Sentence examples for are difficult to prepare from inspiring English sources

This enabled the preparation of extended PNA sequences which are difficult to prepare by standard solid-phase methods.

Primary amines having a tertiary alkyl group (R3CNH2) are difficult to prepare with most methods but are made industrially by the Ritter reaction.

Usually the ligands are difficult to prepare or very expensive.

It should be pointed out that pure Ni nanoparticles are difficult to prepare because they are easily oxidized.

Reference substances of NHS esters of mPEGs for this new method are difficult to prepare, which is more pronounced with chromatographic methods.

Transducers are generally placed in contact with the samples which are often cubes with parallel faces that are difficult to prepare.

The result, though, is a team that is difficult to prepare for.

"The Champions League is not easy but it is the game afterwards that is difficult to prepare for.

But without knowing a site is a target beforehand, it is difficult to prepare for an attack.

Given that the new date was so close to the Christmas and New Year's holidays, Mr. Strassberg argued, it would be difficult to prepare witnesses.

"It is difficult to prepare for class," Ms. Issa said, "and we are trying to cope as best as we can in this environment in order to create a sense of normalcy for them".