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In this study, three types of chiral fluorescent zirconium-based metal-organic framework materials were synthesized using l-dibenzoyl tartaric acid as the chiral modifier by the solvent-assisted ligand incorporation method, which was the porous coordination network yellow material, denoted as PCN-128Y. PCN-128Y-1 and PCN-128Y-2 featured unique chiral selectivity for the Gln enantiomers amongst seven acids and the highly stable luminescence property, which were caused by the heterochiral interaction and aggregation-induced emission. Furthermore, a rapid fluorescence method for the chiral detection of glutamine (Gln) enantiomers was developed. The homochiral crystals of PCN-128Y-1 displayed enantiodiscrimination in the quenching by d-Gln such that the ratio of enantioselectivity was 2.0 in 30 seconds at pH 7.0, according to the Stern-Volmer quenching plots. The detection limits of d- and l-Gln were 6.6 × 10-4 mol L-1 and 3.3 × 10-4 mol L-1, respectively. Finally, both the maximum adsorption capacities of PCN-128Y-1 for the Gln enantiomers (Q e(l-Gln) = 967 mg g-1; Q e(d-Gln) = 1607 mg g-1) and the enantiomeric excess value (6.2%) manifested that PCN-128Y-1 had strong adsorption capacity for the Gln enantiomers and higher affinity for d-Gln.
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Parkinson’s disease (PD) is the second most common neurodegenerative disease, which manifests with both motor and non-motor symptoms. Circadian rhythm dysregulation, as one of the most challenging non-motor features of PD, usually appears long before obvious motor symptoms. Moreover, the dysregulated circadian rhythm has recently been reported to play pivotal roles in PD pathogenesis, and it has emerged as a hot topic in PD research. In this review, we briefly introduce the circadian rhythm and circadian rhythm-related genes, and then summarize recent research progress on the altered circadian rhythm in PD, ranging from clinical features to the possible causes of PD-related circadian disorders. We believe that future comprehensive studies on the topic may not only help us to explore the mechanisms of PD, but also shed light on the better management of PD.
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Objective To evaluate the role of hippocampal histone acetylation in isoflurane-induced amnestic effect in mice.Methods Fifty-four male C57BL/6J mice,aged 8 weeks,weighing 18-22 g,were randomly divided into 3 groups (n =18 each) using a random number table:control group (group C),isoflurane group (group ISO) and histone deacetylase inhibitor sodium butyrate group (group SB).Group C inhaled 35％ oxygen for 30 ain,and ISO and SB groups inhaled the mixture of 35 ％ oxygen and 0.4％ isoflurane for 30 min,and then the animals underwent contextual fear conditioning training.After the end of training,normal saline 6 ml/kg was intraperitoneally injected in C and ISO groups,while in group SB,sodium butyrate 1.2 g/kg was intraperitoneally injected.One hour after the end of training,3 mice were sacrificed randomly in each group and their hippocampi were immediately removed for determination of the expression of acetylated histone-H3 (Ac-H3) and Ac-H4 by Western blot.Twenty-four hours after the end of training,contextual fear conditioning test and open field test were conducted.The freezing time,total distance and time of staying at the central zone were recorded.Results Compared with group C,Ac-H3 and Ac-H4 expression was significantly down-regulated,and the percentage of freezing time during testing was decreased in group ISO (P ＜ 0.05).Compared with group ISO,Ac-H3 and Ac-H4 expression was significantly up-regulated,and the percentage of freezing time during testing was increased in group SB (P ＜ 0.05).There was no significant difference in the percentage of freezing time during training,total distance and time of staying in the central zone among the 3 groups (P ＞ 0.05).Conclusion Hippocampal histone acetylation is involved in the regulation of isoflurane-induced amnestic effect in mice.
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Bacterivory by heterotrophic nanoflagellates and ciliates has been widely studied in aquatic environments, but data on the grazing of amoebae, are still scarce. From the water samples of Dianchi Lake (Kunming, Yunnan Province, China), we isolated an amoeba, designated as Naegleria sp. strain W2, which had potent grazing effects on some kind of cyanobacteria. The food selection mechanism and the digestion process of the amoeba were investigated in batch experiments. Predation experiments showed that filamentous cyanobacteria (e.g., Anabaena, Cylindrospermum, Gloeotrichia, and Phormidium) were readily consumed, with clearance rates ranging from 0.332 to 0.513 nL amoeba(-1) h(-1). The tight threads (Oscilltoria) and aggregates (Aphanizomenon) could not be ingested; however, their sonicated fragments were observed inside food vacuoles, suggesting that their morphologies prevent them from being ingested. Live video microscopy noted that unicellular Chroococcaceae (e.g., Synechococcus, Aphanocapsa, and Microcystis) were excreted after ingestion, indicating that food selection takes place inside food vacuoles. To determine whether the tastes or the toxins prevented them from being digested, heat-killed cells were retested for predation. Digestion rates and ingestion rates of the amoebae for filamentous cyanobacteria were estimated from food vacuole content volume. Through a "cold-chase" method, we found that the food vacuole contents declined exponentially in diluted amoebae cells, and digestion rates were relatively constant, averaging about 1.5% food vacuole content min(-1) at 28 degrees Celsius. Ingestion strongly depended on the satiation status of the amoebae, starved amoebae fed at higher rates compared with satiated amoebae. Our results suggest that the food selection and food processing mechanisms of the amoeba are similar to those of interception feeding flagellates; however, filamentous cyanobacteria cannot obtain a refuge under the grazing pressure of phagotrophic amoebae, which may widen our knowledge on the grazing of protists.
