Alzheimer's disease & dementia

Brain changes linked with Alzheimer's years before symptoms appear

In a records review of 290 people at risk for Alzheimer's disease, scientists at Johns Hopkins say they have identified an average level of biological and anatomical brain changes linked to Alzheimer's disease that occur ...

Health

STDs: A serious health threat at every age

(HealthDay)—If you're back on the dating scene after being in a monogamous relationship, know that STDs, or sexually transmitted diseases, aren't just a concern for teens and people in their 20s. STD rates are rising in ...

Parkinson's & Movement disorders

Novel device opens new doors for Parkinson's disease diagnostics

Currently, there are no disease-modifying therapies for the treatment of Parkinson's disease; however, one potential strategy for treatment is to prevent α-synuclein aggregation. As a first step, researchers at Osaka University ...

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Fluid

In physics, a fluid is a substance that continually deforms (flows) under an applied shear stress, no matter how small. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids.

In common usage, "fluid" is often used as a synonym for "liquid", with no implication that gas could also be present. For example, "brake fluid" is hydraulic oil and will not perform its required function if there is gas in it. This colloquial usage of the term is also common in medicine and in nutrition ("take plenty of fluids").

Liquids form a free surface (that is, a surface not created by the container) while gases do not. The distinction between solids and fluid is not entirely obvious. The distinction is made by evaluating the viscosity of the substance. Silly Putty can be considered to behave like a solid or a fluid, depending on the time period over which it is observed. It is best described as a viscoelastic fluid. There are many examples of substances proving difficult to classify. A particularly interesting one is pitch, as demonstrated in the pitch drop experiment currently running at the University of Queensland.

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