Bottlebrush Polymers for Articular Joint Lubrication: Influence of Anchoring Group Chemistry on Lubrication Properties.

The role of carboxylic, aldehyde, or epoxide groups incorporated into bottlebrush macromolecules as anchoring blocks (or cartilage-binding blocks) is investigated by measuring their lubricating properties and cartilage-binding effectiveness. Mica modified with amine groups is used to mimic the cartilage surface, while bottlebrush polymers functionalized with carboxylic, aldehyde, or epoxide groups played the role of the lubricant interacting with the cartilage surface. We demonstrate that bottlebrushes with anchoring blocks effectively reduce the friction coefficient on modified surfaces by 75-95% compared to unmodified mica.

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Top-of-the-basilar artery occlusion frequently causes infarction of the midbrain, thalamus, and portions of the temporal and occipital lobes as the vascular supply of these regions comes from the posterior communicating and posterior cerebral arterial tributaries of the basilar artery. Clinical signs include an array of visual, oculomotor, and behavioral abnormalities, usually without prominent motor dysfunction, which makes diagnosis challenging for those inexperienced with these sign. We describe a 59-year-old male presenting with acute ischemic stroke due to top-of-the-basilar artery occlusion.

Simulated Microgravity Induces the Proliferative Inhibition and Morphological Changes in Porcine Granulosa Cells.

Astronauts are always faced with serious health problems during prolonged spaceflights. Previous studies have shown that weightlessness significantly affects the physiological function of female astronauts, including a change in reproductive hormones and ovarian cells, such as granulosa and theca cells. However, the effects of microgravity on these cells have not been well characterized, especially in granulosa cells.