Bathymetry of a macro-pulsed chaotic laser based on a 520†nm laser diode subject to free space optical feedback.

We generate a macro-pulsed chaotic laser based on pulse-modulated laser diode subject to free space optical feedback, and demonstrate the performance of suppressing backscattering interference and jamming in turbid water. The macro-pulsed chaotic laser with a wavelength of 520 nm as a transmitter is used with a correlation-based lidar receiver to perform an underwater ranging. At the same power consumption, macro-pulsed lasers have higher peak power than in the continuous-wave form, enabling the former to detect longer ranging. The experimental results show that a chaotic macro-pulsed laser has excellent performance of suppressing the backscattering of water column and anti-noise interference compared with traditional pulse laser, especially by multiple accumulations about 10∼30 times, and target position can still be determined when SNR is -20 dB.

Materials for Neural Differentiation, Trans-Differentiation, and Modeling of Neurological Disease.

Neuron regeneration from pluripotent stem cells (PSCs) differentiation or somatic cells trans-differentiation is a promising approach for cell replacement in neurodegenerative diseases and provides a powerful tool for investigating neural development, modeling neurological diseases, and uncovering the mechanisms that underlie diseases. Advancing the materials that are applied in neural differentiation and trans-differentiation promotes the safety, efficiency, and efficacy of neuron regeneration. In the neural differentiation process, matrix materials, either natural or synthetic, not only provide a structural and biochemical support for the monolayer or three-dimensional (3D) cultured cells but also assist in cell adhesion and cell-to-cell communication. They play important roles in directing the differentiation of PSCs into neural cells and modeling neurological diseases. For the trans-differentiation of neural cells, several materials have been used to make the conversion feasible for future therapy. Here, the most current applications of materials for neural differentiation for PSCs, neuronal trans-differentiation, and neurological disease modeling is summarized and discussed.

Mediation of achievement goal orientation in the association between learning stress and sleep quality among middle school students / 中国学校卫生

Objective@#To explore the associations among achievement goal orientation, learning stress and sleep quality among middle school students.@*Methods@#A total of 5 781 students were recruited from 14 middle schools in Guangzhou by a stratified cluster random sampling method. These students were investigated with learning stressors (SSA), achievement goal orientation (ADG), and Pittsburgh Sleep Quality Index (PSQI).@*Results@#The mean score of four aspects of achievement goal orientation was as follows: performance approach (25.98±6.76), performance avoidance (15.52±4.12), mastery approach (25.87±6.77), mastery avoidance (15.19±4.12). The average score of learning stress and sleep quality was (149.53±42.46) and (6.45±2.86), respectively. Performance approach, mastery avoidance and performance avoidance positively associated with learning stress and sleep quality(r=0.12-0.53, P<0.01). Mastery approach was negatively correlated with learning stress and sleep quality (r=-0.14-0.22, P<0.01). Four types of achievement goal orientation both had a direct effect on sleep quality. Performance avoidance and mastery approach indirectly affected sleep quality through learning stress.@*Conclusion@#Achievement goal orientation of middle school students closely relates to learning stress and sleep quality; performance avoidance and mastery approach indirectly affects sleep quality through learning stress. Positive achievement goal orientation helps to reduce learning stress, which would lead to sleep quality improvement among middle school students.