THE HADAMARD INEQUALITY FOR CONVEX FUNCTION VIA FRACTIONAL INTEGRALS

In this paper, we establish several inequalities for some differantiable mappings that are connected with the Riemann-Liouville fractional integrals. The analysis used in the proofs is fairly elementar...     

Improved methods for urinary atrazine mercapturate analysis--assessment of an enzyme-linked immunosorbent assay (ELISA) and a novel liquid chromatography-mass spectrometry (LC-MS) method utilizing online solid phase extraction (SPE)

Elimination of interfering substances in urine by solid phase extraction (SPE) prior to analysis resulted in 10-fold improvement in the sensitivity of atrazine mercapturate (AM) enzyme-linked immunosorbent assay (ELISA) compared to previous reports. Of the two tested SPE systems, Oasis^® HLB and MCX, the mixed-mode MCX gave good recoveries (82%) of AM in spiked samples measured by ELISA, whereas the reverse-phase HLB phase was not compatible with the immunochemical method. At relatively high concentrations of urinary AM (>20 ng mL⁻¹), sample dilution was effective enough for the elimination of interfering substances. The new liquid chromatography-mass spectrometry (LC-MS) method developed for AM utilizes online-SPE with Oasis^® HLB, column switching and a stable-isotope internal standard. The limit of quantification (0.05 ng mL⁻¹) indicates improved sensitivity compared with most previously published LC-MS methods for AM. Validation of all three methods, LC-MS, ELISA + SPE and ELISA + dilution with spiked urine samples showed good correlation between the known and measured concentrations with R² values of 0.996, 0.957 and 0.961, respectively. When a set (n = 70 plus 12 blind duplicates) of urine samples from farmers exposed to atrazine was analyzed, there was a good agreement (R² = 0.917) between the log normalized data obtained by ELISA + SPE and LC-MS. High correlation among the data obtained by the two tested methods and the LC-MS method by the Center of Disease Control and Prevention (CDC), together with low variability among the blind duplicates, suggests that both methods reported here would be suitable for the analysis of urinary AM as a biomarker for human exposure of atrazine.     

Use of intein-directed peptide biosynthesis to improve serum stability and bioactivity of a gelatinase inhibitory peptide

Screening of phage display libraries allows rapid identification of peptides binding to a target. However, functional analysis of the phage sequences and their reproduction as soluble and stable peptides are often the most time-consuming part in the screening. We have used here intein-based peptide biosynthesis to produce a phage-display derived gelatinase inhibitory peptide CTTHWGFTLC and to identify the critical residues for gelatinase inhibitory activity by performing alanine-scanning mutagenesis. By biosynthetic incorporation of 5-fluorotryptophan, we obtained an inhibitor of MMP-2 and MMP-9 gelatinases that showed a 6-fold enhancement in serum stability in comparison to the wild-type peptide. The new peptide also had an improved ability to inhibit tumor cell migration. These studies indicate the utility of intein methodology for synthesis and design of peptides obtained by phage display.     

在硅胶表面制备牛血红蛋白分子印迹聚合物

采用表面印迹法, 以乙烯基三甲氧基硅烷修饰的硅胶为载体, 丙烯酰胺为功能单体, N,N-亚甲基双丙烯酰胺为交联剂, 并将改性聚乙烯醇(PVA)作为辅助识别聚合物链(ARPCs)引入聚合体系中, 制备了牛血红蛋白分子印迹聚合物(MIP). 实验使用红外光谱分析了改性PVA的结构特征, 用扫描电镜(SEM)观察MIP的表面形貌, 考察了ARPCs的含量对MIP吸附性能的影响. 吸附动力学实验研究表明, 聚合体系中ARPCs的引入使MIP对模板牛血红蛋白(BHb)的吸附量明显提高|十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)结果显示, MIP对BHb的特异性吸附能力明显提高.     

TRANSFER MECHANISM OF QUININE DRUG ACROSS THE OIL/WATER (O/W) INTERFACE

The transfer phenomena of quinine drug at the aqueous 1,2- dichloroethane (DCE)interface have been studied by the current- scanning polarography. The relationships be-tween the wave height and pH of aqueous phase, concentration of quinine as well as therate of water drop are discussed. The effect of supporting electrolyte, buffer solution andthe nature of organic solvent on the polarographic wave is studied. The transfer char-acteristics of quinine in aqueous phase and in organic phase are compared, The mono- pro-tonated and diprotonated quinines can both transfer at the interface so as to produce twopolarographic waves. The transfer process of quinine at the interface is simultaneouslycontrolled by diffusion and reestablishment of the disturbed protonated equilibrium ofquinine. A further investigation is made by chronopotentiometry. On the basis of thetheoretical analysis, the formulae of the limiting current are derived and discussed. Thetheoretical results are in agreement with the experimental ones.     

Gamma induced changes in Makrofol/CdSe nanocomposite films

We applied an ex-situ casting procedure to prepare a nanocomposite (NCP) from Makrofol polycarbonate (PC) and CdSe nanoparticles. The CdSe nanoparticles were prepared by a thermolysis procedure in the presence of N₂ gas flow. Rietveld refinement of x-ray data illustrated that the CdSe adopts a cubic zinc blend structure of 6.057 Å lattice parameter and 2 nm typical grain size. Samples from the prepared NCP were exposed to γ dosages (20 kGy-250 kGy). The modifications induced in the NCP films owing to γ dosages have been studied. The γ irradiation (50 kGy-250 kGy) causes crosslinks that reduce the optical bandgap from 4.15 eV to 3.81 eV, associated with an increase in dielectric parameters and refractive index. This is attributed to an increase in the mass fraction of the disordered regions as specified by x-ray diffraction. The PC-CdSe NCP was found to have a reaction to color modification which makes it suitable for saleable reproduction on a printing press.