目的通过研究不同密度模体创建的CT值密度曲线(Image Value to Density Table,IVDT)对剂量计算精度的影响,探讨如何在Tomotherapy计划系统中正确创建IVDT。方法分别用Gammex和CIRS两种密度模体创建立应的IVDT表,其中以是否含有空气密度...目的通过研究不同密度模体创建的CT值密度曲线(Image Value to Density Table,IVDT)对剂量计算精度的影响,探讨如何在Tomotherapy计划系统中正确创建IVDT。方法分别用Gammex和CIRS两种密度模体创建立应的IVDT表,其中以是否含有空气密度点和在CT值-100~100 HU范围内是否包含除水以外的物质密度点分别创建IVDT表。调用不同IVDT表设计4组调强计划,同时生成7组剂量传输验证计划(Delivery Quality Assurance,DQA),测量上述11组调强计划的剂量偏差并进行配对t检验判断IVDT表是否符合要求。结果IVDT表中含有-100~100 HU计划组剂量偏差为1.55%±0.9%,与标准计划组剂量偏差比,有统计学差异(P<0.01),同理,不含空气密度点组的剂量偏差也有明显剂量学差异。7组DQA计划中调用CIRS IVDT Abdo(-100~100 HU)、Gammex IVDT Abdo(standard)的5组DQA计划剂量偏差,无统计学差异(P>0.05);调用CIRS IVDT Abdo(-100~100 HU)的2组DQA计划平均剂量偏差均为1.77%±1%,与对照组剂量偏差相比,有统计学差异。结论创建IVDT表时需要确保CT值在-100~100 HU范围内除水以外不含任何其他物质密度点,同时曲线中应该加入空气密度点,此两点对剂量计算精度影响较大。展开更多
Objective:To learn a scientific and systematic knowledge of anticancer,antimicrobial and pharmacological activities of natural products and estimate cytotoxic potency by using ethanol and chloroform extracts of root,l...Objective:To learn a scientific and systematic knowledge of anticancer,antimicrobial and pharmacological activities of natural products and estimate cytotoxic potency by using ethanol and chloroform extracts of root,leaf and stem of Clerodendrum infortunatum(Verbenaceae)due to its random use in customary and traditional medicine to cure common ailments such as intestinal disorder,diarrhea,tuberculosis and respiratory problems etc.Methods:The in vitro application was carried out with the bench-top bioassay method by using brine shrimp lethality bioassay.Results:All of the crude extracts were found to be lethal and effective.The LC50 value of ethyl alcohol fraction of root was 20.845 mg/L compared to the standard drug tetracycline of 14.675 mg/L to brine shrimp nauplii,indicating that the extracts were biologically active.Conclusions:The cytotoxic study of LC50 value showed that a good correlation with the antibiotic tetracycline.From the comparative correlation error bars and percentage,we understood that ethyl alcohol fraction of root extract was very effective.This study serves as a basis for further research to lead compounds to be isolated so that it may be as a template for the implications of these results for bioactivity and drug discovery potential of herbal products.展开更多
基金Supported by Ministry of Science and Information&Communication Technology,Government of the Peoples Republic of Bangladesh under the project of Research and Development(Grant No.Bitojopromo/sha-12/goupro-8/2008/268).
文摘Objective:To learn a scientific and systematic knowledge of anticancer,antimicrobial and pharmacological activities of natural products and estimate cytotoxic potency by using ethanol and chloroform extracts of root,leaf and stem of Clerodendrum infortunatum(Verbenaceae)due to its random use in customary and traditional medicine to cure common ailments such as intestinal disorder,diarrhea,tuberculosis and respiratory problems etc.Methods:The in vitro application was carried out with the bench-top bioassay method by using brine shrimp lethality bioassay.Results:All of the crude extracts were found to be lethal and effective.The LC50 value of ethyl alcohol fraction of root was 20.845 mg/L compared to the standard drug tetracycline of 14.675 mg/L to brine shrimp nauplii,indicating that the extracts were biologically active.Conclusions:The cytotoxic study of LC50 value showed that a good correlation with the antibiotic tetracycline.From the comparative correlation error bars and percentage,we understood that ethyl alcohol fraction of root extract was very effective.This study serves as a basis for further research to lead compounds to be isolated so that it may be as a template for the implications of these results for bioactivity and drug discovery potential of herbal products.
