Generation of skeletal muscle cells from embryonic and induced pluripotent stem cells as an in vitro model and for therapy of muscular dystrophies

Muscular dystrophies (MDs) are a heterogeneous group of inherited disorders characterized by progressive muscle wasting and weakness likely associated with exhaustion of muscle regeneration potential. At present, no cures or efficacious treatments are available for these diseases, but cell transplantation could be a potential therapeutic strategy. Transplantation of myoblasts using satellite cells or other myogenic cell populations has been attempted to promote muscle regeneration, based on the hypothesis that the donor cells repopulate the muscle and contribute to its regeneration. Embryonic stem cells (ESCs) and more recently induced pluripotent stem cells (iPSCs) could generate an unlimited source of differentiated cell types, including myogenic cells. Here we review the literature regarding the generation of myogenic cells considering the main techniques employed to date to elicit efficient differentiation of human and murine ESCs or iPSCs into skeletal muscle. We also critically analyse the possibility of using these cellular populations as an alternative source of myogenic cells for cell therapy of MDs.     

Toxicities of soluble Al, Cu, and La include ruptures to rhizodermal and root cortical cells of cowpea

Elevated levels of many metals are toxic to plant roots, but their modes of action are not well understood. We investigated the toxicities of aluminium (Al), copper (Cu), and lanthanum (La) in solution on the growth and external morphology of 3-d-old cowpea (Vigna unguiculata L.) roots for periods of up to 48 h. Root elongation rate decreased by 50% at ca. 30 μM Al, 0.3 μM Cu, or 2.0 μM La, accompanied by a decrease in the distance from the root tip to the proximal lateral root. Kinks developed in some roots 2.0 ± 0.4 mm from the root apex on exposure to Al or La (but not Cu). Light and scanning electron microscopy showed that soluble Al, Cu, or La caused similar transverse ruptures to develop > 1 mm from the root apex through the breaking and separation of the rhizodermis and outer cortex from inner-layers. The metals differed, however, in the range in concentration at which they had this effect; developing in solutions containing 54 to‑600 μM Al, but only from 0.85 to 1.8 μM Cu or 2.0 to 5.5 μM La. These findings suggest that Al, Cu, and La bind to the walls of cells, causing increased cell wall rigidity and eventual cell rupturing of the rhizodermis and outer cortex in the elongating zone. We propose that this is a major toxic effect of Al, and that Cu and La also have additional toxic effects.     

Blackboard Mechanism Based Ant Colony Theory for Dynamic Deployment of Mobile Sensor Networks

A novel bionic swarm intelligence algorithm, called ant colony algorithm based on a blackboard mechanism, is proposed to solve the autonomy and dynamic deployment of mobiles sensor networks effectively. A blackboard mechanism is introduced into the system for making pheromone and completing the algorithm. Every node, which can be looked as an ant, makes one information zone in its memory for communicating with other nodes and leaves pheromone, which is created by ant itself in naalre. Then ant colony theory is used to find the optimization scheme for path planning and deployment of mobile Wireless Sensor Network （WSN）. We test the algorithm in a dynamic and unconfigurable environment. The results indicate that the algorithm can reduce the power consumption by 13% averagely, enhance the efficiency of path planning and deployment of mobile WSN by 15% averagely.     

生物乙烯研究进展

介绍了生物乙烯的背景和发展概况,总结了乙醇脱水反应的机理和所用的各类催化剂,分析了生物乙烯产业化中需要解决的关键技术问题,并指出发展生物乙烯有着光明的前景,对石油路线代替战略有着重要的意义.     

Effects of special brain area regional cerebral blood flow abnormal perfusion on learning and memory function and its molecular mechanism in rats

To study the effect of special brain area regional cerebral blood flow (rCBF) abnormal perfusion on learning and memory function and its molecular mechanism, 64 adult male healthy Sprague-Dawley (SD) rats were randomly divided into two groups, the false operation group (control group) and the operation group (model group). After surgical operation, the operation group undertook bilateral common carotid artery permanent ligation, while the other group did not. Learning and memory function were measured by Y-maze at 4 h, 8 h, 24 h and 3 d after surgical operation, respectively. The rCBF of the right frontal lobe and hippocampus was also detected by the PerifluxPF model laser Doppler flowmetry, and the expressions of c-fos or c-jun or Bcl-2 and Bax were also measured by immune histochemistry S-P method accordingly. Results showed that the rCBF of the right frontal lobe and hippocampus in the operation group was significantly lower than that in the false operation group (P < 0.05). The learning indexes, error number (EN), day of reach standard and total reaction time (TRT) in the operation group, were significantly higher than that in the false operation group (P < 0.05). However, the initiative evasion rate in the operation group was significantly lower than that in the false operation group. The study also found that the rCBF was relatively more, the indexes (EN, the day of reach standard and TRT) relatively fewer, but the initiative evasion rate and the memory keeping rate were relatively more. The positive expression and the average absorbency of Fos and Jun in the operation group were significantly higher than that in the false operation group (P < 0.05). Furthermore, Bax and Bcl-2 positive cells were all increased over time in the operation group, and the expression ratio of Bax/Bcl-2 in the operation group was significantly higher than that in the false operation group (P < 0.01). In conclusion, rCBF decrease can impair the learning and memory function in rats, which may be related to the increase of the expression ratio of c-fos or c-jun or Bcl-2 or Bax in the frontal cortex and hippocampus.     

共情脑机制的研究现状与展望

作为社会交往中的重要因素,共情是指理解并体验他人的情感和知觉感受的能力。目前的研究认为共情依赖于直接的投射机制而非逻辑推理。即观察到他人的情绪状态会涉及一部分处理自我情感的大脑结构的激活,该过程同时还会受到社会认知因素的调节。由于理解和间接体验他人痛觉的能力是维系社会纽带必不可少的,目前研究者越来越多地通过对痛觉共情的研究来揭示关于共情的普遍的神经机制。此外共情的动物模型、镜像神经元系统与共情的产生以及共情的调节等方向也将是研究的重点。     

植食性昆虫的寄主选择机理及行为调控策略

害虫是影响农作物生产的重要因素,过度使用化学农药已带来严重的“3R”问题。为了长期有效地控制害虫的危害,基于植食性昆虫寄主选择机制的行为调控策略已成为害虫治理研究的重要方向。天然植物资源（如驱避植物、诱集植物与诱集枝把）、物理模拟材料（如诱集色、驱避色与诱集模型）和人工合成物质（如引诱剂、驱避剂、刺激剂与抑制剂）等研发工作皆取得了突破性的进展。除单一措施的使用外,多种诱集措施协同利用的“诱集＋诱集”策略、诱集措施与趋避措施结合使用的“排斥-诱集”策略也已被广泛应用。     

体细胞直接转化为多能干细胞的新方法

胚胎干细胞具有自我复制、高度增殖、多向分化潜能、可植入性和重建能力等特征.对于诸如青少年糖尿病、帕金森综合症和心脏病等需要通过细胞移植来治疗的疾病而言,从人的囊胚内细胞团获得胚胎干细胞系是最理想的供体来源.然而,目前实验和医疗还要考虑到利用人类胚胎的一些伦理问题和组织排异反应.避免这些问题的可能途径就是通过已分化体细胞的重新编程来直接转化为诱导性多能干细胞,它们具有类似ES细胞的功能.目前,获得诱导性多能干细胞的设想已初步实现了从老鼠到人的突破.以下主要对体细胞直接转化为诱导性多能干细胞的研究现状、方法和转录因子在诱导体细胞重新编程中发挥的作用等内容进行了概述,以期为干细胞研究者进行更深入的研究提供一定的借鉴.     

白粉病菌侵染苦瓜的生理机制

对大顶苦瓜感染白粉病的发病过程和生理机制进行研究。结果发现,感病苦瓜叶片质膜透性与对照相比增加较少,其增加量与病情指数相关性不高;叶绿素a、b、总叶绿素、类胡萝卜素含量随病情加重均下降,接种15d,与对照比分别下降72.6%、68.5%、71.5%和27.1%,其中叶绿素a、b和总叶绿素含量变化与病情指数相关性很高,以叶绿素a含量变化相关性最高;氧化酶活性测定结果表明,感病苦瓜叶片中POD和PPO活性与对照比上升,且随感病时间延长活性增加更多,接种15d,POD和PPO活性较对照增加528.5%和70.4%,两个酶活性变化与病情指数的相关性也很高。     

湿地植物与丛枝菌根真菌(AMF)相互关系的研究进展

丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)是湿地植物主要共生菌之一,在湿地生态系统中具有重要的作用.本文就近年来AMF对湿地植物的营养物质吸收、生长发育、抗逆境胁迫和抗污染能力等的作用,湿地植物、水分、季节、土壤理化性质因素对根际AMF的多样性、侵染能力、空间分布、生长发育、孢子密度的影响,以及植物与AMF之间相互作用关系的研究进展进行综述.