Protective desilication of β zeolite: A mechanism study and its application in ethanol-acetaldehyde to 1,3-butadiene

Author(s):  
Minhua Zhang ◽  
Yunan Qin ◽  
Haoxi Jiang ◽  
Lingtao Wang
Keyword(s):  
2019 ◽  
Author(s):  
Huaimin Wang ◽  
Zhaoqianqi Feng ◽  
Weiyi Tan ◽  
Bing Xu

<p>Selectively targeting cell nucleolus remains a challenge. Here we report the first case that D-peptides form membraneless molecular condensates with RNA for targeting cell nucleolus. A D-peptide derivative, enriched with lysine and hydrophobic residues, self-assembles to form nanoparticles, which enter cells through clathrin dependent endocytosis and mainly accumulate at cell nucleolus. Structural analogue of the D-peptide reveals that particle morphology of the assemblies, which depends on the side chain modification, favors the cellular uptake. Contrasting to those of the D-peptide, the assemblies of the corresponding L-enantiomer largely localize in cell lysosomes. Preliminary mechanism study suggests that the D-peptide nanoparticles interact with RNA to form membraneless condensates in the nucleolus, which further induces DNA damage and results in cell death. This work illustrates a new strategy for rationally designing supramolecular assemblies of D-peptides for targeting subcellular organelles.</p>


2019 ◽  
Author(s):  
Przemyslaw Rzepka ◽  
Zoltán Bacsik ◽  
Andrew J. Pell ◽  
Niklas Hedin ◽  
Aleksander Jaworski

Formation of CO<sub>3</sub><sup>2-</sup> and HCO<sub>3</sub><sup>-</sup> species without participation of the framework oxygen atoms upon chemisorption of CO<sub>2</sub> in zeolite |Na<sub>12</sub>|-A is revealed. The transfer of O and H atoms is very likely to have proceeded via the involvement of residual H<sub>2</sub>O or acid groups. A combined study by solid-state <sup>13</sup>C MAS NMR, quantum chemical calculations, and <i>in situ</i> IR spectroscopy showed that the chemisorption mainly occurred by the formation of HCO<sub>3</sub><sup>-</sup>. However, at a low surface coverage of physisorbed and acidic CO<sub>2</sub>, a significant fraction of the HCO<sub>3</sub><sup>-</sup> was deprotonated and transformed into CO<sub>3</sub><sup>2-</sup>. We expect that similar chemisorption of CO<sub>2</sub> would occur for low-silica zeolites and other basic silicates of interest for the capture of CO<sub>2</sub> from gas mixtures.


2013 ◽  
Vol 33 (11) ◽  
pp. 1862-1869 ◽  
Author(s):  
Chunyan WANG ◽  
Jiti ZHOU ◽  
Junkang HE ◽  
Chuansong HAO ◽  
Yuzhen PAN ◽  
...  
Keyword(s):  

2019 ◽  
Vol 18 (7) ◽  
pp. 566-577 ◽  
Author(s):  
Xinxin Fu ◽  
Tingting Qin ◽  
Jiayu Yu ◽  
Jie Jiao ◽  
Zhanqiang Ma ◽  
...  

Background: Alzheimer’s disease is one of the most common neurodegenerative diseases in many modern societies. The core pathogenesis of Alzheimer’s disease includes the aggregation of hyperphosphorylated Tau and abnormal Amyloid-β generation. In addition, previous studies have shown that neuroinflammation is one of the pathogenesis of Alzheimer’s disease. Formononetin, an isoflavone compound extracted from Trifolium pratense L., has been found to have various properties including anti-obesity, anti-inflammation, and neuroprotective effects. But there are very few studies on the treatment of Alzheimer’s disease with Formononetin. Objective: The present study focused on the protective activities of Formononetin on a high-fat dietinduced cognitive decline and explored the underlying mechanisms. Methods: Mice were fed with HFD for 10 weeks and intragastric administrated daily with metformin (300 mg/kg) and Formononetin (20 and 40 mg/kg). Results: We found that Formononetin (20, 40 mg/kg) significantly attenuated the learning and memory deficits companied by weight improvement and decreased the levels of blood glucose, total cholesterol and triglyceride in high-fat diet-induced mice. Meanwhile, we observed high-fat diet significantly caused the Tau hyperphosphorylation in the hippocampus of mice, whereas Formononetin reversed this effect. Additionally, Formononetin markedly reduced the levels of inflammation cytokines IL-1β and TNF-α in high-fat diet-induced mice. The mechanism study showed that Formononetin suppressed the pro-inflammatory NF-κB signaling and enhanced the anti-inflammatory Nrf-2/HO-1 signaling, which might be related to the regulation of PGC-1α in the hippocampus of high-fat diet -induced mice. Conclusion: Taken together, our results showed that Formononetin could improve the cognitive function by inhibiting neuroinflammation, which is attributed to the regulation of PGC-1α pathway in HFD-induced mice.


2018 ◽  
Vol 93 (5) ◽  
pp. 603-610 ◽  
Author(s):  
Samia Mathlouthi ◽  
Abderrazek Oueslati ◽  
Bassem Louati

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