Finite element simulation and experimental validation of thermal damage to isolated porcine skin tissue by femtosecond laser welding.

The welding effect of the laser on skin tissue is reduced by thermal damage to skin tissue, and greater thermal damage to skin tissue caused by the laser is prevented by predicting thermal damage. In this paper, a finite element model is established for the temperature field of skin tissue scanned by a femtosecond laser to obtain the influence of laser process parameters and scanning path on the thermal damage parameters of skin tissue and the thermal damage area, and verified experimentally. The results show that the established finite element model is accurate and can accurately reflect the temperature distribution during the process of femtosecond laser welding of porcine skin tissues; used to predict the thermal damage parameters of the skin tissues and the thermal damage area; and provide guidance for the study of the femtosecond laser welding of the skin tissues process to obtain the optimal process parameters.

Effect of femtosecond laser process parameters on the thermal denaturation degree of skin tissue.

The influence of femtosecond laser parameters on the degree of thermal denaturation was studied experimentally. The relationship between the degree of thermal denaturation and the characteristic parameters of skin microstructure and the secondary structure of skin tissue proteins in characterizing the degree of thermal damage was analyzed. The results showed the interaction of laser power, laser power, and scanning speed had a significant effect on the degree of thermal denaturation; greater degrees of thermal denaturation were associated with larger second-order moments of the texture angle of the skin microtissue and smaller entropy values and contrast, indicating a greater degree of thermal damage; and higher peak temperature, the lower peak intensity of Raman spectra, decrease in the percentage area of α-helix fitted curves and increase in the percentage area of ß-sheet and ß-turn fitted curves indicate that the protein is denatured to a large extent that means thermal damage is large.

Experimental study on the effect of scanning path on skin tissue properties of femtosecond laser welding.

To study the influence pattern of femtosecond laser scanning path on the welding effect of skin tissue, this experiment analyzed the influence of scanning path on the surface morphology, degree of thermal damage, tensile strength, and microstructure of skin samples after skin attachment by designing nine scanning paths to weld skin tissue. The results showed that the skin samples connected by interrupted parallel mattress eversion sewing method with d = 0.2 mm showed no obvious color changes in morphology, the skin samples were connected on both front and back sides, the tensile strength was the highest, reaching 12.80 N/cm2 , the thermal damage parameter was low at 1.08 × 10-2 , the microstructure had obvious directionality, and the texture was clear and uniformly distributed.

Research on the effect of process parameters on the performance of femtosecond laser-bonded skin microstructure.

In this paper, the effect of the femtosecond laser process parameters on the texture characteristics of the microstructure was analyzed with the response surface method. The correspondence between the temperature of skin during laser bonding and microscopic tissue texture characteristics parameters was explored. The results show that the three process parameters of laser power, scanning speed, and scanning times and the interaction between the parameters have different patterns of influence on the four texture characteristics parameters of skin microstructure angular second-order moments, entropy, contrast, and relevance. Angular second-order moments and relevance of skin microstructure textures increase with increasing temperature, while entropy values and contrast decrease. It provides another way to evaluate the performance of femtosecond laser-bonded skin with microstructure.

In Vitro and In Vivo Antioxidant Effects of Polysaccharides from Nameko Medicinal Mushroom, Pholiota nameko SW-01 (Higher Basidiomycetes).

Extra- (EPS) and intracellular polysaccharides (IPS) from Pholiota nameko SW-01 were extracted, and in vitro and in vivo antioxidant effects were processed. Briefly, the in vitro antioxidant results indicated that the inhibition effects of IPS at a dose of 500 mg/L on superoxide anions, hydroxyl radicals, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals were 63.24 ± 1.12%, 53.11 ± 2.92%, and 59.33 ± 9.37%, which were 7.70%, 14.84%, and 11.40% higher than those of EPS, and 9.79%, 20.32%, and 4.59% higher than those of butylated hydroxytoluene (BHT), respectively. The reducing power of IPS reached 0.593 ± 0.21 (absorbance at 700 nm), which was 11.30% higher than that of EPS and 15.51% higher than that of BHT. In vivo antioxidant results proved that both IPS and EPS significantly upregulated the enzyme activities of superoxide dismutase (SOD), GSH peroxide (GSH-Px), catalase (CAT), and alanine transaminase (ALT). In addition, glycosidic bond types of EPS and IPS were primarily characterized. The findings indicate the potential antioxidant effects of polysaccharide extract from Ph. Nameko. Thus, this species has potential applicability as an antioxidant agent and should be studied further.

Enzymatic and acidic degradation effect on intracellular polysaccharide of Flammulina velutipes SF-08.

The intracellular polysaccharide (IPS) from Flammulina velutipes SF-08 mycelia was isolated and degraded by enzyme and acid. IPS and its derivative were purified by DEAE-52 cellulose chromatography, and five fractions were obtained. The structural features and antioxidant activities in vitro of the isolated fractions were evaluated. On the basis of chemical composition and antioxidant ability analyses, rhamnose as the main monosaccharide might contribute to the strongest antioxidant capacity. The in vivo results showed that IPS significantly enhanced the activities of anti-aging enzymes, such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity, and reduced the content of lipid peroxidantion (LPO). These results suggested that IPS should be a potent natural polymer and can be developed to be novel functional food.

Antihyperlipidemic and hepatoprotective activities of mycelia zinc polysaccharide from Pholiota nameko SW-02.

The objective of this study was to set up the mice hyperlipidemic model to observe the pharmacological effects of mycelia zinc polysaccharide (MZPS) of Pholiota nameko SW-02 on lipid metabolism and oxidative stress. IR spectrum of MZPS showed typical structure of fungi polysaccharides. The zinc content, determined by flame atomic absorption spectrometry, was 16.68±0.73 mg/g. By the analysis of GC and HPGPC, the MZPS was composed of glucose, mannose, galactose and arabinose, and the weight-average molecular weight was 3.64×10(4) Da. The model of hyperlipidemic mice was established by perfusion high-fat emulsion, which caused hyperlipidemia and an increase in oxidative stress. The results showed that the supplementation of MZPS could improve blood lipid levels (TC, TG, HDL-C, LDL-C and VLDL-C), liver lipid levels (TC and TG) and antioxidant status (SOD, T-AOC, MDA and LPO). In addition, the histopathological observations of mice livers and the glutamate pyruvate transaminase activities indicated that the MZPS could attenuate liver cell injury. These results demonstrated that the MZPS might be effective in lowering lipid and protecting against high-fat diet-induced hyperlipidemia and non-alcoholic fatty liver.

Purification and antioxidant activities of intracellular zinc polysaccharides from Pleurotus cornucopiae SS-03.

Intracellular zinc polysaccharides (IZPS) from Pleurotus cornucopiae SS-03 were extracted and purified, and three subfractions (IZPS-1, IZPS-2, and IZPS-3) were separated by DEAE-52 cellulose anion-exchange column chromatography. They showed certain scavenging effects on superoxide anion (O2(*-)) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and positive rising of reducing power in vitro. All the subfractions were found upregulated the enzyme activities of superoxide dismutase (SOD), GSH peroxide (GSH-Px) and catalase (CAT) significantly, decreased the contents of malondialdehyde (MDA) and lipid peroxidation (LPO) remarkably in vivo. In addition, five monosaccharides components, including rhamnose, xylose, mannose, glucose, and galactose with the molar ratio of 1.65:0.05:1:1.50:1.07 and contents of 29.25%, 0.78%, 19.45%, 29.84%, and 20.67%, were investigated by gas chromatography.

Production and in vivo antioxidant activity of Zn, Ge, Se-enriched mycelia by Cordyceps sinensis SU-01.

Cordyceps sinensis, a traditionally edible and medicinal fungus in China, cannot be artificially solid-cultured. Zinc (Zn), germanium (Ge), and selenium (Se) are the essential trace elements for human body. In this work, C. sinensis SU-01 was cultivated in liquid medium simultaneously containing Zn, Ge, and Se. The bioactive ingredients and in vivo antioxidant activities of Zn, Ge, Se-enriched mycelia (ZGSM) of C. sinensis SU-01 were investigated. Under the determined conditions, the Zn, Ge, and Se contents of ZGSM were 2543.16 ± 158.92, 1873.85 ± 81.82, and 1260.16 ± 107.12 µg/g, respectively. The optimal concentrations of Zn, Ge, and Se had a positive effect on biosynthesis of protein, polysaccharide, cordycepic acid, and amino acids. The activities of glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) of mice blood were 3.72 ± 0.15 and 28.74 ± 2.53 % higher than that of control, respectively, and the content of malondialdehyde (MDA) was 41.01 ± 3.66 % lower than that of control.

Extraction and in vitro antioxidant activity of exopolysaccharide by Pleurotus eryngii SI-02

The extraction parameters for Pleurotus eryngii SI-02 exopolysaccharide (EPS) produced during submerged culture were optimized using response surface methodology (RSM). The optimum conditions for EPS extraction were predicted to be, precipitation time 20.24 h, ethanol concentration 89.62% and pH 8.17, and EPS production was estimated at 7.27 g/L. The actual yield of EPS under these conditions was 7.21 g/L. The in vitro antioxidant results of the EPS showed that the inhibition effects of EPS at a dosage of 400 mg/L on hydroxyl, superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals were 59.63 ± 3.72%, 38.69 ± 2.59%, and 66.36 ± 4.42%, respectively, which were 12.74 ± 1.03%, 8.01 ± 0.56%, and 12.19 ± 1.05% higher than that of butylated hydroxytoluene (BHT), respectively. The reducing power of EPS of P. eryngii SI-02 was 0.98 ± 0.05, 60.66 ± 5.14% higher than that of BHT. The results provide a reference for large-scale production of EPS by P. eryngii SI-02 in industrial fermentation and the EPS can be used as a potential antioxidant which enhances adaptive immune responses.

Extraction and in vitro antioxidant activity of exopolysaccharide by Pleurotus eryngii SI-02.

The extraction parameters for Pleurotus eryngii SI-02 exopolysaccharide (EPS) produced during submerged culture were optimized using response surface methodology (RSM). The optimum conditions for EPS extraction were predicted to be, precipitation time 20.24 h, ethanol concentration 89.62% and pH 8.17, and EPS production was estimated at 7.27 g/L. The actual yield of EPS under these conditions was 7.21 g/L. The in vitro antioxidant results of the EPS showed that the inhibition effects of EPS at a dosage of 400 mg/L on hydroxyl, superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals were 59.63 ± 3.72%, 38.69 ± 2.59%, and 66.36 ± 4.42%, respectively, which were 12.74 ± 1.03%, 8.01 ± 0.56%, and 12.19 ± 1.05% higher than that of butylated hydroxytoluene (BHT), respectively. The reducing power of EPS of P. eryngii SI-02 was 0.98 ± 0.05, 60.66 ± 5.14% higher than that of BHT. The results provide a reference for large-scale production of EPS by P. eryngii SI-02 in industrial fermentation and the EPS can be used as a potential antioxidant which enhances adaptive immune responses.

Production and in vitro antioxidant activity of exopolysaccharide by a mutant, Cordyceps militaris SU5-08.

Cordyceps militaris SU5-08 was derived from an initial strain (C. militaris SU5) by ultraviolet mutagenesis of protoplasts, and the extraction parameters for C. militaris SU5-08 exopolysaccharide (EPS) produced during submerged culture were optimized. The extraction rate of EPS was 1919.16±165.27 mg/l, which was 120.38±11.36% higher than that of C. militaris SU5. The in vitro scavenging effects of EPS of C. militaris SU5-08 on hydroxyl, superoxide anion and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals at a dosage of 5 g/l were 63.64±3.52%, 75.27±5.16%, and 6.46±5.03%, respectively. The reducing power of EPS of C. militaris SU5-08 was 0.21±0.01. The results suggest that the EPS of C. militaris SU5-08 can be used as a potential antioxidant which enhances adaptive immune responses.