Exploration of the Product Specificity of chitosanase CsnMY002 and Mutants Using Molecular Dynamics Simulations.

Chitosanase CsnMY002 is a new type of enzyme isolated from Bacillus subtilis that is used to prepare chitosan oligosaccharide. Although mutants G21R and G21K could increase Chitosan yield and thus increase the commercial value of the final product, the mechanism by which this happens is not known. Herein, we used molecular dynamics simulations to explore the conformational changes in CsnMY002 wild type and mutants when they bind substrates. The binding of substrate changed the conformation of protein, stretching and deforming the active and catalytic region. Additionally, the mutants caused different binding modes and catalysis, resulting in different degrees of polymerization of the final Chitooligosaccharide degradation product. Finally, Arg37, Ile145 ~ Gly148 and Trp204 are important catalytic residues of CsnMY002. Our study provides a basis for the engineering of chitosanases.

A randomized control study: The effectiveness of multimedia education on self-care and quality of life in patients with enterostomy.

Colorectal cancer is typically treated through surgery, and self-care skills play a crucial role in disease adaptation and quality of life improvement. Therefore, this study aimed to investigate the effectiveness of a multimedia patient education intervention on enhancing the self-care and quality of life among patients with a postoperative stoma as well as on establishing an easy-to-use ostomy self-care skills assessment. The sample comprised 108 patients with new ostomies who were randomly assigned to two groups. Data were collected from June 2018 to March 2019. The conventional education service program group received individual education in the hospital environment, consisting of four 3-h sessions delivered over 4 consecutive days. The multimedia group viewed a multimedia educational program using a laptop. Data were collected at baseline and 3 months after the intervention using a demographic questionnaire, an ostomy self-care ability scale and the Stoma Quality of Life Scale. Before the intervention, there were no significant differences in self-care ability and quality of life scores between the two groups (p = 0.764 and p = 0.466, respectively). However, 3 months after the intervention, the group that received the multimedia software intervention showed significantly higher self-care ability and quality of life scores compared to the group that received conventional education services (p < 0.001). When a set threshold is reached, self-care ability and a good quality of life can be met. The threshold value of the ostomy self-care skill scale was determined to be 20 points, resulting in a sensitivity of 77.8% and a specificity of 75.5%. The results indicate that the multimedia education program enhanced home self-care ability and quality of life among patients with enterostomy.

Cytoplasmic DNAs: Sources, sensing, and roles in the development of lung inflammatory diseases and cancer.

Cytoplasmic DNA is emerging as a pivotal contributor to the pathogenesis of inflammatory diseases and cancer, such as COVID-19 and lung carcinoma. However, the complexity of various cytoplasmic DNA-related pathways and their crosstalk remains challenging to distinguish their specific roles in many distinct inflammatory diseases, especially for the underlying mechanisms. Here, we reviewed the latest findings on cytoplasmic DNA and its signaling pathways in inflammatory lung conditions and lung cancer progression. We found that sustained activation of cytoplasmic DNA sensing pathways contributes to the development of common lung diseases, which may result from external factors or mutations of key genes in the organism. We further discussed the interplays between cytoplasmic DNA and anti-inflammatory or anti-tumor effects for potential immunotherapy. In sum, this review aids in understanding the roles of cytoplasmic DNAs and exploring more therapeutic strategies.

Enzymatic hydrolysis of Alaska pollack (Theragra chalcogramma) skin and antioxidant activity of the resulting hydrolysate.

BACKGROUND: Fish skin, a by-product of the food industry, contains a large amount of collagen. However, only a small proportion of fish skin is used in the production of leather materials and animal feedstuffs, most of it being discarded. The aims of this study were to prepare peptides from Alaska pollack (Theragra chalcogramma) skin by enzymatic hydrolysis and to evaluate the antioxidant activity of the resulting hydrolysate. RESULTS: Protamex was the most efficient enzyme for preparing antioxidant peptides from Alaska pollack skin. The optimal hydrolysis conditions were as follows: hydrolysis time 8 h; enzyme/substrate ratio 2:1000; skin/water ratio 1:6; temperature 55 degrees C; pH 6.0. Under these conditions the highest yield of peptides was 83.44%, with 85.95% of the hydrolysate being mainly composed of oligopeptides with molecular weights ranging from 180 to 1000 Da. The hydrolysate showed 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, with an IC(50) value of 2.5 mg mL(-1), and its reducing power was 0.14 at 1 mg mL(-1), 53.8% of that of reduced glutathione at the same concentration. CONCLUSION: This study demonstrated that the hydrolysate of Alaska pollack skin was mainly composed of oligopeptides with two to eight amino acid residues and possessed antioxidant activity.

Effects of flash freezing, followed by frozen storage, on reducing Vibrio parahaemolyticus in Pacific raw oysters (Crassostrea gigas).

This study investigated the effects of flash freezing, followed by frozen storage, on reducing Vibrio parahaemolyticus in Pacific raw oysters. Raw Pacific oysters were inoculated with a five-strain cocktail of V. parahaemolyticus at a total level of approximately 3.5 x 10(5) most probable number (MPN) per gram. Inoculated oysters were subjected to an ultralow flash-freezing process (-95.5 degrees C for 12 min) and stored at -10, -20, and -30 degrees C for 6 months. Populations of V. parahaemolyticus in the oysters declined slightly by 0.22 log MPN/g after the freezing process. Subsequent storage of frozen oysters at - 10, -20, and -30 degrees C resulted in considerable reductions of V. parahaemolyticus in the oysters. Storing oysters at -10 degrees C was more effective in inactivating V. parahaemolyticus than was storage at -20 or -30 degrees C. Populations of V. parahaemolyticus in the oysters declined by 2.45, 1.71, and 1.45 log MPN/g after 1 month of storage at -10, -20, and -30 degrees C, respectively, and continued to decline during the storage. The levels of V. parahaemolyticus in oysters were reduced by 4.55, 4.13, and 2.53 log MPN/g after 6 months of storage at -10, -20, and -30 degrees C, respectively. Three process validations, each separated by 1 week and conducted according to the National Shellfish Sanitation Program's postharvest processing validation-verification interim guidance for Vibrio vulnificus and Vibrio parahaemolyticus, confirmed that a process of flash freezing, followed by storage at -21 +/- 2 degrees C for 5 months, was capable of achieving greater than 3.52-log (MPN/g) reductions of V. parahaemolyticus in half-shell Pacific oysters.

[Pollution Characteristics and Emission Coefficients of Volatile Organic Compounds from the Packaging and Printing Industry in Zhejiang Province].

This paper presents the raw material composition and VOC treatment status of the packaging and printing industry in Zhejiang Province based on the survey data obtained in 2015 of 254 packaging and printing enterprises. To analyze the emission characteristics and calculate the emission coefficients of the packaging and printing industry, 100 typical enterprises were further screened according to different printing processes. The results showed that about two-thirds of packaging and printing enterprises failed to effectively dispose of VOCs; meanwhile, solvent-based materials were still commonly used in the packaging and printing industry. The main emission pollution factors of VOCs in the packaging and printing industry were ethyl acetate, isopropanol, ethanol, propyl acetate, and n-butyl acetate. The VOC emission coefficient of the packaging and printing industry in Zhejiang Province was 0.485 kg·kg-1, of which the gravure printing was the primary source with VOCs emission coefficient of 0.634 kg·kg-1. Compared with the material balance method, the error value from the emission coefficient method was less than 15%.