One of critical difficulties of molecular dynamics (MD) simulations in protein structure refinement is that the physics-based energy landscape lacks a middle-range funnel to guide nonnative conformations toward near-native states.
In addition, our results underscore the difficulty of the molecular diagnosis of ASD and confirm its genetic heterogeneity.
Discrepancies between microarray- and qPCR-based strategies highlight the difficulty of validating molecular markers of disease.
The small number of participants with immunostaining is due to the difficulty of obtaining molecular data in humans.
The difficulty of elucidating molecular mechanisms is a common problem in herbal extract research and significantly influences the course of novel drug development from herbal extracts.
In more recent studies, the complexity of simply finding the most plausible topologies, and the difficulty of disentangling molecular evolutionary rates and divergence times, resulted in few studies directly concerned with timing the divergence of butterfly clades.
A particular difficulty of the molecular screen was that it is impossible to know, in a single embryo, which of the two edges of the isolated anterior half will express cVg1.
In fact, this approach is one of the causes of the second difficulty since thousands of molecular descriptors are currently extant [13, 14].
One of the difficulties of conducting molecular epidemiologic studies on the basis of historical samples is the lack of balanced, representative datasets.
