In organic chemistry, the concept of conformational isomers is very important.

A tesseract is a four-dimensional geometric shape.

A 5-cell is a simple convex polytope in four dimensions.

General relativity is a theory of physics proposed by Einstein.

Special relativity is one of the fundamental theories of physics.

He feels dizzy when he stands up suddenly due to orthostatic hypotension.

My father was diagnosed with ankylosing spondylitis.

In organic chemistry, pyruvic acid plays an important role.

His father fell into a persistent vegetative state due to a traffic accident.

Basic oxides react with acids to produce salt and water.