The phrase "a severe block in" is correct and usable in written English.
It can be used to describe a significant obstacle or hindrance in a process, situation, or system.
Example: "The team faced a severe block in their project due to unexpected technical difficulties."
Alternatives: "a major obstacle in" or "a significant barrier in".
However, as with many men diagnosed with DAZ gene deletions, DAZL-deficient rats were sterile due to a severe block in spermatogenesis [17].
These mutant mice displayed a severe block in B cell development at the differentiation from, so called, T1 to T2 B cells in the spleen, whereas the development of B-1 B cells appeared to be unaffected.
While mice lacking individual Vav family proteins show partial to no defects in T lymphocytes, VavNULL mice show a severe block in T cell development [29], [38], [39], [40], [55].
In a similar knockout mouse strain of survivin gene (lck-Cre/survivinfl/fl), for example, loss of survivin at this stage leads to a severe block in the DN to DP transition and more than 10-fold drop of the number of thymocytes [17], [18].
The hallmark of all AML types is a severe block in myeloid differentiation.
Somewhat analogously, deletion of VEGF-C results in a severe block in the development of the lymphatic system.
In contrast, the ring-closed PdG adduct 14 represented a severe block to synthesis by pol κ at both the insertion and the extension step.
The main obvious functional changes that occur with the progression of CML are the severe block in differentiation, apoptosis and acceleration in proliferation.
S1P is recognized by S1P receptor-1 (S1P1) expressed on lymphocytes, and deficiency in S1P1 results in a severe egress block from the thymus and lymph nodes [6].
In contrast to these knockouts, we did not observe a lower number of ovulation in the conditional deletion of Hsp90b1 but we found a more severe developmental block in comparison to ZP1 mutant embryos that reached the 2-cell stage or Mgat1 ones that were able to implant [21], [22].
It takes a moment to get over the shock of its Soviet-style regimentation, where the identical rooms are located in severe blocks (shades of Prisoner Cell Block H) on municipal staircases, where every room has its own democratically identical balcony overlooking the yachts in the bay and most meals are help-yourself-comrade buffets.
