12 research outputs found
Energy Utilization of Algae Biomass Waste Enteromorpha Resulting in Green Tide in China: Pyrolysis Kinetic Parameters Estimation Based on Shuffled Complex Evolution
Enteromorpha is a species of algae biomass that is spread widely and has resulted in green tides in China in recent years. It was urgent to explore an appropriate method for taking advantage of the ocean waste as an energy supply in the current sustainable development. Pyrolysis, as the first step of thermochemical conversion in energy utilization, was given attention in order to study its behavior based on thermogravimetric experiments over a wide heating-rate range from 5 to 60 K/min. The whole pyrolysis process was divided into three stages: water evaporation, the main components decomposition, and carbonate decomposition. To estimate the detailed kinetic parameters (activation energy, the pre-exponential factor, and reaction order etc.), the Kissinger method was used to establish the original kinetic parameters at different stages and provide the parameter search range for the next heuristic algorithm, and then the Shuffled Complex Evolution optimization algorithm was coupled and first applied to the algae biomass pyrolysis. Eventually, the predicted results of mass loss rate based on the optimized kinetic parameters agreed well with the thermogravimetric experimental data, with the R2 value being up to 0.92 for all the heating rates
The Study on hydrothermal synthesis of ZrO
Nano-ZrO2 has a high atomic active surface and is used as catalyst carrier. The traditional method of preparing ZrO2 nanofibers is electrostatic spinning, which has the problems of high cost and high equipment requirements. In order to solve the shortcomings of traditional preparation methods and prepare excellent ZrO2 nanofibers, a series of ZrO2 nanofibers were prepared based on hydrothermal method by changing the types of reactants, the ratio of reactants to organic additives, solvents, reaction time and other relevant parameters, to explore the growth mechanism of ZrO2 nanofibers, providing a new idea for the preparation of ZrO2 nanofibers on the active surface of altiplano
Crosslinking-modulated direct-current conductivity of XLPE-PS composite via charge trap characteristics
Low direct-current (DC) conductivity is one of the most desired characteristics for crosslinked polyethylene (XLPE) as a high-voltage DC cable insulation material. In this Letter, a correlation between the DC conductivity and cross-linking characteristics of XLPE-polystyrene (PS) composites at 50 C was studied. Experimental results show that by adjusting the cross-linking structure, different trap distribution characteristics for XLPE-PS composites were realized. With the increase in the cross-linking agent content, DC conductivities of XLPE-PS composites tend to decrease, and the introduced average trap depth increases correspondingly. An increase of 0.07 eV for average charge trapdepth in XLPE-PS composites could be acquired in the test range. It is considered that the increase in the average trap depth reduces the carrier mobility, contributing to the reduction of DC conductivity for XLPE-PS composites. Thus, the DC conductivity and average trap depth of XLPE composites show a strong relevance. The results suggest that the interaction between PS particles and the matrix introduced by cross-linking plays a dominant role in determining the charge conduction for XLPE-PS composites
Essential Oils from <i>Zingiber striolatum</i> Diels Attenuate Inflammatory Response and Oxidative Stress through Regulation of MAPK and NF-κB Signaling Pathways
Zingiber striolatum Diels (Z. striolatum), a widely popular vegetable in China, is famous for its medicinal and nutritional values. However, the anti-inflammatory effects of essential oil from Z. striolatum (EOZS) remain unclear. In this study, EOZS from seven regions in China were extracted and analyzed by GC–MS. LPS-induced RAW264.7 cells and 12-O-Tetradecanoylphorbol 13-acetate (TPA)-stimulated mice were used to evaluate the anti-inflammatory effects of EOZS. Results show that 116 compounds were identified in EOZS from seven locations. Samples 2, 4 and 5 showed the best capability on DPPH radical scavenging and NO inhibition. They also significantly reduced the production of ROS, pro-inflammatory cytokines, macrophage morphological changes, migration and phagocytic capability. Transcriptomics revealed MAPK and NF-κB signaling pathways may be involved in the anti-inflammatory mechanism, and the predictions were proven by Western blotting. In TPA-induced mice, EOZS reduced the degree of ear swelling and local immune cell infiltration by blocking the activation of MAPK and NF-κB signaling pathways, which was consistent with the in vitro experimental results. Our research unveils the antioxidant capability and potential molecular mechanism of EOZS in regulating inflammatory response, and suggests the application of EOZS as a natural antioxidant and anti-inflammatory agent in the pharmaceutical and functional food industries
Association of metformin use with fracture risk in type 2 diabetes: A systematic review and meta-analysis of observational studies
Aims: Increasing evidence suggests that metformin can affect bone metabolism beyond its hypoglycemic effects in diabetic patients. However, the effects of metformin on fracture risk in type 2 diabetes mellitus (T2DM) patients remain unclear. A systematic review and meta-analysis were performed in this study to evaluate the association between metformin application and fracture risk in T2DM patients based on previous studies published until June 2021. Methods: A systematic search was performed to collect publications on metformin application in T2DM patients based on PubMed, Embase, Cochran, and Web of Science databases. Meta-analysis was performed by using a random-effects model to estimate the summary relative risks (RRs) with 95% confidence intervals (CIs). Subgroup analyses based on cohort/case-control and ethnicity and sensitivity analyses were also performed. Results: Eleven studies were included in the meta-analysis. Results demonstrated metformin use was not significantly associated with a decreased risk of fracture (RR, 0.91; 95% CI, 0.81–1.02; I2 = 96.8%). Moreover, metformin use also demonstrated similar results in subgroup analyses of seven cohort studies and four case-control studies, respectively (RR, 0.90; 95% CI, 0.76–1.07; I2 = 98.0%; RR, 0.96; 96% CI, 0.89–1.03; I2 = 53.7%). Sensitivity analysis revealed that there was no publication bias. Conclusion: There was no significant correlation between fracture risk and metformin application in T2DM patients. Due to a limited number of existing studies, further research is needed to make a definite conclusion for clinical consensus.</p