Cross-linked enzymes, produced by mixing an aqueous solution of the enzyme with an aqueous solution of glutaraldehyde, were already known in the 1960s but were generally difficult to handle, gelatinous materials exhibiting low activity, poor reproducibility, and low stability and shelf life.
Low generation poly amidoamine) (PAMAM) dendrimers are less cytotoxic, but it is generally difficult to render them with thermosensitive properties due to the lack of surface terminal groups.
In order to understand the scale and nature of inequalities in intra-urban mobility we need reliable income data, but this is generally difficult to collect in household surveys.
The available literature on the RCF testing of various types of overlay coatings is considerable, but it is generally difficult to synthesize all of the results to obtain a comprehensive understanding of the parameters which can have a significant effect on a coating's resistance to rolling contact fatigue.
But, it is generally difficult to recognize secondary faults which may be masked due to larger structures.
This may be the case for caregivers experiencing high levels of strain, but this group is generally difficult to approach and less likely to participate in any type of survey.
Also, MaxQuant [124] creates text files as output that can open in Microsoft Excel, but analysis of results is generally difficult since no protein-specific visualization can be created.
Identification of discrete active fault surfaces among a number of possible discontinuity surfaces around an active fault zone is generally difficult, but this study showed that not only the megasplay fault zone but also several faults in its hangingwall may also currently have the potential to reactivate at site C0004 (see arrows in Figure 4).
Testing the separate functioning of the perceptions and sanctioning steps of electoral accountability for misconduct is generally difficult, but our empirical strategy with regard to the UK expenses scandal allows us to overcome many of these difficulties.
"This and many other earthquakes are obviously human-triggered, but distinguishing natural from triggered earthquakes is generally difficult," he said.
