一种新型酶生物燃料电池阳极构建及性能研究

通过酸化碳纳米管(CNTs)和β-环糊精(β-CD)之间的范德华力作用, 实现CNTs的β-CD功能化. β-CD具有内腔疏水、外壁亲水的环状结构, 其内腔容易与二茂铁(Fc)形成稳定的主客体包合结构, 实现Fc在碳纳米管上的高效固载; 再将CNTs-β-CD-Fc复合物与葡萄糖氧化酶(GOD)混合, 采用戊二醛实现酶分子间的交联, 形成GOD/CNTs-β-CD-Fc复合物, 然后将其涂覆到玻碳电极(GC)上, 得到一种新型的酶生物燃料电池阳极(GOD/CNTs-β-CD-Fc/GC). 采用同步热分析法、傅里叶变换红外光谱和透射电子显微镜对所制备的CNTs-β-CD-Fc复合物进行了表征, 采用循环伏安法研究了GOD/CNTs-β-CD-Fc/GC电极对葡萄糖氧化的催化性能. 结果表明: 在同等实验条件下, 没有固载Fc的GOD/CNTs- β-CD/GC电极基本无催化电流, 而GOD/CNTs-β-CD-Fc/GC电极表现出比GOD/CNTs-Fc/GC电极更为优越的电催化性能. 进一步以GOD/CNTs-β-CD-Fc/GC电极或GOD/CNTs-Fc/GC电极为酶阳极, 商用催化剂E-TEK Pt/C电极(E-TEK Pt/C/GC)为阴极, 构建葡萄糖/氧气生物燃料电池(EBFC), 结果表明前者的最大功率密度(33 μW·cm^-2, 0.18 V)几乎是后者的三倍(11.7 μW·cm^-2, 0.16 V). 通过记录开路电位随时间的变化研究了EBFC的稳定性, 以GOD/CNTs-β-CD-Fc/GC电极为阳极的EBFC在连续工作9 h后仍保留了92%的开路电位, 表明该电池具有良好的连续工作稳定性. 我们提出的这种新型生物燃料电池阳极的构造方法, 为构建高性能、高稳定性的葡萄糖/氧气EBFC提供了新的思路.     

化学基元组学与药物创新

化学基元组学（chemomics）是与化学信息学、生物信息学、合成化学等学科相关的交叉学科．生物系统从内源性小分子（天然砌块）出发,通过酶催化的化学反应序列制造天然产物．生物系统通过化学反应和天然砌块向目标天然产物“砌入”一组原子,这样的一组原子称为化学基元（chemoyl）．化学基元组（chemome）是生物组织中所含有的化学基元的全体．化学基元组学研究各种化学基元的结构、组装与演化的基本规律．在生存压力和繁衍需求的驱动下,生物系统已经进化出有效手段来合成天然产物以应付环境的变化,并产生了丰富多彩的生物和化学多样性．近年来,人们意识到药物创新的瓶颈之一是药物筛选资源的日益枯竭．化学基元组学可以解决这个瓶颈问题,它通过揭示生物系统制备化学多样性的规律,发展仿生合成方法制备类天然化合物库（quasi natural product libraries）以供药物筛选．本文综述了化学基元组学的主要研究内容及其在药物创新各领域中的潜在应用．     

Optical properties of nanocrystalline Y2O3:Eu depending on its odd structure

The structure of nanocrystalline Y2O3:Eu prepared by a combustion reaction was analyzed by XRD and high-resolution electron microscopy. Compared with a large-scale particles, 5-nm Y2O3:Eu particles presented as distorted crystallite and rough surfaces. Luminescent and absorption properties of nano-Y2O3:Eu showed remarkably particle size effects. At Y2O3:Eu particle sizes smaller than 10 nm some new results were observed: (a) a red shift of the charge-transfer-state absorption; (b) new emission bands of Eu3+ in the 5D0 --> 7F2 region; (c) luminescent decay of energy level 5D0 of Eu3+ turning to a two-step exponential; and (d) a pronounced increase in quenching concentration and much lower phonon density compared with those of the bulk material. All these phenomena can be attributed to the effect of the softened lattice and surface state of the nanomaterial. The latter was confirmed by stronger excitation by the host absorption after the surface modification.     

Alkaloids from Juglans Mandshurica maxim induce distinctive cell death in hepatocellular carcinoma cells

The aim of this work was to further investigate the anticancer potential of Juglans mandshurica Maxim, including the separation of active constituents and their anti-proliferative effects with underlying mechanism of action. Five alkaloids (1–5) were isolated from the bark of J. mandshurica. Among them, 1 showed the highest cytotoxic activities against Hep3B and HepG2 cells with an IC50 values of 61.80 and 56.24 μM, respectively. Therefore, the cellular mechanism involved 1 was subsequently studied. Our results showed that 1 markedly caused apoptosis and autophagy, but without cell cycle arrest in HepG2 cells. Interestingly, only autophagic cell death was induced in 1-treated Hep3B cells. It is concluded that the isolated alkaloids exerted a certain anti-hepatoma potential, and our results may provide a basis for the further investigation of the alkaloids extracted from J. mandshurica.     

Electroformation and collection of giant liposomes on an integrated microchip

In this work, a microchip was developed for the electroformation and collection of giant liposomes. On the chip, a reactor chamber array was expressly designed so that the influences of multiple parameters could be explored rapidly and efficiently to screen for a suitable condition. Furthermore, in order to overcome the difficulty in the collection of giant liposomes, a tailor-made collection chamber was also integrated on this chip.     

Selective enrichment of glycopeptides based on copper tetra(N‐carbonylacrylic) aminephthalocyanine and iminodiacetic acid functionalized polymer monolith

Efficient separation and enrichment of low‐abundance glycopeptides from complex biological samples is the key to the discovery of disease biomarkers. In this work, a new material was prepared by coating copper tetra(N‐carbonylacrylic) aminephthalocyanine and iminodiacetic acid onto poly(glycidyl methacrylate‐pentaerythritol triacrylate) monolith. The monolith was applied to polymer monolithic microextraction for specific capture of glycopeptides coupled with matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry. The developed monolith exhibited satisfactory efficiency for glycopeptide enrichment with high selectivity and detection sensitivity. When the tryptic digest of immunoglobulin G was used as the sample, total 24 glycopeptides were identified and the detection limit was determined as 5 fmol. When the approach was applied to the analysis of glycopeptides in the mixture of bovine serum albumin and immunoglobulin G (100:1, m/m) digests, 16 glycopeptides could still be observed. Moreover, the monolith was successfully applied to the selective enrichment of glycopeptides from human serum digests, exhibiting great practicability in identifying low‐abundance glycopeptides in complex biological samples.     

含吗啉基片段的水杨醛席夫碱类化合物的合成及其淬灭1,1-二苯基-2-三硝基苯肼自由基性能

通过3-氟-4-吗啉基苯胺和取代水杨醛缩合反应,合成了14个含吗啉基片段水杨醛席夫碱类化合物(Ⅰa-Ⅰn)。通过核磁共振波谱仪(NMR)、傅里叶变换红外光谱仪(FTIR)、液相色谱-质谱联用仪(LC-MS)和元素分析等技术手段研究了产物的结构和淬灭1,1-二苯基-2-三硝基苯肼(DPPH)自由基的活性。 结果表明,在0.02~0.10 g/L,所有化合物均表现出一定的淬灭DPPH自由基活性。 其中,化合物Ⅰd和Ⅰf表现出较为优异的性能,化合物Ⅰd的活性在30%~55%,化合物Ⅰf的活性则大于50%。 随着化合物Ⅰd、Ⅰh、Ⅰj和Ⅰn质量浓度的增大,其淬灭DPPH自由基的活性均呈现增强趋势。     

AIEgens/Nucleic Acid Nanostructures for Bioanalytical Applications

DNA occupies significant roles in life processes, which include encoding the sequences of proteins and accurately transferring genetic information from generation to generation. Recent discoveries have demonstrated that a variety of biological functions are correlated with DNA′s conformational transitions. The non‐B form has attained great attention among the diverse forms of DNA over the past several years. The main reason for this is that a large number of studies have shown that the non‐B form of DNA is associated with gross deletions, inversions, duplications, translocations as well as simple repeating sequences, which therefore causes human diseases. Consequently, the conformational transition of DNA between the B‐form and the non‐B form is important for biology. Conventional fluorescence probes based on the conformational transitions of DNA usually need a fluorophore and a quencher group, which suffers from the complex design of the structure and tedious synthetic procedures. Moreover, conventional fluorescence probes are subject to the aggregation‐caused quenching (ACQ) effect, which limits their application toward imaging and analyte detection. Fluorogens exhibiting aggregation‐induced emission (AIE) have attracted tremendous attention over the past decade. By taking advantage of this unique behavior, plenty of fluorescent switch‐on probes without the incorporation of fluorescent quenchers/fluorophore pairs have been widely developed as biosensors for imaging a variety of analytes. Herein, the recent progress in bioanalytical applications on the basis of aggregation‐induced emission luminogens (AIEgens)/nucleic acid nanostructures are presented and discussed.     

多壁碳纳米管对稀土元素的吸附性能

研究了改性多壁碳纳米管(MWCNTs)对稀土元素的吸附。 采用硝酸、次氯酸钠、过氧化氢、高锰酸钾4种方法对MWCNTs进行改性,考察了改性MWCNTs对稀土元素的吸附能力。 采用紫外-可见分光光度法测定稀土元素的浓度,比较了未处理和不同方法处理的MWCNTs对稀土元素的吸附能力。实验结果表明,NaClO改性的MWCNTs对稀土元素的吸附能力最强。以稀土元素钐(Sm)、钆(Gd)、镱(Yb)为代表,研究了NaClO改性MWCNTs对稀土元素的吸附性能。 考察了溶液pH值、离子强度、吸附剂用量、温度等因素对吸附性能的影响。当溶液pH值在2~7范围内,NaClO改性的MWCNTs对Sm、Gd、Yb的吸附随pH值增大而增强。 当离子强度和MWCNTs的用量增大时,对稀土元素的吸附能力降低。3种元素在NaClO改性的MWCNTs上的吸附均为放热过程,其反应焓变ΔH分别为：-6.44、-5.63和8.31 kJ/mol。吸附等温线符合Langmuir和Freundlich等温吸附方程。