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To investigate the γ pass rate limit of plan verification equipment for volumetric modulated arc therapy (VMAT) plan verification and its sensitivity on the opening and closing errors of multi-leaf collimator (MLC), 50 cases of nasopharyngeal carcinoma VMAT plan with clockwise and counterclockwise full arcs were randomly selected. Eight kinds of MLC opening and closing errors were introduced in 10 cases of them, and 80 plans with errors were generated. Firstly, the plan verification was conducted in the form of field-by-field measurement and true composite measurement. The γ analysis with the criteria of 3% dose difference, distance to agreement of 2 mm, 10% dose threshold, and absolute dose global normalized conditions were performed for these fields. Then gradient analysis was used to investigate the sensitivity of field-by-field measurement and true composite measurement on MLC opening and closing errors, and the receiver operating characteristic curve (ROC) was used to investigate the optimal threshold of γ pass rate for identifying errors. Tolerance limits and action limits for γ pass rates were calculated using statistical process control (SPC) method for another 40 cases. The error identification ability using the tolerance limit calculated by SPC method and the universal tolerance limit (95%) were compared with using the optimal threshold of ROC. The results show that for the true composite measurement, the clockwise arc and the counterclockwise arc, the descent gradients of the γ passing rate with per millimeter MLC opening error are 10.61%, 7.62% and 6.66%, respectively, and the descent gradients with per millimeter MLC closing error are 9.75%, 7.36% and 6.37%, respectively. The optimal thresholds obtained by the ROC method are 99.35%, 97.95% and 98.25%, respectively, and the tolerance limits obtained by the SPC method are 98.98%, 97.74% and 98.62%, respectively. The tolerance limit calculated by SPC method is close to the optimal threshold of ROC, both of which could identify all errors of ±2 mm, while the universal tolerance limit can only partially identify them, indicating that the universal tolerance limit is not sensitive on some large errors. Therefore, considering the factors such as ease of use and accuracy, it is suggested to use the true composite measurement in clinical practice, and to formulate tolerance limits and action limits suitable for the actual process of the institution based on the SPC method. In conclusion, it is expected that the results of this study can provide some references for institutions to optimize the radiotherapy plan verification process, set appropriate pass rate limit, and promote the standardization of plan verification.
Subject(s)
Humans , Radiotherapy, Intensity-Modulated , Immune Tolerance , Nasopharyngeal Carcinoma , ROC Curve , Nasopharyngeal Neoplasms/radiotherapyABSTRACT
OBJECTIVE@#To explore the feasibility of using the bidirectional local distance based medical similarity index (MSI) to evaluate automatic segmentation on medical images.@*METHODS@#Taking the intermediate risk clinical target volume for nasopharyngeal carcinoma manually segmented by an experience radiation oncologist as region of interest, using Atlas-based and deep-learning-based methods to obtain automatic segmentation respectively, and calculated multiple MSI and Dice similarity coefficient (DSC) between manual segmentation and automatic segmentation. Then the difference between MSI and DSC was comparatively analyzed.@*RESULTS@#DSC values for Atlas-based and deep-learning-based automatic segmentation were 0.73 and 0.84 respectively. MSI values for them varied between 0.29~0.78 and 0.44~0.91 under different inside-outside-level.@*CONCLUSIONS@#It is feasible to use MSI to evaluate the results of automatic segmentation. By setting the penalty coefficient, it can reflect phenomena such as under-delineation and over-delineation, and improve the sensitivity of medical image contour similarity evaluation.
Subject(s)
Feasibility Studies , Radiotherapy Planning, Computer-AssistedABSTRACT
OBJECTIVE： To compare inhibitory effects of ethanol extract of different medicinal parts （root， stem， leaf， seed， flower and flesh） from Syzygium jambos on the activities of α-glycosidase and α-amylase. METHODS： Using half-inhibitory concentration value （IC50） as evaluation index， acarbose as positive control， inhibitory effects of ethanol extract of different medicinal parts from S. jambos on the activities of α-glycosidase （from yeast and small instestine in mice） and α-amylase were evaluated with in vitro inhibition model. The enzymatic dynamics and Lineweaver-Burk methods were used to analyze the inhibitory type of the best medicinal part on the activities of α-glycosidase and α-amylase. RESULTS： In the yeast α-glucosidase inhibitory activity test， the order of inhibitory activity was S. jambos seed＞S. jambos stem＞S. jambos leaf＞S. jambos root＞S. jambos flower＞S. jambos flesh＞acarbose. In the mice intestine α-glucosidase inhibitory activity test， the order of inhibitory activity was S. jambos seed＞S. jambos stem＞S. jambos root＞S. jambos leaf＞S. jambos flower＞S. jambos flesh＞acarbose. In the α-amylase inhibitory activity test， the order of inhibitory activity was acarbose＞S. jambos seed＞S. jambos stem＞S. jambos root＞S. jambos leaf＞S. jambos flesh＞S. jambos flower. Ethanol extract of S. jambos seed had the stronger inhibition activity against α-glucosidase from yeast，α-glucosidase from small intestine in mice and α-amylase than other medicinal parts [IC50 were（6.64±0.24）， （32.77±2.46） and （41.18±1.63） μg/mL]. Ethanol extract of S. jambos seed had the stronger inhibition activity against α-glucosidase than acarbose [IC50 to α-glucosidase from yeast and α-glucosidase from small intestine in mice were （2 833.33±5.48）， （1 304.21±6.45） μg/mL] （P＜0.05）. The inhibitory effect of ethanol extract from S. jambos on the activity of α-amylase was less than that of acarbose [IC50 was （27.27±1.24） μg/mL] （P＜0.05）. Enzymatic dynamics showed that the inhibitory type of ethanol extract from S. jambos seed on α-glucosidase and α-amylase were both reversible competitive inhibition. CONCLUSIONS： Among different parts of S. jambos such as root， stem， leaf， seed， flower and flesh， S. jambos seed shows the strongest inhibitory effects on the activities of α-glucosidase and α-amylase， which has the value of being developed for the treatment of diabetes or health food.
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OBJECTIVE： To investigate in vitro antibacterial activity of the extracts from the root， stem and leaves of Psychotria rubra， and to investigate its mechanism of antibacterial effects. METHODS： 95％ ethanol extracts from the root， stem and leaves of P. rubra were used to prepare solution with mass concentration of 100 mg/mL （calculated by extract）. Using as penicillin sodium （0.5 mg/mL） and streptomycin sulfate （128 mg/mL） as positive control， plat stiletto method was used to determine antibacterial effects of the extracts from different parts of Staphylococcus aureus， Escherichia coli， Pseudomonas aeruginosa， Bacillus subtilis， Micrococcus luteus and Enterococcus faecalis. Using systematic solvent extraction method， the petroleum ether， ethyl acetate and n-butyl alcohol were used to extract antibacterial activity parts from P. rubra as ad to obtain the extracts of corresponding polar parts. After preparing 100 mg/mL drug solution （calculated by extract）， antibacterial effects of above 6 kinds of bacteria were investigated. The micro-broth dilution method and agar culture medium plate method were used to determine minimum inhibitory concentration （MIC） and minimum bactericidal concentration （MBC）， and screen polar parts with bacteriostasis and drug-sensitive strains. Under the concentration of 0.5MIC and MIC， the growth curves of sensitive bacteria were drawn （treated for 36 h， every 4 h）； the contents of alkaline phosphatase （AKP） and soluble protein were detected in suspension （treated for 10 h， every 2 h）； bouillon culture medium instead of the extract as blank control. RESULTS： 100 mg/mL ethanol extracts from the root， stem and leaves of P. rubra showed good antibacterial effect to above 6 kinds of bacteria， in descending order as stem＞leaves＞root. Among different polar parts from the stem of P. rubra， antibacterial effect of the ethyl acetate extract was best， especially for the S. aureus， the diameter of inhibition zone reached （38.93±0.12） mm， and both MIC and MBC were 0.39 mg/mL. The ethyl acetate extract could significantly inhibit the proliferation of S. aureus， and its alkaline phosphatase and protein content in suspension were increased significantly compared with blank control （P＜0.05）. CONCLUSIONS： The stem from P. rubra is effective antibacterial parts， and exhibit good antibacterial activity to 6 kinds of common pathogens. The ethyl acetate extract from the stem of P. rubra shows strongest antibacterial effect on S. aureus， and could gradually destroy the integrity of cell wall and cell membrane.
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Specific to the existing problems of uneven distribution of resources in the medical industry,especially the shortage of grass-root high-quality medical resources,the paper introduces the construction objective,overall architecture and construction contents of regional medical collaboration,and normalizes the medical service process through informationalized technological means,in order to promote standardized construction of the regional medical information system and information interconnection and intercommunication.
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The paper elaborates on the construction concept ofHealthy Henan Health Service Cloud and introduces the project goals and system architecture.This platform effectively promotes the application and popularization of achievements in health informatization in Henan,enables the basic mass to experience the efficiency and convenience brought about by health informatization,and facilitates the monitoring and management by health administrative departments.
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<p><b>OBJECTIVE</b>To separate and identify chemical constituents from Coptis chinensis.</p><p><b>METHOD</b>The compounds were separated and purified by various chromatographic techniques. Their structures were identified on the basis of their physicochemical properties using spectral techniques such as NMR and MS.</p><p><b>RESULT</b>Thirteen compounds were separated from ethanol extracts of C. chinensis, including seven lignans, three simple phenylpropanoids, two flavones and one phenolic acid, and identified as erythro-guaiacylglycerol-8-O-4'-(coniferyl alcohol) ether (1), threo-guaiacylglycerol-8-O-4'-(coniferyl alcohol) ether (2), (+)-pinoresinol (3), (+)-medioresinol (4), (+)-lariciresinol (5), (+)-5'-methoxylariciresinol (6), (+)-isolariciresinol (7), chlorogenic acid (8), ferulic acid (9), Z-octadecyl caffeate (10), rhamnetin (11), wogonin (12), and vanillic acid (13).</p><p><b>CONCLUSION</b>Compounds 1, 2, 4, 6, 10-13 were separated from the genus Coptis for the first time.</p>