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941.
942.
超声波法提取猕猴桃籽油的工艺研究 总被引:1,自引:1,他引:1
对超声波技术提取猕猴桃籽油的工艺进行研究.探讨了不同提取剂,提取的剂用量、提取时间、次数及超声波功率对提取效果的影响。最后用正交法确定最佳工艺条件:在超声波功率250w的条件下,石油醚作为提取剂、物料比1:8、提取2次,每次20min. 相似文献
943.
超声物理改性对SPI功能特性的影响 总被引:2,自引:0,他引:2
采用超声仪对大豆分离蛋白(SPI)溶液进行超声处理,研究了不同超声处理时间,不同功率处理后SPI功能特性的变化。结果表明,超声处理后大豆分离蛋白的溶解性、起泡性、乳化性和凝胶性都有明显的提高。 相似文献
944.
945.
Timothy E.L. Douglas Marta Vandrovcová Nikola Kročilová Julia K. Keppler Jana Zárubová Andre G. Skirtach Lucie Bačáková 《Journal of dairy science》2018,101(1):28-36
Recently, milk-derived proteins have attracted attention for applications in the biomedical field such as tissue regeneration. Whey protein isolate (WPI), especially its main component β-lactoglobulin, can modulate immunity and acts as an antioxidant, antitumor, antiviral, and antibacterial agent. There are very few reports of the application of WPI in tissue engineering, especially in bone tissue engineering. In this study, we tested the influence of different concentrations of WPI on behavior of human osteoblast-like Saos-2 cells, human adipose tissue-derived stem cells (ASC), and human neonatal dermal fibroblasts (FIB). The positive effect on growth was apparent for Saos-2 cells and FIB but not for ASC. However, the expression of markers characteristic for early osteogenic cell differentiation [type-I collagen (COL1) and alkaline phosphatase (ALP)] as well as ALP activity, increased dose-dependently in ASC. Importantly, Saos-2 cells were able to deposit calcium in the presence of WPI, even in a proliferation medium without other supplements that support osteogenic cell differentiation. The results indicate that, depending on the cell type, WPI can act as an enhancer of cell proliferation and osteogenic differentiation. Therefore, enrichment of biomaterials for bone regeneration with WPI seems a promising approach, especially due to the low cost of WPI. 相似文献
946.
本文以食源性致病菌阪崎肠杆菌为对象,研究了医学领域抗细菌感染蓝光的杀菌作用,并首次对其杀菌机制进行了探究。结果表明,当蓝光剂量大于30 J/cm~2时,对阪崎肠杆菌具有显著杀菌作用,照射剂量达240 J/cm~2时,杀菌率超过8 log 10 CFU。亚致死剂量(0~30 J/cm~2)蓝光照射下,单线态氧(~1O_2)探针SOSG开始出现绿色荧光信号,显示细胞内1O2涌现并造成细胞外壁微小孔洞;活性氧物质(ROS)也迅速产生并逐渐增大至5 a.u.;随后脂质氧化标志物丙二醛(MDA)逐渐增加,显示细胞内产生脂质氧化。上述胞内物质变化导致细胞外膜受损,30 J/cm~2蓝光下细胞外膜渗透性增加了48.96%;此外脂肪酰基谱测定揭示,不饱和脂肪酸C18:2,C16:1和C18:1含量减少并逐渐消失,很可能是细胞外膜损伤的重要原因之一。本研究确证了蓝光下细菌胞内~1O_2、ROS及脂质氧化物的动态变化,更重要是的,揭示了细胞外膜损伤是蓝光杀菌的重要方式之一,因为细菌脂质尤其是不饱和脂肪酸是蓝光杀菌重要靶标,本研究将有助于蓝光杀菌机制的深入探究。 相似文献
947.
J.W. Aleri B.C. Hine M.F. Pyman P.D. Mansell W.J. Wales B. Mallard M.A. Stevenson A.D. Fisher 《Journal of dairy science》2019,102(4):3282-3294
The objectives of this study were to assess antibody and cellular immune responses in first-lactation dairy heifers reared under a pasture-based production system and to investigate associations between immune competence and stress responsiveness, health, and productivity. A commercial vaccine was used to induce antibody and cellular immune responses and, based on measured responses, animals were classified as above average, average, and below average for each trait independently and in combination (overall immune competence). Overall immune competence phenotypic rankings were generated by combining standardized residual values for antibody and cellular responses measured in individual heifers. Cortisol responses to handling and yarding were used to assess stress responsiveness, worm egg counts were used to assess internal parasite burden, somatic cell counts to assess udder health and estimates of total daily milk volume, and milk fat and milk protein contents to assess productivity. A total of 393 Holstein-Friesian and Holstein-Friesian × Jersey crossbred heifers from 2 herds practicing seasonal calving in a pasture-fed production system were enrolled in the study. The immune competence phenotypes of individual heifers were assessed before their first mating and their subsequent performance during their first lactation was monitored. Animals with below-average antibody and cellular immune competence had higher serum cortisol concentrations compared with their counterparts following handling, suggesting they had a reduced ability to cope with management-induced stress. Furthermore, a significant negative (favorable) correlation was observed between antibody responses and stress responsiveness. Similarly, correlations between antibody responses and internal parasite burden were significant and negative (favorable). No correlations were observed between overall immune competence and milk yield, milk fat, and milk protein content. 相似文献
948.
作为人体必需的一类脂溶性维生素,维生素D经常用于强化食品和药物,用于营养素补充和骨质疏松等疾病的辅助治疗,但由于对补充剂量的控制不当和维生素D产品的监管不足,维生素D高剂量摄入所引起的中毒案例也随之增多,维生素D的安全性研究受到了越来越多的关注。本文整理和分析了维生素D安全性研究的相关文献和报道,发现高剂量维生素D在细胞水平及对骨骼、肝脏、肾脏等组织和器官均存在一定的损害和毒性作用,能够抑制细胞增殖,对氨基酸代谢、糖代谢、脂质代谢等代谢途径造成影响,甚至诱发高钙血症、高磷血症、动脉粥样硬化、组织钙化等疾病。因此,维生素D的补充剂量应得到合理的控制和管理,对其毒性机制的研究也应得到更多的关注。 相似文献
949.
950.