Bone marrow cells adopt the phenotype of other cells by spontaneous cell fusion

Recent studies have demonstrated that transplanted bone marrow cells can turn into unexpected lineages including myocytes, hepatocytes, neurons and many others. A potential problem, however, is that reports discussing such 'transdifferentiation' in vivo tend to conclude donor origin of transdifferentiated cells on the basis of the existence of donor-specific genes such as Y-chromosome markers. Here we demonstrate that mouse bone marrow cells can fuse spontaneously with embryonic stem cells in culture in vitro that contains interleukin-3. Moreover, spontaneously fused bone marrow cells can subsequently adopt the phenotype of the recipient cells, which, without detailed genetic analysis, might be interpreted as 'dedifferentiation' or transdifferentiation.     

Restoration of normal function in genetically defective myotubes by spontaneous fusion with fibroblasts

Muscular dysgenesis in mice is a genetic disease of skeletal muscle caused by the recessive mutation mdg. Muscle fibres in affected mice are paralysed because of the failure of excitation-contraction coupling. Unlike normal myotubes in primary culture, dysgenic myotubes do not contract, either spontaneously or in response to electrical stimulation. The deficiency results from mutation of the gene for the skeletal muscle dihydropyridine receptor, an essential sarcolemmal component both of excitation-contraction coupling and of the slow calcium-ion channel. It has recently been shown that the addition of fibroblasts from normal (but not dysgenic) mice to cultures of dysgenic myotubes can restore spontaneous contractions in a small fraction of these myotubes, but the mechanism for this 'rescue' was not determined. In principle, if fibroblast nuclei were able to incorporate into myotubes, such nuclei could then supply the missing muscle-specific gene product. We have now investigated this possibility using nuclear, cytoplasmic and plasmalemmal markers. We report that the rescue to contractile ability in genetically paralysed dysgenic muscle is mediated by the previously unrecognized ability of fibroblasts to fuse spontaneously with developing myotubes.     

迁徙的城市和变迁的文化

全球化与中国文化的走向成为当今学术界的重要问题。从当代中国文化变迁中研究下列问题:现代性问题与文化危机,消费社会形态转型和媒介传播的结构,消费主义与日常生活,商品拜物教中的精神生态危机,大众传媒与世俗化问题。这些前沿学术问题的研究,对当代世界性的消费社会文化困境的揭示有着重要的意义。     

受证据理论启发的传感器数据融合算法

受证据理论的启发,提出了一种新的传感器数据融合算法.借鉴证据理论中的基本信任分配思想和证据组合思想,将所有测量值构成的集合视为辨识框架,并对各个测量值的精度进行判断,在此基础上将各个测量值分别转换为相应的证据;再利用基于冲突分配法的证据组合规则对所有证据进行组合,所得合成证据的Mass函数即为各个测量值的权值分配函数;...     

改变生态条件除藻方法的研究

根据食物链中Ｅｌｔｏｎｉａｎ金字塔的形态和Ｋａｌｋｗｉｔｚ提出的河流污染沿程变化分带的概念，提出了改变生态条件培养高一层次生物吃掉藻类的除藻方法，并在工艺上应用浮动生物滤清器解决了这一问题，取得了较好的除藻效果。     

近代翻译引起的汉语语言特征的变化

探讨近代翻译对汉语语言发展的影响,通过对鸦片战争后翻译文本以及其他文本语言特征的分析对比,观察翻译对汉语语言特征变化所产生的影响。     

技术进步、产出变动、要素投入改变与价值变动的关系

以马克思《资本论》中的价值构成公式为基础,将函数分析法与价值理论相结合,通过数学推导证明马克思在《资本论》相关章节中关于劳动生产率、产出、要素投入以及生活水平等因素变化时,价值总量、单位产出价值量和劳动力价值以及剩余价值的变动情况的论述的科学性,并进行了拓展,进一步分析了要素投入变化和生活水平变化时价值量的变动情况。     

Transplanted bone marrow regenerates liver by cell fusion

Results from several experimental systems suggest that cells from one tissue type can form other tissue types after transplantation. This could be due to the presence of multipotential or several types of adult stem cells in donor tissues, or alternatively, to fusion of donor and recipient cells. In a model of tyrosinaemia type I, mice with mutations in the fumarylacetoacetate hydrolase gene (Fah-/-) regain normal liver function after transplantation of Fah+/+ bone marrow cells, and form regenerating liver nodules with normal histology that express Fah. Here we show that these hepatic nodules contain more mutant than wild-type Fah alleles, and that their hepatocytes express both donor and host genes, consistent with polyploid genome formation by fusion of host and donor cells. Using bone marrow cells marked with integrated foamy virus vectors that express green fluorescent protein, we identify common proviral junctions in hepatic nodules and haematopoietic cells. We also show that the haematopoietic donor genome adopts a more hepatocyte-specific expression profile after cell fusion, as the wild-type Fah gene was activated and the pan-haematopoietic CD45 marker was no longer expressed.     

聚变反应中产生的α粒子的自举电流

本文对聚变产生的α粒子自举电流进行了研究,研究中采用了简便的Pade近似形式,同时考虑了回旋角散射效应和慢化过程中牵引作用的影响,给出了α粒子自举电流计算的理论表达式.采用ITER装置参数进行了数值计算,得到了α粒子自举电流的密度分布和大小,研究了影响自举电流大小的物理因素.结果表明α粒子自举电流随中心等离子体初始温度、密度和α粒子初始能量的增大而增大.结果表明α粒子自举电流较小,只占总自举电流的7%左右.     

臭氧氧化难降解废水生化性改变研究评述

将臭氧氧化难降解废水过程划分为生化性改变阶段和有机物去除阶段,并分析了近年来臭氧氧化废水生化性改变阶段的研究成果.发现在有机物去除率较低条件下,废水的污染物质含量,色度,UV254,SUVA和3维荧光光谱等指标变化显著,分析认为引起以上指标变化的原因是难降解有机物分解为小分子易降解有机物.生化性改变阶段废水中主要进行难降解有机物的分解反应,而非矿化反应.多位研究者GC-MC和分子量分布的实验结果表明,生化性改变阶段废水中小分子有机物种类和数量都明显增加.废水生化性指标和生化处理的相关研究报道进一步证明了生化性改变阶段废水生化性改善的事实.建议在今后研究中,以提高生化性改变阶段臭氧氧化反应效率为重点,破解难降解有机废水处理的难题.