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991.
We conjecture a strong property for the up and down maps U and D in an r-differential poset: DU + tI and UD + tI have Smith normal forms over . In particular, this would determine the integral structure of the maps U, D, UD, DU, including their ranks in any characteristic. As evidence, we prove the conjecture for the Young-Fibonacci lattice Y
F studied by Okada and its r-differential generalizations Z(r), as well as verifying many of its consequences for Young’s lattice Y and the r-differential Cartesian products Y
r
. 相似文献
992.
This paper describes approaches for large-volume sample stacking (LVSS) with an EOF pumpin CE for the determination of methotrexate (MTX) and its metabolites in human plasma. After pretreatment of plasma through a SPE cartridge, a large sample volume was loaded by hydrodynamic injection (3 psi, 70 s) into the capillary filled with phosphate buffer (70 mM, pH 6.0) containing 0.01% polyethylene oxide. Following removal of a large plug of sample matrix from the capillary using polarity switching (-25 kV), the separation of anionic analytes was subsequently performed without changing polarity again, achieving an improvement of sensitivity of around a 100-fold. The method was applied to therapeutic drug monitoring of MTX in one acute lymphoblastic leukemia patient. This study is one of very few applications showing the feasibility of LVSS in analysis of biological samples by CE. 相似文献
993.
994.
Zn2+ release from Zn and ZnO particles with different sizes in simulated uterine solution were investigated by absorbance measurements. The effects of pH and human serum albumin (HSA) on Zn2+ release were also studied. The morphology of Zn and ZnO particles was observed by scanning electron microscopy, and the corrosion products of zinc nanoparticles were analyzed by XRD. The results indicate that the maximum release ratios of Zn2+ from Zn and ZnO nanoparticles are higher than those from Zn and ZnO microparticles. Zn2+ release ratio depends not only on the pH of the simulated uterine solution but also the presence of human serum albumin. It decreases as the pH of the uterine solution increases. The trends of Zn2+ release ratios are almost the opposite for solutions with and without HSA. XRD analysis results indicate that zinc oxide is the main corrosion product of zinc particles. 相似文献
995.
de la Escosura-Muñiz A González-García MB Costa-García A 《Analytical and bioanalytical chemistry》2006,384(3):742-750
A new electroactive label has been used to monitor immunoassays in the determination of human serum albumin (HSA) using glassy-carbon
electrodes as supports for the immunological reactions. The label was a gold(I) complex, sodium aurothiomalate, which was
bound to rabbit IgG anti-human serum albumin (anti-HSA-Au). The HSA was adsorbed on the electrode surface and the immunological
reaction with gold-labelled anti-HSA was then performed for one hour by non-competitive or competitive procedures. The gold(I)
bound to the anti-HSA was electrodeposited in 0.1 mol L−1 HCl at −1.00 V for 5 min then oxidised in 0.1 mol L−1 H2SO4 solution at +1.40 V for 1 min. Silver electrodeposition at −0.14 V for 1 min followed by anodic stripping voltammetry were
then performed in aqueous 1.0 mol L−1 NH3–2.0×10−4 mol L−1 AgNO3. For both non-competitive and competitive formats, calibration plots in the ranges 5.0×10−10 to 1.0×10−8 mol L−1 and 1.0×10−10 to 1.0×10−9 mol L−1 HSA, respectively, with estimated detection limits of 1.5×10−10 mol L−1 (10 ng mL−1) and 1.0×10−10 mol L−1 (7 ng mL−1), respectively, were obtained. Levels of HSA in two healthy volunteer urine samples were also evaluated, using both immunoassay
formats. 相似文献
996.
Balaguer A Salvador A Chisvert A Meliá M Herráez M Díez O 《Analytical and bioanalytical chemistry》2006,385(7):1225-1232
Disodium phenyldibenzimidazole tetrasulfonate (PDT) is a new organic UV filter with hydrophilic properties used in modern
sunscreen spray formulations. The aim of this work was to develop and validate an analytical method that can be used to study
skin absorption of PDT from sunscreens. Results obtained in vitro for human skin showed a low level of absorption. The proposed
in vitro method employs a diffusion cell. Sunscreen lotion was applied onto pretreated human skin, which was then placed in
the cell. PDT was collected in a receptor liquid, the surface of which was in contact with the skin. The solutions obtained
were diluted appropriately and analyzed by liquid chromatography without any interference. The analytical features of chromatographic
determination with fluorimetic detection were suited to this analytical problem, since this method gave a limit of detection
of 1 ng ml−1. Phenol red (PR) was used as a marker to check the skin integrity, and a sensitive method based on sequential injection on-line
solid-phase extraction coupled with spectrophotometric detection was developed for determining this marker in the receptor
liquid in order to screen the cells.
相似文献
997.
Van Lierde V Chéry CC Roche N Monstrey S Moens L Vanhaecke F 《Analytical and bioanalytical chemistry》2006,384(2):378-384
Since the species that trigger chromium allergy are not yet known, it is important to gain more of an insight into the mechanism
of chromium transport through the skin and into the relationship between chromium allergy and chromium species. In vitro permeation
studies with porcine and human skin were performed using a Franz static diffusion cell. Investigations attempted to elucidate
(i) which Cr compounds are able to permeate through skin, (ii) the influence the Cr concentration in the donor solution has
on the Cr permeation, and (iii) the effect that the time of exposure to the donor solution has on Cr permeation. Capillary
electrophoresis hyphenated to inductively coupled plasma–sector field mass spectrometry (CE–ICP–SFMS) was used to separate
and quantify the Cr species in the receptor fluid. 50 mmol L−1 phosphate buffer (pH 2.5) was used for CE separation, and two different electrophoretic runs were carried out (in the positive
and negative modes). Pneumatic nebulization (PN)-ICP-SFMS was used in order to quantify the total amount of Cr absorbed by
the skin after microwave-assisted acid digestion of the tissue. Cr(VI) was found to pass most easily through the skin. Nevertheless,
Cr(VI) was also shown to be absorbed more efficiently by the skin than Cr(III), an observation attributed to a more pronounced
rejection of the positively charged Cr(III) ions by the skin barrier. These results were in good agreement with in vitro permeation
studies previously reported in the literature in which other analytical techniques were used. Differences observed in the
permeation of Cr following the application of aqueous Cr donor solutions and Cr-containing simulated sweat donor solutions
are also described.
相似文献
998.
Suenami K Lim LW Takeuchi T Sasajima Y Sato K Takekoshi Y Kanno S 《Analytical and bioanalytical chemistry》2006,384(7-8):1501-1505
A rapid, selective and sensitive analytical method for the simultaneous determination of 16 nonsteroidal anti-inflammatory drugs (NSAIDs) in human plasma was carried out using Oasis HLB solid-phase extraction (SPE), followed by reversed-phase high-performance liquid chromatography and quadrupole mass spectrometry with electrospray ionization operated in the negative ion mode. The recoveries of NSAIDs from human plasma by SPE were greater than 76.7%. The use of a short column packed with small particles enabled rapid and simultaneous determination within 7 min. The detection limits for the NSAIDs were 0.01–0.9 μg/ml using the selected ion monitoring mode. 相似文献
999.
本文以京津冀雾霾治理为例,综合考虑了PM2.5在地区间的非对称性跨界传输影响、PM2.5治理对民众、企业、政府带来的协同效应。从中央与地方政府视角对比分析了减排指标约束下利益各方的PM2.5治理策略偏好。研究表明:由于跨界传输因子的影响,合作与非合作时污染物的去除量不一定相等。当各地合作与非合作污染物去除量相等时,合作与非合作成本无差异;否则,合作成本优于非合作,而合作成本的降低源于总体减排量减少。如果跨界传输因子增大或减小,合作与非合作治理的成本差距相应地会增加或减小,各地方政府合作治理意愿会逐渐增大或减小;而中央政府可能更希望地方政府在完成减排指标时能尽可能多减排,因此倾向于地方政府采取非合作治理。减排指标设置时应考虑合作与非合作时收益差异,以及各地经济发展水平等因素的影响。 相似文献
1000.
移动互联网业务创新分析 总被引:2,自引:0,他引:2
介绍了移动互联网业务的发展趋势、影响因素和创新实现机制。认为移动互联网业务创新的两条技术路线,一是打造一个开源开放的终端平台架构,解决目前终端平台的限制因素;二是在现有终端平台四分五裂的情况下,依托移动互联网业务发展的总体趋势,构建一个统一的移动终端Web应用环境。 相似文献