Effects of osmotic stress on antioxidant enzymes activities in leaf discs of P<Subscript>SAG12</Subscript>-<Emphasis Type="Italic">IPT</Emphasis> modified gerbera

Leaf senescence is often caused by water deficit and the chimeric gene PSA612-1PT is an auto-regulated gene delaying leaf senescence. Using in vitro leaf discs culture system, the changes of contents of chlorophylls, carotenoids, soluble protein and thiobarbituric acid reactive substance （TBARS） and antioxidant enzymes activities were investigated during leaf senescence of PSA612-1PT modified gerbera induced by osmotic stress compared with the control plant （wild type）. Leaf discs were incubated in 20%, 40% （w/v） polyethylene glycol （PEG） 6 000 nutrient solution for 20 h under continuous light [ 130 μmol/（m^2·s）]. The results showed that the contents of chlorophylls, carotenoids and soluble protein were decreased by osmotic stress with the decrease being more pronounced at 40% PEG, but that, at the same PEG concentration the decrease in the transgenic plants was significantly lower than that in the control plant. The activities of superoxide dismutase （SOD）, catalases （CAT）, ascorbate peroxidase （APX）, guaiacol peroxidase （GPX） and dehydroascorbate reductase （DHAR） were stimulated by PEG treatment. However, the increases were higher in PSA612-IPT transgenic plants than in the control plants, particularly at 40% PEG treatment. Lipid peroxidation （TBARS content） was increased by PEG treatment with the increase being much lower in transgenic plant than in the control plant. It could be concluded that the increases in the activities ofantioxidant enzymes including SOD, CAT, APX, GPX and DHAR were responsible for the delay of leaf senescence induced by osmotic stress.     

补充谷氨酰胺及大强度训练对赛艇运动员细胞免疫机能影响的研究

目的观察8w大强度训练和补充谷氨酰胺对细胞免疫机能的影响,以期为赛艇运动员免疫机能的研究提供参考资料。方法采集陕西省赛艇队公开级二线16名男性运动员实验前后晨安静时静脉血5ml测T淋巴细胞亚群和IL-2。结果H组（谷氨酰胺＋大强度训练组）和C组（大强度训练组）运动员8周大强度训练后IL-2较自身安静时都降低,服用谷氨酰胺组（H组）外周血IL-2下降17．9％（P〉0．05）;C组下降48．5％（P〈0．001）;实验后H组CD3^＋无显著性变化,CD4^_上升7．6％（P〉0．05）,CD8^＋下降16．6％（P〈0．05）,CD4^＋／CD8^＋比值升高17．3％（P〈0．05）;C组CD3^＋下降（p〈0．05）,CD4^＋下降20．6％（P〈0．05）,CD8^＋无明显变化,CD4^＋／CD8^＋比值下降21．0％（P〈0．05）。结论8周大强度训练明显抑制赛艇运动员机体细胞免疫功能,补充谷氨酰胺8w可以提高赛艇运动员细胞免疫功能。     

城市公交车对双车道混合交通流的影响

城市道路上的车流主要是公交车和小汽车混合流,而一般交通流理论都是以小汽车流为对象进行研究和建模。基于运动波理论和线性元胞自动机模型,本文提出了一种宏观与微观空间表现尺度相结合的双车道混合交通流组合建模方法分析。     

基于细胞神经网络混沌特性的图像加密技术应用研究

基于细胞神经网络(Cellular Neural Networks)的数字图像加密算法,利用细胞神经网络独有特性,构造一个五维的混沌序列作为秘钥源,在此基础上利用Logistic混沌序列图像像素置乱算法,从而实现对图像加密.编程模拟仿真实验表明,加密图像置乱度高,相邻像素的相关性小,抗攻击性强,安全性更高.最后对明文和密文进行相关性分析,从理论上验证了该加密算法的可靠性.     

Current status,enablers ＆ barriers of implementing cellular manufacturing system in Indian industries

The cellular manufacturing （CM） has been proved as a well-known manufacturing strategy that helps to improve manufacturing efficiency and productivity by utilizing the philosophy of group technology. Large num- ber of papers has been published in the area of design issues of CM system. Unfortunately, the issues related to acceptability of CM in Indian industries are typically not examined rigorously as technical issues. This paper pre- sents the results of a survey carded out to find the status, enabler and barrier of implementing CM system in Indian industries.     

Effect on growth and productivity of lutein from the chlorophyta microalga,strain MCH of Muriellopsis sp., when grown in sea water and outdoor conditions at the Atacama Desert

BackgroundMicroalgae are microorganisms that produce various products, for example, pigments, mainly carotenoids. This study aimed to used the strain of Muriellopsis sp. and to evaluate their behavior when grown in freshwater and seawater, along with indoor and outdoor conditions for both cultures. Growth of the strain was evaluated by determining its biomass, lutein productivity with high-performance liquid chromatography (HPLC), and antioxidant activity by using the 2,2-diphenyl-1-picrilhydrazil (DPPH method).ResultsMuriellopsis sp. strain in indoor cultures showed an increased antioxidant activity. In outdoor conditions, both cultures showed increased cells number, concentration of biomass, and lutein productivity. The percentage of lutein obtained from the strain MCH in indoor conditions was 25 times higher than that reported for calendula, reaching 0.75% of lutein in Muriellopsis sp. cultured in seawater, followed by 0.6% in Muriellopsis sp., cultures in freshwater at day 12 of both cultures. These values exceed that of microalgae Scenedesmus almeriensis, which reaches 0.53% lutein.ConclusionsThe results show that the native strain of the Atacama Desert is one of the largest producers of lutein as compared to those reported to date. The study demonstrated the feasibility of producing this carotenoid with well-known properties to prevent some diseases due to its high nutritional value. Muriellopsis sp. cultivation in open-air seawater is a good precedent for developing mass production of this species in an area where freshwater is scarce and costly.How to cite: Cruz-Balladares V, Marticorena P, Riquelme C. Effect on growth and productivity of lutein from the chlorophyta microalga, strain MCH of Muriellopsis sp., when grown in sea water and outdoor conditions at the Atacama Desert. Electron J Biotechnol 2021;54. https://doi.org/10.1016/j.ejbt.2021.09.001     

扩散系统的元胞自动机模拟

元胞自动机是一种时间、空间、状态都离散的动力学模型,是非线性科学的一种重要的研究方法。元胞自动机特别适合于复杂系统时空演化过程的动态模拟研究。元胞自动机提供一个虚拟的微观世界,能够在粗粒化程度上再现符合一般性规则的物理现象。用元胞自动机模拟两种物质的扩散过程,建立扩散系统的演化规则样本。     

Review:DNA-damage response network at the crossroads of cell-cycle checkpoints, cellular senescence and apoptosis

Tissue homeostasis requires a carefully-orchestrated balance between cell proliferation, cellular senescence and cell death. Cells proliferate through a cell cycle that is tightly regulated by cyclin-dependent kinase activities. Cellular senescence is a safeguard program limiting the proliferative competence of cells in living organisms. Apoptosis eliminates unwanted cells by the coordinated activity of gene products that regulate and effect cell death. The intimate link between the cell cycle, cellular senes- cence, apoptosis regulation, cancer development and tumor responses to cancer treatment has become eminently apparent. Extensive research on tumor suppressor genes, oncogenes, the cell cycle and apoptosis regulatory genes has revealed how the DNA damage-sensing and -signaling pathways, referred to as the DNA-damage response network, are tied to cell proliferation, cell-cycle arrest, cellular senescence and apoptosis. DNA-damage responses are complex, involving “sensor” proteins that sense the damage, and transmit signals to “transducer” proteins, which, in turn, convey the signals to numerous “effector” proteins implicated in specific cellular pathways, including DNA repair mechanisms, cell-cycle checkpoints, cellular senescence and apoptosis. The Bcl-2 family of proteins stands among the most crucial regulators of apoptosis and performs vital functions in deciding whether a cell will live or die after cancer chemotherapy and irradiation. In addition, several studies have now revealed that members of the Bcl-2 family also interface with the cell cycle, DNA repair/recombination and cellular senescence, effects that are generally distinct from their function in apoptosis. In this review, we report progress in understanding the molecular networks that regulate cell-cycle checkpoints, cellular senescence and apoptosis after DNA damage, and discuss the influence of some Bcl-2 family members on cell-cycle checkpoint regulation.     

基于核心素养的细胞的衰老与凋亡教学设计

以"细胞的衰老与凋亡"为例,通过创设问题情境、设置认知矛盾、小组讨论、社会话题探讨、迁移应用等活动,以知识为载体,传递正确的生命观念、严密的逻辑思维、严谨的科学探究精神、良好的社会责任感,培养学生的核心素养。     

基于GSM系统的基站子系统(BSS)部分研究

GSM是一个庞大、复杂的系统,从结构上来看主要包含4个主体:基站子系统(BSS)、移动交换子系统(MSS)、操作维护子系统(OMC)、移动台(MS)。BSS在GSM中实现无线和发射功能,是GSM系统实现无线通信的关键组成部分。本文介绍了BSS的组成及功能,以及它的操作维护平台OMCR。