富勒烯碳-60,碳-70的电化学研究进展

短短的几年,随着各种物理与化学研究方法的相继介入,以C_(60)和C_(70)为代表的富勒烯研究取得了令人瞩目的成就。跟踪最新进展,引文41篇,本文就其电化学方面的研究工作做了系统的综述。

大分子物质的质谱研究

1. 利用解吸化学电离质谱(DCI-MS)，研究了C_(60)与烷基甲醚和伯醇自身化学电离(self-CI)产物之间的气相离子-分子反应，观察到加成离子[C_(60)C_2H_5O]~+和质子化分子[C_(60)H]~+是C_(60)与烷基甲醚等离子体反应的主要产物；相反，没有检测到C_(60)与伯醇离子体系形成的相应加成产物。利用AM1半经验方法对[C_(60)C_2H_5O]~+的十四种可能结构进行了计算。结果表明最稳定的加成产物是[3+2]环加成产物，并提出了该加成产物的形成途径。2. 使用同样方法研究了C_(60)与丙烯酸甲酯离子体系发生的气相离子-分子反应，观察到加成离子[C_(60)C_3H_3O]~+和质子化分子[C_(60)H]~+为主要产物。利用AM1半经验方法对[C_(60)C_3H_3O]~+的八种可能结构进行了计算，结果表明三种环加成产物为最稳定结构。3. 合成了一系列L7和σ因子肽片段，并利用基质辅助激光解吸电离质谱(MALDI-MS)、电喷雾质谱(ESI-MS)和圆二色(CD)对高效液相色谱(HPLC)提纯的合成肽进行了表征。4. 利用ESI-MS研究了L7和σ合成肽与蛋白质G和蛋白质A的复合物，发现了该复合物产生的最佳条件及其稳定性；并结合亲和色谱，证明了L7和σ合成肽与蛋白质G或蛋白质A形成的复合物是具有特异性的非共价复合物。5. 通过竞争酶联免疫吸附实验（ELISA）、亲和色谱和MALDI-MS的联用，发现L7和σ肽与IgG的Fc片断在蛋白质G和蛋白质A的结合位置不同。6. 利用鸡多克隆抗L7抗体通过免疫键合印迹法发现L7和σ肽之间没有交叉反应性。

模拟生物膜的电化学研究

本文简要评述了生物膜领域的发展过程及研究现状，介绍了关于生物膜的一些基本性质和理论。采用电化学方法对支撑双层磷脂膜（s-BLM）、杂化双层磷脂膜（HBM）、磷脂浇铸膜（Cast lipid film）等不同的模拟生物膜体系进行了研究。主要如果如下：1. 在玻碳（GC）电极表面制备了磷脂浇铸膜，并以此膜为生物膜的模型研究了多巴胺对NADH的催化氧化。多巴胺是通过将电极浸在多巴胺溶液中约10个小时，从而固定的磷脂膜内的。在pH = 7.0的磷酸缓冲溶液中获得了膜内多巴胺对NADH的催化氧化行为，发现氧化电流随着扫描圈数的增加而逐渐增大，并最终到达一个稳态，这是一个比较新的现象。同时，与NADH的裸玻碳电极上的电化学行为相比，其氧化过电位降低了约130 mV，2 × 10~（-3）mol/L的NADH的扩散系数为6.7 × 10~（-6）cm~2/s。2. 开发了一种基于磷脂浇铸膜的葡萄糖生物传感器。磷脂膜可以在电极表面提供一种理想的生物环境，而且能够有效地抑制一些亲水性的电活性物质到达电极表面，从而降低了它们的干扰作用。TTF被用作电子转移媒介体是因为它可以有效地转移电子，并且可心牢固地固定在磷脂膜中。工作电位、pH值对传感器的影响均做了测试。该传感器的响应时间小于20秒，线性范围从0.2 mmol/L到10 mmol/L，最低检测限为2×10~（-5） mol/L，同时，该传感器也显示出良好的重现性及稳定性。3. 选择玻碳电极作为固体基底，在其表面上制备出磷脂膜。通过电化学阻抗测试，证明了电极表面的磷脂膜为双层膜。将辣根过氧化物酶（HRP）固定在这种支撑双层磷脂膜（ s-BLM）中，并以此开发出一种不需要媒介体的H_2O_2生物传感器。该传感器显示了良好的电化学中央委员应、稳定性及重现性，这主要是因为s-BLM的存在。作为一种模拟生物膜，s-BLM可以为保持酶分子的天然活性提供一个理想的环境，因此，s-BLM将非常适合于固定酶分子，从而开发以玻碳电极为基底的不需要媒介体的生物传感器。4. 以玻碳电极作为基底，在玻碳电极上制备出支撑磷脂膜，并借助电化学阻抗手段证明了这种磷脂膜是比层膜。研究了这种支撑磷脂膜内的离子通道行为，以高氯酸根离子作为通道激发物以及吡啶钌作为标记离子，当膜内的通道打开时，产生明显的通道电流，然而没有高氯酸根存在时，通道又处于关闭状态。5. 成功地制备出由金电极表面上的半胱胺单层支撑的C_(60)-磷脂杂化膜。将血红蛋白（Hb）固定在膜内，并研究了Hb的电化学行为。C_(60)作为一种良好的电子媒介体，使得Hb在这种C_(60)-磷脂杂化膜内的电子转移变得较为容易。

钠原子团簇性质的理论研究

本论文介绍了近五年来，对钠原子团簇的理论研究中所取得的一些有意义的结果，以及在碳团簇研究方面的初步进展。在电子基态条件下，利用距离相关的紧束缚的分子动力学模型(DDTB—MD)系统研究了钠原子团簇Na_n的结构、振动、热力学、碰撞动力学等方面的特性。在团簇Na_２、Na_3、Na_4、Na_5的结构和振动研究中，发现在低温时，钠原子团簇象刚性分子一样，会呈现出固有的振动本征谱，振动谱与原子团簇的结构密切相关，不同的异构体的振动谱可以有很大的差别，通过某一团簇的振动本征谱能够重建团簇的几何形状，可作为实验上决定原子团簇结构的探针。在实验上测量的原子团簇并非都是冷的，有时原子团簇会热到足以熔化。在对原子团簇Na_4、Na_8、Na_(20)这些有限多体在有限温度下的相变研究中，发现在钠原子团簇中普遍存在着类固-类液相变现象。在O-400 K温区系统研究了Na_4的异构化，发现当T≥100 K时，存在C_(3v)和D_(2h)两种异构体之间的转变。同时，发现当T>200 K时，D_(2h)结构的Na_4出现一种新的运动模式-赝转动。赝转动前后，分子的结构不变，只是宏观取向发生改变。通过跟踪体系势能的变化，提取出赝转动势垒为O．023 eV。对第一个满壳(Na_8)附近Na_7+Na_7、Na_8+Na_8及Na_9+Na_9体系的团簇碰撞动力学性质进行了系统性研究，深入理解团簇之间的非区域力和多种运动的耗散效应，提取了双团簇分子(Na_9)_2的特征振动频率24 cm~(-1)。利用目前计算机模拟实验中最先进最重要的第一性原理分子动力学方法(FHl96MD)优化了Na_2的键长5.789 Bohr，模拟了Na_2的分子动力学，提取了Na_2振动频率235 cm~(-1)。并在FHI96MD的基础上，发展了一个在离子基态条件(冻结离子运动)下，描述复杂凝聚态体系的电子动力学的时间相关的局域密度近似(TDLDA)模型。这个模型被成功地应用于Na_2价电子对高强度超短脉冲激光的响应、强激光场中团簇Na_2的谐波产生的研究。在电子基态条件下，发展了一个经典分子动力学模型(CMD)用于研究碳富勒烯、纳米碳管的结构、热力学性质。研究了纳米碳管中封装C_(60)链的形成。关键词：紧束缚分子动力学，时间相关的局域密度近似，钠团簇，碳纳米管

快重离子在高分子材料中的强电子激发效应研究

本文简要介绍了快重离子在固体材料，特别是在高分子材料和团簇材料中引起强电子激发效应研究的发展历史、研究现状和基本理论。重点描述了在兰州重离子加速器（HIRFL）上完成的2.1 GeV Kr离子辐照聚碳酸酷CPC）膜的实验和辐照样品的傅立叶变换红外光谱（FTIR )和紫外／可见光谱(UVIVIS )分析。FTIR分析结果表明，高能Kr离子在PC膜中引起的辐照效应主要是键的断裂和材料的降解。随着电子能损和辐照剂量的增大，材料逐渐碳化，同时有炔基生成。在UVNIS中，380, 450, 500nm波长处的吸光度之差（A－A_0）与剂量近似成线性关系，与电子能损呈确定的指数关系（指数分别为1.69,1.86和2.02）；与电子能量沉积密度也近似成指数关系。描述了在HIRFL上完成的2.0GeV Xe离子辐照C_(60)薄膜的实验和辐照样品的FTIR谱、拉曼谱(Raman)和X射线衍射谱（XRD）分析。分析结果表明：2.0 GeV Xe离子辐照C60薄膜引起的损伤过程主要取决于强电子激发，在特定电子能损处，损伤的部分恢复是由于强电子激发的退火效应引起的。快重离子辐照产生的物理化学改性不仅与离子的电子能损有关，还与离子的速度有关。在同样的电子能损下，速度越小，产生的效应就越明显。

水溶性富勒醇对活性氧自由基的清除

C_(60)及其相关衍生物的生物活性研究具有重要意义.由于C_(60)分子本身是非极性的,难溶于常见的极性溶剂,使得它在生物化学领域的研究和应用受到很大的限制.合成出水溶性的C_(60)衍生物将很好地解决这一问题.1993年Friedman等人发现水溶性C_(60)衍生物[HOCO(CH_2)_2CONH(CH_2)_2-C_6H_4]_2C_(61)具有抗HIVP的作用.黄文栋等人报道了水溶性C_(60)-脂质体对人子宫颈癌细胞具有很强的杀伤效应.最近,Chiang等人采用化学发光的方法研究了多羟基C_(60)衍生物——富勒醇吞噬超氧阴离子自由基的功效,结果表明富勒醇对黄嘌呤/黄嘌呤氧化酶产生的超氧阴离子自由基具有良好的清除作用,有关富勒醇对羟基自由基的清除作用研究未见报道.

富勒醇清除·OH自由基的ESR研究

富勒醇清除·ＯＨ自由基的ＥＳＲ研究祝严师，孙大勇，刘桂珍，刘子阳，詹瑞云，刘淑莹（中国科学院长春应用化学研究所应用谱学开放实验室，长春，１３００２２）关键词Ｃ_（６０），富勒醇，ＯＨ自由基，自旋捕捉，ＥＳＲ生物体内的许多现象均涉及到自由基反应，现已发?..

Revision total hip replacement using the cement-in-cement technique for the acetabular component : technique and results for 60 hips

The technique of femoral cement-in-cement revision is well established, but there are no previous series reporting its use on the acetabular side at the time of revision total hip arthroplasty. We describe the surgical technique and report the outcome of 60 consecutive cement-in-cement revisions of the acetabular component at a mean follow-up of 8.5 years (range 5-12 years). All had a radiologically and clinically well fixed acetabular cement mantle at the time of revision. 29 patients died. No case was lost to follow-up. The 2 most common indications for acetabular revision were recurrent dislocation (77%) and to compliment a femoral revision (20%). There were 2 cases of aseptic cup loosening (3.3%) requiring re-revision. No other hip was clinically or radiologically loose (96.7%) at latest follow-up. One case was re-revised for infection, 4 for recurrent dislocation and 1 for disarticulation of a constrained component. At 5 years, the Kaplan-Meier survival rate was 100% for aseptic loosening and 92.2% (95% CI; 84.8-99.6%) with revision for all causes as the endpoint. These results support the use of the cement-in-cement revision technique in appropriate cases on the acetabular side. Theoretical advantages include preservation of bone stock, reduced operating time, reduced risk of complications and durable fixation.

Preparing high achieving English teachers to work in disadvantaged schools : 'I'll teach Shakespeare when I'm 60'

The recent release of the Gonski Review recognises the decline in Australia’s schooling performances over the last decade, noting in particular a distressing increase in the ‘achievement gap’ affecting students from low SES backgrounds (Gonski, 2012). The report details the need for more quality in teachers throughout the schooling system, particularly within the schools with the greatest academic needs. This paper specifically focuses on a group of high-achieving pre-service English teachers. In their last two years of university study, they participated in a program called Exceptional Teachers for Disadvantaged Schools (ETDS), designed to prepare them to work in disadvantaged or low SES schools. We wanted to capture their experiences of teaching in challenging settings during their practicum, and as they prepared to graduate, we wondered what they now felt about teaching English in low SES schools. Using narrative inquiry, we analysed a range of reflective data to gain insight into such things as their initial motivations for entering the teaching profession and how their preconceived expectations may or may not have shifted after practicum experiences in low SES schools. We encouraged open reflection about how they perceived themselves as English teachers.

Experimental study on creep and shrinkage of high-performance ultra-lightweight cement composite of 60 MPa

Creep and shrinkage behaviour of an ultra lightweight cement composite (ULCC) up to 450 days was evaluated in comparison with those of a normal weight aggregate concrete (NWAC) and a lightweight aggregate concrete (LWAC) with similar 28-day compressive strength. The ULCC is characterized by low density < 1500 kg/m3 and high compressive strength about 60 MPa. Autogenous shrinkage increased rapidly in the ULCC at early-age and almost 95% occurred prior to the start of creep test at 28 days. Hence, majority of shrinkage of the ULCC during creep test was drying shrinkage. Total shrinkage of the ULCC during the 450-day creep test was the lowest compared to the NWAC and LWAC. However, corresponding total creep in the ULCC was the highest with high proportion attributed to basic creep (≥ ~90%) and limited drying creep. The high creep of the ULCC is likely due to its low elastic modulus. Specific creep of the ULCC was similar to that of the NWAC, but more than 80% higher than the LWAC. Creep coefficient of the ULCC was about 47% lower than that of the NWAC but about 18% higher than that of the LWAC. Among five creep models evaluated which tend to over-estimate the creep coefficient of the ULCC, EC2 model gives acceptable prediction within +25% deviations. The EC2 model may be used as a first approximate for the creep of ULCC in the designs of steel-concrete composites or sandwich structures in the absence of other relevant creep data.

Polybrominated diphenyl ethers and age: analysis of pooled human blood serum from birth to over 60 years

Polybrominated diphenyl ethers (PBDEs) are considered to be a cost effective and efficient way to reduce flammability therefore reducing harm caused by fires. PBDEs are incorporated into a variety of manufactured products and are found worldwide in biological and environmental samples (e.g. Hites et al. 2004). Unlike other persistent organic pollutants there is limited data on PBDE concentrations by age and/or other population specific factors. Some studies have shown no variation in adult serum PBDE concentrations with age (e.g. Mazdai et al., 2003, Meironyte Guvenius et al., 2003) while Petreas et al. (2003) and Schecter et al. (2005) found results to be suggestive of an age trend in adult data but no statistically significant correlation was found. In addition to the data on adult concentrations there is limited data which investigates the levels of PBDEs in infants and young children. Fangström et al. (2005) showed that in seven year olds there was no difference in PBDE concentration when compared to adult concentrations. While Thomsen et al. (2002, 2005) found the concentration of PBDEs in pooled samples of blood serum from a 0-4 years age group to be higher than other age groups (4 to > 60 years). In addition, a family of four was studied in the U.S. and the concentrations were found to be greatest in the 18-month-old infant followed by the 5 year old child, then the mother and father (Fischer et al., 2006). The objectives of this study were to assess age, gender and regional trends of PBDE concentrations in a representative sample of the Australian population.

A New Mechanism For Ferromagnetism In C-60-TDAE

Based on the topology of C-60 and the resulting non-disjoint nature of the lowest unoccupied molecular orbitals, Ne propose a new model for ferromagnetic exchange in C-60-TDAE. Within the Hubbard model, we find that the ferromagnetic exchange integral is stabilized to first order in the inter-ball transfer integral, while the antiferromagnetic coupling is stabilized only to second order. This difference is adequate to counter the larger phase space available for stabilizing the antiferromagnetic state. Thus, the ground state is found to be ferromagnetic for reasonable inter-ball transfer integrals.

Structural and functional studies of Bacillus stearothermophilus serine hydroxymethyltransferase: the role of Asn(341), Tyr(60) and Phe(351) in tetrahydrofolate binding

SHMT (serine hydoxymethyltransferase), a type I pyridoxal 5'-phosphate-dependent enzyme, catalyses the conversion of L-serine and THF (tetrahydrofolate) into glycine and 5,10-methylene THE SHMT also catalyses several THF-independent side reactions such as cleavage of P-hydroxy amino acids, trans-amination, racemization and decarboxylation. In the present study, the residues Asn(341), Tyr(60) and Phe(351), which are likely to influence THF binding, were mutated to alanine, alanine and glycine respectively, to elucidate the role of these residues in THF-dependent and -independent reactions catalysed by SHMT. The N341A and Y60A bsSHMT (Bacillus stearothermophilus SHMT) mutants were inactive for the THF-dependent activity, while the mutations had no effect on THF-independent activity. However, mutation of Phe(351) to glycine did not have any effect oil either of the activities. The crystal structures of the glycine binary complexes of the mutants showed that N341A bsSHMT forms an external aldimine as in bsSHMT, whereas Y60A and F351G bsSHMTs exist as a Mixture of internal/external aldimine and gem-diamine forms. Crystal structures of all of the three Mutants obtained in the presence of L-allo-threonine were similar to the respective glycine binary complexes. The structure of the ternary complex of F351G bsSHMT with glycine and FTHF (5-formyl THF) showed that the monoglutamate side chain of FTHF is ordered in both the subunits of the asymmetric unit, unlike in the wild-type bsSHMT. The present studies demonstrate that the residues Asn(341) and Tyr(60) are pivotal for the binding of THF/FTHF, whereas Phe(351) is responsible for the asymmetric binding of FTHF in the two subunits of the dimer.

Costs assessment not an each-way bet: Radich v Kenway [2014] QDC 60

In Radich v Kenway [2014] QDC 60 McGinness DCJ considered issues relating to the assessment of costs under the Legal Profession Act 2007 (Qld). This recent costs assessment case from the District Court clearly illustrates the interplay between the relevant elements of the Legal Profession Act 2007 and Uniform Civil Procedure Rules 1999.