However, the application of bacterial-derived enzymes as complements to fungal enzyme cocktails is severely limited by the still unsolved difficulty of expressing them in filamentous fungi.
Therefore, a screening for thermostable xylanases in filamentous fungi will directly meet the demands when compared to bacteria-derived enzymes, which sill exit unsolved difficulty of expressing them in filamentous fungi.
Among these problems, the perfect-reconstruction (PR) theory of the 2D DFT modulated filter bank with arbitrary modulation and decimation matrices remains an unsolved difficulty, which is the focus of this paper.
After identifying unsolved practical difficulties in administration of EN using volume syringes, a new device to overcome such technical difficulties was proposed.
Apart from unsolved technical difficulties, much more basic research in embryonic stem cell research is needed.
Interval QTL mapping also has an unsolved statistical difficulty when it is used with a high-density linkage map.
In sportswear industry, body odors generated, in particular, in shoes are a big issue that remains unsolved because of the difficulties to destroy odors and bacteria at the same time.
A better classification of cancer types, the networking of cancer registries, and the increasing population coverage for cancer registration are unfortunately accompanied, due to unsolved technical and organizational difficulties, by publishing of cancer register reports with a lag of several years.
However, the exact structures of many proteins remain unsolved due to the practical difficulties in the crystallization process for X-ray crystallography or resolving structures with NMR [ 2].
Despite much research, many questions regarding the origin and evolution of spliceosomal introns remain unsolved, partly due to the difficulty of inferring ancestral gene structures.
