find a string contained in an attribute

Hi,

I want to know if it is possible to search for a string of characters inside
an attribute for example I have the following table and values

cod_unidad | nombre_uni
------------+---------------------------------------------
1 | Facultad de Ciencias Naturales y Matemática
2 | Facultad de Ciencias Humanidades
3 | Facultad de Ingeniería
4 | Facultad de Agronomía
5 | Oficinas Centrales
6 | test

I want to retrieve all the rows where I find the word Ciencias for example.
Is there a function or with select is possible to do it?

thanks in advance,

karina
El Salvador, Centroamerica