Second

It is typically measured in megahertz or gigahertz. One megahertz is equal to one million cycles per second, while one gigahertz equals one billion cy...

Your second pregnancy is often different than your first. You might show sooner, feel more tired, have stronger or more frequent back pains, and you m...

First messengers are extracellular molecules, often hormones or neurotransmitters. In contrast, second messengers are intracellular molecules that tra...