OBJECTIVETo investigate the basic factors of the progress amplitude of hearing and speech rehabilitation effect of preschool deaf children with cochlear implants, and provide guidance for the improvement and optimization of rehabilitation strategies.

METHODUsing the standard hearing and language assessment tools, tracked and evaluated 1 422 CI preschool deaf children for a period of one year, and calculated the effect of hearing and speech rehabilitation, carried out the correlation analysis and variance analysis among different grouping variables.

RESULT(1) There was a negative correlation (P<0.01) between the rehabilitation effect and cochlear implantation age, existed the different degree of positive correlation (P<0.01) between the rehabilitation effect and parents cultural level, but no correlation between the rehabilitation effect and parents hearing status.(2) Father's education level, in comparison to mother's education level, had greater impact on the children rehabilitation effect.(3)There was positive correlation(r=0.689, P<0.01) between the progress amplitude of hearing and speech rehabilitation effect. (4) The progress amplitude of auditory and language rehabilitation effect of 2-3 years old group was the highest value(the progress amplitude of hearing and speech recognition rate reached 77.5%, the progress amplitude of language age progress rate reached 2.02 years old), and there were significant differences (P<0.05) between over 3 years old groups.

CONCLUSIONS(1) To expect the better progress amplitude of rehabilitation effect, cochlear implant age should not be more than 3 years old. (2) Father's effect in the process of rehabilitation is more helpful for deaf children's learning enthusiasms.

Age Factors ; Child, Preschool ; Cochlear Implantation ; Cochlear Implants ; Deafness ; rehabilitation ; Hearing ; Hearing Tests ; Humans ; Language ; Speech Perception

p-coumaric acid is an important natural phenolic compound with a variety of pharmacological activities, and also a precursor for the biosynthesis of many natural compounds. It is widely used in foods, cosmetics and medicines. Compared with the chemical synthesis and plant extraction, microbial production of p-coumaric acid has many advantages, such as energy saving and emission reduction. However, the yield of p-coumaric acid by microbial synthesis is too low to meet the requirements of large-scale industrial production. Here, to further improve p-coumaric acid production, the directed evolution of tyrosine ammonia lyase (TAL) encoded by Rhodotorula glutinis tal gene was conducted, and a high-throughput screening method was established to screen the mutant library for improve the property of TAL. A mutant with a doubled TAL catalytic activity was screened from about 10,000 colonies of the mutant library. There were three mutational amino acid sites in this TAL, namely S9Y, A11N, and E518A. It was further verified by a single point saturation mutation. When S9 was mutated to Y, I or N, or A11 was mutated to N, T or Y, the catalytic activity of TAL increased by more than 1-fold. Through combinatorial mutation of three types of mutations at the S9 and A11, the TAL catalytic activity of S9Y/A11N or S9N/A11Y mutants were significantly higher than that of other mutants. Then, the plasmid containing S9N/A11Y mutant was transformed into CP032, a tyrosine-producing E. coli strain. The engineered strain produced 394.2 mg/L p-coumaric acid, which is 2.2-fold higher than that of the control strain, via shake flask fermentation at 48 h. This work provides a new insight for the biosynthesis study of p-coumaric acid.
Ammonia-Lyases/genetics* ; Escherichia coli/genetics* ; Propionates ; Rhodotorula ; Tyrosine/genetics*