On epidemic spreading in metapopulation networks with time-varying contact patterns.

Considering that people may change their face-to-face communication patterns with others depending on the season, we propose an epidemic model that incorporates a time-varying contact rate on a metapopulation network and its second-neighbor network. To describe the time-varying contact mode, we utilize a switched system and define two forms of the basic reproduction number corresponding to two different restrictions. We provide the theoretical proof for the stability of the disease-free equilibrium and confirm periodic stability conditions using simulations. The simulation results reveal that as the period of the switched system lengthens, the amplitude of the final infected density increases; however, the peak infected density within a specific period remains relatively unchanged. Interestingly, as the basic reproduction number grows, the amplitude of the final infected density within a period gradually rises to its maximum and then declines. Moreover, the contact rate that occupies a longer duration within a single period has a more significant influence on epidemic spreading. As the values of different contact rates progressively increase, the recovery rate, natural birth rate, and natural death rate all decrease, leading to a larger final infection density.

A coupled awareness-epidemic model on a multi-layer time-varying network.

Social interactions have become more complicated and changeable under the influence of information technology revolution. We, thereby, propose a multi-layer activity-driven network with attractiveness considering the heterogeneity of activated individual edge numbers, which aims to explore the role of heterogeneous behaviors in the time-varying network. Specifically, three types of individual behaviors are introduced: (i) self-quarantine of infected individuals, (ii) safe social distancing between infected and susceptible individuals, and (iii) information spreading of aware individuals. Epidemic threshold is theoretically derived in terms of the microscopic Markov chain approach and the mean-field approach. The results demonstrate that performing self-quarantine and maintaining safe social distance can effectively raise the epidemic threshold and suppress the spread of diseases. Interestingly, individuals' activity and individuals' attractiveness have an equivalent effect on epidemic threshold under the same condition. In addition, a similar result can be obtained regardless of the activated individual edge numbers. The epidemic outbreak earlier in a situation of the stronger heterogeneity of activated individual edge numbers.

The impact of the global and local awareness diffusion on epidemic transmission considering the heterogeneity of individual influences.

In this paper, we propose a coupled awareness-epidemic spreading model considering the heterogeneity of individual influences, which aims to explore the interaction between awareness diffusion and epidemic transmission. The considered heterogeneities of individual influences are threefold: the heterogeneity of individual influences in the information layer, the heterogeneity of individual influences in the epidemic layer and the heterogeneity of individual behavioral responses to epidemics. In addition, the individuals' receptive preference for information and the impacts of individuals' perceived local awareness ratio and individuals' perceived epidemic severity on self-protective behavior are included. The epidemic threshold is theoretically established by the microscopic Markov chain approach and the mean-field approach. Results indicate that the critical local and global awareness ratios have two-stage effects on the epidemic threshold. Besides, either the heterogeneity of individual influences in the information layer or the strength of individuals' responses to epidemics can influence the epidemic threshold with a nonlinear way. However, the heterogeneity of individual influences in the epidemic layer has few effect on the epidemic threshold, but can affects the magnitude of the final infected density.

Study on an SIHRS Model of COVID-19 Pandemic With Impulse and Time Delay Under Media Coverage.

Media coverage plays an important role in prevention and control the spread of COVID-19 during the pandemic. In this paper, an SIHRS model of COVID-19 pandemic with impulse and time delay under media coverage is established. The positive and negative emotions of public are considered by the impact of confirmed cases and medical resources. In order to restrain the negative information of public, the factor of policies and regulations with impulse and time delay is introduced. Furthermore, the system model is simulated and verified by the reported data of COVID-19 pandemic in Wuhan. The main results are as follows: (1) When the implementation rate of the negative information generated by the confirmed cases gradually reduced to 0.4 times, the cumulative confirmed cases will be significantly reduced to about 37000, indicating that the popularization of pandemic related media information should be broad; (2) When the implementation rate affected by the amount of policies and regulations information gradually increases to 3 times, the cumulative confirmed cases will be significantly reduced to about 28000, indicating that the policies and regulations information should be continuously and incrementally reported; (3) When the inhibition rate of policies and regulation information on negative information gradually increases to 3 times, the cumulative confirmed cases will also be significantly reduced to about 27000 cases, indicating that the targeted policies and regulations information has a significant impact on inhibiting the corresponding negative emotions.

Zbtb7b suppresses aseptic inflammation by regulating m6A modification of IL6 mRNA.

Radiotherapy is a crucial approach for treating tumors. However, radiation-induced aseptic inflammation is a common complication. Radiation pneumonitis is the acute manifestation of radiation-induced lung disease, and interleukin 6 (IL-6) is a major proinflammatory cytokine involved in radiation-induced lung injury. Here we found that silencing Zinc finger and BTB domain-containing protein 7B (Zbtb7b) resulted in higher radiation-induced IL-6 production in THP1 cells and BEAS-2B lung bronchial epithelial cells. Mechanistically, Zbtb7b recruited RNA demethylase ALKBH5 to IL6 mRNA. Subsequentially, it demethylated N6-methyladenosine (m6A) modification of IL6 mRNA and inhibited its nuclear export. Thus, Zbtb2b epigenetically suppresses irradiation-induced IL-6 production in the lungs via inhibiting the m6A modification and nucleocytoplasmic transport of IL6 mRNA, serving as a new potential predictive marker and therapeutic target in radiation pneumonitis treatment.

Ergostane steroids from the ethanol extract of Dysoxylum mollissimum.

Three new ergostane steroids, 7α-acetoxyl-ergosta-5,24(28)-diene-3ß,4ß,20S-triol (1), 7α-acetoxyl-ergosta-5,24(28)-diene-3ß,4ß-diol (2), and 7α-acetoxyl-ergosta-5,24(28)-3ß-ol (3) were isolated from the ethanol extract of stem bark of Dysoxylum mollissimum BI. Structural elucidation of all the compounds was performed by spectral methods such as 1D and 2D (1H-1H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. All the isolated steroids were in vitro evaluated for their anti-inflammatory activity against COX-1 and COX-2. As a result, steroids 1-3 exhibited modest selective inhibition for COX-1 (>60%).

Monoterpenoid indole alkaloids from Alstonia mairei and their cytotoxicity.

Phytochemical investigation on the 70% ethanol extract of the leaves of Alstonia mairei resulted in the isolation of three new monoterpenoid indole alkaloids, alstomairines A-C (1-3), along with one known compound, alpneumine A (4). Structural elucidation of all the compounds was accomplished by spectral methods such as 1D and 2D NMR, IR, UV, and HRESIMS. The isolated compounds were tested in vitro for cytotoxic activities against four osteosarcoma cell lines. Consequently, alkaloids 2 and 3 exhibited cytotoxic activities for all tested tumor cell lines with IC50 values from 9.2 to 13.0 µM.

The co-evolution of networks and prisoner's dilemma game by considering sensitivity and visibility.

Strategies adopted by individuals in a social network significantly impact the network, and they strongly affect relationships between individuals in the network. Links between individuals also heavily influence their levels of cooperation. Taking into account the evolution of each individual's connection, we explore how sensitivity and visibility affect the prisoner's dilemma game. The so-called 'sensitivity' and 'visibility' respectively present one's self-protection consciousness and the ability of gaining information. We find that at moderate levels of player sensitivity cooperative behavior increases, but that at high levels it is inhibited. We also find that the heterogeneity of the weight of individuals at the end of the game is higher when sensitivity and visibility are increased, but that the successful-defection-payoff has less impact on the weight of individuals and on the relationship between the heterogeneity of the weight of individuals and the density of cooperators. This framework can be used to clarify the interaction mechanism between the micro-level of individual behavior and the macro-level of individual co-evolutionary processes.

How the initial level of visibility and limited resource affect the evolution of cooperation.

This work sheds important light on how the initial level of visibility and limited resource might affect the evolution of the players' strategies under different network structure. We perform the prisoner's dilemma game in the lattice network and the scale-free network, the simulation results indicate that the average density of death in lattice network decreases with the increases of the initial proportion of visibility. However, the contrary phenomenon is observed in the scale-free network. Further results reflect that the individuals' payoff in lattice network is significantly larger than the one in the scale-free network. In the lattice network, the visibility individuals could earn much more than the invisibility one. However, the difference is not apparent in the scale-free network. We also find that a high Successful-Defection-Payoff (SDB) and a rich natural environment have relatively larger deleterious cooperation effects. A high SDB is beneficial to raising the level of visibility in the heterogeneous network, however, that has adverse visibility consequences in homogeneous network. Our result reveals that players are more likely to cooperate voluntarily under homogeneous network structure.

An evolutionary vaccination game in the modified activity driven network by considering the closeness.

In this paper, we explore an evolutionary vaccination game in the modified activity driven network by considering the closeness. We set a closeness parameter p which is used to describe the way of connection between two individuals. The simulation results show that the closeness p may have an active role in weakening both the spreading of epidemic and the vaccination. Besides, when vaccination is not allowed, the final recovered density increases with the value of the ratio of the infection rate to the recovery rate λ / µ . However, when vaccination is allowed the final density of recovered individual first increases and then decreases with the value of λ / µ . Two variables are designed to identify the relation between the individuals' activities and their states. The results draw that both recovered and vaccinated frequency increase with the increase of the individuals' activities. Meanwhile, the immune fee has less impact on the individuals' vaccination than the closeness. While the λ / µ is in a certain range, with the increase of the value of λ / µ , the recovered frequency of the whole crowds reduces. Our results, therefore, reveal the fact that the best of intentions may lead to backfire.