[Repairing effects of Lactobacillus acidophilus on ceftriaxone-induced intestinal dysbacteriosis in mice].

OBJECTIVE: To investigate the repairing effect of Lactobacillus acidophilus LA11-Only on ceftriaxone induced intestinal micronbiota imbalance in mice and its alleviating effect on lipid metabolism. METHODS: A total of 30 SPF BALB/c male mice were randomly divided into control group(10) and model group(20). The model group was given ceftriaxone sodium solution by gavage for a week to create a mouse model of antibiotic flora disorder. The natural recovery group(10) was given 10% skimmed milk solution by gavage, and the LA11-Onlly group was given Lactobacillus acidophilus skimmed milk solution(1.0×10~9CFU/mL). Two weeks later, the feces were collected aseptically.16S rRNA sequencing technology and ultra-high-performance liquid chromatography combined with mass spectrometry(UPLC-MS) were used to analyze the repair effect of LA11-Onlly on antibiotic induced bacterial flora disorder and lipid metabolism in mice. RESULTS: After ceftriaxone treatment, the diversity of intestinal microbiota in mice decreased, and there was a significant difference in the composition of flora compared with the control group; After treatment with LA11-Onlly, the Alpha diversity increased, the abundance of beneficial bacteria such as Lactobacillus and Butyricicoccus increased, and the composition of flora was closer to the control group; At the same time, the concentration of short chain fatty acids(SCFAs) increased in varying degrees. Compared with the natural recovery group, the levels of butyric acid and valeric acid in LA11-Onlly group increased significantly, close to the same level as the control group. CONCLUSION: Lactobacillus acidophilus LA11-Onlly probiotics can inhibit the growth of harmful bacteria by regulating the diversity and community composition of intestinal microbiota, promote the increase of the concentration of SCFAs, and alleviate the damage of antibiotics to the body.

Dynamic Fluid in a Porous Transducer-Based Angular Accelerometer.

This paper presents a theoretical model of the dynamics of liquid flow in an angular accelerometer comprising a porous transducer in a circular tube of liquid. Wave speed and dynamic permeability of the transducer are considered to describe the relation between angular acceleration and the differential pressure on the transducer. The permeability and streaming potential coupling coefficient of the transducer are determined in the experiments, and special prototypes are utilized to validate the theoretical model in both the frequency and time domains. The model is applied to analyze the influence of structural parameters on the frequency response and the transient response of the fluidic system. It is shown that the radius of the circular tube and the wave speed affect the low frequency gain, as well as the bandwidth of the sensor. The hydrodynamic resistance of the transducer and the cross-section radius of the circular tube can be used to control the transient performance. The proposed model provides the basic techniques to achieve the optimization of the angular accelerometer together with the methodology to control the wave speed and the hydrodynamic resistance of the transducer.

Metals in wild fish from Gaotang Lake in the area of coal mining, China: assessment of the risk to human health.

Environmental pollution can cause metal accumulation in aquatic organisms, but information on metal bioaccumulation in wild fish from coal mining areas is limited. We investigated tissue-specific metal accumulation in six economically important fish species common to Gaotang Lake, China, located in a coal mining area. We also conducted an assessment of potential risks to human health from consumption of these fish. Mean concentrations of arsenic, cadmium, cobalt, copper, mercury, lead, and antimony in the muscle of six fish species were below the corresponding Chinese maximum allowable concentrations except chromium and generally comparable with levels in fish reported by other studies. Tissue distribution patterns suggested that chromium and mercury were easily transported to the muscle, but concentrations of the other six metals were higher in the liver and gills. The daily intake of each metal was estimated at 0.002-0.220 g/day/kg body weight, and the non-carcinogenic health risks associated with the consumption of the fish from Gaotang Lake were acceptable. The results suggest that metal bioaccumulation in wild fish is not high in this coal mining area.