529 research outputs found
Poly[[bis(2,2-bipyridine)bis[μ6-5-(carboxylatomethoxy)benzene-1,3-dicarboxylato]trimanganese(II)] monohydrate]
The title compound, {[Mn3(C10H5O7)2(C10H8N2)2]·H2O}n, was synthesized under hydrothermal conditions. Six carboxylate groups of six 5-(carboxylatomethoxy)benzene-1,3-dicarboxylate anions (OABDC3−) join three MnII ions into a trinuclear centrosymmetric [Mn3(μ2-COO)6] unit with one Mn site situated on a centre of inversion. The latter MnII ion exhibits a distorted MnO6 coordination, whereas the other MnII ion has a trigonal–bipyramidal MnN2O3 coordination environment resulting from three carboxylate O atoms and the two N atoms of the bipyridine ligand. Adjacent units are linked to each other by OABDC3− ligands into a layer parallel to (010). Within the layer, O—H⋯O hydrogen-bonding interactions involving the uncoordinated and half-occupied water molecule and the free carboxylate O atoms are observed. The layers stack along [010], constructing a three-dimensional structure through π–π interactions between adjacent pyridine rings, with a centroid–centroid distance of 3.473 (5) Å
Purin-6-One Derivatives as Phosphodiesterase-2 Inhibitors
A series of purin-6-one derivatives were synthesized, and their in vitro inhibitory activity against phosphodiesterase-2 (PDE2) was evaluated by using a fluorescence polarization assay. Three compounds, that are, 2j, 2p, and 2q, showed significant inhibitory activity against PDE2 with IC50 values of 1.73, 0.18, and 3.43 μM, respectively. Structure-activity relationship (SAR) analysis was performed to explore the relationship between the chemical structures of these compounds and their inhibitory activity. Compounds 2j, 2p, and 2q were further selected for molecular docking study. The docking results suggested that these ligands bind with hydrophobic pockets of the catalytic active site of PDE2, where a Tyr655 residue was found to be important in binding with compound 2p, the most potent inhibitor identified in this study. Our present study provides useful information for the future design of novel PDE2 inhibitors
Quantitative measurement of cell membrane receptor internalization by the nanoluciferase reporter: Using the G protein-coupled receptor RXFP3 as a model
AbstractNanoluciferase (NanoLuc) is a newly developed small luciferase reporter with the brightest bioluminescence to date. In the present work, we developed NanoLuc as a sensitive bioluminescent reporter to measure quantitatively the internalization of cell membrane receptors, based on the pH dependence of the reporter activity. The G protein-coupled receptor RXFP3, the cognate receptor of relaxin-3/INSL7, was used as a model receptor. We first generated stable HEK293T cells that inducibly coexpressed a C-terminally NanoLuc-tagged human RXFP3 and a C-terminally enhanced green fluorescent protein (EGFP)-tagged human RXFP3. The C-terminal EGFP-tag and NanoLuc-tag had no detrimental effects on the ligand-binding potency and intracellular trafficking of RXFP3. Based on the fluorescence of the tagged EGFP reporter, the ligand-induced RXFP3 internalization was visualized directly under a fluorescence microscope. Based on the bioluminescence of the tagged NanoLuc reporter, the ligand-induced RXFP3 internalization was measured quantitatively by a convenient bioluminescent assay. Coexpression of an EGFP-tagged inactive [E141R]RXFP3 had no detrimental effect on the ligand-binding potency and ligand-induced internalization of the NanoLuc-tagged wild-type RXFP3, suggesting that the mutant RXFP3 and wild-type RXFP3 worked independently. The present bioluminescent internalization assay could be extended to other G protein-coupled receptors and other cell membrane receptors to study ligand–receptor and receptor–receptor interactions
Related factors of vision recovery after complex traumatic and non-traumatic retinal detachment
AIM: To investigate the visual recovery factors in patients with complex traumatic and non-traumatic retinal detachment. METHODS: According to the history of ocular trauma before admission, 135 patients with complex retinal detachment were divided into traumatic group(n=66, 66 eyes)and non-traumatic group(n=69, 69 eyes). The results of visual recovery and complications were compared between the two groups. Logistic regression was used to analyze the related factors of visual recovery in the two groups. RESULTS: There was no significant difference in the recovery rate between the two groups within 24h after surgery(77.3% vs 78.3%, P>0.05), and there was no significant difference in the total incidence of complications at 3mo after surgery(18.2% vs 17.4%, P>0.05). Multifactorial Logistic regression analysis showed significant correlation between age, injury type, time since retinal detachment, rage of retinal detachment, preoperative vitreous blood, proliferative vitreoretinopathy(PVR)and postoperative visual recovery in patients with complex traumatic retinal detachment(PPCONCLUSION: Age, time since retinal detachment and rage of retinal detachment were significantly associated with traumatic and non-traumatic retinal detachment. The injury type, preoperative vitreous hemorrhage, PVR were significantly correlated with the visual recovery of traumatic retinal detachment patients. The condition of macular was significantly associated with the visual recovery of non-traumatic retinal detachment patients
A sacrificial coating strategy toward enhancement of metal-support interaction for ultrastable Au nanocatalysts
Supported gold (Au) nanocatalysts hold great promise for heterogeneous catalysis; however, their practical application is greatly hampered by poor thermodynamic stability. Herein, a general synthetic strategy is reported where discrete metal nanoparticles are made resistant to sintering, preserving their catalytic activities in high-temperature oxidation processes. Taking advantage of the unique coating chemistry of dopamine, sacrificial carbon layers are constructed on the material surface, stabilizing the supported catalyst. Upon annealing at high temperature under an inert atmosphere, the interactions between support and metal nanoparticle are dramatically enhanced, while the sacrificial carbon layers can be subsequently removed through oxidative calcination in air. Owing to the improved metal–support contact and strengthened electronic interactions, the resulting Au nanocatalysts are resistant to sintering and exhibit excellent durability for catalytic combustion of propylene at elevated temperatures. Moreover, the facile synthetic strategy can be extended to the stabilization of other supported catalysts on a broad range of supports, providing a general approach to enhancing the thermal stability and sintering resistance of supported nanocatalysts
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