Heterogeneity of Cancer Risk Due to Stochastic Effects

Persons with exactly the same genetic background, behavior, environment, etc. may have differences in cancer risk due to a different number of cells on the way to malignancy. These differences are estimated quantitatively by using the two-stage clonal expansion model. For liver cancer the estimated relative risk for persons without intermediate cells at age 40 is less than 10% when compared to the risk of the total population, while the top 0.1% risk group has a more than 100-fold risk compared to the population. The risk of the 1% percentile in risk is more than 100-fold of the risk of the more than 95% persons without intermediate cells. The number of intermediate (premalignant) cells in the risk groups cannot be calculated from incidence data only because they depend strongly on a nonidentifiable parameter. But under plausible assumptions, less than about 1,000 intermediate cells are present at age 40 even in high-risk persons.     

加压碱法提取香蕉茎干中膳食纤维的研究

以香蕉茎干为原料,研究了先过滤出直接水提液,再加压碱处理残渣提取膳食纤维的工艺及其操作条件,结果表明,SDF干基产率达到20．85％,IDF干基产率达43．12％．     

《词源》片论

本文从雅正词体本质观、以姜夔为词美理想范型、讲论词法的得失三个方面对《词源》下卷内容进行了论列。认为《词源》的词体本质观,是对两宋以来文人词和民间俗词分流、互动以及文人词内部变革两方面因素作出的一种主流趋势的凝结,也是南宋以来“复雅尊体”思潮辩证扬弃的必然产物;沈义父的《乐府指迷》以周邦彦为典范和《词源》以姜夔为圭臬,涉及的是雅词内部的不同审美理想,并不是根本的对立;《词源》在入元之后对宋词作法经验方面的概括总结,这实际上也显示着词体文学高峰期的结束,所谓“嗟古音之寥寥,虑雅词之落落”既包含扶正示范的意思,更有为一代文学总结之意。     

光源对于太阳能电池基本特性测量实验影响的研究

本文研究了光源对于太阳能电池基本特性测量实验的影响。分别采用白炽灯和日光灯作为光源,测量了太阳能电池的伏安特性、开路电压、短路电流、最大输出功率、填充因子、光照特性等基本特性。     

栉孔扇贝外套膜表皮细胞的分泌方式

采用组织学和电镜细胞化学方法,对人工养殖的3龄栉孔扇贝(Chlamysfarreri)外套膜表皮细胞的分泌方式进行了研究.结果表明,栉孔扇贝外套膜表皮细胞的分泌方式有局部分泌、顶浆分泌和全浆分泌.内表皮细胞以局部分泌和顶浆分泌为主,外表皮细胞以顶浆分泌和全浆分泌为主,生壳突起、感觉突起和缘膜突起上皮细胞均以顶浆分泌为主.表皮细胞中的髓性过氧化物酶(MPO)和酸性磷酸酶(ACP)均可通过局部分泌和顶浆分泌方式排到体表.     

Stochastic Modelling of Multiple Random Genetic Mutations Under the Cancer Stem Cell Hypothesis

The probability distribution for the size of each of the various cancer cell subpopulations created by random genetic mutations is expressed in the case of non-exponential growth of cancer and in the case of a heterogeneous tumor cell population.     

Facilitating Redundancy‐Oriented Management with Gene‐Therapy‐Oriented Management Against Disaster

This article tests the hypothesis that “if redundancy‐oriented management has negative aspects, then it could be facilitated by gene‐therapy‐oriented management.” Negative aspects include disadvantages, misjudgments, or miscalculations. The article provides a newly revised principle of disaster management by studying gene‐therapy‐oriented management. Based on qualitative analysis, redundancy‐oriented and gene‐therapy‐oriented management are analyzed via five variables: governments, business, volunteers, households, and the international community. The article is valuable because an analytical frame on gene‐therapy‐oriented management is systematically reconceptualized for the field of disaster management via three elements: unhealthy proteins (problems or failed measures), a vector (new or modified solutions), and target cells (positive outcomes). In accepting the hypothesis, the key tenet is that stakeholders have to assist the progress of redundancy‐oriented management with gene‐therapy‐oriented management by paying attention to the genes of each disaster.     

Exact inference in contingency tables via stochastic approximation Monte Carlo

Monte Carlo methods for the exact inference have received much attention recently in complete or incomplete contingency table analysis. However, conventional Markov chain Monte Carlo, such as the Metropolis–Hastings algorithm, and importance sampling methods sometimes generate the poor performance by failing to produce valid tables. In this paper, we apply an adaptive Monte Carlo algorithm, the stochastic approximation Monte Carlo algorithm (SAMC; Liang, Liu, & Carroll, 2007), to the exact test of the goodness-of-fit of the model in complete or incomplete contingency tables containing some structural zero cells. The numerical results are in favor of our method in terms of quality of estimates.     

人肾微血管内皮细胞转分化在移植肾间质纤维化形成中的作用

目的:探讨人肾微血管内皮细胞-间充质细胞转分化(endothelial-mesenchymal transition,EndMT)在移植肾间质纤维化形成中的意义及相关机制?方法:通过对南京医科大学第一附属医院25例慢性移植肾失功能(chronic allograft dysfunction,CAD)患者和25例正常人血生化指标进行分析,对移植肾组织标本和正常肾组织标本进行糖原(PAS)和马松三色(Masson)染色检查分析,观察两组肾功能?肾小管萎缩?肾小球塌陷及肾间质纤维化程度的差异?用免疫组织化学和间接免疫荧光双重染色方法检测两组肾组织标本中血管内皮细胞标志物CD34和肌成纤维细胞标志物α-平滑肌细胞肌动蛋白(α-smooth muscle actin,α-SMA)以及转化生长因子-β1(transforming growth factor-β1,TGF-β1)的表达和分布特点?进一步以原代人脐静脉内皮细胞(human umbilical vein endothelial cells,HUVECs)为体外研究对象,以TGF-β1(5 ng/ml)作用0~72 h,采用免疫印迹方法观察细胞中CD34和α-SMA的表达变化?结果:与正常人相比,CAD患者血清肌酐水平明显升高,PAS和Masson三色染色结果显示CAD患者移植肾组织中出现明显肾小管萎缩?肾小球塌陷及肾间质纤维化改变;半定量统计分析结果表明两者间存在统计学差异(P < 0.01)?免疫组织化学及间接免疫荧光染色结果表明,与正常组相比,CAD组中CD34阳性表达率降低而α-SMA及TGF-β1阳性表达率显著升高,CAD组中部分肾小球和间质微血管内皮细胞呈CD34和α-SMA双重染色阳性?体外研究显示,TGF-β1作用于HUVECs细胞后,随着时间延长,CD34表达逐渐降低而α-SMA表达逐渐增多,与对照组相比,具有统计学差异(P < 0.01)?结论:人肾微血管内皮细胞可能在TGF-β1介导下通过发生EndMT现象进而在移植肾间质纤维化形成中起重要作用?