Objective:To study the scavenging activity of macroporous resin isolate of gynostemma pentaphyllum on free radical DPPH. Methods:The extract of gynostemma pentaphyllum via water boiling and precipitation with ethanol was separated by macro-porous resin respectively eluted by water, 40% ethanol and 80% ethanol to obtain the corresponding isolates. The antioxidant activity of the three isolates was determined by free radical DPPH systematic method, and the results were compared with that of gallic acid and ascorbic acid. Results: The 50% inhibitory concentration on free radical DPPH of the three isolates was 0. 081 2, 0. 028 7 and 0. 541 0 g·L-1 ,respectively. The 40% ethanol isolate had the highest saponins concentration. Conclusion:The macroporous resin i-solate with different solvent all shows antioxidant activity and the 40% ethanol isolate has the strongest effect, suggesting saponins may be the active substances for the lipid-lowering, hypoglycemic and free radical scavenging activities.

To study factors related to visual field damage in Possner- Schlossman Syndrome(PSS) .Methods 145 cases of PSS and 166 cases of promary open angle glaucoma(POAG)were followed up with tonometer and perimeter. Results①Prevalence of visual field damageamong PSS and POAG cases were 35.43% and 93.42% respectively;72.11% of the visual field damage in the PSS group was of early stage,while 78.92% of that in the POAG group was of middle or late stage.②Compared with PSS cases with no visual field damage,the damaged cases were older;their course of the disease was longer;the average IOP between crises was higher;more cases were involved binocularly;more cases demonstrated abnormal diurnal and nocturnal IOP varianle or no crossover phenomenon. ③Systematic examination was given to 26 PSS cases with visual field damage and among them, 11 cases were confirmed to be complicated with POAG. Conclusion①Although the incidence of visual field damage done by PSS is much smaller and the symptoms slighter than those done by POAG,the prognosis of PSS is by no means optimistic. ②Coses at more advanced age, with longer course, with higher IOP between crises, with binocular involvement or without IOP crossover phenomenon are at a higher risk of visual field damage. ③Serious damage can be done by PSS itself.

Objective To evaluate the radiation protection of occupational hazards in a hospital Clinac 23EX medical electronic accelerator construction project so as to ensure the health and safety of the relevant people involved.Methods According to the relevant laws,regulations and standards of China,combined with the relevant materials provided by the construction unit,the radiation protection tests and comprehensive assessment of this project were carried out.Results The performance test results of the medical electron accelerator met the requinements of GB/T 19046-2013 The ambient dose equivalent rate in the workplace was between the background dose rate (0.10 μ,Sv/h) and 11.5 μSv/h,which suggested the computer room shielding met the requirements of radiation protection.The total body effective dose,the for 7 radiation workers were 0.85,1.19,1.64 mSv,respectively,which were lower than the dose management control values of the construction unit and the national standards.Radiation protection supplies and the management system of the construction unit met the national requirements.Conclusions The construction project can effectively control the radioactive occupational hazard factors in normal operation,and the radiation protection facilities have reached the completion requirements.

Objective To evaluate the current status of radioactive occupational hazards in the construction of some medical institutions in Tianjin, discover existingproblems and deficiencies, and provide a technical basis for radiation protection management. Methods Based on the requirements of relevant regulations and standards, we comprehensivelyevaluated the results of the pre-evaluation and control effect evaluation of 81 radioactive occupational hazards in Tianjin. Results Among the 35 proposed protective measures for pre-evaluation of radiation occupational hazards constructionprojects, the lowest compliance rate is warning signs and personal protective equipment. Among the 46 construction projects of radioactive occupational hazard control evaluation, the pass rate of protective measures was between 73.9% and 100%, with the lowest pass rate for personal protective equipment. Besides, the pass rate of radiation protectionmanagement evaluation was 95.7% ～ 100%, with the lowest pass rate for the protection management system.The initial inspectionpass rateof the equipment quality control acceptancewas 98.6%, while the pass rate was 97.1% for the relevant workplace radiation protection during the initial inspection. Conclusion The pre-evaluation completion rate of radiological occupational hazard evaluation in Tianjin medical institution construction project, unilateral and area of construction room, workplace layout and zoning, ventilation, shielding measures, personal dose management and occupational health inspection all meet the requirements of regulations and standards. However, there are still some deficiencies in the personal protective equipment, warning signs and the radiation protection management system. Therefore, the regulatory department should further strengthen the evaluation of medical institutions, especially the key supervision and management of non-conformities.

Objective　 : To evaluate the implementation, application, and problems and suggestions of the Radiation Shield- ing Requirements in Room of Radiotherapy Installations—Part 1: General Principle (GBZ/T 201.1—2007) through a survey of relevant personnel in radiation health technical service institutions, and to provide a scientific basis for further revision and implementation of this standard. Methods: A questionnaire survey was conducted among randomly selected per- sonnel in radiation health technical services across China, which mainly investigated the awareness, training, application, and revision suggestions related to the GBZ/T 201.1—2007. The results were aggregated and analyzed. Results: A total of 184 evaluation questionnaires on the GBZ/T 201.1—2007 were collected from technical service staff in 25 provinces. Among the responders, 64.1% thought that the standard had been widely applied; 91.8% thought that the standard could meet work needs; only 54.3% ever received relevant training on the standard; 68.5% used the standard once or more per year; 33.7% thought that the standard needed to be revised. Conclusion The personnel in radiation health technical services have a high awareness rate of the GBZ/T 201.1—2007 and its contents, but their familiarity with and application of the standard need to be improved. Relevant departments should strengthen the training and promotion of the standard, and part of the standard should be revised.

Objective To preliminarily compare ⁶LiF-⁷LiF and CR39 in individual neutron dose monitoring, and to provide a reference for improving individual neutron dose monitoring. Methods According to the GBZ 128-2019, 26 radiation workers from 7 institutions received individual neutron dose monitoring with ⁶LiF-⁷LiF and CR39 at the same time. The monitoring results were analyzed. Results For most of the workers, the personal neutron dose equivalent H_p(10) was less than the minimum detectable level. The results with the two monitoring methods differed in 6 of 26 workers. Conclusion Both ⁶LiF-⁷LiF and CR39 monitoring methods can be used for individual neutron dose monitoring for radiation workers, but the difference between ⁶LiF-⁷LiF and CR39 (in threshold energy, energy response, etc.) should be considered so that different types of radiation workers receive appropriate individual neutron dose monitoring.

Objective To analyze the process of intercomparison of national personal dose monitoring, evaluate the ability of personal dose monitoring, and ensure the accuracy and reliability of monitoring results in our laboratory. Methods In accordance with the intercomparison protocol for 2019—2021, an energy-discriminant thermoluminescence dosimeter was used for measurement at different doses. The uncertainty of measurement was evaluated and compared with the reference value. Results H_p(10) was measured for intercomparison in 2019—2021. In 2019, the single group performance difference was −0.02 to 0.02 and the comprehensive performance was 0.02. These values were 0.02-0.10 and 0.05 in 2020, and −0.02 to 0.02 and 0.01 in 2021. The intercomparison results were rated as excellent in the three consecutive years. Conclusion The personal dose monitoring system in our laboratory was in good condition, and the monitoring results were accurate and reliable. Improving the knowledge of personnel and cultivating a serious working attitude are important for intercomparison and personal dose monitoring.

Objective To analyze the status quo and existing problems of radiation protection for veterinary X-ray facilitiesin Beijing-Tianjin region, China, and to provide a basis for improving radiation protection management level. Methods According to the requirements of the Technical guidelines for status quo assessment of occupational hazard of the employing unit (AQ/T 4270—2015), the study performed status quo assessment on the workplaces of veterinary X-ray facilities in 16 pet hospitals in Beijing-Tianjin region, and comprehensively analyzed the impact of the workplaces on the health of radiation workers and the public. Results In terms of personnel management, the pass rates of occupational health management post setting, personnel training, personal protective equipment, individual monitoring of occupational external exposure, notification of occupational hazards, and occupational health surveillance were 100%, 81.3%, 100%, 75%, 37.5%, and 25%, respectively. In terms of workplace management, most workplaces had reasonable layout and zoning and complete protection and emergency devices. However, there were some problems in some places, such as non-standard radiation warning signs, no notice board of occupational hazards, and no radiation protection testing. In terms of document management, all institutions had imperfect system documents. Conclusion The workplaces of veterinary X-ray facilities in 16 institutions basically meet the requirements for radiation protection, but there are also some problems, such as inadequate management of personnel and workplace radiation protection, and imperfect system documents. Institutions should strengthen the study of radiation protection knowledge. The competent authorities should strengthen supervision, formulate corresponding standards for radiation protection, enhance training, and improve the professional level of staff.