Investigations on the Antifungal Effect of Nerol against Aspergillus flavus

The antifungal efficacy of nerol (NEL) has been proved against Aspergillus flavus by using in vitro and in vivo tests. The mycelial growth of A. flavus was completely inhibited at concentrations of 0.8 μL/mL and 0.1 μL/mL NEL in the air at contact and vapor conditions, respectively. The NEL also had an evident inhibitory effect on spore germination in A. flavus along with NEL concentration as well as time-dependent kinetic inhibition. The NEL presented noticeable inhibition on dry mycelium weight and synthesis of aflatoxin B1 (AFB1) by A. flavus, totally restraining AFB1 production at 0.6 μL/mL. In real food system, the efficacy of the NEL on resistance to decay development in cherry tomatoes was investigated in vivo by exposing inoculated and control fruit groups to NEL vapor at different concentration. NEL vapors at 0.1 μL/mL air concentration significantly reduced artificially contaminated A. flavus and a broad spectrum of fungal microbiota. Results obtained from presented study showed that the NEL had a great antifungal activity and could be considered as a benefit and safe tool to control food spoilage

Investigating the simultaneous fracture propagation from multiple perforation clusters in horizontal wells using 3D block discrete element method

Multi-cluster horizontal well fracturing is one of the key technologies to develop the unconventional reservoirs such as shales. However, the field data shows that some perforation clusters have little production contribution. In this study, a three-dimensional (3D) numerical model for simulating the multiple fracture propagation based on 3D block discrete element method was established, and this model considers the stress interference, perforation friction and fluid-mechanical coupling effect. In order to determine the most appropriate measures to improve the uniformity of multiple fracture propagation, the effect of the geologic and engineering parameters on the multiple fracture propagation in shale reservoirs is investigated. The modeling results show that the geometry of each fracture within a stage is different, and the outer fractures generally receive more fracturing fluid than the interior fractures. The vertical stress almost has no effect on the geometries of multiple fractures. However, higher horizontal stress difference, larger cluster spacing, smaller perforation number, higher injection rate, and smaller fracturing fluid viscosity are conducive to promote the uniform propagation of multiple fractures. The existence of bedding planes will increase the fluid filtration, resulting in a reduction in fracture length. The middle two fractures receive less fluid and the width of them is smaller. Through analyzing the numerical results, a large amount of fracturing fluid should be injected and the proppant with smaller size is suggested to be used to effectively prop the bedding planes. Cluster spacing and perforation number should be controlled in an appropriate range according to reservoir properties. Increasing the injection rate and reducing the viscosity of fracturing fluid are important means to improve the geometry of each fracture

Lipoteichoic acid obtained from Lactobacillus paracasei via low-temperature pasteurization alleviates the macrophage inflammatory response by downregulating the NF-κB signaling pathway

This study compared the anti-inflammatory properties of Lactobacillus paracasei 6–1 lipoteichoic acid (LTA) obtained via different heat treatments to clarify the effect of heat intensity on its immunomodulatory activity. LTA exposed to low-temperature pasteurization (65 °C for 30 min) contained more acetylglucosamine and exhibited the strongest anti-inflammatory activity. It significantly down-regulated the pro-inflammatory cytokine levels (tumor necrosis factor-alpha (TNF-α), IL-1, IL-6, and IL-12) and increased that of the IL-10 anti-inflammatory cytokine (p < 0.05). LTA effectively improved cytokine imbalance in mice repaired the intestinal oxidative damage caused by enteritis, and regulated inflammation by downregulating MyD88, TLR4, p-ERK, NF-κB p65, and p-NF-κB p65 expression (p < 0.05) on the protein and transcript levels. In summary, low-temperature pasteurized LTA more effectively regulated the inflammatory response by downregulating the TLR4-MyD88-MAPK and NF-κB signaling pathways