Topological insulators on the square-hexagon lattice driven by next-nearest-neighbor hopping.

We investigate the topological phase transition of the square-hexagon lattice driven by the next-nearest-neighbor (NNN) hopping. By means of the Fukui-Hatsugai method, the topological invariantZ2can be determined. The phase diagrams in the (t1,t2) plane for different filling fractions are displayed, together with the size of the bulk band gap. We find the competition betweent1andt2can drive the system into topological nontrivial phase, withZ2= 1. Interestingly, for 2/5 and 3/5 filling fractions, topological nontrivial phase can be easily realized when the NNN hoppings are turned on. Besides, the phase diagrams in the plane oft2andλso2(t1andλso1) are also investigated. By numerically diagonalizing the Hamiltonian, the bulk band structures are calculated. And the topological trivial and nontrivial phase are also distinguished in terms of helical edge state. In experiments, these topological phase transitions may be realized by shaking optical lattice.

Tobacco point-of-purchase marketing in primary and middle school neighbourhoods in Tianjin / 中国学校卫生

Objective@#To understand the distribution of tobacco point-of-purchase(pop) activies 100 meters around the primary and middle school and the situation of selling cigarettes to students of Tianjin. To provide evidence for creating a smoke-free and healthy school environment.@*Methods@#With the method of simple random sampling, 195 schools were selected to investigate the tobacco retailers within 100 meters around the school, and the nearest tobacco retailers was observed.@*Results@#Totally 36.9 percent of the schools found tobacco retailers within 100 meters. There were 127 tobacco retailers, and no tobacco advertisements were found. The percentage of tobacco retailers within 100 meters of vocational schools, primary schools and middle schools was 33.3%, 34.1% and 40.4%, respectively. Among the 72 tobacco retailers observed, the proportion of tobacco retailers within 20, 21-50, and 51-100 meters from the school were 9.7%, 36.1% and 54.2%, respectively. The majority of tobacco retailers were grocery stores/convenience stores (55.6%), followed by alcohol and tobacco stores (34.7%). The proportion of tobacco selling points failing to set up the signs of "smoking harmful to health" and "not selling cigarettes to minors" were 81.9% and 86.1% respectively.@*Conclusion@#It’s concerning that the layout of tobacco retailers and the posting of signs, and the tobacco products for to minors in Tianjin. It is necessary to strengthen the surrounding environment renovation and publicity and law enforcement.

Anti-Trimeresurus albolabris venom IgY antibodies: preparation, purification and neutralization efficacy.

BACKGROUND: Snakebite incidence in southwestern China is mainly attributed to one of the several venomous snakes found in the country, the white-lipped green pit viper Trimeresurus albolabris. Since antivenom produced from horses may cause numerous clinical side effects, the present study was conducted aiming to develop an alternative antivenom antibody (immunoglobulin Y - IgY) from leghorn chickens. METHODS: IgY in egg yolk from white leghorn chicken previously injected with T. albolabris venom was extracted by water, precipitated by ammonium sulfate and purified by affinity chromatographic system. IgY was identified by SDS-PAGE, ELISA and Western blot, and its neutralizing assay was conducted on mice. RESULTS: Chickens injected multiple times with T. albolabris venom elicited strong antibody responses, and from their egg yolk IgY was isolated and purified, which exhibited a single protein band on SDS-PAGE and two bands (about 65 and 35 kDa, respectively) under reduced conditions. Immunoblot analysis revealed that these IgY are polyclonal antibodies since they bind with most venom components. In the neutralizing assay, all mice survived while the ratios of IgY/venom reached up to 3.79 (50.0 mg/13.2 mg). CONCLUSIONS: IgY antibody response was successfully conducted in white leghorn chicken injected with T. albolabris venom. IgY against T. albolabris venom was obtained for the first time, and it exhibited strong neutralizing potency on mice. These results may lay a foundation for the development of IgY antivenom with clinical applications in the future.

Anti-Trimeresurus albolabris venom IgY antibodies: preparation, purification and neutralization efficacy

Snakebite incidence in southwestern China is mainly attributed to one of the several venomous snakes found in the country, the white-lipped green pit viper Trimeresurus albolabris. Since antivenom produced from horses may cause numerous clinical side effects, the present study was conducted aiming to develop an alternative antivenom antibody (immunoglobulin Y - IgY) from leghorn chickens. Methods IgY in egg yolk from white leghorn chicken previously injected with T. albolabris venom was extracted by water, precipitated by ammonium sulfate and purified by affinity chromatographic system. IgY was identified by SDS-PAGE, ELISA and Western blot, and its neutralizing assay was conducted on mice. Results Chickens injected multiple times with T. albolabris venom elicited strong antibody responses, and from their egg yolk IgY was isolated and purified, which exhibited a single protein band on SDS-PAGE and two bands (about 65 and 35 kDa, respectively) under reduced conditions. Immunoblot analysis revealed that these IgY are polyclonal antibodies since they bind with most venom components. In the neutralizing assay, all mice survived while the ratios of IgY/venom reached up to 3.79 (50.0 mg/13.2 mg). Conclusions IgY antibody response was successfully conducted in white leghorn chicken injected with T. albolabrisvenom. IgY against T. albolabris venom was obtained for the first time, and it exhibited strong neutralizing potency on mice. These results may lay a foundation for the development of IgY antivenom with clinical applications in the future.

Anti-Trimeresurus albolabris venom IgY antibodies: preparation, purification and neutralization efficacy

Background Snakebite incidence in southwestern China is mainly attributed to one of the several venomous snakes found in the country, the white-lipped green pit viper Trimeresurus albolabris. Since antivenom produced from horses may cause numerous clinical side effects, the present study was conducted aiming to develop an alternative antivenom antibody (immunoglobulin Y - IgY) from leghorn chickens. Methods IgY in egg yolk from white leghorn chicken previously injected with T. albolabris venom was extracted by water, precipitated by ammonium sulfate and purified by affinity chromatographic system. IgY was identified by SDS-PAGE, ELISA and Western blot, and its neutralizing assay was conducted on mice. Results Chickens injected multiple times with T. albolabris venom elicited strong antibody responses, and from their egg yolk IgY was isolated and purified, which exhibited a single protein band on SDS-PAGE and two bands (about 65 and 35 kDa, respectively) under reduced conditions. Immunoblot analysis revealed that these IgY are polyclonal antibodies since they bind with most venom components. In the neutralizing assay, all mice survived while the ratios of IgY/venom reached up to 3.79 (50.0 mg/13.2 mg). Conclusions IgY antibody response was successfully conducted in white leghorn chicken injected with T. albolabrisvenom. IgY against T. albolabris venom was obtained for the first time, and it exhibited strong neutralizing potency on mice. These results may lay a foundation for the development of IgY antivenom with clinical applications in the future.(AU)