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BACKGROUND: Vascular structure is an important basis for maintaining cervical spinal cord function. To evaluate the involvement of microvessels in cervical spinal cord injury and treatment, it is necessary to carry out a good three-dimensional visualization and accurate quantitative analysis of the normal cervical spinal cord microvascular structure, but there are few reports about it. OBJECTIVE: To investigate the three-dimensional visualization and quantitative analysis of normal cervical spinal cord microvascular structure in rats by barium sulfate perfusion combined with micro-CT scanning, and to lay a foundation for the later evaluation of the involvement degree of microvessels in cervical spinal cord injury and the measurement of therapeutic effect. METHODS: Five adult male SD rats weighing 280-320 g were included. All animal operation procedures were implemented in accordance with the relevant national guidelines for the use of laboratory animals, and were approved by the Animal Use Ethics Committee of Southern Medical University. After rats were deeply anesthetized, vascularization was performed with warm heparin normal saline, polyformaldehyde and barium sulfate perfusion through cardiac puncture. Cervical spinal cord tissue was taken and placed in micro-CT for scanning and three-dimensional reconstruction. Quantitative analysis of the ratio of microvascular volume to tissue volume, ratio of vascular surface area to tissue volume, number of blood vessels, diameter of blood vessels, separation degree of blood vessels, connectivity density, structural model index and the number, percentage and volume of microvessels with different diameters were quantitatively analyzed. RESULTS AND CONCLUSION:（1） After three-dimensional reconstruction and visualization, the microvascular structure in the cervical spinal cord was clearly visible, showing the anterior and posterior arteries of the cervical spinal cord as well as several branch arteries.（2） Quantitative analysis results of microvascular index showed that ratio of microvascular volume to tissue volume was 0.022±0.002; ratio of vascular surface area to tissue volume was（52.370±6.271） mm-1; number of blood vessels was（0.604±0.076） mm-1; diameter of blood vessels was（0.040±0.005） μm; separation degree of blood vessels was（1.762±0.255） μm; connectivity density was（2.661±0.757） mm-3; structural model index was（4.400±0.129）. The number, percentage and volume of microvessels in cervical spinal cord with different diameters were quantified successfully.（3） Barium sulfate perfusion combined with micro-CT scanning can achieve three-dimensional visualization and accurate quantitative analysis of normal cervical spinal cord microvascular structure in rats, laying a good foundation for the later evaluation of the involvement of microvessels during cervical spinal cord injury and the measurement of therapeutic eff ect. [ABSTRACT FROM AUTHOR]

Curling disease in long historical photos significantly affects the presentation of cultural heritage information. However, people lack attention to the formation process and microstructural changes of photo curling. In this article, a long historical photo (1912–1949 AD) collected by the Second Historical Archives of China was taken as the research object, and the formation process and cause of the curling were further explored. Firstly, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray energy disperse spectrometer (EDS), and other instruments were used to analyze the material composition of the long historical photo. It was found that the photographic paper was made of gelatin, barium sulfate, and plant fiber layers. Then, the effects of hygrothermal environments on curling and contraction in the gelatin layer and simulated photographic paper were explored. Meanwhile, the formation process and main influence factors of the curling were preliminarily revealed. The morphological analysis by SEM was carried out to identify the inner correlation between the microstructure and curling of photos. Finally, the possible formation cause of photo curling was analyzed. This study provides a scientific basis and experimental data for the preservation and restoration of long historical photos based on gelatin. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) contamination is easily generated during the mining and manufacturing of barium (Ba). In this study, concentrations of both Ba and Cd in rice, vegetables, pork, fish, drinking water, and soil samples from an active barite mining district were determined. Daily intakes of Ba and Cd, as well as corresponding health risks, were evaluated. The average total daily exposure doses of Cd were 0.0035 and 0.0012 mg/kg BW/day (geometric mean) in the mining zone (MZ) and the chemical plant zone (PZ), respectively. These values significantly exceed the provisional tolerable monthly intake (25 μg/kg BW/month, equal to 0.00083 mg/kg BW/day). Based on the daily exposure doses, vegetable consumption was the most significant Ba exposure route for residents, contributing around 66.1% of the total exposure. In contrast, rice consumption was the major Cd exposure pathway, accounting for about 85.6% of the total exposure. Although the geometric mean (0.17) and 95th percentile (P95, 0.75) of the total hazard quotient (HQ) for Ba were below the acceptable level (1), suggesting that there were no significant health effects caused by Ba exposure, Cd exposure was associated with significant health risks, with the geometric mean of the HQ (1.7) and the P95 (21) well above the acceptable limit (1), indicating the unacceptable non-carcinogenic risk of Cd exposure. In summary, high Cd exposure risk, rather than Ba, was observed for populations living in a large-scale active Ba mining area., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)