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991.
Qiu Tong Wu Qingzhi Dai Honglian Wang Xinyu Wang Youfa Li Shipu Li Junli 《Journal of materials science. Materials in medicine》2014,25(8):1915-1923
A comparative study was performed to investigate the ultrastructural and biomolecular properties of osteoblasts induced by three types of single-walled carbon nanotubes (SWNTs). The results on cellular uptake and ultrastructural alteration indicate that SWNTs enter osteoblasts by endocytosis. SWNTs-COOH and SWNTs-OH particles were freely dispersed in the cytoplasm, while pristine SWNTs were localized to the periphery of the cell. Both SWNTs-OH and SWNTs-COOH promoted cell changes in cell activity regarding mRNA expression at doses of 50 and 100 μg/mL in the first 24 h. When treated with 50 μg/mL SWNTs-COOH for 48 h, the expression of type I collagen increased by 6.3-fold (for MG63) or 9.1-fold (for primary osteoblasts) compared with the control group. The present study observed for the first time that SWNTs-COOH initiated the prompt and the maximum upregulation of type I collagen gene expression, and simultaneously induced the expansion of the endoplasmic reticulum for increased protein synthesis, which in turn accelerated the mineralization process. However, impaired cell properties and mitochondrial injury were detected following treatment with SWNTs at 100 μg/mL after 48 h. In conclusion, we believe that SWNTs-COOH is a good candidate for the fabrication of biomedical scaffolds for bone regeneration. 相似文献
992.
螺旋管中间介质气化器可行性研究 总被引:1,自引:0,他引:1
A novel intermediate fluid vaporization (IFV) technology for LNG re-gasification process with spiral-wound heat exchanging tubes is proposed. The new IFV project combines the advantage of running the shell and tube heat exchangers at high pressure with the advantage of compact space of heat exchangers. Thermal analysis on the two processes of forced convection and vaporization type heat transfer in the spiral wound tubes and vapor condensation /re-boiling type of heat transfer via intermediate fluid in shell side shows the feasibility of this promising technology. 相似文献
993.
目的:建立血液中佐匹克隆全自动固相萃取高效液相色谱-三重四级杆串联质谱(LC/MS/MS)检测方法。方法:采用全自动固相萃取进行提取,用Oasis HLB固相萃取柱,使用二氯甲烷洗脱。洗脱物浓缩后用Eclipse Plus C18柱(3.5μm×2.1×100mm)分离,LC/MS/MS分析。结果:采用本文方法检测血液中佐匹克隆的检出限为0.1ng/ml,回收率大于90.0%。结论:本方法具有操作简单、灵敏度高和重现性好等优点,可应用于血液中佐匹克隆的检验鉴定。 相似文献
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996.
Shiru Jia Baoqing Fan Yujie Dai Guoliang Wang Peng Peng Yuanyuan Jia 《Food science and biotechnology》2010,19(2):361-366
ɛ-Poly-l-lysine (ɛ-PLL) produced by Streptomyces albulus CGMCC 1986 was fractionated using ultra-filtration technique with 2 and 5 kDa cut-offs of membrane. The number-average molecular
weight of each fraction was determined by 1H nuclear magnetic resonance (NMR) method. The number-average molecular weights of the cutoffs of 5 and 2 kDa and the filtrate
are 4,230.95, 3,687.80, and 1,900.82 Da, respectively. 1H NMR indicates the chemical shifts of α-H, β-H, γ-H, δ-H, and ɛ-H are very similar to all the fractions. Fourier transform-infrared
(FTIR) spectra showed that the ɛ-PLL solid samples obtained by freeze-drying at pH 5 with molecular weights higher than 2
kDa take on a β-turn conformation, however, the fraction with molecular weight smaller than 2 kDa adopts random coil structure.
The antibacterial test proved that the fraction between 2 and 5 kDa of membranes behaves the highest antibacterial activity
than other fractions for the test strains of Staphylococcus aureus, Micrococcus luteus, Bacillus subtilis, Escherichia coli, and Shigella. 相似文献
997.
Shelly Hogan Hyun Chung Lei Zhang Jianrong Li Yongwoo Lee Yumin Dai Kequan Zhou 《Food chemistry》2010,118(2):208-214
An anthocyanin-rich extract, generated from açai (AEA), was investigated for its antioxidant properties and antiproliferative activity against C-6 rat brain glioma cells and MDA-468 human breast cancer cells. AEA has an ORAC value of 2589 μmoles trolox equivalents (TE)/g dried powder and a DPPH radical-scavenging activity of 1208 μmoles TE/g, suggesting that AEA is an exceptional source of natural antioxidants. In addition, AEA remarkably suppresses proliferation of C-6 rat brain glioma cells, but has no effect on the growth of MDA-468 human breast cancer cells. Further experiments demonstrated that the AEA treatment dose-dependently inhibited the growth of C-6 rat glioma cells with an IC50 of 121 μg/ml. The DNA ladder fragmentation results indicated that AEA induced apoptosis of C-6 rat brain glioma cells. To compare açai with other anthocyanin-rich extracts, a number of berry extracts, including blueberry, strawberry, raspberry, blackberry and wolfberry, were assessed for potential antiproliferative activity against C-6 rat brain glioma cells. However, none of them showed suppressing effect. The results suggest that the active antiproliferative constituents in AEA are unlikely to be anthocyanins normally found in common berries. 相似文献
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寻求心脏病的早期诊断方法是当务之急,高频心电除了具有较宽的通频带和较小信号幅度外,它比常规心电图具有更多的有关心脏活动状态的信息,可以观察到更多有关心脏主要部位病变的细节,能揭示出QRS综合波上某些部位的波形特征,所谓切迹(motch)和转折(slur)。本文重点研究高频心电的分析和识别方法及其技术实现。 相似文献