2 resultados para Catalysis by modified pillared clays
em WestminsterResearch - UK
Resumo:
The effect of lycopene on macrophage foam cell formation induced by modified low-density lipoprotein (LDL) was studied. Human monocyte-derived macrophages (HMDM) were incubated with lycopene in the presence or absence of native LDL (nLDL) or LDL modified by oxidation (oxLDL), aggregation (aggLDL), or acetylation (acLDL). The cholesterol content, lipid synthesis, scavenger receptor activity, and the secretion of inflammatory [interleukin (IL)-1β and tumor necrosis factor (TNF)-α] and anti-inflammatory (IL-10) cytokines was determined. Lycopene was found to decrease the synthesis of cholesterol ester in incubations without LDL or with oxLDL while triacylglycerol synthesis was reduced in the presence of oxLDL and aggLDL. Scavenger receptor activity as assessed by the uptake of acLDL was decreased by ∼30% by lycopene. In addition, lycopene inhibited IL-10 secretion by up to 74% regardless of the presence of nLDL or aggLDL but did not affect IL-1β or TNF-α release. Lycopene also reduced the relative abundance of mRNA transcripts for scavenger receptor A (SR-A) in THP-1 macrophages treated with aggLDL. These findings suggest that lycopene may reduce macrophage foam cell formation induced by modified LDL by decreasing lipid synthesis and downregulating the activity and expression of SR-A. However, these effects are accompanied by impaired secretion of the anti-inflammatory cytokine IL-10, suggesting that lycopene may also exert a concomitant proinflammatory effect.
Resumo:
This research looks at how the shift in the status of Egyptian bloggers from underground dissident voices to mainstream political and media players affected the plurality they add to the public space for discourse in Egypt’s authoritarian settings. The role of the internet – and more recently social media and bloggers – in democratic transition has been studied by various media scholars since the introduction of the worldwide web and especially after the Egyptian and Tunisian uprisings of 2011. But no work has been done to study how bringing those once-underground bloggers into the public and media spotlight affected the nature of the blogosphere and the bloggers themselves. Star bloggers were not only covered by the media after January 25th, 2011, they also started joining the media as column writers; a move that had various effects on them and the blogosphere but was never examined in media studies. The plurality the blogosphere adds to the Egyptian public space for discourse in light of those changes as well as in light of the financial and practical sustainability of blogging was hence never looked at in a context similar to Egypt’s. Guided by modified theories of the public sphere and theories of hegemony and manufacturing consent, I look at whether bloggers have been co-opted into the historical bloc in the process of renewing the social order and how this affects them and the online sphere. Also, guided by theories of power and media elites, I look at bloggers’ backgrounds to assess whether they come from power elites and are transforming into media elites, thus limiting the plurality of the online sphere. Finally, guided by theoretical works on institutionalizing and commercializing the internet, I look at how those shifts into mainstream affect the independence and freedom of the blogs and microblogs. The research uses a comparative study to assess how those changes affect prominent versus less prominent bloggers and compare their backgrounds. The study uses quantitative content analysis and framing analysis of chosen media outlets and interviews with bloggers, marketeers and media professionals. The findings trace an increase in media coverage of bloggers post January 25th, 2011, especially in the prominent bloggers category, and an overall positive framing of bloggers post the uprising. This led to the mainstreaming of bloggers into the media as well as public work, which had various implications on the freedom they had over their content and voice, both online and offline. It also points to a dramatic decrease in bloggers’ activity on their blogs in favour of mainstream and social media and due to star bloggers becoming more career-oriented and their failure to make blogs financially sustainable. The findings also indicate that more prominent bloggers seem to come from more elite backgrounds than others and enjoy luxuries that allow them the time, technology and security to post online. This research concludes that the shifts in bloggers’ status post-January 25th have limited the plurality they add to the discourse in Egypt.