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Objective:To explore the value of using the mean gamma index (GI) in targer area receiving 50% prescribed dose as reference in VMAT planned dose verification through model-based dose calculation and measurement-based dose reconstruction.Methods:Based on Compass dose verificantion system, the VMAT plans for 70 patients were validated using two method. The mean GI and passing rate in target area receiving 50% of prescribed dose area for each validation plan were obtained to evaluate its application value in dose validation. First, plan information obtained by TPS calculation was input into the Compass system for performing independent dose calculation based on the accelerator data model, and obtain a three-dimensional dose based on the independent model calculation. The planned fluence measured for each patient′s treatment plan on the accelerator was reconstructed through the Compass system to obtain a three-dimensional dose based on measurement reconstruction. The three-dimensional dose obtained by the two method were compared with the three-dimensional dose calculated by TPS.Results:Combined with the gamma criteria of 3%/3 mm in the error setting condition of GI analysis, the mean GI in the area receiving 50% of prescribed dose was evaluated. GI≤0.4 was classified as PASS, 0.4 < GI ≤ 0.6 as being clinically acceptable, and GI > 0.6 as FAIL. The VMAT planned dose verification for 70 patients showed that the model-based independent calculation was in a better agreement with the TPS calculation. The GI values were all < 0.6: GI≤0.4 for 67 patients and 0.4 <GI≤ 0.6 for the other 3 patients, with gamma passing rate larger than 92%. The in- vivo measurement-based reconstructed 3D dose are slightly lesser than the model-based planed result ; theGI values were all < 0.6: GI ≤0.4 for 35 patients and 0.4 < GI ≤ 0.6 for other 35 patients, with gamma pass rate larger than 88%, of which gamma passing rate > 90% for 88 patients and < 90% for other 2, all meeting the requirements of clinical dose verification. The model-based independent dose verification is better than the measurement-based reconstructed dose verificantion, and the difference is statistically significant ( t=15.20, 10.71, P < 0.05). Conclusions:The mean GI in target area receiving 50% of prescribed dose can be used as a reference to judge the operatability of clinical plan in clinical dose verification. The mean GI value, in combination with the comprehensive result of gamma passing rate, is more convincing to evaluate dose verification. A combination of model-based dose verification, despite time-saving and labor-saving, and the measurement-based dose verification could become a reliable dose verification method for clinical application.
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Background Emerging evidence has shown the damage of air pollution and the benefits of physical activity to human health, and the effects of air pollution and physical activity on the nervous system need more research. Objective To explore the effects of short-term air pollution exposure and physical activity on neural damage biomarkers in healthy elderly. Methods Using a design of panel study, physically and mentally healthy retired employees were recruited from Xinxiang Medical University, and were followed up five times regularly from December 2018 to April 2019. The demographic characteristics and physical activity information were obtained by questionnaire, and the weekly physical activity level was calculated according to intensity and duration of physical activity. Biomarkers of neural damage in serum were measured, including brain-derived neurotrophic factor (BDNF), neurofilament light chain (NF-L), neuron specific enolase (NSE), protein gene product 9.5 (PGP9.5), and S100 calcium-binding protein B (S100B). Air pollution data (including PM2.5, PM10, O3, SO2, CO, and NO2) of the follow-up period were collected. Generalized estimation equation was used to analyze the association of air pollution concentration and physical activity level with the concentration of neural damage biomarkers. Results A total of 29 volunteers were included in the study, with an average age of (63.5±5.9) years; there were 11 men accounting for 37.93%; more than half of them (62.07%) received above junior middle school education; the mean physical activity level was (80.23±54.51) MET-h·week−1. The daily average concentrations of PM2.5, PM10, O3, SO2, CO, and NO2 during the study period were (68.27±60.98) μg·m−3, (130.57±58.71) μg·m−3, (36.86±13.89) μg·m−3, (17.86±10.59) μg·m−3, (4.94±1.34) mg·m−3, and (50.83±8.03) μg·m−3, respectively. The average serum concentrations of BDNF, NF-L, NSE, PGP9.5, and S100B were (139.12±46.71) μg·L−1, (402.60±183.31) ng·L−1, (11.26±10.32) ng·L−1, (14.32±13.57) ng·L−1, and (127.57±41.74) ng·L−1, respectively. The results of generalized estimation equation showed that a higher concentration of PM2.5 or O3 was associated with increased serum NSE (OR=1.359, 95%CI: 1.224-1.509, P<0.001; OR=1.286, 95%CI: 1.076-1.537, P=0.006), while a higher concentration of NO2 was associated with decreased serum NSE (OR=0.692, 95%CI: 0.549-0.873, P=0.002); a higher concentration of O3 or SO2 was related to the reduction of serum NF-L concentration (OR=0.855, 95%CI: 0.740-0.989, P=0.035; OR=0.813, 95%CI: 0.700-0.946, P=0.007); a higher concentration of NO2 was associated with decreased PGP9.5 in serum (OR=0.866, 95%CI: 0.777-0.965, P=0.009); a higher level of physical activity was associated with increased serum S100B (OR=1.038, 95%CI: 1.003-1.074, P=0.034); and no significant association of physical activity level or air pollution with BDNF (P>0.05). Conclusion Acute exposure to air pollution and high-level physical activity might affect the neural damage of elderly populations. Specifically, particulate matter (PM2.5) could increase NSE, while gaseous pollutants (O3, NO2, and SO2) could decrease NF-L and PGP9.5.
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【Objective】 To investigate the effects and potential mechanisms of neurodegenerative lesions in male mice caused by ozone exposure. 【Methods】 We divided 23 C57BL/6N male mice aged 8 to 9 months into control group （clean air group， 11） and ozone group （1 mg/m 3， 4h/d， 12）. After 8 weeks of continuous ozone exposure， the Morris water maze experiment was used to detect the mice’s learning and memory ability， HE dyeing to observe pathological changes in hippocampal tissue cells， and immunoprinting tests to detect the expression levels of Tau， p-Tau and α-synuclein proteins in the cerebral cortex tissue. 【Results】 After 8 weeks of ozone exposure， the mice’s spatial learning and memory ability were impaired to a certain extent， the incubation period decreased with time， and the two lines were separated， but the difference was not statistically significant. Ozone exposure caused changes in the morphology of the mice’s hippocampal tissue cells， disorders in the arrangement of hippocampal neuron， and nuclear wrinkles， and significantly increased levels of p-Tau and α-synuclein protein expressions in cerebral cortex tissues （P<0.01）， but there was no statistical significance in the total Tau expression level. 【Conclusion】 Ozone exposure leads to the loss of learning and memory in mice， changes in hippocampal neurocellular pathology， and increased expression levels of neurodegenerative variable-related proteins.
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Objective@#To discuss the application of failure mode and effect analysis to improve the hand hygiene compliance of medical staff in eye hospital.@*Methods@#To form failure mode and effect analysis (FMEA) quality control team. By using FMEA method of risk management, to analyze the risk factors of hand hygiene compliance of medical staff in eye hospital. By performing analysis, to determine the high risk factors, develop and implement the improvement measures to reduce the risk of these factors.@*Results@#the awareness rate of hand hygiene knowledge was increased significantly after the implementation of failure mode and effect analysis (P<0.01) , the correct rate of hand-washing method, and the implementing rate of 5 hand hygiene were increased significantly (P<0.05) . After the implementation of FMEA, the usage amount of hand washing liquid and quick hand disinfectant was increased from 13 292 ml to 28 390 ml, and difference of the hand hygiene qualification rate was statistically significant (P<0.05) .@*Conclusion@#The application of FMEA contributes to analyze the causes of hand hygiene failure, and guide the development of improvement measures, which can effectively improve the hand hygiene compliance of medical staff, thereby reducing nosocomial infection.
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Objective To compare the efficacy and indications between the biliary bypass laparotomy surgery.and the two different kinds of biliary stent insertion surgery in the palliative alleviating jaundice of cholangiocarcinoma.Methods From March 2008 to March 2013,69 patients treated with palliative alleviating jaundice therapy of cholangiocarcinoma were included,who were all came from the Third Affiliated Hospital of Guangzhou Medical University.Including 17 patients who treated with the open biliary bypass surgery and 52 patients who treated with interventional therapy.We analysed the differences between these cases of biliary drainage operations in the recent jaundice reduction rate,average stay,mortality rate,the incidence of related complications,et al.Results All these different drainage ways had good effect in alleviating jaundice,incidence of alleviating jaundice have no obvious difference (P ＞ 0.05).Compared to the open biliary bypass surgery,interventional therapy had obvious advantages in the average stay and postoperative survival (P ＜ 0.05).The pancreatitis rate was lower in Percutaneous Group than that in Endoscopic Group (P ＜ 0.05).incidence of biliary tract infection and biliary tract bleeding have no obvious difference (P ＞ 0.05).There were no significant differences between the success rates of in biliary stent insertion operation in patients with each model cholangiocarcinoma (P ＞ 0.05).Conclusions Among the therapies of the palliative alleviating jaundice of cholangiocarcinoma,the internal biliary drainage of biliary stent insertion operation was superior to the treatment of the biliary bypass laparotomy.As to biliary stent insertion operations,endoscopic biliary stenting surgery should be the preferred choice.