近空间升华沉积CdTe薄膜的微结构和PL谱

用近空间华法在CdS薄膜上沉积了CdTe薄膜。研究了在两种保护气氛下所沉积的多晶CdTe薄膜在后处理后的微结构、表面形貌及光致发光(PL)谱，并研究了CdTe表面的CdS/CdTe界面的P谱的区别，根据薄膜的微结构对碲化镉在太阳电池中的应用进行了讨论。

侧基发光性单体与无机纳米颗粒的组装及其光学性质

首次将具有一定共轭长度的发光性单体成功地组装在CdS无机纳米颗粒的表面上，并通过原位聚合得到了有特定有序结构的有机/无机复合材料，该组装体和复合材料表现出荧光光谱的显著红移。

5-氟尿嘧啶-β-环糊精结肠靶向前体药物的研究

5-氟尿嘧啶(5-Fluorouracil， 5-FU)是一种抗代谢药物，广泛用于临床治疗结直肠癌、胃癌、乳腺癌等多种癌症，但其首过代谢显著、亲脂性较低，选择性差、毒副作用大。为克服这些缺点人们对5-FU进行了大量的修饰工作，包括小分子修饰以及与各种载体形成微球、微囊、纳米粒、共价前药等。 环糊精(Cyclodextrin，简称CD)，可被结肠中的糖苷酶特异性地降解成小分子糖，而胃和小肠中由于缺乏相应的酶而使环糊精不被降解，这一特性在结肠药物的靶向输送及释放中有重要应用价值。环糊精中含有丰富的羟基，易进行化学修饰，将药物与环糊精通过共价键结合制成前药，使其在胃和小肠中不降解，而在盲结肠中被特异性的酶降解释出药物，达到结肠靶向释药的目的。研究表明，环糊精作为一种前药载体为结肠靶向释药和缓释、控释系统提供了一种有效的手段。 本工作选择5-氟尿嘧啶为模型药物、β-环糊精作为载体，通过中间体5-FU羧酸衍生物的制备及其与β-环糊精的偶联，合成了系列5-FU-β-CD前体药物，并利用紫外、红外、质谱、核磁、元素分析、热分析等手段对其进行结构表征。同时，还研究了前体药物的体外释药性质。具体内容包括： 1. 含有羧基的5-FU衍生物中间体的合成：(5-氟尿嘧啶-1-基)-乙酸(FUAC)、3-(5-氟尿嘧啶-1-基)-丙酸(FUPC)、5-(5-氟尿嘧啶-1-基)-戊酸(FUVC)的合成。 2. 中间体5-FU的羧酸衍生物与β-CD的偶联：分别通过以6-OTs-β-CD为中间体的取代法和活化酯法，合成了第一面取代和第二面取代的5-FU-β-CD大分子前体药物。在二面取代的前体药物制备中，通过改变原料的比例，合成了系列不同取代度(DS)的2-[(5-氟尿嘧啶-1-基)-乙酰基] -β-环糊精结合物。 3. 对上述前体药物进行体外释放研究：分别考察了前体药物在不同pH缓冲溶液中的水解行为及其在小鼠胃肠道人工体液中的酶解行为，并通过UV-Vis及HPLC对前体药物释放情况进行检测分析。 5-Fluorouracil(5-Fu), commonly known as a broad-spectrum antineoplastic drug, has been widely used in the treatment of various kinds of cancer including colon cancer for 40 years. However, this antitumor agent exhibits serious adverse effects, such as their marrow toxicity, gastrointestinal reaction and low selectivity in their clinical use. In order to improve its antitumor activity and reduce its toxicity, the compound was modified in various ways, including the formation of conjugated prodrugs with kinds of carrier, microsphere and nanoparticles etc. Cyclodextrins(CDs) are known to be barely capable of being hydrolyzed and only slightly absorbed in passing through the stomach and small intestine; however they are fermented into small saccharides by colonic microflora and thus absorbed as small saccharides in the large intestine. This biodegradation property of CDs may be useful as a colon-targeting carrier, and thus CD prodrugs may serve as a source of site-specific delivery of drugs to colon. It was demonstrated that prodrugs of CDs can provide a versatile means for construction of not only colon targeted delivery systems, but also delayed release systems. 5-Fluorouracil was taken as a model drug and β-CD as the carrier in this study. Series prodrugs of 5-FU was prepared through the preparation of reactive 5-FU derivatives containing carboxyl group and coupling to hydroxyl groups of CD. The structures of the conjugates were charactered by using IR, UV–vis, ESI-MS, 1H, 13C-NMR spectra, elemental analyses, and thermal analysis. In vitro hydrolysis behavior in aqueous solution and in rat gastrointestinal tract contents of the conjugates were also investigated. The main content of this dissertation includes following aspects: 1. The preparation of 5-FU derivatives containing carboxyl group: 5-Fluorouracil- acetic acid(FUAC)、3-(5-FU-1)-propionic acid (FUPC)、and 5-(5-FU-1)-valeric acid(FUVC). 2. The coupling of 5-FU derivatives to β-CD: 5-FU was selectively conjugated onto the primary or secondary hydroxyl groups of β-CD through an ester linkage, by the substitution of 6-OTs-β-CD and the activated ester method respectively. For the secondary face conjugation, the degree of substitution(DS) can be controlled by changing the mole ratio of the starting materials(FUAC and β-CD). 3. In vitro release behavior of the conjugates in aqueous solution and in rat gastro- intestinal tract contents of the conjugates were investigated, and the reaction was monitored and analyzed by using UV-Vis and HPLC methods.

环糊精衍生物的设计、合成及其对环辛烯光异构化研究

环糊精(Cyclodextrins, CDs)经化学修饰后可以得到各种类型的衍生物，不仅可以扩展其原有的键合能力，而且还可以改变其选择性，是当代超分子化学的一个研究热点。环糊精第二面的仲羟基比第一面的伯羟基有着更好的催化性能，第二面的选择性修饰将产生更多有价值的衍生物，可用于催化、酶模拟、手性识别等方面。 取代苯甲酰基修饰环糊精对顺式环辛烯(cis-cyclooctene)光异构化反应有非常重要的影响作用，苯环上取代基的性质和取代位置与产物的%ee值和对映体构型之间存在某种内在联系。有目的地选择适宜取代基，设计、合成新型环糊精光增感剂, 有可能按预定目的得到更高%ee值的反式环辛烯；同时，取代苯甲酰基修饰环糊精对cis-cyclooctene光异构化的增感机理有待于进一步阐明。 本论文工作对环糊精的化学修饰以及超分子体系对cis-cyclooctene不对称光异构化反应方面的进展进行了调研。合成了一系列单-6-位取代苯甲酰基修饰环糊精，用于cis-cyclooctene光异构化增感反应，并用圆二色光谱滴定法研究这些环糊精衍生物与cis-cyclooctene的相互作用，以探索光增感反应机理。在此基础上，探讨了环糊精第二面的选择性修饰方法。内容主要包括： 1. 简要介绍了超分子化学的概况，并对环糊精的选择性修饰方法和超分子体系对cis-cyclooctene不对称光异构化反应的主要成果和最新进展进行了评述。 2. 合成了12种单-6-O-(取代苯甲酰基)-β-环糊精，其中10种为新化合物。采用紫外光谱、红外光谱、核磁共振波谱以及质谱等手段对化合物的结构进行了表征。 3. 探索了直接选择性修饰环糊精第二面的便捷新方法。用取代苯甲酰咪唑酯为酰化试剂，0.2M碳酸盐缓冲溶液(pH=9.9)作催化剂，能够有效地活化2-位仲羟基，对环糊精第二面进行选择性修饰，此方法既简便又经济；同时，发现取代苯甲酰基能够在β-CD第二面的2-位、3-位羟基间相互迁移。 4. 用单-6-O-(取代苯甲酰基)-β-环糊精作光增感剂，对cis-cyclooctene光异构化反应进行研究。实验结果证明：取代苯甲酰基上的取代基性质、位置、长度对反应的对映选择性有很大影响；此外，反应体系溶剂极性对产物的%ee值和对映体构型也有重大影响。用单-6-O-(3-甲氧苯甲酰基)-β-CD作增感剂，cis-cyclooctene光异构化反应产物(R)-trans-cyclooctene的对映选择性为45.8%ee，是到目前为止取得的最好对映选择性。 5. 采用圆二色光谱滴定法研究环糊精衍生物与cis-cyclooctene的相互作用，计算包结物的平衡常数，研究包结物的相对稳定性，为探索光增感反应机理提供基础。我们猜测：电子效应对cis-cyclooctene光异构化反应的影响，可能比取代基位置对反应的影响更大，借助电子效应有希望获得更高的%ee值。 Cyclodextrins can be subjected to diverse modifications to give a wide variety of cyclodextrin derivatives, which could not only extend their original molecular binding ability, but also alter their molecular selectivity. Therefore, cyclodextrin chemistry is currently a significant topic in supramolecular chemistry. The more open secondary hydroxyl side of CDs is stated to be catalytically very important, modifications of this face are believed to produce valuable derivatives for catalysis, enzyme mimic, chiral discrimination, etc. Mono-6-O-(substituted benzoyl)-β-CDs as novel supramolecular photosensitizing hosts have recently excited considerable attention in photochirogenesis. The supramolecular photosenstization of cis-cyclooctene mediated by them gave chiral trans-cyclooctene, enantiomeric excess of which was critically affected by the substituent introduced to the sensitizer moiety. In order to enhance the photoenantiodifferentiating ability, and elucidate the origin mechanisms of substituent-dependent enantioselectivity, in this work a series of mono-6-O-(substituted benzoyl)-β-CDs have been synthesized, and applied for enantiodifferentiating photoisomerization of cis-cyclooctene. The major contents are as follows: 1. The general aspects of supramolecular chemistry were descibed briefly. The new progress and important achievements on methods of selective modification of cyclodextrin and supramolecular enantiodifferentiating photoisomerization of cis-cyclooctene were reviewed. 2. Twelve mono-6-O-(substituted benzoyl)-β-CDs including ten novel compounds have been synthesized. Their structures have been characterized by using UV-vis, IR, NMR and MS methods. 3. A new convenient strategy for direct acylation of β-cyclodextrin on the secondary hydroxyl face was achieved by using the combination of N-benzoylimidazole and carbonate buffer in DMF, and the acyl migration between the C-2 and C-3 hydroxyl groups of β-cyclodextrin was found. 4. Experiments using mono-6-O-(substituted benzoyl)-β-CDs as chiral sensitizing hosts for mediating the enantiodifferentiating photoisomerization of cis-cyclooctene, were carried out. The results indicate that enantiomeric excess was critically affected, or even switched in sign, by the substituent introduced to the sensitizer moiety, and polarity of solvent. Using mono-6-O-(3-methoxybenzoyl)-β-CD as chiral sensitizing host, (R)-trans-cyclooctene was obtained in up to 45.8% enantiomeric excess, which is the highest value ever reported for supramolecular photochirogenesis with analogous hosts. 5. The conformational variation of these modified CDs and their complexation behaviors with cis-cyclooctene were examined by circular dichroism spectroscopy in water-methanol mixed solvents, which reveal that the orientation of chromophore was highly sensitive to the type, position and length of the introduced substituents. In the end, the complex stability constants(Ks) were calculated, and the mechanisms of reaction were discussed. Maybe, electronic effects are more important than positions of substituents for mediating the enantiodifferentiating photoisomerization of cis-cyclooctene.

人载脂蛋白APOA5的克隆表达纯化及相互作用蛋白研究

人类的载脂蛋白A5（apolipoprotein A5，APOA5）是一个新近发现的载脂蛋白家族成员。它在血浆中的含量比其他载脂蛋白低1-2个数量级，但能显著影响血浆三酰甘油水平，对血脂代谢具有重要意义，可以作为降血脂药物治疗中一个强有力的潜在靶标。 由于APOA5在血浆中含量低，直接从血浆中分离纯化很困难，国内一直没有报道简易可靠的纯化方法。为进一步研究APOA5的生物学特性，探讨其与TG代谢中的其它关键成分之间的相互关系，揭示其在脂类代谢相关疾病中的重要地位，必须有大量的蛋白和抗体用于基础研究。因此本研究首先利用基因工程技术，诱导表达纯化APOA5蛋白，免疫动物制备多克隆抗体，为进一步研究人肝脏细胞中APOA5的相互作用蛋白，研究APOA5蛋白在肝脏细胞中的功能奠定基础。 为了深入研究APOA5在肝脏中如何行使功能，我们采用细菌双杂交技术寻找与APOA5相互作用的蛋白因子。并采用Pull-down技术，免疫荧光及免疫共沉淀技术进一步确证其在体外和体内的相互作用关系，为进一步阐明APOA5在体内的生理功能提供了新的线索。 第一部分 APOA5基因的克隆、原核表达、纯化及其多克隆抗体的制备 本研究首先应用基因克隆技术，从人肝癌细胞系SMMC-7721的cDNA中扩增出1.1 kb的ApoA5基因全长序列。然后将其克隆至表达载体pThioHisD，构建原核表达载体pTH-APOA5。该重组质粒转化至大肠杆菌 BL21（DE3），成功实现人APOA5融合蛋白在大肠杆菌中的表达。经发酵得到高效表达的融合蛋白。 融合蛋白在 IPGT 诱导下以包涵体的形式大量表达。利用融合蛋白上的一段组氨酸序列，用镍离子亲和柱进行纯化和复性后，获得较高纯度的人APOA5融合蛋白。利用该融合蛋白免疫新西兰大耳白兔，获得了高效价的兔抗人APOA5多克隆抗体，Western Blot结果显示此多克隆抗体与APOA5特异性结合。 第二部分 细菌双杂交筛选与APOA5相互作用的蛋白 本实验首先构建了pBT-APOA5重组质粒，经双酶切、PCR和测序鉴定证明重组诱饵质粒构建成功，并进行了表达、自激活鉴定。Western Blot鉴定证实报告菌株中表达了分子量为 68 kD左右的重组融合蛋白，与预测的分子量APOA5（41 kD）/lamda cI （27 kD）一致。自激活实验证明诱饵蛋白不能单独激活报告基因，可用于筛选人肝脏cDNA文库。经过双重抗性筛选和回复筛选，分离出10个阳性克隆。对结果进行生物信息学分析，得到7个与APOA5相互作用的蛋白，其中BI1为细胞凋亡调节因子；ATP6、CYTB、ND2、COX-1为线粒体表达蛋白； ALB、TTR为血清蛋白。 第三部分 APOA5与BI1相互作用的确证 首先构建了BI1的原核表达载体pGEX-5X-3-BI1，利用Pull-down实验检测了APOA5与BI1在体外具有相互作用。然后构建了BI1的真核表达载体pCDNA3.1-HA-BI1和APOA5的真核表达载体pCDNA3.1-APOA5，并验证其表达。通过免疫荧光细胞内共定位研究发现，靶蛋白APOA5主要分布于胞浆，与BI1在HEK293细胞有共定位，即APOA5与BI1存在相互作用的可能。最后利用免疫共沉淀手段，在HEK293细胞中确证了靶蛋白APOA5与BI1在体内的相互作用。 上述研究结果，为深入研究APOA5在体内的生物学功能提供了新的思路。 Apolipoprotein A5 (APOA5) is a newly discovered protein belongs to apolipoprotein family. APOA5’s concentration is 1-2 orders of magnitude lower than other apolipoproteins in the circulation. APOA5 significantly affected plasma triglyceride levels, which is important on lipid metabolism. APOA5 has strong potential to be used as a hypolipidemic drug target. Large amount of APOA5 protein and antibodies are needed in basic research, such as biological characteristics study of the APOA5, its relationship with other key components in TG metabolism, its role played in Lipid metabolism-related diseases. Due to its low concentration in plasma, separation and purification of APOA5 from the plasma is very difficult. Until now no report on simple and reliable method for purification has been published in China. In this study, we firstly got APOA5 recombinant protein using genetic engineering technology. The purified recombinant protein was used to immunize rabbits to get antiserum. It is important for further study of the APOA5 protein-interacting protein. And it lays the foundation for studing APOA5 function in liver. In order to study APOA5 function in liver, we used bacterial two-hybrid technology to find the APOA5 protein interactor. Pull-down, immunofluorescence and immunoprecipitation techniques were used to further confirm the interaction between APOA5 with its interactor in vitro and in vivo. All of these stdudies provided new clues on its physiological functions in vivo. Part I: Cloning, prokaryotic expression, purification and polyclonal antibody preparation of APOA5 First of all, we amplified APOA5 CDS sequence from the human hepatoma cell line SMMC-7721, and subcloned into Expression vector pThioHisD, and got the recombinants named pTH-APOA5. The plasmid was transformed to BL21 (DE3). E. coli BL21(DE3) cells bearing the pTH-APOA5 plasmid were cultured and APOA5 protein synthesis was induced by the addition of IPTG. Recombinant protein was expression in the form of inclusion. Inclusion bodies were dissolved in phosphate-buffered saline containing 8 M urea and 40 mM imidazole, then applied to a Ni2+ affinity column, and were eluted in a buffer containing 4 M urea and 200 mM imidazole. Fractions containing the APOA5 protein were pooled and dialyzed against buffer containing phosphate-buffered saline. Antiserum to recombinant human APOA5 was generated by immuning rabbit. Western Blot showed that this antiserum specific binding with APOA5. Part II Two-hybrid system screening protein interactions with the APOA5 The coding sequence of human APOA5 was amplified using synthetic oligonucleotide primers from pTH-APOA5 vector and was subcloned into the pBT plasmidc to yield pBT-APOA5 vector. DNA sequencing was performed to verify that no unwanted mutations occurred during the process of plasmid vector construction. We verified recombinant protein expression and tested self-activation by pBT-APOA5 prior to screening. Western Blot verified inducing a 68 kD band, consistent with the predicted molecular weight (APOA5 41 kD, lamda cI 27 kD). pBT-APOA5 can be used for screening human liver cDNA library because it can not self-activation. Totally 10 positive clones were isolated. The nucleotide sequence of the positive clones were determined and compared to NCBI nucleotide sequence databases. We got 7 protein which interact with APOA5, included BI1(Apoptosis regulator); ATP6, CYTB, ND2, COX-1(Mitochondrial protein) and ALB, TTR(Serum protein). Part III Confirming of interaction between APOA5 with BI1 pGEX-5X-3-BI1 vector was subcloned at first. Pull-down experiments were used to detect the interaction between APOA5 with BI1 in vitro. Later, pCDNA3.1-HA-BI1 and pCDNA3.1-APOA5 were subcloned. Through immunofluorescence co-localization study, we found APOA5 mainly distributed in the cytoplasm. APOA5 is co-localization with BI1 in HEK293 cells. Finally, we verified interaction between APOA5 with BI1 in vivo through immunoprecipitation.

利用重离子径迹模板制备纳米线/纳米管及其光学性质测量

本论文主要研究内容包括重离子径迹模板的制备，一维纳米材料包括半导体CdS纳米线/管和金属Cu纳米线的制备，以及纳米线/管的光学性质测量三个部分。利用高能重离子辐照、蚀刻技术，制备了不同孔径的聚碳酸酯和白云母两种模板。聚碳酸酯模板的孔道形状为圆柱形。云母模板的孔道形状与蚀刻时间有关，短时间蚀刻为圆形，长时间蚀刻为菱形。利用聚碳酸酯模板结合电化学的方法可控制备了CdS纳米线和纳米管。纳米线和纳米管的直径在20至110 nm，长度在十几个微米。X射线衍射和选区电子衍射表明所制备的CdS纳米线和纳米管为多晶结构。通过对嵌有CdS纳米线和纳米管的聚碳酸酯模板的紫外可见光谱分析，发现随着纳米线和纳米管尺寸减小，吸收峰明显蓝移。实验中同时发现，制备的CdS纳米线是由纳米管通过填充生长机制产生的。利用白云母模板结合电化学方法可控制备了金属Cu纳米线。Cu纳米线的形状由模板孔道的形状决定。通过嵌有Cu纳米线的云母模板的紫外可见光谱分析，发现直径小于60 nm的Cu纳米线有一个强的共振峰和一个微弱的次峰。随着纳米线直径增加，吸收峰发生明显的红移，同时次峰增强。结果表明，Cu纳米线直径和形状可以改变电子的共振模式，从而引起纳米线光吸收的改变

Transient state of chiral recognition in a binary mixture of cyclodextrins in capillary electrophoresis

The transient state (as the defined point where no enantioseparation is obtained in a dual chiral selector system) of chiral recognition of aminoglutethimide in a binary mixture of neutral cyclodextrins (CDs) was studied by capillary electrophoresis (CE). The following three dual selector systems were used: alpha-cyclodextrin (alpha-CD) and beta-cyclodextrin (beta-CD); alpha-CD and heptakis(di-O-methyl-beta-cyclodextrin) (DM-beta-CD); alpha-CD and heptakis(tri-O-methyl-beta-cyclodextrin) (TM-beta-CD). The S-(-) enantiomer of the analyte was more strongly retained in the presence of either alpha-CD or TM-beta-CD at pH 2.5, 100 mM phosphate buffer, while the R-(+) enantiomer was more strongly retained in the presence of either P-CD or DM-P-CD. In the more simple case, the elution order is invariably kept if the enantiomers have the same elution order in either one of the two hosts of the binary mixture. In contrast, the elution order may be switched by varying the concentration ratio of two hosts that produce opposite elution order for this particular analyte. In such a dual selector system, the enantioselectivity will disappear at the transient state at a certain ratio of host,:host, Moreover, the migration times of the two enantiomers with host, alone (diluted in buffer) is approximately equal to the migration times at the corresponding concentration of host, alone (diluted in buffer), where the ratio of concentrations of host,:host, is the same as in the binary mixture at the transient state. As found by nuclear magnetic resonance experiments, the analyte is forming a 1:1 complex with either one of the CDs applied. From this finding, a theoretical model based on the mobility difference of the two enantiomers was derived that was used to simulate the transient state. (C) 2000 Elsevier Science B.V. All rights reserved.

Separation of drug enantiomers by capillary electrophoresis in the presence of neutral cyclodextrins

This is a selected review, highlighting our results obtained in an extended screening program ("The German-Chinese Drug Screening Program"), with a focus on a set of original data obtained with heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin(TM-beta-CD) as the chiral solvating agent (CSA). The enantioseparation of 86 drugs by capillary zone electrophoresis in the presence of this CSA was successful for 47 drugs. The migration separation factors (alpha(m)) and the migration retardation factors (R-m) were compared with those found for native beta-cyclodextrin (beta-CD). The patterns thus obtained were also compared with those observed for hexakis(2,3,6-tri-O-methyl)-alpha-CD (TM-alpha-CD) and octakis(2,3,6-tri-O-methyl)-gamma-CD (TM-gamma-CD), respectively. From the statistical data, it can be concluded that there is a remarkable influence of the analyte structure on the electrophoretic data. A substructure 4H was found in the analyte structure that has a significant influence on the analytes' behaviour. Thus, analytes bearing the substructure 4H do not only have a strong affinity to the CDs but also a high rate of success of chiral separation in all systems reviewed. In light of this, the different ring sizes of native cyclodextrins (alpha-, beta- and gamma-CD) readily explain their behaviour towards a limited test set of chiral drugs. Sterical considerations point to the significance of side-on-binding versus inclusion in the cavity of the host. In addition to the findings from the screening program, numerous references to the Literature are given. (C) 2000 Elsevier Science B.V. All rights reserved.

Polyol-Mediated Synthesis of PbS Crystals: Shape Evolution and Growth Mechanism

An interesting shape evolution of. PbS crystals, that is, from cubes to (truncated) octahedra and finally to stable star-shaped multipods with six arms along the < 100 > directions is first realized via a facile polyol-mediated reaction between lead acetate and sulfur powder in the absence of surfactants. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared (FT-IR) techniques were employed to characterize the samples. We elucidate the important parameters (including reaction temperature and sulfur sources) responsible for the shape-controlled synthesis of PbS crystals.

Controlled synthesis of monodisperse nanocrystals by a two-phase approach without the separation of nucleation and growth processes

The synthesis of monodisperse nanocrystals is an important topic in the field of nanomaterials not only for practical applications, but also for scientific interest in fundamental research. In this feature article, we mainly focus on synthesis of monodisperse nanocrystals by a two-phase approach without the separation of nucleation and growth processes, and report some progress made recently in the observation and understanding of nucleation and growth of semiconductor nanocrystals. Firstly, a novel two-phase approach to monodisperse nanocrystals, which is different from the well-established synthesis models, is discussed. We demonstrate that the two-phase approach has a quite lengthy nucleation process, and can be applied to the synthesis of many kinds of binary monodisperse nanocrystals.

One step to detect the latent fingermarks with gold nanoparticles

A simple and environment friendly chemical route for detecting latent fingermarks by one-step single-metal nanoparticles deposition method (SND) was achieved successfully on several non-porous items. Gold nanoparticles (AuNPs) synthesized using sodium borohydride as reducing agent in the presence of glucose, were used as working solution for latent fingermarks detection. The SND technique just needs one step to obtain clear ridge details in a wide pH range (2.5-5.0), whereas the standard multi-metal deposition (MMD) technique requires six baths in a narrow pH range (2.5-2.8). The SND is very convenient to detect latent fingermarks in forensic scene or laboratory for forensic operators. The SND technique provided sharp and clear development of latent fingermarks, without background staining, dramatically diminished the bath steps.

Photoinduced DNA Cleavage by alpha-, beta-, and gamma-Cyclodextrin-Bicapped C-60 Supramolecular Complexes

Water-soluble supramolecular inclusion complexes of alpha-, beta-, and gamma-cyclodextrin-bicapped C-60 (CD/C-60) have been investigated for their photoinduced DNA cleavage activities, with the aim to assess the potential health risks of this class of compounds and to understand the effect of host cyclodextrins having different cavity dimensions. Factors such as incubation temperature, irradiation time, and concentration of NADH or CDs/C-60 supramolecular inclusion complexes have been examined. The results show that alpha-, beta-, and gamma-CDs/C-60 are all able to cleave double-stranded DNA under visible light irradiation in the presence of NADH. However, a difference in the photoinduced DNA cleavage efficiency is observed, where the cleavage efficiency increases in the order of alpha-, beta-, and gamma-CD/C-60. The difference is attributed to the different aggregation behavior of the inclusion complexes in aqueous solution, which is correlated to the cavity dimension of the host cyclodextrin molecules.

Fast and facile preparation of superhigh aspect-ratio Cu-thiourea nanowires in large quantity

Superhigh aspect-ratio Cu-thiourea (Cu(tu)) nanowires have been synthesized in large quantity via a fast and facile method. Nanowires of Cu (tu)Cl center dot 0.5H(2)O and Cu(tu)Br center dot 0.5H(2)O were found to be 60-100 nm and 100-200 nm, in diameter, and could extend to several millimeters in length. It is found to be the most convenient and facile approach to the fabrication of one-dimensional superhigh aspect-ratio nanomaterials in large scale so far.

Characterization of non-covalent complexes of rutin with cyclodextrins by electrospray ionization tandem mass spectrometry

Electrospray ionization tandem mass spectrometry (ESI-MSn) and the phase solubility method were used to characterize the gas-phase and solution-phase non-covalent complexes between rutin (R) and alpha-, beta- and gamma-cyclodextrins (CDs). The direct correlation between mass spectrometric results and solution-phase behavior is thus revealed. The order of the 1:1 association constants (K-c) of the complexes between R and the three CDs in solution calculated from solubility diagrams is in good agreement with the order of their relative peak intensities and relative collision-induced dissociation (CID) energies of the complexes under the same ESI-MSn condition in both the positive and negative ion modes. Not only the binding stoichiometry but also the relative stabilities and even binding sites of the CD-R complexes can be elucidated by ESI-MSn. The diagnostic fragmentation of CD-R complexes, with a significant contribution of covalent fragmentation of rutin leaving the quercetin (Q) moiety attached to the CDs, provides convincing evidence for the formation of inclusion complexes between R and CDs. The diagnostic fragment ions can be partly confirmed by the complexes between Q and CDs. The gas-phase stability order of the deprotonated CD-R complexes is beta-CD-R > alpha-CD-R > gamma-CD/R; beta-CD seems to bind R more strongly than the other CDs.

Studies on microstructure bilayer film of ultrasonic dipped cadmium sulfide and d.c. sputtered indium tin oxide

A bilayer CdS/ITO film was obtained. The dipped CdS was grown by an ultrasonic colloid deposition (USCD) method. Microstructure of the CdS film made by USCD has a wider transmission range and a higher transmittance. Amorphous indium-tin-oxide (ITO) thin film was deposited using d.c. magnetron-sputtering at room temperature. The ITO films exhibited good conductivity and maximum transmittance of 94%. The CdS/ITO bilayer was investigated by means of GIXD (grazing incidence X-ray diffraction) at different incidence angles (alpha = 0.20-5.00degrees) and XRD. We discuss a model for the thin bilayer film. SEM and AFM show that homogeneous CdS films with a bar-shaped ultrafine particles and ITO film with nanometer structure. The mechanism of the bilayer CdS/ITO film is discussed.