Additive-Free Construction of Tetrahydropyrimidine Skeleton by using 1,3,5-Triazinane as Four-Atom Synthon.

Herein, an unprecedented [4 + 2] cycloaddition of enaminone with 1,3,5-triazinane has been developed. The representative semihydrogenated aromatic heterocycle 1,2,3,4-tetrahydropyrimidines have been synthesized with a broad substrate scope, demonstrating potential antitumor activity. This approach has been smoothly conducted under additive-free and environmentally friendly conditions that are compatible with various functional groups.

Mn(OAc)-promoted [3+2] cyclization of enaminone with isocyanoacetate: Rapid access to pyrrole-2-carboxylic ester derivatives with potent anticancer activity.

The practical and facile Mn(OAc)-promoted [3+2] cycloaddition reaction of enaminones with isocyanoacetate was developed, that delivered a diversity of 3-aroyl pyrrole-2-carboxylic esters with broad substrates scope. The most of the newly synthesized compounds exhibit moderate antiproliferative activity against four cancer cells. Notably, compound 2n demonstrate the most potent activity with average IC values of 5.

5T magnetic resonance imaging: radio frequency hardware and initial brain imaging.

Background: We aimed to demonstrate the feasibility of generating high-resolution human brain magnetic resonance imaging (MRI) at 5 Tesla (T) using a quadrature birdcage transmit/48-channel receiver coil assembly.

Methods: A quadrature birdcage transmit/48-channel receiver coil assembly was designed for human brain imaging at 5T. The radio frequency (RF) coil assembly was validated by electromagnetic (EM) simulations and phantom imaging experimental studies.

Time-of-Flight Intracranial MRA at 3 T versus 5 T versus 7 T: Visualization of Distal Small Cerebral Arteries.

Background Three-dimensional (3D) time-of-flight (TOF) MR angiography (MRA) at 7 T has been reported to have high image quality for visualizing small perforating vessels. However, B inhomogeneity and more physiologic considerations limit its applications. Angiography at 5 T may provide another choice for intracranial vascular imaging.

Glioma grading, molecular feature classification, and microstructural characterization using MR diffusional variance decomposition (DIVIDE) imaging.

Objective: To evaluate the potential of diffusional variance decomposition (DIVIDE) for grading, molecular feature classification, and microstructural characterization of gliomas.

Materials And Methods: Participants with suspected gliomas underwent DIVIDE imaging, yielding parameter maps of fractional anisotropy (FA), mean diffusivity (MD), anisotropic mean kurtosis (MK), isotropic mean kurtosis (MK), total mean kurtosis (MK), MK/MK, and microscopic fractional anisotropy (μFA). Tumor type and grade, isocitrate dehydrogenase (IDH) 1/2 mutant status, and the Ki-67 labeling index (Ki-67 LI) were determined after surgery.