A novel chitosan derivant, N-octyl-N-arginine chitosan (OACS) with a mimetic structure of cell-penetrating peptides was synthesized by introducing hydrophilic arginine groups and hydrophobic octyl groups to the amino-group on chitosan's side chain. Structure of the obtained polymer was characterized by FT-IR and 1H NMR. The substitution degree of octyl and arginine groups was calculated through element analysis and spectrophotometric method, separately. The critical micelle concentration of OACS was 0.12 - 0.27 mgmL(-1) tested by fluorescence spectrometry. The solubility test showed OACS could easily dissolve in pH 1 - 12 solutions and self-assemble to form a micelle solution with light blue opalescence. The OACS micelles have a mean size of 158.4 - 224.6 nm, polydisperse index of 0.038 - 0.309 and a zeta potential of +19.16 - +30.80 mV determined by malvern zetasizer. AFM images confirmed free OACS micelle has a regular sphere form with a uniform particle size. MTT test confirmed that OACS was safe in 50 - 1 000 micromol-L(-1). The result of HepG2 cell experiment showed that the cell internalization of OACS micelles enhanced with increased substitution degree of arginine by 40 folds compared to chitosan. Thus, OACS micelles were a promising nano vehicle with permeation enhancement and drug carrier capability.

Objective To investigate the prevalence of anxiety and depression among the persons with disabilities in Shanghai and the factors related to them. Methods From November to December, 2014, 731 persons with disabilities were consecutively enrolled in this cross-sectional study. They were assessed with Self-rating Anxiety Scale (SAS) and the Self-rating Depression Scale (SDS). Binary Logistic regression analysis was employed to reveal potential related factors of anxiety and depression. Results The prevalence rates of anxiety and depression among the disabled in Shanghai were 9.58%and 8.48%, respectively. The duration (OR=0.967, P<0.05) and severity (OR<1, P<0.05) of disability were associated with depression, whereas retiral (OR=2.047, P<0.05), living alone or in care unit (OR=3.073, P<0.01) and duration of disability (OR=0.956, P<0.01) were associated with anxiety. Conclusion The frequency of anxiety and depression is mild among the persons with disabilities in Shanghai, and a special intervention is needed.

Penicillium decumbens T. is an important filamentous fungus for the production of cellulases to effectively degrade lignocellulose for second generation biofuel production. In order to enhance the capability of Penicillium decumbens to produce cellulases, we constructed a creB (a deubiquitinating enzyme encoding gene) deletion cassette, and generated a creB knockout strain with homologous double crossover recombination. This mutation resulted in a detectable decrease of carbon catabolite repression (CCR) effect. The filter paper activity, endoglucanase activity, xylanase activity and exoglucanase activity of the deltacreB strain increased by 1.8, 1.71, 2.06 and 2.04 fold, respectively, when comparing with the parent strain Ku-39. A 2.68 fold increase of extracellular protein concentration was also observed. These results suggest that the deletion of creB results in CCR derepression. These data also suggest that CREB influences cellulase production of Penicillium decumbens. In generation, this study provides information that can be helpful for constructing cellulase hyper-producing strain.
Cellulase ; biosynthesis ; Endopeptidases ; genetics ; metabolism ; Gene Knockout Techniques ; Lignin ; metabolism ; Mutant Proteins ; metabolism ; Penicillium ; enzymology ; genetics ; Recombination, Genetic ; Ubiquitinated Proteins ; genetics ; Ubiquitination

In this study, the mature peptide sequence of a pectin lyase gene A was amplified from Aspergillus niger strain EIM-6 by using RT-PCR reverse transcription technique. The cloned gene was then inserted into a Pichia pastoris expression vector pPIC9k to produce the recombinant expression plasmid pPIC9K-pelA. By using electric shocks, we successfully transformed the recombinant pPIC9K-pelA into Pichia pastoris GS115. The activity of the engineered strain reached to 2.3 U/mL after induction with the final concentration of 1.5% methanol. SDS-PAGE analysis revealed that the pPIC9K-pelA transformant had an additional protein band of approximately 38 kD, which was not present in the control. There were no significant differences between the recombinant and native pectin lyase with regard to their hydrolysis activities.
Aspergillus niger ; enzymology ; genetics ; Electroporation ; Pichia ; genetics ; metabolism ; Polysaccharide-Lyases ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction