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991.
992.
Effects of plasma treatment on biocompatibility of poly[(L‐lactide)‐co‐(ϵ‐caprolactone)] and poly[(L‐lactide)‐co‐glycolide] electrospun nanofibrous membranes 下载免费PDF全文
Pimwalan Techaikool Donraporn Daranarong Jutamas Kongsuk Dheerawan Boonyawan Nursyuhada Haron William S Harley Kyle A Thomson L John R Foster Winita Punyodom 《Polymer International》2017,66(11):1640-1650
Poly[(l ‐lactide)‐co ‐(? ‐caprolactone)] (PLCL) and poly[(l ‐lactide)‐co ‐glycolide] (PLGA) copolymers are widely used in neural guide tissue regeneration. In this research, the surface modification of their hydrophilicity was achieved using plasma treatment. Attachment and proliferation of olfactory ensheathing cells on treated electrospun membranes increased by 26 and 32%, respectively, compared to the untreated PLCL and PLGA counterparts. Cells cultivated on both the PLCL and PLGA membranes showed high viability (>95%) and healthy morphologies with no evidence of cytotoxic effects. Cells grown on treated electrospun fibres displayed significant increases in mitochondrial activity and reductions in membrane leakage when compared to untreated samples. The results suggested that plasma treatment of the surface of the polymers enhanced both cell viability and growth without incurring any cytotoxic effects. © 2017 Society of Chemical Industry 相似文献
993.
《Measurement》2014
A novel 4-UPS-UPU spatial 5-Degree of freedom parallel coordinate measuring machine (PCMM) is presented. The workspace of the measuring machine is analyzed by using polar coordinate searching method. The force balance equation and statics transfer matrix of the measuring machine are established. The statics analysis of the 4-UPS-UPU PCMM is realized by taking the PCMM with load and no-load as example, and the numerical verification and virtual simulation verification of the results of driving force are carried out. The research can provide a theoretical basis for the optimal design and manufacturing of 4-UPS-UPU PCMM. 相似文献
994.
Mustafa Mortas Fehmi Yazici Muhammet Dervisoğlu 《International Journal of Food Properties》2017,20(8):1866-1875
The effect of brewing process on 5-hydroxymethylfurfural, 2-furylmethylketone, and 2-furoic acid levels of traditionally prepared and instant Turkish coffee samples containing different amounts of table sugar (0, 2, 4, or 8 g in 20 mL of coffee) were analyzed by high pressure liquid chromatography with diode array detector. The highest change at the levels of furfurals was observed in sample of traditional and instant Turkish coffee named T4 and S4 both of containing 8 g of sugar, respectively. The results showed that 5-hydroxymethylfurfural, 2-furylmethylketone, and 2-furoic acid concentrations in both traditionally prepared and instant Turkish coffee samples increased with increasing sugar concentration. The brewing method and sugar concentration had a significant effect on furfural contents of Turkish coffee (p < 0.05). Daily intakes of furfurals for Turkish population were calculated as 8.14–13.54 and 9.36–10.25 µg kg?1 body weight for traditionally prepared and instant Turkish coffee samples, respectively, and daily intakes of furfurals were lower than the acceptable daily intake value of 0.5 mg kg?1 body weight. 相似文献
995.
《Applied ergonomics》2014,45(2):234-238
Lower-back injury from snow shovelling may be related to excessive joint loading. Bent-shaft snow shovels are commonly available for purchase; however, their influence on lower back-joint loading is currently not known. Therefore, the purpose of this study was to compare L5/S1 extension angular impulses between a bent-shaft and a standard straight-shaft snow shovel. Eight healthy subjects participated in this study. Each completed a simulated snow-lifting task in a biomechanics laboratory with each shovel design. A standard motion analysis procedure was used to determine L5/S1 angular impulses during each trial, as well as peak L5/S1 extension moments and peak upper body flexion angle. Paired-samples t-tests (α = 0.05) were used to compare variables between shovel designs. Correlation was used to determine the relationship between peak flexion and peak moments. Results of this study show that the bent-shaft snow shovel reduced L5/S1 extension angular impulses by 16.5% (p = 0.022), decreased peak moments by 11.8% (p = 0.044), and peak flexion by 13.0% (p = 0.002) compared to the straight-shaft shovel. Peak L5/S1 extension moment magnitude was correlated with peak upper body flexion angle (r = 0.70). Based on these results, it is concluded that the bent-shaft snow shovel can likely reduce lower-back joint loading during snow shovelling, and thus may have a role in snow shovelling injury prevention. 相似文献
996.
简要介绍了H13模具钢的性能特点及应用概况,重点讨论了它的锻造要点和热处理工艺特点,分析了H13热锻模寿命不长、频繁失效的原因,并提出了纠正和预防措施。 相似文献
997.
LIU 《中国稀土学报(英文版)》2010,28(6):965-968
A novel tungstosilicic polyoxometalate containing 5-fluorouracil and Nd,K26(C4H4FN2O2)8Nd(SiW11O39)4·SH2O(FNSW)was synthesized and its structure was characterized by using elemental analysis,FT-IR spectra,X-ray powder diffraction,UV-vis spectra and TG.The results indicated that the compound FNSW had Keggin structure of heteropolyanion and ring structure of 5-fluorouracil,and it had a good thermal stability.With 5-fluorouracil for the positive control group,the cytotoxicity tests in human renal embryonic cell HEK293 and the antitumor activity tests in hepatocellular carcinoma cell HepG-2 were carried out by the methyl thiazolyl tetrazolium method.The toxicity of the compound FNSW was lower than that of 5-fluorouracil,and compared with 5-fluorouracil the compound FNSW could inhibit HepG-2cell in vitro with significant difference.The rare earth clement Nd increased the biological activity of polyoxometalate significantly. 相似文献
998.
999.
Under microwave irradiation, concentrated fructose (33-92 wt%) in ionic liquids afforded 5-hydroxymethylfurfural in ca. 97-57% yields without addition of catalysts, within 3 min. In-situ13C NMR and 1H NMR spectra suggest that the transformation of fructose in ionic liquid is a highly selective reaction that proceeds predominantly via the cyclic fructofuransyl intermediate. This method is expected to be valuable in facilitating cost-effective conversion of carbohydrates into biofuels and platform chemicals. 相似文献
1000.
Ti5Al2.5Sn ELI钛合金是航空航天等领域重要的结构材料。本工作采用3种铸型同炉浇注的方法研究了铸造工艺对该合金铸态组织和室温拉伸性能的影响。结果表明,该合金石墨型铸造试样表面粗糙,陶瓷型和金属型的则较光滑;石墨型试样宏观组织为大量等轴晶和少量柱状晶,金属型的为少量等轴晶和大量柱状晶,陶瓷型的为粗大柱状晶和等轴晶;不同工艺下显微组织均由不规则边界α集束组成,其内部为片状α相,石墨型的α片宽度最小,金属型的次之,陶瓷型的最大;该合金铸态抗拉强度715~731 MPa、伸长率8%~15%,石墨型的伸长率最高,金属型的次之,陶瓷型的最低,铸造工艺对该合金塑性影响强烈,但对强度的影响较小;铸型表面形貌、导热系数、α集束大小及α片厚度的不同是上述现象产生的主要原因。 相似文献