Genetics

Genes linked to Alzheimer's risk, resilience identified

An international team of researchers led by scientists at Washington University School of Medicine in St. Louis has identified a pair of genes that influence risk for both late-onset and early-onset Alzheimer's disease.

Diseases, Conditions, Syndromes

New evidence points to viral culprit in AFM child paralysis

Scientists at the Center for Infection and Immunity (CII) at Columbia University Mailman School of Public Health, the U.S. Centers for Disease Control and Prevention (CDC), and the University of California San Diego report ...

Autism spectrum disorders

High levels of estrogen in the womb linked to autism

Scientist have identified a link between exposure to high levels of oestrogen sex hormones in the womb and the likelihood of developing autism. The findings are published today in the journal Molecular Psychiatry.

HIV & AIDS

HIV-infected cells persist in CSF in individuals on long-term ART

(HealthDay)—About half of HIV-positive individuals on long-term antiretroviral therapy (ART) have HIV-infected cells in their cerebrospinal fluid (CSF), according to a study published online July 15 in the Journal of Clinical ...

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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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