对数线性模型在临床试验资料分析中的应用

目的 选择适合药物临床试验列联表资料分析方法,为药物的疗效、安全性和不良反应等提供科学依据.方法 利用对数线性模型,讨论多维列联表分析的优势.结果 与结论临床试验中经常接触到多维列联表的数据,对这类数据需采用特殊的方法进行分析处理.     

对数线性模型在分析蒙古族农牧民吸烟与高血压关系中的应用

近年来 ,列联表资料分析方法的应用越来越广泛 ,L ogistic回归分析在算出危险因子的相对危险性对使疾病与致病因子间的联系得以揭示 ,但表的维数增加 ,尤其是几个因素无法确定因变量时 ,给这些方法带来了许多问题 ,除不能对各变量之间的关系给出一个系统评价外 ,也不能对变量的效应进行估计。在考虑可能存在的交互影响时 ,χ2检验、L ogistic模型等就很难胜任 ,特别是遇到更为复杂的列联表资料时。为此 ,对数线性模型 (L og- L inear Model)是值得推荐的统计方法之一 ,本文用该法探讨了蒙古族农牧民吸烟与高血压的关系。在内蒙古哲里木盟…     

二维表对数线性模型分析和熵的分解

对定性资料构成的二维表进行了分析 ,并引出熵的分解和相应统计量     

母乳喂养影响因素的对数线性模型分析

在对母乳喂养影响因素单因素处理的基础上,采用多因素逐步回归分析筛选了对母乳喂养作用显著的7个因素,即难产、分娩年龄过大、孕期患病、月经恢复时间早、产后食欲差、产后照顾差、家族缺奶史。用非条件log istic回归分析求出了影响因素的危险度,然后,建立了对数线性模型:logm=u+u1,3+u2,3+u4+u5+u6+u7。从模型中进一步说明,母乳喂养除与产后月经恢复时间过早、产后食欲差、产后照顾差及家族缺奶史有关外,提示孕期患病不是直接的影响因素,而是难产与孕期患病的交互作用,及分娩年龄过大与孕期患病的交互作用,交互作用对母乳喂养产生影响。     

对数线性模型与对应分析在临床列联表资料中的结合应用

对数线性模型和对应分析都是可以处理列联表资料的有用工具,而且都可以研究变量之间的相互关系。对应分析可以通过其因子载荷平面图,用直观的方式表达变量间的关系,找到有相关关系的变量,为对数最优线性模型的选择提供有用的信息。     

以对数线性模型拟合多维列联表资料

以对数线性模型拟合多维列联表资料周家仪（南京医科大学统计学教研室南京２１００２９）统计线性模型是描述和检验变量之间的关系。回归模型是描述因变量与若干自变量之间的关系，并对各自变量作检验；方差分析模型是检验各因子对因变量的影响，因子之间的交互作用的影响...     

捕获-再捕获资料的对数线性模型及其在估计婴儿死亡人数中的应用

介绍了捕获 -再捕获方法的对数线性模型 ,并应用于估计广州番禺市 1999年的婴儿死亡人数     

捕获—再捕获资料的对数线性模型及其在估计婴儿死亡人数 …

介绍了捕获 -再捕获方法的对数线性模型 ,并应用于估计广州番禺市 1999年的婴儿死亡人数     

对数正态模型及饮酒房室模型在血药酒精浓度曲线模拟中的应用

将对数正态模型和饮酒房室模型用于血药酒精浓度随时间变化曲线的模拟,对数正态模型和房室模型均能较好的模拟酒精血药浓度变化过程。配对t检验显示,对数正态模型与房室模型的模拟结果相一致;分别计算两种模拟结果的峰浓度和达峰时间,结果基本一致。     

线性回归结合灰色模型在门诊量预测中的应用

应用线性回归技术和 GM( 1,1)灰色模型对某院 1990～ 1999年门诊量进行了分析预测。结果表明 ,两种方法的加权组合预测误差较小 ,能为医院科学决策提供依据 ,是一种较好的预测方法。     

改良坐骨神经慢性压迫性损伤模型的建立

目的:建立稳定可靠的坐骨神经慢性压迫模型.方法:健康、成年、雄性SD大鼠24只随机分为3组,即传统CCI组、改良CCI组和sham组(即假手术组),分别在手术前(0 d)及术后2、4、6、8、10、12、14 d记录大鼠足底热痛潜伏期(热痛阈)变化和大鼠的行为学改变.结果:传统CCI组和改良CCI组均出现痛过敏现象,但改良CCI组痛过敏稳定、持久,自噬现象较传统CCI组少.结论:改良CCI模型稳定、可靠,减少了自噬行为所带来的感染风险,为研究神经病理性疼痛的发生、发展机制,尤其是免疫机制提供了更合适的实验条件.     

改良坐骨神经慢性压迫性损伤模型的建立

目的:建立稳定可靠的坐骨神经慢性压迫模型.方法:健康、成年、雄性SD大鼠24只随机分为3组,即传统CCI组、改良CCI组和sham组(即假手术组),分别在手术前(0 d)及术后2、4、6、8、10、12、14 d记录大鼠足底热痛潜伏期(热痛阈)变化和大鼠的行为学改变.结果:传统CCI组和改良CCI组均出现痛过敏现象,但改良CCI组痛过敏稳定、持久,自噬现象较传统CCI组少.结论:改良CCI模型稳定、可靠,减少了自噬行为所带来的感染风险,为研究神经病理性疼痛的发生、发展机制,尤其是免疫机制提供了更合适的实验条件.     

Induction of Apoptosis in Cancer Cells by Glutathione Transferase Inhibitor Mediated Hydrophobic Tagging Molecules

The abnormally high expression of glutathione transferases is closely associated with cancer incidence and drug resistance. By introducing a hydrophobic moiety to the inhibitor structure, we organized a series of degraders of glutathione transferases and demonstrated them potently inducing apoptosis in cancer cells, presenting their pharmacological potential in cancer therapy.     

羧烷基化合成萘普生工艺改进

１－溴－２－甲氧基萘与０－对在苯磺酰乳酸乙酯（１）在无水氯化铝催化下化Ｆｒｉｅｄｅｌ－Ｃｒａｆｔｓ反应，还原脱溴直接合成ｄｌ－１ａ萘普生（３），以上反应均在“一锅”内完成，收率达９５。     

Improved risk assessment by screening sperm parameters

The question of whether a 4 or 9 week premating treatment period is more suitable in studies for effects on fertility and early embryonic development, and the extent to which the screening of sperm parameters may contribute to the detection of effects, has been under discussion since the ICH guideline changed in 1994/1995. This study presents a comparison between 4 and 9 weeks treatment with known male reproductive toxicants with regard to sperm motility, count, morphology, abnormal movements and testicular and epididymal histopathology. Mating outcome was examined after 4 weeks treatment. Three compounds with different targets and mechanisms of action were chosen: two testicular toxicants, Pyridoxine and Adriamycin and the epididymal toxicant, alpha-Chlorohydrine. Sperm motility was reduced in males treated with Pyridoxine (markedly) and alpha-Chlorohydrine (slightly) after 4 weeks treatment and in males treated with Adriamycin after 9 weeks treatment. With Pyridoxine and Adriamycin, sperm count was significantly increased after 4 weeks. Histopathological examination after 4 weeks showed characteristic changes leading to marked testicular tubular atrophy at 8/9 weeks, which was confirmed by a significantly reduced sperm count at 8/9 weeks. With alpha-Chlorohydrine, sperm count was not affected and the results of the histopathological examination were equivocal. Changes in sperm morphology were observed after 4/9 weeks of treatment with Pyridoxine. Mating outcome after 4 weeks was markedly affected with both Pyridoxine and alpha-Chlorohydrine, but no effect was observed with Adriamycin. The results of this study indicate that the two testicular toxicants would have been detected as male reproductive toxicants in a 4-week general toxicity study with routine testicular histopathology and examination of sperm parameters, without the need for mating trials. For the epididymal toxicant, alpha-Chlorohydrine, there was slightly reduced sperm motility after 4 weeks treatment, but mating trials were necessary for confirmation of the toxic effect. Without sperm motility examination, this effect would have been missed in early drug development causing problems in clinical studies. Further comparisons of the validity of 4 or 9 weeks treatment require the testing of other compounds with different targets/mechanism of actions, as well as evaluation of dose-response relationships.     

Improved food additive analysis by ever-increasing nanotechnology

Improper use of food additives may lead to potential threat to human health, making it important to develop sensitive and selective method for their detection. Nanomaterials with unique chemical and electrochemical properties show extensive applications in the design of food additive sensing systems. In this review, we summarize the recently adopted electrochemical and optical analysis of food additives based on nanomaterials. Detection of typical food additives (colorants and preservatives) by using different sensing mechanisms and strategies are provided. In addition, determination of illegal food additives is also briefly introduced. Finally, this review highlights the challenges and future trend of nanomaterial-based food analysis system.     

Improved phosphotyrosine analysis by TLC and HPLC

We describe here the conditions of thin layer chromatography (TLC) and high pressure liquid chromatography (HPLC) to improve the analytical method of phosphotyrosine (P-Tyr) in biological sample. TLC was performed on silica plate with the mixture of propanol and water (2.1∶1 v/v) as a mobile phase and R₁ values were 0.42, 0.39 and 0.33 for phosphotyrosine, phosphothreonine and phosphoserine, respectively. HPLC was performed on NH₂ column with a mobile phase of potassium biphosphate solution by UV detection at 192 nm. The optimum condition of HPLC was obtained at 0.01 M, pH 4.5 with a clear separation within 12 min. These procedures have been applied to the analysis of phosphotyrosine obtained from tyrosine-phosphorylated enolase. Both TLC and HPLC methods were suitable to analyze tyrosine-phosphorylated protein without being affected by contaminants from hydrolysates.     

三光气法合成盐酸甲哌卡因的工艺改进

目的 研究三光气法合成盐酸甲哌卡因。方法 以三光气为氯化试剂，NaOH为N-甲基化缚酸剂，2-哌啶甲酸经酰氯化、酰胺化、N-甲基化、成盐得盐酸甲哌卡因。结果 合成盐酸甲哌卡因总收率为68．1％，中间体N-（2，6-二甲苯基）-2-哌啶甲酰胺的收率由50．1％提高到73．9％，N-甲基化收率由90．0％提高到96．0％。结论 整个工艺反应条件温和，操作简单，对环境友好。