A novel type of spiral wave with trapped ions

Pattern formation in ultra-cold quantum systems has recently received a great deal of attention.In this work, we investigate a two-dimensional model system accounting for the dynamics of trapped ions. We find a novel spiral wave which is rigidly rotating but with a peculiar core region in which adjacent ions oscillate in anti-phase. The formation of this novel spiral wave is ascribed to the novel excitability reported by Lee and Cross. The breakup of the novel spiral wave is probed and, especially, one extraordinary scenario of the disappearance of spiral wave caused by spontaneous expansion of the anti-phased core is unveiled.Comment: 4 pages,4 figure

Experimental Investigation into the Effect of Pyrolysis on Chemical Forms of Heavy Metals in Sewage Sludge Biochar (SSB), with Brief Ecological Risk Assessment

publishedVersio

Fluoroquinolone Resistance in <i>Salmonella</i>: Mechanisms, Fitness, and Virulence

Fluoroquinolones are highly effective broad-spectrum antibiotics usually used for the treatment of human and animal infections, including salmonellosis. Fluoroquinolones act against Salmonella by inhibiting their DNA replication. However, several zoonotic serotypes of Salmonella have developed resistance or are less susceptible to fluoroquinolones. Salmonella presents its resistance by substituting amino acids within the topoisomerase subunits, overexpression of multidrug efflux pumps, or decreasing the expression of outer membrane porins. The resistance level is further increased with the plasmid-mediated quinolone resistance genes which could horizontally transfer the resistance from strain to strain. The development of resistance in Salmonella shows that it is a multifactorial process and the acquisition of fluoroquinolone resistance might have significant influences on the bacterial fitness and virulence. Due to the high level resistance against fluoroquinolones that has been observed in Salmonella, care needs to be taken to avoid misuse and overuse of this important class of antibiotics to minimize the occurrence and dissemination of resistance

The model of rat lipid metabolism disorder induced by chronic stress accompanying high-fat-diet

<p>Abstract Objective</p> <p>To develop an animal model of Lipid Metabolism Disorder, which conforms to human clinical characteristic. Methods: There were 24 male Wistar rats that were randomly divided into 3 groups with 8 rats in each. They were group A (normal diet), group B (high-fat-diet), group C (chronic stress+ high-fat-diet). Group A was fed with normal diet, while group B and C were fed with high-fat-diet, going on for 55 days. From the 35th day, group B and C received one time of daily chronic stress, going on for 21 days. After that, the activities of the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and the levels of the serum triglyceride (TG), Cholesterol (Ch), high-density lipoprotein-Cholesterol (HDL-C) and liver TG were evaluated. Results: Compared with group A, the activities of the serum ALT and AST, and the levels of the serum CH, TG, HDL-C and liver TG were found to be markedly increased, when the level of HDL-C was markedly decreased in group B and C, and the results of group C was more obviously. Conclusion: Chronic stress and high-fat-diet have the synergistic action in rat's Lipid Metabolism Disorder. They lead to a model of Lipid Metabolism Disorder, which conforms to human clinical characteristic much better.</p

Fluoroquinolone Resistance in <i>Salmonella</i>: Mechanisms, Fitness, and Virulence

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Research of influence and mechanism of combining exercise with diet control on a model of lipid metabolism rat induced by high fat diet

OBJECTIVE: To investigate the influence and mechanism of combining exercise with diet control on a model of lipid metabolism rat induced by high fat diet. METHODS: Twenty-four male Wistar rats were randomly divided into 3 groups of 8: normal, model and intervention. The model group and intervention group were fed with high fat diet, while the normal group received basal feed. From day 1, the intervention group was randomly given interventions such as swimming exercise and dietary restriction. The interventions duration were 28 days. At the end of the experiment, the levels of rats’ body weight and liver weight were detected, the serum levels of total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) and hepatic triglyceride content (TG) were detected by using biochemical assay, serum level of gastrin (GAS), motilin (MTL) were assayed by the enzyme linked immunosorbent assay (ELISA). RESULTS: Compared with the level of body weight and liver weight in the normal rats, body weight and liver weight in the rat of the model group were significantly increase (P<0.05 or P<0.01). Plasma concentrations of TC, LDL-C and hepatic TG in the model group were significantly increased compared with those in the normal group (P<0.05 or P<0.01). The contents of GAS, MTL, HDL-C in the model rats’plasma were significantly reduced compared with those of the normal group (P<0.05 or P<0.01). Compared with those in the model group, rats’ body weight, liver weight, serum TC, LDL-C, and TG content of liver in the intervention group decreased significantly (P<0.05 or P<0.01). Meanwhile, serum content of GAS, MTL, HDL-C were significantly improved in the intervention rats compared to the model group. CONCLUSION: The action of combining exercise with diet control for lipid metabolism disorder might be related to regulation of GAS, MTL and other gastrointestinal hormones

Persistence and Nonpersistence of a Predator Prey System with Stochastic Perturbation

We analyze a predator prey model with stochastic perturbation. First, we show that this system has a unique positive solution. Then, we deduce conditions that the system is persistent in time average. Furthermore, we show the conditions that there is a stationary distribution of the system which implies that the system is permanent. After that, conditions for the system going extinct in probability are established. At last, numerical simulations are carried out to support our results