Fermentation and induction conditions for recombinant Escherichia coli expressing Thermobifida fusca cutinase were optimized in flasks and 3L fermenter. Surface modification of poly (ethylene terephthalate) fibers with cutinase was also discussed. The results showed that, cutinase yield reached 128 U/mL by adding 2 g/L inducer lactose and 0.5% glycine. In the fed-batch culture in a 3 L fermenter, the maximum biomass cutinase activity was up to 506 U/mL, which is the highest bacterial cutinase activity reported by far. Recombinant cutinase was used to modify polyester fibers and terephthalic acid substance was detected by using UV analysis. The dyeing and wetting properties of cutinase treated fibers were higher than untreated fibers. Combined utilization of cutinase and Triton X-100 can significantly improve the hydrophilicity of polyester. This is the first report of surface modification on polyester fibers by bacterial cutinase.
Actinomycetales ; enzymology ; genetics ; Carboxylic Ester Hydrolases ; biosynthesis ; chemistry ; genetics ; Escherichia coli ; genetics ; metabolism ; Fermentation ; Polyethylene Glycols ; chemistry ; Polyethylene Terephthalates ; Recombinant Proteins ; biosynthesis ; genetics ; Surface Properties

Objective To explore whether the ability of intertemporal choice is impaired in schizophrenic patients and in their unaffected siblings.Methods Twenty-five schizophrenia patients,twenty-five unaffected siblings of patients and thirty healthy controls were recruited in the study."Delay-discounting" task and a battery of cognitive neuropsychological assessment were used to examine the intertemporal decision-making.Results (1) the value of k was ((0.005±0.009 in schizophrenia,0.011±0.014 in unaffected siblings and 0.024±0.029 in healthy controls,respectively.There was significant difference in k value among these three groups (F=9.487,P＜0.001).There were significant differences in k value between patients group and healthy controls,and between unaffected siblings and healthy controls (P＜0.05).There was no significant difference between schizophrenia and their unaffected siblings (P＜0.05).(2) Pearson correlation analysis not showed any relationship between neuropsychological test and the value of k.Conclusion The ability of intertemporal choices is impaired in schizophrenia and their unaffected siblings to a great degree.

Objective To investigate the effect of high-definition transcranial direct current stimula-tion on visual spatial working memory in patients with schizophrenia. Methods Sixty-six patients with schizophrenia were enrolled in a randomized,double-blind,placebo-controlled study. The subjects were ran-domized into a true stimulation group of 33 patients and a placebo control group of 33 patients,each patient only received one stimulation. After receiving a stimulus,the left dorsolateral prefrontal lobe was stimulated by high-precision transcranial direct current. The true stimulation group was stimulated with a current of 1. 5 mA for 20 min. The control group used pseudo-stimulation,and only the current was passed within 30 s of the beginning and the end of the stimulation. Both groups completed the neuropsychological background test and the n-back task before stimulation,and the stimulation was performed after five days. After the stimula-tion,the two groups completed the n-back task again,and compared the Changes in grades to reflect changes in working memory before and after the pseudo-stimulation. Results Before the stimulation,the response rate of the 3-back task was compared with that of the control group ((0. 32±0. 21),(0. 32±0. 22)),the true stimulation group ((0. 28 ± 0. 19), ( 0. 35 ± 0. 21)), and the difference was statistically significant ( F=5. 298,P=0. 025). Conclusion Using high-definition transcranial direct current stimulation to stimulate the left dorsolateral prefrontal cortex using can improve the visual memory function of patients. In the future,this technique can be applied to the cognitive promotion of memory impairment in patients with schizophrenia.