Engineering the plastic degradation enzyme Ple629 from marine consortium to improve its thermal stability / 生物工程学报

Petrochemical-derived polyester plastics such as polyethylene terephthalate (PET) and polybutylene adipate terephthalate (PBAT) have been widely used. However, the difficulty to be degraded in nature (PET) or the long biodegradation cycle (PBAT) resulted in serious environmental pollution. In this connection, treating these plastic wastes properly becomes one of the challenges of environment protection. From the perspective of circular economy, biologically depolymerizing the waste of polyester plastics and reusing the depolymerized products is one of the most promising directions. Recent years have seen many reports on polyester plastics degrading organisms and enzymes. Highly efficient degrading enzymes, especially those with better thermal stability, will be conducive to their application. The mesophilic plastic-degrading enzyme Ple629 from the marine microbial metagenome is capable of degrading PET and PBAT at room temperature, but it cannot tolerate high temperature, which hampers its potential application. On the basis of the three-dimensional structure of Ple629 obtained from our previous study, we identified some sites which might be important for its thermal stability by structural comparison and mutation energy analysis. We carried out transformation design, and performed expression, purification and thermal stability determination of the mutants. The melting temperature (Tm) values of mutants V80C and D226C/S281C were increased by 5.2 ℃ and 6.9 ℃, respectively, and the activity of mutant D226C/S281C was also increased by 1.5 times compared with that of the wild-type enzyme. These results provide useful information for future engineering and application of Ple629 in polyester plastic degradation.

Application of Rehabilitation Integrated System in Stroke Patients / 中国康复理论与实践

Objective To observe the significance of rehabilitation integrated system for stroke patients. Methods From October, 2013 to June, 2015, 95 stroke patients were divided randomly into experimental group (n=48) and control group (n=47). The experimental group received rehabilitation under the guide of rehabilitation integrated system, while the control group in the routine process. They were assessed with simplified Fugl-Meyer Assessment (FMA) and Barthel Index (BI) before and 3 months after treatment. The satisfaction was also inves-tigated. Results There was no significant difference between groups in the differences of scores of FMA and BI before and after treatment (t0.05), while the satisfaction was higher in the experimental group (t=4.287, P<0.01). Conclusion The application of rehabilitation integrated system may improve the process of treatment and the efficiency of management, and result in more satisfaction of the stroke pa-tients.