A General Strategy to Control Viscosity Sensitivity of Molecular Rotor-Based Fluorophores.

Molecular rotor-based fluorophores (RBFs) have been widely used in many fields. However, the lack of control of their viscosity sensitivity limits their application. Herein, this problem is resolved by chemically installing extended π-rich alternating carbon-carbon linkages between the rotational electron donors and acceptors of RBFs.

AggFluor: Fluorogenic Toolbox Enables Direct Visualization of the Multi-Step Protein Aggregation Process in Live Cells.

Aberrantly processed or mutant proteins misfold and assemble into a variety of soluble oligomers and insoluble aggregates, a process that is associated with an increasing number of diseases that are not curable or manageable. Herein, we present a chemical toolbox, AggFluor, that allows for live cell imaging and differentiation of complex aggregated conformations in live cells. Based on the chromophore core of green fluorescent proteins, AggFluor is comprised of a series of molecular rotor fluorophores that span a wide range of viscosity sensitivity.

A General Strategy to Enhance Donor-Acceptor Molecules Using Solvent-Excluding Substituents.

While organic donor-acceptor (D-A) molecules are widely employed in multiple areas, the application of more D-A molecules could be limited because of an inherent polarity sensitivity that inhibits photochemical processes. Presented here is a facile chemical modification to attenuate solvent-dependent mechanisms of excited-state quenching through addition of a β-carbonyl-based polar substituent. The results reveal a mechanism wherein the β-carbonyl substituent creates a structural buffer between the donor and the surrounding solvent.

Precision, Reliability, and Responsiveness of a Novel Automated Quantification Tool for Cartilage Thickness: Data from the Osteoarthritis Initiative.

Objective: Accurate automated segmentation of cartilage should provide rapid reliable outcomes for both epidemiological studies and clinical trials. We aimed to assess the precision and responsiveness of cartilage thickness measured with careful manual segmentation or a novel automated technique.

Methods: Agreement of automated segmentation was assessed against 2 manual segmentation datasets: 379 magnetic resonance images manually segmented in-house (training set), and 582 from the Osteoarthritis Initiative with data available at 0, 1, and 2 years (biomarkers set).

Marked and rapid change of bone shape in acutely ACL injured knees - an exploratory analysis of the Kanon trial.

Background: To investigate changes in knee 3D bone shape over the first 5 years after acute anterior cruciate ligament (ACL) injury in participants of the randomized controlled KANON-trial.

Methods: Serial MR images over 5 years from 121 young (32 women, mean age 26.1 years) adults with an acute ACL tear in a previously un-injured knee were analyzed using statistical shape models for bone.