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91.
Synovial tissue of patients with rheumatoid arthritis (RA) spontaneously produces several cytokines, of which a fundamental
role in joint inflammation and destruction has been established. However, the factors sustaining this phenomenon remain poorly
understood. In a recent report, blockade of Toll-like receptor 2 (TLR2) was found to inhibit the spontaneous release of inflammatory
cytokines by intact RA synovial explant cultures. Adding to the recent evidence implicating other TLRs (in particular, TLR4),
this observation highlights the potential of TLRs as therapeutic targets to suppress the local production of multiple cytokines
and to control the chronic inflammatory loop in RA. 相似文献
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Beebe X Darczak D Henry RF Vortherms T Janis R Namovic M Donnelly-Roberts D Kage KL Surowy C Milicic I Niforatos W Swensen A Marsh KC Wetter JM Franklin P Baker S Zhong C Simler G Gomez E Boyce-Rustay JM Zhu CZ Stewart AO Jarvis MF Scott VE 《Bioorganic & medicinal chemistry》2012,20(13):4128-4139
A novel 4-aminocyclopentapyrrolidine series of N-type Ca(2+) channel blockers have been discovered. Enantioselective synthesis of the 4-aminocyclopentapyrrolidines was enabled using N-tert-butyl sulfinamide chemistry. SAR studies demonstrate selectivity over L-type Ca(2+) channels. N-type Ca(2+) channel blockade was confirmed using electrophysiological recording techniques. Compound 25 is an N-type Ca(2+) channel blocker that produces antinociception in inflammatory and nociceptive pain models without exhibiting cardiovascular or motor liabilities. 相似文献
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F C Rodrigues AJ JúniorHojaij I L Calvo C F de Carvalho 《Gegenbaurs morphologisches Jahrbuch》1987,133(4):665-672
50 dissections of the human inferior V. cava have been performed in order to measure its right renal vein - diaphragm, retrohepatic, and suprahepatic segments. We conclude that some individual parameters as skin type, age, height, weight did not influence the magnitude of the studied segments. The average measurements of the different parameters proposed for the inferior V. cava are: 1. The distances between the right renal vein and the diaphragm and between the right renal vein and the right atrium are 113.94 mm and 135.16 mm, respectively; 2. the length of the retrohepatic portion of the inferior V. cava and the suprahepatic one were 78.34 mm and 19.34 mm respectively; 3. the valve of the inferior V. cava is present in 46% of the observations; its length and width averages are 31 mm and 10.22 mm, respectively. 相似文献
96.
Much of community-ecology theory describes (or even assumes) constraints on the coexistence of species. These constraints are often described using functional characters as an index to the niche of the species. The hypothesis/assumption is that those species which are too similar in functional characters, and hence in niche, cannot coexist. However, this body of theory is rarely tested. We attempted a test by making a prediction of texture convergence that follows logically from the theory, yet is simple enough to test – one based on similarity of ecological assembly between the patches of a community. We used replicate quadrats within twelve herbaceous communities. Eleven characters were measured, that were intended to reflect the functional above-ground niche of the species. We examined each character in turn, to test for ecological convergence to a similar mean within each community, with species either weighted equally (i.e. using species presence) or weighted by their biomass. Convergence with species weighted by their biomass was seen in chlorophyll content, indicating a significant tendency for each patch in a community to comprise a rather constant mixture of species types in terms of their different chlorophyll contents. In terms of species presence, texture divergence occurred in leafiness (LAR), specific leaf area (SLA) and leaf inclination, i.e. there was more variation between quadrats within a site than expected at random. However, significant results were sparse: the bulk of evidence is for no significant departure from a null model, i.e. no support for a widespread body of ecological theory. 相似文献
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Mir Muhammad Nizamani AJ Harris XiaLan Cheng ZhiXin Zhu Chi Yung Jim HuaFeng Wang 《Ecology and evolution》2021,11(17):12204
Within urban green spaces, tree species diversity is believed to correlate with aboveground biomass, though there is some disagreement within the literature on the strength and directionality of the relationship. Therefore, we assessed the relationship between the biodiversity of woody species and the aboveground biomass of woody plant species in the tropical, coastal city of Haikou in southern China. To accomplish this, we obtained comprehensive tree and site data through field sampling of 190 urban functional units (UFUs, or work units) corresponding to six types of land uses governmental‐institutional, industrial‐commercial, park‐recreational, residential, transport infrastructure, and undeveloped area. Based on our field data, we investigated the relationship between tree species diversity and aboveground biomass using multiple regression, which revealed significant relationships across all five types of land uses. Aboveground biomass in green spaces was also correlated with anthropogenic factors, especially time since urban development, or site age, annual maintenance frequency by human caretakers, and human population density. Among these factors, maintenance is the strongest predictor of aboveground biomass in urban green space. Therefore, this study highlights the critical role of maintenance of urban green space in promoting both aboveground biomass and woody biodiversity in urban ecosystems and, consequently, on urban ecosystem services. Our findings contribute to a deeper understanding of the ecosystem services provided by communities of woody plant species in urban areas. 相似文献
100.
Here, we review progress and prospects to explicitly test for long distance dispersal biogeographic events. Long distance dispersal represents a “jump” across some kind of barrier, such as a topographic feature or a zone of unsuitable climate and may include repeated jumps, or stepping‐stone dispersals. Long distance dispersals were considered integral for explaining the organization of biodiversity at large and small scales by early biogeographers, such as Darwin and Wallace. Darwin, Wallace, and others envisioned that long distance dispersals were predictable events because the vectors for dispersal, such as animals, winds, and currents, behaved in non‐random ways. However, these early biogeographers found that dispersal was hard to observe, and, later, with the advent of the theory of Continental Drift, vicariance became regarded as a better scientific explanation for the arrangement of biodiversity, because it represented a falsifiable hypothesis. Thus, long distance dispersal was reduced to a nuisance parameter in biogeography; a random possibility that could never fully be ruled out in a scenario in which evidence supported vicariance. Today, there is strong interest to more fully integrate long distance dispersal into understanding the assembly and organization of biodiversity on earth. In this review, we discuss progress and prospects for explicitly testing long distance dispersal hypotheses including through uses of molecular, morphological, paleontological, and informatics methods. We focus on hypothesis testing of long distance dispersals involved in the assembly of the flora of North America, which is a robust preliminary study system on account of its extant and extinct biodiversity being well‐catalogued. 相似文献