4th century - Wikipedia, the free encyclopedia As a means of recording the passage of time, the 4th century (per the Julian calendar and Anno Domini/Common era) was that century which lasted from 301 to 400.
4th century BC - Wikipedia, the free encyclopedia The 4th century BC started the first day of 400 BC and ended the last day of 301 BC. It is considered part of the Classical era, epoch, or historical period.
4th millennium BC - Wikipedia, the free encyclopedia The 4th millennium BC saw major changes in human culture. It marked the beginning of the Bronze Age and of writing. The city states of Sumer and the kingdom of Egypt were ...
Progestin - Wikipedia, the free encyclopedia A progestin is a synthetic progestogen that has progestinic effects similar to progesterone The two most common uses of progestins are for hormonal contraception (either alone ...
Fourth dimension - Wikipedia, the free encyclopedia Science. Four-dimensional space, the concept of a fourth spatial dimension; Spacetime, the unification of time and space as a four-dimensional continuum
Quinolone - Wikipedia, the free encyclopedia The quinolones are a family of synthetic broad-spectrum antibiotics. The term quinolone(s) refers to potent synthetic chemotherapeutic antibacterials.
Cephalosporin - Wikipedia, the free encyclopedia The cephalosporins (sg. / ˌ s ɛ f ə l ɵ ˈ s p ɔr ɨ n /) are a class of β-lactam antibiotics originally derived from the fungus Acremonium, which was previously known as ...