Objective To track and evaluate the implementation and application of the occupational health standard Radiation shielding requirements for radiotherapy room—Part 4: Radiotherapy room of ²⁵²Cf neutron afterloading (GBZ/T 201.4-2015) by radiation health technical service agencies, medical institutions, health supervision agencies, and radiotherapy facility design units, and to provide a scientific basis for the further revision and implementation of this standard. Methods Following the Guideline for health standards tracking evaluation (WS/T 536-2017) and the project implementation plan, relevant practitioners were randomly selected for a questionnaire survey. The survey primarily focused on their awareness, standard training, application, and revision suggestions of GBZ/T 201.4-2015. The results were summarized and analyzed. Results A total of 168 evaluation questionnaires were collected from relevant practitioners in 28 provinces. Only 31.6% of the respondents reported being “well familiar” or “ familiar” with the standard, 27.4% of the respondents believed that the standard was widely used, and 45.2% of the respondents believed that the standard could meet the needs of their work. Only 14.9% of the respondents had received relevant training on the standard, more than half of the respondents had not applied the standard within the past 10 years, and 45.2% of the respondents believed that the standard "needs to be revised". Conclusion Due to the small number of californium-252 neutron afterloading radiotherapy devices in operation on the market, the overall awareness of the standard is low, suggesting that relevant authorities need to strengthen training and publicity of the standard, and that certain sections of the standard need to be revised or merged.

Objective　: To verify the feasibility of using a homemade lung phantom for quality control of Cyberknife by comparing the measurement results of the homemade lung phantom and CIRS dynamic phantom in E2E testing of Cyberknife lung tracking.  Methods　 : The patient treatment process was simulated, including CT positioning, plan design, irra- diation implementation, film scanning, and analysis using the homemade phantom and CIRS phantom. The two phantoms were measured five times using MLC under the S7 generation Cyberknife and five times using Iris under the M6 generation Cyberknife. The differences in measurement results between the two phantoms were analyzed using independent sample t-test. Results　: For the S7 generation Cyberknife, the statistical analysis of differences between the two phantoms in the detection values on the X-axis, Y-axis, Z-axis, and total deviation showed P values of 0.236, 0.175, 0.289, and 0.668, respect- ively. For the M6 generation Cyberknife, the statistical analysis showed P values of 0.880, 0.891, 0.573, and 0.433, respect- ively. The P values were all > 0.05. Therefore, there were no statistically significant differences in the detection results between the homemade lung phantom and the CIRS phantom under the S7 and M6 generation Cyberknife. The total deviation values were <1.5 mm. Conclusion　 The homemade lung phantom and CIRS phantom have consistent measurement results in the E2E testing of Cyberknife lung tracking and meet the requirements of Report of AAPM TG-135 and WS 667- 2019 standard. Therefore, the homemade lung phantom is feasible for clinical quality control of Cyberknife.

Radiomics is a new diagnostic and treatment technology,which can be employed to extract high-throughput radiomics features from CT,MR,and PET images and screen features closely related to diagnostic and treatment purposes,so as to accurately predict tumor or disease classification,prognosis,or genomic changes.Ki-67 is a type of nuclear protein,which is present only in nuclei of proliferative and dividing cells but not in those of quiescent phase cells;hence,it can be used as a predictor of cell proliferation and has been proven to be closely related to prognosis of lung cancer.This article reviews the mechanism and progress in radiomics research related to Ki-67 in lung cancer.

The incidence of refractory asthma in children is increasing year by year, bringing a heavy disease burden to families and society.As the immunological, pathophysiological and neurological mechanisms of asthma be elucidated, typeⅠallergic reactions mediated by the immunoglobulin E play an important role in the development of asthma.Omalizumab, targeting IgE, is using in clinical.This paper reviews the mechanism of action and clinical efficacy of omalizumab based on a review of the pathogenesis of refractory asthma, with the aim of guiding the individualized treatment of children with refractory asthma, improving the overall control rate.

Objective To explore the feasibility of quartz glass for radiotherapy dosimetry through the experimental study of the thermoluminescence characteristics of synthetic quartz glass. Methods The thermoluminescence glow curves of quartz glass under different annealing conditions were analyzed, the thermoluminescence characteristics of quartz glass were studied, and the measurement parameters were optimized. Using the Co-60 reference radiation field in the National Secondary Standard Dosimetry Laboratory, the quartz glass samples under different annealing conditions were irradiated following the dose levels of radiotherapy, i.e., 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 Gy, respectively. According to the relationship between the absorbed dose of quartz glass and the relative thermoluminescence signal intensity, the linearity and dispersion of the dose response of quartz glass were obtained, and the feasibility of quartz glass for radiotherapy dosimetry was analyzed. Results The linear correlation coefficient of dose response of quartz glass under annealing condition of 430℃ for 10 min was 0.9984, and the dose response dispersion was 0.97% at the absorbed dose of 2 Gy. The linear correlation coefficient of dose response of quartz glass under annealing condition of 600℃ for 1 h was 0.9911, and the dose response dispersion was 1.4% at the absorbed dose of 2 Gy. Conclusion Preliminary results suggest that quartz glass with annealing condition of 430℃ for 10 min has the potential to be used for radiotherapy dosimetry.

Objective: To discuss the feasibility of applying home-made auto quality assurance (AQA) phantom in Cyberknife AQA test. Methods: The same treatment plan for AQA test was designed in the Cyberknife treatment planning system. The AQA tests were performed under the same conditions using the home-made AQA phantom and the AQA phantom in the fourth-generation (G4) Cyberknife mode and the fifth-generation (VSI) Cyberknife mode, respectively, and each measurement was repeated five times to analyze and compare the differences in test results between the two phantoms. Results: The total deviations of the home-made AQA phantom and the AQA phantom in the AQA test under the G4 Cy- berknife mode were (0.28 ± 0.12) mm and (0.28 ± 0.15) mm, respectively (P > 0.05); the test results under the VSI Cy- berknife mode were (0.46 ± 0.19) mm and (0.50 ± 0.07) mm, respectively (P > 0.05); the total deviations of all test results were smaller than 1.0 mm, which met the requirements of WS 667—2019 Specification for Testing of Quality Control in Ro- botic Arm Radiotherapy Device. Conclusion The test results of the home-made AQA phantom and the AQA phantom are consistent in the AQA test, and the home-made AQA phantom can be used for Cyberknife quality control.

Objective To explore the relationship among the expression level of MMP?13, AGG and Col?II in the chon?drocytes caused by nutritional deficiencies in rabbits. Methods 30 New Zealand white rabbits were randomly divided into autolo?gous chondrocyte transplantation group (control group, n=10), nutrition block group (surgery group, n=10), and peripheral nutrition block group (sham surgery group, n=10). 4 weeks after treatment, the rabbits were sacrificed for undergoing the observations on general and histological level;real?time PCR assay was employed for testing the expression level of MMP?13, AGG and Col?II;cel?lular apoptosis percentage was observed through TUNEL stain. The relationship among the apoptosis level, cartilage cells histologi?cal Mankin score as well as the expression level of MMP?13, AGG and Col?II were analyzed. Results Based on the Mankin score, there was a statistic difference between surgery group and control group. On the other side, there were no statistic differenc?es between sham surgery group and control group. 4 weeks after treatment, surgery group presented a higher apoptotic percentage compared with control group;this value between sham surgery group and control showed no significant differences. There was an increased mRNA expression level of MMP?13 and a decreased mRNA expression level of AGG and Col?II in surgery group com?pared with control group;no statistic differences of all these values was found between sham surgery group and control group. His?tological Mankin score and apoptotic percentage presented positive correlation (r=0.922, P<0.001), the regression equation:Y=-0.548+0.404X, R2=0.844 (F=157.735, P<0.001); the mRNA expression level of MMP?13 and apoptotic percentage presented positive correlation (r=0.942, P<0.001), the regression equation:Y=0.951+0.116X, R2=0.883 (F=219.054, P<0.001). There was a nega?tive correlation between the mRNA expression level of MMP?13 and the mRNA expression level of AGG as well as Col?II (r=-0.956,-0.945, P<0.001). Conclusion Damage of cartilage cells causes the up?regulation of the MMP?13 expression which could ex?acerbate the degeneration of cells. It could induce the down?regulation of AGG and Col?II mRNA expression, which will cause the extracellular matrix synthesis disorder.

BACKGROUND:Due to limitations of the physicochemical properties of soft denture liner material itself, whisker has been added in the soft lining material in recent years, so as to enhance its mechanical properties. OBJECTIVE:To investigate the effect of different additive amount of anhydrous calcium sulfate whisker on the mechanical function of self-curing soft denture liner. METHODS: There were six groups in this experiment. Anhydrous calcium sulfate whisker at the mass fraction of 0 (control), 1%, 2%, 3%, 4%, 5% was respectively added into self-curing soft liner materials, 10 test specimens in each group, a total of 60 test specimens. The shear bond strength, Shore hardness and tensile strength were detected. RESULTS AND CONCLUSION: With the increasing amount of the anhydrous calcium sulfate whisker, the Shore hardness of the soft lining material was increased continuously, and the tensile strength was increased firstly and then reduced. When 3% anhydrous calcium sulfate whisker was added, the bond strength and tensile strength of soft lining material reached the peak. Taken together, the mechanical properties of the soft lining materials became perfect when 3% anhydrous calcium sulfate whisker was added. These results demonstrate that anhydrous calcium sulfate whisker may affect the mechanical properties of self-curing soft liner.