麻疯树油：受青睐的生物柴油原料

2008—2009两年来暴涨暴跌的地沟油收购价让生产商们意识到，单纯依靠地沟油作为生物柴油的原料并非长久之计。一种耐干耐瘠植物——麻疯树（又称小油桐树、膏桐），正在击败大豆、菜籽、蓖麻、花生及餐饮回收废油等其他生物柴油原料，受到中外能源巨头青睐。麻疯树有很高的经济价值，可连续采摘果实长达30年，是世界上公认的生物能源树，其种仁是传统的肥皂及润滑油原料，     

Au/CeO_2催化剂储存失活性研究

采用沉积-沉淀法制备了2%(质量分数)Au/CeO_2催化剂,并用X射线衍射、投射电镜、X射线光电子能谱和程序升温还原等手段研究了纳米金催化剂在室温空气中存放和冰箱冷冻存放失活的机理。结果表明,冰箱冷冻储存更有利于抑制金纳米颗粒的长大,使催化剂保持更高的储存活性。纳米金催化剂储存失活是部分可逆的,导致其失活因素有两方面:(1)金纳米粒子的长大,导致不可逆失活;(2)表面吸附二氧化碳和水,可通过高温焙烧来恢复部分活性,属于可逆性失活。     

克劳斯催化剂失活的原因及特征

主要介绍了克劳斯催化剂在硫回收过程中的几种失活原因，包括硫沉积、硫酸盐化、碳沉积、热老化、水热老化、等，并简要提出控制克劳斯催化剂失活的措施及克劳斯催化剂失活后的特征。     

克劳斯催化剂失活的原因及特征

主要介绍了克劳斯催化剂在硫回收过程中的几种失活原因，包括硫沉积、硫酸盐化、碳沉积、热老化、水热老化、等，并简要提出控制克劳斯催化剂失活的措施及克劳斯催化剂失活后的特征。     

美国海军向建立生物燃料模型化工具注资

美国海军研究局已向威斯康星大学研究人员提供200万美元,资助其在建立生物燃料模型化工具的研究,以此作为其长期致力的使用交换能源研究的一部分,以此来减少对化石燃料的依赖性。使用生物燃料来为商用、军用车辆提供能量这一研究仍处于初期阶段,而且并不是所有的生物燃料成份是相同的。例如,在几次商用测试飞行中,波音客机已经使用了几种不同的生物燃料,其中一种的主要成份是食用油,另一种则是从麻疯树灌木种子中提取的植物油。     

单增李斯特菌生态行为模型构建及机制研究进展

目的 探究食品中的单增李斯特菌随食品链相关条件的变化而发生的"生长-失活-再生长"生态行为规律.方法 以热加工为失活条件,综述单增李斯特菌生态行为的影响因素、模型构建和相关机制.结果 单增李斯特菌在"生长-失活"过程中,细胞的历史生长条件会对其失活特性产生影响,在"失活-再生长"过程中,细胞的历史生理状态会影响其修复再生长的延滞期.结论 食品链中细菌的生长和失活是连续的过程,有必要研究在连续的环境条件变化过程中细胞的生态行为,以期为食品风险评估和食品安全防控提供支持.     

克劳斯催化剂失活的原因及特征

主要介绍了克劳斯催化剂在硫回收过程中的几种失活原因,包括硫沉积、硫酸盐化、碳沉积、热老化、水热老化、等,并简要提出控制克劳斯催化剂失活的措施及克劳斯催化剂失活后的特征。     

PS-Ti超滤膜反应器进行酶水解预处理的蔗渣和酶回收的研究

研究了膜式糖化反应器及酶回收的工艺过程首次提出了ＰＳ－Ｔｉ复合管式膜糖化器水解蔗渣喷爆物及循环使用纤维素酶的新工艺研究了水解酶失活的机理为非降解底物的吸附作用，即水解酶大部分失活是由于吸附于非降解的蔗渣上所致超滤与丹宁沉淀法结合，使水解酶回收率均大于９０％膜式糖化反应器的半连续操作的最高总转化率可达９７％，在２０ｈ内总转化率水平比间歇提高７倍，还原糖产率提高６倍水解液中葡萄糖与木糖的质量比为３∶１     

水稻中一种抗真菌蛋白的分离与特性分析

从萌发的水稻种子中分离并纯化了一种能抑制多种病原真菌生长的蛋白（简称为ＲＡＦＰＩ），在马铃薯葡糖琼脂培养基上，２０μｇＲＡＦＰＩ可明显抑制木霉（Ｔｒｉｃｈｏｄｅｒｍａｒｅｅｓｅｉ）菌丝的生长，此蛋白还具有较广的抗真菌菌谱，其分子量为１６．５９ＫＤ，等电点为８．７，组成成分中富含Ｐｒｏ、ＧｌＸ和Ａｓｘ，经测序得到了其Ｎ端２０个氨基酸序列。     

在线用微波透射型水分计

在线用微波透射型水分计冈田猛一、前言在茶叶加工中，一般是通过蒸发刚摘下的新叶使氧化酶失活以抑制发酵，并使水分保持在５轴一６ｑｏ以保持叶片原来的绿色，再经成形和干燥制成茶叶，所以加工过程中主要是干燥作业。在生产线上的质量管理和制造方法对产品价格有很大影...     

一种蛋白质纯化流程用于提纯大肠杆菌表达的蛋白片段

用一种新的蛋白质纯化流程提纯由大肠杆菌表达的夏氏疟原虫AMA1片段。大肠杆菌表达的片段首先用镍柱提纯，提纯后的蛋白用DTT还原，对盐酸胍透析，再对空气氧化。用RP－HPLC对片段二次提纯，通过冻干转换缓冲液。SDS－PAGE、RP－HPLC和质谱分析都显示，经这种纯化流程提纯的蛋白有很高的纯度，且二硫键已完全正确形成。提示这一蛋白质纯化流程可用于由大肠杆菌表达的低分子量寡二硫键的蛋白。     

重组鲈鱼生长激素的分离纯化及抗体制备

用IPTG诱导鲈鱼生长激素基因工程菌E.coli.RV308,使重组鲈鱼生长激素得以表达并分泌到周质空间,利用渗透休克法从菌液中提取间质蛋白,经DEAE-SepharoseCL-6B、矣丙烯酰胺凝胶电泳及SephadexG-75纯化后得到单一电泳纯的重组鲈鱼生长激素,并将此激素作为抗原制备抗体,可应用于鱼类血液中生长激素含量的测定。     

人体c-Mpl分子配体蛋白XP1的表达、纯化及活性初步鉴定

TPO是近年发现的血小板生成素，它通过与其受体c-Mpl的结合刺激巨核细胞的发生，调节动物或人体血小板的生成。利用酵母双杂交系统，以人体c-Mpl受体作为诱饵蛋白，我们从人体肝脏cDNA文库筛选到另一与c-Mpl相结合的新配体，命名为XP1。将：xpl-cDNA构建到pET-28b大肠杆菌融合表达载体，经金属离子亲和层析柱和DEAE阴离子层析柱分离纯化，获得纯度为99％的His-XPI水溶性融合蛋白。表达产物利用小鼠巨核细胞集落形成单位测定活性。结果表明：xpl基因在大肠杆菌中获得高效水溶性表达；其产物对小鼠骨髓细胞巨核细胞集落形成单位有明显的刺激作用。     

Molecular dynamics simulation of the nonlinear behavior of the CNT-reinforced calcium silicate hydrate (C–S–H) composite

Calcium–Silicate–Hydrate (C–S–H), which is the major constituent of the cement at the nanoscale, is responsible for the strength and fracture properties of concrete. This research is dedicated to the numerical study of enhanced mechanical properties of C–S–H reinforced by embedding carbon nanotube (CNT) in its molecular structure. Series of molecular dynamics (MD) simulations indicate that the tensile strength of CNT-reinforced C–S–H is substantially enhanced along the direction of CNT as compared to the pure C–S–H. The results of tensile loading reveal that CNT can efficiently bridge the two sides of cracked C–S–H. In addition, CNTs can severely intensify the “transversely isotropic” response of the CNT-reinforced C–S–H. Furthermore, the pull-out behavior of CNT reveals that the force-displacement response can be estimated by a bilinear model, which can later be used for simulation of cohesive crack propagation and multiscale simulation of crack bridging at macro scale specimen of CNT-reinforced cement.     

Molecular modelling of protein adsorption on the surface of titanium dioxide polymorphs

This paper reports a molecular modelling study of the adsorption of protein subdomains with unlike secondary structures on different surfaces of ceramic titanium dioxide (TiO(2)), forming a passivating film on titanium biomaterials that provides the interface between the bulk metal and the physiological environment, affecting its biocompatibility and performance. Using molecular dynamics methods, we study the effect of the nanoscale structure of the common TiO(2) polymorphs (rutile, anatase and brookite) on the adsorption of an albumin subdomain and on two connected fibronectin modules, respectively containing α-helices and β-sheets. We find that the larger protein subdomain shows a stronger adsorption, as expected because of its size, but also that the three surfaces behave differently. In particular, brookite shows the weakest adsorption, whereas anatase leads to the strongest intrinsic adsorption, in particular for the fibronectin modules. Moreover, the simulations indicate a significant conformational change of the adsorbed protein subdomains with extensive surface nanopatterning. These results show that classical molecular dynamics methods can provide useful information about the influence of nanostructure and topology on protein physisorption at a fixed surface chemistry.     

Identification of quantum dot bioconjugates and cellular protein co-localization by hybrid gel blotting

New approaches are needed to address the interaction of nanoparticles and cellular proteins at the molecular level. We present a modification of PAGE co-immunoprecipitation, QD-based PA-AGE electrophoresis blotting, and apply this to identify quantum dot (QD) bioconjugate-cellular protein association. This method provides the capability to isolate and evaluate the action of QD bioconjugate-protein complexes in intact cells and to correlate these identified interactions with their location in cells.     

Losing the expression of molecular chirality in self-assembled physisorbed monolayers

STM imaging on graphite of the S-enantiomer of a chiral diacetylene isophthalic acid derivative reveals that molecular chirality is not expressed in the monolayer due to a specific molecular conformation preventing the stereogenic center to transfer its chiral information.     

Combined approach to the analysis of recombinant protein drugs using hollow-fiber flow field-flow fractionation, mass spectrometry, and chemiluminescence detection

The impurities present in recombinant protein drugs produced by large-scale refolding processes can not only affect the product safety but also interact with the expressed protein. To relate the impurity profile to conformation and functionality of the protein drug, analytical methods able not to degrade the sample components should be preferred. In this work, an urate oxidase (uricase) drug from Aspergillus flavus expressed in Saccharomyces cerevisiae, and a reagent-grade uricase from Candida sphaerica expressed in Escherichia coli, are analyzed by combining hollow-fiber flow field-flow fractionation with matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI/TOFMS) and with chemiluminescence enzyme activity assay. Preliminary detection and identification of sample impurities is performed by means of conventional methods such as RP HPLC with electrospray ionization quadrupole-TOF MS and MALDI/TOFMS with SDS PAGE and 2D SDS PAGE. Results show that the recombinant uricase samples obtained from different microorganisms have different impurities and different enzymatic activity and that different uricase oligomers are present in solution.     

Integrated and ultrasensitive gel protein identification

An integrated gel protein identification technology is developed and demonstrated for the effective ( approximately 90% recovery), rapid (less than 5 min), and sensitive identification (as low as 1 ng gel protein loading) of gel-resolved proteins using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). This integrated technology involves on-line combination of electronic protein transfer with nanoscale proteolytic digestion in a capillary platform, enabling electrokinetic-based protein extraction and stacking, real-time proteolytic cleavage of extracted proteins, and direct deposition of protein digests onto MALDI targets. By revisiting the yeast two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) in similar isoelectric point and molecular mass ranges as studied by Gygi and co-workers (Gygi, S. P.; Corthals, G. L.; Zhang, Y.; Rochon, Y.; Aebersold, R. Proc. Natl. Acad. Sci. U.S.A. 2000, 97, 9390-9395), we are additionally able to identify a large number of low abundance proteins with codon adaptation index (CAI) values of <0.2 and increase the proteome coverage to nearly 50%. The CAI value distribution for identified yeast proteins now more closely approximates that predicted for the entire yeast proteome. We further note that the current single-capillary methodology can be easily expanded to a multiplexed capillary platform as a ultrahigh throughput and greatly effective tool for linking 2-D PAGE with MS, particularly for the analysis of low-abundance proteins.     

注塑充模聚合物流动形态与力学行为分子机制研究

以聚甲基丙烯酸甲酯(Polymeric methyl methaerylate,PMMA)为实验材料,基于分子动力学模拟实验研究了注塑成型聚合物充模流动与力学行为的分子机制.构建包含10条聚合度为20的无规PMMA分子链所构成的链团模型,基于能量最小化与SA算法实现了体系能量初始化;基于周期性边界,引入COMPASS从头算分子力场及Velocity-Verlet算法,实现了PMMA胞元在恒温平面流场中的流态与力学行为模拟实验.结果表明,PMMA充模与形变过程首先需要克服包含体系内能、分子链松弛与解缠在内的“活化能”,且存在时间和应力阈值,前者体现了瞬时加载内能协调效应,后者对应于高剪切力作用下分子松弛与解缠现象.体系C原子回转半径分布表明剪切力的作用使得高分子沿流场方向取向排布,剪切力越大则取向越明显,剪切力过大则分子链将断裂而弹性恢复.MSD结果揭示了熔态聚合物充模流动的实质是大分子链定向迁移和取向排布协调运动的结果,且进一步验证了“活化能”的存在,克服这一制约之后大分子链的迁移效应才变得明显,且迁移速率随剪切应力的增大呈非线性增大变化.