A radioanalytical technique to study the behavior of organic toxicants applied to a study of the photodegradation of 2,3,7,8-tetrachlorodibenzo-p-dioxin

A general method for tritium labeling of organic compounds by the use of thermal activation of tritium is described. It allows obtaining uniformly tritium-labeled organic compounds with high specific activity (up to 50 Ci/mmol) which permits tracing the majority of the biodegradation products of compounds studied. More than 40 compounds were labeled using this simple, rapid and inexpensive method. Separation of the biodegradation products is performed by thin layer chromatography. Quantification is performed by direct measurement of the radioactivity by liquid scintillation counting after transfer of the layer from TLC plates into scintillation vials, or by densitometry of autoradiographs. The technique is useful for a wide range of organic compounds, including ones with unknown structure, and can be applied to various in vivo and in vitro studies.     

Nano‐amylose‐2,3‐bis(3,5‐dimethylphenylcarbamate)‐silica hybrid sol immobilized on open tubular capillary column for capillary electrochromatography enantioseparation

The chiral organic‐inorganic hybrid materials can exhibit a high loading, and the chiral selector nanoparticles can create efficient stationary phases for open‐tubular capillary electrochromatography (OT‐CEC). Hence, a novel protocol for the preparation of an OT column coated with nano‐amylose‐2,3‐bis(3,5‐dimethylphenylcarbamate) (nano‐ABDMPC)‐silica hybrid sol through in situ layer‐by‐layer self‐assembly method was developed for CEC enantioseparation. By controlling the assembly cycle number of nano‐ABDMPC‐silica hybrid sol, a homogeneous, dense and stable coating was successfully prepared, which was confirmed by SEM and elemental analysis. As the main parameter influencing the chiral separating effect, the nano‐ABDMPC bearing 3‐(triethoxysilyl)propyl residues concentration was investigated. The experimental results showed that 10.0 mg/mL nano‐ABDMPC bearing 3‐(triethoxysilyl)propyl residues coated OT capillary column possessed chiral recognition ability toward the six enantiomers (phenylalanine, tyrosine, tryptophan, phenethyl alcohol, 1‐phenyl‐2‐propanol, and Tröger's base) at some of the different conditions tested. Additionally, the coated OT column revealed adequate repeatability concerning run‐to‐run, day‐to‐day and column‐to‐column. These results demonstrated the promising applicability of nano‐ABDMPC‐silica hybrid sol coated OT column in CEC enantioseparations.     

Green Approach to the Fabrication of Superhydrophobic Mesh Surface for Oil/Water Separation

We report a simple and environment friendly method to fabricate superhydrophobic metallic mesh surfaces for oil/water separation. The obtained mesh surface exhibits superhydrophobicity and superoleophilicity after it was dried in an oven at 200 °C for 10 min. A rough silver layer is formed on the mesh surface after immersion, and the spontaneous adsorption of airborne carbon contaminants on the silver surface lower the surface free energy of the mesh. No low‐surface‐energy reagents and/or volatile organic solvents are used. In addition, we demonstrate that by using the mesh box, oils can be separated and collected from the surface of water repeatedly, and that high separation efficiencies of larger than 92 % are retained for various oils. Moreover, the superhydrophobic mesh also possesses excellent corrosion resistance and thermal stability. Hence, these superhydrophobic meshes might be good candidates for the practical separation of oil from the surface of water.     

Black painted pottery, Kildehuse II, Odense County, Denmark

This work aimed at characterization of a black layer covering a Bronze Age (period VI) pot surface. To solve research problems plane polarized light microscopy (PLM), scanning microscopy with X-ray microanalyser (SEM/EDS), Raman and FTIR microspectroscopies were applied. Observation of the black layer under the PLM suggests that we deal with an opaque, isotropic layer, purposely put on leather-hard, burnished surface of a pot. No traces of organic substances that might have modified a pot surface before painting were detected. The black layer coats the pot with a continuous 0.2-0.4 μm thick layer. The black layer must have been applied while warm or hot. It is recognized that the black layer is a true painting layer. Spectroscopic analyses (Raman and FTIR) point that birch tar or a birch-pine tar had been applied. Carbon black should be definitely excluded. The analyzed organic substance is structurally ordered in various degrees, due to varying temperature influence. Some Raman spectra reveal, in second-order region of the spectrum (>2000 cm(-1)), the graphite presence. Scarce points reveal the presence of inorganic admixtures: clay minerals, feldspars and quartz. The next question is: Is it an organic paint or a carbon-based, "mixed" paint? Inorganic admixtures are only casual. Relatively high concentration of alumina is expected to have appeared due to aluminum mobility in acidic environment and this was provided by organic tar/pitch substances. Phosphorus (usually with calcium) mostly concentrates together with clay minerals. Thus, hypothesis on bone powder or ash addition to tar/pitch should be excluded. Some elements may originate not only from inorganic substances but also from wood ashes.     

Hybrid heterojunction solar cell based on organic-inorganic silicon nanowire array architecture

Silicon nanowire arrays (SiNWs) on a planar silicon wafer can be fabricated by a simple metal-assisted wet chemical etching method. They can offer an excellent light harvesting capability through light scattering and trapping. In this work, we demonstrated that the organic-inorganic solar cell based on hybrid composites of conjugated molecules and SiNWs on a planar substrate yielded an excellent power conversion efficiency (PCE) of 9.70%. The high efficiency was ascribed to two aspects: one was the improvement of the light absorption by SiNWs structure on the planar components; the other was the enhancement of charge extraction efficiency, resulting from the novel top contact by forming a thin organic layer shell around the individual silicon nanowire. On the contrary, the sole planar junction solar cell only exhibited a PCE of 6.01%, due to the lower light trapping capability and the less hole extraction efficiency. It indicated that both the SiNWs structure and the thin organic layer top contact were critical to achieve a high performance organic/silicon solar cell.     

Efficient deep blue OLEDs with extremely low efficiency roll-off at high brightness based on phenanthroimidazole derivatives

Local emissions located on the PI moiety and anthracene moiety play a key role in alleviating efficiency roll-off at high Brightness in non-doped and doped devices.     

Relation between membrane characteristics and performance in nanofiltration

The performance of commercial membranes during nanofiltration of aqueous solutions containing dissolved uncharged or charged organic components, was studied on the basis of membrane characteristics by means of multiple linear regression.

The membrane characteristics studied were surface hydrophobicity, surface roughness, surface charge, molecular weight cut-off (MWCO), permeability and porosity of the top layer (expressed as the volume fraction of small and large pores, determined by Positron Annihilation Lifetime Spectroscopy). Filtration and adsorption experiments were performed in the presence of various components, which differ in molecular mass, hydrophobicity and (in the case of charged organic components) in charge.

It was concluded that in order to minimize fouling, the membrane should have a low volume fraction of small pores in the top layer. When the organic components are charged, a membrane with a large surface charge and a high hydrophilicity is also favourable. Not only the membrane, but also the feed characteristics have an influence on fouling: the best results during nanofiltration of dissolved uncharged or charged components were obtained with hydrophilic or negatively charged components, respectively. Dissolved organic components were the best retained by membranes with a low MWCO. In addition, uncharged organic components should be hydrophilic and small to obtain a high retention and minimal flux decline, while the interplay between membrane and component charge is crucial during filtration of dissolved charged organic components.     

Charge transport polymers for organic electroluminescent devices

Triple-layer-type organic electroluminescent devices were fabricated using charge-transporting poly(N-vinylcarbazole) (PVK) as a hole-transporting emitter layer. Electron-transporting layers consisting of a triazole derivative (TAZ) and an aluminum complex (Alq) layer were used to maximize the carrier recombination efficiency. The EL device with a structure of glass substrate/indium-tinoxide/PVK/TAZ/AIq/Mg:Ag showed bright blue emission from the PVK layer with a luminance of over 700 cd/m². The emission color was tuned to a desirable color in the visible region through doping the PVK layer with fluorescent dyes. Bright white emission, in particular, was obtained for the first time at a high luminance level of over 3000 cd/m² by using three kinds of fluorescent dyes each emitting red, green or blue.     

C_(60)与MoO_3混合材料做空穴注入层的单层有机电致发光器件

我们制备研究了基于结构为氧化铟锡(ITO)/C_(60)(1.2nm):MoO_3(0.4nm)/1,3,5-三(1-苯基-1H-苯并咪唑-2-基)苯(TPBi):三(2-苯基吡啶)铱[Ir(ppy)_3](33%,90 nm)/LiF (0.7 nm)/Al (120 nm)的高效绿色磷光单层有机发光二极管(OLED)。分别将C_(60),MoO_3与C_(60):MoO_3混合物作为空穴注入层(HIL)作为对比。TPBi在发光层中起着主体以及电子传输材料的双重作用。在使用电子传输型主体的单层OLED中,空穴注入层性质对于调节电子/空穴注入以获得电荷载流子传输平衡起重要作用。因此,适当调节空穴注入层是实现高效单层OLED的关键因素。由于MoO_3较大的电子亲和能(6.37 eV)会诱导电子从C_(60)的最高占据分子轨道(HOMO)能级转移至MoO_3,从而形成C_(60)阳离子,并使得Mo元素的价态从+6降至+5,C_(60):MoO_3混合就可以较好的调节空穴注入性质。最终实现最大电流效率为35.88 cd·A~(-1)的单层有机发光器件。     

Single drop liquid-liquid-liquid microextraction of methamphetamine and amphetamine in urine

Single drop liquid-liquid-liquid microextraction (LLLME) combined with high performance liquid chromatography (HPLC)-UV detection was investigated for the determination of a popular drug of abuse, methamphetamine (MAP), and its major metabolite, amphetamine (AP), in urine samples. The target compounds were extracted from NaOH modified sample solution to a thin layer of organic solvent membrane, and back-extracted to an acidic acceptor drop suspended on the tip of a 50-microL HPLC syringe in the aforementioned organic layer. This syringe was also used for direct injection after extraction. Factors affecting extraction efficiency were studied. At optimal conditions, the overall enrichment factor (EF) was 500-fold for AP and 730-fold for MAP, respectively. The method exhibited a wide linear range (1.0-1500 microg/L), low detection limit (0.5 microg/L), and good repeatability (RSD<5.0%) for both analytes. The feasibility of the method was demonstrated by the analysis of human urine samples.     

Applications of Ytterbium in organic light-emitting devices as high performance and transparent electrodes

Potential applications of Ytterbium (Yb) in cathode system for organic optoelectronic/electronic devices were explored in NPB/Alq₃ based bi-layer organic light-emitting devices (OLEDs). When a thin (14.5 nm) Yb layer capped with a thicker (200 nm) Ag layer was used as the cathode, the OLEDs show enhanced electron injection over those using the standard Mg:Ag cathode. Performance of the OLEDs with the Yb/Ag cathode is comparable to that using LiF/Al cathode. Interestingly, we also found that Yb can also be used to prepare a highly transparent cathode by co-evaporating Yb and Ag to form a Yb:Ag alloy electrode. Surface-emitting (or top emission) and transparent (emission from both surfaces) OLEDs with low turn-on voltage (3.75 V) and high efficiency were prepared with the Yb:Ag electrode.     

有机物单层分散在相关材料制备中的应用

与无机氧化物和盐类在载体表面自发单层分散相类似, 许多有机物也可以在载体表面自发单层分散.有机物在载体表面单层分散行为和分散后的存在状态与有机物分子形状和结构特点及载体表面性质和孔结构有关. 利用有机物在载体表面的单层分散, 可以设计制备具有优异性能的材料. 本文简要综述了近年来这方面研究工作取得的相关进展, 主要介绍了有机物单层分散在碳/氧化物复合物、氧化物和薄壁中孔碳材料的制备和织构调控方面的一些应用实例. 单层分散的有机物热分解后可在载体表面形成均匀的薄碳层, 以无机多孔氧化物为载体可制备出包覆均匀碳薄层的碳/氧化物复合物, 这种碳/氧化物复合物在染料吸附、催化剂载体和光催化方面显现出好的性能. 以溶胶-凝胶法制备氧化物时, 分散的有机物可以隔离溶胶颗粒, 从而制备出高比表面积的氧化物并可对孔容进行调控, 以此方法制备的γ-氧化铝比表面积可达506 m²·g^-1. 在惰性气氛中加热上述碳/氧化物复合物, 碳层可抑制氧化物的相变; 而在氧气中, 碳层燃烧发热会促进相变, 由此可快速制备超细α-氧化铝. 包覆均匀碳薄层的氧化物载体对碳起支撑作用, 在将氧化物溶解去除后, 可便捷制得高比表面积、大孔容、高中孔率的薄壁中孔碳材料, 碳材料的形貌、孔径分布等可通过选用不同织构的氧化物载体进行调控.     

薄层软刻蚀法制备PMMA微图案结构

对现有的软刻蚀方法提出了改进,让其与压印技术及毛细力刻蚀技术相结合形成一种薄层软刻蚀技术,并以这种技术制备出PMMA薄膜微图案化结构.在30 mm/h的拉膜速度以及弹性印章表面图形深度确定不变的情况下,PMMA流体能够完全填充到弹性印章的微通道中,SEM和光学显微镜照片证明得到的PMMA微图案是相互分离的.因此,薄层软刻蚀技术可以克服普通微模塑方法制备分离图形困难和纳米压印技术中需要使用巨大机械压力的缺点.     

Nonlinear behavior during semi-quantitative analysis of thin organic layers by laser desorption mass spectrometry

Characterization of the surface coverage and thickness of an organic thin film is particularly important in organic electronics and optoelectronics. For surface coverage down to the submonolayer level there is still a need for characterization methods which are easily applicable. In the present work we report on the evaluation of laser desorption mass spectrometry (LD-MS) for its use in thickness determination of organic thin films. Whereas LD-MS is well established as a soft ionization method for small molecules, its capability for use in quantitative analysis is nearly unexplored. We carried out experiments with two different molecules, 7,7,8,8-tetracyanoquinodimethane and hexabenzocoronene, in a series of experiments with increasing surface coverage. The obtained data were analyzed by plotting the LD signal intensities versus the relative layer thickness and they reveal a nonlinear behavior, which can be classified into regions of different desorption/ionization efficiencies. Visualization by atomic force microscopy reveals that the first efficiency change corresponds to the transition between incomplete and complete coverage of the metal surface by analyte molecules. A second transition is observed at high layer thickness where the signal intensity stays constant, independent of further thickness increments, and this is attributed to the limited penetration depth of the laser beam. The intermediate region between the two transitions shows a linear behavior and can thus be used for semi-quantitative thickness measurements. The efficiency change observed at the point of complete surface coverage is particularly useful for thin layer preparation of organic field effect transistors, where complete surface coverage is a minimum requirement.     

The role of the organic layer functionalization in the formation of silicon/organic layer/metal junctions with coinage metals

The design of silicon/alkyl layer/metal junctions for the formation of optimal top metal contacts requires knowledge of the mechanistic and energetic aspects of the interactions of metal atoms with the modified surface. This involves (a) the interaction of the metal with the terminal groups of the organic layer, (b) the diffusion of metal atoms through the organic layer and (c) the reactions of metal atoms with the silicon surface atoms. The diffusion through the monolayer and the metal catalyzed breakage of Si-C bonds must be avoided to obtain high quality junctions. In this work, we performed a comprehensive density functional theory investigation to identify the reaction pathways of all these processes. In the absence of a reactive terminal group, gold atoms may penetrate through a compact alkyl monolayer on Si(111) with no energy barrier. However, the presence of thiol terminal groups introduces a high energy barrier which blocks the diffusion of metals into the monolayer. The diffusion barriers increase in the order Ag < Au < Cu and correlate with the stability of metal-thiolate complexes whereas the barriers for the formation of metal silicides increase in the order Cu < Au < Ag in correlation with the increasing metallic radii. The reactivity of gold clusters with functionalized Si(111) surfaces was also investigated. Metal silicide formation can only be avoided by a compact monolayer terminated by a reactive functional group. The mechanistic and energetic picture obtained in this work contributes to understanding of the factors that influence the quality of top metal contacts during the formation of silicon/organic layer/metal junctions.     

高效液相色谱-电化学检测法测定脑组织中鬼臼甲叉甙

报道了用甲醇－水－乙酸（５６４１３,体积比）为流动相,在ＨｙｐｅｒｓｉｌＯＤＳ柱上以愈创木酚甘油醚为内标,采用电化学检测器（ＥＣＤ）测定人体脑组织中鬼臼甲叉甙含量。回收率９２．８７％,最低检测浓度为０．１ｍｇ／Ｌ,鬼臼甲叉甙在０．１～１０．０ｍｇ／Ｌ范围内呈线性,工作电压０．７０Ｖ。同时还对脑瘤患者脑组织中正常部位和肿瘤部分中鬼臼甲叉甙含量进行了测定。     

Recent Advances in Preparation and Applications of Magnetic Framework Composites

Metal‐organic frameworks (MOFs) offer ample characteristics, such as easy synthesis, high surface area, tunable porosities, open metal sites, post‐synthesis modification, making them attractive for diverse applications. Since magnetic particles can be positioned and separated by a magnetic field, magnetic framework composites (MFCs) have attracted tremendous attention. In this review, different methods of preparing MFCs, including direct mixing, in‐situ growth of magnetic particles, embedding method, layer‐by‐layer growth method and encapsulation method, will be discussed in detail. Moreover, their applications in catalysis, adsorption, biomedicine and sensing will also be introduced.     

Synthesis,Characterization and Electrorheological Properties of Polyindene/Kaolinite Composites

In this study, synthesis, characterization and electrorheological (ER) properties of polyindene (PIN) and polyindene/kaolinite composites were carried out by cationic radical polymerization using FeCl₃ as the oxidizing agent. The homopolymer and composites, containing different amounts of PIN were characterized by FTIR spectroscopy, thermo‐gravimetric (TGA) analyses, scanning electron microscopy (SEM) and dynamic light scattering (DLS) methods. The conductivity and dielectric properties of PIN and PIN/kaolinite composites were determined. Suspensions of PIN and PIN/kaolinite composites were prepared in silicone oil (SO), at a series of concentrations (c=5–25 m/m %). The effects of concentration, shear rate, electric field strength, frequency, temperature and promoter on ER activities of suspensions were investigated.     

Self-assembled monolayers for interface engineering in polymer solar cells

Polymer solar cell (PSC) has been developed vastly in the past decade due to the advantages of low cost, lightweight, mechanical flexibility, versatility of chemical design and synthesis, semitransparency, and solution processing. The performance and lifetime of PSCs are highly dependent on the properties of both active materials and their interfaces. The combination of the versatility of organic chemistry and the multitude of well-understood ligand–metal interactions allows self-assembled monolayers (SAMs) of organic molecules to direct control over the electronic and chemical properties at the inorganic–organic interfaces. Thus, SAMs are an attractive pathway to reconcile interfaces with tunable interface properties in PSCs. Hence, this review describes the application of SAMs in PSCs at different interfaces. First, SAMs as alternatives of traditional transporting materials to reduce the barrier at indium tin oxide (ITO)/active layer interface due to the ability of tuning work function of ITO electrode are discussed. Second, the modifications of metal oxide by SAMs to control the electrical contacts at transporting layer/active layer interface are described. Third, tailoring the properties of the donor/acceptor interface by SAMs to improve the performance of PSCs are summarized. Finally, perspectives and challenges are pointed out for developing highly stable and high-performance PSCs by applying SAMs.     

Investigating dysregulated pathways in Staphylococcus aureus (SA) exposed macrophages based on pathway interaction network

ObjectiveThis work aimed to identify dysregulated pathways for Staphylococcus aureus (SA) exposed macrophages based on pathway interaction network (PIN).MethodsThe inference of dysregulated pathways was comprised of four steps: preparing gene expression data, protein–protein interaction (PPI) data and pathway data; constructing a PIN dependent on the data and Pearson correlation coefficient (PCC); selecting seed pathway from PIN by computing activity score for each pathway according to principal component analysis (PCA) method; and investigating dysregulated pathways in a minimum set of pathways (MSP) utilizing seed pathway and the area under the receiver operating characteristics curve (AUC) index implemented in support vector machines (SVM) model.ResultsA total of 20,545 genes, 449,833 interactions and 1189 pathways were obtained in the gene expression data, PPI data and pathway data, respectively. The PIN was consisted of 8388 interactions and 1189 nodes, and Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins was identified as the seed pathway. Finally, 15 dysregulated pathways in MSP (AUC = 0.999) were obtained for SA infected samples, such as Respiratory electron transport and DNA Replication.ConclusionsWe have identified 15 dysregulated pathways for SA infected macrophages based on PIN. The findings might provide potential biomarkers for early detection and therapy of SA infection, and give insights to reveal the molecular mechanism underlying SA infections. However, how these dysregulated pathways worked together still needs to be studied.