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Hadi N Yehia Rockford K Draper Carole Mikoryak Erin Kate Walker Pooja Bajaj Inga H Musselman Meredith C Daigrepont Gregg R Dieckmann Paul Pantano 《Journal of nanobiotechnology》2007,5(1):8-17
This work concerns exposing cultured human epithelial-like HeLa cells to single-walled carbon nanotubes (SWNTs) dispersed
in cell culture media supplemented with serum. First, the as-received CoMoCAT SWNT-containing powder was characterized using
scanning electron microscopy and thermal gravimetric analyses. Characterizations of the purified dispersions, termed DM-SWNTs,
involved atomic force microscopy, inductively coupled plasma – mass spectrometry, and absorption and Raman spectroscopies.
Confocal microRaman spectroscopy was used to demonstrate that DM-SWNTs were taken up by HeLa cells in a time- and temperature-dependent
fashion. Transmission electron microscopy revealed SWNT-like material in intracellular vacuoles. The morphologies and growth
rates of HeLa cells exposed to DM-SWNTs were statistically similar to control cells over the course of 4 d. Finally, flow
cytometry was used to show that the fluorescence from MitoSOX™ Red, a selective indicator of superoxide in mitochondria, was
statistically similar in both control cells and cells incubated in DM-SWNTs. The combined results indicate that under our
sample preparation protocols and assay conditions, CoMoCAT DM-SWNT dispersions are not inherently cytotoxic to HeLa cells.
We conclude with recommendations for improving the accuracy and comparability of carbon nanotube (CNT) cytotoxicity reports. 相似文献
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Robert J. Whittaker Richard Booth Clare Bailey Shailesh Naire Zimei Rong Linda J. Cummings Lina Mawasse Marianne J. Ellis Nicola J. Kuiper 《Journal of theoretical biology》2009,256(4):533-79
We develop a simple mathematical model for forced flow of culture medium through a porous scaffold in a tissue-engineering bioreactor. Porous-walled hollow fibres penetrate the scaffold and act as additional sources of culture medium. The model, based on Darcy's law, is used to examine the nutrient and shear-stress distributions throughout the scaffold. We consider several configurations of fibres and inlet and outlet pipes. Compared with a numerical solution of the full Navier-Stokes equations within the complex scaffold geometry, the modelling approach is cheap, and does not require knowledge of the detailed microstructure of the particular scaffold being used. The potential of this approach is demonstrated through quantification of the effect the additional flow from the fibres has on the nutrient and shear-stress distribution. 相似文献
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Bhupendra Mathpal Prakash Chandra Srivastava Deepti Shankhdhar Shailesh Chandra Shankhdhar 《Physiology and Molecular Biology of Plants》2015,21(4):567-572
Zinc (Zn) is an important micronutrient for the physiology of plants. It is poorly available to the plants in soil solution. A pot experiment was conducted to evaluate effectiveness of various Zn application methods on key enzyme activities and protein content of two contrasting rice genotypes viz., PD16 (Zn efficient) and NDR359 (Zn inefficient). The treatments were, control (0 mg Zn kg−1 soil), soil application (5 mg Zn kg−1 soil), foliar application (0.5 % ZnSO4 + 0.25 % lime at 30, 60 and 90 days after transplanting), soil (5 mg Zn kg−1 soil) + foliar application of 0.5 % ZnSO4 + 0.25 % lime at 30, 60 and 90 days after transplanting. Among all the methods tested soil+foliar application of Zn fertilizers was found most effective in increasing superoxide dismutase (SOD) and carbonic anhydrase (CA) activities as well as chlorophyll and protein content in both the rice varieties. NDR359, showed higher enzyme activities and more chlorophyll content in leaves than PD16, when Zn was applied either through foliar spray alone or in soil along with foliar application. Regarding the protein content in grains, PD16 showed higher protein content than NDR359, thus showed better translocation of Zn from leaves to grains. 相似文献