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X-ray phase contrast imaging (PCI) based on synchrotron radiation was introduced for the first time as an in situ imaging way to investigate sea salt phase change, i.e. deliquescence and crystallization in atmospheric environment. A performance on the deliquescence of pure NaCl, which is the dominant component in sea salt, demonstrated that this technique can directly observe the change of core particle and differentiate the outer water layer clearly in solid-aqueous system of ~100 µm scale. The imaging results showed that sea salt particle deliquesced on a large scale of relative humidity (RH) between 34 and 97% RH as a solid-liquid drop, while no clear deliquescence RH was observed during the process. According to the drop size growth curve, sea salt deliquescence can be divided into three steps, namely water accumulating step (34-75% RH), bulk melting step (75-86% RH) and delay dissolving step (>86% RH), which are most probably dominated by grouped components as MgCl2/CaCl2/MgSO4, NaCl and Na2SO4/KCl/K2SO4, respectively. Instead at a sole RH, the crystallization of sea salt solution occurred at a range of 46-58% RH, which well agreed with the theory proposed by Ge et al. The aqueous-solid condition provided by sea salt deliquescence and crystallization may greatly enhance the heterogeneous chemical reactions in atmosphere. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The hippocampus, a major component of the brain, is one of the target nervous organs in lead poisoning. In this work, a rat’s hippocampal injury caused by lead was studied. The lead concentrations in blood, bone and hippocampus collected from rats subject to lead poisoning were quantified by Inductively Coupled Plasma Mass Spectrometry while morphological information and elemental distributions in the hippocampus were obtained with synchrotron radiation X-ray phase contrast imaging and synchrotron radiation micro-beam X-ray fluorescence, respectively. For comparison, identical characterization of the specimens from the rats in the control group was done in parallel. Results show that the ratios between the lead content in the treated group and that in the control group of the hippocampus, bone, and blood are about 2.66, 236, and 39.6, respectively. Analysis also revealed that some health elements such as S, K, Cl and P increase in the regions with high lead content in the treated hippocampus. Morphological differences between the normal and lead-exposed hippocampus specimens in some local areas were observed. Explicitly, the structure of the lead-exposed hippocampus was tortuous and irregular, and the density of the neurons in the Dentate Gyrus was significantly lower than that from the control group. The study shows that the synchrotron radiation methods are very powerful for investigating structural injury caused by heavy metals in the nervous system. [ABSTRACT FROM AUTHOR]

In order to explore the mechanism of moss as air pollution biomonitor, the moss samples were exposed in a pollution site of Shanghai Institute of Steel Research (SISR) and a control site of Shanghai Institute of Applied Physics (SIAP) simultaneously for one month. The concentrations of trace elements in the micro areas of leaf and stem, as well as in the whole moss tissue, were determined using synchrotron radiation X-ray fluorescence (SRXRF) method. The distributions of some metal elements such as Pb, Cu, Fe, Ni, Mn, Zn, Ca and K in the leaf surface and the stem slice were obtained. The results showed that the metallic ions were not evenly distributed after adsorption. In particular, some elements of K, Ni, Fe, Pb, etc., were concentrated in the leaf apex and the intermediate rib. Under pollution condition, the excessive Pb was adsorbed and deposited in the leaf. It caused serious damage to plant growth and ultrastructure, also suppressed moss' normal absorption to the nutritive elements of K, Ca, etc. [ABSTRACT FROM AUTHOR]

Abstract: Adverse health effects are associated with the inhalation of a variety of atmospheric particles. To study the lung injuries caused by aerosol PM2.5, synchrotron radiation (SR) X-ray phase-contrast imaging technique was used. Nude mice were inoculated with PM2.5 samples collected from suburban area (JD), industrial area (BS) and traffic tunnel (DPQ) of Shanghai. From X-ray phase-contrast images of lung tissues, apart from blood vessels and structures of alveoli, even hemorrhage spots of several microns caused by the inflammation were clearly observed. The studies showed that the PM2.5 samples collected from the traffic tunnel (DPQ) produced higher level of lung injury, followed by the aerosol samples collected from industrial area (BS) and suburban area (JD). Our studies also helped us to understand the process of lung injuries caused by aerosol particles. [Copyright &y& Elsevier]

Three human liver tissue samples (∼5 mm ⊗ 40 mm ⊗ 20 nun) were excised from a cancer patient's liver during surgery. The microradiology analysis was performed with a non-standard approach on a synchrotron. High-resolution refractive-index edge-enhanced microradiographs that cover a larger volume of the liver tissue sample were obtained. The cancer tissue and normal tissue could be clearly identified and distinguished based on their different textures. Furthermore, new blood vessel hyperplasia was found near the cancer area. Blood vessels with a diameter smaller than 20 μm could be identified. These findings were fully consistent with the histopathological examination of the same area. Microradiographs of the newly formed blood vessels at different angles were also obtained. This result shows that it is possible to further develop this approach into a technique of microradiographic imaging for clinic diagnosis of liver cancer at the early stage. [ABSTRACT FROM AUTHOR]

Focuses on a study which explored the distribution of inorganic substances in bone, and provided scientific basis for prevention and therapy of osteoporosis using the synchroton radiation X-ray fluorescence microprobe technique. Materials and methods; Results and discussion; Conclusions.

Abstract: PM2.5 samples were collected simultaneously at three representative areas (central city, industrial area and clean air suburban) of Shanghai city. Their morphologies and elemental compositions were determined by scanning electron microscopy coupled with energy analysis (SEM-EDX). The particles were classified into four groups based on morphology and elemental composition. Soot aggregates and spherical fly ash particles were the two dominant types and they were identified as originating from automobile exhaust, metallurgical industry and coal combustion. The size distribution of the particles showed that most had diameters in the range of 0.2–1.4 μm. Individual particles were measured by synchrotron radiation micro-beam X-ray fluorescence (micro-SXRF) and the micro-SXRF spectra were obtained. Pattern recognition techniques, which took the micro-SXRF spectrum of a single aerosol particle as its fingerprint, were used to identify the origins of the particles. Seven source types were identified. They were: metallurgical industry, vehicle exhaust, soil dust, coal combustion, diesel exhaust, oil combustion and motorcycle exhaust. Metallurgical industry, automobile exhaust, and coal combustion were recognized to be the main pollution sources of PM2.5 in the air of Shanghai city. [Copyright &y& Elsevier]