Objective To study the protective effect and Bcl-2 expression of salvia miltiorrhiza pretreatment on retinal ischemia-reperfu-sion injury ( RIRI) . Methods One hundred and thirty two Wistar rats were randomly divided into the normal control group, the ischemia-reperfusion group and the salvia miltiorrhiza pretreatment group. The model of retinal ischemia-reperfusion injury was constructed by increas-ing the intraocular pressure. The ischemia-reperfusion and salvia miltiorrhiza pretreatment group were divided into five subgroups according to the different reperfusion time (6 h, 12 h, 24 h, 48 h and 72 h). Observe the histological changes in retina by HE staining. The SABC ( strept avidin-biotin complex) and Western-blot were used to measure changes of Bcl-2 protein levels in retinal. Results The positive ex-pression of Bcl-2 protein was weak in normal group. In the ischemia-reperfusion group and salvia miltiorrhiza pretreatment group, the expres-sion of Bcl-2 protein began to increase at 6 hours after reperfusion, reached the peak at 24 hours after reperfusion, began to decrease at 48 hours after reperfusion, and started to weaken at 72 hours after reperfusion. The variation tendency of the two groups were the same, however, the expression of Bcl-2 was significantly stronger in the salvia miltiorrhiza pretreatment group compared with ischemia-reperfusion group, and there was significant difference between the two groups (P<0. 01). Conclusion Salvia miltiorrhiza pretreatment can protect the retina by reducing retinal ganglion cells apoptosis in retinal ischemia-reperfusion injury. The mechanism may be achieved by regulating the expression of Bcl-2 protein.

Objective To explore the relationship between plasma homocysteine levels and diabetic retinopathy (DR).MethodIn 40 DR patients and 63 non-DR patients,the indexes including plasma homocysteine concentrations,duration of diabetes,ages,blood pressure,preprandial blood glucose(PBG),plasma GHbA,e,plasma lipids,serum folie acid and semm vitamin B12 were analyzed.ResultsPlasma homocysteine level was significantly higher in DR patients (12.9μmol/L) than that in non-DR patients (7.8μ.mol/L) (P＜0.01),and the relationship remained significant correlation after adjusted for duration of diabetes,GHbA1c,ages,serum folic acid and serum vitamin B12(OR = 1.23,P＜0.05).ConclusionHyperhomocysteinimia is a risk factor and an independent predieator of DR.

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.

Objective To explore the relationship between plasma homocysteine levels and diabetic peripheral neuropathy (DPNP). Methods A crossectional analysis was conducted on 227 patients with type 2 diabetes. Peripheral neuropathy was confirmed using electromyography (EMG). The risk factors possibly associated with diabetic neuropathy or plasma homocysteine levels were analyzed in relation to likelihood of occurrence of DPNP. Results Eighty patients with neuropathy and 147 patients without neuropathy were included. Plasma homocysteine levels were significantly higher in patients with diabetic neuropathy [( 12. 6 ± 3.6 ) μmol/ L] than without diabetic neuropathy [( 8. 2 ± 0. 9 ) μmol/L] ( P ＜0. 001 ), and the relationship remained significant after adjusting for duration of diabetes, glycosylated hemoglobin A1c (HbA1c), age, renal status, serum folate acid and vitamin B12, and metformin [OR 1.15( 1.02-1.28 ) ,P ＜ 0. 05]. In addition, per increase of 4. 0 μmol/L plasma homocysteine was closely related to the occurrence of neuropathy after controlling for per unit increase of other confounding factors [OR 1.17(0. 94-1.33), P ＜ 0. 05]. Conclusions Hyperhomocysteinemia was an independent risk factor for the occourence of diabetic peripheral neuropathy.

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 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.