Photoacoustic tomography is a developing, promising,non-invasive imaging method in the medical clinic diagnosis. It is an ultrasound-mediated biophotonic imaging method based on the intrinsic optical absorption properties of tissue and ultrasonic detection, and combines the merits of both high contrast advantage of pure optical imaging and high resolution advantage of pure ultrasound imaging. Photoacoustic tomography can be performed by detecting photoacoustic waves instead of detecting photons. In photoacoustic tomography, imaging contrast is based primarily on the optical properties of biological tissues, and imaging resolution is based primarily on the ultrasonic waves. It can avoid the influence of optical scattering on imaging resolution in principle, and can provide tomography of tissues with high contrast and high spatial resolution at medium depths. Photoacoustic tomography can provide an effective approach to studying the structures, physiological properties, metabolisms, pathological properties of biological tissues. It has important potential clinical applications in the early non-invasive detection of cancers, structural and functional in vivo imaging. A brief introduction of photoacoustic imaging mechanisms is gives, and the imaging methods, the image reconstruction algorithm and the potential biomedical applications of photoacoustic tomography are reveiewed.

Objective: To evaluate the non-carcinogenic health risk of heavy metals (As, Cd, Cr, Cu, Mn, Pb and Zn) in residential indoor dust for young children around an e-waste dismantling area in South China. Methods: A village around an e-waste dismantling area in South China was selected as a research site in October 2016. Convenience sampling method was used to select 36 houses in the village and 36 dust samples were collected by vacuum cleaner. The concentrations of heavy metals (Cd, Cr, Cu, Mn, Pb and Zn) in each sample were determined and expressed by the average value. Non-carcinogenic health risk assessment was conducted using the US Environmental Protection Agency (EPA) Health Risk Assessment (HRA) model, the American Toxicology and Disease Registry (ATSDR) Target-organ Toxicity Dose (TTD) approach and the ATSDR Binary Weight-of-Evidence (BINWOE) model. Results: The mean ± SD of concentrations of As, Cd, Cr, Cu, Mn, Pb and Zn were (48.90±33.91), (5.95±3.89), (173.57±580.37), (412.71±1 190.00), (612.82±540.70), (297.41±293.22) and (1 052.81±1 156.48) mg/kg, respectively. The HI value of TTD (2.670) and BINWOE (2.933) were higher than the safety threshold of EPA recommended non-carcinogenic health risk. The HI value of TTD and BINWOE were 1.93 and 2.12 times higher than the HI value of HRA (1.386). Conclusion There was non-carcinogenic health risk of heavy metals (As, Cd, Cr, Cu, Mn, Pb and Zn) via residential indoor dust around the e-waste dismantling area for local children.

Objective: To identify the etiology and source of infection in a diarrhea outbreak in Yunnan in May 2017 and to provide the evidence for formulating prevention and control measures. Methods: Epidemiological investigation was carried out on the epidemic situation of diarrhea in the village of Lvchun County in Yunnan Province, the field sampling, laboratory testing and data analysis were also performed. Results: Among the 44 patients, 11 of the 13 samples were positive for rotavirus nucleic acid in group A, and the positive rate was 84.62%. The survey showed that the water supply pipe was damaged and polluted by human and livestock manure and domestic sewage. The trend of the damaged water pipe was basically the same as the case distribution, and the rainfall was significantly related to the number of the disease. Conclusions This event was an outbreak of diarrhea caused by group A rotavirus. The direct pollution of drinking water caused by rainfall may be the risk factor of this outbreak. The health management of rural drinking water should be strengthened and the health knowledge and education of preventing intestinal infectious diseases should be promoted.