柑橘皮渣废物利用发酵生产单细胞蛋白饲料

传统柑橘果实加工后剩下的大量柑橘皮往往被随意丢弃,对环境造成污染的同时也造成浪费。利用其中的纤维素及果胶类物质可以提供碳源生产单细胞蛋白,并提高其中关键氨基酸（苏氨酸、甲硫氨酸、赖氨酸）的产量,以及促进单细胞蛋白在作为饲料时的吸收效率。经单因素实验可使关键氨基酸的总产量最大:苏氨酸、甲硫氨酸、赖氨酸分别为2.03×10-3、3.58、1.49×10-2g/L,共3.60g/L,占总氨基酸14.77%,优化后的培养基为60g/L柑橘皮渣、21g/L尿素,接种量为20%（V/V）的混菌（黑曲霉∶啤酒酵母=1∶1）,最优发酵时间为5d。      

基于RGB图像特征的卷烟梗丝掺配比例检测

目的：建立一种基于RGB图像处理检测卷烟梗丝掺配比例的方法,优化卷烟掺配比例。方法：将叶丝和梗丝分别制成粉末后按不同比例混合均匀制成烟末,采用图像分析技术测定其RGB均值;通过梗丝比例与RGB均值回归分析,得到梗丝掺配比例与RGB 均值的函数模型,并对模型的准确性、精确性和重复性进行验证。结果：建立的梗丝掺配比例与RGB 均值多项式回归模型,模型拟合度较高,相关性系数R²为0.997 8;模型的准确性验证梗丝掺配比例与实际掺配比例的相对误差介于0.45%～3.04%,精确性检测变异系数为1.20%～1.86%,重复性检测变异系数为1.84%,均符合定量检测要求。结论：基于RGB图像处理法预测烟丝中梗丝掺配比例的方法,简单可行,与传统的人工挑选的方法相比更具科学性和准确性。     

食物致敏原表位定位技术的研究进展

食物致敏原是引起食物过敏的元凶,多为蛋白质.抗原表位是在抗原分子中与抗体反应或被抗原受体识别,并引发机体免疫应答的特殊化学基团.从表位水平认识食物致敏原,能揭示食物过敏的物质基础,为解决食物过敏问题提供精准的靶标.本文基于表位结构和定位方法的不同,介绍了食物致敏原表位定位技术的发展,并进一步展望了致敏原表位信息对于改进...     

Immunocytochemical localisation of para-coumaric acid and feruloyl-arabinose in the cell walls of maize stem

Two phenolic compounds, p-coumaric acid and feruloyl-arabinose, were localised by immunocytochemistry in the cell walls of the apical internode of two lines of maize (Co125 and W401) of different digestibility. The compounds were detected at two stages of cell maturity in the lignified tissues (sclerenchyma, fibres and xylem) and in the medullary parenchyma, which, in the samples studied, was not lignified. p-Coumaric acid is a phenolic acid associated with lignins, which confer resistance on plant cell walls to microbial degradation in the rumen. Feruloyl-arabinose is a compound associated with xylans, the principal hemicelluloses in Gramineae, which are potentially degradable. Labelling of p-coumaric acid decreased in both maize lines with cell age and as the cell walls became lignified. The mass of lignin deposited in the cell walls masked p-coumaric acid, thereby making it less accessible to the antibodies. There was an inverse relationship in the labelling of p-coumaric acid and feruloyl-arabinose. Feruloyl-arabinose was more heavily labelled as the plant cell walls matured in all the lignified tissues of both maize lines and in the parenchyma of the less digestible line. All tissues except the parenchyma were more heavily labelled with both sera in Co125, the more digestible line. © 1998 Society of Chemical Industry.     

Influence of Biodopants on PEDOT Biomaterial Polymers: Using QCM‐D to Characterize Polymer Interactions with Proteins and Living Cells

Organic conducting polymers (OCPs) are currently the subject of intense research in the area of biomaterials and bioelectronics. Of the OCPs, poly(3,4‐ethylenedioxythiophene) (PEDOT) has attracted significant interest, however there has been little work on investigating the incorporation of biological compounds as the dopant species in the polymer which are aimed at enhancing the biocompatibility and biofunctionality of the material. Here, we incorporate the biological dopants dextran sulphate, chondroitin sulphate, and alginate, into PEDOT polymers and investigate their influence on a suite of physicochemical and electrochemical properties. We employ QCM‐D to study the mass of adsorption and the viscoelastic properties of the important extracellular matrix proteins fibronectin and collagen. Furthermore, we use QCM‐D to study the adhesion of PC12 neural cells to the PEDOT‐biodopant polymers with and without an adsorbed protein conditioning layer. QCM‐D was found to be an excellent tool with which to study conducting polymer–biological interactions, with this report the first time that QCM‐D has been used to study cell interactions with conducting polymer biomaterials.     

螺旋藻细胞冷冻过程微尺度传热传质特性

为了探索保持螺旋藻活性的最佳冷冻条件,研究了冷冻过程凝固界面和螺旋藻细胞之间相互作用的物理现象,在考虑细胞和冰界面之间的耦合传热传质、膜的传输特性和凝固界面的移动过程的情况下,建立了螺旋藻细胞冷冻过程冰界面与细胞之间相互作用的数学模型,检查了螺旋藻细胞被冰界面包围过程的温度场和浓度场,研究了螺旋藻细胞被冰界面包围过程中细胞体积的收缩情况及影响因素.计算结果表明,膜的渗透性和冷却速率是影响细胞体积收缩的主要因素.该模型可优化减小螺旋藻细胞损伤的最佳冷冻条件.     

Neutral fitness landscapes in signalling networks

Biological and technological systems process information by means of cascades of signals. Be they interacting genes, spiking neurons or electronic transistors, information travels across these systems, producing, for each set of external conditions, an appropriate response. In technology, circuits performing specific complex tasks are designed by humans. In biology, however, design has to be ruled out, confronting us with the question of how these systems could have arisen by accumulation of small changes. The key factor is the genotype-phenotype map. With the exception of RNA folding, not much is known about the exact nature of this mapping. Here, we show that structure of the genotype-phenotype map of simple feed-forward circuits is very close to the ones found in RNA; they have a large degree of neutrality, by which a circuit can be completely rewired keeping its input-output function intact, and there is a relatively small neighbourhood of a given circuit containing almost all the phenotypes.     

Recent Progress of Counter Electrodes in Nanocrystalline Dye-sensitized Solar Cells

Dye-sensitized solar cell （DSC） consists a combination of several different materials： photoanodes with nanoparticulated semiconductors, sensitizers, electrolytes and counter electrodes （CEs）. Each materials performs specific task for the conversion of solar energy into electricity. The main function of CE is to transfer electrons to the redox electrolyte and regenerate iodide ion. The work of CE is mainly focused on the studies of the kinetic performance and stability of the traditional CEs to improve the overall efficiency of DSC, seeking novel design concepts or new materials. In this review, the development and research progress of different CE materials and their electrochemical performance, and the problems are discussed.