Search

To evaluate the potential effect of interaction between breastfeeding and environmental tobacco smoke ( ETS) exposure on respiratory health, we studied 31 049 children (aged 2-14 years) from 25 districts of seven cities in northeast China. Parents of the children completed standardized questionnaires that characterized the children's histories of respiratory symptoms and illness, feeding methods, ETS exposure, and other associated risk factors. Breastfeeding was defined as having been mainly breastfed for 3 months or more. The results showed that the association of ETS exposure with childhood respiratory conditions/diseases was modified by breastfeeding, and the association for nonbreastfed children was stronger than that for breastfed children. In particular, for nonbreastfed children, the odds ratios ( ORs) for the effect of current ETS exposure asthma was 1.71 (95% CI: 1.43-2.05); however, the OR for breastfed children was 1.33 (95% CI: 1.20-1.48), indicating that the interactions between breastfeeding and current ETS exposure on asthma were statistically significant ( P = 0.019). When stratified by school (kindergarten vs. elementary school), breastfeeding was more protective for asthma-related symptoms among children from kindergarten. In conclusion, this study shows that breastfeeding is associated with smaller associations between ETS exposure and respiratory conditions in children, suggesting that breastfeeding reduces susceptibility to the respiratory effects of ETS. [ABSTRACT FROM AUTHOR]

The photocurrent spectra of the inter-band photoinduced anomalous Hall effect (PAHE) in insulating GaAs/AlGaAs quantum wells have been observed at room temperature. The PAHE current changes linearly with the varied longitudinal electric fields. The anomalous Hall conductivity corresponding to excitonic state 1HH-1E (the first valence subband of heavy hole to the first conduction) has the same sign with that of excitonic state 1LH-1E (the first valence subband of light hole to the first conduction), while under uniaxial strain along the <110> axes, they have different signs. The PAHE current of 1HH-1E decreases linearly, but that of 1LH-1E increases linearly with shear strain. The linearly dependence of the PAHE current on uniaxial strain along the <110> axes suggests that the dominant mechanism is intrinsic, which has not yet been confirmed in our previous work [Yu et al., Appl. Phys. Lett. 100, 142109 (2012)]. [ABSTRACT FROM AUTHOR]

The (001)-oriented P-I-N InGaAs/GaAs quantum wells (QWs) are studied by means of helicity dependent spin photocurrent. We have observed an unexpected circular dichroism effect along [001] direction in the QWs without an applied magnetic field. The circular polarization rate can be linearly tuned by the applied DC current flowing along [001] direction, and its value is enhanced more than one order in an InGaAs/GaAs vertical-cavity surface-emitting laser with distributed Bragg reflectors than that in a common InGaAs/GaAs QWs. This experiment indicates a type of spin-splitting in (001)-grown P-I-N InGaAs/GaAs quantum wells induced by space inversion asymmetry introduced by residual strain which is previously overlooked. [ABSTRACT FROM AUTHOR]