粘性嗜热链球菌ST-1产胞外多糖发酵条件优化

应用响应面法对一株粘性嗜热链球菌ST-1的产胞外多糖的发酵条件进行了优化.根据单因素的实验结果,选取接种量,发酵温度,发酵时间作为考察因素,以胞外多糖的产量作为响应值,利用Box-Behnken实验设计方法,建立了胞外多糖产量与三个考察因素之间的回归方程并得到最佳发酵条件为:接种量5%,发酵时间14 h,发酵温度42℃...     

根癌农杆菌介导转化红曲菌及转化子发酵性能的研究

利用根癌农杆菌介导转化技术成功将潮霉素抗性基因转入发白红曲菌中,优化了抗生素浓度,发白红曲菌孢子浓度,根癌农杆菌浓度,共培养温度及时间,以及乙酰丁香酮浓度等转化条件,最终转化效率可达52个转化子/105个红曲孢子.将转化子在含有潮霉素B的培养基继代培养5代,得到了多株稳定的转化子,对部分转化子进行PCR鉴定,结果进一步...     

Autopoiesis and Interpretive Semiosis

Translation has long been viewed as ‘code-switching’ either within or between languages. Hence, most translation discussions center on its linguistic and cultural aspects. However, the fundamental mechanism of ‘translation as interpretative semiosis’ has yet to be studied with appropriate rigor. Susan Petrilli (2008) has identified ‘iconicity’ as the key that enables translative semiosis. Nevertheless, as her model is restricted to a discussion of literary translation activity in verbal sign systems, a fundamental mechanism to explain translation as interpretative semiosis is still needed. By analyzing the interactions between the source sign (the translated) and the target sign (the translatant) in the translating process, it can be discerned that Humberto Maturana’s notion of autopoiesis may provide some crucial insights into translative semiosis. By identifying the autopoietic nature of translation, that is, the interlocked structural coupling between the Translated and Translatant, translation is no longer the ‘one-to-one-correspondence’ between sign systems, but rather a recursive process of interpretation—an interpretive semiosis. Moreover, it is by this autopoietic, self-productive mechanism of translation that I would suggest translation becomes a recursive generation of new inter-connections between semiotics systems.     

Correlation between tissue oxygenation and erythrocytes elasticity

In this paper, near‐infrared spectroscopy (NIRS) and jumping optical tweezers were used to measure the tissue oxygenation and the elasticity of erythrocytes, respectively. The correlation between tissue oxygenation induced by arterial occlusion test (AOT) and the mechanical properties of individual erythrocytes from a blood sample obtained after AOT was studied. The experimental results show a linear correlation between the oxygenation signal caused by AOT and the elasticity of erythrocytes. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Physiological and proteomic analysis of young rice leaves grown under nitrogen-starvation conditions

Rice grown in anaerobic waterlogged soil accumulates ammonium as a major source of nitrogen (N). We have compared the physiological symptoms of rice seedlings subjected to N-starvation stress with those receiving sufficient N, based on measurements of shoot/root length and weight and an analysis of protein expression patterns. N starvation marginally increased root growth but notably decreased shoot biomass. N uptake was reduced by >50% in the roots and shoots of N-starved seedlings. To better understand the mechanism of N starvation in rice, we performed a comparative proteome analysis of proteins isolated from rice leaves. Twenty-five differentially expressed proteins were analyzed by matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry and electron spray ionization quadrupole TOF. Functional analysis of the N-starvation response proteins suggested their involvement in protein synthesis and fate, metabolism, and defense. These results indicate that these proteins may play important roles in regulating the plant’s complex adaptation responses for N use during N starvation. The proteins may be useful for further characterization of protein function in plant N nutrition.