Genome-wide computational analyses of microRNAs and their targets from Canis familiaris

By computational analyses, we identified 357 miRNA candidates from Canis familiaris genome, among which 300 are homology of characterized human miRNAs, the remains are not reported in any other animal. Of the 357 miRNA genes, 142 are organized into 53 clusters, and two clusters locate in the paternally imprinted region. These dog miRNAs may regulate more than 800 possible targets, which are involved in a wide range of cellular processes. Remarkably, miR-186 resides in the eighth intron of its target gene in the same orientation, suggesting a feedback regulation of miRNA on its host gene.     

Synthesis of a novel fluorescent probe based on acridine skeleton used for sensitive determination of DNA

In this study, a novel fluorescent probe of acridine derivative N-((N-(2-dimethylamino)ethyl)acridine-4-carboxamide)-alpha-alanine (N-(ACR-4-CA)-alpha-ALA) was synthesized. The structure of the new compound was characterized by (1)H NMR, MS, elemental analysis, fluorescent and ultraviolet spectra. It was found that DNA had the ability to quench the fluorescence of N-(ACR-4-CA)-alpha-ALA, and the quenched intensity of fluorescence was proportional to the concentration of DNA. A method for DNA determination based on the quenching fluorescence (lambda(ex) = 260 nm, lambda(em) = 451 nm) of N-(ACR-4-CA)-alpha-ALA was established. Under optimal conditions, the linear range is 0.05-2.0 microg mL(-1) for both fish semen (fsDNA) and calf thymus DNA (ctDNA). The corresponding determination limits are 9.1 ng mL(-1) for fsDNA and 8.7 ng mL(-1) for ctDNA, respectively. The results suggested that the interaction mode between N-(ACR-4-CA)-alpha-ALA and DNA was intercalative binding. The intrinsic binding constant was determined and the result showed a large binding constant of N-(ACR-4-CA)-alpha-ALA with DNA.     

Determination of trace chlorine dioxide based on the plasmon resonance scattering of silver nanoparticles

A plasmon resonance scattering (PRS) method for chlorine dioxide is reported based on the oxidization of silver nanoparticles (NPs) by it, in pH 9.1 ammonia-ammonium nitrate buffer solutions. Silver NPs exhibit strong PRS signals at 470nm, and can be oxidized by ClO(2), which results in PRS quenching at 470nm. It was found that the PRS quenching intensity is proportional to the concentration of chlorine dioxide over the range of 0.0011-0.185microg/mL, with a detection limit (3sigma) of 0.00050microg/mL and the correlation coefficient of 0.9995. The method is simple, rapid and cost effective. It was applied to the determination of chlorine dioxide in drinking water, with satisfactory results.     

利用荧光响应的台式生化需氧量传感仪器的研制

利用氧荧光猝灭原理研制了台式生化需氧量(BOD)传感检测仪器。仪器的工作系统由检测系统和软件系统两部分组成。该检测仪操作简便,检测快速,可进行海水BOD含量的现场检测。仪器的性能考察结果表明,在0.5~50mg/L浓度范围内BOD响应的线性相关系数为0.9978。实际海水样品的检测结果显示,仪器对海水样品的平行测定结果相对标准偏差小于±5%,并且与标准五日生化需氧量(BOD5)方法所获得的数值的相关性为0.99。仪器具有较长的使用寿命和良好的稳定性。     

基于主客体作用的多重刺激响应型超分子水凝胶的制备及性能

利用单-6-脱氧-6-氨基-β-环糊精(β-CDNH2)与双二茂铁亚甲基丁二胺季铵盐(FBI)之间的主-客体作用制备了一种性能特异的超分子水凝胶, 该水凝胶具有显著的热可逆性和pH刺激响应性, (NH4)2Ce(NO3)6的引入导致凝胶液化, 体系的颜色也由淡黄色转变为墨绿色. 扫描电镜结果表明, 在凝胶中胶凝剂β-CDNH2和FBI结合组成以带状纤维为特征的三维网络结构. 1H NMR, FTIR, XRD以及循环伏安等表征结果表明, FBI与β-CDNH2间的主客体包结作用和β-CDNH2分子间的氢键作用是凝胶形成并能稳定存在的主要原因.     

Distinct Hydrogen-bonded MII(H2O)8 Clusters as Second Building Units for 1-D, 2-D and 3-D Supramolecular Architectures (M = Cobalt and Nickel)

Two mononuclear metal-organic complexes, [Co(Hmpdc)2(H2O)4]·4H2O 1 and [Ni(Hfmpdc)2(H2O)4]·6H2O 2, were prepared from 2,6-dimethylpyridine-3,5-dicarboxylic acid (H2mpdc) and 4-furyl-2,6-dimethylpyridine-3,5-dicarboxylic acid (H2fmpdc) with M(NO3)2 salts, respectively, and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, and photoluminescent measurement. Complex 1 crystallizes in triclinic, space group P with a = 7.634(5), b = 8.695(5), c = 10.757(6)(A), α = 69.647(7), β = 69.957(8), γ = 83.733(7)°, V = 628.9(7)(A)3, Dc = 1. 561 g/cm3, μ(MoKα) = 0.763 mm-1, F(000) = 309, Z = 1, the final R = 0.0553 and wR = 0.1469 for 1909 observed reflections (I > 2σ(I)). Complex 2 crystallizes in monoclinic, space group P21/n with a = 9.5934(16), b = 12.422(2), c = 14.826(3)(A), β = 105.201(2)°, V = 1705.0(5)(A)3, Dc = 1. 479 g/cm3, μ(MoKα) = 0.655 mm-1, F(000) = 796, Z = 2, the final R = 0.0351 and wR = 0.0889 for 2387 observed reflections (I > 2σ(I)). In the crystal structures of 1 and 2, diverse supramolecular motifs from 1-D chains/ladders to 3-D networks are constructed from corresponding distinct [MⅡ(H2O)8] ion clusters as the second building units, respectively. The solid state compounds of 1 and 2 show similar photoluminescent spectra with emission maximum at ca. 466 nm at room temperature.     

Distinct Hydrogen-bonded M^Ⅱ（H2O）8 Clusters as Second Building Units for 1-D, 2-D and 3-D Supramolecular Architectures （M = Cobalt and Nickel）

Two mononuclear metal-organic complexes, [Co（Hmpdc）2（H2O）4]·4H2O 1 and [Ni（Hfmpdc）2（H2O）4]·6H2O 2, were prepared from 2,6-dimethylpyridine-3,5-dicarboxylic acid （Hzmpdc） and 4-furyl-2,6-dimethylpyridine-3,5-dicarboxylic acid （H2fmpdc） with M（NO3）2 salts, respectively, and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, and photoluminescent measurement. Complex 1 crystallizes in triclinic, space group P1 with a = 7.634（5）, b = 8.695（5）, c = 10.757（6）A, α = 69.647（7）, β = 69.957（8）, γ = 83.733（7）°, V = 628.9（7）A^3, Dc = 1. 561 g/cm^3,μ（MoKa） = 0.763 mm^-1, F（000） = 309, Z = 1, the final R = 0.0553 and wR = 0.1469 for 1909 observed reflections （Ⅰ 〉 2σ（Ⅰ））. Complex 2 crystallizes in monoclinic, space group P21/n with a = 9.5934（16）, b = 12.422（2）, c = 14.826（3） A, β = 105.201（2）°, V = 1705.0（5）A3, Dc = 1. 479 g/cm^3,μ（MoKa） = 0.655 mm^-1, F（000） = 796, Z = 2, the final R= 0.0351 and wR = 0.0889 for 2387 obsevved reflections （Ⅰ 〉 2σ（Ⅰ））. In the crystal structures of 1 and 2, diverse supramolecular motifs from 1-D chains/ladders to 3-D networks are constructed from corresponding distinct [M^Ⅱ（H2O）8] ion clusters as the second building units, respectively. The solid state compounds of 1 and 2 show similar photoluminescent spectra with emission maximum at ca.     

Determination of pyrethroid pesticide residues in vegetables by solvent sublation followed by high-performance liquid chromatography

A novel method is developed for separating and enriching pyrethroid pesticides from vegetables by solvent sublation, and determination of the pyrethroids is performed by high-performance liquid chromatography (HPLC). The effects of organic solvent, pH of the solution, nitrogen flow rate, and sublation time on the sublation efficiency of pyrethroids are investigated in detail, and the optimal conditions of the solvent sublation are selected. The floated product of vegetables in the optimal conditions is determined by HPLC. The limit of detection values range from 1.4 microg/kg (for bifenthrin) to 4.2 microg/kg (for fenpropathin). The recoveries of spiked vegetable samples are from 85.7% to 110.4%, and relative standard deviation values are from 1.70% to 6.19%. The results are satisfactory.