Please help! I'm totally confused whether to use or omit the definite article in front of plural or uncountable nouns. I'm writing a scientific article. Here is an excerpt (N.B. ROS = reactive oxygen species, plural).
(The?) studies investigating (the?) ROS production in (the?) primary T cells are limited, especially (the?) studies in (the?) primary human T cells. Moreover, (the?) majority of those studies employed (the?) highly artificial types of (the?) stimulation, such as (the?) stimulations with (the?) PMA and (the?) ionomycin or (the?) CD3 and (the?) CD28 antibodies added in (the?) solution, leading to (the?) T-cell hyperactivation or (the?) unresponsiveness, respectively. There were also no precautions taken to discriminate (the?) T cell-derived ROS from that emanating from (the?) phagocytic cells, which are always present in (the?) preparations of (the?) primary T cells and could be easily activated by (the?) same stimulatory agents.
All I know is that for plural countable or uncountable nouns the rule is:
If a noun (or noun phrase?) refers to all of the group/entity – no article is required (word typical can be inserted)
If a noun (or noun phrase?) refers to a subset of the group/entity – the should be used (those/that can be inserted instead)
The major problem for me is to understand whether it is a noun or a noun phrase that must refer to a subset of a group, and whether the rest of the noun phrase can make noun to refer to a subset. For example,
The studies investigating the ROS production in primary T cells are limited, especially the studies in primary human T cells.
Here, the studies refer to a subset of studies devoted to investigating the ROS production in primary T cells. The ROS production refers to a subset of ROS production that occurs in primary T cells. On the other hand, primary T cells in this context are generic, so no article is required. Is my logic correct?
Or can it be that studies investigating ROS production in primary T cells, studies in primary human T cells and ROS production in primary T cells are also generic concepts, and hence do not require articles?
Studies investigating ROS production in primary T cells are limited, especially studies in primary human T cells.