Due to the peculiarity of the discrete system, it is difficult to study its stability and capture, and there are few related studies.
Because Pnpla6 is essential for embryonic development and Pnpla6 knockout mice died around embryonic day 9 (Moser et al., 2004; Winrow et al., 2003), it is difficult to study its function in early development using mice.
"It is difficult to study from others.
The great whales provide great problems: it is difficult to study them in the field.
It is difficult to study at night because we don't have power and I can't go through my notes in darkness.
It is difficult to study human mental illnesses using animals as analogs, because most mental disorders either do not occur or are not recognizable in animals.
However, it is difficult to study subjects who have both diseases simultaneously.
For the heterogeneity of shale, it is difficult to study the organic pores and inorganic pores respectively.
For example, by using the last expression, it is difficult to study composition operators on α-Bloch space.
As the articular cartilage of the hip is thin, it is difficult to study with standard MR imaging.
It is difficult to study with a well-designed prospective study because of the low frequency of this injury.
