19 research outputs found

    Reed characteristics and soil properties in natural and degraded reed wetlands.

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    <p>Reed characteristics and soil properties in natural and degraded reed wetlands.</p

    Lyophilic but Nonwettable Organosilane-Polymerized Carbon Dots Inverse Opals with Closed-Cell Structure

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    This paper presents a unique lyophilic but nonwettable property of organosilane-polymerized carbon dots inverse opals photonic crystals (SiCDPCs) with closed-cell structure. Little stopband shift was observed for the SiCDPCs when being immersed into the solvents such as isopropanol, olive oil, DMSO, hexane, silicone oil, ethanediol, etc. but keeping lyophilic property. This could be attributed to the combined effect of closed-cell structure and the unique chemical composition of SiCDPCs. Furthermore, more than 30 kinds of organic solvents had been investigated, it was found that there were two kinds of factors that affected the stopband shift upon solvent’s immersing; one was the polarity of solvent, and the other one was the viscosity of solvent. That is, mainly nonpolar or high viscosity solvents showed lyophilic but nonwettable property. The distinct solvent-responsive behaviors of the SiCDPCs toward polar/nonpolar solvents had been utilized for the fabrication of 2D/3D pattern. Additionally, the as-prepared SiCDPCs showed improved optical limiting property, excellent low-temperature resistance, and abrasion tolerant property. It is of great importance for the development of multifunctional novel coating materials and creation of novel optical devices

    General condition of the sampling sites.

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    <p>S1-Low tidal flat; S2-Intertidal flat; S3-High tidal flat A; S4-High tidal flat B.</p><p>General condition of the sampling sites.</p

    Shape-Controlled Metal-Free Catalysts: Facet-Sensitive Catalytic Activity Induced by the Arrangement Pattern of Noncovalent Supramolecular Chains

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    Metal-free catalytic materials have recently received broad attention as promising alternatives to metal-involved catalysts. This is owing to their inherent capability to overcome the inevitable limitations of metal-involved catalysts, such as high sensitivity to poisoning, the limited reserves, high cost and scarcity of metals (especially noble metals), <i>etc.</i> However, the lack of shape-controlled metal-free catalysts with well-defined facets is a formidable bottleneck limiting our understandings on the underlying structure–activity relationship at atomic/molecular level, which thereby restrains their rational design. Here, we report that catalytically active crystals of a porphyrin, 5,10,15,20-tetrakis­(pentafluorophenyl)­porphyrin, could be shaped into well-defined cubes and sheet-like tetradecahedrons (TDHD), which are exclusively and predominantly enclosed by {101} and {001} facets, respectively. Fascinatingly, compared to the cubes, the TDHDs display substantially enhanced catalytic activity toward water decontamination under visible-light irradiation, although both the architectures have identical crystalline structure. We disclose that such interesting shape-sensitive catalytic activity is ascribed to the distinct spatial separation efficiency of photogenerated electrons and holes induced by single-channel and multichannel charge transport pathways along noncovalent supramolecular chains, which are arranged as parallel-aligned and 2D network patterns, respectively. Our findings provide an ideal scientific platform to guide the rational design of next-generation metal-free catalysts of desired catalytic performances

    11β-Hydroxysteroid Dehydrogenase Type 1 Gene Knockout Attenuates Atherosclerosis and In Vivo Foam Cell Formation in Hyperlipidemic apoE<sup>−/−</sup> Mice

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    <div><h3>Background</h3><p>Chronic glucocorticoid excess has been linked to increased atherosclerosis and general cardiovascular risk in humans. The enzyme 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1) increases active glucocorticoid levels within tissues by catalyzing the conversion of cortisone to cortisol. Pharmacological inhibition of 11βHSD1 has been shown to reduce atherosclerosis in murine models. However, the cellular and molecular details for this effect have not been elucidated.</p> <h3>Methodology/Principal Findings</h3><p>To examine the role of 11βHSD1 in atherogenesis, 11βHSD1 knockout mice were created on the pro-atherogenic apoE<sup>−/−</sup> background. Following 14 weeks of Western diet, aortic cholesterol levels were reduced 50% in 11βHSD1<sup>−/−</sup>/apoE<sup>−/−</sup> mice vs. 11βHSD1<sup>+/+</sup>/apoE<sup>−/−</sup> mice without changes in plasma cholesterol. Aortic 7-ketocholesterol content was reduced 40% in 11βHSD1<sup>−/−</sup>/apoE<sup>−/−</sup> mice vs. control. In the aortic root, plaque size, necrotic core area and macrophage content were reduced ∼30% in 11βHSD1<sup>−/−</sup>/apoE<sup>−/−</sup> mice. Bone marrow transplantation from 11βHSD1<sup>−/−</sup>/apoE<sup>−/−</sup> mice into apoE<sup>−/−</sup> recipients reduced plaque area 39–46% in the thoracic aorta. In vivo foam cell formation was evaluated in thioglycollate-elicited peritoneal macrophages from 11βHSD1<sup>+/+</sup>/apoE<sup>−/−</sup> and 11βHSD1<sup>−/−</sup>/apoE<sup>−/−</sup> mice fed a Western diet for ∼5 weeks. Foam cell cholesterol levels were reduced 48% in 11βHSD1<sup>−/−</sup>/apoE<sup>−/−</sup> mice vs. control. Microarray profiling of peritoneal macrophages revealed differential expression of genes involved in inflammation, stress response and energy metabolism. Several toll-like receptors (TLRs) were downregulated in 11βHSD1<sup>−/−</sup>/apoE<sup>−/−</sup> mice including TLR 1, 3 and 4. Cytokine release from 11βHSD1<sup>−/−</sup>/apoE<sup>−/−</sup>-derived peritoneal foam cells was attenuated following challenge with oxidized LDL.</p> <h3>Conclusions</h3><p>These findings suggest that 11βHSD1 inhibition may have the potential to limit plaque development at the vessel wall and regulate foam cell formation independent of changes in plasma lipids. The diminished cytokine response to oxidized LDL stimulation is consistent with the reduction in TLR expression and suggests involvement of 11βHSD1 in modulating binding of pro-atherogenic TLR ligands.</p> </div
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