Dynamical Interaction Between Information and Disease Spreading in Populations of Moving Agents

Considering dynamical disease spreading network consisting of moving individuals,a new double-layer network is constructed,one where the information dissemination process takes place and the other where the dynamics of disease spreading evolves.On the basis of Markov chains theory,a new model characterizing the coupled dynamics between information dissemination and disease spreading in populations of moving agents is established and corresponding state probability equations are formulated to describe the probability in each state of every node at each moment.Monte Carlo simulations are performed to characterize the interaction process between information and disease spreading and investigate factors that influence spreading dynamics.Simulation results show that the increasing of information transmission rate can reduce the scale of disease spreading in some degree.Shortening infection period and strengthening consciousness for self-protection by decreasing individual’s scope of activity both can effectively reduce the final refractory density for the disease but have less effect on the information dissemination.In addition,the increasing of vaccination rate or decreasing of long-range travel can also reduce the scale of disease spreading.

Study on the Relationship between Stromal Cell-Derived Factor-1 (SDF-1) and Gastric Cancer

Whether SDF-1 is related to the occurrence and development of gastric cancer, we collected gastric cancer tissues and corresponding non-cancerous gastric tissues from 52 patients with gastric cancer, and detected the expression of SDF-1 by real-time fluorescence quantitative polymerase chain reaction (RT-PCR) and immunohistochemistry. We also analyzed the relationship between the expression level and clinicopathological characteristics. In both cases SDF-1 gene and protein expression in gastric cancer tissues were significantly higher than in corresponding non-cancerous gastric tissues (both P 0.05, respectively). Also, there were no significant relations hip in gastric cancer tissues of Helicobacter pylori (HP)-positive patients and negative ones (P > 0.05). The result of the study showed that SDF-1 might play a significant role in the process of formation and development of gastric cancer as an oncogene, but could not be used as an index to judge prognosis and predict recurrence.

Content determination of saponins and HS-GC/MS analysis of volatile components in Chinese Shizhu Panax of different growth years

HPLC and headspace-gas chromatography-mass spectrometry(HS-GC-MS)were used to investigate the content of saponins and volatile components in Chinese Shizhu Panax of different growth years.82 components were isolated from Chinese Shizhu Panax,69 components of them were successfully identified.They mainly contained monoterpenes,alkanes and sesquiterpenoids,of which sesquiterpenoids were the main components.The results indicated that the content of saponins in Chinese Shizhu Panax of different growth years was dissimilar and diverse.The content of total saponins can be enriched when properly prolonging the growth years of Chinese Shizhu Panax.However,the content of ginsenosides can reach the level in the fifth year according to Chinese Pharmacopoeia.The volatile components in Chinese Shizhu Panax of different growth years also differ in content,type and proportion of compounds to a certain degree.

Stability and bifurcation analysis of a fractional-order single-gene regulatory model with delays under a novel PD^α control law

In this paper,we propose a novel fractional-order proportional-derivative(PD)strategy to achieve the control of bifurcation of a fractional-order gene regulatory model with delays.The stability theory of fractional differential equations proved that with delays,some explicit conditions for the local asymptotical stability and Hopf bifurcation are given for the controlled fractional-order genetic model.It is demonstrated that the fractional-order gene regulatory model becomes controllable by adjusting the control gain parameters.In addition,the effect of fractional-order parameter on the dynamical behaviors is shown.Finally,numerical simulations are carried out to testify the validity of the main results and the availability of the fractional-order PD controller.