The phrase "is retained within" is correct and usable in written English.
You can use this phrase to describe something that is confined or remains within a certain area or space. For example: The knowledge is retained within the walls of the library.
In any event, questions arise as to how and how well the dye is retained within the fibre.
We try to make sure that when we offer funding or other support for new developments, the benefit of that support is retained within our borough.
If the ingested material is resistant to digestion, it is retained within the phagocyte and is thus effectively removed from further interaction with the host.
The amount of water that is retained within green roofs depends not only on their depth, but also on the climate, which drives the stochastic soil moisture dynamic.
The solid-state 13C NMR studies clearly show that pentane is chemisorbed during the polymerization and is retained within the foam matrix.
Naked plasmid and lipoplexes can be efficiently entrapped within the hydrogel, and after 1 day in solution more than 70% of the entrapped DNA is retained within the gel, with a sustained release observed for at least 19 days.
The results allowed us to discard the notion that p14 is entering the nucleus, or is retained within, as the sole consequence of being part of a larger complex.
The goal of our study was to determine if the cavity-using assemblage associated with old upland forest in this region is retained within aggregated harvests with structural retention.
Intratendinous injectant is retained within the tendon.
The entrapped NO is retained within the pores of the NPs until exposed to moisture [18, 23].
Immunostaining of mutant embryos shows that the embryo-lethal alleles produce either no wg antigen or a form of the protein that is retained within cells.
