"On Water" Catalytic Aldol Reaction between Isatins and Acetophenones: Interfacial Hydrogen Bonding and Enamine Mechanism.

"On water" catalytic aldol reaction catalyzed by polyetheramine (D230) has been developed for easy access to 3-substituted 3-hydroxyindolin-2-ones through the reaction between various substituted isatins and acetophenones/cyclic ketones in high yields under room temperature. Systematic mechanism investigation uncovers the secret for the on water catalytic aldol reaction: comparison of the heterogeneous and homogeneous reaction circumstances with yields of 95 and 20%, respectively, indicates the on-water reaction dominating; interfacial hydrogen bonding between isatin with H2O is tested based on the downfield shift of the C2 and C3's 13C NMR signals when water was added to the CDCl3 solution of isatin; Lewis base polyetheramine D230 catalyzes the aldol reaction via the enamine mechanism verified by in situ NMR and ESI-MS analysis.

Amperometric hydrogen peroxide biosensor based on immobilization of hemoglobin on a glassy carbon electrode modified with fe(3)o(4)/chitosan core-shell microspheres.

Novel magnetic Fe(3)O(4)/chitosan (CS) microspheres were prepared using magnetic Fe(3)O(4) nanoparticles and the natural macromolecule chitosan. Then, using an easy and effective hemoglobin (Hb) immobilization method, an innovative biosensor with a Fe(3)O(4)/CS-Hb-Fe(3)O(4)/CS "sandwich" configuration was constructed. This biosensor had a fast (less than 10 s) response to H(2)O(2) and excellent linear relationships were obtained in the concentration range of 5.0 × 10(-5) to 1.8 × 10(-3) M and 1.8 × 10(-3) to 6.8 × 10(-3) M with a detection limit of 4.0 × 10(-6) M (s/n = 3) under the optimum conditions. The apparent Michaelis-Menten constant K(m) was 0.29 mM and it showed the excellent biological activity of the fixed Hb. Moreover, the biosensor had long-time stability and good reproducibility. The method was used to determine H(2)O(2) concentration in real samples.

A robust multifunctional ligand-controlled palladium-catalyzed carbonylation reaction in water.

A novel, hydrophilic and recyclable methoxypolyethylene glycol (PEG)-modulated s-triazine-based multifunctional Schiff base/N,P-ligand L9 was prepared and used in Pd-catalyzed Heck-type carbonylative coupling reactions, affording diverse chalcone derivatives and 1,4-dicarbonyl esters in good yields.

Cortical Surface Area Rather Than Cortical Thickness Potentially Differentiates Radiation Encephalopathy at Early Stage in Patients With Nasopharyngeal Carcinoma.

Radiation encephalopathy (RE) is one of the most severe complications in nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT). However, the morphological alteration of early RE is insufficiently investigated. We aimed to investigate the cortical thickness and surface area alterations in NPC patients with or without RE in the follow-up. A total of 168 NPC patients each underwent a single scan and analysis at various times either Pre-RT (n = 56) or Post-RT (n = 112). We further divided the Post-RT NPC patients into three groups based on the time of the analysis following RT (Post-RTwithin 6 months and Post-RT7-12 months) or whether RE signs were detected in the analysis (Post-RTRE proved in follow-up). We confined the vertex-wise analyses of the cortical thickness and surface area to the bilateral temporal lobes. Interestingly, we revealed a gradual increase in the cortical surface area of the temporal lobe with increasing time after RT within the Post-RTRE proved in follow-up group, consistent with the between-group findings, which showed a significant increase in cortical surface area in the Post-RTRE proved in follow-up group relative to the Pre-RT group and the Post-RTwithin 6 months group. By contrast, such a trend was not observed in the cortical thickness findings. We concluded that the cortical surface area, rather than cortical thickness, may serve as a potential biomarker for early diagnosis of RE.