ACS query object that "contains", instead of "starts by"

Hi.

I know we can query objects in ACS with a regex expresion to search for a value that starts with some value, like this:

Cloud.Objects.query({
  classname: 'Topics',
  where: {name: {'$regex': '^' + stringToSearch}}
}...

But, can we search for values in the middle of the string? For example, if my objects are:

apple
appleseed
seed

I can search for app and regex will retrieve the first 2 elements. It is possible to do a search for see to retrieve the last 2 elements?