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61.
Anisha Gokarna Yong Hwan Kim Yong-Hoon Cho Min Su Lee In Cheol Kang Hyun Kyu Park Min Gon Kim Bong Hyun Chung 《Optical Review》2006,13(4):288-291
We demonstrate the fluorescence mapping of protein microarrays by the technique of scanning near-field optical microscopy
(SNOM) and confocal microscopy. Micron sized spots (300 μm) of human Immunoglobulin G (hIgG) protein with and without a Cy3
dye labeling have been fabricated on glass substrates by an immobilization method which makes use of calixcrown derivatives
termed Prolinker. We have also tried to probe into the well-known “doughnut effect” observed in fluorescence images of proteins
using the SNOM technique. The topographic and fluorescence SNOM images revealed that the number of proteins at the boundary
of the spot were more than at the center in the case of the microarray spot which showed brighter luminescence at the edge
than at the center in the confocal image. 相似文献
62.
茄子组织生物微电极在儿茶酚测定中表现出了较高的生物催化活性,而对抗坏血酸测定则为稳态响应,这表明该电极能有效地消除抗坏血酸的干扰。该电极的灵敏度高,重现性好,对多巴胺测定的线性范围为5.8×10~(-6)~6.5×10~(-4)mol/L,检出下限为:2.9×10~(-6)mol/L。 相似文献
63.
Nadeem Saeed Basant K Puri Angela Oatridge Joseph V Hajnal Ian R Young 《Magnetic resonance imaging》1998,16(10):1237-1247
Two semi-automated methods for quantification of ventricular volume change from baseline and follow-up magnetic resonance imaging scans have been developed. Technique 1 employs direct segmentation of the ventricles from both the scans using thresholding and contour extraction. Technique 2 operates on difference images produced by voxel based intensity subtraction of the baseline from the registered follow-up images. Here, all voxels with intensities above a noise threshold and in a restricted area are monitored to compute volumetric changes. In phantom measurements the first technique was accurate to 0.0046%, the second to 0.167% of the phantom volume. Results from normal volunteers was that the average ventricular volume changed by 1.52% and 1.54% for images acquired within 9 months using techniques 1 and 2, respectively. With schizophrenic patients mean change of 10.78% and 9.43% were found employing the first and second procedures, respectively. All measurements agreed with a radiologist’s visual grading of the changes. Robust, objective, fast, easy-to-use, and fairly accurate procedures have been developed and validated to quantify volumetric changes. 相似文献
64.
C. N. Carducci S. E. Lucangioli V. G. Rodríguez G. C. Fernndez Otero 《Journal of chromatography. A》1996,730(1-2):313-319
Sample preparation procedures using octadecyl (C18) extraction disks were developed to obtain accurate and reproducible results for determinations of clenbuterol (20 μg per dose) and levothyroxine (100 μg per dose) in dissolution media of solid oral dosage forms. Preconcentration of samples allowed final concentrations of 1.1 μg/ml of clenbuterol and 4.0 μg/ml of levothyroxine to be reached prior to CE analysis. The results obtained by CE were in good agreement with those of HPLC. The precision of the migration time, peak area, peak height and accuracy were determined in both intea-day (n = 6) and inter-day (n =18) assays. Linearity was demonstrated over the ranges 0.5–80.0 μg/ml of clenbuterol and 1.0–30.0 μg/ml of levothyroxine. The mean recoveries were higher than 94.0%, ranging from 50 to 125% levels with respect to dose potencies. The proposed methodology may be generally applied to determine drugs at ng/ml concentrations. 相似文献
65.
从芒果皮中提取果胶的工艺研究 总被引:5,自引:0,他引:5
果胶是一种大分子多糖类物质 ,具有良好的胶凝作用 ,用途广泛 ,在国内外市场上的销量很好。 1 990年世界上果胶总产量约 2 5 0 0 0吨 ,而我国 1 990年仅在食品工业上消耗的果胶就达 1 0 0 0吨 ,但国内市场上销售的果胶大部分为进口货[1] 。果胶在我国的生产仍处于开发阶段 ,所以发掘新的提取资源、提高果胶质量、降低果胶生产成本的意义十分重大。目前 ,已有以柑桔皮、向日葵盘、苹果皮、香蕉皮、马铃薯渣为原料提取果胶的研究报道 ,如何从芒果皮中提取果胶却未见报道。芒果在制造罐头和饮料中副产大量下脚料———芒果皮 ,未能得到充分利用… 相似文献
66.
67.
本文研究了硫酸根阴离子对1-苯基-3-甲基-4-苯甲酰基吡唑酮-5(HPMBP,HL)及三辛胺(TOA)协同萃取镨(Ⅲ)及钕(Ⅲ)的影响。发现在SO_4~(2-)体系中协萃机理为:(LnL_3)_o+(HTOAL)_o(HTOA~+LuL_4~-)_o及(HLnL_4)_o+(TOA)_o(HTOA~+LnL_4~-)_o式中Ln~(3+)=Pr~(3+),下标“o”指示有机相中物种,无下标指示水相中物种。固体萃合物的红外光谱及元素分析数据确证了上述机理。 相似文献
68.
69.
Based on the investigation of a non-ionic surfactant-salt-H2O liquid-liquid extraction system, general rules concerning salt selection are concluded and the mechanism of phase separation is explained. The extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydrochloride (PCN) in such a system is studied. Research shows that the extraction efficiency of CPZ can amount to 96% by twice extraction, which means that quantitative extraction is realized, while that of PCN is 77%. This system produces distribution coefficients (KD) of 12.3 and 2.6, respectively, for CPZ and PCN. Extraction mechanism is deduced according to ultraviolet absorbance; and molecular fluorescence spectra change of the drugs in the system studied. 相似文献
70.
蛋白质—四氯苯醌荷移反应的分光光度研究 总被引:5,自引:0,他引:5
本文用分光光度法研究了蛋白质—四氯苯醌荷移反应。通过对影响反应各因素的研究,确立了以四氯苯醌形成荷移络合物的方法测定蛋白质的最佳条件,测定了最大结合数及反应平衡常数。 相似文献