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341.
A novel, potent and selective quinazolinone series of inhibitors of p38α MAP kinase has been identified. Modifications designed to address the issues of poor aqueous solubility and high plasma protein binding as well as embedded aniline functionalities resulted in the identification of a clinical candidate N-cyclopropyl-4-methyl-3-[6-(4-methylpiperazin-1-yl)-4-oxoquinazolin-3(4H)-yl]benzamide (AZD6703). Optimisation was guided by understanding of the binding modes from X-ray crystallographic studies which showed a switch from DFG 'out' to DFG 'in' as the inhibitor size was reduced to improve overall properties.  相似文献   
342.
Fine-scale spatial heterogeneity influences biodiversity and ecosystem productivity at many scales. In savanna systems, Macrotermes termites, through forming spatially explicit mounds with unique woody plant assemblages, emerge as important sources of such heterogeneity. Despite a growing consensus regarding the importance of functional diversity (FD) to ecosystem processes, no study has quantified how termite mounds affect woody plant FD. We address whether termite mounds alter the distribution of functional traits, and increase FD of woody plant communities within Africa’s largest savanna woodland, the 2.7 million km2 miombo system. Using plant traits that change according to soil resources (for example, water and nutrients), and disturbance (for example, fire and elephant herbivory), we identified response functional groups and compared relative representation of these groups between mound and matrix habitats. We also asked whether mound and matrix habitats differed in their contribution to FD within the system. Although species representing most functional groups were found in both mound and matrix habitats, relative abundance of functional groups differed between mound and matrix. Mound plant assemblages had greater response diversity to soil resources than matrix plots, but there was no difference in response diversity to disturbance. High trait values on mounds included tree height, leaf nitrogen, phosphorus, and palatability. Species with root ectomycorrhizae dominated the matrix. In conclusion, these small patches of nutrient-enriched substrate emerge as drivers of FD in above-ground woody plant communities.  相似文献   
343.
Safe drinking water and sanitation are important determinants of human health and wellbeing and have recently been declared human rights by the international community. Increased access to both were included in the Millennium Development Goals under a single dedicated target for 2015. This target was reached in 2010 for water but sanitation will fall short; however, there is an important difference in the benchmarks used for assessing global access. For drinking water the benchmark is community-level access whilst for sanitation it is household-level access, so a pit latrine shared between households does not count toward the Millennium Development Goal (MDG) target. We estimated global progress for water and sanitation under two scenarios: with equivalent household- and community-level benchmarks. Our results demonstrate that the “sanitation deficit” is apparent only when household-level sanitation access is contrasted with community-level water access. When equivalent benchmarks are used for water and sanitation, the global deficit is as great for water as it is for sanitation, and sanitation progress in the MDG-period (1990–2015) outstrips that in water. As both drinking water and sanitation access yield greater benefits at the household-level than at the community-level, we conclude that any post–2015 goals should consider a household-level benchmark for both.  相似文献   
344.
The determination of the history and causes of recent eutrophication and intensified thermal stratification in Lake Victoria is still hampered by the sparsity of paleolimnologic coverage of the enormous lake. Five new diatom records from Ugandan waters now show that a transition from Aulacoseira-dominated planktonic assemblages to those dominated by long Nitzschia spp., occurred in northern coastal sites from the mid-1970s to mid-1980s. Similar transitions developed from the late 1960s to early 1970s offshore and from the 1940s to early 1950s along the Kenyan coast, suggesting a time-transgressive process. These changes are not readily attributable to the trophic effects of Nile perch population growth during the early 1980s, but more likely reflect responses to long-term nutrient enrichment and climatic instability in the region. The diversity of planktonic diatom communities has declined dramatically, and a namesake variety of Aulacoseira nyassensis may now be nearly extirpated. Although local phytoplankton communities varied considerably in the past, the current domination of diatom assemblages by Nitzschia is apparently unprecedented in the 15,000-year history of Lake Victoria.  相似文献   
345.
There has arisen considerable interest in the study of dopamine D2/3 agonist binding sites by positron emission tomography (PET), based on the claim that agonist sites represent a functional subset of the total number of sites labeled by more conventional antagonist ligands. To test the basis of this claim, we used quantitative autoradiography to measure the abundance of binding sites of a dopamine D2/3 agonist ([3H]NPA) and an antagonist ([3H]raclopride) in cryosections of rat brain. Saturation binding studies revealed that the Bmax for [3H]NPA was nearly identical to that of [3H]raclopride in dorsal brain regions, but was 25% less in the ventral striatum and 56% less in the olfactory tubercle. We also tested the displacement of the two ligands by the hallucinogen LSD, which is known to have dopamine agonist properties. Whereas displacement of [3H]raclopride by increasing LSD concentrations was monophasic, displacement of [3H]NPA was biphasic, suggesting an action of LSD via a subset of dopamine D2/3 agonist binding sites. Addition of the stable GTP analogue Gpp(NH)p to the medium abolished 90% of the [3H]NPA binding, and increased [3H]raclopride binding by 10%, with a shift to the right in the LSD competition curve, suggesting retention of endogenous dopamine in washed cryostat sections. Thus [3H]NPA and [3H]raclopride binding sites have nearly identical abundances in rat dorsal striatum, but are distinct in the ventral striatum, and with respect to their displacement by LSD.  相似文献   
346.
347.
Gordon R. Cumming 《CMAJ》1974,111(8):818-821
While rheumatic fever is relatively uncommon except where there are poor and crowded living conditions, sporadic acute attacks continue to occur in a family or pediatric medical practice. The physician''s role in management of the sore throat in the diagnosis of suspected cases of rheumatic fever and in follow-up for continued prophylaxis is discussed. The frequency of admissions and presenting features of 159 patients with acute rheumatic fever is reviewed. Continued surveillance is required if we are to achieve a further reduction in attack rate and complications.  相似文献   
348.
349.
The technique of cyclic nucleotide fluorescence immunohistochemistry has been applied for the specific localization of cyclic GMP in rat cerebellum. We report immunofluorescence associated with fibres and membranes, contrasting with previously reported cytoplasmic localization of cyclic AMP in different cell populations, using a similar technique. We have been unable to detect changes in cyclic GMP staining in response to post-mortem changes, harmaline and pentobarbitone administration. A role of cyclic GMP is suggested in membrane ion transport.  相似文献   
350.
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