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61.
62.
J. Gillman Christine Gilbert Isobel Spence 《Cellular and molecular life sciences : CMLS》1955,11(4):157-158
Zusammenfassung Die Entstehung von Reticulosarkom bei Ratten nach mehrmaliger Injektion von Trypanblau kann unterdrückt werden durch Entkräftung, Verabreichung anti-thyreoidaler Mittel und durch alle andern Faktoren, welche den Stoffwechsel herabsetzen. 相似文献
63.
Uncertain sinks in the shrubs 总被引:12,自引:0,他引:12
64.
Large-scale features of ocean circulation, such as deep water formation in the northern North Atlantic Ocean, are known to regulate the long-term physical uptake of CO2 from the atmosphere by moving CO2-laden surface waters into the deep ocean. But the importance of CO2 uptake into water masses that ventilate shallower ocean depths, such as subtropical mode waters of the subtropical gyres, are poorly quantified. Here we report that, between 1988 and 2001, dissolved CO2 concentrations in subtropical mode waters of the North Atlantic have increased at a rate twice that expected from these waters keeping in equilibrium with increasing atmospheric CO2. This accounts for an extra 0.4-2.8 Pg C (1 Pg = 10(15) g) over this period (that is, about 0.03-0.24 Pg C yr(-1)), equivalent to 3-10% of the current net annual ocean uptake of CO2 (ref. 3). We suggest that the lack of strong winter mixing events, to greater than 300 m in depth, in recent decades is responsible for this accumulation, which would otherwise disturb the mode water layer and liberate accumulated CO2 back to the atmosphere. However, future climate variability (which influences subtropical mode water formation) and changes in the North Atlantic Oscillation (leading to a return of deep winter mixing events) may reduce CO2 accumulation in subtropical mode waters. We therefore conclude that, although CO2 uptake by subtropical mode waters in the North Atlantic--and possibly elsewhere--does not always represent a long-term CO2 sink, the phenomenon is likely to contribute substantially to interannual variability in oceanic CO2 uptake. 相似文献
65.
Severe impairment of interleukin-1 and Toll-like receptor signalling in mice lacking IRAK-4 总被引:33,自引:0,他引:33
Suzuki N Suzuki S Duncan GS Millar DG Wada T Mirtsos C Takada H Wakeham A Itie A Li S Penninger JM Wesche H Ohashi PS Mak TW Yeh WC 《Nature》2002,416(6882):750-756
Toll-like receptors (TLRs), which recognize pathogen-associated molecular patterns, and members of the pro-inflammatory interleukin-1 receptor (IL-1R) family, share homologies in their cytoplasmic domains called Toll/IL-1R/plant R gene homology (TIR) domains. Intracellular signalling mechanisms mediated by TIRs are similar, with MyD88 (refs 5-8) and TRAF6 (refs 9, 10) having critical roles. Signal transduction between MyD88 and TRAF6 is known to involve the serine-threonine kinase IL-1 receptor-associated kinase 1 (IRAK-1) and two homologous proteins, IRAK-2 (ref. 12) and IRAK-M. However, the physiological functions of the IRAK molecules remain unclear, and gene-targeting studies have shown that IRAK-1 is only partially required for IL-1R and TLR signalling. Here we show by gene-targeting that IRAK-4, an IRAK molecule closely related to the Drosophila Pelle protein, is indispensable for the responses of animals and cultured cells to IL-1 and ligands that stimulate various TLRs. IRAK-4-deficient animals are completely resistant to a lethal dose of lipopolysaccharide (LPS). In addition, animals lacking IRAK-4 are severely impaired in their responses to viral and bacterial challenges. Our results indicate that IRAK-4 has an essential role in innate immunity. 相似文献
66.
67.
The Wood River sculpin Cottus leiopomus is endemic to the Wood River Basin in central Idaho and is a nongame species of concern because of its limited distribution. However, status and genetic population structure, 2 factors often central to the conservation and management of species of concern, have not been assessed for this species. We used backpack electrofishers to survey streams that were small enough (i.e., a priori to contain, possibly contain, or not contain the sculpin, respectively. Native redband trout Oncorhynchus mykiss gairdneri were present at 21 study sites, including 18 of the 20 sites that contained Wood River sculpin. Sixty-one study sites (60%) were dry or had too little water to contain any fish. We estimated that a minimum of 1.36 million Wood River sculpin (≥20 mm total length) currently reside in the basin. The presence of Wood River sculpin was positively associated with stream width:depth ratio and percent cobble/boulder substrate and negatively associated with stream gradient. Mitochondrial DNA haplotype differences were observed between and within the 3 major river subbasins supporting sculpin, with the most striking differences observed between populations in the Camas Creek subbasin and the other 2 subbasins, among which no haplotypes were shared, suggesting relatively long-term isolation. Our results suggest that the Wood River sculpin remains relatively widespread and abundant within its endemic range, despite obvious changes in historical stream connectivity caused by irrigation diversions and other chronic habitat alterations. 相似文献
68.
Many functionally important cellular peptides and proteins, including hormones, neuropeptides, and growth factors, are synthesized
as inactive precursor polypeptides, which require post-translational proteolytic processing to become biologically active
polypeptides. This is achieved by the action of a relatively small number of proteases that belong to a family of seven subtilisin-like
proprotein convertases (PCs) including furin. In view of this, this review focuses on the importance of privileged secondary
structures and of given amino acid residues around basic cleavage sites in substrate recognition by these endoproteases. In
addition to their participation in normal cell functions, PCs are crucial for the initiation and progress of many important
diseases. Hence, these proteases constitute potential drug targets in medicine. Accordingly, this review also discusses the
approaches used to shed light on the cleavage preference and the substrate specificity of the PCs, a prerequisite to select
which PCs are promising drug targets in each disease. 相似文献
69.
70.
Joan M. Lartin-Drake Joanne Gillis-Donovan Christine R. Curran Nancy R. Kruger James T. Ziegenfuss Jr. 《Systemic Practice and Action Research》1996,9(5):403-419
The first part of this two-part series described the initial impetus driving a university hospital's planned change project, the planning process itself, and the interventions that were identified to meet our goals. This article describes and discusses the interventions—the implementation of our version of Ackoff's circular organization and issues related to barriers, selected outcomes, the change process, evaluation, and the project's significance to nursing. 相似文献