溶液中pH对蛋白质乳化能力影响的拉曼光谱研究

本工作采用 FT- Raman光谱仪对不同的 p H值的蛋白质水溶液多次扫描 ,采用酰胺 带的谱图作曲线拟合 ,并以子峰面积表征对应二级结构含量 ,得出二级结构的变化与蛋白质水溶液与乙酸丁酯混合后乳化能力变化的关系。结果表明 :蛋白质分子对 p H变化的敏感程度不一样。蛋白质分子结构的改变是引起蛋白质水溶液在有机溶液中乳化的一个重要因素     

单链核糖体失活蛋白的Raman和红外光谱

我们测定了两种单链核糖体失活蛋白(肥皂草素和天花粉蛋白)的FTIR和FTRaman光谱。利用FTIR光谱酰胺Ⅲ区域对蛋白质的二级结构进行定量分析,计算了各种二级结构的含量。从肥皂草素和天花粉蛋白的二级结构分析可见,二者在结构上具有某种相似性,为二者功能上的相似性提供了依据。     

表面增强拉曼光谱对于蛋白质二级结构的酰胺III谱带表征

本文利用斜角沉积法制备银纳米棒阵列基底用于蛋白质二级结构的检测,结合酰胺Ⅲ谱带光谱分析,建立了一种基于表面增强拉曼光谱(SERS)蛋白质二级结构的表征方法.用这种方法获得了两种典型蛋白质(溶菌酶和细胞色素C)的SERS信号.通过分析蛋白质骨架酰胺Ⅲ的光谱,研究了浓度对蛋白质折叠状态的影响.结果表明在一定范围内随着浓度的增加,溶菌酶的α-螺旋结构和β-折叠结构成分增加,而细胞色素C的二级结构基本保持不变.     

表面增强拉曼光谱对于蛋白质二级结构的酰胺Ⅲ谱带表征（英文）

本文利用斜角沉积法制备银纳米棒阵列基底用于蛋白质二级结构的检测,结合酰胺Ⅲ谱带光谱分析,建立了一种基于表面增强拉曼光谱(SERS)蛋白质二级结构的表征方法.用这种方法获得了两种典型蛋白质(溶菌酶和细胞色素C)的SERS信号.通过分析蛋白质骨架酰胺Ⅲ的光谱,研究了浓度对蛋白质折叠状态的影响.结果表明在一定范围内随着浓度的增加,溶菌酶的α-螺旋结构和β-折叠结构成分增加,而细胞色素C的二级结构基本保持不变.     

FTIR用于变性蛋白质二级结构的研究进展

蛋白质是最重要的生命物质之一,有关蛋白质的各类研究也是人们比较感兴趣的课题。蛋白质的二级结构在维持蛋白质生理活性过程中发挥着重要的作用。随着科技的发展和研究方法的改进,对变性蛋白质微观结构的研究也越来越深入。近年来,国内外学者利用各种物理和化学方法对其作了大量的工作,而傅里叶红外光谱法(FTIR)以其独特的优越性,在研究蛋白质二级结构中发挥着不可替代的作用。文章就这方面的研究进行了初步概述,重点介绍了变性蛋白质二级结构的红外光谱学研究内容、谱学特点及其分析方法的研究进展。     

Micro－FTIR法研究肺癌细胞组织内蛋白质二级结构

采用Ｍｉｃｒｏ－ＦＴＩＲ法研究了不同程度的肺癌细胞组织内蛋白质二级结构的变化，获得了肺癌的恶性程度与表征蛋白质二级结构的α螺旋与β折叠两者之比值的关系。     

蛋白质二级结构的二维红外相关光谱模拟研究

利用Voigt函数模拟了蛋白质二级结构的红外光谱吸收带和酰胺I带,其中1680cm-1吸收峰被严重叠加。为了研究二维红外相关光谱分析技术对叠加峰的分辨能力,选取1680cm-1吸收峰作为研究对象。当1680cm-1单峰峰高发生变化时,其同步谱中自相关峰能准确的反映出来。当1680cm-1和1640cm-1双峰峰高都发生变化时,其同步谱中自相关峰不但能准确反映出这两个峰的变化,还能获得1680cm-1子峰对外部扰动的灵敏度高于1640cm-1子峰的信息。它们同步谱中负交叉峰说明了1680cm-1和1640cm-1的变化取向相反,异步谱中该位置的负交叉峰说明了1640cm-1的变化快于1680cm-1。二维相关分析的结果和模拟吸收带假设的变化情况一致。研究表明二维红外相关光谱技术具有高分辨率、高灵敏度等优点,可以用于研究严重叠加的酰胺I带,获取蛋白质二级结构变化的相关信息。     

Micro—FTIR法研究肺癌细胞组织内蛋白质二级结构

采用Ｍｉｃｒｏ－ＦＴＩＲ法研究了不同程度的肺癌细胞组织内蛋白质二级结构的变化，获得了肺癌的恶性程度与表征蛋白质二级结构的ａ螺旋与β折叠两者之比值的关系。     

莲子蛋白组分二级结构的研究

对莲子蛋白质进行了Osborne蛋白质分类。采用傅里叶变换红外光谱(FTIR)对清蛋白、球蛋白、醇溶蛋白和谷蛋白进行二级结构分析。应用去卷积和曲线拟合方法对四种蛋白组分的酰胺Ⅰ和Ⅲ带进行分析,清蛋白和球蛋白之间以及醇溶蛋白和谷蛋白之间各相应子峰峰位和二级结构峰面积百分比差异较小,但前两者各相应子峰峰位与后两者略有差异;而前两者各相应二级结构峰面积百分比与后两者有较大差异,特别是前两者的各相应有序结构(α-螺旋+β-折叠)峰面积的百分比明显大于后两者。用0.1 mol.L-1NaCl溶液提取的球蛋白和清蛋白有序结构含量均在55%左右,而醇或碱提的醇溶蛋白和谷蛋白的有序结构含量仅为40%左右,盐提的蛋白质二级结构有序性和稳定性更高。     

羟基磷灰石-碳酸钙-BSA水溶性复合物中蛋白质微观结构的研究

利用傅里叶变换红外光谱，结合二阶导数谱、退卷、积和曲线拟合等计算机解析方法，对牛血清白蛋白（BSA）－羟基磷灰灰石－碳酸钙水溶性复合物中BSA的二级结构进行了研究。结果表明，BSA的α－螺旋结构的含量增加，蛋白质结构趋于有序化；紫外光谱和紫外二阶导数谱的研究发现，BSA的芳香族氨基酸残基的微环境受到扰动，在生物体内，正是蛋白质结构的这些变化导致生物矿化过程的发生和进行。     

Self-organization of five species in a cyclic competition game

Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.     

Experimental study on downstep in Chinese intonation

Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.     

Contrastive analysis on tone between Putonghua and Taiwan Mandarin

The differences of the pitch and duration of Chinese syllables between Putonghua （PTH） and Taiwan Mandarin （TM） were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that： For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.     

Abelian-Higgs phase of SU(2) QCD and glueball energy

It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].     

Signal generation in an isotropic medium in scanning electron acoustic microscope

Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122： 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM （Scanning Electron Acoustic Microscopy） signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α （α is the radius of the focused electron beam）. Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.     

High efficiency filtering using two-dimensional photonic crystal coupled cavity structures

Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.     

Real-time restoration of rotational blurred image using gradient-loading

The key to the restoration of rotational motion blurred image is how to restore the image under a low cost and to correct the irreversibility of the degradation function matrix.Based on the special qualities of degradation function matrix and precise deduction in space-domain, we present a new approach using gradient-loading for restoration of rotational blurred image.By easily adding a gradient operator, the irreversibility of the original matrix is corrected and can be applied for inverse filtering then.Gradientloading is the optimized approach which combines the advantages of both the approaches using constrained least square filtering and traditional diagonal-loading.Compared with the approach using least square filtering, its peak signal-to-noise ratio (PSNR) is improved from 3.18 to 6.46dB, while the computing time is reduced to 1/2-1/3.Experimental results demonstrate the effectiveness, noise-resistibility, robustness, and low complexity of this approach, which make it more suitable for real-time environment.     

All-Optical Logic Device Using Bent Nonlinear Tapered Y-Junction Waveguide Structure

We propose an all-optical logic device made of a bent tapered Y-junction waveguide with a Kerr-type nonlinear interface. It could provide an AND gate, OR gate, and exclusive-OR (XOR) gate. We could obtain different transmission results by adjusting the bending angle. The numerical simulation results show that the device functions as AND, OR, and XOR gates.     

Real-time, continuous-wave terahertz imaging by a pyroelectric camera

Real-time, continuous-wave terahertz (THz) imaging is demonstrated. A 1.89-THz optically-pumped farinfrared laser is used as the illumination source, and a 124 × 124 element room-temperature pyroelectric camera is adopted as the detector. With this setup, THz images through various wrapping materials are shown. The results show that this imaging system has the potential applications in real-time mail and security inspection.