[en] From optical absorption spectra and using the Judd-Ofelt theory, the phenomenological parameters, Ω₂, Ω₄ and Ω₆ of Er(DBM)₃Phen containing methyl methacrylate (MMA) solution and solid poly(methyl methacrylate) (PMMA) matrix were obtained. The polymer chains in the sold matrix showed a significant influence on the hypersensitive transition ⁴I_15/2→²H_11/2. The calculated radiative lifetime and stimulated emission cross section of ⁴I_13/2→⁴I_15/2 transition revealed that it is promising for Er(DBM)₃Phen containing PMMA to be used in rare earth containing polymer-based optical devices

[en] Objective: To investigate the configuration and management of personal protective device in X-ray imaging diagnosis and put for ward the normative requirements. Methods: Field inspection and document check and personal interviews were conducted in 545 selected medical institutions in six districts in Shanghai to investigate the configuration and management of personal protective device in X-ray imaging diagnosis rooms. Results: The configure rate of personal protective device is 99.8%. The configure rate of protective cap is the highest among the personal protective devices (76.9%), and then the protective collar 64.8%) and protective gonad apron (60.5%). 97% of the protective devices are made in China. The service life of 52.7% of protective devices is 5 years or low. The most common lead equivalent of protective devices is 0.35 mm Pb, which accounted for 80.1% of protective devices, and the lead equivalent of 28.4% of the protective gonad apron reaches 0.5 mm Pb, and the lead equivalent of 44.0% of the adjustable protective frames reaches 0.5 mm P6; 46 6% of the institutes clean the protective devices regularly and 39.6% of the institutes disinfect the protective products regularly. 71.7% of the institutes suspend or tile the protective devices. Conclusion: The configure rate of personal protective device is high, but lack of rational allocation. Management needs to be improved when it comes to specific equipping and managing. (authors)

[en] Objective: To investigate the occupational radiation protection status and influencing factors. Methods: A total of 94 interventional radiation workers in a tertiary hospital in Shanghai were enrolled by using a self-administered questionnaire survey, and the survey data included information on workload, the use of personal protective equipment and auxiliary protective equipment, personal dose monitoring, occupational health examination, factors affecting the use of personal protective equipment. Results: In 2017, the workload of cardiovascular, tumor and neurological interventional procedures were relatively large. The use rate of lead apron was 100%, followed by lead collar 97%, while the utilization rates of lead protective glasses, lead rubber caps and lead rubber gloves were only 52%, 23%, 10% and 3%, respectively. The usage rate of ceiling-suspension shields, table-suspension shields and mobile lead barriers were 84%, 62% and 69%, respectively. The wearing rate of personal dosimeter was 78%, the number of staff wearing personal dosimeters inside and outside the lead clothing accounted for 49%. The rate of regular occupational health examination was 100%. The comprehensive utilization rate of personal protective equipment and auxiliary protective equipment and the wearing rate of personal dosimeter in tumor interventional workers were the highest. Unbalanced configuration of protective equipment and different awareness of protection were the main reasons for the difference in the use rate of personal protective equipment among different interventional radiologists. Conclusion: The hospital should strengthen the construction of radiation safety culture, and further popularize the use of lead apron and auxiliary protective equipment. (authors)

[en] Objective: To develop the monitoring information system of radiodiagnosis and radiotherapy equipment in order to control the risk of radiodiagnosis and radiotherapy. Methods: This paper introduces the framework of the monitoring information system of radiodiagnosis and radiotherapy equipment in medical institutions from the aspects of construction target, user object, information source and function. The modules and related contents of information system are described in detail. The characteristics and advantages of the system are analyzed. The importance and feasibility of system development are discussed. Results: The system is aimed at many users, such as medical institutions, technical institutions and regulatory departments. Based on radiodiagnosis and radiotherapy equipment basic information, location information, testing and maintenance information, analysis the risk of radiodiagnosis and radiotherapy are analyzed to help medical institutions and regulatory departments to strengthen supervision. Conclusion: It is necessary and feasible to develop monitoring information system of radiodiagnosis and radiotherapy equipment. (authors)

[en] X-ray projection mammography, using a film/screen combination, or digital techniques, has proven to be the most effective imaging modality currently available for early detection of breast cancer. However, the inherent superimposition of structures makes a small carcinoma (a few millimeters in size) difficult to detect when it is occult or in dense breasts, leading to a high false-positive biopsy rate. Cone-beam x-ray-projection-based volume imaging using flat panel detectors (FPDs) may allow obtaining three-dimensional breast images, resulting in more accurate diagnosis of structures and patterns of lesions while eliminating the hard compression of breasts. This article presents a novel cone-beam volume computed tomographic breast imaging (CBVCTBI) technique based on the above techniques. Through a variety of computer simulations, the key issues of the system and imaging techniques were addressed, including the x-ray imaging geometry and corresponding reconstruction algorithms, x-ray characteristics of breast tissue and lesions, x-ray setting techniques, the absorbed dose estimation, and the quantitative effect of x-ray scattering on image quality. The preliminary simulation results support the proposed CVBCTBI modality for breast imaging in respect to its feasibility and practicability. The absorbed dose level is comparable to that of current mammography and will not be a prominent problem for this imaging technique. Compared to conventional mammography, the proposed imaging technique with isotropic spatial resolution will potentially provide significantly better low-contrast detectability of breast tumors and more accurate location of breast lesions

[en] Objective: To identify the cell death type and investigate the potential mechanism of ionizing radiation-induced neural cell death in the neonatal rat cerebral cortex. Methods: The neonatal Wistar rats were given a single dose of 2.0 Gy γ-irradiation. The cell death type and characterization in cerebral cortex were identified using DNA electrophoresis, TUNEL and HE staining. The P53- and iNOS-positive cells were analyzed quantitatively using imnmnohistochemistry. Results: The DNA and morphological characterization of death cells indicated that 2.0 Gy γ-irradiation induced apoptosis of the neural cells in neonatal rat cerebral cortex. The apoptosis indices in different cortex regions were significantly increased 4 h after irradiation, and reached the peak value at 12 h post-irradiation. The apoptosis index of neocortex was much higher than that of hippocampus (archicortex) and paleocortex, while paleocortex had lower apoptosis index than hippocampus. The quantitative immunohistochemistry suggested that the numbers of P53 and iNOS-positive cells were not different between these three cortex regions at the same time-point after irradiation. Conclusion: 2.0 Gy γ-rays induced apoptosis of the neural cells in neonatal rat cerebral cortex. The response of cells to the damage effects of ionizing radiation was similar in different cortex regions; however, the apoptosis indices were different significantly. These findings imply that the developing phase or type of neural cells may play a pivotal role in the apoptosis process induced by ionizing radiation. (authors)

[en] Highlights: • Four ILs ([C₈mim]NO₃, [C₈mim]Cl, [C₈mpy]Cl and [C₈mpy]Br) were not easily degraded. • Types of cations and anions would affect the toxicity of ILs to P. tricornutum. • The photosynthesis of P. tricornutum was inhibited by the four ILs. • Contents of protein and MDA changed remarkably when the diatom was exposed to ILs. • Significant changes in SOD and CAT activities occurred under the exposure of ILs. -- Abstract: With the increasing applications in various industrial areas, toxicity of ionic liquids (ILs) has gained much attention in recent years. In this work, 1-octyl-3-methylimidazolium nitrate ([C₈mim]NO₃), 1-octyl-3-methylimidazolium chloride ([C₈mim]Cl), N-octyl-3-metylpyridinium chloride ([C₈mpy]Cl) and N-octyl-3-metylpyridinium bromide ([C₈mpy]Br) were used to investigate the impacts of different types of cations and anions on their toxicity to a marine diatom Phaeodactylum tricornutum. Results showed that the four ILs had poor degradability under the culture conditions used in this study, and significantly inhibited the growth of this diatom with 96-h EC₅₀ values of 24.0, 33.6, 16.1 and 14.4 mg L⁻¹ for [C₈mim]NO₃, [C₈mim]Cl, [C₈mpy]Cl and [C₈mpy]Br, respectively. The data indicated that types of cations and anions would affect the toxicity of ILs to this diatom. Additionally, photosynthesis of this diatom was inhibited because significant decrease of chlorophyll a content and damage of PSII reaction centers were observed when it was exposed to the four ILs. Remarkable physiological and biochemical responses occurred in the cells of this diatom to alleviate the damaging effects of the four ILs. For example, content of soluble protein and activities of superoxide dismutase (SOD) and catalase (CAT) in the cells of this diatom increased significantly to form a protective mechanism against the toxicity of ILs, although they decreased in the cultures with high concentrations of ILs (≥20 mg L⁻¹). Thus, these results would not only provide strong evidences for evaluating the ecological risks and toxicity of ILs to marine ecosystem, but also help for understanding their toxic mechanisms to marine diatoms.

[en] Objective: To study the level of ionizing radiation and the protective effects after taking intervention measures for the X-ray bedside radiography, and to provide the basis for further development of management standards. Methods: A total of 15 bedside radiography sites from 12 medical institutions were randomly selected from the 9 districts in Shanghai. By simulating their daily working conditions, the dose equivalent rates at the observation points were monitored and evaluated. Results: The dose equivalent rates around the bedside were all higher than the background in this study. Even at the similar exposure conditions, the dose rate largely varied with the device. The range of the dose rate varied from 3.9 μSv/h to 5800 μSv/h without any protective screens, while the range was only from 0.095 μSv/h to 22.1 μSv/h with the use of protective screens. The higher the lead equivalent of the screen, the better the protective effect. Conclusion: Different bedside X-ray equipment have different self-protective performance, which leads to the difference of radiation level in the workplace. Purchasing equipment with good protective performance, using carefully and doing well in maintenance are the important guarantees to reduce the radiation dose. The adjacent patients, medical staff and visitors are recommended to be evacuated when performing the bedside X-ray photography. For those who can not be evacuated, it is suggested to use a convenient and practical and mobile protective screen. (authors)

[en] Highlights: • A joint of the BMG to copper alloy with aluminum alloy as transition layers is achieved. • After the bonding process the hardness of the BMG is enhanced. • The bending strength of the joint is decreased compared with the as-received BMG. • The multilayer joint has unique loading and deformation mode. - Abstract: In this work we demonstrate the diffusion bonding of Zr₅₅Cu₃₀Ni₅Al₁₀ bulk metallic glass (BMG) to aluminum and copper alloy. The process parameters including temperature, pressure and time are investigated experimentally, and we obtain appropriate ones for accomplishing diffusion bonding of the BMG to aluminum alloy successfully. Then we present a two-step diffusion bonding process to bond the BMG to copper alloy by using aluminum alloy as transition layers, and achieve a five-layer bonded joint of BMG/Al/Cu/Al/BMG. The mechanical properties of the multilayer joint are examined. The hardness of the BMG in the joint is enhanced while the bending strength decreases significantly compared with the as-received BMG. Besides, the crystalline metals alleviate and block the extension of cracks in the BMG, which results in the joint fracturing in an explosion-proof glass manner, dissimilar to rupturing in a catastrophic manner that is always happened in the BMGs. Therefore, diffusion bonding of BMG to crystalline metals is a promising way to extend its application.

[en] Background: Anyang Zhangdeng site is a Pre-Shang site by the unearthed stone artifact mainly and the age is equivalent to the late Erlitou culture, and it is about 200 km away from the Erlitou. Currently the trace element analysis of ancient animal skeletons' samples has rarely been seen. Purpose: This paper attempts to study the Zhangdeng animal's diet and the heavy metal exposure. The paleoenvironmental information is indicated by the former using a new method. Methods: Eight samples (enamel and dentin samples from 4 animals individuals) are tested using the synchrotron radiation X-ray fluorescence (SR-XRF) technique. Results: Fe and Mn contents of ZY9507 were very high and Sr and Zn contents of ZY9505 and ZY9506 were similar, Sr and Zn contents of ZY9508 were higher than the formers and the contents of Cu and As were also obviously higher: Conclusions: Based on the above results: the samples of ZY9507 had undergone diagenetic pollution and wasn't suitable for the paleoenvironmental 'fingerprint'. ZY9505 and ZY9506 had the similar feeding habits and mainly ate the foods with lower Sr contents such as leaves class. Meanwhile, its lower accumulation of heavy metals shows the lower metal contents in Zhangdeng's paleoenvironment. ZY9508 may be an omnivorous animal and mainly ate the foods with higher Sr such as the grass, while its foods contained relatively high animal protein. Moreover, its levels of Cu and As suggested that it may belong to the 'exotic' animal and likely came from the Erlitou site which was the center of bronze casting. Overall, ethnic groups living Zhangdeng had the economic exchanges with the dominators of Erlitou, but the surrounding environment of the former was less affected by Erlitou bronze production activities on the whole. (authors)