The phrase "almost completely restricted to" is correct and usable in written English.
It can be used to describe something that is primarily limited to a specific category or group, with only a few exceptions.
Example: "The species is almost completely restricted to the tropical rainforest ecosystem."
Alternatives: "largely confined to" or "primarily limited to".
p63 was almost completely restricted to myoepithelial cell nuclei, and did not stain vascular smooth muscle or myofibroblasts.
Abstract: General knowledge of multilingualism in NYC is almost completely restricted to major national languages like Spanish, Russian, Mandarin Chinese, among several others.
As the winter season took hold, the party was almost completely restricted to the cramped living quarters.
In GLW the signature is almost completely restricted to the position of MAP2K6 whereas it is more extended in FGV.
In the case of differentiated, resting GL15 cells (confluent cultures), dye-transfer was almost completely restricted to the cells initially loaded with the dye (Table 2).
PAX7 expression is implicated in the specification and maintenance of satellite cells, and here we have shown that PAX7 expression is almost completely restricted to RMS tumours with no known translocation.
By contrast, in Namalwa cells, as well as in PBL, either DR4 or DR5 appeared almost completely restricted at detergent-soluble fractions 10 and 11.
With the exception of TRDVY, all of the subgroups detected in the sequenced TRD repertoire belong to phylogenetic Group 4 and consequently the TRD repertoire analysed here is almost completely restricted (>99%) to this Group.
There was dissatisfaction with the restrictive drinking laws; environmentalists campaigned for more natural parks and more 'green' practices; police powers stood strong, 'no loitering' legislation remained in place; gambling was almost completely restricted.
In situations where sporulation is almost completely restricted [e.g. pathogen isolate host combinations resulting in low ITs (0 2)], there may be strong selection for novel infectivity rather than increased aggressiveness.
