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Erythritol, a natural sweetener, is widely used in the food, medicinal and chemical industries because of its advantages of low calorie, good stability and high food safety. Yarrowia lipolytica is widely used as an efficient fermentation strain for erythritol production. However, the current research on erythritol production by Yarrowia lipolytica concentrates on control of the fermentation process and metabolic pathway regulation and has bottlenecks in the yield of erythritol and the fermentation process. On this basis, this article reviews recent progress in research on erythritol production by Yarrowia lipolytica from three aspects: fermentation substrate utilization, fermentation process control and metabolic pathway modification by genetic engineering. This review is expected to provide a reference for breaking the bottlenecks in erythritol production by Yarrowia lipolytica.

As a phenotypically and phylogenetically diverse group, lactic acid bacteria are found in a variety of natural environments and play an important role in medicine, bioengineering, food fermentation and agriculture. Lactic acid bacteria have a long history of use in food and have been considered as suitable vehicles for the production and targeted delivery of health-promoting or therapeutic bioactive substances due to their safety and probiotic properties, and the operability of their genetic systems. This article summarizes the latest studies on lactic acid bacteria as delivery vehicles in vivo with a focus on gene expression systems of lactic acid bacteria, the expression forms of bioactive substances and the application of lactic acid bacteria as delivery vehicles in the treatment of various diseases. It is hoped that this review will provide a basis for subsequent research.

Previous studies have shown that Lactobacillus plantarum AR495 has good anti-inflammatory and anti-osteoporosis effects. In order to further explore the effect and mechanism of AR495 in alleviating osteoporosis (OA), a rat model of OA was established to investigate the effects of AR495 on OA markers, inflammatory factor levels and oxidative stress injury in OA rats and to verify the recovery of cartilage matrix and bone by pathological staining of joints and microtomography (micro-CT) imaging. The results showed that AR495 could significantly alleviate excessive body mass gain caused by decreased physical activity in OA rats (P < 0.05). Pathological analysis showed that AR495 could significantly reduce the level of tumor necrosis factor-α (TNF-α) in the joint tissue of OA rats, inhibit the production of matrix metalloproteinase-13 (MMP-13) and the production of C-telopeptide of type II collagen (CTX-II) as a degradation product of cartilage matrix, thereby alleviating the degradation of articular cartilage matrix in rats. Micro-CT imaging showed that AR495 could significantly alleviate bone loss in the joint of OA rats and effectively protect the integrity of cartilage and synovium of rats. In addition, AR495 could significantly increase the activity of superoxide dismutase (SOD) and reduce the concentration of malondialdehyde (MDA) in peripheral blood (P < 0.05). Quantitative real-time polymerase chain reaction (qPCR) analysis showed that AR495 could stimulate the expression of the mucin-2 (MUC-2) and occludin-1 genes in intestinal goblet cells and repair the intestinal barrier function. It can be seen that AR495 can alleviate OA inflammation level and create a beneficial internal environment for chondrocytes to exert their functions and produce collagen matrix, thereby alleviating and restoring joint injury and improving OA symptoms.

The nonlinear strain and stress expressions of suspension cable are established from the basic condition of suspension structure on the Lagrange coordinates and the equilibrium equation of the suspension structure is obtained. The dynamics equations of motion of the suspended cable with attached masses are proposed according to the virtual work principle. Using the spline function as interpolation functions of displacement and spatial position, the spline function method of dynamics equation of suspension cable is formed in which the stiffness matrix is expressed by spline function, and the solution method of stiffness matrix, matrix assembly method based on spline integral, is put forwards which can save cost time efficiency. The vibration frequency of the suspension cable is calculated with different attached masses, which provides theoretical basis for valuing of safety coefficient of the bearing cable of the cableway.

According to actual working condition, the catenary equations of elastic track tope for setting-up is proposed based on the cableway erection requirement, such as the erection angle of end, the initial cable length and midpoint position of cable. The mechanics equilibrium equations, the loads span equations and the consistent equations are presented by analysis of track rope stress state under loads. The nonlinear equations are constructed for elastic track tope with multiple loads and the initial values of newton iteration method are obtained to solve the nonlinear equations. The results of this method are compared with the testing results and numerical results in other literatures and the contrast verifies the reliability of this method. The method is more concise and has smaller amount of calculations with a unified form. It can provide effective means to design the cargo cableway and to check the engineering safety during the erection stage and running stage of cableway.