas sp. strain number KK10206C, which was associated with a marine sponge,Halichondra okadai, was investigated. A visible absorption spectrum-guided isolation procedure led to the isolation of a novel C50-carotenoid, okadaxanthin. Its structure, 2,2-bis(4-hydroxy-2-methyl-2-butenyl)-,-carotene, was elucidated mainly by spectroscopic methods. Okadaxanthin turned out to be a potent singlet oxygen quencher, approximately 10 times as strong as -tocopherol.  相似文献   

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Spinach leaf mitochondria (C3 plant) were capable of oxidizing Glycine. This oxidation was linked to the mitochondrial electron transport chain, was coupled to three phosphorylation sites and was sensitive to electron transport inhibitors. In marked contrast however, neither mitochondria from dark grown plants nor mitochondria from C4 leaf plants were capable of oxidizing this amino acid.  相似文献   

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Zusammenfassung Die Synthese von Arginin-Vasopressin, Lysin-Vasopressin und Oxytocin, deren Glycinrest eine14C-Markierung trägt, wird mit Hilfe der Festkörpermethode nachMerrifield beschrieben.

Supported by National Institutes of Health grants No. AM-13567 and No. AM-10080 and the Atomic Energy Commission.

Abbreviations follow the rules of the IUPAC-IUB Commission on Biochemical Nomenclature in Biochemistry5, 2485 (1966). All optically-active amino acids are ofl-configuration. The following additional abbreviations were used: N-hydroxysuccinimide ester (OSu), ethanol (EtOH), methanol (MeOH), acetic acid (AcOH),n-butanol (n-BuOH), pyridine (Pyr) and N,N-dicyclohexylcarbodiimide (DCCI). Protected peptides and hormones were visualized on thinlayer plates according to the procedure byH. Zahn andE. Rexroth, Z. analyt. Chem.148, 181 (1955). The biological activities of the hormones were measured against the U.S.P. Posterior Pituitary Reference Standard; the four-point design was used for these bioassays and standard errors were calculated according to the method ofC. I. Bliss,The Statistics of Bioassay (Academic Press, New York, N.Y. 1952).

Acknowledgments. The authors wish to thank Mr.D. Schlesinger for some of the amino acid derivatives used, and MissM. Wahrenburg and Mrs.A. Silverman for bioassays.  相似文献   

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Summary The structure of a new linear C21 furanoterpene, furospongolide (1), obtained from the marine spongeDysidea herbacea, was determined by spectral means.We thank Professor J. Vacelet for the identification and Dr Loya and Mr Benayahu for the collection of the sponge.  相似文献   

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Summary The predominant host-selective toxin fromCochliobolus victoriae, victorin C, is a peptide with an apparent mol. wt of 796, representing a cyclic array of the subunits1–6. The structure of the toxin has now been established as in16 through analysis of the degradation products generated by enzymic and non-enzymic partial hydrolysis. The presence of a hydrated aldehydo group requires for victorin C the composition C31H45O13N6Cl3 with an amended mol. wt of 814, for which independent experimental support has been secured.  相似文献   

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Summary The structure of furodendin (5), a minor secondary metabolite of the spongePhyllospongia dendyi, has been solved by spectral methods. Furodendin is probably derived, biosynthetically, by elimination of a C3 unit from a C25 geranyl-farnesol precursor.Acknowledgment. We thank Dr C. Evans for sponge identification, RRIMP Museum number FN 1516/000.  相似文献   

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The effect of interleukin 1β (IL-1β), interferon γ (IFN-γ), tumor necrosis factor α (TNFα) and lipopolysaccharide (LPS) on the expression of the C2 and C3 genes in human adherent monocytes was studied. Stimulation of monocytes with IFN-γ increased both C2 and C3 mRNA. IL-1β also increased C2 mRNA level, whereas C3 gene expression was not enhanced. TNFα failed to increase either C2 or C3 mRNA. LPS increased C2 mRNA, but suppressed C3 gene expression. These results suggest that C2 and C3 production by monocytes is regulated by IL-1β and IFN-β in the local tissues.  相似文献   

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Zusammenfassung In narkotisierte Katzen wurde C14-Histamin entweder durch Hirnventrikel perfundiert oder intravenös injiziert. Seine Ausscheidung und Metabolite in Urin wurde gleichzeitig bestimmt: Ca. 2% des durch die Hirnventrikel perfundierten C14-Histamins wurde im Blutstrom resorbiert.  相似文献   

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We have previously shown that the protein kinase C (PKC) system plays a pivotal role in regulation of proliferation and differentiation of the human keratinocyte line HaCaT which is often used to assess processes of immortalization, transformation, and tumorigenesis in human skin. In this paper, using pharmacological and molecular biology approaches, we investigated the isoform-specific roles of certain PKC isoenzymes (conventional cPKC and ; novel nPKC and ) in the regulation of various keratinocyte functions. cPKC and nPKC stimulated cellular differentiation and increased susceptibility of cells to actions of inducers of apoptosis, and they markedly inhibited cellular proliferation and tumor growth in immunodeficient mice. In marked contrast, cPKC and nPKC increased both in vitro and in vivo growth of cells and inhibited differentiation and apoptosis. Our data present clear evidence for the specific, antagonistic roles of certain cPKC and nPKC isoforms in regulating the above processes in human HaCaT keratinocytes.Received 13 January 2004; received after revision 18 February 2004; accepted 25 February 2004  相似文献   

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H Shimizu  T Sakano  A Fujie  S Nishimura  K Ueda 《Experientia》1992,48(11-12):1148-1150
The effect of interleukin 1 beta (IL-1 beta), interferon gamma (IFN-gamma), tumor necrosis factor alpha (TNF alpha) and lipopolysaccharide (LPS) on the expression of the C2 and C3 genes in human adherent monocytes was studied. Stimulation of monocytes with IFN-gamma increased both C2 and C3 mRNA. IL-1 beta also increased C2 mRNA level, whereas C3 gene expression was not enhanced. TNF alpha failed to increase either C2 or C3 mRNA. LPS increased C2 mRNA, but suppressed C3 gene expression. These results suggest that C2 and C3 production by monocytes is regulated by IL-1 beta and IFN-gamma in the local tissues.  相似文献   

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Zusammenfassung Zwei Ochratoxinanaloge, Ochratoxin TA (OTA) und TC (OTC) wurden aus Ochratoxin- chemisch synthetisiert indem Phenylalanin und sein Äthylester im Molekül durch Tyrosin und Tyrosinäthylester substituiert wurden. Der Hühnerembryonentest ergab, dass OTC etwas toxischer und OTA etwas weniger toxisch ist als Ochratoxin A (OA).  相似文献   

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Synthesis of ochratoxins TA and TC, analogs of ochratoxins A and C   总被引:1,自引:0,他引:1  
R D Wei  F S Chu 《Experientia》1974,30(2):174-175
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Summary The use of13C spin-lattice relaxation measurements as a probe of structure in solution is illustrated for flexibilide. Analysis of quaternary carbon relaxation behaviour indicates that the structure in solution differs from the crystal structure. The effects of lanthanide shift and relaxation reagents on13C spectral parameters are also reported.Acknowledgment. We thank R.J. Wells, RRIMP, for helpful discussions.  相似文献   

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