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1.
不同浓度乙醇对蜂胶中的铅提取效果的研究 总被引:6,自引:0,他引:6
采用不同浓度的乙醇90%、85%、80%、75%、70%、65%、50%,对蜂胶的有效成分进行提取,测定其提取液和残渣中的铅含量,并计算其提取率。结果表明:随乙醇浓度的上升,提取率及提取液中的铅含量增高。其中乙醇浓度为75%、70%和65%的蜂胶提取液中的铅含量均小于1ppm,符合我国食品卫生法关于食品中的铅含量不得超过1ppm的规定。 相似文献
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Chun-Zhi REN Wen-Yue HU Jun-Cheng LI Ying-Hong XIE Ni-Na JIA Jun SHI Ying-Yi WEI Ting-Jun HU 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2020,82(12):1781
Pseudorabies virus (PRV) infection leads to severe inflammatory responses and tissue damage, and many natural herbs exhibit protective effects against viral infection by modulating the inflammatory response. An ethyl acetate fraction of flavonoids from Polygonum hydropiper L. (FEA) was prepared through ethanol extraction and ethyl acetate fractional extraction. An inflammatory model was established in RAW264.7 cells with PRV infection to evaluate the anti-inflammatory activity of FEA by measuring cell viability, nitric oxide (NO) production, reactive oxygen species (ROS) release, and mRNA expression of inflammatory factors, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Its functional mechanism was investigated by analyzing the phosphorylation and nuclear translocation of key proteins in the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Our findings indicate that PRV induced inflammatory responses in RAW264.7 cells, and the responses were similar to that in lipopolysaccharide (LPS)-stimulated cells. FEA significantly suppressed NO synthesis and down-regulated both expression and secretion of COX-2, iNOS, and inflammatory cytokines (P<0.05 or P<0.01). FEA also reduced NF-κB p65 translocation into the nucleus and decreased MAPK phosphorylation, indicating that the NF-κB/MAPK signaling pathway may be closely related to the inflammatory response during viral infection. The findings suggested the potential pharmaceutical application of FEA as a natural product that can treat viral infections due to its ability to mitigate inflammatory responses. 相似文献
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以能源植物斑茅纤维为原料,探讨纤维素糖化液生产燃料酒精的发酵工艺研究,分析了时间、温度、pH、氮源种类、酵母膏用量与酵母用量等因素对斑茅纤维素酒精发酵的影响。结果表明:反应时间72~96h,温度35℃,pH4.8~5.2,酵母膏氮源用量0.8%~1.0%,酵母用量10%~15%时斑茅纤维糖化液的酒精发酵效果最好。通过正交试验确定了最佳发酵条件:时间84h、温度35℃、酵母膏用量1.2%、酵母用量20%,发酵验证酒精值达4.6%(V/V),酒精得率32.62%。 相似文献
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为有效快速测定饲料中斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯含量,饲料经甲醇、正己烷和乙酸乙酯混合液萃取后,在氮气保护下浓缩,用甲基叔丁基醚-乙腈溶液复溶,注入超高效液相色谱仪中进行测定。结果表明:斑蝥黄浓度为1.25~10.0μg/mL,β-阿朴-8’-胡萝卜素酸乙酯为2.50~20.0μg/mL线性关系良好;斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯的检测限为0.06 mg/kg,定量限为0.20 mg/kg。斑蝥黄5个添加水平的平均回收率为72.8%~82.8%,相对标准偏差(RSD)为0.41%~1.06%;β-阿朴-8’-胡萝卜素酸乙酯5个添加水平的平均回收率为72.0%~82.8%,RSD为0.46%~1.41%。说明该方法简便、快速、灵敏度高、准确度好,适用于测定饲料中斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯含量。 相似文献
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以水溶性聚合物聚乙烯醇(PVA)和水不溶性聚合物乙酸乙烯-乙烯共聚物(VAE)乳液为原料,采用溶液共混法制备了PVA-VAE共混膜,为农药成膜剂的制备开辟了新途径。红外光谱、透射电镜、激光粒度仪测试结果显示,PVA溶液中的胶束被打开,体系的比表面积急剧增大,两相间的界面消失,说明共混体系分子间具有良好的相容性;透水性与耐水性测定结果表明,PVA-VAE的质量比为80∶ 20、70∶ 30、60∶ 40时其共混膜的性能适用于农药种衣剂的成膜剂;种子发芽试验显示,与单独使用PVA膜相比,引入适当比例VAE后的共混膜用于种子包衣,其耐水性显著提高,渗水率适宜,对种子发芽无明显影响。 相似文献
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A field trials programme was conducted in which the performance of a new emulsifiable concentrate formulation (ECI) of flamprop-M-isopropyl containing the adjuvant, ‘Dobanol’ 25-7, in a ratio of 2:1 (by weight) with the AI, was compared with the current commercial formulation of ‘Commando’, in combination with its recommended adjuvant, ‘Swirl’, for the control of wild oat (Avena fatua L.) in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). A further treatment, in which the ‘Dobanol’ 25-7: AI ratio was increased to 4:1 by the spray tank addition of the former, was also included. The mean results from six trials (five wheat, one barley) showed that the addition of ‘Swirl’ to ‘Commando’ was beneficial, increasing wild oat floret control from a mean value of 80% to 92% at current recommended rates (flamprop-M-isopropyl, 600 g ha?1; ‘Swirl’, 2.5 litre ha?1). However, combinations of flamprop-M-isopropyl and ‘Dobanol’ 25-7 gave superior levels of control even at lower AI application rates. For example, a mean level of 96% control of Avena spp. was obtained at 300 g AI ha?1 with 1200 g ha?1 ‘Dobanol’ 25–7; with even better control at higher rates of application of both components. This improvement in performance was accompanied by a higher risk of crop phytotoxicity than observed with the ‘Commando’/‘Swirl’ mixtures. Symptoms initially were scorch and subsequently growth depression, particularly of tillers. None of the mean values in the six ‘efficacy’ trials reached commercially unacceptable levels, but in a further six ‘crop effects’ trials (three wheat, three barley), in which double rates were applied, the levels of phytotoxicity did become unacceptable and subsequently reduced grain yields. In contrast, two barley ‘crop effects’ trials gave yields higher than the control plots, possibly through the effects of reducing stem length and lodging thereby enabling more efficient harvesting. Nevertheless, there were rates of application of flamprop-M-isopropyl in the range 300–400 g ha?1 with ratios of ‘Dobanol’ 25-7 in the range 2:1 to 4:1 that would achieve high levels of control of Avena spp. without undue risk of crop phytotoxicity and further trials are planned to support this new adjuvant system. 相似文献