Tunable chiroptical response of graphene achiral metamaterials in mid-infrared regime.

We numerically investigate a tunable and extrinsic chiroptical response of a graphene achiral metamaterial in mid-infrared regime. The achiral metamaterial is composed of cascaded metallic split ring apertures and complementary graphene rings patterned on a dielectric layer. The strong extrinsic chiroptical responses of the metamaterial are allowed at oblique incidence and the integrated graphene can dynamically modulate extrinsic chirality by changing its Fermi level. The spectra of the chiroptical responses will show a blue shift with increasing the Fermi level of the patterned graphene. The maximal values of circular dichroism in the reflection and transmission modes can reach 80% and 50%, respectively. The maximal values of polarization rotation angle in the reflection and transmission modes can reach 80° and 60°, respectively. This graphene-based metamaterial design paves a way for a myriad of important terahertz (THz) and mid-infrared applications, such as optical modulators, absorbers and polarizers.

Epidemiological characteristics of injury mortality in Guangdong Province, China, 2015.

BACKGROUND: As the fourth leading cause of death, injury is an important public health concern in Guangdong Province, China. The epidemiological characteristics of injury mortality is changing along with the social development. This study described the epidemiological characteristics of injury mortality in Guangdong Province by analyzing the death surveillance data in a few areas in Guangdong Province in 2015. METHODS: Using the mortality data from the Disease Surveillance Points (DSP) system, injury deaths were classified according to the International Classification of Disease-10th Revision (ICD-10). The data were stratified by areas (urban/rural), gender, age groups, injury types, and then overall and type-specific injury mortality rates were estimated for the whole Guangdong Province, China. RESULTS: We estimated that about 38,200 individuals died from injury in Guangdong Province in 2015, producing a mortality rate of 43.11/100,000. The overall age-standardized injury mortality in men was higher in rural areas compared with urban areas (41.29/100,000 versus 24.89/100,000). In terms of injury intent, unintentional injuries were the commonnest injury type, which accounted for 83.93% of the overall injury deaths, however, the deaths caused by suicide should not be ignored, which occupied 12.67% of the total injury deaths. In terms of injury cause type, falls, road-traffic accidents, suicide, drowning, and accidental poisoning were the top five leading types of injury deaths. CONCLUSIONS: In Guangdong Province, injury is an important cause of death. Road-traffic accidents, falls, suicide, drowning, and accidental poisoning should be the priorities of intervention. Moreover, in rural areas, the men were the most targeted subpopulation of the prevention activities.

[Investigation on the perception of risk level of heat wave and its related factors in Guangdong province].

OBJECTIVE: To investigate the risk perception of heat wave, and further explore its related factors in Guangdong province. METHODS: A total of 2183 adults were selected by a multi-stage sampling method in Guangdong province. Each subject was interviewed in their home with a structured questionnaire by a well trained investigator from September to November, 2010. The questionnaire contained socio-demographic characteristics, heat wave related knowledge, risk perception of heat wave, etc. Chi-square test and multivariate logistic regression were employed in this study. RESULTS: The average age of total 2183 participants was (39.31 ± 14.16) years, among which 53.37% (1165/2183) were males, and 48.74% (1064/2183) were selected from urban. About 38.11% (832/2183) of participants heard about heat wave, and 38.52% (841/2183) of subjects thought the heat wave had higher impact on their health (risk perception score of heat wave ≥ 5 points). About 81.91% (1788/2183) of all participants thought the weather in most recent years was hotter than several years ago. Among these people, 30.48% (545/1788) thought the main reason of weather becoming hotter was due to emission of carbon dioxide, and 26.51% (474/1788) thought it was due to air pollution. Results from the multivariate logistic regression showed that the risk perception score of heat wave were higher in subjects with higher education (OR = 2.16, 95%CI: 1.41 - 3.30), from urban(OR = 1.37, 95%CI: 1.10 - 1.72), with higher score of trust(OR = 1.08, 95%CI: 1.01 - 1.14) and participants with higher score of heat wave related knowledge (OR = 1.39, 95%CI: 1.27 - 1.52). Furthermore, compared to hierarchist, egalitarian (OR = 1.73, 95%CI: 1.30 - 2.29), individualist (OR = 1.93, 95%CI: 1.41 - 2.65) and fatalist (OR = 1.80, 95%CI: 1.41 - 2.29) also had higher risk perception score of heat wave. CONCLUSION: There is a lack of knowledge and risk perception to heat wave among the residents in Guangdong province. Risk perception of heat wave was higher in people who were from urban, had higher level of trust on government, experts and media, had higher health-related knowledge score, and non-hierarchists.