Biofunctional magnetic nanoparticles as contrast agents for magnetic resonance imaging of pancreas cancer

We report on the fabrication and characterization of biofunctional magnetic nanoparticles as contrast agents for magnetic resonance imaging. The anti-cancer antigen 19-9 monoclonal antibody (a cancer-targeting antibody) was conjugated onto the magnetic contrast agents in an effort to detect pancreatic tumor. The structure, size, morphology and magnetic property of the biofunctional magnetic nanoparticles are characterized systematically by means of transmission electron microscopy and X-ray diffractometry. Furthermore, the interaction between the nanoparticles and pancreas cancers cells are investigated by atomic force microscope and transmission electron microscopy. Magnetic resonance imaging demonstrates that the conjugated nanoparticles can effectively target cancer cells both in vitro and in vivo, suggesting that they potentially can be used as contrast agents for magnetic resonance imaging of pancreas cancer.     

A study on the degradation of methamidophos in the presence of nano-TiO<Subscript>2</Subscript> catalyst doped with Re

A new Re-doped nano-TiO₂ photocatalyst was synthesized by immersion method. The novel doped nano-TiO₂ photocatalyst utilizing visible light was firstly prepared. The doped nano-TiO₂ powder was charactered by XRD, FTIR, UV-Vis, and its photocatalytic activity was tested through the photocatalytic degradation of methamidophos as a model compound under ultraviolet irradiating and in sunlight, respectively. In order to compare the photocatalytic activities, the same experiment was carried out for undoped nano-TiO₂. The degradation ratio of methamidophos in the presence of doped nano-TiO₂ reached 64.40% under sunlight for 12 h, which was 2.64% in the presence of undoped nano-TiO₂. The degradation ratio of methamidophos in the presence of doped nanoTiO₂ reached 90.39% under UV irradiationat 2.5 h, which was 51.29% in the presence of undoped nano-TiO₂. All the results show that the doped TiO₂ is a promising photocatalyst using sunlight for treating the organophosphorous pesticide wastewater. The article is published in the original.     

Selective on-line serum peptide extraction and multidimensional separation by coupling a restricted-access material-based capillary trap column with nanoliquid chromatography–tandem mass spectrometry

As the serum peptidome gets increasing attention for biomarker discovery, one of the important issues is how to efficiently extract the peptides from highly complex human serum for peptidome analysis. Here we developed a fully automated platform for direct injection, on-line extraction, multidimensional separation and MS detection of peptides present in human serum. A capillary SPE column packed with a novel mix mode restricted access material (RAM) exhibiting strong cation exchange and size exclusion chromatography (SCX/SEC) properties were coupled with a nanoliquid chromatography–mass spectrometry (nanoLC-MS) system. The capillary SPE column excludes the high abundant serum proteins such as HSA by size exclusion chromatography and simultaneously extracts the low molecular weight peptides by binding to sulfonic acid residues. Subsequently, the trapped peptides are eluted to a capillary LC column packed with a RP-C18 stationary phase. After injection of only 2 μL human serum to the one-dimensional nanoLC-MS system around 400 peptides could be identified. When conducting a multidimensional separation, the described SCX/SEC/RP-MS platform allows the separation and identification of 1286 peptides present in human serum by the injection and on-line processing of 20 μL human serum sample.     

Two bis-[1-(aryliminomethyleny)-2-oxy-naphthalen] nickel catalysts for the polymerization of methyl methacrylate

Two bis-(1-arylliminomethylenyl-2-oxy-naphthalen) nickel complexes (aryl = 2-methylphenyl, complex 1; aryl = 2,6-diisoproylphenyl, complex 2) were reacted with alkylaluminium in presence of equimolar PPh₃ and tested as catalysts in methyl methacrylate (MMA) polymerization. The two nickel catalysts can initiate polymerization of MMA with good to high activity, the highest activity reaching 1.1 × 10⁵ g PMMA/(mol Ni · h) by less bulky complex 1 at 0.8 mol/L of MMA, 400 of Al/Ni ratio and 0 °C. In addition, the structures of nickel complexes and polymerization conditions, such as monomer concentration, polymerization temperature and Al/Ni molar ratio on catalytic activity of polymerization have great influences on catalytic activity and product properties.     

High-efficiency solution processable electrophosphorescent iridium complexes bearing polyphenylphenyl dendron ligands

We report the synthesis and electrophosphorescent behavior of a series of novel iridium complex materials (Complexes A–F), which are composed of ligands bearing polyphenylphenyl dendron groups and acetylacetonate. Yellow to saturated red organic light-emitting diodes (OLEDs) based on these newly developed Ir complexes were fabricated through solution process by doping the complex materials into polyvinyl carbazole (PVK)/2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) matrices. The emission wavelengths of the materials could be effectively tuned from 549 nm to 640 nm by changing the conjugation of the ligands either through incorporating additional aromatic segment (e.g. phenyl or fluorenyl group) onto the basic dendron ligand or fusing two of the phenyl rings on the polyphenylphenyl dendron group. High performance devices with the configuration of ITO/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS) (50 nm)/PVK:PBD (40%):Ir complex (6%) (70 nm)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) (12 nm)/Alq₃ (20 nm)/Mg:Ag (150 nm) have been demonstrated. For example, when Complex B was used as the emissive layer, maximum current efficiency of 34.0 cd/A and external quantum efficiency of 10.3% have been achieved. When 1,3,5-tris(N-phenylbenzimidazol-2-yl) benzene (TPBI) was used as the block layer, the efficiencies can be further improved to 46.3 cd/A and 13.9%, respectively. These solution processed OLED devices demonstrated quite stable EL efficiencies over a large range of current density, which indicated that triplet–triplet annihilation in electrophosphorescence could be effectively suppressed by incorporation of the polyphenylphenyl dendron structure into iridium complexes.     

A Sensitive LC–ESI–MS–MS Method for the Determination of Huperzine A in Human Plasma: Method and Clinical Applications

A sensitive and specific liquid chromatography–electrospray ionization–tandem mass spectrometry method has been developed and validated for the quantification of huperzine A in human plasma. After the addition of trimetazidine, the internal standard (IS) and sodium hydroxide, plasma samples were extracted using 5 mL ethyl acetate. The compounds were separated on an Agilent Zorbax SB C₁₈ column (100 mm × 2.1 mm ID, dp 3.5 μm) using an elution system of 10 mM ammonium acetate solution–methanol–formic acid (18:82:0.1, v/v) as the mobile phase. The quantification of target compounds was obtained by using multiple reaction monitoring (MRM) transitions: m/z 243.1, 210.1 and 267.2, 166.0 were measured in positive mode for huperzine A and IS. Linearity was established for the range of concentrations 0.01–4.0 ng mL^?1 with a coefficient of correlation (r) of 0.9991. The lower limit of quantification (LLOQ) was identifiable and reproducible at 0.01 ng mL^?1. The method has been successfully applied to study the pharmacokinetics of huperzine A in healthy male Chinese volunteers.     

Analysis of fatty acids in sputum from patients with pulmonary tuberculosis using gas chromatography–mass spectrometry preceded by solid-phase microextraction and post-derivatization on the fiber

A method based on solid-phase microextraction (SPME) and post-derivatization on the fiber coupled to gas chromatography–mass spectrometry (GC–MS) was developed for the analysis of fatty acids in sputum from patients with pulmonary tuberculosis. The sputum specimens were digested, hydrolyzed, extracted, derivertized, injected and analyzed without cultivation or isolation of the microorganism. Under optimized conditions, the relative standard deviations (RSD, n = 5) for all analytes were below 17% and the limits of detection varied from 1.68 (C_24:0) to 150.4 μg L⁻¹ (C_12:0). Good linearity was observed for all the fatty acids studied except for C_12:0 within a wide concentration range of three orders of magnitudes with the correlation coefficients ranging from 0.91 (C_24:0) to 0.99 (C_14:0). Fatty acids in sputum specimens from 21 persons were directly analyzed using the proposed method. The results show that in all the sputum specimens from patients, who were clinically diagnosed with tuberculosis (TB), tuberculosis stearic acid (TBSA) was detected, while in all the sputum samples from persons without TB, TBSA was not found. The possibility of using the proposed method to detect mycobacterium tuberculosis (MTB) via the identification of TBSA in sputum was discussed. The comparison with other methods including sputum culture and microscopy of direct smears indicated that the proposed method is fast and sensitive for the analysis of fatty acids in sputum and offers an alternative for the detection of MTB in sputum.     

火花直读光谱法对铝合金中各元素含量测量结果的不确定度评定

分析了火花直读光谱法测定铝合金中Si、Fe、Cu、Mg、Mn、Zn、Cr、Ti元素含量测量结果的不确定度来源,对不确定度分量进行了评定与计算,Si、Fe、Cu、Mg、Mn、Zn、Cr、Ti测量结果的相对扩展不确定度分别为2. 9%、2. 5%、2. 6%、2. 7%、2. 6%、2. 6%、2. 5%、2. 7%(包含因子k均为2).     

Synthesis, crystal and band structures, and optical properties of a new supramolecular complex: [Hg6Sb4](InBr6)Br

A new supramolecular complex [Hg₆Sb₄](InBr₆)Br (1) has been prepared by the solid-state reaction of HgBr₂ with elemental In and Sb at 450 °C. The crystal structure of 1 features a three-dimensional [Hg₆Sb₄]⁴⁺ framework with cavities of two different sizes occupied by different kinds of guest anions. The bigger cavities are filled with the octahedral InBr₆³⁻ ions, while the smaller cavities trap Br⁻ ions. The optical properties were investigated in terms of the diffuse reflectance and infrared spectra. The electronic band structure along with density of states (DOS) calculated by DFT method indicates that the present compound is semiconductor, and the optical absorption is mainly originated from the charge transitions from Sb-5p and Br-4p to In-5s and Hg-6s states.