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101.
Roy M Niu CJ Chen Y McVeigh PZ Shuhendler AJ Leung MK Mariampillai A DaCosta RS Wilson BC 《Small (Weinheim an der Bergstrasse, Germany)》2012,8(11):1780-1792
Quantum dot (QD) contrast-enhanced molecular imaging has potential for early cancer detection and image guided treatment, but there is a lack of quantitative image contrast data to determine optimum QD administered doses, affecting the feasibility, risk and cost of such procedures, especially in vivo. Vascular fluorescence contrast-enhanced imaging is performed on nude mice bearing dorsal skinfold window chambers, injected with 4 different QD solutions emitting in the visible and near infrared. Linear relationships are observed among the vascular contrast, injected contrast agent volume, and QD concentration in blood. Due primarily to differential light absorption by blood, the vasculature is optimally visualized when exciting in the 435-480 nm region in 81% of the cases (89 out of 110 regions of interest in 22 window chambers). The threshold dose, defined here as the quantity of injected nanoparticles required to yield a vascular target-to-autofluorescence ratio of 2, varies from 10.6 to 0.15 pmol g(-1) depending on the QD emission wavelength. The wavelength optimization maximum and broadband gain, defined as the ratio of threshold doses estimated for optimal and suboptimal (worst wavelength or broadband) spectral illumination, has average values of 4.5 and 1.9, respectively. This study demonstrates, for the first time, optimized QD imaging in vivo. It also proposes and validates a theoretical framework for QD dose estimation and quantifies the effects of blood absorption, QD emission wavelength, and vessel diameter relative to the threshold dose. 相似文献
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Marijan Dravinski Yuqing Niu 《International journal for numerical methods in engineering》2002,53(2):445-472
Time‐harmonic Green's functions for a triclinic anisotropic full‐space are evaluated through the use of a symbolic computation system.This procedure allows evaluation of the Green's functions for the most general anisotropic materials. The proposed computational algorithms are programmed in a MATLAB environment by incorporating symbolic calculations performed using Maple Computer Algebra System. Extensive testing of the numerical results has been performed for both displacement and stress fields. The tests demonstrate the accuracy of the proposed algorithm in evaluating the Green's functions. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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共用３８０个１０碱基随机引物,对抗条锈病基因ＹｒＬｅｅ的近等基因系进行了ＲＡＰＤ分析,其中有两个引物在抗病的近等基因系ＹｒＬｅｅ／６＊Ｔａｉｃｈｕｎｇ２９Ｆ３和基因供体亲本“Ｌｅｅ”中扩增出了特异的ＤＮＡ片段,而在轮回亲本“Ｔａｉｃｈｕｎｇ２９”中没有扩增出同样的ＤＮＡ片段。引物ＯＰＲ－７扩增出的ＤＮＡ片段长度约为４６５ｂｐ,引物ＯＰＲ－９扩增出的ＤＮＡ片段长度约为６６７ｂｐ。用基因供体亲本“Ｌｅｅ”与感病品种“铭贤１６９”杂交的Ｆ２代分离群体（１８９株植株）进行的遗传连锁性分析表明,引物ＯＰＲ－７扩增出的特异ＤＮＡ片段与ＹｒＬｅｅ基因紧密连锁。 相似文献
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Niu JJ Schrlau MG Friedman G Gogotsi Y 《Small (Weinheim an der Bergstrasse, Germany)》2011,7(4):540-545
Gold nanoparticle-decorated carbon nanotubes (CNTs) are used to study intracellular environments in situ using surface-enhanced Raman spectroscopy (SERS). CNTs are decorated with gold nanoparticles and assembled onto the tips of pulled glass capillaries to form a SERS-enabled endoscope. The sub-micrometer size and high mechanical strength of the endoscope make it possible to penetrate the cell membrane for intracellular probing and remain positioned inside during lengthy SERS measurements without causing damage to the cell. Using the SERS-enabled endoscope, DNA and other biomolecules are detected in situ within the nucleus of a single human cervical carcinoma cell in a minimally invasive manner. The SERS-enabled endoscopes exhibit high selectivity and sensitivity for detecting trace amounts of analytes (≈1 pM) in biofluid environments, highlighting their capabilities as label-free, biological sensors for real-time in situ cellular diagnostics, biological detection, and pharmaceutical research. 相似文献
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