Energy landscape analysis for regulatory RNA finding using scalable distributed cyberinfrastructure

We investigate the folding energy landscape for a given RNA sequence through Boltzmann ensemble (BE) sampling of RNA secondary structures. The ensemble of sampled structures is used to derive distributions of energies and base‐pair distances between two configurations. We identify structural features that can be utilized for RNA gene finding. Characterization of the EL through BE sampling of secondary structures is computationally demanding and has multiple heterogeneous stages. We develop the Distributed Adaptive Runtime Environment to effectively address the computational requirements. Distributed Adaptive Runtime Environment is built upon an extensible and interoperable pilot‐job and supports the concurrent execution of a broad range of task sizes across a range of infrastructure. It is used to investigate two RNA systems of different sizes, S‐adenosyl methionine (SAM) binding RNA sequences known as SAM‐I riboswitches, and the S gene of the bovine corona virus RNA genome. We demonstrate how the implementation lowers the total time to solution for increases in RNA length, the number of sequences investigated, and the number of sampled structures. The distributions of energies and base‐pair distances reveal variations in folding dynamics and pathways among the SAM riboswitch sequences. Our results for BCoV RNA genome sequences also indicate sensitivity of folding to coding‐neutral variations in sequence. We search for a characteristic motif from within the SAM‐I consensus structure – a four‐way junction, among BE sampled structures for all 2910 SAM‐I sequences identified from Rfam (the curated ncRNA family database). We find that BE sampling provides insight into the variations in conformational distribution among sequences of the same ncRNA family. Therefore, BE sampling of secondary structures is a viable pre‐processing or post‐processing tool to complement comparative sequence analysis. The understanding gained shows how appropriately designed cyberinfrastructure can provide new insight into RNA folding and structure formation. Copyright © 2011 John Wiley & Sons, Ltd.     

灰树花子实体多糖的结构特性分析及提高小鼠的运动耐力

探究灰树花子实体多糖（GFP）的结构特性,同时考察其对小鼠运动耐力的影响,为后续灰树花多糖的深入研究提供参考。通过超声波、水提醇沉法获得灰树花粗多糖,采用DE-52纤维素柱和Sephadex G-100进行分离纯化,在扫描电镜下观察多糖的形貌特征,高效凝胶渗透色谱分析多糖的分子量,红外光谱分析多糖糖苷键构型,高效液相色谱测定多糖的单糖组成。构建小鼠力竭游泳和转棒疲劳实验模型,通过测定小鼠体内肝糖原（Hepatic Glycogen,HG）、肌糖原（Muscle Glycogen,MG）及血清生化指标,考察多糖对小鼠运动耐力的作用。结果表明,GFP纯化后分离得到3个多糖组分,GFP-A1的占比最大,得率为62.98%,其重均分子量为18 374 u,异头碳为α构型,由鼠李糖、葡萄糖、半乳糖、岩藻糖组成,摩尔比为1:10.52:11.38:18.67。小鼠的动物实验结果显示,与CK组相比,GFP-A1低、中、高剂量组的小鼠力竭游泳时间和转棒疲劳时间均显著提高（P<0.05）,HG、MG含量和超氧化物歧化酶（Superoxide Dismutase,SOD）活性同样显著增加（P<0.05）,血乳酸（Blood Lactic Acid,BLA）、血尿素氮（Blood Urea Ntrogen,BUN）、丙二醛（Malondialdehyde,MDA）含量则显著降低（P<0.05）,表明GFP-A1可以显著提高小鼠的运动耐力,且呈剂量依赖关系。结果表明,从灰树花子实体中提取的GFP-A1具有明显提高小鼠运动耐力的作用,该研究为灰树花多糖在运动食品领域上的开发应用提供了理论依据,具有广阔的应用前景。     

一种糊盒机自动施胶附加机构

为解决DH-58E高速自动糊盒机胶斗容量小、高速施胶过程中操作员添加胶黏剂次数多的问题,降低糊盒废品率,设计了一款糊盒机自动施胶附加机构。在糊盒前的输送部位安装一个储胶胶仓,不仅增加了容胶量,而且还可以控制胶斗内的胶黏剂含量。该附加机构避免了因施胶轮淹入胶液过浅或过深造成的产品报废问题,其有效性在实际使用中得到了验证。     

Binding of vitamin A with milk α- and β-caseins

The binding sites of retinol and retinoic acid with milk α- and β-caseins were determined, using constant protein concentration and various retinoid contents. FTIR, UV–visible and fluorescence spectroscopic methods as well as molecular modelling were used to analyse retinol and retinoic acid binding sites, the binding constant and the effect of retinoid complexation on the stability and conformation of caseins. Structural analysis showed that retinoids bind caseins via both hydrophilic and hydrophobic contacts with overall binding constants of K_{retinol-α-caseins} = 1.21 (±0.4) × 10⁵ M⁻¹ and K_{retinol-β-caseins} = 1.11 (±0.5) × 10⁵ M⁻¹ and K_{retinoic acid-α-caseins} = 6.2 (±0.6) × 10⁴ M⁻¹ and K_{retinoic acid-β-caseins} = 6.3 (±0.6) × 10⁴ M⁻¹. The number of bound retinol molecules per protein (n) was 1.5 (±0.1) for α-casein and 1.0 (±0.1) for β-casein, while 1 molecule of retinoic acid was bound in the α- and β-casein complexes. Molecular modelling showed different binding sites for retinol and retinoic acid on α- and β-caseins with more stable complexes formed with α-casein. Retinoid–casein complexation induced minor alterations of protein conformation. Caseins might act as carriers for transportation of retinoids to target molecules.     

微波预处理压榨茶叶籽油及其氧化稳定性

采用微波预处理压榨法提取茶叶籽油,与烘烤后压榨法在提取率、理化性质和氧化稳定性进行了比较.结果表明,微波预处理压榨茶叶籽油得率比120℃烘烤后压榨得油率高9.6％,为21.81％,油脂提取率为77.5％;微波预处理压榨茶叶籽油的理化性质与60、80℃烘烤后压榨茶叶籽油无明显差异;微波预处理压榨茶叶籽油氧化稳定性高于60℃烘烤后压榨的茶叶籽油,适当升高烘烤温度,压榨茶叶籽油的氧化稳定性升高,当烘烤温度达到120℃时,其氧化稳定性下降.     

NMR等仪器分析技术在鉴定生物活性分子构型中的应用

核磁共振技术(NMR)在化学、生物医药领域是一种极为重要的检测手段。本文综述了NMR和圆二色谱技术在鉴定生物活性分子构型中的应用,提出了一些问题和其适用范围。并对NMR等仪器分析技术在鉴定生物分子构型的研究进行了展望。     

空间凸轮-螺旋组合式折叠翼面展开机构设计及其运动特性分析

提出新型空间凸轮—螺旋组合式折叠翼面展开机构,分析其工作原理,确定其相关技术参数。基于解析法与反转法,对折叠翼面展开机构的功能执行部件———空间圆柱凸轮机构进行了运动规律设计和包括凸轮槽道廓线、压力角及廓线曲率半径的设计,建立了折叠翼面展开机构展开运动学理论模型并进行了求解,结果证明折叠翼面展开机构符合设计要求,其运动规律设计正确。     

大型纸机使用复合打浆酶改善铜版纸折页爆裂

随着国内数台大型铜版纸机的投产,铜版纸市场日渐疲软,如何提高铜版纸的质量成为各大企业关注的焦点。铜版纸印刷后的折页爆裂问题是束缚铜版纸质量提高的一大障碍。太阳纸业大型铜版纸纸机通过使用提高成纸强度的打浆酶改善了铜版纸印刷后的折页爆裂问题,取得了较好的效果。